innovation water

KAUST Industry Collaboration Program (KICP)

Promoting Wastewater Reclamation and Reuse in the Kingdom of Saudi Arabia: Technology Trends, Innovation Needs, and Business Opportunities

The KICP Annual Strategic Study

2010-2011

Prepared by,

Managed By,

KAUST Industry Collaboration Program (KICP)

Confidentiality Statement All content included in this report, such as text, logos, small icons and images, is the property of King Abdullah University for Science and Technology (KAUST). No part of this report may be reproduced in any form without the prior written permission of KAUST.

DISCLAIMER The study in this report was conducted by a third-party consultant and, as such, does not express the opinion of KAUST. KAUST does not take any responsibility for the contents of this report, does not make any representation as to its accuracy or completeness, and expressly disclaims any liability whatsoever for any loss arising from, or incurred in reliance upon, any part of this report.

STRATEGIC STUDY

Acknowledgements

This Strategic Study was prepared with published and unpublished information and assistance from individuals within universities, agencies, and private companies. At King Abdullah University of Science and Technology (KAUST), information and technical input were received from the following groups and individuals:

KAUST Center for Water Desalination and ReuseDr. Gary Amy, Professor and DirectorDr. Jorg E. Drewes, Visiting Professor and Associate DirectorDr. Thomas Missimer, Visiting Professor

KAUST Red Sea Research CenterDr. James Luyten, Professor and Director

KAUST Coastal and Marine Resources Core LaboratoryDr. Abdulaziz Al-Suwailem, Manager

Information was also received from many ministries and outside organizations, including:

• National Water Company

• Ministry of Water and Electricity (MOWE)

• Saudi Geological Survey

• Presidency of Meteorology and Environment

• The Regional Organization for the Conservation of the Environment of the Red Sea and Gulf of Aden

In particular, the Draft MOWE Regional Planning Reports provided by representatives of that agency were an extremely valuable source of base information that helped in framing the Strategic Study.

Finally, we would like to acknowledge the support from the KAUST Industrial Collaboration Program (KICP). KICP members provided funding for this Strategic Study, part of an annual series at KAUST, and many organizations provided technical input regarding technologies as well as technical review of draft portions of the study. In addition, KICP staff provided continual support and input as the study proceeded that significantly improved the overall Strategic Study.

STRATEGIC STUDY

Preface

This Strategic Study is intended for use among a diverse group of readers from the Kingdom of Saudi Arabia and abroad. Accordingly, Systeme Internationale (SI) units are used in most parts of this report. However, for projects where results have been published previously using non-SI units, no conversions to SI units were made.

The Strategic Study includes nine chapters that have been put together by a combination of authors within CH2M HILL, with subcontractors, and through an independent contract with the King Abdullah University of Science and Technology (KAUST). The Executive Summary and Summary Report were developed by CH2M HILL based on the chapter content. The following is a list of the companies primarily responsible for the chapters:

Chapter Number and Title Responsible Firm

1 – Current Status of Water Reuse in Saudi Arabia CH2M HILL

2 – Technology Overview CH2M HILL

3 – Public Education and Awareness to Promote Recycled Water Use Moya Bushnak

4 – Business Opportunities CH2M HILL

5 – Aquifer Recharge and Recovery Schlumberger Water Services

6 – Water Quality and Wastewater Disposal Impacts CH2M HILL

7 – Regulatory Considerations CH2M HILL

8 – Septage Handling and Treatment CH2M HILL

9 – Patent Landscape RTI International (under separate contract to KAUST)

As this document was prepared, review comments were received from KAUST staff, from members of the KAUST Industrial Collaboration Program, and from outside reviewers. In this type of comprehensive review, it is often not possible to access all available information for any specific topic. The authors have tried to provide appropriate and comprehensive references for available sources of information.

EXECUTIVE SUMMARY

Study Background and Context Water reclamation and reuse has become an important worldwide total water management topic as the limitations of freshwater resources have come into sharp focus. In the Kingdom of Saudi Arabia (KSA), potable water is produced from either non- or very slowly renewable water resources such as groundwater, or capital- and energy-intensive seawater desalination. The KSA also lacks sufficient water and wastewater treatment capacity to meet future demands. In response, the KSA is developing reclaimed water sources to help meet future demands.

Key public and private KSA organizations are working in partnership to expand the application of reclaimed water. Among these are the National Water Company (NWC), the Ministry of Water and Electricity (MOWE), and the King Abdullah University for Science and Technology (KAUST) Industry Collaboration Program (KICP). These organizations have been responsible for actions to promote reuse in the KSA, highlighted in Figure 1, and will oversee and promote the implementation process to meet the aggressive new goals.

FIGURE 1 Timeline of KSA Actions to Promote Reuse

Study Goals and Organization KAUST’s Annual Strategic Studies are part of its overall collaborative research program, This year’s Strategic Study, Promoting Wastewater Reclamation & Reuse in the Kingdom of Saudi Arabia: Technology Trends, Innovation Needs, and Business Opportunities, assesses opportunities for water reuse in the KSA and reports findings related to: identifying specific uses for reclaimed water now and in the future; identifying gaps in technology, education, and business opportunities related to wastewater treatment and reuse; and increasing the integration of water reclamation in KSA into overall water resources management.

The Strategic Study report is organized into nine chapters. This Executive Summary provides at-a-glance highlights of each chapter’s key findings and recommendations (denoted by italics) and concludes with a recommended path forward in support of reuse.

Chapter 1: Overview of Water Reuse in Saudi Arabia • Water demands are expected to double over the next two decades with rapid population

growth and increased urbanization—a shortfall already exists in the six major cities; today, over 80 percent of the KSA water supply is from groundwater aquifers, but this source is expected to last only another 15 to 25 years.

Executive Summary

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Promoting Wastewater Reclamation & Reuse in the Kingdom of Saudi Arabia: Technology Trends, Innovation Needs, and Business Opportunities

Executive Summary

REUSE OPPORTUNITIES IN THE KINGDOM OF SAUDI ARABIA

VI EXECUTIVE SUMMARY

• A current barrier to reuse is the lack of sufficient infrastructure—collection network and/or wastewater treatment plant (WWTP) capacity—to treat all wastewater.

• In some places with WWTPs, agricultural and industrial reuse is already occurring. Other opportunities for reuse include landscaping, recreation, and aquifer recharge.

• With demand outpacing current water and wastewater treatment capacities, the KSA has aggressive national goals for reuse: for example, by 2025, cities over 5,000 people should be reclaiming nearly 100 percent of their water.

• Significant improvements in water usage and wastewater treatment data quality and quantity are needed for a comprehensive and integrated water resources management program.

• Although developing reuse programs for cities over 5,000 people is a monumental undertaking, thought should be given to how wastewater can best be managed in rural areas and smaller cities as well. New strategies and business opportunities for reuse in these areas would be valuable.

Chapter 2: Technology Overview • Many readily available current technologies are highly effective in reliably producing reuse

quality treated sewage effluent (RQTSE), which can be used for many purposes.

• Other emerging and developmental technologies will soon be more widely available to further increase the benefits of reuse by using less energy, or satisfying energy needs from renewable sources or waste heat, creating less reject stream and unwanted byproducts.

• It also is possible to recover and beneficially use other outputs of the wastewater treatment process, such as biogas, biosolids, and nutrients.

• Continued collaboration among the research, industrial, and governmental communities is needed to support the process of bringing to market new energy-efficient and cost-effective technologies.

Chapter 3: Public Education and Awareness to Promote Recycled Water Use • Reaching the KSA’s goals for reuse will depend on meeting the challenge of securing public

acceptance and endorsement for the expanded water reuse program.

• A successful public education and awareness program will provide credible information about the types of treatment processes available and the quality of recycled water.

• Key program components include using mass media, promoting publicly accessible research, launching a National Steering Committee with respected community leaders, and providing onsite learning and demonstration opportunities.

• The program should engage leading religious scholars, believed to be essential in gaining support and acceptance for reuse, and secure their help in branding reclaimed water as “Tahir,” meaning water without any smell, color, or taste that can even be used for any religious purpose.

Chapter 4: Business Opportunities • Reuse provides business opportunities and supports economic development when recycled

water is less expensive than first use water, especially desalinated water.

• The Draft MOWE Regional Planning Reports’ project proposals and other reviewed case studies demonstrate that reuse can be profitable, often showing that investments in recovering and treating wastewater for reuse can be recouped in less than 5 years.


EXECUTIVE SUMMARY VII

• Five reuse portfolio scenarios developed for this Strategic Study show that reuse across multiple sectors, including agriculture, industry, landscaping, recreation, and recharge, can be financially viable, provided a reasonable water rate structure is established.

• Reuse water providers and prospective customers should collaborate to identify opportunities for cost-effective treatment and delivery systems. Rate structures must be financially rational and optimized for specific user bases, including higher rates for high quality, reuse rates competitive with first use water rates, and lower rates where needed to encourage demand for reclaimed water.

Chapter 5: Managed Aquifer Recharge • There are several different uses for RQTSE in managed aquifer recharge (MAR) strategies

in the KSA involving storage, treatment, and recovery.

• RQTSE can be used to strategically store currently available excess water for future use; serve as a treatment step in a multiple-barrier approach to reclaimed water reuse; or be used to establish a salinity barrier system to prevent saltwater intrusion into an aquifer.

• An evaluation of MAR feasibility in four regions—Greater Riyadh area, Madinah Region, Makkah Region, and the Greater Dammam Area—showed that each offers unique opportunities to enhance water resources management using RQTSE for MAR.

• MAR should be a component of a local or regional reuse program wherever feasible, especially where all TSE is currently not being used. MAR will immediately preserve precious water resources and capitalize on the energy invested to produce water with low total dissolved solids levels.

Chapter 6: Water Quality and Wastewater Disposal Impacts The Red Sea and the Arabian Gulf are unique bodies of water with irreplaceable resources that the KSA economy depends on: water supply (after desalination); transportation; fisheries; oil and gas exploration and processing; and unique and diverse intertidal and marine habitats attracting tourism and supporting recreational uses.

• From a water quality standpoint, neither the Red Sea nor the Arabian Gulf is currently highly degraded. However, improperly treated wastewater discharges can cause localized problems in the Red Sea, and more severe, widespread problems in the Gulf.

• Comprehensive water management, including limiting TSE discharges to the Red Sea and the Arabian Gulf, investing in water quality monitoring, and documenting pollutant loads, combined with maximizing reuse, will aid in protecting these valuable resources.

Chapter 7: Regulatory Considerations • The KSA’s RQTSE regulations mostly meet World Health Organization minimum

standards, but RQTSE monitoring and enforcement capabilities are weak.

• Together, two sets of recommended requirements (when implemented) will embody international best practices. The Draft 2010 Saudi Water Act prioritizes reuse as a matter of policy and uses regulations as a driver for reuse promotion and market creation. The Presidency of Meteorology and Environment draft regulations further define standards and application limitations to protect public health.

• The KSA should finalize these draft regulations as soon as possible—delays create uncertainty, limiting potential users’ willingness to invest in technologies and develop a market for reuse.


VIII EXECUTIVE SUMMARY

Chapter 8: Septage Handling and Treatment • Septage is often treated using cesspits or “soak pits” where wastewater collection

systems are not available. These systems frequently are ineffective in treatment and infiltration and require pumping and hauling to a sewage lake or WWTP by truck.

• The biggest gap in dealing with septage is the lack of comprehensive information necessary to assess the problem and develop solutions, particularly for rural areas.

• Where opportunities for treating septage in existing WWTPs are limited, there is a wide range of other potential solutions to treat septage while recovering water, nutrients, and energy from the septage, including land application and decentralized systems.

• The septage issue should be comprehensively assessed so that specific plans can be developed to address this issue on a short-term basis for areas where infrastructure is under development and permanent solutions can be identified for more rural communities.

Chapter 9: Patent Landscape • Patents encourage technology innovation by establishing the proper legal framework and

financial incentives to capitalize on technology opportunities critical for reuse.

• Inventors and investors should review the Strategic Study’s characterization of reuse technology areas considered maturing or emerging. Maturing ones should be considered likely to be more suitable for application today. Emerging ones should be considered potentially attractive investments because they may be able to meet technology needs in the future.

Recommended Path Forward to Successfully Promoting Wastewater Reclamation and Reuse The KSA has embraced a goal to significantly expand the availability of RQTSE for a wide variety of uses. This study is another step forward, identifying technology and data gaps that need to be addressed and opportunities where reuse would support sustainable and integrated water management objectives. Implementing beneficial reuse opportunities will be critical to meeting future water demand, both cost-effectively for users and profitably for providers. Capturing these business opportunities and supporting overall resource sustainability goals will also depend in large part on the following:

• Instituting rational tariff structures for both first use water and RQTSE that support the significant capital and operational investments that will be made, making RQTSE sufficiently attractive as a source.

• Recognizing differences in the ability and willingness to pay in a manner consistent with social and cultural considerations.

• Adopting regulations to support an integrated water resources planning approach.

• Increasing public awareness of the need for RQTSE and gaining acceptance for its use.

• Facilitating collaborative planning by instituting a system (like the proposed National Water Data Center) to better document: water demands; wastewater treated volumes; RQTSE used; and water quality, monitoring, and enforcement data.

• Coordinating specific actions and milestones, including strengthened regulations, to ensure that local, regional, and national goals are met.

The available data confirm that financially sound, practical, and environmentally sustainable opportunities to expand water reuse exist in all regions and in all sectors of the KSA. Creating a pathway to success will protect investments, ensure cost-effectiveness, and facilitate coordination across sectors, provinces, regions, cities, and agencies.

STRATEGIC STUDY

Contents

Acknowledgments ............................................................................................................. iii Preface ................................................................................................................................ iv Executive Summary ............................................................................................................ v Chapter 1: Overview of Water Reuse in Saudi Arabia .................................................. 1-1

1.1 Introduction ................................................................................................. 1-1 1.2 Population Projections ................................................................................ 1-4 1.3 Water Supplies and Demands..................................................................... 1-7

1.3.1 Water Supplies in KSA .................................................................... 1-7 1.3.2 Domestic Water Demands in KSA ................................................... 1-9

1.4 Wastewater Flows ..................................................................................... 1-13 1.5 Water Reuse ............................................................................................. 1-15

1.5.1 Current and Projected RQTSE Use in KSA ................................... 1-16 1.5.2 Wastewater and Reuse in the City of Riyadh ................................. 1-19 1.5.3 Wastewater and Reuse in the City of Jeddah ................................ 1-22 1.5.4 Wastewater and Reuse in the City of Makkah ............................... 1-24 1.5.5 Wastewater and Reuse in the City of Al Taif .................................. 1-25 1.5.6 Wastewater and Reuse in the City of Al Madinah ......................... 1-26 1.5.7 Wastewater and Reuse in the City of Dammam ............................ 1-27

1.6 Wastewater Treatment Processes Used to Produce RQTSE .................... 1-27 1.7 Treatment and Use of Sewage Sludge (Biosolids) .................................... 1-28 1.8 Industrial Water, Wastewater, and Reuse Practices .................................. 1-29

1.8.1 Riyadh ........................................................................................... 1-30 1.8.2 Jeddah and the Makkah Region .................................................... 1-30 1.8.3 Dammam ....................................................................................... 1-30 1.8.4 Al Jubail and Yanbu ...................................................................... 1-31

1.9 Current Status of Reuse Regulations ........................................................ 1-31 1.9.1 Specifications ................................................................................ 1-32 1.9.2 Enforcement .................................................................................. 1-33

1.10 Public Awareness and Acceptance ........................................................... 1-33 1.11 Water, Wastewater, and Reuse Business Status ...................................... 1-34 1.12 Summary .................................................................................................. 1-35 1.13 Information Gap Analysis .......................................................................... 1-35 1.14 References ............................................................................................... 1-37

Chapter 2: Technology Overview .................................................................................... 2-1 2.1 Introduction and Objectives ......................................................................... 2-1 2.2 Current Beneficial Use Schemes and Available Technologies .................... 2-2 2.3 Innovative and Developmental Technologies for Wastewater

Treatment and Water Reuse ....................................................................... 2-5 2.3.1 Innovative and Developmental Physical–Chemical Treatment

Technologies ................................................................................... 2-5 2.3.2 Biological Treatment Technologies ................................................ 2-65 2.3.3 Innovative/Developmental Resource Recovery Technologies ....... 2-83 2.3.4 Innovative/Developmental Phosphorus and Salt Recovery

Technologies ................................................................................. 2-88


XV STRATEGIC STUDY

2.3.5 Natural Treatment Systems ........................................................... 2-96 2.4 Comparison of Innovative/Developmental Technologies ........................... 2-96 2.5 Impact of Wastewater Quality on Operation and Performance of

Treatment Unit Processes ....................................................................... 2-101 2.6 Industries in KSA with Reuse Potential ................................................... 2-102 2.7 Summary and Path Forward ................................................................... 2-106 2.8 References ............................................................................................. 2-108

Chapter 3: Public Education and Awareness to Promote Recycled Water Use ......... 3-1 3.1 Introduction ................................................................................................. 3-1 3.1 Barriers to Reuse Implementation in KSA ................................................... 3-2

3.1.1 Technology, Infrastructure, and Public Trust ................................... 3-2 3.1.2 Socio-Cultural Beliefs and Religious Practices ................................ 3-3 3.1.3 Public Perceptions and Terminology ............................................... 3-4 3.1.4 Water Tariffs in Middle East............................................................. 3-6 3.1.5 Water Resource Management Structure.......................................... 3-6 3.1.6 Regulations and Recycled Water Quality......................................... 3-7

3.2 Proposed Policy, Public Education, and Awareness Actions to Promote Recycled Water Use ................................................................................... 3-8 3.2.1 Organization and Leadership ........................................................... 3-8 3.2.2 Incentives and Penalties .................................................................. 3-9 3.2.3 Surveys and Research .................................................................. 3-10 3.2.4 Key Messages and Implementation Approach ............................... 3-10 3.2.5 Branding Recycled Water .............................................................. 3-11 3.2.6 Build Technical Knowledge ........................................................... 3-11 3.2.7 Demonstration Projects ................................................................. 3-14 3.2.8 Encouraging Urban Agriculture and Vertical Farming .................... 3-14 3.2.9 Exhibitions and Knowledge and Information Centers ..................... 3-16 3.2.10 Mass Media and Public Outreach .................................................. 3-16 3.2.11 Website ......................................................................................... 3-17 3.2.12 Media Relations ............................................................................. 3-18 3.2.13 Social Media .................................................................................. 3-19 3.2.14 Social Events ................................................................................ 3-19 3.2.15 “Road Show” Materials .................................................................. 3-19 3.2.16 In-School Educational Programs ................................................... 3-21

3.3 Gaps and Conclusions .............................................................................. 3-21 3.4 References ............................................................................................... 3-22

Chapter 4: Business Opportunities ................................................................................ 4-1 4.1 Introduction ................................................................................................. 4-1 4.2 The Macro-Case for Reuse: Energy and Sustainability ............................... 4-2 4.3 Potential RQTSE Uses, Market Size, and Growth Trends ........................... 4-3 4.4 Reuse Case Studies: Current Practices and Future Proposals .................. 4-8

4.4.1 Case Studies Drawn from Draft MOWE Regional Planning Reports ......................................................................................... 4-10

4.4.2 Other Case Studies ....................................................................... 4-13 4.5 Formulation of Scenarios for Analysis ....................................................... 4-22

4.5.1 Introduction and Basis for Defining Scenarios ............................... 4-22 4.5.2 Evaluating Business Case by Individual User, Reuse Use

Category, and Reuse Portfolio ....................................................... 4-23 4.5.3 Summary of the Five Scenarios Developed for this Analysis ......... 4-24 4.5.4 Method, Assumptions, and Inputs for Scenario Definition and

Analysis ......................................................................................... 4-25 4.6 Detailed Evaluation of the Five Defined Reuse Scenarios ......................... 4-32

4.6.1 Summary of Financial Results ....................................................... 4-32 4.6.2 Summary of Non-Financial Results ............................................... 4-34 4.6.3 Summary of Overall Scenario Results ........................................... 4-36


STRATEGIC STUDY XIV

4.7 Findings and Recommendations ............................................................... 4-38 4.7.1 Highlights of Major Findings .......................................................... 4-38 4.7.2 Broader Implications and Other Findings ....................................... 4-39 4.7.3 Additional Recommendations to Support Development of

Reuse-Related Business Opportunities ......................................... 4-40 4.8 References ............................................................................................... 4-41

Chapter 5: Aquifer Recharge and Recovery ................................................................... 5-1 5.1 Introduction ................................................................................................. 5-1

5.1.1 Potential Benefits of RQTSE MAR and ASR in KSA ........................ 5-2 5.1.2 General Requirements for Successful RQTSE MAR and ASR ........ 5-3

5.2 MAR and ASR Concepts ............................................................................. 5-4 5.2.1 MAR System Types ......................................................................... 5-4 5.2.2 System Performance Criteria ........................................................... 5-9 5.2.3 KSA MAR General Opportunities .................................................. 5-11

5.3 MAR and ASR Feasibility Issues ............................................................... 5-12 5.3.1 Aquifer Hydraulics and Water Quality ............................................ 5-12 5.3.2 Geochemistry ................................................................................ 5-15 5.3.3 Regulatory and Socio-Cultural Issues ............................................ 5-16

5.4 Water Quality Issues Associated with MAR of RQTSE ............................. 5-17 5.4.1 Introduction ................................................................................... 5-17 5.4.2 Health Risks Associated with RQTSE ........................................... 5-18 5.4.3 Assessment of Health Risks Associated with RQTSE MAR........... 5-19 5.4.4 Pathogenic Attenuation in Aquifers ................................................ 5-20 5.4.5 Chemical Contaminant Attenuation in MAR Systems .................... 5-21 5.4.6 Treatment Strategies ..................................................................... 5-22

5.5 Economic and Operational Issues ............................................................. 5-23 5.5.1 Site Location, Integration into Wastewater Treatment

Infrastructure, and Other Logistical Issues ..................................... 5-23 5.5.2 Well Capacity and Depth ............................................................... 5-24 5.5.3 Well Clogging and Rehabilitation ................................................... 5-25

5.6 General Hydrogeology .............................................................................. 5-26 5.7 Greater Riyadh Area ................................................................................. 5-26

5.7.1 Wadi Aquifers ................................................................................ 5-28 5.8 Makkah Region (Jeddah, Makkah, and Al Taif) ......................................... 5-32

5.8.1 Jeddah .......................................................................................... 5-32 5.8.2 Makkah al Mukarramah ................................................................. 5-33 5.8.3 Al Taif ............................................................................................ 5-34

5.9 Madinah al Munnawarah ........................................................................... 5-34 5.10 Greater Dammam Area ............................................................................. 5-35 5.11 RQTSE ASR Options in KSA .................................................................... 5-40

5.11.1 Evaluation of RQTSE MAR Options .............................................. 5-41 5.11.2 Scoring of KSA MAR Options ........................................................ 5-44

5.12 Conclusions .............................................................................................. 5-46 5.13 References ............................................................................................... 5-46

Chapter 6: Water Quality and Wastewater Disposal Impacts ....................................... 6-1 6.1 Introduction ................................................................................................. 6-1 6.2 Red Sea ...................................................................................................... 6-1

6.2.1 Physical and Hydrographic Characteristics ...................................... 6-1 6.2.2 Uses ................................................................................................ 6-5 6.2.3 Water Quality .................................................................................. 6-5 6.2.4 Pollutant Sources and Overall Water Quality ................................. 6-10

6.3 Arabian Gulf .............................................................................................. 6-15 6.3.1 Physical and Hydrographic Characteristics .................................... 6-15 6.3.2 Uses .............................................................................................. 6-17 6.3.3 Water Quality ................................................................................ 6-18


XV STRATEGIC STUDY

6.3.4 Pollutant Sources and Overall Water Quality ................................. 6-20 6.4 Sewage Lakes .......................................................................................... 6-25 6.5 Gap Analysis ............................................................................................. 6-26

6.5.1 Monitoring ..................................................................................... 6-26 6.5.2 Pollutant Loading ........................................................................... 6-26 6.5.3 Collaborative Efforts ...................................................................... 6-26

6.6 Summary .................................................................................................. 6-27 6.7 References ............................................................................................... 6-28

Chapter 7: Regulatory Considerations ........................................................................... 7-1 7.1 Introduction ................................................................................................. 7-1 7.2 Current Status of Reuse Regulations .......................................................... 7-3

7.2.1 Treated Sanitary Wastewater and Its Reuse Regulations ................ 7-4 7.2.2 General Environmental Regulations and Rules for Implementation . 7-4 7.2.3 MOWE Guidance: Using Treated Water for Irrigation; Controls-

Conditions-Offences and Penalties.................................................. 7-4 7.2.4 Compliance, Monitoring, and Enforcement ...................................... 7-7

7.3 Proposed Regulations ................................................................................. 7-8 7.3.1 Draft 2010 Saudi Water Act ............................................................. 7-8 7.3.2 Draft Implementation Regulations: Treated Wastewater and

Its Reuse ......................................................................................... 7-9 7.3.3 Summary of Proposed Regulations ............................................... 7-13

7.4 International Best Management Practices ................................................. 7-13 7.4.1 The World Health Organization ..................................................... 7-14 7.4.2 United States ................................................................................. 7-16 7.4.3 European Union ............................................................................ 7-18 7.4.4 Australia ........................................................................................ 7-18 7.4.5 Singapore ...................................................................................... 7-19 7.4.6 Biosolids ........................................................................................ 7-19

7.5 Implementation Recommendations ........................................................... 7-20 7.5.1 Coordination among Various Agencies and Private Sector ............ 7-20 7.5.2 Regulatory Efforts .......................................................................... 7-21 7.5.3 Monitoring ..................................................................................... 7-22 7.5.4 Reporting ....................................................................................... 7-23 7.5.5 Enforcement .................................................................................. 7-24


Chapter 8: Septage Handling and Treatment ................................................................. 8-1 8.1 Introduction ................................................................................................. 8-1

8.1.1 Septage Overview ........................................................................... 8-1 8.1.2 Objectives ....................................................................................... 8-1 8.1.3 Lessons Learned from the Jeddah Situation .................................... 8-2

8.2 Current Status of Septage Handling and Treatment .................................... 8-6 8.2.1 Current Methods for Handling and Transporting Septage ................ 8-6 8.1.4 Septage Treatment Needs .............................................................. 8-7 8.1.5 Potential Problems Associated with Septage Disposal .................... 8-9

8.2 Solutions for Septage Handling and Treatment ......................................... 8-10 8.2.1 Septage Handling and Treatment Options ..................................... 8-10 8.2.2 Removal of Septage Lakes ........................................................... 8-14


Chapter 9: Patent Landscape .......................................................................................... 9-1 9.1 Introduction and Objectives ......................................................................... 9-1 9.2 Methodology ............................................................................................... 9-1

9.2.1 Distortion Caused by Trends in Japan ............................................. 9-2 9.3 Overview of Water Reuse Technology Patent Landscape ........................... 9-3


STRATEGIC STUDY XIV

9.3.1 Technology Categories .................................................................... 9-3 9.3.2 Trends in Patenting Activity by Geography ...................................... 9-4 9.3.3 Trends in Patenting Activity Over Time ............................................ 9-5 9.3.4 Leading Patent Assignees ............................................................... 9-6 9.3.5 Key Findings at Overview Level ...................................................... 9-8

9.4 Category 1: Disinfection .............................................................................. 9-8 9.4.1 Key Findings ................................................................................... 9-8 9.4.2 Analysis of Disinfection Portfolio ...................................................... 9-9 9.4.3 Landscape: Oxidation .................................................................... 9-12

9.5 Category 2: Removal/Recovery and Petrochemical Technologies ............ 9-14 9.5.1 Key Findings ................................................................................. 9-14 9.5.2 Analysis of Removal/Recovery and Petrochemical Technologies

Portfolio ......................................................................................... 9-16 9.6 Category 3: Sludge Treatment Technologies ............................................ 9-17

9.6.1 Key findings ................................................................................... 9-17 9.6.2 Analysis of Sludge Treatment Portfolio .......................................... 9-18

9.7 Category 4: Bioreactors and Microbial Technologies ................................ 9-20 9.7.1 Key Findings ................................................................................. 9-20 9.7.2 Analysis of Biological Treatment Portfolio ...................................... 9-21 9.7.3 Landscape: Bioreactors ................................................................. 9-23 9.7.4 Landscape: Anaerobic Treatment .................................................. 9-25

9.8 Category 5: Filtration, Membranes, and Solids .......................................... 9-25 9.8.1 Key Findings ................................................................................. 9-26 9.8.2 Analysis of Separation Portfolio ..................................................... 9-28 9.8.3 Landscape: Forward Osmosis ....................................................... 9-29

9.9 Category 6: Ecosystems, Domestic, and Miscellaneous ........................... 9-30 9.9.1 Key Findings ................................................................................. 9-31 9.9.2 Analysis of Ecosystems, Domestic, and Miscellaneous Portfolio ... 9-32


Appendixes

A-1 Established Physical-Chemical, Biological, and Natural Treatment Technologies A-2 Commercially Available Resource Recovery and Biogas Generation Technologies B Additional Detail for ProjectSelectTM Assumptions: Wastewater Treatment and

Reuse Conveyance Cost Assumptions


XV STRATEGIC STUDY

Tables

1-1 Overview of Regions and Major Cities .................................................................... 1-4 1-2 Population Growth Percentages from 2010 through 2035....................................... 1-5 1-3 Year 2010 Census Population and Projections for Years 2025 and 2035 ............... 1-6 1-4 Year 2010 Census Population and Projections for Years 2025 and 2035 for Six

Largest Cities in KSA .............................................................................................. 1-6 1-5 Existing Water Sources and Supplies ..................................................................... 1-8 1-6 Calculated Water Demands .................................................................................. 1-10 1-7 Water Supply and Demand in Largest Cities ........................................................ 1-12 1-8 Projected Wastewater Flows and WWTP Status in Each Region ......................... 1-14 1-9 Wastewater Flows in Largest Cities ...................................................................... 1-15 1-10 Reuse Applications by Primary and Sub-Category ............................................... 1-18 1-11 Summary of Major Existing WWTPs and Reuse Status in Riyadh ........................ 1-21 1-12 Future Reuse Amounts in City of Riyadha ............................................................ 1-22 1-13 Summary of Existing WWTPs and Reuse Status in Jeddah ................................. 1-23 1-14 Summary of Existing WWTPs and Reuse Status in Makkah ................................. 1-25 1-15 Summary of Existing WWTP and Reuse Status in Al Taif ..................................... 1-26 1-16 Summary of WWTP and Reuse Status in Al Madinah .......................................... 1-26 1-17 Summary of Existing WWTP and Reuse Status in Dammama ............................. 1-27 1-18 Current and Projected Future Use of RQTSE in Riyadh ....................................... 1-30 2-1 Effectiveness of Combined-Disinfectant Technologies ......................................... 2-56 2-2 Summary and Comparison of Innovative/Developmental Desalination

Technologies ........................................................................................................ 2-97 2-3 Summary and Comparison of Innovative/Developmental Disinfection

Technologies ........................................................................................................ 2-98 2-4 Comparison of Filtration Technologies.................................................................. 2-99 2-5 Summary and Comparison of Innovative/Developmental Biological Treatment

Technologies ...................................................................................................... 2-100 2-6 Summary and Comparison of Side Stream Treatment Technologies .................. 2-101 2-7 Wastewater Quality Parameters and Their Impacts on Operation and

Performance of Unit Treatment Processes ......................................................... 2-103 4-1 Energy Requirements of Commonly Used Reuse and Seawater Desalination

Technologies .......................................................................................................... 4-3 4-2 Reuse Applications by Primary and Sub-Category ................................................. 4-4 4-3 Reuse Sector Growth Rates and Associated Statistics ........................................... 4-7 4-4 Summary Data from 68 Reuse Case Studies Detailed in the Draft MOWE

Regional Planning Reports ................................................................................... 4-11 4-5 Observations about Draft MOWE Regional Planning Reports’ Case Study

Statistics by Sub-Group Relative to the Entire Set ............................................... 4-12 4-6 Phase I (Wastewater Quality and Treated Water Quality Objectives) ................... 4-14 4-7 Phase II (Wastewater Quality and Treated Water Quality Objectives) .................. 4-15 4-8 Summary of Economic Evaluation Results: SABIC Water Reuse Study ............... 4-15 4-9 Summary of Economic Evaluation Results: Jeddah Industrial City Textile

Processing Industry .............................................................................................. 4-16 4-10 Summary of Capital Investment and Payback Period for Water Recycling at

MEPCO Paper Facility in Jeddah City .................................................................. 4-18 4-11 Summary of Capital Investment and Payback Period for ARAMCO

Refinery Reuse ..................................................................................................... 4-18 4-12 Scenario Scoring System ..................................................................................... 4-31 5-1 RQTSE MAR Techniques ....................................................................................... 5-1 5-2 General Geological Structure of the Greater Riyadh Area .................................... 5-29 5-3 General Geological Structure of the Greater Dammam Area ................................ 5-36 5-4 RQTSE ASR and MAR Feasibility Scoring System Summary .............................. 5-42 5-5 Feasibility Scoring of RQTSE MAR Options ......................................................... 5-44


STRATEGIC STUDY XIV

6-1 Marine Pollution Emissions from Red Sea Coastal Provinces in KSA ................... 6-11 6-2 Estimated Red Sea Pollutants Generated by Saudi Arabia’s Municipal

Sewage Treatment ............................................................................................... 6-12 6-3 Artisanal Ports of Landing in Saudi Arabia (2000) ................................................ 6-17 6-4 Estimated Wastewater Discharges from Saudi Arabia to the Arabian Gulf ........... 6-21 6-5 Major Port and Other Industry Pollutant Sources .................................................. 6-24 7-1 Summary of Water Quality Parameters of Concern for Water Reuse ..................... 7-3 7-2 Maximum Chemical Criteria for Sludge Application in Agriculture ........................... 7-6 7-3 Maximum Biological Criteria for Sludge Application in Agriculture .......................... 7-7 7-4 Proposed Monitoring Requirements for WWTPs .................................................. 7-10 7-5 Maximum Containment Levels for RQTSE Contaminants in Wastewater

Receiving Secondary and Tertiary Treatment ....................................................... 7-11 7-6 International Examples of Reuse Standards ......................................................... 7-15 7-7 California Reuse Application Rules by Treatment Category .................................. 7-17 7-7 Definitions of Monitoring Functions ....................................................................... 7-22 8-1 Criteria for Evaluating Acceptability of Trucked Wastewater at NWC Facilities ...... 8-7 8-2 2010 Untreated Wastewater Flows in KSA, by Region ........................................... 8-8 9-1 Categories within Patent Portfolio ........................................................................... 9-3 9-2 Top Assignees of Patents and Published Applications ........................................... 9-7 9-3 Leading Patent Assignees, by Geography and Technology Category .................. 9-11 9-4 Leading Patent Inventors, by Geography and Technology Category .................... 9-11 9-5 Leading Patent Assignees, by Geography and Technology Subcategory ............. 9-15 9-6 Leading Patent Inventors, by Geography and Technology Subcategory ............... 9-16 9-7 Leading Patent Assignees, by Geography and Technology Subcategory ............. 9-19 9-8 Leading Patent Inventors, by Geography and Technology Subcategory ............... 9-20 9-9 Leading Patent Assignees, by Geography and Technology Subcategory ............. 9-22 9-10 Leading Patent Inventors, by Geography and Technology Subcategory ............... 9-23 9-11 Leading Patent Assignees, by Geography and Technology Subcategory ............. 9-29 9-12 Leading Patent Inventors, by Geography and Technology Subcategory ............... 9-29 9-13 Leading Patent Assignees, by Geography and Technology Subcategory ............. 9-33 9-14 Leading Patent Inventors, by Geography and Technology Subcategory ............... 9-33 9-15 Status of Key Technology Areas Relevant to KSA Water Treatment for

Reuse Applications Implied by Patent Analysis .................................................... 9-34

Figures

1-1 Existing Urban Water Cycle in the Kingdom of Saudi Arabia .................................. 1-1 1-2 KSA and Political Regions ...................................................................................... 1-3 1-3 Major Water Provinces in KSA ............................................................................... 1-7 1-4 Total Existing Water Sources by Region ................................................................. 1-8 1-5 Domestic Water Usage in Select Countries ............................................................ 1-9 1-6 Locations of Major Desalination Facilities in KSA ................................................. 1-11 1-7 Existing and Projected Future RQTSE Production by Region in 2010,

2025, and 2035 .................................................................................................... 1-16 1-8 Proposed RQTSE Use Amounts by Region by Type in Year 2025

Shown as Percent of Total .................................................................................... 1-17 1-9 Existing and Projected Future RQTSE Use by Type in KSA ................................. 1-17 1-10 Total Existing and Projected Future RQTSE Use by Type in KSA ........................ 1-18 1-11 City of Riyadh Major Wastewater Treatment Facilities .......................................... 1-19 1-12 Aerial View of the Wadi Hanifa, 2009 / A series of natural stone weirs built to

introduce oxygen into the water ............................................................................ 1-20 1-13 Projections of Future Reuse by Sector and Estimates of Available

RQTSE in the City of Riyadh ................................................................................ 1-22 1-14 City of Jeddah Major Wastewater Treatment Facilities ......................................... 1-24


XV STRATEGIC STUDY

1-15 City of Makkah Major Wastewater Treatment Facilities ........................................ 1-25 1-16 City of Al Madinah Major Wastewater Treatment Facility ...................................... 1-26 1-17 Process Schematic of BNR CAS and Integrated Filtration and Disinfection

Facilities to Produce RQTSE ................................................................................ 1-28 1-18 Process Schematic of BNR MBR and Integrated Disinfection

Facilities to Produce RQTSE ................................................................................ 1-28 1-19 Agricultural Reuse Categories .............................................................................. 1-32 2-1 Examples of Reclaimed Water Schemes ................................................................ 2-2 2-2 Examples of Reclaimed Water Schemes for High-Quality Uses ............................. 2-3 2-3 Examples of Intended Use with Full Treatment ....................................................... 2-4 2-4 CD Operation and Regeneration ............................................................................ 2-6 2-5 Schematic Illustration of FO and RO ...................................................................... 2-9 2-6 Simplified Process Schematic of FO ..................................................................... 2-10 2-7 ARROW Process Schematic ................................................................................ 2-14 2-8 New Jersey ARROW Project for Reject Recovery ................................................ 2-15 2-9 OPUSTM Process Schematic (Courtesy of N.A. Water Systems) ......................... 2-16 2-10 SPARRO Process Schematic (Adapted from CH2M HILL, 2009) ......................... 2-19 2-11 Illustration of Tubular Membranes Used in SPARRO ............................................ 2-20 2-12 Operating Principles of ZDD ................................................................................. 2-21 2-13 ZDD™ Process Schematic (Courtesy of Veolia Water Solutions) ......................... 2-22 2-14 Simplified Process Schematic of HDH (Adapted from Narayan et al., 2010) ......... 2-23 2-15 Simplified Process Schematic of Multi Effect HDH................................................ 2-24 2-16 Dewvaporation Process Schematic ...................................................................... 2-25 2-17 Altela Rain Dewvaporation System ....................................................................... 2-26 2-18 HIX-NF Process Schematic .................................................................................. 2-29 2-19 Schematic of Air-Cathode MDCs .......................................................................... 2-31 2-20 Schematic of Air Gap MD ..................................................................................... 2-33 2-21 Schematic of Nanotechnologically Advanced RO Membrane ............................... 2-38 2-22 Schematic of Four-Bed Adsorption Desalination ................................................... 2-39 2-23 Schematic of Solar Desalination ........................................................................... 2-41 2-24 Solar Desalination Options ................................................................................... 2-42 2-25 Schematic Illustration of Ferrate Production ......................................................... 2-45 2-26 Schematic of Pasteurization ................................................................................. 2-49 2-27 Layout of Field Experiments ................................................................................. 2-57 2-28 Process Schematic of Ceramic Membrane Filtration ............................................ 2-60 2-29 CoMag Process Schematic .................................................................................. 2-62 2-30 Ecosphere OzonixTM System ................................................................................ 2-64 2-31 Simplified Process Schematic of AnMBR ............................................................. 2-66 2-32 Simplified Process Schematic of AMBR ............................................................... 2-68 2-33 Process Schematic of MBfR ................................................................................. 2-71 2-34 Pilot MSABP ......................................................................................................... 2-74 2-35 Process Schematic of SHARONTM........................................................................ 2-76 2-36 Process Schematic of SHARONTM /ANOMMOX® ................................................. 2-79 2-37 Process Schematic of DEMONTM ......................................................................... 2-80 2-38 Process Schematic of Huber VRM Module ........................................................... 2-82 2-39 Process Schematic of Algae Biodiesel (Adapted from CH2M HILL, 2007) ............ 2-84 2-40 Algae Biodiesel Reactor Examples (Adapted from CH2M HILL, 2007) ................. 2-84 2-41 Schematic of (Courtesy of Columbia University, Dr. Chandran) ........................... 2-86 2-42 Schematic Illustration of Microbial Fuel Cell ......................................................... 2-87 2-43 Process Schematic of Crystalactor® (www.dhv.com) ........................................... 2-89 2-44 Process Schematic of the P-RoC Technology (Berg et al., 2005) ......................... 2-90 2-45 OSTARA’s Struvite Recovery Process ................................................................. 2-91 2-46 SAL-PROC Process Schematic ............................................................................ 2-93 2-47 Process Schematic of Greenhouse Drying Process (Huber Technology) ............. 2-95 2-48 Luggage Point Potable Reuse Plant Schematic .................................................. 2-107


STRATEGIC STUDY XIV

3-1 Total Existing and Projected Future Reuse Use by Type in KSA ............................ 3-2 3-2 Water Cycle as Typically Depicted ....................................................................... 3-12 3-3 What the Future Might Hold with Enhanced Urban Water Reuse .......................... 3-13 3-4 Screen Captures from NEWater Computer Program (PUB, 2011) ........................ 3-17 4-1 Reuse Projections, Country-Wide by Use Type ...................................................... 4-5 4-2 Proposed Reuse Amounts: by Type for Regions, 2025 .......................................... 4-5 4-3 Proposed Reuse Amounts: by Type for Regions as a Percent of

Regional Total, 2025 .............................................................................................. 4-6 4-4 Proposed Reuse Amounts: by Type for Cities with Industrial Reuse, 2025 ............. 4-6 4-5 Proposed Reuse Amounts: By Type for Cities with Industrial Reuse as

Percent of City Group Total, 2025 .......................................................................... 4-7 4-6 Proposed Reuse Amounts for Regions: Agriculture, Imputed Annual Growth

Rate for 2010-2025 and 2025-2035 ........................................................................ 4-8 4-7 Proposed Reuse Amounts for Regions: Landscaping, Imputed Annual Growth

Rate for 2010-2025 and 2025-2035 ........................................................................ 4-9 4-8 Proposed Reuse Amounts for Regions: Industry, Imputed Annual Growth

Rate for 2010-2025 and 2025-2035 ........................................................................ 4-9 4-9 Proposed Reuse Amounts for Regions: Recreation, Imputed Annual Growth

Rate for 2010-2025 and 2025-2035 ...................................................................... 4-10 4-10 Cost-Benefit Ratios for 64 Project Examples from the Draft MOWE Regional

Planning Reports .................................................................................................. 4-12 4-11 Cost-Benefit Ratios for 55 Project Examples from the Draft MOWE Regional

Planning Reports .................................................................................................. 4-12 4-12 MEPCO’s Approach for Wastewater Treatment and Recycling in

Jeddah City Facility .............................................................................................. 4-17 4-13 PEARL 500 Reactors in Durham AWTF (Courtesy of Ostara Nutrient Recovery

Technologies) ....................................................................................................... 4-20 4-14 Specification of Scenario Flows, Existing Infrastructure, Reuse Quality, and

Reuse Allocations ................................................................................................. 4-26 4-15 Projected Flows, Rates, and Revenues for the Five Scenarios ............................. 4-27 4-16 Wastewater Treatment Costs for 50,000 m3/d of Reuse Capacity for Different

Pre-Existing Infrastructure Assumptions ............................................................... 4-29 4-17 Reuse Conveyance Cost Assumptions ................................................................. 4-29 4-18 Total Costs for Reuse Scenarios .......................................................................... 4-30 4-19 Narrative Rating for Each Criterion and Each Scenario and Corresponding Raw

Numerical Score ................................................................................................... 4-31 4-20 Summary of Financial Results for the Scenarios .................................................. 4-32 4-21 Graphic Presentation of Financial Parameters for Each Scenario......................... 4-33 4-22 Net Cash Flows for the Reuse Scenarios ............................................................. 4-33 4-23 Net Cash Flows Charts for the Individual Scenarios Also Showing Capital

Investments, Operating Costs, and Revenues ...................................................... 4-34 4-24 Component Weighted Scores for Non-Financial Criteria ....................................... 4-35 4-25 Graphic Presentation of Component Weighted Scores for Non-Financial Criteria . 4-35 4-26 Summary of Financial and Non-Financial Results for the Scenarios ..................... 4-37 5-1 Conceptual Diagram of ASR Using Brackish Storage Zone .................................... 5-5 5-2 Conceptual Diagram of Physical Storage ASR System .......................................... 5-6 5-3 Conceptual Diagram of ASTR System .................................................................... 5-7 5-4 Conceptual Diagram of Salinity Barrier System ...................................................... 5-8 5-5 Conceptual Diagram of SAT System ...................................................................... 5-9 5-6 Conceptual Diagram of Wadi ASTR System ......................................................... 5-12 5-7 Conceptual Diagram of Density-driven Movement of Freshwater Injected into

Saline Water in ASR System ................................................................................ 5-13 5-8 Conceptual Diagram of Matrix-dominated versus Conduit Flow ............................ 5-14 5-9 Geological map of the Arabian Peninsula ............................................................. 5-27 6-1 Bathymetry of the Red Sea ..................................................................................... 6-4


XV STRATEGIC STUDY

6-2 Bathymetry of the Arabian Gulf ............................................................................. 6-16 7-1 Timeline of KSA Actions to Promote Reuse ............................................................ 7-1 7-2 Typical Parameters of Concern for Reuse Applications .......................................... 7-2 7-3 Agricultural Reuse Categories ................................................................................ 7-5 7-4 Potable Water Augmentation ................................................................................ 7-18 8-1 Estimated Wastewater Balance for Jeddah in 2005 Highlighting Lack of

Wastewater Collection System ............................................................................... 8-2 8-2 Location of Jeddah Sewage Lake Relative to Municipality of Jeddah ..................... 8-3 8-3 Trucks in Line and Dumping Wastewater Near Jeddah Sewage Lake .................... 8-4 8-4 Views of the Jeddah Sewage Lake on 25 July 2010 When Evacuation Effort had

been Underway 2 Weeks and on 5 October 2010 ................................................. 8-5 8-5 Views of Former Jeddah Sewage Lake in July 2011 .............................................. 8-5 8-6 Septage Handling Options ...................................................................................... 8-6 8-7 Wastewater Truck that had been Turned Away from WWTP Dumping

Wastewater along Roadside ................................................................................... 8-7 8-8 Projected Wastewater Treatment Capacity Shortfalls in KSA Regions .................. 8-9 8-9 Photographs of Reed Bed Effluent Polishing System Followed by Storage

Basin for RQTSE ................................................................................................. 8-12 8-10 Process Flow Diagram of North Shouneh Septage Treatment Facility .................. 8-14 9-1 Breakdown of Patent Portfolio by Technology Category ......................................... 9-4 9-2 Overlap between Technology Categories ............................................................... 9-4 9-3 Patenting Activity (Published Applications and Granted Patents) by Geography .... 9-5 9-4 Patent Pipeline – Published Applications versus Granted Patents, by Geography,

2000-09 .................................................................................................................. 9-5 9-5 Patent Filings over Time by Geography .................................................................. 9-6 9-6 Change in Patenting Activity over Time – by Technology Category and

Geography ............................................................................................................. 9-7 9-7 Breakdown of Patent Portfolio by Technology Subcategory, 2000-09 ................... 9-10 9-8 Change in Patenting Activity over Time – by Technology Subcategory and

Geography ........................................................................................................... 9-10 9-9 Landscape of Oxidation-Related Technologies 2005-2010 ................................... 9-13 9-10 Breakdown of Patent Portfolio by Technology Subcategory .................................. 9-16 9-11 Change in Patenting Activity over Time – by Technology Subcategory and

Geography ........................................................................................................... 9-17 9-12 Breakdown of Patent Portfolio by Technology Subcategory .................................. 9-18 9-13 Change in Patenting Activity over Time – by Technology Subcategory and

Geography ........................................................................................................... 9-19 9-14 Breakdown of Patent Portfolio by Technology Subcategory .................................. 9-21 9-15 Change in Patenting Activity over Time – by Technology Subcategory and

Geography ........................................................................................................... 9-22 9-16 Landscape of Bioreactor-Related Technologies 2005-2010 .................................. 9-24 9-17 Landscape of Anaerobic-Related Technologies 2005-2010 .................................. 9-26 9-18 Breakdown of Patent Portfolio by Technology Subcategory .................................. 9-28 9-19 Change in Patenting Activity over Time – by Technology Subcategory and

Geography ........................................................................................................... 9-28 9-20 Landscape of Forward Osmosis-Related Technologies 2005-2010 ...................... 9-30 9-21 Breakdown of Patent Portfolio by Technology Subcategory .................................. 9-32 9-22 Change in Patenting Activity over Time – by Technology Subcategory and

Geography ........................................................................................................... 9-32 Acronyms and Abbreviations .............................................................................................

STRATEGIC STUDY

Chapter 1: Overview of Water Reuse in Saudi Arabia

1.1 Introduction Water reclamation and reuse has become an important worldwide total water management topic over the last 30 years as the limitations of freshwater resources have come into sharp focus. In the Kingdom of Saudi Arabia (KSA), potable water is produced from either non-renewable or very slowly renewable water resources such as groundwater or capital- and energy-intensive seawater desalinations. Much of the potable water produced from these costly and non-renewable sources is used for non-potable purposes, and these existing sources and treatment methods will not sustainably meet the future potable and non-potable water demands in most regions of KSA.

Reserving the use of expensive potable water for truly potable needs will extend the life of these valuable resources. Fortunately, non-potable demands can be met by using a sustainable resource that is available in KSA – reclaimed water. Considering strategies that include water reuse as an essential component of integrated water resources management to ensure that present water needs and future demands are met cost-effectively and in a sustainable manner is a rapidly growing trend especially in water-scarce regions. Figure 1-1 depicts the urban water cycle that is currently in place in many of the largest cities in KSA; water is reclaimed by advanced treatment and then used in urban settings primarily for landscaping and irrigation. The use of reclaimed water in industrial settings is increasing, and additional markets are developing.

FIGURE 1-1 Existing Urban Water Cycle in the Kingdom of Saudi Arabia Modified Water Cycle [Adapted and used from “Talking About Water” (WRF-07-03), Copyright 2011, with permission from the WateReuse Research Foundation.

CHAPTER 1: OVERVIEW OF WATER REUSE IN SAUDI ARABIA

1-2 STRATEGIC STUDY

Reclaimed water is produced by treating wastewater so that it can be safely reused for non-potable needs such as industrial processes and cooling, agricultural irrigation, landscaping, groundwater recharge, and ecosystem creation or restoration. The primary drivers for reuse are:

• Increasing populations create water demands that cannot sustainably be met using only the existing water sources and treatment technologies.

• Meeting new demands will require very significant capital and operation and maintenance (O&M) investment in new desalination plants and groundwater wells.

• The use of alternative water resources such as reclaimed water can reduce the infrastructure needed for new potable water supplies.

• The need to prevent seawater intrusion and replenish groundwater sources.

• Increasingly stringent wastewater quality discharge requirements will necessitate significant capital and O&M investments to meet new discharge standards.

• By discharging highly treated wastewater to the sea or other surface waters, the return on the investments made in purifying the water for drinking and then treating it to stringent levels to discharge is lost because the water is not reused.

• Reduces energy used for treatment and conveyance.

• Using the reclaimed water, rather than discharging it to surface waters, minimizes the discharge of pollutants to surface waters.

Reuse water that has been treated to meet the standards adopted by the KSA Ministry of Water and Electricity (MOWE) is typically referred to as reuse quality treated sewage effluent (RQTSE). In this Strategic Study, other terms such as “recycled water” and “reclaimed water” are also used in certain contexts to refer to this highly treated product. Depending on its level of treatment, RQTSE may be used for either restricted or unrestricted uses, as defined in Section 1.9. Other wastewater that receives lower levels of treatment is referred to as treated wastewater or treated sewage effluent (TSE).

The purpose of this chapter is to describe the current status of water reuse in KSA as well as information about water demands and wastewater treatment, reuse, and disposal. Water demands and wastewater flow projections have been developed based on the 2010 census population, as described in this chapter. In addition, information about water, wastewater, and reuse was provided by MOWE for the purposes of this Strategic Study. At the time of this writing, MOWE’s 13 Regional Planning Reports were considered drafts under review (ItalConsult, 2009-2010).

This chapter also provides an overview of existing regulations that are applicable to reuse and biosolids management, as well as an assessment of major barriers to more comprehensive water reuse and biosolids use in KSA. In addition, this chapter identifies gaps in information and policy that should be addressed to achieve KSA’s goals.

KSA has a number of goals for providing infrastructure for water, wastewater, and reuse in cities with populations greater than 5,000 people. In general, it is planned that the

Benefits of Water Reuse

• Reduces demand on non-renewable water resources or resources that renew very slowly such as groundwater

• Allows the initial high cost of purifying water for drinking to be recouped since the water is beneficially reused

• Reduces energy used for treatment and conveyance

• Minimizes discharge to surface waters, thus minimizing pollutant discharges

• Less expensive for cooling than highly treated desalinated water for industries, commercial enterprises, and possibly public buildings

• Lowers the cost of infrastructure for new potable supplies

• Helps prevent saltwater intrusion and replenish groundwater resources


STRATEGIC STUDY 1-3

coverage for water supply and sewage collection will be nearly 100 percent in these cities by the Year 2025. It is also planned that nearly all of the sewage collection systems will be connected to wastewater treatment plants (WWTPs) by the Year 2025. Further, it is planned that all RQTSE will be beneficially reused (ItalConsult, 2009-2010).

It is important to understand the role of the National Water Company (NWC) in meeting these infrastructure goals. The NWC was created by Royal Decree in January 2008 and is a public company owned by the government. The NWC Board is chaired by the Minister of Water and Electricity. NWC’s mission is to restructure and provide drinking water and wastewater services in accordance with the latest international standards through privatization and working with various international operators. The NWC is described further in Section 1.11. MOWE maintains its strategic role in establishing the National Water Plan and introducing laws and legislation that regulate water and wastewater services in the Kingdom. MOWE also continues to provide water and wastewater services in cities yet to be privatized.

Planning efforts for water, wastewater, and reuse infrastructure are generally more developed for the six largest cities in KSA: Riyadh, Jeddah, the Holy City of Makkah, Al Taif, the Holy City of Madinah, and Dammam. This chapter presents detailed information about water, wastewater, and reuse in these six cities and more generalized information about the remaining regions. The NWC is currently responsible for water and wastewater services in Riyadh, Jeddah, Makkah and Al Taif. It will soon become responsible for services in Al Madinah and Dammam.

KSA consists of 13 regions, as shown in Figure 1-2. An overview of each region, including the primary activities of the region and the largest cities in KSA, is provided in Table 1-1. Based on the Year 2010 census, there were over 27 million people within the 13 regions of KSA, ranging from over 320,000 in the Northern Borders Region to 4.1 million in the Eastern Province, and nearly 7 million in both the Makkah and Riyadh Regions.

Riyadh is the national capital and largest city in KSA. Three of the other largest cities in the country – Jeddah, Makkah, and Al Taif – are located within the Makkah Region. According to the 2010 census, the population in the Kingdom’s six largest cities totaled nearly 13.5 million people, which was half of the total KSA population.

MOWE Infrastructure Goals for Cities >5,000 People • Cities will be nearly 100%

served with water supply and sewage collection systems by 2025.

• Nearly all sewage collection systems will be connected to WWTPs by 2025.

• All RQTSE will be beneficially reused.

FIGURE 1-2

KSA and Political Regions


1-4 STRATEGIC STUDY

TABLE 1-1 Overview of Regions and Major Cities

Region Total Area

(km2)a,b Classificationc 2010 Census Populationa,b Major Citiesa,b,c

Al Baha 9,900 Tourism 411,900

Al Jouf 100,200 Desert 440,000

Assir 76,700 Agriculture 1,913,400

Eastern Province

672,500 Industry, Empty Quarter Desert

4,105,800 Dammam Population: 904,000 Activities: Agriculture; Port; Industry

Hail 103,900 Desert 597,100

Jizan 11,700 Agriculture 1,365,100

Madinah 152,000 Agriculture, Tourism 1,777,900 Al Madinah Population: 1,181,000 Activities: Agriculture, Tourism

Makkah 153,100 Tourism, Industry, Business Center, Port, Agriculture

6,915,000 Jeddah

Population: 3,456,000

Activities: Industry; Port

Makkah

Population: 1,675,000

Activities: Tourism

Al Taif

Population: 988,000

Activities: Agriculture

Najran 149,500 Agriculture 505,700

Northern Borders

111,800 Desert 320,500

Qaseem 58,000 Agriculture 1,215,900

Riyadh 404,200 National Capital, Industry, Desert

6,777,100 Riyadh

Population: 5,255,000 Activities: National Capital

Tabouk 146,000 Agriculture 791,500

Totals 2,149,500 27,136,900 a www.geohive.com; 2010 Census Population b Numbers have been rounded c ItalConsult (2009-2010) km2 = square kilometer

1.2 Population Projections The KSA Central Department of Statistics and Information (CDSI) published the results of the 2010 population census (www.cdsi.gov.sa) listing the population of the Kingdom as 27,136,900. Another source (www.geohive.com) reported the same total population and also provided population information by regions and cities. The 2004 census population was 22,678,300. In the 6 years between 2004 and 2010, the population of KSA increased at approximately 3.2 percent per year.

The KSA Ministry of Planning, Statistics Department prepared population projections from Year 2010 through Year 2021 by region, in 5-year increments (ItalConsult 2009-2010). The growth percentages were calculated from the Ministry’s population projections and are presented in the first two columns of Table 1-2.


STRATEGIC STUDY 1-5

The population growth projection from 2010 to 2015 is approximately 2 percent per year; this rate is supported in the Global Water Market 2011 Report (Global Water Intelligence, 2011). Based on the information contained in the Draft MOWE Regional Planning Reports (ItalConsult, 2009-2010), the percentages shown in the last three columns of Table 1-2 were applied to project population growth through 2035.

To calculate population projections for 2025 and 2035, the percentages presented in Table 1-2 were applied to the 2010 census population figures. The populations for 2025 and 2035 are presented in Table 1-3. The growth in population in KSA and particularly in the six largest cities will significantly increase water demands, as described in the next section. In addition, the projected growth will increase wastewater flows but will also provide important opportunities for reuse of RQTSE to offset water demands.

The population of the six largest cities in the Kingdom, as shown in Table 1-4, is projected to increase by approximately 55 percent from 13.5 million in 2010 to nearly 21 million in 2035. Nearly half of the Kingdom’s population is projected to live in the six largest cities in 2035 and nearly 20 percent of the KSA’s population is projected to live in Riyadh in that year.

TABLE 1-2 Population Growth Percentages from 2010 through 2035

Population Growth Percentages in 5-Year Increments

Region 2010–2015a 2015–2020a 2020–2025b 2025–2030b 2030–2035b

Al Baha 9.5 9.6 8.5 8.5 8.5

Al Jouf 10.7 9.3 8.3 8.3 8.3

Assir 10.5 9.6 8.5 8.5 8.5

Eastern Province 10.4 9.4 8.4 8.4 8.4

Hail 10.7 9.6 8.5 8.5 8.5

Jizan 12.1 9.5 8.5 8.5 8.4

Madinah 11.5 9.5 8.4 8.4 8.4

Makkah 10.4 9.5 8.5 8.5 8.5

Najran 9.2 9.3 8.3 8.3 8.3

Northern Borders 12.4 9.5 8.5 8.5 8.5

Qaseem 10.9 9.5 8.4 8.4 8.4

Riyadh 11.4 9.0 9.0 8.6 8.6

Tabouk 12.1 9.5 8.5 8.5 8.5

a Calculated percentages from KSA Ministry of Planning, Statistics Department information as reported in the Draft MOWE Regional Planning Reports (ItalConsult 2009-2010) b Percentages calculated from information as reported in the Draft MOWE Regional Planning Reports (ItalConsult 2009-2010)

Population, Growth and RQTSE • Nearly half of the Kingdom’s

population lives in the six largest cities.

• In 2035, nearly half of the population is projected to live in the six largest cities.

• Nearly 20 percent of KSA’s population is projected to live in Riyadh in 2035.

• The projected growth will increase wastewater flows but will also provide important opportunities for reuse of RQTSE to offset large future water demands.


1-6 STRATEGIC STUDY

TABLE 1-3 Year 2010 Census Population and Projections for Years 2025 and 2035

Region 2010 Census

Population a,b

Population Projectionsb,c

2025 2035

Al Baha 411,900 536,000 631,000

Al Jouf 440,000 577,000 677,000

Assir 1,913,400 2,512,000 2,957,000

Eastern Province 4,105,800 5,374,000 6,309,000

Hail 597,100 786,000 925,000

Jizan 1,365,100 1,817,000 2,137,000

Madinah 1,777,900 2,355,000 2,769,000

Makkah 6,915,000 9,067,000 10,667,000

Najran 505,700 654,000 767,000

Northern Borders 320,500 428,000 503,000

Qaseem 1,215,900 1,600,000 1,882,000

Riyadh 6,777,100 8,974,000 10,588,000

Tabouk 791,500 1,054,000 1,241,000

Totals 27,136,900 35,734,000 42,053,000 a www.geohive.com; 2010 Census Population b Numbers have been rounded c Calculated by CH2M HILL based on percentages presented in Table 1-2

TABLE 1-4 Year 2010 Census Population and Projections for Years 2025 and 2035 for Six Largest Cities in KSA

2010 Census Population b,c

Population Projections a,b

City 2025 2035

Riyadh 5,255,000 6,958,000 8,205,000

Jeddah 3,456,000 4,532,000 5,331,000

Makkah 1,675,000 2,197,000 2,584,000

Al Taif 988,000 1,295,000 1,524,000

Al Madinah 1,181,000 1,564,000 1,839,000

Dammam 904,000 1,183,000 1,388,000

Totals 13,459,000 17,729,000 20,871,000 a Numbers have been rounded b Calculated by CH2M HILL based on percentages presented in Table 1-2 c www.geohive.com; 2010 Census Population

http://www.geohive.com/


STRATEGIC STUDY 1-7

1.3 Water Supplies and Demands 1.3.1 Water Supplies in KSA Water supplies in KSA consist primarily of groundwater and desalinated water and vary by region, as shown in Figure 1-3. The water resources in each province are described in Table 1-5. In general, slightly more desalinated water is used than groundwater, but this varies greatly by region as shown in Figure 1-4.

FIGURE 1-3 Major Water Provinces in KSA Adapted from Dr. Mohammed Al-Saud (31-05-2011)


1-8 STRATEGIC STUDY

TABLE 1-5 Existing Water Sources and Supplies (Does not include all water used for agriculture or industrial purposes)

Region Groundwater Supplya,b Desalinated Water Supplya,b

% of Supply Qty (m3/day) Depth (m) % of Supply Qty (m3/day)

Al Baha 100 24,000 10 - 50 0 0

Al Jouf 100 65,000 150 - 450 0 0

Assir 23 24,000 50 - 100 77 78,000

Eastern Province 61 675,000 100 - 200 39 433,000

Hail 100 61,000 150 - 400 0 0

Jizan 98 62,000 10 - 70 2 2,000

Madinah 18 72,000 150 - 200 82 332,000

Makkah 4 48,000 15 - 50 96 1,059,000

Najran 100 9,000 50 - 100 0 0

Northern Borders 75 39,000 50 - 100 25 13,000

Qaseem 95 265,000 200 - 1400 5 15,000

Riyadh 54 993,000 1200 - 1500 46 854,000

Tabouk 86 98,000 400 - 600 14 16,000

Individual Total 2,435,000 2,802,000

Combined Total 5,237,000 m3/day a Numbers rounded b ItalConsult (2009-2010) with information from regional General Water Directorates m3/day = cubic meters per day

FIGURE 1-4 Total Existing Water Sources by Region Note: Reference: ItalConsult (2009-2010) with information from regional General Water Directorates

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000

1,600,000

1,800,000

2,000,000

Exis

ting W

ater

Sour

ces (

m3 /

day)

Desalinated Water Supply

Groundwater Supply


STRATEGIC STUDY 1-9

Table 1-5 provides information about existing water supplies, including supply sources and depth to groundwater by region. The water supply source information was provided by the General Directorate of Water in each region and was summarized in the Draft MOWE Regional Planning Reports (ItalConsult 2009-2010). Since these values are generalized for each region, it will be important to rely upon specific master planning information when developing plans for infrastructure, including capital and other types of expenditures.

In the Madinah and Makkah regions, desalinated water provides 82 percent and 96 percent, respectively, of the regions’ demands, while in the Riyadh region, more of the water supply is from groundwater than desalinated water. In most of the Kingdom, the depth to groundwater is generally 100 meters (m) to 600 m, but in the Riyadh region, the groundwater is at depths of 1,200 m to 1,500 m.

With the exception of the larger cities, it should be noted that currently many cities have only a small percentage of their service area provided with water distribution systems. The larger cities tend to have a higher percentage of distribution system coverage. According to MOWE plans, in general, coverage for water supply systems will be nearly 100 percent in cities greater than 5,000 people by the Year 2025.

1.3.2 Domestic Water Demands in KSA The domestic water demand per capita per day has been established by MOWE, based upon city size as follows:

• 250 liters (L)/capita/day for cities with populations > 85,000 (large cities) • 200L/capita/day for cities with populations < 85,000 (medium and small cities)

These values are supported by information in the Global Water Market 2011 Report and noted to be rather high by international standards (Global Water Intelligence, 2011). Figure 1-5 depicts the domestic water usage for several countries around the world for comparison.

FIGURE 1-5 Domestic Water Usage in Select Countries Source: Loay Al-Musallam, 2010

99 100 118 130 136 136 151 155 166

228

286

431

666

0

100

200

300

400

500

600

700

Dom

estic

Wat

er U

sage

(L/c

apita

/day

)


1-10 STRATEGIC STUDY

These demands (250 L/capita/day and 200 L/capita/day respectively) were applied to the 2010 census population and the projected population as presented in Section 1.2. The resulting water demands are presented in Table 1-6. Water demand is projected to increase by approximately 3,800,000 m3/day or about 56 percent between 2010 and 2035. It is important to note that the projected future water demands cannot sustainably be met using only the 5,200,000 m3/day existing water supplies as presented in Table 1-5. Meeting new demands will require very significant capital and O&M investment in new desalination plants and groundwater wells. However, the use of alternative water resources such as RQTSE can provide water to meet non-potable demands. Its use will help reduce the need for new potable water supplies and associated infrastructure, as well as reducing the energy required for treatment and conveyance. Promoting water conservation will also reduce the need for new supplies.

TABLE 1-6 Calculated Water Demands

Calculated Water Demand (m3/day)a,b

Region 2010 2025 2035

Al Baha 88,000 119,000 149,000

Al Jouf 108,000 141,000 165,000

Assir 459,000 616,000 735,000

Eastern Province 1,013,000 1,331,000 1,567,000

Hail 145,000 191,000 225,000

Jizan 318,000 443,000 530,000

Madinah 430,000 573,000 689,000

Makkah 1,718,000 2,253,000 2,655,000

Najran 122,000 158,000 185,000


Qaseem 289,000 380,000 456,000

Riyadh 1,666,000 2,225,000 2,626,000

Tabouk 187,000 249,000 298,000

Totals 6,617,000 8,783,000 10,402,000 a Numbers have been rounded b Calculated by CH2M HILL based on population projections and MOWE demands of 250L/capita/day for cities with populations > 85,000, and 200L/capita/day for cities with populations < 85,000 When considering water demands, it is important to note that in many areas, potable water service is not continuously available to customers and the water demand shortfall is managed by operating the water distribution system such that customers may receive water only periodically

Future Water Demands • Water demand is projected to increase

by 3,800,000 m3/day or about 56 percent between 2010 and 2035.

• Future demands cannot be met sustainably based solely on existing sources and treatment technologies.

• Meeting future demands will require very significant capital and O&M investments.

• RQTSE can provide water to meet non-potable demands and its use will help reduce the need for new potable water supplies.

• Use of RQTSE also reduces the energy required for treatment and conveyance.

• Promoting water conservation will also reduce the need for new supplies.


STRATEGIC STUDY 1-11

which helps ensure that all customers are provided with at least some level of service. When supplies are continuous, some areas report water demands of up to 400 L/capita/day. The MOWE water demand estimate of approximately 250 L/capita/day may not reflect the actual quantity of water that may be used if access were not restricted.

Since the values presented in Tables 1-5 and 1-6 are generalized for the regions and cities, it will be important to rely upon specific master planning information when developing plans for infrastructure and other capital expenditures.

The six largest cities in KSA comprise over 50 percent of the total 2010 water demand in the Kingdom and are projected to comprise the same percentage of the total demand in 2035. Table 1-7 summarizes information for the six largest cities. Three of the cities – Riyadh, Dammam, and Al Madinah – have 90 percent or greater coverage with water distribution system networks. Al Taif and Jeddah have greater than 75 percent coverage, while Makkah has only 56 percent coverage.

Two cities in the Makkah region, Jeddah and Makkah, rely on desalinated water for nearly 100 percent of their water supply, while desalinated water supplies 83 percent of the needs of Al Taif and Al Madinah. Water supplies for Riyadh and Dammam are approximately 50 percent groundwater and 50 percent desalinated water.

Figure 1-6 shows the locations of the five major desalination water facilities in KSA.

FIGURE 1-6 Locations of Major Desalination Facilities in KSA



TABLE 1-7 Water Supply and Demand in Largest Citiesa

City

% of City with Water

Distribution Systemc

Existing Water Supplyb Calculated Water Demand (m3/day)d

Total Supply (m3/day)

Groundwater Desalinated Water

2010 2025 2035 m3/day % m3/day %

745,000 48% 812,000 52% 1,314,000 1,740,000 2,052,000

Jeddah 80% 633,000 3,000 <1% 630,000 99% 864,000 1,133,000 1,333,000

Makkah 56% 280,000 0 0% 280,000 100% 419,000 549,000 646,000

Al Taif 78% 137,000 23,000 17% 114,000 83% 247,000 324,000 381,000

Al Madinah 98% 327,000 55,000 17% 272,000 83% 295,000 391,000 460,000

Dammam 95% 345,000 190,000 55% 155,000 45% 226,000 296,000 347,000

Totals 3,279,000 1,016,000 2,263,000 3,365,000 4,433,000 5,219,000 a Numbers have been rounded b ItalConsult (2009-2010); Numbers provided for 2009 with information from regional General Water Directorates c ItalConsult (2009-2010); Numbers provided for 2009 d Calculated by CH2M HILL based on population projections and MOWE demands of 250L/capita/day for cities with populations > 85,000

Riyadh Desalinated water is supplied to the city of Riyadh from the Al Jubail Desalination Plant located on the Arabian Gulf in the Eastern Province. Approximately 812,000 m3/day of desalinated water is transferred in three 1,500-millimeter (mm) diameter pipelines for a distance of about 450 km and amounts to approximately 52 percent of the city’s water supply. Groundwater comprises 48 percent of the city of Riyadh water supply and is supplied from nine wellfields. Seven of the wellfields are located within the city and supply 250,000 m3/day. However, the groundwater table in Riyadh has declined significantly due to an increase in withdrawals, causing the piezometric level to fall from 45 m in 1956 to 170 m below ground in 1980, and to more than 250 m in 2008. Two wellfields, located approximately 70 km and 200 km outside the city, provide a total of 495,000 m3/day of groundwater to the city. In Riyadh, the water supply and distribution systems are the responsibility of the NWC.

Jeddah The city of Jeddah’s water supply is almost all desalinated water produced by two plants on the Red Sea: the Jeddah Plant, which provides about 400,000 m3/day, and the Shoaibah Plant, which provides approximately 230,000 m3/day. The combined total was 630,000 m3/day in 2009. A small additional amount of water (3,000 m3/day) was provided by groundwater. There are plans to increase the capacity of both the Jeddah Plant and the Shoaibah Plant to meet future water demands. The water supply and distribution systems are the responsibility of the NWC.

Makkah and Al Taif The city of Makkah’s water supply consists entirely of desalinated water produced by the Shoaibah Plant located near Jeddah; approximately 280,000 m3/day was provided to Makkah in 2009. In Makkah, the water supply and distribution systems are the responsibility of the NWC.



The desalinated water supply for the city of Al Taif is transferred from the city of Makkah. It is supplied by the Shoaibah Plant located near Jeddah and comprises 83 percent of the water supply of Al Taif. The remaining 17 percent of the city’s supply is groundwater from wellfields located several hundred km from the city. The water supply and distribution systems are the responsibility of the NWC.

Al Madinah The city of Al Madinah’s water supply is primarily desalinated water (272,000 m3/day) produced by the Yanbu Desalination Plant, which has been in operation since 1981. It is located on the Red Sea and water is transferred approximately 250 km to Al Madinah through two transmission lines. Groundwater (55,000 m3/day) is provided from wellfields located south of Al Madinah, which include approximately 90 production wells. In Al Madinah, the water supply and distribution system will be under the responsibility of the NWC in the near future.

Dammam The water supply for Dammam is approximately 55 percent groundwater and 45 percent desalinated water. The Al Aziziyah (Khobar) Desalination Plant on the Arabian Gulf supplies 155,000 m3/day of water to Dammam. Due to heavy groundwater pumping to provide an additional 190,000 m3/day of water, most of the wells show a significant drop in the water table, especially in the Dammam area. In Dammam, the water supply and distribution system will be under the responsibility of the NWC in the near future.

1.4 Wastewater Flows WWTPs are located in nearly every region and primarily serve the large and medium cities. Many more plants throughout the Kingdom are under construction or planned. It should be noted that currently many cities have only a small percentage of their service area provided with sewage collection. The larger cities tend to have a higher percentage of sewage system coverage. According to MOWE plans, the percent coverage for sewage collection systems will be nearly 100 percent in cities greater than 5,000 people by the Year 2025 (ItalConsult, 2009-2010).

Table 1-8 summarizes the 2010 and projected wastewater flows for Years 2025 and 2035.

Future wastewater flows were calculated from the water projections based on the following assumptions used in the Draft MOWE Regional Planning Reports (ItalConsult 2009-2010):

• The amount of return flow to the sanitary sewage system is 80 percent. • Current leakage in the collection system is 20 percent. • Leakage will decrease to 15 percent by the Year 2025 and to 10 percent by the Year

2035.

Because wastewater flows are calculated from the water demands (which are calculated from the population projections), the flows are not directly related to the percentage of cities that are served with sanitary sewage services.

Based on the 2010 census, it will be necessary for MOWE to review its plans for future WWTP capacities to determine if additional capacity may be needed to accommodate growth patterns that may have changed since previous projections.

Future Wastewater Flows • Wastewater flows are projected to

increase by approximately 3,200,000 m3/day or about 76 percent between 2010 and 2035.

• Increased wastewater flows will provide important opportunities for reuse of RQTSE to offset large future water demands.



TABLE 1-8 Projected Wastewater Flows and WWTP Status in Each Regiona

WWTPs and Capacities (m3/day)c

Calculated Wastewater Flows (m3/day)b Existing Under Constructiond Planned Total Planned

Future Capacitye Region 2010 2025 2035 No. Capacity No. Capacity No. Capacity

Al Baha 56,000 81,000 107,000 0 0 1 16,200 6 72,600 88,800

Al Jouf 69,000 96,000 119,000 2 38,000 2 57,500 1 22,000 117,500

Assir 294,000 419,000 529,000 4 82,500 7 172,500 0 0 255,000

Eastern Province 648,000 905,000 1,128,000 13 527,300 6 251,000 1 400,000 1,178,300

Hail 93,000 130,000 162,000 1 19,200 2 87,600 1 55,800 162,600

Jizan 203,000 301,000 381,000 1 20,000 0 0 22 112,000 132,000

Madinah 275,000 390,000 496,000 4 351,000 5 34,000 0 0 385,000

Makkah 1,100,000 1,532,000 1,911,000 15 888,000 6 902,000 1 113,000 1,903,000

Najran 78,000 107,000 133,000 0 0 1 60,000 5 170,000 230,000

Northern Borders 47,000 71,000 88,000 2 24,000 1 24,000 1 25,000 73,000

Qaseem 185,000 258,000 328,000 5 131,500 3 125,000 0 0 256,600

Riyadh 1,066,000 1,513,000 1,890,000 10 993,500 7 443,500 2 530,000 1,967,000

Tabouk 120,000 169,000 214,000 1 60,000 1 15,000 0 0 75,000

Totals 4,234,000 5,972,000 7,486,000 3,135,000 2,188,300 1,500,400 6,823,700 a Numbers have been rounded b Calculated by CH2M HILL based on population projections, calculated water demands and the amount of return flow to the sanitary sewage system. The amount of return flow, per MOWE, is 80 percent; in 2010, leakage in the collection system was 20 percent; leakage will decrease to 15 percent by the Year 2025 and to 10 percent by the Year 2035 c ItalConsult (2009-2010) d Under Construction” includes both new plants and expansions to existing plants e No timeframe was provided for the total planned future capacity values included in the Draft MOWE Regional Planning Reports (ItalConsult, 2009-2010)



Most of the wastewater is generated in the six largest cities and receives tertiary or secondary treatment, as shown in Table 1-9. More details about wastewater and reuse in these cities are provided in Section 1.5.

As shown in Table 1-8, three plants are nearing or have exceeded their design capacity. The Airport 1 WWTP project has recently been completed in Jeddah to significantly increase capacity. Projects are currently under construction in Riyadh, Jeddah, Makkah, and Dammam to provide additional capacity. Additional projects are planned for Riyadh, Jeddah, Al Taif, and Al Madinah.

The values presented in Tables 1-8 and 1-9 are generalized for the regions and cities, and it will be important to rely upon specific master planning information when developing plans for infrastructure and other capital expenditures.

TABLE 1-9 Wastewater Flows in Largest Cities

City

Number of Major

WWTPs

Percent of City

Seweredc,d Treatment Levelc,e

Total Existing

Treatment Capacity

(m3/day)b,c

Calculated Wastewater Flows (m3/day)a,b

2010 2025 2035

Riyadh 6 55% 5 Tertiary 1 no information

832,000 841,000 1,183,000 1,478,000

Jeddahf 11 50% 10 Secondary 1 Tertiary

621,000 553,000 770,000 960,000

Makkah 3 45% 1 Primary 2 Secondary

195,000 268,000 373,000 465,000

Al Taif 1 50% Secondary 67,000 158,000 220,000 274,000

Al Madinah

1 68% Tertiary 240,000 189,000 266,000 331,000

Dammam 1 78% Secondary 209,000 145,000 201,000 250,000

Totals 2,164,000 2,154,000 3,013,000 3,758,000 a Calculated by CH2M HILL based on population projections, calculated water demands and the amount of return flow to the sanitary sewage system. The amount of return flow, per MOWE, is 80 percent; in 2010, leakage in the collection system is 20 percent; leakage will decrease to 15 percent by the Year 2025 and to 10 percent by the Year 2035 b Numbers have been rounded c ItalConsult (2009-2010) d Percentages provided for 2008-2009 e Primary treatment removes a portion of suspended solids and organic material. Secondary treatment removes biodegradable organic matter (in solution or suspension) and suspended solids. Disinfection is typically included in the definition of conventional secondary treatment. Tertiary treatment removes residual suspended solids (after secondary treatment) using granular media, surface or membrane filtration. Disinfection is typically part of tertiary treatment. Nutrient removal is often included in tertiary treatment. f Includes Airport 1 WWTP

1.5 Water Reuse The term “reuse disposal water” is sometimes used interchangeably with the terms “wastewater recycling” and “wastewater reclamation.” Because the public often does not generally understand the quality difference between treated and untreated wastewater, many communities have shortened the term to “water reuse,” which creates a more positive image. The U.S. Environmental Protection Agency (USEPA) defines wastewater reuse as



“using wastewater or treated wastewater from one application for another application.” The deliberate use of wastewater or treated wastewater must be in compliance with applicable rules for a beneficial purpose, such as landscape irrigation, agricultural irrigation, aesthetic uses, groundwater recharge, and industrial uses.

KSA is committed to beneficially using all RQTSE in the future. This section describes existing RQTSE uses as well as projections that have been made for future RQTSE uses in KSA. This section also includes a more detailed discussion of the current and future RQTSE situation in the Kingdom’s six largest cities.

1.5.1 Current and Projected RQTSE Use in KSA A number of WWTPs in several regions of KSA are producing RQTSE that is being reused. Existing and projected RQTSE production by region through 2035 is shown in Figure 1-7. Use of RQTSE is projected to be greatest in the Riyadh, Makkah, Al Madinah, and Eastern Province regions, which are home to the six largest cities in KSA.

FIGURE 1-7 Existing and Projected Future RQTSE Production by Region in 2010, 2025, and 2035

Reference: ItalConsult (2009-2010)

Figure 1-8 shows the percentage of RQTSE use by type projected for the year 2025; it is clear that agricultural RQTSE use is the largest percentage in every region of KSA. Figures 1-9 and 1-10 also demonstrate that the greatest use of RQTSE now and anticipated in the future is for agricultural purposes. Landscaping in urban areas and around the WWTPs is also a significant use. The most common use of RQTSE by industries is for processing and cooling for power stations. By comparison, only small quantities are used for recreational purposes and for aquifer recharge. Note that Figures 1-9 and 1-10 are based on the same data; the data are just displayed differently in the two figures. Table 1-10 presents more detail about each type of RQTSE use.

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000

1,600,000

1,800,000

2,000,000

RQST

E Pro

duct

ion

2025-2035

2010-2025

2010

Current RQTSE Uses in KSA • Agricultural irrigation. • Landscaping in urban areas. • Landscaping on WWTP sites. • Industrial use for processing and

cooling. • Recreation. • Aquifer recharge.



FIGURE 1-8 Proposed RQTSE Use Amounts by Region by Type in Year 2025 Shown as Percent of Total


FIGURE 1-9 Existing and Projected Future RQTSE Use by Type in KSA

Reference: ItalConsult (2009-2010

67%

40%

63%

81%

50%

67%62%

43%

60%

70%

60%

70% 68%

29%

30%

31%

19%

30%

30%

23%

45%

30%

30%

21%9%

26%

4%

20%

7%0%

20%

3%

16%11%

0%

0%

16% 17%

6%0%

10%

0% 0% 0% 0% 0% 0%

10%

0%0% 4%

0%0% 0% 0% 0% 0% 0% 0% 0% 0% 0%3%

0% 0%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%RQ

STE U

se b

y Ty

pe

Aquifer Recharge

Recreation

Industry

Landscaping

Agriculture

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

2010 2015 2020 2025 2030 2035

RQST

E U

se b

y Ty

pe (m

3 /da

y)

Total

Agriculture

Landscaping

Industry

Recreation

Aquifer Recharge



FIGURE 1-10 Total Existing and Projected Future RQTSE Use by Type in KSA


TABLE 1-10 Reuse Applications by Primary and Sub-Category Primary Categories Sub-Categories/Examples

Agriculture • Tertiary treatment is required to meet unrestricted agricultural irrigation, which includes salad crops and vegetables eaten raw, and restricted, other crops; winter and summer cultivation.

• Crop examples include: cereal, vegetables, melons, watermelon, fruits, citrus, grapes, dates, fodder, alfalfa.

Landscaping • Secondary treated and disinfected water suitable for most landscaping in areas without direct human contact. Tertiary treatment is required for use in public parks or other areas where direct human contact is likely.

• Applications include: green areas in the cities, such as planting trees along roads, turf and grass areas, and public parks.

Industrial • Secondary treated and disinfected water in some cases (cooling towers, irrigating nurseries and plants surrounding industrial areas).

• Very high quality water for some uses (high pressure boiler feed); even higher quality may be needed for other uses.

Recreation • Not regulated in KSA yet. However, in most cases, tertiary treatment is required for unrestricted recreation.

• In Al Jouf Region: small lakes or parks • In Riyadh Region: development of Wadi Hanifa, maintenance of Al Hayer Lakes

Aquifer Recharge • Not regulated in KSA yet. The requirements vary depending upon recharge type (direct recharge or sub-surface spreading, etc.).

• Used to reduce the scale of drop in water table. • In Qaseem Region: allocated amounts flow through a wadi and mix with stored water

from stormwater for aquifer recharge.

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

2010 2012 2015 2020 2025 2030 2035

RQST

E Us

e by

Typ

e (1

,000

m3 /

day)

Aquifer Recharge

Agriculture

Recreation

Landscaping

Industry



In 2025, approximately 4,700,000 m3/day of RQTSE is anticipated to be used (ItalConsult, 2009-2010.) However, other sources predict that reuse demands will occur more quickly. For example, according to the NWC, RQTSE demand is expected to be approximately 5,200,000 m3/day in 2020 (Loay Al-Musallam, 2010).

1.5.2 Wastewater and Reuse in the City of Riyadh Riyadh is the national capital and largest city in KSA. The 2010 census population was 5,255,000, and only about 55 percent of the city has sanitary sewer service. Currently, there are five major wastewater systems that collect and treat municipal wastewater in the city and one system that collects and treats industrial wastewater (Figure 1-11). However, there are many other small private WWTPs serving other entities such as airports, military camps, and hospitals. According to the General Water Directorate’s statistics for Riyadh, there are about 62 operating WWTPs in the city.

FIGURE 1-11 City of Riyadh Major Wastewater Treatment Facilities The city of Riyadh has been very successful in reusing nearly 50% of its RQTSE, primarily in these four categories:

• Discharged into wadis or pumped to farms for agricultural uses; an example is RQTSE reuse from the Manfouha plants (East, North, and South) for the Wadi Hanifa project.

• Used for landscaping activities; an example is the RQTSE reuse from the Al Jazira plant, which is used by Riyadh Municipality.

• Used by industries; examples include reuse from the Manfouha East Plant and the 2nd Industrial City Plant.

• Used for natural recharge; an example is the RQTSE from the Al Heet Treatment Plant, which is discharged through a canal 40 km to the south in the Al Kharj area, where it is stored in a pond and then infiltrates through the sandy soil to groundwater.

A large amount of RQTSE from the Manfouha WWTPs is being discharged to Wadi Hanifa (Figure 1-12), which is located in Riyadh and extends beyond the city into the surrounding rural

Riyadh Wastewater Facts • 2010 Population: 5,255,000 • Major WWTPs: 6 • Percent of City Sewered: 55% • 2010 Flows at Major WWTPs:

671,700 m3/day • Existing Major WWTP Capacity:

832,000 m3/day • Amount Reused: 327,200 m3/day • Percent Reused: 49%



areas. The vision for Wadi Hanifa is to use RQTSE to transform an urbanized wadi into a ribbon of naturalized parkland for recreation that extends through the city and to promote the area as a green, safe, and healthy environment that connects residential development, farming, recreation, cultural activities, and tourism.

FIGURE 1-12 Top: Aerial View of the Wadi Hanifa, 2009 Bottom: A series of natural stone weirs were built to introduce oxygen into the water

Reference: Wadi Hanifa Wetlands, 2010 On-Site Report

The NWC is responsible for wastewater collection and treatment services in Riyadh. Table 1-11 provides a summary of information about each of the six major WWTPs in Riyadh. In addition, the many small private plants treat a total of approximately 100,000 m3/day.

Only approximately 23,000 m3/day of RQTSE is used by industries of the 327,200 m3/day of RQTSE produced. The use of reclaimed water for cooling by industries or commercial enterprises, and possibly by public buildings, could increase due to the high cost of using desalinated water.

In the future, with expected growth and increased sanitary sewer service, there will be a significant additional quantity of treated wastewater that could be treated to RQTSE standards and then reused. Plans for increased future reuse in Riyadh are summarized in Table 1-12. The priority is expected to change from agricultural to industrial, with an increased proportion of RQTSE used for industrial/cooling and proportionally less being used for agriculture.



TABLE 1-11 Summary of Major Existing WWTPs and Reuse Status in Riyadha

Major Existing WWTPsb

Wastewater Dischargesc Wastewater Reusec

Facility Name Treatment Level

Design Capacity (m3/day)

Treated Amount (m3/day)

Percent Discharged

(m3/day)

Discharged Amount (m3/day)

Discharge Locationd

Percent Reused (m3/day)

Reused Amount (m3/day) Reuse Type Reuse Location

Manfouha Ee Tertiary - Oxidation Ditch

200,000 173,500 61% 344,500 NI 39% 223,000 Industry /

Agriculture

13,000 m3/day to ARAMCO; remainder to agricultural use in Wadi Hanifa and Wadi Al Batin

Manfouha Ne Tertiary - Aerated Basins

200,000 151,000

Manfouha Se Tertiary - Trickling Filter

200,000 243,000

Al Jazira Tertiary - Activated Sludge

4,000 4,200 0% 0 NI 100% 4,200 Landscaping Landscaping by Riyadh Municipality

Al Heet (Al Kharj Road)

Tertiary - Activated Sludge - extended aeration

200,000 75,000 0% 0 NI 100% 75,000 Natural Recharge

Quarry Storage pond in Al Kharj area

2nd Industrial City

NI 28,000 25,000 0% 0 NI 100% 25,000 Industry /

Landscaping

10,000 m3/day to Al Ebekan Paper Factory; remainder to landscaping

Totals 832,000 671,700 344,500 327,200 a ItalConsult (2009-2010) b Major WWTPs only; there are an additional 62 small private plants that treat approximately 100,000 m3/day c Numbers provided for 2009 d NI = No information available e Treated Amount information for the Manfouha East, North, and South WWTPs is presented separately although the facility is essentially one treatment plant



TABLE 1-12 Future Reuse Amounts in City of Riyadha

Reuse Type

2015 2025 2035

Percent Amount (m3/day) Percent

Amount (m3/day) Percent

Amount (m3/day)

Industrial/Cooling 10 65,000 20 215,000 30 400,000

Agricultural Reuse 80 520,000 70 760,000 50 800,000

Recreation 5 35,000 5 55,000 10 135,000

Landscaping 5 35,000 5 55,000 10 135,000

Totals 100 655,000 100 1,085,000 100 1,470,000 a ItalConsult (2009-2010)

Other projections of RQTSE reuse in the City of Riyadh have been developed by NWC as shown in Figure 1-13. These projections are significantly higher than those presented above and provide more details about future sector use.

FIGURE 1-13 Projections of Future Reuse by Sector and Estimates of Available RQTSE in the City of Riyadh

Reference: Nasser Al-aamry, 2010-2011

1.5.3 Wastewater and Reuse in the City of Jeddah Jeddah is located in the Makkah Region and is the second largest city in KSA. The 2010 census population was 3,456,000, and only about 50 percent of the city has sanitary sewer service. Wastewater is treated in 12 major WWTPs with a total capacity of approximately 681,000 m3/day. The estimated 2010 wastewater flows were 370,400 m3/day. Most treated wastewater is discharged to the Red Sea, but approximately 15 to 20 percent was reused for landscaping in the 2008-2009 timeframe.

Table 1-13 provides information about each of the 12 existing WWTPs and the status of wastewater reuse from each plant. Figure 1-14 shows the locations of the major plants. The Briman WWTP is east of the area shown on this map near the Jeddah Sewage Lake.



TABLE 1-13 Summary of Existing WWTPs and Reuse Status in Jeddaha

Wastewater Discharges Wastewater Reuse

Facility Name

Treatment Level

Design Capacity (m3/day)

Treated Amount (m3/day)

Percent Discharged

(m3/day)

Discharged Amount (m3/day)

Discharge Location

Percent Reused (m3/day)

Reused Amount (m3/day)

Reuse Type and Location

Al Balad Secondary 40,000 34,500 42% 14,500 Red Sea 58% 20,000 Landscape

Al Rowais Secondary 32,000 19,700 24% 4,700 Red Sea 76% 15,000 Landscape

Bani Malik Secondary 8,000 11,100 37% 4,100 Red Sea 63% 7,000 Landscape

Al Eskan Old Secondary 8,000 2,400 16% 400 Red Sea 84% 2,000 Landscape

Al Eskan New Secondary 8,000 6,300 79% 5,000 Red Sea 21% 1,300 Landscape

Al Jamea Secondary 11,000 3,400 41% 1,400 Red Sea 59% 2,000 Landscape

Airport Tertiary 24,000 24,000 100% 24,000 Red Sea 0% 0 No Reuse

Airport 1 Tertiary 250,000 60,000 100% 60,000 Red Sea 0% 0 No Reuse

Al Khumra 1 Secondary 40,000 35,000 100% 35,000 Red Sea 0% 0 No Reuse

Al Khumra 2 Secondary 60,000 42,000 100% 42,000 Red Sea - Unknown Industry

Al Khumra 3 Secondary 140,000 108,000 100% 108,000 Red Sea 0% 0 No Reuse

Briman WWTP Tertiary 60,000 24,000 0% 0 Red Sea 100% 24,000 Landscape

Totals 681,000 370,400 299,100 73,300 a ItalConsult (2009-2010) b Personal communication with NWC Jeddah City Business Unit (JCBU), 2011



A significant percentage of RQTSE generated could be reused. Plans for future reuse of RQTSE include using approximately: • 30 percent for agriculture • 50 percent for landscaping • 20 percent for industrial reuse

The approximately 50 percent of the city that does not have sanitary sewer uses septic tanks, which are emptied by tanker trucks. The trucks have disposed of the septage at the Al Misk Lake (now referred to as the Jeddah Sewage Lake) located approximately 18 km east of the city. In early 2010, emptying of trucks directly to the lake was halted and all trucks emptied directly to the tertiary WWTP located at the lake. This WWTP has a capacity of 60,000 m3/day. Approximately 20,000 m3/day of the RQTSE is used for irrigation of planted forests in the vicinity of the lake and an additional approximately 5,000 m3/day is hauled by tanker for use for irrigation around the municipality and region. The remaining RQTSE is discharged to a pipeline that leads to a drainage canal that goes to the sea (CH2M Olayan, 2011). Also in 2010 and early 2011, a new Airport 1 WWTP was completed and it has a treatment capacity of 250,000 m3/day.

As of April 2011, the Airport plant was treating approximately 60,000 m3/day of wastewater entirely delivered by tankers since the sewage network is not yet connected to the facility (personal communication with NWC JCBU, 2011).

The NWC is responsible for wastewater collection and treatment services in Jeddah. It is planning to privatize one industrial WWTP that is under construction and is designed to treat 50,000 m3/day of sanitary and industrial wastewater.

The NWC will manage the sale of the RQTSE for industrial purposes in the industrial zones located south of Jeddah and is responsible for constructing the reuse distribution system to that area.

1.5.4 Wastewater and Reuse in the City of Makkah Makkah is located in the Makkah Region and is the third largest city in KSA. The 2010 census population was 1,675,000, and only approximately 45 percent of the city has sanitary sewer service. Makkah is unique in that the population in the city increases by 300 percent during the annual Hajj period according to the Central Department of Statistics. One WWTP, the Aziziah Plant, is used only during the Hajj period and provides only primary level of treatment. Most of the year, wastewater is treated in two WWTPs with secondary levels of treatment and a total combined capacity of approximately 70,000 m3/day.

FIGURE 1-14 City of Jeddah Major Wastewater Treatment Facilities

Jeddah Wastewater Facts • 2010 Population: 3,456,000 • Major WWTPs: 11 • Percent of City Sewered: 50% • 2010 WW Flows: 346,400

m3/day • Existing WWTP Capacity:

621,000 m3/day • Amount of WW Reused:

47,300 m3/day • Percent of WW Reused: 14%



The estimated 2010 wastewater flows were 175,000 m3/day, including seasonal flows from the Aziziah Plant. The treated volume is discharged to a wadi and none was reportedly reused in the 2008-2009 timeframe. The locations of the plants are shown in Figure 1-15. Table 1-14 provides information about the three existing WWTPs.

TABLE 1-14 Summary of Existing WWTPs and Reuse Status in Makkaha

Akashiya No 1 Akashiya No 2 Aziziahb

Treatment Level Secondary Secondary Primary

Design Capacity (m3/day) 30,000 40,000 125,000

Treated Amount (m3/day) 10,000 40,000 125,000

Percent Discharged (m3/day) 100% 100% 100%

Discharged Amount (m3/day) 10,000 40,000 125,000

Discharge Location Wadi Wadi Wadi

Percent Reused (m3/day) 0% 0% 0%

Reused Amount (m3/day) 0 0 0

Reuse Type and Location No Reuse No Reuse No Reuse a ItalConsult (2009-2010) b Operates only during Hajj period

Treated wastewater from the two plants providing secondary treatment, Akashiya No. 1 and Akashiya No. 2, could be used as RQTSE assuming the effluent meets the water quality requirements. Plans for future reuse of RQTSE include using approximately: • 50 percent for agriculture • 50 percent for landscaping, especially for trees along streets and at pilgrim sites

The NWC is responsible for wastewater collection and treatment services in Makkah.

1.5.5 Wastewater and Reuse in the City of Al Taif One WWTP serves Al Taif, which is located in the Makkah Region. The 2010 census population of Al Taif was 988,000, and only approximately 50 percent of the city has sanitary sewer service. The estimated 2010 wastewater flows were 70,000 m3/day.

Approximately 90 percent of the TSE from WWTPs is reused for agricultural irrigation and the remaining 10 percent is discharged to a wadi.

Table 1-15 provides information about the existing WWTP. Most of the RQTSE is reused. In the future, with expected growth and increased sanitary sewer service, there will be a significant additional quantity of RQTSE that could be reused. Plans for future reuse of RQTSE include using approximately: • 90 percent for agriculture • 10 percent for landscaping

FIGURE 1-15 City of Makkah Major Wastewater Treatment Facilities



The NWC is responsible for wastewater collection and treatment services in Al Taif.

1.5.6 Wastewater and Reuse in the City of Al Madinah

One WWTP serves the city of Al Madinah, which is the fourth largest city in KSA. The 2010 census population of Al Madinah was 1,181,000, and approximately 68 percent of the city has sanitary sewer service. The estimated 2010 wastewater flows are 238,000 m3/day. Almost 100 percent of the TSE is reused for agricultural irrigation and landscaping by the municipality.

Table 1-16 provides information about the existing WWTP. The location of the plant is shown in Figure 1-16.

Most of the existing TSE is reused. In the future, with expected growth and increased sanitary sewer service, there will be a significant additional quantity of TSE that could be reused. Plans for future reuse of RQTSE include using approximately: • 80 percent for agriculture • 20 percent for landscaping

The NWC will be responsible for wastewater collection and treatment services in Al Madinah in the near future. There are plans for the NWC to privatize the 240,000-m3/day plant, as well as a new 200,000-m3/day plant to be constructed.

TABLE 1-15 Summary of Existing WWTP and Reuse Status in Al Taif Facility Name Al Taif (Al Hawiyyah)

Treatment Level Secondary

Design Capacity (m3/day) 67,000

Treated Amount (m3/day) 47,000

Percent Discharged (m3/day) 10%

Discharged Amount (m3/day) 4,700

Discharge Location Wadi

Percent Reused (m3/day) 90%

Reused Amount (m3/day) 42,300

Reuse Type Agriculture aItalConsult (2009-2010)

TABLE 1-16 Summary of WWTP and Reuse Status in Al Madinaha

Facility Name Madinah

Treatment Level Tertiary



Percent Discharged (m3/day) < 1%


Discharge Location -



Reuse Type and Location Irrigation of cultivated areas around the plant and landscaping activities by Al Madinah municipality

a ItalConsult (2009-2010) FIGURE 1-16 City of Al Madinah Major Wastewater Treatment Facility



1.5.7 Wastewater and Reuse in the City of Dammam The Dammam WWTP serves only Dammam city. It is located within the city and receives collected wastewater from the city through four large sewers. It also receives wastewater from Dammam 1st Industrial City.

The 2010 population of Dammam was 904,000. Approximately 78 percent of the city has sanitary sewer service. The estimated 2010 wastewater flows were 240,000 m3/day. Table 1-17 provides information about the existing WWTP.

Most RQTSE is discharged to the Arabian Gulf and very little is reused. The small quantity that is reused is for landscaping within the plant. In the future, with expected growth and increased sanitary sewer service, a significant quantity of TSE could be reused. Plans for future reuse of RQTSE include using approximately: • 70 percent for agriculture • 30 percent for landscaping

The NWC will be responsible for wastewater collection and treatment services in Dammam.

1.6 Wastewater Treatment Processes Used to Produce RQTSE The most commonly used secondary treatment technology in KSA is conventional activated sludge (CAS) systems, while filtration and disinfection provided by media filtration and chlorination are the most common tertiary treatment technologies used to produce RQTSE.

A few advanced wastewater treatment facilities utilizing reverse osmosis (RO) have been identified in KSA.

Activated sludge systems incorporate biological treatment processes that involve the conversion of organic matter and/or other constituents in wastewater to cell tissue and final products (i.e., carbon dioxide, water) by a large mass of microorganisms maintained in suspension by mixing and aeration, followed with clarification of treated water by means of sedimentation. The microorganisms form flocculent particles that are separated from the process effluent using secondary clarifiers and subsequently returned to the front end of the aeration basin (referred to as return activated sludge, or RAS) or wasted (referred to as waste activated sludge, or WAS).

Activated sludge facilities configured to remove biochemical oxygen demand (BOD) and total suspended solids (TSS) and provide ammonia oxidation are commonly referred to as CAS systems. Activated sludge systems configured to remove BOD, TSS, and nitrogen simultaneously are referred to as biological nutrient removal (BNR) CAS processes. BNR

TABLE 1-17 Summary of Existing WWTP and Reuse Status in Dammama Facility Name Dammam

Treatment Level Secondary - Activated Sludge



Percent Discharged (m3/day) 97%


Discharge Location Arabian Gulf



Reuse Type and Location Landscape inside the plant property

a ItalConsult (2009-2010)

Existing Treatment Processes used in KSA • Activated sludge facilities appear to be the

most common secondary treatment technology in KSA.

• Tertiary facilities are operating in some of the larger cities, particularly in Riyadh.



CAS processes include anoxic/aerobic stages and nitrate recycle from aerobic zones to anoxic zones to achieve the combined removal of organics, nitrogen, and solids. Treated wastewater from BNR CAS systems needs to be filtered and disinfected to produce RQTSE. This process is depicted in Figure 1-17.

FIGURE 1-17 Process Schematic of BNR CAS and Integrated Filtration and Disinfection Facilities to Produce RQTSE

In addition to BNR CAS, other secondary treatment technologies used to meet unrestricted reuse requirements (described in Section 1.9) for BOD, TSS, and nitrogen include orbal ditches, biologically active filters, Biolac, sequencing batch reactors (SBRs), and membrane bioreactors (MBRs). MBRs combine activated sludge biological treatment with an integrated membrane system to provide enhanced organics stabilization and suspended solids removal. MBR uses a low-pressure membrane system (i.e., microfiltration [MF] or ultrafiltration [UF]) and eliminates the need for secondary clarifiers and tertiary filtration facilities for solids-liquid separation. MBR-treated wastewater must be disinfected (using chlorination, ultraviolet [UV] disinfection, or ozonation) to meet unrestricted reuse requirements. Figure 1-18 presents the process flow schematic for a typical MBR system.

FIGURE 1-18 Process Schematic of BNR MBR and Integrated Disinfection Facilities to Produce RQTSE

With the exception of MBRs, all technologies require the incorporation of filtration (i.e., depth media filtration, surface media filtration, or membrane-based filtration) and disinfection facilities to meet unrestricted reuse requirements.

1.7 Treatment and Use of Sewage Sludge (Biosolids) Sludge use or disposal is an important element of any sewage and sludge treatment strategy because it determines the degree and sometimes the form of treatment required. The primary reasons are its value as a fertilizer and as a soil conditioner for moisture retention. Biosolids contain nutrients that are necessary for crop growth. Its organic constituents can improve certain soils by increasing their moisture retention properties, which is of particular value for sandy soils such as those in many parts of KSA. The municipal sewage sludge can contain macronutrients (i.e., nitrogen and phosphorus) and several micronutrients (i.e.,



potassium, calcium, iron, etc.). Biosolids can also be a source of energy, either by methane generated by treated or as a source of fuel for energy recovery systems.

Information on sludge volumes produced by the major WWTPs in KSA has been obtained for the Jeddah area and for the Riyadh area. The NWC JCBU reports that approximately 655 m3/day of dried (approximately 20 percent) sludge is produced at nine Jeddah area WWTPs in 2010 from a design flow of 411,000 m3/day (NWC JCBU, 2011). The sludge is dewatered using either belt presses of centrifuges. All of the sludge generated is being disposed of at a sludge landfill. A recommended sludge management plan has been developed by the JCBU that includes the following components:

• Landfill – Improve management of the landfill sites and investigate expansion/new area as a contingency plan.

• Plant Operations – Implement increased sampling and analysis of sludges, review facilities operations, improve equipment to monitor flow and sludge volumes, compile data for routine reports.

• Extra Laboratory Analyses – Investigate laboratory operations to improve data quality so that results conform to USEPA and Presidency of Meteorology and Environment (PME) requirements.

• Solar Drying Pilot Project – Investigate the development of a pilot project for solar drying of sludge.

• Thermal Drying – Investigate alternative approaches to thermal drying and potential retrofitting of the thermal dryer at the Airport 1 WWTP.

• Ecocycling – Determine feasibility of this approach with high quality analytical data.

• Use of Thermally Dried Sludge as a Fuel Supplement – Contact cement factories and conduct feasibility studies to assess suitability as a fuel source.

• Use of Dried Sludge as a Fertilizer – Obtain analytical data for both solar and thermally dried sludge to assess value as a fertilizer. Consult with Jeddah Development and Urban Regeneration Company and others for potential use.

Information on sludge volumes and treatment was also obtained from NWC Riyadh City Business Unit (RCBU). WWTP facilities in Riyadh currently generate between 800 and 900 m3/day of dried (approximately 20 percent) sludge. This material is dewatered using either belt presses or centrifuges. Approximately 200 m3/day is currently provided to a compost facility for production of fertilizer. The remaining sludge is landfilled. NWC RCBU also indicated that they are working on a contract so that all of the sludge will be composted in the near future (personal communication with NWC RCBU, 2011).

Requirements for the use of biosolids in agriculture are presented in Section 1.9.

1.8 Industrial Water, Wastewater, and Reuse Practices The main industries in Saudi Arabia are crude oil production, petroleum refining, basic petrochemicals, ammonia, industrial gases, sodium hydroxide (caustic soda), cement, fertilizer, plastics, metals, commercial ship repair, commercial aircraft repair and construction. The industrial water requirement in the country is estimated to be 710,000,000 m3/year (Global Water Intelligence, 2011).

This section provides a brief overview of the industrial water, wastewater and reuse practices in several of the larger cities in KSA. Some industries have performed economic analyses to evaluate the feasibility of implementing water reuse to reduce water



consumption and offset water purchase costs. These studies indicate that reuse is feasible and will be a strong interest of industries in the near future, as described in Chapter 4.

1.8.1 Riyadh The use of RQTSE by industries in Riyadh, both currently and projected in the future is presented in Table 1-18.

TABLE 1-18 Current and Projected Future Use of RQTSE in Riyadha

Industry Current Use (m3/day) Future Use (m3/day)

ARAMCO 13,000 from Manfouha WWTPs 60,000

Al Ebekan Paper Factory 10,000 from 2nd Industrial City WWTP 15,000

Al Odwan Chemical Industries 45,000

ITTC 5,500

AL Olayah ST Projects 7,500

King Saud University 15,000

King Abdullah Financial City 22,000

MoWAH 50,000

SEC-PP-11 Agreement Signed 10,000

SEC Riyadh Plant MoU signed 30,000

Industrial Gate City Under Discussion 10,000

First Industrial City 1,500

Second Industrial City 45,000

Sudair Industrial City 55,000

Total 23,000 371,500 a ItalConsult (2009-2010)

1.8.2 Jeddah and the Makkah Region Two private desalination plants serving industrial customers in Jeddah are owned by Kindasa Water Services; the total capacity of both plants is 29,500 m3/day (Global Water Intelligence, 2011). The current industrial water demand in the Makkah region is around 148,000,000 m3/year. This amount is expected to increase to 163,000,000 m3/year in 2014. The use of treated wastewater in industry is being considered from the Al Khumra treatment plants located in the southern part of Jeddah.

1.8.3 Dammam In Dammam, there are two industrial cities with the primary factories consisting of metal finishing, chemical and pulp/paper. Dammam 1st Industrial City contains 120 factories. Dammam 2nd Industrial City contains 240 factories and plans to expand to 500 factories. Groundwater is the primary water supply and the industries avoid using RQTSE since groundwater is available. Approximately 60,000 m3/day of wastewater from Dammam 2nd Industrial City is discharged to a wadi without reuse.

The Saudi Industrial Property Authority, Modon, oversees the Dammam 1st and 2nd Industrial cities and its main objective is to support industry by providing new industrial lands



and improving services. Modon is discussing with HIDA the possible transfer of treated wastewater from Dammam 2nd Industrial City to the HIDA reuse project.

1.8.4 Al Jubail and Yanbu Marafiq is a private enterprise whose core business is the operation, maintenance, management, expansion and construction of seawater cooling systems, desalinated and treated water systems, and sanitary and industrial wastewater systems to provide essential utility services to industrial, commercial and residential customers in the industrial cities of Jubail and Yanboa’. Marafiq has planned to build new desalination plants to cover existing and future water needs of its industrial cities.

Al Jubail is located in the Eastern Province on the Arabian Gulf and contains one industrial city. All of the treated wastewater, approximately 12,000 m3/day, is reused for landscaping in the industrial city.

Yanboa’ Industrial City is located on the Red Sea in the Madinah region. The current water demand for industry is approximately 54,000,000 m3/year, which is expected to increase to 59,000,000 m3/year in 2014.

1.9 Current Status of Reuse Regulations Current technologies make high-quality purified water from wastewater feasible; regulations are used to ensure that public health and the environment are protected with the application of RQTSE, which can be used both directly and indirectly in a variety of applications. The regulatory framework for reuse should also work to create public trust in the ability of RQTSE to play a major role in water resources management within KSA as demands on existing groundwater and desalinated water supplies increase with a growing population and favorable economic climate for industries.

KSA has recognized its water supply limitations as its population has grown and has begun more defined water resources planning with the National Water Plan in 1985, now updated as the National Water Strategy. With progress such as KSA’s plan for nearly complete reuse by 2025 in cities over 5,000 people, the current regulatory framework under the authority of MOWE and Ministry of Agriculture (MOA) is built on the following principles:

• Achievement of at least minimum treatment standards • An approval and permitting process for the application of RQTSE • Monitoring of RQTSE to ensure that it meets the standards • Enforcement provisions to ensure that RQTSE practices are following requirements

The first regulation specifically focused on reuse was published in May 2000, “Treated Sanitary Wastewater and Its Reuse Regulations.” Applications requiring secondary or tertiary treatment were specified. However, water quality standards were not listed; instead, the regulations called for the creation of Rules of Implementation (ROI). The first water quality specifications included only BOD5, TSS, and fecal coliform. Later, specific but limited ROI were developed and published (Saudi Aramco, 2009). These implementation rules are typically valid for a period of 5 years, were validated in 2005 and updated in 2010, but not yet approved. Further details regarding proposed rules are provided in Chapter 7.

Private Reuse Practices Some private entities, such as Saudi Aramco, have established their own engineering standards to ensure that public safety is protected as they institute reuse practices. In the case of Aramco, the standards follow California (USA) Title 22 but also comply with KSA rules.



The General Environmental Regulations and Rules for Implementation (GER&R) were adopted in October 2001 and set forth requirements for environmental protection. The GER&R sets forth rules to protect natural resources specifying:

• The basis for regulating actions having environmental impacts • Procedures for the coordination of response operations • Pollution control and compliance • Types of environmental violations and

associated penalties

The GER&R did not specifically address water quality standards for RQTSE, groundwater aquifer recharge, or biosolids applications and neither do the current ROI concerning the Reuse Law. In 2006, MOWE published the booklet entitled “Using Treated Water for Irrigation; Controls-Conditions-Offences and Penalties.” The adoption of these standards was an important step in establishing and providing for the implementation of safe reuse practices. Treatment parameters are presented in Chapter 7. The application requirements and restrictions for the use of treated wastewater for agricultural purposes are defined by two levels of treatment as shown in Figure 1-19.

In addition, RQTSE is suitable as a water source for animals and birds that are not designated for human consumption.

1.9.1 Specifications The current KSA requirements for restricted irrigation meet the World Health Organization (WHO) recommendations, as do the more stringent unrestricted irrigation requirements.

Most of the requirements for unrestricted irrigation are similar to others around the world, including those in California, USA.

Agricultural productivity should be enhanced by reuse, not deteriorated by misapplications. To ensure the separation of RQTSE from potable water infrastructure and wells, regulations include separation methods such as distance, pipe labeling, and timing. Worker safety is also a priority. The primary constituents of concern in treated wastewater for agricultural use are:

• Suspended solids, since filtration may be needed, particularly with micro-irrigation systems

• Nutrients, to adjust fertilization amounts and schedules while limiting algal growth

• Salinity, to estimate the leaching fraction and to select appropriate cropping patterns

• Pathogens, with precautionary health actions, such as selecting appropriate cropping patterns and choosing the most suitable irrigation system

• Metals, since high levels can be toxic to plants

Industrial reuse applications may have requirements that extend beyond regulated parameter limits, to include lower turbidity, dissolved solids, and/or nutrient limitations (depending on the application) compared to those required of unrestricted irrigation. Large-scale industrial users may provide their own treatment.

FIGURE 1-19 Agricultural Reuse Categories



Given the biosolids application benefits of providing nutrients and enhancing soil moisture retention, a market for the reuse of biosolids in agriculture is present in KSA. To promote the protection of public health and the maximum reuse benefits, testing and monitoring of biosolids prior to application are required. Current sludge application criteria for KSA are presented in Chapter 7. MOWE’s requirements for sludge application are generally consistent with international best practices.

Specific aquifer recharge water quality standards are not included in the current regulations; instead, standards are assessed using a case-by-case approach for each permit.

1.9.2 Enforcement Fines and penalties are in place for violations of the requirements. The lowest penalties are for violations such as failing to mark the irrigation system with appropriate warning signs or preventing site inspections. The highest fines are for using raw wastewater or sludge in agriculture or placing raw sewage in irrigation canals or drains.

1.10 Public Awareness and Acceptance The Saudi Water Act (Saudi Water Act, 2010) provides that MOWE, in coordination with the MOA, Ministry of Education and Ministry of Higher Education, Ministry of Islamic Affairs, and Ministry of Culture and Information, is responsible for preparing a water education strategy to promote a culture in which the population is aware of water problems and challenges and is capable of addressing them. The education strategy addresses educational decisions and performance, textbooks, activities, speeches, lessons, religious rituals, cultural activities, and media of all types. In addition, all water service providers and public agencies are required to report their initiatives in water awareness and education, and the results, in their annual reports.

Successful water management practices and policies take into account local cultural and religious traditions, values, and beliefs. Policies and projects have been accompanied by public education programs and the issuance of a fatwa; however, the public is only slowly accepting that RQTSE is a safe water resource and an important way to reduce demands for expensive potable water in this arid region. As discussed previously, many urban areas do not have complete wastewater infrastructure or wastewater treatment systems. With this knowledge, many in KSA are concerned about the Kingdom’s ability to establish reclaimed water systems and demand for this resource (Maliva et al., 2011).

Islamic Law requires pure water for certain purposes, including ablution and defines how the water can be made pure. In support of the use of reclaimed water, The Council of Leading Islamic Scholars in KSA issued a fatwa in 1978, stating that reclaimed water, if treated sufficiently to ensure good health, is considered pure because the impurities are removed from it during the treatment process. This includes uses such as ablution, which has been difficult to accept for many Muslims in KSA. Its use as drinking water is not recommended, but the rationale relates to public health, not Islamic Law. Reuse treatment technologies that can produce reclaimed water and are consistent with the ways water can be made pure under Islamic Law are discussed in Chapter 2.

More wastewater collection and treatment infrastructure will be constructed in KSA to meet goals for service in 2025. Improving public perceptions of the value of reusing treated wastewater and biosolids recycling will be crucial for ensuring that the effluent and biosolids

Effluents May Regain their Original Pure Character Through: • Treatment • Dilution with a larger quantity of pure (tah¯ur)

water • The passage of time



produced will be beneficially reused. Along with the significant infrastructure capital investment, an investment in more effectively informing the public of the value of these resources is needed. Helping establish public recognition of the value of reclaimed water through education and other methods is further discussed in Chapter 3.

1.11 Water, Wastewater, and Reuse Business Status The NWC is a Saudi company fully owned by the government (specifically the Public Investment Fund) and the NWC Board is chaired by the Minister of Water and Electricity. It was established by Royal Decree in January 2008 to restructure and provide drinking water and wastewater services under MOWE, as a public company under the name National Water Company. Services are provided in accordance with the latest international standards through working with various international operators. The NWC’s operational responsibilities include water extraction, production, purification, treatment, and distribution services, as well as wastewater treatment and purification. NWC is focusing on making maximum use of RQTSE. Its activities also include participation in the training and qualifying of Saudi nationals, establishment of training programs, and research and development activities to ensure the transfer of technology.

The goal of the NWC is to build and maintain a strong water and wastewater infrastructure and provide excellent services that meet the needs and desires of customers. NWC focuses on providing drinking water of high quality for all customers, providing all households with water and wastewater connections, preserving natural water resources, protecting the environment, and developing and training qualified Saudi employees in accordance with the latest international standards.

The services of the NWC are being provided in stages dictated by MOWE according to sound business practices. MOWE maintains its strategic role in establishing the national water plan, and introducing laws and legislations that regulate the water and waste water services in the Kingdom.

Currently, the NWC is preparing integrated master plans for the cities that it serves and will serve in the future. These integrated plans will provide the detailed information necessary for specific planning for infrastructure, capital, and other types of expenditures. The NWC is already providing services in both Riyadh and Jeddah, the most populated and most rapidly growing cities in the Kingdom. Makkah and Al Taif have recently been included in the NWC services and functions, and Al Madinah and Dammam will be added in the near future. NWC has begun the implementation of its contracts: one with the French company Veolia, to manage water and wastewater services in Riyadh for 6 years; and the other with Suez and ACWA Power Development, its local partner, in Jeddah for 7 years.

Recently, the NWC announced plans to privatize the following:

• In Jeddah, one new industrial WWTP that is under construction and designed for the treatment of 50,000 m3/day of sanitary and industrial wastewater. The NWC will manage the sale of the RQTSE for industrial purposes in the industrial zones located south of Jeddah and is responsible for constructing the system for transporting the RQTSE to that area.

• The existing 240,000-m3/day WWTP as well as a new 200,000-m3/day plant to be constructed in Al Madinah.

NWC Providing Staged Water and Wastewater Services • Current service in Riyadh and Jeddah • Recently included service to Makkah and Al Taif. • In near future will serve Al Madinah and

Dammam



1.12 Summary KSA has a number of goals for providing water, wastewater, and reuse infrastructure in cities with populations greater than 5,000 people. In general, it is planned that the coverage for water supply and sewage collection will be nearly 100 percent in these cities by the year 2025. It is also planned, in general, that all of the sewage collection systems will be connected to WWTPs by the Year 2025. With many WWTPs currently under construction, the existing sewage treatment capacity in KSA will more than double when operational. Further, it is planned that all RQTSE will be beneficially reused.

Current water supplies consist of desalinated water, which is expensive to produce, and groundwater, which is a non-renewable or slowly renewable resource. The growth in population in KSA will significantly increase both water demands and wastewater flows. The increase in coverage by water distribution systems and sanitary sewer systems will add to these increases. The significant amount of additional RQTSE expected to be generated provides an important opportunity for reuse to offset water demands for non-potable uses. The use of reclaimed water for cooling by industries or commercial enterprises, and possibly by public buildings, could increase due to the high expense and environmental costs of using desalinated water or groundwater for such purposes.

A large supply of TSE that is currently discharged from WWTPs is unused. Current reuse of RQTSE in the six largest cities ranges from none in Makkah to 3 percent in Dammam and to nearly 100 percent in Al Madinah. In Riyadh, RQTSE reuse is approximately 66 percent and in Jeddah it is 17 percent. This resource is probably not being used for a number of reasons, including lack of distribution infrastructure, lack of public awareness and acceptance, and lack of financial incentives.

Biosolids are another renewable resource that can be recycled but which are currently being disposed of by landfilling or disposal at designated locations. There is little indication that biosolids are beneficially reused. Requirements for the use of biosolids in agriculture exist, but there appears to be generally little awareness among farmers of the benefits of using sludge in agriculture.

Therefore, along with the significant infrastructure capital investment planned to meet the service goals for 2025, an investment in better informing the public of the value of these resources is needed.

1.13 Information Gap Analysis While significant information is available to characterize the demand for water in KSA, how wastewater treatment is improving both in capacity and quality, and how treated wastewater can be a valuable resource in this arid region, it appears that other important information is currently undocumented or unaddressed. The following information would be very useful in better defining parameters so that the wastewater, reuse and biosolids management situation in KSA can be more accurately described.

• Influent Wastewater Characterization: The measurement of influent wastewater flows, parameters and concentrations over several years would be useful to help characterize the influent wastewater which will impact the selection and design of appropriate treatment technologies as well as the estimation of capital and O&M investments required for new facilities. This information would provide important details for the

An investment in better informing the public of the value of reuse of RQTSE and biosolids is critical, along with the significant infrastructure capital expenditures that are planned.



Technology Overview (Chapter 2) and Business Opportunities (Chapter 4) portions of this Strategic Study.

• Wastewater Treatment Processes and Treated Flows: Measurements of treated wastewater flows over several years to establish a baseline would provide important information for facility planning. Most WWTPs are defined as having secondary or tertiary levels of treatment. However, details of the treatment processes as well as the technologies used for filtration and disinfection would provide a better understanding of the degree of treatment provided.

• Wastewater Biosolids: Very little information appears to be available about whether WWTPs have biosolids management facilities, the quantities of biosolids generated, and how they are handled, processed and disposed. To better characterize the biosolids situation in general, information regarding the amount of biosolids generated along with the associated influent wastewater flows and influent parameters is needed. It appears that current disposal methods include landfilling or disposal at designated locations but more information regarding these or other practices being employed, such as reuse, would help better define current activities. Biosolids from the Madinah WWTP are being reused but there are few details regarding how they are reused.

• Unsewered City Areas: Only portions of cities are currently provided with sewage collection systems (for example Riyadh has only 50 percent coverage). Information regarding how sewage generated in the remaining area of the cities (not served by an existing collection system) is collected and treated is needed to provide a more complete understanding of the quantities of wastewater generated and treated. This information would also provide further insight into the Septage Handling and Treatment issues presented in Chapter 8.

• Wastewater Flow Calculation Methodology: It would be useful to revisit the methods used to develop wastewater flow projections especially because decisions regarding large capital projects are based on the projections. Information reviewed for this study indicates that potentially different data sources and different assumptions may have been used by different agencies to develop flow projections. An agreed-upon methodology could serve as a valuable common basis for future planning. In addition, measuring treated wastewater flows and correlating those over time to actual populations served would help establish a per capita wastewater flow baseline.

• Strategies for Cities < 5,000 People: Although management of wastewater in cities > 5,000 people is a monumental first task being undertaken, thought should be given to how wastewater can be best managed in the future in very rural areas and smaller cities. There may be new strategies and business opportunities for reuse in these smaller locations.

• Water Conservation Strategies: Reducing water demands by promoting water conservation could help reduce the quantity of needed new water supplies. A review of water conservation in KSA would identify the current practices, how widespread conservation is, how the concepts of conservation are communicated, and successes that may have been achieved. Setting conservation targets is a method that is frequently used to communicate the need for and benefits of conservation.

In addition, there are needs for:

• Conducting public education and branding of RQTSE as a resource; this is discussed in Chapter 3 – Public Education and Awareness. Addressing the gaps listed above will further improve public education efforts, as more trust can be gained with the availability of RQTSE quality data.



• Identifying business opportunities not just for RQTSE but also for biosolids reuse; these are discussed in Chapter 4 – Business Opportunities

• Establishing an updated/expanded regulatory framework; this is discussed in Chapter 7 – Regulatory Considerations

1.14 References Dr. Mohammed Al-Saud. The Importance of Developing Sustainable Water Resources in the Kingdom: Strategies for the Future. Jeddah. 31-05-2011.

Geohive. 2010 Census Population. www.geohive.com. Accessed June 2011.

Global Water Intelligence. Global Water Market 2011; Volume 3; Middle East and Asia Pacific. 2011.

ItalConsult Draft Wastewater Reuse Planning Reports prepared for the Ministry of Water and Electricity (MOWE) for each of the 13 Regions:

• Al Baha; February 2010 • Al Jouf; July 2009 • Assir; December 2009 • Eastern Province; January 2010 • Hail; July 2009 • Jizan; March 2010 • Al Madinah; January 2010

• Makkah; October 2009 • Najran; August 2009 • Northern Borders; June 2009 • Qaseem; October 2009 • Riyadh; December 2010 • Tabouk; July 2009

Kingdom of Saudi Arabia; Ministry of Water and Electricity (MOWE). 2006. Using Treated Water for Irrigation; Controls-Conditions-Offences and Penalties.

Kingdom of Saudi Arabia; Presidency of Meteorology and Environment; General Environmental Regulations And Rules for Implementation (Translated From the Official Arabic Version); 15 October 2001.

Kingdom of Saudi Arabia Central Department of Statistics and Information (CDSI). 2010 Census Population. www.cdsi.gov.sa. Accessed June 2011.

Loay Al-Musallam, CEO, National Water Company, Presentation at 6th WEPOWER Conference, Dammam, 7 June 2010.

Malvia, Robert G.; Missimer, Thomas M.; Winslow, Frank P.; Herrmann, Rolf. 2011. Aquifer Storage and Recovery of Treated Sewage Effluent in the Middle East. Arabian Journal for Science and Engineering; ISSN 1319-8025; Volume 36, Number 1, 2011.

Metcalf & Eddy. 2003. Wastewater Engineering, Treatment and Reuse; Fourth Edition.

Nasser Al-aamry, Sr. Manager, Business Development, National Water Company, New Development Initiatives at a Glance, 2010-2011.

National Water Company Jeddah City Business Unit. Wastewater Sludge Management. May 2011.

Personal Communication with National Water Company Jeddah City Business Unit. Bill Kreutzberger/CH2M HILL with NWC. April 2011.

Personal Communication with National Water Company Riyadh City Business Unit. Bill Kreutzberger/CH2M HILL with NWC. June 2011.



Saudi Aramco. 2009. “Water Reuse Regulations in Saudi Arabia” presented at Water Arabia, March 2009.

Saudi Water Act. 2010. English Translation of March 2010 Arabic Version.

Samhouri, Wael. Wadi Hanifa Wetlands, Riyadh, Saudi Arabia. 2010 On Site Review Report.

Zanoni, A.E. and Rutkowski, R.J. 1972. Per Capita Loadings of Domestic Wastewater. Journal of the Water Pollution Control Federation; Vol. 44, No. 9, Sept., 1972.

STRATEGIC SUMMARY

Chapter 2: Technology Overview

2.1 Introduction and Objectives Current technologies are highly effective in treating wastewaters to produce purified water which can be used for high-quality industrial purposes as well as direct and indirect potable reuse purposes. Providing reliable wastewater service and safe drinking water are highly energy‐intensive processes. Wastewater pumping and aeration processes for treatment typically account for the largest energy demand among the various operations at most wastewater treatment facilities. Although the demand is site‐specific and can vary widely from plant to plant, the fraction of energy used for aeration ranges from 25 to as much as 60 percent of the total plant energy use in the USA (USEPA, 2010). Use of advanced treatment processes such as low- and high-pressure membranes, or advanced oxidation using UV light, further increases energy use at the treatment plants.

Sustainable wastewater treatment and reuse practices with reduced carbon footprint are becoming a goal of a number of visionary leaders in the industry. Numerous innovative technologies that can offer sustainable, low carbon footprint wastewater treatment and reuse have been recently demonstrated, or are in developmental stages. This chapter identifies technologies that can be applicable for wastewater treatment, reclaimed water, and beneficial reuse in KSA. The central focus of this chapter is the innovative and developmental technologies that show promise in one or more of the following areas:

• Reduce energy use and carbon footprint without sacrificing treatment efficiency

• Use waste or low grade heat to achieve treatment while reducing energy demand and O&M costs

• Generate energy using wastewater or wastewater solids

• Recover resources from wastewater, biosolids, or concentrate streams

• Effectively inactivate/remove pathogenic organisms without producing disinfection byproducts (DBPs)

Because descriptions and capabilities of established and emerging technologies can be found elsewhere (Metcalf and Eddy, 2003, Metcalf and Eddy, 2007, USEPA, 2008, etc.), those technologies are not covered in depth; rather, summary tables are provided in Appendix A.

Technologies used for water reclamation and reuse have been categorized as being established, emerging, and innovative/developmental and are described as follows:

Established Technologies: Have been used at more than 30 full-scale facilities across the world or have been available and implemented for more than 5 years (e.g., membrane bioreactor [MBR], granular media filtration, chlorine disinfection). A technology that represents an innovative use of an established technology (e.g., established technologies used in drinking water applications and for industrial wastewater treatment such as electro-dialysis reversal [EDR], ballasted flocculation) is also considered as “established technology.”

CHAPTER 2: TECHNOLOGY OVERVIEW

2-2 STRATEGIC SUMMARY

Emerging Technologies: Technologies that have been tested at demonstration scale, have been implemented at fewer than 30 full-scale facilities, or have been available and implemented for less than 5 years.

Innovative/Developmental Technologies: Technologies that have been tested at bench or pilot scale, with no full-scale applications (forward osmosis [FO], anaerobic membrane bioreactor, membrane biofilm reactor, etc.).

Information presented on these technologies includes the objectives, application area(s), state of development, where and when the technology has been tested or implemented (if applicable), testing results, state of development, and implementability of the technology.

The above information is organized in this chapter as follows:

• Current Beneficial Use Schemes and Available Technologies

• Innovative and Developmental Technologies for Wastewater Treatment and Water Reuse

• Comparison of Innovative/Developmental Products and Technologies

• Impact of Wastewater Quality on Operation and Performance of Unit Treatment Processes

• Industries in KSA with Reuse Potential

• Summary and Path Forward

2.2 Current Beneficial Use Schemes and Available Technologies

The need for alternative water resources, coupled with increasingly stringent water quality discharge requirements, are the driving forces for developing water reuse strategies in the world today. The growing trend is to consider water reuse as an essential component of integrated water resources management and sustainable development, not only in dry and water-deficient areas, but in water-abundant regions as well. Depending upon the intended use (landscape irrigation, agricultural irrigation for edible crops, industrial reuse, indirect potable reuse, etc.), an appropriate wastewater treatment technology can be coupled with disinfection only, whereas some in cases it is coupled with filtration and disinfection or advanced treatment technologies (i.e., MF, RO) to meet water quality requirements for the intended reuse options. For example, conventional treatment technologies presented in Figure 2-1 can satisfy reclaimed water treatment requirements for restricted and landscape irrigation, whereas more advanced technologies are required for higher-quality reuse schemes (such as agricultural irrigation for hydroponics, some industrial reuse, and indirect potable reuse). Some examples are depicted in Figure 2-2.

FIGURE 2-1 Examples of Reclaimed Water Schemes (Filtration can be performed using a range of approaches including granular [top] and cloth media [bottom])


STRATEGIC SUMMARY 2-3

FIGURE 2-2 Examples of Reclaimed Water Schemes for High-Quality Uses Because of the importance of water quality in wastewater treatment and reuse applications, different technologies can be used to achieve the desired degree of contaminant removal. The principal unit operations and processes, along with the capabilities of unit treatment processes used in wastewater treatment and water reuse applications, are presented in Appendix A. The most commonly used secondary treatment technology in KSA is the CAS systems, while filtration and disinfection provided by media filtration and chlorination are the most common tertiary treatment technologies. Only a few advanced wastewater treatment facilities utilizing RO have been identified. The details on current wastewater and reuse technologies used in KSA are provided in Chapters 1 and 4. Technology selection involves careful consideration and evaluation of numerous factors to meet current and future reclamation requirements and regulations. The key factors include type(s) of water reuse application, wastewater characteristics of the process feed stream, water quality goals, energy requirements, chemical requirements, process flexibility, O&M requirements, personnel requirements, and site-specific constraints (Metcalf and Eddy, 2007).

As the regulations for treated effluent quality become more stringent, energy consumption by the treatment facilities will increase. As depicted in Figure 2-2, many RO facilities located in coastal areas discharge RO concentrate to large water bodies (sea, ocean, etc.). Although this approach may be the only feasible and cost-effective solution at present, there is an increasing interest in treating RO concentrate to reduce pollution and recover nutrients, metals, and salts from the concentrate streams.

The prospect of depleting the world’s mineral rock phosphate reserves is of great concern to the food and agriculture industry and is increasingly being compared to the concerns regarding depleting the world’s oil supply. While total global phosphorus reserves remain unknown, statistics on deposits found in recent decades indicate that more phosphate is being extracted than discovered. Despite technological and methodological advances, new deposits are fewer and of lower quality than previously predicted. Unlike carbon and nitrogen, which can be fixed from the atmosphere, phosphorus cannot be fixed. On the other hand, there is always excess phosphorus present in municipal wastewater. In the USA, water quality based regulatory initiatives have been implemented to reduce phosphorus discharge to receiving waters. Two primary regulatory approaches have been used in both the municipal and industrial sectors to meet this goal: restrictions on the use of phosphorus-based products such as phosphate-based detergents (source control) and strict control of phosphorus discharges (effluent treatment limits). Phosphorus recovery methods have not been used to any significant extent.



New developments in microbial fuel cell technologies (Liu et al., 2004; Love, 2007) are making progress in capturing the energy from liquid wastewater, but the research is still in the early stages. While there is opportunity for the wastewater industry to meet its own energy demand in the future, only energy in the solids can be extracted with current technologies.

Sustainable wastewater treatment, with a reduced carbon footprint, is becoming a goal of major interest. Such interest has shifted the view of municipal sewage from a waste to be treated and disposed of, to a valuable resource that can be processed for recovery of energy, nutrients, salts or other constituents. Long-term trends indicate the potential for increased interest in resource recovery from wastewater. Figure 2-3 presents intended use examples with full treatment.

FIGURE 2-3 Examples of Intended Use with Full Treatment Currently, a diverse group of technologies are available for wastewater treatment and reuse. While some technologies have been proven (such as CAS systems, MBRs, media filtration, chlorine disinfection, RO), some technologies are yet to be developed (FO, membrane distillation, microbial fuel cell, algae biofuel, etc.) to meet energy reduction, resource recovery, and full-treatment goals. As noted above, descriptions and capabilities of proven, commercialized, and widely used technologies can be found elsewhere (Metcalf and Eddy, 2003, Metcalf and Eddy, 2007, USEPA, 2008, etc.). Therefore, this chapter covers only innovative and developmental technologies in detail. Summary tables are included in Appendix A-1 to show the primary use and capabilities of established and emerging technologies. Appendix A-2 summarizes commercially available resource recovery and biogas generation technologies.



2.3 Innovative and Developmental Technologies for Wastewater Treatment and Water Reuse

As noted above, providing reliable wastewater service and safe drinking water are highly energy‐intensive processes. The Consortium for Energy Efficiency (CEE), located in the USA, has estimated annual energy usage at approximately 100 billion kilowatt-hours (kWh) in the USA for providing safe drinking water and effective wastewater treatment. Assuming an average energy cost of $0.075 per kWh, the energy cost for providing water/wastewater treatment is approximately $7.5 billion per year (USEPA, 2010); conveyance costs are not included in these estimates. Numerous research/demonstration studies have been performed in recent years to explore energy-efficient, low carbon footprint, resource recovery technologies. While some of these technologies have been successfully demonstrated and have already been commercialized (such as FO and DEMON®), some technologies need further demonstrations and advancements before they can be successfully commercialized.

This section summarizes innovative and developmental technologies that are applicable to wastewater treatment and wastewater reuse. This section also summarizes, for each technology discussed, the specific application area, treatment objective, development status, description of technology, and advantages and disadvantages compared to the established technologies. Additional discussion is provided on potential implementation, scalability, and advancement needs for each technology. Limited cost data are available for the majority of the technologies, because of the immature development status of emerging technologies. The innovative/developmental treatment technologies are classified based on the following:

• Physical-chemical: these technologies use physical and/or chemical means to remove pollutants and/or recover resources.

• Biological: these technologies use microorganisms to degrade organic contaminants from wastewater and/or recover resources.

• Natural: these technologies may incorporate either physical-chemical or biological treatment; however, they use minimal external energy input to achieve the treatment objectives.

• Resource Recovery Technologies: these technologies uses physical chemical and/or biological treatment principles to recover resources from wastewater in the form of nutrient, salt, biogas and electricity

2.3.1 Innovative and Developmental Physical–Chemical Treatment Technologies Innovative Desalination Technologies Wastewater agencies are implementing advanced treatment technologies in response to increasingly stringent treatment requirements, as well as concerns over contaminants (such as pharmaceutically active compounds, personal care products, and endocrine-disrupting compounds) and other pollutants in their systems. One such technology is desalination, a process that removes dissolved compounds such as salts and organic compounds. Despite the advances in desalination technology in the past three decades and wide acceptance of conventional membrane and thermal desalination technologies for effectively treating various source of waters, concerns associated with cost, energy consumption, and environmental impacts (such as impingement and entrainment, concentrate discharges, greenhouse gas [GHG] emissions) are limiting their implementation in various treatment applications. To address one or more of the concerns mentioned above, numerous research studies have been conducted to develop energy-efficient technologies and technologies that use renewable energy and low grade and waste heat to desalinate wastewater. The majority of these technologies have been developed for brackish water or seawater desalination; the same technologies can also be applicable to wastewater if proper pretreatment is provided.



The innovative/developmental technologies reviewed in this chapter are described below in alphabetical order.

Capacitive Deionization (CD) Application Area Desalination of brackish water and wastewater. Treatment and recovery of RO concentrate streams.

Objective To lower the carbon footprint of desalination.

Status Developmental.

Description of the Technology The original CD process was developed and patented at Lawrence Livermore National Laboratory in the late 1980s.

CD is a low-pressure, non-membrane desalination technology that uses electrostatic forces to remove dissolved ions from solution. An aqueous solution of soluble salts is passed through pairs of electrodes held at a potential difference of 1.2 volts (v). The electrodes consist of porous carbon aerogel, with a specific surface area of 400 to 1,100 square meters per gram [m2/g] and with very low electrical resistivity (less than 40 kilohm-meters). Ions are adsorbed to the electrode of opposing charge in a semi-batch process. Eventually, the electrodes become saturated with ions and must be regenerated. To regenerate CD, the applied potential is removed, and the ions attached to the electrodes are released and flushed from the system. Flushing of cells using a small quantity of product water generates a concentrate stream, as shown in Figure 2-4. Unlike ion exchange processes, no additional chemicals are required for regeneration of the electrosorbent in this system.

FIGURE 2-4 CD Operation (top) and Regeneration (Bottom) Carbon aerogel is an ideal electrode material because of its high electrical conductivity, high specific surface area, and controllable pore size distribution. However, despite recent advancements, carbon aerogel electrodes are still expensive and their ion storage capacity is relatively low.

Original designs of CD systems were limited to the treatment of relatively low ionic strength solutions (total dissolved solids [TDS] < 3,000 milligrams per liter [mg/L]). The reason for



their limited application has been identified as the high pore volume to surface area characteristic of the carbon electrode material. The high pore volume of the material traps salts like a sponge, resulting in coulombic inefficiencies (Seed et al., 2006).

The technology has been investigated in several academic and research institutions. In the USA, Colorado Schools of Mine researchers concluded that this technology could yield results comparable to those of conventional RO for desalination of streams with TDS of less than 3,000 mg/L (Kristen, 2006). This is mainly due to the high cost of CD modules with increased feed water TDS concentrations.

Capacitive Deionization Technology Systems, Inc. (CDT Inc.) is the worldwide licensee for the patented CD technology for water purification and desalination applications. CDT Inc. had a manufacturing and marketing license with TDA Research, Inc. and obtained worldwide rights to TDA Research's patented Porous Carbons from Carbohydrates for the manufacture of electrodes for use in CD systems. CDT Inc. filed bankruptcy in 2008. Independently, ENPAR Technologies Inc. of Canada has developed its DesEL System, which uses principles of CD to remove TDS.

Comparison to Established Technologies Potential Advantages over Established Technologies • CD requires less energy than EDR, nanofiltration (NF)/RO, and mechanical/thermal

processes

• Membrane technologies require more advanced operation and construction considerations for high-pressure pumps and clean-in-place (CIP) systems. The CD operates at ambient conditions, and there are no requirements for high-pressure pumps and CIP systems

• CD uses electrostatic regeneration and requires minimal or no chemicals for electrode fouling and scaling controls

• Less scaling propensity compared to NF/RO

• Silica does not limit the recovery compared to NF/RO

Potential Disadvantages Compared to Established Technologies • CD is still under development. Knowledge about treatment efficiencies of larger-scale

installations, economics, and short- and long-term fouling/scaling issues of CD systems has not been established.

• Lower TDS removal than RO and mechanical/thermal processes. The process cannot remove uncharged molecules (such as boron, silica, and non-polar organic compounds). CD recovers lower amounts of water than conventional membrane processes

• Does not provide a barrier against solids and pathogens

• Adsorption of total organic carbon (TOC) to the aerogel material during regeneration when the cell is uncharged could result in electrode fouling if organic matter clogs the pores of carbon aerogel material

• Lengthy down-time period during cleaning of electrodes

Technology Tested/Implemented or Demonstrated Currently, there is no known full-scale CD facility.

Numerous bench and/or pilot testing studies have been conducted over the last 5 years. In a bench-scale study, Seed et al. (2006) showed that CD can achieve 80 percent TDS removal with high water recoveries (up to 95 percent). However, the feed water TDS was only 460 mg/L during bench-scale testing. Tao et al. (2009) used a pilot-scale CD unit to treat and recover an RO concentrate stream generated from the Kranji NeWater Reuse RO



facility in Singapore. Biological activated carbon pretreatment followed by CD resulted in 85 percent TDS removal efficiency at approximately 85 percent recovery. Tao et al. (2009) reported a cell energy consumption of 0.7 KWh/m3 based on the pilot CD testing results. Similar to the previous study, the feed TDS concentration of CD was relatively low (1,250 mg/L). This is a lower level of TDS than is found in wastewaters in certain regions of KSA (2,500 and 4,000 mg/L).

A comprehensive evaluation performed by the Colorado School of Mines (U.S. Bureau of Reclamation [USBR], 2009) concluded that the energy consumption of CD is similar to that of RO (4 kWh/1,000 gallons [kgal], or 1.1 kWh/m3) for low flow systems (0.7 milliliter per minute [mL/min]). The CDT designed for a 3-L/min system was reported to have much higher energy consumption as a result of high current requirements of the electrodes. The Colorado School of Mines study also concluded that the water treatment cost of CD was much higher compared to membrane processes due to its lengthy down-time and low product water recovery (USBR, 2009).

Knowledge Gaps/Future Advancements/Implementability The efficiency and recovery of the process need to be improved before CD becomes economically feasible to treat relatively high TDS water (>5,000 mg/L). CD could probably be implemented within the next 5 to 10 years, if the following improvements are made (USBR, 2009):

• Higher capacitance and lower cost of electrode materials • Faster charging and discharging of electrodes • Recovery of residual electricity • Shorter regeneration time to reduce process down-time • Reduced carryover volume after regeneration • Cost-effective and low carbon footprint pretreatment technologies

According to the literature, relatively low TDS streams (<3,000 mg/L) are the potential candidates for CD application. Similar to EDR, this modular technology can be applicable at small- to large-scale systems. Unit investment cost ($/m3) is expected to be lower as plant capacity increases due economies of scale.

Cost Information Not established

Technology Supplier ENPAR Technologies Inc. 70 Southgate Drive, Unit 4 Guelph, Ontario, Canada N1G 4P5 Tel: 519-836-6155 Fax: 519-836-5683 [email protected]

Forward Osmosis (FO) Application Area Desalination of seawater, brackish water, and wastewater. Treatment and recovery of RO concentrate streams

Objective To lower the carbon footprint of desalination process

Status Developmental

mailto:[email protected]



Description of the Technology FO is an innovative membrane-based technology that has the potential to reduce the costs and environmental impacts of desalination. This is an osmotic process that uses a semi-permeable membrane to separate salts from water. FO uses an osmotic pressure gradient (∆п) instead of hydraulic pressure (∆P), which is used in RO, to create the driving force for water transport through the membrane. No energy is needed to drive the water flux of an FO process, as the water flux is the natural tendency of the system. Figure 2-5 illustrates a conceptual batch FO and RO processes.

FIGURE 2-5 Schematic Illustration of FO and RO The concentrated solution, or draw solution, is the source of the driving force in the FO process. A selectively permeable membrane allows passage of water, but rejects solute molecules and ions. Osmotic driving forces in FO can be significantly greater than hydraulic driving forces in RO. This results in the potential for higher water flux rates and recoveries. The selection of an appropriate draw solution is the key to FO performance. The draw solution should:

• Have a high osmotic efficiency (that is, have a high solubility in water and a low molecular weight)

• Be non-toxic; trace amounts of chemicals in product water might be acceptable

• Be chemically compatible with the membranes

Example draw solutions include magnesium chloride, calcium chloride, sodium chloride, potassium chloride, ammonium carbonate, and sucrose. A simplified process schematic of an FO process using ammonium carbonate as a draw solution is presented in Figure 2-6.



FIGURE 2-6 Simplified Process Schematic of FO (Adapted from McCutcheon et al., 2007) Comparison to Established Technologies Potential Advantages over Established Technologies • Operates around 1 atmosphere (atm), which results in much lower energy consumption

compared to conventional membrane and mechanical/thermal evaporative desalination technologies

• Membrane compaction is not typically an issue

• Less fouling propensity compared to RO

Potential Disadvantages Compared to Established Technologies • Still under development. Knowledge about the following has not been established:

treatment efficiencies of larger-scale installations, economics, and short- and long-term performance and fouling/scaling

• Requires special membranes. Existing commercially available RO membranes are not suitable for FO because such membranes have a relatively low product water flux, which can be attributed to severe internal concentration polarization in the porous support and fabric layers of RO membranes

• Use of ammonium carbonate as draw solution may provide desired osmotic pressure. However, diffused ammonia to the permeate stream should be removed using a low cost technology (such as waste heat to strip ammonia)

Technology Tested/Implemented or Demonstrated Early applications of FO include fruit juice concentration where the concentrate becomes the product (Huehmer and Wang, 2009). Water supply and wastewater treatment research has historically focused on treatment of contaminated waters. CH2M HILL conducted studies on



the use of an FO/RO process for the treatment of landfill leachate in Oregon in the USA (Huehmer and Wang, 2009). The University of Nevada – Reno, also in the USA, has conducted research on the use of FO for centrate dewatering and water recycling. More recently, the USA National Aeronautics and Space Administration (NASA), in conjunction with the University of Nevada, has investigated use of FO in closed-system water recycling. Research is being conducted by the Nanyang Technological University in Singapore on the use of osmotic membrane bioreactors. Several research studies have been or are being conducted to identify draw solutions and membrane types and to evaluate the merits of the FO process (McCutcheon et al., 2007; Cath et al., 2009; Hancock and Cath, 2009).

Various approaches for FO-based desalination exist. In the USA, a pilot-scale FO unit was built and has been operated at the Yale University laboratory since 2005. The Yale pilot study utilizes an ammonium carbonate solution as the draw solution. To recover freshwater, the diluted ammonium carbonate solution is heated to approximately 55oC, where ammonium carbonate undergoes thermal decomposition. The Yale research is being commercialized by Oasys Water Inc. Modern Water PLC has constructed a 25,000-gallon-per-day (gpd) pilot facility in Gibraltar for sea water as a desalination demonstration (Water Desalination Report, 2008). Additional facilities located in Oman are being developed by Modern Water.

FO has been investigated as a concentrate management technique. Studies have been conducted by the Colorado School of Mines and Carollo Engineers on the use of a coupled FO/RO process to reduce RO concentrate volumes.

Several researchers have investigated the use of FO as a potential energy source using pressure restrained osmosis (PRO). Loeb (1998) first demonstrated the feasibility of energy production by PRO. In 2009, Statkraft, the national energy company of Norway, commissioned a demonstration PRO power plant in Tofte, Norway. With 2-kW capacity, the facility is a proof of concept test bed.

Although the understanding of the principles of FO and interest in its use precede current investigations by several decades, recent developments have greatly improved the prospects of applying this technology for productive commercial use. The most significant of these developments have been the:

• Identification and characterization of a set of solutes which may be used to create high osmotic pressures, a prerequisite for high rates of membrane water flux and high feed water recoveries; these solutes may also be efficiently removed from the product water and recycled for process reuse.

• Introduction of thin, highly selective semi-permeable membranes which enable high water flux in FO systems.

Together, these two developments, along with a number of other innovations, now show promise of enabling researchers to design, test, and demonstrate steady-state, scalable desalination systems based on osmotic, rather than hydraulic, pressure differences (McGinnis et al., 2007). The King Abdullah University of Science and Technology (KAUST) is currently investigating FO.

Knowledge Gaps/Future Advancements/Implementability Literature studies have shown that FO is a potentially viable low carbon footprint desalination alternative. In May 2010, Oasys Water Inc., in Massachusetts (USA), announced the commercialization of a high performance FO membrane as a next step toward the introduction of lower-cost desalination and water reuse technology. Unfortunately, in energy consumption estimates presented by Yale, thermal energy requirements were not included in the energy estimates presented in published literature. In reality, the energy associated with FO is low, although the energy associated with recovery of water from the spent draw



solution, or the reconstitution of draw solution, is potentially as high as with the desalination of seawater.

More recently, membrane manufacturer HTI Water, of Arizona (USA), launched large-scale commercialization of FO as a low-energy means of treating waste flows such as hydraulic fracturing fluids. Modern Water PLC has already established three installations using “manipulated osmosis” as a desalination process. Currently, the greatest barrier associated with FO is the lack of a cost-effective means of extracting water from spent draw solutions. The following advancements are needed for consideration of this technology in full-scale applications.

• Identifying effective and economical draw solutions and technologies/approaches that remove draw solutions economically (such as using waste/low-grade heat).

• Developing new and additional membrane sources. Currently, a limited number of commercially available membranes are on the market using cellulose triacetate.

• Addressing mass transfer limitations resulting from concentration polarization within the membrane support layer.

• Developing new modules suitable for full-scale implementation. To date, most applications have used flat-sheet, plate and frame elements.

FO can be applicable at small to large-scale systems in KSA for wastewater desalination, industrial wastewater treatment, and treatment and recovery of RO concentrate streams. Seawater is widely available and can be used as a draw solution for waste minimization in a number of instances. Although cost is not yet established, the unit capital investment cost of FO is expected to decrease as plant capacity increases.


Energy consumption using FO is estimated at one-quarter and one-third the energy consumption of multiple effect distillation and RO, respectively.

Technology Suppliers Oasys Water Inc. 21 Drydock Avenue, 7th Floor Boston, MA 02210, USA www.oasyswater.com

HTI Water Sales, Marketing and Corporate Headquarters 9311 E. Via De Ventura Scottsdale, Arizona 85258 888-420-7222 www.htiwater.com

Modern Water PLC Bramley House The Guildway Old Portsmouth Road Guildford, GU3 1LR United Kingdom Web: /www.modernwater.co.uk/

High Recovery RO Processes The major obstacle to operating an RO process at higher recoveries is the precipitation of sparingly soluble inorganic salts, most notably barium sulfate (BaSO4), calcium carbonate (CaCO3), calcium phosphate (Ca3(PO4)2), calcium sulfate (CaSO4) and silica. Inorganic salt precipitation can be controlled at lower recoveries by using an appropriate antiscalant and by

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acidifying feed water pH (effective for CaCO3 and (Ca3(PO4)2 control). At higher recoveries (greater than 85 percent), the concentration of sparingly soluble salts can exceed the effective range of antiscalants, and pH control does not prevent precipitation of some problematic minerals such as silica, BaSO4 and CaSO4 (that may not be as effectively removed by chemical cleaning). To improve RO recovery, one or more components of these scale-forming salts need to be lowered. High-recovery RO processes were developed to alter water chemistry prior to RO to allow higher water recoveries. These processes are applicable for treating RO/EDR concentrate streams with very high recoveries, in some cases approaching zero liquid discharge (ZLD). High-recovery RO/concentrate recovery processes include ARROWTM, SPARRO, and ZDDTM.

Advanced Reject Recovery of Water (ARROWTM) Application Area Industrial wastewater treatment, high silica and scaling potential brackish water, and wastewater and concentrate/brine treatment and water recovery applications.

Objective Increase RO recovery using patented softening system.


Description of the Technology ARROWTM is a high-recovery, advanced membrane system that couples a softening process with RO to increase water recovery. This is a proprietary technology marketed by Advanced Water Solutions and O’Brien & Gere. In RO and other desalination processes such as EDR, water recovery is limited by the concentration of scale precursors as well as by the concentration of colloidal and fouling material in the water. These compounds settle on the membrane surface or plates and reduce productivity. A common pretreatment to minimize scale fouling includes acidification of the feed water and addition of an anti-scalant. While calcium and magnesium hardness can be addressed by acidifying the feed water, acidification is ineffective for reducing sulfate hardness. Silica also has a limited solubility, and acid addition further reduces the solubility of silica. Increasing pH can push the solubility limit of silica, but it can result in deposition of calcium carbonate on the RO membrane surface or EDR plates.

ARROWTM has a number of configurations that can be adjusted depending on the flow rate, hardness, concentration of silica relative to other hardness precursors, and TDS concentration. The ARROW process is illustrated in Figure 2-7 and includes the following steps:

• Pretreatment - Dual media or membrane filtration is used to minimize colloidal fouling. A silt density of less than 4 is targeted. Also, pretreatment includes the addition of acid (if necessary) and anti-scalant.

• First-Stage RO - ARROWTM produces a permeate stream of 60 to 75 percent of the flow, while 40 to 25 percent of the stream is RO concentrate.

• Second-Stage RO - Concentrate from the first-stage RO is treated and combined with an appropriate flow of recycled stream from the second-stage RO concentrate.

• Softening of RO Concentrate Stream from Second-Stage RO - ARROW uses either chemical precipitation to reduce calcium, magnesium, and silica hardness or ion exchange (IX) softening containing strongly acidic cation exchange resins, if silica hardness is not a concern. Chemical precipitation uses caustic soda or soda ash depending upon the ratio of alkalinity to calcium hardness.

• Recovery - A small amount of flow from second–stage RO concentrate and a small reject stream from the bottom of the clarifier or from the IX system is sent to a solar evaporator or thermal crystallizer. The combined volume of the two reject streams is less than 5 percent, giving an overall process recovery of greater than 95 percent.



FIGURE 2-7 ARROW Process Schematic

Comparison to Established Technologies Potential Advantages over Established Technologies • High-quality product water compared to EDR, CD, or NF

• Applicable for treating high silica content streams (such as RO concentrate)

• High water recovery (90 percent according to the supplier ), which minimizes RO concentrate generation and disposal costs

• Compact skid-mounted system, which reduces not only footprint requirements but also equipment delivery and installation time (appropriate for applications less than 0.25 million gallons per day [mgd], or 95,000 cubic meters per day [m3/d])

Potential Disadvantages Compared to Established Technologies • Process is still under development; no full-scale applications exist in municipal water or

wastewater treatment

• High cost of chemicals used for pretreatment and softening of water

• Combining the RO reject and ion exchange regenerate would cause a precipitate to form that could reduce the crystallizer design and/or decrease on-line factor

• ARROW is a complex operation that requires skilled operators

• Pilot testing is required to determine key design criteria

• Sludge from precipitative softening might require separate disposal, creating additional challenge and expense

Technology Tested/ Demonstrated or Implemented No full-scale operation. To date, ARROW has only one demonstration project in the industrial water treatment field. This project is a 33-gallon-per-minute (gpm), or 7.2 m3/hr, unit in New Jersey, USA, as pictured in Figure 2-8.



FIGURE 2-8 New Jersey ARROW Project for Reject Recovery (Adapted from CH2MHILL, 2009) Knowledge Gaps/Future Advancements/Implementability Knowledge about the following has not been established: treatment efficiencies, economics (including sludge disposal and concentrate disposal costs), and long-term performance of the system.

Existing skid-mounted units, which are easy to implement, are applicable only to very small systems (up to 0.25 mgd, or 95,000 m3/d). Potential applications are currently limited to small industrial treatment and small brine/concentrate recovery applications.

Process performance and robustness under varying feed water quality conditions should be proven, and implementation costs should be comparable to those of other high recovery technologies for this technology to be considered for wider size and purpose applications.

Cost Information Not disclosed by supplier

Technology Suppliers Advanced Water Solutions 307 North Olive Street Ventura, California 93001 USA Phone: 805-641-3908 Fax: 805–641-3932 E-mail: [email protected] Web: www.advancedwaterinc.com

O’Brien & Gere 403 Main Street, #700 Buffalo, New York 14203-2100 USA Phone: 716-831-9923 Web: www.obg.com

OPUS Application Area Desalinate water/wastewater with high concentrations of sparingly soluble solutes, organics, and boron, including brine/concentrate streams.




Objective To achieve high recovery with high purity product water through the use of extensive pretreatment processes prior to RO.


Description of the Technology N.A. Water Systems, Veolia Water Solutions and Technology, France, designed the OPUS™ system. OPUS™ is a proprietary optimized pretreatment which incorporates unique separation processes for desalination of water with high concentrations of sparingly soluble solutes (e.g., silica, CaSO4, and Mg(OH)2), organics, and boron. The system is able to achieve high recovery with high purity product water through the use of extensive pretreatment processes prior to water being processed through IX and RO subsystems (RPSEA, 2009). A process schematic is shown in Figure 2-9.

FIGURE 2-9 OPUSTM Process Schematic (Courtesy of N.A. Water Systems) The first step of the process includes acidification and degasification of the raw feed water. This is followed by a conventional coagulation, flocculation, and high-rate plate settler sedimentation process, which is termed Multiflo™. After this step, the flow stream should be devoid of nearly all high-molecular-weight organic molecules and oxidized metals (particularly iron and manganese). Additionally, colloidal silica is partially removed by co-precipitation. Decant from the sedimentation basin is then filtered by a packed-bed media filtration column, which removes any microflocs and most suspended solids that pass through the plate settlers. The media filter may also achieve additional removal of low to medium molecular weight hydrophobic organic molecules, including oil and grease (Colorado School of Mines, 2009). Filtrate from the media filter is then processed through a mixed, packed-bed IX column for further water softening. A cartridge filter is then used to remove any IX resin or remaining particulate material prior to RO. The water is then pressurized and treated by brackish water RO (BWRO) membranes at an elevated pH. Operating the RO elements under these conditions reduces the fouling propensity of silica and increases the rejection of both silica and boron.

Comparison to Established Technologies Potential Advantages over Established Technologies • Could produce very high quality water (product literature reports greater than 99 percent

rejection of TDS and most multivalent solutes and achievement of additional silica and boron removal with high pH operation)



• Pretreatment reduces fouling and scaling precursors, resulting in much higher RO system recovery rates (e.g., 90 percent) compared to EDR, CDT, and conventional membrane-based systems for treating high-TDS water. Pretreatment also reduces feed pressure and energy requirements.

Potential Disadvantages Compared to Established Technologies • OPUSTM is still under development. Knowledge about the following has not been

established: treatment efficiencies of larger-scale installations, economics, and short- and long-term performance of the system.

• Despite the high water recoveries, OPUSTM generates multiple waste streams and a concentrate stream that needs to be disposed off or treated; sludge from the sedimentation basin requires dewatering and landfill application.

• Larger footprint than conventional RO or IX systems due to inclusion of pretreatment, chemical feed and storage, and dewatering facilities (if included).

• Complex operation. Requires skilled labor and sophisticated process automation.

• Multiple chemicals to handle, including acids, bases, hydrolyzing metal coagulants, and polymer-based coagulants.

• Available from only a single supplier and so does not allow for competitive bidding

Technology Tested/ Demonstrated or Implemented Currently, there are no full-scale applications. The OPUS™ was field tested at a steam-enhanced oil production field in San Ardo, California, USA. Field trials have demonstrated that this system can treat feed water with TDS levels up to 10,000 mg/L. Veolia Water Solutions Technologies claims that it could treat streams with TDS levels up to 30,000 mg/L.

The treatment process permeate quality is dependent on feed water salinity and operating conditions. However, product literature reports greater than 99 percent rejection of TDS and most multivalent solutes (Colorado School of Mines, 2009).

Knowledge Gaps/Future Advancements/Implementability The technology is still under development by Veolia. The technology has not been pilot-tested extensively and requires third-party independent evaluation to establish/prove the following:

• Life cycle costs of the treatment • Robustness of the process under varying feed water and operating conditions • Design and operating parameters to optimize process performance and to lower

chemical usage

Existing trailer-mounted systems (30,000 m3/day) can easily be brought to the project site and used for treating small systems. Potential applications are currently limited to small industrial treatment and small size brine/concentrate recovery applications.

Process performance and robustness under varying feed water quality conditions should be demonstrated. Project costs should be comparable to those of other high recovery technologies before this technology could be considered for mid- to large-scale applications.

Cost Information Cost information is not yet established.

Technology Suppliers N.A. Water Systems Airside Business Park 250 Airside Drive Moon Township, Pennsylvania 15108, USA Phone: 412-809-6000



Fax: 412.809.6075 Web: www.nawatersystems.com

Veolia Water Solutions & Technologies 401 Harrison Oaks Boulevard, Suite 100 Cary, North Carolina 27513, USA Phone: 919-677-8310 [email protected] Web: www.veoliawaterst

Slurry Precipitation and Reverse Osmosis (SPARRO)

Application Area Industrial wastewater treatment, treatment of high inorganic scaling potential brackish wastewater, and RO concentrate streams

Objective Increase RO recovery by reducing scaling precursors.


Description of the Technology SPARRO involves circulating a slurry of seed crystals within the RO system, which serve as preferential growth sites for calcium sulfate and other calcium salts and silicates. The scaling compounds are precipitated on the seed crystals instead of on the membrane. This process is confined to the use of tubular membranes due to the need to circulate the slurry within the membranes without plugging them (CH2M HILL, 2009). Process schematics of SPARRO are presented in Figures 2-10 and 2-11.

The water to be desalted is mixed with a stream of recycled concentrate containing the seed crystals and fed to the RO process. The concentrate with seed crystals is processed in a cyclone separator to separate the crystals, and the desired seed concentration is maintained in a reactor tank by controlling the rate of wasting the upflow and/or underflow streams from the separator. The combined recovery of the process is estimated to be greater than 90 percent (CH2M HILL, 2009).

Comparison to Established Technologies Potential Advantages over Established Technologies • Low energy requirement compared to RO and thermal/evaporative desalination

processes • Higher recoveries compared to EDR and RO, especially treating high scaling potential

waters (industrial, RO concentrate, etc.)


treatment efficiencies of larger-scale installations, economics, and short- and long-term performance of the system.

• Larger footprint; requires large reaction tanks and large area for membrane systems due to lower specific surface area of membranes

• Tubular membranes have lower TDS rejections (TOC and TN rejections may also be lower than with traditional RO membranes)

• Requires skilled operation

• Additional chemicals to handle

• Relatively complex operation

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FIGURE 2-10 SPARRO Process Schematic (Adapted from CH2M HILL, 2009)

FIGURE 2-11 Illustration of Tubular Membranes Used in SPARRO (Adapted from CH2M HILL, 2009)



Technology Tested/ Demonstrated or Implemented Currently there are no full-scale applications.

This technology has been tested at a pilot scale on several applications, including treating mining wastewater in South Africa, and treating primary and secondary RO concentrate streams from the Eastern Municipal Water District (EMWD), California, USA, zero liquid discharge (ZLD) pilot project. The combined recovery of the process was greater than 90 percent according to the study performed in South Africa (CH2M HILL, 2009). The results from the EMWD study indicate 70 to 80 percent recovery. Although this recovery seems moderate, it is in fact remarkably high considering the water quality matrix which prohibits use of RO/EDR without extensive pretreatment (softening and IX).

Energy requirements were estimated to be 18.2 kWh/kgal (0.77 kWh/barrel [bbl]). Capital costs are estimated to be $4.7/gpd ($199/barrel per day (bpd), while O&M costs are currently unknown (Colorado School of Mines, 2009).

Knowledge Gaps/Future Advancements/Implementability Knowledge about the following has not been established: treatment efficiencies, economics, and long-term performance of the system.

Process performance and robustness under varying feed water quality conditions should be proven and cost should be comparable to those of other high recovery technologies before this technology could be considered in mid- to large-scale applications.

Cost Information Reliable cost information is not yet established.

Technology Suppliers Unknown

Zero Discharge Desalination (ZDD™)

Application Area Industrial wastewater treatment, treatment of high inorganic scaling potential brackish wastewater, and RO concentrate streams

Objective Increase RO recovery by reducing scaling precursors.


Description of the Technology Zero Discharge Desalination (ZDD™), marketed by Veolia Water Solutions and Technology, France, was developed to reduce concentrate volumes generated from RO facilities.

In ZDD, the concentrate stream from a conventional RO system is fed to an electrodialysis metathesis (EDM) stack consisting of ion exchange membranes and thin solution compartments. A direct electric potential is applied to the ends of the stack, resulting in a direct current that is carried by ions migrating through the membranes and solution compartments. The DC potential pushes ions through membranes from a lower concentration to a more concentrated solution. Water flows tangentially to the membrane, while the flow of ions is perpendicular to the membrane (Biagini et al., 2010). An electrodialysis stack consists of anion membranes containing many fixed positive charges, usually quaternary amines, that are loosely associated with mobile negatively charged ions that permeate the membrane, and cation membranes with fixed negative charges, usually sulfonic acids, that allow positively charged ions to permeate. In the ZDD technology, the calcium salts that cause scaling in a



high recovery RO process are removed in an EDM process that is a variant of ordinary electrodialysis. The operating principles of ZDD are illustrated in Figure 2-12.

FIGURE 2-12 Operating Principles of ZDD The concentrate recovery mode of operation assumes that the RO concentrate from an existing RO system would be treated by the EDM process to produce highly concentrated salt streams while reducing the salt concentrations and the scaling tendency of this RO concentrate. If necessary, a silica removal system can be incorporated as a slip stream treatment, as presented in the process flow schematic shown in Figure 2-13. From an energy perspective, it is not practical to reduce the salt concentration to potable levels by the EDM process, so RO would be used to further reduce the TDS of the EDM treated water.

Comparison to Established Technologies Potential Advantages over Established Technologies • Potentially very high recovery (97 percent recovery, including dewatering) was reported

in Brackish Groundwater National Desalination Research Facility in Alamogordo, New Mexico (USA)

• Less waste to handle compared to IX-RO or lime softening-RO-based processes

• Requires less space than lime softening RO



FIGURE 2-13 ZDD™ Process Schematic (Courtesy of Veolia Water Solutions) Potential Disadvantages Compared to Established Technologies • ZDDTM is still under development. Knowledge about the following has not been


• Crystallization of sodium bicarbonate in a sodium chloride solution limits the possibility of increasing the water recovery in waters that contain substantial quantities of chloride and bicarbonate.

• Lower TDS removal than RO and mechanical/thermal processes. The process cannot remove uncharged molecules (such as boron, silica, and non-polar organic compounds) and requires additional treatment, if treated water is intended to be used in high quality reuse applications.

• As in other high recovery processes, a liquid waste stream is generated and needs to be disposed of properly.

Technology Tested/ Demonstrated or Implemented Currently there are no full-scale applications.

A large-scale pilot test was conducted at the Brackish Groundwater National Desalination Research Facility in Alamogordo, New Mexico, USA. The pilot testing results indicated that a recovery of 94 percent was achievable without dewatering (97 percent with dewatering). The cost projections performed by Veolia Water Systems indicated much lower capital and O&M costs compared to the lime softening-RO systems.

Knowledge Gaps/Future Advancements/Implementability The technology is still under development by Veolia. The technology has not been pilot-tested extensively and requires third-party independent evaluation to establish/prove the following:

• Life cycle costs of the treatment including solids disposal • Robustness of the process under varying feed water and operating conditions • Design and operating parameters to optimize process performance

Project costs should be comparable to those of other high recovery technologies before this technology could be considered for mid- to large-scale applications.



Cost Information The projected costs for a 94 percent recovery ZDD are as follow:

Installed equipment cost: $15.8 per kgal ($4.2 per m3) (does not include capital cost for treating/disposal of remaining 6 percent flow via final disposal methods (such as deep well injection, evaporation ponds)

O&M cost: $2 per kgal ($0.53 per m3) (does not include dewatering and waste disposal costs)

Technology Supplier Veolia Water Solutions & Technologies 401 Harrison Oaks Boulevard, Suite 100 Cary, North Carolina 27513, USA Phone: 919-677-8310 [email protected] Web: www.veoliawaterst

Humidification-Dehumidification Processes Humidification-dehumidification (HDH) desalination mimics the natural water cycle to desalinate the water. Normal atmospheric air is used as the medium to convert seawater to freshwater. HDH desalination involves two processes. Seawater is first converted to water vapor by evaporation into dry air in an evaporator (humidification). This water vapor is then condensed from the air in a condenser to produce freshwater (dehumidification). Heat for evaporation can be obtained from various sources, including solar, thermal, geothermal, and combinations of these. A simplified process schematic of HDH is presented in Figure 2-14.

FIGURE 2-14 Simplified Process Schematic of HDH (Adapted from Narayan et al., 2010) HDH systems can be classified under three broad categories. One is based on the form of energy used such as solar, thermal, geothermal, or hybrid systems. This classification highlights the most promising aspects of the HDH concept: the prospect of water production by use of low-grade energy, especially from renewable sources. The second classification

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of HDH processes is based on the cycle configuration (such as closed-water open air [CWOA]). The third classification of the HDH systems is based on the type of heating used: water- or air-heating systems.

Energy requirements of HDH include latent heat of vaporization, energy transport air, and cooling energy to condense the vapor. As a result, it is an energy-intensive process. Approximately, 650 KWh/ m3 of energy is required for vaporization, with additional energy required for mechanical equipment (Huehmer and Wang, 2009).

To enhance heat recovery, Muller and Holst have proposed the concept of multi-effect HDH. Figure 2-15 illustrates an example of this system. Air from the humidifier is extracted at various points and supplied to the dehumidifier at corresponding points. This enables continuous temperature stratification, resulting in a small temperature gap to keep the process running. This in turn results in a higher heat recovery from the dehumidifier. In fact, most of the energy needed for the humidification process is regained from the dehumidifier, lowering the energy demand to a reported value of 120 kWh/m3. This system is being commercially manufactured and marketed by a commercial water management company, Tinox GmbH.

FIGURE 2-15 Simplified Process Schematic of Multi Effect HDH (Adapted from Narayan et al., 2010) Variants of the HDH process include Dewvaporation developed in Arizona State University, USA and Diffusion Driven Desalination developed at the University of Florida, USA. Dewvaporation has been extensively investigated and is being commercialized by Altela, specifically for use in liquid waste concentration and treatment of produced water.



Dewvaporation Application Area Seawater, brackish water, and wastewater desalination. Recovery and treatment of concentrate streams.

Objective To lower the carbon footprint and O&M cost of the desalination facilities.

Status Innovative

Description of the Technology Dewvaporation uses a humidification-dehumidification cycle to produce distilled product water. Feed water is evaporated by heated air, and freshwater is condensed on the opposite side of a heat transfer wall, as illustrated in Figure 2-16.

FIGURE 2-16 Dewvaporation Process Schematic Each Dewvaporation tower contains a heat transfer wall made of plastic. The wall divides the module into two compartments, one for evaporation and one for dew formation. The



energy needed for evaporation is partially supplied by the recovered energy released during condensation. Heat sources can be combustible fuel, solar, or low-grade heat from various sources. Using waste heat or low-grade heat can reduce O&M costs significantly, thereby making it a very attractive desalination technology. The tower unit is built of thin plastic films to avoid corrosion and to minimize equipment costs. Tower construction is relatively inexpensive because the towers operate at atmospheric pressure.

The Dewvaporation concept was developed at Arizona State University, USA, in conjunction L'Eau LLC, the company that owns the patent rights to the process. The process has been marketed under license by Altela Inc. since mid-2006. Altela, Inc. has designed, manufactured, and tested several AltelaRainTM prototype systems based on the dewvaporation process. A schematic of the AltelaRainTM process is shown in Figure 2-17.

FIGURE 2-17 Altela Rain Dewvaporation System Comparison to Established Technologies Potential Advantages over Established Technologies • Can treat very high TDS-containing streams (up to 60,000 mg/L)

• Produces very high quality water (in one demonstration study, TDS was reduced from approximately 41,000 mg/L to 100 mg/L, resulting 97.5 percent salt rejection)

• Use of solar, waste heat, well-site gas significantly reduces operating cost.

• Operates in atmospheric pressure, so there are no requirements for high-pressure pumps and expensive sturdy towers



• Relatively high recovery (such as 90 percent, based on pilot tests conducted in New Mexico, USA) compared to NF/RO and EDR for treating high-TDS streams

• Less complex than mechanical/thermal evaporative processes.

• Water quality has little impact on process performance

• Plastic heat transfer walls reduce capital cost and eliminate corrosion concerns

• Less fouling/scaling propensity compared to NF/RO

• Silica does not limit the recovery compared to NF/RO

• No chemical usage for pretreatment of feed water

Potential Disadvantages Compared to Established Technologies • Dewvaporation is still under development. Knowledge about the following has not been


• Like other evaporative processes, the energy consumption of the dewvaporation system is high

• As in most desalination systems, post-treatment is required for stabilization and mineralization of the water


Technology Tested/ Demonstrated or Implemented A 5,000-gpd (~19 m3/day) Dewvaporation pilot plant was operated at the 23rd Avenue Wastewater Treatment Plant (WWTP) in Phoenix, Arizona, USA. The pilot plant feed was concentrate from a Tactical Water Purification System (TWPS) RO unit with ultrafiltration pretreatment. A 2,000-mg/L TDS wastewater RO concentrate stream was treated by the pilot plant to more than 45,000-mg/L TDS brine and 10 mg/L TDS distillate, yielding a recovery of up to 95 percent and salt rejection of more than 99 percent. Thermal multiple effects varied from 2.0 to 3.5, which was less than the 5.0 effects demonstrated prior to transport to the WWTP site. Using the average thermal multiple effect value of 3.2, and natural gas cost of $0.80 per therm, the operating cost of water would be $20.85 per kgal (764 kWh heat per kgal (Huehmer and Wang, 2009).

The use of waste heat or solar thermal reduced the operating cost to the cost of water pumping and air blowing (Beckman, 2008).

Three full-scale AltelaRain ARS-4000 systems were operated at natural gas wells in the San Juan basin near Farmington, New Mexico, USA (Colorado School of Mines, 2009). The ARS-4000 system processed approximately 4,000 gpd of produced water. The AltelaRainTM System produced distilled water with TDS of approximately 100 mg/L while processing a waste stream containing approximately 42,000 mg/L TDS. One unit reduced effluent disposal volumes by as much as 90 percent (Colorado School of Mines, 2009).

Knowledge Gaps/Future Advancements/Implementability Dewvaporation is still under development. Knowledge about the economics and long-term performance of the system has not been established. The following advancements would enhance the attractiveness of this technology:

• Effective recovery of heat of condensation • Development of inexpensive and efficient heat transfer walls

Demonstration project results are promising. Since use of Dewvaporation is especially favorable in arid areas, it will be suitable for many locations in KSA (Riyadh, Makkah, Al Madinah, etc.). Project locations where waste heat, low-grade heat, solar heat, or well site gas are available are the most favorable locations for implementation of this technology.



Like other evaporative processes, high energy-consumption might be a limiting factor for its applicability if no waste heat or renewable energy sources such as solar are available.

This technology has proven to be effective for producing high-quality water from high-TDS streams; it can be used for treating and recovering RO/EDR concentrate/reject streams.

Commercial units are already available and can be used in small applications. For large-scale applications, custom design is essential to reduce the capital investment.

Project locations where waste heat or low-grade heat is available (such as refineries) are favorable locations for implementation of this technology.

Cost Information The projected capital cost is in the range of $8,000 per 1,000 gpd for small plants, and $1,000 per 1,000 gpd for larger facilities. Operating costs for treating seawater and saline solutions vary from about $0.50 per kgal to $3.50 per kgal, based on waste heat and natural gas use as the heat source, respectively (USBR, 2008).

Technology Supplier Altela, Inc. 7500 Meridian Pl NW, Suite B Albuquerque, New Mexico 87121, USA Phone: 505-923-4140 Fax: 505-923-4130 E-mail: [email protected] Web: www.altelainc.com

Diffusion Driven Desalination (DDD) Application Area Seawater, brackish water, and wastewater desalination. Recovery and treatment of concentrate streams.

Objective To lower the carbon footprint and O&M cost of the desalination facilities.


Description of the Technology Researchers at the University of Florida, USA have patented an alternate desalination process that works using HDH principles. DDD is similar to the closed-air open-water HDH cycle, but it uses a direct contact dehumidifier in place of the non-contact heat exchanger normally used for condensation in the HDH systems. DDD uses a portion of the distilled water produced from the cycle as a coolant. A chiller is used to provide the distilled water at a low temperature. The specific energy demand or gained-output ratio (GOR) of the DDD process was estimated at 1.2, which is higher than for a normal HDH cycle in which the latent heat in the dehumidifier is not recovered.

This technology provides an efficient, environmentally responsible means of putting thermal energy discarded from existing processes to work producing freshwater. As in Dewvaporation, it can be constructed from inexpensive material because of the low temperature and pressure requirements.

Advantages and disadvantages of this technology are similar to those of the Dewvaporation. One major difference between the two is that DDD is not commercialized yet.

Hybrid Ion Exchange-Nanofiltration (HIX-NF) Desalination Process Application Area




Seawater, brackish water, and wastewater desalination applications.

Objective Reduce energy consumption and consequently the carbon footprint of the desalination facilities.


Description of the Technology Researchers at Lehigh University in the USA have been examining the use of a hybrid ion exchange-nanofiltration (HIX-NF) process for desalination of sea and brackish water. The researchers claim that the process can attain significant energy savings over the conventional membrane-based pressure-driven processes. In this hybrid process, illustrated in Figure 2-18, an ion exchange step converts monovalent chloride ions of saline water to divalent sulfate ions and the resulting solution, having a lower osmotic pressure than the feed, is desalinated using an NF membrane. The sulfate-rich reject stream from the NF process is used to regenerate the anion exchanger. Results confirm that NF membranes can desalinate sodium sulfate solution at a much lower operating pressure, compared to RO membranes, and can yield a higher permeate flux.

FIGURE 2-18 HIX-NF Process Schematic (Adapted from Huehmer and Wang, 2009) Comparison to Established Technologies Potential Advantages over Established Technologies • The NF membranes can desalinate sodium sulfate solution at a much lower operating

pressure compared to RO membranes and yield a higher permeate flux.

• Anion exchangers with different sizes of amine functional groups hold the promise that the process can be tailored for various levels of water quality.

Potential Disadvantages Compared to Established Technologies • The technology is still under development. Knowledge about the following has not been




• The low through-put prior to regeneration may result in engineering challenges for implementation.

• Energy consumption and system performance are unknown under typical recovery conditions (such as 40-50 percent).

• Poor permeate water quality compared to RO and evaporative/thermal desalination processes. Wastewater applications may require additional treatment for water reuse.

Technology Tested/ Demonstrated or Implemented Researchers at Lehigh University in the USA have been examining the use of HIX-NF for desalination of sea and brackish water. The HIX-NF process, as currently being studied, is using pure solutes to simulate seawater. Studies examining operation first with simulated seawater quality, and then with actual seawater, are required to evaluate the true efficacy. Researchers report energy consumption in the desalination process as low as 0.89 kWh/m3; however, the value is quoted for a process at 1 percent recovery, rather than the 40-50 percent typical in the industry, and is not representative of a full-scale installation (Huehmer and Wang, 2009).

Knowledge Gaps/Future Advancements/Implementability In order to achieve commercial success, several issues must be resolved by bench and field testing. Among the most crucial issues are the following:

• The sulfate-chloride selectivity of the anion exchangers plays an important role in the sustainability of the process. Laboratory studies reveal that a single type of anion exchanger cannot sustain the process for saline water with different salt concentrations. However, anion exchangers with different sizes of amine functional groups (e.g. quaternary-, tertiary-, secondary- and primary amine) show promise for the process to be tailored for different water quality.

• The low throughput prior to regeneration may result in engineering challenges for implementation.

Although it is more complex than NF/RO, this technology has similar space requirements (due to potentially increased water recovery as a result of softening). Utility requirements are similar to those of conventional NF/RO systems.

Cost Information Cost information is not yet established.

Technology Suppliers None

Membrane Desalination Cell (MDD) Application Area Wastewater desalination.

Objective Desalinate wastewater while generating electricity.


Description of the Technology The microbial desalination cell (MDC) includes a microbial fuel cell (MFC) that was modified by adding a desalination compartment in a middle chamber. The saline water is placed between an anion (AEM) and a cation exchange membrane (CEM). The AEM is placed next to the anode and the CEM next to the cathode. Naturally occurring bacteria are used on the anode; they grow using organic matter (acetate) and produce electrical current and release



protons into the water. Protons cannot move to the cathode because they cannot diffuse through the AEM, as only negatively charged ions can pass through this membrane. In order to maintain the charge balance, an anion (Cl–) flows from the middle desalination chamber to the anode. At the cathode, protons are removed from the water so sodium ions (Na+) in the desalination chamber move to the cathode chamber to balance the charge. As a consequence, sodium chloride salt (NaCl) in the middle chamber is removed; thus, water is desalinated as depicted in Figure 2-19.

FIGURE 2-19 Schematic of Air-Cathode MDCs (Adapted from Mehanna and Logan, 2010) Comparison to Established Technologies This technology represents a completely new era and cannot be compared with any established technologies. However, potential advantages of this technology are the following:

• Provides an added benefit of wastewater treatment and power generation, while achieving a noticeable degree of desalination without an external source of energy. The additional energy can be used within the wastewater treatment facility for pumping, driving electric motors, etc.



• Can be used for pretreatment in RO systems, which reduces energy requirements and may increase recovery of the system.

Technology Pilot Tested/Demonstrated or Implemented No full-scale facilities are in operation.

This technology has been bench-scale tested at Pennsylvania State University, USA, by Bruce Logan and co-workers. The results showed that the type of inocula used did not affect the performance of the MDC. Microbial community analysis of MDC’s anodic microbial populations by 16 S RNA clone library showed that the anode population was dominated by Geobacter sulfurreducens regardless of the type of initial inocula (Mehanna et al., 2010). This is not surprising since G. sulfurreducens is known to produce high current densities in bioelectrochemical systems. The bench-scale MFC achieved approximately 60 percent TDS removal.

Knowledge Gaps/Future Advancements/Implementability This is an embryonic but highly promising technology. Reducing TDS by 60 percent without using energy, in fact generating some, is a remarkable achievement. Although current TDS removal efficiency reported by Logan and co-workers is very low compared to established technologies, such removal may be enough to justify using MDC for desalting high-TDS KSA wastewaters for reuse applications.

Several advancements need to be made before this technology could be considered a viable option in full-scale applications. All MDC studies are conducted in batch mode at relatively small scales, usually less than 300 mL. A linear increase in the power density with an increase in MDC size is not expected due to the limitations of mass transfer. The high cost of platinum-coated cathodes limits the wide application of MDCs. Low-cost manganese dioxide (MnO2) cathode materials have been developed and tested in lab-scale MDCs operated at batch mode (Li et al., 2010). However, the performance of this new cathode is yet to be investigated in large-scale continuous MDCs.

Membrane Distillation (MD) Application Area Desalination of seawater, brackish water, and wastewater. Treatment and recovery of RO concentrate streams.

Objective Reduce desalination power cost combined with low-grade or waste heat.


Description of the Technology MD combines membrane technology and evaporation processing in a single unit. The appeal of MD is that it functions at atmospheric pressure and requires only relatively low feed temperatures of 70ºto 90ºC. MD transports water vapor through the pores of hydrophobic membranes using the temperature difference across the membrane. The membrane allows water vapor to penetrate the hydrophobic surface while repelling the liquid. The clean vapor is carried away from the membrane and condensed as pure water, either within the membrane package or in a separate condenser system.

MD differs from other membrane technologies in that the driving force that pushes the water through the membrane is not feed pressure but temperature. In MD units, vapor production is enhanced by heating the feed water, which increases the vapor pressure and penetration rate. MD requires the same amount of energy input to heat and condense vapor as traditional evaporation; however, it does not require boiling water and is operated at ambient pressure. The energy requirement for MD is lower than those of conventional evaporation



systems. MD is most efficient on low-grade or waste heat, such as industrial heat streams or even solar energy (Huehmer and Wang, 2009). Also, the efficiency of the unit can be improved with heat recovery.

MD membranes must be microporous (pore diameters of 0.05 to 0.2 micrometer [μm]) and nonwettable by the feed. Thermal and chemical resistance, narrow pore-size distribution, high porosity, and low thermal conductivity are other desirable membrane qualities. Membrane modules have been developed in various configurations, including plate-and-frame, spiral-wound, and hollow-fiber for MD applications.

A variety of arrangements and configurations can be used to induce the vapor through the membrane and to condense penetrant gas; however, the feed water must always be in direct contact with the membrane. Condensation is typically achieved via two major process configurations (Salamero, 2004):

• Direct-Contact Membrane Distillation: The cool condensing solution directly contacts the membrane and flows countercurrent to the raw water. This is the simplest configuration and is best suited for applications such as desalination and concentration of aqueous solutions (for example, juice concentrates).

• Air-Gap Membrane Distillation: An air gap is followed by a cool surface. The use of an air gap configuration allows larger temperature differences to be applied across the membrane, which can compensate in part for the greater transfer resistances. The air gap configuration is the most common and can be used for any application, including desalination.

A schematic illustration of an air gap MD is shown in Figure 2-20.

The thermal efficiency of MD declines with increasing salinity (TDS levels), because highly saline water requires a greater temperature drop across the air gap, leading to greater losses of heat conduction through the air gap. Similarly, as salinity is increased, lower fluxes can be achieved due to reduced heat transfer with highly saline water. The thermal efficiency and operating flux are estimated as a function of water salinity (Scott et al., 2007). Memstill, a patented MD technology of TNO Environment Energy and Process Innovation, Netherlands, is an innovative concept that combines high transport of water vapor and high transfer of evaporation heat into one membrane module. Because a Memstill module was designed to house a continuum of evaporation stages in an almost ideal countercurrent flow process, a very high recovery of evaporation heat is possible. The process was intended to decrease desalination costs to well below 0.50 €/m³, using low-grade waste steam or heat as the driving force (Huehmer and Wang, 2009).

Comparison to Established Technologies Potential Advantages over Established Technologies • Ability to utilize low-grade heat (solar collector, waste heat, etc.)

FIGURE 2-20 Schematic of Air Gap MD



• Less organic fouling propensity compared to RO

• Less pretreatment compared to conventional membrane desalination processes

• The only membrane process that can maintain process performance (such as water flux and solute rejection) almost independently of feed solution TDS concentration.

• MD membranes are more chemically inert and resistant to oxidation than traditional RO and NF membranes, which allows for more efficient, chemically aggressive cleaning

• Produces higher-quality water than NF/RO, EDR and CD.


treatment efficiencies of larger-scale installations, economics, short- and long-term performance, and fouling/scaling of MD.

• Requires special hydrophobic membranes. Existing commercially available RO membranes are not suitable for MD because such membranes have a relatively low product water flux, which can be attributed to severe internal concentration polarization in the porous support and fabric layers of RO membranes.

• Membrane modules for MD have not undergone extensive optimization and may require larger footprints than a pressure-driven system with equivalent capacity.

• Contamination of distillate occurs when the membrane fouls and wets the membrane pores.

• Use of multiple stages can reduce energy requirements but increases capital cost associated with membrane contactor.

Technology Pilot Tested/Demonstrated or Implemented A pilot test of MD using RO concentrate generated from a groundwater desalination facility operated by Eastern Municipal Water District (EMWD), California, USA was performed in 2009. The pilot test showed that the operating flux was between 1.2 and 2.4 gallons per square foot per day (gfd) at feed and permeate temperatures of 40 and 20 degrees Celsius (°C), respectively. Increasing feed temperature to 60°C increased flux to 6.0 gfd. The water recoveries were between 60 and 81 percent, with an average of 70 percent during pilot testing. The pilot MD exhibited excellent salt rejections (that is, 99 percent or greater) during pilot testing.

Knowledge Gaps/Future Advancements/Implementability No known full-scale application of MD. Pilot Memstill units are available for demonstration studies.

A 2010 desalination market survey completed by Global Water Intelligence (GWI) notes that “three areas of new technology are likely to be the focus of commercialization over the next four years.” MD was one of them. The market interest captured by the recent survey is a critical support for commercial success. The availability of low-grade or waste heat source or renewable energy is another important factor that favors implementation of MD in desalination projects.

Knowledge about the following has not been established: treatment efficiencies of larger-scale installations, economics, short- and long-term performance, and fouling/scaling of MD.

The following advances are required for commercial success:

• Development of micro-porous membranes that have the desired porosity, hydrophobicity, low thermal conductivity, and low potential for fouling.

• Development of membrane modules to reduce footprint.



As with many membrane technologies, MD systems are highly modular and can be applicable at small to large-scale facilities. Project locations where waste heat or low-grade heat is available (such as refineries) are favorable locations for implementation of this technology.

Cost The projected equipment cost is $3.34/gallons (or $880/m3), with O&M costs estimated to be $1.40/kgal (or $0.4 /m3)

Technology Suppliers TNO Environment, Energy and Process Innovation. Tel: +31 (0)55 549 3199 Fax: +31 (0)55 549 3410 Netherlands [email protected]

Memsys GmbH Zwingenbergstr, 90a 47802 Krefeld, Germany. Tel: +49 (0) 2151-3603127 Netherlands www.memsys.eu

Nanofiltration (NF) Application Area Desalination of brackish water and wastewater.

Objective To reduce operating pressure for energy savings and increase water recoveries.

Status Innovative

Description of the Technology NF is generally used as an alternative to lime softening for reducing the level of calcium and magnesium in hard water when TDS reduction is not typically a primary goal. The recent developments in the membrane field have made NF a candidate for TDS removal (such as 50 to 90 percent TDS removals were demonstrated). In addition, recent studies (Xu et al., 2005, Mansell et al., 2011, Bellona et al., 2011) have consistently shown that the degree to which NF membranes can remove most emerging contaminants is similar to that of RO membranes.

Comparison to Established Technologies Potential Advantages over Established Technologies • Lower energy requirements compared to RO • Higher water recoveries compared to RO • Less chemical addition for scale control compared to RO

Potential Disadvantages Compared to Established Technologies • Lower permeate quality than RO. Not very effective for removing monovalent ions, such

as sodium, chloride, and nitrate.

• Very poor nitrate removal. If nitrate or nitrogen removal is of interest, this technology alone may not be suitable.

• Rougher surface of NF membranes increases fouling tendency of the membranes, especially in reuse applications.




Technology Pilot Tested/Demonstrated or Implemented No full-scale facility in wastewater applications.

A commercially available NF membrane (NF 270, Dow Filmtec, USA) was pilot-tested at the Long Beach Water Reclamation Facility, Long Beach, California, USA in 2010. One key objective of the testing was to evaluate the efficacy of the NF and RO membranes for removing conventional and emerging pollutants. With the exception of nitrate (in this study nitrate removal was not required due to highly efficient upstream nitrogen removal practices), the NF membranes effectively removed TOC, TDS, and emerging contaminants. The emerging contaminant removals via NF were comparable to removals via RO. The study clearly indicated that NF was an equally efficient technology that can be used instead of RO in groundwater recharge projects. The study also projected an average energy savings of more than 50 percent with NF use.

Knowledge Gaps/Future Advancements/Implementability One major hurdle is to obtain regulatory approval for using NF in groundwater recharge projects. The consistent results obtained from independent studies and the database formed are encouraging factors that should warrant regulatory and public acceptance in near future. This technology is very mature. NF membranes, pressure vessels, pumps, and instrumentation and control (I&C) systems are widely and commercially available.

Cost The capital cost is very similar to those of conventional RO systems. O&M costs are lower due to reduced energy requirements.

Technology Suppliers Dow Water and Process Solutions 7600 Metro Boulevard Edina, MN 55439 USA Tel: 952-897-4311 Fax: 952-914-1009 Web: www.dow.com

Nitto Denko Corporate Headquarters 401 Jones Road Oceanside, CA 92058, USA Tel: +760-901-2500 Fax: +760-901-2578 [email protected]

Nanotechnology Applications Application Area Desalination of brackish water, seawater, and wastewater. Treatment and recovery of RO concentrate streams.

Objective To increase membrane fouling resistance, membrane permeability, and flux by impregnating nanomaterial or nanoparticles into thin film composite membranes.


Description of the Technology Over the last three decades, advanced water treatment processes have adapted the use of RO or NF membranes for salt removal. Thin-film composite polyamide membrane has been the dominant membrane used for RO and NF since its development. However, for

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desalination (including desalting of treated municipal wastewater), fouling and scaling of RO/NF membranes pose a major challenge to increasing process efficiency. When RO/NF processes are operated in the high-permeate recovery regime, the level of concentration polarization rises, thus increasing the propensity for membrane fouling. Membrane fouling can lead to a significant reduction in membrane performance (reduction in flux and salt rejection impairment) and shortening of membrane life. To minimize membrane fouling and improve membrane permeability and flux, development of nano-tubes and nanotechnology membranes recently began (Huehmer and Wang, 2009).

Researchers at Lawrence Livermore National Laboratory, USA, have been studying the use of membranes fabricated from carbon nano-tubes for desalination. The nanotubes, with diameters of approximately 2 nm, permit water transport while rejecting ions. The initial findings indicate liquid transfers several times greater than conventional seawater RO membranes. Advancements involving carbon nano-tubes may be applicable to RO, FO, MD, and other membrane technologies (Huehmer and Wang, 2009).

The membrane consists of super-hydrophilic nanoparticles dispersed in a conventional polyamide RO membrane by Dr. Eric Hoek and co-workers. These nano-composite membranes allow dramatically better water permeability than is possible with conventional RO membranes while maintaining highly comparable salt rejection.

A class of RO membranes with an active polyamide layer that is surface structured with terminally grafted polymer chains was developed to offer low fouling and mineral scaling propensity by University of California Los Angeles (USA) researchers (Lin et al., 2010). These membranes were synthesized by free-radical graft polymerization of either methacrylic acid (MAA) or acrylamide (AA) monomers onto the active polyamide layer of a base NF membrane, post-surface activation with an impinging atmospheric pressure plasma source, to yield nano-structured (SNS) RO membranes (SNS-PA-TFC). Gypsum scaling tests demonstrated that the SNS-PA-TFC membranes had significantly lower scaling propensity compared to an LFC1 membrane.

An example of a nanoparticle-impregnated RO membrane is illustrated in Figure 2-21.

Comparison to Established Technologies Potential Advantages over Established Technologies • Improved permeability and flux while maintaining comparable salt rejection (based on

bench-scale demonstrations)

• Uses same manufacturing process and same spiral-wound element as conventional RO systems


treatment efficiencies of larger-scale installations, economics, short- and long-term performance, and fouling/scaling of this technology.

Technology Pilot Tested/Demonstrated or Implemented No known full-scale application.



FIGURE 2-21 Schematic of Nanotechnologically Advanced RO Membrane (Courtesy of NanoH2O LCC, USA) The technology has been bench- and pilot-tested at Lawrence Livermore National Laboratory, USA, and the University of California Los Angeles, USA. The bench/pilot test results are presented in the ‘Description of Technology’ section; advanced thin film nanocomposite (TFN) membranes are currently marketed by NanoH2O LLC, USA.

Knowledge Gaps/Future Advancements/Implementability Finding a cost-effective solution to mitigate membrane fouling is of primary interest. Due to the earlier onset of thermodynamic restrictions, it is anticipated that engineering changes to RO plant design will be required to accommodate the membranes, including a reversion to two-stage design for seawater applications. If the added cost due to nano-technology inclusion remains within 5 percent of the capital investment as forecasted by NanoH2O LCC, full-scale demonstrations and implementations could likely occur in the near future. Implementation is very easy, considering that no additional upgrade is needed to the existing infrastructure. Scalability of this technology is identical to that of the NF/RO systems.

Cost Not established.

According to the NanoH2O, the added cost to the existing NF/RO is about 5 percent.

Technology Supplier NanoH2O, Inc. 750 Lairport Street El Segundo, CA, USA, 90245-5006 Phone: 424-218-4000 Fax: 424-218-4001 E-mail: [email protected] Web: www.nanoh2o.com

Silica Gel Based Adsorption Desalination (AD) Application Area Seawater, brackish water, and wastewater desalination. Treatment of concentrate streams.

Objective To reduce scaling and corrosion issues associated with thermal processes, lower the carbon footprint of desalination using solar energy, reduce waste heat, etc.



Status Innovative

Description of the Technology Silica gel based adsorption technology was developed in the National University of Singapore (NUS). Currently, NUS and KAUST are collaborating to optimize system performance and evaluate fouling/scaling behavior of the technology in a large demonstration unit (35 kW) using actual seawater. The technology uses adsorption/desorption cycles to desalinate seawater or brackish water without the need for chemical pretreatment.

The silica gel adsorption desalination and cooling unit comprises a host of stationary units, namely an evaporator, condenser, and adsorber/desorber beds. After de-aeration, saline or brackish water is fed intermittently into the evaporator where desalting is achieved at low system pressure (1–5 kiloPascals [kPa]) and temperatures (5-10oC), which mitigates problems associated with scaling and corrosion. During adsorption processes, water vapor is adsorbed by the silica gel due to its high affinity to water at low temperatures. Concomitantly, a heat source such as hot water (typically from 50 to 80oC) is supplied to the desorption beds, containing the saturated silica gel from the previous cycle, to expel the water vapor from the adsorbent. The desorbed vapor condenses on the cooler surfaces of the condenser, cooled by re-circulating coolant from a seawater cooling tower. Highly purified potable water is produced at low temperatures (50-80oC), enabling the technology to have a cooling application. The heat to drive desorption can be obtained from waste heat as well as renewable sources, including solar and geothermal. Figure 2-22 presents a process schematic of the process.

FIGURE 2-22 Schematic of Four-Bed Adsorption Desalination (Adapted from Wang and Ng, 2005)



Comparison to Established Technologies Potential Advantages over Established Technologies • Very low specific energy cost. (It is reported to be 1.38 kWh/m3, which is very close to

the lowest theoretical amount (1.0 kWh/m3) achieved by any desalination system (Thu et al., 2010)

• Cost-effective when a low temperature waste heat source is available

• Higher water recoveries than RO

• Capability to use solar energy results in great flexibility to locate the AD facilities

• Does not require pretreatment and post-treatment chemicals

• Low temperature operation minimizes scaling and corrosion problems

• Low maintenance requirement

• Silica is cheap and abundant in KSA

Potential Disadvantages Compared to Established Technologies • Requires large space • Availability of low temperature waste heat sources is important but finding these sources

may be a challenge for siting large-scale AD facilities

Technology Tested/Implemented or Demonstrated A four-bed small-scale demonstration unit has been successfully operated in Singapore for more than 6 years (Wang and Ng, 2005). Currently, Prof. Ng of NUS and Tawfiq Al-Ghasham of KAUST are co-investigating fouling/scaling behavior and optimizing operating parameters using actual seawater.

Knowledge Gaps/Future Advancements and Implementability The low electricity consumption and low O&M requirements are the two major attractive features of this technology. In addition, this technology can be retrofitted into an existing multi–effect distillation (MED) plant to increase efficiency of the system as reflected in the GOR value. This technology is potentially best suited to locations where there is a need for desalination, demand for cooling, and waste heat sources are available. The feasibility of this technology therefore depends on case-specific conditions. Use of tall silos can reduce the footprint but increases the capital cost of the facility.

Cost Information Thu et al. (2010) compared capital and O&M costs of AD and RO. They reported a total annualized cost of $0.46/m3 for AD and of $0.94/m3 for RO. Thu and co-workers assumed free waste heat in their estimation.

Technology Supplier Advon Singapore Pte Ltd. 20 Tuas Street, Singapore 638457 Tel: (65) 6349 2714 Fax: (65) 6863 8033 Email: [email protected] Website: www.advon.sg

Solar Desalination Application Area Seawater, brackish water, and wastewater desalination. Treatment of concentrate streams.

Objective Lower the carbon footprint of desalination using solar energy.

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Description of the Technology Among the energy sources that are suitable to drive desalination processes, solar energy is one of the most promising options, due to availability of solar radiation with water supply requirements in many locations. Among low capacity production systems, solar ponds represent the best alternative in cases with both low freshwater demand and low land price. For higher desalting capacities, it is necessary to choose conventional distillation plants coupled to a solar thermal system, which is known as indirect solar desalination (Garcıa–Rodrıguez and Gomez–Camacho, 2001).

Solar desalination uses thermal solar energy to evaporate and condense water as distillate. Distillation methods used in indirect solar desalination plants are multi–stage flash (MSF) and MED. An example process schematic of solar desalination is illustrated in Figure 2-23.

FIGURE 2-23 Schematic of Solar Desalination Concentrating solar power first creates heat. This heat can then be used either to generate electricity or directly to desalinate water. Properly configured, concentrating solar power can switch back and forth from creating electricity to water. RO can also be used for desalinating water if the generated energy via concentrated solar power is directed to the RO. As an alternative, the concentrated solar power, photovoltaic solar panel can also be used to generate energy to drive the desalination process. Figure 2-24 shows heat, power, and combined heat and power options for solar heat coupled with the MED and RO options.



FIGURE 2-24 Solar Desalination Options Given that concentrating solar power can create temperatures of 400-1,000+ degrees Celsius, the thermal energy can be used as a direct input to desalination as in the MED option (left on Figure 2-14).

There are four main technologies for concentrating solar power: parabolic troughs, solar dishes, solar towers, and compact linear fresnel reflectors. Of the four, parabolic troughs are the most widely used in plants operating in Spain and the USA (California and Nevada).

Solar thermal energy storage allows excess solar heat gathered during morning hours to be stored for use during afternoon electricity demand peak periods. Adding a combined cycle natural gas turbine provides redundancy and the ability to increase power production when needed, for instance on hot afternoons when grid demand spikes.

Comparison to Established Technologies The desalination aspect of this technology uses established technologies (such as RO, MED, and MSF). The only difference is that solar energy is used to drive the process in solar desalination.

Potential Advantages over Established Technologies • Use of solar energy reduces carbon footprint and GHG emissions.

• Free renewable source results in low O&M cost.

• Potential incentives and carbon credit may be available in the future, which makes it a more attractive solution.

• Solar intensity is high in KSA, which represents the highest potential among all renewable energy alternatives.

Potential Disadvantages Compared to Established Technologies • Initial cost of solar energy is high due to current manufacturing and installation practices • Requires large space • Solar panel requires high-quality water for cleaning



Technology TestedImplemented or Demonstrated A solar desalination demonstration plant provided by Solar Water Energy, USA, has been in operation in Ahmedabad, India since May 2008, producing pure distilled water from saline groundwater. The production capacity is approximately 27,000 gpd (100 m3/day).

A full-scale solar desalination facility (Acquasol 1) designed by Acquasol Infrastructure Ltd, Australia is being built near Port Augusta, Australia. It will include parabolic troughs concentrating solar power, combined cycle gas turbines, MED, and solar salt harvesting. The plant is being built by Acquasol Infrastructure Ltd, Australia.

King Abdulaziz City for Science and Technology (KACST), along with IBM, is building the world's largest solar-powered desalination plant in the city of Al-Khafji, KSA. The plant will use a new kind of concentrated solar photovoltaic (PV) technology and new water filtration technology. When completed at the end of 2012, the plant will produce 30,000 m3 of desalinated water per day to meet the needs of 100,000 people.

Another solar desalination demonstration unit is being installed at KAUST to produce distilled water from seawater.

Knowledge Gaps/Future Advancements and Implementability Desalination based on concentrating solar power offers affordable, sustainable, and recover wastewater and concentrate streams that are large enough to cope with the growing deficits in KSA. Several large demonstration projects in KSA, Australia, and Spain and extensive research in solar desalination technology strongly suggest that solar desalination technology will flourish in the next 5 to 10 years. Considering KSA’s high solar intensity year–round, solar desalination is a very favorable option. Data thus far show that solar desalination is more economical in mid- to large-scale facilities. Decentralized treatment plants that are desalting wastewater or centralized treatment facilities that are combining and treating brine/concentrate from multiple facilities will receive the most benefit from this technology.

The following advancements would further support this technology:

• The system efficiency is governed by preferably high heat and mass transfer during evaporation and condensation. The surfaces must be properly designed to improve heat transfer efficiency, economy, and reliability.

• The heat of condensation is valuable because it takes large amounts of solar energy to evaporate water and generate saturated, vapor-laden hot air. This energy is transferred to the surface of the condenser during condensation. This heat of condensation is ejected from the system as waste heat. The challenge is to achieve the optimum temperature difference between the solar-generated vapor and the seawater/wastewater-cooled condenser, to make maximum reuse of the energy of condensation, and to minimize the capital investment.

• Although the cost of concentrating solar power has been reduced in recent years, new manufacturing methods and material need to be developed to make this technology more affordable.

Most solar desalination components are mature (such as RO, MED systems, and supporting facilities) and commercially available around the world.

Cost Information Not available

Technology Supplier Solar Water Energy 12801 Auburn Street Detroit, Michigan, 48226, USA Tel: 313-544-7117



Fax: 313-544-7111 Email: [email protected] Website: www.solarwaterenergy.com

Innovative Disinfection/Advanced Oxidation Technologies A number of technologies have been developed in response to concerns associated with the use of chlorine (such as DBP formation) for wastewater disinfection, the need to improve disinfection and/or emerging contaminant removal efficiency. Although chlorine dioxide is established for drinking water treatment, it is not used for wastewater, largely because only limited benefits are provided relative to chlorine disinfection of wastewater and they do not justify the additional system complexity and expense. Bromine species are proven disinfectants, but may also react with organic materials to form unwanted trihalomethanes (THMs). Brominated organics formed during disinfection are often considered more harmful than the analogous chlorinated organics (Water Environment Federation [WEF], 2006). Therefore, chlorine dioxide and bromine-based disinfection technologies are not included in the innovative/developmental disinfection technology category in this chapter.

The technologies reviewed for this section include:

• Ferrate Disinfection and Oxidation • Microwave UV Disinfection • Pasteurization • Peracetic Acid • Photocatalysis • Simultaneous Use of Two or More Disinfectants • Solar Disinfection • Ultrasonic Cavitation

The established technologies (chlorination, chloramination, UV disinfection, ozone, hydrogen peroxide [H2O2] based ultraviolet advanced oxidation process [UV AOP] and ozone AOP) are not included in this chapter.

Ferrate Disinfection and Oxidation Application Area Water/wastewater treatment

Objective Disinfection, emerging contaminant removal, odor control, and waste stabilization


Description of the Technology Because of concerns over the effectiveness of disinfection processes and concerns related to the formation of DBPs, ongoing research is evaluating alternative disinfection methods. Ferrate (FeO4

2-) is an innovative technology that achieves disinfection and may produce less DBPs than chlorination.

The redox potential of ferrate is 2.2 v in acids and 0.7 v in bases, compared with redox potentials of 1.5V for hypochlorous acid, 1.4 v for chlorine gas, and 0.8 v for hypochlorite ions (Jiang and Lloyd, 2002). The protonated form, HFeO4-, is a stronger oxidant than the anionic FeO42-, and the acid dissociation constant (pKa) is 7.23 (Sharma et al., 2005).

Ferrate was explored in the 1970s as an alternative chemical for chlorine, but prior production methods made its use cost-prohibitive. With recent advances in new onsite production methods for ferrate, the ferrate cost has decreased, making it a potential alternative to the existing oxidation and disinfection processes. Ferrate is formed when ferric

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chloride reacts with sodium hydroxide (caustic) and sodium hypochlorite (bleach) in a precise combination of reaction time, mixing, and stoichiometry. Figure 2-25 illustrates the ferrate production process.

FIGURE 2-25 Schematic Illustration of Ferrate Production (Courtesy of Ferrate Treatment Technologies LCC) Ferrate is introduced into a water or wastewater stream as a liquid and can therefore be pumped, metered, and retrofitted in an existing treatment plant. The byproduct of ferrate oxidation is the ferric ion (Fe+3), which is an environmentally benign compound, but reacts with water to form the insoluble compound ferric hydroxide, which must be settled and removed.

The inactivation efficacy appears to be affected by ferrate dose, contact time, initial pathogen concentration, solids, pH, buffering capacity, water quality, and temperature; however, ferrate is affected less than chlorine by changes in organic content, pH, and temperature (WERF, 2008).

Comparison to Established Technologies Potential Advantages over Established Technologies • Potentially less DBP formation than chlorine-based disinfection

• Powerful oxidizing capability compared to chlorine-based disinfection

• Potentially requires lower contact time than chlorine-based disinfection, which reduces the required volume of the contact tank

• Relatively easy to retrofit into existing WWTPs

• May oxidize some emerging contaminants, although more research is needed.

Potential Disadvantages Compared to Established Technologies • No full-scale experience.



• Lack of concentration (C) and contact time (T) relationship in reuse applications. Ferrate has not been approved yet by the California Department of Public Health (CDPH) as an alternative disinfection technology for reuse applications.

• Lack of established cost data

• Must be generated onsite by mixing hazardous chemicals

• Decomposes and loses its strength

• Not a stronger oxidant than hypochlorite in water with basic pH

• Generates solids, which require proper disposal

• Compared to chlorine, additional chemicals (caustic and ferric chloride) to handle onsite

Technology Tested/ Demonstrated or Implemented Currently, there are no full-scale operating facilities. One full-scale facility is under construction in Mississippi, USA. Waite (1979) used a dose of 10 mg/L for 3.7-log inactivation of total coliform and 4-log inactivation of fecal coliform, while another study used a dose of 8 mg/L ferrate in secondary effluent for 3-log inactivation of total coliform, and 1.5-log inactivation of total bacteria (Jiang and Lloyd, 2002). In terms of relative resistance to ferrate, Escherichia coli, Salmonellatyphimurium, and Shigella flexneri showed similar susceptibility to ferrate, but Streptococcusfaecalis, Bacillus cereus, Streptococcus bovis, and Staphylococcus aureus were more resistant (WERF, 2008).

A bench study conducted by Srisawat et al. (2010) in the USA investigated oxidation capabilities of ferrate for reducing estrogenic activity in wastewater. The study showed that estrogenic activity was successfully reduced by ferrate oxidation. A 54 percent reduction in endocrine disrupting compounds (EDCs) was obtained when the optimum ferrate dose, 6 parts per million (ppm), was applied.

Knowledge Gaps/Future Advancements/Implementability Ferrate is an oxidizing agent that shows promise for disinfection, treatment of organics and metals, flocculation, and odor control. However, data available in literature are inconsistent regarding dose requirements, and not sufficient to develop minimum CT (ferrate concentration times contact time) requirements to inactivate a wider range of pathogenic organisms. In addition, it decomposes in solution (i. e., loses activity), and the traditionally high cost of buying or generating ferrate has limited its use. Recent advances may reduce chemical costs, which would facilitate its use, but more research is needed to develop dose and contact time, evaluate disinfection efficacies against a wider range of organisms, effects of wastewater quality on disinfection efficacy and dose requirements, performance and economics of onsite generation of ferrate, and potential for re-growth or DBP generation in wastewater.


Technology Supplier Ferrate Treatment Technologies LCC Orlando, Florida, USA Website: www.ferratetreatment.com

Microwave UV Disinfection Application Area Water/wastewater disinfection

Objective To improve UV lamp life and provide operational flexibility.



Status Innovative

Description of the Technology UV disinfection transfers electromagnetic energy from a mercury arc lamp to wastewater. UV lamps containing mercury vapor, which are charged by striking an electric arc, emit UV radiation. Conventional UV lamps contain electrodes that facilitate the generation of UV radiation. These electrodes are of delicate construction and their deterioration is one of the sources of failure in UV disinfection systems. Microwave UV disinfection technology eliminates the need for electrodes by using the microwave-powered electrodeless mercury UV lamp. In this technology, microwave energy is generated by magnetrons and directed through wave guides into the quartz lamp sleeves containing argon gas. Electrodeless lamps operate at higher pressures than traditional medium-pressure UV lamps, in the range of 5 to 20 atm, compared to 1 to 2 atm for traditional medium-pressure lamps.

Comparison to Established Technologies Potential Advantages over Established Technologies • Longer lamp life (3 years vs. 1 year)

• Greater design flexibility as a result of absence of electrodes

• No electrical connections in the water

• Radiation is produced through the entire length of the lamp and there is no energy loss associated with electrode

• Quartz sleeve remains the same temperature of the water, leading to less fouling

• Instant shut-off and quick restart capability

Potential Disadvantages Compared to Established Technologies • Knowledge about the following has not been established: optimized reactor hydraulics,

long-term performance, and cost.

• Has more components than the conventional electrode-using system, including magnetron, wave guides, and cooling fans

• Requires magnetron replacement each year, which could substantially increase O&M cost

Installations The MicroDynamics™ microwave UV technology provided by Severn Trent Services was installed at Kent County Regional Wastewater Treatment Facility (18-mgd or 68,000 m3/day peak flow design capacity), in Delaware, USA in October 2010.

Knowledge Gaps/Future Advancements/Implementability Knowledge about the following has not been established: capital and life cycle cost (including lamp and magnetron replacement costs and power draw) and long-term performance of the system. This knowledge gap needs to be closed for wider use of this technology in the future.

Cost Information Not disclosed by the supplier

Technology Supplier Severn Trent Services 3000 Advance Lane Colmar, PA 18915 Telephone: 215-997-4000 Fax: 215-997-4062



Email: [email protected] Web site: www.severntrentservices.com

Pasteurization Application Area Wastewater disinfection

Objective Reduce/eliminate formation of DBPs.

Status Innovative

Description of the Technology Thermal disinfection of liquids (water, milk, etc.) is termed ‘‘pasteurization’’ after L. Pasteur, who first articulated the fundamental microbial basis of infectious diseases. Pasteurization of water by boiling has long been practiced as a way of treating water contaminated with enteric pathogens. In fact, pasteurization can take place at much lower temperatures, depending on the time the water is held at the pasteurization temperature (Burch and Thomas, 1997). Pasteurization time decreases exponentially with increasing temperature. Above 50°C, time decreases at roughly a factor of 10 for every 10°C increase in pasteurization temperature. Viruses appear the hardest to kill and essentially set the boundary for acceptable time–temperature processes (Feachem et al., 1983). A typical process is 75°C for 10 min. The major advantage of pasteurization is that apparently all major pathogens of concern are killed, independent of wastewater quality; turbidity, pH, and other parameters influence the efficacy of other disinfection methods.

Pasteurization has never been considered as a water/wastewater disinfection method because of the high energy cost in heating large volumes of water. Recently, Pasteurization Technology Group, USA, developed an innovative pasteurization concept where disinfection may be achieved at a reduced cost. The reduced cost of pasteurization is based upon the capture of a waste heat source (such as turbine exhaust, solar heat, or cooling towers) and the transfer of that heat to the water for disinfection, as depicted in Figure 2-26. The main components of this process are commercially available and include a gas engine generator and a set of heat exchangers.

Comparison to Established Technologies Potential Advantages over Established Technologies • No chemicals to handle

• Generates no byproducts (such as DBPs)

• Effectively kills broad spectrum of pathogens including viruses (based on pilot study reported by Salveson et al., 2009)

• Compact due to very short contact time

• Availability of waste heat can further reduce the process cost

• Approved by CDPH for Title 22 reuse applications

Potential Disadvantages Compared to Established Technologies • No full-scale facility; still under development. Knowledge about the following has not

been established: economics and performance optimization.

• Maintenance is required to remove scaling on the heat exchangers. Hard water increases maintenance requirements



FIGURE 2-26 Schematic of Pasteurization (Courtesy of Pasteurization Technology Group) • Re-growth of microorganisms is possible, which requires maintaining residual chlorine in

the distribution system

• Air quality permitting may be a challenge for sensitive areas

• May require relatively large heat exchangers that increase capital and O&M costs

• Currently available from only a single supplier and so does not allow for competitive bidding

Technology Pilot Tested/Demonstrated or Implemented No full-scale facility. Pilot studies were conducted at the City of Santa Rosa’s Laguna WWTP, California (USA) for Title 22 approval. Conditional approval for reuse application was granted to the technology by CDPH on July 25, 2007. CDPH required that pasteurization temperatures of at least 180oF (82oC) be maintained continuously for a minimum of 10 seconds. This minimum temperature and contact time must be demonstrated to the Department, spanning a range of flow from the lowest to the highest flow, with two intermediate flow points. Following successful demonstration and approval, the technology was pilot-tested in three municipal WWTPs in California, USA. One demonstration-scale (0.5-mgd) facility is under construction in California to further evaluate the technology and develop an economic analysis. All these developments make this technology attractive.



Knowledge Gaps/Future Advancements/Implementability The currently available data on disinfection efficacy have been obtained from short-term bench-scale studies. More data are needed to better understand the effects of contact time, temperature, and water quality on disinfection, and to optimize contact time and temperature based on water quality and desired pathogen kills. Additional data on microbial re-growth and the resistance of various organisms (e.g., spores and thermophiles) to pasteurization will also help determine which organisms would serve as good indicators. More information is also needed on O&M requirements and costs.

Because relevant data on design and implementation are limited, any application of this technology should include pilot testing to determine the disinfection efficacy and system reliability under specific wastewater quality conditions. Approval from one or more local regulatory agencies may be needed depending on local requirements. Because the application of pasteurization to wastewater is relatively new, public acceptance is uncertain; however, CDPH approval, the public’s familiarity with milk pasteurization, and the lack of chemicals are likely to facilitate acceptance (WERF, 2008).

The technologies for pasteurization are fairly mature, so all the components (gas turbines, tanks, heat exchanger, etc.) are widely available around the world. If the economic analysis indicates implementation costs that are comparable to those of the established disinfection technologies, full-scale applications could be expected in the near future. The operating costs can be reduced if waste heat or digester gas can be used to drive the gas turbines (WERF, 2008).

Due to the relatively short contact time, this technology is expected to require less space than a chlorine contact chamber, which typically requires 90 minutes of contact time. However, to evaluate the footprint of the facility, the space requirements for other process components, such as the heat exchanger and waste heat recovery modules, need to be determined.

Cost Not established, although results from a recent study indicate that pasteurization may be cost-competitive with chlorination and UV disinfection (Salveson et al., 2009). However, extensive work needs to be done to confirm this, especially for medium and large plants.

Technology Supplier Pasteurization Technology Group 2995 Teagarden St. San Leandro, CA 94577, USA Phone: 510-357-0562 www.pastechgroup.com

Peracetic Acid (PAA) Application Area Wastewater disinfection Objective Reduce/eliminate formation of DBPs

Status Innovative

Description of the Technology As regulations become more stringent with respect to the use of chlorine as a disinfecting agent for municipal wastewater, municipalities have been looking for viable alternatives. One of the disinfecting agents that has attracted interest in recent years is peracetic acid (PAA). PAA (CH3CO3H) is a strong disinfectant with a wide spectrum of antimicrobial activity. It has been used in many industries including food processing, beverage, medical,



pharmaceutical, textile, and pulp and paper. Due to its bactericidal, fungicidal, and sporicidal effectiveness, as demonstrated in these industries, the use of PAA as a disinfectant for wastewater effluents has been investigated since the 1980s. Although PAA has been used for wastewater disinfection in Finland, Italy, and Brazil, it has not yet attracted much attention commercially around the world. It remains a new disinfection alternative in the North American and Middle East wastewater treatment markets (CH2M HILL, 2002).

PAA is a strong oxidant and disinfectant and its oxidation potential is greater than that of chlorine or chlorine dioxide. Commercially available PAA, also known as ethaneperoxoic acid or peroxyacetic acid, is available in a quaternary equilibrium mixture containing acetic acid, H2O2, PAA, and water, as shown with Equation 1 below (Metcalf and Eddy, 2007):

CH3CO2H + H2O2 ↔ CH3CO3H + H2O (1)

Where:

CH3CO2H = acetic acid CH3CO3H = peracetic acid H2O2 = hydrogen peroxide

PAA solution is produced from the reaction of acetic acid or acetic anhydride with H2O2 in the presence of sulfuric acid, which acts as a catalyst (Block, 1991). PAA combines the active oxygen characteristics of a peroxide within an acetic acid molecule. It is a clear, colorless liquid with no foaming capability. PAA belongs to the class of organic peroxides, which are man-made chemicals. Organic peroxides may contain peroxide radicals (oxygen-oxygen bond) that are a source of oxygen. The peroxide radical also promotes instability and combustion. Peroxides in general are high-energy-state compounds and, as such, can be considered thermodynamically unstable (Block, 1991).

Because of the disinfection power of the PAA mixture, PAA is a more potent antimicrobial agent than H2O2. Research studies have shown that H2O2 requires much larger doses than PAA for the same level of disinfection (Wagner et al., 2002)

Comparison to Established Technologies Potential Advantages over Established Technologies • Literature indicates that the infrastructure for chlorine disinfection can also typically be

used for PAA

• Broad spectrum of activity even in the presence of heterogeneous organic matter

• Produces few or no DBPs and persistent toxic or mutagenic residuals compared to chlorine-based disinfection

• May remove emerging contaminants

• Provides residual as in chlorine-based disinfection to protect distribution systems in reuse applications (WERF, 2008)

Potential Disadvantages Compared to Established Technologies • Five to 10 times more expensive than chlorine (CH2M HILL, 2002)

• Increases organic content of the treated water (BOD, COD, TOC, etc.)

• Does not kill or inactivate all pathogens and indicator organisms equally well; it is effective against coliform bacteria, but is weaker against viruses, and has little effect on spores and protozoa

• May have more stringent storage, transportation, and safety requirements than chlorine; bulk shipping of this product is not permitted by the Department of Transportation in the USA

• Potential microbial re-growth



Technology Pilot Tested/Demonstrated or Implemented No full-scale application of PAA in North America or the Middle East.

Studies conducted at the Montreal Urban Community WWTP showed that a dose of approximately 1 to 2 mg/L and 2-hour contact time might be able to achieve the 10,000 coliform forming units per milliliter (CFU/100 mL) fecal coliform target in the physico-chemically treated primary effluents (Colgan and Gehr, 2001).

In a bench-scale study, a PAA dose of 5 to 7 mg/L with a 60-minute contact time reduced the total coliform and fecal streptococci concentrations in secondary effluents to less than 1,000/100 mL and less than 100/100 mL, respectively (Lefevre et al., 1992).

• For secondary effluent, an approximately 5-mg/L PAA residual reduced total coliform and fecal coliform about 4 to 5 logs after 20 minutes of contact time (Morris, 1993). However, reduction was much lower for poliovirus (less than 1 log) under the same conditions.

• An approximately 4-log total coliform reduction was achieved with a PAA dose of 5 mg/L and 60 minutes of contact time for secondary effluents (Arturo-Schaan et al., 1996). However, although PAA disinfection effectively reduced the total coliform and E.coli strain concentrations, it did not reduce the percentage of E.coli strains containing plasmids.

Unlike the previous studies, to achieve a 2-CFU/100 mL total coliform in tertiary effluents for unrestricted reuse in agriculture, higher PAA doses (40 mg/L and 20 minutes of contact time) were required under cost-prohibitive conditions (Baldry and French, 1989). The PAA CT provided in this study (800 mg-min/L) is much higher than the CT required (450 mg-min/L) via free chlorination to meet all-purpose recycled water criteria for coliform enforced by CDPH. Such a high residual PAA dose would be cost-prohibitive while adding a significant amount of BOD/COD to the treated water.

Reductions of about 3-log for total and fecal coliforms and fecal streptococci were achieved using a 10-mg/L PAA dose with 10 minutes of contact time (Lazarova et al., 1998). Much higher doses or contact times were required for virus removals, especially highly resistant viruses such as F-specific bacteriophage MS2.

Knowledge Gaps/Future Advancements and Implementability The important parameters for determining the dose and contact time are not yet clear and there are few data on compliance history to establish the consistency of its performance.

More research is needed to determine whether re-growth or recovery of damaged cells is significant under field conditions.

Because relevant data on design and implementation are limited, any application of this technology should involve pilot tests to determine the disinfection efficacy and system reliability under specific wastewater quality conditions. Because there is no PAA use in full-scale wastewater disinfection, the extent of public acceptance is uncertain for use of PAA as a main disinfectant.

The O&M costs for PAA are currently high and consist entirely of the chemical costs (including transport). However, chemical costs may decrease if PAA use and the associated manufacturing capacity increase.

In addition to the high cost, this technology remains unattractive for disinfecting secondary and tertiary effluents because of concerns regarding the inability to activate viruses at reasonable CTs, the increased organic content in treated effluent, and uncertainty about public acceptance.

The space requirement depends on the CT value required and the residual PAA concentration at the end of the disinfection tank. Lower PAA doses are essential (requires proof-testing) for reducing O&M costs and the organic content of the treated water but



require longer contact times, which in turn increase capital cost and space requirements. For facilities that currently use chlorine, the capital costs for converting to PAA are expected to be minimal because both chemicals can utilize the same infrastructure (WERF, 2008). The technology is envisioned as modular, which should facilitate expansion.

Cost Capital costs are similar to those of chlorine-based disinfection systems. At a 4- to 14-mg/L PAA dose, the O&M cost was estimated to be 5 to 10 times that of chlorine, 4 times that of UV, and 1.5 times that of ozone (WERF, 2008).

Suppliers Food grade PAA is available from many suppliers located in the USA, India, China, Poland, and other countries.

Photocatalysis Application Area Water and wastewater treatment

Objective Disinfection and emerging contaminant removal


Description of the Technology Photocatalysts were first investigated for the treatment of refractory organics, and only more recently for disinfection (WERF, 2008). The catalyst most commonly used for disinfection is titanium dioxide (TiO2), which is activated by radiation in the UV light range (less than 385 nm). Researchers have also developed TiO2 catalysts that are activated by visible light, by doping the catalyst with small amounts of impurities (nitrogen, sulfur, etc.). The disinfection mechanism has been attributed to hydroxyl radicals, which damage cell membranes, cell walls, and internal structures (Gogniat et al., 2006; Wu et al., 2006a; Wu et al., 2006b; Yasui and Kamiko, 2005); these radicals form from the reactions of hydroxide and water, with the electron holes created when the photocatalyst absorbs radiation (Rincón et al., 2001).

The TiO2 technology is currently being tested at the laboratory scale, with research aimed

at increasing the rate of disinfection. As a result, no process information (design, implementation, O&M, cost) is yet available (WERF, 2008).

Comparison to Established Technologies Potential Advantages over Established Technologies • Elimination of chemical use compared to many disinfection technologies (chlorine,

ozone, PAA, etc.) • Removes recalcitrant compounds and emerging contaminants • Not sensitive to pH changes between 5 and 8

Potential Disadvantages Compared to Established Technologies • Similar to UV, photocatalysts are unlikely to be effective for treating wastewater with low

UV transmittance

• Still under development. Knowledge about the following has not been established: inactivation efficacy, design criteria (dose and time requirement), operation criteria on various pathogenic microorganisms under varying feed water quality conditions, and cost.

• Most catalysts that are currently available are too slow to be of practical use for wastewater treatment



• Catalyst can become deactivated in wastewater

• Re-growth of microorganisms is possible

• At low TiO2 doses (such as 0.25 mg/L), relatively high contact times (360 min for example) were required to achieve reasonable coliform inactivation

Technology Tested/Implemented or Demonstrated Photocatalytic disinfection has been tested in the laboratory using a variety of feed waters and with a number of organisms, including bacteria, bacterial and fungal spores, algae, and coliphage (WERF, 2008). The laboratory studies indicated that photocatalysis is usually effective for inactivating pure cultures of Enterococcus and gram negative bacteria, including coliform and E. coli; however, it performed poorly against a mixed culture in wastewater. Literature findings are not consistent regarding the re-growth potential of microorganisms following treatment. However, it appears that the longer the incubation time after treatment, the greater the potential for re-growth.

Knowledge Gaps/Future Advancements and Implementability Despite its attractive features (such as elimination of chemical disinfectants, and not being sensitive to pH changes in the typical wastewater treatment operating pH range (6.5-8.5), UV-photocatalysts are unlikely to be effective in low transmittance turbid waters and they are too slow to be of practical use for wastewater treatment (WERF, 2008). More importantly, knowledge about the following has not been established: inactivation efficacy, design criteria (dose and time requirement), operation criteria on various pathogenic microorganisms under varying feed water quality conditions, and cost. More work is needed to clearly establish the applicability of this technology to wastewater treatment.

Simultaneous Use of Two or More Disinfectants Application Area Water/wastewater treatment

Objective Disinfection, emerging contaminant removal

Status Innovative

Description of the Technology Extensive research is being conducted on sequential or simultaneous use of two or more disinfectants (chlorine/UV disinfection, ozone/UV disinfection, etc.) in water and wastewater treatment. Disinfection technologies use different disinfection mechanisms and their efficacies on different microbial species vary significantly. As a result, a multiple-disinfectant system may inactivate a larger spectrum of pathogens than a single disinfectant. For example, a combined UV/chlorine system could inactivate Cryptosporidium, which is resistant to chlorine and chloramines but is susceptible to UV irradiation, as well as adenovirus, which is resistant to UV but is susceptible to low doses of free chlorine. Most technologies used in sequential disinfection demonstrations/applications are proven technologies (such as chlorine, ozone, and UV disinfection).

Comparison to Single-Disinfectant Technologies Potential Advantages over Single-Disinfectant Systems • Multiple-disinfectant systems may inactivate a larger spectrum of pathogens than a

single disinfectant due to the wider spectrum of inactivation effects.

• May have synergistic effects on pathogen inactivation and contaminant oxidation. For example, ozone can improve UV transmittance of wastewater while the UV dose can be lowered, achieving the same degree of disinfection.



• Combining technologies can reduce the generation of specific DBPs. For example, the combined use of free and combined chlorine reduces the formation of THMs and N-nitrosodimethylamine (NDMA), compared to free chlorination (which increases THMs) or chloramination (which increases NDMA) alone.

• May reduce emerging contaminants (similar to ozone/UV).

• Multiple-disinfectant systems offer operational flexibility and improve plant reliability. For example, the existing infrastructure for chlorination can be used to control biofouling of filter media and UV equipment, to disinfect wet-weather flow, or as a backup for the UV system (WERF, 2008).

Potential Disadvantages Compared to Single-Disinfectant Systems • More complicated process control and operations

• Often more costly

• Knowledge regarding process design criteria and operating conditions is not well established.

• May require lengthy field testing for regulatory approval

• Material must be susceptible to two or more chemicals compared to one chemical in single-disinfectant systems

Technology Tested/Implemented or Demonstrated Numerous bench- and full-scale demonstrations were conducted using combined disinfectants. Table 2-1 summarizes effectiveness of combined disinfectants and processes for wastewater treatment.

Knowledge Gaps/Future Advancements and Implementability A recent trend has been to combine technologies to realize the benefits of each while minimizing the disadvantages. For example, the use of free chlorine and chloramines may reduce concentrations of DBPs. Implementation is fairly easy and highly cost-effective for facilities that currently use chlorine (WERF, 2008). Increased use of UV disinfection has prompted research on the combined use of UV with chlorine, ozone, PAA, and ultrasonic cavitation; each of these alternatives shows promise for improving the disinfection of wastewater, reducing DBPs, and/or decreasing the cost of disinfection (WERF, 2008). These technologies (with the exceptions of ultrasonic cavitation and PAA) are proven. One major hurdle for implementing multiple-disinfectant systems is to obtain regulatory approval: knowledge gaps regarding design and operating criteria remain. It is expected that this hurdle can be overcome with increased research efforts.

Solar Disinfection Application Area Water and wastewater treatment

Objective Using solar radiation to disinfect water/wastewater


Description of the Technology Solar radiation is an ancient disinfection practice previously used without an understanding of the mechanisms of the process. Solar disinfection technology uses solar radiation to inactivate pathogenic organisms in water and wastewater. The treatment involves filling clean and transparent containers with water or wastewater and exposing them to sunlight for several minutes. This is a low-cost and sustainable technology for treating small quantities of water.



TABLE 2-1 Effectiveness of Combined-Disinfectant Technologies

Combined Disinfectants Response Reference

Free Chlorine and Chloramination

Produced less NDMA than chloramination alone Reduced formation of halogenated DBPs compared to chlorine alone and reduced ammonia-N concentration in plant effluent compared to chloramines use alone

Schreiber and Mitch, 2005 WERF, 2008

H2O2 and Ozone No improved effectiveness Reduced disinfection efficacy of ozone Reduced formation of halogenated DBPs compared to ozone use alone

Lubello et al., 2002 Fenton, 2005

PAA and UV Disinfection

Improved effectiveness over use of PAA or UV alone Chen et al., 2005

PAA and Ozone Improved effectiveness over use of PAA or ozone alone Caretti and Lubello, 2005

PAA and H2O2 PAA and H2O2 had no effect, but addition of 1 mg/L copper had a dramatic effect

Metcalf and Eddy, 2003

Ultrasonic Cavitation and UV

Increased effectiveness over use of UV alone Metcalf and Eddy, 2003

UV and Chlorine Prevented biological growth on the UV equipment Much more effective than UV alone for inactivation of adenovirus. Reduced disinfectant doses required for adequate treatment and synergistic effects occurred. Reduced formation of THMs compared to chlorine use alone

WERF, 2008 Durance et al., 2005 Kinshella et al., 2007

UV and H2O2 High UV doses (such as >500 mJ/cm2) improved emerging contaminant removal efficiencies compared to UV alone No significant improvement in disinfection efficiency compared to high UV dose operation or H2O2 alone

Koivunen and Heinonen-Tanski, 2005

UV and Ozone Improved UV transmittance of wastewater and achieved same degree of disinfection with reduced UV dose. Reduced formation of halogenated DBPs compared to ozone use alone

Ried et al., 2004 Kinshella et al., 2007

Research studies have been conducted, starting in the early 1980s, to evaluate the extent to which sunlight can serve as a disinfectant for water and wastewater. Acra and co-workers at the American University of Beirut, Lebanon, showed that a 75-minute sunlight exposure achieved 3-log reduction (99.9 percent) of E. coli during field tests (Acra et al., 1984).

Portable, low-cost solar disinfection units to disinfect wastewater were designed and tested by researchers at the Department of Chemical Engineering at Lafayette College, Pennsylvania, USA. One unit was tested with both river water and partially treated water from two WWTPs. In less than 30 minutes in mid-day sunlight, the unit inactivated more than 4-log (99.99 percent) of bacteria contained in highly contaminated water samples (Caslake et al., 1992).



Wegelin et al. (1994) investigated the impact of solar disinfection on virus removal efficiencies. To achieve 3-log inactivation of Encephalomyocarditis virus (EMCV) a fluence (dose) of 34,000 kiloJoules per square meter (kJ/m2) was needed, which corresponded to a 12.5-hour mid-latitude mid-day sunlight exposure. Wegelin et al. (1994) also concluded that water temperature of 50oC considerably increased the bacteria inactivation rate, whereas the inactivation rate of viruses steadily increased within a temperature range of 20 to 50oC. Figure 2-27depicts the layout of the field experiments conducted by Wegelin and co-workers.

Comparison to Established Technologies Potential Advantages over Established Technologies • Simple and low carbon footprint

technology • Low maintenance requirements • Does not generate DBPs • May reduce photo-oxidizable compounds

Potential Disadvantages Compared to Established Technologies • Diurnal and annual variations in solar radiation flux density have significant impacts on

process performance. Requires back-up disinfection methods to improve reliability.

• Only one study with wastewater and the relationship between solar radiation intensity and contact time was not established.

• Wastewater quality (turbidity, color, surfactants, etc.) may significantly reduce process performance.

• Expected to require very large space to treat even small quantity of wastewater.

• No supplier of this technology even at demonstration scale. Design criteria and cost information have not been established.

Technology Tested/Implemented or Demonstrated No full-scale facility and only two bench/pilot studies: Wegelin et al., 1994 and Caslake et al., 1992.

Knowledge Gaps/Future Advancements and Implementability High solar radiation flux densities that occur in KSA may make it a potential disinfection option. However, additional field tests are necessary to evaluate the merits and efficiency of solar disinfection before serious consideration is given to this technology. In addition, large demonstration projects will be necessary to accurately determine project costs and to assess regulatory and public acceptance. Contingency measures need to be incorporated into implementation plans. Lack of design criteria, cost data, and other pertinent data contributes to uncertainty in regulatory and public acceptance. As a result, commercialization of this technology in the next 5 years is unlikely.

FIGURE 2-27 Layout of Field Experiments (Adapted from Wegelin et al., 2008)




Technology Suppliers Not available

Ultrasonic Cavitation Application Area Water and wastewater treatment disinfection

Objective To generate fewer DBPs


Description of the Technology Disinfection of microorganisms by cavitation is generally attributed to high temperatures, hydrodynamic forces, and chemical reactions (WERF, 2008). High temperatures cause pasteurization: denaturing of proteins, which kills or inactivates cells. Hydrodynamic forces include shear forces from micro-streaming and micro-jets, pressure gradients during bubble collapse, and stresses on cell walls and membranes from surface resonance induced by cavitation (Joyce et al., 2003). The combined effects of fluid shear, tensile stresses and hydroxyl radicals can lead to the inactivation of microorganisms.

Ultrasound is the most commonly used source of cavitation for disinfection, although hydrodynamic cavitation has also been tested for disinfection of recycled water in an industrial cooling tower (Gaines et al., 2006). For ultrasonic disinfection, the most important operational parameters appear to be power, exposure time, and radiation frequency. Typical power values are in the range of 50 to 500 watts per liter (W/L), with reported values between 10 and 1,500 W/L (WERF, 2008). Exposure times are generally in the range of seconds to hours. Ultrasound frequencies are defined as those greater than 20 kHz, the limit of human hearing. The term “power ultrasound” is sometimes used and refers to frequencies between 20 and 100 kHz, which appear to have the highest disinfection potential (Madge and Jensen, 2002), with the strongest hydrodynamic forces at low frequencies (Neis and Blume, 2003). At higher frequencies, disinfection efficacies decrease (Hua and Thompson, 2000; Joyce et al., 2003).

Comparison to Established Technologies Potential Advantages over Established Technologies • Requires relatively small footprint • Eliminates chemical use, which reduces DBP formation • Works more effectively in wastewater with higher solids contents (WERF, 2008)

Potential Disadvantages Compared to Established Technologies • Lack of full-scale operation. It has not been tested extensively, and knowledge about the

following has not been established: inactivation efficacy on various pathogenic microorganisms under varying feed water quality conditions, design criteria (ultrasonic dose and time requirement), operation criteria, and cost.

• Microbial re-growth following disinfection is possible

• Scalability and implementability of bench results on full-scale systems are uncertain

Technology Tested/Implemented or Demonstrated No full-scale facility. Neis and Blume (2002) bench tested 20-kHz ultrasound on secondary effluent. The test results showed that about 1 hr is required to achieve 2.9-log E. coli inactivation using an



average power of 400 W/L. In a laboratory study, Wong (2002) applied a 900-W/L dose for approximately 5 minutes to achieve more than 5-log E. coli inactivation.

Knowledge Gaps/Future Advancements and Implementability Ultrasonic cavitation has a unique advantage over chlorine-based disinfection technologies in terms of generating few DBPs. However, it has not been tested extensively, so there are significant knowledge gaps. For example, knowledge about the following has not been established: inactivation efficacy on various pathogenic microorganisms under varying feed water quality conditions, design criteria (ultrasonic dose and time requirement), operation criteria, and cost. In addition, the energy requirements to achieve significant disinfection appear to make it economically unfavorable, though this may change as the technology improves and knowledge gaps are narrowed in the future. It is unlikely that this technology will be seen in the marketplace in the next 5 years.

Cost Not established

Technology Suppliers None Comparison of innovative/disinfection technologies is provided in Table 2-2 of Section 2.4.

Other Technologies Ceramic Membranes Application Area Water and wastewater treatment

Objective Filtration of water/wastewater and removal or organics and phosphorus with chemical addition

Status Innovative

Description of the Technology Ceramic MF and UF membranes are made from oxides, nitrides, or carbides of metals such as aluminum, titanium, or zirconium (CH2M HILL, 2008). Typically, a tubular configuration is used with an inside-out flow path, where the feed water flows inside the membrane channels and permeates through the support structure to the outside of the module. Depending upon wastewater quality, coagulation is typically used for suspended solids removal. The system is operated in dead-end filtration (deposition) mode with a backwash interval of typically 3 hours. Chemically enhanced backwash uses chlorine and mineral acid or citric acid to remove organic and inorganic deposition. Figure 2-28 presents a process schematic of ceramic membranes

Ceramic membranes have been used in industrial water treatment for over 20 years. However, their high manufacturing cost has limited the extent of their use for water and wastewater treatment applications. Within the last 5 years, a less expensive ceramic MF product, manufactured by NGK of Japan, has emerged as a potential competitor to polymeric hollow fiber MF and UF systems, particularly for higher solids/turbidity, oil and grease, and more challenging applications. The use of ceramic membranes is increasing as more research and pilot studies are conducted. The capital cost of ceramic membranes will continue to decrease as they become more widely used.



FIGURE 2-28 Process Schematic of Ceramic Membrane Filtration (Courtesy of METAWATER Co., Ltd.) Ceramic membranes are much more resilient than polymeric membranes and are mechanically strong, chemically and thermally stable, and can achieve high flux rates. Research studies conducted on using ceramic membranes to treat oil-containing wastewater and produced have shown that ceramic membranes perform better than polymeric membranes on oil-containing waters (Faibish and Cohen, 2001; Gutierrez et al., 2008).

Ceramic membranes have a higher capital cost than polymeric membranes. The use of ceramic membranes is increasing as more research and pilot studies are conducted. The capital cost of ceramic membranes will continue to decrease as they become a more widely used technology. Ceramic membranes have been implemented at more than 70 facilities (nearly all in Japan). More recently, ceramic membranes have been coupled with powdered activated carbon (PAC) or titanium based UV advanced oxidation (UV+TiO2) to enhance organic and emerging contaminant removal in demonstration projects. For TiO2 based UV applications, ceramic membranes have been placed at the end of the process to recover un-reacted TiO2 slurry (Wade et al., 2008).

Comparison to Established Technologies Potential Advantages over Established Technologies • Mechanically strong, chemically and thermally more stable than polymeric

membranes, allowing operation in harsh wastewater quality conditions (extreme pH, temperature, presence of oxidants, etc.)

• Ability to handle higher solids loading based on more effective backwashing

• Perform better than polymeric membranes for treating high oil and grease containing wastewaters

• Much higher water recoveries (98-99 percent) than polymeric membranes (90-95 percent)

• Higher energy efficiency and longer membrane life, significantly reducing operating cost

• Can be coupled with ozone, other oxidants, or PAC to remove organic material



Potential Disadvantages Compared to Established Technologies • Ceramic membranes are still expensive • Ceramic membranes are heavy, which requires special housing and complicates

handling and installation • No track record outside of Japan

Technology Tested/Implemented or Demonstrated There are more than 70 full-scale applications of ceramic membranes in Japan (information obtained from Meta Water).

There is an increasing interest in ceramic membranes in reuse projects in the USA. Ceramic membranes received Title 22 approval by CDPH in 2007. A full-scale ceramic membrane project is underway at the Corralitos Creek Water Treatment Plant (9,460 m3/day) in Watsonville, California, USA.

Implementability/Future Advancements/Scalability Despite the recent reduction in ceramic membrane costs, one of the major challenges for implementing ceramic membranes is affordability. The capital cost of ceramic membranes is expected to decrease as they become a more widely used technology and manufacturing practices are improved. For wastewaters with high solids and organic content, ceramic membranes may be more suitable than polymeric membranes. Ceramic membranes may also preferable to polymeric membranes on projects requiring high recovery.

Mid-size to large projects may require pilot testing to evaluate system performance and develop capital and O&M costs.

Similar to polymeric membranes, this is a modular technology and can be applicable at small to large facilities.

Cost Equipment cost was estimated as $3,171,000 for 9,460 m3/day facility ($335/ m3) (Water Desalination Report, July 2009).

Annual O&M cost was estimated as $738,000 for treating 9,460 m3/day ($78 per year per m3) (Water Desalination Report, July 2009).

Technology Supplier METAWATER Co. Ltd. Shiyorama Trust Tower 4-3-1 Toranomon Minatu-ku Tokyo, Japan

CoMag Application Area Wastewater treatment

Objective To enhance phosphorus and suspended solids removal


Description of the Technology CoMag is a patented process of Cambridge Water Technology, Massachusetts, USA. It uses magnetite for ballasted flocculation, solids contact, and high-gradient magnetic separation to clarify wastewater and remove phosphorus. Metal salts are added to the wastewater and pH is adjusted. The wastewater is mixed with fine magnetic ballast to increase floc density and permit floc removal using a magnetic separator. The ballasted floc



settles rapidly in a small clarifier. Its magnetic properties allow the effluent to be further polished using a magnetic separator as depicted in the process schematic (Figure 2-29).

FIGURE 2-29 CoMag Process Schematic Comparison to Established Technologies Potential Advantages over Established Technologies • Smaller clarifier (magnetite is denser than sand, so it creates a heavy floc that can settle

rapidly in a small clarifier)

Potential Disadvantages Compared to Established Technologies • High-gradient magnetic separation has not been applied to wastewater treatment prior to

this technology development

• Lack of long-term performance and cost data

• Chemical phosphorus removal is limited by kinetic factors as well as stoichiometric factors, and excessive inorganic precipitant requirements need to be reduced to minimize sludge quantity

• Difficulty meeting turbidity requirements of recycled water without additional filtration step; additional filtration step reduces benefits of the technology and increases the capital and O&M cost of the facility

• Requires relatively skilled O&M personnel

• Only one provider of the technology

Technology Tested/ Demonstrated or Implemented No full-scale facility in operation.

This technology has been demonstrated at the City of Concord, Massachusetts (USEPA, 2008). No further information was available from Cambridge Water Technology regarding performance of the demonstration study and ongoing activities.

Knowledge Gaps/Future Advancements/Implementability Knowledge about treatment efficiencies of full-scale installations and economics has not been established.



This technology may be used in wastewater treatment projects requiring low phosphorus or metal discharges. It is a complex process and may have difficulty in reliably meeting reuse turbidity criteria without an additional filtration step. As a result of these limitations, it has very little application potential for reuse projects.

Cost Information Not disclosed by technology supplier.

Technology Supplier Cambridge Water Technology, Inc. Suite 3L, 810 Memorial Drive Cambridge, MA 02139, USA Phone: 617-871-1353 Fax: 617-871-1360 www.cambridgewatertech.com

Ecosphere Ozonix Application Area Pretreatment for RO, reuse of frac flow-back water

Objective To treat and reuse frac flow-back water in remote areas


Description of the Technology Ecosphere is an advanced oxidation system that is mounted on a semi truck trailer. The packaged system includes a large mesh particle filter for particle removal. Decanted feed water is pumped into a reaction vessel where ozone is mixed using a flash mixer. Dual frequency ultrasonic transducers initiate the conversion of ozone into hydroxyl radicals, which oxidize organic material and inactivate microorganisms. Aluminum sulfate is then dosed into water as a coagulant to assist removal of suspended material via activated carbon cartridge filter prior to RO (Colorado School of Mines, 2009). RO is used as a final step to remove soluble inorganic solutes. An example Ecosphere OzonixTM EF-60, 60-barrel-per-minute (2,500-gpm) pilot system is presented in Figure 2-30.

Comparison to Established Technologies Potential Advantages over Established Technologies • Produces very high quality water; the pilot study resulted in a reported 99.1 percent TDS

rejection and 97 percent removal of benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds

• Compact system

• High level of flexibility; easily adapts to highly varying water quality and quantity

• Comes with integrated pretreatment system

Potential Disadvantages Compared to Established Technologies • Technology is still under development. Knowledge about the following has not been

established: treatment efficiencies of larger-scale installations, economics, and short- and long-term performance of the system; reliability needs to be demonstrated through long-term operation

• Requires skilled O&M personnel



FIGURE 2-30 Ecosphere OzonixTM System (Courtesy of Ecosphere) • High energy consumption (52 kWh/kgal or 13.7 kWh/m3) compared to brackish and

seawater RO desalination energy consumption of 1.0-1.5 and 4 kWh/m3, respectively

• Ultrasonic transducers are expensive and require frequent replacement

• Low purified water recovery (for example, 75 percent, based on pilot test conducted in Oklahoma, USA) for treating high-TDS streams; supplier claims a 1 percent waste stream for disposal, with the rest of the solution being retained for reuse as frac water

• Generates precipitated solids which need to be disposed

• Requires addition of chemicals such as aluminum sulfate for coagulation


Technology Tested/ Demonstrated or Implemented No full-scale facility. A proof-of-concept pilot study was conducted with the OzonixTM system in the Woodford Shale Play in November of 2008. Newfield Exploration Mid-Continent, Inc., tested the process on frac flow-back water from a field near Coalgate, Oklahoma, USA. The frac flow-back water was characterized as having an influent TDS of 14,000 mg/L (dominated by chloride, sodium, and potassium), total hardness of 1,000 mg/L, total suspended solids (TSS) concentration of 65 mg/L, TOC concentration of 65 mg/L, total oil and grease concentration of 14 mg/L, barium concentration of 35 mg/L, and total BTEX concentration of 38 micrograms (μg)/L.

The system was housed in a large mobile trailer and was used to treat 100 barrels per hour (bph), or 16 m3 per hour (4,200 gallons per hour), of frac flow-back water for 12 to 14 hours per day for 2 weeks. A third party consultant group was hired to provide quality assurance and quality control for the study. A 220-kW electrical generator was used to power the system during field trials. Assuming a 13-hour workday, this equates to 2,860 kWh of energy consumed to treat 1,300 barrels (bbl), or 54.6 kgal (207 m3), of water. Based on these calculations, the specific energy consumption per bbl of water treated is 2.2 kWh/bbl (52 kWh/kgal or 13.7 kWh/m3) (Colorado School of Mines, 2009).

The pilot system achieved a reported 99.1 percent TDS rejection and 97 percent removal of BTEX compounds.

Knowledge Gaps/Future Advancements/Implementability The technology is still under development. Knowledge about the following has not been established: treatment efficiencies of larger-scale installations, economics, and short- and



long-term performance of the system; reliability needs to be demonstrated through long-term operation.

Although the capital and O&M costs were not disclosed by the supplier, both capital and O&M costs are expected to be high. In addition, operation requires relatively skilled O&M personnel and relatively extensive labor hours. These limitations make this technology unsuitable for wastewater treatment and reuse. One potential application area is the treatment of small quantities of frac flow-back water.

Cost Information Cost information was not disclosed by the supplier.

Technology Supplier Ecosphere Technologies, Inc. 3515 S.E. Lionel Terrace Stuart, Florida 34997 USA Web: www.ecospheretech.com

2.3.2 Biological Treatment Technologies Anaerobic Membrane Bioreactor (AnMBR) Application Area Wastewater treatment

Objective Reduce organic loading to the WWTP, reduce sludge generation, and potentially produce biogas and energy.


Description of the Technology Although the MBR is widely known for providing higher-quality effluent than CAS wastewater treatment technologies, it requires higher energy for operation, and routine maintenance has to be performed to manage membrane fouling. These two aspects represent the major opportunities within the biological membrane treatment technology area for development of innovative approaches. Development of low energy operation and more effective fouling strategies are currently being investigated (Prieto et al., 2010). In addition, conventional anaerobic biological treatment systems can effectively remove most of the organic contaminants present in wastewater; however, they are typically not as effective at removing residual levels of soluble and colloidal organic contaminants (Soubhagya et al., 2010).

One approach to reducing the energy requirements while producing reuse quality product water is to couple membrane technology with an anaerobic operating scheme. Anaerobic MBR (AnMBR) is similar to a conventional MBR facility except that the biological reactions occur under anaerobic conditions. As in conventional MBR systems, suspended solids are filtered through membranes for liquid-solids separation as depicted in Figure 2-31.

Different types of membranes (hollow fiber, tubular, flat sheet, etc.) and feed configurations (internal, external) can be selected. AnMBRs can be used for:

• Onsite wastewater treatment to reduce organic loading to the main treatment facility

• As a stand-alone technology to treat low- to mid-strength municipal wastewater

• To treat high-strength industrial wastewaters when coupled with another technology such as upflow anaerobic sludge blanket flowed by AnMBR

http://www.ecospheretech.com/



FIGURE 2-31 Simplified Process Schematic of AnMBR The AnMBR process recirculates biogas from the tank’s headspace through the diffusers located beneath the membrane units for mixing and scour needs, creating a sparging effect that scours the membrane surfaces and helps manage membrane fouling.

Comparison to Established Technologies Potential Advantages over Established Technologies • Potential for biogas generation and energy production quantities, depending on the feed

wastewater quality • Reduced waste sludge production due to low anaerobic yield, which reduces sludge

handling and disposal costs • Elimination of air supply needs for process and membrane scouring • Commercially available membranes and membrane technologies can be used

Potential Disadvantages Compared to Established Technologies • Knowledge about the following has not been established: performance, operating flux,

and effective fouling management for various membrane types and reactor configurations

• Bench-scale tests have shown much lower fluxes than conventional counterparts, requiring capital investment cost

• Gas production in low- to medium-strength wastewater was lower than the calculated values

• Significant fouling was reported Soubhagya et al. (2010)

• Operating temperatures of 35 to 37oC, which are higher than in conventional MBR operation, are required to increase gas production

Technology Tested/Implemented or Demonstrated There are 14 full-scale facilities in Japan, where wastewaters from food-processing facilities are treated using AnMBR.

In North America, one full-scale AnMBR facility has been operational since 2008 that uses Kubota’s flat sheet membranes and treats up to 420 m3/day of high-strength industrial wastewater from potato processing. ADI Systems Inc., Canada provides the services. According to Christian et al. (2010), the AnMBR system influent and effluent COD values were 34,000 and 225 mg/L, respectively. The system produces effluent with a TSS value of



less than 1 mg/L. An overall biogas methane yield of 0.32 m3 per kg COD removed was reported. The methane content of the biogas was reported to be 60 percent, which is similar to the content typically found in municipal anaerobic digester biogas. Christian et al. (2008) reported a fairly constant trans-membrane pressure (TMP) during several months of operation without chemical cleaning, indicating a low rate of membrane fouling in the full-scale system. Preceding the AnMBR units, the system includes treatment processes that provide oil and scum removal, screening, and partial removal of organics and solids. The AnMBR system was operated at flux levels less than 2 gfd.

Recent pilot studies did not yield very optimistic results in terms of flux selection and fouling control. Soubhagya et al. (2010) operated a pilot-scale submerged AnMBR system treating low- to mid-strength municipal wastewater. The permeate flux and TMP profiles indicated a sustainable permeate flux of 5 L/m2-hr (2.9 gfd), which was much lower than values observed in full-scale aerobic MBR systems (15 to 25 L/m2·hr).

Using a gas lift AnMBR, Prieto et al. (2010) showed that additional shear of gas lift did not improve operation flux. A stable flux of 12 L/m2·hr was obtained after a rapid initial flux decline. However, they concluded that further testing was needed over extended periods to evaluate the sustainability of the stable flux obtained in this study.

Implementability/Future Advancements/Scalability AnMBR is a membrane technology that may offer energy generation potential, reduce the need for aeration, and produce less sludge than aerobic processes. Operating conditions, fouling characteristics of sludge, and membrane management schemes must be evaluated to determine optimal operating conditions. Effective fouling control and flux maintenance strategies must also be developed. In addition, a full economic analysis must be performed before this technology can be widely implemented in municipal settings. As evidenced from the current applications, use of this technology with high-strength waste can offer greater benefits that can justify implementation of the technology in spite of the lower flux rates.

Gas production for energy would require implementation at a large plant to justify the capital investment for gas handling and co-generation facilities. WAS from decentralized facilities can be transferred to a centralized AnMBR facility to maximize biogas production for energy.

Cost Information Not established.

Technology Suppliers ADI Systems Inc. 1133 Regent Street, Suite 300 Fredericton, NB, E3B 3Z2 CANADA Phone: (+1)506.452.9000 begin_of_the_skype_highlighting Fax: (+1)506.452.7308 E-mail: [email protected]_of_the_skype_highlighting ww.adisystemsinc.com

Veolia Biothane AnMBR Veolia Water Solutions & Technologies 23563 W. Main St., Route 126 Plainfield, IL 60544 USA Phone: 815-609-2054 Fax: 815-609-0490

Anaerobic Migrating Blanket Reactor (AMBR) Application Area Wastewater treatment



Objective Reduce sludge generation and potential biogas generation


Description of the Technology The AMBR is a compartmentalized system where the flow of wastewater is reversed on a regular basis. In this process, the influent feed and the effluent withdrawal point are changed such that the sludge blanket remains uniform in the anaerobic reactor. This helps maintain the sludge in the system without the use of packing or settlers for solids capture (Argenent et al., 2001). A process schematic of AMBR is shown in Figure 2-32.

FIGURE 2-32 Simplified Process Schematic of AMBR (Adapted from Argenent et al., 2001) This technology has been applied outside of the USA to treat high soluble COD content wastewater in the food-processing industry to demonstrate high removal efficiency. One additional benefit of this system is that biogas can be generated in well designed and operated systems.

Comparison to Established Technologies Potential Advantages over Established Technologies • Potential for biogas generation and energy production

• Reduced waste sludge production due to low anaerobic yield, which reduces sludge handling and disposal costs

• Can perform at temperatures lower than mesophilic range (<35oC)

Potential Disadvantages Compared to Established Technologies • Lack of full-scale operation • Knowledge about the following has not been established: performance, cost, and

economies of scale • Mainly applicable to low solids and high strength soluble COD streams • Feasibility of gas production and energy generation has not been assessed

Technology Tested/Implemented or Demonstrated No full-scale or demonstration facilities. Only bench-tested in laboratory.

The bench-scale study treating medium-strength domestic wastewater showed 71 percent and 59 percent removal efficiency for soluble and total COD, respectively (Argenent et al., 2001). The COD removal efficiency reported in this study was much lower than removals typically achieved in CAS systems.



Implementability/Future Advancements/Scalability Despite some potential advantages (low sludge generation and potential gas production due to anaerobic operation), this technology has remained a laboratory-scale concept since it was first tested in 2000. Significant advancements need to be made before this technology can be considered as an alternative treatment option.



Membrane Aerated Biofilm Reactor (MABR) Application Area Wastewater treatment

Objective Reduce sludge generation and energy requirement


Description of the Technology Membrane Aerated Biofilm Reactors (MABRs) use a gas-permeable membrane for oxygen transfer to wastewater and, unlike conventional systems, do not use bubble aeration for aeration. The ability to control the contact time between air and wastewater enables high oxygen transfer efficiencies. The oxygen transfer at the membrane enables microbial colonization at the membrane surface. Oxygen transfer across the membrane increases due to microbial respiration. The biofilm formed on the membrane surface can promote nitrogen removal in a single reactor.

Comparison to Established Technologies Potential Advantages over Established Technologies • Lower energy requirements • Lower capital cost

Potential Disadvantages Compared to Established Technologies • Lack of full-scale operation

• Knowledge about the following has not been established: design parameters, short- and long-term performance, and cost

• High oxygen transfer efficiency was not proven during bench-scale evaluation (WERF, 2005)

• Expensive hydrophobic membranes are needed to improve gas transfer

Technology Tested/Implemented or Demonstrated No full-scale or demonstration facility.

A 1.5- m3 pilot-scale MABR capable of treating 1 to 2 gpm of municipal wastewater was designed, built, and installed at a Saint Paul, Minnesota (USA) municipal wastewater treatment facility. This bioreactor was tested over a 3-year period with three different sets of membrane modules. Each of the modules was tested to determine the effectiveness of gas transfer before being used to treat wastewater (WERF, 2005).

All membranes were found to transfer oxygen well in clean water, but once they were exposed to wastewater and biologically active conditions, they failed to perform as expected.



The microporous membranes provided by Celgard and Mitsubishi Rayon failed because the micropores became wet and lost their gas transfer capability.

The 3M membranes continued to transfer oxygen well but their fluorinated surface proved to be a poor substrate for biological attachment. As a result of massive biofilm sloughing, the nitrifying bacteria were unable to gain a foothold in the pilot study, resulting in poor nitrogen removal performance.

Use of multi-layered biofilm structures for denitrification with nitrification has been also demonstrated with MABRs, although full-scale application using a commercial technology has yet to be attained (Rittman, 2007).

Implementability/Future Advancements/Scalability The detailed evaluations (WERF, 2005) showed poor nitrogen removal and oxygen transfer efficiency. Significant advancements need to be made before this technology is considered as an alternative treatment option. Therefore, it is unlikely that this technology will be seen in the marketplace in next 5 to 10 years.



Membrane Biofilm Reactor (MBfR) Application Area Water, wastewater treatment

Objective Reduce energy cost, sludge generation, and carbon footprint


Description of the Technology The process reactor consists of a hollow-fiber membrane bundle with an inner and outer microporous layer and a nonporous layer sandwiched in between. Hydrogen-based MBfR introduces hydrogen inside and through the membrane fibers, which are sealed on one end to prevent escape. The hydrogen is allowed to diffuse through the nonporous layer. MABRs led to the development of the MBfRs by demonstrating that a substrate could be delivered directly to a biofilm using the membrane technology.

Autotrophic biofilm of indigenous organisms develops on the outside of the membrane. Autotrophic microorganisms use hydrogen as an electron donor to reduce oxidized compounds that are serving as electron acceptors (nitrite, nitrate, chromate, perchlorate, etc.).

This technology was developed and ground-breaking research was completed by Bruce Rittman and co-workers at Arizona State University, USA. The demonstration projects have shown that the technology is effective in treating water with contaminants such as perchlorate, nitrates, chlorinated solvents, selenate, bromate, chromate, and radionuclides. Researchers have also coupled an O2-based MBfR that nitrifies influent ammonia to nitrate with a H2-based MBfR for nitrogen removal in wastewater treatment (Rittman, 2007). A process schematic of MBfR is presented in Figure 2-33.



FIGURE 2-33 Process Schematic of MBfR (Adapted from Friese et al., 2008) Comparison to Established Technologies Potential Advantages over Established Technologies • Low sludge generation due to autotrophic growth

• More effective than CAS systems at removing oxidized forms of compounds (bromate, chromate, perchlorate, etc.)

• Smaller footprint than CAS systems

• Ability to couple different gaseous substrate-based MBfR systems in series for targeted removal of various contaminants

• Overdosing of carbon is problematic in post-denitrification systems because of the potential for increased BOD in effluent, whereas MBfR does not increase the organic content of the treated wastewater

Potential Disadvantages Compared to Established Technologies • Hydrogen concentration in liquid phase and mass transfer of hydrogen into the biomass

limit the system performance (WERF, 2005)

• Lack of effective biomass control

• Health and safety concerns regarding hydrogen handling

• Off-gas treatment may be required

• Excess hydrogen use may be encountered as reported in demonstration studies (Friese et al., 2008) with poorly designed systems

Technology Tested/Implemented or Demonstrated No full-scale facilities. Numerous pilot and demonstration projects performed in USA (mainly for groundwater nitrate and perchlorate treatment). One pilot project in Lake Arrowhead, California, USA, investigated performance of the MBfR for tertiary nitrate treatment. More than 90 percent removal of nitrate was reported. However, the major issues were the inability to control biomass growth and the need for a high level of hydrogen usage.

Implementability/Future Advancements/Scalability Extensive bench-scale experimentation over the past 10 years has proven that the hydrogen-based MBfR can transform one or several oxidized contaminants into harmless or easily



removed compounds. In order to achieve commercial success, however, a few issues must be resolved by bench and field testing. Among the most crucial issues are (Rittman, 2007):

• Understanding interactions with mixtures of oxidized contaminants • Treating waters with a high TDS concentration • improving design to achieve bubbles (gas transfer) • Developing modules that can be use in situ to augment pre-denitrification • Developing effective operating and cleaning strategies for biological fouling control • Establishing cleaning frequency and membrane module lifespan to accurately estimate

O&M cost

• Keeping the capital costs low

Based on the current interest in a low carbon footprint and low sludge generation treatment technologies, as well as extensive research efforts, it is expected that this technology could be commercialized within the next 5 years.



NEREDA Application Area Wastewater treatment

Objective Provide treatment with much more compact footprint and improve settling characteristics of activated sludge

Status Innovative

Description of the Technology The Nereda®, invented by Delft University, Netherlands, and commercialized by DHV, Netherlands, is based on cultivating aerobic bacteria in conditions that cause the bacteria to form an adhesive material that bonds the bacteria into concentrated “pellets.” The adhesive material and the conditions that produce it are not disclosed by DHV. Nereda’s claim is that the process of forming pellets allows large concentrations of bacteria to be contained in less space than in CAS systems, where bacteria are more dispersed and less concentrated. The pellets are also easier to settle in clarifiers because of their higher density. Bacteria in the pellets are as capable of decomposing the wastewater as dispersed bacteria in CAS; however, the advantages of higher concentrations and better settling may reduce the costs of aeration basins and clarifiers. The pellets may also be less prone to bulking and poor solids settling episodes.

Comparison to Established Technologies Potential Advantages over Established Technologies • All reactions take place in a single reactor. Eliminates need for additional clarifier • Improved settling rates • Compact (typically needs ¼ the space required by CAS system) • Potentially lower capital investment • Can be retrofitted into the existing sequencing batch reactor (SBR) systems to increase

capacity • Easy to operate



Potential Disadvantages Compared to Established Technologies • Available from only a single supplier and so does not allow for competitive bidding • Lack of independent evaluation of this technology • Lack of capital and O&M cost data

Technology Tested/Implemented or Demonstrated No full-scale installation in the world.

Currently DHV is replacing an existing system with a Nereda® plant, which will treat all wastewater produced in and around the town of Epe, Netherlands. This will result in a doubling of the plant’s treatment capacity without increasing its footprint. The upgraded plant will be in operation in mid-2011.

Implementability/Future Advancements/Scalability This technology is most suitable and economically justifiable for increasing the capacity of existing activated sludge systems without adding additional basins. It is the best fit for SBR systems where all biochemical reactions and solids-liquid separation of activated sludge take place in a single SBR.

All components (with the exception of the adhesive pellets) of this technology are mature and are available from multiple suppliers. The technology is expected to be used in small facilities initially. Once the benefits are proven in full-scale facilities, mid-sized to large facilities can use this technology.


Technology Supplier DHV Water BV P.O. Box 1132 3800 AL Amersfoort The Netherlands Telephone: 0031-33-468-22 00 Fax : 0031-33-468-28 01 Email: [email protected] Web: www.dhv.com

Multi-Stage Activated Biological Process (MSABPTM) Application Area Wastewater treatment

Objective Achieve BOD and nitrogen removal without solids wasting


Description of the Technology The Multi-Stage Activated Biological Process (MSABPTM) is a developmental technology for domestic and industrial wastewater treatment based upon spatial microorganism succession. Spatially segregated trophic microorganism chains provide proper conditions under which bacteria are used as a food source sequentially by first primary and then higher level microorganisms in the food chain. Apparently, the spatial microorganism succession provides treatment by aerobic and anaerobic microorganisms maintained at different stages of the biological reactor.




There are eight compartments in the biological reactor. The influent wastewater enters the first compartment and travels through each successive compartment, circulating via the flow pattern created by air diffusers located at the bottom of the tank. Wastewater flow is in a looping pattern so that short circuiting is reduced. Removal of organics and nitrification take place in the first four compartments. The fifth and sixth compartments are anoxic and denitrification occurs there. The seventh and eighth compartments operate in the endogenous phase in which the remaining volatile solids are digested. Each stage is supplied with an individually controlled air supply intended to sustain the microorganisms and promote optimum oxygen transfer. A proprietary inner carrier fabricated from synthetic material provides immobilization of microorganisms within each stage. Figure 2-34 shows a pilot unit provided by Aquarius Technologies, Inc.

FIGURE 2-34 Pilot MSABP(Courtesy of Aquarius Technologies) Comparison to Established Technologies Potential Advantages over Established Technologies • No primary and secondary clarifiers • Reduced capital cost • No WAS generation (according to the supplier) • Reduced energy cost • Lower carbon footprint

Potential Disadvantages Compared to Established Technologies • Lack of fundamental understanding for designing, sizing, and costing the system • Limited full-scale experience with limited performance data • Long-term performance is unknown

Technology Tested/Implemented or Demonstrated Three installations in the world: two industrial settings and one very small resort community (USA application).

Independent performance data were not obtained.

Implementability/Future Advancements/Scalability Implementation of this technology in a larger scale municipal application requires more demonstrations to explore process fundamentals, and long-term process performance is required to develop design criteria and establish cost. Once those benefits are demonstrated, it can be applicable at small to large facilities.




Technology Suppliers Aquarius Technologies, Inc. 1103 Mineral Springs Drive, Suite 300 Port Washington, WI 53074, USA Tel: 262-268-1500 Fax: 262-268-1515 Email: [email protected]

BioScape Technologies, Inc. 816 Bennett Avenue Medford, OR 97504, USA Tel: 541-858-5774 Fax: 541-858-2771 Email: [email protected]

Side Stream Treatment Technologies for Ammonia The centrate that results from dewatering the digested solids contains high concentrations of the released ammonia and represents a significant return load, up to 20 percent or 30 percent of the plant’s influent nitrogen load. Separate treatment of this side stream can significantly reduce the nitrogen return load to the main biological nitrogen removal process (CH2M HILL, 2010).

The increased use of anaerobic digestion, coupled with increasingly stringent ammonia nitrogen and total nitrogen limits in the effluent stream of municipal WWTPs, has led to extensive research on the treatment of the nitrogen-rich side stream. A number of innovative treatment approaches have been developed in recent years that specifically target these return flows, some of which are physico–chemical, others biologically based. It is the latter group of processes, which include nitritation and deammonification, which have attracted the most interest, due mainly to their potential cost-effectiveness, reduced energy requirements, and overall environmental benefits.

Single Reactor High-activity Ammonia Removal Over Nitrite (SHARON™) Application Area Wastewater treatment

Objective Biological nitrogen removal from streams containing high levels of ammonia (such as centrate and landfill leachate)

Status Innovative

Description of the Technology The SHARON™ process was developed cooperatively by the Delft University of Technology and Grontmij (De Bilt, Netherlands). Compared to conventional nitrification, the SHARON™ process reduces oxygen and COD requirements (for denitrification using supplemental carbon addition, etc.) by 25 percent and 40 percent, respectively.

The SHARON™ process features a continuous-flow, completely mixed reactor without solids retention. If the reactor is operated at an appropriate temperature (such as 30°C) and at a sufficiently low solids retention time (1-day aerobic SRT for example), then nitrite oxidizers can be effectively washed out of the system. With only ammonia oxidizing bacteria (AOB) present, the side stream ammonia is oxidized to nitrite. For the processes just described, alkalinity is typically insufficient to maintain a stable pH. Alkalinity can often be supplemented during the



denitrification step, which can be performed in the same reactor. As with some other side stream technologies (for nitrogen control), the carbon source used to perform denitrification is typically methanol. A process schematic of SHARON is presented in Figure 2-35.

FIGURE 2-35 Process Schematic of SHARONTM (Adapted from CH2M HILL, 2010) The aerobic oxidation of ammonia is an exothermic reaction (produces heat). When this heat is added to the centrate produced from dewatering anaerobically digested sludge, which can have temperatures above 90°F (32°C), the temperature in the reactor can increase. Therefore, a heat exchanger may be necessary to cool the reactor contents and maintain the optimal operating temperature of 30°C.

Considerable savings in carbon source and aeration capacity are reported when the SHARON process is compared to the conventional nitrogen conversion within the context of overall nitrogen removal. Based on European data, average nitrogen removal efficiency is in the range of 80 to 90 percent. On average, 70 percent of the nitrogen load is converted via nitrite. The presence of suspended solids is not reported to influence removal efficiencies and operation of the process, as it operates without solids retention.

Comparison to Established Technologies Potential Advantages over Conventional Nitrification/Denitrification Processes • Smaller side stream tankage requirements than conventional processes • Reduced oxygen requirement • Reduced need for external carbon addition • Relatively simple O&M • Presence of suspended solids

Potential Disadvantages Compared to Conventional Nitrification/Denitrification Processes • Nitrogen removal efficiency is strongly dependent on influent ammonia concentration and

hydraulic retention time (HRT)

• For KSA applications, temperature control would be required to maintain optimum operating temperature of 30oC

• Tight pH and alkalinity monitoring and control are required

Technology Tested/Implemented or Demonstrated



Six full-scale SHARON™ systems have been in operation for more than 5 years in the Netherlands. The only installation of SHARON™ in the USA that is currently in operation is at New York City’s Ward Island WWTP.

Implementability/Future Advancements/Scalability Significant research has been conducted for further improvement of the SHARON process. Most technologies are very similar to SHARON with some modifications.

The technology can be applicable at small to large facilities as in CAS systems. It is also suitable for treating centrate streams from the centralized anaerobic digestion facilities.

Technology Supplier Mixing and Mass Transfer Technologies Southeastern Region 8833 North Congress Ave., Suite 818 Kansas City, MO 64153, USA Tel: 816-854-1969 Email: [email protected] Website: http://www.m2ttech.com

STRASS Process Application Area Wastewater treatment

Objective Biological nitrogen removal from streams containing high levels of ammonia (such as centrate and landfill leachate).

Status Innovative

Description of the Technology The STRASS process, originally developed in Strass, Austria in the early 1990s (Wett, 1998), is being considered as an alternate to SHARON operation without bioaugmentation. The process uses a high sludge age SBR to oxidize ammonia to nitrite (nitritation), followed by reduction of the produced nitrite to nitrogen gas (denitritation). A supplemental carbon source, such as primary sludge or methanol, is used to drive the denitritation process.

The STRASS process is very similar to the SHARON process, and it was developed in the same year. The main difference is that the SHARON process is operated as a chemostat without solids retention (to keep a short SRT and thus maintain inhibition of nitrite oxidizing bacteria (NOBs), while the STRASS process is operated in an SBR with high sludge retention time (greater than 20 days). High sludge retention time in the reactor achieves a similar degree of denitrification at much reduced reactor volumes CH2M HILL, 2010). The key feature of the STRASS process is a simple and effective pH-based control mechanism to control the intermittent aeration system. Proper selection of pH setpoints helps to control NOB inhibition and inorganic carbon limitations.

The STRASS process is flexible and represents a viable alternative to the SHARON process if cost-effective treatment of the sludge dewatering centrate is the primary process objective. However, it does have additional processing requirements, including the need to use a pre-sedimentation process to remove solids from the centrate stream before side stream treatment.

Potential Advantages over SHARONTM • Improved denitrification performance due to maintaining high SRT. • Reduces tank volume requirement and capital investment



• Better process control • Primary sludge can be used for alternative carbon source for denitrification

Potential Disadvantages Compared to SHARONTM • Requires pre-sedimentation process to remove solids from the centrate stream prior to

side stream treatment

Technology Tested/Implemented or Demonstrated Full-scale STRASS systems are operating in Strass and Salzburg, Austria. Pilot systems are operating by the Alexandria Sanitation Authority, Virginia, USA. There are no full-scale installations in the USA at this time (USEPA, 2008).

Implementability/Future Advancements/Scalability Similar to SHARONTM, STRASS can be applicable for small to large facilities. It is also suitable for treating centrate streams from centralized anaerobic digestion facilities.

Technology Supplier Cyklar-Stulz CH-8737 Gommiswald Rietwiesstrasse 39 Switzerland Telephone: 41-55-290-11-41 Fax : 41-55-290-11-43 Email: [email protected] Web: www.cykar.com SHARONTM/ANOMMOX® (ANerobic AMMonia Oxidation) Process Application Area Wastewater treatment

Objective Biological nitrogen removal from streams containing high levels of ammonia (such as centrate and landfill leachate).

Status Innovative

Description of the Technology This process, which is a modification of the SHARONTM process, has two stages. In the first stage, the reactor is operated without supplemental alkalinity, resulting in the conversion of approximately half of the ammonia in the centrate to nitrite. The mixture of nitrite and ammonia is ideally suited to serve as influent for the ANAMMOX® process (second stage), where ammonium and nitrite are anaerobically converted to nitrogen gas and water as illustrated in Figure 2-36.

The ANAMMOX® reactor is typically operated at relatively high temperatures (25°C to 40°C). The ANAMMOX® reactor is similar in design to an upflow anaerobic sludge blanket (UASB).

Potential Advantages over SHARONTM and STRASS • More sustainable and lower carbon footprint than SHARON and STRASS due to

reduction in CO2 emission • Process does not require alkalinity and carbon addition • Eliminates chemical use, which reduces capital and O&M costs • Low sludge generation due to autotrophic denitrification




FIGURE 2-36 Process Schematic of SHARONTM /ANOMMOX® (Adapted from CH2M HILL, 2010) Potential Disadvantages Compared to SHARONTM and STRASS • More complex operation than single stage systems

• Tighter process control is required to maintain optimum ratio of nitrite to ammonium (1.3:1) in the first stage reactor

Technology Tested/Implemented or Demonstrated The first and only SHARON™/ANAMMOX® system in operation was installed at the Dokhaven WWTP (Waterboard Holland Delta, Rotterdam, Netherlands). The process began operation in 2005 (CH2M HILL, 2010).

No full-scale facility in the USA. Extensive research is being conducted in the USA and Europe.

Implementability/Future Advancements/Scalability SHARON™/ANAMMOX® can be applicable for small to large facilities. It is also suitable for treating centrate streams from the centralized anaerobic digestion facilities.

Technology Supplier Mixing and Mass Transfer Technologies Southeastern Region 8833 North Congress Ave., Suite 818 Kansas City, MO 64153, USA Tel: 816-854-1969 Email: [email protected] Website: http://www.m2ttech.com

DEamMONification (DEMON®) Process Application Area Wastewater treatment

Objective Biological nitrogen removal from streams containing high levels of ammonia (such as centrate and landfill leachate)

http://www.m2ttech.com/



Status Innovative

Description of the Technology The STRASS process has evolved into the DEMON™ process, which uses the same pH based control philosophy that was developed at the Strass WWTP. DEamMONication includes two autotrophic reaction steps: (1) partial nitritation (aerobic oxidation of about 50 percent of the ammonia to nitrite) controlled by maintaining a low-level bulk liquid dissolved oxygen (DO) concentration using pH; and (2) anaerobic oxidation of residual ammonia by generated nitrite. The DEMON process is operated in a single-sludge SBR system where intermittent aeration is provided. The reactor used in DEMON supports the development of higher-density granules which behave much like biofilms with respect to bacterial growth in different redox zones. These redox zones develop as a result of resistance to mass transfer, or diffusional limitations.

The DEMON™ processuses a cyclone to separate anammox bacteria, which exist inside the higher-density granules, from NOB. The selective wasting of NOB allows the optimized system to support relative quantities of NOB, AOB, and ANAMMOX bacteria that are required for the syntrophic relationship of the bacterium essential to support both partial nitritation and deammonification in a single-stage reactor. Figure 2-37 depicts a schematic representation of the DEMON™ process.

Potential Advantages over SHARONTM • More sustainable and lower carbon footprint than SHARON and STRASS due to

reduction in CO2 emission

• Process does not require alkalinity and organic carbon addition

• Eliminates chemical use, which reduces capital cost and O&M costs

• Low sludge generation due to autotrophic denitrification

• Patented control system provides stable process performance (90 percent ammonia removal) at varying influent loads

Potential Disadvantages Compared to SHARONTM • High-intensity tight process control is needed for success of operation

• Tall structure (20 m) due to inclusion of cyclone. May be a challenge to implement at locations with strict height limit

Technology Tested/Implemented or Demonstrated The DEMON™ process is being used in approximately 10 to 15 full-scale installations in Europe. The first full-scale SBR system in the USA that is capable of operating as the DEMON™ process is under construction at the time of preparation of this report at the Alexandria Sanitation Authority Water Resource Facility, Alexandria, Virginia, USA (Daigger et al., 2011).

Implementability/Future Advancements/Scalability

FIGURE 2-37 Process Schematic of DEMONTM (Adapted from CH2M HILL, 2010)



DEMON™ can be applicable for small to large facilities to treat streams containing high levels of ammonia. It is also suitable for treating centrate streams from centralized anaerobic digestion facilities.

Technology Suppliers Grontmij Nederland BV Infrastructure and Milieu Afdeling Water and Reststoffen Postbus 203, 3730 AE De Bilt Handelsregister 30029428, Netherlands Tel: 31-30-220-79-11 Fax: 31-30-220-01-74 Web site: http://www.grontmij.nl/site/nl-ni/

Cyklar-Stulz CH-8737 Gommiswald Rietwiesstrasse 39 Switzerland Telephone: 41-55-290-11-41 Fax : 41-55-290-11-43 Email: [email protected] Web: www.cykar.com

Vacuum Rotation Membrane (VRM®) System Application Area Wastewater treatment

Objective Filtration of biomass for high-quality effluent with smaller footprint, lower-energy demand, and more effective air scouring of membranes.

Status Innovative

Description of the Technology Vacuum Rotation Membrane (VRM), a patented process of Huber Technology Inc., USA, uses flatB-sheet ultra-filtration membranes rotating around a horizontal shaft. Scouring air is introduced next to the shaft at about half the water depth, providing high-intensity scouring of a small section in the 12 o’clock position. The membranes rotate through this scouring section several times per minute. Operating results show that neither back-pulsing nor regular cleaning is required to maintain an average flux of at least 10 gfd (35 L/m2/h) with a suction head of less than 10 feet (USEPA, 2008). Intermittent scouring at low throughputs minimizes energy cost. Figure 2-38 shows a process schematic of the Huber VRM.

Potential Advantages over Established Technologies • High concentration of biomass reduces aeration basin volume by 70 percent (according

to Huber)

• Reduced energy consumption for scouring air due to the centrally positioned air intake and rotation of the membranes

• No periodic permeate back-washing during filtration compared to many MBRs

http://www.grontmij.nl/site/nl-ni/




FIGURE 2-38 Process Schematic of Huber VRM Module (Courtesy of Huber Technology, Inc.) Potential Disadvantages Compared to Established Technologies • No full-scale experience in USA. • Lack of performance, operation, and cost data • Available from only a single supplier and so does not allow for competitive bidding

Comparison to Established Technologies Technology Tested/Implemented or Demonstrated One full-scale facility in Europe (location not provided)

The technology has been pilot tested in California, USA in 2006 for California Title 22 approval. The Huber VRM pilot system produced virtually particle-free effluent (<0.1 Nephelometric Turbidity Unit [NTU]) with more than 5-log removal of fecal coliforms and more than 3-log removal of coliphage. The operating flux was generally between 13 and 15 gfd with a TMP between 1.3 and 2.7 psi.

Implementability/Future Advancements/Scalability California Title 22 certification is the first step for demonstrating the ability of this technology to meet the most stringent water reuse criteria. As in other MBR systems, this modular technology can be applicable for small to large facilities.

Cost Information Equipment cost: $1 per gallon or $265 per m3 (based on European operations). O&M cost: $27 per year per m3 wastewater treated (based on overseas operations).



Technology Supplier Huber Technology Inc. Middle East P.O. Box 120136 Plot J2-08 Sharjah Airport International Free Zone United Arab Emirates Phone: (+971) 6.5574059 Fax: (+971) 6.5574069 E-mail: [email protected]_of_the_skype_highlighting www.huberme.com

2.3.3 Innovative/Developmental Resource Recovery Technologies Technologies classified under this category use physical/chemical and/or biological treatment principles to recover resources from wastewater in the form of nutrients, salt, biogas, and electricity. Most emerging technologies (carbon sequestration and biofuel synthesis, microbial fuel cell, etc.) in this category are not comparable with the established technologies because no matching technology can be found in the established category. Therefore, no comparison table is included in this sub-section.

Algae Sequestration with Biofuels Synthesis Application Area Wastewater treatment

Objective Reduction of GHG emissions and production of algae to produce biodiesel or crude oil


Description of the Technology The USA Department of Energy’s Office of Fuels Development funded a program to develop renewable transportation fuels from algae starting in 1978. The main focus of the program was the production of biodiesel from high lipid-content algae grown in ponds, utilizing waste CO2 from coal-fired power plants. Over the almost two decades of this program, tremendous advances have been made in the science of manipulating the metabolism of algae and the engineering of microalgae algae production systems. The microalgae family is a diverse group which can grow in autotrophically (uses inorganic material, such as CO2 as an electron donor to gain energy) or heterotrophically (uses organic carbon sources to gain energy). They use sunlight, nutrients, and carbon sources to produce new cells in aquatic environments. Algae have a relatively high lipid content, which makes them a valuable fuel source. Floatation, centrifuges, or membranes can be used for algae separation before harvesting them. Harvesting is a complex and energy-intensive process. Once harvesting is completed, biofuels can be produced by extracting the lipid fraction or grinding the cells to make a green crude oil using all the carbon in the cell. The production of biodiesel involves a process called “trans-esterification,” where the various triacylglycerols (oils) are chemically altered to form esters.

A simplified process schematic of algae biodiesel is presented in Figure 2-39.

The reactors (aquatic environment) used in algae biodiesel projects may be an open raceway or horizontal photo-bioreactors as presented in Figure 2-40.



FIGURE 2-39 Process Schematic of Algae Biodiesel (Adapted from CH2M HILL, 2007)

FIGURE 2-40 Algae Biodiesel Reactor Examples (Adapted from CH2M HILL, 2007) Comparison to Established Technologies (Corn, Cellulosic Materials, and Other Crops as an Alternative to Petroleum-Based Fuels) Potential Advantages over Established Technologies • High biomass productivity potential • Higher energy content fuel (microalgae fuel content is 100 times higher than corn) • Avoids competition with agricultural lands and water for food and feed production • Uses non-freshwater, resulting in reduced pressure on limited freshwater resources • Captures CO2 and recycles carbon for fuels and co-products • Still much smaller footprint compared to corn and cellulosic based alternative fuels • Much more suitable to the desert geography of KSA than crop-based energy

Potential Disadvantages Compared to Established Technologies • Still developmental technology. Knowledge about the following has not been

established: process design and optimization, efficacy of harvesting and conversion methods, and capital and O&M costs

• Consumptive loss of wastewater is a major issue. Photobioreactors do not have direct loss; However, the fluid in the tubes absorbs most of the solar radiation, so it must be cooled with an indirect heat exchanger with cooling water circulated to an evaporative cooling tower

• Harvesting and conversion methods are complex.

CO2 Source Reactors Initial Dewatering

Harvest Conversion to Biodiesel

- Compression- Transport- Purification- Dissolution

- Pumping- Horizontal & Vertical Designs- Tubes, Panels, and Bags- Open Raceway Pond- Temperature Control

- Flotation- Membranes- Centrifuge- Presses

- Complex- Energy Consumptive

- Standard Technology

Water Inoculum Nutrients Evaporation



• Yield per unit area is still low

Technology Tested/Implemented or Demonstrated No full-scale facility. Extensive pilot testing funded by the USA Department of Energy’s Office of Fuels Development has been performed since 1978. The pilot testing results have shown that algae can produce up to 7,000 gallons of oil per acre per year as opposed to 18 and 102 gallons of oil per acre per year produced by corn and sunflower, respectively.

Implementability/Future Advancements/Scalability A shift is occurring from an ethanol-centric biofuels strategy to a more holistic use of biomass within the entire energy sector. The global appetite for transportation fuel from green sources is intense. Generous funding in grants and venture funding is supporting algae to biofuel research. Algae are highly promoted as a method of sequestering CO2 from power plant flue gas, and facilities receive the added benefit of being paid CO2 credits. All these factors may make the algae to biofuel concept commercially successful in the near future. However, there are several questions that need to be answered first:

• What strains of algae will yield the ideal combination of high-quality effluent and high-quality biofuel?

• What are the most suitable reactor types and arrangements to avoid water losses and reduce facility footprint?

• What are the most efficient methods for separating and concentrating the algae?

• What are the most efficient and cost-effective methods for breaking open algae cells for the production of a green crude or the separation of the lipid, aqueous, and solid fractions of the lysed (broken open) cells?

• What are the most efficient and cost-effective methods for converting the green crude or purified lipid into a commercially reliable biofuel?

• To what extent are incentives or carbon credits available?


Technology Suppliers Not available

Carbon Sequestration with Biofuels Synthesis Application Area Wastewater treatment

Objective Reduction of GHG emissions and production of methanol from methane


Description of the Technology The developer of this innovative technology concept, Kartik Chandran, Ph.D., received the 2010 Paul L. Busch Award from The WERF Endowment for Innovation in Applied Water Quality Research for his research to develop a new technology that transforms plant-generated methane, a potent GHG, into the green fuel, methanol. The technology could offer WWTPs a more affordable, environmentally friendly process for producing this alternative fuel and help them address one of their top challenges, the reduction of nitrogen concentrations in effluents. The technology concept is depicted in Figure 2-41.



Comparison to Established Technologies No established technology.

Technology Tested/Implemented or Demonstrated Laboratory scale.

Implementability/Future Advancements/Scalability Ongoing research at Columbia University (Dr. Chandran) aims to develop a bioreactor system using the ammonia oxidizing bacteria to generate methanol. Early research focuses on process stability and methanol yield using different nitrifying bacterial strains. Some of today’s largest and most advanced treatment plants rely on methanol addition to improve the performance of their denitrification processes. For example, Blue Plains Wastewater Treatment Facility, which serves the metropolitan Washington, D.C. area, was able to decrease its nitrogen discharge by half using methanol addition. The cost of methanol addition, however, is significant and domestic methanol prices recently reached their highest levels in 3 years. By providing the technology for treatment plants to generate their own methanol, this bioreactor could provide smaller treatment plants with a more cost-effective option while still realizing the benefits of increased denitrification rates and improved nitrogen removal.

This approach is intriguing, because it relies on biological processes to address the methane and carbon dioxide in biogas. Biological nutrient removal has a proven track record in wastewater systems, even smaller ones. This process could easily fit into existing anaerobic treatment schemes and, in so doing, yield additional benefits. By integrating these bioreactors into the biological nutrient removal process, it would be possible to enhance nitrogen removal by converting nitrogen to nitrite using the ammonia oxidizing bacteria, and then channeling the methanol these bacteria produce back into the system to serve as an external carbon source for denitrification of the nitrite produced.

Cost Information Not established yet.

Current methanol production in the USA occurs largely through an expensive conversion process that chemically catalyzes the oxidation of methane gas. Adding to the cost is the need to purify methane sources, such as digester gas, prior to conversion. Columbia University research takes an alternative and more cost-effective approach to generating methanol through the development of autotrophic microbial reactors. These reactors, which plants can integrate into their normal biological treatment processes, convert the methane in digester gas directly to liquid methanol, avoiding purification and chemically catalyzed conversion.

Processes and technologies already exist to harness biogas as a resource. Cogeneration, which uses biogas to generate heat and power, is well established and is in use at WWTPs. But cogeneration, as with any resource recovery technology, has its drawbacks. For example, the cost of producing energy from biogas can be quite high relative to current energy prices, and the quantity of biogas required to make the process feasible often limits it to the largest treatment plants.

FIGURE 2-41 Schematic of (Courtesy of Columbia University, Dr. Chandran)



Technology Supplier Kartik Chandran, Ph.D. Department of Earth and Environmental Engineering Columbia University 918 Seeley W. Mudd Building 500 West 120 Street New York, NY 10027 Phone: (212) 854 9027 Fax: (212) 854 7081 [email protected]

Microbial Fuel Cell (MFC) Application Area Wastewater treatment

Objective Generate electricity during wastewater treatment


Description of the Technology MFC technology is an emerging biotechnology that utilizes bacteria to generate electricity during degradation of organic substances. Traditional MFCs consist of an anaerobic anode and an aerobic cathode. Bacteria degrade organic substances (e.g. acetate, glucose) and generate electrons in the anode chamber. At the cathode, the electrons are transferred toward a high-potential electron acceptor, preferably oxygen. As current flows over a potential difference, electricity is generated as a result of bacterial activity. The generation of electricity is based on the respiratory enzymes of the bacteria that span the outer membrane and transfer electrons to materials on the surface of the cell. MFC represents a great potential for its application in WWTPs to simultaneously treat wastewater and produce electricity (USEPA, 2008). Figure 2-42 presents a schematic of an MFC.

Comparison to Established Technologies No comparison to any established technology.

Technology Tested/Implemented or Demonstrated MFC, originally developed by Bruce Logan at Pennsylvania State University, Pennsylvania, USA, has been investigated by numerous researches over the last 5 years. The highest power density reported reached over 1000 W/ m3 (Fan et al., 2007). Diverse MFC

FIGURE 2-42 Schematic Illustration of Microbial Fuel Cell




configurations (He et al., 2006), electrode materials (Logan et al., 2007), and substrates (Galvez et al., 2009; Freguia et al., 2010; Kim et al., 2010) have been studied and promising results have been reported.

Implementability/Future Advancements/Scalability Application of MFC on a broader scale is still limited by several obstacles. First, most MFC studies are conducted in batch mode at relatively small scales, usually less than 300 mL. A linear increase in the power density with an increase in MFC size is not expected due to the limitations of mass transfer. Although a higher number of electrodes (as high as four) in MFCs has been found to maintain the power density of MFCs at large scales (Jiang et al., submitted), it remains unclear whether further increases in the number of electrodes can improve the power generation of MFCs operated in continuous flow mode. Second, the high cost of MFC, especially the high cost of platinum-coated cathodes, limits the wide application of MFCs. Low-cost manganese dioxide (MnO2) cathode materials have been developed and tested using laboratory scale MFCs operated in batch mode (Li et al., 2010). However, the performance of this new cathode is yet to be investigated in large-scale continuous MFCs.


Technology Suppliers Not established

2.3.4 Innovative/Developmental Phosphorus and Salt Recovery Technologies Crystalactor® Technology Application Area Wastewater treatment

Objective Reduce phosphorus loads to WWTPs and recover phosphorus

Status Innovative

Description of the Technology The Crystalactor® process was developed by DHV Water BV, Netherlands, and is an example of crystallization processes for phosphorus recovery. The technology uses sand as the seed material for crystal development in a vertical cylindrical fluidized bed reactor which combines coagulation, flocculation, separation, and dewatering in a single reactor. The phosphate-containing wastewater is pumped upward, maintaining the pellet bed in a fluidized state. In order to crystallize the phosphate on the pellet bed, a driving force is created by a reagent dosage and sometimes also pH adjustment. Once the appropriate process conditions are selected, co-crystallization of impurities is minimized and high-purity phosphate crystals are obtained. The pellets grow and move toward the reactor bottom. At regular intervals, a quantity of the largest fluidized pellets is discharged at full operation from the reactor and fresh seed material is added after atmospheric drying pellets are obtained. A schematic diagram of the process is shown in Figure 2-43.

The Crystalactor® process enables phosphate removal and recovery by means of several process routes:

1. crystallization as calcium phosphate 2. crystallization as magnesium phosphate 3. crystallization as magnesium ammonium phosphate 4. crystallization as potassium magnesium phosphate




Technology Tested/Implemented or Demonstrated This technology has been applied at full-scale in the Netherlands and was installed at the Geestmertambacht, Heemsted, and Westerbrork plants. In 1994, the Crystalactor® reactor was installed in the Geestmertambacht plant to recover phosphorus as calcium phosphate, which could be used as raw material in the phosphate industry to produce phosphoric acid. The capacity of the installation is 250 m3/hour, producing 70 kg phosphate/hour (DHV, 2007).

Implementability/Future Advancements/Scalability Cost Information Not widely established.

The cost of calcium phosphate production using the Crystalactor® process was estimated to be 22 times higher than the cost of mined phosphate rock (Roeleved et al., 2004), and thus at the time the process was not considered economically viable. The Crystalactor® process is an add-on, and does not require significant modification to existing solids handling processes. The process requires readily available lime to raise pH. It does not need hydrocarbon fuel inputs and therefore has a lower carbon footprint. The product can be used as fertilizer raw material. The cost of production is high relative to natural sources, but the value of the recovered calcium phosphate should increase as natural supplies decrease.

Technology Supplier DHV Water BV P.O. Box 1132 3800 AL Amersfoort The Netherlands Telephone: 0031-33-468-22 00 Fax : 0031-33-468-28 01 Email: [email protected] Web: www.dhv.com

P-RoC Application Area Wastewater treatment



Description of the Technology The P-RoC (Phosphorus Recovery from wastewater by Crystallization of calcium phosphate compounds process) uses surplus settled activated solids in the same way as Crystalactor®. The seed material in the P-RoC system under development in Germany is a tobermorite-rich

FIGURE 2-43 Process Schematic of Crystalactor® (www.dhv.com)




waste material from the construction industry (Berg and Shaum, 2005). No additional lime is required as the tobermorite is composed of calcium silicate hydrates. Tobermorite appears to stimulate the precipitation of calcium phosphate, serving as the crystallization nucleus, while it also increases the reactor pH due to its chemical properties, reducing the solubility of the calcium phosphate. A schematic for this process is illustrated in Figure 2-44.

FIGURE 2-44 Process Schematic of the P-RoC Technology (Berg et al., 2005) Comparison to Established Technologies No comparison to any established technology.

Technology Tested/Implemented or Demonstrated Studies completed at the Institute for Technical Chemistry, Water and Geotechnology Division (ITC-WGT), Forschungszentrum Karlsruhe GmbH, document pilot-scale performance of the process and the product quality. There are no known full-scale applications of the technology.

Implementability/Future Advancements/Scalability P-RoC uses waste material as both the seed for crystal development and as the pH adjustor. It does not need large energy inputs and therefore has a lower carbon footprint. The product can be used as fertilizer raw material.

Cost Information The process is under development, and no cost data are available.

Technology Supplier Forschungszentrum Karlsruhe GmbH P.O. Box 36 40, 76201 Karlsruhe, Germany www.fzk.de/itc-wgt CMM – Center of Competence for Material Moisture www.cmm-karlsruhe.de Institute for Technical Chemistry Dr.-Ing. Rainer Schuhmann, phone: +49 (0) 7247 82-3787, e-mail: [email protected] Dipl.-Ing. Dirk Patzig phone: +49 (0) 7247 82-3213, e-mail: [email protected]

Struvite Formation Application Area

http://www.fzk.de/itc-wgt

http://www.cmm-karlsruhe.de/





Wastewater treatment


Status Innovative

Description of the Technology Struvite is crystalline magnesium ammonium phosphate hexahydrate (NH4)MgPO4.6(H2O). The composition of struvite is approximately 30 percent bound phosphorus as P2O5. Unintended formation of struvite in wastewater treatment is usually detrimental to operation (blocking pipes and fouling heat transfer surfaces). Intentional formation of struvite by magnesium addition with pH adjustment was demonstrated by Burns and Moody (2002). The researchers used MgO as the magnesium source, and the X-ray diffraction of the material confirmed the presence of struvite in the product. Weidelener et al. (2007) proposed a method to leach phosphorus out of digested sewage solids and produce struvite. This method uses sulfuric acid as a leaching agent. Prior to struvite precipitation with MgCl2, interfering metal ions in the leachate are inactivated through complexation. This method allows for the production of a product that is comparable to mineral commercial fertilizers in terms of heavy metals concentration.

OSTARA’s Pearl® process (Canada) recovers struvite from a phosphorus-rich solids stream using magnesium chloride. Supplemental caustic soda may be required depending on the alkalinity and hardness of the phosphorus-bearing waste stream. Figure 2-45 shows a schematic of OSTARA’s struvite recovery process.

FIGURE 2-45 OSTARA’s Struvite Recovery Process Multiform Harvest also specializes in phosphorus recovery in the form of struvite from wastewater. It uses an up-flow fluidized bed reactor that was originally developed for agricultural liquid stream treatment. According to Ostara Nutrient Recovery Technologies Inc., the system has a conical reactor design and achieves total phosphorus reductions exceeding 80 percent and orthophosphate reductions typically exceeding 90 percent. Ammonia levels are reduced by up to 20 percent. This enables a WWTP to meet nutrient discharge limits without the use of costly chemicals, such as ferric chloride.




Technology Tested/Implemented or Demonstrated A pilot-scale struvite recovery project was conducted at the city of Edmonton Gold Bar WWTP (Alberta, Canada) by OSTARA. The pilot results showed that the process was capable of recovering over 75 percent of phosphate and 20 percent of ammonia from the solids reject water. Based on pilot results and full-scale design, an assessment of the process and environmental benefits resulting from struvite recovery was performed using a life cycle assessment framework.

The first full-scale commercial OSTARA nutrient recovery facility began operating in spring 2009 near Portland, Oregon (USA), at the Clean Water Services' Durham Advanced Wastewater Treatment Facility in Tigard, Oregon. A pilot plant had demonstrated Ostara's Pearl® nutrient recovery process at the same facility in 2007. This facility is the first to implement a full-scale commercial operation, where 100 percent of the wastewater treatment side stream was treated with this technology.

The Pearl process was recently successfully pilot-scale tested at Hampton Roads Sanitation District’s Nansemond WWTP (Virginia, USA), where it recovered more than 85 percent of the phosphorus and 40 percent of the ammonia from the liquid it processed. This led to the decision to proceed with full-scale implementation of the technology.

Implementability/Future Advancements/Scalability Pilot testing at the Edmonton Gold Bar WWTP showed that struvite recovery has the potential for offsetting meaningful amounts of GHG emissions through sustainable and energy-efficient production of fertilizers. At full scale, struvite recovery would result in the production of up to 1,200 tons per year of struvite fertilizer along with a 20 percent reduction in the phosphorus load and a 5 percent reduction in the ammonia load on the WWTP. The life cycle assessment also showed that the full-scale plant would result in the offset of approximately 12,000 tons of carbon dioxide equivalent emissions per year relative to conventional fertilizer manufacturing.

In the full-scale operation at the Durham facility in Tigard, Oregon, USA, Ostara's Pearl® nutrient recovery process is currently removing more than 90 percent of the phosphorus in the wastewater's liquid stream and producing 500 tons of struvite under the commercial name of Crystal Green® fertilizer annually.

According to Ostara Nutrient Recovery Technologies Inc., the Multiform Harvest system is currently used at agricultural operations and recently was selected by the City of Boise, Idaho, USA for implementation at the City’s WWTP.

Cost Information Case-specific and not disclosed by the technology suppliers.

Technology Suppliers Ostara Nutrient Recovery Technologies Inc. 690 – 1199 West Pender Street Vancouver, BC V6E 2R1 Telephone: 604 408 6697 Fax: 604 408 4442

Multiform Harvest Inc. 2033 Sixth Avenue Suite 253 Seattle, Washington 98121-2580 Tel: 206-725-3305 [email protected]



Salt Solidification and Sequestration (SAL-PROC) Application Area Concentrate/brine streams

Objective Recovery of salt from concentrate/brine streams

Status Innovative

Description of the Technology SAL-PROC™ is a patented process of Geo-Processors USA, Inc., Glendale, California, USA. It is an integrated process for the sequential or selective extraction of dissolved elements from saline waters in the form of salts and chemical compounds (mineral, slurry, and liquid forms). The process involves multiple evaporation and/or cooling steps supplemented by conventional mineral and chemical processing. This technology is based on a closed-loop processing and fluid flow circuits, which enable the partial or complete treatment of inorganic saline streams for recovery of valuable by-products. According to Geo-Processors, field trials and pilot testing indicated that a number of saline waste streams can be converted into marketable products (precipitated salts) while achieving ZLD. The chemicals typically recovered from saline streams include gypsum-magnesium hydroxide, magnesium hydroxide, sodium chlorite, calcium carbonate, sodium sulfate, and calcium chloride. A simplified SAL-PROC process schematic is illustrated in Figure 2-46.

The ZLD systems utilize multiple reaction steps using lime and soda ash to produce carbonated magnesium, calcium carbonate, and a mixed salt. The overall system recovers nearly entire flow. However, SAL-PROC requires incorporation of one or more desalting technologies to reduce volume significantly while highly concentrating water entering the

SAL-PROC.

SAL-PROC is not a stand-alone brine concentrate treatment technology. This process acts as a product recovery process. The suitability of using SAL-PROC depends upon the water quality and type of application. RO concentrate from water reuse facilities might not be permitted to recover products because wastewater RO concentrate may contain organic, toxic, and hazardous material.


Technology Tested/Implemented or Demonstrated According to Geo Processor Inc., this technology is in full-scale application for produced water treatment in Queensland, Australia. The system produces 21,600 tons of saleable chemicals per year.

FIGURE 2-46 SAL-PROC Process Schematic



Implementability/Future Advancements/Scalability This technology has not been widely used to date despite the commercialization of this technology in early 2000s. Knowledge regarding capital and O&M costs and process performance under varying feed quality conditions has not been established. The implementability of the process also depends on the cost-competitiveness of the product and the availability of potential buyers.

Cost Information: Case-specific, and not disclosed by the technology suppliers.

Technology Supplier Geo Processor Inc. 690 – 1199 West Pender Street Glendale, CA, USA Telephone: 604 408 6697 Fax: 604 408 4442

Other Technologies: Greenhouse Sludge Drying Systems Application Area Wastewater treatment

Objective Low-energy biosolids drying

Status Innovative

Description of the Technology Greenhouse drying is an alternative to the conventional sludge drying beds that are used at treatment facilities typically smaller than 5 mgd. This technology uses sunlight to evaporate a large portion of the water content of the biosolids. Greenhouse drying beds have been successfully used in Europe and the USA, and are cost–effective for 1.0-to 10-mgd plants, because they require a minimal amount of energy, labor, and maintenance. In typical installations, biosolids are spread over a large covered area, similar to a greenhouse, while the sunlight evaporates the water. During drying, the biosolids are turned and mixed. Ventilation is an important factor to continually remove moisture-laden air from the surface of the biosolids and replace it with fresh dry air. The product solids content can be 85 to 90 percent depending on the operation. Both batch and continuous operation is possible. A schematic of a version of this process marketed by Huber is shown on Figure 2-47. Use of a heat recovery loop from wastewater as shown is optional.

Comparison to Established Technologies Potential Advantages over Established Technologies • Fully automated control possible

• Active drying with a turning system included

• Can be coupled with a heat recovery/heat exchange system if necessary

• Cost-competitive when compared to gas-fired/mechanical drying systems, with much lower operating costs

• Odors contained in the greenhouse structure

• The greenhouse type design provides containment from external factors, such as wind and rain

• High-quality dried biosolids with low pathogen content can be produced



Potential Disadvantages Compared to Established Technologies • More costly compared to conventional passive sludge drying beds

• Although possible to automate, includes more mechanical parts compared to conventional passive sludge drying beds

Technology Tested/Implemented or Demonstrated This technology has been implemented at facilities that range from less than 1 mgd to 10 mgd. The supplier indicated that the Parkson Thermo-System dryer has been applied to 0.2-mgd to 40-mgd systems. According to the information from Parkson Corporation, there are Thermo-System units in operation in the USA in Florida, Hawaii, Indiana, Oregon, and South Carolina, and in Palma de Mallorca, on the Mediterranean island of Mallorca. Parkson's German licensor for this technology had previous installations in Germany, Italy, Belgium, Austria, and Australia for both municipal and industrial applications.

Implementability/Future Advancements/Scalability The technology has recently been implemented at full scale. Considering the land availability in the arid areas of KSA, the technology could be favored over other higher-energy-consuming (gas-fired or mechanical) or passive drying bed type alternatives, and it would be a suitable option for many locations in KSA. The greenhouse type design also provides containment from external factors (such as wind and rain), which is not available for open drying beds.

Cost Information Capital cost depends on the unit sizing based on location and the components included.

Operating costs are significantly lower than those of gas-fired and mechanical drying systems; the energy requirement is about 40 kWh per ton of water evaporated, with no additional thermal energy supplement required unless the footprint needs to be reduced with external heat addition, depending on site space availability.

FIGURE 2-47 Process Schematic of Greenhouse Drying Process (Huber Technology)



Technology Suppliers Parkson Corporation Corporate Head Quarters 1401 West Cypress Creek Road Fort Lauderdale, FL 33309-1969 Tel 1.888.PARKSON Fax 954-974-6182 http://www.parkson.com

United Arab Emirates Parkson ME LLC PO Box 233160 Dubai, UAE Tel: +971.4.280.8923 Fax: + 971.4.280.8932

Huber Technology Inc. Nasik Group, Prince Abdallah Road El Mursalat Quarter Al Omar Furniture Blg P.O.Box : 8658 Riyadh 11462, Saudi Arabia Tel: +966 1 45 67 377 Fax: +966 1 45 48 166 http://www.huber-technology.com

2.3.5 Natural Treatment Systems Natural treatment systems are well established and have been used throughout the world for treatment and polishing of wastewaters. Information on these systems is summarized in Appendix A. Recently wetlands have been used as an alternative solution in reducing the temperature of wastewater effluents to satisfy discharge temperature requirements. Recently, aquifer storage and treatment has attracted interest in reuse projects and has been proven and successfully applied to many locations in Germany and the USA. Because aquifer storage and treatment is a promising approach for KSA, it is evaluated in detail in Chapter 4.

2.4 Comparison of Innovative/Developmental Technologies This section provides a relative comparison of innovative/developmental technologies using Tables 2-2 through 2-6. Technologies are categorized and comparisons are made relative to a defined established technology, if applicable. Reference technologies are shown in parentheses.

1. Desalination technologies (RO) 2. Disinfection technologies (chlorine-based disinfection) 3. Filtration technologies (pressurized polymeric membrane systems) 4. Biological treatment technologies (CAS systems) 5. Side stream treatment technologies (SHARON)

http://www.parkson.com/

http://www.huber-technology.com/



TABLE 2-2 Summary and Comparison of Innovative/Developmental Desalination Technologies

Tech

nolo

gy

Stat

us

Impl

emen

tabi

lity

in N

ext 5

Yea

r

App

licab

ility

to S

mal

l to

Larg

e Sy

stem

s

Hea

t Usa

ge C

ompa

red

to T

herm

al

Proc

ess

(80

kWh/

m3)

Ener

gy U

sea

Foot

prin

ta

Rec

over

ya

Trea

ted

Wat

er Q

ualit

ya

Foul

ing

Prop

ensi

tya

Com

plex

ity o

f Ope

ratio

n an

d M

aint

enan

cea

Proc

ess

Che

mic

al U

se In

clud

ing

Pret

reat

men

t and

Pos

t Tre

atm

ent

Reg

ulat

ory

Acc

epta

bilit

y in

Reu

se

App

licat

ions

a

ARROW P,C P S NR ? ↑ ↑ ◊ ↓ ↑ ↑↑ ◊

CD B,P,C L S,L NR ◊ ◊ ↓ ↓ ↓ ↑ ◊ ↓

Dewvaporation B,P,C,F L S, L ↑↑ ↓ ↑ ↑ ↑↑ ↓ ↑ ↓ ◊

DDD B P S ↑ ↓ ↑ ↑ ↑↑ ↑ ↑ ↓ ◊

Ecosphere P,C P S NR ↑ ↑ ↓ ◊ ◊ ↑ ↑↑ ◊

FO B,P,C ML S,L,I ↓ ↑ ◊ ◊ ↓ ◊ ◊ ◊

HIX-NF B U S NR ? ? ◊ ↓ ↓ ↑ ? ↓

MD B,P,C ML S,L,I ↓ ◊ ◊ ◊ ↑ ↓ ↑ ↓ ◊

MDC B U S NR NR ? ↓↓ ↓↓ ↓ ↓ ↓↓ ↓

NF B,P,C ML S,L,I ◊ ↓ ↓ ↑ ↓ ◊ ◊ ◊ ↓

Nanotech-nology App.

B,P, C ML S,L,I ◊ ◊ ↓ ◊ ◊ ◊ ◊ ◊ ◊

OPUS P,C P S NR ? ↑ ↑ ◊ ↓ ↑ ↑↑ ◊

Solar Desalina-tion (Coupled with RO or MED)

P,C ML S,L,I ◊,↑ ◊,↓ ↑↑ ◊,↑ ◊,↑ ◊,↓ ◊,↑ ◊,↓ ◊

SPARRO P,C ML S,L,I ◊ ◊ ◊ ↑ ◊ ↓ ↑ ◊ ◊

ZDD P,C ML S, I NR ◊ ↑ ↑ ↓ ◊,↓ ↓ ◊ ↓

a Compared to conventional RO systems NR: Not required ◊: Similar to RO ↑: Higher or more than RO ↑↑: Much higher than RO ↓: Less than RO ↓↓: Much less than RO Status Designation: B: Bench-scale C: Commercialized F: Full-scale P: Pilot

Implementability Designation: U: Unlikely P: Possible L: Likely ML: Most Likely Applicability Designation: S: Small plants I: Industrial L: Large plants



TABLE 2-3 Summary and Comparison of Innovative/Developmental Disinfection Technologies

Tech

nolo

gy

Stat

us

Impl

emen

tabi

lity

in N

ext 5

Yea

r

Reg

ulat

ory

Acc

epta

bilit

y in

Reu

se

App

licat

ions

App

licab

ility

to S

mal

l to

Larg

e Sy

stem

s

Oxi

datio

n C

apab

ilitie

sa

DB

P F

orm

atio

na

Col

iform

Inac

tivat

iona

Viru

s In

activ

atio

na

Foot

prin

ta

Ener

gy R

equi

rem

enta

Com

plex

ity o

f Ope

ratio

n an

d M

aint

enan

cea

Re-

grow

th P

oten

tiala

Ferrate P,C L P S,L ◊↑ ↓ ◊ ? ? ◊ ↑ ↑↑

Microwave UV P,C,F

ML A S,L ↓ ↓↓ ◊ ◊ ↓ ↑ ↑ ↑

Pasteurization B,P,C

L A S ↓ ↓ ◊ ↑ ↓ ↑↑ ↑ ↑

PAA B,P P P S, L ↑ ↓ ↓ ↓ ↑ ◊ ◊ ↑

Photocatalysis B U P S,I ↑ ↓ ◊ ? ? ? ↑ ↑

Simultaneous Use of Two or More Disinfectants

B,P,F

ML ML S,L ◊↑ ↓ ◊↑ ◊↑ ↓ ◊↑ ↑ ◊↑

Solar Disinfection

B U P S ↓ ↓↓ ↓ ↓ ↑↑ ↓ ◊ ↑↑

Ultrasonic Cavitation

B,P U P S ↓ ↓ ◊ ? ↓ ↑↑ ↑ ↑↑

a Compared to chlorine based disinfection systems NR: Not required ◊: Similar to chlorine disinfection ↑: Higher or more than chlorine disinfection ↑↑: Much higher than chlorine disinfection ↓: Less than chlorine disinfection ↓↓: Much less than chlorine disinfection Status Designation: B: Bench-scale C: Commercialized F: Full-scale P: Pilot Implementability and Regulatory Acceptance Designation: U: Unlikely P: Possible L: Likely A: Accepted ML: Most Likely Applicability Designation: S: Small plants I: Industrial L: Large plants



TABLE 2-4 Comparison of Filtration Technologies

Tech

nolo

gy

Stat

us

Impl

emen

tabi

lity

in N

ext 5

Yea

r

App

licab

ility

to S

mal

l to

Larg

e Sy

stem

s

Flux

a

Rec

over

ya

Che

mic

al a

nd M

echa

nica

l Tol

eran

cea

Ener

gy R

equi

rem

enta

Foot

prin

ta

Cap

ital C

ost1

O&

M C

osta

Com

plex

ity o

f Ope

ratio

n an

d M

aint

enan

cea

Ceramic Membranes B,P,C,F I S,I,L ↑↑ ↑ ↑↑ ↓ ↑ ↑ ↓ ↓

◊: Similar to Pressurized Polymeric Membranes ↑: Higher or more than Pressurized Polymeric Membranes ↑↑: Much higher/better than Pressurized Polymeric Membranes ↓: Less than Pressurized Polymeric Membranes ↓↓: Much less than Pressurized Polymeric Membranes Status Designation: B: Bench-scale C: Commercialized F: Full-scale P: Pilot Implementability Designation: U: Unlikely P: Possible L: Likely ML: Most Likely I: Implemented Applicability Designation: S: Small plants I: Industrial L: Large plants



TABLE 2-5 Summary and Comparison of Innovative/Developmental Biological Treatment Technologies

Tech

nolo

gy

Stat

us

Impl

emen

tabi

lity

in N

ext 5

Yea

r

App

licab

ility

to S

mal

l to

Larg

e Sy

stem

s

BO

D R

emov

al P

erfo

rman

cea

Nitr

ogen

Rem

oval

Per

form

ance

a

Emer

ging

Con

tam

inan

t Rem

oval

Pe

rfor

man

cea

Rob

ustn

ess

of P

roce

ssa

Ener

gy R

equi

rem

enta

Foot

prin

ta

Slud

ge G

ener

atio

na

Gas

Gen

erat

iona

Com

plex

ity o

f Ope

ratio

n an

d M

aint

enan

cea

AnMBR B,P,C,F

I S,I ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↑ ↑

AMBR B, F P S ↓ ↓ ↓ ↓ ↓ ? ◊ ↑ ◊

MABR B U S ◊ ↓ ◊ ? ↓ ↓ ↓ ↑↑ ↑

MBfR B,P L S,I ◊ ↓ ↑ ◊ ↓ ↓ ↓ ◊ ◊

NEREDA P, C L S,I,L ◊ ◊ ◊ ↑ ◊ ↓ ◊ ◊ ↓

MSABP P,C, F I S ◊ ◊ ◊ ◊ ↓ ↓ ↓ ◊ ↓

DEMON B,P,F I S,I,L ↓ ◊ ↓ ◊ ↓ ↓ ↓ ◊ ◊

VRM B, C,F I S,I,L ◊ ◊ ◊ ◊ ↓ ↓ ↓ ◊ ↓

aCompared to CAS systems NR: Not required ◊: Similar to CAS ↑: Higher or more than CAS ↑↑: Much higher/better than CAS ↓: Less than CAS ↓↓: Much less than CAS Status Designation: B: Bench-scale C: Commercialized F: Full-scale P: Pilot Implementability Designation: U: Unlikely P: Possible L: Likely ML: Most Likely I: Implemented Applicability Designation: S: Small plants I: Industrial L: Large plants



TABLE 2-6 Summary and Comparison of Side Stream Treatment Technologies

Tech

nolo

gy

Stat

us

Impl

emen

tabi

lity

in N

ext 5

Yea

r

App

licab

ility

to S

mal

l to

Larg

e Sy

stem

s

Nitr

ogen

Rem

oval

Per

form

ance

a

Foot

prin

ta

Met

hano

l Req

uire

men

ta

Oxy

gen

Req

uire

men

ta

Ener

gy R

equi

rem

enta

Slud

ge G

ener

atio

na

Com

plex

ity o

f Ope

ratio

n an

d M

aint

enan

cea

STRASS B,P,C,F I S,I,L ◊ ◊ ◊ ◊ ◊ ◊ ◊

SHARON/ANAMMOX

B,P,C,F I S,I,L ◊ ↑ NR ↓ ↓ ↓ ◊

DEMON B,P,C,F I S,I,L ◊ ↑ NF ↓ ↓ ↓ ◊

aCompared to SHARON NR: Not required ◊: Similar to SHARON ↑: Higher or more than SHARON ↑↑: Much higher/better than SHARON ↓: Less than SHARON ↓↓: Much less than SHARON Status Designation: B: Bench-scale C: Commercialized F: Full-scale P: Pilot Implementability Designation: U: Unlikely P: Possible L: Likely ML: Most Likely I: Implemented Applicability Designation: S: Small plants I: Industrial L: Large plants

2.5 Impact of Wastewater Quality on Operation and Performance of Treatment Unit Processes

The wastewater characteristics are of great significance in the treatment and reuse of wastewater. Once treated wastewater quality objectives or requirements are set for reuse, the selection of the treatment scheme is determined primarily by the wastewater composition. Wastewater composition is of pivotal importance in operation and performance of the unit treatment processes. A comprehensive wastewater quality characterization is essential to accomplish a reliable assessment that adequately addresses wastewater quality impacts on the operation and performance of the treatment processes. Unfortunately, the data available are limited to a few conventional wastewater parameters (BOD5, TSS, total Kjeldahl nitrogen [TKN], TDS, pH, etc.), which are not comprehensive enough for the



purpose of evaluation. In this section, a generic approach is taken to address potential impacts of inorganic and organic compounds on operation and performance of reuse and advanced treatment processes. Table 2-7 summarizes key wastewater quality parameters and their impacts on operation and performance of the unit treatment processes.

2.6 Industries in KSA with Reuse Potential Many industrial manufacturing processes (such as those at pulp and paper facilities, oil refineries, and chemical manufacturing facilities) depend on reliable and large quantities of water. Unlike many reuse schemes which have seasonal patterns of water demand such as those used for agricultural and landscape irrigation, industries tend to use water at a relatively constant rate throughout the year. Therefore, industries provide a unique opportunity for year-round use of reclaimed water. In addition, industries are often required to meet increasingly stringent discharge goals, particularly for wastewater discharges. A long-term objective of industries is to minimize or eliminate discharges to receiving waters or sewer systems by applying ZLD concepts (Metcalf and Eddy, 2003). Industries have been implementing more efficient water use practices and adopting internal wastewater treatment and recycling, where practicable.

According to KAUST Industrial Collaboration Program (KICP) members, cement manufacturing, iron and steel manufacturing, and petroleum refineries have great potential for industrial reuse in KSA. The main objective of this sub-section was to identify wastewater characteristics and evaluate potential reuse schemes for those industries. However, despite considerable effort through communication with KICP members, communication with universities, and an extensive literature search, adequate information regarding industrial wastewater characterization in KSA could not be obtained. Wastewater characteristics for the three candidate industries were assumed to be similar to those reported in industrial textbook references (Industrial Wastewater Management, Treatment and Disposal, WEF, MOP FD-3, 2008). As a result, that information was used. Any pertinent information on this subject, if obtained later, will be incorporated into the final report.

Cement manufacturing facilities process aluminum, silica, limestone, clay, chalk, and iron oxides to produce cement. Wastewater is generated via process equipment cooling, cement kiln-dust recovery via wet scrubbing, and materials storage pile runoff (WEF, FD-3, 2008). The main wastewater pollutants are TDS (potassium, sodium, chlorides, and sulfate) and suspended solids. Recycled water can be used in cooling towers. Suspended solids can be removed using settling ponds or clarifiers.

Iron and steel manufacturing facilities produce carbon steels, alloy steels, and stainless steels. Water is used for cooling and cleaning of process off-gases, direct cooling of coke and slag, direct cooling and cleaning of steel, product rinsing, process solution, makeup water, and direct cooling of process equipment. Other sources of wastewater include slag quenching, equipment cleaning, rinse water and contaminated cooling water (WEF, FD-3, 2008). The main wastewater pollutants are oil and grease, TSS, ammonia, cyanide, fluoride, nitrite/nitrate, COD, TKN, TOC, hydrocarbons, and several other priority and nonconventional organic compounds. For coke making, wastewater treatment includes oil and grease removal, ammonia removal via stripping, and flow equalization before biological treatment. Activated sludge systems with nitrification/denitrification are the most common type of biological treatment systems. For iron ore processing, the recommended treatment technologies are solids removal with metals precipitation using lime, caustic, magnesium hydroxide, or soda ash, break-point chlorination for ammonia removal, and multimedia filtration for solids removal. For steel making, wastewater can be treated for recycling via a high-volume classifier followed by a clarifier for solids removal, wet open combustion to remove scale formers, and further blowdown treatment via metals precipitation (WEF, FD-3, 2008).



TABLE 2-7 Wastewater Quality Parameters and Their Impacts on Operation and Performance of Unit Treatment Processes

Parameter Impact Mitigation

Ammonia--high in secondary effluent

Increases chlorine demand during disinfection Causes corrosion in copper-based alloys Stimulates biological growth

Provide ammonia removal during wastewater treatment

Alkalinity--low in raw wastewater

Reduces or diminish biological nitrification performance

Add alkalinity (caustic, lime, sodium bicarbonate, etc.)

Alkalinity--high in secondary effluent

Increases scaling potential of membranes and requires more frequent cleaning Reacts with hydroxyl radical and reduces the efficiency of advanced oxidation processes

Acidify feed water

Barium--high in secondary effluent

Promotes membrane scaling when combined with sulfate

Add antiscalant Reduce either sulfate or barium using IX or other technologies

BOD/TKN--low in raw wastewater

Reduces nitrogen removal performance in biological nitrogen removal plants

Add external organic carbon source (such as methanol) or use prefermenter to supplement organic compounds to drive denitrification

BOD--high in secondary effluent

Promotes biological growth and fouls membranes Requires more frequent membrane cleaning and backwashes Increases disinfectant/oxidant demand Reduces efficacy of UV disinfection and other disinfection processes

Provide pretreatment (such as PAC, granular activated carbon [GAC], biologically activated carbon [BAC] or ozone) to reduce BOD, if needed

Calcium--high in secondary effluent

Promotes membrane scaling when combined with scale-forming ions such as carbonate, fluoride, sulfate and phosphate Fouls UV lamps

Acidify feed water (effective for controlling only CaCO3 and Ca3(PO4)2 Add antiscalant Soften wastewater

Free chlorine, present in disinfected secondary effluent

Polymeric NF/RO membranes have no tolerance to free chlorine even at trace concentrations (<0.1 mg/L) EDR membranes have very little tolerance for free chlorine (must be less than 0.5 mg/L)

Dechlorinate the wastewater or add ammonia to form combined chlorine

Fluoride--high in secondary effluent

Promotes membrane scaling when combined with calcium

Add antiscalant Reduce either calcium or fluoride, if needed

Hardness--high in secondary effluent

Promotes membrane scaling and causes a loss of productivity and deterioration of permeate quality Fouls UV lamps

Reduce hardness

Iron and Manganese--high in secondary effluent

May oxidize or form complexes with other constituents and promote membrane fouling May damage membranes Fouls UV lamp and reduced form reacts with oxidants (such as chlorine, ozone, hydrogen

Provide pretreatment for iron and manganese




Parameter Impact Mitigation peroxide) and increases oxidation demand

Magnesium--high in secondary effluent

Promotes scale formation

Reduce hardness

Microbial Parameters Fouls low and high pressure membranes Provide pretreatment (feed water chloramination for example) to reduce microbiological fouling

Oil and Grease--high in raw wastewater

May promote Nocardia sp. growth and foaming. Reduces settlability, filterability, and permeability

Establish good management practices for oil and grease removal

Oil and Grease--high in secondary effluent

Fouls membranes Exerts oxidant demand Can form a film on UV lamps and reduce effectiveness of UV disinfection

Establish good management practices for oil and grease removal

pH--raw wastewater pH must be close to neutral range to allow biological reactions

Add chemicals to bring pH to neutrality

pH--secondary effluent Affects chemical reactions, dissolution, and precipitation of metals and sparingly soluble salts. High pH increases CaCO3 and Ca3(PO4)2 precipitation potential

Make pH adjustment

Phosphate--high in secondary effluent

Promotes membrane scaling Stimulates biological growth

Add acid and antiscalant Provide biological or chemical phosphorus removal to reduce phopshorus

Silica (SiO2)--high in secondary effluent

Promotes membrane scaling Add antiscalant Remove silica with either lime softening or high pH IX

Strontium--high in secondary effluent

Promotes membrane scaling when combined with sulfate

Add antiscalant Reduce strontium, sulfate, or both

Sulfate--high in secondary effluent

Promotes membrane scaling when combined with scale-forming ions such as calcium, barium, or strontium Increases corrosion

Add antiscalant Reduce either sulfate or scale-forming ions

Temperature--raw wastewater

WWTPs are designed to perform under a wide range of temperatures and other operating conditions to ensure balanced microbial growth, proper oxygenation and mass transfer, biochemical transformation for organic and inorganic contaminant removal.

Temperature--secondary effluent high

Increases precipitation tendency of sparingly soluble salts, which increases scaling potential of NF/RO membranes and increases UV lamp fouling Increases salt passage and permeability in NF/RO membranes Reduces feed pressure for NF/RO membranes




Parameter Impact Mitigation

TDS--high in secondary effluent

High TDS is a direct indicator of elevated levels of sparingly soluble salts that promote membrane scaling and cause a loss in productivity and deterioration in permeate quality. The sparingly soluble salts of concern include CaCO3, CaF2, CaSO4, BaSO4, Ca3(PO4)2, SrSO4, and silica (SiO2).

Add acid and antiscalant Reduce individual ions

TOC--high in secondary effluent

Promotes organic/microbiological fouling on membranes. Reduces efficiency of UV disinfection.

TOC fouling is best managed with proper flux selection

TSS--high in secondary effluent

Increases headloss or TMP during filtration, shortens filtration times and membrane run times, and reduces productivity Reduces efficacy of UV disinfection

Provide coagulation prior to filtration

Turbidity--high in secondary effluent

Impacts are very similar to those of TSS

Provide coagulation prior to filtration

Petroleum refining facilities process crude oil into various petroleum products via a series of physical and chemical processes. Petroleum refinery wastewaters consist of process wastewater, cooling tower blowdown, boiler blowdown, surface water runoff, and sanitary wastewater. Wastewater generation is significant (up to 31,000 m3/day is reported, WEF, FD-3, 2008). The main wastewater constituents include BOD5, oil and grease, pH, TSS, amines, ammonia, chlorides, COD, hydrogen sulfide, mercaptans, phenol, solvents, and TDS. Wastewater treatment typically starts with segregation and treatment of sour water (containing dissolved hydrogen sulfide, organic sulfur, and ammonia) via gas stripping before discharge to the WWTP. Oil and solids removal is accomplished using dissolved air floatation or settling ponds before biological treatment. Biological treatment options include CAS systems, stabilization ponds, or trickling filters. In some instances, activated carbon or sand filters can be used for polishing. MBR use couples biological treatment with membrane filtration and eliminates further polishing.

The water quality requirements for industrial use may vary among the industries. For example, most cooling towers at oil refineries require either secondary disinfected or tertiary treated reclaimed water. Some industries may require much higher water quality (such as high-pressure boiler feed water, semiconductor industry) where advanced treatment technologies (such as RO and MED) produce such high-quality water. In each case, a number of technologies can be used to meet industries’ reclaimed water quality objectives. The selection of technology depends on the quality of the wastewater to be treated, site-specific factors (such as available space), project-specific constraints (chemical requirements, sludge and waste disposal requirements, ease of operation, etc.) and capital and O&M costs.

Industries may be deterred from using reclaimed water because of the high conveyance costs (piping and pumping) for conveying water from the water reclamation facility to the site of use. Conveyance costs, on the other hand, have a very minor impact on water reuse project costs if industrial facilities are located near water reclamation facilities or do not require pumping. Industrial reuse case study examples discussed in Chapter 4 indicate that the cost savings offered by the use of reclaimed water often outweigh the costs of implementing additional treatment facilities to meet specific industrial process water quality



requirements. Reasonable water tariffs for industries make water conservation, treatment, and reuse an attractive option for industries.

2.7 Summary and Path Forward The need for alternative water resources, coupled with increasingly stringent water quality discharge requirements, are the driving forces for developing water reuse strategies in the world today. The growing trend is to consider water reuse as an essential component of integrated water resources management and sustainable development, not only in dry and water-deficient areas, but in water-abundant regions as well. Therefore, many wastewater utilities are considering designing systems suitable for potential future water reuse applications.

The technologies currently used for water reclamation have evolved from operations and processes used for water and wastewater treatment (Metcalf and Eddy, 2003). With the valuable scientific knowledge developed over the past decade concerning emerging constituents found in water and wastewater, the focus on water quality in water reuse applications (such as indirect potable reuse applications) has greatly intensified. Therefore, in response to water quality concerns, greater emphasis has recently been placed on technologies that provide very efficient removal of suspended solids, pathogens, dissolved solids, and emerging compounds. California Department of Health requires double membrane barriers and advanced oxidation to address water quality concerns in groundwater recharge projects in California (commonly referred to as indirect potable reuse). Similar advanced water treatment schemes have been replicated in many indirect potable reuse projects across the globe. Figure 2-48 presents a schematic of the advanced water treatment schemes used at the Luggage Point Facility in Australia.

Many readily available current technologies are highly effective in reliably producing RQTSE, which can be used for many purposes in KSA.

Other emerging and developmental technologies will soon be more widely available to further increase the benefits of reuse by using less energy, or satisfying energy needs from renewable sources or waste heat, creating less reject stream and unwanted byproducts, treating and recovering concentrate streams for ZLD. These technologies can also be adapted in KSA for treating and recovering wastewater streams

This chapter summarized technologies that can be applicable for wastewater treatment, reclaimed water, and beneficial reuse in KSA. The following summary reflects the key highlights and provides guidance on the path forward.

• According to the proposed Draft Reuse Regulations for KSA (March 2011), reuse schemes requiring secondary and tertiary treated wastewater shall meet the ammonia nitrogen and nitrate nitrogen limits of 5 and 10 mg/L, respectively. While BOD and TSS limits can be satisfied by employing low carbon footprint technologies such as facultative and oxidation ponds or constructed wetlands, more engineered technologies are needed to meet proposed nitrogen limits. Some example technologies include Orbal ditches, biologically active filters, Biolac, CAS and SBR systems designed for and operated at biological nitrogen removal modes. CAS systems are highly proven and flexible for conversion to MBR and biological/chemical phosphorus facilities, if higher-quality water or phosphorus recovery is needed. Depth media filtration (such as mono, dual and multimedia filtration, Dynasand, etc.) and surface media filtration (disc and cloth media filters) are low carbon footprint solutions compared to membrane based filtration technologies. These technologies can meet the turbidity limit of 5 NTU proposed for secondary and tertiary treated wastewaters. Chlorine disinfection can satisfy pathogen limit to meet secondary and tertiary treated wastewater criteria. Sequential use of multiple disinfection, such as chlorine-UV, chlorine-chloramination, UV-ozone, can be considered for reducing DBP concerns.



• For reuse applications requiring high water quality, use of a desalination technology for salt and dissolved organic removal (high quality industrial applications, groundwater recharge, etc.), following technologies could replace traditional RO use in the near future. Use of ceramic membranes will provide adequate pretreatment for desalination technology at reduced O&M costs:

− Nanofiltration. This is a very promising technology that can remove TDS and reduce emerging contaminants using much lower operating pressures than conventional RO membranes. NF can be combined with aquifer storage and treatment projects to meet indirect potable reuse requirements. One drawback of NF use is the low rejection of nitrate which should be a concern for projects requiring additional nitrate removal. One solution is to design or convert the existing wastewater treatment facility that will supply the feed water for NF to achieve nitrogen removal upstream of NF.

− Solar desalination. The high solar energy potential of KSA can be used in solar projects to generate heat or electricity to drive desalination.

− Humidification/dehumidification and membrane distillation. These processes are attractive, if waste heat, low grade heat, or solar heat is available.

− Forward Osmosis. Literature studies have shown that FO is a potentially a viable low carbon footprint desalination alternative. Although the energy associated with FO is low, the energy associated with reconstitution of draw solution, is potentially as high as the desalination of seawater. Therefore, more research needs to be done to identify draw solutions which do not require substantial energy when draw solution is reconstituted.

• Although anaerobic technologies reduce processing energy requirements in wastewater treatment, gas production for energy may not be sufficient to justify the cost for treating domestic wastewaters. Gas to energy benefits of these technologies may be recognized when treating high COD containing industrial wastewaters.

• Deammoniafication (DEMON) appears to be the most promising technology reducing energy requirement and WAS generation without the need for organic carbon and alkalinity addition for nitrogen removal. Although under current conditions, it is not cost competitive for treatment of relatively low ammonia containing wastewaters (i.e., 25-40 mg/L ammonia-N typically found in raw domestic sewage), the recent research clearly

FIGURE 2-48 Luggage Point Potable Reuse Plant Schematic

RO FEED TANK

FEED EQUALISATION

SECONDARY EFFLUENT FEED

PUMP

PFE

RRIC

CHL

ORID

E

SODI

UM H

YPOC

HLOR

ITE

FLOCCULATION/CLARIFIER PACKAGE

SYSTEM

P

MICRO FILTRATION

SETTLED WATER

STORAGE TANK

P

ANTI

SCAL

ANT

P

FINE SCREEN

P

DENITRIFYING FILTER

METH

ANOL

NITR

ATE

UV/ADVANCED OXIDATION

GRAVITY TO DRAIN

HYDR

OGEN

PE

ROXI

DE

AMMO

NIA

CONCENTRATE STORAGE TANK

RO PRODUCT STORAGE

P

DISCHARGE TO DRAIN

BACKWASH TO WASTE

SLUDGE TO WASTE

P

CARTRIDGE FILTER REVERSE OSMOSIS TREATED

WATER STORAGE

TANKMO

NOCH

LORA

MINE

P

MF BACKWASH RECYCLE

P

SERVICE WATER



shows that is a very good alternative for treating high ammonia containing side-streams generated from sludge dewatering facilities.

• Hydrogen-based membrane biofilm reactor (MBfR) technology is a low carbon footprint technology for treatment of oxidized compounds (nitrate, perchlorate, chlorate, etc.) from wastewaters. The ineffectiveness of this process in removing reduced forms of organic compounds, however, can limit use of this technology in wastewater treatment.

• Carbon sequestration processes are very attractive for generating renewable energy. However, most of these technologies are in early developmental stages, so it is unlikely that these technologies will be seen in full-scale applications in the near future. Micro-algae to biodiesel is the most investigated and potentially valuable technology for KSA given the availability of vast land areas and high solar energy potential. Advances in reactor technologies, harvesting methods, and final production technologies will likely move this technology to a very prominent position in the near future. In the meantime, numerous approaches can be taken to reduce energy consumption in wastewater treatment facilities. Some examples include use of intermittent aeration, automated SRT/DO control in activated sludge processes, ultrafine bubble diffusers, use of low-pressure high-output UV systems and variable frequency drives with pumps.

• Phosphorus recovery technologies can be a good fit for KSA considering the extensive agricultural and animal farming operations there. However, implementability of phosphorus recovery technologies depends on the generation of enriched phosphorus streams in the WWTP (e.g., anaerobically digested sludge) and the availability of markets/users for the products. These technologies are suitable for large wastewater treatment facilities or centralized biosolids digestion facilities.

• Typical wastewater collection and disposal practices involve conveying all the wastewater generated in a particular drainage to the most downstream (terminal) site for treatment. As an alternative, decentralized reclamation plants (sometimes referred to as “satellite” or “scalping” plants) can be used to intercept a portion of the collected wastewater higher up in the drainage. Decentralized reclamation plants treat and recycle water to a nearby distribution area and avoid otherwise wasted energy in pumping back uphill from the more downstream terminal plant location. Centralized facilities, on the other hand, make solids processing and resource recovery processes more cost-effective.

2.8 References Acra, A., Z. Raffoul, Z. and Y. Karahagopian. 1984. Solar Disinfection of Drinking Water and Oral Rehydration Solutions. UNICEF (extract).

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Baldry M.G.C. and French M.S. 1989. Activity of Peracetic Acid against Sewage Indicator Organisms. Water Science and Technology, 21, 1747-1749.

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Bellona C., K. Bugdell, D. Ball, K. Spangler, J.E. Drewes and S. Chellam. 2011. Models to Predict Organic Contaminant Removal by RO and NF Membranes. Proceedings of



American Water Works Association Membrane Technology Conference and Exposition. March 2011.

Berg, U. and Schaum, C. 2005. Recovery of Phosphorus from Sewage Sludge and Sludge Ashes: Applications in Germany and Northern Europe. Proceedings, 1st National Sludge Symposium, Izmir, Turkey, March, 23rd – 25th, 2005.

Biagini, B., B. Mack and T.A. Davis. 2010. Zero Discharge Desalination (ZDD) Technology – High Recovery Solution for Inland Desalination to Significantly Reduce Brine Disposal. Proceedings of AMTA Annual Conference and Exposition. July 2010.

Blanco J., D. Alarcon, E. Zarza, S. Malato and J. Leon. 2007. Advanced Solar Desalination: A Feasible Technology to the Mediterranean Area. White Paper Prepared for CIEMAT – Plataforma Solar de Almeria.

Block S.S. 1991. Disinfection, Sterilization, and Preservation, 4th ed., Lea&Febiger Pubs.

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Burns, R.T. and L.B. Moody. 2002. Phosphorus Recovery from Animal Manures using Optimized Struvite Precipitation. Proceedings of Coagulants and Flocculants: Global Market and Technical Opportunities for Water Treatment Chemicals. Chicago, IL.

Caslake L.F., D.J. Connolly, V. Menon, C. M. Duncanson, R. Rojas and J. Tavakoli. 2004. Disinfection of Contaminated Water by Using Solar Irradiation. Applied and Environmental Microbiology, February 2004, 70 (2), 1145-1151,

Cath T.Y., J.E. Drewes and C. Lundin. 2009. A Novel Hybrid Forward Osmosis – Reverse Osmosis Process for Water Purification and Reuse, using Impaired and Saline Water. Proceedings of American Water Works Association Membrane Technology Conference. April 2009.

CH2M HILL, 2002. Review of Alternative Wastewater Disinfection Technologies- White Paper. Prepared for CH2M HILL, August 2002.

CH2M HILL, 2007. Algae to Fuel: A Engineering Review, White Paper. Prepared for CH2M HILL, December 2007.

CH2M HILL, 2008. Evaluation of Reject Treatment Technologies, Technical Memorandum. Prepared for Eastern Municipal Water District. September 2008.

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CH2M HILL, 2010. Technical Memorandum-Evaluation of Sidestream Treatment Technologies for Ammonia or Total Nitrogen Removal Part 1: Description, Review, and Comparison. Prepared for Miami-Dade Water and Sewer Department. February 2011.

Christian, S., S. Grant, D. Wilson, P. McCarthy, D. Mills and M. Kolakowski. 2010. The ANMBR Process and the First Year of Full-Scale ANMBR Operation Treating Salad Dressing Wastewater. Proceedings of Water Environment Federation Membrane Application Conference and Exposition. March 2010.

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Daigger, G.T., P. Sanjines, K. Pallansch, J. Sizemore and B. Wett, B. 2011. Implementation of a Full-scale Anammox-based Facility to Treat an Anaerobic Digestion Sidestream at the Alexandria Sanitation Authority Water Resource Facility. Proceedings of the IWA/WEF Nutrient Recovery and Management: Inside and Outside the Fence Conference. Miami, Florida. February 2011.

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Faibish R.S., and Y. Cohen. (2001). Fouling-Resistant Ceramic-Supported Polymer Membranes for Ultrafiltration of Oil-in-Water Microemulsions, Journal of Membrane Science, 185, 129-143.

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Microbial Fuel Cells with an Improved Cell Configuration. Journal of Power Sources. 171(2), 348-354.

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Friese, D., R. Overstreet and G. Dobbeck. Membrane Biofilm Reactor Developments Benefit Multicontaminant Treatment Performance. Proceedings of Water Reuse Association California Section Conference and Exposition. March 2009.

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Cavitation Pilot Study for Controlling Cooling Water Quality. Proceedings of 79th Annual Water Environment Federation Technical Exposition and Conference. October 2006.

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Hancock N.T. and T.Y. Cath, 2009. Novel Performance Modeling of Forward Osmosis – Reverse Osmosis Integrated Systems. Proceedings of American Water Works Association Membrane Technology Conference. April 2009.

He, Z., Minteer, D. and Angenent, L. Electricity Generation from Artificial Wastewater Using an Upflow Microbial Fuel Cell. Environ. Sci. Technol., 2005, 39 (14), 5262–5267

Huehmer R. and F. Wang, 2009. Energy in Desalination: Comparison of Energy Requirements for Developing Desalination Techniques. Proceedings of American Water Works Association Membrane Technology Conference and Exposition. April 2009.



Jiang, D., E. Troop, K. Scheible, M. Curtis, D. Raymond and B. Li. 2010. High Power Recovery with Large-scale Multi-anode/cathode Microbial Fuel Cells Treating Wastewater. Proceedings of 83rd Annual Water Environment Federation Technical Exposition and Conference. October 2010.

Jiang, J.Q., and B. Lloyd. (2002). Progress in the Development and Use of Ferrate (VI) Salt as an Oxidant and Coagulant for Water and Wastewater Treatment. Water Research. 36, 1397-1408.

Joyce, E.; S.S. Phull, J.P. Lorimer and T.J. Mason. 2003. The Development and Evaluation of Ultrasound for the Treatment of Bacterial Suspensions. A Study of Frequency, Power and Sonication Time on Cultured Bacillus Species. Ultrason. Sonochem. 10 (6), 315-318.

Kim, J.R., Premier, G.C., Hawkes, F.R., Rodríguez, J., Dinsdale, R.M., Guwy, A.J. 2010. Modular Tubular Microbial Fuel Cells for Energy Recovery During Sucrose Wastewater Treatment at Low Organic Loading Rate. Bioresource Technology. 101 (4)1190-1198.

Koivunen, J. and H. Heinonen-Tanski. 2005. Inactivation of Enteric Microorganisms with Chemical Disinfectants, UV Irradiation and Combined Chemical/UV Treatments. Water Res. 39 (8), 1519-1526.

Kristen, K. 2007. Environmental Costs of Desalination. Environ. Sci. Technol. 41(16), 5576-5579.

Lattemann, S., Kennedy, M., Schippers, J. and Amy, G. 2010. Chapter 2 Global Desalination Situation, Sustainability Science and Engineering. 2, 7-39.

Lazarova V., Janex M.L., Fiksdal L., Oberg C., Barcina I. and Pommepuy M. 1998. Advanced wastewater disinfection technologies: short and long term efficiency. Water Science and Technology, 38, 109-117

Lefevre F., Audic J.M. and Ferrand F. 1992. Peracetic Acid Disinfection of Secondary Effluents Discharged off Coastal Seawater. Water Science and Technology, 25(12), 155-164.

Li, Xiang, B. Hu, S. Suib, Y. Lei and B. Li. 2010. Manganese Dioxide as a New Cathode Catalyst in Microbial Fuel Cells (MFC). Proceedings of 79th Annual Water Environment Federation Technical Exposition and Conference. October 2006.

Liu, H., Ramnarayanan, R. and Logan, B.E. 2004. Production of Electricity during Wastewater Treatment using a Single Chamber Microbial Fuel Cell. Environ. Sci and Technol. 38, 2281-2285.

Lin, N.H., M. Kim, G.T. Lewis and Y. Cohen. 2010. Polymer Surface Nano-structuring of Reverse Osmosis Membranes for Fouling Resistance and Improved Flux Performance. Journal of Material and Chemistry, 20, 4642-4652.

Loeb S. (1998). Energy Production at the Dead Sea by Pressure-Retarded Osmosis: Challenge or Chimera? Desalination 120: 247–262.

Logan, B.E., Aelterman, P., Hamelers, B., Rozendal, R., Schröeder, U., Keller, J., Freguiac, S., Verstraete, W. and Rabaey, K. 2006. Microbial Fuel Cells: Methodology and Technology. Environ. Sci. Technol. 40(17), 5181-5192.

Logan, B.E., Cheng, S., Watson, V. and Estadt, G. 2007. Graphite Fiber Brush Anodes for Increased Power Production in Air-Cathode Microbial Fuel Cells. Environ. Sci.Technol., 41(9), 3341-3346.



Mansell B., P. Ackman, C.C. Tung and P. Fu. 2011. Comparison of Nanofiltration and Reverse Osmosis Membranes to Produce High Quality Water for Indirect Potable Reuse. Proceedings of American Water Works Association Membrane Technology Conference and Exposition. March 2011.

McCutcheon J.R., R.L. McGinnis, and M. Elimelech. 2005. A Novel Ammonia-Carbon Dioxide Forward (direct) Osmosis Desalination Process, Desalination 174, 1-11.

Mehanna, M., Saito, T., Yan, J., Hickner, M., Xiaoxin, C., Huang, X. and Logan, B.E. 2010. Using microbial desalination cells to reduce water salinity prior to reverse osmosis. Energy Environ. Sci. 3(8), 1114-1120.

Metcalf and Eddy, 2003. Wastewater Engineering: Treatment and Reuse, 4th ed. McGraw Hill Publishing, USA.

Metcalf and Eddy, 2007. Water Reuse: Issues, Technologies, and Applications. McGraw Hill Publishing, USA.

Morris R. (1993) Reduction of Microbial Levels in Sewage Effluents Using Chlorine and Peracetic acid Disinfectants. Water Science and Technology, 27(3-4), 387-393.

Neis, U. and T. Blume. 2003. Ultrasonic Disinfection of Wastewater Effluents for High-Quality Reuse. Water Sci. Technol.: Water Supply, 3(4), 261-267.

Prieto, A. L., H. Futselaar, P. Lens, G. Amy and D.H. Yeh. 2010. Gas-lift Anaerobic Membrane Bioreactor (Gl-AnMBR): Preliminary Results from a Filterability Assessment. Proceedings of Water Environment Federation Membrane Application Conference and Exposition. March 2010.

Ried, A., J. Mielcke, M. Kampmann, T.A. Ternes and B. Teiser. 2004. Ozone and UV Processes for Additional Wastewater Treatment to Remove Pharmaceuticals and EDCs; Proc. IWA LeadingEdge Technologies Conf., IWA Publishing, 2004

Rittmann, B.E. 2007. The Membrane Biofilm Reactor is a Versatile Platform for Water and Wastewater Treatment. Environ. Eng. Res., 12, (4), 157-175.

Roeleveld, P., P. Loeffen, H. Temmink and B. Klapwijk. (2004). Dutch Analysis for P-recovery from Municipal Wastewater. Water Science and Technology, 49 (10), 191-199

Rodrıguez G. and Camacho G, 2001. Perspectives of Solar–Assisted Seawater Distillation. Desalination. 126, 213–218.

Salamero F. D. 2004. Modelling of Membrane Distillation Processes. Computer Aided Process Engineering Center, Department of Chemical Engineering, Technical University of Denmark, Denmark.

Salveson, A., N. Goel, M. Scott, P. McCole and C. Bergman. 2009. Preliminary Technology Assessment Effluent Disinfection Study for Six Kansas City WWTPs. Proceedings of 82nd Annual Water Environment Federation Technical Exposition and Conference. October 2006.

Scott, L., M Sivakumar, and H. Dharmappa. 2007. Optimising Membrane Distillation Using Hollow Fibres. Sustainable Earth Research Centre, Environmental Engineering University of Wollongong, Australia

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Sharma, V.K., F. Kazama, F., H. Jiangyong and A.K. Ray. 2005. Ferrates (Iron(VI) and Iron(V)): Environmentally friendly oxidants and disinfectants. Journal of Water and Health 3 (14), 117-125.

Soubhagya K. P., E. R. Hall and P. R. Bérubé, 2010. Study of Submerged Anaerobic Membrane Bioreactor (AnMBR) Treating Municipal Wastewater. Proceedings of 83rd Annual Water Environment Federation Technical Exposition and Conference. October 2010.

Srisawat, P., A.B. Streiffer, D.N. Barbeau, T.E. Wiese, D. Grimm, B.K. Skaggs, A.J. Englande, Jr., and R. S. Reimers. 2010. Reduction of Estrogenic Activity in Wastewater Following Treatment with Ferrate. Proceedings of 83rd Annual Water Environment Federation Technical Exposition and Conference. October 2010.

Tao G., B. Viswanath, K. Kekre, L.Y.Lee, H.Y. Ng, W.C.L. Lay and H. Seah. 2009. RO Brine Treatment by a Capacitive Deionization Based Process to Increase Water Recovery. Proceedings of 13th Annual Water Reuse and Desalination Research Conference. May 2009.

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STRATEGIC STUDY

Chapter 3: Public Education and Awareness to Promote Recycled Water Use

3.1 Introduction Water scarcity and sustainability is emerging as a global issue and is being acknowledged at high-profile gatherings of world leaders, including the United Nations World Summit on Sustainable Development, the Global Water Forum in Kyoto, and the Copenhagen Climate Change Conference. It was also a focus of the 2011 Gulf Environment Forum held in KSA.

In KSA, potable water is produced from either non-renewable or very slowly renewable water resources such as groundwater and through expensive and energy-intensive desalination of seawater or other purification processes for saline water sources. Much of the potable water produced from these costly sources is used for non-potable purposes, and these sources cannot sustainably meet the future potable and non-potable water demands.

Water reuse is an essential component of integrated water resources management and sustainable development, especially in water-scarce regions, and is a rapidly growing trend. In many of the largest cities in KSA, water is reclaimed by advanced treatment and then used in urban settings, primarily for landscaping and irrigation. The use of reclaimed water in industrial settings is increasing, and additional markets are developing. Figure 3-1 depicts the current and projected use of reclaimed water, by type.

However, developing these markets and fully realizing the potential for reclaimed water usage will depend on understanding current barriers and then building public understanding, trust, and support for reuse in KSA. This point is reinforced by Troy Hartley in his presentation at the International Conference on Integrated Concepts on Water Recycling in 2005. While water reuse has been demonstrated to be a viable solution for water scarcity in countries like USA, Singapore, and Australia, reuse projects have failed in the recent past in some countries because of lack of public acceptance. Public acceptance must be grounded in the broader context of water resources management, but also with attention to the issues and needs specific to reuse.

To establish a greater understanding of water resource issues, the Saudi Water Act (MOWE, 2010) provides that MOWE, in coordination with the MOA, Ministry of Education and Ministry of Higher Education, Ministry of Islamic Affairs, and Ministry of Culture and Information, is responsible for preparing an effective water education strategy. This strategy must promote a culture in which the population is aware of water-related problems and challenges and is capable of addressing them.

This purpose of this chapter is to identify potential barriers to reuse and to outline policy (infrastructure investment, regulations and enforcement and pricing), public education, and outreach activities that can be employed to create an environment favorable to expanded reuse.

CHAPTER 3: PUBLIC EDUCATION AND AWARENESS TO PROMOTE RECYCLED WATER USE

3-2 STRATEGIC STUDY

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0 M

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FIGURE 3-1 Total Existing and Projected Future Reuse Use by Type in KSA Reference: ItalConsult (2009-2010)

The information provided in this chapter is intended to complement what currently exists in the Saudi Water Act, but is specifically intended to focus on activities related to the need for additional reuse in the future.

3.1 Barriers to Reuse Implementation in KSA 3.1.1 Technology, Infrastructure, and Public Trust In many of KSA’s cities, current WWTP design capacity is only half of the potable water demand. As discussed in Chapter 1, only 40 percent of the wastewater is collected through the sewer network and tankers and treated in WWTPs due to limitations in the wastewater treatment network and WWTPs. The wastewater treated to a secondary or higher level is approximately 78 percent of the limited treatment capacity. Only about 62 percent of the 2.56 million M3/day of wastewater treated in KSA is collected through sewers and the remainder is collected in septic tanks/cesspits and taken by trucks to the WWTPs. Soak pits are still being operated, allowing the sewage water to percolate and pollute the groundwater. Tertiary treatment with UF and RO membranes that can produce very high quality recycled water are yet to be adopted at KSA’s major WWTPs; however, planned facilities would incorporate tertiary treatment. In addition, KSA does not yet have an established distribution network to supply recycled water to end users. Recycled water is currently being distributed primarily through trucks.

The limitations in the advancement of water reuse can be summarized as follows:

• The existing infrastructure is lacking in wastewater treatment capacity.

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STRATEGIC STUDY 3-3

• Sewer systems are leaking and the overall infrastructure network lacks sufficient connectivity and advanced treatment plants to increase recycled water availability at higher quality.

• Aging WWTPs are producing recycled water of inadequate quality.

• There is no network to distribute high-quality recycled water to end users.

• Generally, the public has often been unclear about the difference between municipal wastewater, grey water, and recycled water. However, the public is aware of being adversely affected by the pollution caused by the lack of wastewater collection or when the existing municipal WWTPs dump poor quality effluent into the environment. Additionally, there is a lack of credible information about (1) the types of treatment processes available and the capability of WWTPs to produce recycled water meeting government standards and (2) the quality of recycled water that is recommended for various applications. The result is fear of using the recycled water due to beliefs that such use would result in health problems

• In order to meet the stated reuse objectives and build public trust, KSA must make prioritized investments in wastewater collection, treatment, and distribution and share relevant information about appropriate treatment processes to ensure the protection of public health.

3.1.2 Socio-Cultural Beliefs and Religious Practices The KSA public generally has a negative opinion about recycled water. Saudi Arabians use potable water for ablution, which is a religious ritual carried out before prayer, and many believe that use of recycled water will invalidate their ablution, even though the recycled water is free from impurities and, according to the religious guidelines, can be used for ablutions. (This has been the major factor in slowing the acceptance of recycled water.)

Many countries have considerable Muslim populations that have benefitted from using recycled water. In these countries, fatwas have been issued to clarify that using recycled water for ablution (and even drinking) is acceptable, provided the water meets the specifications established. In KSA, the Council of Leading Islamic Scholars issued a fatwa in 1978 stating that recycled water can be used for ablution and drinking, provided that it is sufficiently and appropriately treated to ensure good health. A translated excerpt from the fatwa is reproduced below:

According to the report prepared by the experts in this regard, a large body of water would be pure from any impurity if such impurity is removed, if more water is added to it, or if such impurity is eliminated by the passage of time, the sun, the wind, or any other cause that would remove its impurity. Impure water could be purified by modern filtering techniques that are the best and most efficient methods for purification, in which many materials will be added to remove impurities and certified by the water treatment experts. Therefore, this Council believes that such water will be totally pure and may be used for ritual purification and drinking as long as there are no negative consequences to health. If drinking is to be avoided, it is merely for reasons of public health and safety, not because of any ramifications of Islamic Law.

The following actions will help change religious perceptions and will be included in the outreach activities:

• Publicize the fatwa issued in 1978 approving the use of recycled water and invite many Islamic scholars to support and promote this change.

• Encourage the Council of Leading Islamic Scholars in KSA to publish additional fatwas that promote the use of recycled water.


3-4 STRATEGIC STUDY

• Conduct mosque programs to clarify to the public that recycled water is a safe and valuable resource.

• Engage and feature religious scholars in TV, radio, and other programs explaining that recycled water can be treated to achieve high purity levels.

• Issue statements of religious scholars approving use of recycled water in newspapers and on TV, radio, and public displays.

• Conduct debates on recycled water in religious seminars.

3.1.3 Public Perceptions and Terminology In KSA, there is significant reluctance to using recycled water even for irrigation and industries. Research conducted in Singapore, Australia, and USA also indicates that reuse projects have a high risk of public rejection, in part because of the words and images used to explain such projects. The words used to describe recycled water have great power. From the surveys conducted in Australia and USA, it was observed that derivatives of the word pure (such as purer than, purity, and purified) tend to reassure people that water is safe to be returned to the drinking supply. Key findings from the research conducted by the WateReuse Research Foundation are summarized below (Macpherson and Slovic, 2011).

• Lack of knowledge is the major reason for public opposition to water reuse projects. It has been observed in USA, Singapore, and Australia that information provided on wastewater treatment increased public understanding of water quality and treatment and willingness to use recycled water for agriculture and industries. Providing easily understandable technical details explaining the treatment process stages, the terminology used, the quality of water achievable through treatment, and the effects of various constituents in the recycled water had a positive effect on public perception, including an increasing tendency to trust the process and accept reuse. During the surveys, the public agreed that transparency is vitally important to establishing trust and that the information should be available in an easy-to-understand, accessible format for those who are interested.

• The words wastewater and sewer tend to dissuade people from using recycled water, probably because of the negative connotations of the terms sewer, sewage, and waste. In one project, managers posted a sign reading Recycled Water: Do Not Drink. Unfortunately, more than half of the survey respondents interpreted that phrase to mean that recycled water should never be used for drinking, which indicates that the sign was having adverse, misleading effects on reuse projects.

• Media coverage also has a powerful effect on public perceptions of reuse. Specifically, media treatment of the health impacts of trace organic contaminants (and similar contaminant-related stories) may convey scientific information in a way that exaggerates, dramatizes, or distorts scientific information. Coverage can also use stigmatizing language that politicizes or sensationalizes the story. These types of stories can lead to confusion among the public about the role of pharmaceuticals and personal care products in water systems. Sensational media coverage, phrases, and images play a strong role in shaping the public’s image of reuse. In some cases, readers draw conclusions from headlines rather than reading the actual publication.

• Issues defined as emerging or new tend to create more concern than others. Although water reuse is not new, the opportunities and the technologies available are not well known. In addition, the terminology is sometimes inconsistent and emphasizes the source of the water (wastewater) rather than its quality (resulting from advanced technology and monitoring).


STRATEGIC STUDY 3-5

Challenges in educating people in KSA on recycled water are listed below:

• The public’s understanding of water science is generally poor.

• Approaches to project communication must feature easily understood images and words that simply, clearly, and convincingly explain water and wastewater quality and treatment to the public.

• The water community must determine (1) how levels of water treatment can be explained effectively, (2) how to adequately explain the nature of recycled water in a way that leads to public acceptance of its safety, (3) how increased knowledge of water quality and treatment can be used to improve acceptance, (4) what types of information the public needs to understand how water can be treated, managed, used, and reused, and (5) what words and images can be used to improve public acceptance.

• An understanding of how branding can help promote reuse is needed.

• The public has received inconsistent and misleading messages in the past. Due to the sensitive nature of the subject, the overall approach and a water recycling glossary must focus on communication techniques that will boost success. A new, consistent vocabulary that can be used to explain management of water may prevent public rejection of otherwise technically valid strategies and could contribute to the success of reuse projects.

• The public must be educated about potential health and environmental risks associated with recycled water use without receiving negative, misleading messages.

• Knowledge and understanding of water quality gained through exposure to simple and easy-to-understand information are the keys to acceptance of water recycling. Viewing a clear, short presentation from a knowledgeable presenter, coupled with a visual, interactive explanation of the technology with examples of water recycling around the world, increases the acceptance of water recycling. In a NEWater Explorer program in Singapore the presentations overall received positive comments, particularly the tutorials. Participants noted that the graphics (especially the graphic that magnified the RO membrane 100 million times) clearly communicated how membranes work to protect public health.

• Survey respondents indicated that lack of knowledge about wastewater treatment processes is the main reason for the public’s negative opinions toward reuse projects, whether for potable or nonpotable use, rather than lack of trust.

• Respondents indicated more concern about the risk to human health and the environment from climate change and smog than from pharmaceuticals detected in trace amounts in drinking water. They were somewhat more concerned about plasticizers found in water bottles than pharmaceuticals. When the word microconstituents was used, it rated as a lower concern than pharmaceuticals or plasticizers found in water. Researchers assumed this is because the word microconstituents is not understood to include both pharmaceuticals and plasticizers.

• Respondents were not particularly opposed to reusing water that has been used by humans, but they were broadly opposed to reusing water that has been in a sewer. There appears to be a lack of understanding that water in a sewer includes water that has been used by people as well as other water that enters the sewer, such as stormwater, inflow, and infiltration. The words and images associated with sewers, toilets, and waste have been observed to create a very negative impact among the public.

• The best way for the water community to proceed is (1) to make sure that the full urban water cycle story is told so that the public receives accurate information and (2) to


3-6 STRATEGIC STUDY

partner with the media early in a project’s planning stage and frequently throughout the process.

Approaches to project communication must feature easily understood images and words that simply, clearly, and convincingly explain water and wastewater quality and treatment to the public.

If such a study were conducted in KSA, similar observations would be expected. In designing the Public Education, Outreach, and Awareness Program for KSA, lessons learned from previous work will be used to enhance program success.

3.1.4 Water Tariffs in Middle East Pricing policy is one of the main driving factors for water reuse or lack thereof. Water tariffs are set based on a number of formal criteria defined by law, as well as informal criteria. Formal criteria typically include one or more of the following:

• Financial criteria (cost recovery) • Economic criteria (efficiency pricing based on marginal cost) • Environmental criteria (incentives for water conservation)

Social and political considerations often are also important in setting tariffs. Tariff structures and levels are influenced in some cases by the desire to avoid an overly harsh burden on poor users or by other political considerations. Water tariffs should be easy to understand for consumers. This is not always the case for the more complex types of tariffs, such as increasing-block tariffs and tariffs that differentiate between different categories of users.

The potable water tariff in KSA is the lowest in the region. Due to huge pervasive subsidies for potable water in KSA, though the production and transmission cost is close to SR 6 per m³, the delivered potable water cost to the public is close to only SR 0.15 per m³. This low-cost potable water has resulted in high per capita consumption of potable water in KSA and has not provided incentives for the public to use recycled water. Until pricing structures for potable and reuse water are revisited, the public (and targeted reuse customers) will not be financially incentivized to replace current potable usage with reuse water. Reuse water must not only be safe and reliable, it must also be cost-competitive.

MOWE has recognized this fact and is addressing the price issue related to potable water and recycled water in the draft Saudi Water Act. Further discussion of the business case related to reuse opportunities is presented in Chapter 4.

3.1.5 Water Resource Management Structure Including water reuse as an essential component of integrated water resources management and sustainable development is a growing trend around the world, not only in water-deficient areas but also in water-abundant regions. Numerous countries have established water resources planning policies based on maximum reuse of urban wastewater. KSA currently has several regulating entities covering different aspects of reuse regulations. This can be confusing for the public and result in regulatory gaps in planning and enforcement. Regulations are discussed further in Chapter 7.

Regulating agencies in KSA are:

• Presidency of Meteorology and Environment (PME) • MOWE • Saudi Arabian Standards Organization ( SASO) • Royal Commission for Jubail and Yanbu (RCJY) • Saudi Aramco

PME regulates water quality standards for:

http://en.wikipedia.org/wiki/Marginal_cost

http://en.wikipedia.org/wiki/Water_conservation


STRATEGIC STUDY 3-7

• Pretreatment guidelines for discharge to central treatment facilities • Receiving water quality • Performance standards for direct discharge • General environmental law and its implementation procedures

MOWE regulates the following:

• Treated wastewater and its reuse regulations and implementation, including reuse for agricultural purposes, industrial purposes, aquifer injection, municipal reuse, recreation, and fish aquaculture.

SASO water quality standards regulate:

• Bottled drinking water • Non-bottled drinking water (which includes physical, biological, and microbial

characteristics)

The following water quality regulations are applicable to areas within the RCJY:

• Ambient Water Quality Standards for Receiving Waters in Coastal Areas

• Effluent Standards for Direct Discharge

• Standards for Pretreatment and Discharge of Pollutants from Regulated Industrial Wastewater Sources

• Standards for Discharge to Irrigation Systems

• Ballast Water Discharge Standards

• Potable Water Quality Standards

Agricultural reuse is often a first target of reuse planning, as it is in KSA. Reuse in agricultural applications is currently practiced today in almost all arid areas of the world. In many regions, particularly in developing countries in Asia, Africa, and Latin America, unplanned use of inadequately treated wastewater for irrigation of crops continues and is often confused by the public with planned and regulated reuse. This major health concern makes it imperative that governments and the global community implement proper reuse planning, management, and regulations emphasizing public health and environmental protection, during this era of rapid development of wastewater collection and treatment systems. To allow systematic planning, investment, and protection of public health as reuse expands in KSA, a management structure focusing on reuse should be explored.

3.1.6 Regulations and Recycled Water Quality Water reuse standards or guidelines vary with the type of application, the regional context, and the overall perception of risk. Depending on the project specifications, there will be different water quality requirements, treatment process requirements, and criteria for operation and reliability. (Details concerning water reuse standards and guidelines are presented in Chapter 7.) However, the starting point for any water reuse project for any application is ensuring public health and safety. For this reason, microbiological parameters have received the most attention in water reuse regulations. Since monitoring for all pathogens is not realistic, specific indicator organisms are monitored to minimize risk.

Different countries have developed different approaches to protecting public health and the environment, but the major factor in choosing a regulatory strategy is economics, specifically the cost of treatment and monitoring. Most developed countries have established conservatively low risk guidelines or standards based on a high-technology/high-cost approach, such as the California (USA) standards. However, high standards and high-cost


3-8 STRATEGIC STUDY

techniques do not always guarantee low risk because factors such as insufficient operational experience, operation and maintenance (O&M) costs, and regulatory control can have adverse effects. A number of developing countries advocate another strategy for controlling health risks by adopting a low-technology/low-cost approach based on the World Health Organization (WHO) recommendations. Further discussion of reuse standards is presented in Chapter 7.

In spite of the economic and ecological advantages associated with water recycling, the key issue remains public health and safety. The reuse of untreated wastewater, still widely practiced in several regions in nations such as China, India, Morocco, Egypt, Pakistan, Nepal, Vietnam, and most of South America, leads to enteric diseases, helminthic infections, and dangerous epidemics (USEPA, 2004). In addition to public health risks, insufficiently treated effluent may also have detrimental effects on the environment. For example, high salinity levels in effluent can lead to a decrease in productivity for certain crops and destabilization of the soil structure. Another possible adverse effect is groundwater pollution.

The Ministry of Agriculture and Water passed Royal Decree M/6 in 1999 with regulations encouraging reuse of treated wastewater for agriculture. Though many Royal Decrees have been issued in KSA and the MOA has issued regulations in the form of ROI, they have not been strictly enforced. Consistency of enforcement and associated standards is currently an issue in KSA and should be addressed if public trust of recycled water is expected to increase. Further discussion of this issue is provided in Chapter 7.

3.2 Proposed Policy, Public Education, and Awareness Actions to Promote Recycled Water Use

The following recommendations are intended to address the barriers to successful implementation of reuse plans in KSA. While the majority of the proposed actions are specific to public education and awareness, the actions also include suggestions to address organizational and leadership barriers, financial incentives, and innovative applications of technology.

3.2.1 Organization and Leadership Recycled Water Hub A Recycled Water Hub will be formed to provide a strategic platform for leveraging the development of water reuse technologies, learning, and networking. Positioning itself as a center for recycled water excellence, the Recycled Water Hub can serve as a launching pad for both local and international water treatment companies that are eager to capitalize on the business and research and development (R&D) opportunities in KSA.

The Recycled Water Hub will strive to be:

• Primarily an R&D incubator center to find more competitive, innovative, and efficient technologies for use of recycled water

• Secondarily (1) an institute for advanced learning for recycled water professionals (2) a knowledge and networking hub, and (3) a link between industry, water treatment companies, and utilities

Leading international companies like Siemens, Nitto Denko, and GE will be encouraged to set up bases and laboratories at the Recycled Water Hub. With the analytical lab services, close proximity to test sites, and access to R&D funding and technologies, the Water Reuse Hub can drive the development of more competitive, innovative, and efficient technologies in the water reuse sector.


STRATEGIC STUDY 3-9

Steering Committee A Steering Committee of knowledgeable, influential decision-makers, who can effect changes in laws, regulations, restrictions, implementation, and enforcement, should be formed under MOWE to analyze the new requirements and draft policies and procedures to assist MOWE in establishing new policies. The committee would also work to increase the momentum toward water reuse and would consist of representatives from:

• NWC • Ministry of Religious Affairs • Ministry of Education • Ministry of Health • MODON • MOA • KAUST • King Abdulaziz City for Science and Technology (KACST) • Chambers of Commerce • PME • Business Community • Non-governmental organizations (NGOs) such as the Saudi Arabian Water &

Environmental Society

The committee would be responsible for reviewing and approving the promotional public awareness and education campaign materials, including documents, posters, TV clips, presentations, seminars, etc., for recycled water.

3.2.2 Incentives and Penalties Incentives provided by government to the people who directly or indirectly use recycled water for an industry, farm, or building will encourage more people to use recycled water. The incentives can be in the form of providing one or more of the following:

• Power provided on priority • Water connection provided on priority • Industrial/municipal license provided on priority • Subsidy in the form of a percentage of the cost of the recycled water infrastructure • Cash incentives

The government should consider the use of penalties to discourage people from discharging wastewater to the network and using freshwater, where recycled water can be used. The penalties and other actions should be most or all of the following:

• Set policies and regulations to promote a water reuse environment.

• Establish drivers (incentives and penalties) for accepting the change to using recycled water.

• Set wastewater collection charges that are much higher than charges for potable water.

• Impose very high charges for granting approval to drill wells for agriculture where a recycled water connection is available in the vicinity.

• Withhold permission for constructing or operating an industry or decline to renew the commercial registration.

• Withhold a power connection and discontinue the power connection to those who do not comply with the regulations.

• Impose a penalty (including imprisonment in extreme cases) for violations.



• Encourage both public and private sectors to take joint ownership of efforts to maximize water reuse.

3.2.3 Surveys and Research A series of surveys and focus groups will be conducted to better understand the public’s level of knowledge about water resources, including both water and wastewater treatment, as well as levels of trust, knowledge, and experience with recycled water. Since public resistance to water reuse is a known fact, the surveys will focus on determining the factors driving resistance to reuse. The primary objective will be to evaluate how the terminology used to describe recycled water may have affected outcomes. The secondary objective will be to examine how education and knowledge about recycled water relate to public acceptance. A third objective will be to test different “delivery models” for how best to increase public acceptance of reuse. Few researchers in developed countries have taken a holistic view of the topic of reuse to ensure that the conversation focuses on the costs and benefits of a particular project in a water cycle context.

Surveys conducted in the USA and Australia suggest that the yuck factor (a term used to describe negative reactions) does affect the public’s acceptance of reuse projects (Macpherson and Slovic, 2011). Educating the public about the water cycle, treatment technologies, and the safety of recycled water can help to overcome these negative reactions and foster acceptance.

The surveys will be both quantitative and qualitative, covering different demographic sectors, including industries and agriculture. The survey team will review surveys conducted in other countries. The survey questionnaires can be used for reference and modified to suit the Saudi Arabian culture. The surveys can be conducted individually or collectively in a group during seminars or even by telephone. However, individual surveys and group surveys tend to produce more reliable results than telephone surveys. These surveys will enable the water community to use proper terminology in the communication and refine the overall strategy for the Public Education, Outreach, and Awareness Program.

3.2.4 Key Messages and Implementation Approach Using information obtained from the research and other sources, “key messages” pertaining to all aspects of reuse will be developed. The purpose will be to illustrate the need for KSA to pursue water reuse to achieve both economic benefits and environmental improvements. It is envisioned that these key messages will address technical, economic, environmental, social, safety, and religious issues, such as those listed below:

• KSA faces water-related stress and has had to make huge investments in desalination plants (as discussed in Chapter 1) and pipelines to distribute an adequate quantity of safe and clean water.

• Benefits associated with water reuse include savings from not having to develop new water sources, reduced treatment requirements, and the economic value of the recycled water.

• Recycled water is available in different levels of water quality for different applications due to the higher cost associated with higher degrees of purification.

• The treatment cost of desalinated water is higher than the cost of producing recycled water.

The general Saudi public will pay attention if they understand that future generations will be adversely affected by a continued dwindling of groundwater levels and continued high costs of desalinated water production.



Religious perceptions are deeply rooted in the Saudi people. New concepts must be introduced and explained clearly and systematically. Therefore a phased approach to implementation of reuse is suggested. Implementation phases may be as follows:

• Phase 1: Agricultural and industrial applications, possibly toilet flushing

• Phase 2: Treated grey water for ablution and cleaning

• Phase 3: Injecting recycled water to limit saltwater intrusion and replenish groundwater reserves

• Phase 4: Indirect potable use by injecting recycled water into aquifers that are not in direct proximity to a drinking water supply

A stepwise approach such as this fosters public trust through proven reuse applications that are cost-effective, successful, and safe. As public trust grows, implementation of the subsequent phases will be easier. A coordinated Public Education, Outreach, and Awareness Program will accompany these phases of implementation to foster support and extend the base of support, based on reliable information. Chapter 5 more fully addresses the proposed implementation approach related to Phases 3 and 4.

3.2.5 Branding Recycled Water As noted above, according to surveys conducted in Australia, Singapore, and USA, the words wastewater, sewage, and sewer deter people from using reuse water. It has also been observed that the word pure and its derivatives reassure people that water is safe. Since the words used to describe recycled water have great power, it is essential that the recycled water be re-branded. This has been done successfully in Singapore, where the recycled water for potable application was re-branded as NEWater (PUB, 2011). Positive terms could be used, such as ‘Essential Water’ ‘Clear Water’ (proposed by MOWE) and Tahir, which means water without any smell, color, or taste that can be even used for any religious purpose.

The survey described in Section 3.2.3 will be used to measure how favorably the public responds to using “Essential Water/Clear Water” and Tahir, or other terms being considered to re-brand reuse. For the purposes of this Strategic Study, the term Tahir is used; however, the final choice for branding should be selected based on the outcome of the survey. Simultaneously, an open competition could be conducted through newspapers inviting people to suggest a suitable name for recycled water and win a cash award. Branding recycled water and building trust should gradually change the public perception from negative to positive. The outcomes of this effort are expected to be:

• Establishment of a brand for recycled water with a suitable name (similar to NEWater in Singapore) that emphasizes its quality and purity, accompanied by publicity so that the end product is seen as a valuable commodity.

• Incorporation of the new brand in all discussions (verbal, written, virtual, technical, and public) on reuse. This will help shift the public focus from primarily the origins of the water to its suitability and benefits of use.

3.2.6 Build Technical Knowledge The terms describing wastewater treatment are most often used inconsistently, such as preliminary, primary, secondary, advanced secondary, tertiary, advanced tertiary, and advanced treatments. Also, terminology used in communication has a major effect on public acceptance. The definitions in publications by the American Water Works Association (AWWA), Water Environment Federation (WEF), and other water organizations are too technical for the general public. John Ruetten’s Best Practices for Developing Indirect Potable Reuse Projects: Phase I Report (2004) provides value-based and communication best practices and includes case studies to illustrate each of these practices.



A set of terms that are understandable (a glossary) will be developed to communicate with the public. The terms in the glossary will be accurate but not written for engineers, scientists, and other water professionals. In the interest of consistency, all communications in the Public Education, Outreach, and Awareness Program will use the terms from the glossary as well as the re-branded terminology for reuse.

Using easy-to-understand terminology, education programs will be aimed at increasing awareness of the effectiveness of different treatment technologies. For example, instructors can demonstrate that technologies such as MF/UF and RO technologies, can treat wastewater to a level that is as pure as bottled water. Chapter 2 discusses these technologies in detail.

Materials will be created to fully explain the treatment processes, effectiveness, application and other information. Specifically, these documents will do the following with the intent of increasing understanding of technical processes, thereby building trust in reuse.

• Explain the water cycle and the significant role of reuse in the cycle. Figures 3-2 and 3-3 are examples of information that could be developed; specifically, they show the water cycle as typically depicted and the water cycle that is more representative of the cycle in KSA, respectively.

FIGURE 3-2 Water Cycle as Typically Depicted

• Describe processes used for treating wastewater in simple language using the terminology in the glossary and explain the quality of water achievable in each process. Summarize the costs associated with achieving various qualities of water.

• Explain Saudi regulations concerning the quality of water for various applications and compare with international regulations.

• Identify pathogens and viruses associated with recycled water and their maximum permitted level in various applications. Discuss safe and unsafe levels relative to human health.

• Describe quality control measures undertaken in the treatment process to ensure that the targeted quality is achieved.

• Discuss safety measures built into the system in case of process upsets to ensure that water that does not meet required quality standards never enters the distribution system.



Summarize the non-monetary benefits of reuse, such as improved environmental quality and public health, reduced discharge of nutrients to receiving waters, lower drinking water production costs, and creation of additional recreational opportunities.

FIGURE 3-3 What the Future Might Hold with Enhanced Urban Water Reuse Modified Water Cycle Developed by WateReuse Research Team - Adapted and used from “Talking About Water” (WRF-07-03), Copyright 2011, with permission from the WateReuse Research Foundation.

• Present data from various countries demonstrating benefits of using recycled water.

• Explain the benefits of nutrients in recycled water that could be used by crops and thus reduce fertilizer requirements on farms.

In addition to the information contained in the materials described, the following approaches will also be useful in increasing public knowledge about reuse and related technologies:

• Organize seminars, workshops, and other events to educate the public on wastewater treatment processes, quality standards, and quality assurance procedures associated with recycled water, and the social and economic responsibility to promote water reuse.

• Conduct debates on water reuse with public participation so that pros and cons of water reuse can be examined and thus address concerns about water reuse.

• Familiarize the public, especially industry leaders, with the processes used by conducting tours of recycled water production facilities.



3.2.7 Demonstration Projects The purpose of developing innovative demonstration projects is to bring the public closer to water treatment and reuse projects and create confidence in the use of recycled water.

A project in Jordan included the study, plan, design, and construction of two proven, low-cost, low-maintenance WWTPs for small communities. The community was actively involved in the activities and will operate and maintain the treatment plants and resulting reuse water in a safe and sustainable manner. Building community involvement into the planning, decision-making, and operations builds understanding and support for appropriate wastewater technologies (USAID, 2004).

Additional projects could include the following actions:

• Develop public parks with lawns, colorfully illuminated fountains using recycled water, and signs to inform the public about recycled water.

• Develop lakes using recycled water. Water bikes, ski boats, etc., could be made available to the public for rental to increase their comfort level with recycled water

• Develop a recycled water lake into a wetland that would attract international attention as Nakheel is doing in the International City, Dubai. Nakheel developed this innovative idea of developing a sustainable wetland using recycled water when birdwatchers discovered a wide variety of bird species, including indigenous, migratory, and endangered species visiting Al Warsen Lake, which was formed from the excess recycled water pumped into the quarry pits from the Dubai Municipal Sewage Treatment Plant.

3.2.8 Encouraging Urban Agriculture and Vertical Farming The Food and Agriculture Organization of the United Nations (FAO) defines urban agriculture as an industry that produces and processes food, largely in response to the daily demand of consumers within a town, city, or metropolis, applying intensive production methods to yield a diversity of crops. Urban agriculture ensures access to fresh vegetables, fruits, and food security to city dwellers. This results in an increase in entrepreneurial activities and the creation of job opportunities, as well as reductions in food cost due to the avoidance of transportation costs. Using high-density urban farming, for instance in vertical farms or stacked greenhouses, many environmental benefits can be achieved on a city-wide scale that would be impossible otherwise. With a little effort and investment, rooftops can contribute to improving families’ quality of life and provide them with healthy food. This practice can also raise their income, in addition to its environmental and aesthetic role.

Public Parks with Water Features



Lawn maintained using recycled water Illuminated fountains using recycled water

Lake with birds Lake with recreation

Artist’s Rendering of Lake Development

Urban agriculture will be promoted with recycled water. This will be helpful in making use of the recycled water that will be available in abundant quantities from the WWTPs in the cities. In addition, there will be no need to transport the recycled water to farming areas in villages away from the city. By encouraging urban agriculture with recycled water, government should be able to replicate the success achieved by TEI.

Vertical farming seems to be one of the best options for urban farming where land availability is limited. If successfully implemented, this practice can use recycled water and offer the promise of urban renewal, sustainable production of a safe and varied food supply (year-round crop production), and the eventual repair of ecosystems that have been lost in the



cities. However, the cost and overall economics of vertical farming must be reviewed in each location to confirm its feasibility under site-specific conditions.

3.2.9 Exhibitions and Knowledge and Information Centers Exhibitions and knowledge centers offer “hands-on” learning about water resources and reuse. The following actions could be taken as part of exhibitions and knowledge centers:

• Include interactive participation in exhibitions and knowledge centers.

• Design knowledge centers so that visitors, especially students, understand the need for reuse.

• Explain how and where recycled water can be used—examples include agriculture, industry, drinking water, aquaculture, aquifer storage, groundwater recharge, car washing, toilet flushing, and fodder. Discuss the differences between direct and indirect use of recycled water. Describe its importance in reducing the investment in expensive desalination plants.

• Provide visitors with information about the value of wastewater as a resource that can contribute to the nation’s development. Provide TV presentations, scale models, and short films to the Knowledge and Information Center to educate visitors about how proper processing of wastewater can generate bio-gas/power, manure for irrigation, and water.

• Develop illustrations/presentations for the Knowledge and Information Center describing the successful experience of developed nations with water reuse.

• Develop interactive computer programs with graphics and illustrations to explain the various stages in wastewater treatment (coagulation, flocculation, clarification, sludge removal and thickening, anaerobic treatment, anoxic treatment, aeration, filtration, MF/UF membranes, MBR, RO, disinfection with chemicals and UV treatment, etc. Examples of graphics from the NEWater Explorer program are shown in Figure 3-4.

• Develop 3-D models illustrating various advanced wastewater treatment facilities and the equipment involved.

• Show and explain the various quality checks that are conducted (and the equipment used) before recycled water is conveyed out of a treatment plant.

• Develop a presentation listing potential health risks associated with recycled water in agriculture, industry, aquaculture, aquifer storage, groundwater recharge, etc. and the processes used to minimize such risks.

• Design a computer program that simulates quality audits in recycled water facilities.

• Make technical experts available in the Knowledge and Information Center to address any questions or concerns raised by the public.

• Circulate fliers and pamphlets among the public to enhance awareness of recycled water. Mass Media and Public Outreach

3.2.10 Mass Media and Public Outreach In addition to the targeted techniques previously described, the Public Education, Outreach, and Awareness Program will also include a mass media component. As part of this effort, communication tools such as printed documents, posters, a website, TV and radio broadcasts, and newspaper articles will be developed. Social events and social media will also be used to convey positive messages about recycled water.



FIGURE 3-4 Screen Captures from NEWater Computer Program (PUB, 2011)

3.2.11 Website A website known as Tahir (or other name corresponding to branding choice for recycled water) will be developed exclusively to promote recycled water. MOWE and NWC websites will include links to Tahir. This website will be a Knowledge and Information Center on recycled water and all information will be available in English and Arabic. The site will be user-friendly, similar to the Singapore Public Utilities Board (PUB) website. The site will present the following:

• Virtual tour of wastewater treatment and recycled water production processes

• Frequently asked questions (FAQ) and responses

• A simple method for users to raise questions and receive responses

• Scrolling frames showing various recycled water applications and a simple method for going to the desired application page

• Current news regarding recycled water

• An online weekly magazine, also called Tahir, which publishes information on recycled water (could be automatically forwarded to registered subscribers)



• Videos of speeches given by religious scholars on recycled water

• Fatwas, regulations, incentives, and penalties related to recycled water

• TV clips and media campaign items from other countries that have pioneered recycled water, modified if necessary to make them suitable to reach KSA public (including children)

• Connections with social media forums

• Webinars

• Online discussion forums

• Testimonials and success stories concerning recycled water usage worldwide

Example screen shots of sample webpages from the NeWater project in Singapore are shown in Figure 3-4. The website includes example information from other reuse sites, provides interactive demonstrations on technology, and familiarizes viewers with treatment processes to create understanding and build confidence.

3.2.12 Media Relations A spokesperson will be identified and will coordinate with various government agencies and the Steering Committee, issue statements to the media, and serve as the liaison with the media. This person will be responsible for building relationships with reporters and editors, will re-brand reuse with the media, will promote stories to help convey positive reuse messages, and will enlist appropriate content experts. Additional activities may include:

• Host media tours of WWTPs to explain the system, processes, and quality control procedures used, enabling media representatives to publish and broadcast positive stories.

• Distribute the recycled water glossary to media representatives to prevent confusion over terminology. Explain the negative effect of using certain words and images (see Section 3.3.1) so that they avoid them.

• Provide TV clips and media campaign materials from other countries that have been pioneers in water reuse so that they can be modified and used to suit the Saudi culture.

• If required, provide training to media representatives.

• Develop slogans or “tag lines” on water reuse (similar to the water conservation slogan Conserve, Value, and Enjoy) to be used in the media campaign.

• Co-ordinate mosque programs with media so that they are covered in the press and on TV and radio.

• Periodically develop and distribute press releases and advertisements to publicize significant events.

As part of overall media promotion, a sand clock vessel (hourglass) was developed in association with the Max Vision advertising company. The hourglass was filled with water and sparkling particles (glitter) and fitted with a filter at the neck. During one cycle, the water drops from the top part of the vessel to the bottom and mixes with the glitter (depicting water getting dirty when used). Then in the reuse cycle, the hourglass is turned upside down. The water passes through the filter (leaving the glitter behind) and is collected at the bottom as clean water (showing how the water treatment process removes the dirt). Photographs of campaign visuals are shown in Section 3.3.12.



3.2.13 Social Media Social media are used for social interaction and feature highly accessible and scalable communication techniques. Web-based and mobile technologies are used to turn communication into interactive dialogue, which is an effective means of publicizing information. They are relatively inexpensive and accessible, enabling anyone to publish or access information, compared to industrial media, which generally require significant resources to publish information. For many users, especially the younger generation, online social networks are not only a way to keep in touch, but a way of life. Online social networks can be effectively used to:

• Create social communities that promote water reuse. • Integrate with existing network communities to publicize news related to water reuse. • Arrange online events through Facebook, Twitter, MySpace, LinkedIn, YouTube, etc.

3.2.14 Social Events The following are examples of social events that may be used:

• Organize seminars and forums on water reuse in various cities and arrange for them to be covered by media. The events should focus on alleviating the social and cultural beliefs that have slowed progress in embracing recycled water usage.

• Announce competitions to identify innovative uses of recycled water in TV and newspapers to stimulate more public involvement.

• Evaluate malls, mosques, and hotels for using recycled water and present awards at a public function. This will encourage more to “jump on the bandwagon.” Such promotions have been used successfully to promote water conservation in hotels.

• Identify key groups and individuals who are influential in shaping public opinion and invite them to small group meetings. These should represent a cross section of issues, locales, stakeholders, etc., and are different from focus group meetings.

• Organize a festival for a week during Saudi Water Day (coinciding with World Water Day- 22 March) where water reuse can be promoted using seminars, debates, etc.

3.2.15 “Road Show” Materials Educational materials could be created and tailored to reach audiences at these social events. These “road show” materials could include a film documentary and brochures, for example. These materials would visually display key messages about the need for sustainable water resources management and treatment capabilities and would offer “take-away” printed materials. Examples are presented below.

http://en.wikipedia.org/wiki/Social_interaction



Brochures



Television Documentary

3.2.16 In-School Educational Programs In-school education programs are an important component of a long-term education campaign. In-school programs not only raise the awareness of students so that they become informed adults, but students also become “change agents” in their homes and communities. In-school programs could include the following components:

• Develop PowerPoint presentations on treatment techniques, reuse needs and applications, advantages, etc., and forward to schools to present to students.

• Suggest modifications to the school curriculum to introduce topics on reuse and its importance.

• Encourage students to develop or participate in water reuse projects in their extracurricular activities.

• Arrange for experts to conduct seminars in schools to explain to students the processes involved in water treatment, wastewater treatment, and quality control.

• Encourage students to display scale models that use recycled water in annual exhibitions.

• Conduct educational tours of reuse Knowledge and Information Centers.

• Sponsor a competition among students to propose the best TV clip annually as part of Saudi Water Forum (SWF) events.

3.3 Gaps and Conclusions Water reuse has been identified as an essential component of the long-term integrated water resource management plan for KSA. However, there is currently insufficient wastewater collection and treatment, and limited distribution of reuse water. Additionally, there are varying levels of regulations and enforcement of existing wastewater collection, treatment, and disposal processes, as discussed in other chapters. Because of the widely varying wastewater treatment



and disposal methods and the apparent lack of effective regulation and enforcement, there is general confusion and a lack of understanding on the part of the public about the safety of reuse. A well-designed Public Education, Outreach, and Awareness Program is necessary to address these issues.

Recycled water has also been proven as a reliable means of preventing degradation of receiving waters and the environment as a whole, and could also reduce the investment required in expensive desalination plants. Water reuse projects have been successful not only in arid and semi-arid regions, but also in regions with temperate climates to protect sensitive areas, enhance recreational activities, support water-intensive economic sectors, and help populations cope with water crises during droughts. In KSA, recycled water is the only low-cost alternative resource for irrigation, which constitutes approximately 85 percent of the overall water demand. Clearly, government needs to give special emphasis to promoting agriculture with recycled water.

In addition, the successful implementation of the reuse program must take into account local cultural and religious traditions, values, and beliefs. Islamic Law requires pure water for certain purposes, including ablution, and defines how the water can be made pure. As noted above, the Council of Leading Islamic Scholars in KSA issued a fatwa in 1978 stating that reuse water, if treated sufficiently to ensure good health, is considered pure because the impurities are removed during the treatment process. However, the public has been slow to accept that reuse is a safe and appropriate water resource.

Research suggests that public support for reuse is largely dependent upon understanding of the water cycle, water treatment processes, and the terminology used to describe it. However, with re-branding, simple language and structured learning, the public can come to embrace reuse. A targeted survey is recommended to focus on re-branding recycled water including positive terms such as ‘Essential Water’, ‘Clear Water’ (proposed by MOWE) and Tahir.

A comprehensive Public Education, Outreach, and Awareness Program should be developed in conjunction with the investments in expanding reuse opportunities in KSA. The program will not only provide education on reuse, but also on the overall goals and importance of water and energy conservation and environmental benefits of reuse such as the reduction of greenhouse gas emissions through energy use reductions.

Such a program should include establishment of a Steering Committee, research, branding, and other techniques discussed above. Provision of demonstration projects, knowledge centers, and interactive web-based tools will be instrumental in building public understanding of complex processes by using easily understandable terminology and imagery. Lastly, such a program should also include mass media approaches and in-school education. Engagement of leading religious scholars throughout all aspects of the program will be essential in gaining support for reuse and acceptance of reclaimed water in religious practice. 3.4 References Global Water Intelligence. 2009. Water Market, Middle East 2010.

Hatem Al Motairi. Water quality standards and regulations in Saudi Arabia presented by Director of water quality standards, PME.

Hatem Aseer Al Motairi, Head Water Quality Section, MEPA, Jeddah, Saudi Arabia. 2001. Water Quality Regulations and Wastewater treatment and reuse in Saudi Arabia.

Lazaova, V. B. Levine, J. Sack, G. Cirelli, P. Jeffery, H. Muntau, M. Salgot, and F. Brissaud. 2001. Role of water reuse for enhancing integrated water management in Europe and Mediterranean Countries. Water Science and Technology Vol. 43 No. 10 pp 25–33. IWA Publishing.



Macpherson, Linda. Dr. Paul Slovic. 2011. Talking About Water: Vocabulary and Images that Support Informed Decisions about Water Recycling and Desalination, Research Report and User Guidance. Report WRF-07-03. Published by the WateReuse Research Foundation, Alexandria, Virginia, USA.

Maliva, Robert G., T. M. Missimer, F. P. Winslow. 2010. Aquifer Storage and Recovery of Treated Sewage Effluent in the Middle East.

Ministry of Water and Electricity and The World Bank Group. 2009. Presentation: National Water Strategy for the Kingdom of Saudi Arabia-An update.

Mohammed A. Al-Hajri . 2009. Wastewater Reuse Regulations in Saudi Arabia. Saudi Aramco Presentation. Presented 2-4 March 2009.

Negewo, Bekele Debele, PhD. 2011. Presentation―Water Outlook for the MENA Region Up to 2050: With Special Focus on Desalination and Renewable Energy by, Water Resources Specialist. World Bank in Consultative Workshop to Update the Kingdom’s Water Strategy, 8th June 2011 Ministry of Water and Electricity, Riyadh, Kingdom of Saudi Arabia.

PUB, Singapore Web site. www.pub.gov.sg. Accessed May-July 2011.

Ruetten, John. 2004. Best Practices for Developing Indirect Potable Reuse Projects: Phase I Report. WateReuse Association Report 01-004-01.

USAID. 2004. Wastewater Treatment Facilities for Small Communities: Community Screening and Selection Consultation Workshop. Amman, Jordan. 31 October 2004.

U.S. Environmental Protection Agency (USEPA). 2004. Guidelines for Water Reuse, Chapter 8, Water Reuse Outside the U.S.

chapter 4: business opportunities

STRATEGIC STUDY

Chapter 4: Business Opportunities 4.1 Introduction Expanding the current level of reuse in KSA in a financially rational way will support economic development at the local, regional, and national scales by leveraging the country’s scarce water resources and by providing a dependable and sustainable water supply to meet growing demand. The financial viability of reuse projects and the business opportunities that can be associated with them depend in part on understanding the relationship among the various water sources, first uses, and reuses of water either originally extracted from the sea and made usable with desalination or extracted from groundwater sources.

Desalination is relatively expensive and groundwater sources may only last another 15 to 25 years under current withdrawal rates without a significant increase in recharge (Kajenthira et al., 2011). Additionally, to the extent that treated wastewater is discharged to the sea or not otherwise directed to recharge, water is lost to the system that could be retained and recycled. Plans to change the current rate structures and tariff levels for water, wastewater treatment, and RQTSE will support a more sustainable water supply and wastewater treatment program and support expanded reuse while reducing subsidies that create disincentives for reuse.

This chapter establishes the economic and financial basis for reuse in several parts. First, the macro-level case for reuse is presented, driven by the limitations of groundwater and high costs associated with desalination. Projections for future RQTSE availability are then examined using information from MOWE’s 13 Draft Regional Planning Reports (ItalConsult, 2009-2010, see also Chapter 1). Specifically, those reports assigned allocations to five major reuse categories: agriculture, landscaping, industry, recreation, and aquifer recharge. This analysis helps identify absolute and relative opportunities across categories at the regional and local level. Two sets of case study examples are then presented and analyzed that show the costs and economic benefits of specific reuse projects, proposed or currently in place. The first set is drawn from the Draft MOWE Regional Planning Reports but compiled and analyzed collectively in a way not found in those reports. The second set consists of site- or company-specific case studies developed specifically for this study through literature and consultations with the involved parties.

Those presentations and analyses provide the foundation for further evaluating the business case for reuse through a set of five distinct scenarios that reflect different allocations of RQTSE to the five reuse categories. These scenarios were developed and analyzed using a publicly available Excel model, ProjectSelectTM, specially customized for this study so that reuse scenarios could be more easily defined and evaluated with the model. ProjectSelectTM was developed by CH2M HILL, in collaboration with Clean Water Services, a wastewater and stormwater utility in Oregon (USA) (Matichich, 2010). The customized version will be provided to KAUST and included with copies of the report at the conclusion of this study to support further development and evaluation of additional generalized reuse scenarios, as well as site-specific project proposals.

The featured scenarios are defined to be consistent with the types of situations that currently exist or can be fostered in KSA. Comparing and contrasting their performance on financial

CHAPTER 4: BUSINESS OPPORTUNITIES

4-2 STRATEGIC STUDY

and non-financial metrics shows how reuse can be financially viable and attractive for customers and providers. Together, the assessment of future projections, case studies, and the scenarios developed specifically for this chapter provide the basis for a set of findings and recommendations presented at the end of the chapter.

This chapter builds extensively on and is in some respects a continuation of the information presented in Chapter 1, in particular as relates to the future projections for reuse by sector, region, and locality drawn from the Draft MOWE Regional Planning Reports. The technology assumptions made for the reuse scenarios developed for this chapter reflect and are consistent with the information and assessment presented in Chapter 2. The formulation of the scenarios and the specification of the non-financial criteria developed to help evaluate them reflect the information and discussions provided in chapters related to public education and awareness (Chapter 3), regulatory considerations (Chapter 7), and aquifer recharge (Chapter 5).

4.2 The Macro-Case for Reuse: Energy and Sustainability KSA occupies 2.2 million square kilometers (km2), and is the largest country in the world with no lakes or rivers to sustain its population of 25.7 million. Despite possessing annual renewable water resources from groundwater of only 2.4 billion m3, Saudi Arabia’s water withdrawals exceeded 20 billion m3 in 2010, making it the third-largest per capita water user worldwide (Kajenthira et al., 2011). Over 80 percent of Saudi Arabia’s water supply is withdrawn from non-renewable groundwater aquifers, which are estimated to contain only a 15- to 25-year supply at present extraction rates. Water demands, exacerbated by rapid population growth and increased urbanization, are expected to double over the next two decades, with the municipal and industrial sectors increasingly reliant on saltwater (sea water and brackish groundwater) desalination (Kajenthira et al., 2011).

Desalination, particularly the large-scale thermal desalination commonly used in Saudi Arabia, is a capital- and energy-intensive means of producing freshwater. Thermal processes are generally suitable for large-scale facilities with a co-generation option. However, there is a critical need to develop alternative approaches to produce water for small and remote locations at affordable cost. Water reuse is one of the viable options where produced water can be used for agricultural and urban irrigation or in some cases high quality industrial uses (e.g., microchip manufacturing) or indirect/direct potable reuse as practiced in Singapore (see Chapter 3).

Regardless of the type of beneficial use, reuse can reduce drinking water consumption for various activities (i.e., agricultural and urban irrigation and industrial uses) and offset high costs associated with desalination as well as reduce demand on groundwater supplies. Table 4-1 presents energy requirements for tertiary treatment (which is the additional step required in KSA for production of reclaimed water for unrestricted reuse), reuse RO, brackish water RO, and commonly used seawater desalination technologies. In many reuse schemes, including urban and agricultural irrigation, the required tertiary treatment can be implemented by employing media filtration and chlorine disinfection. In some cases, high-TDS wastewater (i.e., greater than 2,500 mg/L) requires partial RO treatment to meet the all-purpose irrigation TDS objective of no higher than 2,500 mg/L. The energy cost of RO in reuse projects is much lower than that of seawater RO projects because much lower feed pressure is required to overcome osmotic pressure in reuse RO projects.

The reduction of water withdrawals from groundwater and desalination by increasing wastewater reuse is clearly promising if the energy requirements and the carbon footprint of desalination versus reuse are considered. Increased wastewater reuse has long been recognized as a potential intervention strategy in addressing water scarcity; however, the lack of national policies and/or strategies to support wastewater treatment and reuse has significantly restricted reuse in most Arab countries, including Saudi Arabia, until recent


STRATEGIC STUDY 4-3

years. With the vision of MOWE, NWC, and universities, an increase in sewerage networks to facilitate wastewater collection and treatment has been aggressively targeted in upcoming years.

The reduction of water withdrawals from groundwater and desalination by increasing wastewater reuse is clearly promising if the energy requirements and the carbon footprint of desalination versus reuse are considered. Increased wastewater reuse has long been recognized as a potential intervention strategy in addressing water scarcity; however, the lack of national policies and/or strategies to support wastewater treatment and reuse has significantly restricted reuse in most Arab countries, including Saudi Arabia, until recent years. With the vision of MOWE, NWC, and universities, an increase in sewerage networks to facilitate wastewater collection and treatment has been aggressively targeted in upcoming years.

Plans to increase the exceptionally low urban water tariff from 0.10 SR/m3 to as much as 5.25 SR/m3 by NWC will be a key factor in reducing overall water consumption and more adequately representing the costs of water provision and treatment. It also is expected that tariffs for desalinated water and natural gas will be increased to reflect production costs while the reuse of treated wastewater may be subsidized for a period to increase reuse demand. Increased tariffs for first use water will make water reuse a more attractive option while also making it a key component of a sustainable water management strategy and program.

4.3 Potential RQTSE Uses, Market Size, and Growth Trends The Draft MOWE Regional Planning Reports divide the list of potential RQTSE uses into five categories: agriculture, landscaping, industry, recreation, and aquifer recharge. More specific examples of reuse within these categories are also listed in Table 4-2, drawn from the Draft MOWE Regional Planning Reports, case studies, and other sources.

The potential market size for each of the main reuse categories can be assessed using the Draft MOWE Regional Planning Reports’ data, as seen in Figures 4-1 through 4-5. These present estimates for reuse at the country, regional, and city level. Observations about what the charts show are provided following Figure 4-5. Chapter 1 presents more detail about the regions and the cities and their current and future projected water supplies, wastewater flows, and reuse opportunities.

TABLE 4-1 Energy Requirements of Commonly Used Reuse and Seawater Desalination Technologies

Electrical Energy (kWh/m3)

Thermal Energy (kWh/m3)

Equivalent Thermal Energy

(kWh/m3)

Reuse Technologies Tertiary Treatment (gravity media filtration

coupled with chlorine disinfection)a 0.01-0.02 0 0.04-0.08

Reuse ROb 0.5-1.5 0 2-6 Desalination Technologies

Brackish Water ROa 1 0 4 Seawater Reverse Osmosis (SWRO)c 4 0 15

Multiple Effect Distillation (MED)c 1 70 74 Multi-Stage Flash (MSF)c 5 80 100

a Based on recent experience with similar projects. b Cote et al, 2005. c Sharqawy, 2011


4-4 STRATEGIC STUDY

TABLE 4-2 Reuse Applications by Primary and Sub-Category Primary Categories Sub-Categories/Examples

Agriculture • Tertiary treatment is required to meet unrestricted agricultural irrigation, which includes salad crops and vegetables eaten raw, and restricted, other crops; winter and summer cultivation.

• Crop examples include: cereal, vegetables, melons, watermelon, fruits, citrus, grapes, dates, fodder, alfalfa.

Landscaping • Secondary treated and disinfected water suitable for most landscaping in areas without direct human contact. Tertiary treatment is required for use in public parks or other areas where direct human contact is likely.

• Applications include: green areas in the cities, such as planting trees along roads, turf and grass areas, and public parks.

Industrial • Secondary treated and disinfected water in some cases (cooling towers, irrigating nurseries and plants surrounding industrial areas).

• Very high quality water for some uses (high pressure boiler feed); even higher quality may be needed for other uses.

Recreation • Not regulated in KSA yet. However, in most cases, tertiary treatment is required for unrestricted recreation.

• In Al Jouf Region: small lakes or parks • In Riyadh Region: development of Wadi Hanifa, maintenance of Al

Hayer Lakes Aquifer Recharge • Not regulated in KSA yet. The requirements vary depending upon

recharge type (direct recharge or sub-surface spreading, etc.). • Used to reduce the scale of drop in water table. • In Qaseem Region: allocated amounts flow through a wadi and mix

with stored water from stormwater for aquifer recharge.

Across the regions and cities, reuse by sector compares as follows; again, only cities with some industrial use are included in the above figures:

• Many of the regions and cities are projected to have substantial amounts of their total reuse delivered to the agricultural sector.

• In most regions and cities, landscaping is the next most prominent use after agriculture.

• Industrial use is significant in some regions and cities, and less so in others. While three regions show no industrial reuse projected at all, all the cities show at least some industrial reuse, but this is because cities with no industrial allocations are excluded from the chart.

• Only three regions show some recreational projections, all at 10 percent or less, and only two of the cities had recreational projections.

• Only one region has any aquifer recharge shown.

With respect to trends by reuse type, the Draft MOWE Regional Planning Reports’ data reflect different assumptions about the growth rate in reuse between 2010 and 2025, and between 2025 and 2035. In general, the Draft MOWE Regional Planning Reports assume the same or similar growth rates for each category for all cities in a region.


STRATEGIC STUDY 4-5

FIGURE 4-1 Reuse Projections, Country-Wide by Use Type

Note: This chart was generated from tabular data extracted from the Draft MOWE Regional Planning Reports

FIGURE 4-2 Proposed Reuse Amounts: by Type for Regions, 2025

Note: The height of the bar shows the total amount, and each type is represented by a different colored segment.This chart was generated from tabular data extracted from the Draft MOWE Regional Planning Reports.

0

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Narjan Qaseem Riyadh Tabouk

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4-6 STRATEGIC STUDY

FIGURE 4-3 Proposed Reuse Amounts: by Type for Regions as a Percent of Regional Total, 2025 Note: These are the same data as shown in Figure 4-2, but each region-type segment is shown as a percent of total for that region. This display allows for better comparison of the relative allocations of types across the regions. This chart was generated from tabular data extracted from the Draft MOWE Regional Planning Reports.

FIGURE 4-4 Proposed Reuse Amounts: by Type for Cities with Industrial Reuse, 2025 Note: The height of the bar shows the total amount, and each type is represented by a different colored segment. This chart was generated from tabular data extracted from the Draft MOWE Regional Planning Reports.

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STRATEGIC STUDY 4-7

FIGURE 4-5 Proposed Reuse Amounts: By Type for Cities with Industrial Reuse as Percent of City Group Total, 2025

Note: These are the same data as shown in Figure 4-4, but each city-type segment is shown as a percent of total for that city. This display allows for better comparison of the relative allocations of types across the cities. This chart was generated from tabular data extracted from the Draft MOWE Regional Planning Reports.

For this reason, Table 4-3 provides a tabular comparison of the growth rates across regions only for the two periods in the Draft MOWE Regional Planning Reports’ data by reuse category for four of the five categories. Aquifer recharge is projected for only one region, Qaseem: growth is projected to be about 2.2 percent annually from 2010 to 2035.

TABLE 4-3 Reuse Sector Growth Rates and Associated Statistics

Agriculture Landscaping Industry Recreation

10-25 25-35 10-25 25-35 10-25 25-35 10-25 25-35

Average 5.6% 2.1% 5.7% 2.5% 5.9% 2.6% 7.1% 5.0%

Median 4.5% 2.2% 4.4% 2.2% 4.2% 2.2% 7.1% 3.3%

Minimum 1.6% 0.4% 2.4% 0.4% 2.3% 2.0% 5.4% 2.2%

Maximum 16.8% 3.3% 15.9% 7.2% 13.2% 6.5% 8.9% 9.4%

Standard Deviation

4.4% 0.8% 3.9% 1.6% 4.0% 1.4% 2.5% 3.9%

Figures 4-6 through 4-9 graphically present the reuse sector growth rates calculated from the Draft MOWE Regional Planning Reports’ data (imputed growth rates). Together, the tabular and graphic data show the following about the relative growth rates within and across the four categories at the city level:

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4-8 STRATEGIC STUDY

• Consistent with the Draft MOWE Regional Planning Reports’ regional and city data presented in Chapter 1, growth rates for 2010 to 2025 are higher, sometimes many times higher, than for 2025 to 2035.

• Most growth rates for all region-use combinations for 2025 to 2035 are in the 2 percent to 3 percent range.

• Average and median growth rates are similar for agriculture, landscaping, and industry. Recreation rates are slightly higher, but notably only represent three regions.

• Agriculture has a lower minimum and a higher maximum across regions than the other uses for 2010-2025. Landscaping and industry rates are comparable.

• Agriculture, landscaping, and industry show similar variance in rates for 2010-2025 across regions, as indicated by the standard deviations.

FIGURE 4-6 Proposed Reuse Amounts for Regions: Agriculture, Imputed Annual Growth Rate for 2010-2025 and 2025-2035

Note: This chart was generated from tabular data extracted from the Draft MOWE Regional Planning Reports.

4.4 Reuse Case Studies: Current Practices and Future Proposals

This section presents two sets of case study examples that show the costs and economic benefits of specific reuse projects, proposed or currently in place. As noted above, the first set is drawn from the Draft MOWE Regional Planning Reports, but compiled and analyzed collectively in a way not found in those reports. The second set consists of site- or company-specific case studies developed specifically for this study from the literature and consultations with the involved parties.

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STRATEGIC STUDY 4-9

FIGURE 4-7 Proposed Reuse Amounts for Regions: Landscaping, Imputed Annual Growth Rate for 2010-2025 and 2025-2035


FIGURE 4-8 Proposed Reuse Amounts for Regions: Industry, Imputed Annual Growth Rate for 2010-2025 and 2025-2035


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FIGURE 4-9 Proposed Reuse Amounts for Regions: Recreation, Imputed Annual Growth Rate for 2010-2025 and 2025-2035


4.4.1 Case Studies Drawn from Draft MOWE Regional Planning Reports The Draft MOWE Regional Planning Reports include 64 case studies addressing the costs and benefits of proposed reuse projects in five regions: Riyadh (54), Eastern Province (4), Jizan (1), Al Madinah (2), and Al Qaseem (3). The reports also include 22 case studies with primarily the cost estimates for proposed projects; 12 of these are also among the cost-benefit examples. Table 4-4 presents summary statistics for the 68 projects that had sufficient data for the entire group, and for each major reuse category. These case studies represent a range of reuse projects similar to those described in Table 4-2.

Table 4-4 presents the average, median, minimum, maximum, and standard deviation values for the project attributes shown for all projects. The summary statistics for all 68 projects reflect the wide range of system scales and costs. Table 4-5 provides some discussion comparing the agriculture, landscaping, and industry sub-groups to the statistics for the entire data set.

The cost-benefit ratio is the quotient of the total cost divided by the total revenues: as such, a value of 1 indicates the project exactly breaks even; a value less than 1 indicates the project is profitable (revenues exceed costs); and a value greater than 1 indicates the project loses money (costs exceed revenues). Because it is a ratio, it can be used to directly compare projects on a relative basis, regardless of size. Figure 4-10 shows the ratios for all 64 examples from the Draft MOWE Regional Planning Reports that included specific cost-benefit calculations, while Figure 4-11 shows the ratios for the 55 projects with ratios less than 0.6 to better delineate the relative positions of the markers. The 64 projects are distributed as follows: 32 agriculture; 26 landscaping; 5 industry; and 1 recreation.

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TABLE 4-4 Summary Data from 68 Reuse Case Studies Detailed in the Draft MOWE Regional Planning Reports

Note: This table was compiled from the individual case studies presented in the MOWE reports.

Proposed Amount

(1000 m3/d)

Pipeline Length

(km)

Pipeline Diameter

(mm)

Pumping Station

(kW)

Storage Volume

(Mm3)

Pipeline Cost

(M SR)

Pumping Station

Cost (M SR)

Storage Cost

(M SR)

Delivery Subtotal

Capital Cost (M SR)

Delivery O&M Cost

(M SR)

Wastewater Treatment

Capital Costs

(M SR)


O&M Costs (M SR)

Total Cost (M SR)

Cost per Year

(25 yrs, M SR)

Assumed Price

(SR)/m3) Revenue (M SR)/yr

Cost/Benefit

All Data (n=68)Average 27 13 765 247 4 28 3 2 32 3 38 7 40 2 1.46 14 0.4Median 5 7 800 100 3 9 2 0 11 1 0 5 13 1 1.00 2 0.3

Min 1 1 0 0 0 1 0 0 3 0 0 0 3 0 0.50 0 0.0Max 400 176 1800 4000 10 585 27 10 605 48 180 25 653 26 3.00 438 1.4

StDev 58 24 238 557 4 75 4 3 78 6 76 8 96 4 0.67 58 0.3Agriculture (n=33)

Average 28 18 691 300 4 44 3 2 47 4 49 8 63 3 0.87 5 0.5Median 7 8 800 100 5 9 2 0 11 1 0 5 15 1 1.00 2 0.3

Min 1 1 0 0 0 1 0 0 3 0 0 0 3 0 0.50 0 0.1Max 151 176 1000 4000 10 585 10 10 605 48 180 25 653 26 1.00 28 1.4

StDev 40 33 247 710 4 105 2 4 109 9 84 9 132 5 0.22 7 0.4Landscaping (n=27)

Average 10 7 807 168 3 9 3 2 11 1 0 9 13 1 1.91 5 0.3Median 3 6 800 100 3 6 2 2 9 1 0 9 10 0 2.00 2 0.2

Min 1 1 600 38 3 1 1 0 3 0 0 9 3 0 0.70 1 0.0Max 135 22 1200 1000 3 29 13 3 33 3 0 9 45 2 2.00 49 0.9

StDev 27 4 87 201 7 2 2 8 1 10 0 0.32 10 0.2Recreation (n=1)

135 4 1200 0 0 8 0 0 8 0.8 0 0 9 0.4 2.00 99 0.1Industry (n=7)

Average 72 13 886 330 1 34 5 1 39 3 0 5 43 2 2.20 93 0.3Median 20 14 800 48 1 15 1 0 17 2 0 5 18 1 3.00 10 0.2

Min 2 2 500 0 0 2 0 0 4 0 0 3 5 0 1.00 2 0.1Max 400 25 1800 2000 2 81 27 2 92 9 0 6 101 4 3.00 438 0.7

StDev 145 10 434 737 1 33 10 1 38 4 2 42 2 1.10 193 0.3



TABLE 4-5 Observations about Draft MOWE Regional Planning Reports’ Case Study Statistics by Sub-Group Relative to the Entire Set Agriculture Landscaping Industry

Delivery System Specifications

Scale comparable for all 68

Four projects with storage: two with 10 M m3 and two with 5 M m3

Proposed amounts less and pipeline length shorter

Only one project with storage (3M m3)

Proposed flow amounts most among groups but pipeline length comparable

Average pumping kW higher, but median lower

Delivery System Costs

Slightly higher than all 68, as pipeline lengths longer

Lowest costs among groups

Less than for agricultural set but higher than for landscaping


Identical to all 68—only data in groups

None included in examples

None included in examples

Total Costs Higher than all groups and greater variance

Lowest among groups and small variance

Middle among groups and moderate variance

Assumed Price and Revenues

Lowest assumed pricing (1 SR m3) and low revenues

Middle pricing (2 SR m3) but low revenues due to relative quantity

Highest pricing (2-3 SR m3) and highest revenues resulting from high pricing and high quantities

Cost-Benefit Ratio Comparable to all groups Lower than agricultural, similar to industry

Lower than agricultural, similar to landscaping

Note: Recreation is excluded from this summary since there was only one example.

FIGURE 4-10 Cost-Benefit Ratios for 64 Project Examples from the Draft MOWE Regional Planning Reports Note: This plot shows ratios for all 64 projects as compiled from the individual case studies.

FIGURE 4-11 Cost-Benefit Ratios for 55 Project Examples from the Draft MOWE Regional Planning Reports

Note: This plot excludes examples with values > 0.6 to better display the data as compiled from the individual case studies

Together, Figures 4-10 and 4-11 show the following about the cost-benefit ratios for the plotted projects:

• The Draft MOWE Regional Planning Reports’ case studies illustrate that reuse can be economically viable. Most of the ratios are below 0.6, much better than the break-even value of 1.0. Of those projects with cost-benefit ratios higher than 0.6, there are six

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5

Cost-Benefit Ratio

Riyadh-Agriculture Riyadh-Industrial/Cooling Riyadh-Landscaping Riyadh-Recreation Eastern Province-Agriculture

Jizan-Agriculture Madinah-Industry Madinah-Landscaping Al Qaseem-Agriculture Al Qaseem-Industry

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60

Cost-Benefit Ratio

Riyadh-Agriculture Riyadh-Industrial/Cooling Riyadh-Landscaping Riyadh-Recreation Eastern Province-Agriculture

Jizan-Agriculture Madinah-Industry Madinah-Landscaping Al Qaseem-Agriculture Al Qaseem-Industry



agricultural projects, two landscaping projects, and one industrial project. Among this group, the ratio ranges from about 0.7 to 1.4. Among these examples, only three projects do not at least break even, and they are all agricultural examples where the rate is 0.5 or 1.0 SR/m3.

• The more detailed view shown in Figure 4-11 also shows that the ratio range for the agricultural projects (orange and yellow markers) is generally higher than for landscaping (green markers), although there is some overlap of the ranges. The industry project markers (blue) are more visible in this chart, and are seen to be in the low end of the range, overlapping with many landscaping projects and fewer agricultural projects.

• With respect to the specific user categories:

− Most of the agricultural projects appear in the 0.3 to 0.6 range, the six higher projects ones notwithstanding.

− Most of the landscaping projects appear in the 0.1 to 0.5 range, and some are even lower.

− The five industry projects have ratios of 0.01, 0.07, 0.08, 0.30, and 0.70.

− The single recreation example has a ratio of essentially zero.

4.4.2 Other Case Studies The current water tariff for most users in KSA (0.10 SR m3/day) is very low, which makes many reuse schemes other than industrial uses (for which tariffs are higher) currently infeasible. On the other hand, reasonable water tariffs make water conservation, treatment, and reuse an attractive option for industries. Reuse case studies in this section are based on the studies performed by the subject industries or independent parties to evaluate the feasibility of implementing reuse in industrial facilities. Payback periods were also provided in most cases to demonstrate whether the investment required for recovering and treating wastewater for reuse can offset water purchases within a reasonable period.

In addition to water reuse, resource recovery, which is an integral component of sustainability, has gained significant attention in the last decade. For example, converting organic material to biogas via anaerobic digestion to produce energy/heat has been practiced for many years. The biogas to energy benefits have already been proven across the globe. More recently, technologies are being or have been developed to recover micro-nutrients (i.e., nitrogen and phosphorus) from wastewater. The recovered material is a valuable asset for agricultural uses. The case study examples herein also include resource recovery studies from the USA and from KSA.

Saudi Arabia Basic Industries Corporation (SABIC) Water Reuse Study SABIC is one of the world’s 10 largest petrochemicals manufacturers and among the world’s market leaders in the production of polyethylene, polypropylene, glycols, methanol, methyl tert butyl ether (MTBE), and fertilizers and polyolefins. SABIC industries consume large quantities of potable water for their processes while generating a significant quantity of wastewater. The water data for a SABIC facility located in Jubail show consumption of 96,000 m3/d of potable water and generation of approximately 45,000 m3/day of wastewater (Al-Hazmi and Jaffar, 2006). The wastewater is pretreated and conveyed to a central wastewater treatment facility for further treatment to meet stringent discharge requirements. A portion of the treated wastewater is currently used for landscape irrigation.

SABIC has implemented numerous programs to conserve water in its facilities. One key initiative was the feasibility study to evaluate the potential for recycling the wastewater being generated from SABIC industries. Another notable initiative was the establishment of a water conservation program well supported by a reward and recognition program. As part of



the water recycling program, SABIC first characterized wastewater quality in all industrial facilities. Second, a detailed feasibility study was conducted by a consultant to evaluate treatment requirements, treatment technologies, and associated costs for treating and reusing the wastewater. The feasibility study concluded that reuse is economically a feasible option in some locations.

SABIC also conducted a pilot study and Basic Engineering Evaluation on one of the industrial facilities for water reuse to reduce the freshwater intake and costs for potable water. The industrial facility included in the pilot program generated approximately 10,100 m3/day of wastewater from plastics, olefins, and utilities operations. The treated wastewater from the industry has been meeting the discharge standards on a regular basis. Due to wastewater quality and treatment requirement differences, PVC- and olefins-containing wastewater streams were collected and treated separately. In addition, SABIC was considering recovering PVC, which has a market value, from the wastewater. The wastewater quality and treated water quality goals are presented in Tables 4-6 and 4-7 for PVC-(Phase I) and olefins-containing wastewater (Phase II), respectively.

TABLE 4-6 Phase I (Wastewater Quality and Treated Water Quality Objectives)

Unit Design Value Maximum Value

Wastewater Flow m3/day 5,760

TOC mg/L 113 165

TSS mg/L 326 502

TDS mg/L 105 130

Ammonia-Nitrogen (NH4-N) mg/L 7

Phosphate (PO4-P) mg/L 0.1-0.5

Temperature °C 45

pH Standard unit 10.2 12.2

Treated Wastewater Quality Objectives

TOC mg/L <3

TSS mg/L <1

TDS mg/L <125 <150

The wastewater treatment processes used to meet Phase I water quality objectives for reuse included:

• Neutralization, primary clarification, and flow equalization for primary treatment • Linpor aeration tank and secondary clarification for biological or secondary treatment • Dual media filtration and chlorine based disinfection for tertiary treatment • Sludge stabilization, thickening, and dewatering for biosolids/sludge treatment

The wastewater treatment processes used to meet Phase II water quality objectives for reuse included:

• Pre-treatment in existing facilities • Dissolved air flotation and flow equalization for primary treatment • Linpor aeration tank and secondary clarification for biological or secondary treatment • Dual media filtration and chlorine based disinfection for tertiary treatment • Activated carbon and RO for advanced treatment (partial treatment only) • Sludge stabilization, thickening, and dewatering for biosolids/sludge treatment



TABLE 4-7 Phase II (Wastewater Quality and Treated Water Quality Objectives)

Unit Design Value Maximum Value

Wastewater Flow m3/day 5,470

TOC mg/L 101 272

TSS mg/L 60 120

TDS mg/L 300 500

NH4-N mg/L 28

PO4-P mg/L 0.4

Oil and Grease mg/L 100 300

Temperature oC 65

pH Standard unit 10.2 12.2

Treated Wastewater Quality Objectives

TOC mg/L <1

TSS mg/L <0.1

TDS mg/L <50

With the required treatment processes, SABIC projected 38M SR and 33M SR in capital investments required to treat and reuse the wastewater in Phases I and II, respectively. The economic evaluations for each phase, including payback periods, are summarized in Table 4-8. The short payback periods for each alternative strongly suggest reuse is economically feasible. The need for advanced treatment in Phase II increased the capital and O&M costs for unit wastewater treated, thereby resulting in a longer payback period compared to Phase I.

TABLE 4-8 Summary of Economic Evaluation Results: SABIC Water Reuse Study

Phase I Phase II

Total Annual Reuse Flow, m3/year 2,150,000 1,415,000

Water Purchase Cost SR/m3 6 6

Annual Water Purchase Cost Offset, SR/year 12,900,000 8,490,000

Unit Sell Price for Low Grade PVC, SR/ton 187.5 Not Applicable

Annual Revenue for Selling Low Grade PVC, SR/year 134,000 Not Applicable

Total Cost Offset/Revenue 13,034,000 8,490,000

Capital Investment, SR 38,000,000 33,000,000

Annual O&M Cost, SR/year 2,816,000 2,349,000

Payback Period, years 3.7 5.4

Jeddah Industrial City Textile Processing Industry Tamkeen Sustainability Advisors evaluated an industrial reuse case study in a textile processing plant located in Jeddah industrial city. Coloring carpets through dyeing and printing is the main activity of the company and its 450 employees. Typical of this sector, the



process uses large quantities of water (purchasing approximately 1,400 m3/day of potable water). Recognizing the financial and environmental potential linked to saving water, the company has evaluated treatment and reuse options within the industry (Wafeer, 2011).

All effluents from printing operations and from the RO unit are currently discharged into the sewage system as wastewater. The company has installed a storage tank to capture the discharges. Tamkeen Sustainability Advisors proposed that the collected effluents be treated via coagulation and flocculation followed by rapid sand filtration. The physical treatment process provided was found to be adequate for recycling the treated flow to the process for reuse. In addition, the industry is considering increasing the level of treatment applied to its effluents to treat and reuse more water. The future treatment plants will include:

• A biological treatment unit (not specified) • Dissolved air floatation (two tanks) • Media filtration • RO (partial treatment)

With the chemical treatment system (initial phase), the company will be able to reduce its water consumption by 800 m3/day. When the new treatment facilities (future phase) are commissioned, the industry is expected to save approximately 1,200 m3/day of water.

The economic evaluations for each phase, including payback periods, are summarized in Table 4-9.

In each case, reuse is a highly feasible option for the industry for reducing potable water consumption and offsetting potable water purchases within a very reasonable payback period. The company’s reduced need for desalination will also help lower its carbon footprint.

TABLE 4-9 Summary of Economic Evaluation Results: Jeddah Industrial City Textile Processing Industry

Initial Phase

Physical Chemical Treatment Only

Future Phase (includes Physical/Chemical and Biological and Advanced Treatment Facilities)

Total Annual Reuse Flow, m3/year 292,000 438,000

Water Purchase Cost SR/m3 6 6



Annual O&M Cost, SR/year 120,000a 700,000b

Payback Period, years 1.2 3.3

aProjected O&M Costs are based on 25 mg/L ferric and 1 mg/L polymer addition and 5 horsepower (HP) total load. bProjected O&M Costs are based on 25 mg/L ferric and 1 mg/L polymer addition and 5 HP total load for the initial phase and an additional SR 580,000/year for biological and advanced treatment facilities based on CH2M HILL experience on similar size projects.

Middle East Paper Company in Jeddah Middle East Paper Company (MEPCO), located in Jeddah, shows leadership in reducing water consumption and waste generation and using recycled paper for manufacturing while protecting the environment and offering economic value. Paper manufacturing requires high quantities water. Considering the lack of sufficient groundwater and surface water resources in Jeddah, MEPCO has developed innovative approaches to reduce water consumption



without sacrificing productivity. Jeddah lacks sufficient surface or underground water sources for MEPCO’s water-intensive operations (Wafeer, 2011).

First, MEPCO made the modifications necessary to use recycled water in its manufacturing process. Second, MEPCO has significantly improved its water efficiency, reducing its water consumption from 20 m3/ton paper produced to 8 m3/ton paper produced. The future goal of MEPCO is to further reduce its water consumption to 4 m3/ton paper produced.

MEPCO’s Jeddah facility had a production capacity of 100 000 ton/year in 2002 and it used treated wastewater from the Khumrah WWTP in Jeddah City, which is located close to the paper mill. The received wastewater was further treated by coagulation, flocculation, and chemical precipitation followed by RO before being used in the manufacturing process. In 2002, MEPCO used approximately 20 m3 of water per ton paper produced. In 2006, MEPCO extended its production capacity to 300,000 ton/year, which required three times more water for manufacturing. MEPCO evaluated inefficiencies regarding water consumption and assessed all waste streams that could be treated and recycled back into the process. The company installed drum screens, two dissolved air floatation units, and gravity filters, which reduced its water consumption to 8 m3/ton paper produced. This system also allowed the recovery of fibers. MEPCO’s innovative approach is depicted in Figure 4-12.

FIGURE 4-12 MEPCO’s Approach for Wastewater Treatment and Recycling in Jeddah City Facility

Note: Adapted from Wafeer, 2011 MEPCO is planning to install a biological treatment unit to further reduce the organic loading in the effluents and thus increase water recycling. Once the proposed upgrade is completed, MEPCO will be able to reduce its water consumption to 4 m3/ton of product.

With the additional treatment and recovery, MEPCO reduced its water consumption by 4,200,000 m3/year. Once the biological treatment unit is commissioned, MEPCO will save an additional 1,200,000 m3/year of water with a total water savings of 5,300,000 m3/year. MEPCO’s investments and estimated payback periods are summarized in Table 4-10.

Unlike the two previous case studies, much lower costs for water purchase have been used for forecasting savings and payback periods. If the current water purchase rate of SR 6/m3 had been used, the payback periods would be much less than 1 year for each phase of the project.

ARAMCO Riyadh Refinery Saudi ARAMCO has plans to increase production of its oil products and petrochemical products. The oil refining and petrochemical industries require vast quantities of water for cooling and other purposes. While water demand for industrial and residential users increases, the limited water resources will not be sufficient to supply water to industries, posing a serious problem (JETRO, 2009).



TABLE 4-10 Summary of Capital Investment and Payback Period for Water Recycling at MEPCO Paper Facility in Jeddah City

Initial Phase Drum Screens, Dissolved Air Floatation and Gravity Filters

Additional Biological Treatment Facility

Total Annual Reuse Flow, m3/year 4,200,000 5,300,000

Water Purchase Cost SR/m3 0.363a 0.407a



Annual O&M Cost, SR/year 770,000b 1,455,000b

Payback Period, years 2.0 16.1 a Back-calculated using actual savings of approximately SR 1,525,000 and 2,125,000 for the initial and future phases of the project, respectively. b Back-calculated using estimated payback periods of approximately 2 and 16 years for the initial and future phases of the project, respectively.

The Riyadh Refinery treats crude oil of 122,000 barrels per day (b/d), and the main products include liquefied petroleum gas (LPG) , gasoline, kerosene, diesel oil, fuel oil, and asphalt. The supply of industrial water primarily depends on the desalination of seawater, which is expensive (6 SR/m3) and consumes much energy. In late 2008, a feasibility survey on wastewater reuse was conducted in ARAMCO’s Riyadh Refinery. The purpose was to identify the condition of the existing water and wastewater treatment facilities and to explore the possibility of wastewater reuse in the plant; this action would document environmental and social considerations and relevant laws and regulations on implementing wastewater reclamation and reuse in KSA (JETRO, 2009).

The survey identified the following areas where reuse can be implemented:

• Boiler blowdown • Cooling tower blowdown • Oily wastewater from the oil/water separator • Sanitary wastewater

The survey results indicated that if reuse were implemented in all four areas, the industrial water demand could be reduced by 60 percent.

Because the Riyadh Refinery is a special case where both water and wastewater service are free of charge, the survey findings were used as a benchmark for developing conceptual studies. In one example, ARAMCO assumed a refinery capacity of 300,000 barrels (bbl) to determine if reuse is a feasible option. The projected capital investment and projected payback period are presented in Table 4-11.

Table 4-11 shows that the short payback period makes reuse an economically feasible option. Purifying wastewater using RO can be achieved with a much lower carbon footprint than seawater desalination using RO and thermal processes.

TABLE 4-11 Summary of Capital Investment and Payback Period for ARAMCO Refinery Reuse (Refinery Capacity: 300,000 bbl) Parameter Value

Treatment Plant Capacity, m3/day 12,000

Water Purchase Cost SR/m3 6

Annual Water Purchase Cost Offset, SR/year 23,652,000a

Capital Investment, SR 112,500,000

Annual O&M Cost, SR/year 2,200,000b

Payback Period, years 5.2 a Based on 90% on-line time for the advanced water treatment facility. b Based on CH2MHILL’s projections on similar size projects.



Nutrients Recovery in Durham Advanced Wastewater Treatment Facility, Oregon, USA Clean Water Services is a wastewater and stormwater public utility committed to protecting water resources in Oregon’s Tualatin River watershed. Its Durham Advanced Wastewater Treatment Facility (AWTF) in Tigard (suburban Portland) provides treatment for the Cities of Beaverton, Tigard, Sherwood, Tualatin, Durham, King City, and portions of Clackamas and Multnomah Counties, with a combined flow of over 20 mgd. The facility provides tertiary treatment, removing ammonia and nitrogen compounds biologically, along with combined biological and chemical phosphorus removal. Final effluent is further filtered with granular media (sand) filters for solids removal. Sludge is thickened, anaerobically digested, dewatered, and transported to the central part of Oregon for application on arid farmland (Ostara, 2011).

This reuse application of sludge is beneficial as phosphorus, an essential nutrient, will continue to be pressured by restricted supplies and burgeoning worldwide demand whether “peak phosphorus” occurs in 50 years or in 250 years. Wastewater streams from municipal and industrial treatment facilities are rich in phosphorus and ammonia, which are valuable nutrients to recover. If not recovered, discharging nutrient-containing wastewater effluents depletes oxygen in the receiving water, which could pose an environmental problem while at the same time losing valuable nutrients.

Recently, a few technologies have been developed to recover nutrients in wastewater. One of these, Ostara’s PEARL™ Nutrient Recovery Process, harvests up to 90 percent of phosphorus and 20 percent of nitrogen from treated wastewater and transforms them into a high grade, slow-release fertilizer called Crystal Green®. The PEARL™ Process prevents potentially polluting nutrients from finding their way into sensitive watersheds by extracting them for further processing. This eliminates phosphorus build-up in pipes, saving substantial money in maintenance costs. In addition, it produces a fertilizer that provides a revenue stream to further offset capital costs (Ostara, 2011).

To meet the strict discharge criteria on the Tualatin River, Clean Water Services’ Durham facility must seasonally treat phosphorus to a limit of 0.1 mg/L. As is common with biological phosphorus removal facilities, phosphorus and other nutrients from the sludge handling processes are recycled within the plant and increase the effective nutrient load on the main treatment process. Additionally, phosphorus, ammonia, and magnesium become highly concentrated in the sludge handling process and cause the formation of struvite (magnesium ammonium phosphate). This struvite formation coats pipes, valves, and other equipment, which reduces flow capacities and increases maintenance requirements.

To treat these nutrients and prevent struvite formation, Clean Water Services utilized chemical dosing (ferric chloride) and installed special Kynar® –lined pipes. These traditional solutions are expensive, so in order to operate more efficiently Clean Water Services initiated a study of Ostara’s PEARL™ Process with the following objectives:

• Reduce sidestream nutrient loads • Reduce potential for struvite scaling • Enhance beneficial reuse of AWTF nutrients • Meet 0.1-mg/L phosphorus effluent limit cost-effectively

Clean Water Services successfully completed a pilot plant demonstration of the PEARL™ process in the summer of 2007, and then contracted to procure a full-scale facility in October 2008, with operation beginning in the spring of 2009. Ostara’s scope of work encompassed all services and materials required to deliver a fully functional process capable of achieving the nutrient removal treatment objectives and producing a finished fertilizer product ready for shipment to customers. The treatment processes included:



• Three PEARL™ 500 Reactors • Chemical storage and dosing • Full process automation • All pumps, motors, valves, and process piping • Fertilizer product processing • Operator training and ongoing technical support • Modification of a decommissioned influent pumping station to house the facility

The installed PEARL reactors and other equipment are shown in Figure 4-13.

The capital and O&M cost details were not available for this ongoing effort. However, Ostara Nutrient Recovery Technologies indicated that the revenue generated from fertilizer purchase is enough to offset the investment cost in 5 years.

FIGURE 4-13 PEARL 500 Reactors in Durham AWTF (Courtesy of Ostara Nutrient Recovery Technologies)

Al Kharj Road STP – Riyadh Area This section describes the current standards and practices of wastewater sludge (biosolids) management in KSA, then presents a specific example of changes in biosolids management at one of KSA’s largest Sewage Treatment Plants (STPs), and concludes with a summary of how KSA plans to transition from current practices dominated by landfill disposal, to future practices that will focus more on the recovery of energy and nutrients from biosolids.

Current Biosolids Management Standards and Practices MOWE has developed draft regulations that set standards for land application of biosolids. This draft has been developed in collaboration with the MOA General Directorate for Irrigation and the Ministry of Municipal and Rural Affairs (MOMRA). The Ministry of Health (MOH) has also contributed indirectly through consultation on this standard. At the present time, the standards have been officially approved by both MOA and MOMRA, and are being reviewed for approval by MOWE (MOA, 2001).

The Presidency of Meteorology and Environmental Protection (PME) is entrusted with the control of pollution and the protection of the Environment. The environmental Standards include among other things the reuse of sludge in the Environment (PME, 2001).

The two above-mentioned documents represent the current status of regulatory standards addressing biosolids in the Kingdom at this time. The prevailing current practice for biosolids management is dewatering of unstabilized sludge at the various STP’s followed by hauling to landfills for disposal. There are a few cases of stabilizing sludge by digestion or composting



and applying to MOA lands, but landfilling of sludge predominates as the prevailing practice (NWC, 2011).

Al Kharj Road STP Case Study The Al Kharj Road STP serves the southeast and northeast portions of the greater Riyadh metropolitan area. The STP currently consists of two parallel process trains with treatment capacities of 100,000 m3/day each, known as Phase I and Phase II, respectively.

The treatment process consists of (in order of process flow): coarse screens, influent pumps, fine screens, grit and grease removal tanks, oxidation ditches operated to nitrify and denitrify, final clarifiers, and disinfection. The treated effluent is pumped to an offsite storage lagoon and used in agriculture. Waste activated sludge is removed from the final clarifiers and pumped to belt filter presses, which dewater the sludge to 20 percent to 24 percent dry solids concentration. The dewatered cake is discharged via inclined screw conveyor to roll-off containers, and is currently trucked offsite to landfill disposal.

With wastewater flows to the Al Kharj Road STP increasing rapidly, NWC has initiated the design and construction of a third phase of the STP. The capacity of Phase III will be 200,000 m3/day, which will double the size of the expanded STP to 400,000 m3/day.

The NWC is now negotiating with the design-build contractor that submitted the highest-scoring proposal (i.e., best combination of quality and price). The proposed, alternative process train that includes anaerobic digestion and biogas utilization has the capability of saving NWC from 5 million to 9 million SAR annually, as compared to the base process train. The estimated simple payback period for the additional equipment needed by the process alternative is a very attractive 5 to 8 years, during which the capital investment would be completely recouped and net savings would accrue in all subsequent years through the facility’s estimated 20- to 25-year service life (CH2M HILL, 2011).

Benefits of Biosolids Stabilization and Beneficial Use at Al Kharj Road and Other STPs If NWC accepts the alternative proposal to build anaerobic digesters that will stabilize sludge to produce biosolids as well as biogas at the Al Kharj Road STP, the following economic and environmental benefits will accrue.

• Digested biosolids will meet the Kingdom’s standards for reuse of biosolids in agriculture, as stipulated by the PME’s regulations for agricultural land application.

• The biosolids digestion process itself provides the following benefits:

− It destroys a high percentage of volatile solids, which reduces its total mass as well as odors and the potential to attract vectors.

− The volatile solids that are “destroyed” are actually converted to biogas that is comprised 60 percent of methane, which gives it a high fuel value for energy and heat production, since methane is the active ingredient in natural gas.

− It substantially reduces the levels of pathogens in biosolids by increasing the temperatures and providing long detention times that allow for pathogen kill.

• Digested and stabilized biosolids have been shown to provide many benefits in agricultural production, including:

− Biosolids add the essential, major nutrients (nitrogen, phosphorus, and potassium) in addition to a large number of essential micronutrients that are needed for healthy plant growth.

− Biosolids contain a high percentage of organic carbon that is required for maintaining fertile soils that are needed for healthy plant root systems.



− Biosolids contain a high percentage of water, needed especially in the desert climate.

As noted above, the Kingdom currently landfills a large proportion of sludge from wastewater treatment, but implementing new treatment processes such as digestion will enable the Kingdom to transition from a paradigm of sludge disposal to one of reuse and resource recovery of biosolids. This transition and its many benefits will be similar to the transition the Kingdom is undergoing for the reuse of treated effluent (NWC, 2011; and CH2M HILL, 2011).

4.5 Formulation of Scenarios for Analysis The data presentations and analyses featured in Sections 4.1 through 4.4 provide the foundation for further evaluating the business case for reuse through a set of five distinct scenarios that reflect different allocations of RQTSE to the five reuse categories. They are defined to be consistent with the types of situations that currently exist or can be fostered in KSA. Comparing and contrasting their performance on financial and non-financial metrics shows how reuse can be financially viable and attractive for customers and providers.

4.5.1 Introduction and Basis for Defining Scenarios The business case for reuse depends on a variety of factors, including treatment and delivery costs, rate structures (absolute SR/m3d as well as relative cost across uses), and broader national and utility objectives. Additionally, the business case must not only be framed in the context of current reuse amounts, perspectives about different types of reuse, and rate issues, but also considering goals and practical capabilities for future expansions of absolute volume, public education about benefits and safety, relative growth potential across reuse types, improvements in willingness to pay for RQTSE, and ability to implement a financially viable rate structure.

The five scenarios featured in this study were developed based on projected uses specifically described in Section 4.3, and the policy goals and capital plans more generally described in Chapter 1. The sector-components of the scenarios include reuse in one or all of the following major categories, consistent with the Draft MOWE Regional Planning Reports’ projection categories: agriculture; landscaping; industry; recreation; and aquifer recharge. These are further delineated into sub-categories by quality need or specific use, as described later in this section (see Section 4.5.4).

Including all major categories of reuse in some way in the scenarios is consistent with the observations summarized below about the future projections for each major category:

• Agricultural reuse applications are projected to be significant in every region and in 10 of the 16 city-groups evaluated in this section. Growth in projected demand from this sector is healthy, and expanding the use of RQTSE for crops will reduce reliance on shrinking groundwater supplies. Additionally, the Draft MOWE Regional Planning Reports indicate that farmers can increase yield by irrigating with RQTSE compared to groundwater due to the higher nutrient content of RQTSE.

• Landscape reuse applications are also projected to be significant in almost every region and in almost every city-group. Growth in projected demand from this sector is also healthy. Increasing RQTSE for landscaping will help limit groundwater withdrawals and/or reliance on desalination depending on the current source of water for public and commercial landscaping applications. It is presumed that the nutrient content of RQTSE could also benefit trees, shrubs, grass, and other plants, as the Draft MOWE Regional Planning Reports mention it benefits crops, compared to ground- and desalinated source water.



• Industrial reuse applications are projected to be significant in selected regions and in the city-groups featured in this study. Growth in this sector is projected to be a little higher on average than for agriculture or landscaping. Moreover, a reliable supply of water in the amount and at the quality levels demanded for various industrial processes, from uses not needing tertiary treatment up to uses needing advanced treatment is critical to supporting the economic development of the industrial centers and the cities and regions that depend on them. See Section 1.8 for more detail on current industrial reuse practices.

• Recreational reuse applications are projected to be greater than zero in only three regions, but this may be a reflection of the Draft MOWE Regional Planning Reports’ projection process, and not necessarily a reflection of the level of future opportunities that could be developed. Where it is used, reuse for recreational benefits (see Table 4-2) is important, and as Draft MOWE Regional Planning Reports’ case studies show it can have an attractive cost-benefit ratio (see Figures 4-10 and 4-11).

• Aquifer recharge using RQTSE is projected for only one region in the Draft MOWE Regional Planning Reports, but the reports state that this is a reflection of prioritizing needs in other reuse categories over recharge. Managed aquifer recharge (MAR) is a strategic practice that can assist in restoring water from depleted aquifers that are not directly used for potable purposes, as also discussed in Chapter 5. It is particularly valuable as an alternative to surface discharges to wadis where the resource quickly evaporates, or discharge to the sea where the potential energy investment in low TDS water is lost.

Including all major categories of reuse in more than one scenario is also consistent with the comparative results of the Draft MOWE Regional Planning Reports’ case studies and the ones developed specifically for this study.

Agricultural, landscaping, and industry reuse all have the potential for cost-benefit ratios of less than 1, as illustrated in the Draft MOWE Regional Planning Reports’ case studies (see Figures 4-10 and 4-11 and associated discussion). The other industry-specific case studies also show that reuse can be cost-effective, with relatively short payback periods of 1 to 5 years in five of the six examples presented.

4.5.2 Evaluating Business Case by Individual User, Reuse Use Category, and Reuse Portfolio

There are three scales at which the business case for delivering RQTSE can be evaluated: individual user; reuse category or group; and on a “portfolio” basis. The differences in the business case at these three scales are driven primarily by two sets of factors: user rates, which are often set by use category; and treatment and delivery costs. The Draft MOWE Regional Planning Reports’ case studies assume a future rate structure that is low for agricultural users, at a broad, middle range for landscaping, and at higher rates for industrial users (see the middle panel of Figure 4-15 later in this section).

In contrast, treatment and delivery costs do not correlate to reuse categories quite so explicitly. Treatment costs relate to quality levels—different quality levels are needed for specific agricultural and industrial uses. Delivery costs primarily relate to distance of use from the plant and the extent to which gradient requires pumping technology and energy.

For these reasons, it is important to consider the scale at which a business case should be evaluated.

• The smallest scale—individual user—would compare the rate revenues from that user to the marginal cost of treating (if applicable) and delivering the RQTSE. This scale is the most



limited, and for all but the largest individual users, may not be a practical way to evaluate the reuse business case.

• The middle scale in this discussion—reuse category or defined grouping—would compare the rate revenues from the agricultural sector, for example, to the segregated cost to provide the RQTSE to those defined users in the specified geography. This scale of analysis could be performed for each major sector (e.g., agricultural, landscaping, and industry). This scale offers fewer restrictions and may be informative for capital planning and rate structuring. However, a significant difference in chargeable fees across sectors may result in less attractive or even poor business cases at this scale.

• The largest scale in this discussion—a geographically, system-based, or otherwise defined portfolio—would compare rate revenues from a potentially mixed user group for a defined geographic area or defined portion of the treatment and/or delivery system. This scale of analysis can more effectively match revenues and costs and provides the best opportunity to combine low, medium, and high user fees within the portfolio into a total revenue stream to compare with total costs for the defined portfolio. The likelihood of a positive business case for the entire portfolio would be higher than for evaluations at smaller scales, as profits from higher rate payers offset any losses from lower rate payers. Additionally, this portfolio scale can take advantage of smoothing out any seasonal differences in use across the sectors that result in fluctuating revenue streams.

4.5.3 Summary of the Five Scenarios Developed for this Analysis In light of the projections for types of reuse and an objective to provide some analysis reflecting a sector-based as well as portfolio approach to business case evaluation, the five scenarios described below have been selected for this analysis: all reflect the objective to promote reuse in the industrial sector. Scenarios 1 through 4 afford the opportunity to examine the business case for industrial reuse by itself, or in combination with one other sector: agriculture; landscaping; or aquifer recharge. Scenario 5 affords the opportunity to take a portfolio approach to business case evaluation and includes all major sectors.

• Scenario 1, Industry + Agriculture: Reflects the objectives to promote reuse in the industrial and agricultural sectors and includes 50 percent delivery to each major category, with 25 percent each to restricted and unrestricted farming uses and 25 percent each to restricted and all purpose industrial reuse.

• Scenario 2, Industry + Landscaping: Reflects the objectives to promote reuse in the industrial and landscaping sectors and includes 50 percent delivery to each major category, with 25 percent each to restricted and unrestricted landscaping uses and 25 percent each to restricted and all purpose industrial reuse.

• Scenario 3, Agriculture + Landscaping + Aquifer Recharge: Reflects the objectives to promote reuse for agricultural and landscaping uses, as well as aquifer recharge, at allocations of 40 percent, 40 percent, and 20 percent, respectively.

• Scenario 4, Industry High and Very High Quality Level: Reflects the objective to support specialized industrial and commercial processes that require advanced treatment above tertiary, with an equal distribution among each upper quality level.

• Scenario 5, Multi-Sector Portfolio: Reflects the objective to provide reuse to as many sectors and users within a specific geography as possible, and to evaluate the overall business case for the defined portfolio on the basis of total revenues versus total costs. The scenario assumes the following percentage allocations to major categories: 25 percent agriculture; 25 percent landscaping; 25 percent industry, 12.5 percent recreation; and 12.5 percent aquifer recharge.

• More detail about selected assumptions is provided in Section 4.5.4.



4.5.4 Method, Assumptions, and Inputs for Scenario Definition and Analysis Overview The reuse business case analysis uses ProjectSelectTM, an Excel-based tool, to evaluate the financial and non-financial attributes of the five main reuse scenarios and specified variations. ProjectSelectTM was developed by CH2M HILL, in collaboration with Clean Water Services (Matichich, 2010). The publicly available version of this tool was customized for this analysis by adding in some reuse scenario specification “dashboards” that allow the user to easily enter key assumptions for the reuse scenarios, and by adding in variable cost assumptions for wastewater treatment and reuse delivery that automatically populate the primary scenario cost and revenue tables based on selections made in the custom reuse dashboards. The customized version of ProjectSelectTM will be provided to KAUST.

ProjectSelectTM provides a consistent framework to develop and organize cost and revenue components for each scenario, including capital expenditures, recurring rehabilitation costs, annual O&M costs, and operating revenues or other cost savings. Based on these inputs and the resulting net revenue forecast, the tool calculates various financial metrics for each scenario, including net present value, equivalent annual cost, payback period, and benefit-cost and cost-benefit ratios. ProjectSelectTM automatically generates a wide set of tables and charts to display absolute and comparative financial results.

In addition to evaluating the financial and economic metrics described above, ProjectSelectTM

also supports evaluating and comparing the scenarios using non-financial, non-quantitative criteria. These criteria are selected and defined within the tool and each scenario is rated using a defined scoring system. The criteria are given relative weights: they can be equally important, or some can be more important than others. ProjectSelectTM calculates the total non-financial score reflecting each scenario’s performance based on the non-financial criteria and automatically generates comparative tables and graphics.

Together, the financial and non-financial results are compared across all scenarios to assess the relative strengths and weaknesses of each reuse scenario’s business case. Specific assumptions for system specifications, financial inputs, and non-financial criteria were developed for the scenarios featured in this study, as described below. Recipients of the ProjectSelectTM tool customized for this study will be able to make their own assumptions for the inputs that drive costs, including flow, tariffs, existing WWTPs, and reuse conveyance needs, as well as inputs for non-financial criteria, including number of criteria, definitions, weighting, and scoring.

Assumptions and Inputs Common to All Scenarios and All Variations The following assumptions and inputs are the same for all scenarios.

• Discount rate: 2.5 percent (U.S. Central Intelligence Agency [CIA] World Factbook, 2011).

• Start year: 2011.

• Forecast year: Calendar.

• Period of evaluation: 25 years (This is the same period used in the Draft MOWE Regional Planning Reports’ cost/benefit examples).

• Currency: SR.

• Costs and revenues entered as: uninflated SRs, as opposed to inflated.

• Costs and revenues for project alternatives occur at: start of year, as opposed to mid- or end of year. (The reason for this is to fully reflect initial outlays in the analysis. By following the start of year convention, expenditures and revenues during Year 1 are not discounted; expenditures and revenues in Year 2 receive 1 full year of discounting, and so on for succeeding years.)



• Payback Period Financial Parameter uses: discounted costs, as opposed to undiscounted costs. (The reason for this is so that the time value of money, including the effects of different streams of revenues and expenditures over time for the various scenarios, is taken into consideration when evaluating the length of time before front-end expenditures on balance lead to a positive cumulative cash flow for the first time.)

Additionally, it should be noted that the tables that summarize the results of the financial analysis in ProjectSelectTM display monetary values in millions of SR showing two decimal places (e.g., 234.56 M SR). Cost and revenue inputs used to create the analysis are entered at a more precise level of detail. Some tables in the tool that summarize the cost and revenue inputs to the financial analysis display monetary values in SR (e.g., 1,026,563). Showing two decimals for M SR in the financial results tables or the entire unrounded SR values in tables that summarize cost and revenue inputs does not necessarily imply a corresponding level of precision in these estimates.

Specification of the Five Main Scenarios: Flows, User Allocation, Rates, and Revenues The five main scenarios (also labeled “alternatives” in some of the figures) for this reuse business case evaluation were specified in part as shown in Figures 4-14 and 4-15, which are screen captures directly from ProjectSelectTM.

FIGURE 4-14 Specification of Scenario Flows, Existing Infrastructure, Reuse Quality, and Reuse Allocations Note: The white numbers in the red cells identify the minimum quality level needed for that use. All Purpose Unrestricted Reuse is Level 4; Very High Level Industrial Reuse is Level 6.

The following key assumptions are reflected in Figure 4-14.

• All scenarios (labeled Alt.#) assume the same flow, energy cost, and pre-existing infrastructure at 50,000 m3/day (this flow is representative of a medium-size facility), 0.1875 SR/kilowatt hour (Kwh), and a WWTP treating to tertiary levels (turbidity of less than 5 NTU, and total coliform of less than 2.2 MPN/100 mL).

Development of Reuse Scenarios

This worksheet facilitates identification of scenario characteristics (treatment levels, existing infrastructure, allocation to beneficial use)

Alternative# & NameFlow

(m3/day)Power

(SR/Kwh) Existing Infrastructure1 1. Industry + Agriculture 50,000 0.18752 50,000 0.18753 50,000 0.18754 50,000 0.18755 50,000 0.1875

Alt. # General Purpose of Scenario Corresponding Water Quality (Target Effluent Standards)12345

Allocation to Beneficial Use Categories

RechargeAlt. # AG-RE AG-UN URB-RE URB-UN IND-1 IND-2 IND-3 IND-4 REC-RE REC-UN GW RCHG TOTAL

3 4 3 4 1 4 5 6 2 4 41 25% 25% 0% 0% 25% 25% 0% 0% 0% 0% 0% 100%2 0% 0% 25% 25% 25% 25% 0% 0% 0% 0% 0% 100%3 20% 20% 20% 20% 0% 0% 0% 0% 0% 0% 20% 100%4 0% 0% 0% 0% 0% 0% 50% 50% 0% 0% 0% 100%5 12.5% 12.5% 12.5% 12.5% 12.5% 12.5% 0% 0% 6.25% 6.25% 12.5% 100%

WWTP Exits (Primary+Secondary and Tertiary Level Treatment)WWTP Exits (Primary+Secondary and Tertiary Level Treatment)

Very High Level Industrial ReuseAll Purpose Unrestricted Reuse

Tertiary (Turbidity of less than 5 NTU, total coliform of less than 2.2 MPN/100 mL)

Advanced (Turbidity of less than 0.2 NTU, TDS of less than 10 mg/L)

Tertiary (Turbidity of less than 5 NTU, total coliform of less than 2.2 MPN/100 mL)Tertiary (Turbidity of less than 5 NTU, total coliform of less than 2.2 MPN/100 mL)

All Purpose Unrestricted ReuseAll Purpose Unrestricted ReuseAll Purpose Unrestricted Reuse

Tertiary (Turbidity of less than 5 NTU, total coliform of less than 2.2 MPN/100 mL)

2. Industry + Landscaping

3. Ag + Land + Recharge

4. Industry 3&4

WWTP Exits (Primary+Secondary and Tertiary Level Treatment)WWTP Exits (Primary+Secondary and Tertiary Level Treatment)WWTP Exits (Primary+Secondary and Tertiary Level Treatment)

Agriculture Landscaping Industrial Use Recreational Use

5. Multi-Sector/Use



• All scenarios except #4 assume a reuse quality level of “All Purpose Unrestricted Reuse,” which is the minimum level necessary for unrestricted uses (see “UN” choices in the Allocation to Beneficial Use Categories panel for agriculture, landscaping, and recreation, IND-2 among industrial options, and recharge), but also can be deployed for restricted uses (see “RE” choices or IND-1).

• Scenario #4 assumes a very high reuse quality level is delivered following advanced treatment with turbidity of less than 0.2 NTU, and TDS of less than 10 mg/L for both IND-3 (high) and IND-4 (very high). By comparison, the high quality level also assumes advanced treatment, but with turbidity of less than 0.2 NTU and TDS of less than 100 mg/L.

• The four industrial levels (labeled in Figure 4-14) assume the following uses, for example:

− IND-1, industrial applications with cooling tower that DOES NOT require mist eliminator

− IND-2, industrial applications with cooling tower that DOES require mist eliminator, or other industrial uses that require only tertiary level treatment

− IND-3, high quality industrial uses such as process water and medium pressure boiler feed water (200-500 bar)

− IND-4, very high quality industrial uses such as process water for microchip manufacturing and high pressure boiler feed water (700 bar)

• The relative allocation of the total flow to each reuse subcategory is as shown in the bottom panel of Figure 4-14 in the blue numbers with shading corresponding to the major reuse category, consistent with the rationale described in Section 4.5.3.

The flow allocations result in defined flows by subsector for each scenario, and corresponding subsector-derived user fee revenues based on the assumed rate structure for the main set of scenarios. Figure 4-15 shows the assumptions for each of these as displayed in the customized tool.

FIGURE 4-15 Projected Flows, Rates, and Revenues for the Five Scenarios

For the purpose of this analysis, rates have been assumed for various categories of reuse based on the range of case studies from other reuse contexts. Specifically, the fee structure

Projected Revenues and Other Benefits for Reuse Scenarios

This worksheet estimates annual rate and non-rate revenues associated with each reuse scenario

Projected Flows by Use Category (m 3 )


1 12,500 12,500 - - 12,500 12,500 - - - - - 50,000 2 - - 12,500 12,500 12,500 12,500 - - - - - 50,000 3 10,000 10,000 10,000 10,000 - - - - - - 10,000 50,000 4 - - - - - - 25,000 25,000 - - - 50,000 5 6,250 6,250 6,250 6,250 6,250 6,250 - - 3,125 3,125 6,250 50,000

Projected Rates by Use Category (SR / m 3 )

RechargeAG-RE AG-UN URB-RE URB-UN IND-1 IND-2 IND-3 IND-4 REC-RE REC-UN GW RCHG

0.50 1.00 0.70 2.00 1.00 2.00 2.50 3.00 1.00 2.00

Projected Rate Revenues by Use Category (SR) Sales Volume Reduction Factor: 10.0%


1 2,053,125 4,106,250 - - 4,106,250 8,212,500 - - - - - 18,478,125 2 - - 2,874,375 8,212,500 4,106,250 8,212,500 - - - - - 23,405,625 3 1,642,500 3,285,000 2,299,500 6,570,000 - - - - - - - 13,797,000 4 - - - - - - 20,531,250 24,637,500 - - - 45,168,750 5 1,026,563 2,053,125 1,437,188 4,106,250 2,053,125 4,106,250 - - 1,026,563 2,053,125 - 17,862,188

Industrial Use Recreational Use

Agriculture

Agriculture Landscaping

Agriculture Landscaping



Landscaping



was developed to be consistent with the assumptions made in the Draft MOWE Regional Planning Reports in that the low and high end of each sector’s range was used for restricted and unrestricted qualities, respectively, for sectors with two subcategories (agriculture, landscaping [predominantly urban], and recreation), while for industry, IND-2 and IND-3 rates were set relative to the low and high used for IND-1 and IND-4.

Differentials in rates among categories of users are based on case studies examined. The cost of providing service to various categories of customers has not been used directly in establishing the assumed rates, although it is likely an indirect factor in influencing the rates in the various case study contexts. The extent to which cost of service principles should be used in establishing rates is a policy issue that would best be addressed during implementation planning for a specific reuse option.

Finally, a sales volume reduction factor of 10 percent was used, reflecting an assumption that 90 percent of the produced reuse water makes its way to a paying end user, and 10 percent is lost in the system.

Specification of the Five Main Scenarios: Wastewater Treatment Costs, Reuse Conveyance Costs, and Total Costs This section presents a description of the cost assumptions made for the five scenarios, including screen captures of the summary cost worksheets directly from ProjectSelectTM. As part of the customization of ProjectSelectTM for this analysis, the tool calculates wastewater treatment costs, reuse conveyance costs, and total costs for each scenario. The custom cost worksheets are automatically populated based on user-specified inputs for specific parameters: including flow and quality level for wastewater treatment; and pipeline length, pipe diameter, and total dynamic head (TDH) for conveyance costs. Therefore the assumptions in the cost worksheets change as these inputs change. Additional detail about the fixed and variable cost assumptions that are inputs for wastewater treatment and reuse conveyance costs in worksheets is provided in Appendix B.

Flow-based wastewater treatment cost assumptions (capital and O&M) were developed for six specified treatment levels, although only two were used in this analysis (All Purpose Unrestricted Reuse and Very High Level Industrial Reuse). The wastewater treatment costs for the six levels for a reuse flow of 50,000 m3/d are shown in Figure 4-16 for the four possible assumptions about pre-existing treatment infrastructure that can be included or excluded from the analysis.

Regardless of whether wastewater treatment costs are included in the business case analysis, the cost to deliver the RQTSE to the users always is included. These reuse conveyance costs are calculated based on the defined total flow (50,000 m3/d in this case) and incorporate assumptions about flow rates, total pipeline length, pipe diameter, pipe installation costs (SR/m), pumping efficiency, and pumping costs. Figure 4-17 shows the assumptions used for the main set of scenarios, including in particular 10,000 m of pipe at a diameter of 825mm, and the resulting capital and O&M estimates. To help normalize the scenarios for more direct comparison, the same reuse conveyance assumptions were made for each scenario (it is possible to make different assumptions by changing the values in blue font).

Based on the assumptions made about treatment levels, pre-existing infrastructure to exclude from the analysis, and reuse conveyance, costs are totaled for each scenario. The resulting estimates for the five scenarios in this analysis are shown in Figure 4-18. Because scenarios 1, 2, 3, and 5 all assumed tertiary treatment is in place before reuse, no costs are included for wastewater treatment in those scenarios. Scenario 4, including high and very high quality industrial uses, also assumes tertiary treatment pre-exists but additional costs are incurred to provide the advanced treatment necessary, which are included in the financial analysis and comparisons. Meanwhile, conveyance capital and O&M costs are included for all scenarios (and at the same level consistent with the same assumptions made for all scenarios as shown in Figure 4-17).



FIGURE 4-16 Wastewater Treatment Costs for 50,000 m3/d of Reuse Capacity for Different Pre-Existing Infrastructure Assumptions

FIGURE 4-17 Reuse Conveyance Cost Assumptions

Comparison of Treatment Costs for Hypothetical Reuse Options

This worksheet compares capital and O&M costs for each combination of Treatment Levels and Existing Infrastructure Options

Flow (m3 / day): 50,000Power Cost (SR / Kwh): 0.1875

Capital O&M Capital O&M Capital O&M Capital O&M

Restricted Industrial Reusea 304.92 6.05 26.59 2.05 - - - -

Restricted Recreational Reuseb 306.11 6.08 27.78 2.07 - - - -

Restricted Irrigation Reusec 340.71 6.05 62.39 2.05 - - - -

All Purpose Unrestricted Reused 341.20 6.56 62.87 2.56 - - - -

High Level Industrial Reusee 527.53 12.11 249.20 8.11 249.20 7.82 - -

Very High Level Industrial Reusef610.40 13.74 332.07 9.74 332.07 9.44 96.07 1.62

To compare reuse options, input:

Estimated Treatment Costs (all numbers in millions of SR)

Existing Infrastructure Options

f Very high quality industrial uses such as process water for microchip manufacturing and high pressure boiler feed water (700 bar). Tertiary level treatment and double pass RO for TDS removal.

Treatment Levels (WQ Effluent)

WWTP Does Not Exist

WWTP Exists (Primary and Secondary

Treatment Only)

WWTP Exists (Primary+Secondary and

Tertiary Level Treatment)

WWTP Exists (Primary+Secondary and

Tertiary Level + RO)

a Includes cooling tower that does not require mist eliminator.b Recreation is limited to fishing, boating, and other non-contact recreational activities. No filtration is needed but disinfection requirement is similar to tertiary treatment.c Includes limited human contact uses such as irrigation for nurseries and golf courses.d Includes all purpose uses including urban irrigation, agricultural irrigation, unresitricted recreational uses, and cooling tower that requires mist eliminator and several industrial reuse options that require only tertiary level treatment. e High quality industrial uses such as process water and medium pressure boiler feed water (200-500 bar). Tertiary level treatment and RO for TDS removal and water purification removal.

Flow Conveyance Model

This worksheet estimates CONVEYANCE capital and O&M costs for each reuse alternative based on user input (blue text)

Alternative 1. Industry + Agriculture

2. Industry + Landscaping

3. Ag + Land + Recharge

4. Industry 3&4

5. Multi-Sector/Use

Flowrate, m3/day 50,000 50,000 50,000 50,000 50,000Flowrate, mgd 13.21 13.21 13.21 13.21 13.21Flowrate,m3/sec 0.579 0.579 0.579 0.579 0.579Conveyance Option Pressurized Pressurized Pressurized Pressurized PressurizedPipe Velocity, m/sec 1.3 1.3 1.3 1.3 1.3Pipe Diameter, m 0.75 0.75 0.75 0.75 0.75Pipe Diameter, mm 753 753 753 753 753Selected Pipe Size, mm 825 825 825 825 825Pipe Length, m 10,000 10,000 10,000 10,000 10,000Unit Installed Cost of Pipe, SR/m 4072 4072 4072 4072 4072Installed Pipe Cost, SR 40,720,000 40,720,000 40,720,000 40,720,000 40,720,000Pump TDH, m 50 50 50 50 50Pump TDH, ft 165 165 165 165 165

Pump Efficiency, % 70 70 70 70 70Brake HP 546 546 546 546 546Motor HP 607 607 607 607 607Transfer Pump Station Capital Cost, SR 4,552,500 4,552,500 4,552,500 4,552,500 4,552,500

TOTAL Capital Cost, SR 45,272,500 45,272,500 45,272,500 45,272,500 45,272,500 Electricity Unit Cost, SR/Kwh 0.1875 0.1875 0.1875 0.1875 0.1875Annual Pumping Cost, SR/year 671,250 671,250 671,250 671,250 671,250Annual O&M as % of Capital, SR/year 1.00% 1.00% 1.00% 1.00% 1.00%Annual O&M Cost, SR/year 453,000 453,000 453,000 453,000 453,000

TOTAL ANNUAL COST, SR/year 1,124,250 1,124,250 1,124,250 1,124,250 1,124,250



FIGURE 4-18 Total Costs for Reuse Scenarios

Non-Financial Evaluation Criteria, Weighting, and Scenario Scoring Including non-financial evaluation criteria in the business case analysis helps capture other important considerations that are not readily monetized or quantified. Rules of thumb for developing such criteria are as follows:

• Comprehensive, to include all important non-financial considerations

• Fundamental, to express the essential reasons for interest in the alternative

• Relevant, to address only those consequences that are influenced by comparing alternatives

• Well-defined, to facilitate generation and communication of insights for guiding the evaluation

• Non-redundant, to avoid double-counting of possible consequences

• Measurable, to define objectives precisely and to specify the degree to which objectives may be achieved

• Concise, to limit the collection of information to that required for a reasonable analysis considering the available resources

Following these guidelines, six non-financial evaluation criteria were developed for this analysis. They are identified and described below.

1. Economic Development: The extent to which the scenario supports local, regional, and/or national economic development objectives by making the operations more efficient and/or profitable, and therefore supporting development of additional jobs in the economy. While these benefits are expected to be most pronounced in the industrial and commercial enterprise sectors, reuse could provide opportunities for greater efficiency/profitability, and therefore job growth and other economic benefits in some other sectors as well, such as agriculture.

2. User/Public Acceptance: The extent to which direct users will accept and demand reclaimed water for all or some of their needs, as allowed by/consistent with regulations, regardless of tariff for reuse relative to first use water. Acceptance in this context also includes any potential negative perceptions regarding water quality and related perceptions regarding potential impacts on public health, or nuisance side-effects. This also captures the extent to which direct users’ customers and the general public will accept reclaimed water with no negative impacts on direct users’ business.

3. Ease of Implementation: Reflects the relative convenience of adding or switching completely to reclaimed water, including one-time changes in technology and/or operations, availability of proven equipment to reliably secure appropriate quantities and qualities of reuse water to meet user needs, and ongoing operation, maintenance, and safety activities.

Treatment and Conveyance Cost Estimates by Reuse Scenario

This worksheet summarizes treatment and conveyance cost components for each alternative

Type of Expenditure: One-time Annual Periodic Periodic One-time Annual

Alt. # General PurposeFlow

(m3/day) Existing InfrastructureTreatment

CapitalTreatment

O&MTreatment R&R (5 yrs)

Treatment R&R (10 yrs)

Conveyance Capital

Conveyance O&M

1 All Purpose Unrestricted Reuse 50,000 WWTP, Tertiary (no RO) - - - - 45,272,500 1,124,250



4 Very High Level Industrial Reuse 50,000 WWTP, Tertiary (no RO) 332,066,250 9,438,750 7,500,000 22,612,500 45,272,500 1,124,250


Estimates by Cost Category (SR)



4. Temporal Use/Payment Pattern: Since the reclaimed water will be produced on a relatively even pace year-round, scenarios with less seasonal variation in demand are preferred to ones with more seasonal variation. Additionally, user profiles with more regular payment streams and greater likelihood of meeting financial commitments are favored over those with less regular or lumped payment streams and greater uncertainty regarding their reliability of meeting financial commitments.

5. Regulatory Support/Enforcement: In general, it is expected that all uses included in the scenarios will be supported in regulation; however, some may be more supported than others, or may have clearer requirements than others (it also is assumed that the current draft rules will be implemented substantively as they exist now). Additionally, some types of reuse may be easier to inspect and enforce than others (e.g., where use is distributed to a few large customers rather than to many distributed customers where ability to verify compliance is more costly and problematic).

6. Community Benefit: The extent to which the

community is aware of and values the reuse, with the knowledge that a scarce resource is being sustainably reclaimed to reduce local and national dependence on groundwater and desalination, and where reuse is considered likely to free up these other water resources to meet other identified community needs for water.

For scoring purposes, a 10-point scale was developed for each criterion, generally corresponding to the narrative ratings shown in Table 4-12. Best professional judgment was used in deciding how to apply these across the different criteria to most accurately reflect the relative relationships among the scenarios. The raw (i.e., unweighted) scoring results are displayed in Figure 4-19.

FIGURE 4-19 Narrative Rating for Each Criterion and Each Scenario and Corresponding Raw Numerical Score Note: Weighted component scores and full results are shown in Section 4.6.2.

Non-Financial: Project Alternative Evaluation, Scores, and Results

This worksheet allows the user to evaluate each project alternative against the chosen performance scale, and displays the results of the analysis

Type of Performance Scale Specified: Ordinal Ordinal Ordinal Ordinal Ordinal Ordinal

Economic Development

User/Public Acceptance

Ease of Implementation

Temporal Use/Payment

PatternRegulatory

Support/EnforceCommunity

Benefit

1. Industry + Agriculture Moderately

above average Moderately


above average Average

performance Average

performance Moderately

above average

2. Industry + Landscaping Moderately






above average

3. Ag + Land + Recharge Average

performance Average

performance Average


below average Moderately

below average Considerablyabove average

4. Industry 3&4 Considerablyabove average

Considerablyabove average




Averageperformance

5. Multi-Sector/Use Moderately

below average Average


below average Average

performance Average


above average

Calculate Raw Scores: this section determines the raw score for each non-financial criterion and project alternative based on previous input from user1. Industry + Agriculture 7 7 7 5 5 72. Industry + Landscaping 7 7 7 7 7 73. Ag + Land + Recharge 5 5 5 3 3 104. Industry 3&4 10 10 10 10 10 55. Multi-Sector/Use 3 5 3 5 5 7

RESET Evaluation

TABLE 4-12 Scenario Scoring System

Narrative Rating Numerical Score

Considerably above average performance

10

Moderately above average performance

7

Average performance 5

Moderately below average performance

3

Considerably below average performance

1



4.6 Detailed Evaluation of the Five Defined Reuse Scenarios This section presents the business case evaluation for the five scenarios using the assumptions described above, featuring the built-in ProjectSelectTM financial metrics, non-financial metrics as specified for these scenarios, and comparative graphics. Financial results are presented first, followed by the non-financial results. Overall findings and recommendations based on the scenario evaluation, and the other information presented in this chapter, are provided in Section 4.7.

It should be noted that because ProjectSelectTM was originally developed to compare alternatives that exclusively or predominantly involve costs and not revenues, many of the charts feature costs as positive above the x-axis, and revenues as negative below the x-axis. Where deemed useful, reminders of this presentation feature are included in figures.

4.6.1 Summary of Financial Results All of the scenarios have favorable financial metrics with respect to positive net present value (NPV), relatively low payback periods, high benefit-cost ratios (B/C), and low cost-benefit ratios (C/B), as seen in Figure 4-20. The two scenarios including industrial allocations with either agriculture or landscaping have the best metrics, followed by the multi-sector/use scenario in a close third place, the agriculture-landscaping-recharge scenario in fourth place for all but NPV, and the high quality level industrial scenario with a noticeably longer payback period and less favorable (but still better than break-even) B/C and C/B ratios. It should be remembered, however, that the high level industrial scenario is at a disadvantage relative to the others in that additional capital investment in advanced treatment is needed to support this scenario, while the other four do not require additional wastewater treatment capital investment.

FIGURE 4-20 Summary of Financial Results for the Scenarios

Note: NPV and Equivalent Annual Cost are given as Million SR; Discounted Payback is number of years. Green shading identifies the best alternative, peach shading identifies the second best. The C/B ratio is provided in addition to the B/C ratio because the C/B ratio is used in the Draft MOWE Regional Planning Reports’ case studies.

ProjectSelectTM also automatically generates charts for each financial metric shown in Figure 4-20 except the C/B ratio, which was manually added for this study, to support visual comparisons of the results. These are presented in Figure 4-21.

Comparing the net cash flows for all scenarios shows a similar, but not identical, relative relationship as in the NPV values. Figure 4-22 shows that the four scenarios not involving high quality industrial reuse are all clustered together at the 28.53M SR marker, as their initial costs (as expected given their conveyance costs) are all the same and they have no WWTP capital costs. Also consistent with the NPV relationships, the high level industrial scenario incurs significant costs at the outset, shown in the 342.73M SR marker. Consistent with the relatively short payback periods for the scenarios not involving high level industrial reuse (see Figures 4-20 and 4-21), the lines for these four scenarios cross below the x-axis, into positive net cash flows very quickly. The high level industrial scenario crosses the x-axis into positive net cash flow territory later (see yellow line) but ultimately has the second-best net cash flow at 412.48M SR. The high level industrial reuse scenario’s relative ranking in NPV and net cash flows differ because this scenario has a higher level of recurring capital costs than the others,

Project Alternative Net Present ValueEquivalent Annual Cost

DISCOUNTED Payback

Benefit - Cost Ratio

Cost-Benefit Ratio

1. Industry + Agriculture 282.46 (3.61) 2.67 5.25 0.19 2. Industry + Landscaping 375.51 (3.61) 2.06 6.65 0.15 3. Ag + Land + Recharge 194.05 (3.61) 3.69 3.92 0.26 4. Industry 3&4 222.48 (34.22) 13.71 1.35 0.74 5. Multi-Sector/Use 270.82 (3.61) 2.77 5.07 0.20



and because the net cash flows are based on undiscounted dollars, and so the gross cumulative revenues over time have a greater impact than they do in the NPV analysis, where they are discounted.

FIGURE 4-21 Graphic Presentation of Financial Parameters for Each Scenario

FIGURE 4-22 Net Cash Flows for the Reuse Scenarios

Note: Negative flows appear above the x-axis and positive flows appear below the x-axis.

282.46

375.51

194.05

222.48

270.82

-

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

Industry + Agriculture Industry + Landscaping Ag + Land + Recharge Industry 3&4 Multi-Sector/Use

Mill

ions

of S

R

Financial Parameter: Net Present ValueComparison of financial results across project alternatives

Net Present Value

(3.61) (3.61) (3.61)

(34.22)

(3.61)

(40.00)

(35.00)

(30.00)

(25.00)

(20.00)

(15.00)

(10.00)

(5.00)

-


Mill

ions

of S

R

Financial Parameter: Equivalent Annual CostComparison of financial results across project alternatives

Equivalent Annual Cost

2.67 2.06

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27.92 22.99 32.60

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Industry + Agriculture Industry + Landscaping Ag + Land + Recharge

Industry 3&4 Multi-Sector/Use



Figure 4-23 presents net cash flows for the individual scenarios; recurring costs can be seen in these charts.

FIGURE 4-23 Net Cash Flows Charts for the Individual Scenarios Also Showing Capital Investments, Operating Costs, and Revenues

Note: Negative flows appear above the x-axis and positive flows appear below the x-axis.

4.6.2 Summary of Non-Financial Results ProjectSelectTM tabulates and displays the total component scores for each criterion based on the scoring and weighting assumptions discussed in Section 4.5.4 and shown in Figure 4-19. Figure 4-24 presents the tabular results and Figure 4-25 presents the same results graphically. Summary observations are provided following Figure 4-25.

27.92

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Capital Investment Operating Costs Revenues Cumulative NCF

Graphical summary of undiscounted costs and revenues for specified alternative

Choose Project Alternative:

22.99

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32.60

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28.53

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342.73

204.31

38.78

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FIGURE 4-24 Component Weighted Scores for Non-Financial Criteria Note: This is the bottom panel of the worksheet shown in Figure 4-19. See in the pale blue shaded row the priority weighting assigned to each criterion. In this case they are equally weighted at 16.7% such that the sum of the weights equals 100%. Total scores are shown in the dark green label, and the highest score—in this case 9.17 for the Industry 3&4 scenario—is also shaded dark green. To the right of the scores, each score as a percentage of the highest score is shown.

FIGURE 4-25 Graphic Presentation of Component Weighted Scores for Non-Financial Criteria Note: The values inside each bar segment are the weighted scores, which are 0.167 times the raw score. The five possible scores of 1, 3, 5, 7, and 10 thus translate into possible weighted component scores of 0.17, 0.50, 0.83, 1.17, and 1.67, respectively.

Overall, the high quality reuse “Industry 3&4” scenario scored the highest on the non-financial criteria, followed by the two other scenarios with significant industrial reuse (at 50 percent each). The agriculture-landscaping-recharge scenario was fourth best, and the multi-sector scenario scored lowest, but still with a score close to the mid-range. Some reasons for these results are as follow:

Non-Financial: Project Alternative Evaluation, Scores, and Results

This worksheet allows the user to evaluate each project alternative against the chosen performance scale, and displays the results of the analysis

Type of Performance Scale Specified: Ordinal Ordinal Ordinal Ordinal Ordinal Ordinal

Economic Development

User/Public Acceptance

Ease of Implementation

Temporal Use/Payment

PatternRegulatory

Support/EnforceCommunity

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Weighted Score and Results: this section applies the user-specified weights and develops the overall Non-Financial Score for each project alternativePriority Weighting: 16.7% 16.7% 16.7% 16.7% 16.7% 16.7% Total Score % of High

1. Industry + Agriculture 1.17 1.17 1.17 0.83 0.83 1.17 6.33 69%2. Industry + Landscaping 1.17 1.17 1.17 1.17 1.17 1.17 7.00 76%3. Ag + Land + Recharge 0.83 0.83 0.83 0.50 0.50 1.67 5.17 56%4. Industry 3&4 1.67 1.67 1.67 1.67 1.67 0.83 9.17 NA5. Multi-Sector/Use 0.50 0.83 0.50 0.83 0.83 1.17 4.67 51%

RESET Evaluation

1.17 1.17 0.83 1.67

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Non-Financial Evaluation of Project Alternatives Comparison of total weighted score and components by criterion

Economic Development User/Public Acceptance Ease of Implementation Temporal Use/Payment PatternRegulatory Support/Enforce Community Benefit Total Score

* The highest overall score identifies the most desirable project alternative based on the specified non-financial critieria



• The Industry 3&4 scenario received the highest possible score on all criteria except community benefit, which was designed to favor more visible uses. Consistent with standard practice for these types of scoring, the other scenarios were then scored relative to this best situation.

• Industry + Landscaping received the second highest possible score on all criteria. This is because while the industry component scored the highest individually, the landscaping component scored about average individually, except for community benefit, for which the individual sector scores are reversed. This resulted in splitting the difference and scoring the package as moderately above average on all criteria.

• Industry + Agriculture scored slightly below the Industry + Landscaping scenario. These two scenarios were deemed equal on four of the six criteria, but the Industry + Agriculture scenario received lower scores for “Temporal Use/Payment Pattern” and “Regulatory Support/Enforcement.” This is because it is expected that agricultural users may not pay until after their harvest, resulting in a less-steady revenue stream, and it is believed that agricultural operations may be more difficult to inspect than urban or commercial landscaping operations due to the relative geographic spread or concentration.

• The Ag+Land+Recharge scenario generally scored lower than others except multi-use because the individually higher scoring industrial uses were not present to boost the agricultural and landscaping component’s scores. Notably, this scenario scored the highest possible on community benefits, which (as noted above) is designed to reflect the visibility of the reuse among the general public.

• The Multi-Sector/Use scenario, although the lowest total score among the group, still has an overall score that can be interpreted as about average. Some of the individual component scores are lower, in part because the higher scoring industrial component was proportionately less (only 25 percent by allocation). This is particularly true for the economic development criterion. This scenario also received a relatively lower ease of implementation score, in part because 75 percent of the allocation would need some personal precautions and/or special equipment. Notably, this scenario scored the same as the Industry + Agriculture scenario on temporal use/payment pattern and regulatory support/enforcement and the same as both Industry +Agriculture and Industry + Landscaping for community benefits.

4.6.3 Summary of Overall Scenario Results Together, the financial and non-financial analysis of the five scenarios shows that a wide variety of reuse portfolios can: (1) be economically viable without subsidies under a sufficient tariff structure; and (2) deliver important non-financial benefits to the users, reclaimed water providers, and larger community. This is shown in Figure 4-26, which is similar to Figure 4-20, but includes the non-financial scores as well.

The main financial differences across the scenarios examined here relate to the assumed rate structure, the relative proportion of low, medium, and high rate-payers, and whether or not advanced treatment is necessary and included in the financial analyses. The main non-financial differences relate to greater relative benefits for the chosen criteria delivered by industrial uses compared to landscaping and agricultural uses.

Certainly, the five scenarios presented here are necessarily generalized to examine the relative relationships among reuse portfolios with distinctly different reuse allocations that might be found in KSA localities. In reality, the reuse water provider and its prospective customers will have ample opportunity to collaborate in identifying opportunities for reuse and planning cost-effective treatment and delivery systems. This discussion of the scenario results is not intended to imply that communities should choose among these scenarios as



scoped here, but rather that communities should develop the reuse portfolio that best matches their needs and opportunities.

FIGURE 4-26 Summary of Financial and Non-Financial Results for the Scenarios Note: NPV and Equivalent Annual Cost are given as Million SR; Discounted Payback is number of years. Green shading identifies the best alternative, peach shading identifies the second best. See Figure 4-20 for the C/B ratio. Note that all B/C ratios are greater than 1.0, indicating the scenario is profitable, and payback periods are relatively short. Four of the five scenarios have total non-financial scores which can be interpreted as average (=5) or above, while the fifth is very close to an overall average score.

In fact, given the limited recent and ongoing experience with reuse in some geographies within the study area, the range of reuse opportunities will likely be established over time as an equilibrium/balance point is reached as the utility systems more aggressively market the availability and quality of reuse opportunities and existing and potential additional customers gain experience and a comfort level in using reuse water to meet appropriate portions of their water needs. Local governments and MOWE will also need to facilitate a matching process for reclaimed water to be used for various users and support the education of customers in its use.

While common assumptions had to be made for this study to provide a consistent framework for considering the NPV, payback, and benefit-cost relationships of the identified scenarios, utility-specific and customer-specific considerations will likely ultimately play a significant role in determining where there is a likely match between utility and customer expectations and goals. For example, the fact that Scenario 4 (Industry 3&4) scores strongly in terms of contribution to non-financial criteria and ultimately has a net positive cash flow that is favorable relative to other scenarios (see Figures 4-22 and 4-23 and related text) suggests that this could be a viable approach even though the standard financial metrics such as NPV and benefit-cost ratio show this scenario as scoring lower than the other scenarios.

Since a key driver affecting the standard financial metrics in these comparisons is whether or not there are substantial front-end costs, several considerations could result in a scenario such as Industry 3&4 still being a viable strategy. One way is that the industries that would benefit from the availability of the high quality reuse water provided for this scenario might be willing to work with the utilities to help provide a revenue stream that makes it financially feasible for both the utility and customer to implement this reuse strategy.

Another example of how a scenario such as Industry 3&4 could see improved metrics is through more detailed context-specific feasibility studies of the costs of providing reuse water. Such studies may indicate that there are economies of scale at certain “plateau points” in the implementation of required treatment facilities that would allow utilities, if provided contractual commitments for purchasing water at or near those plateau points, to assume lower costs for providing reuse water than were assumed in the higher-level evaluation conducted in this study.

The fact that there are positive benefit-cost ratios and encouraging payback periods for these preliminary studies with a reasonable range of high-level assumptions on costs and usage, suggests that there is merit going forward for both utilities and potential customer

Financial and Non-Financial Results

Project Alternative Net Present ValueEquivalent Annual Cost

DISCOUNTED Payback


Non-Financial Total Score

1. Industry + Agriculture 282.46 (3.61) 2.67 5.25 6.33 2. Industry + Landscaping 375.51 (3.61) 2.06 6.65 7.00 3. Ag + Land + Recharge 194.05 (3.61) 3.69 3.92 5.17 4. Industry 3&4 222.48 (34.22) 13.71 1.35 9.17 5. Multi-Sector/Use 270.82 (3.61) 2.77 5.07 4.67



groups to think creatively in terms of such usage, cost, and revenue conditions that would provide a framework for even more mutual benefit/gain sharing.

Reuse programs well-tailored for specific communities clearly have the potential to score well on financial and non-financial criteria—potentially even higher than some of the scenarios presented here. Site-specific planning can take advantage of economies of scale, the benefits of decentralized systems where appropriate, optimizing piping and delivery systems, and co-location of users in a way that cannot be reflected in the scenarios presented here. Additionally, a systems approach will enable providers to optimize their rate structure for their specific user base, charging high rates for high quality, keeping reuse rates competitive with first use water rates, and keeping rates lower for some uses and users where necessary to encourage demand for reclaimed water.

4.7 Findings and Recommendations The analyses presented in this chapter demonstrate that the commitment to significantly expand the availability of RQTSE for a wide variety of uses will be critical to meeting future water demand, can be cost-effective for users, and can be profitable for providers. Capturing these business opportunities and supporting overall resource sustainability goals will depend in large part on the following:

• Instituting rational tariff structures for both first use water and RQTSE that support the significant capital and operational investments that will be made

• Creating the proper economic relationship between different sources of water to make RQTSE sufficiently attractive as a source, and to recognize differences in ability and willingness to pay in a manner consistent with social and cultural considerations

The findings directly derived from the information and analysis presented in this chapter have important implications for future planning and resource allocation processes and decisions, in particular for taking an integrated systems planning and management approach (systems approach) for the relevant scope and scale. The findings themselves and their larger implications also point to specific actions and activities that should be supported and launched where not already underway to ensure that local, regional, and national goals for reuse and sustainable resource management are met.

Highlights of the major findings, broader implications, and recommendations are discussed in turn below.

4.7.1 Highlights of Major Findings The various sections of this chapter demonstrate the following:

• The macro-case for reuse is compelling given the projected depletion of groundwater resources, the very high cost of desalinating seawater driven in part by its high energy needs, and the economic irrationality of sending treated wastewater back to the sea given these scarcity and cost considerations.

• The potential demand for RQTSE is projected to triple between 2010 and 2035, with the most significant growth occurring between now and 2025. Significant growth in demand is projected for almost every region and city, across all five categories of reuse: agriculture; landscaping; industry; recreation; and recharge.

• Almost every region and city shows significant future reuse demand for agricultural, landscaping, and industrial use even though there is variability in the relative demand for RQTSE from each user category across regions and cities, due to differences in geography, demographics, and economic activities.



• The compilation of the Draft MOWE Regional Planning Reports’ case studies shows that all but 3 of the 64 proposals could be implemented profitably, with C/B ratios less than 1, and that 54 could be implemented with C/B ratios of 0.6 or less. These examples also show that while landscaping and industrial reuse projects among this set are generally more cost-effective than agricultural ones, agricultural reuse projects can have C/B ratios within the range for the other two types of reuse.

• The individual case studies presented show that reuse can be particularly attractive for industrial users with relatively short payback periods. Some of these cases also demonstrate that other resource conservation and recycling opportunities can exist for WWTPs that offer significant cost savings and/or specific revenue streams.

• The five reuse scenarios developed and evaluated for this study using ProjectSelectTM collectively show that all distinctly different reuse portfolios defined by variable flow allocation to the five major categories can be financially viable, with many profitable in the near term, and also deliver important non-financial benefits to users, providers, and the community. Individually, the scenarios demonstrate the opportunity and need to tailor actual WWTP and reuse systems to specific geographic realities and market opportunities; the scenarios are not intended to imply that any one scenario is best in all circumstances.

4.7.2 Broader Implications and Other Findings While the results of the scenarios analysis show that a wide range of reuse portfolios can be financially viable on key performance metrics, including positive NPV, acceptable payback period, and better than break-even B/C and C/B ratios, achieving those favorable metrics in practice will depend on integrated planning, capital decisions, continued collaboration with potential customers and other stakeholders, and coordinated management.

In fact, the NWC’s taking responsibility for water, wastewater, and reuse services in the six largest cities—Riyadh, Jeddah, Makkah, Al Taif, Al Madinah, and the Greater Dammam area—provides an excellent opportunity to demonstrate the power of integrated master plans to optimize and leverage the three services during the development, construction, and implementation phases. In particular, NWC will have the opportunity to implement (or continue to implement) the strategies listed below that will help maximize the financial and non-financial benefits of reuse for all involved:

• Coordinate rate structures for water, wastewater, and RQTSE to create the necessary relative cost relationships between the three to provide sufficient economic incentives for conservation, recycling, and reuse.

• Implement a public education and awareness program and user-targeted RQTSE marketing programs to fully develop the projected demand in all user categories present in the geographic area associated with a given WWTP-RQTSE system.

• Collaborate with user groups and individual users to identify and capture opportunities to match different RQTSE levels to specific needs, to take advantage of co-location, and otherwise optimize conveyance systems to minimize those costs, and enter partnerships to share capital and/or O&M costs where necessary to offer a quality level that could not otherwise be provided.

• Fully explore and compare system alternatives with respect to their degree of centralization versus decentralization. Depending on geography and demand profile, one or the other extreme, or a mix may be the best plan. Centralized facilities offer economies of scale for treatment, but could require significant conveyance infrastructure and costs, which in some cases might be beyond a feasible distance. Decentralized



facilities, which provide either significant treatment or just enough additional treatment to meet the local need, could be very cost-effective in some situations.

Beyond the six cities, MOWE can also continue to promote reuse in other cities and regions. The scenarios presented in Sections 4.5 and 4.6 offer similar lessons and demonstrate similar opportunities for integrated planning and development of water, wastewater, and reuse systems outside of cities, though the geographic and coordination challenges may be somewhat greater. With sources and uses in a less concentrated geography, the emphasis outside cities should be focused on matching potential sources of RQTSE with potential customers and developing the necessary education, marketing, collaboration, and capital initiatives to match those partners where it can be financially viable to do so. A key component of these efforts would be to actively and aggressively promote RQTSE over groundwater. A combination of general education, rational prices for groundwater versus RQTSE, and total farm financial analysis to show the yield benefits of RQTSE will be necessary to meet reuse goals in agricultural areas outside of the cities.

The final implication featured in this section is based on an aspect of the scenarios that could not be directly evaluated on financial metrics: the importance of greatly expanding MAR. Because there is not a standard practice in KSA to emulate, the rate structure used for the scenarios did not include any tariff for recharge, despite the inclusion of that reuse in two of the five scenarios.

MAR offers the opportunity to strategically and purposefully store RQTSE for later use when supply exceeds demand. Perhaps some type of “options” rate structure could be developed for users willing to pay to “bank” RQTSE in an aquifer that they could call for later. This could involve the option holder paying a lower fee (per m3) at the time the RQTSE is stored than the option holder would pay later, which might represent partial or full payment for the volume delivery the option holder can request at a later date. At the same time, the owner of the stored RQTSE should be able to value it in some way on its balance sheets that supports the financial viability of storing it even if no specific user makes a claim on it. At a minimum, where at all preventable, TSE should not be discharged to the sea (where it would only conceptually return to a desalination plant), or to wadi drainages where it would evaporate without any meaningful recharge benefits. Excess TSE should be recharged to non-potable aquifer areas to immediately preserve precious water resources and the energy invested to produce water with relatively low TDS.

4.7.3 Additional Recommendations to Support Development of Reuse-Related Business Opportunities

In addition to the above strategic recommendations, enhancements to the quantity and quality of water-related data are needed to fully support achievement of water resource management objectives in KSA generally, and more specifically the achievement of reuse expansion goals. This recommendation is similar to that made in Chapter 1, and covers the need for detailed and accurate information about water use, wastewater generation, groundwater withdrawals, and reuse quantities and allocations. This is consistent with the National Water Database discussed in Chapter 7, and recently recommended in a presentation by MOWE’s Deputy Minister (Al-Saud, 2011).

The type of database envisioned will be necessary to fully support the integrated systems planning and management approach discussed above that is key to successfully implementing reuse programs wherever they can deliver financial and non-financial benefits to users, providers, and the recipient communities.

Follow-on efforts to this study should be launched to further explore the opportunities and constraints on financially viable reuse programs. Input assumptions for this study reflect a reasonable range of system, financial, cost, and revenue variables. Specific opportunities to expand reuse will result by locating situations where utilities and customers achieve financial



and non-financial benefits based on their specific goals, objectives, and evaluation frameworks, including their specific cost of money in light of current resources, access to capital markets, and other draws on their financial resources. As a follow-on effort, it is recommended that more detailed studies be conducted based on defined needs for users in delineated geographies, where opportunities to provide specific volumes and quantities of reuse water at qualities required by identifiable candidate customers can be used to refine the assumptions of required capital and O&M costs and revenue/rate opportunities. As noted above, opportunities for creative cost-sharing and gain-sharing might be explored to further enhance the opportunities for mutual benefit to utilities and potential customers.

4.8 References Al-Hazmi, A. and A. Jaffar. 2006. SABIC Wastewater Conservation and Reuse. Proceedings of Saudi Arabian Water Environment Association Workshop. December 5-6, 2006. Al-Khobar, Saudi Arabia.

Al-Saud, Dr. Mohammed. 2011. The Importance of Developing Sustainable Water Resources in the Kingdom: Strategies for the Future. Jeddah. 31-05-2011.

Cote, P., S. Siverns, S. Monti. 2005. Comparison of Membrane-based Solutions for Water Reclamation and Desalination. Desalination. 182; pp 251-257.

CH2M HILL. 2011. Summary Review of Design-Build Proposals for Al Kharj Road STP Phase III. March 2011.

ItalConsult. 2009-2010. Wastewater Reuse Planning Reports prepared for the Ministry of Water and Electricity (MOWE) for each of the 13 Regions:

• Al Baha; February 2010 • Makkah; October 2009 • Al Jouf; July 2009 • Najran; August 2009 • Assir; December 2009 • Northern Borders; June 2009 • Eastern Province; January 2010 • Qaseem; October 2009 • Hail; July 2009 • Riyadh; December 2010 • Jizan; March 2010 • Tabouk; July 2009 • Al Madinah; January 2010

Ostara. 2011. http://www.ostara.com/.

Japan External Trade Organization（JETRO). 2009. The Study on Wastewater Treatment and Water Reuse in Saudi-Aramco, Saudi Arabia. Prepared by JETRO Water Re-use Promotion Center Sumitomo Corporation.

Kajenthira A. L.D. Anadon and A. Siddiqi. 2011. The Case for Cross-Sectoral Water Reuse in Saudi Arabia: Bringing Energy into the Water Equation. Proceedings of 17th Annual International Sustainable Development Research Conference. May 8-10, 2011. Columbia University, New York, NY, USA.

Kingdom of Saudi Arabia Ministry of Agriculture (MOA). 2001. Using Treated Water for Irrigation Controls: Conditions, Offences and Penalties.

Kingdom of Saudi Arabia Presidency of Meteorology and Environment (PME). 2001. General Environmental Regulations and Rules for Implementation. October 15, 2001.

Matichich, Michael. 2010. Evaluating investment options: Water resource management utility develops freeware that transportation, facilities, and virtually any other infrastructure operation can use. Public Works Magazine. December 2010. http://pwmag.com/industry-news.asp?sectionID=760&articleID=1465624&artnum=1. A link to the freeware version of ProjectSelectTM is provided at the end of this article.



National Water Company (NWC). 2011. Jeddah City Business Unit, Wastewater Sludge Management Plan.

Sharqawy, M.H. 2011. Mobile Solar Desalination System for Water Production in Arid and Off Grid Areas. Proceedings of International Desalination Association Conference in Portofino, May 16-18, 2011.

U.S. CIA World Factbook. 2011. See at https://www.cia.gov/library/publications/the-world-factbook/fields/2207.html. See also http://www.indexmundi.com/saudi_arabia/central_bank_discount_rate.html .

Wafeer. 2011. http://www.wafeer.net/page1251216.aspx.

STRATEGIC STUDY

Chapter 5: Aquifer Recharge and Recovery

5.1 Introduction Managed aquifer recharge (MAR) was defined by Dillon (2005) as the intentional banking and treatment of waters in aquifers. The term managed aquifer recharge was introduced as an alternative to artificial recharge, which has the connotation that such use of the water was, in some way, unnatural (Dillon, 2005). MAR can be either a storage technology, treatment technology, or both. With respect to reclaimed water, MAR can be used to store seasonally available excess water (intra-annual supply management), to strategically store currently available excess water for future use, or to serve as a treatment (polishing) step in a multiple-barrier approach to reclaimed water reuse.

Other similar terms have been introduced for MAR techniques. The term aquifer recharge and recovery (ARR) refers to the artificial recharge of water into an aquifer and its later recovery for subsequent use with a primary goal of water treatment. ARR of reclaimed water can be very cost-effective wastewater treatment technology. The term managed underground storage (MUS) was introduced by the U.S. National Research Council (2008) to denote “the purposeful recharge of water into an aquifer system for intended recovery and use as an element of long-term water resource management.”

MAR includes a variety of techniques, some of which are applicable to RQTSE storage and treatment (Table 5-1). Aquifer storage and recovery (ASR) is an important MAR technique, which was defined by Pyne (1995) as: The storage of water in a suitable aquifer through a well during times when water is available, and the recovery of the water from the same well during times when it is needed.

TABLE 5-1 RQTSE MAR Techniques

Technique Description

ASR Injection of water into an aquifer and its later recovery using wells.

ARR Recharge of water into an aquifer and its later recovery for use with a primary goal of water treatment.

Aquifer recharge using wells Injection of water into an aquifer with the goal of increasing aquifer water levels.

Aquifer storage, transfer, and recovery (ASTR)

Injection of water into an aquifer and its recovery using different, nearby wells with the goal of using flow through the aquifer as a treatment process.

Salinity barrier system Injection or recharge of water by infiltration to create a hydraulic mound and thus prevent saline-water intrusion.

Soil-aquifer treatment (SAT) Infiltration of wastewater into shallow basins with the goal of improving its quality by vadose and saturated zone processes. As originally defined, the flow of water is controlled and restricted to a limited area of the aquifer.

CHAPTER 5: AQUIFER RECHARGE AND RECOVERY

5-2 STRATEGIC STUDY

ASR, like other types of MAR systems, takes advantage of the large storage volumes present in aquifers and, in the case of systems recharging non-potable waters, the natural contaminant attenuation processes that occur in aquifer systems.

A variety of different types of water are stored or treated in MAR systems, including:

• RQTSE (also referred to as reclaimed water)

• Potable water (including desalinated water)

• Surface water (treated to varying degrees)

• Stormwater

• Raw groundwater (inter-aquifer systems)

MAR using RQTSE has the advantage of potentially allowing for the greatest beneficial use of the water, which might otherwise go to waste and present a disposal problem. MAR techniques can also be intentionally used to improve the quality of the water. The principal challenge of MAR using RQTSE is ensuring that public health, water supplies, and the environment are protected.

5.1.1 Potential Benefits of RQTSE MAR and ASR in KSA All freshwater resources are precious in water-scarce regions such as KSA and other countries in the Middle East and North Africa (MENA) region. Very limited additional renewable fresh groundwater and surface water resources are available to meet current and projected future demands. Only two large-scale sources of additional water are available to accommodate future increases in demand: desalination and wastewater reuse. Desalination can provide an essentially unlimited supply of additional freshwater, but at a relatively high cost. Agricultural irrigation is by far the greatest water use in KSA, and desalinated water is too expensive for many agricultural uses. Reuse of RQTSE is thus the only available source of large volumes of relatively inexpensive freshwater, especially for non-potable uses. Increased collection, treatment, and reuse of wastewater are important for controlling the rising groundwater tables occurring locally in some KSA cities, which may exacerbate flooding (Al Motairi, 2001).

The primary value of RQTSE MAR in KSA is as a component of integrated water resource management (IWRM). Reclaimed MAR can allow for greater value to be obtained from RQTSE resources, which in turn can lead to more effective utilization of all water resources. In particular, increased beneficial use of RQTSE allows for more valuable fresh groundwater and desalinated water resources to be put to higher value (potable) uses.

ASR and related technologies can be used to store excess RQTSE (i.e., flows in excess of current reuse water demands) that would otherwise be disposed of, with potential associated environmental impacts. Water could be stored to manage intra-year variations in supply and demand or on a long-term strategic basis for use in the future when demands increase. The availability of a reliable source of high-quality RQTSE could allow for agricultural development in areas lacking an available fresh groundwater supply.

MAR technologies, such as ARR, may also be used as a treatment element in a multi-barrier approach to wastewater reuse. Numerous sources of data indicate that the concentrations of pathogens and many chemical contaminants can be greatly reduced using MAR systems, resulting in a substantial improvement in RQTSE quality (Section 5.4). Placing RQTSE in a natural environment (in this case an aquifer) also tends to reduce its stigma of being a

Benefits of Water Reuse

Reuse of RQTSE is thus the only available source of large volumes of relatively inexpensive freshwater, especially for non-potable uses


STRATEGIC STUDY 5-3

wastewater product and can thus increase the social acceptance of reuse. Discussions with several date palm farmers in KSA indicated that they would not be willing to use reclaimed water for crop irrigation because of this stigma.

More specialized MAR systems can be used to manage specific water resources problems. For example, RQTSE can be used in salinity barrier systems to prevent or reverse saline-water intrusion in coastal areas, and thus protect valuable fresh groundwater resources. Increased beneficial reuse of RQTSE reduces the economic and environmental costs associated with its disposal.

5.1.2 General Requirements for Successful RQTSE MAR and ASR ASR is a storage technology. As such, general requirements include a supply of excess RQTSE that can be stored and a demand for the stored water. As a result, RQTSE ASR in KSA currently has potential applications primarily in major urban areas with large wastewater treatment facilities and RQTSE flows. Four areas were investigated in this study:

• Riyadh Region (Riyadh and Al-Kharj)

• Makkah Region (Jeddah, Makkah, and Al Taif)

• Madinah Region (Al Madinah)

• Eastern Province (Dammam, Dhahran, and Al-Khobar)

Techniques with primarily a treatment goal (e.g., ARR, ASTR, SAT) can be utilized as a cost-effective wastewater treatment step in smaller communities.

Successful implementation of RQTSE ASR depends upon local supply and demand for the water. If the entire RQTSE flow is currently being reused, then ASR is not viable because there would be no water to store. Similarly, there is little value in storing RQTSE underground if there are no unmet demands for the RQTSE (i.e., the current RQTSE demands can be met in their entirety by current flows). However, water may be strategically stored now in order to meet anticipated future demands. For example, RQTSE may be stored in anticipation of a future expansion of the reuse water distribution system. The availability of a reliable RQTSE supply can be a driver for increased demand for the water.

The performance of MAR systems is highly dependent on local hydrogeological conditions. ASR and other MAR techniques require favorable hydrogeological conditions in order to meet storage and treatment goals (Section 5.3). Such favorable conditions are not present everywhere. Unfavorable hydrogeological conditions can result in the recovery of only a small percentage of stored water, deterioration in stored water quality due to adverse fluid-rock interactions, or less than targeted attenuation of contaminant concentrations. Fortunately, much has been learned over the past several decades on the extent to which hydrogeological conditions influence the performance of MAR systems, which provides valuable guidance on the selection of aquifers for MAR systems and system design.

A fundamental concern for RQTSE MAR systems is protection of groundwater resources and public health. Protection of both can be achieved in two primary ways. RQTSE can be treated to a very high degree so that it poses essentially no public health hazard even if it were to be consumed. Alternatively, an MAR system could be implemented in a carefully selected location, with respect to both the choice of aquifers and geographic site, so that there is no significant risk that the water would enter potable water supplies. Both of these strategies are being employed globally and could be used in KSA. Water quality standards for restricted and unrestricted irrigation with RQTSE have been established by MOWE. Water quality standards have not been issued specifically for groundwater recharge projects and should be established on a project-specific basis during project permitting.


5-4 STRATEGIC STUDY

RQTSE MAR systems must comply with all applicable regulations and must also receive socio-cultural (public) acceptance. In general, public acceptance of reuse is related to the potential for exposure to the water. There is typically support for projects with long distances (low potential exposure, e.g., irrigation of highway medians). Support decreases if indirect potable reuse is involved. Direct potable reuse projects typically have the least support.

5.2 MAR and ASR Concepts 5.2.1 MAR System Types MAR includes a variety of technologies to store and treat water using aquifers. The choice of system type depends upon project storage and treatment needs, and local hydrogeology.

Aquifer Storage and Recovery ASR involves the underground storage of water in aquifers using wells. ASR, using the definition of Pyne (1995), requires that injection and recovery be performed using the same well. Performing injection and recovery from a single well has the significant benefit of a lower cost than separate dedicated injection and recovery wells. Dual-function wells also have the advantage that the well pump can be used to periodically backflush the well, which is normally required in order to maintain its capacity.

In practice, most ASR systems use dual-function wells, but there are circumstances when separate injection and recovery wells may be a better solution. For example, if the body of stored water (reservoir) is moving horizontally due to local hydraulic gradients or vertically due to density stratification, then more water might be recovered using a dedicated down-gradient recovery well. The large (78-well) Las Vegas, Nevada, USA, ASR system uses both dual-purpose wells and dedicated injection wells.

ASR systems offer the following advantages for RQTSE storage:

• Much lower costs than surface storage options

• Very large storage capacities that are typically available at no cost

• Much lower land requirements than surface reservoirs

• No water losses due to evapotranspiration

• Less severe environmental impacts due to small system size

• Potential improvement in water quality through the natural attenuation of concentrations of pathogens and chemical contaminants

• Minimal adverse aesthetic (e.g., visual, odor) impacts

The main disadvantages or limitations of ASR systems include the following:

• Unfavorable hydrogeological conditions potentially resulting in low recoverability of stored water

• Adverse changes in water quality potentially occurring due to fluid-rock interactions (e.g., metals leaching)

• Adverse public and regulatory perceptions, particularly if indirect potable reuse is involved

ASR includes several different types of systems that vary in how they achieve useful storage of water (Maliva and Missimer, 2008; 2010). Useful storage refers to the degree to which


STRATEGIC STUDY 5-5

injection, storage, and recovery of water provide the system owner or operator with additional water when needed that would not otherwise be available. The two main types of ASR systems are chemically bounded and physical-storage systems.

Chemically bounded ASR systems store freshwater in an aquifer that contains poorer quality water, which is brackish water for most systems of this type. The boundary of the freshwater reservoir is the chemical contrast between the injected water and native groundwater (Figure 5-1). A mixing or transition (buffer) zone separates the injected water and native groundwater. The operation of ASR systems using brackish or saline aquifers has been described as conceptually like the inflation and deflation of a balloon (Senay, 1977), and more commonly in recent publications as like a “bubble.” Injection of freshwater inflates the balloon or bubble, which then deflates during recovery.

FIGURE 5-1 Conceptual Diagram of ASR Using Brackish Storage Zone

Note: A) Injection of freshwater displaces native brackish groundwater. Freshwater and brackish water are separated by a mixing zone. B) During recovery, freshwater is drawn back toward the ASR well.

It is recognized that neither the balloon nor the bubble metaphor is accurate for the reservoir used to store freshwater (e.g., Vacher et al., 2006; Maliva et al., 2006). The distribution of injected freshwater is controlled by aquifer heterogeneity: injected water preferentially enters the most permeable beds within the storage zone. The freshwater reservoir may also become asymmetrical in response to natural and anthropogenically influenced hydraulic gradients and density stratification.

Physical-storage ASR systems store water by increasing the total volume of water in storage in an aquifer, as manifested by an increase in aquifer water levels or heads (Figure 5-2). The function of the aquifer is similar to that of a water storage tank, in which the “walls” of the tank are the aquifer boundaries. The key technical issue is the selection of an aquifer with sufficient lateral and underlying confinement so that most of the stored water is retained (i.e., water level or head increase persists) until the time of recovery. Groundwater basins bounded by crystalline bedrock are good candidates for physical-storage ASR systems.


5-6 STRATEGIC STUDY

Physical-storage ASR systems are typically used to store freshwater in a freshwater aquifer. Another option is to store freshwater on top of brackish or saline water within a closed basin.

Aquifer Recharge Using Wells For this technology, the system is designed to increase water levels in an aquifer by injection. The prime candidates for aquifer recharge systems are aquifers where water levels or heads have significantly declined over time due to over-draft. The storage space available in depleted aquifers can be used to store RQTSE. Depending upon current groundwater use in the basin and aquifer conditions, existing production wells might be used as recharge wells. A key technical issue is how best to use this technology without degrading aquifer water quality or interfering with existing uses, particularly if the aquifer is still being used for potable water supply. Aquifer recharge systems may be operated for the benefit of all aquifer users.

Aquifer recharge using wells is very similar to physical-storage ASR in one major respect: the goal is to increase aquifer water levels. Aquifer recharge systems may also be implemented to stop or reduce the rate of water level decline from over-draft. In addition, injection and recovery may be performed using separate wells. It may be more economical to inject water at the point of supply and recover it at dedicated production wells located near the point of use. The aquifer is used to convey water from the point of supply to the point of use, rather than constructing a pipeline or canal.

Aquifer Storage, Transfer, and Recovery ASTR is a type of MAR system in which separate injection and recovery wells are used (Figure 5-3) as a means of improving stored water quality by providing additional residence time and taking advantage of the filtration provided by the aquifer (Rinck-Pfeiffer et al., 2006). The essential feature of ASTR is the intentional use of the flow of injected water through an aquifer as a treatment method. However, ASTR systems may also provide a storage benefit.

FIGURE 5-2 Conceptual Diagram of Physical Storage ASR System

Note: The increase in the volume of stored water is the product of the increased water level or head (∆h) above pre-injection levels, aquifer area, and storativity.


STRATEGIC STUDY 5-7

FIGURE 5-3 Conceptual Diagram of ASTR System

Note: Reclaimed water is injected and recovered using separate wells. Water quality is improved by physical, chemical, and biological processes as the water flows through the aquifer.

An excellent operational example of an ASTR system is the El Paso Water Utilities (Texas, USA) Hueco Bolson Recharge Project, which involves injection of highly treated RQTSE from the Fred Hervey Water Reclamation Plant into the upper Hueco Bolson Aquifer and its later recovery for potable use (National Research Council, 1994; Sheng, 2005). The recharge and recovery wells have a minimum spacing of 782 m in order to ensure an adequate aquifer residence time (2-year minimum) for complete inactivation of viruses in the recovered water.

A key technical issue is how best to accurately determine travel times between injection and recovery wells, which may be shorter than expected due to aquifer heterogeneity (e.g., the presence of flow zones with very high hydraulic conductivity). Aquifer characterization, modeling, and tracer testing can be used to assess aquifer travel times.

Salinity Barrier Systems The intrusion of saline water into aquifers is a serious concern in coastal areas that are reliant on groundwater for water supply. Groundwater withdrawals in coastal areas may reduce the potentiometric surface of aquifers to a point where the hydraulic gradient at the coast changes from seaward to landward, allowing saline waters to migrate inland (Figure 5-4). Saline-water intrusion occurs in both unconfined and confined aquifers.


5-8 STRATEGIC STUDY

FIGURE 5-4 Conceptual Diagram of Salinity Barrier System

Note: A) Saline-water intrusion occurs when groundwater pumping induces a landward hydraulic gradient at the saline-water interface B) A salinity barrier restores a seawards gradient for forming a hydraulic mound between production wells and the saline-water interface

Injection of RQTSE near the saline water/freshwater interface is a proven technology for preventing, or even reversing, saline-water intrusion and thus protecting coastal water resources. The typical salinity barrier system design includes a row of injection wells installed parallel to the coast, landward of the saline water /freshwater interface. A barrier can also be created in unconfined aquifers by land application (e.g., infiltration basin).

A prime example of a salinity barrier recharge system using highly treated wastewater is the Talbert Gap system in Orange County, California, USA (Maliva and Missimer, 2010). The Talbert Gap barrier consists of 26 multiple-zone (nested) injection wells constructed across the approximately 4-km wide gap between the Huntington Beach Mesa and the Newport Mesa. The injected water is conventionally treated wastewater that undergoes additional advanced treatment consisting of MF pretreatment followed by RO and UV light and hydrogen peroxide treatment to break down remaining organic compounds and provide disinfection. A salinity barrier system injecting wastewater that receives tertiary treatment and disinfection has been constructed at the town of Salalah in coastal Oman (Shammas, 2008).

Salinity barrier systems can also be operated to provide a storage function, with some of the recharged water recovered for non-potable use by inland wells. The use of separate injection and recovery wells would allow for improvement of water quality through natural attenuation processes (i.e., the system would also function as an ASTR system). Sheahan (1977) described a system involving paired wastewater injection and extraction proposed for


STRATEGIC STUDY 5-9

Santa Clara, California (USA). The rationale for the landward extraction well is that it would prevent degradation of fresh groundwater supplies. The extraction wells would capture injected wastewater and prevent its inland migration.

Soil-Aquifer Treatment SAT involves the infiltration of treated wastewater into shallow basins with the goal of improving its quality by vadose and saturated zone processes (Figure 5-5). SAT, as originally defined, differs from aquifer recharge by land application in that the applied treated wastewater is to be recovered and its extent in the aquifer controlled (Bouwer, 1974, 1985, 1989, 1991). In cases where the receiving aquifer contains freshwater, an integral part of the design and operation of the SAT systems is controlling the flow of recharged water in the aquifer so that it can be removed instead of migrating away and eventually contaminating wells used for drinking water (Bouwer, 1989, 1991). The same natural treatment processes are active in other types of surface applications, whether or not the recharged water is locally contained or controlled. The term soil-aquifer treatment (or SAT) has recently been used more generally in referring to surface application systems that use vadose zone transport as a natural treatment process as part of groundwater recharge systems. The wetting and drying cycles are managed in SAT systems to control redox conditions and to optimize the removal of nutrients and chemicals of concern. SAT systems may also be operated to provide seasonal and long-term storage.

FIGURE 5-5 Conceptual Diagram of SAT System

Note: Reclaimed water is recharged using infiltration basins. The quality of the water is improved by natural attenuation processes as it flows to production wells first through the vadose zone and then the phreatic zone

Bank Filtration Bank filtration is a treatment technology that takes advantage of the natural filtration that occurs as water from a surface water body travels through the bed sediment and aquifer. Bank filtration systems typically consist of either vertical or horizontal wells installed near the banks of the surface water body. Ray et al. (2002a, b) and Hubbs (2006) provide overviews of bank filtration technology. The systems are typically used as a treatment technology for river and lake water. However, the potential exists for bank filtration to be used as a treatment step for treated wastewater. Water may be recovered from lakes used for wastewater disposal and, with some additional treatment (e.g., disinfection), used for irrigation purposes.

5.2.2 System Performance Criteria The performance of MAR systems should be evaluated using quantitative criteria based on the specific storage and treatment objectives of the each system. Ideally, target performance criteria for an MAR system should be established at the start of a project. Chemically bounded ASR systems are usually evaluated in terms of recovery efficiency (RE), which is defined as the percentage of the injected water (Vinj) that is recovered (Vrec) at a quality suitable for its intended use.



RE(%) = 100(Vrec /Vinj)

RE can be calculated over the entire operational history of a system (system recovery efficiency [SRE]) or over an individual operational cycle (operational recovery efficiency [ORE]) (Sheng et al., 2007). ORE tends to improve over time as native groundwater is flushed from the vicinity of ASR wells and a buffer zone is developed. ORE values are thus normally greater than SRE values.

For ASR systems using brackish-water aquifers as storage zones, salinity criteria (e.g., total dissolved solids [TDS], chloride) are normally used to calculate RE. From a practical, operational perspective, the RE of ASR systems is a function of the intended use of the recovered water and its sensitivity to variations in water quality. Water use for irrigation purposes can usually be of lesser quality than water intended for potable use. The current (2006) MOWE reuse standard for TDS is 2,500 mg/L, whereas the Saudi drinking water standard is 1,500 mg/L.

Hence, an ASR system storing RQTSE for irrigation purposes can have a greater RE than an identical system storing water for potable use because of the greater flexibility in the use of more saline water for irrigation. In systems using brackish-water storage zones, salinity gradually increases toward the end of a recovery period. Recovery may continue at higher salinities for systems storing water for irrigation purposes than for systems used for potable supply.

Physical-storage and aquifer recharge systems must be evaluated by different criteria than those used for chemically bounded ASR systems. The objective of these systems is to increase the volume of water in storage in an aquifer. Therefore, performance of these systems must be based upon storage rather than water quality criteria. The performance criteria should also have a time component, since the critical issue is the availability of additional water at the time of need (end of storage period).

The evaluation of system storage efficiency (SE) is similar to that of RE, based on the ratio of the increase in the volume of water in storage in an aquifer (∆Vs) to the volume injected.

SE(%) = 100(∆Vs /Vinj)

The change in the volume of water stored in an aquifer can be estimated from the change in head (∆h), storativity (S), and aquifer area (A).

∆Vs = ∆hSA

In practice, evaluating the performance of physical-storage and aquifer recharge systems is much more complicated because aquifer heads vary across an aquifer and are affected by processes other than recharge, particularly extractions by other aquifer users. Groundwater modeling is, therefore, generally necessary to evaluate aquifer-wide changes in storage in response to recharge.

Other types of MAR systems are evaluated using other criteria. Salinity barrier systems, for example, are evaluated based on their effectiveness in preventing or reversing saline-water intrusion, using salinity data from monitoring wells. SAT and ASTR systems are evaluated based on the degree to which the recovered water meets targeted water quality criteria. For example, if pathogens are the primary concern, then system performance might be evaluated based on whether or not the recovered water meets the MOWE RQTSE irrigation standards for fecal coliform bacteria and intestinal nematode eggs, or other criteria based on local health information.

It is very important to have realistic expectations concerning likely MAR system performance. Normally, some water will not be recoverable and long-term operational REs for an ASR system will be less than 100 percent. A more realistic target for a properly performing MAR system is an RE of 70 to 80 percent. Economic evaluations of MAR



systems should consider the expected amount of unrecoverable water, in the same manner as evaluations of surface reservoirs need to consider losses to evaporation.

5.2.3 KSA MAR General Opportunities KSA has a diverse hydrogeology, and there is a wide variety of potential applications of MAR technologies. Area-specific potential MAR applications for the main population areas are discussed in Sections 5.7 through 5.10. The design and operation of systems can and should be tailored to local hydrogeological conditions and aquifer uses.

A major challenge is how to avoid unplanned potable reuse and impacting aquifers considered by their users to be pristine. The over-riding concern with RQTSE MAR is avoiding public health impacts associated with the water entering the potable supply. Indirect potable reuse might occur from MAR systems that use brackish-water aquifers that are too saline for direct consumption, but are being used as a source of water for blending with desalinated water. Recharge of RQTSE into aquifers that have a non-potable use may still arouse opposition from local users if they have not been convinced of the benefits of the project through public outreach.

Over-drafted sedimentary rock aquifers in the central and eastern part of the Kingdom have storage space that could be used for RQTSE storage. As aquifers have diminishing value as water sources due to depletion or degradation of water quality, officials could decide that the optimal future use of these aquifers is for the storage of high-quality RQTSE. The ASR systems could serve a dual purpose of storing high-quality RQTSE (and thus improving the quality of water available to local users) and restoring aquifer water levels.

RQTSE may be stored in aquifers that can contain brackish groundwater and, as a result, are not suitable for potable use without treatment (desalination). RQTSE would be injected and recovered using dual-function ASR wells. The main technical issue is identifying a storage aquifer with hydraulic properties and water quality that would allow for the operation of a system at high REs. Groundwater flows in the carbonate aquifers of KSA tend to be dominated by secondary porosity (fractures and/or karstic solution conduits), typically resulting in poor REs (Section 5.3.1). Although sandstone aquifers may have preferable hydraulic properties, they are generally considered primary potable water supply sources in the Kingdom. Conventional ASR may be successful in aquifers that contain mildly brackish water that can accommodate a greater amount of mixing of recharge and native groundwater.

Aquifers underlying ephemeral river channels (wadis) have hydrogeological characteristics that are well suited for ASTR. The aquifers are usually well confined (particularly in crystalline bedrock terranes) and are elongated in the direction of flow. Wadi aquifers generally have relatively steep hydraulic gradients, which are usually not favorable for ASR because the advective movement of stored freshwater is undesirable. In the case of ASTR, it is possible to take advantage of the downstream hydraulic gradient and good underlying and lateral confinement to control the movement of the recharged water. Water could be injected using upstream wells and recovered using downstream wells (Figure 5-6). Alternatively, wadi aquifers could be used for ARR (SAT), in which recharge is performed using upstream basins, trenches, or galleries. MAR systems could be located far enough downstream in wadi alluvial aquifers so that they would not impact upstream wells that are still used for freshwater supply.



FIGURE 5-6 Conceptual Diagram of Wadi ASTR System Note: Water is injected in upstream wells and recovered using downstream production wells. Alternatively, reclaimed water may be recharged upstream into the vadose zone, in which case the system would be an ARR or SAT system

Saline-water intrusion has been documented in areas of intense groundwater use along both the east and west coasts of KSA. Anthropogenic saline-water intrusion occurs in both Tertiary-aged limestone aquifers (Dammam Aquifer) and in some wadi alluvial aquifers. Opportunities thus exist for the development of salinity barrier systems to both protect and enhance local groundwater supplies.

5.3 MAR and ASR Feasibility Issues The performance of ASR and other types of MAR systems depends upon local hydrogeology, which may not be favorable. The operational history of existing systems and the results of theoretical studies provide many insights into the hydrogeological conditions that are needed for the successful implementation of ASR and MAR systems, which were reviewed by Maliva and Missimer (2010). The feasibility of MAR projects in general depends upon three classes of factors:

• Aquifer hydraulics and water quality, which control the storage, movement, and mixing of recharged water

• Geochemistry, which includes chemical and biological reactions in the storage zone that can result in either an improvement or deterioration of stored water quality and can impact system performance through aquifer and well clogging

• Regulatory and socio-cultural factors, which can determine whether a project will be allowed to move forward

5.3.1 Aquifer Hydraulics and Water Quality The importance of aquifer hydraulics and water quality on the performance of MAR systems depends upon their specific storage and water treatment objectives. The hydrogeological controls over the performance of ASR systems that store freshwater in brackish and saline aquifers have received much study, including recent reviews by Brown (2005), Maliva et al. (2006), Reese and Alvarez-Zarikian (2007), and Maliva and Missimer (2010). The primary factors controlling system performance are native groundwater salinity and aquifer heterogeneity, which in turn controls aquifer dispersivity.

Salinity affects ASR system performance in two important ways. First, as the native groundwater salinity increases, system performance becomes increasingly sensitive to the mixing of native groundwater and stored water. Even a small amount of high-salinity native groundwater can cause the salinity of the stored water to increase to unacceptable levels. On the contrary, where native groundwater is mildly brackish (i.e., there is a small difference



in water quality between native groundwater and stored water), systems can tolerate much more mixing and aquifer hydraulic conditions can therefore be less than ideal.

Second, salinity impacts the performance of ASR systems through density-driven fluid migration (free convection or buoyancy stratification). Freshwater injected into an aquifer containing brackish or saline water tends to migrate upward and outward in the storage zone, while saline water tends to migrate toward ASR wells along the bottom of the aquifer (Figure 5-7). Buoyancy stratification tends to result in lower REs as saline water more quickly reaches ASR wells along the bottom of the aquifer. The rate of buoyancy stratification is primarily a function of the salinity (density) differential between the native groundwater and stored water, the vertical hydraulic conductivity of the storage zone, and the duration of storage.

FIGURE 5-7 Conceptual Diagram of Density-driven Movement of Freshwater Injected into Saline Water (i.e., buoyancy stratification) in ASR System

Note: The more buoyant freshwater tends to move upward and outward toward the top of the storage zone. Saline water migrates toward the ASR well along the bottom of the storage zone.

The effects of groundwater salinity on ASR system performance can be evaluated through density-dependent groundwater modeling. There is no single salinity threshold for adverse impacts on ASR system performance. Nevertheless, as a generalization, moderate (TDS < 5,000 mg/L) native ground salinities are preferred, and low REs would be expected for salinities in excess of 10,000 mg/L.

High degrees of aquifer heterogeneity can have very adverse impacts on the performance of MAR systems in which the goal is to recover and/or treat a specific volume of water. Sensitive MAR systems include chemically bounded (brackish and saline water) ASR systems, salinity barriers, ASTR, and ARR (SAT) systems. The ideal hydrogeological condition is for groundwater flow to be dominated by matrix (intergranular or intercrystalline) flow rather than flow through large secondary pores such as fractures and karstic solution conduits (Figure 5-8). A review of ASR systems in Florida (USA) revealed that failed systems invariably had groundwater flow dominated by secondary porosity (Maliva and Missimer, 2010).



FIGURE 5-8 Conceptual Diagram of Matrix-dominated versus Conduit Flow Note: In matrix-dominated flow, the injected water (shaded blue) flows in the intergranular pores between the sand grains. In conduit flow, the injected water flows predominantly through secondary pores such as karstic dissolution features or fractures

The concentration of flow into secondary pores that constitute a small percentage of the aquifer volume adversely impacts RE in several ways. For example, the high hydraulic conductivity of secondary pore systems results in rapid flow under prevailing aquifer hydraulic gradients. The injected water volume in secondary porosity systems also has a much greater areal extent.

Secondary porosity (e.g., fracture) systems tend to have much higher degrees of dispersive mixing than matrix-dominated systems because of both greater flow velocities and more irregular pore geometries (Domenico and Schwartz, 1998). Additionally, large concentration gradients may be present between the fractures and adjacent matrix blocks, which can lead to relatively high diffusion rates. Native groundwater present in the matrix “bleeds” into water stored in secondary pores.

Secondary porosity can also adversely impact MAR systems that have primarily a treatment objective. For example, the presence of high-transmissivity flow zones in ASTR systems can result in very rapid flow between the injection and recovery well and, therefore, low degrees of contaminant attenuation. The presence of low vertical hydraulic layers in SAT systems can impede vertical flow.

Other hydraulic factors that can impact the RE of ASR systems using brackish-water storage zones are storage-zone transmissivity, effective porosity, aquifer thickness, and regional hydraulic gradient. The latter is important because large gradients can result in the rapid movement of stored water.

Alluvial aquifers, such as wadi aquifers, are typically dominated by intergranular (matrix) flow, although underlying fractured and weathered bedrock may also contribute water. Groundwater flow in the Jurassic through Tertiary limestone aquifers of KSA is dominated by secondary porosity (Sections 5.7 and 5.10), making them generally unfavorable for high REs in ASR systems. However, systems may still be feasible if they have a relatively low sensitivity to mixing. For example, systems storing RQTSE in aquifers containing less than 5,000 mg/L of TDS may still be feasible if the recovered water is to be used for irrigation.

Preferred Hydrogeological Conditions

• TDS < 5,000 mg/L

• Groundwater flow to be dominated by matrix (intergranular or intercrystalline) flow

• A combination of detailed aquifer characterization and groundwater modeling can be used to assess potential system performance and the likelihood of system success.



An important lesson of the MAR experience to date is the importance of local aquifer characterization as part of the feasibility study for MAR projects (Maliva and Missimer, 2010). A combination of detailed aquifer characterization and groundwater modeling can be used to assess potential system performance and the likelihood of system success. Unfavorable hydrogeological conditions may be identified early in a project. Decision-makers then have the opportunity to investigate other storage zones, project sites, or system options rather than prematurely committing to the cost of full-scale project construction. Favorable aquifer characterization and modeling results may lead to greater confidence in the success of the project.

5.3.2 Geochemistry Geochemical incompatibility of recharged water with aquifer minerals and native groundwater can adversely impact system performance by causing clogging or deterioration of the quality of the stored water. Chemical clogging is a reduction in well performance due to the precipitation of a mineral cement on the well screen or borehole wall, or by cementation and mineral alteration within the aquifer near the borehole.

Calcium carbonate (calcite) is the most common scalant. Water chemistry data from the Riyadh centralized WTPs (Al-Jasser, 2011) indicate that calcium carbonate scaling should not be a concern as the RQTSE is undersaturated with respect to calcite. The chemistry of RQTSE would be expected to vary across the Kingdom, and the Riyadh data may not be representative of other regions. Nevertheless, the potential for calcium carbonate scaling can be easily determined from basic chemical data, and scaling can readily be prevented, if necessary, through acid addition for pH adjustment.

RQTSE tends to have high DO concentrations, whereas aquifers are often chemical reducing. The introduction of DO can cause redox reactions such as the oxidation of chemical reducing minerals (e.g., sulfides, iron carbonates, and glauconite) and the precipitation of iron oxyhydroxides. Reduced iron is present at low concentrations in natural groundwaters (as dissolved ferrous iron, Fe2+) and in reactive minerals in aquifers (iron sulfides), so the precipitation of iron oxyhydroxides would normally not be a significant clogging mechanism. However, iron bacteria (which oxidize iron) form biofilms that are a common cause of biological clogging of wells.

Oxidation of reduced minerals can release trace elements that can adversely impact the quality of stored water. Iron sulfide minerals (pyrite) contain a variety of trace elements, such as arsenic and molybdenum, which are released upon their oxidative dissolution. The leaching of arsenic into water stored in ASR systems is a major concern in some areas such as south Florida, USA (Arthur et al., 2001, 2002; Mirecki, 2006a, 2006b). Arsenic concentrations in water stored in ASR systems increased to levels that exceeded the applicable groundwater standard, which is the primary drinking water standard. The regulatory impact of arsenic leaching greatly increased after the drinking water standard (and thus the groundwater standard) for arsenic was lowered in the United States from 50 to 10 micrograms per liter (μg/L). Many more ASR systems are now in violation of groundwater standards because they have reported maximum concentrations in the 11- to 50-μg/L range, which previously were not a violation.

Significant leaching of arsenic and metals has not occurred in all ASR systems. Its occurrence appears to be restricted to areas where aquifer rock contains trace quantities of iron-bearing sulfide minerals. The low concentrations of leached arsenic generally do not prevent use of the recovered water. Arsenic concentrations may be reduced through blending. The reported maximum arsenic concentrations in the United States were mostly below the KSA irrigation standard of 100 μg/L (0.1 mg/L).

The introduction of DO in some ASR system using siliciclastic (e.g., sand and sandstone) aquifers has resulted in elevated iron and manganese concentrations in stored water.



Elevated iron and manganese concentrations have been documented in ASR systems in the eastern Coastal Plain of the United States in which marine sandstones were used as storage zones. The source of the iron and manganese is reduced minerals such as iron sulfides and carbonates.

Injection of freshwater into siliciclastic aquifers that contain brackish or saline water may also cause swelling and dispersion of clays, which can cause a rapid reduction in permeability. Aquifers susceptible to salinity-induced permeability changes are referred to as being “water sensitive.” Some clay minerals, such as montmorillonites, expand or swell when water penetrates and is adsorbed in the interlayer molecular spaces. Clay dispersion involves the mobilization of very fine clay particles, which flow with the injected water until they become lodged in and clog pore throats.

Reactive mineral phases tend to be primarily authigenic minerals (i.e., minerals that form within the sediments or rocks, such as cements) rather than the framework grains of the aquifer rock and sediments (e.g., quartz, feldspar, rock fragment grains, and carbonate grains and matrixes). The sediment and rock types present in KSA aquifers that might be used for MAR systems (limestones, quartz arenites, and alluvial sediments) are usually associated with relatively low reactivities. The main exception is residual evaporite minerals (gypsum and anhydrite), which are susceptible to dissolution. Nevertheless, a geochemical compatibility analysis is an integral part of the development of MAR projects. The potential for dissolution, precipitation, and alteration reactions can be assessed using data on injected (source) water and native groundwater chemistry and aquifer mineralogy using mineral equilibrium and speciation software packages such as PHREEQC (Parkhurst and Appelo, 1999).

5.3.3 Regulatory and Socio-Cultural Issues MAR projects must meet all pertinent regulatory requirements. In the absence of specific regulations pertaining to aquifer recharge, projects are typically evaluated through well permitting and environmental impact assessment processes. KSA currently does not have regulations specific to MAR projects. MAR projects in the Kingdom must be permitted by MOWE, and it is therefore important to obtain MOWE input very early during project development.

Public support is important for the successful implementation of MAR and is particularly critical for projects involving RQTSE. Successful implementation of wastewater reuse technologies requires an understanding of the social environment in which they are to be applied (Lazarova et al., 2000), including cultural and religious values, teachings, and doctrines. The Council of Leading Islamic Scholars in KSA issued a fatwa in 1978 stating that RQTSE can be used for ablution and drinking if it is sufficiently and appropriately treated to ensure good health:

Public Support

The successful implementation of MAR is dependent on public understanding of and confidence in water resources management involving RQTSE.



According to the report set by the experts in this regards, a large body of water would be pure from any impurity if such impurity is removed, if more water added to it, or if such impurity is eliminated by the passing of time, the sun, the wind or any other cause that would remove its impurity. Impure water could be purified by the modern filtering techniques that are the best and most efficient methods for purification, in which many materials will be added to remove impurities and certified by the water treatment experts. Therefore, this Council believes that such water will be totally pure and it may be used for ritual purification and drinking as long as there are no negative consequences on health. If drinking is to be avoided, it is merely for reasons of public health and safety, not due to any ramifications of Islamic Law.

The reuse of treated wastewater is not contrary to Islamic law, but its potable use is not recommended because of negative public sentiment. Asano and Cotruvo (2004) noted that “The irony is that water derived from ‘natural’ but obviously imperfect sources often receives only basic treatment (filtration and disinfection). The final product might not be as high quality as the reclaimed wastewater that has been subject to much more rigorous treatment, water quality control, and management.” The “Law of Contagion” may apply, which suggests that once water has been in contact with contaminants, it can be psychologically very difficult for people to accept that it has been purified, and this may apply (Khan and Gerrard, 2006). A similar point, noted by Daughton (2004), is that the more remote the hydrologic connection, the easier it is for the public to accept water reuse.

On projects where the RQTSE is being put to a non-potable use and the storage aquifer is not used for potable supply, public attention and opposition tend to be limited. However, MAR projects involving planned or potentially involving unplanned indirect potable reuse are likely to arouse public opposition and require much greater public outreach and education to gain confidence in and support for the project. An additional consideration is that MAR may reduce the stigma associated with reuse of RQTSE. Public confidence in water recycling projects is increased when the RQTSE is put back into the natural systems, such as rivers and aquifers, before recovery for reuse (Al-Otaibi and Mukhopadhyay, 2005; Dillon et al., 2006a, 2006b). In the case of ASTR, the public may perceive little connection between upstream injection wells and downstream recovery wells. In general, the type of system to be used can affect public perceptions.

5.4 Water Quality Issues Associated with MAR of RQTSE 5.4.1 Introduction A critical issue for RQTSE reuse and MAR projects is ensuring that public health and the environment are not endangered. With respect to MAR systems, the primary concern is avoiding the introduction of pathogens and chemical contaminants into the potable water supply. An additional concern is to avoid impairing groundwater so that it remains acceptable for local irrigation use. MAR can also provide important water quality benefits. It is now well documented through operational and experimental results that MAR systems can be effective in reducing the concentrations of pathogens and many chemical contaminants in RQTSE (Dillon et al., 1999, 2006; Pyne, 2002; Khan and Rorije, 2002; Stuyfzand, 2007; Dillon and Toze, 2005; McQuarrie and Carlson, 2003, Pavelic et al., 2006). MAR can be used as a treatment element in a multiple barrier approach to wastewater treatment (referred to as “natural aquifer treatment”).

The risks associated with MAR using RQTSE depend upon the following main factors:

• Quality of the recharged RQTSE (concentrations of contaminants of concern)



• Local hydrogeology and geographic location of the system, which control the potential for unintended exposure (i.e., recharged water entering a potable water supply well or unplanned entry into an irrigation well)

• Contamination attenuation processes that occur during RQTSE recharge, storage, and travel through storage aquifer

• Use of recovered water, including any post-recovery treatment

5.4.2 Health Risks Associated with RQTSE RQTSE may contain a variety of microbiological and chemical contaminants. The contaminants of greatest concern are pathogenic microorganisms because a one-time exposure can cause serious illness (Pescod, 1992; Toze, 2004, 2005). Chemical contaminants, on the other hand, are typically present in wastewater at low concentrations and long-term exposure is usually necessary for an adverse health impact to occur.

A wide variety of protozoa, helminths, trematodes, bacteria, and viruses have been identified as infectious agents in untreated municipal wastewater. The microorganisms associated with waterborne disease are primarily enteric pathogens (i.e., they originate within the intestines of humans or other animals), which have a fecal-oral or fecal-dermal route of infection (either human-to-human or animal-to-human) and can survive in water (National Research Council, 1998). The infectious agents present in wastewater and their concentrations depend upon the sources of the wastewater, the general health of the population in the service (collection) area, the existence of “disease carriers” in the population, and the ability of the various infectious agents to survive in environments outside their host (National Research Council, 1994). Risks from microbial contamination depend not only on the dose of microorganisms, but also on the host’s immune status. Sensitive populations, including children, the elderly, and people with compromised immune systems, stand a greater risk of severe outcomes (National Research Council, 1998). Sensitive populations also include people who lack immunity to locally endemic waterborne diseases (e.g., tourists).

Virtually any chemical generated or used in the service area of a WWTP could potentially enter the RQTSE supply. The National Research Council (1998) recognized three categories of chemical contaminants that are present in RQTSE:

• Inorganic chemicals (iron, manganese, boron, etc.) and natural organic matter that are naturally present in the water supply

• Chemicals used or created by industrial, commercial, and other human activities (personal care products, pharmaceuticals, etc.) in the wastewater service area

• Chemicals added or generated during water and wastewater treatment and distribution processes (e.g., disinfection byproducts [DBPs])

The second group of chemical contaminants includes compounds of emerging concern (CECs), which are chemicals that are currently not regulated (i.e., there are no drinking water or wastewater standards), but may have potentially deleterious human health or ecotoxicological effects. CECs encompass a wide variety of organic compounds that include pharmaceuticals (prescription and non-prescription drugs and their breakdown products), antibiotics, synthetic and natural hormones, personal care products, and detergent metabolites. CECs are currently receiving a great deal of attention because they have been detected at very low concentrations in what were considered to be clean surface water bodies and in the drinking water supply for some major cities. The presence of CECs in groundwater, surface water, and RQTSE is not a new phenomenon; rather, previous analytical technologies were unable to detect these compounds at extremely low concentrations: nanograms (10-9 g) per liter (parts per trillion) (Sedlak et al., 2000).



CEC residuals are found at concentrations orders of magnitude below the concentrations at which an effective therapeutic dose would result from ingesting the water (Ongerth and Khan, 2004). The major human health concern with emerging contaminants is not acute effects from one-time exposure, but rather potential chronic effects from long-term exposure to very low doses (Drewes et al., 2003). However, there is no evidence that CECs at the concentrations detected in drinking water pose a significant health risk.

Although it is widely accepted that the presence of CECs in the environment and water supply is undesirable, there is much uncertainty about appropriate responses. It is recognized that CECs should be viewed in a proper context relative to other environmental risks. Daughton (2009) noted the importance of determining where CECs fall within the growing list of overarching environmental issues in a world of diminishing resources and continuing emerging new concerns. On a global basis, the potential risks of CECs, as they are now understood, appear to be greatly outweighed by the benefits of RQTSE reuse in addressing the problems associated with water and food scarcity.

5.4.3 Assessment of Health Risks Associated with RQTSE MAR The Australian Guidelines for Water Recycling (NRMMC-EPHC-AHMC, 2006; 2009) provide an excellent overview of risk assessments for RQTSE reuse (recycling) and MAR systems. The guidelines are not mandatory and have no formal legal status, but are designed to provide guidance for individual states in developing their reuse and MAR policies and regulations. A distinction is made between hazard and risks. Hazards are associated with biological, chemical, physical, or radiological agents that have the potential to cause harm to people, animals, crops, or the environment. Risk is the likelihood of identified hazards causing harm and is the product of likelihood and harm (NRMMC-EPHC-AHMC, 2006). Maximal (unmitigated) risk is the risk in the absence of preventive or mitigative measures. Residual risk is the risk after existing and proposed preventive and mitigative measures.

A risk assessment is defined broadly as the process of estimating the probability of occurrence of an event and the probable magnitude of adverse effects on safety, health, and ecology over a specified time period (Asano et al., 2007). Risk assessment has four main components:

• Hazard identification, which is the recognition of biological, chemical, physical, or radiological agents that increase the incidence of a health condition.

• Exposure assessment, which is the evaluation of exposure scenarios and the probability (and frequency) of exposure of an individual to biological, chemical, physical, or radiological dose over a specified time period

• Dose-response assessment, which quantifies the risk of disease or infection of an individual from a given biological, chemical, physical, or radiological dose

• Risk characterization, which combines the exposure and dose-response assessments to estimate the incidence of a given adverse impact on a population

Two types of risk assessments are performed under the NRMMC-EPHC–NHMRC (2009) MAR guidelines. First is a “maximal” risk assessment, which identifies inherent risks in the absence of preventive and mitigative measures. An initial exposure assessment is part of the maximal risk assessment, which considers the transport of RQTSE in the subsurface and possible pathways for human and environmental exposures. The second type, the residual risk assessment, evaluates risks that remain after the consideration of potential preventive and mitigative measures. For example, a maximal risk assessment of an/RQTSE ASR system would likely identify pathogens in the recovered water as a significant risk. The residual risk assessment might consider risks remaining after natural attenuation during the planned storage period and post-treatment of the recovered water, such as disinfection. The



application of the guidelines to a trial ASTR project is discussed by Page et al. (2010a, b). The phasing of the Australian MAR guidelines coincides with the normal MAR project phasing: a desktop study, followed by field testing, and then construction and testing of a pilot system.

5.4.4 Pathogenic Attenuation in Aquifers Microbial survival in a groundwater environment is influenced by a variety of factors, including the type of organism, temperature, DO concentration, redox state, water chemistry, water source, and the population of indigenous groundwater organisms. Enteric microorganisms enter a very different geochemical environment than their intestinal source; this geochemical environment is already inhabited by native groundwater microorganisms, which leads to greater inactivation (die-off or removal) rates (John and Rose, 2005). Rates of inactivation are commonly expressed in terms of log10 removals (or simply log removals), calculated as follows.

𝑙𝑜𝑔10 𝑟𝑒𝑚𝑜𝑣𝑎𝑙𝑠 = −𝑙𝑜𝑔 �𝑐𝑓𝑐𝑖�

Where,

Ci = initial number of organisms

Cf = final number of organisms at day “t”

A log10 removal time is the time required for a 90 percent reduction in the number (or concentration) of microorganisms. A 2-log10 removal time is the time required for a 99 percent reduction in number of microorganisms.

John et al. (2004), John and Rose (2005), and Toze (2005) summarized the current state of knowledge for the inactivation of many microorganisms of concern in groundwater. Most of the studied pathogenic microorganisms have log10 removal times from 1 to 50 days, which corresponds to more than 7 log (99.99999 percent) removal over a period of 1 year. Internal parasites are more resistant to inactivation under some circumstances, with over 200 days for a 2-log reduction of Giardia cysts reported in some experiments (John et al., 2004). John et al. (2004), however, noted that occasionally large variability in inactivation rates has been observed for Giardia cysts between trials run under the same conditions. The authors therefore urged caution in interpreting the results of their study for evaluation of microorganism survival in the groundwater environment, because similarly larger degrees of variation might occur under natural conditions.

The relatively rapid inactivation rates of most enteric microorganisms in the groundwater environment indicate that MAR can be an effective means for improving the quality of (“polishing”) RQTSE. The RQTSE produced by modern WWTPs is often of high quality, but may still not meet standards for uses involving potential human exposure. For example, Al-Jasser (2011) reported that the effluent from the six largest WWTPs in Riyadh exceed the maximum allowable average fecal coliform contaminant level (2.2 most probable number, MPN/100 mL) for unrestricted irrigation, with average concentrations of 25 to 258 MPN/100 mL. The 1.1- to 2.2-log10 removal needed to meet the unrestricted irrigation contaminant level could be met by 3 to 70 days of subsurface storage in an MAR system using published values for the inactivation rates for E. coli bacteria.

Toze (2006) cautioned that the current understanding of how environmental factors influence pathogen survival is incomplete, and that accurately predicting the stability of various pathogens in different environments is still difficult. The NRMMC-EPHC–NHMRC (2009) strongly recommended direct testing of pathogen decay rates at MAR sites. In situ diffusion chambers have been used to determine log10 reduction in pathogen numbers for MAR research sites (e.g., Page et al., 2010b, Toze et al., 2010), but are too complex and costly to



be a routine tool for most MAR projects. In the absence of site-specific pathogen decay data, conservatively long values obtained from the scientific literature could be used, particularly if data are available from geochemically similar systems.

5.4.5 Chemical Contaminant Attenuation in MAR Systems The concentrations of chemical contaminants in wastewater may be reduced by a variety of processes, including sorption, precipitation, and biological degradation as the water passes through the soil (vadose zone) and/or aquifer. The reduction in concentrations may be particularly effective if the recharged water passes through different redox environments, each of which may include the removal of different compounds (Dillon et al., 2006; Stuyfzand, 2007). The placement of RQTSE into storage in natural groundwater environments also increases the recycling time and thereby allows more time for biodegradation of contaminants that degrade more slowly (Dillon et al., 2006).

There has been much research on the effectiveness of SAT for the improvement of RQTSE quality. It was recognized in the earliest SAT research (e.g., Bouwer,1974; Bouwer et al., 1980) that SAT is effective in reducing the concentration of dissolved organic carbon (DOC) in wastewater. A study of the fate of wastewater effluent organic matter (EfOM) and trace organic compounds at operational SAT sites in Mesa and Tucson, Arizona, USA, indicated that 50 to 70 percent of the DOC is removed after accounting for dilution (Fox et al., 2001; Drewes et al., 2003b; Amy and Drewes, 2007). The character of the bulk organics present after long-term SAT resembles the character of natural organic matter (NOM) present in drinking water. A “naturalization” of organic matter occurs that results in its character becoming very similar to the NOM present in surface water and groundwater not affected by recycled water (Drewes, 2009).

However, some CECs are persistent in groundwater environments and thus water treated by SAT. Column experiments by Rauch et al. (2005) demonstrated that soil organic matter content and composition affect organic micropollutant removal. Different organic matter substrates promoted the establishment of different soil microbial community compositions and/or concentrations, which affected the removal of different micropollutants. The study also demonstrated that microbial adaptation to micropollutants occurred as removal rates increased, with increased exposure of the columns to trace pollutants.

There is an increasing body of evidence indicating that chemical contaminant concentrations decrease in MAR systems that involve subsurface injection (e.g., ASR and ASTR). There has been considerable study of the fate of DBPs in ASR systems used to store potable water. Experimental and field studies have shown that the biotransformation rate of trihalomethanes (THMs) and haloacetic acids (HAAs) is dependent upon the redox environment (Bouwer and Wright, 1988). In general, as the groundwater environment becomes more oxidizing, more compounds tend to persist (Singer et al., 1993, Landmeyer et al., 2000; Nicholson et al., 2002; Fram et al., 2003). HAAs undergo biodegradation under both oxic and anoxic conditions, whereas THMs are resistant to biodegradation under oxic conditions. Chlorinated THMs required the most reducing conditions for significant biodegradation.

Field and experimental studies have demonstrated that the concentrations of some CECs decrease in a groundwater environment, through biodegradation and adsorption, whereas other compounds are much more resistant (e.g., Khan and Rorije, 2002; Drewes et al., 2003; Heberer et al., 2004, Snyder, et al., 2004, Ying et al., 2004, Zuehlke, et al., 2004, Stuyfzand, 2007). As with SAT, anti-epileptic drugs (e.g., carbamazepine, primidone) were not removed during recharge under either oxic or anoxic conditions.

SAT systems can also remove nitrogen compounds, by the alternation of nitrification under aerobic conditions, and denitrification under anaerobic conditions. The form and concentration of nitrogen compounds of water passing through SAT systems depend upon



the hydraulic loading rates and flooding and drying schedule for the infiltration basins (Bouwer, 1974, 1985, 1991; Pescod, 1992).

MAR of RQTSE can result in an improvement in water quality through the attenuation of chemical contaminants. However, some chemical contaminants are persistent in groundwater environments.

5.4.6 Treatment Strategies Three main treatment strategies have been applied with respect to RQTSE MAR, which vary depending upon the degree of wastewater treatment and the reliance on natural aquifer treatment processes. The mostly commonly used strategy to date for systems using injection wells is to store tertiary-treated RQTSE in aquifers that are, at least locally, not used for potable water supply. Tertiary treatment, which typically involves an additional filtration step plus disinfection beyond secondary treatment, is used to reduce the concentration of suspended solids and pathogens. Isolation from potable water supplies is achieved through the use of aquifers that contain non-potable quality water (e.g., brackish water) and the presence of vertical confinement and/or geographic separation from potable water production zones. Improvement in stored water quality during storage is incidental.

Secondary- and tertiary-treated RQTSE is also commonly used for MAR systems that are intended primarily to provide treatment of the RQTSE, with SAT systems being the most common example. Secondary-treated wastewater is usually recharged in SAT systems. ASTR systems require tertiary-treated water in order to avoid well clogging. Potable water supplies are protected by physical isolation of the RQTSE (e.g., use of non-potable aquifers, geographic separation, and hydraulic control over the recharged water volume).

Very high levels of treatment have been used in systems where the possibility of indirect potable reuse exists (i.e., the RQTSE may enter the potable water supply). The best example of a “hyper-treatment” system is the Orange County, California (USA), Groundwater Replenishment System (GWR), which consists, beyond conventional wastewater treatment, of microfiltration (MF) followed by RO and ultraviolet (UV) light and hydrogen peroxide treatment to break down remaining organic compounds through an accelerated decomposition (oxidation) process (Markus, 2009). The GWR system produces water with quality far higher than that of many potable water systems.

Such high levels of treatment come at a great cost and are not necessary or economically viable for most wastewater reuse and MAR applications. As with wastewater reuse in general, treatment standards for wastewater use for MAR must consider local socioeconomic conditions. Even if drinking water augmentation is not explicitly foreseen in an MAR project, drinking water quality standards are still commonly applied to the recharged or recovered water in many applications in developed countries (Wintgens et al., 2008). The primary benefit of such high-level treatment is to provide peace of mind to the public, which can be a critical factor in securing public acceptance of reuse projects.

Intermediate treatment options may be more economical than upgrading an entire wastewater treatment facility. For example, where RQTSE does not meet standards for unrestricted irrigation, only the flow that is needed for unrestricted irrigation or other uses requiring higher quality water could receive additional treatment, such as additional disinfection. The additional treatment could be provided either at the WWTP or point of use. The RQTSE recharged at an ASR system in Hillsborough County, Florida, USA, for example, received additional UV disinfection at the system site to ensure that it met applicable microbiological groundwater standards prior to injection.

For systems where the RQTSE receives tertiary treatment or less, the critical technical issue is avoiding indirect potable reuse. Potable reuse in KSA could potentially occur through recharge into brackish-water aquifers that are used for blending with desalinated water. An



important element of feasibility assessments and project design is selecting project sites where potable reuse will not occur. This can be achieved by either selecting a storage aquifer that is not locally used for potable supply, using geographic separation of the MAR system from potable-water supply wells, or locating the MAR system downgradient from potable-water supply wells. Groundwater modeling is an integral tool for evaluating the transport of RQTSE recharged into MAR systems.

5.5 Economic and Operational Issues The technical feasibility of MAR projects depends upon favorable hydrogeological conditions. The economic feasibility of MAR projects depends upon a number of design, logistical, and operational issues. Ideally, the costs to construct and operate MAR systems should not exceed the value of the recovered stored or treated water. However, as with water projects in general, MAR projects may have secondary and social benefits that are difficult to quantify. For example, one benefit of reusing wastewater is avoidance of the environmental impacts associated with its disposal. Economic and operational issues need to be considered in a feasibility assessment and the selection, design, and location of MAR systems.

The costs of ASR systems include both capital and O&M costs. Major capital cost items include the wells and pumps, wellhead, piping, instrumentation, electrical supply connection, land acquisition, and engineering and regulatory costs. Major O&M costs include electrical supply, monitoring and reporting, well rehabilitation, maintenance and replacement of equipment, and project staff compensation and overhead. Actual capital and O&M costs are highly project-specific.

MAR project costs are typically evaluated in the same manner as costs on other engineering projects by using some type of net present value (NPV), present worth (PW), or life cycle cost (LCC) analysis, which considers both amortized capital costs and annual O&M costs. The cost per unit volume of recovered or treated water can be evaluated against the revenues from water sales, the costs of other storage and treatment options, or the value generated from the use of the unit volume of water.

5.5.1 Site Location, Integration into Wastewater Treatment Infrastructure, and Other Logistical Issues

MAR systems should be constructed at locations that are readily integrated into current or planned future wastewater treatment and reuse infrastructure. Constructing dedicated transmission mains to a distant, isolated MAR facility can be cost-prohibitive. The most practical locations for MAR systems are either in the vicinity of WWTPs or at the point of RQTSE use. The latter, for example, could be an existing or planned agricultural or recreational area. Another alternative is to construct the system at a logistically or hydrogeologically favorable location along an RQTSE transmission main.

An MAR system could be constructed as an integral component of a reuse system expansion. In addition, an ASR system near the point of use may be used to ensure a reliable, year-round supply to reuse water customers. The MAR system may also be used to polish part of the RQTSE flow so that it meets higher water quality standards such as those for unrestricted irrigation. An ASTR or SAT system could be used to provide polishing benefits and reduce the stigma associated with wastewater reuse.

Economics of groundwater recharge

“in assessing the benefits of artificial recharge, consideration must be given to the importance of water to the total economy, to the value of water for various uses, as well as to the direct and intangible benefits that may accrue.”

-Todd (1965)



There are a number of other logistical and infrastructure issues that are important in determining the most favorable location for MAR systems:

• Land availability

• Site accessibility, including for drilling and maintenance equipment and the distance from system operations staff base

• Availability of electrical power supply

• Site security (from vandalism and impacts from natural processes, such as flash floods in wadis)

• Environmental concerns (e.g., nearby sensitive environments)

• Historical and cultural impacts

• Local political and public support for or opposition to the project

All of the above need to be considered in the evaluation of potential locations for MAR systems. However, an important caveat is that logistically convenient locations for an MAR system may not be ideal from a hydrogeological perspective. Trade-offs between logistical convenience (and associated cost benefits) and likely system performance need to be carefully weighed.

5.5.2 Well Capacity and Depth Well construction is a major cost item for ASR and other MAR systems that use wells for recharge and recovery. Well construction costs are a function of well depth and diameter, casing materials, completion (e.g., open hole versus screened), the number of surface and intermediate casings, the testing program, and local well drilling costs. Well construction costs are related to depth, with deeper wells costing more because of the increased materials used (e.g., casing and cement), longer drilling times (and thus labor costs), and often the requirement that high-capacity equipment be used. There is thus a clear cost advantage for using shallower aquifers as storage zones.

Deeper wells also have greater O&M requirements. Injection wells normally require periodic rehabilitation to maintain their performance, which is typically quantified using specific injectivity (injection rate divided by increase in head/pressure). Rehabilitation of deeper wells is also more difficult and time-consuming, and thus expensive, than for shallower wells.

Depth to water is also a significant O&M cost consideration. The depth to water depends upon static water level, pumping rate, aquifer hydraulics, and well efficiency. The power required for pumping is directly related to the total dynamic head (TDH), the primary component of which is the depth to water in a well. Greater TDHs result in the need for more powerful pumps and greater energy costs.

Well capacity (yield) is also an important economic factor for MAR systems. There are clear cost advantages if the target injection and recovery capacity of a system can be achieved using few wells. The cost savings come from both well drilling and surface infrastructure (e.g., wellheads, piping, and instrumentation). Well capacity, which is commonly quantified in terms of specific capacity, is primarily a function of the aquifer transmissivity. Well efficiency is also an important factor in controlling well capacity, particularly where capacity is reduced through clogging of the well screen, borehole wall, and/or the aquifer adjacent to the borehole.

An important lesson associated with the historical implementation of ASR is that very high transmissivities, and thus well yields, tend to be indicators of lower REs for chemically bounded systems using brackish or saline water aquifers (Maliva and Missimer, 2010). The



very high transmissivities in some failed systems were due to groundwater flow being dominated by secondary porosity (fractures or karstic solution networks), with associated rapid, extensive migration of injected waters and high degrees of mixing of stored water and native groundwater.

Tradeoffs, therefore, may also exist in the choice of storage zones. The aquifer that is most economically attractive in terms of water quality, depth, and well capacity may have hydrogeological characteristics that are less favorable for MAR system performance. The additional construction and O&M costs associated with the use of deeper, more hydrogeologically favorable aquifers may make projects economically unviable, particularly given the relatively low economic value of RQTSE.

5.5.3 Well Clogging and Rehabilitation Injection wells, in general, are prone to clogging, or plugging, which can result in a dramatic decrease in well performance. The clogging may occur at the well screen, borehole water, or aquifer adjacent to the borehole. Clogging can be caused by a number of physical, chemical, and biological processes, including filtration of suspended material, mechanical jamming (particle rearrangement), biological growths, chemical precipitation (scaling), clay swelling and dispersion, and gas binding. Well clogging mechanisms and rehabilitation options in MAR wells were reviewed by Maliva and Missimer (2010).

Clogging is, unfortunately, a normal part of MAR well operation. The need for well rehabilitation should, therefore, be considered in initial cost-benefit analyses, system design, and O&M budgeting. Well rehabilitation includes two main types of activities: routine backflushing and periodic major well rehabilitation. Backflushing consists of pumping a MAR well during recharge for a short period of time (typically 15 minutes or less). The reversal of flow mobilizes and removes material that accumulates on the well screen or borehole. Backflushing frequency depends upon system-specific performance and the quality of the injected water, and can range from every several days to weeks (much less frequent for potable water systems).

Major well rehabilitations are performed much less frequently (annually or less frequently) and involve more chemical and/or physically intensive treatments such as acidification, chlorination, brushing, swabbing, jetting, liquid carbon dioxide treatment, and sonic treatments. Major well rehabilitations are normally performed when backflushing no longer results in a satisfactory restoration of well performance.

Both backflushing and major well rehabilitation schedules and methods involve adaptive management, and there is no one schedule or method that is optimal for all systems. Some experimentation should be performed during the initial operation of an MAR system to determine the schedule and methods that yield the most cost-effective improvement in system performance. A key design issue for MAR systems is that the wellheads should allow for pumping of the backflushed water to waste and allow for convenient equipment access to the well for rehabilitation activities.

RQTSE MAR systems are particularly susceptible to biological clogging, which involves the formation of biofilms on well screens, filter packs, and the borehole wall. Bacteria preferentially grow where their food is most abundant, which is at well screen openings and in the filter pack (Huisman and Olsthoorn, 1982). RQTSE by its nature tends to have high organic and nutrient content, which is favorable for biological growth. The introduction of oxygen also stimulates the growth of the native microbial populations in wells (Mansuy, 1999). It is therefore recommended that chlorine residual (2 to 5 mg/L total chlorine residual) be maintained in injected RQTSE in order to control biological growth. Field data have shown that when disinfection is performed using methods that do not leave a residual (such as UV or ozone), biological well clogging can be very rapid.



5.6 General Hydrogeology The hydrogeology of KSA can be subdivided into two major geological and physiographic units, the western Arabian Shield (Crystalline Najd), in which crystalline rock is present at or near land surface and the Sedimentary Najd and Eastern Province (Sedimentary Sequence), which is underlain by a thick deposit of sedimentary rock (Ministry of Agriculture and Water, 1994). The sedimentary rock strata dip to the east (i.e., beds slope downward to the east), so that progressively younger rocks are encountered at land surface from the center of KSA to the Arabian Gulf coast (Figure 5-9).

The eastern and western parts of the Kingdom have distinctly different hydrogeological conditions due to their different geological conditions. The sedimentary strata that underlie the eastern half of the Kingdom contain multiple aquifers, separated by less permeable confining or semi-confining strata. The crystalline rock of the Arabian Shield, with the exception of shallow fractured and weathered zones, is essentially impermeable and forms the base of the local groundwater system. The only significant aquifers are shallow, coarse-grained alluvial sediments that were deposited in wadi channels and some aquifer systems found within basalt harrats. The wadis along the western coast originate in the eastern Highlands (Hijaz Escarpment) and extend in a generally westward direction to the Red Sea.

Recharge rates in both the eastern and western parts of the Kingdom are low, with the overall average rate being less than 5 mm per year (Ministry of Water and Electricity, 2009). The mountainous areas of the western part of the Arabian Shield have significantly greater than average rainfall and recharge and thus have greater renewable groundwater resources in the wadi aquifers. However, wadi aquifers have low storage volumes and are vulnerable to rapid depletion. The aquifers of the eastern part of the Kingdom have very large storage volumes from recharge during earlier wetter (pluvial periods), but are also vulnerable to depletion because of very low current recharge rates. Water levels in these fossil aquifers are declining due to extensive agricultural withdrawals and, to a lesser extent, withdrawals for municipal potable supply.

5.7 Greater Riyadh Area The history of water supply development for the Greater Riyadh area was reviewed by the Ministry of Agriculture and Water (1984) and Al-Mutaz (1987). The earliest water supply sources were natural springs and seeps, and then shallow wells constructed in Wadi Hanifa and its tributary wadis. Utilization of the sedimentary bedrock aquifers started once the wadi aquifers became inadequate to meet growing demands, with the shallow Jubaila Aquifer being the first exploited. A management pattern then developed: (1) moving production farther away from the city to reduce local drawdowns and (2) construction of wells in deep aquifers, particularly the sandstone Minjur and Wasia-Biyadh Aquifers. The Minjur Aquifer contains brackish water that is treated by RO desalination.

In 1983, Riyadh began to receive desalinated water from Al-Jubayl on the Arabian Gulf coast, which is blended with brackish groundwater near Riyadh. Groundwater is still an important source of drinking water (roughly half of the water supply). The city currently derives its groundwater from 249 production wells, 228 of which are deep wells generally completed in the Wasia, Biyadh, and Minjur Aquifers. The remaining 21 wells are shallow wells located in the Wadi Nisah area, approximately 40 km south of the city (High Committee for Environmental Protection of Riyadh, 2010a). The Hunai wellfield has been added, tapping the limestone Umm Er Radhuma Aquifer, far to the east of Riyadh. Additional wellfields are currently planned, including extending the existing Wasia-Biyadh wellfield to the south.



FIGURE 5-9 Geological map of the Arabian Peninsula Source: Pollastro et al. (1997)

Primary sources of information on the general hydrogeology are Powers et al. (1966) and Ministry of Agriculture and Water (1984). The general geological structure includes eastward-dipping sedimentary formations of Cretaceous to Jurassic age (Table 5-2), overlain



locally by Miocene-Pliocene lacustrine limestones and gravels of the Kharj Formation, or more widely by Recent and Quaternary alluvial deposits. The hydrogeology of the greater Riyadh area is divided into shallow and deep aquifers. The shallow aquifers consist predominantly of wadi alluvial aquifers, which are locally hydraulically connected (to varying degrees) to underlying fractured and fissured rock belonging to the Kharj Formation, Sulaiy Formation, Arab Formation, and upper Jubaila Formation. These formations form the bedrock beneath the alluvial sediments in the Greater Riyadh area. The Jubaila Formation is present mainly west of Wadi Hanifa, and the Arab Formation, Sulaiy Formation, and Kharj Formation are present east of Wadi Hanifa.

5.7.1 Wadi Aquifers As noted previously, wadis are ephemeral streams that are normally dry except during and following significant rainfall events. Wadi aquifers are unconfined and are composed of alluvial sediments, which are cobble, granule, sand, silt, and clay-sized siliciclastic material. The sedimentologic and hydraulic properties of wadi aquifers are highly variable both between different wadis and along different reaches of a single wadi.

Wadi aquifers, as unconfined aquifers, are susceptible to anthropogenic contamination. Contamination sources include industrial activities in the watershed and wadi, agricultural operations, household septic systems, and WWTP effluent discharges.

Wadi Hanifa (including its tributaries) extends through the Greater Riyadh area and is a critical resource for the city. Most of the city lies in its drainage. It was the original water source for the city and the wadi sediments are also an important source of building materials. Wadi Hanifa also represents the natural drain within the city (Alhamid et al., 2007). In addition to periodic storm flows, Wadi Hanifa is used for the disposal of sewage effluent, agricultural drainage water, and dewatering effluent. The latter is very important as groundwater levels in parts of the city have risen considerably, as in many other urban areas in the Middle East and North Africa. Water levels within alluvial deposits keep the deposits locally saturated to within 2 to 5 m of the surface and extensive pumping of alluvial aquifers is being carried out to reduce high water tables adjacent to large structures (High Committee for Environmental Protection of Riyadh, 2010b).

The alluvial aquifer system is still the basis for agricultural development along Wadi Hanifa. Water is extracted using wells completed in the wadi alluvium. Wadi Hanifa is the primary discharge point for the Southern (Manfouha) WWTP, which has an average day flow of 190,000 m3/d (Al Jasser, 2011), with plans for future expansion. Farms are present downstream (south of Riyadh), but only for approximately 40 km, where the largely anthropogenic flow of surface water disappears beneath surface sands (Winslow and Maliva, 2010). The location where surface water flow ceases roughly corresponds to the western boundary of the highly karstic Arab Formation, although the occurrence of surficial sand deposits may also play a role in the disappearance of this flow.

Although Wadi Hanifa has flowing water only during and after rainfall events, the combination of rising groundwater levels and discharges to the wadi has resulted in perennial lakes and stream reaches and the formation of wetlands and marshes (Alhamid et al., 2007). Both the surface water and groundwater in Wadi Hanifa are contaminated and are considered unsuitable in their present state for any use except supplying natural habitats. However, the groundwater quality is better than the surface water quality, which is evidence that the alluvium acts as natural filtering and cleaning system (Alhamid et al., 2007).



TABLE 5-2 General Geological Structure of the Greater Riyadh Area

Formation Age Thickness

(m) General Lithology Hydrogeology Alluvial Sediments Recent –

Quaternary 5 – 50 Mostly consolidated sand

and gravels intermixed and interbedded with silt and clays

Thick deposits in wadis form aquifers; poor quality water due to contamination

Kharj Formation Miocene - Pliocene

5 – 50 Lacustrine limestone with interbedded gypsum and gravel

Not a water source

Wasia-Biyadh Early to Middle Cretaceous

500 (in outcrop area east of Riyadh)

Quartz sandstones and interbedded shales, dolomites, and limestones

Primary aquifer, significant source of high quality water

Cretaceous-Jurassic

Sulaiy Formation Yamama Formation Buwaib Aquifers

Early Cretaceous

20 – 100 Low-permeability micritic to calcarenitic limestones

Not a significant water source

Hith Anhydrite

Late Jurassic

0 - 90 500 Anhydrite or solution breccias


Upper Arab Formation

Late Jurassic

10 – 50

Calcarentic and aphantic (very fine-grained) limestones, dolostones


Lower Arab Formation (Arriyadh Aquifer)

Late Jurassic

5 - 100

Calcarenitic and aphantic limestones, dolostones; fractured

Variable well yield, but water contaminated and highly mineralized in the Riyadh area

Jubaila Formation

Late Jurassic

100 - 150

Aphantic limestones and dolostones

Upper part productive where fractured, otherwise very low hydraulic conductivity

Hanifa Formation Late Jurassic

110 Aphantic limestones and dolostones, oolitic, limestone


Tuwaiq Mountains Formation

Middle Jurassic

140 Aphantic limestones and dolostones


Dhruma Formation Middle Jurassic

375 Aphanitic and calcarenitic limestones and subordinate shales and dolostones

Local water source

Marrat Formation Early Jurassic

120 Aphanitic and calcarenitic limestones and interbedded shales

Confining unit

Minjur Formation Late Triassic

400 Non-marine fine- to very coarse-grained quartz sandstone with intervening shales and mudstones

Principal aquifer; major water source for Riyadh

Jihl Formation Middle to Early Triassic

326 Thin-bedded limestones with minor sandstone, shale, and gypsum

Secondary aquifer

Sources: Powers et al. (1966), Ministry of Agriculture and Water (1984), Edgell (1997), Alsharhan et al. (2001), and High Committee for Environmental Protection of Riyadh (2010a).



The contaminated water has a higher salinity than the underlying freshwater, allowing the interface between the two waters to be detected using surface resistivity geophysics (Fnais, 2010). The interface between the contaminated water and freshwater was identified at about 100 m horizontally from the main channel and vertically at a depth of 20 m (Fnais, 2010).

Wasia-Biyadh Aquifer The Wasia-Biyadh Aquifer consists predominantly of quartz sandstones interbedded with shales, marl, limestone, and dolomite. The Biyadh Sandstone is of Early Cretaceous age, and the overlying Wasia Formation is of Middle Cretaceous age. The Wasia Formation and Biyadh Sandstone form a single aquifer, although confining beds apparently locally separate these formations. The outcrop (and recharge area) of the aquifer is located east of Riyadh. The aquifer is not present under the city itself, where the bedrock is older. The aquifer is approximately 500 m thick in its outcrop area. The water quality at the outcrop is good, and the aquifer is a significant source of water for the city of Riyadh. In the Al Khourais area, located approximately 150 km east-northeast of Riyadh, the aquifer was reported as providing large yields of groundwater containing 500 to 1,500 mg/L TDS. Well yields at the Wasia WTP reportedly range from 2,160 m3/d to 5,520 m3/d (median = 4,800 m3/d; Deutche Gessellschaft für Technische Zusammenarbeit [GTZ], 2006).

Cretaceous-Jurassic Aquifer The Cretaceous –Jurassic (C-J) Aquifer consists of the Sulaiy-Yamama-Buwaib subaquifers, the Hith Anhydrite, and the Arab and Jubaila subaquifers. The Biyadh Sandstone is underlain by generally low-permeability limestones belonging, in descending order, to the Buwaib Formation, Yamama Formation, and Sulaiy Formation of Early Cretaceous to Late Jurassic age. The underlying Hith Anhydrite is of Late Jurassic age. Anhydrite and gypsum beds within the Hith Anhydrite, where present near land surface, are subject to dissolution. The Sulaiy-Yamama-Buwaib subaquifers and Hith Anhydrite strata are generally not significant water sources in the Greater Riyadh area. However, fracture zones in the Sulaiy and upper Arab Formation provide opportunities for hydraulic connection between the surface formations and the deep Arriyadh subaquifer (lower Arab Formation) in the eastern part of the city (High Committee for Environmental Protection of Riyadh, 2010a).

Arab Formation The Late Jurassic strata in the Greater Riyadh area is approximately 500 m thick and consist, in descending order, of the Arab, Jubaila, Hanifa, and Tuwaiq Mountain Formations (Okla, 1986). The Arab Formation consists of calcarenitic and aphantic limestones, dolostones, and anhydrites of late Jurassic age. The Arab Formation is exposed in the Greater Riyadh area. The anhydrite beds may be leached away at surface exposures. Well yields from the Arab Formation are reported to vary depending on location. The Arab Formation is a shallow unconfined aquifer in the Riyadh area and is contaminated and has highly mineralized water.

The lower part of the Arab Formation in the Riyadh area contains a fractured limestone associated with anhydrite solution and rock collapse referred to as the Arriyadh Aquifer. Pumping tests have indicated transmissivities in the Arriyadh Aquifer to range from less than 100 m2/day to over 5,000 m2/day, with a typical value of 500 m2/day (High Committee for Environmental Protection of Riyadh, 2010a). The average TDS concentration of the Arriyadh Aquifer was reported to be 2,500 mg/L.

Jubaila, Hanifa, and Tuwaiq Mountain Formations The Jubaila, Hanifa, and Tuwaiq Mountain Formations are lithologically similar to Arab Formation in that they are composed of aphantic and calcareous limestones and subordinate dolostones, which generally have very low matrix (unfractured rock) hydraulic conductivities.



Powers et al. (1966) reported that water from the Jubaila Formation is mainly derived from openings resulting from weathering and jointing, rather than from porosity inherent in the rocks themselves. The Jubaila Formation is lithologically diverse and is composed of a lower unit of aphanitic limestones, partially dolomitized limestones, dolostones, and shales. The Upper Jubaila Formation contains dolostones and brecciated fossiliferous aphanitic limestones (biomicrites) (Okla, 1986). Fracture zones in the Jubaila and overlying Arab Formation and Sulaiy Limestone, combined with the overlying alluvial sands and gravels, make up a significant aquifer system with typical transmissivities between 1,000 and 3,000 m2/day (High Committee for Environmental Protection of Riyadh, 2010a). As is often the case in fractured rock terranes in general, overlying alluvial sediments provide the storage for fractured rock systems, which have a low storativity.

The Jubaila Formation water is usually of moderate to poor quality and is used mainly for agriculture. The aquifer is vulnerable to contamination from sewage infiltration in Riyadh, which was a greater issue in the past before the construction of WWTPs (SOGRÉAH, 1967). Naeem et al. (1984) reported TDS concentrations of 2,825 to 2,916 mg/L.

The Hanifa Formation is a relatively pure carbonate unit that is not a significant water source in the Greater Riyadh area. It is lithologically diverse, containing fossiliferous and oolitic calcarenites, argillaceous limestones, and calcareous shales. The Tuwaiq Mountain Formation consists of relatively competent limestone and has a tendency to form sheer cliffs. The western boundary of the formation is essentially marked by westward-facing cliffs located west of the city of Riyadh. The Tuwaiq Mountain Formation is also not a significant source of water.

Dhruma Formation The Dhruma Formation in the Greater Riyadh area consists of limestones (aphantic and less commonly calcarenitic) and subordinate marine shales and dolostones of Middle Jurassic age. South of latitude 23°N, the Dhruma Formation and underlying Minjur Formation combine to form the Minjur/Dhruma Aquifer. The Dhruma Formation is not a significant water source in the Riyadh area, but is reported to have moderate to good yields to the south (south of latitude 22°N) where there is a change in lithology from mostly limestone to mostly sandstone.

Marrat Formation The Marrat Formation (Lower Jurassic) lies between the Dhruma Formation and Minjur Formation. It is reported to consist mostly of aphanitic and calcarenitic limestones and interbedded shales. The shales, siltstones, and aphanitic limestones of the Marrat Formation generally act as an upper confining unit for the Minjur Aquifer.

Minjur Formation The Minjur Formation is composed of a consistent lithology of very fine- to very coarse-grained quartz sandstones (mostly medium-grained), with subordinate shales, siltstones, and conglomerates (Al-Aswad and Al-Harbi, 2000). The top of the Minjur Sandstone in central KSA is marked by a downward transition from marine limestones of the lower Marrat Formation to non-marine quartz sandstones of the Minjur Formation. The Minjur Formation quartz sandstones are separated into two aquifers by 150 m of intervening shales and mudstones. The Upper Minjur Aquifer is the primary production zone, as the lower Minjur Aquifer contains poorer quality water. The transmissivity in the Minjur Sandstone in the Greater Riyadh area varies from 1.7 x 10-3 to 7.2 x 10-3 m2/s (147 to 666 m2/d) and TDS ranges from 1,400 to 1,600 mg/L (Alsharhan et al., 2001). In the Greater Riyadh area, the Minjur Formation ranges from 1,500 to 2,300 m below land surface. As a confined aquifer with low recharge, the Minjur Aquifer is vulnerable to over-draft and has experienced a rapid



decline in water levels. A water level decline of 75 m occurred in wells in the Riyadh area by 1979 (Williams and Al-Sagaby, 1982).

Jihl Formation The Jihl Formation (Middle to Early Jurassic) underlies the Minjur Formation and is a secondary aquifer in KSA. The Jihl Formation consists of thin-bedded limestones with minor sandstone, shale, and gypsum. The Jihl Formation is known to contain a considerable amount of water because of its great thickness. A well east of Riyadh was reported to yield 63 liters per second (L/s) (Ministry of Agriculture and Water, 1984). Nevertheless, the Jihl and underlying units (e.g., Khuff Formation) are not considered viable storage zones for RQTSE in the Greater Riyadh area because of their great depths and associated well construction costs.

5.8 Makkah Region (Jeddah, Makkah, and Al Taif) The geology of the Makkah region consists of Precambrian (Proterozoic) igneous and metamorphic (crystalline) plutonic rocks that are overlain by Tertiary to recent sedimentary rocks and sediments, and locally basalts. The Precambrian crystalline rock forms the base of the groundwater system, although the crystalline rock may contain some usable water where it is fractured near land surface. The main aquifers are alluvial (wadi) deposits, and the Mid-Tertiary to Quaternary basalts (harrats) and underlying associated sediments. Western KSA does not have the series of productive Triassic to Neogene sedimentary aquifers that are present in the central and eastern part of the country, and thus has much more limited water resources.

Wadi aquifers found in valleys dissected into the crystalline bedrock are the primary groundwater source in the region. Cities of the region initially obtained their water supply from shallow wells in local wadis. As population and associated water demands increased, water was imported from more distant wadis. Wadi aquifers have experienced declining water quality (e.g., elevated salinity, nitrates, and coliform bacteria), particularly downstream from developed areas. The water in wadi aquifers located upstream of cities and agricultural areas may still be suitable for potable use.

Basalts are locally an important water source, but vary greater in their hydraulic properties. Massive basalt is essentially impermeable. However, basalt deposits may contain cervices, joints, and fractures that are effective flow zones. Basalt deposits often have zones of vesicular and intensely fractured basalt and sediments (interflow zones) that have both a large storage volume and high transmissivity. Alluvial sediments below basalt flows may also have considerable volume of water in storage.

Potable water is now being increasingly supplied by seawater desalination facilities located on the Red Sea coast. However, groundwater is still an important water source for some cities and is also a potential back-up source of water in the event of a disruption to the desalinated water supply.

5.8.1 Jeddah The near-surface geology of the Greater Jeddah area consists of alluvial wadi deposits and marine limestones along the coast that overlie plutonic rock of the Arabian Shield. Water supply has historically been a serious challenge for Jeddah (Ministry of Agriculture and Water, 1984). Water was initially supplied to the city from local springs. Seawater desalination (distillation) was initiated in 1907. The major groundwater sources used for the city are Wadi Fatimah (approximately 55 km to the east) and Wadi Khulays (approximately 70 km to the north) (Ministry of Agriculture and Water, 1984). By the mid-1970s, the withdrawals from the wadis were severely depleting the aquifers, and it was determined that



municipal use should be curtailed in favor of agricultural use and that seawater desalination should be used to meet the water demands of Jeddah (Ministry of Agriculture and Water, 1984).

Jeddah is located between two large wadis, Wadi Fatimah to the south and Wadi Usfan to the north. A number of smaller wadis are present in the Jeddah basin (watershed), which Al-Sefry and Şen (2006) described as containing three subbasins. Anthropogenic contamination in Wadi Marwani, located northeast of Jeddah, is evident by increases in salinity and nitrate concentrations (Al-Ahmadi and Al-Fiky, 2009).

Jeddah, like a number of other cities in the Middle East, has been experiencing rising groundwater levels, due to leakage from water and sewage mains, irrigation return flows, exfiltration from cesspool and septic systems, discharges of sewage to wadis, and other sources (Al-Sefry and Şen, 2006). The fundamental reason for the water table rise is that the net import of freshwater into the city from desalination and external groundwater sources exceeds the capacity of the shallow aquifers to transmit the water to discharge areas. Water levels were reported to have risen on average 0.41 m over a 4-year period (1996 to 2000; Al-Sefry and Şen, 2006). Rising water levels within the city of Jeddah limit the potential for local aquifer recharge, which could exacerbate the problem.

5.8.2 Makkah al Mukarramah The main groundwater supply for the city of Makkah is alluvial deposits of Wadi Naaman (Na’ man) and Wadi Fatimah. For over 12 centuries, Wadi Naaman was the main water supply for Makkah. Until the 1970s, the most important water source was a qanat, Ain-Zubaidah, in Wadi Naaman, which was constructed in 174 AH (Anno Hegirae) or 790 AD (Anno Domini ) (Es-Saeed et al., 2003). Approximately 90 percent of the potable water for the city of Makkah is now supplied from the Shuaiba desalination facility on the Red Sea coast.

In general, the slopes of wadis decrease downstream, resulting in a downstream decrease in energy and associated decreases in grain size and hydraulic conductivity. The thickness of the alluvial deposits and the thickness of the vadose zone (depth to the water table) tend to increase downstream (Şen, 2008). Water quality tends to decrease downstream, potentially due to major anthropogenic factors.

The hydrogeology of Wadi Naaman is fairly typical of western KSA. The thickness of the alluvial deposits increases from 3 to 15 m in upstream areas to more than 50 m farther downstream (Subyani, 2010). The aquifer also includes underlying weathered crystalline bedrock. The average transmissivity was reported to be 140 m2/d and TDS concentrations in the upstream reaches were reported from a study in the late 1970s to range from 440 to 1,123 mg/L (average 923 mg/L) (Subyani, 2010). Es-Saeed et al. (2003) reported an average estimated transmissivity of 355 m2/d for the upper reaches of the Wadi Naaman system and average saturated and unsaturated thickness of 8.75 m and 34.17 m, respectively. Considerable storage volume is, therefore, potentially available for recharge. Salinity increases downstream of the confluence with Wadi Uranah, and water quality declines further downstream with due to wastewater effluent (Es-Saeed et al., 2003).

A need for strategic reserves was recognized to manage a planned or accidental shut-down of the desalination plant or pipeline. The threat would be exacerbated if the shutdown were to occur immediately before or during the pilgrimage season. Construction of a subsurface groundwater dam across the Wadi Naaman Aquifer was proposed in order to provide Makkah with a strategic (emergency) source of water (SERCAP, 1983; Es-Saeed et al., 2003; Al-Ghamdi, 2009; Khairy et al., 2010). The recommended construction material was plastic (high-bentonite) concrete installed using diaphragm wall techniques. The dam would impede the downstream flow of fresh groundwater, which would mound on its upstream side.



The hydrogeology and water quality in Wadi Fatimah are discussed by Sharaf et al. (2001). The Wadi alluvium ranges in thickness from a few meters upstream to a maximum of about 100 m in the downstream part of the wadi near the Red Sea. Hydraulic conductivity was reported to range between 10 and 90 m/day. There has been a tremendous increase in water use from the wadi for domestic, livestock, and industrial purposes, resulting in an increase in salinity from both lateral intrusion and up-coning. TDS increases from less than 1,000 mg/L in upstream parts of the aquifer to over 10,000 mg/L downstream.

Wadi Yalamlam has been the subject of several hydrogeological studies in recent years as it is one of the major undeveloped wadis in the Makkah area (Subyani and Bayumi, 2001; Bayumi, 2008). Wadi Yalamlam is located approximately 125 km southeast of Jeddah and 70 km south of Makkah city. This wadi is unusual in that its upper reaches have surface water flow most of the year, because of relatively high rainfall in its source, the Hijaz Scarp Mountains. The aquifer consists of wadi alluvium and underlying weathered bedrock. Pumping test data indicate a transmissivity of about 120 m2/d at Sa’diyah, where the aquifer is 6 to 12 m thick, and about 500 m2/d further downstream in the Almigat area, where the aquifer is 15 to 38 m thick (Subyani and Bayumi, 2001). The downstream increase in transmissivity was attributed to an increase in the thickness of the aquifer. The TDS concentration of the aquifer was reported to be 1,450 to 1,835 mg/L.

5.8.3 Al Taif The history of water supply for the city of Al Taif was reviewed by Shaiba (1998). The traditional source of water was hand-dug wells in local wadis, particularly Wadi Wajj, which bisects the city. As additional sources were needed, new supplies were obtained from horizontal wells, locally called dobool (also known regionally as qanats and aflajes).Water is also locally obtained from wells completed in the fractured crystalline bedrock. In order to obtain further supplies, wellfields were constructed at Wadi Tarabah and Wadi Aradhah, located some 130 km southeast of Al Taif. Al Taif now receives potable water from the Shuaiba desalination facility located on the Red Sea coast.

The hydrogeology and hydrochemistry of Wadi Wajj at Al Taif are discussed by Al-Shaibani (2008). The wadi aquifer consists of fine- to coarse-grained sediments with depths to bedrock from a few meters to 20 m. The aquifer also includes at its base fractured and weathered crystalline rock. The aquifer has a limited lateral extent. The hydraulic conductivity of the alluvial sediments was estimated to be 20 to 54 m/d based on its grain-size distribution and 10 to 40 m/d based on results of two pump tests.

The Wadi Wajj illustrates the water quality changes that occur as wadis extend through urban areas. A pronounced difference in water quality occurs between upstream and downstream groundwater sampling locations. The wadi aquifer upstream of the city, and thus up-gradient from the main presumed contamination sources, contains freshwater of good quality. The downstream groundwater has elevated TDS, nitrate, phosphate, chloride, and coliform bacteria concentrations. The TDS concentrations from several studies were reported as 530.6 to 837 mg/L for upstream groundwater samples and 2,097 to 3,149 mg/L for downstream groundwater samples. Potential contamination sources include infiltrated sewage water, wastewater effluent discharged to the wadi, urban runoff, leachate from poultry farm wastes, leakage from sanitary sewer systems, and contamination of wells with sewage water during floods (Al-Shaibani, 2008).

5.9 Madinah al Munnawarah The city of Al Madinah is located on the Arabian Shield within the belt of Mid-Tertiary to Quaternary basalts (harrats). Lava flows are adjacent to the southern, eastern, and western boundaries of the city. The major basalt field, Harrat Rahat (18,100 km2), is located south of Al Madinah, and the Harrat Khaybar, Hutaym, and Kura Complex (21,400 km2) is located to



the north (Ministry of Agriculture and Water, 1984). The latest volcanic eruptions in the Al Madinah area are recorded to have occurred in year 1256 A.D.

The geology of the Al Madinah area consists of five main units (ItalConsult, 1978):

• Recent cover of alluvial and eolian sediments

• Tertiary and Quaternary volcanics (basalts of the harrats)

• Tertiary sedimentary rocks (sub-basaltic alluvial deposits)

• Paleozoic sedimentary rocks

• Basement complex (Precambrian crystalline rock)

The major local aquifer consists of basalt flows of Harrat Rahat (to the south) and sub-basaltic alluvial deposits, which are hydraulically connected to form a single aquifer complex. The historic water sources for the city were wadi aquifers and springs that drained the sub-basaltic alluvium. A wellfield (Ayn Zarqa) was later constructed in the vicinity of the springs, which increased water production but reduced spring flow (ItalConsult, 1978). Reported pumping rates at the wellfield were 5 to 25 L/s (432 to 2160 m3/d) (ItalConsult, 1978). The main wadis in the immediate city vicinity are Wadi Aqiq, Qana, and Al-Himd, which are the major drainages for the city (Matsah and Hossain, 1993). Al Madinah now receives desalinated seawater from the Red Sea. However, groundwater from Harrat Rahat is still an important water supply source for the city. Additional desalinated seawater supply is planned, although groundwater currently provides for roughly half of the city’s potable water supply. Wadi aquifers are used for agricultural water supply in outlying communities (ItalConsult, 1978). Groundwater quality (salinity) in the Al Madinah area is highly variable (ItalConsult, 1978).

The city of Al Madinah obtains water from three wellfields located in the northern Harrat Rahat. The production zone is the uppermost weathered basement (bedrock), sub-basalt alluvium, and densely fractured, jointed, and vesicular basalts that characterize the lower part of the lava sequence (Al-Shaibani et al., 2007). Pumping test data indicate a very high degree of variation in calculated transmissivities, ranging from 1 to 13,300 m2/d, which is typical of fractured terrains (Al-Shaibani et al., 2007). Pumping rates from the three Al Madinah wellfields were reported to average about 1,000 m3/d (Al-Shaibani, 2007). The native groundwater is reported to be of drinking water quality (Al-Shaibani et al., 2007). ItalConsult reported highly variable TDS concentrations in the basalt aquifer, ranging from 510 to 5726 mg/L.

The Madinah WWTP provides tertiary treatment (extended sand filtration followed by sand filtration and disinfection; Al Saleem, 2007). The WWTP is located north of the city and discharges disinfected effluent into Wadi Al Hamd, where it flows northward away from the city. Downstream, the treated water is extracted by farmers for agricultural irrigation (Al Saleem, 2007). A feasibility study was performed to evaluate the piping of RQTSE directly to the farmers, with Wadi Al Hamd used for disposal of excess water (Consulting Engineering Group, CH2M HILL International, 1985).

5.10 Greater Dammam Area There are six aquifers in the Greater Dammam area, which includes the cities of Dammam, Al-Khobar, Dhahran, and Qatif. The aquifers range in age from Lower Cretaceous to Neogene (Table 5-3). The main aquifers occur primarily in carbonate rocks, and groundwater flow is largely controlled by secondary porosity (e.g., solution cavities, fractures, faults, and bedding plane openings). The Lower Cretaceous to Neogene strata dip from the west to the east in a continuous manner, locally interrupted by a serous of



north-south oriented folds (Ministry of Agriculture and Water, 1984; GTZ, 2006, v. 11, Figure 3.4). In general, salinity tends to increase to the east, from the recharge areas in the outcrop areas to the west (east of Riyadh) toward the Arabian Gulf. The groundwater flow direction is also to the east, with the pre-development potentiometric contours roughly parallel to the coast of the Arabian Gulf. Water hydrochemistry also changes down-gradient from calcium bicarbonate-type at the recharge area, to calcium sulfate-type, and then sodium chloride-type near the coast (Bakiewicz et al., 1982).

TABLE 5-3 General Geological Structure of the Greater Dammam Area

Formation Age Thickness General Lithology Hydrogeology Neogene Complex

Hofuf Formation

Late Miocene – Early Pliocene

100 – 150 m Continental deposits; fluvial sands and marls, marine limestones and marls

Unconfined; generally poor aquifer

Dam Formations

Middle Miocene

Limestones, marls, and shales. Extensive fissuring and karstification in upper part

Locally important aquifer

Hadrukh Formation

Early Miocene

Mostly non-marine, generally sandy strata; Calcareous sandstones and sandy limestones with interbedded marls and clays

Locally important aquifer

Dammam Aquifer

Alat Subaquifer

Early to Middle Eocene

100 – 120 m Light-colored chalky dolomitic limestone with a lower marl

Principal aquifer

Khobar Subaquifer

Upper fossiliferous dolomite limestone or dolomite and low marl

Principal aquifer – primary groundwater source

Alveolina Limestone

Tan limestone containing foraminifera Alveolina


Saila Limestone

Blue to gray-blue shale and marl

Confining strata

Midra Shale

Shales and clay Confining strata

Rus Formation Early Eocene

80 to 120 m Chalky limestones, dolostones, anhydrite, and marls

Confining unit, in which anhydrite is intact

Umm Er Radhuma Early Eocene

300 to 500 m Limestones, dolomitic limestones, and dolostones

Principal aquifer; Primary local groundwater source

Aruma Formation Limestone

Upper Cretaceous

300 to 450 m Limestones with subordinate dolostone and shale

Poor aquifer

Sources: Powers et al., 1966; Ministry of Agriculture and Water, 1984; Edgell, 1997; Alsharhan et al., 2001; GTZ, 2006.

The main groundwater sources in the Greater Dammam area are the Umm Er Radhuma Aquifer and the Khobar subaquifer of the Dammam Formation (Abderrahman et al., 2007).



The Neogene Complex aquifers are an important water source in the Al Hasa oases. Approximately 67 percent of the produced groundwater in the Greater Dammam area is used for agricultural purposes. The Greater Dammam area has a very high density of wells (GTZ 2006, Figure 3.16), which will be an important consideration for any RQTSE MAR project.

The Umm Er Radhuma and adjoining aquifers in the Eastern Province of KSA, including the Greater Dammam area, was the subject of a detailed investigation (GTZ, 2006). A key observation from that study was that the natural groundwater budget for the Umm Er Radhuma, Aruma, Dammam, and Neogene Aquifers is slightly negative in that natural outflows exceed current recharge. The recharge rate of the Umm Er Radhuma and Dammam Aquifers was estimated to be only 5 to 8 mm/yr (Rasheeduddin et al., 2003). Every additional extraction results in storage depletion. Groundwater pumping has dramatically increased the difference between inflow and outflow, and groundwater mining (over-draft) is taking place (GTZ, 2006). Wells completed in the Dammam and Neogene Aquifer Complexes are especially vulnerable to becoming dry on a large scale and possible deterioration of groundwater quality (GTZ, 2006).

The groundwater in the Greater Dammam area is generally not suitable for direct potable use without treatment because of high salinities. However, brackish groundwater is used for blending with desalinated water produced by the Saline Water Conversion Corporation (SWCC) seawater desalination plants. The high-purity desalinated water is piped to regional water blending stations, where it is blended with brackish groundwater to provide needed minerals and increase yields. The blended water is then chlorinated and sent to the distribution system.

Neogene Aquifer The Neogene Aquifer is the shallowest hydrostratigraphic unit in the Dammam vicinity and, historically, the first developed for water supply through the use of springs and shallow wells. The Neogene Complex aquifers are generally not an important source of water outside of the Al Hasa oasis area. Some springs outside of the Al Hasa oasis area, such as those in the oases at Qatif (west of Dammam), are located in areas where Neogene strata are present, but the flow originates from the underlying Dammam Formation (Powers et al., 1966; Ministry of Agriculture and Water, 1984; Bazuhair and Hussein, 1989). Agricultural water needs in the Al Hasa oasis area were historically met by the natural flow of water from a relatively constant spring discharge (BRGM, 1977). Farmers cultivated different crops seasonally depending on the water requirements of the various crops. More active groundwater management began in the 1970s in order to increase agricultural production.

The Al Hasa oasis agricultural area is located approximately 100 km from Dammam. Investigations have been performed to evaluate the feasibility of conveying treated wastewater from the Greater Dammam area to Al Hasa (Saudi Consulting Services, 1995); this raises the possibility of local ASR of seasonally available excess water.

The Neogene Complex is approximately 100 to 150 ft thick in the Dammam vicinity (GTZ, 2006; v. 11, Figure 3.15). The Neogene strata of the Eastern Province were deposited in terrestrial, marine, and transitional settings. As a result of the varying depositional environments, the strata have wide lateral and vertical variations in lithology and hydrogeology (Alsharhan et al., 2001). The complex consists of three formations in the Dammam region. They are, in ascending order, the Hadrukh, Dam, and Hofuf Formations.

The Hofuf Formation is a lithologically diverse unit composed of fluvial conglomerates, sands and marls, and marine limestones and marls. It is the uppermost Neogene unit and is overlain by surficial Quaternary deposits, which include aeolian sands, wadi alluvium, and lacustrine silts. The Hofuf Formation ranges in thickness from 30 to 100 m in the Eastern Province (Powers et al., 1966).



The Dam Formation is a predominantly marine unit that consists of interbedded limestones, marine marls, and shales. The Hadrukh Formation consists mostly of non-marine generally sandy strata. The main lithologies are calcareous sandstones and sandy limestones with interbedded marls, and clays. A few beds near the top of the formation were reported to locally contain marine mollusks (Powers et al., 1966).

The fractured nature and karstic properties of the Neogene Aquifers, especially the Dam and Hadrukh Formations, locally cause high transmissivities. For example, an underground karst cave system in the Dam Formation supplies the Ayn Khudud spring, the largest in the Al Hasa oasis, which is located approximately 110 km southwest of Dammam (Edgell, 1997).

The transmissivity of the Neogene Complex based on nine pumping tests in the Al Hasa oasis (Al Hofuf) area, where the aquifer is intensely used, ranges from 9.3 x 10-5 to 4.0 x10-2 m2/s (8 to 3,460 m2/d) (GTZ, 2006). The large range in values over a relatively small geographic area presumably reflects the karstic nature of the strata. The mean transmissivity and hydraulic conductivity values were 1.4 x10-3 m2/s (121 m2/d) and 1.4 x10-5

m/s, respectively. TDS in the Neogene Complex aquifers ranges from 2,500 to 4,000 mg/L in the Dammam, Dhahran, and Al Khobar area (GTZ, 2006, v. 7, Figure 4.27). GTZ (2006, v.11, Figure 4.5) indicated TDS concentrations in the combined Neogene Complex of 2,500 to 4,500 mg/L.

Dammam Formation The Neogene Complex is unconformably overlain by the Dammam Formation. The Dammam Aquifer is one of the primary aquifers of KSA and has historically been a major water source in the Dammam area. The Dammam Formation is a lithologically varied unit that is divided into five members. The members are, in ascending order, the Midra Shale, Saila Shale, Alveolina Limestone, Khobar Limestone, and Alat Limestone. The bottom three units consist of shales and clayey limestones and are not significant water sources, and with the underlying Rus Formation, constitute the confining strata between the Dammam Aquifer and the Umm Er Radhuma Aquifer.

The Khobar Limestone is approximately 40 m thick in the subsurface and is composed of an upper unit of mostly calcarenitic limestone and a lower unit of dolomitic marl. The Alat Formation has an average thickness of about 70 m in boreholes and is composed of an upper unit of dolomitic limestone and a lower marl, referred to as the Alat Marl or Orange Marl.

The Alat and Khobar Aquifers are important water sources in the Eastern Province. Both members have a distinctive and persistent marl unit that acts as a confining or semi-confining unit. The Alat and Khobar Aquifers are separate hydrogeologic units, but wells may be open to both. The aquifers were flowing artesian during the pre- and early-development periods, but water levels have locally dropped well below land surface due to intense groundwater extractions.

The hydraulic properties of the Alat and Khobar Aquifers are determined, to a large degree, by the presence of secondary porosity flow features such as fractures and karstic solution cavities, which result in high transmissivities. Well productivity is directly related to the number of fractures encountered, which are most abundant in the upper parts of both the Alat and Khobar Aquifers. The transmissivity of both aquifers is particularly high in coastal areas. The Ministry of Agriculture and Water (1984) reported transmissivities in the Khobar and Alat members in coastal areas of the Eastern Province of 0.9 x10-1 and 2.9 x10-1 m2/s, (7,780 and 2,500 m2/d), respectively. The results of two pumping tests in the Dammam Complex in the Dammam vicinity indicated transmissivities of 6.0 x 10-3 and 1.1 x 10-2 m2/s (518 to 959 m2/d; wells 4-CB-31, 4-S-23, GTZ, 2006). Harza Engineering (1986) reported an average specific capacity for Dammam Aquifer wells in the Qatif area of 15 L/s/m, with a



range of 5.1 to 42 L/s/m for an 80 percent degree of confidence, which corresponds to well yields of 25 to 2,10 L/s (2,160 to 18,144 m3/d) for 5 m of drawdown.

The TDS concentration in the Alat Formation in the Greater Dammam area (Qatif- Dammam) was reported by Hassan (1992) to be approximately 2,000 mg/L. The TDS concentration in the Khobar Formation was reported to range from 2,000 to 4,500 mg/L. Higher salinities near the coast may be due to pumping-induced saline water intrusion (Al-Zarah, 2007).

Rus Formation The Rus Formation consists of chalky limestone, partially dolomitized limestone, anhydrite, and marls. The presence of bedded anhydrite, to a large degree, determines the hydraulic properties of the formation. Continuous anhydrite beds have a very low vertical hydraulic conductivity. Thus, where bedded anhydrite is abundant in the Rus Formation, the unit acts as an effective confining zone between the Dammam Formation and underlying Umm Er Radhuma Formation. However, where bedded anhydrite is absent due to dissolution or non-deposition, groundwater flow may occur between the two formations. The Rus Formation is 80 to 120 m thick in the Dammam vicinity (GTZ, 2006; V. 11, Figure 3.13).

Umm Er Radhuma Aquifer The Umm Er Radhuma Aquifer is a principal aquifer in KSA and a very important water source in the Eastern Province because of its high transmissivity. This formation was described by Powers et al. (1966) as consisting entirely of a repeating series of light-colored foraminiferal limestones, dolomitic limestones, and dolostones. The hydraulic characteristics of the Umm Er Radhuma Aquifer are mainly controlled by the lithology of the formation and the development of secondary porosity features such as joints, fissures, and karstic solution voids (Bakiewicz et al., 1982).

The transmissivity of the upper part of the Umm Er Radhuma Formation tends to be much greater than in the lower part, with the highest transmissivities occurring where fissuring and karstic solution have occurred in the upper of units of the formation (Bakiewicz et al., 1982; Ministry of Agriculture and Water, 1984; Harza Engineering, 1986). The common occurrence of loss of circulation zones during drilling is evidence of the presence of well-developed secondary porosity. Fractured zones are also easily observed using caliper and neutron borehole geophysical logs (Harza Engineering, 1986). The average hydraulic conductivity of the Um Er Radhuma Aquifer is 0.32 m/d and 32 m/d in the unfissured and fissured portions of the aquifer, respectively (Bakiewicz et al., 1982; Alsharhan et al., 2001). Pumping tests indicate transmissivities for the Um Er Radhuma Formation in the Dammam region mostly in the 1 x 10-3 to 1 x10-1 m2/s (86 to 8640 m2/d) range (GTZ, 2006; V. 11, Figure 4.5). The formation is approximately 300 to 500 m thick in the Dammam area (GTZ, 2006; V. 11, Figure 3.12). The top of the formation occurs at about 300 m below sea level (and land surface) along the Arabian Gulf coast in the Dammam area.

The Umm Er Radhuma Formation has a very pronounced down-gradient increase in salinity to the northeast, toward the Arabian Gulf, ranging from about 300 to 1,000 mg/L in the outcrop and recharge area to over 5,000 mg/L along the coast (GTZ, 2006; V. 11, Figure 4.4). However, there is also a pronounced vertical variable in salinity, with the lower part of the formation containing water of marine or hypersaline conditions. The elevated salinities are believed to have begun during periods of higher sea levels and remain in the formation due to subsequent incomplete flushing by fresher waters (Harza Engineering, 1986). Up-coning of saline water may thus represent a greater threat to water quality in the Umm Er Radhuma than lateral saline-water intrusion.



Aruma Formation The Aruma Formation (upper Cretaceous) consists of massive limestone with subordinate dolomite and shale. In the Eastern Province, along the Arabian Gulf, the formation is divided into an upper limestone and lower shale unit. Groundwater flow is dominated by fissure and cavernous systems, and associated losses of circulation zones are frequently encountered during well drilling (Bakiewicz et al., 1982).

The upper, predominantly carbonate unit is approximately 300 to 450 m thick in the Dammam region. The top of the formation occurs between 700 and 1,000 m below sea level in the Dammam area (GTZ, 2006; V. 11, Figure 3.6). GTZ (2006) did not reference any water quality or pump test data for the Dammam vicinity, presumably because such data were not available. The Aruma Formation was interpreted to have salinities in excess of 5,000 mg/L near the coast (GTZ, 2006; V. 11, Figure 4.3). GTZ (2006) reported that the only Aruma Formation groundwater sample that was collected near the coastline (west of Salwah) had a TDS concentration of more than 12,000 mg/L. The Aruma Formation is considered to be a secondary aquifer and is not used in the Dammam vicinity because of its poor quality and great depth.

Deeper Aquifers Formations that contain aquifers used for water supply elsewhere in KSA are present below the Aruma Formation, such as the Wasia Formation. However, these deep aquifers are not considered viable candidates for an ASR storage zone in this region because of their great depth (> 1,200 m) and expected high salinities.

Wastewater Most of the wastewater in the Eastern Province of KSA, including the Greater Dammam area, receives only secondary treatment, which limits opportunities for reuse. GTZ (2006) noted that the actual wastewater reuse was less than 2 percent of the total theoretical reuse potential in 2004 and that only 14 percent of the TSE receives tertiary treatment. The Greater Dammam area is characterized by urban land uses. However, there are large oasis expanses with date palms, market garden crops, and ornamentals that would be the main beneficiaries of the use of RQTSE (GTZ, 2006).

5.11 RQTSE ASR Options in KSA A major constraint on the initial implementation of RQTSE ASR or other MAR techniques in KSA is avoiding indirect potable reuse. Systems involving the recharge of highly treated wastewater into aquifers locally used for potable water can be safely implemented, but would likely be socially unacceptable at the present time. However, successful implementation of reclaimed ASR for MAR, including demonstrations of improvement in water quality, may lessen potential opposition to future projects that include an element of indirect potable recharge.

Based on the hydrogeology of the studied areas, four main feasible RQTSE MAR concepts were identified for the Kingdom:

ASR/ASTR/ARR in downstream reaches of wadi aquifers. Wadi aquifers are important groundwater sources, particularly in the western part of the Kingdom. Studies have documented that water quality deteriorates downstream of cities due to the use of the channels for wastewater disposal (Alhamid et al., 2007; Al-Shaibani, 2008). In general, land application of wastewater in hot, arid areas is not ideal because the high evaporation rates result in an increase in salinity. RQTSE could be injected into the wadi aquifers using wells (or possibly recharge trenches or galleries constructed in the vadose zone) and recovered using either the same wells (ASR) or downstream wells (ASTR). ASTR/ARR systems could



be implemented to improve water quality, particularly the attenuation of contaminant concentrations. In general, ASTR/ARR would be preferable over ASR due to potentially greater water quality enhancements and reduced stigma associated with reuse of RQTSE.

ASR or salinity barrier systems in coastal areas. Salinity in the sedimentary rock aquifers in eastern KSA naturally increases toward the Arabian Gulf coast. Some aquifers along the coast have also locally experienced increases in salinity due to anthropogenic saline-water intrusion. Aquifers with salinity levels too high for potable use may be used as ASR storage zones. Salinity barrier systems may also be used to retard or reverse saline-water intrusion. Among the important design issues are locating and operating systems so that the injected RQTSE does not reach production wells used for potable supply, including wells that produce water is blended with desalinated water.

Over-drafted or otherwise impacted aquifers. Over-drafted aquifers have resulting storage space that could be used for RQTSE storage. One constraint is that some of these aquifers are still being used for local potable supply. Shallow aquifers that are either depleted or have become contaminated may be reserved for RQTSE storage and natural aquifer treatment. Some aquifers (such as the Minjur Aquifer) are used only with RO treatment. An ASR or ASTR system within the Minjur Aquifer far from potable supply wells may pose little risk to potable supply, in particular with RO treatment providing additional protection. However, regulatory approval of such an option would likely face significant obstacles.

Soil-aquifer treatment. Soil-aquifer treatment could be used as a polishing technique to improve RQTSE quality and to provide some storage. It could potentially be implemented throughout the Kingdom, but its feasibility depends upon local hydrogeological conditions.

5.11.1 Evaluation of RQTSE MAR Options ASR feasibility depends upon a number of logistical and hydrogeological factors. Several scoring systems have been proposed for evaluating ASR systems in which sites or systems are ranked according to a cumulative weighted score for the considered feasibility variables (e.g., CH2M HILL, 1997; Maliva and Missimer, 2010). Although it would be desirable to develop a universal quantitative system to evaluate the feasibility of ASR systems, such a goal is impractical because ASR systems vary greatly in their economic benefits, infrastructure costs, and hydrogeology (Maliva and Missimer, 2010). Instead, scoring systems should be tailored to project-specific considerations.

One objective of this study was to identify general reclaimed ASR and MAR options for the major population centers of KSA, rather than assess specific sites. Hence, the focus of the scoring system is on hydrogeological and aquifer water use issues rather than local logistical issues or site-specific concerns (such as proximity to potable water wells). The scoring system used herein (Maliva and Missimer, 2010) rates sites for each considered parameter as being either:

F = Fatal flaw. Conditions make ASR or MAR either technically or economically unviable.

0 = Unfavorable (poor). Conditions are outside of the range normally considered favorable for an ASR or MAR system, but project may still be viable.

1 = Acceptable. Conditions are favorable for meeting a minimum performance requirement, but are less than ideal.

2 = Optimal range. Condition is ideal for proposed ASR or MAR system.

The key feasibility issues for RQTSE ASR or MAR for non-potable use are summarized in Table 5-4 and are discussed below.



Aquifer water quality. A groundwater quality suitable for direct potable use (TDS < 1,500 mg/L) is considered unfavorable because of concerns over contamination of an aquifer that might be used directly for potable supply. TDS concentrations greater than 10,000 mg/L are unfavorable for high RE. Optimal values for high RE are between 1,500 and 5,000 mg/L.

Aquifer transmissivity and well yields. Well capacity affects the economic viability of projects, as low well capacities would result in a large number of wells being required to meet system storage capacities. The optimal well capacity is between 2,000 and 8,000 m3/d or (23 to 93 L/s; 0.5 to 2.1 U.S gallons per day). Higher capacity wells may be indicative of secondary porosity dominated flow, which can have very adverse impacts on RE. Well yields are ultimately determined by transmissivity. Very low well yields and aquifer transmissivities would result in a project not being economically viable.

Storage capacity. ASR systems must be able to store a sufficient volume of RQTSE to justify the investment in their construction. Storage capacity depends upon system type, aquifer areal extent, storativity, and, for physical-storage systems, unsaturated thickness. In the qualitative evaluation conducted for this project, the optimal condition was assumed to be aquifer storage capacity that is great enough not to restrict likely RQTSE system capacity, which would be the case for regional aquifers. An acceptable storage capacity system would have limited capacity, but still be sufficient for RQTSE MAR applications (capacities of 4,000 m3/d or greater). An example of an acceptable condition is a wadi aquifer with 10 or more meters of unsaturated sediments that could be used for storage. Inadequate capacities (< 2,000 m3/d) indicate unfavorable hydrogeological conditions.

TABLE 5-4 RQTSE ASR and MAR Feasibility Scoring System Summary

Parameter Fatal Flaw Unfavorable Acceptable Optimal 1 Aquifer water quality

TDS (mg/L) > 10,000 mg/L or

≤ 1,500 mg/L 5,000 ≤ x < 10,000 1,500 < x 5,000

2 Aquifer transmissivity (m2/d)

< 50 50 ≤ x <200 < 2,000

200 ≤ x <500 1,000 ≤ x ≤ 2,000

500 to 1,000

3 Aquifer storage capacity

Minimal capacity

Inadequate capacity

Adequate for anticipated MAR applications

No restrictions

4 Aquifer depth (m) > 1,500 400 ≤ x < 1,500 100 < x < 400 ≤ 100 5 Aquifer

heterogeneity and porosity type

- Karst-dominated flow

Moderate heterogeneity

Intergranular (matrix-dominated flow)

6 Storage zone confinement

- Poor Moderate Highly effective

7 Aquifer hydraulic gradient

- < 1:1,000 1:5,000 ≤ x < 1:1,000

≤ 1:5000 or gradient is beneficial (ASTR)

8 Adverse fluid-rock interaction potential

- Common reactive minerals and evaporites

Not expected to be a significant problem

High-stability mineralogy (e.g., quartz sands)

9 Aquifer potable reuse

Indirect potable reuse cannot be avoided

Widespread use of aquifer for potable supply (domestic)

Potable reuse could be avoided through system siting.

Aquifer not used for potable supply

10 Proximity to site of RQTSE supply or

- Long dedicated conveyance would

Some additional MAR could be sited near WWTP



TABLE 5-4 RQTSE ASR and MAR Feasibility Scoring System Summary

Parameter Fatal Flaw Unfavorable Acceptable Optimal use be required conveyance required or point of use

Aquifer depth. Well drilling and maintenance costs increase with depth. Total well depths of 100 m or less are considered optimal. Depths in excess of 1,500 m are considered a fatal flaw for RQTSE MAR because of the deep well construction, and O&M costs.

Aquifer heterogeneity and porosity type. High degrees of aquifer heterogeneity are unfavorable for ASR RE, as they can result in rapid and unpredictable movement of stored water and excessive mixing of RQTSE and native groundwater. Matrix- (intergranular) dominated flow is optimal, and karst-dominated flow is considered unfavorable.

Storage-zone confinement. Storage-zone confinement relates to the potential of stored water to migrate out of the storage zone and result in either a significant loss of stored water or adverse impacts to the other aquifers. Vertical confinement is quantified through the leakance value of the confining strata, which is the vertical hydraulic conductivity of the strata divided by their thickness. Leakance values are generally not available for all the aquifers in the study area. Instead, storage-zone confinement is qualitatively evaluated by the thickness and lithology of confining units, with clays and shales providing the most effective confinement. Unconfined aquifers are evaluated based on the lithology of underlying rock.

Aquifer hydraulic gradient. Large hydraulic gradients can result in the rapid movement of stored water, which is of particular concern in chemically bounded ASR systems in which the objective is to recover the actual injected water. However, a substantial hydraulic gradient may be beneficial for ASTR systems in which the gradient can be used to direct water from injection wells to recovery wells.

Adverse fluid-rock interaction potential. RQTSE is normally in chemical disequilibrium with aquifer minerals. Some fluid-rock interactions can result in clogging of wells and the aquifer and deterioration in the quality of stored water. The optimal condition is a storage aquifer mineralogy that consists only of essentially unreactive phases such as quartz sand. The default classification is acceptable, in which fluid-rock interaction should not be a significant detriment to system performance based on available information. The presence of common reactive minerals and evaporite minerals (e.g., anhydrite, gypsum, and halite) indicates unfavorable conditions.

Aquifer potable reuse. Avoidance of unintentional indirect potable reuse is an important concern for RQTSE MAR systems. In the optimal situation, the aquifer is not locally used for potable water supply. A condition is considered acceptable if there is some potable use in the study site region (e.g., desalination blend-water), but indirect potable reuse may be avoided through the site selection process. The widespread use of an aquifer for potable supply indicates an unfavorable condition. A fatal flaw condition is indicated where unintentional indirect potable reuse cannot be avoided.

Proximity to site of RQTSE supply or use. Major logistical issues and costs are associated with conveying water from a WWTP to the MAR system and then to its point of use. In the optimal situation, the MAR system can be located either near a WWTP or at a point of use (e.g., agricultural area) that is already connected to the reuse system. The need to construct a dedicated conveyance for the MAR system indicates an unfavorable condition. Acceptable conditions might involve some pipeline construction that would serve a dual function of expanding the reuse system to a co-located point of use and MAR system site.



5.11.2 Scoring of KSA MAR Options The potential RQTSE MAR options in the four studied areas are evaluated in Table 5-5 using the RQTSE ASR and MAR feasibility scoring system summarized in Table 5-4. The highest scoring options in each of the study areas are discussed below.

TABLE 5-5 Feasibility Scoring of RQTSE MAR Options

Region and Aquifer 1

- Aqu

ifer w

ater

qua

lity

2 - A

quife

r tra

nsm

issi

vity

3 - A

quife

r sto

rage

cap

acity

4

- Aqu

ifer d

epth

5 - A

quife

r het

erog

enei

ty a

nd

poro

sity

type

6 - S

tora

ge z

one

conf

inem

ent

7 - A

quife

r hyd

raul

ic g

radi

ent

8- A

dver

se fl

uid-

rock

inte

ract

ion

pote

ntia

l

9- A

quife

r pot

able

use

10 -

Prox

imity

to s

ite o

f RQ

TSE

supp

ly o

r use

Tota

l Sco

re

Makkah 1) ASR or ASTR using downstream reaches of wadi alluvial aquifers

2 1 1 2 2 2 2 1 1 1 15

Al Madinah 2) ASR or ASTR using downstream reaches of wadi alluvial aquifers

2 1 1 2 2 2 2 1 1 2 16

3) ASR using basalt aquifers (Harrat Rahat)

1 1 1 1 1 1 1 1 0 0 8

Greater Riyadh Area 4) ASR or ASTR in Wadi Hanifa and tributary alluvial aquifers

2 1 1 2 2 2 2 1 1 2 15.5

5) ASR using Cretaceous-Jurassic Aquifer

2 1.5 2 2 0.5 1 1 1 1 2 14.0

5) ASR using Wasia Aquifer 1.5 2 2 0 2 1 2 1 F-0 0 11.5 6) ASR using Minjur Aquifer 2 1.5 2 0 2 2 2 1 F-0 2 14.5 Greater Dammam Area 7) ASR using Neogene Aquifer 2 0 1 2 0 1 1 1 0.5 2 10.5

8) ASR or salinity barrier using Dammam Aquifer

2 1 2 1 0 2 1 1 0 2 12

9) ASR or salinity barrier using Umm Er Radhuma Formation

2 1 2 0.5 0 2 1 1 0.5 2 12

10)ASR using the Aruma Formation 0.5 1 2 0 1 2 1 1 2 2 12.5

F = fatal flaw, 0 = unfavorable, 1 = acceptable, 2 = optimal

Makkah Region (Jeddah, Makkah, and Al Taif) Wadi alluvial aquifers are the only potential storage zones for RQTSE in the Jeddah, Makkah, and Al Taif area. Wadi aquifers vary in their hydraulic characteristics both between different wadis and between the upstream and downstream reaches of individual wadis. Major advantages of wadi aquifers is their shallow depth, good confinement, dominance of



intergranular flow, and the possibility of taking advantage of aquifer hydraulic gradients for ASTR or ARR. The downstream reaches of wadi aquifers tend to have impaired water quality, which makes them unsuitable for direct potable use. However, the moderately brackish salinities are favorable for ASR and ASTR. MAR would be used for both storage and treatment. For example, RQTSE could be recharged using wells or subsurface galleries to avoid evaporative losses and recovered using more downstream wells. Potential aquifers are located in Wadi Naaman (Makkah), Wadi Wajj (Al Taif), Wadi Fatimah (south of Jeddah), and Wadi Usfan (east of Jeddah). ASTR/ARR would be recommended over ASR for enhanced water quality and reduced stigma associated with wastewater reuse.

Al Madinah An ASR or ASTR system may also be feasible for Al Madinah in the downstream reaches of Wadi Al Aqiq. Use of the Wadi Hamd downstream of the city also has the advantage of relatively close proximity to the WWTP and agricultural users. The system would increase the groundwater supply and improve water quality by lowering contaminant concentrations and avoiding the concentration of salt associated with evaporation of surface water discharges. The basalt aquifers (Harrat Rahat) are unfavorable for MAR because of ongoing potable use, high degrees of aquifer heterogeneity, and distance from both the wastewater supply and potential users. The salinity of the water in the basalt aquifers can be highly variable.

Great Riyadh Area Wadi alluvial aquifers (Wadi Hanifa and tributaries) could be used for ASR or ASTR systems. Recharge of RQTSE into the alluvial aquifer could serve a polishing function for the RQTSE, potentially achieving standards for unrestricted irrigation use. Injection of RQTSE would avoid the evaporative losses associated with channel discharges. A limitation for ASR is that water levels have already locally risen from discharges of treated wastewater and other flows in the channel, resulting in areas of perennial surface water.

The Cretaceous-Jurassic Aquifer in the Greater Riyadh area has the advantage of shallow well depths, locally high well capacities, suitable water quality for RQTSE ASR, and minimal municipal potable use. The aquifer has moderate salinities and has anthropogenic contamination in the Riyadh area. There is some use of the aquifer in the Greater Riyadh area as a feedwater for brackish-water desalination. An MAR option is to reserve the Cretaceous-Jurassic aquifer in some parts of the Greater Riyadh area for storage of RQTSE for irrigation use. The aquifer could be recharged with RQTSE, and then locally recovered using wells at the point of use. A key technical issue is how to ensure that recharge with RQTSE would not adversely impact current or anticipated future uses of the aquifer as a brackish feedwater source. Recharge should not exacerbate local rising water table conditions. Potential REs are also uncertain.

The deep aquifers (Wasia and Minjur) have the advantages of good water quality and well yields (transmissivity) for ASR. Their major disadvantages are great well depths, potable use, and, for the Wasia Aquifer, the distance of aquifer areas (east of Riyadh) from the wastewater source. The Minjur Aquifer underlies the Greater Riyadh area, but is a major potable groundwater source, which combined with the great well depths, makes the aquifer likely not feasible for RQTSE ASR. Regulatory acceptance of using the Wasia and Minjur Aquifers for RQTSE MAR is unlikely.

Greater Dammam Area The Neogene Aquifer is not particularly productive in the Dammam, Al-Khobar, Dhahran, and Qatif areas, but has the advantage of shallow well depths. As with all the main limestone aquifers in the Greater Dammam area, groundwater flow is dominated by secondary porosity features (fractures and karstic solution cavities), which is unfavorable for



ASR. Both the Dammam Aquifer and Umm Er Radhuma Aquifer are comparable in terms of ASR feasibility, with the former having the disadvantage of greater depth. There is a great density of potable supply wells in the Greater Dammam area, which makes well interference a critical issue. Wells used for blending with desalinated water or augmentation of the potable water supply are particularly vulnerable because the groundwater reportedly receives no treatment other than disinfection. The preferred areas for RQTSE MAR are near a coast, where a system could serve both a storage and salinity barrier function. RQTSE would be injected into the Dammam Aquifer in areas where the salinity is too high for potable use. Some existing potable supply wells may need to be decommissioned for this alternative. In addition, tertiary wastewater treatment would be needed to provide adequate layers (barriers) of protection. The Aruma Formation scores close to the Neogene, Dammam, and Umm Er Radhuma Aquifers, but is not a practical MAR storage zone because of its great depth and poor water quality.

5.12 Conclusions RQTSE is anticipated to be a very large component of water supply within the Kingdom in coming years. MAR provides strategies for both reclaimed water storage and enhanced water quality through natural subsurface polishing mechanisms. Strategies such as ASTR /ARR offer a potential reduction in social stigma concerns associated with the recycling of wastewater.

With respect to site-specific implementation of MAR, detailed feasibility and hydrogeological analyses must be performed, including local hydrogeological characterization and pilot testing. An approach of step-wise investigation allows a decision to stop or continue with each step, thus minimizing financial risks.

Part of the feasibility process for identifying an appropriate site and approach is to weigh all technical, economic, and socio-regulatory considerations in order to select the most appropriate option. There is no one perfect site for implementation of reclaimed water MAR in the Kingdom. All hydrogeological settings offer some challenges, and trade-offs are a given. For example, at a particular site, providing sufficient assurance that potable supply will be protected may lead to less than optimal RE. However, it is anticipated that with growing supply needs, reclaimed water MAR will soon become an important part of the array of integrated water management options in the Kingdom.

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Water Management Options

With growing water supply needs, reclaimed water MAR can become an important part of the array of integrated water management options in KSA.



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Toze, S., 2004, Reuse of effluent water – benefits and risks. In New Directions for a Diverse Planet, Proceedings of the 4th international Crop Science Congress, 26 Sep – Oct, 2004, Brisbane, Australia, 11 pp.

Toze, S., 2005, Pathogen survival in groundwater: a review of the literature. In Water quality improvements during aquifer storage and recovery. Volume 1: Water quality improvement processes, P. Dillon and S. Toze, (eds.), AWWA Research Foundation Report 91056F, pp. 123-140.

Toze, S., 2006, Water reuse and health risks – real vs. perceived: Desalination, v. 187, p. 41-51.

Toze, S., Bekele, E., Page, D., Sidhu, J., and Schackleton, M., 2010, use of static quantitative microbial risk assessment to determine pathogen risks in an unconfined aquifer used for managed aquifer recharge: Water Research, v. 44, p. 1038-1049.

Williams, J.F., III, and Al Sagaby, I., 1982, Simulated changes in water levels in the Minjur Aquifer, Riyadh Area, Saudi Arabia: Water Studies Series No. 2, Prepared for the Ministry of Agriculture and Water.



Winslow, F.P., and Maliva, R.G., 2010, Reclaimed ASR – Assessment of potential storage zone in the Middle East, Proceedings 7th International Symposium on Managed Aquifer Recharge, Abu Dhabi, October 10-13, 2010, 11 p.

Wintgens, T., Salehi, F., Hochstrat, R., and Melin, T., 2008, Emerging contaminants and treatment options in water recycling for indirect potable reuse: Water Science and Technology, v. 57, n. 1, p. 99-107.

Ying, G.-G., Kookana, R.S., and Dillon, P., 2004, Attenuation of two estrogen compounds in aquifer materials supplemented with sewage effluent: Ground Water Monitoring and Remediation, v. 24, 102-107.

Zuehlke, S., Duennbier, U., Heberer, T., and Fritz, B., 2004, Analysis of endocrine disrupting steroids: investigations of their release into the environment and their behavior during bank filtration: Ground Water Monitoring and Remediation, v. 24, 78-85.

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Chapter 6: Water Quality and Wastewater Disposal Impacts

6.1 Introduction Much of the border of KSA is surrounded by water, with the Red Sea to the west and the Arabian Gulf to the east. With this expanse of shoreline, the Red Sea and Arabian Gulf sustain a variety of uses, including ports and transportation; industry including power production, oil exploration, and petrochemicals; recreation and tourism; fisheries and food; diverse and unique habitat (such as coral reefs and mangroves); water supply for residential and industrial uses; coastal development and land reclamation; and wastewater disposal.

As discussed in previous chapters, freshwater is limited despite this abundance of water, and KSA has been described as the “largest country in the world without a natural, perennial river running to the sea” (Vincent, 2008). In this naturally arid region, the wadis (riverbeds) are usually dry depressions. While they may carry runoff after a rainfall, apart from some regional variations, they often extend for only a short distance. With the exception of areas in the southwest subject to monsoons, most of the country receives less than 200 mm of rainfall per year, and in the interior part of the country several years may pass between rainfall events (Vincent, 2008).

As a result of these dry conditions, demands for potable and other water have been met by relying on groundwater and desalination of seawater, both of which have modified surface and groundwater resources. The water table has dropped and naturally occurring lakes, such as the system of 17 lakes known as the Layla Lakes, have become dry as a result of direct pumping and use of groundwater for irrigation (Vincent, 2008), further limiting the availability of surface water resources. At other locations, such as in Wadi Hanifa, the wadi has been fed by partially treated wastewater discharges (Vincent, 2008). The drawdown of groundwater and discharge of wastewater to wadis has the potential to place the Red Sea, Arabian Gulf, and groundwater resources at risk, as does the discharge of inadequately treated wastewater generated from various water uses.

For these reasons, Chapter 6 focuses on the Red Sea and Arabian Gulf, providing an overview of physical and hydrologic conditions as a context for understanding water quality and the potential for various activities to affect water quality. Within this context, surface water quality is characterized along with documented changes resulting from various uses, including wastewater disposal, desalination, and port activities. Section 6.2 focuses on the Red Sea and Section 6.3 on the Arabian Gulf. Inland, some wastewater is transported to sewage lakes, or large holding lagoons, and an overview of this type of wastewater disposal is presented in Section 6.4. Finally, Section 6.5 provides a summary of how these conditions influence water use management decisions and policy in KSA, while presenting gaps in current policy, planning, and data collection.

CHAPTER 6: WATER QUALITY AND WASTEWATER DISPOSAL IMPACTS

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6.2 Red Sea 6.2.1 Physical and Hydrographic Characteristics Physical Conditions The Red Sea is a long, narrow semi-enclosed water body approximately 438,000 km2 in size. It is about 1,950 km in length. At its widest point, the Red Sea is about 360 km and at its narrowest point about 170 km. At its northern end, the Red Sea forks to form the Gulfs of Suez and Aqaba; it connects with the Mediterranean Sea via the Suez Canal. At its southern end it is linked to the Gulf of Aden through the narrow Strait of Bab el Mandeb, and from there to the Indian Ocean (Figure 6-1).

Water depths vary throughout the Red Sea, with the sea being relatively shallow at its northern and southern ends. The sea has depths as great as 2,000 m in the central section, with a maximum depth of 2,640 m (Gladstone et al. for The Regional Organization for the Conservation of the Environment of the Red Sea and Gulf of Aden [PERSGA], 2006). The sea bed consists of three main levels. The deepest areas are found in a central trough in the south-central regions of the Red Sea.

From the trough, the sea bed rises sharply to a smooth terrace with an average depth of about 600 m in the south to 1,000 m in the north (Drake and Girdler, 1964). From this terrace, the seabed also rises abruptly to the continental shelf, within which the depth is no more than 50 m due to the extensive formation of coral reefs. The continental shelf is generally wider in the southern Red Sea, which is a major factor in determining the types and distribution of shallow water marine habitats, including coral reefs; water depth is also a factor influencing an area’s sensitivity to water quality impacts. Landward, the Red Sea is typically bordered by a coastal strip 40 to 60 km wide, backed by hills or mountains rising as much as 3,000 m in some regions.

Wind, Currents, and Tides Water currents in the Red Sea are generally slow-moving and wind-driven. They are influenced by both Indian Ocean monsoons and daily and seasonal differences in the heating of land and sea (thermosteric effects). Surface water currents move counter-clockwise, with lower-salinity water moving north up the KSA coast of the Red Sea and becoming more saline as it flows to the west and south along the Egyptian and Sudanese coasts. During the summer months, from June through September, currents move south-southeast throughout the main body of the Red Sea. This general pattern varies locally with the shape of the coastline, offshore reef complexes, and eddy effects.

Tidal patterns are semi-diurnal and, as with other characteristics, vary from north to south. When the northern part of the Red Sea is experiencing high water (spring tidal range of 0.6 m), the southern part is experiencing low water (spring tidal range of 0.9 m). In the central part of the sea, in the vicinity of Jeddah, there is no appreciable semi-diurnal tide, although there is a small diurnal variation in water levels.

General Climatic Conditions The Red Sea is a tropical water body and along with the Arabian Gulf, among the warmest of the world’s seas due to the regional climate. At the lowest temperature in February at the Gulf of Suez, mean surface temperatures do not fall below 18°C. At the southern entrance to the Gulf of Suez they are as low as 21°C, and increase to a maximum of 26.5°C about three-quarters of the way from the Gulf of Suez to Bab el Mandeb. The temperatures remain nearly constant through the Bab el Mandeb to the Gulf of Aden. Sea surface temperatures are highest in August and range from a mean of 27°C in the Gulf of Suez to 31.5°C in the southern Red Sea (Gladstone et al. for PERSGA, 2006). Further details on environmental conditions within the Red Sea are provided in Section 6.2.3.


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FIGURE 6-1 Bathymetry of the Red Sea Source: New World Encyclopedia (2011)


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6.2.2 Uses The Red Sea supports a broad range of uses and is well-known for the diversity and quality of its marine environment. It is famous for its coral reefs and marine life, with diverse habitats and ecosystems including sea grass beds, salt-pans, mangroves, coral reefs and salt marshes. These habitats support regionally and internationally significant marine species and the rich fisheries associated with these habitats provide opportunities for fishing, surfing, sailing, and scuba diving; they attract visitors throughout the year for recreational opportunities and tourism and at locations such as Jeddah, are supported by resorts, hotels, and restaurants, contributing to the economic importance of the Red Sea.

The fishing industry associated with the Red Sea is a major source of food in Saudi Arabia and a source of employment, with the industrial fleet based primarily in al Haffah. The artisanal (or traditional) fishing fleet is distributed throughout the Red Sea coast, operating primarily in the Tabuk and Makkah regions (Food and Agriculture Organization of the United Nations [FAO], 2011). The artisanal fleet is estimated as directly involving 15,800 individuals, consisting of primarily fishers (5,114) and laborers (9,477), as well as temporary fishers (753), walking fishers (481), and individuals investing in but no longer practicing fishing (41) (Gladstone et al. for PERSGA, 2006).

The number of boats involved in fishing was estimated in 2004 at 8,952, including 8,795 small, traditional open boats and 157 semi-industrial trawlers (simple trawlers/seiners or multipurpose fishing boats with cabins and simple radio, radar, and navigation equipment).

In addition to traditional fishing, aquaculture plays an increasingly important role in the region and includes shrimp farming (Gladstone et al. for PERSGA, 2006). In 2004, aquaculture production comprised about 11,172 metric tons of the total fish production in Saudi Arabia (freshwater and marine), with about 8,866 metric tons or 80 percent in seawater culture systems (FAO, 2011).

The Red Sea also is important as a route between the Suez Canal and the Gulf of Aden, with high volumes of ship and tanker traffic, supported by ports, as well as oil refining and petrochemical activities in the vicinity of several ports.

In addition, the Red Sea is a significant economic resource as a water supply (following desalination) for potable, industrial, and commercial uses, including agriculture.

6.2.3 Water Quality Overview Water quality can be characterized in terms of the chemical constituents in the water and localized or regional changes in biota that may be a result of water quality changes. Despite the semi-enclosed nature of the Red Sea and coastal development in some adjacent nations, region-wide alteration of the marine environment as a result of land-based activities has not been observed (Gladstone et al. for PERSGA, 2006). The issues that have been identified as of greatest concern throughout the Red Sea are nutrient inputs from agriculture and sewage, pollution from coastal industry and ports, and the physical impacts from coastal construction and land reclamation. More localized effects and concerns in particular countries include potentially contaminated runoff from pesticide use and inputs of chemicals from industry and shipping (Gladstone et al. for PERSGA, 2006). The sections that follow describe background water quality by parameter throughout the Red Sea and, where data are available, activity and location-specific effects to water quality. The need for additional monitoring to further characterize the problems has been frequently identified in the technical literature.

The Red Sea is a significant economic resource for potable water, industrial uses, tourism, recreation, agriculture, and fisheries.


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Salinity The Red Sea is among the most saline of water bodies in direct contact with an ocean (Gladstone et al. for PERSGA, 2006). Salinity is influenced by high evaporation rates, which average 1 to 2 m/year throughout the year and low precipitation rates, which generally do not exceed 10 mm annually. The highest evaporation rates generally occur in the southern Red Sea. As a result of these high evaporation rates, salinity gradually increases to the north, with salinity at Bab al Mandeb averaging 37 percent (37 parts per thousand [ppt]); in the northern Red Sea near the Gulfs of Aqaba and Suez, salinity averages 41 percent. By comparison, salinity levels in the Indian Ocean range from 32 to 37 percent. Other salinity variations are observed based on season and depth, with salinity increasing during the summer months: a 1 percent variation in the northern Red Sea and a 0.5 percent variation in the southern Red Sea. Salinity also generally increases with depth and then levels off, with salinities at depths greater than 200 m being relatively homogeneous at 40.6 percent, except in the vicinity of hot brines, which are heated, metal-rich, highly saline waters found near the floor of the Red Sea. The greatest depth gradients (from the surface to 200 m) are observed in the southern Red Sea as a result of lower salinity inputs from the Gulf of Aden.

The high ambient salinity is close to the physiological limits of some Red Sea biota, such as mangroves, coral, and various marine organisms, including fish and invertebrate. Marine organisms in the Red Sea are typically hypoosmotic relative to the highly saline sea water, and as a result may experience chronic osmo-regulatory stress to maintain internal water balance. As a result, researchers have noted that these organisms are more susceptible to synergistic effects of stress from anthropogenic sources of pollution and changes in water quality than they might be in another environment (Gladstone et al. f or PERSGA, 2006).

Temperature/ Flushing/Salinity At northern end of the Red Sea, water is exchanged between the Red and Mediterranean Seas through the Gulf of Suez and Suez Canal, with the direction of flow dependent on water levels in the Mediterranean Sea. From June to October, the current is generally southward.

At the southern end, water exchange between the Red Sea and Gulf of Aden occurs through the Strait of Bab el Mandeb and is limited by narrow, shallow straits—only 140 m in depth for much of the area. The deepest section is on the western Djiboutian side, but even there the depth is only 290 m. As noted above, tidal variation is low and is negligible just to the north of Bab el Mandeb.

In addition to the width of and depth of Bab el Mandeb, the flow through it is largely influenced by high evaporation rates, monsoon winds, and salinity, with more water flowing into the Red Sea than out. These conditions, defined by sharp differentials in seasonal water temperatures and salinities, also influence the direction of flow between the Red Sea and Gulf of Aden. During the winter months, due largely to the high evaporation rates and absence of river inflows, surface waters which are warmer and of lower salinity flow into the Red Sea from the Gulf of Aden. At the same time deeper waters, which are cooler and of lower salinity, flow out. The inflow of the lower salinity surface freshwater results in a greater salinity gradient in the southern Red Sea than the northern Red Sea. This in turn contributes to the persistent outflow of the cooler, denser, highly saline water from the deeper areas of the southern Red Sea into the Gulf of Aden. During the summer months, the pattern changes with the flow in the surface layer reversed and water from intermediate depths flowing from the Gulf of Aden to the Red Sea.

The semi-enclosed nature of the Red Sea limits its renewal or flushing time, with the renewal time for the entire water body estimated at around 200 years. Above the thermocline, in the

Sensitivity of Biota to Water Quality Changes Biota in the Red Sea are believed to be more susceptible, due to very high salinity levels, to stress from pollution and water quality changes than similar biota in other marine environments.


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upper 200 m of water, the flushing rate is estimated to range from 6 years (Gladstone et al. for PERSGA, 2006; Höpner and Lattemann, 2002) to 10 years (Smeed, 2010) and in the deeper water, flushing rates are estimated to range from 30 to 45 years (Plahn et al., 2002 as cited in PERSGA, 2006) to 70 years (Smeed, 2010). Thus, pollutants discharged to the Red Sea may reside there for an extended period of time before they are flushed out as water from outside sources replaces water in the sea.

Dissolved Oxygen DO concentrations in the Red Sea are affected by temperature, salinity, and water circulation patterns, with the lowest concentrations found in the warmest, highest-salinity waters. DO is at near saturation levels in surface waters throughout most of the Red Sea and the Gulf of Aden and therefore does not indicate widespread water quality impacts. The highest surface water concentrations are generally found in the northern Red Sea due to lower water temperatures and the southern Red Sea as a result of higher primary productivity. DO levels typically are higher in the winter, when temperatures are lower, than in summer.

DO concentrations are saturated to a depth of about 100 m, drop to 10 to 25 percent saturation at depths of 400 to 600 m, then increase to about 20 to 50 percent saturation in the deep water layer. Concentrations remain at saturated levels throughout the Gulf of Suez and decline with depth in the Gulf of Aqaba, but never below 50 percent saturation.

Nutrients Nutrients, in the form of nitrate, phosphate, ammonium, and silicate, are required for the growth of phytoplankton and contribute to overall productivity. In shallow coastal ecosystems, excessive nutrients can increase the growth of epiphytic algae on sea grass and have negative effects on the growth, survival, and reproduction of coral. Overall nutrient trends and patterns are described in this section and in the discussion of productivity below. Localized differences are described in the discussion of pollutant sources and water quality below.

The Red Sea is oligotrophic, with low nutrient inputs throughout most of the sea. Somewhat higher levels of nutrients are measured in small northern areas off of the Sinai Peninsula, transition areas between the Red Sea and Indian Ocean, and in localized areas of enriched conditions which are attributed to anthropogenic inputs of nutrients (Gladstone et al. for PERSGA, 2006). In the southern Red Sea, the higher nutrient concentrations are a result of nutrient-rich water from the Gulf of Aden. In late summer, the inflow of this water and upwellings of nutrients in the Arabian Sea in August and September lead to a 25 percent increase in concentrations relative to the central Red Sea.

Phosphate concentrations follow this general pattern, with a sudden drop in surface water concentration north of 19° N to concentrations below 1.5 mg/m3 (1.5 µg/L; 0.0158 micromoles [µM]) in the northern Red Sea and seasonal variations observed in the Gulf of Aqaba (Sheppard et al., 1992 in Gladstone et al. for PERSGA, 2006) ranging from 0 to 0.25 µM in the summer months of May through November and 0.75 to 1.0 µM in the winter months of December through April, with lower concentrations beyond 3 km of the shore (Badran, 2001, in Gladstone et al. for PERSGA, 2006). Even in highly enriched shoreline areas such as Jeddah receiving anthropogenic inputs of nutrients, nearby open water areas not receiving wastewater discharges were identified as having very low or “nil” levels of total phosphorus (Mohorjy and Khan, 2006). This is in contrast to total phosphorus concentrations along the Jeddah coast measuring as high as 0.74 mg/L (23.89 µM) in an open water area receiving wastewater discharges and 0.92 mg/L (30.25 µM) in an area adjacent to a fish market (Mohorjy and Khan, 2006).

These values indicate a range of trophic conditions in the Red Sea, with the dominant condition being oligotrophic. Based on nutrient scaling carried out by Ignatiades et al., 1992


STRATEGIC STUDY 6-7

(Karydis, 2009), mean phosphate values for similar water bodies were calculated as 0.02 µM in oligotrophic waters, as 0.09 µM in mesotrophic waters, and as 0.34 µM in eutrophic waters.

Nitrate concentrations in surface waters are highest in the southern Red Sea in the vicinity of Bab el Mandeb, with a similar pattern of decreasing concentrations northwards to areas of very low concentrations in the northern Red Sea and Gulf of Suez. Surface water nitrate levels in the Gulf of Aqaba vary seasonally, ranging between 0.05 µM in summer and 0.05 to 0.1 µM in winter (Badran, 2001, in Gladstone et al. for PERSGA, 2006).

In localized areas receiving anthropogenic inputs, however, total nitrate concentrations along the Jeddah coast are as high as 28.3 mg/L (456.4 µM) in an open water area receiving wastewater discharges and 16.5 mg/L (266.1 µM) in an area adjacent to a fish market (Mohorjy and Khan, 2006). Based on nutrient scaling developed by Stefanou et al. (2000), these concentrations are well above the mean value of 0.32 µM nitrate, which is an indication of the threshold between mesotrophic and eutrophic conditions (in Karydis, 2009).

Average silicate concentrations are also at a maximum in the southern Red Sea, with seasonal variations in the Gulf of Aqaba.

Distinct from the north/south variations in nutrient concentrations, nutrient enrichment (late winter to early summer) has been attributed to the regeneration of nutrients from winter plankton blooms in surface waters near Jeddah (Gladstone et al. for PERSGA, 2006).

Productivity Primary productivity is low throughout most of the Red Sea relative to other seas as a result of the thermocline, which for much of the Red Sea limits the recycling of nutrients from deeper water to the photic zone. Nutrient input from rivers also is very low to non-existent, which tends to limit primary productivity overall.

Despite these relatively low levels, variations in primary productivity are observed in the pelagic (open sea) zone seasonally and spatially, with largely oligotrophic levels of productivity observed in the Gulf of Aqaba and Gulf of Suez (annual average of 0.2 to 0.9 and 0.22 grams carbon per square meter per day [g carbon/m2/day ], respectively), oligotrophic to mesotrophic levels in the northern Red Sea (annual average of 0.21 to 0.50 g carbon/m2/day ), and the highest productivity level (annual average of 1.6 g carbon/m2/day) observed in the southern Red Sea and the Gulf of Aden. These higher levels are associated with nutrient-rich waters upwelling from the Gulf of Aden during monsoon season and into the southern Red Sea.

In certain areas, such as the Gulf of Aqaba to the north, destratification occurs during the winter (December to April) when surface water temperatures drop and wind mixing occurs, resulting in higher nutrient levels and higher associated primary productivity in shallow waters. Blooms of harmful algae have also been observed in the vicinity of developed areas experiencing nutrient enrichment (Al-Suwailem, 2011) and in other cases, in response to eutrophication-induced blooms of other algae (Mohamed, Z. et al., 2007).

6.2.4 Pollutant Sources and Overall Water Quality KSA has undergone significant development in the past decades from a state of relative underdevelopment to a modern industrial country, with much of the development occurring in or having an effect on coastal areas. The largest urban centers on the Red Sea coast are Jeddah, Yanbu, Jizan, Al Qunfudhah, Al Lith, and Rabigh (www.Geohive.com, 2011). In addition to these cities on the coast, the largest nearby urban centers that depend on the Red Sea as a water supply include Makkah, Al Taif, and Al Madinah. Between 1974 and 1992, urban populations grew at more than twice the average annual rate of overall population growth, with about 15 percent of the population in the Kingdom living in the Red Sea coastal zone. In more recent years (2004 to 2010), a number of the coastal cities such


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as Jeddah, Yanbu, and Rabigh continued to grow at levels above the country-wide average, with Al Madinah and Makkah at approximately the country-wide average of 3.2 percent growth per year. Associated with this development is the urban infrastructure needed to support the growing population: power and desalination plants, sewage and industrial wastewater treatment plants, and port development with associated refineries and industrial uses.

As part of the Strategic Action Programme for the Red Sea and Gulf of Aden, Country Reports (PERSGA/GEF 2001 as cited in PERSGA, 2006) presenting data on pollutant discharges to the Red Sea from various sources along the coast, were compiled. Data from these reports are presented in Table 6-1. Likely sources of the discharges are described from a land use perspective and supplemented with data from monitoring locations in and around Jeddah, an industrial, commercial, and educational center with tourist resorts and marinas. Sampling stations in areas without direct input of point source discharges and with

TABLE 6-1 Marine Pollution Emissions from Red Sea Coastal Provinces in KSA

Pollutant Sewage Industrial Cities Desalination Refineries Petro-chemicals Total

COD 293,200 2,570 270 296,040

BOD 144,580 1,114 1,543 147,237

Phosphorus 51,580 9 51,589

TSS 1,623 1,623

Suspended Solids 1,071 63 1,134

Nitrogen 29,480 29,480

Ammonia-N 10,000

Total Nitrogen 88 88

Barium 285 285

Copper 345 345

Cadmium 10 10

Chromium 54 54

Chlorine 630 146 100 876

Iron 825 825

Lead 195 195

Manganese 195 195

Nickel 2,909 2,909

Oil 1,164 369 1,533

Phenol 49 49

Phosphorus 3,298 95 2 3,395

Phosphate 3.2 3.2

Sulphides 452 452

Zinc 13,043 13,043

Heat load (cal/yr) 18,250,000 18,250,000

Brine 1.73E+09 1.73E+09

Units are metric tons/year except heat load, which is calories/year Source: From PERSGA/GEF 2001 as cited in PERSGA, 2006 (Table 5.7).


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free exchange of water between the Jeddah coast and the Red Sea generally had water quality conditions similar to background levels. Somewhat higher pH levels at some locations were indicative of relatively higher levels of primary productivity.

Wastewater As described in the discussions of wastewater flows and water reuse and as shown in Table 6-1, treated and untreated wastewater is discharged into the Red Sea and is largely responsible for the magnitude of organic matter as measured by BOD and COD, nutrients, and metals. Although considerable progress is occurring in advancing the expansion of wastewater treatment infrastructure and increasing levels of treatment, fairly recent estimates of nitrogen and phosphorus concentrations immediately adjacent to the Al Khumra WWTP south of Jeddah were from 10 to 100 times greater than normal values for the Red Sea (Gladstone et al. for PERSGA, 2006). Estimated sewage-related pollutant loads by geographic area are shown in Table 6-2. Estimates of untreated sewage by volume or pollutant loading are unavailable. Some discussion regarding untreated sewage is provided in Chapter 8.

Effects such as impairment of marine habitat as a result of accumulated solids, oxygen depletion, and toxic substances that may accumulate in the food chain have been documented in the technical literature. These effects are associated with eutrophication of coastal lagoons, nuisance plant growth disrupting fisheries and recreation, odors, lower transparency, depletion of DO, and high concentrations of hydrogen sulfide and ammonia, the reduced form of nitrogen (Mohorjy and Khan, 2006). More recently, monitoring conducted near the Al Khumra outfall indicated that when discharges occurred in open waters, the associated mixing reduced the impact. Sampling results showed well oxygenated water with low oxygen demands, but high phosphorus concentrations (0.74 mg/L), indicating high eutrophication potential and significant algal growth (Mohorjy and Khan, 2006).

TABLE 6-2 Estimated Red Sea Pollutants Generated by Saudi Arabia’s Municipal Sewage Treatment (metric tons per year)

Town COD BOD P N NH3

Jeddah 92,000 37,000 2,200 8,000

Yanbu 99 39 2 8

Western region, unaccounted fora 100,000 40,000 2,000 8,700 10,000

Northern region, unaccounted fora 66,000 26,000 1,300 5,700

Southern region, unaccounted fora 48,000 19,000 950 4,200

Total 306,099 122,039 6,452 26,608 10,000 a This amount was estimated by per capita production rates from towns where no information was available during the study period. The ‘unaccounted for’ values do not necessarily represent discharges to the Red Sea and do not include the inland cities of Al Taif, Makkah, Al Madinah, Qassim, and Khamis Mushayt. Source: Gladstone et al. for PERSGA, 2006 (Table 5-6).

Desalination Desalination plants discharge chlorine, anti-scaling chemicals, corrosion products, and brine at salinities of 51 ppt, more than 1.3 times the ambient salinity, each with potential effects on the marine environment, and varying in quantity based on the treatment technology. Chlorine, for example, is a biocide that reacts with organic compounds in seawater to produce chlorinated and halogenated by-products. Anti-scaling agents generally have a relatively low toxicity and are diluted rapidly, but limited information is available on their effects in water bodies such as the Red Sea. Copper, which is toxic at high concentrations,



may be bound in sediment and later remobilized, producing longer-term effects. Finally, the brine discharge is at an elevated temperature (over 9°C above ambient

conditions), which may also stress marine biota living at the upper end of their temperature tolerance (Gladstone et al. for PERSGA, 2006).

KSA’s desalinated water supply in 2009 for just its six largest cities is estimated at 2,263,000 m3/day, as previously detailed in Table 1-7, with 1,296,000 m3/day situated along the Red Sea. Facility locations are shown in Figure 1-6. Estimates of the total brine discharge to the Red Sea from all countries range from 6.4 million m3/day in 1996 to 6.8 million m3/day in 2008 (Bashitialshaaer et al., 2011).

Based on a literature review conducted approximately 5 years earlier, desalination-related discharges were not noted as appearing to deleteriously affect the Red Sea environment, although in coastal areas with poor flushing and dilution, desalination was noted as a possible stressor to marine biota (Gladstone et al. for PERSGA, 2006).

Future potential impacts associated with brine discharge to the Red Sea have been estimated for the population bordering the Red Sea in 1950 and 2008, and projected to be present in 2050, using data on desalination plant capacity from 1996 to 2008. From 1996 to 2008, the volume of brine discharges to the Red Sea was estimated to increase by about 6 percent. Based strictly on modeling using a mass balance approach, salinities in the Red Sea would be predicted to increase by 1.16 g/L by the year 2050. The potential for localized impacts was noted as most significant where brine discharges occur (Bashitialshaaer et al., 2011).

However, on a larger scale, salinity levels are expected to be relatively unchanged because of circulation and current patterns, which were not incorporated in the modeling analysis. In particular, the amount of water withdrawn for desalination is small compared to water loss as a result of evaporation. In addition, increases in salinity would be offset by the change in density, which would contribute to density-driven currents. The currents would enhance water exchange with the open ocean, which would contribute lower salinity waters, as described in Section 6.2.3, and moderate the potential effects associated with desalination-related discharges.

Ports Port-related activities also have the potential to affect coastal waters with major ports, including:

• Dibba: the northern-most port on the Red Sea coast of KSA, with passenger ferries, cement exports, and livestock, foodstuffs, and general cargo imports.

• Yanbu: the second largest port on the Red Sea coast of KSA serving the city of Al Madinah, importing grain and cement.

• King Fahd Port: a port 22 km southeast of Yanbu, serving as an important petroleum shipping terminal for crude and refined oil, bulk, and general cargo. In addition to petrochemical industrial uses are other manufacturing plants and light industries.

• Rabigh: a port on an inlet 140 km north of Jeddah handling crude oil and related products from a nearby refinery and undergoing significant expansion.

• Gizan: the southern-most port, with oil exports and general cargo, bulk grain, and livestock imports.

Potential Effect of Desalination in Coastal Areas • Desalination-related

discharges are a potential stressor to marine biota in coastal areas with poor flushing and dilution.

• Potential impacts are most significant at a local level.



The effects of ports have been documented through literature reviews. Significantly higher levels of beach oil have been observed in the northern Red Sea, reflecting its proximity to the significant levels of shipping traffic passing through the Gulf of Suez. From January through November of 2010, almost 16,500 vessels passed through the Suez Canal, of which about 20 percent were petroleum tankers and 5 percent were LNG tankers (Mohorjy and Khan, 2006; EIA, 2011). Although causes of oil in the Red Sea have not been systematically reported or documented in a consistent way that allows the source to be determined, such as loading, unloading, transport, or industrial discharges, potential pollutants associated with shipping activities also include oil ballast water, bilge water, and anti-fouling agents (Gladstone et al. for PERSGA, 2006).

In other locations (the southern Red Sea and Gulf of Aden), possible cause-effect relationships between oil pollution and coral reef health were evaluated and a high potential for oil-related impacts was noted (Mohorjy and Khan, 2006). Water quality impacts have also been observed at Yanbu, where about 70 percent of the treated industrial wastewater from Yanbu’s industrial area is discharged into the Red Sea (Gladstone et al. for PERSGA, 2006), and elevated levels of nutrients were observed.

Other Other activities also have been observed to result in water quality effects. Samples collected at a shoreline location near Jeddah where fish handling and processing result in wastes being dumped into the sea were noted to have high concentrations of BOD, COD, phosphorus, and nitrogen, even though dilution resulted from the discharge being in an area where there is free exchange of water with the Red Sea. The corresponding values for these parameters were 19 mg/L, 352 mg/L, 0.92 mg/L as P, and 16.5 mg/L as NO3 (Mohorjy and Khan, 2006).

Monitoring conducted in small lakes or lagoons not directly connected to the Red Sea by surface waters, but with possible connections through underground pipes, also indicated water quality impacts from adjacent land uses in Jeddah. Three of the four monitored stations near the Red Sea, suspected of receiving waste from the nearby buildings and recreational areas, had low DO levels (4.6 to 4.9 mg/L), indicating pollution by biodegradable organic matter. Chlorides and sulfates were very high at one station. COD was high at another station, as were sulfates. Although the connection to the Red Sea is not direct, the potential was noted for indirect connections through underground pipes or groundwater (Mohorjy and Khan, 2006).

A link between boating (and other recreational activities) and water quality effects also has been documented at a marina and resort location on Obhur Creek in Jeddah. The monitoring locations, characterized as having waste discharging directly to the Red Sea but without free mixing, had elevated COD and phosphorus concentrations. Although pollution levels were not considered to be very high, the potential for additional increases with more intense boating activity exists (Mohorjy and Khan, 2006).

6.3 Arabian Gulf 6.3.1 Physical and Hydrographic Characteristics Physical Conditions The Arabian Gulf is a shallow semi-enclosed sea oriented northwest to southeast, and approximately 239,900 km2 in size. It is about 1,000 km in length and varies in width from 75 to 350 km, with a mean of 240 km. At its northern end, the Arabian Gulf receives freshwater inflows from the Tigris, Euphrates, and Karun Rivers, which join to form the Shatt al Arab. At its southern end, the Arabian Gulf flows to the 56-km wide Strait of Hormuz and from there to the Gulf of Oman and the Arabian Sea (Bashitialshaaer et al., 2011; Hamza and Munawar, 2009). The Arabian Gulf extends from latitudes 240 and 300 N, situated at approximately the same latitudes as Al Madinah and Suez, respectively.



Water depths in the Gulf average about 36 m, with a maximum depth of just over 90 m (Figure 6-2). The shallowest areas, less than 20 m deep, are in the Shatt Al-Arab delta in the northwest, with depths increasing in a gradual trend to the south. A shallow shelf extends along the KSA coast, widening toward the United Arab Emirates (UAE) coast, where the average depth is about 20 m. Mudflats are dominant along the western Gulf coastline, where currents are gentle. The depth increases to about 80 m to the northeast along the Iranian coast. The volume is approximately 8,400 km3 (Bashitialshaaer et al., 2011).

FIGURE 6-2 Bathymetry of the Arabian Gulf Note: Modified from Hamza and Munawar, 2009 Wind, Currents, and Tides Currents and flow patterns in the Gulf are influenced by high evaporation rates, low freshwater inflow, and restricted water exchange with the Arabian Sea. The combination of high evaporation rates and low freshwater inflows results in a net loss of water in the Gulf, with inflows estimated to raise the water levels of the Gulf by 10 to 46 cm and evaporation losses estimated to decrease the water levels by roughly 10 times this amount, or the equivalent of 140 to 500 cm per year (Hamza and Munawar, 2009). This net deficit results in a reverse flow of water from the Gulf of Oman and through the Strait of Hormuz and circulates sea water in a counter-clockwise pattern north along the coasts of Iran and Iraq and then south along the coasts of KSA and the UAE. The current is strongest along the Iranian coast, then decreases toward the northern Gulf, and remains sluggish along KSA and southern coasts. Southward flows are largely wind-driven. This pattern of water inflow and velocity relates closely to salinity, sediment dispersion, sediment deposition, and pollutant transport patterns, as discussed in later subsections (Hamza and Munawar, 2009).

Tidal patterns in the Arabian Gulf are complex and are influenced by tidal currents through the Strait of Hormuz. Throughout much of the Gulf, tides are semi-diurnal (tidal cycle over 12



hours), with fluctuations less than 0.6 m away from the shoreline and increasing to 1 to 2 m near shore. In two nearer-shore areas, off the northern KSA coast and off the UAE coast, the tidal range is zero, with tides rotating around those points.

Temperature and Flushing The air temperatures in the Gulf area vary between 0°C during the winter months and 50°C in the summer, with corresponding water temperatures varying between 10 to 15°C in the winter and 39°C in the summer (Hamza and Munawar, 2009; Barth and Kahn,2008). Within these temperature ranges, water temperature fluctuations are greatest in shallow, near-shore areas, fluctuating as much as 20°C, with somewhat smaller fluctuations between seasons in open water areas. These temperature fluctuations result in a low diversity of marine species, consisting of species that are able to tolerate the temperature extremes ranging from tropical to temperate climates.

Although the Arabian Gulf is semi-enclosed, flushing rates there are much greater than in the Red Sea and measurements of residence time are much lower, ranging from 350 to 500 days (Johns and Olson [1988] cited in Hamza and Munawar, 2009). This difference is largely attributed to flows through the Strait of Hormuz.

6.3.2 Uses As with the Red Sea, the Arabian Gulf supports a diversity of ecological, economic, and social uses. Oil and gas exploration, processing, loading, and transportation are significant industries in the region, encompassing approximately 800 offshore oil and gas platforms and 25 major oil terminals with associated processing and production. The Gulf is a major shipping route for Middle Eastern and South Asian ports and for industries associated with the global transport of oil, with an estimated 20,000 tankers passing through the Strait of Hormuz annually (Sale et al., 2011). Other industrial activities make up a significant component of the economy and include petrochemical, fertilizer, rubber manufacturing, and steel production, to name a few.

Fisheries in the Arabian Gulf represent the most important renewable natural resource, and the second most important resource after oil. Estimates by the FAO place fishery resources in the Gulf (from all Gulf countries) at 550,000 tons annually, although overfishing is an issue (Kardovani 1995, as cited in Sale et al., 2011). Within KSA, fishing occurs at a number of locations along the coast, with the shrimp fleet and industrial landings being centered at Dammam. The 2009 shrimp and prawn catch for KSA was estimated at 11,058 metric tons, with a total fisheries catch estimated at 42,881 metric tons (FAO, Regional Commission for Fisheries [RECOFI]; 2011). Aquaculture plays an important role as well, as discussed previously in Section 6.2.2.

The main ports of landing for the artisanal fleet and the number of artisanal vessels operating out of these ports in 2000 were as summarized in Table 6-3.

As with the Red Sea, the Gulf is a significant economic resource as a water supply for potable use, supporting the capital of Riyadh as well as industrial and commercial uses, including tourism.

TABLE 6-3 Artisanal Ports of Landing in Saudi Arabia (2000)

Landing Site Number of

Artisanal Vessels

Al Frea 125

Al Jubail 387

Safwa 100

Dareen 304

Al Zour 146

Al Qatif 132

Syhat 143

Dammam 176

Al Khobar 135

Other Ports 177

Total 1,825



The Gulf also supports valuable habitat, ranging from extensive intertidal mudflats to sea grass, mangrove, and coral communities, and provides essential habitat and food sources for intertidal macrofauna. Some of these habitats are critical for endangered species such as the green turtle, and serve as nursery grounds for shrimp and other commercially important species such as the pearl oyster. Although the role of different biological communities is still poorly understood, recent ecosystem studies have indicated the presence of a much richer biota than previously believed (Barth and Khan in Abuzinada et al., 2008).

Finally, as highlighted in Chapter 1, the Arabian Gulf is a significant economic resource as a water supply for potable, industrial, and commercial uses, most of which require desalination.

6.3.3 Water Quality Overview Water quality issues that have been identified as of the greatest concern throughout the Arabian Gulf include rapid coastal development, municipal and petrochemical industrial effluents, oil exploration and production, the remaining effects of massive oil releases during the 1991 Gulf War, and marine transport activities. There is some evidence of localized eutrophication where wastewater is inadequately treated, but the most significant water quality and environmental issue identified is oil pollution. The potential risk to water quality and habitat in the Gulf is exacerbated by the semi-enclosed, low-energy nature of the Gulf, which provides conditions that encourage deposition of particulates and associated pollutants.

The need for additional monitoring to further characterize the problems has been identified repeatedly in the technical literature. The sections that follow describe background water quality throughout the Arabian Gulf, and where data are available, activity-and location-specific effects to water quality.

Salinity Inflows from the Gulf of Oman tend to keep the salinity levels in the Arabian Gulf nearly constant over time. Sea water from the Strait of Hormuz enters at a salinity of about 36.5 to 37 ppt and as it circulates to the north, increases in concentration as a result of high evaporation rates to a maximum as high as 42 ppt (Barth et al., 2008). In the northern Gulf, freshwater input from the Shatt al Arab has a diluting influence. The more dense saline water with salinities of approximately 40 ppt sinks in the deeper portions of the Gulf and flows southward in the trough along the Iranian coast, where it exits the Strait of Hormuz as a deepwater current. This outflow of deeper, more saline water combined with the input of lower-salinity water from the Gulf of Oman contributes to the flushing rates described above (Kampf et al., 2005).

Dissolved Oxygen Gulf waters tend to be well-oxygenated as a result of mixing associated with northwest winds. In a study covering most of the Gulf, surface waters had DO concentrations ranging from 4.21 to 5.32 ml/L (Jacob et al., 1995). At depths of 40 m, DO concentrations were measured at greater than 4.1 ml/L.

Nutrients Compared to other seas, the Arabian Gulf has relatively low concentrations of nutrients. Phosphate concentrations decrease rapidly south of Al Khobar and in proximity to shoreline areas, suggesting rapid uptake in photosynthesis by algae and other plants. Concentrations offshore of Dammam have been measured as dropping from 0.03 ug/L to 0.01 ug/L in near-shore areas, and further decreasing to 0.005 ug/L in the Gulf of Salwah (Barth and Khan in Abuzinada et al., 2008).



Silicates, which are important as a structural component of certain diatoms and flagellates (protozoans), are found at high concentrations in the Gulf, with concentrations significantly increasing along the southern KSA shoreline.

Ammonia and suspended solids follow a similar pattern, with concentrations increasing in near-shore areas, and south in the Gulf of Salwah. Nitrate and nitrite concentrations have not been observed to follow a clear spatial distribution.

In general, nutrient concentrations are related to salinity and generally correlate inversely. In the northern Gulf, high nitrate concentrations are inversely related to salinity, suggesting that their origin is land surface drainage to the Shatt Al-Arab River (Al-Yamani, in Abuzinada et al., 2008). Phosphorus, which is present at relatively high concentrations in the Shatt Al-Arab, is usually bound to suspended sediments that are discharged into higher-salinity waters in the Gulf, resulting in an increased concentration of phosphorus.

Although only limited scientific data are available documenting eutrophication, visual observations suggest that problems exist in localized areas (Khan, in Abuzinada et al., 2008). For example, agricultural areas draining to the Shatt al Arab may be the cause of increased benthic algal growth near the discharge to the Gulf, with historical phosphate concentrations in the Shatt al Arab (1988) ranging between 0.18 and 0.70 µg/L, nitrate at 26.21 to 52.39 µg/L and nitrite at 0.53 to 0.70 µg/L. Similarly, nutrient discharges from a methanol/ammonia plant, an oil refinery, a slaughter-house and livestock industry, and WWTPs on the northern coast of Bahrain have been identified as potential causes of dense algal mats. Offshore algal blooms and red tides also have been interpreted as symptoms of eutrophication.

Literature reviews have identified the need for a better understanding of circulation patterns, water exchanges at the Strait of Hormuz, and evaporation rates as a basis for better understanding sediment and pollutant effects in the Gulf and adjoining water bodies.

Productivity Reduced productivity has been attributed to the relatively low nutrient concentrations in the Gulf. However, because of the extent of shallow water areas and relatively high water clarity, the coastal sediments support highly productive habitats of intertidal mud flats, sea grass and algal beds, mangroves, and to a lesser extent, coral reefs. According to one productivity estimate, the shallow water areas are defined as 10 to 12 m deep and have a typical productivity rate nine times that of the water column as a whole (1,820 versus 200 g carbon/m2/yr). These highly productive areas, however, are vulnerable as a result of their proximity to anthropogenic sources of pollution (Barth and Khan in Abuzinada et al., 2008). In other parts of the Gulf, particularly in population centers and near point source discharges, productivity is highly variable and related to nutrient enrichment. In nutrient-enriched areas, the spread of harmful algal blooms also is believed to have been encouraged by the introduction of algal species through ballast discharges from vessels (Sale et al., 2010).

6.3.4 Pollutant Sources and Overall Water Quality Various forms of coastal pollution have reportedly been associated with population increases, related development and infrastructure, development and transport of oil resources, and municipal and industrial wastewater discharges. Among these sources, oil-related pollution, industrial discharges, and desalination discharges are most frequently identified as the greatest existing or potential sources of water quality problems.

The largest urban centers on the Arabian Gulf coast are Dammam and Al Jubail (www.Geohive.com, 2011). Between 2004 and 2010, the population of Jubail grew by more than 11 percent per year and the population of Dammam grew at 3.5 percent per year, both well over the average KSA growth rate of 3.2 percent per year over the 6-year period. Riyadh is another large urban center that is dependent on desalinated water from the Arabian Gulf for its water supply. Riyadh grew at 4.5 percent per year over the same time period.



Wastewater As described in Section 1.4 (the discussions of wastewater flows and water reuse) and shown in Table 6-1 for the Red Sea, treated and untreated wastewater is discharged into the Arabian Gulf and contributes organic matter as measured by BOD and COD, nutrients, and metals. Although considerable progress is occurring in advancing the expansion of wastewater treatment infrastructure and increasing the levels of treatment, there is some evidence of eutrophication in coastal areas where untreated or partially treated sewage is discharged (Khan in Abuzinada et al., 2008). According to previous estimates of untreated wastewater discharges from 1993, discharges from Al Khobar, Al Hasa, and Al Qatif (combined) totaled 40,000 m3/day (Khan in Abuzinada et al., 2008). More recent estimates of untreated or partially treated wastewater discharges were approximated by the difference between the capacity of the wastewater treatment plant and the wastewater flow through the plant. Wastewater flows beyond the capacity of the plant are expected to be untreated or only partially treated at best. Total untreated or partially treated discharges to the Arabian Gulf are estimated at 87,002 m3/day (Table 6-4). This increase relative to previous estimates is attributed to population increases and improved tracking of untreated discharges.

TABLE 6-4 Estimated Wastewater Discharges from Saudi Arabia to the Arabian Gulf

WWTP (Type of Treatment)

Existing Capacity (2009–2010 data)

Amount Treated (m3/day)

Amount Potentially Discharged without Treatment (m3/day)

Dammam (Secondary) 209,000 240,000 31,000

Khoba (Secondary and Tertiary) 193,000 158,000 0

Jarudiyah (Tertiary) 172,000 171,000 0

Safwa (Secondary) 15,000 16,000 1,000

Al Awwamiyah (Primary) 10,000 28,000 18,000

Al Jish (Primary) 9,000 24,000 15,000

Hofuf 1 (Primary) 30,000 45,000 15,000

Hofuf 2 (Secondary and Tertiary) 303,000 180,000 0

Umran (Primary) 19,000 26,000 7,000

Totals 960,000 888,000 87,000 Source: ItalConsult, 2009-2010 Note: Many of the untreated discharges are from plants with only primary treatment (Al Awwamiyah, Al Jish, Hofuf 1, and Umran).

Desalination Plants As described in Section 6.2.3, desalination plants discharge chlorine, anti-scaling chemicals, corrosion products, and brine at salinities nearly 1.3 times that of the ambient salinity. Countries along the Arabian Gulf rely heavily on desalinated water, with a 2009 estimate of 14,451 desalination plants worldwide (Henthorne, 2011) with Saudi Arabia topping the list as the world’s largest producer of desalinated water with 27 desalination plants (SAMIRAD, 2011). Older estimates place capacity in the Arabian Gulf region at 58 percent (Al-Mutaz et al., 1989 in Bashitialshaaer et al., 2011). Water supplied through desalination for Dammam and Riyadh is estimated at 967,000 m3/day (Table 1-7). The 1996 and 2008 total brine discharges to the Arabian Gulf from all countries were estimated at 14 million m3/day and 18.4 million m3/day, respectively (Bashitialshaaer et al., 2011).



As noted above, future potential impacts associated with brine discharge to the Red Sea have been estimated for the population bordering the Red Sea in 1950 and 2008, and projected to be present in 2050. From 1996 to 2008, the volume of brine discharges to the Arabian Gulf was estimated to increase by about 30 percent, or about five times the increase in brine discharge to the Red Sea over that time period. Based on modeling using a mass balance approach, the amount of brine discharged in 2008 is predicted to increase peak salinities in the Arabian Gulf by 0.93 ppt, and result in an increase of 2.24 ppt by the year 2050 (Bashitialshaaer et al., 2011).

As with the Red Sea, the amount of water withdrawn for desalination is very small compared to water loss as a result of evaporation. As a result, increases in salinity are expected to be offset by the lower salinity inflows from the Gulf of Oman, outflows of deeper more saline waters, and freshwater inflows from the Shatt al Arab. The currents would enhance water exchange, and moderate effects associated with desalination-related discharges.

The potential for impacts to marine life are more significant, however, on a local level where brine discharges occur, and include long-term exposure to effluents that are warmer, more saline, and lower in oxygen than ambient waters. Seasonal variations in salinity associated with varying flow regimes through the Strait of Hormuz may also contribute to potentially greater impacts during periods of higher natural salinities.

In areas within the Gulf having naturally higher salinity levels, such as the Gulf of Salwah, many species of corals, mollusks, and echinoderms are absent and lower species abundance is generally observed at salinities above 45 ppt (Lattemann and Höpner in Abuzinada et al., 2008). The effects of other associated discharges, including copper and chlorine, are also potential stressors. There is a need for studies to evaluate the cumulative effects of these constituents with other environmental stressors, including multiple discharges in proximity to each other and increased residence time of pollutants in near-shore areas. In addition, at some locations where salinity levels are locally greater, the efficiency of recovering potable water has decreased, consequently increasing the cost of desalinated water (Bashitialshaaer et al., 2011).

Ports and Other Industries Ports, oil-related exploration and processing, and other industries are considered to be major contributors to pollution levels in the Gulf, with oil pollution identified as the major environmental issue. Pollutant sources include accidental discharges in the form of spillage at oil loading terminals, leakage from shallow wells, intentional oil discharges (as described in the next subsection), ballast water, atmospheric deposition, and industrial discharges. In nutrient-enriched areas, the spread of harmful algal blooms also is believed to have been encouraged by the introduction of algal species through ballast discharges from vessels (Sale et al., 2010). The main source of oil appears to be from spills at terminals and discharge of ballast water from vessels, but other sources, such as the Shatt Al-Arab River, also contribute to the pollutant inputs. Oil pollution has been observed in the form of floating oil, beached oil, and tar balls, with related effects on wildlife and marine biota.

Potential Effects of Desalination • Potential stressor to

marine biota in coastal areas with poor flushing and dilution.

• Potential impacts most significant on a local level where brine discharges occur.

• Decreases in efficiency of recovering potable water, and related cost increases of recovery.

Future Impacts of Desalination • Potential impacts

expected to increase with predicted increase in desalination capacity

Impacts Associated with Petroleum-Related Industry • Oil pollution is and will

be a major water quality and environmental issue.



Although available information suggests that hydrocarbons and heavy metals are not present at significant levels in offshore areas, elevated concentrations are associated with industrial/port complexes and urban centers. Port and industrial complexes in KSA include:

• Al Jubail: The largest industrial complex of its kind in the world, consisting of petrochemical and fertilizer plants, steel works, port operations, extensive support industries, the Royal Saudi Naval Base, and a military air base.

• Dammam: The second largest port after Jeddah and third largest city in KSA after Riyadh and Jeddah. The Dammam-Dhahran-Khobar area is a major hub for shipping, oil, commerce, and industry. The Dammam area is known for a wide variety of recreational facilities.

• Al Khobar: Part of the greater Dammam/Dhahran metropolitan area, it is a commercial and economic center with manufacturing. Port activities have been relocating, with Dammam taking over most commercial shipping activities and oil export occurring at Ras Tanura, leaving more recreational/tourist use of the waterfront.

• Ras Tanura: A port and industrial area south of Al Jubail, with a major oil port and oil operations center for Saudi ARAMCO further out on the peninsula and nearby offshore oil rigs and production facilities.

• Ras Al Khafji: A port on the border of KSA and Kuwait, with oil-related industry.

Port locations are shown in Figure 6-3 and activity-specific pollutant categories are summarized in Table 6-5.

TABLE 6-5 Major Port and Other Industry Pollutant Sources

Pollution Sources Types of Substances and Pollutants

Offshore Sources

Oil transport by tankers and pipelines Oil, bilge cleaning agents, sewage, anti-fouling agents from ship paints

Offshore oil exploration and development Oil, drilling muds containing anti-scalants, anti-fouling agents from ship paints

Natural seepage of oil Oil and gas

Land-Based Sources

Oil exploration and production Oil and gas, drilling muds, heavy metals

Petrochemical industries and refineries Oil combustion products such as polyaromatic hydrocarbons (PAHs),polychlorinated biphenyls (PCBs), COD, and BOD

Spillage at oil-loading terminals Sediments, oil and its combustion products, crank oil

Atmospheric emissions

− From flaring, venting, and purging gases; combustion processes; fugitive gases; particulates from burning sources; pesticides

CO2, CO, methane, VOCs, NOx, SO2, H2S, pesticides, PAHs

− From aeolian transport (wind) of contaminated sediments

Source: Khan in Abuzinada, 2008.



Other In addition to oil discharges associated with oil-related exploration, extraction, and processing, regional wars have resulted in pollution associated with massive oil spills, oil-well fires, and sunken and leaking vessels (Khan, in Abuzinada et al., 2008). During the 1991 Gulf War, an estimate of 1 to 1.7 million metric tons of oil (0.9 to 1.9 million barrels) was released into the marine environment, with the largest release occurring in January 1991, and the majority of the spill reaching the KSA shoreline in January and early February (Jones et al. in Abuzinada et al., 2008). Surveys conducted 10 years later (2002 to 2003) found large volumes of oil trapped under sand and microbial mats. Ecological diversity as measured by various components of the ecosystem was lower in 64 percent of the mangrove habitats, 70 percent of salt marshes, 88 percent of tidal flats, and 90 percent each of sand beaches and rocky shores than in non-oil contaminated shorelines (Jones et al. in Abuzinada, 2008). While recovery is occurring, persistent effects remain.

Other water quality impacts have been attributed to extensive coastal development, including dredging, artificial island construction such as those built near Ras Tanura to allow for easier docking, and shoreline modifications, which have altered (and in some cases destroyed) coastal habitats. In addition to direct water quality effects associated with the dredging and filling activities, these changes modify coastal water movement, sediment transport, and near-shore habitats.

Associated with this coastal development has been the use of shallow coastal areas as repositories for large quantities of solid waste originating primarily from industrial, commercial, and residential sources. The solid waste includes items such as plastics, metal containers, wood, and tires. Because the waste is often placed on the ground close to the Gulf, the lighter debris is often transported along the shoreline by wind and water movements (Regional Organization for the Protection of the Marine Environment [ROPME], 2001).

6.4 Sewage Lakes In areas where growth and development of residential, commercial, and industrial land uses have out-paced the development of centralized wastewater collection facilities and WWTPs, sewage lakes have been created to temporarily store and treat the wastewater. A complete inventory of sewage lakes has not been identified; however, these lakes are known to exist (or have existed) outside of some of the largest population centers such as Jeddah, Riyadh, and Al Khobar. In addition, there are numerous pits located near industrial and oil-producing areas where oily wastes and sludges are stored. The situation in KSA regarding sewage lakes and septage is further discussed in Chapter 8.

In Jeddah, many residential and commercial developments were installed with cesspits because of the lack of centralized wastewater collection facilities. A significant portion of the city, estimated to be 80 percent of the area and 40 percent of the 2.8 million residents (2006 estimate), is unsewered and is served by cesspits. Each cesspit has an open bottom that is typically filled with gravel and is designed to infiltrate wastewater. However, many of these cesspits quickly become clogged with organic material, grease, and debris, and thus require frequently pumping to dispose of the sewage. The high groundwater table in the Jeddah area may also contribute to the lack of success among these types of infiltration systems.

In the mid-1990s, a sewage lake was built about 18 km east of Jeddah by constructing an earthen dam in a wadi and building a receiving area for trucks to dump their sewage to the lake. This area received wastewater from approximately 1,500 to 2,000 tanker trucks per day with an estimated discharge of up to 50,000 m3/day. The lake was never meant to be a permanent solution to the city’s wastewater management needs; however, the lake eventually grew to cover an area of 2.0 to 2.8 km2) with storage of 7 to 9.5 million m3 of water and 0.385 million m3 of organic sediments. Wastewater treatment facilities were



installed near the lake beginning around 2006 to treat the tanker wastewater and the water in the lake (CH2M HILL, 2011).

In May 2010, Custodian of the Two Holy Mosques King Abdullah bin Abdulaziz issued a royal decree ordering that the hazardous Jeddah Sewage Lake be emptied within 1 year. MOWE was tasked with pumping water out of the lake. The NWC, which manages water and wastewater treatment facilities and provides water service in Jeddah, then assumed responsibility for the project. A lake contractor and a planning consultant were hired and the lake was successfully evacuated of sewage by early October 2011. A comprehensive environmental report was prepared for the lake clean-up (CH2M HILL, 2011). One significant environmental impact of the Sewage Lake was groundwater contamination (Buro Happold, 2009). Further details of the clean-up efforts are included in Chapter 8.

As a result of the success of the Jeddah Sewage Lake clean-up, the NWC is also initiating the clean-up of another sewage lake in the Riyadh area known as Al-Nazeem Lake. This effort was initiated in May 2011.

6.5 Gap Analysis The review of information on water quality and wastewater discharges has identified a number of data and information gaps, which are described below.

6.5.1 Monitoring There is a lack of monitoring information for both the Red Sea and the Arabian Gulf. A comprehensive and consistent monitoring program would allow for long-term tracking of the health of these water bodies and changes in water quality as a result of increased development in KSA and the Middle East. In addition, monitoring of localized impacts from desalination brine discharge and wastewater discharges would be useful in further characterizing water quality in the Red Sea and Arabian Gulf.

6.5.2 Pollutant Loading Estimates of major pollutant sources to the Red Sea and Arabian Gulf have been compiled from various publications, although the need remains for an up-to-date, comprehensive inventory which includes mapped locations of water withdrawal intakes, various point source discharges, and sewage lakes. Pre-discharge monitoring reports would be one source of the needed information. Efforts to comprehensively assess these sources of pollution on an ongoing basis would aid in setting priorities for and further determining the need for various management actions to address pollution. Estimates of untreated sewage by volume or pollutant loads would also be useful.

6.5.3 Collaborative Efforts Since several countries are located along both the Red Sea and the Arabian Gulf, it would seem that collaborative efforts to monitor, assess, and manage water quality and pollutant sources to these water bodies should be considered. PERSGA directs its efforts on behalf of designated environments; it is an intergovernmental body dedicated to conservation of the coastal and marine environments of the Red Sea, Gulf of Aqaba, Gulf of Suez, Suez Canal, and Gulf of Aden surrounding the Socotra Archipelago and nearby waters. PERSGA’s member states include: Djibouti, Egypt, Jordan, KSA, Somalia, Sudan, and Yemen. PERSGA has attempted to conduct periodic assessments of water quality and pollutant sources to the Red Sea. However, this effort is not supported by comprehensive monitoring, which is necessary as noted above.

Similar efforts are directed by ROPME for the area bordered by its member states, Bahrain, Iran, Iraq, Kuwait, Oman, Qatar, KSA, and the UAE. ROPME coordinates regional efforts of



the member states to protect water quality, protect the marine environment and coastal areas, and abate pollution. As part of these efforts, ROPME has initiated monitoring, environmental assessment and management activities, and public awareness and training activities. However, as with the Red Sea, monitoring efforts in the Arabian Gulf are not comprehensive.

6.6 Summary The Red Sea and the Arabian Gulf are unique bodies of water that are critical resources for Saudi Arabia and the neighboring countries and regions. They serve as a valuable resource for transportation, fisheries, and water supply (after desalination), and support a variety of industrial activities, most significantly oil and gas exploration and processing. They also provide unique and diverse intertidal and marine habitats attracting tourism and supporting recreational uses.

From a water quality standpoint, consistent documentation of overall degradation of the Red Sea and Arabian Gulf is lacking. To a large extent, this is the result of the size and depth of the Red Sea and Arabian Gulf, the complexity of water and pollutant movements throughout the water column, currents and flows within the water bodies, and flows between connected freshwater and marine water bodies. Contributing to the complexity are variations in local climatic conditions, water uses, adjacent land uses, and differences in mixing and dilution effects based on factors such as shoreline configurations and reef areas.

The Red Sea is not bordered by many populated areas other than Jeddah, nor does it have large watersheds that are continually or seasonally delivering pollutants to the water body. The length and depth of the Red Sea plus the water exchange of more surficial waters on either end make it fairly resilient to pollution effects. Despite these factors, the population continues to grow and water use (shipping, fishing, wastewater and desalination discharges) is broad. While these uses, including improperly treated wastewater discharges, vessel discharges, and other water uses have been demonstrated to have localized effects especially in the Jeddah area, the linkage between these impacts and the ecosystem on a larger scale is not well documented. In addition, despite the size of the Red Sea and water exchange that occurs with adjacent water bodies, pollutants may become entrained in deeper waters with residence times estimated at 200 years.

The Arabian Gulf is shallower and receives significant water inputs only from the Strait of Hormuz and connection to the Gulf of Oman on the southeastern end, and lesser inputs from northern and eastern tributaries; thus it is much more prone to be affected by various activities. There are indications of pollution from improperly treated sewage and industrial sources, the effects of shoreline development, and projections of local effects associated with desalination-related discharges. Of course, the impact of the oil spill in the first Gulf War had a serious impact on coastal wetlands that is just now being cleaned up. The heavy use of this water body for transportation, especially for oil, makes it susceptible to degradation from an accident. Although intensive monitoring has been conducted in selected areas to document the effects of and recovery from oil spills, the relationship between specific pollutant inputs and degradation is not well documented.

The water quality conditions of the Red Sea and the Arabian Gulf do not necessarily demand a solution such as strict restrictions on discharges of TSE—especially if properly treated. However, considering the importance of these water bodies to the region, the scarcity of freshwater resources, groundwater drawdown, sensitivity of the biota, and the significant role water resources play in supporting the economy, there is a pressing need for comprehensive water management. Gaps in water quality data and their relationship to ecosystem health further contribute to the need for sound water management practices, as does the opportunity cost of energy.



A policy of limiting treated wastewater discharges to the Red Sea and the Arabian Gulf for the purposes of comprehensive water management is warranted. While the Red Sea and the Arabian Gulf are not exhibiting significant signs of stress system-wide, localized impacts from untreated or partially treated wastewater are documented, and cumulatively impacts could be felt over time from other agriculture, commerce, and desalination activities as the population of KSA increases. In addition, projected salinity impacts from desalination could support a policy promoting emerging technologies for zero liquid discharge to treat high-salinity wastewater(described further in Chapter 2). Collectively, these policy actions would support reuse goals while maximizing energy investments in treating water. This concept is discussed further in other chapters and the Summary Report.

6.7 References Al-Suwailem, Abdul Aziz, King Fahd University of Petroleum & Minerals. 2011. Communication with CH2M HILL on 17 August, 2011.

Al-Yamani, Faiza. 2008. “Importance of the freshwater influx from the Shatt-Al-Arab River on the Gulf marine environment.” Protecting the Gulf’s Marine Ecosystems from Pollution. Abuzinada, Abdulaziz H., Hans-Jörg Barth, Friedhelm Krupp, Benno Böer, Thabit Z. Al Abdessalaam, editors. Switzerland: Birkhäuser Verlag AG.

Barth, Hans-Jörg and Nuzrat Yar Khan. 2008. “Biogeophysical setting of the Gulf.” Protecting the Gulf’s Marine Ecosystems from Pollution. Abuzinada, Abdulaziz H., Hans-Jörg Barth, Friedhelm Krupp, Benno Böer, Thabit Z. Al Abdessalaam, editors. Switzerland: Birkhäuser Verlag AG.

Bashitialshaar, Raed A.I, Kenneth M. Perrson and Mohammad Aljaradin. 2011. “Estimated Future Salinity in the Arabian Gulf, the Mediterranean Sea and the Red Sea Consequences of Brine Discharge from Desalination.” International Journal of Academic Research. Vol. 3, No. 1, January, p. 133-140.

Buro Happold. 2009. 025935 Wadi Al’asla Remediation Report. Revision 02. November.

Central Department of Statistics and Information, Kingdom of Saudi Arabia, as cited in Geohive. http://www.geohive.com/cntry/saudiarabia.aspx. Population information. Accessed in June 2011.

CH2M HILL. 2011. Jeddah Sewage Lake Evacuation and Sediment Reuse/Disposal Plan. Prepared For the National Water Company – Kingdom of Saudi Arabia. January 2011.

Drake, C.L., Girdler, R.W., 1964. A geophysical study of the Red Sea. The Geophysical Journal of the Royal Astronomical Society. 8 (5), 473–495.

Food and Agriculture Organization of the United Nations (FAO). 2011. Accessed on 3 September2011. http://www.raisaquaculture.net/index.php?id=344).

FAO, Fisheries and Aquaculture Department. http://www.fao.org/fishery/countrysector/FI-CP_SA/en. Information on fisheries. Accessed on 25 May 2011

FAO, Fisheries and Aquaculture Department. http://www.fao.org/docrep/meeting/022/ am422e.pdf Information on fisheries statistics capture status. Accessed on 31 May 2011.

FAO, Fisheries and Aquaculture Department. http://www.fao.org/fi/oldsite/FCP/en/ SAU/body.htm Information on Fisheries Management in the Kingdom of Saudi Arabia, including artisanal and industrial landing locations. Accessed on 25 May 11.

FAO, Fisheries and Aquaculture Department, Regional Commission for Fisheries. http://www.fao.org/figis/servlet/SQServlet?file=/usr/Local/tomcat/FI/5.5.23/figis/webapps/figis

http://www.raisaquaculture.net/index.php?id=344

http://www.fao.org/fishery/countrysector/FI-CP_SA/en

http://www.fao.org/fishery/countrysector/FI-CP_SA/en

http://www.fao.org/docrep/meeting/022/am422e.pdf

http://www.fao.org/docrep/meeting/022/am422e.pdf

http://www.fao.org/fi/oldsite/FCP/en/SAU/body.htm

http://www.fao.org/fi/oldsite/FCP/en/SAU/body.htm

http://www.fao.org/figis/servlet/SQServlet?file=/usr/local/tomcat/FI/5.5.23/figis/webapps/figis/temp/hqp_30204.xml&outtype=html



/temp/hqp_30204.xml&outtype=html. Information on fisheries statistics capture status. Accessed on 4 September 2011.

FAO, Fisheries and Aquaculture Department, Regional Commission for Fisheries, Regional Aquaculture Information System. http://www.raisaquaculture.net/index.php?id=344. Information on aquaculture statistics, Accessed on 3 September 2011.

Hamza, Waleed and Mohiuddin Munawar. “ Protecting and Managing the Arabian Gulf: Past, Present and Future.” Aquatic Ecosystem Health & Management. Vol 12, No. 4, p. 429–439. 2009.

Henthorne, Lisa President, International Desalination Association. http://www.idadesal.org/PDF/the%20current%20state%20of%20desalination%20remarks%20nov%2009%20by%20lisa%20henthorne.pdf. Information on “The Current State of Desalination”. Accessed on 1 September 2009.

Höpner, Thomas and Sabine Lattemann. “Chemical impacts from seawater desalination plants - a case study of the northern Red Sea.” Desalination. Volume 152, pages 133-140. Published by Elsevier. 2002.

ItalConsult Draft Wastewater Reuse Planning Reports prepared for MOWE for each of the 13 Regions:

• Al Baha; February 2010 • Makkah; October 2009 • Al Jouf; July 2009 • Najran; August 2009 • Assir; December 2009 • Northern Borders; June 2009 • Eastern Province; January 2010 • Qaseem; October 2009 • Hail; July 2009 • Riyadh; December 2010 • Jizan; March 2010 • Tabouk; July 2009 • Al Madinah; January 2010

Jacob, P.J. and S. Al-Muzaini. “Marine Plants of the Arabian Gulf and Effects of Oil Pollution.” Mahasagar. Vol. 28, No. 1 and 2, pages 83-101. 1995.

Johns and Olson (1988) as cited in Hamza and Munawar. “ Protecting and Managing the Arabian Gulf: Past, Present and Future.” Aquatic Ecosystem Health & Management. Vol. 12, No. 4, p. 429–439. 2009.

Jones, David Alan, Miles Hayes, Friedhelm Krupp, Gino Sabatini, Iain Watt, and Lee Weishar. 2008. ”The impact of the Gulf War (1990 - 91) oil release upon the intertidal Gulf coast line of Saudi Arabia and subsequent recovery.” Protecting the Gulf’s Marine Ecosystems from Pollution. Abuzinada, Abdulaziz H., Hans-Jörg Barth, Friedhelm Krupp, Benno Böer, Thabit Z. Al Abdessalaam, editors. Switzerland: Birkhäuser Verlag AG.

Kampf, J. and M. Sadrinasab. 2005. The Circulation of the Persian Gulf. Ocean Science Discussion, 2, p. 129-164. Accessed at http://www.ocean-sci-discuss.net/2/129/2005/osd-2-129-2005.html.

Karydis, M. 2009. “Eutrophication Assessment of Coastal Waters Based on Indicators: A Literature Review.” Global NEST Journal. Volume 11, No. 4, p. 373-390.

Khalil, Ahmed S. 2010. “Pressures, status and response to marine and coastal biodiversity in the Red Sea and Gulf of Aden.” Report for the contract to “Compiling data and information for biodiversity outlook report in the Regional Seas, in accordance with the set of indicators developed by MCEB.” June.

Khan, Nuzrat Yar. 2008. “Integrated management of pollution stress in the Gulf.” Protecting the Gulf’s Marine Ecosystems from Pollution. Abuzinada, Abdulaziz H., Hans-Jörg Barth,

http://www.fao.org/figis/servlet/SQServlet?file=/usr/local/tomcat/FI/5.5.23/figis/webapps/figis/temp/hqp_30204.xml&outtype=html

http://www.raisaquaculture.net/index.php?id=344

http://www.idadesal.org/PDF/the%20current%20state%20of%20desalination%20remarks%20nov%2009%20by%20lisa%20henthorne.pdf

http://www.idadesal.org/PDF/the%20current%20state%20of%20desalination%20remarks%20nov%2009%20by%20lisa%20henthorne.pdf

http://www.ocean-sci-discuss.net/2/129/2005/osd-2-129-2005.html

http://www.ocean-sci-discuss.net/2/129/2005/osd-2-129-2005.html



Friedhelm Krupp, Benno Böer, Thabit Z. Al Abdessalaam, editors. Switzerland: Birkhäuser Verlag AG.

Khomayis, H.S. 2002. “The Annual Cycle of Nutrient Salts and Chlorophyll-a in the Coastal Waters of Jeddah, Red Sea.” Journal KAU Marine Science., Volume 13, p. 131-145.

Lattemann, S. and T. Höpner. 2008. “Impacts of Seawater Desalination Plants on the Marine Environment of the Gulf.” Protecting the Gulf’s Marine Ecosystems from Pollution. Abuzinada, Abdulaziz H., Hans-Jörg Barth, Friedhelm Krupp, Benno Böer, Thabit Z. Al Abdessalaam, editors. Switzerland: Birkhäuser Verlag AG.

Mohorjy, Abdullah M. and A. Khan. 2006. “Preliminary Assessment of Water Quality along the Red Sea Coast near Jeddah, Saudi Arabia.” Water International. Vol. 31, No. 1, March. p. 109-115.

Mohamed, Z. and I. Mesaad. 2007. “First report on Noctiluca scintillans blooms in the Red Sea off the coasts of Saudi Arabia: consequences of eutrophication.” Oceanologia, 49 (3), pp. 337–351

New World Encyclopedia. http://www.newworldencyclopedia.org/entry/Red_Sea. Bathymetric map of Red Sea. Accessed in March 2011.

PERSGA (The Regional Organization for the Conservation of the Environment of the Red Sea and Gulf of Aden). 2006. State of the Marine Environment, Report for the Red Sea and Gulf of Aden: 2006. PERSGA, Jeddah. (Prepared by: Gladstone, Dr. William; Facey, Captain Roy; Hariri, Dr. Khaled).

Sale, Peter F., David A. Feary, John A. Burt, Andrew G. Bauman, Geörgenes H. Cavalcante, Kennety G. Drouillard, Björn Kjerfve, Elise Marquis, Charles G. Trick, Paolo.

Usseglio, and Hanneke Van Lavieren. 2011. “The Growing Need for Sustainable Ecological Management of Marine Communities of the Persian Gulf.” Ambio: A Journal of the Human Environment. Vol. 40. 6 October. p. 4-17.

SAMIRAD. http://www.saudinf.com/main/a541.htm Information on desalination capacity in Saudi Arabia from Saudi Arabian Market Information Resource and Directory. Accessed on 1 September 2011.

Smeed, David. “The Circulation of the Red Sea”, a presentation for the workshop Red Sea Research: Past and Present, King Abdullah University of Science and Technology. March 2010. http://krse.kaust.edu.sa/downloads/David%20Smeed_Southampton.pdf Accessed on 22 August 2011.

U.S. Energy Information Administration. http://ei-01.eia.doe.gov/emeu/cabs/ World_Oil_Transit_Chokepoints/Suez.html. Information on shipping traffic. Accessed on 3 June 2011.

Vincent, Peter. 2008. Saudi Arabia: An Environmental Overview. London: Taylor & Francis e-Library.

http://www.newworldencyclopedia.org/entry/Red_Sea

http://www.saudinf.com/main/a541.htm

http://ei-01.eia.doe.gov/emeu/cabs/World_Oil_Transit_Chokepoints/Suez.html

http://ei-01.eia.doe.gov/emeu/cabs/World_Oil_Transit_Chokepoints/Suez.html

http://www.bookrags.com/browse/tf0203030885/

STRATEGIC STUDY

Chapter 7: Regulatory Considerations

7.1 Introduction Current technologies make high-quality purified water from wastewater feasible; regulations are used to ensure that public health and the environment are protected with the application of RQTSE, which can be used both directly and indirectly in a variety of applications, as discussed in preceding chapters. The regulatory framework for reuse should also work to create public trust in the ability of RQTSE to play a major role in water resources management within KSA as demands on existing groundwater and desalinated water supplies increase with a growing population and favorable economic climate for industries.

KSA has recognized its water supply limitations as its population has grown and has begun more defined water resources planning with the National Water Plan in 1985, now updated as the National Water Strategy. Also, in support of the use of reclaimed water, The Council of Leading Islamic Scholars in KSA issued a fatwa in 1978, stating that reclaimed water, if treated sufficiently to ensure good health, is considered pure because the impurities are removed from it during the treatment process. With progress such as KSA’s plan for complete reuse by 2025 (in cities over 5,000 people), the current regulatory framework under the authority of MOWE and MOA is built on the following principles:

• Achieve at least minimum treatment standards. • Maintain an approval and permitting process for the application of RQTSE. • Monitor RQTSE to ensure that it meets the standards. • Maintain enforcement provisions to ensure that RQTSE practices are following

requirements.

This chapter summarizes current regulations, as well as updates proposed by MOWE and PME (Figure 7-1).

FIGURE 7-1 Timeline of KSA Actions to Promote Reuse Varying applications of RQTSE fall under different requirements within the regulations, depending on necessary treatment level and application type, as agricultural needs may differ from those of industries. RQTSE, when adequately treated as described in Chapters 1 and 2 and outlined in the regulations, can offset other potable water demands and decrease

CHAPTER 7: REGULATORY CONSIDERATIONS

7-2 STRATEGIC STUDY

wastewater discharges. These benefits, both environmental and economic, also exist for using biosolids, such as for a soil conditioner and/or nutrient source, rather than disposing of them in landfills, as is currently the most popular disposal choice in KSA. Indirect reuse via groundwater recharge and its regulations and parameters are discussed in Chapter 5.

Regulations and standards are developed by a governing body based on the experience of all parties involved, technical feasibility, public perception and policy, and economics. Worldwide, reuse regulations are geared toward making this resource “pathogen-free.” The World Health Organization (WHO) has set forth minimum treatment guidelines, most recently updated in 2006, which have been used as the basis for regulations worldwide. Typical parameters of concern are noted in Table 7-1 (USEPA, 2004) and summarized by category in Figure 7-2. The use of RQTSE for industrial purposes may require further effluent limits for dissolved solids, ammonia, disinfection byproducts and other specific inorganic and organic constituents.

Considering KSA’s goal to reuse all treated wastewater effluent by 2025, regulations must evolve to protect public health and provide public assurance of safety while at the same time encouraging and incentivizing reuse. Public policy and management decisions will play a large role in determining how successful KSA is in reaching this reuse goal. KSA assumes the responsibility for water resources management and its sustainability through the implementation of appropriate infrastructure, regulations, and public education programs, as outlined in proposed regulations.

FIGURE 7-2 Typical Parameters of Concern for Reuse Applications


STRATEGIC STUDY 7-3

TABLE 7-1 Summary of Water Quality Parameters of Concern for Water Reuse

Parameter Significance for Water Reuse Range in Secondary

Effluents Treatment Goal in Reclaimed

Water

Suspended solids (SS)

Measures of particles. Can be related to microbial contamination. Can interfere with disinfection. Clogging of irrigation systems. Deposition.

5 mg/L - 50 mg/L <5 mg SS/L - 30 mg SS/L

Turbidity 1 NTU - 30 NTU <0.1 NTU - 30 NTU

BOD5 Organic substrate for microbial growth. Can favor bacterial regrowth in distribution systems and microbial fouling.

10 mg/L - 30 mg/L <10 mg BOD/L - 45 mg BOD/L

COD 50 mg/L -150 mg/L

<20 mg COD/L - 90 mg COD/L

TOC 5 mg/L - 20 mg/L <1 mg C/L - 10 mg C/L

Total coliforms

Measure of risk of infection due to potential presence of pathogens. Can favor biofouling in cooling systems.

<10 CFU/100mL -107 CFU/100mL

<1 CFU/100mL - 200 CFU/100mL

Fecal coliform (FC)

<1-106 CFU/100mL

<1 CFU/100mL - 103 CFU/100mL

Helminth eggs <1/L -10/L <0.1/L - 5/L

Viruses <1/L - 100/L <1/50L

Heavy metals Specific elements (Cd, Ni, Hg, Zn, etc.) are toxic to plants and maximum concentration limits exist for irrigation

—

<0.001 mg Hg/L

<0.01 mg Cd/L

<0.1 mg Ni/L -0.02 mg Ni/L

Inorganics High salinity and boron levels (>1 mg/L) are harmful to irrigation — >450 mg TDS/L

Chlorine residual

To prevent bacterial regrowth. Excessive amount of free chlorine (>0.05) can damage some sensitive crops

— 0.5 mg Cl/L - >1 mg Cl/L

Nitrogen Fertilizer for irrigation. Can contribute to algal growth, corrosion (N-NH4) and scale formation (P).

10 mg N/L - 30 mg N/L <1 mg N - 30 mg N/L

Phosphorus 0.1 mg P/L - 30 mg P/L <1 mg P/L - 20 mg P/L

Source: USEPA, 2004

7.2 Current Status of Reuse Regulations Over the past 10 years, KSA has worked to update its regulations to react to growing water demands, choosing to promote RQTSE as part of its goals concerning sustainable development and raising environmental awareness throughout society. Regulatory updates stem from the National Water Strategy, the guiding water use policy in KSA. Updates specific to RQTSE and biosolids applications, both issued in draft form, reflect the growing market for these resources. Updates to and expansions of wastewater treatment and collection systems are necessary. To support a market for RQTSE, public trust must be raised through education programs (as discussed in Chapter 3) and improving monitoring and compliance programs through regulations.


7-4 STRATEGIC STUDY

7.2.1 Treated Sanitary Wastewater and Its Reuse Regulations The first regulation specifically focused on reuse was published in May 2000, “Treated Sanitary Wastewater and Its Reuse Regulations.” Applications requiring secondary or tertiary treatment were specified. However, water quality standards were not listed; instead, the regulation called for the creation of ROI. The first water quality specifications included only BOD5, TSS, and FC. Later, specific but limited ROI were developed and published (Saudi ARAMCO, 2009).

These implementation rules are typically valid for a period of 5 years, were validated in 2005, and updated in 2010, but not yet approved. Further details are in Section 7.3.2.

7.2.2 General Environmental Regulations and Rules for Implementation The “General Environmental Regulations and Rules for Implementation” (GER&R) were adopted in October 2001 and set forth requirements for environmental protection. Under the authority of KSA’s PME, KSA aims to protect the environment and natural resources, conserving and advancing them, prohibiting any act damaging them, and encouraging sustainable development while raising environmental awareness throughout society. The GER&R sets forth rules to protect natural resources with:

• The basis for regulating actions having environmental impacts • Procedures for the coordination of response operations • Pollution control and compliance • Types of environmental violations and associated penalties

7.2.3 MOWE Guidance: Using Treated Water for Irrigation; Controls-Conditions-Offences and Penalties

The GER&R did not specifically address water quality standards for the reuse of RQTSE, groundwater aquifer recharge, or biosolids applications and neither do the current ROI concerning the Reuse Law. In 2006 MOWE published the booklet entitled, “Using Treated Water for Irrigation; Controls-Conditions-Offences and Penalties.” The adoption of these standards was an important step in establishing safe reuse practices and providing for their implementation. Treatment parameters are presented in Tables 1-18 and 1-19 in Chapter 1. The application requirements and restrictions for the use of treated wastewater are defined by two levels of treatment (Figure 7-3), which address areas of concern as follows:

• Restricted irrigation: appropriate for all crop types except vegetables, tuber crops, and plants where treated water comes into direct contact with the fruit, whether eaten fresh or cooked.

• Unrestricted irrigation: appropriate for all crop types without exception. Transformational, extraction, and construction industries subject to at least tertiary treatment

• In addition, RQTSE is suitable for watering animals and birds that are not designated for human consumption.

Private Reuse Practices

Some private entities, such as Saudi ARAMCO, have established their own engineering standards to ensure that public safety is protected as they institute reuse practices. In the case of ARAMCO, the standards follow California Title 22 more closely than KSA rules.


STRATEGIC STUDY 7-5

The current KSA requirements for restricted irrigation meet the WHO recommendation that treated wastewater contain no more than one human intestinal nematode egg per liter. The more stringent unrestricted irrigation requirements also meet the WHO recommendation that references the same helminth egg value, and additionally no more than 2.2 fecal CFU per 100 ml of treated wastewater. In addition, the U.S. State of California’s rules for unrestricted reuse are often cited as benchmarks for unrestricted agricultural reuse requirements. Most of the requirements for unrestricted irrigation are similar to others around the world. For example, the requirements for tertiary treatment and unrestricted irrigation are generally consistent with the California Title 22 rules enforced by the California Department of Public Health (CDPH) for unrestricted reuse. One important difference between California Title 22 and KSA reuse regulations is the inclusion of nitrogen (ammonia and nitrate nitrogen) in KSA regulations for both restricted and unrestricted reuse cases.

Overall, this program is overseen by the MOA, beginning with the application for a license (for restricted application) and following through with a monitoring program. A license must be obtained from the MOA for restricted agricultural use.

Infrastructure and Application Requirements To ensure the separation of potable drinking water infrastructure and wells, regulations include the following:

• TSE cannot be connected to the well networks within farms.

• TSE pipes must be labeled with a separate color or warning bar.

• If an irrigation system uses TSE for irrigation, piping must be labeled: "Warning: Sewage Treatment Irrigation Only."

• Application should be limited to prevent the formation of ponded or marsh areas where flies and other insects could multiply and form nuisance conditions.

There are several additional requirements for restricted irrigation, including:

• Irrigated fields must be more than 50 m from wells and drinking water reservoirs.

• When using spray irrigation, a separation distance of at least 60 m from public places is required and irrigation must be stopped during windy conditions.

Agriculture Agricultural productivity should be enhanced by reuse, not impaired by misapplications. As described in Chapter 1, wastewater reuse for agricultural irrigation is an important option within the MOA’s strategy for maintaining slowly renewable or non-renewable water resources. The primary constituents of concern in treated wastewater for agricultural use are:

• SS, since filtration may be needed, particularly with micro-irrigation systems

FIGURE 7-3 Agricultural Reuse Categories


7-6 STRATEGIC STUDY

• Nutrients, to adjust fertilization amounts and schedules while limiting algal growth

• Salinity, to estimate the leaching fraction and to select appropriate cropping patterns

• Pathogens, with precautionary health actions such as selecting cropping patterns and choosing the appropriate irrigation system

• Metals, since high levels can be toxic to plants

To ensure the most beneficial applications of RQTSE in agriculture, farm soils should be analyzed by an accredited laboratory to evaluate the effects of using RQTSE. These regulations also include safety requirements for workers, meant to protect their health from exposure. Specifically, workers on sites must:

• Use appropriate gloves and shoes to prevent contact with water. • Be vaccinated against cholera, typhoid, and hepatitis type A. • Have annual medical examinations.

Industrial Applications Industrial reuse applications may have requirements that extend beyond regulated parameter limits, to include lower turbidity, dissolved solids, and/or nutrient limitations (depending on the application) compared to those required of unrestricted irrigation. Large-scale industrial users may provide their own treatment. Open communication and coordination are necessary to ensure that RQTSE is a suitable resource for industries.

Biosolids Uses The benefits of biosolids, or sludge, applications to agriculture are discussed in Chapter 1. Given these benefits of providing nutrients and adding soil moisture retention, a market for the reuse of biosolids in agriculture is present in KSA. To promote the protection of public health and the maximum reuse benefits, testing and monitoring of biosolids prior to application are required. Tables 7-2 and 7-3 present current sludge application criteria for KSA. MOWE’s requirements for sludge application are generally consistent with international best practices, as discussed further in Section 7.4.

TABLE 7-2 Maximum Chemical Criteria for Sludge Application in Agriculture

Concentration in Sludge Soil Limit and Load

Parameter Critical Concentration (mg/kg) Accumulation Limit (kg/hectare) Yearly Load (kg/hectare/year)

Pb 840 300 15

Hg 57 17 0.85

As 75 41 2

Zn 7,500 2,800 140

Cd 85 39 1.9

Cr 3,000 3,000 150

Mo 75 - -

Cu 4,300 1,500 75

Ni 420 420 21


STRATEGIC STUDY 7-7

TABLE 7-3 Maximum Biological Criteria for Sludge Application in Agriculture

Constituent Maximum Measurement

Salmonella 3 Number/4 g of Dry Solids

FC Bacteria 1,000 Number/1 g of Dry Solids

Intestinal Worm Eggs (helminth eggs) 1 Number of Eggs/4 g of Dry Solids

If criteria in Tables 7-2 and 7-3 are met, sludge can be applied for agricultural uses without any restrictions. If one or more of these parameters is exceeded, sludge application is limited. In particular, sludge cannot be used in the following applications:

• In the soil during the growth of vegetables or fruit to be harvested

• For 6 months prior to harvesting vegetables or fruits (which are consumed fresh) growing near the application site

• In soils with pH less than 7

Aquifer Recharge Specific aquifer recharge water quality standards are not included in the current regulations; instead, standards would be assessed using a case-by-case approach for each permit.

7.2.4 Compliance, Monitoring, and Enforcement RQTSE A framework of fines and penalties are in place for violations of the requirements. Actions that carry penalties range from SR 1,000 to SR 25,000. The lowest penalties are for violations such as failing to mark the irrigation system with appropriate warning signs or preventing site inspections. The highest fines are for using raw wastewater or sludge in agriculture or placing raw sewage in irrigation canals or drains. However, no specific information on the level of monitoring (which identifies violations) and enforcement action is currently available.

Biosolids Another conservative compliance measure to protect public health is the use of waiting times after application of sludge that does not meet the criteria in Table 7-3. MOWE mandates the following if the sludge exceeds one or more parameters in Table 7-3:

• Grazing or harvesting is prohibited for at least 3 weeks following sludge application.

• Public access to public spaces such as parks is prohibited for at least 9 months following sludge application.

• Harvests from fruit trees are prohibited for 1 month following sludge application.

• Cultivation of vegetables is prohibited for 14 months following sludge application.

• Tuber crops such as potatoes cannot be cultivated for 34 months following sludge application.


7-8 STRATEGIC STUDY

7.3 Proposed Regulations Both MOWE and PME have drafted regulations that would augment the existing GER&R. At the time of this study, there is no defined timetable as to when these draft regulations will be implemented. This section summarizes the proposed regulations that will drive KSA toward achieving its goals of public acceptance of reuse and total reuse of TSE by 2025. The following section presents some interpretations and potential clarifications to the draft regulations that would further support KSA’s goals for reuse. Comparisons to other international regulations are also included to provide context for the provisions in the draft KSA regulations and to generally highlight the progress made by others as they implement their programs.

7.3.1 Draft 2010 Saudi Water Act This summary focuses on the sections of the draft Saudi Water Act that pertain to reuse. Developed by MOWE, the draft rule addresses the following objectives, which all directly or indirectly relate to the promotion of reuse:

• Preserve non-renewable groundwater, considering it part of a strategic reserve.

• Optimize use of desalinated water for domestic and office uses, as RQTSE is not considered suitable for human consumption.

• Restrict agricultural and industrial use of water to surface water and treated wastewater first, followed by renewable groundwater.

• Safeguard health and environmental safety of all water resources and uses.

• Monitor and consider climate change impacts related to water management.

• Promote needed transparency and availability of water information and encourage exchange of information.

The draft 2010 Act would augment the GER&R and give MOWE responsibilities to implement water policies and strategic water storage projects in KSA. The Act also establishes the creation of the Water Regulatory Authority (WRA) while leaving the responsibilities related to desalination with the Electricity and Cogeneration Regulatory Authority (ECRA). The creation of the WRA is an important step in improving organization of the water sector and coordinating monitoring, data sharing, and compliance activities.

Water Management Strategies KSA intends to monitor and consider climate change impacts related to water management. Further, the draft Saudi Water Act implements the following prioritized strategies for use of treated wastewater, in Article (144), in this order:

• Restricted agricultural uses (undergoing at minimum secondary treatment)

• Unrestricted agricultural uses (undergoing at minimum tertiary treatment)

• Irrigation of open green spaces such as sports fields, public spaces, and public parks and gardens

• Irrigation of non-fruit trees, decorative landscaping vegetation, and jungle and forest trees

• Transformational, extraction, and construction industries subject to at least tertiary treatment

• Water for animals and birds that are not designated for human consumption

• Construction vehicles and washing stations

The draft Saudi Water Act promotes integrated water resources management by prioritizing reuse through policy and actions.


STRATEGIC STUDY 7-9

Treatment Standards The PME would hold the responsibility, in coordination with ministries and stakeholders, the development and updating environmental protection standards and criteria along with controls to regulate discharge and disposal.

Enforcement In an effort to monitor and enforce reuse where appropriate, the draft Saudi Water Act Article (145) builds upon the principles and priorities outlined above, stating “No license shall be granted for the use of ground, surface or municipal water for the purposes set forth in Article (144) if such needs may be fulfilled through use of treated wastewater.” The next article also emphasizes the need to increase infrastructure, indicating that if water supply is going to be provided to development, industry, or government, then adequate wastewater infrastructure must also be in place. This statement addresses a major issue in KSA today, as development often proceeds with only water supply infrastructure in place. It also emphasizes the importance of the licensing bodies in sending the message that development cannot proceed as it has in the past with regard to water management. Article (151) goes on to prohibit the use of municipal water for irrigation of public spaces, including landscaping and sports facilities, if a suitable reuse source is available.

The draft Saudi Water Act also places the responsibility for identifying violations with MOWE, giving this ministry inspection rights and the ability to assign fines or imprisonment in more extreme cases. Penalties are outlined in Part 10 of the draft, and while reuse is not explicitly listed, the protection of public health is. The ability to appeal is also documented.

Summary The draft Saudi Water Act lays the groundwork for a change in philosophy toward integrated water resources management, establishing more intergovernmental collaboration and new entities to oversee water policy. Using regulations as a driver for reuse promotion and market creation, the draft Act steps up to a level of requirements previously unseen in KSA by requiring reuse to meet many non-potable water demands, when appropriate and available. This will require significant infrastructure investment, both public and private.

7.3.2 Draft Implementation Regulations: Treated Wastewater and Its Reuse PME issued a draft rule entitled “Implementing Regulations: Treated Wastewater and Its Reuse” based on objectives to maximize the benefits of this water resource, while controlling treated wastewater quality and protecting public health. This version recognizes the valuable uses of RQTSE, including reducing wastewater discharges and managing water supply needs.

This draft rule includes more specific rules for water quality standards and the application of and uses for treated wastewater. “Clear water” is defined as “water having equal or exceeding specific treated wastewater standards or water having quality not less than receiving water.” This definition is not applicable to RQTSE given the second phrase referencing receiving water, which could be misleading to the public, as much wastewater is discharged on the coasts or to dry channels. The phrase “or water having quality not less than receiving water” could be omitted to provide clarification and focus on the water quality standards.

Wastewater Treatment Standards Proposed monitoring requirements at treatment plants are presented in Table 7-4. Records of sampling must be maintained and MOWE reserves the right to sample effluent at any time

The draft Treated Wastewater and Its Reuse Law recognizes both the environmental and economic benefits of reuse and sets forth more specific standards for RQTSE.



for these parameters. As documented in Table 7-2, treatment requirements differ between private and public facilities. Monitoring data records-keeping also differs, with private facilities only having to keep records for 1 year while public utilities must keep some records for 3 years and others for not less than 5 years. The rationale behind these differences is not fully explained.

TABLE 7-4 Proposed Monitoring Requirements for WWTPs

Parameter Private WWTP Requirements Public WWTP Requirements

BOD5 1 per week 2 per week

COD 1 per week 2 per week

TSS 1 per week 2 per week

TDS 1 per week 2 per week

pH 1 per week 2 per week

FC 1 per week 2 per week

NH3-N 1 per week

NO3 1 per week

Gastrointestinal worm eggs 1 per week 2 per week

Heavy metals 1 per week 1 each every 6 months

Secondary and tertiary wastewater treatment standards are similar to current rules, with comparisons presented in Table 7-5. Three metals have been added to the list: lithium, manganese, and mercury. These standards:

• Carry forward the separation of reuse infrastructure and potable water infrastructure from current rules

• Require permission from MOWE for agricultural, irrigation, industrial, aquifer injection, and sludge application uses while requiring a permit from the MOA for irrigation using restricted RQTSE

Agricultural Applications • RQTSE is a valuable resource for irrigation, as described above, and to encourage the

most benefit without impacting soils over time, soil testing is required as part of the draft rule special provisions. This testing of chemical and physical soil characteristics will aid in determining appropriate application parameters. This protects the long-term viability of the soil for agricultural purposes.

• Other measures to protect public health emphasize the separation of RQTSE from other potable water supplies, directly consumable foods such as vegetables, and human contact. These include:

• Open channels carrying RQTSE for irrigation from vegetable fields must be separated by no fewer than 15 m.

• Spray irrigation using RQTSE must occur at least 60 m from vegetable fields and areas accessed by the public.

• Spray irrigation must stop during windstorms.

• Fields irrigated with restricted RQTSE from potable water tanks and wells must be separated by a minimum of 50 m to create a distance barrier and thus limit mixing of these two waters.



TABLE 7-5 Maximum Containment Levels for RQTSE Contaminants in Wastewater Receiving Secondary and Tertiary Treatment Maximum Contaminant Levels

Secondary Treatment Tertiary Treatment

Characteristics Existing Proposed Existing Proposed

Natural Properties

Floating Materials None None None None

Natural Properties

TSS 40 mg/L Same 10 mg/L Same

pH 6-8.4 pH units Same 6-8.4 pH units Same

TDS 2,500 mg/L Same 2,500 mg/L Same

Organic Chemical Properties

BOD5 40 mg/L Same 10 mg/L Same

Turbidity 5.00 NTU Same 5.00 NTU Same

Oils and grease None None None None

Phenol 0.002 mg/L Same 0.002 mg/L Same

Microbial Properties

Number of CF colonies 1,000 colonies/ 100 ml Same 2.2 colonies/ 100 ml

1.2 colonies/ 100 mL

Number of intestinal worm eggs 1 live egg/L 1 live egg/L Same

Chemical Compound Properties

NO3-N (Nitrate-N) 10.0 mg/L Same 10.0 mg/L Same

NH3-N (Ammonia-N) 5.0 mg/L Same 5.0 mg/L Same

Chemical Properties

Al (Aluminum) 5.0 mg/L Same 5.0 mg/L Same

As (Arsenic) 0.1 mg/L Same 0.1 mg/L Same

Be (Beryllium) 0.1 mg/L Same 0.1 mg/L Same

B (Boron) 0.75 mg/L Same 0.75 mg/L Same

Cd (Cadmium) 0.01 mg/L Same 0.01 mg/L Same

Cl2 (Free Chlorine) >0.5 mg/L Same >0.5 mg/L Same

Cr (Chromium) 0.1 mg/L Same 0.1 mg/L Same

Co (Cobalt) 0.05 mg/L Same 0.05 mg/L Same

Cu (Copper) 0.4 mg/L Same 0.4 mg/L Same

F (Fluoride) 1 mg/L Same 1 mg/L Same

Fe (Iron) 5.0 mg/L Same 5.0 mg/L Same

Pb (Lead) 0.1 mg/L Same 0.1 mg/L Same

Mo (Molybdenum) 0.01 mg/L Same 2.5 mg/L 0.01 mg/L

Ni (Nickel) 0.2 mg/L Same 0.2 mg/L Same

Se (Selenium) 0.001 mg/L 0.02 mg/L 0.2 mg/L 0.02 mg/L



TABLE 7-5 Maximum Containment Levels for RQTSE Contaminants in Wastewater Receiving Secondary and Tertiary Treatment Maximum Contaminant Levels

Secondary Treatment Tertiary Treatment

Characteristics Existing Proposed Existing Proposed

V (Vanadium) 0.01 mg/L Same 0.1 mg/L Same

Zn (Zinc) 4.0 mg/L Same 4.0 mg/L Same

Li (Lithium) None 2.5 mg/L 2.5 mg/L Same

Mn (Manganese) None 0.2 mg/L 0.2 mg/L Same

Hg (Mercury) None 0.001 mg/L 0.001 mg/L Same

Source: PME, 2010 (draft Implementing Regulations: Treating Wastewater and its Reuse Law)

Timing is also used as a protection measure in agricultural applications. Use of restricted RQTSE for irrigation must cease 1 week prior to harvest of fruits and field crops.

Some exceptions to the parameters listed in the above tables may occur. For example, if the RQTSE exceeds TDS concentration, dilution may be performed or if the crops are known to be TDS-resistant, the RQTSE may be used as is. If restricted RQTSE exceeds the criterion for gastrointestinal worm eggs (1 egg/L), application could still occur if “proper precautions were adopted for the protection of workers and consumers.” However, the draft does not appear to define what these proper precautions are, which may lead to confusion or misapplication.

Biosolids Applications With permission from the MOA and appropriate soil analysis, the application of sludge should benefit agricultural lands. As with the existing regulations, both chemical and biological parameters must be tested for compliance prior to sludge application. To further protect public health, time is used as a distancing mechanism: a lag time is proposed between sludge application and use of the public place of application or agricultural uses. The criteria discussed below are proposed.

This draft rule is based on the existing chemical and biological criteria for sludge application, adding selenium (Se) to the list. The maximum concentration in sludge is 100 mg/kg, with a soil bearing capacity accumulative limit of 100 kg/hectare and an annual limit of 5 kg/hectare/year. In addition, the biological criterion for the presence of FC is lowered ten-fold to 100 colonies per 1 g of dry substance from 1,000 colonies.

Municipal Applications The draft rules exercise caution by requiring tertiary treatment (unrestricted) when the potential for human contact exists while allowing secondary treatment of RQTSE to meet other irrigation demands. This includes the beneficial use of RQTSE for irrigation of public spaces, including public gardens, parks, and playgrounds. Another stipulation is that irrigation can occur only when the public is not present. Further, spray irrigation must not occur within 60 m of areas of public activity. This restriction could be difficult to implement and enforce, causing hesitation by potential users. One solution would be to install timers on irrigation equipment so that irrigation occurs during off-peak use hours. Other municipal applications present opportunities to manage demands, including street flushing and fire fighting.

Where human contact is less likely, secondary treatment would be sufficient for RQTSE applied to street medians and other areas.



Industrial Applications While the MOA has the authority to grant permission for industrial uses of RQTSE, the Ministry of Commerce and Industry has the authority to establish water quality requirements for specific industrial applications. One limitation is that RQTSE must not be used in food industries.

Aquifer Recharge Applications The MOA also could grant permission for the injection of treated wastewater into aquifers. Chapter 5 describes how standards could be established on a project-specific basis during project permitting, without existing or proposed water quality standards specifically for groundwater recharge projects. Two approaches to public health could be taken: (1) RQTSE could be treated to tertiary treatment levels so that it poses no public health hazard even if it were to be consumed unintentionally or (2) the MAR system could be designed with assurance of little risk that the water could enter a potable water supply.

Enforcement MOWE and the MOA have rights to monitor and test TSE at treatment facilities and at application sites, respectively. If violations are identified, appropriate penalties would be assessed according to the proposed regulations. Fines up to 50,000 SR are proposed, with the highest fines proposed for the mishandling of raw wastewater and endangerment of public health. Procedures to remedy the effects of violations are also listed.

7.3.3 Summary of Proposed Regulations The two sets of draft regulations are complementary. Specifically, the draft Saudi Water Act signals the policy direction for future integrated water resources management and the promotion of reuse in KSA, while the PME draft stipulates details regarding environmental and public health protection.

The proposed rules also offer flexibility for future improvements, as requirements to reconsider the regulations every 5 years are included. This offers a known timetable for revisions which could reflect improved technologies and best practices, or changes in monitoring and enforcement protocols for example.

7.4 International Best Management Practices Reuse is a key component of water management strategies in many parts of the world, especially arid regions. Freshwater availability is extremely limited and desalination is very energy-intensive. Supporting reuse maximizes the return on this upfront energy investment. While reuse of all treated wastewater is the goal of KSA, this is not a feasible policy in other parts of world where wastewater effluent is used to augment instream flows in receiving streams. Other countries have a somewhat more comprehensive approach to water resources management, placing greater value on aquatic ecosystems and habitat and balancing aquatic ecosystem instream flow needs with those of growing populations. In KSA, where wadis are more common than flowing waterways (as discussed in Chapter 6), instream minimum flows requirements are not as practical as in other, less arid areas. However, the starting point for any water reuse project for any application is ensuring public health and safety.

Recent publications provide some overviews of municipal wastewater reuse applications around the world (USEPA, 2004; Bixio et al., 2008). Selected highlights and key measures used in other regulations with proven success in supporting reuse as a resource are discussed in this section. Most differentiate between unrestricted and restricted uses. For



the most part, KSA’s regulations are consistent with those in other countries. Overall, the focus is to achieve pathogen-free treated wastewater.

A summary of select guidelines and mandatory standards for reclaimed water use in a variety of U.S. states and other countries and regions is presented in Table 7-6. Some minor differences are apparent; for example, some measure FC, while others measure total coliforms. The use of total coliforms is more restrictive than using FC alone, without necessarily being a more expensive testing method. Most also measure other indicators of sufficient treatment, such as filtering or otherwise removing suspended particles that could serve as bacteria substrates: BOD5 and turbidity or TSS. It is also useful to measure chlorine residuals as evidence of disinfection.

7.4.1 The World Health Organization The WHO first developed wastewater reuse guidance for agriculture and aquaculture in 1973. The most recent update, driven by the increasing value of reuse considering the growing global population with limited water resources and concern about public health, was published in 2006. The WHO has always strived to balance standard recommendations with the economic costs of treatment, believing that if rules are too stringent and costly, they may be ignored―creating greater risk to public health.

The countries that have adopted the WHO recommendations as the basis for their agricultural reuse standards use both FC and helminth eggs as pathogen indicators, at 1,000 CFU/100 ml and 1 helminth egg/L, respectively, for unrestricted irrigation. The WHO recommends more stringent standards for the irrigation of public lawns than for the irrigation of crops eaten raw (FC count at 200 FC/100 ml, in addition to the helminth egg standard). In the absence of recommendations for particulate matter, these standards use TSS at concentrations varying between 10 and 30 mg/L.

The WHO recommends stabilization ponds, or an equivalent technology, to treat wastewater. The guidelines are based on the conclusion that the main health risks associated with reuse in developing countries are associated with helminthic diseases; therefore, a high degree of helminth removal is necessary for the safe use of wastewater in agriculture and aquaculture. Intestinal nematodes serve as indicator organisms for all of the large settleable pathogens. The guidelines indicate that other pathogens of interest apparently become nonviable in long-retention-time pond systems, implying that all helminth eggs and protozoan cysts will be removed to the same extent. The helminth egg guidelines are intended to provide a design standard, not an effluent testing standard. The original 1973 WHO recommendations were more stringent than the 1989 recommendations. With respect to FC, the standard increased from 100 FC/100 ml to 1,000 FC/100 ml. The WHO guidelines have had further revision.

A draft guideline proposed by Bahri and Brissaud (2002) recommended extensive revisions in the WHO guidelines, making them somewhat more restrictive, while maintaining the objective of affordability for developing countries. For example, in the draft guidelines, the helminth egg concentration limit is reduced from the current guideline of 1 egg/L to 1 egg/10 L for unrestricted irrigation. The proposed draft guidelines also cover various options for health protection.

WHO Approach to Protecting Public Health

• Identify health risks and determine risk-based standards

• Use treatment and application measures to minimize exposure to health risks

• Establish monitoring and system assessment procedures

• Define oversight responsibilities


CHAPTER_7_FINAL_16SEP 7-15

TABLE 7-6 International Examples of Reuse Standards

Country/Region

Fecal Coliforms

(CFU/100mI)

Total Coliforms

(CFU/100mI)

Helminth eggs (#/L)

BOD5 (ppm)

Turbidity (NTU)

TSS (ppm)

DO (%of Saturation) pH

Chlorine residual (ppm)

Australia (New South Wales) <1 <2150 — >20 <2 — — — —

California (USA) — 2.2 — — 2 — — — —

Cyprus 50 — — 10 — 10 — — —

France <1,000 — <1 — — — — — —

Germany (g) 100 (g) 500 (g) — 20 (g) 1-2 (m) 30 80-120 6-9 —

Israel — 2.2 (50%) 12 (80%)

— 15 — 15 0.5 — 0.5

Kuwait (Crops not eaten raw) — 10,000 — 10 — 10 — — 1

Kuwait (Crops eaten raw) 100 10 10 1

Oman 11A a <200 — — 15 — 15 — 6-9 —

Oman 11B a <1,000 20 30 6-9

South Africa 0(g) — — — — — — — —

Tunisia — — <1 30 30 7 6.5-8.5 —

UAE — <100 — <10 — <10 — — —

USEPA(g) 14 for any sample, 0 for

90%

— — 10 2 — — 6-9 1

WHO (lawn irrigation) 200 (g) — — — — — — — —

1,000 (m)

Note: (g) signifies that the standard is a guideline and (m) signifies that the standard is a mandatory regulation a Two categories of reuse rules are in place in Oman, based on application limitations common in many countries. Source: Adapted from USEPA, 2004



7.4.2 United States The United States is currently the world’s leader in the quantity of RQTSE generated and used. MAR is also employed in areas of the U.S. where the geology is suitable for this more indirect reuse technology. The leading national regulating body is the USEPA. However, reuse regulations were first developed in the state of California, rules commonly known as “Title 22” (California Department of Public Health, 2009). These regulations were the first to discuss unrestricted reuse and are very cautious in their approach. A proven track record has been established through monitoring and the protection of public health over time, making Title 22 a “benchmark” of sorts as other unrestricted systems are compared against it (Bixio et al., 2008). Many other states have implemented rules similar to those of California.

MAR requirements are often determined with a case-by-case approval process including public input (with hearings required in California) so that site-specific characteristics such as geology and public health risks can be taken into account.

California also distinguishes between two levels of secondary treatment, using total coliforms as the standard:

• Disinfected secondary-2.2 recycled water: total coliform count that does not exceed 2.2/100 mL over the last 7 days for which analyses have been completed, and 23/100 mL in more than one sample in any 30-day period.

• Disinfected secondary-23 recycled water: total coliform count that does not exceed 23/100 mL over the last 7 days for which analyses have been completed, and 240/100 mL in more than one sample in any 30-day period.

Tertiary treatment requirements include filtration to an average turbidity of 2 NTU and disinfection by one of the following:

• Chlorine with a contact time (CT) of not less than 450 mg-minutes/L at all times with a modal CT of at least 90 minutes.

• A disinfection process that, when combined with the filtration process, has been demonstrated to inactive and/or remove 99.999 percent of the plaque forming units of F-specific bacteriophage MS2, or polio virus in the wastewater. A virus that is at least as resistant to disinfection as polio virus may be used for purposes of the demonstration.

In addition, the total coliform standard for tertiary treatment is the same as for disinfected secondary-2.2 recycled water, plus no sample may exceed 240/100 ml.

Application limitations for each of these categories are listed in Table 7-7. One noteworthy difference is the allowance of undisinfected wastewater reuse for certain applications where there is little risk of human contact or consumption, such as for orchards where the water will not come into contact with fruit. This flexibility is permissible in tandem with California’s monitoring and enforcement programs so that assurances of public health protection are maintained.

California also specifies requirements in Article 3 of Title 22 for other reuse applications such as in fountains, impoundments, toilet flushing, and snow making, among others.

Other specifications in California’s rules are similar to those of other countries, limiting risk of human contact or consumption with the following:



TABLE 7-7 California Reuse Application Rules by Treatment Category Disinfected tertiary recycled water

(1) Food crops, including all edible root crops, where the recycled water comes into contact with the edible portion of the crop,

(2) Parks and playgrounds,

(3) School yards,

(4) Residential landscaping,

(5) Unrestricted access golf courses, and

(6) Any other irrigation use not specified in this section and not prohibited by other sections of the California Code of Regulations.

At least disinfected secondary-2.2 recycled water

(1) surface irrigation of food crops where the edible portion is produced above ground and not contacted by the recycled water

At least disinfected secondary-23 recycled water

(1) Cemeteries,

(2) Freeway landscaping,

(3) Restricted access golf courses,

(4) Ornamental nursery stock and sod farms where access by the general public is not restricted,

(5) Pasture for animals producing milk for human consumption, and

At least disinfected secondary-23 recycled water

(6) Any nonedible vegetation where access is controlled so that the irrigated area cannot be used as if it were part of a park, playground or school yard

At least undisinfected secondary recycled water

(1) Orchards where the recycled water does not come into contact with the edible portion of the crop,

(2) Vineyards where the recycled water does not come into contact with the edible portion of the crop,

(3) Non food-bearing trees (Christmas tree farms are included in this category provided no irrigation with recycled water occurs for a period of 14 days prior to harvesting or allowing access by the general public),

(4) Fodder and fiber crops and pasture for animals not producing milk for human consumption,

(5) Seed crops not eaten by humans,

(6) Food crops that must undergo commercial pathogen-destroying processing before being consumed by humans, and

(7) Ornamental nursery stock and sod farms provided no irrigation with recycled water occurs for a period of 14 days prior to harvesting, retail sale, or allowing access by the general public.

Source: California Department of Public Health, 2009

One way to reduce public health risk is to create separation between RQTSE applications and potable water sources such as wells. California’s rules are not as restrictive of those in KSA (50-m distance); specifically:

• No irrigation with disinfected tertiary recycled water shall take place within 50 feet of any domestic water supply, with few listed exceptions.



• No impoundment of disinfected tertiary recycled water shall occur within 100 feet of any domestic water supply well.

• No irrigation with, or impoundment of, disinfected secondary-2.2 or disinfected secondary-23 recycled water shall take place within 100 feet of any domestic water supply well.

• No irrigation with, or impoundment of, undisinfected secondary recycled water shall take place within 150 feet of any domestic water supply well.

• Any irrigation runoff shall be confined to the recycled water use area, unless the runoff does not pose a public health threat and is authorized by the regulatory agency.

• Spray, mist, or runoff shall not enter dwellings, designated outdoor eating areas, or food handling facilities.

• Drinking water fountains shall be protected against contact with recycled water spray, mist, or runoff.

• No spray irrigation of any recycled water, other than disinfected tertiary recycled water, shall take place within 100 feet of a residence or a place where public exposure could be similar to that of a park, playground, or school yard.

• All use areas where recycled water is used that are accessible to the public shall be posted with signs that are visible to the public that include the following wording: "RECYCLED WATER - DO NOT DRINK.”

7.4.3 European Union In a collaborative effort among the member countries of the EU, a Water Framework Directive was developed as guiding policy for sustainable water management strategies. As the EU is still working to include reuse as a more recognizable tool in the toolbox of water demand management and environmental protection, policy and regulations have been evolving. The EU has taken a more flexible approach to regulations by identifying Best Practices to achieve environmental and public health related parameters (Bixio et al., 2008).

7.4.4 Australia In many areas of Australia, freshwater resources are scarce. The country has also been plagued by recent droughts and has increased its stormwater capture and reuse programs to address water shortages. Australia, through its National Water Initiative, has also heavily invested in research regarding topics such as household reuse and aquifer recharge, created plumping standards for reuse water in toilet flushing and irrigation, and supported public education campaigns. Indirect potable reuse is gaining acceptance in Australia (Figure 7-4).

National guidelines are published (NRMMC et al. 2009), and water quality standards regarding RQTSE address the following typical uses:

• Recycled water for drinking • Irrigation of human food • Aquaculture • Irrigation of pasture and stock watering

FIGURE 7-4 Potable Water Augmentation Source: NRMMC et al., 2009



• Industrial purposes, including cooling towers • Dust suppression at construction sites and fire fighting • Dual reticulation for garden watering • Toilet flushing and washing machine.

When these standards were developed, considerations included the following questions:

• What are the chemicals of concern?

• What are the acceptably safe levels of human exposure to these chemicals during approved uses of recycled water?

• What are the best methods to reduce or remove these contaminants from source waters?

• What is the efficacy of specific recycled water treatment technologies in reducing each of the contaminants?

• What are the most practical means for monitoring these contaminants in finished water?

This scientific risk-based process is similar to that discussed in the draft 2010 Saudi Water Act, which stresses collaboration and data collection. The guidance documents developed by Australia could be used as a framework for how the proposed Saudi WRA would function and share information.

Australia has also recognized the value of aquifer recharge in replenishing groundwater resources and preventing saltwater intrusion, both of which are issues in KSA, and has gone a step further to plan for drinking water supply augmentation. Although fatwas issued in KSA have stated that RQTSE could be considered suitable for potable use, it is not yet recommended due to public health concerns. KSA must continue its considerable efforts with wastewater treatment and reuse infrastructure establishment before public trust will reach the point where indirect potable uses can be considered.

7.4.5 Singapore Singapore, with its NEWater progam, has been supplying reuse water meeting drinking water requirements since 2003. With its small island size, Singapore has limited water supply and has a longer history of employing reuse to meet its demands. To meet growing demand, Singapore invested in advanced treatment technologies, including reverse osmosis and UV disinfection, that came online in 2003 and instituted a larger public outreach program. Indirect potable reuse is part of the program, with NEWater being discharged to reservoirs. Singapore has recognized economic benefits of its program as well, finding that NEWater production is approximately half the cost of desalination (USEPA, 2004). Further discussion of the public education component is provided in Chapter 3.

7.4.6 Biosolids As with RQTSE standards, the requirements for land application of sludge reflect international Best Practices for agricultural land application, as defined in rules by the EU and USEPA. In fact, many of KSA’s requirements are identical to the standards set forth in USEPA’s 40 CFR Part 503, Sewage Sludge Regulations. During development of its sewage sludge rules, USEPA, in turn, took into consideration similar standards adopted by countries of the EU.



7.5 Implementation Recommendations Treatment technologies for reclaimed water should be tailored to the intended end uses, ranging from agricultural to industrial and urban applications, and quality required to support those uses. Current and proposed regulations differentiate between applications that do and do not directly result in human consumption or contact. Increasing and further establishing the market and availability of RQTSE involves:

• Continued improvements in coordination between various agencies and the private sector

• Implementation of key components of the draft 2010 regulations

• Monitoring of existing reuse examples in various use sectors and promoting those results to increase public trust in this valuable resource

Further detail regarding each of these focus areas is provided below.

7.5.1 Coordination among Various Agencies and Private Sector As privatization and public-private partnerships increase to meet the growing demands for water, wastewater, and reuse infrastructure, coordination and collaboration are necessary for successfully achieving KSA’s goals for environmental protection and integrated water resources management. Infrastructure planning must incorporate reuse treatment technologies and infrastructure as appropriate. The National Water Strategy is being updated, and should include this approach.

The private sector also has a vested interest in coordination and collaboration efforts with public agencies regarding sustainable water resources management strategies. NWC itself is part of the public/private sector cooperation and support strategy for KSA. An integration strategy between public and private sectors should be developed within the framework of The National Water Strategy and include ways to:

• Promote implementation of appropriate technologies to ensure the appropriate quality of RQTSE is available for industries and other end users.

• Create market opportunities for reuse by pairing of RQTSE producers and potential users.

• Share research and monitoring data and collaborate on research efforts.

To create market opportunities for reuse, it will be important to match the producers of the RQTSE with end users as systems are expanded or constructed such that appropriate technologies are used to meet the end users’ needs. Technology options are described in detail in Chapter 2. Location is a critical part of the needs analysis, as centralized and decentralized systems have different benefits. These factors should be considered as part of each region’s economic development strategies.

The sharing of information, both data monitoring and research, is also important. One means of collaboration is a country-wide database which could be created to house and organize reuse data and its potential availability, maintained by MOWE or another appropriate government entity. One possibility is the creation of a Water Data Center. This collaboration would help to maximize infrastructure investments through further promotion of reclaimed water use. Both public and private entities should be contributing information to the Water Data Center. These efforts are emphasized in the draft Saudi Water Act.



7.5.2 Regulatory Efforts KSA should act on the proposed rules so that industries and agriculture are clear on KSA’s priorities and intent of integrated water resources management and reuse goals. These proposed rules, with increased emphasis on sustainability, monitoring, and data collaboration, discussed further below, will further strengthen the understanding of the existing water resources, water quality issues, and opportunities for reuse.

While the current regulations do list many of the recommendations listed below, including monitoring and enforcement rules, limited data are available concerning government monitoring, oversight, and enforcement. Therefore it is difficult to determine if standards are being met and if they are widely understood. The current rules are sufficient to adequately protect public health; however, transparency and data collection are necessary to ensure the public that these regulations are being followed.

This section includes a collection of recommendations regarding regulatory efforts in KSA. Regulatory influence reaches beyond treatment standards for application and to include pricing of water and other ways to encourage reuse, such as through building construction standards.

Agriculture and Other Irrigation Applications The proposed public contact rules in the draft PME regulations seem overly cautious or unclear compared to other international regulations and could discourage reuse. The WHO recommends proper boots, and for those handling produce, gloves (WHO, 2006). Clarification regarding public contact is needed to ensure an applicant’s potential users understand how to meet the intention of the regulations. For example, restricted irrigation may still be used if the gastrointestinal worm egg criterion is exceeded if proper precautions are used [Article N (15)], but the precautions are not defined. Monitoring mechanisms to track this level of flexibility within the regulations, which would be important to maintaining public health, are not currently in place.

Managed Aquifer Recharge Currently, regulations specific to MAR are not in place. While permits are required, the establishment of straight-forward water quality regulations for MAR would reduce uncertainty regarding this application, as would further monitoring, as discussed in the following subsection. The draft Saudi Water Act includes a provision for the injection of RQTSE that has received tertiary treatment into aquifers; however, it is “so long as such water is surplus to the water uses and needs” as defined in the Act. Another approach would be to have more flexibility in regulations such that project-specific requirements can be implemented on a case-by-case basis. Both have benefits, with one having the benefit of consistent, coherent regulations upfront so that proper planning can be conducted. The other option allows for flexibility, with regulations developed on a project-by-project basis, which may create economic savings for treatment. Any planning process for MAR includes risk assessment, identifying the likelihood of pathogens entering potable water. Both could achieve public acceptance with education efforts.

Pricing of Water The draft Saudi Water Act also discusses the use of pricing to manage water demands against depletion of water resources, especially limited freshwater resources. Using market principles through the use of tariffs and fees to promote water conservation would further promote and establish a market for reuse while helping to manage the investments in water, wastewater, and reuse infrastructure currently underway in KSA. Further discussion of market principles is provided in Chapter 4.



Construction Codes and Standards Another way to promote sustainable water use through regulatory efforts is with improvements in construction codes and standards. Such improvements that promote rational use of water, as discussed in the draft Saudi Water Act, should also incorporate the promotion of reuse infrastructure in structures. The current draft Saudi Water Act does not explicitly include reuse infrastructure as a way to improve water efficiency; simple revisions could achieve this.

7.5.3 Monitoring Public and Private Facilities The draft PME regulations include some differing monitoring requirements for private and public facilities, though the reason is unclear. The reason may be economics, as rules may not intend to be overly expensive or burdensome for private facilities. However, as privatization occurs and public-private partnerships increase, it is unclear if over time less monitoring and record-keeping would occur. Options include (1) differentiating the monitoring requirements by size of facility so as to not burden smaller facilities or (2) establishing consistent rules. One solution may be to first follow the more frequent monitoring requirements, and then allow a reduced monitoring schedule as data results show evidence of consistent compliance with the standards.

Key Parameters Most monitoring requirements do not produce instantaneous results, leaving doubt about when the end users and general public would know if there is a public health concern with the application of RQTSE. More directly, implementation of RQTSE testing requirements that are more instantaneous would increase assurance that public health is not at risk with the application of RQTSE. The USEPA recommends this approach so that results are available before it is too late to take corrective action (USEPA, 2004). For example, the WHO defines three types of monitoring: validation, operational monitoring, and verification (Table 7-7). Improving operational monitoring requirements and reporting would improve transparency and trust in KSA’s ability to protect public health.

TABLE 7-7 Definitions of Monitoring Functions Monitoring Type Definition

Validation Testing When a new system is developed, or new processes are added, the treatment system and its individual components should undergo validation testing to prove that they are capable of meeting the specified targets (e.g. microbial reduction targets).

Operational Monitoring

Operational monitoring involves conducting a planned sequence of observations or measurements of control parameters to assess whether a health protection measure is operating within design specifications (e.g. for turbidity). Emphasis is given to monitoring parameters that can be measured quickly and easily and that can indicate if a process is functioning properly. Operational monitoring data should help managers make corrections that can prevent hazardous conditions (break-throughs).

Verification Methods, procedures, tests, and other evaluations, in addition to those used in operational monitoring, are applied to determine compliance with the system design parameters and/or whether the system meets specified requirements (e.g. microbial water quality testing for E. coli or helminth eggs, microbial or chemical analysis of irrigated crops).

Source: WHO, 2006



One potential operational monitoring measure is the use of CT as an assurance that biological treatment minimum criteria have been met. The use of chlorine for disinfection appears to be the method of choice at treatment facilities in KSA. The actual testing method for microbiological criteria is slower, and often application of RQTSE could have occurred before test results are available. However, the current criteria are appropriate, and the results (when available) do provide more detailed data than the chlorine CT method. There are several benefits of this approach:

• The monitoring method can identify any treatment problems that have occurred quickly. • The method allows time for action if necessary. • The effort using an on-line chlorine analyzer is relatively inexpensive. • It is reliable, as evidenced by its common use in potable drinking water projects.

For example, the State of California requires a minimum chlorine CT of 450 mg x min/L for unrestricted reuse projects that use chlorine disinfection to meet biological criteria to protect public health.

Another instantaneous monitoring method is the measure of turbidity. Organic particles provide substrate for microbial growth and can limit the effectiveness of disinfection. Turbidity should be less than 5 NTU. If the turbidity maximum criterion is exceeded, then it is likely that adequate treatment was not achieved. As with the use of chlorine CT, turbidity monitoring is inexpensive and a reliable test that could be used to screen RQTSE before it is distributed from a treatment facility to its end user.

Monitoring of these two parameters, chlorine CT and/or turbidity, could be used as surrogates to improve the timeliness of monitoring RQTSE before its distribution to users. Other countries have instituted similar approaches to instantaneous monitoring.

Groundwater Storage Systems Another ongoing monitoring effort, of groundwater storage systems, should be continued and increased as appropriate. A track record detailing how ARR systems function and how groundwater moves needs to be established to increase public trust regarding indirect reuse. Again, this information needs to be compiled in such a way as to be publicly available through the establishment of the Water Data Center or another entity so that researchers and the end users of this reuse process have access to the data. Fostering a mindset of collaboration among public and private entities will further support investment in and use of groundwater storage systems in KSA.

7.5.4 Reporting Collecting and making available this monitoring and enforcement information will improve public trust of reclaimed water. The draft Saudi Water Act initiates the formation of a WRA and Water Data Center, and emphasizes water research, monitoring, and the sharing and accessibility of water data. This is a very positive step forward in the process of creating synergies among public and private efforts to understand water demands, improve wastewater treatment, promote reuse, and improve management of water resources overall in KSA. Creation of a database is being considered by MOWE, as discussed during the 2011 Gulf Environment Forum (Al-Saud, 2011). Improving the availability of monitoring data and research information will further generate public trust in KSA’s ability to treat wastewater and promote reuse.

To further disseminate monitoring data to increase public trust of RQTSE, reporting methods aimed toward industrial users would demonstrate to this user group the ability to consistently achieve treatment to specific water quality parameters of concern. Annual reports, such as those required for potable water utilities in the U.S., are one way to show an established track record of compliance over time. They could also be used to share progress toward



KSA’s total reuse by 2025 goal. Other methods to share information with the public are discussed in Chapter 3 and could be encouraged or required through regulations. This would further enhance KSA’s message of stewardship of water resources.

7.5.5 Enforcement While procedures are established for monitoring and enforcement to ensure that rules are being followed, this information is not readily available or publicized. It is unclear how often MOWE and the MOA conduct monitoring, and this information could improve transparency in the process and promote increased trust in the quality of RQTSE. The draft PME regulations appear to clarify potential penalties, with higher penalties if public health is put at risk. This further strengthens the message that KSA is committed to improving infrastructure and treatment throughout the Kingdom.

7.6 Summary A framework for compliance, monitoring, and enforcement procedures is drafted and, in some cases, in place. Implementing the draft regulations and promoting consistency in regulatory decision-making benefits the reuse market by:

• Reducing uncertainty for municipalities, industries, and other water customers

• Encouraging planning with sufficient technologies and monitoring requirements

• Promoting technological advancements through data sharing and collaboration between public and private entities

• Establishing appropriate and sufficient pricing for this water resource as part of an integrated, sustainable water resources plan for KSA

• Promoting responsibility for the protection of public health and safety via clear regulations, monitoring, and enforcement.

• Recognizing that achieving goals of national food security and total reuse go hand in hand, helping to sustainably meet agricultural irrigation demands.

Consistency in regulatory decision-making aids in the market development for reuse, as those responsible for infrastructure investment can properly plan for sufficient treatment technologies and monitoring requirements and assess sufficient pricing for this resource. The selection of appropriate and cost-effective technologies could be aided by improved data sharing and collaboration, whether through the creation of a Water Data Center or other method.

Market pricing for water will aid in the comparison of the use of reclaimed water as a resource versus the use of other sources and fully value the investment made in desalination. In Chapter 4, information was summarized showing that the energy investment in water reclamation is several orders of magnitude less than many desalination technologies.

Understanding the regulatory responsibility for public health protection will foster generation of trust among the population as will the proven ability, over time as evidenced by monitoring, of KSA to provide wastewater treatment and safe reuse water. This will be accomplished by consistent and transparent monitoring and enforcement and increased frequency.

Finally, achieving goals of national food security and total reuse go hand in hand. Irrigation using reuse is one piece of the puzzle needed for sustainable water resources management, as agriculture is currently KSA’s largest water user by sector. An integrated water strategy is



necessary to determine whether this is a reasonable goal within the context of current projected water and energy demands from other users.

7.7 References Al-Saud, Mohammed. The Importance of Developing Sustainable Water Resources in the Kingdom – Strategies for the Future. Presentation at the 2011 Gulf Environment Forum, Jeddah, KSA. 31 May 2011.

Bixio, D and C. Thoeye, T. Wintgens, A. Ravazzini, V. Miska, M. Muston, H. Chikurel, A. Aharoni, D. Joksimovic, T. Melin. 2008. Water reclamation and reuse: implementation and management issues. Desalination 218 (2008) 13-23.

California Department of Public Health. 2009. Regulations Related to Recycled Water. From Titles 17 and 22 of the California Code of Regulations.

Kingdom of Saudi Arabia - Ministry of Water and Electricity. 2010. Draft Saudi Water Act.

Kingdom of Saudi Arabia - Ministry of Water and Electricity. 2006. Using Treated Water for Irrigation: Controls-Conditions-Offences and Penalties.

Kingdom of Saudi Arabia – Presidency of Meteorology and Environment. 2010. Draft Implementing Regulations: Treated Wastewater and Its Reuse Law.

Kingdom of Saudi Arabia – Presidency of Meteorology and Environment. 2001. General Environmental Regulations and Rules for Implementation.

Natural Resource Management Ministerial Council, Environment Protection and Heritage Council, and National Health and Medical Research Council. July 2009. Australian Guidelines for Water Recycling: Managed Aquifer Recharge. National Water Quality Management Strategy Document No. 24.

Saudi ARAMCO. 2009. “Water Reuse Regulations in Saudi Arabia” presented at Water Arabia, March 2009.

U.S. Environmental Protection Agency (USEPA). September 2010. Guidelines for Water Reuse. USEPA report EPA/625/R-04/108. Washington, DC.

U.S. Environmental Protection Agency (USEPA). 2004. A Plain English Guide to the EPA Part 503 Biosolids Rule. Washington, DC.

World Health Organization. 2006. Guidelines for the Safe Use of Wastewater, Excreta and Greywater in Agriculture and Aquaculture, Volumes 1 and 2.

STRATEGIC STUDY

Chapter 8: Septage Handling and Treatment

8.1 Introduction 8.1.1 Septage Overview In the context of KSA, the term septage has a number of meanings. Septage is material pumped from septic tanks or, more typically in Saudi Arabia, “cesspits” that were installed for individual residences, groups of residences, or combinations of residential and commercial property. Cesspits or “soak pits” generally consist of a concrete tank (of about 20 m3) with no bottom and walls with holes and are designed as infiltration wells for wastewater (SAFEGE, 2006). Cesspits often lose effectiveness over time, becoming clogged with debris and grease.

From a quality characteristic standpoint, septage typically has significant levels of grease, grit, hair, and other debris. It is typically more concentrated than other types of wastewater. Data on the quality of septage are not readily available. In Jeddah, it was reported that septage BOD was similar in strength to wastewater in typical sewers and a BOD5 of 700 mg/L was assumed. A study in Jordan focused on small community systems that provided the following average wastewater concentrations for septage:

• BOD5 – 1,850 mg/L • COD – 7,350 mg/L • TSS – 3,240 mg/L • TKN – 332 mg/L

These values indicate that while septage in some areas may be similar to typical wastewater, as noted above for Jeddah, some septage in the Middle East may be considerably more concentrated since the cesspits concentrate waste.

For purposes of this chapter, the term septage is broadly described as wastewater that is not centrally collected and pumped/trucked for disposal.

8.1.2 Objectives The objectives of this section are to:

• Describe the primary issues associated with septage handling and treatment that arise from lack of adequate wastewater collection and treatment facilities.

• Use available data to assess the magnitude of the current problem.

• Present alternatives that can provide better management of the situation.

Better management of the current septage handling and treatment issues would mainly provide temporary alternatives while large investments in wastewater collection and treatment facilities are underway. Also, better management of septage and other wastewater not connected to a collection system would aid in the effort to improve public

CHAPTER 8: SEPTAGE HANDLING AND TREATMENT

8-2 STRATEGIC STUDY

perception and trust of the Kingdom’s ability to manage its wastewater management efforts. Overall, this could further support the reuse goals of MOWE and NWC.

8.1.3 Lessons Learned from the Jeddah Situation A large portion of the Kingdom, especially major cities like Riyadh and Jeddah, have significant areas that are not connected to wastewater treatment facilities by sewage collection facilities. Residential and commercial development, and sometimes even industrial development, has occurred but remains dependent on onsite wastewater disposal systems and/or storage tanks, which require regular pumping and disposal elsewhere. This practice causes many problems throughout the Kingdom, including polluting groundwater, as well as posing a potential public health risk associated with pathogens and vectors (primarily rodents and insects) for pathogens, nuisance odors, traffic, and even potential flooding problems in larger municipalities.

In Jeddah, it was estimated in 2005 that only 20 percent of the area of the municipality and 40 percent of the population was served by the wastewater collection systems. Non-sewered portions of the municipality have developed using cesspits or soak pits, as described above. The functionality of these tanks in Jeddah is also limited because elevated groundwater levels in the municipality limit infiltration. Elevated groundwater has been identified as a contributing factor to recent flooding in the municipality of Jeddah, and the historical wastewater disposal practices may be contributing to these elevated groundwater levels. An estimated wastewater balance (Figure 8-1) for the Jeddah area in 2005 shows a potential daily contribution to groundwater recharge of almost 300,000 m3/d (SAFEGE, 2006). It is important to note that the NWC is making aggressive investments in wastewater collection and treatment infrastructure to quickly address this issue in Jeddah, as discussed in Chapter 1.

FIGURE 8-1 Estimated Wastewater Balance for Jeddah in 2005 Highlighting Lack of Wastewater Collection System (Based on SAFEGE, 2006)

A major septage hauling business has developed throughout the Kingdom to haul septage to the WWTPs, to sewage lagoons, and to other unknown disposal areas. In Jeddah, the 2005


STRATEGIC STUDY 8-3

estimate was that 55,000 m3/d was hauled either to the WWTPs or a surface lagoon equaling in excess of 3,600 tanker trips per day, assuming tanker truck capacity of 15 m3. In 2011, it is estimated that 60,000 m3/d is trucked to the Airport-1 WWTP, 15,000 to 20,000 m3/d is trucked to the Briman WWTP at the former lake, and about 40,000 m3/day is trucked to the Al Khurmah WWTP (personal communication with NWC, 2011). Apparently, and based on informal discussions with NWC staff, larger tanker trucks are now being used, on average 20 m3. This would mean the average number of trips has grown to as many as 6,000 per day in 2011.

The sewage lagoon noted in the wastewater balance is the Jeddah Sewage Lake (Lake), which had been referred to as “Misk” or “Musk” Lake. This lake was created by building an earthen dam along the upper portion of the Wadi Al Mari (upstream of Wadi Al Asla) in the 1990s to temporarily store and dispose of raw wastewater from the growing Municipality of Jeddah (see Figure 8-2). Tanker trucks (Figure 8-3) discharged wastewater at the dump station, sometimes at rates up to 50,000 m3/d. The Lake was never meant to be a permanent solution to the City’s wastewater management needs; however, the Lake eventually grew to cover an area of 2.0 to 2.8 square kilometers (km2) with storage of 7 to 9.5 million m3 of water and 0.385 million m3 of organic sediments. The dam was progressively raised as the Lake grew in size.

FIGURE 8-2 Location of Jeddah Sewage Lake Relative to Municipality of Jeddah

Significant efforts continued for many years to provide treatment for the lake water and then to provide an alternative to the discharge of wastewater into the Lake. As part of this effort, the NWC is making an investment of approximately $3 billion US (11.25 billion SAR) in sewer infrastructure and WWTPs that are under construction to eliminate the hauling and storage of raw wastewater in the wadis. By the end of January 2010, sufficient sewage treatment capacity was in place at the Briman WWTP, located near the Lake, to discontinue


8-4 STRATEGIC STUDY

the discharge of raw wastewater to the Lake. However, it was several months after that time before active lake evacuation efforts began.

FIGURE 8-3 Trucks in Line and Dumping Wastewater Near Jeddah Sewage Lake

In late 2009, a strong storm occurred over Jeddah and the foothill areas immediately east of the City, with precipitation totals from a recorded 70 mm at the King Abdulaziz International Airport (KAIA) to 140 mm estimated in the foothill areas. This storm caused significant flooding and loss of life. It also focused media attention on the Sewage Lake because there was significant concern that the Lake would breach and dump sewage into the already saturated and flooded portion of east Jeddah.

In May 2010, Custodian of the Two Holy Mosques King Abdullah bin Abdulaziz issued a royal decree ordering that the hazardous Sewage Lake be emptied within 1 year. MOWE was tasked with pumping water out of the Lake. The NWC, which manages water and wastewater treatment facilities and provides water service in Jeddah, then assumed responsibility for the project. In June and July, the NWC Board of Directors approved a contract for the Lake Contractor to evacuate and clean up the Lake within 11 months and a planning contractor to assist in directing the effort.

As of 5 October 2010, the Lake had been essentially emptied (to the Briman WWTP, evaporation ponds at the Lake, and the Airport-1 WWTP (see Figure 8-4). Evaluations were conducted on flooding, lake sediment, lake area water use and agricultural activities, and ecological resources, and a plan was agreed upon for sediment clean-up and flood management. Additional characterization of the lake sediments was conducted in October and December 2010 to confirm conclusions based on earlier results and to provide more comprehensive data for the West Lake. During this period, the Lake Contractor was mixing dried sediments in place with mineral soils and was ditching areas of the Lake to facilitate further sediment drying (CH2M Olayan, 2011a).

A wide range of treatment alternatives was considered for lake sediments, including options for sediment mixing and removal from the dry lake bed, sediment treatment and processing, and sediment transport and end use. All of the sediment characterization data indicated that the Main Lake sediments are safe for agricultural use, supporting an approach whereby the sediments would be cleaned up in place. Most of the data for the West Lake samples also indicated that the sediments are safe for agricultural use, so that an approach similar to clean-up in place could be considered. However, the presence of elevated levels of TPH and specific SVOCs exceeding recommended levels for residential and industrial sites in some of the sediment samples indicated the need to verify that the sediments were safe prior to returning the site to the municipality (CH2M Olayan, 2011a).


STRATEGIC STUDY 8-5

The lake sediment clean-up was delayed because of the occurrence of additional storms in December 2010 and January and February 2011 that partially refilled the Lake. Sediment clean-up activities were resumed in March 2011 and the clean-up was completed in June 2011. The recommended plan included final sampling on a grid across the former lake bed to do a final check on the safety of the sediments. The Site Release Sampling has indicated a very thorough clean-up of the site. No results showed values exceeding the MOWE (2006) criteria for agricultural use of sludge or USEPA “no risk” criteria for land application of biosolids. Some elevated TPH were detected in 3 of the 205 cells of the grid, so additional mixing of that area to promote volatilization of semi-volatile hydrocarbons was conducted (CH2M Olayan, 2011b). Figure 8-5 shows photos of the former Jeddah Sewage Lake site after clean-up activities.

The well-publicized “hazardous” Jeddah Sewage Lake, the wastewater disposal situation in Jeddah, and the problems associated with flooding in Jeddah all serve to highlight the issues associated with septage and inadequate wastewater disposal in the Kingdom. This problem is addressed in the regional plans developed for MOWE with all areas adopting a goal of having all towns of 5,000 people and greater being 100 percent served by WWTPs with collection systems by 2025. However, there is a lack of a comprehensive assessment of this problem and how it can be addressed consistent with an approach to promote recycled water usage.

FIGURE 8-5 Views of Former Jeddah Sewage Lake in July 2011. Left is photo of main lake area with the earthen dam along the right hand side of the picture. Right is photo of the upper main lake where vegetation has established and a herd of camels is grazing.

FIGURE 8-4 Views of the Jeddah Sewage Lake on 25 July 2010 When Evacuation Effort had been Underway 2 Weeks and on 5 October 2010


8-6 STRATEGIC STUDY

8.2 Current Status of Septage Handling and Treatment 8.2.1 Current Methods for Handling and Transporting Septage As presented in the previous discussion of the situation in Jeddah and the Jeddah Sewage Lake, areas that are not served by wastewater collection systems and WWTPs are typically served by onsite wastewater systems. A survey of systems in the Kingdom has not been conducted, but the cesspits previously described for the Jeddah area are considered typical. In rural areas and small communities, these systems may provide adequate treatment; however, there is always a potential to contaminate precious groundwater in these areas, which smaller communities are likely to rely on.

Trucks are used extensively for hauling sewage (Figure 8-6) as well as for hauling potable water and for transporting RQTSE, used primarily for irrigation purposes. Trucks used for these various purposes have different colors, with orange/yellow trucks transporting wastewater, green trucks for RQTSE, and white trucks for potable water.

While the Jeddah Sewage Lake has received a great deal of publicity, sewage lakes or lagoons are fairly common throughout the Middle East. Al-Nazeem Sewage Lake is a site east of Riyadh that has been used to receive septage waste as well as industrial waste via tanker trucks over the last 20 years. The area surrounding the Al-Nazeem Sewage Lake is generally industrialized and has extremely heavy truck traffic. Quarries, backfill material, cement/concrete batch plants, and contractor yards are in the general vicinity. NWC has built a truck unloading station near the lake for the domestic waste. Now, those trucks have their waste tested prior to being introduced into the sewage network for NWC treatment facilities. This project removed 1,000 to 1,500 trucks a day from discharging into the lake since the beginning of 2011. This has resulted in a natural shrinking of the lake and by late July 2011, the water from the lake had completely evaporated.

An inventory of sewage lakes has not been conducted, but potential locations can be readily identified through examination of urban and industrial areas via Google Earth or other aerial photography. Of course, some of the surface lagoons that are informally identified through this visual approach may not be septage and may be primarily industrial or oily sludge wastes.

The wastewater hauling business consists of private contractors that are typically hired by the businesses requiring their cesspits to be emptied. There is very little apparent regulation of this business and the trucks may be hauling a wide range of domestic, commercial, and/or industrial wastes. The NWC conducts screening of trucks coming to their WWTPs to ensure that the waste is suitable. These screening tests primarily consist of pH and specific conductivity. Table 8-1 lists the criteria used by NWC to accept or turn trucks away from their WWTPs, which primarily treat domestic and commercial wastewater.

FIGURE 8-6 Septage Handling Options


STRATEGIC STUDY 8-7

If a truck is turned away, the driver often does not have an alternative location for disposal of the wastewater. Figure 8-7 is a photograph of a truck that was turned away from the Briman WWTP near the Jeddah Sewage Lake and is dumping the wastewater into an area along the road. The driver pretended that the truck was broken down so its wastewater could be dumped. The Al-Nazeem Lake near Riyadh was receiving 1,500 to 2,000 tanker trucks of wastewater per day until NWC built a receiving station near the lake in late 2010. However, this station does not receive tankers that carry industrial waste, so 100 to 150 tankers per day continued to dump wastewater to the Lake.

The NWC was requested to clean up the Lake in March 2011, and an industrial treatment facility had to be identified in May for the tankers; otherwise, they would have had no place to dispose of the wastewater. Sludge characterization and clean-up are continuing.

As discussed in these examples, while some improvements and WWTP infrastructure additions have led to decreased dumping into lakes, adequate treatment for industrial waste continues to be an issue.

FIGURE 8-7 Wastewater Truck that had been Turned Away from WWTP Dumping Wastewater along Roadside

MOWE has drafted rules to improve and establish wastewater treatment parameters and recycled water standards. Within these not-yet-implemented rules, these trucking practices are acknowledged. The trucks must have sealed, non-leaking tanks and the wastewater they carry may be tested at any time by MOWE. Penalties are identified for illegal dumping and leaking on roadways, but there is little information available regarding enforcement of these rules.

8.1.4 Septage Treatment Needs Without sufficient wastewater infrastructure to treat all wastewater generated, especially in urban areas, a significant amount of wastewater lacks treatment. In this chapter, all of this wastewater is referred to as septage because it is often pumped from malfunctioning cesspits as described previously. To develop an estimate of how much septage lacks treatment, data in Chapter 1―including the recent census population and established WWTP capacities―were used (ItalConsult, 2009-2010; CDSI, 2010). It is assumed that 80 percent of calculated water demand will be returned as wastewater. Estimates of 2010 wastewater flows, wastewater capacity, and untreated septage are presented in Table 8-2.

TABLE 8-1 Criteria for Evaluating Acceptability of Trucked Wastewater at NWC Facilities

Parameter Acceptance Criteria

pH Between 6 and 8

Specific Conductance <2,500 micromhos per centimeter (µhmos/cm)


8-8 STRATEGIC STUDY

TABLE 8-2 2010 Untreated Wastewater Flows in KSA, by Region

Region Calculated Wastewater

Flow (m3/day) a Current WWTP

Capacity (m3/day) b Untreated Septage

(m3/day)

Al Baha 56,000 0 56,000

Al Jouf 69,000 38,000 31,000

Assir 294,000 82,500 211,500

Eastern Province 648,000 527,300 120,700 c

Hail 93,000 19,200 73,800

Jizan 203,000 20,000 183,00

Al Madinah 275,000 351,000 none c

Makkah 1,100,000 888,000 212,000 c

Najran 78,000 0 78,000


Qaseem 185,000 131,500 53,500

Riyadh 1,066,000 993,500 72,500 c

Tabouk 120,000 60,000 60,000

Totals

4,234,000 3,135,000 1,175,000 a Calculated values taken from Chapter 1 b Based on IntelConsult 2009-2010 reports and other known information, as presented in Chapter 1 c While sufficient capacity may be present, collection infrastructure may be lacking

It is recognized that WWTP capacity is only part of the story. Many areas may have adequate WWTP capacity or have capacity that is not fully utilized because of a lack of collection systems. In Riyadh, for example, there is still significant trucking of wastewater. There was on the order of 1,500 to 2,000 tanker trucks per day discharging wastewater to the Al-Nazeem Sewage Lake east of Riyadh until early 2011, when a station was constructed to receive this wastewater into the collection system of Riyadh. This site alone accounts for 20,000 to 30,000 m3/day of wastewater, assuming an average tanker truck volume of 20 m3. There are also receiving stations at the major WWTPs in Riyadh.

In Jeddah, the new Airport-1 WWTP has been commissioned but currently has no wastewater collection system connected to the facility. As of July 2011, it is treating approximately 60,000 m3/day of wastewater, all received from tanker trucks. The WWTP has a capacity of 250,000 m3/day.

To supplement the rough estimate of the magnitude of the septage problem, Figure 8-8 presents this information another way; in regions where WWTP capacity is expected to have a shortfall, there will be septage being trucked. In the urban areas such as Riyadh and Jeddah, most trucked wastewater is probably being treated, though inadequately treated wastewater is clearly also a groundwater quality problem.

The more critical issue is in the shortage of treatment capacity in many rural areas. It is expected that the volume of septage lacking treatment will decrease by 2035, even as the population grows, due to the ongoing WWTP infrastructure investments planned in KSA. Data used to generate Figure 8-8 may not reflect all eventual WWTP capacity and therefore may not reflect this expected decrease. The data also do not reflect problems caused by lack of conveyance capacity where WWTP capacity is adequate.


STRATEGIC STUDY 8-9

FIGURE 8-8 Projected Wastewater Treatment Capacity Shortfalls in KSA Regions (Based on ItalConsult, 2009-2010)

The largest amount of septage generated and lacking adequate WWTP treatment apparently occurs in the Makkah region. This is not unexpected given the extreme fluctuation in wastewater volume generated in this region during pilgrimages. Other regions with more than 100,000-m3/d shortfalls in their current treatment capacities are Assir and Jizan. Regions farther ahead with regard to infrastructure planning, showing excess WWTP capacities, are the Eastern Province and Riyadh. In Riyadh, for example, the amount of wastewater generated is expected to double between 2010 and 2025. While capacity in these areas may be sufficient, collection systems may not be sufficient yet and localized septage issues may still be occurring. While these septage totals are presented at the regional level, septage is a very localized infrastructure problem.

8.1.5 Potential Problems Associated with Septage Disposal Environmental impacts can result from septage that is not treated. If sewage remains in cesspits, groundwater contamination can occur. This untreated wastewater infiltrates into the ground, creating both water quality problems and artificially high groundwater levels. This is especially a problem in coastal areas such as Jeddah that already have high surficial groundwater levels. There are also potential issues associated with nuisance odors, public health issues associated with pathogens, and vectors (primarily rodents and insects) for pathogens.

If sewage is instead held in holding tanks, it must be trucked to a WWTP or sewage lake. This hauling by trucks has environmental impacts: carbon emissions that increase KSA’s carbon footprint, the potential for leaks onto roadways or into adjacent lands, and the potential for illegal dumping. This dumping could occur if a truck is turned away from a WWTP because it does not meet the quality specifications or if the receiving facility simply cannot accept more trucks that day. This can occur, as there is not sufficient WWTP capacity in many areas.

-350,000

-250,000

-150,000

-50,000

50,000

150,000

250,000

350,000

Al Baha Al Jouf Assir Eastern Province

Hail Jizan Madinah Makkah Najran North Borders

Qaseem Riyadh Tabouk

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t Cap

acity

Def

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2035

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To avoid these potential problems, additional septage handling and decentralized treatment facilities should be quickly constructed in KSA. In urban areas, septage handling facilities can be used where there is sufficient wastewater treatment capacity. The additional septage facilities can aid in managing the ancillary issues associated with hauling wastewater, especially traffic congestion and noise associated with the trucks. Decentralized treatment facilities for septage can be used in urban or more rural areas as a way to treat septage locally. These systems also have the advantage of providing RQTSE while reducing the need for extensive reuse water distribution systems in site-specific applications. Other disposal options for septage, such as use as an organic source for anaerobic digestion, composting, or treatment in various types of small treatment facilities, are discussed in the next section.

8.2 Solutions for Septage Handling and Treatment Septage has a relatively high organic content (i.e., COD exceeding 5,000 mg/L), typically an offensive odor and appearance, and a resistance to settling and dewatering. Septage is also a host for many pathogenic microorganisms (USEPA, 1994). As a result, septage requires special handling and treatment. The most convenient option is to bring septage and treat it in an existing WWTP. Currently, this approach has a limitation because the existing WWTPs in KSA have limited capacities and only accept a small fraction of the septage generated in KSA. While current infrastructure has limited capabilities, it is recommended that the WWTP expansions planned for the near future provide storage facilities and additional capacities for septage handling and treatment. The most benefits can be gained in large treatment facilities where degritted and concentrated septage after liquid/solids separation can be fed into the anaerobic digesters to maximize biogas production. The biogas benefits, in most cases, can offset the investment needed for additional infrastructure for holding and pretreating septage. Infrastructure investments are necessary and the development of business opportunities for reuse will assist in addressing the untreated septage issues in KSA.

8.2.1 Septage Handling and Treatment Options Despite having limited opportunity for treating septage in existing WWTPs, there may be a wide range of solutions to treat septage while recovering water, nutrients, and energy from the septage.

Septage handling and treatment options may include:

• Pre-treatment systems for providing treatment prior to input to other WWTPs, including new treatment facilities

• Stabilization of septage before land application. The most common stabilization techniques include, but are not limited to:

− Chemical addition − Aerobic digestion − Anaerobic digestion − Composting

• Land application

• Decentralized septage treatment facilities for treatment and production of RQTSE

Pretreatment System A pretreatment station is an ideal first step for septage that is received from trucks, regardless of the type of treatment system receiving the wastewater, because some of the



material in septage may cause problems at the WWTP. Pretreatment accomplishes adequate removals of solids fats, oil, and grease (FOG) and other coarse material. An example design of a pretreatment station is in rural Jordan, part of a small wastewater system design from a USAID project (USAID, 2008). For this facility, screens are used to separate the coarse solids and floating materials which are then compacted and hauled to nearby landfills.

Stabilization Stabilization is a treatment method that decreases pathogenic organisms and odors. Physical, chemical, and biological methods can be used for stabilization. The most commonly used stabilization techniques include:

• Chemical stabilization: lime or other alkaline material is added to liquid septage to raise the pH to 12.0 for a minimum of 30 minutes to kill pathogens and reduce odors.

• Aerobic digestion: Septage is aerated for 15 to 20 days in an open tank to achieve biological reduction in organic solids and odor potential. The time requirements decrease with increased temperatures. Aerobic digestion is an energy-intensive process and does not provide any useful end products (i.e., biogas).

• Anaerobic digestion: Septage is digested in an enclosed tank for about 15-30 days to achieve biological reduction of solids. Mixing and heat are often provided to improve digestion performance. Produced biogas during anaerobic digestion can be converted to heat and electricity. However, biogas to energy benefits can primarily be recognized only in large-scale applications and when septage and wastewater solids are digested together. Blending wastewater solids with septage can minimize digester overloading and ensure stable operation.

• Composting: Septage is mixed with wood chips, sawdust, or other material and aerated mechanically or by turning. Biological activity generates temperatures that are sufficient to destroy pathogens. The composting converts septage into a stable, humus material that can be used as a soil amendment. This process tends to create odors which need to be handled properly.

Land Application and Soil Amendment After the septage is stabilized, it can be used for land application. Land application of septage is a commonly used disposal method in many parts of the world. It is relatively simple, uses low amounts of energy, and recycles organic material and nutrients to the land. Domestic septage is a resource containing nutrients that can condition the soil and decrease reliance on chemical fertilizers for agriculture (USEPA, 1994).

Decentralized Treatment Facilities. There are a wide number of options for decentralized small systems ranging from lagoon systems and treatment wetlands to a range of package and designed wastewater systems.

Small Satellite Package Units. When existing WWTPs do not have adequate capacity, or are too far to transport septage, septage can be treated via package treatment facilities. Package membrane bioreactor facilities (500-2,000 m3/day) are designed to treat septage in a small footprint while producing very high quality treated water. With the addition of a disinfection step (i.e., package UV light disinfection or chlorine disinfection), these package facilities can produce reclaimed water that meets unrestricted reuse criteria. Multiple package MBR suppliers (General Electric, Siemens, Dow, etc.) are in the KSA market, allowing procurement of facilities in a timely manner.



Sewage Lagoons. Sewage lagoons may be ideal if sufficient land is available outside a city and if WWTP treatment capacity has not yet caught up to demand. A sewage lagoon should be designed with: • A lining or other method to limit the potential for groundwater and soil contamination that

sewage lakes without barriers can cause

• A proper dam to hold a final storage volume, so that many iterations of construction do not occur

• An operations plan, with a design of many cells, to rotate annual clean-up activities such as sludge removal to maintain capacity

• A plan for clean-up from the start, so that waste entering the lagoon is tested, a plan to empty the lake is developed, and where treatment would occur is known

• A sludge management plan, so that during clean-up, sludge can be treated and beneficially used for agriculture if appropriate

A lagoon system could be coupled with a septage pretreatment facility as described above. A design option could include multiple primary cells dredged annually on an alternating basis, with solids dried on sludge drying beds and liquids sent to the other cells or to a WWTP for treatment. This would preserve storage capacity. Such improved design of sewage lagoons could also mimic the “oxidation ponds” design, allowing more significant organics and nutrient reduction.

Constructed Wetlands. Constructed wetlands alone cannot typically be used for septage due to the high loading found in septage (solids, BOD, nitrogen, and phosphorus). Combining this process with other more conventional steps can, however, achieve the desired treatment quality. Constructed wetlands could include reed beds as one polishing treatment step, as has been done in some regions in MENA. Such effluent is typically suitable for reuse (USAID, 2008). Figure 8-9 shows a reed bed used for effluent polishing followed by a storage basin for RQTSE storage.

FIGURE 8-9 Photographs of Reed Bed Effluent Polishing System Followed by Storage Basin for RQTSE (USAID, 2008) Low Technology Septage Treatment Systems. Two low technology septage treatment plants serving small, remote municipalities and neighboring villages were recently put into operation through a USAID Project in Jordan (USAID, 2008). Those plants were implemented as model systems for dispersed areas where wastewater collection by conventional sewers was too expensive (capital and operating costs). Those centralized facilities, one in the south of Jordan (Shobak) and one in the north of Jordan (North



Shouneh) include multiple treatment steps, producing effluent in full compliance with water reuse standards currently in place in the country. The Shobak Septage Treatment Plant is a zero discharge facility, while North Shouneh has a dedicated RQTSE irrigation system serving neighboring farming operations.

Shobak (a village located on the road to Petra) has cold winters and inexpensive water for irrigation; as a result, effluent reuse could not be implemented cost-effectively. The plant was designed to receive an average of 350 m3/day of septage from cesspits brought in by tankers from Shobak and neighboring municipalities (mainly Qadissiyeh and Husseiniyeh), benefitting a dispersed population of about 3,000 people. This treatment plant includes the following unit processes:

• Pretreatment system for removal of floating materials, FOG, and other coarse objects; screenings discharged to nearby landfill

• Imhoff Tanks for solids separation and digestion

• Drying of solids from the tanks on sludge drying beds designed for the arid climate in Jordan

• Liquid subsequently sent to several retention/evaporation ponds designed based on regional water balance calculations (rainfall and evaporation rates)

The other unique aspect of this plant is its operation by Shobak Municipality, which signed a 20-year agreement with the Ministry of Water and Irrigation in Jordan.

The septage treatment facility serving North Shouneh and several neighboring villages was designed to receive approximately 3,000 m3/day of septage (Figure 8-10). The treatment plant includes the following unit processes:

• Septage receiving stations are used to accept septage from tankers.

• Pretreatment (coarse in-channel screens) is used for removal of floating and coarse materials and FOG. In the larger septage treatment plants (such as Ain Ghazal), mechanical screens, oil/water separators, and sand removal are commonly used.

• The plant has two parallel treatment trains providing full redundancy during clean-out and maintenance periods.

• Sludge from Imhoff Tanks (deep static sedimentation tanks with conical bottoms designed to receive and digest solids over several months) is removed during the hottest months of the year and spread on drying beds. Sludge drying beds are considered the simplest, most reliable, and cost-effective method of drying in the region.

• Liquid from the Imhoff Tanks enters a series of anaerobic denitrification cells. Primary effluent from the Imhoff Tanks is mixed with recirculated nitrates from the reed beds.

• The next treatment step includes semi-facultative lagoons that allow significant organics and nutrients reduction. Surface aerators could be added in the future for eventual increased treatment capacity.

• Multiple intermittent sand filters provide additional organics, solids, and nutrient removal. Those filters are manually raked, as the local choice was not to add technology but to allow for more jobs.

• The constructed wetlands are the polishing step, providing effluent in compliance with current Jordanian standards for reuse; the reed bed type was selected based on excellent viability of this type of vegetation in the area.



• The final step (the only mechanical component of the plant) is a nitrified effluent pumping station conveying the clean water to the front of the plant into the plant’s denitrification cells.

• Two treated effluent storage ponds (earthen basins with lining) are the last treatment plant component. Nearby farmers can take water from those ponds for irrigation depending on their seasonal needs.

This type of approach reduces infrastructure investment and provides benefits to local end users.

FIGURE 8-10 Process Flow Diagram of North Shouneh Septage Treatment Facility

8.2.2 Removal of Septage Lakes As adequate infrastructure is established, existing sewage lakes will require cleanout plans and actions, similar to those conducted at the Sewage Lake east of Jeddah and those in progress for Al-Nazeem Lake outside of Riyadh. The presence of these sewage lakes is not widely publicized. Currently, MOWE infrastructure plans are focused on communities with populations of 5,000 or more, with the goal of having adequate WWTP and reuse infrastructure in place by 2025. This approach will eventually address many of the impacts associated with septage. However, it does not provide information related to the magnitude of the required clean-up effort or a plan to address issues in smaller communities. While the situations in Jeddah and Riyadh are significant, these issues will likely be addressed relatively quickly due to the progressive efforts of the NWC. However, in other areas there is not enough information to truly assess the magnitude of the problem.

In order to comprehensively assess the issues with septage, the following need to be obtained:

• Locations of existing septage lakes

• Estimate of current wastewater inputs to the lake

• Evaluation of the likelihood of additional industrial contamination or petroleum contamination to allow assessment of potential issues associated with proper disposal of water and/or sludge



• Assessment of alternative disposal locations for septage

This information would allow assessment of the magnitude of the problem, evaluation of the time necessary to develop alternatives, and determination of funding needs. The specific sewage lake issues can then be prioritized by regions and it will be possible to assess whether (1) planned WWTP and reuse infrastructure improvements will aid in addressing the issue in a reasonable time frame or (2) one of the small system solutions summarized above needs to be implemented to address the situation.

Although each sewage disposal situation has unique features, some likely outcomes can be presumed from the cases to date:

• With the significant evaporative losses in KSA such as an estimated 2.1 m per year in the humid western regions near Jeddah (CH2M Olayan, 2011a), water will not remain in any sewage lake for a significant period of time after septage inputs are eliminated.

• Sludge resulting from primarily domestic wastewater will be fairly well digested in the bottom of highly productive sewage lakes and will have a high likelihood of being remediated in place as a soil amendment or transported to other areas for agricultural use. The need for treatment with lime to address potential pathogens should be addressed in every case, although this was not necessary for the Jeddah Sewage Lake (CH2M Olayan, 2011b).

• Even petroleum-contaminated sludges may have a high likelihood of in-place remediation with activities designed to assist in volatilization of volatile and semi-volatile hydrocarbons and mixing with mineral soils, as is the case with the Jeddah Sewage Lake.

• Issues associated with industrial contaminants such as heavy metals, solvents, or other organic chemicals need to be assessed on a case-by-case basis and appropriate disposal methods employed.

Sewage lakes are a remnant of inadequate wastewater treatment infrastructure and can be remediated in a way that utilizes the remaining material, the organics and nutrient content of sludge, as a resource. Reuse of the water in sewage lakes for irrigation or other purposes depends on the proximity of suitable areas close to the lake, as well as the quality characteristics of the water. Once a solution to dumping septage in the lake is implemented, thus eliminating water inputs, any use of the lake water would need to be implemented quickly, since evaporation is rapid in the arid environment of KSA.

8.3 Summary The technologies and examples discussed in this chapter present several alternatives for managing septage. These include issues within larger communities that primarily lack conveyance infrastructure to transmit wastewater to WWTPs as well as options for treatment and disposal for smaller communities. Smaller decentralized systems have an advantage of producing reuse water that can be used locally in the vicinity of the wastewater treatment facility. The technologies and examples show how various treatment steps can be achieved efficiently and how different combinations of treatment can still achieve RQTSE or utilize septage in ways that take advantage of the nutrient value. An example shows how natural treatment systems provide the final steps in generating RQTSE, which farmers can then use. Reuse infrastructure was not installed; however, reuse benefits are achieved by producing quality effluent and making it accessible to users. This greatly reduces infrastructure investment costs and yet provides benefits to local end users.

The biggest gap in dealing with septage is the lack of comprehensive information necessary to assess the problem and develop solutions. The Draft MOWE Regional Planning Reports



provide very little information regarding the issue other than the plan to move forward for the communities of 5,000 or more to provide wastewater treatment infrastructure, including production of RQTSE (ItalConsult, 2009-2010). The septage issue should be comprehensively assessed such that specific plans can be incorporated to address this issue on a short-term basis for areas where infrastructure is under development, and permanent solutions can be identified for septage issues in more rural communities.

8.4 References CH2M Olayan. 2011a. Jeddah Sewage Lake Evacuation and Sediment Reuse/Disposal Plan. Prepared for National Water Company, Kingdom of Saudi Arabia.

CH2M Olayan. 2011b. Jeddah Sewage Lake: Site Release Sampling Draft Report. Prepared for National Water Company, Kingdom of Saudi Arabia.

ItalConsult. 2009-2010. Wastewater Reuse Planning Reports prepared for the Ministry of Water and Electricity (MOWE) for each of the 13 Regions:

• Al Baha; February 2010 • Al Jouf; July 2009 • Assir; December 2009 • Eastern Province; January 2010 • Hail; July 2009 • Jizan; March 2010 • Al Madinah; January 2010 • Makkah; October 2009 • Najran; August 2009 • Northern Borders; June 2009 • Qaseem; October 2009 • Riyadh; December 2010 • Tabouk; July 2009

Kingdom of Saudi Arabia Central Department of Statistics and Information (CDSI). 2010 Census Population. www.cdsi.gov.sa. Accessed June 2011.

Personal communication with NWC, 2011. Discussions with Engineer Turki M. Al-Thubaiti, Manager of Aleskan Treatment Plants, National Water Company.

SAFEGE, 2006. Full Audit of Water and Wastewater Services in Jeddah City – Detailed Diagnosis Report – Final. August 2006.

U.S. AID. 2008. Wastewater Treatment Plants for Two Small Communities.

USEPA, 1994. Guide to Septage Treatment and Disposal. EPA Office of Research and Development. Washington, D.C. EPA/625/R-94/002.

http://www.cdsi.gov.sa/

STRATEGIC STUDY

Chapter 9: Patent Landscape

9.1 Introduction and Objectives The chapter presents an analysis of the patent landscape for water treatment technologies that could have water reuse applications. The analysis provides readers with a high-level overview of trends in invention and patenting of technologies for water reuse.

Because this chapter focuses on water-reuse–related technologies, it covers similar ground to others in the report (e.g., Chapter 2). However, by analyzing the patent landscape, the chapter provides a somewhat different perspective. In particular, it enables analysis of trends in technology innovation—by technology category, by geographic region, and over time.

Most readers will primarily be interested in the summary section of this chapter (beginning on page 9-33), which presents the key commercially relevant insights drawn from the patent analysis. The remainder of the chapter is laid out as follows:

• Methodology: describes the approach taken for assembly and analysis of the patent portfolio.

• Overview of the patent landscape: sets out conclusions at the highest level, covering all water-reuse–related technologies.

• Category-level landscapes: presents findings at a more detailed level for key technology categories.

9.2 Methodology The following steps were undertaken to analyze the patent landscape for water-reuse–related technologies:

• A search of patent databases to find relevant technologies • Screening of the resulting patent portfolio to remove irrelevant records • Analysis of the final patent portfolio to identify trends

The search strategy included both key term and patent classification-based approaches. Key terms searched for included the following:

• Water reuse and recycling • Wastewater and water treatment/management, sludge treatment/management • Membranes, reactors, bioreactors, filtration, purification, disinfection, microorganisms,

and ozonation

The search looked for these key terms in both the original patent fields and the Derwent World Patent Index (DWPI) patent content. DWPI is a value-added system that offers not only manually rewritten titles, abstracts, and first claims using more standard vocabularies, but also a series of additional searchable fields such as technology focus, use, novelty, and detailed technology descriptions to considerably enhance coverage and accuracy.

CHAPTER 9: PATENT LANDSCAPE

9-2 STRATEGIC STUDY

Classifications searched encompassed those listed below (including subclasses of each code):

• International Patent Classification (IPC) code C02F: Treatment Of Water, Waste Water, Sewage, Or Sludge

• IPC code C02F 0003: Biological Treatment Of Water, Waste Water, Or Sewage

• DWPI manual code D04-A: Treating Water, Waste Water And Sewage -> Treatment Of Water [Process General]

• DWPI manual code D04-B: Treating Water, Waste Water And Sewage -> Impurity Removal From Water

• The search undertaken was restricted to applications made after the beginning of 2000. The searches were also restricted by geography—covering the US, Japan, and the European Union.

The 40,000 patent records generated by the search strategy were screened to ensure that only those relevant to water reuse treatment were captured—e.g., using patent codes, text filtering. Records duplicated across different geographies were removed. In addition, where two or more records existed for the same basic invention (for example, one patent exists for the original invention, and then several subsequent patents are granted to cover incremental improvements to the invention), only the most recent record was retained. After this screening process, around 24,000 unique records remained.

A process of assignee unification was also undertaken to facilitate a more thorough analysis. Patent assignees are frequently listed under various names; for example, the Japanese conglomerate Hitachi was listed in the patent portfolio with over 70 different names (including subsidiary companies). Because of the size of the patent portfolio, it was generally only possible to carry out assignee unification on the basis of companies with similar names. It was generally not feasible, therefore, to identify all subsidiary organizations—although attempts were made to do this in some instances with well-known companies.

Results of the patent portfolio analysis are presented in the remainder of this chapter). The most significant analysis—categorizing all the patent records into different technology areas—was a challenging exercise, particularly for such a large portfolio that is both diverse and interrelated. Both top-down and bottom-up approaches were used to identify categories within the portfolio. The top-down approach entailed looking for key terms describing expected technology categories, for example, biological treatment or disinfection. The bottom-up approach used text-mining techniques and reviewing of patent codes to reveal categories within the portfolio in a more organic fashion.

9.2.1 Distortion Caused by Trends in Japan Analysis of the patent portfolio quickly revealed that trends in Japanese patenting activity can distort the global picture. At issue is the steep decline in patent applications since 2000 that completely dominates trends in activity over time at the global level (see, for example, Figures 9-3 and 9-5)—due to both the rapid rate of the decline and the large proportion of Japanese patents in the global portfolio.

While this trend is useful to observe, it is necessary to ensure that its importance is not overemphasized as it appears to be representative of a broader trend in patenting strategy in the Japanese system, rather than any decline in innovative activity related to water treatment technologies. As the Japan Patent Office (2010) recently noted, “…more applicants are changing their intellectual property strategy from acquiring and filing a large volume of patents to acquiring high-quality patents ….” Therefore, wherever possible, analysis of patenting activity over time has been done at a sub-global level, and conclusions have been


STRATEGIC STUDY 9-3

drawn on the basis of changes in European and US activity, with Japanese trends largely ignored.

9.3 Overview of Water Reuse Technology Patent Landscape This section presents an overview of the water reuse technology patent landscape at the highest level. It sets out the main technology categories that make up the landscape and analyzes trends in patenting activity across different geographies and over time. It also explores leading patent assignees.

9.3.1 Technology Categories As described above, the patent portfolio was analyzed to identify the key technology categories captured in the patent searches. The results of this categorization are set out in this section. Table 9-1 describes the different technology categories identified.

TABLE 9-1 Categories within Patent Portfolio

Category Name Description

Disinfection Disinfecting or decontaminating wastewater and sludge using various methods, including halogenation, oxidization, ozonation, pasteurization, ultrasound, UV, and “other.”

Removal/Recovery and Petrochemical Technologies

Removal or recovery of sulfur, phosphorous, metal- and nitrogen-containing compounds, and petrochemicals from wastewater and sludge.

Sludge Treatment Technologies Pyrolysis of sludge, hydrolysis, and sludge pretreatment.

Bioreactors and Microbial Technologies

Biofuel/biogas, aerobic and anaerobic treatment, bioreactors, and microbial technologies associated with treating, recycling, and energy generation of wastewater and sludge.

Filtration, Membranes, and Solids

Separating or removing solids or particles from fluids, processing wastes such as sludge, contaminated soil, animal manure, and organic waste from food; and membrane (including FO and RO) and filtration technologies.

Ecosystems, Domestic, and Miscellaneous

Treatment and water management of rivers, lakes, wetlands, and ponds. Home applications. Aquifer recharge.

Figure 9-1 shows the breakdown of patents across the different categories identified. The category “Filtration, membranes & solids” is by far the largest—with over 40 percent of the total patent set, it is over twice the size of any of the other categories. The smallest category overall is that of sludge treatment— with just 1 percent of the total patent data set.

Further breakdown of the technology mix within each of these categories is provided in the sections below.

Many patents or published applications fall into more than one of the defined categories. The graph below (Figure 9-2) illustrates this overlap by showing what proportion of technologies within a given category either are unique to that category alone (black bar) or fall into one of the other categories.

To some extent this overlap is an artifact of the categorization system being a hybrid of treatment technologies (e.g., filtration, disinfection) and applications (i.e., removal/recovery & petrochemical technologies and ecosystems, domestic, & misc). However, some of the overlap is suggestive of the enabling role of some technologies. In particular, filtration technologies would appear to be the most important enabling technology as they play a role in a large proportion of inventions in other technology categories.


9-4 STRATEGIC STUDY

FIGURE 9-1 Breakdown of Patent Portfolio by Technology Category

FIGURE 9-2 Overlap between Technology Categories

9.3.2 Trends in Patenting Activity by Geography Figure 9-3 below illustrates the geographic spread of the patents identified in the search. Clearly, Japanese activity dominates the global picture, with over two-thirds of total patenting activity (i.e., patent applications and granted patents) in the time period. The US is next with just over a quarter of all patenting activity between 2000 and 2009. Activity in Europe is significantly lower with just 7 percent of total patenting activity during the same time period.

As discussed in Section 9.2, the very large number of Japanese patents is the product of the Japanese patent system where the focus until recently has been on quantity of patents rather than quality. The move away from that strategy is also evident in Figure 9-3, which shows a steady rapid decline in Japanese patenting from a point in 2000, where Japanese patents accounted for 83 percent of all patents in the three regions, to 2009, when Japanese and US patenting activity were virtually equal.

0%

25%

50%

75%

100%

Disinfection Removal & Petrochemical

Sludge Treatment Bioreactors & Microbial

Filtration, Membranes, &

Solids Ecosystems,

Domestic, & Misc

Unique to this category Disinfection Removal & Petrochem Techs Sludge Treatment Techs Bioreactors & Microb. Techs Filtration, Membranes, & Solids Ecosystems, Domestic, & Misc

Disinfection 42%

Removal & Petrochemical

19%

Sludge Treatment

15%

Bioreactors & Microbial

12%

Filtration, Membranes, &

Solids 11%

Ecosystems, Domestic, &

Misc 1%


STRATEGIC STUDY 9-5

The tendency to focus on quantity of patents in Japan is illustrated, to some extent, by the patent pipeline in Japan (see Figure 9-4), which shows the relative dominance of published applications in the Japanese patenting system—particularly when compared to the US.

FIGURE 9-3 Patenting Activity (Published Applications and Granted Patents) by Geography

FIGURE 9-4 Patent Pipeline – Published Applications versus Granted Patents, by Geography, 2000-09

9.3.3 Trends in Patenting Activity Over Time Patenting activity related to water reuse technologies at a global level1 has been in a fairly steady decline since around 2000, decreasing at a rate of around 4 percent per year.2 However, when viewed at a regional level (see Figure 9-5), it is clear that this global-level 1 “Global” is used throughout this chapter to refer to the collective portfolio of patents and applications across the three geographic regions of Japan, the United States, and Europe—not to the entire world. 2 Measured as a compound annual rate.

0%

25%

50%

75%

100%

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

US

JP

EP

82%

49%

77%

18%

51%

23%

0%

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50%

75%

100%

Japan US EU

Published Applications Granted Patents


9-6 STRATEGIC STUDY

trend is entirely driven by the rapid decline in Japanese patenting activity. Patenting activity in Europe and the US has, in fact, been steadily increasing. Over the period from 2000 to 2009, the compound annual growth rate in US activity was 9 percent, while the rate in Europe was 3 percent.

FIGURE 9-5 Patent Filings over Time by Geography

Note: application year data for 2010 are incomplete due to the 18-month delay between application and publication.

Similar trends exist at the technology category level, as shown in Figure 9-6. Growth in the US is particularly strong, with all categories growing by at least 5 percent per year. The two categories with the strongest growth in the US are Removal/Recovery and Petrochemical Technologies and Filtration, Membranes, and Solids.

Growth in Europe is slower for all categories and is more variable across categories. For example, growth is particularly slow in these technology categories:

• Removal/Recovery and Petrochemical Technologies • Sludge Treatment Technologies • Ecosystems, Domestic, and Miscellaneous

9.3.4 Leading Patent Assignees Trends in the leading assignees of water-reuse–related technologies are similar to those seen at a geographic level. Table 9-2 shows the top five assignees of patents or published applications—globally, and for US and EU patents. The top five assignees globally are also the top five assignees of Japanese patents, with an order of magnitude more patents or applications than the top assignees of European or US patents.

In another reflection of trends at the geographic level, patenting activity among the top five assignees of Japanese patents has markedly dropped off. Top holders of US and European patents on average have increased their activity slightly. Particularly noteworthy is the increase in patenting activity by Siemens, Veolia, and (to a lesser extent) General Electric in recent years.

0

500

1000

1500

2000

2500

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Num

ber o

f fili

ngs

EU Japan US


STRATEGIC STUDY 9-7

FIGURE 9-6 Change in Patenting Activity over Time – by Technology Category and Geography

TABLE 9-2 Top Assignees of Patents and Published Applications Note: Darker shading indicates greater activity. The majority of the companies that are leading assignees of water-reuse–related patents are very large (e.g., revenues in the tens to hundreds of millions annually) industrial conglomerates such as Hitachi, Suez and GE.

Table 9-2 helps to reveal the different patenting approaches companies take in different jurisdictions. Hitachi is an assignee on nearly 1,000 Japanese patents or applications. However, it is an assignee on just 42 US and European patents—far less than in Japan, but comparable to other top five assignees in those jurisdictions.

It is also possible to observe in Table 9-2 that leading assignees tend to hold a small percentage of the overall patent portfolio. The top five assignees of US and EU patents or published applications, for example, account for just 3 percent of the total portfolio. The remaining patents/applications (approximately 7,500) are held by over 3,500 organizations.

-15%

-10%

-5%

0%

5%

10%

15%

Disinfection Removal &Petrochemicals

SludgeTreatment

Bioreactors &Microbial

Filtration,Membranes, &

Solids

Ecosystems,Domestic, &

Misc

Com

poun

d A

nnua

l Gro

wth

Rat

e 20

00-2

009

EU

Japan

US

Company 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Total

Hitachi 198 120 122 99 99 83 72 58 36 36 7 930 Kurita Water Industries 118 142 115 63 92 99 85 60 67 28 10 879 Mitsubishi 88 131 100 66 59 67 55 40 36 19 10 671 Toray Industries 50 58 33 41 35 48 45 42 48 16 7 423 Sumitomo 64 61 37 39 46 39 34 21 32 20 4 397

Siemens 0 2 0 2 2 6 14 16 18 10 12 82 Veolia 0 3 2 2 2 7 3 4 11 12 4 50 General Electric 2 3 1 4 1 6 5 4 6 9 5 46 Suez 9 3 4 2 0 5 2 3 5 5 5 44 Hitachi 3 4 3 1 4 3 7 3 4 4 6 42

Top 5 assignees of US & EU patents / published applications

Top 5 assignees of patents / published applications


9-8 STRATEGIC STUDY

This illustrates how innovation in the water technology sector is diffuse—and suggests that a partnership or open innovation approach to technology development is critical to success.

9.3.5 Key Findings at Overview Level Based on the preceding analysis, the following high-level conclusions can be drawn:

• Since 2001, patenting activity related to water treatment technologies in the US and EU has steadily increased. Patenting activity in Japan has dramatically declined; however, that appears to be the result of a change in patenting strategy (i.e., focus on quality) rather than a decline in innovative activity.

• Patenting activity by leading assignees of US and EU patents and applications has tended to increase or remain broadly steady. Patenting by Japanese companies has declined significantly; however, they still retain by far the largest patent portfolios in this technology space.

• Growth in US-based patenting activity is strong (above 5 percent) across all technology categories. European activity at the technology category level is more variable. The strongest growth rate across both geographies is in the Filtration, Membranes, and Solids category.

• A significant number of patents can be grouped into multiple technology categories, showing that in some cases the technology is enabling, or applicable to multiple topics.

• Patenting activity is diffuse—spread across several thousand companies, each with only a few patents. A partnership or open innovation approach to technology development in the water treatment technology sector is therefore critically important.

The remainder of this chapter explores each of the six technology categories in more detail.

9.4 Category 1: Disinfection This category explores patents related to the disinfection of water—that is, processes by which a significant percentage of pathogenic organisms are killed or controlled. The category includes the following seven technology areas as subcategories, characterized by the mechanisms that are used to kill the pathogens:

• Ultraviolet – use of UV radiation (e.g., from a low-pressure mercury lamp) to destroy pathogens

• Halogenation – use of halogens (e.g., chlorine) to destroy pathogens

• Oxidation – use of strong chemical oxidants to destroy pathogens

• Ozonation – use of ozone to destroy pathogens

• Ultrasound – use of ultrasound as a source of cavitations that destroy pathogens

• Pasteurization – use of heat to destroy pathogens

• Other – other disinfection technologies not included in the above categories; for example, use of PAA, microwave radiation, or photocatalysis to kill micro-organisms.

9.4.1 Key Findings Analysis of disinfection-related patents is presented in Section 9.4.2 below. From that analysis, the following key findings are highlighted.

On the share of different technologies …


STRATEGIC STUDY 9-9

• Oxidation clearly dominates the landscape of disinfection technologies with around twice the number of patents and applications in the next largest category—ozonation.

• UV, halogenation, and “other” disinfection technologies, with a share of between 10 percent and 15 percent globally, are small but important categories in the patent landscape.

• Ultrasound and pasteurization disinfection appear to be niche technologies—at least on the basis of the patent landscape alone.

On trends across different geographic regions …

• The spread of disinfection patents and applications across the three geographic regions is broadly similar to trends at the global level. The only subtlety is that US patents appears to include a slightly larger share of the disinfection portfolio—and Japan’s share is commensurately smaller.

• Generally, the breakdown of different technologies across regional “portfolios” mirrors the breakdown at the global level—e.g., ultrasound patents and applications represent around 4 percent of disinfection patents at the global level as well as in each of the three regions individually. The only minor exceptions are as follows:

− UV disinfection in Europe, which has a slightly larger share (20 percent) of the European portfolio than the global average (13 percent)

− Ozonation disinfection in the US, which has a slightly smaller share (16 percent) of the US portfolio than the global average (21 percent)

On temporal trends over the last 10 years …

• Reflecting macro-level trends, disinfection-related patenting activity in Japan has been decreasing across all subcategories.

• In other regions, patenting activity is up in all subcategories with the single exception of “other disinfection” technologies in Europe. This result is somewhat suggestive of US dominance in emerging disinfection technologies.

• In the US and Europe, growth is strongest in the UV and ultrasound subcategories, and reasonably strong in halogenation.

• In the oxidation and ozonation subcategories, US activity is exhibiting strong growth while Europe is showing only weak growth. For the pasteurization subcategory, the reverse is true, with strong growth in Europe and only a small increase in activity in the US.

On assignees …

• Patenting activity is dominated by the typical large industrial players (see Table 9-3 for details).

On inventors …

• Globally, leading inventors in disinfection include Miki Osamu, Isaka Kazuichi, and Kataoka Katsuyuki.

• Leading inventors on US and European patents include Markus Baumann, Thomas DeBusk, and Bei Yin.

9.4.2 Analysis of Disinfection Portfolio The analysis of the disinfection portfolio is summarized in Figures 9-7 and 9-8 and Tables 9-3 and 9-4 below.



FIGURE 9-7 Breakdown of Patent Portfolio by Technology Subcategory, 2000-09

FIGURE 9-8 Change in Patenting Activity over Time – by Technology Subcategory and Geography

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TABLE 9-3 Leading Patent Assignees, by Geography and Technology Category

Company Ultra-violet Halogenation Oxidation Ozonation

Ultra-sound

Pasteur-ization

Disinfection: other Total

Top 5 assignees of JP patents/published applications

Kurita Water 26 24 156 54 9 0 12 281

Hitachi 17 5 127 35 8 0 37 229

Mitsubishi 14 20 96 70 5 0 14 219

Ebara Corp 9 17 57 32 12 0 14 141

Fuji Clean Kogyo 16 9 35 47 7 1 15 130

Top 5 assignees of US & EU patents/published applications

Siemens Water 5 5 13 3 0 0 2 28

Veolia 7 1 12 6 2 0 0 28

Suez Environment 4 0 12 8 0 0 0 24

Sanyo 0 3 3 7 1 0 3 17

General Electric 2 3 4 0 1 2 4 16

TABLE 9-4 Leading Patent Inventors, by Geography and Technology Category

Category Leading inventors of patents

from all regions Leading inventors of patents

from US & Europe

Ultraviolet Miki Osamu(5), Miyanoshita Tomoaki(4), Watari Takakiyo(4), Yamazaki Kazuyuki(4)

Abe, Norimitsu(4); Bagley, David(4); Butters, Brian E.(3); Girodet, Pierre(3); Kawai, Chihiro(3); Polak, Walter(3); Wedekamp, Horst(3)

Halogenation Mizumoto Masahiro(5), Sorenson, Jr., Kent S.(5), Miyake Junichi(4), Mori Hiroyuki(4), Nagai Masahiko(4), Okutsu Noriya(4)

Sorenson, Jr., Kent S.(5); Scalzi, Michael(3); Schlingloff, Gunther(3); Yin, Bei(3)

Oxidation Miki Osamu(23), Isaka Kazuichi(22), Kataoka Katsuyuki(16), Miyake Junichi(15), Sumino Tatsuo(11), Wakita Masaaki(11), Yamazaki Kazuyuki(11)

Bagley, David(7); Isaka, Kazuichi(7); Yamasaki, Kazuyuki(6); Butters, Brian E.(4); Carson, Roger W.(4)

Ozonation Shioda Hiroichi(14), Kadokawa Komei(12), Ike Hideaki(10), Kataoka Katsuyuki(8), Muramatsu Yuichi(8),

Hsu, Maxwell(6); Bagley, David(5); Kerfoot, William B.(4); Campo, Philippe(3); Jensen, Lonald, H.(3)

Ultrasound Fujita Toshihiko(4), Nomura Makoto(4), Fuchigami Shinichiro(3), Kobayashi Takuya(3), Sakakibara Takashi(3), Sun, Darren Delai(3)

Carson, Roger W.(3); Sun, Darren Delai(3); Chiba, Kousuke(2); Gysling, Daniel L.(2); Janssen, Robert Allen(2)

Pasteurization Whitekettle, Wilson Kurt(5); Leatherman, Mark D.(2); Millard, Robin(2)

Whitekettle, Wilson Kurt(5); Leatherman, Mark D.(2); Millard, Robin(2)

7Disinfection - other Date Masaki(11), Nishiyama Shuji(7), Okamura Atsushi(6), Sugita Kazuya(5), Hibino Atsushi(4), Katagai Nobuyoshi(4)

McKinney, Jerry L.(3); Yamasaki, Kazuyuki(3)



9.4.3 Landscape: Oxidation This section provides a slightly more detailed landscape of the oxidation-related patents identified during this review. Equivalent sections are provided for three other subcategories that were selected for their potentially high relevance to water treatment for reuse applications in Saudi Arabia: Bioreactors (Section 9.7.3), Anaerobic Treatment (Section 9.7.4), and Forward Osmosis (Section 9.8.3). The section is based on a quick review of the claims and abstract of each patent or application published in the last five years, as well as analysis of patent classifications.

Care should be taken when reviewing these sections—they are based on a quick review of a large and relatively diverse set of patents. It is therefore inappropriate to treat the findings as anything more than initial. Clearly, further review that is both more targeted and more rigorous would be necessary before drawing any definitive conclusions.

Introduction to Landscape Figure 9-9 provides a summary of the patent classifications that appear in the oxidation subcategory. All of the patents and applications published in the last five years were analyzed to identify the IPC codes listed. Each patent lists at least one (and often many) IPC codes indicating the subject of the invention that is patented. The IPC codes analyzed for this exercise were manually ascribed to the patents by specialist editorial staff.

The Figure 9-9 presents a synthesis of the main patent codes found in the oxidation subcategory—indicating the frequency (the “#” columns) with which a particular code is mentioned. Three levels of classification are shown, for example:

1. Treatment of water, waste water, sewage, or sludge 1.1. Biological treatment of water, waste water or sewage

1.1.1. Anaerobic digestion

The first two levels in the hierarchy are arranged in descending order of frequency.

Because of the diversity of IPC codes listed, it is not useful to provide an exhaustive list of code. In general, an attempt has been made to show around 75 percent of the codes. It is highly likely that this results in each patent being represented at least once (since each patent typically has several IPC codes listed).

Key Findings • IPC codes suggest that the following approaches to oxidation are the most prevalent in the

portfolio:

− Using ozone − Using halogens or compounds of halogens − Using air − Using UV light − Using heat

• Use of distillation or evaporation or heat treatment approaches is rare in this technology subcategory.

• IPC codes show that both water and sludge oxidation have been specifically addressed in the portfolio.

• A number of patents in this technology subcategory cover the combination of several different technologies in a staged configuration (e.g., first biological treatment followed by UV treatment)



FIGURE 9-9 Landscape of Oxidation-Related Technologies 2005-2010 • Relatively few patents are ascribed IPC codes specifying the nature of the contaminants the

technology is intended to remove. Those that do mention the following contaminants:

− Halogens or halogen-containing compounds − Nitrogen compounds, e.g. ammonia, Cyanides − Heavy metals or heavy metal compounds, e.g., Chromium or chromium compounds − Organic compounds e.g., containing oxygen or nitrogen



• Another application observed in a quick review of the patents was the removal of oil or other petroleum products.

• In some cases details about the nature of the catalysts used for oxidation are divulged, including the following:

− Molybdenum

− Manganese

− Noble metal such as the platinum group metals (e.g., platinum, palladium), silver, and gold

− Iron, including in combination with catalysts from the following categories: noble metals, manganese, technetium, or rhenium.

• A few technologies specified the structure of catalysts. In all cases, the technologies use solid catalysts.

9.5 Category 2: Removal/Recovery and Petrochemical Technologies

This category explores patents related to the treatment of petrochemicals and to the removal and/or recovery of specific contaminants. The category includes the following five technology subcategories, in the case of contaminant removal or recovery they are described by the specific pollutant:

• Petrochemical treatment • Phosphorus removal • Nitrogen removal • Sulfur removal • Metal removal

9.5.1 Key Findings Analysis of patents related to contaminant removal/recovery & petrochemical technologies is presented in Section 9.5.2 below. From that analysis, the following key findings are highlighted.


• Patents and applications related to nitrogen removal clearly dominate this category—with approximately twice the number of records as any other category.

• The subcategories of petrochemical treatment, phosphorus removal, and sulfur removal are all similarly sized. Metals removal appears to have received the least attention.


• The spread of this technology category’s patents and published applications across the three geographic regions is relatively similar to trends at the global level. The European patent portfolio includes a larger share of this technology category (37 percent) than is present in the global portfolio (29 percent)—and Japan’s portfolio has a commensurately smaller share.

• Generally, the breakdown of different technologies across regional “portfolios” mirrors the breakdown at the global level. Notable exceptions are as follows:

− Petrochemical treatment patents are more dominant in the Japanese portfolio.



− Phosphorus removal patents are more dominant in the European portfolio.

− Nitrogen removal makes up a larger share of patents in the US and European portfolios, than they do in the Japanese portfolio.


• Reflecting macro-level trends, Japanese patenting activity in this category has been decreasing across all subcategories.

• In the US, patenting activity has shown very strong annual growth (8 percent–20 percent), while for Europe the picture is more mixed.

• Experience in the US and Europe suggests the following:

− Interest in metal removal/recovery technologies has grown very strongly over the last 10 years.

− Sulfur removal and petrochemical treatment technologies have seen a significant increase in activity.

On assignees …


• It is notable that three Japanese companies (Ebara, Hitachi, and Sanyo) are leading holders of US and European patents in this category.

On inventors …

• Globally, leading inventors in disinfection include Miki Osamu, Kataoka Katsuyuki, and Sumino Tatsuo.

• Leading inventors on US and European patents include Christian Uphoff, Kazuyuki Yamasaki, and Bei Yin.

TABLE 9-5 Leading Patent Assignees, by Geography and Technology Subcategory

Company Petrochemical

treatment Phosphorus

removal Nitrogen removal

Sulfur removal

Metal removal Total


Kurita Water 6 36 112 32 23 209

Hitachi 4 48 117 17 19 205

Mitsubishi 8 30 78 38 32 186

Ebara Corp 4 47 55 16 20 142

Fuji Clean Kogyo 1 19 42 12 14 88


Ebara Corp 1 4 3 4 4 16

Siemens Water 2 5 5 3 1 16

Hitachi 1 2 11 0 1 15

Sanyo Electric Co 0 4 8 1 2 15

General Electric 7 2 1 4 0 14



TABLE 9-6 Leading Patent Inventors, by Geography and Technology Subcategory



from US & Europe

Petrochemical treatment

Yin, Bei(6), Gysling, Daniel L.(4), Miki Osamu(4), Miyake Junichi(4), Sakurai Kenichi(4)

Yin, Bei(6); Gysling, Daniel L.(4); Dancuart Kohler, Luis P. F.(3); Happel, Henry(3); Hoffjann, Claus(3); Liu, Chunqing(3); Perriello, Felix Anthony(3)

Phosphorus removal Kataoka Katsuyuki(17), Shimamura Kazuaki(9), Yoshida Teruhisa(9), Miki Osamu(7), Hagino Takao(6), Katagai Nobuyoshi(6)

Wanielista, Martin P.(3)

Nitrogen removal Sumino Tatsuo(16), Miki Osamu(15), Yamazaki Kazuyuki(12), Isaka Kazuichi(11), Yamada Katsuhiro(11)

Yamasaki, Kazuyuki(5); Sumino, Tatsuo(4); Tokutomi, Takaaki(4)

Sulfur removal Miki Osamu(11), Yamada Katsuhiro(11), Oishi Toru(9), Miyanaga Toshiaki(7), Sugimoto Hideo(7), Uphoff, Christian(7)

Metal removal Kataoka Katsuyuki(5), Hayashi Hiroshi(4), Matsumoto Akira(4), Miki Osamu(4), Ono Nobuyuki(4)

Cotoras Tadic, Davor(2); Efraty, Avi(2); Fassbender, Alexander G.(2); Krogue, John A.(2); Lee, T. Richard(2); Mitchell, Michael Donovan(2); Moniwa, Shinobu(2); Yen, David(2)

9.5.2 Analysis of Removal/Recovery and Petrochemical Technologies Portfolio

FIGURE 9-10 Breakdown of Patent Portfolio by Technology Subcategory

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9.6 Category 3: Sludge Treatment Technologies This category explores patents related to the treatment of sludge. It includes three technology subcategories that emerged from the patent portfolio:

• Pyrolysis: thermochemical decomposition of sludge at elevated temperatures in the absence of oxygen

• Sludge – Hydrolysis: hydrolysis of organic solids in order to solubilize them

• Sludge – Pretreatment: preparing sludge for further processing, for example, by destroying sludge flocs and the rupturing cell walls

9.6.1 Key findings Analysis of sludge treatment-related patents is presented in Section 9.6.2 below. From that analysis, the following key findings are highlighted.


• The pyrolysis subcategory has the largest share (around 50 percent) of sludge treatment-related patents and published applications. Hydrolysis and pretreatment-related patents each make up about a quarter of the overall portfolio.


• The spread of sludge treatment patents and published applications across the three geographic regions is more diverse than in any of the other technology categories. The share of Japanese records is lowest of all subcategories across the entire portfolio—and virtually the same as the share of US records. European records have substantially higher share than is typical.

• The share of different technologies across regional “portfolios” is different from the breakdown at a global level:

− Pyrolysis patents are more dominant in the Japanese portfolio. − Pretreatment patents are more dominant in the European portfolio.

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• Reflecting macro-level trends, sludge treatment-related patenting activity in Japan has been decreasing, except in the hydrolysis subcategory. This subcategory is one of only two in which Japanese patenting activity has increased.

• In other regions, patenting activity is up in all subcategories with the single exception of pretreatment technologies in Europe.

• In the US and Europe, growth is strongest in the pyrolysis subcategory and otherwise slow or declining.

On assignees …

• Patenting activity is somewhat less dominated by the typical large industrial players (see Table 9-8 for details), than in other categories.

• Notable is the presence of Sanyo and Hymo Corp in the Japanese portfolio, as well as Novozymes and SCT Technologies in the US and European portfolios.

On inventors …

• Globally, leading inventors in disinfection include Miki Osamu, Funato Harurou, and Sasaki Hidenori.

• Leading inventors on US and European patents include Catherine Daines-Martinez, Joseph W. Dendel, Paul John Hart, Son Le, and James H. Wang.

9.6.2 Analysis of Sludge Treatment Portfolio


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Company Pyrolysis Sludge -

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Pretreatment Total


Hitachi 6 5 5 16

Sanyo 11 0 0 11

Mitsubishi 3 0 4 7

Hymo Corp 2 2 3 7

Kurita Water 5 0 1 6


Veolia 0 2 4 6

Novozymes 1 2 1 4

SCF Technologies 2 0 2 4

Hitachi 1 0 2 3

Council of Scientific and Industrial Research 0 2 0 2

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from US & Europe

Pyrolysis Miki Osamu(3), Sasaki Hidenori(3)

Sludge - Hydrolysis Delporte, Claude(2), Ikeda Kotaro(2), Nakayama Yoshio(2), Okuno Yasuyuki(2), Une Hiroshi(2), Wang, James H.(2)

Wang, James H.(2)

Sludge - Pretreatment

Daines-Martinez, Catherine(2), Funato Harurou(2), Kanetani Hideaki(2), Nakayama Yoshio(2)

Daines-Martinez, Catherine(2)

9.7 Category 4: Bioreactors and Microbial Technologies This category explores patents related to biological treatment of water. It includes the following five technology areas as subcategories:

• Bioreactors: broadly, any device in which a biological reaction or process is carried out

• Anaerobic: biological treatment of wastewater in the absence of oxygen to convert organic pollutants to (primarily) carbon dioxide and methane

• Aerobic: use of oxygen-dependent bacteria to convert organic pollutants to carbon dioxide and water

• Microbial: patents particularly concerned with the microbial aspects of biological water treatment (e.g., their cultivation)

• Biofuel (including biogas): production of a biofuel as part of a water treatment system or process

9.7.1 Key Findings Analysis of biological treatment-related patents is presented in Section 9.7.2 below. From that analysis, the following key findings are highlighted.


• Aerobic treatment approaches is the largest source of patenting activity found in this subcategory.

• Anaerobic and microbial technologies are also significant sources of activity.

• Biofuel and bioreactor-related patents are relatively small contributors of activity to the overall biological treatment category.


• The spread of biological treatment patents and applications across the three geographic regions is broadly similar to trends at the global level.

• Generally, the breakdown of different technologies across regional “portfolios” mirrors that at the global level. The only minor exceptions are as follows:

− Bioreactor-related technologies in the US, which have a slightly larger share (11 percent) of the portfolio than the global average (6 percent)

− Microbial technologies in Europe, which have a slightly smaller share (20 percent) than the global average (26 percent)




• Reflecting macro-level trends, biological treatment-related patenting activity in Japan has been decreasing across all categories, with the exception of biofuel technologies. This is one of only two subcategories in which Japanese patenting activity has increased.

• In other regions, patenting activity has been growing in all technology subcategories.

• In the US and Europe, the following trends can be observed:

− Growth is very strong in the biofuel subcategory.

− European patenting activity in the bioreactors subcategory has been very strong—growth in the US has been slower, but still significant.

− Patenting activity in the microbial subcategory has also been rapid.

On assignees …

• As in other categories, patenting activity is dominated by the typical large industrial players (see Table 9-10 for details).

• Notable is the presence of Sumitomo in the Japanese portfolio, as well as the Japanese companies Hitachi, Ebara, and Sharp in the US and European portfolios.

On inventors …

• Globally, leading inventors in biological treatment include Hibino Atsushi, Kataoka Katsuyuki, Date Masaki, Sawayama Shigeki, and Suzuki Tomio.

• Leading inventors on US and European patents include Kazuyuki Yamasaki, Christian Uphoff, and David Bagley.

9.7.2 Analysis of Biological Treatment Portfolio


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Company Biofuel/ Biogas Bioreactors

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Biological–Aerobic

Biological–Microbial Total


Hitachi 2 8 155 219 51 435

Kurita Water 9 2 80 128 58 277

Ebara Corp 9 7 85 97 28 226

Sumitomo 8 1 62 93 27 191

Mitsubishi 8 4 62 82 31 187


Hitachi 0 0 13 14 2 29

Suez Environment 2 2 9 10 3 26

Ebara Corp 2 1 10 10 2 25

Siemens Water 0 8 3 8 1 20

Sharp 0 0 5 6 8 19

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Category Leading inventors of patents from all

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US & Europe

Biofuel/Biogas Ashikaga Nobuyuki(4), Kida Kenji(3), Mizutani Hiroshi(3), Suzuki Tetsushi(3)

Bertolotto, Antonio(2); Böttcher, Joachim(2); Choate, Chris E.(2); Datschewski, Peter(2); Friedmann, Hans(2); Järventie, Jussi(2); Kamachi, Kazumasa(2); Le, Son(2); Li, Xiaomei(2)

Bioreactors Uemoto Hiroaki(7), Uphoff, Christian(4), Hu, Qiang(3), Liao, Zhimin(3), Livingston, Dennis(3), Morita Yoshihiko(3), Sato, Takaya(3), Zha, Fufang(3)

Uphoff, Christian(4); Hu, Qiang(3); Liao, Zhimin(3); Sato, Takaya(3); Zha, Fufang(3)

Biological - Anaerobic

Sawayama Shigeki(17), Suzuki Tomio(16), Date Masaki(15), Sumino Tatsuo(14), Isaka Kazuichi(13), Kataoka Katsuyuki(13), Komatsu Kazuya(13)

Bagley, David(7); Isaka, Kazuichi(7); Yamasaki, Kazuyuki(5); Böttcher, Joachim(4); Hansen, Conly L.(4); Yin, Bei(4)

Biological - Aerobic

Hibino Atsushi(23), Kataoka Katsuyuki(18), Date Masaki(17), Sawayama Shigeki(17), Suzuki Tomio(17)

Bagley, David(8); Isaka, Kazuichi(7); Mckinney, Jerry L.(7); Yamasaki, Kazuyuki(6); Koopmans, Richard J.(5); Yin, Bei(5)

Biological - Microbial

Yamazaki Kazuyuki(11), Takashima Yasutoshi(10), Ito Yoshitaka(8), Yamasaki, Kazuyuki(8), Uphoff, Christian(7)

Yamasaki, Kazuyuki(8); Uphoff, Christian(7); Bagley, David(6); Whitekettle, Wilson Kurt(5); Sorenson, Jr., Kent S.(4)

9.7.3 Landscape: Bioreactors Key Findings • Patents that focused on the design of bioreactors largely centered on improving efficiency—

suggesting a degree of maturity in this technology space. Strategies mentioned for improving efficiency include the following:

− flow path manipulation − gas injection − use of waste heat (from industrial sources)

• Analysis of IPC codes (see table below) highlights the use of the following component technologies:

− Packings, fillings, grids − Submerged filters − Trickle filters − Moving contact bodies

• Some patents tend to focus more on a specific application of a bioreactor (albeit with some design improvement as well); examples are listed below:

− Treating hydrocarbon/oil-contaminated water − Treating formaldehyde-contaminated water



FIGURE 9-16 Landscape of Bioreactor-Related Technologies 2005-2010



9.7.4 Landscape: Anaerobic Treatment Key Findings • The vast majority of patents in this category are for configurations that claim to increase

the efficiency of the process—highlighting the fairly developed nature of the technology space.

• Many patents relate to the coupling of aerobic and anaerobic fermentation (e.g., the IPC classification of “Aerobic and anaerobic processes” appears 54 times).

• Some technologies involved recycling the phosphates or nitrogen into fertilizer. A number of patents also mention the use of anaerobic processes for sludge treatment, and the resulting production of biogas—which can subsequently be used for energy recovery.

• Of those patents that specify particular applications:

− Nearly 40 percent mention both sewage and industrial wastewater as applications. − 25 percent mention only sewage as an application. − 20 percent specify only industrial applications. − Nearly 20 percent specify applications in treating food waste.

• Two applications mentioned in particular include treating wastewater from starch manufacturing and from semiconductor manufacturing.

• Sewage applications generally referred to denitrification.

• A large number of patents focused on design improvements, including the following:

− Simplification of the process − Increasing the speed of the process − Reducing the footprint of the process

9.8 Category 5: Filtration, Membranes, and Solids This category explores separation technologies. It includes the following six subcategories, characterized by separation mechanism or application:

• Filtration: physical removal of pollutants • RO osmosis: physical removal of pollutants by means of reverse osmosis • FO: physical removal of pollutants by means of forward osmosis • Separating solids: separation of solids from water • Waste processing/recycling: processing and/or recycling of waste from water treatment • Membrane (not osmosis): physical removal of pollutants using membranes by means other

than osmosis



FIGURE 9-17 Landscape of Anaerobic-Related Technologies 2005-2010

9.8.1 Key Findings Analysis of separation-related patents is presented in Section 9.8.2 below. From that analysis, the following key findings are highlighted.




• By far, the largest amount of patenting activity in separation-related technologies has been in the filtration subcategory.

• Waste processing/recycling has also seen a significant amount of patenting activity.

• Membranes, RO, and solids separation have all had much less patenting activity. However, when compared across the entire range of technology subcategories (i.e., beyond just the filtration category), they are still significant subcategories.

• By far, the smallest amount of activity has occurred in the FO subcategory.


• The spread of separation-technology–related patents and published applications across the three geographic regions is broadly similar to trends at the global level.

• Generally, the share of different separation technologies across regional “portfolios” mirrors that of the global level. The main exceptions are as follows:

− Filtration technologies, which make up a larger proportion of patents in both Europe (51 percent) and the US (48 percent), than in Japan (39 percent)

− Waste processing/recycling-related technologies, which make up a smaller proportion of patents in Europe (14 percent) and the US (16 percent), than in Japan (34 percent)


• Reflecting macro-level trends, separation-related patenting activity in Japan has been decreasing across all categories.

• In other regions, patenting activity has been growing in all technology subcategories, although activity in the US has grown substantially faster than in Europe.

• In the US, growth has been particularly strong in RO and the other membranes subcategories.

• Data is not available for FO–related patents at the regional level. However, growth globally has been extremely strong at around 80 percent (compound annual growth rate) for the shorter period from 2006 to 2009.

On assignees …

• Patenting activity is dominated by the typical large industrial players (see Table 9-12 for details), with the exception of Toray industries in the Japanese portfolio

• Also notable is the presence of Sanyo among the leading holders of nonJapanese patents.

On inventors …

• Globally, leading inventors in disinfection include Yamazaki Kazuyuki, Yoneda Takeshi, and Kataoka Katsuyuki.

• Leading inventors on US and European patents include Kazuyuki Yamasaki, Maurizio Moretto, Andreas Wawrla, and David Bagley.



9.8.2 Analysis of Separation Portfolio



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Company Filtration

Membrane (not

osmosis) Reverse osmosis

Forward osmosis

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Kurita Water 223 201 119 0 187 311 1041

Hitachi 271 165 15 0 133 309 893

Mitsubishi 185 164 29 0 126 283 787

Toray Industries 243 239 115 0 48 126 771

Fuji Clean Kogyo 183 79 6 2 40 193 503


Siemens Water 29 23 3 0 11 8 74

General Electric 27 14 15 0 3 4 63

Veolia 28 11 9 0 7 7 62

Suez Environment

17 11 2 0 9 8 47

Sanyo Electric Co

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from US & Europe

Filtration Yoneda Takeshi(40), Kadokawa Komei(22), Katsura Yousei(21), Kumami Kazuhisa(19), Nakayama Takeyuki(19)

Hsu, Maxwell(10); Umezawa, Hiroyuki(10); Bagley, David(8); Fritze, Karl(7); Moretto, Maurizio(7); Wawrla, Andreas(7)

Membrane (not osmosis)

Hamada Toyozo(25), Takemura Kiyokazu(24), Kadokawa Komei(21), Kumami Kazuhisa(17), Yoneda Takeshi(16)

Yamasaki, Kazuyuki(9); Zha, Fufang(7); Konishi, Takahisa(5); Langlais, Chrystelle(5)

Reverse Osmosis

Sato Yuya(14), Ikuno Nozomi(12), Yoneda Takeshi(12), Kawakatsu Takahiro(11), Kihara Masahiro(9)

Ando, Masaaki(5); Schmitt, Craig A.(5); Yin, Bei(5); Musale, Deepak A.(4); Brouwer, Jan-Willem(3); Daines-Martinez, Catherine(3); Efraty, Avi(3); Kawakatsu, Takahiro(3)

Separating Solids

Kataoka Katsuyuki(28), Katsura Yousei(18), Komatsu Kazuya(16), Akamatsu Kozo(10), Misawa Kihachiro(10), Rajiv Goel(10), Yoshida Teruhisa(10)

Robinson, Earl T.(5); Carapezzi, Giuliano(3); Dancuart Kohler, Luis P. F.(3); Hughes, Jonathan(3); Josse, Juan Carlos(3); Theodore, Marcus G.(3)

Waste Processing/ Recycling

Yamazaki Kazuyuki(42), Kataoka Katsuyuki(27), Yoshida Teruhisa(25), Hamada Toyozo(20), Hibino Atsushi(16), Mizutani Hiroshi(16)

Yamasaki, Kazuyuki(9); Bagley, David(8); Yin, Bei(5)

9.8.3 Landscape: Forward Osmosis Key Findings • Approximately one-third of the patents identified in this search were for an apparatus to carry

out FO in general, while another third were for membranes to be used in FO applications. The remaining 40 percent were for specific applications of FO technologies.



• Membrane forms identified include hollow fiber membranes, composite or ultra-thin membranes, and dynamic membranes.

• Spiral-wound membrane structures are the most frequently mentioned. Other structures mentioned include flat modules, tubular modules, and multiple spiral-wound assemblies.

• Five different categories of membrane materials are listed—see below for details.

• Seawater desalination is the only application listed in the IPC categorization.

FIGURE 9-20 Landscape of Forward Osmosis-Related Technologies 2005-2010

9.9 Category 6: Ecosystems, Domestic, and Miscellaneous This category explores a broad range of patents related to water treatment within the home as well as water treatment technologies’ interaction with the wider water ecosystem. It includes the following four subcategories:



• Aquifer: water treatment technologies that specifically mention sourcing water from or treating water for discharge to aquifers

• River/Lake/Wetland: water treatment technologies that specifically mention sourcing water from or treating water for discharge to rivers, lakes, or wetlands

• Home Applications: water treatment technologies that specifically mention having applications in a residential setting

• Other: miscellaneous water treatment-related technologies not categorized elsewhere

9.9.1 Key Findings Analysis of patents in the Ecosystem, Domestic, & Misc category is presented in Section 9.9.2 below. From that analysis, the following key findings are highlighted.


• The two categories of lakes/rivers/wetlands and home applications clearly dominate the landscape of this technology cluster. Patenting activity related to aquifers has been sparse.


• The spread of patents and applications across the three geographic regions is somewhat different from the spread for the whole patent portfolio, with the share of Japanese patents being significantly larger.

• There is substantial variation in the share of different technologies across regional portfolios. For example:

− The majority of aquifer-related patents are US.

− The US and Europe have smaller shares of river/lake/wetland-related patents (18 percent and 10 percent, respectively) than the global average (25 percent).

− The US and Europe have larger shares of home-application–related patents (29 percent and 34 percent, respectively) than the global average (20 percent).


• Reflecting macro-level trends, Japanese patenting activity in this category has been decreasing across all subcategories, while activity in Europe and the US has generally been increasing.

On assignees …


On inventors …

• Globally, leading inventors in disinfection include Katagai Nobuyoshi, Suzuki Eiichi, Kobayashi Hisahiro, and Yamazaki Kazuyuki.

• Leading inventors on US and European patents include Markus Baumann, Thomas DeBusk, and Bei Yin.



9.9.2 Analysis of Ecosystems, Domestic, and Miscellaneous Portfolio



0

200

400

600

800

1000

1200

1400

1600

1800

2000

Aquifer River/Lake/Wetland Home Applications

Japan EU US

-15%

-10%

-5%

0%

5%

10%

15%

20%

Com

poun

d A

nnua

l Gro

wth

Rat

e 20

00-

2009

EU

Japan

US




Company Aquifer Other River/Lake/

Wetland Home

Applications Total


Hitachi 0 183 72 49 304

Fuji Clean Kogyo 0 78 51 82 211

Kurita Water 0 104 53 23 180

Mitsubishi 0 86 58 15 159

Ebara Corp 0 48 47 5 100


Suez Environment 0 7 1 6 14

Veolia 0 9 1 2 12

General Electric 0 4 0 7 11

Hitachi 0 7 3 0 10

Siemens Water 0 5 1 4 10




from US & Europe

Aquifer Kerfoot, William B.(3), Kerfoot, William B.(3)

River/Lake/Wetland Ishii Koichi(10), Hayashida Keisei(9), Makino Masaki(8), Kataoka Katsuyuki(7), Kojima Hisao(7)

Debusk, Thomas A.(6); Abe, Norimitsu(3); Flowers, David A.(3); Hsu, Kenneth J.(3)

Home Applications Suzuki Eiichi(13), Katagai Nobuyoshi(12), Ichinari Takeshi(8), Niino Kiyonori(8), Sawayama Shigeki(7)

Yin, Bei(6); Donald, Hubbard H.(3); Duplessis, Samuel Vincent(3); Wang, James H.(3)

9.10 Summary Analysis in this report (e.g., Chapters 2 and 4) suggests that growth in water reuse in KSA will lead to increased demand for water treatment technologies. The current status of water treatment in KSA and the potential applications of water reuse suggest possible growth in demand for a wide range of technologies. Secondary treatment technologies of particular interest include CAS and MBR. Tertiary treatment technologies (particularly filtration and disinfection) will also be in demand. There could also be some interest in advanced treatment technologies (particularly low- and high-pressure membrane applications), including for niche industrial applications. Finally, interest in nutrient recovery, biosolids to energy, and sludge use or disposal technologies also appears likely.

Trends identified in the patent analysis in this chapter can help companies build an understanding of the state of innovation in different water treatment technology areas. These trends can identify technology areas that are maturing and therefore likely to be more suitable for application today. The trends can also identify technology areas that are emerging and therefore potentially attractive investments because they may be able to meet technology needs in the future. Table 9-15 summarizes the status of technology development implied by the patent trends identified in this analysis.



TABLE 9-15 Status of Key Technology Areas Relevant to KSA Water Treatment for Reuse Applications Implied by Patent Analysis

Emergent technology areas Relatively mature technology areas,

with strong patent growth rates Mature technology areas

FO RO Biofuels (including biogas) Pyrolysis of sludge Metals removal Ultrasound disinfection Pasteurization

Filtration Microbial treatment Phosphorus removal / recovery UV disinfection

Aerobic treatment Anaerobic treatment Nitrogen removal / recovery Bioreactors*

* Trends in Japan and the US suggest a mature technology, but growth in patenting in Europe has been strong.

Within the disinfection patent portfolio, oxidation and ozonation are the two dominant technologies, and therefore might be expected to be mature in nature. However, the growth rate of patenting activity in these two technologies areas is still rapid and suggests that the technologies have not yet reached a point of maturity—technology developers therefore should not ignore these areas. UV disinfection is an area of interest since its medium-sized patent portfolio is suggestive of a somewhat established and de-risked technology, while the rapid growth in patents suggests there is still significant technology development available to leverage commercially. Finally, at the higher-risk end of the spectrum, ultrasound disinfection and pasteurization both appear to be emergent technology areas—with low numbers of patents today, but rapid growth. Opportunities to establish a relatively early technology position may therefore exist.

Filtration is a major area of patenting activity identified in this intellectual property landscape—by far the largest at the technology category level. Growth rates in patenting activity suggest that this technology area is far from reaching maturity. Osmosis technologies (both RO and FO) are clearly more emergent. Patenting activity within FO is particularly indicative of an emergent space. For example, since many patents cover device design, it would appear that no dominant design has been achieved. A significant amount of patenting activity is related to the membranes used for FO, highlighting a particular focus area for potential technology development.

Even within mature technology areas, technology development continues. Analysis of patents within these categories suggests that most of the activity pertains either to small improvements in a proven technology’s efficiency or to adaption of technologies to increasingly specialized applications (e.g., treatment of wastewater from nuclear power plants). Businesses and other stakeholders need to maintain an awareness of this kind of technology development, particularly efficiency improvements, to ensure that their offerings remain competitive (in the case of technology suppliers) or are sourcing the most cost-effective option (in the case of technology buyers).

In addition to the technology-specific findings outlined above, it is worth noting that innovative activity in water treatment technologies is diffuse—while there are a number of large companies that are leading patent assignees, they ultimately hold only a very small proportion of the overall patent portfolio. The remaining patents are held by a very large number of companies with typically only a small number of patents. This suggests that a partnership-based or open innovation approach to technology development is critically important in this sector. Such an approach not only enables access to a broader array of technology options, but also helps established players to mitigate technology risks through maintenance of a balanced portfolio of innovations.

9.11 References Japan Patent Office (2011). Annual Report 2010. Tokyo.

STRATEGIC STUDY

Acronyms and Abbreviations

AA acrylamide AD Adsorption Desalination AD Anno Domini AEM anion exchange membrane AH Anno Hegirae AMBR Anaerobic Migrating Blanket Reactor AnMBR Anaerobic Membrane Bioreactor AOB ammonia oxidizing bacteria AOP advanced oxidation process ARR aquifer recharge and recovery ARROWTM Advanced Reject Recovery of Water ASR aquifer storage and recovery ASTR aquifer storage, transfer, and recovery atm atmosphere AWTF Advanced Wastewater Treatment Facility AWWA American Water Works Association (USA) bbl barrel BNR biological nutrient removal BOD biochemical oxygen demand bpd barrel per day BTEX benzene, toluene, ethylbenzene, and xylenes BWRO brackish water reverse osmosis cal/yr calories/year CAS conventional activated sludge CD capacitive deionization CDPH California Department of Public Health (USA) CDSI Central Department of Statistics and Information CDT Capacitive Deionization Technology Systems, Inc. CEC compound of emerging concern CEE The Consortium for Energy Efficiency CEM cation exchange membrane CFR Code of Federal Regulations (USA) CFU coliform forming unit CIP clean-in-place COD chemical oxygen demand CT contact time CWOA closed-water open air $ U.S. dollar °C degrees Celsius °F degrees Fahrenheit DBP disinfection byproduct

ACRONYMS AND ABBREVIATIONS

STRATEGIC STUDY

DC direct current DDD diffusion-driven desalination DEMON® DEamMONification DO dissolved oxygen DOC dissolved organic carbon DWPI Derwent World Patent Index € Euro ECRA Electricity and Cogeneration Regulatory Authority EDC endocrine disrupting compound EDM electrodialysis metathesis EDR electro-dialysis reversal EfOM effluent organic matter EMCV Encephalomyocarditis virus EMWD Eastern Municipal Water District EU European Union FAO Food and Agriculture Organization of the United Nations FC fecal coliform FO forward osmosis FOG fats, oil, and grease g carbon/m2/day grams carbon per square meter per day g/L grams per liter GER General Environmental Regulations and Rules for Implementation gfd gallons per square foot per day GHG greenhouse gas GOR gained-output ratio gpd gallons per day gpm gallons per minute GWI Global Water Intelligence GWRS Groundwater Replenishment System ∆P hydraulic pressure HAA haloacetic acid HDH humidification-dehumidification HIDA Al-Hassa Irrigation and Drainage Authority HIX-NF hybrid ion exchange-nanofiltration HRT hydraulic retention time I&C instrumentation and control IFAS Integrated Fixed Film Activated Sludge IPC International Patent Classification ITC-WGT Institute for Technical Chemistry, Water, and Geotechnology Division IWRM integrated water resource management IX ion exchange JCBU Jeddah City Business Unit KACST King Abdulaziz City for Science and Technology KAIA King Abdulaziz International Airport KAUST King Abdullah University of Science and Technology kgal 1,000 gallons kHz kilohertz KICP KAUST Industrial Collaboration Program


STRATEGIC STUDY

kJ/m2 kiloJoules per square meter km kilometer km2 square kilometer kPa kiloPascal KSA Kingdom of Saudi Arabia kW kilowatt kWh kilowatt-hour kWh/m3 kilowatt-hours per cubic meter L liter L/capita/ day liter per capita per day L/m2/hr liters per square meter per hour L/min liters per minute L/s liters per second L/s/m liters per second per meter LCC life cycle cost μg/L micrograms per liter μm micrometer μM micromoles M million m2/d square meters per day m2/g square meters per gram m3/d cubic meters per day m3/y cubic meters per year MAA methacrylic acid MABR Membrane Aerated Biofilm Reactor MAR managed aquifer recharge MBfR Membrane Biofilm Reactor MBR membrane bioreactor MD membrane distillation MDC microbial desalination cell MED multi–effect distillation MENA Middle East and North Africa MEPCO Middle East Paper Company MF microfiltration MFC microbial fuel cell mg/kg milligrams per kilogram mg/L milligrams per liter mgd million gallons per day mg-min/L milligrams per minute per liter mL milliliters mL/min milliliters per minute mm millimeters MOA Ministry of Agriculture MOH Ministry of Health MOMRA Ministry of Municipal and Rural Affairs MOWE Ministry of Water and Electricity MPN most probable number MSABPTM Multi-Stage Activated Biological Process MSF multi–stage flash MUS managed underground storage NASA National Aeronautics and Space Administration (USA) NDMA N-nitrosodimethylamine


STRATEGIC STUDY

NF nanofiltration NGO non-governmental organization NOB nitrite oxidizing bacteria NOM natural organic matter NPV net present value NTU Nephelometric Turbidity Unit NUS National University of Singapore NWC National Water Company ∆п osmotic pressure gradient O&M operation and maintenance ORE operational recovery efficiency PAA peracetic acid PAC powdered activated carbon PAH polyaromatic hydrocarbon PCB polychlorinated biphenyl PERSGA Regional Organization for the Conservation of the Environment of the

Red Sea and Gulf of Aden pKa acid dissociation constant PME Presidency of Meteorology and Environment ppm parts per million ppt parts per thousand PRO pressure restrained osmosis P-RoC Phosphorus Recovery from Wastewater by Crystallization PV photovoltaic PVC polyvinyl chloride PW present worth R&D research and development RCBU Riyadh City Business Unit RCJY Royal Commission for Jubail and Yanbu RE Recovery Efficiency RECOFI Regional Commission for Fisheries RNA ribonucleic acid RO reverse osmosis ROI Rules of Implementation ROPME Regional Organization for the Protection of the Marine Environment RQTSE Reuse Quality Treated Sewage Effluent SAL-PROC™ Salt Solidification and Sequestration SASO Saudi Arabian Standards Organization SAT soil-aquifer treatment Saudi ARAMCO Saudi Arabian Oil Company SBR sequencing batch reactor SE storage efficiency SHARONTM/ ANOMMOX® ANerobic AMMonia Oxidation Process SHARON™ Single Reactor High-activity Ammonia Removal Over Nitrite SPARRO Slurry Precipitation and Reverse Osmosis SR Saudi Riyal SRE system recovery efficiency SRT solids retention time SS suspended solids STP sewage treatment plant


STRATEGIC STUDY

SVOC semivolatile organic compound SWCC Saline Water Conversion Corporation TDH total dynamic head TDS total dissolved solids TFN thin film nanocomposite THM trihalomethane TiO2 titanium-based advanced oxidation TKN total Kjeldahl nitrogen TMP trans-membrane pressure TN total nitrogen TOC total organic carbon TPH total petroleum hydrocarbon TSE treated sewage effluent TSS total suspended solids TWPS Tactical Water Purification System µhmos/cm mircromhos per centimeter UAE United Arab Emirates UASB upflow anaerobic sludge blanket UCT University of Cape Town UF ultrafiltration USBR U.S. Bureau of Reclamation (USA) USEPA U.S. Environmental Protection Agency UV AOP ultraviolet advanced oxidation process UV ultraviolet V volt VRM Vacuum Rotation Membrane W/L watts per liter W/m3 watts per cubic meter WAS waste activated sludge WEF Water Environment Federation WERF Water Environment Research Foundation WHO World Health Organization WRA Water Regulatory Authority WTP water treatment plant WWTP wastewater treatment plant ZDD™ Zero Discharge Desalination ZLD zero liquid discharge

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