wastewater management framework for the city of cali ... · table of content sustainable water...

Sustainable Water Improves Tomorrow’s Cities’ Health - SWITCH Project

Cali, A Demonstration City

Wastewater Management Framework for the city of Cali,

Colombia A paradigm shift in the wastewater pollution control

Cali, January, 2009

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This document has been done by CINARA - Instituto de Investigación y Desarrollo en Abastecimiento de Agua, Saneamiento Ambiental y Conservación del Recurso Hídrico of Universidad del Valle in the framework of the “Sustainable Water Improves Tomorrow’s Cities’ Health” SWITCH project. This report has been done with the support of UNESCO-IHE and the institutions involved with the management of water resources, sanitation and environmental authorities at national, regional and local level. The following people took part in the development of this report Alberto Galvis, MSc Sanitary Engineer, SWITCH Project coordinator in

Universidad del Valle. Diana A. Cardona, Sanitary Engineer, Cinara Institute Diana A. Zambrano Sanitary Engineer, Cinara Institute Ana M. Otero Sanitary Engineer, Cinara Institute Anny Y. Marínez Sanitary Engineer, Cinara Institute Diana P. Bernal, Sanitary Engineer, Cinara Institute Gloria A. Raffo, Student of Biology, Universidad del Valle Ricardo L. Martínez Student of Chemistry, Engineer Universidad del Valle Liliana M. Salazar Student of Sanitary Engineer, Universidad del Valle

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Sustainable Water Improves Tomorrow’s Cities’ Health SWITCH Project iii

TABLE OF CONTENT

1. INTRODUCTION ...................................................................................................... 1-1

2 THE CITY OF CALI IN THE CONTEXT OF THE CAUCA RIVER BASIN... 2-1 2.1 CAUCA RIVER BASIN ..............................................................................................2-1 2.2 UPPER CAUCA RIVER BASIN.................................................................................2-2 2.3 MUNICIPALITY OF CALI.........................................................................................2-7 2.3.1 General characteristics ...............................................................................................2-7 2.3.2 Demography...............................................................................................................2-9 2.3.3 Physical Aspects ......................................................................................................2-10 2.3.4 Socioeconomic Aspects ...........................................................................................2-11 2.3.5 Public services..........................................................................................................2-11 2.3.6 Hydrographic Aspects..............................................................................................2-13

3 THE SEWAGE SYSTEM OF THE CITY OF CALI ............................................. 3-1 3.1 HISTORICAL EVOLUTION OF THE SEWAGE SYSTEM.....................................3-1 3.1.1 Sewage at the beginning of the 20th century .............................................................3-1 3.1.2 First sewer system master plans.................................................................................3-1 3.1.3 Wastewater treatment.................................................................................................3-2 3.2 SEWAGE SYSTEM INFRAESTRUCTURE..............................................................3-3 3.2.1 Components ...............................................................................................................3-4 3.2.2 Drainage systems .......................................................................................................3-4 3.2.3 Industrial wastewater discharges .............................................................................3-10 3.2.4 Final wastewater discharge points from the city of Cali to Cauca River.................3-11 3.2.5 Wastewater Treatment Plant - WWTP.....................................................................3-13

4 WASTEWATER POLLUTION CONTROL IN COLOMBIA AND THE UPPER CAUCA RIVER BASIN .............................................................................. 4-1

4.1 HISTORICAL EVOLUTION IN COLOMBIA...........................................................4-1 4.1.1 Institutional framework..............................................................................................4-1 4.1.2 Policies and regulations .............................................................................................4-2 4.1.3 Pollution control strategies from policies and regulation ..........................................4-7 4.2 WASTEWATER POLLUTION CONTROL IN THE UPPER CAUCA RIVER

BASIN ........................................................................................................................4-14 4.2.1 Background ..............................................................................................................4-14 4.2.2 Contaminant load discharges into the Cauca River .................................................4-15 4.2.3 Wastewater management of municipalities of Valle del Cauca department ...........4-21 4.2.4 Wastewater management of other municipalities ....................................................4-22 4.2.5 Industry wastewater management ............................................................................4-23 4.2.6 Water quality objectives of the Cauca River ...........................................................4-24 4.3 ANALYSIS ................................................................................................................4-26 4.3.1 Wastewater pollution control in Colombia ..............................................................4-26 4.3.2 Pollution control for industrial wastewater ..............................................................4-29

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4.3.3 Pollution control in the agricultural sector...............................................................4-29 4.3.4 Wastewater pollution control in the Upper Cauca River Basin and city of Cali .....4-29

5 PARADIGM SHIFT IN WATER MANAGEMENT IN URBAN AREAS........... 5-1 5.1 CONCEPTS..................................................................................................................5-1 5.1.1 Water Quality Requirements......................................................................................5-1 5.1.2 Sustainability..............................................................................................................5-2 5.1.3 Integrated Water Resource Management ...................................................................5-2 5.1.4 Urban water................................................................................................................5-3 5.1.5 Cleaner Production.....................................................................................................5-4 5.1.6 Multiple uses of water................................................................................................5-7 5.2 PARADIGM SHIFT FOR THE CITY OF TOMORROW..........................................5-7 5.3 SOME STRATEGIES FOR POLLUTION CONTROL IN THE URBAN

WATER CYCLE IN THE RIVER BASIN CONTEXT ..............................................5-8 5.3.1 Household ..................................................................................................................5-9 5.3.2 Industry ....................................................................................................................5-12 5.3.3 Water supply system ................................................................................................5-13 5.3.4 Drainage of rainwater...............................................................................................5-16 5.3.5 Treatment and reuse of wastewater..........................................................................5-17 5.3.6 Solid waste management..........................................................................................5-22 5.3.7 Basin.........................................................................................................................5-22 5.4 SOCIO-CULTURAL AND INSTITUTIONAL ASPECTS ......................................5-24 5.5 FINANCIAL AND ECONOMIC ASPECTS ............................................................5-26

6 POLLUTION CONTROL OF CALI CITY VERSUS THE NEW PARADIGM IN THE COMPONENTS URBAN WATER CYCLE ............................................ 6-1

6.1 HOUSEHOLD..............................................................................................................6-1 6.2 INDUSTRY..................................................................................................................6-2 6.3 WATER SUPPLY SYSTEM .......................................................................................6-3 6.4 WASTEWATER COLLECTION AND CONVEYANCE..........................................6-4 6.5 STORMWATER DRAINAGE SYSTEMS .................................................................6-4 6.6 WASTEWATER TREATMENT AND REUSE..........................................................6-5 6.7 RIVER BASIN .............................................................................................................6-7 6.8 TRANSVERSAL ASPECTS .......................................................................................6-7 6.8.1 SOCIAL, INSTITUTIONAL AND REGULATORY COMPONENT .....................6-7 6.8.2 FINANCIAL AND ECONOMIC SYSTEM .............................................................6-8

7 PROPOSAL OF WASTEWATER POLLUTION CONTROL STRATEGIES FOR THE CITY OF CALI........................................................................................ 7-1

7.1 GENERAL OVERVIEW .............................................................................................7-1 7.2 PROPOSED STRATEGIES BY INSTITUTIONS......................................................7-3 7.2.1 Strategies and projects proposed by the institutions in regional and local plans .......7-4

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7.2.2 Studies of alternatives and Proposals Made in the Three Sectors of the City of Cali7-8 7.2.2.1 Sector 1 Drainage area to WwTP-C .....................................................................7-8 7.2.2.2 Sector 2 South drainage system..........................................................................7-15 7.2.2.3 Sector 3 Expansion area .....................................................................................7-16

7.3 PROPOSAL OF STRATEGIES IN THE SHIFT PARADIGM FRAMEWORK .....7-21 7.3.1 Sector 1 Drainage area to WwTP-C.........................................................................7-23 7.3.2 Sector 2 South Drainage System..............................................................................7-41 7.3.3 Sector 3 expansion area............................................................................................7-62

8. BIBLIOGRAPHY ...................................................................................................... 8-1

ANNEXES

LIST OF FIGURES

Figure 2.1 Cauca River basin general location....................................................................2-1

Figure 2.2 Cauca River basin general classification ...........................................................2-2

Figure 2.3 Multiple Uses Water - Cauca River ...................................................................2-3

Figure 2.4 Dissolved oxygen profile in the Cauca River ...................................................2-5

Figure 2.5 Water quality in the Cauca River according to ICAUCA index........................2-6

Figure 2.6. Geographic location City of Cali ......................................................................2-7

Figure 2.7 Map of the Municipality of Cali. .......................................................................2-8

Figure 2.8 Location of existing and future urban areas in the Municipality of Cali ...........2-9

Figure 2.9 Cross section of the Municipality of Cali ........................................................2-10

Figure 3.1 Drainage systems in the city of Cali. .................................................................3-5

Figure 3.2 Formation of the South Drainage Pluvial System..............................................3-6

Figure 3.3 South Channel discharge point to Cauca River..................................................3-7

Figure 3.4 Margen Izquierdo collector discharge point ......................................................3-7

Figure 3.5 Central collector discharge point .......................................................................3-8

Figure 3.6 Regulation Systems..........................................................................................3-10

Figure 3.7 BOD load discharges to Cauca River basin in the Valle del Cauca Department. Year 2007. Section Salvajina-La Virginia........................................3-10

Figure 3.10 BOD load contribution of the final discharges to Cauca River .....................3-12

Figure 3.11 General scheme Cañaveralejo Wastewater Treatment Plant (WwTP-C) ......3-13

Figure 3.12 Average influent flow WwTP-C during year 2003 to 2007...........................3-13

Figure 3.13 Water line scheme..........................................................................................3-14

Figure 3.14 Sludge line scheme.........................................................................................3-14

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Figure 4.1 Colombian institutional structure for the management of the water resources ..................................................................................................................4-3

Figure 4.2 Flow chart of the investment prioritization........................................................4-8

Figure 4.3 BOD load discharged to Cauca River. Section: Salvajina – La Virginia. .......4-16

Figure 4.4 BOD load discharges in the Cauca River basin by different commercial, industrial and domestic sectors in the Cauca department ......................................4-17

Figure 4.5 BOD load discharged in the department of Cauca. Year 2003........................4-17

Figure 4.6 BOD load discharges to Cauca River basin in the Valle del Cauca department in year 2006 ........................................................................................4-18

Figure 4.7 Total BOD load discharged to the Cauca River from Cali city .......................4-19

Figure 4.8 Loads of domestics and Industrial Wastewater in the Margen Izquierdo Collector ................................................................................................................4-20

Figure 4.9 Loads of domestics and Industrial Wastewater in the Floralia Pumping Station ....................................................................................................................4-21

Figure 4.10 Time variation of the BOD load in the Zanjón Oscuro and Guachal rivers tributaries. Monitoring campaign held July 11-15, 2006. .....................................4-23

Figure 4.11 Variation in the BOD and DO concentrations in the Cauca River at the Base Scenarios for the Proposal Cauca River Water Quality Objectives Proposed by CVC. La Balsa – Anacaro Section...................................................4-25

Figure 5.1 Urban water cycle. .............................................................................................5-4

Figure 5.2 Schematic representation of the 3-Step Strategic Approach to wastewater management .............................................................................................................5-5

Figure 5.3 Integrated water management at core settlements .............................................5-9

Figure 5.4 Efficient water use in the household ................................................................5-10

Figure 5.5 Typical grey water production and toilet flushing requirements in a college..5-11

Figure 5.6 Schematic of urban water cycle depicting sub-system spheres of influences..5-14

Figure 5.7 Conventional urban drainage vs. SUDS ..........................................................5-17

Figure 5.8 SUDS Options..................................................................................................5-18

Figure 5.9 Economies and dis-economies of scale in water and sanitation systems.........5-19

Figure 5.10 Examples of options for the reduction of viral, bacterial an protozoan pathogens by different combinations of health protection measures that achieve the health based target of 10-6 DALYs per person per year ....................5-22

Figure 5.11 Three types of management system and the context in which they operate. Arrows show hypothetical direction of relationships and response.........5-25

Figure 5.12 Emission reduction vs marginal cost .............................................................5-27

Figure 5.13 Towards the spaceship economy: three stages in eco-efficiency...................5-29

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Figure 6.1 Water Consumption per Household in the City of Cali. ....................................6-2

Figure 6.2 DO in Cauca River. Summer conditions............................................................6-6

Figure 7.1 Influence sectors of the proposed strategies for the management of wastewater in the city of Cali ..................................................................................7-2

Figure 7.2 Pilot plant located in the WwTP-C ..................................................................7-11

Figure 7.3 Pilot plant of the contact stabilization..............................................................7-11

Figure 7.4 Pilot plant of the conventional activated sludge ..............................................7-12

Figure 7.5 Proposed drinking water layout and supply zones in the sector Cali Jamundí..................................................................................................................7-17

Figure 7.6 Proposed drainage sector in the Cali-Jamundí sector ......................................7-18

Figure 7.7 Scheme of interactions between activities proposed vs time ...........................7-22

LIST OF TABLES

Table 2.1 Facts and figures of Cali......................................................................................2-9

Table 2.2 Installed capacity and production of drinking water in Cali .............................2-12

Table 3.1 Pumping stations in the city of Cali ....................................................................3-4

Table 3.2 Comparison between design and characteristics - Pondaje Lagoons ..................3-9

Table 3.3 BOD an TSS load produced by some economical sectors ................................3-11

Table 3.4 Flow and BOD load discharges from the final wastewater discharge points in the three drainage systems in Cali. Year 2005 ..................................................3-12

Table 3.5 Comparison of design and current operation parameters in the WwTP-C........3-15

Table 4.1 Chronological history of the main legal standards related to waste management .............................................................................................................4-4

Table 4.2 Main CONPES “guidelines policy documents” related with the wastewater management .............................................................................................................4-5

Table 4.3 Wastewater discharge limits to open water bodies. Decree 1594/1984, Article 72 ...............................................................................................................4-11

Table 4.4 Wastewater discharge limits to public sewers. Decree 1594/1984, Article 72 ...........................................................................................................................4-12

Table 4.5 Standard admissible concentrations for the control of hazardous substances discharge. Decree 1594/1984, Article 74 ..............................................................4-12

Table 4.6 Flows and BOD and TSS load discharges measured in the final wastewater discharge points. Years 2006 - 2007......................................................................4-18

Table 4.7 Industrial discharges that generate a minor amount of contaminant load to the affluent at the WwTP-C...................................................................................4-20

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Table 4.8 Municipalities of the Valle del Cauca Department having WwTP ...................4-21

Table 4.9 Wastewater treatment status in the municipalities of Cauca located in the Cauca River Basin – 2005 .....................................................................................4-22

Table 4.10 Pollution control strategies for some industries located in the Upper Cauca River Basin ............................................................................................................4-24

Table 4.11 Contaminating load reduction goals – Resolution 0686 of November 20, 2006 - CVC............................................................................................................4-26

Table 5.1 Definitions related to water quality and pollution control...................................5-2

Table 5.2 Comparison of water management of the city of today and that in the city of tomorrow..................................................................................................................5-8

Table 5.3 Municipal wastewater reuse categories and possible restrictionsa....................5-20

Table 6.1 Comparison of recorded hazardous substance’s values (2006), in the South Drainage System, with the Colombian regulation. ..................................................6-3

Table 7.1 Inventory of regional and local plans ..................................................................7-4

Table 7.2 Strategies proposed by the institutions for wastewater management considering the urban water cycle ...........................................................................7-5

Table 7.3 Estimated reduction in flows and BOD in each drainage system 2007-2016 .....7-6

Table 7.4 Perspectives for total influent and effluent’s flows, and discharge loads from WwTP-C and WwTP-S as a result of the decontamination plan formulated in the PSMV..........................................................................................7-7

Table 7.5 Alternative studies and proposals of water management in the city of Cali .......7-9

Table 7.6 Summary of physical characteristics in the studied alternatives at lab scale for secondary treatment in WwTP-C.....................................................................7-10

Table 7.7 Summary results of each alternative in terms of effluent quality and removal efficiencies...............................................................................................7-10

Table 7.8 Effluent quality and removal efficiencies in the pilot scale plant contact stabilization............................................................................................................7-12

Table 7.9 Operational loads of the pilot activated sludge systems: contact stabilization and conventional ....................................................................................................7-13

Table 7.10 Global requirements and useful area for the treatment ...................................7-13

Table 7.11 Summary of proposed drinking water alternatives..........................................7-20

Table 7.12 Proposal of short, medium and long term actions in “Household” component. Sector 1: Drainage area to WwTP-C .................................................7-23

Table 7.13 Proposal of short, medium and long term actions in “Industry” component. Sector 1: Drainage area to WwTP-C .................................................7-24

Table 7.14 Proposal of short, medium and long term actions in “Water supply system” component. Sector 1: Drainage area to WwTP-C....................................7-26

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Table 7.15 Proposal of short, medium and long term actions in “wastewater collection” component. Sector 1: Drainage area to WwTP-C...............................7-27

Table 7.16 Proposal of short, medium and long term actions in “stormwater collection” component. Sector 1: Drainage area to WwTP-C...............................7-30

Table 7.17 Proposal of short, medium and long term actions in “wastewater treatment and disposal” component. Sector 1: Drainage area to WwTP-C...........................7-32

Table 7.18 Proposal of short, medium and long term actions in “solid waste management” component. Sector 1: Drainage area to WwTP-C ..........................7-34

Table 7.19 Proposal of short, medium and long term actions in “river basin” component. Sector 1: Drainage area to WwTP-C .................................................7-37

Table 7.20 Proposal of short, medium and long term actions in “Household”component. Sector 2: South Drainage System..................................7-41

Table 7.21 Proposal of short, medium and long term actions in “Industry” component. Sector 2: South Drainage System ......................................................7-43

Table 7.22 Proposal of short, medium and long term actions in “Water supply system” component. Sector 2: South Drainage System.........................................7-44

Table 7.23 Proposal of short, medium and long term actions in “wastewater collection” component. Sector 2: South Drainage System....................................7-47

Table 7.24 Proposal of short, medium and long term actions in “stormwater collection” component. Sector 2: South Drainage System....................................7-50

Table 7.25 Proposal of short, medium and long term actions in “wastewater treatment and disposal” component. Sector 2: South Drainage System................................7-53

Table 7.26 Proposal of short, medium and long term actions in “solid waste management” component. Sector 2: South Drainage System ...............................7-55

Table 7.27 Proposal of short, medium and long term actions in “River Basin” component. Sector 2: South Drainage System ......................................................7-58

Table 7.28 Proposal of short, medium and long term actions in “Household” component. Sector 3: Expansion area....................................................................7-63

Table 7.29 Proposal of short, medium and long term actions in “Industry” component. Sector 3: Expansion area....................................................................7-64

Table 7.30 Proposal of short, medium and long term actions in “Stormwater collection” component. Sector 3: Expansion area .................................................7-65

Table 7.31 Proposal of short, medium and long term actions in “Water supply system” component. Sector 3: Expansion area......................................................7-67

Table 7.32 Proposal of short, medium and long term actions in “Treatment and reuse of wastewater” component. Sector 3: Expansion area...........................................7-67

Table 7.33 Proposal of short, medium and long term actions in “Solid waste management” component. Sector 3: Expansion area ............................................7-68

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Table 7.34 Proposal of short, medium and long term actions in “River basin” component. Sector 3: Expansion area....................................................................7-68

Abbreviations

Sustainable Water Improves Tomorrow’s Cities’ Health SWITCH Project xi

ABBREVIATIONS

ACOPI Asociación Colombiana de las Micro, Pequeñas y Medianas Empresas - Colombian Association of Micro, Small and Medium Enterprises

ANDESCO : Asociación Nacional de Empresas de Servicios Públicos Domiciliarios y Actividades Complementarias e Inherentes - National Association of Public Service Company domiciliary and ancillary activities and inherent

ASOCARS : Asociación de Corporaciones Autónomas Regionales y de Desarrollo Sostenible - Association of Regional Autonomous Corporations and Sustainable Development

BECOLSUB : Ecological process of coffee in Colombia BOD : Biochemical Oxygen Demand CAR : Corporaciones Autónomas Regionales - Autonomous Regional

Corporations CARDER : Corporación Autónoma Regional de Risaralda - Autonomous Regional

Corporation of the Risaralda CEDE : Centro de Estudios sobre Desarrollo Económico - Center for Studies on

Economic Development CEPAL : Comisión Económica para América Latina y el Caribe - United Nations

Economic Commission for Latin America and the Caribbean (UNECLAC)CINARA : Instituto de Investigación y Desarrollo en Abastecimiento de Agua,

Saneamiento Ambiental y Conservación del Recurso Hídrico - Institute for the Research of Water Supply, Sanitation and Water Resource Conservation

CNRN : Código Nacional de Recursos Naturales Renovables y de Protección al Medio Ambiente - National Code for Natural Resource Management and Environmental Protection

CONPES : Consejo Nacional de Política Económica y Social – National Council of Social and Economic Policies

CORNARE : :

Corporación Autónoma Regional de las Cuencas de los Rios Negro y Nare - Autonomous Regional Corporation of the Negro and Nare river basins

CP : Cleaner Production CRA : Comisión de Regulación de Agua Potable y Saneamiento Básico -

Regulatory Commission for Water and Sanitation COD Chemical Oxygen Demand CRQ : Corporación Autónoma Regional del Quindío - Autonomous Regional

Corporation of the Quindío department CSO Combined Sewer Overflows CVC : Corporación Autónoma Regional del Valle del Cauca – Autonomous

Regional Corporation of the Valle del Cauca DAGMA : Departamento Administrativo de Gestión del Medio Ambiente -

Administrative Department for Environmental Management DALY : Disability Adjusted Life Years Lost DANE : Departamento Administrativo Nacional de Estadística - National -

Administrative Statistics Department DAPM : Departamento Administrativo de Planeación Municipal – Municipal

Abbreviations

Sustainable Water Improves Tomorrow’s Cities’ Health SWITCH Project xii

Administrative Planning Department DO : Dissolved Oxygen DSSs : Decision Support Systems EcoSanRes : Ecological Sanitation Research EDS : East Drainage System EMCALI : Empresas Municipales de Cali - Cali’s Municipal Water Service Company EMRU : Empresa de Renovación Urbana - Municipal Urban Renovation Company EMSIRVA : Empresa de Servicio Público de Aseo de Cali - Solid Waste Municipal

Service Company EPA : Environmental Protection Agency EPSA : Energy company of the Pacific ERT Empresa Regional de Telecomunicaciones del Valle del Cauca - Regional

Telecommunication Company of the Valle del Cauca department FSW Free surface wetland FAO : Food and Agriculture Organization GWP : Global Water Partnership HDI : Human Development Index ICAUCA : Índice Fisicoquímico de Calidad del Agua adaptado a las Condiciones del

Río Cauca - Physical chemical water quality index adapted to the Cauca river conditions

ICM : Integrated Catchments Management INDERENA : Instituto de Recursos Naturales y del Ambiente - National Institute of

Natural and Renewable Environmental Resources INGESAM : Ingeniería de Saneamiento Ambiental, Ingenieros Constructores -

Environmental Sanitation Engineering, Engineers Constructors IRBM : Integrated River Basin Management ISO : International Organization for Standardization IUWM : Integrated Urban Water Management IWMI International Water Management Institute IWRM : Integrated Water Resource Management MLSS Mixed Liquor Suspended Solids MAVDT : Ministerio de Ambiente, Vivienda y Desarrollo Territorial - Ministry of the

Environment, Housing and Territorial Development MHCP : Ministerio de Hacienda y Crédito Público MDBC : Murray Darling Basin Commission NDS : North-West Drainage system OECF Overseas Economic Cooperation Fund PAHO : Pan American Health Organization PGIRS : Plan de Gestión Integral de los Residuos Sólidos - Plan for the Integrated

Management of Solid Waste PMC : Proyecto de Modelación del Río Cauca- Cauca River Modelling Project PME Programa de Modernización Empresarial - Entrepreneurial Modernization

Program

Abbreviations

Sustainable Water Improves Tomorrow’s Cities’ Health SWITCH Project xiii

POT : Plan de Ordenamiento Territorial - Land Use Planning PPP : Polluter pays” principle PSMV : Plan de Saneamiento y Manejo de Vertimientos - Plan for Sanitation and

Management of Wastewater Discharges QRMA : Quantitative Microbial Risk Assessment RAS : Reglamento Técnico del Sector de Agua Potable y Saneamiento Básico -

Technical Regulation for Water and Sanitation sectors RGS : Red de Gestores Sociales - Social Network Managers RTC : Real Time Control SAMTAC : South American Technical Advisory Committee SDS : South Drainage System SIGAM : Sistema de Gestión Ambiental Municipal - Environmental municipal

management system SINA : Sistema Nacional Ambiental - Environmental National System SSPD : Superintendencia de Servicios Públicos Domiciliários - Superintendent of

Public Home Services SUDS : Sustainable Urban Drainage Systems SWITCH Sustainable Water Improves Tomorrow’s Cities’ Health TELECOM Servicio de telecomunicaciones, telefonía nacional e internacional -

Telecommunications service, national and international telephony of Colombia

TIDDD : Tool to Inform Debates, Dialogues & Deliberations TTO Tubería de Transmisión Oriental-Oriental Transmision Pipe TPA Tratamiento Primario Avanzado - Advanced Primary Treatment TTNV Tubería de Transmisión de Navarro- Navarro Transmission Pipe TSS : Total Suspended Solids TVA : Tennessee Valley Authority Model UASB : Upflow Anaerobic Sludge Blanket UN : United Nations UNDP : United Nations Development Programme UNEP : United Nations Environment Programme UNESCO-IHE

: Institute for Water Education

WHO : World Health Organization WMDS Wastewater Management Decentralised Systems UWM Urban Water Management WMU : Water Management Units WwTP : Wastewater Treatment Plant WwTP-C : Cañaveralejo Wastewater Treatment Plant

Chapter 1 Introduction

Sustainable Water Improves Tomorrow’s Cities’ Health SWITCH Project 1-1

1 INTRODUCCIÓN The environmental impact of human development activities is very serious and simply getting worse. Society, trying to satisfy the increasing demands of searching for social and economic well-being, has caused an acute unbalance between the demand and the natural resource supply capacity. A critical example of this is the management of water in urban areas, where its availability for the different user sectors is affected by its quality, quantity, space and time variation restrictions, generating strong competition for water’s usage and conflict of interest among the different sectors. Cali, Colombia presents the same situation and has been participating in the SWITCH Project since 2007 (co-financed by the European Union) through Universidad del Valle and under the coordination of UNESCO-IHE, initially as a case study and later, since 2008, Cali became a demo city. SWITCH is focused on the development, application and demonstration of technological and socio-economical solutions and strategies to facilitate the effective and sustainable development of water management in urban areas using “the city of the future”, and planning 30 to 50 years ahead as the model. It involves a variety of topics related to the change of paradigm in urban water management, including urban sewage, water supply, multiple water uses, efficient water use, sanitation, domestic and industrial waste water management, urban water cycle, planning, governance and institutional aspects. The main objective of this report is to present a preliminary proposal of strategies focused towards the change in paradigm in terms of Cali’s wastewater management. Based on the diagnose made by the SWITCH Project framework, in 2007 the strategic proposal was made for three working locations in Cali, considering future planning and growth trends, the sewage drainage areas, and the perspectives of conducting most of the wastewater towards the WwTP-C. These sectors are: 1) drainage area to the WwTP-C, 2) southern Drainage System 3) future expansion zone. . This preliminary proposal of strategies for each sector is a draft of the proposal of sustainable alternatives for water management, which would be analyzed during the development of the Project. As a result of the combination of the different actions present in relation to time, space and the components of the water urban cycle: housing, industry, supply system, wastewater collection and transportation, storm water drainage, wastewater treatment and disposal, and management of solid waste and the water basin.. These actions are framed and supported by the actions implemented in the social environment, considering institutional aspects, economic tools and the political and standardization tools, being within the identification of the decrease of environmental aspects and the improvement of quality standards and economic costs evaluation. This document includes the introduction, a description of Cali in the context of the Upper Cauca River Basin (Chapter 2); the main characteristics and the existing situation of the Cali drainage system (Chapter 3); an analysis of the pollution control evolution in Colombia and the influence area of the city of Cali, with emphasis on standardization and

Chapter 1 Introduction


political aspects and the resulting strategies (Chapter 4). Additionally, a review and experiences of the available elements and technologies for wastewater management required for a change in paradigm (Chapter 5), making a comparison with the current situation of Cali (Chapter 6). Finally, the document includes a revision and analysis of the alternatives and strategies that the institutions have proposed in the different local and regional plans and in the studies and research made in the study zone. It also includes a proposal of strategies aimed at changing wastewater management paradigms in the city of Cali (Chapter 7).

Chapter 2. The city of Cali in the context of the Cauca River basin


2 THE CITY OF CALI IN THE CONTEXT OF THE CAUCA RIVER BASIN 2.1 CAUCA RIVER BASIN The Cauca River is the second most important water source in Colombia and is the main tributary of the Magdalena River basin, with a length of 1350 km and an area of approximately 63300 km2 (Figure 2.1). Born in the Colombian Andean mountain range (Macizo Colombian), it surrounds the Mooreland of Sotará and crosses Colombia from South to North until it meets the Magdalena River. The river crosses the departments of Cauca, Valle del Cauca, Risaralda, Quindío, Caldas, Antioquia, Cordoba, Sucre and Bolivar. The basin has approximately 183 municipalities in these departments, with 10 million inhabitants, who represent approximately 25% of the Colombian population (Galvis et al, 2001).

Figure 2.1 Cauca River Basin General Location Source: Universidad del Valle, 2008



The hydrographic Cauca River basin occupies a privileged location within the national context due to its geographic, topographic, climatic and infrastructure conditions for human settlements, industrial development, agriculture and mining. Along the Cauca River basin are the sugar cane plantations and the Colombian sugar industry, part of the coffee zone, the zones of mining and farming development and an important sector of the manufacturing industry of the country (Velez et al., 2003). The Cauca River basin is divided and classified in three sections: the Upper Cauca (called the geographical Cauca valley), the Middle Cauca and the Low Cauca (Figure 2.2) - These Upper Cauca areas have the highest population density - approximately 3,5 million inhabitants. Compared to the rest of the River (CVC, 2004), this condition has resulted in the use of the resource for the water supply for domestic, agricultural and industrial consumption. Also, it receives wastewater discharges in some cases without treatment, causing high water quality deterioration, limiting the natural functions of this important water source (Holguín et al., 2005).

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Figure 2.2 Cauca River Basin General Classification Source: CVC and Universidad del Valle, 2007a

2.2 UPPER CAUCA RIVER BASIN The departments of Cauca, Valle del Cauca, Risaralda and Quindío are located within the Cauca River Basin, specifically in the Upper Cauca region, or the geographical valley. This has a great significance to the regional economy, being used for activities such as: energy generation, water supply for human consumption, industry, agriculture, recreation, fishing, and extraction of materials (see Figure 2.3). It is also used as a source and receiving body of solid waste discharges of industrial and domestic wastewater which has caused the deterioration of its water quality. Its importance in the region makes the water quality study a priority in order to evaluate and control the anthropic impact, ensure water supply for diverse uses and provide the necessary strengthening of the integrated water resource management in the region (CVC, 2004).



Salvajina Dam Puerto Mallarino drinking water treatment plant

Water extraction for agricultural irrigation Sand extraction from the riverbed Figure 2.3 Multiple Water Uses - Cauca River

Source: EMCALI and Universidad del Valle, 2006

The geographical valley of the Cauca River basin has 39 sub-basins, with a total drainage area of 11,443 Km2. River tributaries in this area can be classified as streams, having a strong slope, which have increased considerably and bring to the Cauca River significant volumes of sediment and material drag, especially during the rainy periods (CVC and Universidad del Valle, 2000). In the Upper Cauca region there is a bimodal rainfall pattern (periods of rain and dry periods), which is characteristic of the Andean region, as a result of the intertropical convergence. In this regime there are two rainy periods (March-May, September-November) and two dry or low rainfall periods (December-February, June- August). The average temperature is 24°C with variations in the range of 10°C to 38°C. The average annual precipitation is about 1000 mm and the average monthly humidity is in the range of 70% to 75%, mainly due to the cloud dissipation coming from the Pacific Ocean that are able to pass the Western mountain range, getting warm and moving towards the Central Mountain Range (CVC, 2002). With regards to the socio-economic aspects in the Cauca Department, the main activities in both the middle and upper basin are: agricultural, industrial (industrial parks and commerce), mining, and livestock. In the Department of Valle del Cauca, the economic activities are basically agricultural, livestock, forestry, mining, and industrial (the industrial Jamundí-Cali-Yumbo corridor is one of the most important in Colombia, having close to 700 industries from the different sectors) (EMCALI and Universidad del Valle, 2006).

Fuente: Proyecto PMC






Environmental problems of water resources in the Cauca River in general, are associated with the presence of degraded areas by the inappropriate use of soil, water pollution by wastewater discharges from urban centres, the contributions of wastewater of different industries and illegal slums, water pollution by mining, the process of widespread deforestation and pollution by leachate from solid waste dumps and open pit and poorly operated landfills (CVC and Universidad del Valle, 2001). The main problems in relation to the integrated water resource management in the Cauca River basin in general occur because even though there are many policies and plans at national, regional and local level, the regulations for the control of pollution of the water resources, set decades ago and of which an effective part is currently in use, have been designed based on a “corrective approach” and more precisely, based on “the end-of-pipe approach", rather than a preventive and integral one. The current regulations are directed to mitigate the impact of waste discharges on the receiving water bodies, mainly through two complementary policies: a first one of control and a second one based on an economic resource known as the payment of fees when discharging into the water bodies. Although in the past years, the development of new policies and programs that aim at the implementation of measures to improve the sustainable development has been noticed, still the “end-of-the-pipe” approach is the most widely used when referring to the integrated management of water resources. In addition, the institutional framework of the water and sanitation sector that regulates in which each institution it has an area and a specific subject of intervention prevents the exchange and flow of information, duplicates efforts and resources, and prevents the development of integrated water management. Additionally, the jurisdiction areas have been conceived based on political and administrative limits rather than based according to the river basins. In some occasions the jurisdiction and responsibility of the institutions is not very clear in terms of managing the environmental problems of the city; hence, water pollution problems continue without solution (Universidad del Valle, 2008). The limitation in the availability of economical resources prevents the implementation of programs and technologies conceived inside the framework of the sustainability principles and integrated management. Plans of action to mitigate and prevent contamination of water bodies are not planned on a long term. Rather, such plans are proposed in a “short term basis” to remediate the so thought “immediate problems”. Cauca River in the Cauca Department from its source to the sector located near the Desbaratado River (in the border with the Valle del Cauca Department) receives an average of 20.86 ton/day of BOD load, being the municipal sector the highest contributor with 68% (14,27 ton/day) of the total BOD load. It additionally receives high industrial wastewater contributions mainly from the paper and sugar cane industries (around 4,44 ton/day) which correspond to 86,4% of the total industrial discharges into the river basin. Thee total load discharge from this sector is 5,15 ton/day. The other contamination load comes from the slaughterhouses, with a 7% of the total contribution (1,43 ton/day) (CRC, 2007). In the Department of Valle del Cauca there is a noticeable deterioration of water quality in the Cauca River, as the municipality of Cali and the other municipalities located along the



river discharge theirs domestic and industrial pollution load. In 2007 in the jurisdiction area of the CVC, approximately 216 ton/day of BOD5 were discharged into the Cauca River basin. The highest contaminating load is caused by municipal discharges for a total of 155,07 ton/day, which represent 71,9 % of the total discharged load, being Cali the main contributor with a contamination load of 79,6 ton/day. The productive sectors discharged 60,43 ton/day, which represents 28,04% of the total 2007 discharges into the Cauca River (For more details, see Section 4.2.2) (CVC, 2007a). The Corporación Autónoma Regional del Valle del Cauca – CVC since the mid 60’s has evaluated the water quality of the Cauca River. In order to comply with such objective, it has divided the river in three sectors, as follows: Section I, which goes from the Salvajina Dam to El Hormiguero, Section II, from Hormiguero to Mediacanoa, and Section III, from Mediacanoa to La Virginia (Figure 2.4) (EMCALI and Universidad del Valle, 2006).

Figure 2.4 Dissolved oxygen profile in the Cauca River - A) Rainy condition B) Dry

condition Source: Universidad del Valle, 2008

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The lower the value is, the higher the contamination found in the water body is presented, showing concentrations registered by the CVC in tests made at the 19 stations on the Cauca River’s geographical valley, in the section between Salvajina and La Virginia. Such monitoring, which were started in 1980, where made during the periods of 1985-1990, 1993 – 1997, 1998 – 2003 under dry and rainy conditions. Figure 2.4 shows the impact generated over the Cauca river due to the discharges of the municipalities of Cali and Yumbo, and the industries, sugar mills and the paper industry, mainly. These show a general behaviour for the two weather conditions, as follows: Section I has the adequate dissolved oxygen parameter levels (5-7 mg/L), while in Section II this level starts decreasing less than 5 mg/L) due to the previously mentioned impacts. Section III shows a slight recovery trend. The most critical condition, where the lowest values are present during the dry season with records of practically 0 mg/L in the Paso de La Torre and Mediacanoa stations. This impairment in the water quality according to these levels limits the destination of the resource for the conservation of water life, according to Decree 1594 of 1984 regarding the dissolved oxygen parameter in this water body. During modelling project of the Cauca River (PMC), a study of the adaptation of a water quality index for the potential use of water bodies as sources for human consumption was carried out by ICAUCA to evaluate the Cauca River. This adaptation was made based on the most widely used national and international standards, according to the environmental conditions present in the Cauca River basin (Figure 2.5).

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Figure 2.5 Water quality in the Cauca River according to ICAUCA index. Period 1993 – 1997 and 1998 – 2002. Rainy, transition and dry condition.

Source: Patiño et al., 2005 ICAUCA index showed that none of the monitored stations along the Cauca River presents an optimum water quality. In the section between Salvajina–Hormiguero (before Cali), the river reports the highest ICAUCA values, classifying the water between good and



acceptable. Once the river passes the city of Cali, water quality becomes inadequate, indicating the impact caused by the city, municipality and industry discharges that seriously affect the quality and later uses of this water body (Patiño et al., 2005). Another element affecting the Cauca River’s water quality is the Salvajina Dam (one of the most important regulation systems of the Cauca River). Since its initial operation, the regulating effect of the dam has introduced changes in the volume regime in Cauca River, added to the changes caused by the progressive deterioration of the main source of development in the Region. In summary, effects on the Cauca River water quality caused by the Salvajina Dam operation (CVC and Universidad del Valle, 2007b) are: a) hourly variation of the Dissolved Oxygen levels due to the photosynthesis activity of algae present in the dam, b) dilution of the polluting load and increase in the DO levels as a result of the increase in water volume released by the dam towards the River. Considering that only when this rapidly occurs the levels of DO decrease due to the increase in the speeds of the flow that produces the dragging of materials on the bed of the river causing the “first flush phenomena”, and c) the capacity of self-recovery of the river decrease, since the concentration of DO in the water coming from Salvajina is lower than the Cauca River’s water concentration. 2.3 MUNICIPALITY OF CALI 2.3.1 General characteristics The city of Cali is the capital of the Valle del Cauca Department. It is located to the south-west part of Colombia between the Central Mountain Range and the Pacific Ocean; it is located near to the Port of Buenaventura which is the main commercial port in the country (DAPM, 2000). Cali is the third city most important of the country, with 560,3 Km2 of a municipal area. Figure 2.6 show the location

Colombia

Suramérica Valle del Cauca

Cali

Figure 2.6. Geographic location City of Cali

Source: Universidad del Valle, 2008



Cali covers an area of 56,025 hectares, of which 43,899 are rural areas and 12,125 in urban areas which are located between 4,200 and 955 above sea level (m). The rural sector of Cali is formed by 15 villages, out of which 13 are located in the foothills and two in the flat land. These villages are: La Buitrera, El Saladito, La Elvira, Pance, La Paz, La Castilla, Villacarmelo, Montebello, Navarro, Los Andes, Golondrinas, El Hormiguero, Pichindé, Felidia and La Leonera (see Figure 2.7).

Cali Valle Río Cali

Fuente: http//www.cali.gov.co/mapas/index.html

Zona urbana Zona rural

Figure 2.7 Map of the Municipality of Cali.


In general terms, it can be said that the most populated of the 15 villages in the rural zone are: La Buitrera, Montebello and El Hormiguero and the most densely populated are Montebello, La Buitrera and Golondrinas. The urban part of the municipality of Cali is composed by two areas; a) consolidated area which is the existing urban area until year 2007 and consists of 22 “comunas” or districts, and 2) the future development area that is located to the south-east of the city and consists of two areas: Navarro and Cali-Jamundí sectors (see Figure 2.8).



Figure 2.8 Location of existing and future urban areas in the Municipality of Cali

Table 2.1 summarizes some of the Cali characteristics with respect to population, health, education, economy and public services, some of which are shown in detail in the following sections of the document.

Table 2.1 Facts and figures of Cali Aspect Value Source

Growth rate 1,37% DANE, 2005a

Life spam 71,9 years Secretaria de Salud Pública de Santiago de Cali, 2008

Coverage in education 87% Espinosa, 2007 Health coverage 75,3% DAPM, 2006 Non fulfill Basic Needs Index - NBI* 10,9% DANE, 2005a Un-employment rate (year 2007) 12,5% Diario El Pais, 2007 Economic sectors: Industrial Commerce Services

9,44%

60,40% 30,16%

Proexport Cali and Cámara de Comercio de Cali, 2005

Coverage of water public services: Drinking water Sewage Wastewater treatment

97%

94,8% 56%

EMCALI, 2007

* The indicators that evaluate the coverage of the non-fulfill basic needs index are: inadequate dwellings, overpopulated dwellings, dwellings with inadequate public services, dwellings with high economical dependency, and dwellings with school-age children which do not attend school.

2.3.2 Demography According to the National Statistics Department - DANE (2005a), the municipality of Cali has a total estimated population of 2075380 inhabitants, from which 979530 are male and



1095850 are female. According to these data, Cali is the third largest city in Colombia in terms of population, after Bogotá and Medellin. Furthermore, according to DAPM (2006), in year 2005, 85% of Cali citizens were located in estratos 1, 2 and 3. Estratos is a way of economically classifying the sectors in the city; Hence estratos 1 and 2 correspond to the most economical stressed groups and estratos 3, 4, 5 and 6 correspond to the economical middle class to the upper class economic groups. 2.3.3 Physical Aspects Figure 2.9 shows a geographical cut, which leads to environmental units differentiated in terms of climate, soil and landscape, which can be divided into three parts: The upper part corresponds to the National Park of the Farallones de Cali and the Forest Protected Area. The intermediate area includes the municipal rural area, where there is a mixture of agricultural uses, with the purpose of being rural households and settlements. Finally, the flat land, where large plots of land are used for agricultural purposes and most of the urban area of the municipality. (DAPM, 2002).

Figure 2.9 Cross section of the Municipality of Cali

Source: DAPM, 2002

The municipality has a range of elevations above sea level between 956 m and 4200 m, thus offers a wide range of temperatures between 10 y 24°C as monthly mean temperatures between Los Farallones and the geographical valley respectively.

The regime of precipitation distribution presents a very defined with two wet periods that correspond to the months March-April-May and October-November-December and two dry periods for the months of January to February and June-July-August-September. The precipitation of the city varies between 1300 mm/year in the south and 1000 mm/year in the north, increasing in the southwest. In the mountainous rainfall varies between 1300 and 3000 mm/year.



The average monthly relative humidity, introduced throughout the year with a distribution values higher in the months of May and November and lower in the months of January- February and July-August. The extreme of humidity is between 45 and 98% and an annual average of 65% at the Station San Luis North and 73% in station Univalle South. In the municipality of Cali there are four climates, based on air temperature and the spatial distribution of precipitation, which are: Hot and moderated dry weather, Middle humid weather, Cold and moderated humid weather, Humid cold weather. 2.3.4 Socioeconomic Aspects Cali has a strategic geographic location which has contributed to the economic development of the city and has turned it into the region’s core in different aspects. As the administrative and service centre it has an action radius that covers the departments of Valle del Cauca, Southern Choco, Cauca, and Nariño. According to the economic census held in Cali in 2005, there are 51641 economic units (DANE, 2005b), out of which 60.4% correspond to the commercial sector, 30.1% to the services sector and 9.5% to the industry (Proexport et al., 2005). Despite to the fact that the commercial sector represents the main economic activity in the municipality with 60.4%, moreover, this economic sector represent around 36.4% of the employment rate. According to the economic census, the delivery of services is the main source of employment with 47.0% of the employment rate. 2.3.5 Public services EMCALI is the company responsible for the delivery of water supply, sewage and energy services in the municipality of Cali. Water supply system: The current drinking water coverage in Cali is 97% according to the technical planning department of EMCALI (2007). The drinking water distribution system in the city is supplied by five drinking water plants, (see Table 2.2) Puerto Mallarino plant which uses Cauca River as its water source treats and supplies around 76% of the drinking water demand in the city, this source has been suffering a continue water deterioration mainly due to deforestation, to presence of slums located in the protection area and to the discharge of wastewater. The two most important sources of contamination upstream the water intake of Puerto Mallarino Plant are the South Channel and the Navarro disposal site which discharge wastewater and pollution around 5 km upstream the Puerto Mallarino water intake (Universidad del Valle, 2008).



Table 2.2 Installed capacity and production of drinking water in Cali

Source Average Daily

Flow (m3/s)

Plant Installed capacity (m3/s)

Production of drinking water (m3/s)

Puerto Mallarino 6,60 4,11 Cauca River 264 Cauca River 2,50 1,77 Cali River 4,76 Cali River 1,80 1,23 Meléndez River 1,23 La Reforma 1,00 0,41 Pance River - La Ribera 0,03 0,01

Total 11,93 7,53 Source: EMCALI Production information, December 2006. Sewage: The coverage of the sewage system to September 2007 is 94,8%. Following the land topography, the sewage system in Cali is divided in three drainage systems: the South Drainage System (SDS), North-West Drainage system (NDS) and East Drainage System (EDS), through these three drainage systems, Cali directly drains its wastewaters and storm waters to Cauca River. The only way of control of wastewater contamination in the city of Cali is made through the use of the wastewater treatment plant of Cañaveralejo (WwTP-C) which receives around 56% of the total wastewater produced in the city. Solid waste collection and disposal: The company responsible for the collection, transport and disposal of the solid waste produced in the municipality of Cali is EMSIRVA. The approximate 1800 ton/day of waste produced in the city and even before June 26 (2008) (RGS, 2008) were collected and taken to the disposal site of Navarro, currently EMSIRVA, after carrying out a tendering process, awarded in December 2007 to the promise of Sociedad Futura Interaseo del Valle S.A E.S.P. the service of waste disposal of Cali by landfill, which will be located in the municipality of Yotoco, which is 42 km away from the city of Cali. The closure of the current transitional filling Navarro started in April 2008 (SSPD, 2008). The inadequate disposal of solid waste all around the city in channels, drains and structures of the sewage system cause problems of floods, presence of vectors in the city and bad sanitation and hygiene environment. The main environment impact caused by the disposal site of Navarro is the leachate contamination in surface and underground waters, additionally is also reflected in the presence of hazardous substances such as metals among others. Furthermore, regarding surface water around Navarro site which is mainly composed by Cauca River, “Madrevieja” and South Channel, such systems are in imminent danger of contamination through percolation of leachate or clandestine direct discharge to them (DAPM and Ingesan Ltda, 2005). Energy: EMCALI is the responsible for providing the electric energy service to the municipalities of Cali and Yumbo. The company is the owner of the distribution infrastructure and together with EPSA (Energy Company of the Pacific) own the energy sub-stations which are connected to the electric energy national network. Telecommunications: EMCALI is the principal enterprise of the service of telephony with 85 % of the local market. At (2007) EMCALI has approximately 510000 users. Other companies on the market of public telephony are UNITEL, Telecom, and ERT.



Additionally there are three mobile operators with a national coverage and technology GSM. 2.3.6 Hydrographic Aspects The city of Cali has seven rivers that form the landscape and hydrologic potential of the municipality, among these is the Cauca River (along the right side of the city) and Pance River, Meléndez, Lili, Cañaveralejo, Cali, which Aguacatal through the city and finally discharged to the Cauca River. The network of drainage of the seven rivers has an overall of 757,56 km (DAPM, 2000). The hydrographic network of the municipality extends predominantly in direction West-East, with the exception of the Cauca River that has a direction South-North. Around 92% of the river basin’ areas is located at 1200 m above sea level in the highest part of the municipality. This network offers the possibility of using its water for several uses by gravity or pumping operations. Rivers born in the municipality head may be used by gravity for the city’s water supply. As a matter of fact, the Cauca River was the city’s main water source during the first 400 years. Currently (year 2009) the Cauca River supplies about 76% of the population of Cali, through the production of the drinking water plants of Puerto Mallarino and the Cauca River (Universidad del Valle, 2008). The urban rivers are used with different purposes: water supply for human consumption, hydroelectric generation, industry, agriculture, recreation, extraction of materials, landscaping, irrigation for aesthetic purposes, clothes washing (Aguacatal River) and is also used as a source and receiving of solid waste dumping of industrial and domestic wastewater which has caused the deterioration of water quality. These rivers haven been affected in their composition and characteristics along its way through the urban area of Cali, due to the accelerated population growth, both in vegetative and migrational status and the neighbouring rural areas, and settlements in the river banks which generates untreated wastewater discharges, impeding its recreative use and increasing the purification costs of the waters due to the domestic use, as it occurs with the rivers crossing the municipality, such as the Aguacatal, Meléndez, Cañaveralejo, Cali, Lili, Pance and Cauca Rivers. Due to the improper use of the river basins in the municipality, the deterioration of the reserve zone (30 meters on each river bank), the problems created by sub-urban settlements, the lack of management and awareness of the settlers located in the upper area and the inadequate planning of the soil use in the area, there is no regulation of water flow, producing a high flow variation, causing scarcity during the dry season and high rainfall levels during the rainy season. The ground water constitutes an important resource that contributes considerably to supply the seasonal and spatial water deficit in the Valle del Cauca Department and specifically in Cali, becoming an alternative source of water supply for the municipality. The quality of the underground water in the municipality of Cali is classified in general terms as good, being best in the sector of Pance (in the physical - chemical aspect). In the microbiological aspect there is located pollution in the sub river basin of Pance and Cauca River, as result of the septic tanks’ infiltration by lack of sewage systems (DAGMA and ASOCARS, 2005).



The municipality has the Pance, Cali and Cauca aquifers having A units (with an average depth of 120 meters) and C units (with depths between 180-500 m), being the latter a confined aquifer. The reloading zones for the aquifers are associated to the outlets of the Cali, Cañaveralejo, Meléndez and Pance Rivers. The estimated capacity of the aquifers is 168000000 (m3), equivalent to 5330 L/s. At August 2007 DAGMA has identified 475 underground wells in the city of Cali out of which 44 are used by the industry, 235 are used for car washing by the gas stations, 59 are used for irrigation, and 9 are used for human consumption, among other uses. The municipality wetlands are located in the rural and urban zones. Many of the wetlands are located in private terrains with high deterioration levels. The urban area of the municipality of Cali has the following wetlands: El Pondaje, Charco Azul, Panamericano, Los Cisnes, and Las Garzas. The rural area wetlands are: Mojica, Las Vegas, old riverbeds of the Lili, Cascajal and Meléndez Rivers, Pacheco, Ibis, Caño del Estero, Madrevieja Cauca Seco, Marañón, Pascual and La Pailita. In general, the wetlands environmental problems are similar and originated by the impact caused by human beings. This is represented by sub-normal settlements, inadequate wastewater and solid waste management, among others.

Chapter 3. The sewage system of the city of Cali


3 THE SEWAGE SYSTEM OF THE CITY OF CALI

3.1 HISTORICAL EVOLUTION OF THE SEWAGE SYSTEM 3.1.1 Sewage at the beginning of the 20th century Until the end of the XIX century the sewage system was partially open or closed channels that were made in the middle of the roads and streets. In 1910, the municipality of Cali was a small town with less than 20000 inhabitants and did not have the necessary infrastructure to provide the basic public services. Water was provided through public fountains connected to a rudimentary aqueduct and the open channels in the middle of the streets were used as sewage systems. In 1912, the Municipal Council hires the Compañía del Ferrocarril del Pacífico to make the studies for the construction of the water supply and sewage systems. Through these works, the municipality had a sewage network that collected waste and storm waters in a combined system. Due to the consequences of World War I, between 1931 and 1944, the city suffered the worse service provision crisis and the private companies became property of the government. Empresas Municipales de Cali (EMCALI) emerged from this crisis in 1931 (EMCALI, 2007a). In the period between 1950 and 1962 several floodings took place. Back then, Cali’s “sewage system was formed by several independent networks that collected waste and rainfall water to discharge them in the natural basins located closer to the city”, being the drainages insufficient and sometimes non-existent (Vásquez et al, 1995 as cited in Jiménez, 2005). This was a result of the unplanned city growth and the lack of modern urban equipment in the sewage infrastructure, plus the deficient existing sewage system. 3.1.2 First sewer system master plans In 1955, the Municipality of Cali in charge of managing the sewage system hired the consulting firm R.J. Tipton & Associates for the execution of the first Sewage Master Plan. This study proposed a separate sewage system with sanitary interceptors and at the same time proposed three sites for future wastewater treatments: Cañaveralejo wastewater treatment plant WWTP-C, Río Cali WWTP and the Southern-WWTP Between 1945 and 1960, sewage management was transferred to EMCALI (Agreement 36 November 7, 1961), at the same time that EMCALI became an autonomous entity (Agreement 50, December 10, 1961). The South Canal was built in 1960, designed to transport a 70 m3/s flow in order to recover 5,000 ha of floodable terrains by the Lilí, Cascajal, Meléndez and Cañaveralejo rivers. Once the work was finished in 1961 and as a result of the housing needs, these terrains were illegally occupied, causing the expected increase in service demands. The construction of the Eastern interceptor was proposed in 1964: in both first and second sectors, Cañaveralejo collector, Central collector and left margin of the Cali River interceptor. These proposals were executed between 1964 and 1971 (EMCALI, 2007a).



At the beginning of the 70’s, due to the accelerated population growth, settlements without the basic public service infrastructures were created (i.e., Aguablanca district). In order to respond to this social problem, EMCALI designed the “Expansion and improvement of the drinking water and sewage systems of Cali” Program. Celebrating the VI Panamerican Games in Cali in 1971 improved the city’s public services. EMCALI managed an international credit before international organisms in order to carry out the second water supply and sewage master plan for the year 2000. The first stage of the Master Plan, built between 1973 and 1976, was hired with the firm “Buck, Seifert & Jost”. Three hundred forty two thousand meters of sanitary and combined sewage systems were built. This company confirmed the conclusions made by the Tipton Company (1955) and recommended the construction of: separation structures for the existing combined collectors and sanitary interceptors of the expansion zones with separate sewage systems. It also guided the sanitary collectors planning towards the sites for the future construction of the wastewater treatment plants. Hydraulic and hydrologic studies and complementary designs in order to solve drainage problems in the Aguablanca caused by the change in soil use from agricultural to urban were made in additionally, to eliminate the wastewater discharges into the Oriental and South channels, the Cauca collector and the pumping station of Navarro were designed. Between 1978 and 1985 the second phase of the Master Plan was executed, mainly including the execution of works such as: :the Cauca collector, Ciudad Jardín collector, pumping station of Navarro and the first stage of the impulsion pipe into the Cauca River DAPM (2002). Network replacement works in the central and south-eastern part of the city were made in 1979, including the following works Nueva Granada, Ferrocarril Cañaveralejo, Carrera 20, Saavedra Galindo, and San Fernando channels; Cañaverales, Oriental I and II collectors; General collector and the wastewater pumping station. 3.1.3 Wastewater treatment Based on the Cali wastewater treatment pre-feasibility and feasibility studies, EMCALI, in 1980 proposed the liquid discharges decontamination plan, complementing the sewage system with three wastewater treatment plants (Recommendation by R. J. Tipton and Associates, 1955). 85% in the WwTP-C, 15% Rio Cali – WwTP (North-eastern sector) and the Southern WwTP (future expansion area) (Llanos, 2000). In 1985, EMCALI and the INGESAM/URS Consortium made a feasibility study of the Cali wastewater treatment project (EMCALI and INGESAM/URS, 1985) in which two future alternatives were presented, called treatment politics 1 and 2. Politic 1 considered a minimum DO concentration of 0.5 mg/l, which was the concentration obtained through a primary treatment in 2000 (35% BOD removal) and a secondary treatment after 2023. Treatment requirements were based on the possibility of installing two aerobic contaminant removal plants: a) WwTP Cañaveralejo (Collects from the right Cali River margin) and b) WwTP Acopi (Collects from the left Cali River margin and Puerto Isaacs, except for the papel industry).



Between 1985 and 1987 the Southern CVC Canal was expanded, contributing in flooding control. .In 1986 the NITOGOI Consortium and EMCALI started the WwTP-C designs. Also in that year EMCALI made a loan from the Japanese Government for 445 million yens, but due to lack of guarantee of the nation, this loan did not become effective. Therefore, the Japanese Government conditioned the credit through the Overseas Economic Cooperation Fund (OECF) for 154 million dollars (the initial WwTP cost was 74 million dollars, but this amount in 2000 is 154 million dollars, or 110% more expensive). Consulting, auditing and design works were assigned to a Japanese consortium for a period of 4-5 years that became a 14 year period that generated EMCALI a surcharge of approximately 3700 million pesos. In 1990, Japanese engineers and EMCALI, made the review of the preliminary designs and investment costs of the WwTP-C with the company Hanzen and Sawyer from the USA. In 1992, NITOGOI and Hanzen and Sawyer, changed the structural design of the plant. EMCALI in 1994 identified the reform works for the combined sewage system separation structures of the Southern Canal and Eastern Canal, as well as the separation structures maintenance program which allows controlling wastewater flow in the channels. In 1995, EMCALI, due to the delays in the design of the WwTP-C ended the NITOGOI consulting contract by mutual consent. During the same year, Cali’s Municipal Council authorized the use of soils for the construction of the Cañaveralejo wastewater treatment plant WwTP-C. The bidding process for the construction of the WwTP-C started in 1996. The WwTP construction contract was subscribed in 1997 with a Consortium formed by the following companies: Constructora Norberto Odebrecht S.A., Mitsubishi Corporation, Degremont Colombia S.A., Degremont Argentina S.A., and Constructora Conciviles S.A., for an amount of $US 83098245. The objective of this contract was the execution of civil works and the supply, transportation, assembly, installation, equipment tests, start up and operation of the plant. The treatment level was a primary treatment. By the end of 2001, the WwTP-C starts operating with maintenance and operation costs of approximately $9696 million pesos per year at present value. The real cost depends of the greater or lesser consumption of chemicals required to reach the expected efficiencies. These costs are included in the tariff (EMCALI, 2007b). In order to comply with Resolution 1433 of 2004 issued by the MAVDT, EMCALI in 2007 proposed a Sanitation and Discharge Management Plan – PSMV with a projection for year 2016, which focus actions in decreasing contamination levels through wastewater control in storm water Canals and the complementary sanitary sewage works, concentrating wastewater in the WwTP-C. 3.2 SEWAGE SYSTEM INFRAESTRUCTURE The sewage system in Cali (EMCALI, 2007b) is composed of 1) sanitary and combined water sewers, 2) stormwater sewers, 2) regulation systems, 3) pumping stations and 4) Cañaveralejo wastewater treatment plant – WwTP-C.



3.2.1 Components Sanitary and combined sewers: This network is formed by 2832 km, out of which 2099 km are combined network and 733 km are sanitary network. The sewage is composed of matrix networks and domiciliary connections. Cali’s sewage system is a complex system since issues such as illegal connections and wastewater discharges to storm water channels have caused throughout the years that the majority of the sewage system has become mostly combined. According to EMCALI, the coverage of the sewage system to September 2007 is 94,8%. Storm sewers: This network has a canal length of 8872 km (87% are coated); 100000 drains and 20 sand remover units. The rivers making part of the drainage system are: Lili, Meléndez, Cañaveralejo, Cali, Aguacatal and Cauca Rivers. Regulation systems: a) It consists of an artificial wetland constructed in the 60`s for the regulation of the storm water in the city and for the regulation of the frequent flood events presented in this area of the city. It is composed by two lagoons, one denominated the Pondaje (south) and the other Charco azul (north), the ponds finally discharge to the Oriental Medio Channel. Due to presence of illegal slums in the area, the lagoons have lost their initial hydraulic capacity (EMCALI, 2007b) and b) the Cañaveralejo dam is an artificial system of regulation whose aim is to buffer the flow peaks that appear during winter season in the Cañaveralejo River and hence avoid flood events in nearby zones. It covers an area of 78492 m2. Pumping stations: The pumping stations are classified according to the characteristics of the water pumped in: rain, residual and / or mixed (storm water and wastewater) (see Table 3.1).

Table 3.1. Pumping stations in the city of Cali Pumping station Type Installed capacity (m3/s)

Navarro Residual 8,00 Cañaveralejo Residual 6,00 Aguablanca Residual 2,80

Calipso Mixed 4,20 Floralia Mixed 11,00

Paso del Comercio Storm 33,2 Guaduales Storm 8,00

Puerto Mallarino Storm 18,0 Source: EMCALI, 2007b

3.2.2 Drainage systems Following the land topography, the sewage system in Cali is divided in three drainage systems: the South Drainage System (SDS), North-West Drainage System (NDS) and East Drainage System (EDS). Figure 3.1 shows the areas of drainage of each one of these systems. At the same time, these systems include the collector, interceptor and channels infrastructure (EMCALI and Universidad del Valle, 2006).



Cali River mouth

South Channel

Puerto Mallarino P. S.

Paso del Comercio P. S.

Cañaveralejo P. S.

Floralia P. S.

Agua Blanca P. S.

Cau

ca R

iver

Pance River

Lili River

Melendez River

Cañaveralejo River

Aguacatal RiverCh

ocho

Rive

r

margen

derec

ha co

llecto

r

El Pon

daje

Lagoo

n (South

)

Charco

Azu

l Lag

oon (N

orth)

Interceptor orientalFirst Sector

margen

izquier

da colle

ctor

Nueva Granada channel

Cañaveralejo WWTP

Brisas de los Alamos channel

Menga channelCalle 51 channel

Santa MonicaChannel

Vipasa channel

Inge

nio

I cha

nnel

Inge

nio

II ch

anne

l

Napoles channel

Paso

anch

o1

chan

nel

Cll 1

4 ch

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l

Com

fand

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Calle 4

8 chan

nel

Navarro P. S.

Secu

ndar

io ch

anne

l

Inte

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rient

al

Seco

ndly

Sect

or

General

Collector

Av.

Los

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Res

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ch

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l

E. 1

05.0

00

N. 95.000

N. 100.000

N. 105.000

N. 110.000

N. 115.000

E. 1

20.0

00

E. 1

10.0

00

Orie

ntal

chan

nel

TRAS

VA

SE

E. 1

15.0

00

Cañaveralejo channel

Collectors and Interceptors

North-west Drainage System

East Drainage System

Expansion area Cali-Jamundi

NOTE:

Channels

Pumping stations

South Drainage System

Special expansion area Navarro

Panc

eco

lleto

r

Cal

i Riv

er

Cauca colle

ctor

Sludge DWTP discharge

E. 1

15.0

00

Puerto mallarino DWTP

Cali River mouth

South Channel



Cañaveralejo P. S.

Floralia P. S.

Agua Blanca P. S.

Cau

ca R

iver

Pance River

Lili River

Melendez River

Cañaveralejo River

Aguacatal RiverCh

ocho

Rive

r

margen

derec

ha co

llecto

r

El Pon

daje

Lagoo

n (South

)

Charco

Azu

l Lag

oon (N

orth)

Interceptor orientalFirst Sector

margen

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da colle

ctor


Cañaveralejo WWTP



Santa MonicaChannel

Vipasa channel

Inge

nio

I cha

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Inge

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II ch

anne

l

Napoles channel

Paso

anch

o1

chan

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Cll 1

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Calle 4

8 chan

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Navarro P. S.

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Seco

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Sect

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General

Collector

Av.

Los

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ch

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E. 1

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00

N. 95.000

N. 100.000

N. 105.000

N. 110.000

N. 115.000

E. 1

20.0

00

E. 1

10.0

00

Orie

ntal

chan

nel

TRAS

VA

SE

E. 1

15.0

00






NOTE:

Channels

Pumping stations







NOTE:

Channels

Pumping stations



Panc

eco

lleto

r

Cal

i Riv

er

Cauca colle

ctor


E. 1

15.0

00


Figure 3.1. Drainage systems in the city of Cali. Source: Adapted of EMCALI and Universidad del Valle, 2006



Through these three drainage systems, Cali directly drains its wastewaters and storm waters through the left margin of the Cauca River using six discharge points authorized by the Department of Environmental Management (DAGMA): 1) South Channel, 2) pumping station Puerto Mallarino, 3) pumping station Paso del Comercio, 4) pumping station Floralia, 5) Margen Izquierdo collector (Cali River) and 6) effluent from Wastewater Treatment Plant Cañaveralejo (WwTP-C). South drainage system This system is formed by the sanitary and rainfall sewage and the Cañaveralejo, Meléndez and Lilí Rivers. It has 96.64% sewage network coverage, being 2500 km. long. It also has 78000 drains, 250 separation structures and approximately 89000 m of canals. The sanitary and/or combined sewage is formed by the Pance and Ciudad Jardín collectors. The construction of a Cañaveralejo collector and the Pance auxilliary collector are programmed. (EMCALI, 2007b). The pluvial system is formed by Canals, streams and rivers in three large sub-systems 1) Cañaveralejo River sub-system, 2) Ferrocarril channel subsytem and 3) Meléndez and Lili Rivers and the Southern Channel (Figure 3.2)


Cañaveralejo River Subsystem

Ferrocarril ChannelSubsystem

Melendez and LiliRivers

Subsystems

Channels Brook Channels Channels Rivers

1. Los Cristales2. Av. Los Cerrros3. San Fernando4. Puente Palma5. Autopista 36. Pasoancho 17. Calle 148. Cañaveralejo riverchannel9. Los Jinetes

1. Contingente2. El Indio3. Guarrus4. Calle 12 Cra 545. Cañaveralejo River

1. Nueva Granada2. Canal Autopista 23. Canal Olimpico4. Canal Pasoancho 25. Canal Santa Helena6. Canal Ferrocarril

1. Napoles2. Ingenio 13. Ingenio 24. Ingenio 35. Comfandi6. Sur7. Caney

1. Melendez2. Lili

CAUCA RIVER


Cañaveralejo River Subsystem

Ferrocarril ChannelSubsystem

Melendez and LiliRivers

Subsystems

Channels Brook Channels Channels Rivers

1. Los Cristales2. Av. Los Cerrros3. San Fernando4. Puente Palma5. Autopista 36. Pasoancho 17. Calle 148. Cañaveralejo riverchannel9. Los Jinetes

1. Contingente2. El Indio3. Guarrus4. Calle 12 Cra 545. Cañaveralejo River

1. Nueva Granada2. Canal Autopista 23. Canal Olimpico4. Canal Pasoancho 25. Canal Santa Helena6. Canal Ferrocarril

1. Napoles2. Ingenio 13. Ingenio 24. Ingenio 35. Comfandi6. Sur7. Caney

1. Melendez2. Lili

CAUCA RIVER Figure 3.2. Formation of the South Drainage Pluvial System

Source: MANOV and Análisis Ambiental, 2007

This system drains by gravity the south-western part of the city through the main channels which is called the Southern Channel, or 25% of the total wastewater of the city discharged into the Cauca River. The South Drainage System is the only system that does not count with pumping stations, it completely works by gravity. It has the Cañaveralejo reservoir, a



regulatory system, which has lost part of its capacity to retain rainfall peaks due to solid deposits caused by the Cañaveralejo River Basin deterioration. The final wastewater discharge (see Figure 3.3) of this system is the Cauca River, this point is located approx. 5 km upstream the water intake point of the drinking plants of Puerto Mallarino and Cauca River, causing: 1) an increase in the risk of use of the source for the water supply of the city, 2) a greater demand in the operational capacity of the drinking treatment systems and 3) an increase in the purification costs.

Figure 3.3. South Channel discharge point to Cauca River


North-West Drainage System The system is composed of sewage, storm water, Cali and Aguacatal Rivers, also has two pumping stations, there are no regulations systems. The system is composed mainly by the sanitary and storm water collectors Left Margin, Right Margin and Menga. The main collector is the Margen Izquierdo collector which is located parallel to Cali River, its total length is 12 km. During its course, it receives wastewater from the north-east part of the city and from Margen Derecho collector. Finally, Margen Izquierdo collector discharges (Figure 3.4) to Cali River approximately 800 m before Cali River discharges to Cauca River. The Margen Izquierdo collector conveys and transport wastewater directly to Cauca River, around 10% of the total wastewater produced by the city of Cali.

Figure 3.4. Margen Izquierdo collector discharge point




Since December (2007) are operating the works of construction made for convey and transport the wastewater from the Marginals collectors up to the wastewater treatment plant of Cañaveralejo (WwTP-C), with the main purpose of reduce the polluting discharges made directly to the Cauca River from Floralia pumping station and take advantage of the capacity of the plant and increasing the flow to treat in approximately 850 L/s (EMCALI, 2007b). Rainfall sewage is made by open canals of approximately 13979 km. The pumping stations of this system are: a) Guaduales, it is located in the right margin of the Cali River, it is a storm water station and counts with and installed capacity of 8 m3/s, which through a network of channels discharge first to Cali River and pumping station Floralia and finally to Cauca River (which pumps around 2% of the total wastewater produced in the city to Cauca River). Eastern Drainage System The East Drainage System has sanitary sewage and two regulating lagoons. This area has the greatest amount of pumping stations, collectors and interceptors. The main components of this system are: Central, Cauca and General collectors, Oriental and Cañaveralejo interceptors, Cañaveralejo, Navarro and Aguablanca pumping stations and the Wastewater Treatment Plant of Cañaveralejo (WwTP-C). The Central collector is the principal of the system; it works by gravity and receives the wastewater coming from Oriental interceptor, other secondary interceptors and Cañaveralejo interceptor through Cañaveralejo pumping station. This collector is the largest city wastewater discharge into the Cauca River (Figure 3.5). It is formed by the discharges of the Paso del Comercio Pumping Station (169 L/s), Puerto Mallarino (322 L/s) and the WwTP effluent (3810 L/s), which contribute a total of approximately 4,301 L/s (EMCALI, 2007b). The Central Collector, after receiving the Cañaveralejo Pumping Station discharge is called the General Collector, which is connected to the line influent of the WwTP-C and counts with a by-pass system to the Cauca River, which is used in rainy conditions. The water flow entering the plant was 1,21 m3/s (minimum), 3,79 m3/s (average) and 6,36 m3/s (maximum) (EMCALI, 2007c).

Figure 3.5. Central collector discharge point Source: EMCALI and Universidad del Valle, 2006



The stormwater system has a total canal length of 38310 km. The main system canal is the Eastern Canal, with a length of 11811 km and a transportation capability of 25 m3/s. This canal is divided in three sections: Upper, Middle and Lower Sections and also includes the Cauquita North and secondary Canals. It also has rainfall water pumping stations (with wastewater presence), which drain the East canal when the Cauca River has high levels (950 m) in order to avoid flooding caused by damming. . Wastewater pumping stations are: Aguablanca, Navarro and Cañaveralejo. The stormwater and/or wastewater pumping stations are: Paso del Comercio, Puerto Mallarino and Calipso. Regulation systems it consists of an artificial wetland, it is composed by two lagoons; one denominated the Pondaje (south) and the other Charco Azul (north). The ponds finally discharge to the Eastern Middle Channel. Due to presence of illegal slums in the area, the lagoons have lost their initial hydraulic capacity (Table 3.2).

Table 3.2. Comparison between design and characteristics - Pondaje Lagoons Characteristics Design (1959) Year

Area (ha) 31 25 (80% of the original area)* Storage capacity (m3) 620000 100000 (only 16% of the original storage capacity is left)** Inhabitants living near the lagoons

250 (year 1969)

61000 (commune 13) and 4889 people living in the lagoon protected area *

Source: Quantum, 2000* (RGS, 2008a)**. These regulation lagoons were designed to serve as dams lowering hygrograms peaks so that the maximum pumping flows could be decreased and a reduction in the costs of operation of the pumping stations could be reached as well. Nevertheless, according to Quantum (2000), the function of the lagoons in was minimal due to: Presence of wastewater in the storm water channels that discharge to the lagoons

(wastewater flow measured in year 2000 was 320 l/s). Direct waste water disposal from illegal slums located around both lagoons Disposition of garbage and solid waste in the channels that discharge to the lagoons and

inside the lagoons as well, (volume of debris found was 203024 m3). Presence of sediments and vegetation inside the lagoons (volume of measured

sediments was 152000 m3 and vegetation 133462 m3) in year 2000. Dissolved oxygen in the lagoon was cero and there was no presence of aquatic life.

In addition, Quantum (2000) found that the areas of the lagoons that were not being occupied by illegal slums (inside and outside) were used as sport fields, due to the high amount of sediments and vegetations present in the lagoons (Figure 3.6). Since 2006, a proposal for the Integrated Recovery of the Pondaje and Charco Azul Lagoons has been led by the Empresa Municipal de Renovación Urbana – EMRU EICE (created in 2002) (DAGMA, 2006)., which was included in the Municipal Development Plan (2008-2011) (Alcaldía de Santiago de Cali, 2008). The goal of the proposal is to improve the hydraulic capacity of the wetlands and to build a sports complex in the neighborhood. Among the main works are the deviation of the wastewater from the



Cañaveralejo Canal (in the South), allowing them to arrive directly into the WwTP (Diario El País, 2008b).

Pondaje Lagoons in 1982.

Source : Quantum (2000). Lagoons El Pondaje and Charco Azul in 2004

Source: Contraloría de Cali, (2005). Figure 3.6. Regulation Systems

The three previously mentioned drainage systems have similar environmental problems: 1) presence of wastewater in the storm water channels, 2) the inadequate disposal of solid waste that cause clogging of channels, 3) presence of sediments in channels, 4) poor conditions of structures of the drainage systems such as Combined Sewer Overflows (CSOs), 5) presence of slums and 6) the presence of hazardous substances specially in the South Drainage System, coming mainly from the industrial discharges and leachate from Navarro disposal site. The drainage system in the most critical conditions is the South Drainage System (CINARA and Universidad del Valle, 2008). 3.2.3 Industrial wastewater discharges The wastewater production in the city of Cali’s current situation, based on year 2007, shows a BOD (Figure 3.7) discharge load from the city to Cauca River estimated around 37% from the total discharge load in the Valle del Cauca Department, and 35% from others municipalities (CVC, 2007a).

Total load discharged 215,49 ton/day

Cali 79,5537%

Sugar cane5,232%Coffee

36,6017%

Others Municipalities

75,5235%

Other Industries

14,117%

Paper4,492%

Figure 3.7. BOD load discharges to Cauca River basin in the Valle del Cauca Department.

Year 2007. Section Salvajina-La Virginia Source: CVC, 2007a



The industries in the urban area of Cali discharge directly their wastewater in the sewage system of the city, according to information reported by DAGMA in 1998-1999 regarding non domestic sector discharges to the sewage system in the city (commercial and industrial sectors), the total BOD and TSS load discharged was approximately 24% and 26% from the total wastewater load generated in the city respectively. However, this is the only existing reference since after 1999 there has not been complete and reliable information regarding the number of commercial and industrial establishments and their average discharges (DAGMA, 2007). The main impact to the domestic wastewater is the contribution of hazardous substances present in the wastes from the industries such as the metal, dental, and mechanic industry. From the reports given by EMCALI in year 2006, the most representative sectors (Table 3.3) wastewater discharge loads (BOD and TSS) were: 1) food and drinks products, 2) services, 3) pulp and paper, 4) healthcare centres and 5) fibres and textiles.

Table 3.3. BOD an TSS load produced by some economical sectors Industrial sector Number of

facilities BOD Load

(kg/day) BOD (%)

TSS load (kg/day)

TSS (%)

Drink and food 26 3334,2 52,3 1310,6 41,3 Services 27 1013,2 15,9 552,0 17,4 Pulp and paper 5 770,0 12,1 318,5 10,0 Healthcare centre 26 751,6 11,8 438,4 13,8 Pharmaceutics and chemistry 16 295,1 4,6 86,2 2,7 Fibres and textiles 9 138,7 2,2 406,5 12,8 Graphic industry 18 34,7 0,5 26,8 0,8 Soaps and detergents 2 27,0 0,4 9,8 0,3 Metallurgy 15 12,6 0,2 20,8 0,7 Others 6 1,5 0,0 4,7 0,1 Poultry 1 0,5 0,0 1,4 0,0

TOTAL 151 6379,0 100 3175,8 100 Source: EMCALI, 2006a

According with Table 3.3 the food and drink sector produces the largest BOD (52,3%), followed by services (15,9%). The others sectors has a range between 0.47 kg/day (poultry industry) to 769.98 kg/day (pulp and paper industry). TSS load contribution (Table 3.3) was drink and food (1310 kg/day), followed by services (552 kg/day), health care centres (438 kg/day), fibres and textiles (406 kg/day), pulp and paper (318 kg/day), The others sectors range between 1.43 kg/day (poultry industry) to 86.21 kg/day (pharmaceutics and chemistry industry) 3.2.4 Final wastewater discharge points from the city of Cali to Cauca River Untreated wastewater is directly discharged into the Cauca River at the following locations: i) South Channel; ii) Puerto Mallarino pumping station; and iii) Paso del Comercio pumping station. In the past (before year 2007) the collector on the Left Margin of the Cali River and the Floralia Pumping Stations used to be points of final discharges of wastewater generated by the city of Cali, but since December 2007 this wastewater has been carried to the WwTP-C where it undergoes treatment (CINARA and Universidad del Valle, 2008).



The different discharge points, their location and their respective flow and BOD load contribution are shown in Tale 3.4. This value came as a result of the studies and monitoring carried out in the discharge points in the city. Table 3.4. Flow and BOD load discharges from the final wastewater discharge points in the

three drainage systems in Cali. Year 2005 Drainage system Discharge point Flow

(l/s) %Flow from the total WW

BOD (mg/l)

Load (Kg BOD/day) Source

South South Channel 2417 30,1 68,5 14211,7 MANOV 2007 Margen IzquierdaCollector 808 10,2 157,3 10981,3 EMCALI 2005 North West Floralia Pumping Station 150 1,9 342 4432,3 EMCALI 2005 Paso del Comercio Pumping

Station 791 10 85 5809,1 EMCALI 2005

Puerto Mallarino Pumping Station 29 0,4 72,9 182,7 EMCALI 2005

Sludge from Puerto Mallarino DWTP 247 3,14 330,8 7059,5

EMCALI and Universidad del Valle,

2006 WwTP-C effluent with TPA

(BOD removal 40%) 142,1 41920,8 EMCALI, 2006a*

East

WwTP-C effluent without TPA (BOD removal 30%)

3417 44 165,8 48907,6 EMCALI, 2006a*

Source: EMCALI and Universidad del Valle, 2006 (*) Result from statistic analysis WwTP effluent mid 2005-mid 2006 The highest wastewater load and flow is coming from the treated effluent from the WwTP-C which paradoxically is treating the 68% (EMCALI, 2009) of the total wastewater produced in the city. The other discharge points do not receive any type of treatment but only transport the wastewater from the city to Cauca River. In addition, there is also presence of hazardous substances in the wastewater discharges especially from the South Channel. Such substances are phenol compounds, lead and mercury. Presence of these substances is critical since they all finally arrive to Cauca River which is also the water source for drinking water for the city of Cali. Additionally, Figure 3.8 shows BOD load percentages of the six discharge sites. The most significant is the WwTP effluent, with 42.6 ton/day, followed by the Southern Channel, with 13.6 ton/day.

Puerto Mallarino P. S.3,4 ton/day

4%

Collector Margen Izquierda

11,2 ton/day15%

Floralia P. S. 3,8 ton/day

5%Paso del Comercio P. S.

1,2 ton/day2%

South Canal13,6 ton/day

18%

WwTP- C effluent42,6 ton/day

56%

Total BOD load discharged to Cauca River = 75,8 ton/d

Figure 3.8. BOD load contribution of the final discharges to Cauca River Source: Monitoring of final discharges realized by EMCALI, august 2006 (EMCALI, 2006b)



3.2.5 Wastewater Treatment Plant - WWTP The Cañaveralejo Wastewater Treatment Plant WwTP-C is designed to treat 80% (7.6 m m3/s) and was estimated with a projection until year 2015. The tributary area of the municipal sewage system to be covered by the WwTP-C is 10,606 Ha. The wastewater control of pollution in the city of Cali is made through the use of the wastewater treatment plant of Cañaveralejo (WwTP-C) which at the present treats around over 68% of the total wastewater flow produced in the city (EMCALI, 2009). Average loads in 2007 were: 62,081 kg/d of SST and 67,876 kg/d of BOD, with a load removal average of 21,371 kg/d and 42,528 kg/d, respectively, which represents 37,34% BOD removal and 65,57% SST removal.

Figure 3.9. General scheme Cañaveralejo Wastewater Treatment Plant (WwTP-C) Source: EMCALI and Universidad del Valle, 2006

The wastewater influent to the plant comes from: the General collector (by gravity) and the Cañaveralejo, Navarro and Aguablanca pumping stations. During the year 2007, the average influent flow rate ranged between 3,41 m3/s and 4,18 m3/s, with an annually average of 3,79 m3/s. Figure 3.10 shows the average of flows during year 2003 to 2007, it shows the increase of influent flow.

2,02,22,42,62,83,03,23,43,63,84,0

2002 2003 2004 2005 2006 2007 2008

Ave

rage

Flo

w fo

r yea

r (m

3 /s)

Figure 3.10 Average influent flow WwTP-C during year 2003 to 2007

Note: *Average January – September Source: EMCALI, 2007d

The plant began operations in december, 2001. During its first year and a half of operations it achieved its normal operation. Later, starting in 2003, a decrease in BOD contaminant

*



load discharged by the city into the Cauca River basin (EMCALI and Universidad del Valle, 2006). It can operate in two ways: through conventional primary treatment or through advanced primary treatment (TPA). The conventional treatment consists on a simple sedimentation whereas the TPA consists on the addition of ferric chloride (FeCl3) as coagulant and organic polymer to enhance flocculation and improve the removal of solids. The components of the WwTP-C are: a) Waterline, the water line scheme and its main components is shown in Figure 3.11 (within this waterline is also found a flow mixing chamber) and b) Sludge line (Figure 3.12). Additionally there is odor control through a system called soil beds.

Coarse screen (2)

Fine screens (6)

Primary settling tanks

(8)

pumps

Aerated grit removal

(6)

FeCl3

PolymerPUMPED

INFLUENT

CAUCA RIVER

EFFLUENT

Coarse screen (2)

Fine screens (6)


(8)

pumps


(6)

FeCl3

PolymerPUMPED

INFLUENT

CAUCA RIVER

EFFLUENT

Coarse screen (2)

Coarse screen (2)

Coarse screen (2)

Fine screens (6)

Fine screens (6)

Fine screens (6)


(8)

pumpspumpspumps


(6)


(6)


(6)

FeCl3

PolymerFeCl3

PolymerFeCl3

PolymerPUMPED

INFLUENTPUMPED

INFLUENTPUMPED

INFLUENT

CAUCA RIVERCAUCA RIVERCAUCA RIVER

EFFLUENTEFFLUENTEFFLUENT

Figure 3.11. Water line scheme Note: (#) Quantity of units

Source: CINARA and Universidad del Valle, 2008

Figure 3.12. Sludge line scheme Source: CINARA and Universidad del Valle, 2008

Since 2008, biogas generated at the WwTP-C is being used for energy generation, which represents EMCALI a saving of 70% in energy costs (approximately $1000000 pesos per year) to operate and maintain the plant. This technology uses methane gas taken from the wastewater treatment process for its energy auto-supply through two generators with a capacity of one thousand kilowatts (1000 Kw) each. (DAGMA, 2008). Table 3.5 shows the comparison between the original design components and the components that are in operation. In this regard it is important to notice that not all the components operate at the same time due to current lower treatment capacity in comparison

MIXING

Sludge heating

Sludge pumping

Digesters

Thickener Sludge storageSludge dewatering

Final disposition

in landfill

MIXING

Sludge heating

Sludge pumping

DigestersDigesters

ThickenerThickener Sludge storageSludge storageSludge dewateringSludge dewatering

Final disposition

in landfill

Final disposition

in landfill



with original design, year (2007) average influent around 3,79 m3/s vs. original average influent flow of 7,60 m3/s. In practice, all units are used by periods switching them off and on so that their regular operation is not affected by lack of use.

Table 3.5. Comparison of design and current operation parameters in the WwTP-C. Characteristic Design

(2001) Year

(2009) Average influent flow (m3/s) 7,60 5,17 BOD removal with TPA (%) 42± 5 39.5 BOD removal without TPA (%) ≥25 34.0 TSS removal with TPA (%) 63± 5 66.8 TSS removal without TPA (%) ≥50 57.0 Grit removal chambers 6 4 Sedimentation 8 6 Digesters 4 3 Energy generators 2 2 H2S purifier 2 2 Sludge dewatering units (filter press) 7 3

Source: EMCALI (2001a), EMCALI (2009)

Chapter 4 Wastewater pollution control in Colombia and in the Upper Cauca RiverBasin


4 WASTEWATER POLLUTION CONTROL IN COLOMBIA AND THE UPPER CAUCA RIVER BASIN

4.1 HISTORICAL EVOLUTION IN COLOMBIA 4.1.1 Institutional framework Environmental institutionality in Colombia starts by the creation of the Natural Resource Division of the Ministry of Agriculture in 1952. The first standards are issued (Law 2 of 1952 for Forest Reserves) in order to protect the forests and regulate their exploitation. This defined seven major reserve areas for the protection of the soil, water and wild life. The management is centralized and there is total financial dependency from the total nation’s budget. The initial environmental regional institutions dedicated to promote the integrated and coordinated development of natural resources in their jurisdictions start in the decade of the 50’s, based on the framework of the theories of the Economic Committee for Latin America and the Caribbean, CEPAL. The first of these institutions was the Corporación Autónoma Regional del Valle del Cauca (CVC), created through Presidential Decree 3110 of 1954) which is created reviewing the Tennessee Valley Authority Model (TVA). CVC served as the model under which the other 18 Regional Autonomous Corporations were created between 1960 and 1988. The original model proposed basin management, but the concept was unaccepted because each department wanted to have its own development corporation and the bio-geographic unity concept did not progress. The roles of the different CARs were different. Therefore, it was difficult to define their profile and vocation and they reported to several entities such as the Ministry of Economic Development (1960 – 1968), Ministry of Agriculture (1968 – 1976) and later to the National Planning Department (1977 – 1993). The CARs functions were limited in 1987 and some of the roles are transferred to entities specialized in infrastructure, telecommunications, public services and environmental sanitation. In 1968, the National Institute of Natural and Renewable Environmental Resources (INDERENA) was created under the Ministry of Agriculture. During this period, the National Natural Resource Code to regulate environmental issues is created (Law 2811 of 1974) Decree-Law 2811 of 1976, the National Code for Natural Resource Management (CNRN) first created a series of government intervention mechanisms (e.g. economic incentives and grants/aids, wastewater pollution charges, environmental zoning, and the definition of environmental emergencies) such as the environmental information system to be used as a tool for developing an environmental policy. This new national code ordered arranging and keeping a current environmental information system that provided physical, economical,



social, legal, and other kinds of relevant data about the environment and the renewable natural resources. With the Law 2811, 1974 National Code for Natural Resource Management (CNRN) was developed Decree 1594, 1984, together with law 9, 1979 known as the Sanitation National Code established the proceedings and measurements to carry out regulation and control of discharges and regulates the uses of water and wastewater. Regarding wastewater, Decree 1594, 1984 defines the discharge limit of hazardous substance to open body waters and sewerage systems; it establishes the permit of wastewater discharges, establishes the quality criteria for the uses of water, pollution compensation tax and environmental studies impacts. In 1991 the Political Constitution of Colombia granted environmental protection the status of collective right, thus providing it with protection mechanisms made available to citizens, particularly in the form of community or group actions, and exceptionally in the form of writs for the protection and enforcement of constitutional rights. In compliance with the provisions set forth in the 1991 Political Constitution of Colombia, the Ministry of the Environment was established per Law 99 of 1993. This law provided environmental management in Colombia with a systematic, decentralized, participatory, multi-ethnical and multi-cultural dimension leading to the establishment of several scientific institutes in accordance with Law 99 of 1993. Law 99/1993 created the Ministry of Environment and radically changed the institutional management and environmental authority structure in Colombia and defined the Environmental National System. The entities of SINA are: Ministry of Housing, Environment and Territorial Development and its institutes, environmental authorities, the departments, districts, municipalities and non governmental organizations. Law 99 considered the creation of urban environmental authorities for the municipalities, districts or metropolitan areas with populations equal or greater than one million inhabitants. Bogotá, Medellín, Cali and Barranquilla, have these institutions due to the fact that they are the largest urban centres of Colombia. Starting on March 1, 2003, the national central administration was reduced, merging several ministries. The Ministry of Environment merged with the Ministry of Development and changed its name to Ministry of Housing, Environment and Territorial Development. Figure 4.1 shows the institutional organization for the wastewater management. Functions of national, regional and local actors are attaching in the Annex 1 4.1.2 Policies and regulations Different laws and decrees for the wastewater pollution control were proposed and implemented together with the evolution of these institutions. Table 4.1 shows a chronological chart of the Colombian pollution control standardization.



Presidency of Colombian Republic

Ministry for the environment, housing and development

MAVDTMinistry for

social protectionMinistry for

agriculture and rural development

Ministry of finance and public credit

Regional corporation

(CAR)

Departments

Municipalities

Public services companies

Local organizations

Irrigationassociation

Public services comisión(SSPd)

Water and sanitation regulatory comission

(CRA)

Vice-ministry for the environment

Directive for water and sanitation

Vice-ministry for housing and

development

Directive for housing

Directive for development

Vice-ministry for health

Directive for public health

Environmental health

Nacional council for land uses

Colombian institute for rural development

National planning

department

Ideam

Directives for the territory

Directives for the territory

Public heatth offices

Public health offices

Direction forsustainable rural

development

Directive for urban development and

environmental policies

Local Level

Regional Level

National Level

Findeter

UMATA

Figure 4.1 Colombian institutional structure for the management of the water resources



Table 4.1 Chronological history of the main legal standards related to waste management Regulation Relation with the wastewater management

Political Constitution of Colombia

It establishes that the state has the responsibility of protecting diversity and integrity of environment, promote environmental education and control environmental deterioration by implementation of fees or pertinent punishments

Decree –Law 2811 1974 National Code for Natural Resource Management (CNRN)

It establishes the prevention and control norms to avoid contamination of the water resource and guarantee quality of water for posterior use.

Decree 1541 1978 Includes the classification of the water bodies in function of their capacity to receive discharges and establishes the mandatory request of discharge permits for all individuals having or requesting water concessions.

Law 09 1979 (National Sanitary Code)

It establishes the proceedings and measurements to carry out regulation and control of discharges.

Decree 1594 1984 It is the regulation norm from the national code of natural resources. Together with law 9, 1979 regulates the uses of water and wastewater. Regarding wastewater, it defines the discharge limit of hazardous substance to open body waters and sewerage systems; it establishes the permit of wastewater discharges, pollution compensation tax and environmental studies impacts.

Law 99 1993 It establishes the pollution compensation tax when discharging wastewater to open water bodies. This legal figure was seen as a sanction that could punish polluters and as an instrument that could finance water protection as well

Law142 1994 (Public water companies regimen)

Establishes the competency of the municipalities to ensure efficient sewage service provision in a system that includes waste water treatment and final disposal.

Law 373 1997 It regulates the efficient use of water so that production of wastewater can be minimized.

Resolution 372 1998 Minimal tariffs to the pollution compensation tax of both Biochemical Oxygen Demand (BOD) and Total Suspended Solids(TSS)

Resolution 1096 2000 (Technical Rules for Drinking Water and Basic Sanitation sectors)

Setting of technical criteria for the development of basic sanitation projects. Among these, those of basic sanitation, in each and every one of its phases.

Decree 1729/2002 (River Basin Planning)

The ordering of river basins is set under the control of the competent environmental authority. It seeks to plan a sustainable use of water and related natural resources in order to conserve, Project or restore the natural ability to regulate water quality and quantity

Law 812 2003 (National Development Plan 2002-2006)

It establishes the programme of “Integrated water management", with emphasis in prevention and control pollution of water resources, based in the formulation and implementation of the National Plan for the Wastewater Management according to the CONPES 3177/ 2002 document

Decree 3100 2003 It regulates the pollution compensation tax to punctual discharges and establishes the Sanitation and management of wastewater discharges plan. Determines that the chargeable substances are the BOD and the SST. The minimum tariffs to be charged are included in Resolution 372 of 1998 of the MAVDT.

Decree 1220 2005 Establishes that all Project, work or activity requiring an environmental license shall include the corresponding discharging permit.

Resolution 1433 2004 It regulates the formulation of the Sanitation and management of wastewater discharges and forces the sewage system operators to establish the specific discharge sites reduction.

Source: Adapted from Londoño and Parra (2007) The country has a large amount of policy documentation developments in terms of wastewater management. These have been useful in the articulation of the actions and have promoted the processes within stakeholder entities. Public policies have been set for the Colombian water supply and basic sanitation sectors (2001), with the objective of proposing water resource integrated management strategies and to focus state actions to guarantee access to water supply, sewage and sanitation



services for lower income populations. There are also policy guidelines set by the Economic and Social Policies National Council - CONPES, created by Law 19 of 1958, under the direction of the Presidency of Colombia. Table 4.2 shows some main CONPES documents related with the wastewater management.

Table 4.2 Main CONPES “guidelines policy documents” related with the wastewater management

CONPES Relation with the wastewater management

CONPES 3177 2002

“Priority actions and guidelines for the formulation of a national plan for the wastewater management” which proposes different water quality improvement strategies as the foundation for feasibility and economic, social and environmental sustainability, such as the implementation of a Plan for Sanitation and Management of Wastewater Discharges (PSMV), as a planning instrument.

CONPES 3246 2003

“Policy guidelines for the water supply and sewage sector” It defines the guidelines for the management of the water supply and sewerage systems. It looks fro strategies to reach economic subsidies for the tariffs, new tariffs based on the efficiency and quality criteria in the delivery of public services

CONPES 3253 2003

“Strategic importance of the entrepreneurial modernization in the water supply and basic sanitation sectors” establishes the importance of the Entrepreneurial Modernization Program (PME), through which the MAVDT executes its policy of promoting the private sector’s participation in drinking water and basic sanitation services

CONPES 3305 2004 “Alignments to optimize the urban development policy” presents alignments for the optimization and implementation of urban development policies.

CONPES 91 2005

“Goals and strategies of Colombia for the achievement of 2015 Millennium Development Goal” which defines actions to be implemented and the national goals that may be met by 2015 to comply with the eight millennium development objectives. One of these objectives is environmental sustainability.

CONPES 3343 2005

“Sustainable development alignments and strategies for the water, environment and territorial development sectors" Guidelines and strategies for sustainable development of the water, environmental and land sectors. It strives to strengthen the environmental governability to make it efficient, effective, transparent and equal.

CONPES 3383 2005

“development plan of the water supply and sewage sector” Plan for the development of water supply and sewerage systems so that total coverage are met considering good quality and quantity. Year 2019 is taken as the horizon year so that an integrated management is reached as well

At regional level there are different strategies aimed to plan and guarantee the environmental sustainability of the Valle del Cauca department. However, it is important to highlight that the water management approach followed in Colombia is not at the river basin scale. Instead each one of the provinces works independently depending on its political jurisdiction. Decree 2811, 1976: Policy of control for users of Cauca River. It establishes the prevention and control norms to avoid contamination of the water resource and guarantee quality of water for posterior use. Following, the main strategies are summarized: Agreement 014, 1976: Policy of control for users of Cauca River: it establishes the

prevention and control norms to avoid contamination of the water resource and guarantee quality of water for posterior use.

Plan for the environmental management in the region of Valle del Cauca 2002-2012

“Participación con compromiso”. This strategy orients in a coordinated way the management and administration of the renewable natural resources.



Plan for the development of the department of Valle del Cauca 2008-2011 “Buen Gobierno, con seguridad lo conseguiremos”, which its oriented to the formulation and implementation of programmes related with social development and environmental management

Plan triennial, PAT.2007-2009, which defines the actions to accomplish the targets set

in the Millennium developing goals through the established national policies. Pact for the recovery of the Cauca River 2001: It is a pact signed among the Ministry

for the environment, regional corporations-CVC the department of Valle del Cauca and the municipality of Cali. The main goal is to formulate a plan for the integrated management of the Cauca River basin. The formulation of the plan must be established based on the participatory approach from the municipalities, communities and industrial sectors involved in the uses of the river basin.

Plan for the integrated management of the Cauca River basin-2005; It establishes the

strategies and measures, to be followed by all the involved parties, to protect, recover, conserve and manage in a sustainable way the Cauca River.

Departmental Water and Sanitation Plan for the entrepreneurial management of the

water supply, sewage and sanitation services, which offers the strategies to accelerate the coverage growth and the utilities quality. Presently, it is under construction process by the Institute of Research and Development of Water Supply, Environmental Sanitation and Water Resources Conservation -– Cinara de la Universidad del Valle

At local level the local policies which sustain the urban water management in Cali are: Plan for the development of Cali area 2008-2011 “Para vivir dignamente”, oriented

towards the proposal and execution of macroprojects related to the wellbeing and social, environmental and economic development of the city.

Master plan for Cali 2000-2020. It coordinates the use and destination of the public

areas to ensure the social-economical development considering the needs and interest of the involved population. Regarding the environment it defines land uses, protected areas, risk areas, urban growth. Likewise it defined the uses of the natural resources in the city.

Sanitation and management of waste-discharges plan PSMV (EMCAL, 2007). It

includes programs, projects and measures for the management of wastewater in the city following quality standards and policies defined by the environmental authority in the region (DAGMA). The plan encompasses recollection, transport, treatment and final disposition.

Environmental management Plan for the city of Cali. DAGMA 2005-2019. It includes

all the decisions and strategies to de developed by the different stakeholders in the city (at institutional, social and economical level). Such strategies are aimed to improve the quality of life of the community as well as to improve the economical productivity.



Plan for the solid waste management in Cali-PGIRS 2002. This plan was developed to be mainly responsibility of the municipalities. Its mission is to establish an integral management of the solid waste taking into account all aspects from the production of the waste until its final disposition and considering strategic aspects like recycling and reuse.

Resolution 376-2006 and 019-2007. Set by DAGMA, these resolutions define goals for

the reduction of emissions and waste discharge to water bodies in Cali. Specifications for the uses of the different rivers in Cali are also set. It also set deadlines (to be accomplished by the public agencies) in reducing the waste discharge to the rivers.

Environmental municipal management system (SIGAM): Implemented by the

municipality, it establishes environmental profiles and identifies responsibilities and responsible for control, management and control of the environment in Cali.

Environmental agendas. The latest agenda was established in 1998. The agendas are

developed at local level to show the current state of the environmental resources inside the city. They also formulate approaches to follow up the development of environmental strategies.

4.1.3 Pollution control strategies from policies and regulation The present standard and political framework promote the creation of different strategies related to the pollution control, which include policies such as the Cleaner Production and the creation of command instruments such as Decree 1594 of 1984 and economic instruments such as the payment of environmental tariffs, among others. Prioritization of Projects and Investments: Resolution 1096/ 2000 (Technical Regulatory for Drinking Water and Basic Sanitation sectors), defined the priority scheme for the implementation of water and sanitation sector projects in order to satisfy the sector’s needs, rationalizing resources and investments in a way that guarantees the economic sustainability of the projects. Under these schemes (see Figure 4.2), priority is given to the drinking water supply works, sewage coverage and solid waste collection and disposal coverage, instead of the construction of the WwTP. The main characteristic is the sectorized wastewater management orientation and the “end of the pipe” proposed solutions. This priority scheme has not been considered in the infrastructure works because, for instance, some municipalities have been found to have a WwTP- C, without having solved the sewage problems and without having built the final carrier to take wastewater to treatment. On the other hand, through the CONPES 3177 of 2002 document, the guidelines for the National Plan of Wastewater Management were proposed in order to promote the nation’s water resources quality improvement. This plan proposes a prioritization strategy for the river basins, including the following aspects: Basins with serous environmental problems generated by domestic wastewater

discharges.



Is solid waste collection lower than the limit? Broader coverage of waste collection

coverage

Yes

NO

Do you have controlled solid waste disposal? Sanitary Landfill

NO

Yes

You have or do not need wastewater treatment?

Domestic wastewater treatment system NO

Yes

May you implement a solid waste recycling program with technical and economic

sustainability? Recycling of solid waste

Yes

NO

Is the drinking water coverage lower than the allowed limits?

Broader drinking water coverage Yes

NO

Is the sanitary sewage delayed with respect to the potable water being above

limitsBroader coverage of sanitary sewage Yes

NO

PRESENT THE PROJECT WITH RAS

The municipality must develop projects:

Figure 4.2 Flow chart of the investment prioritization

Source: Ministerio de Desarrollo Económico (2000). Municipalities with domestic wastewater that cause environmental river basin

problems. Impact level of each municipality over the waste water receptor bodies and the

downstream effect. Basic public services infrastructure development level.

Capacity of administration and management of the wastewater treatment systems. This strategy will allow reducing the impact over water resources, strengthening the institutional management according to its potential and regional and local priorities at long term (10 years), mid term (5 years) and short term (2 years), within a possible funding scenario and defining the quality objectives for the water bodies and the corresponding sanitation goals to gradually decrease contamination levels. This plan set priorities for 300 specific areas (municipalities and basins).



The Water Rational Use Policy (law 373/1997) seeks that each service company that use water as main resources (aqueduct, sanitation, irrigation, drainage, hydroelectric production) define a program that contains a set of projects and action in order to: Reduce water louses ( in accordance with Water regulation commission goals) Increase community awareness about adequate water use Promote rational use via incentives defined by CRA (via tariffs), CARs and services

companies Water reuse (such reuse has not been regulated yet) Increase consumption measurement in water service and irrigation Gather information about water uses/ users Increase use of low water consumption technologies

Such program lasts five years the investment made in rational water use will be into variable cost and will be considered as a plus in order to access loans and other economic stimuli (Guio, 2004). Pollution compensation tax: Developed in Colombia by the Ministry of Environment through Decree 901/1997, charging for the compensation tax generated a change in the Colombian environmental policies approach, which up to that date was based on the standardization control and command concepts, and moved towards the use of economic instruments that promote decontamination based on the economic feasibility. Initially the tax is only introduced for two contaminating substances, BOD and TSS. However, none of the other 30 contaminants listed under Decree 1594/1984 have been regulated. This has not permitted the application of this tax on chemical contaminant emissions caused by industrial activities (Quintero, 2007). Some of the difficulties encountered with the application of such decree were the following (ANDESCO and CEDE, 2004): The water source assimilation capacity and its uses were not considered. The contaminating load effect in the receptor body and the technical and socio-

economic environmental context were not considered. The methodology did not have unified criteria to calculate decontamination goals and

the agreement processes for the methodologies were deficient. In many cases, this caused a lack of coherence between the treatment objectives and the effort related to the design and construction of treatment systems, up to the point in which it could be more profitable to contaminate than to invest in decontamination.

During the validity of the decree, they way in which the service providers were going to recover costs associated to the compensation tax was not clear. Since the operators made unrecoverable payments, financial problems emerged for many enterprises that allocated large amounts of money for the payment of the compensation tax, such as EMCALI, which allocated S$17 millions1 and Bogotá, which paid US$6 million between 1999 and 20022

1 1US$ = $2,507.96 (Representative Market Rate at 2002) 2 Cited by ANDESCO and CEDE, 2004



Decree 901 did not allow crossing accounts between the payment of the contribution taxes and the treatment investment, such as collectors or interceptors. Therefore, EMCALI invested approximately US$150 million in a Wastewater Treatment Plant with capacity to treat 100% of the discharges, as well as Empresas Públicas de Medellín, which would invest approximately US$331 million in recollection and transportation systems in the North Plant located in the city of Bello3.

Decree 901 of 1997 was replaced by Decree 3100 of 2003 and this decree was partially modified by Decree 3440 of 2004. These decrees defined that the implementation, invoicing, charge and collection of this taxi s responsibility of the Environmental Authorities and that the collected resources under this concept are the entity’s own funds, which must be exclusively devoted to water decontamination investment projects and monitoring of water quality according to provisions of Law 812 of 2003. Setting of contamination load reduction goals was also clearly defined and the payment of compensation taxes will only be done in the basins identified as priority, according to the quality conditions. Finally, it is established that the global contamination load reduction goal will be defined every 5 years for each specific water body, defining it for each of the contaminating agents covered by the tax. Water Usage Tax: taxes for the use of water were regulated under Law 99 of 1993. Article 43 of Law 99 defines the different water uses, for water consumption, recreation, irrigation, or any other industrial or agricultural activity made by natural or legal individuals, public of private, that will generate a tax charge (1% of the total investment), which will be used to pay for the recovery, conservation and surveillance cost of the river basin that feeds the respective water source. According to the valid institutional scheme, the MAVDT is in charge of setting the minimum taxes. The Environmental Authorities are in charge of setting and collecting the taxes in their respective jurisdictions. These environmental authorities fix a price per cubic meter of captured water, which substantially varies between municipalities. Usage taxes were recently regulated by Decree 155 of 2003 and Resolution 240 of 2004. It is important to highlight that Decree 155 of2003 includes mechanisms to recognize the total basin development and management plan costs mentioned in Decree 1729 of 2002, considering river basin investments made by the Corporación Autónoma Regional (ANDESCO and CEDE, 2004). Saving and Efficient Use of Water: With regards to water supply and sewage services, Law 373 of 1997 determines that the service providers must present the efficient use and saving of water program to the regional autonomous corporations and the other environmental authorities every five years, in order to obtain its approval. This law sets a one year term for the service providers to implement a consumption gauging program for all users. It also establishes the obligation of the CRA to set annual loss reduction goals, establishing basic consumptions, and the definition of a tariff structure aimed at promoting the efficient water use and saving.

3 Cited by ANDESCO and CEDE, 2004 from Empresas Públicas de Medellín. Contribution taxes.. Presentation – December, 2003.



Reuse: An important aspect for the optimization of the water resource utilization is the reuse of water in agricultural, industrial or environmental activities. Water reuse considers a process to obtain a specific quality that does not affect human health or the environment in its new usage. Law 373/97 defined a series of principles in order to promote the adequate use of and the water savings practices. According to Law 373, Article 5, water reuse is mandatory. The surface, ground or storm waters in any activity generating liquid effluents, shall be reused in primary and secondary activities when the technical and economic process are worth it, providing advice according to the socio-economic analysis and the environmental quality standards. The agricultural sector is also the most important potential user of the domestic wastewater. The demand of groundwater or surface water for direct use in the agricultural sector represents 48 % of the total municipal demand. However, this is not done in a technical manner. The contaminated water of rivers affected by large wastewater discharges are used for irrigation purposes, without receiving previous treatment. This situation on a long term basis may affect the soil and aquifers quality, and on a short term may become a health risk for the users of the agricultural products, if these are not properly managed (Hoof and Herrera, 2008) National standards related to the quality of reusable water has limitations. Decree 1594 of 1984 of the Ministry of Health, in its Article 40, Paragraph 1, defines the microbiologic quality of water in relation to total and faecal coliforms of water to be used for crops irrigation of fruits that are eaten raw. However, standards for industrial crops are not included. Therefore, it is recommended to use the WHO standards, without contradicting Decree 1594. Command Instrument – Decree 1594 of 1984: This decree defines the allowed limits for contaminant load discharges into water bodies or sanitary sewages. Likewise, it establishes the sanitation interest substances, compliance plans, and defines the procedure to implement preventive and penalty measures due to violation of environmental standards, among other aspects. It also establishes the resource quality criteria for its diverse uses. Article 72 defines the direct wastewater discharge limits to water bodies which are presented in Table 4.3 Table 4.3 Wastewater discharge limits to open water bodies. Decree 1594/1984, Article 72

Reference Existing user New user pH 5 a 9 units 5 a 9 units Temperature < 40°C < 40°C Floating matter Absent Absent Fat and oils Removal > 80% load Removal > 80% load Domestic or industrial suspended solids Removal > 50% load Removal > 80% load BOD Domestic waste Industrial waste

Removal > 30% loadRemoval > 20% load

Removal > 80% load Removal >80% load

Article 72 defines the direct wastewater discharge limits to public sewerage systems which are presented in Table 4.4



Table 4.4 Wastewater discharge limits to public sewers. Decree 1594/1984, Article 72 Reference Existing user New user

pH 5 a 9 units Temperature < 40°C < 40°C Acids, bases or acidic solutions Absent Absent Settled solids 10 ml/l 10 ml/l Soluble substances in hexane 100 mg/l 100 mg/l Domestic or industrial suspended solids Removal > 50% load Removal > 80% loadBOD Removal > 30% load Removal >80% loadMaximum flow 1.5 times average hourly flow 1.5 times average hourly flow Finally, Table 4.5 shows the limit concentrations of hazardous substances in the discharges, established in article 74.

Table 4.5 Standard admissible concentrations for the control of hazardous substances discharge. Decree 1594/1984, Article 74

Substance Unit Concentration (mg/l) Arsenic As 0,5 Barium Ba 5 Cadmium Cd 0,1 Copper Cu 3 Color Cr+6 0,5 Phenol compounds Phenol 0,2 Mercury Hg 0,02 Nickel Ni 2 Silver Ag 0,5 Lead Pb 0,5 Selenium Se 0,5 Cyanide CN- 1,0 Diphenyl poli-chloride Active agent concentration No detectable Organic mercury Hg No detectable Trichloride -ethylene Trichloride -ethylene 1,0 Chloroform Chloroform carbon extract Chloroform carbon extract Carbon Tetrachloride carbon Tetrachloride 1,0 Dichloride-ethylene Dichloride-ethylene 1,0 Carbon sulfide Carbon sulfide 1,0 Other organ-chloride compounds Other organ-chloride compounds 0,1 Organ-phosphate compounds Carbamate variety

Organ-phosphate compounds Carbamate variety 0.1

Pollution control in the industrial sector: This control was regulated through Agreement 014 of 1976 issued by CVC. Article 13 refers to the reduction of contaminating loads generated by domestic and industrial wastewaters, considering the treatment stages and the years specified for the implementation. Later, Decree 1594 of 1984 of the Ministry of Health, in its Chapter VI, Article 73, indicated that all industrial waste discharged into the sewage system by a new user shall have a removal load ≥ 80% in SS and BOD For he existing users, the removal load shall be ≥ 50% in SS and ≥20% in BOD. Pollution control in the agricultural sector: A study by the National Planning Department in 1994 estimated the organic matter daily production in Colombia in 8,420 tons of BOD, out of which 84% correspond to organic matter included in the agricultural



and livestock wastewater (Londoño and Parra, 2007), 9.5% of domestic origin and 6.5% of industrial origin. Although Decree 1594 of 1984 is directed to the control of specific and non-punctual wastewater discharges, there it no standardization directed towards the pollution control originated by the agricultural and livestock sectors discharges (non-punctual) due to the difficulty in quantifying the surface or sub-surface runoff and the fact that the current standardization has note evolved in this sense. Watershed Planning: Regarding watershed management, the CNRN established the environmental resources, land use and river basin plans as tools. However, before 1991 planning only was required in particular urgent conditions, not well defined. In addition, the financing sources for execute such plans were not well established. Only after law 99/93 and territorial development (law 388/1997) watershed planning gain the chance to become an effective mechanisms guarantee water resources sustainability. Law 99/93 defines environmental plans, land use and river basin plans as tool for municipal development. Environmental plans, guide natural resources administration in order to strength development process. There are three main tools: Regional Environmental Plan, Triennial Action Plan and investment Annual Plan. However the idea of integrated territorial development mainly developed in Law 339/97. There POT is defined as the mechanism that enable to promote an adequate land use, to protect the environment, to prevent disaster risk associated with settlements, to guarantee minimum services in urban expansion areas to promote a better use of territorial advantages Cleaner production: The implementation of the preventive approach for the control and reduction of the environmental impact of the asset and service production, in place of concentrating at the "end of the pipe" is named “cleaner production”. The CP is oriented to achieve a sustainable industrial development, through an economic efficiency that has a minimum negative environmental impact, including among others the waste minimization, eco-efficiency and pollution prevention strategies. Cleaner production strategies are varied and include good practices, with low investments, as well as the transfer towards cleaner technologies that in general, require large capital investments. Progress in the implementation of CP will mainly depend on policy-related factors: market demands, financial and public markets, etc. (Tamayo, 2008) In 1997 the Ministry of Environmental Affairs of Colombia adapted its National Cleaner Production Policy as a complementary environmental strategy to introduce prevention oriented approach into management practices of industry. The objective of this policy is to efficiently prevent and minimize the impact and risks for human beings and the environment, guaranteeing environmental protection, economic growth, social wellbeing and entrepreneurial competitivity, based on the introduction of the environmental issues in the productive sectors as a long term challenge.



4.2 WASTEWATER POLLUTION CONTROL IN THE UPPER CAUCA RIVER BASIN

4.2.1 Background Initial studies of the Cauca River contamination problems were made in 1964, when J.E. Donaldson and C. Dunn, professors from Tulane University, USA, made the “research of waste contributing to the contamination of the Cauca River” study, which had the support of CVC and Universidad del Valle. In 1967, Engineer Armando Cubillos, professor from Universidad del Valle, analyzed the Cauca River water quality in the sector between Navarro and the Guachal River mouth. Based on the results of this analysis of the water samples and its comparison to work done in 1964, Cubillos came to the conclusion that the river’s water quality suffered an increased deterioration (Galvis et al., 2001). In 1969, CVC initiated an evaluation of the Cauca River water quality, finding some sections with relatively low DO levels compared to the previous years’ registered values. The conclusion of the evaluation determined the need to control water pollution (Galvis et al., 2001). During the same year, the evaluation of the water quality of the tributary rivers and industries that mainly contribute to contamination and the monitoring of the final emitters of the sewage system of the city of Cali (Galvis et al., 2001). In 1973, CVC subscribed a technical cooperation agreement with the Pan American Health Organization, PAHO, in order to develop a more detailed study of the river conditions. This study included the water quality analysis through the location of fixed sampling stations and the collection of information on water uses, such as irrigation, municipal and industrial supply. The agreement with PAHO considered for the first time ever, the application of numeric simulation models. The previously mentioned study set the bases to issue Agreement 014 dated November 23, 1976, which set the standards for pollution control in the Cauca River Basin, in the territory under the jurisdiction of CVC (which back then included the entire geographic valley of the Cauca River), within the Pollution Control Program, which proposed the implementation of activities by stages for the existing river basin users, as follows:: Preliminary treatment until 1981, primary treatment until 1985, secondary treatment until 1990 and the mandate for new users to comply with the regulations since the first moment operations start. The Ministry of Health in 1984, through its Decree 1594, regulated water uses according to its quality and liquid waste discharges. Presently and since 1980, CVC has historic records of monitoring activities held in the Cauca River stations, the tributary rivers, the industries and municipalities. These samples include approximately 57 parameters between the hydraulic, physical, organical, inorganical, and microbiological (Galvis et al., 2001). The sampling frequency can be monthly, quarterly or semi-annually, depending on the kind of water source. Following is



the current sampling frequency made by CVC at the Cauca River, its tributaries, the industries and municipalities Cauca River: 19 stations along the Cauca River are monitoring with quarterly frequency Tributary rivers: 41 tributary rivers are sampling and monitoring. Which 30 are direct

tributaries of the Cauca River. Quarterly frequency. Industry: the CVC has been periodically controlling and monitoring the wastewater

discharges from around 200 industries located in the Cauca river basin, whose wastewaters are discharged to the Cauca River and its tributaries. Half-yearly frequency

Municipality: sampling and monitoring discharges from municipalities in the influence area of CVC are realized with half-yearly frequency

For the city of Cali, with its urban perimeter under DAGMA’s jurisdiction, the Empresas Municipales de Cali – EMCALI carry out an annual sampling of the final city contaminants as part of the environmental declaration reported to DAGMA (CVC and Universidad del Valle, 2003). Likewise, CVC makes quarterly samples of the main sewage system final effluents of Cali discharges into the Cauca River at the Eastern canal Oriental, South Canal and the General collector. Since 1997 until 2007, CVC and Universidad del Valle developed the Cauca River Modelling Project – PMC, in the section between the Salvajina Dam (Cauca) and the municipality of La Virginia (Risaralda). The research focused on the following aspects: : a) Analysis of the actual and projected technical aspects related to the hydraulic, sedimentary, geologic, morphologic and water quality characteristics b) Implementation of an integrated mathematical modelling system of the Cauca River and its tributaries, and c) Estimate and evaluate the impact over the Cauca River caused by the different interventions, as well as the effects of the works planned for different objectives, based on the characterization of the different Cauca River aspects and applications, among which are the flooding study development and the contamination control plans modelling (Ramírez et al, 2005) 4.2.2 Contaminant load discharges into the Cauca River There are 39 tributaries between La Balsa and Anacaro, with a strong slope and considerable short-lasting spates. From the total organic discharges (219 ton/day BOD in 2005) to the Cauca River, 56.7% (124 ton/day) is discharged by means of these tributaries. The most critical tributary rivers in terms of BOD load discharges are: Palo (12.1%) Tuluá (9.9%), Guachal (9.3%), Cali (7.5%), Quebrada Zanjón Oscuro (3.1%) and Cerrito (3.1%) rivers (CVC and Universidad del Valle, 2007a) Regarding wastewater discharges into the river, CVC has been periodically controlling and monitoring wastewater discharges from around 200 industries located in the geographical river basin, whose wastewaters are discharged to the Cauca River and its tributaries. Figure 4.3 shows the BOD loads discharged into the Cauca River basin in the section Salvajina –La Virginia between 1979 and 2007. Figure 4.3 shows that sectors like the sugar cane production, paper industry and coffee production have reduced their polluting contribution to the Cauca River.



0

20

40

60

80

100

Sugar CaneIndustry

Paper Industry Coffee OthersIndustries

Cali OtherMunicipalities

BO

D (t

on/d

ay)

1979

1997

1999

2001

2003

2007

Figure 4.3 BOD load discharged to Cauca River. Section: Salvajina – La Virginia.

Period: 1979 – 2007. Source: Data suministred by CVC

In year 1979 the sugar production industry spilled near 100 ton/day of BOD load to the river causing great impacts in the quality of the water resource and affecting the aquatic ecosystems. During the last years, these figures have remained at approximately 5 ton/day of BOD. A similar behaviour presents the paper industry. Although, from Figure 4.3 it can be seen a decrease in the average industrial load discharges to Cauca River, there is no monitored evidence regarding the operation of the industrial treatment systems and sporadically it had been found specific discharge points with high pollution loads. Likewise, the municipal wastewater load discharges have increased during the years, as a result of the growth of the population, the development of the industries within the cities and the low implementation of systems of wastewater treatment. After the wastewater treatment plant of Cañaveralejo (WwTP-C) initiated operations in 2002, a reduction in the contamination load discharged by the city of Cali in 2003 showed a decrease. For 2007, these values remain at approximately 80 ton/day. Wastewater discharges from Cauca department: Cauca River in the Cauca department from its source to the sector located near Desbaratado River (in the border with the Valle del Cauca department) receives in average a BOD load of 20,86 ton/day (see Figure 4.4) being the municipal sector the highest contributor with a 68% of the total BOD load. The river in its course through the department receives indirect or direct pollution from the nearby municipalities as well.



Meat Production,

1.43 ton/day (7%)Industries, 5.15

ton/day (25%) Municipalities, 14.27 ton/day

(68%)

Figure 4.4 BOD load discharges in the Cauca River basin by different commercial, industrial and domestic sectors in the Cauca department

Source: EMCALI and Universidad del Valle, 2006. Regarding the discharges from the tributary rivers to Cauca River in the Cauca department, states that 47,1% of the total load (9,8 BOD ton/day) is discharged by the rivers located after Salvajina dam namely Palo, Zanjón Oscuro, Quinamayó and Ovejas rivers (EMCALI and Universidad del Valle, 2006).

Spilled total charge

La Tabla river mouth;0,32; 2%

Ovejas rivers; 0,45; 2%

Quinamayo river; 1,94;

9%

Other rivers; 2,75; 13%

Zanjón Oscuro; 2,02; 10%

Palo river; 5,42; 26%

Cauca river (Popayan); 7,96; 38%

Figure 4.5 BOD load discharged in the department of Cauca. Year 2003

Source: CVC, 2003 Wastewater discharges from Valle del Cauca department: In Figure 4.6, the contribution of BOD load in 2006 by the industrial and municipal sector, (monitored by the CVC to the industries, Cali and other municipalities) is shown. In the Figure 4.6, Cali is the municipal sector that contributes the most with BOD load (38%). Wastewater discharges from Cali Table 4.6 show the flows, BOD and TSS load discharges measured in the six different wastewater discharge points from the city.



Sugar cane (3.9 ton/d)

2%

Other industries (17.6 ton/d)

9%Coffee

(27.3 ton/d)14%

Other municipalities (66.3 ton/d)

34%

Cali (74.1 ton/d)

38%

Paper (5.9 ton/d)

3%

Total load discharge195 ton/day

Figure 4.6 BOD load discharges to Cauca River basin in the Valle del Cauca department in year 2006

Source: EMCALI and Universidad del Valle 2006

Table 4.6 Flows and BOD and TSS load discharges measured in the final wastewater discharge points. Years 2006 - 2007

Final wastewater discharges point Flow (l/s)

BOD (kg/day)

TSS (ton/day)

Margen Izquierda collector* 758 11183 6303 Floralia pumping station* 84 3803 1193 Paso del Comercio pumping station * 169 1248 975 Puerto Mallarino pumping station * 322 3410 3981 South Channel * 1710 13610 13960 Subtotal discharge without treatment 33253 26412 Average influent to WwTP-C (2007)** 3790 67876 62081 Average effluent from WwTP-C (2007)** 3790 42588 21392 total average value produced 6833 101129 88493 Value average value discharged 6833 75841 47804 Load removal in the WwTP-C (%) 37 66 Total load renoval in the city (%) 25 46 Notas: * Monitoring of discharges realizad by EMCALI August 2006 (EMCALI, 2006b) ** Operation Report of the WwTP- C . Year 2007 (EMCALI, 2007c)

According to Table 4.6, the city of Cali produces a total of 6.8 L/s of wastewater, with contaminating loads of 101.1 ton/day of BOD and 88,5 ton/day of TSS. The total load discharged into the Cauca River in 2007 was approximately 75.8 ton/d of BOD and 47.8 ton/day of TSS. Most of the contaminating BOD load comes from the city of Cali, through the WwTP-C effluent, which represents56% (42.6 ton/day), the Southern Canal with 18% (13.6 ton/day) and the Left Margin Collector, with 15% (11.2 ton/day) (See Figure 4.7)



Puerto Mallarino P. S.3,4 ton/day

4%

Collector Margen Izquierda

11,2 ton/day15%

Floralia P. S. 3,8 ton/day

5%Paso del Comercio P. S.

1,2 ton/day2%

South Canal13,6 ton/day

18%

WwTP- C effluent42,6 ton/day

56%

Total BOD load discharged to Cauca River = 75,8 ton/d Figure 4.7 Total BOD load discharged to the Cauca River from Cali city

Sources Notas: * Monitoring of discharges realized by EMCALI August 2006 (EMCALI, 2006b) ** Operation Report of the WwTP- C . Year 2007 (EMCALI, 2007c)

Having in mind that the city of Cali produced a total of 101.1 ton/day and 88.5 ton/day of BOD and TSS loads, respectively, (See Table 4.6) and that the load removal at the WwTP-C was 37% BOD and 66% TSS, the removal percentage of the total city load is only 25% of the load produced in the city of Cali. The industries in the urban area of Cali discharge directly their wastewater in the sewage system of the city. According to DAGMA in the period from 1998 to 1999 the total load discharged by the industrial and commercial sectors in the city was approximately 24% of BOD and 26% of TSS from the total wastewater load generated in the city. The main impact to the domestic wastewater is the contribution of hazardous substances present in the wastes from the industries such as the metal, dental, and mechanic industry. The WwTP-C is now receiving more than 56% of the total wastewater flow generated in the city of Cali. Characterizing the affluent to the WwTP-C, including the new locations (i.e. the collector on the left side and the Floralia pumping station) recently incorporated to the treatment, allows identifying, to a large extent, the amount of contaminant load from both domestic and industrial wastewater generated in the city of Cali. Domestic discharges account for 78% of the BOD load while industrial discharges represent the remaining 22%, the largest portion of which comes from the central collector that gathers wastewater from the foods and beverages industries. The largest contribution of these manufacturing activities is associated with high BOD and TSS loads and low pH values Domestic discharges generate the largest load of TSS accounting for 90% of the total load, while industries generate the remaining 10%. Other activities that generate contaminant load to the affluent at the WwTP-C are listed in Table 4.7 which despite having a relatively low load of contribution, they should give importance to them, since some of these activities generate inorganic substances, heavy metals or other hazardous contaminants which not only have an adverse effect on biological treatment processes, but also deteriorate the quality of the receiving bodies of water.



Table 4.7 Industrial discharges that generate a minor amount of contaminant load to the affluent at the WwTP-C

Activity Number of companies Contaminants

Chemists and pharmaceutical -Cosmetics and pharmaceutical Laboratories

9 Vegetal and animal organic material, metals, phenols, cyanides and acids

Textiles- cotton, wool 4 High alkalinity, pH, high total solids, BOD y COD, cyanides, phenols, phosphates, chlorine, manganese, nitrogen, sulphides and greases.

Health - Hospitals and clinics 12 Pathogens microorganisms, virus, micro-pollutants. Printers - Lithography and publishing house 5 Phenols, cyanides, metals, pH, Cr, Cu.

Metallurgy 7 pH, heavy metals, phenols, cyanides, Ni, Pb Services - Restaurants, commercial centres, terminal transport, airports 8 Organic matter, grease and oil, phosphates.

Paper 3 Na, Sulphides, pH, metals (mercury) Source: Adopted from EMCALI and Universidad del Valle, 2006 Figure 4.8 shows the percentage of the contribution of industrial and domestic contaminant load from the collector on the left side. It is worth noting that the largest load comes from domestic wastewater because there isn't a significant presence of industries in the area of influence of the collector, but rather a predominant number of service facilities such as shopping malls and hospitals

% BOD Lo ad Do mes tic

88.1%

% BOD Lo ad Indus tria l

11.9%

% TSS Lo ad Do mes tic

89.5%

% TSS Lo ad Indus tria l

10.5%

Figure 4.8 Loads of domestics and Industrial Wastewater in the Margen

Izquierdo Collector Source: EMCALI and Universidad del Valle, 2006

The largest impact of industrial wastewater on this collector is due to service facilities. However, the BOD and TSS loads generated by healthcare institutions account for 21% and 31% of the industrial effluent, respectively. This shows that these discharges have a large content of organic matter and biological contaminants Compared to other locations, the Floralia pumping station registers the highest concentrations of BOD. This characteristic may be the result of the large contribution of organic load generated by Cadbury Adams, which is a foods and drinking manufacturing company that generates 94% of the industrial load discharged into its area of influence. Figure 4.9 shows the percentages of both domestic and industrial contaminant loads



% BOD Load

Industrial50.5%

% BOD Load

Domestic49.5%

% TSS Load Industrial

8.4%

% TSS Load Domestic

91.6%

Figure 4.9 Loads of domestics and Industrial Wastewater in the Floralia Pumping Station Source: EMCALI and Universidad del Valle, 2006

4.2.3 Wastewater management of municipalities of Valle del Cauca department Except for the city of Cali, the other 33 departments of Valle del Cauca discharge their wastewater directly into the Cauca River, or through its upper basin tributaries, which contribute with 30.2% of the total BOD load discharged into the Cauca River basin. Table 4.8 shows the municipalities having a WwTP and its current operation status.

Table 4.8 Municipalities of the Valle del Cauca Department having WwTP

Municipality Treatment level State Design

period

Design flow (l/s)

Design BOD load

(kg/day)

Treated Flow (L/s)a

Treated BOD load (kg/day) a

% BOD load

removal

a Ginebra Secondary Operating 73,3 1135 22 405 83 Guacari Secondary Operating 1996-2011 53,35 1215 73 460 85 La Unión Secondary Operating 1995-2010 60,6 1114 46 325 73 Roldanillo Secondary Operating 1995-2010 60 1441 44 361 80 Toro Secondary Operating 1996-2011 25,6 589 22 138 89 Yumbo b Primary built 1993 600 19440 Río Frio Secondary Operating 2006-2023 27 655 10 Ulloa c Secondary Built 2002-2022 4,47 203 Cerritob Secondary Built 2004-2024 90 2434 Tuluád Secondary Built 2002-2022 659 13457 Sources: Data collected during several visits made to the wastewater treatment systems in 2008. a Unique Information System http://www.sui.gov.co b The final collector that delivers wastewater to the plant has not been built yet. c Under start-up process. d Not delivered to CVC. Considering provisions in Agreement 014 of CVC of 1976, starting in 1990 all river basin municipalities had to have at least one secondary treatment for their wastewater and as seen in Table 4.8 , only 10 municipalities are actually complying with such standard. The rest of municipalities have a delay of over 18 years in the construction of their systems, which demonstrates that in spite of having the existing legislation, the municipalities are not following it. This has generated an increase in the organic matter discharged into the Cauca River.



4.2.4 Wastewater management of other municipalities Cauca department has deficiencies regarding the management of wastewater in general. This situation is the main cause of problems related to respiratory deficiencies, water body’s pollution, landscape deterioration and higher costs in the drinking water treatment (EMCALI and Universidad del Valle, 2006). Table 4.9 shows the removal information and investment proposal for the treatment of wastewater provided by the CRC Corporación Autónoma Regional del Cauca, for 2005. Table 4.9 Wastewater treatment status in the municipalities of Cauca located in the Cauca

River Basin – 2005

Municipality Sub-basin WwTP status

Urban population

2005 (inhabit)

WwTP coverage

(%)

Urban population

coverage by WwTP 2005

(inhabit)

BOD Load

(Kg/day)

BOD load

removal (%)

Caloto La Quebrada Operating (2001) 6455 90 5810 221 80 Cajibío Río Cauca Operating (2001) 3313 100 3313 126 80 Caldono Río Ovejas Operating(2001) 3494 90 3145 119 80 Corinto Río Palo Operating (2001) 16620 100 16620 632 80

Piendamó Río Piendamó To be defined 15091 95 14336 545 80 Jambaló Río Palo Operating (2001) 1971 0 0 80

Miranda Río Palo Design and construction 13247 95 12585 478 80

Morales Río Cauca Operating (2001) 4072 89 3624 138 80 Popayán Río Cauca Design 218350 91 198699 7551 80 Padilla Río Palo Operating (2001) 4480 90 4032 153 80

Río Palo Designed with

priority for construction

12000 0 0 80 Puerto Tejada Q. Zanjón

Oscuro To be defined 41791 87 36358 1382 80

Santander de Quilichao

Río Quinamayó Design 40895 87 35579 1352 80

Toribío Río Palo Operating (2001) 3908 0 0 80 Villa Rica La Quebrada Design 9092 90 8183 311 80

Source: CVC (2006) The river basin in the Cauca department receives high industrial wastewater contributions mainly from the paper and sugar cane industry (around 4,44 ton/day) which corresponds to 86,4% of the total industrial discharge to the river basin. However, after law Páez4 was implemented, around 65% of the new industries created use now dry production and the remaining 35% has implemented wastewater treatment plants as clean production technologies which has helped lowering the impact from the new industries on receiving waters to around 469 kg/day (which corresponds to around 9,1% of the total load discharged to the river).

4 The law Páez (law 218 of 1995) regulated the generation of economical incentives to create industries in the department of Cauca, at present there are an industrial complex in the south of this department.



4.2.5 Industry wastewater management In reference to the industrial sector, there are agreements and strategic alliances among the large enterprises (close to 10% of the total industries) that strengthened by the application of standards such as the ISO 14000 and cleaner production stimuli, have favourably impacted environmental quality. These industries have made significant investments for the improvement of processes, substitution of fuels and technological restructuring, which has represented important achievements in the improvement of water quality. Different to what occurs at municipality level, the formal industry has complied with Agreement No 014 of 1976 for pollution control by the construction of wastewater treatment plants and emission control systems. This has contributed for most industries to present most of their indicators within the individually allowed limits (CVC, 2004). Table 4.10 present the wastewater management plans and programs of some enterprises that attended the Monitoring Network Water Quality Seminar held in Popayan in July, 2004. However, it is necessary to consider that the information provided by the industry about load discharged into the water bodies is taken base don daily averages. Additionally, the monitoring frequency is low, the environmental authority monitors twice a year, during short periods of time and during labour days (does not include weekends). The effect of the variation according to the time of the day can be observed in Figure 4.10, taking two tributary rivers that have an impact on industrial discharges as example. During a monitoring session held between July 11-15, 2006, maximum contamination loads up to 60 ton/day were taken for the Guachal River and 17 ton/d in the Zanjon Oscuro Stream , during schedules in which the domestic activity is low (00:00 to 6:00 a.m.)

0

10

20

30

40

50

60

70

00:00 11

06:00 11

12:00 11

18:00 11

00:00 12

06:00 12

12:00 12

18:00 12

00:00 13

06:00 13

12:00 13

18:00 13

00:00 14

06:00 14

12:00 14

18:00 14

00:00 15

06:00 15

12:00 15

Time (hours)

BO

D L

oad

(ton

/day

)

Zanjón Oscuro

Río Guachal

July

Figure 4.10 Time variation of the BOD load in the Zanjón Oscuro and Guachal rivers

tributaries. Monitoring campaign held July 11-15, 2006. Source: EMCALI and Universidad del Valle (2006)



Table 4.10 Pollution control strategies for some industries located in the Upper Cauca River Basin

Department Industry Currently strategies of control Future strategies of control

Propal Plant I

WwTP with secondary treatment

Industrial growth in the sustainable frame

Reduction of water consumption Water, fibres and energy recovery Filtration of the wastewater influent Implementation of activated sludge –

enlargement of the WwTP

La Cabaña sugar mills



Enlargement of the WwTP Optimization of the wash off process in the

sugar cane plant

Papeles del Cauca industry

WwTP with secondary treatment Did not mention activity

Caloto industrial park stage 1, 2 and 3 Did not assist

Cauca

South park Did not assist

Smurfit Cartón de Colombia


Industrial growth in a sustainable frame

Did not mention activity

Propal Plant II



Reduction of water consumption

Cartones del Valle WwTP Fibres recovery plan from the effluent Reduction of the water consumption by

water reuse

Empaques Industriales Colombianos WwTP

Fibres recovery plan from the effluent Reduction of the water consumption by

water reuse

Central Tumaco sugar mills


Effluent of WwTP is used in irrigation of the sugar cane crops

They will continue with the reuse plan Reduction of water consumption

Maria Luisa sugar mills WwTP with secondary treatment Did not mention activity

Valle del Cauca

Sucromiles WwTP with secondary

treatment

Did not mention activity

Source: Industries participating in the industrial sector seminars held in Popayan on July 9, 2004, and in Cali on June 21, 2004. 4.2.6 Water quality objectives of the Cauca River Through CVC Resolution No. DG.O686 dated November 20, 2006, the Corporación Autónoma Regional del Valle del Cauca – CVC, established the quality objectives and proposed contamination reduction goals for the Cauca River Basin during 2007 – 2016, according to the Colombian Political Constitution (Articles 79, 89 and 95), Law 99 of 1993, Decree 3100 of 2003 partially modified by Decree 3440 of 2004, Resolution 1433 of 2004 modified by Resolution 2145 of 2005. The objectives proposal included historical data of monitoring activities held by CVC since 1993, which have been statistically analyzed every 5 years, and the results of the Cauca River water quality model in the phase III PMC Project.



The area with defined quality objectives corresponds to the Cauca River section and its influence basin located in the Geographic Valley, within the CVC jurisdiction area, in the Department of Valle del Cauca, with a length of 421 kms. This area was divided into three sections: Section I - Stations Before Timba until El Hormiguero Section II – Stations between El Hormiguero and Mediacanoa Section III – Stations between Mediacanoa and La Virginia Bridge

These objectives were defined for the dry season, with water flow equal or greater than 130 m3/s in the Juanchito Reference Station. Figure 4.12 shows the spatial variation of the DO and BOD concentrations of the Cauca River in two different scenarios (E22 and E27) and the base year (2005) selected by CVC within the framework of the PMC Project, for the years 2010 and 2015. Results of the modelling of these scenarios were used for the proposal of the Cauca River water quality objectives for 2011 – 2016.

0

1

2

3

4

5

6

7

0 50 100 150 200 250 300 350 400

BO

D (m

g/l)

E0 2005

E22 2010

E27 2015


Cali Urban area

0

1

2

3

4

5

6

7

8

0 50 100 150 200 250 300 350 400Abscisa (Km)

Dis

solv

ed O

xyge

n (m

g/l)

E0 2005

E22 2010

E27 2015


Cali Urban area

Figure 4.11 Variation in the BOD and DO concentrations in the Cauca River at the Base Scenarios for the Proposal Cauca River Water Quality Objectives Proposed by CVC. La

Balsa – Anacaro Section Source: CVC and Universidad del Valle (2007a) PMC – Cauca River Modelling Project – Results of the MIKE 11 Model Application



According to Resolution, the Hormiguero – Mediacanoa Section II (area of influence of the city of Cali) is expected to have levels of DO higher than 1.2 mg/L (see Figure 4.11). Goals for contamination load reduction for the different stakeholders involved in the CVC jurisdiction area are shown in Table 4.11 Table 4.11 Contaminating load reduction goals – Resolution 0686 of November 20, 2006 -

CVC Section By 2011 By 2016

Municipality of Cali

Wastewater flow entering the WwTP Cañaveralejo will increase from 3.35 m3/s to 6.47m3/s. Total BOD load produced 113.2 ton/day Effective removal: 38%

Removal of 80% of the contaminating load in 50% of the wastewater flow entering the WwTP Cañaveralejo. Total BOD load produced: 130.4 ton/day

Other municipalities of Valle del Cauca

department

Tulúa, Riofrío, El Cerrito, Pradera, Ulloa, Caicedonia, Buga, Yumbo, Bugalagrande, and Bolívar municipalities will implement their WwTP Total BOD load produced: 29.6 ton/day Effective removal: 80%.

Florida and Candelaria will remove 80% of the BOD load. Palmira will remove 80% of the contaminating load discharged into the Palmira River (removal of 56% of the total load). Jamundí will have removal above 64% Total BOD load produced by the two municipalities: 2.4 ton/day

Coffee Sector

5 ton/day decrease in the BOD load discharged in the basin through technological restructuring. Total BOD load produced: 32.4 ton/day Effective removal: 17%

Reduction of 10 ton/d of BOD load discharged in the basin through technological restructuring.

Industrial Sector

The industries will implement Cleaner Production practices and Environmental Management Plans in order to reduce discharged loads (Sugar Molasses Mills, Industria de Licores del Valle, Food Industry, Alcohol-Chemical Plants) with removal of BOD and SST greater than 80%.

The Acopi / Arroyohondo sector has made treatments to obtain BOD 5 removals of approximately 50%.

Source Adapted from CVC, 2006 Estimated 2006 investment costs to reach the Cauca River water quality objectives is approximately $747,500 millions (approximately US$ 317 million) 4.3 ANALYSIS 4.3.1 Wastewater pollution control in Colombia Since 1952 (Law 2 of 1952 – Forest Reserves), date in which the first standard related to natural resource protection was issued, many policy and standardization developments have occurred in Colombia. Resource management was characterized by its centralization back them. With the creation of the first regional environmental institutions, these roles started being decentralized. The model under which the Autonomous Corporations were created responded to the bio-geographic unit concept. However, this concepts lost strength as each of the departments wanted to have authority over their own natural resources and later,



even more, with the creation of urban environmental authorities in cities with more than 1 million inhabitants (Ley 99 de 1993). Fifty seven years after issuing the first standard related to pollution control, the impairment of water resources caused by wastewater discharges is increasing. Following are the possible causes for this: The institutional framework of water and sanitation sector that regulates the national territory, including the city of Cali, in which each institution has an area and a specific subject of intervention prevents the exchange and flow of information, duplicates efforts and resources and prevents the development of an integral water management. Additionally, the jurisdiction areas have been conceived based on political and administrative limits rather than at river basins level. In some occasions, it is not very clear the jurisdiction and responsibility of the institutions when managing the environmental problems in the city; hence problems of water pollution continue without solution. It is believed that the problem of pollution of water resources in Colombia more than a policy problem stems from the institutional. Although in the past years, it has been observed the development of new policies and

programs that aim at the implementation of measures to improve towards the sustainable development still the “end-of-the-pipe” approach is the most widely used when referring to integral management of water resources.

The CONPES policy documents present priority guidelines and actions directed

towards the proper planning and integrated management of the water resource. However, it is important that these evolve towards standardizations having key implementation strategies.

Strategies are poorly applied in the standardization, such as minimization and

prevention, cleaner production, and the efficient use and reuse of water. The normative for the control of pollution of the water resources, set decades ago and of

which an effective part is currently in use, have been designed based on a “corrective approach” and more precisely “the end-of-pipe approach", rather than a preventive and integral one. The current standards are directed to mitigate the impact of waste discharges on the receiving water bodies mainly through two complementary policies: a first one of control and a second one based on an economic resource known as the water pollution fee when discharging to water bodies which is not working as it was expected.

According to figures provided by the Vice-Ministry of Water and Basic Sanitation, in

Colombia 900 wastewater treatment plants have to be built in order to solve river pollution problems due to the fact that the actual coverage is only 9% (approximately 200 WwTP), but the capability is 32% (according to El Espectador journal, Bogotá, September25, 2008). In terms of available resources, it is expected to have a 50% coverage by 2010, with investments made with the available budget of 1,200,000,000 million pesos (US$ 628 million)



There are problems implementing tariffs that are affordable, and that include resources for coverage expansion, operation and maintenance of water/wastewater services. In addition, according to CONPES (2003) cited by Guio (2004), there is a lack of financial incentives in areas where the marginal cost is higher than the average one. In addition, since there has been a reduction of subsidies, it has been impossible to charge the water use and water pollution fee in the water bill. Regarding the water pollution fee, its implementation has been slow and started to be charged only to users that had any economic reward such as the industries. On the other hand, the implementation at house level has not been possible as far as today and diffuse pollution is not considered either. Therefore, livestock and agriculture activities have been indirectly favoured.

There is a tremendous lack of efficient management systems and presence of

insufficient information on water measurements to determine “who” contaminates and to which extent. In general to implement monitoring systems, to measure the contamination of soil and underground waters, to construct models of quality of water and to determine the contributions of polluting agents from the industries is a task that entails a great deal of technical, institutional and economical effort.

There is a weak capacity of enforcement and a low level of governance regarding water

resources. According to the National Development plan 2002-2006, the lack of control and coordination between institutions have produced incoherent disorganization in the judicial Colombian system. The problem can be defined as the continues uncertainty of citizens towards access, responsiveness, equity, efficiency and effectiveness of justice.

According to Guio (2004), there is not a defined water law in Colombia. There are

many laws and decrees that focus on different aspects of water management. Yet, these laws and decrees are modified several times and the relevance or priority of them can not be understood. In some cases it is not clear if a determined decree is still valid or not so the level of complexity in understanding these laws increases. Hence, the water legislation is very complex and causes that any attempt for an integrated management will be very difficult.

The regulation for the control of the pollution of the water resources is frequently

defined only based on the loads of BOD and TSS, being as well present contamination that is caused by other type of substances that also require an effective control.

The limitation in the availability of economical resources prevents the implementation

of programs and technologies conceived inside the framework of the sustainability principles and integral management.

Plans of action to mitigate and prevent contamination of water bodies are not planned

on a long term. Rather, such plans are proposed in a “short basis” to remediate the so thought “immediate problems”

There are no effective follow up and control mechanisms for the application of these

standards. If Decree 1594 of 1984 is taken as example, according to its issue data and



the deadlines for its execution, up to date, each municipality should have its wastewater treatment plant in full operation.

4.3.2 Pollution control for industrial wastewater In terms of industrial pollution control, standards do not adjust to the different characteristics of industrial wastewater. This is based on the removal of organic matter and solids. However, the chemical load is not included in the removal goals. Additionally, there are no studies that establish allowable limits for sanitary interest substances that consider wastewater characteristics and their impact of the receptor body, as well as the implicit limitation of its uses. The current standards for monitoring programs that include analysis frequency, sampling periods and evaluated parameters are flexible in terms of the industrial sector follow-up. 4.3.3 Pollution control in the agricultural sector As mentioned in the previous items, the demand of surface or ground water sources for direct agricultural use represents 48 % of the total municipal demand. Besides, it is the potential most important user of domestic wastewater. In consequence, this sector generates the greatest contaminating load received by the water resources. Decree 1594 of 1984 includes the pollution control standards for non-specific sources. However, there are no standardized gauging methods, nor methods validated in Colombia to avoid agricultural wastewater discharges. In this sense, limitations are found due to the lack of studies and research, as well as the lack of application of innovative technologies for the control of pollution generated by this productive sector. 4.3.4 Wastewater pollution control in the Upper Cauca River Basin and the city of

Cali The Cauca River contamination problems have affected not only the city of Cali, but also the industrial sectors, small municipalities and the agricultural sector of the different river basin stakeholders by decreasing the acceptable quality water supply for different uses. According to the MAVDT, the Cauca River is among the 5 basins with the highest contamination level. Therefore, corrective actions are a priority. In the Upper Cauca River Basin, in the Salvajina – La Virginia section, the wastewater pollution control is responsibility of the environmental authorities: CVC, CRC, CARDER, CRQ, DAGMA in the city of Cali and the MAVDT with the National Parks Direction. In spite of the presence of several government entities, the water quality of the Cauca River continues decreasing. There is a clear lack of articulation among basin actions, due to its fragmentation, and the level of complexity required for the articulation of the technical, financial, economic



articulation, as well as the political interests and priorities of the different environmental authorities present in the area. So far, the approach for pollution control continues being “end of the pipe” solutions. Only 7 of the 34 municipalities of Valle del Cauca have treatment plants in operation, which only treat 16% of the organic load discharges (total load is 213 ton/day). According to CVC, increasing to 1.2 mg/L DO by 2015, through the construction of treatment plants at the main urban centres of Valle del Cauca, including other productive sectors (coffee growers, paper and sugar industries) would have an approximate cost of US$ 394 million dollars (Year 2008), while the available budget for Colombia in terms of wastewater treatment investments by 2010 is US$ 600 millions, exceeding the nation’s budget by 70%. If we consider that the main domestic origin contaminant load corresponds to the city of Cali’s discharges, the chronogram proposed by EMCALI in the PSMV for the next 10 years (2007 – 2016) does not include the construction of the WwTP secondary treatment. By the contrary, sewage infrastructure work would be made to conduct and increase the affluent flow to WwTP. The approximate cost of these investments would be US$ 195 million dollars (Year 2008) Likewise, although it is not recognized as part of wastewater management problems, the agro-industrial sector makes a significant contribution to the problem, which added to the standardization flexibility, represents a lack of control by the environmental authorities in terms of water uses and its final destination. Due to this, it is necessary to purpose and implement new strategies in order to control pollution at a long term and having integrated urban water management, which includes the different basin stakeholders with alternatives for the minimization and prevention starting at the contamination source.

Chapter 5. Paradigm shift in water management in urban areas


5 PARADIGM SHIFT IN WATER MANAGEMENT IN URBAN AREAS 5.1 CONCEPTS 5.1.1 Water quality requirements Water bodies can be fully characterised by the three major components: hydrology, physic-chemistry, and biology. Water quality has evolved over the past century with the expansion of water use requirements and the ability to measure and interpret water characteristics. Description of the water quality can be achieved either through quantitative measurements, such as physicochemical determinations (in the water, particulate material, or biological tissues) and biochemical/biological tests (BOD measurement, toxicity tests, etc.), or through emiquantitative and qualitative descriptions such as biotic indices, visual aspects, species inventories, odour, etc. Human influences have had a direct effect on the hydrologic cycle by altering the land in ways that have changed its physical, chemical, and biological characteristics (Lundqvist, 1998; Hem, 1985; Meybeck and Helmer, 1989 cited by Peters and Meybeck, 2000). In addition, these human activities alter water quality not only by changing hydrologic pathways, but by the addition of substances and wastes to the landscape (Peters and Meybeck, 2000). In general, pollutants can be released into the environment as gases, dissolved substances or in the particulate form. Ultimately pollutants reach the aquatic environment through a variety of pathways, including the atmosphere and the soil. Pollution may result from atmospheric sources, point sources or diffuse sources. Spatial and temporal variation in water quality is one of the main features of different types of water bodies, and is largely determined by the hydrodynamic characteristics of the water body. Water quality varies in all three dimensions which are further modified by flow direction, discharge and time. Water quality criteria are developed by scientists and provide basic scientific information about the effects of water pollutants on a specific water use. Many water quality criteria set a maximum level for the concentration of a substance in a particular medium which will not be harmful when the specific medium is used continuously for a single, specific purpose. For some other water quality are set at the minimum acceptable concentration to ensure the maintenance of biological functions. Criteria may also be developed in relation to the functioning of aquatic ecosystems in general, the protection and maintenance of these water uses usually impose different requirements on water quality and, therefore, the associated water quality criteria are often different for each use. Water quality objectives aim at supporting and protecting designated uses of freshwater, its use for drinking water supply, livestock watering, irrigation, fisheries, recreation or other purposes, while supporting and maintaining aquatic life and/or the functioning of aquatic



ecosystems. Human requirements for water also directly affect hydrologic pathways by providing water of a specified quality for different activities to sustain human existence. Water quality criteria often serve as a baseline for establishing water quality objectives in conjunction with information on water uses and site-specific factors (Table 5.1). Water quality objectives are being developed in many countries by water authorities in co-operation with other relevant institutions in order to set threshold values for water quality that should be maintained or achieved within a certain time period. Water quality objectives provide the basis for pollution control regulations and for carrying out specific measures for the prevention, control or reduction of water pollution and other adverse impacts on aquatic ecosystems.

Table 5.1 Definitions related to water quality and pollution control Term Definition

Water quality criterion (synonym: water quality guideline)

Numerical concentration or narrative statement recommended to support and maintain a designated water use

Water quality objective (synonyms: water quality goal or target)

A numerical concentration or narrative statement which has been established to support and to protect the designated uses of water at a specific site, river basin or part(s) thereof

Water quality Standard An objective that is recognised in enforceable environmental control laws or regulations of a level of Government

Precautionary principle

The principle, by virtue of which action to avoid the potential adverse impact of the release of hazardous substances shall not be postponed on the ground that scientific research has not fully proved a causal link between those substances, on the one hand, and the potential adverse impact, on the other

Source: Helmer and Hespanhol, 1997 5.1.2 Sustainability The sustainability concept has become a mandatory benchmark for any discussion related to natural resource planning and management. Searching for sustainable solutions has made water supply and sanitation sector stakeholders understand that there are not only technical problems, but that these have to be faced with an integrated vision. In general, a sustainable system is the one having the capability to perform its functions at an acceptable level, and provides the expected benefits during the entire planned life, using the least resources possible, even in terms of environmental resources (Duque and Restrepo,1998). Sustainability is not a final status; it is something that must be built and supported daily in order to detect the danger warnings with enough anticipation as to solve the problems. (Duque and Restrepo, 1998) 5.1.3 Integrated Water Resource Management The Integrated Water Resource Management IWRM consists of a process that promotes the coordinated management and development of water, soil and related resources, in order to maximize the social and economic wellbeing resulting in an equal manner, without



compromising the sustainability of vital ecosystems. However the IWRM concept has been widely debated and presently does not have an exact definition. Therefore, regional and national institutions must develop their own IWRM practices, using the cooperation frameworks that arise globally and regionally (GWP and SAMTAC, 2000). Current urban water systems harvest large volumes of water from remote catchments and groundwater sources, deliver drinking quality water to all urban uses and subsequently collect generated wastewater. Large volumes of stormwater are also generated within urban areas due to the increased imperviousness of urban catchments. The majority of this stormwater flows out of the urban area, with little management of its quality and even less of it being used. As a result, the adverse impact of conventional urban water management on the water balance of these areas is substantial (Mitchell et al., 2001). Integrated Urban Water Management recognises that the whole urban region, down to the site scale, needs to be considered, as urban water systems are complex and inter-related. Changes to a system will have downstream or upstream impacts that will affect cost, sustainability or opportunities. Therefore, proposed changes to a particular aspect of the urban water system must include a comprehensive view of the other items and consider the influence on them. The principles of Integrated Urban Water Management can be summarised as: Consider all parts of the water cycle, natural and constructed, surface and sub-surface,

recognising them as an integrated system. Consider all requirements for water, both anthropogenic and ecological Consider the local context, accounting for environmental, social, cultural and economic

perspectives Include all stakeholders in the process Strive for sustainability, balancing environmental, social and economic needs in the

short, medium and long term These principles have emerged in recent years, drawing on the view that sub-optimal outcomes have been produced from the traditional compartmentalisation of water supply, sewerage and stormwater services. This compartmentalisation has been both physical, in terms of infrastructure, and institutional in terms of responsibility for service provision, operation and maintenance, which, over time, has led to philosophical compartmentalisation and shaped perceptions of system boundaries (Coombes and Kuczera, 2002). The sue of the ‘integration’ word in the IUWM acronym refers to the physical system and the many players who create, maintain, and are served by urban water systems. 5.1.4 Urban water The urban water cycle begins with water extracted from surface water, streams and aquifers, usually stored in reservoirs and then processed to potable quality before delivery through an extensive pipe system to residential, commercial and industrial developments. The treated water is also used for recreational purposes including irrigation of parks and



gardens. Some of this water is then used to transport wastes through a network of sewers to treatment plants which discharge effluent into receiving waters such as rivers, lakes and oceans. Rainfall falling on the consumer’s allotment contributes to the urban catchment’s stormwater that is collected by an extensive drainage system for disposal into receiving waters. Figure 5.1 presents a diagram of the cycle described. Although the treatment technologies for water and wastewater have improved, approaches to supply of water and wastewater and stormwater disposal have remained largely unchanged over the last 120 years. The paradigm for urban water cycle management has compartmentalised the cycle into the provision of water supply, wastewater and stormwater services.

Figure 5.1 Urban water cycle. 5.1.5 Cleaner Production According to UNEP, the United Nations Environmental Program, Cleaner Production is the “continuous application of a preventive environmental strategy integrated to the processes, products and services to increase total efficiency and reduce human and environmental risks”. The CP idea goes beyond the traditional practice of adequately treating and disposing waste resulting from productive processes. Its essence is to have more economic technologies and processes in the use of natural resources, which require of less raw material, water, energy and toxic substances in a more efficient manner, resulting in less waste and lower operation costs.



Although the Cleaner Production concept has a different meaning under the urban water context, its essential elements are: (Siebel and Gijzen, 2002): Principle 1: Use a minimum input of resources per unit or product Principle 2: Do not use input material of a higher quality than strictly necessary Principle 3: Do not mix different waste flows Principle 4: Evaluate other functions of by-products before considering treatment and

disposal The application of the concept of Cleaner Production in water management displayed in introducing this concept can be developed through the development of the so called 3-Step Strategic Approach for urban water management. This approach strongly focuses on sewage management, but also considers water supply, nutrient uses and other material flows associated with the urban water cycle. The three steps include: 1) prevention, 2) treatment for reuse, and 3) planned discharge with stimulation of self-purification capacity. The steps should be implemented in chronological order, and possible interventions under each step should be fully exhausted before moving on to the next step. This strategic approach is summarised in the Figure 5.2.

Step 1 Prevention & Minimisation

The key question is ‘to use or not use?’ - Reduce water use - Water saving technologies

(in industry and household) - Reuse grey water - Ban undesirable compounds

(e.g. P-detergents, toxics) - Apply low water use or dry

sanitation - Apply rainwater harvesting

Step 2 Treatment for reuse

- Convert waste to something useful for reuse (e.g. biogas, fertiliser, protein).

- Select treatment process that makes best use of possible side products

- Optimise effluent reuse

Step 3 Stimulate natural self purification

After exhausting options under step 1 and 2, only disposal remains. Nevertheless, we can help’ the natural resource boosts its self purification capacity

Water Resource

Figure 5.2 Schematic representation of the 3-Step Strategic Approach to wastewater management

Source: Nhapi and Gijzen, 2005 Step 1: Pollution prevention or waste minimisation: The basic principle is that interventions should start by controlling consumption. The same applies to the use of high quality drinking water; e.g. is it wise to use 50 to 80 litres of high quality drinking water to transport daily 1 – 1.5 kg of human waste to a water treatment facility or, as is often the case, to a water resource. Reduction in wastewater generation is therefore necessary in view of the importance of conserving resources, investments and energy. This can be achieved via reduction of domestic water consumption, which will reduce sewage volume and treatment costs. On the far end of the scale we find dry sanitation, but significant reductions can also be achieved via demand management and water saving technologies in the



household (water saving flush toilets, water efficient shower caps and taps, efficient dishwashers, laundry machines etc.). In addition demand management schemes should be aimed at educating families in efficient water use. Waste minimisation involves not only technology, but also planning, good housekeeping, and implementation of environmentally sound management practices (cleaner production). It also involves a special attitude of the users (education, demand management). The ‘polluter pays’ concept and discharge limitations are some of the instruments used to control user practices. Industries can also be compelled by legislation to strictly treat or pre-treat and reuse wastewater within their properties, wherever possible, and thus limit discharges to public sewers and streams. The successful implementation of a wide range of options under Step 1 will lead to smaller volumes of more concentrated wastewater reaching wastewater treatment facilities. This makes effective wastewater treatment aimed at resource recovery possible. Step 2: Treat for reuse: Municipal wastewater contains valuable resources and therefore it is irrational to treat it the conventional way with subsequent river discharge. Its components of water, organic matter (energy), and nutrients should be reused. Systems such as greywater separation offer opportunities for direct reuse of wastewater at the point of generation for purposes such as car washing, toilet flushing, and on-plot irrigation. In some cases, urine could also be separated and reused directly (Larsen and Gujer, 1996 as cited in Nhapi and Gijzen, 2005). In this step, technologies are selected aimed at treating in the direction of reuse. Anaerobic treatment of the more concentrated wastewater will generate biogas as a form of renewable energy. Post-treatment of the effluent can be combined with effective recovery of nutrients via aquatic plants (e.g., duckweed) and/or by irrigation of crops in agriculture. A main limitation of these reuse practices is that sewage is generally not (sufficiently) treated before reuse, which introduces public health risks. The combination of anaerobic treatment, for energy recovery, and duckweed-based lagoons for pathogen removal and nutrient recovery was proposed as an example of possible re-use strategies (Gijzen and Veenstra, 2000; El Shafai et al., 2003 as cited in Nhapi and Gijzen, 2005 ). The focus on duckweed as a key step in waste recycling is due to the fact that it forms the central unit of a recycling engine, driven by photosynthesis and therefore the process is energy efficient, cost effective and applicable under a wide variety of rural and urban conditions. Step 3: Dispose and stimulate natural self-purification: All options under Step 1 and Step 2 should be exhausted before resorting to Step 3. In some cases the application of above steps might still leave some residual wastes and effluents and the last option remaining is discharge, usually into surface waters (river, lake, coastal sea). The conventional approach is to connect the effluent pipe to the nearest water resource via the shortest route. We seem, therefore, to rely fully on the self purification capacities of receiving water bodies. In reality, however, often this capacity is exceeded substantially, rendering water bodies anaerobic, eutrophic or with high concentrations of toxic compounds. Under the 3-Step Strategic Approach proposed here, we suggest to consider options to boost the natural purification capacity of receiving water bodies. This could for instance be achieved by allowing rivers to flow outside their often times artificial embankments.



5.1.6 Multiple uses of water Multiple uses of water are a concept derivate from Integrated Water Resources Management. In essence, a multiple use approach involves 1) assessing the range of water needs in collaboration with end users, 2) examining the water sources available from rainwater to wastewater to piped systems, and 3) matching water supplies to needs based on the quantity, quality and reliability required for various purposes. Three crucial aspects of a multiple use approach that are neglected in traditional approaches to water supply are: participation of local communities, identification of all water needs, and consideration of the different water sources available. While this may require more time and effort than rolling out a blanket programme, the end result is more economically efficient, social equitable and environmentally sustainable. The current single use perspective which dominates thinking on water development and service provision has led to domestic water supply schemes that ban the use of water for production or that supply too little water for any but the most basic domestic needs and to irrigation schemes that ignore the need for domestic or household level production activities. By failing to address people’s real needs, this top-down, technocratic approach dis-empowers them and leaves them responsible for systems that only partially meet their requirements (IWMI et al., 2006). 5.2 PARADIGM SHIFT FOR THE CITY OF TOMORROW The paradigm shift represents a change in a set of scientific accomplishments that are “universally acknowledged”, which during a certain time provided problem and solution models for the community. A change in paradigm generally implies a deep change of mentality regarding the time and values that form a specific vision of the reality, where the variable is the speed and depth of the change. Knowledge and technological advance have generated new proposals for water resource management in order to respond to environmental problems currently encountered. This progress promotes overturning the previous planning and water management paradigm to implement one in which human wellbeing and development is combined in a balanced manner with the environment. The conventional water cycle requires a re-design that includes actual inefficiencies such as the use of high quality drinking water in large amounts for domestic use, human faeces transportation, loss of chemical substances, among others. Even though the systems used 100 years ago faced the same inefficiencies, presently rapid population growth and higher water demand per capita, as well as higher industrial consumption and pollution load have caused these systems to not be able to naturally compensate the impacts, resulting in severe ecological damages (UNESCO-IHE and European Commission, 2007). The approach towards Urban Water Management (UWM) of the city of tomorrow will be based on sustainability in all its depth. Table 5.2 compares various aspects of water management in the city of today with that in the city of tomorrow and where it should be oriented towards the paradigm shift.



Table 5.2 Comparison of water management of the city of today and that in the city of tomorrow

Aspect City of today City of tomorrow UWM organisation Organisational structure

Separate entities for different types of water, Covering entire urban area

One entity for ‘water’ covering entire urban area City subdivided in water management units (WMU) with high level of responsibility Water is a tradable good between units

Units Depending on preference of water entities

Determined by possibilities to manage water within a unit

Philosophy Various types of water have no relationship

Various types of water are part of the same cycle and serve various purposes at different times

Drinking water Quality One quality for all uses One quality for drinking, a second quality for other uses Distribution Underground piping system,

vendors Drinking water through shops, second quality through piping system

Origin From wherever available From nearby Wastewater Quality Any quality wastewater is

accepted Only ‘clean’ wastewater is accepted, dischargers responsible for quality of wastewater submitted

Collection Collection from domestic and industrial origin to point of discharge or (central) treatment

Collection of ‘clean’ wastewater within the WMU to point of further processing Specific waste flows kept separate

Treatment Predominantly of the activated sludge type

Further processing determined by the reuse/recovery options and the specific use of the water within the WMU Indirect reuse is objective

Discharge Into nearest surface water Depending on possibilities within WMU, e.g.: irrigation, groundwater recharge, surface water discharge

Rainwater Approach Removal as quick as possible so

as not to have flooding problems Make best possible use of this resource

Processing Removal into sewer Collection, temporary storage, followed by some type of treatment

Usage None Various options, e.g.: street cleaning, green areas, ground water recharge, or drinking/process water

Source: Siebel and Gijzen, 2002 5.3 SOME STRATEGIES FOR POLLUTION CONTROL IN THE URBAN WATER CYCLE IN THE RIVER BASIN CONTEXT In the frame IWRM promotes the use of mixtures of ecological and infrastructure technologies; and non-structural tools such as education, pricing incentives, regulations and restriction regimes. The structural tools are shown more in detail under item 5.5. Figure 5.3 shows a scheme of components, their relation to each other, and the level in which each one is presented. These parts combine in an environmental, socio-economic and cultural context which becomes specific to the area in which the water resource management or planning is applied. These components are: housing, industry, supply system, collection and transportation of wastewater, solid waste management, and water basin (Universidad del Valle et al., 2005).



Figure 5.3 Integrated water management at core settlements Source: Universidad del Valle et al., 2005

5.3.1 Household Average water use ranges between 200 and 300 litres per day per person in most of the European countries and 575 litres per person per day in the United States. On the other hand, average water use in countries such as Mozambique is less than 10 litres per day per person. In the United Kingdom, an average of more than 50 litres of water per day are used to flush the toilette, representing more than 10 times the total amount of water available for persons lacking access to an improved water source in most of the rural areas of the Sub-Saharian Africa, (FAO 2006 as cited in UNDP, 2006). Efficient water use is proposed as an instrument that promotes sustainable use and management of water resources. It is quite often accepted that the objectives of “sustainability” and “efficiency” in the use of natural resources differ substantially between them; moreover, in some cases, these targets are found in competition against each other (Bromley, 1990 as cited in Bithas, 2008). The most important goal for this new paradigm is to reintegrate the water used and maintaining an ecological balance and environmental health. As to water use, efforts to reach the productive use of water have to be re-focused. In this sense, two approaches are required: 1) increasing the efficiency in satisfying real needs, and 2) improving water distribution efficiency according to its different uses (Gleick, 2000). The efficient use actions have been supported by technological development, such as the appearance in the market of low consumption devices and strategies such as grey water recirculation and rain water as presented in Figure 5.4.

Environmental Conditions Cleaner Production

Freshwater

Available water

Groundwater

Wastewater Solid waste

Treatment

Environmental Services Social-Economic Cultural Context

Illegal Slum

Dwellings Industry

Natural ecosystem

Urban Drainage

River basin

Supply



Grey water use Rain water uses

Figure 5.4 Efficient water use in the household Low Consumption Devices At the household level, it is possible to perform resource conservation with low consumption technologies in taps, toilettes, and washing machines. Some of these technologies may be adapted to existing old equipment (aerators, tank discharge interrupter switches, automatic flow reducers, anti-return valves, etc.). Use grey water All household wastewater, except toilet waste, is called greywater. This includes water from showering, bathing, and washing dishes and clothes. The amount of greywater varies enormously between households. Consumption in poor areas can be as low as 15-20 litres per person per day, and in rich areas people may generate more than ten times as much. In ecological sanitation, grey water is source separated from toilet systems, allowing for simpler treatment systems than conventional sewage treatment plants. (Ridderstolpe, 2004. The cumulative flow balance between the grey water generated and toilet flushing requirements shows a natural affinity at about 30% of the total water use. However, the dynamics of the situation are not so ideal. Grey water is produced at a time slightly offset from toilet flushing and generated over short time periods, whereas toilet flushing takes place more consistently through the day. This generally results in a deficit in water during the afternoon and late evening as depicted in Figure 5.5. This may be rectified by buffering using appropriately sized storage tanks, but this substantially increases the overall system size. Detailed examination of the benefits of storage reveals that 1 m3 tank is suitable for a wide range of occupancy scales (Dixon et al., 2000 as cited in Jefferson et al., 2000 ). Increasing storage capacity above this provides only marginal increases in water savings and increases problems associated with grey water degradation and disinfection reliability (Jefferson et al., 2000).



Figure 5.5 Typical grey water production and toilet flushing requirements in a college

Source: Surendran and Wheatley, 1998 as cited in Jeferson et al., 1999 Rainwater Use Rain water is a component of the hydrologic cycle that feeds the surface, subsurface and ground water runoff (see Box 5.1).

Box 5.1 Grey water and rain water use In an individual or combined manner, they promote drinking water conservation because activities such as garden watering, household housekeeping and laundering can be carried out with this type of system. In a pilot study carried out in Southern Brazil it was found that the drinking water saving with a rain water system was between 33,8% and 36,6 %, and with a grey water system it was between 25% and 30,4 %.

Source: Ghisi and Mengotti de Oliveira, 2007 The rain water capture systems intercept the fluid before continuing its natural cycle in order to use it in multiple ways. This type of system is characterised by the collection, concentration and storage of rain water into natural and artificial surfaces as the case the Box 5.2. (Visscher and Sánchez, 1994).

Box 5.2 Kogarah Town Square, Sydney Australia Case The project is using best practice rainwater and stormwater harvesting, as well as stormwater discharge quality and flow management, thereby reducing pollutant loads entering the Cooks River and Botany Bay and helping to improve and maintain water quality in the local area. Rainwater is used for toilet flushing, car washing and a water feature, while stormwater is used for irrigation of open space within the site.

Water conservation measures featured in the development include water efficient toilets, showerheads and appliances and flow restrictors and aerating taps. Total water cycle and contaminant flux benefits: - Reduced potable water use by 42% through a combination

of water efficiency, rainwater and stormwater use. - Reduced volume of rainwater and stormwater leaving the

site by 85%. - Reduced volume of wastewater leaving the site by 4500

kilolitres. - Reduced concentration and load of stormwater

contaminants leaving the site. Source: Kogarah Town Square, 2006



Dry sanitation Dry sanitation is a modern adaptation of the old practice of human faeces management without the use of water, and therefore, without drainage. This means that: 1) toilets and urinals do not require water for their operation; 2) faeces are treated in the generation site; and 3) the production of a safe fertilizer. Its benefits include saving a large amount of water, reducing water pollution, reducing waste, decreasing pathogen viability and retaining in one place the nutrients that may later be applied to agricultural crops (Córdova, 2001). Urine Deviation The main difference between a urine deviation system and other sanitation systems is that the urine deviation system has two exits and two collection systems: one for urine and one for faeces, in order to maintain separate waste fractions. Urine deviation toilets can be discharged with or without water. In this context, better sanitation and recycling of nutrients are the factors that generate urine deviation. Due to the fact that urine deviation requires a different infrastructure than the conventional technologies, it is easier to introduce it in situations where this infrastructure is not available (Kvarnströn et al., 2006). It could be less expensive to reach the load decrease in the receptor bodies through the urine deviation instead of the construction of wastewater treatment plants or the upgrading/expansion of an existing treatment plant (Ridderstolpe, 2004) 5.3.2 Industry Industrial water is mainly used in processes such as heat transfer, energy generation, process application and housekeeping. In all economic activities, the water demands depend on two factors: 1) what is being produced and 2) the production efficiency. Therefore, the total use of industrial water depends on a combination of assets and services demanded by society and the processes selected to produce these assets and services. In the 30s, the production of one ton of steel consumed between 60 and 100 tons of water. By the end of the 90s, the same amount of steel was produced with 6 tons of water. However, the production of one ton of aluminium, which may be a substitute of steel in some industrial applications, only requires 1,5 tons of water (Gleick, 1998 as cited in Gleick, 2000). Box 5.3 shows an example of the ecological process of coffee in Colombia. The substitution of aluminium for steel which has been happening for many years in the automobile industry, for other reasons, can also reduce water requirements. In 1965 Japan used approximately 48,000 cubic metres of water to produce one million dollars in industrial products. By 1989, this amount had decreased to 13,000 cubic metres, meaning three times more industrial water efficiency (Postel, 1997 as cited in Gleick, 2000). Something similar occurred in California, where the total use of industrial water decreased by 30% between 1980 and 1990, without any kind of formal or intentional efforts, simply due to natural economic and technological changes that occurred during in that decade.



Box 5.3 Ecological process of coffee in Colombia (BECOLSUB) The traditional coffee production process uses approximately 40 L/kg of dry coffee: (12,5% in the pulp removal, 37,5% in the washing and transportation, and 50% in pulp transportation. A total of 46 million m3/year of water would be required for the production of a ton of coffee. At BECOLSUB, water is not required to remove the pulp. This is a dry process in which the beans are transported in cascade hoppers, by gravity. Equipment operating with centrifugal force is used to remove the mucilage or slime that covers the coffee. This is done to wash and clean the beans. This process only requires of 3 L/kg of dry coffee. Coffee sub-products, such as the pulp, are not transported by water, but through an endless screw, saving 20 L/kg of dry coffee. The pulp and mucilage are used as food for earthworms or as compost fertilizer. Wastewater is treated by anaerobic systems and the effluent is used to irrigate earthworm cultivation beds.

Source: Roa et al., 1999

At industrial levels it is important to implement cleaner production concepts in the productive processes, as well as in the infrastructure of sanitation services as such. Efficient water use is obtained as a result of several strategies, such as technological restructuring, process optimisation, recycling and water re-circulation, among others. Future actions shall aim to reach zero discharges as the only possibility of decreasing industrial contaminant discharges to the drainage in order to save water and operate the treatment plants (Milán, 2002). 5.3.3 Water supply system Two of the main problems currently encountered are the access to good quality sources and the low yield of the water distribution systems. In Colombia, during the period 2003-2005, water losses were at a level of 39% for systems having more than 400000 users. However, in systems ranging from 80000 to 400000 users, this amount was approximately 52%. Systems with 25000 to 80000 users have shown an increase of between 47% and 53% in the loss of water, while those with systems ranging between 2500 and 25000 users and have shown losses of 65% to 53%, (SSPD, 2006 as cited in Sánchez, 2008). In general terms this trend demonstrating higher water losses continues. Micro-measurement levels range between 77% for the small systems and 99% for the systems having more than 400000 users (Sanchez, 2008).



It is also important to note that a smaller consumption of water per capita reduces the flow and improves the efficiency of water treatment systems. Among the strategies to reduce this consumption (Vela et al., 1994; Sanchez, 2008) are: 1) information and education campaigns, 2) users persuasion policies to regulate and reduce consumption, 3) modification of the supply facilities and connections, 4) upgrade the strategies applicable to the sectors, 5) control pressures through pressure reduction valves or regulating valves and economic instruments (tariffs, financial incentives, etc.). Alternative sources of supply Figure 5.6 offers a revealing perspective on source control at the allotment scale. It shows the boundaries of the sub-systems responsible for water supply, stormwater and wastewater. Interestingly, all three sub-systems intersect at the allotment. In such a case implementation of source control solutions may require the involvement of two or more sectors of the water industry with different perspectives and priorities. The prospect for missed opportunities is apparent (Coombes and Kuczera, 2002). As previously shown, a local supply source is the recollection of stormwater in the household or industry, but when considering the human settlement subsystem, where other urban aspects such as roads and public space intervene, these waters may be stored and become an alternate water supply source. This would help in two senses: minimizing surface water demand and decreasing rainfall water disposal, both in quantity and quality.

Figure 5.6 Schematic of urban water cycle depicting sub-system spheres of influences

Source: Coombes and Kuczera, 2002

The main problem with the reliance on urban stormwater as the sole water source is the reliability of supply through extended dry periods. As a result, the best approach to stormwater utilisation can be in conjunction with other water resources such as currently developed potable water supplies and wastewater, to overcome need for large carryover storage.



Box 5.4 Kreuzberg Case (Germany ) The rainwater system has a total storage capacity of 240 m³ in two cisterns. This is equivalent to 40 mm or 6,7% of the annual precipitation. The system collects primarily “first flush” stormwater, the water that is the most highly polluted. The capture of pollutants and nutrients provides an increased ecological benefit. The collected rainwater is treated in a modified constructed wetland. The rainwater is used to flush toilets and for irrigation. 72% of water used in the community for irrigation and toilette flushing is rainwater provided by the stormwater detention system, only 38% is from the public drinking water supplier.

Source: Centgraf and Schmidt, 2005

Supply Basin and Distribution Network Public service providers have traditionally been concerned about loss controls base don the distribution network and have ignored other supply system aspects, with an integrated vision of the water capture at the basin, until the receptor body, once the water has been used. Efficient water management of the human consumption water supply has positive impact over the production of wastewaters due to the fact that water flow decreases while the contamination concentrations increase. Following are the possible actions required for an efficient waster supply system: (Vela et al., 1994; Sanchez, 2008): Information and education campaigns. Users’ Persuasion policies to regulate and reduce consumption Modification of water supply connections and installations. Prioritisation of applicable sector strategies (characterisation and estimate of leak

location strategies efficiency and selection of strategies to reduce loss volumes and strategies optimisation).

Pressure control through the use of valves - At economic level: Modification of tariffs, introducing low consumption bonus. - Introduction of a progressive tariff, structured by consumption blocks. - Inclusion of a season tariff to promote lower consumption during the dry season. - Financial incentives to invest in previous facilities’ improvements. Economic

penalties for inefficient use of facilities and devices. Real Time Control Systems (RTC) From the technical point of view, real time control is the information processing system in charge of responding to entrance stimuli generated externally in a finite and specific period of time that must be adapted to the dynamics of the controlled system. A real time control system has the following characteristics: Time: Time management and control. The correct execution considers not only the logic

but also the time in which the results are generated. Work must be assigned and completed before its deadline.

Reliability: Predictability, failure tolerance and safety.



Environment: The environmental dynamic characteristics change with time. The system shall control and/or react to the different environmental aspects (Universidad del Valle, 2008)

A RTC system generally performs the following functions: Collects information about the current state of the sewer network Compares the current state of the sewer network with the desired state of the sewer

network Determines the settings for the control facilities that will bring the sewer network

(closer) to the desired state Implements the settings into actions of the final control elements (e.g., gates, pumps,

inflatable dams) 5.3.4 Drainage of rainwater The urbanisation of a basin modifies its hydrological response in terms of a specific amount of rainfall, resulting in the alteration of the natural drainage networks (collector construction and channels that increase the downstream flow rate) and an increase of impermeable surface areas. All this, with the objective of having more efficient and rapid drainage of the urban area. This affects the basin’s hydrology, especially in areas located downstream. Upstream urbanisation modifies the hydrogram in such a way that the runoff and maximum water flow increase. Likewise, time elapsed between the beginning of the runoff caused by the rainfall and the maximum water flow is less, decreasing the concentration time. This means the downstream areas are more frequently affected by water flows that may cause problems such as floods, whose importance will depend on the characteristics of the slopes. Stormwater pollution is other problem in urban areas. The loadings and concentrations of suspended solids, nutrients and other contaminants are much higher in urban stormwater runoff than in runoff from unimpaired and rural areas (Sartor and Boyd, 1972 as cited in Vaze et al., 2002). There have been numerous studies on pollutant washoff (Duncan, 1995 as cited in Vaze et al., 2002). Although the pollutant availability on the catchment surface is an important variable used in most existing washoff models, there have been few studies (Barrett, Malina; Charbeneau and Ward, 1995; Deletic, Maksimovic, Loughreit and Butler, 1998 as cited in Vaze et al., 2002) on pollutant buildup since the detailed experimental pollutant accumulation study of Sartor and Boyd in (1972). The only conclusion that can be drawn from these limited studies is that surface pollutant load increases with antecedent dry period (Vaze et al., 2002). Sustainable urban drainage systems (SUDS) emerge in response to this situation. Their principle is to try to reproduce the natural water cycle before urbanisation or human actions take place. Its objective is to minimize the impact of urban development in terms of run-off water quality and quantity (in its source, during its transportation and its destination), as



well as upgrading the landscape integration and the social and environmental value of the action (Perales and Doménech, 2008) (Figure 5.7).

Figure 5.7 Conventional urban drainage vs. SUDS Some SUDS options are: green roofs, permeable surfaces, filtration beds, infiltration wells, infiltration trenches, infiltration tanks, retention areas and wetlands. Options are programmed to work in series, associated to one another, with the green zones and, even with the existing drainage infrastructures, becoming a rain water management system. In essence, the objective is to optimise the system, increasing the concentration times and minimizing the risks or flooding possibilities in the cities. These systems offer better compatibility and harmony in urban development and water and ecology processes, emphasizing the importance of water filtration, retention, treatment and reuse in rain water sources (Figure 5.8) Among the sustainable drainage system alternatives are: Green covers; permeable surfaces; filter strips; wells and infiltration ditches; infiltration deposits; detention deposits; retention reservoirs and wetlands. 5.3.5 Treatment and reuse of wastewater First of all, it is important to consider that before implementing wastewater treatment systems it is mandatory to collect the domiciliary effluents and take them to the plant site. Therefore, the existence of a sewage system is a previous requirement. This means that the investments have to be made in order to build the collection and the conduction facilities before the treatment plant is built. (López and Jordán, 2000)



Park-Detention deposit Infiltration Deposit

Green ditch Green Covers

Figure 5.8 SUDS Options Wastewater Management Decentralised Systems - WMDS The Wastewater Management Decentralised System (WMDS) may be defined as the collection, treatment and discharge or reuse of wastewater coming from households, urban condos, isolated communities, industries or institutions, as well as community sectors existing closet o the waste generation site. The WMDS objectives are: 1) public health protection, 2) protection of the receptor against degradation or contamination, and 3) Reduction of treatment costs through the retention of water and waste close to its origin site in order to reuse them. Figure 5.9 shows that the actual unit costs for wastewater treatment infrastructure are generally higher than those of urban water supply infrastructure (Gunnerson and French, 1996 as cited in Nhapi and Gijzen, 2005). The use of decentralised wastewater treatment and reuse approaches to supplement the existing centralised wastewater disposal paradigm will significantly reduce infrastructure costs for replacement and upgrade of treatment works and trunk mains as well as reducing the pumping capacity and energy costs of servicing cities (Coombes and Kuczera, 2002). Wastewater as a resource The problems associated with the possibility of ensuring adequate water supply and the protection of water sources considering the increasing water pollution have served as a catalyst for the concept of water regeneration and reuse and have elevated it to a subject that is internationally considered a priority.



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Figure 5.9 Economies and dis-economies of scale in water and sanitation systems. The reuse of wastewater in treatment plants and the sub-products generated, such as sludge and gasses; they are an alternative for the efficient use of resources and represents an economic and environmental benefit. Treated wastewater may be used beneficially in activities such as crop irrigation, industrial processes, cleansing or washing activities, among others. The reuse of wastewater may help satisfy the greater demands of water as long as there is an adequate treatment that ensures the appropriate quality for the assigned use. Additionally, wastewater reuse, being an additional source of water, represents environmental benefits such as the decrease in the amount of water used for sensitive ecosystem recreation activities and a decrease in wastewater discharges that reduce and prevent the contamination of water supply sources (EPA, 1998). On the other hand, wastewater treatment plant sludge may be used as crop fertilizers and the gases generated may be used as an energy generation source. In theory, there exist treatment technologies to achieve any desired water quality, but in most regions of the world, and especially in developing countries, the development of sewage treatment plants does not follow that of water use. The main benefits of wastewater reuse are: protection of water resources, prevention of pollution, recovery of water and nutrients for agriculture, savings in clear water use and wastewater treatment costs, etc. (Capra and Scicolone, 2007). The reuse of wastewater may satisfy different water demands as long as it goes through an adequate treatment that guarantees the appropriate water quality for its use (Table 5.3). The water recycled by natural systems provides a clean and safe resource which is then deteriorated by different levels of pollution depending on how, and to what extent, it is used.



Table 5.3 Municipal wastewater reuse categories and possible restrictionsa

Wastewater Reuse Categories Possible restrictions

Agricultural Irrigation

Crop irrigation Commercial plantations

Poor management may generate surface and ground water pollution. Commercialisation of crops and public acceptance

Green area irrigation

School gardens Highway green zones Golf courses Cemeteries Green areas Residential zones

Effect of water quality on soils and crops (especially salts). Public health problems related to the presence of pathogens (bacteria, virus and parasites). Control of use zone, including the buffer zones May represent elevated costs for users.

Industrial recycling and reuse

Refrigeration Boilers Process Water Heavy constructions

Presence of elements that may cause corrosion, carbonate incrustations, bacteria growth and systems pollution. Public health problems, especially the transmission of pathogens by sprays in the cooling water.

Reload of ground water

Aquifer reload Control of salt water intrusion Control de subsidence

Organic chemical compounds present in recovered water and its toxic effect. Presence of dissolved solids, nitrates and pathogens.

Recreation and environmental uses

Lakes and reservoirs Improvement of damp zones Increase of water flow Fish farms Manufacturing of artificial snow

Public health problems due to bacteria and viruses. Eutrophication due to the incorporation of N and P in receptor bodies. Toxicity of aquatic life.

Non-potable urban uses

Fire Protection Air conditioned Toilettes

Public health problems related to the transmission of pathogens in sprays. Effect of water quality on the formation of carbonate incrustations, corrosion, biological growths and system failures.

Reuse in possible uses

Mixture of supply water deposits. Direct water supply.

Presence of elements such as organic chemical compounds with toxic traces and effects. Aesthetics and public acceptance. Public health problems related to pathogen transmission, especially viruses.

a In decreasing order, from greater to lesser use volume. Source: Adapted from Felizatto, 2001 Agricultural use of water resources takes importance due to the high volumes that are necessary (on average, 70% of the extracted water). Water quality and food safety are closely related. Approximately 852 million people around the world suffer hunger, and most of them live in areas without water. In 1994 FAO initiated its Special Programme for Food Safety, being aware that frequently, the lack of water is a key restricting factor to increased food production. As population grows, water needs for agricultural purposes tend to increase. The current trend is not to be self-sufficient in food production, but not to depend of import food requirements, which is be equivalent to importing water (virtual water) (Benites, 2006). Wastewater use in agriculture is increasingly considered a method combining water and nutrient recycling, increase household food security and improved nutrition for poor households. Wastewater irrigation can contribute to achieve of goal 1 (eliminate extreme poverty and hunger) and goal 7 (ensure environmental sustainability) the millennium Development Goals (WHO et al., 2006).



Wastewater irrigation contributes to environmental sustainability by using the nutrients and water in wastewater beneficially for increased crop production, with fresh water, even when artificial fertilizers are used, consequently, the quantity of untreated wastewater discharge into the aquatic environment will be reduced. The challenge is to develop adequate treatment systems to make biologically safe wastewater, but conserving the nutrients that replace the farmer’s fertilizers. Potential benefits include an improved health in human settlements, the survival sustenance of peri-urban settlements, and an improved nutrition as pollution is reduced. The main limitation of these reuse practices is that sewage is generally not (sufficiently) treated before reuse, which introduces public health risks. In 1989 the World Health Organisation (WHO) developed guidelines for the safe use of wastewater in agriculture; the present version (2006) is the result of gathering new epidemiological evidence and the use of Quantitative Microbial Risk Assessment (QRMA). The helminth guideline, based on epidemiological studies, remained essentially the same as was recommended in the 1989, quantitative microbial risk assessments and other relevant information. The revisions being developed are in accordance with the Stockholm Framework that provides a tool for managing health risks from all water-related microbial exposures. The Stockholm Framework encourages a flexible approach to setting guidelines, allowing countries to adapt the guidelines to their own social, cultural, economic, and environmental circumstances. Health based targets define a level of health protection that is relevant to each hazard. A health based target can be based on a standard metric of disease, for water-related exposures, WHO has determined that a disease burden of 1 × 10-6 DALYs per person per year (one ‘microDALY’) from a disease caused by either a chemical or infectious agent transmitted through drinking water is a tolerable risk (WHO, 2004). A health based target can be achieved through a combination of health protection measures targeted at different components of the system. Figure 5.10 illustrates different combinations of health protection measures that can be used to achieve the 10-6 DALYs health based target for excreta related disease. Carr, Blumenthal and Mara, proposed the using a “multiple barrier” approach that interrupts the flow of pathogens from the environment (wastewater, crops, soil etc.) to people. Human pathogens in the fields do not necessarily represent a health risk if other suitable health protection measures can be taken. The available measures for health protection can thus be grouped into five main categories: 1) Waste treatment, 2) Crop restriction, 3) irrigation technique, 4) human exposure control, and 5) chemotherapy and vaccination (Carr et al, 2004). Wastewater use in agriculture is driven by many socio-economic aspects. It supports livelihood of booth marginal and better-establisher farmers, who prize the water and nutrient value of wastewater. In many arid and semi-arid regions, wastewater use may either be the only option, on the only economically viable option available to many groups of people, particularly, but not only, the poorer (Scot et al., 2004 as cited in Bastos, 2007)



T=Treatment DO=Die-off

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Figure 5.10 Examples of options for the reduction of viral, bacterial an protozoan

pathogens by different combinations of health protection measures that achieve the health based target of 10-6 DALYs per person per year

Source: WHO et al., 2006 Cultural beliefs vary so widely in different parts of the world that is not possible to assume that any of the practices that have evolved in relation to wastewater use can be readily transferred elsewhere (Cross, 1985 as cited in WHO et al., 2006) 5.3.6 Solid waste management Currently in developing countries, there are solid waste management practices that have an impact on the urban water cycle. Among these problems are the increase of waste generation associated with economic development and population growth, the lack of mechanisms to educate the urban sector about the way to handle waste from its storage until its presentation to the sanitation service provider, and the existence of waste generators that do not manage their waste and even discharge waste into inappropriate sites, such as green zones and artificial canals or natural water sources. These deficiencies in the urban cycle of solid wastes affect the urban water cycle, resulting in: 1) overload of the self-purification capacity of the water sources, 2) eutrophication of water bodies, 3) congestion in stormwater channels, sewage systems and rivers, 4) plugging in water supply and wastewater plants, and pumping stations, 5) difficulty in water purification processes (Quintero et al., 2005). 5.3.7 Basin Water has conventionally been managed within administrative rather than natural boundaries, in a fragmented rather than holistic manner, and in a technocratic rather than participatory way. Using principles of integrated water resource management (IWRM), integrated river basin management (IRBM) or Integrated Catchments Management (ICM), catchment management initiatives often involve moves toward governance within natural boundaries to manage water more holistically, equitably, efficiently and sustainable. The organisation of water management according to the physical characteristics of a river basin is only one, albeit particularly appealing, form of IWRM aims (Gourbesville, 2008):



To reconcile the aggregate supply of, and the demand for water, as well as among the competing demands for it, through structural and non-structural measures, on the supply as well as the demand side;

To ensure that the watershed, the land that catches the rainfall and translates it into river flows and lake volumes, retains its capacity to do so;

To steer water use in directions that are economically productive, socially equitable and environmentally sustainable.

A basic tenet of catchment management is that what happens in one part of a catchment, as an interconnected system, affects people and environments in other parts. The greater the degree of diversion, impoundment, consumption, pollution and commitment of a basin’s water resources, the greater is the degree of interdependence between users and potential tradeoffs between uses. The acknowledgement that water resource management must consider the integrated nature of water with other ecosystem processes at the catchment scale has directed policy reform and institutional restructuring (Gourbesville, 2008). Self - purification capacity Chemical and biological changes that occur in a river downstream of sewage discharge point. Microbial processes in the river are responsible for the degradation of the organic components. As this is oxygen consuming process, the oxygen level drops over a certain distance (the “oxygen sac”) until it increases again due to re-aeration.

Box 5.4 Ciénaga de La Virgen Case, Cartagena, Colombia The coastal city of Cartagena discharges some 60% of its wastewater into an adjacent natural inland lagoon, which was connected with the sea via a narrow opening. Due to the narrow opening the ‘cleaning’ effects of the tidal differences in sea level were minimal. Via an engineered inlet and outlet system, and a separator extending some 3.2 km into the shallow lagoon, an effective dilution of the polluted lagoon water by fresh sea water was achieved. Via the tidal pressures, sea water is ‘pumped’ trough the lagoon, and algal biomass develops and contributes to the aeration of the water body. The high oxygen levels achieved trigger the growth of heterotrophic bacteria, which boost the self-purification activities in the lagoon.

Source: Beltran, 2003 ; UNESCO-IHE et al., 2004

1. Sand trap 2. Bridge 3. Channel 4. Lock (flood-gate) 5. Metal plate separator 6. Information centre

The decrease in oxygen is followed by an increase in nutrients, which result from the mineralization of the organic matter. Uptake of these nutrients by algae and water plants is



responsible for the subsequent decrease further downstream (UNEP et al., 2004). These changes in water chemistry, or water quality, have a strong impact on the organisms that live in the affected river. Only the most ‘resistant’ animals will survive. Depending on boundary conditions (temperature, flow, velocity), a river can handle a certain amount of organic waste without problems. However often this self purification capacity is largely overstretched by too large amounts of waste. The self-purification capability is understood as a process in which different mechanisms act, helping to assimilate or transform organic and inorganic matter. The interaction of these mechanisms is complex and has been studied through mathematical models. The first models were developed by Streeter and Phelps in 1925. 5.4 SOCIO-CULTURAL AND INSTITUTIONAL ASPECTS The adoption of the catchment as a framework for managing water and other resources has dominated water management discourses for close to two decades. The shift to catchments based management reflects a move towards more holistic management of water within its ecological context and an acknowledgement that politically determined administrative boundaries often bear no relation to natural ecosystem processes (Blackmore, 1995; MDBC, 1999 as cited in Gourbesville, 2008). River basin management is a complex task. Therefore, instruments that help to assess the present situation and assist in the development and evaluation of solutions may be important. Two types of support can be distinguished; support of operational management and support of strategic policymaking and planning. A second distinction is between support systems for monitoring, data collection and processing, oriented towards making facts and figures about the ‘‘as is” situation available; and tools and systems to support decision-making with a view to the future, typically oriented to the ‘‘ex ante” identification, analysis and evaluation of alternative allocations, policies or plans (Gourbesville, 2008). Water use and the role it plays for social and economic development and for environmental change, may be seen as the outcome of three types of management systems (Figure 5.11). The predominant system has been one where the public sector plays a major role, whereas currently the importance of the two other systems is growing. The absence of a policy where the social conditions and the links between the socio-economic system and water and the environment are duly recognised, improvements in water resources situation likely to remain a distant dream. Changes in official policy are slow to come in most countries. The build up of viable and effective institutions within civil society is also a considerable challenge. It is clear though, that while the formal government must rule, this is not always effective from a social, equity point of view and the effects from prevailing management on an environmental count, shows a most worrisome trend.



Overall Framework ManagementSystem

Type of Organisation/Institution

Characteristics of Water User

Response to Police& Management

Outcome of Policy& Management

Gobernment

Formal Institution &

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Hoseholds, NGOs & CBOs,

independent Water Users,

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Use

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Ass

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Services

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Resource Manager, Stakeholder and

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Human Behavio-ur and Water

Use

Implications for Water Resources

Social and Economic Outcome

Figure 5.11 Three types of management system and the context in which they operate.

Arrows show hypothetical direction of relationships and response Source: Lundqvist et al., 2001

The role of civil society is becoming a key interceding variable. The situation is dynamic in nature, and it is important to capture the essence of hydro-social interdependencies to enable analysts and planners to understand these relationships better. It is hard to see any realistic alternative to a management system where civil society, in broad sense, and government agencies are carrying out various tasks in tandem. It is important to make an emphasis on integrated planning using an interactive, systematic process in which decision making is the result of a social learning process, which shall be supported by a multi-objective system based on identification systems and decision and control theories (Carson et al., 2006) In essence the approaches generally have several key features, which derive largely from the general features of Integrated Water Resource Management (IWRM) and Integrated Catchment Management ICM. - Public participation and collaboration is a key feature of management and catchment

decision-making. - An integrated, systems approach should be used to considering interactions between

biophysical, ecological and socioeconomic drivers, processes and impacts. - A balance needs to be achieved between economic and environmental objectives,

requiring assessment of social and economic impacts from policies and not only biophysical impacts.

- Good condition targets are set by which environmental performance and improvement are measured.

The Water Framework, and similar policies internationally, require advances in research efforts to help meet these goals: improved participation methods and understanding of their use need to be developed; science and modelling need to be undertaken in a more holistic,



integrated way; methods for evaluating economic and social impacts of policies need to be developed and implemented; and, scenario based approaches need to be developed to allow testing of potential policies and management changes to test their potential impacts on environmental quality and other indicators before these policies are implemented. Acreman (2004) discusses the challenges of linking science and decision-making, considering the need for risk and uncertainty to be represented when applying results and for partnerships between scientists and policy makers. He concludes that there is no real gap between scientists and decision makers, but that there is a need for scientists to promote partnerships with decision makers, and some difficulty in deciding where the job of scientists ends and decision makers begins. Overall he stresses the continuum of expertise from basic science to applied science to decision makers. Pereira et al. (2004) develop a quality assured information system for the improved governance of groundwater resources at the catchment and sub-catchment levels. It requires the design and implementation of a Tool to Inform Debates, Dialogues & Deliberations (TIDDD), combining traditional features of Decision Support Systems (DSSs) (such as organisation of the information and tools for exploitation of the information) with an awareness of the new context of management and governance in which they are embedded. Tippett (2004) describes the design ways tool for participation in decision-making. The development of this tool was a conscious attempt to embed ‘new paradigm’ living systems metaphors into a tool for design and decision-making. 5.5 FINANCIAL AND ECONOMIC ASPECTS The cost of pollution control became the central theme of environmental economics in the late 1960s and '70s. Perhaps the key insight from those years was that, if environmental damage can be quantified in monetary terms, then the benefits of pollution control can be expressed as an increasing function of the degree of control, but the marginal benefits decline toward zero. Meanwhile it is easily demonstrated that both the cost and the marginal cost of control tends to increase as the degree of control approaches 100%. It follows that there is always an optimum point where the marginal cost of control is equal to the marginal benefit, and further reductions of emissions cost more than they are worth e.g. (Kneese and Bower, 1972 as cited in Ayres, 2007). This is shown schematically in the Figure 5.12. It follows from this simple insight that popular ideas like “zero emissions” make as little sense economically as they do in physical terms. However, measures to abate or compensate for environmental damages do have real monetary costs, and available funds are always limited (Ayres, 2007). The next question for economists was: ¿how should the external costs be allocated?, this aspect of the cost problem has been addressed as the “Polluter Pays” Principle (PPP), emphasised in many of the international discussions, especially at the Rio Conference (UNEP, 1992 as cited in Van-Hauwermeiren, 1998).



Figure 5.12 Emission reduction vs. marginal cost

One tool is the internalisation of externalities, namely to consider the various environmental impacts and externalities are manifested either by an assignment that extends over an ecosystem and the people there, or be transferred to future generations. This requires economic valuation of the affected resources and returns these externalities to be present value of the property transferred to the user environment (Van-Hauwermeiren, 1998). From the environmental economy point of view, external factors may be monetarily appraised. In other words, it is possible to ecologically expand the market (market being understood as the satisfaction of population and industrial needs). However, from the ecologic economy point of view, money values arbitrarily appraise the irreversible and uncertain effects of the actual actions and their impact on future generations. This means it is necessary to externally set limits to emissions according to a social evaluation scientific-political debate. It is important to acknowledge that in spite of giving an economic value to the environment, there must be some growth limits associated to environmental limits, which promotes a change in the development model, aiming towards sustainable development. The possibility that pollution would inhibit economic growth directly (albeit in unspecified ways) was suggested in the report to the Club of Rome entitled “Limits to Growth” by Meadows et al., (Meadows et al., 1972 as cited in Ayres, 2007, Escriu, 2006). The Brundtland Report of 1987 (Our Common Future), defined the “sustainable development” concept in reference to the demographic and industrial growth, in accordance to the environmental limitations. Sustainable use of natural resources is one of the main activities held by the VI Environmental Program of the European Union and in terms of water management; it promotes sustainable water use as an objective of the Water Framework Guidelines (Escriu and Vázquez, 2006). How can a country that has accepted the sustainability challenge determine if it is making progress toward sustainable development? Measurements are needed. These indicators must not only reflect changes in quality of life, but must also show if these changes are compatible with the planet's current ecological limits. While a precise and complete



definition of sustainability may be elusive (Carter, 2001 as cited in Moran et al., 2008), it is possible to define measurable bottom-line conditions for both human development and ecological sustainability. Following Boutaud (2002) and use the UN Human Development Index (UNDP, 2005 as cited in Moran et al., 2008) (HDI) as an indicator of development and the Ecological Footprint (Rees, 1992; Rees and Wackernagel, 2004; Wackernagel and Rees, 1996; Wackernagel et al., 2002, 2005) as an indicator of sustainable consumption (Moran et al., 2008). The footprint approach, has not only taken important steps to synthesizing many measures of environmental degradation into a single proxy, but also managed to net out a country's ability to regenerate nature (which is usually referred to as biological capacity or bio-capacity). The biological capacity or bio-capacity can be considered as nature's capacity to supply useful biological resources, and to absorb waste materials generated by mankind, given prevailing technologies/practices (Bertinelli et al, 2008). . If humanity overtaxes the biosphere's regenerative capacities, natural capital is being liquidated and wastes accumulate. Development and resource use can therefore be sustainable only if, over time, their demand on nature stays within the regenerative capacity of the planet. The Ecological Footprint measures how much of the regenerative capacity of the biosphere is used by human activities (Moran et al., 2008). Worldwide demand continues to grow, not only in absolute terms, but faster than population growth. Evidently a new and radically different development trajectory is needed. Some would call it a new paradigm. We must concentrate, in the future, on increasing resource productivity. In effect, goods must be converted as much as possible into services, and services must be delivered with the minimum possible requirement for material and energy inputs. Figure 5.13 shows schematically the limits of eco-efficiency as applied to the manufacturing economy, vis a vis a pure service economy. It is convenient economy “zero-emissions”, in as much as it is an economy in which all materials that are intrinsically scarce must be recovered, repaired, reused, remanufactured or – as a last resort – recycled. The result is the search of a win-win alternative with a more efficient use to satisfy the same needs. This search is oriented towards the optimisation of investments in terms of the benefits obtained by the people and the environment. In other words, a cost-effective analysis is made. Cost-effectiveness analysis is proving an increasingly important tool in the allocation of funds within the health sector, although cost-benefit analysis remains the form of economic evaluation most useful for resource allocation to different government financed activities. While there are many criteria for allocating resources to different ministries and government programmes, the relative economic costs and effects of different programmes and interventions remain critically important. Therefore, economic evaluation including cost-benefit analysis should not only aim to provide information on economic efficiency, but also provide other policy-relevant information on who benefits and, therefore, who may be willing to contribute to the financing of interventions (Hutton and Haller, 2004).



Figure 5.13 Towards the spaceship economy: three stages in eco-efficiency

Source: Hutton and Haller, 2004 The Water Framework Directive uses the “cost effective” concept as an attribute of the different measures to be implemented to achieve the proper water status by 2015. The Merriam-Webster dictionary defines “effective” as: Economical in terms of tangible benefits produced by cost-effective measures to combat poverty (Escriu and Vázquez, 2006). The cost-efficiency analysis is used in micro-economy as an instrument for the financial evaluation of projects and in general, is considered as a variable of the cost-benefit analysis, in which costs are evaluated in monetary terms and the benefit is explicitly pre-set through a determined degree of efficiency for the achievement of the objective. In this sense, this type of analysis has certain degree of interest during the initial stages of the decision process, when the objective is to immediately reject those solutions that have an out of proportion cost (Escriu and Vázquez, 2006). The “cost-efficient” analysis differs from the “cost-benefit” analysis since the latter understands an efficient option whenever the gain is greater than the loss. This means “the winners may exactly compensate the losers and remain better than before, or another efficient option is when the sum of benefits is greater than the sum of expenses, independently from who are the winners or losers” (Kaldor-Hicks criteria). Therefore, the cost-benefit analysis would sort the different measures in term of their net benefits and not based on its application cost, as done in the cost-efficiency analysis (Escriu and Vázquez, 2006). It can be noticed that investing in sanitation and water supply projects would provide economic benefits since there would be an economic benefit ranging between US$ 3 and US$ 34 per each US$1 invested, depending of the region. It is calculated that in order to reduce by half the amount of persons lacking sustainable access to improved water supply and sanitation services, it would be necessary to increase the actual investment of approximately US$ 11,300 million per year. Among the benefits obtained would be a 10%



decrease in diarrhea episodes in the entire world and a total annual economic benefit of US$ 84,000 million (WHO, 2004). At government level it is important to motivate the implementation of sustainable projects for which it is necessary to make an environmental economic evaluation and therefore, the implementation of economic policy instruments in order to obtain the sustainable management of natural resources. Among the environmental policy instruments are: (Van-Hauwermeiren, 1998): Volunteer mechanisms Regulation Governmental expenses Economic instruments

The main objective of the economic instruments is not the simple collection, but the modification of the consumers behaviours in order to cause a permanent incentive to decrease pollution. On the other hand, it stimulates the use of non-polluting technologies based on social objectives set according to certain environmental services quality, without having top ay excessive costs, but a fair price (Sánchez, 1996 as cited in Van-Hauwermeiren, 1998). Economic instruments allow the affected stakeholders choose between degradating the environment paying a high Price for ir, or not doing it and receiving a reward (Hanley et al,1997; OccDE, 1994 as cited in Azqueta, 2002). Developed countries simultaneously use command and control regulation instruments and economic instruments. In the case of Latin American countries’ regulations, the use of command and control instruments is a characteristic, although there are some cases of the application of instruments based on the market, having reported good results.

Chapter 6. Pollution control of Cali city versus the new paradigm in the urban water management


6 POLLUTION CONTROL OF CALI CITY VERSUS THE NEW PARADIGM IN THE COMPONENTS URBAN WATER CYCLE

6.1 HOUSEHOLD Households are the basic units of drinking water consumption and wastewater generation (82% of the water produced is for residential use, DAPM, 2007). It is noted that the service provider company (EMCALI) does not have influence over water use since EMCALI’s internal regulations provide the water supply and sewage service specifications and recommendations for each specific connection diameter. It also establishes that all work made inside individual households and buildings and the maintenance of domiciliary facilities after the gauging meter are the sole responsibility of the subscriber and not that of EMCALI. (EMCALI, 2001b). Likewise, plans of institutions related with the water supply and sanitation sector, such as DAGMA, CVC, DAPM, and EMCALI, mention the need for the efficient use of water. However, plans and projects proposed for execution during the next seven years show that work activities are concentrated on the civil works at matrix or secondary network levels, without having proposals for water use efficiency projects inside individual households and buildings (EMCALI, 2007). Household water consumption has decreased during the last years mainly due to tariff increases and decreases in granted subsidies, as shown in Figure 6.1 (Junca, 2000). Notwithstanding the consumption reduction in the different economic levels, Strata 6 still shows a consumption of 37 m3/month per household, or an average of 274 L/inhab*day. However, the hydraulic designs for this socio-economic level in the future urban development zone have been made using an average of 340 L/inhab*day (EMCALI and Hidroccidente, 2006), surpassing the actual average consumption, without considering that this sector has the possibility of implementing new strategies and/or technologies to reduce the actual water consumption per inhabitant. With the technological development and commercialization of low consumption devices, some households are using these products in order to reduce water usage, especially in the newest constructions. The installation of these types of devices has been voluntary since there is no institution in charge of verifying their effective use, although Decree 3102 of 1997 regulated by Article 15 of the efficient water use law makes it mandatory to install low water consumption equipment and systems to replace existing high usage equipment and systems that have water leaks in the internal connections after the gauging meter. The same decree also mentions low water consumption equipment, systems and implements by the service provider. This, to date, has not been established, and new water supply and sewage standards are awaited.



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Figure 6.1 Water Consumption per Household in the City of Cali.

Source: Junca, 2000 Grey waters or storm waters are not used at household level. These are discharged into the sewage system; in some cases, in an individual manner and in others, in a combined manner. With respect to the sewage system usage, there is an improper use of the system in which EMCALI, due to the lack of a regulating and sanctioning policy with respect to the problem generated inside households, does not have the governance to control the improper connections and therefore, the proper use of the sewage system. Actions and technologies associated with the efficient use of water in individual households are technically feasible, both in the consolidated areas, as well as in the future expansion area. In order to promote these practices, progress has been made in terms of standardization levels. However, it is important to implement application mechanisms for these laws and decrees, with the service provider companies playing an important role, who shall inspect for conformity of installations inside households in addition to the external networks. 6.2 INDUSTRY As in the case of water consumption in households, the average consumption of water at the industrial level has decreased from 51 to 42 m3/month between 2000 and 2006 (EMCALI 2006 as cited in DAPM, 2007). There is also less stimulation due to the service cost and the influence of new technological reconversion processes of some industries within the Cleaner Production Project framework.



Discharges made directly into the sewage system by industry located in the urban area are monitored by DAGMA, which is the entity in charge of controlling only the parameters established in the standards (Decree 1594/1984). This urban environmental authority in its 2019 plan framework has the objective of implementing cleaner production and promoting green markets as a strategy to decrease pollution. However, up to this date, there are still some sanitation substances (Phenols, Cr+6, Lead, Mercury, Cooper) being discharged into the drainage system (Universidad del Valle, 2008) which do not comply with Colombian legislation (Article 72, Decree 1594/84), causing a dramatic effect on the southern drainage system of the city, as can be seen in Table 6.1.

Table 6.1 Comparison of recorded hazardous substance’s values (2006), in the South Drainage System, with the Colombian regulation.

Sampling point Phenols (mg/l)

Cr +6 (mg/l)

Lead (mg/l)

Mercury (mg/l)

Copper (mg/l)

Cañaveralejo Channel 0,04 0,03 0,03 0,001 Ferrocaril Channel 0,1 0,03 0,04 0,005 0,07 Cañaveralejo river 0,04 0,01 South Channel 0,09 0,025 0,03 0,001 0,06 Líli river 0,05 0,02 Melendez river 0,05 0,01 Cauca river (before South Channel) 0,01 0,02 0,01 0,002 0,02 Cauca river (after South Channel) 0,01 0,03 0,01 0,02 0,004 Decree 1594 de 1984 art 74 0,2 0,5 0,5 0,02 3 Decree 1594 de 1984 art 38 0,002 0,05 0,005 0,002 1

Source: Universidad del Valle, 2008 At the industrial level, there is interest in cleaner production and technological reconversion processes oriented mainly towards obtaining economic benefits associated with product recovery and minimization of the consumption of raw materials, such as water, since it impacts supply, disposition and treatment costs, as well as the compensation tax. 6.3 WATER SUPPLY SYSTEM The accelerated population growth of Cali, with a factor of approximately 19.5 (Botero, 1991 as cited in Velásquez and Meyer, 1994) generated a crisis in the public services capacity and coverage. Water supply was provided with the construction of the Cauca River Treatment Plant in 1958 and the later start up of the Puerto Mallarino plant (Vásquez, 1995 as cited in Jiménez, 2005). However, the drinking water production policy has been aimed at increasing the production capacity of the potabilization plants in order to satisfy the city’s demand. Surface water is the main supply source (the Cauca River provides 77% of the city water). Currently there are no alternative water sources such as storm or grey waters. Besides, these are not associated to the different uses and/or the different qualities required for each type of water. Drinking water is used for multiple home uses. The exclusive dependency on the Cauca River of Cali’s inhabitants has generated critical situations because the river’s contamination problems cause service interruptions (February, 2009 – More than 72



continuous hours without water service, El País, 2009), leaving the population without water for all uses and generating sanitary conflicts. In terms of valve and pressure control, EMCALI regulates the system, guaranteeing a minimum pressure of 10 mca at the furthest point, which contributes to control water losses and consumption. In terms of losses, EMCALI, in its Department of Technical Planning, has a functional area responsible for water supply losses which is in charge of projects to reduce losses and carries out the follow-up of the variables affecting the non-accounted for water losses and operative areas. This becomes evident with the lack of programs associated to the sanitation plan. (EMCALI, 2007b). Although Law 373 of June 6, 1997 establishes the implementation of the program for the efficient use and conservation of water, which would contribute to the prevention and minimization of pollution, the plans of the environmental authorities and the service providers are not established in concrete projects. The law states that the plan shall contain annual loss reduction goals and education campaigns for the community, among other actions, but are not specified. It also establishes the mandatory reuse of water, which presently is not conceived as an alternate supply source for the city of Cali. 6.4 WASTEWATER COLLECTION AND CONVEYANCE With respect to wastewater transportation and collection, in 1955 the first master plan proposed an individual sewage system for Cali, which corresponds to only 25% of the total system. In practice, it has turned into a combined sewage system because of the improper connections made by users due to their lack of knowledge of the sewage system’s use and operation, as well as the implications of improper connections. (EMCALI, 2007b). Actions throughout the wastewater transportation, collection and treatment evolution have been oriented to correcting problems generated by the city and its poor planning, solving in many cases, situations in which individuals that have seen their economic interests affected, instead of generating preventive plans focused on decreasing human risk and environmental impact. These actions have focused on civil works and have not approached education, minimization, control and preventive actions as strategies. 6.5 STORMWATER DRAINAGE SYSTEMS Considering the fact that the POT regulates only 18% of green zones for urbanization projects (DAPM, 2000), the high impermeabilization of the urban area has generated a low storm water retention capacity and therefore, an increase in the contamination load flow resulting from deforested soil wash-off and particulate material discharged into the water bodies. In the east drainage system, two lagoons, one denominated the Pondaje (South) and the other Charco Azul (North), were constructed for the regulation of storm water in the city and for the regulation of the frequent flood events present in this area. The lagoons have lost their initial hydraulic capacity due to the presence of illegal slums in the area, through the continuous debris landfill and invasions that increase flooding risks with an additional



problem associated with the direct disposal of wastewater and solid residues into the lagoons (EMCALI, 2007b). The Southern drainage system of Cali, which was initially conceived as a rainfall sewage system and that has been affected by erroneous connections (EMCALI, 2007b), shows water quality problems associated not only with the presence of wastewater, but with the general wash-off of the water runoff, and in particular, occurring after long dry periods. Monitoring studies have shown that these stormwater discharges represent a negative impact on the Cauca River’s water quality (Universidad del Valle, 2008). This spillway is located before the drinking water intake, generating interruptions in the potabilization plant operation (Universidad del Valle, 2008). Stormwater contamination is associated with subnormal settlements in the upper part, which have caused deforestation in the basin, contributing to solid waste and sedimentation in the river systems (EMCALI, 2007b). DAPM and EMCALI emphasize the control, management and social work for this situation; however these institutions are not unified to take the actions necessary to control such settlements. EMCALI’s sanitation plan does not present a program that defines such activities, while DAPM presents it in an independent manner, with different scopes. EMCALI’s actions are concentrated in the replacement of networks, the maintenance and construction of the separation structures and in general, to the civil works in order to reduce wastewater discharges into the river systems (EMCALI, 2007b). 6.6 WASTEWATER TREATMENT AND REUSE The first Sewage Master Plan made in 1955 developed a proposal for a decentralized wastewater management according to the city’s topography and its possible expansion, locating three sites for future wastewater treatment: WwTP-Cañaveralejo, WwTP-Río Cali and WwTP- South. This proposal was still valid in the 80’s, when a liquid discharge decontamination plan was proposed, based on pre-feasibility and feasibility studies for wastewater treatment in the city of Cali. According to this plan, the WwTP- Cañaveralejo would capture the main collectors and interceptors of the sewage system with an approximate coverage of 85% of the wastewater, WwTP-Rio Cali would capture the wastewater generated in the north-western area of the city, transported by the marginal collectors of the Cali River, with an approximate coverage of 15%, and Southern WwTP, which would capture the waste water generated by future urban developments (Llanos, 2000). The current WwTP-C has a designed capacity of 7,6 m3/s, which will allow treating approximately 70% of the waters collected in Cali during the next years. Therefore, EMCALI has executed and planned works with the objective of centralizing the system, transferring the north-western wastewaters to the WwTP-C (Llanos, 2000). Pumping towards the WwTP-C is considered for the future development area, where the water could be managed independently with the goal of taking advantage of the existing infrastructure and optimizing the initial investment costs (EMCALI and Hidroccidente, 2006).



Pollution control investments and strategies executed during the last years have not contributed in an efficient manner towards improving the receptor source’s water quality. This demonstrates that these actions and resources are not sufficient and have not been invested in an efficient way. This situation can be seen in Figure 6.2, where DO measurements made by CVC in 19 stations along the Cauca River between 1985 and 2003 indicate that the DO values have decreased throughout time in spite of the start up of WwTPs in different municipalities having an average population of approximately 16,000 inhabitants with the exception of Cali, with 2,200,000 inhabitants. These treatment plants are: WwTP-Ginebra (1993), WwTP-Roldanillo (1995), WwTP-La Union (1995), WwTP-Guacari (1996), WwTP-Toro (1996), and WwTP-Cañaveralejo (2001).

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Figure 6.2 DO in Cauca River. Summer conditions

Source: Sandoval and Ramírez, 2007 In general terms, the pollution control actions promoted to this date have been oriented towards centralizing the system and collecting the wastewater at the WwTP-C. The applied technologies have a trend to use activated sludge type systems and advanced primary treatments which require considerable amounts of energy and chemical products, which in turn, represent the transference of the problem in space and time, but not its eradication. These treatments are a solution to a short term, punctual or local perspective of pollution, but do not meet the concept of integrated management. Wastewater is not regarded as a resource, and is discharged into the receptor body. This is a potential resource, having in mind that the zone next to the plant has sugar cane fields which can be irrigated with this effluent. Studies have been made for this possibility and are mentioned in more detail in Chapter.7.



Universidad del Valle made a scenario modeling study for CVC in 2005 in order to define pollution control plans. These scenarios were projected for 2010, 2013 and 2015, defining different contaminant load level and removal combinations in the municipalities and industries that discharge their wastewater into the Cauca River. In conclusion, the study demonstrated that the Cauca River pollution control, mainly based on compliance with the allowed load limits and the construction of treatment systems (end of pie solutions), do not generate a strong impact on the improvement of the receptor source’s water quality (an average increase of 0.6 mg/L of Dissolved Oxygen in the most critical point of the Cauca River, the Paso de la Torre Station) with relation to the high investments required in the sector. Therefore, it is necessary to complement the strategies proposed by the institutions involved with the Water Resource Integrated Management concept. (Universidad del Valle, 2008). 6.7 RIVER BASIN As mentioned in Chapter 4, the management of the Upper Cauca River Basin is the responsibility of five institutions that offer different plans and programs, which in most cases are not coordinated among themselves. There are other institutions of the city involved with contamination sources such as EMSIRVA, related to the inadequate disposal of solid waste, or DAPM, related to the subnormal settlements in the upper basin of the tributaries from the urban area of Cali to the Cauca River (Universidad del Valle, 2008). The objective of CVC, CRC and DAGMA , the environmental authorities, is to enforce national regulations such as Law 99 of 1993, Decree 1594 of 1984, Decree 3100 of 2003, or to verify local compliance with Resolution 06686 of 2006 (CVC) and Resolution 376 of 2006 (DAGMA), which present the quality objectives and the contaminant load reduction goals. These resolutions establish the demands that the environmental authorities make to EMCALI, ignoring that implicitly these institutions are part of the problem and therefore, are responsible for issues such as deforestation and the subnormal settlements in the basin that through surface wash-off, generate the arrival of considerable amounts of sediments into the river and sanitation systems, which finally have to be removed by the service provider company in order to not affect the drainage system operation. (CVC and Universidad del Valle, 2007a). The present water management status and inconveniences found in Cali are related to diverse aspects affecting all institutions. Therefore, the solution shall be coordinated and not the sole responsibility of the service provider. 6.8 TRANSVERSAL ASPECTS 6.8.1 Social, Institutional and Regulatory Component The environmental management system at the regional level works through the Regional Autonomous Corporations (Corporaciones Autonomas Regionales - CARs), the Urban Environmental Authorities (Autoridades Ambientales Urbanas (AAUs), and in the case of Cali, CVC and DAGMA, which are responsible for implementing and enforcing programs and policies. A key problem with Colombia’s environmental regulatory system is that some



CARs and AAUs are quite weak. As a result, the system exhibits tremendous disparities in monitoring and enforcement across the jurisdictions (Blackman et al., 2005; Meléndez and Uribe, 2003; Gómez and Torres, 2003 as cited in Blackman, 2009). The evolution of legal standards related to water contamination has been oriented towards command and control policies. Colombian command and control (CAC) policies for water quality regulation is conventional. All dischargers of liquid wastes shall be registered and must obtain a permit from their regional environmental authorities. Permits must be renewed every 5 years. Most are essentially permissions to discharge and do not specify the different pollution abatement methods, equipment, or strategies. In addition, all discharges are subject to 1984 effluent concentration standards for 22 organic and inorganic substances. Discharges that began operating after 1984 are required to remove at least 80% of total suspended solids (TSS) and at least 80% of BOD from their waste streams. Older facilities are allowed to adhere to slightly less stringent requirements. None of Colombia’s emissions standards are industry-specific. CARs and AAUs are responsible for enforcing the emissions standards. In doing so, they may inspect the discharging facilities at any time to sample their effluents and check their equipment (Blackman, 2009). Among the regulations and policies, concepts such as sustainability and cleaner production are included, as well as tools such as prevention and control, among others. However, these are difficult to implement, because the strategies for their implementation are not specified and are presented as an option and not as an effective regulatory demand. An example of this is Law 373 for the efficient use of water, or Law 812 for Water Integrated Management, emphasizing pollution prevention and control, but which are not currently mandatory. 6.8.2 Financial and Economic System In Colombia, the economic tool implemented for pollution control is the retributive charge initiated in 1997. Law 99 of 1993, which is Colombia’s second major comprehensive environmental law, established the legal foundation for a national discharge fee program. Article 42 mandates CARs and AAUs retributive charges for water effluents. It also appears to ensure that regulatory authorities avoid one of the most common implementation problems experienced in the discharge fee programs in developing countries: setting fees that are too low and therefore do not have an incentive effect. The CVC CAR is widely recognized as a relatively capable institution, particularly with regard to water resource management. Prior to its discharge fee program, CVC made significant efforts to enforce CAC emission standards, and compliance rates were high. Therefore, discharge fees were charged only on BOD and TSS emissions below the standards. Between 1998 and 2000, total BOD discharged by point sources participating in the fee program fell 32%, while TSS discharges fell 69%. The report acknowledges that discharge reductions from sugar processing plants and the paper industry, due to the implementation of pollution-prevention measures and clean technologies (versus end of pipe treatment), contributed to these results (Blackman, 2009).

Chapter 7 Proposal of wastewater pollution control strategies for the city of Cali


7 PROPOSAL OF WASTEWATER POLLUTION CONTROL STRATEGIES FOR THE CITY OF CALI

7.1 GENERAL OVERVIEW The strategies for pollution control oriented towards the paradigm shift in the wastewater management of Cali were formulated in two stages. In first stage, a revision and analysis was made of alternatives and strategies proposed by institutions in the different local and regional plans and in the studies and research carried out in the study zone. The second stage considered the alternatives for the paradigm change, including the following basic elements: Influence sectors Scope of strategies Components of urban water cycle Socio-economical, institutional and regulation aspects

An action matrix oriented towards integrated water management at short, medium and long term was built for each of the city sectors. The different water management alternatives in the drainage zone emerge from the combination of the different actions that include time, space and the urban cycle of water. These alternatives are framed and accompanied by the social actions, considering at the same time, the institutional aspects, the economical instruments, and the political and regulatory tools. They are related to the identification of the decrease in environmental impacts, living quality improvement and the evaluation of the economic costs. Influence Sectors of the Proposed Alternatives Considering the future trends of the planning and future growth of Cali, the sewage drainage areas and the perspectives of directing most of the waste water towards the WwTP-C, was divided into 3 work sectors, as seen in Figure3.1. Sector 1 – Area of the City Draining towards the WwTP-C: corresponds to the Eastern

and North-western Drainage systems. Presently these two drainage systems are joined through the channel of Floralia until the WwTP-C. This zone drains an important city sector and concentrates most of the collectors, pumping stations and storm water canals. Main environmental problems occur due to the presence of waste and debris in the canals, human settlements and invasions, the deterioration of the separation structures, and erroneous connections, among others

Sector 2 South Drainage System: This system drains by gravity through the storm and

wastewater canals and collectors, part of the south-western sector of Cali, up to the Southern Canal. The final wastewater discharge is done directly into the Cauca River before the water supply intake site for the water consumption of more than 70% of the population of Cali.



Cali River mouth

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Figure 7.1 Influence sectors of the proposed strategies for the management of wastewater in

the city of Cali



The impact of the drainage spill is reflected in the variations of the Cauca River’s water quality, with the resulting risk increase in the water supply due to: presence of sanitary substances coming from the industrial sector’s direct spill into the sewage, contamination due to organic matter and pathogens, solid waste and leachates from the final disposal site, erroneous connections, presence of solid waste in the stormwater channels, presence of solids and sediments as a consequence of the deterioration of the Meléndez, Lili and Cañaveralejo River basins, sediment re-suspension phenomena due to the first basin wash-off which causes pollution peaks in the Cauca River, among others.

Sector 3 – Expansion Zone. This is the area of the city’s future urban development. It is formed by the Cali-Jamundi corridor sector and the Navarro Deferred Regime Area. These areas represent an opportunity to implement a wide range of alternatives and new concepts oriented towards wastewater sustainable management.

Scope of Strategies The validity/execution period (short, medium and long term) was considered in the analysis and proposal of strategies. The definition of short term is a period between 0 and 10 years, mid-term between 10 to 20 years and long-term is ≥20 years. Components of the urban water cycle Oriented towards the wastewater management paradigm change, the proposed strategies considered the different components of the urban water cycle in order to provide integrated and sustainable alternatives. These components are: Household Industry Water supply system Wastewater collection and transport Stormwater drainage system Wastewater treatment and disposal Solid waste management River basin

The main characteristics of these components have been discussed in Chapter 5 of this document. Social-economical, institutional and regulation aspects The proposal of technological strategies for wastewater management in Cali considered different options oriented towards the change of paradigm under the economic, political, regulatory and institutional terms that would make technological changes viable and feasible 7.2 PROPOSED STRATEGIES BY INSTITUTIONS



7.2.1 Strategies and projects proposed by the institutions in regional and local plans The identification of the strategies proposed by the institutions with regards to city wastewater management considered the review of the different local and regional plans and projects (See Plans and Projects Report). A total of 7 plans were reviewed, including 3 regional and 4 local plans. Table 7.1 shows the different reviewed plans.

Table 7.1 Inventory of regional and local plans Name Proposed by Validity period

(years) Term

REGIONAL PLANS Regional Plan for the Management of the Environment in Valle del Cauca Department (PGAR) (CVC and Universidad del Valle, 2004)

Regional Corporation of the Valle del Cauca (CVC)

2002 – 2012 (10) Short -term

Triennial Action Plan (PAT) (CVC, 2007b).


2007 – 2009 (3) Short -term

Plan for the development of the department (PDD) (Gobernación del Valle del Cauca, 2008)

Valle del Cauca government 2008 – 2011 (3) Short -term

LOCAL PLANS Land Ordering Plan (POT) (DAPM, 2000)

National Planning Directive (DNP) – Cali Majoralty

2000 – 2009 (10) Mid -term

Municipal Plan for the Management of the Environment (PGAC) (DAGMA and ASOCARS, 2005)

DAGMA - ASOCARS 2005 – 2019 (15) Mid -term

Plan for Sanitation and Management of Wastewater Discharges (PSMV) (EMCALI, 2007)

EMCALI 2007 – 2016 (10) Short term

Plan for the development of Cali (PDC) (Alcaldía de Santiago de Cali, 2008)

Cali Majoralty 2008 – 2011 (3) Short -term

The review showed that in most of the plans the conceptual base used varied. Therefore, articulating these plans is complex and does not follow the same baseline, in spite of being proposed for the same type of action (local or regional) and for the same execution period (i.e., PDD; PDC, y PAT). One of the factors that has limited the development and implementation of the different plans considering waste management in the city is related to the sectorization of the competencies of the institutions or stakeholders involved in the problem, whether it is at a local or regional level. There is also a lack of follow-up and effective control over the execution level of plans and the achieved results. The general characteristic of the plans is that they have to be executed at short and medium term, depending on the local and regional administration terms (Table 7.1). As a result of this, whenever there is a change in management (every 4 years) there is a lack of articulation between the proposed plans of the administration finishing its mandate vs. the management taking over. This is reflected in the fact that no plan continues with the plans that have been already initiated, resulting in a loss of resources, credibility, efficiency, etc.



Considering the water urban cycle components, the main strategies or activities were extracted from the reviewed plans in terms of Cali’s wastewater management (See Annex 2). Table 7.2 shows a summary of the strategies proposed by the institutions classified according to the urban water cycle.

Table 7.2 Strategies proposed by the institutions for wastewater management considering the urban water cycle

Regional plans Local plans Item PGAR PAT PDD POT PGAC PSMV PDC Household x x Industry x x Water supply system x x x x Wastewater collection and transport x x x x x x Stormwater drainage system x x x x x Wastewater treatment and disposal x x x x Solid waste management x x x x x River basin x x x x x x Notes: PGAR - Regional Plan for the Management of the Environment in Valle del Cauca Department; PAT - Triennial Action Plan; PDD - Plan for the development of the department; POT - Land Ordering Plan; PGAC - Municipal Plan for the Management of the Environment; PSMV - Plan for Sanitation and Management of Wastewater Discharges; PDC Plan for the development of Cali As shown in Table 7.2 most of the plans do not consider a framework plan in which integrated strategies are proposed for the urban water cycle. These strategies are proposed for the three study sectors. Following is a brief description of the strategies for each of the urban cycle components: Household: The Household strategies and projects proposed are oriented towards the construction and urbanization of the city, as well as its urban growth control, some of them including new orientations and national and international policies framed within a new urban development habitat model (i.e., the expansion area). However, wastewater management is not clear and is approached in a general manner Industry: At the industrial level, the regional proposed strategy is focused towards the reduction of contamination loads through the implementation of Cleaner Production policies for the reduction of at least 30% of the current contamination in the Cauca River caused by chemical and industrial wastewater discharges. However, there are no defined monitoring and control strategies for industrial discharges into the city’s sewage system, which have a significant and immediate impact on the Cauca River water’s quality and the performance of the WwTP-C. Water supply system: Due to the importance of water supply, different activities in order to improve the service and coverage as well as the protection, recovery and conservation of water sources are included in this component. However, minimization and prevention strategies, such as water reuse in households as an alternative water supply source that contributes to the adequate use of water, are not included.



Collection and conveyance of wastewater and stormwater: Strategies are focused towards the development of infrastructure works to carry more water to the WwTP-C, increasing sewage coverage and the development of plans for this purpose (i.e., Departmental Water Plan). The PSMV approaches this topic in a direct manner, proposing the following strategies: Building of infrastructure works to eliminate wastewater from the channels. In this

regard, the amount of wastewater arriving to the different drainage systems is thought to be reduced.

Operation and maintenance plans to improve current situation of deteriorated sewerage infrastructures to prevent for instance dragging of solids, floods, etc.

Control of wastewater discharges to the different drainage systems Recovery of landscape and green areas e.g. channels protection areas and Pondaje

lagoons. Education and awareness campaigns focused on the proper use of the drainage structures

and their importance for the community. Currently, the environmental educational campaign “recuperemos a canalito” or “let’s recover the channels” is taking place.

Establishment of control mechanisms to avoid presence of slums in the channels and in their protection areas.

As part of the plan, currently, there are infrastructures being built with the aim to contribute to improve Cauca River’s water quality. Such infrastructure works are: middle section of Cañaveralejo collector, replacement of Oriental interceptor and the “trasvase” works.

The PSMV formulated individual plans for each drainage system, estimating the future wastewater flows in the systems after the decontamination strategies. These works are planned to be undertaken in the short term, however the period of the plan is in the medium term (10 years). Table 7.3 shows the decontamination goals expressed as load and flow decrease in each drainage system. Such decrease in load was obtained as a result of considering decontamination works, landscape improvement works and maintenance and optimization in the sewerage structures as well.

Table 7.3 Estimated reduction in flows and BOD in each drainage system 2007-2016 Estimated load to be reduced in each drainage system

Subtotal to year 2011 (Kg/day)

Subtotal to year 2016 (Kg/day)

Total 2007-2016 (Kg/day)

Drainage Systems and rivers Flow (L/s)

BOD TSS BOD TSS BOD TSS South-Cañaveralejo, Lili, Melendez, and Cauca Rivers 1440 5702 6995 3629 4451 9331 11446

East – Cauca River 430 2758 2976 66 71 2824 3046 North-west – Aguacatal and Cauca River 915 12005 8640 407 293 12412 8933

Future urban area * 374 2586 1862 2485 1789 5072 3651 All systems 3159 23062 20473 6687 6804 29839 27077 Source :EMCALI, 2007 (*) Includes growth inside the present city



Wastewater treatment and disposal: Strategies proposed for wastewater management in the city of Cali have an “end of the pipe” approach. This strategy is adopted in the water quality objectives proposed by the local environmental authority. (DAGMA) and the regional environmental authority (CVC), as well as by EMCALI, the sewage service provider, through the proposal of the PSMV As it was mentioned in the Plan for sanitation and management of wastewater discharges, PSMV (EMCALI, 2007), proposed for the coming period 2007-2016 a gradual increment in the wastewater flow entering the WwTP-C so that its complete capacity will be fully achieved. Such flow estimations come as a result of the general decontamination plan followed in the drainage systems in the city during the next ten years (Table 7.4). Moreover, the plan estimates that in year 2016, the WwTP-C would reach an influent flow of 6,9 m3/s which corresponds to the 89,3% of its design flow (7,6 m3/s).

Table 7.4 Perspectives for total influent and effluent’s flows, and discharge loads from WwTP-C and WwTP-S as a result of the decontamination plan formulated in the PSMV.

Parameters 2006 2007 2010 2013 2016 WwTP-CAÑAVERALEJO, removal BOD 33% and TSS 56%

Influent loads BOD(kg/day) 69055 81544 92448 96389 98436 TSS (kg/day) 52904 62035 74049 78059 79795 Flow(l/s) 3810 4762 6269 6757 6950 Effluent loads BOD (kg/day) 54634 61875 64581 65952 TSS (kg/day) 27296 32463 34346 35110

WwTP-South, removal BOD 80% and TSS 85% Influent loads BOD(kg/day) 0 0 0 258 TSS (kg/day) 0 0 0 186 Flow(l/s) 0 0 0 19 Effluent loads BOD (kg/day) 52 TSS (kg/day) 28

Total removed by two treatment plants BOD(kg/day) 26910 30508 31808 32690 TSS (kg/day) 34739 41467 43713 44843 Flow (l/s) 3810 4762 6269 6757 6969

Source: EMCALI, 2007 Likewise, Table 7.4 presents the total flow and BOD load that will be transported to the WwTP-C. Likewise, DAGMA and CVC, the environmental authorities, propose the following decontamination goals: Wastewater flow entering the WwTP Cañaveralejo will increase from 3.35 m3/s to

6.47m3/s. Effective removal: 38% Removal of 80% of the contaminating load in 50% of the wastewater flow entering the

WwTP Cañaveralejo.



There are many differences between the objectives proposed by the environmental authorities, DAGMA and CVC, with respect to EMCALI’s goals, since according to the PSMV, the secondary treatment would not be carried out in 2016 considering EMCALI’s investment plan. Solid waste management: Strategies are oriented towards the implementation and follow up of the Integrated Solid Waste Management Plan, PGIRS, as well as the city’s debris control and follow-up. River Basin: The plans’ main strategy corresponds to the proposal and application of the planning and management of the Cauca, Pance, Lili, Meléndez, Cañaveralejo, Aguacatal and Cali River Basins and the recovery of the urban wetlands. This strategy has been implemented for approximately 10 years but with little progress achieved. In general, from the water urban cycle components point of view, strategies proposed by the institutions do not follow a water management framework plan for the city. Therefore, each component’s actions are isolated and in some cases, non-existent. 7.2.2 Studies of alternatives and Proposals Made in the Three Sectors of the City of

Cali Table 7.5 shows the main results of studies and proposals made in the three sectors, oriented towards the search of alternatives for water management and the strengthening of planning in the city of Cali. The scope of these studies depends on the implementation level of the proposed alternatives by the contracting institutions. Some of these are long term projects. These studies have been mainly contracted by EMCALI and DAPM through Universidad del Valle and consulting companies such as Ingesam, Gandini & Orozco, Hidroccidente, and others. A proposal made by PhD. Douglas Laing (independent consultant) for the management of wastewater in the Southern Drainage system that requires further studies to assess its implementation feasibility is also included. 7.2.2.1 Sector 1 Drainage area to WwTP-C Implementation of secondary treatment in WwTP-C EMCALI started in year 2005 the study of feasible alternatives for the upgrade of the WwTP-C to secondary treatment. In this regard, EMCALI and Universidad del Valle tested different aerobic alternatives at lab scale during year 2006. After lab scale studies one activated sludge system was selected to be implemented at pilot scale since it provided the best results during the lab experiments.



Table 7.5 Alternative studies and proposals of water management in the city of Cali Studies or proposal Source

Sector 1Drainage area of the WwTP-C Lab scale studies: Suspended growth (Activated sludge system): Extended

aeration; Contact stabilization; Adsorption / Bio-oxidation A/B; Conventional

Attached growth: Rotating biological contactor

EMCALI and Universidad del Valle, 2007

Pilot scale studies: Contact stabilization

EMCALI and Universidad del Valle, 2008a

Wastewater treatment plant WwTP-C

Re-use of the WwTP-C Effluent for agricultural purposes – irrigation of sugar cane crops.

EMCALI and Universidad del Valle, 2008b

Sector 2 South Drainage System Proposal Wastewater management of the South Canal

Anaerobic pond + constructed wetland + polishing ponds + irrigation of crops

Dr. Douglas Laing, PhD Biology

Sector 3 Expansion area Cali – Jamundí sector Drinking water supply

Prolongation of the Oriental transmission pipe TTO EMCALI and Hidroccidente S.A, 2006

Sewerage system Alternative 1: Separate system Alternative 2: Combined system Alternative 3: Separate and combined system Alternative 4: Separate and combined system

EMCALI and Hidroccidente S.A, 2006

WwTP-C Alternative 1 Pumping to WwTP-C


Wastewater treatment

WwTP-South Alternative 2: Conventional activated sludge system Alternative 3: UASB system plus low rate activated

sludge system Alternative 4: UASB system plus aerated lagoons


Sector 3 Expansion area Navarro sector Alternative 1. TTNV (Navarro transmission pipe) with direct supply from Puerto Mallarino plant.

EMCALI et al., 2006

Alternative 2. Autonomous system EMCALI et al., 2006

Drinking water supply

Alternative 4 Construction of 4 wells located along drinking water network.

EMCALI et al., 2006

Sewerage system Alternative 1: Sanitary sewers Alternative2: Combined sewer system

EMCALI et al., 2006

WwTP Navarro Alternative 1 UASB + aerated ponds + high rate settling

(WwTP-Navarro) Alternative 2 UASB + trickling filter + secondary settling

tank (WwTP-Navarro)

EMCALI et al., 2006 Wastewater treatment

WwTP-C Alternative 3 Conveying and pumping to WwTP-C

EMCALI et al., 2006

Basic studies developed in Navarro, the area with deferred regime (ARDN) Gradex (DAPM and Gradex Ltda, 2005) Ingesam (DAPM and Ingesam Ltda, 2005.) Hidroccidente (DAPM et al., 2005)

Lab scale studies: At lab scale, five aerobic systems were tested: Suspended growth (Activated sludge system): 1) Extended aeration; 2) Contact stabilization; 3) Adsorption / Bio-oxidation A/B; 4) Conventional and 5) Rotating biological contactor (Attached



growth). Table 7.6 show a summary of physical characteristics in the studied alternatives at lab scale for secondary treatment in WwTP-C (EMCALI and Universidad del Valle, 2008a)

Table 7.6 Summary of physical characteristics in the studied alternatives at lab scale for secondary treatment in WwTP-C

Suspended growth Attached growth Characteristics Extended

aeration Contact

stabilization Adsorption/

Bio-oxidation A/B Conventional Rotating biological contactor

Volume (l) 10 10

CR*: 3,5 SR**: 6,9

14,5 AR+: 2,5 BR++: 12

10 10

Phase 1: 5 l Phase 2: 5 l

HRT (hours) 30 -8 Total: 13,1-2,5

CR: 3,3-0,5 SR: 9,8-2

Total : 34-5,8 AR: 4-1

BR: 27,3-4,8 8-2 22-0,8

Source: EMCALI and Universidad del Valle, 2008a Notes: *CR: contact reactor, **SR: Stabilization reactor, + AR: Adsorption reactor, ++ BR: Bio-oxidation reactor

Table 7.7 shows the summary of the removal efficiencies from each studied alternative, showing that all systems reached BOD and TSS efficiencies higher than 80% in the settled wastewater and in this way the systems were complying with the national standards stated in Decree 1594-1984. The substrate influent wastewater to the systems was the influent to the grit removal chambers without any addition of chemicals followed by a simulated conventional settling in a 1 m3 tank with HRT of 2 hours (like in the full scale settling tanks).In the inoculated sludge for the activated sludge system a concentration of MLSS of 3100 mg/l was guaranteed.

Table 7.7 Summary results of each alternative in terms of effluent quality and removal efficiencies

Effluent (mg/l) Removal efficiency (%) System HRT (hour) BOD COD TSS BOD COD TSS

Extended aeration 12-16 <3 <29 <4 98-99 88-94 96-99 Contact stabilization 3,5-5 <16 <42 <15 90-92 77-90 86-90 A/B system 5,8-8,7 <11 <50 <3 92-97 80-95 95-99 Conventional Activated Sludge 4-6 <21 <38 <3 88-96 89-98 96-99 Rotating biological contactor 2-4 <12 <51 <16 95-96 80-88 87-96 Source: EMCALI and Universidad del Valle, 2007 Notes: HRT: Hydraulic retention time

Full Scale C-WwTP influent (average): BOD 238 mg/L, COD 490mg/L; TSS 194 mg/L Lab scale influent (average): BOD 164 mg/L, COD 286 mg/L; TSS 81 mg/L

According to EMCALI and Universidad del Valle (2007), extended aeration was more robust to sudden increments of organic load but used long HRT. Contact stabilization used low HRT and required the least space among all technologies. However due to the high production of sludge a more robust sludge system should be considered in the plant. A/B system presented similar behaviour to extended aeration with additional enhancement of nitrification processes in the BR reactor. However it would need extra settling line between both reactors and higher space requirements. Conventional Activated sludge presented similar trends to extended aeration but al lower HRT. Rotating biological contactor is vulnerable to external factors like lack of energy to rotate discs or high grease loads that could break down the bio-film. Hence, the technologies of contact stabilization and



conventional activated sludge were the ones chosen to be implemented at pilot scale. Both technologies operated at low HRT and presented less complexity in operation. Pilot scale studies: This research project made a pilot scale evaluation of two activated sludge system modalities: stabilization by contact and conventional activated sludge, as secondary options for the effluent treatment at the wastewater treatment plant of Cañaveralejo (WwTP-C).

The study was developed based on the results obtained at laboratory scale in Phases I and II of the project, where the modalities of activated sludge by contact stabilization and conventional activated sludge were evaluated. The sludge for the pilot plant was taken and inoculated from sludge from the secondary settling tanks from the WwTP-Aguas del sur, located in the Caney neighbourhood in Cali which uses activated sludge system.

Figure 7.2 Pilot plant located in the WwTP-C Source: Universidad del Valle and EMCALI, 2008a

Figures 7.3 and 7.4 show the process schemes used in the pilot scale evaluation.

Grit separatorSands

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Aeration tank Scheme process Figure 7.3 Pilot plant of the contact stabilization

Source: EMCALI and Universidad del Valle, 2008a



Conv

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Aeration tank Scheme process Figure 7.4 Pilot plant of the conventional activated sludge

Source: EMCALI and Universidad del Valle, 2008a The pilot plant has been ran in phases varying the influent flow until it reaches the design flow of 0,66 l/s and varying the re-circulated sludge. Table 7.8 shows a summary of the results from the operation phases of the pilot plant.

Table 7.8 Effluent quality and removal efficiencies in the pilot scale plant contact

stabilization Removal efficiencies (%) Effluent quality (mg/l)

Phase Influent (l/s) Recycled Sludge (%) HRT

BO D COD TSS BO D COD TSS 100 - - - - - -

Beginning 0,18 25%Qdesign 130

3,1 - - - - - -

100 84 91 96 28 29 8 85 89 93 97 17 24 1 1 0,33

50%Qdesign 70

1,7 82 91 99 29 31 1

85 87 90 84 26 31 10 70 85 92 92 33 30 5 2 0,50

75%Qdesign 55

1,1 83 90 86 31 32 10

40 83 87 94 52 35 5 3 0,66

100%Qdesign 55 0,8

81 77 80 46 78 17 4 0,56 55 1 83 91 87 41 29 12

Source: -Adapted from EMCALI and Universidad del Valle, 2007 According to EMCALI and Universidad del Valle (2007) the most stable operation condition was in phase 2 with a recycle flow of 55%. Moreover, in general it has been seen that the contact stabilization system can achieve BOD, COD and TSS removal efficiencies higher than 80% According to EMCALI-Universidad del Valle (2008) the main results were: The stabilization by contact activated sludge and conventional sludge have the potential for the treatment of the clarified effluent of the WwTP-C. The evaluation of the system at pilot



scale showed one of the main advantages of the stabilization by contact vs. the conventional sludge is the capacity to remove larger organic matter loads. Its configuration allows treating higher wastewater flows, which results in the higher amount of load removed by the system. However, it is important to consider that this efficiency is reflected in the active sludge generation that has to be treated and disposed, which is fundamental for the decision of the implementation of one of these modalities. Table 7.9 shows the performance results of the two pilot systems in terms of COD and TSS loads. Effluent quality under stable operating conditions was very similar. Table 7.9 Operational loads of the pilot activated sludge systems: contact stabilization and

conventional Influent (mg/L)

Effluent (mg/L)

Influent load (g/d)

Effluent load (g/d)

Removed load (g/d) System

COD TSS COD TSS COD TSS COD TSS COD TSS

Contact stabilization (F = 57024 L/d) 330 84 78 17 18819 4790 4448 912 14371 3878

Activated sludge conventional (F= 29386 L/d) 269 71 40 5 7905 2086 1175 147 6730 1939

Source: EMCALI and Universidad del Valle, 2008a The stabilization by contact mode removed a larger load of organic matter in less time, which is reflected in lower treatment volume requirements. However, it is important to consider that the operation complexity level is also higher. According to the pre-dimensioning made for the WwTP-C design flow of 7.6m3/s, the area required for both modalities (stabilization by contact and conventional) ranges from 3.00 ha to 4.38 ha respectively (Table 7.10). According to EMCALI, the area available at the WwTP-C for the secondary treatment is 11.3 Ha. This area would be sufficient for the implementation of either one of the studied modalities (EMCALI and Universidad del Valle, 2008a)

Table 7.10 Global requirements and useful area for the treatment Global Requirements Contact stabilization Conventional

Activated sludge Characteristics CR RE SS AT SS*

Contact stabilization

Conventional Activated sludge

HRTnet (h) 0.84 4.11 3.00 5.00 3.00 4.95 5.00 Fdesign (m3/s) 7.60 3.04 7.60 7.60 7.60 7.60 7.60 Flowreactor (m3/s) 3.04 5.32 - - Total volume (m3) 22982 44980 82080 136800 82080 67962 136800 Global area (m2) 4596 8996 16416 27360 16416 30008 43776 Global area (ha) 0.46 0.90 1.64 2.74 1.64 3.00 4.38 CR: Contact reactor SR: Stabilization Reactor SS: Secondary settler AR: Aeration tank HRT neto: only the influent flow in considering in the estimation of the HRT (V/ F) Secondary sedimentation is including in the global area Source: EMCALI and Universidad del Valle, 2008a

Study of the evaluation of the potential re-use of the WwTP-C Effluent for agricultural purposes



This investigation for EMCALI was made by Universidad del Valle under the UNIVALLE – EMCALI agreement. Its purpose was to evaluate the feasibility of the WwTP-C effluent reuse for agricultural purposes under the current operation modalities: with TPA (Advanced Primary Treatment) and without TPA. The study evaluated the potential use of the WwTP-C effluent for agricultural purposes, considering its physical-chemical characteristics and microbiologic quality, as well as the possible impact on the microbiological quality of soils. Additionally, an estimate of the preliminary costs associated with the conduction of the treated effluent to the sugar cane plantations in the zones located in front of the discharge site of the effluent into the WwTP-C was made (EMCALI and Universidad del Valle, 2008b) This research was divided into three stages: 1) Experimental phase: The evaluation of the potential agricultural reuse of three different water qualities: WwTP-C effluent with TPA, effluent without TPA and well water. 2) Evaluation of two different effluent transfer alternatives: Crossing of the effluent through a viaduct, and b) Crossing of the effluent through a through an inverted siphon. 3) Pre-design of the wastewater distribution system for the sugar cane sector: A water supply and demand study is carried out during this phase. According to Universidad del Valle and EMCALI (2008b), the main results were: The three evaluated water qualities, (well water, WwTP-C effluent treated with and without TPA), show that from an agronomical point of view, these waters do not have a restriction for agricultural use because the electrical conductivity values, boron and nitrites are under the FAO’s allowed limits (1985). With respect to the conductivity and the RAS, they are classified as Class C2S1 water by the Department of Agriculture of the United States, without use restrictions due to these variables. Additionally, the heavy metals analysis showed that the three water qualities studied show values under those established by the EPA (1992) for agricultural irrigation. From the microbiological point of view, and considering the possibility of treating the wastewater, the results showed water use restrictions due to high total coliform values (4.6 x 107 with TPA and 2 x 107 without TPA), E. Coli (1.4 x 107 with TPA and 7.1 x 106

without TPA), and helminths eggs (27.6 with TPA and 22.06 without TPA), according to WHO quality standards (2006) for irrigation. This creates the need for the implementation of protection measures for workers having contact with the plant (WHO, 1985; EPA, 1992 and WHO 2006 as cited in EMCALI and Universidad del Valle, 2008b). In relation to the effluent’s transfer to the sugar cane crops located on the right margin of the Cauca River, based on the pre-design, it was defined that the best effluent transfer alternative is through a viaduct (hanging bridge), which would pump the water by means of a screw pump. The approximate cost of the selected alternative is US$ 584,000 (Col.Ps. $1,115,174,990)



For the design of the distribution system, a group of professionals from EMCALI agreed on a WwTP-C supply flow of 1.0 m3/s, which would allow for the extrapolation of the results according to the volume. The potential irrigation area was estimated at 592.5 ha. Two design options were proposed: Option 1, which considered the simple function and individual storage; Option 2, which considered a double function (reception and storage) and the connection of the lots through the existing distribution boxes. From an economical point of view, the implementation of Option 2 is more convenient, with an approximate cost of US$151,000 (Col. Ps. $ 288,075,000). The total estimated cost of the transfer and the distribution system of 1.0 m3/s of the WwTP-C’s effluent for the irrigation of the sugar cane crops located in the discharge area is US$735,000 (Col.Ps. $1,403,249,992) Following are the final recommendations of the study (Universidad del Valle and EMCALI, 2008b): Carry out an investigation that allows evaluating on a greater scale cultivated field (0.5

Ha) the effects of the WwTP-C’s water over the relevant agricultural use parameters (salinity, modicity and toxicity).

Make a detailed topographic survey of the interest area to make an accurate calculation of the flow distribution network where the water is distributed to the lots.

The participation and support of the participating farmers and stakeholders is recommended. This will allow having better access to the information and the generation of an organizational structure focused towards the optimum use of water and the operation, maintenance and management of the system.

7.2.2.2 Sector 2 South drainage system Wastewater management of the South Channel This proposal was conceived by Dr. Douglas Laing, PhD Biology. The purpose of his proposal is to facilitate recovery of the channels in the system and contribute to decreasing the impact on the Cauca River, which is the main source of water supply to Cali. This proposal considers the separation of waste and stormwaters, the recovery and maintenance of the stormwater channels and the management of agricultural land located on the right margin of the Cauca River, for the implementation of biological wastewater treatment in ponds and surface flow wetlands that work with native species forests. In light of the above mentioned considerations, this proposal would be completed in the seven following stages: 1. Collecting and using gravity (where possible) to carry wastewater from Cali’s Southern

area to Stage 4. 2. Control gates and final sand trap at the mouth of the South channel for wastewater in

the last stretch (after the highway).



3. Pumping wastewater from the last stretch of the South Channel through the Cauca River to the anaerobic ponds in Stage 4.

4. Primary treatment in anaerobic ponds. 5. Secondary treatment in constructed wetlands (FSW-type). 6. Tertiary treatment in polishing ponds. 7. Use of treated water for irrigation purposes and/or for returning into the river. Additional studies oriented towards the evaluation of the implementation feasibility, wastewater treatability, dimensioning of treatment units, pumping and conduction structures, environmental impact, and cost/benefit estimates considering the reuse of wastewater for sugar cane crop irrigation (supply and demand studies), among others. 7.2.2.3 Sector 3 Expansion area Two important studies for public service planning alternatives have been developed for the future expansion area of Cali, the Cali- Jamundí Corridor and Navarro. Both are long term studies (2010 – 2030). A more detailed description of these two proposals was provided in the Diagnose Report, Chapter 8, made within the SWITCH Project (Universidad del Valle, 2008). Presently the bid and development of a new pre-feasibility study for the supply and sanitation of this zone is underway, considering the environmental vision for the development of the Navarro eco-city, since this is a complex system with diverse environmental variables to be included. The goal is that this new study responds to the environmental expectations of the general project. Expansion area Cali-Jamundí: EMCALI in 2005 hired the consultancy firm Hidrooccidente to make the feasibility studies for the delivery drinking water and sanitation services in this expansion sector. Therefore, all the information described in the section Cali-Jamundí corresponds to the study carried out by EMCALI and Hidrooccidente S.A. (2006). Following is a synthesis of the results obtained by the consulting firm that developed the pre-feasibility study. Drinking water supply - Prolongation of the oriental transmission pipe TTO For the analysis of the population density and drinking water provision, an amount ranging between 200 and 340 L/inhab/day according to the socio-economic strata. This study was 1067 L/s. Water supply would be done through the expansion of the matrix network south of Cali, which would supply the sector by gravity and another one by re-pumping, feeding two storage reservoirs. It was already defined that the TTO would supply the Cali Jamundí sector with a flow of 510 L/s. The system would be strengthened with the installation of a new pipeline brought from Puerto Mallarino, which would reach the Navarro Sector. This pipeline would be called Navarro Transmission Pipeline. Figure 7.5 shows a scheme of this proposal



EXTENSIÓN TTS

CJ-4

ÁREAS ATENDIDAS

CJ-9

JH-04

Tanque CRA 127(Cota 1030 CMT)

DESVIO TTO

622,63 Ha

412,08 Ha

323,29 Ha

TTS - TTO

TANQUE CRA 118

TANQUE CRA 127

EXTENSIÓN TTO

Vía Pu

erto T

ejada

Carrera 120

Calle 42

Canal su

rCarrera 130

Carrera 126

Carrera 109

Carrera 73

Carre ra 80

Carrera 83C

Carrera 86

Carrera 94

Carrera 98

Carrera 99

Carrera 109

Carrera 115

Carrera 118

Carrera 122

Carrera 1 26

Carrera 128

Carrera 134

Carrera 143

Carre

ra 1

41

Carrera 127

Carrera 125

Carrera 122

Carrera 118

Carrera 100Calle 16

Avenida Cañasgordas

Calle 20

Calle 25

Calle 36

Calle 60

Calle 48

Carrera

50

Calle 54Calle 42

Calle 25

Río LILICalle 53

Calle 48

Río LILI

Carrera 102

Tanque CRA 118(Cota 1030 CMT)

CJ-1

CJ-2CJ-3

CJ-5

Calle 61

CJ-8

CJ-6

PUNTO DE EMPALME PROLONCAGIÓN TTS - TTO

Figure 7.5 Proposed drinking water layout and supply zones in the sector Cali Jamundí

Source Emcali and Hidroccidente, 2006 Sewage system For this study, the wastewater production by 2030 was estimated between 170 L/per/day to 272 L/per/day. The Cali-Jamundí area was divided in four drainage sectors according to the sewage system. These sectors were named Sector 1, 1A, 2 and 3 (Figure 7.6) Four alternatives were analyzed for this zone, including the combined or individual sewage system options for the four sectors (Annex 3). In its final recommendations the firm Hidro-occidente stated the following: The most appropriate option should include separate sewerage system in sectors 1 and 1A which would drain by gravity their wastewater to the WwTP-C to take advantage of its total capacity. Sector 2 presents risk of flooding. If the system is separate there is the need of pumping 47% of the rainwater that falls in the drainage area and if the system is combined 100% of the rain water needs to be pumped. Therefore it is suggested the implementation of a separate system in that sector. Sector 3 presents 87 ha which are under flood risk as well (nearby Sur wastewater pumping station). Hence a separate system must be implemented in this sector as well.

SUPPLY ZONES

TTS-TTO 622,63 Ha TANK “Cra 118” 412,08 Ha TANK “Cra 127” 323,29 Ha



CaliCaliUrbanUrban AreaArea




Figure 7.6 Proposed drainage sector in the Cali-Jamundí sector

Source Emcali and Hidroccidente, 2006 Wastewater treatment The selected alternatives proposed by EMCALI and Hidro-occidente (2006) for the treatment of the wastewater generated in the area Corredor Cali- Jamundí was (Annex 3 included the main characteristics of the alternatives): Alternative 1: Pumping to WwTP-C Alternative 2: Conventional activated sludge system Alternative 3: UASB system plus low rate activated sludge system Alternative 4: UASB system plus aerated lagoons The alternatives 2, 3 and 4 refer to the proposed wastewater treatment plant in the sector Cali-Jamundí called WwTP-Sur. The influent wastewater to the WwTP-C in year 2030 was estimated to be 7,28 m3/s which made feasible to consider alternative 1. Hidrooccidente firm recommended the alternative 1 (Pumping to WwTP-C) to the expansion area Cali-Jamundí wastewater management according with technical, economic, and environmental results. Expansion area Navarro: Navarro Expansion Area: Cali’s POT established the Navarro sector as a deferred regime area; in other words, as a zone in which future urban expansions



may be proposed after performing studies and tasks that allow the urbanization and that prove the mitigation of diverse risks. In 2005, the Municipal Planning Administrative Department (DAPM), hired four studies with private consulting firms and performed the seismic micro-zoning in an agreement between DAGMA and INGEOMINAS, in order to know the zone’s characteristics and later on propose as Urban Expansion Soil the zone called Navarro Deferred Regime Area (ARDN) in the Territorial Order Plan. Annex 4 shows a summary of the most relevant studies executed: Study of the environmental impact of the Navarro Dump Inventory and characterization of the wetlands Hydrogeology study Flood threat study Seismic Micro-zoning

The Ministry of the Environment and Housing, in Resolution 1463 of 2008, approved the macro-project of national interest, Navarro Eco-City, which corresponds to the ARDN1intervention. National social interest macro-projects are a set of administrative decisions and integrated urban actions for the management and provision of housing soil, with special emphasis on social and priority interest housing, adopted by the National Government, in which planning, financing and soil management are involved to execute a large scale operation that contributes to territorial development in certain municipalities, districts, metropolitan areas or regions of the country2. The goal of the Navarro Eco-City is to decrease the quantitative housing deficit by developing a high percentage of social and priority interest housing. The Municipal Housing Secretariat presented a report in which the main characteristics of the zone and the urbanization and development expectations are shown. The goal of the macro-projects is to develop an Eco-City having in mind the technical conditions for the execution of the Macro-Project, providing adequate conditions for the implementation of a sustainable housing program, working as an essential component the environmental aspects, as well as the presence of wetlands, water sources and aquifers. The studies mention the necessary and priority programs and projects to minimize the negative impact over the inhabitants occupying this area in favour of decreasing community and environmental risks. These risks conserve their potential characteristics, and decreasing the risks will depend on the effective execution of the proposals and their success. On the other hand, in 2005 EMCALI hired the companies Gandini and Orozco and Contelac Ltda. in order to study alternatives for water supply, collection, transportation and

1 Official Journal. Colombian National Printer. Bogotá D.C. Tuesday, August 26, 2008. 2 Decree 4260 of 2007.



disposal of storm and wastewater, as well as wastewater treatment for the Navarro Deferred Regime, selecting the best alternative for the public services provision in the mentioned area, considering the economic, social, and environmental aspects. Annex 3 includes the main characteristics of the Navarro sector taken from the Diagnose report of the SWITCH Project (Universidad del Valle, 2008). Following is a summary of the study results. Drinking water supply An amount of 187 L/inhab/day and an average flow of 666 L/s were considered in the water supply alternatives for the Navarro expansion zone. Table 7.11 shows the alternatives that consider the supply sources and the corresponding treatment systems.

Table 7.11 Summary of proposed drinking water alternatives Alternative Description

Parallel to TTO line. It is feed by Puerto Mallarino plant 1. TTNV (Navarro transmission pipe) with direct supply from Puerto Mallarino plant.

This alternative causes high energy costs due to pumping through long distances from Puerto Mallarino until Navarro sector New drinking water plant located in Navarro sector using Cauca river as water source upstream South channel. The drinking plant would be composed by, grit removal chambers, settling tanks, rapid filters and chlorination.

2. Autonomous system

The sector of Navarro would be supplied through pumping. Each well would have its own water treatment system and pumping system. The hydraulic capacity of each well would be 200 l/s

3. Construction of 4 wells located along drinking water network. Wells’ depths would be more than 400 meters. The water treatment would consist of: biological reactor,

aeration, rapid filters and chlorination Source: Adapted from: EMCALI et al., 2006 Sewage system For the sewage system design, a return flow was established as 0.85 of the drinking water consumption. The design flow for the pre-design of the sewerage network was assumed at 1,5 L/s. The storm water flows were estimated using the model EPA-SWMM-V-5.0. The following were the considered parameters for the proposed design of the sewerage systems: - Average Flow= 423,52 L/s - Infiltration Flow = 110-7 L/s - Illegal connections flow = 61,50 L/s - Maximum hourly flow = 669,48 L/s - Rain flow = 46288,65 L/s Options considered according to the discharge site and the type of sewage are the following:



Individual sewage: - Stormwater into the Cauca River - Wastewater into the WwTP Cañaveralejo - Wastewater into the Navarro WwTP

Combined sewage: - Stormwater into the Cauca River - Wastewater into the WwTP Cañaveralejo - Wastewater into the Navarro WwTP

The consultancy firm left the decision of the preferred alternative to EMCALI. Wastewater treatment Alternatives proposal consider an average wastewater flow of 300 L/s (156000 inhabitants forecast to 2030, BOD 200 mg/L, COD= 380 mg/L; return coefficient=0.85; 140 L/inhab/day). The selected alternatives proposed by Gandini & Orozco, (2006) for the treatment of the wastewater generated in the Navarro area were: WwTP Navarro Alternative 1 UASB + aerated ponds + high rate settling (WwTP-Navarro) Alternative 2 UASB + trickling filter + secondary settling tank (WwTP-Navarro)

WwTP-C Alternative 3 Conveying and pumping to WwTP-C. Transportation of wastewater by

gravity to the Aguablanca pumping station and later pumping to the WwTP-C The study made use of an economical assessment in order to classify the technologies according to their investment, operation and maintenance costs. From such classification, the least costly option was alternative 3, followed by Alternative 1 and afterwards Alternative 2. Moreover, between alternative 1 and 2, the less expensive alternative was number 1: UASB + aerated pond + high rate settling. The effluent final discharge from the WwTP-Navarro would be Cauca River in case its construction is finally decided. Disinfection would be applied to the effluent before it is discharged to Cauca river 7.3 PROPOSAL OF STRATEGIES IN THE SHIFT PARADIGM FRAMEWORK As mentioned in the general review, this item presents different water management alternatives using the SWITCH Project philosophy. The presentation of alternatives is done through a series of matrixes for each study zone considering their own characteristics, in which the different technological, institutional, normative and economic actions are mentioned in the components of the water cycles affecting the city areas. The master plan for the city of Cali results from the articulation of the tactics proposed for each study zone. These practices are a set of simultaneous activities to be executed in a combined manner during the different time intervals. Each activity would be performed during an estimated time with a certain degree of uncertainty. Related to this uncertainty, and depending of the effective execution of these



activities, the feasibility of having longer terms would be established. Therefore, tasks are more defined at times presenting a lower uncertainty. As the different terms are reached, other tasks would emerge as a result of the new expectations, technological developments and the achievements made to the date, generating new matrixes, giving continuity to the proposed actions and with the emerging of new tasks oriented towards compliance with the vision that had been presented for the study zones. What today is shown as long term, in the future will be medium term and later on, short term. Figure 7.7 shows a scheme of this interaction.

Figure 7.7 Scheme of interactions between activities proposed vs time

Time

Sh

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Present



7.3.1 Sector 1 Drainage area to WwTP-C

Table 7.12 Proposal of short, medium and long term actions in “Household” component. Sector 1: Drainage area to WwTP-C

Technical Aspects Institutional aspects Economic tools Policies and regulations Reduction of water consumption Water loss control in the household Participation in training programs about water use efficiency,

minimization and prevention Replacement and use of low water consumption devices. Reduction of basic consumption (l/inhab/d)

Education campaigns and

socialization programs about water use efficiency

Economic incentives for

encourage water consumption reduction

Gradual adjustment of the basic charges tariff

Gradual adjustment of the

basic charges tariff

Greywater management Voluntary reuse of grey waters at household level (washing

machine, showers). Implementation of simple grey water collection systems.



Estimation of investment

and O&M cost

Quality standards for the

use of storm waters.

Shor

t ter

m

Stormwater management Characterization of household water uses. Storm water supply and demand study by city sectors. Stormwater characterization (quality and quantity) and

identification of potential uses Characterization and selection of storm water capture, storage

and distribution technologies. Investigation of the design parameters of the hydraulic and

sanitary installations for the use of storm water. Predesign of technologies for the use of storm waters (capture +

pumping + storage + treatment)

Interinstitutional

participation in household planning (public services companies, urbanization developers, environmental authority, municipal government and community)

Promotion of the sustainability culture and environmental education.


and O&M cost Economic and financial

feasibility studies

Technical standards for the

construction of households using new water management trends.

Reduction of water consumption Participation in training programs about water use efficiency,

minimization and prevention Replacement and use of low water consumption devices. Reduction of basic consumption (l/inhab/d)

Water loss control Education campaigns and




Tariff’s study and re-

adjustment.

Stormwater management Design and implementation of stormwater systems (captation,

pumping, storage, treatment, distribution) Participation in training programs about the efficient use of water

and the use of new technologies.

Interinstitutional

participation in household planning

Evaluation and

Internalization of Externalities


construction of households using new water management trends. M

ediu

m te

rm

Greywater management Implementation of grey water re-circulation systems in new

urbanizations and households. Modification of the existing hydraulic and sanitary facilities

considering the new trends for household water management.

Economic and financial

feasibility studies





Table 7.12 Proposal of short, medium and long term actions in “Household” component. Sector 1: Drainage area to WwTP-C (cont.)

Technical Aspects Institutional aspects Economic tools Policies and regulations

Med

ium

term

(c

ont.)

Dry sanitation Characterization of dry sanitation technologies and its social and

cultural acceptance. Feasibility studies of dry sanitation systems Investigation of the design parameters of the hydraulic and

sanitary installations for dry sanitation (urine and feces) Pilot scale study and demonstration projects Predesign of technologies for dry sanitation.


socialization programs about dry sanitation systems

Interinstitutional participation in household planning


and O&M cost of dry sanitation systems

Cost-benefit analysis

Reduction of water consumption Use of drinking water exclusively for basic needs (consumption,

food preparation, personal hygiene)

Soft credits for the

implementation of dry sanitation technologies.

Issuance of technical standards for house construction according to the new water management trends

Long

term

Dry sanitation Acquisition and installation of separation of urine and excreta

devices (dry sanitation) Adequacy of water and sanitation facilities for dry sanitation

systems Implementation of hydraulic and sanitation facilities for new

housing constructions.

Dry sanitation systems usage training

Interinstitutional participation in household planning.

Table 7.13 Proposal of short, medium and long term actions in “Industry” component. Sector 1: Drainage area to WwTP-C


Shor

t ter

m

Pollution prevention and control Update and inventory of the industries discharging waste in the

WwTP-C drainage area. Identification and geo-reference of discharge sites Monitoring and follow up of the quality of the water discharged

into the sewage system. Update and collection of data on historically discharged load. Characterization of the industrial production processes and

identification of the characteristics of wastewater that affects the WwTP-C processes

Planning CP alternatives to be applied to processes using and generating wastewater.

Preliminary technology selection of CP Environmental and technical assessment

Dissemination of the CP

concept and promote its adoption in the productive sector, with environmental authorities and the general community.

Dissemination of CP information, healthy environmental technologies, Colombian environmental legislation and options to support the implementation of CP in the industry.

Estimate cost-benefit ratio

generated by the increase in process efficiency, savings in the consumption of raw materials and energy, and the decrease of waste and contaminating emissions.

Regulation of tax incentives according to Law 223/95

Issuance of standards for

the prevention of contamination, promoting technological innovation, the search of more efficient and effective environmental and economic solutions.

Definition of follow-up and evaluation mechanisms for the agreements made between the environmental authority and the productive sector.



Table 7.13 Proposal of short, medium and long term actions in “Industry” component. Sector 1: Drainage area to WwTP-C (cont.)


Shor

t ter

m (c

ont.)

Assessment of the technical feasibility and economic viability for cleaner production activities

Selection of feasible alternatives to implement the CP program. Program for the implementation of CP policies in agreement with

the productive sector and competent environmental authority, setting environmental quality goals.

Optimization of processes Implementation of the Cleaner Production program. Setting of follow up and evaluation indicators Evaluation and follow up of the CP program implementation

Planning, action coordination and criteria and methodology standardization and CP implementation management.

Strengthening of the institutional capacity for the implementation of environmental policies, training, monitoring and follow-up and communication channels for the dissemination of results and experiences

Creation of economic and financial resources incentive mechanisms to support CP implementation and co-funding of projects in the productive sectors.

Overprice of materials and products with high contamination indexes and have a less contaminating alternative, used in the productive processes

Set clear environmental goals for the productive sectors.

Establish limits in the different categories and types of substances produced and discharged in the sewage system, depending on the type of industry, contaminating load, environmental quality and receptor source’s quality.

Med

ium

term

Pollution prevention and control Monitoring and follow up of the quality of the water discharged

into the sewage system. Follow up and control of the CP program.

Life cycle assessment Definition of objectives and application Life cycle inventory analysis: mass balances Environmental impact and risk assessment Environmental risk management. Comparative risk analysis Economic impact assessments

Strengthening of the

communication channels and dissemination of CP information, healthy environmental technologies, Colombian environmental legislation and options to support the implementation of CP in the industry.

Long

term

Pollution prevention and control Total implementation of the CP program for the elimination of

industrial discharges into the WwTP-C drainage area. Follow up and control of the CP program.

Dissemination of CP

information, healthy environmental technologies, Colombian environmental legislation and options to support the implementation of CP in the industry.



Table 7.14 Proposal of short, medium and long term actions in “Water supply system” component. Sector 1: Drainage area to WwTP-C

Technical Aspects Institutional aspects Economic tools Policies and regulations Minimization and pollution prevention Minimization of wastewater production in the housing - water

use efficiency - Promote the culture of water efficient use and conservation.

Greywater and stormwater reuse





Estimation of investment and O&M cost

Pollution control of the water supply – Cali River Protection of the supplying basin (domestic and agricultural

discharge control, control and relocation of settlements, reforesting).

Pollution control upstream to water intake of Puerto Mallarino (domestic, industrial, agricultural wastewater discharges)

Control of industrial discharges into the drainage system (CP program and pollution control goals)

Proposal and

implementation of the POMCH

Development of education campaigns to incentive the culture for the efficient use and saving of water in the community.

Stimulate lower

consumption through tariffs.

Soft credits of the implementation of low consumption devices.

Setting of environmental

goals and objectives for the control of sanitary interest substance emissions.

Shor

t ter

m

Water treatment, distribution and storage Water loss control in water distribution systems and storage tank Optimization of water distribution networks Optimization of water treatment processes Operation, maintenance and replacement of distribution system

elements.

Pollution prevention Promote the culture of water efficient use and conservation. Greywater and stormwater reuse Characterization of technologies to use rainwater and greywater

as an alternative water source (captation, pumping, storage, treatment, distribution)

Definition of design parameters (rain water captation, storage and distribution )

Implementation of pilot scale study and demonstration projects



Stimulate lower


Economic incentives for encourage water consumption reduction




Med

ium

term

Pollution control of the water supply - Cauca River Protection of the supplying basin (domestic and agricultural discharge control, control and relocation of settlements, reforesting).

Protection of the Cauca River tributaries. Pollution control upstream to water intake of Puerto Mallarino (domestic, industrial, agricultural wastewater discharges) Follow up and control of industrial discharges in the sewage system (compliance with decontamination goals).

Follow up and control of the POMCH implementation.

Interinstitutional coordination for decontamination goals according to the Cauca River water quality.

Stimulate lower consumption through tariffs.


Economic and financial feasibility studies

Control of the use of agro-chemical products in the industrial sector.



Table 7.14 Proposal of short, medium and long term actions in “Water supply system” component. Sector 1: Drainage area to WwTP-C (cont.)

Technical aspects Institutional aspects Economic tools Policies and regulations Pollution control of the water supply - Cauca River Protection of the supplying basin (domestic and agricultural discharge control, control and relocation of settlements, reforesting).

Protection of the Cauca River tributaries. Pollution control upstream to water intake of Puerto Mallarino (domestic, industrial, agricultural wastewater discharges) Follow up and control of industrial discharges in the sewage system (compliance with decontamination goals).

Follow up and control of the POMCH implementation.






Med

ium

term

(con

t.)

Water treatment, distribution and storage Water loss control in water distribution systems and storage tank Optimization of water distribution networks Optimization of water treatment processes Operation, maintenance and replacement of distribution system elements.

Long

term

Continuity, follow-up and control of short and medium term implemented actions.

Table 7.15 Proposal of short, medium and long term actions in “wastewater collection” component. Sector 1: Drainage area to

WwTP-C

Technical aspects Institutional aspects Economic tools Policies and regulations Data from sewerage systems Monitoring programmed and final discharges characterization Topographic survey and data systems. Sewage system data systems (real time or programmed monitoring). Characterization of technologies for sewerage system modelling Selection of the hydroinformatics tool. Wastewater sewerage modelling Construction of sewage operation scenarios.

Participation of the institutions that generate useful information for the sewage system operation.

Estimation of investment and O&M cost of the sewer system automation

Shor

t ter

m

Operation and maintenance of sewerage system Identification of the status of sewage system components. Reposition and maintenance of structures (canals, separation

structures and solid separation structures)



Table 7.15 Proposal of short, medium and long term actions in “wastewater collection” component. Sector 1: Drainage area to WwTP-C (cont.)

Technical aspects Institutional aspects Economic tools Policies and regulations Real time control of the sewerage system Monitoring programmed and final discharges characterization Identification of sewage system monitoring stations (pluviometric, climatologic)

Characterization of technologies for sewerage system monitoring Definition of monitoring parameters and sampling frequency Selection of monitoring technologies (equipment, data transmission systems, sensors)

Monitoring network design Design of an early warning system - EWS (monitoring parameters, stations design, equipment and sensors, others)

Participation of the institutions that generate useful information for the sewage system operation. .

Strengthening the decision-making participation of the different productive sectors

Monitoring programmed Selection of sewage surveillance and control monitoring sites. Definition of monitoring parameters and sampling frequency Inventory and characterization of the industrial discharges. Monitoring programmed and final discharges characterization

Shor

t ter

m (c

ont.)

Control of wastewater discharges Minimization of wastewater production in the household - water use efficiency.

Wastewater production planning according to new wastewater management trends.

Follow up and control of industrial discharges, solid waste and debris into the sewage system

Characterization of wastewater quality and quantity Setting indicators for the control and follow-up of discharges into the sewage system.



Active participation of the industry in the planning and compliance of goals for the elimination of waste water discharges.



Adjust tariff standards and

methodologies according to the new wastewater management trends.

Data from sewerage systems Database updating Construction of system operation scenarios. Performance forecast and sewage system planning (design

specifications).

Med

ium

term

Real time control of the sewerage system Implementation of real time monitoring network within sewage system

Systematic monitoring of the sewage network Implementation of the system control structures (gates, valves, storage) migrating from a static to a dynamic system.

Operation and maintenance of the real time monitoring network

Participation of the

institutions that generate useful information for the sewage system operation.



Table 7.15 Proposal of short, medium and long term actions in “wastewater collection” component. Sector 1: Drainage area to WwTP-C (cont.)

Technical aspects Institutional aspects Economic tools Policies and regulations New technologies for wastewater collection and transportation. Characterization of innovative wastewater collection and convey technologies

Wastewater production planning according to new wastewater management trends.

Feasibility studies and implementation of innovative technologies Development of demonstration projects Implementation of demonstration projects using innovative technologies.

Investigation on new materials use for the construction of the sewage system.

Technology selection for wastewater collection and convey Definition of design parameters for the sewerage system Design of sewerage system according to the selected technologies

Selection of agreed upon technology with participation of stakeholders in the design and construction of the sewage system (public service companies, urban developers, municipal government, environmental authority)

Training and new technologies dissemination workshops.

Economic incentives to reduce wastewater production

Estimation of investment and O&M cost of innovative technologies

Economic and financial feasibility studies of innovative technologies

Proposals for the update of technical standards, considering new trends.

Med

ium

term

(con

t.)

Control of wastewater discharges Decreasing domestic wastewater discharged into the sewage system. Follow up and control of industrial discharges. Characterization of wastewater quality and quantity Evaluation of control and follow up indicators of the waste discharges into the sewage system.



Active participation of the industry in the planning and compliance of goals for the elimination of wastewater discharges.

Economic incentives to

reduce wastewater discharges and pollutant load and encourage water consumption reduction

Adjust tariff standards and

methodologies according to the new wastewater management trends.

Long

term

New technologies for wastewater collection and transportation. Design of sewerage system according to the selected technologies Implementation or replacement of sewage networks and complementary structures according to the selected technologies (grey water, urine and feces transportation).

Sewerage database updating Operation and maintenance of the real time monitoring network Systematic monitoring of the sewage network.

Planning and

implementation of technical standards for the design of the sewage system.



Table 7.16 Proposal of short, medium and long term actions in “stormwater collection” component. Sector 1: Drainage area to WwTP-C

Technical Aspects Institutional aspects Economic tools Policies and regulations Data from drainage system Drainage systems inventory Topographic survey and data systems. Sewage system data systems (real time or programmed monitoring). Characterization and selection of technologies for sewerage system modelling

Urban drainage modelling Construction of sewage operation and drainage network scenarios.

Operation, and maintenance of the drainage system Identification of the status of drainage system components. Inventory of illegal connections. Plan for the elimination of erroneous channel connections. Stormwater pump system optimization Reposition and maintenance of structures (canals, separation structures and solid separation structures)

Control of solid waste and debris disposal into the sewage system.

Real time control of the sewerage system Sewer and drainage systems inventory Identification of drainage system monitoring stations (pluviometric, climatologic)

Characterization of monitoring technologies Definition of monitoring parameters and sampling frequency Selection of monitoring technologies (equipment, data transmission systems, sensors)

Monitoring network design

Interinstitutional coordination to form a monitoring network.

Pollution control Characterization of stormwater runoff water quality and quantity Estimate the contamination load Pollution control from domestic and industrial wastewater discharges in the drainage system

Dilution of contaminant peaks Definition of treatment objectives and selection of stormwater treatment technologies.

Education campaigns related with solid waste management

Shor

t ter

m

Flood control Characterization of stormwater runoff water quality and quantity Identification of areas susceptible of flooding. Optimization of the pumping system and evacuation of storm waters. Estimate IFD curves and hydrograms for the city (considering climatic changes).

Technical standards to the using new water management trends.



Table 7.16 Proposal of short, medium and long term actions in “stormwater collection” component. Sector 1: Drainage area to WwTP-C (cont.)

Technical Aspects Institutional aspects Economic tools Policies and regulations Flood control (cont.) Modelling of the system for the planning of storm water storage and buffer zones.

Predesign of the network and complementary storage structures for flooding control. Support the modelling.

Protection and recovery of the natural regulation system: El Pondaje and Chaco Ault Lagoons.

Shor

t ter

m (c

ont.)

Innovative technologies Identification of areas susceptible of flooding. Characterization of stormwater runoff water quality and quantity Characterization of the technological supply (green strips, in line storage, control structures, green covers, and porous pavements).

Pilot scale study and demonstration projects of innovative technologies Definition of design parameters Estimate future storm water quantities considering the implementation of innovative technologies.

Socialization and dissemination of rain water management technologies.

Education campaigns and socialization programs about water use efficiency

Data from sewerage systems Database updating Performance forecast and sewage system planning (design specifications).

Urban drainage modelling

Operation and maintenance of stormwater drainage system Reposition and maintenance of structures (canals, separation structures and solid separation structures)

Protection of urban rivers and basins Control of solid waste and debris disposal into the sewage system.

Real time control of the sewerage system Implementation of real time monitoring network within combined sewerage system

Implementation of the system control structures (gates, valves, storage) migrating from a static to a dynamic system.


Estimation of investment and O&M cost of monitoring network

Med

ium

term

Pollution control Implementation of flood control and contamination peaks dilution structures (gates, storage, valves, separation structures) operated in real time.

Technology selection for stormwater management Construction and start up of the storm water management system.




Definition of the discharged stormwater quality standards - sanitary substances



Table 7.16 Proposal of short, medium and long term actions in “stormwater collection” component. Sector 1: Drainage area to WwTP-C (cont.)


Med

ium

term

Flood control Construction of storm water quantity and quality scenarios considering the implementation of new technologies.

Adjustment of in-line and complementary storage structures for the control of floods.

Optimization of the pumping system and evacuation of storm waters.


Technical standards to drainage system design considering new urban water management trends.

Long

term

Urban drainage modelling Reposition and maintenance of structures (canals, separation structures and solid separation structures)

Control of solid waste and debris disposal into the sewage system. Implementation of innovative technologies for flood control at household level and urban zones (green strips, storage, control structures, green covers, porous pavement).

Operation and maintenance of drainage system Construction and start up of the storm water management system. Real time operation of the sewerage and drainage networks

Technical standards to drainage system design considering new water management trends.

Table 7.17 Proposal of short, medium and long term actions in “wastewater treatment and disposal” component. Sector 1:

Drainage area to WwTP-C

Technical Aspects Institutional aspects Economic tools Policies and regulations Minimization of wastewater production in the household - water use efficiency Promote the culture of water efficient use and conservation.

Greywater reuse Characterization of greywater water quality and quantity Definition of water uses in the home Characterization of greywater management technologies (storage,

treatment, disinfection, pumping equipment, distribution) Technology selection for greywater management in the housing Definition of design parameters Implementation of pilot scale study and demonstration projects

Issuance of design standards.

Shor

t ter

m

Dry sanitation - separation of urine and excreta at source Social, technical and economic diagnosis and viability studies. Community surveys Collection of national and international experiences. Characterization of sanitation systems - Dry sanitation Evaluation of the potential use of liquid and solid waste.

Education campaigns and socialization programs about dry sanitation systems


Assessment of the technical feasibility and economic viability



Table 7.17 Proposal of short, medium and long term actions in “wastewater treatment and disposal” component. Sector 1: Drainage area to WwTP-C (cont.)

Technical Aspects Institutional aspects Economic tools Policies and regulations Wastewater management in the WwTP- C Diagnosis of the influence sector. Pollution control from domestic and industrial wastewater discharges Characterization of wastewater quality and quantity Evaluation of environmental impacts in the receptor body and estimate of water source risks for potential use.

Evaluation of treated wastewater reuse potential Estimate supply and demand of treated wastewater. Definition of treatment objectives considering the receptor source uses and the quality of discharged waters.

Characterization of secondary wastewater treatment technologies Predesign of the selected technologies for the wastewater secondary treatment.

Pilot scale study and demonstration projects of wastewater treatment alternatives

Technology selection for secondary wastewater treatment Design of selected wastewater secondary treatment technology

Interinstitutional agreements between entities and the agricultural sector (sugar cane) to stimulate the use of treated wastewater. .

Participation of different sectors in the decision making processes.


Cost-benefit analysis Assessment of the technical feasibility and economic viability

Control of industrial wastewater discharges

Modification of the current rates of water for agricultural use

Definition of treatment objectives according to wastewater quality and use.

Shor

t ter

m (c

ont.)

Stormwater management Stormwater quality and quantity characterization Online storage Estimate the contamination load - first wash-off phenomenon Estimate the receptor water body self-purification capacity. Evaluation of the potential re-use. Feasibility studies of secondary wastewater treatment in the WwTP-C


Assessment of the technical feasibility and economic viability - Cost-benefit analysis

Greywater management Adequacy of water and sanitation facilities Design and implementation of individual systems for the use of grey water (storage + treatment + distribution)

Dry sanitation - separation of urine and excreta at source Pilot scale study and demonstration projects of dry sanitation alternatives

Characterization of technologies for solid waste collection Technology selection for dry sanitation systems Identification of final disposal sites. Design of dry sanitation systems

Training programs and socialitization of innovative technologies



Modification of the tariff structure.

Wastewater management in the WwTP-C Implementation of the wastewater secondary treatment system.

Med

ium

term

Stormwater management Implementation of the stormwater treatment system.



Table 7.17 Proposal of short, medium and long term actions in “wastewater treatment and disposal” component. Sector 1: Drainage area to WwTP-C (cont.)

Technical Aspects Institutional aspects Economic tools Policies and regulations Greywater management Control, optimization and maintenance of hydraulic and sanitary facilities for the use of greywater.

Training programs

Wastewater management in the WwTP-C Optimization and maintenance of the wastewater secondary treatment system.

Stormwater management Optimization and maintenance of the storm water treatment system.

Long

term

Dry sanitation - separation of urine and excreta at source Implementation and maintenance of dry sanitation systems

Processes of management and operational adaptation for the implementation of dry sanitation systems.


Economic incentives to implement dry sanitation systems

Soft credits for the implementation of dry sanitation technologies.


Table 7.18 Proposal of short, medium and long term actions in “solid waste management” component. Sector 1: Drainage area to

WwTP-C Technical Aspects Institutional aspects Economic tools Policies and regulations

Shor

t an

d m

ediu

m te

rm

Citizen culture Identification and classification of the solid waste in all city sectors (domestic, industrial, institutional, commercial etc.)

Implementation of education programs and campaigns to stimulate minimizing the production, reuse and recycling of solid waste.

Proposal and execution of an education program for the separation of household solid waste

Training on management, storage and disposal of toiletries material (toilet paper, sanitary pads, condoms, etc.).

Identification of stakeholders that may support education and awareness campaigns (EMSIRVA, JAL, JAC, NGOs, other organizations).

Design and execution of Information, Education and Communication strategies (IEC) with the participation of the different generators, for the MIRS

Strengthening of the environmental management system, SIGAM

Strengthening of the School Environmental Projects in the education institutions with regards to solid waste with emphasis on the separation, reduction and recycling practices.

Articulation and strengthening of the different community, social and solidary communities working on environmental programs.

Design and application of incentive programs stimulating the reduction, reuse and recycling of solid waste.

Fiscal and economic incentives for encourage CP activities

Create policies focused towards: - Minimizing the amount of solid waste generated. - Increase in the rational use of solid waste. - Improvement of waste elimination, treatment and disposal systems.



Table 7.18 Proposal of short, medium and long term actions in “solid waste management” component. Sector 1: Drainage area to WwTP-C (cont.)

Technical Aspects Institutional aspects Economic tools Policies and regulations Innovative technologies and cleaner production Characterization and implementation of technologies for the housing solid waste treatment (compost, lombricompost)

Socialization and technology stimulation campaigns of new technologies for household wastewater treatment.

Adoption of cleaner production strategies (minimization, prevention, appropriate use of solid waste)

Promotion of technologies for solid waste treatment.


Commercial and industrial solid waste PGIRS implementation in the entrepreneurial sector considering the waste solids final disposition.

Training on CP processes and technologies application. Promotion of productive chains with CP Development of an environmental entrepreneurial acknowledgment program.

Implementation of an environmental entrepreneurial recognition program.

Consultancy and orientation for environmental management enterprises.

Financial resources management and tax benefits.

Debris management Implementation of a control plan for the generation, separation, storage, transportation and disposal of debris, without affecting the environment and human health.

Location of transfer stations and final waste disposition sites, as well as adapting them for their operation.

Investigation for the implementation of gross or transformed waste use alternatives.

Design and development of selective debris collection programs with the participation of stakeholders and sanitation service provider companies through the allowed transportation system.

Market places and others. Proposal and implementation of an integrated improvement plan for the sanitation and solid waste collection systems in market places and distribution centres.

Establishment of plan monitoring and control mechanism Promotion of organic matter classification and separation. Promotion of incentives for the sale of organic solid waste treatment products and by-products

Establishment and strengthening of the plants to use organic waste

Implementation of policies for the integrated improvement of sanitation and waste collection systems at market places and food distribution centres.

Shor

t an

d m

ediu

m te

rm (c

ont.)

Waste collection and transportation Solid waste characterization (quality and quantity) Design and optimization of routes for selective collection depending on collection frequency and coverage expansion of the service, equipment and machinery.

Implementation of selective collection program: willingness and ability to pay studies




Technical Aspects Institutional aspects Economic tools Policies and regulations Waste collection and transportation (cont.) Equipment replacement, upgrading and maintenance. Design and implementation of a large size solid waste collection and disposal (furniture, mattresses, etc.)

Design and implementation of a debris collection and disposal program

Recovery, use and commercialization. Promotion of the separation at the generation source. Study, design and implementation of distribution centres and transfer stations.

Design and application of incentive programs to promote solid waste reduction, re-use and recycling.

Participation of the solidary sector and recyclers in elaborating and executing solid waste integrated management plans.

Investigation, adoption and application of sustainable technologies for the reduction, management, storage, treatment and final disposition of solid waste and debris. Optimization of processes and decrease of environmental contamination, water resource impact and Cali's drainage systems.

Investigation of solid waste use and treatment technologies.

Promotion of the participation of organized recyclers for the recovery of solid waste.

Project management oriented to the promotion of the marketing of solid waste treatment products

Promotion of the creation of strategic alliances with the productive sectors, the academia, governmental and non-governmental organizations

Final disposal of solid waste Selection and acquisition of solid waste final disposition sites. Definition of the location of transfer stations and final debris disposal sites, as well as planning the operations.

Follow up and control of the solid waste final disposition sites (aquifer protection and water resources)

Shor

t an

d m

ediu

m te

rm (c

ont.)

Institutional, follow-up and control Design and implementation of the necessary control and monitoring system with the corresponding instruments for the surveillance and control of generators and the solid waste management service providing entities.

Implementation of a control and follow up plan for the generation, separation, storage, transportation and disposal of waste in the city.

Definition of indicators for the provision of solid waste collection, transportation, treatment and final disposal services.

Definition and implementation of policies for the integrated improvement of the sanitation and solid waste collection systems





Shor

t an

d m

ediu

m te

rm

(con

t)

Control of solid waste disposal into the sewage system. Development and implementation of education campaigns on the solid residues impact (domestic, industrial, institutional, commercial, etc) in water bodies and drainage systems in Cali.

Incorporation of the solid waste integrated management in the projects executed in the drainage system of the city of Cali.

Definition of mechanisms for a strategic alliance between the academia, the productive sector, the government organizations, and NGOs to incentive non-contaminating alternatives research.

Development of plans that provide the instruments that allow the environmental authorities to support the municipal and regional solid waste integrated management.

Long

term

Control of solid waste discharges into the sewage system. Follow-up and control of the generation, separation, storage, transportation and disposition of solid waste in the city of Cali.

Table 7.19 Proposal of short, medium and long term actions in “river basin” component. Sector 1: Drainage area to WwTP-C

Technical aspects Institutional aspects Economic tools Policies and regulations Actions for ecosystem protection and restoration Special management areas set by regional environmental authorities. Reforesting of the Cali and Aguacatal River basins Maintenance of the Cali and Aguacatal Rivers’ protecting strip Consideration of environmental threats, vulnerability and risks, as well as hydroclimatic regimes in the Cali and Aguacatal River basins.

Shor

t ter

m

Actions for soil use regulation Classification of the potential soil uses according to physical, ecological and socio-economic factors

Development of conservation and recovery practices by soil users. Crop regulation and flora and fauna management Intervention on the use of public or private terrains in the event of erosion, earth movement, salinization and degradation due to improper soil usage.

Control of the use and disposition of contaminating substances. Identification of critical areas for the recovery and control of disaster control and the landscape conservation and recovery.

Relocation of subnormal settlements in the upper Cali and Aguacatal River basins.

Acquisition of environmental protection terrains by the municipal government.

Definition of instruments for resource allocation in order to incentive the reforestation and stimulate the conservation of natural ecosystems.

Stimulate agricultural and animal husbandry production processes

Application of technical standards to avoid soil loss or degradation in order to achieve soil recovery and conservation.



Table 7.19 Proposal of short, medium and long term actions in “river basin” component. Sector 1: Drainage area to WwTP-C (cont.)

Technical aspects Institutional aspects Economic tools Policies and regulations Regulation actions through environmental licenses. Coherence between licenses granted by national and regional authorities and the territorial regulation and basin management plans.

Environmental impact studies in order to grant environmental licenses.

Regulation of water sources Implementation of water usage rates to stimulate users to rationalize water consumption.

Allocation of concessions according to water supply and demand.

Stimulate agricultural and animal husbandry production processes to diminish negative

Development of regulations to grant concessions.

Regulation of discharges and waste disposal Feasibility studies on water reuse in the river basin Diagnosis, operation and management of the urban drainage system. Definition of discharge standards (water bodies and sewage) Final discharges characterization (quality and quantity) Access of authorities to the discharge sites Users’ obligation to use their effluents. Restricted use of agro-chemical products in areas close to the water bodies.

Creation of a follow up committee formed by the municipal government, public services companies and users

Economic incentives to reduce wastewater discharges and encourage CP activities

Fund collection for the improvement of water resources.

Implementation of water usage rates to stimulate users to rationalize water consumption.

Citizen participation. Participation of the civil society in the direction of regional autonomous corporations.

Development of water use efficiency programs Follow up of the compliance with granted concessions. Installation of water consumption gauging devices. Surveillance and control by environment authority

Implementation of citizenship participation instruments in the planning, identification of priorities and decision making processes

Urban planning Expropriation of terrains declared of social interest and for public use. Urban plans incorporating the environmental component and the anthropic environmental relations.

Urbanization considering minimum impermeabilization. Government purchase of terrains for parks and green zones.

Shor

t ter

m (c

ont.)

Basin management Development of a basin regulation plan considering the POT, water use, discharges and soil uses regulations, special management areas, environmental management and funding plans.

Development of a diagnosis, planning, execution and follow-up process for the basin management plans.

Diagnosis of the Cali and Aguacatal River basins to provide policy objectives and instruments to be applied.

Formation of joint work groups for the river basins covering more than one jurisdiction area.

Strengthening of the technical and planning offices of the

Definition of investments and costs derived from actions and measures included in the management plans according to basin’s priorities.

Combination of policy instruments with direct participation of stakeholders at national, regional and local level




Technical aspects Institutional aspects Economic tools Policies and regulations

Shor

t ter

m (c

ont.)

Basin management (cont.) Development of a follow-up and control program for the evaluation of basins. Development of interinstitutional and intersectorial work of entities involved in basin regulations and water resource management.

corporations, establishing agreements and alliances to obtain technical support.

Consolidation of the institutional capacity to act as planning and environmental regulatory authority.

Canalize the own investment resources and those of committed stakeholders to have direct influence over the protection, conservation and recovery of the basin’s renewable natural resources.

Actions for ecosystem protection and restoration Monitoring and follow-up of the surface and ground water supply. Special management areas follow-up. Reforesting of the Cali and Aguacatal River basins. Maintenance of the Cali and Aguacatal Rivers’ protecting strip.

Actions for soil use regulation Relocation of subnormal settlements in the upper Cali and Aguacatal River basins.

Development of conservation and recovery practices by soil users. Crop regulation and flora and fauna management. Intervention on the use of public or private terrains in the event of erosion, earth movement, salinization and degradation due to improper soil usage.

Control of the use and disposition of contaminating substances

Stimulate agricultural and animal husbandry production processes to diminish negative impact over the environment and the renewable natural resources.

Regulation actions through environmental licenses. Monitoring and follow-up of the surface and ground water supply. Environmental impact studies in order to grant environmental licenses.

Fiscal incentives for encourage CP activities


Regulation of water sources Allocation of concessions according to water supply and demand.

Med

ium

term

Regulation of discharges and waste disposal Implementation of the reuse of water in the hydrographic basin after complying with the quality standards for each use.

Diagnosis, operation and management of the urban drainage system.

Training of personnel from competent institutions in charge of the regulation of water reuse.

Economic incentives for water reuse




Technical aspects Institutional aspects Economic tools Policies and regulations Citizen participation. Development of water use efficiency programs Follow up of the compliance with granted concessions. Surveillance and control by environment authority

Urban planning Urban plans incorporating the environmental component and the anthropic environmental relations.

Urbanization considering minimum impermeabilization.

Med

ium

term

(con

t.)

Watershed management Implementation and follow up of the Cali and Aguacatal River basins’ management.

Implementation of the statistic information system and follow up indicators and evaluation of the environmental policy and the interinstitutional and intersectorial resources for the follow up of water resources.

Consolidation of the data generation and management protocols.

Long

term




7.3.2 Sector 2 South Drainage System

Table 7.20 Proposal of short, medium and long term actions in “Household”component. Sector 2: South Drainage System

Technical Aspects Institutional aspects Economic tools Policies and regulations Reduction of water consumption Water loss control in the housing Participation in training programs about water use efficiency, minimization and prevention

Replacement and use of low water consumption devices. Reduction of basic consumption (l/inhab/d)

Education campaigns

and socialization programs about water use efficiency




Greywater management Voluntary reuse of grey waters at household level (washing machine, showers). Implementation of simple grey water collection systems.




Quality standards for

the use of storm waters.

Shor

t te

rm

Stormwater management Characterization of household water uses. Storm water supply and demand study by city sectors. Stormwater characterization (quality and quantity) and identification of potential uses

Characterization and selection of storm water capture, storage and distribution technologies.

Investigation of the design parameters of the hydraulic and sanitary installations for the use of storm water.

Predesign of technologies for the use of storm waters (capture + pumping + storage + treatment)


Promotion of the sustainability culture and environmental education.


Economic and financial feasibility studies of stormwater systems

Issuance of technical standards for house construction according to the new water management trends.

Reduction of water consumption Participation in training programs about water use efficiency, minimization and prevention

Replacement and use of low water consumption devices. Reduction of basic consumption (l/inhab/d)

Water loss control Education campaigns and socialization programs about water use efficiency

Economic incentives

for encourage water consumption reduction


Tariff’s study and re-adjustment.

Med

ium

term

Stormwater management Design and implementation of stormwater systems (captation, pumping, storage, treatment, distribution)

Participation in training programs about the efficient use of water and the use of new technologies.


Evaluation and Internalization of Externalities

Issuance of technical

standards for house construction according to the new water management trends.



Table 7.20 Proposal of short, medium and long term actions in “Household” component. Sector 2: South Drainage System (cont.)

Technical Aspects Institutional aspects Economic tools Policies and regulations Greywater management Implementation of grey water re-circulation systems in new urbanizations and households.

Modification of the existing hydraulic and sanitary facilities considering the new trends for household water management.


feasibility studies


Med

ium

term

(con

t.)

Dry sanitation Characterization of dry sanitation technologies and its social and cultural acceptance.

Feasibility studies of dry sanitation systems Investigation of the design parameters of the hydraulic and sanitary installations for dry sanitation (urine and feces)

Pilot scale study and demonstration projects Predesign of technologies for dry sanitation.

Education campaigns

and socialization programs about dry sanitation systems


Estimation of

investment and O&M cost of dry sanitation systems


Reduction of water consumption Use of drinking water exclusively for basic needs (consumption, food

preparation, personal hygiene)


Long

term

Dry sanitation Acquisition and installation of separation of urine and excreta devices (dry sanitation)

Adequacy of water and sanitation facilities for dry sanitation systems Implementation of hydraulic and sanitation facilities for new housing constructions.





Table 7.21 Proposal of short, medium and long term actions in “Industry” component. Sector 2: South Drainage System Technical Aspects Institutional aspects Economic tools Policies and regulations

Shor

t ter

m

Pollution prevention and control Update and inventory of the industries discharging waste in the south drainage system

Identification and geo-reference of discharge sites Monitoring and follow up of the quality of the water discharged into the sewage system.

Update and collection of data on historically discharged load. Characterization of the industrial production processes and identification of the characteristics of wastewater

Planning CP alternatives to be applied to processes using and generating wastewater

Preliminary technology selection of CP Environmental and technical assessment Assessment of the technical feasibility and economic viability for cleaner production activities

Selection of feasible alternatives to implement the CP program. Program for the implementation of CP policies in agreement with the productive sector and competent environmental authority, setting environmental quality goals.

Optimization of processes Implementation of the Cleaner Production program. Setting of follow up and evaluation indicators Evaluation and follow up of the CP program implementation.

Assistance in the implementation of environmental management systems as CP strategy


Creation of an agreement environment for the environmental authorities and the productive sector to facilitate the understanding and continuous dialogue for a shared sustainable development vision.

Strengthening of the institutional capacity for the implementation of environmental policies, training, monitoring and follow-up and communication channels for the dissemination of results and experiences

Estimate cost-benefit ratio generated by the increase in process efficiency, savings in the consumption of raw materials and energy, and the decrease of waste and contaminating emissions.

Creation of economic and financial resources incentive mechanisms to support CP implementation and co-funding of projects in the productive sectors.

Regulation of tax incentives according to Law 223/95

Overprice of materials and products with high contamination indexes and have a less contaminating alternative, used in the productive processes.

Issuance of standards for the prevention of contamination, promoting technological innovation, the search of more efficient and effective environmental and economic solutions.

Definition of follow-up and evaluation mechanisms for the agreements made between the environmental authority and the productive sector.

Set clear environmental goals for the productive sectors.



Table 7.21 Proposal of short, medium and long term actions in “Industry” component. Sector 2: South Drainage System (cont.) Technical Aspects Institutional aspects Economic tools Policies and regulations

Med

ium

term

Pollution prevention and control Monitoring and follow up of the quality of the water discharged into the sewage system.

Follow up and control of the CP program. Life cycle assessment Objectives definition and application Life cycle inventory analysis: mass balances Environmental impact and risk assessment Environmental risk management. Comparative risk analysis Economic impact assessments

Strengthening of the communication channels and dissemination of CP information, healthy environmental technologies, Colombian environmental legislation and options to support the implementation of CP in the industry.

Long

term

Pollution prevention and control Total implementation of the CP program for the elimination of industrial discharges into the south drainage system

Follow up and control of the CP program.


Table 7.22 Proposal of short, medium and long term actions in “Water supply system” component. Sector 2: South Drainage

System Technical Aspects Institutional aspects Economic tools Policies and regulations

Shor

t ter

m

Pollution prevention Minimization of wastewater production in the housing - water use efficiency encourage

Greywater and stormwater reuse



Stimulate lower






Table 7.22 Proposal of short, medium and long term actions in “Water supply system” component. Sector 2: South Drainage System (cont.)

Technical aspects Institutional aspects Economic tools Policies and regulations Pollution control of the water supply - Cauca River Protection of the Lili, Meléndez and Cañaveralejo River basin (domestic and agricultural discharge control, control and relocation of settlements, reforesting).

Protection of the Cauca River tributaries. Pollution control upstream of the water intake (domestic, industrial and agricultural wastewater discharges)

Control of industrial wastewater discharges into the drainage system (CP program and pollution control goals)

Elimination of wastewater discharges into the canals of the south drainage system

Follow up and control of the Navarro Dump closure program – leachates management

Proposal and implementation of the POMCH


Development of education campaigns to incentive the culture for the efficient use and saving of water in the community.



Setting of environmental goals and objectives for the control of sanitary interest substance emissions.


Shor

t ter

m (c

ont.)

Runoff pollution control in the South Drainage system Protection of the Lili, Meléndez and Cañaveralejo River basin (domestic and agricultural discharge control, control and relocation of settlements, reforesting).

Design and implementation of solids retention structures Frequently clean and maintenance of the South Channel Design and implementation of a water quality surveillance network to the Cauca River

Reposition and maintenance of structures (canals, separation structures and solid separation structures)

Stormwater quality and quantity characterization Feasibility studies considering potential uses and treatment goals Study of innovative technologies for runoff pollution control (green strips, storage, dilution, control structures, green covers, porous pavement, stormwater treatment).

Technology selection Implementation of pilot scale study and demonstration projects Definition of design parameters Water loss control in water distribution systems and storage tank Optimization of water distribution networks Optimization of water treatment processes Operation, maintenance and replacement of distribution system elements.

Interinstitutional coordination to form a monitoring network of Cauca River water quality




Quality standards for the use of stormwater and greywater





Technical aspects Institutional aspects Economic tools Policies and regulations Pollution prevention Saving and water use efficiency encourage Greywater and stormwater reuse Characterization of technologies to rainwater and greywater use as an alternative water source (captation, pumping, storage, treatment, distribution)

Definition of design parameters (rain water captation, storage and distribution )


Education campaigns





Technical standards for the construction of households using new water management trends.

Pollution control of the water supply - Cauca River Protection of the Lili, Meléndez and Cañaveralejo River basin (domestic and agricultural discharge control, control and relocation of settlements, reforesting).

Protection of the Cauca River tributaries. Pollution control upstream of the water intake (domestic, industrial and agricultural wastewater discharges)

Follow up and control of industrial discharges in the sewage system (compliance with decontamination goals).

Follow up and control of the Navarro Dump closure program – leachates management

Proposal and implementation of the POMCH






Setting of environmental goals and objectives for the control of sanitary interest substance emissions.


Runoff pollution control in the South Drainage system Frequently clean and maintenance of the South Channel Operation of the water quality surveillance network in the Cauca river Reposition and maintenance of structures (canals, separation structures and solid separation structures)

Implementation of stormwater management technologies – pollution runoff control

Sewage system data systems (real time or programmed monitoring).



Med

ium

term

Water treatment, distribution and storage Water loss control in water distribution systems and storage tank Optimization of water distribution networks Optimization of water treatment processes Operation, maintenance and replacement of distribution system elements.




Technical aspects Institutional aspects Economic tools Policies and regulations Pollution prevention Promote the culture of water efficient use and conservation. Implementation of grey and storm water collection systems as an alternative water supply


Pollution control of the water supply - Cauca River Protection of the Lili, Meléndez and Cañaveralejo River basin (domestic and agricultural discharge control, control and relocation of settlements, reforesting).

Pollution control upstream of the water intake (domestic, industrial and agricultural wastewater discharges)

Elimination of industrial discharges into the drainage system Follow up and control of the Navarro Dump closure program – leachates management

Follow up and control of decontamination goals compliance according to the Cauca River water quality objectives.


Long

term

Runoff pollution control in the South Drainage system Frequently clean and maintenance of the South Channel Operation of the water quality surveillance network in the Cauca river Reposition and maintenance of structures (canals, separation structures and solid separation structures)

Real time operation of the South drainage system



Table 7.23 Proposal of short, medium and long term actions in “wastewater collection” component. Sector 2: South Drainage

System

Technical aspects Institutional aspects Economic tools Policies and regulations Data from sewerage systems Monitoring programmed and final discharges characterization Topographic survey Data systems - SIG Sewage system data systems (real time or programmed monitoring). Characterization of technologies for sewerage system modelling Selection of the hydroinformatics tool. Wastewater Sewerage Modelling Construction of sewage operation scenarios.


institutions that generate useful information for the sewage system operation.

Estimation of

investment and O&M cost of the sewer system automation

Shor

t ter

m

Operation and maintenance of sewerage system Identification of the status of sewage system components. Reposition and maintenance of structures (canals, separation structures and

solid separation structures)



Table 7.23 Proposal of short, medium and long term actions in “wastewater collection” component. Sector 2: South Drainage System (cont.)

Technical aspects Institutional aspects Economic tools Policies and regulations Real time control of the sewerage system Monitoring programmed and final discharges characterization Identification of sewage system monitoring stations (pluviometric,

climatologic) Characterization of technologies for sewerage system monitoring Definition of monitoring parameters and sampling frequency Selection of monitoring technologies (equipment, data transmission systems,

sensors) Monitoring network design Design of an early warning system - EWS (monitoring parameters, stations

design, equipment and sensors, others)


institutions that generate useful information for the sewage system operation. .

Strengthening the

decision-making participation of the different productive sectors

Monitoring programmed Selection of sewage surveillance and control monitoring sites. Monitoring the sewage systems’ surveillance and control points. Definition of monitoring parameters and sampling frequency Inventory and characterization of the industrial discharges. Monitoring programmed and final discharges characterization Design of the sewage system control structures (gates, valves, storage, etc.,)

Shor

t ter

m (c

ont.)

Control of wastewater discharges Minimization of wastewater production in the housing - water use efficiency

encourage Wastewater production planning according to new wastewater management

trends. Follow up and control of industrial discharges Follow up and control of solid waste and debris in the sewage system. Characterization of wastewater quality and quantity Setting indicators for the control and follow-up of discharges into the sewage

system.

Education campaigns


Active participation of the industry in the planning and compliance of goals for the elimination of wastewater discharges.

Economic incentives

for encourage water consumption reduction

Adjust tariff standards

and methodologies according to the new wastewater management trends.

Data from sewerage systems Database updating Construction of system operation scenarios. Performance forecast and sewage system planning (design specifications).

Med

ium

term

New technologies for wastewater collection and transportation. Characterization of innovative technologies for wastewater collection systems Wastewater production planning according to new wastewater management trends.

Feasibility studies and implementation of innovative technologies Development of demonstration projects Implementation of demonstration projects using innovative technologies. Investigation on new materials use for the construction of the sewage system.

Training and new

technologies dissemination workshops.

Economic incentives to reduce wastewater production


Proposals for the update of technical standards, considering new trends.



Table 7.23 Proposal of short, medium and long term actions in “wastewater collection” component. Sector 2: South Drainage

System (cont.)

Technical aspects Institutional aspects Economic tools Policies and regulations New technologies for wastewater collection and transportation (cont.) Technology selection for wastewater collection and convey Definition of design parameters for the sewerage system Design of sewerage system according to the selected technologies

Selection of agreed

upon technology with participation of stakeholders in the design and construction of the sewage system


feasibility studies of innovative technologies

Planning and

implementation of technical standards for the sewage design, considering the implementation of innovative technologies.

Real time control of the sewerage system Implementation of real time monitoring network within sewage system Systematic monitoring of the sewage network. Implementation of the system control structures (gates, valves, storage) migrating from a static to a dynamic system.

Implementation and operation of the EWS in accordance with the operational objective (flood control in the drainage system and pollution control)

Operation and maintenance of the real time monitoring network

Participation of the institutions that generate useful information for the sewage system operation

Med

ium

term

(con

t.)

Control of wastewater discharges Decreasing domestic wastewater discharged into the sewage system. Follow up and control of industrial discharges Characterization of wastewater quality and quantity Evaluation of control and follow up indicators of the waste discharges into the sewage system.


Active participation of the industry in the planning and compliance of goals for the elimination of waste water discharges.


Economic incentives to reduce wastewater discharges and pollutant load

Adjust tariff standards

and methodologies according to the new wastewater management trends.

Long

term

New technologies for wastewater collection and transportation. Design of sewerage system according to the selected technologies Implementation or replacement of sewage networks and complementary structures according to the selected technologies (grey water, urine and feces transportation).

Sewerage database updating Operation and maintenance of the real time monitoring network Operation, and maintenance of the EWS Systematic monitoring of the sewage network. Estimate generated wastewater quantity and quality

Planning and

implementation of technical standards for the design of the sewage system.



Table 7.24 Proposal of short, medium and long term actions in “stormwater collection” component. Sector 2: South Drainage System

Technical Aspects Institutional aspects Economic tools Policies and regulations Data from drainage system Drainage systems inventory Topographic survey Data systems - SIG Sewage system data systems (real time or programmed monitoring). Characterization of technologies for sewerage system modelling Selection of the hydroinformatics tool. Urban drainage modelling Construction of sewage operation and drainage network scenarios.

Operation and maintenance of sewerage system Identification of the status of drainage system components. Inventory of illegal connections. Plan for the elimination of illegal channel connections. Stormwater pump system optimization Reposition and maintenance of structures (canals, separation structures and solid separation structures)

Protection of urban rivers and basins Design and construction of solid separation systems at the s Meléndez, Lili and Cañaveralejo River basins.

Control of solid waste and debris disposal into the sewage system.

Real time control of the sewerage system Sewer and drainage systems inventory Identification of drainage system monitoring stations (pluviometric, climatologic)

Characterization of monitoring technologies Definition of monitoring parameters and sampling frequency Selection of monitoring technologies (equipment, data transmission systems, sensors)

Monitoring network design


Shor

t ter

m

Pollution control Characterization of stormwater runoff water quality and quantity Estimate the contamination load Pollution control from domestic and industrial wastewater discharges in the drainage system

Dilution of contaminant peaks Definition of treatment objectives and selection of stormwater treatment technologies

Design and/or optimization of the storm water management system.




Table 7.24 Proposal of short, medium and long term actions in “stormwater collection” component. Sector 2: South Drainage System (cont.)

Technical Aspects Institutional aspects Economic tools Policies and regulations Flood control Stormwater characterization (quality and quantity) Identification of areas susceptible of flooding. Optimization of the pumping system and evacuation of storm waters. Estimate IFD curves and hydrograms for the city (considering climatic changes).

Modelling of the system for the planning of storm water storage and buffer zones.

Predesign of the network and complementary storage structures for flooding control. Support the modelling.

Protection of urban rivers and basins making part of the drainage system. Design of an early warning system - EWS (monitoring parameters, stations design, equipment and sensors, others)

Recovery of the buffer zones after rainfall events (city wetlands).


Shor

t ter

m (c

ont.)

Innovative technologies Estimate future storm water quantities considering the implementation of innovative technologies.

Characterization of the technological supply (green strips, in line storage, control structures, green covers, and porous pavements).

Pilot scale study and demonstration projects of innovative technologies Definition of design parameters

Socialization and dissemination of rainwater management technologies.

Data from sewerage systems Database updating Construction of system operation scenarios. Performance forecast and sewage system planning (design specifications). Urban drainage modelling

Operation and maintenance of stormwater drainage system Reposition and maintenance of structures (canals, separation structures and solid separation structures)

Protection of urban rivers and basins Control of solid waste and debris disposal into the sewage system.

Med

ium

term

Real time control of the sewerage system Implementation of real time monitoring network within combined sewerage system

Systematic monitoring of the sewage network. Implementation of the system control structures (gates, valves, storage) migrating from a static to a dynamic system.






Table 7.24 Proposal of short, medium and long term actions in “stormwater collection” component. Sector 2: South Drainage System (cont.)

Technical Aspects Institutional aspects Economic tools Policies and regulations Flood control Construction of storm water quantity and quality scenarios considering the implementation of new technologies.

Adjustment of in-line and complementary storage structures for the control of floods - Modelling support

Optimization of the pumping system and evacuation of storm waters. Protection of urban rivers and basins making part of the drainage system.

Design of an early warning system - EWS (monitoring parameters, stations design, equipment and sensors, others)


Med

ium

term

(con

t.)

Pollution control Implementation of flood control and contamination peaks dilution structures (gates, storage, valves, separation structures) operated in real time.

Technology selection for stormwater management Construction and start up of the storm water management system. Stormwater characterization (quality and quantity) and identification of potential uses




Definition of the treatment objectives according to the receptor source uses.


Long

term

Urban drainage modelling Reposition and maintenance of structures (canals, separation structures and solid separation structures)

Protection of urban rivers and basins Control of solid waste and debris disposal into the sewage system. Protection of urban rivers and basins making part of the drainage system. Operation, and maintenance of the EWS (parameters, stations design, equipment, sensors, location of monitoring points, and others)

Characterization of stormwater runoff water quality and quantity Implementation of innovative technologies for flood control at household level and urban zones (green strips, storage, control structures, green covers, porous pavement).

Operation and maintenance of drainage system Construction and start up of the storm water management system. Real time operation of the sewerage and drainage networks





Table 7.25 Proposal of short, medium and long term actions in “wastewater treatment and disposal” component. Sector 2: South Drainage System

Technical Aspects Institutional aspects Economic tools Policies and regulations Minimization of wastewater production in the Household - water use efficiency Promote the culture of water efficient use and conservation.

Greywater reuse Characterization of greywater water quality and quantity Definition of water uses in the home Characterization of technologies to greywater use as an alternative water source (captation, pumping, storage, treatment, distribution)

Technology selection for greywater management in the household Definition of design parameters (sizing of online storage, recirculation equipment, treatment, distribution)


Definition of design standards.

Dry sanitation - separation of urine and excreta at source Social, technical and economic diagnosis and viability studies. Community surveys Collection of national and international experiences. Characterization of sanitation systems - Dry sanitation Evaluation of the potential use of liquid and solid waste.

Education campaigns to encourage community attitude change to water use



Wastewater management in the WwTP-South Diagnosis of the influence sector. Characterization of wastewater quality and quantity Evaluation of environmental impacts in the receptor body and estimate of water source risks for potential use.

Identification and control of sanitation interest substances Evaluation of treated wastewater reuse potential Estimate supply and demand of treated wastewater. Definition of treatment objectives considering the receptor source uses and the quality of discharged waters.

Characterization of wastewater technologies and management Predesign of the selected technology. Pilot scale study and demonstration projects of wastewater treatment alternatives

Technology selection process for wastewater treatment Design of selected wastewater treatment technology

Interinstitutional agreements between entities and the agricultural sector (sugar cane) to stimulate the use of treated wastewater.

Participation of different sectors in the decision making processes.

Cost-benefit analysis Estimation of investment and O&M cost


Control of industrial wastewater discharges

Modification of the current rates of water for agricultural use

Definition of treatment objectives according to wastewater quality and use.

Shor

t ter

m

Stormwater management Stormwater quality and quantity characterization Online storage Estimate the contamination load - first wash-off phenomenon Estimate the receptor water body self-purification capacity. Evaluation of the potential re-use.

Feasibility studies of wastewater treatment in the WwTP-South



Table 7.25 Proposal of short, medium and long term actions in “wastewater treatment and disposal” component. Sector 2: South Drainage System (cont.)

Technical Aspects Institutional aspects Economic tools Policies and regulations Minimization of wastewater production in the Household - water use efficiency Promote the culture of water efficient use and conservation.

Greywater management Adequacy of water and sanitation facilities Design and implementation of individual systems for the use of grey water (storage + treatment + distribution)

Dry sanitation - separation of urine and excreta at source Pilot scale study and demonstration projects of dry sanitation alternatives Characterization of technologies for solid waste collection Technology selection for dry sanitation systems Identification of final disposal sites. Design of dry sanitation systems

Training programs and socialitization of innovative technologies




Med

ium

term

Wastewater management in the WwTP-South Implementation and start up of the wastewater treatment system.

Greywater management Control, optimization and maintenance of hydraulic and sanitary facilities. Control, optimization and maintenance of the individual systems for the use of grey water.

Wastewater management in the WwTP-South Optimization and maintenance of the wastewater secondary treatment system.

Long

term

Dry sanitation - separation of urine and excreta at source Implementation and maintenance of dry sanitation systems

Processes of management and operational adaptation for the implementation of dry sanitation systems.



Assessment of the technical feasibility and economic viability - Cost-benefit analysis

Economic incentives to implement dry sanitation systems





Table 7.26 Proposal of short, medium and long term actions in “solid waste management” component. Sector 2: South Drainage System

Technical Aspects Institutional aspects Economic tools Policies and regulations Citizen culture Identification and classification of the solid waste in all city sectors (domestic, industrial, institutional, commercial etc.)

Implementation of education programs and campaigns to stimulate minimizing the production, reuse and recycling of solid waste.

Proposal and execution of an education program for the separation of household solid waste

Training on management, storage and disposal of toiletries material (toilet paper, sanitary pads, condoms, etc.).

Identification of stakeholders that may support education and awareness campaigns (EMSIRVA, JAL, JAC, NGOs, other organizations).

Design and execution of Information, Education and Communication strategies (IEC) with the participation of the different generators, for the MIRS

Strengthening of the School Environmental Projects in the education institutions with regards to solid waste with emphasis on the separation, reduction and recycling practices.

Strengthening of the environmental management system, SIGAM, as an instrument for the planning.

Articulation and strengthening of the different community, social and solidary communities working on environmental programs.

Design and application of incentive programs stimulating the reduction, reuse and recycling of solid waste.


Create policies focused towards: - Minimizing the amount of solid waste generated. - Increase in the rational use of solid waste. - Improvement of waste elimination, treatment and disposal systems.

Innovative technologies and cleaner production Characterization and implementation of technologies for the housing solid waste treatment (compost, lombricompost)

Socialization and technology stimulation campaigns of new technologies for household wastewater treatment.

Adoption of cleaner production strategies (minimization, prevention, appropriate use of solid waste)

Promotion of technologies for solid waste treatment.


Commercial and industrial solid waste PGIRS implementation in the entrepreneurial sector considering the waste solids final disposition.

Training on CP processes and technologies application. Promotion of productive chains with CP Development of an environmental entrepreneurial acknowledgment program. Implementation of an environmental entrepreneurial recognition program.

Consultancy and orientation for environmental management enterprises.

Financial resources management and tax benefits.

Sh

ort

and

med

ium

term

Debris Management Implementation of a control plan for the generation, separation, storage, transportation and disposal of debris.

Location of transfer stations and final waste disposition sites, as well as adapting them for their operation.

Investigation for the implementation of gross or transformed waste use alternatives.

Design and development of selective debris collection programs with the participation of stakeholders and sanitation service provider companies through the allowed transportation system.



Table 7.26 Proposal of short, medium and long term actions in “solid waste management” component. Sector 2: South Drainage System (cont.)

Technical Aspects Institutional aspects Economic tools Policies and regulations Market places and others. Proposal and implementation of an integrated improvement plan for the sanitation and solid waste collection systems in market places and distribution centres.

Establishment of plan monitoring and control mechanism Promotion of organic matter classification and separation. Promotion of incentives for the sale of organic solid waste treatment products and by-products

Establishment and strengthening of the plants to use organic waste

Implementation of policies for the integrated improvement of sanitation and waste collection systems at market places and food distribution centres.

Waste collection and transportation Solid waste characterization (quality and quantity) Design of routes for selective collection depending on collection frequency and coverage expansion of the service, equipment and machinery.

Collection and route optimization Equipment replacement, upgrading and maintenance. Design and implementation of a large size solid waste collection and disposal (furniture, mattresses, etc.)

Design and implementation of a debris collection and disposal program

Implementation of selective collection program: willingness and ability to pay studies

Recovery, use and commercialization. Promotion of the separation at the generation source. Study, design and implementation of distribution centres and transfer stations. Design and application of incentive programs to promote solid waste reduction, re-use and recycling.

Participation of the solidary sector and recyclers in elaborating and executing solid waste integrated management plans.


Promotion of the creation of strategic alliances with the productive sectors, the academia, governmental and non-governmental organizations to incentive the investigation and non-contaminating alternatives.

Promotion of the participation of organized recyclers for the recovery of solid waste.

Project management oriented to the promotion of the marketing of solid waste treatment products

Shor

t an

d m

ediu

m te

rm (c

ont.)

Final disposal of solid waste Selection and acquisition of solid waste final disposition sites. Definition of the location of transfer stations and final debris disposal sites, as well as planning the operations.

Follow up and control of the solid waste final disposition sites (aquifer protection and water resources)



Table 7.26 Proposal of short, medium and long term actions in “solid waste management” component. Sector 2: South Drainage System (cont.)

Technical Aspects Institutional aspects Economic tools Policies and regulations Navarro Dump closure Study, design and implementation of technologies for the treatment of leachates and by-products of the Navarro dump.

Implementation of a follow up and monitoring program for the contamination plume (soil and water resources) of the Navarro Dump’s leachates.

Landscape and environmental recovery of the area occupied by the Navarro Dump.

Institutional, follow-up and control Design and implementation of the necessary control and monitoring system with the corresponding instruments for the surveillance and control of generators and the solid waste management service providing entities.

Implementation of a control and follow up plan for the generation, separation, storage, transportation and disposal of waste in the city.

Definition of indicators for the provision of solid waste collection, transportation, treatment and final disposal services.

Definition and implementation of policies for the integrated improvement of the sanitation and solid waste collection systems at market places and food distribution centres and establish execution monitoring and control.

Shor

t an

d m

ediu

m te

rm (c

ont.)

Control of solid waste discharges into the sewage system. Development and implementation of education campaigns on the solid residues impact (domestic, industrial, institutional, commercial, etc) in water bodies and drainage systems in Cali.

Incorporation of the solid waste integrated management in the projects executed in the drainage system of the city of Cali.

Definition of mechanisms for a strategic alliance between the academia, the productive sector, the government organizations, and NGOs to incentive non-contaminating alternatives research.

Development of plans that provide the instruments that allow the environmental authorities to support the municipal and regional solid waste integrated management.

Long

term

Control of solid waste discharges into the sewage system. Follow-up and control of the generation, separation, storage, transportation and disposition of solid waste in the city of Cali.

Follow up and monitoring of leachates generated by the Navarro Dump. Landscape and environmental recovery of the area occupied by the Navarro Dump.



Table 7.27 Proposal of short, medium and long term actions in “River Basin” component. Sector 2: South Drainage System Technical aspects Institutional aspects Economic tools Policies and regulations

Actions for ecosystem protection and restoration Special management areas set by regional environmental authorities. Characterization and quantification of the basin’s aquifer supply Reforesting of Lili, Meléndez, Cañaveralejo and Pance River basins Maintenance of the Lili, Meléndez, Cañaveralejo and Pance Rivers’ protecting strip

Consideration of environmental threats, vulnerability and risks, as well as hydroclimatic regimes in the Lili, Meléndez, Cañaveralejo and Pance River basins.

Actions for soil use regulation Classification of the potential soil uses according to physical, ecological and socio-economic factors for each region.

Development of conservation and recovery practices by soil users. Crop regulation and flora and fauna management Intervention on the use of public or private terrains in the event of erosion, earth movement, salinization and degradation due to improper soil usage.

Control of the use and disposition of contaminating substances. Identification of critical areas for the recovery and control of disaster control and the landscape conservation and recovery.

Relocation of subnormal settlements in the upper Lili, Meléndez, Cañaveralejo and Pance River basins.

Acquisition of environmental protection terrains by the municipal government.



Application of technical standards to avoid soil loss or degradation in order to achieve soil recovery and conservation.

Regulation actions through environmental licenses. Coherence between licenses granted by national and regional authorities and the territorial regulation and basin management plans.

Environmental impact studies in order to grant environmental licenses.

Shor

t ter

m

Regulation of water sources Implementation of water usage rates to stimulate users to rationalize water consumption.

Allocation of concessions according to water supply and demand.

Stimulate agricultural and animal husbandry production processes to diminish negative

Collection of financial resources for investment programs.

Development of regulations to grant concessions.



Table 7.27 Proposal of short, medium and long term actions in “River Basin” component. Sector 2: South Drainage System (cont.)

Technical aspects Institutional aspects Economic tools Policies and regulations Regulation of discharges and waste disposal Feasibility studies on water reuse in the river basin Diagnosis, operation and management of the urban drainage system. Definition of discharge standards (water bodies and sewage) Final discharges characterization (quality and quantity)

- Access of authorities to the discharge sites - Users’ obligation to use their effluents.

Restricted use of agro-chemical products in areas close to the water bodies.

Creation of a follow up committee formed by the municipal government, public services companies and users

Economic incentives to reduce wastewater discharges

Fiscal incentives for encourage CP activities


Implementation of water usage rates to stimulate users to rationalize water consumption.

Citizen participation. Participation of the civil society in the direction of regional autonomous corporations.

Development of water use efficiency programs Follow up of the compliance with granted concessions. Installation of water consumption gauging devices. Surveillance and control by environment authority

Implementation of citizenship participation instruments in the planning, identification of priorities and decision making processes for the allowation of public resources.

Urban planning Expropriation of terrains declared of social interest and for public use. Urban plans incorporating the environmental component and the anthropic environmental relations.

Urbanization considering minimum impermeabilization. Government purchase of terrains for parks and green zones.

Shor

t ter

m (c

ont.)

Basin management Development of a basin regulation plan considering the POT, water use, discharges and soil uses regulations, special management areas, environmental management and funding plans.

Development of diagnose, planning, execution and follow-up process for the basin management plans.

Diagnosis of the Lili and Pance River basins to provide policy objectives and instruments to be applied.

Development of a follow-up and control program for the evaluation of basins. Development of interinstitutional and intersectorial work of entities involved in basin regulations and water resource management.


Strengthening of the technical and planning offices of the corporations, establishing agreements and alliances to obtain technical support.


Canalize the own investment resources and those of committed stakeholders to have direct influence over the protection, conservation and recovery of the basin´

Combination of policy instruments with direct participation of stakeholders at national level (ministries and planning, statistics and research institutes), regional level (autonomous corportation) and territorial level (departments, districts and municipalities)




Technical aspects Institutional aspects Economic tools Policies and regulations Actions for ecosystem protection and restoration Monitoring and follow-up of the surface and ground water supply. Special management areas follow-up. Reforesting of Lili, Meléndez, Cañaveralejo and Pance River basins Maintenance of the Lili, Meléndez, Cañaveralejo and Pance Rivers' protecting strip

Actions for soil use regulation Relocation of new subnormal settlements in the upper Lili, Meléndez, Cañaveralejo and Pance River basins.

Development of conservation and recovery practices by soil users. Crop regulation and flora and fauna management. Intervention on the use of public or private terrains in the event of erosion, earth movement, salinization and degradation due to improper soil usage.

Control of the use and disposition of contaminating substances.


Regulation actions through environmental licenses. Monitoring and follow-up of the surface and ground water supply Environmental impact studies in order to grant environmental licenses.


Regulation of water sources Allocation of concessions according to water supply and demand.

Regulation of discharges and waste disposal Implementation of the reuse of water in the hydrographic basin after complying with the quality standards for each use.

Diagnosis, operation and management of the urban drainage system.

Training of personnel from competent institutions in charge of the regulation of water reuse.

Incentives for water reuse

Citizen participation. Development of water use efficiency programs Follow up of the compliance with granted concessions. Surveillance and control by environment authority

Urban planning Urban plans incorporating the environmental component and the anthropic environmental relations.

Urbanization considering minimum impermeabilization.

Med

ium

term

Basin management Implementation and follow up of the Lili, Meléndez, Cañaveralejo and Pance River basins’ management.

Implementation of the statistic information system and follow up indicators and evaluation of the environmental policy and the interinstitutional and intersectorial resources for the follow up of water resources.

Consolidation of the data generation and management protocols.




Technical aspects Institutional aspects Economic tools Policies and regulations

Long

term




7.3.3 Sector 3 expansion area The revision studies made by DAPM for the characterization of the ARDN zone consider that this sector shall not make urban projects. Instead, the zone shall be promoted as an environmental reserve area for the city. For that reason, it is not included within the proposal for pollution control in the city of Cali. The city planning, and particularly the future expansion areas, shall promote a healthy environment. This situation cannot be guaranteed in this zone if for instance, atmospheric pollution risks generated by Navarro Dump gases are evaluated. The city still does not count with an epidemiological study that shows the true incidence of gas inhalation in the health of its inhabitants due to waste decomposition, although it is speculated that it is related to the presence of different illnesses. This situation deserves a specific study. The water potential of the zone could be considered as a reserve for the city of Cali. This would be at risk in the event of the city’s urbanization that would cause the impermeabilization of a considerable area, affecting its own recharging capability and would generate the possibility of pollution, such as in the case of wastewater infiltrations. Although the occupancy model based on the knowledge of the environmental characteristics and natural threats present in the Navarro Expansion Zone defines two Soil Protection categories: environmental soil protection and Natural Threats Soil Protection, which would not generate urban development. There is an intrinsic threat caused by subnormal settlements if we consider that the zone is proposed for social sectors with medium and low socioeconomic level, which in case of not having constant social support, could result in situations such as that of Chaco Ault or La Laguna del Pondaje, where flooding buffer zones and wetlands were dried off in order to create soil for possible human settlements. On the other hand, the potential of soil liquification associated with the possibility of lateral sliding, which would affect the stability of the Cauca River’s Protection Levee. This would generate flooding risks, affecting the potential security of the area’s inhabitants, as well as the generation of high urbanization costs which result from building foundations, roadways and pipeline installation conditions. The zone has a considerable environmental potential which is worth preserving and maintaining, as well as wetlands, old riverbeds where enormous amounts of native flora and fauna and migratory species live. These species would be affected if urbanization of the area took place, being a construction that would represent innumerable environmental costs. This would also represent high initial investment, operation and maintenance costs that the city would have, such as those in Aguablanca. In the future, these costs would be transferred not only to the area’s inhabitants, but to the entire population of Cali.



Table 7.28 Proposal of short, medium and long term actions in “Household” component. Sector 3: Expansion area Technical Aspects Institutional aspects Economic tools Policies and regulations

Shor

t ter

m

Reduction of water consumption Participation in training programs about water use efficiency, minimization and prevention

Characterization of household water uses. Design of hydrosanitary facilities with efficient use concepts that consider: low consumption devices, greywater recycle, rainwater use, water use environmental education

Construction of a model house with water use efficiency systems


Study and adjustment of the basic consumption (l/inhab/d)





Study and adjustment of the water tariff


Minimizing water consumption, use of greywaters and stormwaters. Water loss control in the housing. Installation of low water consumption devices. Participation in training programs about the efficient use of water and the use of new technologies

Implementation of greywater re-circulation systems stomwater collection systems in new urbanizations and households.

Interinstitutional participation in household planning )

Evaluation and internalization of externalities

Med

ium

term

Dry Sanitation Characterization of dry sanitation technologies and its social and cultural acceptance

Feasibility studies of dry sanitation systems Investigation of the design parameters of the hydraulic and sanitary installations for dry sanitation (urine and feces)

Predesign of technologies for dry sanitation (capture + pumping + storage + treatment)

Education campaigns

and socialization programs about dry sanitation systems


and O&M cost for dry sanitation systems


Long

term

Minimizing water consumption, use of greywaters and stormwaters. Use of drinking water exclusively for basic needs (consumption, food preparation, personal hygiene).

Construction of urbanizations and condos having water resources integrated management.

Dry sanitation Construction of a model house with dry sanitation systems Installation of dry sanitation technology. Acquisition and installation of separation of urine and excreta devices (dry sanitation).

Adequacy of water and sanitation facilities for dry sanitation systems. Implementation of hydraulic and sanitation facilities for new housing constructions.

Soft credits for the

implementation of dry sanitation technologies.



Table 7.29 Proposal of short, medium and long term actions in “Industry” component. Sector 3: Expansion area Technical Aspects Institutional aspects Economic tools Policies and regulations

Shor

t ter

m

New technologies for wastewater collection and transportation. Characterization of innovative wastewater collection and convey technologies. Wastewater production planning according to new wastewater management trends.

Technology selection for wastewater collection and convey. Feasibility studies and implementation of innovative technologies Design of networks and systems according to the corresponding flows for the efficient use of water, greywater transportation systems.

Follow up and control of solid waste and debris in the sewage system. . Construction of system operation scenarios using innovative technologies.


Sewage usage education campaigns.

Selection of agreed upon technology with participation of stakeholders in the design and construction of the sewage system

Training and new technologies dissemination workshops.

Estimation of investment and O&M cost of the sewer system automation

Economic incentives to reduce wastewater discharges and pollutant load


Economic and financial feasibility studies to implement innovative technologies

Proposals for the

update of technical standards, considering new trends.

Planning and implementation of technical standards for the sewage design, considering the implementation of innovative technologies.

Adjust tariff standards and methodologies according to the new wastewater management trends.

Med

ium

term

Real time control of the sewerage system Setting indicators for the control and follow-up of discharges into the sewage system.

Performance forecast and sewage system planning (design specifications). Implementation of demonstration projects. Sewerage database updating. Systematic monitoring of the sewage network.


Med

ium

term

(Con

t.) New technologies for wastewater collection and transportation.

Investigation on new materials use for the construction of the sewage system. Investigation of urine and feces management systems – Dry sanitation. Implementation of real time monitoring network within sewage system Implementation of the system control structures (gates, valves, storage) migrating from a static to a dynamic system.






Table 7.29 Proposal of short, medium and long term actions in “Industry” component. Sector 3: Expansion area (Cont.) Technical Aspects Institutional aspects Economic tools Policies and regulations

Long

term

Real time control of the sewerage system Operation and maintenance of the real time monitoring network Implementation (reposition) of sewage networks and complementary structures according to selected technologies (transportation of grey water, urine and feces).

Sewerage database updating Operation and maintenance of the real time monitoring network Operation, and maintenance of the EWS Systematic monitoring of the sewage network. Implementation of condominium systems within the conventional and block urbanizations to collect condominium systems through the main roads.

Urine and feces management in compost systems for the production of fertilizers.

Estimation of investment and O&M cost of innovative technologies - Cost-benefit analysis

Table 7.30 Proposal of short, medium and long term actions in “Stormwater collection” component. Sector 3: Expansion area

Technical Aspects Institutional aspects Economic tools Policies and regulations Innovative Technologies Characterization of stormwater runoff water quality and quantity Characterization of monitoring network technologies Identification of drainage system monitoring stations (pluviometric, climatologic)

Characterization of the technological supply (green strips, in line storage, control structures, green covers, and porous pavements).

Pilot scale study and demonstration projects of innovative technologies Definition of design parameters Estimate future storm water quantities considering the implementation of innovative technologies.

Definition of treatment objectives and selection of stormwater treatment technologies

Construction of system operation scenarios. Performance forecast and sewage system planning (design specifications).) Construction of storm water quantity and quality scenarios considering the implementation of innovative technologies.

Technology selection for stormwater management Design of sustainable urban drainage system combined with conventional stormwater systems


Education campaigns and socialization programs about water use efficiency.

Urban plans incorporating the environmental component and the anthropic environmental relations.




Adjust standards and application mechanisms associated with urbanization elements according to the environmental component.

Definition of the treatment objectives according to the receptor source uses. Sh

ort t

erm

Flood control Protection of urban rivers and basins Identification of areas susceptible of flooding.

Promotion of preventive measures for soil and water conservation.




Table 7.30 Proposal of short, medium and long term actions in “Stormwater collection” component. Sector 3: Expansion area (cont.)


Pollution control Design and construction of solid separation systems at the s Meléndez, Lili and Cañaveralejo River basins.

Control of solid waste and debris disposal into the sewage system


Real time control of the sewerage system Selection of monitoring technologies (equipment, data transmission systems, sensors)

Modelling of the system for the planning of storm water storage and buffer zones.

Database updating Implementation of the system control structures (gates, valves, storage) migrating from a static to a dynamic system.

Implementation of real time monitoring network within combined sewerage system


Med

ium

term

Innovative technologies Implementation of innovative technologies for flood control at household level and urban zones (green strips, storage, control structures, green covers, porous pavement).

Implementation of green zones and covers Retention and damping systems of the flow peaks Decentralization of the discharge sites.


Long

term

Innovative technologies Recollection of water captured for the maintenance of institutional and neighbouring zones.

Use of water captured for irrigation purposes and institutional use.



Table 7.31 Proposal of short, medium and long term actions in “Water supply system” component. Sector 3: Expansion area Technical Aspects Institutional aspects Economic tools Policies and regulations

Shor

t ter

m

Storm water stored and become an alternate water supply source Information and education campaigns. Prioritization of applicable sector strategies (characterization and estimate of leak location strategies efficiency and selection of strategies to reduce loss volumes and strategies optimization

Pressure control through the use of valves

Cost-benefit analysis considering innovative alternatives in sanitation and water supply (dry sanitation, rainwater use and greywater use)

Integration of standards for the use of grey and storm waters as an alternative source of water supply

Med

ium

and

L

ong

term

Pressure minimisation in water distribution for reduction of consumption Dissemination of efficient water use strategies. Use of water captured for irrigation purposes and institutional use.

Table 7.32 Proposal of short, medium and long term actions in “Treatment and reuse of wastewater” component. Sector 3:

Expansion area


Shor

t ter

m

Technology selection considering natural methods for wastewater treatment Study and evaluation of the wastewater reuse possibility in the nearby sugar cane crops zone.

Final discharges characterization (quality and quantity) Design Wastewater Management Decentralized Systems Pilot scale study and demonstration projects of wastewater treatment alternatives

Estimation of investment and O&M cost of WwTP-South


Considering the mandatory reuse of wastewater

Med

ium

term

Design of the sugar cane irrigation system using domestic wastewater. Establish policies for the use and management of sludge resulting from drinking water treatments and those from the sewage and waste water treatment systems.

Long

term

Use of treated wastewater and treatment sludge for neighbouring sugar cane plantations.

Recollection for institutional use of the treatment gas generated. Implementation of natural systems for the WwTP South.



Table 7.33 Proposal of short, medium and long term actions in “Solid waste management” component. Sector 3: Expansion area Technical Aspects Institutional aspects Economic tools Policies and regulations

Shor

t ter

m

Identification and classification of solid waste in all city sectors (domestic, industrial, institutional, commercial etc.)


Implementation of the control plan for domiciliary solid waste generation, separation, storage, transportation and disposition.

Implementation of transfer stations and final debris disposition, as well as operation upgrading.

Investigation on solid waste use and treatment technologies.

Interinstitutional coordination (EMSIRVA, Control Organisms and Administrative Development Direction).

Application of incentive programs that stimulate the reduction, reuse and recycling of solid waste.

Establish penalties for the users that do not recycle.

Define the mandatory recycling of solid waste at its source.

Med

ium

term

Investigation, adoption and application of sustainable technologies for the reduction, management, storage, treatment and final disposition of solid waste and debris.

Implement technologies for the use and treatment of solid waste. Implement a plan to control the generation, separation, storage, transportation and disposition of city waste.

Long

term

Decentralization of solid waste management. Composting of organic municipal solid waste Solid waste is a resource through recycling and reuse of organic and inorganic matter.

Table 7.34 Proposal of short, medium and long term actions in “River basin” component. Sector 3: Expansion area

Technical Aspects Institutional aspects Economic tools Policies and regulations Ecosystems protection and recovery. Special management areas set by regional environmental authorities. Characterization and quantification of the basin’s aquifer supply. Reforesting of the Lili and Pance River basins Maintenance of the Lili and Pance Rivers' protecting strip Consideration of environmental threats, vulnerability and risks, as well as hydroclimatic regimes

Shor

t ter

m

Soil use regulation. Application of technical standards to avoid soil loss or degradation in order to achieve soil recovery and conservation.

Development of conservation and recovery practices by soil users. Crop regulation and flora and fauna management.


Application of

technical standards to avoid soil loss or degradation in order to achieve soil recovery and conservation.



Table 7.34 Proposal of short, medium and long term actions in “River basin” component. Sector 3: Expansion area (cont.) Technical Aspects Institutional aspects Economic tools Policies and regulations

Soil use regulation (cont.) Intervention on the use of public or private terrains in the event of erosion, earth movement, salinization and degradation due to improper soil usage.

Identification of critical areas for the recovery and control of disaster control and the landscape conservation and recovery.

Relocation of subnormal settlements in the upper Lili and Pance River basins. Acquisition of environmental protection terrains by the municipal government.

Stimulate agricultural and animal husbandry production processes to diminish negative impact over the environment and the renewable natural resources

Discharge regulation and waste disposition. Feasibility studies on water reuse in the river basin Definition of discharge standards (water bodies and sewage) Final discharges characterization (quality and quantity) Forbidden disposal of solid waste into water bodies. Restricted use of agro-chemical products in areas close to the water bodies.

Implementation of instruments for citizen participation in the planning processes to identify priorities and decision making in public resources allocation.

Economic incentives to reduce wastewater discharges and encourage CP activities


Definition of the discharge standards (water bodies and sewage).

Regulation through environmental licenses. Coherence between licenses granted by national and regional authorities and the territorial regulation and basin management plans.

Urban planning Expropriation of terrains declared of social interest and for public use. Urbanization considering minimum impermeabilization. Government purchase of terrains for parks and green zones.



Shor

t ter

m (C

ont.)

Basin management Setting priorities and water planning and management goals at national, regional and local level, as well as responsibilities and entity articulation mechanisms.

Development of a basin regulation plan considering the POT, water use, discharges and soil uses regulations, special management areas, environmental management and funding plans.

Development of interinstitutional and intersectorial work of entities involved in basin regulations and water resource management.

Development of a follow-up and control program for the evaluation of basins.

Formation of an intersectorial technical committee for water resources’ planning.


Creation of the basin committees for the follow up of all processes.

Canalize the own investment resources and those of committed stakeholders to have direct influence over the protection, conservation and recovery of the basin’s renewable natural resources.

Combination of policy instruments with direct participation of stakeholders at national level (ministries and planning, statistics and research institutes), regional level (autonomous corportation) and territorial level (departments, districts and municipalities)



Table 7.34 Proposal of short, medium and long term actions in “River basin” component. Sector 3: Expansion area (Cont.) Technical Aspects Institutional aspects Economic tools Policies and regulations

Med

ium

and

Lo

ng te

rm

Provide continuity and follow-up of activities in the short and medium term

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Cali, Demonstration City Wastewater Management Framework for the Cali City of Cali, Colombia

ANNEXES



ANNEX 1 Main Institutions related with the

management, regulating and controlling of water resources

Annex 1. Main institutions related with the management, regulating and controlling of water resources

Sustainable Water Improves Tomorrow’s Cities’ Health SWITCH Project A1-2

Table A1.1 At national level, main institutions involved with the management, regulating and controlling of water resources

Institution Description Ministry for the environment, housing and development (Ministerio de Ambiente, Vivienda y Desarrollo Territorial, MAVDT):

It defines policies and regulations at technical, economical and planning level for the recovery, conservation, protection, management and favorably use of the environmental resources like water among others.

Water and sanitation regulatory �omisión (Comisión Reguladora de Agua Potable y Saneamiento, CRA):

It set regulations at technical and legal level to control water institutions and guarantee a good delivery of services.

Public services commission (Superintendencia de Servicios Públicos Domiciliarios, SSPD):

It controls, inspects and regulates the public services institutions (ESP) and verify their compliance with national policies, service to users, finances and technical regulations. It also monitors the fate of governmental subsidies within the water framework.

National Planning directive (Dirección Nacional de Planeación, DNP):

Designs, guides and evaluates the Colombian public policies, the assigned national given investments and the involvement framework for the private companies

Institute for Hydrology, Meteorology and Environmental Studies - IDEAM.

Providing counseling to the regional environmental agencies (CAR's) in the implementation and operation of the Environmental Information System in accordance with the guidelines of the Ministry of the Environment, Housing and Territorial Development (MAVDT); Maintaining information about the use of renewable resources (especially water, soil and air) and factors that contaminate and affect or deteriorate these resources, thereby working jointly with the CARs. Supplying information for drafting environmental quality standards and rules; and Conducting studies and research projects in cooperation with other institutions aiming at establishing parameters/limits for contaminating emissions, discharges, and other conditions that are detrimental to the environment

Table A1.2 At Regional level, main institutions involved with the management, regulating

and controlling of water resources Institution Description

Department of Valle del Cauca: It is the local government authority in the region. It establishes and guides development policies and the proper delivery of public services inside the department. It also monitors the economic resources donated by the central government and their appropriate use.

Autonomous Regional Corporation of the Valle del Cauca (Corporación Autónoma Regional del Valle del Cauca, CVC)

It is the environmental authority for the Valle del Cauca department. It promotes environmental sustainable development among all the involved parts in the region within the national environmental network. It grants environmental permits, imposes environmental punishments (in case of violations of environmental laws and policies) and establish laws and policies for the management of the river basins in the department.

Public Heath secretary It aims to improve quality of life of the community ensuring an optimal level of health. It guarantees the environmental sustainability in order to reach a good socio-economical level in the community. It also implements prevention policies when the environment and the community are at risk.

Annex 1. Main institutions related with the management, regulating and controlling of water resources


Table A1.3 At local level, main institutions involved with the management, regulating and controlling of water resources

Institution Description Municipal administration: The municipalities must promote and carry on the national policies and

programs. They must in a direct or indirect way finance projects related to public service infrastructure, flood prevention, river decontamination; technical assistance to the agriculture sector, protection of the environment, adequate use of water bodies; social participation promotion in the decision making for the delivery of services. Inside the municipal administration there are sub-dependencies which are directly or indirectly responsible for the management of the water resource. Such dependencies are: municipal council; Administrative municipal planning department; Administrative department for the management of the environment (Departamento Administrativo de Gestión del Medio Ambiente, DAGMA) and Health secretaries

- Municipal council

Its functions are to establish reform or eliminate taxes, economical contributions and manage the municipal budget according to the Municipal Development Plan.

- Administrative municipal planning department

It is in charge of monitoring and establishing sustainable development of the city according to the land ordering plan (Plan de Ordenamiento Territorial, POT).

- Administrative department for the management of the environment (Departamento Administrativo de Gestión del Medio Ambiente, DAGMA)

Its establishment is required when the population in the community is higher than 1’000,000 inhabitants. It’s the local environmental authority whose mission is to strive for the sustainable development of the environment inside the legal framework and policies set by the Ministry for the Environment.

Public services delivery companies: Cali’s Municipal Water Services company, EMCALI: Solid waste municipal company, EMSIRVA:

The 1991 political constitution gives power to the Nation to guarantee the delivery of basic services such as drinking water and sanitation to all Colombians. The delivery of services can be carried out by public or private companies. In the city of Cali the public companies that provide these services are EMCALI and EMSIRVA companies: It contributes to the well-being and development of the community guaranteeing economic conditions throughout the delivery of essential public services such drinking water and sewerage services. Its mission is to guarantee an optimal integrated management of solid waste, ensuring a) social and economic benefits for the community, b) permanent organizational development of the company, c) educational campaigns in favor of the protection of the environment and d) continual improvement in the quality of the service and relations with the users.


Cali, Demonstration City Wastewater Management Framework for the City of Cali, Colombia

ANNEX 2

Strategies proposed by the institutions classified according to the urban water cycle

Annex 2. Strategies proposed by the institutions classified according to the urban water cycle


Table A2.1 Strategies and projects proposed by the institutions in regional plans to the Cali’s wastewater management

Item Regional Plan for the Management of the

Environment in Valle del Cauca Department - PGAR

Triennial Action Plan (PAT) Plan for the development of the department (PDD)

Validity (years) 2002 – 2012 2007 – 2009 2008 – 2011

Formulated by Regional Corporation of the Valle del Cauca (CVC)


Valle del Cauca goverment

Housing

Industry

Implementation of Cleaner Production policies to reduction of at least 30% of current contamination in the Cauca River caused by chemical and industrial waste discharge by year 201

Water supply system

Identify, set priorities and make viable investment in the water supply, sanitation and housekeeping sectors.

Increase the aqueduct and sewage services coverage in the urban and rural sectors.

Contribute in the protection and sustainability of the water supply in urban and rural aqueducts of Valle del Cauca.

Wastewater collection

Inversiones zona urbana de Cali Identify, set priorities and make viable investment in the water supply, sanitation and housekeeping sectors.


Stormwater Drainage

Inversiones zona urbana de Cali Identify, set priorities and make viable investment in the water supply, sanitation and housekeeping sectors.


Treatment and disposal wastewater

Design and construction of domestic wastewater treatment systems in the urban centers of Valle del Cauca.

Solid waste management

Support the implementation of Programs for proper solid waste use and disposal (Support the implementation of PGIRS)

Identify, set priorities and make viable investment in the water supply, sanitation and housekeeping sectors.

Improve urban and rural solid waste treatment and disposal in the department of Valle del Cauca.



Table A2.1 Strategies and projects proposed by the institutions in regional plans to the Cali’s wastewater management (Cont.) Item Regional Plan for the Management of the Environment in Valle del

Cauca Department (PGAR) Triennial Action Plan (PAT) Plan for the development of the

department (PDD)

River basin

Proposal and implementation of the Environmental Management Plans for the river basins.

Promotion and strengthening of the Cauca River Integrated Management Plan.

Expansion and automation of the quality and quantity monitoring network for surface waters.

Proposal of River Basin Management and Development Plans – POMCH

Modeling of river basins. Process of natural resource characterization and prioritization of environmental situations.

Decontamination and reduction of the Cauca River contaminant factors in the Valle del Cauca Department.

Institutional

Strengthening of interinstitutional coordination to obtain 100% environmental management of the river basins.

Interinstitutional agreements to facilitate the development and implementation of the system for environmental management

Promotion and strengthening of environments for agreement.

Water resource management with community participation (funds for Project pending).

Policies and regulations

Implementation of Land Management Plans-POT. Establishment of follow up mechanisms for the Land Management Plan - POT.

Economic Development of economic mechanisms to obtain public space benefits resulting in their improvement.



Table A2.2 Strategies and projects proposed by the institutions in local plans to the Cali’s wastewater management

Item Land Ordering Plan (POT) Municipal Plan for the

Management of the Environment (PGAC)

Plan for Sanitation and Management of Wastewater

Discharges (PSMV)

Plan for the development of Cali (PDC)

Formulated by National Planning Directive (DNP) – Cali Majoralty DAGMA - ASOCARS EMCALI Cali Majoralty

Validity period (years) 2000 – 2009 2005 – 2019 2007 – 2016 2008 – 2011

Housing

Control construction and urban developments. (3)

Modernization and strengthening, construction and urban development control.

Proposal of a partial plan. Cali-Jamundí expansion.

Implementation a public space management plan including new orientations and national and international policies framed within a new urban development habitat model

Industry

Water supply system

Implementation of the integrated plan for the recovery and conservation of water sources

Control and use of ground water. Coordinate with Acuacali the proposal for the water conservation and efficient use plan for Cali.

Technical study for the acquisition of strategically located areas dedicated to the conservation of water resources.

* Follow up and control of sludge management in Cali (sludge generated by the different drinking water plants).

Design and construction of Navarro’s deep well.

Navarro aqueduct networks improvement. Expansion of the purification, conduction and matrix plants, pumping, storage tanks, secondary networks, lots, and relocation of settlements, designs, auditing and consultancy.

Improvement of plant and basin quality standards. Optimization and improvement of matrixes, conduction, pumping and tanks, reposition of secondary networks, control of drinking water, prevention of vulnerability, operative centers.

Surface water recovery and conservation

Ground water management plans Groundwater quality control and conservation

Proposal for the Master Plan for Public Services.

Coverage expansion and improvement of urban public service quality.

Sustainable water supply Support and management of the proposed Departmental Water and Basic Sanitation plan.



Table A2.2 Strategies and projects proposed by the institutions in local plans to the Cali’s wastewater management (Cont.)



Plan for Sanitation and Management of Wastewater Discharges (PSMV)

Plan for the development of Cali (PDC)

Wastewater collection

Design and construction of individual waste water systems in Navarro.

Sewage planning and control. Expansion of waste water treatment plant, collectors and sanitation interceptors, rainfall canals and collectors, secondary networks, study designs, consultancy.

Quality improvement of secondary networks replacement, replacement of old brick collectors, optimization and improvement of channels, ponds, dams and pumping stations, collectors upgrading and canal waste water control.

Develop and implement Sanitation and Discharge Management Plans.

Implementation of an Integrated Sewage Information System for the city (Cadastre)

Inventory and diagnosis of each separation structure that include the location, hydraulic operation, physical condition and operation and maintenance condition.

Optimize existing separation structures, location and design of new structures.

Construction works proposed in the PSMV.



Support and management of the proposed Departmental Water and Basic Sanitation plan.

Stormwater Drainage

Follow up and control of sludge management in Cali (sludge generated by the different canals).

Expansion of waste water treatment plant, collectors and sanitation interceptors, rainfall canals and collectors, secondary networks, study designs, consultancy.

Surface water - Urban drainage Develop and implement Sanitation and Discharge Management Plans.

Decrease city flooding and presence of wastewater in the Canals.

Optimize existing separation structures, location and design of new structures.

Treatment and disposal wastewater

Follow up and control of sludge management in Cali (sludge generated by waste water plants).

Waste Water Purification Plant.

Develop and implement Sanitation and Discharge Management Plans

By year 2016, the decontamination goal in the PTAR –C considers a 33% decrease in BOD, 56% in TSS and an affluent water flow of 6.8 m3/s with affluent loads of 96.5 Ton/d of BOD and 78.4 Ton/d of TSS.

It is expected that by 2016 the Southern PTAR will have started operations with 80% BOD removal efficiency and 85% for TSS, an affluent flow of 20 L/s with loads of 0,26 Ton/d for BOD and 0,19 Ton/d for TSS.







Discharges (PSMV) Plan for the development of Cali (PDC)

Solid waste management

Follow up the final closure of the Navarro Dump.

Debris management and control in Cali.

Final closure of the Navarro disposal site.

Implementation of PGIRS with participation of regional actors

Domiciliary solid waste management

Debris Management - Use and final disposal



Support and management of the proposed Departmental Water and Basic Sanitation plan.

Implementation of the source separation culture

River basin

Proposal and application of the management and development plans for the Cauca, Pance, Lili, Melendez, Cañaveralejo, Aguacatal and Cali River Basins.

Proposal and implementation of the recovery plan for the city wetlands (Charco azul, Lago Panamericano and others).

Promote the creation of a user’s network by river basin.

Supply, installation and start up of Cali water network during one year.

Follow up and control of environmental protection areas defined in the POT.

Operation and maintenance of the Municipal Environmental Information System (SIAM).

Ensure the supply and quality of water resources for human consumption and support, articulate and implement actions related to the Department’s water basins integrated management and planning.

Re-management of the basins of the 7 rivers in the city, protection of the upper river basins and recovery of their water quality.

Protection of foothills, mountains and levees. Recovery of the Laguna del Pondaje and Charco Azul

Inventory, characterization, recovery and maintenance of green zones and parks.

* Monitoring, surveillance and control of the status, use and management of natural resources.

Institutional

Develop programs, projects and activities according to identified priorities set in the Land Management Plan of the municipality, promoting proper urban soil use, articulating all public and private institutions, social organizations, the academia and the community, in general

Implementation of PGIRS with participation of regional actors

Proposal for the new Land Management Plan. Propose a plan for entrepreneurial management of water and basic sanitation services.

Strengthening of the environmental management.

Interinstitutional coordination of environmental surveillance and control.

Promotion of the sustainability culture. Strengthening of participation in environmental management.

Promotion of environmental education.







Discharges (PSMV) Plan for the development of Cali (PDC)

Policies and regulations

Coordination of the application of Article No. 111 of Law 99 dated1993 (Acquisition of areas strategically important for water resources).

Implementation a public space management plan including new orientations and national and international policies framed within a new urban development habitat model

Elaboration of Public Services By-laws. Implementation of environmental surcharge.

Economic Implementation of water resource economic instruments.

Implementation of environmental surcharge.



ANNEX 3 Characteristics of the expansion area in Cali

(Adapted from the Diagnosis report, Universidad del Valle, 2008)

Annex 3 Characteristics of the expansion area in Cali city


A3.1 GENERAL OVERVIEW OF TH RBAN EXPANSION AREAS IN CALI The future urban expansion area in Cali would be located to the south of the city and it is composed by the sectors named: Corredor Cali – Jamundí and Navarro (see Figure A3.1). Regarding the type of urban developments in this area, there is not a general urbanization proposal for either sector. However, in the sector of Cali-Jamundí, individual urbanization proposals are being studied by the Planning Department. These individual proposals are mainly requested by construction companies which have already bought land in the sector and that are looking to develop their own areas.

Figure A3.1 Current and future area distribution in the city of Cali

Source: Municipio de Cali, 1998.

Following, a description of each expansion sector is made with their respective proposed strategies regarding water supply, sewerage systems and wastewater treatment based on studies carried out by EMCALI and private consultancy firms.



A3.2 CALI-JAMUNDÍ SECTOR

A3.2.1 General Characteristics The future urban expansion area defined in the POT (Land ordering plan) as Cali-Jamundí is located to the south of the city and it is formed by 1652,85 hectares. Its topography is uniform with a slight descent slope to Cauca river (see Figure A3.1). Currently, this area is mostly used for agriculture purposes. A3.2.2 Drinking water supply Population density and drinking water supply: There are not norms or legislation that regulate the sector of Cali-Jamundí sector regarding the type of infrastructure, dwellings and urbanization layouts. The gross area of this area is of 1654 ha. Table A3.1 shows the net area of the Cali-Jamundí sector which would receive drinking water and sanitation services and which is divided according to estratos as mentioned before. The distribution of population density proposed in this study (which also follows POT guide lines) are shown in Table A3.2. In this study, year 2030 was taken as the projected year. Table A3.1 Expansion area “Corredor Cali-Jamundí” Estimated drinking water demand in

year 2030 Estrato Area (ha) Demand (l/per/ha)

3 305 2754 528 4175 490 3546 35 21

Total 1358* 1067Source: EMCALI-Hidroocidente, 2005 *Note: The total area calculated in the Table does not include 122 ha from estrato 6 which has been already considered in the Project drinking water supply, Upgrade of the pumping system of High Pance, carried out by Unión Temporal Cali (2004).

Table A3.2 Proposed drinking water demand and population density in the area Cali-Jamundí

Gross demand (per/ha) Gross demand (l/per/ha) Year Estrato 3 Estrato 4 Estrato 5 Estrato 6 Estrato 3 Estrato 4 Estrato 5 Estrato 62010 87 69 56 33 218 240 273 371 2015 134 107 86 52 209 230 261 356 2020 216 172 139 83 206 226 257 350 2025 303 241 194 117 203 224 254 346 2030 390 310 250 150 200 220 250 340

Source EMCALI-Hidrooccidente, 2006

Proposed alternative: Based on Table A3.1, when the expansion sector Cali-Jamundí would be totally developed, its full water demand would be 1067 l/s. From a previous study called “Prolongación de la Tubería de Transmisión Oriental-TTO” or “prolongation of the Oriental transmission pipe TTO” by INGESAM, it was already defined that the TTO would supply the Cali Jamundí sector with a flow of 510 l/s.



Based on these previous conditions, Hidrooccidente proposed the following as the drinking water supply strategy in the sector: The main objective was to supply the expansion area through pumping from Puerto

Mallarino and Rio Cauca drinking water plants, so in place technology was used. Prolongation of the TTS line trough Calle 25 until Carrera 115 Prolongation of TTO through Calle 53 until Carrera 122 Construction of a linking structure between TTO and TTS in Carrera 109 Supply of water by gravity the south area in the Cali-Jamundí sector which is equivalent

to an average flow of 538,95 l/s. Supply of water by pumping the tanks in the south area (Cra 127 and Cra 118) which is

equivalent to 528,07 l/s Table A3.3 shows a summary of the proposed water supply strategy in the Sector Cali-Jamundí.

Table A3.3 Proposed drinking water supply area distribution in expansion sector Cali-Jamundí

Area (ha) Estrato Supply

(l/inhab.d) Density

(inhab/ha) Demand

(l/s) Zone

77,08 5 250 250 55,76 94,46 4 220 310 74,56 82,77 4 220 310 65,33 50,76 4 220 310 40,07

Direct pumping from Puerto. Mallarino & Río

Cauca plants

166,81 5 250 250 120,67 245,27 4 and 3 220 and 200 310 and 390 186,40 Pumping Carrera. 118

317,56 4 and 3 220 and 200 310 and 390 303,21 Direct pumping from

Puerto. Mallarino & Río Cauca plants

33,81 6 340 150 19,96 289,48 5, 4 and 3 250, 220 and 200 250, 310 and 390 201,06 Pumping Carrera. 127 Source: EMCALI-Hidrooccidente, 2006

A3.2.3 Sewerage system Wastewater characteristics The production of wastewater per person was estimated using a return coefficient of 0,80 applied to the drinking water demand. Table A3.4 shows the estimated wastewater production during the period 2010-2030.

Table A3.4 Wastewater production period 2010- 2030 Wastewater production (l/per/day) Year Estrato 3 Estrato 4 Estrato 5 Estrato 6

2010 174 192 218 297 2015 167 184 209 285 2020 165 181 206 280 2025 162 179 203 277 2030 160 176 200 272

Source. EMCALI-Hidrooccidente, 2006.



Likewise, the BOD and SST concentrations of the wastewater in this area were estimated as 157 mg/l and 113 mg/l respectively. These concentrations represent the typical domestic wastewater concentrations in Cali based on measurements registered in the Collector Margen Izquierda (EMCALI, 2007). Design Flows: Apart from the wastewater flows estimated in Table A3.4, the following flows were also taken into account in the design of the sewerage system: - For options that considered separate sewerage systems, an additional wastewater flow

of 0,1 l/s.ha that considers illegal storm water connections was included. - Superficial Infiltration flow in the collectors joins of 0,115 l/s.ha was also considered. Proposed alternatives: The draining of the wastewater produced in the area of Cali-Jamundí, whether combined or separate system, would be done using secondary collectors which would be placed in the future roads located in East-West direction. The principal collectors would be placed in the roads located in South-North direction which would convey wastewater to the proposed WWTP-Sur which could be located in front of the current solid waste disposal site of Navarro along the left side of South channel. Cali-Jamundí area was divided in four drainage sectors according to the sewerage system. Such sectors were named Sector 1, 1A, 2 and 3 (See Figure A3.2).





Figure A3.2 Proposed drainage Sectors in the are Cali-Jamundí.

Source: EMCALI-Hidrooccidente, 2006



The different sewerage alternatives proposed by Hidrooccidente are summarized in Table A3.5.

Table A3.5 Summary of proposed sewerage system alternatives. Expansion Area: Cali, Jamundí

Alternative Description Alternative 1 Separate system Wastewater

− Sectors 1, 1A (332 ha) drain by gravity a flow of Q=427 l/s to WWTP-C via Pance

collector. − Sectors 2 and 3 drain by gravity to the future south pumping station (Q=1034 m3/s).

Storm water − Sectors 1, 1A, 3 and part of 2 drain by gravity to Líli, Pance and Jamundí rivers. The remaining part of zone 2 drains to South channel

− Construction of pumping station with capacity 5.7 m3/s to drain 90 ha from zone 2. − Modeling simulations shown that Líli river has to undergo a hydraulic improvement to be

able to transport storm waste Alternative 2 Combined system Wastewater − Sectors 1, 1A (332 ha) drain by gravity a flow of Q=427 l/s to WWTP-C via Pance

collector. − Construction of pumping station in calle 48 with carrera 102 to drain wastewater coming

from zone 1 to WWTP-C. − Sectors 2 and 3 drain by gravity to the future south pumping station (Q=1034 m3/s).

Storm water

− Sector 2 is pumped to South channel (Q=8 m3/s), as well as 87 ha from zone 3 which would be pumped to the channel located in Calle 60-Carrera 102 (Q=5.1 m3/s). .

− Sectors 1, 1A and a big part of zone 3 drain to Líli, Pance Jamundí rivers and South channel.

Alternative 3 Separate and combined system Separate system

Wastewater: − Sectors 1, 1A (332 ha) drain by gravity a flow of Q=427 l/s to WWTP-C via Pance

collector. − Sector 2 drains by gravity to the future South pumping station (Q=1034 m3/s). Storm water: − Sectors 2 must be pumped to South channel (Q=5,7 m3/s), as well as part of sector 3

which would be pumped to the channel located in Calle 60-Carrera 102 (Q=5.1 m3/s). Combined sewerage

Sector 3 is design solely as combined system which drains to the collector which arrives to future Sur pumping station

Alternative 4 Separate and combined system Separate system

Wastewater: − Sectors 2 and 3 are under flood risk so they have separate system, draining wastewater to

future Sur pumping station Storm water: − Sector 2 drains stormwater by gravity to Líli, Pance and Jamundí rivers. The remaining

part of zone 2 drains to South channel − Sector 3 drains store water by gravity to the channel located in Calle 60-Carrera 86.

Combined sewerage

Sector 1 drains the combined wastewater to Pance collector until WWTP-C.

Source: Adapted from EMCALI-Hidrooccidente, 2006 Selected alternative: In its final recommendations, the firm Hidrooccidente stated the following:



The most appropriate option should include separate sewerage system in sectors 1 and 1A which would drain by gravity their wastewater to the WwTP-C to take advantage of its total capacity.

Sector 2 presents risk of flooding. If the system is separate there is the need of pumping 47% of the rainwater that falls in the drainage area and if the system is combined 100% of the rain water needs to be pumped. Therefore it is suggested the implementation of a separate system in that sector.

Sector 3 presents 87 ha which are under flood risk as well (nearby South wastewater pumping station). Hence a separate system must be implemented in this sector as well.

A3.2.4 Wastewater Treatment Proposed alternatives: Table A3.6 shows the summary of the proposed wastewater alternatives.

Table A3.6 Proposed wastewater treatment alternatives in Cali-Jamundí area General description Components

Alternative 1. Pumping to WWTP- − Construction of pumping station in front of Navarro

disposal site to transport wastewater (WW) generated in Cali-Jamundí sector to existing Navarro pumping station

− From Navarro station WW is pumped to WWTP. − An independent boost pipe is projected to convey the

WW generated in the city to WWTP-C − WWTP-C in year 2030 is able to treat 7,28 m3/s

N/A

Alternative 2. Activated sludge* − WW generated in Cali-Jamundí are conveyed to

WWTP-Sur, in front of current Navarro disposal site − Due to the elevation levels of the sanitary collectors , a

screw-type pumping station needs to be built (1470 l/s)

− 1 Screw-type pumping station − 3 fine screen channels − 3 aerated grit chambers − 2 primary settling tanks − 4 aeration tanks − (Q=1061 m3/s) − 2 Secondary settling tanks − Denitrification with ferric chloride − 2 sludge digesters − 2 sludge storage tanks − 2 Filters press

Alternative 3 UASB + show rate activated sludge* − WW generated in Cali-Jamundí are conveyed to

WWTP-Sur, in front of current Navarro disposal site − Due to the elevation levels of the sanitary collectors , a

screw-type pumping station needs to be built (1470 l/s)

− 1 Screw-type pumping station − 3 fine screen channels − 3 aerated grit chambers − 6 UASB − 8 aeration tanks − 8 Secondary settling tanks − Denitrification with ferric chloride − 6 anaerobic sludge storage tanks − 5 Filters press



Table A3.6 Proposed wastewater treatment alternatives in Cali-Jamundí area (cont.) General description Components

Alternative 4 UASB + aerated ponds* Same as alternative 2 − 1 Screw-type pumping station

− 3 fine screen channels − 3 aerated grit chambers − 6 UASB − 3 aerated ponds and 1 anoxic pond (Phase I) − 3 Settling ponds − 3 aerated ponds and 1 anoxic pond (Phase II) − 3 Settling ponds − 2 anaerobic sludge storage tanks − 2 Filters press

Source Adapted from EMCALI-Hidrooccidente, 2006 *Design flow of the systems (Q) =1,061 m3/s. Technology Selection: The process of selection of the most appropriate technology was based on a technical, economical, and environmental assessment. Technical assessment: Table A3.7 describes the parameters considered in the technical evaluation of the proposed wastewater treatment technologies.

Table A3.7 Technical evaluation of technologies.in Cali-Jamundí area Infrastructure Advantages Observations

Screw-type pumping station

Required in alternatives 2, 3 and 4. It keeps the same design characteristics in all alternatives

Pumping station to Navarro pumping

station

It is required in alternative 1. The pump type would be centrifuge.

Navarro pumping station Current infrastructure is used

WWTP-Sur

− It allows the exclusive treatment of wastewater produced Cali-Jamundí sector

− The different alternatives foreseen three type of technologies:

Alternative 2 Conventional activated sludge system Alternative 3 UASB system plus low rate activated sludge system Alternative 4 UASB system plus aerated lagoons

− High phreatic levels in the sector made compulsory the use of piles as foundation structures and to raise the land level for the implementation of the slopes of the ponds

− The final effluent disposal alternatives fore sought are in summary: discharge to wetlands and discharge to south channel. Such alternatives are not favorable since either way suggest the wastewater discharge upstream the water intake of Puerto Mallarino.

WWTP-C Current infrastructure is used. In addition, only an investment in the upgrade of the plant to secondary treatment is estimated

Source Adapted from EMCALI-Hidrooccidente, 2006 Economical assessment: The economical assessment was based on the investments costs, operational and maintenance costs of the components of the different proposed alternatives.



Table A3.8 shows the description of the components based on the economical assessment. For the purposes of this report, it was not considered the need to include money value of each component, but rather the final considerations of the report. Therefore, after economically analyzing each alternative, Hidrooccidente suggested that the least costly alternative was alternative 1, followed by alternative 4. Alternatives 2 and 3 were the most expensive ones.

Table A3.8 Economic assessment of the wastewater treatment alternatives in the sector Cali-Jamundí

Investment costs Operation and maintenance costs Alternative 1. Pumping to WWTP-C − Pumping station (PS)to puma water to Navarro

pumping station (PS1) − Replacement of pumping equipment in PS1 − Boost pipe line from PS1 to WWTP-C − Secondary treatment in WWTP-C (flow from

expansion area). − Replacement equipment in WWTP-C − Secondary thickener WWTP-C (flow from expansion

area).

− Energy PS − Energy PS1 − Operation and maintenance WWTP-C − Maintenance boost pipe line from PS1 to

WWTP-C

Alternative 2. Activated sludge − WWTP-Sur construction − Construction pumping station entrance to WWTP-Sur − Replacement of pumping equipment in WWTP-Sur − Replacement equipment in WWTP-Sur

− Operation and maintenance WWTP-Sur − Energy pumping station entrance to WWTP-

Sur

Alternative 3 UASB + show rate activated sludge − WWTP-Sur construction − Construction pumping station entrance to WWTP-Sur − Replacement of pumping equipment in WWTP-Sur − Replacement equipment in WWTP-Sur


Sur

Alternative 4 UASB + aerated ponds − WWTP-Sur construction − Construction pumping station entrance to WWTP-Sur − Replacement of pumping equipment in WWTP-Sur − Replacement equipment in WWTP-Sur


Sur

Source Adapted from EMCALI-Hidrooccidente, 2006 Environmental assessment: The critical points to analyze each alternative from the environmental point of view were (EMCALI-Hidrooccidente, 2006): To avoid increasing the pollution to South channel known also as Navarro channel The WWTP-Sur may strengthen the current characteristic of the sector as a sanitary

polygon based on the presence of south channel and Navarro solid waste disposal site The WWTP-Sur causes devaluation of the surrounding terrains Using WWTP-C ensures the use of infrastructure already in place which currently is

being underused Using WWTP-C is more advantageous since the technology is already known



UASB technology is a non proved technology since its real efficiencies are still under discussion. Additionally, there are no UASB technologies with similar size as the WWTP-Sur would be so there is no option for comparison.

It is not advisable that EMCALI uses its resources in the implementation of not proved technologies, even more, when there are conventional technologies which have been tested and proved worldwide. Furthermore, EMCALI has experience in the design and operations of conventional plants as WWTP-C.

UASB alternative is an uncertain investment for EMCALI, which is not compatible with the type of urban development wanted for the area which in addition causes high environmental impacts.

Selected technology: Based on the assessment described above, Hidrooccidente recommended the alternative 1 as the most appropriate technology in the expansion area Cali- Jamundí.



A3.3 NAVARRO SECTOR

A3.3.1 General characteristics According to the POT, the area defined as “regimen diferido Navarro” is not directly included within the established areas for future urban development. However, the POT states that the area may be used in a future as an urban development sector provided that urbanization and environmental studies say so. Currently, the municipality of Cali has selected this area as urban development for the “estratos” 1 and 2 ( Gandini & Orozco, 2006). This zone is located to the south of the city in the area called Navarro. It boundaries to the north is the urban perimeter, to the south is the South channel, to the east is the protected green belt and to the west is the polygon that defines the environmental protected area around Cauca river. In this area, the solid waste disposal site of Navarro is located. The total area of the Navarro sector is 823,74 hectares, from which 615,52 ha are designed to be urbanized and 196,6 ha correspond to the so called “ejidos municipales” which mean areas of communal property. The soils in the sector are adapted for agriculture and cattle breeding, being the main crops the re sugar cane one. For the implementation of water supply and sewerage systems in this sector, EMCALI hired the consultancy firm Gandini and Orozco to make the feasibility studies for the delivery of such services. Therefore, all the information described in the sector of Navarro corresponds to the study carried out by Gandini and Orozco (2006). It is important to highlight that in the study, Gandini and Orozco point out the lack of a defined urbanization scheme by the Municipal planning department. Consequently, the consultancy firm proposed a road layout to locate the water supply and sewerage pipes. A3.3.2 Drinking water supply Population density and drinking water suplí: For the estimation of the population growth, the firm estimated a growth that is defined in Table A3.9. The saturation density of 500 inhab/ha was based on the population growth estimated in the POT in estratos 1 and 2 in the current city (486 to 507 inhab/ha) arriving finally to a saturation population of 307760 inhabitants.

Table A3.9 Estimated population growth and drinking water demand in the Sector of Navarro

Population in Navarro (inhab) Total demand Year Annual

Increment Total

Population l/s m3/year

2010 12000 12000 25,0 779 2020 6000 96000 200,46 6235 2030 6000 156000 325,74 10131

Source: Adapted from: Gandini & Orozco, 2006



The base average water consumption was 140 l/inhab/day which corresponds to the monthly average consumption in estratos 1 and 2 in the current city of Cali in year 2005. The non-domestic consumption was estimated as 3% of the total consumption. The water losses were estimated as 25% of the total. The projected water demands are shown in Table 8.10. For the study of the drinking water and sewerage systems alternatives, the sector of Navarro was divided in North sector (389,7 ha) and south sector (423,5 ha). For purposes of the study it was assumed that the total estimated population in year 2030 would be located in the north sector. Proposed alternative: Table A3.10 shows the design criteria used in the proposal of the drinking water supply alternatives.

Table A3.10 Design criteria for the proposed in drinking water supply alternatives

Supply with losses of 25% 187 l/inhab.d Maximum daily consumption factor 1,20 Maximum hourly consumption factor 1,50 Hourly maximum flow 1200 l/s Average flow 666 l/s Daily maximum flow 800l/s

Source: Adapted from: Gandini & Orozco, 2006

A3.3.3 Sewerage system Wastewater characteristics: The return flow was established as 0,85 from the drinking water consumption. The design flow for the pre-design of the sewerage network was assumed at 1,5 l/s. The storm water flows were estimated using the model EPA-SWMM-V-5.0. The following were the considered parameters for the proposed design of the sewerage systems: - Average WW Q = 423,52 l/s - Infiltration Q = 110-7 l/s - Illegal connections Q = 61,50 l/s - Maximum hourly WW Q = 669,48 l/s - Rain Q = 46288,65 l/s Proposed alternatives: The proposed alternatives for the sewerage networks were classified as separate and combined sewerage systems varying the materials of the transport pipes from PVC to concrete. In overall the alternatives were classified according to Table A3.11. Selected alternative: The consultancy firm left the decision of the preferred alternative to EMCALI.



Table A3.11 Alternative proposed scenarios for the sewerage systems in the Navarro sector Alternative Scenarios

Alternative 1: Separate sewer

system

Sanitary sewers 1A. PVC network pipes, pumping to Aguablanca Pumping Station (ABPS),WWTP-C and discharge to Cauca river. 1C. PVC network pipes, pumping to proposed WWTP-Navarro and pumping to Cauca river. 1B. Concrete network pipes, pumping to ABPS, transport to WWTP-C and discharge to Cauca river. 1D. Concrete network pipes, pumping to proposed WWTP-Navarro and pumping to Cauca river. Storm water In all scenarios storm water will be convey to Cauca river.

Alternative 2: Combined

sewer system

2A. Combined network pipes, pumping to ABPS, WWTP-C and discharge to Cauca river. 2B. Combined network pipes, pumping to proposed WWTP-Navarro and pumping to Cauca river. For both alternatives the use of CSOs in contemplated with transport of excess rain water via open channels and their direct discharge to Cauca river. 3A. Combined network pipes, pumping to ABPS, WWTP-C and discharge to Cauca river. 3B. Combined network pipes, pumping to proposed WWTP-Navarro and pumping to Cauca river. For both alternatives the use of CSOs in contemplated with transport of excess rain water via closed pipes and their direct discharge to Cauca river.

Source: Adapted from: Gandini & Orozco, 2006 A3.3.4 Wastewater treatment Proposed alternatives: There where different proposed systems for the treatment of wastewater in the sector of Navarro. The design criteria were determined using year 2030 as the projected year. The design parameters are the following: COD=380 mg/l BOD=200 mg/l TSS=200 mg/l Inhabitants=156000 Return coefficient 0,85 Drinking water supply = 140 l/inhab/day Maximum Flow = 540 l/s Average Flow = 300 l/s

Selected alternatives: Table A3.12 shows the alternatives proposed. The study made use of an economical assessment in order to classify the technologies according to their investment, operation and maintenance costs. From such classification, the least costly option was alternative 3, followed by Alternative 1 and afterwards Alternative 2. Moreover, between alternative 1 and 2, the less expensive alternative was number 1: UASB + aerated pond + high rate settling The effluent final discharge from the WWTP-Navarro would be



Cauca river in case its construction is finally decided. Disinfection would be applied to the effluent before it is discharged to Cauca river.

Table A3.12Components of proposed wastewater treatment alternative systems in the Navarro sector

Pre-treatment Alternative 1 UASB +

aerated ponds+ high rate settling

Alternative 2 UASB + percolation filter+ secondary

settling tank

Alternative 3 Conveying and pumping to WWTP-C

− Gross screens − Solid waste

storage tank (0.08 m3 )

− 3 horizontal flow grit removal chambers (150 l/s)

− Sand storage tank

Total area =2.6 ha UASB − 4 reactors :75 l/s each − HRT:6 hours − Depth: 4m − Width 25 m − Length:16 m − BOD removal efficiency

60% − Sludge production 1l/m3

− 3 sludge dry blankets per reactor

Pond − 1pond − BOD removal

efficiency: 70% − Water volume 536 m3

Total area = 2.2 ha UASB Same as alterative 1. Aerobic percolating filter − 4 filters − BOD removal efficiency:

70% − Volume: 1016 m3 − Area 508 m2 High rate secondary settling tank − HRT: 3 h − 4 modules :75 l/s

− Navarro’s wastewater pumped to Aguablanca pumping station and afterwards to WWTP-C

− WWTP-C design flow of 7.6 m3/s would be reached in 2030 according to Gandini & Orozco. Other EMCALI studies suggest that the design flow would be reached in year 2017.

− Possibility of implementation of aerobic ponds as secondary treatment in WWTP-C to reach BOD removal of 80%.

Proposed Options within alternative: o WWTP-C +ponds +

parallel plates until 2017.

o WWTP-C until 2030 o WWTP-C until 2017

Source: Gandini & Orozco , 2006.

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