City of Amsterdam adaptive reuse project contest to turn two abandoned sewage treatment silos.http://www.inhabitat.com/2009/05/07/abandoned-silos-transformed-into-a-climbing-gym/http://architecturelab.net/2009/04/15/schmidt-house-competition/

Perspective:– Silos exist in our Clean and Safe Water industry. We tend to be conservative and think within our “fences”. However, we were once “big” picture planners and implementers. To be sustainable – we need to break these silos.

What we know from the “Clean Water”industry perspective (1)

� Recognition of scarcity of resources – especially water

� Growing awareness of interdependences between energy, water, air, climate, land

� Water – Energy nexus, increasing pressure on water supply and energy production

� Growing pressures to reduce concentrations and quantities in permitted effluent discharges

� Energy assumptions (esp. aeration efficiency + source of electricity) & sludge disposal make big difference in GHG & carbon footprint

� Consensus lacking on amounts and effects of N2O and CH4

� Increasing opportunity for conservation and renewable energy – inc. wastewater as a resource

� Work by Utilities, Scientists, Consultants, Industries, et al increasingly focused on above

What we know…(2)

� Carbon footprint = total amount of CO2 and other greenhouse gases emitted over the full life cycle of a product or service. (United Utilities, UK)

� Direct emissions from WWTP may represent less than 1% of global emissions (Suez, et al, 2007)

� Current technologies can get to TN of 3.0 mg/L and TP of 0.10 mg/L respectively (05-CTS-1W, other meetings)

� Energy use accounts for one-third or more of WWTP total cost, second only to labor costs

� In the USA, the wastewater industry uses 21 billion kWh/year or ~3% of all electric power generated (W103 WEFTEC 2007, WERF Web Seminar, 2008)

� Opportunities exist to reduce, even produce, energy with wastewater

� Public (and regulators) seeking to be better informed

Carbon Footprint & GHG

� Carbon footprint estimates have uncertainties between methods of 10 to >100% (Russo, D., per comm, various sources in WEF Sustainability Conf 2008)

� Carbon footprint from WWT dominated by imported power (electrical), followed by fugitive emissions of N2O (Russo, D.; Finch, R; others, per comm)

� N2O and CH4 from biosolids disposal may have similar or as much as 5 times the footprint as N2O emissions from N/DN

� Construction phase (embedded) carbon footprint typically accounts for <15% of the total C footprint over the 15-year life of a WWTP

� Using Life Cycle analysis, MBR WWTP can have higher costs than traditional activated sludge configurations due to higher power and chemical consumption (no fugitive gas emissions included in footprint)

� WWTP using primary sedimentation and anaerobic digestion (even with extended aeration BNR processes) may be better option to reduce GHG emissions as the offset from onsite power generation using renewable energy lowers carbon footprint by 20 – 40%.

Various sources inc. WEF Sustainability Conf 2008

Carbon Footprint & Wastewater

� Need for more published, peer reviewed information.

� Standardized approach to calculate carbon footprints needed� Until then, more reliable to perform comparative footprint analysis. Degrees of

uncertainties may be minimized when comparing different scenarios to an existing initial scenario. Can quantify with a higher degree of certainty that the carbon footprint difference between scenarios A and B is XX%.

� Assumptions about energy (aeration efficiency in particular) and the disposal of biosolids or sludge make a big difference.

� Some software tools for detailed calculation of absolute-value C-footprint exist –require expert investigator and boundary assumptions for the analysis. (above from Russo, D., and Stenstrom, M – per comm.)

� Essentially every energy production method generates CO2 at some level. Estimates of C footprint related to nuclear (concrete, steel, construction, fuel cycle...), PVs (manufacturing), and hydro (methane production from impoundments) available. (Finch, R., per comm)

Additional Work…

� Detailed greenhouse gas emissions estimate associated with reducing effluent phosphorus limits from 200 µg/L to 70 µg/L� Increase in GHG emissions is ~3,300 – 4,100 metric tons CO2

� Brown and Caldwell, for City of Boise, ID (June 2008)

� Carbon-sequestration potential of wastewater treatment� Proper WWT reduces GHG emissions. Full WWT w/ biomass sequestration and biogas energy recovery can be a net carbon sequestration process� D. Russo & M. Stenstrom, Chemosphere 70 (2008) 1468 – 1475

� Carbon-sequestration potential of biosolids land application� Ongoing studies by DCWASA, UKWIR, other agencies

� Comparative footprints of conventional activated sludge vs. nitrification and N / DN processes� D. Russo & M. Stenstrom, et al

� Other researchers

Footprint issues – Technology is part of solution

Footprint of facility – process tanks, equipment, energy

http://www.wastewaterhandbook.com/webpg/th_integration_102optimized_design.htmHandbook Biological Wastewater Treatment - Design of Activated Sludge Systems

Technology helps… But footprint increases

Footprint of facility ▲ process tanks ▲, equipment ▲, energy ▲

Technology gets more complex. As does the Footprint

Footprint of facility ▲ process tanks ▲, equipment ▲, energy ▲

Additional P removal – chemical use ▲, biosolids volume ▲

GHG: CH4, NO, N2O, NOx, etc.� Methane (CH4) and other gases, VOCs, from collection systems / sewers, and digestion processes may contribute to GHG

� Several BNR facilities operate at low DO concentrations (0.1 – 0.3 mg/L) &/or remove nitrogen via nitrite, to minimize energy for nitrification and supplemental carbon for denitrification.

� Increasing recognition that BNR operations could result in production of gaseous oxidized nitrogen compounds, such as nitric oxide (NO), nitrous oxide (N2O) and to a lesser degree nitrogen dioxide (NO2).

� GHG impact of N2O ~300x impact of CO2.

� NO converted to NO2 in atmosphere – primary constituent of orange smog during peak air pollution events in urban areas.

GHG: Climate Change Potential� Key greenhouse gases from wastewater treatment are

methane and N2O.� Methane has 21 times and N2O has 310 times the

warming potential of CO2.

US Greenhouse Gas Annual Emissions

(TG CO2 Equivalents)

1

10

100

1000

10000

Fossil Fuel Co...

Misc. Agriculture

Landfills

Cement M

anufa...

US Wastewater...

All Other Sources

Climate Change considerations

Source: CH2M-Hill and LACSD

GHG Emitted Nationwide – All Sources

Est. Nitrous Oxide GHG from Wastewater

Source: CH2M-Hill and LACSD

Energy and Water are ….. Interdependent

Water for Energy and Energy for Water

Energy and

power

production

require water:• Thermoelectric cooling

• Hydropower• Energy minerals extraction/mining

• Fuel Production (fossil fuels, H2, biofuels)

• Emission control

Water

production,

processing,

distribution,

and end-use

require energy:• Pumping• Conveyance and Transport

• Treatment• Use conditioning• Surface andGround water

Ray Ehrhard, Global Energy Partners, in W103, WEFTEC 2007

Electricity Requirement for Typical Activated Sludge Facilities

WEF, SAIC, EPA various sources

Work Overseas.…

� University of Queensland Advanced Water Management Centre completed comprehensive report on extent of knowledge on fugitive greenhouse gas emissions from wastewater systems in Australia (Foley and Lant, 2007).

� Three major knowledge gaps in the field of fugitive greenhouse gas emissions from wastewater systems identified:

� Potential for methane formation in anaerobic wastewater transferand collection systems; and associated concentration of dissolved methane, in all low-strength anaerobic processes;

� Nitrous oxide emissions from different types of “advanced”biological nitrogen removal processes; and

� Nitrous oxide emissions from effluent discharges to specific riverine, estuarine and oceanic environments.

� Work also underway in the Canada, Netherlands, UK, France, etc

What We Don’t Know

� What’s the “best” nutrient removal with the least energy use and least global warming impacts. Need to define “best”, issue of performance reliability, site specificity, costs, etc.

� What’s the carbon footprint and energy requirements for conventional WWTPs and those that treat / remove nutrients? Need to develop standardized methods/guidance and collect more information.

� Lack of (and therefore need for more) information on embedded concrete, energy requirements, chemicals needed, air emissions (NOx, methane), residuals/sludge (transport, etc.).

What is WERF doing

� Program-Directed Research

� Transitioned from “projects” to “challenges”

� Greater Collaboration – US and overseas

� Global Water Research Coalition

� Specific joint projects

� “Knowledge Areas” – website

� More tech. transfer, outreach

What is WERF doing… (2)� Nutrient Removal

�Providing recommendations to improve sustainable wastewater nutrient removal technologies and for achievable regulatory limits

� Operations Optimization�Exploring processes to reduce energy use, costs and the environmental footprint of wastewater treatment.

� Climate Change�Evaluating likely effects of climate change on wastewater services and assessing mitigation and adaptation options.

� Decentralized Systems� Improve capacity to respond to increasing complexities of, and expanding need for, decentralized wastewater and stormwater, as part of an integrated water management approach.

Energy and Resource Recovery from Wastewater Residuals (OWSO3R07)

� State of the Science ReportProvide status of current knowledge on energy and resource recovery from sludge

� Inform GWRC workshop on Water and Energy February 2008

� Identify research needs and knowledge gapsHugh Monteith, et al, Hydromantis, Inc.

Energy and Resource RecoveryCurrent Status

Average Electric cost (US $/kWH) $0.14 $0.12 $0.09

Energy used for WWT (Billion kWH/year) 0.7 3.7 21

Energy kWh used / M3 treated0.355 0.628 0.453

Carbon footprint (Tg CO2 equi/year) NA 4 33.4

Percentage of digester gas used for heat and power NA NA 34%

NL UK USA

Products Recoverable from Wastewater Residuals

Type of Product Use of Product

Methane Electricity, heat, fuel

Gases Electricity, heat

Oil, fat, grease Biodiesel, methane

Phosphorus Fertilizers

Nitrogen Fertilizers

Metals Coagulants

Inorganic Materials Building Materials

Inoculum Bio-hydrogen gas production

Crystal proteins, spores Bio-pesticides production

Organic compounds Organic acid production

Energy and Resource Recovery from Sludge

� Recommendations:

� Apply a new framework for cradle-to-grave (cradle-to-cradle) optimization for overall net environmental benefits

� Promote recovery of energy, elements and water

� Agree upon standard metrics and calculations for carbon footprint, carbon offsets, greenhouse gases, etc.

Bottom Line – “Used” Water (Wastewater) is a Resource

� Opportunities abound• Reclaimed or “New” Water

• Biogas production with co-generation of heat and energy

• Imbedded energy in sludge for fuels

• Imbedded energy in wastewater

• Extraction and reuse of constituents – inc. nutrients

What’s the value & the market?

What can we “mine” and How?

“New” Water

Energy

Nutrients

Metals

“Used” Water

Others?

Various Technologies(current and future)

Also, discuss examples of

Singapore PUB, Water Hub,

Marina Barrage, NEWater

Stormwater is a Resource too!http://www.werf.org/livablecommunities/

Sustainability Best Practices Technology Roadmap for WWTP in Carbon-constrained world

� Collaboration with GWRC

� 2040 goal for domestic wastewater treatment to be 100% self-sustainable

� Low to none fossil-fuel based energy requirements

� Minimized carbon footprint

� International expert involvement and direction on pathway to meet goal

Sustainability Best Practices Energy Efficiency: A Compendium of Tools, Best Practices and Case Studies

� Collaboration with GWRC and the UK Water Industry Research (UKWIR)

� Develop a Compendium of best practices for energy efficient design and operations

� WERF leading the research contribution from the North American sector

Operations Optimization – New Projects:

� Case Study Demonstrations of Energy Efficiency Best Practices

� Life-cycle tool for green energy options

� Assessment of Carbon Footprint of Biosolids Management Options

� Evaluate Sludge Gasification / Syngas technologies

State of the Science Review to Manage GHG Emissions

� GWRC effort lead by WaterRF

� Review of process models and indicators

� Synthesis of methods and models to calculate carbon footprint

� Identification of gaps and research needs

GHG Emissions Characterization - WERF

Kartik Chandran, Columbia Univ.

� Characterize oxidized nitrogen GHG emissions from BNR facilities – nitrification / denitrification pathways

� Develop, calibrate, and validate model for N2O production based on fundamental biochemistry

John Willis, Brown and Caldwell

� Measure CH4 emissions from WWT and conveyance systems

WERF

UKWIR

WaterRF

GWRC

•State of science review for process models to manage energy and emissions

•Energy efficiency in the water industry; tools, best practice and case studies

•Vulnerability assessment and associated risk management tools

•Infrastructure planning to adopt cost-effective response to climate change

•A “buyers guide” to climate risk for water utilities

•Climate change impacts on soils and underground infrastructure

•Framework for understanding climate change impact on river and drinking water quality

•Guidance document on carbon trading for the water utility sector

•Regulatory barriers to sustainable water / wastewater industry

•Green energy life cycle assessment tool

•N2O emissions

Collaborative climate change researchNot just WERF

2007 WERF Research Forum Panel:

Future Approaches to Wastewater and Stormwater Management

� Decentralized water management systems will become increasingly attractive because of their ability to enable water reclamation and reuse.

� Distributed stormwater treatment is likely to become the norm.

� The concept that all treated effluents should be discharged to surface water will probably turn into an anachronism. Water reclamation, reuse, and recycling are likely to become the norm.

� The future will require more than traditional approaches to urban water management.

NDWRCDPNational Decentralized Water Resources

Capacity Development Project

• WERF is currently administering an EPA-grant funded research program on decentralized systems.

• Mission: To improve the capacity of public and private entities to respond to the increasing complexities of, and expanding need for, decentralized wastewater and stormwater systems through identification and support of research and development.

NDWRCDP Partners

Coalition for Alternative

Wastewater Treatment

NDWRCDP Research Areas

� Environmental Science and Engineering

� Management and Economics

� Regulatory Reform

� Training and Education

� 35+ projects valued at $8 million

� All products available through www.werf.org or at www.ndwrcdp.org

What’s needed

� Longer term, collaborative solution needed:� It’s Not:

� Add another advanced treatment process� The same level of resources and thinking� Antagonistic relationship among clean water “stakeholders”

� It Is:� Sustainable Partnership� Investment for the Future� Break down Silos� Think holistically and beyond the perimeter

� Additional considerations:� Education Research “Aging” Infrastructure � Training “Aging” Population & Workforce� Think “Big” – Plan Well Ahead

For additional information, contact:

Amit Pramanik, PhD, BCEEMapramanik@werf.org

Lauren Fillmorelfillmore@werf.org

Jeff Moeller, P.E.jmoeller@werf.org

Ph: (703) 684-2470

Water Environment ResearchFoundation635 Slaters Lane, Suite 300Alexandria, VA 22314www.werf.org