際際滷

際際滷Share a Scribd company logo

Urban Sanitation, Wastewater And Climate Change

M
mredwood

Urban planning has failed to properly address urban sanitation and wastewater reuse in agriculture. Key issues driving increased wastewater reuse include water stress from climate change, population growth, and failures in sanitation coverage. Traditional urban planning has aimed for high-tech, high-cost solutions and failed to consider operation and maintenance. Better approaches include following ecological planning principles, designing systems based on downstream reuse ("reverse water chain"), and setting appropriate health-based wastewater treatment targets according to WHO guidelines. With the right planning, policies, and engagement of stakeholders, wastewater can be safely reused in agriculture.

1 of 26
Urban Sanitation and Wastewater Reuse in Agriculture An Urban Planning Perspective Mark RedwoodProgram Leader, ClimateChange and WaterInternational Development Research Centre
Outline of PresentationIDRCDrivers of wastewater useIllustrations of wastewater use in citiesTheproblemwithurbanplanningWhat can be done?
IDRCCreated by Canadian Parliament in 1970
International Board of Governors
Research in developing countries to promote growth and development
IDRC workonwastewatergoes back to 1998
Partners in thisworkinclude at least 15 researchinstitutions
WHO, IWMI, FAO, World BankDrivers of Wastewater UseWater stress and climatechangeUrbanization, populationgrowth and foodinsecurityFailure of sanitation
Water stress isontheriseSources: Comprehensive Assessment of Water Management in Agriculture 2007; and UN Department of Economic and Social Affairs 2008
Source: IPCC, WG2, 2008Examples of freshwater stress associatedwithclimatechange
Increasing water scarcity combined with increased food demand and/or water use for irrigation as a result of higher temperatures are likely to lead to enhanced water reuse. Areas with low sanitation coverage might be found to be practising (as a new activity or to a greater degree) uncontrolled water reuse (reuse that is performed using polluted water or even wastewater).Source: p. 70, WG 2, IPCC 2008
UrbanizationSource: UN Habitat 2008
Source: ProgressonDrinkingWater and Sanitation - WHO UNICEF 2008
Le Caire (gypte)
Nouackchott (Mauritanie)
Mark Redwood - PUREWastewaterPipe water
Mark Redwood - UPEButpeople can be at riskwhenconsumingproductsirrigatedwithuntreatedorpartiallytreatedwastewater. KAMPALA EDIBLE LANDSCAPE PROJECT
Source: World Bank 2010
PlanningFailuresTendency to aim for high-tech, high-cost skipping steps in the sanitation ladderOperation and maintenance the inability to recover costsPolitical stasisTraining for planners has its limits there are conventions (and sometimes for good reason!)
Whatisrequiredtochangehowwe plan and managewastewaterforreuse?
FiveStepsThat Can Make a DifferenceRemindourselves of the ecological basis of planningReverse thewaterchainwhenwe plan and designSet anappropriatehealth-based target (2006 WHO Guidelines)Revitalize and enforce rules aboutwhatentersthesystemRecognizetheintrinsicvalue of wastewater
(1) Key EcologicalPlanningPrinciplesFacilitate natural processMinimizecarbon and energycostWastewatermanagementthatenhancesenvironmentUnderstandthecosts and benefitsRecognizeeconomicvalue of wastewater(FAO)
(2) Reverse WaterChainApproachMake design decisionsbased on the actual and potentialreuse of wastewater
Effluent quality fixed by the required water characteristics in downstream irrigation
The location of a treatment plant in relation to the agricultural field and additional fresh water resources
Decentralization in view of cost reduction and the exclusion of toxic waste streams in the sewerage

More Related Content

Urban Sanitation, Wastewater And Climate Change

  • 1. Urban Sanitation and Wastewater Reuse in Agriculture An Urban Planning Perspective Mark RedwoodProgram Leader, ClimateChange and WaterInternational Development Research Centre
  • 2. Outline of PresentationIDRCDrivers of wastewater useIllustrations of wastewater use in citiesTheproblemwithurbanplanningWhat can be done?
  • 3. IDRCCreated by Canadian Parliament in 1970
  • 5. Research in developing countries to promote growth and development
  • 7. Partners in thisworkinclude at least 15 researchinstitutions
  • 8. WHO, IWMI, FAO, World BankDrivers of Wastewater UseWater stress and climatechangeUrbanization, populationgrowth and foodinsecurityFailure of sanitation
  • 9. Water stress isontheriseSources: Comprehensive Assessment of Water Management in Agriculture 2007; and UN Department of Economic and Social Affairs 2008
  • 10. Source: IPCC, WG2, 2008Examples of freshwater stress associatedwithclimatechange
  • 11. Increasing water scarcity combined with increased food demand and/or water use for irrigation as a result of higher temperatures are likely to lead to enhanced water reuse. Areas with low sanitation coverage might be found to be practising (as a new activity or to a greater degree) uncontrolled water reuse (reuse that is performed using polluted water or even wastewater).Source: p. 70, WG 2, IPCC 2008
  • 13. Source: ProgressonDrinkingWater and Sanitation - WHO UNICEF 2008
  • 16. Mark Redwood - PUREWastewaterPipe water
  • 17. Mark Redwood - UPEButpeople can be at riskwhenconsumingproductsirrigatedwithuntreatedorpartiallytreatedwastewater. KAMPALA EDIBLE LANDSCAPE PROJECT
  • 19. PlanningFailuresTendency to aim for high-tech, high-cost skipping steps in the sanitation ladderOperation and maintenance the inability to recover costsPolitical stasisTraining for planners has its limits there are conventions (and sometimes for good reason!)
  • 20. Whatisrequiredtochangehowwe plan and managewastewaterforreuse?
  • 21. FiveStepsThat Can Make a DifferenceRemindourselves of the ecological basis of planningReverse thewaterchainwhenwe plan and designSet anappropriatehealth-based target (2006 WHO Guidelines)Revitalize and enforce rules aboutwhatentersthesystemRecognizetheintrinsicvalue of wastewater
  • 22. (1) Key EcologicalPlanningPrinciplesFacilitate natural processMinimizecarbon and energycostWastewatermanagementthatenhancesenvironmentUnderstandthecosts and benefitsRecognizeeconomicvalue of wastewater(FAO)
  • 23. (2) Reverse WaterChainApproachMake design decisionsbased on the actual and potentialreuse of wastewater
  • 24. Effluent quality fixed by the required water characteristics in downstream irrigation
  • 25. The location of a treatment plant in relation to the agricultural field and additional fresh water resources
  • 26. Decentralization in view of cost reduction and the exclusion of toxic waste streams in the sewerage
  • 27. The lay-out of the water distribution system, incl. the construction of irrigation water storage basinsHow doesthis affect design?(Thanksto Frans Huibers at Waginingen U.)
  • 28. (3) Set appropriatehealthbasedtargetWastewater treatment may be considered to be of a low priority if the local incidence of diarrheal disease is high and other water-supply, sanitation and hygiene-promotion interventions are more cost-effective in controlling transmission. In such circumstances, it is recommended that, initially, a national standard is established for a locally appropriate level of tolerable additional burden of disease based on the local incidence of diarrheal disease for example, 105 or 104 DALY [loss] per person per year [emphasis added].
  • 30. The multiple barrier approach from Farm to ForkWastewater generationConsumerWastewater generationConsumerWastewater generationFarmer/ ProducerTraders/RetailersStreet food kitchensConsumerSafe IrrigationPracticesHygienicHandlingPracticesSafe food washing and preparation Wastewater treatmentWastewater treatmentWastewater treatmentAwareness creation to create demand for safe produceSafe produceSafe producePolicy recognition, safer farm land, tenure security, market incentives, safe-food labelling,
  • 32. In conclusionWastewater use shouldbe a part of any sensible water and sanitation planStartwith a clear idea of what use of wastewaterisforeseenEstablishthehealth-based target (usingthe WHO Guidelines)Engagetherightpeople and institutionsDesignyourmanagementsystem
  • 33. AcknowledgementsRobert Bos (WHO) Pay Drechsel (IWMI)Blanca Jimenez (UNAM)Frans Huibers (Waginingen U.)SeydouNiang (UCAD)SusanneSchierling (World Bank)Javier Sagasto (FAO)SashaKoo-Oshima (US-EPA)Duncan Mara (Leeds U.)Thor-Axel Stenstrom (SIDCC)Chris Scott (U. of Arizona)

Editor's Notes

  • #19: First, weneed to startwithstraightforwardenvironmental planning principlesthatshould not be news to any of you. Engineering is a lot about facilitatingnaturalprocesses. For instance, aeratedlagoons or ultra violet treatmentimprove water qualityusing the naturalprocessesthat break down pathogens. A second How energy intensive is a system? Carboncost has to befactored in. (3) Wherever possible, systemsthatmake use of effluent to capture its value iscritical nutrientrecycling to preventdownstreamproblems in the environment (eutrophication).(4) Costs and benefits not researchedwellenough (FAO)
  • #21: The keyisthatwastewater management bedoneusing the principle of fitforpurpose plan infrastructurebasedonthewaywaterwillbeused. Ifitisforcropsthatwillbeeatenraw, thatisonething. Ifitisgoingtobereusedfor golf coursesorothermunicpal use thatisanother. Infrastrucutureinvestments and design need to bedonewithconsideration for reuse.
  • #22: This ishighlysignificantbecausewhatthismeansisthatdifferent places should have differenthealthbasedtargets.