Urban Sanitation, Wastewater And Climate Change


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Wastewater is a response to a lack of available good quality water. This is a presentation on the topic given to the IWA World Water Congress in Montreal, Sept. 21, 2010.

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  • 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)
  • 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.
  • This ishighlysignificantbecausewhatthismeansisthatdifferent places should have differenthealthbasedtargets.
  • Urban Sanitation, Wastewater And Climate Change

    1. 1. Urban Sanitation and Wastewater Reuse in Agriculture – An Urban Planning Perspective <br />Mark Redwood<br />Program Leader, ClimateChange and Water<br />International Development Research Centre<br />
    2. 2. Outline of Presentation<br />IDRC<br />Drivers of wastewater use<br />Illustrations of wastewater use in cities<br />Theproblemwithurbanplanning<br />What can be done? <br />
    3. 3. IDRC<br /><ul><li>Created by Canadian Parliament in 1970
    4. 4. International Board of Governors
    5. 5. Research in developing countries to promote growth and development
    6. 6. IDRC workonwastewatergoes back to 1998
    7. 7. Partners in thisworkinclude at least 15 researchinstitutions
    8. 8. WHO, IWMI, FAO, World Bank</li></li></ul><li>Drivers of Wastewater Use<br />Water stress and climatechange<br />Urbanization, populationgrowth and foodinsecurity<br />Failure of sanitation<br />
    9. 9. Water stress isontherise<br />Sources: Comprehensive Assessment of Water Management in Agriculture 2007; and UN Department of Economic and Social Affairs 2008<br />
    10. 10. Source: IPCC, WG2, 2008<br />Examples of freshwater stress associatedwithclimatechange<br />
    11. 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).”<br />Source: p. 70, WG 2, IPCC 2008<br />
    12. 12. Urbanization<br />Source: UN Habitat 2008<br />
    13. 13. Source: ProgressonDrinkingWater and Sanitation - WHO UNICEF 2008<br />
    14. 14. Le Caire (Égypte)<br />
    15. 15. Nouackchott (Mauritanie)<br />
    16. 16. Mark Redwood - PURE<br />Wastewater<br />Pipe water<br />
    17. 17. Mark Redwood - UPE<br />Butpeople can be at riskwhenconsumingproductsirrigatedwithuntreatedorpartiallytreatedwastewater. <br /> KAMPALA EDIBLE LANDSCAPE PROJECT<br />
    18. 18. Source: World Bank 2010<br />
    19. 19. PlanningFailures<br />Tendency to aim for high-tech, high-cost – “skipping steps in the sanitation ladder”<br />Operation and maintenance – the inability to recover costs<br />Political stasis<br />Training for planners has its limits… there are conventions (and sometimes for good reason!)<br />
    20. 20. Whatisrequiredtochange<br />howwe plan and manage<br />wastewaterforreuse?<br />
    21. 21. FiveStepsThat Can Make a Difference<br />Remindourselves of the ecological basis of planning<br />“Reverse” thewaterchainwhenwe plan and design<br />Set anappropriatehealth-based target (2006 WHO Guidelines)<br />Revitalize and enforce rules aboutwhatentersthesystem<br />Recognizetheintrinsicvalue of wastewater<br />
    22. 22. (1) Key EcologicalPlanningPrinciples<br />Facilitate natural process<br />Minimizecarbon and energycost<br />Wastewatermanagementthatenhancesenvironment<br />Understandthecosts and benefits<br />Recognizeeconomicvalue of wastewater(FAO)<br />
    23. 23. (2) Reverse WaterChainApproach<br />Make design decisionsbased on the actual and potentialreuse of wastewater<br />
    24. 24. <ul><li>Effluent quality fixed by the required water characteristics in downstream irrigation
    25. 25. The location of a treatment plant in relation to the agricultural field and additional fresh water resources
    26. 26. Decentralization in view of cost reduction and the exclusion of toxic waste streams in the sewerage
    27. 27. The lay-out of the water distribution system, incl. the construction of irrigation water storage basins</li></ul>How doesthis affect design?<br />(Thanksto Frans Huibers at Waginingen U.)<br />
    28. 28. (3) Set appropriatehealthbasedtarget<br />Wastewater 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, ≤10−5 or ≤10−4 DALY [loss] per person per year [emphasis added].<br />
    29. 29. TheStockholm Framework, 2006<br />
    30. 30. The multiple barrier approach from “Farm to Fork”<br />Wastewater generation<br />Consumer<br />Wastewater generation<br />Consumer<br />Wastewater generation<br />Farmer/ Producer<br />Traders/Retailers<br />Street food kitchens<br />Consumer<br />Safe IrrigationPractices<br />HygienicHandlingPractices<br />Safe food washing and preparation <br />Wastewater treatment<br />Wastewater treatment<br />Wastewater treatment<br />Awareness creation to create demand for safe produce<br />Safe produce<br />…<br />Safe produce<br />…<br />Policy recognition, safer farm land, tenure security, market incentives, safe-food labelling,…<br />
    31. 31. WastewaterIrrigation and Health<br />www.idrc.ca<br />
    32. 32. In conclusion…<br />Wastewater use shouldbe a part of any sensible water and sanitation plan<br />Startwith a clear idea of what use of wastewaterisforeseen<br />Establishthehealth-based target (usingthe WHO Guidelines)<br />Engagetherightpeople and institutions<br />Designyourmanagementsystem<br />
    33. 33. Acknowledgements<br />Robert Bos (WHO) <br />Pay Drechsel (IWMI)<br />Blanca Jimenez (UNAM)<br />Frans Huibers (Waginingen U.)<br />SeydouNiang (UCAD)<br />SusanneSchierling (World Bank)<br />Javier Sagasto (FAO)<br />SashaKoo-Oshima (US-EPA)<br />Duncan Mara (Leeds U.)<br />Thor-Axel Stenstrom (SIDCC)<br />Chris Scott (U. of Arizona)<br />