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. Urban Sanitation and Wastewater Reuse in Agriculture – An Urban Planning Perspective Mark Redwood Program Leader, ClimateChange and Water International Development Research Centre

2. Outline of Presentation IDRC Drivers of wastewater use Illustrations of wastewater use in cities Theproblemwithurbanplanning What can be done?

4. International Board of Governors

5. Research in developing countries to promote growth and development

6. IDRC workonwastewatergoes back to 1998

7. Partners in thisworkinclude at least 15 researchinstitutions

9. Water stress isontherise Sources: Comprehensive Assessment of Water Management in Agriculture 2007; and UN Department of Economic and Social Affairs 2008

10. Source: IPCC, WG2, 2008 Examples 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

12. Urbanization Source: UN Habitat 2008

13. Source: ProgressonDrinkingWater and Sanitation - WHO UNICEF 2008

14. Le Caire (Égypte)

15. Nouackchott (Mauritanie)

16. Mark Redwood - PURE Wastewater Pipe water

17. Mark Redwood - UPE Butpeople can be at riskwhenconsumingproductsirrigatedwithuntreatedorpartiallytreatedwastewater. KAMPALA EDIBLE LANDSCAPE PROJECT

18. Source: World Bank 2010

19. PlanningFailures Tendency to aim for high-tech, high-cost – “skipping steps in the sanitation ladder” Operation and maintenance – the inability to recover costs Political stasis Training for planners has its limits… there are conventions (and sometimes for good reason!)

20. Whatisrequiredtochange howwe plan and manage wastewaterforreuse?

21. FiveStepsThat Can Make a Difference Remindourselves of the ecological basis of planning “Reverse” thewaterchainwhenwe plan and design Set anappropriatehealth-based target (2006 WHO Guidelines) Revitalize and enforce rules aboutwhatentersthesystem Recognizetheintrinsicvalue of wastewater

22. (1) Key EcologicalPlanningPrinciples Facilitate natural process Minimizecarbon and energycost Wastewatermanagementthatenhancesenvironment Understandthecosts and benefits Recognizeeconomicvalue of wastewater(FAO)

23. (2) Reverse WaterChainApproach Make design decisionsbased on the actual and potentialreuse of wastewater

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 appropriatehealthbasedtarget 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].

29. TheStockholm Framework, 2006

30. The multiple barrier approach from “Farm to Fork” Wastewater generation Consumer Wastewater generation Consumer Wastewater generation Farmer/ Producer Traders/Retailers Street food kitchens Consumer Safe IrrigationPractices HygienicHandlingPractices Safe food washing and preparation Wastewater treatment Wastewater treatment Wastewater treatment Awareness creation to create demand for safe produce Safe produce … Safe produce … Policy recognition, safer farm land, tenure security, market incentives, safe-food labelling,…

31. WastewaterIrrigation and Health www.idrc.ca

32. In conclusion… Wastewater use shouldbe a part of any sensible water and sanitation plan Startwith a clear idea of what use of wastewaterisforeseen Establishthehealth-based target (usingthe WHO Guidelines) Engagetherightpeople and institutions Designyourmanagementsystem

33. Acknowledgements Robert 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)