Title: Reducing the Risks of Wastewater Irrigation: Strategies and Incentives
Event type: Seminar
Date: 2010-09-05
Time: 14:00 - 17:30
Convenor: International Water Management Institute (IWMI), International Development Research Centre (IRDC), World Health Organization (WHO), Food and Agriculture Organization of the United Nations (FAO) and World Bank (tbc)
Room: K16/17

Event Description
The seminar will support the new WHO-FAO-UNEP guidelines on the safe use of wastewater, greywater and excreta in agriculture by looking at related financial and economic aspects. Key questions are how to support the implementation of recommended health risk-reduction strategies in situations of existing and non-existing risk awareness? How to value the costs and benefits of wastewater irrigation? And how best to reduce the cost and enhance the benefits of protecting the health of farmers and consumers where wastewater is used?

We will examine the cost-effectiveness of alternative risk mitigation measures by drawing on pilot studies on the implementation of the new guidelines and discuss analytical approaches, policy interventions and farm-level initiatives that reduce the risk from pathogens at several stages along the exposure pathway. This includes conventional and unconventional wastewater treatment, and food preparation.

We will focus primarily on irrigation with untreated wastewater in developing countries, where water pollution is its main driver, but also look at other positions on the sanitation ladder, giving the increasing need for wastewater use in situations of water scarcity.

The event will close with the announcement/presentation of four new publications on wastewater irrigation by the World Bank, WHO, FAO and IWMI-IDRC.


Chair: Mr. Mark Redwood, IDRC, Canada
Rapporteur: Mr. Robert Bos, WHO, Switzerland


Welcome and Introduction: The 2006 WHO-FAO-UNEP Guidelines and the multiple barrier approach: Implementation challenges. Mr. Pay Drechsel, IWMI, Sri Lanka


An economic framework for wastewater irrigation: Cost-benefit analysis and financial considerations. Mr. Javier Mateo-Sagasta Dávila, FAO, Italy


Financial incentives and considerations to enhance the adoption of safer irrigation practices. Mr. Marwan Owaygen, IDRC, Canada


Non-financial incentives and cost-effectiveness of risk reduction. Mr. Pay Drechsel, IWMI, Sri Lanka


Planning for wastewater use in agriculture in the face of growing water scarcity. Ms. Susanne Scheierling, Water Anchor, World Bank


Coffee Break


Panel taking further questions from audience

  • Chair: Mr. Dennis Wichelns, IWMI, Sri Lanka
  • Rapporteur: Mr. Mark Redwood, IDRC, Canada
  • Panel: Mr. Robert Bos, WHO, Switzerland, Ms. Julia Bucknall, World Bank, USA, Mr. Javier Mateo-Sagasta Dávila, FAO, Italy, Mr. Marwan Owaygen, IDRC, Canada, Mr. Pay Drechsel, IWMI, Sri Lanka

Summary (comments by Moderators and Rapporteurs)


Launch/announcements of new publications by co-conveners

  • World Bank report on "Improving Wastewater Use in Agriculture: An Emerging Priority"
  • WHO-FAO-IDRC-IWMI Info Kit Vol. 2 on the Third Edition of the Wastewater Use Guidelines
  • FAO Water Report 35: "The Wealth of Waste: The economics of wastewater use in agriculture"
  • IWMI-IDRC-Earthscan book "Wastewater Irrigation & Health: Assessing and mitigating risk in low-income countries"

Close of Seminar

Event Summary and Conclusions
The seminar analyzed social, economic and financial aspects of the WHO-FAO-UNEP Guidelines for the Safe Use of Wastewater, Excreta and Greywater in Agriculture and Aquaculture (2006), with a focus on the acceptance of wastewater as a valuable resource and adoption of safe irrigation practices.

To show the value of wastewater under water scarcity, a case study in Spain quantified the overall net profit of a water exchange scheme, with farmers being compensated for using reclaimed water while ‘releasing’ high value freshwater for urban use. This approach can be potentially applied in many middle-income countries in water-scarce areas. The example was taken from the new FAO Water Report 35 www.fao.org/docrep/012/i1629e/i1629e.pdf which gives a methodology for the comprehensive economic appraisal of wastewater reuse projects. 

Efforts to achieve health-based targets should build on wastewater treatment as well as non-treatment options, using a multi-phased approach which considers the limitations and opportunities in individual countries. Where treatment is not feasible, crop restrictions could work if regulations can be enforced. Options for different financial incentives were discussed for scenarios where regulations are weak, in order to support farmers and traders to adopt alternative safety measures and counter the attraction of maximizing benefits at the expense of safety. A positive market response would be the best incentive but requires risk awareness among consumers. Alternative financial incentives include access to credit or input subsidies.

The IWMI case of Ghana (www.idrc.ca/openebooks/475-8/) showed that up to 90% of the DALYs from the use of untreated wastewater could be averted through low-cost interventions on- and off-farm. Next to financial incentives, education and social incentives (such as improved tenure security) could enhance the adoption of safety measures. A high adoption rate is essential for maintaining the generally positive cost-effectiveness of on- and off-farm measures that reduce health risk.

In the face of growing water scarcity, planning for wastewater use in agriculture is of growing importance across the spectrum from lower- to higher-income countries. A new World Bank Policy Research Working Paper (WPS 5412) http://go.worldbank.org/UC28EAWNI0 differentiates between four country income levels to create a typology for analyzing current issues, trends, and priorities.

A guidance note on how to apply the WHO guidelines at different levels of the sanitation ladder is provided in the second edition of the WHO information kit on their 2006 guidelines www.who.int/water_sanitation_health/wastewater/usinghumanwaste/en/index.html which was launched together with the other mentioned publications.

While most of the discussion focused on low-income countries with limited industrial development, research gaps were acknowledged in view of emerging economies where chemical contaminants can not easily be addressed via non-treatment options.

Key lessons were

  • Widespread water pollution leads to wastewater irrigation across the developing world.
  • Success of wastewater treatment options depends on locally appropriate technologies and institutional incentives for the required maintenance. Success of non-treatment options depends critically on financial and non-financial incentives for human behavioral change.
  • Especially in regions where water scarcity is rapidly increasing, wastewater use in agriculture needs to become an important part of the broader IWRM strategies.


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Wastewater Irrigation and Health
Water, Health and Sanitation