Noticia(s) 7 de 16

 

The session’s objectives were to review the state of safe use of wastewater in agriculture and aquaculture, to discuss emerging issues in this field and, particularly, to assess the impact of the WHO guidelines on the ground and how to strengthen this impact. The session was structured around five presentations (three conceptual, two case studies) followed by a Panel discussion. It was attended by a “rolling” audience that averaged 35 people.

 

The session highlighted that irrigation using wastewater will continue to grow and that its safe use will be an ever-increasing challenge in the future as its two key drivers (water pollution leading to unplanned use, and water scarcity leading to planned use) are both on the increase. Currently, the ratio between unplanned use of untreated wastewater to the mostly planned use of treated wastewater is 10:1 with the majority of highly polluted water usage in China.

 

The 2006 third edition of the WHO Guidelines for the safe use of wastewater, excreta and greywater for agriculture and aquaculture acknowledges this development by shifting its focus away from water quality standards that are unattainable in most low-income countries(as in the second edition) to health-based standards to be achieved through an incremental process of risk assessment and management along the chain of events, from where wastewater is generated to consumption of produce. This gives countries at the bottom of the sanitation ladder many more options for addressing health risks than before; it also recognizes wastewater as an economic good, both as a water resource and as a source of nutrients.

This shift has resulted a debate on the feasibility of having countries perform the necessary risk assessment and management practices on a routine basis. This has affected the adoption rate of the guidelines; it is perceived to be lower than expected. At the same time, it is recognized that current regulatory frameworks at the national level are based on policies derived from the second edition and that it will take time to adapt these.  Nevertheless, there is a sense that the complexity of the approach in the new edition comes across as increasingly academic and data demanding, and requires an in-depth understanding of new tools and approaches.

 

The focus on health-based targets for the consumption of irrigated food implies a reduced attention to environmental water quality needs or multi-purpose water use (including irrigation) except for those countries where wastewater treatment is gaining momentum and coverage. The challenge is how to integrate environmental aspects in the Guidelines where treatment is not catching up with wastewater generation.

 

To tackle the two issues (the need for capacity building and the need to connect the health issues with broader environmental and use issues, it was suggested that the concept of ‘Wastewater or Sanitation Safety Plans’ could be a solution. These would be similar to the Water Safety Plans that have been gaining rapidly in popularity as an instrument to implement the WHO Drinking-water Quality Guidelines.

 

There was a consensus that more technical notes in support of the 2006 edition of the Guidelines are needed to make them easy to understand for countries at different positions on the sanitation ladder. The information kit produced after the Guidelines’ publication could be published in updated versions on a regular basis.  More emphasis could also be given to economic aspects and guidance on how to support a) a paradigm shift from ‘treatment for disposal’ to ‘treatment for re-use’, and b) the facilitation of the adoption of safer irrigation practices and other post-treatment options where there are no market incentives. Here the Guidelines could learn from the social marketing work in the WASH sector.

 

In summary, following are the main points that emerged from the discussions.

 

(1)   the need for regular updates and revisions, to be communicated either over the web or through the production of new editions of the Information Kit.

(2)   The need for a fifth volume of the guidelines. Focusing on standardizing or harmonizing analytical methods – a new initiative between Brazil, Mexico and South Africa was brought up by Blanca Jimenez – and this will be taken up by WHO.

(3)   Rather than wastewater safety plans, the group suggested to consider sanitation safety plans, with a broad interpretation of sanitation so that environmental issues could be taken on board adequately.

(4)   There was a need to develop targeted training on some of the complex technical methods proposed in the guidelines such as QMRA

(5)   Economics was a key driver and more research is needed to clarify the economic issues related to wastewater use and the consumption of wastewater produced vegetables and fish.

 

Robert Bos, WHO

Pay Drechsel, IWMI

Sarantuyaa Zandaryaa, UNESCO

Noticia(s) 7 de 16