Wastewater agriculture - only choice of water?

By Nilma Dole

Globally, using wastewater for agriculture is now seen as a solution to the water crisis. From Asia to Africa and even Latin America, this practise is becoming commonplace as many people have no other choice but to adapt to conditions of development, industrialisation and urbanisation. Hence, the water we use will also follow that pattern.

In Sri Lanka, Kurunegala is now the pilot of the 'wastewater agriculture' model. It is interesting to note that the National Water Supply and Drainage Board is working together with IWMI (International Water Management Institute) to help facilitate such a community says Priyanka Dissanayake, IWMI Environmental Specialist. "We are currently working with the Water Board to offer a proper wastewater treatment solution to the low-income communities that depend on the wastewater released from the Kurunegala Teaching Hospital for agriculture".

In lieu of this, an integrated water resources management (IWRM) plan should be implemented.

This is a problem-solving approach that meets key water challenges in ways that are economically efficient, socially equitable and environmentally sustainable, through wastewater checking practises, checking of microbial contamination, checking of wastewater parasites, methods on-farm methods and post-harvest activities, wastewater irrigation practises, checking of heavy metal presence and checking if a natural treatment policy can be adopted.

More aspects pertaining to this were highlighted at the Wastewater Agriculture and Sanitation Poverty Alleviation Workshop (WASPA) conduct recently. Expert Alexandra Clemett stated "An integrated preventive management framework for public health and environmental benefits of wastewater use should be implemented according to WHO guidelines".

The water canal in Kurunegala has two basins - the Kurunegala tank and the Wennaruwewa tank. However, as time went by, the former irrigation canal to the village turned into the present sewer from the town. This water flows from these basins via the canal and into the villages of Buela and Wanela. The farmers working on the paddy fields closer to these places have no choice but to use that polluted water.

It is vital to point out that wastewater does have side effects especially if it is filled with contaminants and pathogens that will possibly cause infection. Proper separation of solid from liquid and treatment of water should be done at the source. The use of polluted water sources without efficient safeguard measures raise health risks for farmers and consumers while actual risks depend on many factors like the living conditions of the exposed population.

Even in neighbouring India, the 'Hyderabad Declaration on Wastewater use in agriculture' offers an intricate mix of possible benefits and risks associated with wastewater use in agriculture for a balanced methodology by researchers and water experts. As clean water is increasingly becoming scarce and if proper wastewater treatment can be done to dirty water, 'wastewater agriculture' will be the only choice in the future.