Recycling urban wastewater and using it to grow food crops can help mitigate water shortage and reduce water pollution, the UN Food and Agriculture Organization said Monday.
Use of reclaimed wastewater in agriculture has been reported in around 50 countries on what amounts to 10 percent of the world’s irrigated land, according to a report published at the start of the World Water Week by the Rome-based FAO.
But the practice is not being as widely implemented as it should.
Now, only a few countries like Spain and Mexico, for example, use a high proportion of reclaimed water in irrigation.
“The case studies in this report show that safely harnessing wastewater for food production can offer a way to mitigate competition between cities and agriculture for water in regions of growing water scarcity,” said Pasquale Steduto, deputy director of FAO’s Land and Water Division.
“In the right settings, it can also help to deal with urban wastewater effluent and downstream pollution,” he said.
Farmers would also be able to avoid some of the costs of pumping groundwater, while the presence of nutrients in the wastewater would reduce their fertilizer expenses.
“Properly treated and safely recycled water can potentially offer a ‘triple dividend’ to urban users, farmers and the environment,” said Steduto.
“While reusing wastewater in agriculture isn’t the only way to tackle problems of scarcity and pollution, it is in many situations an extremely cost-effective solution, as the growing number of reuse schemes that we look at in this report testify,” the FAO expert said.
The feasibility of reusing water in agriculture depends on local circumstances and conditions, which will affect the balance of costs and benefits, FAO’s report notes.
The report also stresses that raw or untreated wastewater is inappropriate for use in irrigation — adequate treatment and recycling is always required. [PNA]
