World set to use much more wastewater: U.N.-backed study

OSLO Thu Sep 5, 2013 2:04am EDT

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OSLO (Reuters) - The world is set to use far more treated wastewater to help irrigate crops and feed a rising population as fresh water supplies dry up, a team of U.N.-backed experts said on Thursday.

A study led by Japan's Tottori University and U.N. University's Canadian-based Institute for Water, Environment and Health (UNU-INWEH) forecast "a rapid increase in the use of treated wastewater for farming and other purposes worldwide".

It did not forecast volumes, saying that many nations lack data on sewer and drain water. Of 181 nations studied, only 55 had information on wastewater generation, treatment and re-use.

Many governments and companies have so far overlooked the economic potential of vast amounts of wastewater, UNU-INWEH director, Zafar Adeel, said.

North America generates about 85 cubic km (20 cubic miles) of wastewater every year, of which about 61 cubic km is treated, roughly the amount flowing over Niagara Falls, and only four percent of that is re-used.

Wastewater also often contained nutrients such as potash, nitrogen and phosphorus which saved fertilizer costs, the study published in the journal Agricultural Water Management said.

"Properly treated, wastewater is a huge economic resource," Adeel told Reuters.

However, many developing nations cannot afford the equipment to treat wastewater even though recycling it can be cheaper in the long term than pumping water from deep aquifers, the report said, and, in Pakistan, like many other emerging economies, large areas are irrigated with mostly untreated wastewater.

Per-Arne Malmqvist, an associate of the Stockholm International Water Institute, said treatment costs were coming down. Orange County in California found it cheaper to recycle wastewater into drinking water than alternatives such as pumping it from the distant Colorado River, he said.

"It costs a lot of energy to treat the water with membranes but the technology is getting cheaper," he said.

Manzoor Qadir, an author of the study at UNU-INWEH, said costs of treatment could be kept down according to purity - for drinking water, for food crops or for crops such as biofuels.

(Editing by Louise Ireland)

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Comments (2)
JohnT63 wrote:
LOL! Those geniuses at the UN conveniently forgot all the toxic chemicals that are also in the wastewater. Which is why animal water and feed is so poor nutritionally, animals are always sick and farmers decide to fill them up with antibiotics, and the farce continues. Amazing how there doesn’t seem to be any cost associated with polluting the water (all absorb by the government at exorbitant cost to the tax payer) and at zero cost to the polluter (mainly companies. Another example of trying fix a solution when there is little understanding of the real problem.

Sep 05, 2013 10:48am EDT  --  Report as abuse
Aabman wrote:
Reuse of treated wastewater for irrigation, industry, and even for potable supply after extensive treatment is not a new practice. Water reclamation, reuse and recycling has a long and successful record, especially in the developed countries of the world. In fact, recycled water produced and used under existing regulations, far exceeds the quality of comparable water sources used for similar purposes. Unfortunately, many developing and poorer nations lack the infrastructure to collect wastewater, let alone treat and reuse it in a safe manner. That is why untreated sewage is dumped into rivers and used for irrigation and other purposes in such countries. This is a dilemma of poverty and lack of technology that normally accompanies poverty. The UN prediction of increasing volumes of recycled water in the future comes as good news, but not at all unexpected, given the rate of rise of water reuse in the last several decades. See

Sep 05, 2013 4:59pm EDT  --  Report as abuse
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