Using wastewater on farms sparks environmental and health worries
Using wastewater from toilets and showers to irrigate fields in parched Southern Europe is at the heart of the EUs circular economy plans.
Countries such as Spain, Italy and Greece are facing growing water shortages, in part due to climate change, so theyre supplementing traditional fresh water with treated wastewater. A new European Commission proposal from May would set minimum requirements for water reuse, but countries would be able to also set their own higher standards.
Until the proposal becomes official, and it may not, governments can set their own laws regulating how farmers can use treated liquid waste.
But this circular solution may not be so perfect: There are worries that using wastewater for irrigation will harm already depleted rivers. And such water may host pollutants ranging from nitrates to microplastics and pharmaceuticals that are difficult and expensive to clean.
Brussels insists that its proposal will make using wastewater “safe and cost-effective,” said Enrico Brivio, the Commissions spokesman on environmental issues.
Circle of life
The water used in toilets, showers, for dishes and laundry flows into treatment plants along with solid waste. The liquid is divided from solid matter and semi-solid sludge, treated to remove pollutants and nutrients such as phosphates and nitrates, and then disinfected to make it safe for reuse after which it is pumped to sprinkler systems on farms.
Instead of flowing back into rivers, treated water ends up on fields.
“You can have different quality of water dependent on the exposure from the water to products grown by farmers,” said Bertrand Vallet, a policy officer on water services for EurEau, the water utilities lobby. “For example, apples grown using drip irrigation, or drops in soil, dont need the same level of quality as strawberries eaten raw by consumers.”
Scientists say there is evidence that an increasing demand for treated urban wastewater is reducing the river levels in Europes agricultural powerhouses such as Murcia in southern Spain.
“Murcia is one of the regions with the highest proportion of water reuse at close to 90 percent. It is reducing the circulating water flows in the Segura River,” said Julia Martínez, executive director of the Foundation for a New Water Culture, a nonprofit run by scientists and academics pushing for more sustainable water management. “We need to ensure the Segura River is receiving an equivalent amount of the water that isnt coming back from the wastewater treatment plants.”
Using wastewater may affect rivers, but it helps keep farmers from pumping underground aquifers dry. Thats why reused water is cheap.
“If the water is expensive, the farmers arent going to use it. Theyll take surface water or groundwater that is then not available for drinking water because they need to irrigate their crops,” Vallet said.
Commission spokesman Brivio said using wastewater from urban treatment plants helps the environment because it “extends the water life cycle, thereby helping to preserve water resources.”
NGOs say recycling water this way isnt a long-term solution to the lack of rain. Rather than pumping more water, people should learn to use less.
“We arent against water reuse but I think it is being framed in the wrong way,” said David Sánchez, a campaign officer with Food & Water Europe. “It is another way to increase the water offer that is going to create more demand and not going to solve the problem it is supposed to solve, which is water scarcity.”
Something in the water
Environmentalists also worry that using wastewater is risky because it could contain drugs and chemicals. According to the Commissions draft communication on pharmaceuticals in the environment, obtained by POLITICO, there are more than 3,000 drugs for sale in the EU, and some of them end up in wastewater after being used by people.
The document says synthetic estrogen, the main ingredient in contraceptive pills, in water has feminized male fish, making it harder for them to reproduce. And studies have found the painkiller diclofenac in fish and sea otters in Europe.
There has been no clear link between drug residues in the environment and direct impacts on humans. However, since it is more expensive to treat polluted water, it remains unclear who should pay to clean up medicine residues from waste water.
Brivio said that any food irrigated with reused water is safe because the Commission ensured that its proposal met rigorous health and environmental standards. EU countries such as Spain and Italy already have their own national standards to protect human health, such as grading the quality of the water and determining what kind of fruit and vegetables it can be used for. The EU wants to harmonize those rules.
He said all countries reusing water have to meet “the same minimum parameters, so as to secure a level of water quality which avoids any health or environmental risks.”
The proposed regulation is now making its way through the European Parliament and Council of the EU. MEP Jan Huitema, shadow rapporteur for the ALDE group on the file, said water reuse could be a viable solution for parched areas.
“We have to guarantee safety for the environment and humans, but water scarcity is becoming more and more of a problem so we need to investigate this as a solution,” Huitema said.
Back in Spain, Julia Martínez from the Foundation for a New Water Culture says the goal of the proposal shouldnt be to only to increase water supplies but it should also rethink how water is used and managed.
“As long as you are increasing the amount of water used, in the end, water stress is generally increased,” she said.
This article is part of a series on the circular economy, Getting Wasted.