Recycling sewage water – in combination with desalination plants –  has enabled Israel to avoid dependence on rain. But with about half of the water used on Israel’s farms coming from treated sewage water, researchers are paying close attention to what’s in it. Is it clean enough, or could pharmaceutical residues, for example, have long-term consequences?

Emily Harris (@emilygharris) wrote this piece for NPR’s Weekend Edition.

The Israeli government says “it’s safe to use treated sewage water to irrigate tree fruit, but not all crops.” A red pipe indicates that the water is not potable, but rather, is destined for agricultural irrigation. The water comes from a variety of sources: residential use such as toilets and sinks, and even from chip manufacturing plants. The price of this water is cheaper, too.

Some things remain unknown about the use of recycled sewage, because even the “highest quality recycled sewage has trace pollutant elements that are not regulated.”

At Hebrew University’s Smith Faculty of Agriculture, [Benny] Chefetz studies the effect that elements from pharmaceuticals and personal care products in treated sewage have on soil and food when used for irrigation.

In a small lab, he is dosing cucumbers with anti-epilepsy medications that break down very slowly in the soil. Chefetz says how trace chemicals in water move into food depends on the chemical, the crop and the soil quality.

There is a lot to learn, he says.

“We have no idea what [are] the consequences,” he says, if a child is continuously exposed to even tiny amounts of medications by eating carrots or cucumbers.

He says it’s important to figure out what’s safe, because using treated sewage water is important.

Related Links:

The drought fighter

UC researcher uses technology to tackle global food security and climate change