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Drought-Stricken California Farmers Look To Tap Urban Wastewater

The city of Modesto's wastewater treatment plant could supply millions of gallons of water to local farmers in California.
Lauren Sommer for NPR
The city of Modesto's wastewater treatment plant could supply millions of gallons of water to local farmers in California.

Many California farmers are in a tight spot this summer, because their normal water supplies have dried up with the state's extreme drought. In the state's Central Valley, that's driving some farmers to get creative: They're looking at buying water from cities — not freshwater, but water that's already gone down the drain.

The parched conditions in the valley, the state's farming hub, have been crazy. Actually, "crazy wouldn't adequately describe what we're going through here," says Anthea Hansen, who runs the Del Puerto Water District in the Central Valley. "Having zero water available — we've been in survival and crisis mode for literally 24 months now," she says.

The evidence is right across the street from her office: a 350-acre farm field. "This land would typically be farmed in probably tomatoes," she says.

Instead, the field is empty. Like a quarter of the 45,000 acres in the district, it's fallowed because there's no water. And that's Hansen's problem. As head of the Central Valley water district, it's her job to find water for this farm and 150 others.

The normal supply from federal reservoirs has been cut off. There isn't much groundwater to pump. Hansen has been buying water on the open market, but prices have gone through the roof.

What her district needs, she says, is a reliable supply — something that's there, drought or no drought. So her district turned its sights toward the wastewater treatment plant in Modesto, Calif., just a stone's throw from some of the driest agricultural areas in the state.

Will Wong gives me a tour of the plant, a couple of hours east of San Francisco. The smell isn't too bad — "kind of an earthy smell," as Wong describes it. "It's not totally offensive."

Workers install new water treatment equipment at the Modesto wastewater treatment plant, part of a $150 million upgrade.
/ Lauren Sommer for NPR
/
Lauren Sommer for NPR
Workers install new water treatment equipment at the Modesto wastewater treatment plant, part of a $150 million upgrade.

Everything that goes down the drain in the city — from 240,000 people — ends up here. Sewage may not seem like an obvious water source, but, as Wong says: "Water is water. As long as it's wet, it's water and it's valuable."

And that water will be disinfected with ultraviolet light once new equipment is installed — part of a $150 million upgrade to meet new water quality requirements. It won't be drinking-water quality, but according to state standards, it will be clean enough to use on crops.

Normally, the wastewater would be disposed of in a local river, as much as 14 million gallons a day. But Modesto had an idea: Maybe someone else would want to buy it.

"Del Puerto Water District raised their hand, as quickly as we brought the question up," Wong says.

The plan is to build a 6-mile, $100 million pipeline to carry the wastewater to a canal that goes to local farms. Called the North Valley Regional Recycled Water Program, it would be the largest water recycling project of its kind in the state.

And it won't be cheap. Farmers would pay four to five times normal water prices, but growers like Jim Jasper are more than willing to pay.

"I like to be optimistic, but without something like this, the future for my son and grandson and family — we're into this third generation — I don't know if we can keep our business going," Jasper says.

The water would meet about one-third of the water district's "hardened" demand, or the minimal supply it can get by on.

And other agricultural areas are taking notice as they face their own drought shortfalls.

"There's absolutely more potential for recycled water use in California," says Heather Cooley of the Pacific Institute, a nonprofit water think tank based in Oakland. She says California could be using two to three times more recycled water.

But there are also potential problems. For one, keeping wastewater out of a river could impact the river itself.

"You need to understand where that water would have gone," she says. "Is it providing important environmental flows? Is it providing water to a downstream community?"

That's the case for Modesto. Farmers in a nearby water district are protesting the plan. They're worried it will reduce the flow of a local river.

Recycled wastewater projects are currently used in Monterey and Sonoma counties, where urban areas are close to farm fields. But in other parts of California's Central Valley, Cooley says, location is a problem. It's expensive to move wastewater long distances, and a lot of farms are just too far from big cities and all their wastewater.

"It's not the single silver bullet solution for agriculture. Agriculture is going to have to do a lot of things to adapt to a future of less water availability," she says.

In the Del Puerto Water District, farmers see water recycling as a way to survive that future. The project still needs a slew of permits from the state, but if all goes well, the taps could open up in just three years.

Copyright 2015 KQED

Lauren Sommer covers climate change for NPR's Science Desk, from the scientists on the front lines of documenting the warming climate to the way those changes are reshaping communities and ecosystems around the world.