If you want to take a shower or wash dishes in East Porterville, California, you’ll probably have to use a bucket. The water stopped running in most houses over a year ago. But nearby, farmers are paying to get rid of around 300 billion gallons of water a year.

The paradox is a result of a geological quirk of the area: Soil in the Central Valley is full of natural salt. That creates problems every time a farmer irrigates a field–the extra-salty runoff can harm both land and wildlife, so water districts have to deal with it. But desalination can turn the runoff from a problem into a valuable resource.

A new solar-powered desalination plant, which will likely begin construction early next year in Fresno County, will make enough water for 10,000 homes or 2,000 acres of cropland in a year.

While most desalination technology is used on coasts to turn ocean water into drinking water, WaterFX, the San Francisco-based startup behind the new plant, thinks it makes sense for California to focus on polluted inland farm water instead.

“We see it as a much lower hanging fruit to treat water that’s already a disposal problem,” says WaterFX founder Aaron Mandell. “It has a cost, it has disposal issues. So if you can recover it, it’s a much stronger value proposition than to desalinate the ocean–where not only is there no economic incentive to desalinate seawater, but it’s very difficult to permit and build a plant on the coast.”

The plants are deliberately designed at a small scale, unlike coastal plants like the massive billion-dollar facility that’s about to open in San Diego. He compares it to the way rooftop solar is spreading faster than large-scale power plants.

“Our whole philosophy is that in order to have large-scale impact, we actually have to get to small scale with desalination,” Mandell says. “Rather than building a handful of billion-dollar plants on the coasts, which take eight years to permit and a lot of money, if we can get to small scale, we can have thousands and thousands of plants all up and down the Central Valley.”