A wastewater recycling program could be a model for regions where water is scarce

The Orange County Water District's wastewater recycling program uses ponds, manmade waterfalls and technology to keep wells from running dry -- a model for other regions facing water scarcity.

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Orange County in Southern California is doing something unusual to help with the scarcity of fresh water there. They're putting clean recycled water into the ground. See; rivers run low in the summer, and there's not a lot of rain. And as water sources get less predictable across the country because of climate change, the OC strategy is inspiring other water districts to follow suit. NPR's Pien Huang went to see how it's done.

PIEN HUANG, BYLINE: If you drive far enough down a dirt road in Anaheim, you'll come to this, a manmade waterfall tucked behind a brewery and some factories.

BEN SMITH: Right now we're looking at a waterfall. It's about 40 million gallons a day, and it's nice. We catch a little mist off the waterfall. It's nice to be cool.

HUANG: Ben Smith directs recharge operations at the Orange County Water District. It built this waterfall and the big manmade lake below it.

SMITH: So we're at the La Palma basin. This is our dedicated recharge basin for the groundwater replenishment system, the recycled sewage water, highly purified.

HUANG: The water is so clear, it looks tropical. Smith says it's the visible part of a large-scale project to create a steady source of drinking water for the region.

SMITH: It percolates. It goes down through the soil. It will spend several months traveling slowly through the aquifer until it reaches a production well, where a city or a water agency will pump it out of the ground and serve it to the homes and businesses.

HUANG: The lake's headwater is a water purification plant 20 miles to the south. It's at the Orange County Water District headquarters, where Jason Dadakis is an executive director.

JASON DADAKIS: In terms of production capacity, this is the largest water recycling facility of its kind.

HUANG: Dadakis took me on a factory tour. The plant starts with treated wastewater, which would otherwise get dumped in the ocean. It filters it, disinfects it and ultimately reclaims about 85% of it as clean, drinkable water.

DADAKIS: We do offer all of our tour guests the opportunity to taste the water at the end of the tour.

HUANG: Cheers, guys.

UNIDENTIFIED PERSON: Cheers.

DADAKIS: Cheers.

HUANG: It tastes like water. It's lukewarm. It doesn't taste like a lot.

That cleaned, recycled wastewater gets piped to the lake in Anaheim and a few others like it. It fills the water needs for a million residents a year. This project started in Orange County more than 15 years ago, and Michael Kiparsky at the Wheeler Water Institute at Berkeley Law says they were real pioneers.

MICHAEL KIPARSKY: I would say that the OC is the OG of this kind of recharge project.

HUANG: One of the first and the largest and the most well-known among water people.

KIPARSKY: It takes advantage of a problem that we've made. In many cases, we have mismanaged groundwater resources. And the result of that is that often you have aquifers that have space in them.

HUANG: When too much groundwater is lost, it can leave gaps underground that collapse and cause sinkholes. Or in areas along the coast, they can fill with seawater and make the groundwater undrinkable. So reclaimed water seems like a win. Why doesn't everyone do it? I asked Sharon Megdal, director of the Water Resources Research Center at the University of Arizona.

SHARON MEGDAL: This is not a simple undertaking because not only are there the geology and kind of physical aspects of the water table, the aquifers and the like, but there are also water quality implications.

HUANG: Megdal says it's a huge natural experiment that depends on the soil and bedrock of a specific place. It can change the water chemistry underground and risk pollution from natural arsenic or leach fertilizers and industrial chemicals. And it's also quite expensive. Orange County has spent more than $900 million over 20 years on this project. But Megdal says as climate change causes water sources to shift, it's a type of project a lot more places are considering. Pien Huang, NPR News.

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