By Sara Jerome,
Treated wastewater could be a major asset during California's historic drought, but are people ready to drink it?
That's the question KALW reporter Audrey Dilling brought with her on a recent tour of the Silicon Valley Water Purification Center, which takes in treated wastewater and turns it into something drinkable.
The water enters the center through a local wastewater treatment plant.
"That means it has already been purified a little bit. But it’s about to embark on a journey, the likes of which no water molecule in the Bay Area has ever seen. At least not since this plant opened earlier this summer," Dilling reported.
Upon entering the center, water goes through an initial level of filtration.
“So when the water comes into the plant, it actually comes through auto strainers. These are just a strainer basket,” plant operator Kristopher Filice said in the report. “It's just to catch the big stuff – [like] birds. I mean there's all kinds of stuff that comes in from the other side.”
The water then goes through a second, finer level of filtration, moving through pores as thin as a hair. Then, reverse osmosis gets rid of molecular-level waste.
“All you're doing is making enough pressure to push a bunch of water through an expensive piece of paper. It comes out clean on one side. It's dirty on the other," Filice said.
The last step is UV light filtration to attack viruses.
“We cannot actually kill a virus. But you kill its ability to reproduce,” Filice said. “They don’t live long at all.”
But Filice says that even though the water is clean at this point, he would not drink it, because of the stigma associated with "toilet-to-tap" water.
“It's still not regulated by the Health department,” he said. “It hasn't been cleared to drink. I haven't gotten mentally over it yet. I mean, mentally, it's coming from the toilet to tap.”
The "ick factor" of drinking toilet water is a major barrier to making this method viable. Only one city in the U.S. is serving recycled wastewater to homes: Wichita Falls in Texas, another state facing down prolonged drought, KALW reported.
In July, Wichita Falls "began reusing millions of gallons of water at the River Road Waste Treatment plant that's been purified to meet government drinking standards. The water is then sent by a 12-mile pipeline to the Cypress Water Treatment Plant for additional purification," the Associated Press reported.
Daniel Nix, operations manager for the Wichita Falls Department of Public Works, told KAWL that some people now prefer the recycled wastewater.
“When we came online, within the first day or so, the feedback we were getting was that the water quality, the taste, had actually improved,” he told KALW. “And that was primarily due to the lowering of the salt concentration. The drought that we've been going through has concentrated those salts in our lake water, and so it's been steadily going up over three or so years.”
San Diego is the latest city to move toward recycling wastewater into drinking water. "The City Council voted unanimously [in November] to advance a $2.5-billion plan to recycle wastewater, the latest example of how California cities are looking for new supplies amid a severe drought," the AP reported in a separate piece.
Check out Water Online's Water Reuse Solution Center.