Southern California water district christens desalting plant that treats salty water trapped in aquifer

At a time when droughts occur more frequently and winters can be hot and bone dry, Southern California water agencies are scrambling for new water sources.

Steve Scauzillo | Daily Breeze | February 6, 2018 | Access Original

When the Water Replenishment District of Southern California located a 30-year supply trapped between the ocean and an aquifer, it was like a prospector finding gold.

About 650,000 acre-feet (one acre-foot equals 325,000 gallons or the amount a family of four uses in two years) of salty, undrinkable water lying in the Silverado Aquifer in the South Bay for decades waited to be tapped. A pilot project that began in 2002 proved new technology could turn brackish water into drinking water.

On Tuesday, 16 years later, the WRD christened an expansion of the Robert W. Goldsworthy Groundwater Desalter in Torrance, doubling its capacity from 2.5 million to 5 million gallons per day, the amount used by 15,000 households, The unique desalination plant will supply 25 percent of Torrance’s water supply, Robert Beste, the city’s director of public works, said at a ribbon-cutting ceremony attended by 150 water managers and government officials from across the region.

What was once labeled too salty for consumption can now be pumped and treated using reverse osmosis membranes that strip out the brine and other particles, leaving clean, potable water.

For a city of 147,000 that normally buys 80 percent of its water from the Metropolitan Water District, which gets it from Northern California and the Colorado River, this adds sustainability to the water supply and keeps water bills low, said Torrance City Councilman Kurt Weideman.

“We are very, very happy to have it,” Weideman said before the festivities began. “It gives the city of Torrance some independence from (buying imported water from) Metropolitan Water District.”

The city and the WRD are planning up to eight more desalter plants in the West Coast Basin, a scenario that can help not just Torrance, but 4 million people in 43 cities in south Los Angeles County become drought-proof, managers said. These include Long Beach, Carson, Pico Rivera, Lakewood, Hermosa Beach, Inglewood, Palos Verdes Estates, South Gate and Compton.

“We may not buy as much Metropolitan water,” Beste said. “Our goal is to get to the point where we are independent of imported water. It is exactly what Southern California needs.”

If cities served by the WRD can rely 100 percent on local groundwater, treated saltwater and recycled waste water, they would be free from fretting over snowfall accumulations in the Sierra Nevada.

The Sierra snow pack, a major source of Southern California water once it melts, is just 40 percent of average. Though last year’s rainy season brought a record amount of rain and snow up north, this year has been dry thus far. The U.S. Drought Monitor reported last week that 44 percent of the state is experiencing moderate drought conditions, up from 13 percent a week ago.

Ominous drought conditions, added to the driest January in the state on record, is making local water suppliers nervous. And climate change is extending droughts in the West, further curtailing natural water supplies, said Rob Kathernam, the Division 2 director on the WRD board.

“I will submit to you that we are still in a drought because climate change is changing our weather,” he said in his speech. “Over the last 50 years, we’ve seen a 30 percent drop in our rainfall in Southern California. We don’t have the same amount of snow pack in the Sierras.

“It is projects like these that will make the difference,” he concluded.

The desalter expansion cost $18 million. The WRD received $7 million from state drought funds to help build it.

The WRD has been working on new water sources for 13 years. Its massive, $110 million Groundwater Reliability Improvement Project (GRIP) plant in Pico Rivera, which will clean sewage water for injection into the groundwater for domestic use, is set to come online in July.