A $22.5 million project in Torrance seeks to double the amount of saltwater converted to potable supplies, cut the area’s reliance on expensive imported water and boost the amount of groundwater storage to act as a greater buffer in times of drought.
“Today is a watershed event — and, yes, a pun was intended,” Torrance Mayor Pat Furey said Thursday at a ground-breaking ceremony marking the beginning of construction.
Under the project, the Water Replenishment District of Southern California — which manages two groundwater basins that provide 40 percent of the drinking water for 43 cities — will double the size of its Robert W. Goldsworthy Groundwater Desalter located at the Torrance City Yard.
Since 2001, the desalter has purified 2.5 million gallons of brackish water per day, turning a formerly undrinkable resource into one suitable for household consumption.
The saltwater comes from seawater intrusion that occurred in the 1950s and ’60s after the economy boomed and too much fresh water was extracted from underground reservoirs, including the Silverado aquifer beneath Torrance.
When finished about a year from now, the expansion project will boost that to 5 million gallons, which Torrance purchases from the district. That reduces costs to the customer because groundwater can be produced for a little more than a third of the cost of imported water.
“This will produce, when it’s completed, about a quarter of our water supply,” said Public Works Director Rob Beste, who added that the expansion is just one component of a larger project. “We are looking to (eventually) produce 60 to 80 percent of the potable water we use locally in the city of Torrance.”
The city will do so by sinking four new north Torrance wells in the next two years or so at a cost of $15 million to $20 million, depending how quickly the necessary permits are approved by regulators.
The desalter expansion will help by extracting saltwater from the huge brackish plumes contained in underground water basins to ensure the contamination doesn’t spread.
And, of course, it will ultimately boost the region’s capacity to store potable water in the underwater aquifers. These supplies will be available in case of a drought as salty water is gradually drawn down.
In fact, district officials say that a combination of projects coming online in the next three years will mean all water used by the district to replenish local groundwater supplies will come from recycled rather than imported water.
“There’s a lot of work ahead of us though,” noted Rob Katherman, the district board member whose district covers the South Bay. “There is 20 billion gallons of salty, brackish water here in our groundwater basins.”
State drought funding of about $7 million is covering a third of the cost.
Currently, 66 tube-like vessels — each containing seven fiber membranes — purify the salty water using reverse osmosis.
The project will double the number of vessels and double the amount of water the desalter can produce from what is already the largest facility of its type in Los Angeles County.
