News Feature | February 8, 2017

Desalination A Winner In California Drought

Sara Jerome

By Sara Jerome,

A major consequence of the California drought is that the state may become more reliant on brackish-water desalination.

As the drought appears to wind down in certain parts of the state, experts are analyzing the consequences of the dramatic weather. The Pacific Institute, a nonprofit research institute, recently published an 80-page report that the organization called “the first statewide analysis of the impacts of the drought on California’s most vulnerable communities.”

One major offshoot of the drought is that California may take steps to become more reliant on brackish-water desalination, according to the San Jose Mercury News, which cited Pacific Institute researchers. The newspaper said current research is “spurring hopes that the desalination of brackish water could quickly become a vital tap in the state.”

Heather Cooley, director of the water program at the Pacific Institute, spoke to the Mercury News.

“There are places in California where there may be groundwater available, but it may not be fresh,” Cooley said. “Those are places where it’s possible to use brackish desalination at a much lower cost and with fewer social and environmental impacts than ocean desalination.”

Desalination facilities are operating in locations across California.

“The state now has five ocean desalination plants — the largest one opened last year in Carlsbad in San Diego County. And a previously mothballed ocean desalination plant is set to reopen in Santa Barbara in March. In contrast, California’s brackish desalination plants are mostly located inland. There are currently two dozen such facilities in the state producing a total of 80,000 acre-feet of water per year. That’s a year’s worth of water for 400,000 people,” The Mercury News reported.

A major benefit of brackish-water desalination is the salt concentration of the supply is lower than seawater. Brackish water is about 3.5 times less salty than seawater, which halves the price of desalting it, according to The Mercury News. Salt concentrations run from 1,000 to 10,000 milligrams per liter, the report said.

Additional brackish water desalination projects are up for discussion in California.

“A coalition of Bay Area water agencies is considering a [large] brackish desalination plant in Pittsburg, with the potential to desalt water from the Delta and deliver 23,000 acre-feet of water per year,” The Mercury News reported.

A proposal to invest in desalination in Pittsburg was previously scrapped in 2014 “when the region’s four largest water districts decided they could obtain water more cheaply through expanding water recycling, conservation programs and other means,” The Mercury News previously reported.

Compared to seawater processes, brackish-water desalination is less controversial among environmentalists because it does not pose a threat to marine life, The Mercury News reported. The process is also more energy-efficient.

“The more saline the water, the more intensive the treatment and the more energy required, which makes the cost higher,” Cooley noted, per The Mercury News.

For similar stories visit Water Online’s Water Reuse Solutions Center.