A worker adjusts equipment at North America’s largest desalination plant in Carlsbad, Calif. Western states are divided about the water treatment technology. Gregory Bull/The Associated Press
Editor’s note: The story was updated Feb. 25, 2022, to correct a quote from the Berkeley Lab’s Newsha Ajami.
MONTEREY, Calif. — Gripped by drought, communities along California’s coast are exploring innovations and investments to ensure residents have access to drinking water. But desalinating seawater, one proposed solution, has provoked heated debate, as some environmentalists say the process is inefficient, expensive and unneeded.
The California Coastal Commission next month will decide whether to approve a private company’s application to build a $1.4 billion seawater desalination facility in Huntington Beach, southeast of Los Angeles. An approval would cap a 15-year permitting process to bring Southern California its second, large-scale seawater desalination facility—joining another in Carlsbad that fully opened in 2015.
That facility, just north of San Diego, provides the region with a tenth of its drinking water. Producing 50 million gallons per day, it’s the largest such facility in North America.
Many countries with limited access to freshwater, such as Israel, Saudi Arabia and the United Arab Emirates, depend on desalination. Worldwide, there are more than 21,000 desalination facilities in over 120 countries. In the American West, the technology has not yet been widely used and remains controversial. But two years of drought have inspired officials to find new ways to offset severe depletion of aquifers and reservoirs, prompting California, Arizona and other states to consider expanding desalination.
On California’s Central Coast, a company is developing a seawater desalination plant that would provide drinking water for communities from Santa Cruz south to Monterey. In the southern part of Orange County, near Doheny State Beach, the coastal community may soon have a smaller desalination facility, as well.
Desalination can provide a reliable water supply to help address shortages in the region, said Stephen Sheldon, who supports the proposed Huntington Beach facility and is president of the Orange County Water District. That board manages the county’s groundwater basin, which provides most of the area’s drinking water.
Desalination is just one piece of a broader package of solutions, Sheldon said, which includes recycling wastewater and preventing millions of gallons of clean, treated water from being dumped into the Pacific Ocean.
“The best defense to a drought is the offense of developing new water supplies,” he said. “Conservation cannot be the only solution to managing water supply in our arid region.”
Sheldon proposed a ballot initiative that would have loosened state restrictions for building new desalination plants and redirected state dollars to those projects. The initiative, however, failed to gather enough signatures for the November ballot.
The proposed facility has support from several California leaders, including Democratic Gov. Gavin Newsom and Huntington Beach Mayor Barbara Delgleize. In a column published in the Orange County Register earlier this month, Delgleize wrote that the “facility’s environmental benefits are substantial.”
She was referring to the fact that while the desalination process uses significant amounts of energy, communities save energy in the long term since the water is not transported from elsewhere in the state. She did not respond to an interview request.
But some green groups say Orange County doesn’t need the Huntington Beach desalination plant. The county has done a good job managing its water, sustaining its groundwater supply and recycling wastewater to replenish its aquifers, said Sean Bothwell, executive director of the advocacy group California Coastkeeper Alliance. The group is suing a regional water authority in state superior court to block the project.
A facility that can produce 50 million gallons a day like the proposed plant in Huntington Beach, enough to supply 8% of the area’s drinking water, would have high economic and environmental costs, he said.
It takes a lot of energy to get all the salt and impurities out of seawater. A study from the Pacific Institute, a think tank that focuses on water issues, found that while desalination has gotten more energy efficient over the past four decades, it still uses more energy per gallon of water than most other water supply and treatment options.
“It sounds like a silver bullet to solve our water crisis,” Bothwell said. “But this is going to raise water rates, it’s not good for climate change or the ocean and we have cheaper options available to meet our water supply needs.”
Bothwell does not oppose all desalination projects. But he wants communities to do a better job capturing rainwater and recycling wastewater first.
Some environmentalists also are concerned about desalination’s effect on marine life.
When seawater is treated at a desalination plant, half of what remains is a highly concentrated salty substance called brine. When brine is returned to the ocean, it can create unoxygenated dead zones that can kill fish, said Charming Evelyn, chair of the Water Committee and vice chair of the Environmental Justice Committee at Sierra Club Angeles Chapter.
“Everyone thinks that we can dip a straw into the ocean as much as we want without any consequences,” she said.
The Santa Ana Regional Water Quality Control Board, one of nine regional water authorities in the state that can approve these projects, found the company proposing to build the facility, Poseidon Water, had sufficient plans to protect marine life, such as using special screens when the plant draws water from the ocean. The company also intends to preserve the nearby 1,500-acre Bolsa Chica Wetlands. Poseidon Water officials were not available for an interview in time for publication.
There also are cost concerns for low-income residents, said Gregory Pierce, co-director of the Luskin Center for Innovation and the director of the Human Right to Water Solutions Lab at the University of California, Los Angeles. Desalination, he pointed out, has been linked to an increase in water prices in San Diego. Poseidon Water said desalination costs the average San Diego household an extra $5 a month.
In a 2019 analysis of the proposed Huntington Beach facility, Pierce and his co-authors found the new facility would “moderately to severely worsen affordability concerns” for low-income households.
“Where is the hard evidence that this is going to be cheaper than alternative supplies and is actually going to advantage low-income communities?” he asked in an interview. “I’d love to see it, but I haven’t.”
Californians instead can help close the state’s water supply gap through personal conservation, said Newsha Ajami, chief strategy and development officer for research at the Lawrence Berkeley National Laboratory’s Earth and Environmental Sciences Area, which is sponsored by the U.S. Department of Energy and managed by the University of California.
People can repurpose shower water or rainwater to supply toilets and tend to gardens and lawns, or save water by fixing leaky appliances and pipes, she said. San Francisco enacted an ordinance in October requiring new buildings that are at least 100,000 square feet to include an on-site water reuse system. The city also reuses water to irrigate parks and golf courses.
“Every drop of water you’re not wasting is a drop of water that is not polluted and doesn’t need to be treated,” she said. “We have to be mindful.”
But desalination provides an opportunity to avoid painful water reductions in the name of conservation and offers a consistent source of water if the drought persists for years, said Edward Ring, co-founder and senior fellow at the California Policy Center, a conservative think tank. It should be included in an all-of-the-above strategy for long-term water security, he added. People, he said, shouldn’t have to sacrifice their front lawns or other amenities to save water.
“There’s no theoretical limit that you could get out of the ocean. None. Zero,” Ring said. “The idea that we can’t have an abundance of water in California just doesn’t pass muster.”
It’s not just California discussing seawater desalination. In Arizona, Republican Gov. Doug Ducey last month proposed spending $1 billion to invest in new water supplies, including desalination.
Under one proposal—outlined in a 2020 binational report crafted by the U.S. government, the Mexican government and water agencies in Arizona, California and Nevada—those Western states would help pay for a new desalination facility in Mexico along the Gulf of California. In exchange for growing Mexico’s water supply, the states would be allowed to tap into Mexico’s share of the Colorado River. The project could launch in the next decade.
Arizona also is exploring desalinating brackish, slightly salty groundwater. Water experts say that is a far more cost-effective and less energy intensive way to increase the water supply. States such as Florida and Texas have made substantial investments in desalinating brackish water, which often occurs when freshwater meets seawater. It also can occur because of agricultural runoff or ground minerals.
The California Delta community of Antioch, between San Francisco and Sacramento, last year broke ground on the area’s first brackish water desalination facility, which will purify San Joaquin River water. The $110 million project was mostly funded by the state.
Seawater desalination should have a place in California, said Meagan Mauter, associate professor of civil and environmental engineering at Stanford University. In geographically isolated coastal communities that don’t have access to freshwater, desalination can be an invaluable investment, she said.
“Water desalination is great for coastal communities to meet that gap between supply and demand,” Mauter said. “But there are also lots of other sources that are cheaper and lower carbon and more flexible than seawater desalination.”
Our stories may be republished online or in print under Creative Commons license CC BY-NC-ND 4.0. We ask that you edit only for style or to shorten, provide proper attribution and link to our web site. Please see our republishing guidelines for use of photos and graphics.