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- A new deep-sea desalination technology is undergoing testing in Southern California. Water managers hope it will offer an economical and environmentally friendly way of tapping the Pacific Ocean for fresh water.
- The CEO of the company that developed the technology calls it a moonshot to revolutionize how California — and the world — can transform seawater into drinking water.
- If the system proves viable, the company plans to build what it calls a water farm anchored to the ocean floor several miles off the coast of Malibu.
Californians could be drinking water tapped from the Pacific Ocean off Malibu several years from now — that is, if a company’s new desalination technology proves viable.
OceanWell Co. plans to anchor about two dozen 40-foot-long devices, called pods, to the seafloor several miles offshore and use them to take in saltwater and pump purified fresh water to shore in a pipeline. The company calls the concept a water farm and is testing a prototype of its pod at a reservoir in the foothills of the Santa Monica Mountains.
The pilot study, supported by Las Virgenes Municipal Water District, is being closely watched by managers of several large water agencies in Southern California. They hope that if the new technology proves economical, it could supply more water for cities and suburbs that are vulnerable to shortages during droughts, while avoiding the environmental drawbacks of large coastal desalination plants.
“It can potentially provide us Californians with a reliable water supply that doesn’t create toxic brine that impacts marine life, nor does it have intakes that suck the life out of the ocean,” said Mark Gold, director of water scarcity solutions for the Natural Resources Defense Council. “If this technology is proven to be viable, scalable and cost-effective, it would greatly enhance our climate resilience.”
During a recent demonstration at Las Virgenes Reservoir, Tim Quinn, the company’s water policy strategist, watched as the 12-foot-long cylindrical prototype was lowered underwater on a cable.
“We pull fresh water only up out of the ocean, and the salt stays down there in low concentrations, where it’s not an environmental problem,” Quinn said.
The testing at Las Virgenes Reservoir will help the company’s engineers check how the system works in filtering out plankton and discharging it back into the water. When the pod was nearly 50 feet underwater, Mark Golay, the company’s director of engineering projects, turned on the pumps and water flowed from a spigot.
The next step, expected later this year, will involve conducting trials in the ocean by lowering a pod from an anchored boat into the depths about 5 miles offshore.
“We hope to be building water farms under the ocean in 2028,” Quinn said.
Quinn previously worked for California water agencies for four decades, and he joined Menlo Park-based OceanWell two years ago believing the new technology holds promise to ease the state’s conflicts over water.
“Ocean desal has never played a prominent role in California’s water future,” he said, “and this technology allows us to look to the ocean as a place where we can get significant sources of supply with minimal, if any, environmental conflict.”
New research shows global warming has become the dominant driver of worsening drought in the western United States.
Managers of seven Southern California water agencies are holding monthly meetings on the project and studying what investments in new infrastructure — such as pipelines and pump stations — would be needed to transport the water the company plans to sell from the shore to their systems.
Leaders of Las Virgenes Municipal Water District, who are spearheading the effort, are holding an event at the reservoir Friday to showcase how the technology is being tested. The pilot study is being supported by more than $700,000 in grants from the Metropolitan Water District of Southern California and the U.S. Bureau of Reclamation.
The company still will need to secure additional permits from the federal government and the state. And it has yet to estimate how much energy the process will require, which will be a major factor in determining the cost.
But water managers and other experts agree that the concept offers several advantages over building a traditional desalination plant on the coast.
Significantly less electricity is likely to be needed to run the system’s onshore pumps because the pods will be placed at a depth of about 1,300 feet, where the undersea pressure will help drive seawater through reverse-osmosis membranes to produce fresh water.
While the intakes of coastal desalination plants typically suck in and kill plankton and fish larvae, the pods have a patented intake system that the company says returns tiny sea creatures to the surrounding water unharmed. And while a plant on the coast typically discharges ultra salty brine waste that can harm the ecosystem, the undersea pods release brine that is less concentrated and allow it to dissipate without taking such an environmental toll.
If the technology proves viable on a large scale, Gold said, it would help make Southern California less reliant on diminishing imported supplies from the Sacramento-San Joaquin River Delta and the Colorado River.
Research has shown that human-caused climate change is driving worsening droughts in the western United States. Gov. Gavin Newsom’s administration has projected that as rising temperatures diminish the snowpack and intensify droughts, the average amount of water available from the reservoirs and aqueducts of the State Water Project could shrink between 13% and 23% over the next 20 years.
Southern California’s water agencies are moving ahead with plans to build new facilities that will transform wastewater into clean drinking water, and have also been investing in projects to capture more stormwater.
In addition to the economic viability, other questions need to be answered through research, Gold said, including how well the system will hold up filtering tiny sea life, how much maintenance will be needed, and whether the pods and hoses could present any risk of entangling whales.
OceanWell’s executives and engineers say their system is designed to protect marine life and eliminate the environmental negatives of other technologies.
Robert Bergstrom, OceanWell’s chief executive, has been working on desalination projects since 1996, and previously built and operated plants in the U.S. Virgin Islands, the Bahamas and other Caribbean islands for the company Seven Seas Water, which he founded.
When Bergstrom retired, he moved to California and eventually decided to go back to work to develop technology to help solve California’s water problems.
“I had a big idea,” Bergstrom said. “I knew this was going to be just a huge lift to get this done, a moonshot.”
OceanWell, founded in 2019, now has 10 employees. Its lead investor is Charlie McGarraugh, a former partner of the investment banking company Goldman Sachs. One of its major investors is Japan-based Kubota Corp.
Building on Bergstrom’s concept, Chief Technology Officer Michael Porter and the engineering team have worked on the design. They built the first prototype in Porter’s kitchen in San Diego County, and did initial tests in a lab.
“It was inspired by the environmental community in California pointing out problems that needed to be solved,” Bergstrom said.
Desalination plants are operating in parts of California, including the nation’s largest facility, in Carlsbad, and a small-scale plant on Santa Catalina Island. But proposals for new coastal desalination plants have generated strong opposition. In 2022, the California Coastal Commission rejected a plan for a large desalination plant in Huntington Beach. Opponents argued the water wasn’t needed in the area and raised concerns about high costs and harm to the environment.
The problem of traditional shallow intakes drawing in large amounts of algae, fish larvae and plankton goes away in the deep sea, Bergstrom said, because the perpetual darkness 1,300 feet underwater supports vastly less sea life.
“We have much cleaner water to deal with,” Bergstrom said. “It’s pretty much a barren desert where we’ve chosen to locate, and as a result, we just don’t have that much stuff to filter out.”
The Las Virgenes Municipal Water District is looking to use new technology to harvest fresh water from deep in the ocean.
A specific site for the first water farm has not yet been selected, but the company plans to install it nearly 5 miles offshore, with a pipeline and a copper power cable connecting it to land.
Putting the system deep underwater will probably reduce energy costs by about 40%, Bergstrom said, because unlike a coastal plant that must pump larger quantities of seawater, it will pressurize and pump a smaller quantity of fresh water to shore.
Bergstrom and his colleagues tout their invention as a totally different approach. They say it’s not really desalinating seawater in the traditional sense, but rather harvesting fresh water from devices that function like wells in the ocean.
After their first water farm, they envision building more along the coast. Bergstrom believes they will help solve water scarcity challenges in California and beyond.
Various sites off California would be well-suited to develop water farms, from San Diego to Monterey, Bergstrom said, as would many water-scarce countries with deep offshore waters, such as Chile, Spain and North African nations.
“I believe it’ll reshape the world more than just California water,” Quinn said, “because I think the globe is looking for something that is this environmentally friendly.”
The Newsom administration is projecting that California’s State Water Project could lose up to 23% of its water delivering capacity within 20 years.
Under the company’s plans, the first water farm would initially have 20 to 25 pods, and would be expanded with additional pods to deliver about 60 million gallons of water per day, enough for about 250,000 households.
Las Virgenes and six other water agencies — including L.A. Department of Water and Power, the city of Burbank and Calleguas Municipal Water District — are working together on a study of how water could be delivered directly from the project, and at what cost, as well as how inland agencies could benefit indirectly by exchanging supplies with those on the coast.
“We’re very heavily dependent on imported water, and we need to diversify,” said David Pedersen, Las Virgenes’ general manager. “We need to develop new local water that’s drought resilient, and that can help us as we adapt to climate change.”
His district, which depends almost entirely on imported supplies from the State Water Project, serves more than 75,000 people in Agoura Hills, Calabasas, Hidden Hills, Westlake Village and surrounding areas.
During the drought from 2020 to 2022, the district was under severe water restrictions and customers reduced usage nearly 40%. Pedersen hopes the district will be able to tap the ocean for water by around 2030.
At Calleguas Municipal Water District, which delivers water for about 650,000 people in Ventura County, deputy general manager Ian Prichard said one of the big questions is how much energy the system will use.
“If the technology works and they can bring it to market, and we can afford to bring the water into our service area, then that would be great,” Prichard said. “The big test is, can they produce water at a rate that we want to pay?”
