A water district greatest identified for supplying the celebrity-studded enclaves of Calabasas and Hidden Hills might quickly turn into well-known for a very completely different cause.
The Las Virgenes Municipal Water District lately partnered with California-based OceanWell to review the feasibility of harvesting consuming water from desalination pods positioned on the ocean flooring, a number of miles off the coast of California.
The pilot undertaking, which can start in Las Virgenes’ reservoir close to Westlake Village, hopes to ascertain the nation’s first-ever “blue water farm.”
The firm says that by combining desalination with off-shore power expertise, it will probably resolve most of the challenges related to conventional, land-based desalination, together with excessive power prices and salty byproducts that threaten marine life. The course of might produce as a lot as 10 million gallons of contemporary water per day — a vital achieve for an inland district virtually solely reliant on imported provides.
“It gives us a sense of long-term water reliability, but it also gives us the idea that we can really start weathering the storms, if you will, when it comes to climate change impacts, and specifically droughts,” mentioned Mike McNutt, a spokesman for Las Virgenes. “This can be a game changer for Las Virgenes, but it could be a game changer for any water agency anywhere.”
Local environmental teams mentioned the idea appears promising, however not with out downsides.
“Our policy is that ocean desalination should always be the last resort,” mentioned Charming Evelyn, chair of the Sierra Club’s water committee in Southern California. “Water is not an infinite resource. It is extremely finite, and the ocean is not something we just get to dip a large straw in and pull whatever we want out, because even the ocean has to maintain a balance.”
The conventional desalination course of pumps seawater from coastal areas into services on land, the place the water is pushed by way of tremendous membranes and filters to take away salt and different supplies. The course of is power intensive — usually fueled by greenhouse-gas-emitting fossil fuels — and produces a thick, briny sludge on the back-end that’s sometimes launched again into the ocean. Studies have proven the concentrated brine might be dangerous to marine life.
But OceanWell says its expertise can use as much as 40% much less power by harvesting the water in pods positioned at depths of about 1,400 toes, the place naturally immense water stress may also help energy the filtration course of.
“Basically the weight of the ocean helps drive the reverse-osmosis process,” mentioned Kalyn Simon, OceanWell’s director of engagement. “By taking the [reverse-osmosis] process to a place in nature where that pressure naturally exists, we don’t have to create an artificial pressure gauge on land, as we traditionally do in desalination.”
The depth is called the aphotic zone — a a part of the ocean the place there may be little-to-no daylight, and the place there may be much less marine life than layers above, she mentioned. Such depths are sometimes discovered between three and 7 miles off the coast of California, relying on location, which suggests the undertaking would run by way of state and federal waters.
The course of additionally produces no brine, Simon mentioned.
Land-based services attempt to squeeze out as a lot freshwater as doable to assist steadiness excessive power prices, with typical targets of fifty% freshwater and 50% brine from each gallon processed. But as a result of OceanWell makes use of “free” stress from the ocean, it will probably function at a decrease restoration fee of 10% to fifteen%, producing a a lot much less salty byproduct that may be dissolved again into ambient situations inside seconds, she mentioned.
A “farm” would include a number of desalination pods — 40-foot vast cylindrical cartridges that comprise consumption pumps — that draw seawater by way of a semi-permeable filter membrane. The filtered freshwater can be returned to shore by way of a pipeline, whereas the seawater outfall can be discharged from the pods into the ocean by way of a tall column.
“The solution never has time to settle on the sea floor — it goes into the current,” Simon mentioned. “There are no known effects on the ocean at this low of a concentration, and we will be continuing to do studies and environmental tests to continue to prove that.”
The expertise is intriguing, mentioned Mark Donovan, chair of the CalDesal advocacy group, who can be the North American water therapy and desalination lead with GHD, an engineering and consulting agency.
“The concept of putting it down at the bottom of the sea floor, deep enough where that hydrostatic pressure can drive the reverse-osmosis process — there’s certainly merit to that,” Donovan mentioned. And by working at a very low restoration fee, “it’s true they’re not generating as salty of brine as the traditional, land-based system does.”
Desalination was among the many applied sciences outlined in Gov. Gavin’s Newsom’s water provide technique, launched in 2022 amid the state’s driest three years on document. California is anticipated to see a 10% lower in its water provide by 2040 due to greater temperatures and decreased runoff, the governor’s plan mentioned.
Donovan mentioned he sees desalination enjoying a pivotal function within the state’s response to shrinking water provides. He was glad to see OceanWell gaining traction with a native water district.
“I think it’s very good for the industry and for California as a whole,” he mentioned.
The Las Virgenes district, which provides about 75,000 individuals, is nearly solely reliant on imported water from the State Water Project, a huge community of reservoirs, canals and pipelines that feeds dozens of businesses throughout the state. But the district faces routine challenges throughout instances of drought, particularly when state officers are compelled to slash their allocations.
In addition to the OceanWell pilot, Las Virgenes can be transferring ahead with plans for the Pure Water Project, a wastewater purification facility that may have the capability to deal with as much as 6 million gallons per day and increase the area’s provide.
The mixture might reduce the district’s reliance on imported water in half, in accordance with McNutt, the Las Virgenes spokesman.
“We’re now going to be one of the first to push forward this new technology that could have major impacts on long-term water reliability, with minimal environmental impacts, to the entire state of California,” he mentioned. “Beyond that, we promised our communities after the last drought that we would look into desalination as a possible viable option to provide water to the service area so we wouldn’t go through what we did before.”
Funding for the pilot undertaking will come from OceanWell, with Las Virgenes offering in-kind providers, together with the usage of its 120-foot-deep reservoir for testing the expertise.
Las Virgenes prides itself on its forward-thinking ethos, McNutt mentioned. It was one of many first districts to put in purple pipe recycling programs within the Nineteen Seventies, and one of many first to reuse strong waste from its Tapia Water Reclamation Facility. During the latest drought, the district designed customized flow-restrictor units to cut back water to wasteful clients.
The OceanWell system “could really revolutionize using Mother Nature to benefit us without having to generate electrical costs and the corresponding greenhouse gas emissions,” he mentioned.
But getting the desalination undertaking previous regulators will probably be a vital hurdle. The California Coastal Commission, the State Lands Commission, the State Water Resources Control Board, the Division of Drinking Water, the Environmental Protection Agency and the U.S. Army Corps. of Engineers are simply a number of the businesses that might be concerned — as will most of the people, which has traditionally been skeptical of desalination.
Tom Luster, an environmental scientist with the California Coastal Commission, mentioned the idea exhibits promise however that he’s wanting ahead to seeing extra information. Two different firms, SeaWell and Oneka, are testing related concepts utilizing floor buoys and wave energy, however OceanWell was the one one he knew of that wishes to put pods on the ocean flooring.
“There is a potential that it will have less of an effect on marine life than the shore-side facilities, but we just don’t know to what degree yet,” Luster mentioned. “And then if there is an impact, how do you mitigate for something like that? How do you make up for the loss of deep-sea marine life? That will be a question we may need to answer.”
Evelyn, of the Sierra Club, shared related reservations concerning the results on marine life. The darkish aphotic zone is residence to plankton and different organisms that would probably get trapped in filters or expertise long-term results from the brine. “I need to see the numbers and I need to see the science,” she mentioned.
She famous that whereas the method is much less energy-intensive than that of services on land, it’ll nonetheless require some quantity of power to push the freshwater from the deep ocean again onto the shore, and to move it to its remaining vacation spot. She mentioned conservation, water recycling and stormwater seize are all methods that ought to be tried first.
However, Evelyn counseled the corporate for reaching out to the Sierra Club and different environmental teams during the last 12 months, and for taking their suggestions and considerations into consideration whereas growing the expertise.
“I am happy to see that there is new technology and there is less harm to marine life, and that the energy output can be less — I am happy for all of those things,” Evelyn mentioned. “But the other side of me always thinks about the fact that when you pull one string in nature, everything is connected. And I do have concerns about how does this affect us 50, 60, 100 years from now.”
Donovan, of GHD, added that whereas the aphotic zone might have much less marine life, the water there may be colder so it might require a bit extra power to drive it by way of the membrane than hotter waters. “But I think all in all, they’re getting some net benefits by being deep and out in that aphotic zone,” he mentioned.
It might be a number of years earlier than the undertaking makes it to the ocean flooring. The partnership with Las Virgenes will enable OceanWell to “stress test” the expertise’s capabilities within the reservoir and accumulate extra information, Simon mentioned. The present aim is to be absolutely operational by 2028, producing an estimated 10 million gallons of freshwater per day.
By comparability, the Carlsbad desalination plant in San Diego County produces 50 million gallons per day, or about 10% of the county’s provide of water. The Doheny desalination plant, accepted by the Coastal Commission final 12 months, will produce about 5 million gallons per day in Orange County when it’s accomplished round 2027.
Luster, of the Coastal Commission, mentioned large-scale, open ocean consumption tasks will proceed to have a onerous time getting state approval due to their excessive power prices and the environmental harm they will trigger. The fee final 12 months rejected plans for the proposed Poseidon desalination plant in Huntington Beach resulting from these and different considerations.
Smaller-scale off-shore programs, equivalent to OceanWell’s, might probably profit from a extra streamlined approval course of in the event that they’re confirmed to work, Luster mentioned. And whereas he doesn’t take into account desalination a silver bullet for the entire state’s water woes, he mentioned it might play a small half in California’s portfolio transferring ahead.
“If they can provide water in coastal areas, that frees up water for inland areas,” he mentioned. “And that in and of itself is going to be a good contribution to the state.”