Saying it needs to evaluate all options for new sources of drinking water, Silicon Valley’s largest water district is studying a plan to build the first seawater desalination plant along the shores of San Francisco Bay.

The Santa Clara Valley Water District, a government agency based in San Jose, has approved spending $1.7 million for Black & Veatch, a Walnut Creek firm, to conduct an engineering feasibility study over the next 12 months for a project near the bay’s shoreline in Palo Alto, Mountain View or San Jose.

Under the proposal, which is still in the early stages, the plant would take between 20 million to 80 million gallons of water a day from the bay, run it through filters to strip the salt out and serve from 10 million to 40 million gallons a day of freshwater to South Bay homes and businesses. That would provide about 11,000 to 44,000 acre-feet of water per year, enough for between 100,000 and 500,000 households.

The salty brine left over would be blended with treated wastewater from one of the South Bay’s sewage treatment plants to reduce its salinity and be released back into the bay.

“People ask us about desalination all the time,” said Tony Estremera, a member of the Santa Clara Valley Water District’s board of directors. “Can we really do it? We don’t know. It’s worth looking at. We really do need to do a serious look at it, and this is a substantial look.”

In theory, desalination can provide an endless supply of water. In 2015, crews built a $1 billion desalination plant in Carlsbad, in San Diego County. It provides 54 million gallons per day — nearly 10% of the drinking water for San Diego. It is the largest plant in North America.

But desalination is also the most expensive type of water to produce. The San Diego County Water Authority pays $3,400 an acre-foot for the Carlsbad water — more than double the cost of water it imports from other sources, and up significantly from the $2,200 it paid when the plant opened a decade ago.

By comparison, the Santa Clara Valley Water District pays about $400 an acre-foot to the federal and state government for water it draws from the Delta. However, that water is not as reliable during droughts.

Why is it so expensive? Desalination plants run 24 hours a day, blasting water through membranes at pressures higher than a fire hose, and use huge amounts of energy.

Desalinated water is far more costly than recycling wastewater, repairing leaky underground pipes, expanding groundwater storage, or giving people rebates to voluntarily remove their lawns or buy water-efficient appliances, experts say.

“This would be the first seawater desalination plant built in the Bay Area,” said Heather Cooley, director of research for the Pacific Institute, a nonprofit water research organization in Oakland. “We haven’t seen others because we have cheaper alternatives with fewer environmental impacts.”

The district proposal is likely to face significant environmental opposition because it would be near, or inside, the Don Edwards San Francisco Bay National Wildlife Refuge.

David Lewis, executive director of Save the Bay, an environmental group in Oakland, said that building pipes into a national wildlife refuge to draw millions of gallons of water a day from sensitive wetland areas that are home to endangered species would almost certainly cause a major controversy.

“The public has a deep love for the bay and has made a big investment in protecting these parts of the shoreline,” he said. “The public would not likely welcome new development of this type in that area.”

Several alternatives have been tried in the past.

In 2009, many of the largest water agencies in the Bay Area paid to construct a pilot desalination plant in Bay Point, just west of Pittsburg. It ran for more than a year.

But the group, which included the Santa Clara Valley Water District, the San Francisco Public Utilities Commission, the Contra Costa Water District and the East Bay Municipal Utility District, dropped the idea in 2012.

“The cost of the water was higher than other sources for us,” said Andrea Pook, a spokeswoman for EBMUD. “And the environmental permitting would have been challenging.”

Similarly, the Marin Municipal Water District proposed building a desalination plant on the bay near San Rafael in 2009 but shelved the plan after Marin voters approved a ballot measure in 2010 saying desalination facilities couldn’t be built without voter approval.

Building such a plant in the South Bay, which is shallow and subject to limited tidal action, would require 14 permits from federal agencies and 8 from state agencies, according to a brief environmental feasibility study that the Santa Clara Valley Water District commissioned last year.

GEI Consultants, an Oakland firm that did the study, evaluated 13 alternatives along the San Jose, Mountain View and Palo Alto shorelines. The most feasible options, it found, were to draw in water from underground pipes in the bay off Palo Alto or Mountain View. The most likely site for a desalination plant, however, is in Alviso, the study concluded, where there is more land than other possible sites near Moffett Field and the Palo Alto Baylands. The brine could be disposed of in deeper waters in the middle of the bay, or in a marsh after being blended with treated wastewater, the study found.

The cost would be in the hundreds of millions of dollars if not more than $1 billion. Specific estimates will be part of the engineering study, Estremera said.

There are 12 ocean desalination plants in California now. Most are small and serve military bases, power plants and other facilities, like the Monterey Bay Aquarium. Apart from the Carlsbad plant, there are plants in Santa Barbara and Catalina Island. Two years ago, the Coastal Commission rejected a large plant at Huntington Beach, citing environmental concerns.

In November 2022, however, the commission approved a permit for a $330 million seawater desalination facility in Marina, in Monterey County. That plant, at the site of a former sand mining factory, will produce 5 million gallons of water a day at a cost of $6,000 an acre-foot for the water-starved Monterey Peninsula.

The commission also approved a plant in Dana Point which will produce 5 million gallons a day. It would be built by the South Coast Water District in Laguna Beach and is expected to open in 2028.

“This study is really a response to the community, and our public officials,” Estremera said. “We want to take a good serious look at this and answer once and for all whether it’s possible here.”

Originally Published: July 23, 2024 at 6:00 a.m.

The Dallas Cowboys are projected to be one of the better teams in the NFC this season. Many of the other top teams in the conference are playoff teams from a year ago and are expected to be right in the thick of things again this year. To get a feel for what kind of challenges the Cowboys might face this season, we’ll run through their toughest competitors, starting with the reigning NFC champs.

SAN FRANCISCO 49ERS

Head Coach: Kyle Shanahan, seven seasons, 64-51 (.557)

The San Francisco 49ers are the team to beat in the NFC. They have advanced to the NFC Championship game in four of the last five years, twice moving on to the Super Bowl. They have stars on both sides of the ball with studs like Christian McCaffrey, Nick Bosa, Deebo Samuel, and Fred Warner. They also benefit from the emergence of seventh-round pick Brock Purdy who is only halfway through his super-cheap rookie deal. The Niners are poised to make some noise once again in 2024.

2023 Statistics

Record: 12-5, 1st in the NFC West, the top seed in the NFC playoffs

Offense rank: Points (3rd), Yards (2nd), passing efficiency (1st), and rushing efficiency (4th)

Defense rank: Points (3rd), Yards (8th), passing efficiency (5th), and rushing efficiency (14th)

2023 Leaders

Passing: Brock Purdy = 69.4 % completion, 4,280 yards, 31 TDs, 11 INTs

Rushing: Christian McCaffrey = 1,459 yards (5.4 ypc), 564 yards receiving, 21 total TDs

Receiving: Brandon Aiyuk = 75 catches for 1,342 yards and 7 TDs

Sacks: Nick Bosa = 10.5

Tackles: Fred Warner = 132

Interceptions: Charvarius Ward = 5

Best offensive weapon

The 49ers re-upped on their most talented offensive weapon adding two more years to McCaffrey’s contract, keeping him in San Francisco through the 2027 season. This move welcomes criticism from the “running backs don’t matter” coalition, but McCaffrey might be an anomaly. After never missing a game his first three years, he struggled to stay healthy, missing 22 games over the next two seasons. But since being traded to the 49ers, his career has been revitalized. Shanahan has been a run-producing genius since joining the team and now has the league’s most explosive runner.

Best defensive weapon

Before the 49ers were this NFC force, they were cellar-dwellers in the NFC, going five straight seasons without a winning record. This level of suckitude rewarded them with a top-10 pick in four consecutive drafts. Their top draft selection was the no. 2 overall pick, Nick Bosa, in 2019. The Ohio State edge rusher has been a force since entering the league and finished with 18.5 sacks in 2022 when he won Defensive Player of the Year (beating second-place finisher Micah Parsons). Bosa is the highest-paid player on the 49ers as he is in year two of a five-year, $170 million deal.

Notable losses

The 49ers came out of the offseason unscathed as they didn’t lose any huge contributors. Their biggest losses were suffered along the defensive line as some former blue-chippers are now gone. Former fourth-overall pick Clelin Ferrell had a solid year for them last year, starting all 17 games. He now joins Dan Quinn in Washington. Arik Armstead has been a mainstay at DT for them over the last several years but signed with Jacksonville. The 49ers traded for Chase Young (second-overall pick in 2020) and Randy Gregory last year, but both signed elsewhere this offseason.

Notable additions

Just because the 49ers defensive line was picked through in free agency doesn’t mean it’s now a weakness. The team was aggressive in finding some quality replacements. They signed veteran edge rusher Leonard Floyd (ninth overall in 2016) to a two-year, $20 million deal. Floyd hasn’t missed a game in six years and has recorded at least nine sacks in each of his last four seasons. They also added a run-stopping defensive end Yetur Gross-Matos to a two-year, $18 million deal. And to help strengthen the middle, they added a defensive tackle Cowboys fans might remember as they traded a seventh-round pick to the Houston Texans for Maliek Collins. He is coming off one of his better years in the league with a career-high in tackles (41) and sacks (5) last year.

Top draft pick

The 49ers picked at the end of the first round but took advantage of the rich wide-receiving class by selecting Ricky Pearsall. This could be a preemptive strike to replace Aiyuk whose future in San Francisco is uncertain as he looks for a new deal.

2024 game against Dallas: Week 8, Sunday Night Football