Los Angeles looks to a contaminated aquifer for new water

As drought and climate change ravage California’s once reliable drinking water supply, Los Angeles officials are targeting a relatively new, nearly untapped resource for the city’s 4 million residents: the Superfund site in their own backyard.

Nearly 70% of the city’s 115 wells in the San Fernando Valley aquifer — the largest such basin under the jurisdiction of the Los Angeles Department of Water and Energy — have been unused for decades after dangerous contaminants entered the aquifer.

Now the city is on the verge of completing a massive $600 million plan to bring this resource back online. The groundwater remediation project, centered on three treatment plants in the San Fernando Valley, will essentially create giant filters for the city’s toxic plume, allowing Angelenos to regain full access to up to 87,000 acre-feet of water each year, or nearly a fifth of what they consume.

Some say it can’t happen soon enough.

“The drought is making groundwater even more important as a source of water for us – that’s what really matters,” said Anselmo Collins, senior assistant general manager at DWP. “The ultimate goal is to be able to extract this water and feed it into the drinking water system.”

The project took years, but the problem can be traced back even further.

In the mid-20th century, a post-war boom transformed the San Fernando Valley into a fertile home for trade and manufacturing, including major players in the aerospace, automotive, and defense industries. But when these companies began storing and disposing of metals, solvents and other waste in the area, known carcinogens such as trichlorethylene, perchlorethylene, hexavalent chromium and 1,4-dioxane seeped into the valley’s aquifer.

The extent of the problem was not fully revealed until the Safe Drinking Water Act of 1974 mandated increased testing and monitoring standards for drinking water, according to Larry Sievers, the Environmental Protection Agency’s remediation project manager. By this point, the pool was so contaminated that it received the agency’s dreaded Superfund award, indicating a site so polluted that long-term cleanup is needed.

“Superfund sites are like the worst of the worst,” Sievers said. “Every once in a while we get a place like the San Fernando Valley that’s just massive in scale.”

A group of above ground closed tanks standing on dirt outdoors.

The Los Angeles Department of Water and Power’s Tujunga Spreading Grounds facility, where the agency will treat contaminated groundwater from the San Fernando Valley basin. The groundwater was contaminated years ago after toxic chemicals seeped into the basin.

(Robert Gauthier/Los Angeles Times)

In fact, the vast basin sits beneath several communities, including large parts of Los Angeles, Burbank, and Glendale. More than a dozen organizations are involved in the cleanup, Sievers said.

But most of the water rights in the basin are owned by the DWP, which for years has searched in vain for those responsible to take responsibility for the pollution.

“The challenge we have with the San Fernando Basin is that it’s the largest basin — the one that we have the most claims to — but it’s also the contaminated one,” Collins said.

The city has long relied on other supplies to make ends meet, including water imported from the Owens Valley, Northern California and the Colorado River via a network of ancient aqueducts. But as drought depletes those sources, Los Angeles is being forced to undergo a major overhaul of its water infrastructure.

A cluster of enclosed above ground tanks and buildings on dirt outdoors with hills above in the background.

The Los Angeles Department of Water and Power’s Tujunga Spreading Grounds facility, where the agency will treat contaminated groundwater from the San Fernando Valley basin.

(Robert Gauthier/Los Angeles Times)

Currently, only 10% of the water consumed by the city comes from the region. The DWP hopes that figure will rise to 70% by 2035 when the filtration plants and other major projects are completed.

“Not only does it make us more drought-proof when you have the water, especially in the aquifer, but it also makes us a little bit more earthquake-proof,” Collins said. “Because it’s not a matter of if, but when we have an earthquake and the aqueducts cross the San Andreas Fault.”

Mark Gold, a Los Angeles water expert and associate professor at UCLA’s Department of Environment and Sustainability, said it pained him to think that such a valuable resource went untapped for almost four decades.

“The only people who got paid were the lawyers and the people who did the groundwater studies, but at the end of the day the public didn’t get their supply,” Gold said. He noted that shrinking state and federal supplies and rising water costs made it more urgent than ever to get the basin back into the mix.

“To say that in the city of Los Angeles we should get a quarter of our water supply from groundwater is not far fetched at all,” he said. “Sustainable local water is where we need to go… and groundwater is a big part of that.”

In fact, restoring the San Fernando Valley aquifer is a key part of LA’s future plan, which includes major investments in water recycling and stormwater harvesting, as well as an persistent pursuit of conservation, all in the name of reducing reliance on imported supplies.

But removing decades-old contaminants from a major municipal water source is a massive undertaking. According to Evelyn Cortez-Davis, director of water engineering and technical services at DWP, the water is pumped from the ground and then passed through a series of filters and treatments.

She recently walked through the steps during a tour of the Tujunga Spreading Grounds facility in Sun Valley, which when completed in 2023 will house the largest of the three project sites.

A man wearing a hard hat near a cluster of filter tanks outdoors.

DWP Civil Engineer Jose Rubalcava near a cluster of filter tanks at the Tujunga Spreading Grounds facility.

(Robert Gauthier/Los Angeles Times)

First, the pumped water is cleaned with hydrogen peroxide and then forced through filters to remove sediment like dirt and sand, Cortez-Davis said. Next, the water is bombarded with hundreds of UV lamps to disinfect it. Finally, it is passed through huge tanks of granular activated carbon, which adsorbs any remaining hydrogen peroxide and removes other harmful compounds.

Only then is it ready for the standard treatment that all LA tap water receives, including doses of chlorine, ammonia and other additives. The treated water will meet all federal and state drinking water standards, Cortez-Davis said.

Filter tanks in a row outdoors.

Filter tanks at DWP’s Tujunga Spreading Grounds facility.

(Robert Gauthier/Los Angeles Times)

She noted that because of the way the city is routed, the water doesn’t stay in the San Fernando Valley, but “becomes integrated into the overall distribution system,” which benefits almost all of Los Angeles.

“The city’s focus has been on conservation for so long that we’re doing it really, really well,” Cortez-Davis said as she walked through the site. “What I think people sometimes miss is how reliant we are on groundwater during dry spells and the fact that so many of our wells have been affected for so long.”

But part of the reason the site has remained unused for so long is that officials have been embroiled in legal battles for years, working to find those in charge who could help pay for the cleanup costs.

Some big-name companies, including Honeywell and Lockheed Martin, have already agreed to take possession of some of the decades-old chemicals, according to the DWP, and have pledged to fund cleanup efforts or compensate for the losses in kind. Others have yet to be identified, and some may not exist all these years later.

“As stewards of our aquifer, it is then up to us to ensure that we continue to have access to that aquifer as it is a critical supply,” Cortez-Davis said. Rather than waiting for a fix, “the alternative was for LA taxpayers to do this proactively and reclaim our resources.”

That means Angelenos shoulders some of the cleaning costs, she said, although the EPA and the cities of Burbank and Glendale also treat water in other parts of the basin.

“It’s sensitive and we all rely on it,” said Richard Wilson, deputy general manager of Burbank Water and Power. “We have to be good stewards of the water we import, the water we have in the ground and it’s a regional issue, especially given the drought.”

In Los Angeles, nearly half of the project’s funding — about $310 million out of $634 million — comes from state grant funds through Proposition 1, a $7.5 billion water bond passed by voters in 2014.

Joe Karkoski, deputy director of the financial assistance division at the State Water Resources Control Board, which manages the funds, said it is exactly the type of project the bond was created for.

“Because they’re able to clean up groundwater pollution, they’re bringing back more of their municipal wells that had to be shut down,” he said. “This means their portfolio is changing over time – they are becoming less dependent on surface water… and more dependent on local groundwater resources.”

Other projects are also in the works, including the dual use of the Tujunga site as an improved dispersal facility to capture more rainwater when it rains. With some treatment plants already operating, the city of Tujunga’s ability to capture stormwater has doubled from 8,000 acre-feet per year to 16,000, or about 5 billion gallons, officials said.

UCLA’s Gold said the scope and scale of projects in the San Fernando Valley gives him “a tremendous amount of hope” for the city’s water future.

“We get a reliable local water supply,” he said, “and we need a lot more of that here in the state of California.”

https://www.latimes.com/california/story/2022-12-12/los-angeles-looks-to-a-contaminated-aquifer-for-new-water Los Angeles looks to a contaminated aquifer for new water

Alley Einstein

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