LA taps contaminated aquifers at Superfund sites to boost drinking water supplies – Daily News


Los Angeles is nearing completion of a $600 million project in the East San Fernando Valley that will turn contaminated groundwater from Superfund sites into drinking water for 261,000 homes annually.

The three new treatment facilities, which are expected to come online in the second half of 2023, will produce up to 87,000 acre feet (about 28 billion gallons) of potable water in a typical year, according to the Los Angeles Department of Water and Power.

The project is a major step toward achieving the city’s goal of sourcing 70% of its water from local sources by 2035, and a move to reduce the city’s dependence on imports. Today, about 90% of the water Angelenos consumes comes from elsewhere.

Evelyn Cortez-Davis, Director of Hydraulic Engineering and Technical Services at LADWP, said: “It’s been closer to 10% for the last few years.”

Local supply dropped to 4.2% during the 2017-18 drought, according to city data. It has not exceeded 20% since 1999.

Two of the new facilities are located in North Hollywood, with the largest, which handles about half of the water, at Tujunga Spread Grounds in Pacoima.

the future of water

Today, LA uses about the same amount of water as it did in the 1970s, but has about a million more people, says Cortez-Davis. But conservation alone isn’t enough to ensure future water reliability, she said.

To reach the ambitious goal of 70%, the city will optimize rainwater collection, maximize the use of recycled water, and replace wells that have been closed for decades due to pollution, such as those in the San Fernando Valley. We are developing a number of projects to resume. The San Fernando Basin is the largest aquifer in the LADWP’s footprint, but more than two-thirds of his 115 wells are unused due to groundwater contamination dating back to the 1940s.

The San Fernando Valley Superfund is a federal classification of the most polluted locations in the country and consists of four segments from Pacoima to Burbank to Glendale. According to the EPA, two of his neighboring cities already have treatment facilities running on the part, allowing him to pump 9 million gallons of water from the Superfund site part of the 7 million to 9 million gallons every day.

pollution source

Much of the basin’s pollution is due to solvents and other chemicals that seeped into the ground decades ago when the area was a haven for the aerospace industry and other manufacturers. For years, the LADWP and EPA have tried to pin down those responsible. Some companies, such as Honeywell and Lockheed, have already settled with the city. Some have become more difficult to identify as time has passed.

The EPA inspected over 400 different facilities to try to identify the responsible party.

As part of the settlement, Honeywell and Lockheed agreed to finance the treatment of up to 6.3 billion gallons of water each year. LADWP estimates that this could save the city as much as $800 million over the life of the deal.

But rather than wait years to track down all the culprits, the LADWP chose to aggressively build treatment facilities, Cortez-Davis said. That decision will not prevent the city from seeking reimbursement from identified responsible parties in the future, she said.

“It’s in our best interest to make sure this restoration happens sooner or later,” she said.

Persistent drought and climate change in the region have made imported water less reliable, and the city wants greater control that can only be obtained by managing the water source itself.

That shift doesn’t come cheap. About half of his $600 million price tag for the three facilities is funded by Proposition 1, his $7.5 billion water bond bill passed by California voters in 2014.

“Those plans are underway that require significant investment, but we are talking about investing in the future of long-term water reliability,” she said.

According to the state, this kind of work is essential to regenerating local water sources. Proposition 1 allocated his $670 million grant, administered by the State Water Resources Board, to projects specifically aimed at preventing and cleaning up groundwater pollution.

“Water supplies in this region are increasingly threatened by drought and climate change, so we are taking steps to protect drinking water and other beneficial uses,” said Norma Camacho, chairman of the Los Angeles Area Water Management Board, in a statement. And it’s important to clean the aquifer,” he said. “Our board is actively taking steps to rehabilitate contaminated sites and expand our water resistant portfolio.”

A LADWP field worker installs a lamp sleeve in a UV reactor. The sleeve is a transparent tube that protects the lamp from water.  Tujunga has 6 UV reactors with 384 lamps per reactor.  (Provided by LADWP)
LADWP field workers install lamp sleeves in UV reactors. The sleeve is a transparent tube that protects the lamp from water. The Tujunga plant has 6 UV reactors with 384 lamps per reactor. (Provided by LADWP)

water treatment method

Chemicals identified in the basin include trichlorethylene, perchlorethylene, and 1,4-dioxane, according to EPA and LADWP. To remove contaminants, the pumped water is mixed with hydrogen peroxide, filtered to remove sediment, and passed through an ultraviolet reactor where exposure to UV lamps breaks down the compounds.

The water is then passed through a granular activated carbon filtration system (think giant Brita filter) to remove excess hydrogen peroxide and other leftovers. Once treatment is complete, the water finally goes through the typical disinfection and fluoridation process used in all city drinking water.

Other Superfund Sites

The idea of ​​sourcing drinking water from contaminated Superfund sites may sound intimidating, but similar projects have existed elsewhere in Southern California for decades.

Most of the San Gabriel Valley sits above four Superfund sites containing approximately 44 square miles of contaminated groundwater.

According to the EPA, since 2001 water utilities in the region have installed 14 different groundwater treatment systems that pump and treat approximately 56 million gallons of potable water per day. Another project in the design phase will add an additional 2.5 million gallons of potable water in total.

According to a fact sheet published by the EPA, various utilities serving the San Gabriel Valley have collectively treated more than 200 billion gallons of contaminated water and removed more than 100,000 pounds of contaminants. Total costs were approximately $600 million as of May 2021.

Pollutants found in the San Gabriel Valley are similar to those in the San Fernando Valley.

In Pasadena’s Raymond Basin, the local water system cleans up to 13 million gallons of water per day from the Jet Propulsion Laboratory Superfund site, named after the NASA facility that caused the contamination, according to the EPA. It can be used.

Elsewhere, San Bernardino is processing more than 28 million gallons per day from the Newmark Groundwater Contamination Superfund site for use in drinking water, officials said.

In a statement, the EPA explained that efforts to restore polluted watersheds are “essential to providing a safe and clean source of drinking water for residents and businesses in and outside of Los Angeles County.” The agency will reassess cleanup operations every five years to ensure treatment facilities continue to meet safe water standards.



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