Water-Cleaning Proposal Advances : Officials OK Money for Key Part in Anti-Pollution System

A pilot project to clean up contaminated San Fernando Valley ground water moved a step forward Thursday when Los Angeles water officials approved a contract for a key component of the $1-million treatment system.

The system will use ozone and hydrogen peroxide to remove chemical solvents from ground water in North Hollywood, where tainted city water wells have been designated for cleanup under the federal Superfund program. The $450,000 contract approved by the Board of Water and Power Commissioners, which sets policy for the Department of Water and Power, is for purchase of an ozone generator.

The approval demonstrates the DWP’s “goal of utilizing efficient and environmentally sound treatment technologies to remove contaminants from the San Fernando Valley ground-water basin,” said board president Rick J. Caruso.

The treatment system, designed to cleanse about 3 million gallons of water per day, is to be completed next summer next to two contaminated DWP wells in the 11400 block of Vanowen Street. DWP officials hope that the system will prove better than air stripping, a more conventional treatment method already in limited use in North Hollywood.

May Ask Help

The DWP expects to go it alone on the pilot project, but may later ask the U. S. Environmental Protection Agency to fund a full-scale ozone-peroxide system as part of the Superfund cleanup.

“If it does prove to be as effective as we think, we will try in the future to expand its use and possibly get Superfund assistance for its use at other sites,” DWP spokeswoman Mindy Berman said.

A large area of the East Valley has been designated for Superfund cleanup because of pollution of wells tapped by the DWP, the cities of Burbank and Glendale, and the Crescenta Valley County Water District. The principal contaminants--the solvents trichloroethylene and perchloroethylene, or TCE and PCE--are present at low levels, but many wells have been idled to assure that tap water meets health standards.

The DWP relies on Valley ground water for 15% of the city’s water supply. Valley water is blended with supplies from the Owens Valley and served to customers on the south side of the Santa Monica Mountains.

Air-Stripping Plant

Near the site of the ozone-peroxide project, the DWP in March began operating a $2-million air-stripping plant built with Superfund money. The pilot stripper treats up to 3 million gallons of tainted water per day, releasing the solvents as vapors.

The EPA is also planning a $70-million complex of air-stripping towers, capable of treating 18 million gallons a day, near a cluster of highly contaminated Burbank wells. The agency is negotiating to raise the money from 31 Burbank-area companies it says are “potentially responsible” for the pollution.

Air strippers typically capture the released vapors in carbon filters, which must be recycled or disposed of as hazardous waste.

The DWP is touting ozone-peroxide treatment because it reduces chemical pollutants to harmless byproducts--water, carbon dioxide and chloride--rather than converting them to another form of hazardous waste.

‘Below Detection Limit’

The DWP is going ahead with the project without a full environmental impact report despite acknowledging at a public meeting last year that the process could create tiny traces of other hazardous chemicals. The DWP said the byproducts would likely exist only in the “parts per trillion range, which is below the detection limit.”

The DWP also announced Thursday that its treated water during the past 12 months has contained an average TCE level of 1.5 parts per billion. In past years, average concentrations have been closer to the health standard of 5 p.p.b.

Experts say those who drink water containing 5 p.p.b. of TCE over a lifetime theoretically raise their risk of getting cancer by one chance in 1 million.