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DWP Expects Federal OK to Clean 40 Wells : $12-Million Project for Tainted Ground Water

March 26, 1987|ANDREW C. REVKIN | Times Staff Writer

After lengthy delays, a $12-million, two-pronged program to clean up contaminated ground water in Glendale and the San Fernando Valley is expected to receive federal approval and funding next month, officials said this week.

Final approval by the Environmental Protection Agency is nearly assured for a broad investigation into the sources and extent of solvent-tainted ground water that has polluted about 40 of 110 municipal water wells in the area, said Duane Georgeson, assistant general manager of the Los Angeles Department of Water and Power.

In addition, a meeting of local and federal water officials in Los Angeles was told that the second step in the project--constructing a $4.4-million aeration tower to purge solvents from water beneath North Hollywood--has cleared an important hurdle with approval by the EPA of a final design for the tower.

The EPA has given the DWP overall responsibility for both the study and the tower project.

Contamination Spreading

Since 1980, excessive levels of two industrial solvents, trichloroethylene and perchloroethylene, have been found in a growing number of wells. The greatest concentrations were found in wells near an industrial corridor through North Hollywood and Burbank. On average, two new wells are contaminated each year, according to the DWP.

Four separate clusters of wells--operated by Los Angeles, Burbank, Glendale and the Crescenta Valley County Water District--have been included by the EPA on the list of polluted sites around the nation that are eligible for cleanup money through the federal Superfund. The agency pays for cleanup projects with revenues generated by special taxes on industry.

The ground-water study will in part focus on determining which businesses are responsible for the contamination, Georgeson said. The responsible firms then must pay for cleaning the solvent-tainted water, he said.

The scope of the pollution study has grown steadily over the last two years. It now includes the drilling of hundreds of shallow wells to test for chemical vapors in soil, and dozens of deep wells to gather water samples, Georgeson said. Computers will be used to analyze the migration of pollutants within the vast reservoir of water held in layers of sediment, he said.

Budget for Study Grows

The study's budget has likewise grown, from an early estimate of $2.4 million in 1985 to the current planned $7.6 million, according to DWP figures. The entire cost is to be paid by the Superfund.

"We're really happy about that kind of funding," said Raymond Marsden, engineer with the Crescenta Valley Water District, which serves La Crescenta and La Canada Flintridge.

Wells in the area provide 20% of Glendale's drinking water, and that ground water is mixed with water from other sources. Still, the EPA study is very important, said Michael Hopkins, the city's water services director. "Nobody wants to write off a local supply of water," he said. "We want to stop further contamination and proceed with cleanups."

The link to Superfund was one of the key factors delaying the project, Georgeson said. In 1985, when EPA and DWP first negotiated an agreement to undertake the study, no Superfund money was available. Only late last year was money made available when Congress reauthorized the Superfund program after a six-year lapse, Georgeson said.

Since then, the first $2.1-million contract for the study has been negotiated, although it will not be signed until the EPA provides the money, he said.

The tower project had to pass hurdles of its own. More than two years in the planning, the aeration tower has undergone a series of design changes to ensure that the tower cleans water to within state standards and does not pollute the air with chemicals removed from water.

Plans for the project call for contaminated water to be drawn from eight shallow wells in the contaminated zones and piped to the top of a 48-foot tower, then dropped through an upward blast of air that will cause any dissolved solvents to evaporate. The vapor will then be caught in a carbon filter.

The design approved by the EPA and issued this month calls for two more feet of filtration material to ensure that all but the tiniest traces of the solvents are removed, said Patti Cleary, an EPA official from San Francisco.

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