A long-awaited study to find ways to isolate and clean up contaminants in San Gabriel Valley ground water will get under way in October, a federal Environmental Protection Agency official has said.
Neil Ziemba, environmental engineer at the EPA regional office in San Francisco, said a contractor will be hired this summer to carry out the project, which will take up to three years and cost up to $5 million.
Ziemba said the study cannot begin until a program to sample 170 of the 400 wells in the main San Gabriel Basin for a wide range of volatile organic compounds is finished. Ziemba said EPA's analysis of the samples will be completed by October, and then work can begin on strategies for isolating and removing the industrial solvents that have seeped into the ground water.
The basin, which stretches from Monterey Park to San Dimas, supplies water to more than a million people, but does not include the valley's two largest cities, Pasadena and Pomona.
Ziemba said test results are too fragmentary now to determine whether the ground water contamination, first discovered in 1979, is getting better or worse. There are 60 wells with so much contamination that they cannot be used unless the water is treated or blended to meet state health requirements. Several wells were closed recently because of newly discovered contamination, but water quality in other wells has improved, suggesting that the contamination may be moving, rather than increasing, Ziemba said.
The contamination involves trichloroethylene (TCE), perchloroethylene (PCE) and other chlorinated hydrocarbons used as industrial solvents. The compounds have caused cancer in laboratory animals and are suspected carcinogens in humans.
State, U.S. Superfunds
The ground water contamination problem in the San Gabriel Valley has qualified for funding from both the state and federal superfunds, but Assemblywoman Sally Tanner (D-El Monte), who has been the key legislator pushing for cleanup, recently complained that the project is moving so slowly that it "is difficult . . . to see what progress has been made."
Ziemba conceded there was a delay of several months in sampling wells. The Environmental Protection Agency planned to sample 125 wells last year, but then discovered that the state required water agencies statewide to perform similar tests this year. Ziemba said his agency redesigned its program to avoid duplication and to supplement the state effort. This saved money but delayed the work.
Ziemba said results from the sampling of wells will pinpoint pockets of contamination and determine where to focus the cleanup study. The contractor hired to conduct the study will drill monitoring wells, take soil samples and design plans to clean up and protect ground water.
Looking for Sources
Efforts also will be made to find the sources of contamination by examining records, analyzing underground water flow and identifying companies that handle industrial chemicals.
The state Department of Health Services originally planned to supervise the cleanup study, but relinquished that task to the EPA and recommended that the federal agency hire the Upper San Gabriel Valley Municipal Water District, an organization of water producers, to do the work.
Ziemba said the water district will play a role in the study, but the bulk of the technical work will be done by one of the EPA's national contractors. The EPA plans to award a national contract for environmental work in June and either that winning bidder or another company already holding a national contract will be given the San Gabriel Valley project, Ziemba said.