Tests have uncovered ground water contamination under Hysol Electronics on Don Julian Road. Soil and water studies were begun more than a year ago before the company applied for a county permit to stop using six underground chemical storage tanks.
The Regional Water Quality Control Board is studying ways to clean up the dichloroethane contamination before it reaches drinking water stored in wells.
A spokesman for Hysol, a chemical formulating plant, said dichloroethane was never stored in the tanks. The spokesman said the tanks, which have been removed, had no leaks, so it's possible the chemical came from elsewhere.