Ground‐Water Contamination in Silicon Valley

Abstract

In the southern San Francisco Bay Area, a state regulatory agency carried out a questionnaire survey to determine the locations and characteristics of underground chemical storage and handling facilities at industrial sites in the area. Sampling of soil and ground water were required at sites where underground tanks containing solvents were reported. The survey identified 1,692 tanks at 388 sites. The largest fraction were pretreatment sumps for industrial wastewater, followed by fuel tanks, solvent tanks, and tanks containing corrosives. Solvent tanks were reported at 96 sites. Subsurface investigations resulted in discovery of soil or ground water contamination at 75 of the 96 sites with solvent tanks, or both. Further investigations and remedial actions are underway at these sites, and new regulations have been adopted at the state and local levels to prevent future release of industrial chemicals into soil and ground water.