They were probably killed off by the chlorine which the San Jose Water District uses to disinfect the drinking water supply, following federal regulations. It was as if he'd discovered that there is really no magic. It also changed the way she felt about the tap water in her household. Health concerns, she says, are an important factor. The result of this contamination is 29 identified Superfund sites in Silicon Valley, more than any other in the nation.
Most local water is pumped from an aquifer deep under the valley floor.
The aquifer is protected by a thick layer of clay, which fairly effectively seals it off from above. But that barrier has been broken. Leftover contamination from the early chip-making industry's careless use of solvents, first discovered after the notorious Fairchild case 15 years ago, still may be present in the underground water supply. More recent solvent leaks from dry cleaning operations may also have found their way into the aquifer. Together, the plants provide drinking water to 1.6 million drinking, watering and flushing Silicon Valley residents.