NRDC REPORT ON US WATER. “A 1994 study estimated that some 14.1 million Americans drank water contaminated with the pesticides atrazine, cyanazine, simazine, alachlor, and metolachlor. The manufacturers of these agricultural herbicides have shown that these chemicals may cause cancer, birth defects, and genetic mutations.”
http://www.nrdc.org/health/kids/ocar/chap7.asp