Introduction
Introduction
Pollution of the nation's streams, rivers and lakes has been dramatically reduced sincepassage of the 1972 Clean Water Act and other landmark environmental legislation. But while the most blatant, visible discharges of industrial wastes and sewage have been eliminated, pollution remains a problem. According to the , up to 40 percent of U.S. waters are still too dirty for swimming or fishing. Today the main culprit is runoff, which occurs when rainwater and snowmelt carry excess nutrients, animal waste and toxic chemicals from farms, city streets and construction sites into nearby streams. The EPA has proposed new rules to curtail water pollution, but critics charge that they are scientifically unsound and unfair to farmers and ranchers.
