USGS investigations reveal widespread contamination of US water resources

Information now available from the first phase of the National Water Quality Assessment (NAWQA) Program shows that pesticides are widespread in US streams and groundwater, occurring in geographic and seasonal patterns that follow land use and related pesticide use. The study also indicates that the most heavily used compounds account for most detections and that most pesticides found in the environment usually occur as mixtures. These and other findings are based on the most extensive data ever collected for such a wide range of pesticides and stream and groundwater locations.