The National Water-Quality Assessment Program and the U.S. Environmental Protection Agency recently completed a two-year pilot monitoring program for assessment of pesticide concentrations in drinking water.
The National Water-Quality Assessment Program (NAWQA) and the U.S. Environmental Protection Agency recently completed a two-year pilot monitoring program for assessment of pesticide concentrations in drinking water. The program was designed as a first step toward a long-term goal of characterizing human exposure to pesticide residues in drinking water derived from surface-water sources. Reservoirs were selected for sampling because they are important sources of drinking water and because the integrate pesticide loadings within their watersheds.
Twelve water-supply reservoirs and community water systems were sampled, ranging in size from 120 to 92,600 acre-foot normal capacity, with contributing watersheds ranging from about 3 to 785 square miles. The sites are located in California, Indiana, Louisiana, Missouri, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, South Carolina, South Dakota and Texas. Samples were collected from the raw water intake and the finished water tap located at the entry point to the distribution system. Each site generally was sampled every quarter, with bi-weekly sample collection during a four-month period coincident with extensive pesticide applications.