Pesticides in Streams of the United States--Initial Results from the National Water-Quality Assessment Program

By Steven J. Larson, Robert J. Gilliom, and Paul D. Capel

U.S. GEOLOGICAL SURVEY
Water-Resources Investigations Report 98-4222
Sacramento, California, 1999

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Figure 33. Estimated annual mean concentrations and 5-month time-weighted mean (TWM) concentrations of selected compounds at all 58 sites. The drinking-water criterion value for each compound is shown as a horizontal line. Criteria values for alachlor, atrazine, and simazine are U.S. Environmental Protection Agency's established maximum contaminant levels (MCL). Criteria values for cyanazine and diazinon are USEPA-established health advisory levels (HAL).

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