Survey for Triazine Herbicides in Well Water, Glenn County, 1986

摘要

In January, 1986, the Agricultural Commissioner of Glenn County reported the presence of atrazine in a sample of domestic well water. Department of Food and Agriculture staff sampled 137 wells in a 37 square mile area surrounding the original well to confirm and delimit the area of contamination. Of the 137 wells sampled, 34 contained atrazine. In addition, simazine was found in 17 wells and prometon was found in 10 wells. Residues ranged in concentration from 0.1 to 5.9 ppb. Forty-four of the wells sampled contained one or more of the triazine herbicides. The presence of the chemicals was confirmed by a second laboratory and two alternate analytical methods. An area of contamination was not determined, since low levels of residues were found in wells throughout the study area. Possible sources of contamination included normal uses of the pesticides for agricultural crops, rights-of-way, and non-crop areas. A pesticide wash area located in the vicinity was probably not the primary source of contamination.