An integrated approach for source water protection and awareness in rural agricultural watersheds

Atrazine, a triazine herbicide and chemically an organochlorine, is used worldwide for controlling broad leaf weeds in corn, sorghum, and wheat. Atrazine is regulated by the Safe Drinking Water Act (SDWA) through the United States Environmental Protection Agency (U.S. EPA) and has a Maximum Contaminant Level (MCL) of 3.0 parts per billion (ppb). Atrazine has been found to contaminant public water supplies in agricultural watersheds and is under special review by the U.S. EPA. Transport of atrazine to streams, rivers, groundwater, and reservoirs occurs primarily by nonpoint source runoff from fields. However, inadequate disposal and atmospheric deposition can increase transport to water supplies. During the period from 1999, studies have been ongoing in rural watersheds in western Kentucky to quantify both the distribution and occurrence of atrazine. Beginning in 2001, farmers in two rural watersheds agreed to reduce the usage of atrazine and work with stakeholders to assess how use reductions would affect the distribution and occurrence. The goals of this study were realized as we used the assessment of the environmental occurrence and distribution of atrazine as a tool for public health protection and source water awareness in agricultural watersheds. Results of the study were incorporated in a statewide education campaign for corn producers and professional pesticide applicators conducted through the Kentucky Pesticide Workgroup.