Characterization of the study areas for the pilot study: agricultural chemicals in rural, private wells in Illinois

Because pesticide use is widespread in rural areas and groundwater is the major source of drinking water in rural areas, the Illinois State Geological Survey (ISGS) and the Illinois State Water Survey (ISWS) developed recommendations for a statewide survey of agricultural chemicals in rural, private water wells in Illinois. This pilot study was undertaken to develop and evaluate field, analytical, and database management methodologies that would be applied in a statewide survey. Specifically, the pilot study evaluated the validity of using the potential for contamination of shallow aquifers as the stratification variable by assessing the occurrence of agricultural chemicals in rural, private wells in representative hydrogeologic settings in Illinois. Additional objectives included field testing well selection procedures; conducting well user interviews; training Illinois Department of Agriculture and Illinois Department of Public Health personnel in sampling procedures; and establishing and evaluating techniques for database management, laboratory management, and quality assurance/quality control. Characterizing the geologic materials of target areas is a major component in assessing the potential for contamination. The four study areas chosen for the pilot study represent four hydrogeologic groups. For each study area, all available topographic, geologic, and soil survey maps were used to create a database on the Geographic Information System (GIS). -from Editors