Surface and Groundwater Monitoring

The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) performs routine monitoring for pesticides and nitrate to evaluate the occurrence of agrichemicals in surface water and groundwater. DATCP’s lab analyzes samples for nitrate and over 100 pesticide compounds.

Monitoring Programs

Targeted Sampling Program – Tests groundwater from private wells in specific agricultural areas around the state to determine if pesticides are present and at what level. DATCP uses a targeted approach annually to select private drinking water wells considered at an elevated risk to be affected by agricultural chemicals.

Field Edge Monitoring Program – Chemically analyzes groundwater samples collected from monitoring wells that are constructed next to fields where agricultural chemicals and fertilizer are applied. A​n evaluation is completed to determine if agricultural practices are affecting groundwater quality. DATCP collaborates with growers around the state to install and maintain a network of monitoring wells used in this program. Testing the groundwater collected from these wells helps identify agrichemicals that reach groundwater near the well, presumably from agricultural use practices nearby.

Surface Water Sampling Program – Performed in collaboration with the Wisconsin Department of Natural Resources (DNR) stream sampling programs. Several streams (a small percentage of all streams monitored by DNR) are selected for pesticide analysis. Streams within agricultural areas are targeted to evaluate the impacts to surface water resulting from agricultural runoff and groundwater discharge.

Exceedance Well Sampling Program – Tests groundwater from private wells around the state where groundwater exceeds thresholds for quality standards as set by the state. Testing determines if the measures implemented are effective in protecting groundwater quality over time.

Statewide Survey – Consists of sampling approximately 400 rural drinking water wells for nitrogen and pesticides. The survey is statistically designed to provide a snapshot of water quality at the time of sampling and measure changes in water quality over time. The survey is performed every 5-10 years. Currently, five statewide surveys have been conducted, the most recent in 2016.​​​​​

Surface Water Monitoring​

DATCP provides routine monitoring for pesticides and nitrates at select surface water locations. This work is completed in collaboration with the Wisconsin Department of Natural Resources (DNR). The data is used to inform other pesticide regulatory programs, DNR, U.S. Environmental Protection Agency, and other Groundwater Coordinating Council (GCC) member agencies of pesticide and nitrate issues occurring in surface waters statewide.