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 Bureau of Laboratory Services (BLS) analyzes samples for nitrate and more than 100 pesticide compounds using modern analytical methods.
Monitoring Programs
Targeted Sampling Program: Tests groundwater from private wells in agricultural areas around the state to determine if pesticides are present and at what level. Areas with an elevated risk for impact by agricultural chemicals are sampled annually. Samples are collected and analyzed by DATCP's lab. Results are shared with the well owners and local county conservation departments, and they are used to evaluate new policy development. Annual summary reports are posted online.
Field-Edge Monitoring Program: This program analyzes groundwater samples from monitoring wells installed within or near agriculture fields to evaluate whether agricultural practices are affecting groundwater quality. DATCP collaborates with growers around the state to install and maintain a network of groundwater monitoring wells. Groundwater collection occurs multiple times a year over several years to evaluate pesticide concentrations and potential trends. Observations and results help shape future policy and standards development.
Surface Water Sampling Program: Represents a collaboration with the Wisconsin Department of Natural Resources (DNR) stream sampling programs. This program provides pesticide analyses on select stream samples collected by DNR. Pesticides are analyzed by DATCP Bureau of Laboratory Services on samples from streams typically located within agricultural or urban areas where pesticides are used. Data is used to evaluate impacts to surface water quality resulting from agricultural or urban runoff and groundwater discharge.
Exceedance Well Sampling Program: Tests groundwater from private wells around the state where a state established groundwater quality standard for a pesticide has been exceeded. Testing allows for long-term monitoring to evaluate the effectiveness of measures taken to protect groundwater over time.
Statewide Survey: A randomized sampling of approximately 400 rural drinking water wells for nitrogen and pesticides. The survey is designed to provide a statistical snapshot of water quality at the time of sampling to measure the occurrence of pesticides and nitrate, and to evaluate changes in water quality over time. The survey is performed every 5 to 10 years. Five statewide surveys have been completed, with the most recent in 2016. Plans are underway to perform the next survey in 2023.
Emerging Issues: This program seeks to identify new pesticide issues that pose a threat of becoming larger concerns for the agency. Pesticides that pose emerging concerns for groundwater contamination include neonicotinoid insecticides like imidaclopid, clothianidin and thiamethoxam, and the herbicide isoxaflutole.
DATCP-funded Groundwater Research
DATCP is a member of the state Groundwater Coordinating Council (GCC). The following member agencies provide funding for groundwater research of importance to Wisconsin:
- DATCP
- DNR
- Department of Transportation (DOT)
- Department of Safety and Professional Services (DSPS)
- University of Wisconsin (UW)
DATCP's role is to provide funding for pesticide and fertilizer-related groundwater research. UW coordinates these efforts through the Wisconsin Groundwater Research and Monitoring Program (WGRMP). Reports for past DATCP-funded research projects can be found in the WGRMP repository.
Completed reports include:
Titles of ongoing projects funded by DATCP include:
- On-farm Research and Local Partnership to Reduce Nitrate Loading From Agriculture in Pepin County. Report anticipated February 2025.
- Neonicotinoid Groundwater Leaching Potential from Potato and Management Impacts at Field Scale. Report anticipated September 2026.
- Understanding the quality and rate of recharge on uncultivated landscapes under natural and enhanced conditions. Report anticipated September 2026.
- Advanced statistical models for large datasets of pesticide and emerging contaminants in groundwater. Report anticipated September 2026.