Board to Vote on Wisconsin DNR Pesticide Regulation Crafting
By Danielle Kaeding
October 28, 2026
Updated October 28, 2026 at 8:10 am
Farmer Rick Clifton drives a spray tractor across one of his fields, applying herbicide to cover crops that occupied the ground during fall and winter in Orient, Ohio, on April 5, 2021. Clifton grows cereal rye and rapeseed to prevent erosion and make the ground healthier for his corn, soybean, and wheat cash crops.
John Flesher/AP Photo
The policy-setting board for the Wisconsin Department of Natural Resources (DNR) is set to vote Wednesday on whether the agency can begin crafting groundwater standards for roughly two dozen pesticides.
The DNR is proposing to set health-based standards for 22 pesticides that have already been detected or are highly likely to be found in groundwater, according to Carla Romano, the agency’s groundwater section manager.
“The idea is to protect public health,” Romano said.
Around two-thirds of Wisconsin residents get their drinking water from groundwater, and roughly one-third rely on private wells that draw directly from groundwater. A 2023 survey conducted by the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) estimated that 43 percent of wells in Wisconsin contained at least one pesticide.
In 2019 and 2021, the DNR attempted to regulate 10 substances on the current list, including glyphosate, which has drawn fierce debate over whether it causes cancer. Romano said agency staff believe previous efforts to set standards failed due to the inclusion of other contaminants, including PFAS.
The state has also encountered challenges with setting standards due to either a lack of research on pesticides or a lack of federal standards. Sara Walling, water and agriculture program director for Clean Wisconsin, noted federal drinking water standards don’t exist for several neonicotinoid insecticides proposed for regulation, including imidacloprid, clothianidin, and thiamethoxam. These insecticides are widely used to control pests on crops, gardens, and pet collars. They’re known to threaten the health of pollinators, including bees.
“I’m confident that there’s enough data for the Department of Health Services to be able to identify those health-based maximum contaminant levels,” Walling said.
The DNR has requested that the Department of Health Services develop those health-based standards, which state health officials intend to provide in November. Some farm groups want to see the Natural Resources Board postpone any decision until those thresholds are developed, according to Jason Mugnaini, executive director of government relations for the Wisconsin Farm Bureau Federation.
“It’s kind of something that is making people anxious at the moment because it could potentially impact farmers’ bottom lines down the road,” Mugnaini said.
He said restrictions on pesticides could cause farmers to use alternative practices that may be more damaging to the environment or force them to