Dozens of people urged state environmental regulators Thursday to deny a large livestock farm’s proposal to expand in Pierce County. The plan would more than triple the number of cows and manure generated by the farm.Ridge Breeze Dairy in the town of Salem is a concentrated animal feeding operation, or CAFO, that runs a roughly 1,700-cow dairy within the Rush River watershed that drains into the Mississippi River. The farm wants to change its existing CAFO permit so it can grow the operation to about 6,500 cows by the end of 2025. The expansion is expected to generate nearly 78 million gallons of manure each year.In a Thursday hearing, residents of the area voiced concerns to the Wisconsin Department of Natural Resources about the proposal’s potential to pollute nearby waterways and groundwater, pointing to the owner’s history of violations.Samantha Bowen said she’s a sixth generation farmer in the town of Union and lives nearby Ridge Breeze Dairy. She said some local streams and private wells in the area already struggle with nitrate contamination, saying that adding millions more gallons of manure to fields won’t improve water quality.“The potential for groundwater problems seems more possible than ever. No one is coming to save us if our water gets contaminated. We are on our own,” Bowen said.She and others urged the DNR to require groundwater monitoring wells and cap the number of animals at the farm’s current amount. Bowen said testing of private wells in Pierce County has shown nitrate levels above the federal health standard of 10 parts per million, including in her own well. A 2022 report on well testing shows 12 percent of wells sampled exceeded that threshold in the towns of Salem, Union, Maiden Rock and others.Nitrate contamination has been linked to blue-baby syndrome, thyroid disease and colon cancer. Around 90 percent of nitrate in groundwater can be traced back to agriculture.