Daley Farm of Lewiston plans to more than double the number of cows at its 159-year-old dairy operation in southeast Minnesota, an environmentally sensitive region because of its porous, karst topography that channels contaminants from surface water deep into the ground.

The Minnesota Pollution Control Agency (MPCA) has scheduled a meeting for Oct. 16 at the Lewiston Community Center, 75 Rice St., to explain the dairy’s proposal, together with the environmental review and feedlot permitting processes. The expansion also would require permission from the Department of Natural Resources to add two more livestock watering wells that would draw about 60 million gallons of water a year — raising the dairy’s total to 92 million gallons.

The proposal also requires approval from the Winona County Board, as the expansion dwarfs the county’s feedlot limit of 1,500 “animal units,” an index used to standardize animal waste across such animal species as pigs, cattle and chickens.

Daley Farm of Lewiston already exceeds the county’s feedlot limit because it was grandfathered in when the feedlot limit passed. The dairy now seeks to increase its herd of 1,728 cows and calves to 4,628, pushing its animal units from 2,275 to 5,968.

Kay Qualley, Winona County planning and environmental services director, said staffers are reviewing the proposal, which is incompatible with the county’s comprehensive plan.

“This is still a fact-finding mission,” Qualley said. She said she expects the proposal to draw scrutiny from Trout Unlimited, which has been restoring contaminated streams in the region. And nearby Utica Township will pay close attention to how the expansion would affect water nitrates and wells — “that’s for certain,” she added. There are 29 homes within a mile of the dairy and 13 feedlots within 3 miles.

If approved, Daley Farm of Lewiston would operate the 11th-largest dairy and the 18th-largest feedlot of any type in Minnesota. It would generate about 46 million gallons of manure and wastewater a year.

Shelly DePestel, CFO of Daley Farm of Lewiston, said she expects the proposal to meet some resistance.

“There are people that aren’t very familiar with us, our practices, our manure management, our water usage,” DePestel said. “Yep, there’s going to be some more cows, but it’s not out of our wheelhouse. ... We’re doing everything we can to make sure there are no groundwater issues.”

The MPCA said the project site and several sites where manure from the farm is spread on the land as fertilizer are near or within drinking water management areas. The dairy has agreed to take steps designed to reduce the chance of nitrogen seeping into groundwater.

DePestel operates the dairy with her four brothers. The expansion is needed, she said, to accommodate her three sons, a niece and a nephew who have completed college and want to go into the business.

The dairy has submitted an environmental assessment work sheet prepared by the MPCA, which is open for public comment through 4:30 p.m. Oct. 31. Comments also can be sent by mail to Kim Grosenheider, MPCA, 520 Lafayette Road N., St. Paul, MN 55155-4194.

As of last week, only one comment had been submitted. Roy Beyer, who has an organic farm about 5 miles from the dairy, wrote that the expansion would bring “greater economic prosperity to the area and will allow for expanded markets for local farmers [sic] commodities! Plus I would be willing to aid them in their manure disposal on our land!” he said. “I couldn’t see a better family to expand to the size they are seeking and I wish them well!”