Along the St. Croix River, big ag plans prompt water-quality worries, new restrictions

In the part of Wisconsin that lies just east of the St. Croix River, a growing sense of alarm over pollutants in drinking water has prompted locals to push back against a series of farm proposals.

A hog farm that could raise thousands of pigs at a time, a dairy farm that wants to grow to 4,700 cows, and a biogas digester proposed by a subsidiary of Shell, the oil and gas company, have all drawn fire online or at local town board meetings. Residents worry about what these things could mean for the water percolating through the limestone bedrock just beneath their feet.

"We do have some big challenges," said Kim Dupre, a self-described citizen advocate who leads a group calling for water protections.

The tension comes as monitoring by St. Croix County shows a slow but persistent rise in nitrates in the private wells that many residents use for drinking water. Some 13% of wells exceed the health guidelines for nitrates, up from 10% in 2010, and just 15% deliver water with less than one part per million of nitrate, according to Tim Stieber, the county's resource management administrator.

A nitrogen-based compound, nitrate can be harmful to human health, with extra cautions given for pregnant women and young children. Excess nitrogen can imperil animal life in forests and streams and is one of the main causes of the so-called "dead zone" in the Gulf of Mexico.

There have been other concerns about the large farm proposals, too, from odor to the loss of local control to the economics of commercial farms known as concentrated animal feedlot operations, or CAFOs, in an area dotted with smaller, family-run farms.

Farmers want clean water, too, said Tara Daun, the watershed coordinator for the Wisconsin Farmers Union. Some have joined one of the 43 farmer-led watershed councils in Wisconsin to share conservation practices and protect local waters. The farmers in the Horse Creek Farmer-Led Watershed Council near Osceola, for example, were able to reduce nutrient runoff from their fields last year by some 4,296 pounds of nitrogen and 3,543 pounds of phosphorus, she said.

"We do feel like we are able to make actual strides here," said Daun, speaking at a Sept. 28 water quality conference in Star Prairie, Wis.

Some of the recent battles over clean water include an Iowa company's proposal to create the largest hog farm in northern Wisconsin, with up to 26,000 pigs on a 35-acre site in Trade Lake, Wis. The company's application was rejected in March by the Wisconsin Department of Natural Resources (DNR) after the agency said the applicant didn't have a solid plan for how it would safely spread manure created by the operation. The permit application from Cumberland LLC said it could generate up to 9 million gallons of manure annually, with spreading on local fields or trucked across the river to fields in Minnesota.

The company first proposed its farm in 2019, prompting five towns to pass ordinances meant to protect water and curb other environmental impacts. Lisa Doerr, a Polk County farmer who was among the town officials behind the ordinances, said the towns feel like they're in a wait-and-see mode on Cumberland's plans.

"We have grassroots people battling hand-to-hand trying to keep industrial agriculture out of the St. Croix Valley," she said.

In Emerald, Wis., a large dairy operation has filed a permit with the DNR to expand its operation to some 4,700 cows. The farm, Emerald Dairy, had a large manure spill in 2017 into a nearby waterway; the DNR issued a violation notice and the dairy eventually paid $80,000 in 2019 to settle out of court.

There's already concern in the area about phosphorus levels in the surface waters and nitrate levels in the groundwater, said Dupre.

The University of Wisconsin extension service said levels of phosphorus should be around 16 to 25 parts per million, but fields tested by the DNR near Emerald, Wis., showed phosphorus levels as high as 186 parts per million.

Nitrate levels, meanwhile, were far above the safe drinking water standard of 10 parts per million, with tests of wells near the Emerald Town Hall at 52 parts per million in May of last year.

"That's a rural, residential area of St. Croix County; that's not ag land," Dupre said. Families who live nearby may have the same results in their wells, she said.

A wholly-owned subsidiary of Shell, Nature Energy LLC, has come before towns in St. Croix County in recent years seeking to build an anaerobic digester, a plant that turns manure or food waste into biogas. Local concerns about property values, odor, truck traffic, and the tons of leftover material after biogas is extracted have surfaced at public meetings and citizen petitions. The most recent attempt, in New Richmond, Wis., ended in August when the company withdrew its application for a needed zoning change.

"Automatically you're going to have a huge accumulation" of leftover material, said Stieber. Under plans presented in the village of Roberts, the company would have drawn manure from farms up to 20 miles away. Once the gas was extracted, the leftover material would be spread on local fields as fertilizer. It was the volume of phosphorus-rich manure that troubled Stieber. If too much is applied, rainstorms could wash it into the local streams and, eventually, the St. Croix River.

The Lake St. Croix region of the river is already being monitored for high phosphorus levels, with a long-term plan expected to reach its goal of reducing phosphorus by tens of thousands of pounds annually by 2027.

The proposal in Roberts didn't win public approval. Nature Energy reintroduced the plan in New Richmond, Wis., this summer before it, too, failed to garner enough public support. It's the fourth time such a facility has been proposed in St. Croix County in the past five years.