VERNON COUNTY - A manure spill at the Wild Rose Dairy in Vernon County last week is suspected of killing 1,300 fish in Otter Creek, according to the Wisconsin DNR.

The DNR confirmed that brook and brown trout in the stream were killed. Trout need parts per million of dissolvable oxygen present in the water to survive, according to Dave Vetrano, a retired DNR fisheries manager. Quantities of manure in the water use available oxygen to decompose. When dissolvable oxygen levels drop, fish die.

The Wild Rose Dairy manure spill in rural Webster Township is currently under investigation. The details of the event are being withheld pending the completion of the investigatory process, the DNR reported.

“Wisconsin Department of Natural Resources staff continue to monitor the stream quality of Otter Creek, located north of the Village of LaFarge,” according to a DNR statement released on Friday, Oct. 6. “Department fisheries biologists report a kill of more than 1,300 fish, including brook and brown trout, in the headwaters of the stream. The rest of the stream, known for its large fish population, does not currently appear to be impacted by the runoff.  Otter Creek is a tributary of the Kickapoo River, but fish in the Kickapoo have not been affected. The spill was reported to the DNR earlier this week and the source of the spill has been controlled.”

Vernon County Conservationist Benjamin Wojahn acknowledged that the Vernon County Land & Water Conservation Department has been notified by the DNR of the spill, but stated he is not at liberty to comment on the situation.

“Our department has been asked to let the DNR take the lead in communication around this incident,” Wojahn said. “They are the agency that is responsible for conducting the investigation.”

Tom Lukens, the Board Chairperson of Valley Stewardship Network, reported that he understands the spill occurred during the course of a pumping operation involving a manure holding area. The spill likely occurred as the result of a connection failure in the pumping equipment, according to Lukens.

Otter Creek, located in central Vernon County, flows in a southeasterly direction for 4.5 miles before reaching the Kickapoo River at LaFarge. The stream drains forested hillsides with agricultural activity in both the valleys and on the ridge tops. Otter Creek is a Class III trout stream for its entire length.

Wild Rose Dairy

Wild Rose Dairy, an 800-cow, permitted, confined animal feeding operation (CAFO) is situated on Buckeye Ridge on land that drains down into the Otter Creek watershed. It’s location is 3.5 miles northwest of the Village of LaFarge.

The dairy contains manure from the operation in holding areas on the property, and distributes the manure onto cropland on the farm through large hoses.

Vernon County currently has a total of four permitted dairy CAFO operations, of which Wild Rose Dairy is one. Crawford County has one permitted swine CAFO; Richland County has two dairy and two swine CAFOs; and Monroe County has three dairy CAFOs.

VSN’s Lukens said that the spill occurred in a section of the Wild Rose Dairy property that drains down into the headwaters of Otter Creek. The manure travelling down a dry wash along the side of Kirking Road, to its intersection with Vernon County Highway D. The creek is fed by springs from the impacted area, and water only begins to run on the surface on the other side of D.

Sensitive karst geology

While obviously a tragedy for the farmers, Arthur Thelen and David Abt, who own the operation, the incident is also a tragedy for the  community in the area. The impacts to surface and ground water quality are yet to be determined.

“We have taken a sample of water from the creek, and are sending it off to be tested,” Lukens shared. “We also did macroinvertebrate sampling at a location on the creek last October, and are considering pulling another sample soon.”

David and Barb Sarnowski live along Otter Creek, and are water action volunteers with Valley Stewardship Network. They have been involved in water quality sampling of Otter Creek for four years.

Barb Sarnowski reported that she did not observe any noticeable commotion in the area of the spill, and had not seen any evidence of manure in the water visible to the naked eye.

“In my four years of monitoring water quality in Otter Creek, we had been seeing steady improvements in the water quality every year, which speak to the conservation practices being employed by area farmers,” Sarnowski said. “After this manure spill, I don’t know what to expect.”

According to Sarnowski, no well water advisories have been issued to local landowners.

Western Wisconsin

Large areas of the state have an underlying Karst geology. Counties in the state where virtually the entire area is karstic include Crawford, Grant, Green, Iowa, Lafayette, LaCrosse, Pierce, Richland and Vernon.

Karst is a landscape formed from the dissolution of soluble rocks such as limestone, dolomite and gypsum. It is characterized by underground drainage systems with sinkholes and caves.

Because of its highly fractured nature, this type of topography can make a region more susceptible to groundwater contamination.

Karst geology and direct conduits to groundwater, such as springs, seepages, sinkholes, caves, fractures, and stream sinks, have been mapped extensively in some parts of the state, and not at all in others.

One of the reasons that the Natural Resources Board’s Groundwater Collaboration Workgroup has not moved to include counties in Southwest Wisconsin in their ‘sensitive areas’ designation is the lack of data and mapping currently available.

Clean Wisconsin, who together with Midwest Environmental Advocates, filed a petition for emergency action on October 22, 2014, detailing the need for the U.S. Environmental Protection Agency to exercise its emergency powers under the Safe Drinking Water Act and other federal pollution cleanup laws, included the following language in a statement made in advance of the NRB’s September 2017 meeting:

“We hope these rule changes will start to show results for Kewaunee County, but we know this is only the starting point,” said Scott Laeser, Water Quality Specialist with Clean Wisconsin. “Other parts of the state are still vulnerable to groundwater contamination. For now, the state and the agricultural community must use existing tools to reduce the risk of groundwater contamination in Southwest Wisconsin, but the state must prevent another drinking water crisis like the one facing residents in Northeast Wisconsin from happening elsewhere in the state.”