The “economic impact comment” period has concluded for new agricultural performance standards for farms that apply manure in areas of the state with shallow soils over fragile Silurian bedrock.

The addition to Natural Resources rule 151 (NR 151) sets limits to liquid and solid manure spreading on fields in areas of the state with 2-3 feet, 3-5 feet, and 5-20 feet of soil depth above Silurian bedrock. That includes parts of 15 counties, including Kewaunee, Door, Brown and Outagamie counties.

The goal is to minimize the risk of leaching pathogens through the shallow, fragile bedrock into groundwater.

A study led by Mark Borchardt of the USDA confirmed relationships between depth of soil and the likelihood of contaminated groundwater, especially when manure is applied to farm fields during periods when the water table is recharging in the spring and fall.

Kewaunee County Conservationist Davina Bonness told the county Land and Water Conservation Committee on Tuesday that the DNR is hoping to have a review review of the draft rule, comments and a public hearing in September, with legislative review in December or January.

Injecting liquid manure on a farm field. (Dreamstime stock image)

Bonness has been part of the state NR 151 Technical Advisory Committee that worked on the rules, which are largely based on the efforts of DNR workgroups comprised of Kewaunee County residents from all walks of life who spend more than a year developing the standards.

She urged the committee to take a stand in support of the rules as written.

“I think that our community should really push to make sure that it does not get weaker through public comment, because we’ve seen through Mark’s research that 0-20 feet still has an extremely high chance of contamination risk,” Bonness said.

Supervisor Chuck Wagner suggested that the committee draft a resolution in support of the Silurian bedrock standards in NR 151 in order to send it to the full County Board in September, when the public comment period is expected to be open.

Supervisor Lee Luft volunteered to get started writing the resolution for consideration at the committee’s next meeting, Sept. 12.

Bonness said the DNR took the rare step of reopening NR 151 because of the Kewaunee County work groups.

“We pushed in that committee and I sat in all those meetings, and I really don’t want that to be watered down,” Bonness said. “I know it’s going to impact some businesses, I know it’s going to have a big impact especially up in Door County where they don’t have a lot of soil, but ultimately we have to know we can’t be spreading on these shallow soils like we have been in the past, because of the contamination risk. So I really want us to come together on this one and not let it get watered down.”