Update: The comment period has been extended to Sept. 3.
As part of efforts to reduce nitrate pollution statewide, the Minnesota Pollution Control Agency (MPCA) today released proposed changes to two permits that regulate the state’s largest animal feedlots. These permits regulate the discharge of pollutants from livestock production areas and restrict the volume of pollutants entering state waters via manure land application. Proposed changes would have the greatest benefit in regions of Minnesota where nitrate can move easily through the soil and into groundwater.
MPCA monitoring shows elevated levels of nitrate in Minnesota lakes, rivers, and streams in some areas of the state. Manure contains nitrogen, a valuable fertilizer. When it’s applied to land, some nitrogen naturally converts to nitrate, which is water-soluble. Nitrate is toxic to fish and other aquatic life. In drinking water, nitrate can be harmful to human health, especially babies.
The current federal National Pollutant Discharge Elimination System (NPDES) general permit lasts five years and expires Jan. 31, 2026. The current State Disposal System (SDS) general permit lasts 10 years and expires May 31, 2025. These permits are required for large facilities, which are generally 1,000 or more animal units. About 1,000 of the 17,000 registered livestock feedlots in Minnesota operate under these permits, with the majority located in the southern half of the state.
With the proposed permits, farmers would have the option to apply manure in the spring or plant living cover on the landscape for manure applied in the fall. The MPCA focused on cover crops because they offer the greatest potential for nitrate reduction in the state’s vulnerable areas, such as those with karst-susceptible bedrock, coarse-textured soils, shallow bedrock, and highly vulnerable drinking water supply management areas. A map of these vulnerable areas can be found on the MPCA's NPDES and SDS feedlot permits page.
Best practices for all manure applications will include incorporating it into the soil when it is applied in a floodplain. Farmers will also need to visually inspect the land during and after application to ensure manure is not leaving the field and to re-inspect the fields if there is rainfall soon after manure is surface applied without incorporation. If the inspections reveal a discharge of manure, it must be reported to the Minnesota Duty Officer. Farmers who receive manure from permitted feedlots would be subject to the requirements of the manure generator’s permit.
Comment period, public meetings
To create ample opportunity for people to ask questions and fully understand these proposed permits, the MPCA will host public meetings around the state. More information and updates will be posted, when available, on the MPCA’s events and meetings web page. They are scheduled at the following dates and locations:
- Monday, July 15, 6 p.m. at Paynesville High School, 795 Business 23 W.
- Monday, July 22, 6 p.m. at Fairmont Knights of Columbus, 920 E. 10th St.
- Wednesday, July 24, 6 p.m. at Chatfield Center for the Arts, 405 Main St.
The MPCA will conduct a 45-day public notice period for the proposed NPDES and SDS permits at the same time. Submit comments via the MPCA public comment webpage from June 24 to Aug. 9. Comments also can be submitted by U.S. mail: Minnesota Pollution Control Agency c/o George Schwint, 12 Civic Center Plaza, Ste. 2165, Mankato, MN 56001.