Minnesota State Wire

The Minnesota Department of Agriculture (MDA) has released an updated map to assist farmers in adhering to the Groundwater Protection Rule. This rule limits the fall application of nitrogen fertilizer in areas susceptible to groundwater contamination and outlines measures to reduce contamination severity where nitrate levels are already high in public water supply wells.

Changes have been made to the Fall Nitrogen Fertilizer Application Restrictions Map, now accessible on the MDA website. Notably, the Ellsworth municipal Drinking Water Supply Management Area (DWSMA) has been removed from the map due to a change in the community's water source. More details on fall application restrictions and exceptions can be found on the MDA’s website.

While no new municipal DWSMAs showed elevated nitrate levels, two non-municipal wells were identified with elevated nitrate based on recent data from the Minnesota Department of Health. The Brookhaven Development and Mobile Manor DWSMAs, both located in Scott County, will be added as Mitigation Level 2 DWSMAs under the Groundwater Protection Rule. Consequently, the MDA will establish a local advisory group to recommend farming practices aimed at reducing nitrate levels in groundwater. Additional information is available on the MDA’s Mitigation Level Determination page.

The restriction on fall nitrogen fertilizer application for these areas will commence on September 1, 2025. Farmers are advised to review the updated map before fall 2025 to determine if their fields are affected by these restrictions.

For further information on the Groundwater Protection Rule, visit www.mda.state.mn.us/nfr.