The application of nitrogen fertilizer in the fall or on frozen soils will be restricted to quarter-sections of land where 50 percent or more of the quarter-section is in an area with vulnerable groundwater and in DWSMAs that have nitrate-nitrogen concentrations at or in excess of 5.4 mg/L nitrate-nitrogen. An area with vulnerable groundwater is an area where nitrate can move easily through soil and into groundwater, contaminating drinking water sources. Vulnerable areas for Part 1 of the rule are defined as:

View the interactive Vulnerable Groundwater Area Map To access all of the mapping layers select the layer list icon in the upper left corner of the map page. To view a layer, check the box to the left of the layer title.

The DWSMAs on the map are from a preliminary list in March, 2018. It has not been updated. The MDA is currently working with the Minnesota Department of Health to revise the list.

The map shapefiles can be downloaded from the Minnesota Geospatial Commons.

A map of the state of Minnesota illustrating the areas where the statewide fall restriction and Drinking Water Supply Management areas are located.r