Under the Groundwater Protection Rule, Minnesota Rules 1573.0040 Subparts 2 and 3, the MDA determines the mitigation levels for community water supply wells and their Drinking Water Supply Management Areas (DWSMAs) that have nitrate levels greater than or equal to 5.4 mg/L (or part per million (ppm)), based on monitoring data provided by the Minnesota Department of Health. Under the Rule, wells which have nitrate levels at or above 5.4 mg/L but less than 8 mg/L at any point in the previous ten years will be determined to be at Mitigation Level 1 and wells with nitrate at or above 8 mg/L at any point in the last ten years will be determined to be at Mitigation Level 2, unless the MDA determines there is a point source causing the well to exceed these levels or the MDA delays the determination of a mitigation level decision for good cause.

The process for determining the mitigation level included conducting a review of the quality of the monitoring data, the condition and vulnerability of the well, the hydrogeology and groundwater flow paths for groundwater flowing into the well, and potential point sources such as an agricultural chemical facility, septic system(s), feedlot(s) or a poorly constructed well that may be contributing significantly to nitrate levels in the well.


The MDA has completed this review for the monitoring data received from the Minnesota Department of Health by July 15, 2019 and determined the following:

Map indicating the locations of the Drinking Water Supply Management Areas included under the Groundwater Protection Rule. The list of DWSMAs is included on this site.Mitigation Level 1
Drinking Water Supply Management Areas
  • Becker
  • Glenwood
  • Perham
  • Rice
  • Roscoe
  • Rosemount

Mitigation Level 2
Drinking Water Supply Management Areas

  • Adrian
  • Altura
  • Clear Lake
  • Cold Spring
  • Edgerton
  • Elgin
  • Ellsworth
  • Hastings
  • Lincoln Pipestone Rural Water - Holland
  • Lincoln Pipestone Rural Water - North Holland
  • Lincoln Pipestone Rural Water - Verdi
  • Melrose
  • Rock County Rural Water System
  • Saint Peter
  • Shakopee
  • Utica
  • Verndale

Mitigation Level Decisions Delayed for Good Cause

  • Atwater
  • Balaton
  • Chandler
  • Darfur
  • Goodhue
  • Milaca
  • Moose Lake
  • Perham (for a Level 2 decision)
  • Pine River
  • Plainview
  • Sauk Rapids

In DWSMAs where MDA has delayed the determination of a level decision for good cause, it is because of the need for additional information.