Groundwater Protection Rule now official

The final Groundwater Protection Rule was published Monday, June 24th in the State Register, finalizing a rule regulating nitrogen application in vulnerable groundwater areas. While the rule is now effective, farmers will have some time before regulatory action will occur.

For a refresher on the Groundwater Protection Rule: The rule contains two parts. Farmers may be subject to one part of the rule, both, or none at all, depending on your geographic location:

  • Part 1: Fall application of nitrogen is restricted if you farm is located in 1 ) an vulnerable groundwater area (click here for a map) where at least 50 percent or more of a quarter section is designated as vulnerable or 2) protection areas around a public well, known as a drinking water supply management areas (DWSMA), with nitrate-nitrogen at least 5.4 mg/L in the previous ten years. .
  • Part 2: Farmers located in a DWSMA with elevated nitrate levels will be subject to a sliding scale of voluntary and regulatory actions based on the concentration of nitrate in the well and the use of the best management practices.

*For a more detailed description on either part of the rule and updated maps, click here.

While the rule is now official, Minnesota’s ag community will have time to adjust and comply with the rule.

Part 1 will not be effective until Jan. 1, 2020, meaning restrictions on fall application will begin in fall 2020.. In Part 2 of the rule, no regulatory action will occur until after at least three growing seasons once a DWSMA is determined to meet the criteria for level 2.

The timeline of the Groundwater Protection Rule

The proposed Groundwater Protection Rule, previously referred to as the Nitrogen Fertilizer Rule, is based on the Minnesota Nitrogen Fertilizer Management Plan, which outlines the state’s strategy for preventing contamination and responding to elevated nitrate from fertilizer in groundwater. This plan first originated in 1990. For a complete historical timeline, click here.

Formal rulemaking for the Groundwater Protection Rule began spring 2018 in a call for public comments and testimony was provided during Office of Administrative Hearings public hearings. The Minnesota Corn Growers Association, along with a number of the state’s corn farmers, provided input during this time.

Following the comment period, the Office of Administrative Hearings ruled the Groundwater Protection Rule may move forward, but also identified six defects that needed to be addressed.

In November, the chief administrative law judge determined the defects had been corrected, but the proposed rule could not be finally adopted until after the 2019 legislative session as a result of resolutions passed by the agriculture committees in the Minnesota House of Representatives and Minnesota Senate during the 2018 legislative session.

Following the 2019 legislative session, Commissioner of Agriculture Thom Petersen signed the rule, setting in motion a number of procedural steps that ended with Gov. Tim Walz’ signature and the final rule being published in the Minnesota State Register

To find out if you are impacted by either part of the Groundwater Fertilizer Rule, visit

If you would like to learn more about the history of the Groundwater Protection Rule and MCGA’s involvement throughout, visit

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