Nitrate is one of the most common contaminants in Minnesota's groundwater. The majority of Minnesota households have access to safe drinking water supplies. However, in areas vulnerable to groundwater contamination, some public and private wells have nitrate levels that exceed the health risk limit for nitrate. While elevated levels of nitrate in groundwater can result from several factors, a major contributor in rural Minnesota is nitrogen fertilizer that leaches past the crop root zone.
Our agency is responsible for nitrogen fertilizer use and management under the Groundwater Protection Act. To meet this need the MDA, in cooperation with a multi-stakeholder Advisory Committee and a public review process, developed a management plan.
The Minnesota Nitrogen Fertilizer Management Plan (NFMP) has recently been addended to reflect the new Groundwater Protection Rule. The NFMP is the state's blueprint for preventing or minimizing impacts of nitrogen fertilizer on groundwater.
The primary goal of the Nitrogen Fertilizer Management Plan is to involve the agricultural community in problem solving at the local level to address localized concerns about unsafe levels of nitrate in groundwater.
After revising the NFMP in 2015, the MDA began developing a rule to support the proposed regulatory actions in it. This was a lengthy process with multiple formal and informal comment periods and hearings in front of an Administrative Law Judge. The outcome is a new Groundwater Protection Rule which took effect on June 28, 2019. During this process numerous changes were made in the proposed rule. Some of these changes will also change the approach in the NFMP. The changes included are summarized in the NFMP addendum (PDF).
The MDA developed the original Nitrogen Fertilizer Management Plan in 1990. The Plan went through a revision process from 2010 to 2014. The revised Plan includes new scientific information about groundwater protection and is better aligned with current water resource programs and activities.
The MDA received 32 formal responses. The MDA compiled all written and verbal comments into the document listed below.
(The PDF portfolio opens differently in different browsers. You may not be able to view it in the Adobe Acrobat preview. After clicking the link below, if you receive the following message "For the best experience, open this PDF portfolio in Acrobat X or Adobe Reader X, or later." you will need to first download the file to open it. If you have questions, or challenges please contact Jen Schaust at Jen.Schaust@state.mn.us.)
- Public Comment on the August 2013 draft Nitrogen Fertilizer Management Plan (PDF Portfolio: 41.6 MB / 262 pages (37 documents))
The MDA has carefully reviewed all public comments and developed the following two response documents:
- Response to Public Comments on draft Nitrogen Fertilizer Management Plan (PDF)
- Response to Individual Comments on the draft Nitrogen Fertilizer Management Plan (PDF)
The revised NFMP was finalized in March 2015.
References on Nitrate in Groundwater
There is an extensive body of research documenting fertilizer as source of nitrate in groundwater. Nitrate from nitrogen fertilizer can leach below the root zone and migrate to groundwater. View a list of articles and reports from work done in Nebraska, work done by the United States Geologic Survey and studies from Minnesota. A list of additional references found in subscription journals is also included.