Under the Groundwater Protection Rule, a list of nitrogen best management practices (BMPs) and alternative management tools (AMTs) to protect groundwater within the St. Peter Drinking Water Supply Management Area (DWSMA) has been approved by the MDA and published in September 2024.
The list of practices was developed by the MDA in consultation with the Local Advisory Team (LAT). The BMPs will need to be adopted on at least 80% of cropland (excluding soybean acres) within the DWSMA. AMTs can be voluntarily adopted and used to replace BMPs in certain situations. A summary of the information used by the MDA to develop the list is also available.
- Best Management Practices for the St. Peter Drinking Water Supply Management Area (PDF)
- St. Peter DWSMA Groundwater Protection Rule Summary (PDF)
The BMP list identifies practices for coarse and fine textured soils. An interactive map of the St. Peter DWSMA is available to illustrate where coarse soils are present. Producers can use this map to consider which BMPs are applicable to the fields they farm within the DWSMA.
Note that Part 1 of the Groundwater Protection Rule restricts the application of nitrogen fertilizer in the fall and on frozen soils in this DWSMA unless producers are following the exceptions to the rule.
After no less than three growing seasons following the publication of this list, the MDA will conduct an evaluation to determine if the BMPs or AMTs have been adopted in the St. Peter DWSMA. If during this evaluation less than 80% of the cropland acres within the DWSMA have adopted the BMPs or AMTs listed, the DWSMA may be designated a Mitigation Level 3 and the adoption of the BMPs will be required.
St. Peter DWSMA Details
Due to elevated levels of nitrate-nitrogen, the St. Peter DWSMA was listed at a Mitigation Level 2 under the Groundwater Protection Rule. To learn more about the determination process visit Mitigation Level Determination.
- Designated a Mitigation Level 2 on January 15, 2020 using the following criteria
- One or more public wells have exceeded 8 mg/L nitrate within the past 10 years
- No point source of nitrate found to be the cause of the elevated nitrate level
(i.e., ag chemical incidents, animal feedlots, improperly sealed wells, etc.)
- The DWSMA area where the rule applies is approximately 7,029 acres (highly vulnerable)
- Located in Nicollet County
- Nitrate levels in three of the nine primary public wells have tested above 10 mg/L in the past ten years
- The MDA has installed a groundwater monitoring network within the DWSMA.
St. Peter Local Advisory Team
The MDA established a Local Advisory Team (LAT), consisting of local farmers and agronomists, with additional support from local government staff, and the public water supplier.
The primary functions of the LAT are to:
- Advise the MDA on the appropriate nitrogen fertilizer BMPs for the project area.
- Explore opportunities to use Alternative Management Tools (AMTs) in targeted high-risk areas.
- Provide the MDA with guidance on the most effective methods to communicate with the agricultural community in the local project area.
- Support the implementation of the BMPs and AMTs at the local level.
Throughout 2021 to 2024, MDA staff met with the St. Peter LAT reviewing agronomic information and the MDA's analysis of nitrogen loss below cropland within the DWSMA. Below is a list of milestones that were met during this process. The LAT will continue to meet once annually to review new public well nitrate data and discuss ongoing implementation of BMPs and AMTs within the DWSMA.
- Formed a local advisory team and is actively meeting.
- Interviewed local ag retailers and farmers to gather information on the current nitrogen fertilizer management practices within the DWSMA.
- Mapped the boundaries of cropland within this DWSMA.
- Completed computer modeling of nitrate loss below the crop rooting zone within this DWSMA.
- In consultation with the LAT, a draft list of BMPs and AMTs that are practicable and appropriate for protecting groundwater within this DWSMA was developed. After final review the list was posted in September 2024.
