MDA issues updated Groundwater Protection Rule map
In January, the Minnesota Department of Agriculture (MDA) released an updated map containing areas of Minnesota subject to fall nitrogen fertilizer application restrictions in 2024 under the Groundwater Protection Rule.
Three drinking water supply management areas (DWSMAs) were removed from the map, and none were added, according to MDA. Two of the removed DWSMAs were found to have non-agricultural sources of nitrate, and the third was removed after further sampling data indicated nitrate levels were below the threshold for inclusion.
Effective since 2019, the Groundwater Protection Rule restricts fall application of nitrogen fertilizer in areas vulnerable to groundwater contamination (part one) with the goal of minimizing potential sources of nitrate in groundwater. It also outlines steps to reduce the severity of contamination in areas where nitrate is already elevated in public water supply wells (part two).
Formal rulemaking for the Groundwater Protection Rule began spring 2018 in a call for public comments, and testimony was provided during public hearings held by the state Office of Administrative Hearings. The Minnesota Corn Growers Association (MCGA), along with a handful of the state’s corn farmers, provided input during this time.
The restriction of nitrogen fertilizer application in vulnerable groundwater areas and affected DWSMAs begins September 1, 2024. MDA encourages farmers to check the new map prior to fall 2024 to determine if their fields are subject to the restrictions.
MCGA continues to highlight how corn farmers share the goal of protecting drinking water in Minnesota and that farmers are a part of solution in addressing water quality challenges. Minnesota farmers have been making voluntary efforts to protect groundwater by employing best practices that allow them to grow more corn by using nitrogen more efficiently. And, through the Minnesota corn check-off, Minnesota corn farmers have invested more than $15 million into university-led and on-farm research, education to improve nutrient use efficiency, and soil health practices to reduce the impact of nitrogen on groundwater.
Learn more about how Minnesota corn farmers are proactively protecting water quality here. For a historical timeline and details on MCGA’s involvement in the development of the Groundwater Protection Rule, click here.
