Herbicide Best Management Practices to Protect Water Quality

The MDA monitors Minnesota surface water and groundwater for agricultural pesticides that leach or runoff. Monitoring results over several years have shown that the herbicides acetochlor, alachlor, atrazine, metolachlor and metribuzin – or their breakdown products – are frequently detected in Minnesota groundwater or surface water. Water resource monitoring data collected by the MDA supporting these determinations can be reviewed in the MDA Water Quality Monitoring Reports.

Based on these water quality monitoring results, the MDA is required to develop voluntary pesticide-specific Best Management Practices (BMPs) to prevent or minimize pollution, to the extent practicable, for pesticides that are commonly detected in groundwater (Minn. Stat. 103H.275, subd. 1.(a)), and may, under Minn. Stat. Chapter 18B, elect to develop water quality BMPs for other pesticides of concern.

The MDA developed a set of core BMPs that apply to the use of all agricultural herbicides, and separate pesticide-specific BMPs for acetochlor, atrazine, metolachlor and metribuzin. The core BMPs include additional information and resources helpful to farmers. Core BMPs are considered the foundation for the herbicide-specific BMPs and are promoted statewide for all agricultural herbicide use to protect water resources. The BMPs for acetochlor were first published in 2004, updated in 2008 and revised in 2010 and 2018.

Adopted Water Quality BMPs

• Water Quality Best Management Practices for All Agricultural Herbicides (PDF)
• Water Quality Best Management Practices for Atrazine (PDF)
• Water Quality Best Management Practices for Acetochlor (PDF)
• Acetochlor Best Management Practices for Water Quality Protection-Infographics (PDF)
• Water Quality Best Management Practices for Metolachlor (PDF)
• Water Quality Best Management Practices for Metribuzin (PDF)

Additional Resources

BMP Posters

Two posters feature the MDA Water Quality BMPs for Agricultural Herbicides:

• Protect Surface Water Poster (2007)
  Illustrates the use of filter strips, a BMP for protecting water from runoff from field applied atrazine, acetochlor and other herbicides.

  • Protect Surface Water Poster - Letter size (PDF)

• Required Atrazine Setbacks Poster
  Illustrates mandatory atrazine application setbacks included on the label of any herbicide product containing atrazine. Unlike BMPs, which are voluntary practices, the application setback on this poster are label requirements.

  • Required Atrazine Setbacks Poster - Letter size (PDF) 

  • Required Atrazine Setbacks Poster - Tabloid size (PDF)

Report

The original report concerning pesticides in drinking water:

Minnesota Department of Health. July 15, 2010. Drinking Water Contaminants of Emerging Concern Program, A Minnesota Clean Water Fund Initiative, 2010-2011 Biennium, Interim Report.