Five pesticides have been designated as "surface water pesticides of concern" by the Commissioner of Agriculture.
- Clothianidin (neonicotinoid insecticide) - Designated in 2020
- Imidacloprid (neonicotinoid insecticide) - Designated in 2020
- Chlorpyrifos (insecticide) - Designated in 2012
- Acetochlor (herbicide) - Designated in 2003
- Atrazine (herbicide) - Designated in 2003
“Surface water pesticide of concern” is an official designation assigned by the commissioner to a pesticide that has been detected in surface water at concentrations of concern relative to a water quality “reference value” not due to misuse or unusual or unique circumstances, but likely to be the result of normal use of a product or practice. Designation as a “surface water pesticide of concern" initiates development and promotion of chemical specific best management practices (BMPs) and increased water quality analysis. The designation as a "surface water pesticide of concern" considers both the detections of the pesticide in Minnesota surface waters and the concentration relative to water quality standards and/or reference values.
Decision to Designate Clothianidin, and Imidacloprid as “Surface Water Pesticides of Concern” in Minnesota.
A Notice of Final Decision to Designate Clothianidin and Imidacloprid as "Surface Water Pesticides of Concern" was published in the Minnesota State Register on December 7th, 2020 (45 SR 557).
The decision to designate clothianidin and imidacloprid as “surface water pesticides of concern” in Minnesota was based on guidelines outlined in the Pesticide Management Plan (PMP).
- In 2017, the Environmental Protection Agency (EPA) lowered the Aquatic Life Benchmark (ALB) for clothianidin, imidacloprid, and thiamethoxam.
- The MDA monitoring results from 2010 through 2019 indicate clothianidin and imidacloprid detections in several state rivers and streams approached or exceeded the EPA’s updated ALBs for these pesticides.
- On February 10, 2020, a notice was published in the Minnesota State Register of the Commissioner’s preliminary decision to designate three neonicotinoid insecticides, clothianidin, imidacloprid, and thiamethoxam, as “surface water pesticides of concern” (State Register Volume 44, Number 33). A total of 16 public comments were received and reviewed by the Commissioner. The public comments and the MDA's response to relevant comments are listed under the reference documents below.
- After further consideration of the surface water monitoring data, public comments, and guidance in the PMP, the Commissioner has decided to designate clothianidin and imidacloprid as “surface water pesticides of concern.” The Commissioner determined that thiamethoxam does not warrant designation at this time.
Reference documents:
- Proposed Designation of Imidacloprid, Clothianidin, and Thiamethoxam as "Surface Water Pesticides of Concern" Public Comments
- Proposed Designation of Imidacloprid, Clothianidin, and Thiamethoxam as “Surface Water Pesticides of Concern” Response to Public Comments
- Summary of MDA Imidacloprid, Clothianidin, and Thiamethoxam Water Quality Data Collected from Rivers and Streams
