Minnesota residents have until April 9 to file comments on the Minnesota Department of Agriculture’s request to designate three neonicotinoid insecticides as “surface water pesticides of concern.”
MDA decided to seek the change after reviewing data and impacts of their use on the environment and pollinators. The 60-day comment period on the notice ends April 9.
Details of the department’s Pesticide Management Plan (PMP) are available online,
“Surface water pesticide of concern,” as it is used in the PMP, means the detection of a pesticide in surface water at concentrations of concern relative to a water quality. The pesticides found to be of concern in the state are clothianidin, imidacloprid and thiamethoxam.
In 2018, the U.S. Environmental Protection Agency lowered the aquatic life benchmarks for clothianidin from 1,100 nanogram per liter to 50 nanogram per liter; imidacloprid from 1,050 nanogram per liter to 10 nanogram per liter; and thiamethoxam from 17,500 nanogram per liter to 740 nanogram per liter.
MDA monitoring results from 2010 through 2018 show that clothianidin, imidacloprid and thiamethoxam detections in several state rivers and streams approached or exceeded EPA’s updated aquatic life benchmarks for these pesticides. Clothianidin detections alone exceeded the updated benchmark 83 times in Minnesota rivers and streams since 2011; imidacloprid detections, up since 2010; and thiamethoxam detections, exceeded the updates twice since 2010.
With its proposal, MDA has included a proposal to develop and promote water quality best management practices for the three neonicotinoid insecticides. MDA previously developed BMPs for these neonicotinoid compounds to protect pollinators in its summer 2016 report, “Review of Neonicotinoid Use, Registration and Insect Pollinator Impacts in Minnesota.” MDA expects these BMPs would also protect surface water.
MDA also is requesting that the Minnesota Pollution Control Agency develop state-specific water standards for imidacloprid, thiamethoxam and clothianidin. Until development of Minnesota-specific standards has taken place, MDA will use EPA’s benchmarks as guidance.
Additional information related to clothianidin, imidacloprid, and thiamethoxam in this notice and on MDA voluntary pesticide BMPs is available online.
Clothianidin, imidacloprid, and thiamethoxam are used to control a number of insect pests in agricultural production systems and turf and ornamental settings throughout Minnesota. Notable application methods include seed treatments, granular, spray and drench applications.