Thursday, January 20, 2011

Minnesota General NPDES Permit For Pesticide Application

The Minnesota Pollution Control Agency (MPCA) has released a proposed general NPDES permit to cover certain types of applications of pesticides. The need for NPDES permit coverage is in response to a 2009 ruling by the 6th Circuit Court of Appeals that NPDES permits were required for all biological and chemical pesticide applications that leave a residue in water including applications are made in or over, including near, waters of the United States.

Unlike the single permit proposed by EPA on June 4, 2010, MPCA has prepared four separate General Pesticide Permits to address different use patterns - Mosquito and Other Flying Insect Pest Control (MNG870000), Forest Canopy Pest Control (MNG873000), Aquatic Nuisance Animal Pest Control (MNG874000), and Vegetative Pests and Algae Control (MNG876000).

Only entities that exceed a threshold listed in each permit are required to submit an application for permit coverage. Permittees that are required to submit an application must do so within six months after permit issuance. Those applicators that do not exceed the threshold will need to comply with the basic permit requirements, but are not required to submit an application.

The permits require that all permittees minimize their discharges to waters of the state. This includes using the lowest effective amount of pesticide and optimal frequency of application, preventing leaks and spills, calibrating equipment, and monitoring to record the amount of pesticides used and the area where they are applied to determine when/if the threshold will be exceeded. Visual monitoring is also required during pesticide application to identify adverse effects to non-target organisms. If there are adverse effects from pesticide application, the permittee is required to contact the Duty Officer and take corrective actions to minimize the effects. Permittees must also implement Integrated Pest Management (IPM) and develop a Pesticide Discharge Management Plan (PDMP).

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