The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has issued a revised general permit for Concentrated Animal Feeding Operations (CAFOs). The permit enhances protection of the public and Michigan’s waters from excessive nutrient pollution while maintaining flexibility allowing large farms to cost-effectively manage animal wastes.

EGLE will delay issuance of Certificates of Coverage for the revised general permit for at least 60 days from its effective issuance date of April 1, due to the COVID-19 pandemic. The general permit regulates roughly 260 of Michigan’s largest livestock operations.

Excessive runoff to waterways from CAFO waste, applied to farm fields as fertilizer, can contribute to public and environmental health concerns such as algal blooms and bacteria contamination. To protect the public and waters, the state is required to update the National Pollutant Discharge Elimination System (NPDES) general permit covering CAFOs every five years.

The updated requirements aim to reduce the impact animal waste has on the health of the Great Lakes, inland lakes, and rivers. The revised general permit was developed with extensive input from the public. EGLE held three stakeholder meetings, three public information sessions, individual meetings with 50 CAFO permit holders and received more than 2,400 comments during a seven-week comment period. The process included input and guidance from the Michigan Department of Agriculture and Rural Development (MDARD).

Many changes were made to the general permit as a result of important and detailed feedback from interested parties and the public. Among the changes:

  • Waste cannot be applied to farm fields in January, February or March when ground is typically frozen and runoff to waterways is more likely.
  • The transportation of waste for composting, treatment, or to out-of-state recipients is allowed during January, February and March as long as the waste is not applied to land during those months.
  • Electronic quarterly reporting of land application of wastes is required, whether the waste is applied to fields, sold, given away or transferred.
  • Waste generators must obtain soil tests from waste recipients before applying it to land to ensure that waste applications to fields are necessary. Allowable levels of phosphorus have been reduced to protect waterways.
  • A permit holder can use either the numerical Bray P1 phosphorous limits, with additional permit requirements that protect water quality, or the Michigan Phosphorous Risk Assessment (MPRA) tool to evaluate fields for manure application.
  • The level of residual solids in storage structures was changed from 12 inches to six inches. The change is consistent with the United States Department of Agriculture’s Natural Resource Conservation Service standards for waste storage structures.
  • The permit allows for evaporation in the calculation of waste storage capacity as allowed for in federal regulation.

CAFOs, where hundreds or thousands of animals are raised in a concentrated area, need an NPDES permit to operate.

Details of the 2020 CAFO general permit are available at EGLE’s MiWaters Site Explorer page.

by Nick Assendelft, Public Information Officer, AssendelftN@Michigan.gov

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