By: Paul J. Sniadecki, MLSA Board Director
EGLE (formerly DEQ) regulators want to revise how the environmental risk from spreading livestock waste on farms is evaluated as part of a new “draft” general permit for industrial scale agriculture businesses known as Concentrated Animal Feeding Operations or CAFOs that would, among other things, prohibit the application of manure on farm fields during three winter months.
Public comment was open through Dec. 18, 2019 on the proposed updates to the state’s general National Pollutant Discharge Elimination System (NPDES) permit program for CAFOs. The last revisions to the NDPES Permit Program occurred in 2015 and applied to over 250 NDPES permitted farms in Michigan. Michigan has delegated authority from the U.S. Environmental Protection Agency (EPA) to issue NPDES permits and the state says its proposed changes were developed with EPA input.
EGLE released its planned revisions in late October 2019. Farm industry advocates blasted the proposed changes, while environmental advocates say the new requirements are important measures that will protect water quality and improve public access to permit records.
In Michigan, waste from confined animal farms is usually stored in large lagoons and spread on fields as crop fertilizer. While that can help increase crop yield, it can also degrade water quality when nutrients like phosphorus and nitrogen run off into lakes, streams, and rivers as well impact groundwater and wells.
There have been numerous discharges from land application of CAFO waste, especially during winter and this has raised concerns for regulators. Among the larger changes proposed is a ban on spreading CAFO manure in January, February, and March when the ground may be frozen and there is a higher risk of nutrients in the waste sliding into waterways rather than percolating into the soil. Some spreading could occur at the end of March with state regulatory approval.
One of the largest updates is the phasing-in of a screening tool that would replace a simple soil test for phosphorus levels when assessing the risk of manure application. The Michigan Phosphorus Risk Assessment (MPRA) would account for erosion, runoff potential, distance to surface water or a field edge, subsurface drainage, and vegetative buffers.
As of January 12, 2020, the draft version of the permit changes had not been updated to reflect any of the public comments received during December 2019. EGLE has set an April 1, 2020 target date for the implementation of the revised NDPES Permit Program. MLSA will continue to monitor this important matter for the riparians of our state.