Your comments are needed to ensure science prevails on Best Management Practices being evaluated by the Minnesota Pollution Control Agency (MPCA). The current proposal could prevent manure applications in many instances in September-October or February-March. They are due Thursday, July 23 at 4:30 p.m.

Disappointingly, many of the new recommendations in the proposed 2021-2026 NPDES permit follow generalities and hope for future technology, rather than science and what is available today.

Farmers, and especially those under NPDES permits, understand the value of nutrients and risk of runoff. The new proposals do not seem to understand the cyclical nature of weather and instead rely on calendar months, which disregards that the best window for applying manure may not fit neatly into certain months of the year.

We call on dairy farmers and related businesses to submit comments to MPCA using the following points. Our greatest fear is our MPCA, Department of Agriculture, Department of Natural Resources or local governments will assume these Best Management Practices are easy to implement and best for the environment. We don’t believe either are proven true.

1. Cover crops should not be required for September manure applications. While cover crops continue in adoption, we do not yet have systems in place to ensure they lead to the outcomes desired.

  • A 2005 Literature Review done by the MPCA showed that manure improves soil tilth and reduces runoff. If these are the outcomes desired of cover crops, manure application may be achieving this already (Water Quality/Feedlots 1.08, January 2005).
  • Technology developed over the next five years will likely tell us how and when cover crops can be helpful for reducing soil erosion and better water quality.
  • The current proposal does not take into account corn silage roots plus stalks or alfalfa may still be covering the soil and holding it with manure.

2. Direct injection should be added as a Best Management Practice. With rapid adoption of direct-injected manure, MPCA has never recognized it as a Best Management Practice despite its known benefits. Direct injection:

  • Limits soil compaction.
  • Preserves more soil organic matter and soil structure.
  • Allows for application to growing crops and can be similar to no-till in results.
  • Reduces risk of P runoff and particulate P loss is reduced.
  • Reduces N volatilization loss, resulting in the retention of plant-available N.
  • Reduces odor issues.

3. Proposed October Best Management Practices are not practical. Fall weather is difficult to predict, with October being one of the most variable in range from year-to-year. The use of the proposed BMPs may result in manure being applied in less than ideal conditions in November or later. For these reasons, we would suggest not implementing these October BMPs. If BMPs in October must be followed:

  • 50o F is not a magic number, but a recommendation or suggestion. Below 60o F may be just as beneficial to the environment but much more flexible to farmers.
  • Direct injection should be added as BMP.
  • The suggested cover crop BMP should be planted, not “established”.

4. Winter applications should follow field conditions, not the calendar. The University of Minnesota’s Research and Outreach Centers in Lamberton, Morris, and Waseca collectively have data showing the soil temperature above 33 o F at at least one of the centers in 2017-2020 in 24 days of the two months.

5. Minnesota Agriculture Water Quality Certification Program enrollees should have assurance. The MAWQCP enrollee farms should have assurance that their already agreed to BMPs fit within the framework of this proposal without modification.

6. Allowing manure storage beyond 14 months would help achieve some of these BMPs. One limitation in Minnesota guidance is a 14-month limit on manure storage, even when producers aim to have up to 24-months for flexibility and to obtain more BMPs. With our current 14-month limit enforced by MPCA, our manure application windows become emergencies, driving up the cost of application and hours required by applicators to apply manure in an effective manner.

Please send the following letter in, with any anecdotes for your own operation, today!

For questions or comments, contact Lucas Sjostrom –

Background: Changes are being made to the General Federal National Pollutant Discharge Elimination System (NPDES) permits. The NPDES permit applies to animal feedlots and/or manure storage areas capable of holding 1,000 animal units (715 cows) or more. The permit is reviewed every five years by the MPCA, and the agency is currently in the process of reviewing and revising the next five-year permits that will be in effect from January 1, 2021 to December 31, 2026.

Submit Comments: Comments may be submitted until 4:30 p.m. on Thursday, July 23, 2020 and should be addressed to:

George Schwint
Minnesota Pollution Control Agency
12 Civic Center Plaza, Suite 2165
Mankato, MN 56001

They may be submitted by U.S. Mail to the above address or by email to: Include a reference to “General Permit MNG440000 Animal Feedlot Permit” on the letter or on the subject line.