IEC comments to DNR on new Supreme Beef NMP

posted on Thursday, August 10, 2023 in Water and Land News

This week, the Iowa Department of Natural Resources (DNR) took comments and held a public hearing on Supreme Beef’s latest attempt at a Nutrient Management Plan (NMP). The new NMP comes after a Polk County District Court reversed the DNR’s approval of the feedlot’s February 2021 NMP due to what the judge called “illogical” interpretations of the law.  

Unfortunately for Supreme Beef, the new NMP has many of the same problems as previous NMPs. It does not comply with Iowa Administrative Code requirements. IEC’s statement to the DNR at Tuesday’s public hearing, and our written comments, included significant concerns that Supreme Beef: 

  • makes unfounded assumptions regarding manure nutrient content; 
  • proposes over-application of manure; 
  • does not properly address conservation practices; and 
  • will pose a threat to water quality in this vulnerable, ecologically unique region of Iowa.

We once again call on the Iowa DNR to deny this Nutrient Management Plan for Supreme Beef.

What this NMP Gets Wrong

First, the NMP relies on manure nutrient concentrations that are inconsistent with DNR guidance and findings from independent research. Further complicating the issue, Supreme Beef provided information in the NMP about removing solids from the liquid manure and applying those products separately to fields. The pages regarding the solids application were only distributed on Wednesday of this week. The removal of solids creates different nutrient concentrations in the solids and liquid. We are still reviewing those calculations, but we know that right now, the facility is not removing the solids from the liquid.

The foundation of an NMP is the nutrient output from the manure in the facility. If these numbers are wrong, everything in the NMP is wrong. We will include details of our review in the comments IEC submits to DNR.

tractor spreading manure on fieldSecond, the NMP still overapplies manure. If a field has a high amount of phosphorus in the soil to start with, no manure can be applied. Each field must be assessed for risk of phosphorus loss. The claims in the Supreme Beef NMP about the fields that would receive manure are unverified. Supreme Beef claims erosion-reducing terraces where none appear to exist. It also claims identical information for multiple fields.  

Even using the incorrect numbers that Supreme Beef provides, there are mathematical errors. DNR has admitted in response to a records request that it does not have all the underlying data for the assumptions made in the phosphorus assessments. The phosphorus assessment is not just technical or regulatory for its own sake; applying manure in excess of the amount needed by crops will lead to nutrient loss that can pollute ground and surface water. 

Bloody Run CreekFinally, the DNR has authority to evaluate open feedlots for adverse impacts on natural resources or the environment. The numerous deficiencies in this NMP are important because this site poses risks to water quality. Bloody Run Creek is an Outstanding Iowa Water and a rare Iowa cold-water trout stream, flowing through karst terrain. Karst is particularly vulnerable to water contamination between surface and ground water, and excess nitrogen and phosphorus could cause significant harm to aquatic life. Proposed manure application fields are in the Bloody Run Creek watershed. Supreme Beef significantly increases the cumulative risk of pollution in the watershed. 

Each of these deficiencies independently provides a basis for DNR to deny the NMP, but together there should be no question of denial. IEC will submit comments to DNR next week with more thorough explanations of the issues. 

If you would like to request a copy of the NMP or make comments, contact (Please note that DNR will only consider comments on whether the NMP complies with the Iowa Administrative Code feedlot rules.) 

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