Rendering facility fined $3 million for air violations

MN MPCA News

Filed March 26th, 2026

Detected March 27th, 2026

Summary

The Minnesota Pollution Control Agency (MPCA) has fined Central Bi-Products $3 million for air quality violations related to hydrogen sulfide emissions and improper wastewater treatment. The facility has also agreed to spend over $4.4 million on improvements to prevent future pollution. A portion of the fine will benefit the local community.

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What changed

The Minnesota Pollution Control Agency (MPCA) has issued a $3 million fine against Central Bi-Products for repeated violations of hydrogen sulfide emission limits and improper operation of its wastewater treatment systems. The violations, which occurred from fall 2023 through 2024, included exceeding hydrogen sulfide limits significantly more often than permitted and failing to accurately report issues with floating materials in its pond treatment system. The MPCA investigation found that the facility emitted higher levels of hydrogen sulfide, causing odor complaints in Long Prairie.

Central Bi-Products must pay $3 million, with $1.2 million directed to the Todd County Community Health & Human Services Department. Additionally, the company has committed to spending at least $4.4 million on supplemental environmental projects to improve wastewater treatment and control hydrogen sulfide pollution. Required actions include upgrading pretreatment systems, preparing corrective action plans, maintaining treatment chemicals, conducting air monitoring, holding public meetings, and creating a public webpage detailing monthly hydrogen sulfide emissions. Failure to comply with these terms could result in further penalties.

What to do next

Improve wastewater pretreatment systems
Prepare and submit a revised plan for corrective actions if additional hydrogen sulfide levels exceed permit standards
Maintain an adequate supply of treatment chemicals for hydrogen sulfide
Conduct air monitoring from April 1 – Oct. 31
Hold public meetings regarding environmental compliance, odor impacts, and operational changes
Create a publicly available webpage with a summary of monthly hydrogen sulfide emissions

Penalties

$3 million fine, with $1.2 million directed to Todd County Community Health & Human Services Department. Facility must spend a minimum of $4.4 million on improvements.

Source document (simplified)

News release

March 26, 2026

Contact

MPCA communications, news.mpca@state.mn.us

Long Prairie rendering facility fined $3 million for air quality violations and has agreed to spend more than $4 million to improve its wastewater treatment

Central Bi-Products emitted higher levels of hydrogen sulfide than is allowed, causing odor complaints in the community of Long Prairie and resulting in a $3 million fine following an investigation by the Minnesota Pollution Control Agency.

The Todd County Community Health & Human Services Department will receive $1.2 million of the $3 million fine.

Specifically, the MPCA investigation found that Central Bi-Products violated a hydrogen sulfide limit of .03 parts per million 485 times when the regulation only allowed it to go over that limit twice in five consecutive days. Central Bi-Products also violated a hydrogen sulfide limit of .05 parts per million 427 times when it was not to go over that limit more than twice a year. The MPCA investigation found that Central Bi-Products failed to properly operate and maintain its wastewater pretreatment systems, which then overloaded its pond treatment system, creating the hydrogen sulfide levels that were beyond allowed limits.

The violations took place from fall 2023 through 2024.

Under 2023 legislation, the MPCA directs 40 percent of fines of more than $250,000 to the community affected by that pollution. With the community’s input, the Todd County Community Health & Human Services Department will use its portion of the fine to fund projects that benefit area residents.

Hydrogen sulfide can be created when wastewater has been improperly treated. Health effects of hydrogen sulfide are generally only associated with exposures that are many times higher than typical background concentrations. These effects are heavily dependent on both the amount and duration of exposure. At elevated levels, symptoms can include temporary eye, nose, or throat irritation, headaches, and, in some cases, breathing difficulties for people with asthma.

The facility also provided inaccurate information on monthly discharge monitoring reports required by its permit from September 2023 to December 2023. Central Bi-Products reported that it had no issues with floating materials within its pond wastewater treatment system, when in fact the system had significant issues.

Central Bi-Products has agreed to spend a minimum of $4.4 million on a supplemental environmental project that will ensure that the facility sufficiently treats its wastewater and controls hydrogen sulfide pollution in the future.

To come back into compliance with its permit, Central Bi-Products has agreed to:

improve wastewater pretreatment systems
prepare and submit to the MPCA a revised plan for corrective actions if additional hydrogen sulfide levels exceed the permit standard
have an adequate supply of treatment chemicals for hydrogen sulfide
conduct air monitoring from April 1 – Oct. 31
hold public meetings regarding facility’s environmental compliance, impacts on odor, and operational changes made to improve wastewater management
create a publicly available webpage with a summary of the facility’s monthly hydrogen sulfide emissions The MPCA remains committed to protecting human health and the environment by enforcing rules and regulations and limiting pollution and discharges from facilities. When facilities do not fully comply with regulatory requirements, the resulting pollution can be harmful to people and the environment.

When calculating penalties, the MPCA considers how seriously the violations affected or could have affected the environment, and whether they were first-time or repeat violations. The agency also attempts to recover the economic benefit the company gained by failing to comply with environmental laws in a timely manner.