Conagra's Waseca plant fined for releasing too much hydrogen sulfide

Conagra Brands has paid more than $8 million for air quality violations at its fruit and vegetable processing plant in Waseca, Minn.

The Chicago-based packaged food company sells products under several iconic brands, including Birds Eye and Healthy Choice.

In a news release, the Minnesota Pollution Control Agency said Conagra released hydrogen sulfide above allowed levels more than 2,500 times at its vegetable processing facility in Waseca between 2020 and 2022.

The violations occurred between April and October each year. The hydrogen sulfide was released into the air outside as wastewater from the plant was being transported and treated, said MPCA spokesperson Steve Mikkelson.

Hydrogen sulfide is a colorless gas with a strong odor of rotten eggs. It can be harmful to human health, including irritating the eyes and respiratory system. At higher levels, it can cause dizziness, headaches, weakness and convulsions, according to the U.S. Centers for Disease Control and Prevention.

Mikkelson said there is no indication of any direct health effects to plant workers or others.

“This was more a case of that potential for harm, both to the environment and to potential human health, rather than an actual incident,” he said.

Conagra paid a $1.25 million civil penalty, plus more than $7 million on new equipment to reduce hydrogen sulfide emissions.

That included new piping and air filtration equipment, additional pumping stations and converting a leachate storage tank to a more modern anaerobic selector, which breaks down organic waste with microorganisms.

Conagra completed that project earlier this year, Mikkelson said, and has not had any air quality violations since. The company agreed that if it’s successful, it will share details of the technology so other Minnesota facilities can use it, he said.

A Conagra spokesperson said the company did not have any comment.