Fremont wood pellet plant investigated for releasing excessive dust 5 months before fatal blast

In January, a neighboring business filed an air quality complaint with the Nebraska Department of Environment and Energy against Horizon Biofuels, alleging that sawdust from the plant was accumulating on their cars and clogging drainage ditches, which inspections from the state department and Fremont city officials later confirmed.

Lenny Huff, an environmental specialist with the department, said in the report that Chad Schoeneck, the plants’ general manager, indicated there might be an issue with the baghouse, a filter used to remove particulates from air released during industrial manufacturing.

Horizon Biofuels recycled discarded shipping pallets from local businesses, as well as waste lumber from building manufacturers, grinding them into wood pellets for heating fuel and animal bedding.

At the time, the plant was shut down due to the extreme cold, but Schoeneck told regulators the company would do a full plant inspection once it warmed up, according to the report.

Officials with the Nebraska Department of Environment and Energy said Thursday they could not provide details of any actions Horizon Biofuels might have taken as a result of the inspection, “as the agency did not receive correspondence from them on that topic.”

Messages left with Schoeneck were not returned.

The City of Fremont ordered Horizon Biofuels in February to clean up the sawdust that had accumulated in storm drains.

The Nebraska State Fire Marshall’s office said two days after the July 29 blast an accidental dust fire during the manufacturing process is believed to have caused the explosion that killed Dylan Danielson, 32, an employee of the plant, and his daughters Fayeah Danielson, 8, and Hayven Danielson, 12, who he brought to work that day.

The fire marshal’s office has not provided additional details, saying the instability of the structure is limiting further investigation efforts.

Patrick Anderson, a senior attorney with the Southern Environmental Law Center, reviewed the Department of Environment and Energy report at the request of The World-Herald and said that while air quality complaints are fairly common for wood pellet facilities, the baghouse issue could be a sign that maintenance wasn’t being kept up.

“Dust fire and explosions tend to happen more often when you don’t have a good control over dust in your environment,” he said.

Anderson previously worked for the Environmental Integrity Project and co-authored a report on the environmental impacts and dangers of pellet facilities. He highlighted in the report a photo of the facility’s interior, noting an unusually large amount of dust on the equipment. He compared Horizon Biofuels to larger facilities pf which he’s seen photos.

“Whenever you see images of the interior of those, I don’t recall seeing that much dust,” he said.

Based on the report, Anderson said it’s possible that the baghouse could have contributed to conditions that led to the blast; however, investigators have not made that determination.

Aaron Yoder, an associate professor at the University of Nebraska who specializes in agriculture safety, said the Fremont explosion follows a pattern he’s seen studying grain dust explosions. Wood materials in a manufacturing plant break down to fine, powdery dust that could lead to an explosion if dispersed in the air of an enclosed area in the presence of oxygen and an ignition source like a spark or hot surface.

Yoder also reviewed the report and said conditions seemed “typical” for that type of facility.

The U.S. Chemical Safety Board and Occupational Safety and Health Administration are among the agencies investigating the plant explosion.

“This horrific incident should never have happened,” Chemical Safety Board chairperson Steve Owens said in a press release. “We want to prevent a terrible tragedy like this from occurring again.”

Schoeneck, in a statement two days after the blast, said Horizon Biofuels will fully cooperate with investigators.

A Chemical Safety Board spokesperson told The World-Herald that a team has met with Horizon Biofuel officials and first responders and has further meetings planned with local and county building and engineering departments.

However, the ongoing fire, which has persisted for over a week after the blast, and structural instability at the plant, has impeded further investigation efforts for the time being.

OSHA previously investigated the plant in 2012 and found that Horizon Biofuels failed to ensure that wood dust did not accumulate around the milling machine, posing a fire hazard.

The agency lists dust as an explosion hazard and states, “Any combustible material can burn rapidly when in a finely divided form.”

The violations initially resulted in $12,000 in penalties but were reduced through informal settlements to $6,000, according to records. All of the violations were marked as abated within two months.

In a statement announcing the investigation into Horizon Biofuels, the Chemical Safety Board noted the agency had investigated similar dust explosions such as the 2017 explosion at the Didion Milling Inc. dry corn milling facility in Cambria, Wisconsin. There, investigators found combustible corn dust ignited inside processing equipment that caused multiple explosions in the facility, killing five and injuring 14.

Their investigation revealed negligence, finding that Didion lacked safeguards in the mill’s design and had a poor safety culture that prevented them from recognizing and addressing combustible dust hazards.

Horizon Biofuels was also the site of a fire in 2014 in its grain elevator, which damaged electrical equipment. The cause of that fire was not immediately available. The plant returned to operations within six months, according to previous World-Herald reporting.