116 3rd St SE
Cedar Rapids, Iowa 52401
State investigating safety after blasts at Marengo recycler
Crews fought to keep fire from reaching tank of possible marine-grade diesel

Dec. 9, 2022 5:04 pm, Updated: Jan. 26, 2023 10:58 am
MARENGO — For weeks before blasts tore through a Marengo recycler and injured at least five people and caused nearby evacuations Thursday, public safety officials were trying to get the company to disclose what hazardous chemicals were on site.
Marengo Police Chief Ben Gray said that since a smaller fire at the C6-Zero facility Oct. 25, the police and fire departments had concerns about the plant — which says it turns old shingles into alternative fuels — and the departments were attempting to work with the company to determine the potential hazards on site.
“We simply wanted to know what chemicals were on site,” Gray said Friday. “That way we were aware of what both our emergency responses should be in order to treat chemicals on site and from a potential risk mitigation hazard for citizens.”
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Until Thursday, when the company disclosed the information during firefighter efforts to contain the fire, officials did not know the makeup of the mixture, Gray said.
“We can’t share at this time what the makeup of the mixture is,” Gray said.
Iowa OHSA Administrator Russell Perry said an investigation is being opened into the plant to determine what happened. The organization, part of the Iowa Department of Labor, regulates the health and safety of workers and has authority to issue fines.
“It’s ongoing,” Perry said. “That’s all I can really say right now. We are aware of it and we will conduct an investigation.”
Building housed shingle recycling company
C6-Zero has operated in Marengo for about two years, Gray said. Before that, the building at 810 E. South St. was used by Heartland Crush LLC, which operated a grain elevator and soybean crushing plant there beginning in 2017.
Heartland Crush ran into problems in 2018 when the Iowa Department of Agriculture determined the company had started — but never completed — the process of obtaining a grain dealer license. The state agency took over receivership of grain at that time and found $1.1 million of unpaid grain.
Property records show the building still is owned by Heartland Crush. It is listed for sale by Skogman Realty at a list price of $899,000.
Gray said the city knew C6-Zero was using the building to recycle shingles. As of three weeks ago, he said, C6-Zero had 20 to 25 employees working there.
Attempts to reach the company for an interview through a public relations representative listed on its news releases were unsuccessful Friday. It posted a brief statement on its website Friday:
“C6-Zero experienced an explosion and fire inside its facility in Marengo on Thursday. At this time, our focus is on our employees and their families affected by this accident and ensuring they receive the appropriate care and support. We are working with appropriate local officials, and are deeply grateful to the many firefighters, first responders and hospital staff who worked tirelessly to safeguard our employees and our neighbors in the community over the past 18 hours.”
C6-Zero’s company website says it “takes asphalt singles out of landfills, and alleviating the need to dump them in the first place, remanufacturing them into eco-friendly, carbon negative products: Aggregate, Fiberglas and Biofuel.”
A video on the website explains the process as using “a large washing machine” filled with a proprietary solution to separate the fiberglass, oil and sand from the shingles. Those products are then sold to be reused and repurposed, according to the website.
“6-Zero Advanced Biofuel delivers environmentally sound, economically advantageous, and high performing fuel solutions to improve your enterprise,” it advertises.
Iowa Renewable Fuels Association Executive Director Monte Shaw said C6-Zero is not a member of the association.
“This company was not really on our radar. What they’re doing does not qualify as a biofuel or renewable fuel,” Shaw told The Gazette. “Those have to come from solar, wind and crops. What they do may qualify as an alternative, petroleum-based fuel, because shingles start with crude oil. It could have great environmental impacts, but it’s not a biofuel.”
Earlier this year, the company and its founder, Howard Brand III, were sued by Iowa company TMC Drafting Services, for unpaid invoices of $24,496 after the company did branding and drafting work for C6-Zero, according to court filings.
In filings in the ongoing lawsuit, C6-Zero is described as “an inactive limited liability company formerly organized in Iowa” and “C6 Iowa” as a “limited liability company organized in Wyoming and registered as a foreign limited liability company in Iowa.”
Brand III, originally of Alaska, has established or sought to establish similar plants around the country — including Idaho and Colorado — according to local news articles.
Firefighters feared flames would reach interior tank
Two hundred firefighters from a 50-mile radius around Marengo battled the blaze for nearly 18 hours Thursday and Friday. Iowa County Emergency Management Coordinator Josh Humphrey said they fought hard to keep flames from reaching a tank in the central part of the building that was thought to contain marine-grade diesel and solvents.
“The tanks had a capacity of 120,000 gallons,” Humphrey said. “We didn’t know exactly what was in them or how much they contained, but we fought the fire aggressively to keep it from reaching the center of the building. If the fire had reached those tanks, we would have had to evacuate the whole town.”
Evacuations during the fire were limited to the houses in the plant’s immediate vicinity. Evacuated residents were allowed to return home about 7 p.m. Thursday.
It is unclear what caused Thursday’s explosions and fire, but Gray said the fire Oct. 25 was caused by work being done inside the plant.
“They were doing some welding and caught a diesel tank with some combustible material on fire,” the police chief said. “It was certainly concerning at the time. That fire did not have the explosive nature of this one so there wasn’t structural damage. It was contained to a singular area of the factory.”
Now, with the fire extinguished, there are remaining questions. For the city of Marengo, those questions surround the costs associated with this week’s emergency response.
“We are concerned about recouping those costs,” he said. “We’re also concerned that the cleanup of the site is completed in a timely manner.”
Melinda Wichmann of The Pioneer-Republican contributed to this report.
Comments: (319) 398-8255; gage.miskimen@thegazette.com
The loading dock at the C6-Zero facility in Marengo is seen Friday, a day after two explosions and a fire injured multiple people and forced evacuations nearby. The facility says it coverts used roofing shingles into fuel and other products. (Jim Slosiarek/The Gazette)
The loading dock at the C6-Zero facility is seen Friday, a day after two explosions and fire at the building in Marengo. Multiple people were injured in an explosion at the facility that coverts used roofing shingles into fuel and other products. (Jim Slosiarek/The Gazette)
Smoke billows Thursday from the C6-Zero facility in Marengo after explosions and a fire injured multiple people and forced nearby evacuations. The fire was finally put out at 4 a.m. Friday. (Jim Slosiarek/The Gazette)
Part of the C6-Zero facility is reflected on water Friday, a day after two explosions and fire at the building in Marengo. (Jim Slosiarek/The Gazette)
The C6-Zero facility is seen Friday, a day after two explosions and fire at the facility in Marengo. (Jim Slosiarek/The Gazette)