The U.S. Department of Justice and state of Nebraska recently finalized a settlement with Big Ox Energy - Siouxland and NLC Energy Venture 30 for alleged violations of federal and state environmental laws at its waste-to-energy facility in Dakota City, Nebraska. Under the terms of the settlement, the defendants will pay a $1.1 million civil penalty to be split between the United States and Nebraska.
“The Big Ox facility’s operations presented a significant risk to their workers and nearby property owners,” said Acting EPA Region 7 Administrator Edward H. Chu. “This settlement represents the efforts of the United States and the state of Nebraska working together to enforce environmental regulations that protect citizens from harmful releases of extremely hazardous substances, especially in communities that may already experience disproportionate environmental risks.”
The Big Ox Energy facility, which opened in 2016, was designed to accept municipal and industrial waste. This liquid waste, also known as “biomass,” is converted through digesters to “biogas” consisting of carbon dioxide, methane and hydrogen sulfide, which then can be used as an energy source.
The U.S. Environmental Protection Agency (EPA) and Nebraska Department of Environment and Energy conducted multiple inspections of the facility in 2017 and 2018. The agencies found that the facility was releasing hazardous amounts of biomass and biogas. On at least 16 occasions between 2017 and 2019, biomass released from the digesters went over the sides of the facility’s roof and onto the ground where it mixed with stormwater, resulting in discharges to adjacent properties and into nearby water bodies. In 2018, a facility malfunction resulted in 80,000 gallons of biomass overflowing from the digesters. These discharges resulted in emissions of biogas, an extremely hazardous substance. Air monitoring conducted by EPA determined that the facility was emitting methane at levels that were flammable and hydrogen sulfide in amounts that could result in injury or death from inhalation.
Multiple enforcement actions were initiated against Big Ox Energy by EPA, the state of Nebraska, and city of Sioux City, Iowa, between 2017 and 2019, citing violations of the federal Clean Air Act and Clean Water Act, as well as state air and water regulations and city ordinances. As a result, the facility was required to take actions to reduce the risks posed by the emissions. Violations in the orders and notices included:
- Failure to design and maintain a safe facility
- Improper maintenance of digesters
- Failure to control accidental releases of extremely hazardous substances
- Violations of air emission standards
- Causing the Sioux City wastewater treatment plant to exceed water quality limits
- Failure to comply with EPA- and state-issued compliance orders
- Unauthorized discharges into local water bodies
- Failure to comply with air and water permits
The state of Nebraska revoked the facility’s Clean Air Act and Clean Water Act permits in 2019. Later in 2019, the facility stopped accepting waste and has since ceased operations.
Reducing risks from accidental releases of hazardous substances at industrial and chemical facilities is a top priority for EPA, which identified this goal as one of seven National Compliance Initiatives in 2019. For more information, visit EPA’s website.
