Big Ox Energy countersuit: Engineering firm, soybean processor to blame for sewer odors

Source:, July 30, 2019
By: Nick Hytrek

Facing 15 lawsuits from South Sioux City homeowners who say toxic odors and gases backed up into their homes, caused health issues and made their homes uninhabitable, Big Ox Energy has struck back.

In a recent countersuit, the Wisconsin-based biofuels company says a former ag processor and an engineering firm are responsible for odors and gas releases in the neighborhood near its plant.

The company says the blame lies with CHS Inc., a soybean processor that illegally released acidic wastewater into South Sioux City’s sewer system, and Olsson, an engineering firm that Big Ox says recommended wastewater from its plant be routed through a sewer main that ran through residential areas.

“(Big Ox Energy) did not have any input into that decision,” the company said in its countersuit, filed earlier this month in Dakota County District Court.

Big Ox also said plumbing systems in the residents’ houses did not comply with city building codes because they were not equipped with safety features to prevent odors and gases from entering their homes.

Big Ox says that if it is found responsible for any liability or damages, CHS and Olsson are wholly or partially responsible.

“(Big Ox Energy) does not believe that plaintiffs have suffered any injury or damages as a result of any actions or omissions of (Big Ox Energy),” the company said in its counterclaim.

Residents living near Big Ox began complaining of odors and gases shortly after the plant began operations in September 2016. In its filing, Big Ox said the facility is a state-of-the-art biodigester, which separates solids from industry wastewater and processes them through anaerobic digesters to create methane that is sold and injected into a nearby natural gas pipeline.

The remaining wastewater was piped through South Sioux City’s sewer system to Sioux City’s regional wastewater treatment plant on the other side of the Missouri River.

Big Ox said that when it began accepting industrial wastewater, CHS Inc., a soy protein plant located in South Sioux City’s Roth Industrial Park, was discharging wastewater that repeatedly violated state and federal acid levels. Once residents complained about odors, Big Ox stopped discharging wastewater into South Sioux City’s sewer system and trucked its wastewater to Sioux City until a dedicated sewer line was installed to handle its waste.

Though Big Ox was no longer discharging wastewater into the system, residents still complained of odors. Big Ox says the odors were caused by CHS’ release of acidic wastewater, which continued to run through the residential sewer line and reacted with sulfides present in the sewer system to cause the release of hydrogen sulfide gas.

Minnesota-based CHS closed its plant in December 2017 and later sold it to Ingredion, an Illinois-based processor. The U.S. Environmental Protection Agency later found CHS had violated federal wastewater regulations. In May 2018, the company signed a consent agreement with the EPA, agreeing to pay an $80,000 civil penalty.

CHS spokeswoman Rebecca Lentz on Tuesday said the company does not comment on pending litigation.

Rod Hanson, officer manger of Olsson’s South Sioux City office, did not return a call seeking comment.

Big Ox shut down operations at the end of April after Sioux City denied renewal of its wastewater treatment permit, in large part due to outstanding fees, fines and other charges totaling more than $3 million, a sum Big Ox is disputing. Weeks earlier, the company announced it was halting biogas production in order to inspect and repair problematic equipment that had led to solid waste spills and releases of hydrogen sulfide gas into the atmosphere.

Residents have filed a separate class action lawsuit against Big Ox in federal court claiming that its odors are a nuisance and the result of negligence.

The plant has been cited for environmental and permit violations a combined nine times by the EPA and Nebraska Department of Environmental Quality, prompting the NDEQ to call for Big Ox to justify why its storm water and air quality permits shouldn’t be revoked.

At a hearing earlier this month, state regulators announced Big Ox had until Sept. 9 to report any further issues pertaining to energy production and to properly take care of environmental issues at the facility. Big Ox may not resume operations prior to that deadline.

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