LINCOLN, Neb. -- Nebraska environmental regulators have ordered Big Ox Energy to justify why its state air quality and storm water permits should not be revoked because of numerous violations and missed deadlines.
The Nebraska Department of Environmental Quality has asked the Wisconsin-based company to provide documentation of repairs and corrective actions taken at its South Sioux City biofuels plant to prevent repeated venting of hydrogen sulfide gas into the atmosphere and solid waste spills. Big Ox also must prove that it has quit storing solid waste outside the plant and show that it has removed waste that had been stockpiled there.
A hearing has been scheduled for May 15-17 in Lincoln.
Big Ox is cooperating with the NDEQ to resolve the issues and will continue to do so in advance of the May hearing, company spokesman Kevin Bradley said.
"We are continuing to have conversations with the NDEQ, working collaboratively to come up with resolutions," Bradley said.
In his order to show cause, NDEQ director Jim Macy laid out Big Ox's history of state, federal and city violations.
Beginning in December 2017 and as recently as January, the order said, Big Ox, which converts organic waste from local industries to methane, released liquid biomass foam from its digesters, through air emission points and over sides of the facility's roof 34 times. The sludge-like material also has run off the company's property.
During a Jan. 2 inspection, NDEQ inspectors found digester solids stockpiled on the site without adequate containment, in violation of its storm water permit. As of March 5, 5,500 tons of digester waste was stored outside the plant, and more was being added daily, the report said.
Other inspections have found open roof hatches and cracks and holes in the digester roofing that allowed uncontrolled emissions of biogases and hydrogen sulfide. Big Ox has yet to show that those cracks have been fixed, the NDEQ said.
NDEQ issued notices of violation to Big Ox for air quality permit violations on July 23, Aug. 16 and Nov. 7 in 2018 and storm water and pollutant discharge permit violations on June 20, 2018. A storm water permit violation was sent to Big Ox on Jan. 7.
The U.S. Environmental Protection Agency also has issued notices of noncompliance, findings of violations, administrative compliance orders or warning letters to the company four times from Oct. 4, 2017, to Feb. 8.
The city of Sioux City, which accepts wastewater from Big Ox, also has issued the company notices of violations of its wastewater treatment permit with the city 16 times from June through February.
In many of the cases, Big Ox failed to meet deadlines to submit corrective plans and other records to the state, the order said, and the company has consistently submitted incomplete information, all in violation of its permits.
The NDEQ has asked that Big Ox provide it with a list of witnesses who will testify at the May hearing. The agency also has asked for several items of information, including a detailed report assessing the cause of the digester overflows, documentation that monitors inside the plant are being properly maintained and calibrated and a written description of actions taken to remove the waste stockpiles outside the plant.
Bradley said Big Ox intends to provide the agency with the information it has requested.
The hearing notice from the NDEQ comes days before Big Ox's industrial user wastewater discharge permit with Sioux City is up for renewal. That permit expires April 1, and city utilities director Mark Simms said Big Ox's application for renewal is currently under consideration.
"I assume that we'll reissue it, but it will have some additional stipulations," Simms said.
If the city does not reach a decision on Big Ox's permit renewal by April 1, the company will be able to continue to discharge wastewater into the Sioux City system, Simms said.
Big Ox has exceeded its daily limit of suspended solids discharged into Sioux City's wastewater treatment plant at least 33 times since June, though it has had no violations since January. The city has levied $77,500 in fines against Big Ox, which has yet to pay them, city records have shown.
Simms said he did not know until Tuesday that the NDEQ had ordered Big Ox to appear for the show cause hearing. He said he didn't know if that would have any effect on the city's upcoming decision on Big Ox's wastewater permit renewal application.
Since Big Ox began operations in September 2016, it has been the subject of numerous odor complains from South Sioux City residents living near the plant. A class action lawsuit has been filed against the company claiming that its odors are a nuisance and the result of negligence. A total of 15 homeowners have filed individual lawsuits against the company, claiming that toxic odors and gases backed up into their homes shortly after the plant began operations, causing health issues and making their homes uninhabitable.