SOUTH SIOUX CITY, Neb. (AP) — South Sioux City officials remain optimistic about the prospects for a firm that converts organic waste into fuel even though a putrid odor forced some homeowners to leave their homes after the opening of the Big Ox Energy plant there last year.
The Sioux City Journal reports (http://bit.ly/2jm0zma ) city leaders expect the Big Ox plant will reduce the burden on South Sioux City's sewage treatment plant by converting some waste to energy. That's why the city recruited Big Ox several years ago.
City Administrator Lance Hedquist says he thinks Big Ox is going to help the city, and officials have made good progress at resolving the odor problems.
"We fully think that the steps that they've taken are going to make them a positive company in the future of the city," Hedquist said.
South Sioux City sought out Big Ox partly because of capacity constraints at Sioux City's regional wastewater treatment plant. The plant's limits were constraining industrial expansion in the area.
The estimated $21 million cost of building a wastewater treatment plant just for South Sioux City was unattractive, so city officials shelved that idea.
Big Ox's operation offered the city a way to address the situation in a more cost-effective way. The company uses an anaerobic digestion process to remove organic waste and create natural gas. Then the fuel is sold into a pipeline.
"By our process being in the middle, we were able to take out of that wastewater a lot of the energy," said Kevin Bradley, director of business and economic development. "It reduces the load on that facility, thereby opening up capacity for other industrial expansion."
The source of the hydrogen sulfide that caused the smell in the homes is still being investigated. About a dozen residents remain displaced.
Big Ox stopped sending waste into the line shortly after the odors were found, but hydrogen sulfide levels continued to surge several times after that. Bradley said that suggests another source of the sulfide levels.
A new sewer line was built to reroute waste from Big Ox and several other industrial plants.
The Big Ox plant is working to get back up to full capacity.