COLUMBIA — The Columbia landfill is now one of only 10 landfills in the country, and the only one in Missouri, with the ability to more quickly create methane gas to generate electricity.
The Missouri Department of Natural Resources has approved the city's request to use bioreactor technology at the landfill to boost the creation of methane gas and, in turn, generate more electricity, according to a city of Columbia news release. There was no fee associated with the permit.
The landfill has served as a gas-to-energy plant since June 2008, capturing methane gas from naturally decomposing trash and using it to generate 1.5 percent of the city's electrical needs, enough to power 1,000 to 1,200 homes.
Once the bioreactor begins operation, the landfill could generate up to 2.5 percent of the city's electricity.
To create methane more quickly, bioreactors pump liquid into landfill cells — where the garbage is stored — to speed up the decomposition process. Conventional landfills leave the waste dry and compacted.
The process isn't perfect. Bioreactors cost more to maintain, are more likely to create strong odors and have potential for the bottom liner to fail under the weight of the wet waste. Jill Stedem, spokeswoman for the Public Works Department, said the city is prepared to deal with the issues if they happen.
The city decided to pursue bioreactor technology after voters approved a ballot measure in November 2004 that required the city to steadily increase the amount of electricity it gets from alternative sources.
City Manager Bill Watkins said the bioreactor symbolizes the "united vision launched when citizens voted to make alternative energy an increasing part of our power supply." He also said that a lot of research went into the decision to build a bioreactor and that he was happy that Columbia was one of the first to implement the technology.
"People in our Public Works and Water and Light departments worked hard to tie all this together," Watkins said. "Citizens will feel well-served and, I hope, proud that Columbia is a center of innovation."
Columbia Solid Waste Division Manager Richard Wieman did not return calls Monday but said in the press release, "This cutting edge technology will transform the operation of landfills in the future."