And while the Phoenix-based solid waste management company said it continues to work on odors at the Imperial landfill in Findlay Township near Pittsburgh, the state Department of Environmental Protection said the company has not yet "effectively controlled off-site odors."

The company said there are "no known threats" regarding the odors.

The civil penalty covers violations from December 2005 to November 2009 "with the majority of the violations occurring since January 2009," the state said.

Republic Services has spent more than $1 million dealing with odor issues at the landfill during the past year, the company said.

That work includes the hiring of American Environmental Group Ltd. to monitor and balance the landfill´s gas extraction system. The company also installed 33 gas wells within the landfill´s active area added 18 submersible pumps within those wells to keep liquid out, allowing the wells to collect and extract gas, the company said.

The company also installed a plastic geomembrane cap over 12 acres to aid in the collection of gas and installed misting equipment to minimize odors when necessary.

"The department began investigating Imperial after receiving numerous complaints from residents around the landfill and from teachers and staff at nearby Wilson Elementary School," said DEP Southwest Regional Director George Jugovic Jr. "While management at the landfill has taken some steps toward improvement, they have not yet effectively controlled off-site odors."

The state has received additional odor complaints during the past two months, the DEP said.

"We have done significant work to address odors," said Brent Bowker, general manager for the landfill. "We continue to work to ensure that our facility is operated safely and to continue to be a good neighbor in our community."

The company plans to expand the landfill´s gas collection system this year. That work includes the placement of more gas extraction wells and piping. The company says it will install more plastic, or geomembrane, cover and increase odor scans.

The company also said it "enhanced the winterization of various landfill gas components to increase their operational capacity during freezing temperatures" and enclosed both leachate and landfill gas condensate equipment to minimize odors.

"This is a significant fine that closes the books on DEP´s alleged violations over a 4-5 year period and allows us to give our attention to current operations and conditions," Bowker said. "We are committed to continuing to address landfill management issues with the state, the county and the community."

"Based on air sampling over the last year or more, there are no known threats, but we continue to address odor issues," he said.

Contact Waste & Recycling News senior reporter Jim Johnson at 937-964-1289 or jpjohnson@crain.com