Allen County commissioners were told Tuesday substantial upgrade of the gas collection system at the county landfill a mile southeast of LaHarpe would cost about $450,000.
More stringent regulations from the federal Environmental Protection Agency and Kansas Department of Health and Environment dictate the project.
No tax money will be involved. Bill King, director of Public Works, said about $600,000 was in the landfill fund, which grows monthly with deposits of tipping fees and proceeds from a countywide half-cent sales tax.
“We take in about $1 million a year,” with about half coming from each source, King said.
The fund is set aside for such projects, and to pay for landfill expansion, which was done two years ago at a cost of $2 million.
THE LANDFILL opened as it is today in 1995 and gas collection began six years later, initially with all flowing from degenerating organic material burned through an elevated flare. Gas is collected through 16 wells.
In 2003, the county started using the gas to heat the landfill maintenance building through an infrared system. First indications that the system wasn’t operating up to snuff surfaced in 2006, when weekly tests showed gas quality was dropping. A year later gas quality was too poor to support the heating system.
Brian Weis, an engineer with Burns and McDonnell, Kansas City, told commissioners the degradation of the gas was caused by infiltration from the atmosphere, caused by failure of components in the well heads and along underground pipes that transport gas just above the landfill’s encapsulating plastic liner.
Valves in the wellheads also have worn to the point they no longer can be calibrated with required accuracy, Weis said. Monitoring points at the edges of the closed landfill also have exceeded their useful lives, he said.
While upgrade will cost about $450,000, with about half for a more sophisticated flare, expenditure won’t come all at once, Weis said, rather in several doses throughout the year and perhaps into 2013. Initially, Burns and McDonnell will solicit bids for well components and the flare, which will take a few weeks.
WEIS SAID gas collected needed to contain at least 40 percent methane for the burner and heating system to work properly.
“Currently, it’s running quite a bit less than that,” because of the infiltration, he said. “What you’d normally expect is 45 to 50 percent methane.”
King said the closed portion of the landfill, where methane is collected, covers about 15 acres and contains 50 to 60 feet of buried trash and debris, much of it gas-producing organic material.
