MANKATO — Blue Earth County is seeking a state permit to increase the size of its landfill by 80 percent as well as increase the amount of gas the landfill generates as part of a gas-to-energy project.
The 16-acre expansion would raise the landfill’s capacity from 2.95 million cubic yards to 5.31 million cubic yards.
Because the expansion is greater than 25 percent of the previous permitted capacity, an environmental study was completed by the Minnesota Pollution Control Agency.
The public has until March 6 to comment on the study, a copy of which is can be found here.
The MPCA has made a preliminary decision to approve the application, though objections could trigger a contested-case hearing.
The expansion is unlikely to be controversial, said Scott Fichtner, the county’s environmental services director.
“People understand that it’s there, that there’s a need for a landfill,” he said.
Using current rates of trash accumulation, the landfill would run out of space by 2018. The expansion will give it enough room for perhaps 20 years.
The expansion request is accompanied by a project to recirculate water through the trash in a bid to turn decomposing garbage into electricity.
As trash decomposes, it releases methane, a “greenhouse gas” that contributes to climate change. The landfill gives off a lot of methane — 1,345 metric tons in 2011. Of that, 797 tons — the carbon dioxide equivalent of 1,060 average Americans — was released and 548 tons were burned off by a flare at the site.
Fichtner said the estimates for the methane production are a subject of debate in the scientific community, and there is some concern that it overestimates the amount of pollution.
Instead of burning the methane off, the county would like to harness it. The problem is, the trash doesn’t currently generate enough methane for such a project to be feasible.
But trash decomposes more quickly when wet and gives off more methane. The county would like to recirculate rain water around the landfill so it generates more methane. After about a year of data collection, perhaps in mid-2014, the county should know whether or not the methane is sufficient.
Though the total permitted increase at the landfill is 2.36 million cubic yards, the county will continue its practice of expanding the landfill slowly, by one or two areas, or “cells,” at a time.
This summer the 11th cell will be constructed. They cost roughly $500,000 to build. The cells aren’t the simple dumping grounds of decades past — they include protections such as a 2-foot compacted clay liner, high-density plastic and a 1-foot layer of sand.
The expansion should not affect the landfill’s history of paying for itself through “tipping” fees to dump there.
The county acquired the landfill in 1996.