Nearly a year after methane gas was found outside the boundaries of Mallard Lake Landfill in Hanover Park, environmental officials have announced a plan to continue dealing with the leak.

BFI Waste Systems, which operates the closed landfill at Mallard Lake Forest Preserve, has been working with the U.S. Environmental Protection Agency to contain the potentially explosive gas since it was detected in November. The U.S. EPA held two public meetings Wednesday at Hanover Park Village Hall to inform residents about the plan.

“BFI strives to ensure that its actions mirror the company’s long-standing commitment to the safety and well-being of its neighbors, customers and employees,” the company said in a statement released Wednesday. “As consistently done throughout the investigation, we will continue to be responsive to all state and federal agencies, local and state officials and residents and do our part to keep them informed of ongoing activities.”

Methane is a colorless, odorless gas naturally produced by decaying garbage in landfills.
Last year, testing showed the gas had escaped from the landfill’s collection system and migrated west off the landfill site, according to the EPA. The gas was confined 40 feet below ground and has not been detected in any of the nearly 250 homes that have been tested.

To deal with the problem, BFI has installed six additional gas-collection wells along the perimeter of the landfill to collect methane before it reaches the boundaries. The company has also upgraded the on-site gas collection system, including the addition or replacement of more than 15 wells and improvements to portions of the landfill cover.

The company’s statement said these measures have been working to reduce the amount of gas outside the landfill. No methane was detected in 12 probes that previously tested positive for the gas, and concentrations in those probes that still contain methane are steadily decreasing, according to BFI.

In the future, BFI plans to install seven more gas-collection wells beyond the perimeter of the landfill and to continue monitoring its existing probes.

The methane leak is not the first environmental problem associated with the landfill.

In 2005, the Illinois EPA detected a hazardous chemical called vinyl chloride in the wells of several homes in Wayne Township near Carol Stream. Vinyl chloride is created by mixing certain industrial chemicals found in older landfills, according to the IEPA.

Homeowners have filed a federal lawsuit against BFI and the Forest Preserve District of DuPage alleging that the landfill is responsible for the contamination, but the IEPA has said there is no evidence to support that claim.

Last week, a federal judge denied BFI’s motion to have the lawsuit thrown out.