Waste Management implementing plan to stop methane leak

Waste Management officials said Wednesday they have a logical theory about why and how methane gas from decomposing trash migrated off its Midway landfill and into Batavia.

Jack E. Dowden, group director for Waste Management's Midwest closed sites, believes the gas has found a new path of least resistance to escape the landfill. Now Dowden and his team are working to trace that path and lasso the gas back into the collection system for the Midway and Settlers Hill landfill campus.

The two adjacent landfills have dramatically different infrastructures, Dowden said. Settlers Hill was constructed with the most modern landfill lining and monitoring systems. Midway was opened mostly as a big hole dug in the ground that people just tossed trash into until it was closed in the early 1980s.

Beneath the landfills is a mix of soils including a layer of clay that typically traps methane underneath it. But in other parts of the site is a mix of sand and gravel. That sand and gravel has traditionally also trapped the gas because it has been saturated with water. As a result, the path of least resistance for gas to escape has been the vacuum collection system installed as a web over the entire landfill campus.

However, as the area around the landfill has come to be developed, the water in the gravel and sand layer may have dissipated more and more as the demand on the local water supply rose and more water pumps and dewatering systems came to be installed in proximity to the landfill. Dowden and his team believes that may have resulted in some pockets of the sand and gravel layer becoming a new path of least resistance for the methane.

The trick now is figuring out how that new path is working and then implementing a system to keep it from escaping the site. Dowden believes they already know how to make that system work. A few years ago, Dowden's team found elevated methane emissions escaping into the old Campbell House by Elfstrom Stadium and reworked the vacuum system to solve that problem.

Right now, Dowden's team is doing some exploratory drilling and monitoring to figure out where the methane is and isn't. Once that's determined, more vacuums can be installed in the right places to capture the gas.

Waste Management Spokesman Bill Plunkett said the company has both an environmental obligation and a financial incentive to get the situation under control. Waste Management turns the gas into electricity it sells to the city of Geneva to power about 10,000 homes.