As food and other organics break down in a landfill, they generate gas as part of the anaerobic digestion process. Methane and carbon dioxide are the most common gases that form as food waste and organics undergo this process. In addition to gases from food waste, construction materials, especially those with high amounts of drywall, will create a gas called Hydrogen Sulfide. This can be described as a rotten egg smell and is what gives landfill gas such a potent odor. Even the tiniest amounts are detectable by the human nose.

Hydrogen sulfide is the primary “stink” component in landfill gas. It can be described as a rotten egg smell. At times, other smells such as leachate, papermill sludge, and carcasses can cause odor, but are managed to minimize off site migration as much as possible.

The primary way the landfill controls odor is through gas extraction wells. As the landfill is filled in with waste material, perforated wells are installed to syphon away gas and prevent it from drifting away from the landfill. This gas is sent for combustion in a flare system that destroys the methane and odor causing gases, leaving just carbon dioxide as a byproduct. Marathon County Solid Waste currently manages over 60 gas wells. All wells are under constant vacuum and are regularly monitored.

Uncontrolled landfill gas can cause serious health problems, but thankfully the gas at MCSWD is well controlled. What occasionally drifts from the landfill is harmless at the concentrations levels you may be smelling.

Landfill gas has the potential to travel based on many different factors. Wind, land topography, barometric pressure, and temperature all affect where odors will drift from the landfill. The amount of gas generated in the landfill also varies by the time of year, the moisture content, and temperatures.

Marathon County Solid Waste is a community resource, providing cost effective and convenient disposal for local businesses and municipalities across the region, protecting the environment from pollution and helping grow the local economy. While no one wants a landfill in their neighborhood, please understand that profits from MCSWD go back into programs to better serve the community and provide education on environmental protection and waste reduction. MCSWD works closely with Ringle to provide a significant amount of both disposal benefits and funding to help offset the costs associated with these nuisance conditions.

The Department of Natural Resources regulates the facility through both a solid waste license and an air permit. DNR engineers require regular gas monitoring for both the gas wells and any emissions escaping from the surface of the landfill. Any measured surface emissions in the monitoring process must be immediately addressed by the MCSWD staff.

As material in the landfill ages, less and less gas is produced. Once a landfill reaches its planned capacity, a clay and plastic liner system is put on top to seal the landfill in what is called the closure process. This allows MCSWD to capture any remaining gas and it limits water infiltration into the waste mass.

If you smell landfill gas, MCSWD staff are here to take your calls and will respond as appropriately as possible to any concern. The landfill is a public site, and anyone is welcome to visit to learn more about solid waste management and environmental protection.

As the need for disposal continues, additional filling areas are proposed and constructed to allow more space for disposal as DNR allows. However, the closed sites continue to be monitored for over 40 years. The land is then utilized in a manner that promotes recreation or reuse. MCSWD has utilized its facility to establish professionally recognized mountain biking courses and the National Ice Age Trail.

Marathon County Solid Waste Department can be contacted directly on this by calling:

715-446-3101 x 104 Landfill Operations

EPA and WI DNR both have FAQ documents on Landfill Gas as well