Home > Green, Lane County, News > Lane County “caps” landfill 78 years early; methane generates enough electricity to power 1,200 homes

Lane County “caps” landfill 78 years early; methane generates enough electricity to power 1,200 homes

by Jaculynn Peterson on September 22, 2009

Lane County is constructing a 16-acre cap on a portion of Short Mountain Landfill, located eight miles south of Eugene.

“The cap is required by federal law but we aren’t required to construct it until the entire landfill is closed, which is projected to be in 2087,” said Daniel Hurley, senior engineering associate with Lane County’s Waste Management Division. “By constructing the cap now, we are reducing the methane released into the atmosphere over time rather than waiting until the end of the landfill’s lifespan to address it.”

Methane gas is 21 times as harmful a greenhouse gas as carbon dioxide, Hurley said.

The project will close a section of the landfill that was built in 1994 and received 1.5-million tons of waste from 1999-2004.

“A geotextile fabric is rolled out over the plastic cap, and this gets covered by 1.5 feet of soil, which then gets seeded with native grasses,” said Hurley.

The new landfill cap will encapsulate the garbage and enable the county to efficiently “collect” methane, which is created by the decomposition of the garbage. The county then uses the methane to generate electricity at an onsite power station, which is operated by the Emerald People’s Utility District (EPUD). The methane-to-electricity plant generates enough power for about 1200 homes.

In addition, the cap will reduce the amount of rainwater that enters the garbage, thereby reducing the need for wastewater treatment.

Construction of the cap is expected to be complete by November 3. The project is funded entirely by disposal fees collected by Lane County.

Short Mountain Landfill is located on 540 acres. Currently the site is about 160-feet high and occupies 86 acres. The landfill receives about 800 tons of garbage per day from approximately 360,000 residents in Lane County. Officials estimate that 53 percent of the waste is compostable.