More methane, lower risks
Abstract
As the number of landfill gas-collection systems has grown, suboptimal methane production is a significant financial issue for many operators under contract to provide gas. Unrelated but noteworthy is the threat posed to nearby groundwater from fugitive leachate and subsurface gas migration. A third issue is the cost of providing electrical and/or pneumatic power to new or closed landfill cells, particularly at remote sites.
The Cedar Rapids/Linn County Solid Waste Agency (Agency), which serves Iowa’s second largest county, determined in 2011 that leachate was negatively impacting gas production. As an ameliorant, contracted engineers suggested reducing liquid levels in gas-collection wells using low-flow pumps and testing the viability of employing solar-powered pumping for efficiency and cost savings. The firm conducted a four-month test at a 30-acre cell at roughly 42º North latitude during the winter of 2011-2012.