ABSTRACT
Subsurface landfill gas (LFG) migration may be controlled by a number of methods including air injection. This type of system utilizes a line of interconnected wells through which air is injected to develop a positive pressure in the soil to inhibit LFG migration beyond the air curtain. LFG is a product of the natural biological decomposition of organic material contained in wastes deposited in landfills. The direction and magnitude of subsurface LFG migration depends on the relative magnitude of the driving forces, the permeability of the overlying and adjacent soils, and other site conditions. Four separate LFG control systems designed by SCS Engineers have been installed at the 1–95 Landfill due to subsurface gas migration. All four are air injection type systems utilizing forced air to create a positive pressure gradient in the soils to inhibit subsurface gas migration. The basic types of LFG control systems fall into the two categories: active and passive control.
