Landfill gas production testing and extraction method

摘要

A method for determining total landfill gas production capability and pollutant emission rates involves measuring gas pressure in a soil cover at various locations around the landfill. These measurements are preferably made successively and repeated. The tester determines an average gas pressure and its spatial uncertainty envelope and measures soil pneumatic permeabilities by taking soil samples, preferably at various locations. The soil is tested to determine viscous and inertial resistance coefficients to characterize permeability. The gas composition is determined preferably at each pressure measuring location, and the coefficients, gas pressure and composition measurements are used to calculate total gas emission. A method of controlling gas extraction so that gas pressure in the soil cover approaches or becomes atmospheric pressure includes measuring gas pressure and relative permeability of the soil at various locations, relative flows of air into, or landfill gas out of, the surface are determined, and the extraction pressures at collection wells are adjusted in view of the flow through the soil until the relative flow at each location is zero or substantially zero.