Abstract: This invention is a new and useful method for controlling the temperature and biodegradation rate of an anaerobic or aerobic landfill or other enclosed or partially enclosed waste mass. The heat generated by a waste mass is carried away by air and moisture within the air resulting from evaporation of liquid within the waste mass as air passes through the waste mass. With the invention, the resulting exhaust gases are passed through a system acting as a heat exchanger and an exhaust gas director.

Abstract: A new and useful method and system for estimating LFG generation and gas permeability in a landfill or other subsurface-gas producing body of material is provided. The gas generation rate in a portion of a landfill or other subsurface-gas producing body of material is estimated by obtaining a time history record of atmospheric pressure that is representative of atmospheric pressure at a surface boundary of the portion of the landfill or the subsurface gas producing body of material, measuring the gas pressure at least at one selected location at the landfill (or subsurface body of material) site over a time period that is included in the time history record, and using the atmospheric pressure and the measured gas pressure over the time period to estimate LFG generation rate and gas permeability of the portion of the landfill or the subsurface gas producing body of material.