Landfill Temperatures under Variable Decomposition Conditions

This study was conducted to evaluate temperature, gas, and leachate data at two landfills in similar climatic regions (Detroit, Michigan, USA and Asahikawa, Hokkaido, Japan) to determine the interrelations between heat production and resulting waste temperatures and gas and leachate levels in landfills under variable decomposition conditions. Significant temperature increases occurred under long-term anaerobic conditions. Stable elevated temperatures under anaerobic conditions were observed for wastes at central locations. Seasonal fluctuations in both temperature and gas existed at shallow depths and near perimeter locations. Placement of an overfill of fresh wastes over old wastes affected temperatures, yet did not significantly influence existing anaerobic conditions. Temperatures increased at shallow depths and decreased at greater depths to reach the characteristic waste temperature profile observed in landfills located in temperate climates. Introduction of semi-aerobic conditions using passive gas vents resulted in high temperature variations. Heating and cooling were both observed, depending on vent location with a net heating effect of 1.3 to 3.0°C over 4 years. Temperatures of wastes below a leachate mound were low and varied less in comparison to wastes above the leachate mound under semi-aerobic conditions. Waste temperatures were lower above high leachate mound than low leachate mound.