SUMMARY: A study is conducted to determine the thermal regime within and around a
municipal solid waste landfill located in midwestern U.S.A. Spatial distributions of
temperatures have been determined over time since 1999 within the waste mass, liner and cover
systems, and surrounding subgrade. Seasonal variations, placement of waste, age of waste,
depth and location of waste, and available moisture have significant effects on temperatures.
Temperatures of wastes at shallow depths, bottom liner systems prior to waste placement, and
final cover systems conform to seasonal temperature variations. Steady elevated temperatures
are reached with respect to air and ground temperatures at central locations and at depth in the
waste mass. Increasing trends are observed for temperatures in wastes and bottom liner systems
in cells containing newly placed wastes. It is estimated that waste temperatures increased due to
effects of leachate recirculation at portions of the facility. Subgrade temperatures at the
perimeter of the landfill have not yet been significantly affected by the presence of the facility.