Subsurface Elevated Temperature (SET) Events in Municipal Solid Waste Landfills

This paper documents six case histories in the United States (US) involving subsurface elevated temperature (SET) Events in municipal solid waste (MSW) landfills to understand the cause(s) of such events. This is important because once an SET Event initiates in an MSW landfill, it is difficult to slow and usually results in a “wait and see” approach, which subjects the surrounding community to long-term exposure to noxious odors, volatile organic compounds (VOCs), and other contaminants. This “wait and see” approach also allows the elevated temperature from an SET temperature event to: (1) expand and consume or thermally degrade additional MSW, (2) damage the bottom liner and landfill gas control systems, (3) create problematic leachate, and (4) decrease slope stability. As a result, understanding the cause(s) of the prior major SET Events or case histories is important so that operating MSW facilities do not initiate such an event and if they do what monitoring and remedial actions they should implement.