A small percentage of municipal solid waste (MSW) landfills in North America are experiencing elevated temperatures of 200°F, 250°F, or higher.

In addition to safety concerns for vehicles and workers, the owners of these sites typically experience challenges with the landfill gas collection and leachate management systems from softening/collapsing pipes and excessive amounts of high-strength leachate in the waste. Regulators have understandably raised questions about the longevity of the liner and cover systems in ETLFs and the stability of the waste surface and sideslopes.

The exact reason for the elevated temperatures is often not known. Fire has been ruled out at these facilities, microbial activity in landfills alone does not generate enough heat to produce temperatures of this magnitude, and although some of these landfills have received industrial wastes that may produce exothermic energy, others have not.

In addition to elevated temperatures, ETLFs typically exhibit:

  • Reductions in methane generation and increased presence of other gases such as hydrogen;
  • Large and rapid subsidence of the waste surface (sink holes); and
  • Increased liquid and gas pressure in the waste.

Research

Geosyntec Consultants plays a key role in ETLF research. Since 2012, our practitioners have been integral members of research work spearheaded by the Environmental Research and Education Foundation (EREF) to advance the state-of-the practice in understanding and predicting temperatures in MSW landfills. The research has led to the publication of several journal article and conference presentations. In 2017, Geosyntec was invited by U.S. EPA to participate in a focused round table group for two days in Cincinnati from which a special report titled Understanding Elevated Temperatures at MSW Landfills was published by U.S. EPA.

Practice

Geosyntec’s expertise with ETLFs includes the following practices.

  • Best management practices (BMPs): Geosyntec develops guidance documents and site-specific plans to define best BMPs for preventing and reducing the accumulation of heat in landfills through enhanced liquid drainage and gas extraction. 
  • Instrumentation and Monitoring: Geosyntec designs and installs instrumentation, and develops site-specific monitoring programs and techniques to measure temperatures and pressures in landfills.These include fiber optic distributed temperature sensing (FODTS) technology and high temperature vibrating wire piezometers adapted for use in harsh ETLF conditions. Geosyntec produces 3-dimensional models of the landfills for owners and site operations personnel to visualize the spatial temperature and gas/liquid conditions in their landfills.
  • Leachate Management: Geosyntec assists operators with the unique leachate properties and increased quantities of leachate in ETLFs, including leachate treatability, discharge permitting, fee schedule revisions, and design of pumps, lift stations and piping systems. 
  • Legal assistance and expert testimony: Geosyntec provides specialized technical expertise necessary for attorneys and their clients on a wide range of potential legal matters that may be associated at ETLFs such as: consent order negotiations, air enforcement, nuisance odors, cost recovery, and compliance and enforcement.

Publications and Presentations