Elevated Temperature Landfills (ETLFs) 

This page serves as a resource for current research and data regarding elevated temperature landfills (ETLFs) from topic experts.
Details found here are based on on-going research from experts in the solid waste industry and are intended
to educate the public on ETLFs.

EREF is a non-advocating, independent 501(c)3 class non-profit whose mission is to fund and direct scientific research and educational initiatives for the betterment of the solid waste industry. As such, data and additional resources listed here do not reflect a bias or advocacy position on behalf of EREF.

EREF-Funded Research and Articles on Elevated Temperature Landfills

Comparative Microbiology of Typical and Elevated Temperature Landfills
Investigator: University of Illinois Chicago

Background: While the basic microbial processes of anaerobic decomposition in landfills have been well-known for decades, studies of microbial diversity using modern sequencing technologies, which make it possible to cheaply and efficiently catalog microbial diversity, are rare. The goal of this EREF-funded project is to aid in the determination of the causes and indications of elevated temperature landfill development, towards distinguishing between biotic and abiotic processes responsible.

Learn more about this project.

Understanding and Predicting Temperatures in Municipal Solid Waste Landfills
Investigators: University of Virginia, North Carolina State University, City College of New York, Geosyntec Consultants

Background: While there are a number of landfills in North America that are experiencing elevated temperatures, there is only anecdotal evidence as to the underlying cause. Some of these elevated temperature landfills have received industrial wastes that are known to release heat, but others have not. Some elevated temperature landfills are deeper and wetter than average, but others are not. Elevated temperatures have posed regulatory challenges, and in several cases have resulted in costly operations and management, pressure to initiate uncertain remedial actions, and litigation associated with off-site migration of gases and odors caused by elevated temperatures.

Learn more about this project.

“Diagnosing and Understanding Elevated Temperature Landfills”
Article originally published on Waste360.com

In a 3-part series entitled “Diagnosing and Understanding Elevated Temperature Landfills,” researchers Morton Barlaz, Craig Benson, Marco Castaldi, and Scott Luettich discuss chemical and biological reactions that take place within ETLFs as well their characteristics and the challenges landfill owners face. Links below will redirect to Waste360.com where the articles appeared.

Part 1: Characteristics and challenges associated with ETLFs and their management

Part 2: Biological reactions

Part 3: Chemical reactions

FAQs

The National Waste & Recycling Association has compiled a list of commonly asked questions and FAQ’s regarding elevated temperature landfills.

To view the PDF, click here.

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Additional Resources

The following five presentations were made at the 2016 Global Waste Management Summit presenting the latest findings from research currently underway. To access these presentations, click the links at the bottom of each summary. Access to abstracts from the Global Waste Management Symposium has been provided by Waste360.

Changes in Landfill Gas Composition
Navid Jafari – Louisiana State University
Timothy Stark – University of Illinois, Urbana-Champaign
Todd Thalhamer – California EPA

Summary of Findings:

(1) Changes in landfill gas composition, which are characterized by decreasing ratio of CH4 to CO2 flow rate ratios and elevated carbon monoxide and hydrogen levels (gas composition is found to advance in front of the elevated temperature region);

(2) Increased odors;

(3) Elevated waste and gas temperatures, e.g., wellhead temperatures increased from below the NSPS threshold of 55°C to 90°C;

(4) Elevated gas and leachate pressures that cause leachate outbreaks;

(5) Increased leachate volume and migration;

(6) Slope movement; and,

(7) Unusual and rapid settlement.

Click here to view the completed article.

Developing an Understanding of Pyrolytic Reactions in MSW Landfills
Marco Castaldi – City College, City University of New York
Joel Ducoste – NC State University
Morton Barlaz – NC State University
Craig Benson – University of Virginia
Scott Leuttich – Geosyntech Consultants

Summary of Findings:

The complex reaction sequence occurring within the landfill environment is affected by multiple factors ranging from heterogeneity of the waste mass to changing conditions within the landfill. The time dependent evolution of intermediates and some non-equilibrated final products must be known, and can only be properly modeled using a kinetic reaction sequence. The question then becomes; how detailed a reaction sequence is required to enable accurate representation of events occurring without unnecessary acquisition of large and detailed data sets? To answer this question we began to investigate the likely reactions that will occur in an oxygen deficient environment (i.e. pyrolysis) and couple the results to the overall fluid and heat flow throughout the landfill.

Pyrolysis is a complex process influenced by several parameters (e.g., waste composition, moisture content, temperature) that directly affect the yields and characteristics of the products obtained. One poorly understood aspect of pyrolysis is the actual energy change that occurs during the process.. Unfortunately, reports of the thermal effects of pyrolysis reactions vary widely, ranging from exothermic to endothermic under similar conditions. Furthermore, the exothermic-endothermic variation is observed over a range of conditions.

Since cellulose is the dominant organic compound by mass in landfills, an understanding of reactions based on biomass will be used as the starting point for describing thermal reactions in landfills. An engineering model based on available literature data was presented to demonstrate the possible conditions leading to elevated landfill temperature events.

Click here to view the completed article.

Understanding and Predicting Temperatures in Municipal Solid Waste Landfills
Morton Barlaz – NC State University
Joel Ducoste – NC State University
Craig Benson – University of Virginia
Marco Castaldi – City College, City University of New York
Scott Leuttich – Geosyntech Consultants

Summary of Research:

Research has been initiated to (1) develop an understanding of the mechanisms that cause heat generation and result in heat accumulation in landfills, and (2) develop a quantitative framework to predict temperatures within landfills. The objective of this presentation is to describe the governing equations and modeling approach that will be used to model the generation and release of heat in landfills including the processes illustrated in Figure 1.

Figure 1

Click here to view the completed article.

Heat Extraction from an MSW Landfill
Brian Power – Republic Services
Michael Beaudoin – Republic Services
Peter Carey – PJ Carey
Aaron Karlas – Feezor Engineering

Summary of Findings:

A closed-loop fluid cooling element system pilot program is underway at a closed municipal waste landfill (MSW) facility. The program has demonstrated that it is possible to remove substantial heat from a waste mass and that significant waste temperature reductions can be achieved within a limited distance from the heat extraction point.

Using the results of the pilot study, it has been estimated that a series of heat extraction points placed on approximately 15-foot centers would be able to arrest the migration of a 300º F heat front by creating a lower in situ waste temperature zone at 175º F and then hold that temperature “line-in-the-sand” to create a long-term thermal barrier.

Click here to view the completed article.

A Potential Heat Generation Process in MSW Landfills with Elevated Temperatures
Henry Kerfoot – Civil & Environmental Consultants, Inc.
Michael Beaudoin – Republic Services

Summary of Findings:

Cellulose dehydration as a component of hydrothermal carbonization, along with secondary reactions, can explain the preponderance of symptoms commonly observed at elevated-temperature MSW landfills. While this is strictly a hypothesis, we believe that it merits additional attention and research as the solid waste industry continues to evaluate the potential causes, assess potential remedial strategies, and identify potential preventative measures.

Click here to view the completed article.

Citations for Additional Resources

Benson, C. (2017), Characteristics of Gas and Leachate at an Elevated Temperature Landfill, Geotechnical Frontiers 2017, Waste Containment, Barriers, Remediation, and Sustainable Geoengineering, GSP No. 276, ASCE, T. Brandon and R. Valentine, eds., 313-322.

Hao, Z., Sun, M., Ducoste, J. J., Benson, C. H., Luettich, S., Castaldi, M. J. and M. A. Barlaz, 2017, “Heat Generation and Accumulation in Municipal Solid Waste Landfills,” accepted, Environmental Science and Technology, DOI: 10.1021/acs.est.7b01844.

Stony Hollow Landfill

Stony Hollow Landfill, located in Montgomery County, Ohio, was cited for strong odors emanating from the landfill due to elevated temperatures. Action has since been taken to reduce the odor and control the higher temperatures.

Learn more about the Stony Hollow Landfill and the steps being taken to resolve the issue here: http://stonyhollowlandfill.com/

EREF is a 501(c)3 class charity that funds and directs scientific research and educational initiatives for waste
management practices to benefit industry participants and the communities they serve.