We hope you can join SCS Engineers and Dr. Craig Benson, who studies the phenomenon, to our free, non-commercial webinar entitled “Identifying and Managing Elevated Temperature Landfills.”
At this session, you’ll get an update on the knowns and unknowns of ETLF conditions.
Our ETLF session is for landfill owners, operators, technicians, field personnel, engineers, and regulators interested in learning about the latest research and mitigation strategies from the foremost experts in the field.
We encourage audience engagement with our panelists. We provide the ability to ask questions anonymously. We respect and understand your time constraints; those unable to stay on the live session will automatically receive a link to a recording.
ETLF Field Tips:
SCS OM&M teams look for these signs in the field data collected:
ETLF Webinar Description: The generation of heat in a municipal solid waste (MSW) landfill is normal as microorganisms break down waste; however, Elevated Temperature Landfills (ETLFs) exhibit temperatures above regulatory thresholds due to abnormal chemical reactions within the waste mass. These reactions can cause changes in landfill gas composition, create odors, cause rapid and severe waste settlement, and generate leachate seeps and outbreaks. All of these issues add expensive costs to managing the facility, and that’s where this team can help.
Please join SCS Engineers for our live ETLF webinar. We welcome Dr. Craig Benson, who studies the phenomenon, and our solid waste and field engineers, who bring their expertise for an engaging presentation. This ETLF session is suitable for landfill owners, operators, technicians, field personnel, engineers, and regulators interested in learning more and would like to engage with some of the foremost experts in the field.
LEARN MORE AND RSVP HERE FOR THE FREE ETLF WEBINAR
Now On-Demand! Identifying and Managing Elevated Temperature Landfills
ETLFs are landfills where gas wells exhibit elevated temperatures (> 131 oF) over an extended landfill area that are atypical of temperatures commonly associated with methanogenic biological waste degradation. Approximately 20 ETLFs have been encountered in North America, some with in-situ waste temperatures approaching 300 °F.
If you could not join us, we hope you will find value in this SCS Engineers’ interactive webinar about ETLFs. We welcome Dr. Craig Benson, who studies the phenomenon, and our expert solid waste and field engineers, who bring their expertise for a more rounded presentation.
Who Should Attend and What You’ll Learn?
At this session, you’ll get an update on the knowns and unknowns of ETLF conditions.
Our ETLF session is for landfill owners, operators, technicians, field personnel, engineers, and regulators interested in learning more and would like to engage with some of the foremost experts in the field.
SCS’s forums are educational, non-commercial webinars with a Q&A forum throughout; they are free and open to all who want to learn more about landfill operations and technology.
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EREF, the Ohio EPA, and industry leaders will discuss the latest science, factors, and best practices around landfill instability. This session will include managing liquids and leachate and the practice of aqueous waste disposal in landfills.
The Summit will take place at the Marriott Columbus University Area in Columbus, Ohio, on September 1, 2021. As with many EREF events, this will likely fill to capacity quickly.
SCS Engineers President and CEO Jim Walsh will moderate the Elevated Temperature Landfills session. This informative session will include mechanisms contributing to elevated temperatures, modeling to predict and control those conditions, and monitoring and management. Mr. Walsh is well-regarded for his expertise with ETLF conditions. His firm, SCS Engineers, produces the technology used to monitor and manage over one-third of the landfills in the U.S., alerting operators of landfill conditions 24/7 in real-time.
About Jim Walsh: He is one of SCS’s National Experts on Elevated Temperature Landfills working at the forefront of sustainable solid waste management, sanitary landfills, and landfill gas (LFG) for more than 40 years. Mr. Walsh earned recognition as the Principal Investigator or Chief Engineer on over thirty dedicated landfill fire and elevated temperature landfill projects. He regularly guides landfill operators and the solid waste industry on how to avoid landfill fires. He has investigated landfill fires in-situ and developed management and mitigation programs to address landfill fires and related events when they do occur. He served on the Ohio EPA Committee to address landfill fires and elevated temperature landfills in the state and assisted in developing the Ohio EPA Guidance Document on the subject.
Landfill operators have known about elevated temperature conditions in landfills for nearly a decade. Some operators have already incurred numerous expenses to control adverse environmental and operational issues at these landfills, and some operators have set aside large amounts of money in their books to address future liabilities associated with such landfills. Due to the complexities of controlling elevated temperature conditions and the compliance issues arising from such conditions, it can force operators to temporarily, or permanently close their landfills.
Can design address elevated temperature conditions?
The operators of larger landfills have been monitoring and analyzing data to identify triggering factors, while others continue controlling the environmental impacts. Environmental Research & Education Foundation (EREF) initiated several research projects to identify the triggering factors with the excellent scientific work of highly qualified researchers. These are on-going projects.
In the meanwhile, operators of larger landfills are developing strategies, basing strategic-decisions on the data and conditions collected during operations over long periods. After analyses, they have the means to reduce the impacts by making changes in their operations and landfill designs. The most effective changes include eliminating certain waste types from the waste stream and improving the movement of liquid and gas through the waste column with new designs.
Are design innovations consistently implemented?
The pioneering designs feature preventative measures, intending to avert the formation of elevated temperature conditions in future disposal cells. Implementing these new design features requires careful consideration and functional analyses, as some of the recommendations can be costly, affecting the bottom line. The urgency in controlling compliance issues associated with elevated temperatures and the associated financial impacts of such conditions objectively prescribe that local managers work closely with their designers and field expertise to bring non-compliance issues under control.
Is this an executive risk management strategy?
Until the on-going research more clearly identifies the triggering factors and the means to prevent the development of elevated temperature conditions, it seems logical to invest in implementing preventative measures that are currently available. When more research results are accessible, then the local managers will be able to make decisions that are even more informed. Those wanting to address the likelihood of future liabilities proactively will need executive-level funding and superior technical support, all of which are possible.
Is there much sharing of newer designs and strategies within the solid waste industry?
Yes, there is a fair amount of collaboration among the technical community and within solid waste associations. Most operators share their preventative designs within the engineering community and help contribute to funded research. Their actions and results will help to strengthen an industry application until such time that research results and the means to prevent the development of elevated temperature conditions are well understood. We all know that progress in technology and science depends on sharing new knowledge.
Let’s continue with the combination of serious research, innovative designs, proactive operational changes, and sharing knowledge among our industry professionals that will lead to more precise solutions in the near future. Here are a few resources available now:
About the Author: Ali Khatami, Ph.D., PE, LEP, CGC, is a Project Director and a Vice President of SCS Engineers. He is also our National Expert for Elevated Temperature Landfills, plus Landfill Design and Construction Quality Assurance. He has nearly 40 years of research and professional experience in mechanical, structural, and civil engineering.
Learn more at Elevated Temperature Landfills
Heat generation in landfills is a natural phenomenon. It happens in every landfill to a degree. Heat generation in landfills accepting organic matter occurs to a higher degree due to organic material biological degradation. Subtitle D landfills accepting organic matter also accept other types of materials that can chemically react under specific conditions to generate additional heat through exothermic reactions.
Recent experience has shown that deep landfills with high levels of organic matter and high levels of moisture in the waste column can potentially create conditions deep within the landfill so that the heat generated cannot escape from the landfill boundaries fast enough. As a result, heat accumulates in the landfill and creates the condition known as elevated temperature landfill or ETLF.
The accumulation of heat causes rising temperatures within the landfill that can adversely affect the beneficial biological degradation of organic waste. Beneficial degradation of organic matter generates methane that is captured by the landfill gas control and collection system (GCCS) and in many instances converted to energy through highly technologically sophisticated systems.
Adversely affected biological degradation of organic waste under high-temperature conditions causes significant increases in the generation of carbon dioxide, hydrogen, and other gasses that have no economic value and can cause other environmental challenges, including regulatory compliance and increased public scrutiny. Additionally, control systems placed in service to address conditions resulting from elevated temperatures can be costly.
If you manage a deep and wet landfill with significant organic matter in your waste stream, you should consider design and operational steps to mitigate future operational and compliance challenges. These might include new engineered features to enhance liquids, gas, and heat removal from the deeper parts of the landfill. Many of the major landfill companies are currently designing and constructing systems to expedite the movement of water and gas through the waste column, which is a great help to potentially minimizing heat accumulations in the landfill.
Significant research work is currently underway to find out causes of heat accumulation in landfills, but it may take years before accurate cause and effect of such complex and inter-relating processes are more clearly determined, and solutions developed. Heat removal by landfill gas and leachate takes place on a regular basis, but the quantities are insignificant to affect a major reduction in accumulated heat in the landfill.
SCS is an expert in the management of elevated temperature landfills and has been promoting the development of heat management systems over the past several years. As a result, we are highly qualified to address heat accumulation in landfills and development of heat removal systems to control temperatures below the landfill surface. If you have an elevated temperature landfill at your facility or a landfill that seems to be progressing in the direction of becoming an elevated temperature landfill in the future, contact us and let us review field data from your facility and develop means to control temperatures below the landfill surface.
Author: Ali Khatami, PhD, PE, LEP, CGC, is a project director and a vice president of SCS Engineers. He is also our National Expert for Landfill Design and Construction Quality Assurance. He has nearly 40 years of research and professional experience in mechanical, structural, and civil engineering.
Typical Conditions
The organic matter that is placed in landfills goes through a decomposition process that is exothermic and releases heat inside the landfill space. There are also other exothermic processes such as metal corrosion, hydration, carbonation, and acid-base neutralization that contribute to the heat generation phenomenon in landfills. Municipal solid waste has a relatively low heat conductivity characteristic, which means the heat is not as easily conducted through the waste keeping the landfill interior generally warmer than the areas near the landfill exterior.
Landfills expel the heat in different ways; propagating through the waste mass to the air, ground, leachate, and gas heat sinks. The heat escapes the landfill at its boundaries by convection to the air above the landfill surface and by conduction to the ground below the waste. Heat can also escape from landfills through liquids and gases removed from the landfill. For example, by conduction, via leachate that flows through the waste and is removed by leachate sumps and by convection, and via gases generated inside the landfill that are removed through the gas collection system.
Special Conditions
The large majority of landfills in the country show no signs of special conditions indicating too much heat. The characteristics noted in this blog have been observed in a few large, deep, wet landfills. Field investigations at landfills with high temperatures revealed that the highest temperatures are generally located at mid-point to the two-thirds depth of waste from the top surface. Temperatures as high as 250 °F have been recorded by specialized measuring devices.
Under certain conditions, elevated temperatures may occur inside a landfill, and the excess heat changes the character of chemical reactions taking place in the landfill, such as the decomposition process of the organic matter. Other documented changes that may take place in accumulated heat conditions are: leachate becoming stronger with higher BOD, lower pH, higher carboxylic acids and salts; concentrations of certain acids increasing; carbon dioxide and carbon monoxide generation increasing; the ratio of methane to carbon dioxide decreasing; hydrogen generation increasing; landfill odors changing to a significantly pungent character; landfill settlement rates increasing; gas generation and gas pressure increasing; leachate generation increasing; along with other changes.
Research
Heat generation in landfills is studied by researchers, reported in technical literature and scientific papers by academia and the industry. A summary of the findings related to the amount of heat generated from municipal solid waste in landfills is presented in Table 1 of Heat Generation in Municipal Solid Waste Landfills posted on the California Polytechnic State University, Robert E. Kennedy Library website.
Since the issue of high temperatures in landfills is of extreme importance to landfill operators with respect to compliance, operations, and financial aspects of these cases, finding out the cause and sources of excess heat is a hot subject in the field of landfill science. The largest research grant supporting the on-going research in this field was awarded by the Environmental Research & Education Foundation (EREF) in December 2014. So far, three parts of a technical article explaining chemical mechanisms through which organic matter decomposes and generate various types of other chemicals and heat have been published by the researchers of the above grant in Waste360. The research is on-going, and more information will be published in future. Links to the first three parts of the above article are provided here:
Prevention, Diagnosing and Managing ETLFs
SCS was involved in the preparation of standards for large, deep and wet landfills for a major waste operator in 2016. The intent of the standards is to implement measures to prevent elevated temperature conditions in large, deep, and wet landfills. SCS’s experience at such landfills and its in-depth knowledge can be valuable to those waste operators who are either experiencing elevated temperature conditions in their landfills or want to prevent conditions forming in their landfills proactively.
About the Author: Dr. Ali Khatami
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