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
Join SCS Engineers at the Global Waste Management Symposium to learn more, or click these links read about our landfill and landfill gas to energy services, clients, and articles.
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Discovering unexpected pockets of soft soils at the time of construction can delay your project and drive up costs for landfills, support features, and many other types of construction. If you don’t find them, building over them can result in unexpected settlement affecting a structure or building, or cause a slope stability problem for a berm or stockpile. You can avoid both of these scenarios with early investigation and appropriate construction planning.
While landfill development investigations typically require numerous soil borings within the proposed waste limits of the landfill, it’s common to overlook perimeter areas. Pockets of soft soil deposits can be associated with nearby existing wetlands, lakes, or rivers; with wind-blown silt or ancient lake deposits from periods of glaciation; or with fill placed during previous site uses.
The landfill perimeter areas may contain tanks for leachate or fuel, buildings, perimeter berms for screening or landscaping, stockpiles, and other features. A tank or building constructed over soft soils could experience unexpected settlement affecting the performance and value of the structure. The potential for a slope stability problem can increase for a large berm or stockpile built on soft soils.
The first step to avoid these problems and identify problem soils is to include perimeter areas in your subsurface investigation. Perform soil borings or test pit excavations at the locations of the proposed perimeter features such as tanks or berms. If you encounter soft soils, address them like this:
Contact SCS’s geotechnical engineers for more information on how to find and test soft soil areas early in a landfill’s project schedule, so you can effectively address associated construction issues in a way that considers cost and minimizes unexpected project delays.
These grants often target rural areas that don’t necessarily have the support needed to catch up in today’s world of rapid technological advances. A quick Google search shows that at the national level, the USDA offers a Solid Waste Management Grant which may be applied to the cost of program improvements such as landfill evaluations, technical assistance, or training. For this particular grant, any local government, academic institution, or nonprofit servicing an area with fewer than 10,000 people may apply.
This type of funding presents an opportunity for SCS to help address clients’ financial burdens. Awareness of the grants available is a common obstacle, but with some region-specific research, potential project identification, guidance and assistance with grant funding SCS can enhance your arsenal of services.
Here are some places to look for funding:
Contact the authors if you have questions: Ryan Duckett and Quinn Albertson, we’re always happy to help.
Pat Sullivan discusses two case studies that provide examples of two different approaches to odor management. The proactive approach resulted in a more positive outcome than the reactive approach. Although the odor issues never go away completely, the proactive facility has avoided lawsuits and regulatory enforcement and continues to have a positive working relationship with the community.
SCS Engineers freely shares our articles and white papers without imposing on your privacy.
Click to read Part I of this two part series. We’ll let you know when Part II is published soon.
Tuesday, October 10, 1:00 pm – 2:30 pm ET
This Air & Waste Management Association webinar covers the effective, sustainable operation of municipal solid waste (MSW) landfills in today’s changing environment.
The latest updates to EPA regulations in over two decades limiting air emissions from landfills will be reviewed in detail.
Participants will learn the available models for quantifying landfill gas generation emissions and which model to use in different situations as well as energy recovery from landfill gas, its emissions, and how control requirements can affect feasibility.
Christine H. Stokes, a New Jersey Licensed Site Remediation Professional (LSRP) and chemical engineer with 20 years of experience, is now supporting clients out of the SCS Engineers’ New York regional office. Ms. Stokes’ knowledge and experience will ensure a high-level of quality solutions for SCS clients in the New York and New Jersey area.
Ms. Stokes is highly respected by clients, attorneys, and regulatory agencies involved in the environmental industry. For SCS clientele, she will continue her track record of successful project management for environmental sites, including planning and executing remedial investigations for soil and groundwater in addition to vapor intrusion assessments.
She will be responsible for planning, permitting, and conducting remedial actions, including underground storage tank closures and media treatment utilizing in-situ chemical oxidation and bioremediation. In addition, she has expertise with conventional methods such as pump and treat, and soil excavation.
SCS Engineers is known for providing all-inclusive services for contaminated sites undergoing redevelopment. Coupled with Ms. Stokes’ environmental project expertise, she will provide the key strengths respected by clients who appreciate a firm who will meet their performance and technical objectives.
“I am excited to join the SCS team,” said Ms. Stokes. “I see opportunities to support many different clients in both the private and public sectors, including those who require environmental expertise to develop new infrastructure and remediate valuable properties.”
Welcome to SCS, Christine!
Jeopardy question: What is the best way to thaw frozen chocolate?
Chocolate enthusiasts know this and will learn much more at the RETA 2017 National Conference in, where else, Hershey, PA.
The 2017 conference is offering attendees a truly robust program full of a variety of topics, including Technical Sessions in the areas of Compliance, Engineering, Manufacturing & Operations. Hands-On sessions will also be available, as well as Manufacturer Specific Sessions.
SCS Tracer will be welcoming attendees at booth 610, sponsoring Refrigeration Jeopardy, while providing advice and help as they always have. Play Crack the Code and win prizes during the conference. Visit the booth and SCS sessions for hints.
Details here
Your facility will need a Qualified Industrial Stormwater Practioner (QISP) to perform an ERA Level 1 Assessment, on or before October 1, 2017, and follow up with an ERA Level 1 Technical Report by January 1, 2018, or as soon as is practicable. We recommend that this assessment and report be performed prior to the wet season of the 2017-18 permit cycle year, to assist dischargers in reviewing their minimum required BMPs and if needed, implement additional BMPs.
Review your ERA Level 1 Action Plan now. Is it correct given the additional NAL exceedances? You should review all items needed for a successful ERA Level 2 Action Plan and Technical Report to successfully reduce and/or eliminate pollutants of concern in stormwater discharge.
Your facility is required to submit an ERA Level 2 Action Plan, prepared by a QISP, which addresses each Level 2 NAL exceedance via SMARTs. This Action Plan must identify which of the three options below (or a combination thereof) of demonstration(s) the Discharger has selected to perform:
The State Water Board acknowledges that there may be cases where a combination of the demonstrations may be appropriate; therefore a Discharger may combine any of the three demonstration options in their Level 2 ERA Technical Report, when appropriate.
It is important to note that Level 2 is a serious situation under the IGP and you should start working immediately on your stormwater management goals for the ERA Level 2 Action Plan, which is due by January 1, 2018. For the BMP demonstration option, Dischargers may have to implement additional BMPs, which may include physical, structural, or mechanical devices that will reduce and/or eliminate pollutants in stormwater discharge.
The ERA Level 2 Technical Report, which summarizes the option(s) chosen and all relevant technical information, including design storm standards for treatment control BMPs, must be overseen and signed by a California Professional Engineer (PE) and submitted by January 1st, 2019.
Get help now by contacting an SCS Stormwater Professional near you.
Oil and gas processing facilities, federal and local governments, landfills, land developers, contractors, industries with industrial hygiene plans can spend too much money for too little information if they don’t have an understanding of the limits and capabilities of their equipment and methods before the development of their Air Monitoring Plan (AMP) . That’s before considering the risk to their employees and to public health.
Even if you can’t afford a dedicated air monitoring group, you can eliminate the health risks, overwriting a plan, or overburdening your budget. A cost-benefit analysis and integrating stakeholders’ goals can help provide the guidance you need to develop a balanced air monitoring plan.
Start with this list of considerations when developing an Air Monitoring Plan (AMP). The list is followed by tips and suggestions which are helpful under specific circumstances.
Location of the monitoring site is initially dependent on the monitoring objective. For example, once it is known that there is a requirement to monitor for peak ambient H2S at a microscale site, it reduces the monitoring site location to specific areas. Hence, the first task when evaluating a possible site location is to determine the scale for which a candidate location can qualify by considering the following:
1. Location and emissions strengths of nearby sources, especially major source;
2. Prevailing wind direction in the area;
3. Nearby uniformity of land use;
4. Nearby population density.
To select locations according to these criteria, it is necessary to have detailed information on the location of emission sources, the geographical variability of ambient pollutant concentrations, meteorological conditions, and population density. Therefore, selection of the number, locations, and types of sampling stations is a complex process. The variability of sources and their intensities of emissions, terrains, meteorological conditions and demographic features require that each network is developed individually. Thus, selection of the network will be based on the best available evidence and on the experience of the decision team.
Developing an Air Monitoring Plan (AMP) can be a daunting task. There are many decisions to make that have downwind ramifications relative to budget, logistical constraints, and labor requirements. In addition, there may be competing goals in regards to the project stakeholders. SCS has the experience developing and implementing air monitoring plans and systems to meet these challenges; including developing site specific and network-wide AMPs for various monitoring objectives. SCS also understands the costs and demands of the implementation of AMPs on industry and government.
If you need to perform Air Monitoring or are in the initial steps of developing an AMP please contact for expert advice and guidance specific to your region and industry. We have robust programs and experts nationwide. We can also incorporate the use of remote monitoring controls and monitoring by our FCC authorized drones.
Author: Paul Schafer, SCS’ National Expert Ambient Air Monitoring
Thanks to you, our clients, SCS Engineers has received many awards and industry recognitions for research achievements and technology innovations. Engineering News-Record (ENR) recently released the Top 500 Design List, ranking SCS Engineers in the top 100 for the 9th year in a row. In the same publication, SCS is ranked in the Top 10 Sewerage/ Wastewater Firms.
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