
SCS Engineers periodically prepares SCS Technical Bulletins – short, clear summaries of U.S. Environmental Protection Agency (EPA) rules and plans. On May 21, 2021, the EPA published a Federal Plan to implement the new Emission Guideline (EG) rule for municipal solid waste (MSW) landfills. The Federal Plan is published under Title 40 of the Code of Federal Regulations (CFR) Part 62, Subpart OOO.
Read, share, download the Federal Plan for Landfill EG Rule Tech Bulletin here.
It goes without saying: landfill operators are forever working to stay on top of odors, especially when the community smells something and points to the landfill or when regulators come calling. This blog shares two odor stories: one around landfill gas and another around trash. Then it looks at what happened when an operator got a permit restriction over alleged hydrogen sulfide emissions; odor was not the problem here. It was a perceived health risk; learn how SCS proved a predictive model was off the mark.
Is Landfill Gas a Source of Community Odors? And Ensuring Compliance
Living up to landfill odor nuisance standards is tough. The underlying premise is that odors must limit peoples’ ability to enjoy life or property to create a public nuisance, but it’s a subjective call. How strong an odor is and sometimes even if it exists depends on perception, so the question becomes: when they aren’t sure what they are being measured against, how do operators comply and prove compliance?
SCS recently helped a client figure out how to accomplish this after receiving odor complaints from the community, ultimately leading to a state agency-issued violation.
“We needed to thoroughly investigate to identify and mitigate odors, then prove compliance to the state regulator. Making a strong, valid case without having a numeric standard to go by takes both creativity and a scientific approach,” says Pat Sullivan, SCS senior vice president.
Sullivan, a biologist and his team of meteorologists, air dispersion modelers, and engineers, had a good starting point. They knew landfill gas was the source of the problem. But they needed more data to get to the root of that problem, and the operator’s required surface monitoring did not tell enough of the story.
The team launched a series of studies relying on multiple investigative tools.
“When we may have to put in more gas collection components, as we did here, we want to be sure we install them exactly where they are needed. This entails going above and beyond the standard modeling with a more rigorous methodology to get a comprehensive landfill gas emissions footprint,” Sullivan says.
SCS began by bringing out a drone to reach more landfill areas than technicians on foot for better coverage. The drone can fly over slopes, areas too dangerous to walk due to constant movement of heavy equipment, and areas inaccessible because of snow and ice. As it flies, it shoots a laser, which identifies methane based on the light refraction by methane molecules—then incorporates the data into a map for a comprehensive, visual picture.
Knowing methane concentrations at specific locations is important, but determining where to be more vigilant in controlling landfill gas also requires knowing hydrogen sulfide (H2S) concentrations. Sometimes overall methane levels are within acceptable limits, but the hydrogen sulfide in it is elevated, which could be a problem, Sullivan explains.
Getting a good grasp on H2S’s potential impact is tricky, as levels can vary radically from one area of the landfill to another. Pat Sullivan, SCS senior vice president, has seen them range from 100 parts per million to as high as 100,000 at different locations.
SCS used a Jerome meter, a highly sensitive tool that precisely quantifies H2S down to low-level part per million levels. SCS took it across the landfill and then into the community in search of H2S hot spots.
At the same time that the team investigated surface emissions of H2S, they went deeper down, sampling each landfill gas extraction well for levels of this volatile sulfur compound to identify potentially problematic spots within the landfill gas system.
“For this, we used Dräger sampling tubes, a resourceful tool in that rather than sending 100 samples to the lab, we analyze them ourselves and get immediate results,” Sullivan says.
Technicians get accurate quantitative results within plus or minus about 20% and can view concentration readings out in the field. Results are recorded on field logs and entered into a database for future analysis.
SCS overlaid the methane data from the drone study with the H2S data on both surface emissions and wells to develop a roadmap to design a landfill gas system upgrade. It includes new wells and piping in focused areas and more blowers for increasing the vacuum to pull more gas.
“We saw immediate results,” Sullivan says.
“Total gas collected went up 15 to 20 percent. Complaints went down significantly, and our client has not received another violation since.”
Of course, as the landfill takes in more trash, it will generate more gas, so due diligence is ongoing.
“Problem-solving is a phased approach. You do what you determine to be most effective; evaluate; then do additional work to improve. We will continue to follow this site and fine-tune where needed to keep the system running efficiently and keep the community and regulators happy,” Sullivan says.
Taking Down Landfill Odors from Trash
New garbage on a landfill’s active face can be a source of offsite odors, but determining if the waste facility is responsible, and determining when, where, and how odors travel, takes forensic work. Landfill odor experts rely on multiple data sets and tools to understand what can be complex issues and ultimately devise the most effective odor mitigation program when necessary.
In a couple of recent scenarios in Southern California, SCS combined complaint data, meteorological data, and smoke studies to get a full picture that verified the decomposing waste was the odor source. Then staff helped nail down specific times the problem occurred and under what conditions; providing a concise window can save operators labor and other resources because they can execute proactive measures only when needed.
“We look at complaint data to learn the location, day, and time of the complaint, but these accounts are not reliable by themselves. So, we overlay this information with meteorological data to determine the wind conditions during those days and times. Weather-related data is important in vetting offsite odors because if the landfill is not upwind of the location when the complaints happen, there likely is another source,” says Pat Sullivan, SCS senior vice president.
Sullivan and his team begin their investigations in two possible ways – setting up meteorological stations at strategic areas on the landfill to capture wind-related data or capturing data from already situated stations. Then they produce wind roses from their findings, which graphically represent wind speed; how often the wind blows from certain directions; and how these two correlate. In these two scenarios, graphing wind data times during each day helped determine exactly when specific wind conditions are prevalent.
In one of the two cases, odors occurred in the summer and almost always in the morning. The data not only showed where the winds were coming from at those times, but also showed they were traveling at low to moderate speeds.
“We matched that information to complaints and confirmed that the wind conditions were indeed driving the odors,” Sullivan says, explaining the speeds were just enough to carry the odor molecules into the community but not high enough to disperse and dilute them.
“Now we have painted a picture of wind conditions that we can focus on to get more information. We are getting closer to designing a multi-tiered odor mitigation program,” he says.
The next step was a smoke study, which reveals how odors move offsite, identifying the exact pathways and movement trajectory. These details are important because to treat or disrupt odor molecules; operators need to intersect the odor plume before it leaves the site.
SCS odor experts release colored smoke at the time and location they believe odors are, based on the meteorological data. They film from a drone to get a bird’s eye view of the smoke plume as well as get a camera filming from a different angle, following the plume movement to identify its path out of the landfill. This method enables them to determine where to intersect the odors as they move through the air before leaving the site.
From this research came three recommended measures to take during unfavorable wind conditions:
One of the landfill operators now has the problem under control and has received no further violations.
The other site made many of the same changes and plans to open a second disposal area for smelly loads. This client has seen a significant reduction in complaints and violations, but it’s a work in progress. The next true test will come when Sullivan and his team reevaluate in the summer.
“We will see then if any improvements are needed and tweak the solution if needed.”
And as with our other clients, we are training operators on how to be proactive. We teach them how to identify and grade odors and how to follow set procedures. And we help them with strategy implementation,” he says.
Odor mitigation is an ongoing undertaking. The team continually assesses and quantifies emissions and potential impacts.
“We look for changes that will control odors or prevent them in the first place. And we provide clients with the know-how and support to stay ahead today and into the future. Landfills and waste volumes are growing and changing. It’s a dynamic scenario. And we continue to build on what we have proven and adjust to keep up to make more progress,” Sullivan says.
Showing That a Model Can Over Predict H2S Emissions
Hydrogen sulfide (H2S) can be problematic even at very low concentrations, so this volatile sulfur compound is on federal, state, and local regulators’ radar. Some jurisdictions require the evaluation of air toxic emissions to determine potential health impacts to nearby communities.
They are also calling for these evaluations during permitting or to decide when controls are needed. To make these impact determinations, regulators typically rely on standard H2S risk assessments leveraging air dispersion modeling that predicts concentrations at locations away from the source.
However, this methodology, which includes estimates of emissions and predicts offsite concentrations based on algorithms that mimic how air moves, is not always accurate. Inaccuracy proved to be the case at one SCS client’s site. The model overpredicted offsite measurements of H2S that the state and local agency classifies as toxic.
Ultimately, the client entered into an enforcement agreement with the state because the operator had a permit limit, based on results of the risk assessment that it could not meet.
“Respectfully, the agency came in maintaining that the levels were out of compliance; it came as a surprise and seemed questionable to our team given our experience. We felt that the air modeling and risk assessment results derived from this modeling were not accurate,” says Sullivan.
First, his team tried to adjust model inputs and variables that would yield what they believed would be more accurate data. Even though they could show improvements, the model adjustments could not obtain readings that showed compliance with the risk-based limits.
Next, they began going out monthly and measuring real concentrations at receptor locations. The team used a Jerome sensor, a highly sensitive handheld device that detects H2S down to single-digit parts per billion levels with good accuracy.
When they compared the predictions from the standard model to their readings on the same days of each month and same times of day, they confirmed the concentrations were well below the acceptable risk threshold.
“Because we did this over an extended period, we have continuous readings and a large data set from many locations that give a history and statistical validity,” Sullivan says. Every monitored value was substantially lower than the values predicted by the model.
“What that means is we could show that while there were onsite emissions, they were not escaping the landfill at levels that would exceed risk-based thresholds. That was useful in proving to the regulators that the landfill was actually in compliance with the standard, even when the model suggested it was not,” Sullivan says.
Now SCS is asking for revising its client’s permit and that the limitations are made more flexible based on real-time, longer-term findings. While the team is still waiting on the final permit decision, they’re confident they have proof that the site complies with the risk-based limit.
The outcome of this project has potential beyond possibly changing one permit for one operator, Sullivan surmises.
“We think the data developed from this study showing how the models can overestimate real-world conditions can ideally help other operators build a sound case in circumstances where they truly are in compliance.”
Related Resources
Staying Ahead of Odor Management at Solid Waste Facilities – This video recording is from a live session about the challenges of odors, including measuring them and the science behind them. Throughout the recording, the speakers’ field questions as they make recommendations for assessing and avoiding odors, regulatory issues, litigation, and responding to complaints.
The presentation and Q&A run for 1 hour 41 min. It’s well worth your time, with plenty of questions posed by solid waste facility operators, landfill managers, and composting operators answered.
SCS Engineers encourages you to share this video or any from our Learning Center. You can embed them at events and use them for in-house training. Look for our
(40 CFR Part 60, Subpart OOO)
EPA is submitting a pre-publication copy of the final MSW Landfills Federal Plan to implement the Emission Guidelines (EG) and Compliance Times issued on May 10, 2021. The Final Plan becomes effective 30 days after publication in the Federal Register, impacting any remaining landfills without approved EG Cf rules.
EPA’s federal plan includes an inventory of designated facilities and an estimate of emissions from those designated facilities. The Agency estimates 1,590 landfills will potentially be covered in 42 states and the US territories of Puerto Rico and the Virgin Islands, and one tribal entity.
SCS Engineers is preparing a Technical Bulletin for distribution to our mailing list and on social media. The Bulletin will consolidate 133 pages into several pages highlighting significant dates and impacts for you.
Affected are MSW landfills that commenced construction on or before July 17, 2014, and have not been modified or reconstructed since July 17, 2014.
EPA is implementing emission guideline requirements for existing MSW landfills located in states and Indian country where state plans or tribal plans are not currently in effect because they were not submitted or approved.
The Final 2016 Emission Guidelines for MSW Landfills require existing landfills that reach a landfill gas emissions threshold of 34 metric tons of nonmethane organic compounds (NMOC) or more per year to install a system to collect and control landfill gas (GCCS).
It also implements the emission limits, compliance schedules, testing, monitoring, reporting and recordkeeping requirements established in the Emission Guidelines for MSW Landfills.
Unless the landfill is a legacy controlled landfill, owners or operators of MSW landfills subject to the MSW Landfills Federal Plan must submit a design capacity report within 90 days after the effective date of the Federal plan (40 CFR 62.16724(a)).
Should the design capacity report indicate a capacity equal to or greater than 2.5 million Mg and 2.5 million m3 of solid waste a landfill can accept; then, an annual NMOC emission rate report must also be submitted within 90 days after the effective date of the Federal plan, and then every 12 months until the landfill installs a GCCS (40 CFR 62.16724(c)).
You may find a copy here on EPA’s website.
Contact your SCS project manager or for assistance. Follow us on Twitter, LinkedIn, or Facebook to receive EPA alerts and SCS Technical Bulletins, along with other news.
SCS Engineers, a top-tier ENR environmental consulting and construction firm, welcomes Professional Engineer Mary Kennamer to its environmental services team in Raleigh, N.C. As a Senior Project Professional, Mary is responsible for designing and engineering solutions to help landfills, manufacturers, and businesses comply with federal and state environmental regulations.

As a chemical engineer, Mary’s background and degree are useful to help North Carolina landfill owners prepare to meet more stringent federal and local air regulations. She will advise on air compliance issues, air permitting, compliance reporting, and consulting for landfills and manufacturing.
“Mary’s previous consulting experience and work with the US EPA is a tremendous asset and value for our landfill and manufacturing clients,” states Kenton Yang, the Raleigh office’s project director. “We’re excited to add another bright star to the Raleigh office.”
In order to permit new or expanding plants and facilities, there are complex environmental policies to meet. As an environmental and chemical engineer, Mary researches, plans, and completes the technical work for air permitting and compliance, SPCC, and due diligence that keeps owners in compliance and projects moving forward.
About SCS Engineers
SCS Engineers’ environmental solutions and technology directly result from our experience and dedication to solid waste management and other industries responsible for safeguarding the environment. For more information about SCS, please visit our website at www.scsengineers.com/, contact , follow us on your preferred social media, or watch our 50th Anniversary video.
SCS Engineers – Raleigh specializes in permitting and meeting comprehensive clean air, water, and soil goals and provides a range of services such as PFAS treatment, solid waste master planning, landfill technology, risk management, groundwater monitoring, pre-closure and landfill closures, and Brownfields remediation.
When Doug Doerr got a call from a Colorado-based landfill operator with a hot gas probe at his site’s boundary, Doerr’s day kicked into high gear. Chasing down gas migration problems is nothing new in an SCS client manager’s life, but that reality makes the job no less complex. And in this scenario, he was dealing with a site that he occasionally got called to visit, so to understand the problem fast, he needed the site’s historical data and the current information to fully picture what was happening.
Doerr started with basic landfill gas information from the client: the monitoring probe’s location and a drawing of the gas collection system to determine where the probe was in relation to the gas system. But as you know, that is one small slice of a king-sized pie.

“I queried our in-house landfill gas technical group (engineers, geotechnical experts, and field personnel). And got over 25 responses within several hours with suggestions, one of which came from Ken Brynda in SCS Field Services, who leveraged DataServices to help me identify and narrow down the potential cause of the problem,” recalls Doerr.
DataServices, a module of the SCS eTools® digital platform, collects, stores, manages and analyzes large volumes of continuously accumulating landfill gas data for individual sites or multiple landfills. The module provides a quick method to view landfill gas scenarios.
The beauty of it is that it generates maps and charts to visualize every well and every probe. These system components are viewed in relation to one another and in relation to the perimeter, where the methane on that Colorado site flowed. Further, SCS Field Services’ landfill gas gurus, such as Ken Brynda, plug-in specific parameters that keep a close watch on any well or a group of wells.

As responders viewed initial results from their respective bases around the country, Brynda churned out more information in a few hours, running point charts to capture the balance gas, methane, flow, temperature, supply vacuum, and the vacuum applied to each well. He looked for trends that narrow down cause and point to solutions.
Eliminating the Possibilities – Rule Out Well System Malfunctions
“It can take days if we’d had to do it the old school way with spreadsheets laid out in a lot of rows. But we could identify the potential problem in a matter of hours, backed by a comprehensive evaluation for the landfill operator in eight hours,” Doerr says.
When Field Services staff work to solve a problem with a probe, they look for an outlier, something from a group of wells that’s not behaving like the other wells. In this case, Brynda determined that the wells near the hot probe were functioning properly. DataServices eliminated potential problems by slicing through and analyzing large chunks of data confirming the system was working efficiently.
Next, we observed that the wells are likely too far away to pull gas back from waste, adjacent to the probe in question, where there are no wells.
“DataServices helped rule out malfunctions, and that’s a big deal because if you can confirm the landfill system is working properly, you have narrowed your focus and can look toward other possibilities, ultimately leading to corrective options,” Doerr says. Brynda and Doerr suggested putting in temporary wells in that area to avoid odor migration and health and safety issues.
Doerr continues watching the situation and is prepared with a several-point action plan to mitigate exceedances and avoid falling out of compliance. “We continue watching the data to ensure the gas collection system continues to function well. Should there be issues again, we’re able to fully identify the gas migration pathways and anything in the system that looks out of the ordinary,” Doerr says.
If the client decides to add wells in time, data from the expanded infrastructure will be added to the app and monitored. “As the number of wells grows, DataServices grows with it, adding any, and as much, monitoring and collection data as the operator wants. DataServices will always be in the background to monitor, collect and analyze LFG data in real-time, whenever we need it,” he says. Being able to store, organize, dissect and analyze unlimited volumes of information from one location is powerful. And not just because it helps operators identify problems as they are happening, but because it and our teams can support them in looking for trends over time. Keeping an eye on the activities that keep the systems in balance is less costly.
For Doerr, who spends time in the field but longer hours with his clients, DataServices and the ability to interact quickly with experts like Brynda help SCS deliver more value to clients. “As much as I’d love to master DataServices, I need to focus all of my time on my clients’ business and goals; having support from Field Services and DataServices makes us all more efficient.”
Landfill Technologies and Comprehensive Expertise
SCS eTools® and SCS DataServices®, now with SCS MobileTools® for viewing data and charts anywhere; available to pull landfill data into DataServices for analyzing. You can customize and focus on exactly what you need fast. As Doug and Ken emphasize, it’s info that you likely already have, but may not be able to use quickly for troubleshooting.
SCS RMC®, remote monitoring and control of landfill equipment and systems.
Comprehensive Landfill Services
EPA is hosting a free workshop in January on landfill monitoring and emissions. The workshops are scheduled twice, over half-day sessions. These sessions will include presentations highlighting the latest technological developments for monitoring and measuring landfill gas emissions.
Dates and Times: Register once for both sessions.
If you have any questions, please contact Shannon Banner at or John Evans at .
The unsung hero at landfills with a landfill gas collection system is the humble Wellfield Technician. The position of Wellfield Technician is multifaceted; this individual needs to be well equipped to deal with constant changes. A good technician is capable of:
All while communicating effectively with those on their team, during all kinds of weather and changing conditions.
One practice that most good Technicians embrace is keeping effective field notes. Those not engaging in this practice should consider doing so. Field notes and comments added to a row of monitoring data can be of great future value to the technician and the rest of the team. Accurate and detailed field notes contain information that can help the project team when it comes time to diagnose, repair, or troubleshoot various wellfield issues.
Whether it’s a handwritten entry in a logbook, a comment stored in a field instrument, or notes saved in a smartphone, tablet, or computer, the information recorded in field notes is indispensable for the proper, efficient maintenance of the wellfield.
Technicians are hard-pressed to recall every detail during the hectic daily push to get the wellfield read, while multitasking and keeping up with items that pop up at a moment’s notice. By keeping track of this information through note-taking or SCSeTools®, the technician can be more efficient over time – they won’t be scratching their head, trying to remember a detail important to a task.
Examples of items we track in our database include: wellhead valve positions, surging in vacuum supply risers at wellheads, required maintenance of sample ports, flex hoses, audible wellhead leaks, ponding water around wells, surface cracks around a well, and borehole backfill material settlement.
Regardless of how recorded, save field notes as valuable points of reference.
Handwritten notes are entered into a preventative maintenance program or a wellfield database so that they are accessible for use in planning repairs or troubleshooting problems. Another option is to capture them automatically, even noting the GSI coordinates into a database such as SCSeTools, to save time and lessen transcription errors.
Once completing wellfield monitoring and tuning, technicians then use comments or notes as a punch-list to return to the wellfield − ready to perform maintenance or repairs. These are the actions that keep the landfill gas collection components operating efficiently, and clients’ happy.

Learn more about Landfill Services here.
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
EPA’s Interpretation of “Begin Actual Construction” Under the New Source Review Preconstruction Permitting Regulations

The interpretation fails to give meaning to the distinction between an emissions unit and a major stationary source. As such, it tends to prevent source owners/operators from engaging in a wide range of preparatory activities they might otherwise desire to undertake before obtaining an NSR permit. For this reason, EPA is adopting a revised interpretation that is more consistent with the regulatory text.
The proposed revised interpretation will stipulate that a source owner or operator may, prior to obtaining an NSR permit, undertake physical on-site activities – including activities that may be costly, that may significantly alter the site, and/or are permanent in nature – provided that those activities do not constitute physical construction on an emissions unit.
Begin actual construction means, in general, initiation of physical on-site construction activities on an emissions unit, which are of a permanent nature. Such activities include, but are not limited to, installation of building supports and foundations, laying underground pipework and construction of permanent storage structures.
EPA does not find it plausible that NSR permit applicants undertaking significant on-site construction activities prior to permit issuance will allow them to gain leverage with respect to the outcome of the permitting process. Stationary source owners or operators cannot expect that any site activities prior to permitting will alter or influence the BACT analysis for an emissions unit or other elements of a permitting decision. Permit applicants that choose to undertake on-site construction activities in advance of permit issuance do so at their own risk.
EPA is providing an opportunity for interested stakeholders to review and comment on the draft guidance titled, Interpretation of “Begin Actual Construction” Under the New Source Review Preconstruction Permitting Regulations through May 11, 2020. For any questions concerning this memorandum, please contact Juan Santiago, Associate Division Director of the Air Quality Policy Division, Office of Air Quality Planning and Standards at (919) 541-1084 or .
Read the draft guidance: Interpretation of “Begin Actual Construction” Under the New Source Review Preconstruction Permitting Regulations
Submit comments using the form at . EPA will consider the comments received and complete a revised version of the guidance.
More information at Clean Air Act Services or Oil & Gas Permitting
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For many years, gas headers were designed and constructed outside of the landfill perimeter berm, on the landfill surface. Of course, landfill surface changes as waste elevation increases over time, resulting in many gas headers that now may be 30 feet or more below the current waste surface. Deeply buried gas headers are unreliable at best, and the operator loses access to them as soon as 20 feet of waste covers the header.
Collapsed gas headers buried deep in waste are an expensive challenge when operating a large number of gas wells connected to the gas header, and could cause serious compliance issues. Upon discovery of a collapsed buried gas header, installing a new header is a lengthy process with significant costs, not to mention the hurdles the operator will have to jump addressing noncompliance with their state agency.
The benefits of placing gas headers in the landfill perimeter are:
Since the condensate force main follows the gas header in the perimeter berm to flow to a tank or discharge point, there are additional maintenance benefits.
By continuing to design gas header construction on landfill slopes, all of the components end up on the landfill slope as well. You can imagine what type of complications the landfill operator will face since all of these components are in areas vulnerable to erosion, settlement, future filling or future construction. Additionally, any maintenance requiring digging and re-piping necessitates placing equipment on the landfill slope and disturbing the landfill slope surface for an extended period.
For more information about these benefits and more, please refer to the MSW Magazine article series Considerations for the Piping Network, the author, or contact SCS Engineers at .

Learn more at Landfill Engineering