Hydrogen sulfide (H2S) levels are creeping up at some landfills, especially those that take C&D waste; some are seeing concentrations in the thousands to 30,000 parts per million (up from about 20 to 40 ppm ten years ago). And even at very low concentrations, H2S can be problematic.
Material Recovery Facility residuals, which typically contain significant amounts of pulverized drywall, are high in gypsum and sulfate. Once broken down, residuals become a high-surface-area material, leaching into and spreading through waste. When reacting with water and organics, it can potentially generate H2S. With a drive to divert more C&D debris, and regulations tightening around H2S, operators’ jobs get harder as they work to stave off emissions from this corrosive, flammable compound notorious for its “rotten egg” odor.
When building out their gas collection systems, controlling H2S becomes even more daunting. Sol Sim, an SCS Engineers Vice President, explains, “We see H2S concentrations jump when we expand landfill gas collection systems, often in cells that contain C&D residual screening materials. The gas was there all along but sequestered. Now it’s coming out of the ground, and the onset of issues can spike suddenly.”
When spikes come on quickly, Sim’s team implements turnkey interim treatment approaches. They start by identifying the gas collection wells with the highest contributors and act fast to get them into compliance.
SCS teams take a two-pronged approach by stepping back and thinking about the big picture while taking action. It provides a major advantage to moving too quickly.
The more data, the better. Your engineers can simulate treatment with various media to assess the impact on flare inlet concentrations. And knowing potential impact at the flare is critical; it’s the compliance point where regulators measure sulfur dioxide (SO2) emissions.
SO2 can’t be controlled through combustion, so removing H2S from waste before sending gas to the flare is essential. Sim thinks back to problems he’s investigated for clients who had SO2 sneak up on them, causing failed sulfur dioxide emissions testing.
The proactive measure of identifying problematic gas wells and treating them is key to staying in compliance. And Sim often finds clients using interim solutions as long as they can. He has seen them work well for up to five years but they don’t resolve operators’ long-term issues, which will become more challenging as our waste streams continue to change or as landfills continue to accept more and more C&D materials.
“We solve immediate issues, address the impact of incoming materials several years in advance, and begin planning for the next 20 years. It’s how we determine strategies to minimize emissions and improve efficiencies into the future with consideration to needs as landfilling and recycling evolve.”
“We’re going to investigate thoroughly to pinpoint and understand the cause, but we do take immediate action in the interim. As part of the solution, we’ll develop an informed strategy to prevent issues well into the future,” he says.
For the longer haul, it takes time to get building permits. Coming up with permanent engineering designs and treatments requires a lot of troubleshooting and research. Even once engineers identify a lasting fix, it takes time to manufacture and install larger vessels and other infrastructure.
But they don’t wait for all these pieces to come together to act.
The priority is getting operators in compliance right away or taking down emissions if they are on the verge of noncompliance. As work begins, operators can breathe a little easier knowing they have time to figure out how to allocate resources and funds to implement a more permanent strategy.
“We’ve seen where data we’ve gathered while working on the immediate problem enables our clients to gain insight to make good decisions around rightsizing their infrastructure moving forward,” Sim says.
Watch and study while addressing the immediate problem.
Sim emphasizes that operators should not be surprised or act too quickly when they turn on the gas extraction system and see spikes in H2S concentrations. There is usually an initial spike from a new high H2S producing area at the onset of gas collection. He has seen operators abruptly stop extracting, which can lead to odors or other compliance issues.
“When you put in a treatment system, you can take out the initial surge in H2S to allow time for the concentrations to level out. It’s important to allow that window for initial surges to run their course to understand the problem better. Otherwise, you could over-design your system around a short-term event,” Sim advises.
He points to a real-life scenario: a site that skipped the interim step of starting with a less expensive initial solution. Once they started drawing on the gas, they realized the problem was not as substantial as originally thought, and they didn’t need a multi-million-dollar system in the end.
A balancing act.
“Imagine H2S generation as an expanding balloon; if you pop it, air rushes out fast [akin to when you first pull gas from the ground]. That concentration level scares people. But if you react by shutting off extraction points, your balloon will continue to expand and eventually create odor problems. The goal is to extract the gas and H2S at the rate it is being generated, so it’s a balancing act, where expertise and technology both play key roles,” Sim says.
Early work typically begins by identifying wells that are the highest contributors and concentrating efforts there. It’s a complex process as sites can have fifty to thousands of collection points. Having the historical data and saving the data to watch the trend makes identifying and analyzing specific wells or clusters much more efficient.
Successfully attacking those high offenders requires an understanding of flow and concentrations. After locating the problem area, Sim takes samples using Dräger tubes at strategic points throughout individual wells and headers to identify concentrations. Gas well monitoring and the corresponding flow data will tell you if you’ve taken emissions down sufficiently.
More Resources:
SCSeTools Landfill Data Monitoring and Analysis
Staying Ahead of Odor Management at Solid Waste Facilities
On September 15, Governor Pritzker signed Senate Bill 2408, forming the Illinois Energy Transition Act. The Act advances renewable energy goals and the path to carbon-free electricity generation by 2045. To say this bill will impact the Illinois electrical utility landscape is an understatement.
Illinois is a top energy producer and consumer in the upper Midwest. The Act requires displacement of more than 6,000 MWh provided from coal and natural gas. One average MWh is enough to power 796 homes for a year in the U.S.
Energy efficiencies and implementing alternative energy resources will be an increasingly important strategy to mitigate the cost impacts from this Act to all users: residential, commercial, industrial, and municipal.
SCS supports clients with the decommissioning and legacy management of coal-fired facilities and renewable energy development. Our environmental team in Illinois includes local experts, Scott Knoepke and Richard Southorn who support the management of coal-fired facilities with Coal Combustion Residuals (CCR) and assist utilities transitioning to renewable natural gas installments and solar energy sources. For coal-fired facilities with CCR impoundments, SCS’s Illinois Office provides design, closure, construction quality assurance, and site stewardship (e.g., long-term maintenance, groundwater monitoring, and reporting).
SCS uses a specialized team for solar implementation on landfills and Brownfields. Knoepke and Southorn are supported by SCS National Experts in the region to assess and implement Solar Energy on Landfills & Brownfields.
The Act defines that landfill gas produced in Illinois as a renewable energy resource. SCS Engineers has one of the longest and most successful Biogas practices in the United States. SCS designs, constructs, and operates more Biogas, Anaerobic Digestion, Renewable Natural Gas, Ag Digester systems than any other engineering firm in the nation. Our clients attribute our quality and high production rates to our practice specializing in waste gas utilization, combined with our expertise in solid waste management and compliance.
New Chicago office location at 40 Shuman Boulevard, Suite 216, Naperville, IL 60563
SCS Engineers continues expanding its environmental team in its Chicago, Illinois office to meet environmental engineering and consulting needs focusing on waste management and the needs of the electric utilities. Driving demands are industries and municipalities seeking to reduce their environmental footprint while providing essential services and products.
Leading the Chicagoland team, Professional Engineer and Professional Geologist Scott Knoepke. Knoepke serves clients needing remediation and site redevelopment. This includes commercial dry cleaners, retail petroleum sites, and heavy industries such as steel, rail, coal, mining, manufacturing, metal cutting, and plating.
Meet the Crew!
Richard Southorn, PE, PG, with 20 years of experience, joins Knoepke supporting solid waste and electric utility sectors. Southorn began his career in the field performing CQA oversight, environmental monitoring, and soil core/rock core logging at landfill sites. He moved into landfill design and modeling, primarily to support landfill expansion projects. Richard has extensive experience with site layouts, geotechnical stability, stormwater management, and leachate generation analyses.
Brett Miller is a Senior Designer with over 20 years of experience and proficiency in AutoCAD Civil 3D and Maya. Brett is capable of any production drafting and is highly skilled in understanding 3D space. This helps him support designs that fit into site-specific, real-world environments. Brett also creates 3D models and animations that illustrate the benefits of a design to our clients.
Niko Villanueva, PE, joins SCS with eight years of experience. Niko provides engineering and drafting support and is experienced in designing various landfill systems such as stormwater management, leachate and gas control, and foundation analysis. He has also prepared cost estimates and construction bid quantities for various projects and construction quality assurance services at multiple facilities.
Meet Spencer LaBelle, with six years of experience. Spencer provides solutions for stormwater-related projects, including stormwater management system design, permitting, and compliance. He provides a diverse portfolio of clients and industries with stormwater-related services and environmental compliance.
Zack Christ, PE, comes to SCS with 15 years of experience in solid waste and CCR landfill sectors. Zack has experience performing CQA oversight and CQA management of landfill final cover, base liner, and GCCS; environmental monitoring; and logging soil borings. He also has extensive landfill design and CAD experience in developing landfill siting and permitting application projects. Zack’s areas of expertise include geotechnical analyses, stormwater management, leachate management design, GCCS design, and cost estimating.
Recently the state of Wisconsin released its updated 2020-2021 statewide waste characterization study. The study found that the broad organics category, including yard waste and diapers, accounted for about 1.3 million tons. An estimated 924,900 tons of paper, including cardboard, compostable and office paper, comprised about 21 percent of the landfills’ tonnage. That was followed by plastic at about 17 percent or 745,600 tons.
You can read the study, but why do local governments, states, and waste management businesses request these studies? Because waste and landfills are expensive to manage. Diverting waste from landfills cuts greenhouse gases and supplies materials for reuse as new products or compost – a more sustainable system.
Waste characterization information is designed for solid waste planning; however, anyone interested in the characteristics of the solid waste stream may find it useful. Studies can also target specific waste or needs such as construction and demolition waste and business waste generators. A generator means a person, specific location, or business that creates waste.
These studies help start answering questions such as:
States, jurisdictions, citizens, and businesses can use this information as a planning tool to help meet state mandates and their goals to reduce waste and achieve the benefits of sustainable practices. Kudos to Wisconsin, Iowa, and California, several of the many states moving toward more circular waste management!
As the world faces environmental, social, and economic challenges, environmental education can transform lives and society by addressing these challenges. SCS’s Young Professionals Planning Committee collected $3,683 for the NAAEE – North American Association for Environmental Education this summer.
SCSers generously contributed toward funding scholarships, research, outreach focusing on K-12 programs, justice, and diversity programs. SCS Corporate matches employee donations for a total of $7,366 raised for NAAEE.
Education and association participation play an important part in SCS’s mission to promote a sustainable environment through innovation and the creative application of technology and management strategies.
SCS Engineers proudly sponsors the 2021-2022 California State University Long Beach (CSULB) NASA RMC team: The Space Sharks, participating in NASA’s upcoming LUNABOTIC competition. The annual NASA LUNABOTICS competition is a hands-on engineering exercise where students receive practical experience in the full engineering lifecycle process from concept development to system closeout.
This Artemis Student Challenge trains university students in the methods of NASA systems engineering while designing, building, and operating an exciting lunar excavator prototype. The Space Sharks are composed of passionate students from mechanical engineering, electrical engineering, and computer science. They are a collaborative team of students from all disciplines and grade levels working towards the ultimate goal of achieving first place in the NASA Lunabotics Competition. The goal is for each member to work in a team setting to design, build, and execute a shopping-cart-sized rover.
According to NASA, rovers need to be compact, lightweight, and rugged to launch with minimum cost but withstand the rigors of terrestrial mining operations in difficult-to-reach or dangerous locations. NASA desires excavation in future space missions for In Situ Resource Utilization (ISRU) to make local commodities, such as propellants and breathing air, and pursue construction operations on the Moon, Mars, an asteroid, or a comet in the future.
Over nine months, Space Sharks will go through the engineering processes to design, build, and test a robot rover that can mine for regolith autonomously. It will be necessary to excavate lunar regolith to extract local resources, maintaining a sustainable presence on the Moon, so they don’t have to be transported from Earth through its deep gravity well.
Check out their efforts here: Teaser Video 2020/2021 – YouTube
Website: https://beachrmc.com/
Instagram: https://www.instagram.com/csulb.rmc/
In August, the U.S. Department of Energy (DOE) announced nearly $34 million in funding for 11 projects that will support high-impact research and development to improve and produce biofuels, biopower, and bioproducts. These biomass resources, otherwise known as feedstocks, can be produced by municipal solid waste (MSW) streams and algae and converted into low-carbon fuels that can significantly contribute to the decarbonization of transportation sectors that face barriers to electrification, like aviation and marine.
Transportation accounts for approximately 30% of total U.S. energy consumption and generates the largest share of the country’s greenhouse gas emissions. Biofuels serve as a low-carbon alternative to petroleum and can also be used to produce carbon-heavy products like plastics, fertilizers, lubricants, and industrial chemicals.
Among the DOE recipients is a team led by Stephanie Lansing, professor in the Department of Environmental Science and Technology at the University of Maryland (UMD). Lansing is leading a consortium of scientists and industry partners to research innovative ways to use waste and to make value-added products that will contribute to the sustainability of our economy and planet.
SCS Engineers is an environmental engineering firm specializing in waste management and renewable energy from waste products. SCS is on the Lansing team focusing on biofuel production. The team includes Ohio State University, Mississippi State University, Virginia Tech, Idaho National Lab, and Quasar Energy Group. Their first task is to conduct a waste characterization study across every U.S. region during every season of the year, to understand how location and the time of year affect landfills’ incoming waste. The results help determine what the biofuel potential of that waste is.
Another Lansing team will be working toward producing bioplastics that are made without using fossil fuels and degrade much more easily than current plastic products.
The biofuel and bioplastic projects involve sustainability and economic assessments comparing them to current products on the market to see how marketable these new products can be. And the reason why Lansing’s comprehensive teams are important; they will help commercialize any new products.
Secretary of Energy Jennifer Granholm stated in the DOE August 3 press release, “The companies and universities leading these projects will ensure that our cutting-edge biofuel technologies reduce carbon emissions, create new jobs up and down the supply chain, and are made in America by American workers.”
More information about Solid Waste Management and Biofuels.
California’s 2021 and 2022 budgets provide $500 million to the Department of Toxic Substances Control to support community revitalization. The funds are available over four years to accelerate the investigation and cleanup of contaminated properties in environmental justice communities. This funding is referred to as the Cleanup in Vulnerable Communities Initiative. A portion of this funding is for establishing the Equitable Community Revitalization Grant (ECRG)—a grant program to incentivize cleanup and investment in disadvantaged areas of California.
Equitable Community Revitalization Grant – Learn more about the program and how to use this funding to advance your communities brownfields and remediation projects.
Brownfields and Voluntary Remediation – Brownfield and voluntary remediation projects protect human health and the environment while restoring beneficial use to properties. SCS Engineers is a pioneer in supporting the public-private partnerships for these types of redevelopment. SCS helped redevelop environmentally impaired real estate more than 25 years before the term Brownfield was coined. Learn more about the possibilities for your community and how to select a brownfields remediation professional for timely and compliant delivery of the benefits.
ECRG Flyer – Provides the basics on this new and important funding along with a timetable.
Progressive energy companies are rushing to corner the growing hydrogen market, excited as they see this renewable fuel’s cost steadily drop and as they prioritize decarbonization.
As they work to stay ahead of the pack, they need to put time and thought into building out and implementing these projects. There are complex technical and regulatory considerations; safety is also priority one at every step when managing this flammable, compressed gas.
As the market takes off, there is a need for scaled development along the whole supply chain, and some developers are rising to the occasion for more control and more opportunity. Rather than only build fueling stations, they buy into vertically integrated hydrogen networks to produce, transport and distribute hydrogen. But these multifaceted projects present even more complexity— calling for a team with highly specialized, comprehensive skill sets.
SCS Engineers supports energy companies and contractors looking to diversify their hydrogen services portfolio to include building production plants, including moving the gas via pipeline or truck to offload at fueling stations, ultimately selling to consumers.
“We enter these strategic partnerships to give our clients what they are looking for: a full spectrum of competencies and services; and a proven history of working on hydrogen to deliver turnkey projects. The idea is to take the environmental burden off clients as they pursue these major undertakings,” says Nathan Eady, an SCS vice president, and project manager.
SCS makes site selection; performs environmental due diligence and remediation; feasibility analysis; design and construction of environmental controls; land use, air, and water quality permitting.
The contractors’ specializations are detailed design, engineering, and construction management–from civil to structural to mechanical and fire protection.
This team meets all environmental and regulatory design requirements and develops process safety management and risk management plans with their combined expertise. They also take on the role of community educator, explaining the unique attributes of hydrogen and easing any concerns.
“We take science and engineering and translate that for neighbors and city councils. It’s important to show communities, as well as regulators, that these facilities are designed and operated with the utmost safety,” Eady says.
Requirements vary from jurisdiction to jurisdiction. But with a national reach, SCS sails through processes and regulations by region.
“That matters to our clients; they want to get through the detailed permitting steps and launch as soon as they can to maintain their competitive edge. And when they plan to expand into other regions, they like to know they already have a vetted team in place who knows the territory and can do the work there,” he says.
Permitting and technical considerations vary by location and production method, whether via steam methane reforming (SMR) or electrolysis.
Some operators are taken off-guard by the air quality permitting requirements associated with SMR facilities − or the stringent wildlife and water quality regulations encountered with the larger footprint photovoltaic systems requiring open space to support electrolysis. SCS has the expertise to address the issues, whether state-specific cap and trade regulations for carbon emissions or air basin specific criteria pollutants. SCS also has the unique talent of finding brownfield sites or closed landfill properties, making excellent receiver sites for electrolysis and solar facilities near existing infrastructure.
Building hydrogen projects on these idle properties can save developers significant time and money in the overall project outcome.
“We do a lot of brownfield work helping to clean and redevelop these properties. These sites have special permitting considerations, especially since they typically have a history of industrial use,” Eady says.
SCS performs Phase I Assessments to research records on previous use, and if the team finds a potential problem, they move to Phase II, which entails groundwater and soil testing.
“If we find evidence of existing contamination, we reconcile it so our clients can move forward with the development of their new facilities,” Eady says.
SCS is seeing a growing interest in building hydrogen projects on closed landfills. As brownfields, they have value for their open space and often have some existing infrastructure, offsetting the cost of building new.
“We have done permitting and design work on several closed landfills, sometimes adding solar systems. Hydrogen projects leveraging electrolysis require a tremendous amount of electricity, and when we can bypass the grid enabling clients to make their own electricity, it’s a major plus,” Eady says.
Lately, large energy companies are pivoting from conventional oil and gas to hydrogen, and some smaller, young companies are also joining the clean renewables movement.
SCS has gotten interest from startups looking to obtain government grants and subsidies. Some of these firms need more process engineering support to ensure their new technology can operate at a cost and environmental efficacy equivalent to larger operations.
“We use our knowledge gained working with major conventional energy companies to support these new hydrogen firms in executing successful launches. All in all, a positive trend.”
Together, SCS and its partners play an integral role in helping to see hydrogen continue to climb the energy sector ranks, maintaining an excellent record of accomplishment supporting the planning-design-build of clean-energy plants.
Additional Resources
Accumulating liquids are problematic for landfills taking sludges and other wet wastes not traditionally part of the incoming waste stream. Add to the mix increasing precipitation, and operators could be staring down the perfect storm—especially as they work to optimize their gas extraction systems. Here’s the challenge, explains Pete Carrico, SCS Engineers Senior Vice President and national expert on liquids management:
“Trash is porous, and the soils used for daily and intermediate cover usually aren’t, so liquid gets trapped between alternating trash layers as the landfill fills. These “perched” liquids can drain into well columns and block the slotted portion of the extraction well piping that withdraws gas from waste and into the gas collection system.”
Even a robust vacuum on the wells will not pull gas once pipes fill with fluid. With no path to move it from trash into the collection infrastructure, operators work harder to stave off odor and slope stability issues, among potential resulting problems.
The good news is they have a recourse to remove the liquids, unblock well perforations, and extract more gas. They do it by installing dewatering systems: an intricate network of pneumatic pumps, air lines to power them, and conveyance lines, also known as force mains, to remove liquid.
Manufacturers have designed and redesigned their pumps to try and address problems specific to landfill gas extraction systems. And the equipment does the job but requires meticulous attention and skill to keep all the moving parts going. These liquids are rough on pumps due to their harsh nature. The suspended solids and biological material they contain are the biggest challenges, and if the landfill has high temperatures, these liquids can heat up, further taxing the system, Carrico says.
“No pump indefinitely survives the challenging conditions you have in landfills. So, where we can make the biggest difference is with these maintenance programs,” Carrico says. You’re spending O&M budget on what provides the most impact.”
SCS uses dedicated, factory-trained pump crews who focus solely on operating and maintaining gas extraction dewatering systems. These crews help ensure the infrastructure functions as it should, and gas moves through well piping slots, into the gas header piping, and to the blower/flare station for beneficial end-use.
“Operations run more smoothly with these crews in place. An SCS field crew is as unique as each landfill. Our specialists have various skill sets, i.e., gas collection system monitoring, surface emissions monitoring, or pump maintenance expertise. That’s how we produce better outcomes in terms of pump performance. If you effectively maintain and repair the pumps, you will restore them to their designed specifications, pump more liquids, and with greater ease,” Carrico says.
The teams, who work on landfills across the country, stay busy. One site can have five to 300-plus pumps, each with multiple components, and they must be removed and cleaned frequently.
Replacing worn, fouled, or damaged components is an especially tedious and complex job.
Some wells are 70 to 100 feet deep. Pulling air lines, liquid lines, and pumps out from that depth is hard and requires special equipment to do safely. SCS crews know how to take them apart and put them back together; they don’t just lower them back in the ground after working on them. But hook them up to air and water lines and watch them work at capacity before returning them to service.
It’s a value add; with a good maintenance plan and the right crew, pumps can be kept at their designed specifications and run efficiently for many years. They can typically be cleaned and reset for a fraction of their replacement cost.
“We leverage our size and resources. We have a deep bench of in-house experts and engineers willing to share information to help with problems, which is important as conditions vary at each site, as can problems and solutions. So, it’s important not to do this in a silo but rather pull from our broader knowledge base,” Carrico says.
Technology helps too, especially with tracking, maintaining, and reporting progress to clients. A geographical information system (GIS) maps each well’s location, and pump technicians upload data corresponding to each one from wireless tablets almost instantaneously.
The ability to automate tracking and display critical information right away on a dashboard has increased our program’s efficiency. Technicians spend less time tracking and look at analyses of all the landfill conditions to know where to concentrate their efforts, Carrico says.
A few landfills are working to avoid pumping liquids altogether. They are building large gabion rock structures at the landfill’s base, with piping that connects to the extraction well system, creating a conduit. Liquids automatically drain to the bottom where leachate is intended to go while effectively pulling more gas into the gas collection system.
“This is a newer trend that some of our clients are already doing. And we are involved supporting the well designs,” Carrico says.
For now, in most cases, achieving the best outcomes is about investing in pumps and a good maintenance program.
“Monitoring and regularly measuring—checking stroke-counters, which show how many times a pump cycles, and checking flow meters to know how many gallons a day a system produces are key to finding savings. It’s how you reduce or prevent catastrophic failures,” says Greg Hansen, Senior Project Manager with SCS Field Services Operations, Maintenance & Monitoring.
To execute properly, Hansen provides this advice for operators setting up a pump program:
Have pump maintenance areas with water, electricity, disposal means for waste liquids, and storage facilities for spare parts and tools. More specifically:
Operators planning on doing maintenance in-house should train their technicians on cleaning, servicing, and testing pumps. Either SCS or the pump manufacturer can provide this training.
Above all, Hansen says, “You need a comprehensive OM&M program. The better the job tuning pumps, the better they do in the field, and the longer they work before being cleaned or repaired. It’s a continual process.”
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