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.
As technology advances to optimize landfill operations and ensure compliance, so does the amount and type of data available to support operators in making informed decisions.
The industry is adding more and more data points to fill in the story of a landfill’s health, driving this demand for ‘big data,’ delivered in real-time. Sprouting alongside this big data trend is another one: employers rely less on laptops and more on mobile devices, and they expect those devices to have sophisticated functionality.
In response, SCS Engineers launched SCS MobileTools®. This powerful app is the latest addition to SCSeTools®, a platform created to standardize data acquisition, optimize data use, and ensure that data is secure.
Watching in Real-Time
MobileTools enables field workers to pull up data on their iOS or Android mobile devices and observe real-time activity through a secure, wireless connection. It means they no longer have to connect instruments to their laptops and forward files to another source for upload to the eTools platform.
Instead, data goes from users’ smart devices to the cloud, enabling field workers, as well as operators and other decision-makers who work remotely, to access that information immediately.
“MobileTools builds on SCSeTools, which constantly takes in data and validates, analyzes, displays, and reports on that data. We realized that by incorporating technologies we’ve already built into this platform into the mobile devices, existing data acquisition workflows could be enhanced,” says Brooks Ballentine, SCS director of Software Development. “The result reduces effort and costs while increasing accuracy.”
“We’ve added wireless data transfer to MobileTools because the ability to access information within 24 hours is not good enough. We want to be within minutes to catch exceedances immediately,” says SCS engineer Sol Sim, who manages clients’ landfill gas operations.
“This is a real-time upload. So, if technicians are out in the field collecting data and a well has an exceedance, they can send a notice. If corrective action is required, the tech is already there to take that action,” he says.
Keeping Tabs on Flares
MobileTools is equally instrumental in keeping close tabs on flare activity, capturing information to identify overall flow trends, and ensuring the system meets stringent compliance requirements.
“Each flare has a data logger that records regulated parameters, such as gas flow and temperature. Data is stored minute-by-minute on the logger and typically requires an extensive manual process or expensive and complicated networked solutions to aggregate data in a centralized data repository. With MobileTools, this same data is transmitted in a simple process using existing mobile devices,” says Oliver Early, the product manager of SCSeTools-DataServices.
Early’s story around SCSeTools began in 2008. At the time, he was a client of SCS, paying to use the app to support a landfill gas-to-energy developer in ensuring regulatory compliance.
“I joined SCS in 2013 to come up with more features and push the app forward with new ideas and new ways of doing things, with wireless data transmission being the most recent advance,” he says.
Users of MobileTools can interact with site-specific data such as exceedance metrics for landfill gas, liquid levels, and surface emissions. And they access touch-enabled data charting to review daily gas loads recorded by flares.
MobileTools has the ability to attach photos to provide supporting visuals for more information and or to put data in context. This facilitates communication between field technicians, site managers, and corporate management, who can get a more tangible “picture” of what’s going on in the field.
As with every feature in the eTools suite, MobileTools is designed with data integrity and security in mind.
In the case of landfill operations monitoring data currently collected by hand, MobileTools will digitize the process, allowing for faster acquisition and near real-time analysis.
Integrating More and Different Data – Validation
“We are integrating data in MobileTools that is not currently collected on standardized instruments, such as liquid levels and pump cycle counts.
“So, with monitoring data that was recorded on paper, then entered into spreadsheets, techs now type it directly into the device. It is validated and then uploaded,” Ballentine says.
These and other features and functions are designed to be time and money savers. Field workers who now have a streamlined protocol can accomplish more in a day, freeing themselves for maintenance projects and other tasks. Operators can rely less on consultants to review data and identify potential issues or needed improvements.
Sim is part of the team involved in further developing and testing SCSeTools. That landfill practitioners developed the platform for landfill practitioners is key to its effectiveness, he surmises.
“We are not a software company dabbling in landfills; we are landfill operators. We know the industry, as well as the functionality needed in landfill software.
“Field engineers, staff, and technicians have been asking for a mobile app for some time. The ability to have data at our fingertips in the field is a tremendous tool for quickly troubleshooting issues,” Sim says.
Back in the day, environmental engineers and landfill operators had to create their own spreadsheets to track mountains of data, then try and figure out what all that data meant, a tedious process with limited functionality. But that’s changing, and SCSeTools® is at the forefront of the evolution. This powerful yet user-friendly digital platform automates data management; harnesses an ever-growing volume, type, and complexity of information; and expands on what solid waste professionals can do with that information.
Created by landfill practitioners, for landfill practitioners, SCSeTools collects, monitors, analyzes, and manages data on key landfill operations and assists in reporting. It’s leveraged by SCS staff and its clients nationwide to help facilitate sound operational and engineering decisions while saving time, labor, and money. Because operators get information in near-real time, they can act quickly and proactively should red flags spring up in their tightly regulated world.
The platform includes three modules: SCS DataServices®; SCS Groundwater™; SCS Leachate™; and the newest feature—SCS MobileTools®. Collectively these customizable toolsets have the flexibility to capture the big picture of a site’s overall health or zero in on what’s happening at a single gas wellhead, leachate collection sump, or other location. The modules’ design supports the smallest and largest sites and serves operators managing one, 10, or even hundreds of facilities.
From the Big Picture to the Fine Details
SCS DataServices is the flagship product and the one that SCS engineer Sol Sim uses most. This module captures and utilizes landfill gas facility monitoring and management data. It’s also designed to serve as a compliance reporting tool.
Sim likes to tap into the app to look through different lenses, depending on what he needs to see and understand.
“You can use SCS DataServices to get a broad overview of what is happening, but you can also drill down to see where you need to focus to ensure you are spending time and resources efficiently,” he says.
Being able to dissect large volumes of data quickly, then key into the finer details as needed has made his job easier. And he can work smarter and faster.
“Without this tool, it’s a bit of a needle in a haystack. But now, we can easily visualize and pick out relevant, near real-time data to assess performance. And when there are deficiencies, we can make adjustments promptly—maybe upgrade a wellhead or upgrade laterals to optimize gas production,” he says.
Connecting the Dots in a Visual Format
The GIS mapping function, a component of DataServices, has been one of Sim’s go-to tools. It provides data points for individual locations within a landfill system and helps connect the dots in a visual format.
“You have point references and can spatially display a lot of data at once so, unlike with a spreadsheet format, you can see and process where a well is in relation to others,” he says.
Custom mapping captures any parameter, whether data points around gas flow, header vacuum or gas quality. Ranges are set to identify trends and, ultimately, provide information to make more informed decisions.
This ability to spot trends or patterns is integrated into features beyond mapping. A built-in algorithm helps determine if a client’s operations are trending in the right direction, and that determination can be made as patterns unfold, which helps field staff stay on top of the curve.
“If changes occur slowly, it typically takes time to notice, but if you look at six months or more of data at a time, you see that 1 percent change in temperature or flow, for example, that has crept up incrementally. You have one visual snapshot that captures a lot of data fast. So, if there are issues, you can get to the route quickly and make adjustments practically in real-time,” Sim says.
The DataServices module has served well as a troubleshooting tool. Sim illustrates with a real-life scenario: a client whose landfill gas-to-energy project was grossly underperforming.
“They had data but no way to review it efficiently to try and understand what was happening. They were ready to bring in a new operator. We were able to come in; upload their data into our system; identify the problem; and make easy, relatively inexpensive upgrades that increased their gas extraction by close to 15 percent.”
Besides helping to realize direct dollar benefits, the tool can compute and outline deficiencies from a regulatory standpoint.
“Our client had outstanding past exceedances that had not been remedied properly. We helped them get back into compliance and mitigate potential future issues that could have resulted in fines,” Sim says.
When SCSeTools was created, the primary goals were to standardize data acquisition and ensure that the data was secure. It was used internally at first, at a few landfills. Clients began asking for it, and now the toolsets are leveraged at over 650 locations across the country, both by SCS and clients who operate their sites.
Ensuring Data Integrity – Simplifying Processes
It continues to evolve, with one of the early advances being encryption of data collected in the field, which means that it can’t be modified when transmitted to the app.
Before, there could be errors if a file was interrupted or data mishandled as it moved along the chain of custody, explains Oliver Early, the product manager of SCSeTools.
“And now we have taken the capabilities even further,” says Brooks Ballentine, SCS director of Software Development.
“Today, we are enhancing MobileTools so field technicians can enter and transmit data directly from their mobile device to SCSeTools. This not only ensures data integrity but simplifies the process,” he says.
Data integrity and ease were the front and center focuses while designing each feature and function. Another example of this is that the software enables gas measuring instruments to be configured to align with well configurations.
“Every gas well has a unique configuration, and they are often reconfigured. Because we can synchronize the configurations from eTools to each technician’s instrument, we end up with more accurate, consistent readings, when, before, that was impossible,” Early says.
Staying On Top of Timelines
Operators must stay on their game to keep up with regulated monitoring timelines, whether involving activity at wells, monitoring probes, or flares. Some sites have hundreds or even thousands of data points with individual data timelines and, what’s more, those timelines can change. DataServices, in particular, works to simplify the detail-heavy process. It supports operators in better managing prescribed monitoring events in a couple of ways: by enabling them to view data for a specific monitoring period and by allowing them to set events to align with mandated periods.
So, if systems were out of compliance and now have to be monitored more often, the frequency can be set accordingly.
In addition to DataServices, with its robust capabilities around managing landfill gas systems data, the SCSeTools suite features two more modules: the leachate and groundwater modules. These tools are designed to support processes established to ensure regulatory compliance, optimize operational efficiency, and save costs.
SCS Leachate provides relevant information to help determine the most efficient and economical leachate disposal methods. The app manages the input, analysis, review, and export of information such as leachate origin, volume of fluids, and sample lab results for specific collection points.
The module charts and graphs leachate data by disposal method and site or multiple sites. Then, it can determine trends in leachate disposal totals using established parameters associated with leachate management.
“Once all this data is gathered and logged, users can run reports and come up with disposal costs based on data provided by clients. We can track and trend how much operators are currently spending on leachate disposal to help them optimize liquid management and plan budgets for the next year,” Ballentine says.
SCS Groundwater tracks constituents to help manage water quality and to mitigate or remediate issues. It was developed to enhance operational efficiencies while also providing a means to validate that reporting requirements are being met.
Users can set up and track monitoring plans consisting of sampling points and required analyses at each point. They can track the datasets of constituents, as well as constituents within each dataset that they are required to monitor. These constituents can be tracked over time to determine if seepages are controlled and follow progress if adjustments are required.
Once the data is uploaded into SCS Groundwater, the app checks it against the monitoring plan to verify that all work is complete. “This is a key feature because the number of possible methods, and associated analytes, is large, and ensuring that the required testing project has been completed correctly is critical,” Ballentine says.
“We are not done”: Expanding Capabilities
SCSeTools, with its three modules and mobile app, has advanced over time to keep pace with operators’ needs in an ever-changing, complex industry, and Sim says, “We are not done. We continue to leverage new technologies and to add features and functions so that we can make the best, most cost-effective decisions possible on behalf of our clients.”