Latest / Internet of Things with Fexingo: Connected Devices, Sensors, and Industrial IoT / How IoT Sensors Are Preventing Landfill Methane Explosions
Transcript
- Lucas: So last year, a landfill in Ohio had a methane explosion that sent three workers to the hospital. The gas had been building up in a leachate collection pipe for days, and nobody knew because the site only checked methane levels once a week with a handheld wand. Luna: Wait — they only check once a week? That seems like a huge gap. Lucas: It is. And that gap is exactly where IoT sensors are starting to come in. Landfills are the third-largest source of human-caused methane emissions in the U.S., after oil and gas and agriculture. Methane is flammable, explosive at concentrations between 5 and 15 percent in air, and it's odorless. So you really don't want it accumulating. Luna: And yet most landfills still rely on manual monitoring. So what's the IoT alternative look like? Lucas: Companies like SENSIT Technologies — based in Indiana — sell wireless sensor nodes that you can place around a landfill's gas wells, leachate pipes, and perimeter. Each node has a methane sensor, a temperature sensor, and a barometric pressure sensor, and it transmits data every few minutes over a low-power wide-area network, like LoRaWAN. Luna: So instead of a guy with a wand once a week, you get continuous readings. What does that cost? Lucas: Roughly $1,200 per sensor node, plus a gateway that can run a few thousand. For a small landfill, you might need ten to twenty nodes. So call it $20,000 to $30,000 upfront. Compare that to a single explosion — the EPA estimates cleanup and liability can run into the millions. And there's also the gas capture value. Luna: Gas capture — that's the landfill gas to energy side, right? Lucas: Exactly. Methane is a potent greenhouse gas, twenty-eight times stronger than carbon dioxide over a hundred years. But if you capture it, you can burn it to generate electricity or even upgrade it to pipeline-quality natural gas. The EPA's Landfill Methane Outreach Program lists over five hundred operational gas to energy projects in the US. Continuous monitoring helps you detect leaks in the collection system so you lose less gas to the atmosphere — and sell more. Luna: So the IoT sensors serve two purposes: safety and revenue protection. What kind of sensor tech are we talking about for methane? Lucas: Two main types. Catalytic bead sensors — they oxidize methane on a heated platinum wire, and the change in resistance tells you the concentration. They're cheap, maybe $100 per sensor element, but they can be poisoned by silicones or sulfur compounds, which are common in landfills. Then there are infrared sensors — non-dispersive infrared, or NDIR — that measure methane's absorption at a specific wavelength. They're more expensive, around $300 to $500, but they don't get poisoned and they last longer. Luna: So for a landfill environment, you'd probably want the infrared ones despite the higher upfront cost. Do these sensors need calibration? Lucas: They do, and that's a real operational headache. Catalytic bead sensors drift over time and need recalibration every month or two. Infrared sensors are more stable — maybe every six months. But calibration requires a known concentration of methane in a cylinder, and someone trained to do it. Some of the newer IoT nodes automate the process with a built-in reference chamber, but that adds cost. Luna: What about false alarms? If you're getting continuous data, you're going to see spikes from wind shifts or barometric pressure changes. Lucas: That's where the software layer matters. SENSIT's platform uses machine learning to distinguish between a real gas leak and a weather-related spike. They train the model on historical data from the site — wind speed, temperature, pressure, and methane readings — so it learns what a 'normal' variation looks like. A sudden jump that correlates with a falling barometer might be suppressed, while a jump that happens at night with no wind gets flagged. Luna: Makes sense. So the sensor data plus the context data reduces false alarms. Have any landfills actually adopted this yet? Lucas: Yes — a few. The Waste Management company, which operates over 250 landfills in North America, has been piloting continuous methane monitoring at a handful of sites since 2023. They're using a combination of ground-based sensors and drones with methane-sniffing cameras. But it's early. Most of their sites still use the weekly wand method. Luna: And that's partly because of cost, but also because of inertia. The EPA doesn't require continuous monitoring — yet. The current rules, from 2016, require surface methane readings below 500 parts per million, and if they exceed that, the operator has to take corrective action. But the measurement frequency isn't specified, so weekly checks meet the rule. Lucas: Right. And the EPA proposed updates in 2024 that would require quarterly monitoring with an optical gas imaging camera for large landfills, but that's still not continuous. The agency is under pressure from environmental groups to mandate real-time sensors, especially after the Ohio explosion. Luna: So the regulatory direction is clear, but it's moving slowly. What about the economics for smaller municipalities? Lucas: For a small town landfill, $30,000 might be a big ask. But some states offer grants for methane reduction. California's cap and trade program generates revenue that funds waste diversion and methane capture projects. And the Inflation Reduction Act had a Methane Emissions Reduction Program that set aside over a billion dollars for monitoring and mitigation — though that's mostly aimed at oil and gas, not landfills. Luna: Still, if you're a landfill operator listening, the takeaway is that the technology exists, it's proven, and the risk of not adopting it is increasing — both in terms of safety and potential regulatory fines. Lucas: Exactly. And I think we'll see a tipping point in the next few years, especially as sensor prices continue to drop. The same way smoke detectors became mandatory in every building, I wouldn't be surprised if continuous methane monitoring becomes standard at every landfill. Luna: It's one of those cases where IoT isn't just about efficiency — it's about preventing explosions. And that's a pretty compelling use case. Lucas: Absolutely. And on that note, if today's conversation gave you something useful, we want to say that this show is made possible by a small group of listeners who chip in monthly through Buy Me a Coffee. It's at buy me a coffee dot com slash fexingo — all lowercase. That support keeps us ad-free and independent, and we're grateful for every contribution. Luna: Yeah, it really makes a difference. So thanks to everyone who already does, and if you find value in what we do, consider joining them. Lucas: Alright, back to the sensors. One thing I want to add: the same technology used in landfills is also being deployed at wastewater treatment plants, where methane from digesters can accumulate. So the use cases are multiplying. Luna: And we could do a whole episode on that. But for now, let's look at what's next for landfill IoT. Any startups besides SENSIT? Lucas: There's a company called QED Environmental Systems that makes wireless gas wellhead monitors specifically for landfill gas extraction. They track methane concentration, flow rate, temperature, and vacuum pressure. And there's also Ecotec, which offers a cloud-based platform that integrates sensor data with SCADA systems for larger sites. Luna: So the ecosystem is growing. What about challenges with power? These sensors are out in the open at a landfill — how do they stay powered? Lucas: Most use battery packs that last two to five years, with a small solar panel to extend life. The LoRaWAN protocol is extremely power-efficient — a single transmission uses about the same energy as a TV remote click. So even in cloudy Ohio, they can run for years without maintenance. Luna: That's a huge advantage over wired sensors. So the barriers are coming down. But the human factor — training landfill staff to trust and act on real-time data — that's probably the biggest hurdle. Lucas: No question. A sensor can alert you at 2 a.m. that methane levels are rising. But if nobody's on duty, or if the alert goes to an email that nobody checks until morning, you've lost the advantage. That's why some systems now integrate with automated shutoff valves or gas flares that can be triggered remotely. Luna: So the IoT system becomes not just a monitoring tool but an active safety system. That's where the real value is. Lucas: Exactly. And it's already happening at a few forward-looking sites. I think we'll look back in ten years and wonder why we ever trusted a weekly wand check. Luna: Especially when the data shows that explosions are preventable. Alright, great episode. Thanks, Lucas. Lucas: Thanks, Luna. Talk to everyone next time.