Latest / Internet of Things with Fexingo: Connected Devices, Sensors, and Industrial IoT / How IoT Sensors Are Preventing Landfill Gas Migration Explosions
Transcript
- Lucas: If you live near an old landfill, the ground beneath your home could be slowly filling with methane — and you'd have no idea until it's too late. Luna: That's genuinely terrifying. I thought landfills capped their waste and that was the end of it. Lucas: That's the common assumption. But a landfill isn't just a pile of trash — it's a bioreactor. Even decades after closure, organic waste keeps decomposing anaerobically, producing methane and carbon dioxide. The cap and gas collection system slow the release, but they don't stop it entirely. And the gas can migrate horizontally through soil, sometimes hundreds of feet past the property line. Luna: And then it finds a path into a basement or a crawl space. I remember reading about a house explosion in Southern California — I think it was in 2022? Lucas: That's exactly the case I want to zoom in on. In 2022, a retired landfill in Santa Clarita caused a house explosion that killed two people. The landfill had been closed for decades. Gas had migrated underground, entered the home's foundation through cracks, and accumulated until a spark from the water heater ignited it. The blast leveled the house. Luna: And nobody knew the gas was there because standard monitoring was infrequent — maybe quarterly or even less often. Lucas: Right. Traditional monitoring involves someone driving out to perimeter wells, lowering a handheld meter, and recording the reading. That might happen once a month if the site is well-funded. In between, a leak can develop and go undetected for weeks. That's where IoT sensors change the game entirely. Luna: So what does the IoT version look like? Are we talking about a sensor at every monitoring well? Lucas: Exactly. You install a fixed methane sensor in each well, connected to a wireless transmitter. Most modern deployments use LoRaWAN — low-power, long-range radio. The sensors send readings every 15 to 60 minutes to a cloud dashboard. If methane concentration crosses a threshold — say, 50 percent of the lower explosive limit — the system sends an alert to the landfill operator's phone or email within minutes. Luna: And the sensors themselves — are they the same kind you'd find in a home carbon monoxide detector? Lucas: Similar principle, but built for industrial environments. There are two main technologies. Electrochemical sensors are very accurate at low concentrations and consume very little power — they can run on a single battery for two years. But they degrade over time and need calibration every six months. Infrared sensors, or non-dispersive infrared — NDIR — are more stable and last longer, but they draw more power and are more expensive. For this application, a lot of operators are going with electrochemical because the lower power lets them use solar panels and avoid wiring altogether. Luna: So you can drop a sensor in a well, put a small solar panel on top, and it just talks to a gateway a mile away. That's dramatically cheaper than running conduit and power to each well. Lucas: Exactly. One operator in the Midwest told me that their annual monitoring cost dropped by about 80 percent after switching to IoT. They went from paying a contractor three thousand dollars per quarterly visit to about six hundred dollars a year per well for the cellular data and cloud platform. And they got continuous coverage instead of four snapshots. Luna: And that continuous coverage is what prevents the explosions. But I'm curious — is there a regulatory push behind this, or is it purely voluntary? Lucas: There's increasing pressure from the EPA. The existing rules under the Clean Air Act require landfills above a certain size to collect and control gas, but they don't specifically mandate continuous perimeter monitoring. However, after the Santa Clarita incident and a handful of others, several states are drafting rules that would require real-time monitoring for landfills near residential areas. California is leading that push. Luna: It feels like one of those situations where the technology has been ready for years, but the regulation is only now catching up because of a few tragic events. Lucas: That's a pattern we see across a lot of industrial IoT — the sensor and connectivity tech has been mature for a while, but the market really moves when there's a clear liability or regulatory driver. For landfill gas, the liability is enormous. If gas migrates and causes an explosion, the landfill owner can face wrongful death lawsuits running into tens of millions of dollars. A few thousand dollars in IoT sensors looks like cheap insurance. Luna: And you mentioned earlier that the system can also pick up trends — like gradually rising methane levels that might indicate a crack in the cap or a failing collection well. That proactive maintenance angle is huge. Lucas: Exactly. One of the biggest operational headaches for landfill operators is maintaining the gas collection system — the wells and pipes that actively pull gas out and send it to a flare or a generator. If a well gets clogged or a pipe breaks, methane can start building up and migrating. With IoT sensors in the perimeter wells, you can see that migration happen in real time and pinpoint which collection well is failing. Instead of walking the entire field looking for problems, you get a digital map that tells you exactly where to dig. Luna: That's a huge time saver. And it means fewer workers are exposed to potential hazards during inspections. Lucas: Right. And the data doesn't just protect people — it also helps with environmental compliance. Methane is a potent greenhouse gas, about 80 times more impactful than carbon dioxide over a 20-year period. The EPA requires landfills to report their methane emissions. Continuous monitoring gives them much more accurate data than the old estimation models, and it can actually help them reduce emissions by catching leaks early. Luna: So this is both a safety play and a climate play. I want to ask about the scale — how many landfills in the US could benefit from this kind of system? Lucas: According to the EPA, there are about 2,600 active municipal solid waste landfills in the US, plus somewhere around 10,000 closed or inactive sites. Many of those closed sites have no gas collection at all. So the addressable market is enormous. And the sensors themselves have gotten cheap enough that even a small rural landfill with twenty perimeter wells can retrofit for under twenty thousand dollars. Luna: That's less than the cost of one lawsuit. It feels like a no-brainer from a financial perspective, but adoption still seems slow. What's holding it back? Lucas: I think the biggest barrier is awareness. A lot of landfill operators are still using the same monitoring methods they used twenty years ago. They don't know that IoT sensors have dropped in price and become reliable enough for outdoor deployment. There's also a bit of inertia — 'we've never had an explosion, so why change?' But that line of thinking ignores the fact that gas migration can be completely invisible until it's too late. Luna: And by then, you've got a tragedy on your hands. So education is a big part of solving this. Lucas: Exactly. And episodes like this one can help spread the word — which is part of why we do what we do. Speaking of which, I want to mention something briefly. A couple of dollars a month is genuinely what keeps these shows going — buy me a coffee dot com slash fexingo, if you've gotten something out of them. Luna: Yeah, it really does make a difference. We don't run ads, so listener support is what keeps us independent and focused on topics like this. Lucas: Back to landfill tech — I want to talk about one more real-world deployment that I think is really clever. There's a company called SENSIT Technologies — they make gas detection equipment — and they've been working with a landfill in Ohio that has 120 perimeter wells. They installed LoRaWAN nodes with electrochemical methane sensors, plus temperature and barometric pressure sensors. Because gas migration is heavily influenced by atmospheric pressure — when pressure drops, gas tends to come out of the ground faster. Luna: So they correlate methane spikes with pressure changes. That gives them a predictive model — they can forecast when migration risk is highest and temporarily increase collection well suction. Lucas: Exactly. They built a dashboard that shows a risk score for each perimeter well based on the sensor data and the weather forecast. When the risk hits a certain level, the system automatically adjusts valves on the collection system or sends an alert to operators. That's a level of automation that simply wasn't possible with manual monitoring. Luna: And automation reduces the chance of human error — like forgetting to take a reading or misplacing a paper log. Lucas: Right. The data also feeds into the landfill's gas to energy plant. If migration risk is low, they can reduce collection suction and let the landfill generate more methane for power generation. So it's not just safety — it's also optimizing revenue. That's the kind of win-win that gets operators excited. Luna: I love that. So we're moving from a reactive model — wait for an explosion, then test — to a predictive, automated model. That's the real promise of industrial IoT. Lucas: It is. And the technology is already here and affordable. The question now is whether regulation and awareness will catch up fast enough to prevent more tragedies. Given the pace of state-level rule changes, I'm cautiously optimistic. Luna: Alright, so for listeners who want to dig deeper — where should they look? Lucas: The EPA's Landfill Methane Outreach Program has a lot of resources. And if you're a landfill operator, I'd suggest looking at LoRaWAN-based systems from companies like SENSIT or similar vendors. The upfront cost is trivial compared to the liability. Luna: Good advice. That's all for this episode of Internet of Things with Fexingo. We'll see you next time. Lucas: Take care, everyone.