This automated tool helps tackle methane emissions from landfills

When Melinda Sims first started LoCI Controls, a company that provides landfills with real-time data on methane collection, she wasn’t trying to address climate change. It was 2012, and methane — a super-pollutant that traps 80 times as much heat as carbon dioxide over a 20-year time period — wasn’t yet a part of the national conversation around lowering emissions. ​“CO₂ reduction was the main focus,” Sims said. ​“Nobody was talking about methane or landfills.”

At that time, Sims was a graduate student studying mechanical engineering at the Massachusetts Institute of Technology. She got the idea for the company after a major landfill operator asked for her help with a particular conundrum. The company was trying to capture methane — which seeps from landfills as food scraps and other organic matter decompose — and use it to generate energy, but it couldn’t extract enough of the gas to fuel its on-site power-plant engines.

Sims was able to identify the problem: The landfill’s extraction system, a network of pipes and wells that collect methane and other gases, was leaking. ​“Landfills are dynamic,” Sims said. Waste decomposes and shifts, temperatures vary, atmospheric pressure rises and falls — all these changes cause pressure inside the extraction system to fluctuate, and methane to seep out.

As Sims researched the issue, she realized that the operator who had enlisted her help wasn’t an outlier. ​“It wasn’t a single landfill problem,” Sims said. Operators are supposed to regularly monitor and adjust pressure inside the extraction system, but that typically happens only once per month — not nearly often enough to catch leaks. In response, Sims and fellow MIT graduate student Andrew Campanella developed a technology that does this work remotely.

A decade later, we know that landfills are the third-leading source of methane emissions. As state and federal regulators tighten landfill-emissions requirements, automated well tuning has become an important tool in the effort to reduce this source of greenhouse gas emissions — and LoCI Controls is at the forefront of that effort.

After food scraps get thrown in landfills, they are buried under dirt and other waste, then covered in tarps. Over time, aerobic bacteria, which feed on oxygen and organic matter, munch on this food, depleting the oxygen inside the pile of trash. This frees up room for methanogens, which eat the carbon dioxide produced by aerobic bacteria and pump out methane.

Under the Clean Air Act, the U.S. Environmental Protection Agency places limits on how much methane landfills can leak. To meet these requirements, landfills have to install extraction systems, which pump methane to locations where it is burned or funneled on to energy projects. But experts say that meeting EPA requirements is largely an honor system. In addition to monitoring the extraction system on a monthly basis, operators typically perform manual inspections of a landfill by walking around its surface with a handheld emissions detector. One analysis of landfills across eight states found methane leakage that exceeded legal limits at 96 percent of them. Inspections of major landfills around the country have revealed cracked, aging extraction systems.

LoCI Controls places sensors at wells whose purpose is to vacuum methane to the surface for collection. Those sensors continuously monitor conditions within the extraction system, including pressure, temperature, and composition of the gas collected, then send that data to a server where an algorithm automatically makes adjustments to valves on the well. ​“That’s tens of thousands more measurements than a landfill would typically have,” said Peter Quigly, the CEO and chair of LoCI Controls. 

This technology also acts as an ​“alarm bell” for cracks and leaks elsewhere in extraction systems, according to RMI, a climate-focused think tank. If LoCI Controls adjusts the valves on the wellhead, but the pressure in the system doesn’t change, that signals a problem and sends an alert to the operator, Sims said.

LoCI Controls compared real-time emissions data collected by its sensors to data in the American Carbon Registry, and found that landfills that installed automated well tuning saw methane capture increase by 15 to 25 percent.

“If it’s truly a 15 to 25 percent increase in gas collection, that’s kind of a game changer,” said Tom Frankiewicz, the waste-sector methane expert at RMI.

Frankiewicz is excited about the role automated well tuning can play in methane emissions reduction. Ultimately, however, it’s just one piece of a puzzle that has to involve other forms of emissions monitoring, including remote sensing from satellites, planes, and drones. LoCI Controls’ ability to monitor methane is limited to the gas-extraction system. The technology doesn’t detect emissions from the landfill’s working face, where waste is actively being deposited, or from damaged tarps. ​“It’s not giving you a full picture of the entire landfill, but it’s giving you a much more accurate picture of the gas-extraction system and the amount of gas you’re collecting,” Frankiewicz said.

Frankiewicz imagines a future in which landfills are routinely monitored by a suite of technologies: Satellites will detect ​“super-emitters,” landfills leaking upwards of 1,000 kilograms of methane per hour; drones will provide higher-resolution data, zooming in to identify the origins of such a leak; and automated well tuning will offer continuous information on the extraction system.

LoCI Controls isn’t the only company to develop automated well tuning — shortly after its founding, Apis Innovation created a similar tool. So far, however, this technology has mainly been adopted by larger landfills that turn methane into biogas that they use on site or sell. These landfills have a financial incentive to collect as much gas as possible.

Frankiewicz believes that automated well tuning will only be scaled up if it becomes a regulatory requirement. Some states are taking steps in this direction. Through a new methane-emissions monitoring initiative, Colorado is considering mandating automated well tuning along with other technologies, Frankiewicz said. Last year, California announced that it was considering stricter emissions rules for landfills — potentially including the requirement that landfills collect real-time data. Meanwhile, Orange County, California, and Dane County, Wisconsin, are implementing automated well tuning at municipal landfills, according to RMI.

“This is very scalable,” Frankiewicz said. ​“You’ll see it spread if the regulatory landscape changes.”