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.