Back
Landfills are a major problem for the climate: They’re the United States’ third-largest source of methane, a greenhouse gas that traps 80 times as much heat as carbon dioxide in the short term. Last year, the federal government was poised to start reining in these emissions: In July, the Environmental Protection Agency announced that it would release new regulations to better detect and prevent methane leaks from landfills.
The Trump administration, which has announced its intention to cut the EPA’s budget by 65% or more, seems unlikely to follow through on these plans or any other policy limiting landfill emissions.
But in the absence of federal leadership, states like Michigan, Oregon, Colorado, and California are moving forward with their own plans. Regulatory efforts are underway among these climate leaders to implement stricter rules for landfill operators and require the use of novel technology, like drones and satellites that monitor leaks.
“These state regulations could be hugely impactful,” said Elizabeth Schroeder, the senior communications strategist at Industrious Labs, a nonprofit working to transform heavy industry. They not only have the potential to make a real dent on greenhouse gas emissions, Schroeder said, but could also set a national example for other states looking to curtail methane pollution.
Currently, the EPA requires landfill operators to cover trash to minimize odor, disease risk, and fire — a practice that also minimizes methane leaks. This usually looks like a layer of dirt or ash, followed by tarps. Operators of large landfills must also install extraction systems, networks of pipes that collect methane and other gases from inside the landfill. The extraction systems then pump these emissions to burn off at flares or, increasingly, to biogas energy projects. However, landfills are dynamic systems — over time, as waste breaks down and shifts, cover develops holes and pipes crack.
Maintenance is often imperfect. An analysis by the Environmental Defense Fund found that between 2021 and 2023, more than one-third of landfills had at least one violation of EPA standards. Operators of landfills that exceed a specific emissions threshold are supposed to conduct quarterly “walking” surveys for leaks. But experts say that these surveys are infrequent and often miss large portions of the landfill.
States have an opportunity to step up those standards — not only by lowering emissions limits but by improving the maintenance and monitoring of landfills, said Tom Frankiewicz, the waste-sector methane expert at climate-focused think tank RMI. “While we would love to see all this done comprehensively in one national-level regulation, it’s states that are taking the lead on deployment of advanced technology and setting new best practices for landfills.”
In 2010, California became the first state to develop standards for landfills that were stricter than federal rules. Those included a lower emissions threshold at which landfills had to install gas collection systems and a requirement that operators enclose flares so that the methane burns more efficiently. Other states, including Oregon and Washington, followed suit and in some respects even surpassed California, said Katherine Blauvelt, the circular-economy director for Industrious Labs. But despite this early progress, landfills in these states and elsewhere continue to spew methane and undermine climate goals.
Now, though, Colorado has taken the lead on a new generation of landfill emissions regulations. The state is developing what some experts are calling a first-of-a-kind program for monitoring and responding to methane leaks from landfills. As part of the initiative, Colorado plans to implement remote-sensing technologies, including fly-overs and satellites, to detect methane leaks, which operators would then be required to address.
“Colorado would be the first state to incorporate that into a rule where, instead of relying on voluntary follow-up, there would actually be requirements around mitigating emissions that are detected,” said Ellie Garland, a senior associate focusing on methane policy at RMI. A draft rule will be publicly available in April, with a final vote expected in August.
In addition, Colorado’s Department of Public Health and Environment is considering additional requirements for landfills that include stricter rules for the maintenance of cover and a lower threshold at which landfills are required to report and control emissions, Garland said. Currently only 15 of the state’s about 50 active landfills do this, although Colorado began requiring 35 more landfills to begin reporting emissions starting on March 31, said Clay Clarke, the manager of the climate change program at the Colorado Department of Public Health and Environment. Not all landfills are required to control emissions. That’s because smaller landfills don’t generate enough gas to collect and flare. Under proposed regulations, many of these landfills would need to pipe gas to biofilters — a system that uses microorganisms to digest methane.
Meanwhile, the California Air Resources Board is working to update its landfill emissions regulations. Under CARB’s anticipated timeline, these will take effect in 2027. Last December, the agency held a workshop to discuss potential new rules. Those included a lower safe limit for methane emissions, limits on how long operators can turn off their gas collection systems for landfill maintenance, and stricter rules for collecting gas at closed landfills. Under current regulations, landfill operators must collect gas for only 15 years after a landfill closes even though the area can continue to leak methane for 30 years or more. The agency is also considering regulations that would require some operators to install automated well-tuning technology that monitors and adjusts the gas-extraction system in real time.
One of the most promising new regulations CARB is considering is a “super-emitter” program for landfills, Blauvelt said. The EPA defines a super-emitter event as a plume of methane leaking at a rate of more than 100 kilograms per hour. In 2019, NASA scientists estimated that these highly concentrated leaks account for one-third of California’s methane emissions.
Between 2020 and 2023, CARB partnered with the University of Arizona and the nonprofit Carbon Mapper to track down super-emitter events by flying over landfills in planes equipped with sensors that can detect methane plumes. If Carbon Mapper identified a leak, it notified CARB, which would get in touch with the landfill owner. However, operators weren’t required to take action. Later analyses found that operators fixed about half of the reported leaks.
Updated rules could require landfill operators to swiftly respond to methane plumes. The program would be similar to the super-emitter program already in place for California’s oil and gas industry. That program requires operators to follow up with on-the-ground monitoring within five days of learning about a leak, come up with a repair plan 72 hours later, and fix the leak within two to 14 calendar days, depending on its severity.
The state is also looking into other remote-sensing technologies, like drones and on-the-ground infrared monitors, which would provide a more continuous and finer-resolution picture of methane emissions.
California emits the second largest share of greenhouse gases in the U.S. A recent Industrious Labs analysis found that if the state were to adopt these stricter regulations, it could reduce its landfill emissions 22% by 2030 and 64% by the end of the century.
Other states are renewing their efforts, too. In Oregon, newly proposed Senate Bill 726 would require landfill operators to deploy commercially available drones and advanced monitoring technologies (including satellite and airflight) to detect methane plumes across landfills.
Meanwhile, in Michigan, a climate bill passed in 2023 contains elements that could lead to landfills adopting better monitoring and detection. Senate Bill 271, which aims to accelerate the state’s transition to clean energy, identifies landfill biogas as a potential low-carbon fuel. “While the inclusion of recovered landfill gas as a clean energy source has come under scrutiny, there is a major silver lining,” Blauvelt wrote in an email. “Vital” language in the bill mandates that landfill operators collecting biogas use “best practices for methane gas collection and control,” as determined by Michigan’s Department of Environment, Great Lakes, and Energy.
The department has yet to lay out what those “best practices” are, but better landfill cover, automated well-tuning technology, and advanced monitoring technology are all on the table, Blauvelt said.
“Given that Michigan is among the top ten states for methane emission from landfills, the potential to dramatically reduce methane and other harmful co-pollutants is enormous,” Blauvelt wrote in an email.
A 2024 analysis by Industrious Labs projected that if every state were to adopt these best practices, it could lead to a 56% drop in landfill methane emissions by 2050. Experts hope that as these climate leaders adopt stricter rules, more states will step up. In 2010, California showed that this ripple effect is possible, Blauvelt said. “The great news about this is, the solutions are known. The technology is sitting on the shelf.”
.svg)
