Is the EPA about to get serious about methane pollution from landfills?

Landfills are the third-largest source of methane emissions both in the U.S. and globally. These emissions heat the atmosphere at about 80 times the rate of carbon dioxide over 20 years, but the methane that rises from the decomposing food and organic waste that ends up in landfills has thus far received much less attention in the fight against climate change than methane emissions from oil and gas infrastructure.

Under the Clean Air Act, the U.S. Environmental Protection Agency is tasked with devising regulations to lower methane emissions, but experts say its rules for landfills fall egregiously short of achieving the necessary reductions. They point to stricter policies adopted by a growing number of states that could provide a model for establishing a stronger nationwide standard. The opportunity to implement such a standard is arriving soon: An EPA spokesperson told Canary Media on Tuesday that the agency is ​“actively working on revisions” to its regulations for how landfills monitor and capture methane emissions. It expects to issue a draft of the new rules sometime in 2025.

The current EPA rules, which were established in 2016, require any landfill designed to hold 2.5 million metric tons or more to install a gas collection system — essentially a network of pipes that suck methane out of garbage piles to prevent it from heating the atmosphere. The gas is then burned, releasing carbon dioxide, which is less damaging to the climate than the rapid warming brought on by methane. In some cases, methane is burned off at the landfill site, either underground or using flares. A number of landfills use the gas to produce electricity or refuel garbage-collection vehicles, or it may even be pumped into existing natural-gas networks.

The EPA also requires quarterly surface-emissions monitoring. A worker must walk the perimeter of a landfill with an air sensor and cross the landfill at about 100-foot intervals. If methane is measured at above 500 parts per million, it is considered an exceedance, and the EPA requires the landfill operator to take corrective action, such as adding additional soil coverage that helps with oxidation of organic material. The operator has to go back and measure again to ensure methane emissions have decreased.

These rules have gaps that experts say needlessly result in high emissions. First, landfills that are small enough to go without a gas collection system can still produce significant amounts of methane. When landfills do have gas collection systems, the pipes themselves can crack and leak, and the EPA does not have standards for detecting these kinds of problems. Furthermore, monitoring for methane on the landfill surface is prone to human error, and leaving 100-foot openings where no monitoring takes place inevitably means methane plumes go undetected.

Recent reports have revealed that landfill methane emissions are being undercounted, and exceedances are commonly found when the EPA conducts on-site inspections.

A study published in March in the journal Science concluded that landfill methane emissions were on average 40 percent higher than what’s reported to the EPA. The study, which surveyed over 200 active U.S. landfills using airborne sensors to detect methane plumes, found that 52 percent of surveyed landfills had observable emissions, and more than half of those plumes continued for months or years.

In May, Industrious Labs, a group that works to clean up industrial sources of climate pollution, analyzed EPA inspection reports from 29 landfills and found more than 711 methane exceedances above the 500 ppm limit. In many cases, the landfill operators had not detected any exceedances when conducting standard quarterly monitoring.

Katherine Blauvelt, circular economy director for Industrious Labs and an author of the report ​“The Hidden Cost of Landfills,” said that the tools exist to avoid landfill methane emissions, but ​“they’re not being deployed across the country at scale.”

Approaches vary by state, but best practices have emerged

Some states are lowering the threshold at which landfills must install gas collection systems based on the amount of waste in place and the amount of methane emitted. This has required more medium-sized landfills to install gas collection. Others require monitoring along tighter intervals and have expanded the scenarios in which landfill operators must take corrective action to lower methane emissions. In addition, states have made landfill operators monitor their gas collection systems for leaky pipes, standing water, and other maintenance issues that can cause methane to escape. And several states are phasing out open flares and requiring landfills to use enclosed flares that burn a higher percentage of methane.

These best practices emerged in California, the first state to establish stricter landfill methane rules in 2010. As the most populous state in the nation, it still has the second-highest total amount of methane emissions from landfills, but its per capita emissions rate in 2021 was about half that of the other top landfill methane emitters, Texas, Florida, Georgia, and Ohio — none of which have rules for reducing landfill methane.

After California demonstrated that tougher methane controls at landfills can have a sizable impact, Oregon, Maryland, Washington, and Michigan followed suit.

Oregon

Adopted in 2021, Oregon’s rules broaden the types of landfills that must follow methane protocols to include every type except hazardous waste. Federal rules apply only to municipal solid waste landfills that handle household and commercial waste.

The state has also lowered the size at which a landfill is required to install a gas collection system. ​“We’re regulating landfills down to 200,000 tons of waste in place,” said Heather Kuoppamaki, a senior air quality engineer at the Oregon Department of Environmental Quality who helped write the rules.

Kuoppamaki is most proud of the changes to landfill monitoring requirements. When workers in Oregon perform quarterly monitoring, they cover more of the landfill, having to make a path across it every 25 feet rather than every 100 feet. At any location where monitors detect methane at half the legal limit of 500 ppm, workers then create a small grid area around that location to conduct additional monitoring.

“That’s capturing the small problems before they become big problems,” Kuoppamaki said. 

Maryland

In Maryland, landfills account for about 40 percent of methane emissions. Maryland’s landfill methane rules, finalized in 2023, take an approach similar to those in California and Oregon. ​“If EPA were to just adopt Maryland’s model wholesale, it would be a significant improvement on EPA’s existing regulations,” said Leah Kelly, a senior attorney with the nonprofit Environmental Integrity Project.

Kelly highlighted the adoption of leak detection and repair for gas collection equipment, which is currently not required at all by the EPA. For any part of the gas collection system located aboveground, workers will have to conduct regular air monitoring and take action if any leaks are found. ​“That’s one of the ways in which the state model is significantly better than the federal regulations,” Kelly said.

Washington

In May, Washington became the most recent state to finalize rules for landfill methane. An estimated 26 landfills, a majority of them publicly owned, will be subject to new methane controls, according to a spokesperson from the Washington Department of Ecology.

The EPA estimates that it will cost a midsize landfill about $1.3 million to install a new gas collection system. Under the Washington rule, active landfills will have 18 months to comply, while some retired landfills also required to install a system will have 30 months. To support these efforts, the state has established a $15 million grant program.

Washington also gave the go-ahead for drone-based methane monitoring. While drones may be used in other states with prior approval, Washington is the first to preemptively approve drone usage.

Michigan

Michigan takes in a lot of trash from other states and Canada, which is partly why its landfills rank sixth in the nation for methane emissions. Rather than passing a broad set of rules, Michigan started by tackling issues specific to its landfills.

After the state environmental agency noticed that water buildup inside the wells and pipes of gas collection systems was making them ineffective, the state passed a law to require landfill operators to monitor for this. The state has also passed a law stipulating that monitoring for methane begin within 100 days of waste being dumped at a landfill — earlier than the EPA or most other states require.

In 2022, Michigan passed a bill mandating best practices for landfill operations, but the details have yet to be finalized. ​“This should be an absolute top priority for the state, federal, and local government,” said Christy McGillivray, political and legislative director of the Sierra Club’s Michigan Chapter. McGillivray added that she is ​“pushing to make sure that we are dramatically working to decrease gas coming off of landfills, not just capture it.”

An opportunity for a stronger federal approach

In a statement to Canary Media, the EPA said it is looking at ​“new and emerging technologies and new approaches that could be implemented” to reduce landfill methane. The commitment to update rules is welcome news to Blauvelt. ​“The EPA has got to lead and make sure we don’t have this patchwork that’s really inequitable,” she said, adding that the landfills responsible for the most methane emissions are largely located in states that do not have their own standards. The EPA, she noted, could also implement other solutions that would be more effective on a national scale, such as a super-emitter program similar to what the agency has rolled out for the oil and gas industry to detect large methane plumes in real time.

“We have now airborne remote-measuring technology that is across the globe” and detecting methane plumes, Blauvelt said. She wants the EPA to certify the use of technology such as satellites and drones for methane-emitting landfills and require operators to take immediate action. ​“Technology has advanced and federal regulations have not caught up to those advancements.”


Correction: A previous version of this story stated that the EPA could release a draft of revisions to its regulations for how landfills monitor and capture methane emissions as early as August. We regret the error.