Methane emissions from landfills — one of the largest sources of greenhouse gas emissions in the United States — could be reduced through stronger regulations and better emissions monitoring, according to a new report by the Environmental Integrity Project, a Washington environmental organization.
The report says that, to reduce emissions, the U.S. Environmental Protection Agency needs to require more gas-collection systems at landfills, more monitoring and accurate reporting of emissions and to encourage more composting, recycling and reduction in the waste stream by consumers.
Municipal landfills — solid-waste facilities that receive household garbage — account for 14% of all methane emissions, according to the EPA’s annual greenhouse gas inventory.
Methane — generated from the breakdown of organic waste — is about 80 times more effective at warming the planet than carbon dioxide over 20 years.
Methane’s relatively short life — it remains in the atmosphere for just over a decade, while CO2 remains for centuries — means that a significant reduction in methane emissions could have an almost immediate impact on curbing climate change.
In 2021, U.S. municipal waste landfills released 3.7 million metric tons of methane — equal to the annual greenhouse gas emissions of 66 million gas powered cars or 79 coal-fired power plants, according to the EPA’s greenhouse gas equivalency calculator.
“Landfills are a significant contributor to a very powerful greenhouse gas,” said Leah Kelly, an attorney with the Environmental Integrity Project who was an author of the report. “The EPA needs to update their emissions standards in order to further reduce that pollutant from landfills.”
The report notes that some states — including California and Oregon — require the installation of gas-collection systems at more landfills required under federal regulations. Of the 10 states with the highest methane emissions from landfills, California has the highest percentage of landfills with gas-collection systems and the lowest rate of landfill methane emissions, according to the report.
The report said the EPA’s methods to estimate methane emissions could be “significantly underestimating” those emissions.
A National Academy of Sciences report in 2018 came to a similar conclusion, placing “low confidence” in EPA estimates for landfill methane emissions, calling the agency’s method of making those estimates “outdated” and “never field-validated.”
Current emissions estimates are based largely on the amount of waste at a landfill. But recent “top-down” measurements of methane emissions from airplanes have shown actual emissions are significantly higher than official “bottom-up” estimates in some cases.
“Emissions are not necessarily related to the amount of waste in place,” said Jean Bogner, a University of Illinois Chicago emeritus professor and coauthor of the National Academy of Sciences report. “A combination of top-down and improved bottom-up strategies are needed.”
Last July, the Environmental Integrity Project, the Chesapeake Climate Action Network,and the Sierra Club sued Michael Regan, the EPA administrator, for not updating the agency’s methods for estimating emissions of air pollutants from landfills, as required by law.
The groups said the EPA hadn’t updated those methods since 1998 despite knowing since at least 2008 that they were relying on flawed methods that tend to underestimate emissions. The federal Clean Air Act requires the agency to reevaluate its methods every three years.
In a proposed consent decree in February, the EPA said it would reevaluate the landfill emissions estimate methods.
The Environmental Integrity Project found that more than half of all U.S. landfills are in communities with a higher percentage of people of color or low-income people than the national average.
In Uniontown, Alabama, whose population is 98% Black and 64% below the poverty line, people complain about ”odors, nausea, headaches and other illnesses” from a landfill that gets 93% of its garbage from out of state, according to the report.
It also said one of the top methane-emitters in Maryland is a city-owned landfill in Baltimore near a community that’s 60% Black or non-white Hispanic.
The largest-emitting landfill in the country in 2021 was the Sampson County Disposal, a privately owned landfill in Roseboro, N.C., according to EPA data cited in the report. Landfill operators previously have told Inside Climate News they have taken measures to reduce emissions and thought the EPA’s models to estimate emissions were incorrect.
Florida was the only state with three landfills ranked among the top 10 emitters, in Brevard County, West Palm Beach and Polk County. That state’s total emissions of 239,792 metric tons were third, behind Texas (389,437 metric tons) and California (260,214 metric tons).
Ohio had two landfills among the top 10, in Dover and Amsterdam. That state’s total emissions of 188,032 metric tons were fifth, behind Georgia (188,349 metric tons). Illinois was ninth, with 111,627 metric tons, according to the report.
