This story by MIT Environmental Solutions Journalism Fellow Paul Ruffins was originally published in Streetcar Suburbs News, where it appears with additional photos. It is the first in a series of articles exploring landfills, food waste, and methane emissions in Prince George's County and neighboring jurisdictions.
Imagine that it’s March 2024, and spring cleaning has left you with three broken bicycles, two dead car batteries, and an unlabeled plastic jug of pesticide or paint thinner. The quickest way to dispose of everything is to drive to the county’s Brown Station Road Landfill in Upper Marlboro. At this time, it consists of a closed section, A, that is 148 acres, and an active section, B, that is 140 acres—as large as 106 football fields.
When you arrive, there are two lines of traffic outside the scale house. In the left lane are commercial vehicles and garbage trucks, waiting to be weighed. The right lane is for private vehicles. Both lanes could be headed to several designated drop-off points for televisions, appliances, scrap metal, recyclables, household hazardous waste and other items the county doesn’t want landfilled. The bikes and battery will be recycled for their steel and lead. Your jug of unidentified chemicals will go to a company licensed to dispose of hazardous waste.
The per-ton tipping fee for commercial vehicles is $77 for general trash, up from $59 in 2021. Your load is free, but your license has been carefully checked to prove you are a county resident. Prince George’s County is running out of landfill space, and it rejects all loads from outside its borders.
What’s more, if you were to do that same spring cleaning today, you’d have to take your pesticide, car battery, and other household goods to a separate, temporary drop-off site at the Brown Station Road Convenience Center. Nine of section B’s 11 cells are already full, and the Household Hazardous Waste Site is currently closed so that the county can build a section C.
In 1977, the county also had municipal landfills in Bowie, Beltsville and Laurel. By 2017, only Brown Station Road remained operational, though there are still a few specialized landfills accepting materials such as construction rubble.
Like Prince George’s County, jurisdictions across the nation are fighting to divert materials from their landfills to increase recycling, prevent toxins from seeping into the air or groundwater, or simply to save space. Recently, these jurisdictions have also been motivated by the threat of global warming, and one of the biggest problems is food disposal.
When organic materials like meat, vegetables or leaves decompose, they can break down into different substances under different conditions. “Landfills have very little air or oxygen in them,” explains Dr. Xinrong Ren, a physical scientist at the National Oceanic and Atmospheric Administration’s air resources laboratory in College Park. “This is partly because they are constantly being compacted by heavy earth-moving equipment.” As a result, food and other organic matter that would produce carbon dioxide (CO2) if they decomposed in the open air produce methane when buried in landfills.
Along with coal and oil, methane—the main ingredient in natural gas—is one of the most common fossil fuels. One reason it’s so popular is because it’s the cleanest of these fuels. Every day, millions of people cook on gas stoves without ventilation. Running a gasoline-powered generator indoors, in contrast, would generate lethal amounts of carbon monoxide. Many coal and oil-fired power plants have converted to natural gas to lower their emission of particulates, sulphur dioxide and mercury.
Natural gas is not a perfect fuel, though: It combines with ground-level ozone to produce smog, which exacerbates asthma and other respiratory illnesses. However, a bigger hazard is that methane is a powerful driver of global warming.
The MIT climate portal explains, “Energy from the sun enters the Earth as a mix of visible, ultraviolet and infrared light, but it leaves the earth and travels back into outer space almost entirely as infrared energy or heat.” The main gases in the atmosphere, oxygen and nitrogen, don’t interact with infrared. However, greenhouse gases (GHGs) like carbon dioxide, methane and nitrous oxide absorb the infrared light leaving the earth and then vibrate that energy back into the atmosphere as heat. How much heat they trap depends on their shape and how fast they break down. CO2, the most common GHG, is one carbon atom tightly bound to two oxygen atoms and can last for centuries.
Methane (CH4), the second most abundant GHG, is one carbon atom relatively loosely bound to four hydrogen atoms. Therefore, infrared light causes CH4 to vibrate much more than CO2, so it traps much more heat, but it breaks down in approximately 10 years. Scientists rank greenhouse gases by comparing how much heat the same amount of CO2 would trap in 100 years. At any given moment, methane traps about 80 times more heat than CO2, which works out to approximately 28 times more over its shorter lifetime.
Unlike coal or oil, which develop from organic matter over thousands of years, methane can be produced very quickly. In a process called enteric fermentation, ruminants, such as cows, cattle and sheep, constantly burp out methane as they digest their food. Methane is also produced from chicken and pig manure, as well as human waste processed by water treatment plants.
By taking atmospheric measurements using aircraft, Ren and researchers from the University of Maryland, Purdue University and other institutions helped the Maryland Department of the Environment estimate that in 2021, landfills accounted for 44% of the state’s methane emissions. This is almost as much as the next three sources—agriculture (17%), the natural gas industry (16%) and wastewater management (15%)—combined.
“We simply must get food out of our waste stream,” says Michele Blair, the City of Laurel’s environmental programs manager. “Food waste and products contaminated with food, like pizza boxes and paper towels, make up 35% of what isn’t recycled. Landfilling food is also very expensive because it’s heavy, and by the end of 2025, the tipping fee for trash is expected to go up to $85 a ton. Worst of all, food accelerates global warming.”
If leaves, grass, trees or garden clippings were buried in a landfill, they would also produce methane. So why do experts like Blair and Ren believe that food is the problem? Maryland’s towns and cities have been picking up and diverting yard waste from landfills ever since the Maryland Recycling Act of 1988, so food is the main organic material left.
The next article will explore the local options for disposing of food without disrupting the environment.
