About half of all trash generated in the United States ends up in a landfill. That amounts to 146 million tons per year, or roughly 4.9 pounds per person per day before recycling and composting divert some of it. What actually fills those landfills is a mix of everyday household items, food scraps, packaging, clothing, and materials that were never designed to break down underground.
The Biggest Categories by Volume
Municipal solid waste, the official term for everyday trash, totaled 292.4 million tons in the U.S. in 2018, the most recent year with comprehensive EPA data. Of that, 146.2 million tons were landfilled. The rest was recycled, composted, or burned for energy recovery.
Food waste is the single largest component, making up about 24 percent of what gets buried in landfills. That includes uneaten meals, spoiled produce, restaurant scraps, and food processing byproducts. Paper and paperboard come next, followed by plastics, yard trimmings, metals, wood, glass, and rubber or leather. Textiles alone account for 5.8 percent of total waste generation, representing 17 million tons per year. Much of that is clothing and footwear that gets tossed rather than donated or recycled.
Food Waste and Methane
Food scraps create an outsized environmental problem once they’re buried. In a landfill, organic material doesn’t decompose the way it would in a backyard compost pile. Instead, it breaks down without oxygen in a process that produces methane, a greenhouse gas far more potent than carbon dioxide over a 20-year period. Municipal solid waste landfills are the third-largest source of human-caused methane emissions in the United States.
Because food decays faster than other buried materials, it generates a disproportionate share of that methane. An estimated 58 percent of the methane that escapes from landfills into the atmosphere comes specifically from food waste. That single category of trash, the banana peels and leftover pasta and expired yogurt, is the dominant driver of landfill greenhouse gas emissions.
Plastics, Glass, and Metals
Plastics are everywhere in landfills: bottles, food containers, packaging film, toys, household goods. A plastic bottle takes an estimated 450 years to break down when exposed to air and sunlight. Buried in a landfill, where conditions are dark, compressed, and low in oxygen, the timeline stretches even further. In practical terms, every plastic bottle ever landfilled still exists in some form.
Glass and aluminum are even more persistent. Glass jars and bottles may take one to two million years to decompose, and aluminum cans are estimated at a million years or more. These materials are essentially permanent once buried. The irony is that both glass and aluminum are infinitely recyclable, meaning they can be melted down and reformed without losing quality, yet enormous quantities still end up underground.
As plastics slowly fragment under the chemical and physical stress inside a landfill (fluctuating temperatures, acidic leachate, microbial activity, gas generation), they don’t disappear. They break into smaller and smaller pieces called microplastics. These tiny fragments can be carried out of the landfill through leachate or even through the air, spreading into surrounding soil and waterways.
Clothing and Textiles
The 17 million tons of textiles generated each year include everything from worn-out jeans to bedsheets to shoes. A leather shoe takes up to 45 years to break down. Synthetic fabrics made from polyester or nylon behave like plastics and persist for centuries. Fast fashion has accelerated this problem: cheaper clothing wears out faster and gets replaced more often, and much of it is made from materials that landfills cannot process in any meaningful timeframe.
What’s Banned but Still Ends Up There
Certain items are technically prohibited from municipal landfills, including paints, chemical cleaners, motor oil, batteries, and pesticides. These restrictions exist because such materials can leach toxic substances into the surrounding environment. In practice, plenty of banned items still arrive in household trash. Old electronics are a particular concern. Phones, laptops, and televisions contain lead, mercury, cadmium, and other toxic heavy metals. The World Health Organization classifies e-waste as hazardous, noting that it can release up to 1,000 different chemical substances into the environment, including known neurotoxicants like lead and mercury.
When these items end up in a landfill rather than a proper e-waste recycling facility, their toxic components slowly leach into the waste mass over time.
What Happens to Buried Waste
Landfills are designed with liner systems to contain waste and prevent contamination of groundwater. But the mixture of rain, moisture, and decomposing trash produces leachate, a liquid that percolates through the waste and picks up contaminants along the way. Leachate typically contains dissolved organic matter, heavy metals, ammonia, and various synthetic chemical compounds. Ammonia is particularly stubborn: unlike some pollutants that diminish as the landfill ages, ammonia concentrations remain high indefinitely, making it a long-term contamination risk.
The core problem with landfills is that most of what goes into them doesn’t actually go away. Organic waste generates potent greenhouse gases. Plastics fragment into microplastics that migrate beyond the landfill boundary. Metals and glass sit unchanged for geological timescales. And toxic chemicals from electronics and household products accumulate in leachate that must be managed for decades after a landfill closes. The roughly 4.9 pounds of waste each American generates daily adds up to a permanent deposit that future generations will inherit.