In Today’s Landfills, Food Is Embalmed for Decades at a Time
Food waste that is thrown into landfills has a dreadful effect on the environment. As rotting food decomposes it releases methane, a greenhouse gas that contributes to global warming. That's not the case with organic food matter in landfills because it...
Compost at the Delaware County's compost plant.
We had been warned of the pervasive power of the stench.
It was a cold, snowy morning in the Catskills, and as our suddenly-too-small car picked its way along the icy road, the acrid, nose-stinging odor of decomposed banana peels, old coffee grounds, and—oh yeah—a melted deer carcass wafted out of our clothing in full force. I began to panic, recalling the Seinfeld episode “The Smelly Car,” when Jerry’s BMW becomes permanently infected with the reek of a valet’s B.O. I wondered if the vehicle I had borrowed from a friend would ever recover from the stinky trials I was now exposing it to.
Earlier that morning, my companions and I had toured the Delaware County landfill, a six-acre dump and compost facility servicing the upstate New York region’s 48,000 residents. Andy Zuk, the compost plant’s affable, middle-aged manager, had received us inside of his bright, tidy office, where he encouraged us to pile our coats, scarves, and sweaters before entering the dark, damp domain where the county’s 70 million pounds of trash is sorted every year. It’s also the space where its food waste is converted into 15,000 yards of light, fluffy, fertile compost.
I told Zuk that I thought I might get chilly and that I’d hang on to my sweatshirt.
“If you’re going to lunch later, and you’re going to be around other people, you might want to reconsider,” he replied.
Andy Zuk shows off the finished compost.
If you’ve never seen an active landfill, it’s more than likely that you’re nowhere geographically close to one. Large-scale dumps are unsustainable in densely packed urban areas, where their insidious odors offend residents’ sensibilities and—more gravely—can cause asthma, cancer, and other serious health effects. Most major cities opt for trucking their trash out West, where there’s a lot more space and a much lower risk of making people ill. New York City closed its last municipal landfill—Fresh Kills on Staten Island—in 2001. Today, the city sends its garbage to far-flung sites in Ohio, Pennsylvania, South Carolina, and Virginia.
On top of impacting human health, landfills have a dreadful effect on the environment: they produce enormous amounts of methane, a greenhouse gas that contributes disproportionately to global warming. Methane’s effect on the atmosphere is 21 times greater than carbon dioxide’s over a 100-year period.
But the source of this methane isn’t something toxic. It’s rotting food. It might seem like an apple core or cheese rind thrown in with the trash would break down quickly, but the opposite is true. Sealed up in plastic garbage bags and buried under pound-upon-pound of plastic, glass, and paper, these scraps begin to break down at a rate far slower than you might think. Those plastic bags that contain our food waste limit their exposure to oxygen and pests, the two factors that make short work of food waste when combined. Instead, in this dark, anaerobic environment, decomposition happens very slowly, and the food releases far too much methane throughout the process. Deprived of oxygen, the food barely breaks down. The results can be found at the bottom of old landfills, where you’ll find pristine heads of lettuce and rolls that look good enough to make a sandwich.
Some insight into this mysterious process was provided in 1992, when the archaeologist, William J. Rathje, published his book Rubbish! The Archaeology of Garbage. The now deceased Rathje was a professor at the University of Arizona in Tucson, where he founded the Garbage Project in 1972. For over 20 years, he and his teams of student volunteers excavated more than 21 active landfills, approaching these modern-day refuse piles almost in the same approach that archaeologists have always investigated ancient trash heaps—like giant mounds of evidence of human culture and their habits, both good and bad. But the data that the garbage project amassed didn’t just further understanding of humans’ garbage habits; it also shed light on some of the science behind trash. Namely, that organic matter cached in landfills doesn’t really decompose. It mummifies. In a 1992 interview with the New York Times, Rathje recalled an order of guacamole he recently unearthed. "Almost as good as new, it sat next to a newspaper apparently thrown out the same day. The date was 1967.”
Above, non-compostable waste travels down a conveyor belt on its way to the trash compactor.
Zuk, the compost plant manager, told me that he was familiar with the embalmed-food phenomenon. The landfill over in Binghamton, he said, was thinking recently about trying to do some on-site composting. As research, they dug around in their landfill to see what was down there.
“They found a 10-year-old pack of hot dogs, good as new,” Zuk said.
But you won’t find any ageless food scraps at the bottom of the Delaware County landfill, because you won’t find any food in there at all. In 2005, the dump built its state-of-the-art composting facility, a three-acre building where every single bag of residents’ trash gets sorted by machines. The food waste is spun out and composted in a superefficient bioreactor that converts organic materials into compost in three days with the help of these machines. Recyclables are recovered, and the remaining garbage gets compacted before being added to the landfill. Sixty-five percent of what residents bring in to the plant is compostable, but only 35 percent of waste at the site goes into the landfill. The trash sorting is the source behind the all-powerful odor of garbage, but the smell dissipates throughout the composting process, resulting in a completely odor-neutral product.
Above, a huge rotating drum filters out non-compostable waste, which gets compacted before going to the landfill.
Zuk led us to that bioreactor, a 180-foot-long tube with a 14-foot diameter that rotates 24 hours a day. Inside, insects and microorganisms break down the food waste, a process that produces immense heat—the bioreactor’s contents regularly reach 180 degrees—which, in turn, accelerates the breakdown process. Within three days, even the largest food items are totally decomposed.
“I’m gonna tell you right now, I threw a whole deer in there once. At the end you didn’t see anything but the clean bones,” Zuk recalled.
The compost produced is then aged in 14 huge bays—concrete areas where large quantities of compost are stored—for a minimum of 90 days before being sold to local landscaping and public works companies for $10 per yard, which brings revenue back to the plant.
“You’re taking garbage and turning it into money,” Zuk said.
While neighboring Montgomery, Otsego, and Schoharie counties truck their residents’ garbage out West, Delaware’s compost plant has extended the life of its landfill by at least 20 years. In the future, the dump might even excavate its older, overgrown trash heaps and run those through the bioreactor, adding even more longevity to the site.
“In my opinion, it’s the Cadillac of composting facilities,” Zuk said of his plant.