Garbage Land: On the Secret Trail of Trash (13 page)

When the aerobic microbes die off and oxygen is depleted, the anaerobic team takes over. The first wave of anaerobic bacteria produces enzymes called cellulases, which break organic material into smaller molecules, like sugars and amino or fatty acids. Next, acetogenic bacteria ferment those products into alcohols and organic acids—including acetic, lactic, and formic acids. The third and final wave of bacteria, the methanogens, converts acetic acid and methanol into underground plumes of methane, carbon dioxide, and water. If the gases escape collection hoses and rise through the layers of garbage, as they do in both old-style dumps and new, they feed potential fires and nibble away at the ozone.

Biodegradation works with microbes, but degradation—minus the
bio
—involves the breakdown of materials from chemical interactions. Think of oilcans rusting in the rain, or shampoo bottles exposed to sunlight becoming brittle with age and breaking into smaller parts. How long any decomposition process takes is an open question. Food and yard waste go faster: some items, like plastic and glass, never seem to go at all, especially in the absence of sunlight, wind, and water. The literature on landfill degradation is substantial, and it emphasizes the uncertainty of knowing when a closed dump will become stable. When the Austrian Environmental Protection Agency studied the issue, it apologized for considering a mere ten-thousand-year time frame, when a hundred thousand years is more likely.

The problem boils down to this: all burials are not alike. Temperature, pH of the fill and cover material, moisture level, and movement of fluids vary around the world, from day to day at any particular landfill, and even between different truckloads of waste disgorged on the same day. Our experience with six-pack rings and hybrid iced-tea cans is young, so we have little information about the degradation of newfangled materials either on their own or commingled with other materials, newfangled or not. Set and setting hold much sway: depending on its burial context, a Granny Smith apple can biodegrade completely in two weeks or last several thousand years.

Archaeologists, who’ve been exhuming buried discards for well over a hundred years, have an acute interest in decomposition rates, which they call Natural Formation Processes, or NFPs. Among their surprising NFP discoveries is that ostrich plumes can remain intact more than three thousand years in a dry climate, and wooden carvings last nearly four hundred, if they’re buried in very wet mud. It’s understood that when moisture moves through a site, as in a bioreactor landfill, the rate of biodegradation increases. But when materials are saturated with water that doesn’t move—in some swamps, in fill behind retaining walls in harbors, and even in outhouses, reports Garbage Project director William Rathje—textiles, leather, paper, and food have been found intact one hundred to one thousand years after burial.

Forensic anthropologists have studied how human bodies decay under very specific conditions: facing south in the sun at latitude 40 in the winter, for example, or facing north in the tropical shade, exposed to rain, sun, and wind. They know that “bog people” in British swamps can be perfectly preserved for 2,000 years, and that nomadic hunters frozen in Tyrolean glaciers can last for 5,300. In fact, we know far more about how our bodies decompose than about how the stuff that makes our lives possible, or pleasurable, decomposes. It’s understandable: we’ve only been studying our waste self-consciously for less than a hundred years.

Why does an understanding of degradation rates matter? Besides our anthropological interest in discard dates (including postmortem intervals), these rates let us predict when landfills will stabilize and, in a more perfect world, make informed decisions about whether we want to bury (or buy) something in the first place.

The majority of landfills excavated by the Garbage Project showed little evidence of biodegradation below the surface. The big exception, of course, was Fresh Kills. Why? Because it is very old, it isn’t lined, it sits in a swamp through which channels and streams flow, and tides flush it twice a day. Even above the water level, garbage absorbs moisture like a sponge. In G. Fred Lee’s microbe-chomping world of wet-tomb bioreacting landfills, Fresh Kills would be a stellar example, except for the fact that it doesn’t have a floor. It is in no way a closed system.

Diggins continued narrating our tour. As the garbage at Fresh Kills shrank, he said, it generated methane, about twelve million cubic feet of it a day. Starting in 1996, the EPA required large landfills to install rudimentary gas collection systems, mostly to halt the frequent fires and explosions inspired by accumulating methane. For years, underground fires had burned out of control in the dumps of the New Jersey Meadowlands. At a 1986 concert at the Shoreline Amphitheater, built atop an old landfill just south of San Francisco, a Steve Winwood fan lit a cigarette and ignited a five-foot column of hair-singeing flame. Even when collection systems are installed, they don’t always do the job. At one landfill refashioned into a municipal park in the Southeast, leaking methane migrated into a cavity beneath a concrete slab. When a soccer ball landed in this hole during a nighttime practice, the woman retrieving it flicked a lighter to get a better view inside.
Kaboom!
She survived the flash, which blew her (and presumably the ball) out of the hole, but her throat and lungs were badly burned. Of the states surveyed for
BioCycle
’s “State of Garbage in America” report in 2000, twenty-nine had at least one landfill recovering gas for energy, versus collection and flaring; fourteen had none; and seven offered no information.

Over the past couple years, Diggins said as he pulled over to let a dump truck pass, engineers at Fresh Kills had installed perforated pipes in the garbage mounds that sucked landfill gas into a boxy-looking plant near the West Shore Expressway. The gas was scrubbed of carbon dioxide, and the remaining methane supplied enough power to light fourteen thousand homes. At least that’s what happened to half the collected gas: the other half, which was nonmethane organic compounds, was treated and then released. I asked Diggins what those distant flaring stations, with their fifty-foot-high stacks, were for. “We’ve got six flares,” he answered. “They were used before all the gas collection lines were installed, and now they’re used when the plant is shut down for maintenance.”

Raw landfill gas contains numerous carcinogenic air pollutants, but burning it in a flare, an engine, or a turbine dramatically reduces its overall toxicity. Before the methane collection pipes were in place, Fresh Kills emitted more than fifteen billion cubic feet of greenhouse and carcinogenic gases a year—almost 2 percent of all the world’s methane, according to the EPA. Nationwide, landfills are the largest anthropogenic source of methane emissions, accounting for approximately 32 percent of total methane emissions in 2002. Even the best-designed gas collection systems, with wells spaced at about one per acre, at most suck up just 75 percent of emissions, according to G. Fred Lee; that number gradually declines as the equipment deteriorates.

Landfills that collect methane for energy, as well as incinerators that derive energy from waste, receive subsidies in the form of tax credits from the state and federal governments. The subsidies, usually associated with alternative fuels and renewable power, give landfill and incinerator operators a financial incentive to process more waste, and they also make landfilling and burning appear cheaper than recycling and composting, neither of which benefit from tax breaks. Opponents of these subsidies like to remind the public that although landfill gas is an alternative to fossil fuel, landfills themselves are not sustainable, and therefore neither is landfill gas. Their concerns are treated by the waste-hauling industry like so much hot air.

As Diggins drove he muttered a punch list—a drainage swale needed grading, a berm had to be raised. His tour was the engineer’s equivalent of a rancher riding his fence lines. At one point I asked about a particularly strong garbage smell. “That’s a leachate seep,” Diggins said. “There’s pressure on the garbage from road material, the stuff we lay down before the final cover. It leaks laterally until enough of it collects, and then gravity pulls it down into the collection system.”

Months earlier I’d visited Phil Gleason in his conference room at DSNY’s Beaver Street headquarters, and the director of landfill engineering had explained some leachate basics to me. Gleason was portly, with round cheeks, an orange-blond mustache, and a silvery blond comb-over. He had a habit of acting exasperated, of cocking his head and rolling his eyes. Still, it was said that Gleason knew everything there was to know about Fresh Kills, so I had gladly braved his withering glances. For three hours he answered my questions, drew diagrams, and fetched maps to illustrate his points.

“This is a leachate mound,” he’d said, drawing a mild bell curve on a sheet of lined paper. “This is what’s underneath the garbage. We build a leachate wall around the entire section that goes down seventy feet, to the substrata. Twenty-five feet in from this wall is a perforated pipe. Since the water pressure outside is higher than inside, the only place the leachate can go is in.” He said the floor of the landfill was bentonite soil, which was “basically impermeable.”

I asked Gleason how William Rathje, in
Rubbish!,
came up with his figure of a million gallons of leachate daily escaping the landfill’s collection system and swirling into the waters that flow along Staten Island’s shore. Instantly, Gleason turned apoplectic. “What he did is . . . he made it up! It’s not a statistic. Rathje studies trash in Arizona!” Gleason turned his head and looked at me from the corner of his eye. He said, remedially, “Fresh Kills is flushed with hundreds of billions of gallons of water a day. The groundwater here is not used for drinking. The landfill is underlain by clays—it’s a composite aquitard!”

Chastened, I turned toward a map and traced with my finger the shoreline I’d paddled so long ago. “That’s Carl Alderson’s wetlands restoration, isn’t it?” I asked. Gleason barked at me, “
His
restoration?
His?
It’s ours!”

“Right,” I said, and we returned to our cutaway views of methane collection pipes. A couple hours later, I packed up the materials Gleason had laid on me, thanked him for his time, and said, in spontaneous appreciation, that his job seemed pretty interesting. He said, “What I do is boring. All I do is yell at people.”

Diggins parked on an elevated roadway so Robin Nagle and I could gaze down upon Plant One, an unloading area in Fresh Kills Creek where a couple dozen empty blue barges were parked cheek by jowl. They looked, from up here, small and manageable. Up close, though, I knew they were cavernous: fifteen feet deep, one hundred and fifty feet long, thirty feet wide, and capable of transporting 1.4 million pounds (the equivalent of four and a half blue whales) apiece. “How many barges are there?” I asked Diggins. “Eighty-two,” he said as fondly as if I’d asked how many children he had.

To the west of Plant One, at the intersection of Fresh Kills Creek and the Arthur Kill, was the verdant sweep of the lyrically named Isle of Meadows, a high marsh that had once been farmed for salt hay. After dredge spoils were dumped on the island in the 1940s and ’50s, the island’s 101 acres of spartina grass and reeds began to give way, along its western flank, to ailanthus, gray birch, poplar, and black cherry, whose seeds could take advantage of this new layer of soil. This upland forest until the past few years provided roosting habitat for six hundred pairs of ibis and heron, plus snowy egrets, black-crowned night herons, and cattle egrets. The insectivorous birds had feasted on flies churned up by the dump’s bulldozers. The wading birds had fed on crustaceans that lived in the toxic waters.

With the nesting population growing, Parks Department ecologist Marc Matsil had described the birds as existing “beyond Dante’s ninth ring.” But then, toward the end of 2001, their population suddenly dropped. Researchers had found cadmium and other persistent pollutants in heron and egret chicks; perhaps it was a simple case of poisoning. Another theory suggested that the birds’ historical predators—boat-tailed grackles, red-tailed hawks, and great horned and barn owls—which had sated their appetites on rodents at the landfill until Fresh Kills closed, had now returned to their more traditional prey. The bounty didn’t last, and a year after the heron, egret, and ibis populations crashed, those of their predators did, too. It is a scenario that ornithologists are still pondering. Whatever the explanation, the birds were gone.

Nagle and I stood side by side, looking down at Main Creek. I envied her for having visited Fresh Kills while it was going full bore. Since the dump no longer received garbage, I had to mentally walk through the unloading process. It started, Diggins said, when tugs pushed the barges—up to four at a time—in from the Arthur Kill on the rising tide, and a containment boom was closed on the staging area. Out in the Arthur Kill, up to twenty barges could be waiting on deck. Onshore, hydraulic cranes with enormous grapples unloaded, or “dug,” one barge at a time, transferring the contents to a concrete pad. The grapples held the equivalent of one fully loaded collection truck, and it took two hours to dig one barge.

I’d seen film clips of what happened next. A front-end loader scooped the mounded trash into a Payhauler, a cartoonishly large dump truck that held about eighty yards of solid waste. The Payhauler trundled up to the active bank. It was as busy as a kindergarten sandbox up there, with dump trucks dumping, dozers pushing loads into two-foot layers, and fourteen-foot-tall, 77,000-pound compactors running over the mess again and again and again. The garbage was buried in fifteen-to-twenty-foot layers called lifts. Fresh Kills had always topped lifts with six inches of soil. At other landfills, lifts received a thinner layer of “alternative daily cover,” which could be shredded tires, shredded paper mixed with water, pulverized glass, or foam.

“The slope is three to one,” Diggins said, drawing a trapezoid on a piece of paper. “So the height of the bank is twenty feet”—he made a vertical arrow between the plateau and the base—“and the slope measures sixty feet from its bottom edge to the top.” He drew another arrow, slanted between these two lines.