If you've ever gazed out the window while jetting cross country, you know that much of America remains a vast wilderness with plenty of nooks and crannies to accommodate the $50 billion annual business of burying the detritus of modern life. Like flushing the toilet and walking away, the waste Americans create, for the most part, quickly goes out of sight, out of mind.
That is, unless you happen to live near one of America's 10 biggest active landfills.
Like Rumpke Sanitary Landfill in eastern Ohio, the sixth-largest in the U.S. based on annual tonnage received, as reported by Waste & Recycling News. Known almost affectionately as "Mount Rumpke," the pile suffered a massive trash slide in 1996 caused by a lightning strike. It took months for Rumpke Industries to cover up the 15 acres of exposed trash — by piling new trash on top of it.
Then there's Orchard Hills, 50 miles west of Chicago, which for the past couple years has been plaguing nearby residents with a strong sulfuric rotten eggs smell. Orchard Hills ranks ninth on our list, with 2.08 million tons of trash received in 2008, the latest year for which data was available. Its operator, Veolia Environmental Services, tried piling more dirt on top of daily trash deliveries and stopped pouring leachate (the icky liquid that drains out of the bottom of a landfill) back on top of the pile. And it's stopped accepting loads that include drywall, which contains sulfur compounds that contribute to the odor.
But honestly, these sites are the outliers. The surprising truth is that today's biggest landfills are not stinky, accident-prone, toxic dumps. Sixty-ton bulldozers with studded steel wheels compact freshly dumped trash in small 1-acre "cells" that are covered over daily with a layer of dirt. Vermin like rats aren't much of an issue: At the giant Puente Hills landfill in the City of Industry, Calif., engineers fastened radio collars on four rats and set them loose. Three of them didn't last an hour, likely crushed or buried. The fourth was a goner in less than a day.
Puente Hills, which absorbs a third of Los Angeles County's garbage, is the second-largest active landfill in the country, with 3.15 million tons received in 2008. Compacted trash is 500 feet deep in some spots.
Which community can boast to have the No. 1 dump? That honor goes to Las Vegas: The Apex Regional Landfill south of Sin City currently receives on the order of 9,000 tons a day. Back in the boom year of 2007, it was getting more like 15,000 tons a day. At 2,200 acres, it has enough room to keep pulling in waste at this pace for 200 years.
Apart from being the two largest active landfills, Puente Hills and Apex also exemplify the new way to think about landfills: as highly engineered machines for turning waste into electricity.
Think of a landfill as a giant digester. Like in a cow's stomach, anaerobic bacteria feeding on waste in a landfill create a lot of gas. This gas, roughly half methane, half carbon dioxide, percolates up through the landfill. In the past the gas would pass into the atmosphere. But that's bad, because methane is a greenhouse gas 22 times worse than carbon dioxide. Nationwide, landfills are responsible for 22% of human-related methane emissions, second only to the backsides of livestock. Luckily it's easier to capture gas from landfills than from cows.
After processing, landfill gas is identical to the natural gas recovered from reservoirs deep underground. The Environmental Protection Agency says that of America's 2,300 landfills, 520 capture gas and burn it to produce electricity — enough to power 688,000 homes. Landfills provide for roughly 1% of U.S. natural gas demand.
Perhaps the biggest landfill gas capture is at L.A. County's Puente Hills, which generates 50 megawatts, enough to power roughly 50,000 homes. Some of Puente Hills' gas is also compressed and used to fuel a fleet of trash trucks. At Atlantic Waste Disposal near Waverly, Va., a 20-mile pipeline runs from the landfill to Honeywell's Hopewell plant, providing 20% of its needs (enough to power 7,000 homes). At Las Vegas' Apex Regional Landfill, a company called Energenic is building a $20 million plant that will turn Sin City's refuse into 11 MW of electricity (about enough to power two casinos).
Houston-based Waste Management is the king of the hill when it comes to managing the nation's biggest landfills. It operates five of the top 10 and owns three of those outright. As a result there's no company that burns more landfill gas than WM: 100 plants generating 500 megawatts, enough for 400,000 homes.
Waste Management's showcase landfill is Altamont Landfill in Alameda County, Calif. Just out of the ranks of the top 10, Altamont's network of pipes crisscrossing the inside of the landfill capture 93% of its gas. This is turned into 10,000 gallons a day of liquefied natural gas, an ultra-low-carbon fuel for 300 specially outfitted trash trucks. It also burns enough gas to make electricity for 8,000 homes.
For good measure, half of Altamont's 2,100 acres is a certified wildlife habitat that's home to the endangered San Joaquin kit fox, the western burrowing owl and the threatened California red-legged frog and tiger salamander. The site also boasts a wind farm. No wonder it was named the EPA's 2009 landfill methane project of the year.
Waste Management is also working on the next generation of landfill tricks. In partnership with oil refiner Valero and trash-to-fuel upstart Terrabon, it's working on techniques to turn plant matter (like yard clippings) and food waste into gasoline.
Now if only the economy would cooperate. Since 2007 Waste Management's revenues from landfill operation have fallen by nearly 20% to $2.5 billion a year. And at the Apex landfill outside of Las Vegas (not one of WM's sites) trash volumes fell by a third last year.
Does less trash mean less gas? Not in the short term. Waste Management says it can keep up the pace of gas extraction at Altamont for 25 years even if it receives not even one more banana peel.
© 2012 Forbes.com