It doesn’t stink.
That’s the first thing that strikes visitors to Dallas’ 996-acre McCommas Bluff Landfill, a former gravel pit lying just south of the Trinity River near the intersection of I-45 and I-20. It would seem that a place that takes in nearly 5,000 tons of garbage a day — almost 2 million tons a year — should emit an odor at least as sour and putrid as a commercial dumpster.
But somehow, it doesn’t.
“We don’t want you to know there’s a landfill here,” says Ron Smith, the city’s assistant director of sanitation services.
At the end of each and every day, his crew spreads a six-inch layer of clean dirt atop the mounds of trash brought in. The dirt helps mask the stench, keeping the stray dogs and rats at bay, and also makes the landfill look more like a construction site than a giant pile of garbage.
Today Smith is giving a tour of McCommas Bluff, a regular part of his job and a task he clearly relishes. From the look of pride on his face, you’d think he was showing off one of the Smithsonian museums. There’s a reason folks around the sanitation services department call it “Ron’s landfill” — Smith can ramble off all the ins, outs and little-known facts about Dallas’ dump site as he navigates his SUV around the perimeter.
And as he does, you start to get the idea that all the trash here is really just “a side note,” Smith says.
“This road isn’t made of gravel — it’s ground-up, recycled concrete.
“See that pecan grove to the left? In the fall, people can come here and gather the pecans that drop.
“That’s a compactor. It rolls over the garbage five times and flattens it so that it takes up the least room possible. At a landfill, space is money.”
Trash is Smith’s business. And in Dallas, it’s big business. Most of us don’t give another thought to our trash after garbage trucks collect it from its front driveways or alley each week. And even if we do think about it, we likely assume it’s taken to a remote location, then left to sit and rot for the next few decades or centuries.
“From the person on the street’s perspective, garbage collection looks exactly like it did 50 years ago,” says sanitation services director Mary Nix. “But technology has changed dramatically.”
For one, we’re recycling more than we ever have. This means less garbage being dumped into the landfill, something that will add years to the landfill’s life. And, Nix says, our recycling numbers are growing as more and more Dallasites warm to the idea. Plus, all those milk cartons and soda cans create revenue for the city — just not enough to pay for the city’s recycling program.
The real money-maker is all of that precious space at the landfill, along with the fact that Dallas lets anyone use it who is willing to pay up. McCommas Bluff is so big — the biggest landfill in the state and the 15th largest in the nation — that the city has room to spare, at least for a few more decades.
And perhaps even longer, if landfill technology continues to improve. Dallas recently began implementing the latest landfill science, called “bioreactor technology”, which quickly breaks down trash into methane gas that is then sold into natural gas pipelines. Not only does this process create another source of city revenue; it also chips away at the landfill’s giant piles of garbage, leaving room for even more trash.
And with more innovation, Smith says, McCommas Bluff could feasibly last forever.
“The landfill is still finite,” he says, “but I am convinced that something will come along that will allow us to keep this thing going indefinitely. Some technology will probably evolve over the next few decades that will probably make it infinite. I don’t know what it is — it has to be cost effective, so it has to cost less than trash. But when somebody works that out, we’ll be able to mothball the landfill.”
For now, Dallas residents live with the reality that garbage heads to one of two places — a recycling plant that cleans and packages anything reusable to ship it overseas, or a landfill within our city limits.
The numbers might astound you, in terms of how much we throw away on a daily and yearly basis. Read on to find out more about our wastefulness, steps we can take to curb the amount of garbage funneling into our landfill, and how the city has taken our efforts to recycle as well as our apathy about trash and turned a landfill into a gold mine.
The cutting edge: ‘Bioreactor technology’
Anyone who takes the time to hear Ron Smith talk about this technological process might start to see the city dump as an opportunity to harvest renewable energy, rather than a nasty necessity. Trash, to him, means energy and revenue.
“When I look around this landfill, I don’t even see trash,” Smith says, “I just see food for the microbes and feedstock for a renewable source.”
The technology quickly converts the landfill’s garbage into methane gas, which is sold to Atmos Energy and pumped into pipelines. That’s especially noteworthy when you consider our landfill was the first in the state to use the technology, and only one of about 20 in the nation — the largest, in fact — using it today.
Think of it as “composting on a larger basis,” says sanitation services director Mary Nix. In that sense, the idea is “easily 100 years old or older.” But in terms of applying bioreactor technology to landfills, she says, that began in the early ’80s.
Converting garbage into methane gas isn’t a new idea — trash will eventually break down and create methane, and some landfills burn it off while others trap and use it. Smith has opted to take this one step further, implementing technology to help the Dallas landfill’s trash create methane even faster than it would if left alone.
Because the technology creates methane more quickly, it translates into more revenue for the city. The landfill produces 5.5 million cubic feet of gas daily. Nix says the city expects to net a little more than $800,000 in methane sales during 2009. (The city did not make any money on methane last year because until 2008, any profits went to the methane processing plant’s investor — T. Boone Pickens’ company, Dallas Clean Energy — which assumed all risk, costs and profits for constructing and operating the plan for the first 15 years.)
The biotechnology has been underway for about a year at McCommas Bluff, but it could be another year before we begin to see measurable results, Smith says. The landfill has 30-acre chunks of land called cells, and right now, bioreactor technology is being used only in one cell at a time. The hope is that it be used for every cell in the future.
Here’s how it works, in a nutshell.
Start with 996 acres of land dedicated to dealing with the city’s waste (accepting about 2 million tons of trash per year, the McCommas Bluff is Texas’ biggest dump).
On the east end of the dump stands a tower that stores sludgy recycled trash water containing bacteria, fungi, and other microorganisms or microbes.
The yucky mix flows from the storage tower into horizontal perforated pipes that line the landfill.
The liquid is then injected into the trash, where it acts as food for hungry microbes, causing the trash to decompose much faster than it would normally.
Accelerated decomposition means faster generation of valuable gaseous byproducts — methane and carbon dioxide.
Another set of vertical pipes acts like wells, sucking up the gas and transferring it to a processing facility on the west end of the land.
Machinery at the processing site sterilizes and separates the gases, preparing them for sale to Atmos Energy and other customers.
The economy of space
Garbage service is built-in for the city’s single-family homes (it accounts for the biggest chunk of the $20.98 charge on our monthly sewer bill), but multi-family complexes or businesses have to pay by the ton to dump trash at the landfill. Because McCommas Bluff is so large, Dallas accepts trash from other counties, commercial outfits and anyone else willing to pay its $21-per-ton fee. That’s the most substantial way the city generates revenue on McCommas Bluff, a total of $25 million in 2008.
The city expected to net $28 million in 2009, but a good portion of its customer base is the construction industry, and because the economy has weakened, Nix says, construction tapered off so the city expects to net $23 million.
The landfill opened in 1981 and is projected to be used until 2031, when it originally was estimated to fill up. But bioreactor technology could mean it will last much longer than that — another 22 years, Smith says.
Because the technology breaks down garbage more quickly, it means the amount of garbage in each cell will decrease more quickly, translating into more space in the landfill — and Smith says, space equals money.
The cost to run the landfill was $18.5 million in 2008, so with dumping fees plus residential garbage fees (roughly $4 million annually) the city expects to earn roughly $9 million in 2009.
And if, as Smith predicts, new technology evolves that changes landfills from finite to infinite space, McCommas Bluff could continue operating as a city cash cow for decades and even centuries to come.
Reduce, reuse…you know the rest
Recycling has come a long way in Dallas, Nix says. “We were pretty behind for a long time. We did not follow the green track in late ’80s and early ’90s,” she says.
In 2005, only about one in four Dallas households recycled. Today, Nix says almost half of Dallas homeowners recycle: “Our count of recyclers, as provided by route drivers and further estimated based on big blue cart deliveries, is 46 percent.”
The city’s goal for the “Too Good To Throw Away” program, which educates homeowners on recycling and provides the blue bins for single-family residences, was 50 percent of eligible households by 2011.
“We ought to get there a bit earlier than estimated,” Nix says. “We’re certainly seeing big strides in the amount of recycling materials we’re collecting.”
Effective recycling programs mean more landfill space; our current recycling rate means we save more than a month of landfill space every year.
“When we bury something, we hope it will degrade,” Smith says. “Everything we want to go into the landfill is not this type of stuff [gesturing toward a plastic water bottle from which he’s drinking]. We want it to decompose.”
The city doesn’t sift through garbage to mine recyclables, so any non-biodegradable items tossed in the trash remain in the landfill taking up space.
“We would love for it to be out,” Smith says. “It’s not a perfect world — but it is getting better.”
Now you know what happens to all those dirty diapers and half-eaten sandwiches (a.k.a. the icky trash) and bulk trash. But what about the so-called clean trash — the stuff that goes in the blue recycling bins?
Here’s how it works:
The city’s sanitation services department collects recyclables from the single-family and community recycling bins.
Those recyclables (30,000 tons in 2008) are shipped to the city’s recycling processor — Greenstar at Northwest Highway and Shiloh in Garland — which separates the materials into marketable packages, and sells the materials to buyers (except for glass and non-recyclable contaminants). The city’s share of the 2008 revenue that GreenStar earned from those sales was $2.2 million.
Any recycled glass is delivered to the McCommas Bluff landfill — not for disposal but for beneficial re-use: The landfill is able to crush the glass and use it as a gravel substitute for below-ground drainage features. (“That reduces the amount of clean gravel we’d otherwise need to purchase for those drainage features,” Nix says.)
Any contaminants, roughly 10 percent of what Dallasites place in recycle bins (Nix says this is a low number), is sent to the McCommas Bluff landfill for disposal.
Recyclables: A city moneymaker (sort-of)
Yes, the city does make money on the old magazines, used water bottles and empty aluminum cans that Dallas residents toss into blue bins. Our recycling efforts aren’t enough, however, to cover the cost of what the city spends to pick up recyclables — in 2008, the funds generated by recyclables recouped roughly 40 percent of the cost.
On top of that, the city’s department of sanitation services never knows how much money recyclables will generate because the cash paid for this kind of trash — formally known as the “recycling commodity market” — fluctuates constantly, and oscillates for some items more than others. For example, department director Mary Nix says, “old newspaper has seen a less drastic variance than old metal cans (steel and metal mixes — not aluminum).”
With the economy in a recession over the past year, the market for recyclables “dropped quite starkly,” Nix says, but began leveling off more recently. The city hopes the market improves, but Nix is quick to emphasize that, ultimately, Dallas’ recycling efforts are not about money.
“The city has committed to a recycling program based largely on its positive impact on our environment,” Nix says. “The revenue-share is a way to help offset the cost of the service, but is not its primary driver. So, we’ll continue to promote the recycling.”
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