Posts Tagged ‘methane

21
Apr
09

studying stink

I recently ran into some of the scientific literature about stink studies. These are conducted in the Netherlands near garbage dumps, incinerators, and other business enterprises likely to cause environmental nuisances, especially of the olfactory kind.

I don’t know if this is the case in the U.S., but stench is considered pollution in Europe. There’s a hedonic value scale that says that “very slightly unpleasant” (H=-1) is acceptable, but “slightly unpleasant” hedonic values (H=-2)  in residential areas amount to actionable environmental degradation. That is to say, if people live in a “slightly unpleasant” stink plume, something must be done to contain the nuisance.

Obviously, no enterprise is going to spend good money remediating its general stinkiness unless there are reliable, quantitative measurements that show incontrovertibly that H=-2 has been achieved. Measurements are made in stink units and in sniff units. If I understand the literature, the organization undertaking the stink study sends something much like a focus group into the field, at the same time that project leads analyze and measure ambient air and track activities at the (potentially) offending location. The members of the focus group, known as the sniff team, sniff the air. I’m not sure if they use expert sniffers or if they are recruited on Craigslist as representatives of the general population, as is standard operating procedure for focus groups these days.

Sniffing

Sniffing

Whatever their credentials, I can’t resist picturing them, standing in the weeds like partridge hounds, chin raised, nostrils flared, brow furrowed. They inhale slowly and deeply, experiencing the air, savoring its aroma as if it were wine being judged in a contest, and then spitting it out. Bluuch. Very slightly unpleasant, full-bodied and complex, methane-forward, with suggestions of trichloroethylene, halogenated hydrocarbons, considerable complexity in the biphenyls, and a sexy note of barnyard. Units are noted on the PDA.

I imagine the sniffers are posted all around the area, and they probably raise their olfactory equipment into the air at prescribed intervals for repeated readings. Their various savorings of the air are eventually compiled. Obscure calculations are performed to transmogrify qualitative experiences into quantitative results and to correlate awarded sniff and stink units with business activities and weather conditions. The idea is to produce not just readings of the moment, but to pinpoint the source of the bluuch and to extrapolate how often bluuch might obtain during the year.If the units exceed legal limits, remedial actions must be undertaken, and then the focus group/sniff team goes to work again, to make sure hedonic values are up into approved regions. It may also occur that plans to build new housing in the plume will be scotched based on findings.

Like many things in life, the law is a two-edged sword. I quickly ran into some studies commissioned by the stinkers to prove that they produced too much stink to allow housing to be built in their vicinity. Clearly, they didn’t feel like cleaning up.

A person who was at one time employed by the province of Zuid-Holland appears to have been in the course of compiling a stink atlas of the Netherlands, gathering together an array of stink findings for various locations and branches of industry. For the most part, incinerators are found to remain within permissible hedonic limits. Landfills are a different matter. The active face is, predictably, the source of most of the offending odors, but fugitive methane from older sections is also fingered as problematic. It doesn’t just cause global warming, then; it induces anhedonic states in the bystanders.

Now I don’t believe that the  Zuid-Holland stink expert was at all concerned with agricultural stink, which I can testify, as a focus group of one, is considerably more than slightly unpleasant in the general environs where I currently reside. (Agricultural stink might be too gargantuan a project to map, but I suspect that the real reason is that farmers are too well organized to permit any government to put stink limits on their activities.) A short bikeride from my cottage to the nearby village for groceries is an obstacle course through multiple chicken dung, sheep doo, and hog manure plumes. It smells rural, Dutch people say.

Local farmers are apparently resolarizing agriculture, refusing petroleum-derived fertilizers in favor of the traditional thing. Good for them, of course. But the hedonic values are way south of the worst landfill I’ve ever smelled.

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04
Mar
09

magic mountain

Where the New Jersey Meadowlands inspire a sense of doom, the Ivy landfill near Charlottesville, Virginia, is its very opposite, with its 350 acres of wholesomeness, optimism, and can-do spirit, seasoned with a herd of deer and a mountain lion stalking their steps in fauning season. Even if 87 of those acres are covered in garbage buboes.

Ivy Landfill, Covered with Snow

Ivy Landfill, Covered with Snow

It doesn’t hurt that it’s so pretty out here, garbage and all. Overwhelmed by mountains, a vast temperate rain forest quietly biding its time, virgin snow and deep-blue sky, a measly little PVC pipe sticking up out of the earth here and there seems a minor thing. Even if it’s going to take 30 to 50 years for that pipe to become unnecessary—at the current best guess of sanitary engineers—it just doesn’t look like the end of the world. Outlook, it seems, has a good deal to do with the view.

Ivy’s operations manager, Mark Brownlee, a mild man in his late fifties or early sixties with a very red nose, kind eyes, and a musical southern twang, took me around. After an awkward start and the usual suspicious/incredulous questions (“What program is this for? Who are you with?”), he became pretty straightforward.

Ivy got its start in life in the 70s, as Charlottesville’s city dump, before the introduction of current landfill regulations. Later the landfill also accepted waste from other communities in Albemarle county. When I lived in Charlottesville, in the spring of 1990, I did my best to help it grow–albeit in blissfull ignorance of what happened to my stuff after I gave it up for adoption, once a week. It seems I’m partially responsible for the bubo to the left of the road in the picture above, since Mark told me the bubo to the right contains only construction and demolition debris. I remember arguing with my husband over who should take out the trash, but I have absolutely no recollection of thinking about my garbage, ever once, beyond its short trip to the curb. Of course, I don’t. I had better things to do, back then, than worry about what happens to my garbage.

Garbage Transfer, Front Row Seating Provided

Garbage Transfer, Front Row Seating Provided

In 2001, the landfill closed. A layer of clay icing has been added on top. Pipes stick up everywhere like birthday candles. Mark allows as how the Rivanna Waste Authority, which he embodies, has to be vigilant and inventive, to make sure the landfill doesn’t come to haunt its upscale neighbors, like Freud’s return of the repressed. So methane is monitored, captured, and flared off.  Leachate is collected and trucked to a treatment plant. Bacteria are injected into the landfill, in the hope that they will neutralize harmful substances. Volatile organic compounds are extracted by the shiny new soil vapor extraction machine, one of the very first to be installed, according to Mark.

Residents can deliver recyclables, including cell phones and paint, newspaper and cardboard, as well as reusable items, among which, remarkably, is a huge contingent of exercise equipment, good intentions gone to waste.

The Edge of the Magic Mountain

The Edge of the Magic Mountain

All the while, the upscale neighbors are kept informed of all developments with an unusual spirit of openness. That’s what impresses me most: this simple willingness to lift the veil. It compares exceedingly well with the more usual response, which is to come running with loud protests and write down my license plate number if I take a picture of the outside area of a landfill.

And in the meantime,  the garbage still arrives, in its never-ending way. It goes from the garbage truck onto the conveyer into another truck, and then off to a Waste Management landfill just outside of Jetersville, Virginia, a mere bump on the map which doesn’t seem to have a whole lot going for it besides space for everybody’s else trash.

14
Dec
08

subtlety and sweetness: bioreactor landfill

Andries Vierlingh, a 16th-century Dutch dike master, specialized in small interventions—subtle alterations in the natural environment that would bend the forces of nature to his purpose. He studied tides and currents to understand how to encourage the waters to deposit silt where he needed a dike, how to set the tides to scour a channel where he was looking for better drainage. “With subtlety and sweetness,” he wrote, “you may do much at low cost.”   He recommended patience, gentleness, and cleverness. His minimalist approach was mostly inspired by necessity. He had dirt, and he had labor in ample supply, as well as spades to bring the two in fruitful alliance. He had primitive, wind-driven pumps but often unobliging weather. Very little wood, except profusions of willow shoots with which to weave mats. No stone, except prohibitively expensive imports. Small wonder that he looked to subtlety.

In the U.S. today, true want of resources is an unaccustomed circumstance. Vierlingh’s spirit of patient minimalism is rarely practiced, I suspect in part because greater glory lies in bigger budgets and more fantastic equipment. So it is something of a surprise to find an experiment in such minimalism at Yolo County Central Landfill, in the middle of the grasslands just west of Sacramento, California.

The experiment in question is an effort to render our trash into a geologic formation, cheaply and expeditiously. That is the description of the project offered by Don Augenstein of the Institute of Environmental Management in Palo Alto. Don is a somewhat other-worldly presence, a fount of information on garbage, renewable energy, and climate change, and one of the movers behind the Yolo County outdoor garbage lab. He invited me along on a tour of the dump on the dreary Wednesday before Thanksgiving, together with a gaggle of junior college students who didn’t look wildly enthusiastic about their field trip.

yolo, trash arriving

yolo, trash arriving

Since this was a regular working day, the landfill was as busy above ground as below.  Trucks drove in large loads and small, coming in thick and fast enough to cause a backup at the gate.  Heavy equipment trundled over the mounds, compacting and molding and pushing around the fresh leavings. Piles of stuff that can be snatched from the abyss were being moved from one place to another. Concrete was being mauled into its constituent parts. A sorry pile of bathroom porcelain, sat pale and forlorn in the middle of this bustle, the still center in a vortex of industrial activity. Flocks of gulls, inevitably, wheeled above the scene, screaming as they always do.

bioreactor cell

bioreactor cell

Much of what is to be seen at Yolo is just conventional landfill and its attendant recycling activities. The proceedings remind me of a landfill in Amersfoort, in the Netherlands. But several “cells”—the lined landfill compartments in which our trash is stored until we can think of a better thing to do with it—have been rigged at Yolo as bioreactors. Leachate is judiciously circulated through these cells, which have been constructed very much like the usual layer cake of trash and daily cover, but with a subtle difference.  The daily cover itself is permeable so as to facilitate the even movement of moisture. The whole thing is topped with a layer of shred tire and then wrapped in plastic, which in turn is held in place by whole tires and wheelhubs and other  paper weights that sanitary engineers typically have ready to hand. The shred tire layer on top is to encourage the desired flow of methane gas through the dump, for more efficient extraction. The plastic wrapper prevents its escape into the atmosphere. The whole sandwich is built and monitored under the watchful eye of Ramin Yazdani, whose business card lists him as senior civil engineer at the Yolo Planning and Public Works Department.

methane to electricity

methane to electricity

The purpose of the bioreactor is to more effectively collar methane, a significant part of which goes on the lam at conventional “dry tomb” landfill despite methane capture systems. Methane doesn’t directly harm humans (as many of the other landfill effluents have the potential to do), but it is a potent greenhouse gas. “Fugitive” landfill emissions contribute significantly to global warming. However, when captured, methane is an effective fuel, and the idea behind the bioreactor is to get the trash to give up all the gas in a short, sharp burst. In this way, the trash becomes less of an environmental menace and at the same time a more economical source of fuel—a double whammy in favor of the planet.

Experiments to do the same thing are being conducted in Spain, France, Belgium and elsewhere, but in vessels specially built for the purpose. These “digesters” are expensive and require significant energy inputs. They can’t handle all the waste in the waste stream, even after recyclables are removed. And they extract far less methane from the “feed stock” than the landfill bioreactor at Yolo—which has an extraction rate of more than 95% over the course of a year.

This excellent result is achieved at low cost, both in terms of funding and energy inputs. The most remarkable “energy in” lies in the dedication and inexhaustible inventiveness of the human motors behind the experiment—Augenstein’s genius with numbers and Yazdani’s wizardry in building things that work almost out of nothing. Vierlingh would be very pleased to find out that throwing more resources at the problem delivers a less effective solution than an attentive eye and subtle adjustments in the way a landfill is put together.

ramin yazdani, monitoring underground activity

ramin yazdani, with monitoring equipment

In the meantime, the garbage at Yolo is monitored as carefully as a patient in the ICU. Continuous measurements of moisture, temperature, and pressure inside the stewing trash heap are taken, while the composition of gases that arise from it is analyzed. Workers collect leachate samples that go off to a different lab for analysis.

Regulators have yet to be persuaded that simple and subtle solutions may be more sound than big-muscle engineering, and so the collection and analysis of data proceeds patiently as does the effort to present results. I hope they succeed, because their solution seems important in a world where landfill still is the most common trash management approach. What’s more, their spirit of inspired minimalism seems to be the right recipe for a hot and nearly exhausted planet.

17
Oct
08

a brief primer on plumes

The United States may have as many as 100,00 landfills, large and small. A significant proportion of them doesn’t have a liner.

A plume visualized by cross-cut

A plume visualized by cross-cut

Contaminants from landfill leach into groundwater in unsavory plumes containing heavy metals, chlorinated compounds, and hospital germs, to mention just a few of the ingredients. Take Fresh Kills landfill on Staten Island, which is built in a tidal swamp. The tides wash into its bed unhampered and wash out leachate, an estimated 3 million liters of it every day (which is almost 800,000 gallons). Under certain conditions, some of the contaminants from landfill may be cleaned up by naturally occurring processes, as a study at the Norman, Oklahoma, landfill has shown. but not nearly all of them. Moreover, it takes time.

In addition to leachate, landfills release methane, which is created when organics decompose when there is no oxygen and which contributes heavily to global warming. In fact, landfill methane is thought to account for about 5% of the total annual increase in “radiative force” that lies behind the greenhouse effect.  In other words, the adverse effects of landfill are both local and global. Back to Fresh Kills for a moment: according to a 1998 estimate, it releases 2,650 tons of methane a day. Perhaps that number is reduced somewhat since dumping stopped (in 2001), but it can’t be by much. After all, the garbage is still there quietly percolating under the skin of dirt that covers it up.

How long it takes for a dump to stop being a source of pollution is not yet known. Under normal conditions, most organic materials will decompose to clays and other natural substances in about 30 years. But in landfills, conditions are not normal. The stuff is packed in so tight that not enough air and water gets to it for the decomposition to proceed apace, in part because these huge piles we build cocoon much of the trash inside them, in part because sanitary engineers try to halt the decomposition process to prevent leaks.

On the whole, then,  there’s not enough air and water to speed along biodegration, too much air and water to prevent contamination and outgassing.

Guadalupe landfill, San Jose, CA

Guadalupe landfill, San Jose, CA

The serious environmental impact of landfilling our waste was not fully recognized until the 1970s, when the EPA began to insist on an engineering standard to contain leachate and methane, at least to some extent. All the same, the EPA recognizes that no liner is equal to the environmental stresses to which it will likely be subjected over its lifetime. Sooner or later, that leachate plume will emerge. And no methane collection system comes close to capturing all the gas generated in our trash heaps.

In the decades after the EPA established regulations, many of the older unlined, unengineered dumps were closed. In some cases, remediation systems were subsequently put in place. Most dumps, however, were simply taken out of operation and covered up. I’m sure it’s a good thing to stop adding to the problem, but closing a landfill to new arrivals doesn’t in any way mean that current occupants are no longer leaving. “Closed” really isn’t quite the word for a landfill at which the garbage trucks have stopped coming. Neither is “inactive.”

A few of the very worst landfills have been cleaned up, such as the infamous Love Canal dump in Niagara Falls. Much depends, it seems, on local activists. In other cases, cleanup is really unimaginable. Think of Fresh Kills again, which contains 67,000,000 cubic meters of compacted trash in four mountains spreading over 12 hectares of land (or 2,366,082,670 cubic feet spread out over 2200 acres). Perhaps we can expect improved containment systems in the future, but cleanup is hardly in the cards for a country that has squandered much of its wealth in the pursuit of ever greater riches.

Why exactly do we have landfills if they are so bad? Why are new landfills still being made?

It’s not that there is no alternative. In Germany and the Netherlands, for example, all non-recyclable, non-hazardous waste is burned. In 40 years of heavy reliance on incineration, there have been no environmental disasters. From what I can understand, incinerators don’t scrub every last pollutant out of the exhaust gases, but their overall environmental impact is considerably less severe than the cumulative effect of landfill when considered over the entire life of the garbage.

From all my reading on the subject, I can distill only two reasons why landfilling is still standard practice in this country, despite severe environmental consequences:

> Space is still cheap, and landfills are relatively simple to build, requiring modest upfront capital investment, even now that more engineering is required.

> The environmental movement has organized very aggressively against incineration. In Fat of the Land, Ben Miller explains that environmental organizations feared that incineration would stand in the way of recycling. They scared people half to death with the notion of toxic ashes left over after combustion, and all over the country they turned out crowds to protest very effectively. Too bad if it was under false pretenses. Incinerator ash doesn’t contain any toxins that aren’t to be found in the dump. Burning doesn’t create toxins, although of course it does get rid of biohazards. Ash is significantly more stable than household garbage.

Northwest Incinerator

Northwest Incinerator

Of course this is not to say that every incinerator necessarily runs as it’s meant to. The Northwest incinerator in Chicago, which has devoured some of my own trash, seems to have been in violation of safety standards much of the time.

If Miller’s supposition is true, it’s a sad chapter in the history of the environmental movement. Here we are, 30 years later, with a handfull of incinerators, 100,000 leaky landfills, and 100,000 plumes, large and small. , a mere handfull of incinerators (a few of them them–I will say this–perpetually in violation of safety standards, such as the Northwest incinerator in Chicago), and no recycling yet in lots of places.

Fortunately, new developments are underfoot. With the rising price of oil, the larger landfills have started turning captured methane into usable fuel. There are experiments with bioreactor landfill, in which the trash is treated to decompose faster and release more methane (for fuel) under more controlled circumstances. A new generation of incinerators is being built, which would burn garbage at higher temperatures, posing even less environmental risk. I’ve heard they can mine old landfills for fuel, which would mean that some of those 100,000 could perhaps finally disappear.

More on Fresh Kills:

love letters and  cabbage leaves

landscape inspirations

More about trash in Chicago:

connecting the dots




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