• The shack

There it squats in the parking lot at the corner of Burlington’s Main Street and South Winooski Avenue: a teal-blue shed topped with curious devices, some resembling the Wizard of Oz munchkins in hats. No signs explain its provenance or purpose. I circled it a few times, looking for explanations by poking around with camera and notebook in ways that would have gotten me arrested by the Department of Homeland Security in more paranoid cities.

Then I tried the direct approach. The place has a door and a window, so one day, spotting the back of a head inside, I parked my bike and knocked. Twice. No answer. I considered tapping on the window but refrained out of shyness. The sight of my grinning face in its balaclava and black bicycle helmet has caused brave people to recoil.

Following a tip from the Department of Public Works, I called the Vermont Department of Environmental Conservation at its Waitsfield office. Amy Shedrick, a lab technician there, gave me the lowdown on the shed. It’s an air-quality monitoring station that the DEC calls its Burlington Trailer (another station stands on the roof of the John J. Zampieri State Office Building on Pearl Street), and it’s been there since 2003. Vermont has several other such stations, each quietly tasting the air, minute by minute, day after day, for such things as carbon monoxide, particulate pollution and volatile organic compounds. If a forest fire or a distant volcano eruption or just a sudden jump in pollution occurred, the instruments on this shed would be our eyes and ears in the air. Shedrick and her colleagues watch as the information flows in.

“If you go to our website, you’ll be able to see our real-time data,” said Shedrick. “We have local air-quality forecasts and then the air-quality index, which shows if there are elevations in particulates and ozone.”

The munchkin-like figures, labeled “Wedding & Associates, Inc.,” turn out to be instruments that gather particulates by catching them on filters. But, Shedrick explained, the DEC hasn’t used them since its lab in Waterbury, which analyzed the Wedding filters, was flooded last year. Newer instruments at the Zampieri station are currently measuring particulates, and the old ones will probably be removed this summer, creating a subtle alteration to the Burlington skyline.

From internet evidence, Wedding & Associates, Inc. appears to be inactive, destining the munchkins to go the way of so many elegant but elderly scientific instruments.

Should Burlington residents check the online monitoring data before venturing to breathe the air outside? Shedrick said the DEC seldom sees jumps in pollution — “not in Burlington ... If there’s a tanker there that’s filling up the gas station [across the street], then we usually see a spike. It’s usually really early in the morning.” The substances spiking are benzene, toluene, ethylbenzene and xylene, a witch’s brew of volatile organic compounds that rise into the air from petroleum products and can enter soil and water supplies.

Not to be self-righteous — OK, maybe I am; we cyclists can be insufferable. But it’s worth pointing out that most of what the DEC measures comes from internal combustion engines. Vermonters have been driving more with each decade: from about 1 billion vehicle miles per year in 1950 to more than six times that at the millenium. And, as the Vermont Agency of Natural Resources notes on its website, “For every 10 gallons of gasoline you put in the tank, 2 gallons [do the] work, and 8 gallons go out as heat and exhaust.”

The Superblock station is one of the places where such accounts are kept. From the increased pollution readings, said Shedrick, the DEC can tell when a car is idling beside the trailer. (Also worth bearing in mind: the 5.3 billion pounds of carbon dioxide that Vermont cars emit each year, a substance not measured by these sensors.)

I asked Shedrick about the person in the station’s window and why she hadn’t answered the door. “There’s probably a lot of weirdos that knock,” I suggested helpfully.

“Well, that and you can’t hear, actually,” said Shedrick, who said the head belonged to one of her coworkers. “All the motors and pumps are going. It’s very loud in there — that’s probably why she didn’t answer.”

You’d never know it from outside. The station doesn’t release much noise, due to its construction from “vacuum epoxy laminated shelter panels, using aluminum or fiberglass face skins separated by structural foam,” according to Ekto Manufacturing Corp., the shed’s maker. The company has an arid ’90s-era website that also explains the design’s military provenance. “[T]he supplied skids and lift/tie down rings facilitate handling by forklift, crane and rotary or winged aircrafts.” Cool.

The good news is that Burlington’s levels of carbon monoxide, nitrogen dioxide and particulates have long been below national standards, thanks in part to catalytic converters and other emissions controls. But the readings aren’t at zero, otherwise Shedrick and her colleagues wouldn’t have jobs. From lung-penetrating particles to any number of grimly, hyphenated substances such as ethyl tert-butyl ether, we all breathe in these things. Including self-righteous cyclists.

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