By Jesse Marx
By Chris Parker
By Jake Rossen
By Jesse Marx
By Michelle LeBow
By Alleen Brown
By Maggie LaMaack
By CP Staff
On the historic occasion of the state's first "unhealthy for all" air quality alert in a quarter-century, the Hennepin Energy Resource Company decided to mark the event by burning some garbage. Last week wasn't anything special for the plant known as HERC. This boxy facility just north of Minneapolis's Warehouse District burns garbage all the time. The company converts our municipal waste into steam energy, which it then sells to Xcel Energy.
Xcel, for its part, responded to the air quality warnings by continuing to operate what very well may be its grubbiest energy facility in the metro, the coal-fired Riverside Plant.
Back in the Warehouse District, not far from the garbage incinerator, Metro Transit buses could be seen idling at the curb, empty, on driver-training routes.
All throughout the city, a plan appeared to be in effect to address the soaring particulate count that would soil the air for four days. The plan? Do nothing.
The group of professionals who seemed most stirred to action was the media. TV and newspapers alike made much of the "perfect storm" scenario; it was actually just a stubborn mass of stagnant air. The Air Quality Index--a federal standard for measuring major pollutants--did indeed top out at contemporary highs: It hit 156 on Monday night in Minneapolis and, not long after, peaked in other cities across the upper Midwest. But particulate pollution--known as PM2.5--wasn't measured until just a few years ago, a point made by Rebecca Helgesen, a spokesperson for the Minnesota Pollution Control Agency. The air, she suggests, isn't necessarily any nastier than it was a decade ago.
And the state has seen similar numbers before. The AQI hit 135 on July 5, 2003, and a grimy week last February saw elevated particulate counts in the skies for four days running.
Though the skyline appeared to be shrouded behind a mildewed shower curtain, there was no reason to panic. Cities like Los Angeles and Houston routinely hit far higher numbers; the AQI scale goes all the way to 500. Public health research connects PM2.5 pollution to mortality in heart patients, and aggravation of emphysema and asthma. But a few days don't make that great a difference.
Despite epidemic levels of childhood asthma, the Minneapolis Public Schools saw no increase in absenteeism related to air quality. And most of the respiratory cases at Hennepin County Medical Center, director of pulmonology Dr. Conrad Iber says, came from the flu. In fact, on the two haziest days last week, Iber admits, he went outside for a run.
"Physiology operates on a continuum," Iber says. "We don't suddenly fall off a cliff based on a single level. Usually we develop a disease based on exposure. And I think there's no question that lower levels of exposure all your life are likely to accumulate into a problem."
It's up to public health and environmental officials, Iber explains, to figure out when these fluky days will lead to fatalities.
Near the endof many of last week's media stories, after the warnings to heart patients and asthmatics to pare back their triathlon training, came the appeal to the public. They were the same recommendations sent to an industry and public partnership called Clean Air Minnesota. Cut back on driving, the MPCA urged. Lay off the small engines, your chainsaws and snow throwers. Keep the hearth unlit for a few nights. They were fine ideas, all.
Yet the public could be forgiven for wondering what--if anything--the MPCA was telling the state's major particle emitters. Would people be surprised to learn that the MPCA's main response to a serious spike in bad air was to send these industries a mass e-mail? How many car trips to the supermarket add up to a garbage-burning plant, anyway?
Jake Smith, senior environmentalist with Hennepin County, says that the HERC emits 175 pounds of emissions each day. Though lead, mercury, dioxins, and particulates come out of the plant, they generally do so at a fraction of their permitted limits.
Still, 175 pounds sounds like a lot of unsavory stuff. (Maybe it's just the word "garbage.") Can Smith think of a time when the HERC has halted operations to limit emissions during an MPCA-declared air alert?
"No, I can't," Smith says, adding that HERC has obligations beyond air quality. "We do have performance guarantees that we have to meet, and we also have a contract with Xcel, so any kind of shutdown could result in penalties."
Smith goes on to say that the billowing plumes of smoke that one sees pouring out of the stacks are mostly hot air. Ninety-nine percent of the smoke, in fact, is water vapor that's 250 to 300 degrees. The particulate load, Smith says, "is minimal compared to the emissions you would see from just the metro buses that are running in the city."
It's an unsporting accusation to level at Metro Transit. When it comes to our sick skies, virtually everyone (who doesn't work for the Taxpayers League) agrees that buses are part of the cure. Limiting routes during an air alert would presumably put more cars on the road. Not a good idea.
And, contrary to appearances, Metro Transit does have an idling policy, issued in October of last year. "In general," explains Bob Gibbons, director of customer services, "it says that if the temperature is above 32 degrees and if your layover time is longer than 3 minutes, then you must turn the engine of the bus off while you wait between routes."