Volume 8, Number 41 - January 1, 2009
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DEQ prepares for ozone season
It’s ironic. The same agency that is charged with mitigating air pollution is the same agency hoping for it.
The Wyoming Department of Environmental Quality (DEQ) is involved with four 2009 studies to investigate Sublette County’s enigmatic winter ozone.
But it is impossible to study ozone, and potentially eliminate it, until it is formed.
A secondary pollutant – meaning it’s not directly emitted from a source – ozone is most commonly found near big cities during the heat of the summer.
It’s formed by 200 complex chemical reactions created by a combination of Nitrogen Oxides (NOx), essentially engine exhaust, and Volatile Organic Compounds (VOC), best described as the barely-visible fumes from petroleum products.
In Sublette County two more precursors are required before the NOx and VOC become ozone. It requires a tight inversion where a thin layer of cold, pollution-containing air is trapped near the ground by warmer air aloft. And it also requires sunlight augmented by an uninterrupted snow cover to “cook” the noxious brew into the world’s only known case of winter ozone pollution.
The county’s energy development virtually ensures the presence of NOx and VOC and inversions are common to the area in the winter.
The wild card is snow cover.
In 2007, with hundreds of thousands of dollars spent on air monitoring equipment and personnel, a sparse snow cover precluded ozone’s formation.
But in 2008, a robust snow year made ideal ozone conditions that led to recorded eight-hour ozone average of 122 parts per billion (ppb) – the federal standard is 75 ppb.
Just like 2008, this year’s ozone season hinges on snow cover.
“Once you see sagebrush, you’re not going to get the conditions we had (in 2008),” DEQ Air Quality Division Monitoring Section Supervisor Cara Keslar said.
Little more than a week ago, Keslar looked at the Boulder Monitoring station’s Web cam with little enthusiasm; the snow cover was too thin.
But after the Christmas Storm, conditions changed dramatically.
Perhaps 2009 will be a good year to study ozone.
DEQ hopes so; it has committed more than $550,000 to the topic.
This year will see some changes to the county’s air monitoring program. A new site has been built on North Jackson Avenue in Pinedale. It will accompany the Daniel, South Pass, Jonah and Boulder sites in the New Year.
The Jonah site was shut down after drill rigs encroached on its location making ambient air monitoring impossible. Keslar said the rigs have moved but the site’s data will carry an asterisk.
“We’re not submitting (the data) to the EPA,” she said. “It will only be running for purposes of ozone monitoring.”
The DEQ hopes to have the station moved to a permanent location near the Jonah by next winter.
The Boulder site – it’s the location that recorded 122 ppb last year – has some changes as well. Now known as a “super site,” the station has added a second trailer of monitoring equipment that includes another ozone monitor to determine “if the VOC are interfering” with the traditional ozone measurement, Keslar said.
In addition, the site has a “semicontinuous VOC monitor” that will speciate VOC.
All of the stations will be getting an additional page on the Web site wyvisnet.com. Responding to suggestions from the public, Keslar said her agency is upgrading the site to include “interim recent data” from preceding weeks and months.
Two ozone-specific studies will target the pollutant from Jan. 15 to March 31.
The first is the Upper Green Winter Ozone Study (UGWOS), in its third year. While UGWOS suffers from an unflattering acronym, the approximately $590,000 study is funded by the Petroleum Association of Wyoming.
It will fully mobilize when all the ozone procurers are in place during “intensive operating periods.”
The DEQ hopes UGWOS will help it “understand the mechanics of ozone formation … to figure out how it is forming so we can understand how to control it,” Keslar said.
This year’s UGWOS study will not be using airplanes; instead it is using weather balloons to take samples at different altitudes.
Another study, this one by the University of Wyoming (UW), will deploy a team in-county as well.
Keslar said the UW team hopes to map areas of ozone formation “basinwide.”
Because the DEQ’s sites are highly sophisticated and very expensive, the agency can afford only a few. The UW study is going to use relatively inexpensive, less sophisticated instruments to cover a larger area around the county.
The study will also use a mobile trailer to study the air from multiple locations.
Keslar said the study is funded with a $164,000 matching grant from DEQ.
It will be sampling “for the first six months of 2009,” according to the project plan.
The fourth ozone-related study this year is Sublette County Human Health Risk Assessment, Air Toxics Inhalation Project.
“The intent of the sampling program is to collect samples sufficient to describe the exposure of the general population of Sublette County to Hazardous Air Pollutants,” the project’s proposal reads.
The DEQ has contributed $100,000 to the study that was originally drafted as a $300,000 study to monitor pollution in the county’s population centers. But after the study’s scope expanded to include monitoring air as it enters the county, the project’s price increased to almost $800,000.
Center of attention
The county’s air is going to be the center of a lot of attention this year.
Hundreds of thousands of dollars and countless hours of work are converging in the four major air studies. The studies do not duplicate each other’s work; they work together to get a better understanding of an extremely complex subject.
But it’s hard to escape the irony that the resources spent on the county’s anomalistic winter ozone problem mean researchers will wish for the problem to be present.
As strange as it might be, an active 2009 ozone season may be what’s needed to mitigate Sublette County’s dubious distinction as the world’s winter ozone capital.
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