From the pages of
Sublette Examiner
Volume 8, Number 46 - February 5, 2009
brought to you online by Pinedale Online

DEQ issues first ozone alerts of season

by Derek Farr

This week the Wyoming Department of Environmental Quality (DEQ) issued its first ozone advisories of the season for Wednesday and Thursday.

The advisories, issued in conjunction with the Wyoming Department of Health (WDH), are based on an evaluation of weather forecasts that predicted a strong temperature inversion and light winds.

Those meteorological conditions as well as clear skies and an uninterrupted snow cover create winter ozone. When the snow cover amplifies the sun’s ultraviolet rays and an inversion concentrates the county’s air emissions, the mixture is cooked into the hazardous air pollutant ozone.

While an advisory is no guarantee of ozone, if the pattern is the same as 2008, ozone levels will build rapidly into the afternoon and dissipate as the sun goes down.

But during those periods of elevated ozone, some people should use caution.

According to the WDH Web site, possible effects of ozone pollution are “shortness of breath, coughing, wheezing and eye and nose irritation.” Ozone is especially dangerous to older adults, children, asthmatics and persons with other chronic respiratory ailments.

The WDH suggests people at risk should limit their time outdoors during high-ozone days, and “those experiencing tightness in the chest, coughing, wheezing and shortness of breath should contact a medical professional.” For more information, visit the WDH at

The DEQ posts current ozone levels at Data from the Daniel, Pinedale and Boulder monitoring stations are available at that site. Last year the Boulder site recorded an ozone eight-hour average of 122 parts per billion (ppb) – the maximum allowed by federal law is 75 ppb. This year is the Pinedale site’s first year of operation.

Voluntary actions

As part of the ozone advisory, the energy company EnCana began voluntary steps to reduce its activities in the Jonah field, according to Randy Teeuwen, EnCana community relations advisor.

“We are taking this very seriously,” he said. “We’re doing what we can to mitigate it.”

It is widely believed much of the air pollutants are being produced by Sublette County’s extensive gas development. EnCana has a six-step action plan designed to reduce emissions. Those actions are: minimizing vehicle emissions, minimizing the use of ancillary equipment, postponing non-essential construction activities, postponing non-essential maintenance activities, postponing the initiation of well fracturing/ completion activities and postponing initiation of blowdown activities.

“Our long-term goal is to eliminate emissions,” he said. “But the first step toward eliminating emissions is reducing them and we’ve made significant progress in doing that.”

Teeuwen says a combination of new technology, new engineering experience and new employees have come together in the last couple of years to make “significant progress.” He said EnCana begins its voluntary action plan as soon as DEQ issues an ozone warning and even though some activities are postponed the actions should not have an adverse affect on Jonah Field workers.

“We don’t anticipate it will affect us so somebody will lose their job,” he said. “There are other things that people will be working on that don’t contribute to ozone conditions.”

What can you do?

Ozone is created by the combination of nitrogen oxides (vehicle exhaust) and volatile organic compounds (fumes from petroleum products) both of which are emitted by driving and gassing vehicles.

To reduce the precursors for ozone, average citizens can help by carpooling, minimizing driving, refueling vehicles in the evening hours and postponing the use of solvent-based products.

Last year ozone was detected in Sublette County from February to April. On Friday a weather disturbance is forecasted to pass through the area, which should eliminate the possibility of excessive ozone formation.

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