NOx and VOC emissions from oil and gas facilities are the precursors for possible ozone spikes in the Upper Green River Basin. (Dustin Bleizeffer/WyoFile)

PINEDALE — Clean-air advocates here are calling for corrective action following a winter of high ozone pollution readings, but a state regulator is demuring, saying federal rules are “not explicitly clear” about requiring a fix.

Wyoming DEQ is still confirming readings from pollution monitoring stations in Sublette County, said Darla Potter, Wyoming Department of Environmental Quality’s air quality resource program manager. Preliminary results from monitoring stations show ozone pollution exceeded federal standards 10 times this winter.

Federal regulators deemed air quality in the area to be “non-compliant” with national ozone concentration standards in 2012. That finding prompted the development and implementation of a state plan to keep levels of the dangerous chemical within safe ranges — below 70 parts per billion. An air monitoring station in Boulder exceeded that measure nine times this winter, reaching a rolling eight-hour high of 105 ppb. The eight-hour measure at a station in Daniel reached 72 ppb once.

This DEQ ozone monitoring station relays information from a residential district in Pinedale. (Angus M. Thuermer Jr./WyoFile)

“We did in fact end up with 10 days that exceeded the level of the 2015 ozone national ambient air quality standard for that 8-hour averaging period,” Potter said at an annual meeting of Pinedale-Anticline area oil and gas field operators.

All told in the 2019 January-through-March season, Sublette and parts of Lincoln and Sweetwater counties saw five ozone outlook or warning days, 16 ozone action days requiring industry to reduce activity, and 10 exceedance days when ozone surpassed federal guidelines.

Some Pinedale residents, including members of the community watchdog group Citizens United for Responsible Energy Development, believe this year’s readings violate the state’s obligation to maintain a running three-year clean record and should again put the area into a federal “non-attainment” category under the Clean Air Act.

A non-attainment classification would require the state to develop and implement a new plan to curb the pollution, potentially slowing energy development or requiring expensive pollution-control measures.

But Potter said the issue is not that simple. DEQ hasn’t figured out whether this winter’s high readings, if confirmed, would lead to a federal non-attainment decision.

“Regulations that EPA puts out are not explicitly clear as to what happens in a situation such as this,” she told the meeting group via telephone at its Pinedale session Thursday, “So that is one of the things we are still looking into — and combing through — that regulatory language.”

The DEQ is “beating around the bush” said Elaine Crumpley, a founding member of CURED. “When they say they don’t know what the regulations are, that is a shocker to me,” she told WyoFile in an interview. “They’re the ones who made the regulations based on the EPA [standards]. It should be cut and dried.”

“My concern is they are going to change the goal line. They’re going to make some kind of change so they are not in non-attainment. That would be wrong.”

Un-CURED after 14 years

Ozone — a molecule composed of three oxygen atoms — occurs naturally in the upper atmosphere where it serves as a kind of sunscreen for the panet, blocking deadly UV rays. But when it concentrates near the Earth’s surface it can can cause a host of dangerous breathing ailments, especially among children, the elderly, and people with existing respiratory conditions.

It forms when precursor compounds combine with sunshine in a cold, still setting like the Upper Green River Basin in winter. Those precursors include nitrogen oxides and volatile organic compounds — both of which are linked to oil and gas development and associated activities.

Oil and gas equipment associated with fracking located at the Pinedale Anticline Field. (Dustin Bleizeffer/WyoFile)

Nitrogen oxides come from combustion, the BLM’s Air Quality Liaison Janet Bellis told the group.

Volatile organic compounds are “generally from [oil and gas] production … or any kind of leakage.” Bellis said. VOCs are compounds like formaldehyde, benzene, acetone, butanal, ethanol and alcohol, or things like paint thinner that easily become gasses.

A big snowpack may play a role. “It looks like snow plays a large part in causing the meteorological conditions that are conducive to ozone formation,” she said.

In addition to the eight-hour average of 105 ppb on March 21 at Boulder, the DEQ monitor recorded a one-hour reading of 130 ppb on March 20.

Ozone spikes between 86 and 105 ppb for an eight-hour average are considered “unhealthy” and “everyone may begin to experience health effects,” the DEQ writes on its website. “Members of sensitive groups may experience more serious health effects.”

During such periods, people with lung diseases, children, older adults, and people who are active outdoors “should avoid all outdoor exertion,” the DEQ writes. Everyone else, “should limit outdoor exertion,” its website says.

A 106 ppb reading – one part per billion above what was measured at Boulder, would indicate a “very unhealthy” designation. At 106 ppb and above, persons with breathing problems should “avoid all outdoor exertion” and everyone else should “reduce prolonged outdoor exertion,” the DEQ writes.

Raw, dry throats, nosebleeds

Pinedale resident Isabel Rucker wrote Gov. Mark Gordon on March 22 that she’s had, seen and heard of deleterious effects she attributes to ozone, according to a copy of an email she supplied to WyoFile.

“I have personally experienced a raw dry throat and cough,” her letter reads. “My husband has experienced a long dry cough when working in these conditions. My friend has had to put her child on asthma medication. I have heard of others having respiratory problems, nosebleeds and other issues.”

These graphs created on the Wyoming DEQ website show preliminary eight-hour ozone readings at the Boulder monitoring station in blue and one-hour readings in red. The peaks show a measure of 105 parts per billion on the eight-hour chart March 21 and 130 ppb on the one-hour chart March 20. The DEQ cautions that “these data have not been validated by human review and may contain errors. These data may not have all 40 CFR Part 50 data handling procedures applied and are not directly comparable to the [National Ambient Air Quality Standards].” (Wyoming DEQ)
She also offered the governor a theory on the ozone’s source and a potential solution.

DEQ’s Potter said the Ozone levels near Boulder were unique this season. At the Boulder monitoring station, “concentrations [were] quite different than any other station,” she told the group.

Oilfield operators at Thursday’s meeting said they didn’t have an obvious culprit — they saw no unusual incidents in the area that might cause a spike.

“We had some localized impacts around Boulder,” Kelly Bott, energy company Ultra’s Petroldum Corp’s regulatory and environmental manager, told the group about the readings. But field checks “confirmed that all of our leaks were very minimal.”

“There was nothing anomalous, nothing unusual,” Bott said, “nothing they found to be errant.”

Boulder, however, is the site of an uncovered pit that holds drilling wastewater for the Pinedale Anticline Field, Rucker wrote Gov. Gordon. “It has been proven that their facility is releasing a plume of toxic ozone causing chemicals in a report that you funded and was published in 2015,” she wrote.

A facility labeled Anticline Disposal on Google Earth that a clean-air advocate believes might be responsible for some of the ozone pollution at the Boulder monitoring station (Google Earth)

The Boulder monitor “is constantly the worst in the area and very close to this plant,” she wrote. “[I]f we could cover the ponds we probably wouldn’t have as many of these ozone days.”

The pit’s permit, last renewed for five years in 2014, should be up for consideration again this year, Rucker wrote. “I request that you do not renew the permit for Anticline Disposal until they submit a plan and date for covering all of their wastewater ponds.”

Health, economy both suffer

The DEQs five “ozone outlooks” this season — warnings of anticipated high air-pollution levels — enabled DEQ “to give everybody in the Upper Green River Basin advance-notice,” Potter said. Tasks that operators and others knew had to be put off during expected “ozone action days” could be completed sooner, or other accommodations made.

The DEQ called for 16 “ozone-action days” during which oil and gas field operators and federal workers implemented plans to reduce pollution-causing activities. That included postponing some work, delaying deliveries, car-pooling and fueling vehicles at night.

“I believe this winter we had the longest stretch of ozone-action days that we’ve issued since we started that program,” Potter said.

Rucker’s letter to Gov. Gordon, in addition to outlining health worries, noted economic impacts from ozone-action days.

“Ozone action days can result in field workers being sent home without pay,” she wrote. “My husband and other workers have experienced this. It results in companies slowing operations and potentially losing profits.”

The Upper Green River Basin non-attainment area covers parts of three counties where air quality is monitored at five stations. (Wyoming DEQ)

Operators echoed those sentiments Thursday.

“I think this year was really a reminder for folks how impactful this is for people,” said Ultra’s Bott. “We deferred deliveries until after-hours. We don’t have vendors and things coming out to locations on ozone days.”

Ultra employs 400 workers locally, she said. For some of those, “when they’re suspended [on ozone-action days] they’re staying home for the day.”

Ultra has three active rigs in the area, Bott said. The company would like to see seven. “We would love to ramp up,” she said.

Drilling Edge, an energy information company, lists 25 operators in Sublette County and more than 10,000 wells, 6,707 of which are producing. In the Pinedale Anticline Field about 3,300 wells have been drilled with plans for approximately 5,000 by 2040, Bellis said.

Other development is underway. The BLM has approved Jonah Energy’s plans to drill 3,500 wells in the Normally Pressured Lance Field, a neighbor to the Pinedale Anticline and Jonah fields.

7th grade science and serendipity

CURED co-founder Crumpley was a 7th grade science teacher in 2005 when she engaged student Tracey McCarty in a project. Residents suspected ground-level ozone was polluting the area, but nobody — in the whole country — knew of what’s now called winter ozone formation.

Crumpley and McCarty figured out how to make paper indicator strips that would change color when in the presence of ozone — like a litmus test that indicates general acidity of a substance. McCarthy’s papers became a darker purple the more ozone they were exposed to.

“She put all these papers out in different areas in the Upper Green [River drainage] and came up with significant hits of ground-level ozone,” Crumpley said.

McCarty won the local science fair in the spring of 2006 and went on to the state competition.

“She presented this at the state science fair and won first place,” Crumpley said. “The BLM had a fit.”

Tracey McCarty’s seventh grade experiment in 2005 involved making test strips that would change color after being exposed to ozone. (Elaine Crumpley)

The DEQ was also monitoring air quality in the area at the time, but they usually shut down their equipment during the winter when oilfield activity waned, Cara Keslar, a DEQ monitoring section supervisor told WyoFile in 2014. But during the winter of 2005, nobody was available to turn the monitors off so “we just kind of left them on,” she said.

She and a technician at the EPA noticed spikes in ozone readings. “It was me and the EPA,” she said.

“EPA called me up; ‘Hey, did you notice the [spikes],’” she said. “Well, I noticed something.”

“It could be real,” she thought, or a malfunction. But the readings were high on two monitors. “We saw it at both stations,” Keslar said, concluding “it’s not a malfunction.”

It took a while for Wyoming and the federal government to agree to pollution control plans, Crumpley said. In 2011 CURED filed a notice of intent to sue to enforce the Clean Air Act. In 2012 the EPA acted and designated parts of Sublette, Lincoln and Sweetwater counties a non-attainment area.

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Wyoming launched “a multitude of ozone strategies” including “numerous regulatory control measures,” according to DEQ documents. In doing so, it retained primacy — local control — of the means and methods of meeting federal air-quality standards.

Since then — but before this winter — Wyoming has met the requirement that it maintain a three-year clean bill of air health, and in 2016 received a “determination of attainment” with regard to the 2008 standard of 75 ppb (the federal government lowered the standard to 70 ppb in 2015). But several elements, in addition to recent years’ ozone levels, cloud the issue.

Tracey McCarty today (Elaine Crumpley)

For one, “attainment” does not mean re-designation of the area as pollution-free. Re-designation “is much more extensive” the DEQ writes in a 35-page pamphlet published in 2018. Only when more requirements are met, perhaps over a decade, would the federal government formally change the area’s classification.

Oil- and gas-field operators have made innovations in the area, including installing a liquid-gathering pipeline system in the Pinedale Anticline field to reduce vehicle traffic. Ultra eliminated more than 100,000 trucks trips last year through the liquid gathering system, Bott told the group.

Pumps are being converted to run on solar energy. Rigs are powered by less-polluting technologies and Jonah Energy is experimenting with on-site and drone-mounted emission detection sensors. “Thousands of tons of volatile organic compounds and nitrogen oxides have been offset and reduced,” DEQ documents say.

Crumpley agrees. “They have done some good things,” she said. “They need to do some more good things, not change the rules.”

Angus M. Thuermer Jr. is the natural resources reporter for WyoFile. He is a veteran Wyoming reporter and editor with more than 35 years experience in Wyoming. Contact him at or (307)...

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  1. What’s also interesting, normally Pinedale’s O3 (23) is lower than Jackson(32), Grand Teton(44) and Yellowstone(51). ( these are currant 8 hr. readings). People are working hard to deal with this winter anomaly, so lets not throw the baby out with the bathwater of shallow journalism

  2. How does all the wood burning and pellet stoves affect the ozone readings ? just curious because that is what chokes me down here in Lander more so than anything else. Also your pictures with this article are fairly misleading. The first picture is of a drilling rig, not fraccing equipment. The picture of the disposal pits doesn’t show any flare stacks which would be burning gas, I doubt that the ponds evaporation is really affecting the ozone.

  3. Unfortunately until the air quality in Jackson, Casper, Cheyenne, Cody,Gillette reaches a level that affects the economy or health of the residents that live in the areas that have been impacted by the development of the oil and gas fields then the powers to be hold the aces. Wyoming resisting change since 1890.