SUBLETTE COUNTY – The state’s winter ozone forecasting season for the Upper Green River Basin officially ended Friday, March 31, after an unexpected series of elevated ozone-level action days earlier this year.
In January, the Wyoming Department of Environmental Quality’s (DEQ) Air Quality Division (AQD) as well as Upper Green River Basin (UGRB) residents were caught by surprise when ozone levels rose alarmingly close to or exceeded the current federal standard of 70 parts per billion (ppb) during 1- and 8-hour periods.
Data from the winter of 2005-2006 had showed previously unseen high ozone levels – an unrecorded winter phenomenon – exceeding the Environmental Protection Agency’s (EPA) then federal standard of 80 ppb for 8-hour values, continuing through the winters of 2008, 2009 and 2011. In 2008, the EPA dropped the standard to 75 ppb and in 2015, to 70 ppb.
After years of winter ozone study, in 2009 the AQD requested voluntary ozone contingency plans for operators and agencies and those are still in place. However, in 2011, the Boulder level rocketed to 123 ppb.
In 2012, the UGRB was designated as “non-attainment” for the EPA’s ozone standard, attributed to inconsistent technologies and practices in the local oil and gas fields.
The UGRB’s ozone exceedances occurred during winter but not summer, setting off calls for new voluntary and regulatory actions. It was discovered sunlight passed through “precursors” nitrogen oxides (NOx) and volatile organic compounds (VOC) onto snow-covered sagebrush flats, “baking” them into ozone and other toxic gases.
With the EPA nonattainment designation, DEQ, other agencies and operators were tasked with bringing the UGRB back into compliance. An ozone advisory task force suggested updating annual strategies and making new emissions rules.
However, for the next four winters of 2012 through 2015, high winter ozone levels disappeared, according to AQD data. The DEQ passed new emissions-source rules and this year, operators are required for the first time to file leak-detection reports.
AQD discontinued its daily forecasts last winter, unless its scientists detected conditions showing probabilities for rising ozone the next day and issued a warning.
However, although activity is much slower than a decade ago, this first quarter brought very unexpected ozone spikes.
From January through March, preliminary data show the 8-hour ozone values exceeded the federal standard of 70 ppb on seven days at the Boulder monitoring station, ranging from 72 ppb in January to 85 ppb on March 4.
Also on March 4, the Pinedale monitoring station measured 78 ppb, the Daniel station 79 ppb, the Big Piney station 73 and the Juel Spring station 74, according to the AQD at a March 16 public meeting in Pinedale
Those 8-hour levels reflect the average of each hour’s measurements, and the same preliminary data show 1-hour levels that spiked on March 4 at 90 ppb in Boulder and around 78 ppb in Pinedale, according to graphs presented by DEQ director Todd Parfitt.
Parfitt explained that the EPA takes each station’s fourth-highest daily level and averages them together when considering attainment, which on March 16 stood at 73 ppb.
Recent warm weather might have mitigated the ozone issue for this winter although a lot of snow remains on the ground and storms are possible at any time.
In the meantime…
One new piece of ozone legislation, HR 806, introduced in the U.S. House Feb. 1, tries to address some air-quality shortcomings for western states. Titled the Ozone Standards Implementation Act of 2017, its purpose is “to facilitate efficient state implementation of ground-level ozone standards and for other purposes.”
It calls for amendments to the Clean Air Act, states’ review of attainment (or not) of 2015 ozone standards of 70 ppb by Oct. 26, 2024, as well as a 10-year cycle “for all criteria air pollutants” with an EPA moratorium on setting a new ozone standard before Oct. 26, 2025.
The bill also calls on the EPA administrator to recognize states’ efforts and undertake studies about air-quality issues such as “exceptional events,” emissions originating from outside the U.S., natural and manmade ozone and other pollutants, especially in western states.
It states, “Prior to establishing or revising a national ambient air quality standard, the Administrator shall request, and such committee shall provide, advice … regarding any adverse public health, welfare, social, economic, or energy effects which may result from various strategies for attainment and maintenance of such national ambient air quality standard.”
The legislation aims the EPA toward the entire country, state by state, and calls for studies to include western states’ situations, according to AQD director Nancy Vehr.
Vehr testified on March 22 before the House Committee on Energy and Commerce’s Subcommittee on Environment.
“Before I discuss ozone, I want to share three facts to help you understand Wyoming’s perspective,” Vehr said in opening.
Those are that Wyoming is the ninth largest state with the smallest population, that it is second only to Colorado in mean elevation, and third, it is blessed with “amazing and abundant natural resources” and protects those resources while “provid(ing) for responsible energy production.”
She outlined the history of the UGRB’s “wintertime ozone in Wyoming” without naming this location.
“Our experience highlights why a one-size-fits-all approach to ozone is not defensible,” Vehr said. “Wyoming’s experience differs greatly from EPA’s traditional ozone focus on low elevation, densely populated urban areas with summertime issues.”
HR 806 “recognizes and provides for study of ozone formation in rural areas and in the winter” and also seeks to address “background ozone” as well as “internationally transported ozone,” she testified.
“When EPA proposed the 2015 standard, it dismissed high-elevation site data as an outlier, even though it recognized that ‘background concentrations are highest at high elevation,’” she said.
“Exceptional events” should be defined more clearly and the very costly demonstration process streamlined, Vehr added. “In addition, EPA must act on exceptional event submissions.”
“Between 2011 and 2014, Wyoming submitted 46 exceptional event demonstrations showing that air-quality standards had been affected by high winds, wildfires and stratospheric intrusions,” she stated. “However, EPA did not act on Wyoming’s demonstrations.”
Her final point in her five-minute statement is that with “interstate ozone transport,” the EPA applies eastern state modeling to the west.
“Early and meaningful engagement with western states is also critical,” Vehr said. “Failure to do so and instead apply a one-size-fits-all approach may adversely affect Wyoming and the health of her citizens.”
HR 806 was introduced by Texas Rep. Pete Olson (R) and is co-sponsored by 21 mainly Republican House members from Texas, Ohio, California, Louisiana, North Dakota, Missouri, West Virginia, Kentucky and Georgia.