SUBLETTE COUNTY – It could be a low-key winter for ozone formation in the Pinedale Anticline and Jonah Field with only drilling rig planned for the season.
State officials and operators presented updates and forecasts at the Wyoming Department of Environmental Quality’s annual pre-winter ozone season meeting Dec. 15. The Zoom meeting was open to the public.
This is the 15th year that DEQ has been monitoring ozone and its precursors of volatile organic compounds and nitrous oxides, which DEQ staff calls “anthropogenic” or manmade.
Ultra Petroleum Energy had no drilling or completions last winter and will have none this winter, according to Kelly Bott.
Jonah Energy’s Howard Dieter said Ensign is running one natural-gas-powered rig with a battery backup, emitting much less methane than diesel.
Both operators said their own inspectors are always checking for leaks and replacing more pneumatic devices.
But while last winter’s industry activity was as low, ozone exceedances still occurred in January, February and March.
DEQ’s Darla Potter first reviewed 2020 in the Upper Green River Basin, pointing out that the Boulder air-quality monitoring station’s high ozone levels led to three “ozone outlooks” or forecasts that pollutants, snow cover and sunshine could create ozone. There were five ozone action days in those two months as well.
The federal standard for ozone is 70 parts per billion and above that, public and energy employees with breathing problems can face increased breathing problems.
Days with exceedances are noted and the fourth highest reading is used to figure an average called a “design value” that the Air Quality Division hopes is .70 or lower.
“Boulder is the design value site where it is expected to see the highest (ozone measurements),” said Cara Keslar of the DEQ’s AQD. In 2018, the design value was .63 ppb, in 2019 it was .72 and for 2020, it was .70, she said.
The Upper Green River Basin was designated “nonattainment” in 2008 with .75 ppb and that was partially cleared by the Environmental Protection Agency by reduced numbers in following years. In 2015, the previous standard was met. “We are now in marginal attainment,” Keslar said.
DEQ’s air-quality monitoring sites are shown live and with past data accessible on the Wyoming Visibility Network, or WyVisNet, which has new features added for more immediate information.
One example is the home screen now shows “quick popups” for current ozone levels; another is being able to view site images for the past several weeks to see what meteorological conditions existed, said AQD Director Nancy Vehr.
Vehr also touted WyVisNet’s “historical data concentration” to replace “recent data” graphs. Also, data graphs did not show real numbers, only lines, and now one-hour and eight-hour will be provided, Vehr said.
“You can load any day in the past back to December 2017,” she said. “If you have a request for a (different) report you want to see often, contact us.”
Carmel Kail, member of Citizens United for Responsible Energy Development or CURED, said that she computed the design value at .72 ppb – “Is the Upper Green River Basin essentially in nonattainment?”
Vehr said the AQD looks to the third year and the DEQ is now entering a new season. “We’re in 2020 and the design value is current at .70 … at the Boulder station.”
The EPA recognized the Upper Green River Basin as meeting the .70 ppb ozone attainment status in 2015 and agreed to designate attainment by county, Vehr said. “Areas without monitors were designated ‘unclassifiable.’”
To be formally redesignated means a lot of technical work, Vehr said, “We have not gone through the exercise or work to get the area redesignated by EPA to attainment status – the EPA recognizes it as meeting it.”
The process could begin soon, she said. “We anticipated sometime in 2021 to begin the work to formally seek RPA’s recognition to change the status back to attainment.”
“We’re in the situation where the Upper Green River Basin and southwest Wyoming look on average for temperatures and precipitation,” Potter said. “Unfortunately we don’t have a crystal ball to see how these factors will come together. It is a ‘time will tell’ situation.”
DEQ again has two inspectors in the field testing engines and emissions – a third inspector’s position won’t be filled due to statewide budget cuts.
For more about the Upper Green River Basin’s winter ozone, visit http://deq.wyoming.gov/aqd/ozone/ or wyvisnet.com.