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Utah Air Quality Has a Lot to Do with the Weather

A recent air quality study – conducted by NOAA, the Utah Department of Environmental Quality, Utah State University, and other university researchers with input by the U.S. EPA, BLM, the counties, and Western Energy Alliance – examined what’s known as “winter ozone” in the Uinta Basin of northeastern Utah. The study was designed, among other things, to help researchers better understand atmospheric chemistry in the region and key sources of air emissions, data that would in turn inform future discussions about mitigation strategies.

Oil and natural gas development is the largest industry in the Uinta Basin, and operators and service companies have been actively reducing emissions through voluntary agreements with BLM and other regulators. As part of that commitment, Western Energy Alliance and Uinta Basin operators are contributing substantial funds for this study and the follow-on study through 2013 in order to obtain a better scientific understanding of winter ozone formation, and to determine the most effective emissions reductions strategies. Without that fundamental scientific understanding, regulators could be in a situation of imposing requirements that kill jobs while doing little to nothing to address winter ozone – or could even make the situation worse.

What the study found with respect to the weather is a perfect example of why that approach is necessary. As the paper notes:

“…winter ozone formation requires (1) snow cover to increase available sunlight that drives ozone – forming photochemical reactions and (2) strong temperature inversions to decrease atmospheric mixing and allow ozone and its precursors to accumulate in a shallow layer of the atmosphere near the ground.” (p. 1)

In 2012, certain weather conditions – temperature inversions with sufficient snow – were not in place, and although oil and gas production actually rose, ozone levels were well below the levels at which EPA considers there to be any health impact. In fact, median ozone concentrations during the 2012 winter were 28-46 ppb, well below the federal health standard. As the study further observes:

“Unlike the previous two winters, ozone concentrations during UBOS 2011-12 were well below the National Ambient Air Quality Standards (NAAQS), peaking at an eight-hour average of 63 ppb, and snow cover and multi-day temperature inversions were virtually absent.” (p. 1)

During the two previous winters, meanwhile, measured ozone values were roughly twice what they were in 2012.

How to explain that? Well, during the 2009-2010 winter, there were 94 days with snow depth exceeding 50mm, and there were 81 such days in 2010-2011. There were zero such days during the 2011-2012 winter. Indeed, as the study stated explicitly: “Snow cover is a necessary condition for formation of winter ozone episodes.”

Encapsulating all of this information, the study concluded:

“Ozone precursor emissions inventories showing differences in the 2009-10, 2010-11, and 2011-12 winter seasons currently are not available. However, drilling and production data from the Utah Division of Oil, Gas, and Mining (Utah DOGM, 2012) suggest that activity in the Uintah Basin increased between 2009 and 2012 (Figure 4).  Furthermore, no significant new emission control measures were introduced during this period. It is unlikely, therefore, that overall emissions would have decreased so significantly as to account for the lower ozone observed in 2011-12 compared to 2010-11.” (p. 12; emphasis added)

The upshot? Yes, oil and natural gas development is a major industry in the Uinta Basin, and the study mentions that a good portion of the observed emissions came as a result of it. But it’s also clear that what occurs naturally – snow cover, changes in atmospheric conditions, and even wind severity – is necessary for ozone formation in the region to occur.

That’s not to say that the industry is going to stop looking for ways to reduce its emissions; quite the contrary. But it does highlight why an official with Utah’s Air Quality Administration, for example, said regulators are not going to impose any new rules at this time, as more study needs to be completed. Jumping to conclusions, or taking a “shotgun approach” as the Uintah County commissioner put it, is clearly the wrong prescription for solving the ozone problem in the Basin.

And yet, despite all of the information contained in the actual report, including but not limited to everything explained above, the headlines that popped up this week sought to tell a very different story. To wit:

  • Denver Post: “Study finds oil and gas drilling caused air pollution in Uintah Basin”
  • Salt Lake Tribune: “Study finds oil and gas causing pollution problem in eastern Utah”
  • Platts: “Utah ozone study finds energy industry is chief source of emissions”
  • E&E News: “Drilling is primary cause of ozone pollution – study”

Only the Deseret News in Salt Lake City saw fit to explore and explain what the researchers actually concluded, running a story under the header: “Uintah Basin ozone study points to weather as driving factor.”

It seems most news outlets, like ozone formation in the Basin, are driven heavily by prevailing winds.


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