SALT LAKE CITY — Multiple groups are renewing their push for the EPA to declare the Uinta Basin's oil- and gas-producing region in both Utah and Colorado as "non-attainment" with federal clean air standards because of high winter ozone concentrations.
A petition filed Wednesday by WildEarth Guardians, Utah Physicians for a Healthy Environment and the Southern Utah Wilderness Alliance urges the Environmental Protection Agency to act now rather than later to accelerate smog-reduction efforts in the region.
The petition, which is separate from a lawsuit already filed against the EPA by the groups, asks for the dirty air designation and for revisions to Utah and Colorado state plans to address ozone.
"The need to undertake these actions is critical," the groups' petition said. "Ozone, considered the key ingredient of smog, is a significant threat to public health and welfare."
The groups say new data from 2013 bolster the need for agency action to protect public health, with monitoring stations in both states that show impacted counties are either violating, near violating or "grossly exceeding" national ozone standards.
"The fact that both the Colorado and Utah portions of the Uinta Basin share common air quality patterns is underscored by the fact that both areas share common industrial characteristics and sources of air pollution, primarily extensive oil and gas development, the source of the vast majority of ozone precursors in the region," the petition reads.
The groups note that regional ozone levels reached extremely high levels, with Vernal eclipsing the federal threshold at one point by 60 percent. In its annual report, the Utah Department of Environmental Quality noted that ozone values exceeded the threshold for 22 days in Vernal and 29 days in Roosevelt. Individual episodes of elevated ozone ranged from three to nearly 15 days in length during the 2013 study period.
The state, however, argues that insufficient data exist — results that go back through a three-year period — to merit the EPA designation and that such an action would be premature given an ongoing multiyear study.
In a brief filed in the court case two weeks ago, the state insisted the EPA's conclusion that the region is "unclassifiable" should stand because the groups are trying to wrongly assert that "any" data is sufficient for action.
"It is important to re-emphasize that the standard is not based on individual exceedances, but an exceedance by the fourth-highest daily maximum eight-hour concentration, averaged over a three-year period," the brief argues. "Not only is it irrelevant to the determination if there are single exceedances on a given day or over a given period, but without three years of certified, quality assured data, EPA cannot reach an attainment/non-attainment designation for ozone."
Utah is one of nearly a dozen entities including federal agencies, university scientists, the oil and gas industry and impacted counties that are trying to determine why ground level ozone persists in the region in the winter. In what has been described as the largest and most expensive air quality study in the state, atmospheric scientists, chemists and others are analyzing the conditions that must exist for ozone formation.