The mystery behind the wintertime ozone problem that has plagued parts of the Intermountain West is deepening as pollution levels during the first quarter of 2011 dropped in northeast Utah but increased in southwest Wyoming.
Ground-level ozone exceeded federal health standards in northeast Utah's Uintah Basin on 26 days between January and March, according to air monitoring data compiled by U.S. EPA. That figure was down from 37 days of ozone exceedances recorded in the basin for the first three months of 2010.
But in Wyoming, after two years of clean winter air in the Upper Green River Basin, EPA monitors registered 13 days between January and March when ozone levels exceeded the eight-hour health standard of 75 parts per billion (ppb). That includes a March 2 ozone reading of 124 ppb -- higher than the worst ozone levels recorded last year in Los Angeles.
And even though the Uintah Basin saw fewer bad ozone days early this year, the region did experience significant ozone spikes on days when the pollutant was a problem. That included a Feb. 16 eight-hour average of 146 ppb, nearly twice the federal standard and potentially dangerous for even healthy adults to breath, said Carl Daly, chief of the air permitting, modeling and monitoring unit in EPA's Region 8 office in Denver.
High concentrations of ozone can trigger asthma attacks and inflame conditions for people with bronchitis, emphysema and other respiratory ailments.
"An ozone reading of 146 puts the Uintah Basin in the same category as the worst ozone locations in the country. The values are astronomical," said David Garbett, a staff attorney with the Southern Utah Wilderness Alliance in Salt Lake City. "This year confirms that wintertime ozone is a serious problem in the Uintah Basin."
Wyoming and Utah officials are actively working to address the problem. Officials have noted that ozone precursor pollutants -- nitrogen oxides (NOx) and volatile organic compounds (VOCs) -- are emitted in large quantities by the region's oil and natural gas drillers (Land Letter, Sept. 30, 2010).
Wyoming's Upper Green River Basin, for example, is home to the massive Jonah and Pinedale Anticline gas fields that contain thousands of drilling wells. And drilling in the Uintah Basin has grown dramatically in the past decade.
"We recognize that definitely the main contributor to the emissions that are out there is the oil and gas industry, and we're trying to control those," said Keith Guille, a spokesman for the Wyoming Department of Environmental Quality.
Guille said the state has developed a contingency plan that includes curtailing drilling activity on high ozone advisory days, as well as working with the industry to install advanced pollution controls on older drilling equipment.
In Utah, where the wintertime ozone was identified as a problem just last year, regulators say they are addressing the problem. But it remains unclear what strategies will be most effective in bringing ozone back into compliance with the federal health standard, said Brock LeBaron, manager of the Utah Division of Air Quality's technical analysis section.
"But something's going to have to happen. I don't think we can just sit here and study the problem," LeBaron said. "There's going to have to be a parallel track of research and reducing emissions."
For its part, the oil and gas industry "is very committed to working with EPA and the states on wintertime ozone over the long term to ensure protection of air quality while enabling energy development, job creation and economic growth," Kathleen Sgamma, director of government and public affairs for the Western Energy Alliance, said in an emailed statement.
Human and natural causes
The nagging questions around wintertime ozone stem in part from the fact that ozone is traditionally a summer problem, when emissions from industry smokestacks and automobile tailpipes mix in sunlight and heat to form the odorless gas.
Regulators are also puzzled by the inconsistency of wintertime ozone. For example, the phenomenon was first discovered in Wyoming's Upper Green River Basin in 2008, Guille said, then dropped off in 2009 and 2010 before making a resurgence in 2011.
Daly said the same pattern was seen in the Uintah Basin.
"We were carefully watching to see if last year was an anomaly," Daly said. "It's either a two-year anomaly or this is the standard rather than the exception."
Residents of Pinedale, Wyo., near the Pinedale Anticline gas field, certainly hope 2011's ozone readings do not become the norm.
Pinedale Mayor Stephen Smith said the air quality was so bad in early March that local doctors reported an uptick in patients reporting respiratory problems. One of those patients -- a young, healthy runner -- complained on one high-ozone day of nosebleeds and throat pain.
Smith said he is certain emissions from the region's oil and gas rigs are a major factor. "To believe otherwise is naive," he said. But he added industry has acknowledged its role and taken real steps to address the problem.
"They're doing their fair share. They reduce traffic on bad days, and most have [installed] technology on their equipment to cut pollution, though not all," he said.
Scientists also believe that an unusual weather pattern affecting both basins is helping to drive ozone to potentially dangerous levels during the winter months. The pattern is marked by stagnant air that allows emissions to collect in the lower atmosphere and then be converted into ozone by sunlight and heat reflecting off snowpack on the ground.
John Robitaille, vice president of the Petroleum Association of Wyoming in Casper, Wyo., said such natural phenomena are likely the main contributor to the problem. "We've seen emissions levels drastically go down over the course of the last several years," he said. "But it seems when these particular weather patterns occur we see the ozone."
Smith said his constituents in Pinedale just want the issue resolved and the region's air quality restored.
"People on the ground here have gone from concerned to being irate," Smith said. "There's a lot of serious concern here on the ground. I don't have a solution. And I'm not against industry. Industry has done a lot of great things and they've really stepped up to the plate. But it's my job to represent the concerns of the people here, and people are concerned."
If the problem persists, the Wyoming and Utah basins could fall out of compliance with the national ambient air quality standard (NAAQS) for ozone, requiring state regulators to develop detailed plans for reducing ozone precursor pollutants by an EPA-set deadline.
Further complicating the issue is EPA's expected announcement this summer that it will substantially toughen the ozone health standard to as low as 60 ppb. Such a change could have major implications for Uintah County, where in addition to the 26 days of exceedances of the current standard from January to March 2011, the basin saw 21 days when monitors registered ozone at between 60 and 75 ppb.
Sgamma, the Western Energy Alliance official, said EPA's proposed new standard could cripple the oil and gas industry because it would allow for almost no additional ozone formation beyond natural background levels. "Data show that even in rural areas with no energy development or other sources of emissions, background ozone is already at or above the low range of the proposed new ozone standard," she said.
Environmentalists, however, say a tightening of the ozone health standard is long overdue. Groups have already filed challenges to several drilling projects approved by the Bureau of Land Management based on concerns that new drilling will exacerbate the ozone problem.
One such challenge involved BLM's approval of Denver-based Enduring Resources LLC's Rock House Project, which originally called for developing 60 natural gas wells on federal, state and private lands from 24 well pads, including seven existing pads. As part of a settlement agreement with environmental groups, Enduring Resources agreed to scale back its project footprint and implement management practices to reduce ozone levels in the Uintah Basin (Land Letter, April 7).
Stephanie Howard, a BLM environmental coordinator in Vernal, Utah, said the agency is working with EPA to develop an air resource management strategy for the basin that will address ozone and other air quality concerns.
But Garbett, the Southern Utah Wilderness Alliance attorney, said BLM continues to approve projects that will worsen the basin's ozone problem, forcing groups to sue or negotiate settlements with industry to protect air quality.
"We still have not seen significant change in the behavior of BLM. Their response seems to be to sit around and study it some more," Garbett said. "BLM needs to improve its behavior. It can't be business as usual anymore. Business as usual has produced some of the worst air quality in the nation."
Streater writes from Colorado Springs, Colo.