Garfield air quality improving
Stricter controls on gas drilling may be working
Garfield County last year continued to record no violations of national air quality standards.
Three monitoring sites in the county also have recorded overall five-year declines in volatile organic compounds from oil and gas development and other sources, although 2013 results bucked that trend. Officials say stricter controls on oil and gas pollution have contributed to the overall drop.
A consultant presented preliminary 2013 data and reviewed longer-term trends for Garfield County commissioners Monday.
The county has permanent monitoring sites in Parachute, Rifle, south of Silt, and most recently in Carbondale, and has a mobile site that has been stationed in Battlement Mesa for two years.
Data collected through 2013 has revealed no violations of national ambient air quality standards in the county, according to a presentation by Cassie Archuleta, a scientist with Air Resource Specialists, Inc., based in Fort Collins. That goes for three pollutants — ground-level ozone, particulate matter and nitrogen dioxide — that are measured by the county and that the Environmental Protection Agency considers “criteria pollutants” subject to the national standards.
Volatile organic compound levels had fallen every year since 2008 before increasing last year in the county, but only to levels topping those in 2012. One VOC of particular concern, benzene, had shown declines since 2009 for the three sites measuring it since 2008 — Parachute, Rifle and the Silt-area site — before jumping last year.
Archuleta said there are no national standards for VOCs, although the EPA defines risk levels for some of them. She said the last and only risk assessment conducted for Garfield County on VOCs was in 2008, when a lot of them showed the highest levels on record for the county, but even then they weren’t above those risk assessment standards.
What’s known as BTEX — a suite of VOCs including benzene, toluene, ethylbenzene and xylene — can be associated with sources including oil and gas development and automobiles. The Parachute and Rifle monitoring sites near Interstate 70 showed higher benzene and overall BTEX levels last year than the rural site south of Silt.
Archuleta said variables such as meteorological conditions could help explain the one-year uptick in VOCs. It might also show that those levels are starting to stabilize, “but there was certainly a drop before the stabilization,” she said.
Propane and ethane, both components of natural gas, make up the bulk of VOCs measured in the county, and the category of VOCs that includes them dropped every year until last year’s increase. Archuleta said increased controls on oil and gas emissions presumably came into play in contributing to that overall decline.
Looking to the VOC outlook for the county going forward, “I don’t expect it to go up given all the controls in place right now,” she said.
The county cited declining pollution levels earlier this year in arguing unsuccessfully against the Air Quality Control Commission adopting blanket new statewide restrictions on oil and gas development when the biggest concern centered on Front Range air pollution. It pointed to previously implemented state limits on oil and gas emissions, including some specifically targeting VOC emissions in Garfield, Mesa and Rio Blanco counties and adopted by the Colorado Oil and Gas Conservation Commission in 2008. These apply to condensate tanks and glycol dehydration units.
Drilling in Garfield County peaked in 2008 and generally has been on the decline since then. But Kirby Wynn, oil and gas liaison for the county, said he’s been told by Gordon Pierce, an air pollution official with the state Air Pollution Control Division, that the emissions decrease likely had more to do with emissions controls targeting production than on decreased drilling and hydraulic fracturing. Even with the drilling slowdown the county’s gas production increased as its overall active well count topped 10,000.
Pierce couldn’t be reached for comment Monday.
Jeremy Nichols, who focuses on air pollution issues for the WildEarth Guardians conservation group, said it does appear increased regulations on emissions from production are having a positive effect in the county.
“The fact is that things do seem to be getting better and they do seem to be on the right track,” he said. “… I say kudos to Garfield County. Let’s keep it up. Let’s stay vigilant.”
He said he thinks the rules adopted by the Air Quality Control Commission promise to do even more to control emissions. Meanwhile, he thinks there need to be more monitoring stations put in place in areas of oil and gas development, noting that the placement of a monitor in Rangely ended up revealing an ozone problem there.
Nichols also said that just because Garfield County’s ozone levels aren’t in violation doesn’t necessarily mean they’re healthy, and he pointed to the possibility that the EPA may further tighten its ozone standard.