From the Associated Press:
PAVILLION, Wyo.: After more than a year of testing, a Wyoming state study found no air quality problems near Pavillion's natural gas field.
The Casper Star-Tribune reported Friday that the Department of Environmental Quality used a monitoring station at two locations near the field owned by Encana Oil and Gas. It tested for nitrogen oxides, hydrocarbons, particulate matter and ozone.
The study, conducted from January 2011 to March 2012, found no contaminants exceeded standards set by the U.S. Environmental Protection Agency. Only ozone bumped up against the legal limit on one day last year.
A handful of residents questioned the findings at a meeting with agency officials late Wednesday. They asked whether the monitor's locations may have affected the readings. Officials said they considered wind direction and topography, among other factors.
"The real difficulty is there's no such thing as a perfect space," said Kirk Billings, an air quality analyst. "That's just the nature of the beast."
Colorado's Front Range, an area of intense oil and gas development, hasn't met EPA standards for ozone pollution during summer. A similar problem occurs in gas fields in western Wyoming and eastern Utah in winter, when bright sunshine, temperature inversions and snow help stimulate ozone formation.
Pavillion also is the center of a dispute over hydraulic fracturing and groundwater pollution. A preliminary EPA report in December linked the two. The study was disputed by Calgary-based Encana and state officials.
Hydraulic fracturing, or fracking, is the practice of blasting millions of gallons of water and smaller amounts of sand and chemicals down well holes to force open new fissures.
The Pavillion field has shallow gas and geology much different from other gas fields. Hydraulic fracturing occurred unusually close to home water wells, and the EPA has said that any findings in the area shouldn't be applied to fracking in general.
The U.S. Geological Survey released more groundwater data, without analysis, from Pavillion in September. A peer review of that data is planned.
Chesapeake Energy Corp,the Oklahoma-based firm is the No. 1 driller in Ohio.
Rig Count Interactive Map by Baker Hughes, an energy services company.
Shale Sheet Fracking, a Youngstown Vindicator blog.
The Ohio Environmental Council, a statewide eco-group based in Columbus.
Earthjustice, a national eco-group.
People's Oil and Gas Collaborative-Ohio, a grass-roots group in Northeast Ohio.
Concerned Citizens of Medina County, a grass-roots group.
No Frack Ohio, a Columbus-based grass-roots group.
Fracking: Gas Drilling's Environmental Threat by ProPublica, an online journalism site.
Pipeline, blog from Pittsburgh Post-Gazette on Marcellus shale drilling.
Allegheny Front, environmental public radio for Western Pennsylvania.