The Wyoming Department of Environmental Quality (DEQ) has found no air quality issues near the Pavillion gas field where the U.S. Environmental Protection Agency (EPA) linked groundwater contamination to hydraulic fracturing. According to the agency, a review of air quality data collected between January 27, 2011, and March 31, 2012, from a mobile air-monitoring station downwind of the oil and gas development near the town of Pavillion, showed no exceedances of EPA’s national ambient air quality standards (NAAQS). During the 14-month period, DEQ’s monitoring station collected on a continuous basis: ozone, oxides of nitrogen, methane and non-methane hydrocarbons, PM10, PM2.5, wind speed, wind direction, rainfall, solar radiation, and relative humidity. The data obtained demonstrated to DEQ’s satisfaction that the area was in compliance with both EPA’s NAAQS and Wyoming ambient air quality standards. No violation of either standard was detected, and DEQ recommended no further air monitoring in the area.