The Department of Environmental Protection Thursday announced its long-term air monitoring study in southwestern Pennsylvania will continue through the end of the year. The agency also released a technical support document that provides additional information about the study’s scope and process.

“The use of natural gas holds great promise in continuing recent trends of cleaner air in this state, and the data from this study will allow us to make sound decisions for the long-term,” DEP Acting Secretary E. Christopher Abruzzo said. “Our study, which is stationed in one of the most active drilling regions in the state, will help us to identify potential air-quality related risks associated with drilling, processing and transporting natural gas.” 

In July 2012, DEP announced it would be conducting a long-term study in southwestern Pennsylvania to measure ambient air concentrations of pollutants, in Chartiers Township, Washington County, where both “wet” and “dry” gas are being extracted and moved to sale via compressor stations and pipeline networks.

The Technical Support Document gives the public additional detailed information on the study, its sampling design and the analysis methods critical to the success of the study. The document also provides more detail about the science behind ambient air studies.

The samples collected during the study will be subjected to rigorous quality-assurance and data validation criteria. A final report is expected to be released in the spring of 2014.

DEP previously conducted three short-term ambient air quality sampling studies in various drilling regions of the state, detecting no levels of any pollutant that would violate federal ambient air quality standards. Nor did the studies identify concentrations of any compound associated with Marcellus shale drilling activities that would likely trigger air-related health issues.

The main monitoring site for the long-term study includes sampling for ground-level ozone, particulate matter, carbon monoxide, nitrogen oxides, hydrogen sulfide and methane. The ambient air will also be tested for more than 60 volatile organic compounds, including hazardous air pollutants, and meteorological data will be collected continuously.

DEP is also monitoring for volatile organic compounds and collecting meteorological data at three additional sites in Chartiers Township and Hickory Township, Washington County. Of the two additional Chartiers Township sites, one is upwind of the Houston gas processing plant, and the other is downwind of the Brigich compressor station. The site in Hickory Township will be located downwind of the Stewart compressor stations.

The long-term study is the latest effort by this administration to ensure that the abundant natural gas resources are being developed responsibly. Earlier this year, DEP announced a revised general permit for compressor stations and gas processing facilities that included significantly lower allowable emission limits.

A recent DEP emissions inventory submitted to EPA in December 2012, showed significant reductions in sulfur dioxide emissions in Pennsylvania between 2008 and 2011. These reductions, which are due to the deactivation of certain sources, installation of emissions controls at other remaining sources, and the conversion to natural gas have represented between $14 and $37 billion of annual public health benefit, based on EPA methodologies.

The inventory, which for the first time included unconventional gas operations, also showed significant reductions in nitrogen oxide, carbon monoxide, volatile organic compounds and particulate matter during that same time period.

For more information, visit DEP’s Air Quality webpage or call 717-787-9702.  DEP’s Sampling Protocol is also available.

8/5/2013