Shale Gas Impoundment Ambient Air Monitoring




Allegheny County, PA

CEC Services

  • Ambient Air Monitoring

CEC Approach

CEC conducted a year-long study to characterize ambient concentrations of volatile organic compounds (VOCs) in the immediate vicinity of a shale gas surface impoundment. The study involved weekly upwind and downwind Summa® canister sample collection and analysis using EPA method TO-15. Upwind and downwind sampling locations were positioned at pairs of predetermined locations based on wind forecasts prepared by CEC. Collocated pairs of samples were collected intermittently throughout the program for quality assurance. Time-integrated 24-hour samples were collected in accordance with a CEC-authored Quality Assurance Project Plan. CEC also collecting impoundment fluid samples for laboratory analysis coincident with the atmospheric sampling.

Once the year-long study was completed the data was statistically analyzed in an attempt to determine if there was a statistical increase of VOCs immediately downwind of the impoundment compared to upwind. Only data that was determined to be valid as specified in in the quality assurance plan were used in this statistical analysis. Based on the analysis of the valid data, it does not appear that there was a significant increase in VOCs downwind of the impoundment versus upwind.