The study, by researchers at the RAND Corporation, calculated regional damages from conventional air emissions to range between $7.2 and $32 m in 2011. Emissions included volatile organic compounds, particulate matter, sulphur dioxide and nitrogen oxides. The majority of these damages were health related – for example, respiratory problems and premature death – and while not insignificant, were small compared to those produced by the state's single largest coal-fired power plant in 2008, estimated to cost $75 m.

The RAND analysis looked only at the effects of air pollution. It did not include greenhouse-gas emissions, nor did it consider the substitution effects that might lead to decreases in air pollution if, for example, natural gas were to be used in lieu of coal to produce electricity in the region.

While the study found that emissions from shale-gas extraction make up a small fraction of the Pennsylvania total, these damages appear to be concentrated in counties where most shale-gas extraction takes place. In those locations, the net emissions increase may be equivalent to a major new source of pollution, even though individual facilities are likely to be regulated as minor sources.

On the same day that RAND's ERL paper was published, the Pennsylvania Department of Environment Protection (PA DEP) issued a proposal for new emissions permitting standards for compressor stations – facilities that prepare the natural gas to go into pipelines. This is significant since, according to the RAND analysis, 60–75% of the estimated damages come from compressor-station activities, which will continue to emit pollution for years to come.

Additionally, on 12 February 2013, PA DEP released its own statewide inventory of emissions from unconventional shale-gas extraction operations, estimates that were not available at the time the RAND analysis was completed. Public comments are now being accepted on the new permit standards, and PA DEP discussed both the new standard and the inventory in an open-to-all webinar on 21 February 2013.

Related links