Pennsylvania’s Department of Environmental Protection (DEP) released its latest natural gas emissions inventory this week, which contained data for 2012. This was the second year for the annual report, and the findings showed significant decreases in overall air emissions related to Marcellus Shale development in Pennsylvania.

The inventory collected emissions data from 56 operators (8,800 natural gas wells) and 70 compressor station operators with 400 compressor stations. It also included 250 traditional gas compressor stations that were not included in the previous report.

The report shows natural gas emissions continue to decline as Pennsylvania increases development from the Marcellus Shale.

In 2011, for example, 1,751 Marcellus wells were developed in Pennsylvania,  a number that grew to 2,484 in 2012 – representing a 42 percent increase in producing wells in Pennsylvania.

The totals reported for the 2012 natural gas emissions inventory showed that some emissions went up – which DEP attributed to the increase in total infrastructure – while others went down. For example, both nitrogen oxides and sulfur dioxide (which are linked to acid rain and smog) both experienced noticeable declines between 2011 and 2012.

Overall, Pennsylvania experienced a significant reduction in cumulative air emissions, which represents “between $14 billion and $37 billion of annual public health benefit,” according to the DEP.

According to DEP Secretary, Chris Abruzzo:

“It is important to note that across-the-board emission reductions … can be attributed to the steady rise in the production and development of natural gas, the greater use of natural gas, lower allowable emissions limits, installation of control technology and the deactivation of certain sources.” (emphasis added)

The DEP also explained the bigger picture of increased development and decreasing emissions:

“Significantly, since 2008, when unconventional drilling across the state began quickly increasing, cumulative air contaminant emissions across the state have continued to decline. In particular, sulfur dioxide emissions from electric generating units (EGU) have been reduced by approximately 73 percent. The emissions of nitrogen oxides and particulate matter have also been reduced by approximately 23 percent and 46 percent, respectively, from this sector.”

Those reductions should continue to increase with new regulations DEP put in place in 2013, more natural gas fired power plants coming online in places like Bradford and Lycoming Counties, and as technologies and best management practices continue to improve across the industry.

When the 2013 data are released next year, hopefully we’ll continue to see the same trend we have with the impact fees: the growth of the natural gas industry is helping to improve our communities, both in terms of environmental quality and economic growth.