Air emissions from Pennsylvania's natural gas industry operations in 2014 continued to increase, mainly as more midstream facilities came online to support shale producers, according to the state Department of Environmental Protection's (DEP) latest inventory report.
But while pollutants from upstream and midstream activities were on the rise two years ago, the latest period for which data is available, emissions from the state's electric generation sector declined, thanks in part to natural gas displacing coal at some facilities.
From 2013 to 2014, nitrogen oxides from unconventional natural gas operations increased 18%; fine particulate matter was up 25%; sulfur dioxide increased 40%, and volatile organic compounds rose by 25%. But the methane emissions linked to shale production, which have been increasingly scrutinized by the state and federal governments and industry opponents, increased by just 1%. Emissions increases between 2012 and 2013 were somewhat similar to the latest reporting period (see Shale Daily, April 20, 2015).
"As pipeline infrastructure and natural gas production continues to grow in Pennsylvania, it is increasingly important that we ensure that natural gas stays in those pipelines and other facilities and isn't leaking into our communities," DEP Acting Secretary Patrick McDonnell said. "With universal adoption of best practices that many companies are already using, we expect leaks to go down even as production goes up."
The air inventory includes emissions from Marcellus Shale gas production and processing operations, as well as compressor stations that receive gas from coalbed methane and conventional and unconventional sites. The industry must report emissions to the DEP under the state's Air Pollution Control Act. DEP started collecting the data from unconventional sources in 2011, but later expanded those requirements to include midstream operations involving coalbed methane sources and legacy producers. Reporting sources include drilling rigs, wellheads, compressors and fugitive sources such as flanges, pumps and valves, among other things.
While natural gas industry emissions increased, the DEP noted that they represent "only a fraction" of all emissions produced by various industries across the state. Between 2011 and 2014, the DEP said, nitrogen oxides and sulfur dioxide emissions -- which contribute to acid rain and exacerbate asthma -- from electric generating units declined by 18% and 17%, respectively. Marcellus Shale Coalition President David Spigelmyer attributed that drop to "the continued safe production" of "clean-burning natural gas," saying producers remain focused on working with regulators and stakeholders to keep contributing to those declines.
"Pennsylvania must continue to expand its natural gas infrastructure network so more families, manufacturers and power generators have access to abundant, affordable and clean burning natural gas," he said.
Unconventional gas production has increased significantly since the state started collecting emissions data in 2011. At that time, shale drillers produced 1.1 Tcf. By 2014, those volumes had increased to 4.1 Tcf. They went up again last year to 4.6 Tcf.
While the number of well sites reporting dropped by 2.7% between 2013 and 2014, going from 10,275 to 10,009, the number of midstream facilities that submitted data increased from 447 to 508. In 2011, 9,037 wells reported and just 150 midstream facilities submitted data.
The DEP continues to monitor emissions and has worked to tighten its regulatory standards. In January, Gov. Tom Wolf announced that the agency would work on a four-part plan to reduce methane emissions from gas wells (see Shale Daily, Jan. 19). Unconventional operators also could soon be facing tighter environmental regulations in the state as a sweeping package of new rules is close to being implemented (see Shale Daily, Aug. 15).