Emissions of methane and volatile organic compounds increased from 2014 to 2015 during operations associated with natural-gas industry hydraulic fracturing, but other pollutants decreased, according to new data from the Pennsylvania Department of Environmental Protection.
Emissions that fell included nitrogen oxide, sulfur dioxide, and particulate matter, according to the figures released Thursday.
The data, the latest available, are reported by the industry as required under Pennsylvania’s Air Pollution Control Act. They include 2015 emissions from production and processing, as well as compressor stations that receive gas both from conventional and unconventional well sites and coal gas.
Methane emissions were up about 4 percent, from 107,735 tons per year in 2014 to 112,128 tons in 2015. Volatile organic compounds rose 7.5 percent from 5,961 tons to 6,410.
“The inventory presents a mixed picture of emissions from the unconventional natural-gas industry” said DEP Secretary Patrick McDonnell. “Certain pollutants are decreasing as best practices are implemented more widely through the industry, while others — including methane, a potent greenhouse gas — continue to increase, underscoring the need to do more to detect and fix leaks in order to reduce emissions.”
The DEP says that production from unconventional gas wells increased from 4.1 trillion cubic feet in 2014 to 4.6 trillion cubic feet in 2015. The agency also says that the reason methane may be up by about 4 percent is because there is more production.
But the average methane emission per facility has stayed level, it said. The average methane reported from compressor stations dropped.
David Spigelmyer, president of the Marcellus Shale Coalition, a trade association for gas producers, said the data “confirms that Pennsylvania’s natural gas operators are doing a tremendous job of limiting emissions.”
The figures released this week are lower than figures released in the spring by the nonprofit group PennFuture, which obtained emission data from the DEP through a right to know request.
Neill Shader, a spokesman with the DEP, said the earlier numbers the agency had collected “had not been reviewed for accuracy.” The more current ones have been, he said.