HARRISBURG, Pa. — Emissions from drilling represent a small fraction of air pollution in Pennsylvania, and levels have gone down considerably since shale gas development began in earnest several years ago, according to a new report from the Pa. Department of Environmental Protection.

The department released emissions data for the unconventional drilling industry that represents 2011 emissions from natural gas production and processing facilities, such as wells and compressor stations.

“We have the regulations in place to assure that air emissions during drilling and transmission do not compromise the environmental benefit of natural gas,” said DEP Secretary Mike Krancer.

Self-reported data

For the inventory, 57 operators of unconventional wells and 40 mid-stream operators of 150 compressor stations reported data.

While unconventional gas production and processing emitted 16,542 tons of nitrogen oxides in 2011, emissions of the same pollutant have fallen 43,000 tons per year.

“It is worth noting that annual sulfur dioxide emissions are down more than half a million tons per year from where they were in 2008,” Krancer said. “This is a direct result of air quality regulations and the increased use of natural gas in the power generation sector.”

Emissions of fine particulate matter and volatile organic compounds are also down, both within the power generation sector and across the state.

Surveyed every three years. DEP must submit a comprehensive air emissions inventory to the U.S. Environmental Protection Agency every three years. The inventory includes emissions data from sources such as refineries, manufacturing plants, power plants, dry cleaners and cars, trucks and other vehicles.

DEP collects emissions inventory data from the point sources annually, and Act 13 of 2012 requires the owners or operators of the unconventional natural gas sources to submit an annual emissions inventory to DEP by March 1 of each year.

DEP recently announced, for the next inventory submission due March 1, 2013, that conventional oil and gas compressor stations must report emissions data for 2012.
In 2010, DEP conducted short-term air quality monitoring studies in the southwest, northeast and north-central regions of the state.

The studies did not identify concentrations of any compound that would likely trigger air-related health issues associated with Marcellus Shale drilling activity, nor did DEP detect concentrations above federal ambient air quality standards for carbon monoxide, nitrogen dioxide, sulfur dioxide and ozone at any of the sampling sites.

Washington County

DEP is in the midst of a year-long air monitoring study in Washington County in the southwest region of the state to determine potential air quality impacts associated with the processing and transmission of unconventional natural gas. The data from the study will allow DEP to assess any potential long-term impact of emissions from unconventional natural gas operations to nearby communities.

Regs changed

DEP also recently announced significantly lower allowable emissions for compressor stations permitted under a general permit, called GP-5.

The agency is accepting comments on a proposed revised permit exemption for well heads and associated equipment that specifies emissions control criteria that must be met to qualify for the exemption.

For more information and to view the unconventional emissions data, visit www.dep.state.pa.us and click “Air” or call 717-783-9241.