The Pennsylvania Department of Environmental Protection (DEP) is asking natural gas companies to provide information about air emissions from their facilities in the state.

"The use of natural gas for fuel will have very beneficial impacts on air quality, and we want to ensure we are protecting the quality of Pennsylvania's air as we access and bring to market this abundant, domestic fuel source," DEP Secretary Mike Krancer said.

The DEP asked 99 companies involved in the development, production, transmission and processing of natural gas to catalog their 2011 emissions by March 1. The request seeks information about carbon monoxide, nitrogen oxide, certain particulate matter, sulfur dioxide, volatile organic compounds and total hazardous air pollutants.

The DEP said it submits an emissions inventory to the U.S. Environmental Protection Agency (EPA) every three years, with the next scheduled for the end of 2012. As usual, the inventory will include point sources such as refineries, area sources such as gasoline stations, mobile sources such as cars and natural sources such as certain trees, but this will be the first inventory to include Marcellus Shale production and processing.

While water quality dominated the environmental concerns over shale development in Pennsylvania during 2010 and 2011, air quality is growing in stature as a point of debate. The EPA is questioning a DEP policy that could make it harder to group interconnected facilities together for the purpose of measuring emissions (see Shale Daily, Dec. 7).

The DEP, though, is touting three regional reports over the past year that found no public health risk from emissions near natural gas operations (see Shale Daily, May 24). Public health critics have challenged the short-term sampling method of those reports, and so the DEP plans to conduct a long-term monitoring effort next year.