Comment Period on Proposed Changes Open until March 19HARRISBURG, Pa., Jan. 31, 2013 /PRNewswire-USNewswire/ -- The Department of Environmental Protection announced today it has finalized revisions to a general permit for natural gas-fired engines and equipment at compressor stations, which help move gas from well sites into transmission pipelines. The revised general permit includes significantly lower allowable emission limits than the previous general permit, called GP-5. DEP also announced it will accept public comment on a proposed plan approval and operating permit exemption for air emission sources at well drilling sites. Well sites would only be eligible for the exemption for the air quality plan approval process if the wells will meet emission control and monitoring criteria that are stricter than federal air quality rules for controlling wellhead emissions. The plan approval authorizes construction of facilities that emit certain types and amounts of pollutants. " Pennsylvania has seen improved air quality over the past decade, and the United States led the world in greenhouse gas emission reductions over the past five years, in great part due to shale gas," DEP Secretary Mike Krancer said. "This shift in the way we approach emissions will help us continue these trends. "The steps we are taking now mean far lower emissions at well sites and more efficient compressor stations, resulting in cleaner air as development, production and transmission take place," he said. "DEP's effective and robust oversight will deliver on the promise of cleaner air from the increased use of natural gas." The final revisions to GP-5, which were developed after considering public comment, impose emissions limits that are 75 to 90 percent stricter than current limits for the largest, most common types of engines used at compressor stations. Notably, the revised permit also affords operators the ability to install controls to achieve even lower emissions, allowing for the use of additional engines.