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Press Release

MPLX LP to Cut Harmful Air Pollution at Natural Gas Processing Facilities Improving Air Quality for Communities in Six States

For Immediate Release
Office of Public Affairs

Today, the U.S. Department of Justice, the U.S. Environmental Protection Agency (EPA), the State of Oklahoma, the Pennsylvania Department of Environmental Protection, and the State of West Virginia announced a settlement agreement with MPLX LP (MPLX) and 11 of its subsidiaries that will strengthen air pollution controls at 20 natural gas processing plants located in Pennsylvania, Ohio, West Virginia, Kentucky, Texas and Oklahoma.

The settlement addresses alleged violations of federal and state clean air laws governing the control of emissions from equipment leaks, pressure relief devices, storage tanks, truck and railcar loading, combustion devices, and process heaters. As part of the settlement, MPLX will also perform Supplemental Environmental Projects (SEPs), install equipment to control volatile organic compound (VOC) emissions from truck loading operations at two natural gas compressor stations, and pay a $925,000 penalty.

“This agreement will eliminate harmful air pollutants and create cleaner air for communities in six states,” said EPA Office of Enforcement and Compliance Assurance Assistant Administrator Susan Bodine.  “By improving air pollution control at 20 of their gas processing facilities, MPLX will reduce VOC emissions by more than 1,500 tons a year.”

Under the terms of the settlement, MPLX is expected to spend approximately $2.78 million to install and operate new technologies as well as improve and expand existing control techniques that minimize VOC emissions at its natural gas processing plants. Certain provisions of the consent decree also include measures to ensure MPLX’s compliance with nitrogen oxide (NOx) emission limits applicable to process heaters at MPLX’s facilities. In addition, MPLX will implement a mitigation project to reduce VOC emissions at two natural gas compressor stations in Pennsylvania and Ohio, respectively, through the installation of new technology to capture and control VOC emissions during truck loading operations, which is expected to cost at least $700,000. MPLX will also implement SEPs involving the installation and operation of ambient air monitoring stations adjacent to four natural gas processing plants located in Pennsylvania, West Virginia, Kentucky, and Texas, respectively, at a cost of $2.5 million. Finally, MPLX will implement a SEP involving the study of the effectiveness of computer predictive modeling of fugitive leaks as a potential emission reduction tool, at a cost of $75,000. 

VOCs include a variety of chemicals that may produce adverse health effects such as eye, nose, and throat irritation, headaches, nausea, and damage to the liver, kidney, and the central nervous system. VOCs also contribute to the formation of ground level ozone, which is not emitted directly into the air, but is created by chemical reactions between NOx and VOCs in the presence of sunlight. Breathing ozone can trigger a variety of health problems, particularly for children, the elderly, and anyone with lung diseases such as asthma. Ground level ozone can also have harmful effects on sensitive vegetation and ecosystems. Besides ground level ozone, NOx emissions also contribute to acid rain, particulate matter, water quality deterioration, and visual impairment.

The consent decree has been lodged with the U.S. District Court for the Northern District of Ohio and is subject to public comment for a period of at least 30 days. Notice of the lodging of the consent decree will appear in the Federal Register allowing for a 30-day public comment period before the consent decree can be entered by the court as final judgment. The consent decree will be available for viewing at

For more information on the settlement, please visit:

Updated April 5, 2024

Press Release Number: 18-1440