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MPLX LP Clean Air Act Settlement Information Sheet

(Washington, DC - November 1, 2018) - The U.S. Environmental Protection Agency (EPA), U.S. Department of Justice (DOJ), 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. 

Overview of Company

MPLX LP is a master limited partnership formed by Marathon Petroleum Corporation to own and operate midstream energy infrastructure assets. Of relevance to this settlement, MPLX’s assets include multiple natural gas processing plants that extract natural gas liquid products such as ethane, propane, butane, isobutane, and natural gasoline.   

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The United States, the State of Oklahoma, the Pennsylvania Department of Environmental Protection and the State of West Virginia have filed a complaint against MPLX and 11 of its subsidiaries (MPLX) for violations of the Clean Air Act and analogous state air pollution control laws at MPLX natural gas processing plants in Pennsylvania, Ohio, West Virginia, Kentucky, Texas, and Oklahoma.  

MPLX failed to comply with multiple volatile organic compound (VOC) emission control requirements under several New Source Performance Standards (NSPS) applicable to natural gas processing plants, including failure to comply with Leak Detection and Repair (LDAR) requirements, failure to control VOC emissions from pressure relief devices, and failure to comply with enclosed combustor testing and monitoring requirements. MPLX also failed to comply with the NSPS for synthetic organic chemical manufacturing distillation units and NSPS regulations applicable to MPLX’s hot oil process heaters .    

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Injunctive Relief

MPLX has agreed to the following elements of injunctive relief for 20 natural gas processing plants: (1) comply with NSPS Subpart OOOO at process units currently subject to the less stringent NSPS Subpart KKK (which includes implementation of connector monitoring at such units); (2) implement an LDAR Program that will bring facilities into compliance with LDAR regulations, and which includes measures to mitigate the environmental harm caused by alleged noncompliance; (3) install technological fixes for pilot-operated pressure relief valves to prevent pilot-escaping emissions from being vented directly to the atmosphere; (4) comply with NSPS Subpart NNN applicable to synthetic organic chemical manufacturing distillation units; (5) implement fugitive leak monitoring for fin fan heat exchangers using optical gas imaging (OGI) instrumentation; (6) monitor and maintain minimum combustion operating temperatures for enclosed combustors; (7) improve LDAR monitoring at hose connections at railcar/truck loading operations; (8) improve LDAR monitoring associated with pressure relief devices at natural gasoline tanks and install isolation valves on such devices to facilitate repair of the devices without need to wait for process shutdowns; (9) implement NOx emission monitoring measures to comply with NSPS Db and Dc requirements applicable to process heaters at MPLX facilities; and (9) submission of applications for non-Title V permit amendments to incorporate consent decree requirements that will survive termination of the Consent Decree.  

Also, to mitigate the environmental harm caused by its alleged noncompliance, MPLX has agreed to reduce VOC emissions at two of its natural gas compressor stations (one in Pennsylvania and one in Ohio) by installing at those stations VOC emission capture technology applicable to truck loading operations.

The injunctive relief under this settlement is valued at approximately $3.483 million.

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Pollutant Impacts

When fully implemented, EPA estimates that the new controls and requirements would result in emission reductions of 1,523 tons per year of VOCs from MPLX’s natural gas processing plants.

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Health Effects and Environmental Benefits

VOCs contribute to smog and to sensory irritation symptoms, allergies and asthma, and neurological and liver toxicity. Certain VOC are also known carcinogens. NOx emissions contribute to smog as well as acid rain, particulate matter, water quality deterioration, and visual impairment. Through the implementation of injunctive relief at 20 natural gas processing plants, MPLX will improve air quality in Pennsylvania, Ohio, West Virginia, Kentucky, Texas, and Oklahoma.  

As a condition of settlement, MPLX has agreed to install and operate ambient air VOC monitoring  stations near four natural gas processing plants in Pennsylvania, West Virginia, Kentucky, and Texas that will cost at least $2.5 million. Information gathered about the nature and extent of VOC emissions from natural gas processing plants will be shared with the public. In addition, MPLX will conduct a predictive fugitive leak monitoring study to test the efficacy of predictive computer modeling for fugitive leaks at a natural gas processing plant in Ohio, which will cost at least $75,000. If proven successful, such technology may be used by industry in the future to find and repair VOC-leaking components faster and more cost-effectively.     

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Civil Penalty

The proposed decree requires Defendants to pay a $925,000 civil penalty.

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Comment Period

The proposed settlement, lodged in the U.S. District Court for the Northern District of Ohio, is subject to a 30-day public comment period and final court approval.  Information on submitting comment is available at the Department of Justice.

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For more information, contact:

Mark Palermo (Attorney-Advisor)
EPA Office of Civil Enforcement, Air Enforcement Division
U. S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW, Mailcode 2242A, Washington DC, 20016
(202) 564-8894

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