We Take Pride in Our Role as Environmental Stewards

Preserving Our Surroundings

MPC owns and maintains 21 wildlife habitats with more than 1,352 acres of land. From prairies and wetlands to locations where bees are kept, each habitat is unique and part of our long-term commitment to environmental stewardship.

Energy efficiency is central to our core values, but it goes beyond environmental sustainability. It's about our company's sustainability as a whole because it strengthens the bottom line.

Energy Efficiency

Energy efficiency is one of our key metrics with both environmental and financial benefits. By identifying where energy can be conserved cost-effectively, we reduce our operating costs, save our shareholders money and reduce our environmental footprint.

We have implemented multiple programs to improve energy efficiency across our assets including a Focus on Energy program within our refining organization. Through this program, we measure energy efficiency by using the HSB Solomon Associates Energy Intensity Index (EII®). According to the most recent Solomon study, released in 2017, five of our legacy refineries were considered Top Tier, based on EII in their respective equivalent distillation capacity (EDC®) class, and three were the most efficient in their class.

As we implement the “Focus on Energy” program across the 10 additional refineries we acquired from Andeavor in October 2018, we expect our EII scores will continue to improve. Our energy-efficiency programs and associated metrics have achieved best-in-class performance with numerous U.S. Environmental Protection Agency (EPA) certifications and endorsements through the ENERGY STAR® and SmartWay® Programs, including the ENERGY STAR Partner of the Year award in 2018 and 2019. We were the only oil and gas company to receive this honor in 2018 and 2019.

View Our 2018 ENERGY STAR Video

MPC is the industry leader in recognition under the ENERGY STAR Program, having earned 72 percent of the total recognitions (42 of 58).

Flare Reduction and Efficiency

We are an industry leader in reducing emissions from refinery flares.  As part of the EPA’s refinery flare enforcement initiative, we collaborated with the EPA to define operating parameters, such as Net Heating Value in the Combustion Zone (NHVcz), that ensure flares continuously operate above 98 percent combustion efficiency.  We were the first company to produce and publish the results of our own flare performance tests, which EPA acknowledged was a unique level of cooperation that is rarely seen. Subsequently, we entered into an agreement with the EPA to reduce flaring emissions at our refineries and incorporated the newly developed operating parameters. These same parameters were used by EPA to set regulatory standards for industrial flares throughout industry.


By working with EPA, Marathon helped advance new approaches that reduce air pollution and improve efficiency at its refineries and provide the U.S. with new knowledge to bring similar improvements in air quality to other communities across the nation.

– Cynthia Giles, Former Assistant Administrator for EPA's Office of Enforcement and Compliance Assurance, April 2012


Our flare reduction strategy focuses on source reduction (preventing gases from entering the flare system), waste gas recovery and optimizing flare combustion efficiency. Fourteen of our 16 refineries have flare gas recovery systems that recover gas entering the flare system, so it can be used as fuel within the refinery instead of being burned by the flare. Recovering these gases reduces reliance on purchased natural gas, lowering overall greenhouse gas (GHG) emissions. In total, our refineries have invested more than $600 million on projects that reduce flaring, increasing the value of the gas streams we now recover to more than $30 million per year. At our legacy refineries, these improvements have resulted in a 90 percent reduction in emissions of volatile organic compounds, an 87 percent reduction in emissions of hazardous air pollutants, and a 58 percent reduction in GHG emissions from 2007 levels, the baseline year for our flare performance studies.

View Refinery Flare Emissions Reductions Chart

Greenhouse Gas Emission Reductions 

We have reduced our greenhouse gas (GHG) intensity significantly since 2002 through our energy efficiency measures and the diversification of our portfolio. For instance, our Focus on Energy program has enabled us to increase refining capacity by approximately 480,000 barrels per day, equivalent to the sixth-largest refinery in the U.S., without significantly increasing GHG emissions. In addition, our natural gas processing and fractionation facilities have lowered our company-wide GHG intensity since acquisition in late 2015. Overall, our energy efficiency efforts have avoided emitting millions of tons of GHGs per year. Learn more in our Perspectives on Climate-Related Scenarios publication.

View Greenhouse Gas Emissions Charts

Criteria Pollutant Emissions

Energy efficiency and flare reduction also aid MPC's work to reduce criteria pollutant emissions. The graphs below illustrate the success of these efforts. Just one example is at our Galveston Bay refinery, where we are replacing existing heaters with new ones equipped with state-of-the-art emissions controls. By investing in new heaters, we expect to reduce nitrogen oxide emissions by over 370 tons per year.

From 2002 to 2017, we reduced our criteria pollutant emissions per common barrel of throughput by roughly 70 percent. Such improvements in emissions intensity are not achieved without significant expense. We have invested over $700 million to achieve these dramatic results. We are also making ongoing improvements within our gathering and processing operations designed to further reduce fugitive emissions.

  View Criteria Pollutant Emissions Charts

Reducing Methane Emissions

Through MPC's master limited partnership, MPLX LP, we operate one of the largest natural gas gathering and processing networks in the country. We are continually advancing opportunities to reduce emissions of methane and other pollutants.  Some key focus areas we are actively addressing include reducing emissions from pipeline launchers and receivers, lowering fugitive emissions from equipment, and replacing pneumatic controllers.      

Read More

Pipeline Launchers and Receivers
Pipeline launchers and receivers are chambers positioned throughout our pipeline system that allow us to introduce devices, called pigs, into the pipeline.  Pipeline pigs come in many shapes, sizes and capabilities. Some are disks used to clean pipes or push liquids from low points, while others are sophisticated scanning equipment that provides pipeline inspectors with critical data to ensure integrity. Each time a launcher or receiver chamber is opened, a small amount of air within the chamber can escape to the atmosphere, and with it, the volatile organic compounds (VOCs) and methane. 

Recognizing that emissions could be reduced through the installation of additional controls, MPLX entered into a first-of-its-kind agreement with the U.S. EPA and the Commonwealth of Pennsylvania to implement innovative design and operating improvements at pipeline launcher and receiver stations. These improvements are expected reduce emissions from these operations by as much as 85 percent eliminating an estimated 700 tons per year of VOC emissions and 3,100 tons per year of methane emissions (the equivalent of more than 75,000 tons of CO2).  As part of the agreement, we are sharing our proprietary designs for “Pig Ramps” that minimize liquid loss during pig retrieval and providing information on the installation of depressure systems to reduce the pressure in the launcher/receiver chamber prior to opening. Information on the designs is available here.

A royalty-free Patent License Agreement and Release for Patent Nos. 10,001,240; 10,012,340; and 10,094,508 is available here.

Prior to installing the technology subject to the referenced patents, please complete the attached License Agreement and Release and return to: Assistant General Counsel MPLX G&P Law, 1515 Arapahoe Street, Suite 1600, Denver, CO 80202. Please send any inquiries to robert.mchale@markwest.com.

Controlling Fugitive Emission
Through a separate agreement with U.S. EPA, we are also adopting enhanced measures to reduce fugitive emissions at gas processing and fractionation facilities. These measures include lowering the detection limit we use within our leak detection and repair (LDAR) program and broadening the types of equipment we monitor. We are also adopting enhanced design standards for low-leak technology on valves and connectors. These collective measures are expected to reduce fugitive VOC emissions by more than 1,500 tons per year and methane emissions by more than 2,300 tons per year (the equivalent of nearly 60,000 tons of CO2).

We are also phasing out the use of high-bleed pneumatic controllers by replacing them with lower-emitting devices. Collectively, these innovative design modifications and commitments will continue to lower the methane and VOC emissions throughout our natural gas gathering and processing distribution system.

Waste Reduction and Recycling

We are continually working to reduce the volume of waste we generate and to find alternatives for disposal, such as reclamation and recycling. A recent example is the construction of a thermal desorption unit (TDU) at our Galveston Bay refinery. The new TDU will complement units already in operation at our Catlettsburg, Garyville and Robinson refineries. The thermal desorption process uses indirect heat to separate hydrocarbons from oily waste materials. This has three main benefits: (1) hydrocarbons are recovered and returned to the refining process as feedstock, (2) the hazardous characteristics of the waste materials are removed, and (3) the total volume of waste material is reduced. We also work with companies that specialize in metals reclamation, in lieu of using landfills, to manage many of the spent catalysts we use in our processes. These companies recover and recycle metals, such as cobalt, copper, molybdenum, platinum and vanadium. This reduces the overall volume of material to be landfilled and provides a beneficial use for these materials.