Managing impacts on air and water

Report Dec. 20, 2019

In this article

Managing impacts on air and water

Air emissions 


Our efforts to reduce air emissions are supported by capital investments, integration of cost-effective technologies and innovative operating practices. In some cases, new regulatory requirements drive emissions reductions. We track emissions of various pollutants, including volatile organic compounds, sulfur dioxide and nitrogen oxides, associated with our operations. 

2018 performance and initiatives

Our combined emissions of volatile organic compounds, sulfur dioxide and nitrogen oxides have decreased by 14 percent overall over the past 10 years across our businesses. For historical data on ExxonMobil’s air emissions, visit our performance data table


ExxonMobil Biomedical Sciences, Inc.

ExxonMobil Biomedical Sciences, Inc. (EMBSI) is our global organization that provides objective research and scientific advice on human health, environmental and regulatory issues associated with our products, operations and technology development. EMBSI’s work helps identify and deliver solutions that enable ExxonMobil to protect human health and the environment while meeting future energy needs. The EMBSI team includes toxicologists, epidemiologists, and exposure and environmental scientists that assess human health and environmental risks. Example initiatives include organizing research collaborations with industry, government, academic and other scientists to understand and manage potential risks of oil and gas development and developing data and technical assessments to support the safe manufacture and use of petrochemical products around the world.

Freshwater management 


ExxonMobil manages water resources with care. For applicable upstream projects, our Water Management Standard requires a risk assessment that evaluates local water resources and potential mitigation actions at the project development stage. 

Based on the latest version of the IPIECA water tool, we estimate that approximately 40 percent of our major operating sites are in areas with potential water scarcity. To manage these risks, we pursue site-specific management strategies that include water conservation technologies, use of alternative water sources, recycling of municipal and industrial wastewater, and collection of rainwater.

Water consumption is primarily associated with hydraulic fracturing in our upstream onshore operations. Hydraulic fracturing is the process of using water pressure to create small cracks or fissures in rocks deep underground so oil or natural gas can flow to the well. Water use differs by basin due to geological and reservoir characteristics, as well as optimization of drilling and completion designs. The industry has more than 60 years of experience in hydraulic fracturing, and we continually seek opportunities for improvements. 

2018 performance and initiatives

In 2018, the net freshwater consumption at our operations totaled 310 million cubic meters, an increase of about 7 percent from the 2017 consumption of 290 million cubic meters and about a 9 percent decline since 2009. ExxonMobil’s total freshwater consumption includes global use by refineries, chemical plants, and oil and gas production, as well as onshore shale resource development in the United States.

Global freshwater consumption*

Millions of cubic meters
ExxonMobil's global freshwater consumption in 2018 was 310 million cubic meters. This represents a 20 million cubic meter increase compared to our 2017 global freshwater consumption.

*We report freshwater intensity alongside consumption data in our performance data. Data includes XTO Energy data beginning in 2011.

Wastewater management 


Oil and natural gas production, refining and chemical operations generate wastewater that requires treatment before discharge or disposal. Treatment methodologies range from removal of suspended hydrocarbons and solids from produced water to biological treatment systems for refinery wastewater. Produced water, a byproduct of oil and gas production operations, is typically managed onshore by injection into deep underground reservoirs. For offshore production facilities, ExxonMobil reinjects produced water into an associated reservoir when feasible, or we treat and discharge it into the marine environment in accordance with applicable regulatory requirements.

Our Water Management Standard outlines the environmental performance expectations of our upstream projects. The Standard establishes the planning-and-design basis for reducing potential impacts to surface, ground, estuarine and marine water. For the downstream business, the Standard helps meet discharge requirements when a country has no standards or less-stringent standards than our own specifications. We work to design facilities in a manner that controls the quality of discharged water. 

2018 performance and initiatives 

In 2018, ExxonMobil’s Billings, Montana, refinery supported the removal of up to 3 million gallons a day of permitted wastewater from the Yellowstone River by rerouting the wastewater to the City of Billings municipal wastewater treatment plant for advanced treatment of nitrogen and phosphorus. An excess of these nutrients can lead to a surplus of algae and deplete oxygen levels, which can impact local aquatic populations. Excess nutrients can also limit recreational activities such as fishing and boating. Rather than requiring all companies that discharge wastewater to build their own advanced treatment facility, ExxonMobil shares the cost of nutrient removal with other responsible parties in the city. In doing so, we can meet applicable permit requirements while maintaining operational flexibility. 

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Sustainability Report Dec. 20, 2019


ExxonMobil’s diverse portfolio of projects requires us to work in remote and sensitive environments, including deepwater and biodiverse locations. Our environmental management approach is guided by an understanding of the potential environmental impacts of our operations and a commitment to sustainably develop, maintain and operate projects using appropriate standards that enable us to ‘Protect Tomorrow. Today.’

Sustainability Report