National Port Strategy Assessment: Reducing Air Pollution in U.S. Ports



Ports are a vital part of the United States economy, with seaports, Great Lakes ports, and inland river ports serving as gateways for moving freight and passengers across the country and around the world. As our nation adapts to meet economic and infrastructure demands, it is critical to understand the potential impacts on air pollution, greenhouse gases (GHGs), and the people living, working, and recreating near ports. Diesel engines are the modern-day workhorse of the American economy, and although they can be reliable and efficient, older diesel engines can emit significant amounts of air pollution, including fine particulate matter (PM2.5), nitrogen oxides (NOx), air toxics, and carbon dioxide (CO2), which impact human health and the planet. EPA developed this national scale assessment to:

national port strategy assessment report cover photo

PDF (180 pp, 3 MB, September 2016, EPA-420-R-16-011)

  • Examine current and future emissions from a variety of diesel sources operating in port areas;
  • Explore a range of available strategies to reduce emissions from port-related trucks, locomotives, cargo handling equipment, harbor craft, and ocean-going vessels; and
  • Provide an assessment tool for  state and local governments, ports and port operators, Tribes, communities, and other stakeholders to:
    • Inform their priorities and decisions for port areas; and
    • Achieve more emission reductions across the United States.

View the report and supporting documentation:

Key Findings

Port-related diesel emissions impact public health and the climate.

EPA estimates that millions of people in the United States currently live in close proximity to ports.  These people can be exposed to air pollution associated with emissions from diesel engines at ports including particulate matter, nitrogen oxides, ozone, and air toxics, which can contribute to significant health problems—including premature mortality, increased hospital admissions for heart and lung disease, increased cancer risk, and increased respiratory symptoms – especially for children, the elderly, outdoor workers, and other sensitive populations.  Port-related diesel emissions—such as CO2 and black carbon—also contribute to climate change.  Research literature increasingly documents the effects that climate change is having and will increasingly have on air and water quality, weather patterns, sea levels, human health, ecosystems, agricultural crop yield, and critical infrastructure. 

Progress is already happening, but more emission reductions are possible.

EPA’s technology standards and fuel sulfur limits are expected to significantly reduce emissions as diesel trucks, locomotives, cargo handling equipment (CHE), and ships enter the in-use fleet. For example, the North American and U.S. Caribbean Sea Emissions Control Areas require lower sulfur fuel to be used for large ocean-going vessels (OGVs). This has reduced fuel-based PM emissions by about 90%.  Some stakeholders have also adopted voluntary strategies like those examined in the assessment. EPA supports these efforts and encourages them to continue in the future. 

We can reduce emissions with effective strategies that are currently available.

This assessment examined a suite of currently available strategies, including zero emissions (e.g., electric) technologies that can be used to develop voluntary programs to achieve additional emission reductions. The categories of strategies include replacing older diesel fleets; operational improvements to reduce idling; and switching to cleaner fuels. 

Replace older, dirtier diesel vehicles and equipment first.

Older trucks and equipment are longstanding fixtures of many port operations, and it will take many years before these fleets turn over to newer technology. Accelerating the retirement of older port vehicles and equipment and replacing them with the cleanest technology will reduce emissions and increase public health benefits beyond what would be achieved without further voluntary actions. For example, the emission reductions from replacing older drayage trucks with cleaner diesel trucks is significant, with NOx emissions being reduced by up to 48% in 2020 and PM2.5 emissions being reduced by up to 62% as compared to the Business as Usual case.

CO2 continues to increase, but effective strategies are available.

Port-related CO2 emissions are projected to increase from current levels for all mobile sources in all future years, in large part due to significant increases in economic trade and activity. This assessment evaluated voluntary replacements of diesel vehicles and equipment with zero emissions and other advanced technologies that are currently in use or in development for most port sectors.  Several strategies reduced the magnitude of increasing CO2 levels. For example, the potential for replacing older cargo handling equipment with electric technologies is significant, with CO2 emissions being reduced in 2030 by up to 18% and in 2050 by up to 45% as compared to the Business as Usual case. 

Reduction potential varies across mobile source sectors.

The voluntary strategies examined in this assessment do not achieve the same level of reductions across all mobile source sectors and pollutants.  Specifically, strategy scenarios that target land-side operations—drayage trucks, locomotives, and cargo handling equipment—are generally expected to result in greater emission reductions than those targeting water-side operations (i.e., harbor craft and OGVs). In contrast, the scenarios for harbor craft and OGV sectors produced lower, but still significant, reductions from these respective 2020 and 2030 business-as-usual emission levels. In practice, the most effective emission reduction strategies for any mobile source sector would be those that are tailored to the specific circumstances of a given port area.

Effective strategies are available for every type and size of port.

EPA conducted a stratification analysis to further understand the assessment results, since U.S. ports vary in size, purpose, mix of vessels, and ground transportation. This analysis assessed the effectiveness of strategies for ports of different types: container, bulk, and passenger; and sizes: large and small. This analysis shows that not all strategies can be expected to have the same results at all ports. Stakeholders should consider what combination of strategies should be used to reduce emissions for a particular port area, depending upon the type of activity at a given port.

More focus is needed to reduce port-related emissions.

State and local governments, ports and port operators, Tribes, communities, and other stakeholders can use this assessment as a tool to inform priorities and decisions about their port area. EPA’s assessment illustrates how more investment in reducing port-related emissions through voluntary, place-based programs can make a difference. This is important to consider in future planning, with significant investment in port-related infrastructure. In addition, many of the strategies in this assessment are also eligible for existing federal funding sources, such as EPA’s Diesel Emissions Reduction Act (DERA) grant program.