On September 22, 2016, EPA issued a report titled “National Port Strategy Assessment: Reducing Air Pollution and Greenhouse Gases at U.S. Ports” (the “Assessment”).[1] According to EPA, the Assessment supports the goal of EPA’s “Ports Initiative”[2] to reduce air pollution and greenhouse gases through collaboration among industry, government, and communities. Notably, EPA urges state and local governments, ports and port operators, Tribes, communities and other stakeholders to use the Assessment to inform their priorities and port-related decision making, and to achieve more emission reductions across the United States.

Industry stakeholders should closely monitor developments that come on the heels of the Assessment. It bears watching, for example, whether state and local governments will take action – and what kind of action (voluntary measures, or command and control regulations) – to reduce port-related emissions.

Key Findings

Recognizing the vital role ports play in the United States economy – and that ports are set to expand significantly to meet economic and infrastructure demands going forward – EPA developed this national scale assessment to examine current and future emissions from various diesel sources operating in port areas and to consider potential strategies to reduce emissions from port-related trucks, locomotives, cargo handling equipment, harbor craft, and ocean-going vessels.

Key findings in the Assessment include:

  • Port-related diesel emissions, especially PM2.5, NOx and air toxics, impact public health. Port related diesel emissions, such as CO2 and black carbon, also contribute to climate change.
    • The Assessment provides “options to inform voluntary, place-based actions that may be taken by federal, state, and local governments, Tribes, ports, communities, and other stakeholders to reduce these impacts and enhance public health and the environmental protection.”
  • 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 new diesel trucks, locomotives, cargo handling equipment and ships enter the fleet, and some stakeholders have also adopted voluntary strategies to reduce emissions such as those advocated in the Assessment. EPA hopes the Assessment “will encourage more areas to adopt and incentivize such voluntary programs.”
  • Emissions can be reduced with effective strategies that are currently available.
    • EPA claims that currently available strategies, including electrification, can be used to reduce emissions. The Assessment provides the following table of such strategies:

Table 1-1. Examples of Strategy Scenarios Assessed


Scenario Description

Drayage Trucks

Replace older diesel trucks with trucks that meet cleaner EPA standards and plug-in hybrid electric vehicles.


Replace older line-haul locomotive engines with cleaner technologies, including electric locomotives.

Improve fuel economy.

Replace older switcher locomotive engines with cleaner technologies and Generator Set (GenSet) technology.

Cargo Handling Equipment

Replace older yard truck, crane, and container handling equipment with cleaner technologies, including electric technologies.

Harbor Craft

Replace or repower older tugs and ferries with cleaner technologies, including hybrid electric vessels.

Ocean-going Vessels

Switch to lower sulfur fuel levels that are below EPA’s regulatory standards, and liquified natural gas for certain vessel types.

Utilize shore power to reduce hoteling of container, passenger, and reefer vessels.

Apply Advanced Marine Emission Control Systems for container and tanker vessels.

  • Older, dirtier diesel vehicle equipment should be replaced first.
    • EPA claims that because it will be many years before older trucks and equipment turn over to newer technology, accelerating the replacement of such older vehicles and replacing them with cleaner technology is a good option, yielding benefits as set forth in the following table:

Table 1-2. Examples of Effective Port Strategies to Reduce NOx and PM2.5 Emissions

Strategy Scenario Percent reduction from BAU [Business as Usual]
NOx PM2.5
2020 2030 2020 2030

Replace older drayage trucks





Replace older switcher locomotives





Replace older CHE





Replace or repower harbor craft





Reduce OGV hoteling emissions with shore power [footnote omitted]





  • CO2 continues to increase, but effective strategies are available.
    • EPA claims that port-related CO2 emissions will increase due to increases in economic trade, but that most of EPA’s existing regulations do not address CO2 for port mobile sources. The Assessment evaluates voluntary replacement of diesel vehicles with zero emissions and other advanced technologies, concluding as follows:

Table 1-3. Examples of Effective Port Strategies to Reduce CO2 Emissions

Strategy Scenario

Percent reduction from CO2 BAU



Replace older drayage trucks with plug-in hybrid electric trucks



Replace older locomotives with electric locomotives, GenSets, and fuel efficiency



Replace older CHE with electric technologies



Reduce OGV hoteling emissions with shore power [footnote omitted]



  • Reduction potential varies across mobile source sectors.
    • The Assessment concludes that that scenarios targeting land-side operations (e.g., drayage trucks, locomotives, and cargo handling equipment) are generally expected to result in greater emission reductions than those scenarios targeting water-side operations (e.g., harbor craft and ocean-going vessels).
  • Effective strategies are available for every type and size port.
    • EPA conducted a stratification analysis assessing the effectiveness of different strategies for ports of different types: container, bulk, and passenger; and sizes: large and small. The analysis shows that not all strategies will have the same results at all ports. Therefore, the Assessment concludes that 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 port.”
  • More focus is needed to reduce port-related emissions.
    • EPA states that its assessment shows how more investment in reducing port-related emissions via voluntary place-based programs can make a difference and that many of the strategies discussed in the Assessment are eligible for existing federal funding sources, such as EPA’s Diesel Emissions Reduction Act grant program.

After the National Port Strategy Assessment: What’s Next?

EPA already supports voluntary efforts to reduce diesel emissions through its Clean Diesel Campaign and SmartWay program. It remains to be seen whether the Assessment will lead state and local governments to promote their own voluntary initiatives or mandatory regulations, and what other developments, if any, will take place as a result of EPA’s assessment.