Emissions control in the USA

In US territorial waters, regulations on emissions from ships are managed by the Environmental Protection Agency (EPA)

The EPA manages regulations on emissions from ships in accordance with the Clean Air Act, a federal law that regulates air emissions from stationary and mobile sources. The law authorizes the EPA to establish National Ambient Air Quality Standards (NAAQS) to protect public health and regulate emissions of hazardous air pollutants but does not yet include caps on GHGs.

The EPA, and other departments within the US government, work with the IMO to help draft, amend and enforce international regulations on emissions. For example, the USA successfully petitioned the IMO to designate the North American Emission Control Area (including the Hawaiian Islands) in 2010 and the U.S. Caribbean Sea Emission Control Area in 2014, both addressing SOx and NOx.

Engine certification and reporting

The EPA issues the Engine International Air Pollution Prevention (EIAPP) certificate to document that the engine meets MARPOL Annex VI NOx standards for US-flagged vessels. The U.S. Coast Guard issues International Air Pollution Prevention (IAPP) certificates and makes sure operators maintain records regarding their compliance with emission standards, fuels requirements and other provisions of MARPOL Annex VI.

GHG emissions

Several US federal agencies have joined in developing a roadmap for reducing emissions from the transport sector, including maritime, which was released in January 2023. The roadmap for maritime outlines actions on research and innovation, international and domestic stakeholder engagement, as well as infrastructure investment and improved design and planning. The USA is unlikely to impose additional GHG requirements on international ships sailing to US ports or in US waters in the near term (as of April 2023).

Port authorities

Port emissions are managed by local authorities, with policies that vary from state to state. For example, in 2020, the Port of Houston became the first in the world to power all terminals and public facilities with renewable electricity from a solar farm in west Texas. And in 2021, California’s State Office of Administrative Law tightened emissions regulations defined by the Control Measure for Ocean-Going Vessels at Berth, which include limits on GHGs and adds shore power mandates. Many other ports in the USA offer shore power, which supplies vessels in port with electricity from existing grids.