The California Air Resources Board (CARB) intends to expand its existing Ocean-Going Vessels At-Berth Regulation (the Regulation) in order to reduce further air emissions from ships docked in California. Proposed changes include:

  1. Increasing the number of ports and facilities subject to the Regulation;
  2. Expanding the types of vessels covered by the Regulation; and
  3. Changing the threshold for when emission control requirements are triggered.


CARB first adopted the Regulation (full name: “Airborne Toxic Control Measure for Auxiliary Diesel Engines Operated on Ocean-Going Vessels At-Berth in a California Port”) in 2007 to protect public health by controlling oxides of nitrogen (NOx), and particulate matter emissions from diesel auxiliary engines on container ships, passenger ships, and refrigerated-cargo ships while berthing at major California ports. In addition, CARB adopted the Regulation to combat climate change through the reduction of carbon dioxide, a greenhouse gas.

The Regulation currently provides two options to reduce at-berth emissions:

  1. Turn off auxiliary engines and connect the vessel to some other source of power, typically shore based grid power (shore power), or
  2. Use an “alternative control technology” that achieves equivalent emission reductions.

Proposed amendment to the Regulation

The draft regulatory revisions for the new At-Berth Regulations (the New Regulation) are designed to:

  • Achieve additional emissions reductions of (i) diesel particulate matter (DPM), (ii) particulate emissions of less than 2.5 microns in diameter, (iii) nitrogen oxide (NOx), and (iv) other greenhouse gases (GHG) (as a co-benefit of increased shore power usage) beyond those realized by the existing Regulation;
  • Further reduce adverse health impacts to the communities surrounding ports and terminals; and
  • Increase the clarity and enforceability of regulatory requirements for vessels.

The draft regulatory revision would accomplish the above goals by:

1. Increasing the number of ports and facilities subject to the Regulation

Introducing emission control requirements to additional ports and marine terminal complexes (MTCs) is a key goal of the proposed revisions. The below lists summarize ports that are subject to the existing Regulation and ports and MTCs that would likely be subject to control requirements under the draft regulatory revisions, based on the proposed port and terminal thresholds and 2017 vessel activity information.

2. Expanding the types of vessels covered by the Regulation

The draft regulatory revisions would expand the scope of covered vessels to include auto carriers, roll on-roll off (Ro-Ro) vessels, crude tankers, and product tankers. This requirement would include diesel-fueled auxiliary engines, as well as auxiliary engines that operate on liquefied natural gas (LNG) engines and other alternative fuels.

Regulated vessels would be required to use a CARB-approved air emissions control strategy, such as shore power, a barge or land-based capture and control system, or other to-be-determined control technology, to control emissions while at berth. The draft regulatory revisions would also require boiler emissions controls for crude tankers operating boiler-powered, steam-driven pumps to off-load cargo (typically crude products). To obtain CARB approval, a control technology must be able to show that it can reduce a vessel’s emissions by at least 80 percent from the default emissions of an ocean-going vessel’s auxiliary engine and boiler.

3. Changing the threshold for when emission control requirements are triggered

The draft regulatory revisions would base emission control requirements on the number of annual visits made by regulated vessel types to specific ports and terminals by setting vessel visit thresholds for ports and terminals.

  • Ports, MTCs, and vessels visiting these locations would be subject to control requirements through the draft regulatory revisions if the port or MTC receives 50 or more visits annually from container, reefer or auto/Ro-Ro vessels, or 25 or more visits from cruise or tanker vessels.

For ports and MTCs that exceed the annual port visit threshold for a specific vessel type:

  • Individual terminals at the port or MTC that receive that type of vessel would then be required to reduce emissions from vessels at berth if they receive 25 or more visits annually from container, reefer or auto carriers and Ro-Ro vessels, or five or more visits annually from cruise or tanker vessels.

These thresholds were set considering past activity and per vessel emission levels for different vessel types.

CARB is scheduled to take the New Regulation to CARB in December 2019 for final review and approval. The official public comment period opens October 11, 2019. However, CARB will take comments at any time regarding the upcoming workshops (discussed below).

Upcoming workshop information

CARB will hold public workshops on May 14 and on May 16, 2019 to discuss these updated draft regulatory concepts for the New Regulation.

For more information

If you are interested in submitting comments or would like more information on the draft regulatory revisions or implementation timeline, please contact the authors or a member of Reed Smith’s Transportation Group.

For further information please download the current Regulation and the Draft revisions to the Regulation below.