EPA and the IMO have been tightening marine vessel emission standards since 1999 for all marine engine categories. Early regulations focused on standards that are implemented at the time the vessel is constructed and only affect U.S.-flagged ships. Recently, Emission Control Area (ECA) rules have been developed that require all vessels traveling through the North America ECA (NA-ECA) to comply with the IMO’s international schedule of emission and fuel standards.
The NA-ECA includes waters within 200 nautical miles of the coast for most of the United States, Canada, and the Caribbean. EPA implemented this regulatory program under Annex VI of the International Convention for the Prevention of Pollution from Ships. The program has taken the following actions:
• In 2012, the NA ECA imposed a limit on fuel sulfur at 10,000 ppm.
• In 2015, the NA ECA further reduced the limit on fuel sulfur to 1,000 ppm.
• For vessels with keel-laying on or after January 1, 2016, NOx standards go into effect and require application of control devices that that will reduce NOx emission by 85 percent while operating in designated ECAs.
The ECA sulfur rule allows ship owners to either use fuels that are compliant with the sulfur concentration requirement or continue to use high-sulfur fuels in conjunction with scrubbers that provide an equivalent reduction in sulfur emissions. The extent to which vessels will switch to lower-sulfur fuels or use scrubbers is uncertain. In addition, Annex VI lowers the global limit on marine fuel sulfur content in 2020 to 5,000 ppm.
Mexico is currently developing a similar program for vessels that transit a proposed Mexican Emission Control Area. Additional International Maritime Organization (IMO) backed ECAs are being considered for waters near Japan, off the coast of Norway, and in the Mediterranean Sea. China has moved forward with its own ECA-like requirement for fuel sulfur limits for vessels at ports (0.5% or less sulfur) in several port areas, with plans to have their program aligned with IMO ECA standards by 2019.[TMS1] Australia has imposed fuel sulfur limits (0.1% or less sulfur) in Sydney Harbor for cruise ships at berth. Within the United States, the State of California has adopted an “Ocean-going Vessel Fuel Rule” which places similar limits as Annex VI on sulfur content but further restricts fuel to marine distillate categories of marine gas oil (MGO) or marine diesel oil (MDO), resulting in a more stringent standard but one also inconsistent with IMO standards.
Though ECA rules apply to all vessels, smaller ships equipped with Category 1 and Category 2 diesel engines are required to comply with non-road standards for engines that have been manufactured from 1996 to 2018 and vary by regulated pollutant depending upon cylinder displacement, power, and engine speed. Nonroad fuels also have significantly lower sulfur concentrations (500 ppm) than required in the ECA regulations (1,000 ppm).
In addition, the IMO has put forth requirements focused on improving vessel efficiency, which reduces fuel use (and resulting greenhouse gases and other emissions).
Voluntary programs are also being used by ports to reduce emissions, these include:
· Expansion of reduced speed zones
· Use of ultra-low sulfur fuels for auxiliary engines
· Programs to promote alternative fuels including LNG
· Efforts to encourage use of shore power
· Repowering or replacing older harbor craft
· Use of advance marine emission control systems
· Scrappage of older high emitting drayage trucks
· Drayage truck/gate scheduling systems
· Dockside efficiency improvements
· Replacing diesel cargo handling equipment with natural gas powered equipment
· Electrification of cargo handling equipment
· Replacement of diesel-powered gantry cranes with electric cranes equipped with regenerative power
· Encouraging intermodal shift from onroad to rail
· Use of LNG or CNG powered Locomotives
Knowledge of current and pending international, regional, or national regulatory instruments is necessary to accurately quantify anticipated emission levels within a port or region, or to estimate benefits associated with the implementation of more-stringent local standards or voluntary programs.