12 June 2008

The California Air Resources Board (ARB) has released a proposed regulation that would require ocean-going vessels within 24 nautical miles off California’s coastline to use fuels of reduced sulfur content in their main and auxiliary engines, and boilers. The proposal was issued in spite of the court ruling that invalidated a similar earlier rule which was applicable to auxiliary ship engines.

The measure—to be considered by the ARB at its July 24/25 meeting—would annually affect about 2,000 ocean-going vessels, both US- and foreign-flagged, visiting California. The vessels would be required to use lower-sulfur marine distillates rather than the heavy-fuel oil (bunker fuel).

The regulation would be implemented in two steps. In 2009, marine gas oil (MGO) would have a sulfur limit of 1.5%, while marine diesel oil (MDO) would have a limit of 0.5%. In 2012, a sulfur limit of 0.1% (1000 ppm) would become effective for both fuels.

In 2005, the ARB adopted a similar rule that required ship auxiliary engines to use fuels of maximum 0.5% sulfur while in California waters effective 2007. The rule was challenged by the shipping industry, and stroke down by a court. Under the court ruling, the ARB must seek an EPA waiver for its marine engine regulation(s).

Source: California ARB