The Environmental Protection Agency (EPA) is proposing air emission standards for new marine diesel engines with per cylinder displacement at or above 30 liters (called Category 3 marine diesel engines) installed on US vessels. The proposed standards are equivalent to the nitrogen oxides (NOx) limits recently adopted in the amendments to MARPOL Annex VI. The near-term standards for newly-built engines would apply beginning in 2011. Long-term standards would begin in 2016 and are based on the application of high-efficiency after treatment technology. The EPA is also proposing a change to its diesel fuel program that would forbid production and sale of marine fuel oil above 1…