EPA regulations timeline
Tier 1: 2004
Tier 2: 2007-2013 0.9-7.0 liters per cylinder
Tier 3: 2012-2014 0.9-7.0 liters per cylinder
Tier 4: 2014-2017 max. power greater than 600 kW/804 hp
Tier 3 timeline
Displacement L/cyl
<0.9 L/cly >75 kW 2012
0.9-1.2 2013
1.2-2.5 2014
2.5-3.5 2013
3.5-7.0 2012
Existing vessel requirements
Emission standards generally apply only to new vessels, except in these cases:
Engine remanufacture: Replacement of all cylinder liners, either in one maintenance event or over the course of five years. Affects Tier 2 and earlier engines, larger than 600 kW/800 hp built after 1972 with a certified remanufacturing kit available.
Engine replacement: Replacing with a new or in some cases an existing engine.
Vessel refurbishing: Modifications that exceed 50 percent of the value of the modified vessel must use an engine that meets current guidelines.
Great Lakes exemption
Emissions regulations for the U.S. flag-Great Lakes fleet depend on the size and type of a vessel’s engine and the fuel it uses.
Smaller Category 1 and Category 2 engines with displacement less than 30 liters per cylinder must meet Tier 3 and Tier 4 emission standards using low-sulfur fuel.
Category 3 engines with displacement over 30 liters per cylinder must meet emissions standards set by MARPOL and use fuel that meets sulfur limits of 10,000 ppm, reduced to 1,000 ppm by 2015.
However, vessel operators may seek economic hardship and fuel availability waivers to use fuel that exceeds the sulfur content limits until 2015.
Steamships in service on the Great Lakes or Saint Lawrence Seaway prior to Oct. 30, 2009, are exempted from the fuel regulations.