In 2005, the Lake Carriers’ Association, with assistance from the Ports of Cleveland and Deluth, undertook a “bottom-up” approach and developed an Air Emission Inventory (AEI) for two ports on the Great Lakes. The details of every commercial vessel – U.S.-, Canadian-, and Foreign-Flag – and every visit to each port were cataloged for 2004. The actual open-lake speed, reduced speed to enter the port, the time to maneuver from the breakwall to the dock, and the times at the dock performing cargo operations was evaluated. Accurate emission factors for the type of propulsion engine and auxiliary engines for each vessel were used for the times in each mode to obtain total emissions.
The Port of Cleveland, Ohio, is particularly important because that port was studied as part of the EPA’s National Emission Inventory in 1999 and 2002 and those results were used as the marine transportation mode emissions baseline that is extrapolated to all other Great Lakes port states, cities, and counties based on port tonnages. The Port of Duluth, Minnesota, was chosen because it is primarily a shipping port as contrasted to Cleveland, which is primarily a receiving port.
Vessel operations are quite different in each port. Using this detailed study and current emission factors, Great Lakes marine mode emissions were determined to be about one-half of the original EPA 2002 inventory estimates for the Cleveland nonattainment area. More information can be found in the Lake Carriers’ Association’s report entitled: Great Lakes Marine Air Emission: We’re Different Up Here!
