EPA's Vessel General Permit and Small Vessel General

EPA used information for commercial fishing vessels, passenger vessels and utility boats to
estimate deck washdown volumes (USEPA 2010b) for barges, cargo/bulk carriers, and oil and
gas tankers (Table 10).
EPA estimated the deck washdown volumes by comparing vessel gross tons for these vessels
with the gross tons of a typical utility vessel. EPA estimated utility vessels are 80 gross tons
based on 50% of the utility vessels being approximately 65 feet long (USEPA 2010b). For
medium and large cruise ships and large ferries, EPA estimated deck washdown volumes by
comparing vessel gross tons for these vessels with that of a typical passenger vessel. EPA
estimated passenger vessels are 35 gross tons based on 50% of passenger vessels being 45 feet
long (USEPA 2010b). The example below shows how EPA used the vessel gross tons and deck
washdown discharge volume for passenger vessels to estimate the deck washdown flow for large
ferries.
Example: 1,451 gross tons (large ferry)/35 gross tons (passenger vessel) x 27 g/day = 1,083
g/day
246