EPA's Vessel General Permit and Small Vessel General

Vessel Type Average
Propulsion
Power (MW)
Estimated Saltwater
Exhaust Gas Scrubber
Washwater Discharge Rate
Estimated Freshwater
Exhaust Gas Scrubber
Washwater Discharge Rate
m3/hr gallons/hr m3/hr gallons/hr
Large Ferries 4.8 216 57,000 1 264
Oil and Gas
Tankersa
80 3,600 951,000 16 4,227
EPA estimated concentrations of exhaust gas scrubber washwater pollutants based on data from
the Zaandam Scrubber Trial (USEPA 2011b, Holland America Line and Hamworthy –
Krystallon. 2010), Table 15). Data provided in the trial report were point values and did not
include details on analytical observations.
Table 15. Estimated Exhaust Gas Scrubber Washwater Pollutant Concentrations used in
EPAs Biological Evaluation.
Pollutant Point Estimate
used in BE (μg/L)
Arsenic (dissolved) 81
Arsenic (total) 81
Copper (dissolved) 15
Nickel (dissolved) 12
Selenium (dissolved) 94
Selenium (total) 100
Benzo (a)-anthracene 0.262
Benzo (a)-pyrene 0.136
Chrysene 0.373
Fish Hold and Fish Hold Cleaning Effluent. All fishing vessels generate some form of fish
hold effluent. Fish hold effluent is composed of seawater, ice-melt, or ice slurry collected inside
fish hold tanks. Fish hold effluent contains pollutants which result from seafood catch and other
onboard vessel sources. These pollutants can include biological wastes, metals, and nutrients, as
well as wastewater resulting from fish hold cleaning activities.
Table 16 shows the volume of water discharged from various commercial fishing vessels during
fish holds in operation and during tank cleaning. Fish hold effluent discharge rates can range
from as low as 211 gal/day for a gillnetter to as high as 5,090 gallons per day for a tender vessel
while cleaning volumes range from 283 gal/day for purse seiners to 58 gallons per day for
trawlers (USEPA 2010b). The volume of fish hold effluent can vary from less than 100 gallons
during off-loading to tens of thousands of gallons for large fish tenders. EPA analyzed the risk
of this discharge in its BE due to the high number of vessels discharging, the large volume and
frequency of discharges, along with the potentially high risk posed by the concentration and
types of pollutant discharged.
251