EPA's Vessel General Permit and Small Vessel General

for large cruise ships. The example below shows how daily bilgewater discharge was estimated
for cargo/bulk carriers using information for large cruise ships.
Example: 15,939 gross tons (cargo/bulk carrier)/53,526 gross tons (large cruise ship) x 3,570 g/day =
1,063 g/day
Table 8. Estimated Bilgewater Discharge Rates used in EPAs BE Analyses.
Vessel Type Estimated Bilgewater Discharge
Rates
(m 3 /day) (gallons/day)
Barges 0.18 47
Cargo/Bulk Carriers 4.0 1,063
Commercial Fishing 1.4 375
Large Cruise Ships 13.5 3,570
Medium Cruise Ships 2.0 305
Large Ferries 2.0 97
Oil and Gas Tankers 6.3 1,661
Passenger Vessels (e.g., water taxis, tour boats) 0.08 22
Utility Boats (tugs and tow boats) 0.14 37
EPA estimated concentrations of bilgewater pollutants based on data for vessels examined in the
Report to Congress. A total of eight bilgewater samples were collected from seven vessels with
a total of 128 analytes detected. The vessels sampled included two fishing vessels, two
tow/salvage vessels, a tour boat and two water taxis. Contaminants of concern in bilgewater
identified by EPA are listed in Table 9 and include conventional pollutants, nutrients, metals and
volatile/semivolatile organic chemicals (sVOCs/VOCs). Table 9 includes additional information
for these analytes from the Report to Congress, which provides details on the detection
frequency and distribution of all analytes detected in bilge water.
Table 9. Estimated Bilgewater Pollutant Concentrations used in EPAs Biological
Evaluation
Nutrients and
Conventional
Pollutants
Pollutant
Ammonia Nitrogen
(mg/L)
Total Phosphorous
(mg/L)
Total Residual Chlorine
(TRC, μg/L)
Total Suspended Solids
(TSS, mg/L)
Point
Estimate Used
in BE
1.7
3
0.077
39
Detection
frequency
Mean (range)
50 th /75 th /90 th
Percentiles b
4/5 1.7 (nd-7.6) 0.24/4/7.6
5/5 3 (0.084-13) 0.47/7.1/13
3/7 0.077 (nd a -0.16) nc c /0.13/0.16
7/7 39 (3.7-88) 38/71/88
244