EPA's Vessel General Permit and Small Vessel General

Table 25. Receiving Water Model Scenarios Assessed by EPA.
Model
Scenario
Number
Harbor Scenario RAA Loading Scenario
1 Estuary mixing driven by tidal influence Seattle Pollutant Load
2 Estuary mixing driven by tidal influence Houston Pollutant Load
3 Estuary mixing driven by tidal influence New York Pollutant Load
4 Estuary mixing driven by tidal influence San Francisco Pollutant Load
5 Estuary mixing driven by tidal influence Miami Pollutant Load
6 Estuary mixing driven by river inflow Seattle Pollutant Load
7 Estuary mixing driven by river inflow Houston Pollutant Load
8 Estuary mixing driven by river inflow New York Pollutant Load
9 Estuary mixing driven by river inflow San Francisco Pollutant Load
10 Estuary mixing driven by river inflow Miami Pollutant Load
11 Minimum river flow St. Louis Pollutant Load
12 Minimum river flow Duluth Pollutant Load
13 Maximum river flow St. Louis Pollutant Load
14 Maximum river flow Duluth Pollutant Load
EPA stated that it believed the scenarios modeled to be representative of the types of water
bodies where VGP and sVGP vessels likely operate based on the wide geographical range of
waterbodies used to develop the input values. By selecting the minimum water characteristic
values for the harbor scenarios, and evaluating the maximum pollutant loading values from the
seven RAAs, EPA also believed that the model scenarios reasonably capture a “worst case”
scenario within the action area applicable to the BE. Table 26 lists the receiving water
concentrations estimated from the 10 estuary harbor exposure scenarios modeled. Table 27 lists
the receiving water concentrations estimated from the four river harbor exposure scenarios
modeled.
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