Presentation Abstract
The Washington State Department of Ecology (Ecology) evaluated the potential transport, dispersion and dilution of potential vessel sewer discharges within the draft proposed Puget Sound No Discharge Zone (NDZ). These model simulations included potential vessel sewer discharges at six locations in Puget Sound along major shipping routes. Results are presented as virtual animations of surface concentrations, allowing us to visualize the transport, circulation, and dilution of these discharges over the course of several days.
Ecology and Pacific Northwest National Laboratory jointly developed a three-dimensional hydrodynamic FVCOM (Finite Volume Coastal Ocean Model) computer model of the Salish Sea. This model is forced by tides at the mouth of the Strait of Juan de Fuca, meteorological boundary conditions, and freshwater inputs from the US and Canada that induce estuarine circulation. The model has been calibrated to water surface elevations and profiles for the year 2006.
Potential discharges were simulated using the sediment module of the model, with zero settling velocity. The model allows us to evaluate connectivity between points of discharge and other parts of Puget Sound, and calculate the degree of dilution that has occurred before discharges reach specific geographic points of interest. Model simulations show the strong influence of tidal cycles on the movement of vessel sewer discharge. At some locations, freshwater inflows into Puget Sound from rivers also influence the movement and dilution. We found that there are several periods when fecal coliform bacteria concentrations typical of raw sewage would not meet the water quality standard based on dilution alone.
Since its development, Ecology has used the model for a number of applications to evaluate how potential point and nonpoint source discharges (e.g. wastewater facilities, vessel sewage discharges, and rivers) circulate once released into marine waters.
Session Title
General Pollution Topics
Conference Track
Fate and Effects of Pollutants
Conference Name
Salish Sea Ecosystem Conference (2016 : Vancouver, B.C.)
Document Type
Event
Start Date
2016 12:00 AM
End Date
2016 12:00 AM
Location
2016SSEC
Type of Presentation
Oral
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Sewage disposal in the ocean--Washington (State)--Puget Sound--Simulation methods; Referendum--Washington (State)--Puget Sound--Environmental conditions; Dilution--Simulation methods
Subjects – Names (LCNAF)
Washington (State). Department of Ecology
Geographic Coverage
Puget Sound (Wash.); Salish Sea (B.C. and Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
Included in
Fresh Water Studies Commons, Marine Biology Commons, Natural Resources and Conservation Commons
Virtual simulations of potential vessel discharges in Puget Sound and the Puget Sound No Discharge Zone
2016SSEC
The Washington State Department of Ecology (Ecology) evaluated the potential transport, dispersion and dilution of potential vessel sewer discharges within the draft proposed Puget Sound No Discharge Zone (NDZ). These model simulations included potential vessel sewer discharges at six locations in Puget Sound along major shipping routes. Results are presented as virtual animations of surface concentrations, allowing us to visualize the transport, circulation, and dilution of these discharges over the course of several days.
Ecology and Pacific Northwest National Laboratory jointly developed a three-dimensional hydrodynamic FVCOM (Finite Volume Coastal Ocean Model) computer model of the Salish Sea. This model is forced by tides at the mouth of the Strait of Juan de Fuca, meteorological boundary conditions, and freshwater inputs from the US and Canada that induce estuarine circulation. The model has been calibrated to water surface elevations and profiles for the year 2006.
Potential discharges were simulated using the sediment module of the model, with zero settling velocity. The model allows us to evaluate connectivity between points of discharge and other parts of Puget Sound, and calculate the degree of dilution that has occurred before discharges reach specific geographic points of interest. Model simulations show the strong influence of tidal cycles on the movement of vessel sewer discharge. At some locations, freshwater inflows into Puget Sound from rivers also influence the movement and dilution. We found that there are several periods when fecal coliform bacteria concentrations typical of raw sewage would not meet the water quality standard based on dilution alone.
Since its development, Ecology has used the model for a number of applications to evaluate how potential point and nonpoint source discharges (e.g. wastewater facilities, vessel sewage discharges, and rivers) circulate once released into marine waters.
