1. Copper Source Loading Estimates (Process Profiles) Physical & Chemical Characterization of Wear Debris (Clemson University) Water Quality Monitoring (ACCWP) Steering Committee, Scientific Advisory Team, and Stakeholder Involvement Process (Sustainable Conservation) Air Deposition Modeling (AER) Watershed Modeling (U.S. EPA) Bay Modeling (URS) Final Report Data Assessment Conclusions Air Deposition Monitoring (SFEI) Representative Sample of Brake Pad Wear Debris (BMC/Link Test Labs) BPP Technical Studies

2. Conceptual Biogeochemical Model

3. Schematic of Numerical Model Hydrological Model Streamflows and Point Source Discharges Delta Outflow Velocity at depth Pacific Ocean tides Sediment and Water Quality Model Stream SSC Water column concentrations (dissolved and total) benthic sediment concentrations Ocean concentrations Delta concentrations Benthic sediment concentrations Point sources Air deposition

4. BPP Copper Bay Models Timescales Tidal (Seconds, minutes) Annual (days, months) Decadal Trends Hourly, Daily Concentration Timescale (computational timestep) Output Average Fluxes Average Benthic Concentrations

5. San Francisco Bay Water Quality Models MIKE 21 (DHI) –Tidal Time Scale Model –Two- Dimensional (Depth Averaged) –Hydrodynamic, Sediment, and Chemical submodels Box Model (EPA WASP or SFEI multi-box model) –Daily/Monthly Time Scale –Fully Mixed –Long-term estimates –Fluxes and Benthic Concentrations driven by Tidal Model MIKE 21 (DHI) –Tidal Time Scale Model –Two- Dimensional (Depth Averaged) –Hydrodynamic, Sediment, and Chemical submodels Box Model (EPA WASP or SFEI multi-box model) –Daily/Monthly Time Scale –Fully Mixed –Long-term estimates –Fluxes and Benthic Concentrations driven by Tidal Model

6. Processes/Sources included Bay Water Quality Model Processes –Water advection and diffusion (tides) –Sediment resuspension, deposition, and transport –Copper-sediment adsorption/desorption –Benthic sediment pore water exchange Copper Sources –Watershed inputs –POTW Inputs –Direct atmospheric deposition –Release from copper anti-fouling paints –Bay sediment toxic hotspots Processes –Water advection and diffusion (tides) –Sediment resuspension, deposition, and transport –Copper-sediment adsorption/desorption –Benthic sediment pore water exchange Copper Sources –Watershed inputs –POTW Inputs –Direct atmospheric deposition –Release from copper anti-fouling paints –Bay sediment toxic hotspots

7. Baseline Hydrologic Data Used to Develop Model USGS NOAA/NOS Stanford University NCDC NGDC DWR URS Data

8. MIKE 21 Water Quality Model Calibration Existing Data –NOAA/USGS/RMP/RWQCB/Literature Calibrated to Water Column Concentrations URS Additional Measurements: –Pore Water Concentrations –Copper Adsorption and Desorption Rates –Benthic Sediment Concentrations Existing Data –NOAA/USGS/RMP/RWQCB/Literature Calibrated to Water Column Concentrations URS Additional Measurements: –Pore Water Concentrations –Copper Adsorption and Desorption Rates –Benthic Sediment Concentrations

9. Bathymetry Used in Model (200 meter grid)

10. BPP Model Scenarios Baseline conditions –Representative WY Types (Wet Dry, Normal) –Estimate Sediment Residence Times Scenario 1 –Reduce Watershed Loads To Reflect Phase Out of Copper in Brake Pads Scenario 2 –Increase Watershed Loads to Reflect Increased Copper in Brake Pads Scenario 3 Baseline conditions –Representative WY Types (Wet Dry, Normal) –Estimate Sediment Residence Times Scenario 1 –Reduce Watershed Loads To Reflect Phase Out of Copper in Brake Pads Scenario 2 –Increase Watershed Loads to Reflect Increased Copper in Brake Pads Scenario 3

11. Example Presentation of Differences in Dissolved Copper Concentration between Baseline and Two Scenarios (4 day average) Scenario 1 Scenario 2

12. Dissolved Copper Concentration - Storm Event (whole Bay movie)

13. Dissolved Copper Concentration – Dry Season (whole Bay movie)

14. Dissolved Copper in the South Bay

15. Previous Sensitivity to Changes in Tributary Loads Tripled Tributary Loads Evaluated changes in average dissolved copper at one location over six months Dissolved Copper increased by up to 1.2 ug/L Tripled Tributary Loads Evaluated changes in average dissolved copper at one location over six months Dissolved Copper increased by up to 1.2 ug/L

16. Discussion