BPP Technical Studies

Transcription

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

2 Bay Modeling Model Description

3 Conceptual Biogeochemical Model

4 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, Lower Resolution MIKE 21 or SFEI multi-box model) Daily/Monthly Time Scale Fully Mixed Long-term estimates Fluxes and Benthic Concentrations driven by Tidal Model

5 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

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

7 Bay Modeling Model Updates

8 BPP Bay Model Update Progress Input Direct Atmospheric Wet and Dry Deposition Input HSPF Watershed Flows and Copper Concentrations Input Marina Sources Calibration Checks Runtime Improvements

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11 BPP Model Scenarios Baseline conditions Representative WY Types (Wet, Dry, Normal) Scenarios - Reduce Watershed Loads To Reflect Phase Out of Copper in Brake Pads Scenario 1 Best Estimate BP Sources Scenario 2 Low BP Sources Scenario 3 High BP Sources

12 Previous Modeling Results

13 Dissolved Copper Concentration - Storm Event (whole Bay movie)

14 Previous Modeling Results Bay [Cu] Sensitive to Tributary Loads Modeled Residence Times Matrix Water Diss.Copper South Bay days days Lower South Bay 8-20 days days Ads.Copper Total Copper 6-9 years 6-7 years 1-4 years 1-2 years

15 Implications for Future Results Changes in Tributary Loads Can Result in Changes in Copper Concentrations in Bay Timescales for Changes Depends on Bay Segment Lower South Bay 1-2 years South Bay 6-8 years

16 Downcore Sediment Copper (ug/g) South Bay San Pablo Bay cm Cs Pre-1952 From Hornberger, et al. Marine Chem 64 (1999) 39-55

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18 Bay Modeling Calibration

19 Dissolved Copper Mass Balance Update Copper Mass Flux Rates BPP 1996 Wet Season 1997 Dry Season Annual Avg. Annual Bay Segment (10 3 kg yr -1 ) (10 3 kg yr -1 ) (10 3 kg yr -1 ) (10 3 kg yr -1 ) Entire Bay Sac San Joaquin Rivers Local Tributary Inflow POTW Inflow Direct deposistion 1.7 Marinas 13.2 Other Shoreline Releases 11 Desorption Diffusion Net Pacific Ocean Exchange Net Change Red are from BPP and not yet included in modeled estimates

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

22 MIKE 21 Water Quality Model Calibration Existing Data NOAA/USGS/RMP/RWQCB/City of San Jose/BP Wear Debris Leaching/Literature URS Additional Measurements: Pore Water Concentrations Copper Adsorption and Desorption Rates Benthic Sediment Concentrations Calibrated to Water Column Concentrations SSC, DCu

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

24 Bay Modeling Data Presentation

25 Dissolved Copper Concentration Dry Season (whole Bay movie)

26 Dissolved Copper in the South Bay

27 Differences in Dissolved Copper Concentration between Baseline and Two Scenarios (4 day average) Scenario 1 Scenario 2

28 Difference in Dry Season Maximum 4-Day Average Dissolved Copper MIKE 21 Results (kilometer) (kilometer) (kilometer) Diffuser shown in nested grid above, with center at approximately (0.8, 2.1) (kilometer) Difference in 4-Day Avg Dis Cu [ug/l] Above Below 0.003

29 Dry Season Maximum 4-Day Average Dissolved Copper Concentration Along Transect Parallel to South Bay Main Channel for All Modeled Scenarios Day Average Dissolved Cu Concentration (ug/l All POTWs, Including EBDA, at Existing Conditions Baseline EBDA at Permitted Discharge (Base Case) Scenario 1 EBDA at Proposed Discharge Scenario 2 EBDA at Proposed Discharge Increased with Zone 7 Reject Scenario Flow 3 EBDA at Proposed Discharge, Increased with Zone 7 Reject Scenario Flow and 4Decreased by Planned Recycling All POTWs at Permitted Discharge Scenario 5 All POTWs at 2025 Flows, with EBDA at Proposed Discharge Scenario Increased 6 with Zone 7 Reject Flow 1.85 N Distance along transect parallel to main channel from North to South along model axis, with origin at center of diffuser (ft) S

30 Probability Extraction Locations - Construction YERBA BUENA ISLAND SFO EAST BAY SHOALS BORROW SITE SOUTH BAY RESTORATION SITES DUMBARTON BRIDGE COYOTE CREEK Fig BX-R Fill Construction

31 Dissolved Copper Construction 100 EBS BORROW SITE Frequency (%) Existing A3 Hybrid BX-6 Hybrid BX-6 Fill BX-R Fill WQOs Dissolve d Copper (ug/l) Fig

32 Dissolved Copper Construction all locations

33 Bay Modeling Sensitivity

34 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

35 Bathymetry Used in Model (200 meter grid) C:\Projects\EBDA\data\bathy\mer200m_26c.dfs2 C:\Projects\EBDA\data\bathy\mer200m_26c.dfs (kilometer) (kilometer) Elevation (m, (m, NGVD) NGVD) Above Above Below Below

36 Dissolved Copper - Operation all locations