1. 1 Regional Data Review : What have we learned in eight years? Lester McKee Sources Pathways and Loadings Workgroup Monday December 8 th 2008 San Francisco Estuary Institute Item #4

2. 2 Evolution of knowledge - Hg loads (2000-2008): two loads studies make a large difference (Ref: McKee et al., 2008) Item #4

3. 3 Evolution of knowledge PCB loads (2002-2008 ): two loads studies make a large difference (Ref: McKee et al., 2008) Item #4

4. 4 How quick do people or instruments need to respond to collect samples? (40 acres) Guadalupe R. (8-10 hrs) Zone 4 Line A (1.5 hrs) (4 acres) City Block (12 min) (Ref: McKee et al., 2003) Item #4 San Francisco Estuary Institute

5. 5 Mercury Load = 6 – 440 kg (Ref: McKee et al., 2005) How many data do we need to estimate loads of a specified accuracy? Mercury Load = 0.025 – 1,075 kg Mercury Load = 80 – 220 kg Item #4 San Francisco Estuary Institute

6. 6 How many data do we need to estimate loads of a specified accuracy? Item #4 Sampling program running for consecutive years 5-year7-year10-year15-year Exceed 1.5 year return (1,950 cfs) 100100100100 Exceed 2 year return (2,400 cfs) 100100100100 Exceed 3.3 year return (6,900 cfs) 89100100100 Exceed 5 year return (9,200 cfs) 748593100 Exceed 10 year return (13,600 cfs) 37527388 San Francisco Estuary Institute

7. 7 Sampling year (s) Estimated long term PCB load (kg) WY 03 only 1.6 WY 04 only 1.9 WY 05 only 0.8 WY 06 only 0.7 WY 03 & 04 1.7 WY 04 & 05 1.0 WY 05 & 06 0.7 WY 03 & 04 & 05 1.1 WY 04 & 05 & 06 0.8 All years 0.9 How many data do we need to estimate loads of a specified accuracy? Item #4 San Francisco Estuary Institute

8. 8 When within a year should we sample? Alameda Ck. at Niles 10% urban, 1,650 km 2 Colma Ck. at S. San Francisco 57% urban, 41 km 2 Coyote Ck. at Gilroy ??% urban, 275 km 2 Water Discharge Suspended Sediment Load 17% 1% Dry season Wet season Item #4 San Francisco Estuary Institute

9. 9 Grain size and turbidity as a surrogate Item #4 San Francisco Estuary Institute

10. 10 Is it better to measure or estimate concentrations and loads: the Guadalupe River example SS(t/y)HgAgAsCdCrCuNiPbZnPCBDDTChlor-dane Estimated long term Average (1973 - 02) 13,9701304110121,6708903,2401,0003,7400.91.71.6 Davis et al., 20006,200801,1602,2401,6703,40011,200 KLI, 2002 5.42.10.62.2 Leatherbarrow et al., 2003 11,00029323091,4007002,0005003,100 Thomas et al., 2002 4.0 - 30 All loads in kg unless otherwise specified. Item #4 San Francisco Estuary Institute

11. 11 How much do particle Hg concentrations vary between watersheds?  Z4LA < Coyote (non-urb) < Coyote (urb) < San Pedro < Guadalupe R. Item #4 San Francisco Estuary Institute

12. 12 How much do particle PCB concentrations vary between watersheds?  Coyote (non-urb) < Coyote (urb) < Guadalupe R. < Z4LA Item #4 San Francisco Estuary Institute

13. 13 How much do particle PBDE concentrations vary between watersheds?  Coyote (non-urb) < Guadalupe (non-urb) < Coyote (urb) < Guad (urb) < Z4LA Item #4 San Francisco Estuary Institute

14. 14 Which storms need to be studied and does this vary for each POC?  If only storms of 10 cfs had been sampled for Hg, the estimated average particle concentration would be 1.7x higher than sampling 100 cfs  In contrast, the difference would be only 1.4x for PCBs  POC, method, and targeted storms matter Item #4 Z4LA WY 2007 data San Francisco Estuary Institute

15. 15 Which and how many watersheds should be sampled? Area (km 2 ) Area (km 2 ) SS (t/km 2 ) Hg MeHg AgCd Cr Cu Ni Pb Zn PCB PBDE DDT Chlordane Dieldrin Hayward Urban watershed (Z4LA WY 2007) 4.5245.60.168.0431,4002,5001,8001,80021,0003.29.03.71.30.30 Guadalupe River (WY 2004) 23636640.08812.6412,7123,0085,0852,20312,7123.36.73.32.50.26 Statistically significant? yesyesmaybenonoyesnoyesnoyesnononomaybeno Export of POC during climatic years with 70% mean annual runoff (units: micrograms per square meter (µg/m 2 ) unless otherwise specified Item #4 San Francisco Estuary Institute

16. 16 Is mercury always particulate and inorganic? (San Pedro, Storm Drain (San Jose)) 65% HgD(%) MeHgT(%) 1% Item #4 San Francisco Estuary Institute

17. 17 Is mercury always particulate and inorganic? (Z4LA, Storm Drain (Hayward)) 36% HgD(%) MeHgT(%) 4% Item #4 San Francisco Estuary Institute