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Regional Data Review : What have we learned in eight years?

San Francisco Estuary Institute. Item #4. Regional Data Review : What have we learned in eight years?. Lester McKee Sources Pathways and Loadings Workgroup Monday December 8 th 2008. Item #4. Evolution of knowledge - Hg loads (2000-2008): two loads studies make a large difference.

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Regional Data Review : What have we learned in eight years?

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

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

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

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

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

  6. San Francisco Estuary Institute Item #4 How many data do we need to estimate loads of a specified accuracy?

  7. San Francisco Estuary Institute Item #4 How many data do we need to estimate loads of a specified accuracy?

  8. San Francisco Estuary Institute Item #4 When within a year should we sample? Dry season Wet season Colma Ck. at S. San Francisco 57% urban, 41 km2 Coyote Ck. at Gilroy ??% urban, 275 km2 Alameda Ck. at Niles 10% urban, 1,650 km2 17% Water Discharge 1% Suspended Sediment Load

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

  10. San Francisco Estuary Institute Item #4 Is it better to measure or estimate concentrations and loads: the Guadalupe River example All loads in kg unless otherwise specified.

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

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

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

  14. San Francisco Estuary Institute Item #4 Which storms need to be studied and does this vary for each POC? Z4LA WY 2007 data • 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

  15. San Francisco Estuary Institute Item #4 Which and how many watersheds should be sampled? Export of POC during climatic years with 70% mean annual runoff (units: micrograms per square meter (µg/m2) unless otherwise specified

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

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

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