1 / 17

San Francisco Estuary Institute Data Review 2008: Lessons Learned in Eight Years

Explore the evolution of knowledge on Hg and PCB loads, response times for sampling, data accuracy estimation, and watershed variability. Understand the importance of storm studies, particle concentrations, and sampling protocols.

elinor
Download Presentation

San Francisco Estuary Institute Data Review 2008: Lessons Learned in Eight Years

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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%

More Related