1. San Francisco Estuary Institute Small Tributaries Loading Study Zone 4 Line A, Cabot Blvd. Hayward Years 1-3 – Partial Data Review: Continuation to Year 4? Sources Pathways and Loadings Workgroup May 27 th 2009 Alicia Gilbreath and Lester McKee Item #6

2. San Francisco Estuary Institute

3. To scale by watershed area. 3

4. 4 ~5 % impervious ~70 % impervious ~25 % impervious To scale by % imperviousness. San Francisco Estuary Institute

5. Season Sample Inventory Item #6 San Francisco Estuary Institute 200720082009 HgT403230 HgD, MeHgT, MeHgD201610 HgR9 PCBs203216 PBDEs2085 OC Pesticides78 PAHs78 Trace Elements2116 Fe1610 SSC100 DOC, POC1613

6. Item #6 HgT range (n=86): 1.8 – 147 ng/L WY 2007 HgT Loads: 25 g: WY 2008 HgT Loads: 149 g WY 2009 data DRAFT and subject to change. HgD range (n=44): 0.8 – 7.1 ng/L San Francisco Estuary Institute

8. Item #6 HgT range (n=86): 1.8 – 147 ng/L WY 2007 HgT Loads: 25 g: WY 2008 HgT Loads: 149 g WY 2009 data DRAFT and subject to change. HgD range (n=44): 0.8 – 7.1 ng/L San Francisco Estuary Institute

9. Side-by-side Automated Sampling San Francisco Estuary Institute

10. Item #6 t-PCB range (n=60): 332 – 109,336 pg/L WY 2007 PCB Loads: 14 g, WY 2008 PCB Loads: 75 g WY 2009 data DRAFT and subject to change.

11. 11 San Francisco Estuary Institute Item #6

12. How many watersheds are like Z4LA? Drainage Area: 4.5 sq km Land Use: ~97 % Industrial + Commercial + Residential San Francisco Estuary Institute Item #6

13. San Francisco Estuary Institute Item #6 Years sampled so far

14. Pros and Cons of continuing monitoring at Z4LA: Decisions for moving forward Pros: - Established site - Have not yet fully characterized concentrations and loads - Intensely urban - Listed in the draft MRP as a monitoring site Con: - Not yet determined a linkage to contaminated high leverage Bay margin San Francisco Estuary Institute Item #6