San Francisco Estuary Institute
Small Tributaries Loading StudyZone 4 Line A, Cabot Blvd. Hayward
Years 1-3 – Partial Data Review: Continuation to Year 4?
Sources Pathways and Loadings Workgroup
May 27th 2009
Alicia Gilbreath and Lester McKee
Item #6
San Francisco Estuary Institute
To scale by watershed area.
3
4
~5 % impervious
~70 % impervious
~25 % impervious
To scale by % imperviousness.
San Francisco Estuary Institute
Season Sample Inventory Item #6
San Francisco Estuary Institute
2007 2008 2009
HgT 40 32 30
HgD, MeHgT, MeHgD 20 16 10
HgR 9
PCBs 20 32 16
PBDEs 20 8 5
OC Pesticides 7 8
PAHs 7 8
Trace Elements 21 16
Fe 16 10
SSC 100 100 100
DOC, POC 16 13
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/LSan Francisco Estuary Institute
WY 3 First Flush, Saturday November 1, 2008
0:00 4:00 8:00 12:00 16:00 20:00 0:00
Sta
ge (
ft)
0.0
0.5
1.0
1.5
2.0
2.5
Tur
bidi
ty (
NT
U)
0
200
400
600
800
1000
Stage Turbidity at Sampling Event
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/LSan Francisco Estuary Institute
Side-by-side Automated Sampling
SampleID HgT (ng/L)Z4LA-371 15Z4LA-371 - ISCO 26.1Z4LA-372 13Z4LA-372 - ISCO 13.5
San Francisco Estuary Institute
San Francisco Estuary Institute
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.
11San Francisco Estuary Institute
Item #6
t-P
BD
Es
t-P
AH
s
t-D
DT
s
t-C
hlor
dane
s
t-H
CH
s
Die
ldrin
pg/L ng/L pg/L pg/L pg/L pg/L
WY 2007 Min 2,824 1,373 7,420 3,466 300 711Max 141,218 19,668 59,480 16,400 891 4,590n= 7 7 7 7 7 7
WY 2008 Min 348 14 408 318 ND 257Max 13,252 1,415 3,800 1,856 375 634n= 8 8 8 8 8 8
WY 2009 n= 5 0 0 0 0 0
How many watersheds are
like Z4LA?
• Drainage Area: 4.5 sq km• Land Use:
~97 % Industrial + Commercial + Residential
San Francisco Estuary Institute
Item #6
San Francisco Estuary Institute
Item #6
Years sampledso far
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 siteCon:
- Not yet determined a linkage to contaminated “high leverage” Bay margin
San Francisco Estuary Institute
Item #6