San Francisco Estuary Institute Small Tributaries Loading Study Zone 4 Line A, Cabot Blvd. Hayward Years 1-3 – Partial Data Review: Continuation to Year.

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