selenium in san francisco bay status: possibly impaired standards: –relevant beneficial uses:...

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Selenium in San Francisco Bay Status: Possibly Impaired Standards: Relevant Beneficial Uses: Fishing, wildlife habitat, rare and endangered species Water Quality Objectives 5 ppb (total in water) – attained everywhere but Alviso Slough Narrative for bioaccumulation – much improvement 1986 - 2002 Reserved in CTR pending agency consultations Conceptual Model Importance of chemical speciation Uncertainties Risk assessment, future loads, Alviso Slough www.cleanestuary.org Dr. Khalil E. Abu- Saba [email protected] Dr. Scott Ogle Rocks!

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Page 1: Selenium in San Francisco Bay Status: Possibly Impaired Standards: –Relevant Beneficial Uses: Fishing, wildlife habitat, rare and endangered species –Water

Selenium in San Francisco Bay• Status: Possibly Impaired• Standards:

– Relevant Beneficial Uses:• Fishing, wildlife habitat, rare and endangered species

– Water Quality Objectives• 5 ppb (total in water) – attained everywhere but Alviso Slough• Narrative for bioaccumulation – much improvement 1986 - 2002• Reserved in CTR pending agency consultations

• Conceptual Model– Importance of chemical speciation

• Uncertainties– Risk assessment, future loads, Alviso Slough

www.cleanestuary.org

Dr. Khalil E. Abu-Saba

[email protected]

Dr. Scott Ogle Rocks!

Page 2: Selenium in San Francisco Bay Status: Possibly Impaired Standards: –Relevant Beneficial Uses: Fishing, wildlife habitat, rare and endangered species –Water

The story of migrating birds is the story of a promise, a promise to return. They fly, often thousands of miles, beset with danger, for a single reason: to survive.Their migration is a fight for life.

Winged Migration

The Tone:

What captures the

imagination…

http://www.werc.usgs.gov/scoter/maps.html

WILD

(Wildlife Habitat)

Page 3: Selenium in San Francisco Bay Status: Possibly Impaired Standards: –Relevant Beneficial Uses: Fishing, wildlife habitat, rare and endangered species –Water

…isn’t always the issue.

Exposure

Health

Deficient Toxic

Human Dietary requirements = 40 - 300 g / day

Human NOEL = 850 g / day

Original Basis for Impairment:

•Selenium in diving ducks exceeded risk assessment thresholds for people who hunt and eat ducks

•OEHHA Consumption Advisory as published in (older) CDFG game regulations

•Technical basis published in Fan et al. (1989)

COMM: “Uses of water for commercial or recreational collection of fish, shellfish, or other organisms in oceans, bays, and estuaries, including, but not limited to, uses involving organisms intended for human consumption or bait purposes.

Page 4: Selenium in San Francisco Bay Status: Possibly Impaired Standards: –Relevant Beneficial Uses: Fishing, wildlife habitat, rare and endangered species –Water

1986 2002 1986 2002 1986 2002

San Pablo South Bay Suisun

1988 2002

Dr. Scott Ogle Rocks!

Things Change…

Changes in San Francisco Bay diving duck tissue selenium concentrations over time. Base Graphs courtesy of the Regional Monitoring Program/San Francisco Estuary Institute.

Page 5: Selenium in San Francisco Bay Status: Possibly Impaired Standards: –Relevant Beneficial Uses: Fishing, wildlife habitat, rare and endangered species –Water

Selenium concentrations in white sturgeon, 1986-2000. Base Graphs courtesy of the Regional Monitoring Program/San Francisco Estuary Institute.

…sometimes for the better.

Dr. Scott Ogle Rocks!

Page 6: Selenium in San Francisco Bay Status: Possibly Impaired Standards: –Relevant Beneficial Uses: Fishing, wildlife habitat, rare and endangered species –Water

dissolved selenate

dissolved selenite

dissolved organo-selenium

particulate elemental selenium

pythoplankton / particulate organo-selenium

Particles Solution

But why?Chemical Speciation

Page 7: Selenium in San Francisco Bay Status: Possibly Impaired Standards: –Relevant Beneficial Uses: Fishing, wildlife habitat, rare and endangered species –Water

dissolved selenate

dissolved selenite

Ag drainage

Refineries

dissolved organo-selenium

particulate elemental selenium

pythoplankton / particulate organo-selenium

Evasion

clams

birds and fish people

90% load reduction by 1998

bacteria

(sulfate inhibited)

Dimethylselenide

transport

transform

bioaccumulate

bacteria

Sac. R.

OceanOcean

Biogeochemical Transformation

Invasive Hyperaccumulator

Page 8: Selenium in San Francisco Bay Status: Possibly Impaired Standards: –Relevant Beneficial Uses: Fishing, wildlife habitat, rare and endangered species –Water

5.49

0.270.02

0

1

2

3

4

5

6

Mean 1987-88 May 2000 August 2000

Sele

nit

e C

on

cen

trati

on

g/L S

e)

Before

After

Refinery "A"

59.06

4.882.48

0

10

20

30

40

50

60

70

Mean 1987-88 May 2000 August 2000

Sele

nit

e C

on

cen

trati

on

g/L S

e)

Before

After

Refinery "B"

4.32

0.06 0.09

0

1

2

3

4

5

Mean 1987-88 May 2000 August 2000

Sele

nit

e C

on

cen

trati

on

g/L S

e)

Before

After

Refinery "C"

50.22

1.56

4.78

0

10

20

30

40

50

60

Mean 1987-88 May 2000 August 2000

Sele

nit

e C

on

cen

trati

on

g/L S

e)

Before

After

Refinery "D"

22.19

0.16 0.040

5

10

15

20

25

Mean 1987-88 May 2000 August 2000

Sele

nit

e C

on

cen

trati

on

g/L S

e)

Before

After

Refinery "E"

0.031

0.06

0.015 0.016

0.049

0.104

0

0.02

0.04

0.06

0.08

0.1

0.12

April 1986 Sept 1986 April 1999 Nov 1999

Sele

nit

e C

on

cen

trati

on

g/

L S

e)

mean Selenite

maximum Selenite Before

After

Northern San Francisco Bay

Load Reduction

Dr. Scott Ogle Rocks!

Page 9: Selenium in San Francisco Bay Status: Possibly Impaired Standards: –Relevant Beneficial Uses: Fishing, wildlife habitat, rare and endangered species –Water

Key Uncertainties

50,000 kg1,000,000

- 160,000,000 kg Se

2,000 - 20,000 kg Se / yr

Selenium Reservoir

in San Joaquin

Valley

AB

C

D

E

0

5

10

Artesia

n slo

ugh

Alviso

Slou

gh

Guada

lupe

Slough

Lower

Sou

th B

ay

South

Bay

Centra

l Bay

North

Bay

Sel

eniu

m (

ug

/L)

CTR Chronic Objective

1) Why is Alviso Slough so high in Selenium?

2) What is future irrigated agriculture load?

Page 10: Selenium in San Francisco Bay Status: Possibly Impaired Standards: –Relevant Beneficial Uses: Fishing, wildlife habitat, rare and endangered species –Water

Another Key Uncertainty

y = 0.0036x

0

0.5

1

1.5

2

2.5

3

3.5

0 20 40 60 80 100

( Fines)< 63microns %

[Se]

(ug

/g)

Mar.' 93, Aug. '94 - Aug. '01

Aug '93

Feb '94

Linear (Mar.' 93, Aug. '94 -Aug. '01)Linear (Aug '93)

Grizzly Bay