Der Ausblick von der Flussmndung Hinauf zu den Bergen

1
Der Ausblick von der Flussmündung Hinauf zu den
Bergen

• Herr Doctor Khalil E. Abu-Saba

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The View from DownstreamKhalil Abu-Saba San
Francisco Bay Regional Water Quality Control Board

• Manage in the watersheds.
• Measure in the water.

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Overview
Connecting downstream data to upstream
watersheds

• What chromium and silica taught us
• The mercury story in California

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The usual caveats...

• This discussion is not about
• The will or intent of the Regional Board, the
  State Board, or the State of California
• The anticipated outcome of any public process

• This discussion is about
• Published historic accounts
• Public information (hearings, staff reports,
  peer-reviewed science)
• Staff recommended actions

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Hydrology Geography Geochemistry
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Summer Low Flow
Winter High Flow
Chromium
Silica
Flow
Details in Abu-Saba and Flegal (1997)
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First Point The View from Downstream

• Chromium and Silica are geochemical tracers
• We can see the effect of shifting freshwater
  sources downstream
• Winter 1993 pulses of waters entered estuary
• Chromium / Aluminum ratios also showed a shifting
  sediment source in Winter 1993

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Second Point The View from Downstream

• The story of mercury in California is recorded in
  the sediments

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RMP Base Program Data
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Design Integration Workgroup
Current Background
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State TMDL funds to evaluate Pre-human condition
of Lower South Bay
Current 0.40
Baseline 0.06
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Guadalupe River Mercury TMDL Spearheaded by SCVWD
New Almaden
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RMP Air Deposition Study and relevance to
contemporary background
Global
Regional
Air Dep.
?
0.34 ppm
?
Mining
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Investigation of remote watershed sources
CALFED CVRWQCB UCSC
1.2
Mercury in
0.8
Bottom
Winter 1993
Sediments (µg/g)
0.4
0.0
0
50
100
Fines (
Clay
Sand
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Link to Beneficial Uses Methylmercury studies by
CALFED, BASMAA, SCVWD, UCSC
Methylation
Bioaccumulation
Total Mercury
Bacteria in wetlands, mudflats and sloughs
Methylmercury

• Mercury is methylated in the margins of the Bay
• Methylation rates highest at the fresh-salt
  interfaces
• High total mercury concentrations ALWAYS
  associated with high methylmercury concentrations
• High methylmercury concentrations OFTEN, but NOT
  ALWAYS associated with high total mercury
  concentrations

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Basin Plan Narrative Objective for
Bioaccumulation

• Controllable water quality factors shall not
  cause a detrimental increase in the
  concentrations of toxic substances found in
  bottom sediments or aquatic life. Effects on
  aquatic organisms, wildlife, and human health
  will be considered.

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Third Point The View from Downstream

• RMP Base Program sets the stage
• Pilot, special, and external studies address key
  uncertainties
• Todays talk
• SFEI, State, CALFED, BASMAA, SCVWD, CVRWQCB,
  UCSC.
• Many many others
• POTW ultra-clean monitoring, near-field
  methylmercury measurements, SFEI consumption
  study, RMP fish surveys...
• Keep those cards and letters coming!

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But What Does it All Mean?