Educating and Informing the Public Regarding the Potential Impact of the Santa Susana Field Laborato

1
Educating and Informing the Public Regarding the
Potential Impact of the Santa Susana Field
Laboratory (SSFL) on its Surrounding Simi Valley
and East San Fernando Valley Communities
Yoram Cohen(a) and Dan Hirsch(b) (a) University
of California, Los Angeles(b) Partnership with
the Community to Bridge the Gap
2
SSFL History
3
SSFL History (Contd)
4
SSFL History (Contd)
5
The UCLA/CBG Effort
6
The UCLA/CBG Effort
7
(No Transcript)
8
OBJECTIVES of the Scientific Study

• TIER I WHAT ARE THE CONTAMINANTS
  OF CONCERN (COCs)?
• TIER II WHAT ARE THE POTENTIAL
  EXPOSURE PATHWAYS OF CONCERN?
• TIER III WHAT ARE THE AREAS OF EXPOSURE
  CONCERN?

9
Ranking Areas Chemicals of Concern
LADD Lifetime Average Daily Dose (mg/kg-d)
TI 1.
AT x Wx365
Where TI total intake (mg) over exposure
duration (yr) AT Averaging Time (70 yrs) W
weight (kg)
2. ALADD Acceptable Lifetime Rfd
(mg/kg-d) 10-6 risk
Average Daily Dose
(non-carcinogens) CPF (mg/kg-d)-1
(mg/kg-d)
(carcinogens)
Where CPF Cancer Potency Factor or Cancer Slope
Factor Rfd Reference Dose These
are EPA-estimated daily doses for which lifetime
exposures would not result in systemic
disease or cancer incidences greater than 10-6
DRgt 1 identifies potential chemical exposure
pathways or locations with doses above
EPA-acceptable doses.
3. DR Dose Ratio LADD (mg/kg-d)
ALADD (mg/kg-d)
10
SSFL Activities of Concern

• Rocket Engine Testing (1948 present)
• North Am. Aviation, Rocketdyne, Boeing
• Apollo Space Missions
• Hydrazine, Metals
• TCE Washing of Engines (1953 1992)
• Trichloroethene (TCE)
• 0.4 1.1 million gal used
• 313,000 gal in subsurface (3.7 million lb)

Air Stripping Towers (1955 present) - TCE,
metals - Carbon absorption / UV - No
reported emissions NPDES Discharges (1948
present) - RWQCB - Metals, Perchlorate,
PCBs Open Pit Burning (1958 1994) -
Dioxins, Furans, Metals - 1994 deaths /
violations
11
Water Flow

• - SSFL water drains to the north,
• south and east.
• - Flows in surface streams are
• intermittent.
• - Groundwater elevations
• at SSFL are higher than Simi
• and San Fernando Valleys
• Groundwater emerges at a number
• of springs in the canyons leading
• from SSFL into the valleys.

12
Offsite Wells or Spring Contamination
Vinyl Chloride 64 ?g/L, 3/94, 32XgtMCL
Chloromethane 19 ?g/L, 4/86, Livestock
well 12XgtTWSL
Benzene 3.8 ?g/L, 11/94, 3.8XgtMCL
TCE 670 ?g/L, 8/94, 134XgtMCL
1,1-DCE 19 ?g/L, 5/96, 3XgtMCL
Trans-1,2-DCE 38 ?g/L, 5/96, 3XgtMCL
RD-56
cis1,2-DCE 27 ?g/L, 5/96, 3XgtMCL
RD-38
Rural Agricultural
OS-5
RD-59
RD-32, RD-43
Light Agricultural
Carbon Tetrachloride 4.5 ?g/L, 2/95, 9XgtMCL
Outfall 001
Outfall 002
Manganese 390 ?g/L, 3/94, 7.8XgtMCL
Lead 50 ?g/L, 12/94, 4.2 Xgt MCL
Chromium 75 ?g/L, 1/93, 1.5 XgtMCL
Lead 40 ?g/L, 1/95, 3.3 XgtMCL
All concentrations above standards and
backgrounds. Dates range from 1992-94.
Not To Scale
13
Offsite Soil Contamination
Offsite Soil Contamination
Cesium-137 0.22- 0.39 pCi/g 1994 BBI,
2-3.5XgtBackground
Plutonium-238 0.19-0.22 pCi/g 1992 24mg/kg 1992
BBI 9.5-11XgtBackground
Arsenic 8.2mg/kg 1992 SMMC 21XgtRSSL
Arsenic 24mg/kg 1992 BBI 61.5XgtRSSL
Arsenic 1-3mg/kg 10/98 Las Virgenes
Creek 2-7XgtRSSL
Lead 383mg/kg 6/99 Bell Canyon
Residence 2.6XgtRSSL
Cesium-137 ND- 0.32 pCi/g 1/27/00 Ahmanson Ranch,
0.5 0-2.9XgtBackground
Beryllium 500-1000mg/kg 8/96 Bell Canyon
0.5-1.0 deep 3-6XgtRSSL
All above standards and backgrounds. Dates
range from 1992-94.
Not To Scale
14
Contamination Potential Soil GW Exposure
Locations
006-007
ETEC
003-005
Alfa
Bravo
Happy Valley
SDF
Canyon
Bowl
Delta
Coca
002
001
Water
Buffer
Latest NPDES permit provides for new NPDES
outlets in SE NE
Surface water
Groundwater
TCE Plume
LEGEND
Note Does not include air pathways.
15
TCE DOSE RATIOSfor Worst Case ScenariosExposure
to Contaminated Groundwater
NOTE Groundwater is a potable water source Avg.
lifetime dose range 1.2x10-4 - 1.1x10-2 mg/kg-d.
a order of magnitude ranges, 1994-1996 MCL
Maximum contaminant level drinking water
standard
16
Air Contaminant Concentration Estimation
3. Modeling CALPUFF - a multi-layer,
multi-species non-steady-state puff dispersion
model that simulates effects of time- and
space-varying meteorological conditions on
pollution transport, transformation and removal
Major HAPs benzene, 1,3-butadiene, methyl
chloroform, hydrazine, toluene, TCE, xylene,
arsenic, beryllium, cadmium, chromium, lead,
manganese, mercury, nickel, selenium
17
Average TCE Concentration from all RET Point
Sources

• Ground Level TCE ConcentrationsDue to Air
  Emissions
• Example Rocket Engine
  Testing (RET)

Average TCE Concentration from RET (1955-1990
(89 tons/yr))
18
Location of Receptor Communities used in Exposure
Analysis
COMMUNITIES 1. Bell Canyon 2. West Hills
3. Dayton Canyon 4. Woodland Hills 5.
Simi Valley 6. Chatsworth 7. Canoga Park 8.
Hidden Hills 9. Santa Susana Knolls 10.
Sage Ranch / Woolsey Canyon 11.
Brandeis-Bardin Inst.
9
9
19
Inhalation Dose Ratios (DR)for Worst Case
Scenarios

• Dose ratio (DR) (Lifetime average daily
  dose) / (Acceptable lifetime daily dose ALADD).
• Notes a. DRs are based on 19532004 air
  emission estimates max receptor concentrations
  derived from dispersion models
• and lifetime exposure scenarios
  for an adult male. The ALADDs to which exposure
  doses are compared are based
• on EPAs Chronic Inhalation
  Cancer Slope Factor (for 1 10-6 cancer risk).
• b. Hydrazine derivatives include
  hydrazine, and UDMH (unsymmetrical-dimethylhydrazi
  ne).

20
Offsite Areas of Exposure Concern
21
CONCLUSIONS

• Past Exposures
• During the most active years of SSFL (1953-1970s)
  there was potential for significant exposures to
  TCE and hydrazine -primarily within 1-2 km of
  SSFL.
• Present Exposures
• Due to offsite TCE groundwater contamination
  northeast of SSFL, and the presence of private
  groundwater wells in this area, utilization of
  these wells for domestic and agricultural use
  could have resulted in significant exposure to
  TCE and related degradation products.
• Exposure to offsite contaminated soil was
  significantly lower compared to exposure
  associated with groundwater and air pathways.
• There is potential for residential exposure to
  perchlorate (source yet to be identified) via
  direct or indirect exposure to groundwater in
  areas east of SSFL (Dayton Canyon, West Hills,
  Woolsey Canyon).

22
RECOMMENDATIONS

• There is a need for reliable monitoring of soil,
  ephemeral stream water and groundwater, surface
  water, and vegetation within 1-2 miles of SSFL.
• Given the level of groundwater contamination
  (e.g., TCE) and the presence of wells northeast
  of SSFL, an updated well-use survey should be
  conducted for areas northeast and east of SSFL
  (within 1 km) to assess private well use,
  contamination level and the potential for
  exposure.
• Groundwater wells in Ventura and Los Angeles
  Counties (within 3 miles of SSFL) should be
  regularly monitored for perchlorate, NDMA,
  1,4-dioxane and chromium.
• Future and ongoing construction activities at and
  in the vicinity of SSFL should be required to
  sample/monitor soil/sediment, groundwater, and
  resuspended dust.

23
Radionuclides

• Lack of adequate and comprehensive offsite
  radionuclide monitoring prevents community risk
  assessment.
• SSFL past sampling protocol (including sample
  locations analysis) were deficient and thus
  there is uncertainty regarding past offsite
  impacts.
• Proposed cleanup standards (prior to CA SB 990)
  were insufficient to meet the requirement of
  future potential unrestricted residential land
  use.
• According to EPA (2003), DOE cleanup levels for
  the ETEC site in Area IV could result in cancer
  risks exceeding the CERCLA risk range of 10-6 to
  3 10-4 risk from this dose limit may vary by
  an order of magnitude or more depending upon the
  radionuclide present and the selected land use.
• A comprehensive offsite monitoring of
  radionuclides is warranted
• This is due in part, but not only, to recent
  detections of tritium at levels as high as 83,000
  pCi/L in new groundwater wells (DOE Community
  Meeting, Simi Valley, 6/3/2004).

24
A SUCCESS STORY