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PUBLIC HEALTH ASSESSMENT

WESTINGHOUSE (SUNNYVALE PLANT)
SUNNYVALE, SANTA CLARA COUNTY, CALIFORNIA


ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

The tables in this section list the contaminants of concern at the Westinghouse site. However, their listing does not imply that a health threat exists. This health assessment will evaluate these contaminants in subsequent sections and will determine whether exposure to them has public health significance. ATSDR/CDHS selects the contaminants of concern based on the following factors: 1) concentrations of contaminants on and off the site; 2) field data quality, laboratory data quality, and sample design; 3) comparison of site-related concentrations with background concentrations; 4) comparison of site-related concentrations with health assessment comparison values for noncarcinogenic and carcinogenic endpoints and other appropriate values; and 5) community health concerns.

In the data tables that follow under the On-site Contamination subsection and the Off-site Contamination subsection, the listed contaminant does not mean that it will cause adverse health effects from the exposures. Instead the list indicates which contaminants will be evaluated further in the health assessment. When selected as a contaminant of concern in one medium, that contaminant will be reported in all media.

The data tables include the following acronyms:

* CREG = Cancer Risk Evaluation Guide
* EMEG = Environmental Media Evaluation Guide
* CA AL = California Action Level
* CA MCL = California Maximum Contaminant Level
* EPA MCLG = Environmental Protection Agency Maximum Contaminant Level Goal
* EPA MCL = Environmental Protection Agency Maximum Contaminant Level
* EPA PMCLG = Environmental Protection Agency Proposed Maximum Contaminant Level Goal
* ppm = parts per million (equivalent to milligram/kilogram [mg/kg])
* ug/L = microgram per liter (equivalent to parts per billion [ppb])
* RfD = Reference Dose

Concentrations of contaminants in specific media are compared with criteria guidelines, and the results are used to select contaminants for further evaluation. The comparison criteria values include EMEGs and CREGs developed by ATSDR, RfD and MCL/MCLG values developed by EPA, and MCL and Action Level values developed by CDHS. EMEGs are media specific values developed by ATSDR to serve as an aid in selecting environmental contaminants of concern that need to be further evaluated for potential health impacts. EMEGs do not consider carcinogenic effects. CREGs are estimated contaminant concentrations based on a one excess cancer in a million persons exposed over a lifetime. CREGs are calculated from EPA's cancer slope factor. EPA's RfD are estimates of the daily exposure to a contaminant that is unlikely to cause adverse health effects.(15)

EPA's Maximum Contaminant Level Goal (MCLG) is a drinking water health goal. These values include a margin of safety and represent a level where no known or anticipated adverse health effects should occur. Proposed Maximum Contaminant Level Goals (PMCLGs) are MCLGs that are being proposed. Maximum Contaminant Levels (MCLs) represent contaminant concentrations that EPA deems protective of public health (considering the availability and economics of water treatment technology) over a lifetime (70 years) at an exposure rate of 2 liters of water per day. While MCLs are regulatory concentrations, PMCLGs and MCLGs are not.(16,17)

For some chemicals, California has established its own MCL values, which are stricter than EPA's MCL values, and Action Levels (CA ALs) which are health-based criteria. Unlike the MCL's, CA ALs are not enforceable drinking water standards, but California uses them to strongly urge water purveyors to take corrective actions to reduce the level of contamination in the water they supply.(16,17)

Toxic Chemical Release Inventory (TRI) Search Information:

We conducted a search of the EPA Toxic Chemical Release Inventory (TRI) for the site and local area for the years 1987, 1988, and 1989 (the years for which TRI data were available on-line at the time this health assessment was written). The TRI contains information voluntarily submitted to the EPA on estimated annual releases of toxic chemicals to the environment from active industrial facilities.(11)

As provided in the 1987 TRI, Westinghouse reported releases to the environment of 70,900 pounds of methyl ethyl ketone and 46,546 pounds of 1,1,1-trichloroethane (1,1,1-TCA) from its Sunnyvale facility. For methyl ethyl ketone, the majority of the releases was listed as non-point air release or other off-site release (38,000 pounds listed as other, 23,000 pounds non-point air release) versus air (9,000 pounds) or water (900 pounds) released to a publicly owned treatment works. For 1,1,1 TCA, most of the release was listed as non-point air release (45,000 pounds). Non-point air releases may result from leaks from equipment, evaporative losses from surface impoundments, or from building ventilation systems.

In 1988, Westinghouse reported releases of 25,592 pounds of 1,1,1 TCA and 27,200 pounds of methyl ethyl ketone. The majority of the releases for these two chemicals was listed as non-point air releases (25,000 pounds of 1,1,1-TCA and 22,000 pounds of methyl ethyl ketone.

In 1989, no submissions were listed for the Westinghouse Sunnyvale facility.

A. ON-SITE CONTAMINATION

As described under Site Description and History, from 1981 to 1987, BCCE characterized previously existing on-site soil contamination. Soil removal actions occurred for all contaminated on-site areas except for the Reservoir 2 area in 1984, 1985, 1986, and 1989. BCCE also installed groundwater monitoring wells, but no regular groundwater monitoring program was initiated.(3)

EMCON collected the data presented in this subsection regarding the remaining contamination in the Reservoir 2 area as part of the work conducted for the Remedial Investigation/Feasibility Study from 1988 to 1991.

SOIL

Westinghouse has defined four point sources of contamination remaining in the Reservoir 2 area (see Figure 3): 1) the former mineral oil tanks and Inerteen tank which contained PCBs, TCB, and DCB, formerly located just south of Reservoir 2; 2) the underground piping running from the former Inerteen and mineral oil tanks to Building 21 which are still in place; 3) the 500 gallon gasoline tank formerly located just north of Reservoir 2; and 4) the 20,000 gallon fuel tank located southeast of Reservoir 2.(1)

From 1989-1990, EMCON conducted soil sampling and analysis to assess the extent of contamination and its migration. Deep soil samples were mainly taken from soil borings or soil taken from well borings, with concentrations of contaminants measured at different depths. Some shallow soil samples were taken at depths between six inches to five feet primarily in the gravel area around the former Inerteen tank area. No surface soil samples (less than or equal to 3" deep) were taken.(1)

Figure 3 shows the locations of the soil samples taken and Table 1 reports the contaminants and concentrations.

Figure 4 gives a simplified cross section of the Inerteen tank spill area showing PCB contamination in groundwater and soil. In general, the highest concentrations of contaminants were found near the source areas. Only PCB concentration levels found near the tank area exceeded health assessment comparison values.(1,11) No analyses for volatile organic compounds or metals in soil were done.(1)

Inerteen tank area:

Results of soil samples taken from well borings around Reservoir 2 showed that the highest concentrations of PCBs, TCB, and DCB exist at the former Inerteen storage tank area. Subsurface soil samples, taken from the well boring for monitoring well 38 (W38) at the location of the former Inerteen tank, had PCB 1260 concentrations ranging from 458 ppm to 8,050 ppm, with the highest level at 25 feet below ground surface (BGS). The samples from W38 were taken at depths ranging from 9 to 44.5 feet.(1)

From the sampling conducted, EMCON determined the distribution of soil containing PCBs at concentrations greater than 500 ppm to be primarily limited to the former Inerteen storage tank area, with the highest concentrations within a 25 foot radius of the former tank area. EMCON describes the distribution of PCBs below a depth of 4 feet BGS as resembling an inverted mushroom with a central core extending to 31 feet BGS (the approximate depth of the groundwater table), and a longer areal distribution of PCB contaminated soil extending below the water table.(1)

Three subsurface soil samples were taken at a depth of 6 inches next to and between the concrete supports which held the Inerteen tank. The samples showed PCB concentrations ranging from 42,000 ppm to 140,000 ppm. Additionally, three soil borings with subsurface soil samples taken at depths of 0.5 to 1 foot, 2.5 to 3.0 feet, and 4.0 to 4.5 feet BGS, showed PCB concentrations ranging from 32 to 25,300 ppm, TCB at non-detectable levels (less than 0.05 ppm) to 50 ppm, and DCB at non-detectable levels (less than 0.33 ppm) to 0.96 ppm. The highest concentrations appeared in the 0.5 to 1 foot depth.(1)

Inside Building 21, near an hydraulic sump where transformers were tested, soil samples were taken from a well boring at depths ranging from 2.2 to 45.5 feet, and analyzed for PCBs, TCB and DCB. A PCB concentration of 10.7 ppm was detected in the sample taken at a depth of 2.2 feet, but all other samples had non-detectable levels for PCBs, TCB, and DCB.(1)

Soil samples taken from the base of the A aquifer or the top of the A/B1 aquitard, through four monitoring wells (W36, W38, W46, W48) in the former Inerteen tank area were used to assess the extent of a dense sunken oily layer of material containing PCBs, TCB, and DCB. Accurate measurement of this dense oily layer has been difficult because it is not distributed uniformly on top of the aquitard. Rather than responding to the groundwater gradient, the dense layer sinks and migrates along the top of the aquitard, collecting in small depressions. Measurements from the base of the wells near the former tank and near the pipelines show the dense layer ranges in depth from 0.19 feet to 2.8 feet. Analyses of the soil show varying concentrations of PCBs, TCB, DCB, diesel fuel, phthalates, and semivolatile organic compounds.(1)

TABLE 1. RANGE OF CONTAMINANT CONCENTRATIONS IN ON-SITE SOIL SAMPLES(1)
1989-1990

Contaminant

Sample depth feet, BGS
Concentration Range, ppm Detection Ratio
(#Detect/#analyses)
Comparison Value
ppm
Source
Poylchlorinated
biphenyls (PCBs)(2)
0.5 - 5.5(3)
9 - 25
29 - 54
ND(4)-140,000
ND-8,050
ND-6,610
13/15
4/8
10/27
5
0.1
EMEG
CREG
Trichlorobenzene
(TCB) (Total)(5)
0.5 - 5.5(3)
9 - 25
29 - 54
ND-50
ND-1,200
ND-3,510
16/36
7/24
21/78
1,820
RfD
1,2-and 1,3-Dichlorobenzene
(DCB)
0.5 - 5.5(3)
9 - 25
29 - 54
ND-0.96
ND-10
ND-140
1/24
2/16
4/52
126,000
RfD
1,4 -Dichlorobenzene
(DCB)
0.5 - 5.5(3)
9 - 25
29 - 54
ND
ND-1.0
ND-46
0/12
1/8
2/26
10,000
58
EMEG(I)(6)
CREG
Gasoline 3 - 25 ND-79
1/7
None
None
Benzene 3 - 25 ND
0/7
30
48
EMEG(I)(6)
CREG
Toluene 3 - 25 ND
0/7
420,000
RfD
Jet fuel 3 - 25 ND-10,200
3/7
None
None
Diesel 3 - 25 ND-6,200
1/7
None
None

(1) Source for data = Reference 1
(2) PCB values indicate concentrations for PCB 1260; no other PCB isomers were detected.
(3) No samples were taken at less than 6 inches deep from surface
(4) ND = not-detected
(5) Includes 1,2,3-, 1,2,4- and 1,3,5-Trichlorobenzene (TCB)
(6) EMEG for Intermediate exposure; all other EMEG values are for chronic exposure unless otherwise noted.

Simplified Cross-Section of Spill Area at Westinghouse Facility Showing PCB Contamination in Soil and Groundwater
Figure 4. Simplified Cross-Section of Spill Area at Westinghouse Facility Showing PCB Contamination in Soil and Groundwater

Well 48 (W48), located 90 feet northeast of the former Inerteen tank contained 102 ppm PCBs and 3,940 ppm total TCB just above the A/B1 aquitard at a depth of 44 feet BGS. Monitoring wells 50 and 40, located north and south of W48, showed only trace amounts of PCBs and TCB in soil samples taken just above the A/B1 aquitard.(1)

Pipelines:

EMCON also conducted sampling of subsurface soils to depths of 10 feet BGS along the Inerteen and mineral oil pipelines. Seventy five soil samples were screened using laboratory procedures specified by the Kwik Skrene® Analytical Testing System which only reads as a composite concentration the chlorine concentration of each chlorine containing compound relative to PCBs. Seven confirmation samples analyzed by EPA Method 8080 generally verified the results of the screening analyses. Only eight samples out of the seventy five taken showed detectable concentrations ranging from 20 ppm to greater than 500 ppm. The highest PCB concentrations (greater than 500 ppm) were found near the former Inerteen tank location at sample depths of approximately 2 and 7 feet.(1)

500 gallon gasoline tank:

EMCON also analyzed soil from a well boring (W41) at 5 foot intervals to a depth of 25 feet near the former 500 gallon underground gasoline tank removed in 1986. Benzene, toluene, xylene, and ethylbenzene were not detected. However, EMCON stated in the Remedial Investigation report that some residual gasoline contaminated soil may remain in the area because gasoline has been detected in groundwater at 25 feet BGS. The original soil was excavated to a depth of 9.5 feet BGS. The lateral excavation was limited in order to preserve the structural integrity of nearby structures (Reservoir 2, Building 12A and two monitoring wells).(1)

20,000 gallon fuel tank:

No analyses for benzene, toluene, xylene, and ethylbenzene were done for soil or well borings near the remaining 20,000 gallon subsurface fuel tank south of Reservoir 2. Diesel fuel was detected at 130 to 10,200 ppm in samples taken at 20 to 29 feet BGS in soil boring 51 (SB51) located near the north end of the tank. Diesel fuel was also found at a concentration of 6200 ppm in a sample taken at 3 feet BGS in soil boring 17 (SB17) near the concrete pad.(1)

GROUNDWATER

EMCON installed 28 monitoring wells (23 A-aquifer and 5 B1-aquifer wells) during the remedial investigation from 1989 to 1990. Nine wells (7 A-aquifer and 2 B1-aquifer wells) are located off site. Groundwater samples were initially collected in May 1989 and from January and July 1990. Westinghouse implemented a quarterly groundwater monitoring program in July 1990 which includes sampling monitoring wells for PCBs, DCB, TCB, volatile organic compounds (VOC's), fuel hydrocarbons, benzene, toluene, xylene, and ethylbenzene. The data reviewed and presented below comes from the three sampling events.

Table 2 lists contaminants and their concentrations found in unfiltered samples taken from on-site monitoring wells by aquifer. Eight organic compounds were detected at levels exceeding health assessment comparison values, namely PCBs, TCB, 1,3-DCB, 1,2-DCB, 1,4-DCB, benzene, 1,2-DCA, and TCE. Figure 5 shows the estimated area of contaminated groundwater, or plumes and Figure 6 show the location of site related monitoring wells.

A-Aquifer

The A-aquifer extends from the water table (about 25 to 30 feet BGS) to a depth of about 46 feet BGS. The highest concentrations of PCBs, TCB and DCB in the A-aquifer appear to be related to their presence in soil or the dense sunken layer in the aquifer matrix. Spatial analysis of the data shows PCB concentrations at non-detectable levels (<0.05 to 0.1 ug/L) or below the EPA MCL of 0.5 ug/L to the east and west of Reservoir 2. The extent of PCBs to non-detectable levels has not yet been defined to the north and northeast of Reservoir 2. Levels of PCBs above the EPA MCL also exist under Building 21 where the transformers were formerly tested. Only levels of 1,4-DCB, but not 1,2-DCB or 1,3-DCB, exceeded health assessment comparison values. The frequency of detection was low for all three DCB isomers.(1,11,13)

Of the fuel hydrocarbons, levels of gasoline, benzene, toluene, xylene and ethylbenzene were highest near the source area north of Reservoir 2, but only benzene levels exceeded the California MCL of 1 ug/L. Although high levels of gasoline, diesel and jet fuel were also detected in samples taken near the source areas, no drinking water standards or action levels exist for these compounds.(1,13)

TABLE 2. RANGE OF CONTAMINANT CONCENTRATION IN ON-SITE GROUNDWATER MONITORING WELLS BY AQUIFER(1) 5/89 - 7/90

Contaminant Concentration Range, ug/L Aquifer Detection Ratio
#Detects
#Analysis
Comparison Value
ug/L
Source
Polychlorinated
biphenyls (PCBs)(2)
ND(3)- 5,690
ND - 2.0
A
B1
13/29
10/16
0
0.5
EPA MCLG
EPA MCL
Trichlorobenzene
(TCB) (Total)(4)
ND - 11,238
ND - 0.21
A
B1
9/29
1/16
9 EPA MCLG
(for 1,2,4 TCB)
1,3-and 1,2-Dichlorobenzene (DCB) ND - 158
ND
A
B1
3/29
0/16
130 CA Action Level
1,4 Dichlorobenzene (DCB) ND - 110
ND
A
B1
3/29
0/16
5 CA MCL
Gasoline ND - 6800
ND
A
B1
4/32
0/6
  None
Benzene ND - 800
ND
A
B1
4/31
0/5
1 CA MCL
Toluene ND - 98
ND
A
B1
4/31
0/5
100 CA Action Level
Xylene ND - 210
ND - 8
A
B1
5/31
1/5
1750 CA MCL
Ethylbenzene ND - 540
ND - 11
A
B1
8/31
1/5
680 CA MCL
Diesel fuel ND - 17,000
ND
A
B1
1/6
0/1
None None
Jet Fuel 6,200
6,200
A
B1
1/6
1/1
None None
1,2 Dichloroethane
(DCA)
ND - 84
ND
A
B1
5/38
0/8
0.5 CA MCL
Trichloroethylene (TCE) ND - 55
ND
A
B1
4/38
0/8
5 CA MCL

(1) Source of data = Reference 1
(2) PCB values indicate concentrations for PCB 1260; no other PCB isomers detected.
(3) ND - not detected
(4) Includes 1,2,3-,1,2,4- and 1,3,5-Trichlorobenzene (TCB)

Estimated Contours of Contaminated Ground Water Plumes
Figure 5. Estimated Contours of Contaminated Ground Water Plumes

Location of Site Monitoring Wells
Figure 6. Location of Site Monitoring Wells

In contrast to the sunken dense layer containing PCBs and TCB described previously, a floating layer exists on top of the groundwater. This floating layer moves in the same direction as the groundwater and can be controlled and removed through groundwater pumping or bailing. Laboratory analyses of samples of the floating layer taken from wells show no benzene, toluene, xylene or ethylbenzene, but suggest the material is degraded residual of mineral oil or hydrocarbon fuel such as jet or diesel fuel.(1)

Groundwater samples from eight monitoring wells located near Building 21 north of Reservoir 2 showed the presence of one or more volatile organic compounds (VOCs). Table 2 shows that of the eight compounds identified, trichloroethylene (TCE) exceeded the CA MCL of 5 ug/L and 1,2-dichloroethane (1,2-DCA) exceeded the CA MCL of 0.5 ug/L.(1,13)

Groundwater samples from four monitoring wells also showed the presence of two semivolatile organic compounds (SVOCs), phenol (5 ug/L) and naphthalene (20 ug/L) in one well located near the former 500 gallon gasoline tank. These two compounds may be related to gasoline.(1) No federal or state drinking water standards exist for these compounds, although California has an Action Level of 5 ug/L for phenol to control undesirable taste and odor quality of water.(13) These two compounds will not be addressed further in the health assessment.

Groundwater samples from four monitoring wells (W39, W41, W42, and W44) were also analyzed for 26 dissolved metals. Although one sample reportedly exceeded local background values for arsenic, none of the samples exceeded California MCL values.(1,13) Metals will not be addressed further in the health assessment.

B-Aquifer

A data gap exists regarding the extent of contamination in the B1-aquifer. Only 7 on-site B1-aquifer monitoring wells are currently sampled regularly. PCB concentrations ranging from non-detectable to 2.0 ug/L have been detected in four on-site wells located in the approximate downgradient groundwater flow direction (north-northeast) from the area known to contain the dense sunken layer at the top of the A/B1 aquitard at the southern end of Reservoir 2. EMCON states that there is insufficient information to characterize the extent of PCB contamination downgradient in the B1-aquifer and additional monitoring wells will be installed during the remedial design to obtain this information.(1)

All other contaminants tested for in the B1 aquifer were either not detected or were not at levels exceeding health assessment comparison values.(1,15,17)

The presence of contaminants in the B1-aquifer may be a result of cross contamination between the A- and B1-aquifers through poorly sealed deep soil and well borings drilled in 1981 and 1982 by Westinghouse's previous contractor, BCCE. Two wells were decommissioned as a result of improper construction. One of these wells, W16, existed next to the former Inerteen tank and represented a way for contaminants to reach the B1-aquifer due to its construction.(1)

Contaminants can also have reached the B1-aquifer through direct vertical migration of groundwater through the A/B1 aquitard. Some wells show both PCB and jet fuel contamination, suggesting also that the jet fuel may somehow facilitate transport of PCBs through the aquitard.(1)

B. OFF-SITE CONTAMINATION

Soil

As described earlier, in 1981 BCCE characterized previously existing off-site soil contamination found in residential yards bordering the western perimeter fenceline. In their review of the 1981 data, Tetra Tech reported that BCCE had taken 77 soil samples from off-site properties at a depth of 0 to 6", and at distances 2, 5, and 10 feet from the western fence. All samples reportedly had PCB 1260 concentrations below 50 ppm. Of the 69 samples with detectable concentrations, 48 had less than 1 ppm. In 1984, Westinghouse removed PCB contaminated soil in off-site residential areas to a depth of at least 2.0 feet, until PCB levels reached a nondetectable level (less than 0.5 ppm).(3)

In a 1984 draft memo to the CDHS Toxic Substances Control Division (now known as Cal EPA Department of Toxic Substances Control) from the CDHS Epidemiological Studies Section (now known as CDHS Environmental Epidemiology and Toxicology Program), data was presented to show off-site soil samples were taken at 2, 3 and 5 foot distances from the western fence. The memo reported that a total of 60 samples were taken, 57 of which had detectable concentrations. Concentrations ranged from non-detectable to 27 ppm.(18)

For the current remedial investigation, EMCON analyzed soil from well borings for four off-site monitoring wells at depths ranging from 41 feet to 54 feet BGS. Samples showed non-detectable levels (less than 0.1 ppm) for PCBs, TCB, and DCB. No analyses were conducted for fuel hydrocarbons or other contaminants.(1)

Groundwater

Nine off-site monitoring wells (seven A-aquifer, two B1-aquifer) exist along Fair Oaks Avenue and Kifer Road, east and northeast of the site.

Table 3 lists the contaminants detected in off-site groundwater monitoring wells by aquifer. No analyses occurred for diesel fuel or jet fuel in off-site wells. Results of groundwater samples taken in the off-site downgradient (north-northeast) monitoring wells show PCB contamination in both the A and B1 aquifers in one or more groundwater sampling events. Neither TCB nor DCB have been detected.(1)

The B1 aquifer groundwater samples taken from the most downgradient well (W61) contained the highest off-site PCB concentration (3.3 ug/L) detected to date, and also contained high gasoline concentrations (19,000 ug/L) and varying concentrations of toluene, xylene, and ethylbenzene. The association of gasoline with the PCB concentration suggests there may be different transport mechanisms operating to facilitate movement of contaminants.(1) According to the EPA Record of Decision signed on October 16, 1991, the source of gasoline and related compounds in Well 61 may be related to an upgradient source east of Fair Oaks Avenue on property next to the Westinghouse site. The San Francisco Regional Water Quality Control Board which administers the Underground Storage Tank Program is currently investigating this potential source.

TABLE 3. RANGE OF CONTAMINANT CONCENTRATIONS IN OFF-SITE GROUNDWATER MONITORING WELLS BY AQUIFER(1)
5/89 - 7/90

Contaminant Concentration Range ug/L Aquifer Detection Ratio
(#Detects/
#Analyses)
Comparison Value
ug/L
Source
Polychlorinated
biphenyls (PCBs)(2)
ND(3)-0.5
ND-3.3
A
B1
5/11
4/6
0.5
EPA-MCL
Trichlorobenzene
(TCB)
ND
ND
A
B1
0/11
0/6
9
EPA-PMCLG
(for 1,2,4 TCB)
1,3- and 1,2-Dichlorobenzene (DCB)
ND
ND
A
B1
0/11
0/6
130
CA Action Level
1,4-Dichlorobenzene (DCB)
ND
ND
A
B1
0/11
0/6
5
CA MCL
Gasoline
ND
ND-19,000
A
B1
0/2
1/1
None
None
Benzene
ND
ND
A
B1
0/2
0/2
1
CA MCL
Toluene
ND
18-24
A
B1
0/2
2/2
100
CA Action
Level
Xylene
ND
97O-987
A
B1
0/2
2/2
1750
CA MCL
Ethylbenzene
ND
294-330
A
B1
0/2
2/2
680
CA MCL

(1) Source of data = Reference 1
(2) PCB values indicate concentrations for PCB 1260; no other PCB isomers were detected.
(3) ND = not-detected

A data gap exists with respect to being able to characterize the extent of off-site ground water contamination. Westinghouse plans to install additional monitoring wells during the remedial design phase to further define the extent of off-site contamination.

C. DATA QUALITY ASSURANCE AND QUALITY CONTROL

We obtained from EPA a field audit of quarterly groundwater monitoring activities and a Quality Assurance/Quality Control (QA/QC) summary for soil and groundwater samples conducted by EMCON. The overall assessment of the QA/QC summary indicated all data reviewed were acceptable for use. The review documented acceptable procedures and protocols were followed with regard to chain-of-custody, laboratory procedures, and data reporting.(19,20)

EMCON states in the Remedial Investigation that EPA has validated all soil samples collected from depths of 5 to 55 feet, but none of the samples collected from surface to 4 feet BGS were validated. However, the same contract labs and EPA methods were utilized.

Also none of the data collected by BCCE underwent an independent review for data validation.

D. PHYSICAL AND OTHER HAZARDS

During the site visit, we noticed an extensive amount of heavy machinery and some physical hazards, such as broken glass and nails in some areas of the site. The site has restricted access and there are safety signs posted throughout the site. The general public would not generally be affected by the physical hazards present on-site.


PATHWAY ANALYSES

To determine whether nearby residents are exposed to contaminants migrating from the site, CDHS/ATSDR evaluates the environmental and human components that lead to human exposure. This pathways analysis consists of five elements: a source of contamination; transport through an environmental medium; a point of exposure; a route of human exposure; and an exposed population.

CDHS/ATSDR identifies exposure pathways as completed, potential or eliminated. A completed pathway occurs when the five elements exist and indicate that exposure to a contaminant has occurred in the past, is currently occurring, or will occur in the future. A potential pathway exists when one or more of the five elements is missing, but could exist. Completed and potential pathways may also be eliminated when they are unlikely to exist. Table 4 identifies the completed exposure pathways, and Table 5 identifies potential exposure pathways. The discussion that follows the tables incorporates only those pathways that are important and relevant to the site. We also discuss some of the exposure pathways that have been eliminated.

A. COMPLETED EXPOSURE PATHWAYS

Soil Exposure to Off-Site Residences Pathway

Past exposure of residents was possible from contaminated surface and subsurface soils in residential yards bordering the western perimeter fenceline of the Westinghouse site due to the spraying of PCB containing fluids for weed control. Westinghouse removed contaminated soil from off-site residential and business yards bordering the western perimeter fenceline in 1984.(1,3)

Past migration of contaminated soil could have occurred by wind, surface run-off, and fugitive dust from vehicular traffic. Residential and business yards bordering the western fenceline represent the closest point of exposure. Two apartment buildings (total of 48 units), about 12 houses, and two businesses border the western fenceline.

Since PCBs strongly adsorb to soil, the greatest exposure may be at or near the surface.(21) Skin contact, inhalation of soil dust, and incidental soil ingestion represent likely routes of exposure for residents to contaminated soil. Incidental soil ingestion occurs if a person eats, drinks, smoke or participates in recreational or occupational activities near soil containing contaminants. For residential yards and recreational areas such as parks, soil ingestion may be an important route of exposure, especially for children less than 6 years of age.(22) Soil ingestion is greater for young children because of their greater hand-to-mouth activity. Young children typically ingest 200 milligrams (mg) soil per day while adults and older children ingest less than 100 mg per day. Activities such as gardening could lead to exposure to soil contaminants. However, given that PCBs are not very water soluble, plant uptake would be minimal and thus ingestion of fruits or vegetables grown in contaminated soil would probably not represent a significant exposure route.(23)

TABLE 4. COMPLETED EXPOSURE PATHWAYS

Completed Exposure Pathway Time Component Source of Contamination Environmental Media and Transport Point of Exposure Route of Exposure Receptor Population
Soil Exposure to Off-site Residences Past Spraying of PCB containing fluids along fencelines Surface and subsurface soil

Air

Residential and business yards Incidental ingestion

Inhalation

Skin contact

Residents and business bordering Westinghouse fencelines
Soil Exposure to On-site Workers Past
Present
Future
Storage and handling of PCB containing fluids

Spraying of PCB containing fluids along fencelines

Leaking Inerteen tank and pipelines near Reservoir 2

Leaking fuel tanks

Surface and Subsurface soil

Air

On-site areas

Bldg. 21

Reservoir 2 area

Incidental ingestion

Inhalation

Skin contact

On-site workers (surface and subsurface)


TABLE 5. POTENTIAL EXPOSURE PATHWAYS

Potential Exposure Pathway Time Component Source of Contamination Environmental Media and Transportation Point of Exposure Route of Exposure Receptor Population
Soil Exposure to Future on-site Residential Development
Future
Leaking Inerteen tanks and pipelines

Leaking fuel storage tanks

Surface and subsurface soil Residences developed on-site Ingestion

Inhalation

Skin contact

Future residents of on-site homes
Groundwater Exposure to Future Well Users
Future
Contaminated groundwater Groundwater Future water supply wells Inhalation

Ingestion

Skin contact

Future well users

Information available from BCCE's investigations and an internal CDHS memo regarding off-site contamination indicate the presence of PCBs in off-site soil samples (see previous Off-site Soil Contamination Section).(1,3,18) None of the data collected by BCCE received a quality assurance review. Nevertheless, the limited information available allows exposure of neighboring residents to be considered further under the Public Health Implications Section of this health assessment.

Some amount of contaminated soil may also have been air borne and deposited in nearby areas, such as the park located about 200 feet from the northwest corner of the site and in residential yards located across the street from the site. No data, such as soil dust in ambient air or soil concentrations from the park or other nearby residential yards, or modeling information is available to allow adequate assessment of these possible exposures pathways.

Soil Exposure to On-Site Workers Pathway

Although Westinghouse discontinued using PCBs in the mid-1960's, past, present, and future exposure pathways are possible for on-site workers from contamination of surface and subsurface soils at several points of exposure on-site. Workers who walked the grounds to spray the PCB containing fluids in on-site areas for weed control and workers who handled PCB containing fluids in the Building 21 and Reservoir 2 area probably experienced the highest exposure due to their occupational activities. Workers who came into contact with other heavily contaminated areas, such as the northwest yard, may also have experienced exposure through skin contact, incidental soil ingestion, and inhalation. Since no data exists to assess level of exposure from these routes, we can not adequately assess the effect of past exposure to workers. However, worker concerns are addressed below under the section titled Public Health Implications.

With present site conditions, the greatest soil contamination exists near the former Inerteen tank area and the underground pipeline south of Reservoir 2. Present exposure of on-site workers to the contaminated soil by way of incidental soil ingestion, inhalation or dermal contact is minimal for those workers who spend most of their work hours indoors. Presently about 300 employees work in the general vicinity of Reservoir 2 and Building 21.

PCB contamination was detected in soil under Building 21. However, present exposure to workers within the building is probably minimal since the building has a concrete floor. Future exposure may be possible if the building is removed due to a change in land use. Removal of contaminated soil under Building 21 is not included in the proposed remediation. If a change in land use occurs, efforts to minimize future exposure to on-site workers should be undertaken.

For those performing outdoor related activities, exposure to on-site soil contaminants is still limited because the former tank area is surrounded by a fence and covered with gravel. Exposure for the on-site workers mentioned above will not be assessed further in this health assessment.

Presently, exposure through inhalation, incidental ingestion and skin contact is likely to occur for on-site workers who engage in subsurface construction such as installation or maintenance of underground utilities. Future exposure will be unlikely given the proposed remediation plan involving excavation to eight feet of all soil in the affected Reservoir 2 area containing PCB contamination above 25 ppm, replacement with clean fill, and covering with asphalt.(1)

Additionally, remediation workers who will be involved with proposed future soil removal activities are likely to be exposed to contaminated soil through ingestion, inhalation, and dermal contact. Future exposure to these workers could be eliminated if they wear appropriate personal protective equipment and comply with applicable health and safety guidelines. Exposure of both on-site subsurface and remediation workers will not be considered further.

Present exposure of nearby residents to on-site contaminated soil is not an environmental pathway of concern. Minimal, if any, exposure occurs to residents living near the contaminated soil in the former tank area. The closest residence is approximately 500 feet from the affected area, access to the entire site is secured, and the Reservoir 2 area itself is fenced off. Since the ground surface is paved with asphalt or concrete or covered with gravel, soil probably is not blown or washed off the site. Under future remediation activities, appropriate measures taken to contain soil and fugitive dust to the immediate area will prevent exposure of nearby residents to on-site contaminated soil. This exposure pathway will not be considered further.

Exposure to the dense sunken layer containing site related contaminants lying on top of the A/B1 aquitard is considered in the Groundwater Exposure to Future Well Users Pathway.

B. POTENTIAL EXPOSURE PATHWAYS

Soil Exposure to Future On-site Residents

Future use of the site for residential development could lead to exposure to contaminated on-site surface and subsurface soils. The soil removal action in 1984 and 1985 only removed contaminated on-site soil to a depth of 6 inches. Residential development is unlikely to occur at this site which has been used only for industrial purposes for the last 85 years. However the City of Sunnyvale is currently conducting an Environmental Impact Report of the site to assess it for future residential development. EPA has informed the City of Sunnyvale that the site is unsuitable for future development due to the extent of contamination and proposed treatment.(24) Implementation and adherence to strict deed restrictions will minimize exposure to future on-site residents. Exposure from this pathway will not be considered further.

Groundwater Exposure to Future Well Users Pathway

No known past municipal or agricultural use of site contaminated groundwater has occurred, nor is there present use occurring. Present and/or future use of on-site and off-site groundwater from the shallow A- and B1-aquifers could lead to exposure to contaminated groundwater. Concentrations of several site-related chemicals in groundwater (see Tables 2 and 3) are at levels that would be of potential public health concern if domestic use of contaminated groundwater occurred.

Currently available data is insufficient to fully characterize the extent of the off-site contaminated plume in both the A- and B1-aquifers. However, no private or municipal wells or other production wells are located within 2000 feet of the site. An industrial supply well located at the Westinghouse site is not used. Water for municipal use is available from other aquifers having higher quality water and water yield. Regulatory barriers also exist which prohibit installation of shallow private wells.

Additional monitoring wells to further define the extent of groundwater contamination is needed. Proper well construction will prevent the likelihood of vertical migration of contaminants into deeper aquifers.

The proposed extraction and treatment system for contaminated groundwater will be designed to clean up off-site groundwater to below levels of health concern and to prevent further migration of on-site contaminants to off-site areas. However, for on-site contaminated groundwater, the PCB standard will not be able to be met because no feasible technology exists to allow for removal of the dense sunken layer containing PCBs and TCB lying on top of the A/B1 aquitard. More extensive characterization of the A/B1 aquitard to further assess the nature and extent of the dense sunken layer containing PCBs and TCB is warranted. Institutional controls will prevent construction of water supply wells in the contaminated area and prevent any possible future exposure to contaminated groundwater. Exposure from this pathway will not be considered further.


PUBLIC HEALTH IMPLICATIONS

A. TOXICOLOGICAL EVALUATION

In this section we will discuss the health effects in persons exposed to specific contaminants, evaluate state and local health databases, and address specific community health concerns. To evaluate health effects, ATSDR has developed a Minimal Risk Level (MRL) for contaminants commonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to a contaminant, below which non-cancer, adverse health effects are unlikely to occur. When there is adequate information from animal or human studies, MRLs are developed for each route of exposure, such as ingestion and inhalation, and for the length of exposure, such as acute (less than 14 days), intermediate (15-364 days), and chronic (greater than 365 days). ATSDR presents these MRLs in publications known as Toxicological Profiles. These chemical-specific profiles provide information on health effects, environmental transport, human exposure, and regulatory status. In the following discussion, we used the 1989 ATSDR Toxicological Profile for Selected PCBs (Polychlorinated Biphenyls).(21)

For the Westinghouse Sunnyvale site, existing information and data show that PCB exposure through soil represents a completed exposure pathway that may present a public health concern.

Polychlorinated Biphenyls (PCBs)

Exposure to PCBs probably occurred for some residents living next to the western perimeter fenceline of the Westinghouse Sunnyvale site due to the presence of contaminated soil in their yards. Westinghouse's contractor, BCCE, confirmed the presence of contaminated soil in residential yards in 1981; IT Corporation removed the soil in 1984. Incomplete data for the off-site contamination appears in the earlier site characterization information prepared by BCCE, and EPA confirms that no data validation occurred for the earlier data. A draft CDHS memo listed off-site contamination data from residential yards. We used this data to estimate the exposure that neighboring residents may have experienced through inhalation, incidental ingestion, and skin contact. Skin contact and soil ingestion, especially for children, would be considered the main routes of exposure at nonrestricted residential sites.

Residents living along the western fenceline of the Westinghouse site may have been exposed for up to 30 years to low levels of PCBs by gardening or playing in the yards. We assume young children eat about 200 milligrams of soil per day through normal hand and mouth activities and weigh 16 kg (35 pounds). We assume adults have an incidental soil ingestion rate of 50 to 100 milligrams of soil per day and weigh 70 kg (154 pounds). We also assume exposure occurs every day (365 days/year).

Using the highest soil contamination levels detected in a neighboring yard and the above assumptions, the level of exposure that either a child or an adult might have experienced by incidental ingestion of contaminated soil does not exceed ATSDR's proposed ingestion MRL for chronic exposure. As described below, health effects have been observed at much higher levels of exposure.

ATSDR is currently updating the Toxicological Profile for PCBs and is proposing an MRL of 0.000005 mg/kg body weight/day chronic exposure to PCBs.(25) Usually, when a chronic MRL is not available, we use EPA's Reference Dose (RfD). Similar to an MRL, an RfD is an estimate of daily human exposure to a contaminant for a lifetime, below which non-cancer health effects are unlikely to occur. However, EPA has not developed a chronic RfD for PCBs. Inhalation and skin contact may also have increased exposure of off-site residences, but no MRLs or RfDs currently exist for these routes of exposure either.

As an environmental contaminant, the abbreviation PCBs refers to a group of chemical compounds known as polychlorinated biphenyls. PCB compounds are very persistent chemicals which tend to accumulate in the environment and show a wide distribution throughout the entire environment. Human exposure usually results from environmental or occupation exposures.(21)

PCB compounds enter the body through contaminated food and air and through skin contact. The most common route of exposure is by eating fish and shellfish from PCB contaminated water; this route does not exist at the Westinghouse site. Usually exposure from drinking water is minimal. For the Westinghouse site, although PCBs appear in the shallow groundwater at high levels, this water is not presently used for drinking water purposes, nor is future use considered very likely.

The past exposure to residents occurred at levels much lower than levels known in certain past occupational settings. Animal experiments have shown that some PCB mixtures produce adverse health effects that include liver damage, skin irritations, reproductive and developmental effects, and cancer.(21)

Human studies to date show that irritations, such as acnelike lesions and rashes, known as chloracne, can occur in PCB exposed individuals. Skin irritations have been noted in workers where the air contained more than 0.01 mg PCBs per cubic meter of air for more than 14 days. Health effects observed in humans from skin contact include skin irritation and liver effects, but doses are not known. Other occupational exposure studies suggest that PCBs might cause liver cancer. Reproductive and developmental effects have also been observed in some occupational studies and women eating contaminated fish.(21) People with impaired liver function, or who take medications that might affect the liver, may be more sensitive to PCBs.(23)

Based on evidence that PCBs cause cancer in animals, EPA considers PCBs to be a probable cancer-causing chemical in humans. EPA estimates that ingestion of 1 microgram of PCBs per kilogram of body weight per day over a lifetime of 70 years would result in 77 additional cases of cancer in a population of 10,000 people or 7,700 additional cases in a population of 1,000,000 (one million) people. These risk values are plausible upper limit estimates; actual risk levels are probably lower.(21)

For residents who may have been exposed to PCB contaminated soil in their backyards, the level of exposure probably was much lower than that used in EPA's estimate. In addition, their exposure was not for a lifetime. Based on the available sampling information, we estimate persons exposed to the contaminated soil in their yards may have a low increased risk of developing cancer over a lifetime from the estimated maximum 30 year exposure period which may have existed prior to the removal of the contaminated soil.

Workers at the Westinghouse Sunnyvale site also experienced past exposure to PCB contamination by way of handling PCB containing fluids or by coming into contact with PCB contaminated soil. Their level of exposure may have been higher as compared to residents. There is insufficient information contained in the documents we have reviewed to allow an adequate assessment of the past exposure workers may have received as a result of their occupational activities. Review of information such as employee health records or worksite environmental monitoring data may be warranted; such information was not available in the documents we reviewed. We have requested this information from Westinghouse, but it was not provided. With appropriate estimates of contaminant exposures at points of human exposure, the likelihood of noncarcinogenic and/or carcinogenic health effects occurring can be assessed.

B. HEALTH OUTCOME DATA EVALUATION

Given that a past complete exposure pathway existed for both off-site residences and on-site workers, review of relevant health data bases is appropriate to determine whether health impacts may have occurred as a result of the exposure. Also some of the community concerns expressed focus on health issues. Health data that may be relevant to the Westinghouse Sunnyvale site include data from the Cancer Surveillance Program, the California Birth Defects Monitoring Program, and data that may be available from Westinghouse's health and safety program.

As discussed under the section on Health Outcome Data, the Cancer Surveillance Program began collecting data for the region that includes the Westinghouse Sunnyvale site in 1988. Data for 1988 and 1989 were preliminarily released in 1991.(10) This cancer incidence information may ultimately be useful in a future cancer investigation, but with only two years of data, it should be viewed carefully since background cancer rates for that population are undefined and the first year of cancer reporting usually results in under reporting. Additionally, due to the long biological lag time, or latency period, from exposure to cancer development, and the inability to attribute specific exposures to individual cancer cases, the cancer incidence for 1988 or 1989 may not reflect effects of exposure originating from the Westinghouse Sunnyvale site.

Information obtained from the Cancer Surveillance Program shows that for both 1988 and 1989, there were a total of 31 cancer cases for each year coded to four census tracts located closest to the Westinghouse site. The five most common cancers in the overall general population are lung, breast, colorectal, prostate, and bladder. The cases reported to by the Cancer Surveillance Program for the four census tracts reflect the normal distribution of cancer cases in the general population. The reported cases largely reflect the size and age structure of these tracts, but until data is available from the 1990 census by race, sex, and age at the tract level, meaningful incidence rates can not be calculated and compared to county, state or national rates. Additionally the potentially exposed off-site population is small enough such that no increase in cancer that might be due to site contamination would be able to be detected.

We requested information from Westinghouse regarding medical and health services available to their employees from their medical clinic. The Manager of Health, and Safety and Environmental Affairs provided the following information through a letter dated August 15, 1991:

"Several months after PCB's were identified in 1981 on Westinghouse property, a number of employees and retirees requested health evaluations related to possible PCB exposure. Evaluations were performed on thirty-nine individuals. The health evaluations included liver and blood analysis for possible PCB contaminates. All liver function studies were within normal range. Blood analysis were completed with equipment that allows identification of PCB's in the blood at levels greater than 0.2 MCG/100 ML. There were no measurable amounts of PCB's in any of the blood analysis."

Upon receipt of the letter, we requested additional clarifying information as described in the previous section. When we receive it, we will review it.

C. COMMUNITY HEALTH CONCERNS EVALUATION

A number of people attending either the August 7, 1991 EPA meeting, or the August 21, 1991 or October 17, 1991 neighborhood meetings have raised some health related concerns. Prior to those meetings, no community health concerns were raised to us directly except from one resident we met during our visit to the neighborhood on July 10, 1991 who asked about possible contamination in the drinking water. We assured the individual that the contamination was not affecting the drinking water at all because the City of Sunnyvale did not secure drinking water for the people in that area from groundwater, but rather from other sources. For questions 1 to 14 below, we provide the following responses to the health related issues raised at the August or October meetings.

CDHS released the health assessment for public comment from April 29, 1982 to June 1, 1992 and held a public meeting on May 18, 1992 at Murphy Park, Sunnyvale. Approximately 25 people attended. Questions 15 to 20 reflect the health related issues expressed during the June meeting and the public comments received.

  1. What health effects are possible if you are exposed to PCBs?
  2. Long-term occupational exposure to low levels of PCBs have been shown to cause; a) severe, persistence skin eruptions called chloracne, b) liver damage that could include weight loss, nausea, vomiting, jaundice and abdominal pain. PCB exposure has also been associated with reproductive problems and birth defects in animals and decreased birth weight in infants born to mothers exposed during pregnancy. Some PCBs are considered probable human carcinogens because they cause liver tumors in rats and mice.

  3. Do the PCBs affect fruits and gardens in the neighborhood?
  4. There is no evidence to suggest that fruits and vegetables grown near the Westinghouse site are contaminated with PCBs. Currently the contaminated soil is covered and not able to migrate. Most edible plants do not have roots that would reach down 70 feet through the shallower A aquifer to the contaminated groundwater in the B1 aquifer where it appears off-site. Plant uptake is probably minimal since PCBs are not very water soluble.

  5. Are there health effects from taking a shower in PCB-contaminated water?
  6. Health effects could occur from taking showers with PCB contaminated water, depending on the levels present and how often someone used contaminated water. However, the contaminated groundwater at the Westinghouse site is not used for domestic purposes and no future use is likely. If people did shower with PCB contaminated water, they could inhale PCB vapors and absorb PCB through skin contact also. Animal studies have shown skin, liver, and kidney damage when high levels were applied to skin or when the animals breathed high levels in the air. It is not known if the same effects could happen in people if they were exposed the same way.

  7. What is the danger of PCB exposure to the workers at Westinghouse?
  8. Present exposure of on-site workers to the PCB-contaminated soil by way of incidental ingestion, inhalation or skin contact is minimal for those workers who spend most of their work hours indoors. Although PCB contamination was detected in soil under Building 21, present exposure to workers within the building is probably minimal since the building has a concrete floor. For workers performing outdoor activities, exposure to the highest on-site soil contamination near the former Inerteen tank and the underground pipelines south of Reservoir 2 is limited because the former tank area is surrounded by a fence and covered with gravel. Present exposure through inhalation, incidental ingestion and skin contact is likely to occur for workers who engage in subsurface construction such as maintenance of underground utilities. Future exposure will be unlikely since the remediation plan calls for excavation to eight feet of all the PCB contamination above 2 ppm in the affected area.

    For past exposure, workers who sprayed PCB containing fluid in on-site areas for weed control and workers who handled PCB containing fluids in Building 21 and Reservoir 2 area probably experienced the highest exposure due to their occupational activities. Since no data exists to assess the level of exposure from these routes, the effect of past exposure to workers can not be adequately assessed.

  9. What health studies have been done on the residents and the workers?
  10. To date no specific health effects studies of PCB exposure have been done on the residents. The Health and Safety Manager at Westinghouse informed CDHS/ATSDR that in 1981, health evaluations were performed on 39 individuals, (with employees or retirees), which included liver and blood analyses for PCB contaminants. Findings for all liver function studies and blood analyses were reportedly normal. CDHS is requesting further data from Westinghouse.

  11. When will a health study be done on the residents and the workers?
  12. CDHS/ATSDR staff consider this site a public health hazard based on past exposure to PCBs that residents and workers may have experienced. Additional information about past exposure is necessary to assess the likelihood of adverse health effects on community or employee health. Present and future exposure is unlikely if planned remediation occurs and deed restrictions are implemented and adhered to. Based on the current levels of exposure, it is unlikely that a health study would be recommended at this time. However, if additional information about PCB-related health effects and exposure become available, the need for a health study can be re-evaluated.

  13. Was there testing done in soils outside the Westinghouse site?
  14. As described previously in this health assessment, in 1981 there was soil testing done on samples take from residential backyards along the western fenceline of the Westinghouse property. Soil samples have not been taken from other off-site areas.

  15. Have PCBs spread off-site in the groundwater? Is the plume spreading in the area of Cedar and Dwight? Have the exact boundaries of the plume been defined?
  16. Yes, PCBs have spread off-site in the groundwater (B1-aquifer). EPA estimates the plume is spreading in the direction of Cedar and Dwight at the speed of about one to two feet a year. The boundaries of the plume have not yet been defined because the monitoring wells are not yet in place. During the next phase of site activities, EPA will require further groundwater testing to complete the final definition of the plume.

  17. What is the general air quality around the site? Are there PCBs in the air?
  18. Westinghouse has a permit from the Bay Area Air Quality Management District to cover current air emissions from operations at the site. This permit requires that the air emissions from the facility be within the limits applicable under state and federal law. Air monitoring of the current operations is not considered part of the Superfund clean-up process. There are no known current air releases of PCBs from Westinghouse. Air monitoring will occur routinely during investigation and clean-up when required by health and safety procedures. The short term risks will mainly affect the workers who should wear appropriate protective clothing.

  19. During excavation, what type of precautions will be taken to prevent soil particles from becoming airborne and being carried downwind into the neighborhoods?
  20. EPA requires a health and safety plan to be developed as part of any removed actions. This plan will include appropriate measures be taken to prevent exposure of nearby residents to on-site contaminated soil during the removed processes. These measures may include actions such as spraying water on the dirt to keep it from blowing. Remediation workers will be required to wear protective clothing and equipment.

  21. Can the soil under Building 21 be tested now?
  22. Yes, it is possible to perform some limited testing of the soil under Building 21. In fact, some soil samples were taken when the monitoring wells were installed. This limited testing showed only minor amounts of PCBs under Building 21. It would be technically difficult to more thoroughly assess the soil under building without serious disruption to the ongoing operations. However, because there is uncertainty about the soil under the building, the Record of Decision (ROD) requires that if the building is ever abandoned or demolished, EPA must be notified.

  23. Is there a possibility that any parts of the site area will be rezoned for residential use?
  24. No. EPA has included a requirement for land use restrictions on the Westinghouse property in the Record of Decision to prevent residential development in the future. The City of Sunnyvale had proposed using part of the Westinghouse site for residential development and has been informed about the land use restriction.

  25. Are there any private wells in the neighborhood?
  26. Based on a well-survey, EPA found no private wells or agricultural wells in the nearby neighborhood.

  27. Could being exposed to the combination of chemicals found at the Westinghouse site greatly increase the health risks even if exposure to the individual chemicals is at low levels?
  28. The risk assessment methodology used by EPA takes into account the cumulative risk represented by exposure to all the contaminants of concern at the Westinghouse site. In fact, EPA considers this cumulative risk assessment to overstate the actual risk posed by the site after clean-up. The proposed clean-up measures result in exposure levels within the range considered acceptable for Superfund sites.

  29. What can be done to determine health effects, such as cancer and birth defects, for people who lived along the Westinghouse fenceline? Cancer seems to have occurred to residents at five houses on Sunnyvale Ave? Can't a health study be done and Westinghouse required to pay for it?
  30. Neither CDHS nor ATSDR have any authority to require Westinghouse to pay for a health study. As reported in the Health Outcome Data Evaluation section of the health assessment, we have reviewed information from the California's Cancer Surveillance Program for 1988 and 1989 for the neighborhood located nearest Westinghouse. The reported cases do not suggest any unusual patterns and are similar to the normal distribution of cancer cases in the general population. At this time, we do not have the census data needed for age, race, and sex or mobility in the area which is necessary before meaningful incidence rates can be calculated and compared to county, state, or national rates. We have been unable to obtain birth defects information due to budgetary cutbacks for the California Birth Defects Monitoring Program.

    ATSDR's Health Activities Recommendation Panel reviewed the health assessment for the Westinghouse site and concluded that follow-up health activities were not indicated at this time due to the uncertain and inadequate data regarding past exposure. Additionally, given the small number of residents possibly exposed, any increase in cancer would most likely not be detected in a study.

    Using the limited data available for residential yards bordering the Westinghouse fenceline, CDHS calculated a theoretical exposure dose for incidental ingestion of contaminated soil, inhalation of contaminated soil dust, and skin contact with contaminated soil by nearby residents. This exposure dose over a 30-year exposure meant that residents with affected yards may have a low increased risk of developing cancer over a lifetime (one more cancer per 10,000 people). An epidemiological study could not possibly distinguish between the high background rate of cancer (2,500 cancers per 10,000 people) typically seen in the population and this small increase (i.e., distinguishing between 2,500 cancer cases and 2,501 cancer cases). In fact, there are less than 1,000 potentially exposed residents rather than 10,000. Therefore, there would only be a possible increase of one-tenth of one cancer case per 1,000 people.

  31. What about health studies on workers? Can a survey be done on past and current worker health complaints?
  32. As identified under the Health Outcome Data Evaluation section of the health assessment, Westinghouse informed CDHS/ATSDR staff that in 1981, health evaluations including liver and blood analyses were performed on thirty nine employees and retirees who requested them; all liver functions were reportedly within normal range and no measurable amounts of PCBs were found in the blood analyses. CDHS requested additional information which will be reviewed when we receive it.

    CDHS/ATSDR staff has spoken with Mr. David Sundin, Chief of the Health Hazard Evaluation and Technical Assistance Branch at the National Institute of Occupational Safety and Health (NIOSH) to request information about how workers could request a health study. Mr. Sundin informed us that the Health Evaluation and Technical Assistance Branch within NIOSH is responsible for reviewing and responding to requests for worker related health hazard evaluations. Workers who are particularly interested in obtaining information from the 1981 health evaluations can request NIOSH to access these and review other worker health issues related to past PCB use at Westinghouse. CDHS/ATSDR staff has shared this information with workers at Westinghouse and also informed them about several studies on the effects of PCBs on worker health.

  33. If blood levels for workers were found to be in the normal range, what does that really mean?
  34. Westinghouse reported that the blood testing of 39 individuals in 1981 showed no measurable amounts of PCBs in any of the blood analysis and that blood analyses were completed with equipment that allowed identification of PCBs in the blood "at levels greater than 0.2 MCG/100 ML" (assumedly greater than two tenths of a microgram per 100 milliliters of blood). CDHS/ATSDR has no further information on the testing performed for workers.

  35. Do PCBs build up in the body?
  36. Yes, PCB's can build up in the body. PCB's generally tend to deposit in fat tissue and can be found in blood and breast milk of nursing mothers. Nearly everyone has been exposed to PCBs because they are found throughout the environment, and nearly all persons are likely to have some amounts of PCB's in their blood or fat that can be measured.

  37. What kind of medical tests exist to determine PCB exposure?
  38. There are tests to find out if PCB's are in blood, body fat, and breast milk. These tests are not routine clinical tests, but they can detect PCB's in people exposed to them in the environment or a work setting. High levels of PCB's in these fluids will show that you have been exposed to high levels of PCB's. However, these measurements cannot determine the exact amount or type of PCB's you have been exposed to or for how long you have been exposed. Also, they can not predict whether you will develop harmful health effects.

  39. Do you know if the apartment building that was asphalted in 1963 was ever tested? Does contamination exist under the asphalt?
  40. CDHS/ATSDR staff spoke with the EPA site manager who informed us EPA has not been able to verify whether soil under the apartment building was ever tested and it may represent a data gap. The site manager has checked the limited data available and indicates none of the data for off site soil was ever reviewed for quality assurance.


CONCLUSIONS

Based on the information reviewed, ATSDR and CDHS have concluded that this site is a public health hazard due to the past exposure to PCBs that residents and workers may have experienced. As noted in the sections on completed exposure pathways and toxicological evaluation, residents exposed to contaminated soils in their yards may have a low increased risk of developing cancer over a lifetime. Additional information about past exposure of workers and a review of available employee health records are needed before conclusions can be made about possible health effects to workers exposed to PCBs or other chemicals. CDHS has requested this information from Westinghouse, but it has not been provided. Information has been provided to Westinghouse workers on how to request a health hazard evaluation conducted by the National Institute for Occupational Safety and Health (NIOSH). CDHS has been informed that Westinghouse workers have requested a health hazard evaluation and NIOSH is currently considering the request. ATSDR and CDHS will evaluate any relevant additional information or data as it becomes available and assess the likelihood of an impact on community or employee health.

In its current state, the site does not present any apparent public health hazard to the general public. Present exposure of the general public to existing site contamination is not likely because the site is restricted and there are institutional controls in place. Present exposure of workers who engage in subsurface construction such as installation or maintenance of underground utilities in the area of contamination near Reservoir 2 is possible under present site conditions.

Future exposure to remediation workers who will be involved with proposed soil removal activities will be minimized if the work site is limited to authorized personnel who comply with applicable health and safety guidelines and use appropriate personal protective clothing and equipment.

Future exposure of residents and workers will also be prevented if land use restrictions are implemented and adhered to for on-site areas where contamination exists above levels of health concern.

For future exposure to groundwater, the site represents an indeterminate public health hazard because there is a data gap regarding the extent of groundwater contamination-off site. Future significant exposure to groundwater contaminants is unlikely if the proposed groundwater extraction and treatment system reduces concentrations of site-related contaminants to below levels of health concern, and no future drinking water wells are placed in areas of known contamination if groundwater remediation does not clean up contaminants to drinking water standards. However, with the use of appropriate technology, more extensive characterization is needed of the A/B1 aquitard to assess the nature and extent of the dense oily layer containing PCBs and TCB.


RECOMMENDATIONS

Prevent/Cease/Reduce Exposure Recommendations:

  1. In the areas of known groundwater contamination, implement institutional controls to prevent future use of contaminated groundwater for drinking water supplies until remediation has reduced contaminant concentrations to below levels of health concern.


  2. To minimize exposures during any future excavation or subsurface construction, the work site should be limited to authorized personnel who comply with applicable health and safety guidelines and use appropriate personal protective clothing and equipment.


  3. To implement and adhere to strict land use restrictions for all on-site areas until levels of contaminants are reduced to below levels of health concern.


  4. Take necessary action to prevent any exposure of local populations to site contaminants that may result from proposed remediation and/or removal activities.

Site Characterization Recommendations:

  1. Continue groundwater monitoring program to further characterize groundwater flow and levels of the affected aquifers, and to monitor drinking water sources.


  2. Expand the groundwater monitoring as needed to determine the extent of the off-site groundwater contamination in the affected aquifers.


  3. Implement measures for further containment of all groundwater contaminants in order to prevent further migration of contaminants.


  4. Implement measures to prevent any vertical migration of contaminants through the different aquifers.

Health Activities Recommendation Panel (HARP) Recommendations:

  1. The data and information developed in the Westinghouse Sunnyvale public health assessment has been evaluated by the ATSDR Health Activities Recommendation Panel for follow-up health activities. Although past exposure to contaminated soil has occurred for some residents and on-site workers, information is not presently available to allow a determination of the magnitude and public health significance of the exposure. Therefore, follow-up health activities are not indicated at this time. Community health education activities, however, are ongoing, and the California Department of Health Services will continue to address specific community health concerns as they arise. CDHS has requested additional health related data. When it becomes available, ATSDR and CDHS will evaluate the Westinghouse Sunnyvale site for any indicated follow-up actions.

 

PUBLIC HEALTH ACTIONS

Based on the recommendation of the HARP, ATSDR is not planning any follow-up health actions at this time. However, CDHS staff will continue community relations activities with the Westinghouse neighborhood community to share information about the site and to address health concerns as they arise. In addition CDHS and ATSDR will undertake the following public health actions:

  1. Review and evaluate any relevant worker health or exposure data that become available.


  2. Evaluate any additional health outcome data that are obtained.


  3. If NIOSH proceeds with a health hazard evaluation, review and evaluate this information when it is finalized.


  4. Update this public health assessment, if indicated, based on a review of the aforementioned exposure and health outcome data.

EPA has included the following in its Record of Decision for the Westinghouse site:

  1. Institutional controls to prevent well construction (for water supply purposes) in contaminated areas.


  2. Land use restrictions to prevent any residential development in the source area and to prevent excavation in the area where contaminated soils remain at depths greater than eight feet. Excavation in the upper eight feet after contaminated soil has been removed will be restricted to temporary subsurface work and will require that any disturbance to the fill or the asphalt cap must be restored once the temporary subsurface work is completed.


  3. Groundwater extraction to permanently contain the contaminated groundwater and to prevent further migration of contaminants. Extracted groundwater will be treated using technologies that result in the contaminants being destroyed.


  4. Permanent and ongoing monitoring of the affected aquifers to verify that the extraction system is effective in capturing the contaminated groundwater plume, reducing contaminant concentrations, and preventing further migration of the dense oily layer on top of the A/B1 aquitard.


  5. During the remedial design phase, EPA will require Westinghouse to install additional groundwater monitoring wells to further define the extent of the off-site groundwater contamination.


  6. EPA will conduct a review within five years after commencement of the remedial action, and every five years thereafter, to ensure that the remedy continues to provide adequate protection of human health and the environment.


  7. EPA requires the development and implementation of a health and safety plan for all site related activities in order to ensure worker health and safety.


  8. EPA will identify and take appropriate actions to prevent exposure of local populations to site contaminants that may result from proposed remediation and/or removal activities.

PREPARERS OF REPORT

Environmental and Health Effects Assessors:

Diana M. Lee, M.P.H.
Research Scientist
Environmental Health Investigations Branch
California Department of Health Services

Community Relations Coordinator:

Jane Riggan, M.S.W.
Impact Assessment, Inc., Consultant to
Environmental Health Investigations Branch
California Department of Health Service

ATSDR REGIONAL REPRESENTATIVES

Lynn Berlad
Regional Services, Region IX
Office of the Assistant Administrator

Gwendolyn Eng
Regional Services, Region IX
Office of the Assistant Administrator

William Nelson
Regional Services, Region IX
Office of the Assistant Administrator

ATSDR TECHNICAL PROJECT OFFICER

Burt J. Cooper, M.S.
Environmental Health Scientist
Division of Health Assessment and Consultation
Remedial Programs Branch, State Programs Section


CERTIFICATION

This public health assessment was prepared by the California Department of Health Services under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the health assessment was initiated.

Burt J. Cooper
Technical Project Officer, SPS, RPB, DHAC


The Division of Health Assessment and Consultation, ATSDR, has reviewed this health assessment and concurs with its findings.

Director, DHAC, ATSDR


REFERENCES

  1. EMCON Associates. Remedial investigation and feasibility report-Westinghouse Electric Corporation Sunnyvale, California facility, prepared for Westinghouse Electric Corporation, 1991.


  2. Agency for Toxic Substances and Disease Registry.Preliminary health assessment for Westinghouse Plant - Sunnyvale, California, DHHS, (Public Health Service), 1989.


  3. Tetra Tech, Inc. Site history of remedial investigations and work: 1981 through 1987 - Westinghouse Electric Corp. Site, Sunnyvale, California, prepared for U.S. Environmental Protection Agency, Region IX, 1989.


  4. Toxics Substances Control Division. Letter to Westinghouse Defense and Electronic Systems Center, June 26, 1984.


  5. San Francisco Bay Region, California Regional Water Quality Control Board. Order No. 84-63, Waste Discharge Requirement for Westinghouse Electric Corporation, Sunnyvale Site, Sunnyvale, Santa Clara County, 1984.


  6. San Francisco Bay Region, California Regional Water Quality Control Board. Order No. 85-94, Waste Discharge Requirement for Westinghouse Electric Corporation, Sunnyvale Site, Sunnyvale, Santa Clara County, 1984.


  7. Remedial Project Manager, Environmental Protection Agency. Personal communication by telephone, May 30, 1991.


  8. Environmental Protection Agency. "EPA to oversee Superfund investigation at Westinghouse in Sunnyvale" (fact sheet), 1988.


  9. Environmental Protection Agency. "EPA to oversee Superfund investigation at Westinghouse in Sunnyvale" (fact sheet), 1990.


  10. California Department of Health Services. Cancer incidence and mortality. California, 1988. California Health and Welfare Agency, 1991.


  11. California Department of Health Services. The toxics directory, 1990.


  12. Manager, Health and Safety, Westinghouse Electric Corporation Sunnyvale, CA. Personal communication by telephone, July 10, 1991.


  13. Tetra Tech, Inc. Community relations plan, Westinghouse Electric Corporation Sunnyvale, CA, prepared for U.S. Environmental Protection Agency, Region IX, 1989.


  14. Environmental Protection Agency. "EPA proposes cleanup plan for contamination at Westinghouse facility in Sunnyvale" (fact sheet), 1991.


  15. Agency for Toxic Substances and Disease Registry. Draft Health Assessment Guidance Manual. Atlanta, Georgia: Agency for Toxic Substances and Disease Registry, February 1991; DHHS, (PHS).


  16. Drinking Water and Groundwater Protection Branch, Environmental Protection Agency. Drinking water standards and health advisory table, Environmental Protection Agency, Region IX, 1991.


  17. Central Valley Region, California Regional Water Quality Control Board. A compilation of water quality goals, 1991.


  18. Environmental Epidemiology Section, California Department of Health Services. Draft memo to Hazardous Waste Management Branch, Toxic Substances Control Division, CDHS, 4/26/84.


  19. ICF Technology, Inc. Field audit of quarterly groundwater monitoring activities conducted at Westinghouse Electric Corporation's Marine Division Plant, 2/13/91.


  20. Tetra Tech, Inc. Quality Assurance Report, prepared for Environmental Protection Agency, Region IX, 9/89.


  21. Agency for Toxic Substances and Disease Registry. Toxicological profile for selected PCBs (Aroclor-1260, - 1254, -1248, -1242, -1232, -1221, and -1016. Atlanta, Georgia: Agency for Toxic Substances and Disease Registry, June 1989, DHHS publication no. (ATSDR)/TP-88/21.


  22. Environmental Protection Agency. Exposure Factors Handbook. Washington, DC Environmental Protection Agency, Office of Health and Environmental Assessment, July 1989; EPA document no. 600/8-89/043.


  23. Wabeke R, Weinstein R, Letz G. Current alert - PCBs. Clinical Toxicology 1990; 28(4), 505-526.


  24. Remedial Program Manager, Environmental Protection Agency, Region IX. Personal communication by telephone, 7/11/91.


  25. Agency for Toxic Substances and Disease Registry. Draft Toxicological profile for selected PCBs (Arochlor - 1260, 1254, 1248, 1242, 1232, 1221, and 1016). Atlanta, Georgia: ATSDR, October 1991.


  26. Environmental Protection Agency. Record of Decision, Westinghouse Superfund Site, Sunnyvale, California. October 16, 1991.

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