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PUBLIC HEALTH ASSESSMENT

ADVANCED MICRO DEVICES #915
SUNNYVALE, SANTA CLARA COUNTY, CALIFORNIA


SUMMARY

Advanced Micro Devices, Inc. building 915 (AMD 915) served as anactive semiconductor and microprocessor manufacturing facilityfrom 1974 until 1990. AMD 915 is located in Sunnyvale,California in Santa Clara County, approximately four miles southof San Francisco Bay. AMD 915 was included on the NationalPriorities List (NPL) by the United States Environmental Protection Agency (EPA) in September, 1990. The San FranciscoRegional Water Quality Control Board (RWQCB) is the lead agencyfor overseeing investigation and remediation at the site.

Waste solvents and acid-neutralization liquids contained in twounderground storage tanks leaked, causing contamination ofsubsurface soils and groundwater. The contamination originatingfrom the AMD 915 facility has not migrated off-site and thecontaminated groundwater has not impacted any private ormunicipal drinking water supplies. A separate plume originatingfrom three additional NPL sites located immediatelysouth-southwest of AMD 915 crosses a portion of the AMD 915 site.

The underground storage tanks suspected of leaking and somesubsurface soils have been removed. A system of groundwaterextraction and air stripping/liquid phase carbon adsorptiontreatment is currently operating at the site to restoregroundwater to acceptable drinking water standards. The AMD airstripper does not have an emission control device, resulting inthe release of low levels of volatile organic compounds to theambient air. However, no apparent risk exists for the communityfrom these emissions. In its proposed clean up plan, the RWQCBprojects that the treatment system will take approximately 12years to reach targeted clean up levels.

Based on information reviewed, the United States Agency for ToxicSubstances and Disease Registry (ATSDR) and the CaliforniaDepartment of Health Services (CDHS) conclude that no apparenthealth hazard exists at the AMD 915 site. The available evidenceindicates that humans have not been exposed to contaminantsrelated to the AMD 915 site at levels of public health concern. Therefore, follow-up health actions are not indicated at thistime. Future exposures to contaminated media are not likely tooccur as long as: 1) the groundwater extraction and treatmentsystem reduces concentrations of groundwater contaminants tobelow levels of health concern; 2) no future drinking waterwells are placed in areas of known contamination untilremediation has reduced contaminant concentrations below levelsof health concern; and 3) any future excavation/constructionprojects at the AMD 915 facility take the necessary precautionsto insure that workers are not exposed to contaminants abovelevels of health concern.


BACKGROUND

A. SITE DESCRIPTION AND HISTORY

Advanced Micro Devices, Inc. building 915 (AMD 915) was an activesemiconductor and microprocessor manufacturing facility from 1974until 1990. AMD 915 is located in Sunnyvale, California in SantaClara County, approximately four miles south of San FranciscoBay. Figure 1 shows the most important features that define thesite. Duane Avenue runs to the north of the site, and DeGuigneDrive to the south and to the east. A former junior high schooland surrounding recreational area now owned by WestinghouseElectric Corporation lies to the west of the site. In 1990,Advanced Micro Devices completed the construction of a newresearch and development facility known as the SubmicronDevelopment Center (SDC) immediately adjacent to the southwestcorner of AMD 915.

The United States Environmental Protection Agency (EPA) placedAMD 915 on the National Priorities List (NPL) in September 1990. AMD contracted with Engineering-Science in 1989 to conduct aRemedial Investigation and Feasibility Study (RI/FS) after EPAproposed that the site be placed on the NPL (1). The CaliforniaRegional Water Quality Control Board (RWQCB), San Francisco BayRegion (Region 2), is the lead agency regulating the AMD 915cleanup under a formal agreement with the EPA.

Staff from the Agency for Toxic Substances and Disease Registry(ATSDR) conducted a site visit in February 1989 and released apreliminary public health assessment for AMD 915 in August 1990(2). ATSDR, located in Atlanta, Georgia, is part of the PublicHealth Service, a Federal agency within the United StatesDepartment of Health and Human Services. ATSDR is authorized bythe Comprehensive Environmental Response, Compensation, andLiability ACT of 1980 (CERCLA) to conduct public healthassessments at hazardous waste sites. This public healthassessment is being prepared by the California Department ofHealth Services (CDHS) under a cooperative agreement with theATSDR and serves to update the preliminary public healthassessment.

The ATSDR/CDHS public health assessment is a mechanism to: 1)determine if there have been exposures to hazardous substancesfrom a particular hazardous waste site at levels that could posea health threat; 2) determine if it is possible to better definewhat impact the site may have had on the community by usinghealth related data; 3) determine whether all relevant currentand future exposure pathways are being addressed or sufficientlyaddressed by the responsible parties and the regulatory agenciesinvolved; and 4) provide the community with this information andaddress specific community health concerns. The public healthassessment report is based largely on a review of environmentalmonitoring and health outcome data and information, a site visit,and consultation with involved agencies and the public. Theenvironmental data and information reviewed is generally providedin the site's Remedial Investigation, Baseline Risk Assessmentand Feasibility Study reports, which are required by CERCLA.

Vicinity Map of AMD 915
Figure 1. Vicinity Map of AMD 915

Three additional NPL sites, AMD buildings 901/902, Signetics andTRW Microwave (now owned by FEI Microwave), are locatedimmediately south-southwest of AMD 915. Signetics is beingmanaged under the authority of the Resources Conservation andRecovery Act. The RWQCB is also the lead agency for these threesites. Figure 1 shows where these sites exist and theirproximity to AMD 915. Each of these three sites, AMD 901/902,TRW Microwave, and Signetics, has its own source ofcontamination, but the off-site contaminated groundwater areashave merged and the sites are treated as one unit for thepurposes of the investigation and development of clean-up plans(3).

Advanced Micro Devices built building 915 in 1974 andmanufactured semiconductors and microprocessors for theelectronics industry at the site until 1990. The companycurrently uses the building for research and development andoffice space (4). For its manufacturing processes, AdvancedMicro Devices uses or has used organic solvents such astrichloroethene (TCE), 1,1,2-trichloro- 1,2,2-trifluoroethane(Freon 113), acetone and trichlorobenzene (TCB). The companystopped using TCE in 1979. Waste solvents and acidneutralization liquids were stored in underground storage tanks. Freon waste and some waste oils and acids containing arsenic andchromium were stored in 55 gallon drums retained in a hazardousmaterials storage area which was expanded and renovated in 1982. A California certified hazardous waste hauler removed them toappropriate locations off site every month or two.

AMD discovered contaminated soil and groundwater at the site in1981. When AMD's contractors began to remove some of itsunderground storage tanks, they discovered two point sources ofcontamination. Figures 1 and 2 show the location of the pointsources. In 1981, International Technology, Inc. removed aleaking 1,500 gallon photoresist stripper tank from pad IV andabout 300 cubic yards of contaminated soil. In 1983,Engineering-Science supervised the removal of a second pointsource of contamination, a 4,200 gallon acid neutralizationsystem at pad C consisting of three tanks. One of the tanks hada hole in its wall, through which it was estimated that TCE mayhave leaked for up to six years. In addition to the tanks, about5,600 cubic yards of contaminated soil were removed and taken toan approved hazardous waste landfill for proper disposal. Theprincipal organic contaminants found in subsurface soil on siteat AMD 915 are TCE and TCB. The metals arsenic and chromium werealso found in soils (1).

AMD installed 27 underground storage tanks at the AMD 915facility since its construction in 1974. Starting in 1981, AMDhad all tanks removed with the exception of eight tanks used fortwo separate acid neutralization systems. Of all the removedtanks, only the photoresist stripper tank at pad IV and one ofthe pad C acid neutralization system tanks showed evidence ofleaking. The remaining eight tanks still in use aredouble-walled and contained in concrete vaults covered withgrating just below the ground. Designated AMD staff visuallyinspect all tank and chemical use areas daily, monitor allstorage facilities, and maintain logs. A Hazardous MaterialsManagement Plan for AMD 915 delineates all materials containmentand monitoring methods.

Map of AMD 915 showing location of groundwater monitoring and extraction wells, and point sources of contamination
Figure 2. Map of AMD 915 showing location of groundwater monitoring and extraction wells, and point sources of contamination

From 1982 to 1989, AMD's contractor, Engineering-Science,installed 42 monitoring wells to define the extent and magnitudeof groundwater contamination. Thirty-four monitoring wells arecurrently operational. Organic contaminants have been detectedin shallow groundwater zones to depths of approximately 65 feetbelow the ground surface. Multiple organic contaminants arepresent in groundwater on-site, including chloroform,1,1-dichloroethane (DCA), 1,1-dichloroethene (1,1-DCE), cis andtrans-1,2-dichloroethene (1,2-DCE),1,1,2-trichloro-1,2,2-trifluoroethane (Freon 113),trichlorobenzene (TCB), 1,1,1-trichloroethane (TCA), andtrichloroethene (TCE). Several metals have been found atelevated levels in groundwater on site, including antimony,arsenic, barium, beryllium, chromium, cobalt, mercury, nickel,and vanadium (1,5-9).

Between 1982 and 1983, AMD installed five on-site groundwaterextraction wells to retard off-site migration of contaminatedgroundwater. Seven additional extraction wells were placed northof the site along Duane Avenue between 1983 and 1987 to providean additional hydraulic barrier to trap the contaminant plume. Eight extraction wells are currently operating. The extractionwells have pumped much of the most shallow groundwater aquiferdry and have controlled the movement of pollutants in shallowgroundwater to depths of approximately 65 feet (10).

In addition to the on-site sources, the investigation discoveredcontaminated groundwater moving toward the AMD 915 site fromupgradient sources. The groundwater contaminant plume associatedwith the upgradient AMD 901/902, TRW Microwave and Signeticssites crosses a portion of the AMD 915 property and extendsseveral hundred feet north. Although releases from the AMD 915facility have contaminated the shallow aquifers beneath the site,the contamination has not migrated off-site and contributed toexisting groundwater contamination north of the site. Thecontaminated groundwater has not impacted any private ormunicipal drinking water supplies (10). Groundwatercontamination north of the site is being investigated separately(3).

An air stripping/liquid phase carbon adsorption system wasinstalled in 1984 to treat the extracted groundwater. An airstripper removes the majority of volatile organic contaminantsfrom the groundwater. After passing through the air stripper,the water is further treated using the carbon absorption system. In addition to the groundwater treated from own extraction wells,groundwater extracted from 18 other off-site wells, installed aspart of the clean-up activities for AMD 901/902, TRW Microwaveand Signetics, is piped to and treated at AMD 915. The watertreatment system also processes water pumped from four sumps usedto keep water from entering the basement of AMD 915. Thetreatment system removes 99% or more of the volatile organiccompounds from the groundwater (10). AMD currently reuses 30% ofthe water, plans to reuse 60% by the end of 1991, and has a longterm goal of 100% reuse (10). The treated water not currentlybeing reused is discharged to a storm drain that empties into theCalabazas Creek under a National Pollutant Discharge EliminationSystem (NPDES) permit (No. CA0028797).

B. SITE VISIT

On the morning of April 22, 1991, David Borgeson, Diana Lee,Marilyn Underwood and Jane Riggan from the CDHS ATSDR cooperativeagreement project visited the site under the guidance of theSenior Environmental Engineer and an Environmental Engineer forAMD. We observed the following:

  1. the site is fenced and guarded with security guards. Aguard house is situated at the entrance. To enter, staffmust show a badge with picture identification to a guardposted at the entrance. As visitors, to gain entrance, wehad to document authorization from the AMD staff persons wewere meeting, sign in, and be issued a temporary numberedbadge by the guard;

  2. asphalt parking lots and other 2- and 3-story buildingssurround the site. The terrain is flat and the existingsimple landscaping consisting of young trees and bushes isneatly maintained. Potential chemical hazards around thefacilities are clearly marked with Department ofTransportation labels and secured behind fences orstorehouses;

  3. potential chemical hazards around the facilities are clearlymarked with Department of Transportation labels and securedbehind fences or storehouses;

  4. the water treatment system is located on site and surroundedby a 12-foot cyclone/wood slat fence with a locked gate. The Senior Environmental Engineer informed us the systemprocesses 180 gallons per minute, About 25% of the treatedwater comes from on-site AMD 915 wells, 75% from off-sitewells related to the neighboring sites discussed previously;and

  5. the monitoring and extraction well-heads lie just below theground's surface, secured with manhole coverings. In ourmeeting with AMD's Senior Environmental Engineer and Environmental Engineer, they further clarified that AMD 915was no longer used as a production facility. The mainchemical usage area in the building is a laboratory used forresearch and development. Waste solvents used in thelaboratory are put into 55 gallon drums and removed off sitefor disposal.

About 630 employees have offices at building 915, a two storystructure with a basement. The basement, first and second floorshave a total area of about 265,000 square feet. The basement hasan area of about 44,000 square feet. At our request, the AMDstaff gave us a tour of the basement at AMD 915. Most of thebasement houses the mechanical, electrical and ventilationsupport systems for the building. In addition, an electronicslaboratory, a work room, a training room, and two office areastake up 12,160 square feet in the basement. About 25 people workin these basement rooms (4).

During our tour, we saw some small cracks and holes in theconcrete floor of the part of the basement housing the supportsystems. In the rooms used by AMD staff, industrial carpetingwas laid over the floor. Modular panels and furniture appearedto have been newly installed in two of the rooms with open officespace configurations. We noticed some "stuffiness" and odors inthe rooms, but when we asked the Environmental Engineer if therehad been any complaints from the workers stationed in thoserooms, he said he was not aware of any.

The AMD staff showed us the location of one of the remainingvaulted acid neutralization systems and explained how monitoringis done for any leakage. We observed backfilling of an areawhere several tanks had been removed the week before. Noenvironmental sampling was conducted during the site visit.

We did not tour the Submicron Development Center (SDC). The AMDstaff explained that the SDC facility is built on a concreteslab, has no basement and no underground solvent storage tanks. Waste solvents generated at the facility are stored in drumswhich are removed to hazardous waste disposal facilities. TheSDC has a vaulted acid neutralization system. About 75 of the630 staff with offices at building 915 spend much of their timein laboratories in the SDC (4).

C. DEMOGRAPHICS, LAND USE, AND NATURAL RESOURCES

DEMOGRAPHICS

According to 1990 census information, approximately 4,000 peoplelive in 1,413 housing units within a half mile of the AMD 915site. Seventy percent (70%) of this population is 18 years ofage or older. The current census information does not give anyfurther breakdown of housing units or age specific information. The census data show the ethnic/racial breakdown as follows: 38%white (not Hispanic), 34% Asian/Pacific Islander, 24% Hispanic,3% black, and 1% American Indian, Eskimo or Aleut. About 630employees have offices at building 915. About 25 people work inthe basement at building 915. About 75 of the 630 staff withoffices at building 915 spend much of their time in laboratoriesin the Submicron Development Center (4).

LAND USE

Residences, commercial businesses, and light industry lie withina one mile radius of the site. Most of the businesses andindustry in the area are related to semiconductor and electronicsmanufacturing. As noted previously, AMD built a new buildingknown as the Submicron Development Center immediately southeastof AMD 915 in 1989. In addition, two smaller AMD buildings arelocated to the east of building 915.

The closest homes are about 400 feet north of the site alongDuane Avenue. To the south near AMD 901/902, Parkside Commons, anew residential complex, is being completed. Upon completion,this complex will have a total of 192 apartments located in eightapartment buildings and a shared recreation building. The formerSunnyvale Junior High School facility borders the west side ofthe AMD 915 site. Westinghouse now owns the former school andsurrounding recreation facilities but does not occupy thefacility. Neighborhood residents and workers use the track,tennis courts, and softball and baseball fields surrounding theold junior high school for recreational purposes.

Lying to the north of Duane Avenue is the San Miguel School. Formerly a public elementary school, it now houses approximately200 children a day who attend either a state child developmentprogram, a state preschool, a YMCA child care program, or a HeadStart program. Not included in the fenced-off playground isabout a half acre of grassy land on the west side of the schoolwhich is apparently used as a neighborhood playground. Fair OaksPark, primarily a children's playground, also lies northwest ofthe site on the corner of Duane and Fair Oaks Avenue. Most ofthe site and areas surrounding the site consist of paved surfacesor industrial buildings. Very little, if any, agriculturalactivity occurs within a one mile radius of the site. The areaaround the site does not support abundant wildlife nor is it usedfor hunting.

As described in the Site Description and History section, threeother facilities known to have released contaminants similar oridentical to those found at the AMD 915 site are in closeproximity. The three facilities and the RWQCB are treating theoff-site groundwater contaminant plume attributed to these threesites as one unit for clean up purposes. This off-site plumeextends under the residential neighborhoods, the former SunnyvaleJunior High School, and the San Miguel school facilities (3).

NATURAL RESOURCES

No natural surface water bodies exist in the vicinity of thesite. However, the Santa Clara Valley Water District maintains aconcrete-lined drainage channel (Sunnyvale East Drainage Channel)along the western portion of the AMD 901/902 site. This channeldischarges storm water into the Calabazas Creek and ultimatelyinto the San Francisco Bay. Calabazas Creek lies about 1.5 mileseast of the site.

Three major water bearing zones (aquifers) defined as the A-, B-and C-aquifer zones exist below the site. The A-aquifer is theshallowest and the C-aquifer the deepest of the three zones. TheB-aquifer is further defined into B1 to B5 zones. Theapproximate depth below ground level at which these zones occurbeneath the AMD 915 site are as follows: A:7'-25'; B1:20'-38',B2:38'-65'; B3:65'-100'; B4:90'-110'; and B5:110'-123'. Belowthe five B aquifer zones lies a 50'-150' thick regional aquitard,known as the B-C aquitard which severely retards the movement ofwater and contamination from the B1 through B5-aquifers to theC-aquifer. The C-aquifer, which supplies most of the municipalwater in the region, lies below the regional aquitard. Groundwater in all of the water bearing zones flows in anorth-northeasterly direction.

The aquifer zones appear to consist of mostly discontinuouslayers and lenses of fine to coarse sand, gravel, and often asubstantial proportion of clay and silt. These predominantlydiscontinuous layers and lenses are separated and/or isolated bylow permeability clays and silts (aquitards).

Borehole logs related to the installation of two monitoring wellsand eight extraction wells at the AMD 915 site serve as thebasis for the description of the site hydrogeology. Informationfrom the AMD 915 site borehole logs and from borehole logs forthe neighboring sites (TRW, AMD 901/902, and Signetics) arecomparable in describing the water bearing zones underneath thegeneral study area.

Information obtained from a well survey conducted in the studyarea (11) and from the RWQCB indicates that no private ormunicipal drinking water supplies are affected by the sitecontamination. The only functional municipal drinking water wellidentified in the survey is a City of Sunnyvale water supply wellover 3,000 feet upgradient of the groundwater contamination. Allthe residences located north of the site which could potentiallybe affected by the contaminated groundwater are connected tomunicipal water supplies.

D. HEALTH OUTCOME DATA

On January 1, 1988, the state's cancer reporting system, theCalifornia Tumor Registry, began collecting data for the regionthat includes the AMD 915 site and surrounding areas. The statereleased the data for 1988 on February 18, 1991 (12). TheCalifornia Birth Defects Monitoring Program began collecting datafor Santa Clara County in 1983.


COMMUNITY HEALTH CONCERNS

No community health concerns specifically associated with AMD 915have been identified, although the nearby sites (AMD 901/902,Signetics and TRW) have raised some community concern regarding thepossibility of soil-gas contaminated with organic substancesgetting into residences and the San Miguel School (13). Thecommunity relations staff from the CDHS ATSDR cooperative agreementproject elicited community information about AMD 915 from theDirector of the Silicon Valley Toxics Coalition, city officialsfrom Sunnyvale, officials from the Santa Clara County HealthDepartment, two Santa Clara County Board of Supervisors staffpersons, and the community relations staff from the EnvironmentalProtection Agency and the CDHS Toxic Substances Control Program. None of the individuals contacted were aware of any recentcommunity health concerns regarding the AMD 915 site.

Although no health effects have been reported or ascribed to theAMD 915 site, this does not necessarily mean that they do not existnow or in the future. Following the discovery of the contaminationat the Fairchild and IBM facilities in South San Jose in the early1980's, the community became concerned about groundwatercontamination in Santa Clara County. In November, 1982, a group ofenvironmental, labor and other organizations concerned aboutgroundwater contamination formed The Silicon Valley ToxicsCoalition.

The RWQCB has been responsible for overseeing the clean-up ofseveral of the Superfund sites in the Santa Clara Valley. InJanuary 1990, the RWQCB released their Community Relations Plan forSunnyvale, incorporating the community relations plans for AMD901/902, Signetics, TRW, AMD Arques, and AMD 915 into a single plan(14). This plan identified seven primary historical concerns inthe Santa Clara area as being: 1) concern about the quality ofdrinking water; 2) concern whether the extent of the problem hadbeen determined; 3) concern about what would happen if thecontamination spread; 4) concern about what is being done to cleanup the soil and groundwater; 5) concern about what happens to thecontaminated groundwater that was pumped out; 6) concern about whatthe schedule for clean-up is; and 7) concern about how propertyvalues would be effected?

In March 1991, RWQCB released Fact Sheet 2 announcing the proposedcleanup plan for AMD 915 (10). On March 20, 1991 staff from theRWQCB presented the recommended cleanup alternatives to its Board. The meeting marked the beginning of the public comment period whichwas originally designated to end April 19, 1991 but which wasextended to May 20, 1991. A public meeting held on March 28, 1991provided information about AMD 915 and neighboring sites. Approximately 40 people attended this public meeting. Peopleattending the meeting did not voice any concerns specific to theAMD 915 site. Rather, the comments made by attendees mainlydescribed concerns regarding the AMD 901/902, Signetics and TRWsites and their commingled off-site groundwater contaminant plume. The contaminant plume associated with the three contiguous sitescrosses a portion of the AMD 915 site.


ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

This section presents the contaminants of concern in eachenvironmental medium. The environmental sampling investigationconducted at AMD 915 has resulted in a large quantity of analyticaldata. Analyses have detected multiple contaminants. Subsets ofcontaminants of concern in each medium were selected from allcontaminants detected at the site in order to focus the publichealth assessment on those contaminants that are most likely topose a health risk. Their selection does not necessarily mean thatthey pose a health threat but only that they will be evaluatedfurther in the public health assessment. Subsequent sections willevaluate whether individuals have been or could be exposed to thecontaminants of concern and will determine whether such exposureshave public health significance.

The following criteria were used to select or eliminatecontaminants of concern: 1) the quality and adequacy of theenvironmental sampling and analysis, 2) the frequency ofdetection, 3) a comparison with background concentrations, 4) acomparison with field and laboratory blanks (some chemicalsdetected in samples may not be site-related but rather the resultof field or laboratory contamination), and 5) a comparison withhealth guidance values. Comparison values used to selectcontaminants of concern include the following:

EMEG - ATSDR Environmental Media Evaluation Guide

CREG - ATSDR Cancer Risk Evaluation Guide

HA - EPA Health Advisory for drinking water

MCLG - EPA Maximum Contaminant Level Goal

MCL - EPA Maximum Contaminant Level

CA MCL - California Maximum Contaminant Level

EMEGs are media specific values developed by ATSDR to serve as anaid in selecting environmental contaminants that need to be furtherevaluated for potential health impacts. EMEGs are based onnoncarcinogenic end-points and do not consider carcinogeniceffects. EMEGs are calculated from either an ATSDR Minimal RiskLevel (MRL) or an EPA Reference Dose (RfD). Both the MRL and theRfD are estimates of daily exposure to a chemical that is unlikelyto cause adverse, noncarcinogenic, health effects. CREGs are mediaspecific values developed by ATSDR to serve as an aid in selectingcontaminants of concern that are potential carcinogens. CREGs arebased on EPA cancer slope factors which give an indication of therelative carcinogenic potency of a particular chemical.

EPA has developed health based, non-regulatory Health Advisories(HAs) for some chemicals in drinking water. HAs represent aconcentration below which noncancer adverse health effects are notexpected to occur. A margin of safety is included to protectsensitive members of the population. MCLGs and MCLs are developedby EPA under the authority of the Safe Drinking Water Act. MCLGsare non-enforceable goals, set at levels which would result in noknown, or anticipated, adverse health effects with an adequatemargin of safety. In setting MCLGs for known or probable humancarcinogens, EPA makes the assumption that there is no absolutely"safe" level of exposure (i.e., known as the non-thresholdassumption) and sets the MCLG at zero. MCLs are enforceablestandards set as close to MCLGs as possible, but in addition tohealth factors, MCLs are required by law to consider thetechnological and economic feasibility of removing the contaminantfrom the water supply. The limit that is set must be feasiblegiven the best available technology and treatment techniques. Generally, MCLs and MCLGs represent allowable lifetime exposurelevels to contaminants for a 70-kg adult who is assumed to ingesttwo liters of water per day for a 70-year lifetime. For somechemicals, California has established its own MCL values, which areequal to or stricter than Federal EPA values.

A. TOXIC CHEMICAL RELEASE INVENTORY (TRI) SEARCH

To identify other possible releases that could contribute toenvironmental pollution, the CDHS ATSDR Project staff searched theToxic Release Inventory (TRI) for the years 1987, 1988 and 1989(the years for which TRI data were available on-line at the timethis public health assessment was written). The TRI containsinformation on estimated annual releases (emission rates) of toxicchemicals to the environment (via air, water, soil, or undergroundinjection) and is based on data submitted to the EPA by certainindustries (Standard Industrial Classification codes 20 through 39with 10 or more full-time employees).

The estimates are primarily based upon theoretical mass balanceequations and assumed leakage rates developed by EPA. Someenvironmental monitoring data is reported by industry and isincorporated into TRI. The TRI database contains information onreleases from active industrial facilities from 1987 to present. Therefore, the database will not contain any information concerningclosed facilities or any facilities not required to report to EPAsuch as landfills.

TRI data can be used in an ATSDR/CDHS Public health assessment toget a general idea of the current environmental emissions occurringat a site. The RI/FS report that is the basis of much of theexposure assessment generally only contains information and dataassociated with the actual "Superfund" site (e.g., a tank or lagoonon the property), and not the entire facility. TRI data can beused to determine whether the on-going facility wide emissions maybe contributing an additional environmental burden to the nearbypopulation.

As provided in TRI, Advanced Micro Devices reported in 1987 thatabout 3,000 pounds of six different chemicals were released to airat building 915. Each of the six chemicals was roughly estimatedto contribute 500 pounds to the total air releases. The chemicalsincluded sulfuric acid, sodium hydroxide (solution), hydrochloricacid, phosphoric acid, nitric acid, and hydrogen fluoride. Nochemicals were reported to have been released to water or land in1987.

In 1988, four different chemicals were reported to have beenreleased to the air at AMD 915. As in 1987, 500 pounds of each ofthese four chemicals were roughly estimated to contribute to atotal reported air release of 2,000 pounds. The chemicals includedsulfuric acid, hydrochloric acid phosphoric acid, and nitric acid. No chemicals were reported to have been released to water or landin 1988.

Total air emissions from AMD 915 in 1989 were estimated at 4,900pounds. The three chemicals reported released include sulfuricacid (250 pounds), hydrochloric acid (4,623 pounds determined fromair monitoring), and phosphoric acid (27 pounds). Again in 1989,no chemicals were reported to have been released to water or land. Emissions of TCE and Freon 113 from the air stripper at AMD 915were not reported in TRI.

B. ON-SITE CONTAMINATION

SUBSURFACE SOIL

Two point sources of subsurface soil contamination have beendefined at the AMD 915 site: a photoresist stripper tank at pad IVand an acid neutralization system at pad C. Figures 1 and 2 showthe location of each point source. A discussion of thecontaminants found at each of the two point sources is given below. Only one contaminant, TCE, was selected as a contaminant of concernin subsurface soil.

Photoresist stripper tank, Pad IV

The photoresist stripper tank and about 300 cubic yards ofcontaminated soil were removed in 1981. The limited informationavailable about the original excavation indicate that InternationalTechnology Corporation collected seven soil samples from depths of16-19 feet on the sides of the excavation. Soil samples were foundto contain elevated levels of benzene, toluene, TCB, and xylenes. The lateral extent of the original contamination could not be fullydetermined due to the incomplete records.

To remove this data gap, AMD arranged in July 1990 for eight soilsamples to be collected and analyzed to assess the extent ofresidual contamination in the soil beneath the previously excavatedtank. The 1990 data show samples were taken at depths between 8and 21.5 feet below ground surface, at points around the originalexcavation instead of in the original area due to the location ofexisting structures. The RI/FS only reported levels for 1,2,4-TCB,1,2,3-TCB and 17 metals. Only one of the samples showedconcentrations of 1,2,4-TCB and 1,2,3-TCB, at 500 ppb and 150 ppbrespectively. Some of the metals were present at levels aboveaverage for the region, although all were within background rangesand not at levels of health concern. Benzene, toluene and xyleneswere not detected (15). Based on the 1990 sampling, the RWQCBconcluded that no residual on-site soil contamination from theleaking photoresist stripper tank exists at AMD 915 which requiresfurther remediation.

Acid Neutralization System, Pad C

In 1981-82, Woodward-Clyde consultants identified soilcontamination around a three tank acid neutralization system. Thechemicals TCE, TCB and Freon 113 were reported to be the majorcontaminants. In 1982-83, Engineering-Science consultantssupervised the excavation of the tanks, one of which had a hole inits wall, and the removal of about 5,700 cubic feet of contaminatedsoil. The central part of the excavation, with the tanks locatedin the middle, consisted of an area approximately 48' by 60' by30-34' deep. On each side of the central area, an areaapproximately 18' by 45' by 20' deep was excavated. The excavationwas backfilled and covered with concrete.

The RI/FS conducted by Engineering-Science states that "excavationaccomplished removal of the majority of the TCE and TCBcontamination." However, a comparison of soil values prior to andafter excavation can not be made. Information provided in theRI/FS does not give a clear indication of the sampling done priorto excavation, although the RI/FS states that "soils were removedif they contained more than one part per million" (1000 ppb). Sampling done after excavation shows the highest concentrations ofTCE and TCB appear immediately above the water table along thenorth and eastern boundaries of the excavation. The values ofsamples taken adjacent to the water table may reflect groundwaterconcentrations and may not be representative of actual soillevels.

For TCE the maximum concentration reported above the water table is2,800 ppb, with the sample taken along the northern boundary of theexcavation approximately 24 feet from the removed tank at a depthof approximately 15 feet. Along the southern boundary of theexcavation, TCE was generally less than 50 ppb. The maximum totalTCB concentration recorded above the water table was 96,000 ppb, ina sample taken approximately 45 feet east of the removed tank at adepth of 15 feet. Two other contaminants detected but below ATSDRhealth guidance values include Freon 113 (9,600 ppb) and TCA (1ppb).

GROUNDWATER

Since 1982, AMD's contractor has installed 42 monitoring wells tocharacterize the vertical and lateral extent of groundwatercontamination. Thirty-four of these wells are still operational. These wells serve to monitor water quality in the A-, B1-, B2- andB3-aquifers at AMD 915. The contaminant TCE is the primaryindicator chemical for contaminated groundwater because itsconcentrations are the highest compared to the other contaminants,and it has widespread distribution and persistence. Also, the dataconsistently show 1,2-DCE, which is a by-product of TCEdegradation.

Four organic compounds were detected at levels above comparisonvalues, including chloroform, 1,1-DCE, 1,2-DCE, and TCE. Maximumconcentrations detected on-site, detection frequency and comparisonvalues for organic contaminants of concern are presented in Table1. In samples of groundwater, TCE was the contaminant mostconsistently found at higher levels.

Table 1.

MAXIMUM CONCENTRATION, DETECTION FREQUENCY AND COMPARISON VALUES FOR ORGANIC CONTAMINANTS OF CONCERN IN GROUNDWATER ON-SITE AT AMD 915a
Chemical Maximum Conc. (ppb)b Frequency of Detectionc Comparison Value (ppb) Comparison Value Source

Chloroform 8 22/212 5.7 WATER CREG
1,1-Dichloroethene 50 40/212 0.06 WATER CREG
1,2-Dichloroethene 520 143/212 70 HA
Trichloroethene 3,800 176/212 None

a Data from 14 quarterly groundwater monitoring events during thetime period October 1987 through January 1991 (1,5-9).

b Maximum concentration detected in parts chemical per billionparts water (ppb).

c Number of samples with the contaminant above the detectionlimit, divided by the total number of samples analyzed.

In January 1990, one sample of groundwater taken from well 19-D wasanalyzed for arsenic and chromium. Arsenic was not detected (thedetection limit was 5 ppb), but the concentration of total chromiumwas 90 ppb. Well 19-D is screened (open) in the B1-aquifer and islocated about 200 feet downgradient (north) of the source ofcontamination. Sampling for priority pollutant metals ingroundwater at AMD 915 has been done on a quarterly basis sinceApril 1990. Table 2 lists the maximum concentrations of metalsdetected from five groundwater samplings covering the periodJanuary 1990 through January 1991. Eight metals were detected atlevels above comparison values including antimony, arsenic, barium,beryllium, chromium, mercury, nickel and vanadium. No guidancevalue existed for cobalt.

Table 2.

MAXIMUM CONCENTRATION, DETECTION FREQUENCY, AND COMPARISON VALUES FOR METALS OF CONCERN IN GROUNDWATER ON-SITE AT AMD 915a
Chemical Maximum Conc. (ppb)b Frequency of Detectionc Comparison Value (ppb) Comparison Value Source

Antimony 606 5/17 3 HA
Arsenic 12 3/18 0.03 WATER CREG
Barium 2,190 17/17 2,000 HA
Beryllium 7 1/17 0.008 WATER CREG
Chromium 653 10/18 100 HA
Cobalt 144 4/17 NA NA
Mercury 3 6/17 2 HA
Nickel 1,110 8/17 100 HA
Vanadium 564 10/17 20 HA

a Based on monitoring well data from five quarterly groundwatermonitoring events during the time period January 1990 throughJanuary 1991 (1,5-9).

b Maximum concentration detected in parts chemical per billionparts water.

c Number of samples with the contaminant above the detectionlimit, divided by the total number of samples analyzed.

NA= Not Available.

Tables 3 and 4 list the maximum concentration and detection frequency of organic and inorganic chemicals in the A-, B1-,B2- and B3-aquifers on site at AMD 915. Thirteen monitoring wells extend into the A-aquifer. However, due to the operation of the extraction wells at the AMD 915 site coupled with prevailing drought conditions, many of these wells have been dry since September 1988. During the five sampling events from January 1990 through January 1991, either nine or ten of the thirteen A-aquifer wells were dry and could not be sampled. The remaining A-aquifer monitoring wells with measurable water in them are outside the area captured by the extraction well system. Therefore, the current contamination in the A-aquifer cannot be defined. However, one well located near the original contamination point source was last sampled in December 1987 prior to going dry and found to have 65 ppb TCE, as compared to 190 ppb TCE when sampled in November 1984. Also, samples taken for the first time from another well located on the south side of AMD 915 and the newly constructed Submicron Development Center had TCE concentrations ranging from 130 ppb to 200 ppb.

Eleven monitoring wells characterize the B1-aquifer at AMD 915. Data from these wells show that the extraction systems at AMD 915and neighboring sites have resulted in a mixture of contaminantchemicals derived from multiple sources appearing at the AMD 915site, making characterization of the plumes very difficult. Overall, however, the RWQCB believes the extraction and treatmentof groundwater since 1984 has lowered the chemical concentration inthe general area and controlled the off-site groundwater migrationof the contamination attributed to the AMD 915 site. Data analysesshow a trend of decreasing TCE and 1,2-DCE concentrations. Otherchemicals inconsistently detected in the B1-aquifer during theOctober 1987-January 1991 period include chloroform, DCA, 1,1-DCE,Freon 113, 1,2,4-TCB, and TCA.

There are nine monitoring wells for the B2-aquifer. TCE, 1,2-DCE,and Freon 113 were frequently detected in the B2-aquifer during theperiod October 1987 through January 1991. Other organiccontaminants detected in the B2-aquifer during this time periodinclude 1,1-DCE, 1,2,4-TCB and TCA. Only one monitoring wellextends into the B3-aquifer. No contamination has been detected inthis aquifer.

Table 3.

MAXIMUM CONCENTRATION AND DETECTION FREQUENCY OF ORGANIC CONTAMINANTS OF CONCERN IN EACH GROUNDWATER AQUIFER ON-SITE AT AMD 915a
Chemical A-Aquifer B1-Aquifer B2-Aquifer B3-Aquifer
Max. Conc. (ppb)b Det. Freq.c Max. Conc. (ppb) Det. Freq. Max. Conc. (ppb) Det. Freq. Max. Conc. (ppb) Det. Freq.
Chloroform 8 3/6 3 2/34 ND 0/44 ND 0/2
1,1-DCE ND 0/6 3 3/34 1 1/44 ND 0/2
1,2-DCE 490 3/6 520 32/34 100 22/44 ND 0/2
TCE 150 4/6 2,800 32/34 650 35/44 ND 0/2

a Based on monitoring well data from five quarterly groundwatermonitoring events during the time period January 1990 throughJanuary 1991 (5-9). The depths below ground surface for eachaquifer are as follows: A:7'-25', B1:20'-38', B2:38'-65',B3:65'-100'.

b Maximum concentration detected in parts chemical per billionparts water (ppb).

c Detection Frequency = number of samples with the contaminantabove the detection limit, divided by the total number ofsamples analyzed.

ND = Not detected.


Table 4.

MAXIMUM CONCENTRATION AND DETECTION FREQUENCY OF METALS OF CONCERN IN EACH GROUNDWATER AQUIFER ON-SITE AT AMD 915a
Chemical A-Aquifer B1-Aquifer B2-Aquifer B3-Aquifer
Max. Conc. (ppb)b Detect. Freq.c Max. Conc. (ppb) Detect. Freq. Max. Conc. (ppb) Detect. Freq. Max. Conc. (ppb) Detect. Freq.
Antimony ND 0/1 606 3/8 110 2/8 NS NS
Arsenic ND 0/1 12 3/9 ND 0/8 NS NS
Barium 83 1/1 2,190 8/8 237 8/8 NS NS
Beryllium ND 0/1 7 1/8 ND 0/8 NS NS
Chromium ND 0/1 653 7/9 35 3/8 NS NS
Cobalt ND 0/1 144 4/8 ND 0/8 NS NS
Mercury ND 0/1 3 5/8 1 1/8 NS NS
Nickel ND 0/1 1,110 6/8 47 2/8 NS NS
Vanadium ND 0/1 564 7/8 35 3/8 NS NS

a Based on monitoring well data from five quarterly groundwatermonitoring events during the time period January 1990 thoughJanuary 1991 (5-9). The depths below ground surface for eachaquifer are as follows: A:7'-25', B1:20'-38', B2:38'-65',B3:65'-100'.

b Maximum concentration detected in parts chemical per billionparts water (ppb).

c Number of samples with the contaminant above the detectionlimit, divided by the total number of samples analyzed.

NS = Not Sampled

ND = Not Detected

AIR

Release of contaminants from the air stripping treatment system arenot controlled by a vapor phase activated carbon purificationsystem. As a result, there have been and currently are someemissions released to the ambient air. On August 27 and 28, 1991,Acurex Inc. sampled emissions from the air stripper at AMD 915. Three samples were collected using vacuum canisters over a periodof six hours. The canister with the highest organic concentrationscontained cis 1,2-dichloroethene (780 ug/m3), trans 1,2-dichloroethene (9.2 ug/m3), trichloroethene (9,000 ug/m3), 1,1,1-trichloroethane (100 ug/m3), and vinyl chloride (1.3 ug/m3).

C. OFF-SITE CONTAMINATION

GROUNDWATER

A large, commingled groundwater contamination plume associated withthe upgradient AMD 901/902, TRW Microwave, and Signetics NPL sitescrosses a portion of the AMD 915 facility and extends severalhundred feet north. Although releases from the AMD 915 facilityhave contaminated the shallow aquifers beneath the site, thecontamination has not migrated off-site and contributed to existinggroundwater contamination north of the site. Groundwatercontamination north of the site has been investigated separately(3), and a separate public health assessment is being prepared toaddress the potential public health impacts of releases from theaforementioned nearby NPL sites.

SURFACE WATER

Calabazas Creek is the closest surface water body. AMD 915discharges treated groundwater to the storm sewer which in turndischarges to Calabazas Creek. This discharge is permitted by theNational Pollution Discharge Elimination System (NPDES No.CA0028797). Concentrations of site related contaminants aremonitored on a monthly basis in the effluent water. Concentrationsare generally below 5 ppb for each organic contaminant, includingTCE (1).

AIR

No off-site air monitoring or dispersion modeling has beenconducted.

D. QUALITY ASSURANCE AND QUALITY CONTROL

In preparing this public health assessment, ATSDR and CDHS rely onthe information provided in the referenced documents and assumesthat adequate quality assurance and quality control measures werefollowed with regard to chain-of-custody, laboratory procedures,and data reporting. The accuracy of the conclusions contained inthis public health assessments is determined by the completenessand reliability of the referenced information.

E. PHYSICAL AND OTHER HAZARDS

Observations made at the time of the site visit did not indicateany physical or other hazards that would be expected to present aparticular threat to public health.


PATHWAYS ANALYSES

To determine whether on-site workers or nearby residents areexposed to contaminants migrating from the site, ATSDR/CDHSevaluates the environmental and human components that lead to humanexposure. This pathway analysis consists of five elements: 1) asource of contamination; 2) transport through an environmentalmedium (e.g., air, water); 3) a point of exposure; 4) a route ofhuman exposure; and 5) an exposed population.

ATSDR/CDHS identifies exposure pathways as completed, potential, oreliminated. Completed pathways require that the five elementsexist and indicate that exposure to a contaminant has occurred inthe past, is currently occurring, or will occur in the future. Potential pathways exist when at least one of the five elements ismissing, but could exist. Potential pathways indicate thatexposure to a contaminant could have occurred in the past, could beoccurring now, or could occur in the future. If based only oncontaminant fate and transport modeling, or if it is questionablewhether significant exposure is occurring, a pathway may be labeledas potential (but indeterminate) until information becomesavailable. Eliminated pathways require that at least one of thefive elements is missing and will never be present. Completed andpotential pathways, however, may be eliminated when they areunlikely to exist.

A. COMPLETED EXPOSURE PATHWAYS

Evaluation of existing information and data for AMD 915 did notfind any pathways resulting in past or current exposures tosignificant levels of site-related contaminants.

B. POTENTIAL EXPOSURE PATHWAYS

One potential exposure pathway identified involves outdoor airexposure to contaminants released from the air stripping treatmentsystem; emissions are not controlled by a vapor phase activatedcarbon purification system. As a result, there have been andcurrently are some emissions released to the ambient air. Theelements of this potential pathway are summarized in Table 5.

Table 5.

POTENTIAL EXPOSURE PATHWAYS
Pathway Time Frame Source of Contamination Transport Medium Point of Exposure Route of Exposure Exposed Population

Outdoor Air Past, current, future Air stripper Air Community near AMD 915 facility Inhalation Workers and residents near AMD 915 facility

C. ELIMINATED EXPOSURE PATHWAYS

This public health assessment evaluated and eliminated threepathways based on the fact that they are not likely to occur. Thethree pathways are summarized in Table 6 and discussed below.

Table 6.

ELIMINATED EXPOSURE PATHWAYS
Pathway Time Frame Source of Contamination Transport Medium Point of Exposure Route of Exposure Exposed Population

Indoor Air Past, current, future Contaminated groundwater and subsurface soil Air AMD building 915 Inhalation AMD personnel
Shallow groundwater Future Contaminated groundwater Groundwater Future water supply wells Inhalation, ingestion, skin absorption Future shallow groundwater well users
Construction Future Contaminated groundwater and subsurface soil Soil, air AMD 915 property Inhalation, ingestion, skin absorption AMD personnel and future excavation workers

INDOOR AIR

Organic contaminants transported via soil-gas may potentially enterand accumulate in structures near or above the groundwatercontaminant plume. However, the groundwater plume at the AMD 915site had its origins outside and to the north of the building. Thedirection of groundwater flow in the area is to the north-northeast. The contaminant plume is contained on-site and islocated to the north of building 915. Groundwater plume mapsindicate that only very low levels of VOCs, if any, are present ingroundwater under the building. Appreciable exposure via thispathway is considered unlikely.

FUTURE SHALLOW GROUNDWATER WELL USE

The concentrations of contaminants in groundwater are at levelsthat would be of health concern if domestic, agricultural orindustrial use of the contaminated groundwater occurred. There areno private or municipal wells in the impacted area and thereforethis does not present a current pathway. The likelihood of a wellbeing placed within the confines of AMD 915's contaminant plume islow. At this time, sufficient water for municipal use is availablefrom other aquifers having higher quality water and water yield. Also, local regulations may make it difficult to install wells inthe area due to the requirement of a 50 foot sanitary seal aroundthe well. Since these regulations do not preclude the installationof wells in the area, the cleanup plan for the AMD 915 includesinstitutional controls in the form of a deed restriction toeliminate the installation of wells on-site. Appreciable exposureto groundwater contaminants in the future is unlikely if: 1) thegroundwater extraction and treatment system reduces concentrationsof contaminants to below levels of health concern; and 2) no futuredrinking water wells are placed in areas of known contaminationuntil remediation has reduced contaminant concentrations belowlevels of health concern.

FUTURE CONSTRUCTION

Residual sub-surface soil contamination exists near the contaminantsources at AMD 915. Concentrations of TCE are highest immediatelyabove the water table, at about 15 feet below ground surface. Future excavation or construction on site at AMD 915 could resultin exposure to workers, and others, if runoff and tracking ofcontaminated soil occurs. During the construction of the SubmicronDevelopment Center on the AMD 915 property, organic compoundsvolatilizing from the construction site were observed, althoughconcentrations were found not to exceed permissible exposure limits(1). While the deed restriction required by the site cleanup planis not intended to regulate site construction activities, it isintended to serve as a reminder and as a warning to any future siteowners or developers of the existence of site contamination. Appreciable exposures in the future are unlikely if construction orexcavation sites are limited to authorized personnel usingappropriate personal protective equipment.


PUBLIC HEALTH IMPLICATIONS

A. TOXICOLOGICAL EVALUATION

Using the current air stripper emissions data presented in theEnvironmental Contamination and Other Hazards Section, Acurexfollowed the California Air Pollution Control Officers Association(CAPCOA) facilities prioritization procedure to determine ifreleases from the air stripper present a public health threat tothe community. The dispersion adjustment procedure, outlined inthe CAPCOA Air Toxics Assessment Manual, was used to calculatecancer and non-cancer prioritization scores. The selecteddispersion adjustment assumes that the stack is between 0 and 20meters tall and that the nearest population is between 100 and 250meters away. The total cancer and non-cancer score wasapproximately 0.5. According to the Bay Area Air QualityManagement District, a score of less than one would result in acancer risk of no more than 1 x 10-5. The CDHS considers thisscreening methodology to represent a health conservative approach. Therefore, CDHS believes that no apparent risk exists for thecommunity due to releases from the air stripper (17).

Without additional information on dispersion of the chemicals andpossible concentrations at points of human contact, it is notpossible to assess the public health implications of the releaseinformation contained in the Toxic Chemical Release Inventorydatabase. The reported releases vary substantially from year toyear and the accuracy of the information is unknown.

B. HEALTH OUTCOME DATA EVALUATION

No complete past or current exposure pathways of concern wereidentified at the AMD 915 site nor has there been any communityconcerns raised about the site. Therefore, an evaluation of healthrelated data is not warranted.

C. COMMUNITY HEALTH CONCERNS EVALUATION

As indicated previously, no community health concerns associatedwith AMD 915 have been identified. The public health assessmentfor AMD 915 was released for public comment from March 25 untilApril 22, 1992. The one comment received during the public commentperiod was from Advanced Micro Devices, Inc. No comments werereceived from local residents. Comments received have beenincorporated into the report. The public comment draft publichealth assessment for AMD 915 indicated a concern about possiblesoil-gas transport to and accumulation within building 915. Comments received from AMD and a reevaluation of this pathwayresulted in the elimination of this pathway as a pathway of concernand the reclassification of the site from "indeterminate publichealth hazard" to "no apparent public health hazard".


CONCLUSIONS

The available information does not indicate that humans are or havebeen exposed to contaminants related to the AMD 915 site at levelsof concern. Therefore, ATSDR and CDHS have concluded that thissite poses no apparent public health hazard. An evaluation ofexisting health related data is not warranted due to the absence ofexposure to contaminants at levels of concern and lack of communityhealth concerns. Significant future exposures to site relatedcontaminants are not likely if: 1) the groundwater extraction andtreatment system reduces concentrations of site-relatedcontaminants to below levels of health concern; 2) no futuredrinking water wells are placed in areas of known contaminationuntil remediation has reduced contaminant concentrations belowlevels of health concern; and 3) any future excavation/constructionprojects at the AMD 915 facility take the necessary precautions toinsure that workers are not exposed to contaminants above levels ofhealth concern.


RECOMMENDATIONS

A. CEASE/REDUCE EXPOSURE RECOMMENDATIONS

  1. In the areas of known groundwater contamination, institutionalcontrols should be implemented to prevent future use ofcontaminated aquifers for drinking water supplies untilremediation has reduced contaminant concentrations to belowlevels of health concern.

  2. To minimize exposures during any future excavation orconstruction on the AMD 915 property, the work site should belimited to authorized personnel using appropriate personalprotective equipment.

B. HEALTH FOLLOW-UP RECOMMENDATIONS

  1. The data and information developed in the public healthassessment for the AMD 915 site has been evaluated by the ATSDRHealth Activities Recommendation Panel (HARP) for follow-uphealth activities. The available information does not indicatethat humans are or have been exposed to site relatedcontaminants at levels of public health concern. Therefore,follow-up public health actions are not indicated at this time. However, if additional data become available, ATSDR and theCalifornia Department of Health Services may reevaluate thissite for any indicated follow-up health activities.

PUBLIC HEALTH ACTIONS

  1. Based on the recommendation of the ATSDR Health ActivitiesRecommendation Panel, this site is not being considered forfollow-up public health actions at this time.

  2. The Record of Decision (ROD) for AMD 915 was completed andsigned by EPA on August 26, 1991. The ROD presents the selectedclean-up plan for the site. The clean-up action chosen was tomaintain the existing groundwater extraction system with theexisting treatment system of an air stripper followed by carbonabsorption, until acceptable drinking water standards areattained (18).

  3. Preventing the use of contaminated aquifers as drinking watersupplies and minimizing exposures during any future constructionon the AMD 915 property will be addressed via institutionalcontrols. Specifically, a deed restriction will be required tolimit access to site groundwater until the clean-up standardshave been met (18). Although the deed restriction is notintended to regulate site construction activities, it isintended to serve as a reminder and as a warning to any futuresite owners or developers of the existence of site contamination(19).

PREPARERS OF REPORT

A. ENVIRONMENTAL AND HEALTH EFFECTS ASSESSORS

David J. Borgeson, M.S.
Epidemiologist
Impact Assessment, Inc., Consultant to
Environmental Health Investigations Branch,
California Department of Health Services

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


B.COMMUNITY RELATIONS COORDINATOR

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


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 CaliforniaDepartment of Health Services under a cooperative agreement withthe Agency for Toxic Substances and Disease Registry (ATSDR). Itis in accordance with approved methodology and proceduresexisting 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, hasreviewed this health assessment and concurs with its findings.

Director, DHAC, ATSDR


REFERENCES

  1. Engineering-Science, Inc. Final Draft Remedial Investigationand Feasibility Study (RI/FS) for the Advanced Micro Devices(AMD) Building 915, Sunnyvale, California, February 1991.

  2. Preliminary Public health assessment for Advanced MicroDevices, Inc. (Building 915), Cerclis No. CAT080034234.Sunnyvale, Santa Clara County, California, August 27,1990.

  3. Harding Lawson Associates, Engineering-Science, Inc., EmconAssociates, and Weiss Associates. Draft RemedialInvestigation Report. A Report prepared for Advanced MicroDevices, Siegnetics Company, and TRW, Incorporated. TheCompanies, Sunnyvale, California. February 15, 1990.

  4. Senior Environmental Engineer, AMD, personal communication.

  5. Engineering-Science, Inc. First Quarter Groundwater Samplingand Analysis Report, AMD Building 915. March 1990.

  6. Engineering-Science, Inc. Second Quarter GroundwaterSampling and Analysis Report, AMD Building 915. June 1990.

  7. Engineering-Science, Inc. Third Quarter Groundwater Samplingand Analysis Report, AMD Building 915. September 1990.

  8. Engineering-Science, Inc. Fourth Quarter GroundwaterSampling and Analysis Report, AMD Building 915. November 1990.

  9. Engineering-Science, Inc. First Quarter Groundwater Samplingand Analysis Report, AMD Building 915. March 1991.

  10. California Regional Water Quality Control Board, SanFrancisco Bay Region, Fact Sheet 2, Advanced Micro Devices,Inc., Building 915 Superfund Site, Sunnyvale, California, March 1991.

  11. Weiss Associates. Possible Well Locations--Selected Parts ofSanta Clara Valley, California, 1986.

  12. Department of Health Services. Cancer incidence andmortality. California, 1988. California Health and Welfare Agency, 1991.

  13. Draft Public Health Assessment for Advanced Micro Devices,Inc. (Buildings 901/902), Cerclis No. CAD048634059. Sunnyvale, Santa Clara County, California, March 1991.

  14. California Water Quality Control Board, San Francisco BayRegion, Community Relations Plan for Superfund Sites in theCity of: Sunnyvale, January 1990.

  15. AMD 915 Project Manager, Engineering-Science, personalcommunication.

  16. Emissions calculations for AMD 915 facility for AB2588, AirResources Board, 1988.

  17. Results of air stripper source test. In letter from AcurexCorporation to Advanced Micro Devices, September 9, 1991.

  18. U.S. Environmental Protection Agency, Region IX. Record ofDecision for Advanced Micro Devices #915 Superfund Site,Sunnyvale, California, August 26, 1991.

  19. California Regional Water Quality Control Board, SanFrancisco Bay Region, Comments on Draft Health Assessmentfor Advanced Micro Devices building 915, December 24, 1991.

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