United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R09-89/032
June 1969
£EPA
Superfund
Record of Decision
Raytheon, CA
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Sb272-101
1 REPORT DOCUMENTATION i. REPORT NO.
PAGE EPA/ROD/R09-89/032
r^TWeendSuMMe
MfcuPERFUND RECORD OF DECISION
^HKaytheon, CA
First Remedial Action
7. Authors)
9. Performing Org*Jnua«on Nune end Addreee
12. Sponsoring Orgenlzitlon Neme and Addreee
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
18. Abemct(Umte200worde)
The Raytheon site is one of three Superfund s:
concurrently. The other two are Fairchild Senu
View Plant) . The sites are located in the Midc
Santa Clara County in the city of Mountain Viev
^^rimarily light industrial and commercial, wit*
^Btural surface drainage features within or sui
^Intercepted by a storm drain system and dischai
industrial activities were conducted in the vie
manufacturing, metal finishing operations, pai
other activities requiring the use, storage, ar
particularly solvents . Site investigations at
and 1982 revealed significant contamination by
and ground water. The primary causes of the cc
and lines, and poor management practices. Befc
investigations, which were conducted under a 1!
activities were conducted at the site by Faircl
actions included tank removals, soil removal at
(See Attached Sheet)
17. Document Aneryet* s. Descriptor*
Record of Decision - Raytheon, CA
First Remedial Action
Contaminated Media: soil, gw
Key Contaminants: VOCs (PCE, TCE, TCA, tolu
b. IdontHlera/Open-Endod Terms
tjATt Held/Croup
nMty Statement
2. 3. Recipient's Acceeeion No.
S. Report 0«t»
06/09/89
*.
S. Performing Orguriatlon Rept No.
10. ProlMtfTMk/WocfcUnHNo.
11. C«ttncl(C)orGr*nt(a)No.
(C)
(0)
IX Typ» of Report 4 Period Cowed
800/000
14.
ttes that are being remediated
iconductor (Mt. View) and Intel (Mountain
ilefield/Ellis/Whisman (MEW) Study Area in
i, California. Land use in the area is
i some residential areas. There are no
rrounding the site; most of the runoff is
:ged to an off site creek. Various
:inity of the site including semiconductor
:ts cleaning, aircraft maintenance, and
id handling of a variety of chemicals,
several of these facilities during 1981
toxic chemicals, primarily VOCs, in soil
sntamination were leaking storage tanks
jre and during additional site
385 Consent Order, interim cleanup
aild, Intel, and Raytheon. Cleanup
id treatment, well sealing, construction
ene, xylenes) , organics (phenols)
19. Security CU«. (Thta Report) 21. No.o(P»ge«
None 95
20. Security d*m (Thte Pige) 22. Price
None
(See ANSVZM.18)
See Instruction* on H»v*nt
OPTIONAL FORM 272 (4-77)
(Formerty NTIS-OS)
Department of Commerce
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EPA/ROD/R09-89/032
Raytheon, CA
First Remedial Action
16. Abstract (Continued)
of slurry walls, and hydraulic control and treatment of local ground water. The primary
contaminants of concern affecting the site are VOCs including PCE, TCE, TCA, toluene,
and xylenes; and other organics including phenols.
The selected remedy for this site includes in situ vapor extraction with treatment by
vapor phase GAC of contaminated soil found within the Fairchild and Raytheon slurry
walls. There may be some limited soil excavation and treatment by aeration for some
areas outside of the slurry walls, with onsite disposal of residues in the excavated
area; ground water pumping and treatment using air stripping, and in some cases liquid
phase GAC, with emissions controls consisting of GAC vapor phase carbon units, followed
by reuse of the ground water (reuse options including reinjection are being developed)
and, if necessary, discharge to surface water; sealing of any conduits or potential
conduits to protect the deep aquifer; and ground water monitoring. The present worth
cost for this remedial action is $49,000,000 to 56,000,000, which includes O&M costs.
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FAIRCHILD, INTEL. AND RAYTHEON SITES
MIDDLEFIELD/ELLIS/WHISMAN (MEW) STUDY AREA
MOUNTAIN VIEW, CALIFORNIA
RECORD OF DECISION
United States Environmental Protection Agency
Region DC - San Francisco. California
June 9. 1989
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JA1RC3ILD, XMT1L, AMD RAYTHZOM SITZS
MXDDLB7XZLD/ZLLZ8/WHXBMAM (KZW) ITTJOT
MOOKTAJM VIEW,
BBCORO OF DBCZ0ZOV
Unitad Seat** Bxrrlroox«nt«l Proccetioa
l«gi0B ZZ -- S*n rraneiaco, California
May 19S9
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EBOOBD OF D1CISIOW
fltBLB OF COWOann
SECTION PAGE;
Table of Contents i
Table of Figures and Tables ii
Declaration iii
1.0 Site Location and Description 1
2.0 Site History 2
3.0 Enforcement 3
4.0 Community Relations 4
5.0 Decision Scope 4
€.0 Nature and Extent of Contamination 5
7.0 Baseline Site Risks 6
8.0 Changes to the Proposed Plan 8
9.0 Description of Alternatives 9
10.0 ARARs 14
11.0 Other Criteria Considered 18
12.0 Summary of Alternatives Analysis 21
13.0 The Selected Remedy 22
14.0 Statutory Determinations 24
— Attachments —
Administrative Record Index
Responsiveness Summary
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UCOftD 07 DBCISIOM
TABLB 07 COHTOTTfl
•- Figures —
>uTNG PAGE
1-1 --- Sit* Location 1
1-2 — Building Occupants 1
6-1 — Location of MEW Plum* 5
9-1 — Schematic of Subsurface Zones 9
— Tables —
6-1 —• Chemicals of Concern 5
10-1 — Federal and State Groundvatar Standards 15
11-1 — Groundvater Criteria To Be Considered 19
12-1 Criteria for the Evaluation . 21
of Remedial Alternatives
ii
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S1CORD 07 D1CIBTOM
D1CIARATIOM
Site Hnmit and Location
Fairchild, Intel and Raytheon Sites, Middlefield/Bllis/Whisman
(MEW) study Area, Mountain View, California
Statement of Basis and Purpose?
This decision document presents the selected soil and groundwater
remedial actions for the Fairchild, Intel, and Raytheon National
Priority List (NPL) Sites in the Middlefield/Ellis/Whisman (MEW)
Study Area of Mountain View, California. The selected remedial
actions will also apply to the area-vide groundwater
contamination and to other areas of soil contamination in the MEW
Study Area, as appropriate. The remedial actions have been
developed in accordance with the Comprehensive Environmental
Response, Liability, and Compensation Act (CERCLA), as amended by
the Superfund Amendments and Reauthorization Act (SARA), and, to
the maximum extent practicable, the National Contingency Plan
(NCP). This decision is based upon the administrative record for
this site. The attached index identifies the items which comprise
the administrative record upon which the selection of the
remedial actions are based.
Description of the Remedies
The selected soil remedy is in-situ vapor extraction with
treatment by vapor phase granular activated carbon, and
excavation with treatment by aeration. Most of the vapor
extraction will taJce place within the existing Fairchild and
Raytheon slurry walls which contain the bulk of the site soil
contamination. Several smaller areas outside of the slurry walls
will also be remediated by in-situ vapor extraction. The cleanup
goals for soils are 1 part per million (ppm) trichloroethene
(TCE) inside the slurry walls and 0.5 ppm TCE outside of the
slurry walls. The soil cleanup goal is based on the amount of
contamination that can remain in the soil and still maintain the
groundwater cleanup goal in the shallow aquifers (outside the
slurry walls). Further explanation of the different cleanup goals
is provided on page 22 of this document, in Section 13 on The
Selected Remedies«
The groundwater remedy is extraction and treatment. Extracted
groundwater will be treated by air stripping towers. Airborne
emissions will meet all Bay Area Air Quality Management District
emission standards. It is anticipated that emission controls by
granular activated carbon will be required once the full remedy
is implemented. The extracted groundwater will be reused to the
iii
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aaxinua extant feasible, with a goal of 100% reuse, extracted
vatar which cannot be reused will ba dlachargad to local atraaas.
Allowable discharges to local atraaaa will ba ragulatad by the
National Pollutant Oiacharga Elimination Syatan (NPDES) of tha
Claan Watar Act.
Tha groundvatar claanup goal* ara 5 part* par billion (ppb) TCE
for tha anallow aquifars (which ara not currently used for
drinJcing water) and 0.8 ppb TCE for the deep aquifers which ara
used for drinJcing water. Attainment of these levels will also
assure cleanup of the other volatile organic compounds to at
least their respective Maxinua Contaminant Levels (MCLs). The
shallow aquifer cleanup goals also apply to the aquifars inside
the slurry walls.
The remedy includes the identification and sealing of any
potential conduit wells. Several abandoned agriculture walls
which acted as conduits for contamination to migrate from the
shallow aquifers to the deep aquifers have already been sealed.
Additional wells have been identified for sealing and others may
be identified which will also require sealing.
The remedy also includes maintaining inward and upward hydraulic
gradients (by pumping and treatment) inside the slurry walls and
regular monitoring of aquifars within and adjacent to the slurry
walls to monitor the integrity of each slurry wall system-.
Maintaining inward and upward hydraulic gradients will control
contaminants from escaping due to slurry wall failure. Selected
wells will be monitored for chemical concentrations and water
levels.
The soil remedy is expected to be in operation between 1 to 6
years. The groundwater remedy for the shallow aquifars may be in
operation for as long as 46 years or into the indefinite future,
because of the physical and chemical nature of the aquifars. The
groundwater remedy for the deep aquifars is estimated to be in
operation for at least 2 years and possibly as long as 45 years.
There will be regular monitoring of the groundwatar and slurry
vails during the life of the remedy.
iv
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Declaration
The selected remedies arc protective of human health and the
environaent, attain Federal and State requirements that are
applicable or relevant and appropriate to the remedial actions,
and are cost-effective. With respect to contamination in
groundvater and soil, the statutory preference for remedies that
employ treatment, reduce toxicity, mobility or volume as a
principal element, and utilize permanent solutions and
alternative treatment technologies to the maximum extent
practicable is satisfied.
Because of the anticipated length of time to achieve the cleanup
goals and the uncertainty whether the cleanup goals can be
achieved, both the technologies and the cleanup goals will be
reassessed every 5 years.
iel
Danel W. McGovern
Regional Administrator
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UCOBD OF DBCX8XOV
DICXSIOM SU1OCXAT
1.0 SITE LQCATTOM AND DESCRIPTION
The Middlefield/Ellis/Whisaan (MEW) Study Area i» located in
Santa Clara County in the city of Mountain View, California.
The site is divided into a Local Study Area (LSA) and a Regional
Study Area (RSA). Figure 1-1 identifies the LSA and RSA, along
with local roads and landaarks. The LSA consists of three
National Priority List (NPL) sites (Fairchild, Intel and
Raytheon), as veil as several non-Superfund sites. The LSA
encoapasses about 1/2 square aile of the RSA and contains
priaarily light industrial and coaaercial areas, with soae
residential areas vest of Whisaan Road. The RSA encompasses
approximately 8 square ailes and includes Moffett Naval Air
Station (an NPL site) and NASA Ames Research Center, along with
light industrial, coaaercial, agricultural, park, golf course,
undeveloped land, residential, motel and school land uses.
Various owners or occupants in the area around the intersections
of Middlefield Road, Ellis Street, Whisaan Road, and the Bayshore
Freeway (U.S. Highway 101), are or were involved in the
manufacture of semiconductors, metal finishing operations, parts
cleaning, aircraft maintenance, and other activities requiring
the use of a variety of chemicals. Local facilities with current
occupants are presented on Figure 1-2. Site investigations at
several of these facilities have revealed the presence of toxic
chemicals in the subsurface soils and groundwater. To investigate
the extent of groundwater contamination emanating froa the LSA,
and soil contamination at their respective facilities, Fairchild,
Intel, and Raytheon performed a Remedial Investigation and a
Feasibility Study of potential remedial alternatives under the
direction of EPA.
There are no natural surface drainage features within the Local
Study Area. The nearest significant natural surface drainage
features of the Regional Study Area are Stevens Creek to the vest
and Calabazas Creek to the east. Calabazas Creek is located
approximately four ailes east of the MEW Study Area. Stevens
Creek forms the western boundary of the Regional Study Area. Both
discharge into the San Francisco Bay. Surface water runoff from
aost of the RSA and all of the LSA south of the Bayshore Freeway
is intercepted by a storm drain systea and is discharged into
Stevens Creek. To the north of the Bayshore Freeway, aost of- the
runoff froa Moffett Field Naval Air Station is collected by a
storm drain systea that ultimately discharges to Guadalupe Slough
of San Francisco Bay. Runoff froa the northwestern portion of
Moffett Field discharges into Stevens Creek.
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v LIMITS OF
-— O ff /* i /•TVfVi—
MOFFETT
FIELD
MOUNTAIN VICV* CALIFORNIA
- ELLIS- WHISMAN AREA
SIU Location
Flgurt 1-1
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BUILDING OCCUPANTS
MOUNTAIN V€W. CALIFORNIA
Flgur* 1-2
MIOOLfFlEU>-EU.I3-MM3MAN AREA
sesuFM
•M $MmB]
lorUHMB
| « on-
itn
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The Local and Regional Study Areas are underlain by a thick
sequence of unconsolidated sediments deposited into a structural
depression. The sediments are coaprised of alluvial fan,
estuarine, and bay mud deposits. Repeated.variations in s«a
levels resulted in a complex sedimentary sequence characterized
by irregular interbedding and interfingering of coarse and fine
grained deposits.
Groundwater aquifers at the site are subdivided into shallow and
deep aquifer systeas, separated by a laterally extensive regional
aquitard. The shallow aquifer systea comprises aquifers and
aquitards to a depth of approximately 160 feet: below the surface.
Within the shallow systea four priaary hydrogeologic aquifer
zones have been identified based upon the occurrence of aquifer
• material and a siailar depth below the surface. The shallow
aquifer systea is comprised of the A-aqulfer and the underlying
B1-, B2- and B3- aquifers. The regional B-C aquitard separates
the B3-aquifers froa the C-aquifer and the deep aquifer system.
Current groundwater flow in aquifer zones above the B-C aquitard
is generally to the north, toward San Francisco Bay.
2.0 SITE HTSTQRY
During 1981 and 1982, preliminary investigations of facilities
within the LSA indicated significant concentrations of
contaainants in soil and groundwater. By 1984, the Fairchild,
Intel and Raytheon sites, located within the LSA, were proposed
for the Federal National Priorities List (NPL). By 1985, five
companies within the LSA (Fairchild, Intel, Raytheon, NEC, and
Siltec) initiated a joint investigation to document and
characterize the distribution of chemicals eaanating froa their
facilities. In April 1985, the California Regional Water Quality
Control Board - San Francisco Bay Region (RWQCB) adopted Waste
Discharge Requirements (WDRs) for each of the five companies. The
primary cause of the subsurface contaaination was froa leaking
storage tanks and lines, and poor waste management practices.
On August 15, 1985, Fairchild, Intel, and Raytheon entered into a
Consent Order with the EPA, the RWQCB, and the California
Department of Health Services (DBS). Since signing of the Consent
Order, the three coapanies have carried out an extensive Reaedial
Investigation and Feasibility Study (RI/FS) of chemicals
emanating froa the LSA and soil contaaination at their respective
facilities. Work has been performed under the supervision of EPA,
the RWQCB, DHS, and the Santa Clara Valley Water District
(SCVWD). Prior to and during the site investigation, the
coapanies have been conducting interia clean up activities at the
site. These interia reaedial actions include tank removals, soil
removal and treatment, well sealing, construction of slurry
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walla, and hydraulic control and treatment of local groundwatar.
NEC and Siltac declined to enter into the Concent Order and were
placed under RWQCB enforcement authority.
The three coapaniee followed an approved Quality Assurance and
Quality Control (QA/QC) Plan and approved Sampling Plane. Zn
addition, eplit samples were collected by EPA froa aelected walls
and these result* were compared with the companies' eaapling
results. EPA determined that the companies* data quality was
adequate for the purpose of the RI/FS.
The MEW Remedial Investigation Report was concluded in July,
1988. The draft Feasibility Study and EPA's Proposed Plan were
presented to the community for review and public comment in
November, 1988. In May 1989, Special Notice letters for the
Remedial Design/Remedial Action (RO/RA) Consent Decree were sant
out to the five (5) original companies and twelve (12) other
Potentially Responsible Parties (PRPs).
3.0 ENFORCEMENT
The Regional Water Quality Control Board - San Francisco Bay
Region (RWQCB) was the lead agency until April 1985, when the
Board referred the five companies to EPA for cleanup under
Superfund. In May, 1985, EPA sent general notice letters,
pursuant to Section 106 of CERCLA, to the five companies. NEC and
Siltec chose not to participate in the RI/FS negotiations and
were referred back to the RWQCB. Zn August 1985, Fairchild,
Intel, and Raytheon signed an Administrative Order on Consent
with EPA, to conduct an RI/FS of the MEW area. The RWQCB and
California Department of Health Services were cosignees of the
Consent Order.
The Consent Order and WorJc Plan called for a comprehensive
groundwater investigation of the MEW area and site specific
(source) investigation at Fairchild, Zntal, and Raytheon. The
RWQCB issued Waste Discharge Requirements (WDRs) for NEC and
Siltec which paralleled the Consent Order schedule and
requirements.
During the course of the RZ/FS, EPA gathered new information and
evaluated existing information concerning other PRPs.
During December 1987 and January 1988, EPA issued twenty-four
(24) RCRA 3007/CERCLA 104 information request letters to various
other parties in the MEW area. Zn July 1988, SPA issued a RCRA
3013 Unilateral Order to GTE to begin an investigation of its
property, to determine if the company had contributed to the MEW
groundwater plume. After evaluating the 3007/104 response
letters, EPA sent General Notice Letters to seventeen (17) PRPs
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in September 1988. An initial PRP meeting vac sponsored by EPA in
October 1988, to explain the Superfund process to the noticed
PRPs. EPA issued seven (7) additional General Notice and/or
information request letters in March 1989. EPA subsequently
issued Special Notice Letters for conducting the selected
reaedies in May 1989.
4.0 eOMMONITY MIATTOMS
The coaaent period for the Proposed Plan opened Noveaber 21,
1988, and closed January 23, 1989. A public meeting was held on
December 14, 1988 at the Crittenden Middle School in Mountain
View and was attended by approximately 75 people.
Prior to the beginning of the public conaent period, EPA
published notices in "The View**, "The Los Altos Town Crier", "The
Tiaes Tribune", and the "San Jose Mercury News** (Peninsula Extra
Edition). The notices briefly described the Proposed Plan and
announced the public coaaent period and the public aeeting. The
notice also announced the availability of the Proposed Plan for
review at the information repository established at the Mountain
View Public Library.
A fact sheet describing the Proposed Plan was delivered to the
Mountain View Public Library in Noveaber, 1988. Copies of the
fact sheet were also Bailed in November, 1988 to EPA's MEW
Bailing list, which contains members of the- general public,
elected officials, and PRPs.
In addition, EPA held several worJcshops and briefings-in November
and December, 1988 for various community groups, the Mountain
View city Council, and the Santa Clara County Board of
Supervisors. The workshops were used to brief community groups
and elected officials on the results of the MEW RI/FS and to
describe EPA's proposed reaedial alternatives.
EPA has prepared the attached response summary, which provides
Agency responses to coaaents submitted in writing during the
public coaaent period. Also attached is a transcript of the
proceedings of the Deceaber 14, 1988 coaaunity meeting.
5.0 DECISION SCOPE
As discussed in the Declaration and Site History, the selected
reaedial actions that are presented in this decision document are
designed to protect the local drinking water supplies, restore
the -shallow, and deep aquifers to Beet MCLs and a 10** risk level
respectively, control and remediate contamination in subsurface
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•oils, and prevent vertical migration of contamination in the
aquifers. The difference in decision on cleanup goals for the
shallow and deep aquifers is provided on page 22 of this
docuaent, in Section 13 on Tha s«l acted
The reaedial actions, pumping and treating groundvater and
conduit sealing, will address the area-vide groundvater
contamination. The reaedial actions, in-situ soil vapor
extraction, and excavation and treatment vill address soil
contamination at the Fair-child, Intel, and Raytheon NPL sites and
other areas' of soil contamination identified in the MEW study
Area.
6.0 MATURE AND EXTENT OF CONTAMINATION
Industrial activities conducted within the MEW Study Area
required the storage, handling and use of a large number of
chemicals, particularly solvents and other chemicals used in a
variety of manufacturing processes. Significant quantities of
volatile organic chemicals vere used for decreasing, process
operations, and for general maintenance. Raw and waste solvents
and other chemicals were piped and stored in underground systems .
The presence of chemicals in the subsurface soils and
groundwater, that originated from facilities in the MEW area, are
primarily the result of leaks from these subsurface tanks and
lines, sumps, chemical handling and storage areas, and utility
corridors. Chemical releases occurred, for the most part, below
the ground surface and migrated downward into the aquifer system.
Investigations at the site have revealed the presence of over 70
compounds in groundwater, surface water, sediments, and
subsurface soils. The vast majority and quantity of these
compounds are found in groundwater and subsurface soils. Three
major classes of chemicals were investigated during the RI: (1)
volatile organic compounds, (2) semi-volatile acid and
base/neutral extract able organic compounds, and (3) priority
pollutant metals. Of these three classes, volatile organics are
the most prevalent. Table 6-1 presents chemicals of concern,
frequency of defection, and maximum concentrations.
An extensive area of groundwater contamination has been defined
in the RI and is presented in Figure 6-1. Current site data
indicate that chemicals are present primarily in the A-, B1-, and
B2-aquifer zones. To a much lesser degree, chemicals have been
detected in localized areas of the B3-, C-aquifer, and deeper
aquifer zones. Contamination of the C-aquifer and deeper aquifers
appears to have resulted from chemicals migrating downward from
shallow areas containing elevated chemical concentrations,
through conduit wells, into groundwater of the deep aquifer
system. The C and Deep aquifers most affected by contamination
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Chemical
TABLE 6-1
CHEMICALS OF CONCERN
JUDDLEFIELD/ELLIS/WHISMAN STUDY AREA
Frequency of
Detection*
Geometric Mean Maximum
Concentration" Concentration6
(*g/liter) (*g/liter)
Organ iqa
Chloroform
1 , 2-Dichlorobenzene
1 , 1-Dichloroethane
1, 1-Dichloroethene
1 , 2-Dichloroethene
Freon-113
Phenol
Tetrachloroethene . .
1, 1, 1-Trichloroe thane
Trichloroethene
Vinyl Chloride
Inorganics
Antimony
Cadmium
Arsenic
Lead
71/384
13/384
98/384
133/384
200/384
181/384
21/273
64/384
184/384
278/384
17/384
15/205
26/205
34/292
44/292
0.002
0.003
0.005
0.006
0.030
0.009
0.002
0.003
0.017
0.175
0.008
0.052
0.006
0.004
0.002
3.3
5.2
10.0
20.0
330.0
46.0
50.0
3.7
420.0
1000.0
25.0
0.600
0.050
0.040
0.043
a/ Values for organic* are number of detects/number of samples
for the fourth round of groundvater campling. Values for
inorganics are the number of detects/number of veil sampled
for dissolved metals.
b/ Values reported are for all groundvater samples for each
chemical.
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Showing
TCE OMp Aqua* contairtnattan
Location of MEW Plume
Figure 6-1
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are in the areas of the so-called Rezendes Wells, located near
Fairchild Building 20, and the Silva Well, located at 42 Sherland
Avenue. These wells have subsequently been sealed. The closest
Municipal water supply well, Mountain View 118 (MV 18), is
located approximately 1800 feet to the southwest of the Silva
Well. Groundwater sanples are collected front MV 18 on a regular
basis. No contaainants have been identified in any water samples
froa MV 18. As part of the Remedial Design and Remedial Action
(RD/RA) soae additional groundwatar investigations pay be
necessary, particularly in the Silva Well area.
Subsurface soil contamination has been found at the Fairchild,
Intel, and Raytheon facilities, along with the facilities of
other PRPs within the RSA. Trichloroethene (TCZ), 1,1,1-
trichloroethane (TCA), trichlorotrifluoroethane (Freon-113), 1,1-
dichloroethene (1,1-DCZ), 1,2-dichloroethene (1,2-DCE), aethylene
chloride, toluene, acetone, and xylene are the cheaicals most
commonly detected in subsurface soils in the LSA. Cheaicals
associated with activities in the RSA appear to b* concentrated
in shallow soils above approximately 50 feet or roughly extending
to the Bl-aquifer. Cheaicals are'not found in surface soil
samples (upper one foot of soil) and do not appear in soils and
clay of the B-C aquitard. Chemical found in subsurface soil
samples are generally similar to those found in adjacent
groundwatar samples. As part of the Remedial Design and Remedial
Action some additional soil investigations may be necessary in
certain areas.
7.0 BASELINE SITE RISKS
An Endangeraent Assessment prepared by EPA as part of the RI/FS
was used to evaluate the ramifications of the no-action remedial
alternative and to determine if an actual or threatened release
of a hazardous substance froa the site may present an imminent or
substantial endangerment to public health, welfare, or the
environment.
Large areas of the site are contaminated. The bulk of the
contamination is present in groundwater and subsurface soils.
Investigations at the site have revealed the presence of over 70
compounds. Because of the large number of cheaicals detected at
the site, a selection process was used to determine the cheaicals
of primary concern at the site. The organic cheaicals that were
selected are: trichloroethylene, 1,1,1,-trichloroethane, vinyl
chloride, 1,1-dichlproethane, l-,l-dichloroethylen«, 1,2-
dichloroethylene (cis and trans isomers), dichlorobenxene,
chloroform, Freon 113, tetrachloroethylens, and phenol. Metals
were detected infrequently. Overall metals are of less concern at
the site that the volatile organic cheaicals. Several of the
selected contaainants (trichloroethylene, chloroform.
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dichlorobenzene, tetrachloroethylene) have been shown to b«
carcinogenic in animals and have been classified by EPA as
possible or probable human carcinogens. Vinyl chloride is a known
huaan carcinogen. The other contaminants have been shown to cause
systemic toxicity under certain exposure conditions.
The results of the Endangeraent Assessment indicate that exposure
to contaminated groundwater poses the greatest public health
concern. Risks to public health were estimated by combining
information on exposure at possible exposure points with toxic
potency of the groundwater contaminants. Drinking water from
hypothetical wells to the west of Nhisman Road for a lifetime
would be associated with an upperbound excess lifetime cancer
risk of 6(10)*s (average case) and 2(10)** (maximum case).
Drinking water from a well to the north of the LSA in the A-
aquifer would be associated with an upperbound excess lifetime
cancer risk of 9(10)** (average case) and 4(10)** (maximum case).
Drinking water from a Bl-aquifer well in the same area would pose
an upperbound excess lifetime cancer risk of 1(10)"2 (average
case) and 5(10)*2 (maximum case). In addition, estimated intake
of noncarcinogenic compounds from groundwater at these locations
would exceed reference dose levels (RfDs).
Contaminants are not present at elevated levels in exposed
surface soils. Consequently, substantial exposure via direct
contact with contaminated soils or via inhalation of volatile
compounds from soil or contaminated fugitive dust is considered
unlikely under current land-use conditions. If redevelopment of
the site was to occur for residential or other uses, significant
exposure to contaminants can occur if localized areas of
contamination remained uncovered. Short-term excavation
activities at the site could lead to inhalation of volatile
organic compounds or contaminated fugitive dust, but exposure
would probably be of short duration and frequency, and therefore
would not pose a significant public health concern.
Low concentration-levels of several chemicals were detected in
Stevens Creek, at the western boundary of the RSA. Any exposure
to these chemicals would probably be of short duration and
frequency, and therefore the risk would be negligible.
The Endangeraent Assessment also indicates that "environmental"
(flora and fauna) exposure to chemicals from the MEW site is
negligible.
In summary, the results of the baseline risk assessment for the
no-action alternative indicate that exposure to contaminants in
groundwater poses the greatest potential public health concern.
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8.0 CHANCgS TO THg PROPOSED PIAM
1. The Proposed Plan identifies vapor extraction as the
preferred alternative to addreas contaainatad aoila.
However, because aoil excavation and traataant by
aaration has baan effectively iapleaented at MEW in tha
past (at Zntal), and othar pRPs have expressed intarast
in exploring this altarnativa for thair sites, tha
salactad reaedy for soils will also allow soil
axeavation to ba iapleaented, providad federal, state,
and local air standards can ba »at. In addition to
local air standards, Bast Oaaonstratad Availabla
Tachnology (BOAT) traataant standards aay also ba
required depending upon how tha axcavatad soil is
handlad. Tha addition of soil axeavation and traataant
by aaration allows flexibility during tha RD/RA phasas
for othar PRPs to usa a cost affaetiva altarnativa for
thair particular sitas whila also protaeting huaan
haalth arid tha anvironaant. Soil axeavation and
traataant by aaration would aost likely ba> suitabla for
saall loealizad araas of contaaination.
2. Tha Proposad Plan appaars to ba aabiguous in tha
claanup goal for aquifars within the- slurry walls.
Whila tha Proposad Plan claanup goal for tha shallow •
aquifars is 5 ppb for TCZ, howavar, tha plan also
statas that tha shallow aquifar zona is dafinad as
thosa shallow aquifars locatad outsida tha slurry
walls.
Although tha aquifars confinad by tha slurry walls ara
disconnectad froa tha outsida aquifars (whan hydraulic
control is aaintainad by pumping aquifars insida tha
slurry walls) a elaanup goal of 5 ppb for TCS (tha MCL)
will also ba established for aquifars insida tha slurry
walls. This goal is aora protective of tha public
health and tha environment and is consistent with
cleanup goals set by tha RWQCB for another site in
Santa Clara Valley.
3. Identification and sealing of potential conduits was
discussed in text of tha Feasibility Study (FS) and in
Appendix L of tha FS, but not specifically noted in EPA's
Proposad Plan. Potential conduits will be identified,
evaluated, and sealed if necessary.
8
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9.0 DESCRIPTION OF ALTERNATIVES
The MEW Feasibility study identified an array of remediation
technologies that verm potentially applicable and then screened
those technologies based on their applicability to site
characteristics, compatibility with site-specific chemicals, and
anticipated performance. After the technology screening process,
alternatives were formulated using combinations of feasible
technologies that are capable of meeting remedial objectives.
These alternatives were evaluated based on their public health
and environmental impacts and on order of magnitude cost
considerations. The short- and long-term effectiveness of each
alternative was also assessed. After this initial screening of
remedial alternatives, a detailed analysis of the selected
alternatives was performed. This section of the Record of
Decision will present the alternatives evaluated in the detailed
analysis of remedial alternatives.
To evaluate the remedial alternatives, the MEW Study Area was
divided into five subsurface zones, as show in Figure 9-1. The
first subsurface zone (Zone 1, the "cohesive shallow layer")
consists of soil stratum that begins at the ground surface and
extends to the water table. The upper foot of the cohesive
shallow layer is not included in the analysis of alternatives
based upon the conclusion set forth in the Endangerment
Assessment that there are no health risks from exposure to
surface soils. The second subsurface zone (Zone 2A, the
•unsaturated disconnected aquifers") consists of the unsaturated
zone within the area bounded by the existing slurry walls. The
Fairchild slurry walls extend into the A/B aquitard. The Raytheon
slurry wall extends through the A/B and B1/B2 aquitards and into
the B2 aquifer. The third subsurface zone (Zone 2B, the
"saturated disconnected aquifers") consists of the saturated zone
within the slurry walls. The fourth subsurface zone (Zone 3, the
"shallow aquifers") consists of the shallow aquifer system
outside of the slurry walls. The fifth subsurface zone (Zone 4,
the "deep aquifers") consists of the C-aquifer and deeper aquifer
zones.
The range of potential remedial alternatives are presented for
each subsurface zone: Zone 1 Soils; Zone 3 Shallow Aquifers; Zone
4 Deep Aquifers; and Zones 2A and 2B Slurry Wall System.
Zone 1 - Soils
Ho Further Action:
The Ho Action alternative serves as a "baseline* against which
other alternatives are compared. For soils, only soil monitoring
would be conducted, and all soil pilot study activities would be
discontinued.
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SURFACE LAYER
SLURRY WALL
ZONE 3
SLURRY WALL
CONFINING AQUITARO
'3-C' AOUITARD
ZONE 4
LEGEND:
GROUND WATER LEVEL
SLURRY WALL EXTENSION
THROUGH AQ'JITARO
ZONE DEFINITIONS:
COMC5IVC SHALLOW
OISCONNCCTCO
SHALLOW AQUIFERS
BEEP
SCHEMATIC OF SUBSURFACE
ZONES AT MEW SITE
SLURRY WALL
OBCONNCCTO AOUIFERS MOUNTAIN VIEW, CALIFORNIA
pftCPAftco ron
REMEDIAL INVESTIQAT10N/FEASIBIJTY STUDY
MIOOLEFJ ELD-ELLIS-WHISMAN AREA
Figure 9-1
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In-situ Vapor Extraction and Treatment:
Soil vapor extraction involves removing the volatile soil
contaminants without excavating the soil itself. This would b«
accoaplished by installing vapor extraction wells through which
air containing Volatile Organic Compounds (VOCs) is pumped from
the soil. Contaminants in the extracted air are then removed
using carbon treatment, if necessary, and the treated air is
released. The treatment process is designed to meet all
applicable air emission standards.
Partial Excavation and Ambient Temperature Aeration:
This alternative involves excavating and aerating the soil, which
causes the VOCs to volatilize. Treated soils are then placed back
in their original locations. The areas that would be excavated
are those with the highest level of contamination. Treatment by
ambient temperature aeration would be conducted inside a
controlled atmosphere enclosure where necessary. This enclosure
would prevent the migration of fugitive dust and chemicals vapors
from the treatment area. Chemical vapors would be captured by
activated carbon, if necessary. The primary disadvantages of this
alternative are that soils located under buildings and other
structures could not be excavated and. treatment of the air
emissions is difficult.
Partial Excavation and Ambient Temperature Aeration with In-Situ
Vapor Extraction:
This alternative involves a combination of the previous two
cleanup alternatives. Excavation and aeration would be used at
those soil contamination zones that are accessible. Vapor
extraction would be used for selected contamination zones that
are not easily accessible, such as soil contamination zones
located under buildings.
Zone 3 - Shallow Aquifers
Ho Further Action:
The No Action alternative for the shallow aquifers would involve
only groundvater monitoring; no additional cleanup activities
would be conducted.
Hydraulic Control by Groundwatar Extraction and Treatment:
This alternative Involves low-rate pumping of the affected
aquifers with monitoring of the plume, and represents the lowest
level of active restoration evaluated for the shallow groundwater
system. Recovery wells would be installed in appropriate
locations along the periphery of the plume. The extraction well
10
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would-operate at a puaping rate sufficient to insure that the
pluae would not expand laterally. Extracted groundwater would be
treated using air stripper-based treatment systems and vapor-
phase carbon adsorption (where necessary) which would be operated
under applicable alar and water quality requirements. The treated
water would be discharged to Stevens Creek via the storm sewer
systea. A network of monitoring wells would be used to determine
any changes in the extent of the pluae.
Hydraulic Remediation by Groundwater Extraction and Treataent:
This alternative involves puaping the affected aquifers at a rate
sufficient to achieve an accelerated reduction in the extent of
the pluae and reduction of chemical concentrations in the
groundwater. This alternative would also utilize a network of
monitoring wells to verify remediation progress. Extraction wells
would be installed in locations around the periphery and in the
plume. Extracted groundwater would be treated using air stripper-
based treatment systems and vapor-phase carbon adsorption if
necessary, which would be operated to meet applicable air
emission limitations. Treated water would be discharged to
Stevens Creek via tae stora sewer systea.
Vertical Iaperaeable) Barriers:
This alternative involves constructing a vertical iaperaeable
barrier around the entire MEW pluae, in order to hydraulically
isolate the shallow aquifers. This alternative would not result
in a permanent reduction of chemicals currently in the shallow
aquifer systea, unless implemented in conjunction with other
remedial alternatii
Zone 4 — Deeo
No Further Action:
The No Action alternative, which is used as a baseline for
evaluation of remedial alternatives, consists of monitoring the
existing groundwater pluae.
Hydraulic Remediation by Groundwatar Extraction and Treatment:
Elements of this alternative are described above for shallow
aquifers and are essentially the same for the deep aquifers.
Zone 2A — Uhsaturatsd Disconnected Aquifers fSlurry Wall. System)
No Further Action:
The No Action alternative involves no further treatment of Zone
2A soils, located within the area bounded by the existing slurry
walls. Under this alternative, the unsaturated disconnected
11
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aquifer •oil* would remain contained laterally by the slurry
cutoff walla. Long-term monitoring of vatar levels and cheaical
concentrations in th« saturated disconnected aquifara (Zona 2B)
and tha shallow aqulfar (Zona 3) water-bearing zones outaida
(beneath and around) tha alurry valla would b« raquirad to datact
aigration of cheaicals froa tha unsaturatad soil* within tha
alurry walls.
In-Situ Vapor Extraction:
This altamativa for raaadiation of tha unsaturatad disconnected
aguifar soils involvas aarating tha Zone 2A soils by vacuum
axtraction, traating tha extracted air in accordanca with
applicable air quality raquiramants. Extractad volatilas would
pass through an emission control systaa consisting of vapor-phase
carbon adsorption for raaoval of tha VOCs froa tha axtractad air
prior to discharge to tha ataosphara in accordanca with
appropriate air requirements. This alternative would also use
existing axtraction .walls to remove tha groundwatar necessary to
aaintain desired water levels. Tha extracted groundwatar would be
treated using air strippers or carbon adsorption to remove voc's
prior to discharge of tha extracted groundwatar to Stevens Creek.
Maintain Inward and Upward Gradients:
This alternative involves pumping limited quantities of
groundwater from the saturated portions' of tha aquifers within
the slurry walls. This process will aaintain a hydraulic gradient
inward across tha slurry walls and upward, thereby restricting
the movement of chemicals outward into tha shallow aquifer zone
(Zone 3). The use of hydraulic control in conjunction with the
slurry walls ensures that contaminates will be kept localized
(within tha confines of each slurry wall) and add an additional
level of protection if a slurry wall failure was to occur. The
conjunctive use of slurry walls and hydraulic control is referred
to as a slurry wall systaa. Tha extracted groundwater would be
treated using air stripping or carbon-adsorption prior to
discharge to Stevens Creek.
Flushing:
This alternative, for reaadiation of unsaturatad aquifers within
the slurry walls (Zona 2A), involves the extraction of water from
tha saturated soils, re-saturation of tha unsaturatad soils,
treatment of extracted groundwatar by air stripping, and
rainjaction of tha treated water into rasaturatad soils within
tha slurry walls. Tha unsaturatad soils would ba raaadiatad by
flushing using a network of water injection and axtraction wells.
Extractad groundwatar would ba treated by air stripping prior to
rainjaction through tha injection wall network.
12
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Partial Excavation and Ambient Temperature Aeration:
This alternative for 2A •oil* involves the partial excavation of
highly localized areas of cheaicals containing unsaturated
disconnected aquifer coils. Treatment by aabiant temperature
aeration would be conductad inside a controllad atmosphere
enclosure vhara necessary. This anclosura would pravant tha
•igration of fugitiva dust and chaaicals vapors froa tha
traatnant araa. Chaaical vapors would ba capturad by activated
carbon, if nacassary.
Zone 2B - Saturated Disconnected Aquifers fSlurry Wall Svatenl
No Purthar Action:
Tha No Action altamativa involvas no furthar traatnant of tha
containad soils or hydraulic gradiant control within tha araa
boundad by tha slurry walls. Long-tarn monitoring of watar levels
and chemical concentrations in tha saturated disconnected
aquifers (Zone 2B) and tha shallow aquifer (Zona 3) water-bearing
zones outside (beneath and around) the slurry walls would be
required to detect migration of cheaicals froa the unsaturated
soils within the slurry walls.
Zn-Situ Vapor Extraction With Oewataring:
This alternative for remediation of saturated aquifer soils
involves dewatering the aquifers within the area bounded by the
slurry walls, aerating the dawatared soil pore spaces by vacuum
extraction, treating tha extracted air, if required, with vapor-
phase carbon adsorption, treating the extracted groundwatar with
air stripping, and discharging the treated air and watar in
accordance with applicable air and watar quality requirements.
The extracted groundwatar would be treated using air strippers or
carbon adsorption to raaove VOCs prior to discharge of the
extracted groundwater to Stevens Creek.
Maintain Inward and Upward Hydraulic Gradients:
This hydraulic control alternative for saturated aquifers within
the slurry walls (Zona 2B), involves pumping relatively saall
quantities of watar froa within the slurry wall areas for the
purpose of lowering the interior water table to produce inward
and upward hydraulic gradients. The inward and upward hydraulic
gradients would preclude the outward migration of cheaicals
present with the zone contained by the slurry wall areas. The
saall quantities of groundwatar pumped froa within the slurry
walls would be treated using on-sita air stripper-based systems
or carbon adsorption, which would be operated in accordance with
applicable air and watar quality requirements. The required
monitoring for this alternative would be the same scope as that
13
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required under the "No Further Action" (monitoring only)
alternative.
Flushing:
This alternative for reaediation of saturated aquifers within the
slurry wall areas involves the extraction of water from the
saturated soils, treatment of extracted groundwater by air
stripping, and reinjection of the treated water into saturated
soils within the slurry walls. Extracted groundwater would be
treated using air strippers or carbon adsorption prior to
reinjection through the injection well network.
10.0 APPLICABLE Q^ P^I-FVANT AND APPROPRIATE REQUIREMENTS f ARARs)
Under Section 121 (d) of CERCLA, as amended by SARA, the selected
remedy must achieve a level or standard of cleanup that assures
protection of human health and the environment. In addition,
CERCLA requires that remedial actions achieve a level. or standard
of cleanup that meets legally applicable or relevant and
appropriate requirements, standards, criteria or limitations
(ARARs).
ARARs associated with the site have been generally separated into
three categories: (1) ambient or chemical specific requirements
that set health or risk-based concentration limits or ranges for
particular chemicals; (2) performance, design, or action-specific
requirements that govern particular activities; and (3) location-
specific requirements. For this site the selection of ARARs is
dependant on the defined beneficial use of groundwater as a
source of drinking water.
Beneficial Use of Local Groundwater as a Source of Drinking Water
The regulatory framework associated with the cleanup of
groundwater and soil at the site is driven by the beneficial
(current or potential) use of local groundwater. As stated in 40
CFR 300 of the Federal Register on page 51433 (December 21,
1988), "The goal of EPA's Superfund approach is to return usable
ground waters to their beneficial uses within a timeframe that is
reasonable*. Drinking water is considered to be the highest
beneficial use and affords the greatest level of protection and
cleanup.
As required- by the California Portor-Cologne Water Quality
Control Act, the Regional Water Quality Control Board - San
Francisco Bay Region defines the beneficial uses of various water
bodies in the greater San Francisco Bay Area. Water bodies and
their beneficial uses are presented in The San Francisco Basin
Plan. This regional plan has been promulgated and is an ARAR for
14
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this sit*. In the Basin Plan the Regional Board classifies the
shallow aquifers in the area of the MEW plume as a "potentially
suitable for municipal or domestic water supply". In addition,
the Basin Plan states that the "use of waters in the vicinity
represent the best information on beneficial uses". Currently,
the C and Deep aquifers at the site are used as a municipal
drinking water supply.
CHEMICAL-SPECIFIC ARAM
Chemical-specific ARARs for the MEW site are Federal and State of
California drinking water standards. Each is relevant and
appropriate to set cleanup standards at the site. A list of
Federal and State drinking water standards are presented in Table
10-1.
Federal Drinking Water Standards
Potential drinking water standards at the site include Maximum
Contaminant Level Goals (MCLGs) and Maximum Contaminant Levels
(MCLs) :
Rs stated in CERCLA Section 121 (d)(1), MCLGs are mentioned as
potential cleanup standards when these levels "are relevant and
appropriate under the circumstances". After weighing all factors,
EPA has determined that they are not relevant and appropriate for
the site.
The relevant and appropriate standards to establish groundwater
cleanup levels at the site are the Federal Maxlmtim Contaminant
Levels (MCLs), as presented under Safe Drinking Water Act. EPA
bases this decision on the fact that MCLs are fully protective of
human health and, for carcinogens, fall within the established
acceptable risk range of 10'4 to 10 . MCLs are ARARs for
groundwater at the site and are also used to establish soil
cleanup levels.
State Drinking Water Standards
California Drinking Water Standards establish enforceable limits
for substances that may affect health or aesthetic qualities of
water and apply to water delivered to customers. The state's
Primary Standards are based on federal National Interim Primary
Drinking Water Regulations. Currently, California has promulgated
MCLs for cadmium, arsenic and lead, and some) of the organics of
concern.
15
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TABLE 10-1
FEDERAL AND STATE GROUNDWATER STANDARDS
MIDDLEFIELD/ELLIS/WHISMAN STUDY AREA
Cheaical
Federal
Maximum Contaminant
Levels (MCLs)
(ag/liter)
State
MCLs
(mg/liter)
Oraaniea
Chiorofora
1,2-Diehlorobenzene
1,1-Dichloroethane
I,l-Diehloro«th«ne
1,2-Dichloroethene
Freon-113
Phenol
Tetrachloroethene
1,1,1-Trichloroethane
Trichloroethene
Vinyl Chloride
Inorganics
Antimony
Cadmium
Arsenic
Lead
0.100
0.007
0.200
0.005
0.002
0.010
0.050
0.050
0.006
0.200
0.005
0.0005
0.010
0.050
0.050
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ACTIOW SP1CITXC AJtAft*
Groundwater extraction and treatment involves pumping, treating,
and discharging the treated groundwatar and/or rain j act ing it
into the aquifer. Soil remediation can include excavation and/or
in-eitu treataent. with groundvatar treatment and in-aitu vapor
extraction, Volatile Organic Chemicals (VOCs) would be moved by
•ir stripping and/or Granular Activated Carbon (GAC) adsorption.
Air stripping requires consideration of ARARs tar VOC eaissions,
GAC use requires consideration of ARARs associated with carbon
regeneration or disposal, and discharge or reinjection Bust meet
specific ARARs.
Discharge to Surface Water
Substantive National Pollutant Discharge Elimination Systea
(NPDES) permit requireaents would apply to treated effluent
discharging to surface waters. These would primarily be effluent
limitations and monitoring requireaents. The RWQCB regulates
NPDES discharges. Ambient Hater Quality Criteria are used by the
State of California to set Water Quality Standards in the San
Francisco Bay Regional Basin Plan. Standards in the Basin Plan
are used by the RWQCB to aet NPDES effluent discharge
limitations.
Section 402 of the Clean Water .Act, as amended in 1987, will
result in the prohibition of discharge of non-storm waters to the
City of Mountain View storm sewer system by 1991.
Reinfection of Treated Effluent Into Aquifers
If treated groundwater is reinjacted, regulations governing
underground injection may apply. Specifically, the Federal Safe
Drinking Water Act requires an Underground Injection Control
(UIC) program. In California, the DIG program is administered by
U.S. EPA. The UIC program prohibits treated effluent from being
injected, into or above a source of drinJcing water. Except when
it is pursuant to a CZRCLA cleanup UIC regulations do not
regulate the concentration of constituents, rather they regulate
only the method and location of the injection. These. Federal
requirements regarding injection may be "relevant: and
appropriate* to the site.
Federal RCRA requirements and the State's Toxic Injection Well
Control Act of 1985 (Cal. Health « Safety Code Section 25159.10
£& IfliLJ might also be "relevant and appropriate" to the
reinfection of treated groundwater.
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Dlgeharoa to Sanitary Sewers
Discharge of treated groundwater to the local sanitary fever
systea requires coapliance with the City's of Mountain View's
Industrial Waste Ordinance and the Clean Water Act Pretreataent
Standards. The City's Ordinance sets forth effluent quantity and
discharge concentration limits, along with standards for
•onitoring and reporting. Substantive requireaents are "legally
applicable" for on-site discharges of the treated water. The
Clean Water Act allows aunicipalities to detemine pretreataent
standards for discharges to Publicly Owned Treatment Works
(POTWs), within its jurisdiction.
Air Stripping «• Air galasJen Standards
Any new source that emits toxic chemicals to the atmosphere at
levels determined by the San Francisco Bay Area Air Quality
Management District (BAAQMO) "to be appropriate for review" oust.
have authorization to construct and operate. Although on-sita
treatment facilities are exeapted by CERCLA froa the
administrative requireaents of the permit, emission liaits and
monitoring requireaents imposed by the BAAQMO permit must be met.
Carbon Adsorption
Use of granular activated carbon (GAC) for reaediation of VOCs
can trigger requireaents associated with regeneration or disposal
of the spent carbon. If the spent carbon is a listed waste or a
characteristic waste then it is regulated as a hazardous waste
under RCRA and California's hazardous waste control laws.
Disposal of contaainants can trigger RCRA land disposal
restrictions. For disposal, the spent carbon would need to be
treated to aeet Best Deaonstrated Available Technology (BOAT)
treatment standards, and RCRA off-site Subtitle C disposal
restrictions would also apply.
Regeneration of activated carbon, using a high-temperature
thermal process, is considered "recycling" under both Federal and
California hazardous waste regulations. Transportation, storage,
and generation of hazardous waste for recycling aust comply with
requireaents in RCRA and California hazardous waste control
regulations. Performance standards for hazardous waste
incinerators can also be requirements for on-site carbon
reactivation. On-site storage of contaminated carbon may trigger
substantive requireaents under municipal or county hazardous
materials ordinances. If the spent carbon is a hazardous waste,
construction and monitoring requirements for storage facilities
may also apply.
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Excavation. Above—Ground Trea^pnent and Disposal of Soil
Excavated contaminated soils will require on-site treatment or
disposal off-site. On-site treatment by above-ground soil
aeration, will need to comply with the substantive provisions of
the BAAQMD and possibly RCRA land disposal restrictions.
Excavated soil classified as a hazardous waste can also trigger
RCRA, state and local requirements. EPA land disposal
restrictions may be applicable for off-site disposal. RCRA
Subtitle C may apply to disposal of soils on-site.
For the on-site treatment of soils, the BAAQMD regulates aeration
of soil containing over 50 ppb of organics. The BAAQMD sets rates
at which soil can be aerated depending upon the level of
chemicals. BAAQMD Regulation 8, Rule 40 on the treatment of soil,
assuming it is a hazardous waste, may also trigger RCRA land
disposal restrictions and BOAT treatment requirements.
LOCATION SPECIFIC ARARs
Fault Zone
The MEW sites are not located within 61 meters (200 feet) of a
fault. Therefore, the fault zone requirement of 40 CFR Part 264
is satisfied.
Floodplain
A hazardous waste treatment facility located in a 100-year
floodplain must be designed, constructed, operated, and
maintained to prevent washout of any hazardous waste by a 100-
year flood. The MEW site is not located in a floodplain,
therefore these requirements are neither applicable or relevant
and appropriate.
11.0 OTHER CRITERIA CONSIDERED
In establishing selected remedial alternatives, EPA considers
various procedures, criteria and resolutions. These "to be
considered" criteria (TBCs) do not raise to the level of ARARs,
but are relevant to the cleanup of the site. The following
discussion presents selected criteria relevant to the selection
of remedial alternatives.
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Criteria Establishing Local Groundwater as a Source of DrlniHn«
Various criteria were used to establish that th« shallow, c, and
0«sp aquifers are a source of drinking vatsr. EPA's groundwater
classification systaa was used. Using the "EPA Guidelines for
Ground-Water Classification" as a guide, EPA determined that the
A- and B-aquifers in the NEW area are classified as "potential
drinking water sources*. Currently, the C-aquifer and Deep
aquifers are used for drinking water and therefore would be
classified as a current drinking water source. As stated in the
ARARs section, the Regional Water Quality Control Board
classified the shallow groundwater as "potentially suitable for
municipal or domestic water supply". The RWQCB determined that
this classification is consistent with the State Water Resource
Control Board's Resolution No. 88-63, which describes criteria
for designating sources of drinking water.
State Criteria for Groundwater Cleanup
California has criteria for evaluating drinking water quality and
groundwater cleanup: advisory Drinking Water Action Levels, and
advisory Applied Action Levels.
Drinking Water Action Levels are health-based concentration
limits set by DHS to limit public exposure to substances not yet
regulated by promulgated standards. They are advisory standards
that would apply at the tap for public water supplies, and do not
rise to the level of ARARs. Nonetheless, they have been
considered in developing cleanup standards for the MEW site.
Applied Action Levels (AALs) were developed by DHS for use with
the California Site Mitigation Decision Tree. AALs are guidelines
that DHS uses to evaluate the risk a site poses to certain
biologic receptors. They are neither enforceable, nor ARARs, but
have been considered in developing cleanup standards for the MEW
site.
Groundwater criteria, to be considered for determining cleanup
levels, are presented in Table 11-1.
California Resolution 68-16
Resolution 68-16 is California's "Statement of Policy With
Respect to Maintaining High Quality of Waters in California". EPA
regards Resolution 68-16 as criteria to establish groundwater
cleanup levels. The policy requires maintenance of existing water
quality unless it is demonstrated that a change will benefit the
people of the state, will not unreasonably affect beneficial uses
of the water, and will not result in water quality less than
prescribed by other state policies.
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TABLE 11-1
GROUNDWATER CRITERIA TO BE CONSIDERED
MIDOLEFIELD/ELLIS/WHISMAN STUDY AREA
Cheaical
State
Drinking Wat«r
Action Levels
(•g/liter)
State
Applied
Action Levels*
(•gyiitar)
Oroanies
Chloroform
1,2-Dichlorobenzene
1,1-Diehloroethane
1,l-Dichloro«th«n«
1,2-Dichloro«th«n«
Freon-113
Phenol
Tetrachloro«then«
1,1,l-Trichloro«than«
Trichloro«th«na
Vinyl Chloride
Inorganics
Antimony
Cadmiua
Arsenic
Lead
0.020
0.130
0.020
0.016
18.000
0.004
0.006
a/ Applied Action Level for water for huaan receptors.
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A beneficial use of the groundvater in the shallow and deep
aquifer systea is drinking water. Establishing a cleanup level
which maintains this beneficial use should attain the
requirements of Resolution 68-16.
Remediation Levels for Soils
A standard for the remediation of contaminated soils was reached
during the Feasibility study by using a simple percolation-
transport model with the concepts presented in California's Site
Mitigation Decision Tree. The model was used to determine
concentrations in soil based upon transport downward into
groundwater. Based upon the analysis from the model, a soil
remediation goal of 100 times the groundwater remediation level
is appropriate to set cleanup standards in soil.
Health Advisories
EPA considers that for a remedial action of a drinking water
source to be protective, it'should have a cumulative risk that
falls within a range of 10"* to 10 individual lifetime excess
cancer risk. To evaluate the risk to public health posed by
recommended cleanup goals, health advisories were used to
establish cumulative risk. Lifetime average daily doses (LAOO)
were calculated by multiplying a concentration by 2 liters per
day and dividing by 70 kilograms. Cancer risk for a constituent
of a given concentration was determined by multiplying the LADD
by its Cancer Potency Factor (CPF). Ratios of contaminants in
aquifers of the site were then calculated in relation to TCE. A
summation of risk for carcinogens in each aquifer were calculated
for a given concentration of TCE. For a 5 ppb (MCL) .cleanup goal
for TCE in the A-, B1-, and B2- aquifers the cumulative estimated
carcinogenic risk falls within a range of 1.3(10)"5 to 7.4(10) .
In the C- and Deep aquifers the cleanup goal of 0.8 ppb
corresponds to a cumulative estimated carcinogenic risk of
1.0(10)"4. Supporting calculations are presented in the
Feasibility Study.
Cleanup goals in the shallow aquifers, above the B/C aquitard,
are set at 5 ppb for TCE. Cleanup goals in the C and Deep
aquifers, below the B/C aquitard, are set at 0.8 ppb for TCE.
Assuming the ratios of carcinogen remain relatively constant,
attainment of these goals will result in achieving EPA's
acceptable risk range of 10*4 to 10 upon completion of the
remedial action.
Air Stripping Control Policies
Any existing and new source(s) that emit toxic chemicals will
have to comply with any EPA, BAAQMD, or Air Resources Board
policies on control of air emissions from air-strippers.
20
-------
12.0 SUMMARY OF ALTERNATIVES ANALYST^
This section presents an analyses of the alternatives, evaluated
in the detailed analysis of reaedial alternatives, with respect
EPA's evaluation criteria. Design eleaents of the alternatives
are presented in Section 9.0. Table 12-1 provides a summary of
the advantages and disadvantages of each alternative's
performance and cost.
State and community acceptance are discussed below:
State Acceptance
The State (of California) generally , supports EPA's proposed
cleanup plan. The state consented, however, that the cleanup
goals for soils and groundwater inside the boundary of the
existing slurry walls should be 0.5 ppa TCZ for soil and 5 ppb
TCE for the groundwater; the saae goals as for outside of the
slurry walls.
In the Responsiveness Sunaary, EPA stated that the slurry walls
in conjunction with pumping and monitoring will be protective of
the public health and the environment, with the 1 ppa TCE cleanup
goal for soils bounded by the slurry walls. This monitoring and
pumping strategy will liait the amount of contaaination that can
leach into the shallow aquifers, outside of the slurry walls. EPA
did respond to the State's request of a 5 ppb TCE cleanup goal
for all shallow aquifers, by establishing the 5 ppb TCE cleanup
goal for the aquifers inside of the slurry walls.
Acceptance
The coaaunity agrees with EPA's proposed reaedial alternatives,
although there is concern with the length of time estiaated to
achieve the shallow aquifar cleanup goals. The use of the "hazard
index" was urged to establish cleanup goals instead of MCLs. EPA
explained in the Responsiveness Summary that the hazard index was
not applicable to the MEW area.
In addition, reuse of the extracted groundwater was recoaaended
by the coaaunity. As stated in the Responsiveness Summary, reuse
of extracted groundwater will be evaluated and is a component of
the ROD.
The Responsiveness Summary (attached) addresses these concerns
and others in aore detail.
21
-------
Table 12-1
Criteria for the Evaluation ol Remedial Alternatlvi
(conlInued)
AIJIRNAiltt
lONt 21
NO fURlHfR AC 11 ON
IN SHU SOIL AHU1ION
WIIH CARtON
AOSORPIION MO
REfifNIRAIION)
MAINUM
UftMtO KIORAUIIC
CRADIINIS IUIIH
tRfAIMNf Of
IIIRACICO UAIfR)
HUSHING (UHH
IRf AIMNI Of
IIIRACltO NAUR)
SHORMtm
HftCJlttNISj
NO IfffCl IN
SHORMCRM
CffCCtlVC IN
SHDRMCRM
CffCCIIVC IM
SHDRI-HRN
NOI CffCCllVC
IN SHORMfM
IONG HUH
iffCCIIVfNISS
AND MttUNIMCC
AllOVS CONI'O
NICRA1ION
HRMANfNI
SOIUIION
KRNANCNI
SOIUIION OUI
RCQUIRCS
COMIINUCO
riMflNG
rCRMANINI
SOIUIION If
NO CNfNICAl
HIGRAIION
RfOUCIS IOIICI1V.
HDBIilll. fOJUMC
NO ACIIVI RIOUC
1ION IN IOIICII*.
HORItllf OR VOIUNC
RIOUCIS 101 1C HI.
HOIIlllf AND
VOIUHC
REOUCIS tOIICIIf,
NORIlltf AND
VOIUNC
RIOUCIS IQllCllf,
NDBIllIf AND
VOIUHC If NO
CHIHICAI NICRAIION
INPLININIARiiilf
NO ICCHNICAl
IINHAIIONS
NO IICNNICAl
IINHAIIONS
NO IfCMNICAl
tlNHAIIONS
NOI fCASIHC OUC
10 comii site
SIRAIIGRAraf
CONPIIANCC
HUH ARARi
DOCS NOI
HECI All
ARARs
comics
WITH ARARl
comics
HUH ARARi
comics
NUN ARARl
lONC-ICRN
fHOICCIION Of
HUNAN HIAIIH AND
rmicciioN
novioco if
UMIIORIIK omi
noviocs
htOUCllON
rROVIHS
NOUCIION;
NCCOS
INSIIIUIIONAl
CONIUOt
PtOIICIlON
IINIICO If
CHCNICAl
MlfiRAIIW
Aoori
CAMIAl
COSIS
JOM'SI
II
I.Bil
to
t.MI
I
1.011
ANNUM
OIN
COSIS
10831
IM
l.tft
io
Mf!
S9S
I.4S9
WSINI
NORIH
(ro«Mlt4.
OM'sl
I.MO
4.100
to
9.900
1.000
11,000
-------
•n
t"
Tabla 12-1
Criteria for lha Evaluation of RamadlaJ Aliarnallvat
HIIRNAIIVC
IONC tA
n IURIHCR MI ION
SHORMCM
tfff.CIIVf.HCSS
MO Iff1C! II
SHOftl HIM
tone- urn
irrfcuvfNfss
AND MMUHIMCt
MIOW
CONIINUCO
HIGRA1ION
MODUS loncnv.
MOBIUH. VOLUMC
NO ACIIVf IfOUCIION
IN 10IIU1V.
NOtlllll M VOLUME,
IMKIMIMIARlim
NO 1ICHNICAL
UNIIA1IONS
COMF1lANCf
NIlHAIMl
001$ NOI
MilI All
AMIS
lONG-HM
PROIKIION Of
HUMAN MlALIM AND
IHt fMHNOMMfNI
PftOUCIION
HMVIDCO If
NONIIMIN6 ONll
ANNUAl rtCSINI
CATIIAl • I N WMIH
COSIS COSIS Irwmdc
IBOO'Si IQM'H OQQ'tl
N/A
9N-SIIU SOIL AflAIION
UBtN CAUON
U3SMP1ION AND
llfifltflUtlON)
ffffCtlVI IN
SHORI-IINN
ffKNAWNI
SOIUIION
MOUCfS IOIICIIV.
MOIILIIV ANO
VOlUMC
NO IfCHNICAl
IINIIAlIONS
coxnifs
NIIH AftAlt
MOVIMS
MWHCKON
101 IM
MINIAIN INUARO ANO
JPUAftO HIWUUHIC
•RAOICN1S (HUM
IRCAINCNI Of
(IIRACHO NAUR)
tfflClItt IN
SHORMIM
HNNANINI
SOIUIION Ml
MOUIMS
CONIINUCO
NMTING
•[OUCiS lOIICIIt.
HMIllll ANO
VOlUMC
NO HCHNICAL
UNIIA1IONS
CONPLICS
NIIH AMIl
NOVIKS
milCIIONi
NCCOS
INS1IIUIIONAI
CONIMN.S
• 40S 4,100
FLUSHING (NUN
llfATHCMI Of
IIIIACIIO NAUR)
NOI CffCCIIVI
IN SHMMCIM
NNNMIfNI
SOLUIION If
NO CHtMICAl
HIUAIION
MOUCfS SOIICIIt,
MOIILIIV ANO VOLUtf
If NO CHINICAL
MUUIION
NOI fCASIILI OUf
10 CONPLCI SI1C
SIMIICIAMf
CONPLICS
NIIH ARARl
NOICCIION
IINIIf0 IV
CHEMICAL
HIUAIION
Ml I.SOO
MANUAL IICAVAIION
IIIN AMIINI
IfHPCMIUOr AfMIION
NIIH CAUON
lOSMMION ANO
HfUNIMIION)
CffCCIIVf. Ml
INCRf ASCO IIMSURC
DURING IICAVAIION
KMANCNI
UIION
MOUCfS IOIICIIV.
MMIUIV ANO
VOlUMC
OlfflCULI 10
CONIROl AIR
IMNISSIONS
COMPLICS
NIIH ARARt
rmviocs
MOIfCllON
-------
Tabla 12-1
Criteria for lha Evaluation oi Hamadlal Allarnatlvat
(continued)
AllHBUlItt
10NC 4
NO flMtHCI ACIIM
HlOJUItlC R1NIOIAIION
II CftOUMO UAltl
I1IIAC1ION AND
IMAINCNI
SHMMIMI
NO iifici IN
SHOftl-HIN
[fffCHVr. IN
SHOAI-HM
ION6-1IRN
imCMVfNfSS
AUOMS
CONIINUfO
NIGRAIION
fCMANINI
SOiUIION
itoucis ioi ic m,
NOBItlfl. KOlUHf
NO ACIIVf MDUCIION
IN I01ICIIV.
NlWIlllf M KMUHC
NIOUCIS I01ICIII.
HOB U II* AND
•
NO IICHNICAl
I IHI1 AIIOHS
NO IICHNICAl
UNIIAHONS.
•!• in ^^^^ifn
DOCS NOI
MI! Alt
ARAIs
COMF1 US
MIIH ARAMs
ION6-1INN
MOIICIION Of
HUHAN HfAllH MB
IHt IMilMNNINi
KOlfCIION
raovioiB •«
NONIIMlNfi 0*1
fROVIMS
AODI't ANNUM NESCNI
CANIAl 0 I N IMIN
COSIS COSIS (r«Mndt4,
1000*SI "" "
It
131
III t.OOO
«•§
VOIUHC
1.100
io
4.200
(!)
NOI APrtlCAMI
-------
Table 12-1
Criteria lor the Evaluation ol Remedial Alternatives
|CMtlMI«4|
AIltMUIIM
10* )
': NO lUtUHtl ACIION
NlDMIftlC CONINOl II
IIIIACIION
AMD IftlAIMNI
NIOBAUUC MNfOIAIION
II UOUNO NAItl
If IIACIJON MB
IIIAININI
ttlllCM iMNNJCAUf
UUUIIUS
SHOII -KM
ItllCIIIINIli
NO IIIICI M
SHOII KM
IIIICIIM IN
SHMMIIN
IfflCtll! IN
SHMMIAN
IIIICIIIE. Mil
roiiniM lot
iirosutf DMIINJ
ION6-IIM
HriciiviMss
AMD MMANIMff
AllOWS
CONIINUIO
riMANtNl
SOiUIIM INI
icquiics
CONIINUfO
NMPIN8
rCIVMNlNI
SOtUIION
NOI A
eWJffJI
NIION
MOUCIS 1011(111.
HMItilr. IQllttf
NO ACIIII MOUCIION
IN lOllCllff.
NOOUIIf M MNUNI
UOUCIS lOHCIIt.
HOIlillt AND
I01UMI
MDUCIS IOIICIIV,
NOOILIIV AND
fOLUHt
DOES NOT |
MEET CMTCRIA
iMMIMINIAaifUlf
NO IICNNICM
UNIIAIIONS
NO IICNNICM
tlNHAIIONS
NO IICHNICM
UNIIAIIONS
IINIASIIU PUC
10 IICHNICM
IMIMIIONS
COMniANCE
NUN ARAAi
MIS NOI
Mil Ml
AMIl
com iis
NUN ARAIi
com iis
Ml IN ARAii
DNS NOI
NEH Ml
AIMS
IONC urn Mori AHUM
MOIICIION or CACIIM 0 1 N
NUNAN MM IN AND COSIS COSIS
IK IHIIiMtm HfiUl mf^ii
NOIICIION SIO IM
rnotioto ii
MMIIMINB OJtl
MUM f.fii i.in
NOHCIIONS HIM
CONIMIS
NOVIMS I.Sfl f.SOJ
NOUCIIOM ' *
rAIIIAl 1S.4II I
raoiiciioNi Mits
INSIIINIIMM
MISINI
NORIN
MM'il
W9^m ^ •
MM
If.SM
"if
II.MO .
JS.4M
CONSItUCIION
CONINOIS
Note: Section 121(b) ol CERCLA stales a pralerence for treatment which permanenlly and
slgnNfcanlly reduces the volume. loxteHy or moblldy ol (he conlamlnanls. The use ol vertical
Impermeable barriers (I.e., slurry walls) by themselves Is oomalrtment and source control, and
does nol constitute treatment. Only with the addition ol groundwaler extraction and treatment
does this alternative meet statutory criteria. While this evaluation differs somewhat from the
evaluation found In (he fS. II does nol ailed EPA's remedy selection.
-------
Criteria for the Evaluation ol Ramadlal AllarnallvM
AMiRNAIIVI
lout I
NO rURIHtl AC II ON
SHORMIM
imcntmm
Ml IfffCf IH
SHORMIRN
lONC-IERM
trrcciiviNCSs RIOUCIS lonciiv,
AND MRMAMtNM HQRIllll. VQtUMt
MUMS
CONIIMUfO
MICRAHON
NO ACIIVt RfOUC-
IION IN IOI1CIIV.
NOIIUIf M VMUNC
NO IICHNICAI
UNIIAIIONS
CONPUANCt
HUH ARARt
DOCS NOI
NCU All
ARARs
lONG-HRM
moitcuoN or
HUNAN HIAIIH MO
IHEJMMlAQNNiNI
MOIKflON
NOVIMO IV
NONIIMIN6 OMV
MVI't ANNUM.
CANIAl 0 I N
COSIS COS!
IQOQ'SI IQOO'SI OOO'il
MCSINI
WMIH
IN SHU SOU AfMIION
IUIIH CAMON
MSOiFIION AND
•CCCNfMIIONI
imciivc IN
SHMMIIIN
KMIANtNl
SMUIION
UOUCIS IOIICIIV.
NMIlllV AND
VOiUNC
NO UCWICAI
IINIIAIIONS
COW |£$
HUH ARMS
MOVIOfS
MOIICIION
!.!•'
lo
1,1 JJ
llf I.
10 io
Ml 5,000
IICAVAIION
HUH ANIItNl
KNKRAIUiC AtlAIION
(HUH CAJUMM
AOSORfllON AND
R(fiCNIMtlON)
imcuvi. tut
roiiNMAi rot
INCRCASCO
firOSURC OURIH6
IICAVAIION
HRNANCNI Mil
HOI A CONKIIf
SOIUIION
RfOUCIS IOIICIIV,
HOBILIIV AND
VOlUNf
oirncmi 10
CONIIOL All
INISSIONS *J*P Alt
INPACICO SOIll
NOI •INfOlAlli
OOfSNOI
NCU ARARs
fOR UNII-
CAVAUO
SOUS
CHINICAIS Iff!
IN SOUS COWO
HICRAIC 10
SHAltOH
AQUIflRS
i.ioo
fARIIAl fICAVAIION
HUH ANRltNl
IINMRAIURE AIRAIION
AM IN-SIIU SOU
AfRAHON
IHMH CARBON
AOSORfllON AND
RffiCNfAAIION)
irflCIIVI. Ml
INCREASfS
IIPOSURt OURINS
IICAVAIION
MRNANiHI
SOIUIION
RfOUCIS IOIICIIV,
HDBIIIIV AND
VUUNI
01 ff ICWI 10
CONIROl AIR
INISSIONS
COWlltS
HUH ARARi
MOVIOfS
NOIICHM
i.m
to
tio
to
i.m MI R.MO
i.soo
io
-------
13.0 THB SELECTED
The selected remedies for soils are: 1) in-situ vapor extraction
with treatment by vapor phase granular activated carbon ((SAC),
and 2) excavation and treatment by aeration to meet federal,
state, and local air standards. Most of the vapor attraction will
be performed on soils inside of the existing Fairchild and
Raytheon slurry vails, where the highest concentrations of soil
contamination are found. The vapor extraction is estimated to be
in operation froa 1 to 6 years. The excavation and treatment of
contaainated soils aay invoice RCRA Landban requirements which
would also require treatment to aeet BOAT standards. Intel has
previously excavated and aerated their contaainated soil under
RWQCB orders. These selected remedial alternatives will likely be
used at other potential sources in the HEW area. EPA expects soil
remediation to be implemented by the PRPs.
The soil cleanup goals for the MEW area are: 0.5 parts per
million (ppm) TCE for all soils outside of the slurry walls and 1
ppm TCE for soils inside the slurry vails. The cleanup goal for
soils outside of the slurry walls is based upon the amount of
contamination that can remain in the soil, leach into the
groundvater and still achieve the cleanup goal for the shallow
aquifers. The rationale for the use of a higher cleanup goal for
soils bounded by the slurry, walls is presented in the following
discussion* Although the aquifers bounded by the slurry walls are
considered potential drinking water sources, this groundvater is
effectively isolated when local hydraulic control is implemented
by pumping inside the confines of the slurry walls. This
isolation of contaminated groundwatar and soil bounded by the
slurry walls provides an additional level of protection of the
significantly larger drinking water source outside of the slurry
walls. This additional level of protection through the use of a
slurry vail system (slurry wall and hydraulic control) allows for
a higher soil cleanup goal for soils confined by the slurry
walls. But, the use of the 1 ppm TCE cleanup level for these
soils is dependent upon the continued operation of a pumping
systea which maintains local hydraulic control of groundvater
inside the slurry vails. If local hydraulic control by pumping
vas to cease, then the lover soil cleanup goal of 0.5 ppm TCE
vould need to be attained. In summary, the soil cleanup goal is
higher inside of the slurry vails because of the extra degree of
protectiveness provided by the slurry vails in conjunction with
the maintenance of inward and upward gradients into the area
confined by the slurry vails, with a systea of hydraulic control
by pumping of groundvater. To ensure that the slurry vail system
is effectively vorking, regular monitoring vill be performed of
local groundvater quality and water elevations. During the
22
-------
duration of the remedy, there will be an evaluation of the remedy
and cleanup goals at least every five years.
The selected groundvater reaedy is hydraulic reaediation by
groundvater extraction and treataent. The groundvater cleanup
goals by puaping and treataent are: 5 ppb TCE for the shallow
aquifers (including the aquifers inside the slurry vails) and 0.8
ppb TCE for the C and Deep aquifers. The cleanup goal is acre
stringent for the C and Deep aquifers, because they are currently
used as a supply for aunicipal drinking vater and will be
technically easier to reaediate than the shallow aquifers. The
0.8 ppb cleanup goal corresponds to a 10** cumulative (human)
cancer risJc.
Although the shallow aquifers are not currently used for drinking
vater, they are a potential source for drinking vater and
therefore a 5 ppb TCE cleanup goal has been established which
corresponds to between a 10 and 10"5 excess cancer risk, which
is within EPA's acceptable risk range. Cancer risks have been
screened for all aquifers and the cheaical ratio of TCE to other
chemicals found at the site is such that achieving the cleanup
goal for TCE will result in cleanup of the other site chemicals
to at least their respective NCLs.
The estimated time to reach the deep aquifer cleanup goal is
between 2 to 45 years. The tiae to reach the shallow aquifer
cleanup goal may be considerably longer, possibly froa 46 years
or into the indefinite future, because of the physical and
cheaical nature of the shallow aquifers. They are low yielding
and contain soils with a high clay content which attract and
retain the site chemicals. During the duration of the remedial
effort, both shallow and deep aquifers will be regularly
monitored for water quality and groundvater elevations.
The extracted groundwatar will be treated largely by air
strippers, although some companies (e.g., Intel) may use their
existing liquid phase GAC units. The three currently operating
air strippers have been permitted by the Bay Area Air Quality
Management District and are not using emissions controls. The air
stripper stacks have been designed to meet risk levels of <10
excess cancers. He anticipate that with the additional air
strippers to be installed and the increased flow rates during
full scale reaediation, emissions controls will likely be needed
to aeet more stringent air district standards. The emissions
controls vill consist of GAC vapor phase carbon units.
The extracted groundvater vill be reused to the maximum extent
feasible, with 100% reuse as a goal. The remaining extracted
groundvater vill be discharged under NPDES requirements to
Stevens Creek. Work has already commenced on various vater reuse
options, which vill be presented and implemented during the RD/RA
phase.
23
-------
The remedy also includes the identification and sealing of any
conduits or potential conduits, using the decision process
outlined in the FS. Several identified abandoned agriculture
wells have allowed contamination to migrate from the shallow
aquifers to the deep aquifers. These wells have subsequently been
sealed. Additional wells have been identified for sealing and
other wells may also be identified during RD/RA phase which will
require sealing.
To evaluate the effectiveness of remedial actions and to
determine when cleanup goals are attained, regular monitoring of
chemical concentrations and water elevations is required at
selected wells across the site. For soil cleanup, EPA will need
to concur on a method to determine when the required cleanup
goals have been achieved.
The estimated costs of the selected remedies are provided in
Table 12-1 and include the use of emissions controls, well
sealing, and monitoring. The total cost of the remedies, in
present worth dollars, is estimated to be between $49M to $5€M.
14.0 STATUTORY DETERMINATIONS
The selected remedies are protective of human health and the
environment — as required by Section 121 of CERCLA — in that
contamination in groundwater is treated to at least MCLs and
falls within EPA's acceptable risk range of 10*4 to 10*7. In
addition, the remedy at least attains the requirements of all
ARARs, including Federal and State MCLs.
Furthermore, as shown on Table 12-1, the groundwater remedy -
pumping, and treating with air strippers and the soil remedy -
vapor extraction, are oost effective technologies. Soil
excavation with aeration has also been shown to be cost effective
when it was used at the Intel facility, and may also be used at
other facilities.
The selected remedies will permanently and significantly reduce
the toxicity, mobility, and volume of hazardous substances with
respect to their presence in soils and groundwater. The use of
vapor extraction for soils is an innovative treatment technology
for removing VOCs.
Contamination is controlled and removed from the groundwater,
thereby reducing the potential threat to the nearby public water
supply wells and also restoring the aquifers to meet drinking
water standards. The slurry walls in conjunction with pumping and
treatment reduces toxicity, volume and mobility of contamination
to migrate from major source areas. The sealing of conduit wells
24
-------
will reduce the likelihood of vertical migration of
contamination.
Emissions from soil vapor extraction will be controlled by vapor
phase GAC. Emissions from air stripping towers will meet local
air district requirements, which are anticipated to be a 10"6
risk level, and therefore will likely require vapor phase GAC.
The regeneration of spent carbon from the GAC emission controls
will meet all Federal, State, and local requirements.
25
-------
-------
SUXXARY
-------
RESPONSIVENESS SUMMARY FOR THE FAIRCHILD. INTEL. AMD RAYTHEON SITES
MIDDLEFIELD-ELLIS-WHISMAN (M-E-tf) STUDY AREA
Mountain View, California
I. COMMUMITY RELATIONS HISTORY
EPA haa carried on an active coaaunity relations prograa at tha Middlafield-
Ellis-Whisaan (MEV) Study Area.
In early 1986, EPA, in conjunction with Santa Clara County, initiated monthly
aaetings for all agencies involved in hazardous waata investigation and cleanup
to review and coordinate activities. Representativea of local, state and federal
agencies, elected officials, business and induatry and public interest groups
attend the aeetings. Tha aeetings continue on-a quarterly basis.
In tha spring of 1986, new eontaaination was found in Mountain View's deep
aquifer This discovery aarkad tha first time eontaaination had been detected at
those depths in that part of Santa Clara County. In response to coaaunity
concerns and questions about the safety of tha drinking water supply, EPA
prepared a fact sheet describing the situation and distributed it to the site
Bailing list.
In May 1986, EPA worked with Fairchild Semiconductor Corp. to prepared a 4-
page insert for Mountain View's The Vlaw to explain Fairehild's proposal to
construct three slurry walls in order to confine their site's contaminated soils
and to pump and treat water confined by the walls.
In February 1987, Raytheon and EPA worked together to prepare another insert
for The View that described Raytheon's proposed slurry wall to contain
eontaaination around their site.
Zn June 1987, EPA worked with Raytheon, Intel and Fairchild to produce an
insert for The View describing the draft Reaedial Investigation (RI) report.
In November 1988, EPA released a Feasibility Study (FS) on the Middlefield-
Ellis-Vhisaan Study Are to the public. The report described and evaluated
various clean-up alternatives based on data and support documents available at
the time. EPA's preferred alternatives were: vapor extraction and treatment for
soils, pumping and treating for shallow and deep aquifers; and vapor extraction,
groundwater control and treatment for the slurry wall systeas.
In fulfillment of coaaunity participation requirements, EPA held a public
comment period from Noveaber 21. 1988, through January 23, 1989; briefings of
local officials and coaaunity members; and a community meeting. EPA also
prepared a Propoaad Plan face sheet which outlined tha range of cleanup
alternatives, cleanup goals, and EPA's preferred alternative for distribution to
tha site mailing list. Prior to tha fact sheet. EPA also released a press
advisory announcing the range of alternatives and EPA's preferred alternative.
-------
The community meeting was held December 14, 1988, to present clean-up
alternatives, to answer questions and to take comments on the FS. Comments
centered on the length of the cleanup period and on who would do the cleanup.
Written comments on EPA's Proposed Plan focussed on the following issues:
cleanup levels for soil and groundwater, length of public comment period,
variations in the text of the FS report, and length of cleanup time. Responses
to public contents are addressed in the attached response summary. Most of the
comments were submitted by Potentially Responsible Parties.
II. SUMMARY OF PUBLIC COMMENTS AND AGENCY RESPONSES
1 Comments
1. CffBaftnt: Several comments concerned the number and location of recovery
wells to be placed in the MEW area.
EPA Response: The Feasibility Study (FS) and Proposed Plan are not design
documents. The exact number and location of recovery wells will be determined
during the remedial design phase.
2. Comment: NASA-Ames Research Center.had several concerns: 1. how the
proposed treatment system would handle groundwater contaminated with fuel, 2.
how other cleanup actions may be influenced by the proposed recovery wells, 3. .
the effects that the proposed hydraulic remediation may have on existing
contamination at NASA-Ames and the adjacent Moffett Naval Air Station.
EPA Response: The above concerns will be addressed during the Remedial design and
Remedial Action (RD/RA) phases. Obviously, a large degree of cooperation and
coordination will be required by the affected parties during RD/RA, to ensure a.
successful remediation program.
3. Comment: "The FS proposes to remediate soils using in situ soil aeration.
Air inlet wells may also be installed to increase the efficiency of the soil
aeration system. It is suggested that if air inlet wells are to be installed chey
should be used to control the extent of an in situ negative soil air pressure
field, not to increase soil air flow through the contaminated soils. If they are
installed solely for the purpose of increasing airflow across the contaminated
soil particles, their use is questionable."
EPA Response: VOC's have a marked tendency to partition into the soil
atmosphere. The rate of desorption into pore space is principally a function of
chemical diffusion in response to a concentration gradient. Sweeping of clean air
through a soil matrix increases the concentration gradient and therefore
increases partitioning and the overall efficiency of the in situ soil aeration
system. The result of creating a negative air pressure field, with an in situ air
stripping system, does have a minor effect on soil-air partitioning, but the
field tends to be localized around the extraction well(s) and the overall effect
is negligible. The key to an efficient in situ vapor extraction system is
increasing the airflow across contaminated soil particles and not simply to
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eoncrol the negative soil air pressure field. The use of air inlec wells will be
analyzed further during the RD/RA phases of this project.
1. C«i«iM«g? Several commenters who are Potentially Responsible Partiee (PRPs)
stated that the comment period was too short to adequately review the FS end
Remedial Investigation (RI) report. Requests were made to extend the comment
period.
gPA Response: The National Contingency Plan (NCP) requires that the RI, FS and
Proposed Plan be provided to the public for review and comment for a period of at
least 21 calendar days. The new proposed NCP requires a utttiumi 30 calendar day
public comment period.
EPA has exceeded both of* these requirements by providing a 64 calendar day public
comment period on the RI. FS and Proposed Plan. The comment period was extended
(at the December 14, 1988 public hearing) to January 23, 1989, from the original
January 9, 1989 deadline.
2. Commene: Several PRPs.stated that the RI report and FS were not readily
available for review.
EPA Response: A draft RI report has been available to the general public at EPA
since July 1987 and also in the City of Mountain View public library since
August, 1987. The final RI report has been available at these respective
locations since July, 1988. Furthermore, EPA in its general notice letters
issued in August and September, 1988, notified the commenters and others of che
availability of an administrative record that contained supporting documentation
for the MEW study area. The FS was made available to the public in the EPA and
Mountain View libraries at the beginning of the comment period November 21, 1988.
In addition, copies of the FS were also available for purchase from Canonle
Engineers, the preparers of the FS.
3. Comment;: Several PRPs claimed that there were "inconsistences" .between FS
reports on reserve at the Mountain View Public Library, the FS report at the EPA
library, and copies provided by Canonie Engineers.
EPA Response; EPA acknowledges these concerns, however, we believe any
differences to be minor in nature and would not affect the scope of the FS
report. Copies of the FS report were reedily available for review at the EPA
library during the entire public comment period.
4. ^flTifflTlSr One comaenter wrote that EPA announcements regarding the review and
comment period and public meetings needed to be more widely distributed.
EPA Response; Announcements regarding the MEW public comment period and the
public meeting were published in "The View", "The Los Altos Town Crier", "The
Times Tribune", and the "San Jose Mercury News" (Peninsula Extra Edition). In
addition. EPA's Proposed Plan, which also announced the public comment period and
public meeting, was sent to EPA's MEW mailing list that consists of over 100
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IUUMS. We will also be periodically updating our Bailing list and will contact
local officials and community groups for assistance in updating that list.
5. Caiaffflt;. A number of commenters claimed that th«y were not PRPs. Some of
these commentars also citad references to other PRPs or inferred sources, in the
RI report.
EPA Response: The determination of who is or who is not a PR? is not relevant co
the selection of a reoedy. Furthermore, in its August 8, 1988 approval of the RI
report, 'EPA neither agrees nor disagrees with the assumptions or assertions
regarding 'inferred sources or other PRPs' as presented in the RI report." EPA
makes its own determination of liability independent of the RI/FS process.
6. CTBTCflnt ; Several commenters who are PRPs wanted to know hov other PRPs will
be dealt with, hov cleanup costs will be allocated, and who is responsible for
cleanup.
EPA Response: EPA is currently evaluating PRPs to determine who will receive
Special Notice letters for Remedial Design and Remedial Action (RJD/RA) to 17
parties. The responsibility for cleanup lies with whomever EPA determines to be
a PRP. The allocation of cleanup costs are usually decided among the PRPs.
7. Comment: Two PRPs wrote that remediation of the C and deep aquifers should
be addressed as a separate operable unit. The reasons given were that the C and
deep aquifer contamination is limited to localized areas, the contamination was
not caused by the respective commenters, and, operation and maintenance cost will
be increased.
EPA Response:- EPA does not designate operable units to separate cost allocations
among various PRPs. The commenters have offered no compelling technical or
environmental reasons why there should be a separate operable unit for the C and
deep aquifer remediation. EPA believes that including the deep aquifers in Che
comprehensive remedial plan for the entire MEW Study Area is the most efficient
use of agency and PRP resources. Furthermore, 40 CFR Section 300.6 simply
defines an operable unit, "as a discrete part of the entire response action that
decreases a release, threat of release, or pathway of exposure.*
The Following Selected Co"""ents Concerning EPA'a Process Were Submitted bv Stltec
1. Comment: Page 1. Siltec claims that a copy of the final RI was not made
available to them until January 13, 1989. Siltac has not had a reasonable
opportunity to review or comment on all of RI's contents.
EPA Response; A draft RI has been in the Mountain View public library since July
1987. The final RI was delivered in July, 1988, to EPA and the Mountain View
Public Library. Siltec has had ample time to review the RI since EPA stated at
the October 1988 "kickoff meeting attended by Siltec representatives, that the
final RI was available for review in the EPA and Mountain View libraries.
Siltac seems to be arguing that EPA should have had a separate public notice for
the RI, citing U.S. v. Sevmour Recycling Corp. 679 F. Supp. 859 at 864. If thac
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is Siltec '* contention, EPA disagrees. EPA notes that • separata Rl review
process is slaply not conteaplatad by CERCLA nor U.S. v. Sevaour
679 F. Supp 939 (S.O.Ind. 1987). In clue CM*. the eourc notes that, pursuant to
CERCLA as amended by SARA, the generator defendant* are entitled to coaaant on
the selection of a reaedy before the reaedy is selected. In P.S. v. Savaour
Reeve liny Carp., a* here. EPA provided the generator defendants an opportunity to
coaaent on the reaedy before a selection of the reaedy has been Bade.
EPA also notes that Siltec was given notice that it was a potential responsible
party in the MEW area in May, 1985 and was given an opportunity to participate in
the RI/FS process. Thus, Siltec was on notice that the RI/FS was being prepared,
and therefore, Siltee should have been tracking the progress of the RI/FS.
2. CamMtig; Pages 3-4. Siltee has been unable to eoaaent on the FS because of
substantial uncertainty about the accuracy and validity of the FS distributed for
public coaaent. .
EPA Response: EPA disagrees with the statement that "there is substantial
uncertainty about the accuracy and validity of the FS distributed for public
comment." As stated above, the FS was available to the public in the EPA and
Mountain View libraries at the beginning of the coaaent period, November 21,
1988. In addition, copies of Che FS were also available for purchase froa
Canonie Engineers. Any inconsistency between the copies was ainor in nature.
3. Comment; Siltec stated that "(TJhe opportunity for meaningful coaaent is
coaproaised where coaplete copies of relevant agency documents have not been made
available in a timely fashion* citing the case of U.S. v. Rohm and Haas Co. Inc.
669 F. Supp. 672, 683.
EPA Response: The facts of U.S. v. Rohn and Haas Company. Inc. are very
different than here. In particular, the public we* given 5 days to submit
comments in U.S. v. Rohm and Haas Company. Inc. Here the public, including
Sileec, was given 64 days to submit comments.
4. Commentr Siltee recommends that cleanup of the C aquifer (the areas below
the B-C aquitard) should be addressed as a separable operable unit as the term is
defined at 40 CFR Section 300.6 and as permitted by 40 CFR Section 300.68(c).
EPA Response: 40 CFR Section 300.6 simply defines an operable unit as "a
discrete part of the entire response action that decreases a release, threat of
release, or pathway of exposure." EPA fails to see the benefit of addressing the
C aquifer as a separate operable unit solely for cost allocation purposes.
The Following Selected CommenC* Concerning EPA*a Process Were Submitted bv Air
Products
1. Coaaunf- "EPA does not have the power to create or affect liability of
persons at a 'Superfund site' slaply by drawing the 'site boundary' at one
location versus another.*
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EPA Response: The FS does not address the liability of persona ae the MEW site.
EPA notes that liability is determined by CERCLA Section 107, not the drawing of
site boundaries.
2. Comang ? "EPA lacks the authority under Section 104 to order Air Produces to
require testing."
EPA Raaponaa: Orders requiring testing under Section 104 are not addressed in
the RI and FS. EPA notes Air Product's legal opinion.
Comments Concerning the Proposed Cleanup Coals
1. Comment: The Regional Water Quality Control Board (RWQCB) commented that the
cleanup goal for the groundwater inside the slurry walls should be set at 5 parts
per billion (ppb) -• the same goal set for the groundwater outside of the slurry
walls. The Board commented that EPA's groundwater classification applies to all
aquifers including aquifers within slurry walls.
EPA Response: EPA's Proposed Plan recommended a 5 ppb cleanup goal for the
shallow aquifers. Although not specifically stated, this 5 ppb goal would also
apply to the aquifers within the slurry walls.
2. Comment; The RWQCB also commented that the cleanup goal for soils within che
slurry walls should be set at .5 parts per million (ppm) -• the same level for
soils outside the slurry walls. The Board was concerned about relying solely on
slurry walls to prevent migration of contamination 'because the long term
integrity of slurry walls has not been demonstrated."
EPA Response: In addition to pumping within the slurry walls (to assure an
inward gradient), there will be continuous monitoring of water levels and
chemical concentration inside and outside of the slurry walls. Performance
monitoring will be an integral part of any RD/RA Consent Decree. In the event of
a slurry wall failure, additional measures can be taken such as, modification of
the walls and pumping rates, or applying more stringent cleanup levels inside che.
slurry walls.
3. Comment: The Santa Clara Valley Water District (SCVWD) commented that they
would not prevent a well from tapping the shallow aquifers.
EPA Response: Comment acknowledged.
4. CTBBgnt: The SCVWD is concerned that a cleanup goal has not been established
for che aquifers within the slurry walls.
EPA Response; See EPA response to comment no. 1.
5. Comment; The SCVWD commented that specific protocol should be developed for
reviewing and evaluating the performance of the selected remedy.
EPA Response; The RD/RA process will incorporate specific criteria for
evaluating the cleanup goals and the effectiveness of the remedy. The cleanup
goals and remedy will be evaluated at least once every 5 years.
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6. SSttUSSLL Th« SCVUD recommended that • cleanup goal of 0.8 ppb also be
established for the shallow aquifers.
gPA R«at»ana«; A 5 ppb cleanup goal is protective of huaan health, especially
since these aquifers are not currently used for drinking water. The 5 ppb level
also falls within EPA's acceptable risk range of 10"* to 10"7.
In addition, the cleanup goal may not even be technically feasible because the
aquifers are relatively "tight" (low water bearing zones) and have a high clay
content, thereby making cheaical reaoval difficult and costly.
7. Comment: The League of Women Voters urged EPA to use a "hazard index* to
establish cleanup goals instead of the Maximum Contaminant Level (MCL) for TCE.
The League is concerned about the "mixtures of chemicals" and their effects and
cited the IBM and Fairchild sites in San Jose where the hazard index was used.
EPA Response: EPA believes that a 5 ppb TCE cleanup goal for the shallow
aquifers is protective of human health. See EPA response to the SCVWD.
The ratio of TCE to other chemicals (found at the site) is high enough that a 5
ppb cleanup of TCE will result in a cleanup of the other chemicals below their
corresponding MCLs. The 5 ppb cleanup goal takes into account the additive
effects of the chemicals found at the site, and the resulting risk falls within
EPA's acceptable range of 10"* to 10*7.
The IBM and Fairchild San Jose sites have TCA as the dominant chemical. Drinking
water wells have also been affected at the IBM and Fairchild sites in San Jose,
while no drinking water wells have been impacted at MEW.
8. Comment1 One commenter wrote that Alternative Concentrations Limits (ACLs)
would be appropriate "if no health risk occurs through exposure by contact or
through ingestion of the contaminated groundwater." The comaenter questioned
whether such exposures can be prevented.
EPA Response: EPA is not proposing the use of ACLs at this time. The
applicability of ACLs will be determined during subsequent review periods, once
Che remedy has been implemented and periodically evaluated.
The Following SelecCed Co""«ar>gs Concerning Cleanup Coals Were Submitted Bv
Crosby. Heaflv. Roach and Mav. a Law Flna Representing Sobrato Development
1. C?mtnt: Th* 5 ppb cleanup level for the shallow aquifers "is not necessary
to protect huaan health and safety", and the cleanup level "is unreasonably
burdensome and cose inefficient. The firm also wrote that the shallow aquifers
•are not reasonably anticipated to become suppliers of drinking water in the near
or distant future", and that the enforcement of existing institutional controls
can be used to protect human health. Therefore, less stringent standards should
be applied to the shallow aquifers namely 500 ppb.
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gPA Response: It should first be noted that EPA has proposed cleanup goals
rather than cleanup 1 avals. These goals end eh* noodles will be evaluated
periodically to determine if they ere technically practical, and therefore they
•ay be subject to modification.
EPA baaed its proposed cleanup goals on several factors: 1. The shallow aquifers
are potential drinking water sources even though they are not currently being
used for drinking. This determination is also consistent with the Regional Water
Quality Control Board's Basin Plan and Non-Degradation Policy which are designed
to protect natural resources; 2. The 5 ppb goal Beets EPA's acceptable risk
range of 10"* to 10"7:. The 300 ppb cleanup level which the commenter is
proposing would exceed this acceptable risk; 3. It is unlikely that all of the
abandoned agriculture wells which are currently acting aa conduits or are
potential conduits threatening the deep (current drinking water) aquifers will
ever be located and properly sealed. Experience has shown that abandoned wells
(e.g., Rezendes Veils) can cause significant contamination to migrate from the
shallow aquifers to the deep aquifers. Therefore, absent sealing all of the
abandoned wells, it becomes necessary to reduce the contamination in the shallow
aquifers. The 5 ppb level would then be the Maximum level that could potentially
migrate to the deep aquifers.
2. Comment: "The worst case scenario soil remediation application is
inappropriate." The commenter objected to uniform application of the worst-case
scenario to the entire MEW area. The commenter also stated that future use
assumptions of the MEW site are inconsistent with the City of Mountain View
General Plan and with California Health and Safety Code institutional controls.
EPA Response; Because multiple sources have impacted a common groundwater area
with commingled contaminant plumes (which threaten a current drinking water
supply), EPA believes that a uniform application of a reasonable "worse-case"
scenario and a uniform application of cleanup goals is the most efficient aechod
to assure the protection of public health. This is also consistent with the
approach taken at other sites in Santa Clara Valley and the country. Although
the City of Mountain View's General plan may currently call for
industrial/commercial use of the site, General Plans and land use are subject to
change. The site is also presently bordered by residences west of Whisman and on
Moffett Naval Air Station, and a change in the electronics industry may make
residential use of the site plausible in the future. Other than deed
notifications, it is not clear to which institutional controls of the California
Health and Safety Code the commenter is referring.
Response To Selected CoBments From Sobrato
1. Coitm»^' "The MEW FS purports to apply a percolation rate of 2 inches/year
in calculating the allowable contamination concentrations in the soil. Such a
percolation rate is considered extremely unlikely in properties, like SOBRATO' a,
which have been covered and contained by asphalt. In addition, surface runoff at
the site is comprehensively routed to storm sewers and drains. Therefore,
percolation rates on the SOBRATO properties should be expected to approach nearly
zero."
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EPA Response; Although field studies have not been conducted at the MEW site Co
determine the amount of water infiltrating through the topeoil, the literature
describes exponentially decreasing infiltration rates following a rainstorm.
However, acre water nay infiltrate to the aquifers in periods of long storms,
especially following extended dry periods.
The scenario of calculating soil remediation levels, by assuming potential
residential use rather than current industrial usage, is EPA policy. This policy
has been consistently applied throughout other regions under similar
circumstances. The rationale supporting this policy is that surface coverings and
land use may change and, over the long term,, institutional controls may be
unreliable. The 2 inch/year percolation rate is applied consistently throughout
the HEW area.
2. Cqmnant; "We (Sobrato) would like to point out that if the rationale used as
the basis for the California Assessment Manual (Ca. Admin. Code Title 22,
Division 4. Chapter 30, Article 11) criteria is applied to the subject
properties, the soil cleanup level would be, at a minimum, 5.0 mg/kg.*
EPA Responser The criteria presented in the cited California Administrative Code
defines a regulated hazardous waste and is not appropriate for determining a soil
cleanup level.
The Following Selected C*?Bffl?nC5 Were Submitted bv Heller. Ehnnan. White &
MeAuliffe. Attorneys for NEC Electronics. Inc.
1. Cflnn*nfi' The intended application of the "No Further Action" (monitoring
only) alternative is unclear, since it is discussed primarily for Zone 1 soils
located inside slurry walls.
EPA Response: EPA does not understand the comment, as we believe the application
of the "No Further Action* alternative is adequately explained for each of the
remedial alternatives in Chapter 8 of the FS.
2. Comment: No estimates of the remediation periods for "Partial Excavation
with Ambient Temperature Aeration" (Alternative 3) and "Partial EXcavation and
Ambient Temperature Aeration with In Situ Soil Aeration" (Alternative 4) are
provided.
EPA Response: The time frame for this alternative would be governed by the
factors identified in Appendices G and H of the FS, which state that the
remediation of excavated soils requires 48 hours of disking soils in six inch
lifts. The number of lifts required would depend upon the volume of soil to be
remediated. Table 0-22 of Appendix 0 provides the volume of soils to be
excavated and remediated.
3. Conmenc: NEC Electronics requested the "latitude" to explore other "options"
including those remedial methods outlined in the FS, and other methods in order
to achieve the ROD cleanup goals for vadose zone soils.
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EPA Response: EPA anticipates that the MEW FS will be applied as appropriate co
other sites in tha MEW area. Tha reaedy, in-sieu vapor extraction, was selected
based on a thorough •valuation of the alternatives. In addition, soil excavation
and treataent by aeration was also selected, based on prior iapleaantation in
MEW. If new information or alternatives are brought to the attention of the
agency in the future, the EPA nay consider thea.
4. Comment: le is highly unlikely that contamination in the Rezendes Veils
could have cone from NEC's 501 Ellis Street facilities.
EPA Response: The specific origin* of the Rezendes Wells' contaaination is not
an issue in the selection of a raaedy, nor is liability for the deep aquifers,
sine* Superfund liability is strict, joint, and several.
5. foment • When shallow groundwater is nixed with deep aquifer groundwater in
the saae treataent systsa, thar* will be a "deleterious effect on the water so
treated." This aixad groundwatar will have liaited uses "if surface discharge is
rejected as an alternative after treataent."
EPA Response| While this appears to be aainly true for the A and Bl aquifers,
aose of the B2 and B3 aquifers would not require treataent for aajor ions and
colifora bacteria. See Table 1-6 (Volume X) of the Reaedial Investigation
Report. Furthermore, the "deleterious effects* of mixing the deep and shallow
ground waters in a treatment systea will ultimately be determined by the end use
of the water.
6. Comment: The effects of long term pumping of the shallow aquifers should be
carefully evaluated in light of recent experience with, a similar systea at other
sites in th« region. It is not clear if recharge rates and aquifer yields have
been evaluated.
EPA Response: While it is not clear to which other sites in the region the
coaaenter is referring, aquifer yields and recharge rates will be thoroughly
evaluated during RD and befora "any full scale remediation beings. In addition,
water levels, subsidence, etc. will be carefully monitored during RA.
7. Comment: There is no indication that scaling and biological growth in the
air stripping columns have been considered in treetaent facility design or in the
operation and maintenance costs (Otif) shown in the FS.
EPA Response: The operation and maintenance cost estimates for the treataent
systems include packing replaceaent and acid feed systea maintenance, which are
intended to solve or prevent scaling and biological growth problem*. (Appendices
J and K).
8. Comment: 'Thar* is no indication that the FS has considered the costs of
complete replaceaent of treataent units in the annual 06M coats or the capital
costs for the facilities."
•
EPA Response; The annual operation and maintenance costs for each treatment
systea includes replaceaent costs (a.g.. $6,000 for blower repair or raplaceaent,
10
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$11,500 for packing replacement, $14.000 to $22,000 for the acid feed system,
$1,000 for electrical control*, and $3,000 to $4,000 for the air stripper tower).
Reaoonaa To Selected Coaaofnfs From Stltee
Comments on Soil Remediation Levels
1. General Comment: The proposed soil remediation level of 0.5 ppa TCE for
•oils throughout the MEW site which lie outside the slurry walls is not
adequately supported by the FS. We (Siltec) believe that a 0.5 ppa TCE soil
remediation level is incorrectly calculated and incorrectly expressed for several
reasons .
2. CffBBftTlt- The FS states that supporting justification and analysis for
selection of a soil remediation level is based on a "worst case" hypothetical
exposure scenario where the MEW site would be converted to an unpaved residential
area characterized by open lawns and unsewered roof drains allowing maximum
infiltration and subsequent percolation (FS, Appendix Q, p. Q-10). tfe (Siltec)
believe the RI/FS errs in using the worst case analysis to identify the soil
remediation level. An appropriate analysis should consider other more probable
scenarios as the basis for selection of soil remedy for the MEW Study Area.
EPA Response co Comments 1 and 2: The scenario of calculating soil remediation
levels by assuming potential residential exposure is EPA policy. This policy
has been consistently applied throughout other regions under similar
circumstances. The rationale supporting this policy is that land use can change
and, over the long term, institutional controls (e.g., zoning and local planning)
may not be reliable.
•
In addition, the modeling scenario in Appendix Q is certainlynot an extreme
worst case. The following items are examples:
The model allows for instantaneous dilution with the groundwater aquifers
below the contaminated soil zone. In the real world, instantaneous mixing
would not occur leading to higher concentrations in the upper portion of
the aquifer than predicted by the model. The instantaneous mixing given by
the model allows for a dilution of 89 times (0.0112). At many sites
throughout the country, where similar evaluations are performed, no
groundwater dilution would be allowed. The given model assumes the
receptor to be at the boundary of the contaminated zone. In many
instances, a theoretical receptor's well would be modeled directly below
the site. If all of the examples given above were incorporated into the
model, much higher receptor concentrations would be predicted. The result
would be much lower soil clean up levels.
Because of the facts given above, the model is considered a reasonable worst case
scenario, not an extreme worst case. This is consistent with EPA guidance.
3. Comment : Further time sensitive analysis such as the analysis provided in
Table Q-9 is useful to evaluate the degree of potential harm as measured by
various conservative assumptions. Table Q-9, for example, shows that health based
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levels of TCE in Ch« aquifer would be approached for only one year in a thirty-
year period and that otherwise the level of TCE in groundwatar would be below
those levels.
EPA B««p.gnj^; Table Q-9 represents one ease (conservative in concentration and
percolation, not conservative in Kd) from the potential cases given on Table Q-3.
Other cases could be performed. Given different scenarios, (e.g., longer areas,
higher soil concentrations and lower dilution), long tern elevated groundwater
concentrations could easily be greater than 5 ug/L.
4. Cement: The worst-case analysis used to support a soil remediation level of
0.5 ppa TCE in soil assuaes a percolation rate of 2 inches/year. However, the
EPA approved model used to arrive at percolation rates is stated to result in
•virtually no percolation to the saturated zone." The FS use of a 2 inch
percolation rate is based on a theoretical possibility of the effect of prolonged
Pacific frontal systems. No justification for or analysis of the effect of the
frontal system is given by the FS. If a worst case analysis is used at all, the
soil remediation level analysis should be calculated using a lower percolation
rate.
EPA Reaconaa: Although field studies have not been conducted at the MEW site to
determine che amount of water infiltrating through the topsoil, the literature
describes exponentially decreasing infiltration rates following a rainstorm.
However, more water may infiltrate to the aquifers in periods of long storms,
especially following extended dry periods.
•
Assumptions used in the EPA model resulted in calculating little or no
infiltration in the MEW area. This model uses average monthly precipitation and
temperatures to calculate average monthly evapotranspiration rates and
percolation rates. As a result, the percolation model does not consider the
single storm event. Infiltration calculations based on single storm events may
yield higher computed percolation rates. Also, the percolation model uses only
precipitation as *a water input. Additional surface water recharge can be caused
by irrigation related to landscaping. Based on these factors and conservative
engineering judgment, the FS used a percolation rate of two inches/year.
S. C?nnatnE; Th* worst-case scenario is inconsistently applied for soil
remediation levels. The 1 ppm TCE soil remediation level for inside the slurry
walls is based on the implicit assumption that those areas will remain under
industrial/commercial control necessary Co maintain effectiveness of the slurry
walls.
EPA Reaoonaa! A residential reasonable worst-case scenario was uniformly applied
throughout the MEV area. The 1 ppm TCE cleanup goal was based on the added
degree of protection provided by the slurry walls and the continued monitoring
and pumping which will be part of the overall remedy, regardless of the existing
or potential land use.
6. Comment: The worst case assumption stated in the FS at Appendix Q uses a
retardation factor of 6.0. Based on Appendix P-A, the worst case retardation
factor discovered by the analysis lies at a minimum range of 6.5-8.5 as measured
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by laboratory data and at 7.0 aa measured by field data. Any calculation*
involving worst case a*«uaptions should ua« thasa higher retardation factors.
EPA Raaponae! Table Q-9 is based on R of 12.0. Usa of a R of 6.0 is
conservative but certainly not worst case. Many adsorption R values may be as low
as 2.2 for ICE. Oesorption R values nay be ouch higher. "Worst ease* analysis
should use lower R values not higher as implied.
7. cinrnnTn' The soil remediation analysis is ostensibly calculated so as to
demonstrate protection of the underlying aquifer as measured by a health based
concentration of 5 ppb TCE in the aquifer. On this basis, the FS concludes that
O.S ppm TCE in soil is an appropriate soil remediation level. However, the
solution to the equations provided in the analysis have apparently been solved to
result in no more than 4.85 ppb TCE in the underlying aquifer.
EPA Response: The difference between 4.85 and 5.0 and the use of "standard
scientific conventions* (i.e., significant figures) versus "nonstandard
convention* is trivial and meaningless to argue over given the accuracy of Che
methodology and the assumptions. For example, the difference between 0.0111 and
0.0112 (the dilution factor) is not meaningful or the difference is not
significant.
8. Comment: "... the FS incorrectly calculates the value for (Q ln)H. . ."
EPA Response: The referenced calculations have been reviewed and found to be
correct. A typographical error exists in (Qin)R. which should be expressed in
ftVyear. Despite the typographical error, the correct units were actually used
and the calculation in the FS are correct as stated.
9. Comjatnt ' "... the actual analysis provided to support the soil
remediation level is expressed as a concentration of TCE in soil per specified
unit of available square surface area through which percolation nav occur. Based
on this analysis, it is inadequate to express the remediation level for the
entire site without reference to the corresponding surface area."
EPA Response: Using the site specific approach given in Appendix Q requires
areas of contamination to be used in the calculations. A similar calculation can
be made using percolation through a unit surface area through a given mass
resulting in flux into groundwatar. The remediation levels calculated from these
approaches are presented in terms of mg/kg. Soil clean- up levels need to be in
terms of mg/kg for application of an area-wide clean-up goal and for verification
of remediation.
10. Comment : The FS is unclear as to the use of recommended soil cleanup levels
(RSCLs).
EPA Response: RSCLs were not used to determine soil cleanup levels at MEV. In
fact, RSCLs are outdated and are no longer used, even by the California
Department of Health Services.
13
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11. Com«ne: Siltac recommended that a cleanup level greater than 1 ppm for TCE
be aet, baaed on aoil cleanup lave la "found at" other relevant Superfund sites.
The aitaa referred to are found in New Hampshire, Rhode la land and Michigan.
EPA R««non«ft' A cleanup level establiahed for one aita (especially in another
part of the country) ia not naeoeaarily adequate at other altaa. Site
characteriatics can vary greatly (e.g., aoil, groundwatar, geology, affected
populations, etc.) and, therefore, each aite must be evaluated on a caae-by-case
baaia.
11. Comaene: The RZ report incorrectly stated that Siltac used TCA.
EPA Response: Comment noted, however, EPA in its) August 8, 1988 approval letter
for the RZ atatad, "EPA neither agrees nor disagreea with the assumptions or
aasertiona regarding 'inferred aoureaa' or 'other PRPs' as praaented in the RI
report."
13. Comaene: "... TCE contamination in the groundwatar is not attributable to
leaks from an above ground atorage tank and groundwatar flow beneath Siltec
property is to the northeaat."
EPA Response: See above response. In its RZ approval latter, EPA alao stated,
"EPA neither agrees nor disagreea with the configuration and boundaries of the
chemical plumes, or with the graphical interpretation of the potentiometric
surface/water table of each aquifer as preaented in the RZ report." "The
configuration and boundariea are, however, adequate to evaluate remedial
alternativea." The pointa raised by Siltec are minor since they deal with only a
small portion of the MEW area, and therefore are unlikely to have any bearing on
the selection of remedial alternatives for the overall area. Furthermore, veil
elevation data and TCE concentration contour plumaa have been reviewed and the
data substantiates that the groundwatar (in the ahallow aquifers) flows in a
north or northwest direction, consistent with the RZ report.
14. Comment; Soil remediation at Siltec would be unnecessary if soil
remediation levels were "properly derived", therefore, the statement in the FS
that on-site soil remediation is necessary at Siltec ahould be stricken from the
text.
EPA Response: Soil remediation levels for the MEW area have been properly
derived. Individual sites which will require soil remediation will be determined
by EPA on a case-by-caae baais.
IS. Comment: Siltec believes that the effects of sanitary and storm sewers as
potential conduits in the local study area (LSA) have not been adequately studied
and that further investigation nay show that sewers in the LSA do act aa
conduits.
EPA Response; An adequate evaluation of potential horizontal conduits waa
performed by Fairchild, Intel, and Raytheon as part of the RZ. The reaults of
the investigation were included in the RZ report. The report concluded that
horizontal conduita (at leaat within the local study area) are not a problem. If
Siltec wlshea to perform an additional study, it may do ao during RD/RA.
14
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Ttiu Following Selected Comments Were Submitted bv the League of Women Voters
1. Comment: Identification of all the responsible parties should be expedited
to increase the financial resources needed for cleanup. "Close monitoring by EPA
is also essential to guarantee that all polluters have been identified and are
participating in the cleanup."
EPA Response: EPA has issued "Special Notice" letters for cleanup liability to
17 Potentially Responsible Parties (PRPs) in the MEW area. Agency negotiations
with the PRPs for cleanup and oversight costs will commence shortly. In
addition, as cleanup progresses, monitoring data will be evaluated to determine
if other sources have contributed or are contributing to the MEW contamination.
2. C?nBftnt: The League agrees with the "pump and treat alternative* for the
shallow aquifers.
EPA Response; Comment noted.
3. C.grayiT;: The Proposed Plan should identify ways of reusing extracted
groundwater.
EPA Response: Groundwater reuse is currently being evaluated and will be
incorporated into the ROD and the RD/RA Consent Decree.
The Following Comment3 Uere Submitted bv the U.S. Maw
Ceneral Comments
1. "Unlike other FS reports, this report does not present supporting engineering
calculations on treatment sizing, pumping requirements, simulated drawdown cones,
or construction materials and methods. As such, the document is generic in
nature and essentially requires the reader to assume that the black box system is
optimal."
EPA Response: Such detailed design information is cypically n££ provided in the
FS because it is unnecessary, and consequently will be presented during Remedial
Design (RD).
2. "The report does not present specific design information for water treatment,
soils aeration, and several other alternatives discussed. Without this
fundamental information, it is impossible to critique the authors conclusions."
EPA Response: The Information presented in the report is sufficient for
evaluating various alternatives. Specific design information will be presented
during RD.
3. "A groundwater model is not specified, and pumping specifics (e.g., rate,
duration, equipment) are not provided."
15
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EPA Response: The information regarding the groundvatar model can be found in
Appendix P of the Feasibility Study.
4. "Offsic* remediation ia mentioned throughout the document in a cursory manner,
yet a number of pumping trail* ar« ahown on MAS Moffett Fiald property and a
treatment system ia ahown on NASA property. How waa the information gathered in
the MAS Moffott Field Remedial Investigation incorporated into the treataenc
designa and ground water extraction schemes?"
EPA Response: Aa the FS report states, the number and location of pumping walla
and treatment systems is for costing estimates only. The actual number and
location of these units will be provided during RD. Also, site specific sources
on Moffatt Field were not incorporated into the treatment designs and extraction
schemes.
5. 'The document does not present information as to die potential timing for
installation of off site or on site remediation. Due to other investigations
currently ongoing, extensive coordination is needed. To data, what coordination
is proposed?*
EPA Response: Timing and coordination for well installation will be part of the
Remedial Design and Remedial Action (RD/RA) negotiations process, and therefore
are not incorporated into the FS.
6. "It waa difficult to determine if the unsaturated zone model is accurate
without supporting calculations. In addition, how is differentiation made
between vapor phase transport and liquid phase transport?"
EPA Response: Supporting calculations for the unaaturatad zone model are found
in Appendix P of the FS. Vapor phaae transport waa not considered.
Executive Summary
I. "ES-1. Uncontrolled sources are cited aa present and impacting potential
remediation. These sources are not clearly defined in the text nor are their
impacts."
EPA Response: Uncontrolled sources will be defined during the RD/RA phase and as
other PRPs are included in the process.
2. "ES-1. It is stated that the FS ia designed to adequately address unknown or
uncontrolled sources of pollution. No reference waa found in the text that
presents how uncontrolled sources are handled in the FS design process."
EPA Response; See response above.
1. "ES°2. Chemicals have been detected in all S aquifers. Waa there any
investigation aa to the vertical distribution of chemicals in any of the
aquifers, particularly the C aquifer?"
16
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EPA Response: Section 4.0 of the Remedial Investigation Report (July, 1987 and
revised June, 1988) contains the results of a thorough investigation of the
cheaical distribution in soils and groundwater in all aquifers.
4. "ES-2. How was the total volume of TCE, TCA, etc. calculated? This was noc
described in the text."
EPA Response: The estimation of volunes of chemicals in various aquifers is
described in Section 4.3.2 (pp. 4-63 through 4*66) of the RI Report.
5. "Shallow aquifers beneath the sita are eitad by the RWQCB as being a potential
drinking water source. This argument appears unfounded since the general water
quality is poor and the aquifers thin, discontinuous, and low yielding. How much
potential does EPA or RWQCB see for the shallow aquifers being utilized as a
drinking water source?"
EPA Response: While the water quality and yields of the shallow aquifers may be
lesser in relation to the deep aquifers, the shallow aquifers near the site have
been used for drinking water in the past, according to the Santa Clara Valley
tfacer District. Although currently no one is using the shallow aquifers for
drinking water, the aquifers do meet EPA's groundwater classification criteria
for potential drinking water sources and are also protected under the RWQCB's
Basin Plan and Non-Degradation policy. Both agencies regard the shallow aquifers
as a resource that should be protected and restored.
6. "ES-5. The upper foot of soil is not considered for remediation bas«ci on
health risk. Was potential leaching of these materials and subsequent
concentrations in lower zones considered?"
EPA Response: The Endangeraent Assessment prepared~by EPA concluded that there
is very little contamination present in surface soils, therefore, leaching (from
the surface soils) is unlikely to be a problem.
7. "ES-7. Throughout the document, maintaining an inward and upward hydraulic
gradient has been discussed. However, calculations on how much water should be
pumped to establish this gradient or exactly what minimum magnitude of the
gradient is necessary but not present.*
EPA Response: Water pumpage will be determined during RD/RA.
Chapter 1
1. "P12. Recent groundwater extraction from within the slurry walls is
presented. There does not appear to be any reference in the text as to the
quantity of water being pumped or the quality of effluent. This type of
information is critical in evaluating appropriate remedial alternatives. No
reference is made as to the established NPDES levels to Stevens Creek or the
POTV. This information is vital in establishing cost effective disposal
options."
17
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EPA Response: EPA does not believe that this information is necessary for the TS
report. The information will be provided during the RO phase. NPDES levels may
be obtained froa the RWQCB.
Chapter 2
1. "P-17. Three additional recovery wells were added in 198S. What was the
rationale behind their installation? Where are they? Do they all couple into
one treataent system? If so, was the original system redesigned? Where is the
treataent aystea?"
*
2. "P-17. Twenty-one (26?) recovery wells are apparently now operating. A
scheaatie of the operating systea(s) is essential along with design details and
rationale. Nona of this information is provided y^lrg a good review of
additional pump and treat scenarios difficult."
3. "P-18. Three stripping towers are said to treat some portion of the recovered
water. What portion goes to the POTW and to Stevens Creek?"
EPA Response: The above information is not necessary for the FS and will be
provided during the RO phase.
4. "P-22. The Raytheon slurry vail is said to partially penetrate the B2
aquifer. Why was the wall keyed into permeable materials?*
EPA Response: This information may be obtained by reading the Raytheon "Slurry
Wall Construction Report" Colder Associates, January 1988, which is-on file at
EPA and is also part of the* administrative record.
5. "P-23. 1,300 Ibs. and 230 Ibs. of VOCs were removed from two plots. What
percentage recovery of VOCs was achieved?"
EPA Rasponsa-L This will not be known until the remedy has been completed.
6. "P-24. In-situ tests apparently suggest an effective radius of influence of
40 feet for venting wells. The specifics of these tests were not presented.
What were the physical soil properties? Soil moisture and temperature? Total
concentration of chemicals in the soil? Generally, in the fine grained soils.
vent veils are placed on 5 to 10 feet centers. Although it is not possible to
check the authors' calculations, previous experience suggests that the vent
system as given may not be adequate."
EPA Response: The information may be found in a report titled, "Soil Vapor
Extraction Study". Raytheon Company, prepared by Harding Lawson Associates dated,
February 8, 1998. The report is available for review at EPA and is also part of
the administrative record.
7. "P-26. The slurry wall around Fairchild building 9 appears to be built
through a highly contaminated area. Why? (See figure 2-1.6)"
EPA Response: This information is not relevant to the proposed cleanup plan.
13
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8. 'P-27. Metals have been detected in the groundwatar but are essentially
discounted because of the statement: "Metals...are not very mobile in
groundwatar.. .V The presence of iMCals in the soils and groundwatar should be
considered in the design of treataent alternatives. Metals present in the high
ppb range may have adverse affects on potential treataent options such as
biological reactors and promote scaling in air stripping towers.*
EPA Response: Metals will be considered during RD.
9. 'P-33. Chemical concentrations were detected in Stevens Creek. What were Che
concentrations of these chemical*? How were these chemicals addressed in NPDCS
permitting at the site?"
EPA Response: This information is- not relevant to the FS. NPDES permitting
requirements may be obtained from the RVQCB.
10."P-33. How were the synergistic and antagonistic effects of the various non
target chemicals addressed when designing water treataent systems? For example,
is fouling of the aeration tower packing material due to high levels of
Inorganics a potential problem at the MEW remediation area?
EPA Response: This information will be developed during' RD.
11. "P-34. Chemicals detected in samples below 10X or 5x associated field blanks
are reported as non-detected. Which specific compounds other than the four
chemicals listed fell under the 10X rule? On what basis was the SX rule chosen?"
EPA Response; This information can be found in the "Endangerment Assessment"
report available at EPA and in the City of Mountain View Public Library.
12. "P-36. The mobility of metals is again mentioned yet there is no discussion
on the redox potential, precipitation or exchange of these chemicals in the
presence of soil components such as humic acids. Lead for example can be
solubilized by some naturally occurring acids and some lead compounds produced
are classified as soluble. If lead is able to come in contact with esmarine
benthic microbes through surface water transport or shallow groundwater flow,
these microbes can methylate lead to form tetraaethyl lead which is volatile and
more toxic. Although situations like the one described are not common, a more
comprehensive review of metals contamination should be considered."
EPA Response: See above response and response to comment 8.
Chapter 3
1. "P-54. In paragraph 2, soil remediation levels are left open, yet all
remedial alternatives are based on 1 ppa and O.S ppa TCE cleanup levels. This
apparent inconsistency needs clarification."
EPA Response: Soil remediation levels inside the slurry walls are "left open"
only if Alternative Concentration Levels (ACL*) are chosen as cleanup levels for
19
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aquifers inside the slurry walls. EPA has chosen Maximum Contaminant Levels
(MCLs) for the shallow aquifers including those located inside slurry walls.
2. "P-37. The federal pre-treataent guidelines for toxics of 1.37 ppa froa
manufacturing facilities would be relevant only if the local treataent works
would agree to use this guideline."
gPA R««pon«a; Correct.
Chapter 3
1. "P°92/106. In*situ biological treataent is considered only to a very limited
extent. Specifically, the authors address biodegradation in an undisturbed
state. Further they discount this option quickly by citing a single study
performed by Stanford University. No significant conclusions were drawn froa
this work.
Aerobic biodegradation can be perforaed using an above grade landfaraing
technique. This technique is very successful with aroaatie hydrocarbons and
would augment soil aeration. The technique can be used with similar farm
equipaent employed by the aeration alternative. Although biodegradation alone is
not a plausible solution, biodegradation using marine bacteria, sewage sludge or
some strains of soil bacteria can enhance the remove of chlorinated alphatics
sorbed to the soil matrix and should be considered."
EPA Response: Comment noted.
2. "P-95. On site treataent options deal exclusively with volatile compounds. «.
The extracted water streaa will contain numerous other eheaicals such as iron,
magnesium, calcium carbonate, and heavy metals. These compounds must be treated
prior to entry into an aeration tower to prevent fouling and to promote treataent
to the limits set. Treataent units including precipitation tanks and mixers, in
line filtration, and multimedia filtration should be addressed."
EPA Response: This will be addressed during RD.
3. "P-101. The cheaical characteristics listed are properties associated with
volatilization and sorption. Characteristics such as pH, TDS, BOO and TSS need
to be quantified prior to design of water treataent."
EPA Response: Comment noted.
4. "P-103. The contention that additional surface capping would have a minimal
influence on infiltration should be supported by calculations provided in the
document."
EPA Response^ Most of the site (approx. 80%) is already capped. Therefore,
additional capping will have little, if any, influence.
5. "P-104. It is contended that excavation would require demolition of several
buildings. Which buildings?"
20
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EPA Raaoonae: Potentially, any building .situated over soil contamination.
6. "P-105. Limited space available for stockpiling toils is given as a reason to
discard excavation, yet landf arming soils for volatilization of organic* is
passed through for consideration. If space is limited, where would the above
grade landfaraing be accomplished?'
BPA Reaoon««; This information will be developed during RD.
7. "P-108. Aeration is described as not being effective on phenol. However, no
treatment method is offered for phenol in lieu of aeration. Why?*
EPA Response; As phenols in soil have not been quantitatively defined,
information will be developed during RD, and incorporated as necessary into the
treatment methods.
8. *P-108. What constitutes successful dewatering? (para 4). If vapor
extraction is to be successful, what is the maximum residual water content in
sandy soils? Cohesive soils?"
EPA Response: This information will be developed during RD.
9. "P-108. Adverse settling due to dewatering was encountered. What was the
magnitude of this settlement? Why was this situation not reviewed in Chapter 9
with respect to the long term pumping scheme?*
EPA Response; It is not known if settlement was due in part, solely, or at all
because of dewatering. Additional information will be developed during RD/RA.
10. "P-108. It is stated that settling will not affect slurry wall integrity.
Were calculations performed to support this contention?*
EPA Response: The FS Report states that settlement conditions are not expected
to affect the integrity of the slurry walls. Calculations to support this
conclusion were performed by consultants for Raytheon independent of the FS
report.'
11. "P-109. The report claims that in-situ aeration is applicable to soils
beneath buildings. It is not clear from the supplied figures how soils beneath
buildings are being remediated.*
EPA Response: Soils beneath buildings are not currently being remediated. Those
areas will be addressed during RD/RA.
12. "P-109. What are the serious concerns about steam injections?*
13. "P-109. What are the potential adverse effects of steam flushing? They are
not presented in the discussion.*
EPA Response: The concerns about steam injections are that the levels of
development and field experience are minimal. Massive injections of steam would
result in the significant elevation of subsurface soil temperatures and pore
21
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pressures under structures on the site. These temperatures and pressures could
result in possible injuries to personnel and disruption of industrial operations
due to 1. heave or settlement and/or 2. the accidental uncontrolled release of
steam to the surface.
14. *P-H2. The arguments that flushing may increase the boundaries of chemical-
bearing groundwater and that the flow injected water cannot be controlled are not
valid. If injection wells are properly placed upgradient of the plume and
extraction wells placed downgradient, a closed loop system can be maintained.
Flushing incrasses the hydraulic gradient and can substantially reduce
remediation time. Further, flow controllers connected to sensors in monitor
wells can maintain a predetermined hydraulic head.*
g?A Response: Sections 5.3.11, 5.3.25, 6.2.9, 7.2.2.4, and 7.2.3.4 of the FS
explain why flushing is not considered for site remediation.
15. *P-112. 1. It is stated in the FS that it is unlikely that enough water
could be injected to alter the piezometric surface. This argument contradicts
the previous statement regarding complex stratigraphy. The aquifers are low
yielding, discontinuous and relatively thin bedded. All of these physical
characteristics suggest an induced head could be applied. 2. Were calculations
performed or a flow model used to show the effects of water injection?*
EPA Response: 1. The text of the FS does not contradict the above statement.
The text does state that due to the 'extremely variable permeabilities ... it
(is) impossible to ensure that adequate flushing rates can be maintained in all .
. . areas. Also, it is unlikely that it will be possible to inject groundwater
at a rate that would significantly alter water levels or piezometric surfaces in
areas not in the immediate vicinity of the injection well*. 2. No.
Chapter 7
1. "P-160. An 80 foot square grid would be required according to section
7.2.1.2. Earlier in the report, a 35 foot spacing was presented.*
EPA Response: The exact spacing is unknown st this time, but will be determined
during RA.
2. "P-160. In figures 7.2-1 a-c, extraction wells are shown but air inlet wells
are not shown. The text describes inlet/extraction wells. Is this a pump in,
pull out process or just vapor extraction?*
EPA Response: The process will be determined during RD.
Chapter 9
1. "P-260. Stevens Creek is proposed as the ultimate receptor for treated
groundwater although it is not specifically stated in this chapter. How will the
added flow affect the stream channel?*
EPA Response? AS described in Section 2.2 (pp 2-4) of the RI Report. Stevens
Creek is an intermittent stream. Therefore, the addition of a year-round flow of
22
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treated groundvatar from MEW Area remedial Actions might change portions of the
creek downstream of groundvatar discharge points to a perennial condition, to the
extent that the discharge flow exceeded local stream bed percolation capacity.
However, the proposed flow of treated groundwater is not expected to be large
enough, when compared to normal stom run off, to materially affect the channel.
2. "P-260. Haw channel hydraulics been modelled using the HEC-1 or similar
flood routing scheme to ensure that the added vater trill not create a local
flooding problem?"
EPA Response: No.
3. "P-243. Seven tenths of a pound of TCE is considered to be de minimus. How
is this value calculated (weight or volume basis)? What criteria is used for
determining the volume or weight to test?*
EPA Response: The term "de minimus* was developed by Fairchild, Intel, and
Raytheon to describe certain "minor" contaminated areas. EPA does not use this
terminology to describe contaminated areas. Calculations and criteria may be
found in Appendix 0 of the FS report.
4. "P-245. How was the pumping scheme outside the slurry walls designed to
ensure that an upward gradient is maintained inside the slurry walls? If the
groundwater surface is sufficiently suppressed outside the walls then inside
pumping is negated."
EPA Response: The gradients are currently being monitored and will be monitored
during RD/RA.
S. "P-260. Why are only Bl and A aquifer wells proposed offsite in the
downgradient direction?"
EPA Response: Because there is no contamination downgradient in the B2 and B3
aquifers.
6. "P-260. What is the rationale for placement of wells within NAS Moffett
Field? Vas flow modelling performed?"
EPA Response: Veils were placed in relation to the contamination plume. Flow
modelling was not performed.
7. "P-260. Since chemical transport modelling was accomplished in only two
dimensions, how were the effects of drawdown of chemicals through shallow
aquitards considered?"
EPA Response: The effects of drawdown of chemicals through shallow aquitards
were not considered since the model assumes that the aquifer is confined.
8. "P-261. Air stripping and activated carbon filtration are listed as treaonenc
components. Will these systems require continuous monitoring?"
EPA Response• No.
23
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9. "P-261. What ara the eatimated carbon uaa rataa and packing Ufa apana? Vhae
other componenta coapriaa tha treatment ayatama? How awch araa will ba
required?"
10. "P-261. How will utilieiaa ba handlad for tha off aiea aystema?"
11. "P-266. Vhae la tha rationale for tha placaaant of tha thraa "C* aquifer
walla? What ara tha propoaad pumping rataa? Will tha higher volume pumped from
tha "C" aquifar have a tendency to dilute the waata atraaa from tha lower
yielding upper aquifar walla? If aot what la tha expected average concentration
of ehemicala on tha influent aide of the air a tripper?"
EPA Raaponae: The information for quaationa 9-11 will ba developed during RD.
12. "P-267. Tha Operation and Maintenance coata are not well defined in the
appendieea. How waa tha 2.9 million dollars of annual 0£M derived for the off
aite remediation acheme? How many treatment ayatama ara included in the off alte
program?*
EPA Reaoonaa: The O&M coata ara adequate for the purpoaea of tha FS. The axacc
number of treatment ayatama will be developed during RD.
13. 'Figure 9.2-4. Some fairly axtanaive piping la ahown on HAS Hoffatt Field
property. How would this piping be inatalled? Have the numeroua aubgrade
utilitiaa on the facility been factored into the eatimatad coat?"
EPA Reaponaa: The drawn piping la a conceptual daaign and tha Installation will
be refined during RD. Yea.
24
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ADMINISTRATIVE RECORD IMDBX
-------
REVISION BATE: 05/22/89
Niddlefield-EKia-wfciaMan ATM Superfund Sit*
Mountain view, California
«•• AdBiniatratiwa Record Index •••
PACE: t
t 04/11/76 NatcoiMI
Santa Clara Valley water Oiat.
County Sanitarian*
well Seating Inatruetion*
02/08/85 Roger I. Jamt
n
Mr l««fan
T«nt«tf«* Ordtr
03/20/85 PIMM Mrkfra
i.v.a.e.i.
Sf B«y ffcgian
Oanctd 0«(k»
t.v.o.e.i.
SF B«y Bcflian
••part* for
Nowitain vf«w
M/22/85 Thaw* MHtfn*, lottr >o««r JMH
F«(dMn, Lwrtne* Kotb R.U.fl.C.B.
R.U.Q.C.B. Sf fey ••gion SF Say Region
Faircfeild, Intel. MCC,
••yttMon, Siltae, Mountain
Vfm, Santa Clara Co.
Ot/30/85 I.U.a.C.I.
SF fay Region
07/26/85 Gordon Snow Ctam rfatntr
RaMurec* Agency 91 California EPA Region 9
Fairenild, Intel, M6C,
laytfMon, Si I tee. Mountain
Vfen, Santa Clara County
for Site Cleanup
State Review of Mountain View
Five Superfund Project
08/15/85 Harding, lawaon Aaaoe.;
Canonie Engineers
8 08/15/85 EPA Region 9
EPA Region 9
Intel, Fairdiild t Raytfceon
Work Plan ReMdial Invcstig.
Feaaibility Study and Oper-
ational unit Feaaibility Study
Niddlefield EUiftfiiaawi Area
Adafniatrative Order on
Conaant
75
22
08/15/85 Koyd R. Day
Cooler, ffodMard, Caatro,
Nuddleaon « Tatu*
Crfc a. lappaia
Harding,
Mountain View RI/FS
O.U.F.S.
08/31/85 Terrene* J. NeManua
Intel
Clewv Kiatner
EPA Region 9
Project Schedule
It' 09/06/85 Terrene* NeManua
Intel
filam Kiatner
EPA Region 9
Project Schedule
-------
REVISION DATE: 05/22/89
Niddlefleld-EUIa-Vhiaasn ATM ****** Site
Mountain View, California
•*• Adainiatrative Record Irate ••»•
PACE: 2
09/25/85 Cmnie Engineers
TO/OtCAM12ATIOM
ETA Region 9
OCSOHPTIOJI/SUSJECT
Addendum QAIQC Plan Existing
Monitoring Walls RIFS Niddle-
flold-EUia-WhiaaBn (MEW)
Area
PACES
175
13 09/25/83 Steve OobHjevic. Phillip
AntoaBeria
Canonic Engineers
Intal
Monitoring Report Remedial
Investigation Feasibility
Study Data Through July 1985
175
14 10/28/85 Jawa NeClura, Erie Lappala
Harding Lawson Aaaoe.
EPA Region 9
Technical Mem: Well Inventory
Niddlefield-EUia-Whii
Study Area RI/FS
25
15
11/15/85 Canonie Engineers
Intel, Fail-child ft Raytheon
Soil Evaluation Report
Remedial Investigation
Feasibility Study
Voluaa I
175
16
11/15/85 Canonie Engineers
Intel, Fair-child ft Raytheon
Soil Evaluation Report
Reaadial Investigation
Feasibility Study
Voluaa II
175
11/15/85 Canonie Engineers
Intel Fairchild ft Raytheon
Soil Evaluation Report
Remedial Investigation
Feasibility Study
Voluw III
150
18 11/22/85 JaaM NcClure, Eric Lappala
Harding, lauson Assoe.
EPA Region 9
Technical Mean: Potential
Conduits Evaluation Middle-
field Ellis-UhisMn Study Area
35
19
11/26/85
Clam Kistner
EPA Region 9
Terrence NcManus
Intal
EPA CosMnts on the Database
MeneojSBant Systaai Plan,
Hydrogeologic Model Plan,
Wall Inventory
20
12/00/85 Canonie Engineers
Intal, Fairchild ft Raytheon,
Si Itec
Puaping Test, City of
Mountain Vie*
Wall Mo. 18
200
21
12/20/85
Glenn Kistner
EPA Region 9
Terrenes
Intel
Preliminary Definition of
Remedial Action Objectives
MEW study Area
Mountain View. CA (caver Itr)
22
22
01/00/86 Canonie Engineering
Fairchild
Puaping Teats Interia Reaedial
Prograai Mountain View Facility
Voluw 1 of 2
300
-------
REVISION DATE: 05/22/89
OOC f gATJ
23 01/00/86 Canoni* fflfinaars
PAGE: 3
Maaan ATM Suparfund Sit*
Mountain Vfw, California
Administrative Racerd Indai •••
TO/ORCA«I2AT10M
Fatrchlld
Puiping Taats tntaria
•••dial Progrs*) Mountain V{«M
Facility VOluaa 2 of 2
300
2* 01/28/96 fitam Kistnar
EPA Region 9
Intai
9ft taaaanri to tha Niddla-
ffatd^tlfc-tfifnan Stuoy Araa
•Soil Cwatuation Kaport*
01/28//86 61am rfstnar
EPA laaion 9
Them Trapp
Lanaala Kpiay I Oi
Additional E»A
eanearnina ttia •Soil
Evaluation Raport" and
Fairehild
27
28
29
30
31
01/30/86 Clann Ktttnar
EPA Raaion 9
02/00/86 Canonfa
02/25/86 CatnaHna Hanridi,
Erie Lappala
Harding LatMon Assoe.
02/25/86 Harding lawon Assoe.
02/27/86 Canonia Enginaar*
for Intal, Pairetiild t
02/27/86 Ptiiltp U rttzHatar
Hardinf UMon Assoe.
Tarranea MeHanua
Intal
Intal. Pairdifld A Isytfcaon
EPA Ration 9
EPA Ration 9 .
U.S. EPA
Clam Clstnar
EPA Ration 9
EPA Oaavants on ttia "Existing
Data taviaM" for tha Niddla-
fialct-ClliS'UhisMn Study Area
Mai Inwaatigation
Historic now Analysis
Rydrogaologic Nodal Oaserip*
lion Raaadial Invastigation
FaaaiMlity Study
Third Quarterly Raport "Re
ial Investigation Feasibility
Study Nfddlefield-EUis-
Wnisaen Study Araa
Tables Third Quarterly Raport:
Remedial Investigation/Feasi-
bility Study Niddlefietd-EUis
Uhisaan Study Araa
Respensee to EPA Conaents on
the Niddlefleld-EUis-Vhisoen
Are* RI/FS Soil Evaluation
Raport
Transsrittal: Reports In reply
to EM caeBents on the "Soil
Eveluatlo
17
100
60
.15
32 03/12/86 Clam Kistnar
EPA Ragion 9
Larry Avon
Fairchild
EPA and Coapany Agraaawits
33 03/26/86 Catharina Harwich,
Erie Lappala
Harding lawaon Assoe.
Clam Kistnar
EPA Ration 9
Transaittal: Chronology of
Evants and Chaaieal Rasults
fraa SUI-230. RJC and 84C
-------
REVISION DATE: OS/22/89
MlddUfiald-Ellfs-UMaaan ATM Superfund sit*
Mountain view. California
••» Administrative Record In** •*•
PAGE: 4
QOC f DATE FROM/0»aunZATIOM
34 03/28/86 Ql«n Kleiner
CM legion*
TO/mCAKtZATiai
Larry Asian
Intel
Initial Screening of
Alternatives
PACES
4
35 04/03/86 Clam rtstner
EPA Region 9
tarry
Fairchild
Delay re Aqulfior Taat Report
04/04/86 Cltm KUtrwr
EM Raaion 9
Larry Aaon
FaircftUd
EPA'a draft eoMMnts on:
•Monitoring Network u«tl
SxaMf)• Historic Flow Anal-
ysis Hydrogaotogie Model
10
37 04/04/86 Ronald Stoufer t Phillip
Fftzwater
Harding Lauaon Aasoe.
Raytheon
Ptias* IV Siteurfaee Investi-
gation Raytheon 350 Ellis St.
Mountain view, Ca.
150
38 04/07/86 JaMS Wilson, Erie Lappala EPA Region 9
Harding Lawaon Assoe.
05/00/86 International Tedinology Intel
Quality Assurance/Quality Con-
trol Plan: Remedial Investi-
gation Feasibility Study and
Operable Unit-Feasibility
Subsurface Soil Re
Intel
Mountain view, CA
Jiation
135
310
40 05/02/86 Michael Rosa
Raytheon
Glenn Kistner
EPA Region 9
RI/FS Schedule
41 05/09/86 Clem Kistner
EPA Region 9
Michael Roaa
Raytheon
Deep Well Monitoring Program
42
05/13/86 Canonic Engineers
Fairdittd
Investigation of Welt 652V22A3
Silva Well, Remedial Investi-
gation Feasibility Study
Middtefield-EUis-Whisaan Area
32
43 05/20/86 Michael I. Rosa
Raytheon
Jiai Crove
EPA Region 9
Deep Aquifer Monitoring
Prograai
05/21/86 Dennis Fesoire
Canonie Environasntai
File
Attachawtt • Contact with
Garcia Well and Puap Ca.
-------
KEVISIOft DATf: 05/22/89
PAGE: 5
Ntddlefleld-ffllis-Whiessn Are* Superfund site
Mountain View, California
*** Administrative^ Record Index •**
ooc f
45
09/27/86
05/27/86
Steve) Oobrijevfc
Mil dp Antocavrla
Canonic Engineers
Stevo Oobrijevle
PnilllpAntomeria
Cemanle Engineers
06/00/86 Canonic
Palrcftlld
Larry Awn
Fofrenltd
Inttl.
« Icythoon
Statw lopart rolrehitd
Nouttaln Vf«H raelllty 9/1/89
thraajn 3^1/86
Vol. I
Status Hport rsfrdiltd
Mountain V|«M Facility
9/1/89 ttirouBh 3/31/86
Vol. 2
t«Mdlal Iiwntigation
Feasibility Study
300
15
06/00/86 Canonic Engineers
49 06/00/86 Canonic Engineers
50 06/00/86 Canonic Engineers
Fairdtild
Fairehild
Fairdiild
Draft Report: Interim Rcaodial 10
Actions Fairchild Scaiconduct.
Nt. View Facility
Voluac 1 of 3
Draft Report: Interiai Roaedial 200
Actions Falrchild Seaiconduet.
Nt. View Facility
Vol. 2 of 3
Draft Report: Interiai Raaodial 400
Actions Fairchild Seaiconduct.
Nt. View Facility
Vol. 3 of 3
St 06/02/86 Bryan lector
Intel
52 06/05/86 Nicnaet losa
Glenn Kistner
EPA legion 9
61cm Kfstncr
EPA Region 9
Intel Grounduater laaadial 250
Actions Attached: GroundMoter
Rcaadial Actions Finsl Ptiaae
3/19/86
Schedule for Saopling Round 200
3.5 Nlddlefield-£llis*Whisaan
RI/n
53 06712/86 P.JC. ChattopsaHysy
ecology « Envl
Jla Wilson
Harding tataon Assee.
Roqusst for Laboratory
Analytical ROM Oata
Mountain Vie* site
54 06/16/86 Robert P. Stern
EPA legion 9
Mountain View Cleanup
35 06/17/86 Terry Wilson
CPA legion 9
Press <
Rel
EPA Request Public
On Falrchild Groundueter
Cleanup Plans in Mountain view
-------
•EVISION DATE: 05/22/89
Middlefleld-EIKs-UMesen Area Super*** Sit*
Mountain View, California
•*• Administrative Record Irate *••
PAGE: 6
30C* gATJ
56 06/25/86 Michael
57 07/00/86
Glenn Kiatner
CM Reg Ion 9
Notification of Additional
Grounduater sampling for tho
•I/PS
i Arto
RI/FS Utii Inwitory Stawry
Production Woii*
28
58 07/00/86 Canonio Enginters
59
60
07/00/86 Canonio Enginmr
07/07/86 Niehoot Kont
Citizom for a totter
Foirctittd
Fairetiild
lobort Storn
EPA
Parking Structure Private Well
Investigation* and Proposed
Well Sealing Plan NEW
Area, Nt. View, California
Deep Wet l clutter Muaber 3 OW3
Installation t Puaping Chrono-
logy Niddtefield-Ellia-Whisman
Area Mountain View, CA
FaircHHd (nteria Remdtal
Action Proposal
07/08/86 fit am Kistner
EPA tegion 9
Michael Kosa
Well Inventory i Potential
Conduits Evaluation
07/23/86 Harry Seraydarian
EPA Region 9
Larry
Oiamd (
Interiai ft
Report
ial Actions
63 07/24/86 Phillip Antcewia
Canonie Engineers
66 07/28/86 Michael IOM
taytneon
Raytheon
Glenn Cfstner
EPA legion 9
8-C Acuitard Soil Cheaicat
Analysis Results Niddlefield'
EttiS'WhisaHjn Area Mountain
View, CA
Draft Nap showing distribution
and classification of walls in
NEW study Area
.60
65 07/29/86 Michael «o
Raytheon
Clam Kistner
EPA Region 9
Lost Wells
08/00/86 Canonie Engineers
Intel, Fairchild A Raytheon
Soil Saapling and Analysis
Remedial Investigation
Feasibility Study
-------
REVISION OATf: 05/22/89
PAGE: 7
NiddlefUld-EUU-UJiiaaan Area Superfund sit*
Mountain vie*. California
••• Administrative Record If
ooc •
67
08/20/86 Eugenia ZoHdl
Harding
TO/ORSAMIIATiai
aiom Kistner
EPA Ration 9
Tranaaittal of Status Report
Uatar Quality Suaaary 350
Cilia St. Mountain view, CA
8-8-86
PACES
135
68
08/23/86 Mi duel Roaa
6lam Klatnar
EM Ration 9
to July 8 KM lattar
on fotantial Conduits
15
69 09/04/86 Harding lanon Assoc.
70 09/OS/86 Canonia EnvironMntal
71 09/17/86 Glann Ktttnar
EPA Ragion 9
EPA Ration 9
Fairdiild
Nlenaal 8. Roaa
Raythaon
Saaplint Plan: Rawdiai Inv««-
tigation Faaaibility Study
Niddlaf f atd»EU is-WhisMan
Study Araa Mountain V{*M, CA
Evaluation Raport Stavana
Crack Reeharga: GroundMatar
Traataant Fairdiild Mountain
Viaw Facility
8*27-86 Taehnical Maating of
tna Aaanciaa and Coapaniaa
210
09/26/86 Clam Kiatnar
EPA Ration 9
Nfchaal Roaa
Short and Loot Tara Aquifiar
Taat Raport
11
73 . 09/30/86 David K. Rogara
Tha Mark Group
Iryan Raetor
Intal
Transarittal of Suaaary Report
Soil And Grounduatar Data
Intal Sita Mountain Vim, CA
200
74 10/07/86 Stavo Oobrijavie & Phillip Hiehaal Roaa
Antoaaaria RaytHaon
Canonia Enginaara
to EPA Coaaanta on
tna Construction Out Multiple
Monitoring Walla in a Single
25
10/U/86 Stavo OobHJavic
Phillip AhtoBBaria
Canonia Environaantal
larkina
R.U.O.C.I.
Additional tnfonaation
Pertainint to Stavana Creak
10/20/86 Stavo Oobrijavic
Canoni* Environaantal
C.R. loatic
Fairehild
•on-RI/FS Uatar Quality Data
FaircHild Mountain View, CA
100
77 10/20/86 Eugenia Zorich
jaaaa McClure
Harding Lawaon Auoc.
EPA Region 9
Intaria Round Uatar Quality
Sampling Raport: Raavdial
Investig./Feaaibility StuaV
163
-------
REVISION DATE: OS/22/89
Niddlefield-Ellfa-Whisaan Arc* Superfund sit*
Mountain View, California
*•• AoMnlstratlv* Record Index •*•
PACE: 8
DATE
78 10/21/86 Demis L. Currtn
Canonic Environaantal
TO/arCAHIZATtO*
Glenn Kistner
B»A tcgion 9
Inporv* to 9A
T«dnfeal
tur* PriviM y»((
tfom with
stnx-
PACES
20
79 10/21/86 Oomis Curren
Canonl* Environasntal
80 11/21/86 Ptiillip AntaMssrie
Steve Oobrijevic
Canonie EnvtrorMental
81 11/21/86 C.R. Bostic
Fairehild
6Um Klitnw
C»A «t«ion 9
C.I. tMtie
Clam Kistner
EPA Region 9
to 6PA CoaMnt* T«di>
nleat N«n •«rfcln0 Structure
•rfvvt* Util IrMMtlaations
And PropOMd Welt SM(Ing f»l»n
10
Technical Meao Well Inventory
and Evaluation Update Niddle-
fleld-Ellis-UMssan Area
Renodiel Investigation
Responses to Aquifer Test
Report Coswnts
11
IS
11/24/86 Steve Oobrijevie
Camnfe Enviporawntal
C.R. lostie
Fa i reft i Id
TrartMittal: Observation yells
Pafrehfld Nountsfn view, CA
100
11/26/86 C.X. ftostfc
Fairdiild
12/00/86 Caap Dresser & HcKee
Ctam Clstner
EPA Region 9
EPA Region 9
Water Lewi Oats Frost 1*86
Ttirough 12/86 for the 'c' and
Deeper Aquifer Metis, Remedial
Investigation Feasibility Stdy
Final CoiBunitv Relations Plan
Kiddlefield-€llis-UMsa»n Area
Mountain view, CA
85 12/19/86 Oemis J. Currtn
Canonie Envirorawitai
Clem Kistner
EPA Region 9
Tranaaittal Historic Water
level Data RI/FS
Study MEW Area
200
00/00/00
out of
12/24/86 Kent Kitcfti
EPA Region 9
Alexis Sti
EPA Region 9
Review of Analytical Data Re:
Mountain View Sit* utilizing
Organic* Analysis
Attachments
65
12/30/86
Wells Reeoaajendad Seeled By
tne Companies as of 11/21/86
Mountain View MEU Site
-------
REVISION OATB: 05/22/89
PACE: 9
N1ddlefleld»eUls*VJiiaaan ATM Superfund site
Mountain view, California
••• Adainlstratlva Record Index •••
OATt;
01/02/87 Robert Will!
Ecology
, Inc.
TOAKCMIIZATiai
OtiCf.IPTtO»V««JCCT
GroundMater Sampling Audit
MM Stud? Area
90 01/22/87 Eugenia Zorieh
Javaa NeCtur*
Herding Lmitan
91 01/22/87 Harding I
EFA
EPA
Pourtft MC«r Quality Svpiing 156
lound Mpart fMdUt Invnti'
Oation Faaaibility Study
Nfddlcffatd-eUta-Whftaan Area
Fourth Vatar Quality Saapling 360
lound Report laMdial Investi-
gation Ftaaibitity Study
Niddtafiald-EUia-Uhisnan Arta
92 01/22/87 Terranca NeManua
Intal
6tam Kiatnar
EPA legion 9
to EM'S
Oatanaination of a Clean Wei I
Letter of 12/24/86
18
93 01/29/87 Kant N. Kttcfti
EPA Region 9
02/01/87 Canonie Environmental
95 02/04/87 Clem Kistnar
EPA legion 9
Alaxia Strauas
EPA legion 9
EPA legion 9
C.X. toatic
Fairehild
Ravi en of Analytical Data
Quality Aaauranca Reports
1/6 through 1/29/87
Separata Attachments
325
Technical Naav DIM Wall
Cluster Installation NEW Area
Remedial Investigation
Feasibility Study
Request for Round 3 Laboratory
Data
ISO
96 02/05/87 Clam Kistnar
EPA Region 9
Michael Rosa
Intaria laaadial Measures
97
02/06/87 C.I. IflStie
alem Kistnar
EPA legion 9
Mountain Vie* II/EA/FS
Schadulea
99
02/10/87 Kant Kitchi
EPA legion 9
02/13/87 E.I. leatic
Fairehild
Jaevs Grove
EPA legion 9
Glenn Kistner
EPA Region 9
Review of Analytical Data,
Quality Asauranea Reports
2/3/87 thru 2/10/87
Separata laporta
Detailed Feasibility Study
Analysis
60
-------
REVISION DATE: 05/22/89
PACE: 10
Ntddlefield-eilU-uhiaaan ATM Superfund site-
Mountain Vie*, Cat if omit
•*» Adainiatrative Record Index *••
DOC * OATE FROM/OiOAaiZATIOM
02/23/87 Craig Wan targan
Oreaaar 4 McKaa Inc.
TO/qtCAII12ATIC«
Clam Kiatner
EPA Ration 9
Review of Raythaon Intarii
Hal Mmuri(a)
PA6ES
3
101 03/00/87 Colder Aaaoc.
Raythaon
Interia) Reaadial
I
360
102 03/00/87 Colder Asaoe.
Raythaon
Intariai Ra
VoitaM II
ial Naasuraa
400
103 03/02/87 C.R. loatie
Fairchild
Glann Kistnar
EPA Ragion 9
Tranaarittal SHtae Araa Uatar
Quality Data Mountain Viaw, CA
104 03/03/87 C.R. toatie
Fairehitd
03/11/87 61am Kfatnar
EPA Ration 9
Clam Kfttnar
EPA Ragion 9
C.R. loatic
Fairdiild
to Tachnieal
Short and long tare Aquifar
Taats Raaadial Invaatigation
Faaaibility NEW Study Area
Potantial Conduita Evaluation
("Daciaion Traa")
250
106 03/23/87 Stavo Oobrijavic
Phillip Antoaaavia
Canonia Enviromantal
C.R. Boatie
Fairehild
Statua Report Faircftild
Mountain View Facility 4/1/86
through 12/31/86
Vol. I
125
107 03/23/87 Stavo Oobrijevic
Phillip Antonaaria
Canonia Envlronaantal
C.R. Ooatie
Fairehitd
Statua Report Fairehild
Mountain View Facility 4/1/86
through 12/31/86
Vol. 2
300
108 03/30/87 61am Ktatner
EPA Ragion 9
C.t. loatic
Fairehild
Raqunt for Rounda 3.5 and 4
Laboratory Data
109 04/00/87 Meredith Soli « Aaaoc.
Expanded Pf> Search Mountain
View Sita April 1987
Voluaa I
300
04/00/87 Meredith loli 4 Aaaoc.
Expanded PtP Search
Mountain VieM Site
April 1987
2SO
-------
REVISION OATS: 05/22789
Nlddlefleld-Ellls-Whlsaan ATM ****** sit*
Mountain Via*. California
*** Adainfstrativs (coord Index ***
PAGE: 11
DOC • OATt fiai/OiBAM12ATia»
111 04/02787 61cm Kistnsr
EM teflon f
TO/OROAMIZATIOM
C.i. Sostle
Paircaild
Sealing of Potential Conduits
PACES
3
112 04/06/87 rod
Silicon Valley Toxics
Cooiition •
Robert P. Stem
ETA loflion 9
Nomuin VIoM Ctoonup
113 04/10/87 Jothut I/ Pi
H«U«r, Ehmn.
NeAuliff*
Clorn Kistmr
EPA logion 9
Tour tof. Ho. T-1-3
.2
114 04/13/87 NidMoi Kont
Citizom for • lotti
Emit
Rob Stvrn
EPA Region 9
Intori* Clean i^ Proposal
by RayttMon Nouttain view
115 04/13/87 C.I. lootie
Faireftild
Glenn Klstner
CPA Region 9
Data Verification of Sample
116 04/13/87 Joanua I. Motai
Heller, Ehraan, Uhite
X NeAuliffe
Otem Kistrar
EPA Region 9
Raytheon Slurry Well
117 OS/12/87 Jeff Zelikson
EPA Region 9
Michael Ra
Raytheon
Interia) Raaadial Measures
118 OS/19/87 John Mast
Intel
119 06/05/87 Phi It (p MtZMtar
Lesle*
Harding t
Glenn Klstner
EPA Region 9
Transarittal Laboratory Data
Validation Water Quality Samp-
ling Rounds 3.5 « 4
RI/FS MCW Area
Status Report: Water Quality
and Water Laval Oata
250
06/12/87 John Mast
Intel
Clem Klstner
EPA Region 9
Tranaarittal Selected Organic
ft Inorganic Chearfcals
RI/FS MEW Area
200
121 06/26/87 Colder Assoc.
Status Report Soil Soring and
Monitoring Well Prograa
258
-------
REVISION MTE: 05/22/89
PAGE: 12
Mtddlefteld-Ellia-UiiaMn Area Suparfund Sit*
Mountain View, California
•*• Adainiatrative Record Indn *~
123
06/29/87 Ju( (• T
Phillip •fenarter
Harding
06/29/87 Harding lauaon Aaaoe.
TO/OtQU»MTIO»
Intel, Raytfceon 4 Fair-child
Intel, laytnaon ft Fairchiid
OfSOHPTIOayMJCCT
Mountain Vim Wall 18 NV18
Aojuifier Teat NEU Study Arm
Mountain Vi«M. CA
Vol.!
Mountain ViaM wad 18 (NV18)
Aquiftar Taat (NEW) study Araa
Mountain Via*, CA
Vol. II
PACES
30
400
124 06/29/87 Anthony lurgaaa
Solder Aaaoc.
Clam Kiatnar
EPA laaion 9
Oaap Soil rnvmtioation 365
Eaat Middlafiled (toad
Mountain Vtaw, CA
20
125 06/30/87 JMM ». Otivar
Phillip FitztMtar
Harding L
Clam Kiatnar
EPA Baflion 9
Intal Soil Soring Data
Mountain Viaw, CA
2CO
126 07/00/87 Niddlaftald'EUia-Uhi
Coapaniaa
127 07/21/87 Gtann Kiatnar
EPA lagion 9
EPA fagion 9
John Maati
Intal
•I Vol. 1*3 I 9 Does 4 Vol. 2-
8 (aviaad Matariala fn Racord
(Vol. 4-8 Avail, at Mt. Viaw
Public Lib. 4 EPA lagion 9.)
Additional Oaap Monitoring
Hal la
2102
07/21/87 Phillip Htzuatar
Harding tataon Aaaoe.
Michaal Rosa
Raythaon
Tranaaittai of final Phaaa III
Subaurfaca Invaatigation
Report
225
07/24/87 John NaatarMn
Intal
Glam Kiatnar
EPA Region 9
Intal Raaponaa to EPA
6/11/87 eoaawtta on Raaadial
Invaatigation
41
<0 08/04/87 John Naa
Intal
Clam Kiatnar
EPA Ragion 9
Additional Oaap Monitoring
Ualla
08/04/87 Jeff Zalikaon
EPA Ragion 9
Oava Oaardorf
Raythaon
Vapor Extraction Work
11/87 Kant KltehingMn
EPA Ragion 9
A*y Ziaphar
EM Ragion 9
Ravian of Analytical Data
-------
KVISION DATE: 05/22/89 . . PACE: 13
m Arw
Noutuin Vf«n. California
oocf OATJ nKn/amuimTiai To/aMamzATiai oesctiprttti/auMgeT PACES
133 00/00/00 Orgwie OtMical AmlyvU 2
-------
i>»0* MO. - i
12/29/88
Niddlefieid-eiila-ttieaan ATM Superfund Sit*
Mountain Vf«f, California
AOMIHISTRATIVf RECORD INMX
ooc. *
OATI
FRON/OKAJIfZATiaN
TO/atfiANIZATION
PACES
10
tt
12
11/14/86
03/02/87
11/01/87
12/04/87
01/04/88
01/00/88
01/27/88
02/00/88
02/04/88
02/08/88
03/03/88
03/10/88
N. Oliver
JMM a. MeClur*
Harding LaMMn
Associate*
Stevo Doorijcvic
Canoni*
Environaantal
Canonic
Harding LaMon
icr •
C.I. Bostic
Fairdiild Corp.
Keith A. Takat*
EPA Region 9
Canonic
61am I. Klatnar
EPA Region 9
David P. Nodflutft
Harding LaMaon
^•nnia L. Curran
Canoni*
C.t. toacte
Pairdiitd
O»ft lagion 9
C.t. loatfe
Fairdiild
Saarieonduetor Corp.
EPA
Caap Or****r A
NcCa*. Inc. ' .
Glam I. Kiatnar
EPA Region 9
C.I. tactic
Feirenild
EPA Region 9
C.I. tactic
Fairdiild
RaytlMon
Clem I. Kfatner
EPA Region 9
Clam I. Klatner
EPA Region 9
Tednical Nam Franeia Uell
TIM Series Teat RI/FS
Siltee Area Uatar Quality Data
On-Site Coneantrations of Metals
in Ground Uatar
Occurrence of Antiacny, Arsenic,
Cadaiue and Lead in PUbticty
Saapled Water Supply Uclls and
Water Siaiply Syataw. Santa
Clara Cowty, CA. RI/FS
(Draft)
Ltrj Aduiniatrativc Record for
ROD
Ltr: ua* the Upper Aquifers (A t,
I) in Nt. View
Report: Rexendea Well 23C*2
Pusping Test Fairdiild Nt. View
Facility
Ltr re: Adainiatrative Record
for the Sit*
Soil Vapor Extraction Study
Ltr: Monitoring Wall Locations
and Screen Intervale, Additional
•gi- Walla North of tayanore
Report: Potential Conduits Study
dietion laundery
37
26
187
228
127
260
-------
Paae MO.
12/29/88
ooc. •
13
14
15
16
17
18
19
20
21
22
23
24
25
26
•2
OATH
03/11/88
03/11/88
03/24/88
04/04/88
04/05/88
04/05/88
04/06/88
04/14/88
04/15/88
04/25/88
04/27/88
05/09/88
05/18/88
05/20/88
Niddlefield-EUIs-UMsssfl Ares Sup
Mountsln View, Californi<
ADMIMISTRATlVf RECORD IMDI
Tupplsssnt He. 1
FRON/ORCAMIZATIOM
Intel. Feirchild t
Intel, Feirchild A
Raytheon
Erie 6. Lappala
Harding LaMeon
Erie 6. Lappala
Harding Lemon
Clem R. Kietner
EPA Region 9
C.R. Bostie
Feirchild
Jess* C. NcClurs
Harding Lawson
Canonie
Oemis L. Curran
Canonie
Ctem R. Kietner
EPA Region 9
Intel
C.R. Bostie
Feirchild
* *
Clem 8. Kistner
EPA Region 9
Otein Ping Kao
CDHS
TO/ORGAHIZATIOM
EPA Region 9
EPA Region 9
'Intel. Feirchild A
Intel. Feirchild A
Raytheon
C.R. Bostie
Fairchild
Clam R. Kistner
EPA Region 9
C.R. Beetle
Feirchild
EPA Region 9
C. Robert Bostie
George Cut leg*
Clem R. Kistner
EPA Region 9
Roger B. James
Regional Uster
Quality Control
Boerd
%£?*"*
Helen McKlnley
EPA Region 9
OeSCRIPTItt/SUBjeCT
Selection of Netele of Concern
on
Ltr: CON Modeling for the RI/FS
Ltr: 3/3/88 Meeting with COM On
Modeling For the RI/FS
Itr: EPA Review of the
•Potential Conduit* Study and
(eradiation Boundary Report",
3/88
Itr: Computer Modeling for the
eite
Utr:
3/88
of Activities for
Water Quality Test Remits
Ltr: Monthly Statue Report 3/88
Ltr: Data Validation
Ltr: Response to Specific RI
Report Coswnts by EPA
Seeiemuel Status Report:
Feirchild 7/1/87 • 12/31/87
Ltr: Response To Companies'
Letter On OroundMoter Modeling
Ltr: State ARAM for the site
PAffiS
18
1
180
-------
r-eae Mo.
12/29/88
ooc. *
27
28
29
30
31
32
33
34
35
• 3
OATI
06/14/88
06/15/88
06/24/88
07/05/88
07/11/88
08/08/88
08/12/88
09/02/88
10/12/88
Niddlefield-Ellis-Uhisman Are* Superfund Sit*
Mountain View, California
ADMINISTRATIVE RECORD IMDCX
FROM/ORGANIZATION
Eric 8. Lappala
Harding Laueon
George A. Gullag*
Dennis L. Curran
Canonie
C.R. Boatie
Fairchild
George R. Gultage
Raythaon
Phil Betel
EPA Region 9
Gtcm R. ristner
EPA Region 9
1C* • Claaant
C. R: Bostie
Fairchild
TO/QMANIZATIOM
Intel, Fairchild ft
Raythaon
Glenn R. Clstner
EPA Region 9
C.R. Bostic
Fairchild
Gtam R. Ktstner
EPA Region 9
Gtam R. Kistner
EPA Region 9
Gaorga Gullaga
Raythaon
Gaorga Gullaga
Raytheon
Caap Oraaaar ft MeJCee
Steven R. Ritchie
Regional Water
OCSOMPTIOM/SUUCCT
Ltr: Requirements for Additional
Information to Adequately Review
Ground-Water Flow and Transport
Modeling Performed by ON
Ltr: Rl Report • 6/15/88
Revision RI/FS
Ltr: Information Needed on COM
Silva Well Model
Ltr: COM Modeling Reports
Ltr: Preliminary Responses to
EPA Comments on FS
Ltr: Approval Of 6/15/88 RI
Report
Ltr: Camp Oreasar and McKee's
Grounduater Modeling
Endangarmmnt Aasaaammnt
Semiannual Status Report:
Feirchild 1/88 • 6/88
36
37
38
39
10/21/88
11/01/88
11/01/88
11/01/88
Quality Control
Beard
Caap Orasaar i Me*
Glenn R. Kistnar
EPA Ragion 9
I
Canonia
:*a EPA
Fairehild, Intel ft
Raythaon
Evaluation of Potential Conduits
in the Local Study Area
Guidance Documents For
Administrative Record
Fact Sheet: EPA Announces
Proposed Plan to Clean Up N-E-W
Suparfund Si tea
Draft Rpt: Feasibility Study,
M-E-W Area, Nt. Via*, CA
PACES
13
215
123
22
10
1100
-------
P99* «0. * •
12/29/88
Niddlof tot •opart for *•!-« Arm, Nf.
Vfow, 6A. trtth Cavmta
-------
Pag* No.
05/25/99
N1ddlaf(eld-CUIs-Uiia*an Suparfund Sit*
Mountain view, California
AMINISTRATIW HOMO INMX
Mo. 2
OATI
OOC. f
AUTHOR
RfCIPIWT
oescti»TioM/SMjtcT
PAGES
02/01/86
02/01/86
02/01/86
OS/01/86
07/07/86
07/21/86
07/28/86
EPA-9
EPA-9
RoMdial Raspanso
Peogra*)
EPA-9
RaMdial Ri
0.00
1.00
2.00
3.00
4.00 " EPA-9
5.00 Nicnael Kant
Research Assoc.
Citizens for a
Better Environment
6.00 Chat Leudmar
Oirector •
Facilities Planning,
tnt'l Ops.. Si Itec
Corp
7.00 Tad Saitft
Executive Director
Silicon Valley
Toxic* Coalition
lobart Starn
EPA CoHJiity
Satationa
Coordinator EPA-9
Ctam Kiatnar
EPA-9
Rotaart Starn
EM Co*B«iity
Ralation*
Coordinator EPA-9
Guidanea Oocuamt* for 1
AdBiniatrativ* Racord
Motional Prioritiaa Liat (NPl) 28
Sit* Raythaon Corp., Mtn. vitw,
CA
National Prioritiaa Liat (HPL) 24
Sit*, Intal Corp., Ntn. Viaw, CA
National Prioritia* Liat (NPl) 10
Sit* fairchitd Canra «
Inatruaant Corp., Ntn. Viaw, CA
IMU92
ContaMination Fowd in Ntn.
Vlaifa 0*ap Aquifar. w/aap.
on Fairehild
ToBJcondigror Intaria Ri
Action Proposal.
lial
Coananta on "Intari* Reaadial
Actiona, Farichild Sa*iconauctor
Corporation, Ntn. Viaw Facility
• Draft Report by Canoni* 6/86
on Fairchild
SOBrfconductor Intaria) Claanup
08/22/86
10/01/86
01/09/88
8.00
8.10
8.90
•agion 9
CDN
Olanm NcKann*
Santa Clara, Soard
of SiBiarvlMr
Ot*t Uuchmr
Slltw
Gtam Klatnar
EPA Rnion 9
ttn Raspona* to 7/21 ft 08/07/86
Ltr. about Fairenild Slurry wall
Soil Stapling ft Tank Inventory
Data Compilation.
Ltr:
Plan
on til* Claan-up
153
-------
Page NO.
05/25/89
DATE
OOC. f
MloWefloloVEUfa-VMaaan Superfund Sit*
Mountain View, California
ADMINISTRATIVE RECORD INDEX
tupplaaant No. 2
AUTHOR
RECIPIENT
DESCRIPTION/SUBJECT
PAGES
•02/04/88 9.00 C. Retort loatic
06/01/88 10.00 Lorsnce 0. Wilson
Santa Clara Valley
Water Oiatrict
06/15/88 11.00 Clem Kistner
RPN
EPA-9
06/22/88 12.00 Roger • Joan
Executive Officer
CRMC8-SF
Glorm t. Kistner
CM Region 9
Clam R. Kistner
EM Region 9
George Cullage
Proj. Coordinator
Ratftaon Co.
Philip label
EPV9
Interis) Decision Procasa
Potential Conduits fvaluation
Rpt Mitfi cower latter
Ltr: Closure of Fransia * Silve
Uella
General Coajaenta on Draft FS for
NEW Study Area, M/TL to George
Gullage 6/15/88
on the MEW Feaaibility
Study by Canonio 5/3/88
06/24/88
06/28/88
09/00/88
13.00
Glenn Kfstner
RPN
14.00 NEC Electronics.
Inc.
15.00 Geraghty t Miller
George Gullage
Pro/. Coordinator,
MEW Study Area,
Rayttieon Coapeny
EPA Ccaaawtta On The MEW 10
Feasibility Study W/TL to George
Gullage 7/24/88
Technieai Review Coaaants 21
Raaadial Investigation Report
Rt/PS NEW Area, Mtn. View CA
M/LTR to Glenn Kistner 6/28/88.
M/cherts A
Intel RI/EA/FS Vol. 1-4 with
letter
2000
09/14/88 16.00 George A. Gullage
Raythecn
09/15/88 17.00 lie* Robison
l«f. I • Toxle
.Sutetancea Control
Olvieon
CAOONS
10/00/88 18.00 Canonle
10/13/88 19.00 George A. Gullage
Glam Kistner
EM teflon 9
Glenn Cistner
Ltr: CoaBsnta on Final Draft
Nark Harris
City of Nt. View
CAOONS Cnaaann on NEW Draft FS
Report 8/16/88 Revision
Rpt: Saapling Man Addandua No.
2 walker Drive Investigation
Rf/FS
Ltr: A auaawy of MTI8 •§• and
•Veep* Aquifer Monitoring
Activities with a Distribution
List
-------
Pag* NO.
05/33/89
OAte
ooc. *
Nlddlefleld-Ellta-uMaaan Superfund SfM
Mountain View. California
AMMISTUTIVI RECORD INDEX
SuppieMnt Me. 2
AUTHOR
RECIPIENT
OCSOUPTlOH/SUMfCT
PACES
10/13/88
10/19/88
10/21/88
10/23/88
10/2S/88
20.00 Clem KUtner
CM legion 9
21.00
21.10
Steve Nor**
CRMCI
CBN
22.00 Terrenee J. NcManua
Intel
23.00 Bryan N. Rector
Gaorg* A. Guilf
Raytheon
Clem Klatner
EM Region 9
Philip Sobel
EPA Region 9
Clem Kfctner
EPA Region 9
Cower Ltr of Seep*ing Plan
AoMnBLaW No* 2 tfftti •
Oistribucion list
Itr: Draft «, 10/07/88 Reviaion
Evaluation of Potential Conduit*
in the Local Stuay Area, MEW
(Update of 5/9/88 Oocuaent).
Itr: Roqueat to CaMent on
RI/EA/FS A Sign Separate ROD
Intel Nt. Vfew Ground Uater Data
laa* Rpt. Froai 10/86 • 7/88
attached with Lab Analytical
Rpta, Cover letter, Airbill,
Tranaarittal Letter
850
11/00/88
11/10/88
11/21/88
11/23/88
11/25/88
12/01/88
24.00 EPA
25.00 Clam R. Kfatner
EPA Region 9
26.00 C. Robert 8o*tic
Schluaborger
27.00 Phil tobet
EPA Region 9
28.00 Clem Klatner
EPA legion 9
29.00 Ceorge Cullage
Public
Ceorge Gullage
Raytheon
Philip Babel
EPA Region 9
George Culleg*
12/02/88
30.00 Clam R. Kfatner
EPA legion 9
Clem Staber
CA Off fee of
Pleming 4 tee«arcn
Qlem Kfatner
EPA Region 9
Ceorge Culleg*
Feet StMet
Ltr: Approval of Sampling Plan
Addandua Mo. 2 Walker Drive
Inveatigation Rf/FS But Mot of
Objective of the Plan
Ltr: Intel'* RI/EA/FS for Lot
& Concern about Separate ROD
Ltr: Approval of Reviled FS
under S Caveat*
Ltr: Cover Ltr of FS for
Itr: Confirmation of the
Saeplfng Plan Addandu* Mo. 2
Walker Oriv* Inveatigation,
RI/FS, with a Ofatributfon Li*t
Ltr: Roua* of Crounduater
-------
Pag* Ho.
05/25/89
OATI
MC. •
mddl*fl*ld-Cllfs-Uii*BBn Sunerfund sit*
Mountain vie*. California
i
No. 2
RECIPIENT
PACES
12/09/88 31.00 Cordon C. Atkinson
Coolcy CodMsrd
CMtro Huddleson ft
ran*
David He*
CM Region 9
ttr: Intel's If/IA/rs Lot IS *
Separata MO
12/14/88
12/14/88
12/14/88
12/21/88
01/04/89
01/04/89
01/09/89
01/10/89
01/17/89
01/17/89
32.00
33.00
34.00
35.00
36.00
37.00
38.00
40.00
41.00
42.00
Susan Nisbet
Crangla ft Assn.
Laura T. Tarquinio
League of Uoaan
Voters
Nlchele I. Corash.
Morrison ft Foerstar
•«
Gordon P. Snoit
Th* Resources Agency
of CA
George A. Cull age
Raytheon
Margaret R. Oollbeua
Folgor ft Levin
George A. Gull age
Raytheon
Phil label
EPA Region 9
PHI I label
EPA Region 9
Clem Kistner
EPA Region 9
A*y Zispfer
EPA Region 9
Clem Ktstner
EPA Region 9
Clem I. Kistner
EPA Region 9
Clem Kistner
EPA Region 9
Clem R. Ktstner
EPA Region 9
TfM*CgWe) •)• MCMiVaUS
Intel
• ^M*4n^MMB
•Bytneon
CoBBunity Meeting
Ltr: CUBBSIU on the Proposed
Cleanup Plan
Ltr: Request Extension of
CoBBant Period on Draft FS
Water Elevation Rot.
Ltr: State has no cosBants on
SutaBittal of Technical Report
Extracted Grounduater Use
Ltr: Lltronix Meeds More Tine
Review Draft FS
Ltr: Propose Inter {• ReaBdial
Actions of OW-3 Cluster and
Packing of Silva Wall
Ltr: CoBBsnts on RI/FS/EA for
Intel Lot *3
Ltr: Authorization to work on
at th* OW-3 Well Cluster ft
FS
on
to
RA
81
01/18/89 43.00 Sanoy Olliga* Clam Ktatnar
ABM Research Canter EPA Region 9
01/20/89 44.00 David C. Keahn Clem Clstner
Air Products EPA Region 9
and Treatment of
CroundMter.
Ltr: On Behalf of NASA-
n FS
to
Ltr: Cnaaancs on Draft FS and
Propose Selection of Raieoy for
th* Sit*
-------
NO*
05/25/89
DAT!
01/20/89
01/20/89
01/23/89
01/23/89
01/23/89
01/23/89
01/23/89
01/23/89
01/23/89
01/23/89
01/24/89
01/24/89
DOC.
45.00
44.00
47.00
48.00
49.00
50.00
51.00
52.00
53.00
54.00
55.00
54.00
Niddlefieid-€llls*VM*ean Staierfund Sit*
Nouttaln VfoM, California
I
•*. 2
AUTHOR
RECIPIENT
Stanaly T. Meyers
SI I tec
Ware 4 Freiederich
Thoaas E. Hookane
Crosby, Heofey,
Roach 4 Nay
Steven R. Ritchie
CCUOCS-SF
Retort C. Ttioapeon
Grahoa 4- Jean
Jonathan S. Lao
Heller, Ehraan,
White 4 NeAuliffe
Carie Goodasn
NcKfmey
NcCutchen, Doyle,
Brown 4 Enersen
Robert S. Roaborouoh
Pilltbury, Madison 4
Sutro
Bert 0. Dome
Tracer
Louie* T. LOM
II S Dept. of Navy
Santa Clara Valley
8lem Kistner
EPA Region 9
atom Kietner
EPA Ration 9
Gtam Kiatnar
EPA Ration 9
Glam Kistner
EPA Ration 9
Glam Kistner
EPA Ret Ion 9
Glenn Kiatnar
EPA Ration 9
Gtem Klstnar
EPA legion 9
Glenn Klstnar
EPA Ration 9
Glam Kistner
EPA Ration 9
Glam Kistner
EPA Reflon 9
Glam Kistner
EPA Ration 9
Ltr: Caeaint on 81 (06/88) 4
Draft FS (11/88) and Propose
Cleanup Reaedy for the Sit*
Ltrj Coaaants of Renault 4
Handlay Group on Draft FS
Ltr: Coaaant on FS of Cleanup
Alternative on Behalf of
Sobratoto
Ltr: Coaaant on Proposed Cleanup
Plan
Ltr: Coaaants of Tri-Oata on
Draft FS
Ltr: Coaaants of NEC Electronics
on Draft FS Attached Mith
Technical Review Coaaants
* Ltr: Request RI/FS/EA (10/23/88)
to be Included in A.R.
Coaaants of Spectra-Physics on
Draft FS
Ltr: Coeaent on Draft FS And
Object Any Responsibility to
Pollute th* Sit*
C Meant! on Draft FS Attached
Mith Cover Ltr.
Ltr: Coaaant on Proposed Plan
Attached Mith Rocoeaandad
Vatar OlatHet
V*r«ar
Tracer X-Ray Inc.
Position of Santa Clara Vallay
Water District on IBM Raaadial
Action Plan
Rots Investigation of Soil
Contaainatlon at 345 Nlddlefield
Rd. Attached Mith Letter to
Glam Kistner.
PACES
17
13
82
-------
Pag* Mo.
05/25/89
Ntddlefield-illle-Wbiaaan Suparfund sit*
Nountain View, California
MNINISTMTIW RfOORD II
•a. 2
OAT!
OOC. f
AUTHOR
RECIPIENT
PAGES
01/30/89
01/31/89
02/07/89
02/22/89
03/02/89
03/06/89
03/15/89
03/21/89
04/12/89
57.00
58.00
59.00
60.00
61.00
62.00
63.00
64.00
65.00
Qlom I. Kfatner
CM legion 9
George A. Gut tag*
Nark RarHa
of Nt. vi*M
Phil total
EPA legion 9
Philip label
atief-laaadial IP.
Superfund Prog.
EPA-9
George Gut tag*
Proj. Coordinator
laytheon Co.
EPA-9
6«org* Gut tag*
Proi. Coordinator
laythaon Co.
Gaorg* Gut tag*
Proj. Coordinator
layttwon Co.
Canoni*
fitam Klatnar
EPA lagion 9
Gaorg* Gut tag*
•aythoon
Tarry NeManua
NgT'Corearat*
Environaantat
Affairs, Intat Carp.
Oiatribution.
61am Kiatnar
6PA-9
Oiatribution
Gut lag*
Proj. Coordinator
•artfcoon Co.
Ltrj Poraiaafon to Soal tha city
Park and lacraation wall
GroundMtar Laval Nonitori«ig<>C
Aquifar and Uatar Quality laault
• Sltva Watt ctuatar Attaehad
Covar Latter
Itr: Hotiea of Sealing Wells and
Liability for the Cost
Intat
a on NCV FS.
Public CIMHHIH on Nell Area FS
ttport M/TL to Glam Kistnar
3/2/89
If: PhiIp
letter of 2/7/89
Environaantal Hewat EPA Plans to
seat no Near-by Walla, (2)
I'
Public Ccwinca on the MEW Area
FS leport M/TL to Glem Kistner
3/21/89.
lot: Walker Drive Investigation
•I/PS NEW Study Are* Ntn. View,
CA
19
-------
06/12/W
Nloo'lefteld*EUt«-uhtaaan Suparfund sit*
Mountain Vie*. California
ADNHISTMTIVC KGOR0 IIBCX
SUppaUaant MO. S
OAT!
DOC.*
AUTHOR
OeSdtPTIOH/SUBJECT
PAGES
04/Z5/89 1 B«y ArM Air Quality intar«t«d p*rti<
District
Toxic Air Peiluum Source SO
Mnnaant Manual for
California Air Pollution
Control OiatHcta ("CAPCOA
ouioanca*) Auguat 19«7.
Uorkahop Notica: Propoaad 3
••aulacion 8, tula 4o. Air
Stripping ft Soil Vapor
Extraction Operation.
Total
------- |