United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R09-91 /057
June 1991
&EPA Superfund
Record of Decision
CIS Printex, CA
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50272-101
REPORT DOCUMENTA nON 11. REPORT NO. I ~ 3. Recipient's Acceealon No.
PAGE EPA/ROD/R09-91/057
4. TIlle 8IId Sub1ItIe .5. Report Date
SUPERFUND RECORD OF DECISION 06/28/91
CTS Printex, CA
6.
First Remedial Action - Final
7. Author(a) 8. l'erfonning Organization Rept. No'
8. I'erfonnlng Orgalnlz81lon Name 8IId Acldreaa 10. ProjectlTuklWork UnIt No.
11. Contract(C) or Gr8nt(G) No.
(C)
(Co)
1~ Sponsoring Organiz8llon Name 8IId Ac1dre88 13. Type of Report & Period Covered
U.S. Environmental Protection Agency
401 M Street., S.W. 800/000
Washington, D.C. 20460 14.
15. Supplementary No1e8
16. Ab81ract (Umlt: 200 _rda)
The CTS Printex site is an inactive printed circuit board manufacturing facility iri
Mountain View, Santa Clara County, California. Land surrounding the site is used' for
industrial, commercial, residential, and agricultural purposes. The site overlies
two major water-yielding zones, a shallow and deep aquifer, which are suspected to be
hydraulically continuous. Historical ground water use in the area surrounding the
site includes private water-supply wells for homes and agriculture prior to the
construction of public water and sewer connections in 1984. Site features include a
flammable materials storage shed area, an industrial wastewater sump used to
neutralize and discharge waste ~o the publicly owned treatment works (POTW), a "wet
floor" building used for both wet and dry manufacturing processes, a materials and
waste storage warehouse, and various office buildings. From 1981 to 1985, the CTS
Printex site manufactured printed circuit boards at its onsite facilities. Site
investigations by CTS Printex in 1985 established that the "wet floor" building and
the wastewater sump areas were the sources of onsite soil and ground water
contamination, and that the release of contaminants was attributed to deterioration
of the concrete bases. In 1986, the State certified closure of the former CTS
(See Attached Page)
17. Document An8Jyaia L Descriptors
Record of 'Decision - CTS Printex, CA
First Remedial Action - Final
Contaminated Medium: gw
Key Contaminants: VOCs (benzene, PCE, TCE, toluene)
b. Identlfier8lOpen-EndecI Terms
c. COSA 11 FieIcIIGroup
18. Availability Statement 18. Security Claaa (Thia Report) 21. No. of Pages
None 68
20. Security Claaa (This Page) n PrIce
Nonp
2n (4-77)
(See ANSI-Z38.18)
See InstnJclions on Reverse
(Formerty NTI~)
Deper1ment of Commerce .
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EPA/ROD/R09-91/057
CTS Printex, CA
First Remedial Action - Final
Abstract (Continued)
facility. In 1987, the State required CTS to implement the following interim remedial
actions for soil and ground water: destroying and removing contaminated onsite
structures, removing residual metals sludge and process debris from the site,
hydroblasting interior areas of structures exposed to contaminants, excavating the sump
and contaminated soil, and installing and operating a ground water extraction system.
This Record of Decision (ROD) addresses contaminated onsite ground water. The primary
contaminants of concern affecting the ground water are VOCs including benzene, PCE, TCE,
and toluene. .
The selected remedial action for this site includes continuing the current ground water
extraction system, including discharging the untreated water to the sanitary sewer for
offsite treatment at the POTW; and ground water monitoring. Passive air stripping is
created by passing water through the sewer collection system and through the sewage
treatment plant. The estimated present worth cost for this remedial action is $786,000,
which includes an estimated O&M cost of $104,700 for 15 years.
PERFORMANCE STANDARDS OR GOALS: Ground water cleanup goals are based on the more
stringent of Federal MCLs or non-zero MCLGs, or State MCLs. Chemical-specific goals
include benzene 1 ug/l (State), PCE 5 ug/l (MCL), TCE 5 ug/l (MCL), and toluene 100 ug/l
(State). Action-specific goals include compliance with the City of Mountain View's
discharge requirement for the sanitary sewer, which is total organics equal to lug/l at
the point of discharge.
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RECORD OF DECISION
CTS PRINTEX CORPORATION SUPERFUND SITE
MOUNTAIN VIEW, CALIFORNIA
JUNE 28, 1991
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION 9
1
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PART
I
I
I
I
I
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II
II
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II
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CONTENTS
SECTION
Declaration
1..0
site Name and Location
2.0
statement of Basis and Purpose
3.0
Assessment of the site
4.0
Description of the Remedy
Declaration
5.0
1.0
DecisioD'summary
site Description
1..1
site Name and Location
1.2
Regional Topography
Adjacent Land Use
1.3
1..4
Historical Land Use
. 1..5
Hydrogeology
Surface water
1..6
1.7
Water Use
1..8
Surface and Subsurface structures
2.0
site History and Enforcement Activities
2.1
History of Site Activities
History of site Investigations
2.2
2.3
History of Enforcement Actions
Community Relations
3.0
4.0
Scope and Role of the Response Action
Scope of the Response Action
4.1
, 4.2
Role of the Response Action
Summary of site Characteristics
5.0
5.1
Sources of Contamination
2
PAGE
6
6
6
6
6
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8
8
8
8
8
8
11
11
11
13
15
15
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PART
II
II
II
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III
IV
SECTION
5.2
5.2.1
5.2.2
6.0
6.1
6.2
6.3
6.4
6.5
7.0
7.1
7.2
7.3
7.4
8.0
9.0
10.0
.11.0
CONTENTS cont'4
Description of contamination
soil Investigations
Groundwater Investigations
Summary of Site: Risks
-.--.
Toxici ty Assessment --
Risk Characterization
PAGE
21
21
21
26
26
29
Presence of " Sensitive Human Populations. 33
Presence of Sensitive Ecological Systems
Conclusion
Applicable or Relevant and Appropriate
Requirements (ARARs)
Types of ARARs
Chemical Specific ARARs
Action Specific ARARs
Location-specific ARARs
Description of Alternatives
Comparative Analysis of Alternatives
Statutory Determinations
Documentation of Significant Changes
Responsiveness summary
Administrative Record
3
36
36
36
37
38
38
40
40
41
45
45
46
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TABLE
1
2
--...-
3
4
5
6
7
TABLES
T:ITLE
PAGE
.24
Soil contaminants at the CTS site
Groundwater Contaminants at the CTS site
~-ToXlcoloqical Properties for :Indicator
Chemicals
25
31
carcinogenic and Noncarcinogenic Risks
for Contaminants in Residential Air
32
carcinogenic and Noncarcinogenic Risks
from Soil contamination
34
Carcinogenic and Noncarcinogenic Risks from
Ingestion of Ground Water from Shallow Aquifer
Chemical Specific ARARs
35
39
4
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PIGtJRE
1.
2
.3
4
5
6
7 .
8
FIGURES
TITLE
.:~ CTS-printex Site Location in Bay Area
CTS-printex site Location in Mountain View
Hydrogeologic Profile
. -".- -.---
..---.-.-.
Surface and Subsurface structures
Location and Depth of Excavation
Location of Extraction Wells
Plume Boundaries in A-- Zone
Plume Boundaries in B ~. Zone
5
PAGE
9
1.Q
1.2
1.4
18
19
22
23
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I.
DECLARATION
1.0
SITE DKB AND LOCATIO.
.CTS Printex corporation
1911, 1921, and 1931 Plymouth street
and 1950 Colony Street .
Mountain View, California 94043
2.0
STATEMENT AND PURPOSE
This Record of. Decision ("ROD") presents the selected remedial
action for the CTS printex Superfund site in Mountain View,. .
California. This document was developed in accordance with the.
Comprehensive Environmental Response, Compensation, and Liability
Act of 1980 (CERCLA) as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA), 42 U.S.C. Section 9601et
sea.. and in accordance with the National Oil and Hazardous Sub-
stances Pollution Contingency Plan, 40 C.F.R. Section 300 et
sea.. (IINCP"). The attached administrative record index
(Attachment A) identifies the documents upon which the selection
of the remedial action is based.
3.0
ASSESSMENT OF THE SITE
Actual or threatened release of hazardous substances from this
site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial en-
dangerment to public health, welfare, or the environment.
4.0
DESCRIPTION OF THE REMEDY.
The selected remedy for the CTS Printex site is groundwater ex-
traction by seven extraction wells and discharging under permit
to City of Mountain View wastewater treatment plant.
This remedial action addresses the principal risk remaining at
the CTS printex site by removing contaminants from ground water,
thereby significantly reducing the toxicity, mobility or volume
of hazardous substances in ground water. This response action
will greatly reduce the possibility of contamination of existing
potable water supplies and potential future water supplies.
5.0
DECLARATION
The selected remedy is protective of human health and the en-
vironment,.complies with federal and State requirements that are
legally applicable or relevant and appropriate to the remedial
action, and is cost-effective. This remedy utilizes permanent
solutions and alternative treatment (or resource recovery) tech-
6
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,.
nologies to the maximum extent practicable and satisfies the
statutory preference for remedies that employ treatment that
reduces toxicity, mobility, or volume as a principal element.
Because of the considerable time required to achieve cleanup
levels for the contaminants in the aquifer, a five-year review,
pursuant to CERCLA section 121, 42 U.S.C. section 9621, will be
conducted at least once every five years after initiation of the
remedial action to ensure that the remedy continues to provide
H -- adequate protection of human health, and the environment.
~~IW.l1nt~
, Daniel W. McGovern '
Regidnal Administrator,
(,.28.Q I
- Date
EPA Region, IX
7
,..
'.
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:II.
RECORD OF DECISION
DECISION SUMMARY
This Decision Summary provides an overview of the problems pased
by the CTS printex Superfund s~te (the ~Site" or the "facility"),
the alternatives considered for remediating the Site, and the.
analysis of the remedial alternatives. This Decision Summary ex-
plains the rationale for the remedy selection and how the
selected remedy satisfies the.statutory requirements.
1.0
SITE DESCRIPTION
SITE NAKE AND LOCATION.
1.1
.' , . ,
- CTS printex Corporation (CTS) manufactured printed circuit boards
at its former facility in Mountain View from 1970 to 1985. The
, facility was located on PlYmouth and Colony streets east of
Sierra vista Avenue at 1904, 1940, and 1950 colony street and at
1905, 1911, 1921, and 1931 PlYmouth street (Figure 1 and 2). CTS
leased this property from the owner, ADNCorporation.
1.2 .REGIONAL TOPOGRAPHY
The Site is located on the northwest corner of the Santa Clara
valley between the south end. of the San Francisco Bay and the
Santa Cruz Mountains in the County of Santa Clara. The site is
located 2.5 miles south of San Francisco Bay. The terrain at the
site is relatively flat except for sUrface drainage.
1.3
ADJACENT LAND tJSE
The land surrounding the Site is zoned for light industrial/
manufacturing, commercial, residential, and agricultural use. In
general, the industrial land use is south and north-northwest of
the facility, the commercial land use is north extending across
from u.s. Highway 101, and the residential land use is west of
the facility. In recent years, the surrounding area, especially
north of u.s. Highway 101, has been progressively converted from
a residential and agricultural area to a light industrial commer-
cial area~ Approximately 20 acres of land, north of the
facility, is used for a commercial farming operation.
1.4
HISTORICAL' LAND USB
According to Arthur D.' Nearon of the ADN Corporation, prior to
the construction of the buildings at 1904, 1940, and 1950 Colony
Stree:t.and at 1905, 1911, 1921, and 1931 PlYmouth Street, the
site consisted of an open field. The existing'buildings are the
original structures constructed on the site in 1970. The only
industrial activity known to occur on this property was the
manufacturing of circuit boards.
.,
8
,..
."
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Site Location Map
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Historical aerial photographs for adjacent Superfund sites show
that historical land use near the Site was agricultural, dating
back to 1937 and possibly further. The surrounding area was'
developed as an industrial area during the period from 1961 to
1973. Companies historically located in. the vicinity of the CTS
site were involved in a wide range of manufacturing activiti~s, ,
including the manufacturing of amusement park equipment, laser
devices, printed circuit boards, electrical test equipment, and
semiconductors.
1.5
HYDROGEOLOGY
SUbsurface conditions at the site are typical of the Santa Clara
Valley. The two major water-yielding zones beneath the site con-
sist of a shallow aquifer (75 feet thick) and a deep aquifer
separated by an aquitard which is. approximately 50 feet thick
(Figure 3). Three shallow aquifer zones have been identified
beneath the site. These zones are designated as the A,B, and in-
termediateaquifer zones. The A zone has its upper boundary at
approximately 10 feet below ground surface (BGS), and lower
..-.. boundary at approximately 20 feet BGS. The B zone lies between
approximately 30 and 40 feet BGS. It is suspected that the A and
B zones are hydraulically continuous. The intermediate zone lies
between approximately 60 and 75 feet BGS. . The deep aqui~er oc-
curs at approximately 100 to 150 feetBGS. Shallow groundwater
flow in the A and B zone, beneath the site, is generally to the
north. This flow regime is consistent with the northerly
regional flow towards the San Francisco Bay.
1.6
StnU'ACE WATER
I .
I
The surface water bodies in close proximity to the Site are the
southern San Francisco Bay (South Bay) and Permanente Creek. The
South Bay is relatively shallow, averaging less than six feet
deep. The headwaters of Permanente Creek are approximately 12
miles south of the facility in the Santa Cruz mountain range.
Permanente Creek is a perennial stream that travels a distance of
3.5 miles from the site before reaching the Mountain View Slough
which drains into the South Bay. The creek travels through a
concrete lined box culvert until approximately 300 feet
downstream of the site where it then becomes an earthen lined
ditch.
1.7
WATER USB
Historical groundwater'use in the area surrounding the site in-
cludes private water-supply wells for homes and agriculture prior
to the construction of public water connections and sewer connec-
tions in 1984. A review of data on active, abandoned and closed
wells within the study area identified 72 wells in the area
bounded by permanente Creek, Rengstorff Avenue, Colony Stree~,
and Charleston Road. Of the 72 wells, 48 were registered wells
and 24 were unregistered wells. Of the 48 wells, 8 of the
11
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wells are active and only one well was considered to be a poten-
tial conduit. Of the 24 unregistered wells, documentation was
obtained for only one well. . .
Existing or potential beneficial uses of the South Bay and/or
Permanente creek are wildlife and estuarine habitat; fish spawn-
ing and miqration; shellfish harvesting; ocean, commercial, sport
fishing; and 'industrial service supply.
1.8
SUJUI'ACB ANI) St1BSURl'ACB8~tJCTtJRES
Described in this 'section and indicated on Fiqure, 4- are the sur-
face and subsurface structures at the site. Surface and subsur-
face structures at the Site,are as follows:
o
Flammable, Materials Storage' Area: This storage area con...,' "
sisted of a small shed constructed of metal on a concrete
base. No drains or berms were associated with this struc-
ture. Materials stored in this structure included lubricat-
ing oil, hydraulic oil, fluxes, and isopropanol.
1940 and 1950 Colony Street: This building housed the prin-
tex administrative offices as well as sales, engineering,
accounting, and purchasing offices. In addition, some
manufacturing operations occurred in this building.
o
o
1904 Colony street: This building was used for data
processing and laminate storage. No hazardous ,materials are
believed to have been stored in this building or on the sur-
rounding grounds. The floors in this building were concrete
'with no berms or trenches.
o
1911 Plymouth Street: This building was referred to as
"wet floor building," and was the main site of both wet
dry manufacturing processes employed by CTS. Chemicals
in this building included phosphoric acid, hydrofluoric
acid, methyl ethyl ketone, tin, and lead.
1921/~931 Plymouth street: This building was used for
manufacturing processes which~included etching and solder
leveling. This building was predominantly a dry process
area and no chemicals were stored at this location.
the
and
used
o
o
1905 Plymouth Street: This warehouse was the main material
and waste storage area for CTS. 'All materials used at the
CTS facility were stored in this warehouse. The floor of
the warehouse was concrete. The tilt-up concrete walls were
sealed to the floor with mastic, and a small trench existed
across the doorway.
o
Industrial Wastewater Sump: This neutralization sump col-
lected and neutralized all wastewater from the CTS facility
,13 '
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2.0
2.1
before discharging to the sanitary sewer. The sump was in- ,-
stalled in 1970 and was constructed of steel~reinforced con-
crete. The sump consisted of three discrete chambers with a
total capacity of about 1,500 gallons-.
S!'1'B m:STORY AND ENFORCEMENT ACTIVITIES
HISTORY OP SITE ACTIVITIES
Printex was incorporated in 1966 and operated a printed-circuit -
board manufacturing facility at their former facility in Mountain
View from 1970 to 1981. - In 1981, printex was acquired by CTS
Corporation and was renamed CTS Printex, Inc.. CTS printex .
manufactured printed circuit boards at its manufacturing facility
located at 1904, 1940, and 1950 Colony street and at 1905, 1911,
and 1931 Plymouth street from 1981 to 1985. Printed circuit -
board manufacturing processes which generated waste-were --
primarily located within the buildings at 1911, 192i', and 1931
Plymouth street (Fi~e 4). -
2.2
HISTORY OP SITE INVESTIGATIONS
Site investigations were initiated by CTS in January 1985 prior
to closing the facility. These investigations detected con-
tamination, primarily metals and VOCs,in soil and ground water.
In 1987, the Regional Water Quality Control Board (RWQCB) ordered
. CTS printex to conduct a remedial investigation at the facility.
Results from the remedial investigation are discussed in Section
5.0. FOllowing investigations initiated at the CTS site, CTS
implemented the interim actions described in Section 4.1.
2.3
HISTORY OP ENFORCEKEN'l' ACTIONS
In December, 1984, CTS printex conducted a meeting with represen-
tatives from the Department of Health Services (DHS), the RWQCB,'
and the Mountain View Fire Department (MVFD) to plan their volun-
'tary site assessment in anticipation of closing the facility.
Enforcement actions to date are as follows:
o
o
o
o
o
October 1986: DHS Certified Closure of former CTS Facility
March 1987: RWQCB Issued Clean-up Abatement Order No. 87-05
Apr~l 1989: RWQCB Issued Clean-up Abatement Order No. 89-63
February 1990:
List
EPA Placed CTS on the National Priorities
November 1990: RWQCB Issued Clean-up Abatement Order No.
90-14
15
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-
3.0
COMHtJ'NI'rY RELATZONS
The RWQCB has maintained an aggressive Community Relations
program for the'Site. The RWQCB published a notice in the March
1991 issue of "The View," the city of Mountain View community
newspaper, announcing.the proposed final Remedial Action Plan
(RAP) and announcing the opportunity for public comment at RWQCB
Hearing of March 20, 1991 and at the community meeting on March
21 1991. A presentation of the final cleanup plan was made at
'---ue -RWQCB ~earing but not at the community meeting since no local
residents attended the meeting. The comment period for the
proposed cleanup plan was from March 20, 1991 to April. 19, 1991.
No comments were received from the community regarding the
proposed plan for the CTS site.
Fact Sheets were. mailed to .interested residents, local government
officials~ and media representatives. Fact Sheet ,1, mailed in
October, 1989, summarized the pollution problem, t~e results of
investigations to date, and the interim remedial actions. Fact
Sheet 2, mailed in March, 1991, described the cleanup altern~- .
tives evaluated, explained the proposed final RAP, annou~ced op-
portunities for public comment at the Board Hearing of March 20,
1991 and the Public Meeting of March 21, 1991 in Mountain View'
and described the availability of further information at the in-
formation repository at the City of Mountain.View Public Library.
4.0
SCOPE AND ROLE OP THE RESPONSE ACTION
4.1
SCOPE OF THE RESPONSE ACTION
The remedy selected,for the site addresses significant risks to
human health and the environment which were not mitigated by pre-
vious interim remedial actions. Interim remedial actions at the
CTSsite included: 1) the destruction and removal of contaminated
structures; 2) removal of residual metals sludges and process
debris from the Site; 3) hydroblasting interior areas of struc-
tures exposed to contaminants; 4) excavation of neutralization
sump and approximately 255 cubic yards of soil which .was
transported to 'a Class I hazardous waste landfill; 5) installa-
tion and operation of a groundwater extraction system which dis-
charges to the sanitary sewer. The remedy selected for the Site
requires that the existing groundwater extraction system.con~inue
operating until cleanup levels are achieved in the aff~cted
aquifer. '.
In accordance with a closure plan approved by DHS, CTS decon-
taminated the building at 1911 Plymouth ("wet flopr building")
and excavated the neutralization sump and floor area. The wet
floor building was decontaminated by removing contaminated. build-
ing materials and hydroblasting the interior. of the building.
Residual sludges and debris were removed from the building. The
cement floor and 255 cubic yards of underlying soil was excavated
from the wet floor building and backfilled with pea gravel. Ex-
cavation of the neutralization sump involved removal of ap-
16
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proximately 40 cubic yards of material, including concrete and
soil. All drain lines associated with the sump were exposed and
inspected at this time. The locations and depth of excavation
are indicated in Figure 5. The excavated areas were backfilled
with pea gravel and resurfaced. Prior to backfilling excavated'
areas, DDS collected and analyzed samples from the excavated
areas to ensure total organics in soils did not exceed 1 part per
million (ppm). According to the Quarterly Monitoring Report
dated April 15, 1991, the highest total concentration of VOCs
discharged to the sanitary sewer is 803 ug/L. DHS certified of~
ficial closure of the former CTS printex facility in October
1986. '
In November, 1986, crS submitted an "Interim Remedial Plan" to
the RWQCB proposing an immediate response action for mitigating
downgradient, off-site migratiQn of ground water containing
volatile organic compounds (VOCs). The interim remedial response
actidn included groundwater extraction and discharge under permit
to the City of Mountain View sanitary sewer system. In July,
1987, CTS started extracting ground water from two shallow zone
extraction wells (ES1W and ES2W) and two intermediate zone ex-
traction wells (ED1W and ED2W). In December, 1988, CTS added two
additional shallow zone extraction wells (ES3W and ES4W) and one
intermediate zone extraction well (ED3W) to their extraction sys-
tem. The location of these extraction wells are indicated on
Figure 6. The extraction wells are currently pumping ap-
proximately 45 gallons per minute (gpm) and are discharging under
permit to the sanitary sewer.
The remedy selected for the Site is to continue operation of the
seven extraction wells until the cleanup levels described in Sec-
tion 7.2 are achieved. The capture zone created by the existing
extraction wells is effectively containing and remediating the
groundwater plume emanating from the CTS site. Extracted ground
water will continue to be discharged under permit to the City of
Mountain View wastewater treatment plant. The city of Mountain
, View permits no more than, 1 ppm of total organics in an effluent
stream at any point of discharge to the sanitary sewer.
4.2
ROLE OF THE RESPONSE ACTION
The selected remedy addresses the primary risks posed by the con-
tamination in ground water in the the Upper Aquifer Zone. These
primary risks are: further lateral migration of the plume emanat-
ing from the Site; potential vertical migration of contaminated
ground water into the Deep Aquifer Zone; iri1:Jestion and inhalation
of contaminants in the ground water from the Upper Aquifer Zone;
and inhalation of chemicals volatilized from contaminated ground
water. The interim action addressed the principal threat by.ex~
ca~at:ng contaminated material from the site and transporting the
material to a Class I hazardous waste landfill.
17
1$'
-------
Excavation Boundary
1 at S' Mow grade
excavation wal rs~~
1 at S* below grade
1 at r below grade
excavation wan
1 at »' below grade
excavation wai
1 at S' below grade
xexeavatton wal
1 at «• b«low grado
•wavatlon floor 7,
t at s' bolow gratfo
•xaavatlon wal
1 at IV Mow grado fi>
•mavaUon floor
•1.2
•10
1 at •• b«tow grado
auavatlon floor
1 at 5* bolow grado
•9 ««c«»atk>n wa>
LEGEND
• Sou Sampto (M«tal« Analyst*)
lat
•xoavatloa waH
I at 3' bolow grado
•xeavalton *••
Excavation
..Boundary
SR
.
SF
SB
I at to- b«low grade
x^wcavatlon bottom
t at 3' bolow grado
mcavatlon wall
I at 3' bolow grado
excavation waH
JP
20
30
SCALE
foot
Source Excavation Sampling Locations
FIGURE SI LOCATION AND DEPTH OF EXCAVATION
ocg
occc
go
CL
-------
- --------.-
--I
....1«
-
OG
a: a:
00
o
a..
-------
,5.0
The objective of the selected remedy is to remove and permanently
destroy the contaminants from ground water or significantly
reduce the toxicity, mobility or volume of hazardous substances
in the ground water. This response action will greatly reduce'
the possibility of contamination of current and potential water
su~plies. ' '
SUKMARY OF SITE CHARACTERISTICS
5.1
SOURCES, OF CONTAMINATION
Areas that were considered as potential contaminant sources at
the facility were the following:
o
The wet-floor located within the building at 1911/1921/1931
Plymouth street. The wet-floor was constructed of rein-
forced concrete and was sloped to drain into the 1,500 gal-
~on wastewater sump.
o
The wastewater sump located immediately, behind the
1911/1921/1931 Plymouth street building. The sump received
wastewater discharged from the wet-floor. The sump was a
below grade, three compartment, reinforced concrete struc-
ture. . ,
o
The industrial sewer line connecting the wastewater sump
with the City of Mountain View sanitary sewer. Beginning at
the sump, the sewer line runs along the south and east sides
of the 1911/1921/1931 Plymouth Street building.
o
The drummed chemical staging area located immediately
the 1911/1921/1931 Plymouth street building. Drummed
materials in use during daily operations were placed
directly on the asphalt pavement. .
The warehouse located in'the eastern half of the 1905
Plymouth Street Building. Drummed chemicals were stored
within the warehouse on pallets and steel racks. Thewalls
were sealed at the floor with a mastic sealant.
behind
o
, '
The flammable materials storage area located behind the 1905
Plymouth Street building. The storage area consisted of a
concrete pad enclosed by a chain link fence and canopy.
The location of these areas are indicated in Figure ~.
0,
Field investigations described in section 5.2.1~ established that
the wet-floor and the wastewater sump located at the 1911/1921/
1931 Plymouth Street building were the sources of soil and' ,
groundwater contamination at ,the iO":'mer CTSfacility. For both
the wet-floor and the wastewater sump, the release of con-
taminants was attributed to deterioration of the concrete.
20
-------
5.2
DESCRIPTION OP CONTAKIHATION
5.2.1
SOIL XNVESTIGATIONS
From January 1985 to Hay 1987, CTS performed soil investigations
to identify sources of contamination and to determine the extent
of contamination. Nineteen (19) soil borings were drilled and 43
samples were analyzed to identify the sources of contamination.
The results from these samples indicated that the wet-floor and
the wastewater sump at 1911 Plymouth street were the sources of
contamination. Of the 19 soil borings, the highest concentration
of contaminants were found in soil boring HB6 which is adjacent
to the wastewater sump. The maximum concentration levels were
480 parts per billion (ppb) TCE, 69 ppb TCA, 69 ppb t-DCE, and
210 ppb toluene. Additional sampling efforts were focused on
defining the aerial "and vertical extent of contamination at the
identified source locations to ensure complete excavation of con- "
taminated materials. Ninety-two (92) soil samples were collected
from beneath the wet-floor building and 4 samples were collected
from beneath the wastewater sump. "Samples were analyzed for cop-
per, lead and VOCs. Prior to the excavation in September 1986,
the highest levels of contamination detected beneath the wet
floor were 22,000 parts per million (ppm) copper. 2,500 ppm lead,
and 0.380 ppm TCE. Department of Health Services (DHS) cer-
tified closure of the former CTS facility in October 1986. DHS
closure certification requires that the concentration of total
VOCs is less than or equal to 1~0 ppm. A summary of the soil
boring data is provided in Table 1.
5.2.2
GROUNDWATER INVESTIGATIONS
CTS has installed 38 monitoring and extraction wells to depths of
down to 7S feet. Twenty (20) wells are screened in the A zo~e "
(10 - 20'), 16 wells are screened in the B zone (30 - 40'), and 2
wells are screened in the Intermediate zone (60 - 75'). The
location of these wells are indicated in Figures 7 and 8.
" CTS submitted their first quarterly groundwater monitoring report
in February 1987. The contaminants detected in the ground water
are trichloroethene (TCE), 1,1,1-trichloroethane (TCA), 1,1-
dichloroethene (DCE), cis/trans-1,2-dichloroethene (c/tDCE), 1,1
and 1,2-dichloroethane (DCA), copper, lead, and nickel. The
plume boundaries in the A and B Zones are represented by the
isocontours for TCE in Figures 7 and 8. Volatile organic com-
pounds have not been detected in the deepest monitoring wells at
concentrati~nsabove 1.0 ppb. The area of ~he defined"
"ch~mically-affected groundwater plume is estimated to be 980,000 "
ft , for a rectangular area 1,400 feet downqradient from ES1W and
700 feet wide. The total shallow aquifer thickness is estimated
to be 20 feet." A summary of the groundwater data collected from
February 1987 to October 1989 is provided in Table 2.
In January 1988, the RWQCB and CTS agreed that the plume was ade-
quately defined provided chemical concentrations in the wells
marking the perimeter of the plume (33W, 34W, 35W, 36W, and 37W)
21
-------
- --I
....J«
-
OCJ
cci:2
00
o
a..
-------
.1 ...
.- ---,----
._- --.--
"Ion. .. .LUieJl 80UIIDUI88 1M . - I0Il.
-... . --.;
.,"'. ...
1',
~
--I
...J«
-
0"
a: a:
00
o
a..
-------
TABLE 1:
SOIL DATA SUMM~Y
Upper Maximum
Bound Arithmetic Obsened
Chemical Arithmetic Mean Concentration
Meanb
I,l-dichloroethane (l,l-DCA) 12.42 7.17 24
1,2-dichloroethane (1,2- DCA) 4.98 3.77 5
I, I -dichloroethene (DeE) 5.57 4.39 7.3
trans-I,2-dichloroethene (t-DCE) 46.29 24.50 110
methylene chloride (MeCI) 7.09 3.00 8
tetrachloroethene (PCE) 24.40 10.17 82
toluene (TOL) 139.47 81.38 230
I,I,I-trichloroethane (TCA) 24.12 13.01 69
trichloroethene (TCE) 94.30 45.74 220
copper. 45.17 41.75 . 5 I
leadC: 30.35 24.87 43
;
a. All concentrations in PS/Kg unless otherwise noted
b. 95 percent confidence limit of arithmetic mean
c. Concentrations in mg/Ks .
-------
TABLE 2:
GROUNDWATER DATA SUMMARY
Upper Upper Most
Bound 2. Bound I Plausible Maximum
Chemical Arithmetic Arithmetic Geometric Geometric. Observed
Meanb Mean MeanG Mean Concentration N
benzene (BZ) 0.66 0.39 0.55 0.33 0.93 .s
chloroforni- (CHL) 2.21 1.70 0.76 0.56 17 107
I,I-dichloroethane (I,I-DCA) 72.49 53.14 12.02 7.53 670 107
I,I-dichloroethene (DCE) .25.66 20.21 6.49 4.22 ISO 107
trans-I,2-dichloroethene (t-DCE) 63.24 48.06 10.12 6.26 400 107
I,I,I-trichloroethane (TCA) 81.45 59.91 15.49 9.78 580 107
trichloroethane (TC.I) 140.04 113.49 25.94 14.83 610 107
copper 75.71 58.33 74.76 47.21 100 12
lead 5.00 2.33 2.03 1.27 17 12
nickel 22.02 14.58 16.85 10.10 40 182
a. A II concentrations in Jl8fL
b. 95 percent confidence limit of arithmetic mean
c. 95 percent confidence limit of geometric mean
-------
did not increase. Chemical concentrations did increase in wells
33W and 34W and CTS was required to install an additional
.. monitoring well (38W) to define the western boundary of the
plume. Chemical concentrations in 38W (TCE = 50 ppb) were higher
than predicted by existing isocontours (Figure 7). In January
1991, CTS collected five groundwater samples using a HydroPunchTM
to define the western plume boundary or identify another source
of groundwater contamination. This last sampling effort verified
that another source of contamination exists upgrad~ent from the
facility. However, cTS was unable to mark the distinct western
boundaries of th~ plume. Based on the current unde~tanding of
the site and the data collected with the Hydropunch , the RWQCB
and EPA agreed that adequate information exists to select a final,
remedy. 'CTS is 'required to install additional monitoring welles)
to better define the westernboundary'of the plume, monitor the
influx of contaminants from any other sources, and monitor the
progress of remediation. The RWQCB will continue investigating
the source of the upqradient plume. '
6.0
. .' .
SUMMARY OP SITE RISES
6.1
TOXICITY ASSESSMENT
The Risk Asse~smentprepared for the CTS-Printex Superfund site
identified eleven chemicals of concern. The'distribution of .
these contaminants and their respective concentrations in ground
water and soil are described in Section 5. The eleven chemicals
.,of concern which are detected, in ground water and soils at the
s'ite are as follows: ': " ,
1,1-dichloroethane (l,l-DCA)
1,l-dich10roe.thylene (l,l-DCE)
1,2-dichloroethane (1,2-DCA)
trans-l~2-dichloroethene (t-DCE)
tetrachloroethylene (PCE) ,
toluene'
l,l,l-trichloroethane (l,l,l.;..TCA)
trichloroethylene (TCE)
methylene chloride (MeCl)
chloroform (CHL) ,
benzene (BZ)
The rational for selecting the listed chemicals as indicator
chemicals is as follow~:
, .
.' ,
i.i-Dichloroethane (l.l-DCA)
o
l,l-DCA possesses physiochemical properties (relatively high
water solubility and relatively low soil sorption) which
tend,to promote its dispersion in ground water;
o
l,l-DCA is classified by EPA as a B2 carcinogen, therefore,
it is a probable human carcinogen based on evidence ,from
animal experiments.,'
26
-------
.0
l,l-DCA is reported to cause teratogenic effects based on
evidence from animal experiments.
l.l-Dichloroethvlene ll.l-DCE)
o
o
l,l-DCE possesses physiochemical properties (relatively high
water solubility and relatively low soil sorption) which
tend. to promote its dispersion in qround water;
l,l-DCE is identified by EPA as a'possible'humari'carcinogen
(Group C) based on limited animal data.
. ,
o
_. ,
l,l-DCE is reported to cause reproductive, teratogenic, and
mutagenic effects based on evidence from 'animal .
experiments. .
1.2-Dichloroethane ll.2-DCA)
o
o
1,2-DCA possesses physiochemical properties (relatively high
water solubility and relatively low soil sorption) which
tend to promote is dispersion in ground water;
1,2-DCA is classified by EPA as a B2 carcinogen, therefore,
it is a probable human carcinogen based on evidence from.,
animal experiments.
o
o
1,2-DCA is reported to cause reproductive and mutagenic
effects based on evidence from animal experiments. .
Trans-l.2-Dichloroethvlene (t-DCE)
o
t-DCE possesses physiochemical properties (relatively high'
water solubility and relatively low soil sorption) which
tend to promote its dispersion in ground water;
t-DCE is reported to cause mutagenic effects based on
evidence from animal experiments.
o
1.1.2.2-Tetrachloroethylene (PCE)
o
PCE possesses physiochemical properties (relatively high
water solubility and relatively low soil sorption) which
tend to promote its dispersion in ground water;
PCE is classified by EPA as .a B2 carcinogen, therefore, it
is a probable human carcinogen based on .evidence from animal
experiments. .
o
PCE is reported to cause reproductive, teratogenic, ard
. ~utagenic effects based on evidence from animal experiments.
Toluene
o
RWQCB requests that this chemical be included as an
27
1"
'.
-------
indicator chemical.
Toluene is reported to cause reproductive, teratogenic, and
. mutagenic effects based on e~idence. from animal experiments.
l.l.l-Trichioroethane (l.l.l-TCA)
o
o
l,l,l-TCA possesses physiochemical properties (relatively
'- high water solubility and relatively low soil sorption)
which tend to promote its dispersion in ground water;
l,l,l-TCA is reported to cause reproductive, teratogenic,
and mutagenic effects based on evidence from animal
experiments~
Trichloroethylene .(TCE)
o
o
TCE 'possesses physiochemical properties (relativ~ly high
~ater solubility and relatively low soil sorption) which
tend to promote its dispersion in ground water;
TCE is classified by EPA as a B2 carcinogen, therefore, it
is a probable human carcinogen based on evidence from animal
experiment~. .
o
o
TCE is reported to cause reproductive, teratogenic, and
mutagenic effects based on evidence from animal experiments.
Methylene Chloride (MeCl)
o
MeCl possesses physiochemical properties (relatively high
water solubility and relatively low soil sorption) which
tend to promote its dispersion in ground water;
MeC1 is classified by EPA as a B2 carcinogen, therefore, it
is a probable human carcinogen based on evidence from animal
experiments.
o
o
MeCl is reported to cause teratogenic and mutagenic effects
based on evidence from animal experiments.
Chloroform
o
Chloroform possesses physiochemical properties (relatively
high water solubility and relatively low soil sorption)
which tend to promote its dispersion in ground water;
Chloroform is classified by EPA as. a B2 carcinogen, there-
fore, it is a probable human carcinogen based on evidence
. frOlil animal experiments.' .
o
o
Chloroform is reported to cause reproductive, teratogenic,
and mutagenic effects based on evidence from animal
experiments.
28
If>
-------
Benzene
o
Benzene possesses physiochemical properties (relatively
" high water solubility and relatively low soil sorption)
which tend'to promote its dispersion in ground water;
Benzene 1S classified by EPA as an A carcinogen, therefore,
it is proven to be a human carcinogen.
o
o
Benzene is reported to cause reproductive, teratogenic,
and mutagenic effects based on evidence from animal
experiments.' "
6.2
RISK CHARACTERIZATION
Exposure pathways were identified and evaluated for both the cur-
rent land-use conditions and for hypothetical future land-use
conditions. Assessment of potential risks under the current
land-use scenario was conducted to determine the degree that
chemical residues currently present'in soil and groundwater may
impact the health of humans who currently live or work within the
boundaries of the CTS plume. Assessment of potential risks under
the future land-use scenario was conducted with the assumption
that the Site, including the location of the facility, will De .
- converted into a typical residential area, and the population will
use the shallow aquifer ground water as a domestic potable water
supply. 'The future land-use scenario also assumes that the soil
beneath the former CTS facility will be disturbed due to future
construction activity.
Through a process of identifying and evaluating all of the poten-
tial exposure pathways associated with the contamination at the
site, the complete exposure pathways are identified. A complete
exposure pathway is one that has all the necessary components: a
source and mechanism of chemical release; an environmental
transport medium, a potential human exposure point, and a likely
, route of exposure. The 'exposure pathways 'which were determined
to be potentially complete for current land use and future land
use are as follows:
possible inhalation of indoor residential air containing
indicator chemicals that may have volatilized from con- '
taminated ground water and/or soil.
o "Exposure to indicator chemicals due tQ construction
activities 'disturbing subsurface soil involving both onsite
workers and offsite adults and children; potential exposure
pathways include injestion,' dermal contact, ,inhalation of
particulates, and inhalation of vapors.
o
o
Exposure to indicator chemicals due to use (as potable
water) of ground water extracted ,from wells (existing or
future installations) screened in the shallow 'aquifer;
potential exposure pathways include ingestion, dermal con-
29
-------
tact, and inhalation of vapors (e.g., showering);
The risks associated with each of these
evaluated using.toxicological data from
formation System (IRIS) data base. The
for the chemicals of concern applied in
provided in Table 3.
To protect public health, concentrations of chemicals which nave
been determined to cause or are suspected to potentially cause
cancer, based on animal studies, must be reduced. The levels
must be low enough that ingestion of 2 liters of water containing
the chemicals, every day for 30 years, can theoretically be ex-
pected to produce n04more than 1 excess cancer incidence per ten
thousand adults ~10-) to 1 excess cancer incidence per one mil-
lion adults (10-). EPA considers this Carcinogenic Risk Range'
to be an appropriate goal for cleanup actions. For chemicals
which are not carcinogens, cleanup alternatives must reduce their
total concentrations to a Hazard Index to 1 or lower. The Hazard
Index is calculated by dividing the amount of each chemical that
a person might be expected to. consume over time (the Chronic
Daily Intake) by the level for each chemical above which adverse
health effect~ may occur (the Reference Dose). The sum of these
ratios for all the chemicals of potential concern is the Hazard
Index. A hazard index of 1 or less means that no advers~ health
effects should occur from drinking water.
exposure pathways were
the Integrated Risk In-
toxicological properties
this evaluation are
To assess the potential risk associated with migration of in-
dicator chemicals from ground water into residential air, a' study
including a combination of field measurements and analytical
modeling was conducted at the site. Soil vapor emission rates'
were determined'and estimates of indoor air VOC concentrations
were calculated using a steady-state, single-compartment model
and the concentration .of contaminants in the ground water. Con-
struction parameters conservatively representative of homes
arounq the site were considered in deriving both hypothetical,
average-case and maximum-case indoor air concentration estimates.
Chemical flux rates were modeled for homes with slab floor foun-
dations and for homes with crawl spaces. Indoor air concentra-
tions were determined for benzene; chloroform; 1,1-DCA; 1,1-DCE;
TCE (carcinogens); t-1,2-DCE; and 1,1,1-TCA (noncarcinogens).
Using the assumption that an adult human receptor residing in the
house for 24 hours in a day for 40 years and that the determined
indoor vapor concentrations do not decrease or increase, the ex-
cess cancer risks and nQncancer risks were evaluated. The
highest excess cancer risk was for scenarios considered for the
off-site residences living in a house built with a crawl space;
the cgrcinogenic risks range were found to be 1.12 .x 10-5 to 2.9
x 10- and the noncarcinogenic risks were found to be less than
1.0. The carcinogenic and nonc~rci~ogenic risks for an off-site
res~dent living in a house with crawl space are described in
Table 4. .
~ "I
30
-------
TABLE 3:
TOXICOLOGICAL PROPERTIES FOR INDICATOR CHEMICALS
Chemical-
Carel
Non-
Carc.b
(R)eprod.
(T)eratog
.
(H)utag.c.
Rat
OraleS
LDso
(mg/Kg)
Rat Inha1.
LCtJJ .
(mg/mJ)
RfD '
II
(mg/Kg/day
)
RfDII
(mg/Kg/day
) .
SFh
'mg/Kg/day)-
BZ
tJR'
CHL
l,l-DCA
l,2-DCA
l,l-DCE
t-l,2-0CF.
MeC1
PCE
TOL
l,l,l..T{!A
TCE
A
B2
B2
B2
C
NC
62
62
NC
; NC
62
R T ~t
R T Ii
- T -
R - Ii
R T.K
- -. K
- T K
R T K
R T tot
R 'r K
R T K
:\ . 31e+ 3i
9.06a+2
7.25e+2
6.70e+2
.-.-.--
2.12e+3m
2.14e+3
3.0le+3
5.00e+3
1.03e+4
3.70e+3'
3.25e+4k
2.80e+4m
4.12e+3
-...-..
7.50e+4m
. 8. 80e+4k
2.76e+4
1. 53e+4
1.00e+5k
4.36e+4
............ .1
------
le-2 0
....--
le+O 0
10+0 1
..-...
....--
ge-3 0
-.-.-.
-.-...
-..-.-..
6e-2 0
ge-l'l
le-1 0
..-...'
4e-1 0
6e-l I
ge-l 0
3e+0 I
.--.-.
.--.-.
-....-.
-.....-
le-2 0
.......
le-l 0
le-l I
.......
-..."...-
ge-3 0
......
2e-2 0
.....-
6e-2 0
ge-l 1
10-2 0
-.....
3e-l 0
6e-l I
ge-2 0
3e-l 1
.. -,- .. .. ..
---.-.
2.ge-2 0
2.9c;)..2 I
6.1e-3 0
8.1e-2 I
9.18-2 0
........
9.le-20
9.1e-2 I
6e-l 0
1. 2e+0 I
...-.-..-
---.....
7.5e-30
1.4e-2 I
5.1e-20
3.3e-3 I
....----
...---.
......-.
.......
1.le-2 0
1.78-2 I
8.3e-7 0
8.3e-6 I
1.7e-70
2.3e-5 I
........
.......-
2.6e-6 0
2.6e-5 1
1.7e-50
5e-5 1
........
-.-.....
2.18-7 0
4.78-7 1
-.-.....
9.5e-7 I
........
.-------
-.-.----
--------
3,3e-7 0
1.7~-6 1
a.
i
8Z - benzene, CHL - chloroform, l,l-DCA - l,l-dichloroethane, l,2-DCA - l,2-dlchloroethane,
l,l-dichloroechene, t-l,2-0CE - trans-l,2-dichloroethene, KeCl - methylene chloride, PCE -
tetrachloroethene, TO~ - toluene, l,l,l-TCA - l,l,l-trichloroethane, TCE - trichloroethene
408.1.151TBLS.4-7(15)/CCTP6.tIL
\.
-------
Chemicals of Concern: Toxicological Properties
Former Printex Facility
Mountain View, CA (continued)
-\
a. BZ. benzene, CHL. chloroform, I,I-DCA .. I,I-dichloroethane, 1,2-DCA. J,2-dichloroethane, DCE.. J,J-dichloroethene, (-
DCE . trans-I,2-dichloroethene, MeCI .. methylene chloride, PCE .. tetrachloroethene, TOL . toluene~ TCA .. 1,1,1-
trichloroethane, TCE .. trichloroethene .
b. Carcinogenic classification (EPA, 1986a); A . human carcinogen, OJ . probable human carcinogen, limited human evidence, 82..
probable human car::inogen, inadequate human evidence, sufficient animal evidence, C .. posible human carcinogen. no human
evidence, limited animal evidence. NC .. noncarcinogen .
.:. Reproductive (R), teratogenic (T), or mutagenic (M) effects repo.rted (NIOSH, 1986)
d. Lethal dose fifly - a calculaled dose which causes Ihe dealh of 50% of the exposed experimental population
e. Lethal concenrralion low - Ihe lowest concenrration in air, other than the lethal concentration fifty, which has been reported to
cause death in Ihe exposed exp.erimental population
r. Reference dose for subchronic exposure (EPA, 1989b)
g. Reference dose for chronic exposure (EPA, J989b)
h. Slope factor for Inhalation (I) exposure or Oral (0) exposure (EPA, I989b)
i. Unil risk for Inhalation expOsure (~g/m3r1 or Oral exposure (~g/Lr1 from IRIS (EPA, 1989c)
j. Notation for 3.31 x 103 .
k. Lethal concentration fifty - a calculated concentration in air which causes the death of 50% of the exposed experimental population
I. No available dala :. .. .
m. Data for th~ mouse .
-------
I"
i
tABLE 4:
CARCINOGENIC AND NONCARCINOGENI~ tISRS FOR
CONTAMINANTS IN RESIDENTIAL AIR
----...
Slope
factor . Reference . Rlsk3'
(InhalaUon) Dosa MOO' LD' Risk' MOO2 LD2 Ri~ MOO3 LD3 MOO4 LD4 Risk4
I
Carcinoqens I
I '
I i I 7
Benzene 2.9)(10.2 ! 1.92)(10.7' 1.11x10'. 3.22x10.9 1.47)(10.7 8.4x10-8 2.44x10.9 3.85x10.7 2.20x10.7 6.38x10.9 2.96x10'7 1.69)(10.7 4.90x10'9
Chlarolonn 8.1)(10'2 1.92x10'7 1.11x10'7 8.99)(10'9 1.49)(10'7 8.51)(10-8 6.69)(10'9 3.88)(10'7 2.22x10.7 1.79)(10-8 2.99)(10'7 1.71)(10'7 1.38)(10-8
1,1.DCA 1.0)(10" 1.0)(10" 3.45)(10-6 1.97)(10-6 1.97)(10.7 2.69)(10-6 1.54)(10-6 1.54)(10.7 6.9)(10.7 3.94)(10-6 3.94)(10.7 5.35)(10-6 3.05)(10-6 3.05)(10.7
1,t.DCE 1.2)(10° 1.72)(10'11 8.83x10-6 1.18)(10':) 1.32)(10.11 7.54)(10-6 8.05)(10-6 3.45)(10'11 1.87)(10'11 2.36)(Hrll 2.64)(10'11 1.51)(10'11 1.81)(10'11
TCE 3.0)(10" 1.5~)(70'1I 8.68)(10-6 ~ 1.18)(10.11 6.74)(10-6 ~.02)(10-6 3.05)(10'11 1.74)(10':1 5.22)(10-6 2.33)(10':1 1.33)(10':1 3.99)(10-6
I
. I mlsk 1.45)(10.5 mlsk 1.12)(10.11 mlsk 2.9)(10.:1 mlsk 2.2x1 0.11
t!!!n: i
Carcinogens
'.1,2.DCE Oral Only 4.921(10-8 3.791(10-6 8.82)(10-6 7.56)(10-6
1".HCA 3.0)(10" 1.43)(10':1 4.77)(10':1 1.11)(10':1 3.7)(10'5 2.88x10':1 8.5)(10'11 2.18)(10':1 7.3)(10'11
!1niU
S:ope Factor (Inh~lation)(mg/Kg-dayr' (USEPA. 1989)
Maximum Daily Dose (MOD) mB/Kg-day
Lifetime Dose (LD) mB/Kg-day
Risk Unitless
Risk Scenarios
Risk 1 is based on 65% of the crawl space vapors being transmitted 10 living space and maximum plau:iible ventilation rate of 0.5 per hour
Risk2 is based on 50% of the crawl space vapors being transmitted to living space and maximum plausible ventilation rate of 0.5 per hour
RiskJ is based on 65% of the crawl space vapors being transmitted to living space and average ventilation rate of I per hour .
Risk4 is based on 50% of the crawl space vapors being transmitted to living space and average ventilation rale of I per hour
408.1. 'IJ-.2/TBl-6
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To assess the potential risks associated with disturbance of the
subsurface soil at 1911/1921/1931 Plymouth street a worst-case
"box" model was applied, assuming the total vapor emissions from
a three month construction period were bounded within a defined
space, 55 x 55 x 7 meters~ Assuming two rectanqular excavations
around the building of about 1.5 x 10.x 110 meters and a result-
ing soil pile of approximately 2,000 meters3, the emission rate
was calculated using a dispersion model. Assumptions included'
bare soil, mean annual wind speed of 2.41 m/sec, threshold wind
--velocity based. on a particle size-of 0.25 mm, and roughness ~or a
plowed field. The resulting air concentrations were 70 ug~m for
receptors that are 100 meters from the source and 1.0 mg/m for
receptors closer than 100 meters to the source. In the assess-
ment of the dose-response, adsorption rates for ingestion and in-
halation exposures were assumed to be 100 percent. Adsorption
for dermal 'contact was considered ~oo percent, but W&S adjusted
for a soil matrix effect. The potential receptors were assumed
to be'70 Kg onsite and offsite adults and 10 Kg offsite children.
Exposure periods included five days per week for workers and
seven days per week for offsite receptors. The highest
carcinogenic and noncarcinogenic risks were found for adult
workers within 100 meters of the s~irce; the carc!Rogenic risks
were found to range from 4.23 x 10 to 5.46 x 10 and the non-
carcinogenic ~azard indices were found .to range from 1.79 X.l0-4
to 3.41 x 10- (TableS). .
For determining the average-case carcinogenic and noncarcinogenic
risks associated with the hypothetical use of ground water. from
the shallow aquifer, domestic usage of shallow aquifer water com-
bined with other less significant exposure pathways (e.g.,
volatilization of VOCs from soil into ambient air, volatilization
from' ground water into indoor air, and leaching of VOCs from the
'soil into ground water) were assumed. Risks were evaluated con-
sidering that the concentration of contaminants in the ground
water were the geometric mean, with an upper. bound calculated as
the 95 percent confidence limit of the geometric mean. The
highest carcinogenic and noncarcinogenic health risks were found
. for residential children based on the upper 95 percent confidence
limit of the geometr!i mean; the c~5cinogenic risks ~ere f~und to
range from6.7~ x 10 . to 4.7 x 10 and the noncarc~nogen~c
hazard indices were found to range from 0.204 to 1.57 (Table 6).
6.3
PRESENCE OP SENSITIVE BUHAN POPULATIONS
The City of Mountain View has a residential population of ap-
proximately 61,000, of which 90% live upgraaient of the CTS site.
The land surrounding the facility is zoned for light industrial/
manufacturing, commercial, residential, and agricultural land
use. In recent years, the off-site area, especially north of
u.s. Highway 101, has been progressively converted from a
residential and agricultural area to a light industrial commer-
cial area. There are no schools, hospitals, or convalescent.
homes located within the boundaries of the contaminant plume.
33
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TABLE 5:
CARCINOGENIC AND NONCARCINOGENIC RISKS FROM SOIL
CONTAMINATION
1 Soil
Nonea rcl noge n IcEfI ec ts. - Carcinogenic Rlskb
Onslle Offslle o ffs lie Onslte OUsUe Offslle
Adull Adull Child Adull Adult . Child
Workers Residents Residents Workers Residents Residents
IngestionC 2.35 x 10" 2.35 x 10" 3.28 x 10'" 4.59 X 10.11 6.96 X 10.11 9.75 X 10,10
Dermal
Contact' 8.19 x 10" 1.27 x 10" 2.52 X 10'4 . 1.60 X 10.10 3.76 X 10'11 7.49 X 10.10
Vapor
Inhalationd 2.36 x 10'" 7.05 x 10" 1.23 x 10'" 5.44 x 10-8 2.46 x 10-8 4.58 X 10-8
TOTAL 3.41 x 10'" 1.07 x 10'" 7.03 x 10'" 5.46 X 10.8 2.47 x 10" 4.75 x 10"
a. Ratio of Maximum Daily Dose (MDD) to Reference Dose (RfD)
b. Lifetime Average Daily Dose (LD) multiplied by Slope Factor (SF)
c. . Maximum Observed Concentration
d. Upper Limit Arithmetic Mean
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TABLE 6:
CARCINOGENIC AND NONCARCINOGENIC RISKS FROM
DOMESTIC USE OF SHALLOW AQUIFER
nt
Noncarcinogenic Errects. Carclnoeenlc Rlskb
Onslte Orrslte Orrslte Onslte OHsICe OHsICe
Adult Adult . Child Adult Adult Child
Workers Reslden.s Reslden.s Workers Residen.s Residents
Ingestion 2.25 x 10.1 2.25 x 10.1 7.86 X 10" ' 4.43 x 10" 6.72 x 10" 2.35 x 10.3
Other
ActiYitiesC: 2.25 x 10.1 2.25 x 10-1 7.86 X 10"1 4.43 x 10" 6.72 x 10" 2.35,x 10'3
TOTAL 4.50 x 10" 4.50 X 10-1 1.57 X 10-0 8.86 x 10" 1.34 X 10-3 4.70 X 10"3
\
a. Ratio or Maximum Daily Dose (MDD) to Reference Dose (RfD)
b. Lifetime Average Daily Dose (LD) multiplied by Slope Factor (SF) .
c. Exposure via inhalation and dermal contact during other household activities involving water was considered
approximately equivalent to that from ingestion . .
-------
.." currently, the shallow aquifer is not known to be used for
residential, commercial, or agriculture purposes.
6.4
PRESENCE OP SENSITIVE ECOLOGICAL SYSTEMS
The San Francisco Bay Wildlife Refuge is located approximately
four miles north of the facility and comprises approximately. .
19,000 acres (Figure 2). In 1988, the Refuge was authorized to
acquire an additional 20,000 acres. The habitat is primarily
salt marsh with some mud flats, salt ponds, upland, and open
water areas. The Refuge is the habitat of five endangered
species: California clapper rail, Peregrine falcon, California
least tern, California brown pelican, and the salt marsh harvest
mouse. The San Francisco Bay Wildlife Refuge is not affected by
the site. .
CTS reviewed the California Natural Diversity Database in order
to identify endangered and threatened species near' the site. No
endangered or threatened species, special plant, special animals
or protected communities were identified at the former Printex
facility. The nearest endangered species entries were: 1) a
non-specific one-mile radius entry based on the 1982 observation
of a pair of Burrowing Owls, in the vicinity of Mayfield and
Charleston slough, in Palo Alto (approximately 1.8 m~les from the
former printex boundary); and 2) a non-specific point entry based
on the 1985 siting of two pairs of breeding Saltmarsh Common
Yellowthroat in the vicinity of Charleston slough and Bayshore
Freeway, northeast of Palo Alto (approximately 1.1 miles from the
former printex boundary). No endangered species, special
animals, or special plants were identified within 1.0 mile from
the boundary of the site. .
6.5
CONCLUSION
Actual or threatened releases of hazardous substances from the
CTS Superfund site', if not addressed by implementing the response
action selected in this ROD may present an imminent and substan-
tial endangerment to the public health, welfare or environment.
Based on the fact that a variety of the VOCs detected at the site
pose significant health risks as either carcinogens or noncar-
cinogens, and complete exposure pathways exist, EPA has deter-
mined that remediation is warranted.
7.0
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARS)
Under section 121(d) (1) of CERCLA, 42 U.S.C. S 9621, remedial ac-
tions must attain a degree of clean-up which assures protection
of h'xma~ health and the environment. Additionally, remedial ac-
t~on~ that leave any hazardous substance, pollutant, or con-
taminant on-site must meet a level or standard of control that at
least attains standards, requirements, limitations, or criteria'
that are "applicable or relevant and appropriate" under the cir-
36
fl.
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cumstancesof the release. These requirements, known as "ARARs",
may be waived in certain instances, as stated, in Section
121(d) (4) of CERCLA, 42 U.S.C. S 9621(d) (4).
- ,
"Applicable" requirements are those clean-up standards, standards
of control and other substantive environmental protection re- .
quirements, criteria, or limitations promulgated under federal or
state law that specifically address a hazardous substance, pol-
lutant or contaminant, remedial action, location, or other cir-
cumstance at a CERCLA site. "Relevant and appropriate" require-
ments are clean-up standards, standards of control and other sub-
stantive environmental protection requirements, criteria, or
limitations promulgated under federal or state law that, while
not "applicable" to a hazardous substance, pollutant, con-,
taminant, remedial action, location, or other circumstance at a
CERCLA site, address problems or situations sufficiently similar
to those encountered at the CERCLA site that their use is well-
suited to the particular site. For example, requirements may be
relevant and appropriate if they would be "applicable" but for
jurisdictional restrictions associated with the requirement. See
the National Contingency Plan, 40 C.F.R. Section 300.6, 1986).
The determination of which requirements are "relevant and ap-
propriate" is somewhat flexible. EPA and the State may look to
the type of remedial actions contemplated, the hazardous' sub-
- stances present, the waste characteristics, the physical charac-,
teristics of the site, and other appropriate factors. It is pos-
sible for only part'of a requirement to be considered relevant
and appropriate. Additionally, only substantive requirements
need be followed. If no ARAR covers a particular situation, or
if an ARAR is not sufficient to protect human health or the en-
vironment, then non-promulgated standards, criteria, guidance,
and advisories 'must be used to provide a protective remedy. .
7.1
TYPES OF ARARS
There are three types of ARARs. The first type includes.
"contaminant specific" requirements. These ARARs set limits on
concentrations of specific hazardous substance, pollutants, and
contaminants in the environment. Examples of this type of ARAR
are ambient water quality criteria and drinking water standards.
The second type of ARAR includes location-specific requirements
that set restrictions on certain types of activities based on
site characteristics. . These include restriction on activities in
wetlands, floodplains, and historic sites. The third type of.
ARAR- includes action-specific requirements~ These are
technology-based restrictions which are triggered by the type of
action under consideration. Examples of action-specific ARARs
are Resource Conservation and Recovery Act (IIRCRA") regulations
for waste treatment, storage, and disposal.
37
is>
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ARARs must be identified on a site-specific basis from informa-
tion about specific chemicals at the site, specific features of
the site location, and actions that are being considered as
remedies.
7.2
CHEMICAL-SPECIFIC ARARS
Section 1412 of the Safe Drinkina Water Act. 42 U.S.C. section
300a-1 . - _.- ...--.
Under the authority of Section 1412 of the Safe Drinking Water
Act, Maximum Contaminant Levels Goals (MCLGs) that.are set at
levels above zero, shall be attained by remedial actions for
ground or surface water that are current or potential sources of
drinking water, where the MCLGs.are relevant and appropriate un~
der the circumstances of the release based on the factors in 40
CFR 5300.400 (g) (2). -
The appropriate cleanup level for each indicator chemical (except
toluene) in ground water is the MCLG (if not equal to zero), the
federal MCL, or the State MCL, whichever is most stringent. The
MCLGs and MCLs for the indicator chemicals identified at the site
are shown in Table 7.
California DeDartment of Health Services Drinkina Water Action
Levels (DWALS}
California Department of Health Services (DHS) DWALS are health-
based concentration limits set by the DHS to limit public ex-
posure to substances not yet regulated by promulgated standards.
They are advisory standards that as well head treatment for
public water supplies. .The DWAL for toluene is 100 ppb.
California's Resolution 68-16
California's "statement of POlicy With.Respect to Maintaining
High Quality of Waters in California," Resolution 68-16, affects
remedial standards. 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
present or potential uses, and will not result in water quality
less than that prescribed by other state policies. .
7.3
ACTION SPECIPIC ARARS
city of Mountain View Industrial Waste Ordinance and the Federal
Clean Water Act Pretreatment standards (40 CFR 403.5)
Substantive requirements. of the city of Mountain View Industrial
Waste Ordinance and the Federal Clean Water Act Pretreatment
Standards (40 CFR 403.5) are ARARs for discharges of ground water
to the local sanitary sewer system. The Clean Water Act allows
38
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CLEANUP LEVELS FOR GROUND WATER
U.S. EPA U.S. -EPA California
,MCLG MCL MCL
Chemical (ppb) (ppb) (ppb)
1,1-DCA -- 5'
1,1-DCE 7 7 6
1,2-DCA 0 5 0.5
t-DCE 100 100 10
PCE 0 " 5 5
1,1,1-TCA 200 200 200
TCE 0 5 5
Toluene 1000 1000 100(2)
Benzene 0 5 1
Chloroform 100
MeCl 0 5
( 1)
(2)
MCL for cis-1,2-DCE
DHS action level
TABLE 7:
CHEMICAL SPECIFIC ARARS
"
- 39
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municipalities to determine the pretreatment standards for dis-
charges to Publicly OWned Treatment Works (POTWs) within its
jurisdiction.
.. -
7.4
LOCATZOH-SPBCZFZC ARARB
There are no location-specific ARARs associated with the Site.
8.0
DBSCRZPTZOH OF ALTERHATrvBS
The analysis of remedial technologies, presented in the
feasibility study report, resulted in the development of three
alternatives for site remediation. These .alternatives are sum-.
marized below.
Alternative 1
No Action
- -
The No Action alternative serves as a baseline for comparing
other remedial alternatives. Under the No Action alternative, no
additional remedial technologies would be implemented and opera-
tion of presently implemented remedial actions would cease.
Alternative 2 - Institutional Actions
The Institutional Action alternative involves restricting well
permits for the installation of wells with a sanitary seal not
less than 100 feet below ground surface, stopping current
groundwater extraction activities, and monitoring only selected
wells in the area affected by groundwater contamination. Well
permit restrictions are promulgated by the Santa Clara Valley
Water District (SCVWD) in Ordinance 90-1 to prevent the use of
shallow groundwater in the region. According to this ordinance,
water wells may not be screened at depths shallower than 50 feet.
CUrrent policy of the SCVWD does not allow permits for drinking
water wells in the shallow groundwater aquifer.
Alternative 3 - Extraction and Discharae to the Sanitary Sewer
This alternative involves continued operation of the existing
groundwater extraction system. The system is comprised of seven
extraction wells drawing approximately 48 qpm and discharging un-
treated water to sanitary sewer for treatment at the POTW.
This alternative does not include treatment prior to discarge to
the POTW. The City of Mountain View permits total organics equal
too~ less than 1 ppm at a point of discharge. This alternative
provides passive air stripping created by passing water through
the sewer collection system and through the sewage treatment
plant. The RWQCB and the City of Palo Alto require that
groundwater use is reevaluated prior to renewing the POTW dis-
charge permit in January, 1992. Groundwater extraction will con-
tinue until the cleanup standards listed in Table 7. are acheived.
Potential modifications which may be applied to this alternative
to increase effectiveness are described in section 9 under the
"Long-Term Effectiveness" criterion.
40
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9.0
COMPARATIVE ANALYSIS 01' ALTERNATIVES
This section provides an expl~nation of the ~riteria used to .
select the remedy, and analyses of the remedial actionalterna-
tives in liqht of those criteria, hiqhliqhtinq the advantaqes and
disadvantaqes 'of each of the alternatives. .
Criteria
The alternatives were evaluated usinq nine component criteria.
These criteria, which are listed below, are derived from require-
ments contained in the National Continqency Plan (NCP), 40 C.F.R.
S 300 et sea. and CERCLA sections 121(b) and 121(C).
o Overall Protection of Human Health and the Environment;
o
o
o
o
o
o
o
o
Compliance with ARARs;
Reduction of Toxicity, Mobility, or Volume Through
Treatment; .
Long-Term Effectiveness and Permanence;
Short-Term Effectiveness;
Implementability;
Cost;
Support Agency Acceptance;.
~ommunity Acceptance.
OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
Alternative 1 and 2 neither reduce nor eliminate the risks as-
sociated with contamination of the shallow aquifer at the Site.
The carcinogenic risk for adult residents would range from 1.34 x
10-3 to 1.93 x 10- a2d the noncarc~nogenic hazard index would
range from 5.84 x 10- to 4.5 x 10-. Thiscarcinoqenic risk
level. is unacceptable.. . ..
Alternative 3 provides protection of human health and the en-
vironment by reducing the volume of contamination in the Sharlow
Aquifer and thereby reducing all risks associated with presence
of VOCs in the qround water. The calculated health risk after
the remedial ob~ectives6are achieved will be within EPA's target
risk range, 10- to 10- , and the noncarcinogenic hazard index
will be less than 1.0. ..
COMPLIANCE WITH ARARs
Alternatives 1 and 2 do not comply with the chemical specific
ARARs set forth in Section 7 of this report. Alternative 3 would
attain all pertinent ARARs set forth in section 7.
41
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REDUCTION OF TOXICITY. MOBILITY. OR VOLUME THROUGH TREATMENT
Alternatives 1 and 2 do not reduce toxicity, mobility, or vol~~e
through treatment.. .
Alternative 3 provides reduction of toxicity, mobility, and
volume by reducing the concentration of contaminants in the Shal-
low Aquifer and by containing the contaminant plume within the
--capture zone created by the extraction wells. Alternative 3 does
not include treatment other than the volatilization and degrada- .
tion of VOCs at the POTW. This treatment does not provide com-
plete destruction of chlorinated hydrocarbons.
LONG-TERM EFFECTIVENESS AND PERMANENCE
Alternatives 1 and 2 do not provide any effective measure for
remediating qroundwater contamination. Therefore,. risks as-
sociated with presence of this contamination remain unaffected.
Alternatives 1 and 2 do not provide long-term effectiveness or
permanence. . .
. Alternative 3 includes groundwater extraction which is intended
to reduce the level of contamination in the Shallow Aquifer below
the cleanup levels listed in Table 7. Thus, potential risks to
the community currently posed by the site in its present condi-
tion are minimized. To ensure that the magnitude of residual
risks are minimized, the performance of the groundwater extrac- .
tion system will be carefully monitored on a reqular basis and
adjusted as warranted by the performance data collected during
operation. Modifications may include: . .
a)
discontinuing operation of extraction wells in areas where
cleanup standards have been attained;
alternating pumping at wells to eliminate stagnation points;
b)
c)
pulse pumping to allow aquifer equilibration and encourage
adsor1>sd contaminants to partition into ground water;..
d)
installation of additional extraction wells.
Treatment by POTW provided by Alternative 3is reliable for the
complete or near-complete removal of VOCs from the extracted
qround water. Treatment residuals are expected to be low, based
on the high volatility of the VOCs. Therefore, Alternative 3
provides long-term effectiveness and permanence.
SHORT-TERM EFFECTIVENESS
Alternatives 1 and 2 do not include the implementation of any
remedial action, therefore, there are no risks associated with.
the implementation of. a remedy. The risks associated with the
contamination of the Shallow Aquifer would remain at the Site. .
42
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Alternative 3 will create minimal short-term impact to the health
of the workers and the community because the groundwater' extrac-
tion system is already in place at the s~te.
IMPLEMENTABILITY .
There are no technical concerns regarding the implementability of
Alternatives 1 and 2.
Alternative 3 involves operating the existing groundwater extrac-
tion system without implementing any additional wells. Addi~ .
tional monitoring welles) will be installed to monitor the Shal-
low Aquifer upqradient of the Site. However, there are no techni-
cal considerations that prohibit the installation of these wells.
COST
There are no costs associated with Alternative 1.
The capital cost for Alternative 2 is $13,450 in 1991 dollars. .
operation and maintenance costs associated with monitoring and
deed restrictions are $71,580 per year and the present worth is
estimated to be $1,098,000.
The capital cost for Alternative 3 is $61,000 in 1991 dollars.
Operation and maintenance costs associated with monitoring and
sewer disposal fees are estimated to be $104,700 per year and the
present worth is estimated to be $786,000.
The present worth of Alternative 2 is greater than Alternative 3
. because the present worth for Alternative 2 is calculated over a
19 year period and the present worth for Alternative 3 is calcu-
lated over a 15 year period.
SUPPORT AGENCY ACCEPTANCE
The Feasibility Study and the Proposed Plan Fact Sheet were
reviewed by. r.alifornia Regional.Water, Quality Control Board
(RWQCB}. . The ~wQCB concurs with Alternative 3, EPA's preferred
alternative.
COMMUNITY ACCEPTANCE
The Proposed P~an was presented to the community of ~ountain View
in a fact sheet and at a pUblic meeting. No technical comments
were submitted regarding the alternatives. Other comments'
received are addressed in the Response Summary.
THE SELECTED REMEDY
The selected remedy for the Site is Alternative 3~ Alternative 3
conslsts of continuing the current groundwater extraction system.
Extracted water will be discharged under permit to the sanitary
43
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sewer. The current groundwater extraction system consists of 7
extraction wells; 4 A-zone wells and 3 B-zone wells. The flow
rate of the system is approximately 45 gallons per minute (qpm).
Alternative 3 is required to achieve the cleanup standards listed
in Table 7. By returning the shallow aquifer to drinking water
quality, the risks associated with future dome~tic use will
achieve EPA's target risk range of 10-4 to 10- for the chemicals
of concern, thereby eliminating the most significant exposure
pathway. Extracted ground water will continue to be discharged
under permit to the sanitary sew~r.-. According to the"Quarterly
Monitoring Report dated April 15, 1991, the highest total con-
centration of VOCs discharged to the sanitary sewer is 803 ug/L.
The City of Mountain View permits a total concentration of or-
ganics equal to or less than 1 ppm at a point of discharge. The
capital cost for Alternative 3 is $61,000 in 1991 dollars.
operation and maintenance costs'associated with monitoring and
sewer disposal fees are estimated to be $104,700 per year and the-
presel'lt worth is estimated to be $786,000. , --,
The goal of this remedial action is to restore ground water to
its beneficial use, which is, at this site, a potential drinking
water source. Based on information obtained during the-remedial
investigation and on a careful analysis of all remedial alterna~
tives, EPA and the RWQCB believe that the selected remedy will
achieve this goal. It may become apparent, during operation of
the ground water extraction system and its modifications, that
contaminant levels have ceased to decline and are remaining con-
. stant at levels higher than the remediation over some portion of
the contaminated plume. In such a case, the system performance
standards and/or the remedy may be re-evaluated.
a)
b)
c)
I -
I
d)
The selected remedy will include ground water extraction for an
estimated period of 5 to 19 years, during which the system's per-
formance will be carefully monitored on a regular basis and ad-
justed as warranted by the performance data collected during
operat,ion. Modifications may include any or all of the follow-
'~g:. .
at individual wells where cleanup goals have been attained,
pumping may be discontinued;
alternating pumping at wells to eliminate stagnation points;
pulse pumping to allow aquifer equilibration and to allow
adsorbed contaminants to ~artition intq ground water; and
installation of additional extraction wells to facilitate or
accelerate cleanup of the contaminant plume. .
To ensure that cleanup levels continue to be maintained, the
aquifer will be monitored at those wells where pumping has
ceased. '
44
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'10.0 STATt1'1'ORY DETBRKINATIONS
- The selected remedy will reduce the concentration of contaminants
in the Upper Aquifer to levels which are protective of human
health and the ~nvironment by extracting contaminated ground
water and discharging untreated water to the sanitary sewer. By
removing the contaminants from the Upper Aquifer, the car-
cinogenic and noncarcinogenic risks attributed to ingesting
. --ground water --containing contaminants at the levels described in
section 5.2.2 are reduced to within EPA's target risk range.
Therefore, the only exposUre pathwal posing a potential car-
cinogenic risk greater than 1 x 10- is controlled. The risk as-
sociated with the exposure pathway created by discharging cog-
taminated water into the sanitary sewer is less than 1 x 10- .
. The selected remedy is required to achieve chemical specific
ARARs for all the contaminants identified in the Upper Aquifer.
The chemical-specific ARARs for this Site are listed .in Table 7.
The action~specific ARAR for this site is to comply with the City
of Mountain View , discharge requirement for the sanitary sewer.
The selected remedy effectively reduces the primary risk as-
sociated with the,Site and does not create unacceptable short-
term risks. Therefore, the selected remedy provides the most
cost effective risk reduction for the Site.
Because of the considerable time required to achieve health-based
levels, a five-year review, pursuant to CERCLA Section 121, 42
U.S.C. Section 9621, will be conducted at least once every five
years after initiation of the remedial action to ensure that the
remedy continues to provide adequate protection of human health
and the environment.
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES
The remedy selected in this ROD is consistent with the alterna-
, tive selected in the proposed plan. '
45
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xx.
i .
RESPONS%VBNBSS 8tJHKARY
46
16'
.<
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RESPONSIVENESS SUMMARY
CTS CORPORATION
FINAL SITE CLEANUP REQUIREMENTS
Introduction/Summary
----This responsiveness summary responds to comments and questions received during
the 39-day public comment period regarding the proposed final re'medyfor the former
CTS Printex Corporation site. The remedy is presented in the Tentative Site Cleanup
Requirements (SCR), Remedial Investigation and Feasibility Study (RI/FS), and the
Regional Board Proposed Plan Fact Sheet for the former CTS Printex. site. The final
public comment period on the SCR, RI/FS, and proposed plan was from March 20,
1991 to April 19, 1 9~n. The Board held an initiai pubiic hearing on the SCR on March
20, 1.991 at which' time CTS commented on the Tentative Order. These comments
are repeated below. A community meeting was held in Mountain View on March 21,
1991; there were no comments received at this meeting.
Four. comment letters on the SCR were received from CTS Corporation, .EP A, the
Santa Clara Valley' Water District, and the Regional Water Quality Control Plant for the
City 01 Palo Alto. In response to these comments, no changes were made to the
cleanup standards or methods of achieving those standards. The only significant
change was the addition of specific items needed before cleanup measures can be
discontinued (Provision 2.i.). Other changes were either typographical or minor
procedural text changes for clarification. .
Responses to Speci~~ Comments
City of Palo Alto
There were two comments from the Regional Water Quailty Control Plant for the, City
of Palo Alto. The first comment concerned the discharge 01 ground water to the city
sewer and how most 01 it would volatilize in the sewer system or at the facility, and
the risk associated with this volatilization. In the Baseline Public Health Evaluation,
CTS evaluated total volatilization 01 the current discharge as a worst case scenario,
and found that the risk (i.e., 6.6 x 10 -6) is within acceptable levels. The second
comment was a request that extracted ground water be considered for possible reuse
.in the vicinity 01 the site. This is also a concern for the Board and the SCR includes
a task to evaluate the use 01 the groundwater rather then discharging it to the sewer.
.'
fI-
'.
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ReSDonsiveness Summarv
CTS CorDoration
Final Site CleanuD Reauirements
CTS CorDoration
CTS submitted extensive (eight pages) of detailed comments on the SCR. Many of
these were typographical and procedural (i.e., the appropriate current name for the
company), and they have been changed in the current Tentative Order. All comments
have been incorporated into the Final SCR except 8S noted below. The numbers
correspond to CTS's comments.
2.E.
3.F.
4.E.2.
5.B.3.
6.B.
I-'.A,
10.
13.A.
15.A.
15.C.
Did not change site history because this was not indicated in the RifFS.
The Responsiveness Summary will be made a part of the record tor the
Final Tentative Order. .
Did not change because additional upgradient well(s) will be needed and
are required by the Order. .
Did not add the last sentence that begins with "In that..." The Board
may issue an Order for CS Services but this does not relieve CTS
Corporation of its responsibility tQ clean up chemicals originating from its
s~e. '
Since toluene was found in soil at the site, the proposed wording that
toluene is probably not associated with site activities will not be added.
Long term monitoring will be required, but the time frame and specific
wells .will be determined at an appropriate future date, based upon either
responsible party or Board. initiative, or during the required five-year
review.
This is standard wording in .all tinal cleanup orders, and the proposed.
wording is too limiting.
"Pollutant" is a more general term and is more appropriate for cleanup
orders.
CTS is responsible for all contamination associated with its site and must
demonstrate to the Board that ~II the contamination from the site is
cleaned up as required by the Board-adopted order. Provision 2.i. has
been added to define the conditions under which remediation may cease.
-'
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ResDonsiveness Summarv
CTS Corooration
Final Site CleanuD Reouirements
16.A.1.
16.A.2.
16.A.3.
1'.C.
1'.D.
1" .E.
Retained the word 8additional8 so that the five-year evaluation covers
only investigations since the RI/FS. .,
Changed .polluted. to .contaminated..
Did not change '-and lor soil remediation- because it is possible that
there may be an undiscovered source, and/or cleanup standards may
change.
Staff believes that it is appropriate to retain these information requests
at quarterly intervals. This would be consistent wi~h other SOtJth Bay
sites.
The annual report can be part of the fourth quarter report due January
15,1992.
Resubmission of these reports is only necessary when site conditions or
standards change. .
. .
, .
US Environmental Protection Agencv
Each of EPA's comments are addressed separately below.
Finding 5:
Castro Paint is not being named as a potential responsible party because the
hydropunch sample taken at the corner of their property did not exhibit any VOCs and
the soil data at their site had very had low levels of TCE. .
Finding 9:
Board. staff exp.anded Finding 21 describing remedial actions to include soil
remediation.
Finding 10:
The plume is defined according 10 '(he hydropunch data collected by CTS in early
1991 in the vicinity of wells 34W and 38W. This data showed non-detect leve 15 in
groundwater north and west of these wells, thus defining the plume.. .
3
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ResDonsiveness Summary
CTS CorDoration
Final Site CleanuD Recuirements
Finding 14:
--' --..--
.'--'-
The chemicals of Concern do represent all" of the contaminants present in the aquifer.
Finding 15:
There is no evidence that PermanenteCreek is effected by the activities associated
with the former CTS Printex facility. Potential impacts from this site are much lower
than aquatic toxicity criteria. .- ..
Finding 16:
See response to City of Palo Alto comment #2. The risk has been found to be at
acceptable levels. Other exposure pathways include inhalation of VOCs through
domestic use of ground water.
Finding 22:
The only alternative considered for soil was 'no action' since '~o risk was associated
with it.
.....;,..
Permanente Creek is currently being sampled by Teledyne.Spectra Physics. There is
a clean monitoring well located between the creek and the CTS Printex facility plume.
For these reasons, staff feels that it is not necessary to monitor the creek.
Finding 23:
The cost numbers will be adjusted so that they include past, present, and future.
Finding 24:
.Significant Quantities. will no longer be extracted when either cleanup standards are
. met or conditions for an ARAR waiver are met. In either case, a decision will be made
by the Board and EPA through the public hearing process. .
.0
Santa Clara Vallev Water District
Staff acknowledge that the District's ordinance only requires a sanitary seal that
extends 50 feet and ending at least 5 feet into a significant aquitard. There will also
be a deed restriction placed on the site, restricting installation of drinking water wells.
4
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REGIONAL WATER QUALI'IY CONTROL, PLANT
2501 Embarcadero Way
Palo Alto, CA 94303
TELEPHONE: .,5/3&25.
OPERATED 8Y THE C1'TY OF PALO ALTO
. _uSERVlNG: EAST PAlO ALTO. LOS ALTOS. LOS ALTOS HIUS. MOUNTAIN VIEW. PAlO ALTO. STANFORD
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Mr. Tom Benz/
Regional Water Quality Control Board
San Francisco Bay Region
2101 Webster Street, Suite 500
, Oakland; CA 94612
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March 28, 1991
Dear Mr. Benz: .
... .
The purpose of this letter is to provide comments on the proposed clean-up plan for the
crs Printex Superfund Site. Equally important we are forwarding new criteria for the
issuance of contaminated groundwater sewer discharge permits. As the attached policy
indicates we will no longer issue such permits, or increase flow limitations in existing
permits, unless documentation is provided from the applicant demonstrating that all
alternatives for use of the water Orrigation, industrial processes, etc.) have been explored
in the vicinity (not just on-site) of the extraction wells and that none are practical.
Needless to say the reason for this new policy is the large cutback in potable water use
which all of our partner cities are facing.
Our comments are:
1.
Alternative 3, the recommended alternative, (page 5 of March 1991 fact
sheet) indicates that the extracted groundwater would be .sent untreated to
the City of Mountain View sewage treatment facility, where it is treated ...0-
We do not believe that a substantial portion of the chlorinated hydrocarbons
of the type from CTS are "treated- at our facility. The literature suggests
that almost all of it is merely volatilized, either in the sewer collection system
or at the plant. The crs risk assessment should be revised accordingly.
2.
Altemative 3 should be revised to indicate that the applicant must
demonstrate that use of the water in the vicinity of the extraction wells is not
practical before a sewer use 'permit would be. issued. A temporary or
conditional permit may be possible to allow completiohof the use evaluation
or to allow discharge at certain times. '
1
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Thank you for your agency's consideration of these comments.
Sincerely, .
~~
Phil Bobel, Manager
Environmental Compliance Division
Enclosure
cc: Mark Harris, City of Mountain View
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CTS~
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COMMENTS ON DRAFT ORDER FORWARDED BY LETTER
FROM STEPHEN I. MORSE DATED MARCH 7, 1991
1. EXECUTIVE OFFICER SUMMARY REPORT, DISCUSSION SECTION.
Midway through the first paragraph is the following
sentence:
"DHS certified that the buildings and soil under the wet
floor no longer contained hazardous waste and certified the
site for closure."
The intent of closure under RCRA is to assure that a
facility regulated under Parts 264 or 265, at the tine of
closure, is returned to a condition such that the facility
no longer presents any potential threat to human health or
the environment. Secondly, DHS does not "certify*1 closure,
but accepts closure certification from the owner/operator
and an independent registered professional engineer. Thus,
the above sentence should be revised as follows:
"It was determined that all soils that posed a potential
threat to human health or the environment had been removed,
and the buildings rendered in a clean condition. Thus, in
accordance with DHS regulations and the approved Closure
Plan for the site, DHS accepted closure, and the site was
returned to the owner for remodeling and re-leasing to a new
tenant."
2. TENTATIVE ORDER, PAGE 1
A. Top of page, change "CTS PRINTEX CORPORATION" to "CTS
CORPORATION".
B. Item 1, site Location and Description. 1st paragraph.
1. Line 1. Change "CTS PRINTEX CORPORATION (CTS)" to
"CTS PRINTEX (PRINTEX)".
2. Line 4. Change "CTS" to "PRINTEX".
3. Line 5. Change "CTS" to "CTS CORPORATION, PARENT
CORPORATION FOR THE FORMER PRINTEX FACILITY".
C. Item 1, Site Location and Description,. 2nd paragraph,
Line 1. Change "CTS" to "PRINTEX".
D. Item 1, Site Location and Description. 3rd paragraph,
Line 2. Change "the CTS" to "CTS CORPORATION".
E. Item 2, Site History. 1st paragraph, Line 3. Other
types of manufacturing were known to occur at the site.
Thus, the last sentence should be deleted.
F. Item 2, site History. 2nd paragraph.
1. Line 2. After the words "the site", add the words
"since 1970".
2. Line 2. After the words "CTS CORPORATION", add the
phrase "from Anglo Energy, Inc.".
3. Line 4. Add the word "late" in front of "1981".
4. Line 5. Add the word "early" in front of "1985".
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COMMENTS
Page 2
3.
4.
G.
Item 2, Site History, 3rd paragraph.
1. Line 1. Change "the CTS" to "PRINTEX".
2. Line 2. Change "Chemicals (metals and volatile
organic compounds (VOCs»" to "Metals and Volatile
Organic Compounds (VOCs)". .
3. Line 3. Change "Two probable sources of these" to
"Two sources of metals and VOCs".
4. Line 4. Delete "Chemicals are" and substitute
"were". Add the , words "which was" after the word
"sump" . . .
5. Line 5. Change "Chemicals" to "Metals". Change,
"include copper, lead,. to "were copper and lead,".
TENTATIVE ORDER, PAGE 2.
A.
Item 2, site History, 3rd paragraph, Line 6.
Add the words "while VOCs detected were" in front of
"trichloroethene (TCE)".
Item 3, National Priority List "Superfund". Change
"CTS" to "PRINTEX" on lines 1 and 2.
Item 4, Administrative Orders and Permits.
1. Line 1. - Add the words "and permits" after
."administrative orders". .'
2. Line 2. Change "eTS" to "PRINTEX".
Item 5, Potentially Responsible Party.
1. Lin~,6. Change IICTS" to IIPRINTEX".
2. General comment. CTS has only reviewed a draft
PRP document dated December 15, 1989, which
identified Versatronex Corporation and Applied
Typographies Systems as former occupants of the
site. Did the final document clarify their PRP
status? Were previous owners (Anglo Energy, Inc.)
included? . ,
Item 7, Community Involvement, 1st paragraph, Line 2.
Change "CTS" to ."PRINTEX".
Item 7, community Involvement, 2nd paragraph, Line 8.
Question: Will the Responsiveness Summary be attached
and.made a part of the final Order? If so, it should be
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Item 8,' Summary of Site Characteristics, Hist~ry of Site
. Investi9ation, Line 2. Change "CTS former facility", to
"former Printex facility". '.
B.
C.
D.
E.
F.
G.
TENTATIVE ORDER, PAGE 3.
A.
Item 8, Summary of Site Characteristics, Hlstory of Site
Investiqation, Line 4. Delete "in late 1989".
,I,tem 9, Source Investigation, Line 1. Change "The
potential sources that were investigated are" to lithe
potential sources investigated were".
B.
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COMMENTS
Page 3
C. Item 9, Source Investigation. Line 4. Change "city*1 to
"City".
D. Item 9, Source Investigation. Line 13, Change
"pollution" to "contamination".
E. Item 10, Groundwater Investigation. 2nd paragraph.
1. Line 3. Change "Chemicals" *o "VOCs".
2. Line 10. Delete last sentence. The need for
additional monitoring wells has not been
demonstrated, thus should not be presupposed.
F. Item 11, Regional Hydroaeology. 3rd paragraph. Line 2.
Change "CTS" to "The former Printex Facility".
5. TENTATIVE ORDER, PAGE 4.
A. Item 11, Regional Hydrogeology. 2nd paragraph, Line~~4.
Change "CTS" to "former Printex".
B. Item 13, Other Source Investigation.
1. 1st paragraph, Line 2. Change "CTS" to "PRINTEX".
2. 2nd paragraph, Line 2. Same as above.
3. 4th paragraph. Change this paragraph to read
as follows:
"Further investigations may be needed to determine
whether CS is a source of chemical contamination
of groundwater. If CS is determined to be a
source, then the Board may order CS to determine
the extent of the release from its site. In that
eventf CTS' obligation under this Order may be
adjusted in accordance with Section B.
SPECIFICATIONS. Item .4. of this Order."
4. 5th paragraph, Line 2. Delete word "possibly".
5. 5th paragraph, Line 3. Change "CTS" to "PRINTEX".
6. TENTATIVE ORDER, PAGE 5.
A. Item 14. Summary of Site Risk. 1st paragraph, Line 4.
Delete "CTS".
B. Item 14, Summary of Site Risk. 4th paragraph. Add a
sentence to the end of the paragraph as follows:
"It is more likely that the source of toluene in air is
from activities other than those associated with the
former Printex site."
7. TENTATIVE ORDER, PAGE 6.
A. Item 15, Risk Characterization. 4th paragraph, Line 2.
Change "CTS" to "PRINTEX".
B. Item 16, Risk Characterization for each Pathway. 7th
paragraph, Line 4. Change "CTS" to "PRINTEX".
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,COMMENTS -
Page 4
-"_.
9.
10.
11.
12.
8.
TENTATIVE ORDER, PAGE 7.
A.
Item 19, Cleanup Alternatives, 3rd paragraph (Soil),
Line 1. Change "assume" to "assumes".,. "
Item 19, Cleanup Alternatives, 3rd paragraph,HLine 3.
Change "existing" to "exists".
Item 19, Cleanup Alternatives, 4th paragraph
(groundwater), Line 1. Delete "CTS".
B.
C.
TENTATIVE ORDER, PAGE 8.
A.
3rd paragraph, Line 3. - Insert the word "be" so that the
sentence reads, "The extraction element of'the alterna-
tive is assumed to I2e. the existing system."
TENTATIVE ORDER, PAGE 9.
A.
Item 22, Final Cleanup Plan, paragraph d. Long-term
monitoring. The approximated time frame for long-term
monitoring offered in this paragraph is disputedly too
long, but CTS doesn't believe it prudent to offer any
approximation at this time anyway, thus, asks that the
phrase "(for approximately 15 year&)~ be removed.
Additionally, to correlate with commen~s provided for
page 14 of the TENTATIVE ORDER, CTS requests that the
, term "may" be substituted for the term "will".
TENTATIVE ORDER, PAGE 10.
Item 23, Summary of Evaluation Criteria for the
Alternatives.
1. Alternative 2: Institutional Action. Change
"CTS" to "PRINTEX".
2. Alternative 3: Extraction~reatment/Discharge.
Change "BASIS FOR ACCPTANCE" to "BASIS FOR
ACC£PTANCE" .
3. Alternative 3: ,Extraction/Treatment/Discharge.
Paragraph on Implementability, Line 2. 'Change
"CTS" to "PRINTEX"., ' '
4. Alternative 3: Extraction/Treatment/Discharge.
Paragraph on Cost', Line 3 . Change "$398,000" to
"$466,000" and change "$852,000" ~o "$725,000".
TENTATIVE ORDER, PAGE 11.
A.
A.
B.
Item 23, last sentence. Change "consider" to
"considered". '
Item 24, Cleanup Standards, 2nd paragraph, Line S.
Delete "the" prior to "CTS".
Item 24, 2nd paragraph, Line 7. Change "impracticable"
to "impractical".
C.
fII.
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COMMENTS
Page 5
D. Item 25, Evaluation of Final Plan. Line 2. Delete
"by the CTS".
13. TENTATIVE ORDER, PAGE 12.
A. Item 27, Future Changes to Cleanup Standards. Last
paragraph. As a general comment, CTS is discouraged
by the lack of finality to the cleanup agreement, and
the inability of the board to commit to a final
document. However, based on the abundance of data and
known technical facts related to this site, CTS is
confident of the measures taken to define and remediate
the release associated with the former Printex site, and
does not believe the measure contemplated by this
paragraph will ever require implementation. However^ it
is suggested that Line 5 be re-worded as follows:
..."previously described herein unless: (1)
conditions on the site, recently discovered by the
Board and directly related to the activities of
Printex. are discovered"...
B. Item 29, Lead Agency. Line 8. Last word is "thereunder"
(one word in lieu of 2).
C. Item 33, Line 1. Change "CTS" to "PRINTEX".
14. TENTATIVE ORDER, PAGE 13.
A. Item 37, Line 2. Change "sate" to "state".
15. TENTATIVE ORDER, PAGE 14.
A. B.SPECIFICATIONS. Item 2, Line 4. Change "pollutant"
to "contaminant".
B. B.SPECIFICATIONS. Item 3. Change "CTS" to "PRINTEX".
C. B.SPECIFICATIONS. Item 4. Revise the first sentence to
read as follows: "Final cleanup standards for all
onsite and off-site wells shall not be greater than the
levels as provided in Finding 22, unless the discharger
can demonstrate that the cause of its inability to
attain final cleanup standards is created by a contain!- •
nant source(s) other than the former Printex facility.
In that event, this Order will then be. modified to
increase the levels of cleanup standards for the
affected discharger and the Board may take all other
appropriate actions against the additional discharger(s)
including an Order compelling said discharger to assume
responsibility for all further contaminant cleanup
and long-term monitoring."
D. c.PROVISIONS. Item 2, Lines 3 and 4. Change "The
primarily responsible discharger" to "CTS Corporation".
E. c.PROVISIONS. Item 2.b. Task 2, Line 7. Revise the last
sentence to read as follows: "The report shall also
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COMMENTS
Page 6
evaluate the effects of operation of existing extraction
veils on groundwater levels and effectiveness of the
well cycling program to avoid creating stagnation zones,
and determine if monitoring vell(s) should be added or
deleted.
16. TENTATIVE ORDER,, PAGE 15.
A. c.PROVISIONS. Item 2.c. Task 3.
1. Line 2. Remove the word "additional**.
2. Line 8. Remove the words "polluted soil".
3. Line 10. Remove the words "and/or soil
remediation".
B. c.PROVISIONS, item 2.e., last line. Change finding
"21" to "20".
C. c.PROVISIONS. Item 2.f. Task 6, Line 5. End the —
sentence following the words "drinking water".
D. C.PROVISIONS. Item 2.g. Change completion date from
August 15, 1990 to August 15, 1991.
17. TENTATIVE ORDER, PAGE 16.
A. C.PROVISIONS. Item 2.g. Task 8, Line 3. Change "39W" to
"34W". Also, delete the word "possible".
B. c.PROVISIONS. Item 5, 1st paragraph. Delete the last
sentence. CTS is neither privy to that information, nor
is it necessary to determine adequacy of remediation
efforts.
C. c.PROVISIONS. Item 5, 2nd paragraph, Line 2. The
sentence starting on line 2 requests information that
would be more meaningful if reported on an annual,
rather than a quarterly, basis. The information
requested will not significantly change from one quarter
to the next, but places an extensive reporting burden
upon CTS for which there is little justification. CTS
requests that the requirement be moved to C.PROVISIONS.
Item 6.
D. C.PROVISIONS. Item 6. For consistency with the self-
monitoring program, the annual report is to be combined
with the fourth quarter report. Thus, Item 6 should be
revised as follows: "On an annual basis, or as required
by the Executive Officer, the status report shall
include, but need not be limited to, an evaluation of
the cleanup measures. A summary of monitoring and
sampling data shall also be included in the annual
report. For purposes of reporting, the annual report
shall be combined with the fourth quarter report."
E. C.PROVISIONS. Item 7. Resubmission of reports already
found acceptable to the Executive Officer should not be
necessary. Delete.
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COMMENTS
Page 7
c.PROVISIONS, items 12, 13, and 14. It should be noted
that these items are largely site-based requirements,
and are not within the control of CTS. However, CTS
will advise ADN Corporation of the requirements
applicable to the site.
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LE'ITER OF TRANSMItTAL
Date:
April 19, 1991
To: .
Mr. Steven Ritchie
Executive Director.
San Francisco Bay Region
California RegioDaJ Water QuaJity CoDtrol Board'
2101 Webster, 4th Aoor
Oakland. CA 94612
From:
Terrance E. Carter
Project Manager
~
Subject:
ResponR to Comments
Former crs Printo Facility
Mountain Vi~'. CA
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Transmitted hereWith are copies of the response 10 comments from the Regional Water Quality
Control Plant - PaJo Alto letter'dated March 28, 1991. .
Please note that new policy issued by PaJo Alto requires that, at the time of permit renewal.
crs must document options for water reuse. This requirement paralJels SccUon C .
PROVISIONS, 2. a. of the Tentative Board Order for Printex. Since the permit renewal ~iJl'
occur in January, 1992. and the RWQCB requirement is tentatively scheduled for October,
1991, OD behalf of crs Corporation, we res~ly request the requirement for this
documentation specified in the order be changed to January, 1992.
cc:
Tom Bcnz, RWQCB
John F. Nolan, Sheppard, Mullin, Richter & Hampton
Phil Bobe~ Palo Alto Treatment Plant
Russ Fraur, City of Mountain View
Marv Gobles., crs Corporation
Scan Hogan, EPA
, Walter Baum, California DHS
Thomas I. Iwamura. SCVWD
408.1.1W1/SR)41791.TRH
-------
ITT
RESPONSE TO COMMENTS
April 19,1991
Comments were received from the Palo Alto Regional Water Quality Control Plant during the
response period in reference to the Proposed Cleanup Plan for the former CTS Prim ex site.
PALO ALTO REGIONAL WATER QUALITY CONTROL PLANT - LETTER DATED
MARCH 28,1991
Comment 1: Treatment of VOCs at the City of Mountain View Sewage Treatment Facility.
_ * -•
Response: Volatization of VOCs in water discharged to the sanitary sewer system from the
former Printex facility is the primary mechanism for 'treatment*. Accordingly, ATT concurs
with the comment that VOCs are not treated" at the sewage treatment plant since a substantial
portion of the VOCs discharged to the sewage treatment plant volatize prior to reaching thc-
plant and a minimal portion volatize at the plant.
Sections 6.5,6.6 and Tables 12 of the Baseline Public Health Evaluation (BPHE) provide an
evaluation of risk to human receptors associated with inhalation (by volalization) and dermal -
exposure to the VOCs in groundwater. .Noncarcinogenic effects based on possible exposure
were less than one (Hazard Index < 1) and would not be expected to have a significant impact
to human receptors. -Carcinogenic risks based on possible exposure of VOCs by inhalation and
dermal contact for workers (risk = 6.6e ) is well below the risk level for workers (l.Oe"-5).
Comment j: Requirement demonstrating water reuse options.
Response: Section C. PROVISIONS. 2, a. of the Tentative Site Requirements for the CTS
Corporation issued by the RWQCB, requires parallel documentation of efforts to reuse
extracted groundwater. The requirement will be addressed in January, 1992, at the time of
renewal of the discharge permits. '
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
HCOIONIX
76 Hawthorn* SttMt
ft«n Fr«ncl»co, Ct. t410S
April 17, 1991
MEMORANDUM
TOt Ton Bone, PWQCD Project Manager
FROM: Sean P. Hogan, EPA Project Manager
SUBJECT: Transroittal or EPA comments on the Draft Tentative
Order for CTS Corporation and ADN corporation, Mountain
viaw, California
Contained in this memo are EPA's comments on the Draft Tentative
Order for CTS Corporation and ADN.Corporation in: Mountain View,
California. The comments contained in this memo are mostly con-
cerned with the definition of the contaminant plume emanating
from the former CTS facility and the selected alternative for
toil remediation.
If you have ar.y questions regarding the comments in this memo,
please contact me at (415) 744-2233. ThanX you.
COMMENTS
Pace 2. Finding 5!
Carl Sox is identified as a potentially responsible party (PRP)
due to being a potential source of contamination. However,
Castro Faint, who is still considered a potential source in Find-
ing 13, is not identified as a PRP. Please explain why Castro
Paint is not identified as a PRP.
Page 3. Finding- 9:
EPA suggests that the source control measures described in this
finding'are discussed in a separate finding ..called "Interim
Actions." The discussion regarding soil excavation and sump
removal should also state what the cleanup levels were for the
excavation. Interim actions addressing groundwater contamination
would r.lso be discussed under this finding.
Rttrcim
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04/18."'31
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Paae 3. Findino 10:
. .
,. .;11
'Th'1. di8cussion should Inclu~e some narrative' description of the
lateral and vertical extent of the plume boundaries. Also, 1t is
unclear it the RWQCB has established that the contamination dis-
covered in well 3$W 18 att.r1buted to a separate plume or a plume
that has merged with the plume emanating trom,the former CTS
facility. If there 15 a d.fin.~ ..paration ~.tw..n the two
plumes, the known boundaries cf ~he adjacent plume should be
described. An illustration may be appropr.iate ~~ eliminate con-
fusion.
PaC1'e S.
Finding 14:
Are the contaminants identified as "chemicals or concern" repre-
sentat1veot all che~icals in the aguifer with respective State
or federal cleanup standards? It the listed chemicals ot concern
do not represent ell of the contaminants present with assigned
cleanup levels, EPA suggests that Table 1 1s supplemented with
the additional chemicals and their respective cleanup lev~ls.
For completeness, the discussion,reqordin; toxicity assessment of
ccnta~inants shoul~ 4escr1be what are acceptable risk l~vels tor
no.1C'.arcinogens.
peae 5, Findin9 15:
~: .
I .;Jf,:;,,;es
The last sentenQe on this page 18 unclear: "Stuc1ies ot the area
hava concludea that acute and chronic toxicity values for agu~ti~
..:>rganisnls are. greater than cuxren't or pred1:cted. concentration& of
volatile or9an1c compounds in Permanente Creek and the southern
portion ,:,t San Francisco Bay.1t I» th!» 90o~ or bad?
Peae U, Fin~.ing.."G.i.
!sdischarge to the sanitary sewer considered a potentially sig-
nificant exposure pa~hwcy?
In the second paragraph under "Future Cttrcinogen!c Risks," please
define wh~'t other exposure pathways were considered for the car-
cinogenic risk calculation. '
Pao. 9. Fi~dinQ ~2:
It is unclear how an alternative could be '.selected for' so.1l when
~'in(Un9 17 states thatremecUal alternatives ~ere not developed
for soil due to ~h. 1nalgniticant risks. Although the no action
alterna~ive 1. selected tor the 50115, maybe it would be more
clear if the text used tor Finding 17 is also used tor Finding
22. '
Will san1pling ot Permanente Cree]~ be required as part ot th-::
lon9-term monitoring plan? Please include more ~etD11 about the
long-term ~onitoring plan or reference another source. '
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Pace 10. Finding 23;
It is stated that "costs associated with yroundwater extraction
facilities have already been incurred by CTS Corporation in im-
plementing current remedial actions at the site.*' DO the eostB
provided in the order-include the incurred coats? EPA requires
that all costs, past, present, and future, must be considered for
the comparison anaysis.
p.:-.7a 11. Finding 24 •
it is stated that groundwater extraction shall continue as long
as significant quantities of chemicals are being removed through
groundwater extraction. Please define "significant quantities."
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Sonfo vfaroNfaBey Water District
April 19, 1991
5750 ALMADEN EXPRESSWAY
SAN JOSE. CALIFORNIA 95116
TELEPHONE (408) 265-2600
FACSIMILE (408) 266-0271
AM AFHRMWIVE
REGIONAL WA73?
Mr. Tom Be
Regional Water Quality Control Board
2101 Webster Street, Suite 500
Oakland, CA 94612
Dear Mr. Benz:
« r'r§ .
r\ > • •-., I.* 01
QUALITY CONTROL BOARD
Subject: Comments on CTS Printex Site located at 1911 Plymouth Street, Mountain View
We are in general concurrence with your cleanup plans for the CTS Printex site located at 1911 Plymouth
Street, Mountain View, California.
On page 5 of the March 1991, Fact Sheet No. 2, under "Regional Board Cleanup Standards for the CTS
Printex Site," it is stated that the shallow groundwater zones affected by the contamination at the Printex
site are currently not used as a water supply and local ordinances prohibit such practice. We would like
to clarify this statement in reference to the prohibition. In this area where the local-ordinances outline
an area of upper aquifer zone and lower aquifer zone, the ordinance does not prohibit the construction
of wells in either zone.
In the two aquifer zone the upper zone aquifers are those that occur at depths less than 100 feet and the
lower zone aquifers are those that occur at depths greater than 150 feet.
Any water supply well constructed in the upper aquifer zone would require a sanitary seal that extends
to a minimum depth of 50 feet and ending at least 5 feet into a significant aquitard. As the two
uppermost contaminated aquifers at the she occur at depths less than 50 feet, the local ordinances require
that these contaminated aquifers be sealed off. This does not preclude that upper aquifer zone aquifers
deeper than 50 feet cannot be used-as a source of supply, providing that such a well does not tap both
the upper and lower zone aquifers. Any well constructed to tap the lower aquifer zone in the two aquifer
zone will require a sanitary seal extending to a minimum depth of 150 feet (through the major aquitard).
Please call Tom Iwamura or myself if you have any question.
Sincerely,
Mpcereiy, / . / /
/ ' •' /
V •//'/./
David J* Gftesternian
Supervising Engineer
Groundwater Protection Division
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