United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R09-90/052
September 1990
Superfund
Record of Decision
Intersil, CA
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R09-90/052
3. Recipient's Accession No.
4. Title and Subtitle
S'UPERFUND RECORD OF DECISION
Intersil, CA
First Remedial Action - Final
5. Report Date
. 09/27/90
7. Auttior(s)
8. Performing Organization RepL No.
9. Performing Organization Name and Address
10. Project/Task/Work Unit No.
11. ContractfC) or Grant(G) No.
(C)
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/000
IS. Supplementary Notes
16. Abstract (Limit: 200 words)
The 12-acre Intersil site contains two industrial properties, Intersil, Inc., and
Siemens Components, Inc., in Cupertino, California. Since 1978, Siemens has
manufactured semiconductor products for optoelectronic applications at the site. Former
underground waste-handling facilities, which have been removed, included five unvaulted
waste solvent tanks and an unvaulted acid dilution basin. Solvents are currently stored
above-ground and wastewater is treated in an acid neutralization system. From 1967 to
1988, Intersil operated as a semiconductor assembly facility. Two vaulted and one
unvaulted underground acid neutralization systems, now excavated, were used in the
operation. Both facilities used various organic solvents and commercial mixtures.
Contamination, a result of releases from the underground waste handling facilities at
both plants, has been detected in soil and ground water beneath the site. A contaminant
plume also has been detected, which affects offsite ground water. In 1983, Siemens
began onsite soil vapor extraction, and subsequently in 1986, began pumping and
treatment of onsite ground water. Intersil began onsite ground water treatment and soil
vapor extraction in 1987. This Record of Decision (ROD) outlines the final remedy
addressing onsite source areas, and onsite and offsite contaminated ground water. The
(See Attached Page)
17. Document Analysis a. Descriptor*
Record of Decision - Intersil, CA
First Remedial Action - Final
Contaminated Media: soil, gw
Key Contaminants: VOCs (PCE, TCE, toluene), other organics (phenols)
b. Identifiers/Open-Ended Terms
c. COSAT1 Field/Group
18. Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Page)
None
21. No. of Pages
107
22. Price
(See ANS4-Z39.18)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R09-90/052
Intersil, CA
First Remedial Action - Final
Abstract (Continued)
primary contaminants of concern affecting the soil and ground water are VOCs including
PCE, TCE, and toluene; and other organics including phenols.
The selected remedial action for this site includes enhancement and/or expansion of
onsite and offsite ground water pumping and treatment systems, which use air stripping,
and the soil vapor extraction systems, which use carbon adsorption at the Siemens and
Intersil facilities; excavating 40 cubic yards of soil contaminated with greater than
10 mg/kg semi-volatile organics at the Siemens facility, followed by offsite disposal;
pumping and treatment of offsite ground water using air stripping; discharging all
treated ground water to onsite surface water; and monitoring soil vapor and ground
water. The estimated present worth cost for this remedial action is $18,750,000. O&M
costs were not provided.
PERFORMANCE STANDARDS OR GOALS: Ground water cleanup standards were chosen as the more
stringent of Federal or State MCLs, or State Recommended Drinking Water Action Levels
(RDWALs) . Chemical-specific goals include PCE 5 ug/1 (State MCL), TCE 5 ug/1 (State
MCL), and toluene 100 ug/1 (RDWAL) . Soil cleanup goals have been set at 1 mg/kg total
VOCs for vapor extraction, and 10 mg/kg total semi-volatile organics (including phenols)
for soil excavation and offsite disposal.
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• It !.'«.
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 9
1235 MISSION STREET
SAN FRANCISCO, CA 94103
RECORD OF DECISION
DECLARATION STATEMENT
SITE NAME AND LOCATION
Intersil/Siemens Superfund Site
Cupertino, California
STATEMENT OF BASIS AND PURPOSE
This declaration document presents the selected remedial action
for the Intersil/Siemens site located in Cupertino, California,
which was chosen in accordance with the Comprehensive Environmen-
tal Response, Compensation and Liability Act of 1980, 42 U.S.C.
Section 9601, .as amended by the Superfund Amendments and
Reauthorization Act of 1986, (CERCLA), and the National Oil and
Hazardous Substances Pollution Contingency Plan, 40 C.F.R. Part.
300, 55 Fed. Reg. 8666 (NCP). This decision is based on the ad-
ministrative record for this site.
The State of California concurs with the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this
site, if not addressed by implementing the response action
selected in this Record of Decision (ROD), may present an im-
minent and substantial endangerment to public health, welfare, or
the environment.
DESCRIPTION OF THE SELECTED REMEDY
The selected remedy for the Intersil/Siemens site addresses the
principal threats posed by the site, ground water and soil con-
tamination. The primary chemicals of concern include
1,1-dichloroethene (1,1-DCE); trichloroethene (TCE);
tetrachloroethene (PCE); 1,1,1-trichloroethane (1,1,1-TCA); freon
113; and toluene.
Several interim response actions were performed at the site by
Intersil and Siemens. This action represents the final remedial
action to remove contaminants from ground water and soil. The
major components of the selected remedy are:
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o Excavation of an estimated 40 cu. yds. of soil from the
Siemens on-site area. The soil will be disposed of in compliance
with RCRA land disposal restrictions.
o Operation of 23 soil vapor extraction wells (15 wells in the
Siemens on-site area and 8 in the Intersil on-site area) with
treatment by carbon adsoprtion.
o Operation of 20 ground water extraction wells (13 wells in
the Siemens on-site area and 7 wells in the Intersil on-site
area). Extracted ground water will be treated by air stripping
and discharged to Calabazas Creek under an NPDES permit.
o Operation of three ground water extraction wells in the
off-site area. Extracted ground water will be treated by air
stripping and discharged to Calabazas Creek under an NPDES per-
mit.
o Continued monitoring of ground water and soil to verify con-
tainment of the contaminated' ground water and attainment of
cleanup levels.
. ,s,
STATUTORY DETERMINATIONS
Promulgated maximum contaminant level goals (MCLGs) serve as the
ground water cleanup standards for those chemicals of concern
with MCLGs greater than zero. MCLGs are the ground water cleanup
standards for two chemicals of concern at Intersil/Siemens: 1,1-
DCE and 1,1,1-TCA. In these two instances, the California Action
Level (AL) or federal or state maximum contaminant level (MCL)
that has been chosen as the cleanup standard is either equivalent
to or more stringent than the federal MCLG.
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 technologies or resource
recovery technologies to the maximum extent practicable for this
site, and satisfies the statutory preference for selecting
remedies that employ treatment that reduces the toxicity,
mobility, or volume of the hazardous substances. A review of the
remedial action will be conducted every five years, after com-
mencement to ensure that the remedy continues to provide protec-
tion of human health and the environment.
Date -, ^-Daniel W. McGovern
Regional Administrator
EPA Region IX
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Table of Contents
Declaration
Decision Summary
I. Site Description 1
II. Site History and Enforcement Activities 1
III. Community Participation Activities 1
IV. Scope and Role of Response Action 2
V. Summary of Site Characteristics 2
VI. Summary of Site Risks 3
VII. Summary of Alternatives 3
VIII. Comparison of Alternatives 4
IX. The Selected Remedy 4
X. Statutory Determinations 7
Responsiveness Summary
Appendices
A. RWQCB Site Cleanup Requirements
B. Correspondence
C. Maps
D. Administrative Record Index
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 9
1235 MISSION STREET
SAN FRANCISCO, CA 94103
DECISION SUMMARY
The U.S. Environmental Protection Agency ("EPA") and the
California Regional Water Quality Control Board, San Francisco
Bay Region ("Regional Board"), have worked together to select the
remedy for the Intersil/Siemens site. Consequently, portions of
the documents by which the Regional Board has embodied its
selection of the remedy under State law reflect the efforts of
both agencies to investigate the site, to assess the risks which
it poses, and to evaluate and compare possible remedial
alternatives. Particularly, certain portions of Order No. 90-119
which was adopted by the Regional Board on August 15, 1990,
referred to hereafter as the "Order," accurately set forth the
views and rationale of EPA. Consequently, this Decision Summary
will refer to portions of those documents (both are attached),
and by such reference they are thereby deemed to be incorporated
into this Decision Summary.
I. SITE DESCRIPTION
Finding 1 of the Order describes the Intersil/Siemens site.
Regional and site maps are found in Appendix C of this Record of
Decision ("ROD"). Residential neighborhoods are within a few
hundred feet north and south of the site, and an orchard is
approximately 2000 feet to the east. There are five active
monitoring wells within a one-mile radius of the site, three of
them downgradient.
II. SITE HISTORY AND ENFORCEMENT ACTIVITIES
Findings 3, 4, 11 and 25 of the Order provide a history of site
activities and state and federal enforcement activities at the
Intersil/Siemens site.
III. COMMUNITY PARTICIPATION ACTIVITIES
Finding 22 of the Order describes how the public participation
requirements of CERCLA Sections 113 and 117 were met in the
remedy selection process. A response to comments received during
the public comment period is included in the Responsiveness
Summary, which is part of this Record of Decision ("ROD").
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IV. SCOPE AND ROLE OF RESPONSE ACTION
The selected remedy addresses the principal threats posed by the
site, ground water and soil contamination for the Siemens on-site
area, the Intersil on-site area, and the off-site area. Finding
11 of the Order describes interim remedial actions at the site
and evaluates their effectiveness in removing and treating
contaminated ground water and in reducing contaminant migration
to ground water by means of vapor extraction and treatment of
contaminated soils. The selected remedy will address ground
water contamination in the A- and B- zones on-site and in the B-
and C-zones off-site. Contaminants removed from both soil and
ground water will be captured and permanently destroyed,
significantly reducing the toxicity, mobility or volume of the
hazardous substances in both media.
VI. SUMMARY OF SITE CHARACTERISTICS
Findings 5 through 10 of the Order describe site hydrogeological
conditions and the nature and extent of organic chemical
contamination in soil and ground water at the Intersil/Siemens
site.
VII. SUMMARY OF SITE RISKS
EPA policy and guidance require that the potential risk to human
health and the environment be evaluated under a No-Action
scenario. This scenario assumes unrestricted access to site
contaminants (including soils and ground water) and assumes that
all on-going treatment and/or mitigation measures are terminated
immediately. The information provided by the baseline risk
assessment is then used to characterize the current and potential
threats posed by the site to human health and the environment.
No exposure pathways with an excess cancer risk number (ECRN)
greater than the 10~4 to 10~6 range or a non-carcinogenic hazard
index (HI) greater than 1 were identified under current site
conditions. Table 1 presents on-site and off-site pathway
exposures under future use scenarios.
Finding 12 of the Order summarizes the results of the baseline
risk assessment. This section also discusses the assumptions
used in the exposure assessment.
No critical habitats or endangered species were identified for
the Intersil/Siemens site. The potential for migration of
contaminants via surface runoff to Calabazas Creek is minimal.
Treated ground water from the on-site treatment units is
discharged to the creek as regulated by NPDES permit. The
potential for future ecological impacts at this site is
determined to be low.
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VII. SUMMARY OF ALTERNATIVES
In accordance with CERCLA Section 121, the National Contingency
Plan ("NCP"), and the Interim Guidance on the Superfund Selection
of Remedy, December 24, 1986 (OSWER Directive 9355.0-10), a range
of soil and ground water remediation options for the
Intersil/Siemens site was developed and initially screened on the
basis of effectiveness, implementability and relative cost.
Next, a detailed analysis of the remaining alternatives in
relation to nine evaluation criteria was conducted. Finding 14
of the Order identifies the nine evaluation criteria and Finding
13 provides a description of the proposed alternatives.
Although the Intersil and Siemens facilities are listed as one
site on the National Priorities List, each company completed its
own RI/FS and jointly completed an off-site RI/FS. For this
reason, a separate series of alternatives was developed for the
Siemens on-site, Intersil on-site, and off-site areas. The
alternatives for each and their associated costs are as follows:
Siemens On-Site Alternatives
1) No action $2,880,000
2) Ground water extraction/treatment
(9 wells) and soil vapor extraction/
treatment (15 wells) 4,870,000
3) Ground water extraction/treatment
(13 wells) and soil vapor extraction/
treatment (15 wells) 5,030,000
4) Same as #3 with soil excavation and
disposal of approximately 40 cu. yds.
of soil 5,660,000
5) Same as #4 with 7 additional soil
vapor extraction wells 6,360,000
Intersil On-Site Alternatives
1) No action $ 4,000,000
2) Existing ground water extraction/
treatment (5 wells) and soil vapor
extraction/treatment (4 wells) 9,800,000
3) Ground water extraction/treatment
(7 wells) and soil vapor extraction/
treatment (12 wells) 10,100,000
4) Same as #3 with on-site reinjection
of treated ground water 10,700,000
5) Same as #2 with the addition of on-site
ground water reinjection, soil excavation
and on-site aeration, and a slurry wall 37,300,000
6) Same as #3 with more stringent ground
water cleanup to VOC background levels 10,600,000
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Off-Site Alternatives
1) No action $1,220,000
2) Ground water extraction/treatment from
one B-zone well ' 2,120,000
3) Ground water extraction/treatment from
three B-zone extraction wells with
contingency for one C-zone well 2,990,000
4) Ground water extraction/treatment from
two B-zone and one C-zone wells 2,650,000
5) Ground water extraction/treatment from
two B-zone and two C-zon^wellisfs^fe'iw-, . 2,810,000
6) Same as #5 with more stringent ground
water cleanup to VOC background levels 2,960,000
All of the alternatives, except the no action alternatives,
include continuing shallow zone and deeper aquifer ground water
and soil monitoring. For all of the treatment alternatives,
except the no action alternatives, ground water is treated by air
stripping with subsequent discharge to Calabazas Creek under
NPDES permit. Soil vapor treatment is by carbon adsorption.
VIII. COMPARISON OF ALTERNATIVES
This portion of the ROD presents a comparison of the alternatives
using the nine evaluation criteria: protection of human health
and the environment; compliance with applicable or relevant and
appropriate requirements ("ARARs"); long-term effectiveness and
permanence; reduction of toxicity, mobility or volume through
treatment; short-term effectiveness; implementability; cost;
support agency acceptance; and community acceptance.
Although the proposed alternatives for each of the three areas
are presented separately, they are comparable in that they
represent variations of similar basic treatment elements.
However, because the RI/FS reports were prepared separately, the
alternatives have been evaluated separately. Table 2 (Siemens
on-site), Table 3 (Intersil on-site) and Table 4 (Off-site)
summarize the results of the detailed analysis of alternatives.
IX. THE SELECTED REMEDY
In general terns, the selected remedy for the entire
Intersil/Siemens on-site and off-site areas consists of:
o Soil vapor extraction and treatment for soil cleanup
(with soil excavation and disposal at the Siemens on-site
area)
o Ground water extraction and treatment for ground water
cleanup
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o Shallow zone and deeper aquifer ground water monitoring
and soil monitoring
Specifically, the selected remedy for each area at the site is as
follows:
Siemens On-Site Area: The selected remedy for the Siemens
on-site area is Alternative 4, which consists of expanded ground
water extraction and treatment, soil vapor extraction and
treatment, and soil excavation. There will be a total of ten
A-zone and three B-zone ground water extraction wells. There
will be a total of 15 soil vapor extraction wells. The selected
remedy also includes excavation of approximately 40 cu. yds. of
contaminated soil to a depth of approximately 40 feet in the
areas of former tanks 1 and 3 to remove soils containing
semi-volatile organic compounds (SOCs). The soil will be
disposed of in compliance with RCRA Land Disposal Restrictions
(LDRs). The estimated time to achieve ground water cleanup is
45 - 85 years; the estimated time to achieve soil cleanup is
approximately 11 years.
Intersil On-Site Area: The selected remedy for the Intersil
on-site area is Alternative 3, which consists of expanded ground
water extraction and treatment in the A- and B-Zone and expanded
soil vapor extraction and treatment. There will be a total of
ten A-zone and one B-zone ground water extraction wells and eight
soil vapor extraction wells. The estimated time to achieve
ground water cleanup is 60 years; the estimated time to achieve
soil cleanup is five years.
Off-site Area: The selected remedy for the Intersil/Siemens
off-site area is Alternative 3, which consists of ground water
extraction from three B-zone extraction wells and treatment.
C-zone ground water will be captured by pumping of the B-zone
wells. If C-zone VOC concentrations do not show a reduction
during the first one-year period and/or sufficient C-zone capture
is not demonstrated, a C-zone monitoring well will be converted
into a C-zone extraction well. The estimated time to achieve
ground water clean up is 20 - 45 years.
For the three areas, ground water treatment will be accomplished
by air stripping with subsequent discharge to Calabazas Creek
under NPDES permit. For the Siemens on-site area and the
off-site area, there may be partial reuse and reclamation of
treated water. Soil vapor treatment will be accomplished through
carbon adsorption. Regular ground water and soil vapor
monitoring will be conducted.
The selected remedy for each area is described in more detail in
Finding 15.1 - 15.3 of the Order.
The goal of this remedial action is to restore ground water to
its beneficial use. Based on the information obtained during the
remedial investigation and on a careful analysis of all remedial
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alternatives, EPA and the State of California believe that the
selected remedy will achieve this goal. It may become apparent,
during implementation or operation of the ground water extraction
system and its modifications, that contaminant levels have ceased
to decline and are remaining constant at levels higher than the
remediation goal over some portion of the contaminated plume. In
such a case, the system performance standards and/or the remedy
may be reevaluated.
The performance of the ground water extraction and treatment
system will be carefully monitored on a regular basis and
adjusted as warranted by the performance data collected during
operation. Modifications may include:
a) at individual wells where cleanup standards have been
attained, pumping may be discontinued;
b) alternative pumping at wells to eliminate stagnation
points;
c) pulse pumping to allow aquifer equilibration and to
allow adsorbed contaminants to partition into ground
water; and
d) installation of additional extraction wells to
facilitate or accelerate cleanup of the contaminant
"" plume.
ARARs
Chemical-, location-, and action-specific ARARs identified for
the Intersil/Siemens site include:
Federal: Safe Drinking Water Act, Clean Air Act, RCRA (Land
Disposal Restrictions), Clean Water Act
State: Porter Cologne Water Quality Act, Safe Drinking Water
Act, Clean Air Act, California Hazardous Waste Control Law, State
Board Resolution 68-16, State Board Resolution 88-63 as
incorporated in the Water Quality Control Plan for San Francisco
Basin Plan
Local: Bay Air Air Quality Management District (BAAQMD)
Regulation 8, Rule 47 ("Air Stripper and Soil Vapor Extraction
Operations") and BAAQMD Regulation 8, Rule 40 ("Aeration of
Contaminated Soil and Removal of Underground Storage Tanks")
TBCs for the Intersil/Siemens site include OSWER Directive
9355.0-28 ("Control of Air Emissions from Superfund Air Strippers
at Superfund Groundwater Sites").
Cleanup Standards
Findings 15.1 - 15.3 and 18 of the Order include a discussion of
cleanup standards for each area. For each, ground water cleanup
standards are federal or state Maximum Contaminant Levels (MCLs)
or California Department of Health Services (DHS) Recommended
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Drinking Water Action Levels (RDWALs). Specification B.4 of the
Order presents ground water cleanup standards for all chemicals
of concern at the Intersil/Siemens site.
Promulgated MCLGs serve as the ground water cleanup standards for
those chemicals of concern with MCLGs greater than zero. MCLGs
are the ground water cleanup standards for two chemicals of
concern at the Intersil/Siemens site: 1,1-dichloroethene
(1,1-DCE) and 1,1,1-trichloroethane (1,1,1-TCA). In these two
instances, the California RDWAL or federal or state MCL that has
been chosen as the cleanup standard is either equivalent to or
more stringent than the federal MCLG. A conservative remediation
standard of 1 ppm total VOCs and 10 ppm total SOCs has been set
for soil contamination.
STATUTORY DETERMINATIONS
In accordance with CERCLA Section 121, the selected remedial
action for each area at the Intersil/Siemens site is protective
of human health and the environment, complies with ARARs, is cost
effective, and utilizes permanent solutions and alternative
treatment technologies or resource recovery technologies to the
maximum extent possible. In addition, the selected remedies
satisfy the statutory preference for remedies employing treatment
that reduces toxicity, mobility or volume as a principal element.
Under each area's chosen remedy, future risks at the site fall
within the 10~4 to 10~6 carcinogenic risk range and the
less-than-one Hazard Index for all exposure pathways. On-site
soil will be remediated to a level that will protect on-site and
off-site ground water from further contamination by chemicals
presently in the soils. The selected remedies comply with
federal and state ARARs. Both soil vapor extraction and air
stripper emissions will meet the requirements of the BAAQMD
Regulation 8, Rule 47 and OSWER Directive 9355.0-28.
Implementation of the remedies will cause no unacceptable
short-term risks or cross-media impacts.
Treatment is used as a principal element for the selected
remedies. Soil vapor extraction and treatment and ground water
extraction and treatment are permanent solutions and
significantly reduce contaminant toxicity, mobility and volume at
the site. The selected remedial actions are the most
cost-effective. Although the selected remedies' times to reach
cleanup are not the shortest, they do avoid short-term risks
associated with the shorter cleanup time alternatives.
Finding 16 of the Order provides an explanation of how the
selected remedies satisfy each of the statutory requirements.
Finding 19 of the Order specifically addresses how the selected
remedies protect the public health.
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Land Disposal Restrictions
CERCLA response actions must comply with RCRA Land Disposal
Restrictions (LDRs) when they are determined to be ARARs.
Current EPA guidance directs that LDRs are not relevant and
appropriate for soil and debris wastes at this time. In order
for RCRA LDRs to be applicable to soil and debris wastes, the
CERCLA response action must constitute placement of a restricted
RCRA hazardous waste.
The selected remedy for the Siemens on-site area soil includes
excavation of a total of approximately 40 cu. yds. of soil from
two separate locations, the sites of former tanks 1 and 3. The
remedial investigation identified two SOCs at concentrations
greater than 10 ppm (1,2,4-trichlprobenzene (1,2,4-TCB) and
phenol) at the two former tank locations. Although soil vapor
extraction with treatment by carbon adsorption will be performed
at these two locations, SOCs are not readily amenable to
treatment by this method. Soil vapor extraction is expected to
reduce concentrations to the soil VOC cleanup standard of l ppm,
but is not expected to reduce SOC concentrations to the soil SOC
cleanup standard of 10 ppm.
Neither 1,2,4-TCB nor phenol are listed or characteristic RCRA
hazardous wastes. However, the soil that will be excavated and
disposed contains spent solvents (e.g., xylenes), which are
restricted RCRA hazardous wastes. As such, they would be subject
to LDRs and would have to meet treatment standards (effective
date November 8, 1990) before the soil could be excavated and
disposed of off-site. (Metals in the soil were also determined
to be neither listed nor characteristic RCRA hazardous wastes).
The soil VOC cleanup standard of 1 ppm will reduce concentrations
well below required LDR treatment standards. If these VOC
cleanup standards cannot be met, it will be necessary to obtain a
Soil and Debris Treatability Variance in order to comply with
LDRs.
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TABLE 1
SUMMARY OF POTENTIAL HEALTH RISKS
INTERSIL/SIEMENS, CUPERTINO, CALIFORNIA
POTENTIAL UPPERBOUND
HAZARD INDEX
EXCESS LIFETIME
SCENARIO
PRESENT-USE SCENARIOS
Ingestion of groundwater
Municipal Well No. 24
Inhalation of VOCs-
Municipal Well No. 24
Inhalation of chemicals volatilized
from on-site sofls - Siemens:
Intersil:
FUTURE-USE SCENARIOS
Direct contact with on-site soils
- children
Direct contact with on-site soils
- adults gardening
Ingestion of groundwater
- A-Zone
Inhalation of VOCs - A-Zone
groundwater
Ingestion of groundwater
- B-Zone
Inhalation of VOCs - B-Zone
groundwater
Ingestion of groundwater
- C-Zone
Inhalation of VOCs -
C-Zone groundwater
Ingestion of groundwater
- Deeper Zones
Inhalation of VOCs
- Deeper Zones
Inhalation of chemicals votatSzed
from on-site soils - Siemens:
Intersil:
CANCER
AVERAGE
--
-
2 x Iff"
1 x 10'"
-
3 x 10*
2 x Iff7
1 x ^a4
2 x 1CT*
8 x 10'5
9x Iff5
9x Iff5
2 x 10"*
4 x 10"*
7x Iff6
4 x Iff"
2 x Iff70
RISKS
PLAUSIBLE
MAXIMUM
-
-
1 x Iff70
7 x 1ff'°
4 x Iff5
8X 10*
4 X ID'2
8 X 10'2
1 x 10'3
1 X 10'3
3 x 10~*
6 x 10"*
1 x 10'5
3 x 10'5
2 x Iff10
9 x Iff70
AVERAGE PLAUSIBLE
MAXIMUM
<1 <1
<1 <1
<1 <1
<1 <1
<1 1
<1 <1
>1 >1
<1 1
1 >1
<1 <1
<1 <1
<1 <1
<1 <1
<1 <1
<1 <1
<1 <1
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TABLE 2
ALTERNATIVES ANALYSIS SUMMARY
OF RECOMMENDED ALTERNATIVES
LF 1218
Short- tens
Alternatives Effectiveness
Alternative 1 Mo increased
- No Action exposure risk;
w/ Monitoring potential risks
for future use
scenarios; very
long time to
reach goals
Long- tens Reduction of
Effectiveness Toxicity. Mobility
and Permanence and Voluse Implemei
Mo Migration of VOCs are diluted, sorbed Implemeni
adverse environmental and degraded over time
effects; possible decreasing toxicity, but
Migration of chemicals voluse and affected area
to drinking water- are Increased
aquifers
Overall Protection
Coapl lance with of Human Health and
liability Cost (dollars)* ARARs ft TBCs the Environment
table Capital: Wouldn't achieve goals VOCs exceeding goals
0 for very long time, remain In potential
Annual OM: If ever drinking water source
152.160
Present Worth:
2,880,000
Alternative 2 No Increased Thenasl regeneration
- Contain VOC Migration exposure risk of VES carbon offers
Extract ft Treat Ground fras VES; ailnlMl permanent VOC
Water
Phased Soil Vapor
Removal
risks fro*
stripper
CMlssions. VES
ft ground water
extraction reduce
tie* to reach
remedial goals
over Alt. 1
destruction
VOCs are diluted, sorbed Implementable. Capital: Would achieve goals Protective; treated
and degraded over tl«e subject to permitt 365,873 sooner than Alt. 1; effluent disposal to
decreasing toxlcity; Annual DIM: would not address Calabazas Creek will
chemical input to ground 258,205 non-volatile chemicals not deplete ground
water fro» soils reduced; Present Worth: water due to
ground water Migration 4,870,000 recharge; residual
controled; carbon . risks extremely low
regeneration reduces
voluae of VOCs
Alternative 3 Sams as Alt. 2;
- Contain VOC Migration Ves ft ground
- Accelerate VOC Reaoval water extraction
Extract ft Treat Ground reduce tie* to
Water reach remedial
goals over Alts.
- Phased Soil Vapor 1 t 2
Removal
Thenasl regeneration
VES carbon offers
permanent VOC
destruction
Same as Alt. 2
Implementable, Capital: Would achieve goals Protective; treated
subject to per*,lt> 431,955 sooner than Alt. 2; effluent disposal to
Annual OM: would not address Calabazas Creek will
264,325 non-volatile chemicals not deplete ground
Present Worth: water due to
5,030,000 . recharge; residual
risk extremely low
onasses.ukq
Page 1
15-Jun-90
-------
ALTERNATIVES ANALYSIS SUMMARY
OF RECOMMENDED ALTERNATIVES
LF 1218
Alternatives
Short-term
Effectiveness
Long-term
Effectiveness
and Permanence
Reduction of
Toxic Ity. Mobility
and Volume
Implement ability Cost (dollars)*
Compliance with
ARARs ft TBCs
Overall Protection
of Human Health and
the Environment
Alternative 4
- Soil Excavation
Areas 1 ft 3
as Alt. 3; less
residual seal-vola-
tile* than Alts. 1.
2. ft 3; soil Incinera-
tion permanently
Excavation poses
greatest human
expoaura risk;
no increseed
- Contain VOC Migration exposure risk
- Accelerate VOC Removal fro* VES; minimal destroys VOC* ft sesil
Extract ft Treat Ground risks fro* air volatile*
Water stripper emissions
- Phased Soil Vapor
Removal
as Alt. 2; soil
incineration reduces
volume of chemicals
Not easy to Impta-Capltal: Would achieve goals
went; safety 852,67* sooner than Alt. 2;
concerns; space Annual OtN: Mould remove seml-
lImitations; nould 270.554 volatlles from sits
disrupt business Present Worth:
5.660,000
Will achieve remedial
goala for site. Mould
Increase health risk
through short-term
exposure during
construction;
residual risk
extremely tow
Alternative 5
- Soil Excavation
Areas 1 ft 3
- Contain VOC Migration
- Accelerate VOC Removal
Extract ft Treat Ground
Water
as Alt. 4
Alt. 4
as Alt. 2; soil
Incineration reduces
voluM of chemical a
Same as Alt. 4. Capital: Would achieve goala
even more dlsrup- 966,648 sooner than Alt. 2;
tion to facility Annual OftM: Mould remove seml-
306.633 volatiles from site
Present Worth:
6.360.000
Will achieve remedial
goala for site. Mould
increase health risk
through short-term
exposure during
construction;
residual risk
extremely low
Phased Soil Vapor
Removal
onasses.u
15-Jun-90
-------
ALTERNATIVES ANALYSIS SUMMARY
OF RECOMMENDED ALTERNATIVES
LF 1218
mmmmmmmmmmmmmm
Alternat
•«••••
Ives
!•••••••••••••••••••••••«
Short -tens
Effectiveness
Long- tens
Effectiveness
and Penaanence
Reduction of
Toxlcity, Mobility
and Voluae
Compliance with
iMpleacntablllty Cost (dollars)* ARARs ft TBCs
Overall Protection
of Hum Health and
the Environment
Alternative 6 SaM as Alt. 4; toll Incarceration ft
- Soil Excavation also will take a thenaal VE8 carbon
Areaa IAS very long tla» to regeneration offers
reach "background paraanent cheaical
- Contain VOC Migration levels" In ground destruction; less
- Accelerate VOC Reaoval water residual seat-volatlies
Extract t Treat Ground than Alts. 1. 2. 13;
Water less residual VOCs In
ground Meter than all
- Phased Soil Vapor other alternatives
•eauval
as Alt. 2; soil
Incineration reduces
volume of cheaicals
as Alt. 4; Capital: It would take a very Protective; less
also lapleaenta- 852,674 long tla* to reach residual risk than
bit I ty for the Annual OM: "background levels" other Alternatives
estimated 450 year 270,534
project life Is Present Worth: '
uncertain 5.660,000
Overall project
costs Mould be
•uch higher due
to long-tens
ground-Mater
extraction
m*nmmmmmmmmmmmmmmm
Notes: 1) Evaluation of support agency and CoMunlty acceptance Mill be Included after appropriate rev leu process.
2) Costs are divided Into capital coats for lapleaientatlon of aystea*, first year annual operation and ealntenence
costs, and a 10-year present worth cost. The 1-year period Mas chosen as representative; for other tie* periods
ranging fro* 1 to 30 years, see detailed alternative present worth tables.
masses, wkq
Page 3
15-Jun-90
-------
TABLE 3
COMPARISON OF ALTERNATIVES
Alternative
1
No Action
II
Existing
Remedial
Action
IU
Expanded
Remedial
Action
IV
Expanded
Remedial
•Action
with
Reinfection
y
Minimal
Long-Term
Management
VI
VI
Exceeds
^ARARs
Protection Of
Human Health
and Environment
Not protective
/
>
Protective
Protective
Protective
Protective
Protective
Compliance
with ARARs
/N.
//n
/ / /
>^ ^s s
^^i»8^
i
<(
Yes
Yes
Yes
Exceeds
ARARs
Long-term
Effectiveness
Not effective
..
/ ^«.
^Bf£live\
/N?\fc-<' )
) \
J )
(/
Effecliv*^
Effective
Effective
Effective
Reduction Of
ToxicHy, Mobility
or volume
No reduction of
T.M.orV
Reduction of T, M.
andV
^s\^
jTsj /
Reduc/ion of T, M,
Increase in M,
reduction in T,
potential increase
inV
Increase in M,
reduction ol T
andV
Reduction of T,
M.andV
Short-term
Effectiveness
Not effective
Minimal impact
during
implementation
and operation,
longest time to
achieve ARARs
Some impact
during
implementation,
minimal impact
/during operation,
less time to
/achieve ARARs
V|han Alternative II
s. Some impact
x^ during \v\
implementation*
potential impact
during operation,/
potentially less'
time to achieve
ARARs than
Alternative III
Major impacts
during
implementation,
shortest time to
achieve ARARs
Requires longest
time to complete
Implementablllty
Implementable
Implemented
Implementable
sLess implementable
than Alternative III
"because of technical
and administrative
feasibility of
reinjection wells
Most difficult to
implement
May be technically
inleasible to achieve
background
concentrations
Cost
(Net present
value)
$4.0 million
$9.8 million
$10.1 million
$10.7 million
$37 million
-
Over
$10.7 million
-------
TABLE 4
ALTERNATIVES EVALUATION SUMMARY
LF 158*
Alternative*
Alternative 1
-No Action
w/ Monitoring
Short-term
Effectiveness
Time to reach remedial
goal la very long;
does not satisfy RAO
of environmental
protection
••••••••••••••••••••••••••i
Long-term
Effectiveness
and Permanence
No mitigation of
adverse environmental
effect*
Reduction of
Toxicity. Mobility
and Volume Implemented I Ity
VOC* are diluted, sorbed Implementable
and degraded over time
decreasing toxicity. but
volume is Increased
Cost (dollar*)'
Capital: 0
Annual OlM:
79.160
Present Worth:
1. 216.883
Compliance with
' ARARs t TBCS
Would not achieve
remedial goals
for a long time
Overall Protection
of Human Health and
the Environment
Doe* not address
loss' of potential
resource, nor
potential exposures
from use of shallow
ground water
Alternative 2.1.A
-Extract fro*
well LO-2B
-Air Stripping
Treatment
-Discharge Treated
Effluent to
Calabazas Creek
No increased expoaure
risk; time to reach
goal* less than for
Alt. 1; air •tripping
effective for Indicator
chemical*
VOCa removed fro*
subsurface
VOC concentration in
ground water decreased
by extraction; mobility
reduced by new gradient
Treatment lowers toxi-
city and volume of VOC-
effected ground water
Implementable:
permits required for
extraction system
construction, air
emissions and NPDES
discharge
Capital: Remedial goals Will probably achieve
281,463 will be achieved by remedial goals,
Annual OlM: extraction system; protect humamvu*>
133,960 BAAQMD and NPOES regs health t environment
Present Worth: limit VOC emissions and
2.116,354 discharge
Alternative 2.2.A
-Extract fro*
well LO-2B
-Air Stripping/
GAC Treatment
-Discharge Treated
Effluent to
Calabaia* Creek
No Increased exposure
risk; time to reach
goal* le*a than for
Alt. 1; air stripping
effective for site
VOC*; GAC breakthrough
t spent GAC handling
require proper oper-
ation and haz. waste
management
VOC* removed from
aubeurfac*
Same a* above; VOCa
permanently destroyed
In GAC regeneration
process
Implementable;
permits required for
extraction' system
construction, air
emissions and NPOES
discharge
Capital: Remedial goals
386.981 will be achieved by
Annual OlM: extraction system
138.852 BAAQMD i NPOES~reg*
Present Worth: limit VOC emissions t
2.297,104 discharge; ARARs apply to
spent carbon disposal
Same as above
Alternative 2.3.A
-Extract from well
LQ-2B
-UV/OX Treatment
-Discharge Treated
Effluent to
Calabazas Creek
No Increased exposure
risk If proper opera-
tion*; time to reach
goal* less than for
Alternative 1
VOC* removed from
subsurface
VOCs
premanently destroyed
In UV/OX process
Impl ementable;permi t
required for extrac-
tion system construc-
tion, air emissions
and NPDES discharge;
treatment process
pilot testing required
Capital: Remedial goals Same as above
658.835 will be achieved by
Annual OlM: extraction system
162.141 BAAQMD I NPDES regs
Present Worth: limit VOC emissions t
2,927.027 discharge; ARARs apply to
spent carbon disposal
Alternative 3.1.A
-Extract from
wells LQ-1B,
Id 29. S-2B
-Air Stripping
Treatment
-Discharge Treated
Effluent to
Calabazas Creek
No Increased exposure
risk; time to reach
goal* less than for
Alts. 1 t 2; air
stripping effective
for site VOCs; less
B- to C-zone migration
than Alts. 1 I 2; C-zone
capture
VOC* removed from
subsurface
VOC concentration In
ground water decreased
by extraction; mobility
reduced over Alts 1 t 2;
Treatment lowers toxi-
city and volume of VOC-
affeeted ground water
Implementable;
permits required for
extraction system
construction, air
emissions and NPDES
discharge
Capital: Remedial goals Same as above
459,291 will be achieved by
Annual OtM: extraction system
160,588 BAAQMD t NPDES regs
Present Worth: limit VOC emissions t
2.993,823 discharge; ARARs apply to
spent carbon disposal
1584/OFrSUM.wkq/T4-1
Page 1
18-Jun 90
-------
TABLE 4
ALTERNATIVES EVALUATION SUMMARY
Lf 1584
••1
Alternative*
Short -tens
Effectiveness
Long- tern
Effectiveness
end PenMnence
Reduction of
Toxlclty. Nobility
and VoluM
laplea
entebillty
Cost (dollars)*
Compliance with
ARARs ft TBCs
Overall Protection
of Hunan Health and
the Environment
Alternative 3.2.A
•Extract fro»
wells LO-2B.
LO-li. S-2B
-Air Strlpplng/GAC
Treataent
-Discharge Treated
Effluent to
Caiabaias Creek
No Increased exposure
risk; tie* to reach
goals less than for
Alt. 1; air stripping
effective for site
VOCs; GAC breakthrough
ft spent GAC handling
require proper oper-
ation and hazardous
waste aanageaent; less
I- to C- tone Migration
than Alts. 1 ft 2;
C-tone capture
VOCs removed froa
subsurface
as above; VOCs
permanently destroyed
In GAC regeneration
process
lapleaentable;
penslts required for
extraction systea
construction, air
eaiisslons and NPOES
discharge
Capital: Reaadlal goals Saaa aa above
721,940 will be achieved by
Annual OIM: extraction systea
201,082 BAAQMD ft WOES regs
Present Worth: limit VOC eaisslons ft
3,571,554 discharge; ARARa apply to
spent carbon disposal
Alternative 3.3.A
-Extract from
wells LO-li,
10-28, S-2B
-UV/OK Treataent
-Discharge Treated
Effluent to
Calabazas Creek
No Increased exposure VOCs riao»sd froa
risk If proper opera* subsurface
tion; tiae to reach
goals less than for
Alt. 1;less 8- to C-
zone leakage than
Alta. 1 ft 2; C-zone
capture
Saae as above; VOCs
permanently destroyed
In UV/OX process
lapleaentable; peralts
required for extrac-
tion systea construc-
tion, air ealssions
and NPDES discharge;
treatment process
pilot testing required
Capital:
1,174.849
Annual OIM:
244.335
Present Worth:
4.689,430
Reaedial goals Ssae
will be achieved by
extraction systea
BAAOND ft NPDES regs
Halt VOC emissions ft
discharge; ARARs apply to
spent carbon disposal
as above
Alternative 4.1.A No increased exposure
-Extract froa Nells risk; tiae to reach
LQ-2B. S-2B, RK-2C goals less than for
-Air Stripping Alts. 1. and 2; air
Treataent atripping effective
-Discharge Treated for site VOCs
Effluent to
Calabazas Creek
VOCs reaoved froa
subsurface
Voluat ft Nobility
decreased over Alts
1. 2 ft 3;
Treetaent lowers toxl-
clty and voluM of VOC-
affected ground water;
lapleaentable; peralts
required for extrac-
tion systea construc-
tion, air eaisslons
and NPDES discharge;
•ore trenching in
City streets than
Alts. 1, 2 ft 3
Capital: Reaedial goals
463,356 will be achieved by
Annual OM: extraction systea
157,289 gAAQND ft NPOES regs
Present Worth: liait VOC eaisslons ft
2,647.078 discharge; ARARa apply
to spent carbon
disposal
Will achieve reaediel
goals, protect hunn
health ft environment;
Tiae to reach goals
will be less than
for Alts 1 ft 2
Alternative 4.2.A Seas as above;
-Extract froa wells GAC breakthrough
IQ-2B.S-2B. RK-2C ft spent GAC handling
-Air Stripping/GAC require proper oper-
Treataent •tion and hazardous
-Discharge Treated Maste i
Effluent to
Calabazas Creek
VOCs reaoved froa
subsurface
as above; VOCs
permanently destroyed
in GAC regeneration
process;
Saae as above Capital: Reaedial goals
662.922 will be achieved by
Annual OIM: extraction systea
170,918 BAAOMD regs liait VOC
Present Worth: ealssions; ARARs apply
3,056,191 to spent carbon
disposal
Saae as above
1584/Or ikq/U-1
18-Jun-W
-------
TABLE 4
ALTERNATIVES EVALUATION
LF 1584
SUMMARY
Alternative*
Short-tens
Effectiveness
Long-term
Effectiveness
end PenMnence
Reduction of
Toxlclty. Nobility
•nd Volume
lapleaentebllity Cost (dollar*)*
Compliance ulth
ARARs t liCs
Overall Protection
of Huamn Health and
the Environment
Alternative 4.3.A No Increased exposure
-Extract.fro» Malls risk if proper opera*
LQ-2B.S-2B, RK-2C tlon; time to reach
-UV/OX Treatment goals less than for
-Discharge Treated Alts. 1 and 2
Effluent to
Calabazas Creek
VOCs removed froa Same as above; VOCs
subsurface; VOCs permanently destroyed
permanently destroyed In UV/OX process
In UV/OX process
Same as above;
treatment process
pilot testing
required
Capital: Remedial goals
1.046,123 will be achieved by
Annual OM: extraction systeai;
205.307 BAAQMD regs llailt
Present Worth: VOC eatssions
3,969.325
Seme as above
Alternative 5.1.A
-Extract fro* four
•- ft C-sone nails
-Air Stripping
Treatment
-Discharge Treated
Effluent to
CaIabates Creek
No Increased exposure
risk; tia* to reach
goals less than for
Alts. 1.2 ft 3; air
stripping effective
for site VOCs
VOCs reamed tram
subsurface
VOC cone, ft •ability
decreased over Alts
1. 2. 3 i 4;
Treatment loners toxl-
clty and voluae of VOC-
affected ground water;
Implementabte; penilts Capital:
required for extrac-
tion systsai construc-
tion, sir Missions
and WOES discharge;
•ore trenching in
City streets than
Alts. 1, 2. t 3
ial goals
508.248 Hill be achieved by
Annual OM: extraction system;
165,063 BAAQND regs Halt
Present Worth: VOC esitssions
2,811,476
Will achieve remedial
goals, protect humsn
health t environment;
Time to reach goals
Mill-be less than
for Alts 1.2(3
Alternative 5.2.A
-Extract frosi four
•- ft C-tona Mails
-Air Strlpping/GAC
Treatment
-Discharge Treated
Effluent to
Calabaias Creek
VOCs removed fro*
GAC breakthrough
ft spent GAC handling
require proper oper-
ation and haiardous
Masts
as above; VOCs
permanently destroyed
In GAC regeneration
process;
Capital: Remedial goals
730,754 Mill be achieved by
Annual OM: extraction system
181,189 BAAQND regs Halt VOC
Present Worth: emitsIons; ARARs apply
3.281,904 to spent carbon
disposal
Alternative 5.3.A No Increased exposure
-Extract froa four risk If proper opera-
B- t C-ione Mails tlon; tlas to reach
-UV/OX Treatment ARARS less than for
-Discharge Treated Alts. 1, 2. 3 t 4
Effluent to
Calabazas Creek
VOCs removed from
subsurface
VOCs
permanently destroyed
in UV/OX process
Seas es above;
treatment process
pilot testing
required
Capital: Reaedlal goals
1.155.250 Mill be achieved by
Annual OM: extraction system;
218.852 BAAOND regs Halt
Present Worth: VOC emissions
4,285.437
Seas as above
1584/OFFSUH.Mkq/T4-1
Page 3
18-Jun-90
-------
TABLE *
ALTERNATIVES EVALUATION SUMMARY
LF 1584
Alternatives
Short-term
Effectiveness
long-term
Effectiveness
Reduction of
ToxicIty. Nobility
and VoluM
Implemented 11 ty Cost (dollar*)*
Compliance with
ARARe t TIC*
Overall Protection
of Human Health and
the Environment
Alternative 6.1.A
-Extract from wells
LO-2S, S-28, RK-2C
-Air Stripping
Treatment
-Discharge Treated
Effluent to
Catabazas Creek
No Increased exposure) VOCa famovirt from
riak; air stripping subsurface; leaa
affective for aita
VOCa; Mill take a
vary long time to
reach "background
levels"
residuals In aub-
aurface than other
Alternative*
VOC cone, i Mobility
decreaaed over Alta
1. 2, 3 I 4;
Treatment lower* toxi-
clty and voluao of VOC-
affeeted ground water;
Technically
leplementeble; permits
required for extrac-
tion system construc-
tion, air emissions
and NPOES discharge;
more trenching In
City streets than
Alta. 1. 2, i 3;
long-term Impie-
mentabillty la un-
certain
Capital: Remedial goala
463,356 Mill be achieved by
Annual OM: extraction system;
157.289 8AAOND rega limit
Present Worth: VOC emissions
2,959.686
Overall project
coata Mould be
much higher due
to long-term
ground-water
extraction
Ulll achieve remedial
goala, protect huaan
health I environment
Alternative 6.2.A
-Extract from walla
LQ-28. S-28, RK-2C
-Air Strlpptng/GAC
Treatment
-Discharge Treeted
Effluent to
Calabazaa Creek
GAC breakthrough
I spent GAC handling
require proper oper-
ation and hazardous
waste management; Mill
take • vary long time to
reach "background
levele"
Same aa above; VOCa
permanently destroyed
In GAC regeneration
process;
Capital: Remedial goala
558,553 Mill be achieved by
Annual OM: extraction system
170.918 BAAQMD rega limit VOC
Present Worth: emissions; ARARs apply
3.264,431 to apent carbon
Overall projactdlapoaal
costs would be
much higher due
to long-term
ground-water
extraction
Saae aa above
Alternative 6.3.A No Increased exposure VOCa removed from Same aa above; VOCa
-Extract from Malta rlak If proper opera- subsurface; VOCa permanently destroyed
IQ-28. S-2R, RK-2C tlon; Mill take a permanently destroyed In UV/OX process
-UV/OX Treatment very long time to In UV/OX process; leas
-Dlacharge Treated reach "background residuals In sub-
Effluent to levels" surface than other
Calabazaa Creek Alternatives
treatment process
pilot testing
required
Capital: Remedial goala
1.046,123 Mill be achieved by
Annual OM: extraction system;
205.387 BAAOMD regs limit
Present Worth: VOC emissions
4.281.933
Overall project
coets Mould be
auch higher due
to long-term
ground-water
extraction
aa above
NOTES:
Evaluation of State and comaunity acceptance Milt be Included efter appropriate review process.
Costs are divided into implementation, capital coats, first year annual operation and maintenance costs, and a
30-year present worth cost. Overall project cost depends upon the time required to reach remedial goals (Table 4-2).
Costs do not include legal, land use or closure/abandonment costs.
1584/OFrT
I/T4-1
8-JUT 90
-------
REVISED RESPONSIVENESS SUMMARY
for Comments and Questions Received During
June 13 - August 6, 1990
on the
Final Remedial Action Plan
for the
Intersil / Siemens Proposed Superfund Site
Cupertino, Santa Clara County
Introduction
This revised responsiveness summary reviews comments and questions received through August 6,
1990 regarding the proposed remedial action plan (RAP) for the Intersil / Siemens proposed
Superfund site. The RAP consists of expanded soil vapor extraction and treatment expanded
groundwater extraction and treatment, and limited soil excavation. The RAP is formally presented in
the Remedial Investigation / Feasibility Study (RI/FS) reports, the proposed plan fact sheet (dated
June 1990) and the proposed final Site Cleanup Order (SCO) for the site. The public comment
period on the RI/FS, the proposed plan fact sheet and the SCO was from June 13, 1990 to July 13,
1990. The Board held a public hearing on the RAP and SCO during its June 20, 1990 meeting.
Intersil and Siemens have commented in writing twice on the SCO. AMI, the Department of Health
Services: Office of Drinking Water (ODW), the City of Santa Clara and the Santa Clara Valley Water
District (SCVWD) also commented on the SCO. One nearby homeowner asked similar questions
covered in the public meetings, the letter and response letter are attached. One nearby homeowner
submitted a letter (attached) suggesting that Intersil and Siemens should post a bond large enough to
cover the costs of cleanup. This is discussed in the Regulatory Oversight section. No other written
comments were received during the comment period, nor was there any requests for a time
extension. Four letters of comment and/or question were received after the close of the period. The
four letters of comments include further explanation by ODW oh their earlier comments; letters with
similar comments as ODW's from the City of Santa Clara and the SCVWD; and a response from
Intersil to the July 11 ODW comments. All comments, including the last four letters of comment are
responded to in this Revised Responsiveness Summary.
During the community meeting that took place in Santa Clara on June 21, 1990, community members
orally asked numerous questions regarding the site history and effects as well as details on the RI/FS
and RAP. The audience had two significant comments/questions on the RAP concerning (1) the
length of time to achieve cleanup of 45 to 85 years was too long and that methods to shorten the
time to cleanup should be reevaluated, and (2) who was going to provide regulatory oversight for
tine lengthy cleanup.
The summary of the significant comments and response to those comments are summarized below.
A recent EPA memo established a two part approach to responsiveness summaries. This document is
presented in one part because Regional Board staff believe at this time that tine issues and responses
are succinct enough that a two part approach is not warranted.
The Administrative Record for the site is available at the Sunnyvale Public Library and at the
Regional Board Offices.
Community Relations Activities
The major community relations activities are listed below:
July 1989 Fact Sheet No. 1
September 1989 Community Meeting No. 1
January 1990 Fact Sheet No. 2, Answers to Questions from Public
June 1990 Fact Sheet No. 3, Community Meeting No. 2
*<«<•<«. mo
Page 1 of 5
-------
Local Community Comments
Significant Issues and Concerns:
General:
Numerous questions were asked during the community meeting regarding the site history, site
investigation, extent of soil and groundwater pollution, baseline public health evaluation,
performance of interim remedial actions and the proposed RAP. These questions were all answered
at the community meeting, in Fact Sheet No. 2, Answers to Questions from Public, and in the
proposed plan Fact Sheet No. 3. A survey of the people attending the June 21, 1990 community
meeting showed that only three people in attendance had also attended the September 1989
community meeting. Most of the questions asked during the June community meeting were similar
to questions asked during the September community meeting. Answers to these questions were
provided at the June community meeting and were documented in Fact Sheet No. 2. One letter was
received from a nearby homeowner with questions similar to those at the community meeting
regarding the site investigation and cleanup and these questions were answered by letter. This
comment letter and staff response letter back are included as an attachment
Time to Achieve Cleanup Levels:
The most significant question / concern that arose during die public meeting was why does it take
so long to achieve cleanup and is there any additional work that could be done to shorten the time
necessary for cleanup.
The time to achieve cleanup levels for the proposed alternatives is presented in the following table.
Time to Achieve Geanup Levels (Years)
Siemens On-Site Intersil On-Site Off-Site
Soil 11 5 N/A
Groundwater 45-85 60 20-45
Soil cleanup times are relatively short when compared to groundwater cleanup times. Volatile
organic compounds (VOCs) such as trichloroethene (TCE), the main chemical of concern at the sites,
are extracted much quicker when they exist in soil in a vapor state rather than when the VOCs are
dissolved in groundwater. When VOCs are dissolved in groundwater, the VOCs adsorb or attach to
the soil particles where the groundwater is present and become trapped inside openings or crevices
on the soil particles, and it becomes very difficult to remove the adsorbed VOCs. As groundwater is
pumped from a contaminated aquifer, VOCs slowly desorb or detach from the soil particles and are
extracted with the groundwater. Within limits this process may be speeded up by pumping at a
higher flow rate, however, due to the limiting factors of desorption, a point of decreasing VOC
removal will be reached so that any additional pumping rate increases will not shorten the cleanup
time.
On-Site Areas
The shallowest groundwater zone beneath Intersil and Siemens, the A-zone, has a very low
permeability (ability to transmit water) so that the A-zone will dewater or dry up if exposed to high
groundwater pumping rates. For this reason, the cleanup time from the A-zone groundwater is
limited by the amount of water that may be pumped from the A-zone. Modeling has shown that if
the A-zone is pumped at any greater rate than is currently proposed 2.7 gallons per minute (gpm) at
Page 2 of 5
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Intersil and 7 gpm at Siemens, it will dewater and groundwater extraction will no longer be effective
except for the ongoing soil vapor extraction.
Intersil's on-site alternative No. 4 considered reinjection of groundwater at the site to increase the
pumping rate from 2.7 gpm to 3.3 gpm. This decreased the cleanup time from 60 years to 45 years.
However, this alternative was not selected due to the difficulties in controlling the reinjected water
and concerns that the reinjection could spread tine contamination. Intersil's on-site alternative No. 5
increased the rate of reinjection so that the groundwater pumping rate could be increased from 3.3
gpm to 73 gpm. This increased flow rate decreased the cleanup time from 45 years to 20 years.
This alternative was also not selected due to the difficulties with reinjection.
Off-Site Area
For the off-site area proposed cleanup alternative No. 3, the B-zone groundwater is currently
proposed to be pumped at 105 gpm. The B-zone is able to be pumped at a much higher rate than
the A-zone due to the greater permeability and size of the B-zone. The B-zone is proposed to be
pumped at this relatively high rate in order to capture and cleanup C-zone groundwater also. Off-
site alternative No. 4, which was not recommended, proposed to pump the B-zone at 45 gpm. By
increasing the pumping rate in the B-zone from 45 gpm to 105 gpm, the cleanup time in the B-zone
decreases from a range of 20 - 50 years to a range of 20 - 45 years. By doubling the pumping rate
in the B-zone, only 5 years is reduced from the upper range of predicted cleanup times. This is
again due to the difficulty in extracting the VOCs from the clay soils. Soil gas extraction is not
feasible off-site.
Groundwater conservation is also considered in selecting the proposed RAP. The relatively high
pumping rate in the B-zone has to be balanced against groundwater conservation and the concern of
limiting withdrawals from the groundwater resources during drought periods.
In conclusion, the Regional Board staff believe the proposed alternatives combine the best of
effectiveness, implementability, groundwater conservation, and time to cleanup. Progress reviews will
be completed to review progress and achievability and will consider changes available that can speed
cleanup.
Regulatory Oversight Adoption of the SCO requires periodic reporting by Intersil and Siemens on
their activities to achieve cleanup. These reports are public record and will also be sent to the Cities
of Santa Clara, Cupertino, and Sunnyvale. Additionally, until the site is cleaned up to the
requirements of the SCO, the Regional Board and/or EPA will provide regulatory oversight
Superfund requires a formal review of the progress every 5 years until cleanup. If the Regional
Board is still the lead agency this review will be noticed at least by publication and distribution of
the agenda for the meeting where the Board reviews the cleanup progress, where the status report
and recommendations can be obtained for review, and how the public can comment on any
proposed Board actions in writing or at a public hearing. If the Board amends the cleanup
requirements, this would also be done with public notice at a public hearing. It is expected that
EPA, if they are die lead regulatory agency, would offer the public the same opportunities during
reviews and/or changes.
One comment letter suggested the companies should post a bond large enough to cover die cost of
cleanup. The Board has not made this a practice in the past, instead relying on its enforcement
authority to require completion of cleanups. Intersil and Siemens have completed all necessary
cleanup work required up until this time and there is no reason to believe they will not continue to
do so. Intersil and Siemens are part of two of the biggest companies in the world and have given
all appearances that they are dedicated to completing the cleanup.
Page 3 of 5
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Intersil / Siemens Comments
Intersil and Siemens have commented twice on the SCO. The comments are mainly wording
changes to the SCO for clarification that do not change the intent of the SCO. Most of their
comments have been incorporated into the SCO and the companies do not plan to contest the SCO.
AMI Comments
AMI stated that one finding in the SCO that referenced the AMI off-site groundwater plume was
unwarranted based on the available data. Staff believe the available data is adequate to make the
finding and this finding was not changed.
ODW, SCVWD and City of Santa Clara Comments
The ODW does not agree with the EPA Superfund final cleanup level risk range for carcinogens of
10* to 10*. They also do not agree with the use of MCLs as cleanup levels when more than one
chemical is present at a site. ODW recommends the use of a carcinogenic hazard index (CHI) of
one or a 10* carcinogenic risk level as cleanup levels whenever this level of protection can be
accomplished with reasonable and cost effective operational measures. SCVWD and the City of
Santa Clara have recommended using a 10* carcinogenic risk level as a cleanup standard for
currently used drinking water zones. The SCVWD and City of Santa Clara recommendations are
apparently based on their concern that DHS will be promulgating Recommended Public Health
Levels (RPHL) for chemicals in drinking water that will be set at the 104 risk level for each chemical.
Staff disagrees with ODW's use of the CHI and the 10* carcinogenic risk level as cleanup standards
because both are inconsistent with EPA standards contained in tine National Oil and Hazardous
Substances Pollution Contingency Plan (NCP), 40 CFR Part 300, March 8, 1990, the Superfund Public
Health Evaluation Manual (SPHEM), (EPA, 1986), the Risk Assessment Guidance for Superfund,
Human Health Evaluation Manual (RAGS), (EPA, 1989), and the Guidance for Conducting Remedial
Investigations and Feasibility Studies Under CERCLA, (EPA, 1988).
By using ODW's CHI with maximum contaminant levels (MCLs) in the denominator, a different risk
level for cleanup is obtained with each different suite of chemicals. By using ODW's CHI of one,
staff would be advocating cleanup at the different Superfund sites to variable risk levels with no
technical or economic basis for these decisions. Staff believes this is poor risk management and risk
communication.
ODW cites the technical and economic analysis that went into promulgation of MCLs as one basis
for using MCLs in the denominator of their CHL However, these technical and economic
evaluations used for promulgating MCLs are completely different than the technical and economic
evaluations made in remediating volatile organic compounds (VOCs) from sand and day aquifers.
For the Intersil / Siemens Site, the time necessary to achieve cleanup at this site is currently modeled
at 45 to 85 years and the 30-year present worth cost is $19 million. Superfund requires that an
independent risk-based analysis of cleanup levels be completed for each Superfund site. No mention
of a CHI is made in either EPA Superfund guidelines, and these guidelines do contain procedures
that address the additive effects of multiple chemicals and multiple exposure pathways which appear
to be ODW's main concerns.
In regards to the RPHLs, they are currently not promulgated and therefore may not be used as
cleanup standards. The law establishing RPHLs also did not set a specific risk level (e.g. 104)-, these
levels will be set in regulations by DHS by mid-1991. Upon promulgation of RPHLs, they will be
evaluated for use as Applicable or Relevant and Appropriate Requirements (ARARs) for cleanup
Pag* 4 of 5
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standards. - .
Because of the inconsistencies and differences between the EPA and ODW procedures, staff believes
EPA recommended risk management and risk communication techniques should be followed for all
Regional Board lead cleanup sites.
The SCO also contains tasks to reevaluate cleanup levels based on new technical or health
information. If ODW's recommendations should become codified in law or regulations, then the
SCO could be modified to include the new standards.
Notwithstanding staffs' recommendation to follow all.EPA recommended risk assessment and
management procedures, the ODW CHI would be one for the C-zone, ODW's primary zone of
interest since it is apparently used as a drinking water source in the Valley. The CHI would be one
because there is only one ODW recognized carcinogen, TCE, in the C-zone. Also, depending on the
methods used to predict cleanup and risk (Siemens and Intersil used slightly different methods),
ODW's, SCVWD's and the City of Santa Clara's goal of a 10* risk level may also be met at this site
under the current cleanup plan. Which of the methods for predicting cleanup is more accurate will
not be known for many years, based on predicted and actual performances. Finally, the differences
in cleanup levels between what the SCO calls for and ODW recommends are in the order of 5 ppb
vs. 2 ppb. These differences are difficult to measure, let alone achieve, with current technology.
Groundwater Pumping from the C-Zone
Alternatives 4 and 5 in the off-site FS and in the SCO included a groundwater extraction well(s)
screened in the C-zone. These alternatives were not selected because of the adverse community
impacts involved in the installation of an additional groundwater pipeline on Redwing Ave. and
because of pump tests and modelling that showed that the C-zone would be remediated through
pumping in the B-zone. Remediation of the C-zone is as high a priority of the RAP as remediation
of the A- and B-zones, If a reduction in C-zone concentrations is not demonstrated after one year,
the plan contains a contingency for the installation of C-zone extraction well(s). The time to achieve
cleanup and the cost for alternatives 4 and 5 were similar to that of the selected alternative,
alternative 3.
No changes are recommended to the RAP or the SCO in response to DHS, SCVWD or City of Santa
Clara comments.
Attachment
Page 5 of 5
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Mr. John Wolfenden
Case Manager
Regional Water Quality Control Bdg.
1800 Harrison Street, Suite 700
Oakland, Ca 94612
Dear Mr. Wolfenden:
Will you please answer a few questions relating to the Siemen/s
Intersil cleanup of their contaminants in soil in the Quail/
Inverness area:
1. I live across Home'stead from Siemen's. My son owns a
rental property on Homestead even closer to Siemen's.
Will the soil contamination under my house cause me
or my family health problems 1n the future?
2. What happened to all the contaminated soil removed by
Trumpp Bros, during their months of ditch digging to
install certain pipes? I will not bring up the incon-
venience that noise caused to those of us fronting
onto the work.
3. Your June 1990 pamphlet suggested that there are
several treatment areas. Aside from Siemen's or the
Intersil former location on Tantau, where are the
other treatment systems located?
4. If the ground is contaminated down to 300 feet, what
about us eating fruits and vegetables grown in that
soil?
Will try to attend your June 21st meeting at Laurel wood but
please do reply to the questions asked above. Who is paying
the cost of all this cleanup and treatment?
Cordially yours,
VIVIAN KRODEL
1696 Quail Avenue
Sunnyvale, Ca 94087
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o
STATE OF CALIFORNIA
GEORGE DEUKMEJIAN, Oovtrnor
CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD
SAN FRANCISCO BAY REGION
1800 HARRISON STREET, SUITE 700
OAKLAND. CA 94612
June 28,
.2189.81
1990
8124
'818T}
Mrs. Vivian Krodel
1696 Quail Avenue
Sunnyvale, CA 94087
Dear,Mrs. Krodel:
Thank you for attending the Intersil/Siemens community meeting on
June 21. I hope that we were able to answer some of your questions
and concerns. As you requested, I will try to respond specifically
to the questions raised in your letter.
1. Will the soil contamination under my house cause me or my
family health problems in the future?
Soil contamination from Intersil and Siemens has extended
off-site to an area between Homestead Road and Lome Way.
However, the levels in the soil north of the facilities
is low, less than 3 parts per million TCE, and is found
at depths of 40 feet or more. Further, a public health
evaluation was conducted to evaluate current and potential
future health risks posed by the site. The evaluation
concluded that the carcinogenic risk for direct contact
with on-site soils for children and adults is 3 potential
excess cancer cases in 1 million and 2 potential excess
cancer cases in 10 million, respectively, and the non-
carcinogenic hazard index is less than one. The
carcinogenic risk from inhalation of chemicals volatilized
from on-site soils is 1 potential excess cancer risk in
100 billion and the hazard index for inhalation of VOCs
volatilized from on-site soils is less than one. On-site
soils are contaminated with VOCs at much higher levels and
at much shallower depths than the off-site areas. EPA
considers carcinogenic risk ranges of 1 potential excess
cancer risk in 10 thousand to 1 in 1 million and hazard
indexes of up to 1 to be protective of public health.
Therefore, we do not believe that the off-site soil
contamination poses a threat to public health.
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2. What happened to all the contaminated soil removed by '
Trvunpp Bros, during their months of ditch digging to
install certain pipes?
The pipeline was installed along Quail Avenue to convey
groundwater from the off-site extraction wells to the
treatment system at the Siemens facility.. The soil
removed was not contaminated with VOCs from Intersil and
Siemens and was used to back-fill the ditches.
3. Aside from Siemen's or the Intersil former location on
Tantau, where are the other treatment systems located?
All of the treatment systems are located at the Intersil
and Siemens facilities. The selected remedial
alternatives will expand the existing on-site soil vapor
extraction and treatment and groundwater extraction and
treatment systems. Groundwater extracted from wells off-
site will continue to be treated at the Siemens facility.
The extracted groundwater will continue to be transported
to the facility via the underground pipeline along Quail
Avenue. The pipeline is double-contained to prevent
• leaks.
4. If the ground is contaminated down to 300 feet, what about
us eating fruits and vegetables grown in that soil?
Soil contamination is limited to the facilties, to an area
approximately 200 feet east and west of the facilities, and
to the north between Homestead Road and Lome Way. Near
Homestead Road, the soil contamination is deeper than 40
feet. The contamination is not found in a concentration
or at a depth that should have any impact on fruits or
vegetables. Also, polluted groundwater is found off-site
at depths of greater than 100 feet, below the root zone
of fruit trees or vegetable crops.
The Intersil and Siemens companies have paid for the investigations
and cleanups to date and are expected to continue to do so. As a
proposed Superfund site, the federal Superfund Trust Fund will step
in and continue the cleanups should Intersil and Siemens fail their
responsibilities. The $8.5 billion Trust Fund is primarily funded
by a tax on the chemical and petroleum industries.
I hope I was able to answer your questions. Please let me know if
you have any other questions or concerns.
Sincerely
"
John D. Wolfenden
Case Manager
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1696 Quail Avenue . ' ----,..
Sunnyvale, Ca 94087 - ' -: -.. „ !
August 4, 1990
California Regional Water Quality Control Bd. ^'^ 0 '/ ;~
1800 Harrison Street, Suite 700 ,.,. .
Oakland, Ca 94612 t--- Uf/ Cjl:,i: ,L ,
Subject: Inters 11 /Siemens soil contamination
Gentlemen:
I was not able to attend the public hearing at the Laurel wood
School on June 21, 1990, but I have learned what was discussed
at that meeting and would like to make an earnest request:
That both companies put up a heavy bond to make sure they will pay
for this cleanup In years to come. I have learned that it may
take 45 years or more to get this mess cleaned up. I own a
property directly across the street from Siemen's and another
on the southwest corner of Quail and Homestead. This contamina-
tion will affect the salablUty of these properties for all
those 45 years.
We should not have to spend our tax dollars for this cleanup!
The suggestion was made that this work 1s eligible for Federal
cleanup funds. If I were an executive on either of those two
firms involved so far, I would have made a specific note of
of that information. Let's make SURE Intersil and Siemens
post a high enough bond to make them fully responsible for the
cleanup of their mess... for as long as It takes.
We have tolerated the noisy equipment needed to tear up our
streets and the Installation of pipes and electrical systems
underground (with all the notes associated with their Installa-
tion); we have put up with steel plates banging day and night
as carshit them; we have bitten our nails over the slow pace
of getting this cleanup started — but we should not have to
put up with taxpayers paying for spills caused by these two
major companies.
Cordially yours,
PS: It 1s my understanding that there will be a Public Hearing
in Oakland 1n August and I would like this made a part of
those, proceedings.
G.M.K.
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APPENDIX A
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CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD
SAN FRANCISCO BAY REGION
ORDER NO. 90-119
SITE CLEANUP REQUIREMENTS FOR:
SIEMENS COMPONENTS, INC INTERSIL, INC
19000 HOMESTEAD ROAD 10900 NORTH TANTAU AYR
CUPERTINO CUPERTINO
SANTA CLARA COUNTY SANTA CLARA COUNTY
VALLCO PARK, LTD.
CUPERTINO
SANTA CLARA COUNTY
The California Regional Water Quality Control Board, .San Francisco Bay Region (hereinafter called
the Board) finds that
L Site Location and Description This Order presents the selected final remedial action plan for
the Intersil / Siemens proposed Superfund site. The Siemens Components, Inc. (Siemens)
facility is located at 19000 Homestead Road, Cupertino, and the former Intersil, Inc. (Intersil)
facility is located at 10900 North Tantau Ave., Cupertino (Figure 1). Siemens and Intersil
lease their respective properties from the piopeity owner, Vallco Park, Ltd.
The properties are located on approximately 12 acres at the southeast comer of North Tantau
Ave. and Homestead Rd. in Cupertino near the borders of the City of Sunnyvale and the
City of Santa Clara. The two properties are adjacent to each other, separated by Forge Drive
(Figure 1). The surrounding terrain gently slopes northeast towards San Francisco Bay,
which lies approximately 75 miles north of the Site. Calabazas Creek lies approximately 0.2
miles east of the Site and flows to the northeast
2. Description of the Selected Remedy The selected remedy for the rites consists of:
o Soil vapor extraction and treatment and soil excavation for soil cleanup
o Groundwater extraction and treatment for groundwater cleanup
o Shallow zone and deeper aquifer groundwater monitoring and soil monitoring
There are currently seven soil vapor extraction wells and nine groundwater extraction wells
operating at the Site. The final remedial action plan will include the installation of 16
additional soil vapor extraction wells and 10 additional groundwater extractions wells. Vapor
phase carbon adsorption will be used for the soil vapor treatment and air stripping will be
used for groundwater treatment
3. Administrative Orders The following administrative orders have been adopted for Siemens
and Intersil:
Siemens
o June 1986 - Order No. 86-48, Waste Discharge Requirements (Site Cleanup
Requirements)
1
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o May 1987 - Order No. 87-045, NPDES No. CA0029190
o September 1987 - Cleanup and Abatement Order No. 87-133
o March 1989 - Order No. 89-038, Site Cleanup Requirements
Intersil
o April 1986 - Administrative Civil Liability
o June 1986 - Order No. 86-49, Waste Discharge Requirements (Site Cleanup
Requirements)
o September 1987 - Cleanup and Abatement Order No. 87-133
o October 1987 - Order No. 87-133, NPDES No. CA0029262
o March 1989 - Order No. 89-133, Site Cleanup Requirements
Site History Siemens produces a variety of light emitting diode (LED) semiconductor
products used as components in optoelectronic products. Until approximately 1988, the
manufacturing process consisted of LED ingot growing (where a gallium arsenide ingot was
produced), and currently consists of wafer fabrication. Intersil formerly assembled
semiconductor devices, including low power complimentary metal oxide semiconductors, and
linear and discrete semiconductors, for use in various electronic components. Processes
included wafer masking, etching and diffusion.
The underground waste handling facilities formerly used at Siemens included five unvaulted
waste solvent tanks and an unvaulted acid dilution basin. The five waste solvent tanks and
the acid dilution basin have been excavated Siemens currently treats wastewater using an
acid neutralization system and stores waste solvents above ground Mark Systems, Inc.
initially occupied the property in 1968. Litxonix, Inc. occupied the facility from 1971 to 1978.
Litronix was purchased by Siemens during the period of 1977 to 1978 and the facility has
been operated by Siemens since that time.
The underground waste handling facilities formerly used at Intersil included two vaulted and
one unvaulted acid neutralization systems, two unvaulted scrubber sumps and a vaulted
waste solvent tank. All the underground facilities have been excavated The Intersil facility
was in operation from 1967 to 1988.
The Siemens semiconductor manufacturing operations have used various organic solvents
including trichloroethene (TCE), 1,1,1-trichloroethane (TCA), methanol, isopropanol (IPA),
n-butyl acetate, acetone, xylene, Freon, and commercial mixtures apparently containing
trichlorobenzene (TCB), phenols and toluene. The Intersil semiconductor fabrication
operations have used various organic solvents including TCE, TCA, Freon, xylenes, IPA,
n-butyl acetate, acetone, ethyl benzene, and commercial mixtures apparently containing
phenols and toluene.
In 1982, Intersil and Siemens submitted Facility Questionnaires to Regional Board staff
describing their underground neutralization systems, sumps, and tanks. Based on these
submittals, staff required the initiation of the remedial investigation (Rl) at Siemens and
Intersil in 1982. The RJ has been ongoing for the last eight years. Interim remedial actions
began at Siemens in 1983 with the startup of a soil vapor extraction system. Groundwater
extraction and treatment began at Siemens in 1986. Interim remedial actions began at Intersil
in 1986 when the inactive neutralization system was removed, and continued in 1987 with
the startup of a groundwater extraction and soil vapor extraction system. The feasibility
study (FS) evaluates the interim remedial actions that have been ongoing for the last seven
years and evaluates alternatives for the final remedial action. Intersil and Siemens have
submitted Remedial Investigation / Feasibility Study (RI/PS) reports for the on-site and off-site
areas. The on-site area for each company is the area within the respective property
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boundaries. The RI/FS reports summarize the last eight years of the RI and the last seven
years of the interim remedial actions.
5. SoD Investigation Releases of chemicals have occurred from both the Siemens and Intersil
underground waste handling facilities. Initial subsurface investigations at the Siemens
property have shown solvent concentrations in the soil as high as 21,000 parts per million
(ppm) n-butyl acetate immediately beneath former tank 1A and 11,000 ppm TCA, 17 ppm
TCE and 15,200 ppm trichlorobenzenes immediately beneath former tank 3. Investigations at
the Siemens property show solvent concentrations in the soil as high as 36 ppm TCA at a
depth of 46 feet and 70 ppm TCE at a depth of 30 feet Siemens has installed 62 soil borings
to define the extent of the soil pollution. The extent of soil pollution has been defined to 1
ppm TCE or nondetect levels of TCE towards the west at the Siemens property boundary,
towards the east 200 feet east of the Siemens hazardous material storage area, and on the
north between Homestead Road and Lome Way. At the northern border of the Siemens
' property on the south side of Homestead Road, TCE was detected in a soil boring at 40, 50,
80, and 100 feet deep at concentrations of 1.4, 1.8, 2.7, and 2.5 ppm, respectively. The
southerly extent of the Siemens soil pollution blends together with the northerly extent of
the Intersil soil pollution.
TCE concentrations at Intersil have been found as high as 33 ppm in two soil borings at
depths of 26 and 41 feet in a soil boring near the former inactive east acid neutralization
system and up to 10 ppm at a depth of 595 feet in a soil boring near the north scrubber
sump. Intersil has installed 64 soil borings and analyzed 529 soil samples to define the
extent of the soil pollution. The extent of soil pollution has been defined to 1 ppm TCE or
nondetect levels of TCE towards the west at 200 feet west of the western property boundary,
to the south near the southern edge of the Intersil building, and to the east within the
eastern property boundary. The northerly extent of die Intersil soil pollution blends together
with the southerly extent of the Siemens soil pollution.
6. Hydrogeology The subsurface geology beneath the Site consists of a series of interbedded
coarse-grained sand and gravel and fine-grained silt and day sediment units, representing
alluvial stream channel deposits and associated overbank deposits. The first saturated
materials, a locally perched water zone, occurs at approximately 50 to 60 feet below the
surface at some locations. The first laterally extensive saturated hydrogeologk unit, termed
*e A-zone, occurs between 105 and 120 feet below the ground surface. The next deeper
permeable zone, the B-zone, occurs between approximately 130 and 150 feet below the
ground surface. The next deeper relatively permeable zone, the C-zone, occurs between
approximately 180 and 210 feet below the ground surface. Groundwater in the A-zone, B-
zone and C-zone flows generally to the north, although local variations have been observed.
A downward vertical gradient exists between the hydrogeologic zones. Deep aquifers exist
beneath the Site at depths of approximately 300 to 500 feet below the ground surface,
separated from the C-zone by an approximately 75 foot thick regional aquitard.
7. Groundwater Investigation Groundwater investigations at the Siemens and Intersil properties
have shown the on-site and off-site A-, B-, and C-zones to be polluted with various organic
solvents. 97 monitoring wells have been installed to define the extent of groundwater
pollution. A-zone monitoring wells on the Siemens property have detected TCE
concentrations as high as 26,000 parts per billion (ppb). A-zone monitoring wells on the
Intersil property have detected TCE concentrations as high as 33/100 ppb. B-zone monitoring
wells on die Siemens property have detected TCE concentrations as high as 5080 ppb and
1,1,1-TCA concentrations as high as 1030 ppb. B-zone monitoring wells on die Intersil
pioperty have detected TCE concentrations as high as 950 ppb. C-zone monitoring wells on
die Siemens property have detected less dun 40 ppb organic solvents.
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The groundwater pollution plumes from Siemens and Intersil have commingled in the A-zone
and have migrated to the B-zone and C-zone. The off-site groundwater pollution plume
extends off-site approximately 1600 feet down gradient from the properties at concentrations
greater than MCLs. The off-site A-zone groundwater plume extends north from the Site to
Lome Way. The off-site groundwater plume in the B- and C-zones extends north from the
Site to several hundred feet north of Inverness Way. The off-site groundwater plumes
appear to be defined Monitoring well VM-1B at the far north eastern extent of the
monitoring well network detected 10 ppb TCE It appears that this may be part of the AMI
groundwater plume.
8. Adjacent Facility Gould AMI Semiconductors (AMI) formerly manufactured electronic
components at a site located at 3800 Homestead Road, Santa Clara. This site is immediately
east of and adjacent to the Siemens and Intersil Site. The underground waste handling
facilities formerly used by AMI included an acid neutralization system, a concrete sump and
a steel storage tank. TCE has been detected in the A-zone at the AMI facility, north of the
AMI facility, and beneath the Marchese property east of AMI, at concentrations up to 300
ppb. TCE has been detected off-site at concentrations up to 168 ppb. Additional
investigation is required to define the extent of the off-site AMI TCE groundwater plume.
AMI has proposed an interim remedial action system.
9. Deep Aquifer Investigation The former Marchese Well No. 2, a private, deep irrigation well
located approximately one-half mile down gradient from Siemens and Intersil, was found to
contain low levels (less than 30 ppb) of TCE, 1,1,1-TCA and Freon-113. In December 1986,
this well was camera logged and sealed by the Santa Clara Valley Water District to prevent
the further spread of pollutants through the well Camera logging showed that the well was
screened at three different intervals between 300 and 500 feet deep.
Siemens and Intersil have installed four deep aquifer monitoring wells to attempt to identify
which of the deeper aquifers screened by the former Marchese Well No. 2 contained VOCs.
Since 1987, TCE has been sporadically detected in two deep aquifer monitoring wells at
concentrations up to 1 ppb. TCE has not been detected in the deep aquifer wells for the last
three quarters. TCA has been detected in the deep aquifer monitoring wells at
concentrations up to 5 ppb. TCA has not been detected in the deep aquifer monitoring wells
for the last two quarters. Toluene has been detected at concentrations up to 42 ppb.
Toluene was detected at 20 ppb in one deep aquifer well during the last quarter. Any
requirement for additional deep aquifer monitoring wells will be based on the results of
future quarterly monitoring of the existing four deep aquifer monitoring wells.
10. Municipal Water Supply There are five active municipal wells within a one mile radius of
the Siemens and Intersil properties. Three of these wells are located in apparent down
gradient directions. All five wells are being monitored for volatile organic chemicals (VOCs)
by the Cities of Santa dan and Sunnyvale, dry of Santa Clara well No. 24, down gradient
approximately 3700 feet northeast of the site, has consistently shown 1 to 43 ppb Freon-113
and up to 16 ppb 1,1,1-TCA. No other pollutants have been detected in any of these wells
to date.
11. Interim Remedial Actions Siemens has been performing soil and groundwater interim
remedial actions at its property. A sou" vacuum extraction system to remove volatile organics
from tile vadose zone has been in operation since November 1983, and is estimated to have
removed approximately 13,200 pounds of VOC*. Siemens installed an A-zone groundwater
extraction and treatment system in 1986. A combined A-zone and B-zone groundwater
extraction and treatment system has been operating since 1987. Siemens' groundwater
extraction systems have removed approximately 590 pounds of VOCs. Intersil has also been
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performing soil and groundwater interim remedial actions at its site. A soil vacuum
extraction system has been in operation since 1988, and is estimated to have removed
approximately 2,300 pounds of TCE An A-zone groundwater extraction and treatment
system has been in operation since 1987, and is estimated to have removed approximately 43
pounds of TCE.
12. Baseline Public Health Evaluation A Baseline Public Health Evaluation (BPHE) was
conducted for the site to evaluate current and potential future health risks posed by the site.
Current risks are based on exposures that are presently occurring. Potential future health
risks are based on exposures that could potentially occur in the future if residential
development occurred on the Site or if untreated shallow zone groundwater was used for
human consumption. To ensure that human health is protected, tine BPHE incorporated
conservative assumptions. Therefore, it is very unlikely that the actual risks posed by the
Site would be greater than estimated. Average case and plausible maximum case scenarios
are presented in the BPHE. This finding refers to the average case scenarios using a nine
year duration exposure. Current exposures include ingestion of water from City of Santa
x Clara Well No. 24, inhalation of VOCs from the use of water from City of Santa Clara Well
No. 24, and inhalation of chemicals volatilized from on-site soils. Freon 113 and TCA have
been detected in Well No. 24 at average concentrations of 1.7 ppb and 1.0 ppb, respectively.
These concentrations correspond to a noncarcinogen hazard index of 10*. This is 10,000
times less than tine maximum acceptable hazard index of one. The carcinogenic risk from
inhalation of chemicals volatilized from on-site soils is ID11. This is. 100,000 times less than
the maximum acceptable carcinogenic risk range of 10* to 104. The hazard index for
inhalation of VOCs volatilized from on-site soils is less than one. The BPHE concluded that
with respect to current exposure scenarios, risks were well below acceptable levels.
Potential future use exposures include direct contact with on-site soils, ingestion of shallow
and deeper zone groundwater, inhalation of VOCs from use of shallow or deeper zone
groundwater, and inhalation of chemicals volatilized from on-site soils. The carcinogenic risk
for direct contact with on-site soils for children and adults is 3 x 10* and 2 x 107,
respectively, and the noncartinogenic hazard index is less than one. The carcinogenic risk
from ingestion of shallow and deeper zone groundwater ranges from 1 x 10* to 4 x 10*. The
noncarcinogenic hazard index for ingestion of A-zone groundwater was greater than one.
The carcinogenic risk from inhalation of VOCs from the use of shallow or deeper zone
groundwater ranges from 2 x 104 to 7 x I04 and tine noncarcinogenic hazard index is less
than one. The carcinogenic risk from inhalation of chemicals volatilized from on-site soils is
10". The hazard index for inhalation of VOCs volatilized from on-site soils is less than one.
13. Description of Alternatives Siemens and Intersil evaluated several alternatives for tine final
Remedial Action Plan in the FS. In the PS, a wide range of technologies were initially
screened based on effectiveness, implementability, and relative cost The technologies that
passed this initial screening were then assembled into the range of treatment alternatives that
are described below.
The Siemens and Intersil properties are proposed as one site on the National Priorities List
(NPL). However, each company completed its own on-site RI/FS and together, they
completed a joint off-site RI/FS. For this reason, a separate series of alternatives was
developed for Siemens on-site, Intersil on-site and tine off-site area. The on-dte areas are tine
areas within tine leased property boundaries.
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13.1 .Siemens On-Site Alternatives
13.1.1 Alternative No. 1 is the "no action* alternative. All existing interim remedial actions are
discontinued and no further remedial actions are implemented. Geanup levels would not be
achieved for an estimated 750 to 1250 years when chemical concentrations might be reduced
by natural attenuation.
13.1.2 Alternative No. 2 includes groundwater extraction and treatment and soil vapor extraction
and treatment Groundwater treatment is accomplished by air stripping with subsequent
discharge to Calabazas Creek and possible partial on-site reuse. Soil vapor treatment is
accomplished through carbon adsorption. The existing groundwater extraction system of
extraction wells HXA, H2A, 3-DD, 3-XA, 1-1D, H-3B, H-5B, and 3EB would be expanded to
include LF-6A for a total of 9 groundwater extraction wells, 6 A-zone extraction wells and 3
B-zone extraction wells. However, 4 A-zone wells are currently dry due to the lowering
water table, so there would only be a total of 5 operating groundwater extraction wells. The
other 4 wells would be operated if regional groundwater levels rise. The estimated
groundwater pumping rate is 25 gallons per minute (gpm). Groundwater cleanup levels are
federal or state MCLs or action levels. The estimated time to achieve cleanup is
approximately 55 to 95 years.
The existing soil vapor extraction system of extraction wells ID, 3A, and 3C would be
expanded to include 12 additional soil vapor extraction wells; 2EP, 2EPa, 2B, 4BP, HMSA1,
HMSA2, SW-5, SW-6, SW-7, 3E, II, and 1M; for a total of 15 soil vapor extraction wells. The
estimated soil vapor vacuum rate is 400 cubic feet per minute (cfm). The soil cleanup level is
1 ppm total VOCs and 10 ppm total SOCs. The time to achieve soil cleanup is
approximately 15 years. The 30 year present worth cost for this alternative is $4.87 million.
Regular groundwater and soil vapor monitoring will be completed
13.1.3 Alternative No. 3 includes accelerated groundwater extraction and treatment and soil vapor
extraction and treatment Alternative No. 3 is the same as alternative No. 2 with the
addition of 4 A-zone extraction wells; W21A, LF-4A, LF-9A, and 2-1D-, for a total of 13
groundwater extraction wells: 10 A-zone and 3 B-zone groundwater extraction wells. 4 A-
zone wells are currently dry so there would be 6 operating A-zone extraction wells. The
additional extraction weDs would add about 3 gpm for a total system pumping rate of 28
gpm. The time to achieve groundwater cleanup is approximately 45 to 85 years. The 30
year present worth cost for this alternative is $5.03 million.
13.1.4 Alternative No. 4 includes accelerated groundwater extraction and treatment; soil vapor
extraction and treatment and sofl excavation. Alternative No. 4 is the same as alternative
No. 3 with the addition of soil excavation down to about 40 feet deep in the areas of former
tanks 1 and 3 to remove sous containing semi-volatile organic compounds (SOCs) above the
cleanup level of 10 ppm total SOCs. Trichlorobenzene and Phenol were detected in former
tank areas 1 and 3. These compounds are not readily amenable to treatment by soil vapor
extraction so these areas will be excavated. Two areas of 9 square feet by 40 feet deep or an
estimated 20 cubic yards of soil wfll be excavated at each location. The soil would be
disposed of in accordance with law, possibly at a Class I landfill or off-site treatment facility.
The estimated time to achieve son cleanup is 10 yean. The 30 year present cost for this
alternative is $5.66 million.
13.15 Alternative No. 5 includes accelerated groundwater extraction and treatment, accelerated soil
vapor extraction and treatment and soil excavation. Alternative No. 5 is the same as
alternative No. 4 with the addition of 7 soil vapor extraction wells beyond the system
proposed for alternatives 2, 3, and 4. There would be a total of 22 soil vapor extraction
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wells. The additional soil vapor extraction wells are 2C, SW-I, SW-2, 1H, IG, 1J, and HMSA-
3. The estimated soil vapor vacuum rate is 800 cubic feet per minute (cfm). The time to
achieve soil cleanup is approximately 10 years. The 30 year present worth cost of this
alternative is $636 million. : '• :'
13.1.6 Alternative No. 6 is the same as alternative No. 4 with a more stringent groundwater cleanup
level of cleanup to background levels for VOCs. The estimated time to achieve groundwater
cleanup is approximately 450 years.
13.2 Intersil On-Site Alternatives
13.2.1 Alternative No. 1 is the "no action" alternative. All existing interim remedial actions are
discontinued and no further remedial actions are implemented. Site monitoring would be
continued. The 30 year present worth cost of this alternative is $4.0 million. Geanup levels
would not be achieved
13.2.2 Alternative No. 2 consists of the existing groundwater extraction and treatment and soil
vapor extraction and treatment Groundwater treatment is accomplished by air stripping with
subsequent discharge to Calabazas Creek. Soil vapor treatment is accomplished through
carbon adsorption. The existing groundwater extraction system consists of extraction wells
W4A, W5A, W10A, W12A, and W17A, The groundwater pumping rate is 1.75 gallons per
minute (gpm). Groundwater cleanup levels are federal or state MCLs or action levels. The
estimated time to achieve groundwater cleanup is approximately 135 years.
The existing soil vapor extraction system consists of extraction wells VE1, VE2, VE3, and VE4.
The estimated soil vapor vacuum rate is 60 cubic feet per minute (cfm). The soil cleanup
level is 1 ppm total VOCs. The time to achieve soil cleanup is 7 years. The 30 year present
worth cost for this alternative is $ 9.8 million. Regular groundwater and soil vapor
monitoring will be conducted.
13.23 Alternative No. 3 includes expanded groundwater extraction and treatment and expanded soil
vapor extraction and treatment Alternative No. 3 is similar to alternative No. 2 with the
addition of 1) new groundwater extraction pumps having lower pump intakes installed in A-
zone extraction wells W5A, W10A, WI2A, and VV17A; 2} conversion of A-zone monitoring
well W9A into an A-zone extraction well and conversion of B-zone monitoring well W18B
into a B-zone extraction well; 3) four new vapor extraction wells and four new vent wells;
and 4) capping six existing and two new vent wells along Forge Drive. Two new vapor
extraction wells would be installed near the center of the site and perched-zone groundwater
extraction well W4A would be converted to a dual soil vapor / groundwater extraction well
and the dry groundwater monitoring well W4AA would be converted to a soil vapor
extraction well The groundwater extraction flow rate for this alternative is approximately 85
gpm. The time to achieve groundwater cleanup is 60 years. The soil vapor extraction flow
rate is 140 cfm. The time to achieve soQ cleanup is 5 years. The 30 year present worth cost
of this alternative is $10.1 million.
112.4 Alternative No. 4 includes expanded groundwater extraction and treatment and expanded soil
vapor extraction and treatment and on-tite reinjection of treated groundwater. Alternative
No. 4 is the same as alternative No. 3 with the addition of two A-zone groundwater injection
wells and two new piezometers to monitor the effect of reinjection. The time to achieve
groundwater cleanup is 45 years. The 30 year present worth cost of this alternative is $10.7
million.
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13.15 Alternative No. 5 includes expanded groundwater extraction and treatment, expanded soil
vapor extraction and treatment, extensive soil excavation, groundwater reinjection, and
installation of a slurry wall around the property down to the A/B aquitard. Alternative No. 5
is the same as alternative No. 4 with the addition of 1) the excavation and on-site aeration of
up to 170,000 cubic yards of soil; 2) installation of a slurry wall around the property and
completed within Ac A/B aquitard to physically aid in containing perched and A-zone
groundwater beneath the property. Alternative No. 5 maintains the existing soil vapor
extraction system and does not modify the soil vapor extraction system as in alternative nos.
3 and 4. The time to achieve groundwater cleanup is 20 years. The time to achieve soil
cleanup (largely through excavation) is 1 year. The 30 year present worth cost of this
alternative is $373 million.
13.2.6 Alternative No. 6 is the same as alternative No. 3 with a more stringent groundwater cleanup
level of cleanup to background levels for VOCs. The estimated time to achieve groundwater
cleanup is several hundred years. The 30 year present worth cost of this alternative is $10.6
million.
13.3 Intersil and Siemens Off-Site Area
133.1 Alternative No. 1 is the 'no action* alternative All existing interim remedial actions are
discontinued and no further remedial actions are implemented. Site monitoring would be
continued. The 30 year present worth cost of this alternative is $122 million. Geanup levels
would not be achieved except through natural attenuation which would take an estimated
750 to 1250 years.
133.2 Alternative No. 2 consists of groundwater extraction from B-zone extraction well LQ-2B and
treatment Groundwater would be pumped from LQ-2B on Lanark Ct south on Quail Ave.
to the Siemens property. Groundwater treatment is accomplished by on-site air stripping
with subsequent discharge to Calabazas Creek and possible partial on-site reuse. The
estimated groundwater pumping rate is 40 gallons per minute (gpm). Groundwater cleanup
levels are federal or state MCLs or action levels. The estimated time to achieve cleanup is
approximately 20 to 50 years. The 30 year present worth cost for this alternative is $2.12
million. Regular groundwater monitoring will be conducted
1333 Alternative No. 3 consists of groundwater extraction from three B-zone extraction wells and
groundwater treatment and a contingency for one C-zone extraction well Alternative No. 3
is the same as alternative No. 2 with the addition of groundwater extraction from wells LQ-
1B and S-2B. Groundwater modeling has shown that pumping from the B-zone will capture
a portion of the C-zone groundwater at concentrations greater than MCLs. C-zone capture
area and water chemistry will be evaluated after 1 year of operation to determine the
effectiveness of this alternative. If adequate C-zone capture and a reduction in C-zone TCE
concentrations are not demonstrated, then a C-zone extraction well will be installed. The
estimated groundwater pumping rate is 105 gpm. The estimated time to achieve cleanup
levels is 20 to 45 years. The 30 year present worth cost for this alternative is $2.99 million.
133.4 Alternative No. 4 consists of groundwater extraction from two B-zone and one C-zone
extraction well and groundwater treatment Alternative No. 4 is the same as alternative No.
3 with the addition of groundwater extraction from C-zone weU RK-2C For the C-zone
extraction well, groundwater would be pumped by underground pipeline from RK-2C on
Kerry Ave., south along Redwing Ave. and then west along Lome Way to Quail Ave. and
then to the Siemens facility. The estimated groundwater pumping rate is 65 gpm. The
estimated time to achieve deanup levels is 20 to 50 years. The 30 year present worth cost for
this alternative is $165 million.
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1S.S.5 Alternative No. 5 consists of ground water extraction from two B-zone and two C-zone
extraction wells and ground water treatment Alternative No. 5 is the same as alternative No. 4
with the addition of groundwater extraction from C-zone well LR-SC. The estimated
groundwater pumping rate is 90 gpm. The estimated time to achieve cleanup levels is 20 to 50
years. The SO year present worth cost for this alternative is $2.81 million.
13.3.6 Alternative No. 6 is the same as alternative No. 4 with a more stringent groundwater cleanup
level to background levels for VOCs. The estimated time to achieve cleanup levels is 1 50 to
300 years. The 30 year present worth cost for this alternative is $2.96 million.
14. Summary of Evaluation Criteria This section summarizes the nine evaluation criteria
developed by EPA and used to compare the alternatives in the RI/FS. The alternatives were
evaluated in detail with respect to the nine criteria in the RI/FS report Each alternative was
also evaluated with respect to the six state law criteria set forth in Section 25356.1 of the
California Health and Safety Code. A comparative analysis was completed in the RI/FS.
14.1 Overall protection of human health and the environment This criterion addresses whether a .
remedy provides adequate protection of human health and the environment
14.2 Compliance with applicable or relevant and appropriate requirements (ARARs) This criterion
addresses whether a remedy will meet all of the ARARs or other Federal and State
environmental laws enumerated in the RI/FS.
14 .3 Long-term effectiveness and permanence This criterion refers to expected residual risk and
residual chemical concentrations after cleanup goals have been met and the ability of a remedy
.; to maintain reliable protection of human health and the environment over time.
14.4 Reduction of toxicity. mobility or volume This criterion refers to the anticipated performance
of the treatment technologies a remedy may employ.
14.5 Short-term effectiveness This criterion addresses the period of time needed to achieve cleanup
and any adverse impacts on human health and the environment that may be posed during the
construction and implementation period, until cleanup goals are achieved.
14.6 Implementability This criterion refers to the technical and administrative feasibility of a
remedy.
14.7 Cost Tub criterion includes estimated capital and operation and maintenance, usually
presented in a SO year present worth format
14.8 Support Agency Acceptance This criterion addresses EPA's acceptance of the selected remedy
and any other EPA comments.
14.9 Community Acceptance This criterion summarizes the public's general response to the
alternatives.
15. The Selected Remedy fffaal ttgm^*fia| Action pfa"^
15.1 Intersil On-Site Area The selected remedy for the Intersil on-site area is Alternative No. 3.
Alternative No. S includes expanded groundwater extraction and treatment and expanded soil
vapor extraction and treatment. The existing sofl vapor extraction system consisting of
extraction wells VE1, VE2, VES, and VE4 will be expanded to include four new vapor
extraction wells and four new vent wells. Six existing and two new vent wells along Forge
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Drive will be capped The existing groundwater extraction system consisting of extraction
wells W4A, W5A, WlOA, W12A, «nd W17A will be upgraded to include, new groundwater
extraction pumps having lower pump intakes installed in A-zone extraction wells W5A,
WlOA. W12A, and W17A, and A-zone monitoring well W9A will be converted to an
extraction well. B-zone groundwater extraction will be accomplished through conversion of
B-zone monitoring weD W18B into a B-zone extraction well
Groundwater cleanup levels are federal or state MCLs (adopted or proposed) or California
Department of Health Services (DHS) Recommended Drinking Water Action Levels
(RDWALs). The soil cleanup level is 1 ppm total VOCs. The final cleanup levels for the
suite of chemicals detected in the A-zone equate to a future use scenario risk level for
groundwater ingestion and inhalation of VOCs of 1.7 x 10*. Groundwater treatment will be
accomplished by air stripping with subsequent discharge to Calabazas Creek. Soil vapor
treatment is accomplished through carbon adsorption. Regular groundwater and soil vapor
monitoring will be conducted The time to achieve groundwater cleanup is 60 years, the
time to achieve soil cleanup is 5 years.
152 Siemens On-Site Area The selected remedy for the Siemens on-site area is Alternative No. 4.
Alternative No. 4 includes accelerated groundwater extraction and treatment, soil vapor
extraction and treatment, and soil excavation. The existing groundwater extraction system of
extraction wells HXA, H2A, 3-DD, 3-XA, MD, H-3B, H-5B, and 3EB would be expanded to
include LF-6A, LF-4A, LF-9A, W21A, and MD; for a total of 10 A-zone groundwater
extraction wells and 3 B-zone extraction wells. However, 4 A-zone wells are currently dry
due to the lowering water table, so there would only be a total of 6 operating A-zone
groundwater extraction wells under current conditions.
The existing soil vapor extraction system of extraction wells ID, 3A, and 3C would be
expanded to include 12 additional soil vapor extraction wells; 2EP, 2EPa, 2B, 4BP, HMSA1,
HMSA2, SW-5, SW-6, SW-7, 3E, H and 1H for a total of 15 soil vapor extraction wells.
Alternative No. 4 also includes soil excavation down to about 40 feet deep in the areas of
former tanks 1 and 3 to remove soils containing semi-volatile organic compounds (SCO).
The soil would be disposed of in accordance with applicable laws, possibly at a Class I
landfill or off-site treatment facility. The 30 year present cost for this alternative is $5.66
million.
Groundwater cleanup levels are federal or state MCLs (proposed or adopted) or RDWALs.
The final cleanup levels for the suite of chemicals detected in the A-zone equate to a future
use scenario risk level for groundwater ingestion and inhalation of VOCs of 1 x 104.
Groundwater treatment will be accomplished by air stripping with subsequent discharge to
Calabazas Creek and possible partial reuse and reclamation on-site. Soil vapor treatment may
be accomplished through carbon adsorption. Regular groundwater and soil vapor monitoring
will be completed The soO cleanup level is 1 ppm total VOCs and 10 ppm total SOCs. The
estimated time to achieve groundwater cleanup is 45 to 85 years. The time to achieve soil
cleanup is approximately 11 yean. Regular groundwater and soil vapor monitoring will be
conducted.
153 Siemens / Intersil Off-Site Area The selected remedy for the Siemens / Intersil off-site area is
Alternative No. 3. Alternative No. 3 consists of groundwater extraction from three B-zone
extraction wells and groundwater treatment Groundwater would be pumped from wells LQ-
1B, LQ-2B and S-2B. C-zone groundwater would be captured by pumping LQ-1B and LQ-
2B. If C-zone groundwater concentrations do not show a reduction during the first one year
period, and if sufficient C-zone capture is not demonstrated, RK-2C will be converted into a
C-zone extraction weJL
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Groundwater cleanup levels are federal or state MCLs (proposed or adopted) or RDWALs.
The final cleanup levels for the suite of chemicals detected in the B-zone. equate to a future
use scenario risk level for groundwater ingestion and inhalation of VOCs of 1 x 1CH.
Groundwater treatment will be accomplished by air- stripping with subsequent discharge to
Calabazas Creek and possible partial reuse and reclamation on-site. Regular groundwater
monitoring will be completed The estimated time to achieve groundwater cleanup is 20 to
45 years.
15.4. Uncertainty in Achieving Geanup Goals The goal of this remedial action is to restore
groundwater to its beneficial uses Based on information obtained during the RI and on a
careful analysis of all remedial alternatives, the Board believes that the selected remedy will
achieve this goal However, studies suggest that groundwater extraction and treatment will
not be, in all cases, completely successful in reducing contaminants to health-based levels in
the aquifer zones. The Board recognizes that operation of the selected extraction and
treatment system may indicate the technical impracticability of reaching health-based
groundwater quality standards using this approach. If it becomes apparent, during
implementation or operation of the system, that contaminant levels have ceased to decline
and are remaining constant at levels higher than the remediation goal, that goal and the
remedy may be reevaluated.
The selected remedy will include groundwater extraction for a period of 45 to 85 years,
during which tine system's performance will be carefully monitored on a regular 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;
b) alternating pumping at wells to eliminate stagnation points; and
c) pulse pumping to allow aquifer equilibration and encourage adsorbed
contaminants to partition into groundwater.
155. Change to the RI/FSs The RVFSs state that State Board Resolution 68-16, 'Statement of Policy
with Respect to Maintaining High Quality Waters in California/ is a To Be Considered"
requirement The RI/FSs are hereby changed to state that Resolution 68-16 is an ARAR.
16. Remedy Selection Rationale and Statutory Determinations The selected remedies are
protective of human health and the environment Groundwater contamination is treated so
that the remaining potential future risks fall within the 10* to 10* carcinogenic risk range for
acceptable cleanup levels. The remedies comply with ARARs by achieving cleanup to at least
Federal and State MCLs (proposed or adopted) or RDWALs. Soil is remediated to a level
that wfll protect groundwater from future solvent contamination.
The selected remedies are cost effective in achieving the required cleanup levels. Siemens'
on-site alternative No, 5 and Intersil's on-site alternatives No. 4 and 5 are more costly and
these alternatives could have potentially spread the soil pollution further through
groundwater injection or sofl vapor extraction at the periphery of the soil pollution. The
potentially shorter deanup times of these more costiy alternatives does not justify their
selection based on the potential problems associated with these alternatives. Intersil's on-site
alternative No. 5 is too costiy to justify the additional slurry wall control and the large scale
sofl excavation. Off-site alternatives No. 4 and No. 5 are more costiy than off-site alternative
No. 3. Off-site alternatives No. 4 and 5 may potentially draw groundwater deeper from the
11
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•B-zone to the C-zone due to C-zone pumping and would also be more disruptive to the >
neighborhood due to additional trenching and construction activities. Alternative No. 3 has
been modeled to capture the off-site B-zone plume and a significant portion of groundwater
containing concentrations greater than MCLs. For these reasons, alternative No. 3 was
selected The alternatives for cleanup to background concentrations were not selected
because of the increased time and cost necessary to achieve background concentrations and
because of the need to minimize groundwater pumping and conserve groundwater supplies.
The selected remedies are effective in the short-term with cleanup times for soil of 5 years to
11 years and in groundwater from 45 years to 85 years. The selected remedies are effective
in the long-term by virtue of the fact that ARARs are achieved Soil vapor extraction and
treatment and groundwater extraction and treatment are permanent solutions and
significantly reduce pollutant toxicity, mobility and volume at the site. The selected off-site
alternative. No. 3, will not require the approximately 1000 feet of street trenching and piping
that would be required by alternative No. 4. All of the alternatives are implementable, EPA
has preliminarily approved the selected remedy.
Treatment is used as a principal element for the remedies. Emissions from soil vapor
extraction will be treated by vapor phase carbon adsorption with the carbon canisters being
regenerated off-site. Emissions from air stripping towers will meet local air district
requirements, which are anticipated to be less than a 10* risk level, or will be required to
implement vapor phase carbon treatment
17. NFDES Discharge The extracted groundwater is treated by air stripping and then discharged
to a storm sewer system tributary to Calabazas Creek. Currently, approximately 35,000
gallons per day (gpd) of groundwater is discharged by Siemens under NPDES Permit
#CA0029190 and 2,000 gpd is discharged by Intersil under NPDES Permit * CA0029261
Calabazas Creek is tributary to South San Francisco Bay. Intersil's permit expires on
October 21, 1991 Siemens' permit expires on April 1, 1991 The dischargers must file a
Report of Waste Discharge in accordance with Title 23, Code of California Regulations, not
later than 180 days in advance of the expiration date as application for issuance of new
waste discharge requirements.
18. Cleanup Standards The groundwater cleanup standards for the site are Environmental
Protection Agency (EPA) MCLs (proposed or adopted), California Department of Health
Services (DHS) MCLs (proposed or adopted), DHS RDWALs. The soil cleanup standards are
1 ppm total VOCs and 10 ppm total SOCs. These cleanup standards are defined in
Specification B.4.
Groundwater extraction will continue until drinking water quality is achieved, if feasible. If
these standards are determined to be infeasible, groundwater extraction shall continue as
long as significant quantities of chemicals are being removed through groundwater extraction.
Achieving drinking water quality is an ARAR for this site. If drinking water quality cannot
be achieved, the dischargers must demonstrate to the satisfaction of the Regional Board that
the conditions for waiving an ARAR are met (e.g., that meeting the ARAR is technically
impracticable from an engineering perspective) and that the alternative proposed will be
protective of human health and the environment The Order will then need to be modified
by the Regional Board and approved by EPA to allow a less stringent groundwater cleanup
level
19. Risk Associated With Cleanup Standards The selected remedy is protective of human health
and the environment - as required by Section 121 of CERCLA - in that pollution in
groundwater is treated to at least maximum contaminant levels (MCLs) and falls within
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EPA's acceptable carcinogenic risk range and sttncarcinogenic hazard index range. EPA
considers a carcinogenic risk range of I04 to 10* as an acceptable cleanup level If the
noncarcinogenic hazard index is less than one. EPA considers the combined intake of
chemicals unlikely to pose a health risk.
The carcinogenic risk at the cleanup levels associated with the potential future me scenario
of groundwater ingestion and inhalation of VOCs from grbundwater ranges fro» 1 x 104 to
17 x 10* for the on-ote and off-site areas, in cleaning up TCE to the 5 ppb cleanup
standard, it is quite likely that the concentrations of other VOCs will be reduced to levels in
the 5 ppb range. These risks were calculated using a potential future use scenario with a 30
year duration exposure.
' • *
In the Ozone, there has been no PCE detected; 1,1-dlchJoroethene (1,1-DCE) was detected at
1 ppb, and TCE was detected at 17 ppb as of the May 11,1990 sampling event Using the
cleanup level of 5 ppb TCE and assuming that 1,1-DCE will be reduced to the detection limit
of 0.5 ppb, the concentrations of 5 ppb TCE and 05 ppb 1,1-DCE equate to a carcinogenic
risk of 13 x 10* using the ingestion and inhalation pathways. This is 0.13 times less than
the 10* risk level and 13 times greater than the 104 risk level
, fs.
The noncancer hazard indices associated with the cleanup levels range from 0.0 to 0.4 for the
on-site and off-site areas. The method and assumptions used to obtain the Carcinogenic Risk
and the Hazard Index associated with the deanup standards are contained in the RI/FS and
the BPHE. The deanup standards for the site are protective of human health, have a
carcinogenic risk that falls within a range of 10* to 10*, and a hazard index of less than one.
20. future Changes to Cleanup Standards If new information indicates cleanup standards cannot
be attained or can be surpassed, the Board and EPA will decide if further final deanup
actions, beyond those completed, shall be implemented at this Site. If changes in health
criteria, administrative requirements, site conditions, or remediation efficiency occur, the
discharger will submit an evaluation of the effects of these changes on deanup standards as
defined in Specification B.4.
4
The Regional Board recognizes that the discharger has already performed extensive
investigative and remedial work onsite and that the discharger is being ordered hereby to
perform additional remedial tasks. It is in the public interest to have the discharger
undertake such remedial actions promptly and without prolonged litigation or the
expenditure of public funds. The Regional Board recognizes (hat an important element in
encouraging the discharger to Invest substantial resources in undertaking such remedial
actions is to provide the discharger with reasonable assurances that the remedial actions
called for in this Order will be the final remedial actions required to be undertaken by the
discharger. On the other hand, the Regional Board also recognizes its responsibility to
protect water quality, public health, and the environment and that future developments could
indicate that some additional remedial actions may be necessary.
The Regional Board has considered and balanced these important considerations, and has
determined that the remedial actions ordered herein represent the Regional Board's best,
current judgement of the remedial actions to be required of the discharger. The Regional
Board will not require the discharger to undertake additional remedial actions with respect to
the matters previously described herein unless: (1) conditions on the site, previously
unknown to the Regional Board, are discovered after adoption of this Order, or (2) new
information is received by the Regional Board, in whole or in part after the date of this
Order, and these previously unknown conditions or this new information indkates that the
remedial actions required in this Order may not be protective of public health and the
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environment The Regional Board will also consider technical practical^, cost effectiveness,
State Board Resolution No. 68-16 and other factors evaluated by the Re£bnal Bovd in
issuing this Order in determining whether such additional remedial actions are appropriate
and necessary.
21. Groundwater Conseivan'on Siemens and Intersil have considered the fusibility of
reclamation, reuse, or discharge to a publicly owned treatment works (fOTW) of treated,
extracted groundwater, as specified in Board Resolution No. 88-160. Ike Cry of Cupertino
will not accept the discharge of treated groundwater for remediation pvposes n*> their
sanitary sewer system. Regarding on-tite process water reuse, the Inteofl facility is no longer
operating and the Siemens facility process would consume a small percentage of the extracted
groundwater. Both properties are mostly paved and use small amounts of irrigsf on water.
Groundwater reinjection was evaluated but was determined to have the potential to spread
VOCs in the vadose zone, that fouling or dogging of the injection well may occur and was
costly to implement Capital costs for reinjection were $286/100 versus $11,000 for discharge
to Calabazas Creek. Irrigation or reuse is presently being further evaluated.
Calabazas Creek is generally a dry creek bed in the area of the treated effluent dbcharge. It
appears that all the groundwater discharge is currently being naturally recharged through
Calabazas Creek. The companies are currently completing a recharge study of Calabazas
Creek which will be submitted on October 30, 1990. This report will ako evaluate off-site
irrigation and reuse.
22. Community Involvement An aggressive Community Relations program has beea ongoing for
ail Santa Clara Valley Superfund sites, including the Intersil/Siemens site. The Board
published a notice in the San Jose Mercury News, the Santa Clara Weekly and tie Valley
journal on June 13, 1990, announcing the proposed final RAP and opportunity far public
comment at the Regional Board Public Hearing of June 20, 1990 in Oakland. A presentation
of the final cleanup plan was made at the June Board Hearing. The 30 day cement period
was from June 13, 1990 to July 13, 1990. The June 13, 1990 notice also announced an
evening public meeting held at the Laurelwood Elementary School in Ac Cry of Santa Clara
on 'June 21, 1990. A presentation on the final cleanup plan was also s*ade at the June 21,
1990 public meeting. Public comment did not generate any significant changes to the
proposed plan.
Fact Sheets were mailed to interested residents, local government officials, and stedia
representatives. Fact Sheet 1, mailed in July 1989, summarized the pollution problem, the
results of investigations to date, and the interim remedial actions. Fact sheet 2, mailed in
January 1990, provided written answers to questions from the public asked at the September
27, 1989 community meeting. Fact Sheet 3, mailed on June 7, 1990, described the cleanup
alternatives evaluated, explained the proposed final RAP, announced opportunities for public
comment at the Regional Board Hearing of June 20, 1990 in Oakland and the Public Meeting
of June 21, 1990 in Santa Can, and described the availability of further information at the
Information Repository at the Sunnyvale Public Library.
Fact Sheet 4, to be mailed in October 1990, will explain the final adopted cleans? plan
contained in this Order.
23. Stare Board Resolution 68-16. "Statement of Policy with Respect to Mftjnftipjf g High Quality
Waters in California* On October 28, 1968, the State Water Resources Control Board adopted
Resolution No. 68-16, "Statement of Policy with Respect to Maintaining High Quality Waters
in California*. This policy calls for maintaining the existing high quality of Sttr waters
• unless it is demonstrated that any change would be consistent with the maxinun public
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benefit and not unreasonably affect beneficial uses, the origBsJ discharge of waste to the
groundwater at this Site was in violation of this policy, therefcse, the groundw*rr quality
needs to be restored to its original quality to the extent reasceafele. For the purpose of
establishing cleanup objectives, the shallow groundwater at the site is designated a potential
source of drinking water. The FS included alternatives that eashuted cleanup to background
or non-detect levels. These alternatives greatly increased the fce required to reach cleanup
levels. For example, the Siemens on-site groundwater cleanup toe increased fmn
approximately 85 yean to 450 yean. Cleanup of groundwater to below the MCL for TCE
may be unachievable due to the difficulties in restoring aquifcss to concentratkm below 5
ppb for any VOC This is due to tile slow desorption of VOCs adsorbed to the inner pore
spaces of soil partides which make up the aquifer and VOCs adsorbed to clays and organic
matter in the aquitard For this reason, the MCLs were accepted as concejttraliDns that meet
the intent of Resolution 68-16.
24. Data Validation Development of the Board's final Remedial Action Plan was based on the
Board's evaluation of eight yean of water and soil quality data. Random samples have been
collected and analyzed by the Board to confirm the validity of data generated by the
dischargers. Data has been validated using EPA validation gvdance. The Board finds that
there is sufficient acceptable data to make cleanup decisions.
25. Lead Agency Pursuant to the South Bay Multi-Site Cooperative Agreement and the South
Bay Ground Water Contamination Enforcement Agreement, estered into on May 2, 1985 (as
subsequently amended) by the Regional Board, EPA and DHS. the Regional Board has been
acting as the lead agency. EPA is expected to agree with the selected remedy and. issue a
Record of Decision following adoption by the Regional Board of the remedial action plan.
The Regional Board will continue to regulate the dischargers' remediation and administer
enforcement actions inaccordance with CERCLA as amended by SARA, the Caifomia Water
Code, Health and Safety Code, and regulations adopted there under.
26. Administrative Record The Administrative Record has been prepared in accordance with EPA
Guidance, has been made available for public and PRP review, and provides the backup
documentation for the recommendations of staff and decisions by the Board
27. Siemens and Intersil are responsible parties under the federal Superfund (CERCLA/SARA).
The Siemens and Intersil properties are jointly proposed as a Superfund site c* the National
Priorities List
28. This Order is written as a joint Order for Siemens and Inters!] because the groundwater
pollution plumes from both Companies have commingled in the A-zone and because tine two
properties are proposed as one site on the National Priorities List Siemens aad Intersil are
encouraged to submit joint reports. If joint reports are not coordinated and admitted, each
company is still individually responsible for die joint tasks in this Order.
29. Siemens Components, Inc. (hereinafter referred to as a discharger) is a discharger because of
the releases of chemicals that have resulted from its waste handling facilities. Intersil
(hereinafter referred to as a discharger) is a discharger because of the releases of chemicals
that have resulted from its waste handling facilities. Vallco Park, Ltd (hereinafter referred to
as a discharger) is a discharger because it is the current owner of the property where these
releases have occurred
30. The selected remedial action plan for the Siemens and Intersil Site was choseat in accordance
with the Health and Safety Code Section 25356.1, the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA), as amended by the Superfund
15
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Amendments and Reauthorization Act (SARA), the National Oil and Hazardous Substances
Pollution Contingency (NCP), and pursuant to the Multi-Site Cooperative Agreement This
decision is based on the administrative record for the site.
31. The Board adopted a revised Water Quality Control Plan for the San Francisco Bay Basin
(Basin Plan) on December 17, 1986. The Basin Plan contains water quality objectives and
beneficial uses for South San Francisco Bay and contiguous surface and groundwaters.
32. The existing and potential beneficial uses of the groundwater underlying and adjacent to the
facilities include:
a. Industrial process water supply
b. Industrial service water supply
c Municipal and Domestic water supply
d Agricultural water supply
33. The dischargers have caused or permitted, and threaten to cause or permit waste to be
discharged or deposited where it is or probably will be discharged to waters of the State and
creates or threatens to create a condition of pollution or nuisance.
34. This action is an order to enforce the laws and regulations administered by the Board This
action is categorically exempt from the provisions of the CEQA pursuant to Section 15321 of
the Resources Agency Guidelines.
i
35. This Order supersedes and rescinds the Intersil, Siemens and Vallco Park, Ltd. Order No. 89-
038.
36. On-site and off-site containment and cleanup measures need to be implemented to alleviate
the threat to the environment posed by the continued migration of the groundwater plume
of organic solvents.
37. The Board has notified the dischargers and interested agencies and persons of its intent
under California Water Code Section 13304 to prescribe Site Qeanup Requirements for the
discharge and has provided them with the opportunity for a public hearing and an
opportunity to submit their written views and recommendations.
38. The Board, in a public meeting, heard and considered all comments pertaining to the
discharge.
IT IS HEREBY ORDERED, pursuant to Section 13304 of the California Water Code and Section
25356.1 of the California Health and Safety Code, that Siemens Components, Inc. and Intersil, Inc.
and Vallco Park, Ltd. shall cleanup and abate the effects described in the above findings as follows:
A, PROHIBITIONS
1. The discharge of wastes or hazardous materials in a manner which wffl degrade
water quality or adversely affect the beneficial uses of the waters of the State is pro-
hibited.
2. Further significant migration of pollutants through subsurface transport to waters of
the State is prohibited
3. Activities associated with the subsurface investigation and cleanup which will cause
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significant advene migration of pollutants are prohibited.
B. SPECIFICATIONS
1. The storage, handling, treatment or disposal of toil or groundwater containing
pollutants shall not create a nuisance as defined in Section 13060(m) of the California
Water Code.
2. The dischargers shall conduct monitoring activities as determined by the Executive
Officer to define the current local hydrogeologic conditions, and the lateral and
vertical extent of soil and groundwater pollution. Should monitoring results show
evidence of plume migration, additional characterization of the pollutant plume may
be required.
3. All Siemens and Intersil wells shall be used to determine if cleanup standards have
been met
4. Final cleanup standards for all onsite and off-site wells shall not be greater than the
levels as provided in Finding 18. The numerical final cleanup standards, therefore,
shall not exceed the following in any well as set forth in the Self-Monitoring Plan:
Chemical
Groundwater Cleanup Standard
Basis
1989-90 Location
Max.(4)
POTENTIAL CARCINOGENS
1,1-Dichloroethylene (1,1-DCE)
Trichloroethylene (TCE)
Tetrachlorpethylene (PCE)
6
5
5
59
4700
5
LF-4A
LF-6A
W21A
NONCARCINOGENS
1,2-dichloroethylene (1,2-DCE)
cis
trans
1,1,1-trichloroethane (1,1,1-TCA)
Freon 113
Toluene
6
10
200
1,200
100-
1
1
1
1
2
3000 G-1A
NA(5)
700 3-DD
73 W19B
93 KB-1B
1 - California State Maximum Contaminant Level (MCL) for Drinking Water
(proposed or adopted).
2 - California State Recommended Drinking Water Action Level.
3 - California State Proposed MCL
4 - 1989-90 Maximum Concentration Levels (ug/I).
5 - Not Analyzed
If Ac State of California proposes or adopts a MCL for toluene, the MCL
shall at that time become the cleanup standard to toluene at this Site.
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4.1 The soil cleanup standards are 1 ppm total VOCs and 10 ppm total SOCs.
5. The discharger shall implement the final cleanup plan described in Finding 15.
6. Final chemical concentrations shall not be found to exceed the appropriate cleanup
level based on quarterly analytical results.
PROVISIONS
1. Siemens and Intersil shall submit to the Board acceptable monitoring program reports
containing results of work performed according to a the attached •elf-monitoring
program prescribed by the Board's Executive Officer.
2. This Order supersedes and rescinds the Intersil, Siemens and Vallco Park, Ltd. Order
No. 89-038.
3. Siemens and Intersil shall comply with Prohibitions A.I., A3. and A3., Specifications
B.I. and B.2. and Provisions Cl and C2 above immediately, except as modified in
accordance with the time schedule and tasks below. Within 60 days of the Executive
Officer's determination and actual notice to Vallco Park, Ltd. that Siemens and/or
Intersil have failed to comply with Prohibitions A.1, A2 and A3, Specifications B.I
and B.2 and Provisions Cl and C2 of this order, Vallco Park, Ltd., as landowner,
shall comply with these paragraphs and with the tasks below.
COMPLETION DATE/TASK
SIEMENS VADOSE ZONE AND A-ZONE ON-SITE AREAS
Siemens is responsible for the following tasks a. through f.
a. / COMPLETION DATE October 30, 1990
TASK: GROUNDWATER REUSE AND RECLAMATION: Submit a technical report
acceptable to the Executive Officer containing the groundwater reuse and reclamation
plan for the treated groundwater. The report shall include documentation of efforts
to reuse the water, efforts to secure users for the water, and reasons why potential
users would not accept the water and discuss the technical feasibility and cost-
effectiveness of other water reuse options. The report shall also include an
evaluation of the recharge capacity of Calabazas Creek.
b. COMPLETION DATE: May 31, 1991
TASK: START UP OF EXPANDED REMEDIAL ACTION PLAN: Submit a technical
report acceptable to the Executive Officer containing the start up report for the final
remedial action plan. This report shall contain the final construction schedule for the
time period from adoption of this order through submittal of the startup report, as-
built construction drawings of the system, and the first two weeks of monitoring
data.
c CURTAILING SOIL VAPOR OR GROUNDWATER EXTRACTION
1) COMPLETION DATE: 90 days prior to proposed curtailment of any soil vapor or
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groundwater extraction well or treatment system
TASK- ONSITE WELL PUMPING CURTAILMENT CRITERIA AND PROPOSAL
Submit a technical report acceptable to the Executive Officer containing a proposal
for curtailing pumping from any onsite groundwater or vapor extraction well(s) and
the criteria used to justify such curtailment This report shall include data to show
that groundwater or soil cleanup standards for all VOCs have been achieved and
pollutant levels have stabilized or ire stabilizing, and that the potential for pollutant
levels rising above cleanup standards is minimal.
If the discharger daims that it is not feasible to achieve cleanup standards, the report
shall evaluate the alternate standards that can be achieved
2) COMPLETION DATE; 60 days after the Board approves onsite curtailment
TASK: IMPLEMENTATION OF ONSITE CURTAILMENT: Submit a technical report
acceptable to the Executive Officer documenting completion of the necessary tasks
identified in the technical report submitted for Task cl). Tasks cl) and c2) may be
incorporated in the quarterly reports specified in Provision C9 of this Order.
d. COMPLETION DATE: July 31, 1995
TASK: FIVE-YEAR STATUS REPORT AND EFFECTIVENESS EVALUATION. Submit
a technical report acceptable to the Executive Officer containing die results of any
additional investigation; an evaluation of the effectiveness of installed final cleanup
measures and cleanup costs; additional recommended measures to achieve final
cleanup objectives and standards, if necessary; a comparison of previous expected
costs with the costs incurred and projected costs necessary to achieve cleanup
objectives and standards*, and the tasks and time schedule necessary to implement
any additional final cleanup measures. This report shall also describe the reuse of
extracted groundwater and evaluate and document the cleanup of polluted soil and
groundwater. If safe drinking water levels have not been achieved onsite and are
not expected to be achieved through continued groundwater extraction and/or soil
remediation, this report shall also contain an evaluation addressing whether it is
technically feasible to achieve drinking-water quality, and if so, a proposal for
procedures to do so.
e. COMPLETION DATE: 90 days after request made by the Executive Officer
TASK: EVALUATION OF NEW HEALTH CRITERIA. Submit a technical report
acceptable to the Executive Officer which contains an evaluation of how the final
plan and cleanup standards would be affected, if the concentrations as listed in
Specification B.4. change as a result of promulgation of drinking water standards,
maximum contaminant levels or action levels or other health based criteria.
f. COMPLETION DATE: 90 days after request made by the Executive Officer
TASK: EVALUATION OF NEW TECHNICAL INFORMATION. Submit a technical
report acceptable to the Executive Officer which contains an evaluation of new
technical and economic information which indicates that cleanup standards or
cleanup technologies in some areas may be considered for revision. Such technical
reports shall not be required unless the Executive Officer or the Board determines
that such new information indicates a reasonable possibility that the Order may need
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to be changed under the criteria described in Finding 20.
5. INTERSIL VADOSE ZONE AND A-ZONE ON-SITE AREAS
Intersil is responsible for the following tasks a. through f.
a. COMPLETION DATE: October 30, 1990
TASK: GROUNDWATER REUSE AND RECLAMATION: Submit a»ehnaal report
acceptable to the Executive Officer containing the groundwater raar *a* reclamation
plan for the treated groundwater. The report shall include doaaaatatiBR
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measures and cleanup costs; additional recommended measures to achieve final
cleanup objectives and standards, if necessary; a comparison of previous expected
costs with the costs incurred and projected costs necessary to achieve cleanup
objectives and standards; and the tasks and time schedule necessary to •tplement
any additional final cleanup measures. This report shall also describe the reuse of
extracted groundwater and evaluate and document the cleanup of polluted soil and
groundwater. If safe drinking water levels have not been achieved onsite and are not
expected to be achieved through continued groundwater extraction andAor soil
remediation, this report shall also contain an evaluation addressing whether it is
technically feasible to achieve drinking-water quality, and if so, a propocal for
procedures to do so.
• *
e. COMPLETION DATE: 90 days after request made by the Executive Officer
TASK: EVALUATION OF NEW HEALTH CRITERIA. Submit a technical report
acceptable to the Executive Officer which contains an evaluation of how the final
plan and cleanup standards would be affected, if the concentrations as fsted in
Specification B.4. change as a result of promulgation of drinking water standards,
maximum contaminant levels or action levels or other health based criteria.
f. COMPLETION DATE: 90 days after request made by the Executive Officer
TASK 15: EVALUATION OF NEW TECHNICAL INFORMATION. Submit a technical
report acceptable to the Executive Officer which contains an evaluation of new
technical and economic information which indicates that cleanup standards or
cleanup technologies in some areas may be considered for revision. Such technical
reports shall not be required unless the Executive Officer or the Board determines
that such new information indicates a reasonable possibility that the Order may need
to be changed under the criteria described in Finding 20.
SIEMENS B-ZONE AND DEEPER ZONES ON-SITE AREAS AND B-ZONE AND DEEPER
ZONES OFF-SITE DOWN GRADIENT AREAS
INTERSIL B-ZONE AND DEEPER ZONES ON-SITE AREAS AND B-ZONE AND DEEPER
ZONES OFF-SITE DOWN GRADIENT AREAS
INTERSIL AND SIEMENS OFF-SITE A-ZONE
Siemens and Intersil are responsible for the following tasks a. through f.
a. COMPLETION DATE: October 30,1990
TASK: GROUNDWATER REUSE AND RECLAMATION: Submit a technical report
acceptable to the Executive Officer containing the groundwater reuse and reclamation
plan for the treated groundwater. The report shall include documentation of efforts
to reuse the water, efforts to secure users for the water, and reasons why potential
users would not accept the water and discuss the technical feasibility and cost-
effectiveness of other water reuse options. The report shall also include an
evaluation of the recharge capacity of Calabazas Creek.
b. COMPLETION DATE May 31,1991
TASK: START UP OF EXPANDED REMEDIAL ACTION PLAN: Submit a technical
report acceptable to the Executive Officer containing the start up report for the final
remedial action plan. This report shall contain the final construction schedule for the
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time period from adoption of this order through submittal 6f the startup report, as-
built construction drawings of the system, and the first two months of monitoring
data.
c COMPLETION DATE; March SI, 1992
TASK: EVALUATE C-ZONE GROUNDWATER EXTRACTION: Submit a technical
report acceptable to the Executive Officer containing an evaluation of the
effectiveness of the C-zone extraction system including determination of fee C-zone
capture area based on field data and presentation of C-zone water chemistry data.
Propose a construction schedule for a C-zone extraction well and piping, if necessary.
d. CURTAILING SOIL VAPOR OR GROUNDWATER EXTRACTION "
1) COMPLETION DATE: 90 days prior to proposed curtailment of any soil vapor or
groundwater extraction well or treatment system
TASK: WELL PUMPING CURTAILMENT CRITERIA AND PROPOSAL Submit a
technical report acceptable to the Executive Officer containing a proposal for
curtailing pumping from the extraction well(s) and the criteria used to justify such
curtailment This report shall include data to show that groundwater or soil cleanup
standards for all VOCs have been achieved and pollutant levels have stabilized or are
stabilizing, and that the potential for pollutant levels rising above cleanup standards
is minimal
If the discharger claims that it is not feasible to achieve cleanup standards, the report
shall evaluate the alternate standards that can be achieved.
2) COMPLETION DATE; 60 days after the Board approves onsite curtailment
- TASK- IMPLEMENTATION OF CURTAILMENT: Submit a technical report
, acceptable to the Executive Officer documenting completion of the necessary tasks
identified in the technical report submitted for Task dl). Tasks d.1) and d.2) may be
incorporated in the quarterly reports specified in Provision C9 of this Order.
e. COMPLETION DATE: July 31,1995
TASK FIVE-YEAR STATUS REPORT AND EFFECTIVENESS EVALUATION. Submit
a technical report acceptable to the Executive Officer containing the results of any
additional investigation; an evaluation of the effectiveness of installed final cleanup
measures and cleanup costs; additional recommended measures to achieve final
cleanup objectives and standards, if necessary; a comparison of previous expected
costs with the costs incurred and projected costs necessary to achieve cleanup
objectives and standards; and the tasks and time schedule necessary to implement
any additional final cleanup measures. This report shall also describe the reuse of
extracted groundwater and evaluate and document the cleanup of polluted soil and
groundwater. If safe drinking water levels have not been achieved onshe and are not
expected to be achieved through continued groundwater extraction and/or soil
remediation, this report shall also contain an evaluation addressing whefter it is
technically feasible to achieve drinking-water quality, and if so, a proposal for
procedures to do so.
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f. COMPLETION DATE: 90 days, after request made by the Executive Officer
TASK: EVALUATION OF NEW HEALTH CRITERIA, Submit a technical report
acceptable to the Executive Officer which contains an evaluation of how the final
plan and cleanup standards would be affected, if the concentrations as listed in
Specification 6.4. change as a result of promulgation of drinking water standards,
maximum contaminant levels or action levels or other health based criteria.
g. COMPLETION DATE: 90 days after request made by the Executive Officer
TASK: EVALUATION OF NEW TECHNICAL INFORMATION. Submit a technical
report acceptable to the Executive Officer which contains an evaluation of new
technical and economic information which indicates that cleanup standards or
cleanup technologies in come areas may be considered for revision. Such technical
reports shall not be required unless the Executive Officer or the Board determines
that such new information indicates a reasonable possibility that the Order may need
to be changed under the criteria described in Finding 20.
7. The submittal of technical reports evaluating immediate, interim and final remedial measures
will include a projection of the cost effectiveness, benefits, and impact on public health,
welfare, and environment of each alternative measure. The remedial investigation and
feasibility study shall be consistent with the guidance provided by Subpart F of the National
Oil and Hazardous Substances Pollution Contingency Plan (40 CFR Part 300>, Section 25356.1
(c) of the California Health and Safety Code, CERGLA guidance documents with reference to
Remedial Investigation, Feasibility Studies, and Removal Actions-, and the State Water
Resources Control Board's Resolution No. 68-16, 'Statement of Policy with Respect to
Maintaining High Quality of Waters in California".
8. If the dischargers are delayed, interrupted or prevented from meeting one or more of the
completion dates specified in this Order, the dischargers shall promptly notify the Executive
Officer and the Board may consider revision to this Order.
4
9. Technical reports on compliance with the Prohibitions, Specifications, and Provisions of this
Order shall be submitted monthly to the Board commencing on October 15, 1990 and
covering the previous month. On a monthly basis thereafter, these reports shall consist of a
letter report that, (1) summarizes work completed since submittal of the previous report, and
work projected to be completed by the time of the next report, (2) identifies any obstacles
which may threaten compliance with the schedule of this Order and what actions are being
taken to overcome these obstacles, and (3) includes, in the event of non-compliance with
Provision G3. or any other Specification or Provision of this Order, written notification which
clarifies the reasons for non-compliance and which proposes specific measures and a schedule
to achieve compliance. This written notification shall identify work not completed that was
projected for completion, and shall identify the impact of non-compliance on achieving
compliance with the remaining requirements of this Order. The monthly reports shall be
submitted until the expanded remedial action plan startup report is submitted.
On a quarterly basis, quarterly reports shall include, but need not be limited to, updated
water table and piezometric surface maps for til affected water bearing zones, soil and
groundwater capture area maps, and appropriately scaled and detailed base maps showing
the location of all monitoring wells and extraction wells, and identifying adjacent facilities
and structures. Water level measurements are not required for wells where the configuration
of the pumping equipment does not permit the measurement to be taken. When appropriate,
due to new data, and upon request by the Executive Officer, new geologic data shall be
23
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incorporated in cross-sectional geological maps describing the hydrogeological setting of the >
site. Quarterly reports shall be due on the 30th day of the following month after the
reporting period
10. All hydrogeological plans, specifications, reports, and documents shall be signed by or
stamped with the seal of a registered geologist, engineering geologist or professional
engineer.
11. All samples shall be analyzed by State certified laboratories or laboratories accepted by the
Board using approved EPA methods, where available, for the type of analysis to be
performed. All laboratories shall maintain quality assurance/quality control records for Board
review.
12. The dischargers shall maintain in good working order, and operate, as efficiently as possible,
any facility or control system installed to achieve compliance with the requirements of this
Order.
13. Copies of all correspondence, reports, and documents pertaining to compliance with the
Prohibitions, Specifications, and Provisions of this Order, shall be provided to the following
agencies:
a. Santa Clara Valley Water District
b. City of Cupertino and City of Sunnyvale
c U. S. Environmental Protection Agency, Region DC (H-6-3)
The Executive Officer may additionally require copies of correspondence, reports and
documents pertaining to compliance with the Prohibitions, Specifications, and Provisions of
this Order to be provided to a local repository for public use.
14. Within 60 days of the Executive Officer's determination and actual notice to Vallco Park, Ltd.
that Siemens and/or Intersil have failed to comply with any portion of Provisions 1 through
10, of this Order, Vallco Park. Ltd., as landowner, shall comply with these Provisions.
15. Siemens, Intersil and Vallco Park, Ltd. shall permit the Board or its authorized representative,
in accordance with Section 13267(c) of the California Water Code:
a. Entry upon premises in which any pollution sources exist consistent with the site
Health and Safety Plan, or may potentially exist, or in which any required records
are kept, which are relevant to this Order.
b. Access to copy any records required to be kept under the terms and conditions of
this Order.
c Inspection of any monitoring equipment or methodology implemented in response to
this Order.
d Sampling of any groundwater or soil which is accessible, or may become accessible,
as part of any investigation or remedial action program undertaken by the discharger.
16. Vallco Park, Ltd shall file a report on any changes in site occupancy and ownership
associated with the facilities described in this Order.
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17. If any hazardous substance, as defined pursuant to Section 25140 of the California Health
and Safety Code, is discharged in or on any waters of the state, or discharged and deposited
where it is, or probably will be discharged in or on any waters of the state, the discharger
shall report such discharge to this Board, at (415) 464-1255 on weekdays during office hours
from 8 a.m. to 5 p.m., and to the Office of Emergency Services at (800) 852-7550 during non-
-business hours. A written report shall be filed with the Regional Board within five (5)
working days and shall contain information relative to: the nature of waste or pollutant,
quantity involved, duration of incident, cause of spill, Spill Prevention, Control, and
Countermeasure Plan (SPCQ in effect, if any, estimated size of affected area, nature of effect,
corrective measures that have been taken or planned, and a schedule of these activities, and
persons/agencies notified.
18. The Board will review this Order periodically and may revise the requirements when
necessary.
I, Steven R. Ritchie, Executive Officer, do hereby certify that the foregoing is a full, true and correct
copy of an Order adopted by the California Regional Water Quality Control Board, San Francisco
Bay Region, on August 15, 1990. /- /
Steven R. Ritchie
Executive Officer
Attachments:
Self-Monitoring Program
Site Map
25
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CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD
SAN FRANCISCO BAY REGION
SELF-MONITORING PROGRAM
FOR
Siemens Components, Inc
19000 Homestead Road
Cupertino, Santa Clara County
Intersil, Inc
10900 North Tantau Road
Cupertino, Santa Clara County
Vallco Park, Ltd
P. O. Drawer V
Cupertino, Santa Clara County
ORDER NO. 90 - 119
CONSISTS OF
PART A, December 1988
As Modified by SBTD, 1/23/89
With Appendices A-E
and
PART B, adopted August 15, 1990
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PARTB
Siemens Components, Inc Intersil, Inc
19000 Homestead Road 10900 North Tantau Ave.
Cupertino, Santa Clara County Cupertino, Santa Clara County
Vallco Park, Ltd.
P. O. Drawer V
Cupertino, Santa Clara County
1 DESCRIPTION OF SAMPLING STATIONS
• •
All existing and future perched, A-. B-, C- and deeper rone monitoring and extraction wells
as appropriate. See Table 2 (attached) for list of monitoring wells.
D, MISCELLANEOUS REPORTING. None.
Dl SCHEDULE OF SAMPLING AND ANALYSIS
The schedule of sampling and analysis shall be that given in Table 1 (attached).
IV. MODIFICATIONS TO PART A.
i
A. Delete Sections B, D, E, F.2, F3, G.1, G-4-b, G.4.e, and G.4.g.
6. In Section G.2, delete the first sentence of the third paragraph:
In addition, the waste discharger shall promptly accelerate his monitoring program to
analyze the discharge at least once every day (Section DJLh.).
C ' The first paragraph of Section G.4 shall be changed to read as follows:
4
Written reports shall be filed with the Regional Board regularly for each calendar
quarter (unless otherwise specified) and filed no later than the thirtieth day of the
following month. The reports shall be compromised of the following:
D. Section G.4.a.l.) shall be changed to read as follows:
1) Identification of all violations of the site cleanup order and self-monitoring
program found during the reporting period.
E Insert section C4.a3) to read as follows:
Time periods during which the soil vapor extraction system or groundwater treatment
system was not operating for greater than one week. Time periods during which the
individual groundwater extraction wells were not operating for greater than one
week.
F. The first paragraph of Section G.4.4. should be changed to read as follows:
Tabulations of the results from each required analysis specified in Part B by date,
type of sample and detection limit and station. The report format will be prepared
using the examples shown in APPENDIX B.
-------
C. Section C.4.d4) shall be changed to read as follows:
4) Lab results shall be signed by the laboratory director, copied, and submitted
as an appendix to the regular report
H. Insert Section G.4.d5) to read as follows:
The EPA Method 8240 analyses shall include tentative identification and
semi-quantified concentrations of non-priority pollutant substances of greatest
apparent concentration, to be followed by identification and confirmation of peaks of
greatest concentration.
L Insert a new section G.4.g. to read as follows:
For each individual vapor extraction well, the total soil vapor extraction system and
the groundwater extraction system: a quarterly tabulation showing the average air
and groundwater flow rate, the average influent air and groundwater concentration
and; on an annual basis, estimates of the average chemical mass removal rate from
soil and groundwater and the cumulative mass of chemicals removed from soil and
groundwater since startup. Include the above tabulations from startup, where
available, through the current reporting period Include concentration and mass data
for TCE, TCA, any other individual main constituents, and total volatile organic
compounds. When the existing vapor extraction system design does not permit the
measurement of air flow from an individual vapor extraction well, a suitable down
stream sampling point may be used to estimate air flow for that well.
J. The third sentence of Section G.5 shall be changed to read as follows.
In addition, the report shall contain a comprehensive discussion of the compliance
record and all corrective action taken or planned which may be needed to bring the
discharger into full compliance with the site cleanup Order and self-monitoring
requirements.
I Steven R. Ritchie, Executive Officer, hereby certify that the foregoing Self-Monitoring Program:
1. Has been developed in accordance with the procedure set forth in this Regional
Board's Resolution No. 73-16 in order to obtain data and document compliance with
site cleanup requirements established in Regional Board Order No. 90-119.
2. May be reviewed at any time subsequent to the effective date upon written notice
from the Executive Officer or request from the discharger, and revisions will be
ordered by the Executive Officer or Regional Board
3. Was adopted by the Board on August 15, 1990.
DATE Steven R. Ritchie
Executive Officer
Attachments: Table I
Table D
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TABLE 1
SCHEDULE FOR SAMPLING, MEASUREMENTS, AND ANALYSIS
! SAMPLING STATION »»
1
I
1
1 .
j TYPE OF SAMPLE
JEPA 8010/8020 or 8010
forcpurgeable priority
pollutants
|ln addition to:
Freon 113
j Priority Pollutant
Metals
JGC/MS (EPA 8240)
Open S"can
All existing and future perched, A-,
B-, C- and deeper zone monitoring
and extraction wells as listed in
Table 2.
---.-_-.__ i
G
Q, 2/Y,
1/Y
1/Y*
LEGEND FOR TABLE 1
G * grab sample
Q • quarterly
1/Y - once per year
2/Y » twice per year
* EPA 8010/8020 not required for quarters when EPA 8240 is
performed.
Sampling and analysis shall be consistent with an approved QAPP.
-------
TABLE 2
MONITOR ING WELLS TO BE SAMPLED AS REQUIRED IN TABLE 1
INTERSIL. INC.
Quarterly
W4A, W5A, W10A, W12A. E17A,
Semi-annual
W2A, W3A, W6B, W7A, W8B, W9A, WllB, W13A, W14A, W14B, WI8B
SIEMENS COMPONENTS. INC.
Semi-annual
LF-2A, MD(P), 2-1D, 2EP, 3-DD, 3-XA, 4BP. F-1A, G-1A. H-1A, H-2A, H-XA. LF-4A(P), LF^A. LF-9A,
T-2A*. W21A, W22A, 3-EB, H-3B, H-5B, LF-1B, LF-5B, LF^z), W19B, W20B, H-4C*
Quarterly
T-1A, LF-3B'(z)
INTERST17SIEMENS OFF-SITE STUDY AREA
Quarterly ,
S-1A, LF-8A, RK-1B, S-3B*. S-5B, KP-1B, LS-2B, PC-IB, LH-IC*. LR-3C'. RK-2C
4
Semi-annual
LS-1A, QH-1A, T-3A*, W15A*, W16A», PUB, S-2B, IQ-1B, IP-1B, KB-1B», KB-2B, KR-1B.LQ-2B, PH-1B,
PL-2C, S-4C, S-6C, BK-r. BK-2*. BK-3*. BK-4»
Annual
KL-1B
Note
Additional wells shall be included in Table 2 as installed
• • Only wells listed with a * shall be sampled by EPA Method 8020.
(P) • Wells 1-1D and LF-4A shall be analyzed annually for priority pollutant metals.
(z) - Wells LF-3B and LF-7B shall be analyzed annually for zinc
Due to drought conditions, some wells have insufficient water levels and slow recovery rates. Wells will
not be sampled if water levels are inadequate, but shall be re-incorporated into the monitoring program
if water levels recover sufficiently to permit accurate sampling.
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APPENDIX B
-------
SIF
•^ B Kmm
' l .
July 13, 1990 .... ^. ' " '••'.' , ^^^)
By Messenger
Mr. John Wolfenden
California Regional Water Quality Control Board
San Francisco Bay Region
1800 Harrison Street, Suite 700
Oakland/ California 94612
Re: Siemens Comments on Tentative Order
for the Intersil/Siemens Site
Dear John:
Enclosed are comments of Siemens Components, Inc. ("Siemens")
on the tentative site cleanup order for the Intersil/Siemens
site. For your convenience, we have handwritten suggested
changes on the attached copy of the tentative order.
Siemens has worked closely with Intersil, Inc. in preparation
of these comments. Therefore, most comments are joint
suggestions of both companies.
Please feel free to call me if you have any questions.
Sincerely,
R^John Wys*, Jr. ,
Business and Legal Affairs Manager
Enclosure
cc: Edward Firestone, Esq.
Robert L. Bines, Esq.
Siemens Components, Inc.
Oraoeteoronics Division 19000 Homestead Road Cupertino. California 95014 (408)257-7910
-------
John Wolfenden
July 13, 1990
Page 2
• Intersil and Siemens have jointly revised Table 2 to
Appendix B to more accurately reflect Intersil, Siemens
and AMI's respective responsibilities concerning the
sampling of designated monitoring wells. This has
resulted in the elimination from Table 2 of veils AMI-
1A, AMI-2A, VM-1B, BM-1B, HS-1B and KB -IB.
If you have any questions concerning Intersil's comments,
please do not hesitate to call me. Thank you.
Very truly yours,
Edward A. Firestone
Enclosure
cc: Steven Ritchie - RWQCB (v/o end.)
Steve Morse - RWQCB (v/o encl.)
Marie Lacey - EPA
Tom Iwamura - SCVWD (w/o encl.)
Burt Viskovich - City of Cupertino (v/o encl.)
J.P. Mailie - city of Sunnyvale (v/o encl.)
James Bruen - Landels, Ripley & Diamond
Nancy Bice - Geomatrix
John Wyss - Siemens Components, Inc.
Karen Nardi - McCutchen, Doyle, Brown & Enersen
Jeff Hennier - Levine-Fricke
Joel Nobrega - Vallco Park (v/o encl.)
-------
July 13, 1990
VIA MESSENGER ,
^ ':<;,•£-
John Wolfenden n."A«i-^
Regional Water Quality Control Board ^'•••-. / CC'.'."^>^. r.^
San Francisco Bay Region ~- --^icD
1800 Harrison Street, 7th Floor
Oakland, California 94612
Re: Intersil, Inc.'s Comments on Tentative Order No. 90-
, Site Cleanup Requirements for: Siemens, Intersil
and Vallco Park
Dear John:
Enclosed is an annotated version of the captioned Tentative
Order setting forth Intersil's comments. These comments have
been prepared in coordination with representatives of Siemens
Components, Inc. ("Siemens"). As a result, Intersil's comments
and suggested changes are nearly identical to those submitted by
Siemens (e.g.. differences may exist between the two companies'
submissions with respect to those portions of the Order that deal
solely with Intersil or solely with Siemens).
(
With respect to Intersil's comments, we wish to highlight
the following points:
• The bullet item concerning administrative civil
liability should be deleted (see Finding No. 3, page
2).
• The discussion regarding Intersil's acid
neutralization systems should be deleted (SSS. Finding
No. 4, page 2).
• Also with respect to the discussion of Site History,
the Order should reflect that Intersil began interim
remedial actions in 1986 when the inactive
neutralization system was removed fsee Finding No. 4,
page 2).
• Intersil requests that the RWQCB staff delete Finding
15.4 from the Order for the reasons set forth in the
May 16, 1990 letter froa Landels, Ripley & Diamond to
Steve Morse (attached as Appendix A to Intersil's June
1990 Feasibility Study Report), and also for the
reasons set forth in the July 13, 1990 letter from
John wyss to John Wolfenden.
Intersil, ire. • Err£ar:adero Center West • 275 Battery Street 23rd Floor • S*n Francisco. CA 94111 • 41S-986-14S6 • FAX 415-986-3958
-------
State of California
Memorandum
x_. /•_./.'" j """ *• ^-'l .... _
"' ...... '--4. . ._ _._
-Ul- • i ttl
Deportment of Health
10
from
Steven Ritchie, Executive Officer ~~
Regional Water Quality Control Board
1800 Harrison St., Suite 700
Oakland, CA 94612
office of Drinking Water
2151 Berkeley Way, Rm 458
Berkeley, CA 94704
8-571-2160
dc1e : July 11, 1990
Subject: Tentative Order
Site Clean-up
Requirements-
Intersil/ Siemens-
Proposed Superfund
Site-Santa Clara Cy
The subject document has been reviewed by the Department of
Health Services, Office of Drinking Water. We offer the
following comments:
The primary goal in remediation of hazardous waste
sites is the protection of public health and the
environment. The Office of Drinking Water has the
responsibility to ensure that the quality of California
drinking water is pure, wholesome and potable, that it
meets all applicable regulatory mandates, and
concentrations of foreign toxic substances present in
these drinking water supplies do not pose significant
or unacceptable health risks to human health. The
existing and potential beneficial uses of the
groundwater underlying and adjacent to the
Intersil/Siemens facilities include municipal and
domestic water supply. Within a one mile radius of the
site, there are currently 5 active municipal wells
operated by the Cities of Santa Clara and Sunnyvale.
Our review of the proposed cleanup operation is to
assure the potential hazards associated with the site
will not jeopardize the integrity of the affected
groundwater aquifers as domestic water supply sources.
The proposed cleanup operation includes 3 groundwater
aquifers; A- , B- , and the C-Zones. The C-Zone
aquifer at depths between 180 to 210 feet, is an
existing and potential domestic water supply source for
small water systems in the Santa Clara Valley. The C-
Zone aquifer is also an intermediate link between the
shallow aquifers in A- and B- Zones to the deeper
aquifers from which most existing municipal wells in
Santa Clara Valley currently draw for domestic supply
uses .
-------
Santo Clara Valley Water District
5750 AIMAOEN EXPRESSWAY
SAN JOSE, CALIFORNIA 95118
TELEPHONE (408) 265-5600
FACSIMILE (4081266-0271
AN Af FIRMATIV! ACTON EMPIOTH
o
JUL 1 ~ ;::£:>
-^
•' \
July 13, 1990
Mr. John Wolfenden
Regional Water Quality Control Board
1800 Harrison Street, Suite 700
Oakland, CA 94612
Dear Mr. Wolfenden:
Subject: Comments on Final Clean Up Proposal, Intersil/Siemens site, Cupertino, California
This letter presents our comments on the above subject site.
We are in general concurrence with the clean up proposal and water conservation practices proposed for
this site. However, we do have concerns regarding proposed clean up goals for existing or potential
drinking water aquifers. Consistent with our Board of Director's position on clean up goals for similar
sites, we urge you to consider setting clean up goals for carcinogenic contaminants using die Carcinogenic
Hazard Index Approach. As a dean up goal, this provides a more conservative approach when a
multiple carcinogenic chemicals are present
We fully understand that further remediation requirements would be evaluated based on feasibility and
risk assessment evaluation.
Please call Tom Iwamura or myself at (408) 927-0710 should you have any questions.
Sincerely,
Division
Ground
-------
3> GOULD
Gould AMI Semiconductors
2300 Buckskin Road, Pocatello. Idaho 83201
Telephone (208) 233-4690 l Semiconductors
July 12, 1990 JUL ' 3 13£3
A,i«M».rv
Steve I. Morse'
California Regional water Quality Control Board
1800 Harrison Street, Suite 700
Oakland, California 94612
Dear Mr. Morse:
Thank you for providing the opportunity for public comment on
the Board's Tentative Site Cleanup Order for Siemens Components,
Inc., Intersil, Inc., and Vallco Park, Ltd. The following few
comments are made on behalf of Gould AMI Semiconductors ("AMI").
Item 5 refers to the extent of soil pollution east of the
Siemens/Intersil plume. As you know, we are completing
investigation and undertaking interim remedial measures on our
former site. Our consultants advise us that complex
hydrogeological migration patterns exist in this area, and
conclusiveness with respect to the results of source investigation
may not be possible. Nonetheless, we intend to quickly remediate
identified elevated VOCs on our former site.
Item 7 refers to groundwater investigation, concluding that
off-site plumes appear to be defined. We have the same concerns
expressed above regarding the eastern and northeastern borders of
the Siemens/Intersil plume. This section refers to monitoring well
VM-lB at the far eastern extent of the plume network, which has
detected 10 parts per billion TCE. This well also has detected 4
parts per billion TCA. Our consultants advise us that the
combination and levels of these VOCs appear to be attributable to
the Siemens/Intersil plume. Thus, we believe the order's comment
that the elevated TCE detected at VM-lB "may be part of the AMI
groundwater plume" is unwarranted by the data.
Item 8 refers specifically to the former AMI facility. The
source of the elevated off-site levels discussed in this item has
not been established, and we believe conclusiveness with respect to
the results of source investigation may not be possible.
Nonetheless, we intend to quickly remediate identified elevated
VOCs on our former site in accordance with the interim remedial
action system referred to in this item of the order.
-------
Steve I. Morse
July 12, 1990
Page 2
Thank you once again for allowing us the opportunity to review
the Tentative Order and provide comment.
Very truly yours,
Dan Schroeder
Vice President - Fab Operations
and Development
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Steven Ritchie
Page 2
July 11, 1990
The proposed cleanup levels for the shallow groundwater
aquifers, designated as A- and B- Zones, to drinking
water standards, are appropriate for the potential
future use which will not include domestic supply
sources. We also concur with the proposed cleanup
levels for non-carcinogens at non-carcinogen hazard
index 1.0 for the 3 aquifers. However, the proposed
cleanup levels for carcinogens in conjunction with the
potential beneficial use of the C-Zone aquifer as a
.source of drinking water supply are of concern to the
Department.
The proposed remediation levels for carcinogens for the
C-Zone aquifer are:
EPA's "applicable or relevant and appropriate
requirements (ARARs), which, in this case,
are the same as the California Drinking Water
Standards, and
EPA's 10~4 to 10~6 Carcinogenic Risk Range
(CRR) for carcinogens prescribed in the "Risk
Assessment Guidance For Superfund, Human
Health Risk Assessment: US EPA Region IX
Recommendations", (EPA, 1989).
The Department does not support EPA's CRR of 10~4 to
10~6 as acceptable health risk levels for carcinogens
in drinking water; instead, we use the 10~6 as the
terminus risk level whenever this level of protection
can be accomplished with reasonable and cost effective
operation measures. We further do not concur with the
use of drinking water standards as the target cleanup
levels for contaminated groundwaters designated as
domestic water supply sources, particularly in
contaminated sites involving multiple chemicals.
Multiple chemicals-contamination sites present an
additional dimension of health risks because of the
additive and/or synergistic effects of the different
component toxicants in the chemical mixtures. These
effects are not well understood or reasonably defined.
The Department fully recognizes that there are
contaminated groundwaters in California which need to
be cleaned up and where the resulting product water
represents a significant resource which, in some
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Steven Ritchie
Page 3
July 11, 1990
situations, must be used for domestic consumption
purposes. For this reason, in the remediation of
contaminated sites, the Department strongly recommends
that cleanup should be at levels well below the
drinking water standards, to the extent possible,
within reasonable economic and technical limits. This
recommendation is reflected in the Department's "Policy
Guidance for Direct Domestic Use of Groundwater
Contaminated with Toxic Substances". Attached for your
reference is a copy of the Department's policy.
We also recommend the approach of carcinogen hazard
index (CHI) at unity (1.0) in setting cleanup goals for
aquifers used for domestic water supply purposes,
particularly in contamination sites involving chemical
mixtures. When chemical mixtures of carcinogenic
nature are present for which there is insufficient data
to evaluate the health effects associated with the
potential interaction among the component toxicants, it
is the practice of the Department to consider toxicants
to be additive in action. This additive action may be
expressed as the CHI and is calculated as follows:
CHI - C!/(AAL, AL or MCL)! * C2/(AAL, AL or MCL)2
+ .... + Cn/ (AAL, AL or MCL) n
In this equation, Cn is the concentration of the nth
toxicant, and (AAL, AL or MCL)n is the Applied Action
Level, Action Level, or Maximum Contaminant Level of
the nth toxicant.
The 1.0 CHI approach provides an additional measure of
protection for the surrounding environment and reduces
the possibility of chemical contamination of
neighboring areas, including the deeper aquifers which
can be affected by downward vertical movements of
toxicants from the contaminated zones. This approach is
in keeping with the goal of the Department's Drinking
Water Program, which is to assure that all Californians
are provided a reliable supply of safe drinking vater,
and the California Site Mitigation Decision Tree Manual
(DHS, 1986), which was the subject of public comment
and scientific peer review. The Decision Tree Manual
is also consistent with the Federal Superfund Public
Health Evaluation Manual (EPA, 1986).
In addition, the groundwater contamination at the
Intersil/Siemens site involves high concentrations of
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Steven Ritchie
Page 4
July 11, 1990
PCE, TCE and 1,1-DCE, among several other chemicals, in
the shallow aquifers. We are concerned about the
potential migration of these chemicals laterally and
vertically throughout the surrounding deeper aquifers.
Furthermore, the biotransformation of PCE, TCE in
groundwaters to other more toxic compounds such as DCE
and vinyl chloride, which poses additional health
hazards to the future users of the affected aquifers,
must also be considered. In the calculation of CRR for
Intersil/Siemens using the ARARs selected for this
site, these two issues of potential health hazards were
not considered.
Under Table 1: ARARs and TBC Criteria for
Intersil/Siemens in Fact Sheet 3 dated June 1990, the
concentrations for the following organic chemicals:
cis 1,2-DCE, trans 1,2-DCE, and Freon 113, are listed
as "proposed MCLs". Please be advised that the listed
concentrations for these chemicals have been adopted as
MCLs effective July 1, 1990. Attached for your
reference is a copy of all MCLs for organic chemicals
currently in effect in our Drinking Water Program.
We appreciate the opportunity to provide technical review and
evaluation relating to the water supply issues of the
Intersil/Siemens Cleanup Program. We understand that our
recommendation of approach on cleanup goals differs from that as
proposed in the Tentative Order. As discussed with Mr. John
Wolfenden and Mr. Steve Morse of your Board on several occasions
on the phone during the past two weeks, we do firmly believe that
the 1.0 CHI approach will provide an acceptable margin of safety
in the cleanup of contaminated groundwaters as well as a
reasonable assurance that future potential water users will not
be exposed to undue public health risks. If you have any
questions or would like to meet again to discuss further about
this matter, please do not hesitate to contact me.
Catherine S. Ling, P.E.
District Engineer
Monterey District
Attachments
cc: See next page,
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Steven Ritchie
Page 5
July 11, 1990
cc: Santa Clara County Health Department
Santa Clara Valley Water District
Santa Clara County Water Retailers
CWS-Los Altos
City of Cupertino
City of Gilroy
City of Milpitas
City of Morgan Hill
City of Mountain View
City of Palo Alto
City of San Jose
City of Santa Clara
City of Sunnyvale
Great Oaks Water Company
San Jose Water Company
Stanford University
-------
September 22, 1988
POLICY GUIDANCE FOR DIRECT DOMESTIC USE OF
GROUNDWATER CONTAMINATED WITH TOXIC SUBSTANCES
A. Purpose of Guidelines
Most plans for cleaning up groundwaters contaminated with
toxic substances involve extraction of the contaminated
groundwater and treatment to remove or reduce the contami-
nants. The treated groundwater then must "either be disposed
of or reused. In water short areas, this treated ground-
water is often considered to be a valuable resource which
should not be discarded. In a growing number of situations,
there is an interest in utilizing this water directly in a
domestic water supply distribution system. The purpose of
this guidance document is to set forth the position and the
basic tenets by which the Public Water Supply Branch (PWSB)
would consider such a proposal.
It is recognized that the circumstances surrounding each
situation may be different. Proposals, therefore, must be
considered on a" case-by-case basis. This document is
intended to set forth basic public health principles which
should be used by the PWSB staff in evaluating proposals and
in establishing appropriate permit conditions for any direct
use.
B. General Philosophy
The primary goal" of the PWSB drinking water program is to
assure that all Calif ornians are, to the extent possible,
provided a reliable supply of safe drinking water at all
times. In furtherance of this goal, the PWSB continues to
subscribe to the basic principle that only the best quality
sources of water reasonably available to a water utility
should be used for drinking. When feasible choices are
available, the sources presenting the least risk to public
health should be utilized. Furthermore, these sources
should be protected against contamination. Whenever
possible, lower quality source waters should be used for
nonconsumptive uses where there are lower health risks
(i.e., irrigation/ -recreation, groundwater replenishment, or
industrial uses) .
Water utilities should be encouraged to minimize the concen-
tration of toxic substances in drinking water (maximum
contaminant level [MCL] notwithstanding) whenever this can
be accomplished with reasonable and cost effective operation
measures.
Where reasonable alternatives .are available, high
drinking water should not be allowed to be degraded by
planned addition of contaminants. In other words, the MCLS
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-2-
should not be used to condone contamination up to those
levels where the addition of those contaminants can be
reasonably avoided.
Drinking water quality and public health considerations
shall be given a greater weight than costs or cost savings. .
The PWSB recognizes that there are contaminated ground-
waters in California which need to be cleaned up and where
the resulting product water represents a significant
resource which should not be wasted. In some situations,
it may be reasonable to consider the use of these treated
contaminated groundwaters for domestic use. Some communi-
ties nay not have any choice. In such cases, the public
health principles set forth in the following section should
be used to guide the evaluation of such situations.
C. Principles '
1. Alternative sources of drinking water reasonably
available to a water utility should be evaluated as
to comparative risk (assuming MCLs are, or can be,
met). These risks should be compared to cost benefit
and a judgement made as to the best source to be usea
within reasonable cost factors.
2. In evaluating the relative risk comparison of
alternative sources/ additive effects of multiple
contaminants are an important consideration.
Generally, consideration of allowing direct reuse of
contaminated groundwater should be limited to single
toxic contaminants or a limited number of similar
chemicals which can be reliably treated with the same
process.
3. Blending may be considered acceptable in lieu of
treatment for relatively low levels (i.e., less than
ten times the MCL) of contaminants which have lower
levels of associated risk as long as the blending
process is fully reliable and takes place prior to any
entry into the distribution system.
D. Principles Governing Use of Significantly Contaminated
Groundwaters
1. Groundwater containing multiple contaminants, ground-
waters which are likely to contain unknown contaminants
(such as groundwater subject to contamination from
" hazardous waste disposal site), or highly contaminate^
groundwater should not be considered for direct human
consumption where alternatives are available.
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-3-
Where alternative sources present greater overall risks
or are not available, and the groundwater contains
high concentrations of contaminants or multiple
contaminants, the treatment process used to treat the
contaminated groundwater prior to direct usage; in a
domestic water distribution system must be commensurate.
with the degree of risk associated with the contami-
nants. As a minimum, treatment for relatively high
risk sources shall include use of the best available
treatment technology defined for that contaminant by
the Environmental Protection Agency. Furthermore, the
treatment processes must have full reliability features
consistent with the type and degree of contamination
in the groundwater.
The treatment process used must be capable of reliably
producing water meeting MCLs in the discharge line
from the final treatment process at all times. Any
water from other sources that is available for blending
prior- to entry into the distribution system should be
used to provide an additional safety factor.
Facilities for treating water containing specific
contaminants, for which the MCL is higher than the
maximum contaminant level goal (MCLG) and where the
water is intentionally added to the distribution
system, should be designed and operated to meet the
MCLG where this can be accomplished in a cost effective
manner.
Projects proposing to use highly contaminated ground-
water as a source of domestic water supply should be
subjected to a public hearing or meeting prior to the
issuance of a domestic water supply permit, regardless
of compliance with MCLs.
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64444.-5. Maximum Contaminant Levels.
The maximum contaminant levels for the primary drinking
water-constituents shown in Table 5 shall not be exceeded in
the water supplied to the public.
Table 5
Maximum Contaminant Levels
Organic Chemicals
Constituent
Maximum Contami-
nant Level, mg/1
(a) Chlorinated Hydrocarbons
Endrin 0.0002
Lindane 0.004
Methbxychlor .; 0.1
Toxaphene 0. 005
(b) Chlorophenoxys
2, 4-D 0.1
2, 4, 5-TP Silvex 0.01
(c) Synthetics
Atrazine 0.003 •
Bcntazon 0.018
Benzene 0.001
Carbon Tetrachlpride 0.0005
Carbofuran 0.018
Chlordane.. 0.0001
1,2-Dibromo-3-chloropropane 0.0002
1, 4-Dichlorobenzene 0.005
1,1-Dichloroethane 0.005
1,,2-Dichloroethane 0.0005
cis-l,2-Dichloroethylene 0.006
trans-l,2-Dichloroethylene 0.0.1
1,1-Dichloroethylene 0.006
1,2-Dichloropropane 0.005
1, 3-Dichloropropene 0.0005
Di(2-ethylhexyl)phthalate 0.004
Ethylbenzene 0.680
Ethylene Dibromide 0. 00002
Glyphosate 0.7
Heptachlor o.ooooi
Heptachlor Epoxide. 0.00001
Molinate 0.02
Monochlorobenzene 0.030
Simazine 0.01
1,1,2,2-Tetrachloroethane 0.001
Tetrachloroethylene 0.005
Thiobencarb 0.07
1,1,1-Trichloroethane 0.200
1,1,2-Trichloroethane ' ... 0.032
Trichloroethylene :.. 0.005
. Trichlorof luoromethane..*. '.. 0.15
l.l^-Trichloro-l^^-Trifluoroethane.... 1.2
Vinyl Chloride 0.0005
. Xyler.es..... 1.750*
-i-iCL is for either single isomer or the sum of the isomers,
-------
Appendix B.2
(Comments/Correspondence Received after 30-day comment period - June 13 to July 13, 1990)
-------
Jul 31,90 10:03
P.02
THE
*.y ----^ Tia II
isSrsssr^ftS liUilJ
AtfCARA
30 July 1990
W«Tf • OCPT.
CITY
i aoo
5AKTA CWA«A. CA 65OSO
(«06l 964-11 «S
Mr. StevenR. Ritchie
Executive Officer
California Regional Water Quality Control Board
1600 Harrison Street, Suite 700
Oakland. CA 94612
SUBJECT: CLEANUP ALTERNATIVES FOR INTERSIL/SIEMENS SUPERFUNO SITE
Dear Mr, Ritchie,
This is in response to the proposed remediation plan recommended by the Regional Water Quality Control Board staff
_nd outlined in Fact Sheet 3 issued in June. I am sorry to have been delayed in my response. I received Fact Sheet
3 on 21 June, but was unable to complete my review of your plan before the public comment deadline; I needed some
additional information which was only recently received.
In my opinion the Regional Board staff has done an overall outstanding job In its handling of this case. Your staff is
to be c ommended for the manner in which they have assembled the necessary data, conducted public meetings and
developed the remediation goals and alternatives. There are, however, several substantive Issues which concern
the City of Santa Clara, and I would like to bring these to your attention at this time for the record,
The City of Santa Clara provides drinking water to a population of over 90,000 persons. Approximately 65% of the
water served by the City is obtained from the deep groundwater aquifers lying beneath it. The remainder is treated
surface water purchased from other agencies. It is very likely that groundwater will always form the backbone of the
City's water supply, and for that reason the City is extremely concerned about the long-term quality of that resource.
The deep aquifers from which Santa Clara pumps Us water are within the confined (pressure) zone, i.e., overlaid by
a regional aquhard. This aqultard, consisting of clay layers up to hundreds of feet thick, has long been thought to
protect the confined (deep) aquifers from contamination percolating down from the surface or from the shallow
aquifers which are exposed to such percolation. Beginning in 1984, routine groundwater testing In compliance with
A3-1603 has detected very small concentrations of two volatile organic contaminants (VOCs) in City of Santa Clara
Wetl Number 24, which is approximately 1,100 meters down-gradient from the Intersil/Siemens site. Your office has
been kept aware of these findings from the beginning. While there is no proof these contaminants emanated from the
Intersil/Siemens s'rte, the same species were detected there and In the Marchese well: 1,1,1 -trichloroethane (TCA)
and 1,1,2-trichloro-1,2,2-trifluoroethane (Freon 113).
1. K Is unequivocal that VOCs exist in significant concentrations in all throt shallow aquifers, both on- and off-site.
One of City's concerns is that your recommended remediation alternatives do not adequately address removal of
contaminants from ad three shallow aquifers with equal efficiency. H would seem prudent that extraction of polluted
i ground-water from the C-zone be a priority, rather than the 'contingency* stated In your remediation plan. Whereas
groundwater modeling by Regional Board staff may indicate there would be an upflow between the C-zone and the
B-zone from whence the polluted water would be extracted, characterization of the contaminants Indicates they are
generally insoluble in water and of higher specific gravity. Effective removal from the C-zone by pumping the B-zone
may be problematical. Failure to adequately contain and remove the contaminants from the C-zone aquifers may
result in their eventual transport into the deep aquifers.
f
: try to inks
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Jul 31,90 10:04
P.03
projected in your plan may meet current water quality standards (ARARs), the City of Santa Clara may leter be faced
with having to treat that groundwater in order to meet hearth-baaed standards mandated by the EPA and the tttte for
the very tame set ofcontamlMntsfor even having to take one or more of our wells out of service—aa was suggested
at one time by a member of your staff). I point to the advent of Recommended Public Health Levels (RPHLs) for
drinking water which will be promulgated in early 1991. It la my understanding that RPHLs tor carcinogens will be
based on a 10 uppcrbound cancer risk. In view of the proposed RPHLs, remediation to a 10' risk, level seems
dichotomcus. The City of Santa Clara would hope to see a remediation plan which will achieve the 10 ri&K level for
carcinogens, with non-carcinogens not exceeding a Hazard index of unity.
Thank you for taking the time to hear of our concerns. I know that you and your staff will do your very best on behalf
of the citizens of Santa Clara and the region at the upcoming Beard Hearing on the remediation plan.
Very truly youre,
Richard H. Hathorrv'
Oit ector of Water & Sewer Utilities
RHHrlbm C\WP51 \FILES\INT5IEM.RWQ
cc: John Wolfenden, RWQC8
Jim Thompson, RWQCB
Roger James, SCVWD
City Manager
RWQCB file
CERCLAWe
-------
"NT BY: ; 8. ,.90 . 18;02 .
Staff ef California
•
Memorandum
TO « Steven Ritchie, Executive Officer
Regional Water (Quality Control Board
1800 Harrison St., Suit* 700
Oakland, CA 94612
Office of Drinking Water
2131 Berkeley Way, to 45$
Berkeley, CA 94704
8-571-2160
SAN RAD LAB-» SAN FRAN BAYJf 2
Department ef Health Servkei
»
Dot* • JUly 11, 1990
Tentative Ordere
Site Clean-up
Requirements-
Intersil/ Siemens
i Solvent Service*-
Proposed Superfund
Sites-SantaClara Cy
On July 24, 1990 Mr. Steve Morse of your Board requested
clarifications and additional comments from the Department of
Health Services (OOHS) - Office of Drinking Water (ODW) on the
Cleanup Requirements of Superfund sites in Santa Clara County.
These comments are supplemental to those previously submitted to
the Board in a nemo dated July 11, 1990. We have recently
completed review for 2 cleanup sites: Intersil/Siemens (X/S)
and Solvent Services Inc. (S8Z)• Inasmuch at our general
guidance on cleanup goal* for cleanup ef contaminated
groundwaters involving domestic water issues is the same, we have
combined the two sites in our response memos. Tor case-specific
comments on the discussions of cleanup alternatives, Carcinogen
Hazard index (CHI), and risk calculations for the I/s and SSI
sites, please refer to Appendices A and B, respectively,
DOHS-OOW - CLEANUP GOALS
As stated in our July 11, 1990 memo, for the purpose of setting
cleanup goal* for contaminated groundwaters designated as
domestic water supply source, the following are the guiding
principles used by the Office of Drinking Watert
1* The total cancer risk level does not exceed 10**, or
2. Carcinogenic Hatard Index does not exceed 1.0, and
3. Ho contaminants exceed MCL or AL, where applicable.
The above criteria should be followed whenever it is
technologically and economically feasible in the remediation of
contaminated groundwater aquifers for the protection of their
beneficial uses involving domestic consumption.
-------
SENT BY: ; |- 1-80 ; 16^02 ? SAN RAO LAB* SAN FRAN BAY18 3
Steven Ritchie
Pago ?
July 91,
REGIONAL BOARD (RB) • PROPOSED CLEANUP LEVELS
We acknowledge the method and procedural used by the Board etaff
for deriving cleanup levele for Super fund eitee. The procedural
are detailed in the "Guidance Document for the Development of
Health-Based Remedial Clean-up Levels for the South Bay Multi-
site cooperative Superfund Program1* (RWQCB, June 20, 1990). The
basis for this guidance document stems from the EPA'e Kational
Oil and Hazardous Substances Pollution Contingency Plan, 1990,
and the Risk Assessment Guidance For Superfund, Human Health RisX
Assessments EPA Region XX Recommendations, 1989 (Interim Final) .
We also acknowledge that the method used by the Board etaff vas
developed primarily to handle cleanup of Superfund sites. The
method does not adequately address specific concerns on the
protection of affected groundwatera ae domestic water supply
sources.
We must aleo add that in the development of the Board's "Guidance
Document", the Department wae not informed about it or made part
of its peer review prior to f inalization.
Consequently, the cleanup levels prescribed for both the 1/8 and
SSI sites proposed in the Tentative Orders involve a much higher
total cancer risk than the Department •• recommended 10*° level.
in addition, using the Carcinogen Hazard Index approach, these
contaminated sites after remediation ordered by the Board, will
still have hatard indices many times higher than 1.0.
We are opposed to these cleanup level* as they are excessively
high and do not adequately protect the groundwater'e beneficial
uses as domestic supply sources.
CLEANUP FEASIBILITY
On the issue of cleanup feasibility. Board staff indicated during
the July 24 meeting thati pursuant to the Board's Resolution No.
68-16, the Non-degradation Policy, the RI/FS conducted by both
1/8 and S8Z included the evaluation of cleanup to "non-
detectable" or "background" levele. The Board then made the
determination that this alternative would be economically and
technically in feasible. He agree that it would be impractical to
clean up to non-detectable level*. We also request the Board to
re-examine the feasibility of a cleanup alternative and to
reconsider the setting of cleanup requirements to e more health
protective level from the standpoint of protection of domestic
water quality.
-------
-NT BY'
e- i-
SAN RAO LAB-*
SAN FRAN BAY!8 4
Steven Ritchie
Page 3
July 31, 1990
CALIFORNIA SAFE DRINKIKO WATER ACT-RECOMMENDED PUBLIC HEALTH
LEVELS (RPHLS)
In addition, we draw your attention to section 4023 of the
California Safe Drinking Water Act on Recommended Public Health
Level* (RFHLs). A copy of the Act is enclosed for your
reference. The Department ie currently in the process of
promulgating the RPKLe mandated by our Drinking Water Program.
RPHLs are health-based goals set to further reduce contaminant*
in domestic water supplies to below the MCL. For carcinogenic
compounds, the RPHLs will be set at the 10"° cancer risk level.
These RPHLs will be applied to all domestic water sources.
Water suppliers serving 10,000 service connections or more will
be required to submit, a Water Quality Improvement Plan (WQIP) to
the Department demonstrating the feasibility of providing
additional treatment as well as monitoring control in order to
rceet the RPHLs in both their existing as well as new water
sources.
In essence, the WQIP can be viewed as a parallel document as the
Remedial Investigation /Feasibility Study (Rl/rs) retired of the
responsible party(ies) by the Board* The water suppliers will be
charged with the responsibilities in meeting more conservative
and health protective water quality standards than these
required of responsible parties in the cleanup of the
groundwater. We hereby advise the Board of this serious
potential shortcoming in imposing less than acceptable or health
protective remediation levels in the affected groundwater
aquifers used for domestic supply source.
We would also like to point out that in accordance with the EPA'a
National contingency Plan, the RPHLe, when promulgated, will
become the ARARs. The RPHLs ars currently in development. We
will keep the Board informed of all adopted RPHLs in the future.
Thank you for your consideration on this important issue relating
water supply quality. We are hopeful that we can work jointly to
resolve this problem. We will be available to further discuss
this issue at your request or you may have questions we can
answsr by phone. Please do not hesitate to contact me at (415)
540-2160.
Atttchaants
cct See next page
Catherine 8. Ling,
District Engineer
Monterey District
-------
SENT BY:
; e- 1-80 ; lew ; SAN RAD LAB- SAN FRAN BAYII 5
Steven Ritchie
Pft^e 4'
July 3i« 1990
cc: Santa Clara County Health Department
santa Clara Valley Water District
Santa Clara County Hater Retailers
CKS-LOS AltOC
City of Cupertino
City of Cilroy
City of Nilpitas
city of Morgan Rill
City of Mountain Viaw
City of Palo Alto
City of San Jos*
City of Santa Clara
City of Sunnyvale
Great OaXi Water Company
San Joae Water Company
Stanford Univereity
-------
BY:
e- 1-90 ;
SAN RAO LAB"
SAN FRAN BAY;« e
Steven Ritchie
Page 5
July 51, 1990
APPENDIX At INTERSIL/SIEMENS SUPERTUND SITf
A. Cleanup levels
The proposed cleanup levels prescribed for the I/a site contained
in the Tentative Order are the ARARs(- MCL) for all the chemicals
in all of the A* , B- and C- zone aquifers*
AS presented by Mr. Wolfenden using the risk calculations, the
cleanup of PCS and TCB to MCL in the A- .and B» zone aquifers
would result in a total risk of 3.8 x 10~*. This is 3.8 times
higher than the 10~* level recommended by the Department of
Health Services. Using the DOHS CHI approach for 3 carcinogens
at MCL, it would have an index of 2.0, twice that recommended by
DORS. However, ae stated in our July 11 nemo, the A- and B-
Zcnes are considered non-domestic supply zone. Our cleanup goals
would not be applicable in this case.
In the C* Zone aquifer, Mr. Wolfenden pointed out that the VOCs
currently detected include 19 ppb of TCE and 1 ppb Of 1,1-DCE.
Since DOB is considered as a non-carcinogen, only TCS is of
concern in this particular aquifer* The proposed cleanup to
drinking water standard for TCS would be acceptable from a
domestic supply standpoint because only a aingia carcinogenic
chemical is involved in this case. Also, as discussed during the
July 24, 1990 meeting, the proposed cleanup to MCL for TCE at a
much higher concentration than that of OCE would at the same time
bring the OCX to very low or non-detectable level, assuming
comparable removability of both TCE and DCE in the aquifer. We
agree with this. In this case, we sugguest that it would be more
appropriate for the Board to communicate the "actual" total
cancer risk expected from the remediation rather than the risk
calculated with the assumption that all of the chemicals are at
MCL or ARARs levels.
B. Cleanup alternatives
The feasibility of cleanup to drinking water standards for
chemicals in all of the three shallow aquifers A-, B- and C*
Zones is based on the proposed remediation plan of extracting
contaminated water only from the A- and B- Cone aquifers. No
groundwater extraction or remediation is currently proposed for
the C- Zone aquifer. The groundwater model used by the Board
predicts an upward flow of contaminated water from C- Zone
aquifer to the upper A- and B- Zone aquifers. The model for
this cleanup alternative also projects to a 45-year period of
remediation. This appears to be an extremely long and energy
intensive; task.
-------
SENT BY:
; e- 1-90 ; ie:os
SAN RAO LAB-
SAN FRAN BAYJt 7
Steven Ritchie
Page 6
July 31, 1990
We question the validity of the cleanup plan which does not
include a direct remediation plan for C- Zone aquifer, tinea this
is the moat vulnerable con* with reepect to domestic water
supply. As discussed previously, the C- Zone aquifer it an
existing domestic water supply source for snail system wells,
and is also the immediate link to the deeper aquifers, which is
the primary source for most of large water systems.
The Board should examine the feasibility of direct extraction
from the c aquifer. This could be a more cost-effective and
time* efficient alternative for the overall cleanup program at
I/S.
-------
JYT
J 8- 1-80 ; 16:05
SAN RAO LAB*
SAN FRAN BAY;s e
Steven Ritchie
Page 7
July 31, 1990
APPENDIX BS SOLVENT SERVICES INC. SUPERFUND SITE
A. Background
The 8SX eite involve* multiple chemicals which have
contaminated the A, B/C, and D/E aquifers, both on- and off-
site* The greatest extent of contaaination ie in the upper
A and B/C aquifers. The D/E aquifer ie an existing domestic
water supply source. Within one Bile radius froa the site,
there are 2 existing domestic water supply wells drawing
from the D/I aquifer.
The carcinogenic chemicala of concern are (8)s Arsenic,
Benzene, Vinyl Chloride, 1,1-DCA, Kethylene Chloride, PCE,
TCS, Chlorofora.
The non-carcinogenic chemicals of concern are (14)s
Acetone, 2-Butanona, 1,2-DCB, Cis-l,2-DC8, 1,1-DCS, Trans-
1,2-DCE, Ethylbenrene, Freon-113, 4-Meth-2-Fent., Nickel,
Phenol, 1,1,1-TCA, Toluene, Xylene.
B. Cleanup levels
KCHI • 0.96 for noncarcinogens.
Total Cancer HisX including Arssnio • 4.98 x 10"4
As shown, the cleanup levele proposed in the Tentative Order
by the Board for the S8X site involve e much higher (498
tines) cancer risk than 10~5. in addition, applying the
DOKS CHI approach results in a Kaiard Index of 7.1.
As stated in our July 11 memo, the interactive effects of
the different component toxicants in the mixtures are not
well defined and understood. He are greatly concerned about
the additional health risks and hazards associated with
mixtures of chemicals. We again request the Board to re-
examine the feasibility of additional remediation measures
and to reconsider lowering the cleanup levels to s more
health protective level.
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SENT BY:
; e- 1-80 ; ie:oe ;
SAN RAO LAB-
SAN FRAN BAY;« 8
Steven RitehU
Page ft
July 31, 1990
C. Cleanup alternative
The extent of the contamination and the characterization of
the plum* off-site were not clear from the Tentative
Order. However, it ie clear that there will be no direct
remediation measure taken. Instead, the remediation of
contamination off-site ie proposed as a "contingency* plan.
It depends solely on the on-cite containment process. This
process involves the operation of 3 extraction trenches to
"pull bade* and recover, contaminants from the groundvatar
off-site. The Order, on the other hand, specifically
states that the effectiveness of such proposed contingency
plan has not been demonstrated by current data* It there
another contingency plan in wait in ease the proposed one
fails?
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1
August 2, 1990
AUG tt2
QUALITY CW'fllQL BOARD
John Wolfcndei
Regional Water Quality Control Board
San Francisco Bay Region
1800 Harrison Street, 7th Floor
Oakland, California 94612
Re: Intersil, Inc.'s Response to Comments by DOHS, Office
of Drinking Water, Concerning Intersil/Siemens Site
Tentative Order
Dear John:
This letter presents Intersil's position regarding comments
submitted to the Regional Board by the Department of Health
Services, Office of Drinking Water ("ODW") dated July 11, 1990,
concerning ODW's review of the Tentative Order for the
Intersil/Siemens proposed Superfund site. At the outset, we wish
to express our complete agreement with Regional Board staff
statements that ODW's suggested use of a carcinogenic hazard
index ("CHI1*) of one or a 10*6 carcinogenic risk level as cleanup
standards are inappropriate and should be rejected.1 Intersil's
comments encompass many of the points raised by Regional Board
staff in the Responsiveness Summary (Appendix C to the Tentative
1 Intersil also notes that no branch or office of the
Department of Health Services commented on Intersil or Siemens' /
On-Site and Off-Site RI/FS Reports, or on the Baseline Public
Health Evaluation prepared by Clement Associates under contract
to the RWQCB. In fact, in a letter dated January 22, 1990 from
David Wang, Chief, Site Mitigation Unit, Toxics Division,
Region 2 to John Wyss of Siemens Components, inc., the
Department specifically asked to be removed from the mailing list
for this Site.
tnwnril tor
»75 B*nir,f rtTi.ii, mi
Pin Franste*, SAJH111 - ,m..?w i UC •
-------
John .Wolfenden
August 2, 1990
Page 2
O^der), and are intended to supplement that summary. Our
comments are as follows:
A. x The Regional Board Should Reiect ODW's Suggested
"Terminus Risk Level" of 10**, ODW's "Policy Guidance
for Direct Domestic Use of Groundwater Contaminated
with Toxic Substances", and ODW's Suggested Use of a
Carcinogenic Hazard Index of One, Because They are not
ARARs. -
In its comments to the Regional Board, ODW stated that the
proposed cleanup levels for the A- and B- zones are appropriate
given the potential future use of these aquifers. With respect
to proposed cleanup levels in the C-zone however, ODW indicated
some concern.2
The Tentative Order has established C-zone cleanup levels
Consistent with the Regional Board's determination that
"(ajchieving drinking water quality is an ARAR for this site."
Tentative Order, Finding No. 18, p. 12. That is, groundwater
cleanup standards for the site are EPA Maximum Contaminant Levels
("MCLs"), California Department of Health Services ("DOHS") MCLs,
and DOHS Recommended Drinking Water Action levels ("RDWALs").
Id. These cleanup standards are derived from federal and state
standards, requirements, criteria and limitations, and therefore
constitute ARARs within the meaning of Section 121(d)(2) of
CERCLA, as amended by SARA, 42 U.S.C. S 9621(d)(2). In contrast,
ODW's recommended use of a CHI of one and 10"* carcinogenic risk
level are not ARARs and should not be used to establish cleanup
levels.
2 As a factual mater, ODW's contention that the C-zone
should have lower cleanup levels is incorrect. First, data
collected to date by Intersil and Siemens' consultants indicates
that the A-, B-, and C-zones in the vicinity of the
Intersil/Siemens Site are part of a shallow water bearing zone
that is separated from the Deeper Aquifers by a 75-foot-thick
regional aquitard. Seef e.g.. Tentative Order, Finding No. 6,
p. 3. There is evidence suggesting that the B- and C-zones are
hydraulically connected in the Site region; but there is no
evidence of any hydraulic connection between these two zones and
the Deeper Aquifers. Second, no evidence has been found to
support ODW's statement that the C-zone is an existing domestic
water supply source in the vicinity of the Site. Instead,
available information indicates that the municipal supply wells
in the region draw water from the Deeper Aquifers.
-------
John Wolfenden
August 2, 1990
Page 3
% In order for ODW's recommended use of a CHI of one, a
carcinogenic risk level of 10"*, or the "Policy Guidance for
Direct Domestic Use of Groundwater Contaminated with Toxic
Substances" to rise to the level of an ARAR, they must, among
other things, be "promulgated.1* 42 U.S.C. S 9621 (d) (2) (A) (ii) .
To be "promulgated," ODW's suggested approach must be "generally
applicable" and "legally enforceable." 40 C.F.R.
S 300.400(g)(4). The approaches suggested by ODW to establish
cleanup levels meet neither of these criteria.
First, standards that are inconsistently applied are not
"generally applicable" standards. See, e.g.. 42 U.S.C.
S 9621(d)(4)(E).3 RWQCB staff communications with DOHS
representatives, and a review of actions taken at certain DOHS-
lead Superfund sites, indicate that ODW's recommended procedures
are not consistently applied within DOHS.
RWQCB staff discussions with Jeff Wong of DOHS' Toxics
Biar.ch (Sacramento), reveal that the Toxics Branch was "unaware
of any [DOHS] requirement that the CHI using MCLs in the
denominator was required to be less than one for cleanup levels."
Responsiveness Summary, p. 3. In addition, DOHS recently
approved cleanup levels that exceeded a 10* * risk level at a
State Superfund site in Palo Alto. See DOHS Fact Sheet No. 4 for
Stage 1 FS, Aydin Energy State Superfund Site, Palo Alto,
California (June 1990). These examples demonstrate that the
approach espoused by ODW in its comments has not been
consistently (if at all) applied and therefore is not "generally
applicable" so as to qualify as an ARAR under Section 121(d)(2)
of CERCLA, or under 40 C.F.R. S 300.400(d)(4).
Second, ODW's proposed methods and policies must be
"legally enforceable" to be an ARAR. In order to be legally
enforceable, ODW's recommended methods and policies must
constitute a "substantive rule" (i.e.f one enacted by an
administrative agency pursuant to statutory delegation). In this
case, ODW's use of a CHI of one and a 10'* carcinogenic risk
level is at best a general statement of policy, the application
3 In addition, for a cleanup standard to be generally
applicable, it must be appropriate for use as a cleanup standard
for all sites. 55 Fed. Reg. 8746. The "Policy Guidance for
Direct Domestic Use of Groundwater. . ." involves guidelines
whereby the Public Water Supply Branch of DOHS would consider the
later use of treated groundwater in a domestic water supply
distribution system. Thus, the policy does not appear to apply
in the context of establishing cleanup levels for aquifers such
as the A-, B- and C-zones beneath the Intersil/Siemens Site.
-------
John Wolfenden
August 2, 1990
Page 4
6^ which is apparently inconsistent even within the different
offices and branches of DOHS. Because ODW's policies are not
legally enforceable, they are not ARARs.4
B. x The CHI Equation Used by ODW is Technically Flawed
with Regard to Maintaining a Specific Incremental
Cancer Risk Goal, and Therefore Should not be Used to
Develop Cleanup Standards at the Site.
In its comments, OOH sets forth its equation to calculate
the CHI. Intersil's analysis of that equation reveals that the
equation is inconsistent with ODW's stated goal of an incremental
cancer risk of 10* *. The CHI equation used by ODW appears to be
derived from calculations in the California Site Mitigation
Decision Tree Manual (the "Manual"). The Manual bases its risk
calculations on DOHS Applied Action Levels (AALs). For
carcinogens, AALs are based on a maximum exposure level ("MEL")
that produces one adverse effect in a population of one million
exposed receptors, or an incremental carcinogenic risk of 10*6.
The MELs are derived from toxicity studies such as
epidemiological research or long-term animal bioassays. AALs are
based entirely on health effects and do not consider the
limitations of technology, whereas Action Levels (ALs) and
Maximum Contaminant Levels (MCLs), are health-based values
modified as necessary to consider cost and technical limitations.
AALs are specific to the chemical, the receptor, and the medium
of exposure. The procedures in the Manual call for summing the
ratios of the chemical concentration to the AAL over the
chemicals and the exposure route. If this sum is greater than
one for carcinogens, the total incremental carcinogenic risk to a
receptor is greater than 10* *.
The CHI equation used by ODW is similar in form to the
equation used in the Manual with the following significant
difference: ODW's equation allows for the use of AALs, ALs, or
4 Lead and support agencies may consider other
advisories, criteria, or guidance in establishing cleanup
standards. 55 Fed. Reg. 8746. "To be considered" factors
("TBCs") may be considered in developing cleanup levels and the
like, but unlike ARARs, they are not binding cleanup standards
that must be achieved. At this Site, the RWQCB actually
considered the various points raised in ODW's comments in the
context of the remedial alternatives that evaluated cleanup to
background. See Tentative Order, Finding Nos. 13.1.6, 13.2.6,
and 13.3.6, pp. 7-9. The RWQCB rejected these alternatives
because of considerations based on time to cleanup, cost and
groundwater conservation. ISL., Finding No. 16, p. 12.
-------
iVT BY:
; e- 1-fiO ; 16=05 ;
SAN RAO LAB"
SAN FRAN BAY:8 8
Steven Ritchie
Pago 7
July 31, 1990
APPENDIX Bt SOLVENT SERVICES INC. SUPERTUND 8ZT1
A* Background
The ssz site involves multiple cheaioals which have
contaminated the A, B/C, and D/E aquifers, both on- and off-
site. The greatest extent of contaaination ie in the upper
A and B/c aquifers. The D/E aquifer ie an exieting domestic
water supply source. Within one Bile radiue from the site,
there are 2 existing domestic water supply veil*, drawing
from the D/l aquifer*
The carcinogenic chemicals of concern are (8)t Arsenic,
Benzene, Vinyl Chloride, 1,1-OCA, Kethylene Chloride, PCS,
TCS, Chiorofora.
The non-carcinogenic chemicals of concern are (14)t
Acetone, 2-Butanone, 1,2-DCB, Cis-l,2-DC£, 1,1-DCE, Trans-
1,2-DCE, Ethylbencene, Freon«113, 4-Meth-2-P«nt,, Nickel,
Phenol, 1,1,1-TCA, Toluene, xylene.
B. Cleanup level*
KCRZ « 0.96 for noncarcinogan*.
Total Cancer Risk including Arsenic • 4.98 x 10*4
As shown, the cleanup levels proposed in the Tentative Order
by the Board for the SSZ site involve e auch higher (498
tiaec) cancer risk than 10~tt. In addition, applying the
DOHS CHI approach results in a Hazard index of 7.1.
As stated in our July 11 aeao, the interactive effects of
the different component toxicants in the mixtures are not
veil defined and understood. He are greatly concerned about
the additional health risks and hazards associated with
cixtures of chemicals. We again request the Board to re-
exaaine the feasibility of additional reaediation aeasures
end to reconsider lowering the cleanup levels to a aore
health protective level.
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SENT BY:
J 8- 1-80 ; 18206 i
SAN RAO LAB-*
SAN FRAN BAY;8 9
Steven Pitch!*
Page 8
July 31, 1990
C. Cleanup alternative*
Tha extant of tha eontanination and the characterieatlon of
the plum* off-site wera not clear from tha Tentative
Order. However, it la claar that there will ba no direct
remediation measure taken. Instead, tha remediation of
contamination off-site is proposed as a "contingency* plan.
It depends solely on tha on-site containment process. This
process involves tha opsration of 3 extraction tranches to
"pull bade" and raoovar. contaminants from tha groundvatar
off-site. Tha Order, on the other hand, specifically
states that tha effectiveness of such proposed continganoy
plan has not baan demonstrated by currant data. Is there
another contingency plan in wait in ease the proposed one
fails?
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KCKW. Vf«B
August 2, 1990
AUG fi 2
QUALITY CON TOOL BOARD
John Wolfendei
Regional Water Quality Control Board
San Francisco Bay Region
1800 Harrison Street, 7th Floor
Oakland, California 94612
Re: Intersil, Inc.'s Response to Comments by DOHS, Office
of Drinking Water, Concerning Intersil/Siemens Site
Tentative Order
Dear John:
This letter presents Intersil's position regarding comments
submitted to the Regional Board by the Department of Health
Services, Office of Drinking Water (NODWN) dated July 11, 1990,
concerning ODW's review of the Tentative Order for the
Intersil/Siemens proposed Superfund site. At the outset, we wish
to express our complete agreement with Regional Board staff
statements that ODW's suggested use of a carcinogenic hazard
index ("CHI") of one or a 10"6 carcinogenic risk level as cleanup
standards are inappropriate and should be rejected.1 Intersil's
comments encompass many of the points raised by Regional Board
staff in the Responsiveness Summary (Appendix C to the Tentative
1 Intersil also notes that no branch or office of the
Department of Health Services commented on Intersil or Siemens' /
On-Site and Off-Site RI/FS Reports, or on the Baseline Public
Health Evaluation prepared by Clement Associates under contract
to the RWQCB. In fact, in a letter dated January 22, 1990 from
David Wang, Chief, Site Mitigation Unit, Toxics Division,
Region 2 to John Wyss of Siemens Components, inc., the
Department specifically asked to be removed from the mailing list
for this Site.
< W;:-,! <-- 37F B'(It:-;? P«
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John .Wolfenden
August 2, 1990
Page 2
O^dcr), and are intended to supplement that summary. Our
comments are as follows:
A. v The Regional Board Should Reiect ODW's Suggested
"Terminus Risk Level?1 of 10* *, ODW's "Policy Guidance
for Direct Domestic Use of Groundwater Contaminated
with Toxic Substances", and ODW's Suggested Use of a
Carcinogenic Hazard Index of One, Because They are not
ARARs.
In its comments to the Regional Board, ODW stated that the
proposed cleanup levels for the A- and B- zones are appropriate
given the potential future use of these aquifers. With respect
to proposed cleanup levels in the C-zone however, ODW indicated
some concern.2
The Tentative Order has established C-zone cleanup levels
Consistent with the Regional Board's determination that
H[a]chieving drinking water quality is an ARAR for this site."
Tentative Order, Finding No. 18, p. 12. That is, groundwater
cleanup standards for the site are EPA Maximum Contaminant Levels
("MCLs"), California Department of Health Services ("DOHS") MCLs,
and DOHS Recommended Drinking Water Action levels ("RDWALs").
Id. These cleanup standards are derived from federal and state
standards, requirements, criteria and limitations, and therefore
constitute ARARs within the meaning of Section 121(d)(2) of
CERCLA, as amended by SARA, 42 U.S.C. S 9621(d)(2). In contrast,
ODW's recommended use of a CHI of one and 10*6 carcinogenic risk
level are not ARARs and should not be used to establish cleanup
levels.
2 As a factual mater, ODW's contention that the C-zone
should have lower cleanup levels is incorrect. First, data
collected to date by Intersil and Siemens' consultants indicates
that the A-, B-, and C-zones in the vicinity of the
Intersil/Siemens Site are part of a shallow water bearing zone
that is separated from the Deeper Aquifers by a 75-foot-thick
regional aquitard. See, e.g.. Tentative Order, Finding No. 6,
p. 3. There is evidence suggesting that the B- and C-zones are
hydraulically connected in the Site region; but there is no
evidence of any hydraulic connection between these two zones and
the Deeper Aquifers. Second, no evidence has been found to
support ODWs statement that the C-zone la an existing domestic
water supply source in the vicinity of the Site. Instead,
available information indicates that the municipal supply wells
in the region draw water from the Deeper Aquifers.
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John Wolfenden
August 2, 1990
Page 3
% In order for ODW's recommended use of a CHI of one, a
carcinogenic risk level of 10'*, or the "Policy Guidance for
Direct Domestic Use of Groundwater Contaminated with Toxic
Substances" to rise to the level of an ARAR, they must, among
other things, be "promulgated." 42 U.S.C. S 9621(d)(2)(A)(ii).
To be "promulgated," ODW's suggested approach must be "generally
applicable" and "legally enforceable." 40 C.F.R.
S 300.400(g)(4). The approaches suggested by ODW to establish
cleanup levels meet neither of these criteria.
First, standards that are inconsistently applied are not
"generally applicable" standards. See, e.g.. 42 U.S.C.
S 9621(d)(4)(E).3 RWQCB staff communications with DOHS
representatives, and a review of actions taken at certain DOHS-
lead Superfund sites, indicate that ODW's recommended procedures
are not consistently applied within DOHS.
RWQCB staff discussions with Jeff Wong of DOHS' Toxics
Eiar.ch (Sacramento), reveal that the Toxics Branch was "unaware
of any [DOHS] requirement that the CHI using MCLs in the
denominator was required to be less than one for cleanup levels."
Responsiveness Summary, p. 3. In addition, DOHS recently
approved cleanup levels that exceeded a 10* * risk level at a
State Superfund site in Palo Alto. See DOHS Fact Sheet No. 4 for
Stage 1 FS, Aydin Energy State Superfund Site, Palo Alto,
California (June 1990). These examples demonstrate that the
approach espoused by ODW in its comments has not been
consistently (if at ail) applied and therefore is not "generally
applicable" so as to qualify as an ARAR under Section 121(d)(2)
of CERCLA, or under 40 C.F.R. S 300.400(d)(4).
Second, ODW's proposed methods and policies must be
"legally enforceable" to be an ARAR. In order to be legally
enforceable, ODW's recommended methods and policies must
constitute a "substantive rule" (i.e.. one enacted by an
administrative agency pursuant to statutory delegation). In this
case, ODW's use of a CHI of one and a 10*6 carcinogenic risk
level is at best a general statement of policy, the application
3 In addition, for a cleanup standard to be generally
applicable, it must be appropriate for use as a cleanup standard
for all sites. 55 Fed. Reg. 8746. The "Policy Guidance for
Direct Domestic Use of Groundwater. . ." involves guidelines
whereby the Public Water Supply Branch of DOHS would consider the
later use of treated groundwater in a domestic water supply
distribution system. Thus, the policy does not appear to apply
in the context of establishing cleanup levels for aquifers such
as the A-, B- and C-zones beneath the Intersil/Siemens Site.
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John Wolfenden
August 2, 1990
Page 4
6^ which is apparently inconsistent even within the different
offices and branches of OOHS. Because ODH's policies are not
legally enforceable, they are not ARARs.4
B. x The CHI Equation Used by ODW is Technically Flawed
with Regard to Maintaining a Specific Incremental
Cancer Risk Goal, and Therefore Should not be Used to
Develop Cleanup Standards at the Site.
In its comments, ODW sets forth its equation to calculate
the CHI. Intersil's analysis of that equation reveals that the
equation is inconsistent with ODW's stated goal of an incremental
cancer risk of 10* *. The CHI equation used by ODW appears to be
derived from calculations in the California Site Mitigation
Decision Tree Manual (the "Manual11). The Manual bases its risk
calculations on DOHS Applied Action Levels (AALs). For
carcinogens, AALs are based on a maximum exposure level ("MEL")
that produces one adverse effect in a population of one million
exposed receptors, or an incremental carcinogenic risk of 10*6.
The MELs are derived from toxicity studies such as
epidemiological research or long-term animal bioassays. .AALs are
based entirely on health effects and do not consider the
limitations of technology, whereas Action Levels (ALs) and
Maximum Contaminant Levels (MCLs), are health-based values
modified as necessary to consider cost and technical limitations.
AALs are specific to the chemical, the receptor, and the medium
of exposure. The procedures in the Manual call for summing the
ratios of the chemical concentration to the AAL over the
chemicals and the exposure route. If this sum is greater than
one for carcinogens, the total incremental carcinogenic risk to a
receptor is greater than 10**.
The CHI equation used by ODW is similar in form to the
equation used in the Manual with the following significant
difference: ODW's equation allows for the use of AALs, ALs, or
4 Lead and support agencies nay consider other
advisories, criteria, or guidance in establishing cleanup
standards. 55 Fed. Reg. 8746. "To be considered" factors
("TBCs") may be considered in developing cleanup levels and the
like, but unlike ARARs, they are not binding cleanup standards
that must be achieved. At this Site, the RWQCB actually
considered the various points raised in ODW's comments in the
context of the remedial alternatives that evaluated cleanup to
background. See Tentative Order, Finding Nos. 13.1.6, 13.2.6,
and 13.3.6, pp. 7-9. The RWQCB rejected these alternatives
because of considerations based on time to cleanup, cost and
groundwater conservation. ldx» Finding No. 16, p. 12.
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John Wolfenden
August 2, 1990
Page 5
in calculating the CHI. If AALs are used in the CHI
equation, a CHI of one indicates a total incremental carcinogenic
risk of 10' *. If ALs or MCLs are used in the CHI equation
however ,v a CHI of one nay not indicate a total incremental
carcinogenic risk of 10'*, because ALs and MCLs consider
technical limitations. In ODW's comments, 10' 6 is specified "as
the terminus risk level whenever this level of protection can be
accomplished with reasonable and cost effective operation
measures," and ODW then recommends using the CHI equation to
develop groundwater cleanup goals. However, because the CHI
equation allows the use of ALs and MCLs in calculating the CHI,
the CHI equation may be inconsistent with ODW's stated goal of
developing cleanup levels that result in a total incremental
carcinogenic risk of 10' *. Use of ODW's CHI of one would likely
result in the development of "random risk levels" at different
RWQCB-lead Super fund sites, with the decisions regarding cleanup
levels lacking technical or economic support. See Responsiveness
Summary, p. 3.
In addition to the problems identified above, ODW's approach
for calculating the CHI fails to consider site-specific factors,
as required by the formula in the Decision Tree Manual. The
final equation, on which the CHI equation appears to be based,
should therefore not be taken straight from the Manual and
applied without first considering the proceeding calculations and
considering various site-specific issues. For instance, the risk
assessment in Intersil's On-Site Report was a site-specific risk
assessment, performed in accordance with EPA guidance.
Characteristics of the Site and vicinity were incorporated into
the risk assessment to determine the risks presented at the Site
after remediation. Site-specific exposure scenarios and
federally-approved health effects criteria developed from
toxicity studies were used to determine the risk to receptors
after remediation was complete. The additive and/or synergistic
effects of exposure to multiple chemicals via multiple exposure
routes was also considered in the risk assessment by totaling
the risk due to each chemical from each exposure route. The
total incremental carcinogenic risks calculated were between the
range of 10"* and 10**, the range of risks considered protective
by EPA.
Intersil's conclusion that ODW's method of calculating the
CHI is flawed is consistent with the statements of RWQCB staff
set forth at pages 3 to 4 of the Responsiveness Summary. Based
on Intersil and RWQCB staff criticisms, the RWQCB should reject
the techniques advanced by ODW to determine cleanup levels.
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John Wolfenden
August 2, 1990
Page 6
*> C. The Cleanup Levels Contained in the Tentative Order are
Fully Protective of Hunan Health and Domestic Supplies;
ODW's Suggested Risk Levels and Cleanup Standards
- v Should Therefore be Rejected.
As pointed out by Regional Board staff in the Responsiveness
Summary, ODW's suggested use of the CHI and the 10" * carcinogenic
risk level as cleanup standards is inconsistent with among other
things, the National Contingency Plan, 40 C.F.R. Part 300 ("NCP")
that was promulgated on March 8, 1990. See also Safe Drinking
Water Act, 42 U.S.C. $ 300f et seq. In accordance with the Site
Cleanup Requirements Order No. 89-038 issued by the Regional
Board, and consistent with the fact that the Intersil/Siemens
Site was proposed for listing on the National Priorities List,
Intersil performed the RI/FS in accordance with EPA guidance.
EPA guidance used to conduct the RI/FS included: the NCP, the
Superfund Health Evaluation Manual (SPHEM) (EPA 1986), the Risk
Assessment Guidance for Superfund, Human Health Evaluation Manual
(RAGS) (EPA 1989), and the Guidance for Conducting Remedial
Investigations and Feasibility Studies Under CERCLA (EPA 1988).
As discussed in the previous section, the RI/FS process at
the Intersil/Siemens Site included conducting a site-specific
risk assessment and calculating site-specific carcinogenic risk
levels. ODW's carcinogenic risk level is inconsistent with those
determined by EPA to be protective of drinking water. The NCP
states that "for known or suspected carcinogens, acceptable
exposure levels are generally concentrations that represent an
excess upper bound lifetime cancer risk to an individual of
between 10'* and 10"*." 40 C.F.R. S 300.430(e)(2). EPA's risk
level recently has been judged acceptable by the RWQCB for
cleanup to MCLs at several sites in Santa Clara County, including
the Applied Materials and Intel, Santa Clara 3 sites. RWQCB
Site Cleanup Requirements Order Nos. 89-167 and 90- ,
respectively.
D. Conclusion
The policies underlying ODW's comments are not ARARs, and
should therefore be rejected by the Regional Board. In addition,
ODW's formula for calculating the CHI appears flawed and
inconsistent with DOHS' goal of maintaining a specific
incremental cancer risk. Finally, the cleanup levels established
in the Tentative Order for the Site are fully protective of
current and future domestic water supplies.
The methods and recommendations discussed in ODW's comments
should be considered in the context of the newly revised NCP.
There, after literally years of technical input and review, EPA
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John wolfenden
August 2, 1990
Page 7
nqted that setting remediation goals within the range of 10' * to
10'6 "allows a pragmatic and flexible evaluation of potential
remedies at a site while still protecting human health and the
environment." 55 Fed. Reg. 8717. The RWQCB's method of
establishing cleanup levels therefore represents the proper
approach.
Please call if you have any questions. Thank you.
Sincerely,
wLto*JJiir\
Edward A. Firestone
cc: R. John Wyss, Siemens Components, Inc.
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00'03'«0 171*1
400 2«« 0271 S.C.UALLEV yflTER
02
Santo OOTQ NfeEsy Ufatef DfeMd
5750 ALMADEN EXPRESSWAY
SAN JOSE, CALIFOINIA 9508
TELEPHONE (406) J6M600
PACSIMIIE (408) 266 0271
AN AffltMATIVf ACTON IMflOYH
August 3.1990
Mr. Steve Morie
Regional Water Quality Control Board
1800 Harrison Street, Room 700
Oakland, CA 94612
Dear Mr. Morse:
Subject:
Comments on Intersil/Siemens and Solvent Services Clean Up Plans
In nrevlmx comment! transmitted to your staff by letters dated July 13,1990, and July 20,1990, for the
Intersil/Siemens and Solvent Services sites respectively, we have suggested that the Regional Board apply
the Carcinogenic Hazard Index approach for setting clean up level.
In response to discussions with you at a meeting on July 24,1990, and subsequent discussions with the
Department of Health Services, I agree that your methodology for computing clean up levels may be
appropriate. The District remains concerned, however, with the recommended goals resulting in 10* risk
levels for carcinogenic compounds. It is my understanding that forthcoming Recommended Public Health
Levels (RPHL's) will be based on a 104 cancer risk. As a result, the recommended goal could adversely
impact the future use of that portion of the groundwater basin.
Therefore, we urge you to require a remediation plan which will achieve a total cancer risk level of 104
in order to assure uninhibited use of the groundwater basin
Division Engineer
Groundwater Protection Division
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APPENDIX C
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' ••~ ^
Figure 1-1: REGIONAL MAP
Project No. 1218
LEVINE^FRICKE
CTXHULTIMO fMOMUHS «MO MTOOOOCOlOOfTI
JHH34JAN«Omp«
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Figure to :
MONITORING WELL LOCATOMS
LEVINE'FRICKE
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