United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R09-90/055
September 1990
&EPA Superfund
Record of Decision:
Intel (Santa Clara 111), CA
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R09-90/055
3. Recipient's Accession No.
Tltlo and Subtitle
SUPERFUND RECORD OF DECISION
Intel (Santa Clara III), CA
First Remedial Action - Final
S. Report Dale
09/20/90
7. Author(»)
8. Performing Organization Rept No.
9. Performing Organization Name and Address
10. Proiecl/Task/Work Unit No.
11. ContracUC) or Grant(G) No.
(C)
(G)
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
14.
15. Supplementary Notes
16. Abstract (Limit: 200 words)
The Intel (Santa Clara III) site includes a plant that performs quality control testing
of chemicals and electrical testing of semiconductors in Santa Clara, Santa Clara
County, California. The site is in a predominantly industrial area, and overlies a
major ground regional source of ground water, the Santa Clara Valley ground water basin.
In 1982, the State conducted a leak detection program, which identified VOC
contamination in an onsite shallow aquifer. Possible sources for the contamination may
include the accidental dumping of solvents into an acid neutralization tank, accidental
spills near an above-ground solvent storage facility, and cleaning of
solvent-contaminated pipes during plant construction. It has been determined that no
onsite source is presently contributing to ground water contamination. Since 1985,
Intel has been pumping and treating ground water using granular activated carbon as an
Initial Remedial Measure (IRM). This Record of Decision (ROD) addresses a final
solution for restoring ground water to its beneficial use. The primary contaminants of
concern affecting the ground water are VOCs including TCE.
(See Attached Page)
17. Document Analysis a Descriptors
Record of Decision - Intel (Santa Clara III),
First Remedial Action - Final
Contaminated .Medium: gw
Key Contaminants: VOCs (TCE)
b. Mentffiera/Open-Ended Terms
CA
c. COSATI Field/Group
J8. Availability Statement
I
19. Security Class (This Report)
None
20. Security Class (This Page)
None
21. No. Of Pages
118
22. Price
(Sea ANSI-Z39.18)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R09-90/055
Intel (Santa Clara III), CA
First Remedial Action - Final . .
Abstract (Continued)
The selected remedial action for this site includes installing an additional
extraction well onsite; continuing the pumping and treatment of ground water using an
existing granular activated carbon adsorption system, with regeneration of carbon
filters offsite; discharging treated water to onsite- surface water; conducting a
'treatability study to evaluate the effectiveness of pulsed pumping techniques that
enhance the removal of contaminants adsorbed to soil and allow for aquifer
equilibration; ground water monitoring;.and implementing institutional controls,
including deed restrictions to limit ground water use. The estimated present worth
cost for this remedial action is $594,400.- O&M costs were not provided.
PERFORMANCE STANDARDS OR GOALS: Ground water cleanup goals will reduce the excess
lifetime cancer risk for carcinogens from 10~4 to 10~6, and will reduce the Hazard
Index (HI) for non-carcinogens to a value of 1 or less. Chemical-specific goals
include TCE 5 ug/1' (State MCL).
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«"»«, UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
. 1235 Mission Street
San Francisco, CA 94103
RECORD OF DECISION
INTEL SANTA CLARA III SUPERFUND SITE
SANTA CLARA, CALIFORNIA
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION IX
SAN FRANCISCO, CA
SEPTEMBER 1990
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
1235 Mission Street
San Francisco, CA 94103
TABLE OF CONTENTS
PAGE
Report Sections
Declaration 1
Decision Summary . 4
Staff Report 14
Figures
Tables
Appendix B
Appendix C
Appendix D
Site Cleanup Requirements
Adopted Board Order
Responsiveness Summary
Administrative Record Index
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.-"»<, UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
?'r&>\ REGION IX
\^2J 1235 Mission Street
\i~fS San Francisco, CA 94103
RECORD OF DECISION
DECLARATION STATEMENT
SITE NAME AND LOCATION
Intel Santa Clara III Superfund Site
Santa Clara, California
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action
for the Intel Santa Clara III (SC3) Superfund site located in
Santa Clara, California, developed in accordance with the Com-
prehensive Environmental Response, Compensation, and Liability
Act of 1980, 42 U.S.C. Section 9601, (CERCLA) and, the National
Oil and Hazardous Substances Pollution Contingency Plan, 40
C.F.R. Part 300, 55 Fed. Reg. 8666 (3/9/90) (NCP)i. This decision
is based on the administrative record for this site.
The State of California concurs with the selected remedy.
ASSESSMENT OF THE SITE
_^^__-^_^^_^___^^__^_ y. .
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 the public health, wel-
fare, or the environment.
DESCRIPTION OF THE SELECTED REMEDY
The selected remedy for the Intel Santa Clara III site ad-
dresses groundwater contamination, in which trichloroethylene
(TCE) is the primary contaminant detected above drinking water
standards in the A-zone. As of November, 1989, TCE had been
detected at a maximum of 140 parts per billion (ppb) at the site.
However, breakdown products of TCE have historically been
detected in groundwater at the site, including 1,1-dichloroethane
(1,1 DCA), 1,1-dichloroethylene (1,1-DCE), cis 1,2-
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dichloroethylene (1,2-DCE), trans 1,2-dichlproethylene (1,2-DCE),
and 1,2-dichloroethane (1,2-DCA). Although vinyl chloride is
also a breakdown product of TCE, it has never been detected at
Intel Santa Clara III. In addition, 1,1,1-TCA and Freon 113, and
to a much lesser extent Freon 11, have been detected at the site.
This action represents the final remedial action to remove
contaminants from groundwater. Several response measures were
previously performed at the site by Intel Santa Clara III. The
major components of the selected remedy are:
Continue groundwater pumping from existing extraction wells
and one additional well until drinking water standards for
TCE ( 5 ppb); 1,2-DCA (0.5 ppb); 1,1-DCE (6 ppb); 1,1-DCA (5
ppb), cis 1,2-DCE (6 ppb); trans 1,2-DCE (10 ppb); 1,1,1-TCA
(200 ppb), Freon 113 (1200 ppb) and Freon 11 (150 ppb) are
achieved;
File a deed restriction to prevent the installation of a
shallow drinking water well and other subsurface activities
at the site until cleanup standards are achieved. The deed
restriction will remain in place until safe drinking water
levels are achieved;
Continue quarterly ground water monitoring at the site
during the cleanup period;
Treat extracted groundwater by using an existing granular
activated carbon adsorption (GAC) system (expanded with one
additional carbon canister, if necessary);
Discharge treated water to surface water pursuant to a NPDES
permit. The extracted groundwater is treated and then dis-
charged to a storm sewer system tributary of San Tomas
Aquino Creek;
Modify the existing extraction well lay-out if evaluations
indicate the need to do so;
'/' '
Conduct a demonstration project to evaluate the efficacy of
intermittent pumping of the extraction wells to remove
residual contaminants adsorped to soil particles.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that
are legally applicable or relevant and appropriate to the
remedial action, and is cost-effective. This remedy utilizes
permanent solutions and alternative treatment (or resource
recovery) technology, to the maximum extent practicable, and
satisfies the statutory preference for remedies that employ
treatment that reduces toxicity, mobility, or volume as .a prin-
cipal element.
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A review of the remedial action will be conducted every five
years after commencement to ensure that the remedy continues to
provide protection of human health and the environment.
Date . . r> ."C^niel W. McGovern .
Regional Administrator
EPA Region IX
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
1235 Mission Street
San Francisco, CA 94103
DECISION SUMMARY
INTRODUCTION
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 Intel Santa Clara III site. Consequently, por-
tions 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 al-
ternatives. Particularly, certain portions of Order No. 90-105
which was adopted by the Regional Board on July 18, 1990,
referred to hereafter as the "Order", and the Internal Memo dated
March 30, 1990 (Revised June 19, 1990), referred to hereafter as
the "Staff Report", accurately set forth the views and rationale
of EPA. Consequently, this Decision Summary will refer to por-
tions of those documents, and by such reference they are thereby
deemed to be incorporated into this Decision Summary.
1. site Name, Location and Description
See Section 1, and Figures 1 through 5 of the Staff Report
and Findings l and 2 of the Order.
2. Site History and Enforcement Activities
See Subsections 2.1 and 2.3 of the Staff Report and Findings
4, 5, 6, 7, and 9 of the prder.
>"' '
3. Highlights of Community Participation
The RI/FS and Proposed Plan for the Intel Santa Clara
III site were released to the public on Wednesday, April 18,
1990. These two documents were made available to the public
in the information repository maintained at the Santa Clara
City Library. A public comment period was held from April
18, 1990 through May 18, 1990, and a public meeting was held
on May 2, 1990. In addition, a final public hearing oc-
curred on July 18, 1990 at the Regional Water Quality Con-
trol Board monthly hearing. The attached responsiveness
summary provides responses to the comments submitted in
writing during the public comment period by various public
agencies and Intel. No major issues were raised by the lo-
cal community. See Subsection 2.5 of the Staff Report and
Finding 19 of the Order.
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4. Scope and Role of Response Action Within Site Strategy
This ROD addresses the entire site which consists of
contamination of the groundwater aquifer. The purpose of
this response is to prevent any further migration of con-
taminants in the groundwater, prevent any future exposure to
the public of contaminated groundwater, and to restore the
A-zone groundwater to drinking water quality. The response
action does not address soils because investigations have
not demonstrated that soils contain contaminants at levels
of concern.. :
5. summary of Site characteristics
Currently, TCE, in the A-zone aquifer, is the only
chemical detected above drinking water standards. The
horizontal extent of the plume covers an area approximately
400 feet long by 300 feet wide and extends to a depth of
27.5 feet below ground surface. Please see Subsections 2.1,
2.2, and 2.4 of the Staff Report and Finding 8 of the Order
for additional information on site characteristics.
6. Summary of Site Risks
Potential environmental pathways include those related
to contaminated groundwater. Potential human exposures to
contaminants include ingestion of and direct contact with
groundwater, and inhalation of volatilized contaminants
during showering by area residents. Residential areas are
located 1800 feet south of the site. See Appendix B of the
Staff Report for risk assumptions and risk calculations.
The primary route of exposure is to people working at
or near the facility. Currently, chemicals in the
groundwater do not contact human or environmental receptors.
There are no surface water bodies in the immediate vicinity
of the facility, and there are no drinking water supply
wells within or near the Intel Santa Clara III facility. A
municipal water system supplies water to businesses and
residents. Future exposure could only occur during excava-
tion of the site or if a shallow drinking water well was in-
stalled.
See Section 3.0, and Sub-Sections 6.3, and 6.4, and
Table 3 of the Staff Report and Finding 16 of the Order for
a detailed analysis of site risks and conclusions.
7. Description of Alternatives
Intel submitted a revised Remedial Investigation/
Feasibility Study, dated February 16, 1990. The report con-
tains the results of the subsurface investigation, a
description of the groundwater contamination, and an evalua-
tion of the interim cleanup actions, remedial alternatives,
and groundwater conservation measures. EPA and the Regional
Board staff determined that the technical information con-
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tained in the RI/FS was acceptable for developing a final
cleanup plan; however EPA, and the Regional Board, did not
accept all interpretations and recommendations contained in
the RI/FS. Specifically,. EPA and the Regional Board dis-
agreed with the portions of the RI/FS addressing: 1) Ap-
plicable or Relevant and Appropriate Requirements, 2)
Asymptotic Levels, and 3) The Selected Remedy. See Appendix
C of the Staff Report for detailed information regarding
these issues. As part of comments submitted on the Septem-
ber, 1989 draft RI/FS, Intel was informed of these areas of
disagreement. In revising the RI/FS, Intel did not address
these three areas.
As discussed hereafter EPA has determined that drinking
water standards, and the Regional Board's Basin Plan are
ARARs, that asymptotic levels for TCE have not yet been
reached at Intel Santa Clara III, and Alternative 4 is the
preferred remedy.
EPA and the Regional Water Quality Control Board
evaluated four remedial action alternatives for the Intel
Santa Clara III site in accordance with CERCLA Section 121,
the National Contingency Plan ("NCP"), and the Interim
Guidance on Superfund Selection of Remedy. December 24, 1986
(Oswer Directive No. 9355.0-19).
The Feasibility Study initially screened eleven
remedial action technologies. Technologies or their com-
ponents which were determined to be environmentally unsound,
difficult to implement, ineffective, or having limited ef-
fectiveness were eliminated from further consideration. A
summary of this evaluation is shown in Table 2 of the Staff
Report. Technologies or their components which were con-
sidered applicable were further screened based on effective-
ness, implementability and cost. Pursuant to OSWER Direc-
tive No. 9355.0-19, remedial action alternatives are to be
developed ranging from those that would eliminate the need
for long-term management (including monitoring) to alterna-
tives involving treatment that would permanently reduce the
mobility, toxicity or volume of the hazardous substances as
their principal element. In addition, containment options
involving little or no treatment, and a no action alterna-
tive are to be developed. The remedial action alternatives
developed are as follows:
Remedial Alternative 1
Remedial Alternative 1 is a "no further action" alternative,
retained for base-line comparison purposes in accordance
with CERCLA/SARA guidance. The use of remedial technologies
are not proposed at the Santa Clara III facility under this
alternative. The existing groundwater recovery, treatment
and discharge operation would be discontinued, as would any
groundwater monitoring. The total present worth cost of
this alternative is negligible.
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Remedial Alternative 2
Remedial Alternative 2 consists of the following:
o Deed restrictions
o Groundwater monitoring
o . Pumping from existing extraction wells
o Treatment with the existing Granular Activated Charcoal
.System
o Discharge of treated water to surface water under ex-
isting RWQCB NPDES permit
Total present worth cost = $386,500
Remedial Alternative 3
Remedial Alternative 3 consists of the following:
o Deed restrictions
o Groundwater monitoring
o Utilizing cyclic pumping of the existing extraction
system
o Discharge of treated water to surface water under ex-
isting RWQCB NPDES permit
Total present worth cost = $168,000
Remedial Alternative 4 , .
Remedial Alternative 4 consists of the following:
o Deed restrictions
o Groundwater monitoring
o Pumping from existing extraction wells and one addi-
tional well
o Treatment with a Granular Activated Charcoal system
(expanded with one additional carbon canister, if
necessary)
o Discharge of treated water to surface water under ex-
isting RWQCB NPDES permit
o Demonstration project that will evaluate pulsed pumping
from the extraction'wells in conjunction with com-
ponents listed above. This project will evaluate
various groundwater pumping strategies for cleaning up
residual levels of VOCs left behind in aquifer material
if normal groundwater pumping and treating has been
shown to be less effective.
Total present worth cost = $594,400
8. Summary of Comparative Analysis of Alternatives
Threshold Criteria
Overall protection of human health and the environment
Alternatives 2, 3 and 4 would be protective of human
health and the environment. Alternative 1, the "no action"
alternative is not protective of human health and the en-
vironment, because it is expected that the groundwater plume
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would continue to migrate, further degrading the aquifer.
Alternative 4 would provide the greatest protection.
Compliance with applicable or relevant and appropriate re-
quirements
Cleanup standards for this site are determined to be
the California Maximum Contaminant Levels and federal Maxi-
mum Contaminant Levels for TCE, each of which is 5 ppb. Al-
ternatives 2, 3, and 4 would meet this ARAR, but alternative
4 would reach ARAR's in the shortest time period. Spent
carbon canisters will be disposed of in a manner that com-
plies with federal and state requirements, including RCRA.
Primary Balancing Criteria
Long-term effectiveness and permanence
Alternatives 2, 3, and 4 would mitigate any potential
future risks by preventing the migration of VOCs in
groundwater, and restoring the groundwater quality of the A
zone. Long-term monitoring, operation and maintenance would
be required. The long-term effectiveness and permanence is
anticipated to be achieved in the shortest period by im-
plementing Remedial Alternative 4.
Reduction of toxicity. mobility, or volume through treatment
Alternatives 2, 3, and 4 would reduce contaminants at
the site through extraction and treatment of contaminated
groundwater. Alternative 1 would not result in a reduction
of toxicity, mobility or volume since it relies on natural
attenuation mechanisms, such as dispersion, sorption, diffu-
sion and degradation.
The existing system has proven to be effective in
reducing toxicity, mobility and volume of the groundwater
plume. However, Alternative 4 would be the most effective.
To increase the rate of VOC removal, an additional extrac-
tion well will be installed near SC3-7A, where the highest
concentrations of TCE and Freon-113 currently exist. While
groundwater containing VOCs in this area is already captured
by the existing extraction wells, installing an additional
well will steepen the hydraulic gradient, increase
groundwater velocity, shorten the groundwater flow path to
the extraction point, and thereby increase the rate and ef-
ficiency of VOC extraction. Pulse pumping will also be
implemented. The extraction system will be shut down peri-
odically to allow water levels to rebound. This will
provide contact time between shallow soils which may contain
VOCs and groundwater, and will allow VOCs adsorbed to soil
particles to desorb back into groundwater.
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Short-term effectiveness
Implementation of alternatives 2, 3, and 4 will
provide short-term effectiveness. Risks associated with
groundwater monitoring, recovery, treatment and discharge
are mitigated by the health and safety plan for the site,
and by the fact that no exposures to contaminants are an-
ticipated.
Alternative 1 will not be effective in containing the
contaminant plume.
Implementability
Alternatives 2 and 3 utilize existing recovery and
treatment systems which are already implemented at the site.
Alternative 4 utilizes existing systems and involves an ad-
ditional groundwater extraction well which can be readily
implemented.
Alternative 1, "no action", can be readily implemented
at the site as it involves discontinuing the current
remedial actions.
Cost .
The cost to implement Alternative 1 would be minimal in
comparison to the other remedial alternatives for the site.
The existing wells would need to be plugged and abandoned
and the treatment system could be disassembled and removed
from the-site.
The capital cost to implement Alternative 2 would be
low since the groundwater recovery, treatment, and discharge
systems are already in use at the site. The system requires
periodic maintenance to remain operable, and the carbon
units must be replaced every eight months. The present
worth value is $386,500 for Alternative 2.
The capital cost to implement Alternative 3 would be
low, consisting mainly of monitoring costs and cyclic pump-
ing costs. The present worth value of Alternative 3 is
$168,000.
The capital cost to implement Alternative 4 consists of
installing the additional extraction well(s). Another GAG
unit may also be needed to supplement the groundwater treat-
ment system already in .use at the site. Additional opera-
tion and maintenance will be required for the additional
system components, and the carbon units must be replaced
every eight months. The spent carbon is removed from the
site and regenerated by the manufacturer. Alternative 4 has
a present worth value of $595,400.
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Modifying Criteria
State/support agency acceptance
The State of California concurs with EPA's preferred
alternative.
Community acceptance
The RWQCB did not receive any written comments from
community members on the proposed plan for the Intel Santa
Clara III Site. Intel indicated a preference for Alterna-
tive 3.
9. ARARS
CERCLA requires that final cleanup actions conform to
all federal, state, and local applicable or relevant and ap-
propriate requirements (ARARs). ARARs for this site in-
clude:
1. Water quality goals from the Water Quality Control Plan
for San Francisco Bay Basin, RWQCB; and
2. Federal and State Drinking Water Maximum Contaminant
Levels (MCLs).
See Section 4 of the Staff report for a complete
analysis of site ARARS.
10. The Selected Remedy
Based upon consideration of the requirements of CERCLA,
the selected remedy is Alternative 4. Alternative 4 in-
cludes the following components: 1) a deed restriction, 2)
groundwater monitoring, 3) pumping from existing extraction
wells and one additional well, 4) treatment with an expanded
GAC system, and 5) discharge of treated water to surface
water under an NPDES permit. The selected remedy will also
include a requirement tot submittal of a proposal to
evaluate pulsed pumping as a demonstration project at the
site.
The goal of this remedial action is to restore
groundwater to its beneficial use. Based on information ob-
tained during the remedial investigation and on a careful
analysis of all remedial 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.
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The selected remedy will include groundwater extraction
and treatment. The system's performance will be carefully
monitored on a regular basis and adjusted as warranted by
the performance data collected during operation. (Please
see the Groundwater Self-Monitoring Report that is included
in the Board Order, and the report on pulse pumping.) Pos-
sible adjustments may include the following:
a) pulse pumping to allow aquifer equilibration and en-
courage adsorbed contaminants to partition into
groundwater.
b) installation of additional extraction wells to
facilitate or accelerate cleanup of the contaminant
plume.
c) discontinuing operation of extraction wells in areas
where cleanup standards have been attained; and
d) alternating pumping at wells to eliminate stagnation
points.
See Section 6 of the Staff Report and Finding 13 and
Specification B4 of the Order.
11. Statutory Determinations
The selected remedy is protective of human health and
the environment in that contaminated groundwater is treated
to at least maximum contaminant levels (MCLs) and falls
within EPA's acceptable carcinogenic risk range of one-in-
a-million (10~6) to one-in-ten-thousand (10~4) individual
lifetime excess cancers that may develop in a population.
In addition, the remedy complies with the requirements of
all ARAR's including federal and State MCLs and State Drink-
ing Water Action Levels. Furthermore, the selected remedy
utilizes cost effective technologies. The selected remedy
is more expensive, but it is more effective in achieving
remediation goals in thexshortest period of time. The
selected remedy will permanently and significantly reduce
the toxicity, mobility, and volume of hazardous substances
with respect to their presence in groundwater and utilizes
treatment of groundwater as a principal element.
" *!
12. Documentation of Significant Changes
The Proposed Plan for the Intel Santa Clara III site
was released for public comment in April 1990. The Proposed
Plan identified Alternative 4, groundwater extraction, as
the preferred alternative. EPA reviewed all written and
verbal comments submitted during the public comment period.
Upon review of these comments, it was determined that no
significant changes to the remedy, as it was originally
identified in the Proposed Plan, Fact Sheet #2, were neces-
sary.
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
1235 Mission Street
San Francisco, CA 94103
Staff Report on the Final Remedial Action Plan
for the Intel Santa Clara 3 Site, dated March 30,
1990 and revised on June 19, 1990.
Summary 1
1.0 Site Location & Description 2
1.1 Groundwater Resources 2
1.2 Regional Hydrogeology 2
1.3 Site Hydrogeology 3
2.0 Site History 3
2.1 Subsurface Investigation 3
2.2 Groundwater Pollution 3
2.3 Interim Remedial Actions 5
2.4 Source Identification 5
2.5 Community Relations 6
3.0 Summary of Site Risks 6
3.1 Potential Human Exposure Pathways 6
3.2 Current Use Conditions 7
3.3 Future Use Conditions 7 .
3.4 Preliminary Health Assessment 7
3.5 Environmental Risks 8
4.0 Applicable or Relevant and Appropriate 8
Requirements (ARARs)
4.1 Beneficial Use of Local Groundwater as
a Source of Drinking Water 8
4.2 State Board Resolution 68-16 9
4.3 Chemical-Specific ARARs 9
4.4 Action-Specific ARARs 9
4.5 Other Criteria "fo Be Considered 10
5.0 Description of Alternatives 11
6.0 The Recommended Selected Remedy 12
6.1 Demonstration Project 13
6.2 Regional Board Resolution No. 88-160 15
6.3 Cleanup Standards 16
7.0 Areas of Disagreement 18
7.1 Applicability of drinking water
ARARs to the SC3 site 18
7.2 The Selected Remedy 19
7.3 Asymptotic Levels 20
8.0 Conclusion 21
9.0 Recommendation "21
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
\ REGION IX
1235 Mission Street
San Francisco, CA 94103
ATTACHMENTS:
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Table 1
Table 2
Table 3
Appendix B:
Appendix C:
Appendix D:
Site Location Map - Intel Santa Clara 3.
Site Map of Intel Santa Clara 3 (showing dis-
tribution of TCE in the A Water-Bearing
Zone, August 16, 1989).
Representative Log for Intel Santa Clara 3
(Boring Log for Monitoring Well SC3-5B).
Potentiometric Surface of the A Water- Bear-
ing Without Pumping, 8 June, 1988 - Intel
Santa Clara 3.
Potentiometric Surface of the A Water-Bearing
Zone with pumping - Intel Santa Clara 3 -
August 16, 1989.
Concentration of TCE vs. Time in Monitoring
Well SC3-1 and Extraction Wells SC3-E1 and
E2. . .
Concentration of TCE vs. Time in Monitoring
Well SC3-7A.
Idealized effect of pulse pumping over time.
Federal and State drinking water standards.
>*
Remedial Technology Screening: Groundwater,
Inter SC3, Feasibility Study.
The Cancer Risk and Hazard Index Associated
With the Groundwater Cleanup Standards.
Assumptions Used to Calculate Hazard Index
and Carcinogenic Risk.
Agency Addendum for the RI/FS Report.
Self-Monitoring Program for Intel Santa Clara
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REGIONAL WATER QUALITY CONTROL BOARD
SAN FRANCISCO BAY REGION
INTERNAL MEMO
TO: Steven R. Ritchie DATE: March 30, 1990
Executive Officer (Revised June 19, 1990)
FROM: Gregory W. Bartow
Associate Engineering Geologist
SUBJECT: Staff Report on the Final Remedial Action Plan for the Intel Santa Clara 3
Site, Santa Clara
SUMMARY
This staff report contains background information used in developing the Final Remedial
Action Plan (RAP) for the Intel Santa Clara 3 (SC3) Superfund site. Groundwater below the
site is primarily polluted with trichloroethylene (TCE). Subsurface investigations by the
discharger have determined that the oval shaped plume covers an area approximately 400
feet by 300 feet The vertical extent of groundwater pollution extends to a depth of
approximately 30 feet below ground surface in the first (or "A") aquifer zone. Only trace
groundwater pollution has been found to date in any of the deeper (or "B") zone
monitoring wells.
The selected remedy includes the following components: 1) a deed restriction to preclude
future use of the A zone until cleanup standards are achieved, 2) groundwater monitoring,
3) pumping groundwater from existing extraction wells and at least one additional
extraction well, 4) treatment of pumped groundwater with an expanded granular activated
charcoal system (GAQ, 5) discharge of treated groundwater to surface water as specified
by the existing National Pollutant Discharge Elimination System (NPDES) permit, and 6)
submittal of a proposal to evaluate pulsed pumping as a demonstration project at the site.
Pulsed pumping is the cycling of extraction wells on and off in active and resting periods.
Currently there are three areas of disagreement at the site. These issues involve 1)
applicability of drinking water requirements (defined by CERCLA as applicable or relevant
and appropriate requirements or "ARARs") to the SC3 site; 2) the selected remedy; and 3)
asymptotic groundwater pollutant concentration levels. Board staff recommends that these
issues be resolved in the RAP as well as in an agency addendum to the RI/FS, rather than
in another revised version of the Remedial Investigation / Feasibility Study (RVFS).
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 EPA's acceptable Carcinogenic Risk range of
one-in-a-million (10*) to one-in-ten-thousand (10*) individual lifetime excess cancers that
may develop in a population. In addition, the remedy at least attains the requirements of
all ARARs, including Federal and State MCLs and State Drinking Water Action Levels.
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Furthermore, the selected remedy includes cost effective technologies. The selected remedy
will permanently and significantly reduce the toxicity, mobility, and volume of hazardous
substances with respect to their presence in groundwater.
1.0 SITE LOCATION AND DESCRIPTION
Intel Corporation's Santa Clara 3 Facility performs quality control of chemicals and electrical
testing of semiconductors at a site located at 2800 Northwestern Parkway, Santa Clara,
Santa Clara County (Figure 1 and 2). SC3 has been in operation since 1976.
SC3 is located in the City of Santa Clara in a relatively flat lying portion of the Santa Clara
Valley. Ground surface elevations are generally between 38 feet and 41 feet above mean
sea level
This is an industrial park setting, dominated by the electronics industry, particularly
semiconductor manufacturing. As such, the majority of the area is developed, with large
paved areas for streets and parking lots. Surface water is controlled by the storm sewer
system which directs runoff to San Tomas Aquino Creek The nearest residential areas are
located 1800 feet south of the site. Other residential areas are located 7200 feet north-
northeast of the site and 7800 feet northwest of the site. None of these residential areas are
within the area impacted by past chemical releases from SC3.
1.1 Groundwater Resources
The site overlies the Santa Gara Valley groundwater basin. Groundwater from this basin
provides up to 50% of the municipal drinking water for the 1.4 million residents of the
Santa Clara Valley. In 1989, groundwater accounted for approximately 128,000 of the
315,000 acre feet of drinking water delivered to Santa Clara Valley Water District customers.
The Intel SC3 site is a Superfund site primarily because of the past chemical releases'
potential threat .to the quality of this valuable resource.
>*
1.2 Regional Hydrogeology
The SC3 site is located near the center of the Santa Gara Valley which extends southeast
from San Francisco Bay and is bounded by the Diablo Range on the northeast, and by the
Santa Cruz and Gabilan Ranges on the southwest
The Santa Gara Valley is a large structural depression in the Central Coastal Ranges of
California. The Valley is filled with alluvial and fluvial deposits from the adjacent
mountain ranges. These deposits are up to 1,500 feet in thickness. At the base of the
adjacent mountains, gently sloping alluvial fans of the basin tributaries laterally merge to
form an alluvial apron extending into the interior of the basin.
The Santa Gara Valley groundwater basin is divided into two broad areas: 1) the forebay,
and 2) the confined area, where SC3 is located. The forebay occurs along the elevated
edges of the basin where the basin receives its principal recharge. The confined area is
located in the flatter interior portion of the basin and is stratified or divided in individual
beds separated by significant aquitards.
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The confined area is divided into the upper and lower aquifer zones. The division is
formed by an extensive regional aquitard that occurs at depths ranging from about 100 feet
near the confined area's southern boundary to about 150 to 250 feet in the center of the
confined area and beneath San Francisco Bay. Thickness of this regional aquitard varies
from about 20 feet to over 100 feet
Several aquifer systems occur in the upper aquifer zone separated by aquitards which may
be leaky or very tight Groundwater pollution at SC3 is confined to the shallowmost zone
within the upper aquifer zone.
The lower aquifer zone occurs beneath the practically impermeable regional aquitard.
Numerous individual aquifers occur within this predominantly aquitard zone and all
groundwater in this zone occurs confined (Santa Clara Valley Water District, Geology and
Water Quality, 1989).
Municipal water supply wells are generally perforated in the lower aquifer zone
Perforated intervals in City of Santa Clara water supply wells located within 2 miles of SC3
begin from 250 to 320 feet below ground surface, although sanitary seals are only installed
down to 100 feet below ground surface. Currently, the nearest municipal drinking water
supply well downgradient of the site is the City of Santa Clara's Well No. 33 located 1.6
miles north of the site.
|.3 Site Hydrogeology
Two water bearing layers, designated as the A and B zones, have been identified at SC3.
The shallowest, or A zone, has its upper boundary at about 10 to 18 feet deep, and lower
boundary about 25 to 27 feet deep. The top of the B zone is 29 to 36 1/2 feet deep, and
the bottom of the B zone is between 35 1/2 to 43 feet deep. The A and B zones are
separated by an aquitard of 5 to 10 feet of silty day to clayey silt Below the B zone is the
next confining layer, which appears to be at least 4 feet thick as determined from over
drilling of wells SC3-4B, 5B and 6B. The boring log for monitoring well 5B, shown on
Figure 3, can be considered a representative^iog for the site. However, it should be noted
that there is considerable variation in lithology and thickness of the A and B zones, as well
the aquitard between the A and B zones, across the site.
A potentiometric surface map for the site, under non-pumping conditions, is shown in
Figure 4. The gradient is fairly uniform at 0.005 toward N 15» E to N 15° W. A
potentiometric surface map for water levels measured during on-site pumping conditions is
shown in Figure 5.
10 SITE HISTORY
2.1 Subsurface Investigation
In early 1982, the Board initiated a leak detection program to define the extent of leakage
from underground storage tanks and pipes in the South Bay area. As a result of these
efforts, subsurface investigations in the A zone at SC3 detected trichloroethylene (TCE);
1,1,1-trichloroethane (1,1,1- TCA); 1,1-dichloroethylene (1,1-DCE); 1,1-dichloroethane (1,1-
DCA); 1,2-dichloroethane (1,2-DCA); as 1,2-dichloroethylene (as 1,2-DCE); trans 1,2-
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dichloroethylene (trans 1,2-DCE); Freon 113; and Freon 11.
Since 1982, Intel has installed eleven A zone monitoring wells and four B zone monitoring
wells to define the vertical and horizontal extent of the plume. Following installation of A
zone monitoring wells SC3-8A, 9A, and 10A in 1987, Board staff concluded that the vertical
and horizontal extent of the plume had been defined. The oval shaped plume covers an
area approximately 400 feet by 300 feet The vertical extent of ground water pollution in the
A zone extends to the bottom of well SC3-3 at a depth of 27.5 feet below ground surface.
The vast majority of samples collected and analyzed from the B zone have not detected any
volatile organic chemicals (VOCs). Occasionally, VOCs have been detected in the B zone,
usually at concentrations below 1 ppb. Board staff believes that the VOCs detected in the
B zone are likely due to sampling and/or laboratory contamination. In addition, trace
amounts of VOCs may have been introduced to the B zone during installation of B zone
monitoring wells.
2.2 Ground water Pollution
Groundwater samples from SC3 monitoring wells have been collected and analyzed on 39
separate occasions between July 1982 and November 1989. Currently, TCE, in the A zone,
is the only chemical detected above drinking water standards. However, as described
above, other VOCs have been detected in the A zone. Following is a list of chemicals
detected at least once since 1982 and the maximum concentration of the chemical. In
addition, the maximum 1989 level for each chemical is shown:
Chemical
Maximum Historical
Concentration
(82-'89)
1989 Maximum
Concentration
Drinking
Water
Criteria1
1 , 1 DCA
1,2 DCA
1 , 1 DCE
cis-1,2 DCE
trans- 1,2 DCE
1,1,1 TCA
TCE
Freon 113
Freon 11
8.2
16.0
84.0
<7.92
<7.92
810.0
490.0
1300.0
2.8
ND
ND
ND
ND
ND
2.1
230.0
35.0
ND
5.0
0.5
6.0
6.0
10.0
200.0
5.0
1200.0
150.0
All concentrations in parts-per-billion (ppb)
ND - Not Detected (detection levels ranged between 0.5 and 5.0
.
Proposed or adopted CA State Maximum Contaminant Level
2Reported as total 1,2DCE
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2.3 Interim Remedial Actions
Intel has been extracting A zone groundwater from two extraction wells since February
1985. A general decline in groundwater pollution levels has been observed in all but one
of the wells at SC3 since pumping started. Prior to implementing Interim Remedial Actions,
the groundwater contained levels of TCE up to 490 parts per billion (ppb), 1,1,1-TCA up to
810 ppb, 1,1-DCE up to 84 ppb, and Freon 113 up to 1300 ppb. Figure 6 shows the
concentration of TCE in three representative wells at the site. The exception to the general
decline in pollution levels is monitoring well SC3-7A. Figure 7 shows the concentration of
TCE over time in well SC3-7A. Pumped groundwater is treated and then discharged to a
storm sewer system tributary to San Tomas Aquino Creek as specified under NPDES Permit
#CA0028941.
2.4 Source Identification
No source of the groundwater pollution has ever been positively identified at the site.
Three possible sources have been proposed and, to the extent practical, evaluated. One
possible source of the pollution is leaks that may have occurred from the acid waste
neutralization tank (AWN). The AWN was installed in 1976 and consists of an open top
metal neutralization tank in a concrete containment vault which is open to the atmosphere.
Two soil samples were collected from monitoring well SC3-1, installed 8 feet from the AWN
in 1982. The soil samples were collected from 4 and 7 feet below ground surface and
contained 48 and 18 ppb TCE respectively. In 1984, Intel removed the AWN at SC3.
According to Intel, the removed AWN was not leaking and the vault containing the system
showed no signs of moisture or corrosion.
Intel admits that accidental dumping of solvents into the acid neutralization tank has
occurred in the past However, based on the decline in concentration of VOCs in SC3-1
and SC3-E1 (see Figure 3), there does not appear to be any lingering source of VOCs which
may have leaked from the AWN. In addition, Board staff believes that any VOC's that
would have leaked out of the AWN would have migrated directly into the groundwater,
since the base of the AWN is at or below tne water table. As such, it is now difficult to
identify the AWN, conclusively, as a source.
Another possible source is accidental spills near the above ground solvent storage facility.
Prior to 1983, outside storage was above ground on a concrete pad which was covered and
fenced. In 1983, an above ground, double-contained storage facility was created with a
maximum capacity of five 55 gallon drums. A soil gas survey conducted 1989, at the
request of the Regional Board, included five points near the solvent storage facility. The
results from the soil gas survey do not indicate any major lingering source in this vicinity.
The third possible source of groundwater pollution is that solvents were used to dean out
the pipes put in place during the construction of the SC3 building. As previously stated, a
soil gas survey was conducted in 1989 to investigate the possibility of a source of VOCs in
soils at the site. A total of 36 separate locations were sampled. No evidence indicating a
vadose zone source of VOCs was discovered.
EPA's consultant, Metcalf & Eddy, reviewed the soil gas survey report and stated in a letter
dated November 28,1988, "Based on the low levels of detectable VOCs, namely Freon 113,
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Revised June 19, 1990
TCA and TCE, we are in general agreement with the report's conclusions that 1) no
sources of VOCs exist or are identifiable in the surveyed area, and 2) soil venting is not
suitable for remediation at SC3. It is our opinion that further efforts to identify a site
source(s) of VOC contamination in the groundwater will prove futile."
Positive identification of a pollution source during groundwater pollution site investigation
and evaluation is useful in ensuring that 1) the source is no longer contributing to
identified groundwater pollution, and 2) the affect of residual pollutants present in the
source area is considered in developing a remedial action plan for the site. While positive
identification of a pollution source has not been possible at SC3, by performing the
evaluations of potential sources described above, it has been possible to determine that
there is no source continuing to contribute pollutants to SCS's existing groundwater
pollution and to develop a remedial action plan that considers the possible affect of residual
pollutants in the vadose zone. As such; Board staff concurs with Metcalf & Eddy's
conclusion that no further action to identify a pollution source at SC3 be undertaken.
2.5 Community Relations
An aggressive Community Relations program, has been established by the Board's
Community Relations staff for all Santa Clara Valley Superfund sites, including the SC3 site.
A Community Relations Plan for SC3 was developed and distributed in September 1989.
the Plan calls for mailing a total of three fact sheets to the community during key stages
of the Superfund program. An Administrative Record was compiled for the site. A copy of
the Administrative Record is located at the Santa Clara City Library. The index to the
Administrative Record is included as an appendix to this report
The Regional Board held an initial public hearing oh the proposed RAP at their regular
meeting on Wednesday, April .18,1990. This began the 30 day public comment period. A
public meeting was held on May 2,1990 at 7:00 pm at the Santa Clara County Convention
Center. All comments received regarding the RAP were addressed in the Responsiveness
Summary attached to this staff report
. >'
A final public hearing and consideration of the final RAP is expected to occur on July 18,
1990 during the Regional Board's regular meeting.
3.0 SUMMARY OF SITE RISKS
The draft Public Health Evaluation (PHE) was prepared by Geraghty and Miller and
submitted to the Regional Board in May, 1989. This report was reviewed by the Board's
contractor ICF Clement and an EPA toxicologist A revised PHE addressing both ICF
Clement and EPA's comments was submitted to the Board on February 20, 1990.
3.1 Potential Human Exposure Pathways
In order for a chemical to pose a human health risk, a complete exposure pathway must be
identified. A complete exposure pathway consists of four elements: 1) a source and
mechanism of chemical release to the environment, 2) an environmental transport medium
(e.g., air or soil) for the released chemical, 3) a point of potential human contact with the
contaminated medium (known as the exposure point), and 4) a human exposure route
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(e.g., inhalation) at the contact point Exposure pathways are evaluated for both current
and potential future land uses at the site.
3.2 Current Use Conditions
Land uses surrounding the SC3 site are predominantly light industry. The nearest
residences are approximately 1800 feet south of the site and 7200 feet north-northeast of the
site. Therefore, the primary exposures under current conditions are to individuals working
at or in the vicinity of the SC3. Potential exposures to workers were not evaluated in this
assessment since these exposures are outside the scope of a CERCLA/SARA baseline PHE.
The likelihood of exposure was evaluated for each potentially contaminated environmental
medium: soil, ground water, surface water, and air. No pathways were identified as having
a moderate or high likelihood of occurrence and, therefore no current-use conditions were
quantitatively evaluated in the assessment Board staff, ICF Clement, and EPA concur with
this exposure assessment approach.
3.3 Future Use Conditions
In the future, in the absence of deed restrictions, the SC3 site could be converted to
different land uses, including retail business or residential If this change were to occur
without remediation of the site, on-site workers or residents could potentially be exposed to
site pollutants. Conversion of the property to residential uses is less likely than conversion
to other industrial or commercial uses, due to the industrial nature of the adjacent
properties. However, residential uses would lead to higher potential exposures than would
commercial uses, due to the possibility of a private well being installed in the A zone.
Since Intel plans on obtaining a deed restriction, future use was not evaluated.
Generally, Board staff has required that the future risk at a site be based on the risk of
drinking and showering with water from a hypothetical onsite well This calculation was
not required at the SC3 site since a deed restriction is planned. The deed restriction will
prohibit the installation of any well into the A zone for any purposes other than site
remediation (see Section 6.0). The Board's PHE contractor, ICF Clement, concurs with this
decision. Board staff believes this is an appropriate decision since the groundwater
pollution is confined onsite and in the shallowmost aquifer.
Board staff estimated the baseline risk at the site based on the assumptions presented in
Section 6.4 and Appendix B. Using the maximum concentrations of chemicals detected in
the groundwater in 1989, the Carcinogenic Risk and Hazard Index, as defined in Section
4.4, associated with drinking and showering with water from the A zone is 7x10* and 0.001
respectively. As such, the Carcinogenic Risk currently is within EPA's acceptable
Carcinogenic Risk range of one-in-a-million (1x10*) to one-in-ten-thousand (1x10*) individual
lifetime excess cancers that may develop in a population. However, the concentration of
TCE currently exceeds ARARs. It is ARARs then, that are driving the cleanup at the site,
rather than the Carcinogenic Risk (see Section 4.0).
3.4 Preliminary Health Assessment
A Preliminary Health Assessment for the site was prepared for the.site by the Agency for
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Toxic Substances and Diseases Registry, U.S. Public Health Services, dated January 19, 1989.
This report states that based on available information, this site is not considered to be of a
current public health concern because of the apparent absence of human exposure to
hazardous substances. Board staff concurs with this assessment
3.5 Environmental Risks
EPA requires that risks at the site be evaluated relative to the affects on critical habitats and
endangered species.
The SC3 site is located in the geographic center of the City of Santa Clara, in a commercial-
light industrial setting. No parks or surface water are adjacent to the site. Over 90% of
the property is covered with blacktop or a building slab. Chemical constituents are only
present in the shallow groundwater. Therefore, Board staff believes that there is no
probable pathway for exposure to critical habitats or endangered species.
4.0 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARs)
Under Section 121(d) of CERCLA, as amended by SARA, the selected remedy must achieve
a level or standard of cleanup that assures protection of human health and the
environment In addition, CERCLA requires that remedial actions achieve a level or
standard or cleanup that meets legally applicable or relevant and appropriate requirements,
standards, criteria or limitations (ARARs).
ARARs associated with the site can generally be separated into two categories: 1) ambient
or chemical specific requirements that set health or risk-based concentration limits or ranges
for particular chemicals, and 2) performance, design, or action-specific requirements that
govern particular activities. For this site, the selection of ARARs is dependent on the
defined beneficial use of groundwater as a source of drinking water.
4.1 Beneficial Use of Local Groundwater as A Source of Drinking Water
The regulatory framework associated with the cleanup of groundwater and soil at the site is
driven by the beneficial (current or potential) use of local groundwater. As stated in 40
CFR 300.430(a)(ii)(F), "The goal of EPA's Superfund approach is to return usable ground
waters to their beneficial uses wherever practicable within a timeframe that is reasonable
given the particular circumstances of the site". Drinking water is considered to be the
highest beneficial use and affords the greatest level of protection and cleanup.
As required by the California Porter-Cologne Water Quality Control Act, the Regional Board
defines the beneficial uses of various water bodies in greater San Francisco Bay Area..
Water bodies and their beneficial uses are presented in The Water Quality Control Plan for
the San Francisco Bay Basin (Basin Plan). The Basin Plan, as adopted by the Regional
Board on December 16, 1986, and approved by the State Water Resources Control Board
(SWRCB) on May 21,1987, has been promulgated and is an ARAR for this site. In the
Basin Plan, the Regional Board classifies the shallow aquifers in the area of the SC3 plume
as "potentially suitable for municipal or domestic water supply". In addition, the Basin Plan
states that the "use of waters in the vicinity represent the best information on* beneficial
uses". '
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March 30, 1990
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On March 15, 1989, the Regional Board incorporated the SWRCB Policy of "Sources of
Drinking Water" into the Basin Plan. The policy provides for a Municipal and Domestic
Supply designation for all waters of the State with some exceptions. Ground waters of the
State are considered to be suitable or potentially suitable for municipal or domestic supply
with the exception of: 1) the total dissolved solids in the groundwater exceed 3000 mg/L,
and 2) the water source does not provide sufficient water to supply a single well capable of
producing an average, sustained yield of 200 gallons per day. Based on data submitted by
Intel, Board staff has concluded that neither of these two exceptions apply to the A zone at
SC3. Thus, the A zone at SC3 is a potential source of drinking water.
4.2 State Board Resolution 68-16
On October 28, 1968, the State 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 State waters unless it is demonstrated that any
change would be consistent with the maximum public benefit and not unreasonably affect
beneficial uses. The original discharge of waste to the groundwater at this site was in
violation of this policy; therefore, the groundwater quality needs to be restored to its
original quality to the extent reasonable. For the purpose of establishing cleanup objectives,
the shallow groundwater at the site is designated a potential source of drinking water, and
protective levels shall be those levels which have been established as protective of drinking
water. A beneficial use of the groundwater is drinking water. Establishing a cleanup level
which maintains this beneficial use should attain the requirements of Resolution 68-16.
Stale Board Resolution 68-16 is an ARAR for the site.
4.3 Chemical-Specific ARARs
Chemical-specific ARARs for the SC3 site are Federal and State of California drinking water
standards. Each is relevant and appropriate to set cleanup standards at the site. A list of
Federal and State drinking water standards are presented in Table 1.
>'
4.4 Action-Specific ARARs .
Primary remedial actions evaluated at SC3 incorporate groundwater extraction and
treatment Groundwater extraction and treatment involves pumping, treating, and
discharging the treated groundwater to surface waters and/or reinjecting it into the aquifer.
The following ARARs are associated with components of groundwater extraction and
treatment
Discharge to Surface Water - Substantive National Pollutant Discharge Elimination System
(NPDES) permit requirements would apply to extracted and treated ground water discharges
to surface waters. These are primarily effluent limitations and monitoring requirements.
Intel currently has a NPDES permit for discharging treated groundwater extracted at the
SC3 site-to San Tomas Aquino Creek
Carbon Adsorption - Groundwater/ extracted at SC3, will continue to be treated by Granular
Activated Carbon (GAQ adsorption. GAC use requires consideration of ARARs- associated
with carbon regeneration or disposal Currently, the GAC canisters .are replaced
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approximately once per year. The spent GAC canisters are removed from the site and
regenerated by Calgon Carbon Corporation.
Regeneration of activated carbon, using a high-temperature thermal process, is considered
"recycling" under both Federal and California hazardous waste regulations. Transportation,
storage, and generation of hazardous waste for recycling must comply with requirements in
RCRA and California hazardous waste control regulations. On-site storage of contaminated
carbon may trigger substantive requirements under municipal or county hazardous materials
ordinances. If the spent carbon is hazardous waste, construction and monitoring
requirements for storage facilities may also apply.
4.5 Other Criteria To Be Considered
In establishing selected remedial alternatives, EPA and the Regional Board consider various
procedures, criteria and resolutions. These "to be considered" criteria (TBCs) do not rise to
the level of ARARs, but are relevant to the cleanup of the site. The following discussion
presents selected criteria relevant to the selection of remedial alternatives.
State Criteria for Groundwater Geanup - Drinking Water Action Levels are health-based
concentration limits established by DHS to limit public exposure to substances not yet
regulated by promulgated standards such as MCLs. They are advisory standards that
would apply at the tap for public water supplies, and do not rise to the level of ARARs.
Nonetheless, they have been considered in developing cleanup standards for the SC3 site,
especially for those chemicals that currently have action levels established and that have
proposed MCLs. Groundwater criteria, to be considered for determining cleanup levels, are
presented in Table 1.
Health Advisories - Pollutants in the groundwater at SC3 are divided into: 1) possible or
probable cancer-causing substances (carcinogens), and 2) toxins (noncarcinogens). When
carcinogens are present, and a threat of exposure to these carcinogens exists, a potential
risk is present There is no "zero-risk" level associated with the threat of exposure to
carcinogens. The potential aggregate effects of carcinogens are evaluated by use of
Carcinogenic Risk numbers, usually expressed as the number of excess cancers that may
develop in a population; Le., the one-in-a-million or 104 risk. The Regional Board and EPA
consider that for a remedial action of a drinking water source to be protective, it should
have a Carcinogenic Risk that is as dose as possible to one-in-a-million (104) individual
lifetime excess cancers that may develop in a population. If meeting a Carcinogenic Risk of
10* is infeasible, the remedial action must at least have a Carcinogenic Risk that falls within
a range of 10* to one-in-ten-thousand (104) individual lifetime excess cancers that may
develop in a population.
The Hazard Index is the method used by the Board to assess the public health risk
associated with the presence of multiple noncarcinogens. Potential risks are assessed for
noncarcinogens by taking the ratio of the chronic daily intake (CDI) to the reference dose
(RfD). In general, if the CDI:RfD ratio is less than one (i.e., if the daily intake is below the
designated health criterion), the pollutant is considered unlikely to be associated with any
significant health risks.
Toxic effects of noncarcinogenic chemicals are initially assumed to be additive, in
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accordance with EPA guidance on health risk assessment of complex mixtures. For each
scenario, the CDI:RfD ratios for each individual chemical are summed to produce a Hazard
Index for total toxic risks. If the Hazard Index is less than one, the combined intake of
chemicals by the exposure route under consideration is unlikely to pose a health risk
The Hazard Index and Carcinogenic Risk associated with the cleanup standards for SC3 are
presented in Section 6.3.
5.0 DESCRIPTION OF ALTERNATIVES
The Feasibility Study initially screened eleven remedial action technologies. Technologies
or their components which are environmentally unsound, difficult to implement, ineffective,
or have limited effectiveness were eliminated from further consideration. A summary of
this evaluation is shown on Table 2. Technologies or their components which were
considered potentially applicable for SC3 were further screened based on effectiveness,
implementability and cost The remedial technologies that survived the further screening
were assembled into a group of alternatives as follows:
Remedial Alternative 1
Remedial Alternative 1 is a "no further action" alternative, retained for base-line comparison
purposes in accordance with CERCLA/SARA guidance. Remedial technologies are not
implemented at SC3 under this alternative. The existing ground water recovery treatment
and discharge operation would cease, as would any ground water monitoring. The total
present worth cost of this alternative is negligible.
Remedial Alternative 2
Remedial Alternative 2 consists of the following:
Deed restrictions
Ground water monitoring
Pumping from existing extraction wells
Treatment with the existing GAC system
Discharge of treated water to surface water under existing NPDES permit
Total present worth cost - $386,500
Remedial Alternative 3
Remedial Alternative 3 consists of the following:
Deed restrictions
Ground water monitoring
Cease continuous pumping from existing extraction system with some cyclic
pumping
Keeping the existing extraction system in stand-by mode, with some cyclic pumping
Discharge of treated water to surface water under existing NPDES permit
Total present worth cost = $168,000
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Remedial Alternative 4
Remedial Alternative 4 consists of the following:
Deed restrictions
Ground water monitoring ,
Pumping from existing extraction wells and one additional well
Treatment with a GAC system (expanded with one additional carbon canister, if
necessary)
Discharge of treated water to surface water under existing NPDES permit
Total present worth cost = $594/400
6.0 THE RECOMMENDED SELECTED REMEDY
Intel's recommended remedy is Alternative 3. However, based upon the conclusions in the
FS that Alternative 4 could potentially achieve long-term effectiveness and permanence and
reduction of toxicity, mobility and/or volume of VOCs in the shortest time, Board staff
believes that Alternative 4 is a more appropriate remedy than Alternative 3 for the site.
Furthermore, Alternative 3 would not necessarily attain cleanup standards. Board staff
therefore recommends modifying the proposed plan to include Alternative 4 in the selected
remedy.
Based on Alternative 4, the selected remedy includes the following components: 1) a deed
restriction, 2) groundwater monitoring, 3) pumping from existing extraction wells and one
additional well, 4) treatment with an expanded GAC system, and 5) discharge of treated
water to surface water under existing NPDES permit As discussed in Section 6.1, Board
staff also recommends modifying the selected remedy to include a requirement for submittal
of a proposal to evaluate pulsed pumping as a demonstration project at the ate.
The institutional control of a deed restriction will prohibit the installation of a shallow
drinking water well at the site. Since the entire plume is located beneath the site, the deed
restriction will provide an extra margin of safety, should the property be sold during the
long term remediation phase. This phase is expected to last 11 years, or into the indefinite
future. Intel has submitted the following draft language to be used in the deed restriction
with the County of Santa Clara:
"No person shall drill, bore, excavate or otherwise construct a shallow well as
defined below, for the purpose of extracting water for beneficial use as defined in
Section 13050 of the California Water Code. A shallow well is defined as any well,
boring or excavation that allows extraction of water from any water bearing zone
above a depth of approximately 50 feet (approximately 10 feet below mean sea level)
below 1989 ground surface.
It is intended that the burden of this restrictive covenant shall run with the land
and any and all successors to any interest in the land shall be bound by this
covenant .
This restrictive covenant may be waived, modified or removed only subsequent to a
written decision from the California Regional Water Quality Control Board, San
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Staff Report - Page 13
March 30, 1990
Revised June 19, 1990
Francisco Bay Region and the Santa Clara Valley Water District that specifically
approves: the construction of a shallow well; extraction of water from a shallow
zone; and, beneficial use of the extracted water.
Nothing in this negative covenant shall restrict drilling, boring or excavation for any
purpose not described above, including: borings for the purpose of testing soils;
excavation for foundations or underground utilities; wells for monitoring the quality
of the water, or borings to define the geology."
Ground water monitoring will continue at the site during the cleanup period. An additional
monitoring well will be installed between wells SC3-1 and SC3-7A. Water levels will be
measured to verify that hydraulic control of the groundwater pollution is maintained.
Water samples will continue to be collected to verify that cleanup is proceeding and that
there is no migration of VOCs, above cleanup standard levels, beyond current boundaries
or into the deeper 8 zone. The frequency of monitoring will gradually be decreased once
cleanup standards have been achieved.
Groundwater extraction will continue at the two existing wells SC3-E1 and SC3-E2. In
addition, at least one new extraction well, in the vicinity of SC3-7A, will be installed. To
increase the efficiency of groundwater extraction, additional extraction wells may be
necessary in the future. The need for different extraction well locations will be evaluated
at least once every year.
The extracted groundwater will be treated with a granular activated charcoal (GAQ system
to remove VOCs. A GAC system has already been implemented to treat groundwater from
the two existing extraction wells. It consists of two carbon canisters each with 1600 Ibs of
carbon, and a flow capacity of 10 gallons per minute (gpm). They are connected in
parallel, providing 20 gpm total flow capacity. Useful life is about eight months per
canister at present pumping and VOC loading rates. The existing GAC system is effective
in treating the SC3 groundwater, has already been implemented, and is cost effective. The
spent canisters are currently regenerated offsite by Calgon Carbon Corporation.
'/'
The treated groundwater will be discharged to San Tomas Aquino Creek, as is currently
dene, under existing NPDES Permit No. CA0028941. The effluent from the treatment
system has consistently met drinking water levels since discharging began in 1985. The
permit's effluent limit of 5 ppb for Freon 113 has been exceeded on a few occasions since
discharging began in 1985. However, the concentrations of Freon 113 in the effluent on
these occasions was between 7 and 24 ppb, well below the drinking water level of 1200 ppb
for Freon 113. Based on Intel's response on these occasions, immediate actions are
anticipated to be taken by Intel to prevent or correct any violation of their NPDES permit
Board staff believes that the beneficial use of San Tomas Aquino Creek will not be affected
by continuing this discharge.
6.1 Demonstration Project
During the last two years, Intel has often requested that the Regional Board use SC3 as a
demonstration project to determine the fate of low concentrations of VOCs in the
groundwater following an extended period of groundwater extraction and treatment
However, Board staff feels that Intel's proposal to discontinue groundwater extraction
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Staff Report - Page 14
March 30, 1990
Revised June 19, 1990
because Intel contends asymptotic ground water pollutant concentration levels have been
reached is unacceptable until drinking water standards are met or sufficient data exists to
demonstrate that drinking water standards are unattainable.
j
Nonetheless, Board staff has informed Intel that staff would include a task in the RAP
requiring Intel to submit a proposal for a demonstration project The demonstration project
would involve evaluating pulsed pumping from the extraction wells in conjunction with
Alternative 4. Pulsed pumping implies the cycling of extraction wells on and off in active
and resting phases. During the resting or nonpumping phase, groundwater levels will ,
rebound. This will provide greater contact time between the shallow soils and
groundwater, and potentially allow VOCs adsorbed to soil particles to desorb back into the
groundwater. The demonstration project would evaluate various groundwater pumping
strategies for cleaning up residual levels of VOC left behind in aquifer material once
normal groundwater pumping and treating has been shown to be less effective.
Recent literature, as well as practical examples in the South Bay, have shown that removing
the final 10% of groundwater pollution at a site may be more difficult than removing the
initial 90% of groundwater pollution.
Following is an excerpt from a recent EPA technical memorandum promoting pulsed
pumping:
One of the promising innovations in pump-and-treat remediations is pulsed
pumping. Pulsed operation of hydraulic systems is the cycling of extraction or
injection wells on and off in active and resting phases (Figure 5). The resting phase
of a pulsed-pumping operation can allow sufficient time for contaminants to diffuse
out of low permeability zones and into adjacent high permeability zones, until
maximum concentrations are achieved in the higher permeability zones. For sorbed
contaminants and NAPL residuals, sufficient time can be allowed for equilibrium
concentrations to be reached in local groundwater. Subsequent to each resting
phase, the active phase of the cycle removes the minimum volume of contaminated
ground water, at the maximum possible concentrations, for the most efficient
treatment By occasionally cycling only select wells, stagnation zones may be
brought into active flowpaths and remediated.
Pulsed operation of remediation wellfields incurs certain additional costs and
concerns that must be compared with its advantages for site-specific applications.
During the resting phase of pulsed-pumping cycles, peripheral gradient control may
be needed to ensure adequate hydrodynamic control of the plume. In an ideal
situation, peripheral gradient control would be unnecessary. Such might be the case
where there are no active wells, major streams, or other significant hydraulic stresses
nearby to influence the contaminant plume while the remedial action wellfield is in
the resting phase. The plume would migrate only a few feet during the tens to
hundreds of hours that the system was at rest, and that movement would be rapidly
recovered by much higher flow velocities back toward the extraction wells during
the active phase. (Keely, J.F.,1989, Performance Evaluations of Pump and Treat
Remediations, USEPA 540/4-89/005).
. . *
Board staff believes that this rite would be an ideal candidate for such a demonstration
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Staff Report - Page 15
March 30, 1990
Revised June 19, 1990
project for a number of reasons: 1) the plume is relatively small and confined to the A
zone, 2) existing ground water monitoring wells can easily be sampled, and water levels
measured, to determine if any migration has occurred during non-pumping periods, 3) there
are no significant nearby hydraulic stresses (e.g. streams or other extraction system), 4)
current total VOC levels at the SC3 site are in the tens to hundreds of ppb range whereas
most of the other Santa Clara Valley ground water pollutant sites are in die thousands to
tens-of-thousands ppb range.
Potential benefits associated with a demonstration project of pulsed pumping include: 1) a
decrease in the amount of groundwater extracted, 2) provide critical data to evaluate Intel's
hypothesis that asymptotic levels have been or are about to be reached in all wells at the
site, and 3) a reduction of energy consumption associated with operating the extraction
system. This demonstration project will not effect the cleanup standards of the Final
Remedial Plan.
Intel submitted a draft proposal regarding the demonstration project on March 7, 1990.
Ingredients that Board staff have requested in the final proposal include: 1) additional
monitoring of water levels and water chemistry (performance data), 2) running gamma logs
in selected monitoring wells to provide additional stratigraphic control, 3) conducting grain
size sr.:Jysis of aquifer material from the site, and 4) reinfiltration of some or all of the
extracted groundwater particularly if pulsed pumping is shown to significantly lengthen the
cleanup time.
Thus, Board staff recommends that the selected remedy include a task requiring Intel to
submit a proposal to evaluate pulsed pumping as a demonstration project at the site.
6.2 Regional Board Resolution No. 88-160
Intel has considered the feasibility of reclamation, reuse, or discharge to a publicly owned
treatment works (POTW) of treated, extracted groundwater, as specified in Board Resolution
No. 88-160. Reclamation of extracted groundwater at SC3 was tried in 1986. Extracted
groundwater was routed through the facility's wet air scrubber. However, scaling caused
by the high hardness of the groundwater quickly shut down the scrubber. Intel claims the
independent operational requirements of the scrubber and the groundwater extraction
system may only be overcome by installing a complex and expensive system of process
controls and backup systems. The only other substantial use of water at SC3 is landscape
irrigation. However, the total area of landscaping is less than one acre; the present 20,000
gallon per day flow would apply more than 1/2 inch of water per day or 200 inches per
year to the landscaping, far more than it could absorb, especially in the rainy season.
Thus, Intel believes reclamation or reuse of treated, extracted groundwater at SC3 is not
feasible. Since the City of Santa Clara does not allow any discharges of treated
groundwater into its sewer system on a permanent basis, Board staff concurs that treated,
extracted groundwater reclamation, reuse, or discharge to a POTW at SC3 is currently not
feasible.
However, a demonstration project to be conducted at the site may decrease the amount of
treated groundwater discharged to surface waters. Three features of the demonstration
project as described in Section 6.1,, which should decrease the amount of groundwater
discharged are: 1) pulsed pumping allows for the removal of a minimum volume of
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Staff Report - Page 16
March 30, 1990
Revised June 19, 1990
polluted ground water, at the maximum possible concentrations, thus reducing the total
amount of ground water extracted, 2) Intel will be required to evaluate returning extracted
ground water to the source aquifer as part of the demonstration project proposal, and 3)
Intel will be required to evaluate the feasibility of partial reclamation of the extracted
ground water through irrigation as part of the demonstration project proposal
6.3 Cleanup Standards
Geanup standards at the site are set at drinking water standards. Chemicals identified for
cleanup, as well as the risk associated with the cleanup standards, are discussed below.
Since January 1986, TCE has been the only chemical detected above drinking water
standards at SC3. However, because breakdown products of TCE have been detected in the
past, they may appear again in the future. Breakdown products of TCE that have
historically been detected at the site are: 1,1-DCA, 1,1-DCE, cis 1,2-DCE, trans 1,2-DCE, and
1,2-DCA. Vinyl chloride is also a breakdown product of TCE. However, vinyl chloride has
never been detected at SC3. In addition, 1,1,1-TCA and Freon 113, and to much lesser
extent Freon 11, have been detected at the site. 1,1,1-TCA and Freon 113 are currently
detected well below drinking water standards.
Thus, Board staff recommends that Cleanup Standards for the following chemicals be
included in the final RAP: TCE, 1,1-DCA, 1,1-DCE, cis 1,2-DCE, trans 1,2-DCE, 1,2-DCA,
1,1,1-TCA, Freon 113 and Freon 11.
Drinking water standards used to establish cleanup standards for the groundwater at this
site are shown on Table 1. The actual cleanup standards for the site are shown below.
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Staff Report - Page 17
March 30, 1990
Revised June 19,1990
GROUNDWATER CLEANUP STANDARDS FOR INTEL SANTA CLARA 3
Chemical Cleanup Standard1 1989
(ug/1) Maximum
fua/11
POTENTIAL CARCINOGENS
1,1-dichloroethane (1,1-DCA) 5 ND
1,2-dichloroethane (1,2-DCA) 0.5 ND
1,1-dichloroethylene (1,1-DCE) 6 ND
trichloroethylene (TCE) 5 140
NONCARCINOGENS
1,2-dichloroethylene (1,2-DCE)
cis 6 ND
trans 10 ND
1,1,1-trichloroethane (1,1,1-TCA) 200 2.1
Freon 113 1,200 35.0
Freon 11 150 ND
'California State Maximum Contaminant Level (MCL) for
Drinking Water (proposed or adopted).
1989 Maximum Concentration Levels at SC3 (ug/1).
ND - Not Detected (detection levels ranged between 0.5 and
5.0 ppb)
>-'
6.4 Risk Associated with Cleanup Standards
The Carcinogenic Risk and the Hazard Index were described in Section 4.5. Estimations of
the Carcinogenic Risk and Hazard Index associated with the above cleanup standards for
the site are shown on Table 3. Appendix 8 contains the assumptions used in the
estimation.
Potential carcinogens historically detected at SC3 are 1,1-DCA, 1,2-DCA, 1,1-DCE, and TCE
All four of these chemicals have been assigned cleanup standards for the site. Board staff
have made the risk management decision of not including 1,1-DCE in the risk calculation
for the cleanup standards.
The decision to not include 1,1-DCE in the risk calculation is based on the following
factors: 1) 1,1-DCE has only been detected at SC3 above its MCL (of 6 ppb) on five
occasions out of over 450 separate analyses, 2) during the last two years 1,1-DCE has never
been detected in any of the monitoring and extraction wells above detection Emits
(detection limits have ranged from 0.1 to 5.0 ppb), and 3) due to 1,1-DCE's high inhalation
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Staff Report - Page 18
March 30, 1990
Revised June 19, 1990
cancer potency factor, if 1,1-DCE were to be included in the risk calculation, it would
literally drive the cleanup standards downward unnecessarily below MCLs.
The Carcinogenic Risk associated with the cleanup standards for 1,1-DCA, 1,2-DCA, and
TCE is 1.3x10*, and falls within EPA's acceptable Carcinogenic Risk range of one-in-a-
million (10*) to one-in-ten-thousand (10*4) individual lifetime excess cancers that may develop
in a population.
The Regional Board and EPA consider that for a remedial action of a drinking water source
to be protective, it should have a Carcinogenic Risk of 1x10* as the point of departure for
setting remedial standards, and a least protective endpoint of IxlO4. A departure from the
Carcinogenic Risk of 1x10* to 1.3x10* is necessary at SC3 because the cleanup standards that
would be necessary to meet a Carcinogenic Risk of 1x10* are unlikely to be technically
achievable.
Nonetheless, Board staff regards the Carcinogenic Risk associated with the cleanup
standards as extremely conservative. In cleaning up TCE to the 5 ppb cleanup standard, it
is quite likely that concentration of other VOCs will be reduced to levels below detection
limits. The Carcinogenic Risk associated with the 5 ppb cleanup standard for TCE alone is
1.5x10*- Board staff therefore concludes that a departure from the 1.0x10* is protective of
human health.
Toxic non-carcinogens detected at SC3 are 1,1-DCA, cis 1,2-DCE, trans 1,2-DCE, Freon 113,
Freon 11, and 1,1,1 TCA. The Hazard Index associated with the cleanup standards for these
chemicals is 0.1 Board staff conclude that since the Hazard Index is less than one, the
combined intake of chemicals is unlikely to pose a health risk.
7.0 AREAS OF DISAGREEMENT
Currently there are three areas of disagreement at the site. Board staff recommends that
these issues be resolved in the RAP as well as in an agency addendum to the RI/FS, rather
than in another revised version of the RI/FS. A discussion of these areas of disagreement
follows:
7.1 Applicability of drinking water ARARs to the SC3 site.
Intel's Position: Intel states in the RI/FS that, "While the A-aquifer potentially
satisfies EPA and RWQCB criteria as a potential drinking water supply, the Santa
Clara Valley Water District (SCVWD), which is the controlling agency, does not
allow the use of the A-aquifer as a water supply source (Ordinance 85-01). The A
zone can only be used for monitoring wells . Since the shallow ground water (A
zone) will not be used for drinking, drinking water standards are not applicable as
remediation goals".
Regional Board staffs Position: The SCVWD's Ordinance 85-1 requires a minimum
50 feet sanitary seal in all drinking water wells. Tom Iwamura, of the SCVWD, has
informed Board staff that this requirement is intended to protect the public from
biological pollution which may be present in the shallow aquifers from pollution
sources such as septic tanks at a time when use of the shallow aquifer as drinking
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Staff Report - Page 19
March 30, 1990
Revised June 19,1990
water supply is not yet necessary. The Ordinance is not intended to allow the
degradation of the shallow groundwater zones.
The regulatory frame work associated with the cleanup of groundwater at the site is
driven by the beneficial (current or potential) use of local groundwater. As stated in
40 CFR 300.430(a)(ii)(F), "The goal of EPA's Superfund approach is to return usable
ground waters to their beneficial uses wherever practicable within a timeframe that
is reasonable given the particular circumstances of the site". Drinking water is
considered to be the highest beneficial use and affords the greatest level of
protection and cleanup.
The Regional Board's Basin Plan classifies the shallow ground water in the area of
SC3 as "potentially suitable for municipal or domestic water supply". EPA has
consistently upheld this policy in the South Bay. Therefore, drinking water
standards are applicable as remediation goals for the A-aquifer zone.
Additionally, this Regional Board has incorporated the SWRCB Policy of "Sources of
Drinking Water" into the Basin Plan. The policy provides for a Municipal and
Domestic Supply designation for all waters of the State with some exceptions. As
described in Section 4.1., based on data submitted by Intel, these two exceptions do
not apply to the A zone at SC3.
Recommendation: Based on the above discussion, the A zone at SC3 is, in fact, a
potential source of drinking water. Therefore, cleanup standards contained in the
RAP must be based on drinking water standards.
7.2 The Selected Remedy.
Intel's Position: Intel's recommended remedy consists of a deed restriction,
groundwater monitoring, and keeping the existing extraction system in stand-by
mode with some pulsed pumping.
~s'
Regional Board staff's Position: Intel's selected remedy is predicated on the
assumption that drinking water standards do not apply to the A zone. As discussed
in Section 7.1, Board staff disagrees with this assumption. As such, Alternative 3
would not necessarily attain cleanup standards. In addition, based on conclusions in
the FS that Alternative 4 could potentially achieve long-term effectiveness and
permanence and reduction of toxicity, mobility and/or volume of VOCs in the
shortest time, Board staff believes that Alternative 4 is a more appropriate remedy
than Alternative 3 for the site. Alternative 4 consists of a deed restriction, continued
ground water monitoring, pumping from existing extraction wells and one additional
well, and treatment with an expanded granular activated carbon system.
Recommendation^ The proposed plan must be modified to include Alternative 4 in
the selected remedy. As discussed in Section 6.1, Board staff also recommends that
the selected remedy include a task requiring Intel to submit a proposal to evaluate
pulsed pumping as a demonstration project at the site.
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Staff Report - Page 20
March 30, 1990
Revised June 19, 1990
7.3 Asymptotic Levels
InteKs Position: Throughout the Rl/FS, reference is made to the daim that the
concentrations of most VOCs in the wells are at or approaching asymptotic levels.
While the concentrations of most VOC's in most wells have decreased since the
initiation of extraction, Intel contends that little additional decrease is likely.
Regional Board's Position: Based on information submitted by Intel, asymptotic
levels are predicted in the RI/FS for the following wells:
100 ppb TOE for well SC3-E2,
30 ppb TCE for well SC3-1,
15 ppb TCE for well SC3-E1,
5 ppb TCE for well SC3-3,
The Regional Board's Technical Assistance contractor, Camp Dresser, McKee (CDM),
evaluated Intel's hypothesis of asymptotic levels in a report dated October 5, 1989.
CDM's report states that with the exception of well SC3-3, these values are
considerably higher than the asymptotic values observed at a nearby site.
Asymptotic values of 2 to 6 ppb were observed at the Stanford/Moffett NAS Field
Site (Semprini, L, P.V. Roberts, G.D. Hopkins, and D.M MacKay, 1987, A Field
Evaluation of In-Situ Biodegradation Methodologies for the Restoration of Aquifers
Contaminated with Chlorinated Aliphatic Compounds, Stanford Tech. Report No.
302).
On the other hand, Board staff recognize that the two sites also have significant
differences. Major differences between the Stanford/Moffett NAS Field Site (NAS)
and the SC3 site are 1) the aquifer material at the NAS site is more coarse grained,
2) the initial concentration of the TCE was lower at the NAS site, and 3) the time
between the TCE release and cleanup was shorter at the NAS site.
However, as shown on Figures 6 and 7, asymptotic levels do not appear to have
been conclusively reached in all wells at SC3. With the installation of an additional
extraction well and pulsed pumping, TCE levels are likely to decrease.
Recommendation: Additional extraction wells need to be installed to evaluate
whether or not asymptotic levels truly have been reached. The RAP includes tasks
which require Intel to: 1) continue ground water extraction until drinking water
quality is achieved, if feasible, or, as long as significant quantities of chemicals are
being removed, 2) install additional extraction well(s), and 3) modify the existing
extraction well lay-out if reductions in removal efficiencies continue.
Furthermore, the demonstration project to evaluate pulsed pumping, described in
Section 6.1, may produce additional reductions of pollutant concentrations in the
groundwater.
If drinking water quality cannot be achieved at SC3, Intel would need, to
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
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Staff Report - Page 21
March 30, 1990
Revised June 19, 1990
engineering perspective) and that the alternative proposed will be protective of
human health and the environment The RAP would then need to be modified by
the Regional Board and approved by EPA to allow a less stringent groundwater
cleanup level
8.0 CONCLUSION
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 MCLs and
falls within EPA's acceptable Carcinogenic Risk range of 10"* to 10*. In addition, the
remedy at least attains the requirements of all ARARs, including Federal and State MCLs
and State Drinking Water Action Levels.
Furthermore, the technologies forming the selected remedy - pumping, and treating with
GAC - are cost effective technologies. The selected remedy will permanently and
significantly reduce the toxicity, mobility, and volume of hazardous substances with respect
to their presence in groundwater.
Pollution is controlled and removed from the groundwater, thereby reducing the potential
threat to the nearby public water supply wells and also restoring the aquifers to meet
drinking water standards.
9.0 RECOMMENDATION
Staff recommends that the Board adopt the remedial action plan contained in the Tentative
Order. The Tentative Order approves the Rl/FS submitted February 18, 1990 as modified by
the Addendum, this staff report, and the Tentative Order.
Concur with revision:
Bruce R Wolfe, Section Leader
Concur with revision:
Stephen I. Morse, Division Chief
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Staff Report - Page 22
March 30, 1990
Revised June 19, 1990
Attachments:
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Table 1
Table 2
Table 3
Appendix A:
Appendix B:
Appendix C:
Appendix D:
Site Location Map - Intel Santa Clara 3.
Site Map of Intel Santa Clara 3 (showing distribution of TCE in the A
Water-Bearing Zone, August 16,1989).
Representative Log for Intel Santa Clara 3 (Boring Log for Monitoring Well
SC3-5B).
Potentiometric Surface of the A Water-Bearing Zone Without Pumping, 8
June, 1988 Intel Santa Clara 3.
Potentiometric Surface of the A Water-Bearing Zone with pumping - Intel
Santa Clara 3 - August 16, 1989.
Concentration of TCE vs. Time in Monitoring Well SC3-1 and Extraction
Wells SC3-E1 and El
Concentration of TCE vs. Time in Monitoring Well SC3-7A.
Idealized effect of pulse pumping over time.
Federal and State drinking water standards.
Remedial Technology Screening: Groundwater, Intel SC3, Feasibility Study.
The Cancer Risk and Hazard Index Associated With the Groundwater
Geanup Standards,
Index To the Administrative Record (available upon request).
Assumptions Used To Calculate Hazard Index and Carcinogenic Risk.
Agency Addendum for the RI/FS Report
Responsiveness Summary
-------
4000fT
SANTA CLARA 3
Figure 1. Site Location Map - Intel Santa Clara 3
-------
CENTRAL
ISSWAY
0.859 TCE concentration (ppm)
TCE concentration contoi
(ppm). dashed where Interred
t\ (V\0 TCE concen'r«"on contour.
8C3-5B SC3-5A
ll/TEL SANTA CLARA 3
/ BUILDING
INTEL SANTA CLARA 4
BUILDING
Figure 2. Site Map of Intel Santa Clara 3 (showing distribution of TCE in the A Water-
Bear ing Zone, August 16, 1989)
-------
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Figure 3. Representative Log for Intel Santa Clara 3 (Boring Log for Monitoring Well
SC3-5B)
-------
CENTRAL E> £SSWAY
EXPLANATION
,. Polenllometric surlace elevation.
* .?» leel above mean sea level
Potentiometric surface elevation
contour, leet above mean sea level.
INTEL SANTA CLARA 4
BUILDING
Figure 4. Potentiometric Surface of the A Water-Bearing Zone Without Pumping, June 8,
1988 - Intel Santa Clara 3
-------
CENTRAL EXPRESSWAY
N
MAS Potentiometric Burfaea elevation.
zo.ua |Mt tbove mean tea level
Potentiometric surface elevation
contour. !! abov* moan toa tovol.
dashod wtioro Interred
INTEL SANTA CLARA 4
BUILDING
Figure 5. Potentiometric Surface of the A Hater-Bearing Zone with Pumping - Intel Santa
Clara 3 - August 16, 1989
-------
Intel Santa Clara 3
AVG. TCE CONCENTRATION IN SC3-1
1982- 1989
500
400
Intel Santa Clara 3
AVG. TCE CONCENTRATION IN SC3-E1 & E2
1985-1989
IMS
1907 . 1906
DATE (YEAR)
1909
Figure 6 Concentration of TCE vs. Tine in Monitoring Weil SC3-
1 and Extraction Wells SC3-E1 and E2.
-------
u
u
280-
240-
200-
16O-
120
80
4O
O ' i I I i " i '. I" 1 '" i
00 CO
o
o5
oo
00 00 00 00 00 00 00
o
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00 O
DATE
Figure 7. Concentration of TCE vs. Tine Detected in Monitoring Well SC3-7A
-------
OFF
WAX
.TIME
Figure 8. Idealized effect of pulsed pumping over tine. (From:
Keely, J.F., 1989, Performance Evaluations o*f Pump
and Treat Remediations USEPA 540/4-89/005)
-------
TABLE 1
STATE AND FEDERAL DRINKING WATER STANDARDS
INTEL SANTA CLARA 3
Chemical
1,l-dtcMoroethane(1,1-DCA)
1 ,2-dicnioroetane ( 1 ,2-DCA)
1 .J-clichloroethene ( 1 ,1-DCE)
cis 1,2-dlchloroethene(cls 1.2-DCE)
trans 1 ,2-dichloroethene ( trans 1 ,2-DCE)
Freon- 1 1
Freon- 113
1,1,l-trlch1oroethane(1,1,1-TCA)
trichloroethene(TCE)
Federal
Maximum Contaminant
Levels (Mas)
(ua/L)
.
-
7.0
.
CA State
Mas
(ua/L)
proposed: 5.0
proposed: 0.5
6.0
proposed: 6.0
proposed; 10,0
proposed: 150.0
roposed: 1200.0
200.0
5.0
CA State
Drinking Water
Action Levels
(ua/L)
5.0
1.0
-
6.0
10.0
150.0
1200.0
-
-
'-" Implies no criteria
-------
Ground Water
Central
Response Action
o Action
Institutional
Actions
Access
Restrictions
r-pin.
Cn-Slte
teacdlel
Technology
Hans
*
legal Controls
Monitoring
Physical
Control
Extraction
. - .
lotoglcal
Process
Option
at Applicable
Deed Restrictions
Crowd Mater
enltorlng
.Fences- '
RQCOWry Wills
Subeurfac* Drains
Aerobic
Description
o Action
Deed andlf (cations to restrict development/
resource use at SC3
On-going ground Mater quality and level
onltorfng. May incorporate use of existing
Malls
PerlMter fence around SCS treatment syste*
to restrict access
Installation of Mils for extraction of
grouid uater ,
Installation of a collection trench for
recovery of ground Meter
Degradation of organic* using artcro- organise*
Screening Caamnts
tqulred by K» to establish baseline for coaparlson
purposes
potentially applicable
Potentially applicable
Hot needed based on PHE.
Potentially applicable
Hot applicable; geologic condition
Instead of drains
Rot applicable; has not been show
t favor Mil la
to be technically
Physical
Air Stripping
In on oxygenated onvlronsant
Mass transfer of volatile) constituents fro*
Mater to olr
Carbon Adsorption «e*oval of constituents fro* MBter by
adsorption onto carbon
Stee* Stripping Separation of volatile
wits fro* a liquid
future via direct contact of the Mixture Mlth
steeai and separate recovery of the vapors f raa
the residue.
Is Separation of solutes froa a solvent via
application of a pressure gradient across a
te*l-ptra*able aaatarane
achievable for the VOCs at the alto, especially at
these very low concentrations.
potentially applicable for rawing the VOCs detected
at the site
Potent tally applicable for rowing the VOCs
detected at the site. Currently In use and effective.
potentially applicable for rowing the VOCs detected
at the alto.
lot applicable; very Merited for organic constituents
Table 2. Remedial Technology Screening: Groundvater, Intel Santa Clara 3 Feasibility Study
-------
Ground Water
General
Response Action
emdlol
Technology
Process
Option
Description
Screening Caexwnts
On-Slte TreetsMnt Physical Distillation
(continued) Treetxcnt
(continued)
liquid/liquid
Extractten
Cootxnents of a liquid Mixture are separated by
partially vaporizing the Blxture through tba
indirect addition of heat and separately
recovering the vapors fro* the residue.
The separation of components in liquid
Uture by contacting the Mixture tilth
liquid solvent that has a selective affinity for
of the coaponenta
Filtration
Separation of dissolved solids fro* Mater by
forced vaporization of the Mter through the
Indirect addition of heat
Physical separation of suspended particle* fro»
a liquid via f Ion across a porous aadlua
Potentially applicable
lot applicable based on the Halted availability of
envlronxentatly acceptable solvents.
ot applicable for solutes ulth volatilities greater
than or equal to that of the solvent, such aa
constituents detected In ground Meter beneath SO.
ot applicable for organic*
Oiasrieat
Tr
Precipitation. Chealcal reaction which decreases a constituent** Rot applicable far tha organic* detected at tha alt*
Mocculatlon and aolubillty generating a precipitate that gravity
Sodlxentation \ aettlee. .
eutrallntlan Chealcal adjuatswrt of p*
In-Sltu
Tr
Oxidation/
teductlori
Dec*tor(nation
loractaeBtlon
A chesilcal reaction lAlch transfers electrons
froai compounds Mhleh subsequently altars tha
characteristics of those
echlorlnatton la tha addition of an oxldant to
chemically cleave chlorine aaleories froai aojueoua
contasilnanta.
injection of nutrients and/or lcro*organlsa»
In aubsurface to enhance biological degradation
ot applleablt; has no effect an VOCa.
Potentially applicable
ot feaalMa for the destruction of
chlorinated organlcs detected at the sltt
Technology not sufficiently developed to produce
predictable nan-toxic products within tlea fraaes
of ether applicable technologies
Table 2. - continued -
-------
Ground Vat*
Central toedUl Proton
ftotporao Action Technology Option
Description
Screening CoMentt
ItCfcOrflO
On-Slto
OlscharflO
Off'tlto
Dlochora*
tnjoetlon MtU lolnjtct tmtod trowd Mtor Into tho
sono
turfoM VMtr
NtW
OlMhoro* trwtotf flroifid Mtor t» poralttotf
WOCS outfall
Olocharojo to nlelpal Mnltary
Potentially opplleoblo
etcntlotly oppllcobto; currontly In wo
Noy not bo fooolMo basod on roportod coauilcotlt
MI tk rani
Table 2. continued
-------
TABLE 3
INTEL SANTA CLARA 3
DETERMINATION OF EXCESS LIFETIME
CARCINOGENS RISK BASED ON CLEAN UP STANDARD
CW = Clean Up Standard
CPF » Cancer Potency factor (mg/kg/day)-1
CDI = Chronic Daily Intake (mg/kg/day) = Cw x 0.011
Risk = CDI x CPF
Chemical Cw CDI CPF (ORAL) ORAL RISK CPF (INHAL) INHAL RiSK RSIK (ORAL + INHAL)
1,1-DCA
! ,2-DCA
TCE
0.005
0.0005
0.005
5.50E-05
5.50E-06
5.50E-05
0.091
0.091
0.011
5.01E-06
5.0IE-07
6.05E-07
* 0.091
* 0.091
0.017
5.01E-06
5.0IE-07
9.35E-07
1.00E-05
I.OOE-06
1.54E-06
Total Carcinogens Risk = 1.26E-05
* Oral CPF,' no Inhal CPF available.
-------
TABLE 3 (Continued)
INTEL SANTA CLARA 3
DETERMINATION OF TOTAL HAZARD INDEX
FOR NON-CARCINOGENS BASED ON CLEANUP STANDARD
Cw = Clean Up Standard
RfD = Reference Dose (mg/kg/day)
CDI = Chronic Dally Intake (mg/kg/day)
HI = Hazard Index = CDI/RfD
Cw x 0.029
CHEMICAL
Cw
CDI
RfD(ORAL) ORAL HI RfD(INHAL) INHAL HI
HKORAL + INHAL)
1,1-DCA
clst,2-DCE
trans 1,2-DCE
FREON 1 1
FREON 113
1,1,1-TCA
0.005
0.006
0.010
0.150
1.200
0.200
1.45E-04
1.74E-04
2.90E-04
4.35E-03
3.48E-02
5.80E-03
1.00E-OI
M.OOE-02
2.00E-02
3.00E-01
3.00E+01
8.60E-02
1.45E-03
1.74E-02
1.45E-02
1.45E-02
1.16E-03
6.74E-02
0.100
N/A
N/A
0.200
N/A
0.300
1.5E-03
N/A
N/A
0.022
N/A
0.019
2.90E-03
1.74E-02
1.45E-02
3.63E-02
1.16E-03
8.68E-02
Total Hazard Index
1.59E-01
Note: Assumptions used to estimate CDI are presented In Appendix B.
CPF. and Rfd from EPA's Integrated Risk Information System (IRIS).
N/A - Inhalation RfD not available
-------
APPENDIX B
ASSUMPTIONS USED TO CALCULATE HAZARD INDEX AND CARCINOGENIC RISK
ASSOCIATED WITH CLEANUP STANDARDS
Introduction .
Assumptions and methods used to calculate the Hazard Index and Carcinogenic Risk
associated with the cleanup standards are explained in this Appendix. These assumptions
and methods are based on EPA guidance documents and generic aspects of Public Health
Evaluations prepared by the Regional Board's contractor, ICF dement
Background
The ideal goal of groundwater cleanup is to restore the aquifer to its original pristine
condition. However, it is technically impossible to remove every molecule of the chemical
from the aquifer. Cleanup standards are therefore established with the knowledge that
some residual chemical levels will remain in the aquifer, even after long term cleanup.
Chemicals in the groundwater are divided into: 1) known, possible, or probable cancer
causing substances (carcinogens), and 2) toxins (noncarcinogens). The health risk associated
with the cleanup standards for carcinogens is called the Carcinogenic Risk The risk
associated with cleanup standards for noncarcinogens is quantified using the Hazard Index.
Routes of Exposure
The probable route of exposure to the groundwater affected by SC3 would be by means of:
1) drinking the groundwater, and 2) inhalation of VOCs while showering. According to
EPA Region IX guidance documents, the exposure due to inhalation while showering is
considered to be equal to the exposure associated with the drinking water scenario.
>'
Estimation of Chronic Daily Intake
To estimate the Carcinogenic Risk and Hazard Index associated with the cleanup standards,
an estimation must first be made of the amount of chemicals that may be ingested if
groundwater affected by SC3 were used as drinking water. The amount of the chemicals
ingested is known as the chronic daily intake (CDI).
The estimated intakes of contaminants from ingestion of groundwater were calculated using
the following equation:
-------
Appendix B - Page 2
March 30, 1990
rev. June 19, 1990
ITK, =
where,
ITK, =
Cw =
W
G =
D
and
GDI =
where,
GDI =
ITK, =
D
F
BW
E
365 =
(Cw) x (W) x (G) x
chemical intake from groundwater (mg/day),
cleanup goal (mg/liter),
daily water consumption (liters/day),
drinking water ingestion absorption factor, and
dietary fraction of water ingested at home.
[(ITK, )(D)(F)J/l(BW)(E)(365)]
average chronic daily intake via groundwater (mg/kg/day),
daily chemical intake via groundwater (mg/day),
duration of exposure (years),
frequency of exposure (days/year),
body weight (kg),
extrapolation factor (years):
for noncarrinogens - 30 year period;
for carcinogens 75 year lifetime, and
conversion factor (days/year).
For all groundwater exposure scenarios, it was assumed that residents ingest groundwater
on a daily basis for 30 years under plausible maximum conditions. The exposure period
used in this scenario corresponds to the 90th percentile for length of residence in a U.S.
house. Residents are assumed to consume 2 liters of water per day under maximum
plausible conditions. Residents are assumed to obtain 100% of their drinking water at
home. Subsequent absorption of the chemicals from the ground water into the gut is
assumed to be 100%. .
PARAMETER
ASSUMPTIONS FOR USE IN RISK ASSESSMENT FOR
GROUNDWATER CLEANUP STANDARDS
PLAUSIBLE MAXIMUM
EXPOSURE
Quantity of Water Ingested (W)
Diet Fraction P)
Absorption from Water (G)
Frequency of Exposure (F)
Duration of Exposure
Body Weight (BW)
Average lifetime
2 liter/day
1.0
100 percent
365 days/year
30 years
70kg
75 years
-------
Appendix B - Page 3
March 30, 1990
rev. June 19, 1990
Calculation of Carcinogenic Risk Based on Cleanup Standards
Carcinogenic Risk is defined as the product of the chronic daily intake (GDI) multiplied by
the cancer potency factor (CPF). The GDI is estimated using the above assumptions. The
G?F for both the oral and inhalation exposure routes are obtained from EPA's Integrated
Risk Information System (IRIS).
In general, CPF's based on animal data represent the 95-percent upper-confidence limit
values based on a linearized-multistage model Thus, the actual risks associated with
exposure to a potential carcinogen quantitatively evaluated based on animal data are not
likely to exceed the risks estimated using these cancer potency factors. However, they may
be lower.
The Regional Board and EPA consider that for a remedial action of a drinking water source
to be protective, it should have a Carcinogenic Risk that falls within a range of one-in-a-
million (10*) to one-in-ten-thousand (104) individual lifetime excess cancers that may develop
in a population.
An estimation* of the Carcinogenic Risk associated with the cleanup standards presented in
Section 6.3 is shown on Table 3. Potential carcinogens detected at SC3 are 1,1 DCA, 1,2-
DCA, 1,1-DCE, and TCE. As discussed in Section 6.4, 1,1-DCE was not included in this
calculation. The Carcinogenic Risk associated with the cleanup standards for 1,1 DCA, 1,2-
DCA, and TCE is 1.3x10*
Calculation of the Hazard Index Based on Cleanup Standards
Potential risks are assessed for noncartinogens by taking the ratio of the chronic daily
intake (CDI) to the reference dose (RfD). The GDI is estimated using the above
assumptions. The RfD for both the oral and inhalation exposure routes are obtained from
EPA's Integrated Risk Information System QR1S).
Toxic effects of noncarcinogenic chemicals are initially assumed to be additive, in
accordance with EPA guidance on health risk assessment of complex mixtures. For each
scenario, the CDI:RfD ratios for each individual chemical are summed to produce a Hazard
Index for total toxic risks. If the Hazard Index is less than one, the combined intake of
chemicals by the exposure route under consideration is unlikely to pose a health risk
An estimation of the Hazard Index associated with the cleanup standards presented in
Section 6.3 is shown on Table 3, Toxic non-carcinogens detected at SC3 are 1,1-DCA, as
1,2-DCE, trans 1,2-DCE, Freon 113, Freon 11, and 1,1,1 TCA. The Hazard Index associated
with the cleanup standards for these chemicals is 0.2.
Thus, Board staff concludes that the Cleanup Standards for the site are protective of human
health, have a Carcinogenic Risk that falls within a range of 10* to 104, and a Hazard
Index of less than one.
-------
APPENDIX C
ATTACHMENT TO THE STAFF REPORT
AGENCY ADDENDUM FOR
REMEDIAL INVESTIGATION / FEASIBILITY STUDY
INTEL SANTA CLARA 3 FACILITY
Intel submitted a revised Remedial Investigation / Feasibility Study, dated February 16, 1990.
The report contains the results of the subsurface investigation, a description of the
groundwater pollution, and an evaluation of the interim cleanup actions, remedial
alternatives, and groundwater conservation measures. Regional Board staff have determined
that the technical information contained in the RI/FS is acceptable for developing a final
cleanup plan; however; Regional Board and other agency staff do not accept all
interpretations and recommendations contained in the RI/FS.
In making this determination, staff disagreed with the portions of the RI/FS addressing: 1)
Applicable or Relevant and Appropriate Requirements, 2) Asymptotic Levels, and 3) The
Selected Remedy. As part of the Regional Board's comments on the September, 1989 draft
RI/FS, Intel was informed of these three areas of disagreement In revising the RI/FS, Intel
did not address these three areas.
Board staff, therefore, recommends that these issues be resolved in this agency addendum
to the RI/FS and in the RAP, rather than in another revised version of the Remedial
Investigation / Feasibility Study (RI/FS).
I. APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS.
Geanup at a Superfund site must comply with legally applicable or relevant and
appropriate requirements (ARARs). Regional Board, EPA, and Santa Clara Valley
Water District (SCVYVD) staff disagree with several of Intel's conclusions regarding
ARARs. ARARs for the site consist of the ARARs identified on pages 110-112 of
Intel's RI/FS with the following modifications.
A. Groundwater as a potential Source of Drinking Water. The RI/FS states that
"While the A-aquifer potentially satisfies EPA and RWQCB criteria as a
potential drinking water supply, the SCVWD, which is the controlling agency,
does not allow the use of the A-aquifer as a water supply source (Ordinance
85-01). The A zone can only be used for monitoring weUs . Since the
shallow ground water (A zone) will not be used for drinking, drinking water
standards are not applicable as remediation goals".
The SCVWD's Ordinance 85-1 requires a minimum 50 feet sanitary seal in all
drinking water wells. However, this requirement is primarily intended to
protect the public from biological pollution which may be present in the
shallow aquifers from pollution sources such as septic tanks at a time when
-------
Agency Addendum-Page 2
March 30, 1990
rev. June 19,1990
use of the shallow aquifer as drinking water supply is not yet necessary!
The Ordinance is not intended to allow the degradation of the shallow
ground water zones.
The regulatory frame work associated with the cleanup of groundwater at the
site is driven by the beneficial (current or potential) use of local groundwater.
The description of the revision to 40 CFR 300, contained on page 51433 of the
Federal Register stated, "the goal of EPA's Superfund approach is to return
usable groundwaters to their beneficial uses within a timeframe that is
reasonable". Drinking water is considered to be the highest beneficial use
and affords the greatest level of protection and cleanup. The Regional
Board's Basin Plan as amended is an ARAR and classifies the shallow ground
water in the area of SC3 as "potentially suitable for municipal or domestic
water supply".
Thus, drinking water standards, and the Regional Board's Basin Plan as
amended are ARAR&
B. State Board Resolution 68-16. Intel's opinion is that State Board Resolution
68-16 is not an ARAR because it has not been consistently applied. The
Regional Board's position is that State Board Resolutions are legally
enforceable ARARs.
D. ASYMPTOTIC LEVELS
Throughout the RI/FS, reference is made to the claim that the concentrations of most
VOCs in most wells are at or approaching asymptotic levels. While the
concentrations of most VOC's in most wells have decreased since the initiation of
extraction, Intel contends that little additional decrease is likely.
Based on information submitted by Intel, asymptotic levels are predicted in the RI/FS
for the following wells:
100 ppb TCE for well SC3-E2,
30 ppb TCE for well SC3-1,
15 ppb TCE for well SC3-E1,
5 ppb TCE for well SC3-3.
With the exception of well SC3-3, these values are considerably higher than the
asymptotic values observed at a nearby site with similar geology. Asymptotic values
of 2 to 6 ppb were observed at the Stanford/Moffett NAS Field Site (Semprini, L,
P.V. Roberts, G.D. Hopkins, and D.M, MacKay, 1987, A Field Evaluation of In-Situ
Biodegradation Methodologies for the Restoration of Aquifers Contaminated with
Chlorinated Aliphatic Compounds, Stanford Tech. Report No. 302). Based on the
this field test, Board staff concludes that asymptotic levels for TCE have not yet been
reached at SC3. Furthermore, as shown on Figures 6 and 7 of the March 30, 1990
staff report (revised June 19, 1990), asymptotic levels do not appear to have been
conclusively reached in all wells at SC3. With the installation of an additional
-------
Agency Addendum-Page 3
March 30, 1990
rev. June 19, 1990
extraction well and pulsed pumping, TCE levels are likely to decrease.
Additional extraction wells need to be installed to evaluate whether or not
asymptotic levels truly have been reached. The RAP includes tasks which require
Intel to: 1) continue groundwater extraction until drinking water quality is achieved,
if feasible, or, as long as significant quantities of chemicals are being removed, 2)
install additional extraction well(s), and 3) modify the existing extraction well lay-out
if reductions in removal efficiencies continue.
Moreover, the demonstration project to evaluate pulsed pumping, described in
Section 6.1 of the March 30, 1990 staff report (revised June 19, 1990), may produce
additional reductions of pollutant concentrations in the groundwater.
If drinking water quality cannot be achieved at SC3, Intel would need to
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 RAP would then need to be modified by
the Regional Board and approved by EPA to allow a less stringent groundwater
cleanup level
HI. THE SELECTED REMEDY
Intel's recommended remedy is Alternative 3 and consists of a deed restriction,
groundwater monitoring, and keeping the existing extraction system in stand-by
mode with some pulsed pumping.
Intel's selected remedy is predicated on the assumption that drinking water standards
do not apply to the A zone. As discussed in Section I.A., the agency staff disagrees
with this assumption. As such, Alternative 3 would not necessarily attain cleanup
goals. In addition, based on conclusions in the FS that Alternative 4 could
potentially achieve long-term effectiveness and permanence and reduction of toxicity,
mobility and/or volume of VOCs in the shortest time, agency staff believes that
Alternative 4 is a more appropriate remedy than Alternative 3 for the site.
Alternative 4 consists of the following elements: a deed restriction, continued ground
water monitoring, pumping from existing extraction wells and at least one additional
well, and treatment with an expanded granular activated carbon system.
The proposed plan is hereby modified to substitute Alternative 4 as the selected
remedy. Alternative 4 is further modified to require Intel to submit a proposal for a
demonstration project The demonstration project involves pulsed pumping from the
extraction wells in conjunction with Alternative 4. Pulsed pumping implies the
cycling of extraction wells on and off in active and resting phases.
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
1235 Mission Street
San Francisco, CA 94103
SELF-MONITORING PROGRAM FOR INTEL SANTA CLARA 3.
General 1
'Sampling and Analytical Methods 1
Reports to be Filed with the Regional
Board 1
Bypass Reports 1
Self-Monitoring Reports 2
Description of Groundwater Sampling
Locations 5
Schedule and Conditions of Sampling
and Analysis 5
Attachments
Table 1 list of wells identified for
the self monitoring program.
Table 2 - Final Cleanup Standards
Table 3 - Monitoring Frequency
Figure 1 - Facility map including
well locations
-------
CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD
SAN FRANCISCO BAY REGION
INTEL CORPORATION
INTEL SANTA CLARA 3 FACILITY
2800 NORTHWESTERN PARKWAY
SANTA CLARA, SANTA CLARA COUNTY
GROUNDWATER SELF-MONITORING PROGRAM
A. GENERAL
Reporting responsibilities of waste dischargers are specified
in Sections 13225(a), 13267(b), 13268, 13383, and 13387(b) of
the California Water Code and this Regional Board's Resolution
No. 73-16.
The principal purposes of a waste discharger's monitoring
program, also referred to as a self-monitoring program, are:
(1) To document compliance with site cleanup requirements and
prohibitions established by this Regional Board, (2) To
facilitate self-policing by the waste discharger in the
prevention and abatement of pollution arising from waste
discharge, (3) To develop or assist in the development of
effluent or other limitations, discharger prohibitions,
national standards of performance, pretreatment and toxicity
standards, and other standards, and (4) To prepare water and
wastewater quality inventories.
B. SAMPLING AND ANALYTICAL METHODS
Sample collection, storage, and analyses shall be performed
according to the EPA Method 8000 series described in "Test
Methods for Evaluating Solid Wastes, Physical/Chemical
Methods," dated November 1986; or other methods approved and
specified by the Executive Officer of this Regional Board.
C. REPORTS TO BE FILED WITH THE REGIONAL BOARD
1. Violations or Potential Violations of Requirements
a. The discharger shall file a written technical report
at least 15 days prior to advertising for bid on any
construction project which may potentially adversely
effect the dischargers' soil and groundwater cleanup
activities. All projects involving subsurface
construction shall be reported.
b. In the event the discharger is unable to comply with
the conditions of the site cleanup requirements and
prohibitions due to:
-------
Self Monitoring Plan
Intel Santa Clara 3
Page 2
(1) maintenance work, power failures, or breakdown
of waste treatment equipment, or
(2) accidents caused by human error or negligence,
or
(3) other causes such as acts of nature, or
(4) poor operation or inadequate system design,
the waste discharger shall promptly accelerate the
pertinent portions of the monitoring program to
weekly or as required by the Regional Board's
Executive Officer for those constituents which have
been violated. Such analysis shall continue until
such time as the discharger is back in compliance
with the conditions and prohibitions of the site
cleanup requirements, or until such time as the
Executive Officer determines to be appropriate. The
results of such monitoring shall be included in the
regular Self-Monitoring Report.
2. Bypass Reports
Bypass reporting shall be an integral part of the regular
monitoring program report. A report on bypassing of
treatment units shall be made which will include cause,
time and date, duration and estimated volume bypassed,
method used in estimating volume, and persons and
agencies notified. Notification to the Regional Board
shall be made immediately by telephone (415-464-1255),
followed by a written account within 15 days.
3. Self-Monitorina Reports
a. Reporting Period:
Written reports shall be filed regularly each
quarter within thirty days from the end of the
quarter monitored. The first quarterly report is
due July 31, 1990.
b. Letter of Transmittal:
A letter transmitting self-monitoring reports shall
, accompany each report. Such a letter shall include
a discussion of requirement violations found during
the reporting period and actions taken or planned
for correcting any requirement violation. If the
dischargers have previously submitted a detailed
time schedule for correcting requirement violations,
a reference to this correspondence * will be
satisfactory. Monitoring reports and the letter
-------
Self Monitoring Plan
Intel Santa Clara 3
Page 3
transmitting reports shall be signed by either a
principal executive officer or his duly authorized
employee. The letter shall contain a statement by
the official, under penalty of perjury, that to the
best of the signer's knowledge the report is true
and correct.
c. Data Results:
(1) Results from each required analysis and
observation shall be submitted in the quarterly
self-monitoring regular reports. Results shall
also be submitted for any additional analyses
performed by the discharger at the specific
request of the Regional Board. Quarterly water
level data shall also be submitted in the
quarterly report.
(2) The quarterly report shall include a discussion
of unexpected operational changes which could
affect performance of the extraction system,
such as flow fluctuations, maintenance
shutdown, etc.
(3) The quarterly report shall also identify the
analytical procedures used for analyses either
directly in the report or by reference to a
standard plan accepted by the Regional Board's
Executive Officer. Any special methods shall
be identified and shall have prior approval of
the Executive Officer.
(4) Original lab results shall be retained and
shall be made available for inspection for six
years after origination or until after all
continuing or impending legal or administrative
actions are resolved.
(5) Maps shall accompany the quarterly report,
showing sampling locations and pollutant plume
contours.
(6) The dischargers shall describe in the quarterly
monitoring report the effectiveness of the
actions taken to regain compliance if
compliance is not achieved. The effectiveness
evaluation shall include the basis of
determining the effectiveness, water surface
elevations for each well used to determine
water surface elevation contours and water
quality data.
-------
Self Monitoring Plan
Intel Santa Clara 3
Page 4
(7) The annual report shall be combined with the
quarterly report submitted on January 31, of
each year and shall include cumulative data
for the current year for each parameter of the
attached Table 2. The annual report shall also
include minimum, maximum, median and average
water quality data for the year. Water level
data and GC/MS results shall be included in the
annual report. The annual report shall also
include contour maps for each chemical present
above detectable concentrations.
Self-Monitoring Program (SMP) Revisions:
Additional long term or temporary changes in the
sample collection frequency and routine chemical
analysis may become warranted as monitoring needs
change. These changes shall be based on the
following criteria and shall be proposed in a
quarterly report. The changes shall be implemented
no earlier than 45 days after a self-monitoring
report is submitted for review or not at all if the
proposal is found to be unacceptable by the Regional
Board's Executive Officer.
Criteria for SMP revisions:
(1) Discontinued analysis for a routine chemical
parameter for a specific well after a one-year
period of below detection limit values for that
parameter.
(2) Changes in sampling frequency for a specific
well after a one-year period of below detection
limit values for all chemical parameters from
that well.
(3) Temporary increases in sampling frequency or
changes in requested chemical parameters for
a well or group of wells because of a change
in data needs (e.g., evaluating groundwater
extraction effectiveness or other cleanup
strategies).
(4) Add routine analysis for a chemical parameter
if the parameter appears as an additional
chromatographic peak in three consecutive
samples from a particular well.
(5) Add routine chemical parameters for new wells
based on the results of initial GC/MS analysis.
(6) Alter sampling frequency based on evaluation
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Self Monitoring Plan
Intel Santa Clara 3
Page 5
of collective data base.
(7) Following a temporary increase in sampling
frequency, as described in C.I, the regular
sampling frequency will resume after 4 samples
show stable or decreasing concentrations
provided the sampling indicates compliance with
the Site Cleanup Requirements.
D. DESCRIPTION OF GROUNDWATER SAMPLING STATIONS
Stations Description
Listed in Table 1 All current and future
and shown in Figure 1 monitoring and extraction
wells.
E. SCHEDULE AND CONDITIONS OF SAMPLING AND ANALYSIS
The schedule and conditions of sampling and analysis shall be
as given herein and as shown on Table 3:
1. Once every three months, while cleanup standards are
being achieved, representative samples shall be collected
for analyses from monitoring wells listed in Table 1 and
as shown on Figure 1. All samples of one event shall be
collected at approximately the same time.
2. For any new extraction or monitoring well that may be
constructed, sampling and analysis shall be conducted on
a quarterly schedule for a term to be decided by the
Regional Board's Executive Officer but not less than one
year. A GC/MS analysis shall be performed on each new
well immediately after installation and well development
and all peaks identified and reported on each well in the
next quarterly report.
3. After cleanup standards have been achieved, samples shall
be collected for analyses from all monitoring and
extraction wells identified in E.I. above, quarterly
(every three months) during the one-year stability
period.
4. Following completion of the stability period, samples
shall be collected for analyses from all identified wells
shown on Table 3 , twice annually during the long-term
monitoring period, as long as cleanup standards are not
exceeded, or as shall be determined by the Regional
Board's Executive Officer. The long term monitoring
period shall not last for less than five years after the
end of the one-year stability period. At the end of the
long term monitoring period, specific wells will be
identified for biannual post closure monitoring. At this
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Self Monitoring Plan
Intel Santa Clara 3
Page 6
tine the post closure monitoring period is expected to
last approximately twenty-five years after the end of the
long term monitoring.
5. If a previously undetected compound or peak is detected
in a sample from a well, a second sample shall be taken
within a week after the results from the first sample are
available. All chroroatographic peaks detected in two
consecutive samples for purgeable halocarbons and/or
volatile organics shall be identified and quantified in
the quarterly report.
6. A GC/MS analysis shall be performed annually and all
peaks identified and reported for all operating
extraction wells and pits.
7. All chemical analyses shall have detection limits below
the state action level for water for all constituents
analyzed.
8. Groundwater elevations shall be obtained and reported on
a quarterly basis from each monitoring and extraction
well listed in Table 1. In addition, the depth of the
pump in all extraction wells shall be obtained and
submitted in the quarterly report with the sampling
results.
9. Depths of wells in Table 1 shall be determined on an
annual basis and compared to the depth of the well as
constructed. The results of this comparison shall be
reported in the annual report specified in 3.C.(1).
I, Steven R. Ritchie, Regional Board 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 to determine compliance with
Regional Board Order No. 90-105.
2. Is effective on the date shown below.
3. 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.
Effective Date: July 18, 1990
Steven R. Ritchie
Executive Officer
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Self Monitoring Plan
Intel Santa Clara 3
Page 7
Attachments: Table 1 - List of wells identified for the self
monitoring program.
Table 2 - Final Cleanup Standards.
Table 3 - Monitoring Frequency.
Figure 1 - Facility map including well locations.
-------
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INTEL SANTA CLARA J
BUILDING
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-------
TABLE 1
SCHEDULE FOR SAMPLING, MEASUREMENTS, AND ANALYSIS
INTEL SANTA CLARA 3 FACILITY
2800 NORTHWESTERN PARKWAY
SANTA CLARA
SAMPLING STATION »»
TYPE OF SAMPLE
EPA 8010 for:
purgeable priority
pollutants,
Freon-113, and
Freon 11
1
GC/MS (EPA 8240)
Open Scan
i
SC3-1,2,2
9A,1(
6
Q
I/I.
l,4,5A,5B,6
>A,E1, and
>A,6B,7A,7E
E2.
......... i
J,8A
LEGEND FOR TABLE 1
G « grab sample
Q » quarterly
l/Y - once per year
* EPA 6010 not required for months when EPA 8240 is performed.
-------
TABLE 2
FINAL CLEANUP STANDARDS
INTEL CORPORATION
INTEL SANTA CLARA 3 FACILITY
2800 NORTHWESTERN PARKWAY
SANTA CLARA
Chemical Cleanup Standard 1989
(ug/1) Maximum
: fua/11
POTENTIAL CARCINOGENS
1,1-dichloroethane (1,1-DCA) 5 ND
1,2-dichloroethane (1,2-DCA) 0.5 ND
1,1-dichloroethylene (1,1-DCE) 6 ND
trichloroethylene (TCE) 5 140
NONCARCINOGENS
1,2-dichloroethylene (1,2-DCE)
cis 6 ND
trans 10 ND
1,1,1-trichloroethane (1,1,1-TCA) 200 2.1
Freon 113 1,200 35.0
Freon 11 150 ND
>*'
California State Maximum Contaminant Level (adopted),
21989 Maximum Concentration Levels at SC3 (ug/1).
ND - Not Detected
-------
TABLE 3
SELF MONITORING PLAN
INTEL CORPORATION
INTEL SANTA CLARA 3 FACILITY
2800 NORTHWESTERN PARKWAY
SANTA CLARA
MONITORING FREQUENCY
Monitoring Phase
Tine Length
Monitoring
Frequency
Sampling Station
Cleanup Phase
(Cleanup Standards
not achieved)
Estimated 11
Years
Quarterly
All Wells
One Year Stability
Phase (Cleanup
Standards achieved)
One Year
Quarterly
All Wells
Long Term Phase
Five Years
Twice
Annually
SC3-1, 6A, 7A,
9A, and 6B
Post Closure
Monitoring Phase
Twenty-five
Years
Every other
year
SC3-1, 6A, 7A
9A, and 6B
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
1235 Mission Street
San Francisco, CA 94103
CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD
SITE CLEANUP REQUIREMENTS
INDEX
SITE LOCATION 1
REASON FOR ACTION 1
RESPONSIBLE PARTY 1
SITE CHRONOLOGY 1
LEAD AGENCY 2
HYDROGEOLOGY . 2
SUBSURFACE INVESTIGATION . 2
SOURCE IDENTIFICATION .3
INTERIM ACTIONS 3
NPDES DISCHARGE 4
RI/FS REPORT AND REMEDIAL ACTION PLAN (RAP) 4
CLEANUP ALTERNATIVES 5
FINAL RAP 5
GROUNDWATER CLEANUP STANDARDS 7
TIME REQUIRED TO REACH CLEANUP STANDARDS 7
RISK ASSOCIATED WITH CLEANUP STANDARDS 7
FUTURE CHANGES TO CLEANUP STANDARDS 8
GROUNDWATER CONSERVATION 9
COMMUNITY INVOLVEMENT 9
STATE BOARD RESOLUTION 68-16 10
STATE BOARD RESOLUTION 88-63 11
PROHIBITIONS ' 12
SPECIFICATIONS 12
PROVISIONS 14
ATTACHMENTS 23
SITE LOCATION MAP
SITE MAP OF INTEL SANTA CLARA 3 (showing
distribution of TCE in the A Water-Bearing
Zone, August 16, 1989)
-------
CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD
SAN FRANCISCO BAY REGION
ORDER No. 90-105
AN ORDER PRESCRIBING SITE CLEANUP REQUIREMENTS AND
RESCINDING ORDER No. 89-064 FOR:
INTEL CORPORATION
INTEL SANTA CLARA 3 FACILITY
2800 NORTHWESTERN PARKWAY
SANTA CLARA
SANTA CLARA COUNTY
The California Regional Water Quality Control Board, San Francisco
Bay Region (hereinafter called the Regional Board) finds that:
1. Site Location. Intel Corporation, hereinafter called the
discharger, owns and operates the Intel Santa Clara 3 Facility
(SC3) which performs quality control of chemicals and
electrical testing of semiconductors. The SC3 site is located
at 2800 Northwestern Parkway, Santa Clara, Santa Clara County
(Figures 1 and 2) near the intersection of Bowers Avenue and
the Central Expressway. SC3 has been in operation since 1976.
2. Reason for Action. The site overlies the Santa Clara Valley
groundwater basin. Groundwater from this basin provides up
to 50% of the municipal drinking water for the 1.4 million
residents of the Santa Clara Valley. In 1989, groundwater
accounted for approximately 128,000 of the 315,000 acre feet
of drinking water delivered to Santa Clara Valley Water
District customers. The Intel SC3 site is on the National
Priority List (NPL) primarily because of the past chemical
releases' potential threap to the quality of this valuable
resource.
3. Responsible Party. Pursuant to Health and Safety Code
Sections 25356.1 (c) and (d), the discharger is the only
identified or known responsible party associated with the
release of pollutants to the subsurface at this location.
4. Site Chronology. The site is on the NPL and is regulated by
Regional Board Orders, as indicated herein:
a. September 15, 1982 Intel submits completed Regional
Board Facility Questionnaire.
b. October 15, 1984 Site proposed for the NPL.
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Final Site Cleanup
Requirements - Intel Santa Clara 3
Page 2
c. October 30, 1984 Regional Board staff approves Intel's
proposal for interim remedial
measures.
d. March 19, 1986 Regional Board adopted NPDES Permit
No. CA0028941, for the discharge of
treated groundwater.
e. June, 1986 Site added to the final NPL.
f. April 19, 1989 Regional Board adopted Order No. 89-
064 issuing Site Cleanup Requirements
and approving the Remedial
Investigation / Feasibility Study
(RI/FS) workplan.
5. Lead Agency. Pursuant to the South Bay Multi-Site Cooperative
Agreement and the South Bay Ground Water Contamination
Enforcement Agreement, entered into on May 2, 1985 (as
subsequently amended) by the Regional Board, EPA and DHS, the
Regional Board has been acting as the lead regulatory agency
for this NPL site. The Regional Board will continue to
regulate the discharger's remediation and administer
enforcement actions under CERCLA as amended by SARA, the
California Water Code, Health and Safety Code, and regulations
adopted there under.
6. Hydrogeologv. The facility is in the Santa Clara Valley which
is a sedimentary basin filled with unconsolidated
heterogeneous alluvial material up 1500 feet thick. The
alluvium is a mixture of permeable water-bearing sands and
gravels interbedded with less permeable silts and clays. The
soils are extremely variable over short distances, both
horizontally and vertically..
Two water bearing layers, designated as the A and B zones,
have been identified at SC3. The shallowest, or A zone, has
its upper boundary at about 10 to 18 feet deep, and lower
boundary about 25 to 27 feet deep. The top of the B zone is
29 to 36 1/2 feet deep, and the bottom of the B zone is
between 35 1/2 to 43 feet deep. The A and B water bearing
zones are separated by an aquitard of 5 to 10 feet of silty
clay to clayey silt.
Water in the A and B zones at this site is not withdrawn for
any use other than interim remedial action at present.
7. Subsurface Investigation. In early 1982, the Regional Board
initiated a leak detection program to define the extent of
leakage from underground storage tanks and pipes in- the South
Bay area. As a result of these efforts, subsurface
investigations at SC3 have detected the following chemicals
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Final Site Cleanup
Requirements - Intel Santa Clara 3
Page 3
in the A water bearing zone at the historical high of:
trichloroethylene (TCE) at 490 parts per billion (ppb); 1,1,1
trichloroethane (1,1,1 TCA) at 810 ppb; 1,1 dichloroethylene
(1,1 DCE) at 84 ppb; 1,1 dichloroethane (1,1 DCA) at 8.2 ppb;
1,2 dichloroethane (1,2 DCA) at 16.0 ppb; cis-1,2
dichloroethylene (cis-1,2 DCE) less than 7.8 ppb; trans-1,2
dichloroethylene (trans-1,2 DCE) less than 7.8 ppb; Freon 113
at 1300 ppb; and Freon 11 at 2.8 ppb.
Since 1982, the discharger has installed eleven A zone
monitoring wells and four B zone monitoring wells to define
the vertical and horizontal extent of the plume. The oval
shaped plume covers an area approximately 400 feet by 300
feet. The vertical extent of groundwater pollution in the A
zone extends to the bottom of well SC3-3 at a depth of 27.5
feet. Only trace levels of groundwater pollution have been
found to date in B zone monitoring wells. The vast majority
of samples collected and analyzed from the B zone have not
detected any volatile organic chemicals (VOCs). Occasionally,
VOCs have been detected in the B zone, usually at
concentrations below 1 ppb.
8. Source Identification. No source of the groundwater pollution
has ever been positively identified at the site. Three
potential sources have been proposed and, to the extent
practical, evaluated. The potential sources are: 1) leaks
from the secondarily contained acid waste neutralization tank,
2) accidental spills near the above ground solvent storage
facility, and 3) speculated solvent spills associated with
cleaning out pipes put in place during the construction of the
SC3 building.
While positive identification of a pollution source has not
been possible at SC3, by performing the evaluations of
potential sources described above, it has been possible to
determine that there is no source continuing to contribute
pollutants to SC3's existing groundwater pollution and to
develop a remedial action plan that considers the possible
affect of residual pollutants in the vadose zone.
9. Interim Actions. The discharger has been extracting A zone
groundwater from two extraction wells since February, 1985.
A general decline in groundwater pollution levels has been
observed in all but one of the wells at SC3 since pumping
started. Prior to implementing Interim Remedial Actions, the
groundwater contained levels of TCE up to 490 parts per
billion (ppb), TCA up to 810 ppb, 1,1 DCE up to 84 ppb, and
Freon 113 up to 1300 ppb. As of November, 1989, TCE, at a
maximum of 140 ppb, is the only pollutant found in the
groundwater exceeding drinking water standards.. As of
November 1989, Intel had withdrawn 28 million gallons of
-------
Final Site Cleanup
Requirements - Intel Santa Clara 3
Page 4
groundwater and removed approximately 29 pounds of VOCs from
the groundwater beneath the site.
10. NPDES Discharge. The extracted groundwater is treated and
then discharged to a storm sewer system tributary of San Tomas
Aquino Creek. Currently, approximately 20,000 gallons per day
of groundwater is discharged as specified under NPDES Permit
ICA0028941. San Tomas Aquino Creek is a tributary of
Guadalupe Slough which flows into south San Francisco Bay.
Effluent limits set in the permit prohibit the discharge of
groundwater containing concentrations greater than 5 ppb for
the individual VOCs identified at the site. The permit
expires on March 19, 1991. The discharger must file a Report
of Waste Discharge in accordance with Title 23, California
Administrative Code, not later than 180 days in advance of the
expiration date as application for issuance of new waste
discharge requirements.
11. RI/FSReport and Remedial Action Plan fRAP)... The discharger
has submitted a RI/FS Report, dated February 16, 1990, which
satisfies the requirements of Regional Board Order No. 89-064,
Site Cleanup Requirements. The report contains the results
of the subsurface investigation, a description of the
groundwater pollution, and an evaluation of the interim
cleanup actions, remedial alternatives, groundwater
conservation measures.
Based on the recommendation in the March 30, 1990 (revised
June 19, 1990) staff report (Internal Memo from Gregory Bartow
to Steven Ritchie), the Regional Board has determined that the
technical information contained in the RI/FS is acceptable for
developing a final Remedial Action Plan (RAP) for the site.
In making this recommendation, staff did not accept the
portions of the RI/FS addressing: 1) Applicable or Relevant
and Appropriate Requirements (ARARs), 2) Asymptotic Levels,
and 3) The Selected Remedy. These areas are addressed in the
Addendum to the RI/FS dated March 30, 1990, prepared by
Regional Board staff. The RI/FS submitted February 16, 1990,
as modified by the Addendum, the March 30, 1990 staff report
(revised June 19, 1990), this Order, and Order No. 86-14
(NPDES Permit No. CA 0028941), satisfies the requirements of
the California Water Code Section 13304 and the Health and
Safety Code Section 2536.1, Section 121 of CERCLA; is
protective of human health and the environment; attains ARARs;
utilizes permanent solutions and alternative treatment
technologies and resource recovery technologies to the maximum
extent possible for short-term effectiveness; is
implementable; is cost effective; is acceptable based on State
regulations, policies, and guidance; and reduces toxicity,
mobility, and volume of pollutants.
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Final Site Cleanup
Requirements - Intel Santa Clara 3
Page 5
12. Cleanup Alternatives. In the Feasibility Study, the
discharger initially screened eleven remedial action
technologies. Technologies or their components which are
environmentally unsound, difficult to implement, ineffective,
or have limited effectiveness were eliminated from further
consideration. Technologies or their components which were
considered potentially applicable for SC3 were further
screened based on effectiveness, implementability and cost.
The remedial technologies that survived the further screening
were assembled into a group of alternative and evaluated in
detail. A complete description of these alternatives is
contained in the RI/FS dated February 16, 1990. The
alternatives were evaluated based on nine criteria: 1)
overall protection of human health and the environment; 2)
compliance with ARARs; 3) long-term effectiveness and
permanence; 4) reduction of toxicity, mobility or volume; 5)
short-term effectiveness; 6) implementability; 7) cost; 8)
State acceptance; and 9) community acceptance.
13. Final RAP. Based primarily on information submitted by the
discharger in the RI/FS Report, this Order provides for a
final RAP that includes:
a. Continued groundwater extraction 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
discharger must demonstrate to the satisfaction of the
Regional Board that he 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.
b. Submittal of a proposal for conducting a demonstration
project to evaluate various groundwater pumping
strategies for cleaning up residual levels of volatile
organic chemicals (VOCs) left behind in aquifer material
once conventional groundwater pump and treat is shown to
be less effective. Pulsed pumping implies the cycling
of extraction wells on and off in pumping and nonpuroping
periods. During the nonpumping period, groundwater
levels will rebound. In theory, this could provide
greater contact time between the shallow soils and
groundwater, and potentially allow VOCs adsorbed to soil
-------
Final Site Cleanup
Requirements - Intel Santa Clara 3
Page 6
particles to desorb back into the groundwater, allowing
further extraction of VOCs.
c. Maintenance of hydraulic control to prohibit the further
vertical and horizontal migration of the groundwater
pollution. This requirement shall remain in effect until
cleanup standards are achieved. The only exception to
this requirement shall be to allow the dischargers to
temporarily stop groundwater extraction as part of the
demonstration project described in Finding 12.b.
d. Continued quarterly groundwater monitoring at the site
during the cleanup period. An additional monitoring well
will be installed between wells SC3-1A and SC3-7A. Water
levels will be measured to verify that hydraulic control
of the groundwater pollution is maintained. Water
samples will continue to be collected to verify that
cleanup is proceeding and that there is no migration of
VOCs, above cleanup standard levels, beyond current
boundaries or into the deeper B zone. The frequency of
monitoring will be decreased from quarterly to biannually
once cleanup standards have been achieved and stabilized
for one year. Detailed sampling and reporting
requirements for the site are contained in the attached
Self-Monitoring Plan for SC3.
e. Continued groundwater extraction at the two existing
wells SC3-E1 and SC3-E2. In addition, at least one new
extraction well, in the vicinity of SC3-7A, will be
installed. . To increase the efficiency of groundwater
extraction, additional extraction wells may be necessary
in the future. The need for different and/or additional
extraction well locations will be evaluated at least once
every year.
f. Treatment of extracted groundwater with a granular
activated charcoal (GAC) system to remove VOCs. An
existing GAC system has been implemented to treat
groundwater from the two existing extraction veils.
The treated groundwater will continue to be discharged
to San Tomas Aquino Creek, under existing NPDES Permit
No. CA0028941. Regional Board staff believes that the
beneficial use of San Tomas Aquino Creek will not be
affected by continuing this discharge.
g. A deed restriction. The discharger shall be required to
file a deed restriction prohibiting use of on-site
shallow groundwater for drinking water and controlling
other subsurface activities. The deed restriction shall
remain in place until safe drinking water levels are
achieved.
-------
. Final Site Cleanup
Requirements - Intel Santa Clara 3
Page 7
14. Groundwater Cleanup Standards. Cleanup standards (also known
as goals) are set at California proposed or adopted Maximum
Contaminant Levels (MCLs). Board staff view these cleanup
standards as conservative. In cleaning up TCE to the 5 ppb
cleanup standard it is quite likely that the concentration of
the other chemicals will be reduced below detection levels.
These cleanup standards are defined in Specification B.4.
15. Time Required to Reach Cleanup Standards. Intel estimates
that it will take 11 years to reduce the concentration of TCE
to the cleanup standard of 5 ppb in all monitoring, wells at
the site. The total present worth cost of the cleanup plan
is $637,000. Intel also notes that the cost and time to
cleanup are only rough estimates, and in all likelihood
underestimate both the time and the cost for cleanup.
16. RiskAssociated 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 EPA's acceptable Carcinogenic Risk
range. The risk due to non-carcinogens at this site was
assessed using the Hazard Index. If the Hazard Index is less
than one, the combined intake of chemicals is unlikely to pose
a health risk.
The Carcinogenic Risk associated with the potential future use
scenario of groundwater ingestion and inhalation of VOCs is
1.3xlO~5. The Regional Board regards the Carcinogenic Risk
associated with the cleanup standards as extremely
conservative. Currently TCE is the only VOC detected at the
SC3 above drinking water standards. However other VOCs have
been detected in the past and may be detected in the future.
In cleaning up TCE to the 5 ppb cleanup standard, it is quite
likely that concentration of other VOCs will be reduced to
levels below detection limits. The Carcinogenic Risk
associated with the 5 ppb cleanup standard for TCE alone is
1.5X10'6'
The Hazard Index associated with the cleanup standards is 0.2.
The method and assumptions used to obtain the Carcinogenic
Risk and the Hazard Index associated with the cleanup
standards are contained in the March 30, 1990 staff report
(revised June 19, 1990). Thus, the Regional Board finds that
the cleanup 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..
The Carcinogenic Risk and Hazard Index associated with the
cleanup standards are based on a hypothetical scenario in
which the site is redeveloped residential and a private
-------
Final Site Cleanup
Requirements - Intel Santa Clara 3
Page 8
shallow drinking water well is installed in the affected
groundwater. This private well is then used for a duration of
30 years. As such, the Carcinogenic Risk and Hazard Index
associated with the cleanup standards represent a maximum
plausible risk. For consistency, this scenario is being used
in accessing the risk at all of the sites on the NPL where the
Regional Board is the lead agency.
17. Future Changes to Cleanup Standards. If new information
indicates cleanup standards cannot reasonably be attained or
can reasonably be surpassed, the Regional Board will decide
if further final cleanup 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 cleanup
standards as defined in Specification B.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 that 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 indicates that the
remedial actions required in this Order may not be protective
of public health and the environment. The Regional Board will
also consider technical practicality, cost effectiveness,
State Board Resolution No. 68-16 and other.factors evaluated
by the Regional Board in issuing this Order in determining
-------
Final Site Cleanup
. Requirements - Intel Santa Clara 3
Page 9
whether such additional remedial actions are appropriate and
necessary.
18. Groundwater Conservation. The discharger has considered the
feasibility of reclamation, reuse, or discharge to a publicly
owned treatment works (POTW) of treated, extracted
groundwater, as specified in Board Resolution No. 88-160.
Reclamation of extracted groundwater at SC3 was tried in 1986.
Extracted groundwater was routed through the facility's wet
air scrubber. However, scaling caused by the high hardness
of the groundwater quickly shut down the scrubber. The
discharger claims the independent operational requirements of
the scrubber and the groundwater extraction system may only
be overcome by installing a complex and expensive system of
process controls and backup systems. The only other
substantial use of water at SC3 is landscape irrigation.
However, the total area of landscaping is less than one acre;
the present 20,000 gallon per day flow would apply more than
1/2 inch of water per day or 200 inches per year to the
landscaping, far more than it could absorb, especially in the
rainy season. Thus, the discharger believes reclamation or
reuse of treated, extracted groundwater at SC3 is not
feasible. Since the City of Santa Clara does not allow any
discharges of treated ground water into its sewer system on
a permanent basis, the Regional Board concurs that treated,
extracted groundwater reclamation, reuse, or discharge to a
POTW at SC3 is not feasible.
However, the RAP requires submittal of a proposal for a
demonstration project evaluating pulsed pumping at the site,
(as described in Finding 13.b.) which may decrease the amount
of treated groundwater discharged to surface waters. Three
features which may decrease the amount of groundwater
discharged are : 1) theoretically, pulsed pumping allows for
the removal of a minimum volume of polluted ground water, at
the maximum possible concentrations, thus reducing the total
amount of groundwater extracted, 2) the discharger will be
required to evaluate returning extracted groundwater to the
source aquifer as part of the demonstration project proposal,
and 3) the discharger will be required to evaluate the
feasibility of partial reclamation of the extracted
groundwater through irrigation as part of the demonstration
project proposal.
19. Comnmnity Involvement. An aggressive Community Relations
program has been ongoing for all Santa Clara Valley Superfund
sites, including the SC3 site. The Regional Board published
a notice for SC3 and two other sites in the Peninsula Tiroes
Tribune on April 11, 1990, announcing the proposed final RAP
and opportunity for public comment at the Regional Board
Public Hearing of April 18, 1990 in Oakland. This Regional
Board Hearing began the 30 day public comment period. The
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Final Site Cleanup
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April 11, 1990 notice also announced an evening public meeting
held at the Santa Clara Convention Center in the City of Santa
Clara on May 2, 1990. The notice announcing the public
meeting was published again in the Peninsula Times Tribune on
April 18, and April 25, 1990.
Fact Sheets were mailed to interested residents, local
government officials, and media representatives. Fact Sheet
1, mailed in January, 1990, summarized the pollution problem,
the results of investigations to date, and the interim
remedial actions. Fact Sheet 2, mailed in April, 1990,
described the cleanup alternatives evaluated, explained the
proposed final RAP, announced opportunities for public comment
at the Regional Board Hearing of April 18, 1990 in Oakland and
the Public Meeting of May 2, 1990 in Santa Clara, and
described the availability of further information at the
Information Repository at the Santa Clara Public Library.
Public concerns 'expressed at the Board Hearing and at the
Public Meeting, and in comments received by the Regional Board
through May 18, 1990, the close of the public comment period,
were reviewed and evaluated. A Responsiveness Summary was
prepared dated June 19, 1990. Based upon comments received,
amendments were incorporated by appropriate response in this
Order. While the official public comment period ran from
April 18, 1990 to May 18, 1990; public comment was allowed up
to the adoption of this Order at the July 18, 1990 Regional
Board Public Hearing. However, only comments received prior
to May 18, 1990 were addressed in the Responsiveness Summary.
Fact Sheet 3, to be mailed in September, 1990, will explain
the final adopted cleanup plan contained in this Order.
20. State Board Resolution 68-16. On October 28, 1968, the State
Board adopted Resolution No. 68-16, "Statement of Policy with
Respect to Maintaining High Quality Waters in California11.
This policy calls for maintaining the existing high quality
of State waters unless it is demonstrated that any change
would be consistent with the maximum public benefit and not
unreasonably affect beneficial uses. The original discharge
of waste to the groundwater at this site was in violation of
this policy; therefore, the groundwater quality needs to be
restored to its original quality to the extent reasonable.
For the purpose of establishing cleanup objectives, the
shallow groundwater at the site is designated a potential
source of drinking water, and protective levels shall be those
levels which have been established as protective of drinking
water. State Board Resolution 68-16 is an ARAR for the site.
21. State Board Resolution 88-63. On March 30, 1989, the Regional
Board incorporated the State Board Policy of "Sources of
Drinking Water" into the Basin Plan. The policy provides for
a Municipal and Domestic Supply designation for all waters of
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Final Site Cleanup
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the State with some exceptions. Groundwaters of the State are
considered to be suitable or potentially suitable for
municipal or domestic supply with the exception of: 1) the
total dissolved solids in the groundwater exceed 3000 mg/L,
and 2) the water source does not provide sufficient water to
supply a single well capable of producing an average,
sustained yield of 200 gallons per day. Based on data
submitted the discharger, the Regional Board finds that
neither of these two exceptions apply to the A zone at SC3.
Thus, the A zone at SC3 is a potential source of drinking
water.
22. Development of the Regional Board's final Remedial Action Plan
was based on the Regional Board's evaluation of eight years
of water and soil quality data. Random samples have been
collected and analyzed by the Regional Board to confirm the
validity of data generated by the discharger. Data has been
validated using EPA validation guidance. Some data was
determined to be questionable, however, other data was
determined to be both qualitatively and quantitatively
acceptable. The Regional Board finds that there is sufficient
acceptable data to make cleanup decisions.
23. The Regional Board adopted a revised Water Quality Control
Plan for the San Francisco Bay Basin (Basin Plan) on December
16, 1986. The Basin Plan contains water quality objectives
and beneficial uses for South San Francisco Bay and contiguous
surface and underground waters.
24. The existing and potential beneficial uses of the groundwater
underlying and adjacent to the facility include:
a. Industrial process wetter supply
b. Industrial service water supply
c. Municipal and domestic water supply
d. Agricultural water supply
25. The discharger has caused or permitted, and threatens to cause
or permit, pollution 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. Final containment and remediation measures need to
be implemented to alleviate the threat to the environment
posed by the plume of pollutants.
26. Groundwater cleanup objectives are: (1) restore the quality
of a polluted water source to its potential suitability as a
drinking water supply, (2) prevent exposure to polluted water,
and (3) prevent migration of polluted groundwater to the
deeper aquifers (C zone) which presently supply 'water for
domestic (drinking) and other beneficial uses.
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27. This action is an order to enforce the laws and regulations
administered by the Regional Board. This action is
categorically exempt from the provisions of the CEQA pursuant
to Section 15321 of the Resources Agency Guidelines.
28. The Regional Board has notified the discharger and interested
agencies and persons of its intent under California Water Code
Section 13304 to prescribe Site Cleanup 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.
29. The Regional 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, that the discharger 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 will degrade water quality or adversely
affect the beneficial uses of the waters of the State is
prohibited.
2. Further significant migration of chemicals through
subsurface transport to waters of the State is
prohibited.
3. Activities associated with the subsurface investigation
and cleanup which xwill cause significant adverse
migration of chemicals are prohibited.
B. SPECIFICATIONS
1. The storage, handling, treatment or disposal of soil or
groundwater containing chemicals shall not create a
nuisance as defined in Section 13050 (m) of the
California Water Code.
2. The discharger shall conduct monitoring activities as
needed to define the current local hydrogeologic
conditions, and the lateral and vertical extent of soil
and groundwater containing chemicals. Should monitoring
results show evidence of continuing pollutant migration,
additional plume characterization may be required.
3. The identification of which wells are to be used to
determine if cleanup standards have been achieved may be
modified by the Executive Officer. Currently the wells
identified for determining that cleanup standards have
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Final Site Cleanup
Requirements - Intel Santa Clara 3
Page 13
been achieved are those herein and all other onsite and
offsite wells that nay be installed for monitoring or
extraction:
Extraction Wells: SC3-E1,E2
Monitoring Wells: . SC3-1,2,3,4,5A,5B,6A,6B,
7A,7B,8A,9A, and 10A
Final cleanup standards for all.onsite and offsite wells
shall not be greater than the levels as provided in
Finding 14. The numerical final cleanup standards,
therefore, shall not exceed the following in any well
during the one year stability period as set forth in the
Self-Monitoring Plan for SC3:
Chemical Cleanup Standard 1989
(ug/1) Maximum
fua/11
POTENTIAL CARCINOGENS
1,1-dichloroethane (1,1-DCA) 5 ND
1,2-dichloroethane (1,2-DCA) 0.5 ND
1,1-dichloroethylene (1,1-DCE) 6 ND
trichloroethylene (TCE) 5 140
NONCARCINOGENS
1,2-dichloroethylene (1,2-DCE)
cis . -,-. 6 ND
trans 10 ND
1,1,1-trichloroethane (1,1,1-TCA) 200 2.1
Freon 113 1,200 35.0
Freon 11 150 ND
California State Maximum Contaminant Level (MCL) for
Drinking Water (adopted).
21989 Maximum Concentration Levels at SC3 (ug/1).
ND - Not Detected (detection levels ranged from 0.5 to
5.0 ug/1).
5. The discharger shall implement the final cleanup plan
described in Finding 13.
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Final Site Cleanup
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C. PROVISIONS
1. The discharger shall submit to the Regional Board
acceptable monitoring program reports containing results
of work performed according to a program prescribed by
the Regional Board's Executive Officer.
2. The discharger shall comply with this Order immediately
upon adoption and the discharger shall further comply
with the PROHIBITIONS and SPECIFICATIONS above, in
accordance with the following tasks and compliance'time
schedule:
a. DEMONSTRATION PROJECT
1) COMPLETION DATE: July 31, 1990
TASK 1: PROPOSAL FOR DEMONSTRATION PROJECT.
Submit a technical report acceptable to the
Executive Officer containing a proposal and a
schedule for conducting a demonstration project
of pulse pumping that considers the issues
contained in the Regional Board staff report
dated March 30, 1990 (revised June 19, 1990).
This report shall contain criteria to judge the
future performance of the demonstration
project. This report shall also evaluate the
feasibility, including cost estimates, of
returning extracted groundwater to the source-
aquifer, and the partial reclamation of the
extracted groundwater through irrigation. The
report shall- include an implementation schedule
for these measures. If the discharger proposes
that reinfiltration and reclamation are
infeasible, the report shall include
documentation that a) groundwater
reinfiltration and reclamation is infeasible,
or b) a proposal for active groundwater
reinfiltration and reclamation. This report
may be contained in the quarterly status report
due July 31, 1990.
2) COMPLETION DATE: January 31, 1991
TASK 2: DEMONSTRATION PROJECT STATUS REPORT.
Submit a technical report acceptable to the
Executive Officer which includes a status
report and results of the demonstration project
to date. This report may be contained in the
quarterly status report due January 31, 1991.
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Final Site Cleanup
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Page 15
3) COMPLETION DATE: July 31, 1991
TASK 3: DEMONSTRATION PROJECT, EVALUATION AND
RECOMMENDATIONS FOR FURTHER ACTIONS. Submit
a technical report acceptable to the Executive
Officer which includes an evaluation of the
demonstration project to date and
recommendation for further action. If the
report shows that pulsed pumping is feasible
then a schedule for full scale implementation
should be included. This report may be
contained in the quarterly status report due
July 31, 1991.
3) COMPLETION DATE: September 30, 1992
TASK 4: DEMONSTRATION PROJECT FINAL REPORT
Submit a technical report acceptable to the
Executive Officer which includes a final report
on the demonstration project.
b. UPDATING ADMINISTRATIVE RECORD
1) .COMPLETION DATE: August 15, 1990
TASK 5: PROPOSED UPDATE. Submit a technical
report acceptable to the Executive Officer
containing an updated index for the
Administrative Record for the period February
17, 1990 to July 30, 1990.
2) COMPLETION DATE: September 28, 1990
TASK 6: UPDATE ADMINISTRATIVE RECORD. Submit
a technical report acceptable to the Executive
Officer containing the updated Administrative
Record for the period February 17, 1990 to July
30, 1990.
C. INSTITUTIONAL CONSTRAINTS
1) COMPLETION DATE: July 31, 1990
TASK 7: PROPOSED CONSTRAINTS. Submit a
technical report acceptable to the Executive
Officer documenting procedures to be
implemented by the discharger, including a deed
restriction prohibiting the-use of the A zone
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Final Site Cleanup
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Page 16
groundwater as a source of drinking water, and
for controlling onsite activities that could
endanger the public health or the environment
due to exposure to VOCs. Constraints shall
remain in effect until groundwater cleanup
standards have been achieved and pollutant
levels have stabilized in onsite aquifers.
This report may be contained in the quarterly
status report due July 31, 1990.
2) COMPLETION DATE: September 28, 1990
TASK 8: CONSTRAINTS IMPLEMENTED. Submit a
technical report acceptable to the Executive
Officer documenting that the proposed and
approved constraints have been implemented.
d. EXTRACTION SYSTEM AND MONITORING SYSTEM
1) COMPLETION DATE: July 31, 1990
TASK 9: PROPOSAL FOR ADDITIONAL EXTRACTION
AND MONITORING WELLS NEAR SC3-7A. Submit a
technical report acceptable to the Executive
Officer which contains a proposal to install
additional extraction and monitoring wells in
the vicinity of SC3-7A as outlined in the
Feasibility Study. This report may be
contained in the quarterly status report due
July 31,.1990.
2) COMPLETION DATE: September 28, 1990
TASK 10: DOCUMENTATION OF INSTALLATION OF
ADDITIONAL EXTRACTION AND MONITORING WELLS NEAR
SC3-7A. Submit a technical report acceptable
to the Executive Officer which documents the
installation of additional extraction and
monitoring wells in the vicinity of SC3-7A as
outlined in the Feasibility Study.
3) COMPLETION DATE: 60 days prior to
implementation by the discharger
TASK 11: MODIFYING EXISTING EXTRACTION AND
TREATMENT SYSTEM OR MONITORING WELL SYSTEM.
Submit a technical report acceptable to the
Executive Officer which documents a proposal
to modify, workover or replace any existing
extraction well or pit, or install one or more
new extraction wells or pits associated with
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Final Site Cleanup
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Page 17
cleanup activities at this site; or a proposal
to modify the monitoring well system by making
major well-construction changes, abandoning an
existing well(s) or installing a new well(s).
This report is required only if a change is
proposed, and for all changes that are
proposed.
4) COMPLETION DATE: 30 days following
implementation by the discharger
TASK 12: IMPLEMENTATION OF CHANGE. Submit a
technical report acceptable to the Executive
Officer which documents any change made in the
extraction/treatment system and any major
change in the monitoring well systea.
e. CURTAILING ONSITE GROUNDWATER EXTRACTION
1) COMPLETION DATE: 90 days prior to proposed
implementation of onsite groundwater extraction
curtailment
TASK 13: ONSITE WELL PUMPING CURTAILMENT
CRITERIA AND PROPOSAL. Submit a technical
report acceptable to the Executive Officer
containing a proposal for curtailing pumping
from onsite groundwater extraction well(s) and
pit(s) and the criteria used to justify such
curtailment. This report shall include data
to show that groundwater 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. This report
shall also include an evaluation of the
potential for pollutants to migrate downwards
to the C aquifer at this location.
If the discharger determines that it is not
feasible to achieve cleanup standards, the
report shall evaluate the alternate standards
that can be achieved.
2) COMPLETION DATE; 30 days after the Regional
Board approves onsite curtailment.
TASK 14: IMPLEMENTATION OF ONSITE CURTAILMENT.
Submit a technical report acceptable to the
Executive Officer documenting completion of the
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Final Site Cleanup
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Page 18
necessary tasks identified in the technical
report submitted for Task 13.
f. STATUS REPORT
1) COMPLETION DATE: July 31, 1995
TASK 15: FIVE-YEAR STATUS REPORT AND
EFFECTIVENESS EVALUATION. Submit a technical
report acceptable to the Executive Officer
containing the results of any additional
investigation including results from the
demonstration project; 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 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 onsite, and if so, a
proposal for procedures to do so.
g. NEW HEALTH CRITERIA
1) COMPLETION DATE: 60 days after request made by
the Executive Officer
TASK 16: 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.
h. NEW TECHNICAL INFORMATION
1) COMPLETION DATE: 60 days after request made
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Final Site Cleanup
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Page 19
by the Executive Officer
TASK 17: 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 and/or technology in some
areas may be considered for revision. Such
technical reports shall not be required unless
the Executive Officer or the Regional Board
determines that such new information indicates
a reasonable possibility that the Order may
need to be changed under the criteria described
in Finding 17.
The submittal of technical reports evaluating additional
final remedial measures will include a projection of the
cost, effectiveness, benefits, and impact on public
health, welfare, and environment of each alternative
measure. If any additional remedial investigations or
feasibility studies are found to be necessary, they shall
be consistent with the guidance provided by Subpart E 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, CERCLA/SARA
guidance documents, the State Board's Resolution No. 68-
16, and this Order.
If the discharger is delayed, interrupted or prevented
from complying with this Order or meeting one or more of
the time schedules in this Order, the discharger shall
promptly notify the Executive Officer. In the event of
such delays or noncompliance, the Regional Board may
consider modification of the time schedules established
in this Order.
Technical reports summarizing the status of compliance
with the Prohibitions, Specifications, and Provisions
of this Order shall be submitted on a quarterly basis,
according to the schedule below, commencing with the
report for the second quarter 1990, due July 31, 1990.
Quarter
Period
Due Date
1st Quarter
Jan. -March
Aoril 30
2nd Quarter
April June
Julv 31
3rd Quarter
July-Sent.
October 31
4th Quarter
Oct . -Dec .
January 31
The quarterly reports shall include:
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Final Site Cleanup
Requirements - Intel Santa Clara 3
Page 20
a. a summary of work completed since the previous
quarterly report, and work projected to be completed
by the time of the next quarterly report,
b. appropriately scaled and labeled maps showing the
location of all monitoring wells, extraction wells,
and existing structures,
c. cross sections depicting subsurface geologic
. information and corresponding correlations showing
actual boring lithology data if new information has
changed interpretations since the previous quarter,
d. updated water table and piezometric surface maps for
all affected water bearing zones, and
isoconcentration maps for key pollutants in all
affected water bearing zones,
e. a cumulative tabulation of all well construction
data, groundwater levels and chemical analysis
results for site monitoring wells specified in the
sampling plan,
f. identification of potential problems which will
cause or threaten to cause noncompliance with this
Order and what actions are being taken or planned
to prevent these obstacles from resulting in
noncompliance with this Order, and
g. in the event of noncompliance with the Provisions
and Specifications of this Order, the report shall
include written justification for noncompliance and
proposed actions to achieve compliance.
6. On an annual basis beginning on January 31, 1991 or as
required by the Executive Officer, the discharger's
January 31 progress reports shall include, but need not
be limited to, an evaluation of the progress of cleanup
measures and the feasibility of meeting groundwater
cleanup standards established in this Order. This report
shall include a discussion of the efficiency of the
existing groundwater extraction wells at removing
groundwater pollution during the previous year. If
significant reductions in groundwater pollution levels
are not being achieved, then the report shall propose
construction of new and/or alternative extraction wells
in order to increase the efficiency of the groundwater
extraction system. If the discharger determines that it
is not feasible to meet the cleanup standards established
by this Order, the report shall also contain an
evaluation of maximum cleanup levels that could be
achieved.
7. 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 and submitted on recycled paper.
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Final Site Cleanup
Requirements - Intel Santa Clara 3
Page 21
8. All samples shall be analyzed by laboratories certified
to perform analysis on Hazardous Materials or
laboratories using approved EPA methods or an equivalent
method acceptable to the Executive Officer. The
discharger shall request laboratories to follow EPA
guidance, "Documentation Requirements for Data Validation
of Non-CLP Laboratory Data for Organic and Inorganic
Analyses", dated May 1988, and DHS guidance,
"Documentation Requirements for Project Data Packages",
dated December 29, 1989, for preparation of data
validation packages when required by the Executive
Officer. The discharger shall request the laboratories
to maintain quality assurance/quality control records for
Regional Board review for six years and will inform the
Regional Board of each laboratory's response.
9. The discharger shall maintain in good working order, and
operate as efficiently as possible, any facility or
control system or monitoring system installed to achieve
compliance with this Order.
10. Copies of all correspondence, reports, and documents
pertaining to compliance with the Prohibitions,
Specifications, and Provisions of this Order shall be
provided to:
a. Santa Clara Valley Water District
b. Santa Clara County Health Department
c. City of Santa Clara
d. U.S. Environmental Protection Agency, Region IX
(H-6-3)
Additional copies of correspondence, reports and
documents pertaining o compliance with the Prohibitions,
Specifications, and Provisions of this Order shall be
provided for public use when requested by the Executive
Officer.
11. The discharger shall permit the Regional 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, 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.
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Final Site Cleanup
. Requirements - Intel Santa Clara 3
Page 22
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.
12. The discharger shall file a report on any changes in site
occupancy and ownership associated with the facility
described in this Order.
13. If any hazardous substance 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 immediately report
such discharge to this Regional 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-office hours. A written report shall be filed
with the Regional Board within five working days and
shall contain information relative to: the nature of
waste or pollutant, quantity involved, duration of
incident, cause of spill, Spill Prevention and
Containment Plan (SPCC) in effect, if any, estimated size
of affected area, nature of effects, corrective measures
that have been taken or planned, and a schedule of these
activities, and persons notified.
14. The Regional Board will review this Order periodically
and may revise the requirements when necessary under the
criteria in Finding No. 17.
15. Regional Board Order No. 89-064 is hereby rescinded.
>'
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 July 18, 1990.
/ STEVEN R. RITCHIE
Executive Officer
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Final Site Cleanup
Requirements - Intel Santa Clara 3
Page 23
Attachments: Figure 1 Site Location Map - Intel Santa Clara 3.
Figure 2 Site Map of Intel Santa Clara 3 (showing
distribution of TCE in the A Water-Bearing
Zone, August 16, 1989).
Self-Monitoring Program for Intel Santa Clara 3.
Staff Report on the Final Remedial Action Plan for
the Intel Santa Clara 3 Site, dated March 30, 1990
and revised on June 19, 1990.
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SANTA CLARA 3
Figure lf site Location Map - Intel Santa Clara 3
-------
CENTRAL EXPRESSWAY
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I I
EXPLANATION
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concentration contour,
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SC3-SA
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SANTA CLARA 3
BUILDING
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Figure 2 Site Map of Intel Santa Clara 3 (showing distribution of TCE in the A Water-
Bearing Zone, August 16, 1989)
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RESPONSIVENESS SUMMARY
Intel Santa Clara 3
2880 Northwestern Parkway
Santa Clara
1.0 Introduction
This Responsiveness Summary is a compilation of comments received and responses
made by Regional Board staff regarding the proposed Remedial Action Plan (RAP)
for the Intel Santa Clara 3 (SC3) site.
Written comments have been received from the Santa Qara Valley Water District
(dated May 18, 1990) and EPA (dated May 10, 1990) regarding the Revised Tentative
Order. Intel has chosen to let their comments (dated April 10, 1990) on the original
March 30, 1990 Tentative Order serve as their comments on the April 9, 1990
Revised Tentative Order. A copy of all written comments is attached to the
Responsiveness Summary.
EPA's comments (dated May 10,1990) addressed methods used to calculate the
Carcinogenic Risk and Hazard Index associated with the cleanup standards for SC3.
Board staff concur with EPA's comments and have directly incorporated their
comments into the revised RAP. Thus no response to EPA's specific comments is
necessary in this Responsiveness Summary.
The initial Tentative Order (dated March 30, 1990) for SC3 was submitted to Intel
and EPA on March 30, 1990. On April 6, 1990, Intel met with Board staff to discuss
the Tentative Order. The March 30, 1990 Order was subsequently revised based on
verbal comments received by Board staff from EPA and Intel. The Revised
Tentative Order (dated April 9, 1990) was presented as an informational item to the
Regional Board at the Board's regular meeting on April 18, 1990. One of the
Board's actions at this meeting was to open the 30-day public comment period for
the RAP for SC3.
2.0 Local Community Issues
This section of the Responsiveness Summary is generally a summary of commentors'
major issues and concerns raised by the local community. However, as discussed
below, no major issues or concerns were raised by the local community. Therefore
this section summarizes the public meeting which took place on May 2, 1990 to
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Responsiveness Summary
Intel Santa Clara 3
June 19,1990 - Page 2
present and receive comments on the proposed RAP which was held in the Qty of
Santa Gara.
Despite an aggressive community relations program, which included publishing two
quarter-page newspaper advertisements and mailing over two hundred notices to
local residents, only two members of the public attended the meeting. During the
public meeting verbal comments were received from the Gty of Santa Clara Water
Utility and the two members of the public. Comments received at the public
meeting were addressed by Regional Board staff at the time of the meeting. The
transcript of the public meeting is included as an attachment to this Responsiveness
Summary.
During the public meeting questions were asked by the two members of the public
on the following general topics: 1) background on the Superfund process, 2) the
source of the groundwater pollution, 3) the pulsed pumping demonstration project,
4) the leak detection program in the Santa Clara Valley, 5) the nearby groundwater
pollution sites, 6) the municipal water supply system, and 7) the monitoring
frequency of the municipal supply groundwater wells.
No member of the public has requested modification of the proposed RAP for the
site. Therefore, no changes were made to the RAP as a result of public comment
A representative of the Gty of Santa Qara's Water Utility also commented on the
RAP at the public meeting. The Water Utility supported the RAP, however, they
also wanted the record to show that the current municipal water supply has not
been impacted by the groundwater pollution at SC3.
3.0 Specific Comments
This section addresses the specific written comments submitted by the Santa Qara
Water District and Intel on the proposed RAP.
3.1 General Comment (Santa Clara Valley Water District)
It is my understanding that the proposed cleanup goals of the shallow groundwater
specified for this site are to Maximum Contaminant Levels (MCL) or to California
Department of Health Services' action levels, whichever are more stringent The
District fully supports the cleanup of shallow groundwaters to at least these goals
with the understanding that further remediation requirements would be evaluated
based on feasibility and risk assessment evaluations.
-------
Responsiveness Summary
Intel Santa Clara 3
June 19, 1990 - Page 3
Response by RWOCB; The cleanup standards (also known as goals) are set at
California proposed or adopted MCLs. Board staff view these cleanup standards as
conservative. In cleaning up TCE to the 5 ppb cleanup standard, it is quite likely
that the concentration of the other chemicals will be reduced to below detection
levels. Therefore, the Regional Board will only require Intel to clean up the
groundwater beneath the site to those levels specified in the proposed RAP.
32 General Comment (Intel)
There was an extensive discussion regarding the inclusion of the Public Health
Evaluation (PHE). The report concludes that there is no current or future risk to
public health or the environment as a result of the current conditions which exist at
Inlel Santa Clara 3. Therefore, it is important that the RWQCB represent to the
public that there is no significant risk associated with this site. The justification for
establishing the cleanup goal of 5 ppb of TCE is based upon the fact that the
RWQCB established that the waters in the A-zone aquifer are a potential drinking
water source and, therefore, must be returned to this beneficial use. As a potential
drinking water source, the ARAR to establish a clean-up goal is the maximum
contaminant level (MCLs) which is 5 ppb for TCE.
Response by RWOCB: The role of the PHE is to access the current and future risk
at the site under a no-further-action scenario. Board staff is in agreement with Intel
that there is no current risk to the public with regard to the site because the
polluted shallow groundwater beneath the site is not currently being used as a
drinking water supply. However, Board staff disagrees with Intel relative to the
future risk. The potential future risks at the site under a no-further-action scenario
are: 1) a shallow private well could be installed if the site were redeveloped
residential and 2) the plume could hypothetically migrate to the lower aquifer zone
which is a current drinking water supply.
3.3 Finding 14 (Intel)
With regard to the Tentative Order, Finding 14, Intel suggests the following:
"Clean-up Goals - The selected remedy is designed to achieve the maximum
contaminant levels within the A-zone. As set forth in Section 121 of CERCLA, the
MCLs are protective of human health and the environment and fall within EPA's
acceptable carcinogenic risk range. The non-carcinogenic risk at this site is assessed
using the Hazard Index. If the Hazard Index is less than one, a combined intake of
-------
Responsiveness Summary
Intel Santa Clara 3
June 19,1990 - Page 4
chemicals is unlikely to propose a health risk.
The Hazard Index associated with the clean-up goals is 0.2. The methods and
assumptions used to obtain the Hazard Index associated with the cleanup goals are
contained in the March 30, 1990 staff report."
The carcinogenic risk calculations that are presented in the staff report are a
mathematical calculation, using either the drinking water standards or the action
levels. As discussed during the meeting, this calculation is not representative of
current or potential future site conditions and, therefore, the results should not be
contained in the Order.
Response by RWOCB;
Board staff have revised the Tentative Order to include the following statement in
Finding 16 (formerly Finding 14): The Carcinogenic Risk and Hazard Index
associated with the cleanup standards are based on a hypothetical scenario in which
the site is redeveloped residential and a private shallow drinking water well is
installed in the affected ground water. As such, the Carcinogenic Risk and Hazard
Index associated with the cleanup standards represent a maximum plausible risk.
For consistency, this scenario is being used in accessing the risk at all of the NPL
sites where the Regional Board is the lead agency."
3.4 Ending 12.b. (Intel)
It is Intel's intention to proceed as quickly as possible with the demonstration
project As discussed in our meeting, the new monitoring wells will be installed
between SC3-1 and SC3-7A. The new extraction well will not be installed until
after data is obtained and interpreted from the installation of the new monitoring
wells.
Although in theory, pulse pumping can have effects on removal of material in non-
saturated areas which are returned to saturation when pumping is ceased, the
particular situation in Santa Clara 3 does not lend itself physically to the theoretical
benefits of pulse pumping, due to the fact that the A-zone is confined and has not
become non-saturated due to pumping. As discussed in the meeting, there are
other benefits which would be examined through the demonstration project
Therefore, it is advantageous to increase the non-pumping time by two months
proceeding each cycle. In other words, two months of pumping, followed by two
months of shut-down, with the progression proceeding in the same manner. Intel
has agreed that we will monthly collect samples from SC3-9A and SC3-6 to insure
-------
Responsiveness Summary
Intel Santa Clara 3
June 19,1990 - Page 5
that there is no forward migration of the plume. It should be noted that during
the three years prior to pumping, there was no detectable forward migration of the
plume. During the five years of pumping, there has also been no detectable
forward migration of the plume. Intel predicts that the plume will remain
stationary. This is one of the primary reasons for implementing the cyclic pumping
scheme.
Response by RWOCB; Board staff will consider Intel's comments on the
Demonstration Project when staff reviews the "Proposal For a Demonstration
Project" for the site. Provision C2.a.l) of the Tentative Order requires submittal of
the proposal by July 31, 1990. It should be noted that Board staff has commented
on a number of these issues in a letter to Intel dated May 10, 1990 that addressed a
preliminary demonstration project proposal submitted by Intel on March 7, 1990.
35 Agency Addendum. Asymptotic Levels. (Intel)
It is apparent that Intel and the RWQCB have received different interpretations of
the asymptote information presented in the Stanford Report Weiss Associates will
proceed to schedule a technical meeting in late April or early May to review the
information among the RWQCB staff, Intel, Weiss Associates and L. Semprini of
Stanford.
Response by RWOCB: Board staff attended a meeting on this subject with Intel,
Weiss Associates and L. Semprini that took place on June 8, 1990. During the
meeting L. Semprini stated that the Stanford/Moffett NAS Field Site (NAS) and the
SC3 site have significant differences. Major differences between the NAS and the
SC3 site are 1) the aquifer material at the NAS site is more coarse grained, 2) the
initial concentration of the TCE was lower at the NAS site, and 3) the time between
the TCE release and cleanup was shorter at the NAS site. Based on this
information Board staff believe that a comparison of the asymptotic or tailing
conditions at the two sites should be viewed cautiously.
However, as shown on Figures 6 and 7 of the March 30, 1990 Staff Report (revised
June 19, 1990), asymptotic levels do not appear to have been conclusively reached in
all wells at SC3. With the installation of an additional extraction well and pulsed
pumping, TCE levels are likely to decrease.
-------
Responsiveness Summary
Intel Santa Clara 3
June 19, 1990 - Page 6
3.6 Finding 3. (Intel)
This finding should be retitled as "site chronology" and include both the 1982
request by the RWQCB for groundwater data and the Fall 1984 approval by the
Executive Officer for the interim clean-up plan, and implemented by Intel.
Response by RWOCB: Finding 3 has been modified as requested.
3.7 Finding 6. (Intel)
The issue of false positive from laboratory data regarding B-zone sampling was
discussed. It was agreed that the language used in the staff report would be
inserted into the discussion in the Tentative Order in Finding 6.
Response by RWOCB; Staff previously made this change to the Revised Tentative
Order (dated April 9, 1990). Therefore no further change is necessary.
3.8 Finding 12.a. (Intel)
Subparagraph A discusses that the groundwater extraction will continue until
drinking water quality is achieved, if feasible. The sentence following that one will
be deleted. The paragraph will continue on beginning with the sentence,
"Achieving drinking water quality if an ARAR ~."
Response by RWOCB; The sentence which Intel requested for deletion reads: "If
these (cleanup) standards are determined to be infeasible, groundwater extraction
shall continue as long as significant quantities of chemicals are being removed
through groundwater extraction". Board staff believes that this sentence should
remain in the Order. Otherwise, there is no incentive for Intel to aggressively work
toward reaching the cleanup standards.
3.9 Specification B.4. (Intel) -
In Specification 4, include a column in the table which presents the current site
concentrations.
Response by Regional Board; Staff previously made this change to the Revised
Tentative Order (dated April 9, 1990). Therefore, no further change is necessary.
-------
Responsiveness Summary
Intel Santa Clara 3
June 19, 1990 - Page 7
3.10 Specification B.5. (Intel)
Specification 5 will be moved to the Findings section of the Order.
Response by Regional Board; Staff previously made this change to the Revised
Tentative Order. Therefore, no further change is necessary. Specification 5 was
moved to the Findings section of the Tentative Order. The subject text is now
included in Finding 24 of the Revised Tentative Order (dated June 19, 1990).
3.11 Provision C5. (Intel)
The quarterly report will present appropriate tables and figures, based upon new
information which is generated since the previous quarterly report It will be the
annual report that contains an overall summary for the year. Therefore,
subparagraph c, d, e and f should be modified to reflect the fact that the quarterly
reports, will only present the new information, as opposed to being repetitive in
nature and continuing to present the same tables and figures each time.
Response by RWOCB; Provision C5.c. of the Tentative Order was modified such
that cross sections need to be included only if the interpretations have changed
since the previous quarter. The most current set of cross sections will continue to
be required in the annual report Subparagraphs C5.dv e. and f. refer to maps and
table showing the most recent groundwater and chemical data. This data is
required to be collected on a quarterly basis, so that it can be reported on a
quarterly basis. Board Staff need to use the results from the quarterly monitoring
reports to verify that 1) hydrologic control is maintained, 2) cleanup is proceeding
and, 3) no vertical or horizontal migration of the groundwater pollution is
occurring.
3.12 Self Monitoring Program E.4 (Intel)
Intel requests that this paragraph be modified to be consistent with CERCLA and
require a five year review process, as opposed to establishing a set 25 year
monitoring requirement The status of the site should be reviewed each five years
to determine whether any additional efforts are necessary, as opposed to pre-
establishing a 25 year monitoring requirement
-------
Responsiveness Summary
Intel Santa Clara 3
June 19, 1990 - Page 8
Response by RWOCB; A longterm monitoring program has been included in the
Self Monitoring Program (SMP) for the site. In an effort to make the SMP less
confusing, a table has been added (Table 3) which explains the four monitoring
phases. While it is unclear at this time whether 25 years is the exact length of time
needed for long term monitoring, Board staff believes that the language of the SMP
is general enough to provide the needed flexibility to the Executive Officer if a
shorter or longer term is necessary.
4.0 Responsiveness Summary Conclusion and Changes to the Propsed RAP
All verbal and written comments regarding changes to the proposed RAP have been
addressed. Board staff are not aware of any outstanding comments on the proposed
RAP. Based on this Responsiveness Summary, staff has not significantly changed
the Tentative Order.
-------
RESPONSIVENESS SUMMARY
Intel Santa Clara 3
2880 Northwestern Parkway
Santa Clara
1.0 Introduction
This Responsiveness Summary is a compilation of comments received and responses
made by Regional Board staff regarding the proposed Remedial Action Plan (RAP)
for the Intel Santa Clara 3 (SC3) site.
Written comments have been received from the Santa Clara Valley Water District
(dated May 18, 1990) and EPA (dated May 10, 1990) regarding the Revised Tentative
Order. Intel has chosen to let their comments (dated April 10, 1990) on the original
March 30, 1990 Tentative Order serve as their comments on the April 9, 1990
Revised Tentative Order. A copy of all written comments is attached to the
Responsiveness Summary.
EPA's comments (dated May 10, 1990) addressed methods used to calculate the
Carcinogenic Risk and Hazard Index associated with the cleanup standards for SC3.
Board staff concur with EPA's comments and have directly incorporated their
comments into the revised RAP. Thus no response to EPA's specific comments is
necessary in this Responsiveness Summary.
The initial Tentative Order (dated March 30, 1990) for SC3 was submitted to Intel
and EPA on March 30, 1990. On April 6, 1990, Intel met with Board staff to discuss
the Tentative Order. The March 30, 1990 Order was subsequently revised based on
verbal comments received by Board staff from EPA and Intel. The Revised
Tentative Order (dated April 9, 1990) was presented as an informational item to the
Regional Board at the Board's regular meeting on April 18, 1990. One of the
Board's actions at this meeting was to open the 30-day public comment period for
the RAP for SC3.
2.0 Local Community Issues
This section of the Responsiveness Summary is generally a summary of commentors'
major issues and concerns raised by the local community. However, as discussed
below, no major issues or concerns were raised by the local community. Therefore
this section summarizes the public meeting which took place on May 2, 1990 to
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Responsiveness Summary
Intel Santa Clara 3
June 19, 1990 - Page 2
present and receive comments on the proposed RAP which was held in the City of
Santa Clara.
Despite an aggressive community relations program, which included publishing two
quarter-page newspaper advertisements and mailing over two hundred notices to
local residents, only two members of the public attended the meeting. During the
public meeting verbal comments were received from the City of Santa Clara Water
Utility and the two members of the public. Comments received at the public
meeting were addressed by Regional Board staff at the time of the meeting. The
transcript of the public meeting is included as an attachment to this Responsiveness
Summary.
During the public meeting questions were asked by the two members of the public
on the following general topics: 1) background on the Superfund process, 2) the
source of the groundwater pollution, 3) the pulsed pumping demonstration project,
4) the leak detection program in the Santa Clara Valley, 5) the nearby groundwater
pollution sites, 6) the municipal water supply system, and 7) the monitoring
frequency of the municipal supply groundwater wells.
No member of the public has requested modification of the proposed RAP for the
site. Therefore, no changes were made to the RAP as a result of public comment.
A representative of the City of Santa Clara's Water Utility also commented on the
RAP at the public meeting. The Water Utility supported the RAP, however, they
also wanted the record to show that the current municipal water supply has not
been impacted by the groundwater pollution at SC3.
3.0 Specific Comments
This section addresses the specific written comments submitted by the Santa Clara
Water District and Intel on the proposed RAP.
3.1 General Comment (Santa Clara Valley Water District)
It is my understanding that the proposed cleanup goals of the shallow groundwater
specified for this site are to Maximum Contaminant Levels (MGL) or to California
Department of Health Services' action levels, whichever are more stringent The
District fully supports the cleanup of shallow groundwaters to at least these goals
with the understanding that further remediation requirements would be evaluated
based on feasibility and risk assessment evaluations.
-------
' Responsiveness Summary
Intel Santa Clara 3
June 19, 1990 - Page 3
Response by RWQCB; The cleanup standards (also known as goals) are set at
California proposed or adopted MCLs. Board staff view these cleanup standards as
conservative. In cleaning up TCE to the 5 ppb cleanup standard, it is quite likely
that the concentration of the other chemicals will be reduced to below detection
levels. Therefore, the Regional Board will only require Intel to clean up the
groundwater beneath the site to those levels specified in the proposed RAP.
3.2 General Comment (Intel)
There was an extensive discussion regarding the inclusion of the Public Health
Evaluation (PHE). The report concludes that there is no current or future risk to
public health or the environment as a result of the current conditions which exist at
Intel Santa Clara 3. Therefore, it is important that the RWQCB represent to the
public that there is no significant risk associated with this site. The justification for
establishing the cleanup goal of 5 ppb of TCE is based upon the fact that the
RWQCB established that the waters in the A-zone aquifer are a potential drinking
water source and, therefore, must be returned to this beneficial use. As a potential
drinking water source, the ARAR to establish a clean-up goal is the maximum
contaminant level (MCLs) which is 5 ppb for TCE.
Response by RWOCB: The role of the PHE is to access the current and future risk
at the site under a no-further-action scenario. Board staff is in agreement with Intel
that there is no current risk to the public with regard to the site because the
polluted shallow groundwater beneath the site is not currently being used as a
drinking water supply. However, Board staff disagrees with Intel relative to the
future risk. The potential future risks at the site under a no-further-action scenario
are: 1) a shallow private well could be installed if the site were redeveloped
residential and 2) the plume could hypothetically migrate to the lower aquifer zone
which is a current drinking water supply.
3.3 Finding 14 (Intel)
With regard to the Tentative Order, Finding 14, Intel suggests the following:
"Clean-up Goals - The selected remedy is designed to achieve the maximum
contaminant levels within the A-zone. As set forth in Section 121 of CERCLA, the
MCLs are protective of human health and the environment and fall within EPA's
acceptable carcinogenic risk range. The non-carcinogenic risk at this sife is assessed
using the Hazard Index. If the Hazard Index is less than one, a combined intake of
-------
Responsiveness Summary
Intel Santa Clara 3
June 19, 1990 - Page 4
chemicals is unlikely to propose a health risk.
The Hazard Index associated with the clean-up goals is 0.2. The methods and
assumptions used to obtain the Hazard Index associated with the cleanup goals are
contained in the March 30, 1990 staff report"
The carcinogenic .risk calculations that are presented in the staff report are a
mathematical calculation, using either the drinking water standards or the action
levels. As discussed during the meeting, this calculation is not representative of
current or potential future site conditions and, therefore, the results should not be
contained in the Order.
Response by RWOCB:
Board staff have revised the Tentative Order to include the following statement in
Finding 16 (formerly Finding 14): "The Carcinogenic Risk and Hazard Index
associated with the cleanup standards are based on a hypothetical scenario in which
the site is redeveloped residential and a private shallow drinking water well is
installed in the affected groundwater. As such, the Carcinogenic Risk and Hazard
Index associated with the cleanup standards represent a maximum plausible risk.
For consistency, this scenario is being used in accessing the risk at all of the NPL
sites where the Regional Board is the lead agency."
3.4 Finding 12.b. (Intel)
It is Intel's intention to proceed as quickly as possible with the demonstration
project As discussed in our meeting, the new monitoring wells will be installed
between SC3-1 and SC3-7A. The new extraction well will not be installed until
after data is obtained and interpreted from the installation of the new monitoring
wells.
Although in theory, pulse pumping can have effects on removal of material in non-
saturated areas which are returned to saturation when pumping is ceased, the
particular situation in Santa Clara 3 does not lend itself physically to the theoretical
benefits of pulse pumping, due to the fact that the A-zone is confined and has not
become non-saturated due to pumping. As discussed in the meeting, there are
other benefits which would be examined through the demonstration project
Therefore, it is advantageous to increase the non-pumping time by two months
proceeding each cycle. In other words, two months of pumping, followed by two
months of shut-down, with the progression proceeding in the same manner. Intel
has agreed that we will monthly collect samples from SC3-9A and SC3-6 to insure
-------
Responsiveness Summary
Intel Santa Clara 3
June 19, 1990 - Page 5
that there is no forward migration of the plume. It should be noted that during
the three years prior to pumping, there was no detectable forward migration of the
plume. During the five years of pumping, there has also been no detectable
forward migration of the plume. Intel predicts that the plume will remain
stationary. This is one of the primary reasons for implementing the cyclic pumping
scheme.
Response by RWOCB; Board staff will consider Intel's comments on the
Demonstration Project when staff reviews the "Proposal For a Demonstration
Project" for the site. Provision C.2.a.l) of the Tentative Order requires submittal of
the proposal by July 31, 1990. It should be noted that Board staff has commented
on a number of these issues in a letter to Intel dated May 10, 1990 that addressed a
preliminary demonstration project proposal submitted by Intel on March 7, 1990.
35 Agency Addendum, Asymptotic Levels. (Intel)
It is apparent that Intel and the RWQCB have received different interpretations of
the asymptote information presented in the Stanford Report Weiss Associates will
proceed to schedule a technical meeting in late April or early May to review the
information among the RWQCB staff, Intel, Weiss Associates and L. Semprini of
Stanford.
Response by RWOCB: Board staff attended a meeting on this subject with Intel,
Weiss Associates and L. Semprini that took place on June 8, 1990. During the
meeting L. Semprini stated that the Stanford/Moffett NAS Field Site (NAS) and the
SC3 site have significant differences. Major differences between the NAS and the
SC3 site are 1) the aquifer material at the NAS site is more coarse grained, 2) the
initial concentration of the TCE was lower at the NAS site, and 3) the time between
the TCE release and cleanup was shorter at the NAS site. Based on this
information Board staff believe that a comparison of the asymptotic or tailing
conditions at the two sites should be viewed cautiously.
However, as shown on Figures 6 and 7 of the March 30, 1990 Staff Report (revised
June 19, 1990), asymptotic levels do not appear to have been conclusively reached in
all wells at SC3. With the installation of an additional extraction well and pulsed
pumping, TCE levels are likely to decrease.
-------
Responsiveness Summary
Intel Santa Clara 3
June 19, 1990 - Page 6
3.6 Finding 3. (Intel)
This finding should be retitled as "site chronology" and include both the 1982
request by the RWQCB for groundwater data and the Fall 1984 approval by the
Executive Officer for the interim clean-up plan, and implemented by Intel.
Response by RWOCB; Finding 3 has been modified as requested.
3.7 Finding 6. (Intel)
The issue of false positive from laboratory data regarding B-zone sampling was
discussed. It was agreed that the language used in the staff report would be
inserted into the discussion in the Tentative Order in Finding 6.
Response by RWOCB: Staff previously made this change to the Revised Tentative
Order (dated April 9, 1990). Therefore no further change is necessary.
3.8 Finding 12.a. (Intel)
Subparagraph A discusses that the groundwater extraction will continue until
drinking water quality is achieved, if feasible. The sentence following that one will
be deleted. The paragraph will continue on beginning with the sentence,
"Achieving drinking water quality if an ARAR ..."
Response by RWOCB; The sentence which Intel requested for deletion reads: "If
these (cleanup) standards are determined to be infeasible, groundwater extraction
shall continue as long as significant quantities of chemicals are being removed
through groundwater extraction". Board staff believes that this sentence should
remain in the Order. Otherwise, there is no incentive for Intel to aggressively work
toward reaching the cleanup standards.
3.9 Specification B.4. (Intel)
In Specification 4, include a column in the table which presents the current site
concentrations.
Response by Regional Board; Staff previously made this change to the Revised
Tentative Order (dated April 9, 1990). Therefore, no further change is necessary.
-------
Responsiveness Summary
Intel Santa Clara 3
June 19, 1990-Page 7
3JO Specification B.5. (Intel)
Specification 5 will be moved to the Findings section of the Order.
Response by Regional Board; Staff previously made this change to the Revised
Tentative Order. Therefore, no further change is necessary. Specification 5 was
moved to the Findings section of the Tentative Order. The subject text is now
included in Finding 24 of the Revised Tentative Order (dated June 19, 1990).
3.11 Provision C.5. (Intel)
The quarterly report will present appropriate tables and figures, based upon new
information which is generated since the previous quarterly report It will be the
annual report that contains an overall summary for the year. Therefore,
subparagraph c, d, e and f should be modified to reflect the fact that the quarterly
reports will only present the new information, as opposed to being repetitive in
nature and continuing to present the same tables and figures each time.
Response by RWOCB; Provision G5.c. of the Tentative Order was modified such
that cross sections need to be included only if the interpretations have changed
since the previous quarter. The most current set of cross sections will continue to
be required in the annual report. Subparagraphs C5.d., e. and f. refer to maps and
table showing the most recent groundwater and chemical data. This data is
required to be collected on a quarterly basis, so that it can be reported on a
quarterly basis. Board Staff need to use the results from the quarterly monitoring
reports to verify that: 1) hydrologic control is maintained, 2) cleanup is proceeding
and, 3) no vertical or horizontal migration of the groundwater pollution is
occurring.
3.12 Self Monitoring Program E.4 (Intel)
Intel requests that this paragraph be modified to be consistent with CERCLA and
require a five year review process, as opposed to establishing a set 25 year
monitoring requirement The status of the site should be reviewed each five years
to determine whether any additional efforts are necessary, as opposed to pre-
establishing a 25 year monitoring requirement
-------
Responsiveness Summary
Intel Santa Clara 3
June 19, 1990 - Page 8
Response by RWOCB: A longterm monitoring program has been included in the
Self Monitoring Program (SMP) for the site. In an effort to make the SMP less
confusing, a table has been added (Table 3) which explains the four monitoring
phases. While it is unclear at this time whether 25 years is the exact length of time
needed for long term monitoring, Board staff believes that the language of the SMP
is general enough to provide the needed flexibility to the Executive Officer if a
shorter or longer term is necessary.
4.0 Responsiveness Summary Conclusion and Changes to the Propsed RAP
All verbal and written comments regarding changes to the proposed RAP have been
addressed. Board staff are not aware of any outstanding comments on the proposed
RAP. Based on this Responsiveness Summary, staff has not significantly changed
the Tentative Order.
-------
Santa Clara Valley Water District
5750 ALMADEN EXPRESSWAY
SAN JOSE, CALIFORNIA 95118
TELEPHONE (408)265-2600
FACSIMILE .(408)266-0271
AN AFFIRMATIVE ACTION EMPLOYER
May 18, 1990
WA7B?
MAY £ 2 1990
QUALITY CONTROL
Mr. Gregory Bartow
Regional Water Quality Control Board
1800 Harrison, Suite 700
Oakland, CA 94612
Dear Mr. Bartow:
Subject: Comments on Tentative Order, Proposed Remedial Action Plan and Site Cleanup
Requirements for Intel Corporation, Santa Clara 3 Facility
This letter presents our comments on the above subject site located at 2800 Northwestern Parkway.
It is my understanding that the proposed cleanup goals of the shallow groundwater specified for this site
are to Maximum Contaminant Levels (MCL) or to California Department of Health Services' action
levels, whichever are more stringent. The District fully supports the cleanup of shallow groundwaters
at least to these goals with the understanding that further remediation requirements would be evaluated
based on feasibility and risk assessment evaluations.
We are also in concurrence with the proposal to make efforts to reuse treated waters and with other water
conservation practices specified in the order.
Please call Tom Iwamura should you have any questions.
avid J. Chesfe
Division Engineer
Groundwater Protection Division
-------
OS. IB. GO .001
r
R S *C O T 4 8 O 8 T FO2
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REOONtt
1236 Mlwton fttr*«t
Sen Ptenelsco, Ca. 94103
Memorandum
May 10,1990
From: Sharon Seldel
Regional Toxlcologlst (H-8-4)
To: Rose Marie Caraway
Project Manager (H-6-3)
Subject: Intel Santa Clare HI risk calculations
Jid
I reviewed the risk estimates In the RWQCB "Executive Officer Summary
Report" on Intel Santa Clara III. There are some errors in the calculations,
which when corrected increase the final cancer risk estimate to 1.3E-4, from
9.2E-5. The non-carcinogenic hazard Index has minor changes which revise it
downwards The corrections in the calculations are as follows:
1. 1,1-DIchioroethane (1,1-DCA) fs listed only in the non-carcinogen table in
the report. 1,1 -DCA Is classified as a B2 carcinogen, with an oral CPF of 9.1 E-2
(mg/kg/day)'1, and should be Included In the carcinogen portion of the risk
assessment.
2. Cancer risks associated with the inhalation of VOCs during domestic uses of
water, such as showering, should be assessed using Inhalation cancer potency
factors, where available. Route-to-route extrapolation of oral cancer potency
factors for inhalation exposures Is less preferable but may be substituted for the
VOCs of concern when inhalation cancer potency factors are not available. The
assumption in this model is that the dosa from the inhalation of VOCs Is
approximately equal to that from drinking 2 liters of the same water. The
following VOCs have Inhalation cancer potency factors listed in IRIS or HEAST:
1,2-DCA 0.091 (mg/kg/day)-1 (. oral CPF, no change In risk *)
1,1-DCE 1.20(mg/kg/day)'1
TCE 0.017 (mg/kg/day)-1
3. The oral cancer potency factor for TCE Is Incorrectly listed as 0.11 and
should be corrected to 0.011 (mg/kg/day)'1.
-------
OS. IB. SO. O Q : 1 1 .A.M * « P A R Q. OK K V4*B f * O 2 T P O 3
Recalculated risks for the inhalation pathway:
Chemfpal
1,1-DCA
1,2-DCA
1,1-DCE
TCP
Cw
0.005
0.0005
0.006
0.005
CPF
0.091*
0.091
1.20
0.017
CD1
5.50E-5
5.50E-6
6.60E-5
S SOF-S
Inhalation Risk
5.01 E-6
5.01 E-7
7.92E-5
9.35F.-7
OralCPF;NolnhalCPFava!iaWt 8.56E-5
Recalculated risks for the drinking water pathway:
Chemical Cw CPP GDI QraLBisk
1,1-DCA
1,2-DCA
1,1-DCE
TCE
0.005
0.0005
0.006
0.005
0.091
0.091
0.6
0.011
5.50E-5
5.50E-6
6.60E-5
6.50F.-S
5.01 E-6
5.01 E-7
3.96E-5
6.05E-7
4.57E-5
Total cancer risk: 8.56E-5 4 4.57E-5 « 1.31E-4
4. The inhalation risks for non-carcinogens should be similarly assessed using
inhalation RfDs, where available. The following VOCs have Inhalation RfDs:
1,1 -DCA 0.1 mg/kg/day (- oral RID, no change in risk #)
Freon11 0.2mg/kg/day
1,1,1-TCA 0.3mg/kg/day
The recalculated inhalation Hazard index is 7.56E-2. The total Hazard Index is
1.92E-1, a minor reduction from the original total HI of 2.32E-1.
If you have any questions or concerns about these calculations I can be
reached at (415) 540-3771.
cc: Jim Hanson
Doug Steele
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INTEL CORPORATION
2402 W. Beardsley Road
Phoenix. Arizona 85027
(602)669-3805
^AllPORNIA REGIONAL WATR
APR 13J990
QUALITY CONTROL BOARD
April 10, 1990
Gregory Bartow,
California Regional Water duality Control Board
San Francisco Bay Region
1800 Harrison Street, Suite 700
Oakland, CA 94612
SUBJECT: MEETING OF APRIL 6. 1990
Dear Greg:
Intel Corporation (Intel) appreciated the opportunity to meet with Bruce
Wolfe, James Thompson and you on April 6 to review the RWQCB letter of March
29 and the draft Tentative Order dated March 30, 1990. A number of items
were discussed during the course of our meeting. The following summarizes
several of the key Issues and areas of agreement.
PUBLIC HEALTH EVALUATION
There was an extensive discussion regarding the inclusions of the Public
Health Evaluation. The report concludes that there is no current or future
risk to public health or the environment as a result of the current
conditions which exist at Intel^Santa Clara 3. Therefore, it is important
that the RWQCB represent to the public that there is no significant risk
associated with this site. The Justification for establishing the clean-
up goal of 5 ppb of TCE is based upon the fact that the RWQCB established
that the waters 1n the A-zone aquifer are a potential drinking water source
and, therefore, must be returned to this beneficial use. As a potential
drinking water source, the ARAR to establish a clean-up goal is the maximum
contaminant level (MCLs) which is 5 ppb for TCE.
With regard to the Tentative Order, Finding 14, Intel suggests the following:
"Clean-up Coals - The selected remedy is designed to achieve the maximum
contaminant levels within the A-zone. As set forth in Section 121 of CERCLA,
the MCLs are protective of human health and the environment and fall within
EPA's acceptable carcinogenic risk range. The non-carcinogenic risk at this
site is assessed using the Hazard Index. If the Hazard Index is less than
one, a combined Intake of chemicals 1s unlikely to propose a health risk.
The Hazard Index associated with the clean-up goals is 0.2. The methods
and assumptions used to obtain the Hazard Index associated with the clean-
up goals are contained in the March 30, 1990 staff report."
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Gregory Bartow
April 10, 1990
Page Two
FINDING 14. AS PROPOSED. REFERENCES
The carcinogenic risk calculations that are presented 1n the staff report as
a mathematical calculation, using either the drinking water standards or
the action levels. As discussed during the meeting, this calculation Is
not representative of current or potential future site conditions and,
therefore, the results should not be contained 1n the Order.
DEMONSTRATION PROJECT
It 1s Intel's Intention to proceed as quickly as possible with the
demonstration project. As discussed 1n our meeting, the new monitoring wells
will be Installed between SC3-1 and SC3-7A. The new extraction well will not
be Installed until after data Is obtained and Interpreted from the
installation of the new monitoring wells.
Although 1n theory, pulse pumping can have effects on removal of material in
non-saturated areas which are returned to saturation when pumping 1s ceased,
the particular situation In Santa Clara 3 does not lend Itself physically to
the theoretical benefits of pulse pumping, due to the fact that the A-zone
1s confined and has not become non-saturated due to pumping. As discussed
In the meeting, there are other benefits which would be examined through the
demonstration project. Therefore, It Is advantageous to Increase the non-
pumping time by two months proceeding each cycle. In other words, two months
of pumping, followed by two months of shut-down, followed by two months of
pumping, followed by four months of shut-down, with the progression
proceeding In the same manner. Intel has agreed that we will monthly collect
samples from SC9A and SC6 to Insure that there Is no forward migration of the
plume. It should be noted that during the three years prior to pumping,
there was no detectable forward migration of the plume. During the five
years of pumping, there has also been no detectable forward migration of the
plume. Intel predicts that the plume will remain stationary. This 1s one
of the primary reasons for Implementing the cyclic pumping scheme.
Either Mary Stallard or Bill Hcllvride of Weiss Associates will contact you
In the next couple of weeks to receive your comments on the draft
demonstration project proposal. Weiss Associates will modify the
demonstration project and resubmlt the proposal to you by Hay 4, 1990. The
demonstration project will also contain Information regarding the
Installation of the two new monitoring wells.
INTERPRETATION OF ASYMPTOTES FROM STANFORD DATA
»
It Is apparent that Intel and the RWQCB have received different
Interpretations of the .asymptote Information presented In the Stanford
Report. Weiss Associates will proceed to schedule a technical meeting in
late April or early Kay to review the information among the RWQCB staff,
Intel, Weiss Associates and L. Semprini of Stanford.
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Gregory Bartow
April 10, 1990
Page Three
RESPONSE TO HARCH 29 LETTER
Weiss Associates will prepare a response to the RUQCB letter of March 29.
This response will be on behalf of Intel and submitted on April 12, 1990.
Weiss Associates has been requested to make a mathematical projection of the
time to clean-up. This projection will be based upon theoretical
considerations and associated assumptions to project a time for clean-up.
Intel requests that these results be used and communicated to the Board and
the public as non-field substantiated, theoretical assumptions.
TENTATIVE ORDER. FINDING 3
This finding should be ret1tied as "site chronology" and Include both the
1982 request by the RWQCB for groundwater data and the Fall 1984 approval by
the Executive Officer for the Interim clean-up plan, and Implemented by
Intel.
TENTATIVE ORDER. FINDING 6
The Issue of false positives from laboratory data regarding B-zone samplings
was discussed. It was agreed that the language used 1n the staff report
would be Inserted Into the discussion In the Tentative Order In Finding 6.
TENTATIVE ORDER. FINDING 12
Subparagraph A discusses that the groundwater extraction will continue until
drinking water quality Is achieved, If feasible. The sentence following that
one will be deleted. The paragraph will continue on beginning with the
sentence, "Achieving drinking water quality If an ARAR..."
TENTATIVE ORDER - SPECIFICATIONS
In Specification 4, Include a column 1n the table which presents the
current site concentrations.
Specification 5 will be moved to the Findings section of the Order. ,
TENTATIVE ORDER - PROVISIONS C.S
The quarterly report will present appropriate tables and figures, based upon
new Information which Is generated since the previous quarterly report. It
will be the annual report that contains an overall summary for the year.
Therefore, Subparagraph c, d, e and f should be modified to reflect the fact
that the quarterly reports will only present the new Information, as opposed
to being repetitive 1n nature and continuing to present the same tables and
figures each time.
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Gregory Bartow
April 10, 1990
Page Four
TENTATIVE SELF-MONITORING PROGRAM SECTION E. PARAGRAPH 4
Intel requests that this paragraph be modified to be consistent with CERCLA
and require a five year review process, as opposed to establishing a set 25
year monitoring requirement. The status of the site should be reviewed
each five years to determine whether any additional efforts are necessary,
as opposed to pre-establishing a 25 year monitoring requirement.
Intel appreciates the opportunity to meet with the RUQCB and discuss this
proposed Order. It Is our understanding that this Order will be presented
at the April 18, 1990 Board meeting. At this time, the Order will be open
for a 30-day public comment period.
If you would like to discuss or have any questions regarding the Information
contained in this letter, please feel free to contact either John Master-man
at (916) 351-5529 or me at (602) 869-4812.
Sincerely,
Terrence J. McManus, P.E.
Manager, Corporate Environmental, Health and Safety
CC: Bruce Wolfe
Jim Thompson >
Mary Stallard
Bryan Rector
Bill KdlvHde
John Hasterman
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