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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                                                          Staff Report - Page 2
                                                          March 30, 1990
                                                          Revised June 19, 1990

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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                                                          Staff Report - Page 3
                                                          March 30, 1990
                                                          Revised June 19,1990

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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                                                      Staff Report - Page 4
                                                      March 30, 1990
                                                      Revised June 19,1990
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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                                                          Staff Report - Page 5
                                                          March 30, 1990
                                                          Revised June 19,1990
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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                                                         Staff Report - Page 6
                                                         March 30, 1990
                                                         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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                                                           Staff Report - Page 7
                                                           March 30, 1990
                                                           Revised June 19, 1990

 (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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                                                          Staff Report - Page 8
                                                          March 30, 1990
                                                          Revised June 19, 1990

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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                                                          Staff Report - Page 9
                                                          March 30, 1990
                                                          Revised June 19, 1990


 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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                                                           Staff Report - Page 10
                                                           March 30, 1990
                                                           Revised June 19,1990

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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                                                         Staff Report - Page 11
                                                         March 30, 1990
                                                         Revised June 19, 1990

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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                                                          Staff Report - Page 12
                                                          March 30, 1990
                                                          Revised June 19, 1990
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

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                                                         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)

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                                 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

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                               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

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                                  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.

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  u
  u
    280-
    240-
    200-
    16O-
    120
     80
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                                              o   —
8888SSSSS
•^'•s.'x^'s.^.^.^'s.

       »
                                                                00  O
                                                DATE
Figure 7.    Concentration of TCE vs. Tine  Detected in Monitoring Well  SC3-7A

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      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)

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                                        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

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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

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     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  -

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 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

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                                                  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.

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                                                     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

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                                   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:

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                                                       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

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                                                          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.

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                                  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

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                                             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:

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                                   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

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                              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

-------
                                        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

-------
                                        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

-------
                                        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.

-------
«Q
C
(D
01
9
0

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M
0

3

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I
0
•0
                                  CENTRAL
                                     EXPRESSWAY
                                                ISC3-9A
                        SC3MOA
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       N
                                8C3-8A
                     •    M    no   -wort
                          0  .

                           5=
                    0
                                 SC3-CT
                                                        8C3-2
                                        ditttl
                                        lank
INTEL SANTA CLARA  J

      BUILDING


      65,000 II*
    COMtntdttf 1976
                                                                 SC4-I
                                       tankD
                                     INTEL SANTA CLARA 4  BLDG.
!
                                 5

                                 1
                                 X

-------
                           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

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                                  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

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     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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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

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     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.

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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

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     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

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     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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     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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     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
                                   Requirements  -  Intel Santa Clara 3
                                   Page 14
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
                         Requirements - Intel Santa Clara 3
                         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
                         Requirements - Intel  Santa  Clara 3
                         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
                         Requirements - Intel Santa Clara  3
                         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
                         Requirements - Intel Santa  Clara  3
                         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
                         Requirements - Intel Santa Clara 3
                         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
N
t i
o
i_
50   100 ft.
I	I
                                                                         EXPLANATION
                                                                    • 0.659  TCE concentration (ppm)
                                                                             concentration contour,
                                                                             ). dashed whore inferred
                     tO.0001  /    ^.SC3-
                     5C3-10A  f
                 o
                  J
                       0.0007
                       SC3-SA
                                ||X SC3-7

                           \x
                               *^,^ s>fer*-x"
                                II l/"l*»sca.ci — ^n     >**^
                           o
         <0 0002

JL  c^^
^J
                            SANTA CLARA 3
                            BUILDING
                                                Qtflcirtunk _
U
                                                    .SC4-1
                                             dXtctUnkD
                               /A/TEL S^NLA CL>»f?>\ 4

                                    BUILDING
                                                          D


                                                          O
                                  a


                                  D
                            a

                            a
                                                                              0
                                       I
                                       5
                                       I
                                       0)
                                       1
                                                    2
                                                    33
                                                                                  S
                                                                                  •<
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.

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                                                      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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