Regional Groundwater Remediation Program Middlefield-Ellis ... · SFD-7-3 EPA Region IX 75...

SFUND RECORDS CTR

2060200

Report

Five Year Performance ReviewRegional Groundwater Remediation ProgramMiddlefield-Ellis-Whisman SiteMountain View, California

Prepared for:

Fairchild Semiconductor CorporationRaytheon Company

17 December 2003

Project No. 23007-04-2500

Locus

UNSCANNABLE MEDIA2070962

To use the unscannable media document(s),contact the Region IX Superfund Records Center

in San Francisco at 415-536-2000.

Unscannable media - parent

Locus 299 Fairchild DriveMountain View, California 94043Tel: 650-960-1640Fax: 650-960-0739http://-wwwlocustec.com

17 December 2003

Ms Alana LeeProject ManagerSFD-7-3EPA Region IX75 Hawthorne StreetSan Francisco, CA 94102

RE: Response to EPA Information Request for Five-Year Review, Regional GroundwaterRemediation Program, Middlefield-Ellis-Whisman Area, Mountain View, CALocus Project No. 23007-04-2500

Dear Ms. Lee:

Please find enclosed our report providing the remainder of information that you requested on 10October 2003 in support of EPA Region IX's five-year performance review for the RegionalGroundwater Remediation Program (RGRP) at the Middlefield-Ellis-Whisman Site in MountainView, California. This report supplements the data submitted to you on 8 December 2003. Table1-1 of the enclosed report provides references to where the information specified in EPA's 10October 2003 letter can be found on the enclosed CD ROM. Because the RGRP has elected toprovide the optional information and evaluation identified in the 10 October 2003 letter, we haveprepared the enclosed report in the format for a five-year review specified in EPA's current five-year review guidance document.

Should you have questions, please call,

icerely,

Vice President

EHH/mrnm

Enclosures

11 \23-007 FAIRCHILDWY - REG1ONAULEE - 5Y RGRP 17DEC03 DOC

Ms. Alana Lee 2 17 December 2003

Distribution List

Gordon Atkinson, Cooley Godward, LLPIndira Balksissoon, TechLawJack Benton, SUMCOJames E. Boarer, Locus TechnologiesDon Chuck, NASA-Ames Research CenterTom Cooper, Intel CorporationJohn Elliot, Weiss AssociatesAndrea Espinoza, U.S. Department of the NavySusan Gahry, PES EnvironmentalMaria Pilar Ho ye, Esq.; Latham & WatkinsMichael Kierig; NEC Electronics America, Inc.Clifford E. Kirchof, Schlumberger Ltd.Carolyn Kneiblher, GeoSyntec, Corp.Brian Maidrand, Foster Wheeler Environmental CorporationMEW Repository (2 copies)Mountain View LibrarySandy Olliges, NASA-Ames Research CenterHollis Phillips, URSHarold Rush, Geomatrix Consultants, hie.Greg Taylor, Raytheon CompanyThomas D. Trapp, Esq.; Barg Coffin Lewis & Trapp, LLP

I M \23-007 FAIRCHILDV5Y - REGIONAULEE - 5Y RGRP 17DEC03 DOC '

Locus

Five Year Performance Review

Regional Groundwater Remediation ProgramMiddlefield-Ellis-Whisman SiteMountain View, California

ecus1333 N.California Blvd.Suite 540Walnut Creek, CA 94596Tel: 925.906.8100Fax: 925.906.8101

299 Fairchild DriveMountain View, CA 94043Tel: 650.960.1640Fax: 650.960.0739

2101 Arena BoulevardSuite 220Sacramento, CA 95834Tel: 916.679.2600Fax: 916.679.2601

TABLE OF CONTENTS

LIST OF TABLES inLIST OF FIGURES '. ivLIST OF APPENDICES vLIST OF ACRONYMS viEXECUTIVE SUMMARY viii

1. INTRODUCTION 1

2. CHRONOLOGY OF EVENTS 3

3. BACKGROUND 63.1. Physical Characteristics 63.2. Land and Resource Use 63.3. History of Environmental Investigation and Remediation 73.4. Initial Remedial Actions 83.5. Basis for Taking Action 8

4. REMEDIAL ACTIONS 94.1. Remedy Implementation. 9

4.1.1. Remedial Measures Implemented by the MEW Companies 104.1.1.1 Fairchild Semiconductor Corporation 104.1.1.2 Vishay General Semiconductor, Inc. and Sumitomo

Mitsubishi Silicon America 124.1.1.3 Intel Corporation/Raytheon Company 124.1.1.4 Raytheon Company. 134.1.1.5 NEC Electronics, Inc 134.1.1.6 Sobrato Development Company 13

4.1.2. Remedial Programs Implemented by the RGRP 144.1.3. Potential Conduits Program 144.1.4. Plume Definition Program 14

4.1.4.1 Groundwater Remediation by RGRP Program South ofU.S. Highway 101 15

4.1.4.2 Groundwater Remediation by RGRP Program North ofU.S. Highway 101 16

4.1.5. Remedial Measures Implemented by Others 174.1.6. Air 17

4.1.6.1 Types of Samples 184.1.6.2 Sampling Procedures 18

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4.1.6.3 Evaluation Methodology. 194.1.6.4 Sampling Results 19

4.2. System Operation/Operation & Maintenance 204.2.1. RGRP Treatment System South of Hwy. 101 20

• 4.2.2. RGRP Treatment System North of Hwy. 101 214.2.3. O&M Costs 22

5. PROGRESS SINCE THE LAST FIVE-YEAR REVIEW 23

6. FIVE-YEAR REVIEW PROCESS 246.1. Community Involvement 246.2. Document Review. 246.3. Data Review 25

6.3.1. Are Proper Capture Zones Obtained? 256.3.1.1 15 January 1998 266.3.1.2 26 February 1998 276.3.1.3 28 May 1998 286.3.1.4 27 August 1998 296.3.1.5 19 November 1998 296.3.1.6 25 February 1999 306.3.1.7 27 May 1999 306.3.1.8 18 November 1999 316.3.1.9 25 May 2000 316.3.1.10 16 November 2000 326.3.1.11 24 May 2001 326.3.1.12 15 November 2001 326.3.1.13 23 May 2002 336.3.1.14 21 November 2002 336.3.1.15 Summary 33

6.3.2. Are Vertical Gradients Appropriate? 346.3.2.1 "A/Bl"Aquitard 346.3.2.2 "Bl/B2"Aquitard 346.3.2.3 "B2/B3" Aquitard 356.3.2.4 "B/C" Aquitard 35

6.3.3. Are the boundaries ofthe MEW plume stable or shrinking? 356.3.3.1 "A" Aquifer 356.3.3.2 "Bl" Aquifer 366.3.3.3 "B2" Aquifer 366.3.3.4 "B3" Aquifer 376.3.3.5 "C" and Deep Aquifer 37

6.3.4. Are the Overall Trends in Concentrations Decreasing? 376.3.5. Is the dissolved mass of TCE decreasing? 41

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6.3.6. Summary of Data Review 466.3.7. Interviews 46

7. TECHNICAL ASSESSMENT 477.1. " Question A: Is the Remedy Functioning as Intended by the Decision

Document? 477.2. Question B: Are the Exposure Assumptions, Toxicity Data, Cleanup Levels,

and Remedial Action Objectives (RAOs) Used at the Time of RemedySelection Still Valid? 487.2.1. Changes in Standards To Be Considered 487.2.2. Changes in Exposure Pathways, Toxicity, and Other Contaminant

Characteristics 497.3. Question C: Has any Other Information Come to Light that Could Call into

Question the Protectiveness of the Remedy? 507.4. Summary of Technical Assessment 50

8. ISSUES 51

9. RECOMMENDATIONS AND FOLLOW UP ACTIONS 52

10. PROTECTIVENESS STATEMENT 53

11. NEXT REVIEW 54

12. REFERENCES 55

TABLESFIGURESAPPENDICES

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LIST OF TABLES

TABLENO.

1-13-1

3-2

3-3

4-1

4-2

4-3

4-4

4-5

6-1

6-2

TITLE

Check List for EPA's Request for Information - Five Year Report

Aquifer Test Results

Monitoring Well Details

List of Sealed Monitoring Wells

Actions Taken to Address Potential Conduits

Monthly Average Pumping Rates

BAAQMD Permits Compliance

NPDES Permits Compliance

RGRP Treatment System Operation Summary

Comparison of Concentrations

Trichloroethene (TCE) and Volatile Organic Compounds (VOC) MassRemoval

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I LIST OF FIGURES |FIGURE

NO.

1-1

1-2

1-3

3-1

4-1

4-2

4-3

4-4

4-5

4-6

4-7

4-8

4-9

4-10

4-11

4-12

4-13

4-14

4-15

4-16

DRAWINGNO.

23-016-A38

23-007-E2

23-007-E58

23-007-E57

23-016-E30

97-185-E99

23-007-E4

23-007-E56

97-183-E613

97-183-E614

97-183-E615

97-183-E616

97-183-E617

97-183-E618

23-007-E50

23-007-E49

23-007-E51

23-007-E53

23-007-E54

23-007-E55

TITLE

Site Location Map

MEW Companies Former Facilities South of U.S. Highway 101

Building and Site Plan North of U.S. Highway 101

Former Buildings and Occupants

Location of RRWs, SCRWs, and Groundwater Treatment Systems

Regional Recovery Wells, Conveyance Piping, and Treatment SystemLocation, RGRP Program North of U.S. Highway 101

Location of Soil Cleanup Activities

Potential Conduit Locations

Enlarged "A/A1" Aquifer Basemap

"A/A1" Aquifer Basemap

"B1/A2" Aquifer Basemap

"B2" Aquifer Basemap

"B3" Aquifer Basemap

C and Deep Aquifer Basemap

Enlarged "A/A1" Aquifer Abandoned Wells

"A/A1" Aquifer Abandoned Wells

"B1/A2" Aquifer Abandoned Wells

"B2" Aquifer Abandoned Wells

"B3" Aquifer Abandoned Wells

C and Deep Aquifer Abandoned Wells

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LIST OF APPENDICES

APPENDIX TITLE

A Hydrographs and Historical Water Elevation Measurements

B Historical Water Quality Measurements

C Historical Water Elevation and Capture Zone Maps

D Water Level Difference Across Aquitards

E Historical TCE Contour Maps

F TCE Dissolved Mass Calculations

G ListofARARs

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LIST OF ACRONYMS

ACRONYM DESCRIPTION

106 Order EPA 106 Order (EPA Docket No. 91-4)

1,1-DCA 1,1-dichloroethane

1,1-DCE 1,1-dichloroethene

1,2-DCB 1,2-dichlorobenzene

1,2-DCE 1,2-dichloroethene

BAAQMD Bay Area Air Quality Management District

Bgs below ground surface

CAG Community Advisory Group

CD Consent Decree (U.S. District Court Case No. C9120275JW)

Canonie Canonie Environmental Services Corporation

cis-1,2-DCE cis-1,2-dichloroethene

cm/sec square centimeters per second

CTR California Toxics Rule

DTSC California Department of Toxic Substances Control

EA Endangerment Assessment

EPA U. S. Environmental Protection Agency

ESD Explanation of Significant Difference

GAC granular activated carbon

gpd/ft gallons per day per foot

gpm gallons per minute

HLA Harding Lawson Associates

Ib. Pound

Locus Locus Technologies

MEW Middlefield-Ellis-Whisman

mg/kg milligrams per kilogram

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LIST OF ACRONYMS (CONT'D)mg/L milligrams per liter

Moffett Moffett Federal Airfield

MRLs federal minimal risk levels

NASA National Aeronautics and Space Administration

NPDES National Pollutant Discharge Elimination System

NPL National Priorities List

O&M Operation and Maintenance

PCE tetrachloroethene (perchloroethene)

PRP Potentially Responsible Party

psi Pounds per square inch

. RAOs Remedial Action Objectives

Raytheon Raytheon Company

RGRP Regional Groundwater Remediation Program

RRW Regional Recovery Well

RWQCB Regional Water Quality Control Board

SCRW Source Control Recovery Well

SCVWD Santa Clara Valley Water District

SIM selective ion mode

TCA 1,1,1-trichloroethane

TCE trichloroethene

VOCs volatile organic compounds

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EXECUTIVE SUMMARY

INTRODUCTION:

Locus Technologies prepared this five-year performancereview of the remedial actions implemented by the regionalgroundwater remediation program (RGRP) at theMiddlefield-Ellis-Whisman site in Mountain View,California (MEW Site). The purpose of the five-yearreview is to determine whether the remedy at a site isprotective of human health and the environment. This isthe first five-year review for the MEW Site. The triggeringaction for this statutory review is the initiation of theregional groundwater remediation program in 1998.

BACKGROUND:

The MEW Site includes several companies' facilities(MEW Companies) identified by the U.S. EnvironmentalProtection Agency (EPA) in the MEW Consent Decree(CD) (U.S. District Court Case No. C9120275JW), or inthe 106 Order (EPA Docket No. 91-4). Intel Corporationand Raytheon entered into the MEW CD with the EPA.Other MEW Companies - Fairchild SemiconductorCorporation; Schlumberger Technology Corporation; SMIHolding LLC; Sumitomo Mitsubishi Silicon Corporation(formerly Siltec Corporation); and Vishay GeneralSemiconductor, Inc. (formerly General InstrumentCorporation) - were named Respondents in the 106 Orderissued by the EPA. North of U. S. Highway 101, the U.S.Navy and National Aeronautics and Space Administrationare conducting their own cleanup activities.

The MEW Companies were involved in activities requiringstorage, handling, and use of chemicals at the MEW Sitesince the development of the area from agricultural tocommercial use starting around 1960. Beginning in the1990s, most of the MEW Companies ceased operations atthe Site, and many of the facilities have changed ownershipand occupancy.

Groundwater aquifers within the MEW Site consist ofshallow and deep aquifer systems, which are separated by alaterally extensive aquitard approximately 40 feet thick. Theshallow aquifer system is generally less than 160 feet belowground surface. Subdivisions within the shallow aquifer havebeen designated the "A", "Bl", "B2" and "B3" aquifers. Theshallow and deep aquifer systems at the MEW Site are notused for drinking water. The direction of groundwater flow

at the MEW Site is generally to the north. However, theconstruction of underground slurry walls and recovery wellshas altered the direction of groundwater flow in a fewlocations. The shallow and deep aquifer systems at theMEW Site are not used for drinking water

REMEDIAL ACTIONS:

The first subsurface investigation at the site was initiated in1981 and detected volatile organic compounds (VOCs) inthe groundwater and subsurface soil. Based on extensiveremedial investigation studies since then, the MEWCompanies have implemented soil and groundwaterremediation programs that have included removal ofsolvent piping, closure of all waste solvent holding sumps,removal of below ground solvent storage facilities, soilexcavation and treatment, installation of soil-bentonitecutoff walls, in-situ soil vapor extraction (SVE), in-situchemical oxidation, and groundwater extraction andtreatment. Starting as early as 1982, the MEW Companiesconstructed and operated groundwater extraction andtreatment systems to control source areas and removeVOCs from the aquifers. Remedial actions at the MEWSite have reduced unsarurated soil concentrations to belowROD cleanup standards and have substantially reduced thegroundwater concentrations of TCE and other VOCs.Recovery wells operated by the Companies for the purposeof controlling chemical sources are referred to as SourceControl Recovery Wells (SCRWs). SCRWs are installedand operated by the MEW company responsible for thechemical source area.

On 3 October 2002, the EPA requested a work plan "toconduct a human health risk assessment to evaluate thegroundwater-to-indoor air exposure pathway by collectingindoor air, outdoor air, and soil gas samples at eachFacility." In response, the MEW Companies havecollected more than 600 air samples from 25 buildingslocated at the MEW Companies' former facilities.Sampling was conducted in spring and fall 2003. Twodiscreet sampling rounds were collected in each season ateach of the selected locations, separated by a one-weekperiod.

All measured indoor air concentrations met the acceptablerisk criteria except for certain indoor samples in threebuildings, where mitigation measures are being implementedto reduce the concentrations. In the fall sampling event,

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certain buildings showed indoor air concentrations slightlyhigher than EPA Region IX's provisional value for TCEbecause these buildings were not ventilated (these buildingswere either vacant or sampled on the weekend). Once theventilation system was started again, additional samples werecollected that showed concentrations within all acceptablecriteria.

Certain pathway samples showed concentrations of TCEonly above EPA Region IX's provisional value. Althoughexposure to concentrations in pathway samples is typicallyshort and infrequent, or not feasible (e.g., samplescollected in cracks), and although EPA Region IX's draftprovisional values for TCE are unpromulgated, are subjectto change, and are under evaluation from EPA and otheragencies, the MEW Companies implemented voluntarymitigation measures for these locations.

FIVE-YEAR REVIEW PROCESS:

Groundwater monitoring has been conducted at the MEWSite since the 1980s. In general, chemicals were detected attheir highest levels early in the remedial history of the site.These levels dropped as a result of cleanup activitieseliminating source material. This assessment of theremedy at the site evaluates the following indicators:

Are proper capture zones obtained? The overall captureof the MEW plume is adequate. An area east of Hangar 1with low concentrations is not captured, but this area willbe addressed by the Navy's plan to install an additionalrecovery well to enhance capture in the area.

Are vertical gradients appropriate? From 1996 to 2003,the direction of the average vertical gradient across theaquitards has been upward. There are a few limited areaswhere downward gradients are observed across the A/B1aquitard, and a few isolated locations across the B1/B2aquitard. Examination of these downward gradientsreveals that these gradients do not adversely impact theremedial programs at the MEW Site. These locations aretypically near pumping wells in the lower aquifer, wheretiere are no pumping wells in the upper aquifer, or wherethe concentrations in the lower aquifer are higher than orsimilar to the upper aquifer.

Are the boundaries of the MEW plume stable orshrinking? Although small variations in TCEconcentration contours have resulted from changes to themonitoring network and chemical fluctuations in individualwells, the plume boundaries have remained stable since the1992 plume definition event, with some contractionobserved on the eastern edge of the plume.

Are the overall trends in concentrations decreasing? Inthe "A" aquifer, the 2002 TCE concentrations in the areasouth of Highway 101 have decreased 87% and 72%compared to 1992 and 1997 conditions, respectively. Northof the highway, the concentrations decreased by 37% and39% as compared to 1992 and 1998 conditions, respectively.

In the "Bl" aquifer, the 2002 TCE concentrations in the areasouth of Highway 101 have decreased 87% and 57%compared to 1992 and 1997 conditions. North of thehighway, the concentrations decreased by 65% and 29% ascompared to 1992 and 1998 conditions.

In the "B2" aquifer, the 2002 TCE concentrations decreased40% compared to 1997. When compared to 1992, theaverage concentrations increased by 19%. This average,however, is highly influenced by concentrations in one well,36B2, where the concentrations in this well result insignificant fluctuations in the average.

Only one well (65B3) now shows concentrations in the "B3"aquifer that would require remedial action. In the early partof the investigation, this well showed non-detectableconcentrations, but the concentrations later increased.Accordingly, the RGRP program installed a pump in the welland started extraction in 1997. The pumping resulted in adecrease of 78% in 2002 as compared to pre-pumpingconditions in 1997.

In the "C" and Deep aquifers, the RGRP Program pumpsgroundwater from the DW3 cluster of wells, the only locationwhere TCE was detected hi the MEW Site above cleanupstandards. By 2002, pumping from the wells resulted in asignificant decrease in concentrations of 91%, 83%, and 75%as compared to 1986/1987, 1992, and 1998 conditions,respectively.

Is the dissolved mass of TCE decreasing? The mass ofdissolved TCE was estimated for each sampling event forwhich a TCE concentration contour map can be drawn: 1992,1997,1998,1999, 2000, 2001, and 2002. The 1997 samplingevent was collected before start of operations of the RGRPprogram. Some source control mitigation measures hadstarted operations before 1997. The calculations estimatedthe mass of TCE dissolved in the groundwater, and did notinclude TCE that is volatilized into the gas phase, sorbed tosoil grains, or possibly present as a dense non-aqueous phaseliquid. The calculations show that TCE mass is decreasing.By 2002, the dissolved TCE mass in the plume has decreasedby 76% as compared to 1992, and by 53% as compared to1997.

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TECHNICAL ASSESSMENT:

Is the remedy functioning as intended by the decisiondocument? The MEW Companies and the RGRPprogram have implemented a number of remedies at theMEW Site to clean up the shallow aquifer zone. Theremedy is functioning as intended. The soil remedialmeasures included SVE systems and soil excavations andachieved soil cleanup goals by remediating chemicalspresent in the vadose soils. The installation of four slurrywalls effectively isolated source areas and, combined withgroundwater pumping and treatment, resulted in asignificant decrease in groundwater concentrations in theareas within and outside the slurry walls.

Although the RGRP treatment system south of Hwy. 101was modified in 2003 to result in virtually zero airemissions, the groundwater pump-and-treat remedy hasfunctioned as intended. The treatment system wasmodified in the fall of 2003 to remove the air stripper androute all groundwater to the existing tertiary carbonadsorption system. This resulted in virtually zero airemissions from the treatment system. Other than that,there were no opportunities for system optimization duringthis review.

The monitoring well network provides sufficient data toassess the progress of the remediation. This five-yearreview recommends reducing the frequency of readings ofwater elevations from quarterly to semiannually.

Are the exposure assumptions, toxicity data, cleanuplevels, and remedial action objectives used at the timeof remedy selection still valid? There have been nochanges in ARARs and no new standards affecting theprotectiveness of the remedy.

Except for a potential change in the inhalation toxicity factorfor TCE, there have been no changes in the toxicity factorsfor the contaminants of concern. One complicating factor forTCE is that EPA's most current cancer risk assessment forinhalation remains in draft form and does not include ainhalation-specific cancer slope factor. On 3 October 2002,the EPA requested a work plan "to conduct a human healthrisk assessment to evaluate the groundwater-to-indoor airexposure pathway by collecting indoor air, outdoor air, andsoil gas samples at each Facility." In response, the MEWCompanies collected more than 600 samples from 25buildings located at the MEW Companies former facilities.Sampling was conducted in spring and fall 2003. Twodiscreet sampling rounds were collected in each season ateach of the selected locations, separated by a one-week

period. Air samples were collected during a period typical ofworker exposure. Outdoor samples were also collectedaround the MEW Site up to 1.5 miles away from the site.

Outdoor samples collected outside the MEW Site met all riskevaluation criteria. In addition, all measured indoor airconcentrations met the criteria except for some samples inthree buildings were TCE concentrations were higher thanEPA Region IX's draft provisional values. Mitigationmeasures are being implemented to reduce theseconcentrations. In the fall sampling event, certain buildingsshowed TCE indoor air concentrations slightly higher thanEPA Region IX's provisional value for TCE because thesebuildings were not ventilated (these buildings were eithervacant or sampled on the weekend). Once the ventilationsystems were started again, additional samples were collectedthat showed concentrations within all acceptable criteria.

Certain pathway samples showed concentrations of TCEabove only EPA Region IX's provisional value. Althoughexposure to concentrations in pathway samples is typicallyshort and infrequent, or not feasible (e.g., samplescollected in cracks), and although EPA Region IX's draftprovisional values are unpromulgated, are subject tochange and are under further evaluation by EPA and otheragencies, the MEW Companies implemented voluntarymitigation measures for these locations.

ISSUES AND RECOMMENDATIONS

Issue: Capture zone analyses suggest that capture east ofHangar 1 warrants enhancement.Recommendation: The Navy plans to install recoverywells to enhance capture in the area.

Issue: Certain indoor air samples collected at MEWCompanies' former facilities showed concentrations ofTCE higher than EPA Region IX's draft provisional goals.Recommendation: Indoor air concentrations are beingreduced by a combination of mitigation measures includingsealing of cracks, sealing of conduits, and enhancement ofventilation.

PROTECTIVENESS STATEMENT

The remedy is expected to be protective of human healthand the environment upon attainment of groundwatercleanup standards. In the interim, exposure pathways thatcould result in unacceptable risks are being controlled, andexposure to, or the ingestion of, groundwater is prevented.Exposure to impacted soils has been addressed byindividual MEW Companies by installing and operating

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SVE systems or excavating and treating soils. These soil significantly, and that the remedy is functioning asremedies have achieved cleanup goals. required.

Long-term protectiveness of the remedial action will be NEXT REVIEWverified by obtaining additional groundwater samples to _fully evaluate the progress of remediation. Current data The next five-year review for the MEW Slte 1S re1uired b?indicate that the concentrations have decreased Au?ust 2009> five years after EPA finalizes its five-year

review.

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FIVE-YEAR PERFORMANCE REVIEWREGIONAL GROUNDWATER REMEDIATION

PROGRAM (RGRP)MIDDLEFIELD-ELLIS-WHISMAN SITE

MOUNTAIN VIEW, CALIFORNIA

1. INTRODUCTION

This document presents a five-year performance review of the Regional GroundwaterRemediation Program (RGRP) at the Middlefield-Ellis-Whisman site in Mountain View,California (MEW Site). The location of the MEW Site is shown on Figure 1-1. The purpose ofthe five-year review is to determine whether the remedy at the site is protective of human healthand the environment. The methods, findings, and conclusions of the review are documented inthis report. In addition, this five-year review identifies issues found during the review, if any,and recommendations to address them.

Locus Technologies (Locus) prepared this five-year review report on behalf of FairchildSemiconductor Corporation (Fairchild) and Raytheon Company (Raytheon) as projectcoordinators for the RGRP during the time period covered by this review. Pursuant to CERCLA§121 and the National Contingency Plan (NCP), CERCLA §121 provides:

If the President selects a remedial action that results in any hazardous substances, pollutants, orcontaminants remaining at the site, the President shall review such remedial action no less often thaneach 5 years after the initiation of such remedial action to assure that human health and the environmentare being protected by the remedial action being implemented. In addition, if upon such review it is thejudgement of the President that action is appropriate at such site in accordance with section [9604] or[9606] of this title, the President shall take or require such action. The President shall report to theCongress a list of facilities for which such review is required, the results of all such reviews, and anyactions taken as a result of such reviews.

This requirement is interpreted further in the NCP 40 CFR §300.430(f)(4)(ii), as follows:

If a remedial action is selected that results in hazardous substances, pollutants, or contaminantsremaining at the site above levels that allow for unlimited use and unrestricted exposure, the lead agencyshall review such action no less often than every five years after the initiation of the selected remedialaction.

This is the first five-year review for the MEW Site. The triggering action for this statutoryreview is the initiation of the RGRP in 1998. The five-year review is required because chemicals

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remain in groundwater at the site above levels that allow for unlimited use and unrestrictedexposure.

The MEW Site includes several companies' (MEW Companies') facilities identified by EPA inthe MEW,Consent Decree (CD) (U.S. District Court Case No. C9120275JW), or in the 106Order (EPA Docket No. 91-4). Figure 1-2 shows the MEW Companies former facilities andcurrent occupancy. Intel Corporation and Raytheon entered into the MEW CD with the EPA.Other MEW Companies - Fairchild Semiconductor Corporation; Schlumberger TechnologyCorporation; SMI Holding LLC; Sumitomo Mitsubishi Silicon Corporation (formerly SiltecCorporation); and Vishay General Semiconductor, Inc. (formerly General InstrumentCorporation) - were named Respondents in the 106 Order (EPA Docket No. 91-4) issued byEPA. North of U. S. Highway 101 (Figure 1-3), the U.S. Navy and National Aeronautics andSpace Administration are conducting their own cleanup activities.

Locus prepared this five-year evaluation report in accordance with the U. S. EnvironmentalProtection Agency's (EPA's) June 2001 Comprehensive Five-Year Review Guidance (EPA,2001). The MEW Companies were notified of the initiation of the five-year review on 10October 2003 in an email from the EPA remedial project manager, Ms. Alana Lee, entitled "EPAInformation Request and Notification for MEW Five-Year Review". As part of the five-yearreview, EPA requested site-specific information as the foundation of the technical assessment ofthe remedy. Table 1-1 is a reference list showing where EPA's requested items can be found inthis document or the accompanying CD ROM disk.

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2. CHRONOLOGY OF EVENTS

The following table provides a chronology of major events for the RGRP program at the MEWSite.

Date

November 1981

December 1982

February 1982

Spring 1984

April 1985

August 1985

October 1986

1987

July 1987

Event

Chemical leak was identified at Intel in an underground vault.Vault was removed.

Groundwater investigations were initiated at MEW.

Groundwater remediation was initiated at Intel and Fairchild byinstalling pumping wells.

Fairchild, Intel, Raytheon, NEC, and Siltec (theMiddlefield-Ellis-Whisman Group) conducted a jointgroundwater investigation program.

The RWQCB referred the Companies' investigative programs toEPA.

Fairchild, Intel, and Raytheon entered into an AdministrativeOrder on Consent to jointly perform a RemedialInvestigation/Feasibility Study (RI/FS) program for EPA.

Fairchild installed underground slurry walls around three of itsformer properties to physically contain on-site chemical residuesin the "A" aquifer.

Raytheon installed a slurry wall around its former facility at 350Ellis St. to physically contain on-site chemical residues in threeaquifer formations.

The Remedial Investigation report was submitted to EPA. Morethan 400 monitoring wells were installed and sampled toinvestigate chemical concentrations in 8 aquifer zones to 550 feetbelow the ground surface.

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Date

November 1988

June 1989

'September 1990

November 1990

April 1991

March 1992 -July 1994

November 1991 -April 1995

December 1992

Event

The Feasibility Study report was submitted to EPA. Pump-and-treat was proposed as the remedial technique for the regionalgroundwater. Soil vapor extraction and/or soil excavation wasproposed as the remedial technique for shallow soils.

EPA issued the ROD. The ROD specified TCE as the indicatorchemical and included cleanup levels for TCE and 10 otherchemicals. Using the conclusions of the Feasibility Study, theROD identifies pump and treat with air stripping and/or carbonadsorption as an appropriate remedial technology forgroundwater. The ROD identifies soil excavation/aeration and/orsoil vapor extraction as an appropriate remedial technology forvadose soils

EPA issued an Explanation of Significant Differences.

EPA issued a Section 106 Order to Fairchild, NEC, Siltec/GeneralInstrument (now Sumco/Vishay), Sobrato (SMI Holdings), UnionCarbide, National Semiconductor Corporation, and Spectrace.Facility-Specific Work requires remediation of soils andgroundwater. Joint Work includes sealing potential conduit wells,plume definition, groundwater chemistry, and water reuseprograms.

EPA lodged the MEW Consent Decree (CD), which required Inteland Raytheon to design and construct the regional groundwaterremedial system and to perform Facility-Specific remedial work.

The Potential Conduit Program was implemented, which includedinvestigation and sealing of up to 16 old agricultural wells.

Preliminary and final design documents and drawings for sourcecontrol measures (design of pump-and-treat, soil excavation, soilvapor extraction, air sparging) were developed by the MEWCompanies and submitted to EPA.

The Plume Definition Program was completed. The programincluded sampling of more than 200 monitoring wells to definethe vertical and horizontal extent of the plume.

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Date

September 1993 -February 1997

Winter 1997-Fall 1998

1997-2000

January 1998

October 1998

July 2000

April 2001

December 2002

April 2003

May and October 2003

October 2003

Event

Preliminary and final design documents and drawings for the tworegional groundwater treatment systems south and north of Hwy101 were developed and submitted to EPA.

Several MEW Companies installed or expanded groundwaterextraction systems as source control measures.

MEW Site was redeveloped, including construction of newAOL/Netscape, Nokia, Veritas, and Verisign campuses.

Construction of the RGRP South of 101 was completed.Treatment system started operating on 6 January 1998.

Construction of the RGRP North of 101 was completed.Treatment system started operating on 15 October 1998.

The two-year evaluation for the RGRP South of 101 wassubmitted to EPA.

The two-year evaluation for the RGRP North of 101 wassubmitted to EPA.

Work plan for air sampling at MEW Site was submitted to EPA.

Revised work plan for air sampling at MEW Site was submittedto EPA.

MEW Companies implemented the air-sampling program.Samples were collected from 25 buildings, and from 13 referenceand background area locations.

RGRP treatment system South of 101 was modified to be limitedto aqueous carbon adsorption to achieve virtually zero airemissions.

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3. BACKGROUND

This chapter provides background information on the MEW Site in Mountain View, includingdescriptions of the physical characteristics of the MEW Site, land and resource use, history of theenvironmental investigation and remediation, and the basis for taking these actions.

3.1. Physical Characteristics

The MEW Site defines the limits within which remedial activities are performed. The site islocated in Mountain View, Santa Clara County, California (Figures 1-1 and 1-2). MountainView is a town of approximately 70,000 residents, located in Santa Clara County. At the MEWSite, a number of companies were involved in activities requiring storage, handling, and use ofchemicals. These companies are referred to as MEW Companies in this document.

3.2. Land and Resource Use

The area around Middlefield Road, Ellis Street, Whisman Road, and U.S. Highway 101 inMountain View includes locations of several current and former semiconductor and othermanufacturing and industrial facilities. Until 1959, the area south of U.S. Highway 101 wasused for agricultural purposes, at which time the area began to be commercially developed withlight-industrial facilities (Figure 3-1). Operations in this area have included semiconductor andelectronics manufacturing, metal finishing, and other activities that used chemicals. While inoperation, these facilities required the storage, handling, and use of a variety of chemicals,particularly solvents and others in manufacturing processes. Some of the chemicals leaked orwere otherwise released to the ground. The former U.S. Naval Air Station, Moffett Field, islocated just north of U.S. Highway 101.

Agricultural development in this area began in the mid 1800s. Until about 1960, orchards, lowcrops, and greenhouse gardening dominated the area. North of U.S. Highway 101, MoffettFederal Airfield (Moffett) was commissioned in 1933. The National Aeronautics and SpaceAdministration (NASA) Ames Research Center, also north of the highway, was originallyopened in 1940 adjacent to Moffett Field as a laboratory of the National Advisory Committee onAeronautics.

The MEW Companies have ceased operations at the Site, and many of their former facilities havechanged ownership and occupancy (Figure 1-2).

Groundwater aquifers within the MEW Site consist of shallow and deep aquifer systems, which areseparated by a laterally extensive aquitard approximately 40 feet thick. The shallow aquifer systemis generally less than 160 feet below ground surface (bgs) south of U.S. Highway 101 and generally

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less than 100 feet bgs north of U.S.Highway 101. Subdivisions within theshallow aquifer have been designatedthe "A/A1", "B1/A2", "B2" and "B3"aquifers. - The regional aquitard isdesignated the "B/C" aquitard. Thezones below the "B/C" aquitard aretermed the "C" aquifer and the Deepaquifers. Groundwater flow in theshallow aquifer zone is generally to thenorth, while flows in the "C" and Deepaquifers are generally to the northeast.

Aquifer Zone

"A" [or "A/A1"]

"Bl" [or "B1/A2]

"B2"

"B3"

"C"

"Deep"

water.

Approximate Depth Interval

Below Ground Surface

0 to 45 feet

50 to 75 feet

75 to 110 feet

120 to 160 feet

200 to 240 feet

Generally deeper than 200 feetThe shallow and deep aquifer systemsat the MEW Site are not used for drinking

The direction of groundwater flow at the MEW Site is generally to the north. However, theconstruction of underground slurry walls and recovery wells has altered the direction ofgroundwater flow in certain locations (e.g., the groundwater may flow to the west or east aroundslurry walls - see Appendix C). Several pumping tests have been performed to estimate aquiferparameters such as transmissivity and hydraulic conductivity. A summary of the results isprovided in Table 3-1.

3.3. History of Environmental Investigation and Remediation

The MEW Site, Moffett and the NASA Ames Research Center, include locations of severalcurrent and former semiconductor and other manufacturing and industrial facilities. Operationsin this area have included semiconductor and electronics manufacturing, metal finishing, andother activities that used chemicals. While in operation, these facilities required the storage,handling, and use of a variety of chemicals, particularly solvents and others in manufacturingprocesses. Some of the chemicals leaked or were otherwise released to the ground. The releasedchemicals impacted the soil and the groundwater.

In 1981, Intel and Fairchild initiated subsurface investigations, which detected volatile organiccompounds (VOCs) in the groundwater and subsurface soil. Around the same time, othercompanies at nearby sites also conducted separate investigations, which confirmed the presenceof similar VOCs in soil and groundwater. Since then, numerous monitoring wells have beeninstalled by the RGRP program and the MEW Companies to complete the groundwaterinvestigation. Table 3-2 lists monitoring well details for wells currently monitored by the RGRPprogram. Other monitoring wells have been installed that are being monitored by the individualMEW Companies, the Navy, and NASA. Table 3-3 lists monitoring wells that have been sealedsince the remedial investigation started. The Remedial Investigation report for the MEW Siteincludes detailed descriptions of the early investigations performed in the 1980s (HLA, 1988).

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3.4. Initial Remedial Actions

After the discovery of chemicals in soil and groundwater, several MEW Companiesimplemented a number of on-site source control and groundwater remedial actions includingremoval of solvent piping, closure of all waste solvent holding sumps, removal of below groundsolvent storage facilities, startup of groundwater extraction and treatment systems, excavation ofsoils, installation of soil vapor extraction systems, and construction of four slurry walls to controlthe migration of chemicals.

3.5. Basis for Taking Action

Chemicals of concern defined in the ROD and the CD are:- trichloroethene (TCE)

1,2-dichloroethene (cis and trans isomers - cis-l,2-DCE and trans- 1,2-DCE)- 1,1,1 -trichloroethane (TCA)- l,2-dichlorobenzene(l,2-DCB)

chloroform- vinyl chloride- FreonllS- 1,1 -dichloroethane (1,1 -DCA)- tetrachloroethene (PCE)- 1,1-dichloroethene (1,1-DCE)- phenol

In addition, the ROD and CD list four metals as chemicals of concern: antimony, arsenic,cadmium, and lead.

An endangerment assessment (EA) (ICF-Clement, 1988) of the MEW Site by EPA evaluatedwhether or not the MEW Site poses a hazard to public health, welfare, or the environment. Thereport concluded that there is no imminent or substantial endangerment associated with contactwith surface soils. The EA identified the only potentially significant exposure pathway as that togroundwater containing chemicals; however, there were and are no water supply wells at the site.

On 3 October 2002, the EPA requested additional ah- sampling data to further evaluate thepotential migration of VOCs from the groundwater to the indoor air of commercial buildings atthe MEW Companies' former facilities. The 1988 EA for the MEW Site did not provide aquantitative evaluation of this groundwater-to-indoor air exposure pathway. The toxicity factorsfor one of the chemicals of concern (TCE) have been reassessed since the EA and facility-specific risk assessments were conducted (HLA, 1999, Smith 1997 and Locus 1997). For EPA toevaluate the protectiveness of remedial actions at the MEW Site, EPA requested a work plan toconduct a human health risk assessment to evaluate the groundwater-to-indoor air exposurepathway by collecting air samples.

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Middlefield-Ellis-Whisman SiteMountain View, California

Locus

4. REMEDIAL ACTIONS

The ROD for the MEW Site was issued in May 1989. Remedial Action Objectives (RAOs) weredeveloped as a result of data collected during the Remedial Investigation (HLA, 1988) to aid inthe development and screening of remedial alternatives to be considered for the ROD. TheFeasibility Study (Canonie, 1988) for the MEW Site lists the RAOs to be:

1. Protection of potential potable water supply;2. Remediation or control of relatively elevated concentrations of chemicals present in

localized vadose zone soils below the ground surface that could migrate into the shallowgroundwater system;

3. Remediation or control of groundwater, which contains elevated concentrations ofchemicals, including control of discharge of such groundwater into surface water.

For the vadose soils, the ROD selects two remedial technologies: 1) in situ soil vapor extraction(SVE) with treatment by vapor-phase granular activated carbon (GAC), and/or 2) excavationwith treatment by aeration. The cleanup levels for soils containing TCE were established in theROD to be 1 milligram per kilogram (mg/kg) for soils contained within slurry walls and 0.5mg/kg for soils outside slurry walls.

For groundwater, the ROD specifies hydraulic remediation by groundwater extraction andtreatment by air stripping or liquid-phase GAC. Air-bome emissions from air strippers arerequired to meet Bay Area Air Quality Management District (BAAQMD) emission standards.The cleanup level for groundwater containing TCE at the site is 0.005 mg/L in the shallowaquifers and 0.0008 mg/L in the deep aquifers.

EPA issued an Explanation of Significant Difference (BSD) for the MEW Site in September1990. The purpose of the BSD was to clarify that the numerical standards characterized as"goals" in the ROD are final cleanup "standards".

4.1. Remedy Implementation

Remediation at the MEW Site includes mitigation measures that address chemicals in thegroundwater, soils, and air. These mitigation measures were and are performed according tospecifications.

Subsurface investigations were initiated at the MEW Site in 1981. Since then, substantial amountsof groundwater and soil monitoring and remediation have been completed at the Site. Remedialinvestigation efforts have included over one thousand soil borings, soil gas collection, andthousands of soil and water samples.

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4.1.1. Remedial Measures Implemented by the MEW Companies

Based on the extensive remedial investigation studies, the MEW Companies have implemented soiland groundwater remediation .programs that have included soil excavation and treatment,installation" of soil-bentonite cutoff walls, in-situ soil vapor extraction (SVE), in-situ chemicaloxidation, and groundwater extraction and treatment. Starting as early as 1982, the MEWCompanies have constructed and operated groundwater extraction and treatment systems to controlsource areas and remove VOCs from the aquifers. Remedial actions at the MEW Site have reducedvadose soil concentrations to below ROD cleanup standards and have substantially reduced thegroundwater concentrations of TCE and other VOCs. Investigation and remediation efforts havebeen described in detail in numerous reports, and have been summarized primarily in the MEWRemedial Investigation (RI) Report, (HLA, 1988), the Feasibility Study (Canonie, 1988), and theTwo-Year Evaluation reports (Locus, 2000b & 2001).

Recovery wells operated by the Companies for the purpose of controlling chemical sources arereferred to as Source Control Recovery Wells (SCRWs). SCRWs are installed and operated by theMEW company responsible for the chemical source area. For more details on the remedial measuresimplemented at the MEW Site, the reader should refer to facility-specific reports, to the regionaldesign report (Smith, 1996a&b), and the operation and maintenance plans (Locus, 1999 & 2000a).The locations of regional and source control recovery wells and groundwater treatment systems areshown on Figures 4-1 and 4-2. Areas where soil remediation was implemented are shown on Figure4-3.

4. L1.1 Fairchild Sent iconductor Corp oration

Fairchild operates a total of 31 recovery wells that convey groundwater to three GAC groundwatertreatment systems.

515/545 Whisman Road and 313 Fairchild Drive

This area is located southeast of the intersection of Whisman Road and Fairchild Drive. A slurrywall was installed in 1986 around these former facilities to limit migration of chemicals. This slurrywall is approximately 40 feet deep and is keyed into the "A/B" aquitard.

Soils requiring remediation [greater than 0.5 and 1 milligram per kilogram TCE outside and insideslurry wall enclosures, respectively] above 6 feet were excavated and aerated. On September 15,1995, EPA approved a work plan for additional subsurface investigations in the area. The objectiveof the investigation was to provide data to evaluate the use of soil excavation instead of SVE atlocations where previously unsaturated soils had become saturated because of the rising water table.The investigation, area-redevelopment constraints, and cost analysis revealed that soil excavationand aeration was more feasible than SVE. Subsequently, and after EPA's approval of theexcavation plans, vadose zone soils below 6 feet were also excavated and aerated.

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To control and remediate sources in the groundwater, Fairchild currently operates 12 SCRWs bothinside and outside the slurry wall.

401 National Avenue*"""""""™""*"""""™^ ^ " ^ ^ ^~ i

A slurry wall was installed in 1986 around this former facility and is keyed into the "A/B" aquitardat a depth of approximately 40 feet.

In the vadose zone, soils requiring remediation in the top 6 feet were excavated and aerated in 1995.The deeper soil (from 6 feet bgs to 18 inches above the groundwater table) was remediated using aSVE system. This system consisted of 29 air extraction/inlet wells and five air-inlet wells. Theextracted air was treated using a vapor phase carbon adsorption system to remove the chemicals.The system was operated from February 1996 to June 1997. Soil samples collected after the systemwas shutdown confirmed that the soils reached the cleanup standards (0.5 and 1 mg/kg, TCE insideand outside the slurry walls, respectively).

Groundwater recovery wells in this area include four SCRWs being operated within the Building 9slurry wall enclosure. Three other SCRWs have also been installed north of this facility, and aredesignated as a joint responsibility of Vishay General Semiconductor, Sumitomo Mitsubishi SiliconAmerica and Fairchild.

369 and 441 North Whisman Road

In 1986 Fairchild installed a slurry wall around the former Building 19 at this property. The wall isapproximately 40 feet deep and is keyed into the "A/B" aquitard.

hi November 1994, the upper six feet of soil requiring remediation were excavated and stockpiled.The excavated soil was then treated by aeration. In April 1995, the soil was backfilled aftersufficient testing showed that the chemical concentrations were below site cleanup standards.

For vadose soils requiring remediation more than 6 feet bgs, an SVE system was installed andoperated. The extracted air was treated using a resin adsorption system and a vapor-phase granularactivated carbon adsorption system. This system was in operation from April 1996 until February1997, when soil chemical concentrations were observed to be below site cleanup levels.

Within the slurry wall, Fairchild operates seven "A" aquifer SCRWs. Outside the slurry wall,Fairchild also operates two "A" aquifer SCRWs downgradient of the slurry wall. In the "Bl", and"B2" aquifers, Fairchild operates three and two SCRWs, respectively.

644 National Avenue

Shallow soils exceeding cleanup standards were found in one isolated spot northwest of thisbuilding. These soils were excavated to a depth of 13 feet and aerated. One SCRW is beingoperated in the "A" aquifer northwest of the building.

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4.1,1.2 Vishay General Semiconductor, Inc. and Sumitomo Mitsubishi SiliconAmerica

Vishay General Semiconductor,, Inc. (formerly General Instrument Corporation) and SumitomoMitsubishi-Silicon America (formerly Siltec) (Vishay/SUMCO) had both occupied the building at405 National Avenue. They operate five SCRWs in the "A" aquifer to control onsite sources. Theextracted groundwater is first pretreated by an ultraviolet light-hydrogen peroxide treatment systemand then undergoes final treatment through an air stripper. Treated effluent is discharged to the Cityof Mountain View sanitary sewer system. The treatment system is located at the 401 NationalAvenue property.

To remediate vadose zone soils exceeding cleanup standards, an SVE and treatment system wasinstalled at the 405 National Avenue facility. The vapors from the wells were treated using three2000-pound vapor phase granular activated carbon beds. The SVE system operated until March1999. Soil samples collected after the system was shut down confirmed that the soils had achievedthe cleanup standards. By September 1999, the SVE system was removed from the site withapproval from the EPA.

Three other SCRWs in this area, screened in the "A", "Bl" and "B2" aquifers, are designated as ajoint source control responsibility of Vishay, SUMCO, and Fairchild. Groundwater extracted fromthese wells is also conveyed to the treatment system described above.

4.1.1.3 Intel Corporation/Raytheon Company

The property at 365 East Middlefield Road (Lot 3) was occupied by Intel. The property at 415 EastMiddlefield Road (Lot 5) was occupied by Raytheon. Both companies shared the use of an acidneutralization system on the adjoining vacant lot (Lot 4).

In 1981, the Intel waste-solvent tank was removed and the concrete vault was cleaned. BetweenOctober 1984 and July 1985 over 4,000 cubic yards of Lot 3 soil, near a former chemical vault,were excavated to a maximum depth of 35 feet bgs and treated by Intel. The concrete vault wasalso removed as part of this remedial action.

At Lots 4 and 5, remedial plans prepared by Raytheon provided for installation of an SVE system toremediate vadose zone soils exceeding cleanup standards. Subsequently, because of the rising watertable in the area, Raytheon performed a feasibility study, which showed that SVE was not feasible.

To control groundwater sources, four SCRWs were installed in Lot 3, three in the "A" aquifer andone in the "Bl" aquifer. Additionally, Raytheon installed a "B2" SCRW north of Middlefield Roadand southwest of the Raytheon slurry wall, hi May 1998, Intel was granted permission by the EPAto shut down the most upgradient "A" aquifer SCRW.

Groundwater extracted from the SCRWs in Lot 3 is conveyed to a GAC system for treatment, andthe treatment system effluent is discharged to Stevens Creek. Groundwater extracted from the

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Raytheon "B2" well is conveyed to the Raytheon treatment system located at the 350 Ellis Streetproperty.

4.1.1.4 Raytheon Company

In 1987, Raytheon installed a 100-foot-deep slurry wall around its former 350 Ellis Street facility toisolate the chemicals at the facility. The wall extends through the "A" and "Bl" aquifer to the upperhalf of the "B2" aquifer.

An SVE system was also installed at the 350 Ellis Street facility in the area immediately north of theslurry wall. This system included 135 vapor extraction wells and a vapor treatment systemconsisting of two 8,000-pound vapor-phase GAC units (Groundwater Technology, 1996).

Raytheon operates four "A" aquifer and one "B2" aquifer SCRWs within the slurry wall enclosurearea. Outside of the slurry wall, Raytheon operates one SCRW in each of the "A" and "B" aquifers.Extracted groundwater is treated onsite using an oxidation system followed by a 2000-lb GACvessel. The treated effluent is discharged to Stevens Creek.

4. L1.5 NEC Electronics, Inc.

NEC occupied facilities at the 501 Ellis Street property. In December 1991, NEC completedremediation of vadose zone soils exceeding cleanup standards at the property. Approximately 210cubic yards were excavated and removed from the site for treatment and disposal.

NEC operates three SCRWs in the "A" aquifer. Groundwater extracted from the wells is conveyedto a treatment system consisting of three 180-^pound granular activated carbon vessels. The treatedeffluent is discharged to Stevens Creek.

4.1.1.6 Sobrato Development Company

SMI Holding LLC (SMI) is implementing the requirements of the 106 Order issued to SobratoDevelopment Company. An air sparging/SVE (AS/SVE) pilot study was conducted and a full-scaleAS/SVE system was installed. The AS/SVE system operated until rising water levels forcedclosure of eight vertical SVE wells and shutdown of the AS system. The SVE system continued tooperate with a horizontal well, and extracted vapors were treated by GAC. In 2001, EPA approvedclosure of the SVE system following confirmatory soil sampling to verify that soil cleanup goalswere achieved.

Four SCRWs are operated by SMI in the "A" aquifer. Extracted groundwater is treated through two1000-pound GAC vessels in series. A chemical oxidation pilot test using potassium permanganateto reduce groundwater VOC concentrations was conducted at the SMI site in November andDecember 2000, with the highest volume of potassium permanganate solution injected near the wellwith the highest VOC concentrations. Residual effects of the treatment continue to be noted: the

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TCE concentration in the area treated most extensively (near well SO-PZ2) has been reduced fromthe pre-injection concentration of 0.29 mg/L to 0.12 mg/L in December 2002. Further injection ofpotassium permanganate solution to further reduce groundwater concentrations is pending EPAapproval.

i

4.1.2. R em edial Program s Imp lem ented by the R GRP

The treatment systems for the regional groundwater remediation program were designed to removechemicals that have already migrated beyond the SCRWs where the responsibility for the bulk ofthe chemicals present cannot be attributed to a single source area. Thus, they are locateddowngradient of identified source areas and SCRWs. Groundwater recovery wells that operate aspart of the RGRP are labeled Regional Recovery Wells (RRWs).

4.1.3. Potential Con duits Program

Potential agricultural well locations were identified within and near the MEW Site (Figure 4-4). Thewells were identified from Santa Clara Valley Water District (SCVWD) records, interviews withlong time residents, interviews with well drillers who have worked in the area, aerial photographs,and door-to-door surveys.

The work identified 30 wells to be investigated (Table 4-1). These wells were believed to be withinwhat was known as the Study and Remediation (SAR) boundary, which defined the extent of thespread of the MEW chemicals of concern.

Several reports on potential conduits have been submitted to EPA (Canonie, 1992a through 1992cand 1993a through 1993J). Of the 30 wells, 2 were found to be outside the MEW plume boundaries;2 were found to be abandoned and filled with soil, debris, or concrete; 3 were classified as non-existent; 2 could not be located; 1 is believed to be located under a garage and could not beaccessed; and 2 are still in use but show no adverse effect on vertical plume migration. Theremaining 18 wells were located and sealed. The wells were sealed in accordance with Santa ClaraValley Water District (SCVWD) requirements.

4.1.4. Plum e Definition Program

The plume definition program was a coordinated well sampling program that provided informationon the vertical and horizontal extent of 15 organic and inorganic chemicals specified in the 106Order to delineate the MEW plume and to analyze the possibility of surface waters comminglingwith the MEW plume. A correlation of aquifer zones across U.S. Highway 101 was also performedfrom the MEW Site south of the highway to the area north of the highway.

Contours of chemical concentrations were drawn for all aquifers in which chemicals of concernwere detected above the laboratory detection limits. These drawings were presented in the PlumeDefinition Program Report (Canonie, 1993k) submitted to EPA in March 1993. The MEW plumesouth of U.S. Highway 101 was defined both laterally and vertically as part of the Plume DefinitionProgram. Examination of concentration contours suggested the following:

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• The general plume configuration had changed very little since 1987.

• Chemical concentrations in the "B3" aquifer were detected in a localized area for thefirst time (in Well 65B3).

• In general, the chemical concentrations within the plume appeared to be relativelystable.

4.1.4.1 Groundwater Remediation by RGRP Program South of U.S. Highway 101

The RGRP program South of Hwy. 101 operates five, six, four and one RRWs, in the "A", "Bl","B2" and "B3" aquifers, respectively. In the "A" aquifer, the RRWs are REG-1A, REG-10A, REG-11A, REG-12A, and RW-9A. The RRWs operated in the "Bl" aquifer are REG-1B1, REG-2B1,REG-3B1, REG-4B1, REG-11B1, and RW-9(B1). In the "B2" aquifer, the RRWs are 38B2, REG-1B2, REG-3B2, and RW-9(B2). RRW 65B3 is screened in the "B3" aquifer. In addition, threedeep aquifer RRWs operate to remediate the groundwater below the "B/C" aquitard. Figure 4-1shows the location of the RRWs and the conveyance piping.

Average monthly flow rates are shown in Table 4-2. Design flow rates for RGRP recovery wellsare specified in the Final Design reports (Smith, 1996a). These flow rates were determined using agroundwater flow model and calibrated to achieve appropriate capture zones and vertical hydraulicgradients across aquitards. Actual flow rates may have been adjusted from the initial design flowrates to achieve these goals. Regular monitoring of water elevations is used to verify that theappropriate capture zones and vertical gradients are maintained.

Extracted groundwater is treated by an RGRP treatment system located at the 644 National Avenueproperty. Until October 2003, the system consisted of two treatment components. The first was alow-profile air-stripping unit that treated low-concentration groundwater from wells REG-1A,REG-10A, REG-11A, REG-2B1, REG-3B1, REG-11B1, and REG-3B2. The second componentincluded three 10,000-lb GAC vessel units, installed in series, to treat higher concentrationgroundwater extracted from REG-12A, REG-1B1, and REG-1B2. The treated water is dischargedinto the local storm drain under a National Pollutant Discharge Elimination System (NPDES)permit.

The air stripper operated under a BAAQMD permit. The system influent was sampled dailyduring the first 3 days of system operation, then at least once monthly. Reports demonstratingcompliance with the BAAQMD permit were prepared monthly and maintained at the treatmentsystem. No violations of the BAAQMD permit occurred during operation of the air stripper(Table 4-3).

In October 2003, the MEW Companies voluntarily modified the RGRP treatment system to achievevirtually zero air emissions from the system. With U.S. EPA's approval, the air stripper wasshutdown on 1 October 2003 and modified on 1 and 3 October so that all extracted groundwater istreated through the aqueous GAC unit. Regional Water Quality Control Board's (RWQCB's)

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approval of the treatment system modifications was received on 27 October 2003, and the systemwas restarted on 27 October. Extracted groundwater is now treated only by the aqueous GAC unit.

The RGRP treatment system discharges to the local storm drain under NPDES General PermitOrder No. 99-051. Effluent samples are collected monthly to verify compliance with the permit.Reports including monitoring results and a summary of system operations are prepared and sentquarterly to the Regional Water Quality Control Board (RWQCB). To date, no permit violationshave occurred (Table 4-4).

In addition to the regional treatment system, groundwater from some RRWs is conveyed toFairchild treatment systems. Groundwater from well 38B2 is conveyed to System No. 1,groundwater from wells RW-9A and RW-9B1 is conveyed to System No. 3, and groundwater fromREG-4B1,65B3, and the deep aquifer wells at DW3 is conveyed to System No. 19.

4.1.4.2 Groundwater Remediation by RGRP Program North of U.S. Highway 101

The regional groundwater recovery system north of U.S. Highway 101 consists of 14 RRWs (eight"A/A1" aquifer wells and six "B1/A2" aquifer wells). The eight RRWs operating in the "A/A1"aquifer north of U.S. Highway 101 are REG-2A, REG-3A, REG-4A, REG-5A, REG-6A, REG-7A,REG-8A, and REG-9A. In the "B1/A2" aquifer, the six RRWs north of the highway are REG-5B1,REG-6B1, REG-7B1, REG-8B1, REG-9B1, and REG-10B1. Because the groundwater is belowcleanup standards, there are no RRWs in the "B2", "B3" or "C "aquifers north of U.S. Highway 101.Extracted groundwater from the RRWs is conveyed through a network of double-contained pipesand treated by the groundwater treatment system located on the north side of Wescoat Road and eastof McCord Avenue, between Buildings 15 and 510 (Figure 4-2).

The treatment system pad is in the location of former Building 117, which was demolished prior tothe construction of the treatment system pad. Treated water is conveyed through a single-containedhigh density polyethylene pipeline for either reuse at NASA's Unitary Cooling Tower located on DeFrance Avenue or discharge to Stevens Creek under an NPDES permit.

The treatment system consists of two six-tray, skid mounted low profile air strippers that operate inseries. The design was selected based on the groundwater extraction rates and concentration data.The extracted groundwater is treated by the lead air stripper (AS-1) first; treated water from the leadair stripper is then treated by the lag air stripper (AS-2). The off-gas from AS-1 is treated by two4,000-lb. vapor phase GAC units before being discharged to the atmosphere. The off-gas from AS-2 is emitted under a BAAQMD permit. The system is designed to treat up to 200 gallons perminute of groundwater.

Before any treatment is conducted, groundwater runs through two high-capacity, cartridge stylefilter units that are used as primary and secondary filtration to remove particulates greater than20um. Following filtration, a carbonate scale inhibitor, CE-1000, is added to the water that entersAS-1. The use of CE-1000 reduces the build-up of calcium carbonate scale in both air strippers andpiping downstream.

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Blowers that are connected to variable frequency drives control the airflow through each airstripper. The blower for AS-1 is a 20 horsepower positive displacement rotary lobe blower, whichis housed in a sound attenuation enclosure. The blower for AS-2 is a 10 horsepower pressureblower that has a silencer on the inlet side of the blower to reduce the noise from the unit to lessthan 80 dBA. Each air stripper is equipped with a 15 horsepower pump, which controls the treatedwater level inside the air stripper plenum. Water from AS-1 is discharged to the inlet of AS-2;water from AS-2 is discharged for reuse at NASA's Unitary Cooling Tower or discharge to StevensCreek.

The treatment pad is also equipped with a sump pump that is designed to pump water from the padsump back into the inlet side of AS-1. The sump pump effluent water is filtered w/ a basket strainerto remove large particulate matter before air stripping.

To verify compliance with BAAQMD permit, the influent to the air stripper is sampled monthly.Monthly reports demonstrating compliance with the BAAQMD permit are prepared and maintainedat the treatment system. To date, no violations of the BAAQMD permit have occurred (Table 4-3).

The RGRP treatment system discharges to Stevens Creek under the National Pollutant DischargeElimination System (NPDES) general permit (Order No. 99-051). Effluent samples are collectedmonthly to verify compliance with the permit. Reports including monitoring results and asummary of system operations are prepared and sent quarterly to the RWQCB. To date, nopermit violations have occurred (Table 4-4).

4.1.5. Rem edial Measures Imp lent ented by Others

In addition to the MEW remedial measures described above, two recovery wells have been installedas part of the Silva Well Program to address low concentrations of chemicals in the "Bl" and "C"aquifers observed just west of the MEW Site. The extracted groundwater is discharged directly tothe sanitary sewer under a permit from the City of Mountain View.

Other remedial programs at the MEW Site include those implemented by the U.S. Navy andNASA at Moffett. Programs near the MEW Site include the Hewlett-Packard site east of EllisStreet.

4.1.6. Air

On 3 October 2002, the EPA requested a work plan "to conduct a human health risk assessmentto evaluate the groundwater-to-indoor air exposure pathway by collecting indoor air, outdoor air,and soil gas samples at each Facility." In response, the MEW Companies submitted a unifiedwork plan on 2 December 2002 (Locus, 2002), and a revision on 16 April 2003 (Locus, 2003a)responding to EPA's 17 February 2003 comments. NEC chose to submit its own work plan(Geosyntec, 2003a), which was similar to the unified work plan. The results of the springsampling event were submitted to EPA by each of the MEW Companies (Locus, 2003b&c;Weiss, 2003a; PES, 2003; Geomatrix, 2003; Geosyntec, 2003b). The results of the fall samplingevent will be submitted to EPA in January 2004.

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4.1.6.1 Types of Samples

Indoor air concentrations can 'be attributed to facility or occupational sources (e.g., sourcesattributed to building construction, operations, and occupation), indoor accumulation, potentialvolatilization from the groundwater into the building, and contributions from outdoor air.Accordingly, the following types of air samples were collected by the MEW Companies:

Indoor Sa/np/es, collected in areas typically occupied by workers, at breathing zone height. Theresults were used to estimate potential worker exposure to VOCs.

Pathway Samples, collected in areas where potential direct conduits were observed that mightprovide a direct route for VOC vapor migration into the building. Examples of these potentialconduits are utilities, cracks in the floor, or open sumps. Results of samples in these areas representlocalized preferential pathways, and are not representative of exposure point concentrations tooccupants. The data collected from these samples are used to evaluate if localized mitigation isnecessary.

Outdoor Samples,col\QCted outside buildings (e.g., at HVAC unit inlets). The results from thesesamples can be compared to those from indoor samples to evaluate the potential contribution ofVOCs from outside air to indoor ah".

Background Outdoors Samplespollected by the RGRP program outdoors at a distance of 0.25to 1.5 miles away from the MEW Site to assess background levels of VOCs.

Quality Assurance Samples, including field duplicates, field blanks, and laboratory controlsamples, collected to maintain an acceptable level of quality assurance.

4. L 6.2 Sampling Procedures

The MEW Companies collected more than 600 indoor, outdoor, and pathway samples from 25buildings located at MEW Companies' former facilities. Locations were finalized on the pre-sampling walk-through with EPA. Sampling was conducted in spring and fall 2003. Twodiscreet sampling rounds were collected in each season at each of the selected locations,separated by a one-week period. The air samples were analyzed by an accredited lab using EPAMethod TO-15 selective ion mode (SIM) for TCE, cis-l,2-DCE, VC, trans-1,2-DCE,chloroform, 1,1-DCE, 1,1-DCA, PCE, Freon 113, 1,1,1-TCA and 1,2-DCB. Before samplingstarted, the laboratory cleaned and certified each canister, with its corresponding flow controllerand filter, to SIM-level reporting limits for the chemicals listed above. Air samples werecollected over a period typical of worker exposure. Some background samples were collectedover a 10-hr period, with others over 12-hr or 24-hr periods.

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4.1.6.3 Evaluation Methodology

The potential public health impacts associated with measured levels of site-related chemicals in airwere evaluated through comparison with three tiers of data and/or criteria:

Tier 1: Site concentrations were compared with local or regional ambient background levels.

Tier 2: Concentrations were compared with Tier 2 acceptable air concentrations proposed forinterim risk management. These values are based on effects other than cancer and are available forboth short- and long-term exposure durations. The proposed Tier 2 values include availableoccupational limits; federal minimal risk levels (MRLs); OEHHA REL levels, and risk-basedconcentrations (RBCs) for occupational settings derived using federal EPA reference concentrations(RfCs) and these values were applied in that hierarchy.

Tier 3: Carcinogenic chemicals were evaluated using risk-specific air concentrations foroccupational settings based on theoretical cancer risks to assess potential alternative mitigationmeasures. One complicating factor for TCE is that EPA's most current cancer risk assessmentremains in draft form and does not recommend an inhalation-specific cancer slope factor. TheEPA's Science Advisory Board review of the draft TCE reassessment has identified severalshortcomings to be addressed, including a number of uncertainties regarding the weight of evidencein data used to derive the proposed slope factors. In addition, the California Department of ToxicSubstances Control (DTSC) and the RWQCB for the San Francisco Bay Region provided directivesin February and March 2003 indicating that the current inhalation carcinogenic slope factor of 0.007(mg/kg-day)"1 will be retained for use in deriving risk based concentrations for use in assessmentsconducted in their jurisdictions.

Given the controversy, a panel of lexicologists retained by the MEW Companies used the mosttechnically supportable available data sets to derive Tier 3, long-term exposure criteria for TCE.These are referred to as the "MEW criteria". In addition, the concentrations were compared to theDTSC/RWQCB criteria, as well as to EPA Region IX's current and the draft provisional criteria.

4.1.6.4 Sampling Results

Reports documenting and interpreting the spring 2003 results were submitted to EPA by each of theMEW Companies (Locus, 2003b&c; Weiss, 2003a; PES, 2003; Geomatrix, 2003; Geosyntec,2003b). Reports documenting the fall results will be available in January 2004. All measuredindoor air concentrations met the criteria except for three buildings where certain indoor TCE airconcentrations were above EPA Region IX's draft provisional values. Mitigation measures arebeing implemented to reduce the concentrations in these buildings. In the fall sampling event,certain buildings showed indoor air concentrations slightly higher than EPA Region IX's draftprovisional value for TCE because these buildings were not ventilated (these buildings were eithervacant or sampled on the weekend). Once the ventilation system was started again, additionalsamples were collected that showed concentrations within all acceptable criteria.

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Certain pathway samples showed concentrations of TCE above EPA Region IX's provisional valueonly. Although exposure to concentrations in pathway samples is typically short and infrequent, ornot feasible (e.g., samples collected in cracks), and although EPA Region IX's draft provisionalvalues are unpromulgated, are subject to change and are under further evaluation by EPA and otheragencies, the MEW Companies implemented voluntary mitigation measures for these locations.Results of mitigation measures are submitted to EPA by each individual company, and the reader isreferred to those reports for additional detail.

4.2. System Operation/Operation & Maintenance

The RGRP program is conducting long-term monitoring, operation and maintenance activitiesaccording to the operation and maintenance (O&M) plan (Locus, 1999 and 2000a). The primaryactivities associated with O&M are the following:

1. Quarterly groundwater elevation measurements in all accessible monitoring wells.Historical water level measurements and hydrographs are included in Appendix A.

2. Groundwater sampling from a network of monitoring wells. Historical water qualityconcentrations from 1986 to the present are included in Appendix B for the chemicalsof concern. Data prior to 1986 can be found in the RI Report (HLA, 1988).

3. Inspection of the conditions of groundwater monitoring and recovery wells.Locations of monitoring and recovery wells for the MEW Site are shown on Figures4-5 to 4-10. Locations of abandoned monitoring wells are shown on Figures 4-11 to4-16. These wells were abandoned with the approval of EPA and in accordance withSCVWD requirements for sealing wells. Wells were sealed either because ofredundancy, because they ceased to serve their remedial investigation purpose, orbecause they interfered with redevelopment of the property on which they werelocated.

4. Inspection and monitoring of the treatment system (a summary of the operations ofthe treatment system is found in Table 4-5).

4.2.1. RGRP Treatment System South of Hwy. 101

The groundwater treatment system for the RGRP south of U.S. Highway 101 began operations inJanuary 1998. It consists of three 10,000-pound liquid-phase granular activated carbon (GAC)vessels arranged in series. Treated groundwater extracted from 10 regional recovery wells isdischarged into the local storm drain under a National Pollutant Discharge Elimination System(NPDES) general permit. Figure 4-1 shows the location of the recovery wells, the treatmentsystem, and the conveyance piping.

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The treatment system has automated components that can be controlled both manually andremotely through computers with dial-up access. The control system consists of a main controlpanel (MCP), pump control panel (PCP), operator interface (site control computer), alarm dialer,and field instrumentation. This control equipment makes remote monitoring, programming anddata downloading possible through a modem connection.

The sediment filter is changed when the differential pressure reaches 10 pounds per square inch(psi). During the filter change, the system is shut down. The filter's inlet and outlet valves areclosed and the drain valve is opened. The filter lid is then opened and the filter cartridge isreplaced. The filters are checked for leaks by closing the outlet valve slowly until a differentialpressure reaches 14 psi or a leak develops. If a leak develops, the wing nuts on the lid aretightened until the leak stops. The system is then restarted. The spent filter is stored in a 55-gallon drum and profiled to determine the proper disposal method.

The effluent of the first GAC vessel is sampled and analyzed monthly to monitor VOCbreakthrough using EPA Method 8260M. Once breakthrough has occurred, the carbon in thefirst vessel is replaced with fresh carbon and placed in the tertiary position. The spent and newcarbon are slurried hi and out from separate truck compartments. Once the carbon change hasbeen completed, the new carbon is soaked for 24 hours prior to restarting the treatment system.System effluent is also sampled and analyzed monthly.

Backflushing of the carbon vessel is performed if excessive back-pressure (15-20 psi) developsacross the filter bed or if preferential flow develops in the bed. This is not performed unless it isabsolutely necessary.

The transfer pump requires lubrication of the motor bearings annually, and the pump is inspectedmonthly for excess vibration, noise, or leakage from the shaft seals. The sump pump requires noregular maintenance. The sump float switch is inspected monthly, and the pump is cycled andtested twice annually to maintain its proper function. A screen over the sump prevents mostdebris from entering, and smaller sediment is removed monthly from the sump to prevent pumpwear and blockage.

4.2.2. RGRP Treatment System North of Hwy. 101

The groundwater treatment system for the RGRP North of U.S. Highway 101 began operation inOctober 1998. The system consists of two low-profile air strippers connected in series. The off-gas from the first air stripper is treated by two 4,000-lb vapor phase GAC vessels before beingdischarged into the atmosphere under a BAAQMD permit, Groundwater from a total of 14regional recovery wells in the "A" and "Bl" aquifers is extracted and treated before it isdischarged into Stevens Creek under the NPDES general permit. Figure 4-2 shows the locationof the recovery wells, the treatment system, and the conveyance piping.

The treatment system has automated components that can be controlled both manually andremotely through computers with dial-up access. The control system consists of a main control

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panel (MCP), pump control panel (PCP), operator interface (site control computer), alarm dialer,and field instrumentation.

The groundwater is filtered before it reaches the treatment units. The sediment filter is changedwhen the differential pressure reaches 10 psi. During the filter change, the system is shut down.The filter's inlet and outlet valves are closed and the drain valve is opened. The filter lid is thenopened and the filter cartridge is replaced. The filters are checked for leaks by closing the outletvalve slowly until the differential pressure reaches 14 psi or a leak develops. If a leak develops,the wing nuts on the lid are tightened until the leak stops. The system is then restarted. The spentfilter is stored in a 55-gallon drum and profiled to determine the proper disposal method.

The vapor phase GAC vessel carbon change occurs based upon a breakthrough, defined as thedetection of the higher of the 10% of the inlet stream concentration to the carbon vessel or 10ppmv as measured a PID or an FID with a carbon filter tip. The spent carbon is vacuumed outfrom the vessel into California Department of Transportation approved containers; then the cleancarbon is loaded from super sacks into the vessel.

Cleaning of the air stripper trays is necessary when there is diminished air flow through the airstripper unit. The gaskets of the air stripper trays are replaced if air leaks between the trays arefound. The blower is inspected monthly for any signs of damage, excessive noise or vibration.

To minimize precipitation of deposits that can reduce air stripper efficiency, an anti-sealant isinjected into the influent prior to treatment. The operation and maintenance of the anti-sealantchemical tank and metering pump require replenishment of the anti-sealant supply and arecommended monthly metering pump calibration.

The pumps selected for the treatment system require little or no maintenance. The transfer pumprequires lubrication of the motor bearings annually, and the pump is inspected periodically forexcess vibration, noise, or leakage from the shaft seals. The sump float switch is inspectedmonthly, and the pump is cycled and tested quarterly to maintain its proper function. A screenover the sump prevents most debris from entering, and smaller sediment is removed periodicallyfrom the sump to prevent pump wear and blockage.

4.2.3. O&M Costs

O&M costs include 1) report preparation for agencies (BAAQMD, RWQCB, EPA), 2) sampling,analysis, and data review (water level monitoring, water quality sampling), 3) groundwatertreatment system O&M (routine tasks for operations and maintenance of the treatment system),and 4) utilities and fees.

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5. PROGRESS SINCE THE LAST FIVE-YEARREVIEW

This is the first five-year review of the site. A two-year evaluation report was submitted to EPAin 2000 and 2001 for the areas south and north of U.S. Highway 101, respectively (Locus, 2000b&2001).

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Locus

6. FIVE-YEAR REVIEW PROCESS

The MEW-Companies were notified of the initiation of the five-year review on 10 October 2003in an email from the EPA remedial project manager, Ms. Alana Lee, entitled "EPA InformationRequest and Notification for MEW Five-Year Review". In that email, EPA stated that thepurpose of the five-year review is to evaluate the implementation and performance of the remedyto determine whether the remedy as currently being implemented is or will be protective ofhuman health and the environment. As part of the five-year review, EPA requested a variety oftypes of data and other information as foundation of the technical assessment of the remedy(Table 1-1). EPA also noted that requests for site inspections and interviews will be conductedseparately as part of the five-year review.

6.1. Community Involvement

Activities to involve the community in the five-year review were initiated by EPA in a meetingin January 2003 between EPA, the MEW Companies, and the public. A notice for the meetingwas sent to newspapers and to about 10,000 addresses in Mountain View. The outcome of theJanuary 2003 meeting was the creation of a Community Advisory Group (CAG), which has metsince January on a monthly schedule.

During the public meetings, representatives of the CAG and local residents expressed concernsabout air strippers that are used at the MEW Site to remediate groundwater. To be responsive to thecommunity's concerns, the RGRP program modified the treatment system south of U.S. Highway101 to eliminate the use of the air stripper and route all water instead to the GAC system fortreatment. Similarly, Fairchild removed the air strippers from operations at its three treatmentsystems, where some RGRP water is also conveyed, and replaced them with GAC systems.

Similar actions were taken by other companies at the MEW Site to remove and replace air stripperswith alternative technologies.

6.2. Document Review

This five-year review has included a review of relevant documents (see References), O&Mrecords, and monitoring data. Applicable groundwater cleanup standards, as listed in the 1989Record of Decision, also were reviewed.

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6.3. Data Review

Groundwater monitoring has been conducted at the MEW Site since the early 1980s. In general,chemicals were detected at their highest concentrations early in the remedial history of the site.These levels have dropped significantly since then because remedial activities have eliminatedsignificant source material. The evaluation of the remedy at the MEW Site was achieved byanalyzing the following indicators:

a Are proper capture zones obtained?

a Are vertical gradients appropriate?

a Are the boundaries of the MEW plume stable or shrinking?

a Are the overall trends in concentrations decreasing?

a Is the dissolved mass of TCE decreasing?

The answers to each of these questions are provided hi the following subsections.

6.3.1. Are Proper Capture Zones Obtained?

Comprehensive water level measurements have been collected quarterly, which has allowed thegeneration of water elevation maps on a semiannual basis, [hi the first year after the startup of theRGRP system in 1998, maps were generated more frequently as shown in Appendix C.] Capturezones were interpolated from water elevation contours by projecting flow lines perpendicular towater elevation contours. After startup of pumping, some flow rates were adjusted to obtain propercapture zones based on the observations from the capture zone maps. The process is iterative. Theinterpolated capture zones are evaluated. If a pumping well does not provide proper capture, thenthe pumping rate is increased. If a capture zone exceeds the design requirements, then the pumpingrate may be reduced. The objective is to optimize the groundwater extraction system to effectivelyremediate the groundwater.

Field measurements of water elevations from monitoring wells reflect the site conditions. Thesedata translate the actual conditions of the aquifer into water elevation data from which waterelevation contours and capture zones are estimated. These estimates are dynamic hi that they reflecthydrological changes in the aquifer (such as seasonal changes hi water elevations and flowdirection, and changes to pumping rates in regional and source control recovery wells).

The water level monitoring network for routine RGRP groundwater elevation measurementsincludes all accessible regional monitoring and recovery wells within the MEW Site (Figures 4-5 to4-10). Water levels in other monitoring wells are also measured by PRPs as specified in theirfacility-specific designs. The data from all measured monitoring wells are combined to provide acomprehensive representation of groundwater conditions.

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SCRWs and RRWs provide adequate capture of the TCE plume, except in the isolated instanceswhen the recovery wells were temporarily off, or have not yet been installed. The discussion belowprovides a description of capture zones estimated from 1998 to 2002 (see Appendix C). The figuresinclude the pumping rates for the RRWs. Pumping rates for SCRWs were not provided hi thefigures until 1999.

6.3.1.1 15 January 1998

The water elevations and estimated capture zones for the 15 January 1998 measurements areshown in Appendix C. The total pumping rate from SCRWs and RRWs was approximately 284gpm: 156, 94, and 34 in the "A", "Bl", and "B2" aquifers, respectively.

Groundwater extraction by the RGRP north of Hwy. 101 did not start until October 1998.Therefore, capture zones north of the highway are not depicted on the map for this period. Also,the following recovery wells were not operated during the 15 January 1998 measurementsbecause of property redevelopment activities:

"A" Aquifer: Wells RW-1A, RW-11A, RW-12A, RW-23A, RW-15A, RW-13A, RW-71 A, RW-26A, RW-2A, RW-24A, RW-18A, RW-7A,RW-5A, and RW-9A

"Bl" Aquifer: Wells RW-10B1, RW-11B1, RW-2B1, RW-7B1, and RW-9B1"B2" Aquifer: Wells RW-1B2, RW-2B2, and RW-9B2"B3" Aquifer: Well65B3"C" and Deep aquifers: DW3 wells

Intel SCRWs PW-2, PW-3, and PW-4 were not operated at that time because of treatment systemcarbon changeout activities.

Even with several recovery wells not operating, the combined groundwater extraction fromSCRWs and RRWs provided acceptable hydraulic capture in the "A", "Bl", and "B2" aquiferssouth of U.S. Highway 101.

The following observations can be made from the 15 January 1998 estimated capture zones:

• The overall capture of the plume in the area south of Hwy. 101 is adequateconsidering that several recovery wells were not operational because ofredevelopment activities.

• The capture zones for the Intel SCRWs are not shown because the wells were notoperating due to carbon changeout activities at the treatment system.

• The capture zones for Fairchild SCRWs in the former Fairchild facilities at 313/323Fairchild Drive and 369/441 N. Whismam Road (Bldgs. 3, 4, 13, and 19 areas) arenot shown because the wells were not operating due to property redevelopmentactivities.

" Capture zones for the "B3" and "C" aquifers are not shown because the wells werenot operating due to property redevelopment activities.

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• A small area just west of Whisman Road is not captured by existing recovery wellssouth of U.S. Highway 101 hi the "A" and "Bl" aquifers. This is partially due to thedevelopment activities in the area that necessitated the shutoff of certain recoverywells. However, it should be noted that since wells REG-2A and REG-5B1 startedoperation hi October 1999, they have provided sufficient capture and remediationfor that area.

6.3.1.2 26 February 1998

The water elevations and estimated capture zones for the 26 February 1998 measurements areshown hi Appendix C. The total pumping rate from SCRWs and RRWs increased to 439 gpm:248,143, and 48 gpm in the "A", "Bl", and "B2" aquifers, respectively.

Groundwater extraction by the RGRP program north of Hwy. 101 did not start until October1998. Therefore, capture zones north of the highway are not depicted on the maps for thisperiod. Also, the following recovery wells were not operated because of property redevelopmentactivities:

"A" Aquifer: Wells RW-5A, RW-7A, RW-9A, RW-18A, and RW-27A"B1" Aquifer: Wells RW-7B1, and RW-9B1"B2" Aquifer: Wells RW-9B2"B3" Aquifer: Well 65B3"C" and Deep aquifers: DW3 wells

Even with several recovery wells not operating, the combined groundwater extraction fromsource control and regional wells provided acceptable hydraulic capture hi the "A", "Bl" and"B2" aquifers. Because of redevelopment activities, water elevations in certain monitoring wellscould not be collected because the monitoring wells were not accessible. Also, water elevationswere not measured at the NEC site.

The following observations can be made from the 26 February 1998 estimated capture zones:

• The overall capture of the plume in the area south of Hwy. 101 is adequate,although some recovery wells were not operational because of redevelopmentactivities.

• The capture zones for Fairchild SCRWs in the former Fairchild facilities at 313/323Fairchild Drive (Bldgs. 3 and 4 areas) are not shown because the wells were notoperating due to property redevelopment activities.

• Capture zones for the "B3" and "C" aquifers are not shown because the wells werenot operating due to property redevelopment activities.

• A small area just west of Whisman Road is not captured by existing recovery wellssouth of Highway 101 in the "A" and "Bl" aquifers. This is partially due to thedevelopment activities in the area that necessitated the shutoff of certain recoverywells. However, it should be noted that since wells REG-2A and REG-5B1 started

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operation hi October 1999, they have provided sufficient capture and remediationfor that area.

• The capture zones for the NEC SCRWs are not shown because water elevationmeasurements were not taken on this date.

*

6.3.1.3 28 May 1998

The water elevations and estimated capture zones for the 28 May 1998 measurements are shownin Appendix C. The total pumping rate from SCRWs and RRWs was approximately 486 gpm:207, 137, 42, 2, and 98 in the "A", "Bl", "B2", "B3", and deeper aquifers, respectively.

Groundwater extraction by the RGRP program north of Hwy. 101 did not start until October1998. Therefore, capture zones north of the highway are not depicted on the maps for thisperiod. Also, the following recovery wells were not operated because of property redevelopmentactivities:

"A" Aquifer: Wells EW-1, RW-5A, RW-7A, RW-9A, RW-18A, andRW-27A

"Bl" Aquifer: Wells RW-7B1, and RW-9B1"B2" Aquifer: Wells RW-9B2

As in February 1998, even with several recovery wells not operating, the combined groundwaterextraction from SCRWs and RRWs provided acceptable hydraulic capture hi the "A", "Bl","B2", "B3", and "C" aquifers. Because of redevelopment activities, water elevations in certainmonitoring wells could not be collected because the monitoring wells were not accessible.

The following observations can be made from the 28 May 1998 estimated capture zones:

• The overall capture of the plume in the area south of Hwy. 101 is adequate,although some recovery wells were not operational because of redevelopmentactivities.

" The capture zone for SMI/Sobrato SCRW EW-1 is not shown because the well wasnot operating due property redevelopment activities.

• The capture zones for Fairchild SCRWs in the former Fan-child facilities at 313/323Fairchild Drive (Bldgs. 3 and 4 areas) are not shown because the wells were notoperating due to property redevelopment activities.

• Because the RRWs hi the "B3", "C", and Deep aquifers had started operations,capture zones for these wells are shown.

• A small area just west of Whisman Road is not captured by existing recovery wellssouth of U.S. Highway 101 in the "A", "Bl", and "B2" aquifers. The same isobserved for an area between REG-3B2 and REG-1B2 east of National Avenue.This is partially due to the development activities in the area that necessitated theshutoff of certain recovery wells. However, it should be noted that since wellsREG-2A and REG-5B1 started operation in October 1999, they have providedsufficient capture and remediation for these areas.

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6.3.1.4 27 August 1998

The water elevations and estimated capture zones for the 27 August 1998 measurements are inAppendix C. The total pumping rate from SCRWs and RRWs was approximately 506 gpm: 228,141, 50, 3,"and 84 gpm hi the "A", "Bl", "B2", "B3", and deeper aquifers, respectively.

Groundwater extraction by the RGRP program north of Hwy. 101 did not start until October1998. Therefore, capture zones north of the highway are not depicted on the maps for thisperiod.

Combined groundwater extraction from source control and regional wells provided adequatehydraulic capture. Because of redevelopment activities, water elevations in certain wells incould not be collected because the monitoring wells were not accessible.

As compared to the 28 May 1998 estimated capture zones, the capture zones have been enhancedafter Fairchild's System 3 at 313/323 Fairchild Drive returned to operation in August 1998, whenredevelopment activities were completed. This is evident from the capture zones depicted forwells RW-9A, RW-9B1, RW-9B2, and RW-7B1.

The following observations can be made from the 27 August 1998 estimated capture zones:

• The overall capture of the plume in the area south of Hwy. 101 is adequate.• A small area just west of Whisman Road is not captured by existing recovery wells

south of U.S. Highway 101 in the "A" and "Bl" aquifers. Wells REG-2A and REG-SB 1 just north of the highway had not started operations as of 27 August 1998.However, since they started operation in October 1999, they have providedsufficient capture and remediation for that area.

6.3.7.5 19 November 1998

The water elevations and estimated capture zones for the 19 November 1998 measurements areshown in Appendix C, including those for the RGRP north of Hwy. 101, which started operatingin October 1998. The total pumping rate from SCRWs and RRWs was approximately 649 gpm:305, 176, 73, 6, and 89 gpm in the "A", "Bl", "B2", "B3", and deeper aquifers, respectively.

Navy wells EA1-1 through EA1-6, and EA2-1 and EA2-2 were not yet in operation.Accordingly, the pumping rate in regional wells REG-6A and REG-9B1, north of Navy Site 9,was limited to 1.5 gpm each to minimize migration of Navy chemicals (especially petroleumhydrocarbons) into the two wells. Figure 1-3 shows the location of Navy Site 9. NASA had notyet started operation of its four recovery wells.

The following observations can be made from the 19 November 1998 estimated capture zones:

• The overall capture of the plume south of the Hwy. 101 is adequate.

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" The capture zone for well REG-2A adequately covers the portion of the plume westof Whisman Road that was not captured on previous dates.

• The eastern portion of the plume in the "A" and the "B1" aquifers north of Hwy. 101was not captured in November 1998 because there was no pumping from the Navywells and limited {Jumping from REG-6A and REG-9A. Also, the NASA wells hadnot been installed at that time. Capture zones were enhanced significantly after theNavy and NASA wells started operations.

6.3.1.6 25 February 1999

The water elevations and estimated capture zones for the 25 February 1999 measurements areshown hi Appendix C. The total pumping rate from SCRWs and RRWs was approximately 692gpm: 329, 227, 54, 6, and 76 gpm in the "A", "Bl", "B2", "B3", and deeper aquifers,respectively. Navy SCRWs were in operation during this water level monitoring event, exceptfor Navy wells EA1-4, EA2-1, and EA2-2. NASA had not yet started operation of its fourrecovery wells.


• The overall capture of the plume is adequate.• A small area with low concentrations on the west of the "A/A1" plume, near well

W89-9, is not within the interpolated capture zones. This was addressed afterNASA wells started operations.

• A significant area of Navy Site 9 is not within the capture zone hi the "B1/A2"aquifer (largely because Navy wells EA2-1 and EA2-2 were not operating).

6.3.17 27 May 1999

The water elevations and estimated capture zones for the 27 May 1999 measurements are shownhi Appendix C. The total pumping rate from SCRWs and RRWs was approximately 679 gpm:325, 229, 48, 6, and 71 gpm in the "A", "Bl", "B2", "B3", and deeper aquifers, respectively.Navy SCRWs, with the exception of Navy wells EA1-1 and EA1-6, were in operation during thiswater level monitoring event. NASA had not yet started operation of its four recovery wells.

Combined groundwater extraction from source control and regional wells appears to provideadequate hydraulic capture. The following observations can be made from the 27 May 1999estimated capture zones:

• The overall capture of the plume is adequate in the "A/A1" aquifer, except for asmall area with low concentrations just north of REG-6A and EA1-4, which is notwithin the depicted capture zone. This was addressed after NASA wells startedoperating.

• The overall capture zone in the "B1/A2" aquifer is adequate, except for a small areain the eastern portion of Navy Site 9. The Navy will be installing a recovery well inthe area to address this issue (Navy, 2003).

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» Capture zones for wells EW-1, EW-2, EW-3, and EW-4 are not shown becausewater elevations were not measured in these wells.

6.3.1.8 18 November 1999i

The water "elevations and estimated capture zones for the 18 November 1999 measurements areshown in Appendix C. The total pumping rate from SCRWs and RRWs was approximately 612gpm: 290, 204, 43, 6, and 69 gpm in the "A", "Bl", "B2", "B3", and deeper aquifers,respectively. The Navy recovery wells were off during this water level monitoring event. As aresult, the capture zones for this monitoring period were not adequate. Also, NASA had not yetstarted operation of its four recovery wells.


• The overall capture of the plume south of the highway is adequate.» RW-1B2 was not pumping, due to redevelopment activities in the area.• Overall capture of the plume in the area north of the highway was not adequate

because Navy wells were temporarily off, and NASA had not started operation of itsrecovery wells.

6.3.1.9 25May 2000

The water elevations and estimated capture zones for the 25 May 2000 measurements are shown inAppendix C. The total pumping rate from SCRWs and RRWs was approximately 714 gpm: 347,237, 45, 6, and 79 gpm in the "A", "Bl", "B2", "B3", and deeper aquifers, respectively.

Because of development activities at 515/545 N. Whisman Road, treatment System 1 and itsassociated wells (AE-RW-9-1, AE-RW-9-2, RW-3A, RW-4A, RW-16A, RW-20A, RW-21A,RW-25A, RW-3B1, RW-4B1, RW-3B2, RW-4B2, and 38B2) were off during this period. Also,because of development activities at 350 Ellis Street, certain recovery wells were off in that area(RE-23A, RE-24A, RE-25A). NASA had not yet started operation of its four recovery wells.


• Although several wells were off, overall capture south of Hwy 101 is adequate.• The overall capture of the plume north of the highway is adequate in the "A/A1"

aquifer except for a small area with low concentrations just north of REG-6A andEA1-4, which is not within the depicted capture zone. This was addressed afterNASA wells started operating.

• The overall capture zone in the "B1/A2" aquifer is adequate, except for a small areain the eastern portion of Navy Site 9. The Navy will be installing a recovery well inthe area to address this issue (Navy, 2003).

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6.3.1.10 16 November 2000

The water elevations and estimated capture zones for the 16 November 2000 measurements areshown in Appendix C. The total pumping rate from SCRWs and RRWs was approximately 733gpm: 344,251, 57,6, and 75 gpm in the "A", "Bl", "B2", "B3", and deeper aquifers, respectively.

*

The Navy wells in the "A" aquifer were off temporarily during this water level monitoring event.Also, NASA had not yet started operating its four recovery wells. The following observations canbe made from the 16 November 2000 estimated capture zones:

• A large area of Navy Site 9 is not within the capture zone because the Navy wellswere not operating. In addition, a small area just north of REG-6A and EA1-4, withlow concentrations, is not within the depicted capture zone. This was addressedafter NASA wells started operations.

• The overall capture zone in the "B1/A2" aquifer is adequate, except for a small areahi the eastern portion of Navy Site 9. The Navy will be installing a recovery well hithe area to address this issue (Navy, 2003).

6.3.1.11 24 May 2001

The water elevations and estimated capture zones for the 24 May 2001 measurements are shown hiAppendix C. The total pumping rate from SCRWs and RRWs was approximately 618 gpm: 313,204, 30, 6.5, and 64 gpm in the "A", "Bl", "B2", "B3", and deeper aquifers, respectively.

The Navy wells in the "A" aquifer were off temporarily during this water level monitoring event.Also, NASA had not yet started operating its four recovery wells. The following observations canbe made from the 24 May 2001 estimated capture zones:

• Overall capture is adequate south of Hwy 101.• A large area of Navy Site 9 is not within the capture zone because the Navy wells

were temporarily off. In addition, a small area just north of REG-6A and EA1-4,with low concentrations, is not within the depicted capture zone. This wasaddressed after NASA wells started operation.

6.3.1.12 15 November 2001

The water elevations and estimated capture zones for the 15 November 2001 measurements areshown in Appendix C. The total pumping rate from SCRWs and RRWs was approximately 689gpm: 403, 213, 37,4, and 32 gpm in the "A", "Bl", "B2", "B3", and deeper aquifers, respectively.Because they reached groundwater cleanup standards specified hi the ROD, recovery wells DW3-219 and DW3-505R were shut down. RW-13B1 was off for maintenance. By this monitoringperiod, the NASA recovery wells had started operating.


" Overall capture is adequate south of Hwy 101.

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• Overall capture is adequate north of Hwy 101. With the NASA wells in operation,the small area just north of REG-6A and EA1-4 is adequately captured.

6.3.1.23 23 May 2002

The water elevations and estimated capture zones for the 23 May 2002 measurements are shown inAppendix C. The total pumping rate from SCRWs and RRWs was approximately 685 gpm: 394,219, 35, 7, and 30 gpm in the "A", "Bl", "B2", "B3", and deeper aquifers, respectively. Becausethey had achieved groundwater cleanup standards specified hi the ROD, recovery wells DW3-219and DW3-505R were shut down.


• Overall capture is adequate south of Hwy 101.• Overall capture is adequate north of Hwy 101, except for a small area in the eastern

portion of Navy Site 9. The Navy will be installing a recovery well in the area toaddress this issue (Navy, 2003).

6.3.1.14 21 November 2002

The water elevations and estimated capture zones for the 21 November 2002 measurements areshown in Appendix C. The total pumping rate from SCRWs and RRWs was approximately 666gpm: 374,221, 33, 6, and 30 gpm in the "A", "Bl", "B2", "B3", and deeper aquifers, respectively.Because they had achieved groundwater cleanup standards specified in the ROD, recovery wellsDW3-219 and DW3-505R remained shut down. NASA-2A and RW-13B1 were off formaintenance.


• Overall capture is adequate south of Hwy 101.• Overall capture is adequate north of Hwy 101, except for a small area in the eastern

portion of Navy Site 9. The Navy will be installing a recovery well in the area toaddress this issue (Navy, 2003). Also, a small area north of EA1-4 with lowconcentrations was not captured, mainly because NASA-2A was off.

6.3.1.15 Summary

In summary, the examination of estimated capture zones since the start of the RGRP have shownthat the capture zones are fairly uniform. SCRWs and RRWs provide adequate capture of theTCE plume, except hi isolated instances when the wells were temporarily off, or have not yetbeen installed.

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6.3.2. Are Vertical Gradients Appropriate?

The direction of the vertical gradient across aquitards can be determined for each date on whichwater level measurements were taken. For each aquitard, nearby pairs of wells were identified forwhich one well is in the aquifer above the aquitard and one is hi the aquifer below the aquitard. Thedifference in the water elevations in these two wells can be used to determine the direction of thevertical gradient across the aquitard. Ideally, upward gradients across fee aquitards are desired in agroundwater extraction program. However, in several locations, the concentrations in the loweraquifer are higher than the concentrations in the upper aquifer, so mauitaining upward gradients isnot critical in these areas. This is especially the case between in the "A" and the "Bl" aquifers.

The directions of the vertical gradients are presented in Appendix D. The direction was determinedacross the "A/B1","B1/B2", "B2/B3", and "B3/C" aquitards.

6.3.2.1 "A/B1"Aquitard

Appendix D shows thedifference in water elevationsbetween the "Bl" and "A"aquifers. A total of 55 well pahsare used to monitor the verticalgradient across this aquitard.From 1996 to 2003, the averagevertical difference in waterelevation across this aquitard isupward and has ranged from+0.31 to +0.63 feet. Althoughthe average gradient is upward,there are specific locationswhere downward gradients areobserved. Examination of these downward gradients shows that they do adversely impact theremedial programs at the MEW Site (Locus, 2000b & 2001). These locations are typically nearpumping wells hi the "Bl" aquifer, where there are no pumping wells hi the "Al" aquifer, or hiareas where concentrations in the "Bl" aquifer are higher or similar to those in the "A" aquifer.

Year

19961997199819992000200120022003

No. of Well Pairs

Average WL Difference* Across Aquitard (ft)

|_ A/B1

0.510.630.620.310.550.480.490.49

55

B1/B2

2.11.421.561.521.521.61.882.16

28

B2/B3

6.947.699.5210.19.1110.018.238.14

16

B/C

6.5714.7111.3610.2211.2811.0713.545.6

3

6.3.2.2 "B1/B2"Aquitard

To monitor the direction of the vertical gradient across the "B1/B2" aquitard, 28 well pairs are used.The vertical gradient across this aquitard is generally upward. For the water elevation measurementevents since 1996, the average vertical difference in water elevations has ranged from +1.42 to+2.16 feet. There are specific locations where downward gradients are observed, but these gradientsdo not adversely impact the remedial programs at the MEW Site (Locus, 2000b & 2001).

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AVERAGE WL DIFFERENCE ACROSS AQUITARDS

MIDDLEFIELD-ELLIS-WHISMAN SITE

1996 1997 1998 1999

Positive values (> 0) indicate upward gradients. YEAR

2000 2001 2002 2003

6.3.2.3 "B2/JS3" Aquitard

For this aquitard, data sets are available from 16 pairs. All observed vertical gradients across thisaquitard are upward. The average vertical difference in water elevations between 1996 and 2003ranged from +6.94 to +10.10 feet.

6.3.2.4 "B/C"Aquitard

For this aquitard, data sets are available from two pairs. All observed vertical gradients acrossthis aquitard are upward. The average vertical difference in water elevations from 1996 to 2003ranged from +5.60 to +14.71 feet.

6.3.3. A re the boundaries of the MEW plume stable or shrinking?

This section compares the present and historical MEW plume boundaries to identify temporal andspatial changes resulting from the remedial activities. Because the Plume Definition Program(Canonie, 1993k) confirmed that all other VOC plumes at the site are contained within theboundaries of the TCE plume, plume boundaries are defined by the 0.005 mg/L TCE concentrationcontours. TCE contour maps prepared with data from the 1992 plume definition, 1997 baseline,and the subsequent annual sampling events from 1998 to 2002 (Appendix E) were used to identifyplume boundary changes in the "A", "Bl", "B2", "B3", and "C" and Deep aquifers.

6.3.3J "A" Aquifer

Remedial activities at the MEW Site have resulted in significant decreases in TCE and otherchemicals in the groundwater. The "A" aquifer plume boundaries have remained stable since the1992 plume definition event. The following notable concentration variations resulted in minorchanges in the representation of the main "A" aquifer plume boundary:

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North of U.S. Highway 101

TCE concentrations in wells located hi the northeast area of the plume near Hangar 1have decreased significantly since the initial plume definition event hi 1992, allowingthe plume boundary to contract in this area. During the 1992 event, wells W9-45 and WU4-25 were found to have concentrations of 1.9 and 0.045 mg/L,respectively. By 2002, concentrations have decreased to 0.41 mg/L in well W9-45, and0.002 mg/L hi well WU4-25. The 0.005 mg/L contour was shifted west to account forthese variations.From 1992 to 1997, approximately 15 monitoring wells were installed hi the area of theNavy warehouse, directly north of the MEW plume. Concentrations during the baselineevent ranged from less than 0.001 mg/L to 0.099 mg/L. Since 1997, TCEconcentrations have dropped, mostly due to the start of RGRP groundwater extraction inOctober 1998 and the NASA groundwater extraction program in 2001. By 2002,concentrations ranged from non-detect to 0.036 mg/L, with several wells havingconcentrations below the detection limit of 0.001 mg/L.The 0.005 mg/L contour on the northeast end of the NASA plume has contracted. TCEin 11M03A decreased from 0.092 mg/L in 1992 to 0.018 mg/L in 1997, and then to0.012 mg/L in 2002.New data collected by NASA and the Navy revealed the presence of a plume in theOrion Park area west of the MEW plume. This area is being investigated by the Navy.

South of U.S. Highway 101;

• Since it was reported as non-detectable in 1992, TCE was subsequently detected in WellR24A with a most recent concentration of 0.019 mg/L hi 2002. The origin of theconcentrations at the well is not known, but it is not likely that the concentrations at thewell can be attributed to MEW chemicals because the well is south (upgradient) of theMEW Site and the groundwater flows to the north.

• The 1992,1997, and 1998 TCE contour maps show the eastern plume boundary south ofHighway 101 defined west of well R30A. R30A was sealed in 1998 during constructionactivities for the light-rail system, and a replacement well, 162A, was installed in 1999.Well 162A showed 0.0074 mg/L in 2002. The plume boundary in this area was just eastof well 162A.

6.3.3.2 "Bl" Aquifer

The "Bl" aquifer plume has shown slight constriction along the eastern boundary but has otherwiseremained stable since 1992.

6.3.3.3 "B2" Aquifer

South of the highway, the "B2" aquifer plume has constricted along the northwestern and easternboundaries as a result of reduced concentrations and a more developed monitoring network. The

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7

northwest boundary of the plume has retreated slightly since the 1992 and 1997 monitoring eventsdue to reduced concentrations at well 11B2. The eastern MEW plume boundary in the "B2" aquiferhas been more clearly defined since the 1992 contours were presented. The addition of wellsR58B2, R68B2, and R70B2 to the monitoring network has identified a low-concentration zoneextending from Ellis Street to well 42B2. This zone was most likely present during the 1992 event,although groundwater samples were not available to define it.

Furthermore, the southwestern plume boundary is shown to have retreated slightly on the 1998 and1999 contour maps due to non-detectable concentrations hi well 129B2, which was not sampledduring the 1992 or 1997 events. TCE concentrations hi this well, however, have been historicallylow since non-detectable values at 0.0005 mg/L were reported in 1985, and it is likely that theexpanded southwestern boundary seen on the 1992 and 1997 contour maps is exaggerated. In 2002,Well IM10B2 south of Middlefield Road showed TCE concentrations of 0.92 mg/L. Theseconcentrations, however, are not consistent with historical measurements.

North of Hwy. 101, concentrations hi the "B2" aquifer have been measured sporadically in well51B2, but since 2001, TCE has not been detected at concentrations higher than ROD cleanupstandards.

6.3.3.4 "BS" Aquifer

Two distinct "B3" aquifer plumes have been depicted surrounding wells R54B3 and 44B3.Concentrations hi the "B3" aquifer historically have been isolated. Significant TCE concentrationreductions at wells R54B3 and 44B3 since the 1992 sampling event suggest the likelihood of plumecontraction. At well R54B3, concentrations have decreased from 0.16 mg/L hi 1992 to non-detectable at 0.0005 mg/L. Similarly, well 44B3 has seen a decrease in TCE concentrations from0.012 mg/L hi 1992 to 0.0007 mg/L in 2002. Concentrations at well 65B3 have fluctuated between0.0093 mg/L in 1992 to 0.031 mg/L in 1997. Since 1997, a decreasing trend has been observed hi65B3 since the well started operations. By 2002 the concentration in the well has decreased to0.0068 mg/L, just slightly above the ROD cleanup standard of 0.005 mg/L.

6.3.3.5 "C" and Deep Aquifer

Two distinct plumes have been depicted in the "C" and Deep aquifers. A western plume is definedby wells 8C and RW-1C (Silva Well Program) and an eastern plume is present at the DW3 deepwell cluster. Decreasing concentrations in the DW3 wells suggest that plumes in this area arecontracting. In fact, the more stringent cleanup standard (0.0008 mg/L instead of the MCL of 0.005mg/L) has already been achieved hi the "C" aquifer at this location.

6.3.4. Are the Overall Trends in Concentrations Decreasing?

A concentration trend analysis was performed for TCE. Influent data from treatment systemsindicate that TCE comprises the majority of the chemical mass being treated (see Section 6.3.5).Therefore, because TCE remains the indicator compound for the MEW Site, a trend analysis forTCE provides a good indication of the performance of the remedial actions.

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Appendix B contains a listing of the concentrations of the 15 chemicals of concern identified in theCD. The results of the Plume Definition Program (Canonie, 1993k) confirmed that 10 organicchemicals are the only chemicals that require routine monitoring. The eleventh organic chemical,phenol, was not detected above the 0.3 mg/L criterion for phenol specified in the Plume DefinitionProgram in any of the samples tested for that compound. Appendix E shows a series of TCEconcentration maps for the MEW Site for shallow and deep aquifers.

A trend hi TCE concentrations was estimated using the following process:

1. Identify RGRP wells in each aquifer2. Calculate the annual average of the TCE concentration for each well in each aquifer3. From the average of each well, calculate the annual average for each aquifer.

Appendix B lists individual well concentrations. A regular sampling network was not establisheduntil 1997. Therefore, not all wells have been sampled at each event. Table 6-1 provides acomparison of the average for the areas north and south of Hwy. 101 based on available data.

Groundwater monitoring has been conducted at the MEW Site since the early 1980s. In general,most concentrations were detected at their highest levels early in the investigation and remedialprograms. These levels have been reduced significantly by the combined source control andregional remedial measures that have contained and removed sources in the groundwater and havecleaned up the unsaturated soils.

The average concentrations in 2002 were compared to RI/FS conditions (1986/1987) and to 1992conditions when data were available. The average 2002 concentrations were also compared toconditions just before the RGRP started south of the highway (1997 concentrations) and north of thehighway (1998 concentrations).

"A" Aquifer: By 2002, theTCE concentrations in thearea south of Highway 101have decreased 87% and72% compared to 1992 and1997 conditions. North ofthe highway, the concent-rations decreased by 37%and 39% as compared to1992 and 1998 conditions.

Area/Aquifer

A Aquifer SI 01

A Aquifer N101

Bl Aquifer S101

Bl Aquifer N101

B2 Aquifer

B3 Aquifer

C&Deep Aquifer

20027(1986&1987)

-39%

1260%

-91%

200271992

-87%

-37%

-87%

-65%

19%-33%

-83%

200271997

-72%

-57%

-40%

-78%

200271998

-39%

-29%

-75%

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"Bl" Aquifer: By 2002, the TCE concentrations in the area south of Highway 101 have decreased87% and 57% compared to 1992 and 1997 conditions. North of the highway, the concentrationsdecreased by 65% and 29% as compared to 1992 and 1998 conditions.

"B2" Aquifer: By 2002, the -TCE concentrations decreased 40% compared to 1997. Whencompared to 1992, the average concentrations increased by 19%. This average, however, is highlyinfluenced by concentrations in one well, 36B2 (see Table 6-1F) where the concentrations causefluctuations hi the average. As compared to 1986/1987 levels, the average concentrations decreasedby 39%.

"B3" Aquifer: Only one well (65B3) currently shows concentrations in the "B3" aquifer that wouldrequire remedial action. In the early part of the investigation, the well showed nondetectableconcentrations, but the concentrations later increased. Accordingly, the RGRP program installed apump in the well and started extraction in 1997. The pumping resulted in a decrease of 78% in2002 as compared to pre-pumping conditions in 1997.

"C" and Deep Aquifers: The RGRP Program pumps groundwater from the DW3 cluster of wells,the only location where TCE was detected in the MEW Site above cleanup standards established hithe ROD. By 2002, pumping from the wells resulted hi a significant decrease in concentrations of91%, 83%, and 75% as compared to 1986/1987,1992, and 1998 conditions, respectively.

Perhaps the best example to demonstrate reductions in the concentrations is a side-by-sidecomparison of two plume conditions: 1992 and 2001. Darker colors on these maps indicate higherconcentrations. Observation of the two maps shows that by 2001 the darker colors of the 10 and 1mg/L contours have virtually disappeared in the area south of Hwy 101. North of the highway, thearea of the 1 mg/L contours has been greatly reduced. These significant reductions are the result ofthe remedial measures implemented at the MEW Site.

No potentially toxic or mobile transformation products have been identified during samplingevents that were not already present at the time of the ROD. Therefore the cleanup goalsspecified in the ROD remain the same.

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1992

2001

TCECONCENTRVnON

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6.3.5. Is the dissolved mass of TCE decreasing?

An estimate of the mass of dissolved TCE was performed for each sampling event for which a TCEconcentration contour map can be drawn: 1992, 1997, 1998, 1999, 2000, 2001, and 2002. TCEcontour maps are shown hi Appendix E. The 1997 sampling event was conducted before start ofoperations of the RGRP program, but some source control mitigation measures had begun before1997.

The mass of TCE is estimated by multiplying the volume of water (Fw) by the concentration of TCEin the water.

... (1)

The volume of water within the contour, Vw, can be estimated with the following equation:

n ...(2)

Where A is the area within the contour, D is the average saturated thickness of the aquifer, and n isthe average porosity of the aquifer. Both the saturated thickness and porosity of each aquifer arehighly variable at the MEW site. For these comparative calculations, constant, average values wereused. These values were obtained from the Revised Final Design for the Regional GroundwaterRemediation Program. (Smith, 1996a&b). Thickness values were estimated as the average of therninirnuni and maximum values observed at the site.

To calculate the volume of water, the area within each TCE concentration contour is estimated.These contours are shown hi Appendix E. On certain figures, "depressions" were drawn aroundcertain wells where the concentration was below the value of the contour. The areas of thedepressions were subtracted from the area within the contour.

The geometric mean of the well concentrations within the contour is used to provide arepresentative average value for the concentration of TCE within the contour. The geometric meanis used because the concentrations show significant variations within each area, and the geometricmean provides a reasonable representation of the overall concentration values. Where there are nosampled wells within the area to provide a concentration estimate, the concentration of a nearby areawith the same contour value is used for the concentration estimate.

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Contours are typically "nested", that is, there are contours within other contours. This occurswherever there are contours above the lowest level. For the inner area, it is not the concentrationitself that is multiplied by the volume of water, but the increase in concentration above the lowerlevel. This is demonstrated with the example below:

Area within contour = 100 m2

Geometric mean of well concentrations = 0.002 g/m3

Thickness = 1 mPorosity = 0.5TCE Mass = (100 m2) x (0.002 g/m3) x (1 m) x (0.5)

= 0.1g

Area within contour = 20 m2

Geometric mean of well concentrations = 0.03 g/mThickness = 1 mPorosity = 0.5TCE Mass= (20 m2)x (0.03 g/m3 - 0.002 g/m3)x (1 m) x (0.5)

= 0.28 g

The total mass of TCE in the above example is 0.38 grams. The concentration within the lowestcontour is subtracted in the formula so that the area below the upper contour is not added twice.Therefore, a term ACrcE is shown in Equation (1), indicating an incremental concentration (e.g.AC-TCE = 0.03 g/m3 - 0.002 g/m3 in the example above).

After the mass of TCE within each contour is calculated, the masses are added together to obtain thetotal mass of TCE in the aquifer for that sampling event.

These calculations are shown hi Appendix F. The mass within each plume is calculatedindividually, and then the masses are added together. For depressions, the result of thiscalculation is a negative number, because it is an area that should be subtracted from the areaaround it. This has the same effect as subtracting the depression area from the area of thesurrounding contour.

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Aquifer

"A""Bl""B2""B3"

"C" and Deep

Mass of Dissolved TCE (kg)

1992

2085

75323230.24

0.16

Total 1 9939

1997

1219

3562233

0.026

0.084

5014

1998

824' 2751

1320.0088

0.047

3707

1999

6942050310

0.0045

0.012

3054

2000

5601773145

0.0030

0.0021

2478

2001

5191694146

0.0020

0.0018

2359

2002

5391720106

0.0021

0.0022

% Change

2002/1992

-74%

-77%-67%-99%

-99%

2365 |] -76%

2002/1997

-56%

-52%-55%-92%

-97%

-53%

The table above summarizes the mass calculations for the seven sampling events. It is important tonote that these values include only dissolved TCE. TCE that is volatilized into the gas phase,sorbed to soil grains, or possibly present as a dense non-aqueous phase liquid is not included hi thecalculations. Thus, the values reported may be lower than the total mass of TCE in the aquifers, butmay be validly compared to one another in a trend analysis.

As the table indicates, the mass is decreasing. By 2002, the dissolved TCE mass in the plume hasdecreased by 76% as compared to 1992, and by 53% as compared to 1997. Detailed tables of thecalculations are provided in Appendix F.

"A" Aquifer: By 2002, the dissolved TCE mass hi the "A" aquifer has decreased by 74% ascompared to 1992, and by 56% as compared to 1997.

"Bl" Aquifer: By 2002, the dissolved TCE mass hi the "Bl" aquifer has decreased by 77% ascompared to 1992, and by 52% as compared to 1997.

"B2" Aquifer: By 2002, the dissolved TCE mass in the "B2" aquifer has decreased by 67% ascompared to 1992, and by 55% as compared to 1997.

"B3" Aquifer: By 2002, the dissolved TCE mass in the "B3" aquifer has decreased by 99% ascompared to 1992, and by 92% as compared to 1997.

"C" and Deep Aquifer: By 2002, the dissolved TCE mass in the "C" and Deep aquifers hasdecreased by 99% as compared to 1992, and by 97% as compared to 1997.

Because of its success hi removing mass, the RGRP VOC removal rate South of U.S. Highway 101has declined slightly since extraction began in 1998. As of September 2003, the RGRP S101treatment system has removed a total of 2,183 kg of VOCs, of which 2,040 kg (93%) are TCE(Table 6-2). The current removal rate is approximately 20 to 30 kg per month. Cumulative massremoval for this treatment system was linear through early 2001, but has since been declining due todecreasing groundwater concentrations.

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MASS REMOVAL PER MONTH - RGRP SOUTH OF HWY 101MIDDLEFIELD-ELLIS-WHISMAN SITE

1998 2003 2004

CUMULATIVE MASS REMOVAL - RGRP SOUTH OF HWY 101MIDDLEFIELD-ELLIS-WHISMAN SITE

2,500

2003

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MASS REMOVAL PER MONTH - RGRP NORTH OF HWY 101MIDDLEFIELD-ELLIS-WHISMAN SITE

60

1998 2003

CUMULATIVE MASS REMOVAL - RGRP NORTH OF HWY 101


2,500

1998 2003

As of September 2003, the RGRP treatment system North of Hwy. 101 has removed a total of 2,198kg of VOCs, of which 1,876 kg (85%) are TCE (Table 6-2). The current total VOC removal rate is

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approximately 30 to 35 kg per month. Cumulative mass removal for this treatment systemcontinues to be linear.

To conclude, the overall mass calculations indicate that the combined operation of the RGRP andsource control remedial systems-at the MEW Site is effective in removing chemicals at the MEWSite.

6.3.6. Summary of Data Review

The table below provides a summary of each of the evaluation indicators

Indicator

Are proper capture zones obtained?

Are vertical gradients appropriate?

Are the boundaries of the MEW plume stable or shrinking?

Are the overall trends in concentrations decreasing?

Is the dissolved mass of TCE decreasing?

YES/NO

YES

YES

YES

YES

YES

6.3.7. Interviews

It is our understanding that EPA will be conducting interviews of interested parties hi connectionwith this five-year review. The following persons can be contacted by EPA to answer questionsthat EPA may have regarding the five-year review or the operations of the RGRP program.

Name

Mr. Cliff Kirchof

Mr. Elie Haddad

Mr. Fred Banker

Ms. Maile Smith

Company

Schlumberger (for Fairchild)

Locus Technologies

RMT, Inc.

Weiss Associates

Phone

281-258-8298

650-960-1640

650-926-9832

650-968-7000

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1. TECHNICAL ASSESSMENT

This chapter assesses the effectiveness of the implemented remedies. In accordance with theEPA guidance for preparing five-year reviews (EPA, 2001), this chapter answers three questions:

A Is the remedy functioning as intended by the decision document?B. Are the exposure assumptions, toxicity data, cleanup levels, and remedial action

objectives (RAOs) used at the time of remedy selection still valid?C. Has any other information come to light that could call into question the protectiveness of

the remedy?

7.1. Question A: Is the Remedy Functioning as Intended by theDecision Document?

The Feasibility Study (Canonie, 1988) for the MEW Site lists the RAOs to be:

1. Protection of potential potable water supplies;2. Remediation or control of relatively elevated concentrations of chemicals present in

localized vadose zone soils below the ground surface that could migrate into the shallowgroundwater system;

3. Remediation or control of groundwater containing elevated concentrations of chemicals,including control of discharge of such groundwater into surface water.

Extensive remedial measures have been implemented at the MEW Site by the MEW Companies,and by the RGRP program to clean up the shallow aquifer zone. The review of documents,ARARs, risk assumptions, and the results of the site inspections all indicate that the remedy isfunctioning as intended by the ROD, as modified by the ESD. The soil remedial measures thatincluded SVE systems and soil excavations (Figure 4-3) achieved soil cleanup goals byremediating chemicals present hi the vadose soils. The installation of four slurry wallseffectively isolated source areas and, combined with groundwater extraction and treatment,resulted hi a significant decrease in concentrations in the areas within and outside the slurrywalls. Pumping activities inside and outside the slurry walls achieved the third RAO bycontrolling sources and remediating the groundwater.

Although the RGRP treatment system south of Hwy. 101 was modified in 2003 to result invirtually zero air emissions, the groundwater pump-and-treat remedy has functioned well asintended. The treatment system was modified in the fall of 2003 to remove the air stripper androute all groundwater to the existing tertiary carbon adsorption system. This modificationresulted in virtually zero air emissions from the treatment system. Other than that, there were noopportunities for system optimization during this review.

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The monitoring well network provides sufficient data to assess the progress of the remediation.In November 2003, a proposal was submitted to EPA to reduce the frequency of readings ofwater elevations measurements from quarterly to semiannually (Weiss, 2003b).

The ROD for the MEW Site defines cleanup goals for the soils and groundwater. The followingtable is a summary of the status of these goals at the MEW Site.

Area

RGRPS101

RGRPN101

Remedial Action

GW Extraction,Soil VaporExtraction, SlurryWall SoilExcavation,Permanganate

GW Extraction

SoilCle&nup

GoalsAchieved?

YES

YES

GroundwaterMCLs

Achieved?

Achieved intwo Deepaquifers.Others are inprogress

In progress

Comments

Soil remediation south of 101 was performed byindividual MEW Companies. Soil cleanup levelsestablished in the ROD have been achieved

In the groundwater, the plume is contained and thegroundwater concentrations have been significantlyreduced, and continue to be reduced.

Concentrations in soil tested by the RGRP north of 101were found to be within ROD objectives; excavationand treatment were not necessary.

In the groundwater, the plume is contained and thegroundwater concentrations have been significantlyreduced, and continue to be reduced.

7.2. Question B: Are the Exposure Assumptions, Toxicity Data,Cleanup Levels, and Remedial Action Objectives (RAOs) Used atthe Time of Remedy Selection Still Valid?

This section discusses changes in standards to be considered, and changes hi exposure pathways,toxicity, and other chemical characteristics.

7.2.1. Changes in Standards To Be Considered

As the remedial work progressed, the ARARs for soils specified in the ROD have been met.ARARs that still must be met at this time and that have been evaluated include: the SafeDrinking Water Act (40 CFR 141.11-141.16) from which many of the groundwater cleanuplevels were derived. A list of ARARs is included in Appendix G. There have been no changes inthese ARARs affecting the operation of the RGRP treatment systems, and no new standards or"To Be Considered" (TBCs) affecting the protectiveness of the remedy.

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In 2000, EPA promulgated the California Toxics Rule (CTR), which updates and adds standardsfor discharges to surface waters. The CTR standards for VOCs are not lower than those in theNPDES permit for the RGRP systems. Therefore, these new standards do not affect the NPDESdischarge standards for RGRB treated effluent, and do not affect the protectiveness of theremedy.

7.2.2. Changes in Exposure Pathways, Toxicity, and Other Contaminant Characteristics

Except for a potential change in the inhalation toxicity factor for TCE, there have been nochanges hi the toxicity factors for the contaminants of concern that were used in theendangerment assessment for the MEW Site (ICF-Clement, 1988), or in the various riskassessments that were performed as part of redevelopment of properties at the MEW Site (Smith,1997; Locus, 1997, and HLA, 1999). The assumptions considered in the risk assessments areconservative and reasonable in evaluating risk. No change to these assumptions, or the cleanuplevels for groundwater or soil is warranted. There has been no change to the standardized riskassessment methodology that could affect the protectiveness of the remedy.

A complicating factor for TCE is that EPA's draft cancer risk assessment for inhalation does notrecommend an inhalation-specific cancer slope factor. Additionally, the cancer slope factor is aprovisional value that has not been promulgated. The EPA's Science Advisory Board review of thedraft TCE reassessment has identified several shortcomings to be addressed, including a number ofuncertainties regarding the weight of evidence in data used to derive the proposed slope factors. Inaddition, DTSC and the RWQCB for the San Francisco Bay Region provided directives hi Februaryand March 2003 indicating that the current inhalation carcinogenic slope factor of 0.007 (mg/kg-day)~! will be retained for use in deriving risk based concentrations for use in assessmentsconducted in their jurisdictions.

On 3 October 2002, the EPA requested a work plan "to conduct a human health risk assessmentto evaluate the groundwater-to-indoor air exposure pathway by collecting indoor air, outdoor air,and soil gas samples at each Facility." In response, the MEW Companies submitted a unifiedwork plan on 2 December 2002 (Locus, 2002), and a revision on 16 April 2003 (Locus, 2003a)responding to EPA's 17 February 2003 comments. NEC chose to submit its own work plan,which was similar to the unified work plan. The results of the spring sampling event weresubmitted to EPA by each of the MEW Companies (Locus, 2003b&c; Weiss, 2003a; PES, 2003;Geomatrix, 2003; Geosyntec, 2003b). The results of the fall sampling event will be submitted toEPA in January 2004.

The MEW Companies collected more than 600 indoor, outdoor, and pathway samples from 25buildings located at MEW Companies' former facilities. Sampling was conducted in spring and fall2003. Two discreet sampling rounds were collected in each season at each of the selected locations,separated by a one-week period. Air samples were collected over a period typical of workerexposure. Some samples were collected over a 10-hr period, the others over a 12-hr or 24-hr period,hi addition, outdoor samples were collected around the MEW Site up to 1.5 miles away from the

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site.

Outdoor samples collected outside the MEW Site met all evaluation criteria, and hence poseinsignificant risks.

All measured indoor air concentrations met the criteria except for three buildings, where certainindoor TCE ah- concentrations were above EPA Region DCs draft provisional goals. Mitigationmeasures are being implemented to reduce the concentrations in these three buildings. In the fallsampling event, certain buildings showed indoor air concentrations slightly higher than EPA RegionDCs provisional value for TCE because these buildings were not ventilated (these buildings wereeither vacant or sampled on the weekend). Once the ventilation system was started again, additionalsamples were collected that showed concentrations within all acceptable criteria.

Certain pathway samples showed concentrations of TCE above EPA Region IX's provisionalvalue only. Although exposure to concentrations hi pathway samples is typically short andlimited, or not feasible (e.g., samples collected in cracks), and although EPA Region IX's draftprovisional values are unpromulgated, are subject to change and are under further evaluation byEPA and other agencies, the MEW Companies implemented voluntary mitigation measures forthese locations. Results of mitigation measures are submitted to EPA by each individualcompany, and the reader is referred to those reports for additional detail.

7.3. Question C: Has any Other Information Come to Light that CouldCall into Question the Protectiveness of the Remedy?

No ecological targets were identified during the endangerment assessment (ICF-Clement, 1988)and none were identified during the five-year review. Therefore monitoring of ecological targetsis not necessary. No weather-related events have affected the protectiveness of the remedy.There is no other information that calls into question the protectiveness of the remedy.

7.4. Summary of Technical Assessment

According to the data reviewed, the remedy is functioning as intended by the ROD. There havebeen no changes in the physical conditions of the site that would affect the protectiveness of theremedy. ARARs for soil contamination specified in the ROD have been met.

Other than EPA Region DCs draft provisional values for TCE that remain under EPA review,there have been no changes in the toxicity factors for the contaminants of concern that were usedin the EA. There have been no changes to the standardized risk assessment methodology thatcould affect the protectiveness of the remedy. There is no other information that calls intoquestion the protectiveness of the remedy.

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8. ISSUES

Issue

Capture zone analyses suggest that capture east ofHangar 1 warrants enhancement

Some indoor air samples collected at MEWCompanies former facilities showed concentrations ofTCE higher than EPA Region DCs draft provisionalvalue

Currently AffectsProtectiveness

(Y/N)

N

N

Affects FutureProtectiveness

(Y/N)

Y

N

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9. RECOMMENDATIONS AND FOLLOW UPACTIONS

Issue

Capture zoneanalyses suggestthat capture east ofHangar 1 warrantsenhancement

•Some indoor airsamples collected atMEW Companiesformer facilitiesshowedconcentrations ofTCE higher thanEPA Region IX'sdraft provisionalvalue

RecommendationAnd Follow up

Action

Install recovery wellsto enhance capture

Indoor airconcentrations arebeing reduced by acombination ofmitigation measuresincluding sealing ofcracks, sealing ofconduits, andenhancement ofventilation.

PartyRespon-

sible

Navy

MEWCompanies

Over-sight

Agency

EPA

EPA

Date

Unknown

Fall 2003&

Whiter2004

AffectsProtectiveness

(Y/N)

Current

N

N

Future

Y

N

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10. PROTECTIVENESS STATEMENT

The remedy is expected to be protective of human health and the environment upon attainmentof groundwater cleanup standards, hi the interim, exposure pathways that could result inunacceptable risks are being controlled, and exposure to, or the ingestion of, groundwater isprevented. Exposure to impacted soils has been addressed by individual MEW Companies byinstalling and operating SVE systems, or excavating soils. These soil remedial activitiesachieved cleanup goals.

Long-term protectiveness of the remedial action will be verified by obtaining additionalgroundwater samples to fully evaluate the progress of remediation. Current data indicate that theconcentrations have decreased significantly, and that the remedy is functioning as required toachieve groundwater cleanup standards.

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11. NEXT RE VIEW

The next five-year review for the MEW Site is required by August 2009, five years after EPAfinalizes its five-year review.

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12. REFERENCES

Canonie Environmental, 1988, Feasibility Study,Middlefield-Ellis-Whisman Area, Mountain View,California, November.

Canonie Environmental, 1991, Unified Quality AssuranceProject Plan, Middlefield-Ellis-Whisman Site,Mountain View, California, December 13.

Canonie Environmental, 1992a, Well Destruction Report,Well 6S2W14N2, EPA 106 Order Joint Work,Potential Conduit Program, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, SobratoDevelopment Companies, General InstrumentCorporation, 2 September.

Canonie Environmental, 1992b, Well Destruction Report,Well 6S2W23E1, EPA 106 Order Joint Work,Potential Conduit Program, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, SobratoDevelopment Companies, General InstrumentCorporation, 9 December.

Canonie Environmental, 1992c, Well Destruction Report,Well 6S2W23D*3, EPA 106 Order Joint Work,Potential Conduit Program, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, SobratoDevelopment Companies, General InstrumentCorporation, 9 December.

Canonie Environmental, 1993a, Well Destruction Report,Well 6S2W14N3, EPA 106 Order Joint Work,Potential Conduit Program, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, SobratoDevelopment Companies, General InstrumentCorporation, 25 May.

Canonie Environmental, 1993b, Well InvestigationReport, Well 6S2W23L*!, EPA 106 Order Joint Work,Potential Conduit Program, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, SobratoDevelopment Companies, General InstrumentCorporation, 25 May.

Canonie Environmental, 1993c, Well InvestigationReport, Well 6S2W34M*!, EPA 106 Order JointWork, Potential Conduit Program, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, SobratoDevelopment Companies, General InstrumentCorporation, 25 May.

Canonie Environmental, 1993d, Well InvestigationReport, Well 6S2W14N*2. EPA 106 Order JointWork, Potential Conduit Program, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, SobratoDevelopment Companies, General InstrumentCorporation, 25 May.

Canonie Environmental, 1993e, Well InvestigationReport, Well 6S2W22H*10, EPA 106 Order JointWork, Potential Conduit Program, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, SobratoDevelopment Companies, General InstrumentCorporation, 28 June.

Canonie Environmental, 1993f, Well InvestigationReport, Well 6S2W14N*!, EPA 106 Order JointWork, Potential Conduit Program, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, SobratoDevelopment Companies, General InstrumentCorporation, 28 June.

Canonie Environmental, 1993g, Well InvestigationReport, Well 6S2W23D*4, EPA 106 Order JointWork, Potential Conduit Program, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, SobratoDevelopment Companies, General InstrumentCorporation, 18 August.

Canonie Environmental, 1993h, Well InvestigationReport, Well 6S2W23E*!, EPA 106 Order JointWork, Potential Conduit Program, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, Sobrato

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Development Companies, General InstrumentCorporation, 18 August.

Canonie Environmental, 1993i, Well InvestigationReport, Well 6S2W23M1, EPA 106 Order Joint Work,Potential Conduit Program, .Middlefield-Ellis-Whisman -Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, SobratoDevelopment Companies, General InstrumentCorporation, 18 August.

Canonie Environmental, 1993J, Well Destruction Report,Well 6S2W23L*3, EPA 106 Order Joint Work,Potential Conduit Program, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Fairchild Semiconductor Corporation, NECElectronics Inc., Siltec Corporation, SobratoDevelopment Companies, General InstrumentCorporation, 23 August.

Canonie Environmental, 1993k, Plume DefinitionProgram, Middlefield-Ellis-Whisman Site, MountainView, California, March.

Geomatrix Consultants, 2003, Air Sampling Report, 425National Avenue, Mountain View, California,prepared for Vishay General Semiconductor, Inc. andSUMCO Oregon Corporation, August.

Geosyntec Consultants, Inc., 2003a, Revised Work Planfor Indoor and Outdoor Air Sampling, 501 Ellis Street,Mountain View, California, prepared for NECElectronics America, Inc., April.

Geosyntec Consultants, Inc, 2003b, Results of Indoor andOutdoor Air Sampling, 501 Ellis Street, MountainView, California, prepared for NEC ElectronicsAmerica, Inc., July.

Groundwater Technology, 1996, Operation andMaintenance Plan for the Soil Vapor Extraction andTreatment System, 350 Ellis Street, Mountain View,CA, prepared for Raytheon Company, March.

Harding Lawson Associates, 1988, RemedialInvestigation Report, Remedial Investigation/Feasibility Study, Middlefield-Ellis-Whisman Area,Mountain View, California, prepared for FairchildSemiconductor Corporation, Intel Corporation, andRaytheon Company, June.

Harding Lawson Associates, 1999, Human Health RiskAssessment, 350 Ellis Street, Mountain View,California, prepared for Veritas Software Corporation,September.

ICF-Clement, 1988, Endangerment Assessment for theMiddlefield-Ellis-Whisman site in Mountain View,

California, prepared for Camp Dresser & MacKee,January.

Locus Technologies, 1997, Health Risk Assessment, 313Fairchild Drive, Mountain View, California, preparedfor Keenan-Lovewell Ventures and FairchildSemiconductor Corporation, 27 August.

Locus Technologies, 1998, DW3-219 Pumping Test,Regional Groundwater Remediation Program,Middlefield-Ellis-Whisman Site, Mountain View,California, prepared for Raytheon Company andIntel Corporation, 18 December.

Locus Technologies, 1999, Final Operation &Maintenance Plan, Regional Ground WaterRemediation Program, South of U.S. Highway 101,Mountain View, California, prepared for RaytheonCompany and Intel Corporation, October.

Locus Technologies, 2000a, Operation & MaintenancePlan, Regional Ground Water RemediationProgram, North of U.S. Highway 101, MountainView, California, prepared for Raytheon Companyand Intel Corporation, May.

Locus Technologies, 2000b, Two-Year Evaluation,Regional Groundwater Remediation Program, Southof U.S. Highway 101, Middlefield-Ellis-WhismanSite, Mountain View, California, prepared for IntelCorporation and Raytheon Corporation, 10 July.

Locus Technologies, 2001, Two-Year Evaluation,Regional Groundwater Remediation Program,North of U.S. Highway 101, Middlefield-Ellis-Whisman Site, Mountain View, California, preparedfor Intel Corporation and Raytheon Corporation, 27April.

Locus Technologies, 2002, Work Plan for Air Sampling,Middlefield-Ellis-Whisman Site, Mountain View,California, December.

Locus Technologies, 2003a, Revised Work Plan for AirSampling, Middlefield-Ellis-Whisman Site, MountainView, California, April.

Locus Technologies, 2003b, Results of Air Sampling,Former Fairchild Semiconductor CorporationFacilities, Middlefield-Ellis-Whisman Site, MountainView, CA, August.

Locus Technologies, 2003c, Results of Air Sampling,Raytheon Company Former Facilities, Middlefield-Ellis-Whisman Site, Mountain View, CA, August.

PES Environmental, Inc., 2003, May 2003 Air SampleResults, Former Siemens/Sobrato Properties, 455 and487 East Middlefield Road, Mountain View,California, August.

C VDOCUMENTS AND SETTINGS\OWNER\M Y DOCUMENTS\EL1E\FIVE YEARS\5Y MAIN TEXT - REGlONAL.DOC(17-Dec-03)

Report: Regional Groundwater Remediation Program Five-Year EvaluationMiddlefteld-Ellis-Whisman SiteMountain View, California

Locus

Smith Technology Corporation, 1996a, Revised FinalDesign, Regional Groundwater RemediationProgram, South of U.S. Highway 101, Middlefield-Ellis-Whisman Site, Mountain View, California,prepared for Intel CorporatioA and RaytheonCompany; 8 January.

Smith Technology Corporation, 1996b, Revised FinalDesign, Regional Groundwater RemediationProgram, North of U.S. Highway 101, Middlefield-Ellis-Whisman Site, Mountain View, California,prepared for Intel Corporation and RaytheonCompany, 17 June.

Smith Technology Corporation, 1997, Health RiskAssessment, 369 and 441 North Whisman Road and464 Ellis Street, Mountain View, California, preparedfor 464 Ellis Street Associates, L.P. and SchlumbergerTechnology Corporation, 13 March.

U.S. Department of the Navy, 2003, Final West-SideAquifers Treatment System Optimization Work Plan,

Revision 0, Moffett Federal Airfield, Moffett Field,California, July

U.S. Environmental Protection Agency, 1989, Record ofDecision, prepared for Fairchild, Intel, and RaytheonSites, Middlefield-Ellis-Whisman Site, MountainView, California, May.

U.S. Environmental Protection Agency, 2001,Comprehensive Five-Year Review Guidance, Officeof Emergency and Remedial Response, EPA 540-R-01-007, June.

Weiss Associates, 2003a, May 2003 Air SamplingReport for Former Intel Mountain View Facility,355/365 East Middlefield Road, Mountain View,California, August.

Weiss Associates, 2003b, Letter to Ms. Alana Lee ofEPA entitled "MEWRGRP Groundwater ElevationsTechnical Rationale for Proposed MeasurementFrequency Reduction", 20 November.

C IDOCUMENTS AND SETTINGS\OWNER\MY DOCUMENTSVELIEVHVE YEARS\5Y MAIN TEXT - REGIONAL DOC(17-Dec-03)

Report' Regional Groundwater Remediation Program Five-Year EvaluationMiddlefield-Ellis-Whisman SiteMountain View, California

Locus

TABLES

&LE 1-1CHECK LIST FOR EPA's REQUEST FOR INFORMATION - FIVE YEAR REPORT

REGIONAL GROUNDWATER REMEDIATION PROGRAMMIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VIEW, CALIFORNIA

GENERAL REQUESTS

Request1. Site Vicinity Map - Format: PDF

2. MEW Regional Site Map with All Facilities - former building locations and addresses -Format: PDF

3. MEW Regional Site Map with All Facilities - current building locations and addresses -Format: PDF4. MEW Regional Site Map with current treatment system locations - Format: PDF5. MEW Regional Site Map with Areas of Soil Cleanup - Format: PDF6. Site Location Maps - By facility - Format: PDF7. Brief Site Description and Background

8. Description of remedial actions for groundwater [and soil, if applicable], including all components of theremedy, and current status of each of the components. Include descriptions of old and new treatmentfacilities, specify changes, reason for change, and year implemented.

9. Tables and text summarizing that remedial actions achieved the ROD objectives (including soilexcavation and SVE remedies). Format: Excel and Word or WordPerfect.

10. Table and text summarizing compliance with ROD requirements to seal potential conduits, agriculturalwells and any other abandoned wells. Also, provide a figure with location(s) of abandoned wells, ifpossible. Format: Excel, Word or WordPerfect and PDF.

11. Table summarizing chronology of site events and milestone dates for implementation of the responseactions. Format: Word or WordPerfect.

12. Text summarizing treatability studies, results, and conclusions/recommendations, if applicable. Format:Word or WordPerfect.

LocationReport: Figure 1-1

Report: Figure 3-1

Report: Figures 1-2 and 1-3Report: Figures 4-1 and 4-2Report: Figure 4-3Report: Figures 1-2 and 1-3Report: Chapter 3

Report: Section 3.4 andChapter 4.0

Report: See table in Section7.1CD ROM: RODobjectives.xlsReport: Section 4.1.3, Table4-1, and Figure 4-4

Report: Chapter 2

NA

CommentsSubmitted on 8-Dec-03

Submitted on 8-Dec-03

Submitted on 8-Dec-03Submitted on 8-Dec-03Submitted on 8-Dec-03

"Submitted on 8-Dec-03Also see Word version ofthe report.Also see Word version ofthe report.

Submitted on 8-Dec-03Also see Word version ofthe report.Also see Word version ofthe report.None performed by theRGRP

TABLE 1-1CHECK LIST FOR EPA's REQUEST FOR INFORMATION - FIVE YEAR REPORT


GROUNDWATER WELLS

Request1 . Table summarizing all wells installed post Remedial Investigation (1987) for purposes of remedy

implementation. Please include well identifier, units screened, year constructed and purpose. Format:Excel.

2. Separate tables summarizing new and abandoned wells. These tables should specify year of constructionor abandonment and aquifer screened. Also, provide a figure with abandoned well locations. If it wasnecessary to replace monitoring wells for building construction, please provide Format: Excel and PDF.

3. Base maps of all wells on facility and nearby properties

LocationReport: Table 3-2

Report: Table 3-3 andFigures 4- 11 to 4-16

Report: Figures 4-5 to 4-10




CHEMICAL DATA

Request1 . Tables summarizing all MEW chemicals of concern for all wells since inception of groundwater

sampling;. Format: Excel or Access.2. TCE concentration contour figures from 1988 to January 2003, and other VOCs, if available. Format:PDF and Hard CODV

LocationReport: Appendix B

Report: Appendix E



GROUNDWATER ELEVATIONS, CAPTURE ZONES, GRADIENTS

Request1. Tables summarizing groundwater level elevation data for each well since inception of data collection

through September 2003. Format: Excel Table or Access Database.2. Groundwater hydrographs (groundwater elevation versus time) and any available graphs of TCE

concentration versus time. Format: Excel or PDF.3. Piezometric surface maps for all aquifers: quarterly postings maps (or contour maps) and semi-annual

contour maps from 1988 through September 2003. Format: PDF and Hard Copies4. Capture Zones Maps for all aquifers (from start of pumping through September 2003). Format: PDF

5. Since aquifer test results are often embedded in other documents, please provide a table summarizingaquifer test results and a list of documents where these results can be found. Format: Excel and Word orWordPerfect.

6. Tables summarizing vertical hydraulic gradient data from before remediation began through September2003. This information should be provided by aquifer and well pair. Format: Excel.

7. Tables summarizing horizontal gradients since inception of the groundwater monitoring network(Raytheon and Fairchild/Schlumberger) across slurry wells (through September 2003).Format: Excel

LocationReport: Appendix A

Report: Appendix A

Report: Appendix C

Report: Appendix C

Report: Table 3-1

Report: Appendix D

NA







No slurry walls have beeninstalled as part of the RGRP.



SYSTEMS OPERATIONS, PERFORMANCE AND O&M

Request1. Base map of locations of all extraction wells and piping to treatment systems

2. Briefly describe operating procedures and any issues or problems

3. Table summarizing operation of treatment systems including down-times since inception of groundwaterextraction and treatment through September 2003. Format: Excel.

4. Description of system operations/O&M requirements, estimated costs, and reasons for unanticipated orunusually high O&M costs [table of annual O&M costs, optional]

5. Table summarizing estimates of TCE and VOC mass in groundwater from before groundwaterextraction began to September 2003. Format Excel.

6. Table summarizing mass removal (TCE and VOCs) by month from inception of groundwater extractionto September 2003. These tables should include monthly groundwater extraction rates and volumes.Format: Excel.

7. Graph of cumulative mass removal graphs for TCE and VOCs with mass removal by year (or month)Format: Excel.

8. Discussion (and figures as needed) demonstrating progress made in removing TCE and VOCs from theaquifer. Format: Word or WordPerfect text and graphs in Excel.

9. Table summarizing treatment plant operation including influent and effluent flow rates and contaminantconcentrations from the inception of treatment to September 2003. Format: Excel or WordPerfect.

10. Table(s) summarizing extraction well performance including pumping rates (designed and actual) andwell rehabilitation (all years through September 2003). Note any exceedances, duration, and correctiveactions. Format: Excel, Word or WordPerfect.

11. Table summarizing BAAQMD permit and air emissions compliance (through September 2003). Format:Excel, Word or WordPerfect.

12. Table summarizing NPDES permit compliance (through September 2003). Note any exceedances,duration, and corrective actions. Format: Excel, Word or WordPerfect.

13. List of interview candidates with phone numbers with knowledge of groundwater extraction networkand/or groundwater treatment plant operation. Format: Excel or WordPerfect.

LocationReport: Figures 4- 1 and4-2Report: Section 4.2

Report: Table 4-5CD ROM: Table 4-5 TSOperation.xlsReport: Section 4.2

Report: Section 6.3.5 andAppendix F

Report: Table 6-2

Report: Section 6.3.5

Report: Sections 6.3.4 &6.3.5Report: Table 6-2

Report: Table 4-2

Report: Table 4-3CD ROM: Table 4-3&4-4Compliance.xlsReport: Table 4-4CD ROM: Table 4-3&4-4Compliance.xlsReport: Section 6.3.7


Also see Word version of thereport.

-

Also see Word version of thereport.Submitted on 8-Dec-03Also see Word version of thereport.Submitted on 8-Dec-03


Also see Word version of thereport.Submitted on 8-Dec-03




REGIONAL GROUNDWATER REMEDIATION PROGRAMMroDLEFBELD-ELLIS-WHISMANSlTE, MOUNTAIN VIEW, CALIFORNIA

OTHER REQUESTS

RequestOpportunities for Optimization: Briefly summarize recommendations for remedy optimization, whetheropportunities exist to improve the performance and/or reduce the costs of monitoring, sampling, andtreatment systems operations.Indicators of Potential Issues: Discuss any issues or problems, actions taken, and/or any recommendationsfor improvement or follow-up actions.

Successes/Problems/Lessons Learned - Optional

a Achievements, Progress, Effectiveness, Improvementsa Implementation of access and institutional controlsa Construction of the Remedya System Operationsa Unusual situations or problems at the site.

Reference Documents: Please list reference documents - Format: Word or WordPerfect

LocationReport: Chapter 7

Report: Chapters 7, 8 and9

Report: Chapters 6 and 7

Report: Chapter 12

CommentsAlso see Word version of thereport.

Also sec Word version of thereport.



ITABLE 3-1

AQUIFER TEST RESULTSMIDDLEFIELD-ELLIS-WHISMAN SITE


Aquifer

A-AAAAAAAAAAAAAAAABlBlBlBlBlBlBlBlBlBlBlBlBlBlBlB2B2B2B2B3B3B3C

Pumped Well

69A73A82A83A89A95AEX-4

GSF-1AME-1A

NEC12ANEC22AE

RE1ARE2ARW1ARW9A

W09-35(A1)W09-38(A1)

3B147B178B185B1

GSF-1B1PW-4R2B1R4B1R5B1R9B1

RW1B1W09-09(A2)W09-20(A2)W09-22(A2)W09-41(A2)

17B2RW1B2GSF-1B2RW9B2

29B358B3

R11B3DW3-219

Observation Wells

69A, 39A, 41A, 42A, 44A73A, 86A

85A3 wells, 87A

120A113AEX-4

GSF-1AME-1A

NEC12ANEC22AE

RE1A, RP1, R2ARE2A

4 wells, 17A, 18ARW9A, 76A, 62A, 66A

W09-35(A1)W09-38(A1)

3 wells, 3B1, RW9B1, 60B1, 13B147B1, 73B1

111B1106B1

GSF-1B1E-24R2B1

R4B1, R5B1R5B1, R3B1

R9B119B1.35B1, 1B1

W09-09(A2)W09-20(A2)W09-22(A2)W09-41(A2)17B2, 71B2

2 wells, 40B2, 9B2GSF-1B2

RW-9B2, 24B2, 61B22 wells, 72B358B3, 70B3

R11B3,ME1C(B3)DW3-210, 11C,R1C

Average Transmissivityfepd/ft)

625436

184932700815733324337180.84488694048215

131349651701

29217406832323115215841238119

41142909540616490155401300

195501844126053938202819013

38717153834861

12612

IA23-007 FairchiliMY - RcgionahEPA - Fin«I\EPA Submmal 8D«03\EPA - Table 3-1 TnnMmMiPElBls<02-Dec-<]3)

TABLE 3-1AQUIFER TEST RESULTS

MIDDLEFIELD-ELLIS-WHISMAN SITEMOUNTAIN VIEW, CALIFORNIA

Notes:The data above has been compiled from tiie following reports:

Harding Lawson Associates, 1987, Remedial Investigation Report, Remedial Investigation/Feasibility Study,Middlefield-Ellis-Whisman Area, Mountain View, California, prepared for Fairchild Semiconductor Corporation,Intel Corporation, and Raytheon Company, June.

Locus Technologies, 1998, DW3-219 Pumping Test, Regional Groundwater Remediation Program, Middlefield-Ellis-Whisman Site, Mountain View, California, prepared for Raytheon Company and Intel Corporation, 18 December.

Locus Technologies, 2000, Two-Year Evaluation, Regional Groundwater Remediaiton Program South of U.S.Highway 101,, Middlefield-Ellis-Whisman Site, Mountain View, California, July

I:\23-007 FaircbikWY - Regional\EPA - FiiaJ\EPA Submitul 8Dtc03\EPA - Tabte 3-1 TransmissiP«i«li<t02-D«:-l)3)

TABLE 3-2MONITORING WELL DETAILS


Well ID

109 A142 A144 A14D02A14D09A14D14A153A15H05A162 A19A Sealed1A20A21A22A26A29A42A45A54A62A65A72A73A74A75A77A78A79A81A82A88A89A92A93A

Purpose

MonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoriftgMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoring

CasingDiam

444

2

4

42222222222244444444444444

Top ofScreen

122223

567

13

818201514141215101314101920151518232213131520181818

Bottom ofScreen

27273825151723

2833403030303030352540302925252528283223233030283328

TotalDepth

28294025

16.51835

31.53133403030303030352540302927272730303424253332303530

North

332011.6330614.2330882.2337654.9337220.6337332.1331453.5336203.4332598.2331108.7

330720.75330590.8331496.8331475.9331074.3

331440331987.8331695.3332448.7333072.3334390.6333302.2335167.9334261.9334276.7331410.5332322.9333420.2335064.4334692.7335939.9336368.5338676.4338028.9

East

15489611547776.21546981.61548302.81547603.21547505.31549271.41546932.61549958.61548166.11547453.51549496.11547672.1

15479381549149.31549312.71548769.91549198.31548745.31548785.51548698.41549559.51549509.91549504.71547732.41547192.21547384.51547824.61548889.31548316.71547056.91547731.91547671.31549378.4

Aquifer

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

Constructionyear

1986198619871990199019921991199020001982198219821982198219821982198219821982198219821985198519851985198519851985198519851986198619861986

IM5-QQ1 FamtHtoiY • Rt£\onal\EP A - FinaWSPA Subtotal 8Dec03\EPA - Table 3-2 MW Details.*!* (07-Dec-03) Page 1 of 7



Well ID

95A99AREG-10AREG-11AREG-12AREG-IAREG-2AREG-3AREG-4AREG-5AREG-6AREG-7AREG-8AREG-9AREG-MW-1AREG-MW-2ARW-9AW12-6W14-3W60-2W89-1W89-2W89-3W89-5W89-7W89-8W89-9W9-16W9-38WT14-1WU4-1WU4-16WU4-18WU4-3

Purpose

MonitoringMonitoringExtractionExtractionExtractionExtractionExtractionExtractionExtractionExtractionExtractionExtractionExtractionExtractionMonitoringMonitoringExtractionMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoring

CasingDiam

446666666666666664

4444444

2

Top ofScreen

189.515291222101316142412211720

18.5132015

17.51715151517

14.51913

7.8

Bottom ofScreen

2824.5

40492742252831292927312735

28.5232530

27.52725252527

24.52923

17.8

TotalDepth

30294250304527

30.534

30.531

28.534

28.537

29.5253035

30302525252725

18

North

338761.2331548.3

332737.3146332904.7197

332559.895332644.9569

333585.14334691.72334855.62334152.69336974.03336304.05334447.2

335161.38332232.204

332676.93333064.6338209.5333561.9333754.6333774.2334084.5334374.1334958.5

335574335667.4336067.4335175.4335113.1

334679333460.6336951.2337898.2334846.5

East

1548336.41548393.2

1549419.2351549068.639

1548887.091549513.111548731.541548890.341548461.661548585.611548056.761547748.561547785.641547478.58

1548826.7041548672.251548700.4

15487951549911154942415481511547896154715615473691546462154753315474381548196154844015499051548778154758615484281548533

Aquifer1

AAAAAAAAAAAAAAAAAAlAlAlAlAlAlAlAlAlAlAlAlAlAlAlAlAl

Constructionyear

1986198619971997199719971998199819981998199819981998199819971997198519911988199219911991199119911991199119911990199019901992199219921992

ainhild\5Y - RcgionaREPA • FmaI\EPA Submittal 8Dec03\EPA - Table 3-2 MW D«ails.xk (07-Dcc-03) Iof7



Well ID

W14-5W89-11W89-12W89-13W89-14W9-17W9-25W9-41WNB-14WU4-12WU4-13WU4-19WU4-2WU4-4WU4-5WU4-6WU4-7103B1105B1112B1119B1122B1124B112B1139B113B11408 1143B114B126B132B133B146B147B1

Purpose

MonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoring

CasingDiam

4444

4

44444444444444444

Top ofScreen

44.95254505033

29.53424

7060625264576555626560515864563857

Bottom ofScreen

49.96264606038

39.54429

8070676269627070678570616374704862

TotalDepth

58.763656061

61

82726964716472706986

71.5646576705064

North

333567.8333766.4334079.6334381.5334955.7335366.9336561.1

335127337297.8335552.1336051.3337623.6333505.2

334848333568.7334366.1

334665331640

332042.6331444.3332013.7330877.9332401.3333425.6337881.6332888.8332062.3332388.2332686.3331412.8332582.2332321.1335071.4335173.7

East

154990115481481547889154715115473751548750154800915484351547762154785115475291548029154882115485271548414154869915489701546453

1549075.71549178.1

15483861546998.21547112.61547825.71548215.11549071.21547064.31548868.71549529.31547185.21548841.61547388.9

15488841549495.6

Aquifer

A2A2A2A2A2A2A2A2A2A2A2A2A2A2A2A2A2BlBlBlBlBlBlBlBlBlBlBlBlBlBlBlBlBl

Constructionyear

1988199119911991199119901990199019921992199219921992199219921992199219861986198719861987198719851988198519881988198519851985198519851985

1U3-OQ1 FMichiWSY • RepotwlVEP A - FmaflEP A Submmal 8Dcc03\EP A - Table 3-2 MW Details xls (07-Dec-03) Page 3 of 7



Well ID

48B149B150B156B168B174B177B178B179B181B183B187B18B191B192B198B1ME1B1ME2B1NEC14B1NEC18B1NEC8B1REG-lOB(l)REG-llB(l)REG-lB(l)REG-2B(1)REG-3B(1)REG-4B(1)REG-5B(1)REG-6B(1)REG-7B(1)REG-8B(1)REG-9B(1)REG-MW-lB(l)REG-MW-2B(1)

Purpose

MonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringExtractionExtractionExtractionExtractionExtractionExtractionExtractionExtractionExtractionExtractionExtractionMonitoringMonitoring

CasingDiam

4444444444444444444426666666666666

Top ofScreen

48647256465653394238464568485557696459633832585939575837494834325357

Bottom ofScreen

53688259516658495248565578586566747469675852687464726847595854427367

TotalDepth

557183605268

60.5515450585778606868797971

70.558

53.5697666757150

60.5605644

74.569

North

334255.2334248.6334689.8332898.2334281.3330580.7332408.2335935.1336367.2337152.2338022.4

335379332179.5331554.2331541.5330876.6330028.4333655.2331162.6329800.5331672.2

335978.18332881.877

332569.9695332686.921333424.238

331371.9855333538.27334867.55334717.32335683.52337154.51

332235.169332274.88

East

1549508.41549975

1548325.61547004.11547723.2

15494931548789.51547055.2

15477271549710.41549379.81546368.41549405.41548394.51548937.9

15480531548855.71547012.41549391.5

15493551549611.3

1547055.251549059.5341548846.5171549471.5081547780.1711549269.772

1548518.891548465.731549021.791548024.961548496.47

1548818.5911548699.007

Aquifer*

BlBlBlBlBlBlBlBlBlBlBlBlBlBlBlBlBl

I?1

BlBlBlBlBlBlBlBlBlBlBlBlBlBlBlBl

Constructionyear

1985198519851985198519861986198619861986198619861982198619861986198519851989198919841998199719971997199619971998199819981998199819971997

) airclv!d\5Y • RcgionatNEPA - Finat\EPA Submntal 8Dec03\EPA - Table 3-2 MW Details xls (07-Dec-03)



Well ID

RW-l(Bl)RW-13B(1)RW-2(B1)RW-9(B1)R10B2113B2123B2125B2129B2132B2134B215B216B217B236B237B238B243B251B254B262B26B275B276B282B289B2NEC18B2NEC8B2REG-1B(2)REG-3B(2)REG-MW-1B(2)RW-5(B2)RW-7(B2)RW-9(B2)

Purpose

MonitoringExtractionExtractionExtractionMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringExtractionMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringExtractionExtractionMonitoringMonitoringMonitoringExtraction

CasingDiam

2626244444444444444444444444666666

Top ofScreen

5272465985698494957983907987868878

85.5927980718290718090

98.28275798480

82.6

Bottom ofScreen

7282566990849499

1108988

1008492919588919784909187

100869095

1039285899490

92.6

TotalDepth

738459

71.5958696

1011129190

1018794

92.59590

93.59986919189

1028892

97.5107

938890

97.69395

North

331262.1331795.7515

331573.8333082

332145.1332763.7336653.4332402.5330603.7331245.9331142.3329654.9331070.6334364.3332586.7

331415332324.548

333475.3335075.8

334247332880.2330837.4331285.7331636.8338681.8331559.2329804.6331665.3

332573.6119332651.3175

332237.875332864.9333089.2

333066

East

1547668.31546479.687

1547744.21548705

1547882.41548652.21548488.21547106.91547810.21548600.61548942.21547110.51549167.51548655.81548824.91547177.3

1547379.8791547827.21548890.41549997.71549068.31547464.61549802.11546459.11547669.41548395.91549340.51549622.3

1548837.8321549507.3081548810.348

1548166.31548569.81548702.3

Aquifer"

BlBlBlBlB2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2B2

Constructionyear

1985199519861986198519861987198719871987198719851985198519851985198519851985198519851982198619861986198619891985199719971997198519861985

V\23-«V) VamMKY - Rt-B'mnal\EPA - FinaNtPA Submittal SDecOMPA - Table 3-2 MW Details xls (07-Dec-03) Page 5 of 7



Well ID

128B3I33B3142B3 Sealed27B3 Sealed28B329B330B331B339B34 1B3 Sealed44B355B357B358B3 Sealed59B3 Sealed63B365B366B3 Sealed70B3 Sealed72B3 SealedIOC11C14(C)1C Sealed2C3C4C5C Sealed6C7C Sealed8C9CDW1-230DW2-234

Purpose

MonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringExtractionMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoring

CasingDiam

4444444444444644444444

4

4444444

Top ofScreen

117127140123122124120

135.5136139129123116128126121111135130117201209

192

182174.5

193193

189.8194200

Bottom ofScreen

127132145128132134130

145.5143142144133126135131128131145135127216214

202

207210218213

214.8229230

TotalDepth

129134146130134136132146145

143.5147134129137136131133146137129218216

205

209220220219218230234

North

330900.9331220.9332064.2329666.7

331066334374.2330834.2332495.5333070.5331405.2332575.5334694.9335177.2334267.3334235.9332899.1331527.2332894.7334272.3334388.7

330880331227.3

336974330853.4334712.8334863.5334343.1334286.8332578.4332909.4331633.4

331034330586.4

331164

East

1546939.11548679

1547058.61547114.61549183.51548657.61547453.91548009.21548691.31547183.31548830.31548306.9

15495061549514.11549987.31549074.51548759.51547014.21549522.51548653.31546991.11548658.4

15496281547469.41548439.91548889.31549424.41547712.91548822.51546992.11546468.51546744.81546744.51545835.4

Aquifer

B3B3B3B3B3B3B3B3B3B3B3B3B3B3B3B3B3B3B3B3CCCCCCCCCCCCCC

Constructionyear

198719871988198519851985

r 1985198519851985198519851985198519851985198519851986198619871987

1984

1985198519851986[1986]19861986J

Iairchil J\5Y - RcgionalXEPA - FmaI\EPA Submma! 8Dec03\EPA - Table 3-2 MW Details xls (07-Dec-03)



Well ID

DW3-219DW4-2 17 SealedDW6-205ME-3C SealedRW-1CDW3-244DW3-334DW3-364DW3-505 SealedDW3-505RDW3-551DW4-270 SealedDW6-231DW6-304DW6-470DW6-496DW7-302 SealedDW7-405 Sealed

Purpose

ExtractionMonitoringMonitoringMonitoringMonitoringExtractionExtractionExtractionMonitoringExtractionMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoringMonitoring

CasingDiam

444464444644444466

Top ofScreen

185185190188205230315350490490544241226294465486287380

Bottom ofScreen

215215205208215240330360500500549266231304470496302405

TotalDepth

219217

205.5210218244334364505503

551.5270236307471497305408

North

331546.4331391.9331945.1334366.9

331939.2202331566.9331552.8331558.8331562.3

331561.4184331565.5331384.3331944.9331945.5331945.9

331945331780.867

331780.5407

East

1548678.81547641.11549335.81548645.2

1546542.4391548651.81548658.51548682.2

15486701548665.607

1548625.51547638.41549336.31549336.51549335.61549335.4

1546495.4831546480.346

Aquifer

CCCCCDEEPDEEPDEEPDEEPDEEPDEEPDEEPDEEPDEEPDEEPDEEPDEEPDEEP

Constructionyear

198619861987198519951986198619861986199719881986198719871987198719951995

t;\Z3-<N7 • RcjtonilNEPA • Fmal\EPA. Submittal 8Dcc03\EPA - Table 3-2 MW Details.xls (07-Dec-03) Page 7 of7

TABLE 3-3LIST OF SEALED MONITORING WELLS


Well ID100B1 Sealed102A Sealed103A Sealed104A Sealed10A Sealed11 1A Sealed112A Sealed114A Sealed117A Sealed1 1 A Sealed1 21 B2 Sealed126B1 Sealed127B2 Sealed131 A Sealed1 31 B2 Sealed132A Sealed135A Sealed135B1 Sealed136B2 Sealed137B1 Sealed13A Sealed142B3 Sealed14A Sealed150A Sealed18A Sealed18B2 Sealed19A Sealed19B1 Sealed1B1 Sealed1C Sealed25A Sealed27A Sealed27B3 Sealed2A Sealed30A Sealed34A Sealed34B2 Sealed35B1 Sealed3A Sealed3A Sealed41 B3 Sealed47A Sealed48A Sealed49A Sealed52A Sealed52B2 Sealed53A Sealed55A Sealed58B3 Sealed

CasingDiameter

4444244442444444444424242424442242214422422224126

Top ofScreen4924182023222515131981458017801722558056151401814.5159418677219215141232215

82672020139141515

93

128

Bottom ofScreen5434282535374025283986509027902732709076401453834.5409933728520230321283530

85723737142343530

98

135

TotalDepth563630273539.5

2629398851922992293474967840146403540101337385205303213035302086.5733737

143.5343530

100

137

YearAbandoned

199619961996199619861996199619961996198919961996199620011996200119971996199619961997199619961997198619962001198619871996199619961996198619861986199619961996199619961986198619961987199619861987

L 1996

ReplacementWell

175A

174A

160A

158A

I:\23-007 Fairchi!d\5Y - RegionaI\EPA - Fmal\EPA Subtmttal 8Dec03\EPA - Table 3-3 Sealed MVP»ifaHttT-Dec-03)

TABLE 3-3LIST OF SEALED MONITORING WELLSMIDDLEFIELD-ELLIS-WHISMAN SITE


Well ID

59B3 Sealed5A Sealed5B1 Sealed5C Sealed60A Sealed66B3 Sealed7A Sealed7C Sealed87A Sealed8A Sealed96B1 Sealed98A SealedAE/RW-13-1 SealedAE/RW-19-1 SealedAE/RW-1 9-2 SealedAE/RW-9-3 SealedAE/RW-9-4 SealedDW3-505 SealedDW4-21 7 SealedDW4-270 SealedDW5-209 SealedDW5-310 SealedDW5-41 1 SealedDW5-479 SealedDW7-302 SealedDW7-405 SealedIE16D SealedIM14B(1)/A SealedIM15A SealedIM16B(2) SealedIM17A SEALEDME-1B3 SealedME-2C SealedME-3C SealedR11 A SealedR11B3 SealedR13A SealedR13B3 SealedR14B2 SealedRUBS SealedR16A SealedR17A SealedR18B2 SealedR1 A SealedR1C SEALEDR21B2 SealedR26A SealedR26B2 SealedR29B2 Sealed

CasingDiameter

42 .442424424466666444555566

424244424

444

24244

44

Top ofScreen

12615

54.518215135231931520381388888

490185241179

298.5393450287380

462610226.515919518811

155

125106130

18801519386.5

88.5113.5

Bottom ofScreen

13135

64.52073514535218333553282929293635500215266208309410478302405

563611736.517922020831180

138116

159.5

28.5952521890

93.5116.5

TotalDepth

13635

64.52093514635

220353555303030303736

505217270210313413480305408

58.53912038.5183.5228.521035181

138117160

28.596

46.5220101

94.5117.5

YearAbandoned

1996199619861996199719961996199719951997200119961997199719971998199819871996199619961996199619961996199619971997199719972001199619961996199719961987199619961996200219971997199720021996198719971997

ReplacementWell

161A

156B1

RH-01A

R67A

I\23-007 FaircluldOT - RegmnaHEPA - FmahEPA Submilta! 8Dec03\EPA - Table 3-3 Scaled MWngW»T-Cec-03)

TABLE 3-3LIST OF SEALED MONITORING WELLS


Well IDR2B1 SEALEDR2B3 SealedR30A SealedR31B2 SealedR32B2 SealedR34A SealedR35A SealedR35B2 SealedR37A SealedR38A SealedR38B3 SealedR39A SealedR3A SealedR40A SealedR42A SealedR43B2 SealedR44B2 SealedR47A SealedR47B2 SealedR48B3 SealedR49A SealedR49B2 SealedR4A SealedR4B1 SealedR56A SealedR5A SealedR61A SealedR66A SealedR7A SealedR8A SealedR8B1 SealedR9B1 SEALEDRE13A SEALEDRE14A SEALEDRE1 A SEALEDRE20A SEALEDRE2A SEALEDRE2B1 SEALEDRE3A SEALEDRE4A SEALEDRE6A SEALEDRP17A SealedRP17B SealedRP18B SEALEDRP1A SealedRP2 SealedRP20B SEALEDRP25A SealedRP25B Sealed

CasingDiameter

(

4

444

4

2

444

4444

4

224

6

6

6

66

44

4

4

Top ofScreen

8

1923

108.5

130

15

21.68589.5

119140.521.587

11.524

202052

18.5

18

53.5

2023

44.547

47

45.5

Bottom ofScreen

28

3943

115.5

137

25

27.289.596

12514726.5100.5

30.534

353572

33.5

38

76.5

3443

5253

51.5

49.5

TotalDepth

30

3943116

139.5

41.5

2990.596.5

126147.527101

3135

41.546.573

34

38.4

78

3546

6765

53.5

74.5

YearAbandoned

2002199220021987198719941997199720001987198720021997-

1997199719972001199719971997199720002000199719871997-

199719971994199120022000198520021985200219852002200219971997200219971985200219971997

ReplacementWellR68B1

R71AR60A

R73A

R70A

R72A

R69B1R69ARE24ARE9ARE25ARE10AR70B1RE4A

RE23A

RP42B

RP43B

I:\23-007 FairchilcM Y - Regk>nal\EPA - FinaMEPA Submitlal 8Dec03\EPA - Table 3-3 Sealed MWltiaBT4>«:-03)

TABLE 3-3LIST OF SEALED MONITORING WELLSMIDDLEFIELD-ELLIS-WHISMAN SITE


Well ID

RP2B SEALEDRP3 SealedRP38A SealedRP39A SEALEDRP3A SealedRP40A SEALEDRP4B SEALEDRW-1 OA SealedRW-1 3A SealedRW-14A SealedRW-1 5A SealedRW-1 7A SealedRW-1 9A SealedRW-22A Sealed

CasingDiameter

22 .46

426862666

Top ofScreen

419.517.515

17.53818

29.51820151228

Bottom ofScreen

4419.520.525

28.14038

39.52835252233

TotalDepth

44.520.520.525.5

295040

40.52936262334

YearAbandoned

20021994198720021997200220021998199619962001199919971997

ReplacementWell

RP41B

RW-29ARW-28ARW-27A

Note:Monitoring wells were sealed because they were not needed after the remedialinvestigation phase, or because of property development when the well interferedwith development plans.

I \23-007 FairchildOT - RegionalVEPA - FmaI\EPA Submitlal 8Dec03\EPA - Table 3-3 Sealed MWtgM»T-Dec-03)

TABLE 4-1ACTIONS TAKEN TO ADDRESS POTENTIAL CONDUITS


PotentialConduit

6S2W14M*!

6S2W14M1

6S2W14M2

6S2W14N*!

6S2W14N*2

6S2W14N1

6S2W14N2

6S2W14N3

6S2W14N4

6S2W22A3

6S2W22A5

6S2W22H*10

6S2W23C*!

6S2W23C*2

6S2W23C1

6S2W23C2

Status

Abandoned and filled with concrete.

Located and sealed.

Located and sealed.

Located under a garage. Believed to be less than 50 feet deep. No further actiontaken.

Located and sealed.

Located and sealed.

Located and sealed.

Located and sealed.

Located and sealed.

Located and sealed.

Located and sealed.

Reclassified as nonexistent.

Located and sealed.

Located and sealed.

Located and sealed.

Located and sealed.

I \23-007 Fairchild\5Y - Regional\EPA - Table 4-1 Polenlial conduits xls (29-Nov-03) Page 1 of 2

TABLE 4-1ACTIONS TAKEN TO ADDRESS POTENTIAL CONDUITS

MTDDLEFffiLD-ELLIS-WHISMAN SITEMOUNTAIN VIEW, CALIFORNIA

PotentialConduit

6S2W23D*!

6S2W23D*2

6S2W23D*3

6S2W23D*4

6S2W23D1

6S2W23D2

6S2W23D3

6S2W23E*!

6S2W23E1

6S2W23E2

6S2W23L*!

6S2W23L*3

6S2W23M1

6S2W34M*!

Status

Located and sealed.

Filled with soil and debris.

Located and sealed.

Could not be located.

Located and sealed.

Located outside SAR boundary. Used for irrigation.

Used as a cathodic protection device by PG&E.

Located outside plume boundary. Filled with soil and debris. Could not be sealeddue to access limitations.

Located and sealed.

Could not be located. Screened only in deep aquifer (greater than 203 feet belowground surface)


Located and sealed.

Still used for irrigation. Samples from nearby wells in same aquifer show nochemicals.


H23-007 Famhild\5Y-ResionaI\EPA- Table 4-1 Potential conduits xlt (29-Nov-03) Page2of2

TABLE 4-2AMONTHLY AVERAGE PUMPING RATES (gallons per minute)

REGIONAL GROUNDWATER REMEDIATION PROGRAM SOUTH OF HWY. 101MIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VIEW, CALIFORNIA

Month/Year

February 1998March 1998April 1998May 1998June 1998July 1998August 1998September 1998October 1998November 1998December 1998January 1999February 1999March 1999April 1999May 1999June 1999July 1999August 1999September 1999October 1999November 1999December 1999January 2000February 2000March 2000April 2000May 2000June 2000July 2000August 2000September 2000October 2000

REG-1A

7.678.5110.487.998.339.838.0710.118.378.864.777.898.668.228.348.079.698.296.197.718.087.649.999.088.628.799.169.289.269.249.289.179.07

REG-10A

4.254.245.963.625.196.354.916.294.944.754.003.453.212.492.070.503.993.382.362.752.612.274.937.236.696.506.916.986.866.826.796.706.20

REG-11A

7.696.4910.077.424.615.084.214.923.903.824.434.724.834.544.634.635.054.092.873.593.533.444.214.534.644.115.165.112.622.864.023.943.48

REG-12A

12.6213.2916.7611.7313.1511.1412.3116.4412.8412.4911.267.337.085.057.0413.4215.749.936.317.967.898.2410.8412.2912.2812.7611.3313.0712.8912.8513.1013.0312.27

REG-1B1

14.0313.4817.1912.8913.8014.9717.9822.7117.4718.1522.0718.1519.2718.3618.3618.4922.5118.9414.0917.8318.7017.7423.9721.6420.5521.3919.2222.6722.4922.4422.2321.9921.33

REG-2B1

4.584.105.283.484.195.073.105.434.644.825.845.165.985.625.806.357.576.094.214.664.434.795.766.105.584.985.835.985.344.914.354.354.75

REG-3B1

3.032.844.646.827.516.234.305.104.004.165.234.014.494.224.364.254.943.832.733.083.133.135.074.594.494.654.664.694.544.494.384.153.91

REG-11B1

12.9312.4514.449.184.644.893.864.743.493.422.804.184.243.844.064.045.024.273.153.793.733.224.275.805.565.405.925.915.955.935.955.775.92

REG-1B2

2.542.693.372.623.593.923.474.463.363.444.433.233.362.702.532.603.392.872.122.842.902.623.383.343.493.763.313.663.483.452.992.993.05

REG-3B2

5.495.106.725.095.195.774.525.202.706.328.787.388.287.627.807.549.027.445.386.276.434.504.776.707.437.668.098.308.318.288.188.198.13

TOTAL

74.8373.1994.9170.8570.1973.2266.7485.4165.7070.2273.6265.5269.3962.6665.0069.8986.9269.1249.4160.4861.4457.5877.2081.3079.3379.9879.5985.6681.7481.2781.2580.2978.12

- RcgtonaKEPA - FinaI\EPA Submittal 8Dec03\EPA - Table 4-2 Pumping RatC3.xls [SI01] (07-Dec-03)



Month/Year

November 2000December 2000January 2001February 2001March 2001April 2001May 2001June 2001July 2001August 2001September 2001October 2001November 2001December 2001January 2002February 2002March 2002April 2002May 2002June 2002July 2002August 2002September 2002October 2002November 2002December 2002January 2003February 2003March 2003April 2003May 2003June 2003July 2003

REG-1A

9.079.199.029.099.139.159.118.328.918.809.038.968.949.099.098.999.008.958.948.908.988.968.898.989.299.349.199.279.289.259.069.149.13

REG-10A

5.415.905.918.665.735.665.394.694.483.773.272.311.931.051.204.795.725.535.515.435.365.264.804.203.382.326.527.407.487.337.167.187.15

REG-11A

3.553.633.975.165.694.773.862.963.233.313.203.153.203.053.953.98

L 4.004.124.054.384.744.514.484.126.545.265.436.435.866.356.505.525.43

REG-12A

12.4412.2512.2512.4312.5212.7812.2011.6312.5612.1211.8811.1211.6411.4011.2411.1911.8312.3211.8412.8313.0312.3412.0011.4911.4611.7111.7411.8011.9012.9811.167.8813.05

REG-1B1

21.9021.8921.8521.4421.3221.4219.3819.1619.8018.3119.2719.0318.0518.8918.9419.3019.3719.7620.2520.8821.8021.3121.5021.4520.2019.6018.7217.3017.3617.8315.9011.9419.90

REG-2B1

4.823.663.524.024.184.254.594.144.545.335.284.805.035.695.545.034.994.844.854.875.004.784.844.905.105.125.010.000.000.005.624.062.83

REG-3B1

3.963.964.214.724.855.104.573.723.483.143.183.893.352.792.712.712.853.303.403.403.393.613.423.405.235.845.805.705.685.655.705.825.73

REG-11B1

5.422.494.804.745.035.365.454.725.555.405.475.565.355.135.545.385.585.895.835.845.515.215.565.375.485.425.265.405.505.805.685.685.98

REG-1B2

3.663.913.953.903.974.124.043.473.743.102.742.502.492.492.452.512.522.582.462.482.492.412.442.282.462.242.262.472.302.302.041.442.35

REG-3B2

7.968.127.927.907.437.317.146.537.016.806.386.466.196.085.645.084.645.745.605.846.135.405.425.425.003.573.163.030.003.355.163.483.18

TOTAL

78.1874.9877.3982.0579.8579.9275.7269.3473.2970.0769.7067.7866.1765.6566.3068.9770.5073.0372.7274.8776.4273.8073.3371.6074.1370.4273.1068.8065.3670.8373.9862.1474.70

VttJ-OOl FurchiM\5Y - RtgwmalXEPA. • FwuREPA Submittol 8Dec03\EPA - Table 4-2 Pumping Rates.xls [S101] (07-Dec-03) Page 2 of 7



Month/Year

August 2003September 2003

Design Flow Rates

REG-1A

9.069.10

6.00

REG-10A

7.047.00

10.00

REG-11A

5.844.93

12.00

REG-12A

13.7013.28

10.00

REG-1B1

19.6215.53

15.00

REG-2B1

4.624.95

15.00

REG-3B1

5.505.28

3.00

REG-11B1

6.126.08

13.00

REG-1B2

2.242.73

3.00

REG-3B2

3.503.58

6.00

TOTAL

77.2472.43

93.00

- RegionalXEPA - FinaTiEPA Submittal 8Dec03\EPA - Table 4-2 Pumping Ratesjds [SI01] (07-Dec-03)

TABLE 4-2BMONTHLY AVERAGE PUMPING RATES (gallons per minute)

REGIONAL GROUNDWATER REMEDIATION PROGRAM NORTH OF HWY. 101MIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VIEW, CALIFORNIA

Month/Year

November 1998December 1998January 1999February 1999March 1999April 1999May 1999June 1999July 1999August 1999September 1999October 1999November 1 999December 1999January 2000February 2000March 2000April 2000May 2000June 2000July 2000August 2000September 2000October 2000November 2000December 2000January 2001February 2001March 2001April 2001May 2001June 2001July 2001August 2001September 2001October 200 1November 2001December 2001January 2002February 2002March 2002April 2002May 2002June 2002

REG-2A

8.619.457.338.5510.477.738.3810.327.917.7410.298.569.0410.778.4211.318.569.1411.348.598.8711.079.088.8411.138.609.519.619.549.139.219.429.489.409.619.629.709.679.669.569.719.709.669.66

REG-3A

17.2820.7318.0921.0825.7821.2320.5926.4720.5020.6426.6820.3921.8127.3521.6428.9721.8723.3228.9121.9322.6928.1923.1222.6528.2422.1821.0120.9419.0319.5720.1019.3820.6920.5621.0221.0921.1021.1221.0820.8421.1421.1521.1221.12

REG-4A

9.7911.698.439.6011.738.809.3312.069.399.4613.0111.0912.9416.7612.4716.7612.6813.5316.7812.6913.0816.3713.4313.1216.4712.8614.1116.4812.9614.3314.4414.7714.8514.7415.0515.1015.2015.1715.1715.0015.2015.2015.1315.15

REG-5A

9.8011.7412.0414.3217.5114.4113.9918.0113.9814.0818.1913.8914.3917.1413.4017.9613.5514.4617.9313.6014.0717.4914.3414.0410.4113.7515.1317.0917.9117.1117.2917.6917.3716.1018.0913.2117.9018.1418.1117.9118.1718.1718.1718.17

REG-6A

1.113.884.735.666.925.705.536.945.515.257.165.475.676.696.628.866.697.148.866.726.968.657.096.948.706.809.969.899.784.221.431.461.471.465.928.999.108.998.978.879.009.009.009.00

REG-7A

2.962.712.342.743.362.762.683.452.672.693.482.653.084.073.183.363.163.363.253.233.354.163.413.344.123.2710.1410.1110.019.8410.0110.057.779.9110.1410.1710.1010.1810.1510.0310.1510.1710.1410.15

REG-8A

4.394.583.344.635.754.124.275.973.943.995.215.515.716.154.095.684.494.795.944.303.494.703.863.784.733.703.984.774.874.714.604.724.714.484.224.375.004.834.974.925.005.005.005.00

REG-9A

3.624.163.494.135.094.204.045.174.004.015.163.503.243.674.926.554.905.326.583.625.507.073.081.386.955.437.974.827.887.537.617.797.837.797.967.998.107.997.977.888.008.008.008.00

REG-5B1

7.506.037.439.6111.767.569.3912.0610.0910.6713.3512.0112.4914.8211.6415.6111.7812.5815.4411.8212.2314.2912.1011.9314.9611.6612.6311.9115.6715.7215.8616.2116.3216.1816.5516.6016.5016.5616.5216.3016.5016.5716.6616.67

REG-6B1

6.888.105.946.768.216.446.588.506.626.678.586.506.498.046.889.056.857.319.066.857.068.847.257.108.896.947.667.627.587.257.317.497.545.247.637.667.807.697.687.597.707.697.667.67

REG-7B1

14.5817.4514.0116.1419.7416.2315.7620.2315.6815.7920.4015.5616.1211.5815.0820.2215.2916.2920.1915.3015.8319.6716.1415.8319.8315.5016.7819.4916.6518.7018.9718.4419.7519.041.157.7419.8019.6919.5919.3319.5819.8520.1620.16

REG-8B1

7.879.398.209.5611.709.619.3610.819.349.4013.1712.0012.9215.556.6615.5911.3912.3115.5510.7412.1514.4512.4612.2015.1111.9312.9813.6913.4812.9211.7611.8412.6914.2914.7414.3313.3013.3113.4913.3413.0513.6113.8114.19

REG-9B1

" 1.4713.6314.1912.826.100.002.654.624.504.535.854.484.647.175.605.794.374.665.784.384.545.644.624.535.684.444.984.964.932.581.451.471.471.461.830.003.003.002.992.953.003.003.003.00

REG-10B1

9.8111.728.469.589.369.629.3612.039.349.4212.179.249.6011.428.9312.019.079.6712.009.089.4011.719.599.3911.769.1810.1510.1110.049.619.769.949.979.9210.1410.1710.2010.1910.1610.0510.1910.1710.1110.13

TOTAL

105.65135.25118.03135.18153.48118.41121.90156.63123.47124.35162.71130.85138.14161.18129.53177.71134.66143.90177.61132.86139.22172.31139.58135.07166.97136.24156.99161.48160.34153.23149.78150.66151.91150.57144.06147.03166.80166.49166.50164.58166.39167.29167.62168.08

IttMBI fraAAi 5\ • • frol £TA Sutarnl KkcOim • Title « fumpmi HMO sit (NWll (OI-Dco-03) Pltelof2

TABLE 4-2B

MONTHLY AVERAGE PUMPING RATES (gallons per minute)REGIONAL GROUNDWATER REMEDIATION PROGRAM NORTH OF HWY. 101

MIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VIEW, CALIFORNIA

Month/Year

July 2002August 2002September 2002October 2002November 2002December 2002January 2003February 2003March 2003April 2003May 2003June 2003July 2003August 2003September 2003

Design Flow Rates

REG-2A

9.699.709.709.709.709.689.709.731.639.759.809.689.679.849.65

9.00

REG-3A

21.1521.1621.1621.1521.1521.1321.0021.2321.1221.1821.2321.0821.1321.1221.15

12.00

REG-4A

15.1915.2115.2115.2115.2015.1415.2015.1715.2315.2315.2515.2415.2015.2015,13

12.00

REG-5A

18.1718.1718.1818.1718.1718.1618.0018.0718.1818.0518.0818.1218.1018.1618.13

10.00

REG-6A

9.009.009.009.007.755.369.109.009.039.009.039.048.979.009.08

5.00

REG-7A

10.2010.2110.2110.116.904.964.604.404.305.532.203.924.073.903.70

6.00

REG-8A

5.004.443.582.786.096.506.506.536.554.886.536.546.506.506.50

8.00

REG-9A

8.008.008.007.998.008.008.008.038.037.988.007.967.938.068.10

3.00

REG-SB1

16.6616.4516.4216.3416.2916.6816.7016.70

|_ 16.7516.6816.6516.7616.7016.6816.63

8.00

REG-6B1

7.707.727.727.717.707.687.907.677.757.757.737.767.776.227.73

14.00

REG-7B1

20.0419.3319.3719.2819.3118.5817.5017.6017.7017.7317.6317.6817.5717.7217.70

15.00

REG-8B1

14.2812.8612.9212.7213.0115.2415.4014.779.6216.258.3514.8610.1314.0411.30

8.00

REG-9B1

3.003.003.003.004.155.005.005.035.035.055.035.024.974.965.05

14.00

REG-10B1

10.1810.2110.2010.2010.1910.1410.3010.2010.2310.1310.2310.2010.2010.3010.18

13.40

TOTAL

168.29165.45164.66163.37163.60162.25164.90164.13151.17165.15155.70163.86158.90161.70160.00

137.40

RcgionarrPA- Fin*llvEPASubtmrUl8D«c03\EPA.Tible4-2PumpingRat«xb[N101J(07-D«c-03)

TABLE 4-3BAAQMD PERMIT COMPLIANCE

REGIONAL GROUNDWATER REMEDIAL PROGRAMMIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VIEW, CALIFORNIA

SOUTH OF U.S. HIGHWAY 101 (PLANT #17205)

Date

09-Apr-9716-Dec-97Oct 2003

1997-Present

Description, Exceedance, and Duration

Permit to construct was issued.Permit to Operate was issued for the treatment system.Treatment system was modified to remove the air stripper and round the water to GACNo violations recorded

Corrective Actions

N/AN/AN/AN/A

NORTH OF U.S. HIGHWAY 101 (PLANT #11394)

Date

01-Dec-981998-Present


Permit to Operate was issued for the treatment system.No violations recorded

Corrective Actions

N/AN/A

l:\23-007 Fairchild\5Y • Reglonal\EPA - Table 4-3 & <M System Compliance.xls [BAAQMD] (02-Dec-03)

TABLE 4-4NPDES PERMIT COMPLIANCE, ORDER NO. 99-051, PERMIT NO. CAG912003

REGIONAL GROUNDWATER REMEDIAL PROGRAMMIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VIEW, CALIFORNIA

SOUTH OF U.S. HIGHWAY 101Date22-Jan-9704-Apr-971997-presen

Description, Exceedance, and DurationNotice of Intent submitted to RWQCB.NPDES permit CAG912003 was issued for the system.No violations recorded

Corrective ActionsN/AN/AN/A

NORTH OF U.S. HIGHWAY 101

Date

16-Apr-9728-May-971997-presen


Notice of Intent submitted to RWQCB.NPDES permit CAG912003 was issued for the system.No violations recorded

Corrective Actions

N/AN/AN/A

Fairchild\5Y - RegionalXEPA - Table 4-3 & 4-4 System Compliance xls [NPDES] (02-Dec-03)

TABLE 4-5RGRP TREATMENT SYSTEM OPERATION SUMMARY


South of Highway 101 Regional Groundwater Treatment System644 National Avenue, Mountain View, CA

Jan 98 - Sep 03

The groundwater treatment system began its operation in Jan 98 and has been operational since start-up. The treatment system consists of two separatetreatment systems: an air stripper and a liquid phase GAC system. Groundwater extracted from three regional recovery wells (REG-12A, REG-IB 1,and REG-1B2) is treated by three 10,000-lb liquid phase GAC vessels arranged in series while groundwater from other seven regional recovery wells(REG-1 A, REG-10A, REG-11 A, REG-2B1, REG-3B1, REG-11B1, and REG-3B2) is treated by a low profile air stripper. -The air and treatedgroundwater discharges are operated under the BAAQMD and NPDES permits, respectively.

The system was shut down from October 1 to October 20 to allow for removal of the air stripper and routing of the groundwater to the existingaqueous carbon system.

North of Highway 101 Regional Groundwater Treatment SystemCorner of Westcoat Road and McCord Avenue

Oct 98 - Sep 03

The groundwater treatment system began its operation in Oct 98 and has been operational since start-up. The extracted groundwater from the regionalrecovery wells are being treated by two low-profile air strippers connected in series. The off-gas from the first air stripper is further treated by twovapor phase GAC system before being discharged into the atmosphere under the BAAQMD discharge permit. A total of 14 regional recovery wells inthe "A" and "B 1" aquifers are being extracted and treated before discharged into the Stevens Creek under the NPDES permit.

Note:Other minor down times typically than 24 hours may have included one of the followings: extraction well development/redevelopment, carbon change out, air stripper traycleaning, and regular treatment system maintenance.

l:\23-007 FaifChlW\5Y - ReglonaAEPA - Table 4-5 TS Operatron.xls [TS summary] (Z8-Nov-03)

TABLE 6-1ACOMPARISON OF CONCENTRATIONS


Area/Aquifer

A AquiferS 101

A Aquifer N 101

Bl AquiferS 101Bl Aquifer N101

B2 Aquifer

B3 Aquifer

C&Deep Aquifer

1986/1987

2.6501

0.0005

0.0460

1992

1.6923

0.7550

7.42754.5661

1.35250.0102

0.0235

1997

0.7740

2.2881

2.6731

0.0310

1998

0.4578

0.7786

1.3497

2.2671

0.77590.0270

0.0158

1999

0.29960.6422

0.9490

2.3149

1.3226

0.0160

0.0048

2000

0.2361

0.5274

0.7745

2.0143

L 1.3536

0.0100

0.0037

2001

0.1955

0.4596

0.71111.7831

1.9148

0.00680.0032

2002

0.2194

0.4733

0.9731

1.61991.6070

0.0068

0.0039

2002/ (1986&1987)

-39%1260%-91%

2002/1992

-87%-37%-87%-65Vo19%

-33%-83%

2002/1997

-72%

-57%

-40%-78%

2002/1998

-39%

-29%

-75%

TABLE 6-1BCOMPARISON OF CONCENTRATIONS - A AQUIFER SOUTH OF HWY 101MIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VIEW, CALIFORNIA

Location ID

109A142A144A153 A162 A1A20A21A22A26A29A42A45A54A62A77A78A79A99AIM9AR22AR24AR25AR29AR31AR32AR43AR46AR57AR59AREG-10AREG-1 1 AREG-12AREG-1AREG-MW-1AREG-MW-2ARW-9ASIL12ASIL4A

Number of Samples

Average Concentration

1986/1987.

1.7863

0.0013

0.04574.70000.00200.0020

45.1667

6.2117

1.2525

9

1992

1.8000

0.00100.1233

0.18000.0010

0.00160.00109.00000.0100

24.00006.70000.00100.00100.00810.06400.02200.00100.00100.00100.01200.01250.25000.00500.00100.06400.8300

2.6000

1997

0.3500

0.00050.0160

0.14000.00050.04250.5600

0.00311.00000.018015.50000.75000.00050.00050.0590

0.04000.0005

0.00050.00050.06800.13000.00310.00050.03500.24000.42000.16000.45000.15000.33003.30001.0000

1998

0.24000.17000.00050.0200

0.19000.00050.05700.18350.04800.00220.78000.03403.95002.36670.00050.00050.05800.53000.06400.00050.01300.00050.00050.07850.16000.00540.00060.03300.23000.18500.47000.37000.16000.48004.15001.4500

1999

0.23000.20000.00050.0170

0.17000.00050.06800.29500.06400.00220.65000.03351.07501.45000.00050.00050.04800.48000.08100.00050.01600.00050.00050.06700.14000.00500.00110.03100.20000.18000.34000.26500.14500.08753.40001.0400

27 j 32 j 36 | 36i i

11.6923

10.7740 0.4578 j 0.2996

2000

0.18000.14000.00050.01500.00950.15000.00050.07900.24000.07100.00180.57000.01200.61000.30000.00050.00050.03400.48000.08300.00050.01800.00050.00050.06500.12000.00430.00070.03000.11000.16000.28000.24000.14000.09003.40000.90000.49000.1800

2001

0.17000.19000.00050.01100.01000.17000.00050.07500.21000.03700.00150.52000.01101.10000.25500.00050.00050.03200.42000.08100.00050.01600.00050.00060.07800.11000.00420.00120.02900.16500.11000.25000.19000.11000.09301.90000.67000.47000.1300

39 | 39

0.2361 i 0.1955

2002

0.13000.22000.00050.01300.00740.14000.00050.07900.20000.04300.00160.62000.00900.89000.41500.00050.00050.03800.49500.07700.00050.01900.00050.00050.15000.14000.00490.00240.03200.18000.12000.25000.20000.12000.03602.50000.67000.61000.1400

39

0.2194

TABLE 6-1CCOMPARISON OF CONCENTRATIONS - A AQUIFER NORTH OF HWY 101MIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VIEW, CALIFORNIA

Location ID

14D02A14D09A14D14A14E14A15H05A65A72A73A74A75A81A82A88A89A92A93A95APZ 9.5-6(Al)REG-2AREG-3AREG-4AREG-5AREG-6AREG-7AREG-8AREG-9AW12-6W60-2W89-1W9-16W9SC-20WT14-1WU4-1WU4-16WU4-18WU4-3

Number of Samples


1986/1987 .

0

1992

0.00100.05200.00100.00410.00104.40000.02600.11000.04200.13000.68002.50000.02800.75000.00100.00250.0210

0.00250.59751.70000.1500

0.00132.92000.02850.00665.4750

26

0.7550

1997

0.00050.05000.00260.00070.0005

5

1998

0.00050.06100.00390.00050.00051.70000.02500.68000.09300.05000.51002.30000.02800.27000.00070.00270.02202.50001.60000.86003.80003.20000.36910.45000.19000.31000.00050.27000.46000.6800

0.00053.00000.01200.00053.8000

35

0.7786

1999

0.00050.05530.00340.00050.00061.17330.01800.81330.08400.03870.33001.60330.02450.38000.00060.00250.01362.70001.19331.16672.36672.23330.30400.72000.50330.27330.00050.26000.38500.5100

0.00052.83330.00580.00192.4761

35

0.6422

2000

0.00090.04900.00220.00100.00050.75500.02000.97000.06400.03450.11000.70000.02500.39000.00050.00240.03151.70000.84500.97501.70001.80000.32500.60500.47500.21500.00050.22000.03400.4450

0.00052.00000.01050.00053.9500

35

0.5274

2001

0.00090.04500.00130.00050.00050.59000.01600.67000.04700.03600.09701.20000.01700.28000.00050.00230.02901.00000.67000.69001.40001.40000.23000.43000.44000.16000.00050.20000.00200.33672.45000.00051.80000.00090.00052.3000

36

0.4596

2002

0.00050.0480

0.00060.00060.73000.02600.80000.05800.11000.14000.88000.01600.36000.00050.00250.03601.10000.7600 JJ0.8200^1.9000 I1.50000.29000.65000.41000.17000.00050.23000.02500.00191.69750.00051.70000.00140.00052.1000 ||

35

0.4733

TABLE 6-1DCOMPARISON OF CONCENTRATIONS - Bl AQUIFER SOUTH OF HWY 101MIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VIEW, CALIFORNIA

Location ID

103B1105B1112B1119B1122B1124B112B113B1140B1143B114B126B132B133B156B174B177B18B191B192B198B1I9B1IM5B(1)IM9B(1)ME1B1ME2B1NEC14B1NEC18B1NEC8B1R13B1R22B1R40B1(B2)R46B1R6B1REG-1 1B(1)REG-lB(l)REG-2B(1)REG-3B(1)REG-4B(1)REG-MW-lB(l)REG-MW-2B(1)RP22BRW-l(Bl)

1986/1987 .

2.88042.97503.3071

0.0013

11.7875

2.23931.04900.4813

0.2321

0.0010

0.0023

1992

0.33000.86000.97001.40000.00100.00107.50000.13000.0120

140.00000.12000.0010

70.00000.18150.00100.001214.00000.25450.58000.07800.34000.0010

0.01000.01200.00441.16330.02500.20000.00100.0010

0.2000

1997

0.00180.67000.5100

0.00050.0005

0.01900.0005

29.00000.01320.000521.00000.00420.00050.00108.60000.00170.21000.21000.19000.0024

0.01200.00050.01700.35000.00150.05450.00050.00050.00190.07700.00050.330015.00000.46001.7000

i 1.9000

1998

0.06500.63000.31000.85000.00050.0005

0.40950.001417.00000.11000.00053.43330.00730.00050.00168.00000.20000.20000.19000.16000.00520.00220.01100.00140.02100.35000.01400.00590.00050.00050.00260.05200.00051.37006.16670.20502.10000.18671.2767

! 0.6700 i 0.9550

1999

0.00060.80000.21000.56000.00050.0005

0.79500.007210.77500.13000.00051.50000.00820.00050.00073.40000.02900.20000.19000.13000.00220.00410.00800.00360.01100.28500.00890.00230.00070.00050.00150.09300.0005

2000

0.02600.58000.18000.56000.00050.00052.25000.92000.00707.05000.11000.00050.77000.02500.00050.00053.20000.00190.12000.19000.11000.00520.02650.00770.00440.01500.25000.00050.00140.00050.00050.00190.06900.0005

0.6450 i 0.60006.4500 i 5.90000.1850 ! 0.13001.7500 ' 1.60000.1800 0.18000.8300 0.9200

2001

0.08900.46000.17000.64000.00050.00052.10000.94000.00549.20000.10000.00050.92000.05200.00050.00221.90000.13000.07100.16000.10000.00270.03450.00690.00440.02100.20000.00480.0280

0.00050.00060.08300.00050.48004.30000.14001.50000.1800

2002

0.15000.55000.17000.94000.00050.00052.40000.70000.011018.00000.11000.00050.69000.04600.00050.00721.60000.19000.17000.17000.16000.00320.01150.00720.00600.02400.27000.00940.04000.0005

0.00540.07500.00070.52005.30000.16001.60000.1900

0.6600 i 0.17000.9000 0.6800 0.5200 [ 1.2000

0.0060 ' 0.0008 ! 0.0005 ' 0.0005 | 0.0005 i 0.0005 ! 0.0005 i 0.0005j 0.2320 | 0.2000 j 0.2050 0.1850 , 0.1300 0.1900 1 0.1900

TABLE 6-1DCOMPARISON OF CONCENTRATIONS - Bl AQUIFER SOUTH OF HWY 101MIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VIEW, CALIFORNIA

Location ID

RW-2(B1)RW-9(B1)R

1986/1987 .

Number of Samples 12


1992

3.850017.5000

35

7.4275

1997

1.100011.5000

41

2.2881

1998

0.550014.3333

44

1.3497

1999 2000

0.4400 j 0.425011.0333 I 7.8000

44

0.9490

45

0.7745

2001

0.39005.5000

44

0.7111

2002

0.46506.5000

44

0.9731

TABLE 6-1ECOMPARISON OF CONCENTRATIONS - Bl AQUIFER NORTH OF HWY 101MIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VEEW, CALIFORNIA

Location ID

139B1154B1155B146B147B148B149B150B168B178B179B181B183B187B1PZ 9.5-5(A2)REG-lOB(l)REG-5B(1)REG-6B(1)REG-7B(1)REG-8B(1)REG-9B(1)W89-11W89-12W89-13W89-14W9-17W9-25WNB-14WU4-12WU4-13WU4-19WU4-2WU4-4WU4-5WU4-6WU4-7

Number of Samples


1986/1987 .

0

1992

0.0010

1997

11.35050.02800.00100.00100.0010

0.22000.00100.00100.00100.0450

0.00152.34000.11700.00134.45002.05000.00881.77500.01750.005954.750021.000012.350015.75002.4500

26

4.5661

0

1998

0.0005

0.95000.00420.00050.00050.00113.10000.29000.00230.00050.00050.03704.50000.15002.35004.20001.40001.80001.30710.00053.40000.07060.00537.30001.20000.04200.91000.00050.059016.500013.00007.30006.10001.1000

34

2.2671

1999

0.0005

2.10000.00710.00050.00050.00052.07670.28670.00120.00050.00050.04705.13330.16673.26675.18001.73331.16670.63000.00052.17330.02300.00074.92500.89000.02680.81330.00050.190018.66679.50006.91677.25005.5333

34

2.3149

2000

0.0005

1.75000.00160.00050.00050.00052.15000.29500.00060.00050.00050.06305.30000.13502.00004.93331.55001.05000.72000.00052.75000.01300.00053.13330.72500.04300.66500.00050.130016.00006.75005.10007.52505.7000

34

2.0143

2001 j 2002

0.00072.20000.08201.30000.00260.00050.00100.00051.70000.23000.00070.00050.00050.05707.10000.11002.20003.95001.20000.96000.75000.00051.80000.09800.00052.80000.48000.04700.49000.00050.130017.50006.30003.40005.30004.0000

36

0.00050.36000.11002.00000.00300.00050.00050.00051.50000.28000.00080.00050.00130.07008.40000.14002.20004.70001.40001.30001.00000.00052.55000.01500.00080.12000.25000.00210.62000.00050.190011.00007.00003.10006.40003.6000

36

1.7831 1.6199

TABLE 6-1FCOMPARISON OF CONCENTRATIONS - B2 AQUIFER


Location ID

10B2113B2125B2129B2132B2134B215B216B236B237B238B243B262B26B275B276B289B2NEC18B2NEC8B2R13B2R30B2R41B2R50B2R52B2R55B2REG-1B(2)REG-3B(2)REG-MW-1B(2)RW-5(B2)RW-7(B2)RW-9(B2)

Number of Samples


1986/1987

0.00440.0033 ,0.00200.00390.01210.00070.00051.5000

62.00000.00051.70000.00370.00050.00730.00170.00133.0833

0.00090.00100.04630.48200.00300.00270.0010

0.00820.0317

26

2.6501

1992

0.0007

0.0010

0.00100.4150

25.00000.00101.07000.00100.00150.00100.00120.00860.77000.02900.00210.00100.08400.7100

0.00100.0010

0.3025

21

1.3525

1997

4.70002.00000.0005

0.31000.00110.00050.2200

37.00000.00050.50000.00050.00050.00690.00050.00550.66000.00600.00050.00050.00830.0290

0.00740.0005

25.00000.44000.9503

0.3250

27

2.6731

1998

L 2.46678.96670.00060.00050.00510.00050.00050.19001.09000.00050.50500.00050.00050.00720.00050.00490.67000.03800.00050.00050.01200.21000.00090.00460.00057.55000.53500.0005

0.2400

29

0.7759

1999

10.80006.45000.00050.00050.00430.00050.00050.13006.86670.00050.37500.00050.00050.00280.00050.00110.30000.03400.00050.00050.00850.19000.00070.00280.001715.00000.38000.00050.00140.01700.4300

31

1.3226

2000

11.75006.45000.00050.00050.00260.00050.00050.14002.15000.00050.36000.00050.00050.00100.00050.00060.13000.02300.00050.00050.00910.14000.00050.00170.000517.00000.38000.0005

0.7100

29

1.3536

2001

0.32103.65000.00050.00050.00280.00050.00050.1300

37.50000.00050.30000.00050.00050.00160.00050.00050.15000.01400.00050.00050.00500.10000.00050.00180.000516.00000.26000.00170.00060.00380.9100

31

1.9148

2002

0.78001.40000.00050.00050.00350.00050.00050.1600

22.66670.00050.36000.00050.00050.00510.00060.00090.16000.07900.00050.0005 I

I0.0780 10.0005 |0.00180.0007

21.00000.30000.00050.00110.00601.2000

30

1.6070

TABLE 6-1GCOMPARISION OF CONCENTRATIONS - B3 AQUIFER


Location ID

65B3

Number of Samples


1986/1987 .

0.0005

1

0.0005

1992

0.01015

1

0.0102

1997

0.031

1

0.0310

1998

0.027

1

0.0270

1999

0.016

1

0.0160

2000

0.01

1

0.0100

2001

0.0068

1

0.0068

2002

0.0068

1

0.0068

TABLE 6-1HCOMPARISON OF CONCENTRATIONS - C & DEEP AQUIFER


Location ID

DW3-219DW3-244DW3-334DW3-364

Number of Samples


1986/1987 •

0.02070.05870.09320.0115

4

0.0460

1992

0.00280.01900.05300.0190

4

0.0235

1997

0

1998

0.00260.00560.02800.0270

4

0.0158

1999

0.00080.00090.00920.0082

4

0.0048

2000

0.00060.00100.00780.0056

4

0.0037

2001

0.00070.00090.00630.0050

4

0.0032

2002

0.00090.00090.00680.0071

4

0.0039

TABLE 6-2ATRICHLOROETHENE (TCE) AND VOLATILE ORGANIC COMPOUND (VOC) MASS REMOVAL

REGIONAL GROUNDWATER TREATMENT SYSTEM - SOUTH OF U.S HIGHWAY 101MIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VIEW, CALIFORNIA

Granular Activated Carbon Treatment

MonthJan-98Feb-98Mar-98Apr-98May-98Jun-98Jul-98

Aug-98Sep-98Oct-98Nov-98Dcc-98Jan-99Feb-99Mar-99Apr-99May-99Jun-99Jul-99

Aug-99Sep-99Oct-99Nov-99Dcc-99Jan-00Feb-00Mar-00Apr-00

AverageInfluent TCEConcentration

(mg/L)13.59.17.26.25.95.76.04.75.04.84.65.35.66.65.95.34.84.95.75.55.45.65.63.03.03.43.93.4

AverageInfluent VOCConcentration

(mg/L)13.89.47.66.56.25.86.44.85.65.14.75.65.96.96.35.65.15.16.05.95.86.06.03.33.13.74.33.8

AverageFlow Rate

(gpm)19.941.837.33.532.230.326.842.141.642.339.335.231.330.328.729.937.636.433.532.332.430.532.644.651.655.557.156.4

TotalMonthly

Flow(gal/month)

889,7691,683,9281,667,151152,763

1,438,1871,308,4771,196,5571,878,8211,796,0011,886,5431,698,7451,571,1781,396,8731,221,6091,280,8341,293,6441,680,1271,572,9601,493,5701,441,0641,397,9611,363,0281,408,2111,989,3392,302,1672,235,8942,549,9502,438,564

TCE MassRemovedper Day

(gram/day)

1,4672,0721,466120

1,036941877

1,0791,1331,106986

1,017955

1,090923865985973

1,040968953932995729844

1,0281,2151,046

Total TCEMass

Removed(kg/month)

45.558.045.43.632.128.227.233.434.034.329.631.529.630.528.626.030.529.232.230.028.628.929.922.626.128.837.731.4

CumulativeTCE

Removed(kg)45103149153185213240274308342371403433463492518548577610640668697111750776804842874

VOC MassRemovedper Day

(gram/day)

1,5002,1401,548125

1,089958935

1,1011,2691,1751,0081,0751,0071,140986914

1,0471,0121,0951,0381,023999

1,066802870

1,1041,3341,164

Total VOCMass Removed

(kg/month)

46.559.948.03.8

33.828.729.034.138.136.430.233.331.231.930.627.432.430.433.932.230.731.032.024.927.030.941.434.9

CumulativeVOCs

Removed(kg)46106154158192221250284322358389422453485516543575606640672703734766790817848890925

1 \97-l83UWH\RORP Performance CvalualionXApp I - Treatment Mass Removals xls [S101 OAC] (18-May-OO) Page 1 of2




MonthMay-00Jun-00Jul-00Aug-00Sep-00Oct-00Nov-00Dcc-00Jan-01Feb-01Mar-01Apr-01May-01Jun-01Jul-01

Aug-01Sep-01Oct-01Nov-01Dec-01Jan-02Feb-02Mar-02Apr-02May-02Jun-02Jul-02Aug-02


(mg/L)

4.73.53.83.63.53.04.44.14.24.64.34.04.64.04.43.93.63.54.23.53.53.64.14.54.83.93.73.8


(mg/L)

5.03.84.13.73.63.24.74.24.34.94.64.64.94.44.74.13.73.84.43.63.63.84.44.75.14.14.04.1

AverageFlow Rate

(gpm)57.356.353.750.852.645.735.034.135.734.534.239.732.728.731.029.229.428.327.827.428.629.928.731.331.430.729.828.8

TotalMonthly

Flow(gal/month)

2,557,9332,433,9852,397,3722,269,6132,273,4172,037,8811,511,8281,521,4831,595,8201,392,8821,528,6271,715,2661,459,3891,238,8001,382,6171,303,4371,269,6681,264,7431,200,3391,221,7051,277,0471,207,3711,279,0281,354,0011,400,3161,326,4411,328,5991,287,805


(gram/day)

1,4681,0751,113998

1,004747840762819866805866820625743621577541636522546588640768821653600598

Total TCEMass

Removed(kg/month)

45.532.334.530.930.123.125.223.625.424.324.926.025.418.823.019.217.316.819.116.216.916.519.923.125.419.618.618.5

CumulativeTCE

Removed(kg)919951986

1,0171,0471,0701,0951,1191,1441,1681,1931,2191,2451,2641,2871,3061,3231,3401,3591,3751,3921,4091,4281,4511,4771,4961,5151,534


(gram/day)

1,5681,1591,2041,0291,037807893775836924865985873693794653593580667531562620687802872686643639


(kg/month)

48.634.837.331.931.125.026.824.025.925.926.829.527.120.824.620.217.818.020.016.517.417.421.324.127.020.619.919.8

CumulativeVOCs

Removed(kg)973,008,045,077,108,133,160,184,210,236

1,2631,2921,3191,3401,3651,3851,4031,4211,441,457,475,492,513,537,564,585

1,6051,625

nw^^uiiUWIfvRGRP Performance EvaluationXApp I - Treatment Mass Removalsjds (S101 GAC] (18-May-OO)




MonthSep-02Oct-02Nov-02Dcc-02Jan-03Feb-03Mar-03Apr-03May-03Jun-03Jul-03

Aug-03Sep-03


(mg/L)

3.94.25.34.24.84.33.64.33.82.32.02.43.2


(mg/L)

4.24.55.64.55.14.63.84.64.52.92.52.93.5

AverageFlow Rate

(gpm)33.834.333.931.433.428.631.436.149.446.760.459.727.3

TotalMonthly

Flow(gal/month)

1,459,5111,529,5401,464,8451,403,8021,488,9461,153,6031,400,9741,561,2592,203,8552,015,7442,694,1722,663,2001,180,960


(gram/day)

718785980720873671616847

1,023585658781477

Total TCEMass

Removed(kg/month)

21.624.329.422.327.118.819.125.431.717.620.424.214.3

CumulativeTCE

Removed(kg)1,5551,5801,6091,6311,6581,6771,6961,7221,7531,7711,7911,8151,830


(gram/day)

775841

1,035772919711658904

1,217730820953518


(kg/month)

23.326.131.123.928.519.920.427.137.721.925.429.515.6

CumulativeVOCs

Removed(kg)1,6481,6741,7051,7291,7571,7771,7981,8251,8631,8851,9101,9391,955

I \97-183VWir\RGRP Performance Cvaluation\App I - Treatment Mass Removals xls [S101 GAC] (18-May-OO) Page 1 of2

TABLE 6-2BTRICHLOROETHENE (TCE) AND VOLATILE ORGANIC COMPOUND (VOC) MASS REMOVAL

REGIONAL GROUNDWATER TREATMENT SYSTEMMIDDLEFIELD-ELLIS-WHISMAN SITE, MOUNTAIN VIEW, CALIFORNIA

Air Stripper Treatment

MonthJan-98Feb-98Mar-98Apr-98May-98Jun-98Jul-98

Aug-98Sep-98Oct-98Nov-98Dcc-98Jan-99Fcb-99Mar-99Apr-99May-99Jun-99Jul-99

Aug-99Sep-99Oct-99Nov-99Dec-99Jan-00Feb-00Mar-00Apr-00


(mg/L)

0.50.70.80.80.90.90.70.60.60.60.60.60.60.60.60.50.60.50.60.50.50.50.50.50.40.50.50.5


(mg/L)0.50.70.80.90.90.90.70.60.70.70.60.70.70.60.60.60.60.50.60.50.50.50.50.60.50.50.50.6

AverageFlow Rate

(gpm)32.648.355.052.953.742.939.837.835.834.738.830.942.341.240.439.940.041.540.037.235.632.932.633.039.640.641.839.6

TotalMonthly

Flow(gal/month)

1,456,6911,946,9452,453,1122,284,2592,397,8771,853,9331,775,0031,686,2291,544,9191,548,4371,674,7651,378,6621,889,2471,660,7231,803,5141,723,6461,783,8331,792,3501,787,4201,659,2521,538,7431,469,6521,407,7391,474,9411,766,6091,627,7821,855,9981,697,553


(gram/day)

85171225234255199145122115113116104141130128113120109120958788878895106114110

Total TCEMass

Removed(kg/month)

2.64.87.07.07.96.04.53.83.53.53.53.24.43.64.03.43.73.33.73.02.62.72.62.72.93.03.53.3

CumulativeTCE

Removed(kg)

3714212935404447515457626569737680838689929497100103106110


(gram/day)

9318424625126919915613013512512711115013914112612911312710593979699105115125122


(kg/month)

2.95.27.67.58.46.04.84.04.03.93.83.44.63.94.43.84.03.43.93.32.83.02.93.13.33.23.83.6

CumulativeVOCs

Removed(kg)

381623323742465054586266707478828690939699101105108111115118

H ,RGRP Performance EvaluatioAApp I - Treatment Mass Removals.xlj [S101 Air] (18-May-OO)




MonthMay-00Jun-00Jul-00Aug-00Scp-00Oct-00Nov-00Dcc-00Jan-01Fcb-01Mar-01Apr-01May-01Jun-01Jul-01Aug-01Sep-01Oct-01Nov-01Dec-01Jan-02Feb-02Mar-02Apr-02May-02Jun-02Jul-02Aug-02


(mg/L)

0.40.40.50.50.40.40.40.40.40.50.50.40.50.40.30.40.40.40.50.40.40.40.40.40.40.40.30.4


(mg/L)

0.50.50.50.50.50.60.50.50.40.50.50.50.50.50.30.40.40.40.40.40.40.40.40.40.50.50.40.4

AverageFlow Rate

(gpm)39.336.338.541.437.833.834.732.835.736.838.035.033.131.333.834.432.730.232.432.831.533.833.135.229.932.930.133.3

TotalMonthly

Flow(gal/month)

1,754,0851,568,9971,692,8761,800,4021,633,0741,483,0071,498,9261,414,5281,592,9311,483,1981,697,2631,511,6241,477,9711,353,6601,509,1281,535,1611,414,3211,347,8661,401,4871,462,7551,407,6501,362,8991,476,1721,520,1591,335,9831,422,4761,342,7411,487,715


(gram/day)

9087101104876876757890958586775769696479646068637772775673

Total TCEMass

Removed(kg/month)

2.82.63.13.12.62.12.32.22.42.53.02.62.72.31.82.12.12.02.42.01.91.92.02.32.22.31.72.3

CumulativeTCE

Removed(kg)112115118121124126128130133135138141144146148150152154156158160162164166168171173175


(gram/day)

999410711194118858184991049293826475746978686576698678836278


(kg/month)

3.12.83.33.42.83.62.62.42.62.83.22.82.92.52.02.32.22.12.32.12.02.12.12.62.42.51.92.4

CumulativeVOCs

Removed(kg)122124128131134137140142145148151154157159161163166168170172174176178181183186188190

l.W-l«3UWH*GRP Performance EvaluatiomApp I - Treatment Mass Removalsjils [SIOI Air] (18-May-OO) Page 2 of2




MonthSep-02Oct-02Nov-02Dec-02Jan-03Feb-03Mar-03Apr-03May-03Jun-03Jul-03

Aug-03Scp-03

AverageInfluent TCE

Concentration(mg/L)

0.40.40.50.50.50.50.40.50.50.40.40.40.4


(mg/L)

0.40.40.50.50.60.50.50.50.50.40.40.40.4

AverageFlow Rate

(gpm)33.831.433.730.741.738.532.136.845.540.640.240.239.5

TotalMonthly

Flow(gal/month)

1,461,7581,402,7461,457,2081,371,1261,862,6251,551,8531,431,5401,587,7342,029,8541,752,6501,792,7461,794,1251,704,583


(gram/day)

686788851231037710012191778580

Total TCEMass

Removed(kg/month)

2.02.12.62.63.82.92.43.03.82.72.42.62.4

CumulativeTCE

Removed(kg)177179182184188191193196200203205208210


(gram/day)

767094901311118510813099839388


(kg/month)

2.32.22.82.84.13.12.63.24.03.02.62.92.6

CumulativeVOCs

Removed(kg)193195197200204207210213217220223226228

vVHXRGRP Performance EvaluationVApp I - Treatment Mass Removals xls [S10I Air] (18-May-OO)

TABLE 6-2CTRICHLOROETHENE (TCE) AND VOLATILE ORGANIC COMPOUND (VOC) MASS REMOVAL

REGIONAL GROUNDWATER REMEDIATION PROGRAMMIDDLEFIELD-ELLIS-WHISMAN SITE, NORTH OF U.S. HIGHWAY 101


MonthOct-98Nov-98Dec-98Jan-99Feb-99Mar-99Apr-99May-99Jun-99Jul-99

Aug-99Sep-99Oct-99Nov-99Dec-99Jan-00Feb-00Mar-00Apr-00May-00Jun-00Jul-00

Aug-00Scp-00Oct-00Nov-00


(mg/L)

1.71.61.61.41.41.61.51.61.61.41.51.51.41.51.41.31.51.51.41.41.51.31.31.31.31.3


(mg/L)

1.91.81.81.61.61.91.71.81.81.61.81.81.71.71.61.51.71.71.71.71.71.51.51.51.61.5

AverageFlow Rate

(gpm)60.6112.8122.9145.1127.1139.6127.6134.8133.2135.0134.4136.5139.9142.7137.0145.2146.3146.4150.5149.7138.5151.1149.4144.0141.4144.2

Total Monthly Flow(gal/month)

2,616,0304,871,7605,488,2806,476,5615,125,1796,230,8705,510,7706,015,5905,753,6706,024,2605,999,0305,897,3306,243,9706,165,3106,116,0906,482,6206,111,0406,535,3106,502,3306,684,3305,981,3506,746,7706,670,8506,220,7306,313,8206,230,990


[gram/day)

561984

1,0731,107970

1,2181,0431,1761,1621,0301,0991,1161,0681,1671,0461,0291,1971,1971,1491,1431,1321,0711,0591,0211,0021,022

Total TCEMass

Removed(kg/month)

16.829.533.234.327.237.731.336.434.931.934.133.533.135.032.431.934.737.134.535.434.033.232.830.631.130.7

CumulativeTCE

Removed(kg)

174680114141179210247281313347381414449481513548585620655689722755786817847


(gram/day)

6271,1071,2071,2661,1091,4461,1821,3231,3071,1771,3191,3401,2961,3231,1951,1881,3561,3571,3951,3881,2831,2701,2461,1931,2081,201


(kg/month)

18.833.237.439.231.044.835.541.039.236.540.940.240.239.737.136.839.342.141.943.038.539.438.635.837.536.0

CumulativeVOCs

Removed(kg)195289129160205240281320357398438478518555592631673715758796836874910948984

U97-183\N101 2Y-RPTWPP-H Mass RemovaftTable 6-2 VOC Removal WITH FORMULAS.xls




Month

Dec-00Jan-01Feb-01Mar-01Apr-01May-01Jun-01Jul-01Aug-01Sep-01Oct-01Nov-01Dec-01Jan-02Feb-02Mar-02Apr-02May-02Jun-02Jul-02

Aug-02Sep-02Oct-02Nov-02Dec-02Jan-03


(mg/L)

1.41.41.11.31.21.31.41.31.31.31.11.21.11.11.11.31.11.21.31.21.11.21.41.21.31.3


(mg/L)

1.61.61.31.51.51.51.61.51.51.51.41.41.31.31.31.51.31.41.51.41.31.41.61.41.51.6

AverageFlow Rate

(gpm)

147.5148.0152.6149.0144.6142.7137.3140.5141.2138.9149.3164.4162.3165.4157.8141.5142.8156.0164.0157.4153.0160.6161.0153.0147.4163.0


6,584,1706,606,7106,154,0506,649,5006,247,8106,372,0505,930,1536,273,5776,303,9506,000,4976,662,7837,102,3007,246,9107,306,4046,363,7356,318,5406,169,1066,963,5807,084,8907,027,8446,828,8226,937,7347,187,4506,614,0416,435,9417,276,320


(gram/day)

1,1261,130915

1,056946

1,0121,0481,0191,001949919

1,076973992946972872

1,0211,1621,030918

1,0511,2291,0011,0291,155

Total TCEMass

Removed(kg/month)

34.935.025.632.728.431.431.431.631.028.528.532.330.230.426.530.126.231.634.931.928.431.538.130.131.235.8

CumulativeTCE

Removed(kg)

8829179439761,0041,0361,0671,0991,130,158,187,219,249,279,306

1,3361,3621,3941,4291,4611,4891,5211,5591,5891,6201,656


(gram/day)

1,3261,3011,0891,2511,1551,1441,1681,1721,1551,1281,1121,2821,1631,1721,1181,1571,0491,2251,3411,2011,0841,2261,4041,1681,2051,386


(kg/month)

41.140.330.538.834.635.535.036.335.833.934.538.536.136.031.335.931.538.040.237.333.636.843.535.136.643.0

CumulativeVOCs

Removed(kg)

1,0251,0651,0961,1341,1691,2041,2391,2761,3121,3451,3801,4181,4541,4901,5221,5581,5891,6271,6671,7041,7381,7751,8181,8531,8901,933

,N101 2Y-RPT\APP-H Mass RemovalYTable 6-2 VOC Removal WITH FORMULAS.xls




Month

Feb-03Mar-03Apr-03May-03Jun-03Jul-03

Aug-03Sep-03


(mg/L)

1.21.11.31.31.21.11.11.0


(mg/L)

1.41.31.51.51.51.31.31.2

AverageFlow Rate

(gpm)

144.6164.8128.4116.5201.1114.3152.6131.5


5,831,6307,355,6305,547,2005,198,7308,688,1105,102,1406,813,8305,681,790


(gram/day)

946988910825

1,316685915717

Total TCEMass

Removed(kg/month)

26.530.627.325.639.521.228.421.5

CumulativeTCE

Removed(kg)

1,6821,7131,7401,7661,8051,8271,8551,876


(gram/day)

1,1251,1701,081967

1,609825

1,108892


(kg/month)

31.536.332.430.048.325.634.326.8

CumulativeVOCs

Removed(kg)

1,9652,0012,0332,0632,1112,1372,1712,198

I:\97-183\N101 2Y-RPTVAPP-H Mass RemovaOTable 6-2 VOC Removal WITH FORMULAS.xls

\

FIGURES \

LIMITS OF REGIONALSTUDY AREA

N.A.S.A. //AREA //

I

STE LOCATION MAPMOUNTAIN VIEW. CALIFORNIA

PREPARED FOR

FAIRCHILDSEMICONDUCTOR CORP.

A 2 APR 03

No. DATE

ISSUED FOR REPORT

ISSUE / REVISION

vzc

1HH. BY CIO) BTAP-D BY

LocusT E C H N O L O G I E S

DOWIM NO. I 87-023-A45

FIGURE 1-1

-V

<,.<**>•¥

V•V

SBX

I

•V369-399 N. WHISMAN ROAD

AOL NETSCAPE2 STORIES

-V

515 N. WHISMAN ROADVERITAS

2 STORIES

LEGEND:

(T) RAYTHEON COMPANY

(5) INTEL CORPORATION

(5) FAIRCHILD SEMICONDUCTOR CORPORATION

(7) NEC ELECTRONICS, INC.

(?) SUMITOMO MITSUBISHI SILICON CORPORATION/^ VISHAY GENERAL SEMICONDUCTOR. INC.

(T) SMI HOLDING LLC

PROPERTY BOUNDARIES

• SLURRY WALL

O.005

545 N. WHISMAN ROADNOKIA

2 STORIES

365 E. MIDDLEFIELD ROADENERGY SALES/OPEN TV1 STORY

401 E. MIDDLEFIEUTROADOPEN TV , _1 STORY

'415 E. MIDDLEFIELD ROADOPEN TV1 STORY

455 E. MIDDLEFIELD ROADVERISIGN1 STORY

487 E. MIDDLEFIELD ROADVERISIGN2 STORIES

«o* -V

401 NATIONAL AVEy ADEMA

L A.

EQUIPMENT CORP.

PROPERTIES3 IV, Lfc

' ^ 3bo-380 ELLISVERITAS

3 AT 4 STORIES AND -468LEfcbteSTR£01 AT 1 STORY AOL NETSCApE

2 AT 2 STORIES AND1 AT 3 STORIES

313 FAIRCHILD DRIVENOKIA

2 STORIES

323 FAIRCHILD DRIVENOKIA

2 STORIES

ISSUED FOB REPORT

ISSUE/ REVISION own Err aco BY

MEW COMPANIES FORMER FACILITIESSOUTH OF U.S. HIGHWAY 101MOUNTAIN VIEW, CALIFORNIA

PREPARED FOR

MEW COMPANIES

Locus DrWNMO NO. 23-007-E2

FIGURE 1-2K.\Z3-OOAE2£IK> 12 WK 03

KS .101.

\

N2U

ARNOLD A

H2+1 K223

BLDG 48 AREA

CRAFT HOBBYSHOP AREA

FORMERAUTO HOBBYSHOP AREA

j ••« (BLDG 88 AREA)

t ^ 223

«' «*&,

t >TT

EXPANDEDSITE 9 AREA

- HARDING UWSON ASSOCIATES 1933•SUMMARY OF POTEHTW. SOURCEAREAS N»S MOfFETT FIELDSANTA CLARA COUNIY CAUFORNH."

EXPANDEDSITE 8 AREA

BLDG 144 AREA

K:\23-QOAE5S-OWC 12-01-05

No. DATE

ISSUED FOR Fr£ YEM REVIEW

ISSUE/ REVISION OWN BY APD BY

BUILDINGS AND SITE PLAN

NORTH OF U.S. HIGHWAY 101


PREPARED FOR

INTEL CORPORATION ANDRAYTHEON COMPANY


[ 23-007-E58

FIGURE 1-3

LEGEND:

© PROPERTY LOT NUMBER

PROPERTY LINE

1. THE OWNERS AND/OR OCCUPANTS OF MANYFACILITIES HAVE CHANGED DURING THEHISTORY OF THE AREA, AND THIS SITUATIONIS EXPECTED TO CONTINUE, WITH LITTLE ORNO PUBLIC NOTICE, IN THE FUTURE. THEINFORMATION SHOWN ON THIS MAP ISBELIEVED TO BE REPRESENTATIVE OFCONDITIONS FROM LATE 1988 TO EARLY 1988.

FORMER BUILDINGS AND OCCUPANTS(CIRCA 1987)

BUILDING OCCUPANTSMOUNTAIN VIEW, CALIFORNIA

PREPARED FOR


LocusT E C H N O L D G I E S

300 000 FEET

23-007-E57

FIGURE 3-1fc\23-007\e57.DWG 25 NCV 03

INTEL TREATMENT SYSTEM(CARBON ADSORPTION)

>(CARBON ADSORPTION) \V\\

RAY-1A. B• Mif-iai

f v ' i 111 17NEC TREATMENT SYSTEM(CARBON ADSORPTION)

LEGEND;

SOURCE CO'NTROL RECOVERY WELL

DREO-M MEW REG|ONAL RECOVERY WELL

• TREATMENT SYSTEM

SLURRY WALL

RECOVERY PIPING FOR RECBMAL WELLS

FORMER BUILDING FOOTPRINTS

DATE

ISSUED FOR REPORT

ISSUE / REVISION CK*D BY AP'D BY

LOCATION OF RRWs, SCRWs, AND

GROUNDWATER TREATMENT SYSTEMS



PREPARED FOR

MEW COMPANIES


200 400 FEET

ONIMNONO. 23-016-E30

FIGURE 4-1K.\25-01t\E30£WG 31 JULY 03

STEVENS CREEK OUTFALL CONSTRUCTION DETAILS -SEE DWG. NO S7-1BS-E72

,000

-PIPELINE-(JPIPELINE-(E

EAI-3A

EAJ-2

-V

•V

LEGEND:

CONVEYANCE PIPINS

O REUSE VAULT

D SSS-SA REGIONAL RECOVERY WELL

EAl-2*• SOURCE CONTROL RECOVERY WEIL

1. DETAIL PLAN AND ELEVATION VIEWS FOR THE GROUND WATERCONVEYANCE PIPELINES ARE SHOWN ON THE FOLLOWING DRAWINGS:

-V

PIPELINE

•A"•B-•c-VT•FI"VV, -HV

DRAWING NOUBERS

87-185-E62, E7897-1B5-E65, E21, E7897-185-E63, E6487-18S-E68, E6+97-185-E64, E66, EBO. E81. ES2, £8387-185-E8497-185-E7797-1B5-E7897-18S-E120

ao*

-V

Jr6'yftf,000

•V

No. DATE

ESUEO F0« BETOBI

ISSUE / REVISION

REGIONAL RECOVERY WELLS, CONVEYANCE PIPELINES

AND TREATMENT SYSTEM LOCATION

REGIONAL GROUND WATER REMEDIATION PROGRAM

NORTH OF U.S. HIGHWAY 101MOUNTAIN VIEW, CALIFORNIA

PREPARED FOR

INTEL CORPORATION AND

RAYTHEON COMPANY

Locus DRAMNO NO. 97-185-E99

FIGURE 4-2

DORCHESTER DRIVE

3 MUES IK.

-V ii

aT

Si

LAMBERT WAY

HH/SMAN ROAD

I ,5: '

I' § •

LEGEND:

RAYTHEON COMPANY

INTEL CORPORATION

FAIRCHILD SEMICONDUCTOR CORPORATION

NEC ELECTRONICS. INC.

SUMITOMO MITSUBISHI SILICON CORPORATION/VISHAY GENERAL SEMICONDUCTOR, INC.

SMI HOLDING LLC

AREAS OF EXCAVATION

AREA REMEDIATED BYSOIL VAPOR EXTRACTION

NOTES:

1. NO SOIL REMEDIATION WAS PERFORMED FOR THEREGIONAL PROGRAM NORTH OF U.S. HIGHWAY 101.

DATE

ISSUED FOR REPOOT

ISSUE / REVISION CK'D sr

LOCATION OF SOIL CLEANUP ACTIVITIESMEW FACILITIES

SOUTH OF U.S. HIGHWAY 101MOUNTAIN VIEW, CALIFORNIA

PREPARED FOR

MEW COMPANIES


100 320 FEET

25-007-E4FIGURE 4-3

K:\23-OOAEUWG 1 APR 03

***•

DATE

ISSUED FOR REPORT

ISSUE/ REVISION CK'D BY

\

LEGEND:

•

(P)

0)

(o)

APPROXIMATE PRIVATE WELL LOCATIONS

PRIVATE WELL LOCATION SUSPECTED FROMAERIAL PHOTOGRAPHY REVIEW

AGRICULTURAL (IRRIGATION) PRIVATE WELLPERFORATIONS BaOW -B-C' AQOjTARD

DOMESTIC PRIVATE WELLPERFORATIONS ABOVE "B-C" AQUITARD ONLY

PRIVATE WELL-UNKNOWN PERFORATIONINTERVALS

(S) INDICATES SEALED WELL

(MV-1B) CITY WATER SUPPLY WELL-PERFORATIONS"B-C" AQUITARD

WELL INVENTORY STUDY BOUNDARY

STUDY AND REMEDIATION BOUNDARY (SAR)BASED ON APPROXIMATE LIMIT OF AREAWITHIN 5 PPB TCE ISOCON, 200 PPB TCAISOCON, OR MCL AND/OR STATE ACTION LEVELFOR OTHER CHEMICALS IN ANY AQUIFER

1. WELL LOCATIONS SHOWN ON THIS MAP AREAPPROXIMATE, AND ARE INTENDED FORILLUSTRATIVE PURPOSES ONLY.

POTENTIAL CONDUIT LOCATIONS


PREPARED FOR



coma NO. 23-007-E56

FIGURE 4-4K:\23-QOAE5S-0WG 24 KOV 03

'.&T . ;

iEQEMQiv

¥>

I14SA.

I

14SA

MONITORING WELL NUMBER

REGIONAL RECOVERY WELL

SOURCE CONTROL RECOVERY WELL

SLURRY WALL

14*.

1

C1W—., .CM

.*"«

A** LA«

'""Aa.000 Si^ .RHIA »MA*£

BA. .71A*70A

.161A 12A*1

-HI*;

V J M P K «

>B4A

RW-2M.148AISM. - • *23A

1S7A,,150A

.RW-16A

,133A

:i*s8A-

C:Eg

R14A

RM.

SOPZ-'« aEW-2«

SOPZ-2*

so-1 A .R44A

• ME1A

RE8A.RE11A-

KE2&?

A«« H»

A'S»

R72A. .R71A

.RE5AA RE7A,

ItQIA*

RE9A- R70A*REIOA" R^JA.

• R74A.RMA*1","

.24A

.105A

R27A SLIA'«RAY-1A. "». *"3I

•10W A SI&J,R55A

.10M

R52A

2BA

,15SA

O.US RCAO

.... 'W3-UM-U'51A» ARW-2SA

1S2A.

REB-MW-tA ,147A

•'"* AC5F1A

S«-ia

SUM'

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-138A

L,,• "^^SlW. .SLm

.45A

' REC-1M B

Ci^s.

XIru

fe

I

JU4-1

5:is

DRAWINGNO. 97-18J-E614

FOR AREA NORTH OF 101.wa-3

n>.WT57-1*

,11>A

W14-10. ERM-3

NEC23A NEC27AENEC7A- • A -HEC-PZ-tA

.NECW

MEC28A

7-

%

R43A. 'ti

ENLARGED "A/A1" AQUIFER

BASEMAP


PREPARED FOR


HHHi^VH^ ^W^ ^V^^^^ff^^l^ DRAWING NO. 97-183-E613

FIGURE 4-5

K.\97-183\E«130WG * NOV 03

»«

.K.MKWUKWWW

MONITORING WELL

REGWHAL RECOVERY WELL

. _ ,SLURRY WALL

"A/A1" AQUIFERBASEMAP


PREPARED FOR


DRAWING NO. 87-183-E614

FIGURE 4-6

K;\97-18AE6".OWO 4 HOV 03

« ^^^^

^J*£f^^^^

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t-

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%%

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O^65**

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^ x 1 P M SB-B ««£>• «ow Ifeo a?^*"'* |«»2'>*M* '1^<W5r~~~r*al,& f"3"1 1 Ira- i) ' -» ,1_*-'t»-* — "r^J-'ni>-'V .WK^ -^* j>85 ^ 12Bv i. \. *S W^W^1»" *^ ^ S. J* w!T-i'.-8

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f4*l » i,9«f1 / * ""

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R1»t |- *

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I " *7"4' «Myj Wlt-S, *

0«-1 X «1. .W-"

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1%

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\< • .W5-.% -7

%

| %* %tt *

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LEGEND;

•79B1 MONITORING WELL

n"*"'i"> REGIONAL RECOVERY WELL

A"WW SOURCE CONTROL RECOVERY WELL

+"*"1"™ OTHER RECOVERY WELLS

ti*1J*" '-1 SLURRY WALL

1

ym~tD

t'*V^*' 4•*"* 35

1 i *-000

»»-ti^H

«-7.

.TO-lt

-loOtf11HP-I3 E "Z^Zl

t>^

, ^9*

ggjJOO0

•3-11..W-13

*t

Tt.

\%B.W-M|

"B1/A2" AQUIFER

^ BASEMAP


PREPARED FOR


SCALE

• ESH^ SiBlM^• l k^^H H^M 500 0 500 1000 FEET

IjHMF^FvOQI DRAWING NO. 97-183-E615

FIGURE 4-7

K\S7-183\£«150WC 4 NOV 03

s*B

\

\

"US*

IT. ' ' IOB2-1

.—.- mse/s* «w.!JB2)'—, : i!»iY-2tB2) *(Bf-3(B2) *|

«"* | .1782 ^

0

#"

KS85S2

- ''• • 432B2 »-:

MONITORING WELL NUMBER


SOURCE CONTROL RECOVERY WELL

SLURRY WALL

. ' •!&' W4-13

,W3-H W3-15.

"B2" AQUIFER

BASEMAP


PREPARED FOR


Locus DRAWING NO. 97-183-E616

FIGURE 4-8

K:\97-183\E616.0WC 4 NOV 03

-V

-r

-V \

T\

-55B3 *

-V

•31B3

.3993

.R5SB3 S' B3733

R31B3. ,

!R18B3

.R27BI

133B3*

r28B3-

•r

>-v

iESEMQ;MONITORING WELL NUMBER


"BS* AQUIFERBASEMAP


PREPARED FOR


Locus NO. 97-183-E8t7

FIGURE 4-9

K\97-183\E6170WG 4 NOV 03

•R4C

R3C

DW1-230")DW1-360 I JDW1-420 ("•DW1-500J

8.00°Q

! S

8

fDW2-2J+._J DW2-285

™"j DW2-3J7LDW2-452

10C.

.1C

R1C.

SO. RW-1C/DW7-302CDW7-«I5C

DW4-270ai)0»«-217

DW3-219

.110

DW3-3B4DW3-505DW3-5C-

65B3"

~'/'i

p , -»

0.00°

<s

I

Iis

DW6-231• DW6-304

DW6-470DW6-496

60.

fDWS-209Jms-310aJ

,8l,<• \OMS-na

i!QT

1

LEGEND:

.90MONITORING WELL

BDW3-219 REG|ONA1_ RECOVERY WELL

O"*"10 SILVA RECOVERY WELL

O70 SEALED WELL

*C" AND DEEP AQUIFER MONITORING WELLS

BASEMAP


PREPARED FOR


Locus DRAWING NO. 97-183-E818

FIGURE 4-10

K\97-I83\E610.DWO 4 NOV 03

\

SC ST C7

I

KZ» •- ,'•

*"^

XEI3K «"17*REHA

_R«A R42A

"• SUM*

SIM*

.000fLi'S P048

aeS

x~s£:i

V\

I

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LEGEND:

•*°* ABANDONED OR SEALED WEILS

NOTES:1 WELL LOCATIONS SHOWN ON THIS MAP ARE

APPROXIMATE, AND ARE INTENDED FORILLUSTRATTVE PURPOSES ONLY.

ENLARGED "A/A1" AQUIFER

ABANDONED WELLS


PREPARED FOR



23-007-E50

FIGURE 4-11K.\23-007\E50»IO 84 HOV CU

\

\

\

SEE ENLARGEDrjSJ)jtAWING NO. 23-007-E50

FOR DETAILS SOUTH OF HWY 101

' \% %

\

10

\

,**<* xf-

\

.W2-1A

LEGEND:

•W1~2A ABANDONED OR SEALED WELLS

| j SLURRY WALL

NOTES:

1. WELL LOCATIONS SHOWN ON THIS MAP AREAPPROXIMATE, AND ARE INTENDED FORILLUSTRATIVE PURPOSES ONLY

"A/A1" AQUIFER

ABANDONED WELLS


PREPARED FOR


A

No. DATE

ESUED FOR REPORT

ISSUE/ REVISION

vzc

am BY oca BY AJ=0 Sf


SCALE

SCO 0 500 1000 FEH

KWMNS HO. 23-007-E49

FIGURE 4-1 2K.V3-OOAEW.OW8 24 »W 03

\

\

\

•v

\

\

,R1»»1

V*EL Is -'$ •• '?. !-h*Rdm ; I i I ; . t j ru«; v,' ;^lasm Sj, >J ' - : ?._; < pj," S: ^ -1 "Ran * % ; ^~~ - f'T" "r "pii J:' 11 ; .

'

In: , " . ' -••'* ili-4 i I - ": -'-

NE012B1 *.; ,,Vri3B1

Si

I

N"»^ I.

\

LEGEND;

«1MB1 ABANIDONED OR SEALED WELLS

| 1 SLURRY WALL

NOTES:

1. WELL LOCATIONS SHOWN ON THIS MAP AREAPPROXIMATE, AND ARE INTENDED FORILLUSTRATIVE PURPOSES ONLY.

" Bl" AQUIFER

ABANDONED WELLS


PREPARED FOR


A

No. DATE

ISSUED FOR REPORT

ISSUE / REVISION

vzc

Dm BY afo BY WO BY


SCli£

000 0 000 1000 FEET

DWWMQ no. 23— 007— E51

FIGURE 4-1 3K:\23-C07\E51.mX; 24 NOV 03

\

*

\

tT

\

^ j

f/ s

/

\

**""

^'», V'

/ \

LEGEND:

i5282 ABANDONED OR SEALED WELLS

| 1 SLURRY WALL

NOTES:

1 WELL LOCATIONS SHOWN ON THIS MAP AREAPPROXIMATE, AND ARE INTENDED FORILLUSTRATIVE PURPOSES ONLY.

"B2" AQUIFER

ABANDONED WELLS


PREPARED FOR


A

No. DATE

ISSUED FOR REPORT

ISSUE/ REVISION

vzc

DtVN. BY CK'D BY AP'O BY


SOLE

HX 0 900 1000 FEET

DWWrNO HO. 23-007— E53

FIGURE 4-1 4K.\23-MAES3.Dtre 2+ KOV 03

\\

\\ LEGEND:

ABANDONED OR SEALED WELLS

v. •- rfff<** t

IffNOTES:1 WELL LOCATIONS SHOWN ON THIS MAP ARE

APPROXIMATE, AND ARE INTENDED FORILLUSTRATIVE PURPOSES ONLY

\

\

* ''

1*f ~ — R14B31

I

-„, ..RI1W - _til*1 ME1C1H'«27aj pi ,

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r ^ M ^ i f 1 ^ ^ > / \xL t ll1-, ,- ' ^ )r -^ 1 |-k .^^fi^ " >£_ ;-- - 7

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«?«" ^st, ^

* i \/ y *f * * "B3" AQUIFER

*** ** ABANDONED WELLS


PREPARED FOR


SWJ-

l_(f\_f^l|C "° ° »0 1000 FEET

A ^^ m"mn vzc fcW%rWI5^ DRW.WHO. 23-007-E54

No. DATE ISSUE / REWSTON OWN BY CK*D BY APD or FIGURE 4-15

K.\23-007\EMD*C 24 MOV 03

\

***

\

f*4

[r - X V*

Dwr-seo)DW1-420>-«DW1-50oJ

i. ««; -5-

/ 1

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"3

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t<*

•*<*,IfK

*

,«**

LEGEND:

.K ABANDONED OR SEALED WELLS

NOTES:

1 WELL LOCATIONS SHOWN ON THIS MAP AREAPPROXIMATE, AND ARE INTENDED FORILLUSTRATIVE PURPOSES ONLY

" C" AQUIFERABANDONED WELLS


PREPARED FOR


A

No. DATE

ISSUED FDR REPORT

ISSUE / REVISION

vzc

DUN. BY art BY WO BY

LocusT E C H N O L O 6 I E S

SCAl£

500 0 500 1000 FEET

mma NO. 23-007-E55

FIGURE 4-1 6K \23-OOAES5JJWS 2« NOV 03

I

APPENDIX AHYDROGRAPHS AND HISTORICAL WATER

ELEVATION MEASUREMENTS

PROVIDED IN ELECTRONICFORMAT

APPENDIX BHISTORICAL WATER QUALITY

MEASUREMENTS

APPENDIX CHISTORICAL WATER ELEVATION AND

CAPTURE ZONE MAPS

APPENDIX DDIRECTION OF VERTICAL GRADIENTS ACROSS

AQUITARDS

APPENDIX EHISTORICAL TCE CONTOUR MAPS

APPENDIX FTCE DISSOLVED MASS CALCULATIONS

APPENDIX GLIST OF ARARS

APPENDIX G

ATTAINMENT OF ARARS AND PERMITTING REQUIREMENTS

Section XVI of the CD requires that:

All actions required to be taken pursuant to this Consent Decree shall beundertaken in accordance with the requirements of all applicable federal, state andlocal laws, regulations, appendices to this Consent Decree, and permittingrequired by CERCLA and the CD.

ARARs associated with the MEW Site have been categorized into three types:

Ambient or chemical-specificPerformance, design, or action-specificLocation-specific

Ambient or chemical-specific requirements set health or risk-based concentration limits forparticular chemicals. Performance, design, or action-specific requirements govern particularactivities, such as the Clean Water Act pretreatment standards for discharges to publicly ownedtreatment works. Location-specific requirements refer to facility citing restrictions.

Section VI.G of the CD states that:

Pursuant to CERCLA Section 121(e), 42 U.S.C §9621(e), no federal, state, orlocal permit shall be necessary for the portion of the Work conducted entirely onsite where such Work is carried out in compliance with said Section.

Not withstanding this provision, however, the Companies intend to apply and obtain all permitsthat would otherwise be required. The following sections describe the ARARs of local, state, andfederal regulatory agencies that the remedial work will be designed to achieve.

1 CHEMICAL-SPECIFIC ARARs AND CLEAN-UP STANDARDS

Chemical-specific ARARs for the MEW Site include federal and State of California drinkingwater standards. The ROD includes federal MCLs, as defined under the Safe Drinking Water, asARARs for ground water at the MEW Site. Ground water clean-up standards are defined in theCD as 0.005 mg/1 TCE for the shallow aquifers and 0.0008 mg/1 TCE for the deep aquifers. TheCD also provides that the clean-up of the other 10 organic chemicals based on clean-up of TCEwill meet ARARs and will not exceed maximum cumulative risk levels for the ground water.

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2 ACTION-SPECIFIC ARARs

Action-specific ARARs for the MEW Site depend on the type of remedial alternative chosen toobtain prescribed clean-up goals. As specified in the MEW ROD, soil remediation can beachieved by means of partial excavation and/or in-situ vapor extraction and ground waterremediation can be accomplished through ground water extraction and treatment. The ROD alsospecified that treatment of extracted ground water and soil vapor be performed by the removal ofVOCs from either matrix by air stripping and/or GAC adsorption. The use of either air strippingor GAC adsorption triggers ARARs for VOC emissions, carbon regeneration or disposal, anddischarge or reinjection of treated effluent.

2.1 Air Emission Standards

The MEW ROD states that, although on-site facilities are exempted by CERCLA from theBAAQMD administrative requirement to obtain a permit, emission limits and monitoringrequirements imposed by the BAAQMD must be met. These emission limits apply to thedischarge of air from treatment systems (i.e., air stripping towers) or of GAC-treated soil vaporfrom an in-situ aeration system.

Two ground water treatment systems are currently in place for the MEW Regional system. TheSouth of 101 groundwater treatment system is located at 644 National Avenue. This systemconsists of a series of groundwater extraction wells, groundwater filters, a surge tank (air strippersump) and three 10,000-pound aqueous carbon adsorbers. The North of 101 groundwatertreatment system is located at Westcoat Road at Moffett Field. The system consists of a series ofgroundwater extraction wells, groundwater filters, two air strippers with two 4,000-pound vaporcarbon off-gas adsorbers on the primary air stripper.

The South of 101 groundwater treatment system does not have any air emissions and thereforedoes not require a BAAQMD Permit. The North of 101 groundwater treatment system does haveair emissions and therefore does have a BAAQMD Permit.Currently, the BAAQMD, under its Regulation 8, Rule 47, currently limits treatment systems to adischarge up to one pound of total VOCs per day. The rule further specifies that when the totalVOC discharge from a treatment system exceeds the prescribed emission limit; the use of the bestavailable control technology (BACT) will be required. Technologies such as carbon adsorptionor ultra-violet oxidation are considered by the BAAQMD to be BACT. The use of BACTtriggers other BAAQMD requirements that would govern the operation and monitoring of theBACT system employed.

To document compliance with applicable air quality regulations, the MEW companies obtainedan "Authority to Construct" and a "Permit to Operate" from the BAAQMD, under itsRegulation 8, Rule 47 requirements, for the proposed MEW N of 101 ground water treatmentsystem. The BAAQMD requires the performance of a risk assessment to determine theoreticalcancer risks and non-cancer adverse health effects of the proposed project whenever a new source

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of toxic emissions is proposed. A risk assessment was completed for the MEW N of 101treatment system and the BAAQMD determined the emission limits and monitoring requirementsfor a proposed treatment system based on the results of the risk assessment performed.

The following subsections discuss subparts from the Code of Federal Regulations, Title 40, Part61 that were included hi the evaluation of the design process.

2.1.1 National Emission Standards for Mercury

The Code of Federal Regulations, Title 40, Part 61, Subpart E (40 CFR 61.E) specifies thenational emission standards for mercury that "are applicable to stationary sources which processmercury ore to recover mercury, use mercury chlor-alkali cells to produce chlorine gas and alkalimetal hydroxide, and incinerate or dry wastewater treatment plant sludge." The remedial actionsimplemented at the MEW facilities do not involve any of the process discussed above. Therefore,this subpart was not applicable to the design of the RGRP systems.

2.1.2 National Emission Standards for Benzene

The Code of Federal Regulations, Title 40, Part 61, Subpart FF (40 CFR 61.FF) specifies thenational emission standards for benzene waste operations that "apply to owners and operators ofchemical manufacturing plants, coke by-product recovery plants, and petroleum refineries. Theprovisions of the subpart also apply to hazardous waste treatment, storage, and disposal facilitiesthat treat, store, or dispose of hazardous waste generated by any facility discussed above. Thewaste streams at hazardous waste treatment, storage, and disposal facilities subject to theprovisions of this subpart are the benzene-containing hazardous waste from any facility discussedabove."

However, Subpart FF also identifies the following waste that is exempt from its requirements,such as "(1) waste in the form of gases or vapors that is emitted from process fluids, (2) waste thatis contained in a segregated storm water sewer system, and (3) waste that is not discharged fromthe process unit which generates the waste stream and, instead, is returned directly to theprocess."

The remedial actions implemented at the MEW facilities do not involve any of the processdiscussed above and therefore, this subpart was not applicable.

2.1.3 National Emission Standards for Vinyl Chloride

The Code of Federal Regulations, Title 40, Part 61, Subpart F (40 CFR 61.F) specifies thenational emission standards for plants that produce vinyl chloride by any process.

Although the provisions of this subpart pertain to system processes more sophisticated than theground water treatment system proposed, it was considered in the design evaluations. As

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discussed in the previous section, the BAAQMD determines the emission limits and monitoringrequirements for a proposed treatment system based on the results of the risk assessmentperformed. The emission limits and monitoring requirements were specified in the "Authority toConstruct" and "Permit to Operate" for the MEW N of 101 treatment system.

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2.2 Carbon Adsorption

Aqueous GAC adsorption units are being used for treatment of extracted ground water at theMEW S of 101 facility. Vapor phase GAC adsorption units are being used at the MEW N of 101facility. All spent carbon is subject to ARARs applicable to its disposal or regeneration. Undercurrent regulations, spent carbon generated from the treatment of a hazardous waste or that meetsthe criteria for a hazardous waste is considered to be a hazardous waste under the ResourceConservation and Recovery Act (RCRA) and is required to be handled as a hazardous waste.

Spent carbon generated from the treatment systems at the MEW sites are regenerated off-site at alicensed facility. Therefore, management of the spent carbon must comply with certainrequirements under RCRA and California hazardous waste regulations for transportation, storage,and generation of hazardous waste for recycling. If the spent carbon were to be disposed off-siteas a hazardous waste, it would need to be treated to meet Best Demonstrated AvailableTechnology treatment standards and would be subject to RCRA's Subtitle C off-site land disposalrestrictions.

There were no requirements identified from the local municipal and county hazardous materialsordinances for the storage or monitoring of spent carbon on-site. Once the carbon is determinedto be spent through sampling, it will be removed and transported off-site for regeneration.

2.3 Design and Operational Standards for Tank Systems

The California Code of Regulations, Title 22, Division 4.5, Chapter 14, Article 10 (22 CCR4.5,14,10), specifies standards and establishes design and operational requirements for storing,treating, and transferring hazardous waste using tank systems. The design and operationalstandards and requirements are regulated by the California Department of Health Services (DHS).The use of GAC contained in closed tanks for the treatment of VOCs requires tanks to havesufficient shell strength and pressure controls (e.g., vents) to prevent potential rupture or collapse.Minimum shell thickness is required to be maintained at all times to ensure sufficient shellstrength. Factors to be considered in establishing minimum shell thickness include the width,height and materials of tank construction, and the specific gravity of tank contents.

Secondary containment required for tank systems storing, treating, and transferring hazardouswaste to prevent its release or its constituents into the environment. Secondary containment fortanks shall include one or more of the following devices:

A liner (external to the tank)

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A vaultA double-walled tankAn equivalent device as approved by the DHS

Secondary containment systems shall be designed or operated to contain precipitation from a 24-hour, 25-year storm event plus the greater of 10 percent of the aggregate volume of all tanks or100 percent of the capacity of the largest tank within its boundary, whichever is greater.

2.4 Standards for Thermal Treatment of Hazardous Waste

The California Code of Regulations, Title 22, Division 4.5, Chapter 14, Article 15 (22 CCR4.5,14,15), specifies standards for the thermal treatment of hazardous waste that could beapplicable if thermal treatment is utilized for pre-treatment in the remedial design. Becausethermal treatment is not employed in the MEW remedial design, these standards are notapplicable.

2.5 Discharge to Surface Waters

The following sections describe the requirements that apply to the discharge of treated effluentinto surface waters or storm drains.

2.5.1 Water Quality Control Plan

The Water Quality Control Plan, San Francisco Bay Basin (Basin Plan) provides future directionof water quality control management for protection of California's waters. The Basin Planconsists of a definitive program of actions designed to preserve and enhance water quality, and toprotect beneficial uses for water basins. The Basin Plan establishes the necessary elements of awater quality control plan, including identified beneficial water uses, water quality objectives,implementation program for meeting these objectives, and a surveillance program to monitor theeffectiveness of the plan.

Treated water from the S of 101 MEW treatment system are discharged into the local storm sewersystem along Fairchild Drive. Treated water from the N of 101 treatment system are dischargedthrough a discharge force main at Moffett Field, into Stevens Creek. Because the chosenremedial alternative requires discharge to surface water, effluent limitations and monitoringrequirements apply for this point source discharge. The RWQCB has established the effluentdischarge limitations and permit requirements for the MEW ground water treatment system underseparate NPDES permits for the S of 101 and N of 101 systems.

2.5.2 State Board Resolution 68-16

RWQCB Resolution No. 68-16, "Statement of Policy with Respect to Maintaining High Qualityof Waters in California," requires the continued maintenance of existing water quality unless it is

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demonstrated that a change will benefit the people of the state, will not unreasonably affectpresent or potential uses, and will not result in water quality less than that prescribed by otherwater quality control plans or policies.

Discharges to surface water under the Clean Water Act must, at a minimum, meet BACTrequirements for toxic pollutants and Best Conventional Control Technology for conventionalpollutants. As discussed above, treated water from the MEW treatment systems discharge intothe local storm sewer systems under an NPDES permit. The RWQCB has established the effluentdischarge limitations and permit requirements for the MEW ground water treatment systemsusing either water quality standards prescribed in the Basin Plan or best available technologystandards.

2.5.3 National Pollutant Discharge Elimination System Program

Effluent limitations and monitoring requirements apply to the discharge of treated effluent intosurface waters or storm drains. The NPDES program, under the Clean Water Act, requires apermit before discharge of treated effluent from point sources to surface waters. The NPDESpermit specifies restrictions on quantities, discharge rates, and concentrations of pollutantsdischarged (i.e., effluent discharge limitations) and specifies sampling, monitoring, and reportingrequirements for a particular point source.

Currently, ground water treated at the S of 101 MEW treatment system are discharged throughthe City of Mountain View storm drain system to Stevens Creek under NPDES Permit No. CAG912003 issued by the RWQCB in October 1999, with a discharge limit of 100 gpm of treatedeffluent.

Currently, ground water treated at the N of 101 MEW treatment system are discharged through aforce main at Moffett Field to Stevens Creek under NPDES Permit No. CAG 912003 issued bythe RWQCB in October 1999, with a discharge limit of 200 gpm of treated effluent.

2.6 Discharge to the Sanitary Sewers

A permit to discharge ground water into the local sanitary sewer system may be obtained from theCity's Environmental Safety Division under various conditions. The S of 101 treated groundwateris presently discharged to the City of Mountain View storm drain system and therefore dischargeto the City of Mountain View sanitary sewer system was not required. The N of 101 treatedgroundwater is presently discharged through a force main at Moffett Field and therefore dischargeto a sanitary sewer system was not required.

2.7 Trench Excavation, Potential Soil Treatment by Aeration and Disposal

Trench excavation to install the ground water conveyance piping requires a permit from theIndustrial Relations Division of the California Occupational Safety and Health Administration

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(Cal-OSHA). An Annual Trench and Excavation Permit from Cal-OSHA is required.Additionally the permit requires notification of Cal-OSHA's local district office at 10-days priorto any scheduled excavation or trenching work.

Planned trenching activity that may uncover soils containing VOCs requires written notificationof the BAAQMD at least 5 days prior to the commencement of such excavation. The writtennotification shall include the following:

Names and addresses of persons performing and responsible for excavation

Location of site where excavation will occur

Scheduled starting date of excavation

Procedures to be employed for the excavation and soil aeration

Name, title, and authority of the state or local government representative who hasordered the excavation

If excavated soil or drill cuttings were to be treated on-site by aeration, substantive provisions ofBAAQMD regulations may apply. Under the BAAQMD's Regulation 8, Organic Compounds,Rule 40, Aeration of Contaminated Soil and Removal of Underground Storage Tanks, theaeration of material containing a volatile organic content of 50 mg/kg or greater is subject toregulation by the BAAQMD. Prior to the treatment of soil by aeration, the level of contaminationof the material will be determined by obtaining soil samples for laboratory analysis. If the soil isdetermined to contain VOCs at concentrations greater than or equal to 50 mg/kg, requirementsspecified under Regulation 8, Rule 40 of the BAAQMD will be observed. The BAAQMD alsorequires written notification no less than 24 hours prior to the aeration of soils containing VOCs.The written notice shall include the following:

Estimated total quantity of soil to be aerated

Estimated quantity of soil to be aerated per day

Estimated average degree of contamination, or total organic content of soil

Chemical composition of organic compounds (i.e., TCE, etc.)

A description of the basis on which these estimates were derived (soil analysis testreports, etc.)

Although it is not expected the BAAQMD limit of 50 mg/kg will be exceeded, writtennotifications for soil and trench excavation, and soil aeration will be submitted to the BAAQMD

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five days prior to such work. The soil and trench excavation, and soil aeration will be monitoredand sampled. Excavated material will be stockpiled and treated by aeration, if necessary.

The treatment of excavated soil determined to contain VOC concentrations above the soilclean-up standards specified in the ROD and CD will be the responsibility of the property ownerwhere the contaminated soil was excavated. The responsibility for soil treatment will bedetermined by the location of the soils containing VOCs through the soil monitoring programspecified.

hi accordance with RCRA Subtitle C, soil containing listed hazardous wastes is considered toconstitute hazardous waste. Soil containing detectable amounts of TCE is considered a listedwaste and is governed by RCRA land disposal restrictions. RCRA land disposal requirementswould apply to soil or drill cuttings containing detectable concentrations of VOCs to be disposedoff-site. U.S. Department of Transportation requirements would also apply. However, it is notanticipated that any hazardous solid waste will be generated from the proposed remedial activitiesbecause soils which contain chemicals will be treated on-site by aeration and will be used asbackfill material, as appropriate.

2.8 Health and Safety Plan

A Site Safety Plan will be prepared prior to and for all remedial fieldwork to be performed at theMEW Site. The Site Safety Plan will be prepared in accordance with the July 1988 U.S.Occupational Safety and Health Administration's (OSHA's) 29 CFR 1910 and 1926, the U.S.Department of Health and Human Services "Occupational Safety and Health Guidance forHazardous Waste Site Activities (October 1985); and EPA's "Standard Operating Safety Guides."The Site Safety Plan will establish guidelines to protect on-site personnel, visitors, and the publicfrom physical harm and exposure to hazardous materials or wastes that may be encounteredduring the performance of field remedial work at the MEW Site.

The Site Safety Plan was included as part of the Construction O&M Plan, and the O&M Plan.

3 LOCATION-SPECIFIC ARARs

3.1 Fault Zone

The MEW Site is not located within 200 feet of a geological fault. Therefore, the fault zonerequirement of 40 CFR 264 is satisfied.

3.2 Floodplain

A hazardous waste treatment facility located in a 100-year floodplain must be designed,constructed, operated, and maintained to prevent washout of any hazardous waste by a 100-yearflood. The MEW Site is not located in a floodplain so these requirements are not ARARs.

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4 MISCELLANEOUS ARARs

4.1 Construction of Ground Water Extraction Wells

The ROD does not specifically identify ARARs for the installation of ground water extractionwells. The SCVWD standards for well installation and destruction will be followed.

4.2 Proposition 65

The notice requirement specified in California's Proposition 65 may also apply to the performanceof remedial activities. If listed chemicals are released in concentrations that would present asignificant risk, Proposition 65 requires that clear and reasonable warning be given to anyone whomay be exposed to the chemicals.

4.3 Building Permits

The City's Public Works and Building Departments will be notified of construction work that willbe performed within the City's jurisdiction, after EPA approval of the Final Design, and prior tothe start of work. The construction of all temporary or permanent structures (e.g., treatmentsystem) will comply with all applicable building codes and requirements of the City, hi addition,the City's Planning Division has requirements regarding architectural aesthetics and visibilitylimitations that may apply to treatment equipment and its enclosures.

The City has requirements for the installation of utilities in their right-of-way. These utilitiesinclude monitoring and extraction wells, ground water conveyance piping, electrical power linesand meters, ground water discharge lines, and connections to the sanitary and storm sewersystems. The following describes the permits generally required by the City for the installation ofutilities and identify the various departments that will be involved in the review and issuance ofpermits.

An Excavation Permit must be obtained from the City's Public Works Department for theinstallation of utilities within the City's right-of-way specific to each (general street) locationwhere work is to be performed.

An Encroachment Agreement will also be obtained from the City's Public Works Department.The encroachment permit is valid for a period of five years. At or just before the end of thisfive-year period, an extension may be requested and the City may re-evaluate the permitconditions.

Completed permit application packages for obtaining an excavation, well installation, andencroachment permits will be submitted to the City's Public Works Department after the FinalDesign has been approved by EPA.

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4.4 Utility Services

Appropriate agencies or companies will be contacted before installation of a particular utilityrequired for the remedial work. Permits and service contracts will be obtained in this process, asnecessary. Notifications will be provided as necessary.

4.5 Access and Easements

Property access and easements have been obtained from private property owners, from theCity of Mountain View, and from NASA Ames as necessary to construct and maintain theMEW systems.

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