SFUND RECORDS CTR

2201-00111

i SFUND RECORDS CTR

94453

SFUND RECORDS CTR

88151613

AR0105

SOLA OPTICAL SUPERFUND SITE

RECORD OF DECISION

U.S. EPA
Hazardous Waste Management Division

Concurrence

Sola Optical site

Record of Decision

-2 7~

son, Director

Waste Management Division

Date
Concurrences

Sola Optical Site

Record of Decision

David Hdwekamp,Dirfqtor Date

Air and Toxics Divis

Nora McGee Date

Assistant Regional Administrator

Office of Policy and Management

Nancy Marvel, Regional Counsel Date

Office of Regional Counsel

Harry Seraydarian, Director Date

Water Management Division
Concurrences

Sola Optical Site

Record of Decision

David Howekamp, Director Date

Air and Toxics Division

7--Z.5-?/

Nora McGee Date

Assistant Regional Administrator

Office of Policy and Management

Nancy Marvel, Regional Counsel Date

Office of Regional Counsel

Harry Seraydarian, Director Date

Water Management Division
Concurrences

Sola Optical Site

Record of Decision

David Howekamp, Director Date

Air and Toxics Division

Nora McGee Date

Assistant Regional Administrator

Office of Policy and Management

Nancy Megrvea, Regional Counsel Da

Office of Regional Counsel

Harry Seraydarian, Director Date

Water Management Division
Concurrences

Sola Optical Site

Record of Decision

David Howekamp, Director Date

Air and Toxics Division

Nora McGee Date

Assistant Regional Administrator

Office of Policy and Management

Nancy Marvel, Regional Counsel Date

Office of Regional Counsel

_

SEP 2 4 1991

Harry Seraydarian, Director Date

ater Management Division
TABLE OF CONTENTS

Page

List of Figures ii

List of Tables ii

Declaration for the Record of Decision 1

Decision Summary 3

I. Site Name, Location and Description 3

II. Site History and Enforcement Activities 5

III. Highlights of Community Involvement 6

IV. Scope and Role of the Response Action 6

V. Summary of Site Characteristics 7

VI. Summary of Site Risks 12

VII. Description of Alternatives 16

VIII. Summary of Comparative Analysis of Alternatives 19

IX. Selected Remedy 25

X. Statutory Determinations 26

ATTACHMENT A: Administrative Record File Index

ATTACHMENT B: Responsiveness Summary
LIST OF FIGURES

Page

Figure #1 Site and Vicinity Map 4

Figure #2 Chemical Concentrations Detected in Soil-Gas Samples -

April 1990 8

Figure #3 Site Plan 10

Figure #4 VOC-Contaminated Groundwater by Depth, with Shallow Capture

Line - April 1990 11

LIST OF TABLES

Page

Table A Chemicals of Concern 13

Table B Exposure Assumptions used in Future-Use Scenarios 14

Table C Risk Characterization — Air Pathway 15

Table D Risk Characterization -- Groundwater Pathway 15

Table E Primary VOCs in Groundwater and Clean-up Standards 16

11
Declaration for the Record of Decision

SITE NAME AND LOCATION

Sola Optical USA, Inc.

1500 Cader Lane

P.O. Box 6002

Petaluma, CA 94953-6002

STATEMENT OF BASIS AND PURPOSE

This decision document presents the remedial action selected for the Sola Optical USA (Sola) site in

Petaluma, California. This remedial action was chosen in accordance with the Comprehensive Environmental Response Compensation and Liability Act (CERCLA), as amended by the Superfund Amendments and Reauthorization Act (SARA), and, to the extent practicable, with the National Oil and

Hazardous Substances Pollution Contingency Plan (NCP). This is the first and final remedy and there

are no additional operable units.

This decision is based on the administrative record for this site. The attached Administrative Record

Index (Attachment A) identifies the documents upon which the decision is based.

The State of California concurs with the selected remedy.

ASSESSMENT OF THE SITE

Sola discovered solvents in the groundwater and in the soils adjacent to their underground storage tanks.

Sola removed the underground tanks and the adjacent soils. Sola has constructed and is presently

operating a groundwater extraction and treatment system. However, residual groundwater contamination requires that additional work, as actual or threatened releases of hazardous substances from this site,

if not addressed by implementing the response action selected in this Record of Decision (ROD), may

present an imminent and substantial endangerment to public health, welfare, or the environment.

DESCRIPTION OF THE REMEDY

The selected remedy for contaminated groundwater at the Sola site consists of:

groundwater monitoring to demonstrate capture of the contaminant plume and

ultimately, achievement of the cleanup standard;

operation of existing extraction well system;

construction and operation of two additional extraction wells and piping; and

conversion of two deep monitoring wells to extraction wells.
By fully addressing the groundwater contamination at the site, the remedy would reduce the principal

risk from the site. Sola addressed the principal threats posed by the site when they removed the

underground tanks and the contaminated soils adjacent to the tanks. These interim actions, conducted

prior to EPA involvement, were not inconsistent with the final remedy chosen by EPA.

Implementation of this remedy will increase the rate of groundwater cleanup in an area where the

groundwater contamination is highest. It will also address the low levels of contamination found in two

deeper on-site monitoring wells. This groundwater extraction system will operate until the cleanup

standards are achieved. Until these standards are achieved, evaluation of the remedy will continue at a

frequency to be determined during the remedial design.

STATUTORY DETERMINATIONS

The selected remedy is protective of human health and the environment, complies with Federal and State

requirements that are legally applicable or relevant and appropriate to the remedial action, and is costeffective. This remedy uses permanent solutions and alternative treatment technologies to the maximum

extent practicable and satisfies the statutory preference for remedies that employ treatment to reduce

toxicity, mobility, or volume as a principal element.

\JLKDaniel W/McGovern ^_ Date

Regional Administrator
Decision Summary

I. SITE NAME, LOCATION AND DESCRIPTION

SITE NAME AND LOCATION

The Sola site is located in southern Sonoma County, California, on the southeastern edge of the

City of Petaluma (See Figure 1). Sola has been manufacturing ophthalmic lenses since 1978 at its 35-

acre facility in Petaluma's industrial area. The facility address is 1500 Cader Lane and is located just

west of Lakeville Highway, south of the Lakeville Highway intersection with Route 101. The facility

comprises a manufacturing building and an adjoining administration office building. The former underground storage tanks were located behind the rear north corner of the manufacturing part of the facility.

Sola manufactures hard-resin ophthalmic lenses. The manufacturing process involves the

injection of a catalyzed, thermosetting resin into a cavity between polished glass molds. The mold

assembly is subsequently placed in an air oven to cure the resin. The assembly is removed from the oven,

the cured resin lenses removed from the assembly, and the assembly is put through a cleaning process

before production is repeated.

REGIONAL TOPOGRAPHY

The topography of the area, including the site itself, gently slopes at a rate of 50 feet per mile from

low hills in the east towards the Petaluma River, located about one mile southwest of the Sola building.

Adobe Creek is located 1,500 feet west of the Sola building. Adobe Creek intermittently flows in a

north-south direction.

HYDROGEOLOGY

Sola has conducted geologic investigations at the Site. Sola's investigations have revealed that

the depositional sequence of sediments below the surface at the site consists of a complex sequence of

interbedded clays, silts and sands, with lesser amounts of gravel. Shallow sediments represent a complex

sequence of alluvial deposits. At depths below the surface of approximately 80-100 feet, thicker clay

intervals were encountered which appear to be relatively continuous over distances of hundreds of feet.

Interbedded within these clay intervals are silt, sand, and gravel intervals of various thicknesses. These

deeper sediments probably represent complex depositional environments that involve both alluvial and

estuarine deposition. Groundwater in shallow sediments in the site vicinity is generally encountered at

elevations 9 to 12 feet below ground surface.

Groundwater flows in a south/southwest direction towards the Petaluma River, which is the most

likely point of discharge. Natural recharge occurs at the base of the foothills to the north/northeast.

Testing of the aquifer was conducted in October 1987 by Sola under the direction of the San Francisco

Regional Water Quality Control Board (SFRWQCB). This aquifer is unconfmed and has been classified

by EPA as a class IIA drinking water source aquifer.
\ v--:.;w4CT"> CASA GRANDE

PRATES A \

SOLA

FACILITY

figure 1 :

SfTE AND VICINITY PLAN

SOURCE: U.S. Geological Survey 7.5 minute

Petalum« River quadrangle,

photo revised I960.
LAND AND WATER USE

The facility is located in an area zoned for industrial uses. Adjacent property to the west is owned

by Stero Company, a manufacturer of dishwashers. There are residential subdivisions approximately

300 feet to the northwest and there is undeveloped land to the north. Fireman's Fund Insurance, the

RUSS Company, and Tegal Corporation occupy office space to the east of the Sola property. Property

to the south remains undeveloped and was formerly a private residence.

Two private wells operated previously in the vicinity of the Sola facility, the Stero industrial well

(approximately 1,000 feet west, downgradient of the facility) and the Crandell residential well

(approximately 1,500 feet southwest, downgradient of the facility). The owners of these two wells are

now supplied with water from the City of Petaluma. In addition, there is a City of Petaluma (Station #5)

municipal water supply well, located 300 feet north of the site and a city well on the Sola property that

has never been used. In 1988, Sola entered into a written agreement with the City of Petaluma. The

City agreed to discontinue use of Station #5 well to ensure that the operation of the municipal well does

not disrupt the ongoing groundwater clean-up operation by drawing down groundwater elevations in the

unconfmed aquifer below the screened intervals of the extraction wells.

Sola has sampled the Station #5 municipal well on 14 occasions between 1986 and 1989.

Analysis of these samples did not reveal the presence of any contaminants which exceeded the State or

Federal drinking water standards. Sola also sampled the Stero and Crandell wells six times each between

1987 and 1990 and the results did not exceed the State or Federal drinking water standards.

n. SITE HISTORY AND ENFORCEMENT ACTIVITIES

In May 1982, Sola identified low levels of solvents in groundwater under the Sola property near

six underground solvent storage tanks. Sola used these six 1,000 gallon underground tanks to store 1,1,1-

trichloroethane (1,1,1 TCA), acetone, and methanol. In 1985, Sola independently removed the underground tanks. The removal of the tanks reportedly included the excavation of gravel back-fill and an

additional three feet of native soil from the sides and bottom of the tank excavation. Sola collected 22

soil samples from the excavation pit. Based on the analysis of these soil samples, Sola excavated an

additional two feet from the eastern wall of the excavation pit. Additional samples taken following the

excavation indicated the presence of volatile organic compounds (VOCs); however, no additional

excavation was conducted.

Sola's early investigation also confirmed that groundwater at the site was contaminated with

VOCs,including 1,1,1-TCA, l,l-dichloroethene(l,l-DCE), l,l-dichloroethane(l,l-DCA),andmethylene chloride. EPA considers these compounds hazardous to human health and the environment.

In 1983, the SFRWQCB directed Sola to investigate the groundwater at the site. In 1987, the

SFRWQCB issued Sola a Cleanup Order #87-038 to construct a groundwater extraction and treatment

system. Sola was proposed for the National Priorities List (NPL) in June 1988. Sola began operating

its groundwater extraction and treatment system in August of that same year. Sola currently discharges

the treated groundwater to Adobe Creek under a National Pollution Dicharge Elimination System

(NPDES) permit from the SFRWQCB.
EPA conducted research to identify potentially responsible parties (PRPs), those parties who

may be liable pursuant to CERCLA, for the investigation and cleanup of contamination at the site. Sola

was the only PRP identified during this investigation. General and Special Notice was issued to Sola

prior to negotiations. Sola has financed and conducted a Remedial Investigation/Feasibility Study (RI/

FS) under an EPA administrative consent order (docket #89-22) signed in October 1989. Sola has paid

past costs and oversight costs incurred by EPA through June 1990.

The Remedial Investigation included sampling of soils, soil gas, and groundwater. The

Remedial Investigation Report, which summarized these activities, was submitted by Sola on December

3,1990. EPA completed the Risk Assessment in April 1991. The Feasibility Study was submitted by

Sola on June 10,1991.

HI. HIGHLIGHTS OF COMMUNITY INVOLVEMENT

The Community Relations Plan (CRP) was developed in-house by EPA's community relations

staff, following EPA guidance. Consistent with the recommendations of the CRP, the Project Manager

briefed the Petaluma City Council and issued a fact sheet announcing the administrative consent order

and the commencement of the RI/FS. The City Council meeting took place on October 19,1989. The

fact sheet was mailed to area residents during the same period and generated few inquiries.

In February 1991, following the completion of the remedial investigation, EPA issued another

fact sheet summarizing the findings to the public. No responses were received following distribution

of this fact sheet

The public participation requirements of CERCLA Sec. 113(k)(2)(B)(i-v) and 117 were met in

the remedy selection process. In June 1991 EPA issued the proposed plan. An announcement was

printed in the Santa Rosa Press Democrat on June 17,1991, announcing the public comment period and

the public meeting. EPA held the public meeting on June 25,1991, in the Veterans Memorial Building

in Petaluma. California Department of Health Services and four members of the community attended

the meeting. EPA received only one comment letter during the public comment period, which officially

closed on July 16,1991.

Details of community involvement activities and responses to public comments on the Proposed

Plan are presented in the Responsiveness Summary (Attachment B).

IV. SCOPE AND ROLE OF THE RESPONSE ACTION

Interim cleanup of the groundwater and the contaminated soil has occurred. Sola addressed the

principal threats by removing the underground tanks and contaminated soils adjacent to the tanks. The

residual extent and concentration oV contamination in the soils do not present a significant threat, based

on the results of the risk assessment and a groundwater model.
The actions conducted by Sola under the direction of the SFRWQCB have partially addressed

the risk from contaminated groundwater and have attempted to halt or reduce the spread of contaminated

groundwater but were not intended to be a final remedy. The selected final remedy addresses the

remaining risks posed by the contamination in groundwater. The remedy will eliminate the potential for

human exposure to contaminants through the ingestion and inhalation of contaminants in the groundwater.

The reduction of risk will be achieved by the hydraulic capture of contaminants in groundwater

through the use of groundwater extraction wells. The existing system will be enhanced with two new

shallow extraction wells and two deep extraction wells (converted from monitoring wells). Groundwater with contaminant concentrations above the State drinking water standards will be pumped into the

extraction system.

Extracted water will either be treated with the existing carbon filter system at the facility and

discharged off-site or discharged to the City sewage treatment system with or without treatment. The

City of Petaluma has an industrial discharge limit of 1 part per million (ppm) for total toxic organics.

Monitoring results from the extraction system indicate that concentrations in groundwater are presently

low enough to meet this standard without treatment.

There are no additional operable units, and no further action is warranted for soils.

V. SUMMARY OF SITE CHARACTERISTICS

SOIL CONTAMINATION

In July 1985, Sola independently removed six underground storage tanks. Sola contractors

reported that they observed no evidence of leakage during the tank removal, which indicated to them,

the release of contaminants could have been the result of accidental spillage.

The removal of the tanks included the excavation of back-fill material and approximately 3 feet

of soil from the sides and bottom of the tank excavation. Samples were taken from the pit after the

excavation. Analytical results for the samples collected from the excavation pits revealed the presence

of acetone, ranging in concentrations from 1.1 to 54 ppm. Concentrations of 1,1 DCE were detected at

10 parts per billion (ppb). An additional two feet of soil was excavated from the eastern wall of the pit

where the acetone was detected.

In July 1986, Sola independently conducted a soil gas investigation . Soil gas samples were

collected from 48 locations. The highest VOC concentration was 250 milligrams per liter of 1,1,1 -TCA.

In April 1990, EPA required Sola to collect and analyze samples of sub-surface soils and soil

gases. The soil gas survey included samples from 40 locations at depths ranging from 2 to 9 feet. The

results are presented in Figure 2. The lateral and vertical distribution of VOCs and the magnitude of

VOC concentrations detected in soil gas do not currently indicate the presence of a principal threat in

soil.
FIGURE #

\V

o

2:fl

0.003 TCA

O.OOOO8 PCE

O.O7 Acetone

LF-H

w TM

ir-n

OOOl PCE

OO8 Acetone

c

*Qj£J ' '"

onaoo •

e-n

oT~

6

1

OJ03

0008

OJ08

.

^

0

- ".;.

I.I-DCA

rCA

Ft 13

I.I-DCA

TCA

TCE

PCE

Acctonr

X

\,

— X881

c

1

E

J

SM

JSP TCA'

40itt BcK

''/ 2-rt

' / 0.4

/ , oaa ^

' / 00003 1

/ / otrr i

/ / / /

*VL.' •'.'•.'•.'-.' •

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fx:A

HCK

TK

Acetone

_,

C

^

seto

( —

* MANUFACTURING BUILDING

V////////////////////

2-ft

X^ R6THS"TCA

>^ OJDO Acetone

X

sc4

5 ft

f- 0.0006 TCA

Oj03 Acetone

•— Treatment

system area :

X^To^ Jcelone ^^1^,^

j-jt b^otidf' TCA 602 " -TCA T";W •'i^^^pw^.^^i

OuOB Acetone """^ Acetone / Ota Acetone " " -*ivii '•' •

^f / • ' .. OLO2 PI13 ;

^^ / T.ft i -y :'-: , 0.001 TCB

^^ / •&- j.j.rjcB 0.003 PCE -

^3 A,,! X^° 0* MW_ . / 0.1 A«tOne;

/<//<x'////// "PLWIATWH

' / S / S ^S f X Sn^-gas utmpfing lacfllbn

0 Ground-water monitoring

A EnncSon Ml beaten

y.v.--.- • •: ••<-..•

-a-ft. »Jt, Depth In teet

OJ008 a TCA

' Chemical compound

1.1-DCE - 1.1-Dichloraethene

TCA - Trichbroetnane

1.1-DCA • 1.1-Dichbreethane

PCE • Teltadilorwlhene

Fl 13 - Trichbroltilluoroethane

T Note:

0.00003 to 0.1 (}ig^).

Chemicals oataclad in iiiiUuiit

ojxm PCE

ooa .Acetone

00

air camples (jig/I).

n Acetone 0.2. 0.1

TCA 0.0002. 0.0001

4/3 Acetone 0.06, 0.08

PCE 0.0004, 0.00008

TCA 0.0002. 0.004

4/4 TCA 0.0002

PCE 0.00004

Acetone 0.06

4/5 TCA 0.0005

PCE 0.00004

TBB~~

OJDOOS

aoaad

OjOB

.I,1-OCA

TCA

PCE

Acctohe

Former underground

tanks location

vssr riis

TCA ..•';

oaoos TCB

0.0008 I"CE

OJCa Acetbrie

oat TCA

0X004 TCE

PCB.i

-ft"":"

-.— , tCA

oxuoae PCK

DM . Acetone

0.003 TCA

o.ooooe

O.OZ Acetone

oM" TCA

OJOOOOB PCE

OM Acetone

0 W-16

2ft V-ft

TCA

 : ."•••;

<OJ008 9B 1.1DCE"

<om a I.I-DCA

<OJOOM oat TCK

I.I-DCA

.TCA

Acetone

Si "".' 1,1-DCA

ai TCA

aaoa PCE

om ma

aoooa TCA,:

TCB

oaata PCE -^

0.1 Acetdri*:

0.4 f 113

0.01 TCA

O.OOJ TCE

O.O2 PCE

Acetone

X

s

""

tar ivsr~ i.i-ocA OJJI OuOOB TCA

at O.1 Acetone

4-ft

0.002 TCA

O.OOOO8 PCB

<a008 14 t.l-DCE

OB 9 , I.I-DCA

ao2 ; a TCA

<aooo4 0.0004 TCB

o.oooos o.ooa PCE

O.4 F113

O.S TCA

0.006 TCE

0.004 PCE

O.1 Acetone

o.e I.I.DCE

.... .

OOJ TCA

ojoooa res

OJOOO Acetone

0.03 0.03 I.I-DCA

O.OB 0.03 TCA

O.OO5 O.O04 TCE

ttOO3 0.001 PCE

' <aooi 0.04 Ft 13

CHEMICAL CONCENTRATIONS DETECTED IN

SOIL-GAS SAMPLES (ng/L), APRIL 1990
Sola collected soil samples from six soil borings near the former location of the storage tanks.

1,1-DCE was detected at a maximum concentration of Slppb.

EPA required Sola to use a contaminant transport model to determine whether the contaminated

soil would further contaminate the groundwater. The results of the model indicated these soils do not

pose a principal threat of further contaminating groundwater.

GROUNDWATER

Sola conducted hydrogeologic investigations at the site. Figure #3 provides a site diagram

locating all site wells. The aquifer beneath the Sola facility, as described earlier, is unconfmed and flows

in a south/southwest direction. VOC-contaminated groundwater extends from behind the Sola building

(where the underground tanks were formerly located) to the southwest corner of the Sola property. The

focus of the groundwater investigation was to assess the extent of contamination outside the zone of

capture of the extraction system constructed under the 1987 SFRWQCB Order.

In 1990, Sola installed nine additional monitoring wells. Samples taken from these and existing

groundwater monitoring wells confirmed that the VOC-contaminated groundwater (at concentrations

above clean-up standards) is largely limited to the Sola property (see Figure #4). These wells (LF-21

through LF-28) were installed:

to confirm downgradient lateral and vertical extent of VOC-contaminated groundwater;

and

to evaluate the distribution of VOC-affected groundwater in the deep sediment intervals

tapped by the City of Petaluma (Station #5) municipal well.

Water quality data from these new wells achieved these objectives. The primary VOCs detected

in groundwater samples from monitoring wells at the site are 1,1 -DCA; 1,1 -DCE; 1,1,1 -TCA; and Freon

113.

The highest concentrations of the primary VOCs have been detected in groundwater samples

collected from shallow well W14, which is located downgradient of the vicinity of the former storage

tanks. Water quality data from wells located on the downgradient edge of the Sola property (W33, LF25, LF-26 and LF-28) indicate that the lateral extent of VOC-contaminated groundwater within the Sola

property is at or below the clean-up standards. Figure #4 shows the distribution of VOC-contaminated

groundwater at shallow, intermediate, and deeper intervals. The VOC-contaminated groundwater in

deeper intervals does not meet clean-up standards in wells LF-17 and LF-13 and is not within the capture

of the current extraction system.

DATA QUALITY

EPA has collected split samples and independently analyzed these as a part of oversight

activities. EPA also had an independent contractor validate this data. Quality control criteria were met

for 98% of the data. EPA data and data collected by Sola are in good agreement. The relative percent

difference, an indication of precision, is less than 50% for the 15 sample pairs available for comparison.

EPA split data represents 20% of the total data used in the groundwater calculations in the risk

assessment.
STERO

\

/

f

/

STERO WELL

1/-27

- ROAD

(APPROXIMATE

ODH-2* LOCATION)

,PZ9

PZ6

C A 0 £R LANE

[7LF-28

.LF-6

ff^B-rjzr?-

E-8«*

-8«^

LF-5 LF^IS

,W31

'PZ7

LF-18

PZ3

W32

, PZ11

PZ10

W22

. W33

«LF-2

_W21

LF-3

0Wt9

W24

»*26

E-5

,PZ5 PZ2,

M E-6

•

o

W25

,WI8

-iTi

L.

t

" -FORMER STORAGE

TANKS LOCATION

MAIN

FACILITY

-B ,W17

STORAGE

BLDG

EXPLANATION

o Shafc* (up to appro. 30 b*l)

inonflOniQ WOT

• (ntamwU* (19 to «ppnn. 60

monitoring ml

• Dwp(H5toipprai. looted)

A On^r (up lo «pproi. 200 hoi)

monilonfig wefl

• DMp9* («pproi. >200 INI)

monitoring ml

PtaofMl* (

» EitadkmiMl

DH-2.0 ShttowmonnorhgwribBUMby

Donald Hwog * Anocfatm (Soum

ol DH-ZiNl location from *Em<ronimnM

Ste Amssiram. Lriwvife Business Pot.

P«UluM. Cdftxnla', prapaitd lor OOonmlIfophns • Rartnws, Sen Ffsnosco, Cflfiiornis

by OoraH Hgrtog « Assodales, Inc. Santa Ron.

California).

• " Ftndng

ISO TOT

SITE PLAN
PETALUMA

STATION 5

anr WELL

EXPLANATION

Shallow (up to appnn. 90 loci)

monitoring wd

Intermedia* (up to appro. 60 leel)

monitoring wed

Deep (op to appnn. 100 fed)

fnonrtoring well

Deeper (up lo appro*. 200 feel)

fnQndonntj wel

Deeped (approi. >200 led)

ntonBoring wefl

Estimated Imlt ol snatow-depth

o/oundwater capture

Shalow-depth groundwatef greater

than MCL's

tntermedate-deprh roundwater

greater than MCL's

Deep and deeper-depth groundwater

greater than MCU's

Fendng

Source: Levine-Fricke. 1990

VOC CONCENTRATIONS GREATER THAN

MCL'a IN SHALLOW, INTERMEDIATE.

DEEP, AND DEEPER-DEPTH QROUNDWATER

APRIL AND AUGUST 1990

CWHH/URDO28373.ES.EZ
VI. SUMMARY OF SITE RISKS

HUMAN HEALTH RISKS

The purpose of the Risk Assessment was to evaluate the public health and environmental risks

posed by VOCs detected in groundwater, soil, and soil-gas at the Sola site. The Risk Assessment Report

was completed by EPA's contractor in April 1991. Twelve VOCs at the site were identified as chemicals of potential concern. The twelve chemicals of potential concern are presented along with their

respective lexicological data in Table A.

The exposure assessment evaluated potential exposure pathways for the chemicals of potential

concern in groundwater, soil, and soil gas. The Risk Assessment assumes the maximum exposure

scenario. The exposure scenario assumes residential use of the groundwater. Pathways of exposure

include groundwater as a drinking water source and VOCs transported from groundwater or soil into

household air (eg., from showering and other domestic uses of water or soil gas that would seap directly

into buildings). Routes of exposure include ingestion of drinking water, dermal contact, and inhalation

of VOCs. The exposure assumptions used in the Risk Assessment are presented in Table B. The

concentrations used to calculate risk for soil gas exposure is based on a maximum concentration. The

concentrations used to calculate risk for groundwater exposure is based on the 95% upper confidence

limit on the mean concentration.

The lexicological assessment divided the twelve chemicals of concern by their carcinogenic or

non-carcinogenic effects. Six chemicals of concern were classified as known, probable, or possible

human carcinogens. The potential for carcinogenic effects was evaluated by estimating excess lifetime

cancer risk. Non-carcinogenic risk was assessed by comparing the estimated daily intake of a chemical

to the EPA-estimated safe level of daily exposure, or reference dose.

Soil Gas/Air Risks: EPA estimated potential health risks associated with soil gas contamination

at the Sola property based on diffusion of soil gas into the air of a building built over the area of soil and

groundwater contamination. Of the twelve chemicals of potential concern, ten were detected in soil gas.

The ten chemicals of potential concern in soil gas were used to calculate the risk posed by soil gas

contaminantion at the site. The ten chemicals of potential concern for soil gas are presented in Table

C along with the concentrations used to calculate the risk, the individual cancer risk associated with each

chemical at the concentration detected, and the non-carcinogenic risk. The excess lifetime cancer risk

for exposure to soil gas in air is 9x10-6(9 persons out of 1,000,000 people), as presented in Table C. The

non-carcinogenic health risks estimated by the Hazard Index rating indicates that no adverse health

effects are expected. In addition, Sola is an active manufacturing facility zoned for industrial use.

Groundwater Risks: The Risk Assessment provides an estimate of carcinogenic and non-carcinogenic effects from the domestic use of groundwater at the Sola site. Of the 12 chemicals of potential

concern, four contaminants were detected in groundwater. The four chemicals of potential concern and

the estimated risk for groundw*ater are included in Table D.

12
TABLE A

Chemical

Acetone

Butanone

1,1-Dichloroethane

1,2-Dichloroclhane

1,1-DicHfcroelhene

Freonll3

4-Meihyl-2-pentanone

Telrachlomelhene

Toluene

1,1,1-Trichloroelhanc

1 , 1,2-Trichloroelhane

Trichloroethene

Systemic Toxlclly

(mg/kR/day)

Oral RID

0.1

--

0.1

--

0.009

30

0.05

0.01

0.3

0.09

0.004

--

Reference

IRIS

--

HEAST

--

IRIS

IRIS

IRIS

IRIS

IRIS

IRIS

IRIS

--

Inhalation RID

--

--

O.I

--

--

--

0.02

--

0.57

0.3

--

--

Reference

--

--

HEAST

--

--

--

HEAST

--

HEAST

HEAST

--

--

Chemicals of Concern

Carcinogenic Potency

(mg/kg/day)-1

Oral Slope

Factor

--

--

--

0.091

0.6

--

--

0.051

--

-

0.057

0.011

Weight of

Evidence"

--

-•

C

B2

C

--

--

B2

--

--

C

B2

Reference

--

--

IRIS

IRIS

IRIS

--

--

HEAST

--

--

IRIS

HEAST

Inhalation

Slope Factor

--

--

-

0.091

1.2

-

--

0.0018

-

--

0.057

0.017

Weight of

Evidence*

--

-

C

B2

C

--

-

B2

-

--

C

B2

KCIVFMICC

«

--

IRIS

IRIS

IRIS

--

-

HEAST

--

-

IRIS

HEAST

"Group B: Probable human carcinogen. Sufficient evidence in animals and inadequate or no evidence in humans.

Group C: Passible human carcinogen. Limited evidence of carcinogenicily in animals in the absence of human data.

Notes:

HEAST Health Effects Assessment Summary Table, U.S. EPA 1990b.

IRIS Integrated Risk Information System, U.S. EPA, 1990a.

Information not available
The major contributor to both estimated cancer and non-cancer risks is 1,1 DCE. Only 1,1 DCE

has a numeric factor that can be used to calculate cancer risk. The excess lifetime cancer risk presented

by use of on-site contaminated groundwater for drinking water is 1 x 10-4 (1 person out of 10,000 people).

The non-carcinogenic risk estimate for contaminated groundwater indicates that no adverse noncarcinogenic health effects are expected.

The calculated VOC concentrations in groundwater were based on the average water quality data

from 28 monitoring wells. The calculated concentration for 1,1 DCE was 6. Ippb, which is close to the

clean-up standard and reflects approximately the same amount of risk as the clean-up standard. The

estimated risk for 1,1 DCE at the clean-up standard of 6 ppb is also 1x10-4.

ENVIRONMENTAL RISK

An Ecological Assessment was prepared as a pan of the Risk Assessment. The Ecological

Assessment focused on Adobe Creek. Adobe Creek is the closest surface water body and is the site of

a local project to reintroduce anadromous steelhead trout to the creek.

Water quality samples from groundwater monitoring wells installed between the Sola property

and Adobe Creek have not detected any contaminants, indicating that discharge of contaminants to

surface water has not occurred. In the absence of the current extraction system, groundwater from the

Sola facility would flow in the direction of Adobe Creek; however, contaminants detected in groundwater at the site are below their corresponding federal surface water quality criteria for the protection

of aquatic life.

SUMMARY

Releases of hazardous substances from the site presented the potential for an imminent and

substantial endangerment to public health, welfare and the environment. Interim pumping and treatment

of groundwater and removal of tanks and contaminated soil has reduced site risks; however, groundwater beneath the site still exceeds drinking water standards and warrants remedial action.

TABLE B

Assumptions used in Future-Use Scenarios

Parameter

Ingestion Rate

Inhalation Rate

Body Weight

Exposure Frequency

Exposure Duration

Years in Lifetime

Intake Value*

1 liter/day (child)

2 liter/day (adult)

20 m3/day (adult)

10 kg (child)

70 kg (adult)

365 days/year

30 years

25,550 days (70 years)

"Source: U.S. EPA, 1989a, 1989b, and 1989c.

14
TABLE C

Risk Characterization-Air Pathway

Chemical

Acetone

1, 1-Dichloroethane

1,2-Dichloroethane

1,1-Dichloroethene

Freon 113

Tetrachloroethene

Toluene

1,1, 1-Trichloroethane

1, 1,2-Trichloroethane

Trichloroethene

Total Risk

Air

Concentration"

(lig/1)

4.0 x 10'7

9.9 x 10*

5.9 x 10'7

5.8 x 10

 5

6.5 x lO'7

4.0 x 10-8

4.7 x 10-7

4.5 x 10*

2.5 x ID"6

7.5 x 10-8

Excess Lifetime

Cancer Risk

Estimate

—

~

6.6 x 10

 9

8.5 x 10*

—

8.8 x 10'12

—

—

1.7 x 10-8

1.6 x 10

 10

9x 10*

Hazard Index

1.1 x 10*

2.8 x 10'5

— 1.6 x 10

 3

6.2 x ID'9

1.1 x 10*

2.3 x 10

 7

4.3 x 10*

1.9 x 10-4

—

0.002

aMaximum concentrations

TABLE D

Risk Characterization-Groundwater Pathway

Chemical

1 , 1 -D ichloroethane

1,1-Dichloroethene

Freon 113

1,1,1 -Trichloroethane

Total Risk

Groundwater

Concentration"

(mg/1)

0.0011

0.0061

0.00063

0.0029

Cancer Risk

Estimate1*

—

1.4 x 1Q-*

--

—

IxlO" 1

Hazard Index

0.0022

0.14

0.0000042

0.0042

0.1

a

95 percent upper confidence limit on mean concentration

b

lngestion and inhalation routes summed together. The hazard index is based on

a child exposure scenario.

15
VII. DESCRIPTION OF ALTERNATIVES

This section will describe alternatives developed in the Feasibility Study. The five extraction

alternatives were evaluated and compared to the nine criteria required by the NCP (40 CFR Sec.

300.430(e)(9)). The nine criteria are: overall protection of human health and the environment;

compliance with applicable, or relevant and appropriate requirements (ARARs); long-term effectiveness and permanence; reduction of toxicity, mobility, or volume through treatment; short-term

effectiveness; implementability; cost; state acceptance; and community acceptance. The nine criteria

are described in more detail in Part VIII of this decision document, entitled Summary of Comparative

Analysis of Alternatives.

Each one of the alternatives in the Feasibility Study, with the exception of the no-action

alternative, complies with ARARs for the site. To comply with ARARs, an alternative must meet all

substantive Federal and State environmental laws and regulations.

The groundwater contamination at the Sola site is in a groundwater aquifer that has been

designated as a source of drinking water and has actually been proven to be in the same unconfined

aquifer used by the City of Petaluma municipal well (station #5 well). For these reasons, groundwater

must be restored to State and Federal drinking water standards. The drinking water standards or cleanup standards for the four contaminants identified in groundwater are presented in Table E. The

Primary VOCs in Ground Water

Chemical

1,1 DCE

1,1 DCA

1,1,1 TCA

Freon 1 1 3

1990 Maximum

Concentration (ppb)

Shallow Deep

1,400 22

280 1

220 10

9 2

Table E

and Clean-up Standards

Drinking Water

Standards (ppb)

State Federal

6 7

5

200 200

1,200 --

Clean-up

Standards (ppb)

6

5

200

1,200

alternatives described below, except the no-action alternative, are designed to meet these standards in

the aquifer over different restoration time periods.

Attainment of these levels in the aquifer will be protective of human health and the environment.

However, EPA recently studied the effectiveness of groundwater extraction systems in achieving

specified goals and found that it is often difficult to predict the ultimate concentration to which

contaminants in the groundwater may be reduced. Nevertheless, the study verified that groundwater

extraction is an effective cleanup measure and can achieve significant mass removal of contaminants.

The remedial alternatives described in this section are all based on extraction systems. The Agency

16
believes it is technically feasible to achieve the cleanup standards in the groundwater using extraction

systems.

After the contaminated groundwater is extracted it may be discharged to a surface water body

or to the local sewer system. These discharge options apply to all of the alternatives with the exception

of the no-action alternative.

If the water is discharged off-site to Adobe Creek it must be treated with the activated carbon

filter system at the facility. Alternatively, the water may be discharged to the city sewage treatment

facility. The City of Petaluma has an industrial discharge limit of 1 pan per million for total toxic

organics. Monitoring results from the extraction system indicate that contaminant concentrations in

groundwater are presently low enough to meet this standard without treatment.

Each alternative will require periodic groundwater monitoring to determine its effectiveness and

to verify achievement of the cleanup standards. The specific groundwater monitoring program will be

defined more precisely during Remedial Design/Remedial Action.

If the carbon filter treatment system is used, spent carbon must be handled in compliance with

the requirements of the Resource Conservation and Recovery Act (RCRA) and the California Hazardou s

Waste Control Law if waste (i.e. spent carbon) is stored for more than 90 days at the site.

ALTERNATIVE #1 - NO ACTION

The NCP requires that a no-action alternative be considered at every site. The no-action

alternative serves primarily as a point of comparison to other alternatives. This alternative is evaluated

to determine the risks that would be posed to public health and the environment if no action were taken.

With this alternative, the existing groundwater extraction treatment system would be shut down.

However, long-term monitoring of the site would be necessary to monitor contaminant migration.

Monitoring, using existing monitoring wells, can be easily implemented. Alternative #1 would rely on

natural processes in the groundwater to achieve cleanup standards. The time required for natural

processes to reduce contaminant concentrations to the cleanup standards is estimated to be 500 years.

The annual operation and maintenance (O&M) cost for alternative #1 would be $70,000. Since

the alternative requires "no-action" there would be no capital cost.

ALTERNATIVE #2

Alternative #2 is the continued operation of the current groundwater extraction system at the

current rate of 25-30 gallons per minute (gpm). The current system pumps groundwater from eight

existing extraction wells, each of which draw water from 20 to 30 feet beneath the ground surface.

Calculated time to achieve cleanup standards for this remedy is 25-30 years.

This alternative would provide capture for contaminanted groundwater with VOC concentrations above the cleanup standards in Table E, near the surface of the water table and down to

approximately 40-50 feet. VOCs have been found at concentrations which do not meet their respective

cleanup standards at depths below the capture of the current system. Under Alternative #2, these contaminants would be left to degrade through natural processes.

17
If the water is discharged off-site to Adobe Creek it must be treated with the activated carbon

filter system at the facility. Alternatively, the water may be discharged to the city sewage treatment

facility.

The net present value cost for this 25-30 year project would range between $2.5 and $2.7 million.

Capital costs would range up to $8,000 (piping and hook-ups), and annual O&M costs would be between

$153,166 and $166,650.

ALTERNATIVE #3

Alternative #3 is the continued operation of the current extraction system with two additional

shallow extraction wells. These wells would be placed in an area of high VOC concentration, reducing

the estimated clean-up time to 15-20 years.

This alternative would provide capture for those contaminants, at concentrations which do not

meet the cleanup standards in Table E, near the surface of the water table and down to approximately

40-50 feet. As discussed earlier, VOCs have been found in the groundwater which do not meet the cleanup standards at depths below the capture of the current system.

If the water is discharged off-site to Adobe Creek it must be treated with the activated carbon

filter system at the facility. Alternatively, the water may be discharged to the city sewage treatment

facility.

The net present value cost for this alternative would be between $2.0 and $2.1 million. Capital

costs range from $48,400 to $54,400, and annual O&M costs range from $156,814 to $167,350.

ALTERNATIVE #4

Alternative #4 converts two deep monitoring wells into extraction wells that will be intermittently pumped. This alternative would address the groundwater contamination, at concentrations which

do not meet the cleanup standards in Table E, beneath the zone of capture of the current extraction system

and would rely on the continued operation of the extraction wells in the current system to capture the

shallow contaminants. The time estimate to achieve clean-up standards is 25-30 years. The conversion

of deeper monitoring wells to extraction wells would prevent any further migration of contaminants in

the deeper portion of the aquifer.

If the water is discharged off-site to Adobe Creek it must be treated with the activated carbon

filter system at the facility. Alternatively, the water may be discharged to the city sewage treatment

facility.

The net present value cost for this alternative is $2.6 to $2.8 million. Capital costs range from

$28,400 to $34,400, and annual O&M costs range from $158,858 to $168,650.

18
ALTERNATIVE #5

Alternative #5 is EPA's selected remedy. Alternative #5 combines the actions of Alternatives

#3 and #4. The two additional shallow extraction wells, in conjunction with the existing wells, will

reduce the estimated time required to restore the shallow groundwater to clean-up standards in 15-20

years. The conversion of two deep monitoring wells (LF-13 and LF-17) to extraction wells will prevent any further migration of contaminants in to the deeper portion of the aquifer.

If the water is discharged off-site to Adobe Creek it must be treated with the activated carbon

filter system at the facility. Alternatively, the water may be discharged to the city sewage treatment

facility.

The reduced estimated time to achieve the clean-up standards also reduces the number of years

of O&M. Because of the reduced length of O&M, the ultimate cost is less than alternatives #3 or #4.

The net present value cost of this alternative ranges between $2.1 to $2.2 million. Capital costs would

be $74,000, and annual O&M costs range from $160,388 to $169,350.

VIII. SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES

The remedial alternatives developed in the FS were analyzed in detail using the nine evaluation

criteria required by the NCP. The resulting strengths and weaknesses of the alternatives were then

weighed to identify the alternative providing the best balance amoung the nine criteria. These criteria

are: 1) overall protection of human health and the environment; 2) compliance with applicable or

relevant and appropriate requirements (ARARs); 3) reduction of toxicity, mobility, or volume through

treatment; 4) long-term effectiveness and permanence; 5) short-term effectiveness; 6) implementability; 7) cost; 8) state acceptance; and 9) community acceptance. The nine criteria and the relative

performance of the alternatives in relation to each criterion and each other is summarized below.

PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT

Overall protection of human health and the environment addresses whether a remedy provides

adequate protection and describes how risks posed through each pathway are eliminated, reduced or

controlled through treatment, engineering controls, or institutional controls.

As the no-action alternative (#1) does not achieve the cleanup standards it will no longer be

discussed. Alternatives #2 through #5 are equally protective of human health and the environment by

eliminating or reducing the risk of exposure to contaminants in groundwater. Alternatives #2 through

#5 use engineering controls in the form of a groundwater extraction system to remove contaminated

groundwater from the aquifer where it could be used for consumption.

COMPLIANCE WITH ARARS *

Pursuant to section 121(d)(l) of CERCLA, remedial actions must attain a degree of clean-up

which assures protection of human health and the environment. Additionally, remedial actions must

meet standards, requirements, limitations, or criteria that are "applicable or relevant and appropriate"

(ARARs). Federal ARARs for any site include requirements under any federal environmental laws.

19
State ARARs include promulgated requirements under state environmental or facility-siting

laws that are more stringent than any Federal ARARs and have been identified to EPA by the state in

a timely manner.

Applicable requirements are those clean-up standards, control standards, and other substantive

environmental protection requirements, criteria, or limitations promulgated under Federal or State law

that specifically address a hazardous substance, pollutant, contaminant, remedial action, location or

other circumstance at a CERCLA site.

Relevant and appropriate requirements are defined as those cleanup standards of control and

other substantive environmental protection requirements, criteria, or limitations promulgated under

Federal or State law that, while not "applicable" to a hazardous substance, pollutant, contaminant,

remedial action, location or other circumstance at a CERCLA site, nevertheless address problems or

situations sufficiently similar to those encountered at the CERCLA site to indicate their use is well-suited

to the particular site. If no ARAR addresses a particular situation, or if an ARAR is insufficient to protect

human health or the environment, then non-promulgated standards, criteria, guidances, and advisories

(To Be Considered, or TBCs) must be used to provide a protective remedy.

Additionally, response actions which take place off-site must comply with all laws, administrative and substantive.

Types of ARARs

There are three types of ARARs. The first type includes "contaminant-specific" requirements.

These ARARs set limits on concentrations of specific hazardous substances, pollutants, and contaminants in the environment. Examples of this type of ARAR are ambient water quality criteria and drinking

water standards.

The second type of ARAR includes location-specific requirements that set restrictions on certain

types of activities based on site characteristics. These include restrictions on activities in wetlands,

floodplains, and historic sites.

The third type of ARAR includes action-specific requirements. These are technology-based restrictions

which are triggered by the type of action under consideration. Examples of action-specific ARARs are

Resource Conservation and Recovery Act (RCRA) regulations for waste treatment, storage, and

disposal.

ARARs are identified on a site-specific basis from information about specific chemicals at the

site, specific features of the site location, and actions that are being considered as remedies.

The following section will outline the Applicable or Relevant and Appropriate Requirements

(ARARs) and other information (TBCs) that EPA considered for this site.

CONTAMINANT-SPECIFIC ARARs and TBCs

Cleanup levels are set at health-based levels, reflecting current and potential use and exposure.

For systemic (noncarcinogenic) toxicants, cleanup levels represent that amount to which humans could

20
be exposed on a daily basis without unacceptable adverse effects occurring during their lifetime. For

carcinogens, cleanup levels must fall within a 10-4 to 10-6 risk range (NCP, 40 CFR §300.430

The contaminant- specific ARARs for the Sola site are Federal and State of California drinking

water standards. Each is relevant and appropriate to set as cleanup standards at the site. A list of Federal

and State drinking water standards are presented in Table E.

Federal Drinking Water Standards

Section 1412 of the Safe Drinking Water Act (SDWAX 42 U.S.C. §300g-l "National Drinking Water

Regulations": National Primary Drinking Water Regulations. 40 CFR Part 141.

Potential drinking water regulations include Maximum Contaminant Levels (MCLs) for

specific contaminants. MCLs are enforceable standards which apply to specified contaminants which

EPA has determined have an adverse effect on human health. MCLs are set at levels that are protective

of human health and set close to Maximum Contaminant Level Goals (MCLGs).

Under the authority of the NCP (40 CFR §300.430 (f)(5)), MCLGs set at levels above zero must

be attained by remedial actions for ground or surface water that is currently or potentially a sources of

drinking water, where the MCLGs are relevant and appropriate under the circumstances based on the

factors in NCP (40 CFR §300.400 (g)(2)). All of the MCLGs which are applicable to the Sola site are

less stringent than or equal to the federal MCLs.

Accordingly, the appropriate remedial standard for groundwater is the current federal or state

MCL, whichever is most stringent. Table E compares the current state and federal MCLs for the

chemicals of concern and identifies the cleanup standard.

State Drinking Water Standards

California Safe Drinking Act. California Domestic Water Quality Monitoring Regulations. CAC Title

22 Division 4. Chapter 15

California has promulgated MCLs for primary VOCs as shown in Table E. EPA has chosen the

California MCLs for primary VOCs as the groundwater cleanup standard for the site where the

California MCLs, for VOCs, was more stringent than federal MCLs.

ACTION-SPECIFIC ARARs AND TBCs

Treatment by Carbon Adsorption

Solid Waste Disposal Act, as amended by Resource Conservation and Recovery Act 42 U.S.C §6901

et seq.

Use of granular activated carbon (GAC) for remediation of VOCs can trigger requirements

associated with regeneration or disposal of the spent carbon. If the spent carbon is a listed waste or a

21
characteristic waste, it is regulated as a hazardous waste under RCRA and California's Hazardous Waste

Control Laws (CAC Title 22 §67520-67525).

Containers used for storage of hazardous waste on site for more than 90 days must be:

Maintained in good condition (40 CFR §264.171);

Compatible with other stored wastes (40 CFR § 264.172);

Closed during storage (40 CFR §264.173);

Inspected weekly (40 CFR §264.175);

Placed on a sloped, crack-free base with containment system in place capable of handling

10 percent of the free liquids stored (40 CFR §264.175);

Placed 50 feet from facility's property line if ignitable or reactive (40 CFR §264.176);

Separated by a dike or other barrier if incompatible wastes are stored near each other (40

CFR §264.177);

At closure, remove all hazardous wastes and residues from containment system (40 CFR

§264.178);

Storage of banned wastes must be in accordance with 40 CFR §268 (40 CFR §268.50).

On-site storage of contaminated carbon may trigger substantive requirements under state laws

(Hazardous Waste Control Law, CAC Title 22 §§67180-67194 and CAC §67240-67248) and municipal

or county hazardous material ordinances. If the spent carbon is a hazardous waste, construction and

monitoring requirements for storage facilities may also apply.

LOCATION-SPECIFIC ARARs AND TBCs

A site characterization was conducted at Sola to determine whether special characteristics

existed at the site which warranted location specific requirements. No location-specific requirements

were found.

LONG-TERM EFFECTIVENESS AND PERMANENCE

Long-term effectiveness and permanence refers to the ability of a remedy to maintain reliable

protection of human health and the environment over time. This criterion includes the consideration of

residual risk and the adequacy and reliability of controls.

Remedial alternatives #2 through #5 all result in minimal residual risk. Once the contaminants

in groundwater have been reduced to the cleanup standard concentration the primary risk will have been

permanently reduced. With the exception of the no-action alternative, all of the alternatives are expected

to attain clean-up standards in groundwater, thereby resulting in minimal risk from residual contaminants in groundwater. However, the residual risk posed by the contaminants at their respective cleanup

standards remains.

*

Extracted water will either be treated with the existing activated carbon filter system at the

facility and discharged off-site to Adobe Creek or discharged to the City sewage treatment system. In

both discharge options, adequate treatment would occur; either in the existing carbon filter system or

in the City sewage treatment system.

22
REDUCTION OF TOXICITY. MOBILITY. OR VOLUME THROUGH TREATMENT

Reduction of toxicity, mobility, or volume through treatment refers to the preference for a

remedy that uses treatment to reduce health hazards, contaminant migration, or the quantity of

contaminants at the site.

All of the alternatives, except the no-action alternative employ treatment, in varying degrees.

The discharge option employed will determine the type and location of treatment; discharge to Adobe

Creek will require prior treatment with the carbon filter system; while discharge to the Petaluma sewage

system will result in treatment prior to or in the sewage treatment system.

Extracted water will either be treated with the existing activated carbon filter system at the facility and

discharged off-site to Adobe Creek or discharged to the City sewage treatment system. The City of

Petaluma has an industrial discharge limit of 1 part per million (ppm) for total toxic organics.

Monitoring results from the extraction system indicate that concentrations in groundwater are presently

low enough to meet this standard without treatment.

Each of the alternatives, except the no-action alternative, is expected to attain clean-up standards

in groundwater, thereby resulting in minimal risk from contaminant residuals in groundwater. Spent

carbon filters containing the contaminants will be managed in compliance with ARARs.

SHORT-TERM EFFECTIVENESS

Short-term effectiveness refers to the period of time needed to complete the remedy and to any

adverse impacts on human health and the environment that may be posed during the construction and

implementation of the remedy.

Alternatives #2 through #5 are expected to pose no unacceptable short-term risks to the

community or workers during construction and implementation. Installation of the extraction wells

could be completed in one to two weeks.

Alternatives #3 or #5 are expected to attain clean-up standards in 15 - 20 years because of their

higher extraction volumes, pumping at approximately 35-40gpm. Alternatives #2 or #4 will pump

groundwater at an approximate rate 25-30 gpm resulting in an increased time of 25 -30 years to achieve

the cleanup standards in the aquifer. Alternative #2 will capture less contaminated groundwater than

other alternatives (#3 or #5) and it would leave deeper VOC-affected groundwater untreated and uncontrolled. Alternative #3 will capture a larger volume of contaminated shallow groundwater but it would

leave the deeper VOC-affected groundwater untreated and uncontrolled. Alternative #4 will reduce the

mobility of deeper VOC-affected groundwater by pumping contaminated monitoring wells but would

capture approximately the same volume of shallow groundwater as Alternative #2. Alternative #5 will

capture a larger volume of contaminated shallow groundwater and also decrease the mobility of deeper

VOC-affected groundwater. *

23
IMPLEMENT ABILITY

Implementability refers to the technical and administrative feasibility of a remedy, including the

availability of materials and services needed to implement the selected remedy. It also includes

coordination of Federal, State and local governments in cleanup of the site.

All of the alternatives are implementable. The installation of extraction wells involves well

known and frequently used method and materials.

The carbon filter treatment system has a current capacity of 60gpm and will not have to be upgraded if

it is used. All alternatives require groundwater monitoring.

COST

This criteria examines the estimated costs for each remedial alternative. For comparison, capital

costs and annual O&M costs are used to calculate a present worth cost for each alternative.

Alternative #2 would not incur any additional capital cost and the annual O&M expenditure on

the system would be approximately $166,000. Alternative #2 has a total $2.7 million net present value

with treatment and discharge to the creek or $2.5 discharging to the sewage treatment system. The latter

has a lower net present value because of a slightly lower O&M cost.

Alternative #3 would have approximately $8,000 in capital costs plus an approximate annual

O&M cost of $153,000. The net present value for alternative #3 is $2.1 million if treatment occurs onsite or $2.0 million if discharging to the sewage treatment system.

Alternative #4 would require an approximate capital cost of $46,000 and an approximate annual

O&M cost of $168,000. The total net present value is $2.8 million if treated in the carbon filter system

or $2.6 million if discharged to the sewage treatment system.

Alternative #5 has a capital cost of approximately $123,000 and an approximate annual O&M

cost of $169,000. The total net present value is $2.2 million if treatment in the carbon filter system is

used or $2.1 million if discharging into the sewage treatment system.

STATE ACCEPTANCE

State acceptance indicates whether, based on its review of the RI, FS, and Proposed Plan, the state

in which the site resides agrees with the preferred alternative.

EPA has involved the SFRWQCB during the development of the RI/FS and selection of the

remedy. SFRWQCB, on behalf of the State of California, has stated a preference, and concurs with

EPA, on the selection of alternative #5 as the preferred remedy.

24
COMMUNITY ACCEPTANCE

Community acceptance indicates the public support of a given alternative.

EPA solicited input from the community on the groundwater clean-up alternatives proposed for

the Sola Optical Site. The public did not oppose the preferred alternative. There was one written set of

comments received from one member of the community stating support for the preferred remedy. A

response to this set of comments is provided in Attachment B.

IX. SELECTED REMEDY

EPA has selected Alternative #5 as the remedy for the site. This remedy addresses groundwater

at the site and consists of:

groundwater monitoring to assure capture of contaminated groundwater and to demonstrate

restoration of groundwater to cleanup standards throughout the aquifer,

operation of existing extraction wells (8),

construction and operation of two (2) additional shallow extraction wells,

conversion of monitoring wells LF-13 and LF-17 to deep extraction wells,

construction and operation of additional piping for the new and converted wells,

on-site treatment and discharge off-site or discharge to the City of Petaluma sewage treatment

system.

The intent of this remedy is to restore groundwater to its beneficial use, which for this site is

drinking water. Based on information obtained during the remedial investigation and on a careful

analysis of all remedial alternatives, EPA and the State of California believe that the selected remedy

will achieve this objective.

The selection of this remedy is based on a comparative analysis of the alternatives presented

above and provides the best balance of trade-offs with respect to the nine evaluation criteria. The

selected remedy provides the fastest route towards achieving the cleanup standards and restoring the

groundwater to full beneficial use.

The selected remedy includes groundwater extraction for an estimated period of 15 to 20 years.

This groundwater extraction system will operate until the cleanup standards are achieved and continuously maintained throughout the aquifer. The cleanup standards are state or federally promulgated

drinking water standards. Until these standards are achieved and continuously maintained, EPA will

periodically re-evaluate the remedy every five years with the first evaluation in October 1993. At these

evaluations, if available EPA methodology is more accurate, the risks of soil/groundwater gases

migrating through the soil into potential residences on the site will be re-evaluated.

25
It may become apparent, during implementation or operation of the groundwater extraction

system, that contaminant levels have ceased to decline and are remaining constant at levels higher than

the cleanup standards. Based on the performance data, operation of the extraction system will be

adjusted as warranted if so determined during the periodic EPA evaluations. For example, it may be

appropriate to discontinue operation of extraction wells in areas where cleanup goals have been attained,

alternate pumping at wells to eliminate stagnation points, and pulse pump to allow aquifer equilibration

and encourage adsorbed contaminants to partition into groundwater for extraction.

Alternative #5 has a capital cost of approximately $123,000 and has an approximate annual

O&M cost of $ 169,000. The total net present value is $2.2 million if treatment in the carbon filter system

is used or $2.1 million if discharge is into the sewage treatment system.

X. STATUTORY DETERMINATIONS

The selected remedy is protective of human health and the environment as required by section

121 of CERCLA. The selected remedial action, when complete, shall comply with applicable or relevant

and appropriate environmental standards established under Federal and State environmental laws,

unless a statutory waiver is granted. The selected remedy is cost-effective, use permanent treatment

technologies or resource recovery technologies to the maximum extent practicable and includes

treatment as a principal element. The following sections discuss how the selected remedy for the Sola

site meets these statutory requirements.

PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT

Attainment of clean-up standards assures that the site risk falls within the acceptable range. The

cumulative site risk of 10-4 falls within the acceptable range (10-4 to 10-e). Alternatives #5 uses

engineering controls in the form of a groundwater extraction system to remove contaminated groundwater from the aquifer where it could be used for consumption. The extraction of VOC-contaminated

groundwater will significantly reduce the threat of exposure to residents. The implementation of this

remedy will not create any short-term risks nor any negative cross-media impacts.

ATTAINMENT OF ARARS

All ARARS would be met by the selected remedy. The selected remedy will achieve compliance

with chemical-specific ARARS by extracting groundwater with contaminant concentrations exceeding

the chemical specific cleanup standards. Action-specific ARARS will be met by both discharge options.

There are no applicable location-specific ARARS.

COST-EFFECTIVENESS

EPA believes the selected remedy is cost-effective and extracts the contaminated groundwater

within a reasonable period of time. The selected remedy fulfills the nine criteria and provides overall

effectiveness in relation to its cost.

26
Alternative #5 has an capital cost of approximately $123,000 and an approximate annual O&M

cost of $169,000. The total net present value is $2.2 million if discharged to the creek or $2.1 million

if discharging into the sewage treatment system.

USE OF PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT TECHNOLOGIES OR

RESOURCE RECOVERY TECHNOLOGIES TO THE MAXIMUM EXTENT PRACTICABLE

The selected remedy represents the maximum extent to which permanent solutions and treatment

technologies can be used in a cost-effective manner for the Sola site. Of those alternatives that are

protective of human health and the environment and comply with ARARS, EPA has determined that the

selected remedy provides the best balance: in long-term effectiveness and permanency; reduction of

toxicity, mobility and volume through treatment; short-term effectiveness; implementability, and cost

effectiveness; the selected remedy has also gained state and community acceptance.

PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT

VOC-contaminated groundwater will be extracted, and the VOCs will be treated. The treatment

will occur in the current on-site system using carbon adsorption to remove and concentrate the VOCs

or the treatment will occur in the sewage treatment system operated by the City of Petaluma. Therefore,

this remedy satisfies the statutory preference for remedies that employ treatment which permanently and

significantly reduces toxicity, mobility, or volume of hazardous substances as a principal element.

27
Page No.1

05/13/91

ATTACHMENT A

* SOLA OPTICAL USA INC

KTALUNA, CALIFORNIA

ADMINISTRATIVE RECORD FILE INDEX

AR # Roll # Frame * Date Author Addressee Subject

Mt 1 00/00/00 Chip Demarest

National Oceanic 1

Atmospheric

Administration

Site exposure potential, related

contamination & NOAA trust habitats &

species (undated, information for RPH

Michael Montgomery/EPA-9)

AR 2 87/07/28 Environmental

Protection Agency -

Region IX

HRS package w/attchs (list of

references, u/o reference #4)

AR 3 88/06/20 Jerry Clifford

Environmental

Protection Agency

Region IX

James Cox

Sola Optical USA,

Inc

Ltr: Proposal to add Sola Optical to

National Priorities List (NPL)

AR 4 88/08/23 Patricia Shanks

McCutchen, Doyle,

Broun & Enersen

Stephen tingle

Environmental

Protection Agency -

Office of Emergency

and Remedial

Response

Ltr: Comments on EPA proposal for NPL,

M/appendices A-C (SOLA'S statement re

Complaint #87-03, NPL site narrative &

revised factual statement)

AR 5 89/02/22 Michael Chee, Lester

Feldman

CA Regional Water

Quality Control

Board - San

Francisco Bay

Compliance monitoring rpt u/analytical

results (RWOCB Order #88-093) & TL to

Mark Adams/Sola Optical fr Lester

Feldman, 3/30/89

AR 6 89/04/05 Jerry Clifford

Environmental

Protection Agency -

Region IX

James Cox

Sola Optical USA,

Inc

General notice Itr w/concurrences (Date

taken fr last signature)

AR 7 89/04/19 s- Michael Montgomery

Environmental

Protection Agency -

Region IX

Michael Chee, et al

Environmental

Protection Agency -

Region IX

Memo: Request comments on technical

workplan, announce meeting on 5/1/89,

M/attch (Statement of work)

AR 8 89/05/09 James Cox Jerry Clifford Ltr: Response to general notice Itr of
Page No.2

05/13/91

• SOLA OPTICAL USA INC

PETALUMA, CALIFORNIA

— ADMINISTRATIVE RECORD FILE INDEX ••

AR * Roll Frame # Date Author Addressee Subject

Sola Optical USA.

Inc

Environmental

Protection Agency

Region IX

4/5/89

AR 9 89/05/16 Jerry Clifford

Environmental

Protection Agency

Region IX

Nark Adams

Sola Optical USA,

Inc

Special notice Itr for RI/FS,

w/certified nail receipts #P-918-448-

U2, H/O attchs

AR 10 89/05/31 Michael Montgomery Mark Adams

Environmental Sola Optical USA,

Protection Agency - Inc

Region IX

Ltr: Request copies of docs underlined

in reference list sent by Sola Optical,

w/ntarginalia

AR 11 89/06/15 Levine-Fricke Sola Optical USA,

Inc

Evaluation of implemented interim

remedial measures & proposed final

remedial measures on site

AR 12 89/07/07 Debbie Lowe

Environmental

Protection Agency

Region IX

Lynn Uoosley, City

Council

City of Petaluma

Ltr: Include addressee on mailing list &

CRP will be completed in 9/89, w/rtg

slip (7/12) to Michael Montgomery/EPA-9

indicating Itr to interviewees

AR 13 89/07/11 Debbie Lowe

Environmental

Protection Agency

Region IX

Mark Adams

Sola Optical USA,

Inc

Ltr: Prepare community relations plan

after interviewing community members,

u/rtg slip (7/12) to Michael Montgomery

Indicating same Itr sent to others

AR 14 89/07/12 Steven Ritchie

CA Regional Water

Quality Control

Board - San

Francisco Bay

Mark Adams

Sola Optical USA,

Inc

Ltr: Response to 6/15/89 request to

rescind order #87-038, u/mailing list

AR 15 89/07/17 Patricia Shanks

McCutchen, Doyle,

Brown £ Enersen

Allen Zabel

Environmental

Protection Agency

Region IX

Ltr: Good faith offer to conduct I

finance RI/FS proposed for site,

w/appendices 1, 4. w/o appendix 5

(redacted)
Page No.3

05/13/91

' SOLA OPTICAL USA INC

KTALUMA, CALIFORNIA

ADHINISTRATIVE RECORD FILE INDEX

AR * Roll * Frame # Date Author Addressee Subject

AR 16 89/07/24 Michael Montgomery

Environmental

Protection Agency -

Region IX

Nark Adams

Sola Optical USA,

Inc

Ltr: Response to Sola Optical's 7/17/89

good faith offer for RI/FS, w/certified

•ail receipts #P-918-tt7-091

AR 17 89/08/U Michael Montgomery

Environmental

Protection Agency -

Region IX

Mark Adams

Sola Optical USA,

Inc

Ltr: Conments on draft remedial

investigation feasibility study (RI/FS)

workplan of 8/2/89

AR 18 89/08/17 Jerry Clifford, John

Rothman

Environmental

Protection Agency -

Region IX

Daniel McGovern

Environmental

Protection Agency

Region IX

Memo: Request for 30-day extension to

the RI/FS negotiation moratorium on site

AR 19 89/08/17 Daniel McGovern

Environmental

Protection Agency

Region IX

Jerry Clifford, John

Rothman

Environmental

Protection Agency -

Region IX

Memo: Approve 30-day extension to Sola

Optical negotiation moratorium

AR 20 89/08/30 Levine-Fricke Sola Optical USA,

Inc

Remedial investigation feasibility study

(RI/FS) workplan, w/marginalia

AR 21 89/09/13 Michael Montgomery

Environmental

Protection Agency -

Region IX

Jeff Zelikson

Environmental

Protection Agency

Region IX

Memo: Request for signature on Sola

Optical site consent order t workplan,

u/o encl. u/rtg slip fr Michael

Montgomery to 5 EPA staff

AR 22 89/09/15 Michael Montgomery

Environmental

Protection Agency -

^Region IX

Mark Adams

Sola Optical USA,

Inc

Ltr: Technical scoping meeting for

development of sampling & analysis plan

AR 24 89/10/00 Environmental

Protection Agency

Region IX

Fact sheet: EPA signs agreement w/site

to continue investigation of groundwater

contamination
Page No.4

05/13/91

SOU OPTICAL USA INC

PETALUMA. CALIFORNIA

ADMINISTRATIVE RECORD FILE INDEX

AR * Roll f Frame * Date Author Addressee Subject

AR 23 89/10/00 Environmental

Protection Agency

Region IX

Conmunity relations plan (CRP)

AR 25 89/10/02 Jeff ZeUkson

Environmental

Protection Agency

Region IX

Richard Kapash

Sola Optical USA,

Inc

Administrative consent order for RI/FS

in mtter of Sola Optical USA Inc. USEPA

docket «89-22

AR 26 89/10/04 Michael Montgomery

Environmental

Protection Agency -

Region IX

Mark Adams

Sola Optical USA,

Inc

Ltr: Notify addressee that author is

EPA's designated Project Coordinator for

site

AR 27 89/10/10 Levine-Fricke Sola Optical USA,

Inc

Monthly rpt of hydrogeologic

investigations on site during 9/89

AR 28 89/10/11 Mark Adams

Sola Optical USA,

Inc

Michael Montgomery

Environmental

Protection Agency -

Region IX

Ltr: Confirm that monthly progress rpts

will be submitted to EPA on/before 15th

of each month

AR 29 89/10/16 City Council

City of Petali

Transcript (partial) of EPA presentation

at 10/16/89 City Council meeting, u/o

video tape, u/TL to Michael Montgomery

fr Mark Adams, 11/29/89

AR 31 89/10/16 Michael Montgomery

Envi ronmental

Protection Agency -

Region IX

Mark Adams

Sola Optical USA.

Inc

TL: Guidance on PRP sampling I analysis

plan development & notes fr Ecological

Assessment group

AR 30 89/10/16 Agreement between site I City of

Petaluna to shut down station 5 & SolaCity well, reinturse City for purchase

of substitute water, w/exhibit 1: Cost

AR 32 89/11/15 Levine-Fricke Sola Optical USA, Monthly status rpt of RI/FS activities
Page No.5

05/13/91

SOLA OPTICAL USA INC

PETALUMA. CALIFORNIA

— ADMINISTRATIVE RECORD FILE INDEX

AR * Roll * Frame # Date Author Addressee Subject

Inc during 10/89, u/o figure 1

AR 33 89/11/15 Nark Adams

Sola Optical USA.

Inc

Michael Montgomery

Environmental

Protection Agency -

Region IX

TL: Monthly status rpt of RI/FS

activities during 10/89 prepared by

Levine-Fricke u/attached distribution

list

AR 34 89/12/12 Michael Montgomery

Environmental

Protection Agency -

Region IX

Steve Simons, Water

Department

City of Petaluma

ROC: Confine destruction of Crandell

well & hook-up of Crandell property to

municipal system on 8/18/89 at Sola's

expense

AR 35 89/12/15 Levine-Fricke Sola Optical USA,

Inc

Monthly status rpt of RI/FS activities

during 11/89, w/TL to Michael

Montgomery/EPA-9 fr Mark Adams/Sola

Optical 1 marginalia

AR 36 89/12/29 Patricia Shanks

McCutchen, Doyle,

Brown & Enersen

Michael Montgomery

Environmental

Protection Agency -

Region IX

TL: Draft sampling & analysis plan (SAP)

I draft health £ safety plan (HSP) for

review & comment

AR 37 90/01/15 Levine-Fricke Sola Optical USA,

Inc

Monthly status rpt of RI/FS activities

during 12/89, w/TL to Michael

Montgomery/EPA-9 fr Mark Adams/Sola

Optical

AR 38 90/01/29 Donald Dalke

CA Regional Water

Quality Control

Board - San

Francisco Bay

Michael Montgomery

Environmental

Protection Agency -

Region IX

Ltr: Review field sampling plan dated

12/29/89 submitted by Sola Optical I

concur u/technical review by CH2M Hill,

M/mailing list

AR 39 90/01/29 * Michael Montgomery

Environmental

Protection Agency -

Region IX

Mark Adams

Sola Optical USA,

Inc

Ltr: Review comments on draft sampling &

analysis plan (SAP) dated 12/29/89,

w/attch #1

AR 40 90/02/U Mark Adams Michael Montgomery Ltr: Rationale for revised proposed
Page No.6

05/13/91

SOLA OPTICAL USA INC

PETALIMA, CALIFORNIA

— ADMINISTRATIVE RECORD FILE INDEX

AR # Roll # Frame # Date Author Addressee Subject

Sola Optical USA,

Inc

Environmental

Protection Agency

Region IX

•onitoring wells w/nap t TL fr Scott

Seyfried/Levine-Fricke, 2/16/90

AR 41 90/02/15 Levine-Fricke Sola Optical USA,

Inc

Monthly status rpt of RI/FS activities

during 1/90

AR 42 90/02/15 Mark Adams

Sola Optical USA,

Inc

Michael Montgomery

Environmental

Protection Agency -

Region IX

TL: Monthly status rpt of RI/FS

activities during 1/90 prepared by

Levine-Fricke w/attached distribution

list

AR 43 90/02/21 Steven Ritchie

CA Regional Water

Quality Control

Board - San

Francisco Bay

CRWQCB Order 90-030 (Rescind site

cleanup order 87-038 adopted on

4/15/87), M/TL to Mark Adams/Sola

Optical, 3/19/90

AR 44 90/02/26 Levine-Fricke Sola Optical USA,

Inc

Quality assurance project plan (QAPP)

AR 45 90/02/26 Levine-Fricke Sola Optical USA, Health & safety plan

Inc

AR 47 90/02/26 Mark Adams

Sola Optical USA,

Inc

Michael Montgomery

Environmental

Protection Agency -

Region IX

TL: Documents comprising sampling &

analysis plan dated 2/26/90 prepared by

Levine-Fricke w/attached distribution

list

AR 46 90/02/26 Levine-Fricke Sola Optical USA,

Inc

Field sampling plan hydrogeologic

investigations

AR 48 90/03/15 * Levine-Fricke Sola Optical USA,

Inc

Monthly status rpt of RI/FS activities

during 2/90, w/marginalie & TL to

Michael Montgomery/EPA-9 fr Mark

Adams/Sola Optical

AR 49 90/03/23 CH2M Hill Environmental Site safety plan
Page No.7

05/13/91

SOLA OPTICAL USA INC

PETALUMA, CALIFORNIA

— ADMINISTRATIVE RECORD FILE INDEX --

AR * Roll # Frame Date Author Addressee Subject

Protection Agency

AR 50 90/03/28 Levine-Fricke Environmental

Protection Agency

Responses to comments on revised QAPP by

Keith Egan of ICF Technology on 2/26/90,

w/TL to Michael Montgomery/EPA-9 fr Hark

Adams/Sola Optical, 4/2/90

AR 51 90/04/00 CH2H Hil l Environmental

Protection Agency

Region IX

Field sampling plan

AR 52 90/04/04 Planning Research Environmental

Corp Environmental Protection Agency,

Management, Inc Washington D.C.

Preliminary identification of potential

ARARs, cont# 68-U9-0009, UA# C09019 (TES

12, hazardous waste sites, zone IV,

regions 8-10)

AR 53 90/04/16 Levine-Fricke Sola Optical USA,

Inc

Monthly status rpt of RI/FS activities

during 3/90, w/TL to Michael

Montgomery/EPA-9 fr Mark Adams/Sola

Optical

AR 54 90/05/15 Levine-Fricke Sola Optical USA,

Inc

Monthly status rpt of RI/FS activities

during 4/90, w/TL to Michael

Montgomery/EPA-9 fr Mark Adams/Sola

Optical

AR 55 90/06/07 Michael Montgomery

Environmental

Protection Agency -

Region IX

Steven LuQuire, et

al

CA Regional Water

Quality Control

Board

Memo: Request comments on attch doc -

preliminary identification of potential

applicable or relevant I appropriate

requirements (ARARs), w/o encl

AR 56 90/06/14 Mark Adams

*Sota Optical USA,

Inc

Michael Montgomery

Environmental

Protection Agency -

Region IX

TL: Monthly status rpt of RI/FS

activities during 5/90 (dated 6/15/90) &

tri-annual groundwater Monitoring rpt

w/attached distribution list

AR 57 90/06/15 Levine-Fricke Sola Optical USA,

Inc

Combined monthly status rpt for 5/90 I

tri-annual groundwater monitoring rpt
Page No.8

05/13/91

SOLA OPTICAL USA INC

PETALUMA, CALIFORNIA

ADMINISTRATIVE RECORD FILE INDEX

AR Roll # Frame # Date Author Addressee Subject

completed during 4/90

AR 58 90/07/02 Levine-Fricke Sola Optical USA,

Inc

Soil investigation rpt

AR 59 90/07/02 Levine-Fricke Sola Optical USA,

Inc

Croundwater investigation rpt,

M/marginalia

AR 60 90/07/02 Hark Adams

Sola Optical USA,

Inc

Hichael Montgomery

Environmental

Protection Agency -

Region IX

TL: Draft groundwater investigation rpt

of 7/2/90 prepared by Levine-Fricke

u/attached distribution list

AR 61 90/07/02 Mark Adams

Sola Optical USA,

Inc

Michael Montgomery

Environmental

Protection Agency -

Region IX

TL: Draft soil investigation rpt

prepared by Levine-Fricke w/attached

distribution list

AR 62 90/07/18 Levine-Fricke Sola Optical USA,

Inc

Monthly status rpt of RI/FS activities

during 6/90, w/TL to Michael

Montgomery/EPA-9 fr Gregson

TayIor/Levi ne-Fr i eke

AR 63 90/07/26 Jerry Clifford

Environmental

Protection Agency

Region IX

Mark Adams

Sola Optical USA,

Inc

Ltr: Reimbursement of EPA costs,

w/concurrences, encl (redacted) t nail

receipts 0P918-448-210

AR 64 90/08/15 Levine-Fricke Sola Optical USA,

Inc

Monthly status rpt of RI/FS activities

during 7/90, w/TL to Michael

Mont9omery/EPA-.9 fr Mark Adams/Sola

Optical

AR 65 90/08/15 Levine-Fricke Sola Optical USA,

Inc

Response to EPA comments on draft soil &

grounduater investigation rpts, w/attch

1 (7/18/90 EPA comments u/TL), I TL to M

Montgomery fr S Seyfried
Page No.9

05/13/91

SOLA OPTICAL USA INC

PETALUMA, CALIFORNIA

ADMINISTRATIVE RECORD FILE INDEX

AR # Rot I # Frame # Date Author Addressee Subject

AR 66 90/08/24 Michael Montgomery

Environmental

Protection Agency -

Region IX

Nark Adams

Sola Optical USA,

Inc

Ltr: Conf ir* discussion at Meeting of

7/20/90 re feasibility study schedule

AR 67 90/OS/27 Mark Adams

Sola Optical USA,

Inc

Environmental

Protection Agency -

Superfund Accounting

Ltr: Reimburse EPA site-related response

t oversight costs

AR 68 90/09/14 Levine-Fricke Sola Optical USA,

Inc

Monthly status rpt of RI/FS activities

during 8/90, w/TL to Michael

Montgomery/EPA-9 fr Mark Adams/Sola

Optical

AR 69 90/10/12 Levine-Fricke Sola Optical USA,

Inc

Combined monthly status rpt for 9/90 &

semi-annual groundwater monitoring rpt

completed between 8/27 I 9/11/90

(Appendix A)

AR 70 90/11/01 Michael Montgomery

Environmental

Protection Agency -

Region IX

Mark Adams

Sola Optical USA,

Inc

Ltr: Comments on draft remedial

investigation rpt of 10/1/90, request

for revised yorkplan schedule in final

RI rpt ft meeting on 11/5/90

AR 71 90/11/06 Steve Ihnen

Environmental

Protection Agency

Region IX

Michael Montgomery

Environmental

Protection Agency -

Region IX

Memo: Classification of grounduaters at

Sola site

AR 72 90/11/15 Levine-Fricke Sola Optical USA,

Inc

Monthly status rpt of RI/FS activities

during 10/90, H/TL to Michael

Montgomery/EPA-9 fr Mark Adams/Sola

Optical

AR 73 90/12/03 Levine-Fricke Sola Optical USA,

Inc

Remedial investigation rpt

AR 74 90/12/12 Mark Adams Michael Montgomery Ltr: Discuss aspects of RI/FS - request
*» -*t

Page No.10

05/13/91

SOLA OPTICAL USA INC

PETALUHA, CALIFORNIA

— ADMINISTRATIVE RECORD FILE INDEX

AR * Roll * Frame * Date Author Addressee Subject

Sola Optical USA, Environmental

Inc Protection Agency

Region IX

EPA assumptions re containnants of

concern, exposure pathways I calculation

of exposure concentrations

AR 75 90/12/13 Levine-Fricke Sola Optical USA,

Inc

Monthly status rpt of RI/FS activities

during 11/90, w/TL to Michael

Montgomery/EPA-9 fr Mark Adams/Sola

Optical

AR 76 91/01/02 Michael Montgomery Mark Adams

Environmental Sola Optical USA,

Protection Agency - Inc

Region IX

Ltr: Request written response to

comments on RI rpt of 12/3/90 (attch 1),

w/o UA rpts for 9/90 & 11/90 (attch 2) &

draft fact sheet (attch 3)

AR 77 91/01/15 Levine-Fricke Sola Optical USA,

Inc

Combined monthly status rpt for 12/90 &

tri-annual grounduater Monitoring rpt

(Appendix A)

AR 78 91/02/00 Environmental

Protection Agency -

Region IX

Fact sheet: Remedial investigation

complete - contamination largely limited

to site property

AR 79 91/02/08 Levine-Fricke Sola Optical USA,

Inc

Detailed analysis of remedial

alternatives, u/narginalia

AR 80 91/02/U Levine-Fricke Sola Optical USA,

Inc

Monthly status rpt of RI/FS activities

during 1/91

AR 81 91/02/15 Levine-Fricke Sola Optical USA,

Inc

Technical nemo presenting results of

subsurface transport Modeling

AR 82 91/04/00 CH2M Hill Environmental

Protection Agency

Public health risk assessment, w/attchs

I (draft technical nemo - results of

subsurface transport Modeling. 2/5/91) &

II (VLEACH model)

AR 83 91/05/08 Environmental

Protection Agency

List of guidance documents
Page No.1

06/14/91

SOLA OPTICAL USA, INC.

PeteIuna, California

ADMINISTRATIVE RECORD FILE INDEX

Supplement No. 1

Alt * Date

yy/imi/dd

Author Addressee Subject

AR 84 91/02/28 Michael Montgomery

Environmental

Protection Agency •

Region 9

AR 85 91/03/15 Levine-Fricke

AR 86 91/03/15 Mark Adams

Sola Optical USA,

Inc

AR 87 91/03/25 Mark Adams

Sola Optical USA,

Inc

AR 88 91/03/26 Chip Demarest

National Oceanic &

Atmospheric

Administration

AR 89 91/04/12 Levine-Fricke

AR 90 91/04/12 Charles Noyes

CA Regional Water

Quality Control

Board - San

Francisco Bay

AR 91 91/05/14 Michael Montgomery

Environmental

Protection Agency -

Region 9

AR 92 91/05/16 Michael Montgomery

Environmental

Protection Agency -

Region 9

AR 93 91/05/21 1CF Technology. Inc

Mark Adams

Sola Optical USA,

Inc

Sola Optical USA,

Inc

Michael Montgomery

Envi ronmentel

Protection Agency -

Region 9

Michael Montgomery

Environmental

Protection Agency -

Region 9

Michael Montgomery

Environmental

Protection Agency -

Region 9

Sola Optical USA,

Inc

Michael Montgomery

Environmental

Protection Agency -

Region 9

Mark Adams

Sola Optical USA,

Inc

Mark Adams

Sola Optical USA,

Inc

Ltr: Comments on detailed analysis of

remedial alternatives rpt of 2/8/91, w/o

further comments on docs re results of

subsurface transport modeling

Monthly status rpt of RI/FS activities

during 2/91

Ltr: Installation of well LF-27A & TL

for monthly status rpt of RI/FS

activities during 2/91 prepared by

Levine-Fricke

Ltr: Propose submittal date of draft FS

be three calendar weeks after receipt of

Baseline Public Health Evaluation (BPHE)

by Sola, w/marginalia

Ltr: Review comments on ecological

assessment portion of draft public

health risk assessment of site

Monthly status rpt of RI/FS activities

during 3/91, w/TL to Michael

Montgomery/EPA-9 fr Mark Adams/Sola

Optical

Ltr: No additional comments on draft

copy of public health risk assessment

(RA) after preliminary review

Ltr: Preliminary comments on draft FS

rpt u/attchs (Draft Itr of comnents fr

CRUOCB-SF to M Montgomery on FS rpt &

7/30/90 nemo re water quality ARAR)

Ltr: Final comnents on draft feasibility

study rpt dated 4/15/91, u/attchs

Data validation rpt, w/attchs (TL to

Michael Montgomery/EPA-9 fr Victoria

Taylor/ICF Technology 8 5/15/91 request
Page No.2

06/U/91

SOLA OPTICAL USA, INC.

Petaluma, California

ADMINISTRATIVE RECORD FILE INDEX

Supplement No. 1

AR * Date

yy/mn/dd

Author Addressee Subject

AR 94

AR 95

AR 96

91/06/00 Environmental

Protection Agency

Region 9

91/06/10 Levine-Fricke

91/06/13 Santiago Lee

Planning Research

Corp Environmental

Management, Inc

Sola Optical USA,

Inc

Environmental

Protection Agency -

Office of Waste

Programs Enforcement

for data validation fr EPA-9)

Fact sheet: EPA announces proposed plan

for cleanup on site

Feasibility study rpt

Technical review of split sample data &

PRP data, cont# 68-U9-0009. UA# C09019

(TES 12, hazardous waste sites, zone IV,

regions 8-10)
i. I

SOLA OPTICAL USA, IMC. 8UPERFUND SITE

Petaluma, California

ADMINISTRATIVE RECORD FILE

&

INDEX

Supplement No. 2

Documents: AR97-AR100

July 2, 1991
SOLA OPTICAL U8A, INC. BDPERPUKD SITE

Petaluma, California

Administrative Record File Index

Supplement Number 2

This Administrative Record File Index, Supplement Number 2, lists

the documents added to the Administrative Record File for the

Sola Optical USA, Inc. Superfund Site, Petaluma, California,

since June 14, 1991 after the compilation of Supplement No 1.

The Index presents the documents in ascending chronological order, reflecting the organization of the documents in the file.

Each document has been assigned a unique number for purposes of

identification. These are indicated as "ARxx". Numbering of the

documents in Supplement No. 2 begins where the Supplement No. 1

left off; thus the first document is numbered "AR97".

Please note that the original Administrative Record File consists

of documents #1 - 83 arranged chronologically from 7/28/87 to

5/8/91. Supplement No. l consists of documents IAR84 - AR96 arranged chronologically from 2/28/91 to 6/13/91. Supplement No. 2

consists of documents #AR97 - AR100 from 1/22/91 to 6/14/91. Because of the overlap in dates, it is necessary to use all three

indices to locate documents for a particular date.

The documents contained in the Administrative Record File are

used by the U.S. Environmental Protection Agency in identifying

appropriate response action for the Sola Optical USA, Inc. Superfund Site.
Page No.1

07/02/91

SOLA OPTICAL USA, INC.

Petaluroa, California

ADMINISTRATIVE RECORD INDEX

Supplement No. 2

AR # Date Author Addressee Subject

yy/mm/dd

AR 97 91/01/22 Michael Montgomery Mark Adams Ltr: Response to 12/12/90 inquiry re

Environmental Sola Optical USA, risk assessment in progress & describe

Protection Agency - Inc each exposure pathway addressed in first

Region 9 risk assessment (RA) draft

AR 98 91/06/04 Michael Montgomery Mark Adams Ltr: Comments on revised section 5.0 of

Environmental Sola Optical USA, Sola feasibility study rpt dated 5/29/91

Protection Agency - Inc

Region 9

AR 99 91/06/11 Vicki Rosen M Patricia Memo: Public comment period - 6/17-

Environmental Hilligoss, Mayor, et 7/16/91 & public meeting will be on 6/25

Protection Agency - al at Veterans Memorial Building, w/attch

Region 9 City of Petaluma (Advance copy of EPA proposed plan)

AR 100 91/06/14 Levine-Fricke Sola Optical USA, Monthly status rpt of RI/FS activities

Inc during 5/91, w/appendix A (response to

EPA 1/2/91 comments on RI rpt) & TL to M

Montgomery fr M Adams
Attachment B

SOLA OPTICAL SDPERFUND SITE

PETALUMA, CALIFORNIA

RESPONSIVENESS SUMMARY

A. OVERVIEW

At the time of the public comment period, EPA proposed a

preferred alternative for the Sola Optical Superfund site in

Petaluma, California. EPA's recommended alternative addressed

the groundwater contamination problem at the site. The selected

remedy specified in the Record of Decision (ROD) calls for two

new extraction wells and the conversion of two deep monitoring

wells to extraction wells within Sola's existing treatment

system.

Judging from the few comments received during the public

comment period, as well as the few people who attended the public

meeting on the proposed plan, there is little community concern

about risk from the Sola site. EPA's clean-up alternative

appears to be supported by area residents.

These sections follow:

* Background on Community Involvement;

* Summary of Comments Received during Public Comment

Period and Agency Responses;

* Community Relations Activities at Sola Optical site.

Bi Background on Community involvement

There has been relatively little community interest in the

Sola Optical site and no organized community involvement.

Following local newspaper articles on the site's proposed listing

on the National Priorities List in 1988, City and County

officials reported some inquiries from the general public. These

inquiries sought information and reassurance that the drinking

water supply was safe. The public seemed satisfied with the

answers provided. The local community wanted to be kept informed

of site activities throughout the Superfund process, and EPA has

communicated with the public through various community relations

activities. To summarize past community involvement, it would be

fair to state that most residents seemed satisfied with the

information they received about the site, and confident in the

work EPA and Sola were conducting during the Remedial

Investigation/Feasibility Study (RI/FS).
C: Summary of Comments Received during Public Comment Period and

Agency Responses

Comments raised during the Sola Optical public comment period

on the proposed plan are summarized below. The comment period was

held from June 17 to July 16, 1991. All of the following comments

were expressed in a letter mailed to EPA from one Petaluma family

and represent the extent of comments on the proposed plan.

Although a public meeting on the proposed plan was held during the

public comment period, no comments specific to the proposed plan

were made at that meeting.

1. EPA's preferred clean-up alternative was supported.

2. Concern was expressed about possible adverse environmental and

health impacts related to the transport and disposal of the

used charcoal filter from the treatment system.

EPA Response: Carbon filters are contained in their own

Department of Transportation-approved transportable vessels.

Spent carbon filters have been shipped in these vessels to a

carbon-regeneration facility in the State of Washington where

they have been thermally regenerated.

3. The comment was made that the disposal of contaminated

water into the sanitary sewer is contrary to the City of

Petaluma's plan to compost the treatment plant sludge for

agricultural, parks and other uses. Additionally, this

resident expressed concern that the chemicals remaining in the

treated water could pollute the Russian River and Sonoma Coast.

EPA Response; Contaminated water would be effectively treated

in the treatment works of the sewage system. Volatile organic

compounds (VOCs) in the contaminated groundwater discharged

into the City of Petaluma sewage treatment system would likely

volatilize or biodegrade in the treatment works. The sewage

treatment system does not discharge into the Russian River or

Sonoma Coast. Additional questions regarding the quality of

discharge from the city sewage treatment works should be

directed to Steve Simmons, Water Services Department, City of

Petaluma, 11 English Street, Petaluma, CA 94952,

(707) 778-4392.
4. Concern about the water quality of the Petaluma River was

expressed. The commenter disagreed with the determination that

chemicals entering it from the Sola Optical site were insignificant.

EPA Response: Water quality data from monitoring wells at the

Sola property line are at or below state or federal drinking

water standards. Given the distance to the Petaluma River

(one mile), it is highly unlikely that any chemicals from

Sola's groundwater contamination are entering the Petaluma

River.

5. A question was posed regarding groundwater quality at a

residential area 500 feet from the Sola site. This community

member wondered whether it was possible that Sola's

contaminated groundwater had leached into this neighborhood or

could in the future. If so, this person wanted to know the

long-term effects of such leaching, especially as it concerns

children playing in the backyards or vegetables grown in the

soil.

EPA Response: No residential neighborhood has an elevated risk

to human health or the environment from Sola groundwater

contamination. Both shallow and intermediate depth monitoring

wells located between the Sola property and the residential

area described by the commenter have detected no contamination.

EPA will continue to monitor these wells, though it is unlikely

that Sola contamination will show up in this neighborhood, as

it is upgradient from the site. Regarding future leaching of

the contamination, besides the upgradient factor, the

extraction system is designed to capture Sola's contaminated

groundwater.

6. The question was posed as to what caused the contamination

at Sola and what Sola is doing to prevent this same problem

from happening in the future.

EPA Response: According to reported data, when the underground

storage tanks were removed there were no leaks detected, but

there was staining of the back-fill gravel surrounding the

tanks. This infers that a spill occurred on the surface near

the tanks. This same problem will not happen in the future

because Sola has filled in the gaps in the concrete that had

overlayed the tanks, discontinued the use of underground tanks

and instituted further controls on the use of chemicals.

Further questions regarding spill prevention and safety

precautions should be directed to Mark Adams, Manager of

Environmental Affairs, Sola Optical, 1500 Cader Lane, P.O. Box

6002, Petaluma, CA 94953, (707) 763-9911.
7. EPA was asked why Sola does not use less hazardous or nontoxic chemicals.

EPA Response: The total number of solvents used by Sola has

been reduced to one, which is acetone. Further questions

regarding processes used by Sola should be directed to Mark

Adams at Sola Optical (see above #6).

D: Community Relations Activities at Sola Optical Site

Community relations activities conducted at the Sola Optical

site to date have included the following:

* EPA conducted community interviews with local

officials and interested residents (June 1989) ;

* EPA prepared community relations plan (October 1989) ;

* EPA prepared and distributed fact sheet to affected

community and other interested parties announcing

agreement with Sola to continue investigation of

groundwater contamination (October 1989);

* EPA made locally televised presentation of workplan for

Remedial Investigation/Feasibility Study (RI/FS) to

Petaluma City Council (October 1989) ;

* EPA prepared and distributed fact sheet to affected

community and other interested parties announcing

completion of Remedial Investigation (February 1991);

* EPA prepared and distributed proposed plan for cleanup

(June 1991);

* EPA ran public notice in Santa Rosa Press Democrat

announcing proposed plan, dates of public comment

period and date of public meeting (June 17, 1991);

* EPA held public meeting at Petaluma's Veterans

Memorial Building to discuss and receive comments on

the proposed plan (June 25, 1991). A transcript of

this meeting is in the Petaluma Public Library;

* EPA's public comment period on the proposed plan lasted

from June 17 to July 16, 1991.