SFUN D RECORD S CT R 2201-0011 1

i SFUND RECORD S CT R

9445 3 SFUN D RECORD S CT R 

### 8815161 3 

# AR0105 SOL A OPTICA L SUPERFUN D SIT E 

# RECOR D O FDECISIO N

U.S . EP A

### Hazardou s Wast e Managemen t Divisio n Concurrenc e 

### Sol a Optica l sit e Recor d o f Decisio n

- 2 7 ~ 

### son , Directo r Wast e Managemen t Divisio n Dat e

### Concurrence s Sol a Optica l Sit e Recor d o f Decisio n

Davi d Hdwekamp,Dirfqto r Dat e Ai r an d Toxic s Divi s

Nor a McGe e Dat e Assistan t Regiona l Administrato r Offic e o f Polic yand Managemen t

Nanc yMarvel , Regiona l Counse l Dat e Offic e o f Regiona l Counse l

Harr ySeraydarian , Directo r Dat e Wate r Managemen t Divisio n

### Concurrence s Sol a Optica l Sit e Recor d o f Decisio n

Davi d Howekamp , Directo r Dat e Ai r and Toxic s Divisio n 

# 7--Z.5-? / Nor a McGe e Dat e Assistan t Regiona l Administrato r Offic e o f Polic yand Managemen t

Nanc yMarvel , Regiona l Counse l Dat e Offic e o f Regiona l Counse l

HarrySeraydarian , Directo r Dat e Wate r Managemen t Divisio n

### Concurrence s Sol a Optica l Sit e Recor d o f Decisio n

Davi d Howekamp , Directo r Dat e Ai r and Toxic s Divisio n

Nor a McGe e Dat e Assistan t Regiona l Administrato r Offic e o f Polic yand Managemen t

Nanc yMegrvea , Regiona l Counse l D a Offic e o f Regiona l Counse l

Harr ySeraydarian , Directo r Dat e Wate r Managemen t Divisio n

### Concurrence s Sol a Optica l Sit e Recor d o f Decisio n

Davi d Howekamp , Directo r Dat e Ai r an d Toxic s Divisio n

Nor a McGe e Dat e Assistan t Regiona l Administrato r Offic e o f Polic yand Managemen t

Nanc yMarvel , Regiona l Counse l Dat e Offic e o f Regiona l Counse l


# SE P 2 4 199 1



# _ Harr ySeraydarian , Directo r Dat e ate r Managemen t Divisio n

### TABL E O F CONTENT S Pag e

Lis t o f Figure s i i Lis t o f Table s i i Declaratio n fo r

th e Recordo f

Decisio n 1 Decisio n Summar y 3 I . Sit e Name , Locatio n an dDescriptio n 3 II . Site History an dEnforcemen t Activitie s 5 III . Highlight s o f

Communit y Involvemen t 6 IV . Scop e an dRol e o f th e Respons e Actio n 6 V . Summar y o f

Sit e Characteristic s 7 VI . Summar y o f

Sit e Risk s 1 2 VII . Descriptio n o f

Alternative s 1 6 VIII . Summar y o f

Comparativ e Analysi s o f Alternative s 1 9 IX . Selecte dRemed y 2 5 X . Statutor y Determination s 2 6 ATTACHMEN T A : Administrativ e RecordFil e Inde x ATTACHMENT B : Responsivenes s Summar yLIS T O F FIGURE S Pag e

Figure # 1 Sit e an dVicinit y Map 4 Figure # 2 Chemical Concentration s Detecte di n Soil-Ga s Sample s -

Apri l 1990 8 Figur e # 3 Site Pla n 1 0 Figure # 4 VOC-Contaminate dGroundwate r b y Depth , wit h Shallo w Captur e Lin e - Apri l 199

0 1 1
LIS T O F TABLE S Pag e Tabl e A Chemical s o f Concern 1 3 Tabl e B Exposur e Assumption s use di n Future-Us e Scenario s 1 4 Tabl e C Ris k

Characterizatio n —Ai r

Pathwa y 1 5 Tabl e D Ris k

Characterizatio n - - Groundwate r Pathwa y 1 5 Tabl e E Primary VOC s i n Groundwate r an dClean-u p Standard s 1 6



### 1 1

## Declaratio n fo rth e Recor d o f Decisio n SIT E NAM E AN D LOCATIO N Sol aOptical USA , Inc . 150 0 Cade r Lan e P.O . Bo x 6002 Petaluma , C A 94953-600 2 STATEMEN T O FBASI S AN D PURPOS E Thi s decisio n documen t

present s th e remedial actio n selecte dfo r th e Sol aOptical US A (Sola ) sit e i n Petaluma , California . Thi s remedial actio n wa s chose n i n accordanc e wit h th e Comprehensiv e Environ
menta l Respons e Compensatio n an dLiabilit y Ac t (CERCLA) , a s amende db y th e Superfun dAmend
ment s an dReauthorizatio n Ac t (SARA) , and , t o th e exten t practicable , wit h th e Nationa l Oi l an d Hazardou s Substance s Pollutio n Contingenc y Plan (NCP) . Thi s i s th e firs t an dfina l remed y an dther e ar e n o additiona l operabl e units . Thi s decisio n i s base do n th e administrativ e recordfo r thi s site . Th e attache dAdministrativ e Record Inde x (Attachmen t

A ) identifie s th e document s upo n whic h th e decisio n i s based . Th e Stat e o f

Californi aconcur s wit h th e selecte dremedy . ASSESSMEN T O FTHE SITE Sol adiscovere dsolvent s i n th e groundwate r an di n th e soil s adjacen t

t o thei r undergroun dstorag e tanks . Sol aremove dthe undergroun dtank s andthe adjacen t soils . Sol ahas constructe dandis presentl y operatin g agroundwate r

extractio n an dtreatmen t

system . However , residua l groundwate r contamina
tio n require s tha t

additiona l work , a s actua l o r threatene drelease s o f

hazardou s substance s fro mthi s site , i f no t addresse db y implementin g th e respons e actio n selecte di n thi s Recordo f Decisio n (ROD) , may presen t a n imminen t

an dsubstantia l endangermen t t o publi c health , welfare , o r th e environment . DESCRIPTIO N O FTH E REMED Y Th e selecte dremed y fo r

contaminate dgroundwate r a t th e Sol asit e consist s of : groundwate r

monitorin g t o demonstrat e captur e o f th e contaminan t

plum e an d ultimately , achievemen t

o f th e cleanu p standard ; operatio n o f

existin g extractio n wel l system ; constructio n an doperatio n o f tw o additiona l extractio n well s an dpiping ; an d conversio n o f

tw o dee p monitorin g well s to extractio n wells .

### By full y addressin g the groundwate r contaminatio n at

the site , the remedy woul dreduc e the principa l ris k fro mth e site . Sol aaddresse dth e principa l threat s pose db y th e site whe n the y remove dth e undergroun dtank s an dth e contaminate dsoil s adjacen t t o th e tanks . Thes e interi mactions , conducte d prio r t o EP A involvement , were no t inconsisten t

wit h th e fina l remed y chose n b y EPA . Implementatio n o f

thi s remed

y wil l increas e th e rate o f groundwate r

cleanu p i n a

n are awhere th e groundwate r

contaminatio n i s highest . I t wil l als o addres s th e lo w level s o f contaminatio n foun di n tw o deeper on-sit e monitorin g wells . Thi s groundwate r extractio n syste mwil l operate unti l th e cleanu p standard s ar e achieved . Unti l thes e standard s ar e achieved , evaluatio n o f th e remed y wil l continu e at a frequenc y t o b e determine ddurin g th e remedia l design . STATUTOR Y DETERMINATION S Th e selecte dremedy i s protectiv e o f huma n health an dth e environment , complie s wit h Federa l an dStat e requirement s tha t

ar e legall y applicabl e o r

relevan t an dappropriate t o th e remedia l action , an di s cost effective . Thi s remed y use s permanen t solution s an dalternativ e treatmen t technologie s t o th e maximu m exten t practicabl e an dsatisfie s th e statutory preferenc e fo r remedie s tha t

emplo y treatmen t

t o reduc e toxicity , mobility , o r

volum e a s aprincipa l element .\JLK

### Danie l W/McGovern ^

_Date Regiona l Administrato r

## Decisio n Summar y

I . SIT E NAME , LOCATIO N AN D DESCRIPTIO N SIT E NAM E AN D LOCATIO N Th e Sol asite i s locate di n southern Sonom aCounty , California , o n th e southeastern edg e o f th e Cit y o f Petalum a(Se e Figur e 1) . Sol aha s bee n manufacturin g ophthalmi c lense s sinc e 197 8 at it s 35
- acr e facilit y i n Petaluma' s industria l area . Th e facilit y addres s i s 150 0 Cader Lan e an di s locate djus t wes t o f Lakevill e Highway , sout h o f th e Lakevill e Highwa y intersectio n wit h Rout e 101 . Th e facilit y comprise s amanufacturin g buildin g an da n adjoinin g administratio n offic e building . Th e forme r under
groun dstorag e tank s wer

e locatedbehindth e rea

r nort h corner o f th e manufacturin g part

o f th e facility . Sol amanufacture s hard-resi n ophthalmi c lenses . Th e manufacturin g proces s involve s th e injectio n o f

acatalyzed , thermosettin g resi n int o acavit y betwee n polishe dglas s molds . Th e mol d assembl y i s subsequentl y place di n a n ai r ove n t o cur e th e resin . Th e assembl y i s remove dfro mth e oven , th e cure dresi n lense s remove dfro mth e assembly , an dth e assembl y i s pu t throug h acleanin g proces s before productio n i s repeated . 

### REGIONA L TOPOGRAPH Y Th e topograph y o f

th e area , includin g th e sit e itself , gentl y slope s at arat e o f 5 0 fee t pe r mil e fro m lo w hill s i n th e eas t

toward s th e Petalum aRiver , locate dabou t on e mil e southwes t

o f th e Sol abuilding . Adob e Cree

k i s locate d1,50

0 fee t wes t o f th e Sol abuilding . Adob e Creek intermittentl y flow s i n a north-south direction . 

### HYDROGEOLOG Y Sol aha s conducte dgeologi c investigation s a t th e Site . Sola' s investigation s hav e reveale dtha t th e depositional sequenc e o f sediment s belo w th e surfac e a t th e site consist s o f

acomple x sequenc e o f interbedde dclays , silt s an dsands , wit h lesser amount s o f

gravel . Shallo w sediment s represen t acomple x sequenc e o f

alluvial deposits . At

depth s belo w th e surfac e o f approximatel y 80-10

0 feet , thicke r

cla y interval s wer

e encountere dwhic h appea r t o b e relativel y continuou s over distance s o f

hundred s o f

feet . Interbedde dwithi n thes e clay interval s ar e silt , sand , an dgrave l interval s o f variou s thicknesses . Thes e deepe r sediment s probabl y represen t comple x depositiona l environment s tha t involv e bot

h alluvia l an d estuarin e deposition . Groundwate r i n shallo w sediment s i n th e site vicinit y i s generall y encountere dat elevation s 9 to 1 2 fee t

belo w groun dsurface . Groundwate r

flow s i n asouth/southwes t directio n toward s th e Petalum aRiver , whic h i s th e mos t likel y poin t

o f discharge . Natura l recharg e occur s at th e bas e o f

th e foothill s t o th e north/northeast . Testin g o f

th e aquife r

wa s conducte di n Octobe r 198 7 b y Sol aunde r

th e directio n o f

th e San Francisc o Regional Wate r

Qualit y Contro l Boar

d(SFRWQCB) . Thi s aquife r i s unconfme dan dha s bee n classifie d b y EP A a s aclas s II A drinkin g wate r sourc e aquifer .

## \ v--:.;w4CT" > CASAGRANDE

PRATES A \ SOL A FACILIT Y

figure 1 : SfT E AN D VICINIT

Y PLA N

SOURCE : U.S . Geologica l Surve y 7. 5 minut e Petalum « Rive r quadrangle , phot o revise d I960 .

### LAN D AN D WATE RUS E Th e facilit y i s locate di n a n are azone dfo r industria l uses . Adjacen t

property t o th e wes t

i s owne d b y Stero Company , amanufacture r o f dishwashers . There ar e residentia l subdivision s approximatel y 30 0 fee t t o th e northwes t

an dther e i s undevelope dlan dt o th e north . Fireman' s Fun dInsurance , th e RUS S Company , an dTega l Corporatio n occup y offic e spac e t o th e eas t o f th e Sol aproperty . Property t o th e south remain s undevelope dan dwa s formerly aprivat e residence . Tw o privat e well s operate dpreviousl y i n th e vicinit y o f th e Sol afacility , th e Ster o industria l wel l (approximatel y 1,00

0 fee t west , downgradien t

o f th e facility ) an dth e Crandel l residentia l wel l (approximatel y 1,50

0 fee t southwest , downgradien t

o f th e facility) . Th e owner s o f thes e tw o well s ar e no w supplie dwit h wate r

fro mth e City o f

Petaluma . I n addition , ther e i s aCity o f Petalum a(Statio n #5 ) municipa l wate r

suppl y well , locate d30 0 fee t north o f th e site an dacity wel l o n th e Sol aproperty tha t ha s neve r been used . I n 1988 , Sol aentere dint o awritte n agreemen t wit h th e City o f

Petaluma . Th e City agreedt o discontinu e us e o f Statio n # 5 wel l t o ensur e tha t th e operatio n o f

th e municipa l wel l doe s no t disrup t th e ongoin g groundwate r

clean-u p operatio n b y drawin g dow n groundwate r elevation s i n th e unconfme daquife r

belo w th e screene dinterval s o f th e extractio n wells . Sol aha s sample dth e Statio n # 5 municipa l wel l o n 1 4 occasion s betwee n 198 6 an d1989 . Analysi s o f

thes e sample s di dno t

reveal th e presenc e o f

an y contaminant s whic h exceede dth e Stat e o r Federa l drinkin g wate r

standards . Sol aals o sample dth e Stero an dCrandel l well s si x time s eac h betwee n 1987 an d1990 an dth e result s di dno t excee dth e Stat e o r

Federal drinkin g wate r

standards .
n . SIT E HISTOR Y AN D ENFORCEMEN T ACTIVITIE S I n May 1982 , Sol aidentifie dlo w level s o f solvent s i n groundwate r

unde r th e Sol aproperty nea

r si x undergroun dsolven t

storag e tanks . Sol ause dthes e si x 1,00 0 gallo n undergroun dtank s t o stor e 1,1,1
- trichloroethan e (1,1, 1 TCA) , acetone , an dmethanol . I n 1985 , Sol aindependentl y remove dth e under
groun dtanks . Th e removal o f th e tank s reportedl y include dth e excavatio n o f grave l back-fil l an dan additional thre e fee t

o f nativ e soil fro mth e side s an dbotto mo f th e tan k excavation . Sol acollecte d2 2 soil sample s fro mth e excavatio n pit . Base do n th e analysi s o f thes e soi l samples , Sol aexcavate dan additiona l tw o fee t

fro mth e eastern wal l o f

th e excavatio n pit . Additiona l sample s take n followin g th e excavatio n indicate dth e presenc e o f volatil e organi c compound s (VOCs) ; however , n o additiona l excavatio n wa s conducted . Sola' s earl y investigatio n als o confirme dtha t groundwate r

at th e site wa s contaminate dwit h VOCs,includin g 1,1,1-TCA , l,l-dichloroethene(l,l-DCE) , l,l-dichloroethane(l,l-DCA),andmeth
ylen e chloride . EP A consider s thes e compound s hazardou s t o huma n healt h an dth e environment . I n 1983 , th e SFRWQC B directe dSol at o investigat e th e groundwate r at th e site . I n 1987 , th e SFRWQC B issue dSol aaCleanu p Orde r #87-03 8 t o construc t

agroundwate r

extractio n an dtreatmen t system . Sol awa s propose dfo r th e Nationa l Prioritie s Lis t (NPL ) i n Jun e 1988 . Sol abega n operatin g it s groundwate r

extractio n an dtreatmen t

syste mi n Augus t

o f tha t same year . Sol acurrentl y discharge s th e treate dgroundwate r

t o Adob e Cree

k unde r aNationa l Pollutio n Dicharg e Eliminatio n Syste m (NPDES ) permi t

fro mth e SFRWQCB .EP A conducte dresearc h t o identif y potentiall y responsibl e partie s (PRPs) , thos e partie s wh o ma y b e liabl e pursuan t

t o CERCLA , fo r

th e investigatio n an dcleanu p o f contaminatio n at

th e site . Sol a wa s th e onl y PR P identifie ddurin g thi s investigation . Genera l an dSpecial Notic e wa s issue dt o Sol a prio r t o negotiations . Sol aha s finance dan dconducte daRemedia l Investigation/Feasibilit y Stud y (RI / FS ) unde r an EP A administrativ e consen t order (docke t #89-22 ) signe di n Octobe r 1989 . Sol aha s pai d pas t cost s an doversigh t

cost s incurre db y EP A throug h Jun e 1990 . Th e Remedial Investigatio n include dsamplin g o f soils , soi l gas , an dgroundwater . Th e Remedia l Investigatio n Report , whic h summarize dthes e activities , wa s submitte db y Sol ao n December 3,1990 . EP A complete dth e Ris k Assessmen t

i n Apri l 1991 . Th e Feasibilit y Stud y wa s submitte db y Sol ao n Jun e 10,1991 . HI . HIGHLIGHT S O F COMMUNIT Y INVOLVEMEN T Th e Community Relation s Plan (CRP ) wa s develope din-hous e b y EPA' s communit y relation s staff, followin g EP A guidance . Consisten t wit h th e recommendation s o f th e CRP , th e Projec t

Manage r briefe dth e Petalum aCity Counci l an dissue dafac t shee t announcin g th e administrativ e consen t orde r an dth e commencemen t

o f th e RI/FS . Th e Cit y Counci l meetin g took plac e o n October

19,1989 . Th e fac t sheet wa s maile dt o are aresident s durin g th e sam e perio dan dgenerate dfe w inquiries . I n Februar

y 1991 , followin g th e completio n o f th e remedia l investigation , EP A issue danothe r fac t shee t summarizin g th e finding s t o th e public . N o response s were receive dfollowin g distributio n o f thi s fac t shee t Th e publi c participatio n requirement s o f CERCL A Sec . 113(k)(2)(B)(i-v ) an d11 7 were me t i n th e remed y selectio n process . I n Jun e 199 1 EP A issue dth e propose dplan . A n announcemen t wa s printe di n th e Sant aRos aPres s Democrat o n Jun e 17,1991 , announcin g th e publi c commen t perio dan d th e publi c meeting . EP A hel dth e publi c meetin g o n Jun e 25,1991 , i n th e Veteran s Memoria l Buildin g i n Petaluma . Californi aDepartmen t o f Health Service s an dfou r member s o f

th e communit y attende d th e meeting . EP A receive donl y on e commen t lette r durin g th e publi c commen t period , whic h officiall y close do n Jul y 16,1991 . Detail s o f communit y involvemen t

activitie s an dresponse s t o publi c comment s o n th e Propose d Plan ar e presente di n th e Responsivenes s Summar y (Attachmen t B) . IV . SCOP

E AN D ROL E O F TH E RESPONS E ACTIO N Interi mcleanu p o f

th e groundwate r

an dth e contaminate dsoi l ha s occurred . Sol aaddresse dth e principa l threat s b y removin g th e undergroun dtank s an dcontaminate dsoil s adjacen t t o th e tanks . Th e residua l exten t

an dconcentratio n o V contaminatio n i n th e soil s d o no t presen t asignifican t

threat , base d o n th e result s o f

th e ris k assessmen t

an dagroundwate r

model .

### Th e action s conducte db y Sol aunde r th e directio n o f

th e SFRWQC B hav e partiall y addresse d th e ris k fro mcontaminate dgroundwate r an dhav e attempte dt o hal t o r reduc e th e spreado f

contaminate d groundwate r

bu t were no t intende dt o b e afina l remedy . Th e selecte dfina l remedy addresse s th e remainin g risk s posedb y th e contaminatio n i n groundwater . Th e remedy wil l eliminat e th e potentia l fo r huma n exposure t o contaminant s throug h th e ingestio n an dinhalatio n o f contaminant s i n th e ground
water . Th e reductio n o f

ris k wil l b e achieve db y th e hydrauli c captur e o f contaminant s i n groundwate r throug h th e us e o f

groundwate r

extractio n wells . Th e existin g syste mwil l b e enhance dwit h tw o ne w shallo w extractio n well s an dtw o dee p extractio n well s (converte dfro mmonitorin g wells) . Groundwa
te r wit h contaminan t

concentration s abov e th e Stat e drinkin g wate r standard s wil l b e pumpe dint o th e extractio n system . Extracte dwater

wil l either

b e treate dwit h th e existin g carbo n filte r syste mat

th e facilit y an d discharge doff-sit e o r

discharge dt o th e City sewag e treatmen t syste mwit h o r

withou t treatment . Th e Cit y o f Petalum aha s an industria l discharg e limi t o f 1 part pe r millio n (ppm ) fo r

total toxi c organics . Monitorin g result s fro mth e extractio n syste mindicat e tha t concentration s i n groundwate r ar e presentl y lo w enoug h t o mee t

thi s standar dwithou t

treatment . There ar e n o additiona l operabl e units , an dn o furthe r actio n i s warrante dfo r

soils . V . SUMMAR Y O F SIT E CHARACTERISTIC S SOI L CONTAMINATIO N I n Jul y 1985 , Sol aindependentl y remove dsi x undergroun dstorag e tanks . Sol acontractor s reporte dtha t

the y observe dn o evidenc e o f leakag e durin g th e tan k

removal , whic h indicate dt o them , th e releas e o f

contaminant s coul dhav e bee n th e resul t o f accidenta l spillage . Th e removal o f

th e tank s include dth e excavatio n o f back-fil l materia l an dapproximatel y 3 fee t o f soi l fro mth e side s an dbotto mo f th e tan k excavation . Sample s wer e take n fro mth e pi t afte r th e excavation . Analytica l result s fo r th e sample s collecte dfro mth e excavatio n pit s reveale dth e presenc e o f acetone , rangin g i n concentration s fro m1. 1 to 5 4 ppm . Concentration s o f 1, 1 DC E were detecte da

t 1 0 part s pe r

billio n (ppb) . A n additiona l tw o fee t o f soi l wa s excavate dfro mth e easter n wal l o f th e pi t wher e th e aceton e wa s detected . I n Jul y 1986 , Sol aindependentl y conducte dasoi l ga s investigatio n . Soil ga s sample s were collecte dfro m4 8 locations . Th e highes t VO C concentratio n wa s 25 0 milligram s per lite r o f 1,1, 1 -TCA . I n Apri l 1990 , EP A require dSol at o collec t an danalyz e sample s o f

sub-surfac e soil s an dsoi l gases . Th e soi l ga s surve y include dsample s fro m4 0 location s at depth s rangin g fro m2 t o 9 feet . Th e result s ar e presente di n Figur e 2 . Th e latera l an dvertica l distributio n o f VOC s an dth e magnitud e o f VO C concentration s detecte di n soi l ga s d o no t currentl y indicat e th e presenc e o f aprincipa l threa t

i n soil .FIGUR E # 

# \ V 

# o 2 : f l 0.00 3 TCA O.OOOO 8 PC E O.O 7 Aceton e

LF- H w TM ir-n
OOO l PC E OO 8 Aceton e 

# c

*Qj£ J ' ' "

onaoo • e- n oT ~ 6 1 OJ03 000 8 OJ0 8

.

^

0

- ".; . I.I-DC A rC A F

t 1 3 I.I-DC A TC A TCE PC E Accton r X \ ,

—X 88 1

c 1 E 

# J S M JS P TCA ' 40it t Bc K '' /

2-r t
' / 0. 4 / , oaa

^ ' / 00003 1 / / otrr i / / / /

*VL. ' •'.'•.'•.'-.' • ^vSx-.** - '•':'•'. • 

# sSii M ^^••i ^ •*m&? 

# / \ / \ / v»1 * > . 1 DC /

fx: A HC K T K Aceton e

_, C



### ^ set o ( — * MANUFACTURIN G BUILDIN G 

# V////////////////////

2-f t X ^ R6THS"TC A > ^ OJDO Aceton e X sc 4 5 ft f - 0.000 6 TC A Oj03 Aceton e

• —Treatmen t syste m are a : X^To^

Jcelone

^^1^,^ j-j t b^otidf ' TC A 60 2 " -TC A T"; W •'i^^^pw^.^^ i OuOB Aceton e """ ^ Aceton e /

Ot a Aceton e " " -*ivi i '• ' • ^ f / • ' . . OLO 2 PI1 3 ; ^ ^ / T .f t i - y:'- : , 0.00 1 TC B ^ ^ / •& - j.j.rjc B 0.00 3 PC E - ^ 3 A,, ! X^ ° 0 * MW

_. / 0. 1 A«tOne ; 

# /<//< x '/////

/ " PLWIATW H

' / S / S ^ S f X Sn^-gas utmpfin g lacfllb n

0 Ground-wate rmonitorin g A EnncSo n M l beate n y.v.--. - •• : ••<-.. • -a-ft . »Jt , Dept h I n tee t OJ00 8 a TC A

' Chemical compound 1.1-DC E - 1.1-Dichloraethen e TC A - Trichbroetnan e 1.1-DC A • 1.1-Dichbreethan e PC E • Teltadilorwlhen e F l 1 3 - Trichbroltilluoroethan e TNote : 0.0000 3 t o 0. 1 (}ig^) . Chemicals oatacla

d i n iiiiUuii t ojx m PCE oo a .Aceton e 0 0 ai rcample s (jig/I) . n Aceton e 0.2 . 0. 1 TCA 0.0002 . 0.000 1 4/ 3 Aceton e 0.06 , 0.08 PC E 0.0004 , 0.0000 8 TC A0.0002 . 0.00 4 4/ 4 TC A 0.000

2 PC E 0.00004 Aceton e 0.0 6 4/ 5 TC A 0.000

5 PC E 0.0000

4 TBB~ ~ OJDOO S aoaa d OjO B .I,1-OC A TC A PC E Acctoh e Forme rundergroun d

tank s locatio n vss r rii s TC A ..•' ; oaoo s TC

B 0.000 8 I"C E OJC a Acetbri e oa t TCA 0X00 4 TC E PCB. i -ft"": " -. —, tC A oxuoa e PC K D M . Acetone 0.00 3 TCA o.oooo e O.O Z Aceton e oM " TC A OJOOOO B PC E O M Aceton e

0 W-1 6 2f tV-f

t TC A : ."••• ; <OJ008 9 B 1.1DCE " <o m a I.I-DC A <OJOO M oa

t TC K I.I-DC A .TCA Aceton e S i "". ' 1,1-DC A a i TC A aaoa PC E o m m a aoooa TCA, : TCB oaat aPC E - ^ 0. 1 Acetdri* : 0. 4 f 11 3 0.0 1 TCA O.OO J TCE O.O2 PCE Acetone X s " " ta r ivsr ~ i.i-oc A OJJ I OuOO B TC

A at O. 1 Aceton e 4-f t 0.00 2 TCA O.OOOO8 PC B <a008 1 4 t.l-DC E O B 9 , I.I-DC A ao 2 ; a TC A <aooo 4 0.000

4 TCB o.oooo s o.ooaPCE O. 4 F11 3 O. S TCA 0.00 6 TCE 0.00 4 PC E O. 1 Aceton e o. e I.I.DC E .... . OO J TCA ojooo a re s OJOOO Aceton e 0.0 3 0.0

3 I.I-DC A O.O B 0.0

3 TC A O.OO5 O.O04 TC E ttOO3 0.00 1 PC E ' <aoo i 0.0

4 Ft 1 3 CHEMICA L CONCENTRATION S DETECTE D I N SOIL-GA S SAMPLE S (ng/L) , APRI L 199 0Sol acollecte dsoil sample s fro msi x soi l boring s near th e forme r

locatio n o f

th e storag e tanks . 1,1-DCE wa s detecte dat amaximu mconcentratio n o f Slppb . EPA require dSol ato us e acontaminan t transpor t model to determin e whethe r th e contaminate d soil woul dfurthe r

contaminat e th e groundwater . Th e result s o f th e mode l indicate dthes e soil s d o no t pos e aprincipa l threat

o f furthe r contaminatin g groundwater . GROUNDWATE R Sol aconducte dhydrogeologi c investigation s at th e site . Figur e # 3 provide s asit e diagra m locatin g al l sit

e wells . Th e aquife r

beneat h th e Sol afacility , a s describe dearlier , i s unconfme dan dflow s i n asouth/southwes t

direction . VOC-contaminate dgroundwate r extend s fro mbehin dth e Sol abuildin g (wher e th e undergroun dtank s were formerl y located ) t o th e southwes t corne r o f th e Sol aproperty . Th e focus o f th e groundwate r

investigatio n wa s t o asses s th e exten t o f contaminatio n outsid e th e zon e o f captur e o f th e extractio n syste mconstructe dunde r th e 1987 SFRWQC B Order . I n 1990, Sol ainstalle dnin e additiona l monitorin g wells . Sample s take n fro mthes e an dexistin g groundwate r

monitorin g well s confirme dtha t th e VOC-contaminate dgroundwate r (a t concentration s abov e clean-u p standards ) i s largel y limite dt o th e Sol aproperty (see Figur e #4) . Thes e well s (LF-2 1 throug h LF-28 ) were installed :

t o confir mdowngradien t

latera l an dvertica l exten t o f VOC-contaminate dgroundwater ; an d t o evaluat e th e distributio n o f VOC-affecte dgroundwate r i n th e deep sedimen t

interval s tappe db y th e City o f

Petalum a(Statio n #5 ) municipa l well . Wate r qualit y dat afro mthes e ne w well s achieve dthes e objectives . Th e primary VOC s detecte d i n groundwate r

sample s fro mmonitorin g well s at th e sit e ar e 1, 1 -DCA ; 1, 1 -DCE ; 1,1, 1 -TCA ; an dFreo n 113 . Th e highes t

concentration s o f

th e primary VOC s hav e bee n detecte di n groundwate r sample s collecte dfro mshallo w wel l W14 , whic h i s locate ddowngradien t o f th e vicinit y o f

th e forme r

storag e tanks . Wate r

qualit y dat afro mwell s locate do n th e downgradien t edg e o f th e Sol aproperty (W33 , LF
25 , LF-2 6 an dLF-28 ) indicat e tha t th e latera l exten t o f VOC-contaminate dgroundwate r withi n th e Sol a propert y i s at o r belo w th e clean-u p standards . Figur e #4 show s th e distributio n o f VOC-contaminate d groundwate r

at shallow , intermediate , an ddeepe r intervals . Th e VOC-contaminate dgroundwate r i n deepe r interval s doe s no t

mee t clean-u p standard s i n well s LF-1 7 an dLF-1 3 an di s no t withi n th e captur e o f th e curren t

extractio n system . DAT A QUALIT Y EP A ha s collecte dspli t

sample s an dindependentl y analyze dthes e a s apart o f oversigh t activities . EP A als o ha da n independen t contracto r

validat e thi s data . Qualit y contro l criteri awere me t fo r 98 % o f th e data . EP A dat aan ddat acollecte db y Sol aare i n goo dagreement . Th e relativ e percen t difference , an indicatio n o f precision , i s les s tha n 50 % fo r th e 1 5 sampl e pair s availabl e fo r comparison . EP A spli t dat arepresent s 20 % o f th e tota l dat ause di n th e groundwate r calculation s i n th e ris k assessment .STER O \ / f

/ STER O WEL L

1/-2 7 - ROA D

(APPROXIMAT E ODH-2 * LOCATION) ,PZ 9 PZ 6 C A 0 £R LANE [7LF-2 8 .LF- 6 

## ff^B-rjzr?- E-8« * -8« ^ LF- 5 LF^I S ,W3 1

'PZ 7 LF-1 8

PZ 3 W3 2

, PZ1 1 PZ1 0

W22

. W3 3 «LF- 2
_W2 1 LF- 3

0 Wt 9

W2 4 »*2 6

E- 5 ,PZ 5 PZ2 , M E- 6 • o W2 5

,WI 8 T

-i i L . 

### t " -FORME R STORAG E

TANK S LOCATIO N

MAI N FACILIT Y



### - B ,W1 7 STORAG E BLD G EXPLANATIO N o Shafc

* (u p t o appro . 3 0 b*l ) inonflOni Q WO

T

• (ntamwU * (1 9 t o «ppnn . 6

0 monitorin g m l

• Dwp(H5toipprai . looted ) A On^

r(u p l o «pproi . 200 hoi ) monilonfi g wef l

• DMp9

* («pproi . >20

0 INI ) monitorin g m l PtaofMl * (
» EitadkmiM l DH-2. 0 ShttowmonnorhgwribBUMb y Donald Hwog * Anocfat m (Sou m o l DH-ZiN l locatio n fro m *Em<ronimn M St e Amssiram . Lriwvife Busines s Pot . P«UluM . Cdftxnla' , prapait d lo rOOonml Ifophn s • Rartnws , Se n Ffsnosco , Cflfiiorni s b yOora H Hgrtog « Assodales , Inc . Sant a Ron . California) .
• " Ftndn g

IS O TOT

SIT E PLA NPETALUM A STATIO N 5 an rWEL L EXPLANATIO N Shallo w (u p t o appnn . 90 loci ) monitorin g wd Intermedia

* (u p t o appro . 60 leel ) monitorin g wed Deep (o p t

o appnn . 10

0 fed) fnonrtorin g wel l Deepe r(u p l o appro* . 20 0 feel ) fnQndonnt j we l Deepe d (approi . >20

0 led ) ntonBorin g wef l Estimate d Iml

t o l snatow-dept h o/oundwate rcapture Shalow-dept h groundwate f greate r tha n MCL' s tntermedate-depr h roundwate r greate rtha n MCL' s Dee p an d deeper-dept h groundwate r greate rtha n MCU' s Fendn g

Source : Levine-Fricke . 199 0 VO C CONCENTRATION S GREATE R THA N MCL' a I N SHALLOW , INTERMEDIATE . DEEP , AN D DEEPER-DEPT H QROUNDWATE R

APRI L AN D AUGUS

T 199 0 CWHH/U RDO28373.ES.E Z

### VI . SUMMAR Y O F SIT E RISK S

HUMA N HEALT H RISK S Th e purpos e o f

th e Ris k Assessmen t

wa s t o evaluat e th e publi c healt h an denvironmenta l risk s posedb y VOC s detecte di n groundwater , soil , an dsoil-ga s at th e Sol asite . Th e Ris k

Assessmen t

Repor t wa s complete db y EPA' s contracto r i n Apri l 1991 . Twelv e VOC s at th e site were identifie da s chemi
cal s o f potentia l concern . Th e twelv e chemical s o f potentia l concer

n are presente dalon g wit h thei r respectiv e lexicologica

l dat ai n Tabl e A . Th e exposure assessmen

t evaluate dpotentia l exposur e pathway s fo r th e chemical s o f

potential concer n i n groundwater , soil , an dsoil gas . Th e Ris k Assessmen t

assume s th e maximu mexposure scenario . Th e exposure scenari o assume s residentia l us e o f th e groundwater . Pathway s o f exposur e includ e groundwate r

a s adrinkin g water

sourc e an dVOC s transporte dfro mgroundwate r o r soi l int o househol dai r

(eg. , fro mshowerin g an dothe r domesti c use s o f

water o r soil ga s tha t

woul dsea p directl y int o buildings) . Route s o f exposure includ e ingestio n o f drinkin g water , dermal contact , an dinhalatio n o f VOCs . Th e exposure assumption s use di n th e Ris k Assessmen t

ar e presente di n Tabl e B . Th e concentration s use dt o calculat e ris k fo r soi l ga s exposur e i s base do n amaximu mconcentration . Th e concentration s use dt o calculat e ris k fo r groundwate r

exposur e i s base do n th e 95 % uppe r confidenc e limi t o n th e mean concentration . Th e lexicological assessmen t divide dth e twelv e chemical s o f concern b y thei r

carcinogeni c o r non-carcinogeni c effects . Si x chemical s o f concern were classifie da s known , probable , o r possibl e huma n carcinogens . Th e potentia l fo r carcinogeni c effect s wa s evaluate db y estimatin g exces s lifetim e cancer risk . Non-carcinogeni c ris k wa s assesse db y comparin g th e estimate ddail y intak e o f achemica l t o th e EPA-estimate dsaf

e leve l o f dail y exposure , o r

referenc e dose . Soi l Gas/Ai r

Risks : EP A estimate dpotentia l healt h risk s associate dwit h soi l ga s contaminatio n at th e Sol aproperty base do n diffusio n o f soi l ga s int o th e ai r

o f abuildin g buil t

ove r th e are ao f

soi l an d groundwate r

contamination . O f

th e twelv e chemical s o f

potentia l concern , te n were detecte di n soi l gas . Th e te n chemical s o f

potentia l concern i n soi l ga s wer e use dt o calculat e th e ris k pose db y soi l ga s contaminantio n at

th e site . Th e te n chemical s o f potentia l concern fo r

soil ga s ar e presente di n Tabl e C alon g wit h th e concentration s use dt o calculat e th e risk , th e individua l cancer ris k associate dwit heac h chemical at

th e concentratio n detected , an dth e non-carcinogeni c risk . Th e exces s lifetim e cance r ris k fo r exposure to soi

l ga s i n air i s 9x10-6( 9 person s ou t

o f 1,000,00 0 people) , a s presente di n Tabl e C . Th e non-carcinogeni c health risk s estimate db y th e Hazar dInde x ratin g indicate s tha t n o advers e healt h effect s ar e expected . I n addition , Sol ai s an activ e manufacturin g facilit y zone dfo r industria l use . Groundwate r

Risks : Th e Ris k

Assessmen t

provide s an estimat e o f

carcinogeni c an dnon-car cinogeni c effect s fro mth e domesti c us e o f groundwate r

at th e Sol asite . O f

th e 1 2 chemical s o f

potentia l concern , fou r

contaminant s were detecte di n groundwater . Th e fou r chemical s o f

potentia l concern an d th e estimate dris k

fo r groundw*ater

ar e include di n Tabl e D .



### 1 2TABL E A

Chemica l Aceton e Butanon e 1,1-Dichloroethan e 1,2-Dichloroclhan e 1,1-DicHfcroelhen e Freonll 3 4-Meihyl-2-pentanon e Telrachlomelhen e Toluen e 1,1,1-Trichloroelhan c 1 , 1,2-Trichloroelhan e Trichloroethen e Systemi c Toxlcll y (mg/kR/day) Ora l RI D 0. 1

- - 0. 1

- - 0.00 9 30 0.0 5 0.0 1 0. 3 0.0 9 0.00 4

- - Reference

IRI S

- - HEAS T

- - IRI S IRI S IRI S IRI S IRI S IRI S IRI S

- - Inhalatio n RI D

- -

- - O. I

- -

- -

- - 0.0 2

- - 0.5 7 0. 3

- -

- - Referenc e

- -

- - HEAS T

- -

- -

- - HEAS T

- - HEAS T HEAS T

- -

- - Chemical s o f Concer n Carcinogeni c Potenc y (mg/kg/day)- 1 Ora l Slop

e Facto r

- -

- -

- - 0.09 1 0. 6

- -

- - 0.05 1

- -

- 0.05 7 0.01 1 Weigh t of

Evidence "

- -

- • C B 2 C

- -

- - B 2

- -

- - C B 2 Referenc

e

- -

- - IRI S IRI S IRI S

- -

- - HEAS T

- -

- - IRI S HEAS T Inhalatio n Slope Facto r

- -

- -

- 0.09 1 1.2

-

- - 0.001 8

-

- - 0.05 7 0.01 7 Weight o f Evidence*

- -

- C B2 C

- -

- B 2

-

- - C B 2 KCIVFMIC C «

- - IRI S IRI S IRI S

- -

- HEAS T

- -

- IRI S HEAS T "Grou p B : Probabl e huma n carcinogen . Sufficien t evidenc e i n animal s an d inadequat e o rn o evidenc e i n humans . Grou p C : Passibl e huma n carcinogen . Limite d evidenc e o f carcinogenicil y i n animal s i n th e absence o f huma n data . Notes : HEAST Healt h Effect s Assessmen t Summar yTable , U.S . EP

A 1990b . IRI S Integrate d Ris k Informatio n System , U.S . EPA , 1990a . Informatio n no

t availabl eTh e majo r contributo r

to bot h estimate dcance r

an dnon-cance r

risk s i s 1, 1 DCE . Onl y 1, 1 DC E ha s anumeri c facto r

tha t can b e use dt o calculat e cance r risk . Th e exces s lifetim e cancer ris k presente d b y us e o f on-site contaminate dgroundwate r fo r drinkin g wate r

i s 1 x 10-4 ( 1 perso n ou t

o f 10,00 0 people) . Th e non-carcinogeni c ris k estimat e fo r contaminate dgroundwate r indicate s tha t

n o advers e non carcinogeni c healt

h effect s are expected . Th e calculate dVO C concentration s i n groundwate r were basedo n th e averag e wate r quality dat a fro m2 8 monitorin g wells . Th e calculate dconcentratio n fo r 1, 1 DC E wa s 6 . Ippb , whic h i s clos e to th e clean-up standardan dreflect s approximatel y th e sam e amoun t o f ris k a s th e clean-u p standard . Th e estimate dris k

fo r 1, 1 DC E a

t th e clean-u p standardo f

6 pp b i s als o 1x10-4 . ENVIRONMENTAL RIS K A n Ecologica

l Assessmen t

wa s prepare da s apan o f th e Ris k Assessment . Th e Ecologica l Assessment

focuse do n Adob e Creek . Adob e Cree k i s th e closes t

surfac e wate r

bod y an di s th e sit

e o f aloca l projec t t o reintroduc e anadromou s steelheadtrou t t o th e creek . Wate r qualit y sample s fro mgroundwate r monitorin g well s installe dbetwee n th e Sol aproperty an dAdob e Cree

k hav e no t detecte dan y contaminants , indicatin g tha t discharg e o f

contaminant s t o surfac e wate r

ha s no t occurred . I n th e absenc e o f th e curren t

extractio n system , groundwate r fro mth e Sol afacility woul dflo w i n th e directio n o f Adob e Creek ; however , contaminant s detecte di n ground
wate r at th e sit e ar e belo w thei r

correspondin g federal surfac e wate r qualit y criteri afo r

th e protectio n o f aquati c life . SUMMAR Y Release s o f

hazardou s substance s fro mth e sit e presente dth e potentia l fo r a n imminen t

an d substantia l endangermen t t o publi c health , welfar e an dth e environment . Interi mpumpin g an dtreatmen t o f groundwate r

an dremoval o f

tank s an dcontaminate dsoi l ha s reduce dsite risks ; however , groundwa
te r beneath th e site stil l exceed s drinkin g wate r standard s an dwarrant s remedial action . TABL E B 

### Assumption s use di n Future-Us e Scenario s Paramete r Ingestio n Rat e Inhalatio n Rat e Bod y Weigh t Exposur e Frequenc y Exposur e Duratio n Year s i n Lifetim e Intak e Value * 1 liter/da y (child ) 2 liter/da y (adult ) 2 0 m 3 

### /day (adult ) 1 0 k g (child ) 7 0 k g (adult ) 36 5 days/yea

r 3 0 year s 25,55 0 day s (7 0 years ) "Source : U.S . EPA , 1989a , 1989b , and1989c . 1 4TABL E C 

### Ris k Characterization-Ai r

Pathwa y Chemica l Aceton e 1 , 1-Dichloroethan e 1,2-Dichloroethan e 1,1-Dichloroethen e Freo n 11 3 Tetrachloroethen e Toluen e 1,1 , 1-Trichloroethan e 1 , 1,2-Trichloroethan e Trichloroethen e Tota l Ris k Ai r



### Concentration " (lig/1 ) 4. 0 x 

### 10'

7 

### 9. 9 x 10 * 5. 9 x 

### 10'

7 

### 5. 8 x 1 0 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 

### Exces s Lifetim e

Cance r Ris k Estimat e



### — ~ 6. 6 x 1 0 9 

### 8. 5 x 10 *



### — 8. 8 x 

### 10' 1 2



### —

— 1. 7 x 

### 10- 8 

### 1. 6 x 1 0 1 0 

### 9 x 10 * 

### Hazar dInde x

1. 1 x 10 * 2. 8 x 

### 10'

5



### — 1. 6 x 1 0 3 

### 6. 2 x 

### ID' 9 

### 1. 1 x 10 * 2. 3 x 1 0 7 

### 4. 3 x 10 * 1. 9 x 

### 10-4



### — 0.002 a 

### Maximu mconcentration s

TABL E D



### Ris k Characterization-Groundwate r Pathwa y Chemica l 1 , 1 - D ichloroethan e 1,1-Dichloroethen e Freo n 11 3 1,1, 1 -Trichloroethan e Tota l Ris k Groundwate r

Concentration " (mg/1 ) 0.001 1 0.006 1 0.0006 3 0.0029 Cancer

Ris k Estimate 1 

### *



### — 1.4 

### x 1Q-*



### --



### — 

### IxlO" 1 

### Hazar dInde x

0.002 2 0.1 4 0.000004 2 0.004 2 

### 0. 1 a 

### 9 5 percen t

uppe r confidenc e limi t

o n mea n concentratio n b 

### lngestio n an dinhalatio n route s summe dtogether . Th e hazar dinde x i s base do n achil dexposur e scenario .
1 5

### VII . DESCRIPTIO N O F ALTERNATIVE S

Thi s sectio n wil l describ e alternative s develope di n th e Feasibilit y Study . Th e fiv e extractio n alternative s wer e evaluate dan dcompare dt o th e nin e criteri arequire db y th e NC P (4 0 CF RSec . 300.430(e)(9)) . Th e nin e criteri aare : overal l protectio n o f huma n health an dth e environment ; complianc e wit h applicable , o r relevan t an dappropriat e requirement s (ARARs) ; long-termeffective
nes s an dpermanence ; reductio n o f toxicity , mobility , o r

volum e throug h treatment ; short-term effectiveness ; implementability ; cost ; stat e acceptance ; an dcommunit y acceptance . Th e nin e criteri a ar e describe di n more detai l i n Par t VII I o f thi s decisio n document , entitle dSummar y o f Comparativ e Analysi s o f

Alternatives . Eac h on e o f

th e alternative s i n th e Feasibilit y Study , wit hth e exceptio n o f th e no-actio n alternative , complie s wit hARAR s fo r th e site . T o compl y wit hARARs , a n alternativ e mus t mee t al l substantiv e Federa

l an dStat e environmenta l law s an dregulations . Th e groundwate r

contaminatio n a t

th e Sol asit e i s i n agroundwate r aquife r tha t ha s bee n designate da s asourc e o f

drinkin g wate r

an dha s actuall y bee n prove n t o b e i n th e sam e unconfine d aquife r use db y th e Cit y o f

Petalum amunicipa l wel l (statio n # 5 well) . Fo r thes e reasons , groundwate r mus t b e restore dt o Stat e an dFedera l drinkin g wate r

standards . Th e drinkin g wate r standard s o r

clean
u p standard s fo r

th e fou r contaminant s identifie di n groundwate r ar e presente di n Tabl e E . Th e Primar y VOC s i n Groun dWate r

Chemical 1, 1 DCE 1, 1 DC A 

### 1,1, 1 TC A 

### Freo n 1 1 3 1990 Maximu m

Concentratio n (ppb ) Shallo w Dee p 

### 1,40 0 2 2 28 0 1 22 0 1 0 9 2 

### Tabl e E an dClean-u p Standard s Drinkin g Wate r Standard s (ppb ) Stat e Federal 6 7 5 200 200 

### 1,200 - - 

### Clean-u p

Standard s (ppb )
6 5 20 0 

### 1,20 0 alternative s describe dbelow , excep t th e no-actio n alternative , ar e designe dt o mee t thes e standard s i n th e aquife r

over differen t restoratio n tim e periods . Attainmen t

o f thes e level s i n th e aquife r

wil l b e protectiv e o f

huma n health an dth e environment . However , EP A recentl y studie dth e effectivenes s o f groundwate r

extractio n system s i n achievin g specifie dgoal s an dfoun dtha t i t i s ofte n difficul t

t o predic t

th e ultimat e concentratio n t o whic h contaminant s i n th e groundwate r may b e reduced . Nevertheless , th e study verifie dtha t groundwate r extractio n i s a n effectiv e cleanu p measur e an dca n achiev e significan t mas s removal o f

contaminants . Th e remedial alternative s describe di n thi s sectio n ar e al l base do n extractio n systems . Th e Agenc y 1 6believe s i t i s technicall y feasibl e t o achiev e th e cleanu p standard s i n th e groundwate r usin g extractio n systems . Afte r th e contaminate dgroundwate r i s extracte di t

may b e discharge dt o asurfac e wate r bod y o r t o th e loca

l sewer system . Thes e discharg e option s appl y t o al l o f th e alternative s wit h th e exceptio n o f th e no-actio n alternative . I f th e wate r

i s discharge doff-sit e t o Adob e Cree k i t mus t b e treate dwit h th e activate dcarbo n filte r syste mat

th e facility . Alternatively , th e wate r may b e discharge dt o th e city sewag e treatmen t facility . Th e City o f

Petalum aha s an industria l discharg e limi t o f 1 pan pe r

millio n fo r

tota l toxi c organics . Monitorin g result s fro mth e extractio n syste mindicat e tha t contaminan t

concentration s i n groundwate r

ar e presentl y lo w enoug h t o meet thi s standar dwithou t

treatment . Eac h alternativ e wil l require periodi c groundwate r monitorin g t o determin e it s effectivenes s an d t o verif y achievemen t

o f th e cleanu p standards . Th e specifi c groundwate r monitorin g progra

mwil l b e define dmor

e precisel y durin g Remedial Design/Remedia l Action . I f th e carbo n filte r

treatment

syste mi s used , spen t

carbo n mus t

b e handle di n complianc e wit h th e requirement s o f

th e Resourc e Conservatio n an dRecovery Ac t (RCRA ) an dth e Californi aHazardo u s Wast e Contro l La w i f

wast e (i.e . spen t

carbon ) i s store dfo r

more tha n 9 0 day s at

th e site . ALTERNATIV E # 1 - N O ACTIO N Th e NC P require s tha t

ano-actio n alternativ e b e considere dat every site . Th e no-actio n alternativ e serve s primaril y a s apoin t o f compariso n t o othe r

alternatives . Thi s alternativ e i s evaluate d t o determin e th e risk s tha t woul db e pose dt o publi c healt h an dth e environmen t i f n o actio n wer e taken . Wit h thi s alternative , th e existin g groundwate r extractio n treatmen t

syste mwoul db e shu t

down . However , long-termmonitorin g o f th e sit e woul db e necessar y t o monito r

contaminan t

migration . Monitoring , usin g existin g monitorin g wells , ca n b e easil y implemented . Alternativ e # 1 woul drel y o n natura l processe s i n th e groundwate r t o achiev e cleanu p standards . Th e tim e require dfo r natura l processe s t o reduc e contaminan t concentration s t o th e cleanu p standard s i s estimate dt o b e 50 0 years . Th e annua l operatio n an dmaintenanc e (O&M ) cos t fo r alternativ e # 1 woul db e $70,000 . Sinc e th e alternativ e require s "no-action " there woul db e n o capital cost . ALTERNATIV E #2 Alternativ e # 2 i s th e continue doperatio n o f th e curren t

groundwate r

extractio n syste mat

th e curren t rat e o f 25-3 0 gallon s pe r

minut e (gpm) . Th e curren t syste mpump s groundwate r fro meigh t existin g extractio n wells , eac h o f whic h dra w wate r

fro m2 0 t o 3 0 fee t

beneath th e groun dsurface . Calculate dtim e t o achiev e cleanu p standard s fo r thi s remedy i s 25-3 0 years . Thi s alternativ e woul dprovid e captur e fo r contaminante dgroundwate r wit h VO C concentra tion s abov e th e cleanu p standard s i n Tabl e E , nea r th e surfac e o f

th e wate r

tabl e an ddow n t o approximatel y 40-5 0 feet. VOC s hav e bee n foun da t concentration s whic h d o no t mee t thei r respectiv e cleanu p standard s a

t depth s belo w th e capture o f th e curren t

system . Unde r

Alternativ e #2 , thes e con taminant s woul db e lef

t t o degrad e throug h natura l processes . 1 7I f th e water i s discharge doff-sit e t o Adob e Creek i t mus t b e treate dwit h th e activate dcarbo n filte r syste mat

th e facility . Alternatively , th e wate r may b e discharge dt o th e city sewag e treatmen t facility . Th e ne t

presen t valu e cos t

fo r thi s 25-3 0 yea

r projec t woul drang e betwee n $2. 5 an d$2. 7 million . Capita l cost s woul drang e u p t o $8,00 0 (pipin g an dhook-ups) , an dannua l O& M cost s woul db e betwee n $153,16 6 an

d$166,650 . ALTERNATIV E # 3 Alternativ e # 3 i s th e continue doperatio n o f th e curren t

extractio n syste mwit h tw o additiona l shallo w extractio n wells . Thes e well s woul db e place di n an are ao f hig h VO C concentration , reducin g th e estimate dclean-u p time to 15-20 years . Thi s alternativ e woul dprovid e captur e fo r thos e contaminants , at

concentration s whic h d o no t meet th e cleanu p standard s i n Tabl e E , nea r th e surfac e o f

th e wate r tabl e an ddow n t o approximatel y 40-5 0 feet . A s discusse dearlier , VOC s hav e bee n foun di n th e groundwate r whic h d o no t

meet th e clean
u p standard s at

depth s belo w th e captur e o f th e curren t

system . I f th e wate r i s discharge doff-sit e t o Adob e Creek i t mus t b e treate dwit h th e activate dcarbo n filte r syste mat

th e facility . Alternatively , th e wate r ma y b e discharge dt o th e cit y sewag e treatmen t facility . Th e ne t

presen t valu e cos t

fo r thi s alternativ e woul db e betwee n $2. 0 an d$2. 1 million . Capita l cost s rang e fro m$48,400 t o $54,400 , an dannua l O& M cost s rang e fro m$156,81 4 t o $167,350 . ALTERNATIV E #

4 Alternativ e # 4 convert s tw o deep monitorin g well s int o extractio n well s tha t wil l b e intermit
tentl y pumped . Thi s alternativ e woul daddres s th e groundwate r contamination , a t

concentration s whic h d o no t meet th e cleanu p standard s i n Tabl e E , beneat h th e zon e o f captur e o f

th e curren t

extractio n syste m an dwoul drel y o n th e continue doperatio n o f th e extractio n well s i n th e curren t syste mt o captur e th e shallo w contaminants . Th e tim e estimat e t o achiev e clean-u p standard s i s 25-3 0 years . Th e conversio n o f deepe r monitorin g well s t o extractio n well s woul dpreven t an y furthe r

migratio n o f

contaminant s i n th e deepe r portio n o f

th e aquifer . I f th e wate r

i s discharge doff-sit e t o Adob e Creek i t mus t b e treate dwit h th e activate dcarbo n filte r syste mat

th e facility . Alternatively , th e wate r may b e discharge dt o th e city sewag e treatmen t facility . Th e ne t

presen t valu e cos t

fo r thi s alternativ e i s $2. 6 t o $2. 8 million . Capital cost s rang e fro m $28,40 0 t o $34,400 , andannua l O&M cost s rang e fro m$158,85 8 t o $168,650 .



### 1 8ALTERNATIV E # 5

Alternativ e # 5 i s EPA' s selecte dremedy . Alternativ e # 5 combine s th e action s o f Alternative s # 3 an d#4 . Th e tw o additiona l shallo w extractio n wells , i n conjunctio n with th e existin g wells , wil l reduc e th e estimate dtim e require dt o restor e th e shallo w groundwate r t o clean-u p standard s i n 15-20 years . Th e conversio n o f tw o deep monitorin g well s (LF-1 3 an dLF-17 ) t o extractio n well s wil l pre ven t an y furthe r

migratio n o f

contaminant s i n t o th e deeper portio n o f

th e aquifer . I f th e wate r i s discharge doff-sit e t o Adob e Creek i t mus t b e treate dwit h th e activate dcarbo n filte r syste mat

th e facility . Alternatively , th e wate r may b e discharge dt o th e cit y sewag e treatmen t facility . Th e reduce destimate dtim e t o achiev e th e clean-u p standard s als o reduce s th e numbe r o f year s o f O&M . Becaus e o f

th e reduce dlength o f

O&M , th e ultimat e cos t

i s les s tha n alternative s # 3 o r #4 . Th e ne t presen t valu e cos t

o f thi s alternativ e range s betwee n $2. 1 t o $2. 2 million . Capita l cost s woul d b e $74,000 , an dannua l O& M cost s rang e fro m$160,38 8 t o $169,350 . VIII . SUMMAR Y O F COMPARATIV E ANALYSI S O F ALTERNATIVE S Th e remedia

l alternative s develope di n th e F S were analyze di n detai l usin g th e nin e evaluatio n criteri arequire db y th e NCP . Th e resultin g strength s an dweaknesse s o f th e alternative s wer e the n weighe dt o identif

y th e alternativ e providin g th e bes t balanc e amoun g th e nin e criteria . Thes e criteri a are : 1 ) overal l protectio n o f huma n healt h an dth e environment ; 2 ) complianc e wit h applicabl e o r relevan t an dappropriat e requirement s (ARARs) ; 3 ) reductio n o f toxicity , mobility , o r

volum e throug h treatment ; 4 ) long-termeffectivenes s an dpermanence ; 5 ) short-termeffectiveness ; 6 ) implementabil
ity ; 7 ) cost ; 8 ) state acceptance ; an d9 ) communit y acceptance . Th e nin e criteri aan dth e relativ e performanc e o f

th e alternative s i n relatio n t o eac h criterio n an deac h othe r i s summarize dbelow . 

### PROTECTIO

NO F HUMANHEALT

H AN D TH E ENVIRONMENT Overal l protectio n o f

huma n health an dth e environmen t addresse s whethe r

aremedy provide s adequat e protectio n an ddescribe s ho w risk s pose dthroug h eac h pathwa y are eliminated , reduce do r controlle dthroug h treatment , engineerin g controls , o r institutiona l controls . A s th e no-actio n alternativ e (#1 ) doe s no t achiev e th e cleanu p standard s i t wil l n o longe r

b e discussed . Alternative s # 2 throug h # 5 ar e equall y protectiv e o f huma n healt h an dth e environmen t b y eliminatin g o r

reducin g th e ris k

o f exposure t o contaminant s i n groundwater . Alternative s # 2 throug h # 5 us e engineerin g control s i n th e formo f agroundwate r

extractio n syste mt o remov e contaminate d groundwate r

fro mth e aquife r

wher e i t coul db e use dfo r

consumption . COMPLIANC E WITH ARAR S * Pursuan t t o sectio n 121(d)(l ) o f

CERCLA , remedia l action s mus t attai n adegre e o f

clean-u p whic h assure s protectio n o f huma n health an dth e environment . Additionally , remedial action s mus t mee t standards , requirements , limitations , o r criteri atha t

ar e "applicabl e o r

relevan t an dappropriate " (ARARs) . Federa

l ARAR s fo r

an y site includ e requirement s unde r an y federal environmenta l laws . 1 9State ARAR s includ e promulgate drequirement s unde r state environmenta l o r

facility-sitin g law s tha t ar e more stringen t

tha n an y Federa

l ARAR s an dhav e bee n identifie dt o EP A b y th e stat e i n atimel y manner . Applicabl e requirement s ar e thos e clean-u p standards , contro l standards , an dothe r substantiv e environmental protectio n requirements , criteria , o r limitation s promulgate dunde r Federa l o r State law tha t specificall y addres s ahazardou s substance , pollutant, contaminant , remedia l action , locatio n o r other circumstanc e at

aCERCLA site . Relevan t an dappropriate requirement s are define da s thos e cleanu p standard s o f contro l an d other substantiv e environmenta l protectio n requirements , criteria , o r limitation s promulgate dunde r Federa l o r Stat e law that , whil e no t

"applicable " t o ahazardou s substance , pollutant , contaminant , remedia l action , locatio n o r

othe r circumstanc e a

t aCERCL A site , nevertheles s addres s problem s o r situation s sufficientl y simila r t o thos e encountere dat

th e CERCLA site t o indicat e thei r us e i s well-suite d t o th e particula

r site . I f n o ARA Raddresse s aparticular situation , o r

i f an ARA Ri s insufficien t

t o protec t huma n health o r

th e environment , the n non-promulgate dstandards , criteria , guidances , an dadvisorie s (T o B e Considered , or

TBCs ) mus t

b e use dto provid e aprotectiv e remedy . Additionally , respons e action s whic h tak e plac e off-sit e mus t compl y wit h al l laws , administra
tiv e an dsubstantive . Type s o f ARAR s There ar e thre e type s o f

ARARs . Th e firs t

typ e include s "contaminant-specific " requirements . Thes e ARAR s se t

limit s o n concentration s o f specifi c hazardou s substances , pollutants , an dcontami
nant s i n th e environment . Example s o f thi s typ e o f

ARA Rar e ambien t

wate r qualit y criteri aan ddrinkin g wate r standards . Th e secondtyp e o f

ARA Rinclude s location-specifi c requirement s tha t se t restriction s o n certai n type s o f activitie s base do n site characteristics . Thes e includ e restriction s o n activitie s i n wetlands , floodplains , an dhistori c sites . Th e thir dtyp e o f

ARA Rinclude s action-specifi c requirements . Thes e ar e technology-base drestriction s whic h ar e triggere db y th e typ e o f actio n unde r

consideration . Example s o f action-specifi c ARAR s ar e Resourc e Conservatio n an dRecover y Ac t (RCRA ) regulation s fo r wast e treatment , storage , an d disposal . ARAR s ar e identifie do n asite-specifi c basi s fro minformatio n abou t specifi c chemical s at

th e site , specifi c feature s o f

th e sit e location , an daction s tha t are bein g considere da s remedies . Th e followin g section wil l outlin e th e Applicabl e o r Relevan t an dAppropriate Requirement s (ARARs ) an dothe

r informatio n (TBCs ) that

EPA considere dfo r

thi s site . CONTAMINANT-SPECIFI C ARAR s an dTBC s Cleanu p level s ar e se t

at health-base dlevels , reflectin g curren t an dpotentia l us e an dexposure . Fo r systemi c (noncarcinogenic ) toxicants , cleanu p level s represen t tha t amoun t t o whic h human s coul d 20

### b e expose do n adail y basi s withou t unacceptabl e advers e effect s occurrin g durin g thei r lifetime . Fo r carcinogens , cleanu p level s mus t fal l withi n a10- 4 t o 10- 6 ris k rang e (NCP , 4 0 CF R§300.43 0 Th e contaminant
- specifi c ARAR s fo r th e Sol asit

e ar e Federal an dStat e o f

Californi adrinkin g wate r standards . Eac h i s relevan t an dappropriat e t o se t

a s cleanu p standard s at

th e site . A lis t

o f Federal an dState drinkin g wate r

standard s ar e presente di n Tabl e E . Federal Drinkin g Wate r

Standard s Sectio n 141 2 o f

th e Safe Drinkin g Wate r

Ac t (SDWA X 4 2 U.S.C . §300g- l "Nationa l Drinkin g Wate r Regulations" : Nationa l Primary Drinkin g Wate r Regulations . 4 0 CF RPart 141 . Potential drinkin g wate r

regulation s includ e Maximu mContaminan t Level s (MCLs ) fo r specifi c contaminants . MCL s ar e enforceabl e standard s whic h appl y t o specifie dcontaminant s whic h EP A ha s determine dhav e an advers e effec t o n huma n health . MCL s ar e se t at level s tha t

ar e protectiv e o f huma n healt h an dse t

clos e t o Maximu mContaminan t Leve l Goal s (MCLGs) . Unde r th e authorit y o f

th e NC P (4 0 CF R§300.43 0 (f)(5)) , MCLG s se t at level s abov e zero mus t b e attaine db y remedial action s fo r groun do r surfac e wate r

tha t i s currentl y o r

potentiall y asource s o f drinkin g water , wher e th e MCLG s ar e relevan t an dappropriat e unde r

th e circumstance s base do n th e factor s i n NC P (4 0 CF R§300.400 (g)(2)) . Al l o f th e MCLG s whic h ar e applicabl e t o th e Sol asit e ar e les s stringen t

tha n o r equa l t o th e federa l MCLs . Accordingly , th e appropriat e remedia l standardfo r groundwate r

i s th e curren t

federa l o r stat e MCL , whicheve r

i s mos t stringent . Tabl e E compare s th e curren t stat e an dfedera l MCL s fo r th e chemical s o f

concern an didentifie s th e cleanu p standard . State Drinkin g Wate r

Standard s Californi aSaf

e Drinkin g Act . Californi aDomesti c Wate r Qualit y Monitorin g Regulations . CA C Titl e 2 2 Divisio n 4 . Chapte r

1 5 Californi aha s promulgate dMCL s fo r primar y VOC s a s show n i n Tabl e E . EP A ha s chose n th e Californi aMCL s fo r

primar y VOC s a s th e groundwate r cleanu p standar dfo r

th e sit e wher e th e Californi aMCLs , fo r

VOCs , wa s more stringen t tha n federa l MCLs . ACTION-SPECIFI C ARAR s AN D TBC s Treatmen t b y Carbo n Adsorptio n Soli dWast e Disposal Act , a s amende db y Resourc e Conservatio n an dRecovery Ac t 4 2 U.S. C §690 1 e t 

### seq . Us e o f

granular activate dcarbo n (GAC ) fo r remediatio n o f

VOC s can trigge r

requirement s associate dwit h regeneratio n o r disposal o f

th e spen t carbon . I f

th e spen t carbo n i s aliste dwast e o r a 2 1characteristi c waste , i t i s regulate da s ahazardou s wast e unde r RCR A an dCalifornia' s Hazardou s Wast e Contro l Law s (CA C Titl e 2 2 §67520-67525) . Container s use dfo r

storag e o f

hazardou s wast e o n sit

e fo r more tha n 9 0 day s mus t

be : Maintaine di n goodconditio n (4 0 CFR§264.171) ; Compatibl e wit h other

storedwaste s (4 0 CFR§ 264.172) ; Closeddurin g storag e (4 0 CFR§264.173) ; Inspecte dweekl y (4 0 CFR§264.175) ; Place do n asloped , crack-fre e bas e wit h containmen t syste mi n plac e capabl e o f handlin g 1 0 percent o f the fre e liquid s stored(4 0 CF R§264.175) ; Placed5 0 fee t

fro mfacility' s property lin e i f ignitabl e o r

reactiv e (4 0 CFR§264.176) ; Separate db y adik e o r

othe r barrier i f incompatibl e waste s are store dnea r eac h othe r

(4 0 CF R§264.177) ; A t closure , remov e al l hazardou s waste s an dresidue s fro mcontainmen t syste m(4 0 CF R §264.178) ; Storag e o f

banne dwaste s mus t

b e i n accordanc e wit h 4 0 CFR§26 8 (4 0 CFR§268.50) . On-sit e storag e o f

contaminate dcarbo n may trigge r substantiv e requirement s unde r stat e law s (Hazardou s Waste Contro l Law , CA C Titl e 2 2 §§67180-6719 4 an dCA C §67240-67248 ) an dmunicipa l o r county hazardou s materia l ordinances . I f th e spen t carbo n i s ahazardou s waste , constructio n an d monitorin g requirement s fo r storag e facilitie s ma y als o apply . LOCATION-SPECIFI C ARAR s AN D TBC s A sit e characterizatio n wa s conducte dat Sol at o determin e whethe r specia l characteristic s existe da t th e site whic h warrante dlocatio n specifi c requirements . N o location-specifi c requirement s were found . LONG-TER M EFFECTIVENES S AN D PERMANENC E Long-ter meffectivenes s an dpermanenc e refer s t o th e ability o f aremedy t o maintai n reliabl e protectio n o f

huma n healt h an dth e environmen t over time . Thi s criterio n include s th e consideratio n o f residua l ris k

an dth e adequac y an dreliabilit y o f controls . Remedia l alternative s # 2 throug h # 5 al l resul t i n minima l residua l risk . Onc e th e contaminant s i n groundwate r

hav e been reduce dt o th e cleanu p standardconcentratio n th e primary ris k wil l hav e bee n permanentl y reduced . With th e exceptio n o f th e no-actio n alternative , al l o f th e alternative s are expecte d t o attai n clean-u p standard s i n groundwater , thereb y resultin g i n minima l ris k fro mresidua l contami
nant s i n groundwater . However , th e residua l ris k pose db y th e contaminant s at thei r respectiv e cleanu p standard s remains . * Extracte dwate r

wil l eithe r

b e treate dwit h th e existin g activate dcarbo n filte r syste ma t

th e facility an ddischarge doff-sit e t o Adob e Creek o r discharge dt o th e Cit

y sewag e treatmen t

system . I n bot h discharg e options , adequat e treatmen t woul doccur ; eithe r

i n th e existin g carbo n filte r syste mo r i n th e Cit y sewag e treatmen t

system . 

### 2 2REDUCTIO N O FTOXICITY . MOBILITY . O RVOLUM E THROUG H TREATMEN T

Reductio n o f

toxicity , mobility , o r

volum e throug h treatmen t refer s to th e preferenc e fo r a remed y tha t use s treatmen t

t o reduc e health hazards , contaminan t migration , o r

th e quantit y o f contaminant s at

th e site . Al l o f th e alternatives , excep t

th e no-actio n alternativ e emplo y treatment , i n varyin g degrees . Th e discharg e optio n employe dwil l determin e th e typ e an dlocatio n o f treatment ; discharg e to Adob e Cree k wil l require prio r

treatmen t with th e carbo n filte r

system ; whil e discharg e t o th e Petalum asewag e syste mwil l resul t

i n treatmen t

prior t o o r i n th e sewag e treatmen t system . Extracte dwate r

wil l eithe r

b e treate dwit h th e existin g activate dcarbo n filte r syste mat

th e facilit y an d discharge doff-sit e to Adob e Cree k o r discharge dto th e City sewag e treatmen t system . Th e City o f Petalum aha s an industria l discharg e limi t o f 1 part pe r millio n (ppm ) fo r

total toxi c organics . Monitorin g result s fro mth e extractio n syste mindicat e tha t concentration s i n groundwate r ar e presently lo w enoug h t o mee t

thi s standardwithou t

treatment . Eac h o f th e alternatives , excep t

th e no-actio n alternative , i s expecte dt o attai n clean-u p standard s i n groundwater , thereb y resultin g i n minima l ris k fro mcontaminan t

residual s i n groundwater . Spen t carbo n filter s containin g th e contaminant s wil l b e manage di n complianc e wit h ARARs . SHORT-TERM EFFECTIVENES S Short-ter meffectivenes s refer s t o th e perio do f tim e neede dt o complete th e remed y an dt o an y advers e impact s o n huma n healt h an dth e environmen t tha t ma y b e pose ddurin g th e constructio n an d implementatio n o f

th e remedy . Alternative s # 2 throug h # 5 ar e expecte dt o pos e n o unacceptabl e short-termrisk s t o th e communit y o r

worker s durin g constructio n an dimplementation . Installatio n o f th e extractio n well s coul db e complete di n on e t o tw o weeks . Alternative s # 3 o r

# 5 are expecte dto attai n clean-u p standard s i n 1 5 - 2 0 year s becaus e o f thei r highe r extractio n volumes , pumpin g at approximatel y 35-40gpm . Alternative s # 2 o r #4 wil l pum p groundwate r

at an approximat e rat e 25-3 0 gp mresultin g i n an increase dtim e o f 2 5 -3 0 year s t o achiev e th e cleanu p standard s i n th e aquifer . Alternativ e # 2 wil l captur e les s contaminate dgroundwate r tha n other alternative s (# 3 o r

#5 ) an di t woul dleav e deepe

r VOC-affecte dgroundwate r untreate dan duncon trolled . Alternativ e # 3 wil l captur e alarger volum e o f

contaminate dshallo w groundwate r bu t i t woul d leav e th e deepe

r VOC-affecte dgroundwate r untreate dan duncontrolled . Alternativ e #4 wil l reduc e th e mobility o f

deepe r VOC-affecte dgroundwate r b y pumpin g contaminate dmonitorin g well s bu t woul d captur e approximatel y th e same volum e o f shallo w groundwate r

a s Alternativ e #2 . Alternativ e # 5 wil l capture alarger

volum e o f

contaminate dshallo w groundwate r an dals o decreas e th e mobilit y o f deepe r VOC-affecte dgroundwater . *



### 2 3IMPLEMENT ABILIT Y Implementability refer s t o th e technica l an dadministrativ e feasibility o f aremedy , includin g th e availability o f

material s an dservice s neede dt o implemen t th e selectedremedy . I t als o include s coordinatio n o f

Federal , State an dloca

l government s i n cleanu p o f th e site . Al l o f th e alternative s are implementable . Th e installatio n o f extractio n well s involve s wel l know n an dfrequentl y use dmetho dan dmaterials . Th e carbo n filte r

treatmen t syste mha s acurren t

capacity o f

60gp man dwil l no t

hav e t o b e upgrade di f i t i s used . Al l alternative s require groundwate r monitoring . COS T Thi s criteri aexamine s th e estimate dcost s fo r eac h remedia

l alternative . Fo r

comparison , capital cost s an dannua l O& M cost s are use dt o calculat e apresen t worth cos t

fo r eac h alternative . Alternativ e # 2 woul dno t

incu r an y additiona l capita l cos t an dth e annua l O& M expenditur e o n th e syste mwoul db e approximatel y $166,000 . Alternativ e # 2 ha s atotal $2. 7 millio n ne t presen t valu e with treatmen t

an ddischarg e t o th e cree

k o r $2. 5 dischargin g t o th e sewag e treatmen t system . Th e latte r ha s alowe

r net present valu e becaus e o f

aslightl y lowe

r O& M cost . Alternativ e # 3 woul dhav e approximatel y $8,00 0 i n capita l cost s plu s a n approximat e annua l O& M cos t

o f $153,000 . Th e ne t

presen t valu e fo r alternativ e # 3 i s $2. 1 millio n i f treatmen t

occur s on sit e o r $2. 0 millio n i f

dischargin g to th e sewag e treatmen t system . Alternativ e #4 woul drequir e an approximat e capita l cos t o f $46,00 0 an dan approximat e annua l O& M cos t

o f $168,000 . Th e total ne t

presen t valu e i s $2. 8 millio n i f

treate di n th e carbo n filte r syste m o r $2. 6 millio n i f

discharge dt o th e sewag e treatmen t system . Alternativ e # 5 ha s acapita l cos t o f approximatel y $123,000 an dan approximat e annua l O& M cos t o f $169,000 . Th e tota

l ne t presen t valu e i s $2. 2 millio n i f

treatmen t

i n th e carbo n filte r

syste mi s use do r $2. 1 millio n i f

dischargin g int o th e sewag e treatmen t system . STAT E ACCEPTANC E State acceptanc e indicate s whether , base do n it s revie w o f th e RI , FS , an dProposedPlan , th e state i n whic h th e sit

e reside s agree s wit

h th e preferre dalternative . EP A ha s involve dth e SFRWQC B durin g th e developmen t o f th e RI/F S an dselectio n o f th e remedy . SFRWQCB , o n behal f o f th e Stat e o f

California , ha s state dapreference , an dconcur s wit h EPA , o n th e selectio n o f alternativ e # 5 a s th e preferre dremedy .



### 2 4COMMUNIT Y ACCEPTANC E

Community acceptanc e indicate s th e publi c support o f agive n alternative . EP A solicite dinpu t

fro mth e communit y o n th e groundwate r clean-u p alternative s propose dfo r th e Sol aOptica

l Site . Th e publi c di dno t

oppos e th e preferre dalternative . Ther e wa s on e writte n se t

o f comment s receive dfro mon e member o f th e communit y statin g suppor t fo r th e preferre dremedy . A respons e to thi s se t

o f comment s i s provide di n Attachmen t B . IX . SELECTE D REMED Y EP A ha s selectedAlternativ e # 5 a s th e remedy fo r th e site . Thi s remed y addresse s groundwate r a t th e sit e an dconsist s of : groundwate r

monitorin g t o assure captur e o f contaminate dgroundwate r an dt o demonstrat e restoratio n o f

groundwate r

t o cleanu p standard s throughou t th e aquifer , operatio n o f

existin g extractio n well s (8) , constructio n an doperatio n o f tw o (2 ) additional shallo w extractio n wells , conversio n o f

monitorin g well s LF-1 3 an dLF-1 7 to dee p extractio n wells , constructio n an doperation o f additiona l pipin g fo r

th e ne w an dconverte dwells , on-site treatmen t

an ddischarg e off-sit e o r

discharg e t o th e Cit y o f

Petalum asewag e treatmen t system . Th e inten t

o f thi s remedy i s t o restore groundwate r t o it s beneficia l use , whic h fo r thi s site i s drinkin g water . Base do n informatio n obtaine ddurin g th e remedial investigatio n an do n acarefu l analysi s o f

al l remedia

l alternatives , EP A an dth e State o f Californi abeliev e tha t

th e selectedremed y wil l achiev e thi s objective . Th e selectio n o f

thi s remedy i s base do n acomparativ e analysi s o f th e alternative s presente d abov e an dprovide s th e bes t balanc e o f

trade-off s wit h respec t

t o th e nin e evaluatio n criteria . Th e selecte dremed y provide s th e fastes t rout e toward s achievin g th e cleanu p standard s an drestorin g th e groundwate r

t o ful l beneficial use . Th e selecte dremedy include s groundwate r extractio n fo r

a n estimate dperio do f

1 5 to 2 0 years . Thi s groundwate r

extractio n syste mwil l operat e unti l th e cleanu p standard s ar e achieve dan dcontinu
ousl y maintaine dthroughou t th e aquifer . Th e cleanu p standard s are stat e o r federall y promulgate d drinkin g water

standards . Unti l thes e standard s are achieve dan dcontinuousl y maintained , EP A wil l periodically re-evaluat e th e remedy ever y fiv e year s wit h th e firs t

evaluatio n i n Octobe

r 1993 . A t thes e evaluations , i f

availabl e EPA methodolog y i s more accurate , th e risk s o f soil/groundwater

gase s migratin g throug h th e soil int o potential residence s o n th e sit e wil l b e re-evaluated .



### 2 5

### I t may becom

e apparent , durin g implementatio n o r operatio n o f

th e groundwate r

extractio n system , tha t

contaminan t

level s hav e cease dt o declin e an dar e remainin g constan t at level s highe r

tha n th e cleanu p standards . Base do n th e performanc e data , operatio n o f th e extractio n syste mwil l b e adjuste da s warrante di f

s o determine ddurin g th e periodi c EP A evaluations . Fo r example , i t

may b e appropriat e t o discontinu e operatio n o f extractio n well s i n area s wher e cleanu p goal s hav e bee n attained , alternat e pumpin g a t

well s t o eliminat e stagnatio n points , an dpuls e pum p t o allo w aquife r equilibratio n an dencourag e adsorbe dcontaminant s t o partitio n int o groundwate r fo r extraction . Alternativ e # 5 ha s acapita l cos t o f approximatel y $123,00 0 an dha s an approximat e annua l O& M cos t

o f $ 169,000 . Th e total ne t

presen t valu e i s $2. 2 millio n i f

treatmen t i n th e carbo n filte r

syste m i s use do r $2. 1 millio n i f

discharg e i s int o th e sewag e treatmen t system . X . STATUTOR Y DETERMINATION S Th e selecte dremed y i s protectiv e o f huma n healt h an dth e environmen t a s require db y sectio n 12 1 o f CERCLA . Th e selecte dremedial action , whe n complete , shal l compl y wit h applicabl e o r relevan t an dappropriate environmenta l standard s establishe dunde r Federal an dStat e environmenta l laws , unles s astatutory waive r

i s granted . Th e selecte dremed y i s cost-effective , us e permanen t treatmen t technologie s o r

resourc e recover

y technologie s t o th e maximu mexten t practicabl e an dinclude s treatmen t a s aprincipa l element . Th e followin g section s discus s ho w th e selecte dremed y fo r th e Sol a site meet s thes e statutory requirements . PROTECTIO N O FHUMA N HEALT H AN D TH E ENVIRONMEN T Attainmen t

o f clean-u p standard s assure s tha t th e sit e ris k

fall s withi n th e acceptabl e range . Th e cumulativ e sit e ris k

o f 10-4 fall s withi n th e acceptabl e rang e (10- 4 t o 10-e) . Alternative s # 5 use s engineerin g control s i n th e for mo f agroundwate r

extractio n syste mt o remov e contaminate dground
wate r fro mth e aquife r

wher e i t coul db e use dfo r

consumption . Th e extractio n o f VOC-contaminate d groundwate r

wil l significantl y reduc e th e threa t o f exposur e t o residents . Th e implementatio n o f thi s remed y wil l no t

create an y short-termrisk s no r an y negativ e cross-medi aimpacts . ATTAINMEN T O FARAR S Al l ARAR S woul db e me t

b y th e selecte dremedy . Th e selecte dremedy wil l achiev e complianc e wit h chemical-specifi c ARAR S b y extractin g groundwate r wit h contaminan t

concentration s exceedin g th e chemical specifi c cleanu p standards . Action-specifi c ARAR S wil l b e me t b y bot h discharg e options . There ar e n o applicabl e location-specifi c ARARS . COST-EFFECTIVENES S EP A believe s th e selecte dremedy i s cost-effectiv e an dextract s th e contaminate dgroundwate r withi n areasonabl e perio do f time . Th e selecte dremed y fulfill s th e nin e criteri aan dprovide s overal l effectiveness i n relatio n t o it s cost .



### 2 6

### Alternativ e # 5 ha s an capital cos t o f approximatel y $123,000 an dan approximat e annua l O& M cos t o f $169,000 . Th e total ne t

presen t valu e i s $2. 2 millio n i f

discharge dto th e cree

k o r $2. 1 millio n i f dischargin g int o th e sewag e treatmen t system . US E O FPERMANEN T SOLUTION S AN D ALTERNATIV E TREATMEN T TECHNOLOGIE S O R RESOURC E RECOVER Y TECHNOLOGIE S T O TH E MAXIMU M EXTEN T PRACTICABL E Th e selectedremedy represent s th e maximu mexten t t o whic h permanen t

solution s an dtreatmen t technologie s can b e use di n acost-effectiv e manne r fo r th e Sol asite . O f

thos e alternative s tha t

are protectiv e o f

huma n healt h an dth e environmen t an dcompl y wit h ARARS , EP A ha s determine dtha t th e selectedremed y provide s th e bes t balance : i n long-termeffectiveness an dpermanency ; reductio n o f toxicity , mobility an dvolum e throug h treatment ; short-termeffectiveness ; implementability , an dcos t effectiveness ; th e selectedremed y ha s als o gaine dstate an dcommunit y acceptance . PREFERENC E FO RTREATMEN T A S A PRINCIPA L ELEMEN T VOC-contaminate dgroundwate r wil l b e extracted , an dth e VOC s wil l b e treated . Th e treatmen t wil l occur i n th e curren t

on-sit e syste musin g carbo n adsorptio n t o remov e an dconcentrat e th e VOC s o r th e treatmen t

wil l occur

i n th e sewag e treatmen t

syste moperate db y th e Cit y o f Petaluma . Therefore , thi s remed y satisfie s th e statutory preferenc e fo r remedie s tha t

emplo y treatmen t

whic h permanentl y an d significantl y reduce s toxicity , mobility , o r volum e o f

hazardou s substance s a s aprincipa l element .



### 2 7Pag e No. 1

05/13/9 1 ATTACHMENT A

* SOL A OPTICA L US A

IN C KTALUNA , CALIFORNI A ADMINISTRATIV E RECOR D FIL E INDE X

AR # Rol l # Frame * Dat e Autho r Addresse e Subjec t

M t 1 00/00/0 0 Chi pDemares t Nationa l Oceani c 1 Atmospheri c Administratio n Sit e exposur e potential , relate d contaminatio n& NOA

A trus t habitat s & specie s (undated , informatio nfo r RP H Michae l Montgomery/EPA-9 )
AR 2 87/07/2 8 Environmenta l Protectio n Agenc

y- Regio n I X HR S packag e w/attch s (lis t o f references , u/ o referenc e #4 )

AR 3 88/06/2 0 Jerr y Cliffor d Environmenta l Protectio nAgenc y Regio nI X Jame s Cox

Sol a Optica l USA , In c Ltr : Proposa l t o ad dSol a Optica l t o

Nationa l Prioritie s Lis t (NPL )

AR 4 88/08/2 3 Patrici a Shank s McCutchen , Doyle , Brou n & Enersen Stephen tingl e

Environmenta l Protectio n Agenc y- Offic e o f Emergency an d Remedia l Respons e Ltr : Comment s o nEP A proposa l fo r NPL , M/appendice s A- C (SOLA' S statemen t r e Complain t #87-03 , NP L sit e narrativ e & revise dfactua l statement )

AR 5 89/02/2 2 Michae l Chee , Leste r Feldma n C A Regiona l Wate r Qualit y Contro l Board- San Francisc o Bay Complianc e monitorin g rp t u/analytica l result s (RWOC B Orde r #88-093 ) & T L t o Mar k Adams/Sol a Optica l f r Leste r Feldman , 3/30/8 9

AR 6 89/04/0 5 Jerr y Cliffor d Environmenta l Protectio nAgenc y

- Regio nI X Jame s Cox

Sol a Optica l USA , In c Genera l notic e It r w/concurrence s (Dat e

take nf r las t signature )

AR 7 89/04/1 9 s - Michae l Montgomer y Environmenta l Protectio n Agency- Regio n I X Michae l Chee , e t a l

Environmenta l Protectio nAgenc y

- Regio nI X Memo : Reques t comment s on technica l

workplan , announc e meetin g o n 5/1/89 , M/attc h (Statemen t o f work )

A R 8 89/05/0 9 James Co x Jerr y Cliffor d Ltr : Response t o genera l notic e It r o fPag e No. 2

05/13/9 1

• SOL A OPTICA L US A

IN C PETALUMA , CALIFORNI A

— ADMINISTRATIV E RECOR D FIL E INDE X• •

A R* Rol l Fram e # Dat e Autho r Addresse e Subjec t

Sol a Optica l USA . Inc Environmenta l Protectio nAgenc y Regio nI X 4/5/8 9

AR9 89/05/1 6 Jerr y Cliffor d Environmenta l Protectio nAgenc y Regio nI X Nar k Adam s Sol a Optica l USA , In c Specia l notic e It r fo r RI/FS , w/certifie dnai l receipt s #P-918-448 - U2 , H/ O attch s

A R1 0 89/05/3 1 Michae l Montgomer y Mar k Adam s Environmenta l Sol a Optica l USA , Protectio nAgenc y

- In c Regio nI X Ltr : Reques t copie s o f doc s underline d i nreferenc e lis t sent by Sol a Optical , w/ntarginali a

A R1 1 89/06/1 5 Levine-Frick e Sol a Optica l USA , In c Evaluatio no f implemente dinteri m remedia l measure s & proposed fina l remedia l measure s o nsit e A R1 2 89/07/0 7 Debbi e Lowe Environmenta l Protectio nAgenc y Regio nI X Lyn nUoosley , Cit y Counci l Cit y o f Petalum a Ltr : Includ e addresse e o nmailin g lis t &

CR P wil l b e complete di n9/89 , w/rt g sli p(7/12 ) t o Michae l Montgomery/EPA- 9 indicatin g It r t o interviewee s A R1 3 89/07/1 1 Debbi e Lowe Environmenta l Protectio nAgenc y Regio nI X Mar k Adam s Sol a Optica l USA , Inc Ltr : Prepar e communit y relation s pla n afte r interviewin g communit y members , u/rt g sli p(7/12 ) t o Michae l Montgomer y Indicatin g sam

e It r sent t o other s
A R1 4 89/07/1 2 Steve nRitchi e C A Regiona l Wate r Qualit y Contro l Board - San Francisc o Ba y Mar k Adam s Sol a Optica l USA , Inc Ltr : Respons e t o 6/15/8 9 reques t t o rescin d orde r #87-038 , u/mailin g lis t

AR1 5 89/07/1 7 Patrici a Shank s McCutchen , Doyle , Brow n£ Enerse n Alle nZabe l

Environmenta l Protectio nAgenc y Regio nI X Ltr : Good fait hoffe r t o conduc t I financ e RI/F S proposed fo r site , w/appendice s 1 , 4 . w/ o appendi x5 (redacted )Pag e No. 3

05/13/9 1

' SOL A OPTICA L US A

IN C KTALUMA , CALIFORNI A ADHINISTRATIV E RECORD FIL E INDE X

AR* Rol l * Fram e # Dat e Autho r Addresse e Subjec t

A R1 6 89/07/2 4 Michae l Montgomer y Environmenta l Protectio nAgency

- Regio nI X Nar k Adam s Sol a Optica l USA , Inc Ltr : Respons e t o Sol a Optical' s 7/17/8 9 goo d fait hoffe r fo r RI/FS , w/certifie d •ai l receipt s #P-918-tt7-09 1

A R1 7 89/08/ UMichae l Montgomer y Environmenta l Protectio nAgenc y

- Regio nI X Mar k Adam s Sol a Optica l USA , In c Ltr : Conment s o ndraf t remedia l investigatio nfeasibilit y stud y (RI/FS ) workpla no f 8/2/8 9

A R1 8 89/08/1 7 Jerry Clifford , John Rothma n Environmenta l Protectio nAgenc y

- Regio nI X Danie l McGover n Environmenta l Protectio nAgenc y Regio nI X Memo : Reques t fo r 30-da y extensio nt o th e RI/F S negotiatio nmoratoriu m o nsit e

A R1 9 89/08/1 7 Danie l McGover n Environmenta l Protectio nAgenc y Regio nI X Jerr y Clifford , Joh n Rothma n Environmenta l Protectio nAgenc y

- Regio nI X Memo : Approv e 30-da y extensio nt o Sol a Optica l negotiatio nmoratoriu m

A R 2 0 89/08/3 0 Levine-Frick e Sol a Optica l USA , In c Remedia l investigatio nfeasibilit y study (RI/FS ) workplan , w/marginali a
A R2 1 89/09/1 3 Michae l Montgomer y Environmenta l Protectio nAgenc y

- Regio nI X Jef f Zelikso n Environmenta l Protectio nAgenc y Regio nI X Memo : Reques t fo r signatur e o nSol a Optica l sit e consen t orde r t workplan , u/ o encl . u/rt g sli pf r Michae l Montgomer y

t o 5 EP A

staf f
A R2 2 89/09/1 5 Michae l Montgomer y Environmenta l Protectio nAgenc y

- ^Regio nI X Mar k Adam s Sol a Optica l USA , In c Ltr : Technica l scopin g meetin g fo r developmen t o f samplin g & analysi s pla n

A R 2 4 89/10/0 0 Environmenta l Protectio nAgenc y Regio nI X Fac t sheet : EP A sign s agreemen t w/sit e t o continu e investigatio no f groundwate r contaminatio nPag e No. 4

05/13/9 1 SOUOPTICA L US A INC PETALUMA . CALIFORNI A ADMINISTRATIV

E RECOR D FIL E INDE X

AR* Rol l f Frame * Dat e Autho r Addresse e Subjec t

A R 2 3 89/10/0 0 Environmenta l ProtectionAgency Regio nI X Conmunit yrelation s plan (CRP )

AR 25 89/10/0 2 Jef f ZeUkso n Environmenta l Protectio n Agenc

y Regio n I X Richard Kapash

Sol a Optica l USA , Inc Administrativ e consen t orde r fo r RI/F S i n mtte r o f Sol a Optica l USAInc . USEP A docke t «89-2 2

A R 2 6 89/10/0 4 Michae l Montgomer y Environmenta l Protectio n Agency- Regio n I X Mar k Adams

Sol a Optica l USA , Inc Ltr : Notif yaddresse e tha t autho r i s

EPA' s designate d Projec t Coordinato r fo r sit e

A R 2 7 89/10/1 0 Levine-Frick e Sol a Optica l USA , In c Monthl yrp t o f hydrogeologi c

investigation s on sit e during 9/8 9 A R 2 8 89/10/1 1 Mar k Adam s Sol a Optica l USA , Inc Michae l Montgomery

Environmenta l Protectio n Agency- Regio n I X Ltr : Confirmtha t monthl yprogres s rpt s

wil l b e submitte d t o EP Aon/befor e 15t h o f eac h mont h

A R 2 9 89/10/1 6 Cit yCounci l Cit yo f Petal i Transcrip t (partial ) o f EP Apresentation a t 10/16/8 9 Cit yCounci l meeting , u/ o vide o tape , u/T

L t o Michae l Montgomer

y f r Mar k Adams , 11/29/8 9 A R 3 1 89/10/1 6 Michae l Montgomer y Env i ronmenta l Protectio n Agenc

y- Regio n I X Mar k Adams

Sol a Optica l USA . In c TL : Guidanc e o n PR P sampling I analysi s

pla n developmen t & note s f r Ecologica l Assessmen t grou p

A R 3 0 89/10/1 6 Agreemen t between sit e I Cit yo f Petalun a t o shut dow

n statio n 5 & Sola
Cit ywell , reinturs e Cit yfo r purchas e o f substitut e water , w/exhibi t 1 : Cos t A R 3 2 89/11/1 5 Levine-Frick e Sol a Optica l USA , Monthl ystatu s rp t o f RI/F S activitie sPag e No. 5

05/13/9 1 SOL A OPTICA L US A

IN C PETALUMA . CALIFORNI A

— ADMINISTRATIV E RECOR D FIL E INDE X

A R* Rol l * Frame # Dat e Autho r Addresse e Subjec t

In c durin g 10/89 , u/ o figur e 1 A R3 3 89/11/1 5 Nar k Adam s Sol a Optica l USA . In c Michae l Montgomer y Environmenta l Protectio n Agenc

y - Regio n I X TL : Monthl y statu s rp t o f RI/F S activitie s durin g 10/89 prepare d by Levine-Fricke u/attache d distributio n lis t A R 3 4 89/12/1 2 Michae l Montgomer y Environmenta l Protection Agenc

y- Regio n I X Steve Simons , Wate r

Departmen t Cit yo f Petalum

a ROC : Confin e destructio n o f Crandel l wel l & hook-u

p o f Crandel l propertyt o municipa l syste

mo n 8/18/8 9 a t Sola' s expens e A R 3 5 89/12/1 5 Levine-Frick e Sol a Optica l USA , Inc Monthl y statu s rp t o f RI/F S activitie s durin g 11/89 , w/T L t o Michae l Montgomery/EPA- 9 f r Mar k Adams/Sol a Optica l 1 marginali a A R 3 6 89/12/2 9 Patrici a Shank s McCutchen , Doyle , Brow n & Enersen Michae l Montgomer y Environmenta l Protectio n Agency- Regio n I X TL : Draf t samplin g & analysi s pla n (SAP )

I draf t healt h £ safetypla n (HSP ) fo r revie w& commen t

A R3 7 90/01/1 5 Levine-Frick e Sol a Optica l USA , Inc Monthl y statu s rp t o f RI/F S activitie s durin g 12/89 , w/T L t o Michae l Montgomery/EPA- 9 f r Mar k Adams/Sol a Optica l A R 3 8 90/01/2 9 Donal d Dalk e CARegiona l Wate r Qualit yContro l Boar d - San Francisc o Ba

y Michae l Montgomer y

Environmenta l Protectio nAgenc y

- Regio nI X Ltr : Revie w fiel dsamplin g pla ndate d 12/29/8 9 submitte db

y Sol a Optica l I concur u/technica l revie w by CH2 M Hill , M/mailin g lis t

A R 3 9 90/01/2 9 * Michae l Montgomer y Environmenta l Protectio n Agenc y- Regio n I X Mar k Adam s Sol a Optica l USA , In c Ltr : Revie w comment s o ndraf t samplin g & analysi s pla n(SAP ) date d12/29/89 , w/attc h# 1

A R 4 0 90/02/ U Mar k Adams Michae l Montgomer yLtr : Rational e fo r revise d propose dPag e No. 6

05/13/9 1 SOL A OPTICA L US A

IN C PETALIMA , CALIFORNI A

— ADMINISTRATIV E RECOR D FIL E INDE X

A R# Rol l # Frame # Dat e Autho r Addresse e Subjec t

Sol a Optica l USA , In c Environmenta l Protectio nAgenc y Regio nI X •onitoring well s w/na p t T L f r Scot t Seyfried/Levine-Fricke , 2/16/9 0

A R4 1 90/02/1 5 Levine-Frick e Sol a Optica l USA , Inc Monthl y statu s rp t o f RI/F S activitie s durin g 1/9 0
A R4 2 90/02/1 5 Mar k Adams Sol a Optica l USA , In c Michae l Montgomer y Environmenta l Protectio nAgenc y

- Regio nI X TL : Monthl y statu s rp t o f RI/F S activitie s durin g 1/9 0 prepare d b y Levine-Frick e w/attache d distributio n lis t A R 4 3 90/02/2 1 Steven Ritchi e C A Regiona l Wate r Qualit y Contro l Boar d - Sa n Francisc o Bay CRWQC B Orde r 90-03 0 (Rescind sit e cleanu p orde r 87-03 8 adopte d on 4/15/87) , M/T L t o Mar k Adams/Sol a Optical , 3/19/9 0

A R 4 4 90/02/2 6 Levine-Frick e Sol a Optica l USA , In c Qualit y assuranc e projec t pla n (QAPP )

A R 4 5 90/02/2 6 Levine-Frick e Sol a Optica l USA , Healt h& safet y pla n In c A R4 7 90/02/2 6 Mar k Adam s Sol a Optica l USA , In c Michae l Montgomer y Environmenta l Protectio nAgenc y

- Regio nI X TL : Document s comprisin g samplin g & analysi s pla ndate d 2/26/9 0 prepare d b y Levine-Frick e w/attached distributio n lis t A R 4 6 90/02/2 6 Levine-Frick e Sol a Optica l USA , In c Fiel d samplin g pla n hydrogeologi c investigation s A R 4 8 90/03/1 5 * Levine-Frick e Sol a Optica l USA , In c Monthl y statu s rp t o f RI/F S activitie s durin g 2/90 , w/marginali e & T L t o Michae l Montgomery/EPA- 9 f r Mar k Adams/Sol a Optica l A R 4 9 90/03/2 3 CH2 M Hil l Environmenta l Sit e safet y pla nPag e No. 7

05/13/9 1 SOL A OPTICA L US A

IN C PETALUMA , CALIFORNI A

— ADMINISTRATIV E RECOR D FIL E INDE X- -

AR* Rol l # Fram e Dat e Autho r Addresse e Subjec t
Protectio nAgenc y A R5 0 90/03/2 8 Levine-Frick e Environmenta l Protectio nAgenc y Response s t o comment s o nrevise dQAP P b y Keit hEga no f IC F Technology o n2/26/90 , w/T L t o Michae l Montgomery/EPA- 9 f r Har k Adams/Sol a Optical , 4/2/9 0 AR5 1 90/04/0 0 CH2 H Hil l Environmenta l Protectio nAgenc y Regio nI X Fiel dsamplin g pla n

A R5 2 90/04/0 4 Plannin g Researc hEnvironmenta l Cor pEnvironmenta l Protectio nAgency , Management , In c Washingto nD.C . Preliminar y identificatio no f potentia l ARARs , cont # 68-U9-0009 , UA# C0901 9 (TE S 12 , hazardou s wast e sites , zon e IV , region s 8-10 ) A R5 3 90/04/1 6 Levine-Frick e Sol a Optica l USA , In c Monthl y statu s rp t o f RI/F S activitie s durin g 3/90 , w/T L t o Michae l Montgomery/EPA- 9 f r Mar k Adams/Sol a Optica l A R5 4 90/05/1 5 Levine-Frick e Sol a Optica l USA , In c Monthl y statu s rp t o f RI/F S activitie s durin g 4/90 , w/T L t o Michae l Montgomery/EPA- 9 f r Mar k Adams/Sol a Optica l A R5 5 90/06/0 7 Michae l Montgomer y Environmenta l Protectio nAgenc y

- Regio nI X Steve nLuQuire , e t

a l C A Regiona l Wate r Qualit y Contro l Boar d Memo : Reques t comment

s o n attc h do c - preliminar

y identificatio n o f potentia l applicabl e o r relevan t I appropriat e requirement s (ARARs) , w/ o enc l

A R5 6 90/06/1 4 Mar k Adam s *Sot a Optica l USA , In c Michae l Montgomer y

Environmenta l Protectio nAgenc y

- Regio nI X TL : Monthl y statu s rp t o f RI/F S activitie s durin g 5/9 0 (date d6/15/90 ) & tri-annua l groundwate r Monitorin g rp t w/attache ddistributio nlis t A R5 7 90/06/1 5 Levine-Frick e Sol a Optica l USA , In c Combine dmonthl y statu s rp t fo r 5/9 0 I tri-annua l groundwate r monitorin g rp tPag e No. 8

05/13/9 1 SOL A OPTICA L US A

INC PETALUMA , CALIFORNI A ADMINISTRATIV E RECOR D FIL E INDE X

A R Rol l # Frame # Dat e Autho r Addresse e Subjec t
complete ddurin g 4/9 0
A R5 8 90/07/0 2 Levine-Frick e Sol a Optica l USA , In c Soi l investigatio nrp t

A R 5 9 90/07/0 2 Levine-Fricke Sol a Optica l USA , In c Croundwate r investigatio n rpt , M/marginali a
A R6 0 90/07/0 2 Har k Adam s Sol a Optica l USA , In c Hichae l Montgomer y Environmenta l Protectio nAgenc y

- Regio nI X TL : Draf t groundwate r investigatio nrp t o f 7/2/9 0 prepare db

y Levine-Frick e u/attache ddistributio nlis t

A R6 1 90/07/0 2 Mar k Adam s Sol a Optica l USA , In c Michae l Montgomer y Environmenta l Protectio nAgenc y

- Regio nI X TL : Draf t soi l investigatio nrp t prepare dby

Levine-Frick e w/attache d distributio nlis t

A R6 2 90/07/1 8 Levine-Frick e Sol a Optica l USA , In c Monthl y statu s rp t o f RI/F S activitie s durin g 6/90 , w/T L t o Michae l Montgomery/EPA- 9 f r Gregso n TayIor/Lev i ne-F r i ek e A R6 3 90/07/2 6 Jerr y Cliffor d Environmenta l Protectio nAgency Regio nI X Mar k Adam s Sol a Optica l USA , Inc Ltr : Reimbursemen t o f EP A costs , w/concurrences , enc l (redacted ) t nai l receipt s 0P918-448-21 0

A R6 4 90/08/1 5 Levine-Frick e Sol a Optica l USA , Inc Monthl y statu s rp t o f RI/F S activitie s durin g 7/90 , w/T L t o Michae l Mont9omery/EPA-. 9 f r Mar k Adams/Sol a Optica l
A R6 5 90/08/1 5 Levine-Frick e Sol a Optica l USA , In c Respons e t o EP A comment s o ndraf t soi l & grounduate r investigatio nrpts , w/attc h 1 (7/18/9 0 EP A

comment s u/TL) , I T L t o M Montgomer y

f r S Seyfrie dPag e No. 9

05/13/9 1 SOL A OPTICA L US A

IN C PETALUMA , CALIFORNI A ADMINISTRATIV E RECOR D FIL E INDE X

AR# Ro t I # Frame # Dat e Autho r Addresse e Subjec t

A R6 6 90/08/24 Michae l Montgomer y Environmenta l Protectio n Agenc

y- Regio n I X Nark Adams Sol a Optica l USA , Inc Ltr : Con f ir * discussio na t Meetin g o f 7/20/9 0 r e feasibilit y study schedul e

A R6 7 90/OS/2 7 Mar k Adams Sol a Optica l USA , In c Environmenta l Protectio nAgenc y

- SuperfundAccountin g Ltr : Reimburs e EP A site-relate drespons e t oversigh t cost s

A R6 8 90/09/1 4 Levine-Frick e Sol a Optica l USA , In c Monthl y statu s rp t o f RI/F S activitie s durin g 8/90 , w/T L t o Michae l Montgomery/EPA- 9 f r Mar k Adams/Sol a Optica l A R 6 9 90/10/1 2 Levine-Frick e Sol a Optica l USA , In c Combine d monthl ystatu s rp t fo r9/9 0 & semi-annua l groundwate rmonitorin g rp t complete d betwee n 8/2 7 I 9/11/9 0 (Appendi xA )
A R 7 0 90/11/0 1 Michae l Montgomer y Environmenta l Protectio n Agency- Regio n I X Mar k Adam s Sol a Optica l USA , In c Ltr : Comment s o n draf t remedia l

investigatio n rp t o f 10/1/90 , reques t fo r revised yorkplan schedul e i n fina l R I rp t f t meetin

g o n 11/5/9 0
A R7 1 90/11/0 6 Steve Ihnen Environmenta l Protectio nAgenc y Regio nI X Michae l Montgomer y Environmenta l Protectio nAgenc y

- Regio nI X Memo : Classificatio no f grounduater s a t Sol a sit e

A R7 2 90/11/1 5 Levine-Frick e Sol a Optica l USA , In c Monthl ystatu s rp t o f RI/F S activitie s

durin g 10/90 , H/T

L t o Michae l Montgomery/EPA- 9 f r Mar k Adams/Sol a Optica l A R7 3 90/12/0 3 Levine-Frick e Sol a Optica l USA , In c Remedia l investigatio n rp t

A R 7 4 90/12/1 2 Mar k Adam s Michae l Montgomer yLtr : Discus s aspect s o f RI/F S - request* » -* t

Pag e No.1 0

05/13/9 1 SOL A OPTICAL US A

INC PETALUHA , CALIFORNI A

— ADMINISTRATIV E RECOR D FIL E INDE X

A R * Rol l * Fram e * Dat e Autho r Addressee Subject
Sol a Optica l USA , Environmenta l In c Protectio n Agenc y Regio n I X EP A assumption s r e containnant

s o f concern , exposur

e pathway s I calculatio n of exposur

e concentration s A R7 5 90/12/1 3 Levine-Frick e Sol a Optica l USA , In c Monthl y statu s rp t o f RI/F S activitie s durin g 11/90 , w/T L t o Michae l Montgomery/EPA- 9 f r Mar k Adams/Sol a Optica l A R 7 6 91/01/0 2 Michae l Montgomer yMar k Adam s Environmenta l Sol a Optica l USA , Protectio nAgenc y

- In c Regio nI X Ltr : Reques t writte nrespons e t o comment s o

nR I rp t o f 12/3/9 0 (attc h1) , w/ o U A rpt s fo r 9/9 0 & 11/9 0 (attc h2 ) & draf t fac t shee t (attc h3 )
A R 7 7 91/01/1 5 Levine-Frick e Sol a Optica l USA , In c Combined monthl ystatu s rp t fo r12/90 & tri-annua l grounduate rMonitorin g rp t (Appendi xA )
A R7 8 91/02/0 0 Environmenta l Protectio n Agency- Regio n I X Fac t sheet : Remedia l investigatio n complet e - contaminatio nlargel y limite d t o sit e propert y A R 79 91/02/0 8 Levine-Frick e Sol a Optica l USA , In c Detaile d analysi s o f remedia l alternatives , u/narginali a A R8 0 91/02/ ULevine-Frick e Sol a Optica l USA , Inc Monthl y statu s rp t o f RI/F S activitie s durin g 1/9 1
A R8 1 91/02/1 5 Levine-Frick e Sol a Optica l USA , Inc Technica l nem o presentin g result s o f subsurfac e transpor t Modelin g A R8 2 91/04/0 0 CH2 M Hil l Environmenta l Protectio nAgenc y Publi c healt hris k assessment , w/attch s I (draf t technica l nem o - result s o f subsurfac e transpor t Modeling . 2/5/91 ) & I I (VLEAC H model ) A R 8 3 91/05/0 8 Environmenta l Protectio n Agenc y Lis t o f guidanc e document sPag e No. 1

06/14/9 1 SOL A OPTICA L USA , INC . PeteIuna , Californi a ADMINISTRATIV E RECOR D FIL E INDE X Supplemen t No . 1 Al t * Dat e yy/imi/d d Autho r Addresse e Subjec t

A R8 4 91/02/2 8 Michae l Montgomer y

Environmenta l Protectio nAgenc y

• Regio n9 A R8 5 91/03/1 5 Levine-Frick e A R8 6 91/03/1 5 Mar k Adam s

Sol a Optica l USA , Inc A R8 7 91/03/2 5 Mar k Adam s

Sol a Optica l USA , Inc A R8 8 91/03/2 6 Chi pDemares t

Nationa l Oceani c & Atmospheri c Administratio n A R8 9 91/04/1 2 Levine-Frick e

A R9 0 91/04/1 2 Charle s Noye s

C A Regiona l Wate r Qualit y Contro l Boar d- Sa n Francisc o Bay A R9 1 91/05/1 4 Michae l Montgomer y

Environmenta l Protectio nAgenc y

- Regio n9 A R9 2 91/05/1 6 Michae l Montgomer y

Environmenta l Protectio nAgenc y

- Regio n9 A R9 3 91/05/2 1 1C F Technology . In c Mar k Adam s Sol a Optica l USA , In c Sol a Optica l USA , In c Michae l Montgomer y Env i ronmente l Protectio nAgenc y

- Regio n9 Michae l Montgomer y Environmenta l Protectio nAgenc y

- Regio n9 Michae l Montgomer y Environmenta l Protectio nAgenc y

- Regio n9 Sol a Optica l USA , In c
Michae l Montgomer y Environmenta l Protectio nAgenc y

- Regio n9 Mar k Adam s Sol a Optica l USA , Inc Mar k Adam s Sol a Optica l USA , Inc Ltr : Comment s o ndetaile danalysi s o f

remedia l alternative s rp t o f 2/8/91 , w/ o furthe r comment s o ndoc s r e result s o f subsurfac e transpor t modelin g Monthl y statu s rp t o f RI/F S activitie s durin g 2/9 1 Ltr : Installatio no f wel l LF-27 A & T L fo r monthl y

statu s rp t o f RI/F S activitie s durin g 2/9 1 prepare db y Levine-Frick e Ltr : Propos e submitta l dat e o f draf t F S b e thre e calenda r week s afte r receip t o f Baselin e Publi c Healt hEvaluatio n(BPHE ) by Sola , w/marginali a Ltr : Revie w

comment s o necologica l assessmen t portio no f draf t publi c healt hris k assessmen t o f sit e Monthl y statu s rp t o f RI/F S activitie s durin g 3/91 , w/T L t o Michae l Montgomery/EPA- 9 f r Mar k Adams/Sol a Optica l Ltr : N o additiona l comment s o ndraf t cop y o f publi c healt hris k assessmen t (RA ) afte r preliminar y

revie w

Ltr : Preliminar y

comment s o ndraf t F S rp t u/attch s (Draf t It r o f comnent s f r CRUOCB-S F t o M

Montgomer y

o nF S rp t & 7/30/9 0 nem

o r e wate r qualit y

ARAR ) Ltr : Fina l comnent s o ndraf t feasibilit y stud y rp t date d4/15/91 , u/attch s

Dat a validatio nrpt , w/attch s (T L t o Michae l Montgomery/EPA- 9 f r Victori a Taylor/IC F Technolog y

8 5/15/9 1 reques tPag e No. 2

06/U/9 1 SOL A OPTICA L USA , INC . Petaluma , Californi a ADMINISTRATIV E RECOR D FIL E INDE X Supplemen t No . 1
A R* Dat e

yy/mn/d d Autho r Addresse e Subjec t

A R9 4

A R9 5
A R9 6 91/06/0 0 Environmenta l

Protectio nAgenc y Regio n9 91/06/1 0 Levine-Frick e 91/06/1 3 Santiag o Le e

Plannin g Researc h Cor p Environmenta l Management , In c Sol a Optica l USA , In c Environmenta l Protectio nAgenc y

- Offic e o f Wast e Program s Enforcemen t fo r dat a validatio nf r EPA-9 ) Fac t sheet : EP

A announce s proposed pla n fo r cleanu p o nsit e Feasibilit y

stud y rp t Technica l revie w

o f spli t sampl e dat a & PR P data , cont # 68-U9-0009 . UA # C0901 9 (TE S 12 , hazardou s wast e sites , zon e IV , region s 8-10 )

### i . 

### I

SOLA OPTICA L USA , IMC . 8UPERFUN D SIT E Petaluma , Californi a

ADMINISTRATIV E RECOR D FIL E

& 

### INDE X 

### Supplemen t No . 2

Documents : AR97-AR10 0

Jul y2 , 199 1

### SOL A OPTICA L U8A , INC . BDPERPUK D SIT E Petaluma , Californi a Administrativ e Recor d Fil e Inde x Supplemen t Numbe r 2 Thi s Administrative Record Fil e Index , Supplemen t Numbe r 2 , list s the document s adde d t o the Administrative Recor d Fil e fo r the Sol a Optica l USA , Inc . Superfun d Site , Petaluma , California , sinc e Jun e 14 , 199 1 afte r th e compilation o f Supplemen t N o 1 . Th e Inde x present s th

e document s i n ascendin g chronologica l or der , reflectin

g th e organizatio

n o f th

e document s i n th

e file . Eac h documen t ha s bee n assigne d a uniqu e numbe r fo r purpose s o f identification . Thes e ar e indicated a s "ARxx" . Numbering o f the document s i n Supplemen t No . 2 begin s wher e th e Supplemen t No . 1 lef t off ; thu s the firs t documen t i s numbere d "AR97" . Pleas e not e tha t th e origina l Administrativ e Recor d Fil e consist s o f document s # 1 - 8 3 arrange d chronologicall yfro m7/28/8 7 t o 5/8/91 . Supplemen t No . l consist s o f document s IAR8 4 - AR9 6 ar range d chronologicall yfro m2/28/9 1 t o 6/13/91 . Supplemen t No . 2 consist s o f document s #AR9 7 - AR10 0 fro m1/22/9 1 t o 6/14/91 . Be caus e o f th

e overla

p i n dates , i t i s necessar yt o us e al l thre e indice s t o locat e document s fo r a particula r date . Th e document s containe d i n th e Administrativ e Recor d Fil e ar e use d b yth e U.S . Environmenta l Protectio n Agenc yi n identifying appropriat e respons e actio n fo r the Sol a Optica l USA , Inc . Super fun d Site .Pag e No. 1

07/02/9 1 SOL AOPTICAL USA , INC . Petaluroa , Californi a ADMINISTRATIV E RECORD INDE X Supplemen t No . 2
A R # Dat e Autho r Addresse e Subjec t yy/mm/d d
A R 9 7 91/01/2 2 Michae l MontgomeryMar k Adam s Ltr : Respons e t o 12/12/9 0 inquir yr e

Environmenta l Sol a Optica l USA , ris k assessmen t i n progres s & describ e Protectio n Agency- In c eac h exposur e pathwayaddressed i n firs t Regio n 9 ris k assessment (RA ) draf t A R 9 8 91/06/0 4 Michae l Montgomer yMar k Adam s Ltr : Comment s on revise d sectio n 5. 0 o f Environmenta l Sol a Optica l USA , Sol a feasibilit ystud yrp t date d 5/29/9 1 Protectio n Agenc y- In c Regio n 9 A R 9 9 91/06/1 1 Vick i Rose n M Patrici a Memo : Publi c commen t perio d - 6/17
-

Environmenta l Hilligoss , Mayor , e t 7/16/9 1 & publi c meetin g wil l b e o n 6/2 5 Protectio n Agenc y- a l a t Veteran s Memoria l Building , w/attc h Regio n 9 Cit yo f Petalum a (Advanc e cop

yo f EP Apropose

d plan ) A R 10 0 91/06/1 4 Levine-Frick e Sol a Optica l USA , Monthl ystatu s rp t o f RI/F S activitie s In c durin g 5/91 , w/appendi x A(respons e t o

EP A1/2/9 1 comment s o n R I rpt ) & T L t o M Montgomeryf r M Adam s

### Attachmen t B SOL AOPTICA

L SDPERFUN

D SIT E PETALUMA , CALIFORNI A RESPONSIVENES S SUMMAR Y A . OVERVIE W A t th e tim e o f th e publi c commen t period , EP Apropose d a preferre d alternativ e fo r th e Sol a Optica l Superfund sit e i n Petaluma , California . EPA' s recommende d alternativ e addresse d th e groundwate r contaminatio n proble ma t th e site . Th e selecte d remedyspecifie d i n th e Recor d o f Decisio n (ROD ) call s fo r tw o ne w extractio n well s and th e conversio n o f tw o dee p monitorin g well s t o extractio n well s withi n Sola' s existin g treatmen t system . Judgin g fromth e fe w comment s receive d durin g th e publi c commen t period , a s wel l a s th e fe w peopl e wh o attende d th e publi c meetin g o n th e propose d plan , ther e i s littl e communit yconcer n abou t ris k fromth e Sol a site . EPA' s clean-u p alternativ e appear s t o b e supporte d b yare a residents . Thes e section s follow : * Backgroun

d o n Communit yInvolvement ; * Summaryo f Comment s Receive d durin g Publi c Commen t Perio d and Agenc yResponses ; * Communit yRelation s Activitie s a t Sol a Optica l site . B i Backgroun

d o n Communit yinvolvemen t Ther e ha s bee n relativel ylittl e communit yinteres t i n th e Sol a Optica l sit e and n o organize d communit yinvolvement . Followin g loca l newspape r article s o n th e site' s propose d listin g o n th e Nationa l Prioritie s Lis t i n 1988 , Cit yan d Count y official s reporte d som e inquirie s fro

mth e genera l public . Thes e inquirie s sough t informatio n an d reassuranc e tha t th e drinkin g wate r suppl ywa s safe . Th e publi c seeme d satisfie d wit h th e answer s provided . Th e loca l communit ywante d t o b e kep t informe d o f sit e activitie s throughou t th e Superfun d process , an

d EPAha s communicate d wit h th e publi c throug h variou s communit yrelation s activities . T o summariz e pas t communit yinvolvement , i t woul d b e fai r t o stat e tha t mos t resident s seeme d satisfie d wit h th e informatio n the

yreceive d abou t th e site , an d confiden t i n th e work EPAan

d Sol a wer e conducting durin g th e Remedia l Investigation/Feasibilit yStud y(RI/FS) .

### C : Summar yo f Comment s Receive d durin g Publi c Commen t Perio d and Agenc yResponse s Comment s raise d durin g th e Sol a Optica l publi c commen t perio d o n th e propose d pla n ar e summarize d below . Th e commen t perio d wa s hel d fromJun e 1 7 t o Jul y16 , 1991 . Al l o f th e followin g comment s wer e expresse d i n a lette r maile d t o EP Afromon e Petaluma famil y and represen t th e exten t o f comment s o n th e propose d plan . Althoug h a publi c meetin g o n th e propose d pla n wa s hel d durin g th e publi c commen t period , n o comment s specifi c t o th e propose d pla n wer e mad e a t tha t meeting . 1 . EPA' s preferre d clean-u p alternativ e wa s supported . 2 . Concer n wa s expresse d abou t possibl e advers e environmenta l and healt h impact s relate d t o th e transpor t an d disposa l o f th e use d charcoa l filte r fro mth e treatmen t system . EPAResponse : Carbo n filter s ar e containe d i n thei r ow n Departmen t o f Transportation-approve d transportabl e vessels . Spen t carbo n filter s hav e bee n shippe d i n thes e vessel s t o a carbon-regeneratio n facilit yi n th e Stat e o f Washingto n wher e theyhav e bee n thermall yregenerated . 3 . Th e commen t wa s mad e tha t th e disposa l o f contaminate d wate r int o th e sanitar ysewe r i s contrar yt o th e Cit yo f Petaluma' s pla n t o compos t th e treatmen t plan t sludg e fo r agricultural , park s an d othe r uses . Additionally , thi s residen t expresse d concer n tha t th e chemical s remainin g i n th e treate d wate r coul d pollut e th e Russia n Rive r and Sonoma Coast . EP AResponse ; Contaminate d wate r woul d b e effectivel ytreate d i n th e treatmen t work s o f th e sewag e system . Volatil e organi c compound s (VOCs ) i n th e contaminate d groundwate r discharge d int o th e Cityo f Petalum a sewag e treatmen t syste mwoul d likel y volatiliz e o r biodegrad e i n th e treatmen t works . Th e sewag e treatmen t syste

mdoe s no t discharg e int o th e Russia n Rive r o r Sonom a Coast . Additiona l question s regardin g th e qualit yo f discharg e fro

mth e citysewag e treatmen t work s shoul d b e directe d t o Steve Simmons , Wate r Service s Department , Cit yo f Petaluma , 1 1 Englis h Street , Petaluma , C A94952 , (707 ) 778-4392 .

### 4 . Concer n abou t th e wate r qualit yo f th e Petalum a Rive r wa s

expressed . Th e commente r disagree d wit h th e determinatio n tha t chemical s enterin g i t fromth e Sol a Optica l sit e wer e insignif

icant . EP AResponse : Wate r qualit ydat a fro mmonitorin g well s a t th e Sol a propert ylin e ar e a t o r belo w stat e o r federa l drinkin g wate r standards . Give n th e distanc e t o th e Petaluma Rive r (on e mile) , i t i s highl yunlikel ytha t an ychemical s fro m Sola' s groundwate r contaminatio n ar e enterin g th e Petalum a River . 5 . Aquestio n wa s pose d regarding groundwate r qualit ya t a residentia l are a 50 0 fee t fro mth e Sol a site . Thi s communit y membe r wondere d whethe r i t wa s possibl e tha t Sola' s contaminate d groundwate r ha d leache d int o thi s neighborhoo d o r coul d i n th e future . I f so , thi s perso n wante d t o kno w th e long-ter

meffect s o f such leaching , especiall ya s i t concern s childre n playin g i n th e backyard s o r vegetable s grow n i n th e soil . EP AResponse : N o residentia l neighborhoo d ha s a n elevate d ris k t o huma n healt h o r th e environmen t fro mSol a groundwate r contamination . Bot h shallo w and intermediat e dept h monitorin g well s locate d betwee n th e Sol a propert yan d th e residentia l are a describe d b

yth e commente r hav e detecte d n o contamination . EPAwil l continu e t o monito r thes e wells , though i t i s unlikel y tha t Sol a contaminatio n wil l show u p i n thi s neighborhood , a s i t i s upgradien t fro mth e site . Regardin g futur e leachin g o f th e contamination , beside s th e upgradien t factor , th e extractio n syste

mi s designe d t o captur e Sola' s contaminate d groundwater . 6 . Th e questio n wa s pose d a s t o wha t cause d th e contaminatio n a t Sol a an

d wha t Sol a i s doin g t o preven t thi s same proble m fro mhappenin g i n th e future . EPAResponse : Accordin g t o reporte d data , whe n th e underground storag e tank s wer e remove d ther e wer e n o leak s detected , bu t ther e wa s stainin

g o f th e back-fil l grave l surroundin g th e tanks . Thi s infer s tha t a spil l occurre d o n th e surfac e nea r th e tanks . Thi s same proble mwil l no t happe n i n th e futur e becaus e Sol a ha s fille d i n th e gap s i n th e concret e tha t ha d overlaye d th e tanks , discontinue d th e us e o f underground tank s an d institute d furthe r control s o n th e us e o f chemicals . Furthe r question s regarding spil l preventio n an d safet y precaution s shoul d b e directe d t o Mar k Adams , Manage r o f Environmenta l Affairs , Sol a Optical , 150 0 Cade r Lane , P.O . Bo x 6002 , Petaluma , C

A94953 , (707 ) 763-9911 .

### 7 . EPAwa s aske d wh ySol a doe s no t us e les s hazardou s o r non toxi c chemicals . EP AResponse : Th e tota l numbe r o f solvent s use d b ySol a ha s bee n reduce d t o one , whic h i s acetone . Furthe r question s regardin g processe s use d b ySol a shoul d b e directe d t o Mar k Adam s a t Sol a Optica l (see abov e #6) . D : Communit yRelation s Activitie s a t Sol a Optica l Sit e Communit yrelation s activitie s conducte d a t th e Sol a Optica l sit e t o dat e hav e include d th e following :

* EP Aconducte d communit yinterview s wit h loca l official s an

d intereste d resident s (Jun e 1989 ) ; * EP Aprepare d communit yrelation s pla n (Octobe r 1989 ) ; * EP Aprepare d and distribute d fac t shee t t o affecte d communit yan

d othe r interested partie s announcin g agreemen t wit h Sol a t o continu e investigatio n o f groundwate r contaminatio n (Octobe r 1989) ; * EP Amad e locall ytelevise d presentatio n o f workpla n fo r Remedia l Investigation/Feasibilit yStud y(RI/FS ) t o Petalum a Cit yCounci l (Octobe r 1989 ) ; * EPAprepare d an

d distribute d fac t shee t t o affecte d communit yan

d othe r intereste d partie s announcin g completio n o f Remedia l Investigatio n (Februar y1991) ; * EP Aprepare d and distribute d propose d pla n fo r cleanu p (Jun e 1991) ; * EPAra n publi c notic e i n Sant a Ros a Pres s Democra t announcing propose d plan , date s o f publi c commen t perio d an

d dat e o f publi c meetin g (Jun e 17 , 1991) ; * EP Ahel d publi c meeting a t Petaluma' s Veteran s Memoria l Buildin g t o discus s an d receiv e comment s o n th e propose d pla n (Jun e 25 , 1991) . Atranscrip t o f thi s meetin

g i s i n the Petalum a Publi c Library ; * EPA' s publi c commen t perio d o n th e propose d pla n laste d fro mJun e 1 7 t o Jul y16 , 1991 .