SFUN D RECORD S CT R 

## 210608 1 

# &EPA Sol a Optica l USA , Inc .

Superfun d Sit

e

; ENVIRONMENTA L PROTECTIO N AGENC Y • REGIO N 9 • SA N FRANClSpO , C A • JANUAR Y 200 7 

# EP A Proposes Amendin g th e Clean-u p Pla n fo r

Contaminate d Groun d wate r Propose d Pla n at a Glance Th e Proble m A groundwate r

extractio n an dtreatmen t

syste mbega n operatin g a t

th e Sol aOptica l USA , Inc . Superfun dSit e i n Petaluma , Californi ai n 1988 . Expande di n 1992 , th e syste mwa s expecte dt o restor e th e shallo w groundwate r t o clean-u p standard s withi n 15-2 0 years , achievin g tha t goa l betwee n 2007 an d2012 . However , afte r several year s th e effectivenes s o f

th e extractio n an dtreatmen t syste m appeare dt o stal l wit hrespec t t o certai n contaminants , concentration s o f

whic heventuall y stabilize da t level s abov e th e clean-u p standards . I n respons e t o th e diminish

in g valu e o f

th e system , th e responsibl e part y an dth e Unite dState s Environmenta l Protectio n Agenc y (EPA ) began t o conside r

alternativ e method s fo r

restorin g ground

wate r quality . I nth e meantime , du e t o natura l degradatio n processe s th e contaminatio n level s droppe dan dclean-u p level s hav e no w bee n achieve dfo r al l bu t on e contaminan t whic hi s stil l presen t

i nelevate dconcentration s a t asingl e wel l o nth e site . 

### Th e Solutio n EP A propose s t o formall y adop t Monitore dNatura l Attenu

atio n(MNA ) a s th e metho dfo r completin g groundwate r restoration . MN A i s a n approac htha t relie s o n natura l processes , suc ha s biodegradation , t o attai n th e clean-u p goal s withi nareasonabl e tim e frame . EP A als o propose s t o restric t us e o f th e contaminate dgroundwate r unti l th e groundwate r

meet s California' s drinkin g wate r standar dfo r th e remainin g contaminant , 1,1-DCA . 

### You r Comment s Th e publi c i s invite dt o participat e i n th e remed y selectio n proces s an dt o submi t

comment s o n th e propose damend

men t t o th e clean-u p plan . Comment s o n thi s Propose d Plan are welcome , bothdurin g our publi c meetin g andby writin g t o EP A (se e bac k

page fo r contac t information) . EP A wil l conside r

you r comment s i nmakin g ou r

fina l clean-u p decision , an dwritte n response s t o an y comment s wil l b e include di nth e fina l decisio n document . 

# Communit y Meetin g Wednesday , January 24,200 7 6:3 0 p.m . 

### - 8:3 0 p.m . 

### Petalum a Publi c Library , Meetin g Roo m 10 0 Fairground s Driv e Petaluma , Californi a 

# Commen t Period January 20 , 200 7 throug h Februar y 20 , 2007

Th e Sol aOptica l USA , Inc . (Sola ) Superfun dSit e (Site ) i s i nPetaluma , California , a t 1500 Cade r

Lane , jus t

wes t o f th e intersectio n o f

Lakevill e Highwa y an dInterstat e 101 . Fro m197 8 throug h2001 , Sol amanufacture deyeglas s lense s a t th e Site . Whe n operation s firs t began , Sol astore d variou s solvent s use di nit s manufacturin g proces s i n undergroun dstorag e tank s a t th e Site . Afte r

discoverin g contaminatio ni n th e groundwate r nea r thos e tanks , Sol a remove dth e tank s an dha s bee n responsibl e fo r cleanin g u p th e remainin g volatil e organi c compoun d(VOC ) contaminatio n eve r

since . Th e Sol aSite wa s liste do n th e Nationa l Prioritie s Lis t

(o r Superfun dList ) i nFebruary 1990 . Th e aquife r

i s use da s th e sourc e o f

drinkin g wate r

fo r th e Cit y o f Petaluma . On e o f

th e City' s groundwate r

extrac tio nwell s wa s locate dnear th e Sol aSite , bu t

i t wa s no t impacte db y th e contaminatio n a t th e Sol aSite . However , th e wel l wa s shu t

dow n s o a s no t

t o interfer e wit hground

wate r clean-u p efforts .I n 1991 , EPA decide dtha t th e groundwate r

treatmen t syste mSol aha dbee n operatin g shoul db e expanded . Sol a complie dan doperate dth e expande dsyste mfo r anothe r si x years . Eventually , however , th e syste mbecam e les s an d les s effective , an dSol astoppe doperatin g i t i n 1997 . Sinc e then , th e level s o f

contaminatio n i n th e groundwate r hav e continue dt o decline , an donl y on e smal l are ao f contami

natio n remains . EP A i s no w proposin g t o adop t adifferen t approac ht o addres s th e clean-u p - o r "remediation " - o f tha t smal l area . EP A selecte dth e origina l clean-u p pla n an dwil l selec t thi s propose damendmen t

i n accordanc e wit hSectio n 11 7 o f th e Comprehensiv e Environmenta l Response , Compensa

tion , an dLiabilit y Ac t

(CERCLA) , a s amended , 4 2 U.S.C . § 117 , an d4 0 C.F.R . § 300.435(c)(2)(ii ) o f th e Nationa l Oi l an dHazardou s Substance s Pollutio n Contingenc y Pla n (NCP) . EP A i s th e lea dagenc y responsibl e fo r directin g th e CERCL A remediatio n process ; th e Sa n Francisc o Ba y Regiona l Wate r

Qualit y Contro l Boar d(Regiona l Board ) i s th e suppor t

agency . Thi s Propose dPlan i s bein g coordi

nate dwithth e Regional Board . Thi s Propose dPla n describe s tw o alternativ e method s fo r achievin g th e clean-u p standard s at th e Site . Th e Pla

n the n identifie s EPA' s preferre dalternative , explain s EPA' s rational e fo r

thi s preference , an dpresent s th e ke y underly

in g facts . Furthe r

informatio n ca n b e foun di n th e project' s publicl y availabl e Administrativ e Record . Th e publi c i s invite dt o participat e i n th e remed y amendmen t proces s an dsubmi t

comment s o n th e Propose dPlan . 

# Site Backgroun d A s note dabove , Sol amanufacture deyeglas s lense s at th e Site fo r ove r 2 0 years . It s facilit y wa s comprise do f on e manufacturin g buildin g an da n adjoinin g administratio n offic e building . Si x 1,000-gallo n undergroun dstorag e tank s (USTs ) wer e locate dbehin dth e nort hcorne r o f th e manufacturin g facility . Th e tank s wer e use dt o store solvent s suc ha s 1,1,1-trichloroethan e (1,1,1-TCA) , aceton e an dmethanol .

Figure 1: Sola Optical Superfund

Site location Pag e 2 Sol a Optica l USA , Inc
. Superfun d Sit e

### I n1982 , Sol afoun dlo w concentration s o f VO C contami

natio n i n th e groundwate r

beneathit s property near

th e si x USTs . I n 1983 , th e Regiona l Boarddirecte dSol at o investigat e th e groundwate r contaminatio n at

th e Site . Sol aidentifie dth e followin g chemical s i n th e groundwa

ter : 1,1-dichloroethan e (1,1-DCA) , 1,1-dichloroethen e (1,1-DCE) , methylen e chloride , an d1,1,1-TCA . Thes e chemical s appeare dt o hav e originate dfro mth e grave l surroundin g the tan k

andadjacen t

soils . In 1985 , Sol a remove dth e si x USTs , th e surroundin g grave l an dsevera l fee t o f soi l fro mth e side s an dbotto mo f th e excavation . Furthe r investigatio n reveale dth e exten t o f th e groundwa

te r contamination . I n 1987 , th e Regiona l Boardordere d Sol at o construc t

an doperate agroundwate r extractio n an d treatmen t (GWET ) system . Th e treate dgroundwate r wa s discharge dint o Adob e Creek , jus t northwes t

o f th e Site , unde r apermi t fro mth e Regiona l Board . Th e GWET syste moperate dfro m198 8 throug h1997 . I n1989 , EP A becam e th e leadagency , an dtoo k charg e o f directin g remedia l activitie s a t th e Site . On e step i n tha t proces s wa s addin g th e Sit e t o th e Nationa l Prioritie s List , whic hoccurre do n February 21 , 1990 . Pursuan t t o an administrativ e order , Sol aconducte dfurthe r environmenta l samplin g an dcomplete dafeasibilit y stud y o f clean-u p option s i n1991 . Base do ntha t stud y an dit s ow nris k assessment , EP A issue daRecordo f Decisio n (ROD) , whic hdocumente dit s determinatio n tha t a nexpande d GWE T syste mwa s th e mos t appropriat e metho dfo r remediatin g contaminatio n at th e Site . Th e enhanced GWE T syste mconsiste do f th e followin g elements :

• Operatio n o f

th e eigh t existin g extractio n well s • Constructio n an doperatio n o f tw o additiona l shallo w extractio n well s • Conversio n o f

tw o existin g monitorin g well s t o dee p extractio n well s • Constructio n an doperatio n o f additiona l pipin g fo r ne w an dconverte dwell s • On-sit e treatmen t

an doff-sit e discharg e t o eithe r th e nearb y cree k

o r t o th e Cit y o f Petalum asewag e treatmen t system . Th e enhance dsyste mbegan operatin g i n 199 2 an dwa s expecte dt o restor e th e shallo w groundwate r t o clean-u p standard s withi n 15-20 years . Initially , concentration s o f VO C contaminatio n at

th e Site decrease dsignificantly . B y 1997 , however , th e rat e o f contaminan t

reductio n slowe dt o almos t zero . Groundwa

te r monitorin g dat aa t

fou r well s showe dtha t

concentra tion s o f tw o contaminant s - 1,1-DC Ean d1,1,-D C A - appeare dt o hav e stabilize da t level s abov e th e clean-u p standards . Th e extractio n an dtreatmen t syste mwa s n o longe r effectivel y removin g thes e low-leve l contaminant s fro mth e groundwater . A t

tha t point , Sol arequeste dan d receive dpermissio n t o shu t of f th e GWE T system . Fo r

th e nex t tw o years , Sol asample dan danalyze dth e well s frequentl y t o ensur e tha t

contaminan t

level s di dno t increas e o r

"rebound. " Whe n contaminan t level s contin

ue dt o slowl y declin e withou t extractio n an dtreatment , Sol apresente dth e dat aan dtechnica l analysi s t o EP A an d receive dpermissio n t o decommissio n th e GWE T system . Sol acontinue dt o monito r

th e groundwate r

contaminatio n biannuall y thereafter . I n 2001 , Sol aanalyze dth e naturall y occurrin g change s t o th e contaminatio n tha t ha dbee n observe dsinc e th e decommissionin g o f th e extractio n system . EP A approve dth e analysi s i n 2002 . Curren t Statu s o f Cleanu p B y 2002 , onl y tw o well s reflecte dcontaminatio n abov e th e clean-u p standards : wel l E- 5 an dwel l W-27 . Wel l E- 5 showe dconcentration s o f

1,1-DC Eabov e th e clean-u p standar dunti l 2004 , whe n th e leve l droppe dbelow , an dha s consistentl y remaine dbelow , th e standard . Wel l W-2 7 i s no w th e onl y wel l tha t

stil l show s concentration s above th e standar dfo r

an y contaminant . A s o f

Decembe r

2006 , th e concentratio n o f

1,1-DC A wa s 1 2 part s per billion , a s compare dt o th e clean-u p standar do f 5 part s pe r

billion . Thi s i s likel y du e t o th e fac t that W-2 7 i s directl y dow n gradien t fro mth e locatio n o f

th e origina l contaminan t release , an dth e las t

o f th e contaminant s hav e slowl y bee n release dfro mth e soil s an dflowe ddow n t o W-27 . Groundwate r

dat areflec t

tha t th e contaminan t

concentra tion s i n W-2 7 initiall y increase dwhe n th e GWE T system wa s decommissioned , bu t

hav e sinc e bee n declinin g steadily . Fo r

th e pas t tw o years , th e concentratio n o f 1, 1 - DC A ha s decline dfro m2 2 part s pe r billio n t o 1 2 part s pe r billion , indicatin g tha t

natura l processe s ar e reducin g level s o f contaminants . Non e o f

th e othe r monitorin g well s hav e detectabl e level s o f an y contaminatio n abov e an y o f th e othe r VO C clean-u p standards . Base do n thi s data , th e are ao f

remainin g contaminatio n appear s t o exten dacros s one acre or

les s in the shallo w aquifer . Institutiona l Control s Institutiona l control s ar e actions , suc ha s legal controls , tha t hel p minimiz e th e potentia l fo r huma n exposur e t o contaminatio n a t

Superfun dsite s b y ensurin g appropriat e lan do r resourc e us e o r

restrictions . On e commo n institu

tiona l contro l i s arestrictiv e covenan t whic hi s a n agree ment , recorde dwithth e count y recorder' s office , whereb y alan downe r

agree s t o restric t

th e us e o f

hi s o r he r prop erty . In it s 199 1 healt

hris k assessment , EPA recommende d
Januar y200 7 Page Sthat

institutional control s b e implemente dat th e Site t o preven t an y us e o f

th e contaminate dgroundwate r fo r drinkin g wate r

supplie s befor e i t

i s cleane du p t o drinkin g wate r standards . Th e remedy selecte di n th e 199 1 ROD , however , di dno t

includ e institutiona l controls . EP A no w propose s t o ad dinstitutiona l control s t o th e remedy . 

# Summary of Site Risk

s I n 1991 , EP A prepare daris k assessmen t

t o evaluat e th e huma nhealt han denvironmenta l risk s pose db y contamina

tio n at th e site . 

### Huma n Healt h Risks A huma n healthris k

assessmen t

begin s b y identifyin g th e chemica l contaminant s tha t exis t i n th e environmen t

i n sufficien t quantitie s t o caus e apotentia l concern . Next , th e assessmen t

evaluate s th e pathway s throug hwhic hth e chemical s ca n trave l fro mth e environmen t t o humans . The n i t estimate s th e duratio n o f

possibl e chemica l expo sur e t o humans . Finally , i t use s al l o f

thi s informatio nt o calculat e ahuma n healt hrisk . Thi s ris k i s presente di n tw o parts , th e carcinogeni c effect s (cancer-causin g effects) , an d th e non-carcinogeni c effect s (al l othe r healtheffect s beside s cancer) . Th e carcinogeni c effec t i s show n i n term s o f an additional 1 i n amillio n chanc e o f contractin g cancer , abov e th e norma l rate , fro mth e chemica l exposure . Th e non-carcinogeni c effec t i s show n a s ahazar dquotient ; value s greater

tha n 1 indicat e that

an effec t o n huma n healt hwil l occur , an dles s tha n 1 indicate s tha t n o effec t wil l occur . Th e 199 1 ris k

assessmen t

fo r th e Site identifie dth e follow

in g 1 2 volatil e organi c compound s a s posin g apotentia l concern at

th e Site : acetone , butanone , 1,1-dichloroethane , 1,2-dichloroethane , 1,1-dichloroethene , freo n113,4

- methyl-2-pentanone , tetrachloroethene , toluene , 1,1,1

- trichloroethane , 1,1,2-trichloroethane , trichloroethene . VOC s ar e extremel y volatile , meanin g the y vaporiz e easil y an dthu s constantl y mov e fro mon e mediu mt o another , fo r exampl e fro msoi l t o wate r o r air . Th e assessmen t

establishe dtha t

th e mai n pathwa y throug h whic hhuman s coul db e expose dt o thes e chemical s i s throug hthei r

homes . I f

resident s wer e t o us e groundwate r fo r hom e use , the y migh t

drin k th e contaminate dwate r

o r absorb i t throug hthei r

skin . An y flo w o f

wate r fro ma fauce t o r showerhea dcoul dreleas e contaminant s int o indoo r ai r where resident s migh t

inhal e them . Th e chemi

cal s coul dals o mov e int o indoo r ai r fro mth e groundwate r andsoi l beneathany home s in aprocess know n as "vapo r intrusion. " Not e that

thi s potential exposur e i s base do n a hypothetical futur e residential use . Th e Sit e i s currentl y use dfo r ligh t industrial/commercial purposes , an dth e owner s o f th e Site propert y d o no t

pla n an y residentia l uses . Also , th e existin g plum e o f groundwate r

contamina

tio n doe s no t

exten dbelo w an y residences , an dn o drinkin g wate r well s pum p nea r

th e plume . Th e Site an dth e surroundin g propertie s receiv e wate r fro mth e Cit

y o f Petaluma' s municipa l wate r supply , whic hi s no t

impacte d b y th e site . Th e assessmen t

calculate dtha t

aperso n wh o live di n a hous e directl y abov e th e contaminatio n an dwh o wa s expose dt o th e resultin g vapo r intrusio n al l o f

hi s o r he r lif e woul dhav e an exces s cance r ris k o f 9 i n 1,000,000 . Th e nationa l averag e rate o f cance r fro mal l cause s i s 1 i n 4 . Th e calculate d"excess " cance r ris k mean s tha t

i f a millio n peopl e wer e expose dt o thi s amoun t o f contamina

tio n fo r thei r lifetimes , ther e migh t

b e nin e additional case s o f cancer . Th e assessmen t

conclude dtha t

aperso n woul d no t experienc e an y non-carcinogeni c healt heffects . Th e assessmen t

als o calculate dtha t

aperso n wh o use dth e contaminate dgroundwate r a s residentia l wate r

suppl y ove r th e cours e o f

hi s o r he r entir e lif e woul dhav e an additional 1 i n 10,000 ris k

o f contractin g cancer . Th e assessmen t conclude dtha t

thi s perso n woul dno t

experienc e an y non carcinogeni c healt

heffects . 

### Subsequen t Ris k

Evaluatio n Additiona l ris k

evaluation s wer e conducte di n 200 5 a s part o f th e Five-Yea

r Review . EP A performe dascreenin g leve l evaluatio n o f

th e potentia l fo r

remainin g level s o f

contami

nant s t o caus e negativ e healt heffect s eithe r b y enterin g commercia l building s vi avapo r intrusio n o r

throug h huma n ingestio n o f

home-grow n produce . T o evaluat e th e potentia l ris k o f vapo r intrusion , EP A compare dth e curren t

groundwate r

contaminan t

concentra tion s t o it s publishe d"Target Groundwate r

Concentra

tions " (Draf

t Guidanc e fo r

Evaluatin g th e Vapo r

Intrusio n t o Indoo r Ai r Pathway fro mGroundwate r an dSoils , EP A OSWER , Novembe r

2002 , Do c No . EPA530-D-02-004 ) an dth e Regiona l Board' s publishe d"Groundwate r Screen

in g Level s fo r

Evaluatio n o f

Potential Vapo r

Intrusio n Concerns " (Screenin g Fo r Environmenta l Concern s a t Site s Wit hContaminate dSoi l an dGroundwater , Regiona l Board , Februar y 2005) . Al l curren t contaminan t

concen tration s i n th e groundwate r wer e foun dt o b e wel l belo w bot hth e targe t

an dscreenin g levels . O n thi s basis , EP A determine dtha t

vapo r intrusio n doe s no t

pos e ahuma n healt hris k

a t thi s Site .

Pag e 4 Sol a Optica l USA , Inc
. Superfun d Sit eT o evaluat e th e potentia l effect s o n garden s an dhome

grow n fruit s an dvegetables , EP A examine dothe r existin g studie s o n th e subject . Researc hdemonstrate s tha t volatil e chemical s d o no t

buil du p i n th e plan t

tissue s eve n i f contaminate dgroundwate r beneat hagarde n manage s t o reac hth e plant s an dth e chemical s ar e absorbe db y th e plants . Whe n volatil e chemical s mov e int o plan t leaves , the y ar e release dthroug hth e tin y opening s i n th e plan t leave s wher e ga s exchang e occur s an dtherefor e d o no t accumulate . Studie s hav e als o show n tha t volatil e chemi

cal s take n u p throug hplan t root s ten dt o concentrat e i n th e cell s nea r th e surfac e o f

th e roots . Fo r

roo t vegetable s suc ha s beets , carrot s an dpotatoes , thes e cell s ar e typicall y los t durin g washin g an dpeelin g o f th e produce . Plant s ar e als o abl e t o brea k

dow n o r degrad e volatil e chemicals . Thus , an y suc hchemical s take n u p b y th e plant s ma y b e presen t temporaril y i n th e root s an dstem s o f th e plan t bu t ar e muc hles s likel y t o b e presen t i n th e leave s o r

othe r above-groun dpart s o f

th e plant . I n summary , existin g studie s indicate dtha t

uptak e an daccumulatio n o f volatile chemical s i n plants , an dsubsequen t exposur e t o human s wh o ea t them , woul db e minimal . 

### Ecologica l Ris k A s par t o f th e 199 1 ris k

assessment , EP A als o prepare da n ecologica l ris k

assessmen t

t o evaluat e possibl e impact s t o th e environment . Th e ecologica l assessmen t focuse do n possibl e impact s o n th e nearb y creek , Adob e Creek . Thi s cree k i s th e closes t

surfac e wate r

body t o th e Site . A t

th e tim e o f th e assessment , alocal grou p ha dlaunche da projec t t o reintroduc e anadromou s steelhea dtrou t t o th e creek . EP A examine ddat afro mgroundwate r monitorin g well s betwee n th e Sol afacilit y an dAdob e Creek . Base do n thi s data , EP A determine dtha t n o contaminant s wer e movin g toward s o r

ha dreache dth e creek . Th e assessmen t di d determin e tha t

i f th e groundwate r

extractio n syste mwer e no t operating , contaminate dgroundwate r fro mth e Sol a facilit y woul dflo w i n th e directio n o f Adob e Creek . However , th e contaminan t concentration s i n th e groundwa

te r beneathth e Sol afacilit y wer e no t aconcer n becaus e the y wer e belo w federa l surfac e wate r qualit y criteri afo r th e protectio n o f

aquati c life . Today , th e Site i s no t

muc hdifferen t

tha n i t wa s i n 1991 . Th e on e are atha t

ha s no t ye t attaine dth e groundwate r clean-u p standar di s locate do n th e parce l adjacen t t o th e origina l facilit y property . Thi s parce l i s currentl y a n ope n fiel di n th e proces s o f

bein g develope dfo r

ligh t industrial / commercia l use . Approximatel y one-thir do f tha t propert y ha dbee n recentl y graded . Th e fiel dha s no t otherwis e change dsinc e th e tim e o f th e origina l ris k

assessment . N o ne w ecological receptor s wer e foun dat th e Site . 

# Opportunit y fo r Publi c Commen t EP Awil l accep t comments o n thi s Propose d Pla n fro m Januar

y20 , 200 7 throug h Februar y20 , 2007 . Durin g that period , writte n comment s ca n b e submitte d to Jos e Garci a a t EPA(se e bac k

pag e fo rcontac

t information)
. Comment s presente d a t th e Propose d Pla n Publi cMeeting , schedule d fo r Januar y24 , 2007 , wil l b e recorded
. Afte rEP Areview s publi ccomment s th e Agencywil l formall yannounc e th e selecte d rem ed yi n a n amendmen t t o th e 199 1 RO D (RO D Amendment)
. Response s t o publi ccomment s wil l b e include d i n th e RO D Amendment
. Th e selecte d remed yma ydiffe rfro m th e preferre d alternativ e i n thi s pla n a s a resul t o f publi ccomments . EP Aen courage s th e publi ct o revie wth e report s i n th e Administrativ e Record an d commen t o n an yo f th e alternative s presente d i n thi s Propose d Plan
. A cop yo f th e Administrativ e Recor d i s locate d at th e Petalum a Publi c Library , 10 0 Fairground s Drive , Petaluma , California , an d at th e EP ARegio n 9 of fic e i n Sa n Francisco
. 

# Scop e of Thi s Actio n Thi s remed y addresse s th e smal l portio n o f th e Sit e wher e contaminatio n remain s i n th e groundwate r a t concentra tion s exceedin g th e clean-u p goal . Onc e th e already-lo w level s o f 1,1-DC A hav e bee n reduce dt o th e drinkin g wate r standard , Sit e remediatio n wil l b e complete , an dth e Sit e ma y b e eligibl e fo r

deletio n fro mth e Superfun dList . 

# Descriptio n o f Alternative s Th e alternative s fo r

completin g remediatio n o f thi s sit e are : (1 ) N o Action ; (2 ) Groundwate r

extraction , treatment , an doff-sit e discharge , wit hinstitutiona l controls ; an d (3 ) Monitore dnatura l attenuatio n wit hinstitu

tiona l controls . 

### Remedia l Alternativ e 1 (RA-1 ) RA- l consist s o f

n o actio n bein g taken , no t eve n monitor

ing . EP A i s require dt o evaluat e thi s optio n fo r compariso n purposes . Januar y200 7 Pag e 5

### Remedia l Actio n Alternativ e 2 (RA-2 ) RA- 2 consist s o f

mos t o f th e remedia l actio n selecte di n th e 199 1 RO D (th e GWET system ) plu s institutiona l controls . Thi s alternativ e woul d requir e extractin g groundwate r fro m th e shallo w aquifer , treatin g i t on-site an ddischargin g i t

off-sit e int o Adob e Creek . Th e origina l GWET syste m wa s dismantle di n 1998 , s o i t woul d nee dt o b e rebuil t

i f selecte di n thi s RO D Amendment . I n addition , thi s alternativ e woul drequir e implementa

tio n o f institutiona l control s a

t th e Site . Th e curren t

owner s woul db e require dt o recor drestrictiv e cov enant s whic hwoul drestric t us e o f th e groundwate r

unti l i t meet s th e Califor

ni adrinkin g wate r

standard . Th e objectiv e o f

thi s restrictio n woul db e t o preven t

use s o f th e groundwate r tha t coul dresul t

i n unacceptabl e exposur e o f

human s o r

th e environ

men t t o th e groundwater . Thi s alternativ e woul dtake an estimate d1 8 month s t o construc t

ane w groundwa

te r treatmen t

system , an dwoul dtak e a n estimate don e t o thre e year s t o attai n th e clean-u p goal . 

### Remedia l Actio n Alternativ e 3 (RA-3 ) RA- 3 consist s o f

th e sam e institu

tiona l control s propose dfo r RA- 2 a s wel l a s adoptio n o f

monitore dnatura l attenuatio n (MNA ) a s th e metho dfo r achievin g Sit

e remediatio n goals . MN A i s aclean-u p approac htha t relie s o n natura l processe s t o reduc e contaminan t

concentration s an d achiev e clean-u p objective s withi n a reasonabl e tim e frame , a s compare dt o othe r mor e activ e methods . Natura l attenuatio n include s avariety o f physical , chemica l o r

biologica l processe s - suc ha s dilutio n an d chemical breakdow n - that , unde r favorabl e conditions , ac t

withou t huma n interventio n t o reduc e th e mass , toxicity , mobility , volum e o r concentratio n o f

contaminant s i n th e Overal l Protectio n o f Human Health an d th e Environmen t Ho w risk s ar

e eliminated , reduce dor

controlle dthroug h treatment , engineerin g o r

institutiona l controls . Complianc e with Applicabl e o rRelevan t an d Appropriate Requirements (ARARs ) Federa l an dstate environmental statute s met and/o r ground s fo r

waive r provided . Long-ter m Effectivenes s Maintai nreliabl e protectio no f huma nhealt

han dth e environmen t

ove r time , onc e cleanu p goal s ar e met . 

# 29 ) :; i-.-i . Reductio n o f

Toxicity , Mobilit

y o r «f | '"" nVolum e (TMV ) Through Treatment <"^Ij. f Abilit y o f

aremed y t o reduc e th e toxicity , mobilit y u^ljjj^p „ an dvolum e o f

th e hazardou s contaminant s presen t a t th e site . Short-term Effectivenes s Protectio no f

huma nhealt han dth e environmen t durin g constructio nan dimplementatio nperiod . ,* atImplementability '"T^ K ' I Tecnn ' ca l an dadministrativ e feasibilit y o f a '-'isffr ' r

remed >' ' includin g th e availabilit y o f material s 0 . i s :1 D ;VS£

^ an dservice s neede dto carry i t out . Cost < jgjj?t £^> Estimate dcapital , operatio nan dHsl . !igr t maintenanc e cost s o f

eac halternative . 

# A / \ State Acceptanc e

Stat e concur s with , oppose s o r ha s n o commen t o nth e preferre dalternative . Communit

y Acceptanc e Communit y concern s addressed ; communit y preference s considered . Figure 2: Diagram

of EPA's 9 Remedy Criteria groundwater . Thi s alternativ e woul dtak e n o additiona l tim e t o construc t sinc e onl y th e existin g monitorin g well s wil l b e necessary . EP A estimate s tha t thi s alternativ e wil l achiev e th e clean-u p standard s withi n on e t o thre e years . 

# Evaluatio n o f Alternative s Th e purpos e o f

thi s analysi s i s t o compar e th e remedia l alternatives . Thi s analysi s examine s th e thre e remedia l actio n alternative s usin g th e nin e evalua

tio n criteri aestablishe di n th e National Contingenc y Plan , 4 0 CFR§ 300.430(e)(9) . Th e resultin g strength s an dweaknesse s o f th e alternative s ar e the n weighe dt o identif

y th e alternativ e providin g th e bes t balanc e amon g th e nin e criteria . Th e nin e criteri aan dth e relativ e performanc e o f th e alternative s i nrelatio n t o eac hcriterio n an deac hothe r ar e summarize di n Tabl e 1 . Page 6 Sol a Optica l USA , Inc
. Superfun d Sit e

# SOLA OPTICA L USA , INC . CLEAN-U P 

# ALTERNATIV E EVALUATIO N TABL E

Evaluatio n Criteri a Alternativ e 1 N o Actio n Alternativ e 2

Groundwate r Extractio n & Treatment , Institutiona l Control s Overal l Protect!venes s 

# O Complianc e wit h Stat e an d Federa l Requirement s (ARARs ) 

# O Long-ter m Effectivenes s Implementabilit

y Short-ter m Effectivenes s 

# O * \< , ' ,'

- i* f n" t /7T^ , r ' < t I' l' t ..^i^t*«.''!'. ' ( <i i r 

### Reductio n o f Toxicity , Mobility,o rVolum e by Treatmen t 

## fr'^r r•* " ' f' 4: : 

## iiJ'^tf 1 

## ' " Estimate d Cost , Presen t Wort h 

## $ 0 

## $572,00 0

"
. I'" ' -•"• • 

### Stat e Agency Acceptanc e Th e Stat e ha s n o comment s o n EPA' s Propose d Pla n an d RO D Amendment
. 

## Communit y Acceptanc e Communityacceptanc e o f th e preferre d alternative s wil l b e evaluate d afte rth e publi c commen t period
. I = Fully meets criteri a = Partiall y meet s criteri a QJ ) = Does not mee t criteri a Table 1: Sola clean-up

alternatives

comparison

Januar y200 7 Pag e 7

# EPA' s Preferre d Alternativ e Afte r evaluatin g th e clean-u p options , EP A prefer s monitore dnatura l attenuatio n wit hinstitutiona l control s (RA-3 ) a s th e remed y tha t

provide s th e bes t

balanc e o f

th e criteria . EP A expect s RA- 3 t o satisf y th e followin g statutor y requirement s o f CERCLA , Sectio n 121(b) : (1 ) b e protectiv e o f huma n healt han dth e environment ; (2 ) compl y wit hARAR s (o r justify awaiver) ; (3 ) b e cost-effective ; (4 ) utiliz e permanen t solution s an dalternativ e treatmen t technologie s o r

resourc e recov er y technologie s t o th e maximu mexten t practicable ; an d(5 ) satisf y th e preferenc e fo r

treatmen t

a s aprincipa l element . Onc e th e clean-u p standar dfo r 1,1-DC A ha s bee n reached , EP A believe s tha t n o contaminatio n abov e clean-u p level s wil l remai n onsite , an dan y us e restriction s ma y b e lifted .

Figure 3: Groundwater

under treatment

through natural attenuation. In

natural attenuation, one

mechanism

at work is the break-down

of contamination

by natural bacteria in the ground, depicted

conceptually

in this figure. Pag e 8 Sol a Optica l USA , Inc
. Superfun d Sit e

# Fo r Mor e Informatio n I f yo u have question s o rcomment s regardin g th e Sol a Optica l USA , Inc
. Superfun d Site , pleas e contact : Dante Rodrigue z Remedia l Projec t Manage r U.S
. EPA , Regio n 9 7 5 Hawthorn e St
. (SFD-7-1 ) Sa n Francisco , C A9410 5 email : Rodriguez.dante@epa.gov phone : (415 ) 972-316 6 

### fax:(415)947-352 6 Jos e Garci a CommunityInvolvemen t Coordinato r U.S
. EPA , Regio n 9 7 5 Hawthorn e St
. (SFD-3 ) Sa n Francisco , C A9410 5 email : garcia.jose@epa.go v 

### Phone:(415)972-333 1 fax:(415)947-352 8 Yo u mayals o cal l EPA' s toll-fre e Superfun d hotlin e an d leave a messag e that wil l b e forwarde d t o th e appropriat e EP Astaff
. Th e hotlin e numbe ri s 1-800-231-3075 .



# Sit e Repositor

y Petalum a Publi c Librar y 10 0 Fairground s Driv e Petaluma , Californi a (707 ) 763-980 1 Hours : Tues-We d 10:0 0 a.m . - 9:0 0 p.m . Mon , Thurs-Sa t 10:0 0 a.m . - 6:0 0 p.m . EP A Superfun d Record s Cente r 9 5 Hawthorn e St. , 4t h Floo r Sa n Francisco , CA9410 5 (415)536-200 0 Hours : Mon-Fri : 8 a.m . - 5 p.m .

Fo r mor e sit e informatio n visi t th e EP A Regio n 9 we b pag e www.epa.gov/region09/waste/sfund/superfundsites.html , select "Sit e Overviews " an d clic k o n Sol a Optica l USA , Inc
.

Januar y200 7 Pag e 9

# i s Amendin g th e Clean-u p Contaminate d Groundwate r a t Sol a Optica l USA , Inc . Superfun d Sit

e

Printe d o n 30 % Postconsume rRecycle d / Recyclabl e Pape r

Unite d State s Environmenta l Protectio n Agenc y Regio n 9 7 5 Hawthorn e Stree t (SFD-3 ) Sa n Francisco , C A9410 5 Attn : Jos e Garci a (SOL A1/07 ) FIRST-CLAS S MAI L POSTAG E & FEE S PAI D U.S
. EP A Permi t No
. G-3 5 Official Business Penalty for Private Use, $300 Address Service Requested

Pag e 1 0 Sol a Optica l USA , Inc
. Superfun d Sit e