# EXPLANATIO N OF SIGNIFICAN

T DIFFERENCES (ESD )
TH E CANNON

S ENGINEERIN

G BRIDGEWATE R SUPERFUN D SIT E (CEC )
MANAGEMEN

T O F MIGRATION OPERABLE UNI T



### BRIDGEWATER

, MASSACHUSETT

S

MA Y 201 3

U.S

. ENVIRONMENTA

L PROTECTIO

N AGENC Y NE W ENGLAN D - REGION 1 5 POS T OFFIC E SQUARE BOSTON , M

A 02109-391 2 

# 11I1I1I

H

SDM S DocI D 53606 3I . INTRODUCTIO N A . SIT E NAM

E & LOCATIO N Sit e Name : Cannons Engineering Bridgewate r Superfun dSit

e Sit e Location : Bridgewater , Massachusetts , Plymout h Count y

Cannon s Engineerin

g Bridgewate

r Superfun dSit e
B . LEA D & SUPPOR

T AGENCIE S Lea dAgency : Unite dStates Environmenta l Protectio n Agency (EPA )

• Contact: Derrick

Golden, EPA Remedial

Project Manager, (617) 918-1448 Suppor t Agency : Massachusett s Departmen

t o f Environmenta

l Protectio n (MassDEP

)

• Contact: Jay Naparstek, MassDEPDeputy Division Director, (617) 292 - 5697 C . LEGA L AUTHORIT

Y FO R ES D Thi s Explanatio n o f

Significan t

Difference s ("ESD" ) i s bein g issue d fo r th e Cannons Engineering Bridgewate r Superfun dsit

e ("Site" ) to documen

t achang e i n acomponen

t o f th e remed y a s originall y se

t fort h i n th

e Marc h 31 , 198 8

### Recor d o f Decisio n ("ROD" ) fo

rth e managemen

to f migratio n operabl e uni ta t th e Site . 31 0 CM R40.0932 , establishe

s groundwate

r classificatio

n fo rth e purpose s o f determinin

g remediatio

n requirement

s fo r groundwate

r a twast e disposa l site s withi n th e Commonwealt

h o f Massachusetts

. I n Octobe r o f 2012 , MassDE P indicate d tha tth e groundwate

r classificatio

n use d t o develo p th e 198 8 RO D wa s n o longe r appropriat

e an d identifie d th e curren t classificatio

n o f groundwate

r beneat h an d nea r th e site . Therefor e thi s ES D revise s th e groundwate

r cleanu p level s whic h mus tno w b e tachieve d a tth e Site . Thi s reclassificatio

n i s furthe r discusse d i n sectio n I.D. , below

. Th e Unite d State s Environmenta

l Protectio n Agenc y ("EPA" ) i

s require d t o publis h thi s ES D b y Sectio n 117(c ) o f th e Comprehensiv

e Environmenta

l Response , Compensatio

n an d Liabilit y Ac t(CERCLA) , 4

2 U.S.C . § 9617(c) , an

d th e rul e a t4 0 C.F.R . § 300.435(c)(2)(i) . Unde r Sectio n 117(c ) o f CERCLA , 4

2 U.S.C . § 9617(c) , th

e rul e a t4 0 C.F.R . 300.435(c)(2)(i) , an

d EP A guidanc e (Offic e o f Soli d Wast e an d Emergenc

y Respons e [OSWER

] Directiv e 9200.1-23P), i f

th e EP A determine

s tha t difference s i n th e remedia l actio n significantl

y chang e bu td o no tfundamentall

y alte r th e remed y selecte d i n th e ROD , wit

h respec tt o scope , performance

, o rcost , th e EP A shal l publis h a n ES D betwee

n th e remedia l actio n bein g undertake

n an d th e remedia l actio n se tfort h i n th e ROD , an d th e reason s suc h change s ar e bein g made . EP A ha s determine

d tha tth e adjustment

s t o th e RO D provide d i n thi s ES D ar e significant

, bu td o no tfundamentall

y alte r th e overal l remed y fo rth e Cannon s Engineerin

g Bridgewate

r Superfun

d wit h respec tt o scope , performance

, o rcost . Therefore , thi s ES D i s bein g properl y issued . D . SUMMAR

Y O F CIRCUMSTANCE

S NECESSITATIN

G THI S ESD Th e remed y fo rth e Sit e a s selecte d i n th e 198 8 RO D include d bot h Sourc e Contro l an d Managemen

to f Migratio n ("MOM"

) components

. Th e cleanu p wa s divide d int o tw o operabl e units , a s describe d i n furthe r detai l i n Sectio n II.B. , o f thi s document

. Th e MO M portio n o f th e remed y include d a n extensiv e groundwate

r monitorin

g progra m t o assur e tha tgroundwate

r contaminatio

n abov e th e Maximu m Contaminan

tLevel s (MCLs) di

d no tmigrat e off-site , an d t o assur e tha ton-sit e contaminan

tlevel s naturall y attenuate

d t o level s belo w drinkin g wate r standards

. Th e MO M groundwate

r remed y wa s selecte d i n 1988 , befor e th e 199 3 revision s t o th e Massachusett

s Contingenc

y Pa n (MCP) . I

n 199 3 MassDE P revise d it s cleanu p regulations

, th e MCP . Include d i n thes e revision s t o th e MC P wa s th e establishmen

to f a ne w groundwate

r classificatio

n writte n specificall

y fo raddressin g remediatio

n a twast e sites . Th e MC P ha

s no w establishe

d th e followin

g thre e groundwate

r categorie

s fo r aquifer s locate d withi n th e Commonwealt

h of Massachusetts.

• GW- 1 - Applie

s t o groundwate

r tha ti s eithe r a curren tdrinkin g wate r resourc e (e.g. , withi

n a Zon e 2 of a publi c wate r supply ) o r a potentia

l futur e sourc e of drinkin g water . Standard

s fo r GW- 1 ar

e intende d t o addres s th e potentia l us e of groundwate

r a s a drinkin

g wate r source .

• GW - 2 - Applie

s t o groundwate

r tha ti s considere

d bot h shallo w an d wher e ther e i s currentl

y a structur

e buil to n th e lan d abov e th e groundwater

. Standard s fo r GW- 2 ar

e intende d t o addres s th e potentia l migratio n of volatil e oil o r hazardou

s materia l fro m groundwate

r int o th e indoo r air.

• GW- 3 - Applie

s t o all groundwate

r in th e Commonwealth

. Standard

s fo r GW 3 ar e intende d t o addres s th e advers e ecologica

l effect s tha tcoul d resul tfro m discharg e of oil o r hazardou

s materia l t o surfac e water . On Octobe

r 23 , 2012 , MassDEP conducte d a ne w groundwate

r us e & valu e determinatio

n specificall

y fo r th e Cannon s Engineerin

g Bridgewate

r Superfun

d site. Thi s evaluatio

n determine

d tha tth e groundwate

r a tth e Sit e i s actuall

y locate d withi n GW- 2 an

d GW- 3 groundwate

r classification areas. Th e Sit e i s n o longe r considere

d t o b e withi n a GW- 1 area

. A s a resul

tof thi s reclassification , drinkin g wate r standard

s suc h a s MCL s ar

e n o longe r applicabl

e o r appropriat

e fo r groundwate

r cleanu p goals. Se

e attachmen

t1 fo r a cop y of th e groundwate

r valu e an d us e determinatio

n performe

d b y MassDEP . I n accordanc

e wit h EP A Regio

n F s 199 6 Fina l Groun d Wate r Use an d Value Determinatio

n Guidance

, MADE P recommende

d a "mediu

m us e an d value " determinatio

n fo r th e groundwate

r a tth e Sit e i n Octobe

r 2012 . Thi s recommendatio

n i s base d o n th e non-drinkin

g wate r statu s of th e groundwate

r beneat h an d i n th e immediat

e vicinit y of th e site, th e presenc e of curren tan d potentia

l drinkin g wate r sourc e in nearb

y area s off-site , th

e presenc e of sensitiv e ecologica

l resource s in th e immediat

e vicinit y of th e site, an d th e locatio n of th e sit e withi n a Stat e designate

d Area of Critica l Environmenta

l Concer n (ACEC) . For furthe

r details , se

e th e MassDEP groundwate

r valu e an d us e determination

, attachmen

t1 . A s a resul

tof MADEP' s "mediu

m us e an d value " determinatio

n an d th e fac ttha t th e groundwate

r beneat h th e sit e ha s a non-drinkin

g wate r status , EP A consider

s tha tther e i s n o reasonabl

e likelihoo

d tha tth e groundwate

r wil l b e use d fo r drinkin g wate r purposes

, an d therefor

e ther e i s n o ingestio n exposur

e pathwa y whic h woul d lea d t o unacceptabl

e risk .Th e las tthre e year s o f annua l groundwate

r dat a ar e containe

d i n th e followin

g reports :

• Year 2

0 Groundwate

r Monitorin

g Report , date d 2/10/201 1

• Year 1

9 Groundwate

r Monitorin

g Report , date d 1/6/2010

• Year 1

8 Groundwate

r Monitorin

g Report , date d 3/23/200

9 E . AVAILABILIT

Y O F DOCUMENT

S Thi s ES D an

d al l supportin

g documentatio

n shal l becom e par tof th e Administrativ

e Recor d fo r th e Site . Th

e ESD , supportin

g documentatio

n fo r th e ESD , an d th e Administrativ

e Recor d ar e availabl e t o th e publi c a tth e followin

g location s an d ma y b e reviewe d a tth e time s listed : U.S . Environmenta

l Protectio

n Agenc y Record s Cente r 5 Pos tOffice Square

, Suit e 10 0 Boston, MA 0210

9 617-918-144

0 Monday-Friday : 9:0

0 a m - 5:0 0 p m Saturda y an d Sunda y - Close d Bridgewate

r Publi c Librar y 1 5 Sout h Stree t Bridgewater

, MA 0232

4 508-697-333 1 Monday-Wednesday : 9:0 0 a m - 8:0 0 p m Thursday : 10:0

0 a m - 5:0 0 p m Friday : 10:0

0 a m - 2:0 0 p m Saturday : 10:0

0 a m - 2:0 0 p m Sunday : Close

d II . SUMMAR

Y O F SIT E HISTORY

, CONTAMINATIO

N AN D SELECTE D REMED

Y A . SIT E HISTORY

, CONTAMINATIO

N AND SIT E RISK

S Th e Cannon s Engineerin

g Bridgewate

r Superfun

d sit e ("CEC" ) facilit

y i s a 7-acr

e sit e locate d i n a smal

l industria

l par k i n th e wester n par tof th e Tow n o f Bridgewater

, Massachusetts. Prio

r t o 1969 , th e industria

l par k consiste d of a woode d lowlan d bordere d t o th e north , south , an d eas tb y rura l agricultura

l land. Curren tlan d us e aroun d th e sit e consist s of industria l developmen

tin th e immediat e vicinit y t o th e nort h an d east , an d a woode

d lowlan d t o th e sout h an d west , an d agricultura

l an d residentia

l developmen

ti n th e outlyin g areas . Th e CE C Bridgewate

r sit e i s locate d i n th e southeaster

n portio n o f th e Tow n Rive r watershe

d whic h ha s a n estimate d are a of 5 6 squar e mile s an d feed s wate r suppl y wells fo rth e town s of Bridgewater

, Wes tBridgewater

, an d Raynham

. Hockomoc

k Swam p occupie s a larg e portio n of th e watershed

. Lak e Nippenicke

t i s th e larges tsurfac e waterbod

y locate d withi n 1 mil e of th e Site . Th e neares tdrinkin g wate r well , operate

d b y th e Tow n o f

Raynham , i s locate d 1,

3 mile s west o f th e Sit e o n th e shor e o f Lak e Nippenicket
. Th e CE C facilit y i s on

e o f th e fou r separat e bu t relate d site s whic h for mth e Cannons Sit

e Group
. Th

e others ar

e Cannons Plymout

h Harbo r locate d i n Plymouth , Massachusetts ; Tinkham' s Garag e i n Londonderry , Ne w Hampshire ; an d Gilso n Roa

d i n Nashua, Ne w Hampshire
. Al l fou r site s ar e bein g handle d unde r on e enforcemen

t effort
. CE C firs t purchase d th e parcel o f

lan da t th e Sit e i n November , 1974
. Th e propert y wa s developed b y themto handle , store , an d incinerat

e chemica

l wastes
. These activitie s occurred frequentl y a t th e Sit e betwee n 197 4 an d November , 1980 when operation s a

t th e Sit e cease d after th e MassDE

P (then calle dth

e Departmen

t o f Environmenta

l Qualit y Engineering ) revoke d CEC' s Wast e License , citin g documen

t falsificatio n an

d othe r wast e reportin g violations
. Ove r 70 0 drums an

d approximately 155,00

0 gallon s o f

liqui dwast

e an d sludge i n bul k storag e wer e lef t behin d on-sit

e b y CEC
. Betwee

n 198 0 an d 1982 , MassDE

P an d EP A conducted Sit

e inspections , performe dsampling an d analyse s an

d confirme dth

e presenc e o f chemica l contaminatio n a

t th e Site
. Severa

l tanks an d drums wer

e als o observe

d t o b e leaking
. I n orde

r t o alleviat

e th e proble mo f leakin g contaminatio n an d waste s lef

t on-site , th

e MassDE

P performe daremova

l action
. I n Octobe

r 1982 , MADEP' s contractor , Je t Lin e Services , Inc. , remove d approximately 155,00

0 gallon s o f

sludge an

d liqui dwaste s tha

t wer e stored i n tanks an d approximately 71 1 drums fro mth e Site
. A subsequen

t remova l wa s conducted b y th

e agrou p o f Potentiall y Responsibl

e Partie s (th

e "PR P Group" ) i n Junel988
. Th

e PR P Grou p removed th

e bul k contents o f

a n underground tank , a septic tank , 3 tanke

r trailer s an

d smal l (5 gallo n o

r less ) containers fro m laborator y an d storag e area s a t th e Site
.


### B . SUMMAR

Y O F TH E MO M REMED Y Th e RO D fo r

th e CE C Sit e wa s signed b y EP

A o n Marc h 31 , 1988
. Th e RO D separate d th e cleanu p plan fo r

th e Sit e int o tw o Operabl

e units ; Managemen

t o f Migratio n (MOM ) fo r

groundwate

r an d Sourc e Contro l fo r

soils
. Thi s ES D onl y pertain s t o th

e MO M portio n o f

th e remedy
. 1 . Managemen

to f Migratio n Th e MO M portio n o f

th e remed y include datwent

y yea r groundwate

r monitorin g progra mt o assur

e tha t contaminatio n abov

e th e Maximu mContaminan t Level s (MCLs ) di dno t

migrat e off-site , an

d t o als o assur

e tha t contaminan

t level s on-sit

e naturall y attenuated
. Th

e 198 8 RO D estimated tha t groundwate

r cleanu p targe t levels , base

d o n th e ingestio n o f

on-sit e groundwater , woul db

e achieved withi n 1 5 t o 20 years . Th e las t yea r o f groundwate

r sampling , th

e yea r 20 groundwate

r samplin g event , wa s complete d i n Septembe

r o f 2012
. Except

fo r arsenic , al l contaminants o f concer n currentl y me

t MCLs
. Howeve

r becaus e th e groundwate

r a t th e sit e i n n o longe r considered adrinkin g wate r aquifer , th

e requiremen

t t o reac h MCL s i s n

o longe r applicabl e nor

relevant
.Th e managemen

tof migratio n remed y als o require d tha tinstitutiona

l control s b e place d o n th e propert y t o restric tth e us e of groundwate

r a tth e Site . Th

e institutiona

l control s wer e recorde d wit h th e Registr y of Deed s i n Septembe

r o f 199 1 an d remai n in place.
III . BASI S FO R TH E DOCUMEN T Thi s ES D i s bein

g issue d t o explai n a modificatio

n t o th e selecte d cleanu p levels a s se t fort h in th e Marc h 31,1988 , RO D fo

rth e Site . Th e modificatio

n describe

d i n thi s ESD , reflect s th e curren tMC P groundwate

r classification fo

rwast e site s i n th e Commonwealth

. Th e curren tgroundwate

r classification prompt

s a chang e in th e Site relate d cleanu p levels . Th

e propose d modification

s t o th e MO M remed

y describe

d i n thi s ES D wil l still b

e protectiv

e of bot h huma n healt h an d th e environment

. Th e EP A Ris k Assessmen

tInformatio

n Syste m wa s use d t o recalculat

e th e risk s of arseni c an d 1 , 4-dioxan

e fo ra standar

d recreationa

l receptor . Th e cance r risk fo ra recepto r expose d t o arseni c fro m childhoo

d throug h adulthoo

d fo ra tota l o f 3 0 year s wa s 5 x 10' 6 , whic

h i s withi n EPA' s acceptabl

e huma n healt h risk rang

e o f 1 x 10' 6t

o 1 x 10- 4. Wit h regard s t o 1 , 4-dioxane

, th e cance r risk fo ra recepto

r exposur e fro m childhoo

d throug h adulthoo

d fo ra tota l of 3 0 year s wa s 4 x 10"8 , whic h i s well belo

w EPA' s acceptabl e risk rang

e of 1 x 10' 6t

o 1 x 10" 4 . Lastly , a n evaluatio

n o f ecologica l risk du e t o exposur e o f aquati c organism

s t o arseni c an d 1 , 4-dioxan

e i n Sit e groundwate

r tha tma y emerg e int o surfac e wate r i n th e wetland s t o th e wes tof th e Site , indicate

s tha tther e i s n o actionabl

e risk eve n i f ther e wer e n o dilutio n o f th e maximu

m concentration

s of arseni c an d 1 , 4-dioxan

e o n th e Site , IV . DESCRIPTIO N O F SIGNIFICAN T DIFFERENCE S Th e propose d modification

s t o th e remed y ar e summarize

d below . Origina l Remed y fo rth e Managemen

to f Migratio n Operabl e Uni t Th e origina l remed y fo rth e MOM Operabl

e Uni ti s describe

d i n detai l i n Sectio

n II.B. l of thi s document

. Modifie d Remed y Th e purpos e of thi s ES D i s t

o modif y onl y th e MO M portio

n of th e remed y b y acceptin g th e recen tgroundwate

r reclassification , an

d consequentl

y modifyin

g th e cleanu p levels fo

rth e Site . I n orde r t o determin

e th e appropriat

e groundwate

r classification an

d groundwate

r cleanu p levels , i n Octobe

r of 2012 , MassDEP complete d a ne w groundwate

r us e an d valu e determinatio

n specific t

o th e Cannon

s Engineerin

g site. Thi s evaluatio

n determine d tha tgroundwate

r beneat h th e Sit e i s actuall

y locate d withi n a GW- 2 an

d GW- 3 groundwate

r classification area

. Ther e i s n o ingestio n o f groundwater; therefore

,MCLs , whic h ar e appropriat

e fo r a GW- 1 aquifer

, ar e n o longe r applicabl

e o r appropriat

e t o groundwate

r a tth e Site. Rou x Associates , Inc. , consultan tt o th e PRPs , indicate

d i n a memorandu

m t o EP A (Rou x Associates , Inc. , 2010 ) tha tth e GW- 1 are

a sout h of th e Sit e i s no treceivin g contaminate

d groundwate

r fro m th e Site. This opinio

n wa s supporte

d bot h b y th e hydrolog y a tth e Sit e an d distanc e fro m th e Site. Th

e Sit e i s locate

d abou t0. 4 mile s fro m th e boundar

y of a Zon e II . Thi s Zon

e I I boundar

y i s i n a hydraulicall

y cross gradien tlocatio n relativ e t o th e Site, an d therefore

, groundwate

r a tth e Sit e i s flowin

g awa y fro m th e Zon e I I an d ultimatel

y dischargin

g int o th e freshwate

r wetland s i n th e wester n par tof th e Sit e an d beyon d t o th e west . Groundwate

r ha s bee n demonstrate

d t o flow i n thi

s directio n fo r ove r 2 0 year s base d o n groundwate

r monitorin

g a tth e Site . Th e yea r 20 , 1 9 & 1 8 annua l groundwate

r monitorin

g report s fro m th e las tthre e year s of annua l groundwate

r sampling

, demonstrate

s tha tal l remainin

g contaminant

s of concer n a tth e Sit e ar e protectiv

e of EPA' s huma

n healt h an d ecologica

l risk values . Furthermore

, thoug h th e "Metho d I " standard

s outline d in th e Massachusett

s Contingenc

y Pla n (MCP ) ar

e no tconsidere

d Applicabl

e o r Relevan

tan d Appropriat

e requirement

s (ARARs ) unde

r CERCLA , i

ti s importan

tt o not e tha tgroundwate

r als o currentl y meet s th e GW- 2 an

d GW- 3 standard

s unde r th e MCP . Annua l groundwate

r monitorin

g report s showin g dat a collecte d in th e 18 th , 19 th , an

d 20 t hyea r of monitorin

g provide s th e dat a whic h support s tha tth e concentration

s of al l contaminant

s of concern s currentl y mee tth e MC P GW- 2 an

d GW- 3 standards

. I n addition

, th e contaminan

tlevels in thes

e thre e year s of monitorin

g d o no texcee d EPA' s rang

e fo r unacceptabl

e risk s t o huma n healt h an d th e environment

. Se e attachmen

t2 fo r EPA' s determinatio

n of protectivenes

s fo r bot h huma n healt h an d th e environment

. Summar y o f Cost s Ther e ar e n o additiona

l cost s associate

d wit h thi s 2013 ESD . V . SUPPORTIN G AGENC Y COMMENT

S Th e Stat e of Massachusett

s (MassDEP) ha

s participate

d wit h th e EP A i n reviewin

g th e modification

s t o th e groundwate

r classification an

d cleanu p levels describe

d herein , an d concu r wit h thi s ESD . Se

e attachmen

t3 fo r th e concurrenc

e lette r fro m th e MassDEP . VI . STATUTOR

Y DETERMINATIONS EP A believe

s tha tth e modifie d remed y a s state d i n thi s ES D remain

s protectiv

e of huma n healt h an d th e environment

, complie s wit h all Federa

l an d Stat e requirement

s tha tar e applicabl

e o r relevan tan d appropriat

e t o thi s remedia

l action, meet

s th e remedia l actio n objective

s specifie d in th e 198 8 ROD , an

d i s cost-effective .VII . PUBLI C PARTICIPATIO N COMPLIANC E

In accordanc

e wit h Sectio n 117(d ) o f CERCL A an

d Sectio n 300.825(a

) of th e NCP , th

e ES D an d supportin

g documentatio

n shal l becom e par tof th e Administrativ

e Recor d fo r th e Site. Thi s ES D an

d th e Administrativ

e Recor d ar e availabl e fo r publi c revie w a tth e location s an d time s liste d i n Sectio

n 1(E ) above . A publi

c notice , whic h summarize

s th e modificatio

n t o th e remed y a s se tfort h i n th e ES D shal

l b e publishe

d i n a loca

l newspape

r of genera l circulatio

n followin g th e signin g of thi s ESD . VIII . DECLARATIO N Forth e foregoin

g reasons, b

y m y signatur

e below , I approv

e th e issuanc e of thi s 2013 Explanatio

n of Significan

tDifference

s fo r th e Cannon s Engineerin

g Superfun

d Sit e locate d i n Bridgewater

, Massachusett

s an d th e change s an d conclusion

s state d therein .

Offic e o f S^itejRemediatio

n an d Restoratio

n USEP A Ne

w Englan d - Regio n 1 5 Pos tOffic e Square

, Suit e 10 0 Boston , M A 02109-391 2

Attachmen

t1 Attachmen

t2 Attachmen

t3 -MassDE P Groundwate r Us e an d Value Determinatio

n

- Cop y of Marc h 2013 EP A memorandu

m

- MassDEP Concurrenc

e Lette r

### Attachmen t1 - MassDEP Groundwate r Us e an d Valu e Determinatio

nff Commonwealt h o f Massachusett s Executiv e Offic e o f Energ y & Environmenta l Affair s 

# Departmen t o

f Environmenta l Protectio n On e Winte rStree t Boston , M A 0210 8 •617-292-550 0
DEVA L L PATRIC K Governo r RICHAR D K

. SULLIVA N JR

. Secretar y TIMOTH Y P

. MURRA

Y Lieutenan t Governo r KENNET H L KIMMEL L Commissione r
Octobe r23 , 201 2 Derric k Golden , Remedia l Projec t Manage r U S EP A Regio n 1 Mai l Cod e OSRR07- 4 5 Pos t Offic e Square , Suite 10 0 Boston , M A 02109-391 2 Subject : Cannon s Engineerin g Corporatio n Superfun d Site , Bridgewater , Massachusett s

Groundwate rUs e an d Valu e Determinatio n Dea rDerrick : Attache d pleas e fin d th e Groundwate rUs e an d Valu e Determinatio n prepare d b y th e Departmen t (MassDEP ) fo rth e Cannon s Engineerin g Corporatio n Superfun d Sit e locate d i n Bridgewater , MA

. Thi s Us e an d Valu e Determinatio n wa s develope d b y Mass , pursuan t t o MO A betwee n EP A an d MassDE P an d consisten t wit h EPA' s Groundwate rUs e an d Valu e Determinatio n Guidance

. I n determinin g th e us e an d valu e o f th e groundwate ri n th e vicinit y o f th e Cannon s Bridgewate rSite , w e referre d t o th e aquife rclassificatio n containe d i n th e Massachusett s Contingenc y Pla n (MCP)

. Th e classificatio n i n th e MC P give s consideratio n t o al l o f th e factor s i n th e Us e an d Valu e Guidance

. Enclose d wit h th e Us e an d Valu e Determinatio n i s th e GI S 21 E Resourc e ma p (0. 5 an d 1 mil e radii ) use d t o develo p th e Us e an d Valu e Determination

. Thi s map s provide s a variet y o f information , includin g th e USG S yiel d classification , th e location s o f publi c wate rsupplie s an d zone s o f protection , an d area s o f sensitiv e ecologica l resources . I f yo u hav e an y question s regardin g thi s letter , pleas e fee l fre e t o contac t m e a t 292-5697

. Ver y trul y yours ,

Ja y Naparste k Deput y Divisio n Directo r Thi s Informatio n i s availabl e i n alternat e format

. Cal l Michell e Waters-Ekanem , Diversit y Director , a t 617-292-5751

. TDD # 1-866-539-762 2 o r1-617-574-686 8 MassDE P Website : www.mass.gov/de p Printe d o n Recycle d Pape r 

### SDM S Do c I D 52401 0GROUNDWATE RUS E AN D VALU E DETERMINATIO N Cannon s Engineerin

g Superfun

dSite , Bridgewater , M A October , 201 2
Pursuan t to th e Memorandu

mo f Agreemen

t (MOA ) betwee

n th e EP A an dMassDE

P concernin

g Groun dWate r Us e an dValue Determinations , an dconsisten

t with EPA' s 199

6 Fina l Groun d Wate r Us e an dValue Determination Guidance , th e Departmen

t ha s develope

daUs e an dValue Determination o f

th e groundwate

r beneat h an di n th e vicinity o f

th e Cannon s Engineerin

g Superfun dsit e locate di n Bridgewater , M A (th e "Site")
. Th

e purpose o f

th e Us e an dValue Determination i s to identif y whethe r th e loca l are agroundwate

r i s o f high , medium , o

r lo w us e an dvalue
. Thes

e ar e designations containe

di n EPA' s guidance
. I n th e developmen

t o f thi s Determination , a

s agree dt o i n th e M O A , th

e Departmen

t ha s appliedth

e criteri afo r

groundwate

r classificatio n promulgate

di n th e Massachusett

s Contingenc

y Pla n (MCP)
. Th

e classificatio n containe di n th e MC P consider

s criteri asimila

r to those recommende

d i n EPA' s Us

e an d Value Guidance
. Th e Department

s recommendatio

n fo r th e groundwate

r a t th e Cannon s Engineerin

g Bridgewate

r sit e i s mediu mus e an dvalue
. Thi s recommendatio n i s base d on th e non-drinkin g wate

r status o f th e groundwate

r beneat h an di n th e immediat

e vicinity o f

th e site , th e presenc e o f curren t an d potentia l drinkin g wate

r sourc e area s off-sit e bu

t withi n th e stud y area , th e presenc e o f sensitiv e ecologica l resources i n th

e immediat

e vicinity o f

th e site , an dth e location o f

th e sit e withi n a Stat e designate

dAre ao f

Critical Environmenta

l Concer n (ACEC)
. Thi s recommendatio n i s explaine di n mor e detai l below
. Fo r th e purposes o f

thi s Determination , th

e groundwate

r unde r evaluation i s define da

s tha t underlying th

e Sit e an dth e surroundin

g are aextendin

g i n atw o mil e radiu s fro mth e centra l portio n o f th e Site
. Th e Cannon s Engineerin

g sit e i n Bridgewate

r occupie s approximatel

y 6 acre s o f lan dbetwee n Rout e 2 4 an dFirs t Street
. Operations a

t th e sit e tha t includedth

e transportation , storage , an d incineration o f

hazardous wastes resulte di n contamination o f

on-sit e soils , sediments , buildings , groundwater

, an dsurface waters
. Contaminant s o f concer n includedvolatil e organi c compound

s (VOC) , polychlorinate dbiphenyl s (PCB) , polycycli c aromati c hydrocarbon s (PAH) , pesticides , an dmetals
. Groundwate

r beneat h th e sit e containe

dVOC s includin g toluene , a s wel l a s heav y metals
. Th e complete

dsourc e contro l portio n o f

th e cleanu p ha d severa l components , includin g on-sit e therma l desorptio

n o f uplan dare aan dwe t are asoil s tha t wer e contaminate

dwith VOCs , an

doff

sit e incineration o f

PCB s contaminate

dsoil s i n excess o f

9 part s pe r millio n (ppm)
. Th e managemen

t o f migratio n portio n o f

th e clea n u p includedrestrictin g th

e us e o f groundwate

r a t th e sit e b y th e us e o f adee drestriction/institutiona

l controls , installin g additiona l monitorin g wells , an dimplementin

g alon g ter

mgroundwate

r qualit y monitorin g progra

mto observ

e th e presence, distributio n an

dmigratio n o f

contaminants
. Th

e Recor do f Decision anticipatedtha

t remova l an dtreatmen

t o f contaminate

dsoil s woul deliminat

e source s o f further groundwate

r


### SDM S Do

c I D 524009contaminatio n an d tha tth e residua l lo w level s o f contaminatio

n foun d i n th e groundwate

r woul d mee tdrinkin g wate r standard

s throug h monitore

d natura l attenuatio

n ove r 2 0 years. Long-ter m groundwate

r monitorin

g bega n i n 1991 . Annua

l samplin g wa s require d t o b e conducte d fo r a tleas ttwent y year s t o demonstrat

e an d ensur e tha tmonitore d natura l attenuatio

n wa s occurring

. Th e 20t h annua l samplin g even twa s complete d i n Septembe

r 2010 . Analytica

l result s indicat e tha tal l VOC s hav

e me tthei r respectiv

e MCLs . However

, th e 200 9 analytica

l dat a fo r inorganic

s showe d tha t7 ou to f 2 4 groundwate

r sample s exceede d th e MC L fo r arsenic . Th e arseni c exceedence

s ar e isolate d an d appea r t o b e confine d t o withi n th e sit e boundaries

. I t i s suggeste d b y th e partie s conductin

g th e cleanu p tha tth e arseni c exceedence

s ar e indicativ

e o f a reducin g environmen

tassociate d wit h th e chlorinate

d organic s contamination

. The y anticipat e tha tth e arseni c wil l becom

e adsorbe d t o aquife r matri x material

s and/o r precipitat

e ou to f solutio n a s th e aquife r graduall y return s t o a mor e oxidize d stat e no w tha tVO C concentration

s hav e bee n significantl

y reduced

. EPA' s 2010 Five Yea

r Revie w recommende

d a n additiona

l roun d o f groundwate

r samplin g fo r arseni c b e conducte

d prio r t o th e nex tFiv e Yea r Revie w (2015) . Th e lan d us e surroundin

g th e Sit e i s mostl y ligh tindustria

l wit h som e residentia

l areas . Th e neares tresidenc e i s locate d 1/ 8 o f a mil e fro m th e site . Th e closes tmunicipa

l drinkin g wate r wel l is locate

d i n Raynham

, approximatel

y 1 mil e southwes

to f th e site . Th e Bridgewate

r municipa l Tow n well s ar e locate d 2. 6 mile s eas to f th e site . Sensitiv

e ecologica

l area s ar e locate d nea r th e sit e an d includ e wetlan d area s t o th e eas tan d wes to f th e site , an d Lak e Nippenicke

tt o th e west . Th e sit e i s withi n a Massachusett

s designate

d Are a o f Critica l Environmenta

l Concern , th e Hockomoc

k Swam p ACEC . Th e aquife r immediatel

y beneat h th e Sit e i s classifie d a s a lo w yiel d aquife r b y th e Unite d State s Geologica l Survey . Thi s groundwate

r is no tconsidere

d t o b e a Curren

to r Potentia l Drinkin g Wate r Sourc e Are a (MC P Categor

y GW-1 ) an

d i s categor y GW- 3 unde r th e MCP. Drinkin

g wate r standard

s d o no tappl y a tGW- 3 areas . However

, ther e ar e bot h Curren tan d Potentia l Drinkin g Wate r Sourc e Area s withi n th e stud y area . Approximatel

y l A mil e t o th e eas to f th e sit e i s a mediu m yiel d aquife r a s define d b y th e USGS . Thi

s i s a categor

y GW-1 , Potentia

l Drinkin g Wate r Sourc e Area. Approximatel

y 1/ 3 mil e t o th e southwes

tis anothe

r mediu m yiel d aquifer , an d th e edg e o f a delineate

d Zon e I I fo r a serie s o f Raynha m municipa

l wells . 1.

3 mile s t o th e eas ti s th e edg e o f a delineate

d Zon e I I fo r a serie s o f Bridgewate

r municipa

l well s tha tar e locate d approximatel

y 2. 6 mile s eas to f th e Site. Thes

e area s ar e categor y GW- 1 groundwater

s an d considere

d t o b e Curren to r Potentia l Drinkin g Wate r Sourc e Areas. Stat

e an d federa l drinkin g wate r standard

s appl y t o thes e areas . An y groundwate

r migratin

g fro m th e sit e shoul d mee to r excee d Stat e an d federa l drinkin g wate r standard s (MCLs/GW-1 ) i f

an d whe n i treache s an y o f thes e areas . In summary

, groundwate

r directl y beneat h an d i n th e immediat

e vicinit y o f th e sit e i s categor y GW- 3 an d GW- 2 an

d no tconsidere

d a sourc e o f drinkin g water . Drinkin g wate r standard

s ar e no tdirectl y applicabl

e i n thes e areas . However

, som e groundwate

r area s outsid e th e sit e boundar y an d th e immediat

e vicinit y o f th e site , bu twithi n th e stud y area , ar e categor y GW- 1 an d shoul d b e evaluate d a s drinkin g wate r sourc e areas . Drinkin g wate r standard

s d o appl y i n thes e locations

. Finally , ther

e ar e sensitiv e environmenta

l receptor s withi n th e stud y area .Decision s o n final remed

y an d protectivenes s shoul

d includ e evaluation o f

th e impact s t o thes e areas . Definition s o f

th e variou s groundwate

r categorie s i n th

e MC P ar e summarize

d a s follows : GW- 1 Th e groundwate

r i s locate d withi n a n are atha t i s currentl

y use d fo r drinkin g wate

r o r i s considere d to b e alocation tha

t ha s th e potentia l t o b e develope

d fo r publi c wate

r supply
. Stat

e an d federa l drinkin g wate

r standard s ar e directly applicabl

e t o thes e areas . GW- 2 Thi s designatio

n addresse

s area s wher e ther e i s apotentia

l fo r migratio n o f

vapor s fro m groundwate

r t o occupie d structures
. Th

e classificatio n applie s to location s wher e groundwate

r ha s a n averag e annua l dept h o f 1 5 fee t o r les s an d wher e ther e i s a n occupie d buildin g o

r structur e withi n a3 0 foo t

surface radiu s o f

tha t groundwater
. I n thes

e cases , evaluation o f

ris k shoul dinclud e indoo r ai r exposures throug

h contaminan

t vapo r intrusion
. GW- 3 Thi s designatio

n consider

s th e impact s an d risks associate

d with th

e discharg

e o f groundwate

r t o surface wate

r an d therefor

e applie s to al l groundwate r i n th e Commonwealth , regardles s o f

an y othe r categor y i t ma y als o fal l within
. Evaluation o f ris k shoul d includ e huma n healt h an d environmenta

l exposur e resulting fro mdischarg e o f contaminate

d groundwate

r to surface wate

r bodies
. Considerin

g thes e classifications , evaluation o f th e groundwate

r risks remed

y performance a

t th e Cannon s Bridgewate

r sit e shoul d include , bu

t i s no t limite dto , th

e following : Huma n Health : a ) vapo r seepag e int o buildings , b ) migratio n o f

contaminant

s to GW- 1 area

s off-site , c ) us e o f th e wate r i n industria

l processes , d) excavatio

n int o groundwate

r (i.e. , worke

r exposure) , e ) potentia l exposure

s resulting fro mdischarg

e t o surface wate

r (e.g
. wading , recreation , fishing). Ecological : a ) ecologica

l risks pose

d b y discharg

e o f groundwate

r t o nearb y wetlands an

d Lak e Nippenicket
. I n light o f th e us e an d valu e factor s containe

d i n EPA' s guidanc

e an d simila r criteri aestablishe

d i n th e MC P tha t wer e examine

d i n thi s determination , th e Departmen

t recommend

s amediu

m us e an d valu e fo r th e Sit e groundwater
.US E AN D VALU E FACTOR S CANNONS ENGINEERIN G CORP . SIT E j SITE-SPECIFI C DETERMINATIO N
1. ) Quantit y Low Yiel d o n an d i n immediat

e vicinit y of site ; Area s o f mediu m an d hig h yield off-sit

e bu t withi n 1/ 3 mil e 2. ) Qualit y Groundwate r no timpacte d b y th e sit e is of goo d qualit y t o th e bes to f ou rknowledge

. Municipa

l well s ar e locate d approximatel

y 1 mil e southwes

t of th e site ; Delineate

d Zon e 1 l' s ar e locate d southeas tan d wes tof th e site . 3. ) Curren tPubli c Wate r Suppl y Well s Municipa l well s an d Wellhea

d Protectio

n Area s ar e locate d withi n Stud y Are a

4. ) Curren

tPrivat e Drinkin g Wate r Suppl y Well s N o know n privat e well s withi n Stud y Are a 5. ) Likelihoo

d an d Identificatio

n of Futur e Drinkin g Wate r Us e Groundwate r directl y beneat h an d i n th e immediat e vicinit y o f th e sit e is notbelieve

d t o b e suitabl e fo rpubli c wate r suppl y developmen

t Aquife r t o th e S E is alread

y i n us e fo rpubli c wate r supply ; aquife

r t o th e wes tha s potenria l fo r wate r suppl y development

; N o know n curren t plan s fo rthis . Stud y are a consist s of agricultural

, residential

, an d industria

l developmen

t Approximatel

y 80 0 peopl e liv e withi n a 1 mil e radiu s of sit e
6. ) Othe r Curren to rReasonabl

e Expecte d Groun d Wate r Us e i n Revie w Are a • Unkow n

7.) Ecologica

l Valu e Shallo w groundwate

r discharg e t o drainag e canal s an d nearb y wetland s t o th e sout h an d wes t Deepe r groundwate

r discharg e t o souther n portio n of Hockomoc

k Swam p Potentia l receptor s of contaminate

d groundwate

r ar e aquati c an d terrestria

l biot a inhabitin

g th e wetland s (discharg

e are a fo rshallo w water ) Endangere

d specie s habita texist s on-sit e



### SDM S Do c I D 52401 18.) Publi c Opinio nMa

p Outpu t Pag e 1 o f 1 

## MassDE P - Burea u o f Wast e Sit e Cleanu p MC P Numerica l Rankin g Syste m Map : 50 0 fee t & 0. 5 Wil e Radi i

ft£AQft3 M A Coorthft*!* * 

# n MassDE P

SDM S Do c I D 52400 8SDM S REPOSITOR Y TARGE T SHEE T U S EPA Ne

w Englan d Superfun d Documen

tManagemen

tSyste m / RCR A Documen

tManagemen

tSyste m Nativ e File s Targe

tShee t

SDM S Documen t

I D # : 52400 8 Site Name : Canno n Engineerin g Corp
. . Fil e Type(s ) Attache d(examples : Exce l file o r jpg) : JP G Documen t

Typ e thi s Targe t

Shee t Represents : [ ] Map [ X ] Photograp h [ ] Graph/Char t [ ] Vide o [ ] Compac t Dis c [ ] Other

(Specif y below ) Descriptio n o r

Comments : _MC P Numerica

l Ranking Syste

mMan : 50

0 fee t an d0. 5 Mil e Radii T o view th

e attached files, ope

n th e "Attachmen

tPanel "

- i n th e lef tside pane

l of thi s window . * * Pleas e not e t o vie w attachment

s th e softwar e correspondin

g with th e specifie dfil e typ e i s necessary . * *
Fo r an y additiona

l assistanc e pleas e contac t th e EP A Ne w Englan dOffic e o f Sit e Remediatio

n an dRestoratio

n Record s an dInformatio n Center

Telephon e (617)91 8 144

0

### Attachmen t2 - Cop y o f Marc h 2013 EP A risk memorandu mMEMORANDU M

To : From : Date : Subject : Derric k

Golden Richar dSugat t Marc h 21,201 3 Residua l ris k evaluatio n fo r

Cannons Engineerin g SuperfundSite , Bridgewater , M A Th e purpos e o f

thi s memorandu

mi s t o evaluat

e th e potentia l fo r huma n healt h an d ecologica l ris k du e to residua

l contaminants i n groundwate r a t th e Cannons Engineering Superfun dSit

e i n Bridgewater , MA
. A s documente dbelow , i t

i s concludedtha

t ther e i s n o actionable huma

n healt h o r environmenta

l ris k du e to residua

l contaminants i n groundwate

r a t th e Site
. O n Octobe

r 23 , 201 2 Mas s DE

P conductedane

w groundwate

r us e an dvalue determinatio n specificall y fo r th e Cannons Engineerin g Bridgewate r Superfun dSite , an

d thi s evaluatio n determinedtha t groundwate

r a t th e Sit e i s actually locatedwithi n GW- 2 an dGW- 3 groundwate

r classificatio n areas . Th

e Sit e i s n o longe r consideredto b

e withi n aGW- 1 area . A s aresult o f thi s reclassification , drinkin g wate r standard s suc h a s MCL s ar e n o longe r applicabl e o

r appropriat

e fo r groundwate

r cleanu p goals
. A s show n o n Table 1 , th

e lates t availabl e groundwate

r dat a(2009 , 2010 ) indicat

e tha t arseni c an d1 , 4-dioxan

e ar e th e onl y tw o groundwate

r contaminants tha

t exceede d huma n healt h standard

s o r guidance
. Arseni c a

t amaximu mconcentratio n o f 40 ug/ L exceede d th e MC L an

dMassachusett

s MCL , bot

h 1 0 ug/L
. 1 , 4-dioxan

e a t amaximum concentratio n o f

4. 9 ug/ L exceede

d th e Massachusett

s Drinkin g Wate

r Guidelin e o f

3 ug/L
. Since th

e GW-1 , MCL , MMCL , an dMassachusett

s Drinkin g Wate

r Guidelin e ar

e no t applicabl e o

r appropriate , an

dus e o f groundwate

r a t th e Sit e fo r drinkin g wate

r i s no t reasonabl y foreseeable , ther

e i s n o curren t o r futur e completedhuma

n healt h exposur e pathwa y t o groundwater , an

dtherefore , n

o huma n healt h risk
. Althoug h GW- 2 an

dGW- 3 standard

s ar e no t consideredapplicabl e o

r relevan t an d appropriat

e requirements (ARARs ) unde r th e Superfun dProgram , I hav e reviewe dsite

relate ddat

aagainst these stat

e standard

s a s anothe r basi s o f comparison
. Table 1 demonstrate s tha

t th e maximu mconcentration s o f al l detecte

d chemical s d

o no t excee d these standards
. GW- 2 standards ar e designe dt o b e protectiv e against

vapo r intrusio n o f volatil e organi c chemical s (VOCs ) fro mgroundwate r int o buildings
. Th

e absenc e o f GW

2 exceedances supports th e conclusio n tha

t vapo r intrusio n i s no t

o f concern . Thi s conclusio n i s als o supportedb y th e conclusio n i n th

e most recen t Fiv e Yea r Review Repor t (EPA , 2010 ) tha

t ther e wa s n o complet e vapo r intrusio n pathwa

y base d o n Sit e conditions , a

s wel l a s conservative Johnso

n & Ettinge

r modelin g Similarly , th

e absenc e o f GW- 3 exceedances supports th e conclusio n tha

t ecologica

l impacts t o surfac e wate

r ar e unlikel y when Sit

e groundwate

r reaches surfac e water
. Al l groundwate

r i n Massachusett

s i s classifie da

s GW-3 , an

dth e GW- 3 standards ar

e designe dt o b e protectiv e o f

aquatic organisms after

10-fol ddilutio n o f

groundwate

r a s i t emerges into surfac e water
.Rou

x Associates , Inc. , consultan t t o th e PRPs , indicate di n amemorandu mt o EP A (Roux Associates , Inc. , 2010 ) tha t th e GW- 1 are

asout h o f th e Sit e i s no t receivin g contaminated groundwate

r fro mth e Site
. Thi s opinio n wa

s supportedbot

h b y th e hydrolog y a

t th e Sit e an ddistance fro mth

e Site
. Th e Sit e i s locatedabou

t 0. 4 mile s fro mth

e boundar y o f a Zon e II
. Thi s Zon

e I I boundar

y i s i n ahydraulicall y cross-gradien t locatio n relativ e t o th e Site , an dtherefore , groundwate

r a t th e Sit e i s flowin g awa

y fro mth e Zon e I I an d ultimatel y discharging int o th e freshwate

r wetland s i n th

e wester n par t o f th e Sit e an d beyon dt o th e west
. Groundwate

r ha s bee n demonstrate

dto flo w i n thi s directio n fo r ove r 2 0 year s base d o n groundwate

r monitorin g a

t th e Site
. T o addres s th

e potentia l concer n tha t groundwate

r a t th e Sit e migratin g t o th

e off-Sit e wetland s ma

y pose ahuma

n healt h risk , thi s memorandu

mevaluate s th

e huma n healt h ris k t o off-Sit e recreators a

s describedbelow : Althoug h unlikely , i t

might possible tha

t peopl e who explor

e th e off-Sit e wetland s to th

e west o f th e Sit e ma y contact surfac e wate

r comprisedi n par

t o f groundwate

r fro mth e Site
. Th e ris k calculator

a t th e Ris k Assessmen

t Informatio n Syste

m (http://rais.ornl.gov/cgi-bin/Drg/RIS K search?select=chem

) wa s use d to calculat

e th e risk s o f arseni c an d1 , 4-dioxan

e fo r astandar drecreationa

l receptor , usin g th

e undilute d maximu mconcentratio n o f 40 ug/ L arseni c an d4. 9 ug/ L o f 1 , 4-dioxan

e i n Sit e groundwater
. Standar dexposur

e assumption s fo r

derma l contact an d incidenta

l ingestio n o f

surfac e wate r fo r recreationa

l adult s an

dchildre n include dingestio n o f 0.0 5 L/day , exposur

e tim e o f 1 hour/day , exposur

e frequenc y o f

4 5 days/year, exposur

e duratio n o f

3 0 years , ove

r a lifetim e o f

7 0 years . A s show

n i n th e attache dprintou t

fo r 4 0 ug/ L arsenic , th

e non cance r Hazar dQuotien

t fo r bot h adults an

dchildre n wa

s les s tha n 1 , indicatin g tha

t non carcinogeni c effect s ar

e unlikely
. A s show

n i n th e attache dprintou t

fo r arsenic , th

e cance r ris k fo r arecepto r expose dfro mchildhoo dthroug h adulthoo d fo r atota l o f 3 0 year s wa s 5 x 10' 6 , whic h i s withi n EPA' s acceptabl e ris k rang e o f 1 x 10" 6 to 1 x 1 0
. A s show n i n th e attache dprintou t

fo r 4. 9 ug/ L o f 1 , 4-dioxane , th

e non-cance

r Hazar d Quotien t fo r bot h adult s an

dchildre n wa

s les s tha n 1 , indicatin g tha

t non-carcinogeni c effect s ar e unlikely
. A s show

n i n th e attache dprintou t

fo r 1 , 4-dioxane , th

e cance r ris k fo r arecepto r exposur e fro mchildhoo dthroug h adulthoo dfo r atota l o f 3 0 year s wa s 4 x 10" 8 , whic h i s wel l belo w EPA' s acceptabl e ris k range o f 1 x 10" 6 to 1 x 10' 4
. T o addres s th

e potentia l concer n tha t arseni c i n groundwate

r a t th e Sit e migratin g to th

e off-Sit e wetland s ma

y pose a n ecologica

l risk , i t i s sufficien t

conclud e ther e i s n o potentia l ecologica

l ris k becaus e th e National Recommende

dWate r Qualit y Criteri afo r protectio n o f

aquatic life fo r

chroni c exposur

e i s 15 0 ug/

L a s th e Criteri aContinuou s Concentratio n (CCC)
. Thi s indicate s n o ris k to aquatic life becaus

e th e maximu m concentratio n o f

4 0 ug/ L i n groundwate

r a t th e Sit e i s lowe r tha n th e CCC
.Similarl y fo r 1 , 4-dioxane , th

e availabl e aquatic informatio n indicate s tha t aquatic toxicit y i s lo w an

ddoe s no t occu r a t concentration s belo w 14 5 mg/L
. Th

e 199 5 OPP T Chemica l Fac t Shee t fo r 1 , 4-dioxan

e (EPA , 1995 ) (http://www.epa.gov/chemfact/dioxa

sd.txt) cite s report s describin g acut e an dchroni c toxicit y o f

1,4-dioxan

e to Pimephale s promela s (fathea

dminnows)
. Acut

e effect s occurreda

t 10,00 0 mg/ L but not a t 600 0 mg/L , whic h wa

s th e highes t n o observe dadverse effec t

leve l (NOAEL)
. A 32-da y embryo-larva

l tes t identifie daMaximu mAllowabl e Toxicant Concentratio n (MATC ) >14 5 mg/L , whic h mean

s tha t n o chroni c effect s occurred a t 14 5 mg/L
. Additiona l acut

e toxicit y studie s indicate dtha t th e 96-hou r LC5 0 valu e fo r

Lepomi s macrochiru s (bluegill ) wa s 10,00 0 pp m(10,000 mg/L ) i n fres h water , an dth e 96-hou r LC5 0 value fo r

th e fis h Menidi aberyllin ai n syntheti c seawate r wa s 6,77 7 pp m(677 7 mg/L)
. Thes e toxicit y dat

a ar e sufficien t

to conclud

e tha t th e maximu mconcentratio n o f 1 , 4-dioxan

e i n Sit e groundwate

r (4. 9 ug/L ) i s much lowe

r tha n th e level s tha

t ar e toxi c t o aquatic organisms
. Summar y an dConclusion s Althoug h th

e maximu mconcentratio n o f arseni c an d1 , 4-dioxan

e i n Sit e groundwate

r exceede d huma n healt h standard

s o r guidelines , i t

i s concludedther

e ar e n o huma n healt h risk s du e t o ingestio n o f

on-Sit e groundwate

r becaus e ther e i s n o reasonabl

y foreseeabl

e us e o f thi s groundwate

r fo r drinkin g wate

r purposes , a

s shown b y th

e MassDE

P reclassificatio n o f

groundwate

r a t th e Sit e fro mGW- 1 t o GW- 2 an d GW-3
. Ther

e ar e n o on-Sit e huma n healt h risk s du e t o vapo r intrusio n becaus

e i t wa s concludedi n th

e most recen t Fiv e Yea r Review repor

t tha t ther e i s n o completedvapo

r intrusio n exposur

e pathway
. Accordin g to availabl e data, Sit e groundwate

r move s t o th

e west rathe r tha n to th e sout h toward s th

e neares t GW- 1 area

, therefore , ther

e i s n o ris k du e to us e o f off-sit e drinkin g water
. A n evaluatio n o f huma n healt h ris k du e t o contac

t wit h arseni

c an d 1 , 4

- dioxan e i n Sit e groundwate

r tha t ma y emerg e int o surfac e wate

r i n th e wetland s t o th

e west o f th e Sit e indicate s tha

t ther e i s n o actionable ris k

eve n i f ther e wer e n o dilutio n o f th e maximu mconcentration s o f arseni c an d1 , 4-dioxan

e o n th e Site
. A n evaluatio n o f ecologica l ris k du e to exposur

e o f aquatic organisms to arseni c an d1 , 4-dioxan

e i n Sit e groundwate

r tha t ma y emerg e int o surfac e wate

r i n th e wetland s t o th

e wes t o f th e Sit e indicate s tha

t ther e i s n o actionable ris k

eve n i f ther e wer e n o dilutio n o f

th e maximum concentration s o f

arseni c an d1 , 4-dioxan

e o n th e Site
. I t i s concludedtha

t ther e i s n o actionable huma

n healt h o r environmenta

l ris k du e to residua

l contaminants i n Sit

e groundwater
. Reference s Rou x Associates , Inc
. Ma

y 21 , 2010
. Memorandu

mt o Derric k

Golde n fro mIa n Phillips , LSP , Rou x Associates , Inc
. U.S
. EPA
. 2010
. Five-Yea r Revie w Repor

t Fourt h Five-Yea

r Revie w Repor

t fo r Cannons Engineerin g Bridgewate

r Superfun dSite , Tow n o f Bridgewate

r Plymout h County , Massachusetts
. Septembe r 2010
. U.S
. EPA
. 1995
. OPP

T Chemica

l Fac t Shee t 1 , 4-Dioxane Fac

t Sheet : Suppor

t Documen

t (CA S No
. 123-9-1)
. February , 1995
. EP A 749-F-95-010a
.3 L U f O 9 O > t - r o O L O 

## 2 C O 0 J 

### u 

# • s

I/) 

## a c o

• M B 1 0 3 

### o r L U

0 ) v . U 0 5

0 5 C D a ) t n _C D

' c 3 (1 ) L ^ 3 I/ ) C

D ^ o * 3 ^ cro

_3 a ; a ; c 3 r o £ ^ ° i n < D x P •g o5 i. *"* 0

5 u C D 5 O a ? a ? a; % E u E 3 C D C x _ o u E o ) 5 ^ r o o 3 0 5
3 (/ > O Q

. X C D I/) C D C


### J a f B a : Q i > h U J h Li
- H

L U L U _C

D

c o
J *

_' ' 0 5 n 

### & 5 < C D E u 3

- o 0 5 i 0 $ 0 5 C D U 

## • g 3

< 1 0 L O O O T

—c o r o

c C D > C D o
^ 0

5 4 - C D §

. i C D C D

0 5 " D 2 1 3 " O 0 5 i C D 2 C D 0 5 

# •*— >

C 

## 1 § C D a > I " D a )

•4— » 0 5 C D T 3 ^ a ; 0 5 3 </ > O C D O ) 3

. 5 .3 , 0 5
S 3 0 5 _" O 0 ) 0 5 0 5 a ;
•4— » r -

- 0 ) F c n c 0 5

_ ^ T a c " O 0

5

^ ! c > I N E u

u .05 0 5 E ^

_ a ;
" D
" D 3 0 5 i C D O ) 0 5

"O r o 

### 5

. 9 ^ L U L U —— L L L L L L

Q 0 0


### 2 C c u > i N E u

0 5 E V
- < U " D " D 0 ) 

# •*— >

V ) 3 0 5 i C D U ) 0 5 U ' c < D i S 3 E

" D f 0

L L Q L O L O O O O ^ L O L O L O LO

0 5 0 5 C D C D > > %

-— s s— ^ c c o o 0

5 C D
o 0

5 C D 0 3 ^
C o '-t i 't i f ° g > *C D 'C D

o o

_ Q

_ Q 

### 5 $ O Q m '< D

" D O c 0 5 0 3

3 3 0 ) I/ ) O C L X J ^ ^ ^ C f > a Q L U L U 0 0 O Q 3

" D 3 (/ > O Q

. X C D 0

5 C D > % 0 5 " D
c C D 3 c r C D C D C D h i 0 5 " D >> U c C D 3 cr C D 0

5 C D > > 0 5

~o
c C D 3 c r C D C D 2 - 2 1 s Z •+ - M — 3 (/ ) O Q

. ^ X C C D p rw Q"LL C L U L U 3 V ) O Q L X C D < £ r i i L L L L L L L U L U L U C C D > C D 3 O C D E
'«•- » C D u _ 3 </ ) O Q

. X C D C U ^ C o
L U 0 0

L O C O

r o r - O C M < f N U C D C D C C D O ) C L 3 O< 0 r o > LO L O L O L O o o o o dod o o

o C O t o o o c o C O o o o 0 0 o o o 0 0 T
- C M LO o o

o o 0 0 L O o

u 

# • s

3

3 

### a

. c C 

### o r o 3 

### c r L U ( 0 u c C D > C D D o c C D > C D o c § 2 C D o

^ C D E 

## i C

D E 0 5 C O

D t o o C L X C D C D w C D i — Z J t o o Q L X Z

J t o o C L X C D

, w C c < U 5 5 C

O ^ to to ±± "D

- Q

. 2 c c

C D C D > > C D C D 1 o 1 o -t— > -t— • c c C D C D > > C D C D a s L U L U L U > c > r L U LU Z

J o r o ^ P C D c » - C D C D > C D 0 5 Z

J D O

^ C D £ r S 0 5 5
- ^ C D C D * L 0 5 C C — o5 2> > 0 5
>-* e L u * ^

_ C D C D +- > 0 5 

## i £

wc l C £ r - i r C > C £ 

# I I CD 

# •*—>

0 5 i

_ C D 0 5
C D •+- » 0 5 C C E u 0 5 4 ) C D C J 

# • e Z J t o
t o E

C J o ?
C D C J 

# • e Z J t o
t o E u IT ? C D ^

_ 0 5 C D U 

# • e Z J t o
t o C D t - • i C O 0

5 C D

< U 0 5 ft c E C J 0 5 C D k

_ 0 5 C D C J Z J t o c 1 ^ w o r o < C O Z J 05V cr C D c o
3 3 c

C D > C D Z J O CJ

)

_ c p = +- » 0 5 0 5 C D 5 "t o
" D C D

— j in v O ± * C L Z J x ~o & 5
Q L L L U L U Z J t o O C L X C D Z J " D *C

D
o 0 5 0 5 — Z J "C J

L U L U D Q E u Z J " O 0 5 1 0 5 C D C D C J Z J t o

O J

C O Z J " D 0 5 1 C D C D 0 5 -4— * c 0 5 0 0 LO 0 0

r o o OH <
B S C D C C D O l C L Ov

? g ) < D ^ O

_

- n C O 

# 6 1
c o o u L O O i L U C O

23 ® 3 U w C o u 2 3 c " S u £ c o u o C L L U o

o

< L L



### 2. 5 

### § o

o —r o r o

| E a L

U ti i J = S 3 I r o ^ C N r\ |

ai < K •0. 2 o o
= « a L

u 4

^ flj I 0 0 c o C L

O L O 

## !§>

_ E o Q c o . E u c o U u c c 0 0 £ D)
- t o O Q 01 c u o v n c u ( 0 u 

# I I E « c u C O • D
3 . £ 5 C O u o

i L U

C D O i L U r — C D rs i

c o o i L U L O TI
- T S o < z y " E £

. 2 o
_ < 2 "K a

c o C

O O i L U O C O

• = c E e n c

o V

. Q O « rT ' Q

. = Q L

U y u N 3 TO 

# n - Z • 2 c y < u 2 - £>. £ Q
= y u + ±( 0 3 u r o

C O O i L U C M L O

U C O a i E o ) Q

. - Q : = C

O O i L U h s T — rv i o

E v l I±

J ULI

co S O

—0 0 f o * f c o o O 3 E C LL

i ti l 5 I r o r o < Q rs i C

M
c • M O rs i r\

j o o 3 « g U J t y < o > C 2 «

_ U H rs i <

N 9 9 L U u a o o C M < N c b < dC D V 3 L U « R CD > r- mrO L O o o o O 0 0 o T
- o o 

## 5

U



### a c

r o 3 L U
< 0 

## u 

## a * a: r o C D

l O t o _C D ' E Z J
t o C O t j C D c g •4— » r o Z J ( 0 t o _C D
' c Z J c C D '•+- » o Z J C r E

E Z J C D C o C J t o E Z J

O C D

C D U C C O C J 

## £ I .2 

## k c o a : > h
C D a
t o - c 

### R« u r o r o u C D r o >; * o « o = J = i n 

## s » o r o t o C D c u C D S Z J t o o C L X C D O ) r o o
0 3

w 5 

### aa L U h J U J L

U < C D i

_ Z J t o o
_ Q

. + - X S §

* C O Q

_ C L C O C D
o

_ Q L O

o T T

t o o o

c C D > C D 3 O
4 ^ C D 

### S

. i > C D C D 3 O
E u Z J T J 0 3 i 0 3 0 3 C D U « § Z J t o

w u < * C O r o

" D

Z J r o i a j " S ^

_ C D J * CT 3 Z J

t o o
£ 17 ) D )

C D •4— > 5 C D 

## 5 !

^ C D C D • £ 2 £ C D 0 3 Z J t o O Q

. x C D

" D CD 

# •*—>

t o Z J 0 3 C

D C D t o Z J

_ '~o C D 0 3 w i 0 3 C D

03 •*-• C O £ 0 5 ^ 1 " D

O ) 0 0 Z J 0 3 IS 0 3 C D C O 3 > a C

O c C D > C D i N E C J
C J .0 3 0 3 E v . C D " O
" D C D •4— » t o Z J T T 0 3 i C D C O 0 3


### 5 a a 5 ^ U J u j t t i t " U C O I u c u
L L Q r o r ^ Psl

C O J Z C D > C D i N E c j

r o E ^

_ C D " D
" D C D
-•— * C O Z J T T r o i C D C O r o u * c C D C O r o 

# •*—>

3 E L L Q L O L O O O O T T L O L O L O L O

C 0 C O

C O C O 'C D 'C D

" O " D o o

_ Q X ) 

### 5 $ C D G O r

o C D

_c o C O - r

o C D > > o c o o o r

o £ 5 5

_r o C D " D Z J

" D C D C D 

## ^ ° 2 - ° j Q ^ ^ C C C 0 " t o o C L X C D 

## 5 2 D Q D D L U 3 • o C D ^

_ Z J t o o Q L X C D
C C Q L U r o C D ^ > r o

" D c C D Z J O " C D i
- r

o v - r o C

D C O C D > >

T 3 ^

D " D 

### a ? Z J t o O 3 Q

_t O X O C D C L ^ X C C D 

### « ! 

### n L U L U C J c C D D cr C D ^ * ^ ^ 2 2 Z J t o o Q

. X Z J

t o o Q

. X C D C D ^

wc

c cc T
- < D ^ c o 

## 8 c u 0 0 i n c o

r o t — o C M <
T — £
C D C D C O •*- > D Q

. L U L U L U L U4 > r o > L O L O L O L O o o o q dod o o

o t o t o o o t o t o o o o o o o o o 0 0 T T LO O o

o o 0 0 r - O L O o 

## 2 ( 0 u
3

(A 3 

### a c 

### g r o 3 CJ



### u 0 1 ^ C D C C D > C D Z J o C D E
C D

- » 3 t O 1 0 O 2 ° - Q

. X X C D C D ^ D

t o O C L X C D C c o r o "t o 17 ) r o " D <D ¥1 ¥1 £ 3 V- V C C C

D C D C D > > > C

D C D C D ^

. Q r o r o > t o t o

c c C D C D > > C D C D r o " O ] 3 c C D > C D I n 

# •»— >

c C D
C c 3 3 O O
I D I D t o r o ^ - C D C D r o r o i
- Z

J 

### 8 5

^ C D C D • £ r o r o > - ^ C D C D J * r o > u » w >

—. — 4- # 4- » C c c —

L U H I L U L U L U L U £ £ r o r o

i i c r > en ct £ % s £

wc

0 £ E r o C D C D u 3 t o t o
C O E u < D C D u 3 t o t o
C O E u "r o C D k

_ r o C D u Z J t o t o

C O r

o C D r o c u r o
c E u a ? ff r o C D u Z J 1 0 c t o o r o < C O Z J " D r o § c

C D > C D O C

O J C C D r o C D 3 t o o C D Q

. Z J x a u O + - C L 3 X " D C D r o C

D p Z J t o o Z

J > > " 5 r o r o E u 3 r o r o C D c X C D Z J C O 'C D

o j Q r o r o ^

Q L L L U U J L U L U G O C D U 

### • i t o

r o

C O ' Z J " D r o i C D C D

_ ^ r o

r o
r o C O i n o o

r o O <
f N £ S C D C C D C O 3 C L o

### u 3 0 )

V ) 

## 5

0 ) 

### o 

## a : • 2 c u t o o > c u o co. E c o 

### u 

# 5 1 t o

o I L U q

c

. 2 

### I d o c c o U w c o u c o

< u c u S c o u O a . L U o o

< r- L L ( N r o a g * o o d 

### S o 

### §
o g L L £ C O £

• c4 2

. 2 7 t o 5 * c u ^ c o c o £ j = < y u c 0 1 ill i

CO CL

L U o o

" O o § 8 6 > U J 

### 8 U c o • E ( 0 u 

### 1 c u u t o JO o o 

### 1 P g i l

0 0 o o ^ ' ^ L O L O P 9 = ts g U

J l i U C O c r v I S t o v d

C O O < 5

. £ U Q u u u c c 0 0 > « C O — w O Q c u c u co* n c £ :

—( 0 u £ « ( D C O Q 2 - 

## | | 8 

# 1 5 c

- o o < z 0 0

o I L U 0 0

r v o I L U o ( N r o

0 0 o I L U L O r v a i

C U " S £ 0 1 ^ o j

. 2 o
_o < 2 " K

. £ Q U J , 1 S y u r

v < £ u r

v o z

—c 5 o ) E c o o Q

. - Q 

# 1 = < o C

O o I L U r o L O o o

« 5 » 0 1 o
— C O C Q

~ y U u T T C ' o z c I V

o I L U r\ i r o



# - 1 C O E 0 ) rr o . = o J E " f i c I V

o I L U t o Tl
- 

### £ 2

5 ^
c u o £ O c • 2 * t o w c c u _ t>2= = 3 O I < o j m 

# 5 °

• o c c u o . 2 , o > x "O co < £ 3 i S = " O o x < I
- r\ i

L O o i LU rs i r v

0 ) i

< C

O o o 9 9 L U t U rs i f \ t o t o r o t o cr > O ) o O L U L U o o C O
0 0 O U J U j o o r o ro # L O L A 9 9 LU U i 

### S 3 r\ i rs i t o o LU Ul L O L p r\ i r\ i r o r o 

## 9- ? L U li j 9 

# 1 8
t o o ^ ( 0 g E g L

U L U 

### S I rs i N
L U C O ^ c 

# i

L o ,tt v CO * X T

r o t — O ( N < 2 rs j 

# 1

c u c c u CO *-» 

# I o

### Attachmen t3 - MassDEP Concurrenc e Lette r3 Commonwealt h o f Massachusett s

• Executiv e Offic e o f Energ y & Environmenta l Affair s

On e Winte rStree t Boston , M A 0210 8 • 617-292-550 0 

# Departmen t o

f Environmenta l Protectio n

DEVA L L PATRIC K Governo r RICHAR D KSULLIVA N JR

. Secretar y TIMOTH Y P

. MURRA Y Lieutenan t Governo r KENNET H L

. KIMMEL L Commissione r
Ma y 2 , 201 3 Derric k S

. Golde n Remedia l Projec t Manage r U S Environmenta l Protectio n Agency Regio n 1 5 Pos t Offic e Squar e Boston , M A 02109-391 2 Dea rDerrick , EP A ha s propose d a n Explanatio n o f Significan t Difference s (ESD) fo rth e Cannon s Engineerin g Bridgewate rSuperfun d sit e t o documen t a chang e i n a componen t o f th e remed y containe d i n th e 198 8 Recor d o f Decisio n (ROD ) fo rth e managemen t o f migratio n operabl e unit

. MassDE P ha s reviewe d th e fina l draf t o f th e ES

D an d concur s wit h th e propose d revisions

. Th e purpos e o f th e ES

D i s t o revis e th e groundwate rcleanu p criteri a containe d i n th e RO D t o reflec t th e curren t criteri a containe d i n th e Massachusett s Contingenc y Pla n (MCP)

. Th e 198 8 RO D reflecte d th e groundwate rcleanu p criteri a tha t existe d prio rt o th e 199 3 revision s t o th e MC P whic h establishe d a ne w groundwate rclassificatio n intende d t o addres s remediatio n a t wast e disposa l sites

. MassDE P outline d th e criteri a tha t currentl y appl y a t th e Cannon s Bridgewate rsit e i n a recentl y complete d Groundwate rUs e an d Valu e Determination

. Than k yo u fo rth e opportunit y t o revie w th e ESD

. W e loo k forwar d t o continuin g ou rwor k wit h yo u o n th e Cannon s Bridgewate rsite

. Pleas e fee l fre e t o contac t m e i f yo u hav e an y question s regardin g thi s matter
. Very truly yours /

da y Naparste k Deput y Divisio n Directo r Burea u o f Wast e Sit e Cleanu p

Thi s informatio n i s availabl e i n alternat e format

. Cal l Michell e Waters-Ekanem , Diversit y Director , a t 617-292-5751

. TDD # 1-866-539-762 2 o r1-617-574-686 8 MassDE P Website : www.mass.gov/de p Printe d o n Recycle d Pape r