## Explanatio n o f Significant Difference s Moye r Landfil l Site Montgomer

yCounty , Pennsylvani a

I . Introduction Thi s Explanatio

n o f Significan

t Difference s (ESD ) has bee n prepare d b yth e U.S . Environmenta l Protectio n Agenc yRegio n II ! (EPA) , t o describ

e a potentia l chang

e in a portio

n o f th e selecte d remedia l action , th

e metho d o f leachat e treatment , a t th

e Moye r Landfil l Sit e locate

d i n Lower Providenc e Townshi

p i n Montgomer

yCounty , Pennsylvani a ('th

e Site") . EP

Ai s th e lea d agenc yfor Sit e activitie s an

d th e Pennsylvani a Department o f Environmenta l Protectio n (PADEP ) i s th

e suppor t agenc

yfo r th e Site . Th e change describe

d in thi s ES D i s contingen

t o n th e satisfaction ! b

yMa y31 , 2000 , o f certai

n condition s describe d mor e full

ybelow , including , but no t limite

d to , th e constructio

n o f a municipa l intercepto

r b yMontgomer

yCount yan d th e Townshi p o f Lowe r Providence , an

d th e commitmen t b

yth e Commonwealth o f Pennsylvani a t o desig n an d construc t a leachat e collectio n an d transfe r syste mt o carr yleachat e t o a Publicl

y Owne d Treatmen t Work s (POTW ) vi a th

e municipa l interceptor . Th

e Recor d o f Decisio

n (ROD ) fo r th e Site was signe

d o n September 30 , 1985 . Thi s ES D i s issue d i n accordance wit

h Sectio n 1 17(c ) o f th

e Comprehensiv

e Environmenta l Response , Compensatio n an d Liabilit yAc t (CERCLA ) a s amended , commonlyknow n a s Superfund , 4 2 U.S.C . § 9617(c) , an d 4 0 CF R § 300.435(c)(2)(i) . 

### Th e leachat e treatment metho

d selecte d i n th e RO D require d th e constructio

n o f a leachat e treatmen t facilit yon-site ; thi s ES

D contingentl

yselect s treatmen

t o f th e leachat e at a POTW . Th e remedia l actio

n contingentl

yselecte d b yth e ESD for th

e leachat e treatment wa s originall y described , in severa l variations , in bot h Remedia l Actio

n Alternative s # 2 an

d # 4 in th e ROD . EPA' s contingen

t decisio n t o change thi s portio

n o f th e remedia l actio

n i s base d upo n a reques t mad e b yPADE P durin

g a n Apri l 26 , 199 9 meetin

g wit h th e EPA , an d i n a follow-u

p lette r date d Jun e 24 , 1999 . PADE P ha s explaine d it s preference fo

r treatmen t o f th e leachat e at a POT

W base d upo n th e following :

• Recent flo

w dat a indicate s tha t th

e leachat e treatment plant , a s currentl ydesigned , i s no t suitabl

ysize d t o handl e existin

g an d projecte d leachat e flow

s fro mth e landfil l an d coul d thus resul t i

n significan t operatio n an d maintenanc e difficulties .

• Treatmen

t an d disposal o f leachat e fro

mth e landfil l int o th

e POT W wil l bette

r 

### protec t th e water s o f th

e Commonwealt

h an d th e environmen

t fro mpotentia l failure s o f a n undersize d treatmen t plant .

• Acontrac t ha s bee

n awarde d t o construc t a sewe

r mai n o n Arcol a Roa

d whic h i s i n close proximit

yt o th e Site .

• Th e right-of-wa

ybetwee n th e landfil l an

d th e sewe r mai n ha s bee

n surveye d an d 

# AR00002 6acces s t o th e propert yca n b e secure d b yth e Commonwealt

h pursuan t t o State authority .

• Routin

g th e leachat e discharge

d fro mth e Moye r Landfil l t o a publi c sewe r lin e i s no w mor e cos t effectiv

e tha n buildin g an d operatin g a leachat e treatmen

t facilit y an d equall yeffectiv e in th e treatment o f th

e leachate . Thi s contingen

t actio n i s protectiv

e o f huma n healt h an d th e environment , an

d complie s wit

h Federa l an d State applicabl e o

r relevan t an d appropriat e requirement s (ARARs ) fo r thi s actio n in complianc e wit

h Sectio n 12 1 o f CERCLA , 4 2 U.S.C . § 9621 . PADE P requeste

d th e contingen t chang e an d ha s concurre

d wit h th e ESD , a s note

d i n a lette r date d Decembe r 23,1999 . Thi s document present s a synopsi s o f informatio n regardin g th e Site , a summar

yo f th e contingen t chang e t o th e remed yselectio n i n th e RO D for leachat e treatment , an d a summar yo f 

### th e conditions t o b

e satisfie d i n order for th

e change describe

d i n thi s ESD t o becom

e effective . Th e ESD wil l becom

e par t o f th e Administrativ

e Recor d fil e pursuan

t t o 4 0 CF R § 300.825(a)(2) , whic

h include s th

e complet e documentatio

n relatin g t o th e Moye r Landfil l Site . Acop yo f th e Administrativ

e fil e i s locate

d at : U.S . Environmenta l Protectio n Agenc yj 165 0 Arch Stree t Philadelphia , Pennsylvani a 1910 3 215-814-315 7 An d Lower Providenc e Townshi

p Buildin g 10 0 Parklan

e Driv e Eagleville , P

A1940 3

II . Site History , Contaminatio n Problems , an

d Selecte d Remed y Th e Moye r Landfil l Sit e i s a 6 5 acr e inactiv e privatel yowne d landfil l locate

d a t Moye r Road , Collegeville , Lower Providenc e Townshi p in Montgomer

yCounty , Pennsylvania . Th

e landfil l i s bounde d o n th e nort h an d wes t b yEvansbur g Stat e Park , t o th

e eas t b ylan d owne d b yHowar d an d Catherin e Moye r an d Providenc e Builders , Inc. , an d o n th e sout h b ylan d als o owne

d b y Providenc e Builder s Inc . an

d Charle s Leonard . Th

e landfil l wa s formall

yclose d in Apri l 1981 , 

### afte r operatin g nearl y4 0 years .



# AR00002 7Th

e Sh e ha d been operate

d a s a municipa l landfil l fro

mth e earl y1940 s unti l Apri l 1981 , durin g whic h tim e i t receive

d municipa l waste , sewage , an d industria l sludges . Th

e landfil l accepte

d a variet yo f soli d an d liquid hazardou

s wastes , includin

g polychlorinate

d biphenyl s (PCBs) , dioxins , solvents , paints , low-leve l radioactiv e wastes , an

d incinerate

d material s in bul k for

m and/o r containerize

d drums . Th

e origina l unline

d landfil l area wa s approximatel y3 9 acre s in size . I n th e lat e 1970s , th

e landfil l owner s submitte

d a reques t t o expan

d th e landfil l boundarie s t o th e northwest . Sit e preparatio

n wor k bega n o n a ne w area i n 1977 , an

d include d installatio

n o f a n asphal t line

r prio r t o filling . Landfillin

g wa s reportedl

ylimite d t o thi s new , line

d area fro m th e lat e 1970 s t o earl

y1981 , a t whic

h tim e af i order fro

mth e Pennsylvani a Department o f Environmenta l Resource s (no w PADEP ) close

d th e facility . 

### Ther e were numerous seeps at th

e Site . Eighty-six organi c priorit ypollutant s an

d sixtee n priorit y pollutan t metal s wer e observe

d i n th e sample s take

n fro mth e Sit e prio r t o remediation . O

n an d off-site groundwater , th

e leachate , soil , an

d surface wate r (Skippac

k Creek ) wer e contaminate

d wit h heav ymetal s an d volatil e organi c compound s (VOCs ) fro mwast e disposa l activities . PCB s hav e been foun

d i n th e trou t i n Skippac

k Creek . Leachat e an

d affecte d sediment s contain substantial level s o f contaminant s and , therefore , ma ypos e risk

s t o individual s wh

o accidentall

y ingest , inhale , or com

e int o direc t contac t wit

h them . Drinkin

g contaminate

d groundwater or consumin g contaminate

d trou t fro mSkippac k Cree k als o ma ypos e significan

t threats . Groundwater wa s no t th

e direc t vehicl e o f contaminan t transport fro

mth e Site becaus e th

e groundwater leve l i s lower tha n th e botto mo f th e landfill . Th

e transport o f contaminatio

n wa s mostl ydu e t o surface water percolatio

n throug h unline d portion s o f th e landfill , som

e o f whic h migrate d int o th e groundwater . Th

e contaminant s a t th

e Sit e were transporte

d directl yt o th e surface water (Skippac

k Creek , whic

h i s a tributar

yt o th e Perkiome n Creek ) vi a surface water runof f an d indirectl ythroug h contaminate

d groundwater fro

mth e uppe r aquife

r discharge d t o th e creeks . Th e lowe r aquife r wa s no t contaminated . O n Septembe r 30,1985 , th

e Regiona l Administrator signe d th e RO D for th e Sit e whic h require d th e followin g remedia l actions :



### • Soi l cove r wit

h a permeabilit

yrange o f 10" 4 t o 10' 5 cm/sec • Erosio

n an d sedimentatio

n contro l measure s • Surface water diversio n • Leachat e collection , treatmen t an d discharg e , • Methan

e ga s recover

yan d sal e ; . • Security/fencin

g measure s • Groundwater monitorin g .- . t . ; • Al l closur

e activitie s i n complianc e wit h RCR Aa t conclusio

n o f ga s generatio

n phas e (1 0 t o 2 0 years ) r , i 

### Th e implementatio

n o f thi s remed

yalternativ e depende d o n th e succes s o f th

e ga s 

### generation/recover

yprogra man d th e contribution

s fro mgenerator s an

d other potentiall

y


# AR00002 8responsibl e parties . I f th e methane recover

yalternativ e failed , th e RO D identifie

d a contingen

t alternative , whic

h wa s ultimatel

yused , a s follows :

• Miscellaneous wor

k preparator

yt o installatio

n o f RCR Acap : grading , flattenin

g o f stee p slopes , constructio

n o f retainin

g wall s an d installatio

n o f rip-ra p a t areas tha t ar e mos t likel

yt o b e erode d • Ga s ventin

g an d ga s monitorin

g • Surface water collectio n an d discharg e t o Skippac

k Cree k • Leachat e collectio

n an d treatmen t tha t wil l mee t th

e discharg e requirement s i n th

e strea man d limi t th e ris k o f advers e healt

h effect s fro

mgroundwater consumptio

n t o on e i n on e millio n • Operatio

n an d Maintenance : groun

d an d surface water monitoring , maintenanc e o f th e ca p an d treatmen t o f leachat e Th e installatio

n an d shak e dow n perio d o f th e RCR Acap , whic

h wa s th e contingen t remed yi n th e ROD , wa s complete

d in Ma y1996 . Th

e leachat e treatmen

t portio n o f th e remed ywa s no t constructe d a t tha t time . III . Descriptio

n o f Significan

t Differences an

d th e Basi s fo r thos e Differences ; Circumstance s unde r whic h Contingen t Remed ywil l b e Implemente d EP Ai s issuin

g thi s ES D t o describ

e a contingen

t chang e i n th

e selecte d remedia l actio

n fro mj leachat e collectio

n wit h treatmen t on-sit e t o leachat e collectio n wit h treatment a t a

n existin g POTW . Th e contingen

t remedia l actio

n wa s originall

ydescribe d i n Alternative s # 2 an

d # 4 i n th e ROD . Th e actua l treatmen

t o f th e leachat e wil l b

e simila r t o th e origina l remed

yselecte d excep t tha t i t wil l b

e conducte d off-site . Th

e actio n i s protectiv

e o f human healt

h an d th e environment , an d complie s wit

h Federa l an

d Stat e applicabl e or relevant an d appropriat e requirements . Th e overal l strateg

ya t th e Moye r Landfil l Sit e i s t o mitigat e an d minimiz e har

mt o publi c healt

h an d th e environment . Thi s shoul

d includ e minimizin

g furthe r uppe r aquife

r contaminatio

n an d th e possibilit yo f direc t contac t wit

h th e waste . Th e majo r objective s fo

r remedia l actio

n are t o mitigat e o r eliminat e environmenta l contaminatio n throug h collectin g an d treatin g leachat e fro

m th e landfil l an d cappin g th e Site , whic h ha s bee n completed , t o contro l leachat e generatio n an d soi l erosion . Leachat e contro l i s a n integra l par t o f th

e overal l schem

e in order t o eliminat e th

e continuin g migratio n o f contaminant s acros s th

e Sit e an d of f th e Sit e t o th e Skippac k Creek . A t th e tim e th e RO D wa s signe

d i n 1985 , th

e optio n t o discharge th

e leachat e t o a POT

W wa s no t practica l or cos t effectiv

e becaus e th

e infrastructur

e wa s no t available . Sinc e tha t time , a contrac t ha s bee

n awarde d for th e constructio

n o f th e sewe r mai n o n Arcol a Road , whic

h i s i n clos e proximit

yt o th e Site . PADE P ha s obtaine

d informatio

n fro mLower Providenc e Township , th e Montgomer

yCount ySewe r Authority , an

d th e Oaks Treatmen

t Plan t confirmin g tha t th e infrastructur

e an d capacit ywil l b e availabl e t o mak e a sewe

r hook-u p fo r treatmen

t o f th e



# AR00002 9leachat e unti l i t i s n o longe r necessary . PADE P conducte

d a presen t wort h analysi s for th

e leachat e treatmen

t facilit yon-sit e an d for treatment a t th

e POTW . Thei r 30-yea

r presen t wort h analysi s resulte

d i n a presen

t wort h for th e leachat e treatment plant o f $3,344,25 0 an d a presen t wort h o f th e leachat e treatmen

t a t th e POT W o f $1,151,351 . Th

e leachat e treatmen

t a t th e POT W woul d b e mor e cos t effective . Th e chang e t o th

e leachat e treatmen

t metho d i n th e selecte d remed ydescribe d i n thi s ESD i s contingen t o n th e fulfillmen t o f al l o f th

e followin g requirement s to'EPA' s satisfactio n b yMa y 31,2000 . Thes e requirement s wer e previousl yse t fort h i n a lette r fro mEP At o PADE P date

d Septembe r 9,1999 . With respec t t o thes e requirements , th e Commonwealth ha s addresse d it s commitment s i n a lette

r date d Septembe r 17,1999 . I n addition , EP Awil l desig

n an d construc t a n equalizatio

n tan k at th e landfil l fo r leachat e storage .

• Th e Commonwealth o f Pennsylvani a ("th e Commonwealth" ) shal l commi t i n writin g t o mak e al l modifications t o th e existin g remedy , t o properl

ydesig n an d construc t th

e leachat e collectio

n an d transfe r syste mtha t wil l carr

yleachat e t o th

e municipa l "interceptor " pipe , an d t o ensure tha t th

e leachat e collectio

n an d transfe r syste moperate s properly . Th

e municipa l intercepto

r wil l carr yth e leachat e t o th

e Oak s Sewage Treatmen

t Plant .

• Th e Commonwealth shal l obtain al l necessar yacces s an d permit s t o construc t th

e leachat e collectio

n an d transfe r system .

• Th e municipa l intercepto

r shal l b e buil t an d functionin

g properly .

• Th e Commonwealt

h shal l enter int o al l long-ter mcontract s needed for treatmen t o f landfil l leachat e at th

e Oaks Sewage Treatmen

t Plant . I t i s EPA' s understandin

g tha t tw o separat e contract s wil l b

e needed : on

e wit h th e Montgomer

yCount ySewe r Authorit y(MCSA ) an

d a secon d wit h Lowe r Providenc e Township . EP

Afurthe r understands tha t MCS Awil l requir e a one time , lum p su mpaymen t i n connectio

n wit h th e contrac t an

d tha t Lower Providenc e wil l require annua l payment s i n additio n t o a one-tim

e lum p su m payment . Th

e Commonwealth shal l mak e thes e payments .



### • Receip t b

yEP Ao f a lette r fro ma perso n wit h proper authorit

yove r th e Oaks Sewage Treatmen

t Plan t whic h state s that , base

d o n curren t an d pas t data , th

e Oak s Sewage Treatmen

t Plan t wil l not , a t present , require pre-treatmen t o f th e leachat e (i.e. , treatmen

t o f leachat e before i t enter s th e Oak s Sewage Treatment Plant) . EP Aha s receive

d a cop yo f suc h a letter , writte

n b yth e engineer fo r th

e Oaks Sewag

e Treatmen t Plant , date

d Augus t 3,1999 . 

# AROOOQ3 0Th e Commonwealth shal l commi t i n writin g t o assum e al l responsibility , financial an d otherwise , for an

ytreatment o f Moye r Landfil l leachat e tha t ma yb e require d in th e future . Thi s includes : (1 ) performin g an ypre-treatmen

t o f leachat e tha t ma

y b e require d i n th e futur e t o sen d leachat e t o th

e Oak s Sewage Treatmen

t Plant ; an d (2 ) constructing , operatin

g an d maintainin

g a n on-sit e leachat e treatment plant i f an yo f th e condition s abov e are no t fulfille

d b yMa y31,2000 , or th

e leachat e collectio n an d transfe r syste mi s no t constructe

d b yJul y31,2000 , an

d operatin g properly , followin

g a on e yea r shak e dow n period , b yJuly31,2001 . IV . Suppor t Agenc

yComment s PADE P wa s provide

d wit h a cop yo f th e propose d ESD , an d provide d concurrenc e i n a lette

r date d Decembe r 23,1999 . EP

Aissue d th e ESD i n respons e t o PADEP' s reques t mad e durin g a n Apri l 26,199 9 meetin

g wit h th e EPA , an d i n a follow-u

p lette r date d Jun e 24,1999 . V . Affirmatio

n o f Statutor

yDetermination s EP Abelieve s tha t th

e ES D remed

yi s protectiv

e o f human health an

d th e environment , an

d complie s wit

h Federa l an

d State applicabl e o

r relevan t an d appropriat e requirement s in accordanc e wit

h Sectio n 12 1 o f CERCLA , 4 2 U.S.C . § 9621 . Th e publi c participatio

n requirement s se t out a t 4 0 CF R § 300.435(c)(2)(i ) have been met . A cop yo f thi s ESD ha s been place

d i n th e Administrativ

e Recor d whic h i s availabl e fo r publi c revie w a t th e location s liste d abov e i n Sectio n I o f thi s ESD , an

d a notic e summarizin

g th e ES D wa s publishe

d i n Th e Philadelphi a Inquirer . VI . Signatur e U.S . ENVIRONMENTA

L PROTECTIO

NAGENC

Y

I Dat e Abraha mFerdas , Directo

r Hazardou s Site Cleanu

p Divisio n



# AR00003 I