1118360-RBSDM S 

### Remedia l Actio n Repor t Recor d o f

Preparation , Revie w an d Approva l Midval e Sla g Superfun d Sit e Ground-wate r

Thi s report

ha s bee n prepare di n accordanc e wit h EP A OSWE RDirectiv e 9320.2-09 A an dwil l b e use da s abasi s for developmen t

ofth e Fina l Closeou t

Report . Remedia l Actio n Repor t

Prepare dBy :

Ton y Howe s Environmenta l Scientist/Projec t Manage r Utah Departmen t

o f Environmenta l Qualit y Remedia l Actio n Repor t

Approve dBy :

Bil l Murray , Directo r Superfiin dRemedia l Progra m Environmenta l Protectio n Agency , Regio n VII I 

# lliy 1^7REMEDIA L ACTIO N REPOR T MIDVAL E SLA G SUPERFUN D SITE , MIDVALE , UTA H EP A CERCLI S I D NUMBE RUTD08183427 7

GROUND-WATE R I . INTRODUCTIO N Th e Midval e Sla g SuperfimdSit e i s locate di n acommercia l an dresidentia l are ao f Midval e City , Utah . Th e Sharo n Stee l Superfun dSit e (UTD980951388 ) an dJorda n River li e immediatel y adjacen t t o th e Site . Redevelopmen t activitie s ar e currentl y underway a

t th e Sit e an dinclud e th e constructio n o f hig h densit y residentia l an d commercia l areas . Th e property owne r ha s complete dsevera l residentia l area s tha t ar e no w occupied . Midval e City estimate s tha t approximatel y 6,90 0 resident s wil l liv e a t th e Site afte r redevelopmen t

i s complete . A lea dan dcoppe r

smelte r an dmillin g facility operate dat th e Sit e from1871-1971 . Th e facilit y als o produce dothe r

metals , includin g gol dan dsilver . Waste s generate dfromth e smeltin g an dmillin g proces s wer e dispose do f on-site . Thes e waste s include darseni c trioxide, calcine , sla g an dothe r smelter-relate dwastes . Ground-wate r

beneat h th e Midval e Sla g Sit e i s comprise do f thre e distinc t

hydrogeologi c units : th e unconfine duppe r san dan dgrave l aquifer

(US&G ) whic h i s als o referre dt o a s th e shallo w unconfine daquifer , th e confine ddee p principa l aquife r an daloca l perche d unit . Waste s generate dan ddispose do f on-sit e contaminate dth e US& G aquife r primaril y with arsenic . A tetrachloroethen e (PCE ) plum e als o exist s at th e Sit e an d originate s fromasourc e eas t an dupgradien t

ofth e Site . Th e Sit e ha s bee n th e subjec t o f envirormiental conce msinc e 198 2 whe n th e first know n investigatio n wa s completed . Th e result s o f thi s an dothe r

investigation s foun delevate d level s o f heav y meta l contaminant s i n soils , surface-water , sediment s an dground-wate r at th e Site . I n Jun e 198 6 th e EP A propose dtha t th e Sit e b e place do n th e Nationa l Prioritie s Lis t (NPL) ; it becam e final i n Febmar y 1991 . Th e Environmenta l Protectio n Agenc y (EPA ) an dUtah Departmen t o f Environmenta l Qualit y (UDEQ ) addresse dth e Sit e a s tw o operabl e unit s (QU I an d0U2) . Operabl e Uni t 1 comprise s th e northe mportio n ofth e Sit e an dinclude s th e Wincheste r Estate s Mobil e Hom e Park . Remedia l activitie s a t OU I wer e complete di n Marc h 199 9 an d include dth e excavatio n an ddisposa l o f contaminate dsoils . Operabl e Uni t 2 comprises th e southe m18 0 acre s ofth e Site . Th e selecte dremed y for 0U 2 addresse dcontaminate d ground-water , mixe dsmelte r wastes , slag , an dsoils . Th e property owne r complete d remedia l actio n activitie s tha t addresse dmixe dsmelte r wastes , sla g an dsoil s at 0U 2 i n Ma y 2007 . Th e EP A an dUDE Q allowe dth e propert y owne r t o abando n monitorin g well s previousl y installe dat th e Sit e for

ground-wate r

investigatio n purpose s i n orde r t o facilitat e wor

k associate dwith th e remedia l actio n activitie s tha t addresse dmixe dsmelte r wastes , slag , an dsoils . Ground-wate r an dth e installatio n o f ne w well s wer e no t 1addresse da s par t o f th e remedia l activitie s complete db y th e propert y owner . Instea dth e EP A an dUDE Q deferre dactio n o n ground-wate r unti l alate r

date . Th e 0U 2 ROD , whic h i s th e subjec t ofthi s report , wa s signe dOctobe r 29 , 2002 . II . OPERABL E UNI T BACKGROUN D Th e remed y selecte dfor

ground-wate r

di dno t activel y attemp t

t o restor e th e Uppe r

San d an dGrave l (US&G ) aquifer . Instead , th e remed y establishe dmonito r in g point s for assessin g ground-wate r

condition s an drequire dth e implementatio n o f institutiona l controls . Th e majo r

component s ofth e ground-wate r remed y selecte di n th e 0U 2 RO D consiste dofth e following :

• Provid e ground-wate r an dsurfac e wate r

monitorin g t o asses s whethe r applicabl e grotmd-wate r

an dsurfac e wate r

quality criteri aar e bein g me t for th e selecte d contaminant s o f

conce m(COCs ) (antimony , arsenic , cadmium , an dseleniimi) . Point s o f assessmen t

wil l b e use dt o giv e regulatory agencie s an earl y indicatio n i f contaminatio n i s spreadin g laterall y o r verticall y v^dthi

n th e boundarie s ofth e Site . Analyse s o f

sample s collecte dfrommonitorin g location s establishe dwithi n th e inorgani c contaminan t

plum e alon g th e Jorda n Rive r wil l b e assesse dagains t altemat e concentratio n limit s (ACLs ) establishe dbasedo n th e result s o f site

specifi c analyse s an dcalculations .

• Establis h institutiona l control s (ICs) , includin g expandin g th e Sharo n Stee l Restricte dAre at o includ e th e US& G aquifer ; restrictin g surfac e wate r managemen t

an dirrigatio n practice s t o limi t infiltratio n ove r

th e US& G inorgani c contaminan t

plum e an dit s sourc e areas ; an drequirin g building s constmcte dove r th e US& G aquife r

PC E plum e t o instal l indoo r ai r vapo r systems . I n Febmar y 200 6 th e EP A issue da n ES D t o clarif

y certai n modification s ofth e OU I remed y decisio n regardin g lan dus e restrictions , th e riparian zone , an dground-water . Th e ES D identifie dth e lac k o f remedia l actio n objective s for ground-wate r

i n th e OU I RO D an dadopte dth e remedia l objective s selecte dfor groimd-wate r

i n th e 0U 2 ROD . O n Jun e 26 , 200 7 th e cit y o f Midval e adopte dinstitutiona l control s a s ordinanc e No . 6/26/200 7 0-8 . Thi s ordinanc e restrict s ground-wate r use , regulate s surfac e wate r managemen t

an dirrigatio n practices , an drequire s vapo r mitigatio n system s for

building s constmcte dove r

th e PC E plume . Thi s ordinanc e amend s an dreplace s th e previou s institutiona l contro l proces s pla n adopte da s ordinanc e b y Midval e City i n May 2004 . Ground-wate r

us e a t Midval e Sla g i s als o restricte dthroug h th e Sharo n Stee l Restricte d Are awhic h th e Utah Divisio n o f Wate r Right s (UDWR ) administer s throug h th e Sal t Lak e Valle y Ground-wate r Managemen t

Plan . III . CONSTRUCTIO N ACTIVITIE S Th e UR S Corp , at

th e directio n o f

UDE Q constmcte daground-wate r monitorin g syste m o f 2 9 tw o inc h monitorin g well s at th e sit e i n Decembe r

2008 . A n existin g monitorin g wel l installe dfor

investigatio n purpose s an dnot abandone dt o facilitat e work complete d b y th e propert y owne r

was foun dt o b e i n goo dworkin g order . Th e UDE Q incorporate d thi s wel l int o th e monitorin g syste mconstmcte di n Decembe r 2008 . Th e UR S drille dan d 2installe dmonitorin g well s i n accordanc e with th e Utah Administrativ e Cod e R655- 4 fo r Wate r Wel l Drillers . Th e monitorin g syste mconsist s o f collocate dwell s at

1 5 locations , fo

r atota l o f 3 0 well s (Attachmen t

A) . Eac h wel l pai r

consist s o f

on e shallow-depth monitorin g wel l screene d i n th e uppermos t

interva l o f

th e US& G aquife r

an don e intermediate-depth monitorin g wel l screene di n alowe r interva l vsdthi

n th e US& G aquifer . Th e monitorin g syste mi s divide dint o foti

r group s base do n monitorin g objective s an dconsist s o f AC L monitorin g wells , plum e cor e monitorin g wells , an dupgradien t an ddowngradien t

monitorin g wells . Th e specifi c objectiv e for eac h ofthes e group s i s a s follows :

• Th e AC L monitorin g well s asses s th e concentratio n an ddistributio n o f COC s prio r t o discharg e t o th e Jorda n River .

• Plum e cor e monitorin g well s asses s th e concentratio n an ddistributio n o f inorgani c COC s i n area s previousl y shov mt o exhibi t th e highes t

concentration s o f thes e contaminants .

• Upgradien t

well s monito r

upgradien t

condition s for

th e inorgani c COC s an dals o serv e t o delineat e th e exten t o f PC E i n th e US& G aquifer .

• Downgradien t

well s asses s dow n an dcros s gradien t condition s betwee n th e contaminate dground-wate r an damimicipa l wel l operate db y Murra y City . Waste s derive ddurin g th e constmctio n o f th e monitorin g syste mconsiste do f dril l cutting s an dwel l developmen t water . Effort s wer e mad e to separat e clea n dril l cutting s fro mpotentiall y contaminate dcuttings , t o th e exten t possible . Potentiall y contaminate d dril l cutting s wer e the n properl y dispose do f i n th e on-sit e repository . Developmen t wate r wa s properl y dispose do f at th e City o f

Midvale' s stormdrai n system , atemporar y on-sit e trench , an dat

th e Sout h Valle y Wate r

Reclamatio n facility . IV . CHRONOLOG Y O F EVENT S

Dat e Octobe r 29 , 200 2 Septembe r

30 , 200 4 Septembe r

200 4 Febniar y 200 6 May 28 , 200 8 Septembe r

25 , 200 8 Novembe r

200 8 Decembe r

200 8 January 22 , 200 9 January 2 6 t o February 6 , 200 9 Ma y 15,200 9 Apri l 2 4 t o Ma

y 6,200 9 Jul y 2 0 t o 31,200 9 Ongoin g Even t RO D fo r 0U 2 signe d Ground-wate r

Basi s o f Desig n Report

i s approve d Groun dan dSurfac e Wate r Monitorin g Plan i s approve d ES D regardin g ground-wate r i s issue dfor

O U 1 Cooperativ e Agreemen t

betwee n EP A an dUDE Q approve d UDE Q direct s UR S Corp . t o instal l aground-wate r monitorin g syste man dperfor

mquarterl y monitorin g for on e year Ground-wate r

Installatio n Quality Assuranc e Pla n i s finalize d Constructio n ofth e ground-wate r monitorin g syste m Samplin g an dAnalysi s (SAP ) & Quality . Assuranc e Plan s Firs t quarte r o f groun dan dsurfac e wate r monitorin g i s complete d Monito r Wei l Installatio n Report

i s finalize dan dapprove d Secon dquarte r

o f groun dan dsurfac e wate r monitorin g Thir dquarte r

o f groun dan dsurfac e wate r monitorin g Quarterl y groun dan dSurfac e wate r monitorin gV . PERFORMANC E STANDARD S AN D CONSTRUCTIO N QUALIT Y CONTRO L Monitorin g well s wer e constmcte daccordin g t o followin g specifications :

• At location s wher e th e perche daquife r was encountered . Th e UR S seale dth e aquife r fromth e underlyin g US& G aquife r b y drillin g an dinstallin g a10-inc h diameter , schedul e 8 0 PV C casin g t o adepth tha t encountere dth e confinin g layer , roughl y 4 0 fee t

belo w th e groun dsurfac e an dfilling i t with bentonit e grout . Th e bentonit e grou t

wa s allowe dt o solidif

y for severa l day s after

installin g th e surfac e casing . Drillin g the n resume dwith a n 8 '/4-inch diamete r

borin g throug h th e solidifie dgrou t

an dcontinue dt o th e specifie ddepth .

• Th e installe dwel l casing s wer e 2-inc h diameter , schedul e 4 0 PVC . Th e end s wer e threade dfor

flush joint s an dn o glue , solvents , o r lubricatin g compoimd s wer e use dt o mak e th e coimections . • Wel l screen s consiste do f 2-inc h diameter , schedul e 4 0 PV C with a0.010-inc h slo t openin g an dwer e 1 0 feet in length .

• Th e primar y filter

pac k consiste do f

10-2 0 silic asand , installe dt o at leas t 2 feet abov e th e screen . Th e UR S baile dth e well s for 3 0 minute s t o settl e th e filter pac k an dadditiona l 10-2 0 silic asan dwas added , a s necessar y t o reac h th e specifie d height .

• Th e secondary filter

pac k consiste do f

20-4 0 silic asand , installe dt o at leas t 1 foo t above th e primar y filter.

• Th e remainin g armulu s space , t o th e surface , was filledwit h either , bentonit e grout , i f abov e th e wate r

tabl e o r cours e granular

bentonite , i f

belo w th e wate r table . VI . FINA L INSPECTIO N AN D CERTIFICATIO N Th e UDE Q conducte dafinal inspectio n ofth e ground-wate r monitorin g syste mo n Augus t 3 , 2009 . Th e EP A an dMidval e City previotisl y inspecte dth e monitorin g syste m o n Jul y 1 , 2009 . Informatio n provide db y th e UR S a s par t ofth e UDE Q inspection , suc h a s groun dan dsurfac e wate r monitorin g data , indicates th e syste mi s fimctioning a s intende db y th e desig n documents . Th e UDE Q an dEP A hav e determine dtha t constmctio n o f

th e monitorin g syste mi s complete ; however , i t was note ddurin g th e UDE Q inspectio n tha t

attachmen t

o f wel l identificatio n label s neede dt o b e completed . Ther e wer e n o health an dsafet y problem s encountere ddurin g constmctio n o f th e monitorin g wel l system . Wor k activitie s proceede daccordin g t o th e Bingha mJunctio n Residential Are aBackbon e Infrastructur e Healt h an dSafet y Pla n an daUR S saf

e wor k plan develope dspecificall y for groun dan dsurfac e wate r monitoring . Th e Backbon e Infrastmctur e Health an dSafet y Plan cover s geneira

l activitie s at

th e Sit e an di s considere dth e Sit e Health an dSafet y Plan .VII . OPERATIO N AN D MAINTENANC E

Th e UR S complete dfirst an dsecon dround s o f

quarterl y groun dan dsurfac e wate r monitorin g at

th e Midval e Sla g Site i n Febmar y 200 9 an dMay 2009 , respectively . Report s documentin g th e findings ofth e firs t an dsecon droimd s o f

monitorin g hav e bee n receive db y th e UDE Q an dEPA . Groun dan dsurfac e wate r sample s collecte ddurin g thes e events wer e analyze di n accordanc e v^t h th e USEP A Contrac t Laboratory Procedur e (CLP) , b y AL S Datachem , aCL P certifie dlaboratory . Meta l concentration s i n groim dan dsurfac e wate r sample s di dno t

excee dperformanc e standard s establishe di n th e 0U 2 ROD . Groundwate r elevation s recorde ddurin g th e first an dsecon dmonitorin g event s sho w ground-wate r i n th e US& G aquifer

flows toward s th e northwes t an ddoe s no t appea r t o b e spreadin g withi n th e bomidarie s ofth e site . Th e UDE Q wil l continu e t o conduc t groimdan dsurfac e wate r monitorin g a

t Midval e Sla g i n orde r

t o determin e i f

groun dan dsurfac e wate r quailit y criteri aar e bein g me t

an d t o insur e tha t

th e plum e i s no t

spreading . However , base dupo n th e result s ofth e first tw o quarterl y monitorin g events , th e UDE Q an dEP A anticipat e changin g t o semi-annua l groun dan dsurfac e wate r monitorin g i n th e sprin g o f 2010 . VIII . SUMMAR Y O F PROJEC T COST S Estimate dcost s for

task s specifi c t o th e installatio n o f th e ground-wate r

monitorin g system , quarterl y monitoring , an doperatio n an dmaintenanc e (O&M ) ar e a s follows : TAS K 1 . Projec t Managemen t 2 . Revie w o f

Groundwate r

Desig n 3 . Installatio n o f

Grouftd-water

Monitorin g Syste m 4 . Groimdan dSurfac e Wate r Desig n Sampling/Monitorin g 5 . Databas e an dGI S Support 6 . Annua l Operatio n an dMaintenanc e TOTA L COS T ESTIMAT E $14,894.2 3 $2,546.9 9 $304,811.8 8 $174,093.9 0 $18,378.5 1 $235,950.0 0 $750,675.5 1 IX . OBSERVATION S AN D LESSON S LEARNE D • Th e UR S utilize daloca l drillin g compan y t o instal l ground-wate r monitorin g wells . Th e us e o f

alocal drillin g compan y reduce dmobilizatio n cost s an d provide dafinancial an demploymen t benefi t t o th e local economy .

• Th e abandonmen t

o f a n existin g monitorin g wel l (MW-504s ) wa s not require di n orde r t o performwor

k tha t addresse dmixe dsmelte r wastes , sla g an dsoil . Thi s monitorin g wel l wa s incorporate dint o th e overal l desig n an dreduce dcost s associate dwit h drillin g an ddevelopin g awel l a t thi s location . • Constmctio n derive dwaste s wer e dispose do f i n th e on-sit e repository . Disposa l o f theis e waste s i n th e on-sit e repository benefite dth e overal l constmctio n o f th e monitorin g syste ma s i t eliminate dconcem s relate dt o of f sit e disposal , an d reduce dth e tun e spen t

handlin g an dtransportin g th e wastes .X . CONTAC T INFORMATIO N

Th e UDE Q use dth e followin g contracto r for th e ground-wate r

RA : Tamm i Messersmith UR S Corportatio n 75 6 Eas t Wincheste r

Sfree t Suit e 40 0 Sal t Lak e City , Uta h 8410 7 801-904-400 0 www.urscop.co m Th e UDE Q Projec t

Mange r is : Ton y Howe s 16 8 Nort h 195 0 Wes t Sal t Lak e City , Utah 8411 4 801-536-428 3 thowes(a),utah . go v Th e EP A Projec t

Mange r is : Em aWaterma n U S EP A Regio n 8 159 5 Wynkoo p 8EPR-S R Denver , C O 80202-112 9 303-312-676 2 waterman . ema@epa . go vATTACHMENT- A MA P O F MONITORIN G WEL L LOCATION S^ Monitorin g Wel l Pai r ( S - Shallo w an d I - Intennediate )

• Surfac e Wate rSamplin g Locatio n

0 20 0 40 0 60 0 9 Fee t Figur e 1 . Sit e an d Locatio n Ma p Groundwate ran d Surfac e Wate rMonitorin g Project Plan s Midval e Sla g Superfund / Propose d Bingha m Junctio n Sit e @ (^ ) Januar y 200 9

UR S