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### EPA/ROD/R08-99/05 5 199 9



# EP A Superfun d Recor d ofDecision :

CALIFORNI A GULC H EPAID : COD98071793 8 OU0 9 LEADVILLE , C O 09/02/199 9

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OPERABL E UNI T 9 CALIFORNI A GULC H SUPERFUN D SIT E LEADVILLE , COLORAD O

Septembe r 199 9

U.S . ENVIRONMENTA L PROTECTIO N AGENC Y

99 9 18 TM STREE T SUIT E 50 0 DENVER , COLORAD O 8020 2

### RECOR D OF DECISIO N RESIDENTIA L POPULATE D AREA S OPERABL E UNI T 9 CALIFORNI

A GULC H SUPERFUND SIT E LEADVILLE , COLORAD O Th e U.S . Environmental Protectio n Agency (EPA) , with th e concurrenc e ofth e Colorad o Departmen to f

Publi c Healt

h an d Environmen t(CDPHE) , presents thi s Record ofDecisio n (ROD ) fo r th e Residential Populate d Area s Operabl e Uni t9 (OU9 ) ofth e Californi a Gulc h Superfund Site in Leadville , Colorado . Residential/populate d are a soil s includ e thos e i n residential yards , vacan tlots , parks , schoo l yards , playgrounds , and communit y us e areas , includin g unpave d streets and alleys . Th e RO D i s based on th e Administrativ e Recor d fo r OU9 , includin g th e Residential Soil s Feasibilit y Study , th e Propose d Plan , th e publi c comments received , includin g thos e fro m th e potentiall y responsibl e partie s (PRPs) , and EP A responses . Th e RO D presents a brief summar y o f sit e characteristics , actua l an d potential risk s t

o huma n healt h an d th e environment , and th e Selecte d Remedy . EP A followe d th e Comprehensiv e Environmental Response , Compensation , an d Liabilit y Act , a s amended , th e National Contingency Pla n (NCP) , and appropriat e guidanc e i n preparatio n o f th e ROD . Th e thre e purpose s of th e RO D ar e to : 1 . Certif

y tha tth e remedy selectio n proces s wa s carrie d ou ti n accordanc e wit

h th e requirements o f

th e Comprehensiv e Environmental Response , Compensation , an

d Liabilit y Act , 4 2 U.S.C . 960 1 etseq. , a s amende d b y th e Superfun d Amendments and Reauthorizatio n Ac t(collectively , CERCLA) , and , t o th e exten tpracticable , th e National Contingency Pla n (NCP) ; 2 . Outlin e th e engineerin g components an d remediatio n requirement s ofth e Selecte d Remedy ; and 3 . Provid e th e publi c wit h a consolidate d sourc e o f informatio n abou tth e history , characteristics , and ris k pose d b y th e condition s o f

OU9 , a s wel l a s a summar y o f th e remedia

l alternative s considered , thei r evaluation , th e rational e behin d th e Selecte d Remedy , and th e agencies ' consideratio n of , an d response s to , th e comments received . Th e ROD i s organize d into thre e distinc tsections : 1 . Th e Declaratio n sectio n function s a s a n abstrac tfo r th e ke

y informatio n containe d i

n th e RO D an

d i s th e sectio n o f

th e RO D signe d b

y th e EP A Regional Administrato r an d th e CDPHE Director . 2 . Th e Decisio n Summar y sectio n provide s a

n overvie w ofth e OU9 characteristics , th e alternative s evaluated , an d th e analysi s o f thos e alternatives . Th e Decisio n Summar y als o identifie s th e Selecte d Remed y and explain s ho

w th e remed

y fulfill s statutory and regulator y requirements ; an

dTh e Responsivenes s Summar y sectio n addresse s publi c comment s received on th e Propose d Plan , th e Residentia l Soil s Feasibilit y Study , and othe r informatio n i

n th e Administrativ e Record .DECLARATIO N

SIT E NAME AND LOCATIO N Residential Populate d Area s Operabl e Uni t9 Californi a Gulc

h Superfund Sit

e Leadville , Colorad o 

### STATEMEN T O F BASI S AN D PURPOS E Thi s decisio n documen tpresent s th e Selecte d Remedy fo r OU9 withi n th e Californi a Gulc h Superfun d Site i

n Leadville , Colorado . EPA , wit h th e concurrenc e o f

CDPHE , selecte d th e remedy in accordanc e wit h CERCLA and th e NCP . Thi s decisio n i s based on th e Administrativ e Record fo r OU9 withi n th e Californi a Gulc h Superfun d Site . Th e Administrativ e Record (o n microfilm ) an d copie s o f

ke y document

s ar e availabl e fo r revie w atth e Lake Count y Publi c Library , locate d at111 5 Harriso n Avenu e in Leadville , Colorado , and a tth e Colorad o Mountai n Colleg e Library , i n Leadville , Colorado . Th e complete Administrativ e Record ma y als o b e reviewe d a tth e EP A Superfun d Record Center , locate d a t99 9 18 * Street , 5 * Floor , Nort h Terrac e i

n Denver , Colorado . Th e State o f

Colorad o concur s wit

h th e Selecte d Remedy , a s indicate d b y thei r concurrenc e lette r date d Septembe r 2,1999 . ASSESSMEN T O F TH

E SIT E Soil s a tth e Site have elevate d level s o f heav y metal s a s a resul to f

minin g an

d smeltin g operation s i

n th e Leadvill e area . Although metal s othe r tha n lead ar e no tpresen tat concentration s tha tpresen trisk , level s o f lead , if no taddresse d b

y implementin g th e respons e actio n selecte d i n thi s ROD , ma

y presen ta

n imminentan

d substantial endangermen tt o publi c health , welfare , o r th e environment . DESCRIPTIO N O F TH E SELECTE D REMED Y Th e Californi a Gulc

h Superfund Sit

e i s divide d into twelv e medi a an d geographically-base d operabl e unit s (OUs ) withi n th e Site . Operabl e Uni t9 , designate d a s th e residential populate d areas , addresse s concentration s oflea d i n soil , dust , paint , an

d wate r tha texcee d a specifi c se to f trigge r criteria . Th e purpos e ofthi s respons e actio n i s t o reduc e th e ris k o f

lea d exposur e t

o childre n in Leadvill e and surroundin g areas . Remedia l action s take n withi n OU9 ar e intende d t o b e consisten twit

h th e remedia

l actio n objective s an d goal s identifie d fo r th e entir e Californi a Gulc h Superfund Site an

d othe r OU investigations .Th e selecte d remed y fo r addressin g residential populate d area s i s th e Lake Count y Communit

y Healt h Progra m (LCCHP) , presente d i n th e Final Feasibilit

y Study (ASARCO , 1998 ) a s Alternativ e 7 . Thi s i s simila r t o th e Lea d Ris k Reductio n Progra m an d th e Kid s Firs tProgram , describe d in th e Consen tDecree' . Th e Kid s Firs tProgra m i s currentl y bein g implemented . Th e Selecte d Remedy combine s blood lead monitoring , education , communit

y awareness , and residence-specifi c respons e action s t o reduc e th e ris k of lea d exposur e t o childre n i

n Leadvill e and surroundin g residentia l areas . Thi s progra

m wil l addres s lead fro

m soi l and dust , interio r o r exterio r paint , leaded plumbin g fixtures , an d othe r potentia l source s beyond a n individual residence . Th e majo r component s ofth e selecte d remed y include :

• A n extensiv e educatio n an d interventio n progra

m t o manag e lea

d exposur e a tth e site . Th e educatio n progra m wil l focu s o n raisin g publi c awarenes s abou trisks fro

m lead an

d encourag e participatio n i n th e Lake Count

y Communit

y Healt h Program .

• Continue d voluntary bloo d lea d monitorin g (wit

h financia l incentives , a s appropriate ) fo r al l childre n ag e 6-72 month s an d voluntar

y bloo d lea

d monitorin g fo r pregnan tand nursin g women .

• Ifth e concentratio n o f lea d i n bloo d o f

a chil d o r a pregnan to r nursin g woman exceed s th e bloo d lea d criterion , o r i

f th e concentratio n o f

lea d exceed s a specifie d se tof

trigge r criteri a fo r on e o r more o f th e environmenta

l medi a ata residence , then appropriat e action s wil l b e taken t o addres s th e exceedance . Thes e trigge r criteri a ar e summarize d below :

Bloo d Lead greate r tha n o r equa l t o 1 0 • g/dL Soi l greate r tha n o r equal t o 3,50 0 pp

m Dus tgreate r tha n o r equa l t o 2,00 0 pp

m Pain tInterio r o r exterio r paint , i n poo r condition , wit

h th e followin g lead levels : greate r tha

n o r equal t o 1 mg/cm ^ Educatio n greate r tha

n o r equal t o 6 mg/cm ^ Activ e Remediatio n Tap Wate r greate r tha n o r equa l t o 1 5 * g/ L

•O n Augus t25,1994 , a Consen tDecre e betwee n th e Unite d States , Stat e o f Colorado , ASARCO , Inc . (ASARCO ) and Resurrectio n Minin g Compan y wa s entere d in U.S . Distric tCour ti n Denver . Tli e Consen tDecre e define s area s o f responsibilit

y fo r thes e tw o companie s a s wel l a s th e U.S .• Whe n on e o r mor e o f th e trigge r

criteri aar e exceeded , arang e of differen t respons e actions , a s provide d in th e Decisio n Summary , wil l b e evaluated . Th e mos t appropriat e respons e action s wil l b e determine d b y evaluatin g th e natur e an d exten t

ofth e exceedance , overal l protectivenes s ofth e action , complianc e with applicabl e o r relevan t an d appropriat e requirements , long-ter meffectivenes s an d permanence , short-ter meffectiveness , implementability , cost-effectiveness , an d communit y impacts . View s ofth e propert y owne r

wil l als o b e considered . N o respons e actio n wil l b e conducte d withou t th e permissio n ofth e propert y owner .

• Th e selecte d remed y als o include s institutiona l controls , discusse d in detai l in th e Decisio n Summary , t o ensur e effectivenes s of th e LCCH P an d t o provid e anotificatio n syste mfo r

propert y owners .

• Sinc e th e LCCH P i s considere d a"pilo t project " tha t

involve s anumbe r

o f innovativ e approaches , i t include s ongoin g revie w t o ensure , tha t th e progra mi s operatin g a s intende d an d tha t huma n healt h i s bein g adequatel y protected . I n addition , th e progra mwil l b e evaluate d b y agrou p o f outsid e scientists . And , a s with an y remed y wher e wast e i s lef t in place , EP A wil l conduc t five-yea r review s t o ensur e tha t

th e remed y i s protectiv e o f huma n healt h an d th e environment . An y problem s with th e progra mwil l b e identifie d an d adjuste d a s necessary . STATUTOR Y DETERMINATION S Th e Selecte d Remed y i s protectiv e o f huma n healt h an d th e environment . I t complie s with federa l an d stat e requirement s tha t ar e legall y applicabl e o r relevan t an d appropriat e t o th e remedia l actio n an d i s cos t effective . Althoug h thi s alternativ e doe s not satisf y th e statutor y preferenc e fo r

aremed y tha t

employ s treatmen t

t o reduc e th e toxicity , mobility , o r volum e o f

contaminant s a s aprincipa l element , thi s remed y utilize s permanen t solution s an d alternativ e treatmen t (o r resourc e recovery ) technologie s t o th e maximu mexten t practicable . Becaus e thi s decisio n wil l resul t in hazardou s substance s remainin g o n site , abov e health-base d levels , five-yea r review s ofthi s respons e actio n wil l b e required . Thes e review s wil l b e conducte d durin g site-wid e five-yea r reviews . Th e nex t

five-yea r revie w i s schedule d t o b e performe d not late r tha n Februar y 2001 .

Ma x H . Dodson , Assistan

t Regiona l Administrato r

Dat

e 7 Environmenta

] Protectio n Agency , Regio

n V mDat a Certificatio n Checklis t Th e followin g informatio n i s include d in th e Decisio n Summar y sectio n ofthi s Record of Decision . Additional informatio n can b e foun d i n th e Administrativ e Record file fo r thi s site .

• Chemical s o f concer n (COCs ) and thei r respectiv e concentration s • Baselin e ris k represente d b y th e COC s • Cleanu p level s establishe d fo r COC s an d th e basi s fo r thei r level s • Curren tand futur e lan d and groundwate r us e assumption s used i n th e baselin e ris k assessmen tan d RO D • Land and ground-wate r us e thatwil l b e availabl e a tth e sit e a s a resul tof th e Selecte d Remedy • Estimate d capital , operatio n & maintenanc e (O4&M) , and total presen twort

h costs ; discoun trate ; and th e numbe r o f year s ove r which th e remed y cos t estimate s ar e projecte d • Decisiv e factor(s ) tha tle d t o selectin g th e remed

y

### DECISIO N SUMMAR YTABL E O F CONTENT S

Sectio n Titl e Pag e L SIT

E NAME , LOCATION , AN D DESCRIPTIO N 9 n . OPERABL E UNI T AN

D ENFORCEMENT ACTIVITIE S 9 III . HIGHLIGHT S O F COMMUNIT Y PARTICIPATIO N 1 4 IV . SCOP E AN D ROL E O F OPERABL E UNI T 1 6 V . SUMMAR Y O F SIT E CHARACTERISTIC S 1 7 VI . SUMMAR

Y O F SIT E RISK S 2 0 vn . REMEDIA L ACTIO N OBJECTIVE S 2 2 VIII . DESCRIPTIO N O F ALTERNATIVE S 2 3 DC . SUMMAR Y O F COMPARATIV E ANALYSI S

O F ALTERNATIVE S 2 6 X . SELECTE D REMED Y 2 9 XI . STATUTOR Y DETERMINATION S 3 5 xn . DOCUMENTATIO N O F SIGNIFICANT CHANGE S 3 6 XIII . REFERENCE S 3 7 APPENDI X A - SIT

E LOCATIO N MAP , FIGUR E 1 APPENDI X B - RESPONSIVENES S SUMMAR Y APPENDI X C - APPLICABL

E O R RELEVANT AN

D APPROPRIAT

E REQUIREMENT S (ARARS )DECISIO N SUMMAR Y FO RTH E RECOR D O F DECISIO N RESIDENTIA L POPULATE D AREA S CALIFORNI A GULC H SUPERFUN D SIT E LEADVILLE , COLORAD O L SIT E NAME , LOCATION , AN D DESCRIPTIO N The Califomi aGulc h Superfiin d Sit e (EP A I D #COD980717938 ) consist s ofa n approximately 18.5-square-mil e are atha

t i s par t ofth e histori c Leadvill e Mining Distric t i n Lak e County , Colorado . Thi s site i s locate d in th e Colorad o Minera l Belt , ahighly mineralize d are aofth e Colorad o Rock

y Mountains . Or

e mining , minera

l processing , an d smeltin g activitie s hav e produce d lead , zmc , gold , an d silve r fi-omthi s world-clas s minera l deposi t fo r mor e tha n 13 0 years . The elevatio n ofth e Californi aGulc h Sit e range s from9,44 8 fee

t a t the confluenc e o f

Lak e For k Creek and the Arkansa s Rive

r a t th e southweste mboundar

y ofth e sit

e t o over 12,00 0 fee

t abov e mea n se alevel nea

r Ball Mountai n eas t

o f Leadville , Colorado . Tw o parallel , north-sout h oriente d mountai n ranges , the Sawatc h Rang e o n th e wes t and th e Mosquito Rang e o n the east , for ma long , narro w valley i

n which th e Residentia

l Populate d Are ai s located . Leadvill e i s locate d o n the easte msid e ofth e valley create d b y thes e tw o mountain ranges . Th e easte mportio n ofth e sit e i s compose d ofth e steep foothill s ofth e Mosquito Range . Th e Califomi aGulc h flow s alon g the southe mboundar

y o f Leadville , passin g to th e nort h o f Stringtown , an d the n flows west-southwes t

befor e enterin g th e Arkansa s Rive r nea r the Lak e For k Trailer Park . Thi s Record ofDecisio n (ROD ) applie s to area s ofth e Sit e tha t hav e bee n designate d a s Operabl e Unit 9 (OU9 ) Residentia

l Populate d Areas . Thes e area s includ e portion s ofth e sit

e wher e th e land us e i s residential o r

tha t ar e currentl y zone d a s residential-populate d area s and a s low-densit y residential area s (Appendi x A) . Th e selecte d remed y i s necessar

y to prevent

th e actua l o r the potential releas e oflea d contaminatio n which coul d impac t publi c health . I L OPERABL E UNI T HISTOR Y AN D ENFORCEMEN T ACTIVITIE S The Cahfomi aGulc h Superfiin d Sit e i s locate d i

n an d around th e communit

y o f Leadville , Colorado , about

10 0 mile s southwes t

o f Denver . Th

e Leadvill e are awa s th e sit e o f extensiv e mining , milling , and smehin g operation s beginnin g abou t 1860 . Mos t

ofth e facilitie s cease d operation s aroun d 1900 , althoug h severa l facilitie s continue d operation s int o th e 1920 s (Weste m Zinc ) an d th e 1960 s (A

V Smelter ) (Walsh , 1993) . Nearl y all ofth e mine s withi n th e Sit e boundarie s ar

e presentl y inactive , and al l ofth e mill s an d smelter s hav e bee n demolished .EP

A place d the Sit

e o n th e National Prioritie s Lis t (NPL ) i n 198 3 primarily due to conce move r the impac t o f min e drainag e o n surfac e water s in th e Califomi aGulch an d th e Arkansa s River . Subsequent

sit e investigation s reveale d th e presenc e o f heav y metal s i

n soil s an d i n waste pile s i

n and aroun d the current

residential and commercia l area s o f Leadville . Numerou s investigation s hav e bee n conducte d a t th e Site . Thes e includ

e remedia l investigation s conducte d b y EPA , th e State o f Colorado , Resurrectio n an d ASARC O beginnin g a s early a s 1986 . Remedia

l investigation s include d determinatio n o f natur e and exten

t o f contaminatio n in the following media : surfac e water , groundwater , air , tailing s (bot h fluvial an

d impounded) , wast

e rock , slag , and soils . Other remedia l investigation s which hav e been conducte d include : metal s speciation , aquati c ecosystem , terrestrial ecosystem , and th e evaluatio n o f source s oflea d i

n an d aroun d residential homes . Curren t activitie s a

t th e Sit e includ e completio n o f

feasibilit y studie s evaluatin g remedia

l altematives , remedia

l design , and constmction . A summar y o f enforcemen

t activitie s a

t th e site includes : O n Decembe

r 9 , 1983 , th e State o f

Colorad o filed a

n actio n fo r injury , destmction , or los s o f natura l resource s associate d wit

h th e releas e ofhazardou s substance s and the cos t

o f assessmen t

ofsuc h injur

y fromthe Ya

k Tunnel and associate d min e workings . The State amende d it s complain t o n April 8 , 1985 , t

o includ e additiona

l claim s fo r reimbursement

o f cost s incurre d and to b e incurre d i n respons e t o th e releas e o r threa t o f releas e ofhazardou s substance s a t the Ya k Tunnel , associate min e workings , Califomi aGulch , and portion s ofth e Arkansa s River . O n Augus t

6 , 1986 , th e Unite d State s o f Americ afiled a

n actio n seekin g mjunctive relie f fo r performanc e o f

responsibilitie s consisten

t wit h the Nationa

l Contingenc y Pla n (NCP ) and fo

r reimbursement

o f cost s incurre d an

d t o b e incurre d b y th e U.S . i n respons e to th e releas e o r threa t o f releas e ofhazardou s substance s a t the Site .

• O n Febmar

y 3 , 1987 , th e federa

l and stat e action s wer

e consolidate d int

o on e proceedmg .

• Counter-claim s were asserte d fo r contributio n agains t

bot h the Unite d State s and th e Stat e i n thi s consolidate d action .

• O n Marc h 9 , 1988 , EP A issue d aRO D selectin g the remedia l actio n fo r the Ya k Tuime l Operabl e Unit . Thi s RO D ha s subsequently bee n amended . The defendant s ar e conductin g this'wor

k under aUnilatera

l Administrativ e Orde

r (UAO ) issue d b y EPA .

1 0In respons e t o arelease , or asubstantia

l threa t o f arelease , ofhazardou s substance(s ) a

t o r fromthe Site , EP

A commence d (o r

administrativel y ordere d variou s partie s t o commence ) variou s remedia l investigation s and feasibilit y studie s or othe r wor k consistent

wit h th e NCP : O n September

28 , 1990 , EP

A an d the Settlin g Defendant s entere d int o a n Administrativ e Order

o n Consent

(AOC ) fo r the performanc e o f

soil s sampling an d ai r monitoring . O n December

14 , 1990 , EP

A an d th e Settlin g Defendant s entere d int o a n AO C fo r performanc e o f

sit e improvemen

t activitie s a

t th e Garibald

i Workings , th e Nort

h Mik e Workings , th e Orego n Gulc h Tailing s Pond , and the Star r Ditch . O n Augus t

29 , 1991 , EP

A issue d aUnilatera

l Administrativ e Order

(UAO ) tha

t require d ASARC O t

o conduc t studie s and complet

e RI s relate d t o th e following : Demographic s Wor

k Plan ; Fina

l SampUn g Pla n fo r Samplin g and Analysi s o f Lea d Occurrenc e Withi n and Immediately Adjacen t to Residences ; Soi l Investigatio n Wor k Plan ; Min e Waste Pil e Remedia l Investigation ; Tailin g Disposa l Are a Remedia l Investigatio n Wor

k Pla n an d Surfac e Water , Be d Material an d Aquati c Ecosyste mDat aCollectio n Progra mWor k Plan . A Firs t

Amendmen

t to thi s UAO , issue d o n October

8 , 1991 , require d ASARC O to conduc t and complet

e th e Hydrogeologi c Wor

k Plan . A Secon d Amendmen t t o th e UAO , issue d Novembe r 21 , 1991 , require d ASARC O to conduc t and complet

e the Smelte

r Sit e Investigatio n Wor

k Plan . A Thir

d Amendmen

t t o thi s UAO , issue d Septembe r 8 , 1992 , require d ASARC O t o conduc t and conplet e th e Wor

k Pla n fo r Terrestrial Ecosystem s Evaluation . A Fourt h Amendmen

t to thi s UAO , issue d o n Marc h 9 , 1993 , require d ASARC O to conduc t an d complet e the pre-minin g Soi l Geochemistr

y Remedia

l Investigatio n (RI) . The remainin g wor k performe d b y ASARC O imde

r UA O 91-19 , a s amende d wa s the final R I repor t fo r eac h ofth e abov e activities . T o date , ASARC O ha s submitte d fma l R I report s fo

r Mine Waste , Tailin g Disposal , Surfac e Water , Terrestrial Ecosyste mEvaluation , Smelte r Sit e Remedia

l Investigation , Hydrogeologi c Remedia l Investigatio n Report , Soi l Inventor y an d Geology , wit

h DataAmendments , Demographic s Dat aReport , and DataRepor t fo r Lea d Occurrenc e In/Adjacen

t t o Residences . O n September

10 , 1991 , EP

A issue d aUA O tha

t require d Resurrectio n Minin g Company t o conduc t

an d complet e th e final Soil s Investigatio n Wor k Plan . Fiel d wor k under thi s UA O wa s complete d i n summe r 1992 . Resurrectio n submitte d a fma l R I repor t t o EP A pursuant

to thi s UA O o n Jul

y 15 , 1994 . 1 1O n Septembe r 12 , 1991 , EP

A and th e Hecl aMining Compan y ("Hecla" ) entere d into a n AO C fo r preparatio n ofa n Engineerin g Evaluation/Cos t Analysi s ("EE/CA" ) fo

r the Stringtown/Malt aGulc h Tailing s portio n ofth e Califomi a Gulc h Superfun

d Site . Pursuan

t t o thi s AOC , Hecl awa s als o require d to detemiin e th e natur e and extent

ofan y release s ofth e MaltaGulch Tailing s an d an y appropriate respons e activitie s t o addres s suc h releases . On Januar y 6 , 1993 , a Partia l Consent Decre e betwee n th e Unite d State s an d Hecl awa s entere d b y thi s Court . A fma

l EE/C A wa s issue d o n Augus t 2 , 1993 , fo

r publi c revie w an

d comment . O n December

3 , 1992 , EP

A an d Th e Denver

& Ri o Grand e Weste mRaihoa d Compan y ("D&RG" ) entere d int

o a n AO C fo r the performanc e o f

aremedia l investigation/feasibilit

y stud y o n lea d sla g pile s an

d performanc e o f

specifie d studie s o n on e zinc pil e a

t th e Califomi aGulc h Superfiin d Site . D&R

G submitte d th e "Fina l R I Repor t fo r Lea d Slag Pil e Remedia

l Investigation " t

o EP A o n December 4 , 1993 , and submitte d a"Fina l Zin c Sla g Pil e Remedia

l Investigation " to EP A o n Decembe

r 11 , 1993 . O n Septembe

r 24 , 1992 , EP

A entere d int

o a n AO C wit

h ASARC O an

d Resurrectio n fo

r performanc e o f

ametal s speciatio n program . Th e Metal s Speciatio n DataRepor

t wa s issue d i

n September , 199

4 and update d i

n Ma y 1996 . A consent decre e betwee n th e Unite d State s an d D&R G wa s lodged wit

h the Cour t o n Septembe

r 15 , 1993 , and entere d o n Decembe r 15 , 1993 . Pursuaa

t to th e term s ofthi s decree , D&RG pai d aportio n ofth e Unite d States ' respons e cost s and agree d to conduc t

the remedia

l action s a t the slag pile s an

d raiboa d yar

d and easement know n a s 0U 3 (D&R G Slag Piles/Raihoa d Easement/Railroa d Yard) . A propose d consent

decre e betwee n th e Unite d State s and Hecl aaddressin g th e Malt aGulc h taihng s and Hecla' s claim s agains t th e Unite d State s wa s lodge d wit h flie Cour t i n Apri l 1994 . A partia l Consen t Decre e amon g the Unite d States , the State , an d the Settlin g Defendant s settlin g th e U.S . and th e State' s clai mfo r thei r pas t respons e cost s incurre d prio r

to Februar

y 1 , 1991 , an d Febmar

y 1 , 1992 , respectively , wa s entere d b y th e Cour

t o n Septembe

r 4 , 1993 . O n Augus t

25 , 1994 , aConsen

t Decre e wit

h ASARC O an

d Resurrectio n wa s entere d i n U.S . Distric t

Count y i n Denver . Th e Consen

t Decre e defined area s o f responsibilit

y fo r thes e tw o companie s a s wel l a s th e U.S . Govemment .

1 2A summar y o f interimaction s a

t th e sit e includes : A n Engineerin g Evaluation/Cos t Analysi s wor

k pla n wa s prepare d i

n Novembe

r 1994 (ASARCO , 1994 ) t o evaluat

e lea d concentration s i

n soil s within park s an

d playgroun d area s i

n 0U9 . Base d o n the finding tha

t soil s a t all identifie d pla

y area s wer

e belo w th e trigge

r level o f 350 0 pp mlead , EP A approve d n o fiirther

actio n fo r th e area s addresse d b y the wor k plan . Subsequently , on e additiona l pla y are awa s identifie d o n Eas t 6* " Street a t St . Patric k

Street . Soil s a

t thi s pla y are a exceede d 3500pp mlea

d in soi l s o thi s are arequire s remediation . Contaminate d soil s will b e excavated , dispose d ui asuitabl e repository , and replace d wit h clea n fill. A n Engineerin g Evaluation/Cos t Analysi s wa s prepare d m199 5 (ASARCO , 1995 ) t o evaluat e remova l actio n altemative s fo

r 3 8 mine wast e pile s identified i n the populate d area s o f

easte m Leadville , withi n OU9 , i

n accordanc e wit

h th e ASARC O Wor

k Managemen

t Pla n (WAMP ) (Appendi x B t o th e Consent Decree) . A

n Actio n Memorandumissue d b y the EP A i n Augus t 199 6 selecte d anon-time-critica

l remova l actio n requirin g th e remova l o f 1 4 pile s wit

h surfac e lea

d concentration s greater

tha n 3,500ppm . Remova

l o f thes e pile s prevent s direc t exposur e t o high lea d concentration s and protect s surfac e wate r b y removin g the potentia

l fo r transpor t o f metal s awa y fromthe sourc e are aand , therefore , reduc e metal s impac t to surfac e water

or othe r areas . Implementatio n ofthi s remova l actio n bega

n i n 1997 wit

h the remova

l o f fou r mine wast

e piles . The remova

l ofth e remainin g ten min

e wast e pile s i s schedule d fo r 1999 . The selecte d remova l actio n i s consisten t

wit h th e performanc e ofth e final remedia l actio n selecte d fo

r 0U 9 and wil l b e considere d a s th e fma

l remed y fo r mine wast e pile s within 0U 9 when conplete . Th e Kid s Firs t

Progra mi s a n interi mrespons e progra

mdesigne d to addres s source s o f environmenta

l lead a t individua l residential propertie s withu i 0U 9 (Woodward Clyd

e Consultants , 1994) . The progra

mha s bee n implemente d b y ASARCO , wit h assistanc e fromLak

e County , sinc e 1995 . Thi s voluntar

y progra mtarget s household s wit

h children unde

r 6 year s ol d an d include s bloo d lea d monitoring , testin g o f

potential environmenta

l source s oflead , and , whe n necessary , the development

and implementatio n o f

risk-based respons e action s to reduc e significan t lea d risks i n an d aroun d th e home . Lak

e Count y perform s the bloo d lea

d monitorin g and som

e educatio n component s ofth e program . Sinc e 1995 , soi l remediatio n ha s bee n performe d a t 3 7 propertie s maccordanc e wit h Actio n Memorandum s prepare d fo r eac h property . I

n addition , dus t abatement ha s bee n performe d a

t 1 6 properties , paint

remediatio n performe d a

t 6 propertie s and drinkin g water

addresse d a

t 2 properties . All action s an d no-actio n determination s hav e bee n develope d an d approve d b y th e Kid s Firs t wor k grou p and accepte d b y the propert y owner . All interimrespons e action s fo r paint , drinkin g water , an d soi l perfomie d under th e Kid s Firs t Progra mare considere d consisten t wit h th e final remedia

l actio n selecte d fo

r OU9 .

1 3II L HIGHLIGHT S O F COMMUNIT Y PARTICIPATIO N

Throughou t

EPA' s wor

k a t the Califomi aGulc h Superfiind Site , contac t wit h member s ofth e communit y ha s bee n maintaine d through publi c and neighborhoo d meetings , open houses , briefing s fo

r loca l officials , pres s releases , fac t sheets , an d othe

r informa l communication . EP

A and th e other

partie s involve d i

n th e Superfiind projec t

hav e als o establishe d loca l office s i n Leadvill e s o th e communit y ca n spea k directl y wit

h th e projec t

representatives . Commimit y group s ar

e a n importan

t component

ofth e communit

y relation s effor

t a t the Cahfomi aGulc h Superfim

d Site . The Lak

e Count y Environmenta

l Tas k Forc e (LCETF) i s a

n ope n membership grou

p o f individual s intereste d i

n environmenta

l issue s i n the Lak e Count y area . The LCET

F obtaine d a$50,00 0 technica l assistanc e grant

fromEP A tha t enable s the grou

p t o hir e consultant s and technica

l experts . Thes e expert s commen t o n technica l document s an

d evaluate th e scientifi c dat ao n the Sit e fo r th e community . EPA' s communit

y relation s activitie s a

t th e Sit e include d aserie s o f

risk assessment

workshop s conducte d fo

r communit

y leader s and healt

h professionals . I

n addition , alea

d awarenes s progra

m wa s begu n i

n Febmar y 199 0 t o teac h parent s an d childre n about th e hazard s oflead . Severa l group s hav e forme

d a s aresu h ofth e Superfim d activitie s i

n Leadville . Thes e group s provid e opportunitie s fo

r th e citizen s t

o take a n activ e rol e i

n the consultatio n an

d decision

makin g proces s fo

r the Site . A brie f

descriptio n o f

eac h o f thes e group s i s provide d below .

• Technica l Assistanc e Committee . Th e Technica l Assistanc e Committe e (TAC ) wa s forme d m199 1 and provide s aforu mfo r communit y representatives , companie s workin g a

t th e site , EPA , th e Stat

e o f Colorado , and their

technica l expert s t o discus s and evaluate th e technica l issue s relate d to th e Site . TA C meeting s ar

e open t o the pubh c and are hel d i n Leadvill e an d Denver . An y TA C membe r ma y call ameetin g an d prepar e a n agend afo

r discussion . Minute s from th e TA C meeting s are made apar t ofth e Administrativ e Recor d fo r the Site .

• Sit e Activitie s Coordinatin g Committee.Th e Consen t Decre e betwee n th e responsibl e partie s a

t th e Sit e recognize d tha

t differen t group s woul d b e workin g o n variou s remediatio n project s a t th e sam e time . The partie s doin g remediatio n wan t to ensur e tha t their wor k doe s no t mterfer e wit h the numerou s civi c an

d touris mevent s i

n town . I n orde r t o coordmate thes e wor

k efforts wit

h civi c events , aSit e Activitie s Coordmatin g Committe e (SACC ) wa s formed . Th e member s o f th e committe e mee

t wit h representative s fromthe Cit y and Coimt

y monthl y (or as-needed ) to coordinate all on-gom g an d pendin g Sit

e activitie s an d t

o mmimize dismptio n to the community .

1 4• Kid s Firs t Wor k Group . The Kid s Firs t

Wor k Group , forme

d i n 1994 , provide s directio n fo

r the Kid s Firs t

Program . Publi c healt

h official s an

d representative s o f th e Cit y o f Leadville , Lak

e County , State o f

Colorado , ASARCO , an d EP A eac h hav e membershi

p i n th e Kid s Fhs t

Wor k Group . Th

e Wor k Grou p oversee s th e development

o f informationa

l material s and plans , an

d monitor s an d evaluate s th e progres s o f

activitie s bein g implemente d unde r the Kid s Firs t

Program . Extensiv e outreac h effort s b y bot h th e Lak e Count y Healt h Departmen

t and ASARC O hav e playe d akey rol e i

n th e implementatio n ofth e Kid s Firs t Program . Th

e progra mbega n wit h a publi c meetin g o

n Ma y 25 , 1995 . Newspape r

advertisin g introduce d the progra man d continue s wit h weekl y lead educatio n "tips " fo r resident s and encouragemen t fo r bloo d lea d testin g o f children unde

r 7 2 month s and pregnant/nursmg women . Information to promot e saf e remodelin g tip s i s displaye d a

t loca l hardwar e stores . Doo r

t o doo r contact s wer

e mad e t o recmi t

familie s i n area s wit h soi l lea d concentration s estimate d a t or abov e 3,50 0 pp mi

n 1995 , 199 6 and 1997 . Presentation s hav e bee n made to communit y group s t o explai n the Kid s Firs t Program . Educationa

l session s hav e als o bee n conducte d a t publi c daycar

e centers , privat

e license d da

y car e center s and at

th e elementar

y school . Periodi c update s continu e a t thes e facihtie s an d educationa l brochure s are availabl e bot h fo r th e child-car

e provider s and th e familie s they serve . Th e progra m ha s als o worke d wit

h other preschoo l group s to combin e efforts . Th e Healt h Departmen

t work s wit h th e immunizatio n progra

man d th e Hea

d Star t an d Women , Infant s an

d Children (WIC ) organization s t o recmi t

childre n fo

r bloo d lea d testing . Reminde

r card s ar e mailed to familie s to encourag e annua

l bloo d lea

d screening . Th e LCCH P wil l continu e simila

r outreac h effort s an d ma

y pursu e altemate outreac h approache s a s ne w idea s develo p o r

a s neede d to maintai n awarenes s an d participation . All ofth e informatio n upo n whic h selectio n ofthi s remed y i s base d i s include d mth e Adniinistrativ e Record . Th e Administrativ e Record i s availabl e fo r review a t bot h th e Lak e Count y Publi c Librar

y and the Colorad o Mountai n Colleg e Librar y i n Leadvill e an d a

t th e EP A Superfiin d Record s Center

i n Denver . The publi c reviewe d th e Propose d Pla n associate d wit

h thi s ROD . Publi c comment s and EPA' s response s ar

e include d a s Attachmen

t A .

1 5

### IV . SCOP E AN D ROL E O F OPERABL E UNI T

Th e Califomi aGulc h Superfim d Sit e i s divide d mt

o twelv e medi aan d geographically-base d operabl e unit s (OUs ) withi n the Site . Thes e OU' s ar e designate d as : OUI - Ya

k Tunnel/Water

Treatmen t Plan t 0U 2 - Mah aGulc h Fluvia l Tailing/Leadvi l l e Corporatio n Mill/MaltaGulch Tailui g 0U 3 - Denve

r & Ri o Grand e Raikoa d Slag Piles/Railroad Easement/Railroad Yar d 0U 4 - Upper

CaUfomi aGulch 0U 5 - ASARC O Smelters/Slag/Mil l Site s OU 6 - Star

r Ditch/Penros e Dump/Stra

y Hors e Gulch/Evan s Gulc h 0U 7 - Apach e Tailin g Impoundment s OU S - Lowe

r Califomi aGulch OU 9 - Residentia

l Populate d Area s OUI O -Orego n Gulc h OU I 1 - Arkansa s Rive

r Valley Floodplai n OUI 2 - Sit

e Wate r Qualit y Thi s Selecte d Remed

y fo r 0U 9 addresse s concentration s oflea d i n soil , dust , pain

t and wate r tha t excee d aspecifie d set

o f trigger criteria . Exceedanc e o f

thes e criteri acoul d pos e athrea t t o huma n health , specifically i

n childre n ag e 0-7 2 months . The purpos e ofthi s respons e i s t o reduc e the risk oflea d exposure t o childre n i n Leadvill e an

d surroundin g areas . Remedia l action s undertake n withi n 0U 9 ar

e intende d to b e consistent wit h the remedia

l actio n objective s and goal s identifie d fo

r th e entir e Californi aGulch Superfim d Sit e and other

O U investigations . Thi s decisio n documen

t make s n o detemiinatio n o n whether surfac e water

or groundwate

r withi n 0U 9 require s remediation . Pursuant to th e Augus t

25 , 1994 Consent

Decre e a t thi s Site , i

t wa s agree d tha t th e decisio n o n remediatio n o f surfac e wate r

an d groundwate

r site-wide (Operabl e Uni t 12 ) woul d b e mad

e only afte r record s o f

decisio n fo

r sourc e remediatio n wer

e selecte d and implemente d a

t eac h operabl e unit . A s aresuh , specifi c water qualit y goal s fo r surfac e stream s and groundwater

hav e no t bee n establishe d a

t thi s time .

1 6V . SUMMAR Y O F SIT E CHARACTERISTIC S

1 . Climat

e and Meteorolog y The LeadviU

e are aha s a

n alpin e climat

e tha t i s ofth e semi-arid , continenta l type . Th e averag e armua l precipitatio n i s 17.5 3 inche s wit h the wettes t

month s bein g July and Augus t and dries t month s bein g Decembe

r an d January . The norma

l temperature exfreme s rang e from86 * F to -30 » F wit h a n averag e aimua

l air temperature o f

36.2 * F . The lowes t

temperature s occu

r i n January , an

d the highes t

temperature s ar

e mJuly and August . Base d o n R I data , th e maximu

m hourly averag e win d spee d range s from aminimu mo f 9 mile s pe r

hour (mph ) i n October to a maximu mo f 20. 4 mp h occurrin g mDecember ; however , wind gust s i n exces s o f

5 0 mp h d o occur . Wind i s predominantly fromth e northwest . 2 . Surfac e Wate r Hydrolog y Th e Cahfomi aGulch drain s approximatel y 7,40 0 acre s o f watershe d int

o the Arkansa s River . Th

e ma mstrea mofth e Gulch receive s water fromsevera

l ephemera

l drainage s tha

t mclud e Stra y Hors e Gulch , Star

r Ditch , Uppe

r CaUfomi aGulch , Orego n Gulch , Georgi aGulch , an d Pawne e Gulc h (CH2

M Hill , 1987) . Discharge s ar e als o receive d fromthe Ya k Tunnel through the Ya

k Wate r Treatmen t Plant , an d fromth e Leadvill e Sewag e Treatment Plant . 3 . Geology Th e geolog y ofth e Leadvill e Mmm g Distric t and surroundin g are ai s complex an d we U documented . The elevation s i n the stud y are arang e from9,35 0 fee t a t th e lowe r Arkansa s Rive

r floodplain to ove

r 14,00 0 fee

t a t th e easte medg e ofth e Leadvill e Mming Distric t drainag e (cres t ofth e Mosquito Range) . I

n general , th e topography i s mgge d o n the weste mslop e ofth e Mosquito Range . Timberlin e i s approximatel y 11,85 0 feet . Th e regio n bear s the geomorphologica

l feature s resuhin g fromPleistocen e glacia l activity . Bedroc k in th e Leadvill e are aconsist s o f Precambria

n granite an d metamorphi c rock s overlai n b y quartzite , limestone , dolostone , siUstone , sandstone , an d shal e o f Paleozoic , Mesozoic , an

d Cenozoi c age . Intmsiv e rock s include porphyr y dike s an d sill s o f

Tertiar y age . The uppe

r Cambria n Sawatc h quartzite unconformabl e overlie s th e Precambria n rocks . Thi s quartzit

e i s approximately 6 0 fee

t thick . It i s overlai n b y 4 5 fee

t o f shaley bed s o f

late Cambria

n Peerles s formation . Ordovicia

n ag e Manito u Dolomit

e uncomformabl

y overlay s th e Peerles s formation . Abov e thi s i s the Devonia

n Chaffe e formation . Thes e rock s are expose d i n th e uppe r reache s o f the Mosquito Rang e a s wel l a s i n th e hill s eas t

o f Leadville . The Leadvill e limestone (dolomite ) o f Mississippia

n ag e i s expose d i

n Leadvill e and alon g som e section s o f

lowe r CaUfomi aGulch .

1 7A syste mo f major an d mino r fault s caus e significan

t displacement

(10 0 to 1,00

0 feet ) an d fracturing o f

bedroc k i n th e area . Fault s i

n th e bedroc k

are generally high-angl e northerly-strikin g fracture zones . Block s o f

bedroc k betwee n majo

r fault s ar e commonl

y broke n b y numerou s mino r fault s an d fissures (Emmon s et al , 1927) . Th e Pender

y Fauh mark s the boundar

y betwee n uppe

r and lowe r Califomi aGulch . Th

e Pender y Fault , which trend s north-sout h acros s Califomi aGulch , ha s cause d th e lower

gulc h to b e filled wit

h thicker deposit s o f

alluvium . Thes e alluvia

l deposit s ar e mtersperse d wit

h thin , interglacial , silt

y cla y lak e be d deposits . The Leadvill e are ai s underlai n b y alluvia l deposit s and unconsohdate d glacia l outwas h material s o f Pleistocen e age . Thes e material s include porphyry , rhyolite , granite , an d othe r igneou s rocks , quartzite , dolomite , limestone , an d sandstone . Thes e material s wer e transporte d and redeposite d b y glacia l an d fluvial processes . The vertica l and latera

l exten t o f thes e alluvia

l deposit s i s no t

wel l defmed . The Arkansa s Rive r Valle y i s compose d o f

Holocen e sfrea

mterrace , strea

mchannel , and flood plai n deposits . 4 . Hydrogeolog y Groundwater

i n th e Leadvill e Minin g Distric t occur s i n bot h bedroc k and aUuvia

l aquifers . The bedroc k aquife r consist s o f

Precambria

n granite overlai n b y quartzite , porphyr y dikes , sandstone , dolostone , an d Umeston

e o f Paleozoi c age . Groundwater movemen t i s faciUtate

d b y permeabl e highly-fi^cture d zone s adjacent t o majo r interconnection s mino

r faults , intergranula

r roc k porosity , and min

e workings . PermeabiUt

y i s generally low . Groundwater

i n th e alluvia

l aquife r i s containe d i

n Tertiar y an d Quatemar

y lak e bed , glacia

l outwas h deposits , an d sfrea mand terrac e deposits . Th e alluvia l aquife r occur s i n tw o stratigraphi c units , a n uppe r uni t and alowe

r unit . The alluvia

l deposit s ar

e considere d to b e hydraulically connecte d wit

h th e bedroc k

aquife r through contact , faulting , fracturing, an d extensiv e mining activities . Recharg e to th e bedroc k and alluvia

l aquifer s result s frominfilfratio n o f precipitatio n and surfac e water . 5 . Lan d Us e an d Demograph y The Califomi aGulc h Superfiin d Site , mcludm

g the tow n o f

LeadviUe , i s locate d mLak e County , Colorado . Lak

e Count y i s arelativel y small (38 0 squar e miles) , predominantly rura l count y wit h a 199 0 populatio n o f

6,00 7 (U.S . Burea

u ofth e Census , 1990) . Person s residin g withi n the LeadviU e cit y Umit s account fo r approxunatel y hal f

o f the county' s total population . The populatio n o f

Lak e Count y ha s fluctuated wit

h th e minin

g industry . Populatio n peake d a t 18,05 4 m1890 , decline d t o belo w 7,00 0 i n 1920 , an d remaine d generally a

t tha t level unti l 1960 .

1 8Durin g the year s betwee n 196 0 an d 1981 , populatio n graduaU y mcrease d to approximately 9 , 00 0 and the n decline d throughout the 1980s . The closure o f AMAX' s Clima

x molybdenu

mmin e i n 198 1 and it s reduce d level o f operation s upo n reopenin g wer e majo r factor s contributin g to the decline . Leadville' s populatio n trend s hav e bee n simila r to thos e o f

Lak e Coimty . Approximately two-thfrd s ofth e land mLak e Count y i s federall

y owned . Mos t

ofth e federa

l land i s withi n the Sa

n Isabe l Nationa

l Forest , wit

h th e Burea

u o f Land Managemen

t managin g mos t

o f th e remainder . However , mos t land i n th e LeadviU

e Minin g Distric t

i s privatel y owned . Land use s surroundin g CaUfomiaGulc h ar e predominantl y mining , commercial , an d residential . A small are ao f

rangelan d i

n the LeadviU

e are ai s directl y upstrea

mfromth e confluenc e o f

Califomi a Gulc h and the Arkansa s River . Huma n receptors , potentiall y expose d to Sit e contaminants , include the residentia l population . Recreational/commercia

l exposure s i

n OU 9 hav e bee n detennine d to b e msignifican t (WESTON . 1996c) . 6 . Results ofth e Remedia l Investigation s Soil s are the primar

y pathwa y o f exposure to th e residentia

l populatio n a

t the site . Lea

d ha s bee n determine d t o b e th e only contaminant o f conce mi n 0U9 . Thi s discussio n will focu s o n soil s i n the 0

- to 6-inch dept

h interva l o n whic h th e risk

assessmen t

i s based . The extreme heterogeneit

y o f surfac e soil s (0

- t

o 1 -mch ) i

n Leadvill e an d Stringtow n i s als o characteristi c o f

soi l lea d concentration s i

n th e 0

- t o 6-inch near-surfac e composit e soil s foun

d i n the Leadvill e an d Stringtow n communitie s and i n th e Lak e For k Traile r Par k (Figur e 2) . Thi s variabilit y i n lead concentration s ca

n b e attribute d to th e fac

t tha t thes e soil s hav e bee n impacte d to varyin g degree s b y historica l smelte r emission s and mimn

g wastes . I n a U soils , th e lea

d concentration s typicall y decreas e wit h soi l dept h (Walsh , 1992a) . However , lea d concentration s u

i deep disturbe d soil s tha

t ar e highe r tha n the concentration s u

i the overlyin g disturbe d surfac e soi l hav e been reporte d msom e location s (CDM , 1994 ; Walsh , 1993) . Thi s i s mos t likely du e t o th e intermixin g o f soil s wit h mine waste s o f

highly variabl e lea

d content . The lea d concentration s i

n surfac e soil s an d th e concentration s oflea d a t specifi c soi l dept

h interval s ar e discusse d in th e Soil s Investigatio n an d mappin g Repor t (Walsh , 1992a) . Ther

e i s alea d concentratio n gradient

observe d i

n near-surfac e soi l withi n LeadviU e tha t ha s a n east-wes t orientation , wit

h the maximu

mlea d concentration s appearin g i n the east , du e to historica

l mining activities , and droppin g i

n the westward direction .

1 9Th e ol d Downtow n Leadvill e Nfmin g Distric t (Emmons , 1907 ) locate d i n the easte mpar

t of LeadviUe , wa s foun

d to contai n th e highes t

lea d concentrations . The soil-lead concentration s i n thi s are aand mth e southeaster n par t o f Leadvill e ar

e likely to excee d 3,50 0 ppm . Soil-lea d concenfration s ar

e als o lUcel

y highe r i n Stringtown , wher

e lea d concentration s i

n the 0

- to 6-inc

h dept h interva l typicall y rang e from2,00 0 pp mto greater tha n 3,50 0 ppm . I

n addition , som

e area s a t th e nort h an d sout h end s ofth e Lak

e For k Trailer Par k ar e likel y to contai n soi l wit

h elevate d lea d concentrations . VI . SUMMAR Y O F SIT E RISK S Durin g th e soil s remedia

l investigation , abaselin e huma n healt h ris k assessment

wa s performed t

o estimate th e probabilit

y and magnitude o f

potentia l advers e huma

n heaU h an d envfronmenta

l effect s fromexposure t o hazardou s substance s associate d wit h th e Site . The huma

n heah h risk assessment

foUowe d afour-ste

p process : 1 . Contaminan t

Identification , whic h identifie d thos e hazardou s substance s of potential healt

h concem ; 2 . Exposur e Assessment , which identifie d actua l or potentia l exposur e pathway s (route s where peopl e contac t th e chemicals) , characterize d the potentiall y expose d populations , an d determine d th e extent o f possibl e exposure ; 3 . Toxicity Assessment , whic h considere d the type s and magnitude o f advers e healt

h effect s associate d wit

h varyin g amount s ofth e hazardou s substance s o f concem ; and , 4 . Risk

Characterization , which integrate d the thre e previou s step s t o summariz e the actua l current an d fiature potentia

l risks pose d b y exposur

e to hazardou s substance s a

t th e Site . Par t A ofth e huma

n healt h risk assessmen t

(WESTON , 1996a

) examine d risk s t

o resident s from lead , focusing specifically o n risks t o youn g childre n (ag e 0 to 6 years) . Children wer e selecte d a s th e focu s ofthi s risk

assessmen t

becaus e childre n typically hav e highe r intak e rate s pe r uni t bod y weigh t o f envfronmenta

l medi atha

n aduhs , childre n ten d to absor b ahighe r fraction o f

ingeste d lea d fromth e gasfrointestma

l trac t tha n d o aduhs , and children ten d to b e mor e susceptibl e t

o som e ofth e advers e effect s oflea d tha n aduh s (especiaU

y impairmen

t ofth e nervou s system) . Par t B ofth e huma

n healt h ris k assessmen t

(WESTON , 1996b ) conclude d tha t ther e are n o location s o

n sit e where antimony , barium , cadmium , beryllium , chromium , copper , mercury , nickel , silver , thallium , or

zin c ar e o f significan t conce mi n soil . The risk

assessment

als o

2 0conclude d tha t base d a n th e fac t tha t risk exceedance s ar

e sma U fo r arseni c and manganes e and occur onl y i n the mos t conservativ e risk

calculations , combme d wit h th e recognitio n tha

t the assume d uptak

e (bioavaUabUity) o f

metal s use d i

n th e calculation s ma

y b e highe r tha n actual , tha

t non-lead metal s (includin g arseni c an d manganese ) i n surfac e soil s d o no t

pos e asignifican

t healt h risk to residents . Thus , th e only contaminan t o f conce mi s lead . Ris k Assessmen tApproach fo r Lea d The risk assessment

fo r lead wa s supporte d b y alarg e bod y o f site-specifi c dat atha

t include d no t onl y extensiv e measurement s oflea d i n soi l an d dus t i n residentia

l locations , bu t

als o a n extensiv e demographic s survey , dat ao n lea d level s mwater

and paint (bot h interio r and exterior) , dat ao n th e physica

l an d chemica

l forms o f lea d a t variou s location s aroun d th e community , and a n informativ e community-wide bloo d lea d stud y involvin g 31 4 childre n ( abou t 65 % ofth e tota

l populatio n o f

children a t the site) . Thes e dat awer

e use d t o suppor

t tw o paraUe

l lme s o f investigatio n an d assessment . Th e first o f thes e employe d EPA' s Integrate d Exposur e Uptak e and Biokineti c (lEUBK) mode l t o calculate the expecte d impac t o f lea d level s msoi l an

d dus t o n bloo d lea d level s i n are achildren . The secon d approac h compare d th e measure d bloo d lea d value s i n are achildre n wit

h relevant nationa l bloo d lea

d statistic s i

n order t o hel p evaluat e the curren

t effect s o f actua l sit e exposure t o lead . The main finding s ofth e lea d ris k assessment

fo r residentia l childre n ar e summarize d below : 1 . I n 1991 , geometri c mea

n bloo d lea

d level s i n childre n livm

g withi n the sit

e boundarie s wer e typically aroun d 5-6 * g/dL , which wa s abou t 1-1. 5 • g/d

L highe r tha n reporte d geometri c mea

n value s fo

r childre n o f

simila r ag e and sex livm

g mother area s acros s th e nation . 2 . I n 1991 , th e site-wid e frequency o f children exceedin g the CDC' s health-base d bloo d lea d targe t o f 1 0 • g/d L wa s about

8% , which i s slightly highe r tha n th e target

o f n o mor e tha n 5 % abov e 1 0 • g/dL . Thi s wa s indicativ e o f asituatio n which exceede d EPA' s goa l o f n o uidividua l chil d o r grou p o f similarl y expose d childre n havin g agreater tha n 5 % chanc e o f exceedmg abloo d lea

d level o f 1 0 • g/dL . I

n som e sub-area s ofth e site , the risk o f exceedin g 1 0 • g/d

L appeare d t o b e substantiall y highe r (10%-25% ) tha

n the site-wid e average . Additiona

l bloo d lea

d dat acollecte d b y coimt

y healt h agenc y frommor

e tha n 10 0 childre n pe r

yea r fo r eac h yea r betwee n 199 1 an d the presen t suggest s tha

t the incidenc e o f children i n th e commimit

y wit h bloo d lea

d level s abov e 1 0 • g/d

L i s continuin g t

o fluctuate betwee n 6 % an d 9% . 3 . There i s astatisticall y significan t correlatio n betwee n lea

d level s rangin g from3,000pp m to 3,50 0 pp mmsoi l an d dus t and elevate d bloo d lea

d level s i n children .

2 14 . Bot h interio r an d exterio r

leade d paint

contribute to risk

o f elevate d bloo d lea

d level s i n children , mainl

y b y addmg to th e concenfratio n oflea d i n soi l and/or

dus t mthos e home s where lead-base d paint

i s apotential sourc e oflea d exposure . 5 . Th e resuh s ofth e lEUB K model ru n usin g defauh soi l and dus t ingestio n rate s predicte d bloo d lea d level s tha

t were highe

r tha n observed . It

wa s conclude d tha

t soi l and dus t ingestio n rate s i

n thi s communit

y wer e probabl y somewha

t lowe r tha n the nationa

l averag e values , possibl y becaus e th e ground i s frozen o r snow-covere d approximately eigh t month s ou t

ofth e year . Loca

l efforts to minimiz e lea

d exposur e through a

n extensiv e educatio n and interventio n progra mmigh t als o explai n som

e ofth e variatio n i

n predicte d versu s currentl y observe d bloo d lea d levels . 6 . Base d o

n th e analyse s conducted , th e risk assessment

reache d the conclusio n tha t soi l lea d i s arelativel y minor

sourc e o f exposur e a t location s wher

e lea d level s wer

e les s tha n abou t 1,00 0 ppm . Exposur

e vi aso U probabl y di d no t

become adominan

t sourc e o f exposur e unti l lea d level s were abov e th e range from3,000pp mt o 3,50 0 ppm . Othe

r source s oflea d contributin g to current

exposure include d interio r and exterior

pain t an d indoo r dust . Lea d level s i n th e wate r

supplie d b y th e mimicipa

l wate r systemar e not o f concem , but

lea d level s i n som e portion s ofth e shallo w aquife r ar e high enoug

h tha t i t woul d not

b e saf e to us e tha t groundwater

a s aroutin e sourc e o f

drinkin g water . VII . REMEDIA L ACTIO N OBJECTIVE S EP A guidanc e (EP

A 1994 ) statestha

t EP A should : ...limi t exposur e t o soi l lead level s suc h tha t atypica l (o r hypothetical ) [potentially exposed ] chil d or

grou p o f similarly expose d childre n would hav e a n estimate d risk

o f n o mor e tha n 5 % o f exceedin g th e 1 0 • g/d

L bloo d lea

d level . I n accordanc e wit

h thi s polic y recommendation , the Remedia l Actio n Objective s (RAOs ) a t thi s Operabl e Unit

agree d t o i

n the Consent

Decre e (U.S . Distric t

Court , 1994) ar

e a s follows :

• RAO

- 1 : "N o mor e tha n five percen t

o f a U childre n (ag e 0 t

o 7 2 months ) who liv e a

t thi s site , eithe r no w o r i n the future , will hav e bloo d lead value s highe r tha n 1 0 • g/d L bloo d lea d level. " RAO-2 : "HeaU

h will b e adequatel y protecte d ifth e highes t risk level a t an y sub-locatio n (e.g. , ayard o r

home ) i s aprobabilit

y n o highe

r tha n on e percen

t tha t apopulatio n o f children (ag e 0 to 7 2 months ) residmg a t tha t sub-lo.catio n will excee d abloo d lea d valu e o f 1 5 "g/dL. "

2 2RAO- 1 an d RAO- 2 wer e use d to guid

e th e risk managemen

t proces s fo

r OU9 . Base d upo n the Par t A huma n heah h risk assessmen t

(WESTO N 1996a) , whic h considere d bot h measure d and predicte d bloo d lead levels , i t wa s determine d tha

t RAO- 1 and RAO- 2 ma

y no t b e satisfie d unles s remedia l action s ar

e implemente d to reduc e exposur e an d risk. Accordingly , aFeasibilit y Stud y (FS ) wa s conducte d to develo p an d evaluat e appropriate remedia

l actio n altematives . The F S then adde d the following additiona l RAO :

• Reduc e th e dfrect

exposur e o f lea d incurre d b y children , which will resul t i n optima l risk reductio n throug h effectiv e us e o f resources . III . DESCRIPTIO N O F ALTERNATIVE S A Screenin g Feasibilit

y Stud y (SFS ) wa s prepare d b y EPA , fo r the purpos e o f

identifying and screenmg potentiall y applicabl e technologies , a s wel l a s genera l remedia l altemative s fo

r eac h source . Potentia

l technologies/proces s option s wer e screene d o n the basi s o f

effectivenes s t

o achiev e remedia

l objectives , technica

l and adniinistrativ e feasibility , and cost . Thos e technologie s o r proces s option s tha

t were retaine d are : n o action , dee d restrictions , fencing and poste d waming s durin g constmction , mformation an d educationa

l programs , diversio n ditches , channelization , m-sit

e mixmg , revegetation , simpl e cover , mechanica l excavation , tmc k

hauling , on-sit e repository , an d on-site consolidation . A n additiona

l remedia l ahemative , th e Lak

e Count y Communit y Healt h Progra m(LCCHP) , propose d b y Lak e County , wa s als o retame d fo r consideratio n mth e Feasibilit y Study . Tw o option s wer

e eUminate

d i n th e uiitia

l screenin g analysis . Thes e wer

e soi l washin g an d i

n sit u stabilization . Soi l washui g wa s no t retaine d a s a

n optio n becaus e implementatio n tim e woul d b e lengthy , an

d capita l and operation/maintenanc e cost s woul d b e high . I

n sit u stabilizatio n wa s no t

retaine d a s a

n optio n becaus e o f

hig h capita l and hig h operation/maintenanc e costs . Seve n remedia

l altemative s wer

e analyze d fo

r 0U 9 (ASARCO , 1998) . A descriptio n o f eac h o f thes e ahemative s i s provide d below . In eac h case , 1 2 year s o f implementatio n wa s identifie d t o simplif y cos t conpariso n betwee n altematives . The discoim t rate i s equivalent

to th e rate o f escalatio n o f

futur e costs , or th e mflation rate . I

t i s anticipate d tha

t mos t ofth e expens e wi

U occu r i n th e first twelv e years . I

n eac h cas e (wit

h the exceptio n o f

N o Action ) th e remed

y wil l b e implemente d unti l performanc e standard s hav e bee n satisfied . The duratio n o f aremed y ma y excee d 1 2 year s morder

t o mee t perfomianc e standards . Fo r example , institutiona

l control s woul d b e on-going . Alternative 1 : N o ACTION .

23Capita l Cost : $ 0 Operatio n & Maintenance : $ 0 Year s o f Implementation : Non e The Superfim

d progra mrequfre s tha

t th e "n o action " altemativ e b e evaluate d to establis h a baselin e fo

r comparison . Unde

r thi s alteraative , EP

A woul d take no furthe

r actio n a t th e Sh e to reduc e th e risk

o f exposur e to lead . Alternative 2 : INSTITUTIONA L CONTROL S Capita l Cost : $128,94 0 Operatio n & Maintenance : $ 0 Year s o f Implementation : 1 2 Institutiona

l control s (ICs ) ma

y include zoning/dee d restrictions , permittin g requfrements , temporar y acces s restrictions , and commimit y awarenes s education . Dee d restriction s coul d legally liini

t or prohibi t futur e land us e i

n th e sourc e area . IC s alon e ma y b e a n appropriat

e remedia l actio n altemativ e fo

r som e residential are asoil s sourc e sites . Thi s altemativ e ma y als o b e a n elemen t o f other ahematives ; i

f so , temporar

y acces s restrictio n suc

h a s fencin

g and poste d waming s woul d only b e use d t o physicall y contro l acces s t o the residentia

l are asoil s durin g constmctio n activities . Alternativ e 3 : CONTAINMEN T (SURFAC

E WATE R CONTROL)/IC S Capita l Cost : $432,18 0 Operatio n & Mamtenance : $ 187,02 0 Year s o f Implementation : 12 , o r unti l performanc e standard s ar e achieve d Altemativ e 3 fo

r th e residentia

l are asoil s include s the IC s describe d i n Altemativ e 2 combmed wh h surfac e water

containment . The contauiment componen

t ofthi s altemativ e include s surfac e water confrol method s such a s diversio n ditche s and culverts . Th e diversio n ditche s woul d b e constmcte d t

o diver t surfac e wate r

flow and run-o n awa

y fromand around the sourc e areas . Covere d culvert s woul d b e constmcte d to conduc t surfac e wate

r flow through mor

e populate d areas . Thes e confrol s woul d reduc e th e potential fo r transpor t o f metal s awa

y fromthe sourc e are aand , therefore , reduc e metal s impact s t o surfac e wate r or other areas . Operatio n an

d maintenanc e requirement s woul d include maintenanc e o f ditche s and culverts , modification o f deeds , permit

processing , an

d educationa

l activities .

2 4Alternativ e 4 : CONTAINMEN T (SOURC E SURFAC E CONTROL)/IC S

Capita l Cost : $868,64 0 Operatio n & Mamtenance : $308,22 0 Year s o f Implementation : 12 , or unti l performanc e standard s ar e achieve d Thi s altemativ e include s th e IC s describe d i n Altemativ e 2 combine d wit h method s fo

r sourc e surfac e containment . Th e containmen t componen

t ofthi s altemativ e woul d b e base d o n sourc e surfac e contro l option s mcludin g soi l covers , in sit u mixing , and revegetation . Soil cove r involve s addin g additiona

l fill t o isolate the impacte d surfac e soil . I n sit u mixing involve s tillin g surfac e soi l wit h deeper soi l to reduc e surfac e soi l lea d concentration s t o acceptabl e levels . Revegetatio n involve s plantin g appropriate cover vegetatio n to lesse n infiltration , leaching , an d erosion . Operatio n and maintenanc e requfrement s woul d include maintenanc e o f vegetation , ditche s and culverts , modificatio n o f

deeds , permit

processing , and educationa l activities . Alternativ e 5 : CONTAINMEN T (SURFAC

E WATE R CONTROL , SOURC E SURFAC E CONTROL)/IC S Capita l Cost : $1,291,45 0 Operatio n & Maintenance : $308,22 0 Year s o f Implementation : 12 , or unti l performanc e standard s ar e achieve d Aheraativ e 5 fo

r th e residential are asoil s source s include s th e IC s describe d i n Altemativ e 2 combine d wit

h containment

o f bot h surfac e water

and sourc e surfaces . Surfac e water contro l ma

y b e implemente d throug h diversio n ditche s an d culvert s a s discusse d i n Altemativ e 3 . Th e sourc e surfac e contro l element

o f containmen

t involve s i n sit u mixuig , revegetation , o r

asoi l cove r

a s discusse d mAltemativ e 4 . Operatio n and maintenanc e requfrement s woul d mclud e maintenanc e o f vegetation , ditche s an d culverts , modificatio n o f deeds , permit

processing , an d educationa l activities . Alternativ e 6 : REMOVAL/TRANSPORTATION/DISPOSAL/IC S Capita l Cost : $6,029,89 4 Operatio n & Mauitenance : $281,76 0 Year s o f Implementation : 12 , or unti l performanc e standard s ar e achieve d Thi s ahemativ e include s the IC s describe d u i Altemativ e 2 combme d wit h removal , transport , and disposa l o f residential are asoil s wher e mea n lea d level s ar e greater tha n 3,500 . Th e residential are asoil s woul d b e excavate d b y han d wit h the ai d o f

small conventiona

l earth-movin g equipmen

t an d replace d wit

h clea n fill. Excavate d material s woul d b e haule d b y tmc k to a n on-sit e

2 5repository , consolidate d i n a n existin g on-site tailmg s pile , o r remove d to som

e othe r designate d area . Upgradien

t area s migh

t als o requfr

e remediatio n to prevent

re-contamination . Operatio n an d maintenanc e requfrement s woul d mclud e mauitenanc e o f

vegetation , ditche s an

d culverts , and educationa

l activities . Alternative 7 : LAK E COUNT Y COMMUNIT Y HEALT H PROGRA M (Selecte d Altemative ) Capita l Cost : $3,106,80 0 Operatio n & Mauitenance : $ 1,732,45 0 Year s o f Implementation : 12 , o r unti l performanc e standard s ar e achieve d Altemativ e 7 i s implementatio n ofth e Lak e Count y Communit

y Healt h Progra m(LCCHP) . Th

e progra mcombine s bloo d lea

d monitoring , education , communit y awareness , an

d residence

specifi c respons e action s t

o reduc e lea

d exposure t o childre n i

n Leadvill e an

d surroundin g areas . Thi s progra

mwi U addres s lea

d fromsoi l an d dust , interio r an d exterio r

paint , leade d plumbing fixtures, an

d other potentia l Source s beyon d a

n individua

l residence . Altemativ e 7 wi U als o include institutiona

l confrol s t o ensur

e effectivenes s ofth e LCCHP . Operatio n and maintenanc e activitie s woul d include LCCH P administratio n an

d th e bloo d lea

d monitorin g program . IX . SUMMAR Y O F COMPARATIV E ANALYSI S O F ALTERNATIVE S The following sectio n ofth e RO D compare s th e selecte d altemativ e an d the othe r altemative s usin g the nin e evaluatio n criteri aa s describe d mth e FeasibiUt y Stud y (ASARCO , 1998) . Overa U Protectio n o f

Huma n Healt h an d th e Envfronmen

t Altemativ e 7 will provid e the mos t comprehensiv e protectio n o f huma n healt h and the envfronmen

t fromlead , sinc e i

t addresse s no t

onl y lead i n so U but als o lea d i n othe r source s such a s dust . Ulterio

r and exterio r

pamt , and drinkin g water . Altemative s 5 and 6 provide les s protectio n sinc e they d o no t addres s al l lea

d sources . Alteraative s 3 and 4 provide faf r protectio n sinc e they addres s surfac e water contamination , bu t

d o no t addres s multipl e source s oflead . Altemativ e 2 woul d provid e faf r to poo r protection . Institutiona

l control s ma

y b e sufficien

t m som e case s t o protec t

huma n health , bu

t thi s altemativ e woul d not

manag e surfac e water . Altemativ e 1 provide s n o protection .

2 6Complianc e wit h ARAR s Applicabl e requfrement s are defme d b y th e NC P a s thos e cleanu p standards , standard s o f

confrol , and other substantiv e envfronmenta

l protectio n requfrements , criteria , or limitation s promulgate d under federa l or state la w tha t specifically addres s ahazardou s substance , poUutant , contaminant , remedia l action , location , or

other cfrcumstance s a

t asite . It shoul d b e note d tha

t whil e a requfremen

t ma y no t b e applicabl e a s amatte

r o f law , arequiremen

t ma y stif f b e "relevant

and appropriate " i f

i t regulate s or

addresse s problem s o r

situation s sufficientl

y simila r t o thos e encountere d a

t th e subjec t

sit e tha t it s us e i s well-suite d to the particula r site . ARAR s are groupe d int o thre e categories : chemical-specific , action-specifi c an d location-specific . Altemativ e 1 doe s no t satisf y selecte d ARAR s excep t

marea s wit

h a n acceptabl y low risk

fo r lea d exposure . Location-specifi c ARAR s woul d b e addresse d unde r Alteraativ e 2 . Institutiona

l control s woul d provid e som

e protectio n t o th e communit y fromdfrec

t exposure . Under

Altemative s 3 , location

specifi c and chemical-specifi c ARAR s woul d no t b e addresse d wher

e source s remain i

n thef r existin g condition . Action-specifi c ARAR s woul d b e partiall y satisfie d through stor mwater controls . For

altemativ e 4 , chemical-specifi c and location-specifi c ARAR s woul d b e addressed . Action-specifi c ARAR s woul d b e partiall y addresse d excep t fo r stor mwate r control . Ahemative s 5 , 6 , an d 7 woul d compl

y wit h al l ARARs . Long-Ter mEffectivenes s an d Permanenc e Alteraativ e 1 doe s not

reduc e residential risk, whil e Altemativ e 2 coul d b e somewha t effective b y controllmg/limitin g fiiture use . Alteraative s 3 , 4 , and 5 provid e amoderate degre e o f long-ter m effectiveness , bu t

recontammatio n i s likel y and thes e alteraative s d o no t addres s all lea

d sources . Altemativ e 6 woul d provid e th e highes t degre e o f long-ter meffectivenes s and permanenc e fo r soils ; however , i

t doe s no t addres s other

potentia l lea d source s and woul d requfr e long-ter m operatio n an

d maintenanc e ofa n on-site repository . Aheraativ e 7 woul d provid e long-ter m effectivenes s fo

r man y lea d sources . Reductio n o f

Toxicitv . Mobility , or

Volum e Through Treatment Non e ofth e alteraative s reduc e toxicity , mobiUt y or volum e through treatment . Short-Ter mEffectivenes s Alteraativ e 1 ha s n o short-ter meffectiveness . Alteraativ e 2 woul d b e somewha t effective b y controllin g us e o f

som e sourc e areas . Ahemativ e 3 coul d hav e goo d short-ter meffectivenes s m reducmg the potentia

l fo r surfac e wate r

impacts . Altemative s 4 , 5 , and 6 pos e highe r relativ e

2 7short-ter

mrisks to resident s an

d worker s compare d t o other altemative s b y virtu e o f

disturbin g contaniinate d surfac e soils . Altemativ e 7 woul d hav e the greates t overal l short-ter

meffectivenes s b y prioritizin g interventio n and remediatio n in case s o f children wit

h elevate d bloo d lea

d level s couple d wit

h proactiv e identificatio n an d abatement ofth e mos t

significan t source s oflea d exposure mresidentia

l areas . Implementabilit

y Altemativ e 1 doe s no t

requfr e unplementation . Commimif y Protectiv e Measure s (Altemativ e 2 ) woul d b e eas y to implement ; however , th e administrativ e aspect s suc h a s dee d restriction s coul d pos e difficultie s menforcement . Altemativ e 3 woul d b e relatively simpl e to implemen t smc e mos t ofth e surfac e wate r

control s coul d b e implemente d o n publi c land or easements . Altemative s 4 and 5 woul d b e relativel y eas y to unplemen t excep t fo r acces s and spac e limitations . Alteraativ e 6 woul d b e difficul

t to unplemen

t du e t o spac e constriction s mmos t residentia l yards . Alteraativ e 7 coul d b e mor

e easil y implemente d becaus e th e framework fo r the Lak e Count y Communit

y Healt h Progra m(LCCHP ) i s currentl y i

n place , atrus t

fun d ha s bee n estabhshe d t

o pa y fo r it s operation , an d the implementatio n woul d b e a n extensio n ofth e current

Kid s Firs t Program . Cos t Alteraativ e 1 ha s n o associate d cost . Ahemative s 2 and 3 hav e arelativel y low cost , bu t do not satisf y th e remedia

l objective . Altemative s 4 and 5 ar e moderately priced , but

d o not satisf y the remedia l objective . Aheraativ e 6 i s the highes t cos t aheraative , bu t

doe s no t addres s all the source s oflead . Alteraativ e 7 woul d satisf y th e remedia

l objectiv e a

t amoderat

e cos t a s compare d to other ahematives . Suppor t Agenc v Acceptanc e Th e Colorad o Departmen

t o f Publi c Healt

h and the Envfronmen

t ha s participate d u

i the decision

makin g proces s and concur s wit h th e implementatio n o f

Altemativ e 7 sinc e residentia l soil s and additiona l source s oflea d woul d b e controUed . Communit y Acceptanc e Base d o n publi c comment s receive d o n the LCCHP proposal , the Communit y appear s to accep t th e preferre d ahemative . (Se e Appendi x B fo r publi c comment s and EPA' s responses. ) Altemativ e 7 (LCCHP ) ha s the suppor t o f Lak e Coimt y publi c healt

h official s an d the CDPHE , a s wel l a s electe d representative s frombot h th e Cit y o f Leadvill e and Lak

e County . Commimit

y participatio n in , an

d stron g suppor

t fo r th e Kid s Ffrs

t Progra mals o indicate s communit y acceptance .

2 8X . SELECTE D REMED Y

Base d upo n consideratio n ofCERCL A requfrements , the detaile d analysi s o f ahemative s an

d publi c comments , EP

A ha s determine d tha

t th e LCCH

P alteraativ e presente d i

n th e Fina l Feasibilit y Stud y (ASARCO , 1998) , a s modified below , i s th e appropriat e remed y fo r residentia l populate d area s h

i 0U9 . Alternativ e 7 : Lake Count y Communit

y Healt h Progra m Descriptio n Altemativ e 7 , th e LCCHP (simila r to th e Lea

d Ris k Reductio n Progra

mdefined ui the WAMP [ASARC O 1994]) , integrate s avariet y oflea d interventio n methods . Th e LCCH P combme s bloo d lea d monitoring , education , communit y awareness , an

d residence-specifi c respons e action s t o reduc e the risk

oflea d exposure to childre n i n Leadvill e an d surroundin g residentia l areas . Thi s progra mwi U addres s lead fromsoi l an d dust , ulterio r and exterio r

paint , leade d plumbing fixtures, an d other potentia l source s beyon d a

n individua

l residence , A n extensiv e educatio n and mterventio n progra mt o manag e lead exposur

e a t th e sit e i s a n integra l par t ofth e remedy . Th e educatio n progra mwil l focu s o n raisin g publi c awarenes s about risks fromlea

d and encourag e participatio n i n th e Lak e Count y Communit

y Healt h Program . Educatio n will mclud

e uidividua

l face-to-fac e consultation s wit h resident s and customize d recommendation s fo

r specifi c action s tha

t wil l reduc e th e residents ' risk to lea d exposure . Th e recommendation s mad

e t o eac h resident

ar e base d o n th e result s o f

envfronmenta

l lea d samplin g a t thef r home s and specifi c hiformatio n collecte d b y th e progra mabout thef r daily habit s and activities . Follow-u

p education , consultation , and interventio n will contmu e to b e provide d to familie s wit

h youn g childre n b y the Lak e Count y Healt h Department

through thef

r blood-lead monitorin g program . Women , Infants , and Children (WIC ) progra man d Hea d Start . Residentia l propert y owner s with

m0U 9 ma

y reques t a n mvestigatio n oflea d level s msoil , dust , pam t an d water o n the property . Propert

y owner s ma

y reques t are-mvestigatio n i

f condkion s change . The LCCHP include s voluntar y bloo d lea

d monitorm

g (wit h financia l incentives , a s appropriate ) fo r al l children ag e 6-7 2 month s an d voluntar y bloo d lea

d monitorin g fo

r pregnan t and nursm

g women . Ifth e concentratio n oflea d in bloo d o f achil d or

fo r apregnant

or nursin g woma

n exceed s the bloo d lea d criterion , or

ifth e concentratio n oflea d exceed s aspecifie d set o f trigge r criteri afo r

2 9on e or

mor e ofth e envfronmenta

l medi aa t aresidence , then appropriate action s wil l b e take n to addres s th e exceedance . Th e trigger criteri awer

e selecte d b y considerin g th e mitia l trigger s use d fo r the Kid s Ffrs

t Progra mi n additio n t o new infomation obtaine d through the baselin e huma n healt h risk assessment . Thes e trigger criteri aare summarize d below : Bloo d Lea d greate r

tha n o r equa l to 1 0 micrograms/decilite r Soil greate r

tha n o r equa l t o 3,50 0 part s pe

r millio n Dus t greate r

tha n or equa l to 2,00 0 part s pe

r miUio n Pam t Interio r

or exterio r paint , i n poo r condition , wit

h the following lea

d level s greater tha n o r equa l t o 1 milligram/centmieter " - Educatio n greater tha n o r equa l t o 6 milligram/centimeter

^ - Activ e Remediatio n Ta p Water greate r

tha n o r equa l t o 1 5 micrograms/Ute

r Whe n on e o r mor e ofth e trigger

criteri aar e exceeded , awor

k grou p wil l evaluat

e arang e o f differen t respons e actions . Th e wor k group , t o b e establishe d and manage d b y Lak e County , will evaluate al l envfronmenta

l and bloo d lea

d dat afo r apropert y an d provid e opinion s o n appropriat e respons e actions . Membership ofth e wor k grou p will include representative s o f Lak e Coimty , the Colorad o Department

o f Publi c Healt

h an d Envfronment , an

d ASARCO . The opinion s ofth e wor k group , a s approve d b y EPA , shal l constitute th e respons e actio n under CERCLA . The mos t appropriate respons e action s will b e determine d b y evaluatin g the natur e and extent

o f the exceedance , overal l protectivenes s ofth e action , complianc e wit h apphcabl e or

relevan t and appropriate requfrements , long-ter meffectivenes s and permanence , short-ter meffectiveness , implementability , cos t

effectiveness , and communit y impacts . Th e wor

k grou p als o will conside

r the view s ofth e propert

y ovraer . N o respons e actio n wi U b e take n without

th e permissio n ofth e propert y owner . A

n extensiv e educatio n an d uiterventio n progra mt o manag e lea

d exposur e a t th e sit e will b e a n uitegra l componen

t o f eac h actio n considered . The selecte d Remed

y als o mclude s th e following mstitutiona l controls , t o b e develope d durin g desig n ofth e remedy , t o ensur e effectivenes s ofth e LCCHP . ASARC O and Lak e Count y will b e responsibl e fo

r implementin g an d maintamin g thes e institutiona l controls . 1 . Th e creatio n ofa n overla

y distric t to provid e notificatio n and information regardin g th e LCCHP , includin g requfrements tha t specif y excavatio n activitie s or other use s woul d resu h mreferra l ofth e propert

y owne r to th e LCCHP .

3 02 . A dat amanagemen t and fracking syste msuch a s acompute r database , t

o mainta m sampling , respons e actio n and other hiformatio n relate d t

o mdividua

l lot s o r propertie s withi n OU9 . Thi s infomiatio n woul d b e availabl e to intereste d partie s subjec t t o notificatio n throug h th e overla y district . The dat amanagemen t syste m w mb e accessibl e b y all partie s ofth e LCCH P wor k group . Sinc e the LCCHP i s a"pilo t project " tha

t involve s anumbe

r o f innovativ e approaches , i

t include s ongoui g revie w to ensur

e tha t th e progra

mi s operatin g a s intende d and tha t huma n healt h i s beui g adequatel y protected . Th e revie w sha U uiclude : S Evaluatio n o f

participatio n o f

are aresident s i

n th e bloo d lea

d monitoring an

d envfronmenta

l medi asamplin g programs . S Specia

l effor t to ensur e collectio n o f

pafred bloo d lea

d an d environmenta

l lea d dat a wheneve r possible . S Creatio n an d applicatio n o f aweU-documente d qualit

y assuranc e pla

n t o ensur e tha t bloo d lea d an d envfronmenta

l dat aar e collecte d and analyze d i

n the proper manner , an

d tha t th e dat aar

e accuratel y entere d int

o a n ongoin g databas e suitabl e fo r scientifi c evaluation . S Annualreportuigo f summar y statistics . Give n tha t hazardou s substance s wil l rema monsite under

the selecte d remedy , EP

A als o wi U conduc t afive-year

revie w pursuant

to Sectio n 12 1 ofCERCL A to ensur e tha t the remed y i s protectiv e o f

huma n healt h an d th e envfronment . I n addition , th e remed

y wil l b e evaluate d b y agrou p o f outsid e scientists . Detail s o n how thi s group will b e selected , operate , an d evaluat e th e progra

mwill b e mclude d mthe wor k pla n fo r th e Lak e Count y Communit

y Heah h Program . EP A shal l establis h performanc e standard s to defin e th e proces s and criteri ab y which the remed y will b e terminated . Th e perfomianc e standard s wi U b e identifie d ma

n addendumto the remedia l design . Th e CDPH E wil l b e provide d a

n opportunit

y fo r consultatio n an d concurrenc e h i accordanc e wit

h the National Contmgenc y Plan . ASARC O an d loca l official s wi

U als o b e consulte d u

i th e developmen

t ofth e performanc e standards . The following section s discus s respons e action s associate d wit h eac h ofth e trigge

r criteria . Respons e action s woul d b e evaluate d o n acase-by-cas e basi s b y the wor k grou p and ma y b e combine d to for

mthe mos t

effectiv e remedia

l solution .

3 1Bloo d Lea d Th e bloo d lead trigge

r leve l i s independent

o f trigge r criteri afo r soil , dust , paint , and water . I n th e even t tha t achil d o r pregnant o r nursm g woma n ha s abloo d lea

d level greater

tha n or equa l t o 10* g/dL , appropriate respons e action s wil l b e taken , regardles s o f whethe r medi atrigge

r criteri a hav e bee n exceeded , to reduc e tha t exposure . The LCCH

P wi U provid e fo

r continue d monitorin g o f childre n wit

h elevate d bloo d lead concentration s beyon d the ag e o f six , ahhough thos e childre n woul d b e beyon d th e ag e grou p a t highes t risk fromexposur

e to lead . Th e respons e action s to b e considere d fo

r identifie d potential source s oflea d exposure , resultin g i n bloo d lea

d concentration s greater tha n o r equa l tolO * g/dl , sha

U mclud e an y ofth e action s describe d belo w fo r soils , dust , pauit , an d water . I

n addition , othe r

potential lea

d source s beyon d a

n uidividua

l residence , and withi n 0U9 , ma

y b e considere d b y th e LCCHP wor k grou p fo r remediatio n and/o r

educatio n t o addres s exposure . Residentia l Soil s The trigge r criterio n fo

r residential soi l remediatio n unde r the LCCH

P is : soil-lead concentratio n greater tha n o r equa l to 3,50 0 ppm . The followm g respons e action s coul d b e take n fo r residentia l soils .

• N o Action : Thi s respons e ma y b e implemente d i

f soil-lead concentration s ar e les s tha n 3,500ppm .

• Contauiment : Thi s optio n uiclude s the following mstallatio n ahemative s t o contau i soils . AUeraative s Uste

d here ma y b e use d i

n combinatio n o

n an y give n property . Fo r example , so d placement

coul d replac e existm

g yar d an d aconcrete ca

p ma y b e use d t o replac e adir

t driveway . Soil cap : Borro w soi l place d over impacte d areas . I n sit u mixing : Mixin g o f

surficia l soil s havui g lea

d concentratio n abov e 3,50 0 pp mwit

h imderlyin g unimpacte d soil s coul d b e performe d to reduc e lea d concentration s to acceptabl e levels . Home s wit h soil-lead concenfration s greate r

tha n 3,50 0 ppmmthe 6-1 2 inc h dept h mterva l ar e no t considere d amenabl e t o thi s altemativ e du e to th e difficult y mmixm

g to the depth s require d to achiev e the objective . So d placement : So d place d ove r impacte d soils . Compacte d cla

y cap : Compacte d cla

y place d ove

r impacte d area s wit

h a minimu mone-foo t

silt y o r sand y protectiv e laye

r to maintain ca

p integrity .

3 2Spraye d asphalt : Spraye d asphal t place d over

impacte d area s and covere d wit h soi l or opaqu e reflectiv e paint

to protec t the asphal t

fromultraviolet ligh t an d retar d oxidation . Asphahi c concrete : Asphal t fo r pavm g grade s o r specia l blend s mixe

d wit h we U graded , crushe d aggregate , place d over impacte d areas . Concrete cap : Concrete place d ove r prepare d impacte d areas . Multilayere d cap : Ca

p compose d o f

som e combinatio n o f

natura l soils , soi l admixtures , clay , spray-o n asphalt , asphalti c concrete , or Portlan d cemen

t and place d ove

r impacte d areas .

• Diversio n ditc h constmction : Constmctio n o f diversion s and/o r

culvert s ma

y prevent run-o n to sourc e area s and reduc e bot h erosiona l an d leachm g releas e o f th e metal s from asource .

• Removal : Remova

l o f soi l woul d b e accomplishe d through han d excavatio n wit h th e ai d o f mechanica

l excavatio n equipment . The remova l dept h woul d b e decide d o n acase-by-cas e basi s base d o n site-specifi c infomiation , but woul d b e n

o mor e tha n 1 2 inches . Durin g excavatio n and fransport, dus t suppressio n ma

y b e necessary . Afte

r excavation , borro w materia l woul d b e transporte d t o the residenc e and placed . Yard s woul d b e revegetated , generally wit h sod . I n instance s where remainin g soil s ma

y excee d th e trigger

criterion , such soil s woul d b e subjec t t o institutiona

l controls . Excavate d materia

l coul d b e pu t

t o beneficia

l re-us e a s non-surficia

l fill materia

l or coul d b e remove d t

o asuitabl e on-sit

e repository . In-Residenc e Dus t Potentia l source s o f

lea d fo r in-residenc e dus t

are : lead-base d paui t

h i poo r condition , bar

e soi l areas , gardens , street s an d alleys , tailings , and min e waste . Dus t

i s transporte d int

o th e hom e b y wind o r o n hem s take n outsid e and then retume d inside . The frigger level fo r in-residenc e dus t

i s lea d concentration s greate r

tha n or equa l to 2,00 0 ppm . Respons e action s woul d be :

• N o Action : Residence s wit h dust-lead level s betwee n 50 0 and 2,00 0 pp mwill b e mforme d abou t lea d dus t abatement

method s an d offered us e o f aHig h Efficienc

y Particulate Af

r (HEPA ) vacuum .

• Physica

l Protectiv e Measures : Thi s respons e actio n mclud e sealm g of f unfinishe d basements , attics , or

craw l spac e area s to Ifrni

t exposure t o ulterior

lead-dust . 33• Educatio n Program : Thi s respons e ma y b e enacte d t o educate resident s o n ho w to effectivel y reduc e lead-dus t

when cleaning . Demonstration s or brochure s ma

y b e used .

• Remova

l and Disposal b v Mean s o f Decontaminatio n or

Replacement : On

e or a combinatio n ofth e following method s ma y b e considere d fo

r removin g ulterior leaddust : Vacuu mal l mterior livm g space s wit

h aHEP A vacuum . Dus t

ca n b e dispose d o f

maRCR A Subtitl e D landfil

l a s i t i s househol d waste . Dam

p mo p all floors, wuido w weUs , and other woo d wor

k wit h atrisodiu mphosphate (TSP ) cleanin g solution ; clea

n fiiraace duct s usin g the EPA-approve d progra mfo r duc t cleaning ; an

d placement

o f mat s a t entryway s s o tha

t shoe s ma y b e appropriatel y shake n o r wipe d befor

e entering , reducin g the amoim t o f soi l enterin g the residence . Interio r and Exterio r

Pain t Residence s ma

y hav e interior

and/o r exterio r paui t tha t i s lead-based . Lead-base d pam t u i poo r conditio n ma

y contribute to lead exposure throug h mhalatio n and ingestio n o f dust , or dfrec t consumptio n o f

pain t chips . Dependin g o n th e paint' s lea d concenfratio n and conditio n the foUowin g respons e action s ma

y b e considered :

• N o Action : Thi s respons e actio n wil l b e implemente d i f lea d level s ar e les s tha n 1 mg/cm " or i f n o lead-base d paui t

i s identified .

• Education . Contamment . Covering , o r Removal : I

f pain t contain s lea

d abov e 1 mg/cm " an

d i s u i poo r conditio n (peeling , chipping , chalking ) or coatin g a fliction-surface, education , risk coimselmg , an

d information o n action s they ma y take themselve s wil l b e provide d t o residents . If pauit ha s lea d level s greater

tha n or equa l to 6 mg/cm^ , and i s i

n poo r condition , activ e remediatio n woul d b e recommended . I f

either encapsulatio n o r

remova l i s chose n fo

r remediation , th e remediate d area s will hav e asurfac e paint-lead level n o greater tha n 1 mg/cnf

.

• Communit

y Protectiv e Measures : HU D disclosur

e requfrement s fo

r lead-base d pam t will b e relie d upo n t o notif y potentia l fiiture buyer s ofan y potentia l lead-relate d risks. Drinkui g Wate r Residence s ma

y hav e drinkin g wate r

tha t contaui s lead . Lea

d mdrinkin g water

ma y b e associate d wit h lea d solder , lea

d plumbing , o r

lea d allo y fixtures. Th

e actio n level fo

r lea d i n drinkin g water i s lea d concentration s greater

tha n or equa l to 1 5 • g/L . Lea

d concentration s i

n drinkin g wate

r ca n b e measure d an

d th e following respons e action s ma y b e considered :
3 4• N o Action : Thi s respons e actio n coul d b e implemente d ifth e lea d concentratio n m drinkin g wate r

i s les s tha n 1 5 • g/l .

• Altemativ e Water

Supplv : Thi s respons e actio n coul d provid e the replacemen t o f unsuitabl e drinkin g water

wit h bottle d water , municipa

l water , or ahousehol d wate r treatment syste mcoul d b e instaUed .

• Replacement : The remova l and replacement

respons e coul d b e appropriate fo r residence s wit

h lea d mdrinkm

g wate r fromlea d pipin g o r

soldering . XI . STATUTOR Y DETERMINATION S Unde r CERCL A Sectio n 121 , EP

A mus t selec t aremed y tha t i s protectiv e o f

huma n healt h and th e envfronment ; tha

t complie s wit

h ARARs ; i s cos t

effective ; and utilize s pennanen t solutions , and altemativ e treatment

technologies , o r

resourc e recovet

y technologie s to th e maxunu mextent practicable . In addition , CERCL A mclude s apreferenc e fo r remedie s tha

t mclud e treatment

whic h permanently an d significantly reduce s th e volume , toxicity , or mobilit y ofhazardou s waste s a s a principa l element . Th e Selecte d Remed y doe s no t satisf y the statutor

y preferenc e fo

r treatment a s aprincipa l elemen t ofth e remedy . The following section s discus s how th e Selecte d Remed y meet s statutor y requfrements . Protectio n o f

Huma n Healt h an d th e Environment

- Th e selecte d remed

y i s protectiv e o f

huma n healt h and the envfronmen

t b y addressin g addhiona

l source s oflea d i

n conjunctio n wit

h soi l remediatio n (i f

requfred) . Treatment

i s not practical an

d therefor e i s no t used . Complianc e wit h ARARs

- The selecte d remed y wil l compl

y wit h all ARAR s identifie d mAppendi x C to thi s ROD . N o waive r o f ARAR s i s expecte d to b e necessaty . Cos t Effectivenes s - EP

A ha s detennine d tha

t th e Selecte d Remed

y i s cos t effective i n mitigatin g the principa

l risks pose d b y contaminate d residential soils . Sectio n 300.43 0 (f)(ii)(D ) ofth e NC P requfre s evaluatio n o f cos t effectiveness . Overa

U effectivenes s i s determine d b y th e following thre e balancm g criteria : long-ter

meffectivenes s and permanence ; reductio n o f

toxicity , mobility , an d volum e throug h treatment ; and short-ter m effectiveness . Overal l effectivenes s i s the n compare d to cos t to ensur e tha t the remed y i s cos t effective . Th e Selecte d Remed y meet s th e criteri aan d provide s fo r overal l effectivenes s i

n proportio n t

o it s cost . The estimate d cos t fo r the Selecte d Remed

y i s $4.8 4 milUon . T o the extent

tha t th e estunate d cos t

ofth e Selecte d Remed

y exceed s the cos t

fo r other alteraatives , th e differenc e i n cos t i s reasonabl e when relate d to th e greate r overal l effectivenes s achieve d b y the Selecte d Remedy . 3 5Utilizatio n o f Permanen t

Solution s an d Satisfie s th e Preferenc e fo r Treatmen t

tha t Reduce s Toxicity , Mobility , o r Volume

- Th e selecte d remed y utilize s pemianen

t solution s t o th e maximu

mextent practicabl e bu t

doe s no t satisf y the preferenc e fo

r alteraative s tha

t involv e treatment

t o reduc e th e toxicity , mobility , o r volum e o f contamination . Lon g Ter mEffectivenes s an d Permanence

- Ris k t o resident s would b e reduce d du e to selectio n ofthi s remedia

l actio n fo r th e reductio n o f

total lea d exposures . Thi s remed

y woul d resu h mwast e bein g lef t i n place . Reductio n o f

Toxicity , Mobilit y o r

Volum e throug h Treatment

- The selecte d altemativ e doe s no t

involv e treatment ; however , th e total lea d exposur e fo r agiven residentia l living envfromnen

t will b e reduced . Short-Ter mEffectiveness

- Short-ter mrisks t o worker s an

d resident s ar

e acceptable . Implementability

- Inplementatio n ofth e selecte d remed y i s expecte d t

o b e successful base d o n th e suppor

t o f Lak e Count y official s an d th e CDPHE , a s wel l a s electe d representative s frombot

h th e Cit y o f LeadviU e and Lak e Coimty . Communit

y suppor t fo r the Kid s Ffrs

t Progra mals o indicate s tha

t implementatio n ofth e selecte d remed y will b e successfiil . Thi s altemativ e utilize s common constmction , hom e improvement , cleanm

g equipment , and procedure s defmed i n HU D guidance . Thi s altemativ e allow s fo r flexibility mselectin g th e mos t

appropriate respons e action s o n acase-by-cas e basis , whil e considerin g residen t

need s and preferences . Cos t - Th e estimate d cos t

fo r th e LCCH

P i s $4,839,250
. The cos t

fo r thi s ahemativ e i s mid-rang e wit

h respec t t o other altematives . XII . DOCUMENTATIO N O F SIGNIFICAN T CHANGE S EP A distribute d aPropose d Pla n outlinin g the prefene d alteraative s u i Novembe

r 1998 . The Propose d Pla

n identifie d Altemativ e 7 , th e LCCHP , a s th e prefene d altemativ e fo r the Residentia

l Populate d Area s Operabl e Unit . N o significan t change s hav e bee n mad

e t o the Alteraativ e 7 decisio n describe d i

n th e Propose d Plan . Publi c commen t generally supporte d implementatio n o f the LCCHP . PubU

c comment s and EPA' s response s to thos e comment s ar e attache d a s Appendi x A . The remed

y wil l b e continuall y monitore d fo r effectiveness . An

y problem s wit

h the progra

mwill b e identifie d and adjuste d a s necessaty .

3 6XIII . REFERENCE S

References : 1907 . The Downtow n Distric t o f Leadville , Colorado , Samue l Frankli n Emmon s and Joh n Due r Irving , Govemment

Printin g Office , Washmgton , D.C . 1927 . Geolog y an d Or

e Deposit s ofth e Leadvill e Minin g District , U.S.G.S. , S . F . Emmon s and J . D . Irving . 1987 . Cahfomi aGulc h Remedia l Investigation , LeadvUle , Colorado , CH2 M Hill , May . 1990 . U.S . Burea

u o f Censu s 1992 . Soil Inventot

y and Map , Califomi aGulc h Stud y Area , Leadville , Colorado , Wals h an d Associates , May . 1993 . Fina l Smelte r Remedia l Investigatio n Report , Califomi aGulc h Site , Leadville , Colorado , Wals h and Associates , April . 1994 . Fma l Soil s Investigatio n Dat aReport , Caffomi aGulch CERCL A Site , LeadviUe , Colorado , Volum e 1 , Text , Camp , Dresser

an d McKee , Inc . July . 1994 , Consen

t Decre e betwee n th e Unite d States , Stat e o f Colorado , ASARC O an

d Resunection , Lodge d mU.S . Distric t

Cour t mDenver , Ma

y 17 , 1994 . ASARCO , 1994 . Wor

k Management

Pla n fo r ASARC O fric. a

t th e Califomi aGulc h NP

L Site , Leadvill e CO . Prepare d b y Woodward Clyde . Appendi x B t o th e Consen

t Decree . ASARCO , Incorporated , 1994 . Engineerin g Evaluation/Cos t Analysi s fo

r Park s an d Playgroun d Areas , Operabl e Um

t 9 , Califomi aGulch , LeadviUe , Colorado . Prepare d b y Woodwar d Clyde Consultants , November . ASARCO , Incorporated , 1995 . Engmeerin g Evaluation/Cos t Analysi s fo

r Mui e Waste Piles , Operabl e Un

h 9 , CaUfomiaGulc h Superfim d Site , Leadville , Colorado . Prepare d b y Golder Associates . December . Envfronmenta

l Protectio n Agenc y (EPA) . 1993 . Fma l Screenin g Feasibilit

y Stud y fo r Remediatio n Altemative s a

t th e Califomi aGulc h NPL Site , Leadville , Colorado . September .

3 7Envfronmenta l Protectio n Agenc y (EPA) . 1996a . Baselin e Huma n Healt h Ris k Assessmen

t Califomi aGulc h Superfun

d Site , Leadville , Colorado , Par t A ~ Risk s to Resident s fromLead , p . 8-6 . Prepare d b y Ro

y F . Weston , Inc . Januaty 1996 . Envfronmenta

l Protectio n Agenc y (EPA) . 1996b . Baselin e Huma n Heah h Ris k Assessmen

t Cahfomi aGulc h Superfun

d Site , Leadville , Colorado , Par t B ~ Risk s to Resident s from Contammant s Other

tha n Lead . Prepare d b y Ro y F . Weston , Inc . Januat y 1996 . Envfronmenta

l Protectio n Agenc y (EPA) . 1996c . Baselin e Huma n Healt h Ris k Assessmen

t Califomi aGulc h Superfim

d Site , Leadville , Colorado , Par t C ~ Evaluatio n o f

Worker an d Recreational User

Scenarios . Prepare d b y Ro y F . Weston , Inc . Januat y 199 6 Envfronmenta

l Protectio n Agenc y (EPA) . 1996d . Interi mStatu s Report , Consolidate d Findmg s o f Soil-Lea d Investigation s a

t the Califomi aGulc h NPL Site . Prepare d b y Ro y F . Weston , Inc . June . Woodward Clyd e Consultants , 1994 . Fina l Wor k Pla n fo r Kid s Ffrs t Program , Califomi aGulch NP L Site , Leadville , Colorado . Prepare d fo r ASARCO , Incorporated , Denver , Colorado . Golder Associates , 1998 . Fina

l Residential Soil s FeasibUit y Study , Califomi aGulch Superfun d Site , Leadville , Colorado . Prepare d fo r ASARCO , Incorporated , Denver , Colorado .

3 8Appendi x A SIT E LOCATIO N MAP1 fAppendi x B RESPONSIVENES S SUMMAR YResponsivenes s Summar y

I n Novembe

r 1998 , the Envfronmenta

l Protectio n Agenc y issue d aPropose d Pla n describin g th e Agency' s prefene d aheraativ e to addres s risks to resident s fromlea d i n soil s an d othe r source s withi n Operabl e Un

k 9 ofth e Califomi aGulch Superfand Sit e mLeadville , Colorado . A publi c meetui g to discus s th e Propose d Pla

n wa s hel d i

n Leadvill e o n November

19 , 1998 . Publi c commen

t o n th e Propose d Pla n wa s accepte d fromNovembe r 12 , 199 8 throug h December 14 , 1998 . Th e purpos e ofthi s Responsivenes s Summat y i s t o provid e a

U comment s receive d o n th e Feasibilit y Study , Propose d Plan , o r durin g th e publi c meetmg an d provide the Agency' s respons e to thos e comments . A

U comment s ar

e include d i

n the Adminisfrativ e Recor d fo r thi s project . FEASIBILITY STUD Y Followin g ar

e comment s fromth e Colorad o Department o f Publi c Healt

h an d Envfronmen

t (CDPHE ) o n th e FeasibiUt

y Study . Eac h CDPH

E commen

t i s followe d b y EPA' s response . CDPH E Commen

t 1 Th e tex t fo r Altemativ e 7 shoul d b e revise d t o mor e accuratel y reflec t

the cunen t

Kid s Ffrs t Program' s practic e o f

accommodatin g th e homeowner' s preference s a s par t ofth e Kid s Firs t

Wor k Grou p deliberativ e proces s o f

remed y selection . Typically , th e deliberativ e remed y selectio n proces s associate d wit h Altemativ e 7 shoul d b e maccordanc e wit h the propert

y owner' s preference . I

n addition , th e propert y owne r shoul d full

y understan d an

y institutiona

l control s tha

t woul d b e associate d wit

h leavin g waste s o n his/her

property . Respons e 1 Altemativ e 7 i s base d o n th e Kid s Ffrs t Progra man d ha s bee n designe d to full y conside r th e view s ofth e propert y owner . N o respons e actio n wil l b e conducte d withou t th e pennissio n ofth e propert y owner . A

n extensiv e educatio n and interventio n progra mto manag e lead exposur e a t the sit e wil l b e a n mtegra l componen t o f eac h actio n considered . CDPH E Commen

t 2 Sectio n 3.4.3. 5 ofth e FS mention s variou s mstitutiona l control s such a s lan

d us e controls , dee d restrictions , permitting , etc. , tha t coul d b e use d a s aseparat e remedia l ahemativ e or

a s acomponen

t o f variou s other

remedia l ahematives . However , the FS fail s to present a n m-dept h discussio n ofthi s issue . A mor e detaile d discussio n o f

al l th e potential mstitutiona l control s i s needed , especiaU y adiscussio n o f ho w they woul d appl y to remedia l Ahemativ e 7 (se e previou s comment) . Suc h specific s as : whic h institutiona

l control s will b e employe d fo r the variou saltematives , ho w they will b e employed , an d b y who mthey will b e employe d shoul d b e fliU y discussed . I

n order fo r the F S t o adequatel y evaluat e effectiveness , UnplementabiUt y an d cost , thi s cmcia

l issu e shoul d no t b e defene d unti l th e desig n phas e ofth e remedia l process . (Als o see : CDPH E Genera l Commen t # 2 i n conespondenc e to EP

A date d Ma

y 28 , 1996 , o n th e Draf

t residentia l Soil s FS and Genera

l Commen t # 7 i n correspondenc e date d Januat y 8 , 1997 , o

n th e Redraf

t o f Altemativ e 7 aan

d 7b. ) Also , pleas e refe

r t o EPA' s Draf

t Referenc e Manua

l o n Institutiona

l Confrols , Marc h 1998 , fo r earl y uitegratio n o f institutiona

l confrol considerations . Respons e 2 Alteraativ e 7 , th e Selecte d Remedy , mclude s the following mstitutiona l controls , to b e develope d durin g desig n ofth e remedy , to ensur e effectivenes s ofth e Lak

e Coimt y Commimit

y Healt h Progra m(LCCHP) . ASARC O an d Lak

e Count y wi U b e responsibl e fo

r implementm

g and mamtainm

g thes e institutiona

l controls . 1 . The creatio n o f

a n overla y distric t t o provid e notificatio n and informatio n regardin g th e LCCHP , uicludm

g requfrement s tha

t specif y excavatio n activitie s or

other use s woul d resul t U l refena l ofth e propert

y owner t o th e LCCHP . 2 . A dat amanagemen t and fracking syste msuc h a s acompute r database , to mainta

m sampling , respons e actio n an d other infomiatio n relate d t

o individua

l lot s r o propertie s withi n OU9 . Thi s mformation woul d b e availabl e to uitereste d partie s subjec t to notificatio n through th e overla y district . The dat amanagemen t systemwill b e accessibl e b y al l partie s ofth e LCCHP wor k group . CDPH E Commen

t 3 A n on-site repositot

y fo r th e disposal o f

residential soil s i s mentioned , however , ther e i s no discussio n o f wher e th e repositot

y will b e located . The specifi c location , includin g siz e and adiscussio n o f skin g criteria , shoul d b e uicluded . Accordmgly , State Soli d Waste Regulation s pertauimg to SoU d Wast e Disposal Sit

e and Facilitie s (6CC R 1007-2 ) Section s 2 & 3 shoul d b e include d a s apotentiall y relevant and appropriate ARAR . Respons e 3 An y excavate d soil s will b e remove d to asukabl e on-sit e repositoty . The specifi c locatio n and siz e ofa n on-site repositot

y wi U b e addresse d durin g remedia l design . Pleas e refe

r t o Appendi x C to the Recor d o f Decisio n fo

r acomplet e hstin g o f

a U applicabl e o r

relevant and appropriate requfrements . Specific Stat e Soli d Waste Regulation s ar e identifie d a s ARARs . CDPHE Commen

t 4 The CDPHE , APCD , Regulatio n 1 9 i s currentl y bein g evaluate d a s potentiaU y appUcabl

e o r relevant an d appropriate (ARAR) fo

r lead-base d pam

t abatement

(i.e. , remediations) . The CDPHE , a s yo u know , i s currentl y activel y workm

g wit h E P A Regio n VIII lead-base d pam tprogra

mrepresentative s to detennin e which element s ofthi s regulatio n ma y affec t remedia l activitie s i

n OU9 . An y issue s i n thi s contex t

wil l b e resolve d a s soo n a s possible . Respons e 4 Commen t noted . The agree d upon provision s fromRegulatio n 1 9 hav e bee n mclude d i n the ARAR s table . Appendi x C . CDPHE Commen

t 5 I n thei r Commen t 5 , CDPH E identifie d anumbe

r o f ARAR s fo

r uiclusio n ui th e summatio n o f ARAR s fo r Operabl e Uni

t 9 . Respons e 5 Pleas e se e Appendi x C t o the Recor d ofDecisio n fo

r acomplet e listm g o f all appUcabl

e or relevan t an d appropriate requfrements . CDPH E ha s conciure d wk

h th e compilatio n o f

ARARs . PROPOSED PLA

N FoUowui g are comment s fromCDPH E o n th e Propose d Plan . Each CDPH E commen

t i s followed b y EPA' s response : CDPH E Commen

t 1 CDPHE' s suppor

t tha t the RO D b e revise d to confor

mwit h CDPHE' s understandin g ofth e Kid s Ffrs t Program' s practic e o f

accommodatin g the homeowner' s preference s an d concem s i

n the Kid s Firs t Workgroup' s deliberativ e proces s o f remed y selection . Respons e 1 Pleas e se e EPA' s respons e t o CDPHE' s Commen

t 1 o n th e Feasibilit

y Study . CDPH E Commen

t 2 T o th e extent

possible , and i

n conformanc e wit

h EP A Institutiona

l Contro l (IC ) guidance , likel y IC s associate d wit

h th e selecte d remed

y shoul d b e identifie d and discusse d mthe ROD . Thi s woul d facilitat e abette r understandin g b y the partie s (and participatui g propert y owners ) ofan y duties , obligations , or potential UabiUties tha

t ma y b e associate d wit

h th e implementatio n ofth e selecte d remedy . Respons e 2 Pleas e se e EPA' s respons e t o CDPHE' s Commen

t 2 o n th e Feasibilit

y Study .FoUowui

g ar e comment s fromASARC O o n the Propose d Plan . Eac h ASARC O commen t i s followed b y EPA' s response . ASARC O Genera

l Commen t 1 Throughout

th e Propose d Pla

n i t state s tha t all source s oflea d will b e addressed . Generally , Asarc o support s addressin g al l source s oflead , but a s w e hav e discovere d through the unplementatio n ofth e Kid s Ffrs t Progra mthi s i s impractical , i

f no t impossible . Th e LCCH

P will addres s primat

y source s oflea d exposur e to childre n (i.e. , soil , dust , paint , an d water ) and attemp t to identif y other potentia l pathway s o f lea d exposure . Respons e 1 EP A recognize s soi l a s the primat y pathwa y o f exposure t o the residentia

l populatio n a

t the site . Dust , pam t and wate r ar e other pathway s o f

exposure . Other

potential lea

d source s beyon d a

n uidividua

l residence , an d withu i 0U9 , ma y b e considere d b y th e LCCHP wor k grou p fo r remediatio n and/o r educatio n t o addres s exposure . ASARC O Genera

l Commen t 2 A s ther e ha s bee n som

e conce mraise d regardin g th e accurac y ofth e Superfun d Sit e an d Operabl e Uni

t boundarie s o n th e ma

p attache d to the Propose d Plan , ASARC O support s usin g the Operabl e Un k boundat y ma p include d mthe Consen

t Decree , Appendi x C , Attachmen t 1 (als o presente d a s Figur e 2- 1 mthe Feasibilit

y Study) . Respons e 2 Th e ma p include d a s Appendi x C to the Consent Decre e wil l b e use d to identif y Operabl e Un

k an d Sit e boundarie s fo

r the Record ofDecision . ASARC O Specifi c Commen t 1 Th e propose d pla

n states , "Th

e secon d approac h compare d th e measure d bloo d lea d value s i n are a children wit

h relevant nationa l bloo d lea

d statistic s morde r

t o hel p evaluat e the cunen t

impact s o f

actua l sit e exposure s t o lead. " The compariso n to nationa l bloo d lea

d statistic s wa s aminor

par t ofth e wa y mwhich EP

A use d th e measure d bloo d lead level s h i th e risk assessment . It

woul d b e mor

e accurate t o emphasiz e tha t the bloo d lea d level s wer

e analyze d alon g wit

h conespondin g envfronmenta l dat afo r soil , dust , water , pain

t and other factor s t o help evaluate th e cunen t impact s o f

actual site exposure s t o lead . Respons e 1 Commen t noted .ASARC O Specifi c Commen t 2 Th e propose d pla

n states , "I

n 1991 , geometri c mea

n bloo d lea

d level s mchildren living withui th e sit e boimdarie s were typicall y aroun d 5- 6 • g/dl... " Th e geometri c mea

n bloo d lead level i s asingl e valu e fo r aspecifi c group , no t

a"typical " valu e ma range . The geometri c mea

n bloo d lea

d level fo r th e 28 4 childre n ag e 0-7 2 month s wh o wer e Uvin g within th e ske i n 199 1 wa s 4. 7 • g/dl , a s reporte d o n pag e 5- 3 ofth e Baselin e Huma n Healt h Ris k Assessmen

t (BHHRA) , Par

t A . Th e rang e o f

5- 6 • g/d l doe s no t conespon d wit

h th e value s reporte d fo

r subarea s fromth e Universit

y o f Cmcinnat i stud y use d i n the BHHRA . Geometri c mea n bloo d lea

d level s withu i th e subarea s designate d A- G range d from3. 9 to 6 . 6 • g/dl ; geometri c mea n bloo d lea

d level s fo r th e tw o subarea s within Lak

e Count y bu t outsid e ofth e Superfun

d Sit e boimdarie s were 3. 1 an

d 6. 0 • g/dl . Respons e 2 Commen t noted . ASARC O Specifi c Commen t 3 Ite m2 state s i

n par t tha t "Additiona

l bloo d lea

d dat acollecte d b y [the ] count y healt h agenc y frommor

e tha n 10 0 childre n per

yea r fo r eac h yea r betwee n 199 1 and th e presen t suggest s tha

t the mcidenc e o f children i n th e communit

y wit h bloo d lea

d level s abov e 1 0 • g/d

l i s contmum

g t o fluctuate betwee n 6 % and 9%. " Thi s statement

appear s to overstate th e cunen t commimit

y bloo d lea

d level s observe d m Leadville . Usin g the guideline s fo r dat areductio n estabUshe d mth e mem o to EP A fromDr . Bil

l Brattin , EPA' s toxicolog y consultant (December , 1997) , w e fm d tha t i n 199 7 5.8 % (1 4 children ) o f all 24 0 childre n teste d and livin g withi n the sit e had bloo d lead level s ove r 10 * g/dl . Respons e 3 Commen t noted . ASARC O Specifi c Commen t 4 I n the propose d pla

n i t states , "It wa s conclude d tha

t soi l an d dus t

ingestio n rate s mthi s communit y wer e probabl y somewha

t lower tha n nationa l averag e rate s possibl y becaus e the ground i s frozen o r sno w covere d approxunatel y eigh t month s out

ofth e year . " Whil e ASARC O agree s wit h thi s conclusion , w e woul d lik e to clarif y tha t nationa l averag e rate s fo

r soi l and dus t ingestio n ar

e no t know n an

d tha t the precis e amoun

t o f soi l uigeste d anywher

e i s not well understood . Th e assumption s use d mthe lEUB K model reflec t

result s from avet

y limited numbe

r o f soi l ingestio n studie s alon g wit h modification s to estimate d soi l ingestio n rate s b y ag e grou p s o tha t the predicte d bloo d lea

d level s appea

r to match the observe d values . N o soi l ingestio n studie s specifically suppor t th e age-specifi c soi l ingestio n rate s use d mth e lEUB K model . Othe

r possibl e reason s wh

y th e LEUB K model prediction s and th e bloo d lea d observation s di d no t

matc h i s tha

t the model ma

y fai l to accuratel y predic t

tm e "backgroimd " bloo d lea d level s du e t

o non-soi l sources , which ma y lea d t o a failur e to accuratel y predic t

bloo d lea d uicrease s du e t o soi l exposure ; an d the model ma

y overestunate the importanc e o f

soi l lead exposure fri predictin g bloo d lea d levels .Respons e 4

Commen t noted . ASARC O Specifi c Commen t 5 Wit h respec t t o th e propose d trigge

r criteri afo r mterior an d exterio r paint wit h lea d concentration s abov e 1 mg/cm ^ an d i n poo r condition , Asarc o woul d lik e to reiterate it s desfr

e t o implemen

t atiere d approac h where : 1 ) pam

t remediatio n abatement

i s performe d i f

lea d pam t concentration s ar

e foun d to b e greater tha n 6 mg/cm ^ an d pain t i s in poo r condition ; 2 ) education , an d propert y owner requfrement s (base d o

n applicabl e federa

l laws) , woul d b e th e measure s take n fo r home s wher

e lead pam

t concentration s ar

e foun d t o b e belo w 6 mg/cm

^ an d abov e 1 mg/cm^ , o r

wher e lea d pain t concenfration s are abov e mg/cm ^ an d pain t i s h i goo d condition ; an

d 3 ) n o actio n i s take n i

f lea d pain t concentration s ar

e 1 mg/cm

^ or lower . Educatio n will b e performe d o n issue s such as : encapsulation , avoidance , car e an d mauitenanc e o f pakite d surfaces , and precaution s t o b e take n durin g futur e remodelin g project s b y homeowner . Asarc o believe s tha

t the 6 mg/cm

^ an d poo r

conditio n actio n criteri acurrentl y beui g use d under th e Kid s Ffrs t Progra mfo r remediatio n o f

pain t i s protectiv e o f

huma n healt h and the envfronment , and uphold s the origina

l mten t ofth e Consent

Decree . A s mdicate d i

n th e Wor k Are aManagemen

t Pla n (WAMP) , th e concep t o f community-base d lea

d reductio n progra

msuch a s th e LCCH

P wa s develope d a s a

n alteraativ e t o wholesal e soi l remova

l t o addres s source s oflea d exposur e to youn g children beside s soil . Asarc o voluntarily agree d t o remediat e home s tha

t pos e significan

t lea d pain t risks (i.e. , 6 mg/cm

^ o r greater and pam t mpoo r condition ) a s par

t ofth e overal l lea

d risk reductio n program , even though lea d pain t abatement i s no t aCERCL A action . Th e voluntat

y natur e ofth e agreemen

t to uiclud e lea d pam t i n a communit y progra mattest s to Asarco' s suppor t fo r reductio n oflea d risks myoung children . Respons e 5 The selecte d remed

y include s atiere d approac h to lead-base d pain t remediation . If

lea d level s ar e les s tha n 1 mg/cm^ , no actio n will b e taken . I f paint contain s greater

tha n o r equa l t o 1 mg/cm " and i s mpoo r conditio n (peeling , chippmg , chaUcing ) o r coatin g afiiction-surface, education , risk counseling , and frtformation o n action s they ma y take themselve s will b e provide d t o residents . If pain t ha s lea d level s greater tha n or equa l to 6 mg/c m^

, an d i s mpoo r

condition , activ e remediatio n woul d b e recommended . I f either encapsulatio n or

remova l i s chose n fo

r remediation , the remediate d area s will hav e asurfac e paint-lead leve l n o greater

tha n 1 mg/cm^ . ASARC O Specifi c Commen t 6 Asarc o feel s tha

t "an d accessible " shoul d b e adde d to th e trigge r criteri afo r soil . The LCCH

P i s arisk base d program , thus , Asarc o feel s tha t th e conditio n o f

soil s o r mor e specifically th e accessibilit y t o soi l i s a n importan

t par t ofth e trigger

criteri afo r soil . Th e exposure pathwa y fo r soil s i s greates t

when poo r vegetativ e condition s exis t such a s abar e are ai

n th e yard or

agarden are awher

e bare soil s ca

n b e expose d fo

r par t ofth e year . If

there i s agoo d yea

r round vegetativ e cove r

the pathwa

y i s blocked . Th e LCCH P Wor k Grou p shoul d hav e th e opportunit y to recommend , and resident s shoul d hav e th e opportunit y to select , educatio n an dpossibl y som e typ e o f voluntat y mstitutiona

l control s an

d no t destro y a n existm g vegetativ e cover . Als o fo r open areas , th e Wor

k Grou p coul d recommend vegetativ e enhancemen t without destroymg the nativ e vegetatio n tha

t exists . Respons e 6 The selecte d remed

y offers awid e rang e o f

option s to addres s potentia l exposur e fromsoil s greater

tha n o r equa l t o the trigger

criteri afo r soil . Containmen

t i s on e ofth e option s an

d coul d rel y upo n vegetatio n a s abanie r

to an y exposure . ASARC O Specifi c Commen t 7 Th e following referenc e i s missin g a s refene d to o n pag e 4 fo r (U.S . Distric t

Court , 1994) . "h i the Unite d State s Distric t Cour t fo r the Distric t

o f Colorad o (U.S . Distric t

Court) . 1994 . Consen

t Decre e wit

h ASARCO , Incorporated , Resunectio n Minm g Company , Newmont

Minui g Corporation , and th e Res-ASARC O Jom t Venture . Augus t

25. " Respons e 7 Referenc e to th e Consent

Decre e i s mad

e i n the Recor

d ofDecisio n selectin g th e remed y fo r Operabl e Unit 9 ofth e Califomi aGulc h Superfun d project . EP A receive d anumbe

r o f comment s fromthe general pubh c durin g the publi c commen t period . Followin g ar

e comment s fromth e genera l publi c o n the Propose d Plan . The complet e text o f each publi c commen t i s availabl e i

n th e Administrativ e Record . Each commen t i s followed b y EPA' s response . I n additio n t o the comment s presente d below , EP A receive d 2 1 pos t

card s fromcommunit

y resident s i

n suppor t o f Aheraativ e 7 , th e Lak

e Count y Communit

y Healt h Program . N o pos t

card s were receive d m opposkio n t o th e prefene d altemative . Commen t 1 A s long a s actua

l bloo d lea

d level s are use d a s th e inkia l trigge r fo r furthe r action , I strongly suppor

t thi s proposal . Respons e 1 Bloo d lea d level s i n childre n ar

e not th e only trigger

fo r remedia l actions . Resident s ma

y elec t t o participate h

i th e environmenta

l testmg and remediatio n progra mwithout bloo d lea d testmg or

to participate without

releasin g informatio n o n thef r bloo d lea d levels . Demonstratio n o f

attainment

ofth e perfomianc e standard s fo r 0U 9 will , however , b e base d o n actua l bloo d lead level s mchildre n residin g i n LeadviUe . Th e overa

U effectivenes s ofth e LCCH P will b e demonstrate d throug h attauiment o f perfomianc e standards .Commen

t 2 Institutiona

l control s should , fo

r the mos t part , b e uiclude d a s par

t ofth e Recor

d ofDecisio n regardm g thi s matter

to assure tha

t Lak e Count y an d other

entitie s ar e not burdene d wit

h mappropriat

e long rang e liabilities . Thes e confrol s shoul d b e develope d wit h th e inpu t o f al l uitereste d partie s t

o assure tha t the y ar e reasonabl e an

d scienc e based . Respons e 2 Institutiona

l control s ar

e discusse d furthe

r i n th e Record ofDecisio n (ROD ) and will b e fmalize d durin g the desig n phas e ofth e progra mwit h loca l commimit

y mvolvement . EP

A an d ASARC O ar

e prepare d to wor k cooperativel y wit

h Lak e Count y an d the Cit y o f Leadvill e t

o develo p institutiona

l controls . Discussion s regardin g th e manne r i n whic h th e LCCHP wi

U b e implemente d and additiona l actions , i f any , require d o r

desfred onc e perfonnanc e standard s ar e me t wil l b e integra

l to the developmen

t ofa n appropriate institutiona

l control s progra

ma t thi s site . For

thi s reason , institutiona

l confrol s will b e develope d a s par

t ofth e remedia

l desig n an d presente d mdetai l with mthe Wor

k Pla n fo r th e LCCHP . Commen t 3 The Cit y o f Leadvill e shoul d als o b e mclude d a s a n entit y t o b e consuhe d mthe revie w and approva l proces s (re : change s or

variance s to Standar

d Operatui g Procedure s include d i n the LCCH

P wor k plan) . Respons e 3 W e agre e tha

t th e Cit y o f Leadvill e shoul d b e involve d wk h an y change s mad

e to th e Standar

d Operatmg Procedure s fo

r th e LCCHP . Commen t 4 Institutiona

l control s which mclud

e zonin g change s o r

dee d restriction s ma

y hav e littl e communit

y support . I n addkion , us e oflea d concentratio n contou r map s to delmeat

e area s where mstitutiona

l control s woul d b e unplemente d i s likel y t o b e dispute d b y hom

e owners . Respons e 4 EP A an d Asarc o are prepare d to wor k dfrecti y wit h Lak e Count y an d the Cit y o f Leadvill e to identif

y institutiona

l control s tha

t wil l b e bot

h effectiv e an d unplementable . Severa l divers e groups , whic h include member s fromth e Leadvill e community , cunentl y provid e opportunkie s fo r ckizen s t o take a n activ e rol e mthe consultatio n and decision-makmg proces s fo r th e site . Thes e group s mclud e th e Sit e Activitie s Coordinatui g Committe e an d Kid s Ffrs t Wor k Group . EP A doe s no t

mtend t o identif y area s fo r mstitutiona

l control s base d o

n concentratio n contour

map s previousl y presente d u

i the Feasibility Study . Instead , appropriate mstitutiona l control s will lUcel

y b e tie d t o the statu s o f

remediatio n a

t individua l properties . For

example , i

fenvfronmenta l lea d source s hav e bee n teste d bu t none ofth e trigge

r level s wa s exceeded , then no institutiona

l confrol s woul d b e requfred specifi c t o tha t propert y (such a s land us e restrictio n or dee d notice) . Commen t 5 I t migh t b e reassurin g t

o th e communit

y to exten d bloo d lea

d monitoring beyon d th e children presentl y teste d i n th e voluntat

y program , s o a s t o evaluate th e potentia l effects o f

residential propertie s no t presentl y housin g children . Respons e 5 The LCCH

P wil l b e ope n to al l resident s h i th e sit e regardles s o f

whethe r o r not achil d unde

r 6 year s ol d reside s a t the property . Envfronmenta l testin g a t propertie s bot

h wit h an d without childre n unde

r 6 insure s the protectio n o f

childre n wh o ma

y resid e a t apropert y mthe future . Commen t 6 A samplin g progra

minvolvin g th e testin g o f

domesti c cat s migh

t provide apioneerin g avenu e o f stud y .. . Thi s migh t b e afa r les s expensiv e an d mor

e effectiv e progra

mtha n resuhe d fromth e inconclusiv e effor t mvolvm g swin e testmg . Respons e 6 Severa l lead researcher s hav e suggestmg usm g cat s or dog s a s monitor s oflea d exposure . Unfortunately thef r us e i s stil l quite experimental , and unsuitabl e fo r ou r purposes . For

example , Phili

p Bem y studie d pet s livin g i

n home s o f

childre n i n Granke City , IL . Whil e dog s an d cat s ha d bloo d lea

d level s mor

e or les s U l th e rang e o f

childrens ' levels , there wa s n o reliabl e conelation . If ape t had abloo d lea

d level ove

r 1 0 • g/dl , then there wa s achanc e tha t achil d livin g mth e hous e did , a s well , bu t th e associatio n wa s no t reliabl e enough t o us e th e pet' s measurement instead ofth e children's . Also , i t i s not really imderstoo d wha t lead exposure i s reflecte d madog' s o r cat' s bloo d lea

d level . Dog s kep t

tie d outsid e are no

t expose d to hous e dus t

lUc e childre n are , and cat s kep t uiside are no t

expose d to yar

d soil . Cat s tha

t g o outsid e ma

y roa mawa y fromthe hom

e an d ma y no t represen t exposur e a t the hom e itsel f Finally , pet s will not

b e expose d to dfrect

source s oflea d suc h a s ol d toy s or lead-base d pam

t o n staircase s or

windo w ledge s i

n th e sam e wa y tha t childre n ma

y be . I n conclusion , w e now fee

l tha t althoug h pet s ma

y b e somewha

t usefu l mthe futur

e a s ascreenmg too l mconjunctio n wit h other environmenta

l data , i t will alway s b e mor e effectiv e t o loo

k a t lead i n the envfronmen

t fromth e child' s poin

t o f view . Although th e ffrs

t swme-feedin g tes t

usm g Leadvill e soi l was , inconclusiv e o n it s own , EP A ha s don e man y swin e test s and other

extractio n test s suic e then to stud y bioavailabilit

y o f lea d fromman

y differen t sites , includin g recent

test s usin g soil s fromother ske s mLeadville . EP

A i s hopefu

l tha t th e ne w tes t result s fo r Leadvill e wil l hel

p explai n som

e ofth e unusua

l (highe r o r lower) bloo d lead resuh s i n differen t neighborhood s o f

Leadvill e an

d will contribute t o ou

r understandin g ofth e bioavailabilit y oflea d u

i soil s fromresidential area s o f

Leadville .Commen

t 7 I believ e tha

t peopl e ar e bein g bribe d int

o testm g bloo d lea

d level s [wit

h savmg s bond s and gif

t certificates] . I s thi s typica

l nationwide ? Respons e 7 Ther e ar e other communitie s mth e Unite d States , bot h CERCL A and non-CERCL

A skes , tha

t offe r incentive s to encourag e participatio n i n bloo d lea

d testmg program s an d t o increas e th e accurac y an d effectivenes s o f

thos e monitorin g programs . Th e mcentive s currentl y use d h i LeadviU e appea r to hav e been effectiv e i

n maintainin g ahigh level o f communit y participatio n i

n th e county' s bloo d lea

d monkorin g program . It

i s unportant

to not e tha t th e bloo d lead progra

mi s voluntat

y unde r the CERCL

A action . Bloo d lea

d testin g i s no t

an d wi U no t b e arequfremen

t fo r envfronmenta

l lea d testin g or , i

f necessaty , remediation . Commen t 8 I wis h I coul d believ e tha

t al l ofthi s sit

e wor k i s neede d and tha

t i t doe s pos e a

n imminen t and substantia

l endangermen

t to publi c heahh an

d welfare . I prefe

r Altemativ e 1 : N o Actio n a s th e prefene d altemativ e fo r th e residentia

l area . Respons e 8 EP A agree s tha

t th e risk to th e ckizen s o f

Leadvill e i s moderate a s demonstrate d b y th e on-goin g bloo d lea d progra mbem g conducte d b y Lak

e County . EP

A prefer s th e LCCHP , becaus e i t wil l caus e the leas t amoim t o f disturbanc e to th e communit y whil e bein g protectiv e to cunen t an d futur e resident s a

t the site . I n additio n to writte n comment s receive d durin g the publi c commen t period , EP

A als o receive d som

e verba l coinment s durin g th e publi c meetui g conducte d o n Novembe r 18 , 1998 . FoUowin

g ar e eac h ofth e comment s made durin g th e publi c meetui g followed b y EPA' s response . Commen t 1 Ar e ther e area s mth e Sit

e wher e children' s bloo d lead level s are higher ? D o you se e an y clusterin g o f children wit

h elevate d bloo d lea

d levels ? Respons e 1 Area s ofth e Sit

e where childre n are mor

e likel y t o hav e a

n elevate d bloo d lea

d concentratio n uiclude th e eas t sid e o f Leadvill e nea

r th e histori c minm

g district , Stringtown , and th e Lak e For k trailer par k nea r the confluenc e o f

Californi aGulc h and th e Arkansa s River .Commen

t 2 Wha t ar e the communit

y protectiv e measures , ho w ar e the y bein g developed , an d i s the loca

l communit

y goui g t o hav e mpu

t o n th e communit

y protectiv e measures ? Respons e 2 Ahemativ e 7 , th e Selecte d Remedy , include s the following histitutiona l confrols , t o b e develope d durin g desig n ofth e remedy , t o ensur e effectivenes s ofth e Lak

e Count y Communit

y Healt h Progra m(LCCHP) . ASARC O and Lak

e Count y will b e responsibl e fo

r implementm

g and mamtaining thes e mstimtiona l controls . 1 . The creatio n ofa n overla y distric t t o provid e notificatio n and mformatio n regardin g th e LCCHP , includin g requfrement s tha t specif y excavatio n activitie s or

other use s woul d resul t i n refena l ofth e propert

y owne r t o th e LCCHP . 2 . A dat amanagemen t and trackin g syste msuc h a s acompute r database , t

o maintain sampling , respons e actio n an d other information relate d to uidividua l lot s r o propertie s withi n 0U9 . Thi s mformation woul d b e availabl e t o uitereste d partie s subjec t t o notificatio n through th e overla y district . Th e dat amanagemen t systemwil

l b e accessibl e b y a U partie s o f

the LCCHP wor

k group . Commen t 3 The Count y i s oppose d to usm

g th e 0- 6 inch lea

d msoil s distributio n ma

p a s shown mthe Feasibilit y Stud y (Figur e 2-2) . Thi s ma

p wa s develope d usin g sample s fromstreet s an d alley way s instead o f

actual yards . Respons e 3 An y soi l respons e action s will b e base d o n property-specifi c data , no t th e lea d i n soil s distributio n ma

p presente d mth e FeasibiUt

y Study . Commen t 4 Ho w will histitutiona

l confrol s b e unplemente d a s avoluntat y program ? Respons e 4 EP A and ASARC O are prepare d to wor k dfrecti y wit h Lak e Count y and the Cit

y o f Leadvill e t

o identif y institutiona

l control s tha

t will b e bot

h effectiv e an d implementable . Severa l divers e groups , whic h mclud e member s fromthe Leadvill e community , cunentl y provid e opportunitie s fo r ckizen s t o take a n activ e rol e U l the consultatio n and decision-makin g proces s fo r th e site . Thes e group s includ e the Sk e Activitie s Coordinatui g Committe e and Kid s Firs t Wor k Group . Appropriat

e institutiona

l control s will likely b e tie d to the statu s o f

remediatio n a

t mdividua l properties .Commen

t 5 Th e Coimt y i s oppose d to mstitutiona l controls . Wh

y are they Uste

d i n th e feasibilit

y study ? Respons e 5 Institutiona

l control s ar

e liste d i n the Feasibilit

y Stud y t o mvestigat

e thes e option s further . EP A understand s tha

t th e Count y support s implementatio n o f institutiona

l confrol s a s describe d i

n the ROD . Commen t 6 Ho w ma y propertie s wil l nee d soi l remediation ? Respons e 6 Th e estimate i s 15 0 homes . Commen t 7 I a moppose d to sweepin g zonui g restrictions . Ho w will vacan

t lot s and ne w development b e addressed ? Respons e 7 The selecte d remed

y wil l no t mfluenc e zoning . I

n the even t tha t development

disturb s contaniinate d soils , appropriate measure s to manag e the soil s woul d hav e t o b e taken . Appropriate measure s woul d depen d o n eventua

l land use . Commen t 8 Ho w were trigge

r level s established ? Respons e 8 Ris k assessment s wer

e relie d upo n to establis h trigge r levels . Commen t 9 I n the feasibiht

y stud y k say s tha t the progra

mwill las t fo r 1 2 years . Afte

r tha t time , doe s the Count

y hav e to bar e th e cost ? Respons e 9 ASARC O i s responsibl e fo r implementing th e LCCH

P unt U perfonnanc e standard s hav e bee n met .Commen

t 1 0 Onc e th e bloo d lea

d level s goal s ar

e met , ho w man

y year s doe s th e progra

mhav e to contmue ? Respons e 1 0 Th e Progra

mwil l continu e unti l performanc e standard s hav e been met . EP A will conduc t

five yea r review s ofth e Sit

e t o ensur e tha t the remed

y remain s protective . Commen t 1 1 Wha t happen s 1 0 year s dow n the roa d whe n th e progra mlose s momentum , how will th e remediatio n b e ensured ? Respons e 1 1 Incentive s wil l b e offere

d t o ensur e adequate participatio n i

n the program . EP

A will conduc t

five yea r review s t o ensur e tha t the remed y remain s protective . Commen t 1 2 Coul d th e Sit

e b e deliste d even i

f al l propertie s d o no t

hav e sampling/remediatio n conducted ? Respons e 1 2 Onc e performanc e standard s hav e bee n met , EP A will procee d wit

h deUstmg . Commen t 1 3 How lon g unti l th e LCCH

P ca n b e implemented ? Respons e 1 3 W e anticipate tha

t the progra

mwill begi n i

n 1999 . Commen t 1 4 If apropert y owner refuse s to participate , wil l fence s b e put around the property ? Respons e 1 4 No .

### Appendi x C APPLICABL E O R RELEVAN T & APPROPRIAT E REQUIREIMENT SSUMMAR Y O F POTENTU L ARAR S Residentia l Populate d Area (Operabl e Uni tNo . 9 ) Standard , Requirement , Criteria , o r Limitatio n Citatio n Potentiall y Applicabl e Potentiall y

Relevan tan d Appropriat e Descriptio n Comment s SIIMMAR

Y O F POTENTIA L CHEMICAL-SPECIFI C ARARs/TBC s 1 . Clean Air

Act , Nationa l Primar y and Secondar y Ambient

Air Qualit y Standard s

2 . Colorad o Ambient Ai r Qualit y Standard s

3 . Colorad o Ai r

Pollutio n Preventio n an d Contro l Act , Regulatio n 8 4 2 US C Sect . 7401

- 7642 , 4 0 CF

R Par t 5 0

5 CC R 100 1

5 CC R 1001-14 ; 5 CC R 1001-1 0 Par

t C (1) , Regulatio n 8 Ye s

Ye s

Ye s National ambient air qualit y standard s (NAAQS ) ar e implemente d throug h th e Ne w Sourc e Revie w Progra man d Stat e Implementatio n Plan s (SIPs) . Th e federa

l Ne w Sourc e Revie w Progra m addresse s only major

sources . Se e Colorad o Ai r Pollutio n Preventio n an d Contro l Ac t concemin g applicability o f

requirement s implemente d throug h th e SIP .
F*rimar y an d secondary standard s fo r P M 1 0 i n ambient air . Federal an d Stat e TS P standard s hav e bee n replace d wit

h P M 1 0 an d PM2. 5 standards .

Regulatio n No . 8 set s emissio n limit s fo r lead . Applicant s ar e require d t o evaluat e whethe r th e propose d activitie s woul d resul t i n a n exceedanc e ofthi s standard . Emission s associate d wit h propose d remedial actio n a t individual propertie s wil l b e limite d t o fugitiv e dus t

emission s associate d wit h eart h movin g activitie s durin g soi l removals . Thes e activitie s wil l no t

constitut e amajor source . Federal NAAQ S more stringen t tha n Stat e standard s ma

y b e applicable . Complianc e wit

h thes e standard s wil l b e addresse d i

n th e Fugitiv e Emission s Dus t Contro l Plan . (Se e #10 ) | Complianc e wit

h ambien t ai r standard s wil l b e achieve d b y adherin g to aFugitiv e Emission s Dus t

Contro l Pla

n prepare d in accordanc e wit

h Regulatio n No . 1 (se e #10) . Thi s plan wil l discus s monitorin g requirements , i f

any , necessar y t o achiev e thes e standards . Fugitiv e dus t

emission s ar e expecte d t o b e o f limite d nature , occu r

i n isolate d area s an d fo

r shor t period s oftime . Lea d emission s ma y occu r bu t ar e no t expecte d t o excee d th e emissio n level s fo

r lead . Complianc e wit

h Regulatio n No . 8 wil l b e achieve d b y adherin g t o afugitiv e emission s dus t contro l plan prepare d in accordanc e wit h Regulatio n No . 1 (se e #10) . Thi s pla

n wil l discus s monitorin g requirements , i f any , necessary t o achiev e thes e standard s

F:\MyFiles\Documems\WP\Cgou9\ARARS.wp d Pag e 1 o f 5 Septembe r 2 , 199 9SUMMAR Y O F POTENTIA L ARAR S (Continued ) Standar d Requirement , Criteria , o r Limitatio n Citatio n Potentiall y Applicabl e Potentiall y

Relevan tan d Appropriat e Descriptio n Comment s SUMMAR Y O F POTENTIA L LOCATION-SPECIFI C ARAR s | 4 . Resourc e 1 Conservatio n an d Recover y Ac t (RCRA) , Subtitl e D

5 . Executiv e Orde r 1159 3 - Protectio n and Enhancemen t

o f th e Cultural Environment 6 . Nationa

l Histori c Preservatio n Ac t (NHPA )

7 . Th e Histori c an d Archaeologica

l Data 1 Preservatio n Ac t

o f 1974 4 0 CF R Par t 258.10-1 5

1 6 US C 47 0

16USC§470e t seq. ; 4 0 CF

R § 6.301(b) ; 3 6 CF

R Par t 63 , Par t 65 , Par t 80 0

1 6 US C 46 9 4 0 CF R § 6.301(c ) N o

Ye s

Ye s

Ye s Ye s Facilitie s wher e treatment , storag e o r disposa l o f soli d wast e wil l b e conducte d mus t mee t certai n locatio n standards . Thes e includ e locatio n restriction s o n proximit

y to airports , floodplains , wetlands , fault

areas , seismi c impac t

zones , an d unstabl e areas . Federa l agencie s directe d t o institut e procedure s t o ensur e program s contribut e t o th e preservatio n an d enhancemen t

o f non-federall y owne d histori c resources . Consultatio n wit h th e Advisor

y Counci l o n Histori c Preservatio n required . Expand s histori c preservatio n program s t o minimiz e har

mt o National Histori c Landmarks ; require s preservatio n o f

resource s include d i

n o r eligibl e fo r listin g o n th e National Registe r fo r Histori c Place s (NRHP) . Establishe s procedure s t o preserv e historica l an d archeologica l dat atha

t migh t b e destroye d throug h alteratio n o f

terrai n a s aresul t

o f a federa l constructio n projec t

o r afederall y license d activit

y program . Ma y b e relevan t

an d appropriat e i f

interi m disposa l i s conducte d o r

i f a n onsit e repository i s necessary .

Se e # 6 below .

Thi s Ac t i s applicabl e withi n th e Leadvill e National Histori c Landmar k District . A Programmati c Agreemen t exist s betwee n th e EPA , th e Advisor

y Counci l o n Histori c Preservation , an d th e Colorad o Stat e Histori c Preservatio n Office

r in accordanc e wit

h Sectio n 10 6 an d 110(f

) o f NHPA . Remedial Activitie s ma

y affec t historica l and/o r archeological data . A cultural resource s surve y wil l b e performe d t o identif y an d evaluat e al l histori c propertie s whic h ma y b e affecte d by remedial activities . | |

F:\MyFiles\Dociiniems\WP\Cgou9\ARARS.wp d Pag e 2 o f 5 Septembe r 2 , 199 9SUMMAR Y O F POTENTIA L ARAR S (Continued ) Standard , Requirement , Criteria , o r Limitatio n 8 . Colorad o Historical , Prehistorical , an d Archaeological Resource s Ac t

9 . Colorad o Registe r

o f Histori c Place s Citatio n Colorad o Revise d Statute s (CRS ) § § 24-80-40 1 t o 411 , 24-80-130 1 to 130

5

CR S §§24-80-10 1 t o 10 8 Potentiall y Applicabl e N o

Unknow n Potentiall y

Relevan tan d Appropriat e Unknow n

— Descriptio n

Establishe s procedure s an d require s apermi t fo r investigation , excavation , gathering , o r removal fro

mth e natiu-a

l stat e ofan y historical , prehistorical , o r archaeologica l resource s on stat e land s fo r th e benefi t

o f recognize d scientifi c o r

educationa l institutions . Als o require s a n excavatio n permi t an d notificatio n i f

huma n remain s ar e found on stat e land . Establishe s requirement s fo r protectin g propertie s o f

historica l significance . Comment s May b e relevan t

an d appropriat e i f archaeologica l resource s ar e remove d o r huma n remain s discovere d durin g remedia l activities ; coordinatio n wit h stat e archaeologis t

required , bu

t n o permi t

i s neede d withi n th e Superfun d site .

Ma y b e applicabl e i f

remedial acfion s impac t an y property liste d on th e Registe r o f Histori c Places . SUMMAR

Y O F POTENTIA L ACTION-SPECIFI C ARARs/TBC s 10 . Colorad o Air Pollutio n Preventio n an d Contro l Act , Fugitiv e Dus t Contro l Plan/Opacity , Regulatio n No . 1 11 . Colorad o Ai r Pollutio n Preventio n an d Contro l Act , APEN s Regulatio n No . 3

12 . Colorad o Ai

r Pollutio n Preventio n and Contro l Act , Odors , Regulatio n No . 2 5 CC R 1001-3 ; § in . D . l.b,c,d . § lII.D.2.a,b,c,e,f, g Regulatio n 1 5 CC R 1001-5 , Regulatio n 3

5 CC R 1001- 4 ye s

Ye s

Ye s — Regulatio n No . 1 provision s concemin g fugitiv e emission s fo

r constmctio n activities , storag e an d stockpilin g activities , hau l roads , hau l tmcks , an d tailin g ponds .
Establishe s emission s contro l regulation s fo r constmctio n o r

modificatio n o f

stationar y sources .
Applie s t o any remedial actio n tha t ma y creat e regulate d odors . Onl y provision s unde r Regulatio n 1 concemin g fijgitive emission s fo r constmctio n activities , includin g soi l renioval , storage , transport an d stockpilin g ( 5 CC R 1001-3 ; Section s III.D.2.b,c,e,f,g.) , ar e applicable . Substantiv e requirement s ofa n Air Pollutio n Emissio n Notic e (APEN ) ar e applicabl e i f th e removal action s distur b contaminate d soil . A n APE N wil l b e filed , althoug h pemiittin g requirement s suc h a s thi s a mno t typicall y require d under

CERCLA . Planne d remedia l action s ar e no t expecte d t o creat e regulate d odors .

F:\MyFiIes\Documents\WP\Cgou9\ARARS.wp d Pag e 3 o f 5 Septembe r 2 , 199 9SUMMAR Y O F POTENTIA L ARAR S (Continued ) 

### l l Standard , Requirement , Criteria , o r Limitatio n 13 . Colorad o Ai

r Pollutio n Preventio n an d Contro l Act , Requirement s fo

r Lead

Base d Paint

Abatemen t Regulatio n No . 1 9 14 . Soli d Wast e Disposa l Ac t (SWDA ) a s amende d b y RCRA , Criteri afo

r Classificatio n o f

Soli d Wast e Disposa l Facilitie s an d Practice s (Subtitl e D ) 15 . SWD A a s amende d b y RCR A Subtitl e C 16 . Hazardou s Material s Transportatio n Act , Regulation s

17 . Colorad o Nois e Abatemen t

Ac t 18 . Colorad o Wate

r Qualit y Contro l Ac t Stormwate r

Discharg e 1 Regulation s Citatio n Colorad o Revise d Statute s § § 25-7

- 1101-1107 , Regulatio n 1 9

4 2 US C Sect . 6901

- 6987 , 4 0 CF R Par t 25 7

4 2 US C Sect . 690 1 - 6987 , 4 0 CF R Par t 26 4 4 9 US C Sect . 180 1 - 1813, . 4 9 CF R Part s 107 , 171017 7

CR S § § 25-12-10 1 to 10 8 5 CC R 1002. 2 Potentiall y Applicabl e Ye s

Ye s

Ye s
Unknow n

Ye s

Ye s Potentiall y

Relevan tan d Appropriat e

—

—

— Descriptio n

Establishe s procedure s an d requirement s fo r lead-base d pain t

abatement s greate r

than 2 squar e interio r

feet an d 1 0 squar e exterio r feet , includin g trainin g an d accreditatio n o f individual s and firm s engage d i n lead

- base d pain t activitie s an d wor

k practic e standard s fo r performin g suc h activities . Establishe s criteri afo

r us e i n determinin g whic h soli d wav e disposa l facilitie s an d practice s pos e areasonabl e probability o f advers e effect s on health . Regulate s handling , transportation , storag e an d disposa l o f

hazardou s wastes . Regulate s transportatio n ofhazardou s materials .

Establishe s maximu mpermissibl e nois e level s fo r particula r time period s an d lan d us e zones . Establishe s stormwate r

contro l requirement s fo r constmctio n activities . Comment s Applicabl e whe n lead-base d pain t abatemen t activitie s ar e performed . On-sit e CERCL A action s ar e exemp t

fro madministrativ e an d fe e requirements . Subjec t t o project-specifi c varianc e pe r

Section s IV. G an d V. M o f Regulatio n 19 . Substantiv e requirement s ma y b e applicabl e o r relevan t an d appropriat e to th e consolidatio n o f

soi l remove d fro

m

Potentiall y applicabl e fo

r lead-base d paint wast e debri s resultin g fro mremediation . Applicabl e onl y i f

th e remedial actio n involve s off-sit

e transportatio n ofhazardou s materials . Th e regulation s affectin g packaging , labeling , making , placarding , usin g prope r

containers , an d reportin g discharge s o f

hazardou s material s woul d b e potentia l ARARs . Applicabl e i f

constmctio n activitie s occu r i n residentia l areas . Potentiall y applicabl e i f

constmctio n activitie s occu r

a s part ofth e remedial action .

F:\MyFUes\Documents\WP\Cgou9\ARARS.wp d Pag e 4 o f 5 Septembe r 2 , 199 9Standard ,

Requirement , Criteria , o r Limitatio n 19 . Colorad o Soli d Wast e Disposa l Site s an d Facilitie s Ac t 20 . Colorad o Hazardou s Waste Regulation s

21 . Colorad o Mine d Land Reclamatio n Ac t

22 . Colorad o Primar

y Drinkin g Water Regulatio n Citatio n 6 CC R 1007- 2

6 CC R 1007-3 , Par

t 264 : Sectio n 264.301 , (g),(h) , (i ) an d (j) ; Sectio n 264.310(a)(1 ) throug h (a)(4) ; Sectio n 264.310 , (b)(1 ) an d (b)(5 )

CR S 34-32-10 1 t o 125 ; Rul e 3 o f Mineral Rule s an d Regulation s

5 CC R 1002 , CR S 25-1-107 , Sectio n 7.3. 2 Potentiall y

Applicabl e Ye s

N o

N o

N o Potentiall y

Relevan tan d Appropriat e

—

Ye s

Ye s

Ye s Descriptio n

Establishe s standard s fo

r licensing , locating , constructin g an d operatin g soli d wast e facilities . Specifi c provision s ofSectio n 264.30 1 conce mmn-o n control , run-of f control , management

o f mn-o n an d mn-of

f contro l system s an d win d dispersal . Specifi c provision s ofSectio n 264.31 0 conce m placemen t o f acove r to minimiz e infiltration , minimiz e maintenance , promot e drainag e an d minimiz e erosio n an d accommodat e settling .

Regulate s al l aspects o f

lan d us e fo

r mining , includin g th e locatio n o f

minin g operation s an d relate d reclamatio n activitie s an d othe r environmental an d socio-economi c impacts .

Requirement s to contro l lea d an d coppe r concentration s in tap water . Comments Substantiv e requirement s ma y b e applicabl e o r relevan t an d appropriat e t o th e consolidatio n o f

soi l remove d fro

m residentia l area s i

n an on-sit e repository . Thes e specifi c provision s o f th e hazardou s wast e regulation s ma

y b e relevan t

an d appropriat e i

n certai n circumstance s dependin g o n sit e specifi c conditions . Th e determinatio n o f

whethe r suc h requirement s wil l b e bot

h relevan t an d appropriat e t o th e activitie s t o b e undertake n i n OU 9 wil l b e base d on bes t

professiona l judgemen t

an d i s conducte d o n asit e specifi c basi s takin g int o accoun t th e physical nature an d locatio n o f th e medi ainvolved , whethe r th e requirement s ar e wel l suite d t o th e sit e conditions , an d othe r

factors . N o minin g o r

reclamatio n activitie s ar e planne d a s par

t o f remedy . I f

minin g activitie s ar e performed , the n substantiv e requirement s o f

selecte d portion s o f

Rul e 3 regardin g Reclamatio n Measures , Water-Genera l Requirement s (excep t portion s relatin g t o sitewid e surfac e an d groundwater) , wildlif

e an d revegetatio n ma

y b e applicable . However , certai n provision s o f thes e regulation s ma

y b e relevan t

an d appropriat e t o th e 0U 9 remedial action . Ta p wate r samplin g requirement s ar e relevan t an d appropriate .

F:\MyFiles\Docu(nents\WP\Cgou9\ARARS.wp d Pag e 5 o f 5 Septembe r 2 , 199 9