# c L 30537 2 

## AfflfilNlSIRATI V RECOR D 

# FIL E PLA N



# u L FEASIBILIT Y STUD Y WOR K PLA N F O R STOCKPILE D FIN E SLA G A T TH E CALIFORNI A GULC H SUPERFUN D SIT E LEADVILL E COLORAD O 

# L L FINA L DRAF T
Marc h 15,199 4 

### Prepare d fo r Denve r an d Ri o Grand e Wester n Railroa d Prepare d b y Morriso n Knudse n Environmenta l Service s 

# L Submitte d b y Denve r an d Ri o Grand e Wester n Railroa d Pursuan t t o th e Consen t Decre e 

# L

## L 

# L FEASIBILIT

Y STUD Y WOR K PLA N FO R STOCKPILE D FIN E SLA G A T TH E CALIFORNI A GULC H SUPERFUN D SITE
, LEADVILLE COLORAD O TABL E O F CONTENT S Sectio n Titl e Pag e 1. 0 INTRODUCTIO

N

......................................... . 1 1. 1 Objectiv e o f th e Feasibilit y Stud y .......................... .

1 1 2 Organizatio n o f th e Projec t Tea m .......................... .

3 13 Organizatio n o f th e Wor k Pla n ............................ .

3 Y 2. 0 SIT E BACKGROUN D AN D DESCRIPTIO

N

..................... .

5 2. 1 Genera l Sit e Descriptio n ................................ .

5 2.1. 1 Climatolog y ................................... . 5 2.1 2 Geology......................................

. 6 2.1 3 Groun d Wate r ................................. . 7 2.1. 4 Surfac e Wate r ................................. . 7 2.1. 5 Soil s
........................................ . 8 2. 2 Definitio n o f Lea d Sla g ................................. .

8 2 3 Sla g Pil e Description s
................................... . 9 23. 1 Th e Arkansa s Valle y Sla g Pil e ..................... .

9 23. 2 Th e L a Plat a Sla g Pil e .......................... .

1 0 23. 3 Th e Harriso n Stree t Sla g Pil e .................... .

1 1 23. 4 Othe r Sla g Pile s
............................... .

1 2 3. 0 SUMMAR Y

O F SLA G INVESTIGATION

S

..................... .

1 3 3. 1 Stat e o f Colorad o R I 198 6

.............................. .

1 3 3 2 EP A Phase I I R I 198 9

................................. . 1 3 3 3 Jame s P

. Wals h an d Associates
, Inc

. Soil s Investigatio n 198 8

..... . 1 4 3. 4 Jacob s Engineerin g Sla g Samplin g 198 9

.................... .

1 5 3. 5 Summar y o f D&RG W Sla g Pil e Remedia l Investigatio n Activitie s
........................................... . 1 6 3.5. 1 Historica l an d Ownershi p Researc h

................ .

1 7 3.5. 2 Fiel d Wor k

.................................. . 1 7 3.5 3 Laborator y Analyse s
........................... .

1 8 3.5. 4 Sla g Pil e Conceptua l Mode l

...................... .

1 9 3. 6 Conclusion s fro m al l o f th e Sla g Investigations
............... .

2 0 4. 0 SUMMAR Y

O F RESULT S O F TH E SCREENIN G FEASIBILIT

Y STUD Y

................................................ . 2 1 4. 1 Identificatio n o f Remedia l Actio n Objective s
................ .

2 1 42 Identificatio n an d Screenin g o f Technologie s Type s
............ .

2 2 4.2. 1 Potentiall y Applicabl e Technologie s an d Proces s Option s fo r Sla g Pile s
.......................... .

2 2 4.2. 2 Screenin g Criteri a ............................. .

2 2 

# L MORRISO N

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# L b

j bb\1S83\FSWP.FN

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3 Screenin g o f Potentiall y Applicabl e Remedia l Technolog y Proces s Option s fo r Sla g Pile s
........... . 2 3 43 Developmen t an d Analysi s o f Remedia l Actio n Alternative s
..... . 2 4 1 , 4. 4

ARAR s Analysi s
..................................... . 2 5 5. 0 FINA

L FEASIBILIT

Y STUD Y

............................... .

2 6 5. 1 Detaile d Analysi s o f Alternative s
......................... .

2 6 5 2 Alternative s Evaluatio n Criteri a .......................... .

2 7 I 52. 1

Overal l Protectio n o f Huma n Healt h an d th e i Environmen t

................................. . 2 7 52 2 Complianc e wit h ARAR s
........................ .

2 7 52 3 Long-Ter m Effectivenes s an d Permanenc e ........... . 2 8 ^ 52. 4

Reductio n o f Toxicity
, Mobilit y o r Volum e ........... . 2 9 52. 5 Short-Ter m Effectivenes s
........................ .

2 9 ; > 52. 6

Implementabilit

y .............................. .

3 0 L 5.2. 7

Cos t

....................................... . 3 0 52. 8 Stat e Acceptanc e ............................... .

3 0 52. 9 Communit y Acceptanc e ......................... .

3 1 5 3 Presentatio n o f Individua l Alternative s
..................... .

3 1 5. 4 Comparativ e Analysi s o f Alternative s
...................... .

3 1 5. 5 Presentatio n o f Comparativ e Analysi s
...................... .

3 1 5. 6 Cultura l Resource s Surve y an d Evaluatio n .................. .

3 1 6. 0 SCHEDUL E

............................................. . 3 2 7. 0 REFERENCE

S

........................................... . 3 3 t , U Table s

^ * Tabl e 4- 1 Evaluatio n o f Proces s Option s fo r Sla g Pile s Tabl e 4- 2 Screenin g o f Remedia l Alternative s Figure s

« | Figur e 1. 1 Projec t Organizatio n Char t Figur e 2. 1 Sit e Ma p 

# i 

# L

l <

MORRISO N

KNUDSE N CORPORATIO N bb\1893\FSWP.FN L U (03/25/84 ]

## I f 

### v V

f : 

# i 

# w 

# I ACRONY

M AO C ARA R A V AWQ C C D CD H CERCL A C F S CL P C W A D&RG W EP A F S G G H R L E L P M E M K M S L N C P O& M PR P RA O R I RO D SAC C SAR A S F S SPL P T A G T A L U E LIS

T O F ACRONYM S EXPLANATIO N Administrativ e Orde r o n Consen t Applicabl e o r relevan t an d Appropriat e regulation s Arkansa s Valley (Smelte r o r Sla g pile ) Ambien t Wate r Qualit y Criteri a Consen t Decre e Colorad o Departmen t o f Healt h Colorad o Department o f La w Comprehensiv e Environmenta l Response
, Compensatio n an d liabilit y Ac t Cubi c Fee t pe r Secon d Contrac t Laborator y Progra m Clea n Wate r Ac t Denve r an d Ri o Grand e Wester n Railroad Environmenta l Protectio n Agenc y Feasibilit y Stud y Georgi a Gulc h Sla g Pil e Harriso n Stree t Sla g Pil e Lowe r Evan s Sla g Pil e L a Plat a (Smelte r o r Sla g Pile ) Middl e Evan s Sla g Pil e Moniso n Knudse n Environmenta l Service s Mea n Se a Leve l Nationa l Contingenc y Plan Operation s an d Maintenanc e Potentiall y Responsibl e Part y Remedia l Actio n Objectiv e Remedia l Investigatio n Recor d o f Decisio n Sit e Activitie s Coordinatin g Committe e Superfun d Amendment and Reauthorizatio n Act Screenin g Feasibilit y Stud y Syntheti c Precipitatio n Leachin g Procedur e Technica l Assistanc e Committe e Targe t Analyt e Lis t Uppe r Evan s Sla g Pil e

MORRISO N KNUDSE N CORPORATIO N bb\1883\FSWP.FN L 11 1 P3/2S/M Jf V 

### L 1. 0 INTRODUCTIO

N

: Thi s Feasibilit y Stud y Wor k Plan
, submitte d b y D&RG W pursuan t t o D&RGW s Consen t
^ Decre e (EPA
, 1993a ) entere d b y th e Cour t o n Decembe r 15,1993 , addresse s th e stockpile d { sla g fine s at severa l sla g pile s (Arkansa s Valley
, L a Plata
, Harriso n Street
, Georgi a Gulch
, *• " Uppe r Evans
, Middl e Evan s an d Lowe r Evan s sla g piles ) withi n th e Californi a Gulc h

t Superfun d

Sit e i n Leadville
, Colorado

. A Remedia l Investigatio n (RI ) wa s performe d fo r i « th e lea d sla g pile s b y D&RG W i n 199 2 (M K 1992)

. Subsequen t t o th e RI
, a Site-wid e Screenin g Feasibilit y Stud y (SFS)
, (EPA
, 1993b)
, wa s undertake n a s a join t effor t betwee n ^ th e PRP s an d th e EPA
, an d finalize d i n Septembe r o f 1993

. Th e purpos e o f th e SF S

wa s to : t 1

.

Develo p an d evaluat e alternative s fo r remedia l actio n t o prevent , mitigat e o r ] otherwis e

respond t o o r remed y th e releas e o r threatene d releas e o f V hazardou

s substance s fro m th e site

. i V * 2

.

Conside r th e rang e o f alternatives describe d i n CERCLA
, SAR A an d th e NCP

. I *- » 3

.

Evaluat e remedia l alternatives wit h specia l consideration s give n t o v technologies

tha t permanentl y contain , immobilize , o r recycl e contaminant s t o th e maximu m exten t possible

. i * * Th e SF S evaluatio n considere d effectiveness
, implementabilit y an d relativ e cos t o f eac h f alternative

.

A s a resul t o f th e SFS
, thre e alternative s fo r sla g wer e retained

. This wor k pla n ^
~ build s o n th e SF S an d describe s th e methodologie s an d procedure s t o b e use d i n th e 

### I detaile d analysi s o f alternative s fo r th e stockpile d fines

. 1. 1 Objectiv e o f th e Feasibilit y Stud y j

_ Th e feasibilit y stud y proces s ma y b e viewe d a s occurrin g i n three distinc t phases : ! , 1

. Developmen t o f Alternative s 2

. Screenin g o f Alternative s I 3

.

Detaile d Analysi s o f Alternative s

MORRISO N KNUDSE N CORPORATIO N
t bb\1883\FSWP.FN

L 1 [03/25/M ]i , 

### L
,

^ Th e SF S complete d th e firs t tw o phases

. I n th e Feasibilit y Study
, th e Detaile d Analysi s o f 

### Alternative s wil l b e conducte d o n th e retaine d alternative s whic h are : i ^ 1

.

N o Actio n j 2

.

Institutiona l Control s * * 3

. Resourc e Utilizatio n

v Th e developmen t an d screenin g o f alternative s consis t o f si x steps , whic h include : \ * I 1

.

Developmen t o f remedial actio n objectives

. 2

. Developmen t o f genera l respons e actions

. | 3

.

Identificatio n o f volume s o r area s o f medi a t o whic h th e genera l respons e *" * action

s ma y b e applied

. <' 4

.

Identificatio n an d screenin g o f technologies applicabl e t o eac h genera l V respons e

action

. 5

. Identificatio n an d evaluatio n o f technolog y proces s option s t o selec t a U representativ e

proces s fo r eac h retaine d technolog y type

. 6

. Assemblag e o f th e selecte d representativ e technologie s int o alternatives

. 

### i' V I n th e cas e o f th e SF S work , th e screenin g o f alternative s wa s conducte d usin g th e criteri a j o f effectiveness
, implementabilit y an d cost

. Th e retaine d alternative s wil l b e evaluate d *" " durin g th e Detaile d Analysi s o f Alternatives
, whic h i s th e subjec t o f th e Feasibilit y Stud y )' outline d i n thi s Wor k Plan

. Durin g th e Detaile d Analysi s o f Alternatives
, nin e evaluatio n ^ criteri a wil l b e used : i V •

Overal l protectio n o f huma n healt h an d th e environmen t

, •

Complianc e wit h ARAR s ^ •

Lon g ter m effectivenes s an d permanenc e • Reductio n o f toxicity , mobilit y o r volum e j j " • Short-ter m effectivenes s • Implementabilit

y
• Stat e Acceptanc e j •

Communit y Acceptanc e 

# L MORRISO

N KNUDSE N CORPORATIO N bb\1t83\FSWPJN L [03/25/04 ]

### ^ Thes e analyse s wil l allo w compariso n o f th e retaine d alternatives , an d wil l lea d t o selectio n b y th e EP A o f th e preferre d alternative

. Th e preferre d alternativ e fo r stockpile d sla g fine s

. i n D&RGW s wor k are a wil l b e include d i n th e propose d pla n an d recor d o f decision

. *& i 1. 2 Organizatio n o f th e Projec t Tea m *• * Figur e 1. 1 o f thi s pla n depict s th e projec t organizatio n an d personne l assignment s fo r th e 

### Feasibilit y Stud y fo r stockpile d lea d sla g fine s a t th e Californi a Gulc h Superfun d site

. Th e i^ , responsibilitie s

o f th e Projec t Manage r positio n ar e describe d i n th e followin g section

. Becaus e o f th e natur e o f th e wor k i n thi s FS
, th e projec t Manager i s th e onl y perso n o n th e t projec t tea m whic h i s described

. Technica l specialist s ma y b e aske d b y th e projec t manage r t o provid e specialize d service s fo r th e F S o n a n a s needed basis , bu t thei r rol e i s no t \ expecte d

t o b e signfican t enoug h t o warran t inclusio n i n th e organizatio n char t o r "" " explanatio n

o f duties

. i t ' * r Projec t Manage r 

### Morriso n Knudsen' s Projec t Manager wil l b e th e prim e poin t o f contac t wit h EP A an d L D&RG W durin g th e Feasibilit y Stud y an d wil l hav e overal l managemen t responsibilitie s fo r technica l an d schedulin g matters

. Othe r responsibilities , a s necessary , wil l include :

r- *- » 

### • Procuremen t an d supervisio n o f an y subcontracto r services

. 5 1 i 

### *

~ • Assignmen t o f duties t o th e projec t staf f an d orientation o f th e staf f t o th e • need

s an d requirement s o f th e project

. * • •

Coordinatio n o f th e effort s o f th e in-hous e technica l revie w committee

. • Revie w an d approva l o f an y project-specifi c procedure s an d internall y prepare d plans , drawings , specifications
, cos t estimate s an d reports

. i •

Disseminatio n

o f project-relate d informatio n fro m EPA
, D&RG W an d other s 

### t o th e projec t staff

. 1 * " •

Liaison betwee n th e projec t technica l staf f an d othe r interna l disciplines , suc h
: a

s qualit y assuranc e an d healt h an d safety

.

MORRISO N KNUDSE N CORPORATIO N bb\1BS3\FSWPJN L O (03/25/84 ]^ •

Attendanc e a t meeting s an d conference s betwee n MK
, D&RGW
, CDH
, EPA
, citizen s groups , th e Technica l Advisor y Committee
, an d th e Sit e Activitie s 1 Coordinatin

g Committe e (SACC)

.
; •

Communit y Relation s activities

. w • An y o f thes e responsibilitie s ma y b e delegate d t o member s o f th e projec t staff

. ! t i f r 1 3 Organizatio n o f th e Wor k Pla n i i Thi s Wor k Pla n i s organize d int o th e followin g sections : Sectio n 2.0 , Sit e Backgroun d an d Description ; Sectio n 3.0 , Summar y o f Previou s Sla g Investigations ; Sectio n 4.0 , Summar y o f j Result s o f th e Screenin g Feasibilit y Study ; Sectio n 5.0 , Fina l Feasibilit y Study ; Sectio n 6.0 , Schedule ; an d Sectio n 7.0 , References

. i i 

# I I

L I



# w
MORRiSO

N KNUDSE N CORPORATIO N bb\1883\FSWPJN L 4 (03/2S/W J

### 2 . 0 SIT E BACKGROUN D AN D DESCRIPTIO N Th e followin g descriptio n o f th e Californi a Gulc h Sit e include s a brie f histor y o f th e Leadvill e minin g district , a genera l descriptio n o f th e physiographi c an d hydrologi c propertie s o f th e Site
, an d summar y description s o f th e majo r sla g piles

. f 2. 1 Genera l Sit e Descriptio n ( ^ Th e Californi a Gulc h CERCL A Sit e ha s see n ove r 13 0 year s o f minin g an d minera l processin g activity

. I t encompasse s th e tow n o f Leadville
, Colorad o an d surroundin g areas , ! whic h ar e approximatel y 10 0 mile s southwes t o f Denve r a t a n elevatio n o f approximatel y 10,00 0 fee t abov e mea n se a leve l (MSL)

. Silver
, gold , copper , lead , an d zin c wer e mine d j b y underground an d place r method s fro m th e majo r sulfide/carbonat e or e deposi t i n th e area . Approximatel y 1 7 smelte r facilitie s ar e reporte d t o hav e operate d there

. Onl y a fe w ; ; smal l t o moderate-siz e minin g operation s no w exis t an d n o smelter s currentl y operat e i n * * Leadville

. f w Th e mai n mining-relate d feature s i n th e Leadvill e are a toda y includ e th e following : j ^ •

Tailing s impoundment s • Sla g pile s t •

Mor e tha n tw o thousan d wast e roc k dumps • Abandone d mining , milling , and smeltin g facilitie s )

. • A fe w activ e minin g an d reprocessin g operation s ^ •

Min e wate r drainag e tunnel s i W Th e Ya k Tunnel
, whic h drain s int o Californi a Gulch
, i s th e mai n point-sourc e discharg e o f

t acidi c metal-lade n wate r i n Californi a Gulch

. Thi s tunne l drain s undergroun d minin g area s \ ^ wit h hig h concentration s o f sulfid e minerals

. I n 1983 , the Californi a Gulc h Sit e wa s place d
o n th e EPA' s Nationa l Prioritie s Lis t becaus e o f heav y metal s loadin g t o th e i Arkansa

s River

. I 2.1. 1 Climatolog y * " Th e climat e o f th e Leadvill e are a i s typica l o f mountainou s area s i n centra l Colorado

. Th e ; are a ha s extrem e temperatur e change s fro m summe r t o winte r an d i n an y seaso n ca n hav e * w rapi d change s o f weather cause d b y storm s travellin g primaril y fro m wes t t o eas t throug h th e region

. Th e loca l topographi c feature s strongl y influenc e climati c variations

. Averag e >*

- MORRISO N

KNUDSE N CORPORATIO N

• bb\1S83\FSWP.FN

L 5 [03/25/M ]annua

l precipitatio n i s 12.6 7 inche s (Res-ASARCO
, 1991)

. Jul y an d Augus t hav e th e mos t

w * precipitation ,

an d Decembe r an d Januar y hav e th e least

. Summertim e precipitatio n i s I usuall y associate d wit h convectiv e showers

. Annua l snowfal l depth s for mountain s i n th e ^ are a rang e betwee n 20 0 an d 30 0 inches

. Durin g winte r months , th e dept h o f sno w o n th e

: groun d i n Leadvill e i s commonl y si x inches

. Precipitatio n occur s sporadically , causin g L

. occasiona

l flas h floods

. Th e precipitatio n an d weathe r cycl e giv e ris e t o a n annua l pea k runoff
, usuall y occurrin g durin g June

. Th e temperatur e extreme s rang e fro m 86 F t o j j -30 F
, wit h th e averag e minimu m dail y temperatur e bein g 21.9°F

. Th e averag e frost-fre e seaso n i s 7 9 days

. Win d i s predominatel y fro m th e northwes t (CDL
, 1986b)

. 2,12 Geolog y I Th e geolog y o f th e Leadvill e Minin g distric t i s complex

. Bedroc k consist s o f th e ** * Precambria

n crystallin e rock s overlai n b y quartzites , shales , limestones , dolomites , an d 1 sandstones

o f th e Paleozoi c era . Numerou s fault s exis t a t th e eastern edg e o f th e site , u rangin g i n widt h fro m severa l fee t t o hundred s o f feet

. This faultin g wa s importan t t o

, igneou s intrusion an d subsequen t mineralization

. Pos t mineralizatio n faultin g ha s bee n ^ documente d

a s wel l (EPA
, 1989)

. \ Th e primar y mineral s deposite d b y hydrotherma l solution s whic h intrude d quartzit e an d limeston e sediments , wer e predominantl y sulfide s o f iron , zinc , an d lead , bu t also include d j copper , silve r and gold

. Late-Tertiar y tectoni c activit y faulte d th e mineralize d zone s int o *• block s an d expose d the m t o oxygenate d groun d waters

. Sulfid e mineral s wer e oxidized , > • forme d sulfuri c acid , an d release d metal s int o solution

. Thes e solution s wer e transporte d U t o carbonat e zones , wher e precipitatio n reaction s occurre d betwee n th e mineralized sulfuri c

, • aci d solution s an d th e carbonat e rock

. Thi s depositio n zon e o f secondary, o r remobilized , ^ , meta l ore s i s terme d th e oxidize d zone . Thes e carbonat e ore s wer e th e dominan t or e zone s i n man y o f th e area' s mine s (EPA
, 1989)

. 

# L Th e chang e i n geolog y i s significan t downstrea m fro m th e Pender y Fault
, whic h i s ofte n use d i t o demarcat e uppe r fro m lowe r Californi a Gulch an d i s locate d a t th e easter n edg e o f Leadville

. Abov e th e fault
, Precambria n crystallin e rock s ar e a n upthrus t relativ e t o 1 stratigraphi c

unit s o f sediment s o r alluvium

. Belo w th e fault
, thre e identifiabl e geologic *" unit s ar e noted : bedrock , lak e be d sediments , an d hig h terrac e gravels

. Th e thicknes s o f th e i uppe r an d middl e stratigraphi c unit s (gravel s an d th e lak e be d sediments ) increase s fro m U eas t t o wes t Th e uppe r uni t varie s i n thicknes s fro m approximatel y 5 0 fee t nea r th e
MORRISO N KNUDSE N CORPORATIO N M>\ia83\FSWRFN L 6 [03/23/84 ]

# I

t Pender y Faul t t o severa l hundre d fee t nea r th e Arkansa s River

. Placer operation s an d min e 

### wast e disposa l probabl y altere d th e surfac e an d near-surfac e feature s o f th e hig h terrac e • gravel s stratigraphi c uni t (EPA
, 1989)

. «-* \ 2,1. 3 Groun d Wate r ^

- Th e comple x geolog y i n th e are a ha s a significan t impac t o n groun d wate r movemen t Groun d wate r occur s i n bot h bedroc k an d alluvial systems , an d recharg e i s principall y fro m ^ infiltratio n

o f snowmel t an d rainfall

. Groun d wate r migratin g throug h th e bedroc k syste m eas t an d southeast o f Leadvill e discharge s directl y t o Californi a Gulc h surfac e waters , int o ! min e working s an d th e Ya k Tunnel
, o r int o downgradien t bedroc k o r alluvial groun d wate r ** * system s (EPA
, 1989)

. » i , *" * I n lowe r Californi a Gulch
, ther e i s a n activ e interchange betwee n th e shallo w groun d wate r ; syste m an d th e surfac e water

. Therefore
, a pathwa y exist s for meta l contaminant s t * originatin

g fro m th e Ya k Tunne l o r othe r source s tha t contribut e t o surfac e wate r

, contaminatio n

t o affec t groun d wate r quality

. Groun d wate r qualit y i s strongl y influence d ;_ , b y depth , wit h th e wors t qualit y foun d a t th e shallowe r depths

. Generally
, th e highes t meta l concentration s ar e withi n 25 t o 5 0 fee t o f th e surfac e (EPA
, 1989)

. 

# L
2.1. 4 Surfac e Wate r | Th e Californi a Gulc h Sit e are a encompasse s abou t 1 5 squar e mile s o f surfac e wate r drainag e upstrea m fro m th e confluenc e o f Californi a Gulc h wit h th e Arkansa s River

. Th e • - i mai n ste m o f Californi a Gulc h flow s eas t t o west , jus t sout h o f Leadville
, an d drain s wate r W fro m severa l smal l tributarie s t o th e nort h and south

. Th e Stra y Hors e Gulch/Star r Ditc h

t watershe d

i s th e larges t subbasi n an d drain s land s extensivel y affecte d b y minin g operations

. i » Al l tributarie s t o Californi a Gulch
, a s wel l a s th e uppe r Californi a Gulch
, ar e ephemera l A drainages

.

Californi a Gulc h receive s flow s fro m two continuou s point-sourc e discharges : th e [

_ Ya k Tunne l a t 1 t o 2 cubi c fee t per secon d (cfs ) an d th e Leadvill e wastewater treatmen t plan t a t approximatel y 1 cf s (EPA
, 1989)

. i Annua l flow s i n bot h th e Arkansa s Rive r an d Californi a Gulc h ar e normall y highes t i n th e k sprin g durin g snowmel t an d lowes t i n th e fal l an d winter

. Loca l summe r thunderstorm s are , ^ however

, potentiall y capabl e o f producin g high-intensity , short-duratio n flow s i n th e gulch

. Floodin g potentia l i s hig h becaus e o f lac k o f vegetativ e cover . Maximum floo d condition s i n th e are a ar e expecte d i n th e May-Jun e snowmel t perio d (EPA
, 1989)

. 

# I L- MORRISO

N KNUDSE N CORPORATIO N bb\1893\FSWPJN L / 103/25/W ]I I n general , "wate r qualit y i n th e uppe r Arkansa s Rive r i s degrade d belo w th e discharg e fro m the Leadvill e Drainag e Tunnel
, markedl y degrade d below Californi a Gulch
, an d improved j b y th e clean-wate r inflo w fro m creek s furthe r downstream " (EPA
, 1989)

. Th e highes t meta l

^ concentration

s occu r i n th e sprin g durin g snowmelt

. Durin g th e 1984 , 1985 , an d 198 7 investigation s b y EPA
, primar y drinkin g wate r standard s fo r cadmiu m an d lead wer e w commonl

y exceeded , a s wer e th e Ambien t Wate r Qualit y Criteri a (AWQC ) for cadmium , copper , lead , an d zin c (EPA
, 1989)

. 2.1. 5 Soil s Th e nativ e soil s o f th e Leadvill e are a occu r i n th e Troutville-Leadvill

e association

. The y ar e primaril y dee p an d well-drained , forme d i n ston y an d cobbl y glacia l outwash

. Soi l | sample s

collecte d durin g a 198 6 soi l surve y wer e foun d t o b e sand y loa m an d Pieria n * * gravell y sand y loam

. Th e samples becam e progressivel y mor e cobbl y an d gravell y wit h ; depth

. Permeabilit y an d wate r capacit y wer e estimate d a s moderate

. p H value s wer e »• moderatel

y acidi c t o neutra l i n surfac e layers

. L A significan t portio n o f th e Leadville/Stringtow n

are a ha s elevate d heav y meta l concentrations

. Thes e concentration s declin e fro m wes t t o northwest , wit h soil s closes t t o i tailings , wast e roc k piles , an d forme r smelte r site s containin g th e highes t concentration s o f lead , arsenic , an d cadmiu m (CDL
, 1986a)

. 2 2 Definitio n o f Lea d Sla g < Lea d sla g i s a metalliferou s by-produc t o f smelting , resultin g fro m the primar y processin g * ? o f lea d or e b y blas t o r reverberator y furnace s fo r th e productio n o f metal

. Specifically
, th e lea d sla g i n Leadvill e i s a n iron-ric h sla g tha t contain s approximatel y 25 % iron , substantia l W amount s o f magnesium , calciu m an d silica , a s wel l a s trace s o f residua l bas e metals

. I n

. geologica l

term s th e sla g o f th e Leadvill e are a i s simila r i n appearanc e t o extrusiv e igneou s ^ rock , blac k t o gre y i n color , ver y dense , har d (> 7 o n Moh s scale ) an d vitreous, generall y wit h a metalli c luster

. Th e majo r metalli c constituent s o f lea d sla g ar e iron , silico n an d calcium , whic h su m t o ove r i 45 % o f th e sla g b y weight

. O f th e contaminant s o f concer n a t th e Californi a Gulc h site , * * lea d an d zin c occu r a t approximatel y 1 % an d 4 % respectively , whil e arseni c an d cadmiu m i occu r a t value s les s tha n 100 0 pp m an d 2 0 ppm , respectively

. Lea d sla g exhibit s exces s

I t w MORRISO N

KNUDSE N CORPORATIO N bb\1W3\FSWP.FN L O [03/25/94 ]^ neutralizatio n

capacit y a s measure d b y pyriti c sulfu r an d neutralizatio n potentia l analyses

. Th e catio n exchang e capacit y o f sla g i s generall y low

. Th e measure d p H o f a pulverize d j sla g slurr y range s betwee n 7. 6 an d 10.1

. I

— Leachin g tests , conducte d a s par t o f the Sla g Pil e Remedia l Investigatio n (MK
, 1992)
, **

- involved bot h EP A Metho d 1312 , Syntheti c Precipitatio n Leachin g Procedur e (SPLP ) a s wel l

. , a s colum n leachin g studies

. Thes e studie s showe d minima l leachin g o f metal s o f concern . ;,_ . SPL P result s fo r al l element s wer e generall y tw o order s o f magnitud e lowe r tha n th e toxicit y characteristi c criteria , liste d i n 4 0 CF R 26124

. Additionally
, severa l tes t desig n factor s * mak e th e leachin g result s mor e aggressive tha n wha t i s expecte d unde r norma l sit e conditions

. i i , * * 2 3 Sla g Pil e Description s Sla g i s on e o f th e by-product s o f lea d or e smeltin g tha t occurre d i n Leadvill e fo r nearl y on e *• * hundred years
. A s define d i n Sectio n 2 2 o f thi s wor k plan , sla g i s a dar k vitreou s materia l i tha t i s compose d primaril y o f iron , magnesium , calcium , an d silica , wit h residua l heav y w metals

. Sla g i s har d an d relativel y dens e an d generall y exist s a s layered o r block y an d angular materia l generall y foun d ver y nea r th e forme r smelte r sites

. Figur e 2. 1 i s a ma p o f [ th e sit e tha t show s th e know n histori c lea d smelte r location s an d lea d sla g pile s sample d i n lat e 199 1 unde r the D&RG W sla g pil e R I (MK
, 1992)

. The sla g pile s wer e selecte d fo r j samplin

g base d on previou s identificatio n b y EPA
, conformanc e wit h th e definitio n for lea d slag , an d volume s greate r tha n 1,00 0 cubi c yards

. Th e genera l characteristic s an d location s

„ o f th e lead sla g pile s sample d ar e discusse d i n th e followin g subsections

. Detaile d map s an d * " dat a fo r th e individua l sla g pile s ar e presente d i n th e Final Remedial Investigation Report fo r I Lead Slag, Leadville, Colorado (RI ) (MK
, 1992)

. Stockpile d fine s currentl y exis t onl y a t th e L > Arkansa s Valley pile , but the potentia l fo r creatin g additiona l fine s pile s exist s at the othe r site s i f th e materia l i s sorted fo r som e beneficia l use
. 23. 1 Th e Arkansas Valle y Sla g Pil e |

. Th e Arkansa s Valle y (AV ) Smelte r wa s th e longes t operatin g smelte r i n th e Leadvill e area . I t wa s situate d i n lowe r Californi a Gulch
, wes t o f the cit y limits

. Sla g pile s wer e initiall y I develope d

a t th e lowes t leve l o f th e plan t towar d th e bas e o f th e slope

. Sometim e durin g * * th e 1940s , th e molte n sla g wa s discharge d wit h col d water , producin g a fine-grained
, water

- ; quenche

d slag

. Unti l thi s time , th e molte n sla g wa s poure d directl y fro m crucible s ont o th e U sla g pile , wher e i t wa s allowe d t o cool , formin g a welde d slag

. Reliabl e estimate s o f sla g

, generate d

b y th e A V smelte r hav e no t bee n made

. Base d upon aeria l photography , th e pil e MORRISO N KNUDSEN CORPORATIO N bb\1883\FSWRFN

L 9 [03/29/84 ]

# L 

# L I volum e i n th e lat e 1950 s wa s approximatel y \ 2 millio n cubi c yards

. Today
, approximatel y 423,00 0 cubi c yard s o f sla g remai n o n th e site

. Th e sla g pil e wa s purchase d b y D&RG W ! fro m ASARC O i n 1961

. Th e A V pil e i s th e larges t an d westernmos t o f th e thre e sla g pile s owne d b y D&RG W i n th e Leadvill e area . Thi s pil e wa s generate d fro m sla g produce d primaril y b y th e Arkansa s

, Valle y smelte r facility
, whic h operate d fro m 188 2 t o 196 0 unde r variou s ownerships

. Thi s L pil e i s bounded b y Leadvill e Sewag e Treatmen t Plan t propert y an d Stat e Highwa y 2 4 t o th e south , ol d smelte r work s t o th e north , woode d propert y t o th e west , an d othe r smelter

1

. relate d waste s an d Stringtow n t o th e eas t Th e Californi a Gulc h run s adjacen t t o th e sla g pil e vicinit y fo r approximatel y 1/ 5 th e lengt h o f th e pile , approximatel y 80 0 fee t (MK
, 1992)

. \ Th e A V pil e i s actuall y compose d o f a numbe r o f sub-piles

. Thes e sub-pile s ca n b e broke n I dow n int o tw o majo r types : processe d (o r sorted ) an d unprocesse d (unsorted)

. Furthermore
, * ? th e sla g wa s cooled b y tw o techniques : air-coolin g and , i n late r years , water-quenching

. Th e water-quenche d sla g i s a granula r materia l wit h particl e size s generall y les s tha n 1/4-inch

. Th e air-coole d sla g i s a mor e blocky, welde d material

. Th e A V pil e cover s a n are a o f approximatel y 200,00 0 squar e yards

. Th e maximu m dept h o f th e pil e i s approximatel y 5 0 feet
, bu t i n som e area s th e dept h i s les s tha n on e foo t 

# L

I I n th e past , th e pil e ha s bee n sorted for productio n o f railroa d ballas t Railroa d ballas t i s a potentia l futur e us e fo r th e A V slag

. Ballast-size d sla g i s define d a s tha t greater tha n 3/ 8 | ; niche s an d les s tha n 2-1/ 2 inche s i n diameter

. Materia l smalle r o r large r tha n thi s siz e i s ^ separate d

int o oversiz e an d fine s piles

. Therefore
, th e subpiles o f th e A V sit e includ e i sorted fines
, ballast-size d material , oversize d material , an d unsorte d air-coole d an d water

L i quenche

d material

. Th e volum e o f existin g sorte d fine s an d wate r quenche d fine s hav e bee n

, estimate d

a t 43,00 0 an d 150,00 0 cubi c yards , respectivel y (MK
, 1992)

. Th e sorted fine s pil e j ^ occupie s approximatel y 57,00 0 squar e fee t whil e th e wate r quenche d pil e cover s abou t 354,00 0 squar e fee t (MK
, 1992)

. Th e existin g fine s pile s an d fine s potentiall y generate d ! fro m futur e ballas t productio n wil l b e the focu s o f the Feasibilit y Study

. • 232 Th e L a Plat a Sla g Pil e Th e Berdel l an d Witherel l Smelte r firs t bega n operatio n i n 1878

. Thi s smelte r wa s locate d
> jus t wes t o f th e cit y limit s o f Leadvill e o n El m Stree t Thi s smelte r wa s a bimettalli c •

- smelter , recoverin g tw o metals , lea d an d silver

. Th e work s wer e incorporate d a s th e L a i Plat a Minin g an d Smeltin g Compan y i n 1879 , whic h smelte d ore s fro m th e L a Plat a min e 

# L MORRISO N

KNUDSE N CORPORATIO N bb\1B93\FSWRFN L 1 0 P3/23/M ]

# L

1 a s wel l a s othe r mine s i n th e are a unti l 1900

. Molte n sla g wa s transporte d o n rail s t o th e sla g pile , whic h wa s h i fron t an d sout h o f th e furnaces

. Th e L a Plat a Smelte r generate d a n 

### > estimate d

300,00 0 ton s o f slag

. Bimetalli c smelte r sla g generatio n ha s bee n estimate d a t "" " approximatel

y 457,00 0 tons

. Estimate s base d o n surve y informatio n (MK
, 1992 ) pu t th e \ curren t volum e o f sla g a t th e L a Plat a (LP ) pil e a t 111,00 0 cubi c yards

. Th e majorit y o f thi s ^ pil e i s owne d b y D&RGW
, althoug h souther n section s ar e owne d b y th e Leadvill e

. Corporation

.

D&RG W purchase d th e pil e 197 0 fro m th e Leadvill e Sanitatio n District fo r U th e purpos e o f potentia l ballas t production

. Th e pil e ha s neve r bee n use d for thi s purpos e an d n o stockpile d fine s exis t a t thi s pile

.
w Th e L P pile , owne d b y D&RGW
, als o referre d t o a s th e Supe r 8 o r Leadvill e Sanitatio n 1 Distric t pile , i s locate d approximatel y 3/ 4 mil e northeast o f th e A V pile

. I t i s northeas t o f Stringtown
, eas t an d sout h o f variou s minin g o r smelter-relate d by-product s an d wes t o f th e ; Leadvill

e In n (formerl y calle d th e Supe r 8 Motel)

. Th e L P pil e appear s t o b e compose d

w entirel y o f air-coole d slag

. Th e U P sla g pil e ha s a ver y dense ropey, welde d texture

. It s t structure

i s essentiall y monolithic , althoug h th e surfac e show s fracturing

. Thi s sla g pil e i s L irregula r i n shap e an d ha s stee p side s approximatel y 2 0 t o 3 0 fee t hig h an d cover s a n are a o f approximatel y 258,00 0 squar e fee t (MK
, 1992)

. i 23 3 Th e Harriso n Stree t Sla g Pil e i Th e easternmos t sla g pil e owne d b y D&RG W i s locate d i n th e tow n o f Leadvill e a t th e come r o f Harriso n an d Monro e Streets

. Th e pil e i s bounde d b y residence s t o th e nort h an d th e ol d smelte r sit e t o th e eas t Th e smelte r i n thi s are a cease d operatin g aroun d 1893

. *• * Th e Harriso n Stree t (HR ) pile , occasionall y referre d t o a s th e N L Industrie s pile , consist s i primaril

y o f air-coole d sla g wit h a fairl y dense , block y textur e overlayin g welde d slag

. Pil e L thicknes s range s fro m approximatel y fiv e fee t t o ove r 4 0 feet

. Th e area ! exten t o f thi s pil e i s approximatel y 18,00 0 squar e yards

. Th e coarse , angular , block y materia l varie s fro m ^ , approximatel

y eight-inc h block s t o a smalle r fractio n o f dense , plate y fragments
, o r chips , approximatel y on e inc h i n size

. Face s alon g th e side s o f th e pil e sho w th e competen t layer s 

### | o f welde d slag

. h_ > j Th e Harriso n Reductio n Work s wa s constructe d i n 187 7 a s a branc h o f th e S t Loui s Smeltin g an d Refinin g Company

. I t wa s situate d o n th e northeas t corne r o f Harriso n » Avenu e an d El m Street
, withi n th e cit y limit s o f Leadville

. Mos t o f th e ore s smelte d b y thi s i

- operatio n

cam e throug h th e AR

. Meye r Samplin g Works
, whic h wa s also owne d b y th e S t

; Loui s firm

. I n 1917 , th e Harriso n Recover y Work s wa s establishe d t o rewor k th e sla g pile

. i

* M MORR1SO

N KNUOSE N CORPORATIO N
i • tb\1C93\FSWPJN

L 1 1 P3/25/W ] 

## u

# L

i A t tha t time , i t wa s estimate d tha t th e H R pil e containe d on e millio n ton s o f slag

. Th e H R pil e wa s purchase d b y D&RG W fro m N L Industrie s i n 198 3 for potentia l ballas t production

. ;' Onl y a smal l portio n o f thi s pil e wa s processe d fo r railroa d ballast

. Base d o n th e surve y *- information
,

th e curren t volum e i s estimate d a t 106,00 0 cubi c yard s an d n o stockpile d fine s currentl y exis t a t thi s pile

. Th e H R pil e occupie s approximatel y 152,00 0 squar e fee t i

- (MK
, 1992)

. i L 2.3. 4 Othe r Sla g Pile s Othe r sla g pile s resultin g fro m lea d smeltin g als o exis t withi n th e Californi a Gulc h Site

. Th e t location

s o f fou r additiona l pile s an d histori c smelte r location s ar e indicate d o n Figur e 2.1

. On e o f thes e pile s i s i n th e Californi a Gulc h watershe d an d thre e ar e i n Evan s Gulch
, th e i majo r drainage t o th e nort h o f Californi a Gulch

. I n th e Californi a Gulc h watershed , on e *"" • sla g pil e occur s a t th e bas e o f Georgi a Gulch
, a tributar y fro m th e southeast tha t join s ; Californi a

Gulc h betwee n th e A V an d L P piles

. Th e pil e i s relativel y smal l an d consist s o f
*
, __ « - loose , block y an d welde d material

. Thi s pil e i s designate d a s th e Georgi a Gulc h (GG ) pile

.

, Thi s sla g pil e i s no t know n t o hav e bee n sample d prio r t o th e 199 2 Sla g Pil e R I (M K 1992 ) L conducte d

b y D&RGW

. Th e G G pil e occupie s a n are a o f 22,00 0 squar e fee t an d contain s a volum e o f 4,50 0 cubi c yard s (MK
, 1992)

. N o stockpile d fine s ar e know n t o exis t a t th e ! Georgi a Gulc h pile

. i Th e three pile s i n Evan s Gulc h occu r eas t o f Highwa y 24 , jus t nort h o f Leadville

. Th e pil e closes t t o th e highway , designate d Lowe r Evan s (LE)
, appear s t o b e th e remnan t o f a * previousl

y existing , larg e air-coole d pile

. The L E pil e ha s bee n removed

. The othe r pile s

~ ar e locate d one-hal f mil e upstream

. Thes e sla g pile s ar e adjacen t t o eac h othe r an d consis t

, o f a blocky, air-coole d sla g pil e [Middl e Evan s (ME) ] and a larger, welded , air-coole d pil e L [Uppe r Evan s (UE)]

. The followin g estimate d surfac e area s and volume s wer e generate d fo r eac h o f thes e tw o Evan s Gulc h pile s durin g th e R I (MK
, 1992) : Middl e Evan s are a - ^ 1930 0 squar e feet
, volum e 3,00 0 cubi c yard s an d uppe r Evan s are a 80,00 0 squar e feet
, volum e 18,00 0 cubi c yard s (MK
, 1992)

. N o stockpile d fine s ar e know n t o exis t a t th e Evan s \ Gulc h piles

.

MORRISO N KNUDSE N CORPORATIO N bb\1«S3\FSWP.FN L 1 2 (B3/25/B4 )

## u ! 3. 0 SUMMARY O F SLA G INVESTIGATION

S w
; Severa l o f th e previou s investigation s a t Californi a Gulc h hav e addresse d sla g a t th e thre e '"" D&RGW-owne d

piles

. Thi s sectio n summarize s th e relevan t dat a an d discussion s presente d ; i n th e investigatio n reports

. \ ^ 3. 1 Stat e o f Colorad o RI198 6
^ Sla g wa s no t considere d t o b e a significan t sourc e o f contaminatio n and , therefore
, wa s no t studie d durin g th e Stat e R I (CDL
, 1986b)

. Pag e 3-1 8 o f th e Stat e R I repor t state s that : 

# I Muc

h o f th e meta l i n sla g ha s bee n oxidize d i n th e smeltin g proces s an d i s i n i a

relativel y stabl e oxid e minera l form

. I n addition , smeltin g result s i n th e encapsulatio n o f muc h o f th e meta l i n refractor y site s an d i n th e formatio n o f

, silicat

e minerals

. Therefore
, altoug h (sic ) numerou s sla g pile s occu r »• * throughou

t th e stud y area , the y ar e no t expecte d t o b e a majo r sourc e o f hazardou s meta l contamination

. 

# L EP

A Phas e I I R I 198 9 \ ] ^ I n 1986 , th e EPA' s contractor, CH2 M Hill
, sample d surfac e water , groun d water , an d
numerou s min e wast e pile s (EPA
, 1989)

. Th e objectiv e o f th e min e wast e samplin g wa s t o | bette r characteriz e th e pile s i n Californi a Gulch

. Thre e o f these pile s wer e slag

. Thi s wa s w th e firs t sla g samplin g progra m undertake n b y th e EP A a t th e site

. * i * " Composit

e sample s wer e collecte d fro m location s o n eac h o f th e thre e sla g pile s base d upo n

, a gri d system o r upon a visua l approximatio n o f th e cente r an d equidistan t perimete r points

. w Th e dept h interva l a t whic h sample s wer e t o b e collecte d wa s specifie d i n CH2 M Hill' s wor k f pla n a s zer o t o si x inche s belo w th e surfac e o f th e material

. I N * Sample s wer e analyze d i n the fiel d fo r the metal s o f concer n usin g a portabl e X-ra y r L fluorescenc e

(XRF ) analyzer , an d analyze d i n a Contrac t Laborator y Progra m (CLP ) la b fo r metal s composition , extractio n procedur e (EP ) toxicit y leachin g characteristics , ; ASTM-modifie d

aci d shak e extractabl e metals , an d AST M wate r shak e extractabl e metals

. Tota l metal s analysi s yielde d result s simila r t o thos e for othe r minin g waste s i n th e area . « The repor t (EPA
, 1989 ) state d tha t whil e min e wast e pile s typicall y contai n the highes t *

- concentration

s o f arsenic , cadmium , copper , manganese , an d lead , sla g typicall y contain s th e MORRISON KNUDSE N CORPORATION

. bb\1883\FSWPJN

L 1 3 [03/25/84 ]

% "I highes t level s o f iro n an d zinc

. Sla g wa s als o show n t o contai n metal s suc h a s manganese , lead , copper , an d arsenic

. i i *" " Th e repor t note d tha t becaus e th e slags wer e generall y a soli d mas s wit h a lo w surfac e are a

, t o volum e ratio , the y woul d hav e mor e limite d solubilit y tha n othe r min e wastes

. Leachin g *W

- test s showe d tha t th e onl y meta l exceedin g th e RCR A criteri a usin g th e E P toxicit y tes t wa s lead , an d tha t thi s occurre d onl y fo r th e Harriso n Stree t an d th e L a Plat a sla g samples

. ^ Leachin

g dat a fo r al l othe r constituent s o f concer n wer e below th e E P toxicit y criteria

.

: Thi s dat a i s considere d useabl e onl y fo r limite d purpose s becaus e th e desig n and implementatio n o f th e abov e stud y di d no t resul t i n collectio n o f representativ e data

. \ Sample s

collecte d wer e o f varyin g sizes , fro m varyin g depths , an d selecte d fo r varyin g ^ particl

e sizes

. Th e resultin g composites wer e no t onl y inconsistent , bu t wer e

, unrepresentativ e

wit h respect t o size

. Particl e siz e wa s altere d b y fiel d collectio n techniques , U ofte n usin g meta l samplin g tools

. Cross-contaminatio n

o f samples wit h other min e wast e

. materia

l o r surfac e water s wa s also observe d an d documente d i n th e field

. Man y aspect s ^ o f th e XR F procedur e wer e inappropriat e fo r us e o n th e sla g pile s o r wer e improperl y performed
, makin g thos e reading s unreliable

. Finally
, th e E P toxicit y test s wer e ru n onl y
^ o n th e <20 0 mes h fractio n o f th e sample , a siz e fractio n tha t i s unrepresentativ e o f th e piles

. This tes t an d th e aci d shak e extractio n tes t ar e also overl y conservativ e an d no t i representativ e

o f sit e condition s (MK
, 1992)

. *« / \ 3. 3 Jame s P

. Wals h an d Associates

. Inc

. Soil s Investigatio n 198 8 *-- Th e state d objective s o f thi s stud y wer e t o defin e potentia l actio n level s fo r soil , determin e

. backgroun

d metal s conten t o f soils , delineat e th e exten t o f soi l contamination, an d
w . determin e

source s o f soi l contamination

. Thi s stud y wa s initiate d b y anothe r PR P an d wa s no t coordinate d wit h o r brough t t o th e attentio n o f D&RG W unti l 1991

. Thre e sample s o f

^ sla g wer e collecte d a s par t o f thi s study : on e fro m th e Harriso n Stree t pile , on e fro m th e L a Plat a pile , an d on e fro m a n are a wes t o f Leadville

. V

- Th e sample s wer e prepare d an d analyze d b y a n ASARC O laboratory

. A smal l an d
: unrepresentativ e

les s tha n 2 m m fractio n wa s extracte d wit h a nitri c acid/perchlori c aci d

' - solutio n an d analyze d fo r tota l lead , cadmium , arsenic , an d zinc

.

MORRISO N KNUDSE N CORPORATIO N

• bb\1«93\FSWP.FN

L 1 4 J03/2S/B4 Jt Th e initia l repor t o f thes e investigation s wa s a draf t repor t (Walsh
, 1988)
, i n whic h th e finding s wer e no t adequatel y supporte d b y discussio n o f methodolog y an d qualit y contro l j information

.

Also
, n o sampl e split s wer e provide d t o intereste d parties

. 3. 4 Jacob s Engineerin g Sla g Samplin g 198 9 w I n Ma y 1989 , Jacob s Engineerin g performe d th e secon d samplin g o f sla g for th e EP A

, (EPA
, 1990d)

. Th e purpos e o f th e stud y wa s t o determin e th e concentration s o f metal s i n [

_ the thre e D&RG W sla g pile s and t o evaluat e the potentia l fo r migratio n o f thes e metal s t o soil , water , o r air

. Potentia l hazard s t o th e environmen t an d publi c healt h fro m th e sla g i n i Leadville
,

a s wel l a s sla g intende d fo r us e of f site, wer e t o b e evaluated

. Mos t o f th e dat a fro m thi s stud y wa s o f goo d qualit y and considere d useabl e fo r th e intende d purposes

. i Exception

s includ e fiv e sample s tha t wer e analyze d fo r E P toxicit y that , fo r reason s discusse d below , wer e unrepresentativ e an d o f questionabl e quality , acid-bas e accountin g * dat a tha t wa s conservativ e an d no t substantiate d b y split sampl e results , an d som e particl e | \ M siz e dat a tha t wa s inadequat e t o evaluat e th e percen t o f respirable-size d slag

. 4 ^ I n orde r t o obtai n a preliminar y evaluatio n o f th e variabilit y withi n th e sla g piles , fou r location s wer e sample d a t eac h o f th e followin g piles : th e Harriso n Stree t pile , L a Plat a ! pile , A V oversize d an d unprocesse d subpiles , A V sorte d fine s subpile , A V ballast-size d subpile , an d A V water-quenche d fine s subpiles

. Sample s wer e collecte d fro m th e cente r o f i individua l

pile s o r pil e quadrant s usin g shovels , a backhoe , o r a rippe r blad e an d a backhoe

. ±~j Surfac e sample s (zer o t o si x inches ) wer e collecte d a t al l locations

. Subsurfac e sample s (a t ; approximatel

y thre e feet ) wer e als o collecte d fo r eac h pil e excep t the A V sorte d fine s and t
~ ballast-sized

, whic h wer e assume d t o b e homogeneou s afte r sorting

. Sampl e siz e wa s ( determine d

accordin g t o AST M D-7 5 (ASTM
, 1987 ) weigh t recommendations ,

whic h ar e w base d o n particl e siz e o f th e materia l t o b e sampled

. 1 ^ Sample s wer e analyzed fo r 2 3 targe t analyt e lis t (TAL ) metal s accordin g t o CL P procedures

. Tota l sulfu r an d neutralizatio n potentia l wer e determine d b y EP A Method s 3.2. 4 an d 3.2.3 , i respectively

.

Particl e siz e distributio n wa s determine d b y bot h th e siev e an d th e hydromete r L
— tests , adjustin g th e hydromete r reading s fo r th e specifi c gravit y o f slag

. Leachabilit y wa s evaluate d wit h th e sam e three test s use d previousl y b y th e EPA : E P toxicity , ASTM

- ^ modifie d

aci d shak e extraction , an d AST M wate r shak e extraction

. Leachin g test s wer e

. performe d

onl y on th e ballast-size d an d th e sorte d fine s samples

. Sampl e preparatio n U deviate d fro m standar d procedure s i n a n effor t t o mak e th e testin g mor e representative : sla g wa s no t groun d o r pulverize d prio r t o leachin g tes t extractions

. MORRISO N KNUDSE N CORPORATIO N bb\1883\FSWP.FN L 1 5 [03/25/94 ]

# 1 1 i- S The mos t significan t result s fo r the particl e siz e analysi s ar e the percentages o f fin e materia l (passin g th e 20 0 mes h sieve ) i n eac h pile

. Fo r th e Harriso n Stree t pile , L a Plat a pile , an d A V ballast-sized , oversized , an d unprocesse d subpiles , fine s wer e presen t a t approximatel y 0. 5 weigh t percen t Th e A V sorte d fine s an d th e water-quenche d fine s subpile s containe d 5 an d 1. 5 weigh t percen t materia l passin g th e 200-mes h sieve , respectively

. Th e result s o f th e thre e leachin g test s sho w tha t non e o f th e RCR A metal s leache d fro m sla g i n concentration s exceedin g th e RCR A criteri a o f 10 0 time s th e drinkin g wate r standards

. Fiv e additiona l E P toxicit y test s wer e performe d b y th e EP A tha t wer e no t calle d fo r i n th e samplin g plan

. Th e test s wer e ru n o n materia l passin g th e 10-mes h siev e fro m sample s wit h th e highes t tota l metal s concentration s fro m eac h pil e o r subpil e tha t ha d no t bee n previousl y teste d fo r leachability

. Lea d wa s th e onl y meta l tha t exceeded th e RCR A criteri a an d thi s occurre d i n thre e o f th e fiv e samples

. I t shoul d b e note d tha t th e percen t passin g a 10-mes h siev e range s fro m <0. 5 t o 6. 0 weigh t percen t fo r thes e thre e samples

. Therefore
, th e fractio n teste d constitute s onl y a ver y smal l portio n o f th e sla g an d i s no t representativ e o f th e piles

. N o qualit y contro l dat a wa s presente d wit h thes e results , no r ^ wa s th e opportunit y t o ru n spli t samples presented , s o th e validit y o f thes e result s canno t b e determined

. Thes e fiv e sampl e result s are considere d unrepresentativ e an d o f ! questionabl

e qualit y (MK
, 1992)

. I n addition , th e E P toxicit y tes t conducte d i s als o ver y » — » aggressive

an d unrepresentativ e o f condition s i n th e Californi a Gulch

. Thi s tes t wa s ) designe d

t o simulat e situation s i n whic h a wast e i s co-dispose d i n a municipal landfil l an d

w saturate d

wit h organi c acid

. *

- Statistica l

evaluatio n o f th e dat a show s tha t th e sla g pile s diffe r i n composition , wit h th e exceptio n o f som e o f th e A V subpiles

. Chemica l an d particl e siz e variabilit y withi n pile s w wer e no t significant
, no r wer e th e difference s betwee n surfac e an d subsurfac e chemistr y (EPA
, 1990)

. \ w 3. 5 Summar y o f D&RG W Sla g Pil e Remedia l Investigatio n Activitie s D&RG

W conducte d a Remedia l Investigatio n int o th e Sla g Pile s durin g 199 1 an d 1992

. Th e inten t o f th e R I wa s t o characterize majo r lead sla g pile s i n sufficien t detai l suc h tha t \ thei r chemica l an d physica l propertie s coul d b e evaluate d fo r potentia l impact s o n huma n w healt h an d th e environment

. Researc h fo r th e Sla g Pil e RI wa s performe d t o determin e th e ; forme r smelte r location s an d the histor y an d present ownershi p o f the sla g piles

. The fiel d t U investigatio n

phas e consiste d o f reconnaissanc e o f th e histori c smelte r site s o f Leadvill e for th e identificatio n o f existin g lea d sla g piles , an d surveyin g an d samplin g o f selecte d lea d sla g i * * w MORR1SO

N KNUDSE N CORPORATIO N

1 bb\18S3\FSWPJN

L 1 6 103/25/84 ] V 1

- *) piles

. Th e laborator y investigatio n phas e include d th e determinatio n o f th e physical , ^af chemica

l compositional , an d leachin g characteristic s o f th e samples

. A n overvie w o f eac h ) phas e i s presente d i n th e followin g sections

. Mor e detaile d description s o f activitie s ca n b e foun d i n th e Fina l Lea d Sla g R I (MK
, 1992)

. Iw 3.5. 1 Historica l an d Ownershi p Researc h Th e historie s o f th e sla g pile s an d thei r paren t smelter s wer e researche d an d summarize d • ^ i n orde r t o estimat e th e location , year s o f operatio n o f th e smelters , an d th e approximat e amoun t o f sla g generated

. Curren t an d histori c aeria l photograph y wa s also reviewe d t o i sca n th e stud y are a fo r previousl y unlocate d sla g piles

. Ownershi p researc h o f th e sla g pile s f e w selecte d fo r samplin g wa s performe d t o facilitat e permissio n fo r access
. i \ •- 3.5. 2 ReldWor k / ; A fiel d reconnaissanc e o f th e know n histori c smelte r location s wa s performe d t o locat e al l U sla g pile s at the Californi a Gulc h Site

. The vicinit y o f eac h pil e wa s describe d fo r other smelte r waste s o r debri s an d an y apparen t impact o f th e sla g o n th e environment

. Sla g pil e ^ structural/geotechmca l

stabilit y condition s wer e also noted

. Th e pile s selecte d fo r samplin g wer e surveye d b y a professiona l surve y tea m unde r th e supervisio n o f a registere d lan d surveyor
. Elevatio n dat a o f th e sla g pil e perimeter , tops , I toe s an d grad e break s wer e recorde d s o tha t pil e heights , sid e slop e angle s o f repose , an d pil e volume s coul d b e calculated

. t
~ A total o f seve n lea d sla g pile s wer e sampled

. Thes e include d th e Arkansa s Valley ;

, L a Plata ; Harriso n Street ; Georgi a Gulch ; an d Upper
, Middl e an d Lowe r Evan s Gulc h pile s ^

. (Figur e 2.1)

. Sampl e location s wer e identifie d b y overlayin g a numbere d gri d cel l syste m o n th e sla g pil e bas e maps

. Rando m number s wer e generate d t o selec t th e location s t o b e I sample d (MK
, 1991b)

. Fo r th e D&RGW-owne d pile s (Arkansa s Valley
, L a Plata
, an d te ^ Harriso n

Street)
, fou r discret e bul k samples wer e collected

. Fo r th e remainde r o f th e piles , } a n attemp t wa s mad e t o collec t fou r samples fro m eac h pil e fo r compositing ; however , a t th e Uppe r Evan s an d Middl e Evans
, onl y thre e an d on e sample , respectively , coul d b e j collecte d

du e t o lac k o f acces s t o th e pil e wit h th e backhoe

. Th e sla g wa s sample d b y ^ excavatin

g fro m zer o t o thre e fee t A weigh t considere d t o b e representative , base d o n i grai n size , wit h a maximu m o f fou r hundre d pound s wa s collected

. Furthe r detail s o f th e U samplin g procedur e ma y b e foun d i n th e Samplin g an d Analysi s Plan (MK
, 1991a)

. Thi s materia l wa s homogenize d o n a shee t o f hig h densit y polyethylen e (HDPE)
, coned , t • w MORR1SO

N KNUDSEN CORPORATIO N bb\1883\FSWPJ=N L 1 7 [03/29/94 ] V"— *1 quartered

, an d sampled

. I n additio n t o bul k sampling , "ol d slag " an d subsla g samplin g wa s •b ^ conducted

a t th e D&RGW-owne d piles

. Th e definitio n o f "ol d slag " ma y b e foun d i n th e { Wor k Plan (MK
, 1991a)

. Tw o sample s pe r pil e wer e collecte d fro m area s designate d a s ^ containin

g "ol d slag" ; fou r samples o f soi l fro m beneat h th e Arkansa s Valle y pil e wer e 

### collected ; an d thre e sample s o f soi l wer e collecte d fro m beneat h bot h th e L a Plat a an d th e w Harriso n

Stree t piles

. A total o f 5 6 location s wer e sampled

.

^ Sample s wer e processe d fo r analysi s i n th e followin g manner . Fo r chemica l compositiona l testing , a sampl e fractio n o f approximatel y sixt y pound s wa s crushe d t o minu s 1/4 " an d I mixed

. Te n pound s o f th e mixe d materia l wa s the n pulverize d t o les s tha n 25 0 micron s Own)
, mixed , an d place d i n ten sampl e bottles

. Thi s <25 0 // m materia l wa s submitte d fo r \ chemica

l compositiona l and meta l speciatio n analyses

. Th e inten t o f th e preparatio n ste p * " wa s t o suppl y al l analytical program s wit h material s tha t wer e equall y representativ e o f th e ; , , chemica l compositio n o f th e sla g collecte d a t th e piles

. Particl e siz e an d leachin g test s wer e L performe d

withou t sampl e siz e reduction

. 3.5 3 Laborator y Analyse s Particl e siz e analyse s wer e performe d o n samples tha t contained appreciabl e quantitie s o f i fin e particle s b y visua l inspectio n usin g sieve , hydromete r an d microtra c techniques

. ** * j Th e tota l compositio n o f th e sample s wa s determine d b y EP A CL P method s describe d i n w Statemen t

o f Wor k (SOW ) 4/9 0 (EPA
, 1990c ) an d a Burea u o f Mine s sampl e digestio n : metho d (MK
, 19 9 Ib)

. The analytes include d the 2 3 TA L metal s wit h the additio n o f silico n i

- an d exclusio n o f mercury . Othe r analyte s include d th e anions : sulfate
, nitrate , nitrit e an d chlorid e a s wel l a s th e followin g form s o f sulfur : total , pyritic , an d non-extractable

. Catio n v*

. exchang e capacit y an d neutralizatio n potentia l wer e also quantified

. i 1 Tw o type s o f leac h testin g wer e performe d o n the samples

. Al l sample s wer e submitte d fo r analysi s usin g th e Syntheti c Precipitatio n Leachin g Procedur e (SPLP ) EP A Metho d 1312 , \ / * (5 7 F R 21450 , Hazardous Wast e Identificatio n Rule
, Ma y 20 , 1992)
, withou t particl e siz e reduction

. SPL P i s a 24-hou r shake r tes t usin g a simulate d rai n wate r lixivian t wit h nitri c i an d sulfuri c minera l acid s i n concentration s resultin g i n a p H o f 5

. Th e eluat e wa s analyze d

^ fo r metal s and , i n som e cases , anions

. Si x samples wer e selecte d fo r colum n leac h testing

. • Thi s tes t introduce d th e sam e lixivian t t o three-foo t column s containin g sla g o r subsla g L

. material

. Th e quantitie s o f lixivian t use d simulate d one-inc h rainfal l event s ove r a on e hou r period

. Applicatio n wa s followe d b y on e hou r o f drainage an d aeration

. Thi s procedur e \

^ w MORRISO N

KNUDSE N CORPORATIO N bb\1BS3\FSWP.FM

.

I S 103/23/64 ]

### ] wa s repeate d fo r 10 0 cycles

. Th e eluat e wa s collecte d an d analyze d fo r metal s and , i n som e * * cases , anions

. Bot h leachin g test s wer e designe d t o estimat e metal s teachabilit y o f th e pile s

, unde r natural , i n situ , weatherin g conditions

.
w » 3.5. 4 Sla g Pil e Conceptua l Mode l

^

_ Th e purpos e o f th e R I wa s t o characteriz e th e majo r lea d sla g pile s i n sufficien t detai l suc h tha t thei r physica l an d chemica l propertie s coul d b e evaluate d fo r potentia l impact s o n | huma n healt h an d th e environment

. Th e R I dat a wa s use d t o asses s th e viabilit y o f fiv e • w' - • •••*• •' potentia l release mechanism s identifie d i n th e sit e conceptual model

. Thes e fiv e releas e ; mechanism

s include d wind , leaching , mixin g b y huma n activities , runof f o f particulates , an d

w direc t contac t Direc t contac t wa s discounte d i n th e baseline huma n healt h ris k assessmen t i conducte d

b y EPA
, leavin g fou r remainin g mechanism s t o b e evaluated

. 

## L Th e ai r pathwa y analysi s result s showe d tha t win d erosio n i s no t a releas e mechanis m i n ^ Leadville

.

Hourl y averag e win d spee d dat a multiplie d b y the appropriat e facto r t o determin e th e maximu m sustained win d gus t doe s no t mee t o r excee d th e velocit y necessar y ; t o lif t particle s of f th e stationar y pile

. Th e conclusio n reache d wa s tha t win d erosio n i s no t
a viabl e releas e mechanis m fo r th e lead sla g piles , includin g th e A V water-quenche d an d 1 sorte d fine s piles

.

: Leachin g o f constituent s o f concer n fro m lea d sla g wa s teste d b y tw o differen t leachin g ^

- procedure

s (SPL P an d colum n leach ) yieldin g th e quantit y o f metal s leache d fro m a give n mas s o r volum e o f a sla g pile

. A t th e conclusio n o f th e R I leachin g wa s retaine d a s a L potentia l releas e mechanism

.

^ Transpor t

b y huma n activitie s ha s occurred , a s sla g wa s historicall y use d fo r roa d maintenanc e withi n th e site

. Sla g ha s no t bee n use d withi n th e sit e for thes e purpose s for I severa l year s an d i s no t contemplate d t o b e use d i n thes e way s i n th e future

. Th e characteristic s o f sla g o n th e railroa d track s (ballast ) ar e represente d b y th e result s fo r th e * A V ballast-size d subpil e samples

. Th e ballast-size d sampl e result s sho w a lo w potentia l fo r *

~ leachin g (wel l below toxicit y characteristi c criteria)

. Base d o n fiel d observation s an d chemica l analysi s o f th e soil s beneat h th e sla g piles , i t ca n b e conclude d tha t subsla g soil s L hav e no t bee n significantl y impacte d b y th e placement o f slag

. Th e concentratio n o f element s o f concer n i n subsla g materia l i s ver y low

. Thi s potentia l releas e mechanis m wa s i l

_ eliminate d b y th e RI

. MORRISO N KNUDSE N CORPORATIO N bb\1B93\FSWP.FN L 1 9 P3/2S/B4 ]1 N o evidenc e o f transpor t o f sla g fine s b y surfac e runof f wa s observe d a t an y o f th e pile s examined

. Sla g doe s no t appea r t o b e transporte d fro m pile s ont o adjacen t soil s i n rivulet s j

. o r channels

. Pil e integrity , especiall y fo r fine s pile s wher e thi s i s mos t critical , appear s ^ intact

. Pil e integrit y wa s evaluate d base d o n structura l stability , deflatio n potentia l an d

. effect s o f freeze/tha w cyclin g durin g the R I (MK
, 1992)

. Thi s potentia l release mechanis m *

~ wa s eliminate d b y th e RI

. \ l ^ 3. 6 Conclusion s fro m al l o f th e Sla g Investigation s A s a resul t o f th e variou s remedia l investigations , an d mos t particularl y th e Fina l Sla g Pil e ; Remedia

l Investigatio n (MK
, 1992)
, i t ha s bee n conclude d tha t ballas t size d sla g materia l (3/8"- 2 1/2" ) an d large r block y sla g materia l pos e n o threa t t o huma n healt h an d th e ; environmen

t EP A ha s conclude d tha t ballas t operation s ma y resume , pendin g approva l o f
a pla n describin g operationa l methodolog y (EPA
, 1993a)

. Th e result s o f th e RT s wer e les s \ conclusiv

e regardin g th e fin e fractio n o f sla g resultin g fro m ballas t sortin g operation s an d *- * fin e sla g generate d fro m wate r quenche d sla g production

. Th e potentia l pathway s a s describe d i n th e sit e conceptua l mode l wer e discusse d i n th e R I an d eac h o f th e fiv e wer e v, , eliminate d

except fo r th e retentio n o f leachin g whic h wa s retaine d a s a possibl e pathwa y o f
concer n fo r fin e slag

. ir

MORRISO N

KNUDSE N CORPORATIO N bb\1883\FSWP.FN L 2 0 [03/29/84 ]

### L 4. 0 SUMMAR Y O F RESULT S O F TH E SCREENIN G FEASIBILIT Y STUD Y 

# L

- A Screenin g Feasibilit y Stud y (SFS ) (EPA
, 1993 ) wa s conducte d t o develo p an d evaluat e | possibl e respons e alternative s fo r addressin g contro l o f and/o r remediatio n o f the variou s *~ " source s a t th e Californi a Gulc h Site

. Th e SF S initiate d th e overal l CERCL A Feasibilit y Stud y proces s an d develope d an d screene d remedia l actio n alternative s applicabl e t o slag

. L

- On e importan t conclusio n o f th e RI/SF S proces s for sla g wa s tha t fin e sla g wa s th e onl y

, materia

l o f concer n an d large r sla g (ballas t size d an d block y slag ) wa s determine d b y EP A * L t o b e availabl e fo r D&RGW s use
. The SF S provide d the framewor k fo r proceedin g wit h th e Fina l Feasibilit y Stud y fo r stockpile d sla g fines

. Th e SF S screene d th e lis t o f alternative s 1^

. t o thre e alternatives whic h wil l b e evaluate d i n detai l i n th e Fina l Feasibilit y Study

. Th e retaine d alternative s are : I •

N o Actio n t •

Institutiona l Control s *• * •

Resourc e Utilizatio n i

_ Th e majo r activitie s conducte d i n th e SF S wer e a s follows :

^ 1

.

Identificatio n o f Remedia l Actio n Objective s 2

. Identificatio n an d Screenin g o f Technolog y Type s ; 3

.

Development an d Analysi s o f Remedia l Alternative s jta* » 4

.

Presentatio n o f Applicabl e o r Relevan t an d Appropriat e Requirement s \ (ARARs

) w i 4. 1 Identificatio n o f Remedia l Actio n Objective s W Unlik e othe r medi a addresse d b y th e FS
, th e Remedia l Investigatio n (RI ) fo r th e Sla g Piles ha s bee n finalized

. A compariso n o f th e R I result s t o th e conceptual mode l showe d tha t L onl y on e potentia l releas e pathwa y wa s retaine d a s viabl e fo r th e sla g fines

. Th e on e retaine d potentia l releas e pathwa y wa s examine d an d on e remedia l actio n objectiv e (RAO ) \ wa s formulate d t o addres s thi s potentia l pathway

. Th e remedia l actio n objectiv e fo r th e stockpile d fine s a t sla g pile s i s t o preven t leachin g o f metal s o f concer n i n concentration s i tha t woul d hav e a n advers e impac t o n soils , surfac e o r groun d wate r i n th e vicinit y o f th e *" " sla g piles

. t ±~t MORRISO N

KNUDSE N CORPORATIO N

^ bb\1893\FSWPJN

L 2 1 (03/29/B4 ]
k» W4 2

Identificatio n an d Screenin g o f Technologie s Type s
^ ———————————— — —— — ——————

— ———————•JC————

— ———————" »

"———**^-
= A summar y o f th e identificatio n an d screenin g o f technolog y type s fo r sla g i s presente d i n

, th e followin g sections

. i — » 42. 1 Potentiall y Applicabl e Technologie s an d Proces s Option s fo r Sla g Piles w Tabl e 4- 1 list s al l o f th e technologie s an d proces s option s tha t wer e considere d technicall y implementabl e at the Californi a Gulc h site

. I n the SFS
, genera l respons e action s relativ e [

_ t o the al l state d remedia l actio n objective s fo r al l sourc e area s wer e developed

. The develope d genera l respons e action s ar e broa d classe s o f action s whic h ma y b e implemente d

^ alone , o r i n combination , t o satisf y th e remedia l actio n objectives

. Th e criteri a o f technica l implementabilit y wa s applie d t o th e universa l Us t o f remedia l technologies an d proces s * options

. Th e Ust
, afte r deletio n o f thos e remedia l technologie s an d proces s option s tha t wer e considere d no t t o b e technicall y implementabl e a t th e Californi a Gulc h Site
, i s presente d i n Tabl e 4- 1 o f thi s wor k plan

. Thi s Us t wa s the n compare d t o th e remedia l actio n objectiv e fo r sla g an d th e critieri a o f effectiveness
, implementabilit y an d cos t wer e use d t o furthe r scree n thi s Ust

. Th e survivin g remedia l technologie s an d proces s option s wer e the n compile d int o remedia l alternatives designe d t o address th e remedia l actio n objectiv e fo r slag

. Th e remedia l alternative s ar e presente d i n Tabl e 4-2

. 

# L

42 2 Screenin g Criteri a Th e retaine d technologie s an d proces s option s wer e evaluate d usin g th e criteri a o f effectiveness
, implementabilit y an d relativ e cos t i n accordanc e wit h EP A Guidanc e fo r conductin g Remedia l Investigation s an d Feasibilit y Studie s unde r CERCL A (EPA
, 1987)

. Effectivenes s relate s t o th e potentia l effectivenes s o f th e technolog y o r proces s optio n i n handlin g th e estimate d area s o r volume s o f th e sla g pile s an d meetin g th e remedia l actio n objectiv e tha t ha s bee n defined

. Overal l reductio n i n toxicity , contaminan t mobilit y o r sourc e volum e tha t i s achieve d b y implementatio n o f th e proces s optio n wa s als o considere d i n th e effectivenes s criteria

. Potentia l impact s t o huma n healt h an d th e environmen t durin g th e constructio n an d implementatio n phas e a s we U a s th e reliabilit y o f th e proces s wit h respec t t o th e Californi a Gulch sit e condition s wer e also considered

. Bot h short-ter m (durin g implementation ) activitie s an d lon g ter m period s wer e considered

. Implementabilit y relate s t o technica l maturit y an d feasibilit y (i.e.
, abilit y t o construc t an d reUabl y operat e th e syste m an d mee t regulations ) an d administrativ e feasibilit y (i.e.
, abilit y MORR1SO N KNUDSE N CORPORATIO N bb\1893\FSWP.FN L 2 2 [03/2S/64 ]

## L
1 t o ge t permits , t o procur e treatment , storag e an d disposa l services , an d t o procur e neede d V r f land , equipmen t an d expertise)

. Fo r purpose s o f th e screening , th e degre e o f i , implementabilit

y wa s characterized a s "high, " "medium, " o r "low"

. A proces s optio n wit h



### ~ "high " implementabilit y i s relativel y eas y t o construc t o r pu t int o practic e a t thi s site , an d i s reliabl e an d eas y t o permi t du e t o it s technica l maturity

. A "medium " characterizatio n •K,

- applie s t o a proces s optio n tha t i s commerciall y availabl e bu t no t widel y use d fo r th e specifi c application

. This characteristi c woul d als o appl y t o thos e technologie s or option s tha t hav e • ^ som e difficult y i n permittin g an d potentia l constructabilit y o r operabilit y problems

. A proces s wit h low " implementabilit y ma y no t b e commerciall y available , suc h a s innovativ e i o r emergin g technologies

. Thi s characteristi c woul d als o appl y t o thos e technologies o r option s tha t woul d b e unworkabl e a t th e Californi a Gulc h sit e o r difficul t t o permi t an d | hav e significan t constructabilit y or operabilit y problem s for th e particula r source
. -i w i Cos t screenin g a t thi s stag e involve d preparatio n an d compariso n o f relativ e estimate s t o U scree n equall y effectiv e bu t significantl y higher cos t options

. Fo r purpose s o f the screenin g FS
, cost s o f technologies o r proces s option s wer e characterized a s "high, " medium, " o r "low "
^ relativ e t o on e another

.

: 42 3 Screenin g o f Potentiall y Applicabl e Remedia l Technolog y Proces s Option s fo r Sla g •" * Pile s ; Tabl e 4- 1 list s th e technologie s an d proces s option s tha t wer e considered technicall y w implementabl

e an d applicabl e fo r sla g piles

. Eac h proces s optio n wa s characterized base d
o n effectiveness
, implementabilit y an d relativ e cos t wit h relativ e indicator s o f thes e criteria

. 

### L

- ( Th e proces s options evaluate d an d th e basi s fo r retentio n ar e describe d i n detai l i n th e L r Screenin g Feasibilit y Study

. Thos e remedia l technolog y proces s option s tha t wer e retaine d fo r assemblag e int o remedia l actio n alternative s ar e liste d i n Tabl e 4- 1 an d a complet e ^ descriptio n

ma y b e foun d i n th e SFS

. \ 4 3 Developmen t an d Analysi s o f Remedia l Actio n Alternative s ^ Th e remedia l technologie s an d proces s option s tha t hav e bee n screene d an d th e remainin g | technologie

s an d proces s option s wer e assemble d t o formulat e remedia l actio n alternative s ^ fo r th e sla g piles

. U Th e retained technologie s wer e assemble d t o formulat e Remedia l Actio n Alternatives

. Genera l descriptions fo r th e Remedia l Actio n Alternative s fo r th e sla g pile s ar e describe d 

### • u MORRISO N

KNUDSE N CORPORATIO N bb\1S83\FSWP.FN L 2 3 [03/2S/M ] W ^! below

. Eac h o f th e alternative s wa s screene d t o creat e th e shor t lis t o f alternatives , an d meet s th e RA O o f preventin g metal s o f concer n fro m leachin g fro m th e sla g pile s i n i concentration

s tha t woul d hav e advers e impact s o n th e environmen t Screenin g o f th e u alternative

s include d preliminar y determination s o f effectivenes s i n achievin g th e RAO
, technica l an d administrativ e implementability , an d cos t I t shoul d b e note d tha t a t thi s time ,

-— • cost s ar e relativ e an d hav e bee n categorize d onl y a s low , mediu m an d high

.

^ Th e screenin g o f alternative s i s provide d i n Tabl e 4-2

. Alternative s retaine d afte r thi s proces s ar e s o note d i n Tabl e 4- 2 an d describe d i n th e followin g section

. This section } detail s the shor t lis t o f retaine d alternative s fo r the sla g pile s base d upo n the identifie d Remedial Actio n Objectiv e an d th e screenin g processes

. j
^ Th e retaine d alternative s ar e presente d below

.

» ~ Alternativ e

1 - N o Actio n

, N o action , sla g pile s lef t i n place

. w Alternativ e

2 - Institutiona l Control s

, Institutiona l

control s involv e restrictin g acces s o r activitie s tha t coul d increas e th e potentia l fo r leachin g fro m slag

. Control s includ e fencing
, land-us e restrictions , an d dee d restrictions

. j Additionally
,

communit y awarenes s program s coul d b e implemente d whic h woul d b e usefu l

w i n alertin g th e communit y t o an y hazard s associate d wit h thi s potentia l sourc e material

. 

### Control s coul d b e implemente d separatel y o r i n combination

. Coordinatio n wit h stat e an d

^

- loca l agencie s woul d b e required

. Periodi c monitorin g ma y b e require d t o ensur e tha t an y

, restriction

s remai n i n force

. i L r Alternativ e

3 - Resourc e Utilizatio n

w Th e utilizatio n o f sla g a s a resourc e coul d involv e a numbe r o f activitie s and/o r processes

. Thi s alternativ e include s usin g sla g a s railroa d ballast , wit h undersize d materia l use d a s a n \ additiv e

materia l i n construction

. An y oversize d materia l lef t afte r screenin g ou t th e ballast

size d materia l woul d b e crushe d t o augmen t th e ballas t material

. Example s o f use s fo r th e 1 undersize d

materia l woul d b e a s a n aggregat e fo r concret e o r asphal t manufacturing
, a n L

~ additiv e t o buildin g material s suc h a s cinde r blocks , an d a n additiv e t o grout , shotcret e o r • slurr y formulations

. I 4. 4 ARAR s Analysi s MORRISO N KNUDSE N CORPORATIO N bb\1893\F8WPJN L 2 4 103/25/04 ]] Un< ! s r th e Superfun d Amendment s an d Reauthorizatio n Ac t o f 198 6 (SARA)
, determinatio n o f Applicabl e o r Relevan t an d Appropriat e Requirement s (ARARs ) i s required , an d i potentia l

remedia l alternative s shoul d b e considere d a t th e initiatio n o f a Remedia l U Investigation/Feasibilit

y Stud y (RI/FS)

. •>

- A s par t o f th e RI/FS
, remedia l measure s ar e evaluated t o asses s th e degre e t o whic h the y attai n o r excee d applicabl e o r relevan t an d appropriat e Federal
, Stat e an d loca l publi c [

_ healt h an d environmenta l standards

. Thes e cleanu p standard s are foun d i n environmenta l law s othe r tha n CERCL A an d ar e impose d upo n th e sit e cleanup

. CERCL A doe s no t I includ e cleanu p standard s an d Sectio n 12 1 mandate s th e impositio n o f th e requirement s develope d pursuan t t o othe r environmenta l laws

. Differen t ARAR s tha t ma y appl y t o a sit e | an d it s remedia l activitie s ar e identifie d a t multipl e point s i n th e remed y selectio n process

. -L r

. Th e SF S presente d a n appendi x concernin g ARAR s fo r th e entir e site

. Th e Fina l F S wil l

^

- begi n wit h thi s lis t o f ARAR s an d focu s th e evaluatio n o n thos e ARAR s tha t ar e o f

, importanc e

t o sla g fines

. L 

## L

MORRISO N

KNUDSE N CORPORATIO N bb\1«83\FSWP.FN L 2 5 (03/25/84 ]

## L
5 . 0 FINA L FEASIBILIT Y STUD Y A s state d i n th e Statemen t o f wor k fo r D&RGW s Consen t Decree
, th e thre e retaine d alternative s fro m the screenin g feasibilit y stud y (SFS ) wil l b e evaluate d i n detai l i n the Fina l Feasibilit y Stud y fo r stockpile d fine s at th e sla g piles

. I n th e SF S i t wa s determine d tha t th e thre e retaine d alternative s satisf y the remedia l actio n objectiv e o f preventin g leachin g o f metal s o f concer n i n concentration s tha t caus e advers e impact s t o soils , groun d wate r an d surfac e wate r i n th e vicinit y o f th e sla g piles

. Th e detaile d analysi s o f alternative s consider s th e nin e evaluation criteri a of :
• Overal l protectio n o f huma n healt h an d th e environmen t • Complianc e wit h ARAR s • Long-ter m effectivenes s an d permanence • Reduction o f toxicity , mobilit y o r volum e • Short-ter m effectivenes s • Implementabilit

y • Cos t • Stat e acceptanc e • Communit y acceptanc e Th e result s o f th e detaile d analysi s provid e th e basi s fo r identifyin g a preferre d alternativ e an d preparin g the propose d plan

. Upo n completio n o f the detaile d analysis , the F S repor t wil l b e prepare d and , alon g wit h th e propose d plan , submitte d fo r publi c revie w an d comment

. Fina l selectio n o f a remedia l actio n wil l occu r followin g th e commen t perio d an d wil l for m th e foundatio n fo r th e Recor d o f Decision

. Th e Fina l F S wil l ultimatel y suppor t remed y selectio n an d developmen t o f a Recor d o f Decisio n b y th e EPA

. Th e result s o f th e ongoin g ris k assessmen t activitie s ma y ultimatel y affec t th e remed y selection , but , accordin g t o EPA' s schedule , ma y no t b e availabl e fo r incorporatio n i n th e fina l FS

. Recently
, a technica l memorandu m ha s bee n release d b y Alie n Medin e o f Wate r Scienc e (Medina
, 1994 ) whic h attempt s t o mode l th e contaminan t transpor t t o th e Californi a Gulch

. The strea m segment s relativ e t o the stockpile d fine s pile s includ e CG0 4 t o CG0 5 and CG0 5 t o CG06

. Th e repor t (Medine
, 1994 ) demarcate s al l sla g a s bein g o f "lesso r significance " wit h regar d t o contributio n o f leaching

. Further
, base d upo n th e leachin g studie s conducte d i n th e RI
, M K 1992 , th e loadin g o f lea d calculate d fro m th e leachin g test s (1 3 kg/year ) MORRISO N KNUDSE N CORPORATIO N bb\1883\FSWP.FN L 2 6 (03/35/84 ]

## L j ^ compare d wit h th e loadin g whic h wa s observe d i n th e yea r 1991-199 2 (Tabl e 2 , Medine
, 1994 ) 18,65 1 kg/yea r a t strea m segmen t CG05

. CG0 5 i s th e strea m gaugin g statio n whic h * i s downstream o f potentia l impact s o f th e fin e slag

. Additionally
, th e valu e o f 1 3 kg/yea r ^ i s base d o n leachin g test s specificall y designe d t o overestimat e th e leachin g potentia l o f th e slag

. I t shoul d als o b e note d tha t no t detectabl e concentration s o f lea d coul d b e extracte d ^- fro m th e sla g unti l approximatel y one-hal f wa y throug h th e testin g period

. Relyin g o n thos e conclusions, the analysi s conside r the mas s o f lea d availabl e fo r releas e fro m the fine s pil e i_ , (pe r uni t time ) divide d b y th e flo w i n th e Californi a Gulc h (pe r uni t time ) fo r eac h o f th e thre e alternatives

. Thi s analysi s ma y includ e suc h factor s a s sorptio n an d surfac e wate r ^ discharg e

t o groun d water

. j 5. 1 Detaile d Analysi s o f Alternative s Fo r th e fina l F S th e detaile d analysi s o f alternative s consist s o f th e followin g components :
*

- • A n assessmen t an d a summar y profil e o f eac h alternativ e agains t th e evaluatio n criteria

. • A comparativ e analysi s amon g th e alternative s t o asses s th e relativ e performanc e o f

^ eac

h alternativ e wit h respec t t o eac h evaluation criterion

. i 5 2 Alternative s Evaluatio n Criteri a L
, Eac h o f th e retaine d alternative s wil l b e evaluate d agains t th e nin e evaluatio n criteri a detaile d below

. Additionally
, th e individua l alternative s wil l b e compare d wit h eac h othe r *•" t o ai d i n th e selectio n b y EP A o f th e preferre d alternativ e t o b e presente d i n th e propose d pla n an d ROD

. 52.1 Overal l Protectio n o f Huma n Healt h an d th e Environmen t
^ Thi s evaluatio n criterio n provide s a fina l check t o asses s whether eac h alternativ e provide s adequat e protectio n o f huma n healt h an d th e environmen t Th e overal l assessmen t o f protectio n draw s o n th e assessment s conducte d unde r other evaluatio n criteria , especiall y long-term effectivenes s an d permanence , short-ter m effectiveness
, an d complianc e wit h ARARS

. Evaluatio n o f th e overal l protectivenes s o f a n alternativ e durin g th e RI/F S shoul d focu s o n whethe r a specifi c alternativ e achieve s adequat e protectio n an d shoul d describ e ho w sit e risk s pose d throug h eac h pathwa y bein g addresse d b y th e F S ar e eliminated , reduce d o r MORRISO N KNUDSE N CORPORATIO N bb\18S3\FSWP.FN L 2 7 (D3/25/B4 Jcontrolle d

throug h treatment , engineerin g or institutiona l controls

. This evaluatio n als o allow s fo r consideratio n o f whether a n alternativ e pose s an y unacceptabl e short-ter m o r I cross-medi

a impacts

. L

52 2 Complianc e wit h ARAR s

— • A s a firs t step , a n introductio n wil l identif y th e concep t o f ARARs ; defin e applicabl e versu s relevan t an d appropriat e requirements ; presen t the NC P evaluatio n criteri a fo r relevanc e 

### L an d appropriateness ; presen t th e basi s fo r waivers ; an d describ e th e structur e (i.e.
, chemica l specific
, locatio n specific
, actio n specific ) i n whic h th e ARAR s wil l b e evaluated

. 

# L Th e secon d ste p i n th e ARAR s analysi s i s th e preparatio n o f a tabl e o r appendi x whic h j reiterate

s the univers e o f ARAR s considere d durin g the SFS

. Thos e requirement s tha t ar e determine d t o b e potentiall y ARAR s a t th e sit e ar e identifie d a s suc h an d retaine d fo r i furthe r evaluation

. Thos e requirement s tha t ar e no t potentia l ARAR s ar e identifie d an d fc

- a simpl e explanatio n o f the basi s fo r rejectio n i s provided

. Preparatio n o f the tabl e o r

, appendi

x efficientl y formalize s th e initia l selectio n an d ma y remov e numerou s requirement s L r fro m furthe r evaluation

.

! ^ Onc e th e potentia l ARAR s ar e identified
, th e chemical-specifi c ARAR s ar e evaluate d full y o n a media-specifi c basis

. I f a n exemptio n o r varianc e t o a chemica l specifi c regulatio n i s \ indicate d

o r i f a basi s fo r waive r exist s i t wil l b e develope d an d presented

.

, Th e locatio n an d actio n specifi c ARAR s retaine d followin g th e initia l screenin g ar e the n ^ * identifie d

i n a bulle t format
, o r alternatively , ar e define d briefl y i n a narrativ e forma t A t

, thi s juncture , th e reade r wil l b e directe d t o th e analysi s o f alternatives

. There
, th e actio n L

- or locatio n ARAR s tha t attac h t o eac h identifie d alternativ e wil l b e full y evaluated

. Th e logi c behin d thi s approac h i s straightforward

. I f ARAR s ar e "attached " t o technologie s ^ durin g th e screening , a numbe r o f locatio n an d actio n specifi c ARAR s analyse s woul d b e documente d fo r technologie s tha t wil l no t procee d t o remed y selection

. Reservin g an d • presentin

g th e locatio n an d actio n specifi c analyse s a s par t o f th e analysi s o f alternative s i s Ita M efficient

, an d allow s th e analysi s t o focu s upo n alternative s whic h ar e bette r defined

. Th e detaile d analysi s shoul d summariz e whic h requirement s ar e applicabl e o r relevan t an d appropriat e t o a n eac h alternativ e identifie d i n th e SF S an d describ e ho w th e alternativ e wil l attai n thes e requirement s durin g an d followin g th e selecte d remedia l action

. Th e F S report wil l rel y upo n th e NC P an d relevan t preambl e language

. MORRISO N KNUDSEN CORPORATIO N bb\1B83\FSWPJN L 2 8 (03/25/84 ]52. 3

Long-Ter m Effectivenes s an d Permanenc e U r f 

### Eac h o f th e thre e alternative s wil l b e assesse d fo r th e long-term effectivenes s an d | permanenc

e tha t ar e afforde d b y each , alon g wit h th e degree o f certaint y tha t th e alternativ e *" " wil l prov e successful

. Factor s tha t ar e considere d includ e th e following : i

- 1

.

Magnitud e o f residua l ris k remainin g fro m untreated wast e o r treatmen t residual s remainin g a t th e conclusio n o f th e remedia l activities

. Th e [

_ characteristic

s o f th e residual s shoul d b e considere d t o th e degre e tha t the y remai n hazardous , takin g int o accoun t thei r volume , toxicity , mobilit y an d i propensit

y t o bioaccumulate

. I 2

.

Adequac y an d reliabilit y o f control s suc h a s containmen t system s an d

w institutiona l

control s tha t ar e necessar y t o manag e treatmen t residual s an d untreate d waste

. Thi s facto r addresse s i n particula r th e uncertaintie s associated wit h th e assessmen t o f th e potentia l nee d t o replac e th e technica l component s o f th e alternativ e an d th e potentia l exposure pathway s an d risk s pose d shoul d th e remedia l actio n nee d replacement

. 5.2.4 Reductio n o f Toxicity
, Mobilit y o r Volum e Th e degre e t o whic h alternative s emplo y recyclin g o r treatmen t tha t reduce s toxicity , mobilit y o r volum e shal l b e assessed , includin g ho w treatmen t i s use d t o addres s th e principa l threat s pose d b y th e site

. Factor s tha t wil l b e considere d includ e th e following
, a s appropriate : 1

. Th e treatmen t o r recyclin g processe s tha t th e alternativ e employ s an d 

### material s the y wil l treat

. 2

. Th e amoun t o f hazardou s substances, pollutants , o r contaminant s tha t wil l b e destroyed , treated o r recycled

. 3

. Th e degree o f expecte d reductio n i n toxicity , mobility , o r volum e o f th e wast e du e t o treatmen t o r recyclin g an d th e specificatio n o f whic h reduction s ar e occurring

. 4

. Th e degre e t o whic h th e treatmen t i s irreversible

. MORR1SO N KNUDSE N CORPORATIO N tb\16B3\F8WPfNL 2 9 (03/25/W )i 5

.

Th e typ e an d quantit y o f residual s tha t wil l remai n followin g treatment , considerin g th e persistence , toxicity , mobilit y an d propensit y t o bioaccumulat e | o

f th e hazardou s substances

. !

_ 6

.

Th e degre e t o whic h treatmen t reduce s th e inheren t hazard s pose d b y an y *

- principa l

threat s a t th e site

. t L 5.2. 5 Short-Ter m Effectivenes s The short-ter m effectivenes s impact s o f the alternative s wil l b e assesse d considerin g the i following : t 1

.

Short-ter m risk s tha t migh t b e pose d t o th e communit y durin g implementatio n o f a n alternative

.

> - 2

.

Potentia l impact s o n worker s durin g remedia l actio n an d th e effectivenes s an d reliabilit y o f protectiv e measures
. 3

. Potentia l environmenta l impact s o f th e remedia l actio n an d th e effectivenes s an d reliabilit y o f mitigativ e measure s durin g implementation

. 4

. Tim e unti l protectio n i s achieved

. 5.2. 6 Implementabilit

y Th e eas e o r difficult y o f implementin g th e alternative s wil l b e assesse d b y considerin g th e followin g type s o f factor s a s appropriate : 1

. Technica l Feasibility
, includin g technica l difficultie s an d unknown s associate d wit h th e constructio n an d operatio n o f a technology , th e reliabilit y o f th e technology , th e eas e o f undertakin g additiona l remedia l action , an d th e abilit y t o monito r th e effectivenes s o f th e remedy

. 2

. Administrativ e

Feasibility
, includin g activitie s neede d t o coordinat e wit h othe r office s an d agencie s an d th e abilit y an d tim e require d t o obtai n an y necessar y approval s fro m othe r agencies

.

MORRISO N KNUDSE N CORPORATIO N bb\1CB3\FSWPJN L 3 0 103/25/94 ]

# L 3

.

Availabilit y o f service s an d materials , includin g th e availabilit y o f adequat e storage capacit y an d services , th e availabilit y o f necessar y equipmen t an d specialists , an d provision s fo r th e availabilit y o f service s an d materials , an d th e 

### availabilit y o f prospectiv e technologies

. 52.1 Cos t 

### Th e type s o f cost s tha t shal l b e assesse d includ e th e following : 1

. Capita l costs, includin g bot h direc t an d indirec t costs

. 

# L 2

.

Annua l operatio n an d maintenanc e costs

. 3

. Ne t presen t valu e o f capita l an d O& M costs

. V * 5.2.8 Stat e Acceptanc e Th e Stat e comment s an d concern s wil l b e addressed , a s appropriate , durin g th e developmen t L * o f th e FS

. Assessmen t o f CD H concern s wil l b e formall y presente d an d discussed i n th e propose d pla n issue d fo r publi c commen t Al l Stat e concern s wil l b e addresse d wit h special \ emphasi

s on : 1 ) Th e State' s positio n o n concern s relate d t o th e preferre d alternativ e an d othe r alternatives ; and , 2 ) th e State' s comment s o n ARAR s o r th e propose d us e o f waivers

. Communit y Acceptanc e Communit y concern s wil l b e take n int o accoun t throughout th e F S proces s throug h th e communication s tha t occu r a s th e communit y relation s pla n i s implemente d t o allo w fo r a preliminar y assessmen t o f communit y acceptance

. Forma l publi c comment s receive d durin g th e public commen t perio d fo r th e propose d pla n and th e F S repor t wil l also b e addressed

. 5 3 Presentatio n o f Individua l Alternative s Th e analysi s o f th e individua l alternative s wit h respec t t o th e specifie d criteri a wil l b e presente d i n th e Fina l FS

. Thi s informatio n wil l b e use d t o compar e th e alternative s an d suppor t analysi s fo r th e remed y selectio n process

. Th e narrativ e discussio n should , fo r eac h 

### alternative , provid e 1 ) a descriptio n o f th e alternativ e an d 2 ) a discussion o f th e individua l criteri a assessment

. 5. 4 Comparativ e Analysi s o f Alternative s
MORR1SO N KNUDSE N CORPORATIO N bb\1«S3\FSWPJN L 3 1 (03/25/84 ]^ Afte r th e alternative s hav e bee n describe d an d individuall y assesse d agains t th e criteria , a comparativ e analysi s shoul d b e conducte d t o evaluat e th e relativ e performanc e o f eac h alternativ e i n relatio n t o eac h specifi c evaluatio n criterion

. Thi s i s i n contras t t o th e precedin g analysi s i n whic h eac h alternativ e wa s analyze d independentl y withou t a I consideratio n

o f th e other alternatives

. Th e purpos e o f thi s comparativ e analysi s i s t o ^ identif y th e advantage s an d disadvantage s o f eac h alternativ e relativ e t o on e anothe r s o tha t th e ke y tradeoff s ca n b e identified

. 5. 5 Presentatio n o f Comparativ e Analysis ^ Th e comparativ e analysi s ma y includ e a narrativ e discussio n describin g th e strength s an d weaknesse s o f th e alternative s relativ e t o on e anothe r wit h respect t o eac h criterion , an d 1 ho w reasonabl e variation s o f ke y uncertaintie s coul d chang e th e expectation s o f thei r relativ e performance

. The presentatio n o f difference s amon g the thre e alternatives ma y b e measure d eithe r qualitativel y or quantitatively , an d wil l identif y substantiv e differences

.

; 5. 6 Cultura l Resource s Surve y an d Evaluatio n v D&RG

W wil l includ e i n th e Fina l Feasibilit y Stud y a cultura l resource s surve y whic h wil l b e patterne d afte r th e cultura l resourc e document s provide d b y ASARC O whic h wer e ^ conducte d

for th e sit e a s a whole

. D&RGW s cultural resource s surve y wil l b e specifi c t o th e area s i n whic h th e wor k wil l b e performed
, includin g th e A V sla g pile , th e Harriso n stree t sla g pile , th e L a Plat a Sla g pile , th e railyar d an d railroa d easemen t throug h town

. 

## L

MORRISO N

KNUOSEN CORPORATION bb\1<83\FSWRFM

. 3 2 103/25/04 ]

### [

_ 6. 0 SCHEDULE

; Th e origina l schedul e for th e F S wa s presente d a s par t o f th e overal l RI/F S schedul e i n th e h_

~ sla g pil e R I wor k pla n (MK
, 1991a)

. Tha t schedul e ha s bee n revise d base d o n change s i n i th e overal l sit e schedul e an d schedule s impose d b y th e Statemen t o f Work

. Th e followin g *

- summarize

s th e revise d EP A deliverabl e date s relativ e t o th e FS : I i

- •

Draf t F S Wor k Plan
, 3 0 Day s afte r signin g th e consen t decree , Januar y 14 , 1994

. ^ •

Fina l F S Wor k Plan
, thre e week s afte r receipt o f EP A comment s o n Draf t F S Wor k Plan

. I •

Draf t F S Report
, Augus t 1 , 1994

. • Fina l F S Report
, fou r week s afte r receip t o f EP A comment s o n Draf t F S Repor t

; The schedul e fo r the Fina l F S Wor k Pla n and the F S Repor t i s dependen t o n timel y receip t
^ o f pertinent dat a an d report s fro m others

.

MORRISO N KNUDSE N CORPORATIO N bb\18S3\FSWP^N L 3 3 (03/25/84 ]L 

### 7. 0 REFERENCE S | ASTM

, 1987

. Standard Practice fo r Sampling Aggregates, Designatio n D-75-87
, Annua l Boo k
o f AST M Standards
, Decembe r 1987

. t ^ CDL
, 1986a , Leadvilk/Stringtown Soils Investigation, Stat e o f Colorad o Department o f Law
, Prepare d b y Engineerin g Science
, Decembe r 1986

. 

### U CDL
, 1986b

. Ya k Turmel/CaUfomia Gulch Remedial Investigation, Stat e o f Colorad o ^ Department

o f Law
, Prepare d b y Engineerin g Science
, 1986

. I EPA
, 1993a , Consen t Decre e betwee n EP A an d th e D&RGW
, Entere d i n Cour t o n Decembe r 15,199 3

u EPA
, 1993b , Final Screening Feasibility Study fo r Remediation Alternatives a t th e California i Gulch Site, Leadvill e Colorado
, Septembe r 199 3 k

. EPA
, 1991a

. Administrative Order o n Consent fo r Remedial Investigation/Feasibility

Study L (Operable

Unit fo r Slag), CERCLA-92-06
, Decembe r 1991

. !

_ EPA
, 1990a

. National Oi l an d Hazardous Substances Pollution Contingency Plan, 5 5 F R 8848-51 , Marc h 8 , 1990

. EPA
, 1990b

. Data Tabulation Report fo r Sampling an d Analysis o f Major Slag Piles
- California Gulch, Leadville, Colorado, U.S

. EPA
, Prepare d b y Jacob s Engineerin g Group
, ^

- Inc.
, Februar y 1990

.

_ EPA
, 1990c

. Contract Laboratory Program Statement of Work for Inorganics Analysis,SOW4/90

. k M EPA
, 1990d

. Interpretive Report fo r th e Sampling an d Analysis o f th e Major Slag Piles
- California Gulch, Leadville, Colorado, U.S

. EPA
, Prepare d b y Jacob s Engineerin g Group
, Inc.
, September
, 1990

.

MORRISO N KNUDSE N CORPORATIO N bb\1883\FSWPAA

. 3 4 103/85/84 ]

## L

» L EPA
, 1989

. Draft Phase I I Remedial Investigation Technical Memorandum, 1986-1987, California Gulch Site, Leadville, Colorado, U.S

. EPA
, Prepare d b y CH2 M Hill
, Ma y 1989

. i
^ EPA

, 1989a

. CERCL A Complianc e wit h othe r Law s Manual
, OSWE R Directiv e 9234.1-0 1

*

- EPA
, 1988b

. Guidance fo r Conducting Remedial Investigations an d Feasibility Studies Under CERCLA, Interi m Final
, EPA/540/G-89/00 4

U.S

. EP A Offic e o f Emergenc y and Remedia l L Response
,

Washington
, D.C.
, Octobe r 1988

. I Medine
,

1993

. Conceptua l Mode l an d th e Development o f a Contaminan t Transpor t Mode l fo r Metal s i n Californi a Gulch
, Draf t Technica l Memorandum
, Alie n J

. Medine
, 1 Wate r Science
, Januar y 1994

. MK
, 1992

. Final Report fo r Lead Slag Pile Remedial Investigation a t th e California Gulch

^ Site, Leadville
, Colorado
, prepare d b y Morrison Kmidse n Corporatio n fo r Denve r an d Ri o Grand e Wester n Railroa d Company
, Decembe r 1992

. i MK
, 1991a

. Work Plan fo r Slag Pile Remedial Investigation a t California Gulch Site, Leadville,

^ Colorado,

Prepare d b y Morriso n Knudse n Corporatio n fo r Denve r an d Ri o Grand e Wester n Railroa d Company
, Octobe r 1991

. i L

. MK
, 1991b

. Sampling an d Analysis Plan fo r Slag Pile Remedial Investigation a t California Gulch Site, Leadville, Colorado, Prepare d b y Morrison Knudse n Corporatio n fo r Denve r an d

u Ri o Grand e Wester n Railroa d Company
, Novembe r 1991

.

^

- Res-ASARCO

, 1991

. Draft Remedial Investigation Scoping Document California Gulch Site, Leadville, Colorado, Prepare d b y Woodward-Clyd e Consultants
, Apri l 1991

. w . Resurrection

, 1992

. Final Work Plan
- Metal Speciation an d Source Characterization, California Gulch CERCLA Site, Leadville, Colorado. Prepare d b y Cam p Dresse r an d McKe e fo r Resurrectio n Minin g Company
, Januar y 20,1992

. i * * Walsh
, 1988

. Draft Soil Investigations i n th e Leadville Study Area, Lake County, Colorado. Prepare d b y Jame s P

. Wals h an d Associate s fo r Bradley
, Campbel l an d Carney
, Marc h 1988

.

MORRISO N KNUDSE N CORPORATIO N bb\18S3\FSWP.FNl

. 3 5 [03/29/84 ]Ifebl e 4- 1 Evaluatio n o f Proces s Option s fo r Slag ; Pile s CiENERA L RESPONS E ACTIO N N O ACTIO N INSTITUTIONA L 

### CONTROL S

CONTAINMEN T

Containmen t (Cent ) REMEDIA L PROCES

S TECHNOLOC T OPTIO N Non e - Non e Lan d Us e Zoning
,

Dee d fesliklion s

Acces s Restriction s Fencin g an o f > < t _ *
, j rosie a iVaniing s Communit y Awarenes s Surfac e Wate r Diversio

n Control s Ditche

s Channelizatio n Sourc e Surfac e Revegetatfo n Control s Simpl

e Cove r Mufti-Laye r Cove r EFFECTIVENES

S

WL|

_ A ^i »

_ _M« U

Jt W nothin g t o reduc e th e toxicity t rocoflit y o r volum e 0 1 contaminant s Effectiv e i n limitin g th e potentia l fo r direc t huma n an d som e anima l contac t wit h contaminate d materials

. Wil l not provid e protectio n o f th e environmen t fro m an y

• •(•AtM M
— — - _ *
——— — *
— — * » —— — existin g contamination

. Effectiv e i n limitin g direc t contac t wit h contaminate d material s

YIFnaafl t Mn d ••ifuii M invlnll M t\ m th e volum e o f contaminants ! surfac e wate r ru n o n t o pile s i s minimal * Diversio n o f surfac e wate r flo w throug h sourc e i s no t Effectiv e a t reducin g infittfanoft f ef0&k> A an d visua l impact s Effectiv e i n minimizin g th e vertica l transpor t o f !_*!* ! A^«J« « ••«•• • nnsis i •t«* 4 re d ac e ro e tcwdcn y o r volum e o f contaminants

. Mos t effectiv e comple x typ e o f ca p i n minimizin g vertica l transpor t o f infiltratin g «•*** • * *
—— — wmAntm »f*mMt* IMTLEMENTABILn T

RELATIV E RETAI N COST * Hig h Hig h

Hig h Hig h Hig h Hig h Hig h Hig h

Mediu m Non e

Yes
, fo r cos t compariso n Low Ye s

Lo w Capita l Ye s LowO& M Lowcos t Ye s LowO& M Lo w Capita l N o LowOA M
Mediu m N o Capita l Mediu m Oft M Lo w Capita l Ye s LowO& M Lo w Capita l Ye s LowOft M Hig h Capita l Ye s LowOft M

o r volam e o f contaminants

.
09C423Z7/R41T.10 4 09^»W(W7iffl)/RPT/1 7 Shee t 1 o f 3

## r~~. - r : i

— r,~. r Tfebf e 4* 1 Bvfthiatio n o f Proces s Option s fo r Sta g Pile s 

## r

~ GENERA L RESPONS E ACTIO N

Removal
, Transport i Disposal

treatmen t REMEDIA

L PROCES

S TECnNOLOG Y OPTIO N Surfac e Darnci s Retainin g Structure s
Dams/Trap s

Remova l Mechanica

l Bxcavation/Dr e Transpor t Truck/Rai l Haulin g Disposa l Oil-cit

e Repositor y On-Sit e Consolidatio n Physical/Chemica l Physical Separatio n Neutralizatio n EFFECTIVENES

S Effectiv e i n preventin g slidin g an d erosio n o f slopes whe n use d i n conjunctio n wit h capping * Doe s no t reduc e contaminan t loxicit y o r volume * Effectiv e i n reducin g migratio n o f runof f t o surfac e waterways

. Doe s no t reduc e toxkit y o r trappe d cotid s mus t b e treated

. Effectiv e mean s o f removin g materia l Effectiv e fo r movin g material Effectiv e i n reducin g exposur e ijsiiiway s dependin g o n th e engineerin g control s a t th e repositor y Effectiv e i n reducin g exposur e paiiiway s an o numbe r o f sla g piles

. Effectiv e i n sizin g th e na g particles

. Ma y no t reduc e levels *

A 4i<fltln M ns t tt^+m m •Mili l •** * b e effectiv e a t neutralizin g sla g becaus e o f hig h intrinsi c •*»•• ! ••!••• * I f M i MHMM*ft W IMPLEMENTABIUI

Y Hig h
Hig h
Hig h Hig h Medium
, Woul d reouir c pennmin g o r landfil l Hig h Hig h
Lo w RELATIV

E COST * Hig h Capita l LowO& M

Mediu m Capita l Mediu m OA M
Mediu m
Mediu m Mediu m Capita l Mediu m OA M Mediu m LowO& M Mediu m Capita l Mediu m Oft M Hig h Capita l Mediu m Oft M RETAI N N o
Yes

Yes Yes N o Yes
Yes N o

increase s volum e o f material *

2W09042327/R41T.10 4 Shee t 2 o f 3

## r r ~ r ~ r ~ \

— r r r ~ r i

— r ~ r r — r : r Tabl e 4- 1 Evaluatio n o f Proces s Option s for Sla g Piles_________

_

_____ __________^___

_ GENERA L RESPONS E REMEDIA L PROCES

S EFFECTIVENES

S IMPLEMENTABI1JI

Y RELATIV E RETAI N ACTION_________TECHNOLOG

Y OPTION____________________________________COST*___________

_ Resourc e Utilizatio n Resourc e Utilizatio n Ballast Effectiv e

i n sourc e remova l Hig h Mediu m

Ye s Prodnctlon
, us e Capita l a s additive s i n Lo w O& M construction materials , stan d alon e constructio n material s

22909C-22327/R41T.10 4

09-28-93(937MB)/RPT/I

7 Shee t 3 o f 3

## r r r~ r r Tabl e 4* 2 Screenin g o f Remedia l Alternatives

. REMEDIA L ALTERNATIVE

S & PRIMAR Y COMPONENT S 1 ) N o actio n 2 ) Institutiona l Control s

3 ) Sourc e Surfac e Controls/Institutiona l Control s 4 ) Surfac e Water/itaffieii/Institut i ona l Control s 5 ) Removal/Iranspoit / Disposal/Institutiona l Control s 6 ) Resourc e Utilizatio n -Railroa d Ballas t • Additiv e materia l fo r constructio n Undersize d materia l a s additiv e materia l i n constructio n DESCRIPTIO

N O F PROCES S N o actio n Combinatio n o f on e o r mor e o f th e following ? Fencing i f*

~ ~ * l*^ ^ •>

— IjiAlj^

— — i/ee a Kcsinctions
, an d Us e Restrictions ! Monitoring
, Manag e men t Practice s Cove r pile s wit h soil/clay / muture , revegetat e Diversio n Ditche s Remova l o f pile s fo r consolidatio n on-sit e o r on-cit e repositor y Sort/cfus h nag , obtai n greate r tha n 3/8 * bu t les s tha n 2 1/2 * fo r railroa d ballas t EFFECTIVENES S Unknow n Unknow n

Margina l reduction i n infiltratio n Surfac e wate r run-o n onl y importan t a t certai n piles , effectivenes s unknow n Dependin g upo n characteristic s o f repositor y ari d engineerin g control s leachin g ma y no t b e minimized Source Remova l ofrait e o r usag e withi n th e sit e IMPLEMENTABIUT f Imptementabt e Conventional procedure s

Medium
, Pfl s non-uniformity
, woul d lea d t o larg e quantities 0 1 soil/na y cove r material , Medium
, Conventiona l technology , diversio n ditches ma y b e difficul t du e t o surface/groun d wate r interaction s

ar e al l problems associate d wit h hnpkmcntabflH y High
, conventiona l technolog y fo r ballas t COS

T Non e Lo w t o moderate * dependin g o n material s an d O« M cost s

AVediu m cos t Lo w Implementatio n an d O A M cos t Hig h Cos t Lo w Cos t FINA

L DISPOSITIO N

n^tmlm^Jt tvctaine Q f t •talm a i t j\cnmie o

No t Retaine d No t Retained No t Retaine d Retaine d

22909C22927/R41T.10 5

09^8-93(9-J8««)/RPT/1 7 Shee t 1 o f 2r Figur e U 

## p...

. r 

# Organizatio n Char t 

# D&RG

W Projec t Coordinato r 

### Kathy Snead

M K Projec t Manage r 

### Doug Uhfand 

## Outsid

e Gbunfie l

### J 1 J J j J J J J LEGEN D b HISTORI

C suar a LOCATIO N ? b HISTORI

C SHELTE R LOCATIO N • TENTATH *

— —-^Rl/rSSJt C BOUNDAR Y

VolUy S ioPi «

CALIFORNI A GULC H CCRCL A SIT E SLA G PIL E REMEDIA L INVESTIGATIO N SIT E MA P WIT H LEA D SU G PIL E LOCATION S DENVE R I t RI O CRAND C WESTER N RAILROA D DENVER

. C04.0RAO O UORRISOM-KNUOSC N CORPORATIO N TOPOGRAPHI C CONTOUR S AN D SURFAC E FEATURE S «£ £ inniC

I IUH U I H W I MMWtHUM

i ?> I >« M I U O M Flgu«»2. 1

### u L 

# L
L

t'


### L Responsivenes s Summar y 

### Californi a Gulc h Feasibilit y Stud y Wor k Plan^ Responsivenes s Summar y Californi a Gulc h Feasibilit y Stud y Wor k Pla n i * " GENERA

L COMMENTS :

! L 1 ) Th e documen t contain s detai l regardin g previou s wor k performe d a t th e site, howeve r i t i s brie f o n projec t team , schedul e an d propose d work

. Th e projec t tea m ; an

d schedul e nee d mor e detai l an d th e propose d wor k need s t o b e mor e specifi c a s U t

o ho w th e pla n wil l b e applie d t o Californi a Gulch

. ; Response :

Th e Fina l Draf t F S Wor k Plan ha s bee n revise d t o addres s thi s commen t 

### L 2 ) Sectio n 5 2 coul d b e shortene d considerabl y b y listin g th e nin e criteri a i n a tabl e wit h ! a

brie f descriptio n o f wha t eac h criterio n includes

. Response : Sectio n 5. 2 i s important t o th e F S wor k pla n becaus e o f th e criteri a liste d an d • th e evaluatio n o f th e alternative s versu s th e criteria

. L

. 3 ) Man y acronym s ar e no t define d upo n thei r firs t appearanc e i n th e tex t Thes e ! includ

e PRPs
, D&RGW
, CERCLA
, NCP
, ARARs
, CLP
, RCRA

. k * ( Response :

A lis t o f acronym s wil l b e presente d i n th e wor k plan

. 4 u 4 ) Th e documen t contain s numerou s discrepancie s betwee n cite d reference s an d thos e

, liste d

i n Sectio n 7.0

. Mos t noticeabl e i s th e absenc e o f an y specifi c citatio n o f th e l

_ Screenin

g Feasibilit y Stud y (SFS)

. Response : Specifi c citation s fro m th e Screenin g Feasibilit y Stud y wil l b e included , wher e j_ , appropriate

.

Othe r instances , i f any , wher e discrepancie s betwee n cite d reference s an d th e referenc e lis t wil l b e addressed

. j

_ 5 ) I t i s unclea r whether Sectio n 4. 0 i s entirel y a summar y o f th e SFS
, o r incorporate s som e aspect s o f subsequen t alternative s screening

. Th e summar y Table s 4- 1 an d 4- 2 I ar

e als o inconsisten t i n thei r discussio n o f variou s proces s options

. u Response :

Sectio n 4. 0 summarize s th e result s o f th e SF S an d doe s no t incorporat e an y ! additiona l

alterativ e screening

. Th e Table s wer e directl y take n fro m th e SFS
, whic h i s a n U EP A document , release d i n 1993

. i 6 ) Th e SF S addresse s al l sla g size s whil e th e draf t F S Wor k Plan fo r Stockpile d Fin e L Sla

g addresse s fine-size d fractio n material

. Accordin g t o th e RI
, leachin g fro m fin e sla g wa s retaine d a s a pathwa y o f exposur e an d shoul d b e addresse d i n th e FS

. | Sourc e

surfac e control s ar e describe d i n Tabl e 4- 1 a s bein g effectiv e a t reducin g i

- infiltratio n

an d vertica l transport

.i ^ Response :

Thos e alternative s remainin g fro m th e SF S ar e t o b e examine d i n th e FS

. Thi s approac h i s documente d i n th e Consen t Decre e betwee n EP A an d D&RG W o f Decembe r 

### i 15,1993

.

Othe r alternative s whic h wer e screene d ou t i n th e SF S wil l no t b e reconsidered L i n th e FS

. 8 ) Sectio n 5. 0 provid e n o informatio n a s t o ho w th e detaile d analysi s o f alternative s wil l

_ proceed

. Th e section present s a pla n fo r guidin g wor k fo r th e fina l FS
, bu t i t i s no t clea r bo w thi s pla n wil l b e applie d t o th e Californi a Gulc h sla g pile s fo r whic h Denve r an d Ri o Grand e Wester n (D&RGW)

. Th e F S shoul d includ e som e i

_ quantitativ e

o r semiquantitativ e estimate s o f th e reductio n o f leachat e generatio n resultin g fro m th e proces s option s considered

. i i U

. Response :

Th e F S wil l includ e a quantitativ e o r semiquantitativ e assessmen t o f leachat e generate d fro m th e stockpile d fine s a s th e bas e cas e (n o actio n alternative)

. Th e 1 comparison

o f othe r remedia l alternative s agains t th e n o actio n alternativ e wil l b e *• * documente d

i n th e FS

. Th e F S wor k pla n shoul d not , an d doe s not , provid e thi s assessment , rathe r th e approac h t o th e assessmen t i s defined

. Mor e detai l a s t o th e approac h ha s bee n i adde d t o th e F S Wor k Plan i n Sectio n 5.0

. Generally
, th e approac h i s t o calculat e th e mas s *• * loadin g o f metal s o f concer n fro m stockpile d fin e sla g plie s a t th e A V Sla g Pil e an d usin g appropriat e geochemica l transpor t models , estimat e th e mas s loadin g t o th e Californi a 

### i Gulch

. Estimate s o f mas s o f metal s teachabl e fro m Colum n Leac h an d othe r studie s *" • conducte d

durin g th e R I d o no t conside r an y retardatio n mechanism s whic h activel y inhibi t ) the transpor t o f metal s t o the Californi a Gulch

. Additionally
, the groun d water/surfac e i wate r interaction s nee d t o b e furthe r examine d becaus e i t appear s a s i f th e Gulc h i s a losin g u strea m i n th e vicinit y o f th e AV

. i SPECIFI

C COMMENT S

^ Pag e ii

. Th e Tabl e and Figur e reference s shoul d agre e wit h th e Tabl e and Figur e Titles

. Specifically
, th e Table s ar e title d 4- 1 an d 4- 1 (rathe r tha n 4. 1 an d 4.2)
, an d th e Figure s ar e I title d 1. 1 an d 1- 1 (rather tha n 1. 1 an d 1.2)

. Th e secon d figur e shoul d i n fac t b e Figur e 2.1

. 

### L Response :

Figur e numbe r 1- 1 wil l b e change d t o b e Figur e 2.1

. L

. Pag e 1 , Paragrap h 1 , lin e 6

. "M K 1992 " shoul d b e enclose d i n parentheses

. i Response :

Th e revise d F S Wor k Pla n wil l reflec t thi s change

. 

# u Pag e 1 , Para

. 1 , Line s 6-7

. Provid e a referenc e fo r th e Screenin g Feasibilit y Study

. L

. Response :

Th e SF S wil l b e reference d i n Sectio n 7.0

. i Pag e 2 , Para

. 4 , lin e 3

. Th e capitalizatio n o f "propose d plan " an d "Recor d o f Decision " i s » ~ no t consisten t throughou t th e document

.[ ^ Response :

Th e revise d F S Wor k Plan wil l reflec t thi s change

. ; Page 3,.Para

. 2 , bulle t three

. Th e technica l revie w committe e shoul d b e show n o n L Figur e 1. 1
1 Response :

Th e figur e i s intende d t o presen t th e D&RG W organizatio n an d no t necessaril y L al l o f th e interaction s wit h governmen t an d loca l group s intereste d i n th e Californi a Gulc h site

. i

— Pag e 3 , Sectio n 1.2

. Ther e ar e eigh t positions/individual

s show n o n th e organization char t (Figur e 1.1.)
, ye t onl y on e i s describe d i n th e tex t Eithe r simplif y th e organizatio n chart , 

## L o r a t least briefl y describ e responsibilitie s an d dutie s o f th e othe r positions

. Unde r "othe r responsibilities , a s necessary, " pleas e add : "State
, an d sit e activitie s Coordinatin g Committe e (SACC) " t o th e las t bulle t an d ad d a n additiona l bulle t addressin g communit y relation s I activities

. L » Response :

Th e othe r committee s wil l b e adde d t o th e tex t i * • Page s 4-7 , Sec

. 2.1

. Eac h o f th e subheading s shoul d b e numbered , e.g. , 2.1. 1 Climatolog y I Response :

Th e sectio n number s wil l b e added

. ( Pag e 4 , Para

. 1 , lin e 2

. Th e wor d "physiologic " shoul d probabl y b e replace d b y ! "physiographic" ;

"physiologi c refer s t o th e functionin g o f a livin g creature

. L- r Response :

Physiographi c wil l replac e physiologic

. Page 4 , Sec

. 2.1 , Para

. 1 , lin e 5

. I t i s unlikel y tha t place r method s wer e use d t o min e majo r sulfide/carbonat e or e deposits

. Clarif y thi s statement Response : Place r minin g wa s a majo r activit y i n th e earl y histor y o f Leadvill e mining

. i |

_ Pag e 4 , Sec

. 2. 1 Para

. 3 , lin e 3

. Substitut e "concentrations " fo r "proportions"

. j Response :

Th e substitutio n wil l b e mad e i n th e Draf t Fina l F S Wor k Plan

. L

. Pag e 5 , Para

. 1 , lin e 8

. Th e referenc e t o "CDL

. 1986 " shoul d b e eithe r 1986 a o r 1986b

. i L

. Response :

The correc t referenc e appear s i n the Draf t Fina l F S Wor k Plan

. j Page 5 , Para

. 4 , Lin e 1

. Th e Pender y Faul t shoul d b e show n o n a figure

. L 

### Response :

Th e Pender y Faul t ha s bee n adde d t o th e Figure

. On e shoul d b e cautiou s tha t i th e Pender y Fault' s locatio n i s approximate

. 

### L Page 5 , Para

. 4 Line s 3 an d 4

. Th e wor d "Fault " shoul d b e lowe r cas e unles s i t i s par t o f[ ^ a forma l nam e o r th e "th e Fault " shoul d b e referenced

. ! Response :

Commen t Note d L Pag e 5 , Para

. 4 , lin e 6

. Substitut e "uppe r Californi a Gulch... " fo r "upper Gulc h itsel f 1

_ Response :

Th e suggestio n ha s bee n incorporate d i n th e Draf t Fina l F S Wor k Plan

.
: Pag e 7 , Para

. 1 , lin e 3

. I f th e quotation i s fro m EPA
, 1989 , th e quote s shoul d preced e th e L

- parenthetica l

expression

. I f the parenthetica l i s par t o f the quotation, the n a referenc e fo r th e quotatio n shoul d b e provided

. i i

- Response :

Th e quotatio n mark s hav e bee n relocated

. Th e quot e i s fro m EPA
, 1989

. i Pag e 7 , Para

. 1 , sentenc e 2

. Wha t i s th e explanatio n fo r highes t meta l concentratio n durin g ^

- th e tim e perio d whe n surfac e wate r flo w i s highest ? I s th e meta l presen t a s dissolve d o r suspende d constituents

. i
^ Response :

Typicall y meta l concentrations , bot h dissolve d an d suspended , ar e highes t i n th e sprin g (May/June)

. Thes e hig h concentration s ar e probabl y du e t o influ x o f runof f induce d 1 particulate s

fro m variou s sourc e areas
. Pag e 7

. Para

. 1 , lin e 6

. Th e wor d "Aquatic " shoul d probabl y b e change d t o "Ambient. " i
^ Response :

Aquati c wil l b e change d t o Ambien t i n th e Draf t F S Wor k Plan

. j ^ Pag e 7 , Sec

. 22 , Par a 1 , lin e 1

. Sla g i s mor e likel y a metalliferou s by-product rathe r tha n mineralized

. I f mineralized , wha t ar e th e minerals ? \ [ Response :

Metalliferou s i s a bette r ter m an d wil l b e include d i n th e Draf t Fina l F S Wor k Plan

. * j ^ Pag e 7 , Sec t 2.2 , Para

. 2 , Lin e 1

. Silico n i s no t a metal

. | Response :

Metalli c element s i n genera l ar e distinguishe d fro m th e non-metalli c element s L b y thei r lustre , malleability , conductivit y an d usua l abilit y t o for m positiv e ions

. Whil e silico n i s no t particularl y malleable , th e othe r definition s ar e tru e fo r silicon

. Becaus e i t i s i i n th e sam e ro w o n th e periodi c tabl e a s germanium , ti n an d lead , silico n i s ofte n referre d L

. t o a s a metal

. j Pag e 8 , Para

. 2 , lin e 1

. Provid e a referenc e citatio n fo r th e Sla g Pil e Remedia l L Investigation

. | Response :

Th e Sla g Pil e R I i s reference d a s MK
, 1992

. Pag e 8 , Sec

. 23 , Para

. 1 , line s 1-5

. Thi s discussio n i s essentiall y redundan t t o Sec

. 22

.^ Conside r

combinin g thes e tw o sections

. 

### { Response :

Commen t Noted

. U Pag e 8 , Sec

. 23 , Para

. 1 lin e 1

. Delet e th e wor d "activity"

. L Response :

Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n revised

. Pag e 8 , Se c 23 , Para

. 1 , lin e 5

. Th e referenc e shoul d b e t o Figur e 2.1 , no t 2-1 , o r th e •

— captio n o f Figur e 1.1

. shoul d b e revised

. ! • Response : Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n revised

. i

- Pag e 8 , Sec

. 23 , Para

. 1 , lin e 7

. Provid e a referenc e citatio n fo r th e D&RG W sla g pil e RI

. i Substitut

e "slag " fo r "pile, " o r inser t "slag " befor e "pile"

. Response : The tex t o f the Draf t Fina l F S Wor k Plan ha s bee n revised

.
^ Pag e 9 , Para

. 2 , last sentence

. Describ e ho w lon g th e pil e is , o r ho w man y fee t i s 1/ 5 o f th e pil e length

.
u Response :

The tex t o f the Draf t Fina l F S Wor k Plan ha s bee n revised

.
» Pag e 9 , Para

. 3

. Describ e th e relativ e proportio n o f ai r quenche d t o wate r quenche d sla g i n th e pile

. Describ e th e area l exten t o f th e pile

. i Response :

Th e tex t o f th e Draf t Fina l F S Wor k Pla n ha s bee n revised

. Ah * quenche d (sorte d fines ) currentl y consis t o f abou t 1/ 3 th e volum e o f th e wate r quenche d fines

. Th e area l exten t o f th e A V pil e i s describe d i n th e Sla g R I report , M K 1992

. Pag e 9 , Sectio n 232, lin e 6

. I t i s no t clea r i f "Bimetalli c smelte r slag.. " i s referrin g t o sla g ; fro m th e Bimetalli c Smelter
, o r smelte r sla g fro m bimetallic concentrates

. I f th e former
, b e L
, consisten t o n capitalization

. I f th e former
, ho w doe s i t relat e t o th e Berdel l an d Witheral l Smelter
, o r the L a Plat a Sla g Pile

. i L
, Response :

Th e L a Plat a sla g pil e i s th e resul t o f smeltin g operation s for tw o metals , lea d an d silve r (bimetallic)

. Berdel l an d Witheral l wa s th e origina l nam e o f th e smelte r prio r t o ! th e nam e changin g t o th e L a Plat a Smelter

. A t on e tim e th e L a Plat a smelte r wa s name d L

. th e Bimetallli c smelter

. L a Plat a i s th e curren t nam e an d th e last nam e fo r th e smelte r 

### operations

. 1

~ Pag e 9 , Sec

. 23.2 , last line

. Provid e a referenc e citatio n fo r th e sourc e o f surve y information

.
» - Response :

Al l surve y informatio n wa s either derive d fro m 1 ) physica l survey s a t th e sit e durin g th e R I o r 2 ) fro m aeria l photographs

. Al l informatio n relativ e t o surveyin g i s 

# L

### ^ presente d

i n th e R I report

. j Pag e 10 , Para

. 1 , lin e 1

. Substitut e "...

. L a Plat a (LP)... " fo r "...L a Plata..."

. t Response :

The tex t o f the Draf t Fina l F S Wor k Plan ha s bee n revised

.

_ _ Pag e 10 , Para

. 2 , lin e 1

. Substitute " Th e L P Pil e . " fo r "Th e L a Plat a (LP ) Piles..."

. This wor k pla n need s mor e consisten t definitio n an d us e o f acronyms
. L

- Response :

Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n revised

. | Pag e 10 , Para

. 2

. Describ e th e area l exten t o f th e pile

. L

. Response :

Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n revised

. 

### i 1 * Pag e 10 , Se c 233 , Par

. 1 an d 2

. I s th e Harriso n Stree t (HR ) pil e th e sam e a s th e Harriso n Sla g pile ? I f so , b e consisten t wit h nomenclature

. I s H R th e prope r acronym ? I
^ * Response :

Th e Harriso n Stree t (HR ) pil e i s th e sam e a s th e Harriso n Sla g pile

. HRisth e prope r acronym . The tex t o f the Draf t Fina l F S Wor k Pla n ha s bee n revised

. 

### *• * Pag e 10 , Sec

. 233 , Para

. 2 , Describ e th e area l exten t o f thi s pile

. Response :

The Draf t F S Wor k Plan ha s bee n modifie d t o detai l thi s requeste d information

. Pag e 11 , Para

. 1 , lin e 2

. Th e referenc e shoul d b e t o Figur e 2.1 , no t 2-1 , o r th e captio n o f i Figur e 1. 1 shoul d b e revised

.



### , Response :

Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n revised

. Pag e 11 , Para

. 1

. Ha s thi s pil e bee n surveyed ? I f so , describ e th e estimate d tonnage an d ; area l exten t 

## L Response :

The tex t o f the Draf t Fina l F S Wor k Plan ha s bee n revised

. i L

_ Pag e 11 , Para

. 2 , lin e 4

. Describ e t o wha t th e sla g pile s ar e adjacent

. I t th e inten t t o sa y the y ar e adjacen t t o eac h other ? L Response :

Th e pile s ar e adjacen t t o eac h other

. ; Pag e 11 , Para

. 2

. Hav e thes e sla g pile s bee n surveyed ? I f so , describ e th e estimate d L

. tonnag e an d area l exten t o f th e piles

. i Response :

Al l o f thi s informatio n wa s presente d i n th e Sla g Pil e RI
, NI K 1992

. Th e Draf t *•

- Fina l F S Wor k Plan wil l b e revise d t o describ e th e informatio n requested

.^ Pag e 12 , Para

. 1 , firs t sentence

. Delet e ".

. i n th e Californi a Gulch. " j Response :

Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n revised

. L

. Pag e 12 , Sec

. 32 , Para

. 2 , lin e 3

. Inser t "at " followin g "interval. "

4 L

_ Response :

The tex t o f the Draf t Fina l F S Wor k Plan ha s bee n revised

. Pag e 12 , Sec

. 32 , Para

. 3 , lin e 6-7

. Defin e th e concentratio n level s represente d b y "highes t L

. concentrations"

, an d "highes t levels. " • Response :

Th e ter m highest i s relativ e t o al l medi a a t th e Californi a Gulc h Superfun d Site

. L Pag e 14 , Para

. 2 , lin e 1

. A referenc e shoul d b e provide d fo r th e stud y b y Jacob s j Engineering;

i t i s probabl y EP A 1990b

. 

### L < Response :

Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n revised

. i ^

- Pag e 14 , Para

. 2

. Pleas e clarif y whethe r fou r samples wer e collecte d a t eac h sla g pile , o r fou r samples wer e collecte d total

.
^ Response :

Generally
, fou r samples wer e collecte d fro m eac h pile

. The tex t o f the Draf t Fina l F S Wor k Plan ha s bee n revised

.

u Pag e 15 , Para

. 1 , las t sentence

. Substitut e "...containe d 5 an d 1 5 weigh t percen t fin e

, material

, respectively. " fo r "...showe d 5 an d 1 5 percent , respectively. " Response : The tex t o f the Draf t Fina l F S Wor k Plan ha s bee n revised

. Pag e 16 , Para

. 1 , lin e 1

. Th e wor d compositiona l need s a n adver b t o describ e wha t kin d o f • compositio n

i s bein g referre d to

. I f chemical , the n stat e it

. 

### r Response :

The tex t o f the Draf t Fina l F S Wor k Plan ha s bee n I revised

. L Pag e 16 , Sec

. 3.5.2 , Par a 2

. Doe s th e ter m "registere d lan d surveyor " refe r t o "license d i surveyor"

. 

### u Response :

Registere d Lan d Surveyo r i s th e correc t term

. I i

- Pag e 16 , Sec

. 35.2 , Para

. 3 , lin e 4

. Describ e wha t percen t o f th e gri d wa s selecte d randoml y for sampling , and ho w man y sample s wer e collecte d pe r sla g pile

. i i

~ Response :

Th e inten t o f th e F S i s t o provid e a backgroun d an d indicat e th e directio n an d scop e o f wor k i n th e FS

. Th e reviewe r i s referre d t o th e Sla g R I report s o r th e Samplin gt I 

### u

and Analysi s pla n for mor e detail

. 

### Pag e 16 , Sec

. 35.2, Para

. 3 , lin e 10

. Expan d th e discussion o f th e proces s use d t o determine a representativ e weight

. Wha t procedure s wer e use d t o ensur e tha t th e samplin g proces s di d no t bia s th e sample ? L Response :

Th e inten t o f th e F S i s t o provid e a backgroun d an d indicat e th e directio n an d scop e o f wor k i n th e FS

. Th e reviewe r i s referre d t o th e Sla g R I report s o r th e Samplin g and Analysi s pla n fo r mor e detail

. 

### L Pag e 16 , Sec

. 3.5.2 , Para

. 3 , lin e 13

. Defin e "ol d Slag. " i : L Response :

Ol d sla g i s a ter m o f ar t coine d b y th e EPA

. D&RG W doe s no t understan d wha t th e ter m ol d sla g refers

. Additionally
, statistica l evaluation s o f chemica l composition s 

### i o f al l sla g sample s d o no t indicat e tha t ther e woul d b e a basi s fo r th e us e o f suc h a term

. Pag e 17 , Para

. 2 line s 1 an d 4

. Th e wor d "compositional " need s a modifie r t o describ e wha t typ e o f compositio n i s bein g referre d to

. ^ Response :

The tex t o f the Draf t Fina l F S Wor k Plan ha s bee n revised

. i ** • Pag e 17 , Sec

. 3.5.3 , para

. 2 , 1s t sentence

. Thi s i s th e firs t plac e tha t CL P ha s bee n define d a s a n acronym , althoug h th e acrony m ha s alread y bee n use d severa l times

.

u Response :

Th e tex t o f th e Draf t Fina l F S Wor k Pla n ha s bee n revised

. i * " Pag e 17 , Sec

. 3.5.3 , para

. 2 , line s 2-3

. A referenc e shoul d b e provide d fo r th e Burea u Mine s sampl e digestio n method

. Response : Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n I revised

. Pag e 17 , Sec

. 3 53 , Para

. 2 , lin e 3

. Th e acrony m TA L ha s previousl y bee n defined
, i t doe s ; no t nee d t o b e define d again

. Response : Th e tex t o f th e Draf t Fina l F S Wor k Pla n ha s bee n revised

. 

### Pag e 17 , Sec

. 3.53 , Para

. 3

. Wha t ar e th e result s o f th e leachin g tests ? Ho w d o th e result s contribut e o r impac t thi s wor k plan ? Response : Th e result s o f th e leachin g test s wer e provide d i n detai l i n th e Lea d Sla g R I report

. The result s impac t the Feasibilit y stud y i n tha t the amoun t o f metal s potentiall y leache d fro m th e fin e sla g provide s th e baselin e fro m whic h t o judg e th e effec t o f an y contemplate d remedia l actions

.Pag

e 18 , Sec

. 35.4 , Para

. 3,1s t sentence

. Stat e th e constituent s o f concern . Wha t quantitie s o f metal s wer e leache d pe r uni t mas s o r volume

. Response : Th e primar y constituen t o f concer n i s lead

. Th e quantitie s o f metal s leache d wer e presente d i n th e Lea d Sla g R I report

. Th e quantitie s o f metal s liberate d durin g th e leachin g test s ar e considered overestimate s o f leachin g potentia l becaus e o f th e wa y th e test s wer e conducted

. Th e mas s o f metal s leache d ar e t o b e compare d t o th e mas s introduce d t o Californi a Gulc h fro m al l source s takin g int o accoun t th e variou s retardatio n mechanism s i n th e transport t o surfac e wate r calculation s i n th e FS

. Compariso n o f th e bas e cas e wit h th e alternative s wil l provid e th e basi s fo r evaluation o f alternatives

. Pag e 18 , Sec

. 3.5.4 , Para

. 4

. Includ e a tabl e showin g th e result s bein g discussed

. Response : Pag e 19 , Para

. 1 , lin e 3

. Defin e "pil e integrity. " Ho w wa s pil e integrit y determined

. Response : Pil e integrit y wa s evaluate d wit h respec t t o structura l stability , deflatio n potential , an d effect s o f freeze/tha w cycling

. Th e structura l stabilit y wa s evaluate d base d o n result s o f fiel d reconnaissanc e an d th e sla g pil e contou r map s fro m surveyin g an d aeria l photography

. Evidenc e o f fissur e zones , sla g bloc k slumpin g o r bloc k rotatio n wer e note d i n th e field

. Angle s o f repos e o f th e pile s wer e calculate d fro m topographi c surveys
. Furthe r detail s ar e presente d i n Sectio n 4. 4 Sla g Pil e Stabilit y i n th e Lea d Sla g R I report

. Pag e 19 , Sec

. 3.6 , line s 2 an d 4

. Cit e th e reference s fo r th e Fina l Sla g Pil e R I (lin e 2 ) an d th e EP A conclusion s (line 4)

. Response : Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n revised

. Th e EP A Conclusion s wer e presente d i n th e Consen t Decre e an d accompanyin g Statemen t o f Work

. Pag e 20 , Para

. 1 , lin e 1

. Provid e a referenc e fo r th e Screenin g Feasibilit y Studty

. Response : Th e Screenin g Feasibilit y Stud y i s an EP A document , date d Septembe r 1993

. Th e referenc e wil l b e adde d t o th e Draf t Fina l F S Wor k Plan

. Pag e 20 , Sec

. 4.1 , lin e 1

. Th e prescreenin g F S ha s no t bee n discusse d before

. Cit e a reference

. Response : Th e Screenin g Feasibilit y Stud y i s an EP A document , date d Septembe r 1993

. The referenc e wil l b e adde d t o the Draf t Fina l F S Wor k Plan

. Pag e 21 , Para

. 1

. Thi s "list" ha s onl y a singl e bullet , s o i t shoul d jus t b e writte n a s a conclusion t o th e introductor y statemen t o n th e previou s pag e a s a singl e continuou s sentence

.I 

### L



# L

L Response :

The tex t o f the Draf t Fina l F S Wor k Plan ha s bee n revised

. Pag e 21 , Sec

. 4.2.1 , Para

. 1

. This discussio n i s confusing

. Th e tex t refer s t o Tabl e 4- 1 a s providin g a lis t o f "...al l o f th e technologie s an d proces s option s tha t wer e considere d technicall y implementabl e .., " an d the n goe s o n t o sa y tha t al l bu t th e bullete d item s wer e ".

. evaluate d durin g th e screenin g FS. " Th e implicatio n i s tha t th e bullete d item s ar e include d withi n th e univers e of"..

. technologies an d proces s options... " tha t ar e "technicall y implementable, " bu t tha t the y wer e no t evaluate d durin g th e screenin g FS

. Severa l question s arise : 1 ) Wh y ar e th e bullete d item s no t include d o n Tabl e 4-1 ? 2 ) Wh y wer e th e bullete d item s no t evaluate d durin g th e screenin g FS ? 3 ) Wh y ar e th e bullete d item s no t discusse d furthe r i n th e presen t F S Wor k Plan ?
! Response :

Th e Draf t Fina l F S Wor k Pla n wil l b e modifie d t o mor e full y explai n th e ^

- Screenin g FS

. Th e SF S bega n wit h a "universa l lis t o f technologies an d proces s options. " Thos e technologies an d proces s option s tha t wer e considere d t o b e no t "technicall y t implementable "

wer e screene d ou t prio r t o evaluatio n o f th e remainin g technologie s fo r ^ * effectiveness
,

implementabilit y an d cos t fo r an y particula r potentia l sourc e area . Th e bullete d item s wer e thos e item s screene d ou t fro m th e universa l lis t (develope d fo r th e sit e ! a s a whol e base d o n genera l respons e actions)

. Pag e 21 , Sectio n 422, Para

. 1

. Cit e a referenc e fo r th e EP A Guidance

. Response : The tex t o f the Draf t Fina l F S Wor k Plan ha s bee n revised

. Pag e 22 , Sec

. 423, Para

. 1 , lin e 2

. Th e wor d "Slag " shoul d b e lowe r case
. Response : Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n revised

. Pag e 22 , Sec

. 4.23 , Para

. 2 , line s 2-4

. Doe s Tabl e 4- 1 represen t th e startin g poin t fo r th e analysi s o f th e SFS ? Response : I n th e SFS
, a lis t o f Genera l Response action s wa s formulate d fo r al l potentia l sourc e area s evaluated

. Fro m these Genera l Respons e Action s a lis t o f potentiall y applicabl e remedia l technologie s an d proces s option s wa s develope d (Tabl e 2- 2 o f th e SFS)

. Thes e potentiall y applicabl e remedia l technologie s an d proces s option s wer e screene d base d o n whether the y wer e technicall y feasibl e t o b e conducte d a t th e Californi a Gulc h Site

. Fro m thi s screening , Tabl e 4- 1 wa s develope d an d i s essentiall y th e sam e fo r eac h potentia l sourc e area . The n Tabl e 4- 1 wa s screene d base d o n th e uniqu e characteristics , informatio n an d remedia l actio n objective

. Fro m Tabl e 4-1 , Tabl e 4- 2 wa s developed

.

### ^ I s Tabl e 4- 1 a reproductio n fro m th e SFS
, o r wa s i t prepare d ne w fo r thi s wor k plan ? Response : Tabl e 4- 1 an d Tabl e 4- 2 wer e take n directl y fro m th e SF S fo r thi s wor k plan

. L Pag e 23 , Para

. 2 , line s 2-3

. No t al l o f th e Remedia l Actio n Alternative s fo r th e sla g pile s ar e describe d i n th e subsequen t text

. Rather
, onl y th e shor t lis t o f screene d alternative s i s L described Response : Th e retaine d alternative s are described

. Fo r a mor e complet e descriptio n th e

_ SF S shoul d b e consulted

. I Pag e 23 , Para

. 2 , line s 3-4

. Th e wor d "were " shoul d b e "was " an d "are " shoul d b e "is"

. Response : Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n | revised

. Pag e 23 , Para

. 3 , lin e 1

. Delet e th e comm a afte r alternatives

. I

. I

- Response :

Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n 

### revised

. ! *• * Pag e 23 , Para

. 3

. Doe s Tabl e 4- 2 represen t th e endin g poin t fo r th e analysi s o f th e SFS ? 1 Response :

Tabl e 4- 2 i s th e endin g point o f th e SF S an d th e beginnin g poin t o f th e **• " Feasibilit

y Stud y t o b e conducte d a s describe d b y thi s wor k plan

. I Pag e 24 , Para

. 1

. Presumably
, thi s discussio n refer s t o possibl e use s o f al l sla g material s a s reflecte d i n th e SFS

. B y definition
, th e sla g fine s tha t ar e th e subjec t o f th e presen t wor k I pla n ar e no t coars e enoug h t o serv e a s ballast

. Response : Fin e sla g canno t b e use d a s ballas t However
, examples o f resourc e utilizatio n

, option s ar e presente d fo r fin e sla g i n th e reference d paragraph

. 

### L Pag e 24 , Sec

. 4.4 , para

. 2 , lin e 2

. Replac e "applicabl e an d relevant " wit h "applicabl e o r i relevan

t an d appropriate"

. 

# L Response :

Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n < revised

. 

### L Pag e 24 , Sec

. 4.4 , last para

. Includ e a tabl e showin g thos e ARAR s o f importanc e t o sla g i fines

. Response : Screenin g o f ARAR s t o thos e o f mos t importanc e t o sla g fine s i s a n exercis e t o i b e conducte d a s par t o f th e Feasibilit y Study

. Pag e 25 , Para

. 2 , line s 6-8

. D o th e ongoin g ris k assessmen t activitie s addres s th e entir e[ ^ Californi a Gulc h site , o r jus t th e slag ? f Response :

Th e Ris k Assessmen t activitie s ar e fo r th e entir e site

. Pag e 26 , Para

. 1 , lin e 3

. Th e wor d "determine " shoul d b e replace d b y "aid" ; EP A wil l selec t : th e preferre d alternative , wit h th e ai d o f th e evaluation s discusse d i n th e FS

. Response : Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n revised

. L

- 

### Pag e 26 , Sec

. 5.2. 1 Para

. 1 , lin e 1

. Th e wor d "criteria " shoul d b e "criterion. " L Response :

Th e tex t o f th e Draf t Fina l F S Wor k Pla n ha s bee n revised

. j Pag e 26 , Sec

. 5.22, Para

. 2 , lin e 3

. Replac e "potentially " wit h "potential. " Response : Th e tex t o f th e Draf t Fina l F S Wor k Plan ha s bee n revised

. i ^ Pag e 26 , Sec

. 52.2. , Complianc e wit h ARARs

. Th e ARAR s appendi x i n th e SF S canno t b e viewe d a s th e "univers e o f ARARs. " Th e ARAR s presente d i n th e SF S d o no t includ e Stat e I ARAR

s whic h wil l b e identifie d i n SF S addendu m o r i n th e detaile d FS

. Response : Th e lis t o f ARAR s produce d fo r th e F S Wor k Plan i s th e sam e lis t a s wa s 1 presente d

i n th e SF S Addendum

. This lis t wil l b e examine d i n th e F S t o identif y an y u ARAR s tha t hav e bee n overlooked

. An y furthe r informatio n updatin g th e lis t o f ARAR s

, currentl y contemplate d woul d b e appreciated

. Pag e 27 , Complianc e wit h ARARs

. Pleas e explai n wh y th e locatio n an d actio n specifi c ARAR s ar e bein g evaluate d differentl y tha n the chemica l specifi c ARARs

. Response : Th e locatio n an d actio n specifi c ARAR s wil l b e evaluate d i n th e sam e manne r a s th e chemica l specifi c ARARs

. Th e languag e i n th e Wor k Plan wa s intende d t o poin t ou t th e sequenc e i n whic h th e ARAR s wil l b e evaluated

. Chemica l specifi c ARAR s ar e evaluate d firs t becaus e the y are require d t o establis h preliminar y remediatio n goals

. Th e univers e o f potentia l locatio n an d actio n specifi c ARAR s ar e screene d earl y i n th e F S bu t ar e not formall y evaluate d unti l the detaile d analysi s o f alternatives

. Attemptin g t o full y evaluat e th e locatio n an d actio n specifi c ARAR s earlie r i n th e F S woul d b e wastefu l a s man y o f th e technolog y options wil l no t surviv e th e screenin g process

. Pag e 29 , Sec

. 5.2.8 , Stat e Acceptance

. Pursuan t t o th e NCP
, thi s sectio n need s t o b e re writte n a s follows : "Stat e comment s an d concern s wil l b e addressed , a s appropriate , durin g th e 

### developmen t o f th e FS

. "Assessmen t o f CD H Concern s wil l b e formall y presente d an d discusse d i n th e

# L 

# L L L L L Propose d

Plan issue d fo r publi c commen t Al l Stat e concern s wil l b e addresse d wit h specia l emphasi s on : 1 ) The State' s positio n o n concern s relate d t o the preferre d 

### alternativ e an d other alternatives ; and , 2 ) Th e State' s comment s on ARAR s or th e propose d us e o f waivers. " Response : The Fina l Draf t F S Wor k pla n ha s bee n revise d t o incorporat e the abov e comment

. • Pag e 30 , Se c 5.2.9

. Communit y Acceptance

. Pursuan t t o th e NCP
, th e languag e i n thi s 

### L sectio n shoul d b e re-writte n as : "Communit y comment s wil l b e take n int o accoun t throughou t th e F S proces s throug h th e communicatio n tha t occu r a s th e communit y relation s pla n i s implemente d t o allo w fo r a preliminar y assessmen t o f communit y acceptance

. Forma l publi c comment s receive d durin g th e publi c commen t perio d fo r th e Propose d Plan an d th e RI/F S repor t wil l als o b e addressed. "
i Response : The Fina l Draf t F S Wor k pla n ha s bee n revise d t o incorporat e the abov e 

### commen t Pag e 30 , Sec

. 5.6 , line s 2-3

. A site-wid e cultura l resource s surve y ha s no t bee n conducte d
a s o f yet

. Curren t polic y i s tha t eac h PR P wil l tak e responsibilit y fo r conductin g survey s i n thei r respectiv e area s o f th e site

. Response : D&RG W intend s t o conduc t a cultura l resource s surve y i n thei r wor k area . Th e 

### tex t wa s intende d t o point ou t tha t severa l bas e documen t whic h la y th e foundatio n fo r thi s wor k hav e bee n alread y prepare d b y ASARCO

. Pag e 32-33

. Severa l o f thes e reference s wer e no t cite d i n th e text , specificall y EP A 1991a , 1990a , 1990b , 1990d , 1998(sic)a
, 1988b ; M K 1991b ; Resurrectio n 1992

. Response : Th e Fina l Draf t F S Wor k pla n ha s bee n revise d t o incorporat e th e abov e comment

. Tabl e 4- 1 an d 4-2

. Ther e ar e numerou s inconsistencie s i n thes e table s wit h respec t t o proces s option s retaine d pe r Tabl e 4-1 , an d thos e cite d i n Tabl e 4-2 : 1 ) Zonin g i s include d i n Tabl e 4- 1 bu t no t note d i n Tabl e 4-2

. 2 ) Poste d Warning s ar e include d i n Tabl e 4- 1 bu t no t note d i n Tabl e 4-2

. 3 ) Communit y Awarenes s i s include d i n Tabl e 4- 1 bu t no t noted i n Tabl e 4-2

. 4 ) Diversio n Ditche s ar e screene d ou t o n Tabl e 4- 1 bu t include d o n Tabl e 4-2

. N o defensibl e reaso n i s give n fo r no t retainin g th e alternativ e i n Tabl e 4-2

. 5 ) Sedimen t Dams/Trap s ar e include d o n Tabl e 4- 1 bu t no t note d i n Tabl e 4- 2 6 ) Onsit e Repositor y i s screene d ou t o n Tabl e 4- 1 bu t include d o n Tabl e 4-2

. 7 ) Physica l Separatio n i s include d i n Tabl e 4- 1 bu t no t note d i n Tabl e 4-2

.

## L 

# L 

# L Response :

Th e item s carrie d fro m Tabl e 4- 1 t o 4- 2 includ e Remedia l Alternative s mad e u p o f on e o r mor e Remedia l Technologie s whic h addres s a Genera l Respons e Actio n category

. Tabl e 4- 1 screene d ou t proces s options

. On e o r mor e proces s option s withi n a Remedia l Technolog y wer e screene d ou t i n Tabl e 4-1 , bu t i n mos t case s a n entir e Remedia l Technolog y categor y wa s no t deleted

. Relevan t remedia l technologie s wer e groupe d togethe r t o for m a remedia l alternativ e (whic h i s wha t i s provide d o n Tabl e 4-2)

. Tabl e 4- 2

_ screene d Remedia l Alternative s an d categorize d the m a s retaine d o r no t retaine d fo r evaluatio n i n th e Feasibilit y Study

. A s mandate d b y th e Consen t Decre e o f Decembe r IS
, ; 199 3 betwee n D&RG W an d th e EPA
, th e onl y remedia l alternative s t o b e evaluated i n th e L Feasibilit y Stud y fo r Stockpile d Fin e Sla g ar e thos e retaine d b y th e SFS

. I t shoul d b e note d tha t th e SF S i s a n EP A documen t whic h wa s th e subjec t o f man y revie w an d commen t cycle s an d i s no w a fina l document , a s o f Septembe r 1993

. Becaus e thes e table s wer e take n directl y fro m the SFS
, an d provid e the startin g poin t o f the FS
, comment s o n whethe r the screenin g proces s i s appropriat e i s probabl y no t a usefu l exercise

. 

# L L L 

# L L 

# L L L L L L L L L