### Preparedfor: 30563 3 RESURRECTIO N MININ G COMPAN Y 170 0 Lincol n Stree t Denver
, Colorad o 8020 3 

# FIL E PLA N

FINA L ENGINEERIN G EVALUATION/COST

ANALYSI S GARIBALD I MIN E SIT E WITHI N UPPE R CALIFORNI

A GULC H
- OPERABL E UNI T 4 CALIFORNI A GULC H SIT E LEADVILLE
, COLORAD O July 1995

Prepared by: TerraMatri x Inc

. Shepher d Miller
, Inc

. 147 5 Pine Grov e Road
, Suit e 10 9 160

0 Spech t Point Drive
, Suit e F Steamboa t Springs
, Colorad o 8047 7 For t

Collins
, Colorad o 8052 5

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### TABL E O F CONTENT S Pag e

No

. 1. 0 EXECUTIV E SUMMAR Y

........................................ . 1 1. 1 GENERA L BACKGROUN

D

............................... . 1 1. 2 PROJEC T SCOP E AN D OBJECTIVE

S

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

1 1 . 3 REMOVA L ACTIO N ALTERNATIVE

S EVALUATE D

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

2 1 . 4 RECOMMENDE

D REMOVA L ACTIO N ALTERNATIV

E

......... . 4 1. 5 REPOR T ORGANIZATIO

N

............................... . 4 2 . 0 SIT E CHARACTERIZATIO

N

..................................... . 6 2 . 1 SIT E DESCRIPTIO

N AN D BACKGROUN D

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

6 2.1. 1 Sit e Identificatio n an d Background

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

6 2.1. 2 Regulatory Framewor k

............................... . 6 2.1. 3 Facilit y Typ e an d Operationa l Statu s
...................... .

6 2.1. 4 Topograph y ....................................... . 7 2.1. 5 Pedolog y and Geolog y ................................ . 7 2.1. 6 Hydrolog y ........................................ . 7 2.1. 7 Surroundin g Lan d Us e and Populatio n .................... .

9 2.1. 8 Sensitiv e Ecosystems
................................. . 9 2.1. 9 Climat e .......................................... . 9 2.1.1 0 Histori c an d Cultura l Resource s
......................... .

1 0 2. 2 PREVIOU S REMOVA L ACTION

S

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

1 0 2. 3 SOURCE
, NATURE
, AN D EXTEN T O F CONTAMINATIO

N

..... . 1 1 2.3. 1 Identificatio n o f Source s o f Hazardou s o r Contaminatin g Substance s
........................................ . 1 1 2.3. 2 Characteristic s o f Sourc e .............................. . 1 1 2.3. 3 Physica l an d Chemica l Attribute s o f Contaminatio n ........... .

1 4 2.3. 4 Areas Affecte d

..................................... . 2 5 2. 4 RIS K ASSESSMEN

T

...................................... . 2 5 2.4. 1 Scop e o f Ris k Evaluatio n .............................. . 2 5 2.4. 2 Conceptua l Sit e Mode l

................................ . 2 5 2.4. 3 Applicatio n t o Garibald i Min e Sit e Remova l Actio n ........... .

2 6 3. 0 IDENTIFICATIO

N O F REMOVA L ACTIO N OBJECTIVE

S

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

2 7 3. 1 STATUTORY

LIMIT S O N REMOVA L ACTION S

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

2 7 3. 2 REMOVA L ACTIO N SCOPE
, GOALS
, AN D OBJECTIVE

S

....... . 2 7 3.2. 1 Remova l Actio n Scop e ................................ . 2 7 3.2.2 Remova l Actio n Goal s
................................ . 2 7 3.2. 3 Remova l Actio n Objective s
............................ .

2 7 3. 3 REMOVA L ACTIO N SCHEDUL E

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

2 8 3.3. 1 Remova l Schedul e ................................... . 2 8 3.3. 2 Planne d Activitie s
................................... . 2 8 

### 4 . 0 IDENTIFICATIO

N AN D ANALYSI S O F REMOVA L ACTIO N ALTERNATIVE

S

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

2 9 4 . 1 ALTERNATIV

E IDENTIFICATIO

N AN D INITIA L SCREENIN G

.. . 2 9 4. 2 EVALUATIO

N CRITERI A

................................. 3 1
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_________________________________ FINAL * EE/CA Garibaldi Mine Site » ii 4 . 3 ALTERNATIV

E A
- SURFAC E WATE R AN D PORTA L FLO W DIVERSIO N

........................................... . 3 3 4.3. 1 Descriptio n o f Alternativ e A

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

3 3 4.3.2 Analysi s o f Alternativ e A

.............................. . 3 4 4 . 4 ALTERNATIV

E B
- SURFAC E WATER
, PORTA L FLOW
, AN D SHALLO W ALLUVIA

L GROUNDWATE R

DIVERSIO N

......... .

3 6 4.4. 1 Descriptio n o f Alternativ e B

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

3 6 4.4. 2 Analysi s o f Alternativ e B

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

3 7 4 . 5 ALTERNATIV

E C
- SURFAC E WATER
, PORTA L FLOW
, AN D SHALLO W ALLUVIA L

GROUNDWATE R DIVERSION/REGRADING/SIMPL E COVE R

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

3 9 4.5. 1 Descriptio n o f Alternativ e C

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

3 9 4.5. 2 Analysi s o f Alternativ e C

.............................. . 4 0 4. 6 ALTERNATIV

E D
- WAST E ROC K REMOVA L

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

4 2 4.6. 1 Descriptio n o f Alternativ e D

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

42 4.6.2 Analysi s o f Alternativ e D

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

4 3 5 . 0 COMPARATIV

E ANALYSI S O F REMOVA L ACTIO N ALTERNATIVE

S

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

4 6 6. 0 RECOMMENDE

D REMOVA L ACTIO N ALTERNATIV

E

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

4 8 6. 1 DESCRIPTIO

N O F ALTERNATIV

E B

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

4 8 6. 2 RATIONAL

E FO R SELECTIO N O F ALTERNATIV

E B

.......... . 4 9 6.2. 1 Effectivenes s
....................................... . 4 9 6.2. 2 Implementabilit

y .................................... . 50 6.2. 3 Cost.............................................

. 5 0 7. 0 REFERENCES

................................................. . 5 1

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### LIS T O F TABLE S Tabl e No

. Descriptio n Pag e No

. 1 Garibald

i Wast e Roc k Dat a ................................ . 1 2 2 Surfac e

Wate r Analysis - Californi a Gulch Upstrea m o f Garibald i Min e Sit e 15-16 3 Surfac e

Wate r Analysi s - Garibald i Porta l

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

17-1 8 4 Surfac e

Wate r Analysi s - Garibald i Wast e Roc k Pil e (To e Seep)

..... . 19-2 0 5 Surfac e

Wate r Analysi s - Californi a Gulc h Downstrea m o f Garibald i Min e Sit e .................................... . 21-2 2 6 Garibald

i Ground-wate r Analysi s
............................ .

2 3 7 Alternativ e

A
- Cos t Summar y ............................. . 3 6 8 Alternativ e

B
- Cos t Summar y .............................. . 3 9 9 Alternativ e

C
- Cos t Summar y .............................. . 4 2 1 0 Alternativ e

D
- Cos t Summar y .............................. . 4 4 1 1 Compariso n

o f Alternative s
................................ . 4 5 1 2 Summar

y o f Garibald i Wast e Roc k EE/C A Alternative s
........... .

4 6

1 2 

### LIS

T O F FIGURE S (located following text) Figur e No

. Descriptio n Genera l Locatio n Operabl e Uni t 4 

### LIS T O F DRAWING S (located following text) Drawin g No

. Descriptio n 1 2 3 4 5 Garibald

i Min e Site Existin g Condition s Garibald i Min e Sit e Alternativ e A Garibald i Min e Sit e Alternativ e B Garibald i Min e Sit e Alternativ e C Garibald i Min e Sit e Alternativ e D

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### LIS T O F ATTACHMENT S Attachmen t Descriptio n 1 Publi c

Comment s an d Response s 

### LIS T O F APPENDICE S Appendi x Descriptio n A B C D E F G State Histori c Preservatio n Offic e Lette r HEC- 1 Mode l HEL P Mode l Soi l Los s Calculation s Stabilit y Analysi s ARAR s Cos t Estimate s

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___________________________________ FINAL * EE/CA Garibaldi Mine Site » 1 

### 1 . 0 EXECUTIV

E SUMMAR Y Appendi x 1 . 1 GENERA L BACKGROUN

D Thi s Engineerin g Evaluation/Cos t Analysi s (EE/CA ) ha s bee n performe d t o identif y a preferre d non-tim e critica l remova l actio n t o be implemente d fo r th e Garibald i Min e sit e locate d within Uppe r Californi a Gulch

. Thi s area , locate d approximatel y thre e mile s southeas t o f th e Cit y o f Leadville
, i s par t o f Operabl e Uni t 4 (OU-4 ) o f th e Californi a Gulc h Superfun d Sit e (Site ) in Lak e County
, Colorado

. Th e genera l locatio n o f th e Californi a Gulc h Superfun d Sit e i s show n i n Figur e 1, Genera l Location

. OU- 4 i s define d as th e are a hydrologicall y draine d b y Californi a Gulc h fro m immediatel y upstrea m o f th e Ya k Porta l t o th e headwater s o f th e gulch , a s show n i n Figur e 2, Operabl e Uni t 4

. The are a cover s approximatel y 2. 4 square mile s and contains min e wast e piles , mil l tailing , an d fluvia l tailin g material

. Approximatel y 15 0 min e wast e roc k pile s exist i n thi s are a (USDC
, 1994)

. Samplin g o f surfac e water , groundwate r an d strea m sediment s indicate s tha t minin g activitie s ma y hav e produce d aci d min e drainag e and heav y metal contaminatio n whic h hav e impacte d thes e media

. Remedia l investigatio n activitie s identifie d fluvia l tailing an d wast e roc k pile s a s area s potentiall y requirin g remedia l actio n withi n OU-4

. Th e Garibald i Min e sit e i s locate d withi n OU- 4 nea r th e headwater s o f Californi a Gulch
, as show n i n Drawin g 1 , Garibald i Min e Sit e Existin g Conditions

. Prominen t feature s a t th e Garibald i Min e sit e includ e a wast e roc k pil e coverin g an are a o f approximatel y 1. 6 acre s and
a collapse d min e porta l (WCC
, 1990)

. A stea m engine an d othe r minin g remain s ar e locate d adjacen t t o th e collapse d portal

. Run-o n diversio n channel s hav e bee n constructe d b y th e Resurrection/ASARC O

Join t Ventur e around th e wast e roc k pil e (WCC
, 1990)

. I n addition , a portio n o f th e porta l discharg e i s currentl y diverte d aroun d th e pile

. Previou s sit e activitie s ar e furthe r discusse d i n Sectio n 2.2

. Surfac e water dat a indicat e tha t th e wast e roc k pil e and/o r th e Garibald i Min e porta l continu e t o contribut e t o surfac e water contaminatio n (acidi c p H levels ; elevate d heav y metal loadings ) i n Uppe r Californi a Gulch

. Seasonal fiel d observation s noted b y Resurrectio n i n 1993/9 4 (SML
, 1994 ; SMI/TerraMatrix
, 1994b ; SMI/TerraMatrix
, 1995 ) indicat e tha t water discharge s fro m th e to e o f th e pile

. Potentia l flo w pathway s through th e wast e roc k pil e ar e furthe r discusse d i n Sectio n 2.3.3

. 1 . 2 PROJEC T SCOP E AN D OBJECTIVE S Thi s EE/C A identifie s an d evaluates remova l actio n alternative s fo r th e Garibald i Min e sit e in OU-4

. Th e projec t scop e include s sit e characterizatio n (utilizin g existin g Remedial Investigatio n dat a an d additionall y collecte d fiel d data) ; identificatio n o f remova l actio n objectives ; identificatio n an d analysi s o f remova l actio n alternatives ; an d th e selectio n o f th e preferre d
remova l action

. Th e objectiv e o f th e EE/C A i s t o identif y a preferre d remova l actio n tha t cost

effectivel y control s o r reduce s the releas e o f contaminant s t o the environmen t and consequentl y 

### reduce s th e potentia l ris k t o huma n healt h and th e environmen t pose d b y suc h releases

. Thi s remova l actio n i s par t o f the overal l remedia l activitie s bein g undertake n i n the OU- 4 Feasibilit y Stud y (FS ) b y Resurrectio n Minin g Company

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___________________________________ FINAL * EE/CA Garibaldi Mine Site » 2 alternative s evaluate d i n thi s EE/C A ar e considere d t o represen t interi m respons e action s i n th e context tha t remedia l alternative s fo r wast e roc k an d othe r source s i n OU- 4 wil l als o b e evaluate d i n the Feasibilit y Study

. The propose d remova l action s ar e not intende d t o b e fina l actions , bu t ar e rathe r intende d t o contribut e t o th e efficien t performanc e o f th e remedia l actions fo r OU-4

. Th e Recor d o f Decisio n (ROD ) fo r OU- 4 wil l ultimatel y determin e whethe r furthe r remedia l actions ar e required

. 1 . 3 REMOVA L ACTIO N ALTERNATIVE S

EVALUATE D Thi s EE/C A discusse s efficient
, implementable , an d cost-effectiv e technologie s tha t appl y t o wast e roc k remova l actions

. Guidanc e fo r th e identificatio n o f appropriat e technologie s i s fro m th e Final Screening Feasibility Study fo r Remediation Alternatives a t th e California, Gulch NP L Site, Leadville, Colorado, (SFS ) particularl y Sectio n 9 , Wast e Roc k (EPA
, 1993a ) an d fro m th e EPA

approvedFzrM / Engineering Evaluation/Cost Analysis Work Plan fo r th e Garibaldi Mine Site(OU4 ) (TerraMatrix/SMI

, 1994)

. Guidanc e fo r th e preparatio n o f thi s EE/C A i s als o provide d in th e Guidance o n Conducting Non-Time-Critical

Removal Actions Under th e Comprehensive Environmental Response, Compensation, an d Liability Ac t (EPA
, 1993b)

. T h e SF S retaine d th e following wast e roc k alternative s fo r detaile d analysi s i n th e Feasibilit y Study : • Alternativ e 1 : N o Actio n • Alternativ e 2 : Institutiona l

Contro l • Alternativ e 3 : Containmen t

(Surfac e Wate r Control)/Institutiona l

Contro l • Alternativ e 4 : Containmen t

(Surfac e Wate r Control
, Surfac e Barrier) / Institutiona l Control s • Alternativ e 5 : Containmen t

(Surfac e Wate r Control
, Sourc e Surfac e Control) / Institutiona l Control s • Alternativ e 6 : Containmen t

(Surfac e Wate r Control
, Sourc e Surfac e Control
, Surfac e Barrier)/Institutiona l

Control s • Alternativ e 7 : Removal/Transport/Disposal/Institutiona l Control s Site-specifi c application s o f thes e broadl y define d alternative s wer e considere d an d a limite d numbe r o f appropriat e remova l actio n alternative s addressin g wast e roc k wer e retaine d fo r analysi s withi n this EE/C A as furthe r discusse d i n Sectio n 4.0

. Th e alternative s analyze d incorporat e site-specifi c application s o f th e SF S Alternatives

. I n addition , th e alternative s ar e consisten t wit h th e nature an d exten t o f contaminatio n an d th e remova l actio n objectives

. Th e remova l actio n alternative s analyze d in furthe r detai l within thi s EE/C A include : • Alternativ e A : Surfac e Wate r an d Porta l Flo w Diversio n — Thi s alternativ e entail s th e interceptio n an d diversio n o f strea m flo w (includin g porta l flow ) aroun d the wast e roc k b y reconstructio n o f existin g channel s and/o r constructio n o f
ne w channel s t o prevent run-o n t o and/o r infiltratio n throug h th e wast e rock

. Alternativ e A i s show n o n Drawin g 2 an d correspond s t o Alternativ e 3 a s presente d i n t h e SF S (EPA
, 1993a)

. • Alternativ e B : Surfac e Water
, Porta l Flow
, an d Shallo w Alluvia l Groundwate r Diversio n — Thi s alternativ e include s th e interceptio n an d diversio n o f stream flo w (includin g porta l
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Alternativ e C : flow ) around th e wast e roc k b y reconstructio n o f existin g channel s and/o r constructio n o f ne w channel s t o preven t run-o n t o and/o r infiltratio n throug h th e wast e rock

. I t als o entail s th e diversio n o f shallo w alluvia l groundwate r flo w aroun d th e wast e roc k b y constructio n o f groundwate r intercepto r trenches

. Alternativ e B i s show n on Drawin g 3 and als o correspond s t o Alternativ e 3 a s presente d i n the S F S (EPA
, 1993a)

. Surfac e Water
, Porta l Flow
, an d Shallo w Alluvia l Groundwate r Diversion/Regrading/Simpl

e Cove r — Thi s alternativ e include s th e interceptio n an d diversio n o f strea m flo w (includin g porta l flow ) around th e wast e roc k b y reconstructio n o f existin g channel s and/o r constructio n o f
ne w channel s t o preven t run-o n t o and/o r infiltratio n throug h th e wast e rock ; diversio n o f shallo w alluvia l groundwate r flo w aroun d th e wast e roc k b y constructio n o f groundwate r intercepto r trenches ; an d regradin g o f th e wast e roc k pil e an d constructio n o f a simpl e cove r t o minimiz e infiltratio n throug h th e wast e roc k pil e an d expedit e non-erosive runof f fro m th e pil e surface

. Th e simpl e cove r woul d b e designe d a s bot h a source surfac e contro l and surfac e barrier

. Alternativ e C i s show n i n Drawin g 4 and correspond s t o Alternativ e 5 a s presente d i n t h e SF S (EPA
, 1993a)

. Wast e Roc k Remova l — Thi s alternativ e entail s th e remova l
o f th e wast e roc k fro m th e sit e an d transpor t t o th e Oregon Gulc h Tailin g Impoundmen t fo r disposal

. I t als o include s reestablishmen t o f th e origina l drainag e channel

. Alternativ e D
, show n on Drawin g 5 , correspond s t o Alternativ e 7 as presente d i n th e SF S (EPA
, 1993a)

. Institutiona l control s (Alternativ e 2 i n th e SFS)
, includin g poste d warnings , informatio n an d educatio n programs , and/o r othe r control s woul d als o be incorporate d as approve d b y th e EPA
, withi n th e remova l actio n alternative s evaluated

. Th e criteri a utilize d i n th e analysi s o f th e fou r remova l actio n alternative s ar e define d i n th e Guidance on Conducting Non-Time-Critical

Removal Actions Under the Comprehensive Environmental Response, Compensation,, an d Liability Ac t (CERCLA) (EPA
, 1993b)
, an d includ e effectiveness
, implementability ,

an d cost

. Thes e EP A criteri a ar e utilize d a s screenin g criteria t o ai d i n th e selectio n o f th e appropriat e remova l actio n fo r th e Garibald i Min e site

. I n addition , th e Work Area Management Plan (WAMP ) (USDC
, 1994 ) performanc e criteria o f erosio n stabilit y an d flo w capacit y an d stabilit y ar e utilize d i n evaluatin g th e effectivenes s o f th e remova l actio n alternative s i n meetin g th e remova l actio n objective s (RAOs)

. RAO s ar e furthe r discusse d i n Sectio n 3.2

. Afte r detaile d evaluatio n o f th e individua l remova l actio n alternative s (Sectio n 4.0)
, a comparativ e analysi s o f thes e alternative s i s presente d (Sectio n 5.0 ) whic h identifie s th e Alternativ e D :

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___________________________________ FINAL * EE/CA Garibaldi Mine Site » 4 advantage s an d disadvantage s o f eac h alternativ e relativ e t o on e anothe r considerin g th e EP A criteri a o f effectiveness
, implementability ,

an d cost

. 1 . 4 RECOMMENDE D

REMOVA L ACTIO N ALTERNATIV

E Base d o n th e individua l analysi s o f alternatives presente d i n Sectio n 4. 0 an d th e comparativ e analysi s presente d in Sectio n 5.0 , Alternativ e B (Surfac e Water
, Porta l Flow
, an d Shallo w Alluvia l Groundwate r Diversion ) i s recommende d fo r implementation

. Alternativ e B woul d
mee t the RAO s describe d i n Sectio n 3.2

. Alternativ e B entail s th e interceptio n an d diversio n o f strea m flo w (includin g porta l flow )
aroun d th e wast e roc k b y th e reconstructio n o f existin g channel s and/o r th e constructio n o f
ne w channel s t o preven t run-o n t o and/o r infiltratio n through th e wast e rock

. I t als o entail s th e diversio n o f shallo w alluvia l groundwate r flo w aroun d th e wast e roc k b y constructio n o f groundwate r intercepto r trenches

. Bes t management practice s (BMPs)
, a s describe d unde r Alternativ e A i n Sectio n 4.3.1. 2 woul d be utilize d durin g al l constructio n activitie s a t th e site

. 1 . 5 REPOR T ORGANIZATIO N Thi s EE/C A i s organize d int o seve n Section s a s follows : • Sectio n 1. 0 — Executiv e Summary : Thi s sectio n provide s a genera l overview o f th e site , projec t scop e an d objectives , remova l actio n alternative s evaluated , th e evaluatio n performed
, th e recommende d remova l actio n alternative , an d a general overview o f th e content s o f th e EE/CA

. • Sectio n 2. 0 — Sit e Characterization : Thi s sectio n provide s a discussio n o f th e sit e descriptio n an d background ; previou s remova l actions ; source , nature , an d exten t o f contamination ; analytica l data ; an d th e streamline d ris k evaluation

. • Sectio n 3. 0 — Identificatio n o f Remova l Actio n Objectives : Thi s sectio n present s statutory limit s o n remova l actions , determinatio n o f remova l actio n scope , and th e remova l actio n schedule

. • Sectio n 4. 0 — Identificatio n an d Analysi s o f Remova l Actio n Alternatives : Remova l actio n alternative s ar e identifie d an d evaluate d based upo n effectiveness
, implementability , an d cost

. •' Sectio n 5. 0 — Comparativ e Analysi s o f Remova l Actio n Alternatives : I n thi s section , a comparativ e analysi s i s presente d whic h identifie s th e advantage s an d disadvantage s o f eac h alternativ e relativ e t o on e anothe r considerin g th e criteri a o f effectiveness
, implementability ,

an d cost

. • Sectio n 6. 0 — Recommende d Remova l Actio n Alternative : The remova l actio n tha t bes t satisfie s th e evaluatio n criteri a i s recommende d an d describe d i n this 

### section

. • Sectio n 7. 0 — Thi s sectio n list s reference s cite d i n th e text

.
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_________________________________ FINAL * EE/CA Garibaldi Mine Site » 5 Supportin g dat a i s presente d in several appendices , as outline d below : Appendi x A
— Stat e Histori c Preservatio n Offic e Lette r Appendi x B
— HEC- 1 Mode l Appendi x C
- HEL P Mode l Appendi x D
— Soi l Los s Calculation s Appendi x E
— Stabilit y Analysi s Appendi x F
— ARAR s Appendi x G
— Cos t Estimate s

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___________________________________ FINAL * EE/CA Garibaldi Mine Site » 6 

### 2 . 0 SIT E CHARACTERIZATIO N

2 . 1 SIT E DESCRIPTIO N

AN D BACKGROUN D 

### 2.1. 1 Sit e Identificatio n an d Backgroun d Thi s EE/C A has bee n prepare d t o evaluat e potentia l remova l actio n alternative s an d t o selec t a preferre d alternativ e fo r th e remediatio n o f wast e roc k a t th e Garibald i Min e sit e locate d withi n Uppe r Californi a Gulch

. Thi s area , locate d approximatel y thre e miles southeas t o f th e Cit y o f Leadville
, i s par t o f Operabl e Uni t 4 (OU-4 ) o f th e Californi a Gulc h Superfun d Sit e in Lak e County
, Colorado

. Lake Count y i s approximatel y 10 0 miles southwes t o f the Cit y o f Denver

. Th e genera l locatio n o f th e Californi a Gulc h Superfun d Sit e i s show n in Figur e 1 , General Location

. Th e Californi a Gulch/Leadvill e are a ha s bee n a n active minin g are a since th e 1850s

. Associate d wit h th e extensiv e undergroun d minin g activitie s ar e th e remainin g surfac e feature s suc h a s min e workings , wast e rock, an d tailin g ponds

. I n addition , min e drainag e tunnel s wer e constructe d t o dewate r the min e workings

. OU- 4 i s define d a s the are a hydrologicall y drained b y Californi a Gulc h fro m immediatel y upstrea m o f th e Ya k Porta l t o th e headwater s o f th e gulch , a s show n i n Figur e 2, Operabl e Unit 4

. Th e are a cover s approximatel y 2. 4 squar e miles an d contain s min e wast e piles , mil l tailing , an d fluvia l tailin g material

. Approximatel y 15 0 min e wast e roc k pile s exist i n thi s are a (USDC
, 1994)

. Samplin g o f surfac e water, groundwater , an d stream sediment s indicat e tha t minin g activitie s ma y hav e contribute d aci d min e drainag e and heav y metal contaminatio n t o thes e media

. Remedial investigatio n activitie s identifie d fluvia l tailin g an d wast e roc k pile s as area s potentiall y requirin g remedia l actio n withi n OU-4

. Th e subjec t o f this EE/C A i s th e wast e roc k locate d at th e Garibald i Min e sit e i n OU-4

. Th e Garibald i Min e sit e i s locate d withi n OU- 4 nea r th e headwaters o f Californi a Gulch
, a s show n i n Figur e 2 , Operabl e Uni t 4, and detaile d in Drawin g 1 , Garibald i Min e Site Existin g Conditions

. 

### 2.1. 2 Regulator y Framewor k Thi s EE/C A ha s bee n undertake n i n accordanc e wit h th e Work Area, Management Plan (WAMP ) fo r Resurrectio n Minin g Compan y include d a s a n appendix t o th e Consen t Decre e i n settlemen t o f Civi l Actio n No

. 83-C-2388
, Unite d State s Distric t Court fo r th e Distric t o f Colorad o (USDC
, 1994)
, and i n accordanc e wit h guidanc e provide d i n 4 0 Cod e o f Federa l Regulation s (CFR ) 300

. I n addition , guidanc e provide d within th e Guidance o n Conducting Non-Time- Critical Removal Actions Under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) (EPA
, 1993b ) ha s bee n incorporate d int o thi s EE/C A study

. 

### 2.1. 3 Facilit y Typ e an d Operationa l Statu s The Garibald i Mine sit e i s locate d withi n OU- 4 nea r the headwater s o f Californi a Gulch approximatel y 15 0 fee t wes t o f th e Wester n Faul t betwee n Breec e Hil l an d Gree n Mountain (WCC
, 1990)

. Th e Garibald i Min e sit e i s show n i n Drawin g 1 , Garibald i Min e Sit e Existin g Conditions

. A s a componen t o f Garibald i Mine
, th e Garibald i tunne l extend s 240 0 fee t northeas t t o th e workings o f th e Sunday No

. 2 Min e o n th e wes t slop e o f Bal l Mountain
, an d
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_________________________________ FINAL * EE/CA Garibaldi Mine Site 4 7

wa s buil t t o drain thes e workings (Emmons e t al. , 1929)

. Prominen t feature s a t th e Garibald i Min e sit e includ e a wast e roc k pil e coverin g a n are a o f approximatel y 1. 6 acre s and a collapse d min e porta l (WCC
, 1990)

. A stea m engine and othe r minin g remain s are locate d adjacen t t o the collapse d portal

. " Run-o n diversio n channel s hav e bee n constructe d b y th e Resurrection/ASARC O

Join t Ventur e aroun d th e wast e roc k pile

. I n addition , a portio n o f th e porta l discharg e i s currentl y diverte d aroun d th e pil e (WCC
, 1990)

. Surfac e wate r dat a indicate s tha t th e wast e roc k pil e continue s t o contribut e t o surfac e wate r contaminatio n (acidi c p H levels ; elevate d heav y metal loadings ) i n Uppe r Californi a Gulch

. Fiel d observation s b y Resurrectio n indicat e tha t wate r discharge s fro m th e to e o f th e pile

. 

### 2.1. 4 Topograph y T h e Garibald i Min e sit e i s locate d nea r th e headwater s o f Californi a Gulc h in a smal l tributar y drainage , a s show n i n Figur e 2 an d Drawin g 1

. Th e sit e i s a t a n elevatio n o f approximatel y 11,17 5 fee t abov e mea n se a leve l (AMSL ) a t th e porta l an d 11,12 0 fee t AMS L a t th e to e o f th e wast e roc k pile

. Th e channel downstrea m o f th e Garibald i Min e sit e i s a small , V-shape d valle y wit h wate r flowin g in a southwesterl y direction

. Uppe r Californi a Gulc h crosse s Lak e Count y Roa d 2, approximatel y on e thir d o f a mil e downstrea m o f th e Garibald i Min e site

. 

### 2.1. 5 Pedolog y an d Geolog y Th e Troutvill e an d Bros s series , consistin g o f deep , wel l draine d soil s o n mountai n slopes , ar e th e predominan t soi l type s in th e vicinit y o f th e Garibald i Min e site

. Deep
, sand y loam , withi n th e Tomich i series , als o occur s in drainag e channel s upgradien t o f th e Garibald i Min e site

. T h e geology i n Uppe r Californi a Gulc h consist s o f shallo w colluviu m ove r Precambria n graniti c an d metamorphi c rock s an d Paleozoi c sedimentar y rocks

. Th e Pendr y Fault
, a loca l prominen t faul t markin g th e boundar y betwee n Lowe r an d Uppe r Californi a Gulch
, has a nort h 2 0 degree s eas t tren d (Emmon s e t al. , 1927)

. Th e Garibald i Min e sit e i s locate d upstrea m o f th e Pendr y Fault

. Californi a Gulc h wa s no t glaciate d an d upstrea m o f th e Pendr y Faul t th e unconsolidate d materia l ca n generall y b e characterize d a s relativel y thi n deposit s o f alluvium , talus , an d colluvium

. Extensiv e area s o f th e Uppe r Californi a Gulc h drainage , includin g mos t o f Iro n an d Breec e Hills
, ar e covere d wit h a thi n laye r o f talu s "wash " whic h consist s o f fragment s o f th e underlyin g bedroc k (WWL
, 1990)

. 

### 2.1. 6 Hydrolog y OU- 4 include s th e Uppe r Californi a Gulc h drainag e basi n whic h i s th e are a hydrologicall y draine d b y Californi a Gulc h fro m immediatel y upstrea m o f th e Ya k Tunne l Porta l t o th e headwater s o f th e gulch

. Approximatel y 2. 4 squar e mile s ar e draine d b y Uppe r Californi a Gulch

. Th e Garibald i Min e sit e i s locate d i n th e Uppe r Californi a Gulc h sub-basi n whic h cover s a n are a o f approximatel y 21 1 acres
. The sit e i s locate d at the confluenc e o f two headwate r sub-basin s o f Uppe r Californi a Gulch

. Th e norther n headwate r basi n cover s a n are a o f approximatel y 13 4 acres , drainin g a portio n o f th e souther n flan k o f Breec e Hil l an d th e northwester n flan k o f Bal l Mountain

. Th e channe l outle t drainin g th e norther n headwate r sub-basi n lie s slightl y t o th e northwes t o f the min e portal

. The souther n headwate r basi n cover s approximatel y 7 7 acres , drainin g th e wester n portio n o f Bal l Mountai n an d th e northerl y portio n o f th e topographi c divid e tha t separate s Uppe r Californi a Gulc h fro m Uppe r Iow a Gulch

. Th e channel outle t
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___________________________________ FINAL * EE/CA Garibaldi Mine Site » 8 drainin g th e souther n headwate r sub-basi n lie s slightl y southeas t o f th e min e portal

. Surfac e wate r flo w i n thi s sectio n o f Uppe r Californi a Gulc h i s ephemeral , generall y resultin g fro m snowmel t or summe r thunderstorms

. Surfac e wate r samplin g an d flo w measurement hav e bee n conducte d i n th e vicinit y o f th e Garibald i Min e site

. Sectio n 2.3. 3 discusse s wate r qualit y dat a fo r sample s collecte d upstream , downstream , a t th e portal , an d a t th e to e o f th e Garibald i Min e site

. Th e wate r i s generall y characterize d b y lo w p H wit h elevate d level s o f dissolve d metals

. Groundwate r i n th e Leadvill e are a occur s i n bot h bedrock an d alluvia l stratigraphy

. Th e geologi c structur e o f th e regio n varie s i n relatio n t o th e Pendry Fault

. Th e Pendr y Faul t lie s alon g th e easter n edg e o f Leadvill e an d intersect s Californi a Gulc h jus t belo w th e Yak Tunne l Treatmen t Plan t surg e pon d (WWL
, 1990)

. Downstrea m o f th e Pendry Faul t dee p terrac e gravel
a n d lak e be d unconsolidate d deposit s cove r th e bedrock

. Upgradien t o f th e Pendry Fault
, Californi a Gulc h wa s no t glaciate d (Tweto
, 1970)
, and unconsolidate d material can generall y b e characterize d a s relativel y thi n deposit s .o f alluvium , talus , an d colluviu m ove r Precambriu m graniti c an d metamorphi c rock s an d Palozoi c sedimentar y rock s (Tweto
, 1970 ; WWL
, 1990 ; WCC
, 1993a)

. Alluviu m occurrin g i n th e Uppe r Californi a Gulc h as grave l deposit s i s limite d t o th e be d o f Californi a Gulc h (Emmons
, e t al. , 1927)

. Drilling log s sugges t tha t i n OU- 4 th e thicknes s o f th e overlyin g unconsolidate d alluvium/colluviu m

range s fro m 2 t o 4 3 fee t (EPA
, 1987a ; WCC
, 1993a)

. T h e variou s type s o f roc k tha t compris e th e bedrock ar e considere d t o for m a singl e aquife r syste m becaus e the y are hydraulicall y connected throug h min e working s and the extensiv e faulting an d fracturin g (Tur k an d Taylor
, 1979)

. A comple x syste m o f majo r an d mino r fault s cause s significan t displacemen t an d fracturin g o f th e bedroc k (Emmons
, e t al. , 1927)

. Flo w withi n the bedroc k i s primaril y facilitate d b y secondar y porosit y and min e workings i n the are a (WCC
, 1993a)

. Secondar y porosit y consist s o f th e permeabl e an d highl y fracture d zone s adjacen t t o th e majo r fault s an d th e numerou s interconnecte d mino r fault s an d fracture s withi n t h e faul t blocks

. Th e groundwate r i n Uppe r Californi a Gulc h occur s primaril y i n bedroc k aquifer s (EPA
, 1987)
, apparentl y existin g unde r unconsolidate d conditions , however, irregularitie s i n th e fractur e dominate d flo w syste m ma y caus e partiall y confine d o r perche d condition s locall y (WCC
, 1993a)

. Th e surficia l alluvium/colluviu m

deposit s appea r t o b e locall y saturate d wit h groundwate r (WCC
, 1993a ; SMI/TerraMatrix
, 1995a)

. Regionally
, recharg e o f alluvia l an d bedrock aquifer s result s fro m infiltratio n o f precipitatio n (rainfal l an d snowmelt ) an d surfac e water

. S i x backgroun d bedroc k groundwate r well s an d thre e bedroc k monitorin g well s wer e installe d withi n th e Californi a Gulc h Sit e durin g th e Remedia l Investigatio n (RI ) proces s (WCC
, 1993a)

. Fou r o f th e backgroun d bedroc k groundwate r well s ar e locate d withi n OU-4

. Additionally
, tw o shallo w alluvia l monitorin g well s wer e installe d withi n OU- 4 i n 1989 , onl y on e o f whic h i s currentl y operationa l (WWL
, 1990)

. Durin g th e fal l o f 1994 , thre e additiona l groundwate r monitorin g well s wer e constructed , two whic h ar e adjacen t t o the Garibald i Min e sit e an d on e withi n th e Agwal t Min e sit e (SMI/TerraMatrix
,

1995a)

. The monitorin g well s drille d a s par t o f the R I wer e installe d t o depth s o f 29 1 t o 1,22 7 feet

. Dept h t o groundwate r i n th e bedroc k aquife r rang e fro m abou t 3 0 fee t t o roughl y 670 fee t belo w groun d surface

. A t th e operationa l alluvia l groundwate r wel l upgradien t o f th e Ya k Tunne l Portal
, a golde n brow n dolomit e bedrock wa s encountere d a t a dept h o f 4 3 fee t (EPA
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___________________________________ FINAL * EE/CA Garibaldi Mine Site » 9 1987a)
, an d th e dept h t o groundwate r range s fro m approximatel y 5. 9 t o 15. 8 belo w groun d surfac e (WWL
, 1990 ; SMI
, 1994 ; SMI/TerraMatrix
, 1994b ; SMI/TerraMatrix
, 1995)

. Dept h t o bedrock i n th e tw o groundwate r well s installe d a t th e Garibald i sit e ranged fro m approximatel y 1 0 t o 1 1 feet
, respectivel y (SMI/TerraMatrix
,

1995b)

. Localize d groundwate r wa s encountere d i n one o f the well s durin g constructio n at approximatel y 9. 5 fee t belo w ground surface

. 

### 2.1. 7 Surroundin g Lan d Us e an d Populatio n T h e Californi a Gulc h Sit e i s locate d i n th e uppe r Arkansa s Rive r watershed , wit h elevation s rangin g fro m approximatel y 9,57 0 fee t AMS L t o 12,25 0 fee t AMSL

. Th e sit e encompasse s approximatel y 16. 5 squar e mile s an d include s th e town s o f Leadvill e an d Stringtow n an d extend s t o th e confluenc e o f Californi a Gulc h an d th e Arkansa s River

. Th e sit e i s locate d i n a highl y mineralize d are a o f th e Rock y Mountains
, an d mining , minera l processin g an d smeltin g activitie s hav e produce d gold , silver , lea d an d zin c fo r mor e tha n 13 0 years
. A larg e portio n o f thi s sit e ha s bee n affecte d b y thes e activities

. Lak e Count y i s relativel y smal l (38 0 squar e miles ) and predominatel y rura l count y wit h a 199 0 populatio n o f 6,00 7 (U.S

. Departmen t o f Commerce
, 1990)

. Approximatel y hal f o f the populatio n resid e within th e Cit y o f Leadville

. Th e populatio n o f Lake Count y ha s fluctuate d wit h th e minin g industry

. Th e populatio n increased t o approximatel y 9,000 betwee n 196 0 an d 198 1 an d the n decline d throughou t the 1980s

. Approximatel y two-third s o f the lan d i n Lak e Count y i s federall y owned , an d i s par t o f Sa n Isabe l Nationa l Fores t o r i s managed b y th e Burea u o f Land Management

. Lan d surroundin g an d within Californi a Gulc h i s predominatel y dedicate d t o mining , commercial , an d residentia l uses
. A n unimprove d dir t roa d run s fro m th e hairpi n turn o n Lak e Count y Roa d 2 alon g Californi a Gulc h t o th e Garibald i Min e site

. N o othe r improvement s exist a t th e Garibald i site

. 

### 2.1. 8 Sensitiv e Ecosystems Previou s investigation s revea l tha t th e occurrenc e o f threatened , endangere d o r sensitiv e specie s i n th e terrestria l ecosyste m i s unlikel y (WCC
, 1993b)

. However
, erosion o f tailin g materia l an d contaminate d strea m sedimen t contribut e heav y meta l loadin g t o Californi a Gulch and the Arkansa s River

. Thes e releases potentiall y affec t th e aquati c ecosystem

. 

### 2.1. 9 Climat e The climat e o f Lake Count y i s relativel y dry , but i s otherwis e typica l o f mos t alpin e region s i n the souther n Rock y Mountains

. The averag e annua l maximu m temperatur e i n the Leadvill e are a i s 50. 5 degrees Fahrenhei t an d th e averag e annua l minimum temperatur e i s 21. 9 degrees 

### Fahrenheit
, wit h a n annua l mea n temperatur e o f 37. 3 degrees Fahrenheit

. Precipitatio n occur s throughou t the yea r wit h the mos t significan t precipitatio n occurrin g a s rai n i n the summe r month s o f Jul y an d August

. Precipitatio n varie s throughou t Lake Count y i n relatio n t o the elevation

. The south-centra l portio n o f the count y at an elevatio n nea r 9,00 0 fee t AMSL
, receive s abou t 1 0 inche s o f precipitatio n annually

. A t highe r elevation s precipitatio n ca n reac h 4 0 inche s pe r year . Th e mea n annua l snowfal l range s fro m 13 4 inche s a t th e lowe r
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__________________________________ FINAL * EE/CA Garibaldi Mine Site » 10 elevation s t o 27 1 inche s a t th e highe r elevations

. Th e win d i s predominantl y fro m th e northwest , wit h speed s typicall y fro m 0 t o 3 0 mp h (WCC
, 1993a)

. 

### 2.1.1 0 Histori c an d Cultura l Resource s A cultura l resource surve y wa s conducte d b y Goodso n and Associates
, Inc.
, (Martorano
, 1990 ) prio r t o implementatio n o f sit e improvement s b y th e Resurrection/ASARC O

Join t Ventur e in 1990

. Th e objectiv e o f th e surve y wa s t o identify
, record , an d provid e evaluation s o f th e histori c an d prehistori c resource s whic h coul d hav e bee n affecte d b y th e sit e improvements

. Th e primar y tasks include d a literatur e an d record s search , an d intensiv e pedestria n surve y o f area s potentiall y impacted , dat a analysis , an d preparatio n o f a report

. A n assessment o f effec t i s require d fo r al l resource s determine d eligibl e fo r o r liste d in th e Nationa l Registe r o f Histori c Place s (NRHP)
, an d locate d withi n th e Are a o f Potentia l Effec t (APE)

. T h e 1990 cultura l resource investigation s a t th e Garibald i Min e Sit e (OU4 ) resulte d i n th e recordatio n an d documentatio n o f th e Garibald i Min e as sit e 5LK805

. Thi s resource , 5LK805
, w a s officiall y determine d no t eligibl e fo r listin g i n th e NRH P b y th e Stat e Histori c Preservatio n Offic e (SHPO)
, o n Augus t 31 , 1990 (se e Appendi x A)

. Unde r Sectio n 10 6 o f th e Nationa l Histori c Preservatio n act o f 196 6 (a s amended)
, no assessment o f effec t i s required fo r resource s determine d no t eligibl e fo r th e NRHP

. N o furthe r cultura l resource investigation s ar e require d prio r t o implementatio n o f ground-disturbin g activities

. Suc h actions ar e considere d t o hav e n o effec t o n histori c properties , provide d th e Are a o f Potentia l Effec t (APE ) does no t exten d beyon d th e are a previousl y surveyed

. Additiona l cultura l resource investigation s woul d be require d fo r an y propose d action s outsid e o f th e area s previousl y surveyed

. 2 . 2 PREVIOU

S REMOVA L ACTION S I n 1990/1991
, th e Resurrection/ASARC O

Join t Ventur e constructe d run-o n diversio n channel s aroun d th e wast e roc k pil e an d a porta l discharg e diversio n (WCC
, 1990)

. Th e inten t o f th e sit e improvement s wa s t o reduc e the volum e an d mobilit y o f contaminate d material b y minimizin g the water infiltrating int o and out o f the min e workings and wast e roc k pile

. Th e mai n improvemen t fo r thi s sit e wa s th e regradin g o f th e dir t roa d abov e th e Garibald i tunne l portal

. Th e roa d wa s reconstructe d t o conve y stormwate r o n th e uphil l par t (norther n side ) o f th e roa d instea d o f allowin g th e water t o flo w acros s th e roa d an d downhil l int o th e min e wast e roc k area . The ditche s wer e designe d fo r a 25-yea r 6-hou r stor m event

. Th e existin g profil e o f th e roa d di d no t change an d remained relativel y fla t wit h a smal l ditc h
on th e uphil l side

. Th e roa d wa s regrade d t o b e uniforml y slopin g a t approximatel y 3 t o 5 % dow n towar d th e uphil l side

. Approximatel y tw o fee t awa y fro m th e cente r o f th e uphil l ditch , th e downward slop e o f th e roa d (alon g th e cross-sectiona l dimensio n a t th e beginnin g o f th e ditch ) wa s increased

. The cut slop e o f the existin g hil l nort h and wes t o f the roa d wa s maintaine d or flattene d t o approximatel y 1: 2 ( 1 horizonta l t o 2 vertical)

. The botto m o f the ditc h wa s constructe d t o b e a t leas t one foo t wid e and the to p a t leas t 3 fee t wide

. The ditc h
wa s terminate d downhil l fro m the wast e pil e a s indicate d on Drawin g 1

. Flo w i s diverte d int o a culvert whic h carrie s i t unde r th e roa d an d discharges i t dow n th e hil l belo w th e bas e o f th e wast e pile

. Th e outfal l are a wa s protecte d fro m erosio n wit h riprap

.

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_________________________________ FINAL * EE/CA Garibaldi Mine Site » 11 T o diver t runof f fro m th e hillsid e eas t an d southeas t o f th e min e waste , a ditc h was construae d alon g the sout h sid e o f the pile , nea r the southwesterl y en d o f the wast e pil e an d extende d t o t h e porta l o f th e Garibald i tunnel

. Riprap
, geotextile , grass , and/o r straw wer e use d t o protec t t h e ditc h fro m erosion

. Th e flo w fro m Garibald i tunne l i s diverte d int o th e ne w ditch

. Th e flo w i s the n route d unde r th e roa d b y culver t t o th e ditc h runnin g paralle l t o th e road

. Th e siz e o f this ditc h i s th e sam e as describe d abov e fo r th e ditc h adjacen t t o th e road

. Thes e sit e improvement s wer e expecte d t o reduc e th e amoun t o f run-o n t o th e wast e pil e an d thu s reduc e infiltratio n int o th e wast e pil e i n th e min e workings are a b y divertin g run-o n aroun d this area . I t was anticipate d tha t th e quantit y o f poo r qualit y water seepin g fro m th e min e workings int o Californi a Gulc h woul d be reduced

. Recen t surfac e wate r dat a indicates , however, tha t th e Garibald i wast e roc k an d min e porta l continu e t o contribut e t o surfac e wate r contaminatio n (acidic p H levels ; elevate d heav y meta l loadings ) in Uppe r Californi a Gulch

. 2 . 3 SOURCE
, NATURE
, AN D EXTEN T O F CONTAMINATIO N 

### 2.3. 1 Identificatio n o f Source s o f Hazardou s o r Contaminatin g Substance s Thi s EE/C A addresse s mitigatio n o f th e Garibald i Min e site

. Th e majo r sourc e o f contaminatio n a t thi s sit e i s th e wast e roc k pile

. Runof f fro m sprin g snowmel t an d stor m events , an d flo w fro m th e Garibald i porta l hav e leache d meta l contaminant s fro m th e wast e rock , an d consequentl y increase d th e meta l loadin g t o Uppe r Californi a Gulch

. Laborator y analyse s o f th e surfac e wast e roc k materia l collecte d a t th e Garibald i Min e sit e (Fal l 1994 ) confirm s that the wast e roc k ha s the potentia l t o generat e aci d roc k drainag e an d releas e metals

. Thi s i s furthe r discusse d in th e followin g section

. 

### 2.3. 2 Characteristic s o f Sourc e Fiel d reconnaissanc e o f th e wast e roc k pile s within Uppe r Californi a Gulch was conducte d i n Augus t 199 3 (SMI/TerraMatrix
,

1994a ) an d Septembe r 199 4 (TerraMatrix/SM I 1995)

. Th e investigation s indicate d tha t th e Garibald i wast e roc k pil e cover s a surfac e are a o f approximatel y 1. 6 acres, ha s a n averag e heigh t o f approximatel y 3 5 fee t an d contain s a volum e o f approximatel y 27,90 0 cubi c yard s o f material

. Th e fac e angl e o f th e wast e roc k pil e i s approximatel y 32-3 5 degrees

. Th e wast e roc k i s primaril y coars e t o fin e grained materia l an d n o vegetatio n i s present o n th e pile

. Th e wast e roc k pil e i s withi n th e Uppe r Californi a Gulc h drainag e an d include s th e Xmas
, N o Name
, Ohi o Bonanza
, an d Lad y Crawfor d claims

. Laboratory analysi s o f a composit e sampl e collecte d fro m th e Garibald i wast e roc k pil e in fal l 199 4 confirme d tha t surfac e materia l o n the min e wast e pil e ha s the potentia l t o generat e aci d
an d leac h metals

. Th e followin g analyse s wer e performe d o n th e sample : * • Acid-Bas e Accountin g (ABA ) tes t • Syntheti c Precipitatio n Leachin g Procedur e (EP A Metho d 1312 ) • Tota l Metal s Analysi s • Grai n siz e 

### Result s o f thes e analyses ar e presente d i n Tabl e 1 , Garibald i Min e Wast e Geochemica l Data
, an d
ar e discusse d below

.

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27, 1995 FINAL * EE/CA Garibaldi Mine Site » 12

TABL E 1 GARIBALD I WAST E ROC K DAT A (Sampl e Site UCG- 1 21) Octobe r 199 4 A B A Analysi s Sulfur
, S0 4 (% ) Sulfur
, Pyr

. & Org.(%) Sulfur
, Tota l {% ) A G P (T/KT ) Neutralizin g Potentia l (% CaC0 3 ) A N P (T/KT ) A B P (T/KT ) 131 2 Analysi s Arseni c Cadmiu m Calciu m Iro n Lea d Magnesiu m Mercur y Potassiu m Sodiu m Zin c p H Alkalinit y T D S Chlorid e Sulfat e Tota l Metal s Arseni c Cadmiu m Lea d Zin c Textur e San d (%) Sil t (% ) Cla y (% ) Textur e Classificatio n 0.8 4 1.5 9 2.4 3 75. 9 0. 1 0 -75. 9 Concentratio n (mg/L ) 0.001 5 0.03 4 19.1 1 10. 3 4.5 9 5.0 5 < 0.000 2 1.7 8 2.5 8 6.2 4 2. 9 2 25 4 1 34 5 Concentratio n (mg/kg ) 1 1 5 0.6 1 3,570 38 2

6 0 19 2 1 S C L

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__________________________________ FINAL * EE/CA Garibaldi Mine Site » 13 T h e AB A tes t i s a commonly-use d metho d t o evaluat e th e potentia l o f a materia l t o generat e acid

. Th e tes t involves measurin g an d comparin g a sample' s maximu m aci d productio n potentia l ( A P o r AGP ) wit h it s maximu m neutralizatio n potentia l (N P o r ANP)

. Th e differenc e betwee n A P an d N P i s referre d t o a s th e Aci d Bas e Potentia l (ABP ) o r Ne t Neutralizatio n Potentia l (NNP)

. A s state d i n the draf t technical documen t Acid Mine Drainage Prediction, (EPA
, 1994) : I f th e differenc e betwee n (ANP ) an d (AGP ) i s negativ e the n th e potentia l exist s fo r th e wast e t o for m acid

. I f i t i s positiv e the n ther e ma y b e lowe r risk

. Predictio n o f th e aci d potentia l whe n th e (ABP ) i s betwee n -2 0 an d 2 0 ( T CaCO3/KT ) is mor e difficult (EPA
, 1994)

. T h e AB P o f th e sampl e collecte d fro m Garibald i wa s -75. 9 ( T CaCO3/KT)
, indicatin g tha t surfac e material on the min e wast e pil e ha s a hig h potentia l t o for m acid

. T o evaluat e th e potentia l o f thi s materia l t o leac h metal s whe n contacte d wit h precipitation , th e sampl e was analyze d b y EP A Metho d 1312

. Thi s tes t involve s mixin g a sampl e wit h a syntheti c rainwate r solutio n an d analyzin g th e leachat e tha t i s generate d fo r metal s an d othe r contaminant s o f concern . Althoug h th e metal concentration s measured i n th e leachat e canno t be directl y compare d t o th e concentration s tha t woul d occu r i n sit e runof f due

. t o difference s i n sampl e dilution , th e result s d o giv e a n indicatio n o f whic h constituent s ma y b e elevated

. T h e leachat e fro m th e surfac e materia l collecte d fro m Garibald i wa s strongl y acidic (p H 2.9 ) an d containe d elevate d concentration s o f cadmiu m (0.03 4 mg/1)
, iron (10. 3 mg/1)
, lea d (4.5 9 mg/1)
, sulfat e (34 5 mg/1 ) an d zin c (6.24 mg/1)

. Wit h th e exceptio n o f lead , thes e leachat e characteristic s ar e comparabl e t o th e qualit y o f see p sample s collecte d a t th e to e o f th e min e wast e pil e an d surfac e wate r sample s collecte d i n Californi a Gulc h downstrea m o f Garibaldi

. Lea d concentration s i n th e see p an d downgradien t surfac e wate r sample s wer e significantl y lowe r (0.00 2 t o 0.02 9 mg/1 ) tha n i n th e leachat e sampl e (4.5 9 mg/1)
, suggestin g tha t i f this meta l i s leache d fro m th e surfac e materia l a t th e site , i t i s significantl y attenuate d withi n and/o r immediatel y downgradien t o f th e min e wast e pile

. Conversely
, th e concentratio n o f arseni c i n th e leachat e sampl e wa s relativel y lo w (0.0015 mg/1 ) compare d t o concentration s observe d i n th e to e see p and downgradien t surfac e water sample s (0.01 0 t o 0.08 4 mg/1)

. Thi s ma y sugges t a source o f arseni c occur s within , o r immediatel y downgradien t of
, th e Garibald i min e wast e pile

. I n additio n t o AB A an d leachin g tests , th e composit e sampl e collecte d fro m Garibald i wa s analyze d fo r th e tota l concentratio n o f fou r metal s (arsenic
, cadmium , lead , an d zinc)

. Tota l meta l analyse s wer e performe d t o verif y the sourc e o f som e o f the metal s measured i n the sampl e leachat e an d t o asses s potentia l ai r an d water loadin g effect s shoul d surfac e materia l a t th e sit e be disturbe d durin g reclamatio n activities

. Th e surfac e materia l a t Garibald i containe d 11 5 mg/k g tota l arsenic , 0.6 1 mg/k g tota l cadmium , 3,57 0 mg/k g tota l lead , an d 38 2 mg/k g tota l zinc

. Finally
, for use i n potentia l reclamatio n and geotechnical evaluations , a grai n siz e analysi s wa s performe d o n th e surfac e materia l a t Garibaldi

. Th e materia l wa s foun d t o contai n th e following grai n size fractions : 

### • San d (60% ) • Sil t (19% ) • Clay (21% )

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27, 1995 FINAL * EE/CA Garibaldi Mine Site * 14 Not e tha t thes e percentage s reflec t th e grai n siz e distributio n o f th e fine r materia l expose d o n th e surfac e o f th e pil e tha t was sample d fo r geochemica l analysis

. Coarse r materia l suc h as gravels , cobbles , an d boulder s wer e no t use d t o prepar e th e composit e sample

. 

### 2.3. 3 Physica l an d Chemica l Attribute s o f Contaminatio n Surfac e wate r samplin g and analyse s hav e bee n conducte d at severa l monitorin g location s i n the vicinit y o f th e Garibald i Min e sit e (WWL
, 1990 an d SMI
, 1994 ; SMI/TerraMatrix
,

1994b ; SMI/TerraMatrix
, 1995a)

. Monitorin g activitie s wer e conducte d a t th e following sites : Californi a Gulch t o the southeast an d upstrea m o f the Garibald i Min e sit e (CG-17 ) Californi a Gulc h t o th e northwest an d upstrea m o f th e Garibald i Min e sit e (CG-1F ) Garibald i Portal (GP-1 ) Garibald i wast e roc k pil e to e see p (GM-1 ) Californi a Gulch directl y downstrea m o f th e Garibald i Mine sit e (CG-16 ) Californi a Gulch downstream o f the Garibald i Min e sit e at Count y Roa d 2 (CG-1G ) I n addition , groundwate r samplin g an d analyses hav e bee n conducte d a t a shallo w alluvia l wel l locate d in th e eas t drainag e abov e th e Garibald i Min e site

. Th e wel l (GMW1W ) was installe d i n October 199 4 t o investigat e th e presenc e o f groundwate r a t th e site

. Monitorin g location s ar e presente d i n Drawin g 1

. Surfac e water dat a ar e presente d in Tabl e 2 , Surfac e Wate r Analysis - Californi a Gulc h Upstrea m o f Garibald i Min e Site ; Tabl e 3, Surfac e Wate r Analysi s - Garibald i Portal ; Tabl e 4 , Surfac e Wate r Analysi s - Garibald i Wast e Roc k Pil e (To e Seep) ; an d Tabl e 5 , Surfac e Wate r Analysi s - Californi a Gulc h Downstrea m o f Garibald i Min e Site

. Groundwate r dat a ar e presente d in Tabl e 6 , Garibald i Groundwate r Analysis

. Surfac e and groundwate r qualit y sample s wer e collecte d a t 3 monitorin g stations locate d upgradien t o f th e Garibald i Min e site ; CG-17
, CG-1F
, an d GMW1W

. Analysi s o f th e sample s indicate d th e following concentratio n range s fo r selecte d constituents : Alkalinit y - 7 t o 7 6 mg/ 1 (a s CaCO3) ; Sulfat e (D )
- 13 t o 103 mg/1 ; TD S
- 3 2 t o 23 8 mg/1 ; pH (field )
- 6.3 4 t o 6.75 ; Arsenic (D )
- < 0.00 1 t o < 0.00 5 mg/1 ; Cadmiu m (D )
- < 0.00 5 t o 0.00 2 mg/ 1 Chromiu m (D )
- < 0.00 5 mg/1 ; Coppe r (D )
- < 0.00 5 t o <0.0 1 mg/1 ; Iro n (D )
- <0.0 1 t o 0.0 7 mg/1 ; 

### Lead (D )
- < 0.00 1 t o < 0.00 5 mg/1 ; Manganes e (D )
- < 0.00 5 t o 0.0 5 mg/1 ; Nicke l (D)

- <0.0 1 mg/1 ; Seleniu m (D )
- < 0.00 5 mg/1 ; Silve r (D )
- < 0.000 2 t o < 0.00 5 mg/1 ; and , Zin c (D )
- 0.0 8 t o 0.3 7 mg/1

.

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27, 1995 FINAL * EE/CA Garibaldi Mine Site * 15 TABL E 2 SURFAC E WATE R ANALYSI S
- CALIFORNI A GULCH UPSTREA M O F GARIBALD I MIN E SIT E Locatio n Dat e Sourc e Flo w (cfs ) Cd- D Cd- T Cu- D Cu- T Pb- D Pb- T Zn- D Zn- T AI- D AI- T As- D As- T Ba- D Ba-T Bi- D Bi- T Cr- D Cr- T Fe- D Fe- T Mn- D Mn- T Ni- D Ni- T Se- D Se- T Ag- D Ag- T Sr- D Sr- T Ca- D Ca- T Mg- D Mg- T Na- D Na- T K - D CG-1 7

06/09/8 9 W W L 0.005 3 <0.00 5 <0.00 5 <0.00 5 <0.00 5 <0.00 5 <0.00 5 0.1 8 0.1 7 <0. 1 <0. 1
< 0.00 5
< 0.00 5 0.0 5 <0.0 5 <0. 5 <0. 5 <0.00 5 <0.00 5 <0.01 0.0 3 <0.00 5 <0.00 5 <0.01 <0.01 <0.00 5
< 0.00 5
< 0.00 5 <0.00 5 0.0 2 0.0 2 8. 4 7. 6 1. 4 1. 3 0. 4 0. 4 0. 7 GMG- 1 06/09/8 9 W W L 0.004 3
< 0.00 5 <0.00 5
< 0.00 5
< 0.00 5
< 0.00 5
< 0.00 5 0.03 1 0.04 5 <0. 1 0. 2
< 0.00 5
< 0.00 5 0.0 9

^

_ 0.0 8 <0. 5 <0. 5
< 0.00 5 <0.00 5 0.0 4 0.26
< 0.00 5 0.00 9 <0.01 <0.01
< 0.00 5
< 0.00 5
< 0.00 5
< 0.00 5 0.0 2 0.0 2 6 5. 4 0.6 6 0.6 3 0. 7 0. 6 0. 6 CG-1 7

AN D GMG- 1 10/26/8 9 W W L DR Y CG-1 F

05/26/9 4 S M I 0.4 5 0.000 6 0.000 6 <0.01 <0.01 <0.00 1 0.00 3 u(uj ) 0.0 8 0.0 9 u 0.1 9 0.1 9 <0.00 1 <0.00 1
n a n a n a n a n a n a 0.0 7 0.0 8 u 0.0 4 0.0 4
n a n a n a n a <0.000 5
< 0.000 5 u j
n a n a 5. 4
n a 0.8 0.8 0. 6
n a n a CG-1 F 10/05/9 4 S M I DR Y

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27, 1995 FINAL * EE/CA Garibaldi Mine Site * 16 TABL E 2 (cont'd ) SURFAC E WATE R ANALYSI S
- CALIFORNI A GULCH UPSTREA M O F GARIBALD I MIN E SIT E Locatio n Dat e Sourc e K - T Si- D Si- T CI- D CI- T F - D F - T CN- T Acidit y S 0 4 - T (filt ) S 0 4 - T (unfilt ) Alkalinity- T (filt ) Alkalinity- T (unfilt ) Carbonate- D Carbonate- T Bicarbonate- D Bicarbonate- T p H (lab) p H (lab-filt ) p H (lab-unfilt ) Spec

. Cond

. (lab ) p H (field ) Spe c Con d (field ) T D S T S S Tem p (C° ) CG-1 7

06/09/8 9 W W L 0. 6 5. 3 5. 0
<3
<3 <0. 5 <0. 5
< 0.00 5 0.0 4 1 6 2 0
n a 7
< 5
< 5 9 9 6. 9
n s n s 7 6 6.3 4 6 6 5 6
< 5 2. 2 GMG- 1 06/09/8 9 W W L 0. 5 4 3. 3
<3
<3 <0. 5 <0. 5 <0.00 5 0.0 4 1 3 1 4
n a 1 0
< 5
< 5 1 2 1 2 6. 9
n s n s 4 7 6.6 5 4 4 4 0
< 5 4. 6 CG-1 7

AN D GMG- 1 10/26/8 9 W W L CG-1 F

05/26/9 4 S M I

n a n a n a n a n a n a n a n a n a 1 5 1 2 13 8
n a n a n a n a n s 6.82 J 6.8 5 j
n a 6.7 5 50 3 3 2
n a 4. 3 CG-1 F 10/05/9 4 S M I

Concentratio n i n mg/l ; discharg e i n cfs ; p H i n standar d units ; specifi c conductanc e i n ^/mhos/cm ; acidit y i n meq/l

. T = Tota l n

a = no t analyze d D = Dissolve d u

= not detecte d n s = no t specifie d j = dat a estimate d CG-1 7 = Californi a Gulc h t o S E above Garibald i CMG- 1 = Californi a Gulc h t o N E above Garibald i (sit e know n a s CG-1 F afte r 1993 )

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27 , 1995 FINAL * EE/CA Garibaldi Mine Site 4 17 TABL E 3 SURFAC E WATE R ANALYSI S
- GARIBALD I PORTA L Locatio n Dat e Sourc e Flo w (cfs ) Cd- D Cd- T Cu- D Cu- T Pb- D Pb- T Zn- D Zn- T AI- D AI- T Sb- D Sb- T As- D As- T Ba- D Ba- T Be- D Be- T Bi- D Bi- T Cr- D Cr- T Fe- D Fe- T Mn- D Mn- T Hg- D Hg- T Mo- D Mo- T Ni- D Ni- T Se- D Se- T Ag- D Ag- T Sr- D Sr- T Ti- D Ti- T Ca- D Ca- T Mg- D Mg- T GM- 1

[WWL ] 06/09/8 9 W W L 0.012 8 0.01 1 0.01 1 0.01 9 0.01 9 < 0.00 5 < 0.00 5 1. 7 1. 6 0.3 0. 2 n a n a <0.00 5 <0.00 5 <0.0 5 <0.0 5 n a n a <0. 5 <0. 5 < 0.00 5 < 0.00 5 <0.0 1 0.0 3 1. 5 1. 4 n a n a n a n a <0.0 1 0.01 <0.00 5 <0.00 5 <0.00 5 <0.00 5 0.0 5 0.0 5 n a n a 2 0 1 9 3. 8 3. 6 GM- 1 [WWL ] 10/26/8 9 W W L 0.001 1 0.00 9 0.00 9 0.01 8 0.02 8 0.00 9 0.014 1. 2 1. 2 0. 3 0.4 n a n a <0.00 5 < 0.00 5 <0.0 5 <0.0 5 n a n a n a n a <0.00 5 <0.00 5 <0.0 1 0.2 5 1. 8 1. 7 n a n a n a n a <0.01 <0.0 1 < 0.00 5 < 0.00 5 <0.00 5 < 0.0.0 5 0.0 4 0.0 5 n a n a n a 2 1 n a 4. 4 TP- 2 10/16/9 1 W C C 0.002 5 0.011 6 u 0.010 2 b 0.0 5 b 0.0 5 b 0.008 8 0.010 3 1.3 9 1.05n 0.33 4 0.385 0.12 b 0.12 u 0.0 2 u 0.0 2 u 0. 4 b e 0. 4 b 0.01 u 0.01 u n a n a 0.0 2 u 0.0 2 u 0. 2 u 0. 2 b 1.6 7 1.7 9 0.000 2 u 0.000 2 u 0.0 4 u 0.0 4 u 0.0 8 b 0.0 8 b 0.0 1 u

, n a 0.0 2 u 0.0 2 u n a n a 0.0 1 u 0.0 1 b
n a 2 3 n a 5 TP- 2 09/15/9 2 W C C 0.003 3 0.02 4 0.0257 0.088 2 0.077 8 0.006 8 0.008 9 3.5 9 2.9 9 e 0.43 1 0.46 7 0.0 6 b 0.1 2 u 0.0 1 u 0.0 2 b 0. 2 b 0. 4 b 0.00 5 u 0.00 5 u n a n a 0.01 u 0.0 2 u 0. 1 u 0. 1 b 2.0 6 1.8 8 0.0002. U 0.000 3 0.0 2 u 0.0 4 u 0.0 4 b 0.0 8 b 0.00 5 u 0.01 u n 0.01 u n 0.0 2 u n a n a 0.0 1 b 0.0 1 b
n a 2 6 n a 5 u GP- 1 05/26/9 4 S M I 0.0 8 0.01 2 0.01 2 0.0 6 j 0.0 5 j 0.00 9 0.01 6 1. 6 1. 5 0.4 5 j 0.3 8 j n a n a <0.00 1 0.00 1 n a n a n a n a n a n a n a n a 0.0 8 0.1 6 u 0. 9 0.87 n a n a n a n a n a n a n a n a <0.00 5 <0.00 5 u j n a n a n a n a 13. 7
n a 2. 6 2. 5 GP- 1 10/05/9 4 S M I 0.00 1 0.003 3 j 0.01 8 j 0.0 5 j 0.0 4 j 0.00 8 0.03 7 2.0 5 1.8 8 0.5 5 1.4 8 n a n a <0.00 1 u j 0.00 4 u n a n a n a n a n a n a n a n a 0.0 2 u 1.5 4 1.8 3 1.8 4 n a n a n a n a n a n a n a n a < 0.000 5 0.001 2 n a n a n a n a 2 2 n a 5 j 4 j

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27, 1995 FINAL *EE/CA Garibaldi Mine Site * 18 TABL E 3 (con f d ) SURFAC E WATE R ANALYSI S
- GARIBALD I PORTA L Locatio n Dat e Sourc e Na- D Na- T K - D K - T Si- D Si- T CI- D CI- T F - D F - T CN- D CN- T Acidit y Alkalinity- T (filt ) Alkalinity- T (unfilt ) Carbonate- D Carbonate- T Bicarbonate- D Bicarbonate- T NO3/NO 2 S 0 4 (unfilt ) S 0 4 (filt ) P0 4 - T p H (lab ) p H (lab-filt ) p H (lab-unfilt ) Spec

. Cond

. (lab ) p H (field ) Spe c Con d (field) T S S T D S Tem p (°C ) GM- 1

[WWL ] 06/09/8 9 W W L 0. 7 0. 6 1. 2 1. 0 4. 4 3. 8 <3 <3 <0. 5 <0. 5 n a <0.00 5 0.2 6 n a < 5

< 5 < 5 < 5 < 5 n a 7 0 6 7 n a 4. 7 n s n s 20 0 4.5 7 19 8

<5 13 0 2. 9 GM- 1 [WWL ] 10/26/8 9 W W L
n a 0. 8 n a 1. 2 n a 3. 3 n a < 3 n a <0. 5 n a <0.00 5 0.2 2 n a < 5

n a < 5 n a < 5 n a 8 6 n a n a 4.4 n s n s 19 0 4.5 2 26 0 6 13 0 3. 1 TP- 2 10/16/9 1 W C C

n a 5 u n a 5 u n a 9 1 u n a 0. 1 u n a n a 0.0 1 u n a n a 2

n a n a n a n a 0.0 7 8 8 n a 0.0 1 u 4. 7
n s n s 22 9 4.44 202 2
2 u 12 4 3. 9 TP- 2 09/15/9 2 W C C
n a 5 u n a 5 u n a 1 2 5 u n a 0. 2
n a n a 0.0 1 u n a n a n a

n a n a n a n a 0.1 4 8 0 n a 0.01 u 4. 6 n s n s 19 8 4.5 23 6 6 156 4. 1 GP- 1 05/26/9 4 S M I 0. 7 n a n a n a n a n a n a n a n a n a n a n a n a < 5 < 5

n a n a n a n a n a 4 7 5 2 j n a n s 4.7 2 j 4.7 3 j n a 5.3 9 14 2

n a 8 8 3. 3 GP- 1 10/05/9 4 S M I
< 1 n a 1 n a n a n a < 1 n a n a n a n a n a n a n a 0

n a 0 n a 0 n a n a 7 6 n a n s n a 4. 6 j n a 4.5 3 22 0

n a 13 8 4. 9 Concentratio n i n mg/l ; discharg e i n cfs ; p H i n standar d units ; specifi c conductanc e i n //mhos/cm ; acidit y i n meq/l

. T = Tota l n

a = no t analyze d j = dat a estimate d D = Dissolve d u

= not detecte d n s = not specifie d n = not validate d e = interferenc e b = belo w detectio n limi t

1 Tabl e 2.1- 5 o f th e Draf t Hydrogeologi c Rl list s p H a s 4.41 , whil e Tabl e 4.2-9 a list s p H a s 4.4 4 2 Tabl e 2.1- 5 o f th e Draf t Hydrogeologi c R l list s Spec

. Cond

. a s 202 , whil e Tabl e 4.2-9 a list s Spec

. Cond

. a s 21 5 GM- 1 [WWLJ
, TP-2
, an d GP- 1 al l ar e Garibald i Porta l monitorin g samples

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27, FINAL * EE/CA Garibaldi Mine Site * 19 TABL E 4 SURFAC E WATE R ANALYSI S
- GARIBALD I WAST E ROC K PIL E (TO E SEEP ) Locatio n Dat e Sourc e Flo w (cfs ) Cd- D Cd- T Cu- D Cu- T Pb- D Pb- T Zn- D Zn- T AI- D AI- T As- D As- T Ba- D Ba-T Bi- D Bi- T Cr- D Cr- T Fe- D Fe- T Mn- D Mn- T Ni- D Ni- T Se- D Se- T Ag- D Ag- T Sr- D Sr- T Ca- D Ca- T Mg- D Mg- T Na- D Na- T K - D K - T Si- D GMD- 1

06/09/8 9 W W L N O T SAMPLE D GMD- 1 10/26/8 9 W W L 0.002 2 0.08 3 0.08 4 0.7 2 0. 9
< 0.00 5
< 0.00 5 1 5 1 5 1 2 1 4 0.05 8 0.0 7 <0.0 5 <0.0 5
n a n a < 0.00 5
< 0.00 5 4 4 4 3 1 1 1 1 0.0 2 0.0 2
< 0.00 5
< 0.00 5
< 0.00 5
< 0.00 5 0.0 5 0.0 5
n a 2 2
n a 7
n a 1. 5 n a 0.5
n a GM- 1 05/27/9 4 S M I 0.2 5 0.051 5 0.10 1 1.1 1 j 0.9 7 j 0.02 9 0.0 4 10. 8 17. 7 14. 1 j 12.5 J 0.08 4 j 0.05 6 j
n a n a n a n a n a n a 31. 2 5 8 6.1 5 10. 4
n a n a n a n a < 0.000 5
< 0.000 5 u j
n a n a 24. 8 n a 8. 2 7. 5 8. 8
n a n a n a n a GM- 1 10/05/9 4 S M I 0.00 4 0.011 9 j 0.11 8 j 1.1 7 1.1 2 0.00 2 0.007 22 1 22 4 18. 2 17. 4 0.06 8 j 0. 1 1 j
n a n a n a n a n a n a 53. 9 54. 2 13. 0 12. 9
n a n a n a n a < 0.000 5
< 0.000 5
n a n a 2 5
n a 8 8 2
n a < 1
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27, 1995 FINAL * EE/CA Garibaldi Mine Site * 20 TABLE 4 (con f d ) SURFAC E WATE R ANALYSI S
- GARIBALD I WAST E ROC K PIL E (TO E SEEP ) Locatio n Dat e Sourc e Si- T CI- D CI- T F - D F - T CN- T Acidit y Alkalinity- T (filt ) Alkalinity- T (unfilt ) Carbonate- D Carbonate- T Bicarbonate- D Bicarbonate- T S 0 4 (unfilt ) S 0 4 (filt ) p H (lab) p H (la b filt ) p H (la b unfilt ) Spec

. Cond

. (lab ) p H (field ) Spe c Con d (field ) T D S T S S Tem p (C° ) GMD- 1

06/09/8 9 W W L GMD- 1 10/26/8 9 W W L 1 4
n a < 3
n a <0. 5 <0.00 5 5. 6
n a < 5
n a < 5
n a < 5
n a 40 0 3. 0
n s n s 98 0 2.7 6 1,21 1 55 0 8 4. 0 GM- 1 05/27/9 4 S M I

n a n a n a n a n a n a n a < 5 u < 5 u n a n a n a n a 41 6 41 8
n s 2.8 5 j 2.8 9 j
n a 3.2 2 1,23 0 67 5 j
n a 2. 3 GM- 1 10/05/9 4 S M I

n a < 1
n a n a n a n a n a 0
n a n 0
n a 0
n a 335 n s n s 2. 9 j
n a 2.8 5 730 59 6
n a 6. 7 Concentratio n i n mg/l ; discharg e i n cfs ; p H i n standar d units ; specifi c conductanc e in /t/mhos/cm ; acidit y in meq/l

. T = Tota l na = not analyze d j = dat a estimate d D = Dissolve d u = not detecte d n s = not specifie d GM- 1 = Garibald i Wast e Roc k Pil e (To e Seep)
, (know n a s GMD- 1 prio r t o 1994 )

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27, 1995 FINAL *EE/CA Garibaldi Mine Site * 21 TABL E 5 SURFAC E WATE R ANALYSI S
- CALIFORNI A GULC H DOWNSTREA M O F GARIBALD I MIN E SIT E Locatio n Dat e Sourc e Flo w (cfs ) Cd- D Cd- T Cu- D Cu- T Pb- D Pb- T Zn- D Zn- T AI- D AI- T As- D As- T Ba- D Ba- T Bi- D Bi- T Cr- D Cr- T Fe- D Fe- T Mn- D Mn- T Ni- D Ni- T Se- D Se- T Ag- D

. Ag- T Sr- D Sr- T Ca- D Ca- T Mg- D Mg- T Na- D Na- T K - D K - T Si- D Si- T CI- D CG-1 6

06/09/8 9 W W L 0.034 8 0.08 3 0.07 8 0.7 8 0.8 2 0.018 0.02 3 1 7 1 6 1 1 1 1 0.04 4 0.04 5 <0.0 5 <0.0 5 <0. 5 <0. 5 <0.00 5 <0.00 5 6 3 6 0 9. 1 8. 4 0.0 2 0.0 2
< 0.00 5 <0.00 5 < 0.00 5 <0.00 5 0.0 5 0.0 5 2 4 2 2 6. 7 6. 6 0. 7 0. 8 0.5 0.4 9. 8 9. 2
<3 CG-1 5 06/09/8 9 W W L 0.088 9 0.1 2 0.1 1 1. 1 1. 0 0.0 2 0.02 1 2 0 2 0 2 7 2 6 <0.00 5 <0.00 5 <0.0 5 <0.0 5 <0. 5 <0. 5 < 0.00 5 <0.00 5 4. 6 4. 5 9.9 9. 6 0.0 5 0.0 5 <0.00 5
< 0.00 5
< 0.00 5 < 0.00 5 0.0 9 0.0 9 4 1 3 9 1 4 1 3 1. 6 1. 4 1. 5 1. 3 2 0 1 8 <3 CG-1 6 AN D CG-1 5 10/26/8 9 W W L DR Y CG-1 G 05/27/9 4 S M I 0. 8 0.07 5 0.07 8 0.7 4 0.6 9 0.01 6 0.01 7 13. 5 12. 8 14. 1 j 13. 4 0.01 j 0.00 8 j
n a n a n a n a n a n a 14. 8 15. 6 6.8 5 6.7 6 n a n a n a n a < 0.000 5 < 0.000 5 u j n a n a 24. 4
n a 8. 4 8. 3 1. 2 n a n a n a n a n a n a CG-1 G 10/05/9 4 S MI DR Y

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27 , 1995 FINA L * EE/CA Garibaldi Mine Site 4 2 2 TABL E 5 (cont'd ) SURFAC E WATE R ANALYSI S
- CALIFORNI A GULC H DOWNSTREA M O F GARIBALD I MIN E SIT E Locatio n Dat e Sourc e CI- T F - D F - T CN- T Acidit y Alkalinity- T (filt ) Alkalinity- T (unfilt ) Carbonate- D Carbonate- T Bicarbonate- D Bicarbonate- T S 0 4 (unfilt ) S O 4 (filt ) p H (lab ) p H (la b filt ) p H (la b unfilt ) Spec

. Cond

. (lab ) p H (field ) Spe c Con d (field ) T D S T S S Tem p (° ) CG-1 6

06/09/8 9 W W L

< 3 <0. 5 <0. 5 <0.00 5 6. 5 n a < 5

< 5 < 5 < 5 < 5 54 0 52 0 3. 1 n s n s 1000 2.5 6 1,13 6 60 0 < 5 4. 9 CG-1 5 06/09/8 9 W W L

<3 <0. 5 <0. 5
< 0.00 5 4.4
n a < 5

< 5 < 5 < 5 < 5 38 0 37 0 3. 6 n s n s 730 3.4 1 82 0 60 0 < 5 3. 7 CG-1 6 AN D CG-1 5 1 0/26/8 9 W W L CG-1 G 05/26/9 4 S M I
n a n a n a n a n a < 5 u < 5 u

n a n a n a n a 25 3 2 1 1
n s 3.1 7 j 3.16 J
n a 3.7 4 75 0 45 2 j
n a 3. 4 CG-1 G 10/05/9 4 S M I

Concentratio n i n mg/l ; discharg e i n cfs ; p H i n standar d units ; specifi c conductanc e i n //mhos/cm ; acidit y i n meq/l

. T = Tota l n a = no t analyze d j = dat a estimate d D = Dissolve d u = not detecte d n s = not specifie d CG-1 6 = Californi a Gulc h belo w Garibald i CG-1 5 an d CG-1 G = Californi a Gulc h a t Count y Roa d 2

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27 , 1995 FINAL * EE/CA Garibaldi Mine Site * 23 TABLE 6 GARIBALD I GROUNDWATE R ANALYSIS Locatio n Dat e Sourc e Alkalinit y (a s CaC03 ) Bicarbonat e (a s CaCOS ) Carbonat e (a s CaC0 3 ) Ca- D Ca- T C l Mg- D Mg- T p H (lab) K - D Na- D Na- T S 0 4 I D S T S S AI- D AI- T As- D As- T Cd- D Cd- T Cu- D Cu- T Fe- D Fe- T Pb- D Pb- T Mn- D Mn- T Ag- D 

### Ag- T Zn- D Zn- T p H (field ) Spec

. Cond

. (field ) Tem p° C (field ) GMW1 W

10/12/9 4 S M I 7 0 7 0 0 5 3 n a < 1 1 1 2 6 7. 0 j 2 1
n a 103 238 j
n a <0.0 5 1 1 1 <0.00 1 0.05 9 0.00 2 0.07 2 <0.0 1 0.37 <0.0 2 u j 13 6
< 0.00 1 1.8 2 0.0 5 j 20. 8
< 0.000 5 0.0 5 0.37 j 6.5 3 6.48 33 9 4. 2 GMW1 W 2/8/9 5 Resurrectio n 7 6

n a 5 2 51. 9 1 1 1 2 7. 3 3. 5 3. 5 9 9 23 2 93 2 0.0 5 23. 6 <0.00 1 0.01 6 0.000 5 0.021 0 <0.0 1 0.1 5 <0.0 3 5 2 <0.00 1 0.3 9 <0.0 1 7. 6 <0.000 2 0.01 8 0.1 3 2.2 9 6.7 2 33 3 1. 8 Concentratio n i n mg/l ; p H i n standar d units ; specifi c conductanc e i n /umhos/cm

. T = Total na = not analyze d D = Dissolve d u = no t detecte d j = dat a estimate d GMW1 W = Garibald i Groundwate r Montorin g Wel l

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27, 1995 FINAL * EE/CA Garibaldi Mine Site * 24 Surfac e water sample s wer e als o colleae d fro m 3 monitorin g station s locate d downgradien t o f t h e Garibald i Min e site : GM-1
, CG-16
, an d CG-1G

. Fo r purpose s o f compariso n wit h th e upgradien t monitorin g sites , concentratio n range s fo r thes e sample s ar e presente d below : Alkalinit y - < 5 mg/ 1 (a s CaCO3) ; Sulfat e (D )
- 21 1 t o 52 0 mg/1 ; ID S
- 45 2 t o 67 5 mg/1 ; pH (field )
- 2.5 6 t o 3.74 ; Arseni c (D )
- < 0.00 5 t o 0.08 4 mg/1 ; Cadmiu m (D )
- 0.011 9 t o 0.1 2 mg/ 1 Chromiu m (D )
- < 0.00 5 mg/1 ; Coppe r (D )
- 0.7 2 t o 1.1 7 mg/1 ; Iro n (D )
- 4. 6 t o 6 3 mg/1 ; Lea d (D )
- < 0.00 5 t o 0.02 9 mg/1 ; Manganes e (D )
- 6.1 5 t o 1 3 mg/1 ; Nicke l (D )
- 0.0 2 t o 0.0 5 mg/1 ; Seleniu m (D )
- < 0.00 5 mg/1 ; Silve r (D )
- < 0.000 5 t o < 0.00 5 mg/1 ; and , Zin c (D )
- 10. 8 t o 22 1 mg/1

. Compariso n o f thes e dat a indicat e tha t fro m upgradien t t o downgradien t o f th e Garibald i Min e site , ther e i s a significan t decreas e i n alkalinit y an d pH an d a significan t increas e i n concentrations o f sulfate
, TDS
, arsenic , cadmium , copper , iron , lead , manganese , an d zinc

. Th e observed change s i n wate r qualit y suggest that th e Garibald i Mine sit e i s a sourc e o f Aci d Roc k Drainag e (ARD ) an d heav y metal s t o Californi a Gulch

. Analysi s o f water qualit y sample s collecte d fro m th e Garibald i porta l suggest s that porta l outflo w contribute s t o th e AR D an d heav y metal s release d fro m th e min e site

. Th e range o f constituen t concentration s fo r th e porta l sample s i s provide d below : Alkalinit y - < 5 mg/ 1 (a s CaCO3) ; Sulfat e p )
- 5 2 t o 76 mg/1 ; TD S
- 8 8 t o 15 6 mg/1 ; pH'(field)-4.4 4 t o 5.39;

. Arseni c (D )
- < 0.00 1 t o 0.0 2 mg/1 ; Cadmiu m (D )
- 0.003 3 t o 0.02 4 mg/ 1 Chromiu m (D )
- < 0.00 5 mg/1 ; Coppe r (D )
- 0.01 8 t o 0.088 2 mg/1 ; Iro n (D )
- < 0.0 1 t o 0.0 8 mg/1 ; Lead (D )
- < 0.00 5 t o 0.00 9 mg/1 ; Manganes e (D )
- 0. 9 t o 2.0 6 mg/1 ; Nicke l (D)

- <0.0 1 mg/1 ; Seleniu m (D )
- < 0.00 5 mg/1 ; Silve r (D )
- < 0.00 5 t o 0.0 2 mg/1 ; and , Zin c (D ) -1. 2 t o 3.5 9 mg/1

. Compare d t o th e upgradien t water qualit y samples , th e porta l sample s generall y exhibit lowe r p H an d alkalinit y an d contai n highe r concentrations o f sulfate
, TD S an d heav y metals

. However
, fo r severa l parameter s (sulfate
, TDS
, pH
, arsenic, cadmium , copper , iron, lead , H:\664\EECA\GARIBALD.FN

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_________________________________ FINAL * EE/CA Garibaldi Mine Site » 2 5 manganese , an d zinc ) th e qualit y o f th e porta l sample s i s notabl y bette r tha n th e downgradien t wate r qualit y samples

. Thi s suggest s tha t othe r source s a t th e min e site , i n additio n t o th e portal , ar e contributin g t o th e poo r wate r qualit y observe d downgradien t o f Garibaldi

. T h e stream s wer e generall y dr y durin g th e fal l monitorin g events , whil e th e porta l an d to e see p continue d t o flow

. See p flo w rate s ranged fro m 0.00 2 - 0.00 4 cf s durin g fal l monitorin g t o 0.02 5 c f s durin g sprin g monitoring

. Potentia l flo w pathway s throug h th e wast e roc k coul d includ e surfac e infiltratio n (fro m run-o n o r direc t precipitatio n ont o th e pile)
, porta l flo w no t intercepte d b y th e Resurrection/ASARC O

ditch , and/o r shallo w alluvia l groundwate r upgradien t o f th e wast e roc k pile

. Th e to e see p coul d resul t fro m on e o r mor e o f thes e flo w components

. 

### 2.3. 4 Area s Affecte d T h e area s affecte d b y th e releas e o f contaminant s fro m th e wast e roc k pil e include s th e surfac e wate r in Uppe r Californi a Gulch
, Lowe r Californi a Gulch
, an d th e Arkansa s River

. I n addition , th e groundwate r associate d wit h Californi a Gulc h ma y be impacte d b y th e infiltratio n o f wate r contaminate d b y metal s leache d fro m th e wast e roc k pile

. Potentia l groundwate r contaminatio n however, i s no t addresse d withi n thi s EE/CA

. 2 . 4 RIS K ASSESSMEN

T 

### 2.4. 1 Scop e o f Ris k Evaluatio n A Draft Final Baseline Aquatic Ecological Risk Assessment (DFBAERA), California Gulch, Leadville, Colorado, (Ro y F

. Weston
, Inc

. [Weston]
, 1994 ) identifie s th e site-wid e impac t o f min e wast e contaminatio n o n th e terrestria l an d aquati c ecosystem s a t th e Californi a Gulc h site

. Th e DFBAER A provide s a conceptua l mode l o f site-wid e exposur e fo r aquati c receptors

. I t identifie s surfac e wate r and sediment s a s th e exposur e pathway s o f concer n a s thes e medi a are th e mos t direc t an d significan t mean s o f exposur e fo r ecologica l receptor s (pag e 1-12 , DFBAERA)

. Contaminant s ar e delivere d t o th e surfac e water an d sediment s b y erosion o f contaminate d solid s and b y direc t contac t (i.e.
, runof f ove r contaminate d surface s durin g hig h flo w cause d b y episodi c stor m event s or sprin g snowmelt , or b y direc t contac t o f contaminate d materia l i n streams ) tha t liberat e solubl e metal s int o th e water

. I n addition , water passin g throug h contaminate d materia l ma y caus e contaminan t loadin g t o groundwate r whic h eventuall y discharge s t o surfac e water unde r certai n hydrologi c conditions

. However
, dat a (primaril y that collecte d b y th e Colorad o Divisio n o f Wildlif e [CDOW ] a s discusse d i n Sectio n 2. 4 o f th e DFBAERA ) provide d i n th e DFBAER A indicates that storm event s an d sprin g snowmel t runof f
ar e th e hydrologi c condition s tha t caus e th e mos t significan t loadin g o f contaminant s t o surfac e water and ris k t o ecologica l receptors

. 

### 2.4. 2 Conceptua l Sit e Mode l T h e DFBAER A constructe d a conceptua l sit e mode l t o describ e th e exposur e pathway s applicabl e t o th e sit e (Weston
, 1994)

. Surfac e soil s wer e identifie d a s th e primar y source s o f contaminants

. Primar y releas e mechanism s ar e infiltratio n transporte d b y groundwate r flo w an d surfac e runof f transporte d b y surfac e water flow

. Subsequently
, groundwater , surfac e water an d sedimen t becom e secondar y sources
. Seep s fro m groundwate r becom e secondar y releas e
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__________________________________ FINAL * EE/CA Garibaldi Mine Site » 2 6 mechanism s t o surfac e water

. Bioti c uptak e o f surfac e water an d sedimen t als o become s a secondar y releas e mechanism

. Consequently
, fou r exposur e medi a exist : surfac e water, biota , sedimen t an d surfac e soil

. Eac h impac t receptor s throug h tw o exposur e routes : ingestio n an d direc t contact

. T h e receptor s in th e aquatic ecosyste m identifie d b y th e DFBAER A includ e alga e an d plankton , macrophytes , macroinvertebrates ,

amphibians , an d fis h (primaril y trou t species)

. Benthic macroinvertebrate s ar e importan t specie s o f pre y fo r trout

. Othe r specie s depen d o n th e aquati c ecosyste m includin g waterfow l and bird s whic h inhabi t riparia n areas , and mammals

. 

### 2.4. 3 Applicatio n t o Garibald i Min e Sit e Remova l Actio n 2.4.3. 1 Aquati c Ecosyste m Ris k T h e conceptua l mode l o f ris k t o th e aquati c ecosyste m provide d in th e DFBAER A identifie s th e primary exposur e pathway s fo r th e aquati c ecosyste m in Californi a Gulc h an d th e Arkansa s Rive r a s surfac e water runof f an d sediment s du e t o erosio n fro m contaminate d sources
. A secondar y exposur e pathwa y i s th e leachin g o f contaminate d sediment s an d transpor t o f th e leachat e throug h groun d water flow

. A s such , control o f thes e exposur e pathways i s the objectiv e o f this remova l action

. Contro l o f th e exposur e pathway s ca n b e achieve d b y removal , isolation , chemica l treatmen t o r surfac e stabilization

. Th e direc t contact o f runof f wit h contaminate d surface s wil l b e reduced , thereb y reducin g erosio n o f thes e surfaces

. Infiltratio n throug h contaminate d materia l wil l als o be reduced

. Th e effectivenes s o f a remova l actio n alternativ e t o contro l th e release s o f contaminant s vi a thes e pathway s i s use d t o evaluat e th e relativ e effectivenes s i n reducin g aquati c ecosyste m ris k betwee n th e variou s remova l actio n alternative s evaluate d i n thi s EE/CA

. 2.4.3.2 Terrestria l Ecosyste m Risk A t this time , th e potentia l ris k fro m uptak e o f metal s b y vegetatio n o r direc t contact wit h contaminate d surface s canno t b e assessed

. However
, i t can b e conclude d tha t ris k does resul t fro m reductio n i n vegetatio n an d habitat , an d th e alternative s i n thi s EE/C A addres s tha t risk

.

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_________________________________ FINAL * EE/CA Garibaldi Mine Site » 2 7 

### 3 . 0 IDENTIFICATIO N

O F REMOVA L ACTIO N OBJECTIVE S

3 . 1 STATUTOR Y

LIMIT S O N REMOVA L ACTION S T h e statutor y limit s o n remova l actions pursuan t t o sectio n 10 4 (c)(l ) o f CERCL A d o no t appl y t o this EE/C A since i t i s no t Fund-financed

. 3 . 2 REMOVA L ACTIO N SCOPE
, GOALS
, AN D OBJECTIVE S 

### 3.2. 1 Remova l Actio n Scop e T h e scop e o f this remova l actio n i s th e remediatio n o f th e Garibald i Min e sit e in Uppe r Californi a Gulch

. Thi s remova l actio n i s par t o f th e overal l remediatio n activitie s undertake n i n OU- 4 b y Resurrectio n Minin g Company i n complianc e wit h th e Consen t Decre e (USDC
, 1994)

. Thi s EE/C A evaluate s interi m respons e actions

. Th e Fina l Wor k Pla n fo r thi s EE/C A (TerraMatrix/SMI
, 1994 ) state s tha t th e propose d remova l action s ar e no t intende d t o b e fina l actions , bu t ar e intende d t o ensur e tha t th e sit e i s stabilize d unti l remedia l actio n begins

. Th e EE/C A nonetheles s complie s wit h th e Nationa l Contingency Pla n an d applicabl e EP A guidanc e becaus e th e EE/C A evaluate s remova l actio n alternative s tha t wil l contribut e t o th e efficien t performanc e o f th e long-ter m remedia l actions fo r th e site

. 

### 3.2. 2 Removal Actio n Goal s The primar y remova l actio n goa l o f thi s EE/C A i s t o reduc e th e ris k t o th e aquati c an d terrestria l ecosystem s b y reducin g th e releas e o f contaminate d materia l int o th e environment

. Thes e releases contribut e t o th e degradatio n o f water qualit y downstrea m o f th e sit e i n Uppe r Californi a Gulc h an d potentiall y th e Arkansa s River

. B y minimizin g run-o n to , runof f from
, an d infiltratio n throug h th e Garibald i Min e site , th e remova l actio n i s intende d t o reduc e th e overal l potentia l fo r leachin g heav y metal s fro m th e wast e roc k an d th e migratio n o f heav y meta l contaminatio n int o surfac e water

. 

### 3.2. 3 Remova l Actio n Objective s The primar y objectiv e o f the selecte d remova l action i s t o contro l release s o f contaminant s t o the environmen t i n a cost-effectiv e and timel y manner . Remedial actio n objective s describe d i n t h e SF S (EPA
, 1993a ) include : • Contro l win d and water erosion o f wast e roc k materia l fro m the sourc e location s • Contro l leachin g an d migratio n o f metal s fro m wast e roc k int o surfac e water • Contro l leachin g an d migratio n o f metal s fro m wast e roc k int o groundwate r T h e remova l actio n alternative s develope d fo r thi s EE/C A ar e intende d t o contro l th e releas e 

### mechanism s o f erosio n and leaching , and thereb y prevent the consequentia l degradatio n o f water qualit y i n downstrea m receivin g streams

. Al l alternative s ar e evaluate d base d upo n thei r effectiveness
, implementability ,

an d cost

.
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_________________________________ FINAL * EE/CA Garibaldi Mine Site » 28 Anothe r objectiv e i s th e implementatio n o f a non-tim e critica l remova l actio n tha t wil l be compatibl e wit h th e fina l remedia l actio n pla n tha t i s develope d fo r OU- 4 withi n th e Feasibilit y Stud y (FS ) process

. 3 . 3 REMOVA L ACTIO N SCHEDUL E 

### 3.3. 1 Remova l Schedul e Implementatio n o f th e ^referre d remova l actio n i s currentl y schedule d t o b e complete d i n 1995 , bu t i s dependen t o n a . prova l o f th e fina l EE/C A repor t an d remedia l design

. Th e detaile d schedul e fo r fiel d activitie s mus t b e reconcile d wit h th e shor t constructio n season i n Lake County

. Potentia l delay s i n th e preparatio n o f th e Actio n Memorandu m tha t wil l impac t expeditiou s schedulin g o f constructio n activitie s wil l be considere d a dela y b y forc e majeure

. Completio n o f th e administrativ e proces s fo r th e remova l actio n wil l preven t constructio n until
at leas t th e fourt h quarte r o f 1995

. 

### 3.3. 2 Planne d Activitie s A n EE/C A mus t b e complete d fo r al l non-time-critica l remova l action s a s require d b y CERCLA

. A publi c notic e describin g th e EE/C A an d announcin g a publi c commen t perio d
o f at leas t 3 0 day s wil l b e publishe d i n a majo r loca l newspaper

. The EE/C A i s par t o f the administrativ e record file an d i s subjec t t o th e publi c commen t an d commen t respons e requirement s fo r th e administrativ e record

. Th e publi c commen t perio d i s expecte d t o begi n i n earl y Jun e 199 5 an d en d i n earl y Jul y 1995

. A publi c metin g t o discus s the remova l actio n alternative s i s expecte d t o b e schedule d i n mi d Jun e 1995

. Afte r th e perio d fo r publi c comment , a n Actio n Memorandu m wil l b e prepare d b y th e EPA

. Th e Actio n Memorandu m provide s a concise , writte n recor d o f th e decisio n t o selec t a n appropriat e remova l action

. Th e Actio n Memorandu m als o comprises a summar y o f th e comment s fro m th e public

. Base d o n th e curren t schedule , i t i s anticipate d tha t th e Actio n Memorandu m wil l b e finalize d b y the EP A i n earl y Augus t 1995

. Followin g issuanc e o f th e Actio n Memorandum
, a detaile d engineerin g document , referre d t o a s the Remedia l Desig n (RD)
, i s prepare d t o presen t the desig n o f the selecte d remova l action

. I t i s anticipate d tha t th e Remedia l Desig n proces s wil l b e complete d i n Septembe r 1995

. A
secon d document , entitle d th e Remedia l Actio n (RA ) Wor k Plan
, i s the n prepare d t o describe th e plan s and schedules for implementatio n o f th e selecte d remova l action

. Base d on th e curren t schedule , i t i s anticipate d that the RA Wor k Pla n wil l als o b e complete d i n Septembe r 1995

. Subjec t t o EP A issuance o f th e Actio n Memorandum
, preparatio n an d EP A an d Stat e approva l
o f th e RD an d R A Wor k Plan
, an d contracto r selection , i t i s anticipate d that constructio n o f th e selecte d remova l actio n wil l b e initiate d i n Septembe r 1995

. Assumin g favorabl e weathe r conditions , i t i s anticipate d tha t constructio n coul d b e complete d i n Novembe r 1995

.

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__________________________________ FINAL * EE/CA Garibaldi Mine Site » 2 9 

### 4 . 0 IDENTIFICATIO N

AN D ANALYSI S O F 

### REMOVA L ACTIO N ALTERNATIVE S

4 . 1 ALTERNATIV

E IDENTIFICATIO N

AN D INITIA L SCREENIN G Thi s EE/C A discusse s efficient
, implementable , an d cost-effectiv e technologie s tha t appl y t o wast e roc k remova l actions

. Guidanc e fo r th e identificatio n o f appropriat e technologie s i s fro m th e Final Screening Feasibility Study fo r Remediation Alternatives a t th e California Gulch NP L Site, Leadville, Colorado, (SFS ) particularl y Sectio n 9 , Wast e Roc k (EPA
, 1993a ) an d fro m th e EPA

approved.Fz?M / Engineering Evaluation/Cost Analysis Work Plan fo r th e Garibaldi Mine Site(OU4 ) (TerraMatrix/SMI
, 1994)

. Guidanc e fo r th e preparatio n o f thi s EE/C A i s als o provide d i n th e Guidance o n Conducting Non-Time-Critical

Removal Actions Under th e Comprehensive Environmental Response, Compensation, an d Liability Ac t (EPA
, 1993b)

. T h e SF S retaine d th e following wast e roc k alternative s fo r detaile d analysi s i n th e Feasibilit y Study : • Alternativ e 1 : N o Actio n • Alternativ e 2 : Institutiona l

Contro l • Alternativ e 3 : Containmen t

(Surfac e Wate r Control)/Institutiona l

Contro l • Alternativ e 4 : Containmen t

(Surfac e Wate r Control
, Surfac e Barrier)/ Institutiona l Control s • Alternatives :

Containmen t

(Surfac e Wate r Control
, Sourc e Surfac e Control) / Institutiona l Control s • Alternativ e 6 : Containmen t

(Surfac e Wate r Control
, Sourc e Surfac e Control
, Surfac e Barrier)/Institutiona l

Control s • Alternativ e 7 : Removal/Transport/Disposal/Institutiona l Control s Site-specifi c application s o f thes e broadl y define d alternative s wer e considere d an d a limite d numbe r o f appropriat e remova l actio n alternative s addressin g wast e roc k wer e retaine d fo r analysi s withi n this EE/CA

. T h e N o Actio n alternativ e define d in th e SF S wa s no t retaine d fo r detaile d analysi s in th e EE/CA

. I n accordanc e wit h EP A guidanc e o n conductin g non-time-critica l remova l actions , th e purpos e o f the non-time-critica l remova l actio n proces s i s t o evaluat e a limite d number o f appropriat e remova l actio n alternative s an d t o implemen t a selecte d remova l actio n consisten t wit h th e establishe d goal s an d objectives

. Th e N o Actio n alternativ e does no t see k t o contro l sources , but leave s source s i n thei r existin g condition

. A s such , the N o Actio n alternativ e doe s no t satisf y th e objective s define d b y th e EE/CA
, an d i s inconsisten t wit h th e purpos e o f th e non-time-critica l remova l action

. T h e Institutiona l Control s alternativ e define d i n th e SF S wa s no t retaine d fo r detaile d analysi s i n the EE/C A a s a separat e alternative , bu t i s a componen t o f othe r alternatives

. Othe r technologie s identifie d i n th e SF S wer e retaine d fo r analysi s i n th e EE/CA

. Whil e th e EE/C A incorporates thes e technologie s i n alternatives , the structur e o f presentatio n ha s bee n modifie d fro m th e SF S t o reflec t th e site-specifi c natur e an d exten t o f Garibald i wast e rock

. Fo r instance , a surfac e barrie r a s define d unde r Alternative s 4 an d 6 i n th e SF S i s no t analyze d furthe r withi n this EE/CA
, since i t woul d no t b e effectiv e given th e natur e an d extent o f sit e contamination

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27, 1995 FINAL * EE/CA Garibaldi Mine Site * 30 A simpl e cover , however, ha s bee n include d i n Alternativ e C whic h act s a s bot h a source surfac e contro l an d a surfac e barrier

. Thi s structur e i s consisten t wit h th e alternative s identifie d in th e EPA-approve d EE/C A Wor k Plan

. T h e alternative s analyze d incorporat e site-specifi c application s o f th e SF S Alternatives

. I n addition , th e alternative s ar e consisten t wit h th e natur e an d exten t o f contaminatio n an d th e removal actio n objectives

. Th e removal actio n alternative s analyze d i n furthe r detai l withi n thi s EE/C A include : • Alternativ e A : Surfac e Wate r an d Porta l Flo w Diversio n — Thi s alternativ e entail s th e interceptio n an d diversio n o f strea m flo w (includin g porta l flow ) around th e wast e roc k b y reconstructio n o f existin g channel s and/o r constructio n o f
ne w channel s t o preven t run-o n t o and/o r infiltratio n through th e wast e rock

. Alternativ e A i s show n on Drawin g 2 and correspond s t o Alternativ e 3 a s presente d i n t h e SF S (EPA
, 1993a)

. • Alternativ e B : Surfac e Water
, Porta l Flow
, an d Shallo w Alluvia l Groundwate r Diversio n — Thi s alternativ e include s th e interceptio n an d diversio n o f strea m flo w (includin g porta l flow ) around th e wast e roc k b y reconstructio n o f existin g channel s and/o r constructio n o f ne w channel s t o preven t run-o n t o and/o r infiltratio n throug h th e wast e rock

. I t als o entail s th e diversio n o f shallo w alluvia l groundwate r flo w aroun d th e wast e roc k b y constructio n o f groundwate r intercepto r trenches

. Alternativ e B i s show n on Drawin g 3 an d als o correspond s t o Alternativ e 3 a s presente d i n th e S F S (EPA
, 1993a)

. • Alternativ e C : Surfac e Water
, Porta l Flow
, an d Shallo w Alluvia l Groundwate r Diversion/Regrading/Simpl

e Cove r — Thi s alternativ e include s th e interceptio n an d diversio n o f strea m flo w (includin g porta l flow ) around th e wast e roc k b y reconstructio n o f existin g channel s and/o r constructio n o f
ne w channel s t o preven t run-o n t o and/o r infiltratio n through th e wast e rock; diversio n o f shallo w alluvia l groundwate r flo w around th e wast e roc k b y constructio n o f groundwate r intercepto r trenches ; an d regradin g o f th e wast e roc k pil e an d constructio n o f a simpl e cove r t o minimiz e infiltratio n throug h th e wast e roc k pil e an d expedit e non-erosive runof f fro m th e pil e surface

. Th e simpl e cove r woul d b e designe d a s bot h a source surfac e contro l an d surfac e barrier

. Alternativ e C i s show n i n Drawin g 4 an d correspond s t o Alternativ e 5 a s presente d i n 

### t h e SF S (EPA
, 1993a)

.

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__________________________________ FINAL * EE/CA Garibaldi Mine Site » 31 • Alternativ e D : Wast e Roc k Remova l — Thi s alternativ e entail s th e remova l
o f th e wast e roc k fro m th e sit e an d transpor t t o th e Orego n Gulch Tailin g Impoundmen t fo r disposal

. I t also include s reestablishmen t o f th e origina l drainag e channel

. Alternativ e D
, show n o n Drawin g 5 , correspond s t o Alternativ e 7 as presente d i n th e SF S (EPA
, 1993a)

. Institutiona l control s (Alternativ e 2 i n th e SFS)
, includin g poste d warnings , informatio n an d educatio n programs , and/o r othe r control s woul d also b e incorporate d withi n the remova l actio n alternative s evaluated , a s approve d b y EPA

. Th e criteri a utilize d i n th e analysi s o f th e fou r remova l actio n alternative s ar e define d i n th e Guidance on Conducting Non-Time-Critical

Removal Actions Under the Comprehensive Environmental Response, Compensation, an d Liability Ac t (CERCLA) (EPA
, 1993b)
, an d includ e effectiveness
, implementability ,

an d cost

. Thes e EP A criteri a ar e utilize d a s screenin g criteria t o ai d i n th e selectio n o f th e appropriat e remova l actio n fo r th e Garibald i Min e site

. I n addition , th e Work Area. Management Plan (WAMP ) (USDC
, 1994 ) performanc e criteria o f erosio n stabilit y an d flo w capacit y an d stabilit y ar e utilize d i n evaluatin g th e effectivenes s o f th e remova l actio n alternative s i n meetin g th e remova l actio n objective s (RAOs)

. RAO s ar e furthe r discusse d i n Sectio n 3.2

. Afte r detaile d evaluatio n o f th e individua l remova l actio n alternatives , a comparativ e analysi s o f thes e alternative s i s presente d i n Sectio n 5. 0 identifie s th e advantages an d disadvantage s o f
eac h alternativ e relativ e t o on e anothe r considerin g th e EP A criteri a o f effectiveness
, implementability , and cost

. 4 . 2 EVALUATIO N

CRITERI A EP A guidanc e (EPA
, 1993a ) prescribe s th e evaluatio n o f remova l alternative s accordin g t o thre e mai n criteria : effectiveness
, implementabilit

y an d cost

. Thes e criteri a ar e define d i n th e Guidance on Conducting Non-Time-Critical

Removal Actions Under the Comprehensive Environmental Response, Compensation, an d Liability Ac t (CERCLA) (EPA
, 1993b ) an d ar e utilize d a s screenin g criteri a t o ai d i n th e selectio n o f th e appropriat e remova l actio n fo r th e Garibald i Min e site

. Thes e criteri a are describe d below

. Effectivenes s — Th e effectivenes s o f a n alternativ e refer s t o it s abilit y t o mee t th e objeaive s withi n th e scop e o f th e remova l action

. Thi s criterio n i s evaluate d for : ( 1 ) Overal l protectio n o f publi c healt h an d th e environment , comprisin g of : how eac h alternativ e achieve s adequat e protectio n ho w eac h alternativ e reduce s ris k identificatio n o f an y unacceptabl e short-ter m impacts ; ( 2 ) Complianc e wit h Applicabl e o r Relevan t an d Appropriat e Requirement s (ARARs )
an d other guidanc e criteria , comprisin g of : summar y o f potentia l ARAR s strateg y fo r complianc e wit h ARARs ;

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_________________________________ FINAL * EE/CA Garibaldi Mine Site * 32 ( 3 ) Long-ter m effectivenes s an d permanence , comprisin g of : assessmen t o f ris k fro m residua l wast e contributio n t o futur e remedia l objective s adequac y and reliabilit y o f controls ; ( 4 ) Reductio n o f toxicity , mobilit y o r volum e throug h treatment , comprisin g of : treatmen t proces s employe d an d natur e o f material s treate d
amoun t o f contaminate d material t o b e treate d degre e o f reductio n expecte d i n toxicity , mobilit y o r volum e degre e t o whic h treatmen t i s irreversibl e typ e an d quantit y o f treatmen t residual s whethe r th e alternativ e satisfie s CERCLA' s preferenc e fo r treatment ; an d ( 5 ) Short-ter m effectiveness
, comprisin g of : protectio n o f th e communit y protectio n o f th e worker s no advers e impact s t o the environment tim e t o achievement o f objective s Implementabilit y — Implementabilit y o f a n alternativ e addresse s it s technica l an d administrativ e feasibilit y an d th e availabilit y o f necessar y service s an d materials

. Th e evaluatio n i s base d on : ( 1 ) Technica l feasibility
, comprisin g of : abilit y o f th e technology t o implemen t th e remed y reliabilit y o f th e technolog y influenc e o f climati c condition s post-remova l sit e control s integratio n wit h fina l remediation ; ( 2 ) Administrativ e

feasibility
, comprisin g of : statutory limit s permit s and waivers; ( 3 ) Availabilit y o f service s an d materials , comprisin g of : personne l an d technology off-site treatment , storag e an d disposa l service s an d material s availabilit y o f full-scal e technology ; ( 4 ) State/EP A acceptance ; an d ( 5 ) Communit y acceptance

. Cos t — Thi s i s an order-of-magnitud

e evaluatio n o f proje a costs , whic h i s comprise d o f direc t capita l costs , indirec t capita l costs , an d post-remova l sit e control/operatio n an d maintenanc e costs

. A presen t wort h analysi s wil l b e carrie d out fo r the post-remova l sit e control/operatio n 

### an d maintenanc e cost s usin g a 7 % discoun t rat e (EPA
, 1987b)
, assumin g tha t th e fina l remediatio n wil l occu r within fou r years
.

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_________________________________ FINAL * EE/CA Garibaldi Mine Site » 33 Performanc e criteri a describe d in th e WAM P (USDC
, 1994 ) wil l als o b e utilize d t o evaluat e th e effectivenes s o f th e removal actio n alternative s i n aieetin g RAOs

. Diversio n ditche s (Alternative s A
, B
, an d C ) wer e designe d t o safel y conve y th e pea k discharg e fro m th e 100-year , 24-hou r storm

. Th e HEC- 1 hydrologi c mode l was utilize d t o simulat e surfac e runof f resultin g fro m th e desig n storm

. Result s ar e presente d in Appendi x B

. Surfac e wate r diversion s wer e size d usin g Manning' s Equatio n fo r ope n channel flow

. T h e Hydrologi c Evaluatio n o f Landfil l Performanc e (HELP ) mode l wa s utilize d t o predic t infiltratio n through th e wast e roc k pil e wit h an d withou t regradin g an d a simpl e cove r (Alternative s A
, B
, an d C)

. HEL P result s ar e include d in Appendi x C

. Th e SEDCAD + model , utilizin g th e Revised Universa l Soi l Los s Equatio n (RUSLE ) subroutine , was use d t o determin e th e sedimen t yiel d o f th e wast e roc k pil e wit h an d withou t regradin g an d a simpl e cove r (Alternative s A
, B
, an d C)

. Sedimen t loadin g calculation s ar e include d i n Appendi x D

. A stabilit y analysis , usin g XSTAB L software
, wa s als o performe d fo r th e wast e roc k pil e wit h an d withou t regradin g an d a simpl e cove r (Alternative s A
, B
, an d C)

. Th e XSTAB L analysi s i s include d i n Appendi x E

. 4 . 3 ALTERNATIV

E A
- SURFAC E WATE R AN D PORTA L FLO W DIVERSIO N 

### 4.3. 1 Descriptio n o f Alternativ e A Alternativ e A entail s th e diversip n o f surfac e wate r flo w (includin g porta l flow ) aroun d th e wast e roc k b y reconstructio n o f existin g channel s and the constructio n o f ne w channel s t o preven t run-o n t o the wast e rock

. 

### 4.3.1. 1 Diversio n Channels/Acces s Roa d Improvement s Unde r Alternativ e A
, fou r channel s woul d b e constructe d (approximatel y 1,96 0 feet)

. Diversio n Ditch 1 , locate d alon g th e souther n edg e o f th e wast e pil e woul d diver t runof f aroun d th e wast e roc k pil e an d int o Diversio n Ditch 2

. Diversio n Ditch 2 locate d alon g th e northeas t edg e o f th e wast e roc k pil e woul d diver t runof f fro m Diversio n Ditch 1 , an d th e easter n strea m channel
aroun d the wast e roc k pil e t o Diversio n Ditch 4

. Diversio n Ditch 2 woul d b e route d throug h
a 36-inc h culvert under th e existin g acces s road

. I n addition , drainag e fro m th e existin g collapse d porta l woul d b e route d throug h Diversio n Ditch 2

. Diversio n Ditch 3 , locate d alon g the existin g acces s roa d northeas t o f th e wast e roc k pile , woul d diver t runof f alon g th e northeas t en d
o f the pil e t o Diversio n Ditch 4

. Diversio n Ditc h 4, locate d alon g the existin g acces s roa d on th e nort h sid e o f th e wast e roc k pile , woul d collec t runof f fro m Diversio n Ditche s 2 an d 3 an d th e nort h strea m channel , an d rout e th e flo w aroun d th e pil e t o th e natural strea m bed

. Tw o 36-inc h culvert s woul d be installe d i n th e uppe r portio n o f Diversio n Ditc h 4 t o rout e th e runof f unde r th e existin g acces s road

. A 48-inc h culver t woul d b e place d a t th e en d o f Diversio n Ditc h 4 t o conve y th e runof f bac k unde r th e existin g acces s roa d an d dow n th e stee p slop e t o th e natural drainage

. A n energ y dissipate r woul d b e required a t th e en d o f th e 48-inc h culvert

. Th e diversio n ditche s wer e designe d t o safel y conve y th e pea k discharg e fro m th e 100-year , 24

- 

### hou r event

. Al l runof f calculation s wer e performe d utilizin g th e HEC- 1 Compute r Mode l develope d b y U.S

. Arm y Corp s o f Engineers

. HEC- 1 i s a hydrologi c an d hydrauli c calculatio n mode l adapte d fo r us e o n a P C system

. Th e HEC- 1 hydrologi c mode l calculate s pea k flo w an d runof f volum e vi a a numerical modelin g techniqu e based o n use r input s o f a desig n stor m event

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_________________________________ FINAL * EE/CA Garibaldi Mine Site » 34 T h e methodolog y an d assumption s use d in calculatin g runoff
, an d mode l output s ar e include d i n Appendi x B
, HEC- 1 Model

. Th e ditc h desig n schedul e i s presente d o n Drawin g 2

. A s show n o n Drawin g 2, al l diversio n ditche s woul d be trapezoida l ditche s wit h 2-foo t bottom s an d 2H:1 V sid e slopes

. Diversio n Ditche s 2 an d 4 woul d b e line d wit h concret e (o r a n alternativ e linin g system ) fo r erosiona l stability

. Ditche s whic h d o no t cros s and/o r ar e no t adjacen t t o th e pil e wil l no t b e line d wit h concrete

. Diversio n Ditc h 1 woul d b e grass-line d an d Diversio n Ditch 3 woul d b e line d wit h riprap

. Alternativ e ditc h linin g system s wil l b e furthe r evaluate d i n th e Remedia l Design

. Unde r this alternative , th e acces s roa d t o th e Garibald i Min e Sit e woul d require improvemen t fo r us e b y heav y equipmen t an d th e haulin g o f material s t o th e site

. Approximatel y 50 0 fee t o f the acces s roa d woul d b e improve d b y minor regradin g and blading

. Culvert s woul d b e replaced , a s show n o n Drawin g 2

. 

### 4.3.1. 2 Constructio n Bes t management practice s (BMPs ) woul d b e utilize d durin g al l constructio n activitie s at th e site

. Temporar y sedimen t contro l structures , includin g placemen t o f straw bales , sedimen t contro l fences
, o r smal l berm s wil l b e utilize d t o contro l sedimen t runof f fro m th e site

. I n addition , dus t control , (includin g us e o f a wate r truck ) woul d b e practice d durin g construction

. 

### 4.3.2 Analysi s o f Alternativ e A EP A guidanc e (EPA
, 1993b ) prescribes the evaluatio n o f remova l action alternative s accordin g t o thre e mai n criteria : effectiveness
, implementability ,

an d cost

. A n evaluatio n o f Alternativ e A utilizin g thes e criteria follows

. 

### 4.3.2. 1 Effectivenes s

o f Alternativ e A T h e effectivenes s o f a n alternativ e refer s t o it s abilit y t o mee t th e objective s withi n th e scop e o f th e remova l action

. Th e effectivenes s o f a n alternativ e i s evaluate d based upo n overal l protectio n o f publi c healt h an d th e environment , complianc e wit h ARARs
, long-ter m effectiveness
, reductio n o f toxicity , mobility , o r volume , an d short-ter m effectiveness

. 

### Overal l Protectio n o f Public Healt h an d th e Environment : Fou r component s o f flo w throug h th e wast e roc k hav e bee n identified
, includin g surfac e water run-on ; direc t precipitatio n ont o t h e pile ; shallo w alluvia l groundwater ; an d porta l flow

. Thi s alternativ e woul d diver t surfac e run-o n an d porta l flo w aroun d th e wast e roc k pil e an d minimiz e leachin g an d erosiona l releases fro m thes e flo w components

. Surfac e infiltratio n (fro m direct precipitatio n ont o th e pile ) an d shallo w alluvia l groundwate r could , howeve r continu e t o flo w through th e pil e an d contribut e t o th e leachin g an d migratio n o f metal s fro m th e wast e rock

. Infiltratio n throug h th e pil e (fro m direc t precipitatio n o n the pile ) wa s estimate d at 1. 4 inche s pe r year , utilizin g the HEL P mode l (Appendi x C)

. I n addition , erosio n associated wit h these flo w component s woul d continue

. Sedimen t yiel d wa s estimate d a t 6. 1 tons/acre/yea r utilizin g th e RUSL E equatio n (Appendi x D)

. The stabilit y evaluatio n indicate s that the wast e roc k ha s a Facto r o f Safet y o f 1. 0 o r greater , a s describe d i n Appendi x E

.

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27

. 1995

__________________________________ FINAL * EE/CA Garibaldi Mine Site » 3 5 Complianc e Wit h ARARs : Appendi x F present s a lis t o f potentia l ARAR s fo r th e remediatio n o f th e Californi a Gulc h site , a s revise d b y EPA

. Complianc e wit h ARAR s (includin g cultura l resource s ARARs
, th e Cl : n Ai r Act
, th e Colorad o Ai r Qualit y Contro l Act
, th e stormwate r progra m o f th e Nationa l Pollutan t Discharg e Eliminatio n System
, th e Colorad o Nois e Abatemen t Act
, an d th e Colorad o Mine d Lan d Reclamatio n Act ) wil l b e achieved fo r this removal actio n alternative , a s require d b y EPA

. Long-Ter m Effectiveness : Thi s alternative , designe d fo r th e 100-yea r floo d event , woul d b e effectiv e i n diverting , an d stabl e under , th e 100-yea r pea k flow

. A s discusse d previously , i t woul d be effectiv e i n divertin g surfac e run-o n an d porta l flo w around th e wast e rock

. Sinc e les s wate r woul d com e i n contac t wit h th e sourc e (wast e rock)
, overal l meta l loadin g t o Uppe r Californi a Gulc h throug h leachin g and/o r erosio n woul d b e reduced

. Reductio n o f Toxicity
, Mobility
, o r Volume : Unde r thi s alternative , th e overal l volum e o f wate r flowing through/ove r th e wast e roc k source materia l woul d be reduced , thu s reducin g erosio n an d th e leachin g an d migratio n o f metal s fro m th e wast e rock

. Short-Ter m Effectiveness : Potentia l short-ter m risk s t o th e communit y resultin g fro m th e implementatio n o f this remova l actio n includ e dus t emissions an d increase d roa d traffic

. Th e Garibald i Min e Site
, however i s locate d approximatel y 3 mile s fro m th e populate d area s o f Leadvill e an d i s i n a topographicall y isolate d area . I n addition , short-ter m ris k factor s woul d b e effectivel y mitigate d throug h th e implementatio n o f standar d constructio n practices

. Dus t abatement practice s woul d be followe d durin g constructio n activities

. Additiona l roa d traffi c woul d b e ligh t an d limite d t o th e immediat e vicinit y o f th e Garibald i Min e Site
, excep t durin g mobilization , demobilization , an d th e delivery o f constructio n materials

. Ris k t o worker s durin g implementatio n o f this remova l actio n ma y resul t fro m dus t inhalation , contac t wit h contaminate d materials , an d othe r industria l safet y hazards

. Dus t abatemen t measure s durin g constructio n woul d effectivel y manage dus t exposure

. Contac t wit h contaminate d material s throug h accidenta l exposur e i s unlikel y t o occu r t o a traine d remediatio n worker , becaus e appropriat e safet y measure s woul d minimiz e thi s an d othe r potentia l hazards

. Impac t t o th e environment durin g implementatio n o f this remova l actio n ma y resul t fro m accidenta l discharg e o f runof f wit h suspende d solid s fro m contaminate d material s disturbe d durin g constructio n activities

. Potentia l release s woul d be minimize d through th e us e o f BMPs
, discusse d previousl y i n Sectio n 4.3.1.2

. 

### 4.3.2. 2 Implementabilit

y o f Alternativ e A T h e implementabilit y o f a n alternativ e addresse s it s technica l an d administrativ e feasibilit y an d the availabilit y o f necessar y service s an d materials

. The evaluatio n i s based o n technica l feasibility
, administrativ e feasibility
, availabilit y o f service s an d materials , state/EP A acceptance , an d communit y acceptance

. Technica l Feasibility : Th e technologie s use d i n thi s alternativ e ar e commo n an d widel y accepted

. Th e time-fram e fo r implementatio n ca n occu r within th e shor t constructio n season o f th e Leadvill e area . Th e reliabilit y o f desig n an d implementatio n i s based o n establishe d practice

. Climati c condition s wil l no t interfer e wit h "h e operatio n o f thi s remova l actio n alternative

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27, 1995 FINAL * EE/CA Garibaldi Mine Site * 36 Administrativ e Feasibility : Complianc e wit h statutory limit s o n remova l actions wil l no t be necessar y sinc e thi s remova l actio n i s no t CERCL A fund-financed

. Constructio n permit s wil l
not b e necessary
. Certai n federa l permits , suc h a s a stormwate r permit , ma y b e required

. Therefore
, th e schedul e fo r thi s alternativ e coul d b e hindere d b y administrativ e requirements

. Availabilit y o f Service s an d Materials : Thi s alternativ e ca n be implemente d usin g commonl y availabl e earth-movin g equipment

. Material s an d personne l wil l als o be readil y available

. State
, EP A an d Communit y Acceptance : I t i s believe d tha t th e EP A an d Stat e o f Colorad o wil l fin d element s o f thi s alternativ e acceptable

. However
, thi s criterio n wil l b e furthe r addresse d i n th e Actio n Memorandum

. T h e EE/C A proces s require s publi c review , an d comment s fro m th e publi c wil l als o b e addresse d i n th e Actio n Memorandum

. Communit y acceptanc e o f thi s remova l actio n alternativ e i s expected

. 4.3.2. 3 

### Cost o f Alternativ e A The cos t evaluatio n i s a n order-of-magnitud

e evaluatio n o f projec t cost s an d i s comprise d o f direc t capita l costs , indirec t capita l costs , an d post-remova l sit e control/operatio n

an d maintenanc e costs

. Th e cos t estimat e fo r Alternativ e A i s summarize d i n Tabl e 7 , Alternativ e A Cos t Summary

. Tota l cost s ar e estimate d a t $175,615 , an d includ e $93,41 6 fo r direc t capita l costs , $57,91 8 fo r indirec t capita l cost s an d $24,28 1 fo r pos t remova l sit e contro l cost s (presen t worth)

. Furthe r cos t estimat e dat a ar e presente d i n Appendi x G

. TABL E 7 ALTERNATIV E A
- COS T SUMMAR Y Direc t Capita l Cost s Indirec t Capita l Cost s Post-Remova l Site Contro l Cost s (presen t worth ) TOTA L $93,41 6 $57,91 8 $24,28 1 $175,61 5
4 . 4 ALTERNATIV

E B
- SURFAC E WATER
, PORTA L FLOW
, AN D SHALLO W ALLUVIA L GROUNOWATE R

DIVERSIO N 

### 4.4. 1 Descriptio n o f Alternativ e B Alternativ e B entail s th e diversio n o f strea m flo w (includin g porta l flow ) aroun d th e wast e roc k b y th e reconstructio n o f existin g channel s an d th e constructio n o f new channel s t o prevent runo n t o and/o r infiltratio n through th e wast e rock

. I t als o involve s th e diversio n o f shallo w alluvia l groundwate r flo w aroun d th e wast e roc k b y constructio n o f groundwate r intercepto r trenches

.

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_________________________________ FINAL * EE/CA Garibaldi Mine Site » 3 7 

### 4.4.1. 1 Diversio n Channels/Acces s Road Improvement s Diversio n channel s an d acces s roa d improvement s constructe d unde r Alternativ e B woul d b e th e sam e a s describe d unde r Alternativ e A i n Sectio n 4.3.1.1 , wit h th e following exceptions : • Diversio n Ditc h 2 woul d als o conve y flo w fro m th e easter n groundwate r intercepto r trench , a s furthe r discusse d belo w unde r Sectio n 4.4.1.2

. • Diversio n Ditch 4 woul d als o conve y flo w fro m th e norther n groundwate r intercepto r trench , a s furthe r discusse d belo w unde r Sectio n 4.4.1.2

. Alternativ e B i s portraye d i n Drawin g 3

. 

### 4.4.1. 2 Groundwate r

Intercepto r Trenche s Unde r Alternativ e B
, tw o groundwate r intercepto r trenches woul d b e constructed , a s show n i n Drawin g 3

. Th e groundwate r intercepto r trenc h fo r th e easter n channel woul d diver t flo w int o Diversio n Ditc h 2 an d th e groundwate r intercepto r trenc h fo r th e norther n strea m channel woul d diver t flo w int o Diversio n Ditch 4

. Th e intercepto r trenches woul d be approximatel y 3 fee t wid e an d approximatel y 1 0 fee t deep , down t o bedrock

. Th e trenche s woul d consis t o f
a gravel drain back-line d wit h a hig h densit y polyethylen e (HDPE ) liner

. A filte r fabri c woul d b e installe d aroun d th e clea n grave l t o reduc e siltatio n an d clogging

. A perforate d polyviny l chlorid e (PVC ) pip e woul d b e place d i n th e botto m o f th e trench

. Th e perforate d PV C pip e woul d b e connecte d t o a soli d PV C pip e whic h woul d ti e int o th e diversio n channels , a s show n on Drawin g 3

. The intercepto r trenc h woul d b e keyed int o bedrock , a s condition s allow

. 

### 4.4.1. 3 Constructio n BMPs
, a s describe d unde r Alternativ e A i n Sectio n 4.3.1. 2 woul d b e utilize d durin g al l constructio n activitie s at the site

. 

### 4.4. 2 Analysi s o f Alternativ e B 

### 4.4.2. 1 Effectivenes s

o f Alternativ e B Overal l Protectio n o f Publi c Healt h an d th e Environmen t — A s discusse d unde r Alternativ e A
, fou r component s o f flo w throug h th e wast e roc k hav e bee n identified
, includin g surfac e wate r run-on ; direc t precipitatio n ont o th e pile ; shallo w alluvia l groundwater ; an d porta l flow

. Thi s alternativ e woul d minimiz e th e contact o f thre e o f thes e component s wit h th e wast e roc k
an d thereb y reduc e leachin g an d erosional release s fro m thes e flo w components

. Unde r Alternativ e B
, surfac e run-o n and porta l flo w woul d b e diverte d aroun d the wast e roc k pil e and th e shallo w alluvia l groundwate r woul d b e diverte d fro m th e pil e throug h th e groundwate r intercepto r trenc h t o th e diversio n channels

. Surfac e infiltratio n fro m direc t precipitatio n would , howeve r continu e t o flo w through th e pil e an d contribut e t o th e leachin g an d migratio n o f metal s fro m th e wast e rock

. Infiltratio n throug h th e pil e (fro m direc t precipitatio n o n th e pile ) wa s estimate d a t 1. 4 inche s pe r year , utilizin g th e HEL P mode l (Appendi x C)

. I n addition , erosio n associate d wit h thi s flo w componen t woul d continue

. Sedimen t yiel d wa s estimate d a t 6. 1 ton s pe r acr e pe r yea r utilizin g th e RUSL E equatio n (Appendi x D)

. Th e stabilit y evaluatio n

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__________________________________ FINAL * EE/CA Garibaldi Mine Site » 3 8 indicate s tha t th e wast e roc k pil e ha s a Facto r o f Safet y o f 1. 0 o r greater , a s describe d i n Appendi x E

. Complianc e "Wit h ARARs — Appendi x F present s a lis t o f potentia l ARAR s fo r th e remediatio n o f the Californi a Gulc h site , a s revise d b y EPA

. Complianc e wit h ARAR s (includin g cultura l resource s ARARs
, th e Clea n Ai r Act
, th e Colorad o Ai r Qualit y Contro l Act
, t h e stormwate r progra m o f th e Nationa l Pollutan t Discharg e Eliminatio n System
, th e Colorad o Nois e Abatemen t Ac t an d th e Colorad o Mine d Lan d Reclamatio n Act ) wil l b e achieve d fo r this remova l actio n alternative , a s required

. Long-Ter m Effectivenes s — Thi s alternative , designe d fo r th e 100-yea r floo d event , woul d b e effectiv e i n diverting , an d stabl e under , th e 100-yea r peak flow

. A s discusse d previously , i t woul d b e effectiv e in divertin g surfac e run-on , porta l flow
, an d shallo w alluvia l groundwate r aroun d th e wast e rock

. Whil e i t i s anticipate d tha t th e groundwate r intercepto r trenches wil l diver t a portio n o f th e alluvia l groundwate r aroun d th e pile , th e overal l effectivenes s o f totall y eliminatin g this sourc e o f contac t wit h th e pil e i s uncertain

. Sinc e les s wate r woul d com e i n contac t wit h th e sourc e (wast e rock)
, however , overal l metal s loadin g t o Uppe r Californi a Gulc h woul d b e reduced

. Reductio n o f Toxicity
, Mobility
, o r Volum e — Unde r thi s alternative , th e overal l volum e o f wate r flowin g throug h th e wast e roc k source materia l woul d be reduced , thu s reducin g th e leachin g an d migratio n o f metal s fro m th e wast e rock

. Short-Ter m Effectivenes s — Potentia l short-ter m risks t o th e communit y resultin g fro m th e implementatio n o f thi s remova l actio n includ e dus t emissions an d increase d roa d traffic

. Th e Garibald i Min e Site
, however i s locate d approximatel y 3 mile s fro m th e populate d area s o f Leadvill e an d i s i n a topographicall y isolate d area . I n addition , short-ter m ris k factor s woul d b e effectivel y mitigate d through th e implementatio n o f standar d constructio n practices

. Dus t abatemen t practice s woul d b e followe d durin g constructio n activities

. Additiona l roa d traffi c woul d b e ligh t an d limite d t o th e immediat e vicinit y o f th e Garibald i Min e Site
, excep t durin g mobilization , demobilization , an d th e deliver y o f constructio n materials

. Ris k t o worker s durin g implementatio n o f thi s remova l actio n ma y resul t fro m dus t inhalation , contac t vit h contaminate d materials , an d othe r industria l safet y hazards

. Dus t abatemen t measure s durin g constructio n woul d effectivel y manag e dust exposure

. Contac t wit h contaminate d material s through accidenta l exposur e i s unlikel y t o occu r t o a traine d remediatio n worker , becaus e appropriat e safet y measure s woul d minimiz e thi s an d othe r potentia l hazards

. Impac t t o th e environment durin g implementatio n o f thi s remova l actio n ma y resul t fro m accidenta l discharg e o f runof f wit h suspende d solid s fro m contaminate d material s disturbe d durin g constructio n activities

. Potentia l releases woul d b e minimize d throug h th e us e o f BMPs
, discusse d previousl y i n Sectio n 4.3.1.2

. 

### 4.4.2.2 Implementabilit

y o f Alternativ e B Technica l Feasibilit y — The technologie s use d i n thi s alternativ e ar e commo n an d widel y accepted

. Th e time-fram e fo r implementatio n ca n occu r withi n th e shor t constructio n seaso n o f th e Leadvill e area . Th e reliabilit y o f desig n an d implementatio n i s based o n establishe d

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. Climati c condition s wil l no t interfer e wit h th e operatio n o f thi s remova l actio n 

### alternative

. Administrativ e Feasibilit y — Complianc e wit h statutor y limit s o n remova l action s wil l no t be necessar y sinc e this remova l actio n i s no t CERCL A fund-financed

. Constructio n permit s wil l
not b e necessary
. Certai n federa l permits , suc h a s a stormwate r permit , ma y b e required

. 

### Therefore
, th e schedul e fo r this alternativ e coul d b e hindere d b y administrativ e requirements

. Availabilit y o f Service s an d Material s — Thi s alternativ e ca n b e implemente d usin g commonl y availabl e earth-movin g equipment

. Material s an d personne l wil l als o b e readil y available

. State
, EP A an d Communit y Acceptanc e — I t i s believe d tha t th e EP A an d State o f Colorad o wil l fin d element s o f this alternativ e acceptable

. However
, thi s criterio n wil l b e furthe r 

### addresse d i n th e Actio n Memorandum

. T h e EE/C A proces s require s publi c review , an d comment s fro m th e publi c wil l b e addresse d i n th e Actio n Memorandum

. Communit y acceptanc e o f thi s remova l actio n alternativ e i s expected

. 4.4.2. 3 

### Cos t o f Alternativ e B The cos t estimat e fo r Alternativ e B i s summarize d i n Tabl e 8, Alternativ e B Cos t Summary

. 

### Tota l cost s ar e estimate d a t $208,039 , an d includ e $113,43 1 fo r direc t capita l costs , $70,32 7 fo r indirec t capita l cost s an d $24,28 1 fo r pos t remova l sit e contro l cost s (presen t worth)

. Furthe r 

### cos t estimat e dat a ar e presente d i n Appendi x G

. TABL E 8 ALTERNATIV E B
- COS T SUMMAR Y Direc t Capita l Cost s Indirec t Capita l Cost s Post-Remova l Sit e Contro l Cost s (presen t worth ) TOTA L $113,43 1 $70,32 7 $24,28 1 $208,03 9
4 . 5 ALTERNATIV

E C
- SURFAC E WATER
, PORTA L FLOW
, AN D SHALLO W ALLUVIA L GROUNDWATE R

DIVERSION/REGRADING/SIMPL E

COVER 

### 4.5. 1 Descriptio n o f Alternativ e C Alternativ e C entail s th e diversio n o f stream flo w (includin g porta l flow ) aroun d th e wast e roc k b y th e reconstructio n o f existin g channel s and th e constructio n o f new channel s t o preven t run o n t o and/o r infiltratio n through th e wast e rock

. I t als o involves th e diversio n o f shallo w alluvia l groundwate r flo w aroun d th e wast e roc k b y constructio n o f groundwate r intercepto r 

### trenches

. Additionally
, th e pil e surfac e woul d be regrade d an d a lo w permeabilit y simpl e cove r woul d be constructe d t o promot e runof f an d minimiz e infiltratio n throug h th e piles

.

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__________________________________ FINAL * EE/CA Garibaldi Mine Site » 40 

### 4.5.1. 1 Diversio n Channels/Acces s Road Improvement s Diversio n channel s an d acces s roa d improvement s constructe d unde r Alternativ e C woul d b e the sam e a s describe d unde r Alternativ e B i n Sectio n 4.4.1.1

. Alternativ e C i s portraye d i n Drawin g 4

. 

### 4.5.1. 2 Groundwate r

Intercepto r Trenche s Th e groundwate r intercepto r trenche s constructe d unde r Alternativ e C woul d be th e sam e as describe d unde r Alternativ e B i n Sectio n 4.4.1.2

. 

### 4.5.1. 3 Regrading/Simple

Cove r T h e wast e roc k pil e woul d b e regrade d an d stabilize d t o eliminat e ponding , promot e drainage , an d creat e a surfac e configuratio n tha t i s erosionall y stable

. N o terrain wil l be regrade d steepe r tha n 3H:1 V a s show n o n Drawin g 4

. Th e Facto r o f Safet y o f th e regrade d pil e wa s determine d t o b e 2. 0 unde r pseudostati c condition s and greate r tha n 2. 0 unde r draine d conditions

. Regradin g woul d requir e approximatel y 3,10 0 c y o f materia l movement

. Stabilize d surface s woul d be covere d wit h lo w permeabilit y borrow soi l amende d wit h organi c matte r an d fertilizer

. Th e amendment woul d b e mixe d int o th e to p 1 2 inche s o f th e soi l b y discin g o r usin g othe r appropriat e methods

. Hydroseeding
, involvin g th e applicatio n o f a mixtur e o f seed , fertilizer
, an d a tackifie r ma y b e use d a t th e site

. Hydroseedin g woul d preven t excessiv e erosio n o f th e sit e befor e a productiv e vegetativ e cove r i s established

. 

### 4.5.1. 4 Constructio n BMPs
, a s describe d unde r Alternativ e A i n Sectio n 4.3.1. 2 woul d b e utilize d durin g al l constructio n activitie s at the site

. 

### 4.5. 2 Analysi s o f Alternativ e C 

### 4.5.2. 1 Effectivenes s

o f Alternativ e C Overal l Protectio n o f Publi c Healt h an d th e Environmen t — A s discusse d unde r Alternativ e A
, fou r component s o f flo w throug h th e wast e roc k hav e bee n identified
, includin g surfac e wate r run-on ; direc t precipitatio n ont o th e pile ; shallo w alluvia l groundwater ; an d porta l flow

. Thi s alternativ e woul d minimiz e th e contac t o f al l fou r o f thes e component s wit h th e wast e roc k
an d thereb y reduc e leachin g an d erosiona l release s fro m thes e flo w components

. Unde r Alternativ e C
, surfac e run-o n an d porta l flo w woul d b e diverte d aroun d th e wast e roc k pil e an d t h e shallo w alluvia l groundwate r woul d b e diverte d fro m th e pil e throug h th e groundwate r intercepto r trenc h t o th e diversio n channels

. Surfac e infiltratio n through th e pil e an d th e erosional releas e o f sedimen t woul d b e minimize d through th e constructio n o f th e simpl e cover . Surfac e infiltratio n throug h th e pil e (fro m direc t precipitatio n o n th e pile ) woul d b e reduce d t o approximatel y 0. 8 inche s pe r yea r (se e Appendi x C ) and sedimen t yiel d woul d b e reduced t o approximatel y 1 to n pe r acr e pe r yea r (se e Appendi x D)

. Unde r thi s alternative , th e Facto r o f Safet y fo r th e wast e roc k pil e i s estimate d a t 2. 0 usin g th e XSTAB L model , a s describe d i n Appendi x E

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_________________________________ FINAL * EE/CA Garibaldi Mine Site » 4 1 Complianc e Wit h ARARs — Appendi x F present s a lis t o f potentia l ARAR s fo r th e remediatio n o f th e Californi a Gulc h site , as revise d b y EPA

. Complianc e wit h ARAR s (includin g cultura l resource s ARARs
, th e Clea n Ai r Act
, th e Colorad o Ai r Qualit y Contro l Act
, t h e storm-wate r progra m o f th e Nationa l Pollutan t Discharg e Eliminatio n System
, th e Colorad o Nois e Abatemen t Ac t an d th e Colorad o Mine d Lan d Reclamatio n Act ) wil l b e achieve d fo r thi s remova l actio n alternative , a s required

. Long-Ter m Effectivenes s — Thi s alternative , designe d fo r th e 100-yea r floo d event , woul d b e effectiv e i n diverting , an d stabl e under , th e 100-yea r pea k flow

. A s discusse d previously , i t woul d be effectiv e i n divertin g surfac e run-on , porta l flow
, an d shallo w alluvia l groundwate r aroun d th e wast e roc k an d woul d minimiz e infiltratio n flo w through th e wast e rock

. Whil e i t i s anticipate d tha t th e groundwate r intercepto r trenche s wil l divert a portio n o f th e alluvia l groundwate r aroun d th e pile , th e overal l effectivenes s o f totall y eliminatin g thi s sourc e o f contact wit h th e pil e i s uncertain

. Sinc e les s water woul d com e i n contac t wit h th e sourc e (wast e rock)
, however, overal l metal s loadin g t o Uppe r Californi a Gulc h woul d b e reduced

. Reductio n o f Toxicity
, Mobility
, o r Volum e — Unde r thi s alternative , th e overal l volum e o f water flowin g through th e wast e roc k sourc e materia l woul d b e reduced , thu s reducin g th e leachin g an d migratio n o f metal s fro m th e wast e rock

. Short-Ter m Effectivenes s — Potentia l short-ter m risk s t o th e communit y resultin g fro m th e implementatio n o f this remova l actio n includ e dus t emission s an d increased roa d traffic

. Th e Garibald i Min e Site
, howeve r i s locate d approximatel y 3 mile s fro m th e populate d area s o f Leadvill e an d i s i n a topographicall y isolate d area . I n addition , short-ter m ris k factor s woul d b e effectivel y mitigate d throug h the implementatio n o f standar d constructio n practices

. Dus t abatemen t practice s woul d b e followe d durin g constructio n activities

. Additiona l roa d traffi c woul d be ligh t an d limite d t o th e immediat e vicinit y o f th e Garibald i Min e Site
, excep t durin g mobilization , demobilization , an d th e deliver y o f constructio n materials

. Ris k t o worker s durin g implementatio n o f thi s remova l actio n ma y resul t fro m dust inhalation , contac t wit h contaminate d materials , an d othe r industria l safet y hazards

. Dus t abatement measure s durin g constructio n woul d effectivel y manage dus t exposure

. Contac t wit h contaminate d material s throug h accidenta l exposur e i s unlikel y t o occu r t o a traine d remediatio n worker , because appropriat e safet y measure s woul d minimiz e thi s an d othe r potentia l hazards

. Impac t t o th e environmen t durin g implementatio n o f thi s remova l actio n ma y resul t fro m accidenta l discharg e o f runof f wit h suspende d solid s fro m contaminate d material s disturbe d durin g constructio n activities

. Potentia l release s woul d b e minimize d throug h the us e o f BMPs
, discusse d previousl y i n Sectio n 4.3.1.2

. 

### 4.5.2. 2 Implementabilit

y o f Alternativ e C Technica l Feasibilit y — The technologie s use d i n thi s alternativ e are commo n and widel y accepted

. Th e time-fram e fo r implementatio n ca n occu r within th e shor t constructio n seaso n o f the Leadvill e area . The reliabilit y o f desig n and implementatio n i s base d o n establishe d practice

. Constructio n o f a simpl e cover , however , woul d involv e th e locatio n an d transpor t 

### o f suitabl e cove r material

. Climati c condition s wil l no t interfer e wit h th e operatio n o f thi s remova l actio n alternative

.

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27, 1995 FINAL * EE/CA Garibaldi Mine Site * 42 Administrativ e Feasibilit y — Complianc e wit h statutor y limit s o n remova l actions wil l no t be necessar y since this remova l actio n i s no t CERCL A fund-financed

. Constructio n permit s wil l
not b e necessary
. Certai n federa l permits , suc h a s a stormwate r permit , ma y b e required

. Therefore
, th e schedul e fo r thi s alternativ e coul d b e hindere d b y administrativ e requirements

. Availabilit y o f Service s an d Material s — Thi s alternativ e ca n be implemente d usin g commonl y availabl e earth-movin g equipment

. Material s an d personne l wil l als o be readil y available

. State
, EP A an d Communit y Acceptanc e — I t i s believe d tha t th e EP A an d Stat e o f Colorad o wil l fin d element s o f thi s alternativ e acceptable

. However
, this criterio n wil l b e furthe r addresse d i n th e Actio n Memorandum

. T h e EE/C A proces s require s publi c review , an d comment s fro m th e publi c wil l b e addresse d i n th e Actio n Memorandum

. Communit y acceptanc e o f thi s remova l actio n alternativ e i s uncertain , since i t woul d involv e coverin g an are a tha t coul d hav e histori c valu e t o the community

. 4.5.2. 3 

### Cos t o f Alternativ e C T h e cos t estimat e fo r Alternativ e C i s summarize d i n Tabl e 9 , Alternativ e C Cos t Summary

. Tota l cost s ar e estimate d a t $324,23 3 an d includ e $174,18 8 fo r direc t capita l costs , $107,99 7 fo r indirec t capita l cost s an d $42,04 8 fo r pos t remova l sit e contro l cost s (presen t worth)

. Furthe r cos t estimat e dat a ar e presente d i n Appendi x G

. TABL E 9 ALTERNATIV E C
- COS T SUMMAR Y Direc t Capita l Cost s Indirec t Capita l Cost s Post-Remova l Sit e Contro l Cost s (presen t worth ) TOTA L $174,18 8 $107,99 7 $42,04 8 $324,23 3
4 . 6 ALTERNATIV

E D
- WAST E ROC K REMOVA L 

### 4.6. 1 Descriptio n o f Alternativ e D Alternativ e D entail s the remova l o f the wast e roc k materia l and transpor t t o the Orego n Gulc h Tailin g Impoundmen t fo r disposal/utilizatio n i n remediatio n measure s i n OU-10

. Wast e roc k woul d b e remove d dow n t o th e existin g channe l grade , loade d wit h a n excavator , an d transporte d vi a 1 0 cubi c yar d trucks

. Truck s woul d travel fro m the Garibald i sit e alon g the Garibald i acces s roa d t o Lake Count y Roa d 2

. Fro m Lak e Count y Roa d 2 , truck s woul d procee d t o th e acces s roa d t o th e Ya k Tunne l Treatmen t Plant

. A new hau l roa d woul d b e constructe d fro m th e plant , ove r th e ridg e t o th e northeas t o f th e plan t t o th e Orego n Gulc h Tailing Impoundment

. Constructio n o f the ne w hau l roa d woul d provid e a shorte r hau l route , thu s reducin g remova l costs

. I n addition , i t woul d eliminat e constructio n traffi c throug h town

. Unde r thi s alternative , approximatel y 50 0 fee t o f the Garibald i acces s roa d woul d b e repaire d
and approximatel y 1,600 fee t o f ne w roa d woul d b e constructed

. Thi s alternativ e woul d require
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__________________________________ FINAL * EE/CA Garibaldi Mine Site » 4 3 tha t additiona l cultura l resourc e inventor y an d evaluatio n be conducte d fo r roa d improvement s and ne w roa d construction

. The propose d hau l rout e i s delineate d on Figur e 2

. Alternativ e D i s show n o n Drawin g 5

. BMPs
, a s describe d unde r Alternativ e A i n Sectio n 4.3.1. 2 woul d b e utilize d durin g al l constructio n activitie s at the site

. 

### 4.6. 2 Analysi s o f Alternativ e D 

### 4.6.2. 1 Effectivenes s

o f Alternativ e D 

### Overal l Protectio n o f Publi c Healt h an d th e Environment: A s discusse d unde r Alternativ e A
, fou r component s o f flo w throug h th e wast e roc k hav e bee n identified
, includin g surfac e wate r run-on ; direc t precipitatio n ont o th e pile ; shallo w alluvia l groundwater ; an d porta l flow

. Thi s alternativ e woul d eliminat e th e contact o f al l fou r o f thes e component s wit h th e wast e roc k
an d thereb y eliminat e leachin g an d erosiona l releases fro m thes e flo w components

. Unde r Alternativ e D
, th e wast e roc k woul d b e remove d fro m th e sit e an d wate r contac t wit h this sourc e woul d be eliminated

. Th e wast e roc k woul d be dispose d i n th e Oregon Gulc h Tailin g Impoundmen t an d woul d b e remediate d alon g wit h th e overal l OU-1 0 remediatio n plan s t o b e determine d unde r th e OU-1 0 Feasibilit y Study

. Unde r thi s alternative , flo w fro m th e Garibald i porta l woul d continu e t o flo w throug h Uppe r Californi a Gulch

. Complianc e Wit h ARAR s — Appendi x F present s a lis t o f potentia l ARAR s fo r th e remediatio n o f th e Californi a Gulc h site , as revised b y EPA

. Complianc e wit h ARAR s (includin g cultura l resource s ARARs
, th e Clea n Ai r Act
, th e Colorad o Ai r Qualit y Contro l Act
, th e stormwate r progra m o f th e Nationa l Pollutan t Discharg e Eliminatio n System
, th e Colorad o Nois e Abatemen t Ac t an d th e Colorad o Mine d Lan d Reclamatio n Act ) wil l b e achieve d fo r thi s remova l actio n alternative , a s required

. Long-Ter m Effectiveness : Unde r Alternativ e B
, th e sourc e materia l woul d b e relocate d permanentl y an d erosiona l an d leachin g releases fro m th e Garibald i sit e woul d be eliminated

. The wast e rock , however , woul d b e relocate d t o OU-1 0 and requir e remediatio n unde r the OU

1 0 Feasibilit y Stud y activities

. I n addition , flo w fro m th e Garibald i porta l woul d continu e t o flo w through Uppe r Californi a Gulch

. Reductio n o f Toxicity
, Mobility
, o r Volume : Unde r thi s alternative , th e wast e roc k sourc e materia l woul d be relocated , thus eliminatin g th e leachin g an d migratio n o f metal s fro m th e wast e roc k a t th e Garibald i site

. Th e wast e roc k would , howeve r contribut e t o th e metal s loadin g at it s ne w locatio n i n OU-iC
, unti l tha t sit e undergoe s remediation

. I n addition , flo w fro m th e Garibald i porta l woul d continu e t o flo w through Uppe r Californi a Gulch

. Short-Ter m Effectiveness : Potentia l short-ter m risk s t o th e communit y resultin g fro m th e implementatio n o f this remova l actio n includ e dus t emission s an d increase d roa d traffic

. Th e Garibald i Min e Site
, howeve r i s locate d approximatel y 3 mile s fro m th e populate d area s o f Leadvill e an d i s i n a topographicall y isolate d area . I n addition , short-ter m ris k factor s woul d be effectivel y mitigate d through th e implementatio n o f standar d constructio n practices

. Dus t abatemen t practice s woul d b e followe d durin g constructio n activities

. Additiona l roa d traffi c woul d resul t fro m th e implementatio n o f thi s alternative , betwee n the * Garibald i sit e an d th e Oregon Gulc h Tailing Impoundment

. Fo r a perio d o f approximatel y 1 month , 13 0 roun d trip s o f truc k haulin g woul d occu r per day , assumin g use o f a 1 0 cubi c yar d dum p truck

.

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__________________________________ FINAL * EE/CA Garibaldi Mine Site + 4 4 Ris k t o worker s durin g implementatio n o f thi s remova l actio n ma y resul t fro m dus t inhalation , contac t wit h contaminate d materials , an d othe r industria l safet y hazards

. Dus t abatemen t measure s durin g constructio n woul d effectivel y manage dus t exposure

. Contac t wit h contaminate d material s throug h accidenta l exposur e i s unlikel y t o occu r t o a traine d remediatio n worker , becaus e appropriat e safet y measure s woul d minimiz e this an d othe r potentia l hazards

. Impac t t o th e environment durin g implementatio n o f this remova l action ma y resul t fro m accidental discharg e o f runof f wit h suspende d solid s fro m contaminate d material s disturbe d durin g constructio n activities

. Potentia l releases woul d be minimize d through th e us e o f BMPs
, discusse d previousl y i n Sectio n 4.3.1.2

. 

### 4.6.2. 2 Implementabilit

y o f Alternativ e D Technica l Feasibility : Th e technologie s use d i n thi s alternativ e ar e commo n an d widel y accepted

. Th e time-fram e fo r implementatio n ca n occu r withi n th e shor t constructio n seaso n o f th e Leadvill e area . Th e reliabilit y o f desig n an d implementatio n i s based o n establishe d practice

. Climati c condition s wil l no t interfer e wit h th e operatio n o f thi s remova l actio n alternative

. Administrativ e Feasibility : Complianc e wit h statutory limit s o n remova l action s wil l no t be necessar y since thi s remova l actio n i s no t CERCL A fund-financed

. Constructio n permit s wil l no t b e necessary
. Certai n federa l permits , suc h a s a stormwate r permit , ma y b e required

. Therefore
, th e schedul e fo r thi s alternativ e coul d b e hindere d b y administrativ e requirements

. Severa l administrativ e issue s associate d wit h Alternativ e D must , however , b e resolve d prio r t o implementation

. Thes e includ e cultura l resource inventor y wor k an d complianc e wit h Sectio n 10 6 o f th e Nationa l Histori c Preservatio n Act ; access/ownershi p issue s associate d wit h th e hau l
roa d construction ; potentia l regulator y ramification s associate d wit h depositin g wast e roc k materia l i n Oregon Gulch ; and concern s ove r utilizin g Oregon Gulc h a s a deposi t are a fo r wast e roc k material

. Availabilit y o f Services an d Materials : Thi s alternativ e ca n be implemente d usin g commonl y availabl e earth-movin g equipment

. Material s an d personne l wil l als o be readil y available

. State
, EP A an d Communit y Acceptance : I t i s believe d tha t th e EP A an d Stat e o f Colorad o wil l fin d this alternativ e acceptable

. Bot h th e Stat e an d EP A hav e expresse d interes t i n th e pas t i n th e Remova l Alternative

. Thi s criterion , however , wil l be furthe r addresse d i n th e Actio n Memorandum

. T h e EE/C A proces s require s publi c review , an d comment s fro m th e publi c wil l b e addresse d i n th e Actio n Memorandum

. Communit y acceptanc e o f thi s remova l actio n alternativ e i s uncertain , sinc e i t woul d involv e removin g materia l fro m an are a tha t coul d hav e histori c valu e t o th e community

. 

### 4.6.2. 3 Cost o f Alternativ e D The cos t estimat e fo r Alternativ e D i s summarized i n Tabl e 10, Alternativ e D Cos t Summary

. Tota l cost s are estimate d a t $531,191 , and includ e $301,94 0 for direct capita l costs, $187,20 3 for 

### indirec t capita l cost s an d $42,04 8 fo r pos t remova l sit e contro l cost s (presen t worth)

. Furthe r cos t estimat e dat a are presente d i n Appendi x D

.

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27, 1995 FINAL * EE/CA Garibaldi Mine Site » 45 TABL E 1 0 ALTERNATIV E D
- COS T SUMMAR Y Direc t Capita l Cost s Indirec t Capita l Cost s Post-Remova l Sit e Contro l Cost s (presen t worth ) TOTAL $301,94 0 $187,20 3 $42,04 8 $531,19 1

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### 5 . 0 COMPARATIV

E ANALYSI S O F REMOVA L ACTIO N ALTERNATIVE S Thi s sectio n provide s a compariso n o f remova l alternatives base d on criteri a containe d i n the Guidance o n Conducting Non-Time-Critical

Removal Actions Under CERCLA (EPA
, 1993b ) an d discusse d i n Sectio n 4. 2 o f thi s EE/C A Report

. I n thi s evaluation , th e relativ e advantage s an d disadvantage s o f th e alternative s are directl y compare d i n a matri x evaluation

. Criteria use d i n thi s comparativ e analysi s includ e th e sam e thre e majo r categorie s (effectiveness
, implementability , and cost ) use d t o individuall y asses s eac h alternativ e i n Sectio n 4.0

. T h e comparativ e analysi s o f th e fou r alternative s considere d withi n thi s EE/C A i s presente d in Tabl e 11, Compariso n o f Alternatives

. Alternative s ar e rated poor , fair
, good , or ver y goo d relativ e t o th e evaluatio n criteria an d eac h other

. Pleas e refe r t o Sectio n 4. 0 fo r a mor e complet e discussio n o f th e evaluatio n o f th e individua l alternative s utilizin g th e effectiveness
, implementability , an d cos t criteria

. TABL

E 1 1 COMPARISO N O F ALTERNATIVE S Alternativ e A Alternativ e B Alternativ e C Alternativ e D Effectivenes s Overal l Protectio n o f Huma n Healt h an d Environmen t Complianc e wit h ARAR s Long-Ter m Effectivenes s Reductio n o f Toxicity
, Mobility
, Volum e Short-Ter m Effectivenes s F

G F F G G G G G G G G G G G V G G V G V G F Implementabilit y Technica l Feasibilit y Administrativ e Feasibilit y Availabilit y o f Service s an d Material s Anticipate d State/EP A Acceptanc e Anticipate d Communit y Acceptanc e G

G G G G G G G G G F G G G F G

F G V G F Cos t Tota l Direct Capita l Cost s Indirec t Capita l Cost s Post-Remove d Sit e Control/Othe r Gran d Tota l $93,41 6

$57,91 8 $24,28 1 $175,61 5 $113,43 1

$70,32 7 $24,28 1 $208,03 9 $174,18 8 $107,99 7 $42,04 8 $324,23 3 $301,94 0 $187,20 3 $42,04 8 $531,19 1 NOTES : F = Fai r G = Goo d V G = Ver y Goo d Tabl e 1 2 present s a mor e detaile d discussio n o f th e relativ e effectivenes s o f eac h alternative

.
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L 07/27/9 5 4:01p m \?P51/cm cTABL E 1 2 SUMMAR Y O F GARIBALD I WAST E ROC K EE/C A ALTERNATIVE S

- Alternativ e Alternativ e A
— Surfac e Wate r a n d Porta l Flo w Diversio n

Alternativ e B
— Surfac e Water
, Porta l Flow
, an d Shallo w Alluvia l Groundwate r Diversio n

Alternativ e C
- Surfac e Water
, Porta l Flow
, an d Shallo w Alluvia l Groundwate r Diversion / Regrading/Simpl e Cove r

Alternativ e D
— Wast e Roc k Remova l Effectivenes s

Reduce s 2 o f 4 potentia l flo w component s throug h th e wast e roc k (surfac e run-o n an d porta l flow ) Reduce s leachin g an d erosiona l release s associate d wit h surfac e run-on an d porta l flo w Surfac e erosio n o f wast e roc k pil e fro m direc t precipitatio n o n th e pile woul d continu e (approximatel y 6. 1 tons/acre/year ) Infiltratio n (1. 4 inches/year ) throug h th e wast e roc k pile fro m direc t precipitatio n o n th e pile woul d continu e Improve s erosiona l stabilit y o f th e diversio n channel s Surfac e stabilit y facto r o f safet y greate r tha n 1 Reduce s 3 o f 4 potentia l flo w component s throug h th e wast e roc k (surfac e run-on , porta l flow
, an d groundwater ) Reduce s leachin g an d erosiona l release s associate d wit h surfac e run-on , porta l flow
, an d groundwate r Surfac e erosio n o f wast e roc k pil e fro m direc t precipitatio n o n th e pil e woul d continu e (approximatel y 6. 1 tons/acre/year ) Infiltratio n (1. 4 inches/year ) throug h th e wast e roc k pil e fro m direc t precipitatio n o n th e pil e woul d continu e Improve s erosiona l stabilit y o f th e diversio n channel s Surfac e stabilit y facto r o f safet y greate r tha n 1 Reduce s 4 o f 4 potentia l flo w component s throug h th e wast e roc k (surfac e run-on , porta l flow
, groundwater , an d direc t precipitatio n o n th e pile ) Reduce s leachin g an d erosiona l release s associate d wit h surfac e run-on , porta l flow
, groundwater , an d direc t precipitatio n o n th e pile Reduce s surfac e erosio n o f wast e roc k pil e t o approximatel y 1

. 0 ton/acre/yea r Infiltratio n throug h th e wast e roc k pil e fro m direc t precipitatio n o n th e pile woul d b e decrease d t o approximatel y 0. 8 inches/yea r Improve s erosiona l stabilit y o f th e diversio n channel s Improve s surfac e stabilit y o f wast e roc k pil e t o facto r o f safet y o f 2. 0 unde r pseudostati c condition s an d greate r tha n 2. 0 unde r draine d condition s Eliminate s 4 o f 4 potentia l flo w component s throug h th e wast e roc k (surfac e run-on , porta l flow
, groundwater , an d direc t precipitatio n o n th e pile ) b y removin g th e wast e roc k Eliminate s leachin g an d erosiona l release s associate d wit h surfac e run-on , porta l flow
, groundwater , an d direc t precipitatio n o n th e pile Eliminate s surfac e erosio n o f wast e roc k pil e Eliminate s infiltratio n throug h th e wast e roc k pil e fro m direc t precipitatio n o n th e pil e Flo w fro m Garibald i porta l woul d continu e t o flo w i n Uppe r Californi a Gulc h Relocate d wast e roc k woul d requir e remediatio n unde r OU-1 0 F S activitie s Tota l

Estimate d Cos t $175,61 5

$208,039

$324,23 3

$531,19 1July

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_________________________________ FINAL * EE/CA Garibaldi Mine Site » 48 

### 6 . 0 RECOMMENDE D

REMOVA L ACTIO N ALTERNATIV

E Base d on th e individua l analysi s o f alternative s presente d i n Sectio n 4. 0 and th e comparativ e analysi s presente d i n Sectio n 5.0 , Alternativ e B i s recommende d fo r implementation

. A descriptio n o f Alternativ e B an d th e rational e fo r it s selectio n ar e provide d below

. 6 . 1 DESCRIPTIO

N O F ALTERNATIV E B Alternativ e B entail s th e diversio n o f strea m flo w (includin g porta l flow ) aroun d th e wast e roc k b y the reconstructio n o f existin g channel s and the constructio n o f ne w channel s t o preven t run on t o and/o r infiltratio n throug h the wast e rock

. I t als o involve s the diversio n o f shallo w alluvia l groundwate r flo w aroun d th e wast e roc k b y constructio n o f groundwate r intercepto r trenches

. Alternativ e B i s portraye d i n Drawin g 3

. Unde r Alternativ e B
, fou r channel s woul d be constructe d (approximatel y 1,96 0 feet)

. Diversio n Ditc h 1 , locate d alon g th e souther n edg e o f th e wast e pil e woul d diver t runof f aroun d th e wast e roc k pil e an d int o Diversio n Ditch 2

. Diversio n Ditc h 2 locate d alon g the northeas t edg e o f the wast e roc k pil e woul d diver t runof f fro m Diversio n Ditch 1 , an d th e easter n strea m channel
aroun d the wast e roc k pil e t o Diversio n Ditch 4

. Diversio n Ditch 2 woul d b e route d through
a 36-inc h culvert unde r th e existin g acces s road

. I n addition , drainag e fro m th e existin g collapse d porta l an d fro m th e easter n groundwate r intercepto r trenc h (discusse d furthe r below ) woul d be route d throug h Diversio n Ditch 2

. Diversio n Ditc h 3 , locate d alon g the existin g acces s roa d northeas t o f th e wast e roc k pile , woul d diver t runof f alon g th e northeas t en d o f th e pil e t o Diversio n Ditc h 4

. Diversio n Ditc h 4 , locate d alon g th e existin g acces s roa d o n th e nort h sid e o f th e wast e roc k pile , woul d collec t runof f fro m Diversio n Ditche s 2 an d 3 an d th e nort h strea m channel , an d rout e th e flo w aroun d th e pil e t o th e natura l strea m bed

. Diversio n ditc h 4 woul d als o conve y flo w fro m th e norther n groundwate r intercepto r trenc h (discusse d furthe r below)

. Tw o 36-inc h culvert s woul d b e installe d i n th e uppe r portio n o f Diversio n Ditch 4 t o rout e the runof f unde r the existin g acces s road

. A 48-inc h culver t woul d b e place d at the end
o f Diversio n Ditch 4 t o conve y the runof f bac k unde r the existin g acces s roa d and dow n the stee p slop e t o the natural drainage

. A n energ y dissipate r woul d b e .require d at the end o f the 48-inc h culvert

. Th e diversio n ditche s woul d be designe d t o safel y conve y th e pea k discharg e fro m th e 100-year , 24-hou r event

. The methodolog y an d assumption s use d i n calculatin g runof f an d model output s are include d i n Appendi x B
, HEC- 1 Model

. Th e ditc h desig n schedul e i s presente d on Drawin g 3

. A s show n o n Drawin g 3 , al l diversio n ditche s woul d b e trapezoida l ditche s wit h 2-foo t bottom s an d 2H:1 V sid e slopes

. T o hel p reduce infiltration
, Diversio n Ditche s 2 an d 4 woul d b e line d wit h concrete

. Ditche s whic h d o not cros s and/o r are not adjacen t t o the pil e wil l not b e line d wit h concrete

. Diversio n Ditch 1 woul d b e grass-line d an d Diversio n Ditc h 3 woul d b e line d wit h riprap

. 

### Unde r thi s alternative , th e acces s roa d t o th e Garibald i Min e Sit e woul d require improvemen t fo r us e b y heav y equipmen t and the haulin g o f material s t o the site

. Approximatel y 50 0 fee t o f th e acces s roa d woul d b e improve d b y minor regradin g an d blading

. Culvert s woul d b e replaced , a s show n o n Drawin g 3

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_________________________________ FINAL * EE/CA Garibaldi Mine Site » 49 Unde r Alternativ e B
, tw o ground-wate r intercepto r trenches woul d b e constructed , a s show n i n Drawin g 3

. Th e groundwate r intercepto r trenc h fo r th e easter n channe l woul d diver t flo w int o Diversio n Ditch 2 an d th e groundwate r intercepto r trenc h fo r th e norther n strea m channe l woul d diver t flo w int o Diversio n Ditch 4

. Th e intercepto r trenche s woul d be approximatel y 3 fee t wid e an d approximatel y 1 0 fee t deep , dow n t o bedrock

. The trenche s woul d consis t o f
a gravel drain back-line d wit h a high densit y polyethylen e (HDPE ) liner

. A filte r fabri c woul d be installe d aroun d th e clea n gravel t o reduc e siltato n an d clogging

. A perforate d polyviny l chlorid e (PVC ) pip e woul d b e place d in th e botto m o f th e trench

. Th e perforate d PV C pip e woul d b e connecte d t o a soli d PV C pip e whic h woul d ti e int o th e diversio n channels , a s show n on Drawin g 3

. The intercepto r trenc h woul d b e keyed int o bedrock , a s condition s allow

. Bes t managemen t practice s (BMPs ) woul d b e utilize d durin g al l constructio n activitie s at th e site

. Temporar y sedimen t contro l structures , includin g placemen t o f straw bales , sedimen t contro l fences
, o r smal l berm s woul d be utilize d t o contro l sedimen t runof f fro m th e site

. I n addition , dus t control , (includin g us e o f a water truck ) woul d b e practice d durin g construction

. 6 . 2 RATIONAL

E FO R SELECTION O F ALTERNATIV

E B 

### 6.2. 1 Effectivenes s Alternativ e B received a "good" ratin g i n term s o f overal l protectio n o f huma n healt h and environment , complianc e wit h ARARs
, long-ter m effectiveness
, short-ter m effectiveness
, an d reductio n o f toxicity , mobility , an d volume

. Alternativ e B minimize s th e contact o f th e thre e identifie d water component s a t th e Garibald i Min e Sit e (surfac e water run-on , porta l flow
, an d shallo w alluvia l groundwater ) wit h th e wast e roc k sourc e material

. Alternativ e B i s considere d effectiv e fo r th e following reasons : • Reduces 3 o f 4 potentia l flo w component s throug h th e wast e roc k (surfac e run-on , porta l flo w an d shallo w alluvia l groundwater )

• Reduce s leachin g associate d wit h surfac e run-on , porta l flo w an d shallo w alluvia l groundwate r • Reduce s erosional release s associate d wit h surfac e run-o n • Improve s erosional stabilit y o f th e diversio n channel s Run-o n i s considere d a fairl y majo r flo w componen t at the Garibald i sit e since the drainag e are a abov e Garibald i i s relativel y larg e (21 1 acres)

. Sinc e infiltratio n fro m direc t precipitatio n o n th e pil e woul d no t b e reduced b y thi s alternative , i t i s considere d slightl y les s effectiv e than Alternativ e C

. Th e reduce d cost s o f thi s alternative , however , justif y th e minima l differenc e i n effectivenes s o f th e tw o alternatives

. Whil e Alternativ e D i s considere d t o b e th e mos t effectiv e o f the alternative s analyzed , extremel y hig h cost s and administrativ e concern s d o not warran t th e implementatio n o f thi s alternative

.

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### 6.2. 2 Implementabilit y Alternativ e B i s considere d t o be implementabl e i n term s o f th e technica l feasibility
, 

### administrativ e feasibility
, availabilit y o f service s an d materials , anticipate d agenc y acceptance , an d anticipate d communit y acceptance

. 

### 6.2. 3 Cos t Tota l cost s fo r Alternativ e B ar e estimate d a t $208,039 , an d includ e $113,43 1 fo r direc t capita l costs , $70,32 7 fo r indirec t capita l costs , an d $24,28 1 fo r pos t remova l sit e contro l cost s (presen t worth)

.

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### 7 . 0 REFERENCE

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, S.R.
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, S.T.
, Perkins
, D.M.
, Thenhaus
, P.C.
, an d Bender
, B.L.
, 1990

. Probabilisti c Earthquak e Acceleratio n an d Velocit y Map s fo r th e Unite d State s an d Puert o Rico

. U.S

. Departmen t o f th e Interior
, U.S

. Geologica l Servic e Miscellaneou s Fiel d Ma p MF-2120

. Colorad o Departmen t o f Transportatio n (CDOT)
, 1993

. Cos t Data

. Th e Colorad o Departmen t o f Transportation
, Bi d Plans
, Roo m 117 , 420 1 E

. Arkansa s Ave
, Denver
, Colorad o 80222

. Dame s an d Moore
, 1986

. Stabilit y an d Reclamatio n Evaluatio n o f Abandone d Tailing s Pond s Leadvill e Unit
, Leadville
, Colorado

. Emmons
, S.F.
, J.D

. Irving
, an d G.F

. Laughlin
, 1927

. Geolog y an d Or e Deposit s o f th e Leadvill e Minin g District
, Colorado

. U.S

. Geologica l Surve y Professiona l Pape r 148

. Haan
, C.T.
, Barfield
, BJ

. an d Hayes
, J.C

. Desig n Hydrolog y an d Sedimentolog y fo r Smal l Catchments

. Academi c Press
, Sa n Diego
, CA

. 58 8 p

. Means
, 1993

. Mean s Heav y Constructio n Cos t Data

. R.S

. Mean s Company
, Inc

. 10 0 Constructio n Plaza
, P.O

. Bo x 800 , Kingston
, M A 02364-0800

. Mortorano
, Marily n A

. an d Davi d G

. Killan

. 1990

. Addendu m t o Ya k Tunne l Remedia l Actio n Histori c Resource s Survey
, Lak e County
, Colorado

. O n file a t th e Stat e Histori c Preservatio n Office
, Denver

. Shepher d Miller
, Inc

. (SMTj
, 1994

. Summar y o f Surfac e an d Groun d Wate r Sampling i n Californi a and Orego n Gulc h performe d i n Octobe r 1993

. Shepher d Miller
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. (SMI/TerraMatrix)
,

1994

. Fina l Engineerin g Evaluation/Cos t Analysi s Work Pla n fo r th e Garibald i Min e Sit e (OU-4)

. Shepher d Miller
, Inc./TerraMatri x

Inc

. (SMI/TerraMatrix)
,

1994a

. Draf t Fina l Fiel d Reconnaissance Surve y o f Min e Wast e Pile s Locate d Withi n th e Uppe r Californi a Gulch Drainage

. Shepher d Miller
, Inc./TerraMatrix

Inc

. (SMI/TerraMatrix)
,

1994b

. Summar y o f Wate r an d Sedimen t Sampling an d Hydrologi c Measuremen t i n Californi a performe d i n April
, Ma y an d Jun e 1994

. Shepher d Miller
, Inc./TerraMatrix

Inc

. (SMI/TerraMatrix)
,

1995

. Summar y o f Wate r an d Sedimen t Sampling an d Hydrologi c Measurement s Progra m fo r Californi a Gulc h Performe d i n October
, 1994

.

H:\664\EECA\GARBALD.FN

L 07/27/9 5 4:01p m WP51/cm cfuly

27 , 1995

__________________________________ FINAL * EE/CA Garibaldi Mine Site » 5 2 TerraMatrix Inc./Shepher d Miller
, Inc

. (TerraMatrix/SMI)
,

1994

. Fina l Engineerin g Evaluation/Cos t Analysi s Wor k Pla n fo r th e Garibald i Min e Sit e (OU-4)

. TerraMatrix Inc./Shepher d Miller
, Inc

. (TerraMatrix/SMI)
,

1995

. Draf t Operabl e Unit s 4 , 8 , an d 1 0 Reconnaissanc e Report

. Turk
, J.T

. an d Taylor
, J.O.
, 1979

. Appraisa l o f Ground Wate r i n th e Vicinit y o f th e Leadvilie Drainag e Tunnel
, Lak e County
, Colorado

. U.S

. Geologica l Surve y Ope n Fil e Repor t 79-1538

. Tweto
, O.
, 1970

. Leadvili e District
, Colorado

. In
, MacDiarmid
, R.A.
, ed. , Or e Deposit s o f th e Unite d States

. U.S

. Geologica l Survey

. Washington
, D.C

. pg s 681-705

. U.S

. Arm y Corp s o f Engineers (COE)
, 1991

. HEC- 1 Floo d Hydrograp h Package

. Hydrologi c Engineerin g Center
, Davis
, CA

. U.S

. Departmen t o f Agricultur e - Soi l Conservatio n Servic e (SCS)
, 1980

. Procedure s fo r Determinin g Pea k Flow s i n Colorado

. Technica l Releas e No

. 55

. U.S

. Departmen t o f Commerce
, Burea u o f th e Census
, 1990

. Selecte d Populatio n an d Housin g Characteristics
, 1990

. U.S

. Distric t Cour t (USDC)
, Distric t o f Colorado
, 1994

. Civi l actio n No

. 83-C-2388
, Consen t Decre e wit h ASARCO
, Inc.
, Resurrectio n Minin g Company
, Newmon t Minin g Corporation
, an d th e Res-ASARC O Join t Venture
, Appendi x D : Wor k Are a Managemen t Pla n fo r th e Californi a Gulc h Superfun d Site
, Implementatio n b y Resurrectio n Minin g Company

. May

. U.S

. Environmenta l Protectio n Agenc y (EPA)
, 1987a

. Phas e I Remedial Investigatio n Report
, Californi a Gulch
, Leadvilie
, Colorado

. U.S

. Environmenta l Protectio n Agenc y (EPA)
, 1987b

. Remedial Actio n Costin g Procedures Manual
, Offic e o f Soli d Wast e an d Emergenc y Response
, Washington
, D.C.
, EP A Contrac t 68-03-3113 , EPA\600\8-87\049

, October

. U.S

. Environmenta l Protectio n Agenc y (EPA)
, 1993a

. Fina l Screenin g Feasibilit y Stud y fo r Remedial Alternative s a t th e Californi a Gulc h NP L Site

. Leadvilie
, CO

. September

. U.S

. Environmental Protectio n Agenc y (EPA)
, 1993b

. Guidanc e on Conductin g Non-Time

- Critica l Remova l Action s unde r CERCLA

. Offic e o f Emergenc y an d Remedial Response
, U.S

. Environmenta l Protectio n Agency
, Washington
, D C 20460

. August

. U.S

. Environmenta l Protectio n Agenc y (EPA)
, 1994

. Acid Min e Drainag e Prediction

. Warner
, R.C.
, an d Schwab
, P.J.
, 1992

. SEDCAD + Versio n 3 Trainin g Manual

. Civi l Softwar e 

### Design
, Ames
, IA

. Water
, Wast e an d Land
, (WWL ) 1990

. Californi a Gulc h Hydrologi c Investigatio n Report

. Repor t prepare d fo r Resurrectio n Minin g Company

. H:\664\EECA\GARBALD.FN

L 07/27/9 5 4:01p m W51/cm cJuly

27 , 1995

_________________________________ FINAL * EE/CA Garibaldi Mine Site » 5 3 Weston
, R.F.
, Inc.
, 1994

. Draf t Fina l Baselin e Aquati c Ecologica l Ris k Assessment
, Californi a Gulch
, Leadville
, Colorado

. Woodwar d Clyd e Consultants
, (WCC)
, 1990

. Site Improvement s for : Garibald i Workings ; Nort h Mik e Workings ; Oregon Gulc h Tailin g Pond ; Star r Ditch

. Woodwar d Clyd e Consultants
, Inc

. (WCC)
, 1993

. Hydrogeologi c Remedial Investigatio n Report
, Draft
, Californi a Gulc h Site
, Leadville
, Colorado

. Woodwar d Clyd e Consultants
, Inc

. (WCC)
, 1993a

. Terrestria l Ecosyste m Evaluatio n Report
, Draft
, Californi a Gulc h Site
, Leadville
, Colorado

. Woodwar d Clyd e Consultants
, Inc

. (WCC)
, 199 3 b

. Surfac e Wate r Remedia l Investigatio n Report
, Draft
, Californi a Gulc h Site
, Leadville
, Colorado

. Woodwar d Clyd e Consultants
, Inc

. (WCC)
, 1994

. Fina l Min e Wast e Pile s Remedia l Investigatio n Report

.

H:\664\EECA\GARJBALD.FN

L 07/27/9 5 4:01p m WPSl/cm cJuly

27, 1995 FINAL * EE/CA Garibaldi Mine Site * Drawings



### FIGURES/DRAWING S

HA664\EECA\GARBALD.FN

L 07/27/9 5 4:01p m WP51/cm c

## O

R A D O

CALIFORNIA GULCH SUPERFUND SITE

NOT TO SCALE

Project No.: 664-0 100 File: RESWLOC.DWG /Jrx'U/

n Lly : J.RAY l)ra:nrn By: K.CONRATH RESURRECTIO N

MININ G COMPAN Y O N E UNITE D BAN K CENTE R 170 0 LINCOL N STREE T DENVER
, COLORAD O 8020 3 •Sr.nlv: N/A

Date: JULY 1995 

### FIGURE 1 

## CALIFORNIA

GULCH SITE 

## GENERAL LOCATION

# c

..- PROPOSED \ HAUL ROUTE (Alternativ e D )



### GARIBALDI MINE SITE (Refe r T o Drawin g 1 Fo r Details)
SCALE 0 2,500' 5,000' SCALE r = 5.000' 

### LEGEND N OPERABL E UNI T 4 CGI G SURFAC E WATE R MONITORIN G

LOCATIO N Project

No.: 664-O10O File: OU-AREA4.DWG Design

By: J.RAY Drawn By: T.LEIDICH RESURRECTIO N

MININ G COMPAN Y O N E UNITE D BAN K CENTE R 170 0 LINCOL N STREE T DENVER
, COLORAD O 6020 3 Scale: 1 "

. - 5000' Date: JUL Y 1995 

### FIGURE 2 GARIBALDI

MINE SITE EE/CA 

## OPERABLE UNIT 4

## //- w 

## V\ \ \ \\ \ \

NOTE : CG-1 G Locate d 0 Uppe r Californi a Gulc h & , Lak e Count y Roa d 2 (Show n O n Figur e 2 ) 

# LEGEND

DIVERSIO N DITC H LIMI T O F WAST E ROC K CULVER T PORTA L ACCES S ROA D FLO W DIRECTIO N SURFAC E WATE R MONITORIN G LOCATIO N GROUNDWATE R WEL L

N o

. k G M

-

I iGMWI W

SCAL E 5 0 0 50 100 CONTOU R INTERVAL 5 F l

.
ISSUE D FO R FINA L REPOR T ISSUE D FO R DRAF T REPOR T ISSUE D FO R PRELIMINAR Y

DRAF T UPDATE/REVISE D DRAF T REVISIO N SCALE : SEE BAR SCALE DESIG N BY : T.LEID/CH DRAW N BY: T.LEIDICH CHEC K BY : J.RAY PROJEC T No

. 664-3200 FIL E NAME : GBEXIST.DWC DAT E M G M JM R

BY CHK D 

## CALIFORNIA GULCH 

## SITE PROJECT: 

### Garibald i Min e Site DRAWIN G TITLE : GARIBALDI MINE SITE EXISTING CONDITIONS RESURRECTIO N

MININ G

COMPAN Y O N E UNITE D BAN K CENTE R 170 0 LINCOL N

STREE T DENVER

. COLORAD O

8020 3 SHEET

: 1 O F 1 DRAWIN G No. : REV

. 4

### \ FREEBOAR D = o.s 1 

# LEGEND

TYPICAL UNLINED CHANNEL DIVERSIO N DITC H LIMI T O F WAST E ROC K CULVER T PORTAL ACCES S ROA D FLO W DIRECTIO N ENERG Y DISSIPATO R

-0.33 FREEBOAR D = 0.3 CONCRET

E


# CONCRETE LINED CHANNEL

SCAL E 5 0 0 50 100 CONTOU R INTERVA

L 5 F t

.

-1. 5 x D5 0 

### DIVERSION DITCH SCHEDULE DITC H

1 2 3 4 UPPE R 4 LOWE R PEAK DISCHARG E (CFS ) 0. 4 23. 0 11. 0 39. 0 62. 0 SID E SLOP E 2Hi1 V 2H:1 V 2H:1 V 2H:1 V 2H:1 V CHANNE L SLOP E ( % ) 2 2 1 7 1 6 1 1 VELOCIT

Y (FPS ) 1. 4 8. 7 7. 4 21. 4 21. 3 FLO W DEPT H (FT ) 0. 1 0.8 0.5 0. 6 0. 8 LINE R TYP E GRASS CONCRET E RIPRA P D50=6 " CONCRET E CONCRET E i-FREEBOAR D = 0.3 1 r———

— RIPRAP



### TYPICAL RIPRAP LINED CHANNEL DRAWIN G No

. WHER E • DETAIL/SECTIO N I S REFERENCE D -DETAIL/SECTIO N

NUMBE R
DETAIL/SJECTIO N IS SHOW N 

## 7K

N o

. ISSUE D

FO R FINA L REPOR T ISSUE D FO R DRAF T REPOR T ISSUE D FO R PRELIMINAR Y

DRAF T UPDATE/REVISE D REVISIO N SCALE : see BAR SCALE DESIG N BY : T.LEIDICH DRAW N BY : T.LBD/CH CHEC K BY : J.RAY PROJEC T No

. 664-3200 FIL E NAME : GBAL TIDWC DATE T E L J M R B Y CHK D 

## CALIFORNIA GULCH 

## SITE PROJECT : 

### Garibald i Min e Sit e DRAWIN G TITLE : GARIBALDI MINE SITE AL TERNA TIVE A RESURRECTIO N

MININ G COMPAN Y O N E UNITE D BAN K CENTE R 170 0 LINCOL N

STREE T DENVER
, COLORAD O

8020 3 SHEET

: 1 O F * DRAWIN G No. : 2 REV

. 4

### DIVERSION

DITCH SCHEDULE DITC H
1 2 3 4 UPPE R 4 LOWE R PEAK DISCHARG E (CFS ) 0.4 23. 0 11. 0 39. 0 62. 0 SID E SLOP E 2H:1 V 2H:1 V 2H:1 V 2H:1 V 2H:1 V CHANNE L SLOP E (54 ) 2 2 1 7 1 6 1 1 VELOCIT

Y (FPS ) 1.4 8. 7 7. 4 21. 4 21. 3 FLO W DEPT H (FT ) 0. 1 0.8 0.5 0. 6 0.8 LINE R TYP E GRASS CONCRET E RIPRA P D50=6 " CONCRET E CONCRET E FREEBOAR D = 0.3 RIPRA P



### TYPICAL RIPRAP LINED CHANNEL 

# LEGEND

CLEA N GRAVE L
- HOP E LINER

- DITC H DIVERSIO N DITC H LIMI T O F WAST E ROC K CULVER T PORTAL ACCES S ROA D GROUNDWATE R TRENC H PIP E FLO W DIRECTIO N ENERG Y DISSIPATO R

SLOTTE D PV C PIP E BEDROC K Note : (Intercepto r Trenc h Will B e Keye d Int o Bedroc k A s Condition s Allow) 

### ^\GROUNDWATER

INTERCEPTOR

TRENCH

v 3 3 1 

# L FREEBOAR D = 0.3

• 2'

- 

### TYPICAL UNLINED CHA NNEL DRAWIN

G No

. WHER E • DETAIL/SECTIO N I S REFERENCE D CONTOU R INTERVA

L 5 F l

. -DETAIL/SECTIO N NUMBE R
DRAWIN G No

. WHER E DETAIL/SECTIO N I S SHOW N

FREEBOAR D = 0.3 CONCRETE

-



### TYPICAL CONCRETE LINED CHANNEL ZL

\

N o

. ISSUE D

FO R FINA L REPOR T ISSUE D FO R DRAF T REPOR T ISSUE D FO R PRELIMINAR Y

DRAF T UPDATE/REVISE D REVISIO N SCALE : SEE BAR SCALE DESIG N BY : T.LSDICH DRAW N BY : T.LEDICH CHEC K BY : J.RAY PROJECT No

. 664-3200 FIL E NAME : GBAL T2.DWG DATE B Y CHK D 

## CALIFORNIA GULCH 

## SITE PROJECT : 

### Garibald i Min e Sit e DRAWIN G TITLE ; GARIBALDI MINE SITE AL TERNA TIVE B RESURRECTIO N

MININ G COMPANY O N E UNITE D BAN K CENTE R 170 0 LINCOL N

STREE T DENVER

. COLORAD O

8020 3 SHEET

: t O F 7 DRAWIN G No. : 3 REV

. 41 8 " O F LO W PERMEABILIT

Y MATERIA L 

# LEGEND

TYPICAL SIMPLE COVER

CLEA N COBBLE

- HOP E LINER

-
DITC H DIVERSIO N DITC H LIMI T O F WAST E ROC K CULVER T PORTAL ACCES S ROA D GROUNDWATE R TRENC H PIP E REGRADE D TOPOGRAPH Y FLO W DIRECTIO N ENERG Y DISSIPATO R • 1H2S

C.'^'^ J V^^E 1 SLOTTE D PV C PIP E

Note : (Intercepto r Trenc h Will B e Keye d Int o Bledroc k A s Condition s Allow) 

### ^GROUNDWATER

INTERCEPTER

TRENCH

FREEBOAR D = 0.3 CONTOU R INTERVA

L 5 F t

. 

### TYPICAL UNLINED. CH/-NNEL DRAWIN G NO

. WHER E • DETAIL/SECTIO N IS REFERENCE D -DETAIL/SECTIO N NUMBE R
DRAWIN G No

. WHER E DETAIL/SECTIO N I S SHOW N

MATERIA L MOVEMEN T
- 310 0 C Y ARE A O F DISTURBANC E

- 1. 6 ACRE S 

### DIVERSION DITCH SCHEDULE DITC H
1 2 3 4 UPPE R 4 LOWE R PEAK DISCHARG E (CFS I 0.4 23. 0 11. 0 39. 0 62. 0 SID E SLOP E 2H:1 V 2H:1 V 2H:1 V 2H:1 V 2H:1 V CHANNE L SLOP E (%) 2 2 M 1 6 1 1 VELOCIT

Y (FPS) 1. 4 8.7 7. 4 21. 4 21. 3 FLO W DEPT H (FT) 0. 1 0.8 0. 5 0. 6 0. 8 LINE R TYP E GRASS CONCRET E RIPRA P D50=6 " CONCRET E CONCRET E FREEBOAR D = 0.3 RIPRA P FREEBOAR D = 0.3 

### CONCRETE

-



### TYPICAL RIPRAP LINED CHANNEL ^2\TYPICAL

CONCRETE LINED CHANNEL 

### 7\ 7K Z \ N o

. ISSUE D

FO R FINA L REPOR T ISSUE D FO R DRAF T REPOR T ISSUE D FO R PRELIMINAR Y

DRAF T UPDATE/REVISE D DRAF T REVISIO N SCALE : see BAR SCALE DESIG N BY : T.LEIDICH DRAW N BY : T.LEIDICH CHEC K BY : J.RAY PROJECT No

. FIL E NAME : GBAL T3.DWG DAT E B Y CHK D 

## CALIFORNIA GULCH 

## SITE PROJECT : 

### Garibald i Min e Site DRAWIN G TITLE : GARIBALDI MINE SITE ALTERNATIVE C RESURRECTIO N

MININ G COMPAN Y O N E UNITE D BAN K CENTE R 170 0 LINCOL N

STREE T DENVER

. COLORAD O

8020 3 SHEET

: 1 O F 1 DRAWIN G No. : 4 REV

. 4

# r

NOTE : VOLUM E O F WAST E ROC K REMOVE D 27,90 0 C Y 

# LEGEND

RE-ESTABLISHE D CHANNE L
— • • — • LIMI T O F WAST E ROC K
— — - - CULVER T >——

< PORTAL >———

— ACCES S ROA D ~

~ ~ PRE-MIN E TOPOGRAPH

Y ——n«s

- FLO W DIRECTIO N

SCAL E 0_______S O ^^^ Z CONTOU R INTERVA L 5


## 7\ No. ISSUE D

FO R FINA L REPOR T ISSUE D FO R DRAF T REPOR T ISSUE D FO R PRELIMINAR Y

DRAF T UPDATE/REVISE D DRAF T REVISIO N SCALE : SEE BAR SCALE DESIG N BY : r.LBOICH DRAW N BY: T.LEID/CH CHEC K BY : J.RAY PROJECT No

. BBi-3200 FIL E NAME : GBAL TJ.DWG 7/9 5 MG M JM R

DAT E B Y CHK D 

## CALIFORNIA GULCH 

## SITE PROJECT : 

### Garibald i Min e Sit e DRAWIN G TITLE : GARIBALDI MINE SITE ALTERNATIVE D RESURRECTIO N

MININ G COMPAN Y O N E UNITE D BAN K CENTE R 170 0 LINCOL N

STREE T DENVER

. COLORAD O

8020 3 SHEET :

1 O F 1 DRAWIN G No. : 5 REV

. 4July

27, 1995 FINAL * EE/CA Garibaldi Mine Site * Attachments



### ATTACHMENT S

H:\664\EECA\GARIBALD.FN

L 07/27/9 5 5:36p m WP51/cm c

### ATTACHMEN T 1 RESPONS E T O PUBLI C COMMENT S Response s t o comment s o n th e Draf t Engineerin g Evaluatio n an d Cos t Analysi s fo r Garibald i Min e Site Withi n Uppe r Californi a Gulc h Operabl e Uni t 4 (EE/CA ) ar e presente d o n th e following pages

. Th e EE/C A was submitte d t o th e EP A an d th e Colorad o Departmen t o f Publi c Healt h an d Environmen t (CDPHE ) o n Jun e 2, 1995 , an d was availabl e fo r publi c revie w and commen t fro m Jun e 5 , 199 5 t o Jul y 7 , 1995

. Comment s o n the EE/C A wer e receive d fro m the CDPH E an d the Burea u o f Reclamatio n o n Jul y 11, 199 5 and fro m the Lak e Count y Boar d o f Count y Commissioner s o n Jul y 13 , 1995

.

H:\664\gmssub.It r 07/27/9 5 4:48p m WP51/cm c

# Unite d

State s Departmen t o f th e Interio r



# - BUREA U O F RECLAMATIO N R*olMUktto » Sctvit * Ovoto r P.O

. Bu t 8500 7 6 T
, Dcaw r F«d«r* l Ctott r

, Cctend o SCOS-COO ? 

### ENV-3.0 0 

## JUN3 0

199 S Environmenta l Protectio n Agen c 

## Attention : MS

. Denis e Lin k 

## Reroedia l Projec t Manage r Regio n VTII
, Suit e 50 0 

## 999 isc h stree t Denve r C O 8020 2 Dea r Ms

. Link ; Thank yo u for the opportunit y t o revie w the Pi-af t Ena i 

## t Analvsijs fo r Garibald i Mia e Site Withi n (EE/CA ) prepare d b y 

### Shepherd-ltille r Inc . , and TerraMatri x . I hav e the lollowin g 

### conmetnt: Sectio n 4

. S.I

. 3

. Refractin g /Simpl e Covw i

. Thi s auctio n 

## references Drawin g 4 an d states tha t 3K:1 V slope s are shown

. I d o not find
, thi a 3: 1 elop e clearl y indicate d 

### on th e drawing , th e slope s withi n th e propose d channel s appea r t o retai n th e 2H:1 V slope s fro m previous 

## drawing s
. Sectio n 4.6.1

. Descriptio n o f Alternativ e D

. Thi s alternativ e woul d requir e the conduc t o f additiona l 

### cultura l resourc e inventor y and evaluatio n fo r the roa d 

### improvement s an d th e ne w roa d construction

. This i s no t 

## identifie d withi n th e discussion

. Tfc e discussio n shoul d LuwiuU e a . sectio n relativ e t o thi s worf c and a discussio n 

## tha t increase d cost s wil l b e adde d pe r th e cultural resourc e requirements , i f new roa d constructio n wil l requir e a roadwa y t o accommodat e two-wa y traffic
, rather 

## tha n jus t on e traffi c direction , i f additiona l turnout s o r stagin g area s wil l b e involved , thes e wil l requir e cultural resourc e work

. Complianc e wit h Sectio n 10 6 o f 

### th e Nationa l Histori c Preservatio n Ac t wil l b e require d fo r improvement s and/o r ne w construction

. N o drawin g o f 

## th e propose d rout e i s included

. I f Shepherd-Mille r an d 

## TerraMatri x hav e bee n abl e t o stat e tha t constructio n o f
a ne w hau l roa d woul d "provid e a shorte r hau l route. 1 

### I 

## assum e a propose d rout e ha s bee n identified

. Thi s shoul d b e included

.

## Sectio n

4.6.2.2

. Administrativ e

Feasibility
, it woul d bo helpfu l t o includ e a statemen t detailin g that fo r 

### Alternativ e D
, additiona l administrativ e

issue s 

### pertinen t t o cultura l resource s wil l b e required

. Specifically
, plannin g fo r Sectio n 10 6 compliance

. 

### sectio n 6.1

. Pag e 48

. Spelling Error : Conditio n i s misspelled

. 

### Appendi x F
, F.2. 4 Cultura l Resources

. Th e firs t paragrap h shoul d b e corrected t o stat e th e remova l 

## actio n i s a n "undertakin g unde r th e NHPA. " Th e statement : "EP A ha s however , mad e a preliminar y determinatio n tha t resource s withi n th e are a potentiall y 

## effecte d b y the propose d remova l actio n are not eligibl e fo r inclusio n in th e Nationa l Registe r o f Histori c 

## Places. 8 

## shoul d be reworded

. Th e lette r th e Colorad o Stat e Histori c Preservatio n

Office r (SHPO ) provide d i n 

## whic h th e SHP O determine d th e Garibald i Mine Site 'no t individuall y eligible , .. . no t withi n th e existin g 

## Leadvill e Histori c Distric t an d

.. . no t contribut e t o distric t expansion doe

s no t clarif y i f A3ARC O wa s 

### requeste d t o submi t thi s material t o th e SHP O fo r EPA

. However
, a s SP A doe s no t wis h t o disput e the ) 

## determinatio n mad e b y th e SHPO / EP A na y now utiliz e thi s determinatio n t o conclud e th e Sectio n 10 6 process , fo r 

## thi s individua l site

. Th e determinatio n i s fina l no t preliminary

. 

## i n th e nex t paragrap h th e Historica l an d Archaeologica l Preservatio n Ac t o f 197 4 i s incorrectl y identified

. Th e wor d Dat a need s t o b e deleted

. 

## F.2.6

. Clea n wate r Ac t (Sectio n 404)

. i s th e •National permi t discusse d her e a Sectio n 40 4 Permi t o r a Nationwid e Permit ? 

## Tabl e F.I

. Archaeologica l an d Historica l Preservatio n Ac t shoul d be correctl y identified

. Delet e Dat a fro m 

## th e title

. Th e Histori c Site s Ac t o f 193 5 i s include d withi n thi s tabl e bu t n o discussio n o f thi s i s presen t 

### i n th e text

. 

## Appendi x G

. Coa t Estimates

. Al l cos t estimate s hav e include d Cultura l Resources
, identifie d a s a lum p sum 

## payment * amoun t ($10,000 ) an d sourc e a s previou s projects

. Fo r Alternativ e A
, n o histori c propertie s ar e 

## involved i n th e on-sit e constructio n for ditche s 1-4

. An y cultural resourc e wor k woul d onl y b e necessit y fo r 

## the 50 0 fee t o f improvement , regradin g and blading , t o th e existin g road

. Th e amoun t ($10,000 ) allocate d her e

### for

cultura l resourc e wor k appear s t o b e excessive , i n fact
, i f roa d improvement s ar e confine d t o th e rereadin g 

## an d bladin g wit h n o increase i n roadwa y width , then cultura l resourc e wor k ma y b e eliminate d altogether

. The initia l constructio n

o f the roa d ma y hav e destroye d 

## th e potentia l fo r significan t cultura l propertie s t o be present

. 

## Agai n fo r Alternativ e B
, the sam e level s o f cost s ar e identified

- fo r cultura l resources
. Revie w o f Alternativ e B indicate s that on-siL e wor k wil l b e 

## confine d t o area s previousl y include d i n cultura l resourc e inventor y an d evaluation

. Roa d improvement s are anticipate d L o b e th e sam e a s Alternativ e A

. M y 

## previou s commen t relativ e t o th e amoun t ($10,000 ) applie s her e also , 

### Alternativ e C na y als o b e include d i n m y commen t o n th e 

### costs

. Alternativ e D i s exactl y th e sam e a s th e others , $10,00 0 i s targete d fo r cultura l resource s work

. Alternativ e D 

## wil l requir e additiona l cultura l resourc e work , reportage , and additiona l tim e for EP A L o initiat e and 

## conclud e th e Sectio n 10 6 process

. Doe s th e amoun t indicate d her e provid e Cor th e conduc t o f thi s new wor k 

## o r ha s th e amoun t allocate d simpl y bee n carrie d forwar d 

## wit h littl e thought Co r actua l expenses ? I hav e one correction t o commen t provide d Cor the BE/C A for 

## th e Colorad o Zinc-Lea d Tailin g Area
, lette r date d 2 3 Jun e 1995

. in sectio n 1.4 , m y sentenc e reading : 'Th e discussio n her e need s t o b e revise d t o indicat e th e remova l actio n fo r 

## th e tailing s wil l onl y effec t sit e 5LK845; " shoul d b e reworde d to : Th e discussio n her e need s t o b e revise d t o indicat e th e remova l actio n wil l onl y effec t Featur e D o f sit e 5LK845

. I loo k forwar d t o continuin g t o wor k wit h yo u an d 

### Resurrectio n Minin g Compan y aa thi s projec t move s forward

. Shoul d yo u hav e questions regardin g thes e conraontc , pleas e 

### cal l m e a t 236-2722 extensio n 341

. 

## Sincerely
, 

# &- Patrici a McCc y O Cultura l Resourc e Sp«ci«lia u 

### Technica l Servic e Cente rJuly

24, 1995

_______________________________________ Comment Responses * OU-4

__ BUREA U O F RECLAMATIO N COMMENT S
1

. Comment: Sectio n 4.5.1.3

. Regrading/Simpl e Cover

. Thi s sectio n reference s drawin g 4 and state s tha t 3H:1 V slope s ar e shown

. I d o not fin d thi s 3: 1 slop e clearl y indicate d
o n th e drawing

. Th e slope s withi n th e propose d channel s appea r t o retain th e 2H:1 V slope s fro m previou s drawings

. Response : Th e drawin g wil l be clarifie d t o indicat e a 3: 1 slope

. 2

. Comment: Sectio n 4.6.1

. Descriptio n o f Alternativ e D

. Thi s alternativ e woul d requir e th e conduc t o f additiona l cultura l resource inventor y an d evaluatio n fo r th e roa d improvement s an d th e ne w roa d construction

. Thi s i s no t identifie d withi n th e discussion

. Th e discussio n shoul d includ e a sectio n relativ e t o thi s wor k an d a discussio n tha t increase d cost s wil l be adde d pe r th e cultura l resourc e requirements

. I f ne w roa d constructio n wil l requir e a roadwa y t o accommodat e two-wa y traffic
, rathe r than jus t on e traffi c direction , i f additiona l turnout s o r stagin g area s wil l b e involved , thes e wil l requir e cultura l resourc e work

. Complianc e wit h Sectio n 10 6 o f th e Nationa l Histori c Preservatio n Ac t wil l b e required fo r improvement s and/o r ne w construction

. N o drawin g o f th e propose d rout e i s included

. I f Shepherd-Mille r an d TerraMatri x hav e bee n abl e t o stat e tha t constructio n o f a ne w hau l roa d woul d "provid e a shorte r hau l route, " I assum e a propose d rout e ha s bee n identified

. Thi s shoul d b e included

. Response : Th e descriptio n o f Alternativ e D wil l b e enhance d t o discus s potentia l cultura l resource s requirement s associate d wit h th e implementatio n o f th e alternative

. Cost s wil l be update d t o includ e th e appropriat e leve l o f cultura l resource s wor k anticipate d fo r thi s alternative

. A drawin g wil l b e provide d indicatin g th e propose d hau l route

. 3

. Comment : Sectio n 4.6.2.2

. Administrativ e Feasibility

. I t woul d be helpfu l t o includ e a statemen t detailin g tha t fo r Alternativ e D
, additiona l administrativ e issue s pertinen t t o cultura l resource s wil l b e required

. Specifically
, plannin g fo r Sectio n 10 6 compliance

. Response : A statemen t pertainin g t o additiona l administrativ e issue s associate d wit h cultura l resource s wil l b e adde d t o thi s section

. 4

. Comment : Sectio n 6. 1 Pag e 48

. Spellin g Error : Conditio n i s misspelled

. Response : Th e misspellin g wil l b e corrected

. 5

. Comment : Appendi x F
, F.2.4

. Cultura l Resources

. Th e firs t paragrap h shoul d b e corrected t o stat e the remova l action i s an "undertakin g under the NHPA. " The statement : "EP A ha s however , mad e a preliminary determinatio n tha t resource s withi n th e are a potentiall y effecte d b y th e propose d remova l actio n ar e no t eligibl e fo r inclusio n i n the Nationa l Registe r o f Histori c Places. " shoul d b e reworded

. The lette r the Colorad o Stat e Histori c Preservatio n Office r (SHPO ) provide d i n whic h th e SHP O determine d th e Garibald i Min e Sit e "no t individuall y eligible,..

. no t within th e existin g Leadvill e Histori c Distric t and...no t contribut e t o distric t expansion " doe s no t clarif y i f ASARC O was requeste d t o submi t thi s materia l t o th e SHP O fo r EPA

. However
, as EP A doe s not wis h t o disput e the determinatio n mad e b y the SHPO
, EP A ma y not

H:\664\COMMENTS-RS

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24, 1995

______________________________________ Comment Responses * OU-4 utiliz e this determinatio n t o conclud e th e Sectio n 10 6 process , fo r this individua l site

. T h e determinatio n i s fina l no t preliminary

. I n th e nex t paragrap h th e Historica l an d Archaeologica l Preservatio n Ac t o f 197 4 i s incorrectl y identified

. Th e wor k Dat a need s t o b e deleted

. Response : Appendi x F
, Sectio n F.2. 4 wil l b e revised a s suggested

. 6

. Comment: F.2.6

. Clea n Wate r Ac t (Sectio n 404)

. I s th e "National " permi t discusse d her e a Sectio n 40 4 Permi t or a Nationwid e Permit ? Response : Th e wor d "National " wil l b e replace d wit h th e wor k "Nationwide"

. 7

. Comment : Tabl e F.I

. Archaeologica l an d Historica l Preservatio n Ac t shoul d be correctl y identified

. Delet e Dat a fro m th e title

. Th e Histori c Site s Ac t o f 193 5 i s include d withi n this tabl e bu t n o discussio n o f this i s presen t i n th e text

. Response : "Data " wil l b e delete d fro m th e titl e o f th e Archaeologica l an d Historica l Preservatio n Act

. Th e Histori c Site s Ac t o f 193 5 wil l be delete d fro m th e table

. 8

. Comment : Appendi x G

. Cos t Estimates

. Al l cos t estimate s hav e include d Cultura l Resources
, identifie d a s a lum p sum payment , amoun t ($10,000 ) and source a s previou s projects

. Fo r Alternativ e A
, n o histori c propertie s ar e involve d in th e on-sit e constructio n fo r ditche s 1-4

. An y cultura l resource wor k woul d onl y be necessar y fo r th e 50 0 fee t o f improvement , regradin g an d blading , t o th e existin g road

. Th e amoun t ($10,000 ) allocate d her e fo r cultura l resourc e wor k appear s t o be excessive

. I n fact
, i f
roa d improvement s ar e confine d t o th e regradin g an d bladin g wit h n o increas e i n roadwa y width , the n cultura l resourc e wor k ma y be eliminate d altogether

. Th e initia l constructio n o f th e roa d ma y hav e destroye d th e potentia l fo r significan t cultura l propertie s t o b e present

. Agai n fo r Alternativ e B
, th e sam e level s o f cost s ar e identifie d fo r cultura l resources
. Revie w o f Alternativ e B indicate s tha t on-sit e wor k wil l b e confine d t o area s previousl y include d i n cultura l resourc e inventor y and evaluation

. Roa d improvement s are anticipate d t o b e th e sam e a s Alternativ e A

. M y previous commen t relativ e t o th e amoun t ($10,000 ) applie s her e also

. Alternativ e C ma y als o b e include d i n m y commen t o n th e costs

. Alternativ e D i s exactl y the sam e a s the others , $10,00 0 i s targete d fo r cultura l resource s work

. Alternativ e D wil l requir e additiona l cultura l resourc e work , reportage , an d additiona l tim e fo r EP A t o initiat e an d conclud e th e Sectio n 10 6 process

. Doe s th e amoun t indicate d her e provid e fo r th e conduc t o f thi s ne w wor k o r ha s th e amoun t allocate d simpl y bee n carrie d forwar d wit h littl e though t fo r actua l expenses ? Response : Th e cost s wil l b e adjuste d t o reflec t th e relativ e difference s i n th e scop e o f th e cultura l resource s activitie s unde r eac h Alternative

.

H:\664\COMMENTS.RS

P 07/27/9 5 4:25p m WP51/cm c

# STAT

E O F COLORAD O

Rw y K.H.rrt
, O~«- i i* * • • ^ Jfl! ^ » - r , Actin g ExecuCv * Dtre«fe r -

/ Pt f ?

. A v <''''' 4300U*nyu««kL>r>

.

22 2 5

. « h *n m tow n 23 2 Dcn«r

. Colorad o W222-153 0 ^JgjdSoM^d

o 9 1 501-2766

. ^

Coloiad

o Pt»fl « 003 ) 692-3300 

### nu t ciwifofunco t 

## M y 6 , 199 5 Ms

. Denis e Lin k Remedia l Projec t Maoager-^HM-S R 

## California Gulc h Sit e U.S

. EPA
, Regio n Vi n 99 9 18t h Street
, Suit e 5U O 

## Denver
, Colorad o 80202-240 5 RE: CDPH E Comment s on tb e Followin g Resurrectio n Minin g Compan y EE/CAs : -Draf t EE/C A for tb » Garibald i Min e Sit e i s Upper 

## California Chilct (OU-4) ; -Draf t EE/C A fo r th e Colorad o Zinc-Lea d Tailin g Are a 

## i n Lowe r California Gulc h (OU-8)

. Dea r Ms

. Link : 

### Attache d are the CDPH E comment s for the above-referenced EE/CAs

. Thes e comment s 

## ar e i n additio n t o thos e submitted t o EP A o n Ma y 26,1995 , pertainin g t o tb e Preliminar y Draf t version s o f the ED/CA»

. Filia l dispositio n o f A c EE/C A ARAR s Usue*
, and th » 

## comment s regardin g such , wil l b e forthcomin g subsequen t t o furthe r discussion b y EP A an d the CDPHE

. 

## I f yo u hav e an y questions, pleas e don' t hesitat e i n callin g m e a t 692-3382

. Sincerely

. /\ 

# UUUU«s
— Rus s Alie n 

## Hazardou s Material s an d Wast e Managemen t Divisio n

cc : Gar y Herbert
, CBRCLA-AO O 

## Do n Deere
, RM C

### CDPH

E COMMENTS : DRAF T EE/CA

. GARIBALD I MIN E SIT E UPPE R CALIFORNI A GULCH
, OU-4 JUN E 199 5 (TERR A MATRI X & SHEPHER D MILLE R FOR RESURRECTIO N MINING ) GENERA L COMMENTS



## 1

. The effectivenes s o f thi s EE/CA
, i n satisfactoril y achievin g fina l sitewid e wate r qualit y AJRAR s (whe n addressed i c OU-12)
, canno t b e adequatel y 

### evaluated unti l al l F S remedia l actio n performanc e criteria , a s presente d i n tn e Ressurectio n WAM P (i.e.,surfac e erosiona l stability , slop e stability , flo w 

### capacit y an d stability , surfac e wate r an d groun d wate r loadin g reduction, terrestrial ecusystc m exposure , an d non-residentia l soils)
, hav e bee n quontotativel y assessed

. Accordingly
, the CDPH E concur ? wit h Resurrection' s 

### assertio n (pag e I
, las t paragraph ; and pag e 2

. fus t paragraph ) tha t clean-u p conducted unde r thi s ht/C A i s no t intended t o b e a fina l actio n bu t rathe r a n interi m actio n tha t i s intended t o contribut e t o th e efficien t performanc e o f futur e remedia l action s for OU-4

. The Recor d o f Dtxbiu u (ROD ) for OU- 4 ma y determin e tha t furthe r clean-u p action s wil l b e require d b y 

### Resurrectio n Minin g (a t th e Garibald i Min e Site ) pursuan t t o th e Consen t Decre e i n settlement o f Civi l Actio n No

. 86-C-167 5 (consolidate d wit h Civi l Actio n No

. 83-C-2388)

. 

### 2

. CDPII E previousl y commmente d (Ma y 25,199 5 correspondence t o EPA ) tha t 

## th e 2: 1 sid e slopes o n th e ripra p line d channel s wer e to o stee p an d tha t the y shoul d b e n o steepe r tha n 3:1

. Th e Draf t EE/C A continue s t o sho w sid e dope s a t 2:1 , accordingly , pleas e demonstrat e th e stabilit y an d provid e rational e for th e use o f thes e stee p sid e slopes

. 

### 3

. Th e EE/C A shoul d b e expande d t o demonstrat e ho w di e effectivenes s o f thi s interi m actio n wil l b e evaluated

.July

24, 1995

________________________________________ Comment Responses * OU-4 COLORAD O DEPARTMEN T O F PUBLI C HEALT H AN D ENVIRONMEN T COMMENT S 1

. Comment : Th e effectivenes s o f thi s EE/CA
, in satisfactoril y achievin g fina l site-wid e wate r qualit y ARARs (when addresse d i n OU-12)
, canno t b e adequatel y evaluate d unti l a l l F S remedia l actio n performanc e criteria , as presente d i n th e Resurrectio n WAM P (i.e..
, surfac e erosiona l stability , slop e stability , flo w capacit y an d stability , surfac e wate r an d groun d wate r loadin g reduction , terrestria l ecosyste m exposure , an d non-residentia l soils)
, hav e bee n quantitativel y assessed

. Accordingly
, th e CDPH E concur s wit h Resurrection' s assertio n (pag e 1 , las t paragraph ; an d pag e 2, firs t paragraph ) tha t clean-u p conducte d unde r thi s EE/C A i s not intende d t o b e a fina l actio n but rathe r an interim actio n tha t i s intende d t o contribut e th e efficien t performanc e o f futur e remedia l actions fo r OU-4

. T h e Recor d o f Decisio n (ROD ) fo r OU- 4 ma y determin e tha t furthe r clean-u p actions wil l be require d b y Resurrectio n Minin g (a t th e Garibald i Min e Site ) pursuan t t o th e Consen t Decree in settlemen t o f Civi l Actio n No

. 86-C-167 5 (consolidate d wit h Civi l Actio n No

. 83-C-2388)

. Response : Thi s commen t require s no response

. 2

. Comment: CDPH E previousl y commente d (Ma y 26 , 199 5 correspondenc e t o EPA ) tha t -the 2: 1 sid e slope s o n th e ripra p line d channel s wer e to o stee p an d tha t the y shoul d b e n o steepe r than 3:1

. Th e Draf t EE/C A continue s t o sho w sid e slope s a t 2:1 , accordingly , pleas e demonstrat e th e stabilit y an d provid e rational e fo r th e su e o f thes e stee p sid e slopes

. Response : A s discusse d i n the commen t response s t o you r Ma y 26 , 199 5 correspondenc e wit h EPA
, due t o are a constraints , th e side-slope s hav e bee n designe d a t a 2: 1 slope

. A detaile d surve y o f th e Garibald i sit e i s presentl y underwa y fo r us e durin g remedia l desig n activities

. I f sufficien t are a i s available , th e remedia l desig n wil l reflec t a 3: 1 slope , a s suggested

. Otherwise
, stabilit y o f th e 2: 1 sid e slope s wil l be demonstrated

. 3

. Comment : Th e EE/C A shoul d be expande d t o demonstrat e ho w th e effectivenes s o f this interim actio n wil l be evaluated

.

0 Response : Pe r th e Consent Decre e an d WAMP
, no water qualit y standard s fo r thi s interi m actio n ar e permitted

. A s discusse d i n the commen t response s t o you r Ma y 26 , 199 5 correspondenc e wit h EPA
, Pre-EE/C A water qualit y i s presentl y bein g monitore d
at the Garibald i site

. Post-EE/C A wate r qualit y wil l b e monitore d at the sam e site s followin g procedure s se t fort h i n th e Work Plan fo r a Water an d Aquatic Biological Sampling Program fo r Upper Arkansas River/California Gulch. Flo w an d wate r qualit y monitorin g wil l continu e afte r implementatio n o f th e Remova l Actio n i n orde r t o asses s th e effectivenes s o f th e Remova l Action

. Particula r emphasi s wil l b e place d upo n flo w 

### a t th e toe o f th e pile

.

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# BOAR

D O P 

# cocmn r Jul y 7,1995

Demis e Lin k 

## U.S

. Environmenta l Protection Agenc y 8HWM-S R 99 9 Eighteent h Street
, Suit e 50 0 

## Denver
, Colorad o 80202-246 6 Re : Draf t Engineerin g Evaluation/Cos t Analysi s For Hi e Garibald i Min e Sit e Dea r Ms

. Unk; W e appreciat e th e opportunit y t o commen t on th e Draf t Engineerin g Kvaluation/Cos f 

### Analysi s fo r Th e Garibald i Min e Site

. I n genera l w e ar e i n agreemen t wit h th e 

## Recommende d Remova l Action
, Alternativ e B

. Th e historica l significanc e o f th e Garibald i wast e rock , a s wal l a s th e othe r wad e roc k pile s include d i n di e Californi a 

## Gulc h Superfun d Site
, requir e tha i thes e area s b e preserve d Alternativ e B accomplishe s thi s objectiv e whic h i s important t o th e heritage an d econom y o f ou r community

.

Vcc : Lak e Comit y 

### Pea l v . 

## Your

s ver y truly , 

## fame s E

. Mattin g ^P ^ 

## Lak e Count y Commissioner Rober t W Lak e Count y 

### Ear l B 

## Lak e Count y COMMISSIONER S fi

. Martin-Chairman

.

Rober t W

. CWM ? • Ear i Boev e • timoth y H

- Berry-Count y Attorne y

— muni

. m* > 4MMMM S • Fa x (Tit ) 4£e-397 S TOTfl L P.84July

24, 1995

________________________________________ Comment Responses * OU-4 LAK E COUNT Y BOAR D O F COUNT Y COMMISSIONER S
1

. Comment : W e appreciat e th e opportunit y t o commen t o n th e Draf t Engineerin g Evaluation/Cos t Analysi s fo r th e Garibald i Min e Site

. I n general w e ar e in agreemen t wit h th e Recommende d Remova l Action
, Alternativ e B

. Th e historica l significanc e o f th e Garibald i wast e rock, a s wel l a s th e othe r wast e roc k pile s include d i n th e Californi a Gulc h Superfun d Site
, requir e tha t thes e area s b e preserved

. Alternativ e B accomplishe s this objectiv e whic h i s importan t t o th e heritag e an d econom y o f ou r community

. Response : Thi s commen t require s n o response

.

H:\664\COMMENTS.RS

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27, 1995 FINAL * EE/CA Garibaldi Mine Site * Appendices



### APPENDI X A 

### STAT E HISTORI C PRESERVATIO N 0TMFIC E LETTE R

H:\664\EECA\GARBALD.FN

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# COLORAD O

HISTORICA L SOCIET Y The Colorad o Histor y Museu m 130 0 Broadwa y Denver

. Colorad o 80203-213 7 Augus t 31 , 199 0 Glen n Anderso n ASARC O 101 9 8t h Street
, Suit e 30 4 Golden
, Colorad o 8040 1 R e : Res-ASARC O Join t Ventur e Draf t Cultura l Resource s Repor t Dea r Mr

. Anderson : W e hav e reviewe d draf t informatio n fo r th e abov e repor t an d hav e th e followin g comment s abou t th e component s o f thi s undertaking : Wel l Site s (#1, *2

. # 3 an d *6 )
- Th e informatio n satisfactoril

y document s th e lac k o f histori c propertie s i n thes e locations

. Therefor e w e anticipat e tha t ther e wil l b e n o effec t o n histori c properties

. Nort h Mik e Working s - I t i s ou r opinio n that thi s i s a contributin g element o f th e Adelaid e sit e (5LK709)
, whic h ha s bee n determine d eligibl e fo r inclusio n in th e Nationa l Registe r o f Histori c Places

. W e fin d tha t th e nature o f th e propose d sit e improvemen t projec t wil l hav e n o effec t o n th e qualitie s o f significanc e o f th e histori c property

. Oregon Gulc h Tailing s Pon d fSUC382 )
- W e ca n fin d n o recor d o f a determinatio n o f eligibilit y fo r th e Resurrection

Hill/Ya k Tunne l Site

. However
, the Resurrectio n

Site s (5LX700)
, whic h ar e not i n the vicinit y o f thi s tailing s pon d or the mil l site , hav e bee n determine d eligible

. The pond and the larg e collectio n o f uprigh t support s woul d b e contributin g element s t o th e cultura l landscap e o f th e propose d boundar y expansio n o f th e Leadvill e Histori c Distric t fo r thei r contributio n t o ou r understandin g o f metal minin g processes

. Th e tw o smal l meta l structure s woul d b e noncontributing

. I t i s our determinatio n tha t the propose d sit e improvemen t projec t wil l hav e no effec t o n histori c properties

. Garibald i Workings (SLK80S

1 - H e fin d tha t thi s propert y i s no t 

### individuall y eligible , i s no t withi n th e existin g Leadvill e Histori c Distric t an d woul d no t contribut e t o th e distric t expansion

. Again
, th e nature o f th e sit e improvement s i s suc h tha t there wil l b e n o effec t o n historic properties

.July

27 , 1995 FINA L * EE/CA Garibaldi Mine Site * Appendices



### APPENDI X B HEC- 1 MODE L

H:\664\EECA\GARIBALD.FN

L 07/27/9 5 4:01p m WP51/cm c

### SURFAC E WATE R SYSTE M DESIG N METHODOLOGIE S AN D ASSUMPTION S HYDROLOGI C MODELIN G Hydrologi c modelin g wa s performe d t o determin e th e pea k runof f flow s fo r desig n o f diversion channel s aroun d th e wast e roc k pile

. HEC- 1 Floo d Hydrograp h Compute r Mode l Runof f calculation s fo r al l alternative s wer e performe d utilizin g th e HEC- 1 Floo d Hydrograp h Compute r Mode l develope d b y U.S

. Arm y Corp s o f Engineers (1991)

. HEC- 1 i s a hydrologi c and hydrauli c calculatio n mode l designe d fo r us e o n P C compute r systems

. The mode l i s designe d t o simulat e th e surfac e runof f respons e o f a watershe d t o precipitatio n b y representin g th e basi n a s a n interconnecte d syste m o f hydrologi c an d hydrauli c components

. Th e resul t o f th e modelin g proces s i s th e computatio n o f streamflo w hydrograph s a t desire d location s i n th e rive r basin

. A hydrograp h i s simpl y a plo t o f flo w pea k flo w rate s a s a functio n o f tim e at a poin t i n th e drainag e basin

. HEC- 1 calculate s pea k flo w rate s an d runof f volume s vi a a numerical modelin g techniqu e based o n use r input s o f a desig n stor m event , (i.e.
, precipitatio n frequency dat a an d selectio n o f rainfal l distribution)

. Hydrograph s ar e develope d o n a subwatershe d basi s wit h th e inpu t o f area , la g time , an d precipitatio n los s (i.e.
, SC S Curve Numbe r whic h relate s drainag e t o soi l type , soi l cover , lan d use , an d anteceden t moistur e conditions)

. Routin g o f hydrograph s i s accomplishe d b y th e kinematic wav e metho d fo r overlan d flo w an d th e Muskingu m metho d fo r collecto r channels

. Input s t o th e mode l include : Precipitatio n Informatio n Precipitatio n Losses Hydrograp h Respons e Shap e L a g Tim e Routin g Parameter s Inpu t value s use d i n thi s model ar e explaine d belo w and ar e show n i n the HEC- 1 Inpu t include d i n Appendi x B- l (Alternative s A
, B
, an d C ) an d Appendi x B- 2 (Alternativ e D)

. 

### Precipitatio n Informatio n T h e precipitatio n informatio n neede d include s th e amoun t o f precipitatio n an d stor m distributio n an d duration

. T h e Wor k Are a Management Pla n (USDC
, 1994 ) specifie s that remedia l alternative s utilizin g diversio n channel s and/o r reconstructe d strea m channel s locate d outsid e o f th e 500-yea r floodplai n o f Californi a Gulc h mus t hav e sufficien t capacit y t o conve y th e 100-year , 24-hou r an d 2-hou r stor m events

. Base d o n th e NOA A Atla s I I
- Precipitatio n Frequenc y Atla s o f th e Wester n Unite d States
, Volum e m , Colorad o (Ma y - October)
, th e precipitatio n amoun t use d fo r th e Garibald i Mine Site is : 100-year

, 24-hou r stor m even t 2. 4 inche sT h e

SC S determine d tha t th e relationshi p betwee n la g tim e an d th e tim e o f concentratio n ca n be calculate d usin g th e equation : t L = 0. 6 t

c where , t

L i s th e la g i n hour s t

c i s th e tim e o f concentratio n i n hour s 

### Routin g Parameters Subbasi n outflo w ma y b e obtaine d utilizin g overlan d flo w planes , collecto r channel s an d a mai n channel

. Tw o routin g method s wer e use d t o rout e rainfal l runof f throug h th e watershed

. Th e Muskingu m routin g techniqu e wa s use d t o rout e overlan d flow
, an d th e kinemati c wav e metho d
wa s use d t o rout e latera l inflow s and upstrea m hydrograph s throug h channels

. 

### T h e Muskingu m routin g techniqu e relie s o n th e SC S Uplan d Method

. Th e uplan d metho d calculate s th e tim e o f concentratio n fo r a watershe d o r watershe d segmen t b y summin g th e flo w tim e fo r overlan d flo w an d channe l flow

. Flo w tim e i s a functio n o f lan d use , lengt h o f travel , 

### an d slope

. T h e kinemati c wav e metho d was use d t o rout e latera l inflow s an d upstrea m hydrograph s throug h channels

. Th e kinematic wav e parameter s use d t o determin e th e tota l hydrauli c tim e ar e base d o n a n approximatio n o f Manning' s equation

. Thi s routin g metho d use s physica l 

### channel propertie s an d th e upstrea m inflo w hydrograph

. Inpu t dat a consist s o f channel length , channe l be d slope , Mannin g roughness coefficient
, an d channe l cross-sectio n information

. CHANNE L MODE L T h e surfac e wate r diversion s wer e sized usin g Manning' s Equatio n fo r ope n channel flow

. Th e 

### slop e o f the ditche s wer e determine d fro m a 1 " = 1000 compute r generate d map

. Q = 1.48 6 AR

% S "
n 

### where, Q = pea k discharg e fro m a stor m even t (cfs )
n = Manning' s roughness coefficien t A = cros s sectiona l are a o f flo w (ft 2 

### ) R = hydraulic radiu s (ft ) S = channe l slop e (ft/ft ) A Manning' s roughness coefficien t o f 0.03 5 and 0.01 5 wa s use d fo r gras s line d and concret e channel s respectivel y (Haan
, e t al. , 1994)

. Accordin g t o Abt (1988)
, a Manning' s n fo r ripra p i n stee p channel s ca n b e approximate d by :
i0.15

9 

### n = 0.045 6 (D 5 0 

### S) a 

### where, n = Manning' s roughness coefficien t D 5 0 

### = averag e ripra p diamete r (inches ) S = channe l slop e (ft/ft ) 

### A Manning' s "n " o f 0.041 wa s calculate d fo r th e ripra p line d channel

.July

27, 1995 FINAL * EE/CA Garibaldi Mine Site * Appendices



### APPENDI X B- 1 HEC- 1 MODE L ALTERNATIVES A
, B
, AN D C

H:\664\EECA\GARIBALD.FN

L 07/27/9 5 4:01pm WP51/cm cHEC 1 S/N : 013430066 5 HMVersion :

6.3 3 Data File : c:\hecpack\resurrec\garibald.hc 1

************************************ * \^_^/ *
* FLOO D HYDROGRAPH

PACKAG E (HEC-1 ) * * HA

Y 199 1 * * VERSIO

N 4.0.1 E * * *
* RU N DAT E 05/11/199 5 TIM E 11:35:59 * * * **************************************** * ************************************** * U.S

. ARM Y CORP S O F ENGINEER S HYDROLOGI C ENGINEERIN G CENTE R 6 0 9 SECON D STREE T DAVIS
, CALIFORNIA

9561 6 (916 ) 756-110 4

************************************** *

X X XXXXXX X XXXX X X X X X X X X X X XXXXXX X XXX X X X X X X X X X X X X X XXXXXX X XXXX X XXXX X X X X X X X X X X X

Ful l Microcompute r Implementatio n b y Haesta d Methods
, Inc

.

3 7 Brooksid e Roa d * Waterbury
, Connecticu t 0670 8 * (203 ) 755-166 6

THI S PROGRA M REPLACE S AL L PREVIOUS VERSION S O F HEC- 1 KNOUN AS HEC 1 (JA N 73)
, HEC1GS
, HEC1DB
, AN D HEC1KW

. T H E DEFINITION S O F VARIABLE S -RTIHP

- AN D -RTIOR

- HAV E CHANGE D FRO M THOS E USE D WIT H TH E 1973-STYL E INPU T STRUCTURE

. T H E DEFINITIO N O F -AMSKK

- O N RM-CAR D WAS CHANGE D WIT H REVISION S DATE D 2 8 SE P 81

. THI S I S TH E FORTRAN? ? VERSIO N N E W OPTIONS : DAMBREA K OUTFLO W SUBMERGENC E
, SINGL E EVEN T DAMAG E CALCULATION
, DSS:WRIT E STAG E FREQUENCY
, DSS:REA D TIM E SERIE S AT DESIRE D CALCULATIO N INTERVA L LOS S RATE:GREE N AN D AMP T INFILTRATIO N KINEMATI C WAVE : NE W FINIT E DIFFERENC E ALGORITHMHEC- 1 INPU T PAG E 2 LIN E ID.......1.......2.......3.......4.......5.......6.......7.......8.......9......1 0

3 8 K K ditch4Alpin e Overlan d Flo w Route d t o Ditc h 4 3 9 K M rout e alpin e flo w throug h wood s t o ditc h # 4 4 0 R

M
- 1 0.11 9 0.33 9 4 1 K K 4woodsDitc h 4 Wood s Subwatershe d Generatio n 4 2 K M runof f fro m wood s tha t drain s t o ditc h # 4 4 3 B

A 0.071 7 4 4 L S 0 6 0 4 5 U D 0.14 5 4 6 K K 3and4Uppe r Ditc h 4 Flo w 4 7 K M combin e ditc h 3 flo w wit h inflow s fro m ditc h 4 subwatershed s 4 8 H

C 3 4 9 K K 4at2Rout e Uppe r Ditc h 4 Hydrograp h t o junctio n wit h Ditc h 2 5 0 K M rout e flo w throug h uppe r ditc h 4 t o ditc h 2 inflo w 5 1 R K

22 0 0.1 6 0.01 5 TRA

P 2 2 52 K K IwoodsDitc h 1 Wood s Subwatershe d Generatio n 5 3 K M runof f fro m wood s tha t drain s t o ditc h # 1 5 4 B

A 0.007 3 5 5 L S 0 6 0 5 6 U D 0.07 2 5 7 K K loutflRout e Ditc h 1 flo w t o Ditc h 2 inflo w 5 8 K M rout e ditc h 1 flo w t o ditc h 2 5 9 R

K 44 1 0.0 2 0.03 5 TRA

P 2 2 6 0 K K 2alpinDitc h 2 Alpin e Subwatershe d Generatio n 6 1 K M runof f fro m alpin e subwatershe d tha t drain s t o ditc h 2 6 2 B

A 0.061 1 6 3 L S 0 80 6 4 U

D 0.12 6 6 5 K K ditch2Alpin e Overlan d Flo w Route d t o Ditc h # 2 6 6 K M rout e alpin e flo w throug h wood s t o ditc h # 2 6 7 R M
- 1 0.1 3 0.34 7 68 K K 2woodsDitc h 2 Wood s Subwatershe d Generatio n 6 9 K M runof f fro m wood s tha t drain s t o ditc h 2 7 0 B

A 0.047 3 7 1 L S 0 6 0 7 2 U

O 0.07 7 7 3 K K 1and2Combin e Ditc h 1 flo w wit h Ditc h 2 subwatershe d inflow s 7 4 K M combin e flo w fro m ditc h 1 wit h ditc h 2 inflow s 7 5 H C 3 7 6 K K 2at4Rout e Combine d Ditc h 1 an d Ditc h 2 Flo w t o Ditc h 4 7 7 K M rout e flow s fro m ditc h 2 t o ditc h 4 junctio n 7 8 R

K 225 0.0 8 0.01 5 TRA

P 2 2INPU T N O

. 7

1 8 SCHEMATIC

DIAGRA M O F STREA M NETWOR K ( V ) ROUTIN G (—> )

DIVERSIO N O R PUM P FLO W ( . ) CONNECTO R <<--- ) RETUR N O F DIVERTE D O R PUMPE D FLO W 3alpi n V V ditch 3

21 3wood

s

2 6

2 9 DITCH3

. V V 3outf l

3 2

3 7 4alpi n

V V ditch 4

4 0 4wood

s

4 5

4 8 3and4

. V V 4at 2

5 1

5 6 1wood

s V V loutf l

5 9

6 4 2alpi n V

V ditch 2

6 7 2 wood s

7 2 1and2

.

V V 2at 4

7 8 4and2

. VRUNOF F SUMMAR Y FLO W I N CUBI C FEE T PE R SECON D TIM E I N HOURS
, ARE A I N SQUAR E MILE S OPERATIO N HYDROGRAP H A T ROUTE D T O HYDROGRAP H A T
2 COMBINE D A T ROUTE D T O HYDROGRAP H A T ROUTE D T O HYDROGRAP H A T

3 COMBINE D A T ROUTE D T O HYDROGRAPH A T ROUTE D T O HYDROGRAP H A T ROUTE D T O HYDROGRAPH A T
3 COMBINE D A T ROUTE D T O
2 COMBINE D A T ROUTE D T O HYDROGRAP H A T
2 COMBINE D A T STATIO N 3atpi n ditch 3

. 3wood s DITCH 3 3outf l 4alpi n ditch 4
4 wood s 3and 4
4at 2 1 wood s loutf l 2alpi n ditch 2 2wood s 1and 2 2at 4 4and 2 4outf l Iouer 4 CalGu l PEA

< FLO W
12

. 11

. 1

. 12

. 11

. 29

. 26

. 2

. 39

. 39

. 0

. 0

. 23

. 21

. 1

. 23

. 23

. 62

. 62. 0. 62

. TIM E O F PEA K
12.0 0
12.50
12.5 0
12.5 0
12.5 0
12.0 0 12.5 0 12.5 0 12.5 0
12.5 0 12.50 12.50 12.0 0 12.5 0 12.5 0 12.5 0 12.50 12.5 0 12.5 0 12.50 12.50 AVERAG E 6

- HOU R
3

. 3

. 0

. 3

. 3

. 6

. 6

. 1

. 11

. 11

. 0

. 0

. 5

. 5

. 1

. 6

. 6

. 17

. 16

. 0

. 16

. FLO W FO R MAXIMU M 24-HOU R

1

. 1

. 0

. 1

. 1

. 2

. 2

. 0

. 4

. 4

. 0

. 0

. 2

. 2

. 0

. 2

. 2

. 6

. 6

. 0

. 6

. PERIO D 72-HOU R
1

. 1

. 0

. 1

. 1

. 2

. 2

. 0

. 4

. 4

. 0

. 0

. 2

. 2

. 0

. 2

. 2

. 6

. 6

. 0

. 6

. BASI N ARE A
0.0 3
0.0 3
0.0 3
0.0 6
0.0 6
0.0 8
0.0 8
0.0 7
0.2 1 0.2 1
0.0 1
0.0 1
0.0 6
0.0 6 0.0 5 0.1 2 0.1 2 0.3 2 0.3 2
0.0 1 0.3 3 MAXIMU M

TIM E O F STAG E MA X STAG EJuly

27, 1995 FINAL * EE/CA Garibaldi Mine Site * Appendices



### APPENDI X B- 2 HEC- 1 MODE L ALTERNATIV E D

H:\664\EECA\GAR1BALD.FN

L 07/27/9 5 4:01p m WP51/cm cHEC 1 S/N : 013430066 5 HMVersion :

6.3 3 Dat a File : garaltd.h d

************************************ *

* FLOO D HYDROGRAP

H PACKAG E (HEC-1) * * MA

Y 199 1 * * VERSIO N

4.0.I E * * * * RU N DAT E 05/11/199 5 TIM E 74:33:3 4 * ************************************** * * *
* U.S

. ARM Y CORP S O F ENGINEER S

* HYDROLOGI C

ENGINEERIN

G CENTE R * 6 0 9 SECON D STREE T * DAVIS
, CALIFORNI

A 9561 6 * (916 ) 756-110 4 *

**************************************** * ************************************** *

X X X X X X 

### xxxxxxx X X X X X X 

### xxxxxxx X X xxx x X X 

### xxxxxx x xxxx x X X X X X X X xxxxx xxxxx X

X X X X X X X X X

Ful l Microcompute r Implementatio n b y Haesta d Methods
, Inc

.

3 7 Brooksid e Roa d * Waterbury
, Connecticu t 0670 8 * (203 ) 755-166 6

THI S PROGRA M REPLACE S AL L PREVIOUS VERSION S O F HEC- 1 KNOW N AS HEC 1 (JA N 73)
, HEC1GS
, HEC1DB
, AN D HEC1KU

. T H E DEFINITION S O F VARIABLE S -RTIMP

- AN D -RTIOR

- HAV E CHANGE D FRO M THOS E USE D WIT H TH E 1973-STYL E INPU T STRUCTURE

. T H E DEFINITIO N O F -AMSKK

- O N RM-CAR D WAS CHANGE D WIT H REVISION S DATE D 2 8 SE P 81

. THI S I S TH E FORTRAN7 7 VERSIO N N E W OPTIONS : DAMBREA K OUTFLO W SUBMERGENC E
, SINGL E EVEN T DAMAG E CALCULATION
, DSS:WRIT E STAG E FREQUENCY
, DSS:REA D TIM E SERIE S AT DESIRE D CALCULATIO N INTERVA L LOS S RATE:GREE N AN D AMP T INFILTRATIO N KINEMATI C WAVE : NE W FINITE DIFFERENC E ALGORITH MHEC- 1 INPU T PAG E 2 LIN E ID.......1.......2.......3.......4.......5.......6.......7.......8.......9......1 0

3 8 K K upper2Alpin e Overlan d Flo w Route d t o Uppe r Ditc h 2 3 9 K M rout e alpin e flo w throug h wood s t o uppe r ditc h # 2 4 0 R

M
- 1 0.119 0.33 9 4 1 K K 2woodsUppe r Ditc h 2 Wood s Subwatershe d Generatio n 4 2 K M runof f fro m wood s tha t drain s t o uppe r ditc h # 2 4 3 B

A 0.088 3 4 4 L S 0 6 0 4 5 U

D 0.14 5
4 6 K

K UPPER2Uppe r Ditc h 2 Flo w 4 7 K M combin e runof f fro m alpin e an d wood s subuatershed s 4 8 H

C 2 4 9 K K 2at1Rout e Uppe r Ditc h 2 Hydrograp h t o junctio n wit h Ditc h 1 5 0 K M rout e flo w throug h uppe r ditc h 2 t o ditc h 1 inflo w 5 1 RK

33 0 0.1 9 0.03 5 TRA

P 2 2 5 2 K K 2at1Combin e Ditc h 1 hydrograp h wit h Uppe r Ditc h 2 hydrograp h 5 3 K M comine d hydrograp h fo r ditc h 1 an d uppe r ditc h 2 5 4 H C 2 5 5 K K calgulRout e combine d hydrograp h throug h lowe r ditc h 2 t o Ca l Gulc h 5 6 K M Combine d hydrograp h route d t o Ca l Gulc h 5 7 R

K 40 0 0.1 3 0.03 5 TRA

P 2 2 5 8 K K 2lowerLowe r Ditc h 1 Wood s Subwatershe d Generatio n 59 K M runof f fro m wood s tha t drain s t o lowe r ditc h # 2 6 0 B A 0.012 5 6 1 L S 0 6 0 6 2 U

D 0.057 0 6 3 K K calgulRout e Lowe r Ditc h 2 flo w t o Ca l Gulc h 6 4 K M rout e lowe r ditc h 2 flo w t o Ca l Gulc h 6 5 R

K 40 0 0.1 3 0.03 5 TRA

P 2 2
6 6 K

K CalGu l 6 7 K M combine d flo w i n Californi a Gulc h belo w Garibald i Pil e 6 8 H

C 2 6 9 Z ZRUNOF F SUMMAR Y FLO W I N CUBI C FEE T PE R SECON D TIM E I N HOURS
, ARE A I N SQUAR E MILE S OPERATIO N HYDROGRAPH A T ROUTED T O HYDROGRAP H A T
2 COMBINE D A T ROUTE D T O HYDROGRAPH A T ROUTE D T O HYDROGRAP H A T
2 COMBINE D A T ROUTE D T O
2 COMBINE D A T ROUTE D T O HYDROGRAP H A T ROUTE D T O
2 COMBINED A T STATIO N lalpi n ditc M 2wood s DITCH 1 1at 2 2alpi n upper 2 2wood s UPPER 2
2at1 2at1 calgu l
2 lowe r calgu l CalGu l PEA

K FLO W
29

. 26

. 2

. 28

. 28

. 33

. 29

. 3

. 32

. 32

. 60

. 60

. 0

. 0

. 60

. TIM E O F PEA K
12.0 0 12.5 0 12.5 0 12.50 12.50 12.0 0 12.5 0 12.5 0 12.5 0 12.5 0 12.5 0 12.5 0 12.50 12.50 12.50 AVERAG E 6

- HOU R
7

. 7

. 1

. 7

. 7

. 7

. 7

. 1

. 9

. 9

. 16

. 16

. 0

. 0

. 16

. FLO W FO R MAXIMU M 24

- HOU R
2

. 2

. 0

. 3

. 3

. 3

. 3

. 0

. 3

. 3

. 6

. 6

. 0

. 0

. 6

. PERIO D 72

- HOU R
2

. 2

. 0

. 3

. 3

. 3

. 3

. 0

. 3

. 3

. 6

. 6

. 0

. 0

. 6

. BASI N MAXIMU M TIM E O F ARE A STAG E MA X STAG E
0.0 8
0.0 8
0.0 6
0.1 3
0.1 3
0.0 9
0.0 9
0.0 9
0.1 7
0.1 7
0.3 1
0.31
0.0 1
0.0 1
0.3 2July

27, 1995 FINAL * EE/CA Ganbaldi Mine Site * Appendices



### APPENDI X C HEL P MODE L

H:\664\EECA\GARIBAID.FN

L 07/27/9 5 4:01p m WP51/cm cJune

2, 1995 HELP Model * Appendix C * Page C-l Thi s appendi x discusse s infiltratio n rate s fo r th e Garibald i wast e roc k pil e usin g th e U.S

. EP A Hydrologi c Evaluatio n o f Landfil l Performanc e (HELP ) model

. Infiltratio n wa s estimate d fo r bar e tailing s an d wa s the n compare d t o infiltratio n rate s fo r variou s cove r systems

. 

### C . I Cove r Scenario s T h e tailing s cove r scenario s analyze d ar e provide d below : Bar e tailing s Desig n 1 - Existin g weathere d ca p Desig n 2 - Simpl e cove r Existin g weathere d ca p consist s o f approximatel y 12-inche s of f weathere d wast e rock

. Th e simpl e cove r consist s o f a n 18-inc h thick laye r o f borrow soil

. 

### C . 2 HEL P Modellin g T h e U.S

. EP A HELP Mode l versio n 2 wa s use d t o predic t infiltratio n an d runof f fo r th e wast e roc k pile

. T h e infiltratio n modellin g wa s conducte d utilizin g HELP' s syntheti c weathe r generator

. Gran d Junction
, Colorado
, wa s seleae d fro m th e HELP Mode l climati c databas e o f citie s fo r climati c generation

. Gran d Junctio n wa s seleae d buse d o n it s clos e proximit y t o Leadvill e latitud e an d climati c conditions

. Tabl e C. I show s averag e monthl y temperatur e dat a fro m 1895 t o 196 0 an d average monthl y precipitatio n dat a fro m 190 5 t o 196 0 fo r Leadvill e (U.S

. Weathe r Bureau
, 1960 ) tha t was entere d i n th e HEL P Mode l t o increas e th e accurac y o f th e calculations

. I n addition , Tabl e C. 2 show s th e humidit y dat a fo r Leadville
, whic h was entere d t o increas e th e accurac y o f th e model

. TABLE C. 1 AVERAG E MONTHL Y TEMPERATUR E AN D PRECIPITATIO N A v g Tem p ( F ) A v g Preci p (in ) J A N 17. 9
1.3 2 F E B 19. 3
1.5 1 M A R 23. 2
1.7 1 A P R 32. 2
1.83 M A Y 42. 0
1.4 4 J U N 51. 4
1.1 3 J U L 56. 9
2.7 3 A U G 55. 6
2.1 1 S E P 49. 6
1.35 OC T 39. 4
1.1 1 N O V 26. 4
1.0 7 DE C 20. 3
1.1 7
TABL E C. 2 QUARTERL Y AVERAG E HUMIDIT Y I N LEADVILL E
% Humidit y 1 s t Quarte r 52. 3 2n

d Quarte r 52. 6 3r

d Quarte r 64. 3 4t

h Quarte r 47, 7 The inpu t parameter s use d o r climati c condition s were : 1 ) a latitud e o f 39.14 ; 2 ) a lea f are a inde x o f 1.6 0 fo r cover s wit h vegetatio n (th e maximu m supportabl e withou t irrigation) ; 3 ) a lea f
are a inde x o f 0.0 0 fo r cover s wit h n o vegetation ; 4 ) 2 0 year s o f weathe r generation ; 5 ) a n 18-inc h

H:\664\EECA\GARAPP. C 06/01/9 5 6:29a m WP51/cm cJuly

27 , 1995

__________ ______

FINA

L * EE/CA Garibaldi Mine Site * Appendices



### APPENDI X C- 1 HEL P MODE L OUTPU T GARIBALD I WEATHERE D CAP

H:\664\EECA\GARBALD.FN

L 07/27/9 5 4:01p m WP51/cm c*

* * * HYDROLOGI

C EVALUATIO N

O F LANDFIL L PERFORMANC E HEL P MODE L VERSIO N 3.0 3 (3 1 DECEMBE R 1994 } DEVELOPE D B Y ENVIRONMENTA

L LABORATOR Y USA E WATERWAY S EXPERIMEN T STATIO N F O R USEP A RIS K REDUCTIO N ENGINEERIN

G LABORATOR Y

PRECIPITATIO N

DAT A FILE : TEMPERATUR E DAT A FILE : SOLA R RADIATIO N DAT A FILE : EVAPOTRANSPIRATIO N

DATA : SOI L AN D DESIG N DAT A FILE : OUTPUT DAT A FILE : C:\HELP3\LEAD.D 4 7 C:\HELP3\GJLEAD.D1 3 C:\HELP3\GJLDO.Dl l C:\HELP3\GBEXIST.D1 0 C:\HELP3\GBEXIST.OU T TIME : 9:2 7 DATE :

5/31/199 5

TITLE : GARIBALD I

WEATHERE D CA P

NOTE : INITIA

L MOISTUR E CONTEN T O F TH E LAYER S AN D SNO W WATE R WER E COMPUTE D A S NEARL Y STEADY-STAT

E VALUE S B Y TH E PROGRAM

. LAYE R 1 TYP E 1 - VERTICA L PERCOLATIO N

LAYE R MATERIA L TEXTUR E NUMBE R 1 0 THICKNES S POROSIT Y FIEL D CAPACIT Y WILTIN G POIN T INITIAL SOI L WATE R CONTEN T EFFECTIV E SAT

. HYD

. COND

. 12.0 0

INCHE S 0.398 0 VOL/VO L 0.244 0 VOL/VO L 0.136 0 VOL/VO L ?????????? ? VOL/VO L 0.119999997000E-0 3

CM/SE C

GENERA L DESIG N AN D EVAPORATIV

E ZON E DAT A NOTE : SC S RUNOF F CURV E NUMBE R WA S COMPUTE D FROM A USER

- SPECIFIE D CURV E NUMBE R O F 86.0 , A SURFAC E SLOP E O F 31. % AN D A SLOP E LENGT H O F 100

. FEET

. S C S RUNOF F CURV E NUMBE R FRACTIO N OF

. ARE A ALLOWIN G RUNOF F ARE A PROJECTE D O N HORIZONTA L PLAN E EVAPORATIV E ZON E DEPT H INITIA L WATE R I N EVAPORATIV

E ZON E UPPE R LIMI T O F EVAPORATIV

E STORAGE LOWE R LIMI T OF EVAPORATIV

E STORAGE INITIA L SNO W WATE R INITIA L WATE R I N LAYER MATERIAL S TOTA L INITIA L WATE R TOTA L SUBSURFAC E

INFLO W =

=

=

= =

=

=

= = ?• > =•>•> 87.8 0 100. 0 1.60 0 12. 0 2.62 7 4.77 6 1.63 2 0.00 0 •> •> •> •} •) •>•> •> •> PERCEN T ACRE S INCHE S INCHE S INCHE S INCHE S INCHE S INCHE S 0.0 0 INCHES/YEA RPERCOLATION/LEAKAGE THROUG H LAYE R 1 TOTAL S STD

. DEVIATION

S 0.000 0 0.411 2 0.000 0 0.457 5 0.000 0 0.296 4 0.000 0 0.455 0 0.016 7 0.090 8 0.074 5 0.1869 0.097

2 0.075 9 0.217 1 0.307 4 0.241 6 0.012 4 0.344 9 0.028 5 0.183 1 0.000 7 0.363 8 0.003 2

PRECIPITATIO N RUNOF F EVAPOTRANSPIRATIO N PERCOLATION/LEAKAG E

THROUG H 17

. 2

. 13

. 1

. INCHE S .6 9 ( .80 4 ( .43 7 ( .4258 3 ( C U

.

FEE T 2 1

. 2

. 0

. .573 ) 3625 ) 2036 ) 64216 ) 102726

. 16283

. 78044

. 8281

. . 1 .3 1 .84 .22 3 PERCEN

T 100

. 15

. 75

. 8

. .00 .85 1 .974 .0614 6 CHANG E I N WATE R STORAGE 116.7 3 0.11 4FINA L WATER STORAG E A T EN D O F YEA R 2 0 LAYE R '(INCHES

) (VOL/VOL

) 1 ?????????? ?

???????? ? SNO W WATE R 0.00 0July

27, 1995 FINAL * EE/CA Garibaldi Mine Site * Appendices



### APPENDI X C- 2 HEL P MODE L OUTPU T GARIBALD I SIMPL E COVER

H:\664\EECA\GARIBALD.FN

L 07/27/9 5 4:01p m WP51/cm c*

* * *

* * * * * * HYDROLOGI

C EVALUATIO N

O F LANDFIL L PERFORMANC E HEL P MODE L VERSIO N 3.0 3 (3 1 DECEMBER 1994 ) DEVELOPED B Y ENVIRONMENTA

L LABORATOR Y USA E WATERWAY S EXPERIMEN T STATIO N F O R USEP A RIS K REDUCTIO N ENGINEERIN

G LABORATOR Y 

### *

* * *

PRECIPITATIO N

DAT A FILE : TEMPERATUR E DAT A FILE : SOLA R RADIATIO N DAT A FILE : EVAPOTRANSPIRATIO N

DATA : SOI L AN D DESIGN DAT A FILE : OUTPU T DAT A FILE : C:\HELP3\LEAD.D 4 7 C : \HELP3\GJLEAD.D1 3 C:\HELP3\GJLEAD.D1 1 C:\HELP3\GBCOVER.D1 0 C : \HELP 3 \GBCOVER

. OU T TIME : 9 : 9 DATE :

5/31/199 5

TITLE : GARIBALD I

SIMPL E COVE R

NOTE : INITIA

L MOISTUR E CONTEN T O F TH E LAYER S AN D SNO W WATE R WER E COMPUTE D A S NEARL Y STEADY-STAT

E VALUE S B Y TH E PROGRAM

. LAYE R TYP E 1 - VERTICA L PERCOLATIO N

LAYER MATERIA L TEXTUR E NUMBE R 6 THICKNES

S =

18.0 0

INCHE S POROSIT Y =

0.453 0

VOL/VO L FIEL D CAPACIT

Y = 0.190 0

VOL/VO L WILTIN G POIN T =

0.085 0

VOL/VO L INITIA L SOI L WATE R CONTEN T =??????????? ?

VOL/VO L EFFECTIV E SAT

. HYD

. COND

. = 0.720000011000E-0 3

CM/SE C NOTE : SATURATE D

HYDRAULI C CONDUCTIVIT

Y I S MULTIPLIE D

B Y 2 , F O R ROO T CHANNEL S I N TO P HAL F OF EVAPORATIV

E ZONE

. 4

9

GENERA L DESIGN AN D EVAPORATIV

E ZON E DAT A NOTE : SC S RUNOF F CURV E NUMBE R WA S COMPUTE D FRO M A USER

- SPECIFIE D CURV E NUMBE R O F 80.0 , A SURFAC E SLOP E O F 29. % AN D A SLOP E LENGT H O F 120

. FEET

. S C S RUNOF F CURV E NUMBE R FRACTION O F ARE A ALLOWIN G RUNOF F ARE A PROJECTE D O N HORIZONTA L PLAN E EVAPORATIV E ZON E DEPT H INITIA L WATE R I N EVAPORATIV

E ZON E UPPE R LIMI T OF EVAPORATIV

E STORAGE LOWE R LIMI T O F EVAPORATIV

E STORAG E INITIA L SNO W WATE R INITIA L WATE R I N LAYER MATERIAL S TOTAL INITIAL WATE R TOTA L SUBSURFAC E

INFLO W 82.5 0 100. 0 1.60 0 18. 0 2.84 9 8.15 4 1.53 0 0.00 0 =?????????? ? =?????????? ? 0.0 0 PERCEN

T ACRE S INCHE S INCHE S INCHE S INCHE S INCHE S INCHE S INCHE S INCHES/YEA RSTD

.

DEVIATION

S PERCOLA T I O N / LEAKAG E TOTAL S STD

. DEVIATION

S 0

.

1

. THROUG H 0

. 0

. 0

. 0

. 25 1 08 0 LAYE R 000 0 253 3 000 0 524 3 0.15 0 0.98 2 1 0.000 0 0.194 5 0.000 0 0.306 5 0 0

0 0 0 0 .38 9 .92 0

.000 0 .041 5 .000 0 .107 5 0.54 3 0.52 2

0.000 6 0.042 2 0.001 6 0.156 1 0..89 2 0.27 8

0.101 0 0.017 4 0.264 4 0.077 5 0.91 4 0.31 0

0.118 5 0.000 3 0.320 6 0.001 4

AVERAG E ANNUA L TOTAL S & PRECIPITATIO N RUNOF F EVAPOTRANSPIRATIO N PERCOLATION/LEAKAG E THROUG

H (STD

.

17

. 2

. 14

. 0

. DEVIATIONS ) INCHE S 6 9 ( 29 1 ( 61 3 ( 7692 7 ( F O R YEAR S 1 THROUG

H C U

. FEE T 2 1

. 2

. 0

. .573) 2137 ) 3894 ) 68466 ) 10272 6 1330 6 8487 1 446 7 . 1 .5 0 .0 7 .93 6 2 0 PERCEN T 100.0 0 12.95 3 82.61 9 4.3493 7 CHANG E I N WATE R STORAG E 80.6 1 0.07 8FINA L WATE R STORAG E A T EN D OF YEA R 2 0 LAYER (INCHES

) (VOL/VOL

) 1 ?????????? ?

???????? ? SNO W WATE R 0.00 0July

27, 1995 FINAL * EE/CA Garibaldi Mine Site * Appendices



### APPENDI X D 

### SOI L LOS S CALCULATION S

H:\664\EECA\GARBALD.FN

L 07/27/9 5 4:01p m WP51/cm cANNUA L SOI L LOS S CALCULATION

S METHODOLOGIE S

AN D ASSUMPTION

S

1. 0 SEDCA D + SEDIMENTATIO

N COMPUTER MODE L Sedimen t yiel d wa s determine d for a singl e stor m even t (10-yea r 24-hour ) and converted t o an annua l yield

. Th e calculation s t o determin e th e stor m sedimen t yiel d wer e performe d b y th e us e o f th e SEDCA D + Compute r Mode l develope d b y Civil Softwar e Design

. T h e SEDCAD-t

- mode l determine s soi l los s usin g th e Revised Universa l Soi l Los s Equatio n (RUSLE ) wit h th e following inpu t parameters : Y = 95*(V*Q

p )°- 56 *K*LS*CP
Where : Y = Sedimen t yiel d (tons ) V = Runof f volum e (acre-feet ) Q p = Pea k discharg e (cfs ) K = Soi l credibilit y facto r L S = Representativ e length-slop e facto r C P = Contro l practic e facto r T h e length-slop e facto r fo r th e RUSL E subroutin e i s a s follows : 

### LS = —^— * (slope factor) 72. 6 Where : X = Representativ e slop e lengt h (ft )
m = 0. 6 fo r slop e > 10 % m = 0. 5 fo r 4 % < slop e < 10 % m = 0. 4 fo r slop e = 4 %
m = 0. 3 fo r slop e < 4 % The slop e facto r i s a piecewis e linea r relationshi p wit h the slop e breakpoin t at 8 % a s show n on Figur e 5.5 , Slop e Facto r fo r th e RUSLE
, containe d i n th e SEDCA D + Users Manual.

. Input s fo r th e sedimentolog y portio n o f th e SEDCAD + routine are : Runof f volum e Pea k discharg e Soi l erodibilit y facto r Representativ e slop e lengt h Averag e slop e Contro l practic e facto r Sedimen t specifi c weight

H:\6M\EECA\GARIBALD.AP

D 06/01/9 5 7:00a m WP51/cm c

### 1. 5

Contro l Practic e Factor
, C P T h e contro l practic e facto r i s define d as th e rati o o f sedimen t los s fro m a n are a wit h a give n cove r an d conservatio n practic e t o tha t o f a fiel d in continuou s fallow

. Th e followin g value s wer e utilized : 

### Cove r Conditio n Existin g Cemente d Simple Cove r N o appreciabl e canopy , 20 % grass C P 0. 3 0.2 0 

### 1. 6 Annua l sediment yield , V
, innua l 

### Sedimen t yield s calculate d b y SEDCAD + fo r singl e stor m event s ca n b e converte d t o annua l yield s b y th e following equation :

annual D

_ annua l R storm Where : V
,

- D annua l •annua l F o r a SC S Typ e H Storm : Annua l

sedimen t yiel d (tons/yr ) Singl e stor m rainfal l facto r Singl e stor m rainfal l facto r Settlemen t yiel d fo r 10-yr , 24-h r stor m even t (tons )

R annual = 27*(P 2 , 6 ) 2. 2 Where : 2-yr

, 6-h r precipitatio n i n inche s = 0. 8 inche s R stor m 1 9 .2 5 £j0.467 2 ,2. 2

Where : 10,2

4 D 10-yr

, 24-h r precipitatio n i n inche s = 1. 6 inche s Stor m Duratio n = 2 4 hour s 2. 0 RESULT S 

### Soi l los s analyse s wer e conducte d fo r alternative s A throug h C

. Th e following ar e th e results : Alternativ e A & B Alternativ e C 6. 1

tons/acre/yea r 1. 0 tons/acre/yea r

H:\664\EECA\GARBALD.AP

D 06/01/9 5 7:00a m WP51/cm cJuly

27, 1995 FINAL * EE/CA Garibaldi Mine Site '• Appendices



### APPENDI X D- 1 SEDCAD + PRINTOUT S

H:\664\EECA\GARBALD.FN

L 07/27/9 5 4:01pm WP51/cm cCIVI L SOFTWAR E DESIG N SEDCAD + Versio n 3

GARABALDI: SOI L LOS S FO R EXISTIN G CONDITION S



### b y
Name : TE L 

### Compan y Name : ACZ
, INC

. 

### Fil e Name : D:\TOM\RESURECT\GBASI

S Date : 03-30-199 5CIVI L SOFTWAR E DESIG N 

### SEDCAD + Versio n 3

GARABALDI : REGRADE D AN D SIMPL E SURFAC E



### b y
Name : TEL Company Name : ACZ
, INC

. Fil e Name : D:\TCM\RESURECT\GBREGR 

### Date : 03-16-199 5July

27 , 1995
_____ FINA L * EE/CA Garibaldi Mine Site * Appendices



### APPENDI X D- 2 

### SOI L ERODIBILIT Y NOMOGRAP H

H:\664\EECA\GARBALD.FN

L 07/27/9 5 4:01p m WP51/cm c

### v o

u 

# 4

V ) X l u 

### V J

\

ONV S 3N U XH3 A « • U S JJOOWJ d • H C ~4 O

u u i U C M ( 0

— i- ( U S • H O W O J O 60- H M C O t u < H C O 

# I

U 9 O

a C O V i M

7.1-29 0July

27, 1995
____________

FINAL

* EE/CA Garibaldi Mine Site * Appendices



### APPENDI X E STABILIT Y ANALYSI S

H:\6fr4\EECA\GARBALD.FN

L 07/27/9 5 4:01p m WP51/cm c

### STABILIT Y ANALYSI S 

### GARIBALD I MINE SITE ALTERNATIV E A THROUG H C I n Alternative s A an d B th e wast e roc k pil e wil l remai n i n thi s curren t configuration

. Th e wast e roc k pil e i s approximatel y 3 0 fee t hig h wit h 1.4H:1 V slopes

. Th e wast e roc k pil e ha s been i n existences for mor e than 50 year s wit h n o indication s o f instabilit y or surfac e failure

. Give n this observation , i t ca n b e conclude d tha t th e wast e roc k pil e i n it s curren t configuratio n ha s a Facto r o f Safet y o f at leas t 1. 0 or greater

. However
, given the curren t informatio n on the wast e roc k materia l it i s difficult t o determin e th e actua l Facto r o f Safet y fo r th e curren t configuration

. I f ther e wa s a failur e du e t o earthquakes , and/o r heav y precipitatio n events , ther e woul d be mos t likel y a minor shallo w surfac e failure

. Give n th e configuratio n o f th e wast e roc k pile , thi s typ e o f failur e woul d hav e littl e o r n o effec t o n th e propose d acces s roa d and/o r th e propose d drainag e diversions

. I n Alternativ e C
, th e slope s wil l b e regrade d t o 3H:1V

. Wast e roc k materia l propertie s fo r th e stabilit y analysi s o f th e regrade d slope s wer e determine d throug h bac k analysis o f th e existin g conditions

. Th e bac k analysis wa s conducte d usin g XSTAB L compute r software

. Th e Bisho p met 1

- > d wa s selecte d withi n XSTAB L fo r computin g th e Facto r o f Safety

. Th e bac k analysi s wa s conducte d o n the highes t an d steepes t cross-sectio n a s show n o n the XSTAB L compute r printouts , assumin g draine d conditions , a cohesio n equa l t o 0, an d a Facto r o f Safet y o f 1.0

. Usin g this approach , a maximum interna l frictio n angl e o f 3 6 wa s determined

. T h e materia l propertie s determine d in th e bac k analysi s wer e the n use d t o determin e th e Facto r o f Safet y fo r th e regrade d slopes

. Wit h a n average regrade d slop e o f 3H:1 V an d draine d conditions , th e Facto r o f Safet y fo r Alternativ e C wa s greate r tha n 2.0

. I n addition , th e Facto r o f Safet y unde r pseudostati c condition s wa s determined

. Pseudostati c condition s wer e simulate d usin g th e seismi c acceleratio n coefficien t (k ) o f 0.04 g fo r 5 0 yea r return , this valu e wa s establishe d b y revie w o f publishe d dat a fo r Algermisse n (1991 ) an d was checke d agains t dat a publishe d b y Dame s an d Moor e in Stabilit y an d Reclamatio n Evaluatio n o f Abandone d Tailing s Pon d (1986)

. Th e Facto r o f Safet y fo r th e regrade d slope s unde r psuedostati c condition s i s 2.0

. A l l inputs , cross-sections , failur e surfaces
, an d result s ar e show n o n th e XSTAB L compute r printout s containe d in Appendi x E-l

.

H:\664VEECA\GARAPP-E.TX

T 06/01/9 5 7: 3 la m WP S 1/cm c E- lJuly

27, 1995 FINAL * EE/CA Garibaldi Mine Site * Appendices



### APPENDI X E- 1 XSTAB L COMPUTE R PRINTOUT S

H:\664\EECA\GARJBALD.FN

L 07/27/9 5 4:01p m WP51/cm cEXIS

T 4-12-9 5 12:1 6



### 22 5
_

195
_

0 ) 16 5 < D 

### C / 3 i — i 

## X < 13 5

10 5
_

7 5 

# GARIBALD I

EXISTIN G CONDITION S 1 0 mos t critica l surfaces
, MINIMU

M BISHO P FO S
- 1.035

3 0 T 6 0 90 12 0 15 0 

# X-AXI S (feet ) 180 21 0 24 0ISOTROPI

C Soi l Parameter s 

### 2 type(s ) o f soi l 

### Soi l Uni t Weigh t Cohesio n Frictio n Pore Pressur e Wate r Unit Mois t Sat

. Intercep t Angl e Paramete r

Constan t Surfac e 

### N o

. (pcf ) (pcf ) (psf ) (deg ) R u (psf

) No

. 1 126. 0 132. 0

. 0 36.0 0 .00 0

. 0 1 2 150. 0 150. 0

. 0 50.0 0 .00 0

. 0 1



### 1 Wate r surface(s ) hav e bee n specifie d Uni t weigh t o f wate r = 62.4 0 (pcf ) 

### Wate r Surfac e No

. 1 specifie d b y 2 coordinat e point s ********************************* * PHREATI C SURFACE
, ********************************* * 

### Poin t x-wate r

y-wate r N o

. (ft )

(ft ) 1 80.0 0

135.0 0 2 142.0 0

135.0 0 

### A critica l failur e surfac e searchin g method , usin g a rando m techniqu e fo r generatin g CIRCULA

R surface s ha s bee n specified

. 10 0 tria l surface s wil l b e generate d and analyzed

. 

### 1 0 Surface s initiat e fro m eac h o f 1 0 point s equall y space d 

### alon g th e ground surfac e betwee n x = 90. 0 f t an d x = 125. 0 f t 

### Eac h surfac e terminate s betwee n x = 126. 0 f t an d x = 212. 0 f t Unles s furthe r limitation s wer e imposed , th e minimu m elevatio n at whic h a surfac e extend s i s y = 120. 0 f t
5 . 0 f t lin e segment s defin e eac h tria l failur e surface

. ANGULA R RESTRICTION

S :m) l

4-12-9 5 12:2 4 

# C

22 5
_



### 195
_



## 0 ) 16 5
_ 0 ) 

### C / 3 i — i 

## X I 13 5
_

10 5
_

7 5 0 

# GARIBALD I

REGRADE D (.04G ) 1 0 mos t critica l surfaces
, MINIMU

M BISHO P FO S = 1.98 8

i 3 0 i 6 0 90 12 0 15 0 

# X-AXI S (feet ) 180 21 0 24 0Soi l

Uni t Weigh t Cohesio n

Frictio n Por e Pressur e Wate r 

### Uni t Mois t Sat

. Intercep t Angl e Paramete r

Constan t Surfac e N o

. (pcf ) (pcf ) (psf ) (deg ) R u (psf ) No

. 1 126. 0 132. 0

. 0 36.0 0 .00 0

. 0 1 2 150. 0 150. 0

. 0 50.0 0 .00 0

. 0 1



### 1 Wate r surface(s ) hav e bee n specifie d Uni t weigh t o f wate r = 62.4 0 (pcf ) 

### Wate r Surfac e No

. 1 specifie d b y 2 coordinat e point s ********************************* * PHREATI C SURFACE
, ********************************* * 

### Poin t N o

. 1 2 x-wate r

(ft )
80.0 0 142.0 0 

### y-wate r

(ft )
135.0 0 135.0 0 

### A horizonta l earthquak e loadin g coefficien t o f .04 0 ha s bee n assigne d A vertica l earthquak e loadin g coefficien t o f .00 0 ha s bee n assigne d 

### A critica l failur e surfac e searchin g method , usin g a rando m techniqu e fo r generatin g CIRCULA

R surface s ha s bee n specified

. 10 0 tria l surface s wil l b e generate d an d analyzed

. 1 0 Surface s initiat e fro m eac h o f 1 0 point s equall y space d alon g th e groun d surfac e betwee n x = 70. 0 f t an d x = 125. 0 f t 

### Eac h surfac e terminate s betwee n x = 126. 0 f t an d x = 212. 0 f t 

### Unles s furthe r limitation s wer e imposed , th e minimu m elevatio n 

### at whic h a surfac e extend s i s y = 120. 0 f t
5 . 0 f t lin e segment s defin e eac h tria l failur e surface

.(

!T0 1 4-12-9 5 12:2 6

22 5
_



## 195
_

0 ) 16 5
_ 0 ) 

### C O i — ( 

## X < C I 13 5
_

10 5
_

7 5 0 

# GARIBALD I

REGRADE D 1 0 most critica l surfaces
, MINIMU

M BISHO P FOS = 2.26 1

3 0 i 6 0 90 12 0 15 0 

# X-AXI S (feet ) 18 0 21 0 24 0

### saajBa

p (o* 9 - aifiu B adois ) = : q.TuiTT

. saaa£a p o*9fr

- = *



### a q TTT

W 

### aadd n

: A q pauTja p abue a aejnfiu B au;q . aanifeg : qoe a 3: 0 ^uauiba s q.safg f
auTjap sq.uaui6a s o * S



### ^• 5 0*02 T = A S T spuaq.x a aoejan s 

### wnuiTUTU i aiiq

. 'pasodur c a ja w ssaju n 0*92 1 

### paocd s =

x PU B O'O i = x uaaMq.aq aoejan s punoa£ > 

### sq.uTo d o i j o qoe a uioa j aq.BTq.TU t saoBjan s 0 1 P U B paq.Baaua 6 a q TTT

M 

### saoBjan s TBTJtq

. oo i •pajgiToad s uaa q s ^ saoBjan s HVinDHI D 6uTq.BJ:aua 6 ao j 

### B £>uTs n 'ponqau i fiuTqoaBa s aoBjan s aantTB j iBOTq.Ta o v 00*9CT 00-9C T OO'Sfr T 00*0 8 Z

I 

## • O N q.uTO d
********************************* *

********************************* * sq.uTo d 9q.BUTpaoo o z A q paTjToad s i -O N aoBjan s (jod ) Ofr'2 9 paTjToad s uaa q j o

q.qTa/ i q.Tu n (s)aoBjan s Jaq.B M T
I 

## i • O N 0 

## o * 00 0 

## oo o (jsd ) 

### qsuo aanssaa d 00*0 9



## oo*9 e (6ep ) 0 * 

## o * 0*09 1 0*09 1



## 0*92 1 Z 

## i (jod ) 

### qdaoaaqu i *q.B S (jod

) -O N 

### q^sjo w qT u 

### f l q.J u 

### n IT° SJuly

27 , 1995 FINA L * EE/CA Garibaldi Mine Site * Appendices



### APPENDI X F ARAR s

H:\664\EECA\GARBALD.FN

L 07/27/9 5 4:01p m WP51/cm c

### APPENDI X F ARAR s Thi s appendi x identifie s al l requirement s tha t EP A ha s determine d ar e Applicabl e o r Relevan t a n d Appropriat e Requirement s ("ARARs" ) fo r th e Garibald i Min e Sit e remova l action

. A s a matte r o f policy , EP A requires attainmen t o f ARAR s i n remova l actions t o th e greates t exten t practicabl e give n th e exigencie s a t a give n site

. Se e CERCL A Complianc e Wit h Othe r Law s Manua l a t xii , EPA-540-6-89-00 6

(Interi m Final
, Augus t 1988)

. EP A generall y determine s tha t complianc e wit h ARAR s i s practicabl e fo r "non-time-critical "

remova l actions , suc h as this one . Resurrectio n take s n o positio n wit h respec t t o th e propriet y o f thi s polic y an d i t reserve s al l right s tha t i t ma y hav e wit h respec t t o complyin g wit h it

. I n accordanc e wit h EPA' s directive , al l requirement s tha t EP A ha s determine d ar e ARAR s fo r thi s remova l actio n wil l b e me t unles s EP A determine s that complianc e i s no t practicabl e or complianc e i s waive d in accordanc e wit h Sectio n 300.430(f)(ii)(C ) o f th e Nationa l Contingency Plan

. Attainmen t o f water-qualit y based , chemical-specifi c ARAR s i s no t require d unti l implementatio n o f th e remedia l actio n fo r Site-wid e Surfac e an d Groun d Water s (see Resurrectio n WAM P § 4.6.5)

. T h e potentia l ARAR s identifie d belo w wer e selecte d based o n standards , guideline s an d criteri a foun d in relevan t literature ; discussion s wit h appropriat e regulatory agenc y personnel ; an d prio r projec t experience

. Th e principa l references use d were : • Preliminary Applicabl e o r Relevant an d Appropriat e Requirement s Analysis
, Appendi x A
, Fina l Screenin g Feasibilit y Stud y fo r Remedial Alternative s a t th e Californi a Gulc h NP L Site
, Leadville
, Colorad o (Septembe r 1993 ) (th e "Fina l SFS") ; • Guidanc e o n Conductin g Non-Time-Critica l

Remova l Action s Unde r CERCLA
, EPA/540/R-93/05 7 (Augus t 1993) ; • Guidanc e o n th e Consideratio n o f ARARs Durin g Remova l Actions
, EPA/540/P

91/01 1 (Septembe r 1991) ; an d
• CERCL A Complianc e Wit h Other Law s Manual
, EPA/540/G-89/006
,

(Interi m Final ) (Augus t 1988)

. A detaile d analysi s o f th e potentia l ARA R selectio n proces s an d a descriptio n o f th e term s use d belo w ca n b e foun d in Section s A l - A 5 o f th e Fina l SFS

. F . 1 CHEMICAL-SPECIFI

C ARAR S Chemical-specifi c requirement s are based on healt h or risk-base d concentratio n limit s or discharg e limitation s i n environmenta l medi a (i.e.
, water , air ) fo r specifi c hazardou s chemicals

. Thes e requirement s ma y b e use d t o se t cleanu p level s fo r the chemical s o f concer n (i n this case , metals ) i n the designate d media , or t o set a saf e leve l o f discharg e (e.g.
, wastewate r discharge , 

### takin g int o accoun t water qualit y standards ) wher e a discharg e occur s a s par t o f the remedia l activity

.

H:\664\EECA\GARIBALD\GARAPPF.TX

T 07/27/9 5 4:04p m WP S 1/cm c F- 1

### F.1. 1

Wast e Classificatio n The wast e unde r consideratio n i s wast e rock

. Th e sourc e o f contaminatio n i s th e Garibald i wast e roc k pile

. Base d o n 4 0 CF R 261.4(b)(7)
, thes e wastes ar e exclude d fro m Resource Conservatio n an d Recover y Ac t (RCRA ) Subtitle C

. Fo r thi s reason, RCR A Subtitl e C i s no t applicabl e a s a matte r o f la w t o thes e waste s fo r thi s remova l action

. Base d o n 6 CC R 1007-3 , Sectio n 261.4(b)(7)
, thes e wastes ar e als o exclude d fro m th e Colorad o Hazardou s Wast e Act

. Fo r thi s reason , th e Colorad o Hazardou s Wast e Ac t i s no t a potentia l ARA R fo r this remova l action

. 

### F.1. 2 T o B e Considere d Item s ("TBC") fo r Soi l T h e EP A ha s issue d a n Offic e o f Soli d Wast e an d Emergenc y Respons e (OSWER ) directiv e entitle d "Interi m Guidanc e o n Establishin g Soi l Lead Cleanu p Level s a t Superfun d Sites " (OSWE R Directiv e #9355.4-02 , Septembe r 1989)

. Th e directiv e set s fort h interi m soi l cleanu p level s whe n th e lan d us e i s residentia l an d i s intende d solel y a s guidance

. However
, Uppe r Californi a Gulc h i s no t designate d fo r residentia l us e no r does EP A forese e residentia l us e a s a reasonabl e futur e lan d use
. Fo r this reason , OSWE R Directiv e #9355.4-0 2 i s no t a potentia l ARA R fo r thi s remova l action

. F.1. 3 Summar y A s discusse d o n pag e F-l
, ther e ar e n o chemical-specifi c requirement s tha t ar e applicabl e o r relevan t an d appropriat e requirement s fo r thi s remova l action

. F . 2 LOCATION-SPECIFI

C ARAR S Location-specifi c ARAR s ar e restriction s place d o n th e type s o f activitie s tha t ma y occu r i n particula r locations

. Th e locatio n o f a sit e ma y b e a n importan t characteristi c i n determinin g i t s impac t o n publi c healt h an d th e environment ; thu s stat e standard s ofte n establis h location

specifi c ARARs

. Thes e ARAR s ma y restric t o r preclud e certai n remedia l actions o r ma y appl y onl y t o certain portion s o f a site

. Example s o f location-specifi c ARAR s includ e federa l an d stat e requirement s fo r preservatio n o f histori c landmarks , endangere d specie s an d wetland s protection , and floodplai n restriction s o n managemen t o f hazardou s waste

. 

### F.2. 1 Threatened/Endangere d

Specie s I f Threatened/Endangere d

specie s ar e foun d t o inhabit area s tha t wil l be impacte d b y activities , t h e Federa l Endangere d Specie s Ac t an d th e Stat e Nongame
, Endangered
, o r Threatene d Specie s Act wil l b e applicabl e and coordinatio n wit h federa l and stat e agencie s wil l b e needed t o implemen t mitigatio n measure s o r alternativ e remova l activities

. A Terrestria l Ecosyste m Evaluatio n (TEE ) (WCC
, 1993 ) wa s conducte d i n th e Californi a Gulc h sit e a s par t o f th e Phas e n Remedia l Investigations

. Th e TE E state d that n o evidenc e o f th e potentia l presenc e o f threatened , endangere d o r sensitiv e specie s wa s foun d withi n th e stud y are a (WWC
, 1993)

. Fo r thi s reason , th e Federa l Endangere d Specie s Ac t an d th e Stat e Nongam e Endangere d o r Threatene d Specie s Ac t ar e no t potentia l ARAR s fo r thi s remova l action

.

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### F.2. 2

Specie s o f Specia l Concer n an d Undetermine d Statu s Unde r Colorad o La w (o r policy)
, th e Colorad o Departmen t o f Natura l Resource s (CDNR ) ha s establishe d tw o designation s t o protec t wildlif e species

. Thes e tw o designation s ar e "specie s o f specia l concern " an d "specie s o f undetermine d status"

. Specie s o f specia l concer n ar e define d a s nativ e specie s or subspecie s whic h hav e bee n threatene d or endangere d or coul d becom e threatene d o r endangere d du e t o lo w populatio n levels

. Specie s o f undetermine d statu s ar e specie s abou t whic h to o littl e i s know n t o accuratel y determin e thei r statu s i n th e state

. Colorado' s Divisio n o f Wildlif e maintains a lis t o f specie s whic h hav e bee n determine d t o fit thes e categories

. I f specie s o f specia l concer n o r o f undetermine d statu s ar e foun d a t th e sit e an d
remova l activitie s coul d potentiall y impac t thos e specie s (o r their habitats)
, th e Divisio n o f Wildlife' s Directiv e E-l
, 198 5 (modified)
, shoul d b e take n int o consideratio n an d coordinatio n wit h th e Divisio n implemented

. Thes e interna l designation s woul d be potentia l T o B e Considere d (TBCs ) fo r thi s remova l actio n onl y i f specie s in eithe r categor y ar e foun d in Uppe r Californi a Gulch

. 

### F.2. 3 Colorad o Natura l Area s Progra m T h e Colorad o Natura l Areas Progra m maintains a lis t o f Plan t Specie s o f Specia l Concer n t o th e Stat e o f Colorado

. I t i s not authorize d b y statut e an d i s considere d a plannin g an d management tool

. I f remova l activitie s impac t plan t specie s maintaine d o n th e list , th e progra m i s a T o B e Considere d (TBC ) ARA R an d coordinatio n wit h th e Colorad o Divisio n o f Park s an d Outdoo r Recreatio n ma y b e required

. 

### F.2. 4 Cultura l Resource s Sectio n 10 6 o f th e Nationa l Histori c Preservatio n Ac t (NHPA ) i s a potentia l ARA R fo r thi s remova l actio n becaus e th e remova l actio n i s a n undertakin g unde r th e NHPA

. Th e Stat e Histori c Preservatio n Offic e (SHPO)
, however , ha s determine d tha t th e Garibald i propert y "i s no t individuall y eligible , i s no t withi n th e existin g Leadvill e Histori c Distric t an d woul d no t contribut e t o th e distric t expansion"

. Th e SHP O lette r i s include d i n Appendi x A

. Sectio n 110(f ) o f th e NHPA
, whic h establishe s procedures t o minimize har m t o Nationa l Histori c Landmarks
, i s no t applicabl e as Uppe r Californi a Gulc h doe s no t lie withi n th e Leadvill e Nationa l Histori c Landmark District

. Executiv e Orde r 1159 3 on th e Protectio n an d Enhancemen t o f th e Cultura l Environment i s a potentia l ARA R and require s consultatio n wit h the Counci l o n the preservatio n and enhancemen t o f histori c resource s i f remova l activitie s shoul d threate n them

. I f historica l and/o r archeologica l dat a are impacte d b y remova l activities , the Historica l and Archeologica l Preservatio n Ac t woul d als o b e a potentia l ARAR

. T h e Archeologica l Resource s Protectio n Ac t o f 197 9 provide s fo r th e protectio n o f cultura l resource s on publi c or India n land s and ma y b e a potentia l ARA R wit h respec t t o remova l actions impactin g suc h properties

. Th e Garibald i Min e Sit e remova l actio n wil l impac t onl y privat e lands , no t publi c o r India n lands

. T h e Stat e Historical
, Prehistorical
, an d Archeologica l Resource s Ac t addresse s th e loanin g o f archeologica l resource s o n state-owne d land t o scientifi c o r educationa l institutions

. Shoul d
remova l activitie s endange r an archeologica l sit e tha t ma y necessitat e remova l o f th e resource , th e procedure s outline d b y th e Ac t woul d b e a potentia l ARAR

. I n addition , i f remova l activitie s uncove r an y huma n remain s that ar e o f archeologica l interest , the procedure s fo r

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o f remain s unde r th e ac t woul d als o b e "applicabl e o r relevant , an d appropriate"

. Finally
, th e State' s Registe r o f Histori c Place s is a potentia l ARA R i f remova l activitie s may impac t an are a liste d on the Register

. 

### F.2. 5 Wetland s an d Floodplai n Managemen t Executiv e Order 1199 0 require s the avoidanc e o f lon g an d shor t ter m impact s associate d wit h th e destructio n o r modificatio n o f wetlands

. A wetlan d evaluatio n o f th e Californi a Gulc h sit e conducte d b y Woodward-Clyd e i n 199 2 di d not identif y wetland s at the Garibald i Min e Site

. However
, a comprehensiv e wetlan d surve y wil l be conducte d prio r t o th e implementatio n o f th e recommende d remova l action

. I f an y wetland s identifie d i n thi s surve y ar e impacte d b y th e remova l action , mitigatio n wil l b e addresse d durin g th e feasibilit y stud y fo r OU-4

. Mitigatio n wil l consis t o f wetlan d restoration , creatio n or enhancement i n appropriat e area s o f OU-4
, 8 , o r 10

. Executiv e Orde r 1198 8 o n Protectio n o f Floodplain s i s a potentia l ARAR

. Remova l mus t b e conducte d t o avoi d long

- an d short-ter m advers e impact s associate d wit h th e occupatio n o r modificatio n o f floodplains

. 

### F.2. 6 Clea n Wate r Ac t (Sectio n 404 ) Uppe r Californi a Gulc h i s on e o f th e majo r gulche s o n th e sit e an d contain s a n intermitten t strea m tha t federa l agencies , includin g th e EPA
, hav e determine d ar e "water s o f th e Unite d States " [3 3 CF R 328.3(a)]

. EP A has determine d tha t an y remova l r , ,</it y dischargin g fil l material s into , o r changin g th e botto m elevatio n of
, thes e drainage s (suu ; as strea m diversio n ditche s o r constructio n o f roa d crossing s whic h impac t th e drainages ) require s complianc e wit h th e dredg e an d fil l substantiv e requirement s o f Sectio n 40 4 o f th e Clea n Wate r Act

. Pursuant t o Sectio n 121(e ) o f CERCLA
, EP A i s no t require d t o appl y fo r an d obtain a Nationwid e permit

. Resurrectio n i s exemp t fro m th e permittin g proces s bu t i s require d t o demonstrat e substantiv e complianc e wit h th e requirement s o f Sectio n 404

. T h e recommende d remova l actio n fo r this EE/C A wil l avoi d dredg e an d fil l activitie s i n Uppe r Californi a Gulch

. A fina l determination , however , mus t b e mad e b y EPA

. 

### F.2. 7 Fis h an d Wildlif e Coordinatio n Ac t Activitie s suc h a s strea m flo w modificatio n an d constructio n o f reservoir s o r surge ponds , coul d impac t fis h an d wildlif e resource s in an d alon g thes e drainages

. Th e Fis h an d Wildlif e Coordinatio n Ac t i s a potentia l ARA R sinc e remova l activitie s ma y affec t o r modif y Uppe r Californi a Gulch

. EP A ma y nee d t o coordinat e wit h bot h U.S

. Fis h an d Wildlif e Servic e an d th e Colorad o Departmen t o f Natura l Resource s t o discus s mitigatio n measure s t o preven t los s or damag e t o thes e resources , i f necessary
. Th e implementatio n o f th e preferre d alternative s o f th e EE/C A wil l caus e a n improvemen t i n terrestria l habita t i n th e gulc h and a reductio n i n th e amoun t o f water-borne contaminatio n leavin g th e gulch

. Aquatic lif e doe s no t exis t i n Uppe r Californi a Gulch du e t o th e intermitten t flow s and poo r water quality

. Ther e wil l b e no los s o r damag e t o fis h o r wildlif e resource s i n 

### th e remediate d area , therefor e i t i s anticipate d tha t th e U.S

. Fis h an d Wildlif e Servic e an d th e Colorad o Departmen t o f Natura l Resource s wil l no t objec t t o th e preferre d alternativ e recommende d i n the EE/CA

.

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### F.2. 8

Summar y Potentia l location-specifi c ARAR s fo r remova l actio n i n Uppe r Californi a Gulc h ar e presente d i n Tabl e F.I

. Th e remova l actio n alternative s describe d i n thi s EE/C A hav e bee n prepare d i n accordanc e wit h and/o r evaluate d fo r complianc e wit h th e following location-specifi c ARARs : • Cultura l resourc e requirement s includin g Sectio n 10 6 o f th e NHP A • Clea n Wate r Ac t (Sectio n 404 ) • Fis h an d Wildlif e Coordinatio n Ac t F . 3 ACTION-SPECIFI

C ARAR S Action-specifi c ARARs ar e activity-base d requirement s triggere d b y th e particula r remova l activitie s selected

. Regulation s regardin g worke r healt h an d safet y (i.e.
, GSH A requirements )
ar e not technicall y ARAR s a s the y ar e not environmenta l o r publi c healt h requirements

. F.3. 1 Clea n Ai r Ac t T h e Clea n Air Ac t establishe s emissio n standard s fo r certai n categorie s o f industria l stationar y sources
. I t i s onl y applicabl e i f a remova l actio n creates ai r emissions regulate d b y thos e standards

. Remova l actio n activit y wil l involv e eart h movin g an d associate d dus t generation

. Fo r thi s reaso n th e Clea n Ai r Ac t i s a potentia l ARA R fo r thi s remova l action

. However
, thes e activitie s ar e regulate d unde r th e Colorad o Air Qualit y Contro l Ac t an d wil l b e addresse d unde r it s regulation s a s describe d below

. 

### F.3. 2 Colorad o Ai r Qualit y Contro l Ac t T h e Colorad o Air Qualit y Contro l Ac t establishe s emission s standard s fo r airborne particulate s an d lea d an d i s applicabl e i f a remova l actio n create s emission s o f regulate d materials

. Remova l actio n activit y wil l involv e eart h movin g an d associate d dus t generation

. Fo r thi s reaso n th e Colorad o Ai r Qualit y Contro l Ac t i s a potentia l ARA R fo r thi s remova l action

. I t i s anticipate d tha t th e remova l actio n wil l be exemp t fro m requirement s t o fil e a n Ai r Pollutio n Emissio n Notic e since disturbe d area s wil l no t excee d 2 5 acre s an d th e duratio n o f th e disturbanc e wil l no t excee d si x months

. However
, a s state d i n th e EE/CA
, dus t abatemen t wil l be practice d durin g construction

. A n ai r pollutio n contro l pla n wil l be prepare d an d submitte d i n th e Remedia l Desig n repor t tha t addresse s dust abatemen t durin g al l aspect s o f dir t wor k require d fo r th e implementatio n o f th e remova l action

. Dus t control s considere d i n th e ai r pollutio n contro l pla n includ e watering , chemica l stabilizers , compaction , enclosure s an d revegetation

. T h e regulatio n o f th e Colorad o Air Qualit y Contro l Commissio n require th e us e o f al l availabl e an d practica l method s whic h ar e technologicall y feasibl e an d economicall y reasonabl e i n orde r t o minimiz e emissions

. Th e applicabl e emissio n limitatio n guidelin e i s 20 % opacit y an d n o off

propert y transport

. 

### F.3. 3 Soli d Wast e Disposa l Act a s amende d b y the Resource Conservatio n and Recover y Act The Resourc e Conservatio n and Recover y Act (RCRA ) establishe s criteri a for us e i n determinin g whic h soli d wast e disposa l facilitie s an d practice s pos e a reasonabl e probabilit y o f advers e effect s
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health

. RCR A i s applicabl e t o lan d disposa l o f soli d waste

. Sinc e an y consolidatio n o r disposa l o f soli d waste s wil l occu r entirel y on-site , RCR A regulation s d o no t appl y t o this remova l action

. 

### F.3. 4 Hazardou s Material s Transportatio n Ac t T h e Hazardou s Material s Transportatio n Ac t regulate s th e off-sit e transportatio n o f hazardou s material s an d affect s packaging , placarding , us e o f prope r containers , an d reportin g o f discharges

. T h e removal actio n i n thi s EE/C A wil l no t entail off-site transportatio n o f hazardou s material s a n d therefor e th e Hazardou s Material s Transportatio n Ac t i s no t a potentia l ARA R fo r thi s removal action

. 

### F.3. 5 Occupationa l Healt h an d Safet y Ac t an d th e Federa l Min e Safet y an d Healt h Ac t T h e Occupationa l Healt h an d Safet y Ac t regulate s worke r healt h an d safet y in th e workplac e an d th e Min e Safet y an d Healt h Ac t establishe s requirement s t o safeguar d worke r safet y i n an d
aroun d mines

. Whil e eac h act wil l b e adhere d t o wher e applicable , neithe r i s a potentia l ARA R becaus e neithe r i s an environmenta l regulation

. 

### F.3. 6 Nationa l Pollutan t Discharg e Eliminatio n Syste m T h e Nationa l Pollutan t Discharg e Eliminatio n Syste m (NPDES ) require s permit s fo r discharg e o f pollutant s fro m an y poin t sourc e int o water s o f th e U.S.
, includin g discharge s o f stor m water

. T h e State o f Colorad o ha s a n approve d progra m fo r managin g th e NPDE S permit s withi n th e state

. Genera l permit s ma y be obtaine d unde r a categor y o f discharge s unde r th e Clea n Wate r A c t fo r stor m wate r poin t sources
. Th e NPDE S i s a potentia l ARA R fo r thi s remova l action

. A Constructio n Stor m Wate r Managemen t Pla n (CSWMP ) wil l b e prepare d an d submitte d wit h t h e Remedia l Desig n report

. Th e objectiv e o f th e CSWMP wil l b e t o identif y Bes t Managemen t Practice s (BMPs ) tha t wil l be use d t o reduc e th e pollutant s i n stor m wate r discharge s associate d wit h constructio n activities

. Th e CSWM P wil l b e prepare d accordin g t o guideline s provide d b y t h e State o f Colorad o i n thei r Genera l Permi t Applicatio n fo r Discharge s Associate d wit h Constructio n Activities

. Th e CSWM P wil l includ e a sit e description , sit e map , an d a descriptio n o f BMP s utilize d includin g structura l practice s (stra w bales , sil t fences
, dikes , swales)
, nonstructura l practice s (seeding
, mulching , geotextiles , preservatio n o f existin g vegetation)
, an d materia l handlin g an d spil l preventio n procedures

. 

### F.3. 7 Stat e Soli d Wast e Disposa l Site s an d Facilitie s Ac t T h e Stat e Soli d Wast e Disposa l Site s an d Facilitie s Ac t establishe s polic y fo r licensing , constructing , an d operatin g soli d wast e disposa l facilities

. Permit s are'no t require d fo r on-sit e activitie s at a sit e liste d o n th e NPL

. Remova l actions wil l no t involv e establishmen t o f a soli d wast e disposa l facility

. Fo r thi s reaso n th e Stat e Soli d Wast e Disposa l Site s an d Facilit y Ac t i s no t a potentia l action-specifi c ARA R fo r thi s remova l action

. 

### F.3. 8 Colorad o Mine d Land Reclamatio n Ac t T h e Colorad o Mine d Land Reclamatio n Ac t regulate s al l aspect s o f lan d us e fo r mining , includin g th e locatio n o f minin g operation s an d relate d reclamatio n activitie s an d othe r environmenta l and socioeconomi c impacts

. A permi t i s not require d fo r activitie s o n CERCL A

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.

EP A ha s determine d tha t th e followin g Colorad o Mine d Lan d Reclamaito n Boar d Rule s a r e potentia l ARAR s fo r thi s remova l action

. • Rul e 3 : Reclamatio n

Performanc e Standards
, Inspection
, Monitorin g an d Enforcement ; • Rul e 7 : Designate d Minin g Operations ; • Rul e 8 : Emergenc y Respons e Pla n fo r Designate d Minin g Operation s - Emergenc y Notificatio n b y Operators
, an d Emergenc y Respons e Authorit y o f th e Office

. T h e alternative s in thi s EE/C A wil l b e prepare d in accordanc e wit h an d evaluate d fo r complianc e wit h the Colorad o Mine d Lan d Reclamatio n Boar d Rule s 3 , 7 , and 8

. The requirement s o f Rul e 3 wil l be incorporate d i n th e Remedia l Desig n report , exceptin g reference s t o wate r qualit y standard s an d numeri c protectio n levels

. On e o f th e majo r requirement s o f rul e 7 i s a n Environmenta l Protectio n Plan

. Th e Remedia l Desig n repor t wil l contain a n outlin e o f th e requirement s o f th e Environmenta l Protectio n Pla n an d a descriptio n o f ho w th e applicabl e requirement s wil l b e met

. Rul e 8 require s an Emergenc y Respons e Plan

. A Contingency Pla n containin g a n Emergenc y Respons e Pla n wil l b e prepare d an d containe d i n th e Remedia l Desig n report

. 

### F.3. 9 Colorad o Nois e Abatemen t Ac t T h e Colorad o Nois e Abatemen t Ac t establishe s maximum permissibl e nois e level s fo r particula r tim e period s an d lan d us e zones
. Remova l actio n activitie s unde r thi s EE/C A wil l involv e

, constructio n

equipmen t an d therefore
, th e Nois e Abatemen t Ac t i s a potentia l ARAR

. A summar y o f th e regulation s i s provide d below

. Constructio n project s ar e subjec t t o th e maximu m permissibl e nois e level s specifie d fo r industria l zones
. Thes e are : 8 0 db(A ) fro m 7:0 0 a.m . t o nex t 7:0 0 p.m. ; 75db(A ) fro m 7:0 0 p.m

. t o nex t 7:0 0 a.m . Also
, i n th e hour s betwee n 7:0 0 a.m . an d th e nex t 7:0 0 p.m. , th e nois e level s ma y b e increase d b y te n db(A ) fo r a perio d no t t o exceed fiftee n minute s i n an y one-hou r period

. Soun d level s o f nois e shal l b e measured at a distanc e o f twenty-fiv e fee t o r mor e fro m the propert y line

. Sinc e th e Garibald i Min e sit e i s severa l hundre d fee t fro m th e neares t residence , i t i s no t anticipate d tha t excessiv e nois e wil l be a proble m durin g th e constructio n o f thi s alternative

. However
, i f excessiv e nois e become s a proble m step s considere d t o remediat e th e proble m include : 1 ) operatin g durin g limite d hours , 2 ) ensurin g prope r noise suppressio n equipmen t i s use d on equipment , and 3 ) installin g nois e screenin g or sound-proofing

. 

### F.3.1 0 Regulation s

o n th e Collectio n o f Aquati c Lif e T h e Regulation s o n th e Collectio n o f Aquati c Lif e ar e requirement s governin g th e collectio n o f wildlif e fo r scientifi c purpose s an d ar e applicabl e i f remova l actio n activitie s trigge r th e nee d fo r biologica l monitoring

. Remova l action s wil l no t trigge r biologica l monitorin g an d thes e Regulation s o n th e Collectio n o f Aquati c Lif e ar e no t potentia l ARARs

.

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### Summar y

Potentia l action-specifi c ARAR s fo r remova l actio n in this EE/C A ar e discusse d abov e an d presente d in Tabl e F.2

. Th e remova l actio n alternative s describe d in thi s EE/C A hav e been prepare d i n accordanc e wit h and/o r evaluate d fo r complianc e wit h th e following action-specifi c ARARs : Clea n

Ai r Ac t Nationa l Pollutan t Discharg e -Eliminatio n Syste m Colorad o Ai r Qualit y Contro l Ac t Colorad o Nois e Abatemen t Ac t Colorad o Mine d Land Reclamatio n Ac t

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C ARAR s Standard
, Requiremen t Criteria
, o r Limitatio n Citatio n Descriptio n FEDERA L Endangere d Specie s Ac t Fis h an d Wildlif e Coordinatio n Ac t Wildernes s Ac t Executiv e Orde r No

. 1 1 98 8 Floodplai n Managemen t Sectio n 404 , Clea n Wate r Ac t T h e Archaeologica l an d Histori c Preservatio n Act o f 1 97 4 Nationa l Histori c Preservatio n Ac t (NHPA ) E.O

. 1 1 59 3 Protectio n an d Enhancemen t o f th e Cultura l Environmen t T h e Archeologica l Resources Protectio n Ac t o f 197 9 Resourc e Conservatio n an d Recover y Ac t (RCRA)
, Subtitl e D 1 6 US C § 153 1 et seq
. 5 0 CF R § § 20 0 an d 40 2 1 6 US C § 661 et seq
. 4 0 CF R § 6.30 2
1 6 US C 1311,1 6 US C 668 ; 5 0 C F R 53 , 5 0 CF R 2 7 4 0 CF R § 6.30 2 (b ) Appendi x A
3 3 US C 125 1 et seq
. 4 0 CF R § § 230 , 23 1 3 3 CF R part s 320-33 0 1 6 US C 469 ; 4 0 CF R 6

. 30 1 (c )

1 6 US C § 47 0 e t se q 4 0 CF R § 6.30 1 (b ) 3 6 CF R § Par t 63, Part 65 , Par t 80 0 1 6 US C 47 0 16USC470aa-4701 1 4 0 CF R 258

. 10-1 5 Provid

e protectio n fo r threatene d an d endangere d specie s an d thei r habitat

. Thes e standard s requir e protectio n o f fis h an d wildlif e i n wate r resourc e developmen t programs , o r action s whic h impoun d diver t o r contro l o r modif y an y bod y o f water

. Limit s activitie s withi n area s designe d a s wildernes s area s o r Nationa l Wildlif e Refug e Systems

. Pertain s t o floodplai n managemen t an d constructio n an d impoundment s i n suc h areas
. Thes e standard s prohibi t discharg e o f dredge d o r fil l materia l int o water s o f th e Unite d State s withou t permit

. Establishe s procedure s t o provid e fo r preservatio n o f historica l an d archeologica l dat a which migh t b e destroye d throug h alteratio n o f terrai n a s a resul t o f a federa l constructio n projec t o r a federall y license d activit y program

. Expand s histori c preservatio n programs ; applie s t o resource s eligibl e fo r listin g o n t h e Natura l Registe r fo r Histori c Places

. Federa l agencie s directe d t o institut e procedure s t o ensur e program s contribut e t o t h e preservatio n an d enhancemen t o f non-federall y owned histori c resources
. Consultatio n wit h th e Advisor y Counci l o n Histori c Preservatio n required

. Require s a permi t fo r an y excavatio n o r remova l o f archeologica l resources fro m publi c land s o r India n lands

. Facilitie s wher e treatment , storage , o r disposa l o f soli d wast e wil l b e conducte d must mee t certai n locatio n standards

. Thes e includ e locatio n restriction s o n proximit y t o airports , floodplains
, wetlands , faul t areas , seismi c impac t zones , an d unstabl e areas
.

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# c
TABL E F. I POTENTIAL FEDERAL AN D STAT E LOCATION-SPECIFI

C ARAR s Standard
, Requiremen t Criteria
, o r Limitatio n Citatio n Descriptio n STAT E O F COLORAD O Nongame
, Endangere d o r Threatene d Specie s Ac t Colorad o Registe r o f Histori c Place s Colorad o Historical
, Prehistorical
, a n d Archaeologica l Resources Ac t Colorad o Specie s o f Specia l Concer n an d Specie s o f Undetermine d Statu s Colorad o Natura l Area s Stat e Soli d Wast e Disposa l Site s a n d Facilitie s Act
, Colorad o Revise d Statutes
, Titl e 30 , Articl e 2 0 , Section s 101-11 8 C R S

§ § 33-2-10 1 t o 10 8 C R S § § 24-80.1-10 1 t o 10 8 C R S § § 24-80-40 1 t o 41 0 130 1 t o 130 5 Colorad o Divisio n o f Wildlif e Administrativ e Directiv e E-1
, 1985, modifie d Colorad o Revise d Statutes
, Titl e 33, Articl e 33, Sec

. 10 4

6 CC R 1007- 2 6CC R 1007-2 , Part i Thes e

standard s provid e fo r th e regulatio n o f nongam e wildlif e an d threatene d an d endangere d species

. Authorize s Stat e Historica l Societ y t o nominat e propertie s fo r inclusio n o n Stat e Register

. Concern s historical , prehistorica l an d archaeologica l resources ; applie s onl y t o area s owned b y State o r it s politica l subdivision

. Protect s animal s liste d o n th e Colorad o Divisio n o f Wildlif e generate d list

. Coordinatio n wit h th e Divisio n o f wildlif e i s strongl y urge d i f anima l specie s ar e t o be impacted

. T h e Colorad o Natura l Area s Progra m maintain s a lis t o f plan t specie s o f specia l concer n fo r th e State

. Althoug h no t protecte d b y Stat e statue , coordinatio n wit h Divisio n o f Parks an d Outdoo r Recreatio n is recommende d i f activitie s wil l impac t liste d species

. Establishe s regulation s fo r soli d wast e managemen t facilities
, includin g locatio n standards

. Establishe s broa d citin g criteri a an d sit e evaluatio n procedure s fo r individua l storag e an d disposa l unit s (i.e.
, impoundments , landfills
, etc.)

H:\664\EECA\GARIBALD\GARAPPF.TX

T 07/27/9 5 4:04p m WP51/cm c F - 9TABL E F. 2 POTENTIAL FEDERAL AN D STAT E ACTION-SPECIFI

C ARAR s Standard
, Requiremen t Criteria
, o r Limitatio n Citatio n Descriptio n FEDERA L Clea n Ai r Ac t Soli d Wast e Disposa l Ac t a s amende d b y th e Resourc e Conservatio n an d Recover y Ac t o f 197 6 (RCRA ) Hazardou s Material s Transportatio n Ac t Occupationa l Healt h an d Safet y Ac t Federa l Min e Safet y an d Healt h A c t 4 2 US C § 7401-764 2 4 0 CF R 6 0 4 2 US C § 6901-698 7 4 0 CF R 25 7

4 9 US C § 1801-181 3 4 9 CF R 107 , 171-17 7 2 9 US C § 651-67 8 3 0 US C § 800-96 2 Establishe s

emissio n standard s fo r certai n categorie s o f industria l stationar y sources
. Establishe s criteri a fo r determining whic h soli d wast e disposa l facilitie s an d practice s pos e a reasonabl e probabilit y o f advers e effect s o n health

. Regulate s transportatio n o f hazardou s materials

. Regulate s worke r healt h an d safety

. Establishe s requirement s t o protec t worke r healt h an d safet y i n an d aroun d mines

. STAT E O F COLORAD O State Soli d Wast e Disposa l Site s a n d Facilitie s Ac t Colorad o Mine d Lan d Reclamatio n A c t Colorad o Ai r Qualit y Contro l Ac t Colorad o Nois e Abatemen t Ac t Colorad o Regulaito n fo r th e State Discharg e Permi t Syste m Regulation s o n th e Collectio n o f Aquati c Lif e 6CC

R 1007- 2 CR S 34-32- 1 0 1 t o 12 5 2CC R 407- 1 5CCR S 1001-1 , 3 , 4 , 5 , 8 , 1 0 CRS 25-12-10 1 t o 10 8 6.1.0 , 5 CC R 1002- 2 2CC R 406-8 , Ch

. 13 , Articl e III
, Sec

. 131 6 Establishe s

polic y fo r licensing , locating , constructin g an d operatin g soli d wast e facilities

. Regulate s al l aspect s o f lan d us e fo r mining , includin g th e locatio n o f minin g operation s an d relate d reclamatio n activitie s an d othe r environmenta l an d socio

economic impacts

. Establishe s emission s standard s fo r particulate s an d lead

. Establishe s maximu m permissibl e nois e level s fo r particula r tim e period s an d us e zones
. lan d Establishe s regulation s fo r stormwate r runof f a t constructio n sites

. Requirement s governin g th e collectio n o f wildlif e fo r scientifi c purposes

.

H:\664\EECA\GARIBALD\GARAPPF.TX

T 07/27/9 5 4:04p m WP51/cm c F-1 0F . 4

REFERENCE S Unite d State s Army Corp s o f Engineer s (COE)
, 1985

. Regulatory Progra m Applican t Information

. E P 1145-2-1 , May

. Foothill s Engineerin g Consultant s (FEC)
, 1993

. Cultura l Resource s Surve y o f Propose d RI/F S Samplin g Location s i n Orego n Gulch
, Californi a Gulc h Superfun d Site
, Lak e County
, Colorado

. October

. R o y F

. Weston
, Inc

. an d Terr a Technologie s (Weston)
, 1995

. Preliminar y Ecologica l Ris k Assessmen t fo r Orego n Gulc h (O U 10)

. January

. Woodward-Clyd e Consultant s (WWC)
, 1992

. Wetland s Ma p fo r Californi a Gulc h RI/F S Stud y Area

. September

. Woodward-Clyd e Consultant s (WWC)
, 1993

. Terrestria l Ecosyste m Evaluatio n Repor t Californi a Gulc h Site
, Leadville
, Colorado

. April

.

H:\664VEECA\GARBALD\GARAPPF.TX

T 07/27/9 5 4:04p m WP51/cm c F-l lJuly

27, 1995 FINAL * EE/CA Garibaldi Mine Site * Appendices



### APPENDI X G COS T ESTIMATE S

H:\664\EECA\GARffiALD.FN

L 07/27/9 5 4:01p m WP51/cm cCaliforni a

Gulc h NP L Sit e OU- 4 Engineerin g Evaluation/Cos t Analysi s - Garibald i Min e Site 

### Alternativ e A

- Diversio n Channel s DIREC T CAPITA L COST S 

### Componen t Uni t Uni t

Cost Quantit y Tota l Cost Sourc e 

### Construc t Ditches Improv e Acces s Roa d Ripra p 

### Hau l Ripra p Filte r Fabri c Plac e Ripra p Concret e line r Culvert s Porta l wor k Cultura l Resource s Revegetatio n Dus t Contro l 

### Sedimen t Contro l cu-y

d lum p cu-y d cu-y d sq-f t 

### cu-y d sq-f t lum p lum p lum p acr e lum p lum p $25.0 0 $11.2 0 $12.6 0 $0.2 5 $15.0 0 $7.5 0
$3,00 0 29

4 19 3 19 3 7.00 0 19 3 5,49 7

0. 2 $7,35 0 $10,00 0 $2,16 2 $2,43 2 $1,750 $2,89 5 $4 1 ,22 8 $8,00 0 $10,00 0 $3,00 0 $60 0 $2,00 0 $2,00 0 

### Idarad o Cost s S M I ASI-RCC
, Buen a Vist a ASI-RCC
, Buen a Vist a 

### Previou s Project s 

### Idarad o Cost s Idarad o Cost s Previous Project s Previous Project s Previous Project s R B I Landscap e 

### Previou s Project s Previou s Project s 

## ,c o 

## ,c o

TOTA L DIREC T CAPITA L COST S $93,41 6 INDIRECT CAPITAL COST S 

### Engineerin g an d Desig n (10 % o f Direct ) Contingenc y (25 % o f Direct ) Lega l Fee s (5 % o f Direct ) Regulator y Cost (5 % o f Direct ) 

### Mobilizatio n and Demobilizatio n (10 % o f Direct ) EP A Fee s (20 % o f Engineering
, 5 % o f Direct ) TOTA L INDIREC T CAPITA L COST S TOTA L CAPITA L COST S $9,342

$23,35 4 $4,67 1 $4,67 1 $9,34 2 $6,53 9 $57,91 8 $151,33 4 POS T REMOVA L SIT E CONTRO L COST S 

### Discount 7.00 % for presen t wort h Componen t Uni t Present

Uni t cos t Eac h Each/y r $/yea r Year s Wort h DIREC T OPERATIO N AN D MAINTENANC E 

### Inspectio n hour Erosio n Repai r lum p Vegetatio n Repai r lum p TOTA L INDIREC T OPERATIO N AN D 

### Administratio n (5 % o f direct ) Misc

. fee s (5%o f direct ) 

### Reserv e (25 % o f direct ) $40.0

0 $2,00 0 $15,00 0 MAINTENANC E $55 6 $55 6 $2,77 8 8 1 0 COST S 1 1 1 4 1 0

1 1 1 $1,28 0 $2,00 0 $ 0

$55 6 $55 6 $2,77 8 4 4 4

4 4 4 $4,33 6 $6.77 4 $ 0 $11.11 0 $1,88 2 $1,882 $9,40 8 

## TOTA L OPERATIO N AN D MAINTENANC E PRESEN T WORT H ( 4 years ) $13,17 1 $24,28 1 GRAN D TOTA L $175,61 5Californi a

Gulc h NP L Sit e OU- 4 Engineerin g Evaluation/Cos t Analysi s - Garibald i Min e Sit e Alternativ e C

- Diversio n Channels/Groundwate r

Intercepto r Trench/ Regrade/Simpl e Cove r DIREC T CAPITA L COST S Componen t Uni t Uni t

Cost Quantit y Tota l Cost Sourc e Construc t Ditches Improv e Acces s Roa d Ripra p Hau l Ripra p Filte r Fabri c Plac e Ripra p Concret e line r Culvert s Groundwate r Trenc h Regrad e Cove r Soi l Suppl y Cove r Soi l Placemen t Revegetatio n Porta l wor k Cultura l Resource s Dus t Contro l Sedimen t Contro l cu-y

d lum p cu-y d cu-y d sq-f t cu-y d sq-f t lum p eac h cu-y d cu-y d cu-y d
acre s lum p lum p lum p lum p $25.0 0 $11.2 0 $12.6 0 $0.2 5 $15.0 0 $7.5 0 $10,00 0 $1.0 0 $10.0 0 $1.7 5 $3,00 0 27 5 19 3 19 3 7,00 0 19 3 5,12 0 2 3,10 0 4,10 0 4,100 1. 8 $6.87 5 $20,00 0 $2,16 2 $2,43 2 $1,750 $2,89 5 $38,40 0 $4,00 0 $20,00 0 $3,10 0 $41,00 0 $7,17 5 $5,40 0 $10,00 0 $5,00 0 $2,00 0 $2,00 0 Idarad o Cost s S M I ASt-RCC
, Buen a Vist a , ASI-RCC
, Buen a Vist a , Previous Project s Idarad o Cost s Idarad o Cost s Means Previou s Project s Previou s Project s C O C O

Webste r San d an d Grave l Idarad o Cost s R B I Landscapin g Previou s Project s Previou s Project s Previou s Project s Previous Project s TOTA L DIREC T CAPITA L COST S $174,18 8 INDIRECT CAPITAL COST S Engineerin g an d Desig n (10 % o f Direct ) Contingency (25 % o f Direct ) Lega l Fee s (5 % o f Direct ) Regulatory Cos t ( 5 % o f Direct ) Mobilizatio n an d Demobilizatio n (10 % o f Direct ) EP A Fee s (20 % o f Engineering
, 5 % o f Direct ) TOTA L INDIREC T CAPITA L COST S TOTA L CAPITA L COST S $17,41 9

$43,54 7 $8,70 9 $8,70 9 $17,41 9 $12,19 3 $107,99 7 $282,18 5 POS T REMOVA L SIT E CONTRO L COST S Discount 7.00 % for presen t wort h Componen t Uni t Unit

cos t Eac h Each/y r Presen

t $/yea r Year s Wort h DIREC T OPERATIO N AN D MAINTENANC E Inspectio n hou

r Erosio n Repair lum p Vegetatio n Repair lum p TOTA L INDIREC T OPERATIO N AN D Administratio n (5 % o f direct ) Misc

. fee s (5%o f direct ) 

### Reserv e (25 % o f direct ) 

### $40.0

0 $2,00 0 $2,40 0 MAINTENANC E $96 2 $96 2 $4,81 0 8 1 1 COST S 1 1 1 4 1 1

1 1 1 $1,28 0 $2,00 0 $2,40 0

$96 2 $96 2 $4,81 0 4

4 4

4 4 4 $4,33 6 $6,77 4 $8,129 $19,239 $3,25 8 $3.25 8 $16,29 2 TOTA L OPERATIO N AN D MAINTENANC E PRESEN T WORT H ( 4 years ) $22,80

9 $42,04 8 GRAN D TOTA L $324,23 3CALIFORNI

A GULC H NP L SITE O U 4 ENGINEERIN G EVALUATION/COS

T ANALYSIS

- GARIBALD I MIN E SIT E WAST E ROC K REMOVA L UNI T COS T DATE : 29-May-9 5 REMOVE$.WQ 1 EQUIPMEN T REQUIRE D

- 4 1 2 C Y TRUCK S

- 1 EXCAVATO R

- 1 DOZE R

- 1 WATE R TRUC K

- 1 MOTO R GRADE R PRODUCTIO N HAU L TIM E RETUR N TIM E FIXE D TIM E TOTAL CYCL E TIM E TRIP S PE R HOU R TRUC K CAPACIT Y R A W PRODUCTIVIT Y UTILIZATIO N (5 0 MIN/HR ) ADJ

. PRODUCTIVIT Y FLEE T PRODUCTIVIT Y 15. 0 MIN

. 12. 0 MIN

. 5 MIN

.

4 TRUCK S 32. 0 MIN

. 1.8 8 TRIPS/HOU

R 1 2 LC Y 2 3 LCY/H R 0.8 3 1 9 LCY/SC H H R 7 5 LCY/SC H H R SCRAPE R FLEE T COS T EQUIPMEN T TRUCK S EXCAVATO R DOZE R MOTO R GRADE R (16G ) WATE R TRUC K FORMA N AN D TRUC K UNIT S

4 1 1 0.5 0 0.5 0 1 UNI T

COS T $60.0 0 $90.0 0 $70.0 0 $75.0 0 $45.0 0 $32.0 0 TOTA L TOTA

L COS T $240.0 0 $90.0 0 $70.0 0 $37.5 0 $22.5 0 $32.0 0 /SC H H R /SCH H R /SCH H R /SCH H R /SCH H R /SCH H R $492.0 0 /SC H H R TOTAL UNI T COS T DIREC T OVERHEA D AN D PROFI T (25 % o f direct ) TOTA L $6.5 9 /LC Y $1.6 5 /LC Y $8.23 /LC Y

# TerraMatri x Engineerin g & Environmenta l Service s •^BHiB^BffCTlB M 147 5 Pin e Grove Roa d • P O Bo x 77401 8 Steamboa t Springs
, Colorad o 8047 7 303-879-626 0 • fa x 303-879-904 8 Jul y 27 , 199 5 Ms

. Denis e Lin k EP A Region 8, 8HWM-S R 99 9 18t h Street
, Suit e 50 0 Denver
, Colorad o 80202-240 5 Re : Submitta l o f Final Engineering Evaluation/Cost Analysis fo r Garibaldi Mine Site Within Upper California Gulch Operable Unit 4. Dea r Ms

. Link : O n behal f o f Resurrectio n Minin g Company
, enclose d are thre e copie s o f the Final EE/CA for Garibaldi Mine Site Within Upper California Gulch Operable Unit 4

. Thi s fina l EE/C A incorporate s comment s receive d fro m th e publi c durin g th e publi c commen t perio d an d provide s responses t o thos e comments

. W e wil l distribut e copie s t o additiona l partie s upo n you r approval

. I f yo u hav e an y comment s o r questions , pleas e contact me . Sincerely
, TerraM ; Ala n Projec t JMR:cm c encl

.
cc : Dav e Baker
, Resurrectio n Minin g Compan y ( 1 copy ) Eilee n Josselyn
, Ro y F

. Westo n ( 1 copy ) T o m Shepherd
, Shepher d Miller
, Inc

. ( 2 copies ) Bruc e Featherstone
, Kirklan d & Elli s ( 1 copy ) Rus s Alien
, CDPH E ( 2 copies ) Don Deere
, Rock y Mountai n Consultant s ( 1 copy )

H:\664Wissub.lt r Steamboa t Springs
, C O • Denver
, CO

. For t Collins
, C O • Seattle
, WA

. Juneau
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