522946

RECORD OF DECISION

STOCKPILED FINE SLAG ARKANSAS VALLEY SMELTER SLAG PILE CALIFORNIA GULCH SUPERFUND SITE (OPERABLE UNIT 3) LEADVILLE, COLORADO

May 1998

U.S. Environmental Protection Agency

999 18th Street, Suite 500 Denver, Colorado 80202
Federal Programs Corporation

ASubsxSaiyotCampDmsser&UcKeelnc.

1526 Cole Boulevard, Suite 150 Golden, Colorado 80401 Tel: 303 232-0131 Fax: 303 232-0904

M ay 15,1998

Ms. Rebecca Thomas U.S. Environmental Protection Agency Region VIII, Mail Code (8EPR-SR)

999 18th Street, Suite 500 Denver, CO 80202-2466

Project: RAC Region VIII, Contract No. 68-W5-0022 Work Assignment No.014-RSBD-0829

DCN: 3280-014-RT-DECD-02656

Subject: Final Record of Decision for Stockpiled Fine Slag, Arkansas Valley Smelter Slag Pile, California Gulch Superfimd Site (OU3), Leadville Colorado.

Dear Ms. Thomas:

Enclosed please find 10 copies of the May 1998 Final Record Of Decision for Stockpiled Fin e Slag, Arkansas Valley Smelter Slag Pile, Operable Unit 3 of the California Gulch Superfund Site, Leadville Colorado. The signed signature page has been incorporated

into these copies. If you have any questions or comments regarding this document please

feel free to call.

Sincerely,

C OM FEDERAL PROGRAMS CORPORATION

K en Black Project Manager

Enclosures

J im Moore Task Manager

cc: DCN

P:\3280-014\FINALROD\RODTRANZDFTOlJ3.wpd
RECORD OF DECISION

STOCKPILED FIN E SLA G ARKANSAS VALLEY SMELTER SLAG PILE CALIFORNIA GULCH SUPERFUND SITE (OPERABLE UNIT 3) LEADVILLE, COLORADO

The U.S. Environmental Protection Agency (EPA), with the concurrence of the Colorado Department of Public Health and Environment (CDPHE), presents this Record of Decision

(ROD) for stockpiled fine slag at the Arkansas Valley smelter slag pile of Operable Unit 3 (OU

3) within the California Gulch Superfund Site in Leadville, Colorado. The ROD is based on the Administrative Record for California Gulch OU3, including the Remedial Investigation/ Feasibility Study (RI/FS), the Proposed Plan, and the public comments received. The ROD

presents a brief summary of the RI/FS, actual and potential risks to human health and the

environment, and the Selected Remedy. EPA followed the Comprehensive Environmental Response, Compensation, and Liability Act, as amended, the National Contingency Plan (NCP),

and appropriate guidance in preparation of the ROD. The three purposes of the ROD are to:

1. Certify that the remedy selection process was carried out in accordance with the

requirements of the Comprehensive Environmental Response, Compensation, and Liability Act, 42 U.S.C. 9601 et seq., as amended by the Superfun d Amendments

and Reauthorization Act (collectively, CERCLA), and, to the extent practicable,

t he NCP;

2. Outline the engineering components and remediation requirements of the Selected Remedy; and

3. Provide the public with a consolidated source of information about the history,

characteristics, and risk posed by the conditions of the stockpiled fine slag at the Arkansas Valley Smelter slag pile of OU 3, as well as a summary of the cleanup

alternatives considered, their evaluation, the rationale behind the Selected Remedy, and the agencies consideration of, and responses to, the comments

received.

The ROD is typically organized into the followin g three distinct sections:

1. The Declaration section functions as an abstract for the key information

contained in the ROD and is the section of the ROD signed by the EPA Acting Regional Administrator and the CDPHE Director;

2. The Decision Summary section provides an overview of the OU 3 characteristics,

the alternatives evaluated, and the analysis of those options. The Decision Summary also identifies the Selected Remedy and explains how the remedy

fulfills statutory requirements; and

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3. The Responsiveness Summary section addresses public comments received on

the Proposed Plan, and other information in the Administrative Record. However,

since the EPA did not receive any written public comments, this ROD will not

contain a Responsiveness Summary.

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DECLARATION

Record ofDecision Stockpiled Fine Slag (OU 3)

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DECLARATION

SITE NAME AND LOCATION

Stockpiled Fine Slag Arkansas Valley Smelter Slag Pile California Gulch Superfund Site (Operable Unit 3) Leadville, Colorado

STATEMENT OF BASIS AND PURPOSE

This decision document presents the Selected Remedy for stockpiled fine slag at the Arkansas Valley smelter slag pile of Operable Unit 3 within the California Gulch Superfund Site in Leadville, Colorado. EPA, with the concurrence of CDPHE, selected the remedy in accordance

with CERCLA and the NCP. Note that this decision addresses stockpiled fine slag only. Other

activities required for OU3, including other slag piles, the railroad easement, and the railroad

yard, are addressed under a Consent Decree with the Denver & Rio Grande Western Railroad.

This decision is based on the Administrative Record for the stockpiled fine slag at the Arkansas Valley smelter slag pile of OU 3 within the California Gulch Superfund Site. The Administrative Record (on microfilm) and copies of key documents are available for review at

the Lake County Public Library, located at 1115 Harrison Avenue in Leadville, Colorado, and at

the Colorado Mountain College Library, in Leadville, Colorado. The complete Administrative Record may also be reviewed at the EPA Superfund Records Center, located at 999 18th Street,

5th Floor, North Terrace in Denver, Colorado.

ASSESSMENT OF THE SITE

The stockpiled fine slag at the Arkansas Valley smelter slag pile does not present an imminent or

substantial endangerment to public health, welfare, or the environment.

DESCRIPTION OF THE SELECTED REMEDY

The Selected Remedy is the No Action Alternative, which was presented in the Final Stockpiled Fine Slag Feasibility Study Report (FS) (Terranext, 1996a). The FS used a comparative analysis

to evaluate several alternatives and identify the advantages and disadvantages of each. Selection

of the No Action Alternative was based on this analysis. For the stockpiled fin e slag, the Selected Remedy leaves the slag piles in their existing condition with no remediation,

engineering controls, long term maintenance, or clean up planned. The Selected Remedy is

protective of human health and the environment, and is considered effective because 1) no

complete human or ecological exposure pathways were identified for the stockpiled fine slag and

2) the potential for release of metals in leachate from the stockpiled fine slag is minimal.

The Selected Remedy provides a contingency for resource utilization, which may be undertaken

in the future if regional market demand exists for the material. Resource utilization involves the

Record of Decision Stockpiled Fin e Slag (OU 3) ^ . SI2W:\32SCM>I4\FINALROD\OU3ROD2.WPD J-1

"

1
use or reuse of the slag material as a commercial product Due to concerns about the potential

for release of airborne participates if resource utilization is undertaken, the EPA has determined

that resource utilization of the stockpiled fine slag is only appropriate if it is encapsulated for

reuse. Encapsulation can include the use of fine slag in concrete or asphalt aggregate; or as road

base, backfill or other construction material as long as the fine slag is chemically bound or

physically separated from any exposure scenario by a barrier consisting of another material. Dust suppressants to control paniculate emissions and best management practices to control

stormwater runoff would also bo employed to contain contaminant releases from the fine slag

stockpile and during implementation of the contingency remedy. Resource utilization must also

take into consideration any toxic leaching potential for the fine slag.

DECLARATION STATEMENT

No remedial action is necessary to ensure protection of human health and the environment.

Max H. Dodson Date Assistant Regional Administrator

Ecosystems Protection and Remediation U.S. Environmental Protection Agency, Region VIII

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DECISION SUMMAR Y

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TABLE OF CONTENTS

LIST OF FIGURES ........................................................ DS-iii

LIST OF TABLES ......................................................... DS-iv

LIST OF ACRONYMS AND ABBREVIATIONS ..............................

:

. DS-v

1 .0 SITE NAME, LOCATION, AND DESCRIPTION ......................... DS

2 .0 OPERABLE UNIT HISTORY AND ENFORCEMENT ACTIVITIES .......... DS-3

3 .0 HIGHLIGHTS OF COMMUNITY PARTICIPATION ....................

4.0 SCOPE AND ROLE OF OPERABLE UNIT .............................. DS-7

5 .0 SUMMARY OF SITE CHARACTERISTICS ............................. DS

6 .0 SUMMARY OF SITE RISKS ......................................... DS-13

6 .1 RESIDENTIAL EXPOSURE TO SLAG .......................... DS-13

6 .2 RESIDENTIAL EXPOSURE TO IMPACTED GROUNDWATER ..... DS-14

6 .3 RECREATIONAL USER EXPOSURE TO SLAG ................. DS-14

6.4 WORKER EXPOSURE TO SLAG ............................... DS-14

6 .5 ENVIRONMENTAL EXPOSURE TO SLAG ...................... DS-15

6.5.1 AQUATIC EXPOSURE ................................. DS-15

6.5.2 TERRESTRIAL EXPOSURE ............................. DS-15

7.0 DESCRIPTION OF ALTERNATIVES ................................. DS

8 .0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES ........ DS-

8 .1 EVALUATION AND COMPARISON CRITERIA .................. D

8.1.1 THRESHOLD CRITERIA ............................... DS-

8.1.2 PRIMARY BALANCING CRITERIA ...................... 

8.1.3 MODIFYING CRITERIA ................................ D

8 .2 EVALUATING THE STOCKPILED FINE SLAG ALTERNATIVES .. . DS-

8.2.1 OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT ...................................... DS

8.2.2 COMPLIANCE WITH APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARs) ............... 

8.2.3 LONG-TERM EFFECTIVENESS AND PERMANENCE ...... DS-19

8.2.4 REDUCTION OF TOXICITY, MOBILITY, OR VOLUME THROUGH TREATMENT ............................... DS

8.2.5 SHORT-TERM EFFECTIVENESS ........................ 

8.2.6 IMPLEMENTABILITY ................................. 

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8.2.7 COST ................................................ DS-21

8.2.8 STATE ACCEPTANCE ................................. DS-22

8.2.9 COMMUNITY ACCEPTANCE ........................... DS

8.2.10 SUMMARY ........................................... DS-22

9.0 SELECTED REMEDY .............................................. DS-24

10.0 STATUTORY DETERMINATIONS ..................................

10.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT ... DS-25

10.2 COMPLIANCE WITH ARARs ................................. DS-26

10.3 COST EFFECTIVENESS ...................................... DS-26

10.4 UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT TECHNOLOGIES (OR RESOURCE RECOVERY TECHNOLOGIES) TO THE MAXIMUM EXTENT POSSIBLE ....... DS-26

10.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT .... DS-26

11.0 DOCUMENTATION OF SIGNIFICANT CHANGES ..................... DS

12.0 REFERENCES .................................................... DS-28

APPENDIX A

ARARs ........................................................... DS-30

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FIGUR E

Figure 1

Figure 2

Figures

LIST OF FIGURES

General Location Map, California Gulch Superfund Site

California Gulch Superfund Site and Operable Units.

Arkansas Valley Slag Pile Current Surface Areas, Volumes, and Angles of Repose

Figure 4 Arkansas Valley Slag Pile Sample Locations and Reconnaissance Information

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LIST OF TABLES

TABL E

Table 1 Estimates of Costs for Remedial Alternatives

Table 2 Grid Comparison Method for Alternatives Analysis

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LIST OF ACRONYMS AND ABBREVIATIONS

AMSL Above Mean Sea Level AOC Administrative Order of Consent ARAR Applicable or Relevant and Appropriate Requirements AV Arkansas Valley BMP Best Management Practices CDPHE Colorado Department of Public Health and Environment CERCLA Comprehensive Environmental Response, Compensation and Liability Act C FR Code of Federal Regulations D&RGW Denver and Rio Grande Western Railroad

EPA U.S. Environmental Protection Agency FS Final Stockpiled Fine Slag Feasibility Study mg/kg milligram per kilogram

mph miles per hour N CP National Oil and Hazardous Substances Pollution Contingency Plan N PL National Priorities List OU Operable Unit

p pm parts per million PRPs Potentially Responsible Parties RI/FS Remedial Investigation/Feasibility Study ROD Record of Decision S FS Screening Feasibility Stud y SPLP Synthetic Precipitation Leaching Procedure

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5I298P:\3280-014\FINALROD\OU3ROD2.WPD DS-v
1 .0 SITE NAME, LOCATION, AND DESCRIPTION

Stockpiled Fine Slag Arkansas Valley Smelter Slag Pile California Gulch Superfund Site (Operable Unit 3) Leadville, Colorado

The California Gulch Superfund Site is located in Lake County, Colorado, in the upper Arkansas River basin, approximately 100 miles southwest of Denver (see Figure 1). The Site encompasses

approximately 16.5 square miles and includes the towns of Leadville and Stringtown, a portion

of the Leadville Historic Mining District, and the portion of the Arkansas River from its

confluence with California Gulch downstream to the Lake Fork Creek confluence. The California Gulch Superfund Site has been organized into 12 operable units (OUs). Figure 2

shows the Site boundaries and the location of OU 3.

Operable Unit 3 (Figure 2) includes three slag piles (Arkansas Valley , La Plata, and Harrison St.)

owned by Denver and Rio Grande Western Railroad (D&RGW), a railyard right-of-way through Leadville and a railyard in the area of Leadville known as Poverty Flats. This Record of Decision (ROD) addresses only the fine slag1

 stockpiled as a subpile of the Arkansas Valle y

(AV) Smelter Slag Pile. In addition, D&RGW has identified a small volume of fine slag in the

railyard (Poverty Flats). D&RGW has prepared a plan which addresses removal of the fine slag

from this area to the AV Smelter Slag Pile (EPA, 1996).

The AV Smelter Slag Pile is the largest and westernmost of the three slag piles owned by D&RGW in the Leadville area (Figure 2). This pile was generated from slag produced primarily

by the AV smelter facility , which operated from 1882 to 1960. The pile covers approximately 40

acres and is approximately 9,800 feet above mean sea level (AMSL). Based upon aerial

photography, the pile volume in the late 1950s was approximately 1.2 million cubic yards. Today, approximately 422,000 cubic yards of slag remain on the AV Smelter Slag Pile. The

volume of stockpiled fine slag at the AV Smelter Slag Pile is approximately 190,000 cubic yards. The slag pile was purchased by D&RGW from ASARCO in 1961 for use as ballast (Terranext,

1996a).

The AV Smelter Slag Pile is bounded by Leadville Sewage Treatment Plant property and State Highway 24 to the south, old smelter works to the north, wooded property to the west, and other

smelter-related wastes and Stringtown to the east. California Gulch runs adjacent to the slag pile

vicinity for approximately 1/5 its length. D&RGW has performed work near the California Gulch to minimize the direct contact of surface water with the slag piles. In the vicinity of the AV Smelter Slag Pile, clean fill has been bermed along the toe of the slag to prevent direct

surface water from contacting the slag (Terranext, 1996a).

'Fine slag is sorted slag which is less than 3/8 inch. Sorted slag is slag that has been physicall y separated

into size fractions for the purpose of railroad ballast production (Terranext, I996a). .

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Lake County is relatively small (380 square miles) and is predominately rural, with a 1990

population of 6,007 (U.S. Department of Commerce, 1990). About half of this population

resides within the City of Leadville. The population of Lake County has fluctuated with the

mining industry. The population increased to about 9,000 between 1960 and 1981 and then

declined throughout the 1980's. Land surrounding OU3 is predominately dedicated to mining,

commercial, and residential uses.

The climate of Lake County is dry but otherwise typical of most alpine regions in the southern Rocky Mountains. The average annual maximum temperature in the Leadville area is 50.5

degrees Fahrenheit and the average annual minimum temperature is 21.9 degrees Fahrenheit,

with an annual mean temperature of 37.3 degrees Fahrenheit. The south-central portion of the

county, at an elevation near 9,000 feet AMSL, receives about 10 inches of precipitation annually. Wind is predominantly from the northwest, with speeds typically from 0 to 30 miles per hour

(mph) (WCC, 1993). Populated areas of Leadville are predominantly upwind of the AV Smelter Slag Pile.

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2 .0 OPERABLE UNIT HISTORY AND ENFORCEMENT ACTIVITIES

The California Gulch Superfund Site is located in the highly mineralized Colorado Mineral Belt

of the Rocky Mountains. Mining, mineral processing, and smelting activities have produced

gold, silver, lead, and zinc for more than 130 years in the Leadville area. Mining and its related

industries continue to be a source of income for both Leadville and Lake County. The Leadville Historic Mining District includes an extensive network of underground mine workings in a

mineralized area of approximately 8 square miles located around Breece Hill. Mining in the District began in 1860, when placer gold was discovered in California Gulch. As the placer

deposits were exhausted, underground workings became the principle method for removing gold,

silver, lead, and zinc ore. As these mines were developed, waste rock was excavated along with

the ore and placed near the mine entrances. Ore was crushed and separated into metallic

concentrates at mills, with mill tailing generally slurried into tailing impoundments.

Approximately 17 smelter facilities are reported to have once operated within the Site. Most

operations ceased by about 1900, although some facilities continued to operate into the 1960's. At present, nearly all of the mines within the Site boundaries are inactive; only a few small-to- moderate-sized mining operations exist. All of the mills and smelters which operated onsite are

inactive and/or demolished.

Due to historic mining, milling, and smelting operations, the Site contains many tailings

impoundments, fluvial deposits, slag piles, waste rock piles, and mine water drainage tunnels. Slag on the Site is the mineralized waste byproduct of smelting, and results from the processing

of lead ore in high temperature furnaces. Three major slag piles and several smaller piles remain

at the Site (Figure 2). In 1961, D&RGW purchased the AV Smelter Slag Pile from ASARCO for

use as railroad ballast. D&RGW purchased the La Plata slag pile from the Leadville Sanitation District in 1970. Additionally , D&RGW purchased the Harrison Street Slag Pile from NL Industries in 1983 (EPA, 1996).

The California Gulch Site was placed on the National Priorities List (NPL) in 1983, under the

authority of the Comprehensive Environmental Response, Compensation, and Liability Act

(CERCLA) of 1980. The Site was placed on the NPL because of concerns about the impact of mine drainage on surface waters in the California Gulch and the impact of heavy metals loading

into the Arkansas River (EPA, 1996). Several subsequent investigations were conducted within

the California Gulch Superfund Site that have addressed the slag at the three D&RGW-owned

piles.

In 1986, the EPA's contractor, CH2M Hill, sampled surface water, groundwater, and numerous

mine waste piles, and three D&RGW slag piles as part of the California Gulch Site Remedial Investigation (RI) (EPA, 1989). The objective of the mine waste and slag sampling was to better

characterize the materials in the California Gulch Superfun d Site. Thi s was the first time that the

EPA had sampled slag at the Site.

In 1988, James P. Walsh and Associates, Inc. conducted a Soil s Investigation. The stated

objectives of this study were to define potential action levels for soil, determine background

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metals content of soils, delineate the extent of soil contamination, and determine sources of soil

contamination. This study was initiated by ASARCO, another potentially responsible party

(PRP) at the Site. Three samples of slag were collected as part of this study: one from the Harrison Street pile, one from the La Plata pile, and one from an area west of Leadville. This

study did not include the AV Smelter Slag Pile (MK, 1992).

In May 1989, Jacobs Engineering performed a second sampling of slag for the EPA. The

purpose of the study was to determine the concentrations of metals in the three D&RGW slag

piles and to evaluate the potential for migration of these metals to soil, water or air. Potential

hazards to the environment and public health from the slag in Leadville were evaluated.

On December 3,1991, EPA and D&RGW entered into an Administrative Order on Consent

(AOC), CERCLA - VIII - 92006, for the performance of a remedial investigation/feasibility

study (RI/FS) of the lead slag piles. Prior to the AOC, EPA had studied the slag piles as part of

other investigations at the Site. In 1992, D&RGW performed an RI (MK, 1992) that addressed

seven lead slag piles, including the Arkansas Valley , Harrison, and La Plata slag piles, and one

zinc slag pile. Followin g the RI, a Site-Wide Screening Feasibility Study (SFS) was undertaken

as a joint effort between the PRPs and EPA. The SFS was completed in March 1993. It

screened several remediation alternatives for all types of slag located at the AV Smelter Slag Pile

based on specific criteria, such as relative cost, implementability, and effectiveness. The three

alternatives retained for further evaluation were: no action, institutional controls, and resource

utilization (EPA, 1996).

On December 15,1993, D&RGW entered into a Consent Decree with EPA to perform the

remainder of their site work. The Consent Decree stated EPA's concerns regarding the fine

fraction of the stockpiled slag and the potential for particulate release during ballast operations as

a potential human health exposure pathway. The Consent Decree required D&RGW to perform

a feasibility study for stockpiled fine slag and to submit an operations plan before initiating any

ballast operations. In July of 1995, D&RGW submitted a ballast operations plan to EPA. Followin g EPA's approval of the plan, ballast operations commenced in August 1995 (EPA,

1996).

In May of 1996, D&RGW submitted a feasibility study for the stockpiled fine slag (the FS) at the AV Smelter Slag Pile, according to the terms of the Consent Decree. The existing fine slag

subpile and fine slag potentially generated from future ballast production were the focus of the F S. The FS provided a detailed analysis of the three retained remediation alternatives from the S FS as applied to the stockpiled fine slag. The result of the Feasibility Study for the stockpiled

fine slag was a Proposed No Action Plan for the stockpiled fine slag as a subpile of the AV Smelter Slag Pile (EPA, 1996).

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3 .0 HIGHLIGHTS OF COMMUNITY PARTICIPATION

Public participation is required by CERCLA Sections 113 and 117. These sections require that

before adoption of any plan for remedial action to be undertaken by EPA, the State, or an

individual (PRP), the lead agency shall:

1. Publish a notice and brief analysis of the Proposed Plan and make such plan

available to the public; and

2. Provide a reasonable opportunity for submission of written and oral comments

and an opportunity for a public meeting at or near the Site regarding the Proposed Plan and any proposed findings relating the cleanup standards. The lead agency

shall keep a transcript of the meeting and make such transcript available to the

public. The notice and analysis published under item #1 above shall include

sufficien t information to provide a reasonable explanation of the Proposed Plan

and alternative proposals considered.

Additionally, notice of the final remedial action plan set forth in the ROD must be published, and

the plan must be made available to the public before commencing any remedial action. Such a

final plan must be accompanied by a discussion of any significant changes to the preferred

remedy presented in the Proposed Plan along with the reasons for the changes. A response

(Responsiveness Summary) to each of the significant comments, criticisms, and new data

submitted in written or oral presentations during the public comment period must be included

with the ROD.

EPA has conducted the required community participation activities through presentation of the RI/FS and Proposed Plan, a 30-day public comment period, a formal public hearing, and

presentation of the Selected Remedy in this ROD. However, since the EPA did not receive any

written public comments on the Proposed No Action Plan for the Stockpiled Fine Slag, this ROD

does not contain a Responsiveness Summary.

T he Proposed No Action Plan for Stockpiled Fin e Slag at the AV Smelter Slag Pile was released

for public comment on September 27,1996. The RI/FS and the Proposed No Action Plan were

made available to the public in the Administrative Record located at the EPA Superfund Records

Center in Denver and the Lake County Public Library in Leadville. A formal public comment

period was designated from September 27, through October 28,1996.

On October 3,1996, the EPA hosted a public meeting to present the Proposed Plan for Stockpiled Fine Slag at OU 3 of the California Gulch Superfund Site. The meeting was held at

7:00 pm in the Mining Hall of Fame in Leadville, Colorado. Representatives from the EPA and D&RGW presented the Proposed Plan. Three alternatives were discussed: No Action, Institutional Controls, and Resource Utilization. The No Action alternative was presented as

EPA's and D&RGW's preferred alternative. A portion of the hearing was dedicated to accepting

formal oral comments from the public. Only two questions were raised during this public

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meeting. These questions were in regard to the volume of the fine slag proposed for No Action

and the nature of the soil beneath the Harrison St. slag pile, which is not relevant to this ROD.

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4.0 SCOPE AND ROLE OF OPERABLE UNIT

The California Gulch NPL Site covers a wide area (Figure 2). EPA has established the following OUs for the cleanup of geographically-based areas within the Site. The OUs are designated as:

OU1 Yak Tunnel/Water Treatment Plant O U2 Malta Gulch Fluvial Tailing/Leadville Corporation Mill/Malta Gulch Tailings Impoundments O US D&RGW Slag Piles/Railroad Easement/Railroad Yard and Stockpiled Fine Slag OU4 Upper California Gulch O US ASARCO Smelter/Slag/Mil l Sites O U6 Starr Ditch/Penrose Dump/Stray Horse Gulch/Evans Gulch OU7 Apache Tailing Impoundments OUS Lower California Gulch OU9 Residential Populated Areas OU10 Oregon Gulch OU11 Arkansas River Valley Floodplai n OU12 Site Water Quality

T he purpose of the D&RGW Slag Piles/Railroad Easement/Railroad Yard OU RI/FS was to

gather sufficien t information to support an informed risk management decision on which

remedies are the most appropriate for the D&RGW Stockpiled Fine Slag portion of OUS. The RI/FS was performed in accordance with the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 Code of Federal Regulations (CFR) Part 300, and CERCLA Section 104,42 U.S.C. § 9604.

The objectives of the RI/FS were to:

• Determine the nature and extent of metals in source areas and other affected areas within

the D&RGW Slag Piles/Railroad Easement/Railroad Yard OU;

• Define the potential pathways along which metals can migrate, as well as the physical

processes and, to the extent necessary, the chemical processes that control these

pathways;

• Determine risk assessment information including potential receptors, exposure patterns,

and food chain relationships; and

• Develop, screen, and evaluate remedial alternatives and predict the consequences of each

remedy.

Based on the findings of previous investigations and the results of the D&RGW Slag Piles/Railroad Easement/Railroad Yard OU RI/FS, the sources and areas of environmental

contamination at the Stockpiled Fine Slag (AV Smelter Slag Pile) portion of OUS have been

adequately delineated.

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The remedy outlined in this ROD represents the final remedial action only for the stockpiled fine

slag at the AV Smelter Slag Pile. Remedial actions undertaken at the Stockpiled Fine Slag

portion of OU3 are intended to be consistent with the remedial action objectives and goals

identified for the California Gulch NPL Site and other OU investigations.

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Stockpiled Fin e Slag (OU 3) DS-8
5 .0 SUMMARY OF SITE CHARACTERISTICS

As a result of D&RGW processing the slag for use as railroad track ballast, the AV Smelter Slag Pile is actually composed of several sub-piles (Figure 3). The subpiles of the AV Smelter Slag Pile site include sorted fines, water-quenched fines, ballast-sized material, oversized material,

and unsorted air-cooled slag. The subpiles of sorted fines consist of the less than 3/8 inch

diameter slag. The ballast-sized subpile is composed of material with particle sizes ranging from

approximately 3/8 inch to 2-1/2 inches in diameter. Two subpiles of oversized material from

ballast processing consist of slag that is greater than 2-1/2 inches in diameter, some brick, and

some scrap iron. The existing fines piles and fines potentially generated from future ballast

production are the focus of this ROD. Figure 3 also depicts the location of stockpiled fine slag at

the AV Smelter Slag Pile. This and a small amount of fine slag in the railyard are the only

locations within the California Gulch Superfund Site with stockpiled fine slag. The volume of

stockpiled fine slag at the AV Smelter Slag Pile is approximately 190,000 cubic yards. The

volume of stockpiled fine slag at the railyard was estimated at approximately 220 cubic yards

(Terranext, 1996b). As noted previously, the small amount of fine slag at the railyard has been

moved to the AV Smelter Slag Pile. The total volume of fine slag moved from the railyard to the AV Smelter Slag Pile was approximately 1200 cubic yards.

The following paragraphs discuss the primary contaminants of concern, summarize the nature

and extent of contamination, and provide a brief description of contaminant fate and transport.

Site Characterization Summary - Stockpiled Fin e Slag

During the Lead Slag Pile RI (MK, 1992) a total of 18 slag samples were collected from the AV Smelter Slag Pile (Figure 4). Four of these samples were collected from the sorted fines and four

from the water-quenched fines subpiles. These samples were collected from the surface to a

depth of 3 feet. In addition, four subslag samples were collected from four coreholes drilled at

the AV Smelter Slag Pile. Two of these subslag samples were collected from directly below the

water-quenched fines subpile. Each sample was submitted for laboratory compositional and

teachability analysis. Material from the finer-grained slag piles was also submitted for particle

size testing. Compositional analyses included total metals, water-soluble anions, and acid-base

accounting. Leachability testing included Synthetic Precipitation Leaching Procedure (SPLP)

(EPA Method 1312) and column leach tests, which were intended to simulate, as closely as

possible, in situ conditions (Terranext, 1996a).

Compositional results showed that the slag is an iron magnesium silicate, with residual base

metals. Concentration means for the four primary metals of concern collected from fine slag

sample locations at the Site are as follows:

• Arsenic means; 435 milligram per kilogram (mg/kg) -sorted fines, 909 mg/kg

water quenched fines

• Cadmium means; 11.9 mg/kg-sorted fines, 16.6 mg/kg water-quenched fines

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• Lead means; 10,800 mg/kg-sorted fines, 9,650 mg/kg water-quenched fines

• Zinc means; 44,000 mg/kg-sorted fines, 73,000 mg/kg water-quenched fines

Compositional results for the two subslag soil samples (AVB103 and ABV104) collected

beneath the water-quenched fines showed concentrations of metals of concern to be significantly

lower than those for the slag material, and within the range of literature values for metals

occurring naturally in soil (MK, 1992-Table 4-15). These samples showed the lowest value for

arsenic (5.7 mg/kg), lead (84.8 mg/kg) and for zinc (188 mg/kg) from all subslag soil samples

collected. Site-specific background has not been established, however, ranges for metals of

concern in Colorado soils are as follows: arsenic (1.2-24 mg/kg), lead 15-150 mg/kg) and zinc

(16-300 mg/kg) (Terranext, 1996a). The subslag soil samples collected from beneath the waterquenched fine slag at AV exhibited a negative acid-forming potential.

Leaching analysis, which included both SPLP and column leach studies, showed minimal

leaching of metals of concern. Synthetic Precipitation Leaching Procedure results for all

elements tested in slag were below the toxicity characteristic criteria, listed in 40 CFR 261.24. Mean values for the contaminants of concern were generally two orders of magnitude lower than

these regulatory thresholds. Column leach tests showed similar low levels of leaching

(Terranext, 1996a).

Particle size data and site-specific meteorological data were used to determine whether slag in

the fine-grained piles has the ability to become airborne. Threshold friction velocities (the wind

speed above which the surface material becomes airborne) were calculated using the mode of the

aggregate size distribution. Wind data and the height of the piles were used to calculate the

friction velocity. Results for the two fines piles are:

Threshold Friction Velocity

sorted fines 1.0 meters per second (m/sec)

water-quenched fines 0.58 m/sec Friction Velocity 0.55 m/sec

A friction velocity lower than the threshold friction velocity demonstrates that sustained wind

gusts (0.55 m/sec, MK 1992) in Leadville are not fast enough to cause wind erosion of the fines

slag piles.

Groundwater

A site-wide monitoring program will be developed at the California Gulch Superfund Site once

all source areas have been addressed. Groundwater in the vicinity of the stockpiled fin e slag has

not been full y characterized. As noted above, the subslag material showed concentrations of

metals of concern to be significantly lower than those for the slag material, and within the range

of literature values for metals occurring naturally in soils. These results suggest that surface

water infiltration through the slag piles does not significantly impact groundwater nor does it

impact the soils beneath the slag piles, as evidenced by the results of the soil analyses (Terranext,

1996a).

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Surface Water

No discreet conveyances of surface water runoff from the AV area have been noted. Additionally, the berm placed along the California Gulch is designed to eliminate surface water

runoff from directly entering the California Gulch (Terranext, 1996a).

Soil s

«• Analysis of subslag soils from beneath the fine slag piles show the lowest concentration for lead,

arsenic and zinc of any of the subslag samples collected (Terranext, 1996a).

Discussion of Fate and Transport

Existing pathways for potential migration of metals of concern include wind, leaching, mixing by

human activities, runoff, and direct contact.

Release Mechanism 1 - Wind

The air pathway analysis results indicate that wind erosion is not a viable release mechanism for

the lead slag piles, including the AV water-quenched and sorted fines piles.

Release Mechanism 2 - Leaching

Testing in subslag material does not indicate that leachate from slag contributes to elevated

metals concentrations in the vadose zone beneath the slag piles. This conclusion is supported by

the lack of acid-generating potential and the neutral-to-basic pH of the slag and subslag

materials.

Release Mechanism 3 - Mixin g by Human Activities

Transport of slag by human activities has occurred, as it was historically used for road

maintenance within the Site by Lake County and the Colorado Department of Transportation. This mechanism will not continue in the future as reuse of the slag material is controlled as

specified in this ROD.

Release Mechanism 4 - Surface Water Runof f

No evidence of transport of slag fines by surface water runoff was observed at any of the

examined piles. Slag does not appear to be transported from piles onto adjacent soils in rivulets

or channels. Pile integrity, especially for fines piles where this is most critical, appears intact. This potential release mechanism for slag is not a concern at the AV Smelter Slag Pile.

Record of Decision Stockpiled Fine Slag (OU 3) S1298P:\3280-OI4\FINALROD\OU3ROD2.WPD
Release Mechanism 5 - Direct Contact

Due to the physical characteristics of the slag piles, direct contact with the slag piles was

considered unlikely in EPA's Preliminary Baseline Human Health Risk Assessment (EPA 1991). Therefore, it was eliminated as a release mechanism.

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6.0 SUMMARY OF SITE RISKS

In the Preliminary Baseline Human Health Risk Assessment (EPA, 1991) lead and arsenic were

identified as the primary chemicals of potential concern at the California Gulch NPL Site. Since

the completion of the preliminary risk assessment, several important studies were completed that

provided more extensive and more reliable data on environmental concentrations and on human

and ecological exposures. Leadville official s and business leaders expressed concern over

possible risks and liabilities associated with commercial and recreational uses within the Site. Therefore, in the final baseline risk assessment, risks posed by environmental contamination to

current or future workers in the commercial and business district of the community and to people

who engage in recreational activities in and around the community were evaluated. The

assessment was conducted to determine if environmental contamination was of concern at any

locations presently zoned commercial/industrial and to address concerns regarding the

development of a proposed bike path around the community (EPA, 1996).

In 1995, EPA completed two parts of the Baseline Human Health Risk Assessments for the California Gulch Superfund Site. These are: Part A Risks to Residents from Lead (EPA,

1995b), and Part C Evaluation of Recreational, Worker Scenarios (EPA, 1995c). Part A

evaluates risks to residents from lead; and Part C evaluates risks to workers in the commercial

and business district and to recreational users in areas in and around the community. The

followin g paragraphs summarize results of the final baseline risk assessment as they relate to the

stockpiled fine slag at the AV Smelter Slag Pile.

Terrestrial and aquatic risks associated with exposure to site chemicals were also evaluated by

EPA. Aquatic risks were evaluated in the Final Baseline Aquatic Ecological Risk Assessment

(EPA, 1995d) and terrestrial risks were evaluated in the Ecological Risk Assessment for the Terrestrial Ecosystem (EPA, 1997).

6 .1 RESIDENTIAL EXPOSURE TO SLAG

The evaluation of exposure to contaminants at waste piles included consideration of slag pile

data, with an exposure scenario conservatively evaluating a child playin g on the waste piles who

may come in contact with contaminants through inadvertent ingestion or dermal (skin) contact. The dermal contact pathway was determined to be minimal and was not considered further. The

residential risk assessment also determined that non-lead metals in most waste piles pose either

no risk or only low risk from direct contact while playing on the piles. For the evaluation of lead

exposure at the waste piles, the data were found to be too limited to derive reliable estimates of

the potential impact of direct exposures to children who play on waste piles. Therefore a

quantitative evaluation was not performed. As stated in the preliminary risk assessment and the SFS, direct contact of residents with the slag piles is not expected to occur.

Wind erosion and direct contact were not considered viable release mechanisms for the

stockpiled fine slag. However, based on the results of the risk assessment, there is some concern

about the potential for paniculate release and human exposure should resource utilization of the

stockpiled fine slag be undertaken. For example, inhalation of slag particles could occur if the

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material is disturbed from its current state. If the resource utilization option is exercised,

measures would be required to prevent contaminant releases.

6 .2 RESIDENTIAL EXPOSURE TO IMPACTED GROUNDWATER

The remedial action objective in the 1993 SFS was to prevent leaching of metals of concern in

concentrations that would have an adverse impact on soils, surface water, or groundwater in the

area near the slag piles. The 1996 FS determined that testing of material under the slag pile did

not indicate that migration of contaminants by leaching from the slag contributes to elevated

metals beneath the slag piles. In addition, the final baseline risk assessment determined that

groundwater from this aquifer is not currently used for drinking, and it is relatively unlikely that

it will be used for drinking in the future. It has been determined that there is a minimal potential

for release of metals in leachate from the stockpiled fine slag, and that the stockpiled fine slag

poses an insignificant impact on water quality (EPA, 1996).

63 RECREATIONAL USER EXPOSURE TO SLAG

The AV Smelter Slag Pile area is situated in an area presently zoned as industrial/mining and is

not considered a recreational use area, thus, there is no complete exposure pathway.

6 .4 WORKER EXPOSURE TO SLAG

There are no current worker exposure pathways to the stockpiled fin e slag. The Selected Remedy provides a contingency for resource utilization, which may be undertaken in the future. T he EPA has determined that resource utilization of the stockpiled fin e slag is only appropriate if

it is encapsulated for reuse, to deter the potential release of airborne particulates and eliminate

potential risk associated with resource utilization activities. Encapsulation can include the use of

fin e slag in concrete or asphalt aggregate; or as road base, backfil l or other construction material

as long as the fin e slag is chemically bound or physically separated from any exposure scenario

by a barrier consisting of another material. Dust suppressants to control particulate emissions

and best management practices to control stormwater runoff would also be employed to contain

contaminant releases during implementation of the contingency remedy.

In response to concerns raised by Leadville official s and business leaders over potential liability

associated with business development within a Superfun d Site, EPA developed action levels to

determine if chemical concentrations were of concern at any locations presently zoned for

commercial and industrial purposes. Action levels were developed only for arsenic and lead, the

contaminants of most concern at the Site. The action levels were developed only for soil and

dust ingestion; exposure to other media (e.g., slag piles, waste piles) and exposure to soil/dus t via

other pathways (e.g., dermal) are considered of insignificant concern for workers.

The soil action level for lead based on commercial/industrial exposure to soil and dust ranged

from as low as 2,200 parts per million (ppm) to as high as 19,100 ppm with central tendency

values in the 6,100 to 7,700 ppm range. Lead concentrations in soils in and around the slag piles

(maximum lead concentration of 794 ppm) were well below the lead action level (EPA 1996).

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Soil action levels for arsenic based on commercial/industrial exposure to soil and dust ranged

from as low as 330 ppm to as high as 1,300 ppm, with central tendency values in the 610 to 690

ppm range. Arsenic concentrations in soils in and around the slag piles (maximum arsenic

concentration of 5.7 ppm) were well below the lowest arsenic action level.

6 .5 ENVIRONMENTAL EXPOSURE TO SLAG

6.5.1 AQUATIC EXPOSURE

There are no aquatic exposure pathways to stockpiled fine slag due to the lack of release

mechanisms. No evidence of transport of slag fines by surface water runoff was observed at any

of the examined piles. Slag does not appear to be transported from piles onto adjacent soils in

rivulets or channels. Pile integrity, especially for fines piles where this is most critical, appears

intact. Surface water runoff is not a potential release mechanism for the AV Smelter Slag Pile. Additionally , air pathway analysis results indicate that wind erosion is not a viable release

mechanism for the lead slag piles, including the AV water-quenched and sorted fines piles. Leaching to groundwater is also not a potential release mechanism. Testing in subslag material

indicates that leachate from slag does not contribute to elevated metals concentrations in the

vadose zone beneath the slag piles. This conclusion is supported by the lack of acid-generating

potential and the neutral-to-basic pH of the slag and subslag materials.

6.5.2 TERRESTRIAL EXPOSURE

Terrestrial exposure pathways to the stockpiled fine slag are unlikely to be significant. The slag

piles do not offer any viable habitat or sustenance for terrestrial receptors. Although terrestrial

receptors (i.e., birds, mammals) could access the slag piles, there is no habitat or food source to

attract these receptors. As stated above, wind erosion, leaching, and surface water runoff are not

considered potential release mechanisms for the slag piles , which considerably reduces the

potential for terrestrial receptors to contact slag in more attractive environs.

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7.0 DESCRIPTION OF ALTERNATIVES

A brief description of the three alternatives evaluated in the Stockpiled Fine Slag FS for the AV

Smelter Slag Pile (Terranext, 1996a) is provided below. All alternatives presented in the FS

were evaluated against the nine criteria described in the next section, and then compared with

each of the other options.

Alternative 1; No Action

This alternative leaves the stockpiled fine slag in place with no remediation, engineering or

institutional controls, or long-term maintenance. Generally, the No Action Alternative is

provided for consideration as a baseline against which other technologies can be compared, in

accordance with the NCP. No Action is protective of human health and the environment, and is

considered effective because no complete human or ecological exposure pathways were

identified. However, a site-wide surface and groundwater monitoring program will be developed

once all source areas have been addressed. Monitoring will continue until EPA determines that

such monitoring is no longer necessary to ensure that human health and the environment are

protected. D&RGW would conduct any required monitoring at the stockpiled fine slag pile^o

ensure that it poses no threat to human health or the environment. This alternative is technically

feasible and cost-effective, since it does not rely on any technology and has no cost (EPA, 1996).

Alternative 2; Institutional Controls

Institutional controls involve restricting access or activities that could result in human contact

with the slag or increase the potential for leaching from stockpiled fin e slag. Controls include

fencing, land-use restrictions, or deed restrictions. Additionally , community awareness programs

could be implemented to alert the community to any physical^ hazards associated with the fine

slag. Controls could be implemented separately or in combination. The option considered is to

fence and maintain the stockpiled fin e slag located at the AV Smelter Slag Pile, Fencing would

eliminate the potential direct contact pathway with the fin e slag piles, would be protective of

human health and the environment because no complete human or ecological exposure pathways

would exist (that is, children would not have access to the piles), and potential for release of

metals in leachate from the stockpiled fin e slag would remain minimal. Fencing would also be

technically feasible. Costs associated with fencing are $163,970 with inspection and

maintenance costs of $8,443 for a 30-year period (EPA, 1996).

Alternatives; Resource Utilization

The utilization of stockpiled fine slag as a resource could involve a number of activities and/or

processes. At present, although options have been identified, it is not possible to ascertain if or

when the entire volume of stockpiled fine slag could be reused. Two options for the resource

utilization (materials reuse) were identified iirthe FS: 1) to process the slag as aggregate for

asphalt or concrete, 2) to use slag materials for stand-alone material in construction, such as

backfill for roadbase material or pipe bedding.

Record of Decision Stockpiled Fine Slag (OU 3) S129gP:\328<WI4\FINALROD\OU3ROD2.WPD
Resource utilization would be protective of human health and the environment because

appropriate environmental controls for particulates emissions and storm water runoff would be

required to control contaminant releases. Consideration must also be given to any toxic leaching

potential for the fine slag. Resource utilization may marginally decrease the minimal metals

concentrations in the stockpiled fine slag leachate through overall volume reduction. However,

the effectiveness and implementability of this alternative would be affected by the regional

market demand for the material. Effort s conducted to identify markets have been unsuccessful to

date, but a potential for future markets exists. Therefore, the EPA has determined that this

alternative should be included as a contingency with "No Action" as the preferred alternative

(EPA, 1996). However, resource utilization of the stockpiled fine slag is only appropriate if it is

encapsulated prior to its use or reuse. Cost effectiveness is hindered by the distance the slag material is located from a major market and the cost associated with sorting the slag. Cost for

use of the fine slag as aggregate is estimated as a $1,120,000 loss after resale, while the cost for

use as fill material is estimated as a $244,625 loss after resale (EPA, 1996).

Record of Decision Stockpiled Hne Slag (OU 3) SI298P:\3280-OU\nNALROD\OU3ROD2.WPD
8 .0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES

Section 300.430(e)(9) of the NCP requires that the agencies evaluate and compare the remedial

cleanup alternatives based on the nine criteria listed below. The first two criteria, (1) overall

protection of human health and the environment and (2) compliance with applicable or relevant

and appropriate requirements (ARARs) in Appendix A, are threshold criteria that must be met

for the Selected Remedy. The Selected Remedy must then represent the best balance of the

remaining primary balancing and modifying criteria.

8 .1 EVALUATION AND COMPARISON CRITERIA

8.1.1 THRESHOLD CRITERIA

1. Overall protection of human health and the environment addresses whether or not a

remedy provides adequate protection and describes how potential risks posed through

each pathway are eliminated, reduced, or controlled through treatment, engineering

controls, or Institutional Controls.

2. Compliance with ARARs addresses whether or not a remedy will comply with identified

federal and state environmental and siting laws and regulations.

8.1.2 PRIMARY BALANCING CRITERIA

3. Long-term effectivenes s and permanence refers to the ability of a remedy to maintain

reliable protection of human health and the environment over time.

4. Reduction of toxicity. mobility and volume through treatment refers to the degree that the

remedy reduces toxicity, mobility, and volume of the contamination.

5. Short-term effectivenes s addresses the period of time needed to complete the remedy and

any adverse impact on human health and the environment that may be posed during the

construction and implementation period until cleanup goals are achieved.

6. Implementabilit y refers to the technical and administrative feasibilities of a remedy,

including the availability of materials and services needed to carry out a particular option.

7. Cost evaluates the estimated capital costs, operation and maintenance costs, and present

worth costs of each alternative.

8.1.3 MODIFYING CRITERIA

8. State acceptance indicates whether the State (CDPHE) , based on its review of the

information, concurs with, opposes, or has no comment on the preferred alternative.

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9. Community acceptance is based on whether community concerns are addressed by the Selected Remedy and whether or not the community has a preference for a remedy.

8 .2 EVALUATING THE STOCKPILED FINE SLAG ALTERNATIVES

The following is a brief summary of the agencies evaluation and comparison of stockpiled fine

slag alternatives. Additional details evaluating the alternatives are presented in the FS. This

section evaluates the performance of the stockpiled fine slag alternatives against the nine criteria

discussed above, and compares it with the other possible options. Information for this section

w as obtained from the Final Stockpiled Fine Slag FS (Terranext, 1996a).

8.2.1 OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT

This criterion is based on the level of protection of human health and the environment afforded

by each alternative. All of the alternatives are protective of human health. No complete human

or ecological exposure pathways have been identified. Based upon the chemical composition of

the slag and soil sampling conducted beneath the slag, the potential for release of metals in

leachate from the stockpiled fine slag is minimal. The stockpiled fine slag has, at most,

insignificant non-point source impact on water quality.

The physical features of the slag piles have remained relatively unchanged for many decades. That fact, combined with the determination that the only potential release pathway is through

leachate, suggests that the status of the slag is not likely to change in the near or long term. Therefore all three alternatives are protective of human health and the environment.

8.2.2 COMPLIANC E WITH APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENT S (ARARs)

This criterion is based on compliance with chemical-, location-, and action-specific ARARs. ARARs are presented in Appendix A. All of the alternatives meet ARARs. Groundwater quality

is a function of the active interchange with surface water degraded by the release of more mobile

metal species from the multitude of other contaminant sources in the vicinity. The potential for

non-point source metals loading to surface water from stockpiled fin e slag leachate is minimal to

nonexistent. The use of institutional controls on the stockpiled fine slag will not have any effect

on groundwater quality. Non-point source, Best Management Practices (BMP) to-be-considered

criteria have been implemented along the slag piles contacting California Gulch.

8.23 LONG-TERM EFFECTIVENESS AND PERMANENCE

This criterion is based on the magnitude of residual risk and adequacy and reliability of controls. No Action is an effective long-term alternative. The only identified release pathway determined

to have any potential to contribute to human or environmental risks is the potential for metals to

leach from the stockpiled fine slag. Based upon subslag sampling, metals have not leached and

will not leach from the stockpiled fin e slag in concentrations that will have an adverse impact on

soils, surface water or groundwater in the vicinity. Based upon the hardness of the slag, the lack

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of acid-generating potential and the absence of significant metals in soils beneath the slag, the

potential for exposure to metals of concern found in the slag is unlikely to change in the long

term. Institutional controls can be effective in the long term, but are not permanent. Fencing

requires inspections, maintenance and community awareness, and must be renewed or replaced

periodically. Resource utilization represents a reliable alternative which uses known

technologies, limited only by the regional market demand for the stockpiled fine slag. Resource

utilization will not have a dramatic effect on the residual risk, as the pre-resource utilization risks

are minimal.

8.2.4 REDUCTION OF TOXICITY, MOBILITY, OR VOLUME THROUGH TREATMENT

This criterion is based on the treatment process used; the amount of contamination destroyed or

treated; the reduction of toxicity, mobility, and volume; the irreversible nature of the treatment;

the type and quantity of residuals remaining; and the statutory preference for treatment.

Institution controls and No Action do not further reduce the very limited toxicity or mobility of metals of concern in the stockpiled fine slag. In the absence of complete exposure pathways,

there is no indication that toxicity and mobility of hazardous substances in the slag pose a human

health risk. From a land-use perspective, the slag volume is not an issue as tourists come

specifically to observe historic mining practices. Implementation of institutional controls or the No Action alternative, however, will not reduce the volume of the fine slag found at the site.

Over time, reuse could reduce the very limited potential toxicity and potential mobility of the

stockpiled fine slag. From a land-use perspective, the change in the total volume of all types of

slag will not be significant if only the stockpiled fine slag is utilized.

8.2.5 SHORT-TERM EFFECTIVENESS

This criterion is based on the degree of community and worker protection offered, the potential

environmental impacts of the remediation, and the time until the remedial action is completed. No action and institutional controls do not create additional risk to the Leadville community

during implementation. For institutional controls, workers and the community can be adequately

and reliability protected if fencing were to be installed.

Resource utilization can also be implemented with no additional risk to the Leadville

community. Workers and the community can be adequately and reliably protected from fugitive

particulates and changes in storm-water drainage when the stockpiled fine slag is utilized.

8.2.6 IMPLEMENTABILITY

This criterion is based on the ability to perform construction and implement administrative

actions. No Action is technically feasible as it does not rely on any technology. As the status

quo, no action is implementable.

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Institutional controls are technically feasible, as reliable fencing can be procured and installed

readily by local contractors. Land-use restrictions would require action by either the Lake County Commissioners or the Leadville Town Council. Therefore, because further action is

needed by a third party, the potential of implementability of land-use restrictions cannot be

predicted.

Resource utilization is also technically feasible but there are unknowns as to the marketability of

the resource. Demand for the stockpiled fine slag will be dependant on a number of factors,

including but not limited to, the level of construction activity in the vicinity of Leadville.

8.2.7 COST

Alternative 1: No Action

As there are no costs associated with No Action, it is the most cost effective alternative.

Alternative 2: Institutional Controls

Institutional controls involve fencing and maintenance of the stockpiled fine slag located at the AV Smelter Slag Pile. Fencing the AV pile would have present value capital and labor costs of

$161,000 and inspection and maintenance costs of $8,500 to inspect and maintain over a 30-year

period indicated in the summary in Table 1.

Alternative 3: Resource Utilizatio n

Resource utilization does not presently appear to be a cost-effective option even if market

demands for the material are identified. Effort s conducted to identif y markets have been

unsuccessful to date. The options considered are 1) to process slag for use as a concrete or

asphalt aggregate in construction, and 2) to utilize slag materials for a stand-alone material in

construction, such as a backfill or pipe bedding.

The cost effectiveness of these options is hindered by the distance the slag material is located

from a major market and the cost associated with sorting the slag. Cost estimates and a cost

summary are included in Table 1. Estimates have been provided for use of the fine slag for

aggregate ($1,120,000 loss after resale) and for use in fill material ($244,625 loss after resale).

8.2.8 STATE ACCEPTANCE

The State has been consulted throughout this process and concurs with the Selected Remedy.

8.2.9 COMMUNITY ACCEPTANC E

Public comment on the RI/FS and Proposed Plan was solicited during a formal public comment

period extending from September 27 to October 28,1996. It is assumed that the community is

generally supportive of EPA's No Action alternative since no comments were generated during

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the formal public comment period. In addition, only two oral comments were raised during the

public meeting held October 3,1996. These comments were in regard to the volume of the fine

slag pile and the nature of the soil beneath the Harrison St. slag pile, which is not relevant to this ROD.

8.2.10 SUMMARY

The FS used a comparative analysis to qualitatively evaluate the performance of each alternative

in relation to each specific evaluation criterion. The purpose of this comparative analysis is to

identify the advantages and disadvantages of each alternative relative to one another so that key

tradeoff s could be identified.

A grid comparison method was used to rank the alternatives and their attainment relative to the NCP criteria set forth in the SFS. Alternatives were ranked on a scale of 1 to 5, with 5 being the

highest attainment of the criterion. Total scores for each alternative were: Alternative 1: No Action at 41; Alternative 2: Institutional Controls at 3 9; and Alternatives: Resource Utilization

at 36. Table 2 provides a grid comparison method to rank the alternatives and their attainment

relative to the followin g criteria.

• Protection of Human Health and the Environment - All three alternatives are protective of

human health and the environment.

• Attainment of ARARs - All three alternatives attain ARARs. • Long-Term Effectivenes s - All three alternatives have similar long-term effectiveness. Reuse of the stockpiled fine slag would marginally reduce the residual risk because of

volume reduction. None of the alternatives are subject to technology failure from age or

wear and tear.

• Reduction of Toxicity , Mobility or Volume - None of the three alternatives reduce the

toxicity and mobility of metals of concern found in the fine slag.

• Short-Term Effectivenes s - All three alternatives can be implemented in a manner which

protects the Leadville community and the workers implementing the remedy. The No Action alternative eliminates disturbances of the fine grain slag and requires no workers.

• Implementability - All three alternatives are implementable. Deed restrictions are in

effect . Land use restrictions may not be implementable from and administrative

perspective as they require approval by the Lake County Commissioners. Reuse requires

that there be a commercial market or internal need for the stockpiled fine slag which, at

this time, is uncertain.

• Cost - No Action is the most cost-effective approach to meeting the remedial action

objectives and attaining ARARs. There are essentially no costs associated with this

remedial option.

• State Acceptance - CDPHE has been consulted throughout the RI/FS process.

• Community Acceptance - The community has been consulted throughout the RI/FS

process.

Selection of the No Action alternative was based on this analysis.

Record of Decision Stockpiled Fin e Slag (OU 3)

5I29SP:\328<M>U\FINALROD\OU3ROD2.WPD
9.0 SELECTED REMEDY

Based upon consideration of CERCLA requirements, the detailed analysis of alternatives, and

public comments, EPA has determined that the No Action alternative presented in the Proposed Plan, with no modifications, is the appropriate remedy for the stockpiled fine slag at the AV Smelter Slag Pile of OU3 within the California Gulch Superfund Site. The No Action alternative

leaves the stockpiled fine slag in its existing condition with no control or cleanup planned. The No Action alternative, as described in the Proposed Plan, includes a contingency for future

utilization of the slag, if it is encapsulated prior to its use or reuse.

The No Action alternative is protective of human health and the environment, and is considered

effective because no complete human or ecological exposure pathways were identified and

because the potential for release of metals in leachate is minimal. Based on subslag sampling, metals have not leached and will not leach from the stockpiled fine slag in concentrations that

will have an adverse impact on soils, surface water, or groundwater in the area. Slag hardness,

the lack of acid-generating potential, and the absence of any significant metals beneath the slag

also indicate that the potential for exposure to metals of concern found in the slag is unlikely to

change in the long term. Thi s alternative is technically feasible and cost effective, since it does

not rely on any technology and has no cost.

Resource utilization would only implemented if future regional market demand exists for the

material. Encapsulation of the fine slag ensures that the contingency remedy is also protective of

human health and the environment. Encapsulation can include the use of the fine slag in

concrete or asphalt aggregate; or as road base, backfil l or other construction material as long as

the fine slag is chemically bound or physically separated from any exposure scenario by a barrier

consisting of another material. Dust suppressants to control paniculate emissions and best

management practices to control stormwater runoff would also be employed to contain

contaminant releases during implementation of the contingency remedy.

Record of Decision Stockpiled Fin e Slag (OU 3)

5I298P:\3280-OI4\FINALROD\OU3ROD2.WPD
10.0 STATUTORY DETERMINATIONS

Under CERCLA Section 121, EPA must select a remedy that is protective of human health and

the environment; that complies with ARARs; is cost effective; and utilizes permanent solutions,

and alternative treatment technologies, or resource recovery technologies to the maximum extent

practicable. In addition, CERCLA includes a preference for remedies that include treatment

which permanently and significantly reduces the volume, toxicity, or mobility of hazardous

wastes as a principal element. However, the Selected Remedy, No Action, does not satisfy the

statutory preference for treatment as a principal element of the remedy. Treatment was

considered unnecessary as the Selected Remedy is protective of human health and the

environment. The followin g sections discuss how the Selected Remedy meets statutory

requirements.

10.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMEN T

The selected remedy is protective of human health and the environment because 1) no complete

human or ecological exposure pathways were identified and 2) metals have not leached and will

not leach from the stockpiled fine slag that will have an adverse impact on soils, surface water or

groundwater in the area.

• Because the estimated action levels for recreational land-use scenarios are significantly above

current surficial soil concentrations for both lead and arsenic, there appears to be relatively little

uncertainty in the conclusion that current surface soils do not pose unacceptable risk levels to

recreational site visitors anywhere within the OU boundaries (EPA, 1995b). In addition, the AV

Smelter Slag Pile area is situated in an area presently zoned as industrial/mining and is not

considered a recreational use area (EPA, 1996).

There are no current worker exposure pathways to the stockpiled fin e slag. The Selected Remedy provides a contingency for resource utilization, which may be undertaken in the future. T he EPA has determined that resource utilization of the stockpiled fin e slag is only appropriate if

it is encapsulated prior to its use or reuse, to deter the potential release of airborne particulates

and eliminate potential risk associated with resource utilization activities. Dust suppressants to

control particulate emissions and best management practices to control stormwater runoff would

also be employed to contain contaminant releases during implementation of the contingency

remedy.

The soil action level for lead based on commercial/industrial exposure to soil and dust ranged

from as low as 2,200 parts per million (ppm) to as high as 19,100 ppm with central tendency

values in the 6,100 to 7,700 ppm range. Lead concentrations in soils in and around the slag piles

(maximum lead concentration of 794 ppm) were well below the lead action level (EPA 1996).

Soi l action levels for arsenic based on commercial/industrial exposure to soil and dust ranged

from as low as 330 ppm to as high as 1,300 ppm, with central tendency values in the 610 to 690

ppm range. Arsenic concentrations in soils in and around the slag piles (maximum arsenic

concentration of 5.7 mg/kg) were well below the lowest arsenic action level.

Record of Decision Stockpiled Fin e Slag (OU 3)

5129SP:\3280-OI 4\FINALROD\OU3ROD2.WPD
10.2 COMPLIANC E WITH ARARs

The Selected Remedy will comply with all ARARs identified in Appendix A to this ROD. No

waiver of ARARs is expected to be necessary.

10.3 COST EFFECTIVENESS

Section 300.430(f)(ii)(D) of the NCP requires evaluation of cost effectiveness. The Selected Remedy is cost effective because it has no cost.

10.4 UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT TECHNOLOGIES (OR RESOURCE RECOVERY

TECHNOLOGIES ! T O THE MAXIMUM EXTEN T POSSIBL E

No remedial action is necessary to ensure protection of human health and the environment. The

contingency allows for resource recovery if supported by regional market demand.

10.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT

Treatment of the stockpiled fin e slag at the AV Smelter Slag Pile was not considered because the No Action alternative is protective of human health and the environment.

Record of Decision Stockpiled Fine Slag (OU 3)

5IW8P:\3280-OI4\FINALROD\OU3ROD2.WPD
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES

T he Proposed Plan for stockpiled fine slag at the AV Smelter Slag Pile was released for public

comment in September 1996. The Proposed Plan identified Alternative 1, No Action, as the

preferred alternative, with the contingency that resource utilization may be undertaken in the

future. Resource utilization of the stockpiled fine slag would only be appropriate if it is

encapsulated prior to its use or reuse. No comments were received during the public comment

period. Subsequently, EPA determined that no significant changes to the remedy, as it was

originally identified in the Proposed Plan, were necessary.

Record of Decision Stockpiled Fin e Slag (OU 3)

51298P:\3280-01 -(\FINALROD\OU3ROD2.WPD
12.0 REFERENCES

Morrison Knudsen Corporation (MK). 1992. Report for Lead Slag Pile Remedial Investigation

at the California Gulch Site Leadville, Colorado, prepared for Denver & Rio Grande Western Railroad. December 11.

Terranext. 1996a. Final Stockpiled Fine Slag Feasibility Study, prepared for Denver & Rio Grande Western Railroad. May 13.

Terranext. 1996b. Work Plan Consolidation of Fine Slag. Prepared for Denver & Rio Grande Western Railroad. November. 12.

U.S. Department of Commerce. 1990. Selected Population and Housing Characteristics. Bureau of the Census.

U.S. Environmental Protection Agency (EPA). 1997. Ecological Risk Assessment for the Terrestrial Ecosystem. California Gulch NPL Superfund Site, Leadville, Colorado. Prepared by Roy F. Weston, Inc., January, 1997.

U.S. Environmental Protection Agency (EPA). 1996. Proposed No Action Plan for Stockpiled Fine Slag, Arkansas Valley Smelter Slag Pile, California Gulch Superfun d Site, Leadville, Colorado. September.

U.S. Environmental Protection Agency (EPA). 1995a. Draft Final Findings of Metal Speciation Investigations at the California Gulch NPL Site, Prepared by John W. Drexler and Roy F. Weston, Inc., October 1995.

U.S. Environmental Protection Agency (EPA). 1995b. Baseline Human Health Risk Assessment for the California Gulch Superfun d Site - Part A - Risks to Residents from lead

prepared by Roy F. Weston, Inc., Draft final November 6,1995.

U.S. Environmental Protection Agency (EPA). 1995c. Baseline Human Health Risk Assessment for the California Gulch Superfun d Site - Part C - Evaluation of Recreational and Worker Scenarios prepared by Roy F. Weston, Inc., April 17,1995.

U.S. Environmental Protection Agency (EPA). 1995d. Final Baseline Aquatic Ecological Risk Assessment. California Gulch NPL Site. Prepared by Roy F. Weston, Inc., September, 1995.

U.S. Environmental Protection Agency (EPA). 1991. Preliminary Human Health Baseline Risk Assessment for the California Gulch NPL Site, Leadville, Colorado. Prepared by Roy F. Weston, Inc. for the U.S. EPA, December 1991.

Record of Decision Slockpiled Fine Slag (OU 3)

5129gP:\3280-OI4\FINALROD\OU3ROD2.WPD
U.S. Environmental Protection Agency (EPA). 1989. Draft Phase II Remedial Investigation Technical Memorandum, 1986-1987, California Gulch Site, Leadville, Colorado, U.S. EPA, Prepared by CH2M Hill, May 1989.

Woodward Clyde Consultants (WCC). 1993. Draft Terrestrial Ecosystem Evaluation Report, California Gulch Site, Leadville, Colorado. April.

Record or Decision Stockpiled Fin e Slag (OU 3)

51298P:\3280-014\F!NALROD',OU3ROD2. WPD
FIGURES
CALIFORNIA GULCH SUPERFUND SITE

C OM FEDERA •! dn»L Pun PROGRAM * » McKS CORPORATIO M h*. N

GENERAL LOCATION MAP CALIFORNIA GULCH SUPERFUND SIT E LEADVILLE, COLORADO Figure 1
Operable Units Californi

a Gulch Supcrfund Site Leadville, Colorado Traiisrxiriation ami Cultural Feature* HlWSuperfun d and/or

other I'RP'x O UI - Yak Tunnel/Waier Treatment Plant O U2 -Malta Culch Fluvial Tailin g xnlvillc Coq> Mill/Malta Gulch Tailin g

O H3 -IXVRCi Slog Piles/Railroad 1-inrmenl/ Rnilrood Yntl O U4 -Upper California Ciulcl . CXI5 -Aiuroi Smellcrs/Sla|;/Mil l Sue* O IK -Slur Oilch/IVnnisc IXimrX Stray llonr CiulcWlivnns (iiilch OIF7 -Apache Toilin g ImpnuiKlmcnts C XW -Imm California Gulch

-RcsiJcnlial Populjlcd Arras CXJIO -Oregon (Julch CHMI -Arkansas River Valley Flutxlplai

n OUI2-Sit c Water Quality

i-ulure I.labilit y Dclerminatitin Kesurrection-A.iarc

o RI/K Join t Venture S Sluily Area Boundary

Containing

lluvinl Tailing Operable Units an

d Areas of Responsibility Tmispurtaiion. Cultural l-'caliira. and Hydrography from CompuSyst Inc.. 1992.

T«!

Wmclc Kock

Tailin g Impoundments

Slag

Smelter Locations

.ii.iL ImpcHiiKlnK-nis. Wane Ruck Pile*, and Slag Piles compiled by Roy f. Western. Inc.. from StcfTan.

<XH.WM anil Kirsten (SRK). I9»9; and Wnl«h and Associates ...... 1993 . . Huvial areas from Woodward -Clyde CwwiiKan'tsiTw Snwltcr iVcalions hy ASARCO. 1991. Study Area. Operable Unit, and Work Area lloundaria

del'mal hv 1:.I'A.

CALIFORNIA GULCH SUPERFUN D SIT E A ND OPERABLE UNIT S

C OM FEDERAL PROGRAMS CORPORATION LEADVILLE, COLORAD

O

• t*»M«7 M COT* dm**- » M<K«* ht.
DATUM c «75iC DA1UH

•755.0

0400 0+71 OV-1

DATUM iTsao.

0+00 0+M OV-2

S

DATUM MOQ.O

0+00 0+M OV-3

DATUM

•800.0

OWRSI7JB AVERAGE ANGLE CF RPOSE • SLT

0+00 0+53 SF-1

DATUM - NOS.OQ

i

0+000+44 SF-J

0+00 0+28

sr-3

DATUM

•810.0.

SORTCD FINES AVERAGE ANGLE CF REPOSE • 311*

0+000+41 BAL-!

BATUM i

•810.0

0+00 0+48 BM.-2

0+00 0+51 BAL-3

BALLAST AVERAGE ANGLE OF REPOSE - 28.4*

DATUM

6815.0, DATUM •7M.O

0+00 0+27 WH

DATUM - /I

0+00 0+51

DATUM -

0+00 0+65 WO-3

DATUM - •765.0o

0+000+40 UN-1

DATUM •7W.O

0+00 0+47 UN-2

0+00 0+43 UN-3

OUTLINE OF HISTORI SUPERIMPOSED ON CURl FOR READER

1C (1956) PILE IIENTSURFA C MPARISION

WATER-OUENCHED FINES AVERAGE ANCLE OF REPOSE - 31.r

UKPROCESSCD AIR-COOLED AVERAGE ANGLE OF REPOSE - 27J*

N 511,000

N 510,500

CO

AREA VOLl

CALCULA W X 20

U^««^k C nqftf i 3y

~~SOUARF ~~W8 FEET 1 TAW

480,341 1*3

e».S36 1C

102.786 91

37. IM 43

354,979 i ISO 1

40,674 IS.

44.790 23

698.300 ;

mmmmmmmmm ••••<

1,799.126 TOTAL, 422

JL/-WT W

ME

COON GRID 1002

C

-/

•\

m

\

OS3 /

304

.337

,020

.131

U

\mmmm

.569

ISURtD

/•"

1

•«SO-"

&&

# f$ '/.

s

• v '.

~f~=^ WM.V.V.VJ £7.

^XKXJI.

! +

^ 4

I I

OV-3

LEGEND i

2 SURFACE CONTOUR INTERVAL A DD 9000 TO ELEVATION CONTOURS

KUGD curators (AIR-COCUD)

•CUJ'SIA O

UKPROGESSCD AIN-COOUD

OVERSiaD (AIR-OOOUD) >J \ff

SORTCO FINES (AIN-COOUD) O/B*

UNPWXXSStD WATCT-OJEKCHOJ FINES

MIXED UNPROCESSEO AIR-COOUD/trATER-aUDCHCD

BU1AST-SIZED

VCNCCR OF AIR-00003) SLAC

ANO£ OF REPOSE CALCULATION SECTION

SECTION IKNnnCATION

OV-3

O

C OM FEDERAL PROGRAMS CORPORATION • MMdvy «l CM* Pmiir » MINM In.

GENERAL LOCATION MAP CURRENT SURFACE AREAS VOLUMES AND ANGLES OF REPOSE ARKANSAS VALLEY SLAG PIL E LEADVILLE, COLORADO Figure
LEGEND.

!• SURFACE CONTOUR INTERVAL

ELEVATIONS ARC VALUE PLUS 0.000 FEE!

WGLDCD OUTCROPS (AIR-COOLED)

•OUTSIA O

ovCTsinn (AIR-COQUD) >j t/r

UNPROCESSED AIB-COCUD

SORTED FINES (AIR-COOUD) O/T

UNPnOCCSSED WATCT-CUCTCHED FING S

.COOUO/WAT£R-OUCNO€0

GRASSES

BAUASTSinD

VtMEER OF AIR-COOUD SLAG

A AVD101 SAWPU LOCATION AND IDENTIFICATION

C OM FEDERA L PROCRAUS CORPORATION « MMMwy «f COT* fern* » M«KM Me.

GENERAL LOCATIONS A N D RECONNAISSANC E INFORMATION ARKANSAS VALLEY SLAG PILE LEADVILLE, COLORADO Figure 4
TABLES
TABLE I

ESTIMATES OF COSTS FOR REMEDIAL ALTERNATIVES

OPTION I

INSTITUTIONAL CONTROLS (I)

FENCE THE AV FINE SLAG PILE

CALIFORNIA GULCH ARKANSAS VALLEY SLAG PILE LEADV1LLE

ALTERNATIVE:

HEM:

DIRECT CAPITAL COSTS:

(Includes Labor, Equipment and Materials, Unless Otherwise Noted)

COSTS COMPONENT

1. Mobilize Materials

2. Office/Storage trailer (S'lSO')

3. Earthwork (JSO hpbulldoser)

4. Utilities Electric Phone Sanitary Station

i. Fence Materials Fencing Comer Post Braces Double Swing Gales Locks

TOTAL DIRECT COSTS

INDIRECT CAPITAL COSTS (K of Direct Capital Costs)

1. Engineering and Design (10% of Capital Costs)

2. Contingency Allowance (20% of Capital Cost) J. Other Indirect! Regulatory License/Permits (Sti of Direct Capital Costs)

TOTAL INDIRECT COSTS

PRESENT VALUE OF OPERATION AND MAINTENANCE COSTS Annual Inspection and maintenance

TOTAL COSTS

ASSUMPTIONSKOMMENTS:

UNIT

Lump

Lump

Cubic Yards

Month Month Month

Lineal Feet Each Each Opening Each

QUANTITY

I

I

5,000

/

/

/

3.300SO

106

3

3

UNIT COSTS

S2.700.00

$1.800.00

S2.SO

SI. 300.00 S6.00.00 S90.00

Slf.00 S9S.OO 5)5.00

5970.00 SIS.OO

TOTAL CAPITAL COSTS

S2.700

SI.800

S12.SOO

SI.300 S600 S90

W/.SOO

S-I.7SO S3.7JO S2.9IOHi

Year 30 S7SO.OO

SJIS.20S

SII.S2I S23.MI

SS.760

S-16.082

S8.J43

SI63.970

1. Eight (8) hods of fencing materials will be hauled using flatbed trailers.

2. Includes mob and demob, let-up and leveling. leat^down and monthly leasing charge.

3. Earthwork consists of consolidating sorted and walei^quenchedfme slags before fencing: no mob or demob, onsile contractor utilized. •I. Fencing Is 6 go. Galvanized wire, 6' high, no barbed wire. S. Gales are 20'wide and include posts and hardware.

Source: Terranext, 1996a

P:\32SO-OI4\WP\RODVTABLEI .WPD
CALIFORNIA GULCH LEADV1LLE, COLORADO

ALTERNATIVE:

ITEM

TABLE I (Continued)

ESTIMATES OF COSTS FOR REMEDIAL ALTERNATIVES

RESOURCE UTILIZATION (I)

FINE SLAG ADDITIVE MATERIAL IN CONSTRUCTION Aggregate for concrete or asphalt, add/tin to building materials, additive to

grout, concrete and slurry formations)

UNIT

Cubic Yards

Cubic Yards

QUANTITY

190.000

190,000

DIRECT CAPITAL COSTS (Includes Labor, Equipment and Materials. Unless Otherwise Noted)

COMPONENT

1. Rescreea material

2. Load and haul

TOTAL DIRECT COSTS

INDIRECT CAPITAL COSTS flt of Direct Capital Costs)

1. Engineering and Design (I OH oj Capital Costs)

2. Contingency Allowance (20X of Capital Cost)

3. Other Indincts Regulatory License/Permits (5% of Direct Capital Costs)

TOTAL INDIRECTCOSTS

CREDITS FROM SALE OF PRODUCT MATERIAL

1. Additive

2. Backfill Material

TOTAL CREDIT

TOTAL COSTS/PROFIT(i)

ASSUMPTIONS/COMMENTS:

1. Ay fine slag pile volumes are usedlo compute costs.

2. 90% of material wilt be suitable for use as additive.

3. IOM of material used as backfill material. •/. No operations and maintenance costs are necessary over an extended period. S. Credits from sale of product material have been reduced to reflect transportation costs to a major market.

Source: Terranexl, 1996a

COSTS

SS6S

S3.25

TOTAL COSTS

Sl.07f.200

S6I7.500

SI. 696.700

5169.670 S339.HO

S84.835

5593.845

Cubic Yard Cubic Yard 171.000

19.000

56.50 S3. 10

5(1.111.500) 5(58.900)

5(1.170.400)

SI.I20.H5

P:\32SO-OM\WF\ROD\TABLEI.WPD
TABLE I (Continued)

ESTIMATES OF COSTS FOR REMEDIAL ALTERNATIVES

CALIFORNIA GULCH LEADVJLLE. COLORADO

ALTERNATIVE:

ITEM:

RESOURCE UTILIZATION (1)

USED AS STAND ALONE MATERIAL IN CONSTRUCTION (Fill material)

DIRECTCAPITAL COSTS: (Includes Labor, Equipment and Materials. Unless Otherwise Noted)

COMPONENT UNIT QUANTITY

I. Load and Haul Cubic Yards 190.000

TOTAL DIRECT COSTS

INDIRECT CAPITAL COSTS (K of Direct Capital Costs)

1. Engineering and Design (lotto/Capital Costs)

2. Contingency Allowance (20K of Capital Cost)

3. Other Indirecls Regulatory Ucenst/Ptrmits (i% of Direct Capital Costs)

TOTAL IND1RECTCOSTS

TOTAL COSTS (Direct plus Indirect)

CREDITS FROM SALE OF PRODUCT MATERIAL

I. Backfill Material Cubic Yard 190.000

TOTAL CREDIT TOTAL COSTyPROFlTfS)

ASSUMPTIONSKOMMENTS:

1. Ay Fine slag volumes are used to compute costs.

2. 100% of material will be suitable Jor use as backfill.

3. Load and haul is for conveyance to suitable rail loading dock. •I. Credits from sale of product material have been reduced due to transportation costs to a major market. S. Annual Operations and Maintenance costs are included in estimate.

Source: Tenanott, I996a

CAPITAL COSTS

S3.2S

53.10

TOTAL COSTS

5617.500

t6l7.SOO

S61.7SO SI23.SOO

S30.87S

5216.125

5833,625

5(589.000)

S(S89.000) S2U.625

P:\328WJ14\WIMIOD\TABLE1 .WPD
TABLE 2 GRID COMPARISON METHOD FOR ALTERNATIVES ANALYSIS

Criterion

1) Protection of Human Health and Environment

2) Attainment of ARARs

3) Long term Effectiveness

4) Reduction of Toxicity, Mobility or Volume

5) Short term Effectiveness

6) Implementability

7) Cost

8) State Acceptance

9) Community Acceptance

Total

Alternative 1 No Action

5

5

4

2

5

5

5

5

5

41

Alternative 2 Institutional Controls

5

5

4

2

4

5

4

5

5

39

Alternative 3 Resource Utilization

5

5

5

2

3

3

3

5

5

36

Notes: Scale of 1-5, where 5 = Highest Attainment Source: Terranext, 1996a

P:\32SO-OU\WPJIOD\TABLE3.WPD
APPENDIX A

ARARs
SUMMARY OF FEDERAL AND STATE ARARS

Clean Air Act, National Primary and Secondary Ambient Air Quality Standards

National Historic Preservation Act(NHPA )

Executive Order 11 593 Protection and Enhancement of

the Cultural Environment

Hazardous Materials Transportation Act

40 CFR Part 50

16USC§470£issg.

40CFR§6.301(b )

36 CFR Part 63, Part 65, Part 800

16 USC § 470

49 USC §1801-1813

49 CFR 107, 171-177

No

Y es

Y es

Y es (for contingency

reuse only)

No

— —

National ambient air quality standards (NAAQS) are

implemented through the New Source Review Program and State Implementation Plans (SIPs). The federal New Source Review program address only major sources. There

will be no emissions associated with the chosen remedial

action in OU3. Emissions associated with the contingency

remedy will be limited to fugitive dust associated with

moving and sorting the slag for reuse. These activities will

not constitute a major source. Therefore, attainment and

maintenance of NAAQS pursuant to the New Source Review Program are not ARARs. See Colorado Air Pollution Prevention and Control Act concerning

applicability of requirements implemented through the SIP.

Expands historic preservation programs; requires

preservation of resources included in or eligible for listing

on the National Register for Historic Places.

Directs federal agencies to institute procedures to ensure

programs contribute to the preservation and enhancement

of non- federally owned historic resources. Consultation

with the Advisory Council on Historic Preservation is

required if removal activities should threaten cultural

resources.

Regulates transportation of hazardous materials.

P:\3280-014\FINALROD\OU3 ARAR.FNL
SUMMARY OF FEDERAL AND STATE ARARS (Continued)

STATE OF COLORADO

Colorado Air Pollution Prevention and Control Act5 CCR 1001, Regulation 1, Section III.DY es Requires all sources of paniculate emissions to apply

technically feasible and economically reasonable control

measures. APCD has the authority to ask for a fugitive

emission control plan from any location, if blowing

paniculate matter is a problem. The site does not need to

be in active use for this requirement to apply. Technically

feasible and economically reasonable control measures will

be applied to reuse of the stockpiled fine slag.

Colorado Air Pollution Prevention and Control Act5 CCR 1001-3; Sections III.D.l.b.c.d. Sections III.D.2.b,c,e,f,g. Regulation 1Y es (for contingency

reuse only) Regulation No. 1 provisions concerning fugitive emissions

for storage and stockpiling activities, haul roads, and haul

trucks are applicable (5 CCR 1001-3; Sections III.D.2.b,c,e,f,g.) to the reuse contingency.

Colorado Air Pollution Prevention and Control Act

5 CCR 1001-4; Regulation 2Y es (for contingency

reuse only) Provisions concerning odors would be applicable if

contingency reuse were to cause objectionable odors.

Colorado Air Pollution Prevention and Control Act

5 CCR 1001-5 Regulation 3 APENsY es (for contingency

reuse only) Substantive provisions of APENs will be met.

Colorado Air Pollution Prevention and Control Act

5 CCR 1001-10 Part C (I) &(II) Regulation 8Y es (for contingency

reuse only)

Regulation 8 sets emission limits for lead. Applicants are

required to evaluate whether the proposed activities would

result in the Regulation 8 lead standard being exceeded. There are no emissions associated with the chosen remedial

action. The contingency reuse in OU3 is not projected to

exceed the emission levels for lead, although some lead

emissions may occur. Compliance with Regulation 8 will

be achieved by adhering to a fugitive emissions control

plan prepared in accordance with Regulation No. 1.

P:\3280-014\FINALROD\OU3ARAR.FNL
SUMMARY OF FEDERAL AND STATE ARARS (Continued)

Colorado Air Pollution Prevention and Control

5 CCR 1001-14; Ambient Air Quality Standards

Y es (for contingency

reuse only) Provisions concerning State TSP standards and Federal PM-10 standards would appl y if contingency reuse occurs,

or if the Site is the subject of fugitive emission complaints. In such a case, compliance with the applicable provisions of

the Colorado air quality requirements will be achieved by

adhering to a fugitive emissions control plan prepared in

accordance with Regulation No. 1.

Colorado Water Quality Control Act, Storm Water Discharge Regulations

5 CCR 1002-2 Y es Establishes requirements for storm water discharges (except

portions relating to Site-wide Surface and Groundwater). Substantive requirements for storm water discharges

associated with construction activities are applicable.

Colorado Noise Abatement Act CRS§ § 25-12-101 to 108 Y es (for contingency

reuse only)

Establishes maximum permissible noise levels for

particular time periods and land use.____

P:\3280-014\FINALROD\O.U3ARAR-FNL