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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 6
RECORD OF DECISION
OPERABLE UNIT 4
CHAT PILES, OTHER MINE AND MILL WASTE, AND SMELTER WASTE
TAR CREEK SUPERFUND SITE
OTTAWA COUNTY, OKLAHOMA
OKD980629844
February 20, 2008
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Record of Decision Page i
Tar Creek OU4 Superfund Site February 2007
List of Figures iv
List of Tables iv
Appendix iv
PART I: THE DECLARATION
1.0 SITE NAME AND LOCATION
2.0 STATEMENT OF BASIS AND PURPOSE
3.0 ASSESSMENT OF THE SITE
4.0 DESCRIPTION OF THE SELECTED REMEDY
5.0 STATUTORY DETERMINATIONS 3
6.0 DATA CERTIFICATION CHECKLIST 3
7.0 AUTHORIZING SIGNATURE 4
PART 2: THE DECISION SUMMARY 5
8.0 SITE NAME, LOCATION, AND BRIEF DESCRIPTION 5
9.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES 5
9.1 History of Site Activities 5
9.2 History of Federal and State Investigations and Removal/Remedial Actions 6
9.3 History of CERCLA Enforcement Activities 7
9.3.1 Operable Unit 1 7
9.3.2 Operable Unit 2 8
9.3.3 Operable Unit 4 8
10.0 COMMUNITY PARTICIPATION 9
10.1 Community Involvement Plan 9
10.2 Community Participation Activities 9
10.3 Technical Assistance Grant 10
10.4 Local Site Repository 10
11.0 SCOPE AND ROLE OF OPERABLE UNITS AND RESPONSE ACTION 10
12.0 SITE CHARACTERISTICS 11
12.1 Conceptual Site Model 11
12.2 Site Overview 12
12.3 Surface and Subsurface Features 12
12.4 Sampling Strategy 13
12.5 Treatability Study 13
12.6 Known or Suspected Sources of Contamination 13
12.7 Types of Contamination and Affected Media 13
12.7.1 Chat Piles 14
12.7.2 Chat Bases 14
12.7.3 Fine Tailings 14
12.7.4 Smelter Wastes 15
12.7.5 Transition Zone Soils 15
12.7.6 Smelter Waste Affected Soils 16
12.7.7 Rural Residence Yard Soils 16
12.7.8 Ground water 17
12.7.9 Surface Water 17
12.7.10 Biota 17
12.7.11 Edible Plants 17
12.8 Locations of Contamination and Known or Potential Routes of Migration 17
13.0 CURRENT AND POTENTIAL FUTURE LAND AND WATER USES 18
13.1 Current and Potential Future Land Uses 18
13.2 Current and Potential Future Ground Water Uses 18
14.0 SUMMARY OF SITE RISKS 19
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Tar Creek OU4 Superfund Site February 2007
14.1 Summary of Baseline Human Health Risk Assessment 19
14.1.1 Identification of Chemicals of Concern 19
14.1.2 Exposure Assessment 19
14.1.3 Toxicity Assessment 20
14.1.4 Risk Characterization 20
14.1.4.1 Risk Estimations 22
14.1.5 Uncertainty Analysis 22
14.1.5.1 Data Evaluation Uncertainty 22
14.1.5.2 Exposure Assessment Uncertainty 22
14.1.5.3 Toxicity Assessment Uncertainty 22
14.1.5.4 Risk Characterization Uncertainty 23
14.2 Summary of Ecological Risk Assessment 23
14.3 Basis for Remedial Action 24
15.0 REMEDIAL ACTION OBJECTIVES 26
15.1 Remedial Action Objectives for the Site 26
15.2 Basis and Rationale for Remedial Action Objectives 28
16.0 DESCRIPTION OF ALTERNATIVES 28
16.1 Description of Remedy Components 30
16.1.1 Alternative 1 - No Action 30
16.1.2 Alternative 4 - Phased Consolidation, Chat Sales and On-site Disposal 30
16.1.3 Alternative 5 - Voluntary Relocation, Phased Consolidation, Chat Sales and On-
site Disposal 31
16.1.4 Alternative 8 - Chat Sales and Total Source Consolidation 34
16.2 Common Elements and Distinguishing Features 36
16.2.1 Chat Use and Sales 36
16.2.2 Certification, Record Keeping and Reporting 36
16.2.3 Watershed-Based Approach 36
16.2.4 Five-Year Reviews 37
16.2.5 Institutional Controls 37
16.2.6 Presumptive Remedies 37
16.3 Expected Outcomes of Each Alternative 37
17.0 COMPARATIVE ANALYSIS OF ALTERNATIVES 38
17.1 Overall Protection of Human Health and the Environment 38
17.2 Compliance with ARARs 39
17.3 Long-Term Effectiveness and Permanence 39
17.4 Reduction in Toxicity, Mobility, and Volume 41
17.5 Short-Term Effectiveness 41
17.6 Implementability 42
17.7 Cost 43
17.8 State And Tribal Acceptance 43
17.9 Community Acceptance 43
18.0 PRINCIPAL THREAT WASTE 44
19.0 SELECTED REMEDY 44
19.1 Summary of the Rationale for the Selected Remedy 44
19.2 Description of the Selected Remedy 44
19.2.1 Voluntary Relocation 45
19.2.2 Chat Sales and Environmentally Acceptable Chat Use 45
19.2.3 Watershed-Based Approach 49
19.2.4 Phase 1 Elements 49
19.2.4.1 Remedial Actions in Distal Areas 49
19.2.4.2 Smelter Waste Remedial Actions 50
19.2.4.3 Fine Tailings Remedial Actions 50
19.2.4.4 Remedial Actions Addressing In-stream Source Materials 51
19.2.4.5 Remedial Actions Addressing Rural Residential Wells 51
19.2.4.6 Remedial Actions Addressing Rural Residential Yard Soil 51
19.2.4.7 Construction of On-site Repositories 52
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19.2.4.8 Five-Year Reviews 52
19.2.5 Phase 2 Elements 52
19.2.5.1 Remedial Actions Addressing Unmarketable Chat 52
19.2.6 Other Planned Actions Common to Both Phases 53
19.3 Summary of the Estimated Remedy Costs 54
19.4 Expected Outcomes of the Selected Remedy 55
19.4.1 Available Uses of Land 55
19.4.3 Final Remediation Goals 55
20.0 STATUTORY DETERMINATIONS 55
20.1 Protection of Human Health and the Environment 55
20.2 Compliance with Applicable or Relevant and Appropriate Requirements 55
20.3 Cost-Effectiveness 56
20.4 Utilization of Permanent Solutions to the Maximum Extent Practicable 59
20.5 Preference for Treatment as a Principal Element 60
20.6 Five-Year Review Requirements 60
21.0 DOCUMENTATION OF SIGNIFICANT CHANGES FROM PREFERRED
ALTERNATIVE OF PROPOSED PLAN 60
22.0 STATE ROLE 61
PART 3: RESPONSIVENESS SUMMARY 62
23.0 RESPONSIVENESS SUMMARY 62
23.1 Summary and Response to Local Community Concerns 63
23.2 Summary and Response to Specific Legal and Technical Questions 70
23.3 Community Outreach History 95
24.0 TECHNICAL AND LEGAL ISSUES 98
24.1 Technical Issues 98
24.2 Legal Issues 99
PART 4: BIBLIOGRAPHY 101
GLOSSARY OF TERMS 107
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List of Figures
Figure 1 Site Location Map
Figure 2 Location of Source Material
Figure 3 Tar Creek Distal Zones and Watersheds
Figure 4 Source Materials, Transport Mechanisms, and Affected Media
Figure 5 Conceptual Site Model for HHRA
Figure 6 Conceptual Site Model and Terrestrial Endpoints
Figure 7 USGS Land Use Surface Feature Map
Figure 8 Tar Creek OU4 Land Use Surface Feature Map
Figure 9 Relocation Assistance Zone
Figure 10 Estimated Source and Seepage Control Locations
Figure 11 Fine Tailing Location and Proposed Disposition
List of Tables
Table 1
Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations
Table 2
Summary of General Public Resident Exposure Parameters based on Reasonable
Maximum Exposure
Table 3
Summary of Subsistence Resident Exposure Parameters based on Reasonable Maximum
Exposure
Table 4
Summary of Adolescent Recreator Exposure Parameters based on Reasonable Maximum
Exposure
Table 5
Cancer Toxicity Data Summary
Table 6
Non-Cancer Toxicity Data Summary
Table 7
Risk Characterization Summary - Non-Carcinogens
Table 8
Summary of Blood Lead Concentrations Risk Estimations (from ALM)
Table 9
Summary of Blood Lead Concentrations Risk Estimations (from IEUBK Model)
Table 10
Comparative Analysis of Remedial Alternatives with Respect to Cost
Table 11
Estimated Costs for Alternative 5
Table 12
Final Remediation Goals for Chemicals of Concern
Table 13
Final Federal and State ARARs
Table 14
Matrix of Cost and Effectiveness Data
Appendix
Appendix A ODEQ Concurrence with the Selected Remedy
Appendix B Administrative Record Index
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LIST OF ACRONYMS AND ABBREVIATIONS
ALM Adult Lead Methodology
AOC Area of Concern
ARARs Applicable or Relevant and Appropriate Requirements
bgs below ground surface
BIA Bureau of Indian Affairs
BHHRA Baseline Human Health Risk Assessment
BLLs Blood Lead Levels
CDI Chronic Daily Intake
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CHAMP Community Health Action and Monitoring Program
COC Chemicals of Concern
COPC Chemical of Potential Concern
CSM Conceptual Site Model
DOI Department of the Interior
ELCR Excess Lifetime Cancer Risk
EPA United States Environmental Protection Agency
EPC Exposure Point Concentration
ESD Explanation of Significant Difference
ft/day feet per day
FR Federal Register
FS Feasibility Study
HEAST Health Effects Assessment Summary Tables
HI Hazard Index
HQ Hazard Quotient
HRS Hazard Ranking System
IEUBK Integrated Exposure Uptake Biokinetic
IRIS Integrated Risk Information System
LDR Land Disposal Regulations
LICRAT Lead Impacted Communities Relocation Assistance Trust
LNAPL Light Non-Aqueous Phase Liquid
LOAEL Lowest-Observed-Adverse-Effect Level
MCL Maximum Contaminant Level
mg/kg milligram/ kilogram
mg/1 milligram/liter
|ig/l microgram/liter
MSHA Mine Safety and Health Administration
NCEA National Center for Environmental Assessment
NCP National Oil and Hazardous Substance Pollution Contingency Plan
NESHAPS National Emission Standards for Hazardous Air Pollutants
NOAEL No Observable Adverse Effects Level
NPL National Priorities List
O&M Operation and Maintenance
ODEQ Oklahoma Department of Environmental Quality
OPA Oil Pollution Act
OW Oily Water
OWRB Oklahoma Water Resources Board
PPRTV Provisional Peer Reviewed Toxicity Values
PRGs Preliminary Remedial Goals
PRP Potentially Responsible Party
RAOs Remedial Action Objectives
RCRA Resource Conservation and Recovery Act
RD Remedial Design
RfC Reference Concentration
RfD Reference Dose
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RG
Remediation Goals
RI
Remedial Investigation
RI/FS
Remedial Investigation/Feasibility Study
RME
Reasonable Maximum Exposure
ROD
Record of Decision
SARA
Superfund Amendments and Reauthorization Act of 1986
SF
Slope Factor
Site
Tar Creek Superfund Site
SLERA
Screening Level Ecological Risk Assessment
SPLP
Synthetic Precipitation Leaching Procedure
svoc
Semivolatile Organic Compound
TAG
Technical Assistance Grant
TCLP
Toxicity Characteristic Leaching Procedure
TDS
Total Dissolved Solids
TSP
Total Suspended Particles
UCL
Upper Confidence Limit
UIC
Underground Injection Control
URA
Uniform Relocation and Real Property Acquisition Policies Act
USFWS
United States Fish and Wildlife Service
USGS
United States Geological Survey
WRDA
Water Resources Development Act of 2007
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PART I: THE DECLARATION
1.0 SITE NAME AND LOCATION
The Tar Creek Superfund Site is located in Ottawa County, Oklahoma. The National Superfund Database
Identification Number is OKD980629844.
2.0 STATEMENT OF BASIS AND PURPOSE
This decision document presents the "Selected Remedy" for the Tar Creek Superfund Site (hereinafter "the
Site," Figure 1 - Site Location Map) which was chosen in accordance with the Comprehensive
Environmental Response, Compensation and Liability Act of 1980 (CERCLA), 42 United States Code
§9601 et seq., as amended, and, to the extent practicable, the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP), 40 CFR Part 300, as amended. This decision is based on the
Administrative Record for Operable Unit 4 of the Site.
The State of Oklahoma, acting through the Oklahoma Department of Environmental Quality (ODEQ),
concurs with the selected remedy.
3.0 ASSESSMENT OF THE SITE
The response action selected in this Record of Decision (ROD) is necessary to protect the public health or
welfare or the environment from actual or threatened releases of hazardous substances into the
environment.
4.0 DESCRIPTION OF THE SELECTED REMEDY
The Selected Remedy for Operable Unit 4 is Alternative 5 ~ Voluntary Relocation, Phased Consolidation,
Chat Sales and On-site Disposal as presented in the Proposed Plan, July 30, 2007, with the following
modifications: (1) relocation under the Selected Remedy is exempt from the Uniform Relocation and Real
Property Acquisition Policies Act (URA)1 and (2) the timeframe for chat sales is extended to 30 years. To
emphasize the continuity in our remedy selection process, EPA will continue to refer to the Selected
Remedy in this ROD as Alternative 5.
The Preferred Alternative 4 did not include voluntary relocation. However, based on State, Tribal and
community concerns as well as changes in the cost effectiveness of relocation following the enactment of
WRDA, EPA has included relocation in its Selected Remedy for the Site. Preferred Alternative 4 also
limited chat sales to 20 years. However, since the residents facing the greatest risk of exposure will be
relocated, the EPA has extended the timeframe for chat sales to 30 years in its Selected Remedy. The
remaining elements of the Selected Remedy are identical to Alternative 4.
If a Selected Remedy involves a significant change to a feature of the Preferred Alternative proffered to the
public in the Proposed Plan for a Superfund Site, EPA's policy is that the ROD is to indicate the significant
changes made, and should provide a rationale for the changes (e.g., new information or arguments provided
in public comments). EPA is providing such a rationale in Section 21 of this ROD. In this case, EPA
generally did not change the Preferred Alternative, but only added to it (i.e., EPA added relocation and new
timeframes for implementation). In addition, the addition of relocation could have been reasonably
anticipated based on the extensive discussions of relocation originally presented in the Proposed Plan, in
the Remedial Investigation and Feasibility Study Reports (RI/FS), and in the Administrative Record file.
1 The Water Resources Development Act of 2007 (WRDA) Section 3135 exempts the relocation at the Site
from the URA.
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The Selected Remedy will address source materials, rural residential yard contamination, transition zone
soil contamination, and contamination in water drawn from rural residential wells. "Source material," as
used in this Record of Decision, means mine and mill waste including chat, fine tailings, overburden,
development rock, smelter waste and other tailings. Source material is generally found in chat piles, chat
bases (the area once occupied by a chat pile), smelter wastes, and tailings ponds as shown in Figure 2.
These materials contain hazardous substances that are a source of OU4 contamination. The Selected
Remedy is estimated to cost $167,288,000.
The Selected Remedy will utilize various elements to include the following:
PHASE 1
Phase 1 will address voluntary relocation of residents, chat sales, and address source materials in a manner
that will reduce the overall footprint of contamination and reduce the need for land use restrictions,
institutional controls, and operation and maintenance.
Residents located in Picher, Cardin and Hockerville will be voluntarily relocated following the
procedures and priorities established by the Lead Impacted Communities Relocation Assistance
Trust (LICRAT).
Chat and chat bases from distal areas (Figure 3), including associated historic chat covered haul
roads and non-operating railroad grades, will be excavated to the underlying native soil,
transported and released to an on-site chat processor or future processing location located in a
previously contaminated area of the Site, injected into mine workings, or disposed in an on-site
repository.
Transition zone soils (soils around and underneath source materials) will be addressed by
excavation followed by natural soil rebuilding.
Smelter wastes will be excavated and disposed in an on-site repository. Smelter affected soils will
be managed in the same manner as transition zone soils.
Fine tailings will be injected into mine workings or covered in place. The covered fine tailings
may be consolidated to reduce the footprint of the final cover.
Source material in Tar, Lytle, Elm or Beaver Creek or other Site waterways, will be addressed on
a priority basis through either excavation and/or the installation of a flexible membrane liner, as
needed as determined by EPA. As an interim measure, sheet piling, berms, constructed wetlands,
or other engineering controls will be installed for near-stream source materials to help prevent
contamination from migrating to surface water.
An alternative water supply will be provided to any household where mining-related contaminants
in water drawn from rural residential wells exceed 0.015 mg/L for lead for rural households.
Rural households that are within the area that has been designated for relocation under the Lead
Impacted Communities Relocation Assistance Trust (LICRAT) relocation program, but which do
not elect to participate in the relocation program, would be included in the households eligible for
an alternative water supply (estimated two residences).
Rural residential yards that are found to have concentrations of soil lead that exceed 500 ppm will
be excavated to a maximum depth of 12 inches, and the excavated area will be backfilled with
clean soil, contoured to promote drainage and revegetated. This includes residential yards that are
identified for relocation. The provisions of the preceding sentence apply to approximately 4
households, based on the RI sampling. That is, if those eligible for relocation decide not to
relocate, their yards will be remediated.
On-site repositories will be constructed to accept Site source materials for final disposal. On-site
repositories will be closed when they reach capacity or at completion of the remedial action.
Closure will be accomplished by covering the repository with a soil cover, contoured to promote
drainage, and revegetated.
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PHASE 2
Phase 2 addresses certain source areas that remain after Phase 1 cleanup activities. These areas may
include chat bases, tailings ponds, unmarketable chat piles and bases, and remaining chat from distal area
consolidation. Chat sales will continue.
The remedy will be reviewed, at a minimum, every five years since hazardous substances remain
on-site with concentrations that exceed concentration levels that allow for unrestricted use and
unrestricted exposure. The remedy will be reviewed to ensure protection of human health and the
environment. As part of the five-year review, EPA will evaluate the progress of chat sales. Chat
piles and bases remaining after 10 years will be evaluated for commercial viability. This
determination will be made using input from the chat/land owners, appropriate tribal
representatives, and the commercial operators.
Unmarketable chat piles and bases will be excavated, transported and released to an on-site chat
processor or future processing location in a previously contaminated area of the Site, injected into
mine workings, or they will be disposed in an on-site repository.
Abandoned chat haul roads and non-operating railroad grades that are contaminated will be
managed the same as unmarketable chat piles and bases. That is, they will be excavated,
transported to an on-site chat processor, and released to that processor, or they will be disposed in
an on-site repository.
Institutional controls and operation and maintenance activities will be implemented, as needed as
determined by EPA, at repositories and covered, fine tailings ponds.
Environmental monitoring will be conducted, as needed as determined by EPA, to test for
contamination in ambient and near source air, surface water, ground water, and sediment during
remediation activities.
5.0 STATUTORY DETERMINATIONS
The Selected Remedy is protective of human health and the environment, complies with Federal and State
requirements that are applicable or relevant and appropriate to the remedial action, is cost effective, and
utilizes permanent solutions and alternative treatment (or resource recovery) technologies to the maximum
extent practicable.
High concentrations of lead are addressed under the Selected Remedy; however, the concentrations of lead
are not so high as to be several orders of magnitude above levels that allow for unrestricted use and
unlimited exposure. Therefore, the lead is not considered to be a principal threat under the NCP;
consequently, there is no expectation under the NCP that the lead be treated.
Because this remedy will result in hazardous substances, pollutants, or contaminants remaining on-site
above levels that allow for unrestricted use and unrestricted exposure, a statutory review will be conducted
within five years after initiation of the remedial action to ensure that the remedy is, or will be, protective of
human health and the environment.
6.0 DATA CERTIFICATION CHECKLIST
The following information is included in the Decision Summary section of this Record of Decision (Part 2).
Additional information can be found in the Administrative Record file for this Site.
• Chemicals of concern and their respective concentrations (pages 13-17)
• Baseline risk represented by the chemicals of concern (pages 19-24)
• Remediation Goals established for chemicals of concern and the basis for these levels (pages 27-
29)
• How source materials constituting principal threats are addressed (page 45)
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• Current and reasonably anticipated future land use assumptions and current and potential future
beneficial uses of ground water used in the Baseline Human Health Risk Assessment and ROD
(page 18)
• Potential land and ground water use that will be available at the site as a result of the Selected
Remedy (page 55)
• Estimated capital, annual operation and maintenance (O&M), and total present worth costs,
discount rate, and the number of years over which the remedy cost estimates are projected (page
• Key factors) that led to selecting the remedy (i.e. a description of the Selected Remedy that
explains how the Selected Remedy provides the best balance of tradeoffs with respect to the
balancing and modifying criteria, highlighting criteria key to the decision) (page56)
This ROD documents the Selected Remedy for the Tar Creek Superfund Site. This remedy was selected by
the Environmental Protection Agency (EPA) with the concurrence of the Oklahoma Department of
Environmental Quality. The Director of the Superfund Division (EPA, Region 6) has been delegated the
authority to approve and sign this ROD.
45)
7.0 AUTHORIZING SIGNATURE
Superfund Division (6SF)
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PART 2: THE DECISION SUMMARY
This Decision Summary provides a description of the site-specific factors and analyses that led to the
selection of a remedy for chat piles, other mine and mill waste, and smelter waste at the Site. It includes
background information about the Site, the nature and extent of contamination found at the Site, the
assessment of human health and environmental risks posed by the contaminants at the Site, and the
identification and evaluation of remedial action alternatives for the Site.
Due to the complex nature of contamination associated with the Tar Creek Site, remediation has been
handled through various removal response actions and remedial actions. The following five operable units
(OUs) have been designated at the Site: OU1 - surface water/ground water; OU2 - residential areas; OU3 -
Eagle-Picher Office Complex (abandoned mining chemicals); 0U4 - Mine and Mill Waste, and Smelter
Waste and, 0U5 - Sediments. A ROD was signed for OU1 in 1984 that addressed the surface water
degradation of Tar Creek and the threat of contamination to the drinking water. This OU1 remedy is in an
after-action monitoring phase. The ROD for OU2 was signed in 1997 and has addressed lead-contaminated
soils at more than 2,295 homes and properties. OU3 was a removal action that requires no further action,
and OU5 is currently in the early site characterization phase.
8.0 SITE NAME, LOCATION, AND BRIEF DESCRIPTION
The Tar Creek Superfund Site (OKD980629844) is a former lead and zinc mining area located in Ottawa
County, Oklahoma. The Site is part of the Tri-State Mining District located at the junction of Oklahoma,
Kansas, and Missouri. The Site has no clearly defined boundaries, but consists of the areas of Ottawa
County impacted by mining waste. The Site includes all of the area (approximately 40 square miles) in
northern Ottawa County where lead and zinc mining operations were conducted and any area where a
hazardous substance from mining or milling in Ottawa County has been stored or disposed. This ROD for
OU4 focuses on the 40 square mile area which is generally depicted in Figure 1. The Site also includes all
suitable areas in very close proximity to the contamination necessary for implementation of the response
action. The Site is bounded by the State of Kansas to the north. The principal Site communities include
Cardin, Commerce, North Miami, Picher, and Quapaw. Approximately 19,556 people live on-site in the
mining area and in communities in proximity to the mining area (EPA, 2004).
EPA is the lead agency and ODEQ is the support agency for Operable Unit 4. Some of the Potentially
Responsible Parties (PRPs) identified for the Site did participate in the remedial process for Operable Unit
4 by undertaking the Remedial Investigation and by preparing a draft Feasibility Study. EPA implemented
the human health and ecological risk assessments at the Site and completed the Feasibility Study.
Mine and mill wastes are located throughout the Site. Some areas have chat, a type of waste tailings
produced by the gravity separation milling process, in piles up to 200 feet high. Other areas of the Site
include agricultural or residential properties. Mine and mill wastes are typically located adjacent to the
former mines which are concentrated near the town of Picher, but are also scattered throughout the rest of
Ottawa County.
9.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
This section of the ROD provides the history of the Site and a brief discussion of the EPA's removal,
remedial, and enforcement activities.
9.1 History of Site Activities
The first ore discoveries and earliest mining operations in Ottawa County, Oklahoma occurred in the
vicinity of Peoria (6 miles east and 1 mile south of Lincolnville) in 1891 (Weidman, 1932). The next major
ore discoveries occurred 1.5 miles northeast of Lincolnville near Quapaw in 1902, followed by discoveries
in 1905 near Commerce. The real expansion of zinc and lead mining at the Site occurred after a major ore
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discovery in 1914 near the current site of Picher, Oklahoma. Following this discovery, there was a major
expansion of mining in what became known as the Picher Mining Field (Picher Field) of Oklahoma and
Kansas. By 1918, the Oklahoma section of the Picher Field was well defined by producing mines, with 230
mills built or under construction (Luza, 1986).
Depletion of high-grade ores caused a marked decline in annual production after 1946, and depressed
metal-market prices forced a cessation of most mining activities in 1958 (Brichta, 1960). The last record of
significant production from Ottawa County occurred in 1970 (McKnight and Fischer, 1970).
With few exceptions, the crude ore produced at the Site was mined utilizing underground mining methods.
Based on production records maintained by the U.S. Department of Interior, Bureau of Mines, a total of
181,048,872 tons of crude ore was produced from the Oklahoma portion of the District. Milling of this ore
produced 8,884,898 tons of zinc concentrates and 1,686,713 tons of lead concentrates. With the exception
of a limited amount of lead concentrates treated at the Ontario Smelter, all of the concentrates produced
from the Site were transport off-Site for the conversion of the concentrates to metal by smelting.
The by-products of the mining operation were discarded mining and milling tailings. The mill tailings,
locally know as chat, are primarily composed of small chert fragments, intermingled with sand-sized
particles. After the excavated rock was processed and the metal ore extracted, the mining tailings that
remained were deposited into piles that were up to 200 feet in height. Many of these chat piles remain on
the Site, including some piles which are over 100 feet high. An inventory conducted in 2005 as part of the
Remedial Investigation for OU4 identified 83 chat piles occupying 767 acres with 31 million cubic yards,
243 chat bases (or former piles) occupying 2079 acres with an estimated 6.7 million cubic yards.
In addition to piles of mining wastes, a large but lesser quantity of floatation pond tailings from the
floatation milling process was produced. Most of the floatation ponds have since evaporated leaving
behind a very fine mining waste sediment which remains on the Site. Fine tailings generated from milling
and washing chat are currently found in 63 ponds occupying 820 acres and total approximately 9 million
cubic yards.
Over the years, the mining wastes have been used and continue to be used for a variety of purposes
including the following: railroad ballast; concrete and asphalt aggregate; sandblasting sand; sandbag sand;
roadway, driveway, alleyway, and parking lot aggregate; general fill material in residential areas; and
impact-absorbing material in playgrounds.
The Site first came to the attention of the State of Oklahoma and EPA in 1979 when acid mine drainage
began flowing to the Site surface from underground mines through abandoned mine shafts and boreholes.
The Governor of Oklahoma formed the Tar Creek Task Force to investigate the effects of acid mine
drainage on the area's surface and ground water. Based upon the information discovered by the Tar Creek
Task Force, EPA proposed, in July 1981, to add the Site to the Superfund National Priorities List (NPL), 40
CFR Part 300, Appendix B. The NPL means the list, compiled by EPA pursuant to CERCLA section 105,
of uncontrolled hazardous substance releases in the United States that are priorities for long-term remedial
evaluation and response. The Site was added to the NPL in September 1983.
9.2 History of Federal and State Investigations and Removal/Remedial
Actions
Due to the complex nature of contamination associated with the Tar Creek Site, remediation has been
handled through various removal response actions and Remedial Actions (RA). The following five
operable units or OUs have been designated at the Site: OU1 - surface water/ground water; OU2 -
residential areas; OU3 - Eagle-Picher Office Complex (abandoned mining chemicals); OU4 - Mine and
Mill Waste, and Smelter Waste and, OU5 - Sediments. RODs have been signed for OU1 and OU2, OU3
was a removal action that requires no further action, and OU5 is currently being assessed. To address the
concerns of the State and the Tribes for the sediment and surface water downstream of the central mining
area, OU5 will examine the nature and extent of contaminated sediment in Elm Creek and Tar Creek
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February 2007
starting at the confluence of Tar Creek and Lytle Creek to the Neosho River down to the point where it
flows into Grand Lake.
In 1984, EPA issued its first Site Record of Decision (ROD). The 1984 ROD applied to two concerns
which are now referred to as Operable Unit 1 (OU1): 1) the surface water degradation of Tar Creek, a
stream located on the Site, by the discharge of acid mine water; and 2) the threat of contamination to the
Roubidoux Aquifer, a drinking water source. Pursuant to EPA's 1984 ROD, dikes were constructed to
reduce the inflow of surface water to certain mine shafts on the Site and to reduce the outflow of acid mine
drainage from the subsurface to Tar Creek. In addition, abandoned wells that went through the Boone
Aquifer to the deeper Roubidoux formation were plugged to prevent contamination from the Boone from
seeping through cracked well casings and reaching the Roubidoux, a drinking water source. Abandoned
wells that could threaten the Roubidoux are still being discovered and plugged as part of the After Action
Monitoring Program for OU 1.
In 1994, Indian Health Service test results concerning the blood lead levels of Indian children living on the
Site indicated that approximately 35 percent of the Indian children tested had concentrations of lead in their
blood exceeding 10 micrograms per deciliter (|ig/dL). In August 1994, to address the threat of lead
exposure to children, EPA began sampling soils at High Access Areas (HAAs) on the Site such as day
cares, schoolyards, and other areas where children congregate. EPA sampled 28 HAAs between August
1994 and October 1994. The sampling detected significant concentrations of lead, cadmium, and other
heavy metals in surface soils. In March 1995, EPA expanded its sampling activity to include all residences
on the Site.
In 1995, EPA began to excavate contaminated soil at HAAs and at Site residences using its removal action
authority. Concurrently, EPA began a Remedial Investigation/Feasibility Study for Site residential areas,
referred to as Operable Unit 2 (OU2). In 1997, EPA issued a ROD to address contaminated soil in the
residential areas of OU2. Under the removal actions and under the OU2 ROD, EPA has excavated lead-
contaminated soil at more than 2,295 homes and properties. The remediation of the yards and the public
areas and the education and outreach programs implemented by the Ottawa County Health Department are
helping to protect the children's health. In 1996, data from the Oklahoma State Department of Health
(OSDH) showed that among young children (aged 1-5 years) living at the site, 31.2% had a blood lead
level at or above 10 micrograms per deciliter (|ig/dL). the Centers for Disease Control and Prevention
(CDC) level of health concern. By 2003, OSDH data indicated that elevated blood lead levels among
children in the same age group had dropped to just 2.8%.
OU3 was a removal action that addressed lab chemicals in an abandoned office building on the Site.
Under the statutory requirements of Section 121(c) of CERCLA, 42 U.S.C. § 9621(c), and its implementing
regulation 40 CFR § 300.430(f)(4)(ii), every five years, EPA is required to review sites it has addressed
under Superfund where hazardous substances remain on-site above concentration levels that allow for
unrestricted use and unrestricted exposure. Three five-year reviews have been performed at the Tar Creek
Site. The first review was completed in April 1994, the second five-year review was completed in April
2000 and the third review was completed in September 2005. The most recent Five-Year Review Report is
available online at http://www.epa.gov/earthlr6/6sf/pdffiles/tc_5yr_2005-09.pdf
A Memorandum of Understanding was signed in May 2003 between the EPA, the DOI, and the U.S. Army
Corps of Engineers. The purpose of this Memorandum is to facilitate a coordinated response to
environmental contamination, physical safety concerns (open mine shafts, subsidence, and flooding), and
poor economic conditions at the Tar Creek area.
9.3 History of CERCLA Enforcement Activities
9.3.1 Operable Unit 1
The previous work at the Site under OU 1 addressed the on-Site surface water impacted by mine discharges
and the ground water on the Site. The EPA entered into a consent decree under Sections 107 and 122 of the
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Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), 42 U.S.C.§§ 9607
and 9622, with six mining companies (hereinafter the Companies), settling their liability for costs paid by
the United States in responding to the release or threat of release of hazardous substances as described in
the 1984 ROD (i.e., the costs related to OU1). In 1996, EPA settled its claims regarding the Site with
a bankrupt mining company which had the largest operation at the Site.
9.3.2 Operable Unit 2
On August 25, 1995, EPA issued a notice to the Companies or to their corporate successors (hereinafter the
Companies and their corporate successors are referred to as the Companies), and to the U.S. Department of
the Interior (DOI) which may be a potentially responsible party (PRP) under CERCLA's liability
provisions. In that notice, EPA gave the Companies and DOI the opportunity to conduct or finance the
removal activities described inEPA's August 15, 1995, Action Memorandum. The Action Memorandum
generally called for the excavation and on-Site disposal of lead-contaminated soil in High Access Areas
(HAAs) (HAAs are areas which children frequently visit such as playgrounds, day-cares, and parks). The
Companies and DOI did not undertake the removal; consequently, EPA proceeded with the removal action
for the HAAs on its own.
The EPA also issued a Special Notice to the Companies and to DOI on November 17, 1995. In the Special
Notice, EPA gave the Companies and DOI the opportunity to undertake the Remedial Investigation and
Feasibility Study (RI/FS) and remedial design (RD) for the remedial response action to address
contamination in the residential areas on the Site. The Companies and DOI did not undertake the
RI/FS/RD. As an alternative to RI/FS/RD, the Companies and DOI offered to perform a Community Health
Action and Monitoring Program (CHAMP). The CHAMP generally calls for monitoring the health of the
children in the contaminated residential areas, for thorough cleaning of homes in the contaminated area,
and for education of the residents regarding the avoidance of contamination. The EPA encouraged the
Companies and DOI to undertake the CHAMP, which they did; but, housecleaning and education do not
provide the sort of permanent remedy that the Superfund law requires. Consequently, EPA went forward
with RI/FS/RD on its own.
In order to address the imminent and substantial endangerment to human health posed by the lead-
contaminated soil in the residential areas on the Site, EPA issued a March 21, 1996, Action Memorandum
calling for a removal action to address the contamination. At the time the Action Memorandum was issued,
EPA sent a letter to the Companies and DOI notifying them that EPA was proceeding with the removal in
residential yards. In the letter, EPA told the Companies and DOI that EPA would not delay the removal
action in order to negotiate; however, EPA gave the Companies and DOI the opportunity to conduct or
finance the removal activities in progress. The Companies and DOI did not offer to take over the removal
actions.
9.3.3 Operable Unit 4
On December 9, 2003, the EPA signed an Administrative Order on Consent (AOC) with three Potentially
Responsible Parties (PRPs), including DOI, Blue Tee Corp., and Gold Fields Mining Corporation, to
conduct the Remedial Investigation/Feasibility Study (RI/FS) for OU4. Under the terms of the AOC, the
EPA prepared the risk assessments for OU4 based on data collected by the PRPs and EPA.
A three-phased Site Reconnaissance was conducted from March 29 to April 28, 2005. During the Site
Reconnaissance, field characterization of the mine and source materials was conducted and sampling sites
for the Remedial Investigation were selected with concurrence of EPA, the ODEQ, the Quapaw Tribe and
other participating organizations. Field sampling and investigations were conducted in May and concluded
in October 2005.
During the course of the investigation, EPA performed a pilot project consisting of several field studies
regarding sub-aqueous chat and fine tailings disposal, to supplement the Feasibility Study efforts. Under
this pilot, EPA injected the source material into flooded mine cavities to determine whether this could be a
cost-effective disposal technique. Characterization data collected prior to injection found conditions that
are favorable to this technique. The mine water was circumneutral with a pH between 6.0 and 6.6, the
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dissolved oxygen was very low (<50 |ig/L) and oxidation/reduction potential measurements were less than
-200 mV indicating an anaerobic environment. These types of conditions are conducive to a sulfate
reducing environment which would prevent the dissolution of metals from the chat or tailings that are
injected. A modified SPLP test was also conducted with the chat and fine tailings using mine water as the
extracting fluid to estimate the amount of metals that could be released.
Following the pilot injection, EPA found that the physical placement of chat and fine tailings in flooded
mine rooms does initially impact mine water; however, the data indicate that the mine water chemistry
rapidly begins to return to pre-placement conditions. Following placement of chat, the water chemistry of
the mine undergoes some increases in dissolved solids, largely from gypsum dissolution, and cadmium,
lead, and zinc during the first flush of the chat material. The principal factors that control the amounts of
trace elements entering the groundwater after chat placement are the abundance and availability of those
elements in the chat piles.
The first flush impact to the mine water is expected to flow away from the emplaced chat at a rate of
approximately 1 foot per day. The Boone Aquifer ground water model shows that for the EPA pilot sites
the water would eventually discharge at the Neosho River in a period of approximately 100 years. The
model does not account for sorption, dispersion, and diffusion of contaminants in the ground water. The
concentrations of the metals from the "first flush" would be expected to decrease as the water flows toward
the river; however, this scenario has not been fully evaluated.
In another ongoing pilot under the Remedial Investigation/Feasibility Study, DOI, with the cooperation of
the Quapaw Tribe, is promoting responsible chat sales, using Best Management Practices to reduce the
volume of millions of tons of mining waste. Both pilots, Indian-owned chat sales and the disposal of chat
in mine cavities, were response action alternatives considered in the Feasibility Study.
10.0 COMMUNITY PARTICIPATION
This decision document or ROD presents the EPA-selected remedial action for the chat piles, other mine
and mill waste and smelter waste areas of the Tar Creek Superfund Site, Ottawa County, Oklahoma chosen
in accordance with CERCLA, as amended, and, to the extent practicable, the National Contingency Plan
(NCP). The decision for the Site is based on the Administrative Record. The public participation
requirements of CERCLA Subsection 113(k)(2)(B)(i-v) and 117, 42 U.S.C. Subsection 9613(k)(2)(B)(iv)
and Section 9617, were met during the remedy selection process, as illustrated in the following discussion.
10.1 Community Involvement Plan
A Community Involvement Plan was prepared in February 1997. This plan describes the community
involvement activities that the EPA has undertaken, and will continue to undertake, during the remedial
activities planned for the Site.
10.2 Community Participation Activities
A Fact Sheet was distributed to the community in January 2004 to announce the beginning of the RI/FS.
The Fact Sheet informed the public of the completion of an Administrative Order on Consent with DOI and
two mining companies to implement the RI/FS for Operable Unit 4. EPA held a meeting on March 25,
2004, to discuss the RI/FS with the community.
The RI/FS and Proposed Plan for the Site were made available to the public in July 2007. These
documents can be found in the Administrative Record File for the Proposed Plan and in the information
repositories maintained with the ODEQ Central Records at the Oklahoma City Office, at the Miami Public
Library, and at EPA's offices in Dallas, Texas (document repository addresses appear below in this ROD).
The notice of the availability of these documents was published in the Miami News Record on July 28,
2007. The initial notice announced a 30-day public comment period ending August 30, 2007, but EPA
extended that comment period an additional 32 days, until October 1, 2007, at the request of the ODEQ.
EPA held a public meeting regarding the Proposed Plan on August 28, 2007, at Picher-Cardin High School.
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At this meeting, representatives from EPA answered questions about the Site and the remedial alternatives
outlined in the Proposed Plan. EPA response to the comments received during the public comment period
for the Proposed Plan is included in the Responsiveness Summary (Part 3), which is part of this ROD.
10.3 Technical Assistance Grant
A Technical Assistance Grant (TAG) was awarded to the Local Environmental Action Demanded (LEAD)
group in May 2001. The $50,000 grant was used by LEAD to hire a technical advisor and conduct
community outreach. The grant expired in May 2004 and the remaining balance was de-obligated.
10.4 Local Site Repository
The purpose of the local Site Repository is to provide the public a location near the affected community to
review and copy background and current information about the Site. The Site's repository is located near
the Site at:
Miami Public Library
200 North Main St
Miami, OK 74354
Telephone Number: 918-542-3064
and at the ODEQ office at:
Oklahoma Department of Environmental Quality
707 N. Robinson, 6th Floor Central Records
Oklahoma City, Oklahoma 73102
Telephone Number: 405-702-6145
There is also a Site Repository at EPA's Dallas Office located at:
EPA Region 6
1445 Ross Avenue
Dallas, TX, 75202-2733
214-665-6427 (Please call for an appointment if you would like to review the file)
11.0 SCOPE AND ROLE OF OPERABLE UNITS AND RESPONSE ACTION
The NCP, 40 CFR Section 300.5, defines an operable unit as a discrete action that comprises an
incremental step toward comprehensively addressing site problems. This discrete portion of a remedial
response manages migration, or eliminates or mitigates a release, threat of a release, or pathway of
exposure. The cleanup of a site can be divided into a number of operable units, depending on the
complexity of the problems associated with the site.
Due to the complex nature of contamination associated with the Tar Creek Site, remediation has been
handled through various removal response actions and remedial actions. The following five operable units
(OUs) have been designated at the Site: OU1 - surface water/ground water; OU2 - residential areas; OU3 -
Eagle-Picher Office Complex (abandoned mining chemicals); OU4 - Mine and Mill Waste, and Smelter
Waste and, OU5 - Sediments. A ROD was signed for OU1 in 1984 that applied to the surface water
degradation of Tar Creek and the threat of contamination to the drinking water. This remedy is in an after-
action monitoring phase. The ROD for OU2 was signed in 1997 and has applied to lead-contaminated soils
at over 2,295 properties. OU3 was a removal action that requires no further action, and OU5 is currently in
the early site characterization phase.
The remedial action addressed in this ROD, referred to as OU4, will address the parts of the Site (both
urban and rural) that are not currently used for residential purposes (except for the target relocation areas
discussed later in the paragraph) or which are sparsely used for residential purposes, where mine and mill
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wastes and smelter waste have been deposited, stored, disposed of, placed, or otherwise come to be located.
Areas where such material has come to be located will include without limitation chat covered haul roads
and non-operating railroad grades. OU4 will also address areas where mine and mill wastes and smelter
wastes have been moved by anthropogenic activities (e.g., where chat has been used as a driveway in a
rural area) or by natural actions including erosion (e.g., where chat has washed from a chat pile into a
stream). OU4 occupies approximately 40 square miles in the northern portion of Ottawa County,
Oklahoma, and is generally depicted in Figure 1. OU4 will also provide relocation for residences and
businesses in targeted areas including Picher, Cardin and Hockerville. The targeted relocation area is
generally described in Figure 9. OU4 will generally not address sediment, except where sediment is
incidentally addressed when chat is removed from in-stream or near-stream areas. OU4 will not address
ground water or surface water, except indirectly by eliminating some of the sources of ground water and
surface water contamination. OU4 will also generally not address contamination in streams that is due to
mine drainage. OU4 includes residential yards located in Ottawa County outside of city or town limits
except for those residential yards that have been addressed under OU2. OU4 includes all suitable areas in
very close proximity to the contamination necessary for implementation of the response action. OU4 also
includes Site areas selected for repositories for the disposal of source materials and contaminated soils and
sediments.
High concentrations of lead are addressed under the selected remedy identified in this ROD; however, the
concentrations of lead are not so high as to be several orders of magnitude above levels that allow for
unrestricted use and unlimited exposure. Therefore, the lead is not considered to be a principal threat under
the NCP; consequently, there is no expectation under the NCP that the lead be treated.
12.0 SITE CHARACTERISTICS
This section of the ROD provides a brief comprehensive overview of the Conceptual Site Model (CSM), a
site overview, a description of surface and subsurface features, sampling strategies used in the RI, known or
suspected sources of contamination, types of OU4 contamination, location of contamination and known or
potential routes of migration, and the geology and hydrology at the Site. Detailed information about the
Site's characteristics can be found in the RI Report (AATA 2005b).
12.1 Conceptual Site Model
The CSM for the Site identifies the sources of contamination, release mechanisms, pathways for
contaminant transport, the exposure route for contamination, and potential receptors. Figure 4 is a
representation of Site contaminant location and movement and potential routes of contaminant migration.
Human Health CSM
The CSM developed in the Baseline Human Health Risk Assessment (BHHRA) is presented in Figure 5.
The human health CSM is based on the following exposure pathways: dermal contact with or ingestion of
Source Material; dermal contact with or ingestion of surface soils; inhalation of dusts; ingestion of plant
tissue, fish tissue, animal tissue, or milk; and ingestion of shallow well water.
Receptors evaluated include residents and recreators (e.g., those who play on chat piles). The exposure
pathways are discussed further in Section 14.1.
Ecological Health CSM
The CSM developed in the Ecological Risk Assessment is presented in Figure 6. The ecological CSM
includes exposure of receptors to contaminants via direct contact, ingestion, inhalation and dietary transfer.
Receptors evaluated include mammalian and avian receptors, plants and the soil community. The exposure
pathways are discussed further in Section 14.2.
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12.2 Site Overview
The Site is a former lead and zinc mining area with the last known activities occurring in the 1970's. Since
the cessation of mining activities, the abandoned mines have filled with ground water from the Boone
Formation and most surficial equipment associated with mining and milling activities has been removed.
Early mining operations in the district were characterized by many local miners, each operating on 20- to
40-acre tracts of land. Each mine holding usually had its own mill. It has been estimated that in 1918 there
were 230 mills built or under construction at the Site.
In the 1920s, consolidation of milling began with one mill processing ore from several miners. By the
1930s, central mills were established, the largest being the Eagle-Picher Central Mill located between
Cardin and Commerce, Oklahoma. Many miners ceased their own milling operations in favor of selling
their ore production to one of the central mills or having their ore custom milled by these mills. This
movement of ore between mines and the central mills resulted in an extensive network of haul roads and
rail lines in the district.
12.3 Surface and Subsurface Features
The Site, part of the Tri-State Mining District, is situated within the Osage Plains section of the Central
Lowland Province in northeastern Oklahoma. The Osage Plains are generally characterized by a low relief,
rolling treeless prairie. The natural topography of the Site has been altered by mining activities. Numerous
piles of mine and mill wastes and collapsed structures associated with underground mines are present
within the Site (Luza, 1986).
The stratigraphic sequence within the Site consists of Paleozoic carbonate and clastic sedimentary rocks
which overlie a Precambrian granitic and igneous basement complex. The surficial formations at the Site
consist of Mississippian and Pennsylvanian units having a regional southwestward dip of approximately 20
to 30 feet per mile.
The lower to middle Mississippian Boone Formation is the host rock for the lead and zinc ore deposits in
the District. It consists primarily of limestone (sometimes oolitic), dolomite, and chert, along with lesser
quantities of sandstone and shale. The principal zinc mineralization present within the ores of the District
was zinc sulfide (ZnS), or sphalerite. Lead sulfide (PbS), or galena, was the primary lead mineralization
within the ores. These minerals were contained in a matrix consisting of dolomite, limestone, or chert.
Most of the zinc and lead mineralization that was the target of mining activities in the District was present
within the Boone Formation.
There are two principal aquifers in the region: the Boone (Mississippian) and Roubidoux (Cambro-
Ordovician) aquifers. The Boone Formation is the source of the shallow ground water and the Roubidoux
Formation is the source of deeper ground water in the area. A sequence of limestone, shale, and dolomite
strata, along with the upper portion of the Roubidoux formation forms a semi-confining unit or aquitard
separating the Boone aquifer from the Roubidoux aquifer.
Surface waters that drain from the Site flow into two principal regional watersheds: the Neosho River and
Spring River basins. Streams that drain the central and western portions of the Site include Tar, Lytle,
Quapaw, Garrett and Elm Creeks, and associated tributary drainages. Tar Creek drains the most intensively
mined areas of the Site. These streams flow south and drain into the Neosho River, about 1 mile southeast
of Miami, Oklahoma. These streams are typically underlain by Pennsylvania shale and as such are subject
to rapid runoff, flooding and intermittent flow. Surface drainages in the eastern portion of the Site flow into
the Spring River.
Land uses include agriculture, residential, light industry, commercial activities or businesses, and
recreational uses, with agriculture being the dominant land use. Approximately 3,700 acres of OU4 has
source material on the land surface as shown in Figure 2. Results from field investigations are presented
below.
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12.4 Sampling Strategy
Major data collection activities focused on source materials (i.e., chat, fine tailings and smelter wastes) and
affected media (i.e., affected-soils in the vicinity of source materials, yard soils in rural residences, ground
water from rural domestic wells). Pre-existing data was evaluated in the Data Gap Analysis Report (AATA
2004A) in order to utilize the large amount of data already collected at the Site. A sampling strategy was
then developed for the remedial investigation to collect sufficient information to characterize the nature and
extent of contamination.
High resolution aerial imagery of the Site was acquired in March 2004 to assist project GIS mapping and
volumetric calculations of mill residue accumulations. Field investigations were conducted over the period
of May to October, 2005.
12.5 Treatability Study
EPA began a review of potential technologies for injecting chat into the mine rooms at the Site in 2004.
This review led to the field implementation of a chat injection pilot study at the Montreal Mine. This pilot
study included drilling six borings into the flooded mine workings, conducting a sonar survey to evaluate
the size of the mine cavern in the vicinity of the borings, and chat injection using a variety of techniques.
Approximately 23,700 tons of chat was injected via gravity-feed, water-assisted gravity-feed and reverse
augering methods. The mine water was sampled before, during and after the injection to evaluate the
impact of the injection on the mine water. An additional 40,000 tons of chat was contained in an
innovative trench system that formed the road base for a private ranch road located in a previously
contaminated area on the Site. The soils from the trench were used to provide cover for 35 acres of land.
The pilot study was continued at the Tulsa Mine in order to evaluate the injection of fine tailings resulting
from the chat washing process. This study included drilling three borings into the mine and injecting
approximately 9000 tons of fine tailings.
EPA completed a third chat disposal pilot in September 2005 with the injection of 10,900 tons of chat into
the Craig underground mine cavern. This pilot focused on collecting additional information on the
movement of metals from the chat into the mine water to evaluate the long-term protectiveness of the
technology. The results of the pilots were positive, indicating that this technology should be considered as
a remedial component; however, longer-term sampling may be needed to fully understand the chemical fate
of the injected materials.
The pilot study approach was refined to evaluate the direct injection of fine tailings from an active chat
washing operation. This approach was first evaluated at the Tulsa Mine (Atlas Pile) and later expanded to
include LaSalle Mine (Ottawa Pile) and the Swift Mine (Sooner Pile). Each of these areas is included in an
on-going long-term monitoring program to assist in understanding the impacts to mine water when fine
tailings are injected.
12.6 Known or Suspected Sources of Contamination
The RI confirmed that chat and fine tailings found in piles, bases, chat haul roads, non-operating railroad
grades and tailings ponds are significant, high volume sources of contamination that occupy a large area at
the Site. Migration of contamination away from these source material areas has impacted surrounding soils
and surface water.
12.7 Types of Contamination and Affected Media
Mining and milling operations have resulted in the accumulation of large volumes of chat and fine tailings
found in piles, bases, haul roads, non-operating railroad grades and tailings ponds found at various
locations throughout OU4 of the Site. These mine and mill wastes contain elevated levels of lead, zinc and
cadmium. The media surrounding these accumulations were also evaluated including soils, surface water
and ground water.
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12.7.1 Chat Piles
Chat is a type of waste tailings produced by the gravity separation milling process once used in the Tri-
State Mining District. Chat consists of coarse gravel intermingled with other material such as medium to
fine sands, silt and clay. The highest concentrations of lead in chat are generally found in the fine tailings
material. A total of 83 chat piles covering a total area of 767.05 acres and with a total volume of 31.32
million cubic yards were identified. Some of these piles are over 100 feet high.
At the surface of undisturbed piles, the fine tailings settle into the chat accumulation and, as a result, the
surface of the pile consists predominately of the largest-sized particles. This physical process armors the
surface of the pile and limits the exposure and transport of the finer chat particles. In some piles, the chat is
cemented, forming a solidified mass that can have nearly vertical faces. This "armored" chat pile surface is
readily penetrated by individuals (e.g., recreators) who walk on the piles, and when the surface is
penetrated the finer particles are exposed.
A total of 168 chat samples taken one foot below the surface of 20 major chat piles were collected. The
samples were ground to pass through a #100-mesh sieve. The concentration of cadmium in the chat ranged
from 43.1 milligrams per kilogram (mg/kg) or parts per million (ppm) to 199.0 mg/kg with an average of
94.0 mg/kg. Lead in these samples ranged from 210 mg/kg to 4,980 mg/kg with an average concentration
of 1,461 mg/kg. Zinc ranged from 10,200 mg/kg to 40,300 mg/kg with an average concentration of 23,790
mg/kg.
Fourteen chat samples were also taken at depths ranging from zero inches to one inch below the surface at
selected chat piles. Only the portion of these samples that would pass through a #60 mesh sieve without
grinding was analyzed. This was done to provide the type of data required for the BHHRA. Lead
concentrations in these 14 samples ranged from 355 to 1,730 mg/kg; cadmium from 40 to 133 mg/kg; and
zinc from 8,990 to 29,900 mg/kg.
12.7.2 Chat Bases
A chat base is an area that was once occupied by a chat pile. Chat bases can be covered with vegetation or
are sometimes found bare. There are 243 chat bases identified at the Site, covering a total area of 2,079.26
acres.
Some bases have been cleared thoroughly with just a few inches of chat remaining, while others still
contain chat several feet thick in or on a portion of the footprint of the former pile. The average thickness
of all chat bases was estimated to be about 2 ft. The total volume of chat remaining in the chat bases at the
Site is estimated to be 6.71 million cubic yards.
A total of 22 samples from six chat bases were collected. The samples were ground to pass through a
#100-mesh sieve. The concentration of cadmium in the chat bases ranged from 51.0 mg/kg to 151.0 mg/kg
with an average of 96.2 mg/kg; lead concentrations ranged from 650 mg/kg to 3,020 mg/kg with an average
concentration of 1,863 mg/kg; and zinc concentrations ranged from 9,520 mg/kg to 40,300 mg/kg with an
average of 33,600 mg/kg.
12.7.3 Fine Tailings
Two types of fine tailings were identified: 1) fine tailings generated as a waste during washing of chat, and
2) flotation tailings generated during the metal extraction process or milling. A total of 63 tailings ponds
covering a total area of 820.47 acres were defined. Based on field drilling and mapping, it was estimated
there were 7.21 million cubic yards of washed fine tailings and 1.95 million cubic yards of flotation tailings
at the Site.
EPA collected and chemically analyzed 101 samples of fine tailings from chat washing ("washed fines").
EPA also collected and analyzed 55 samples of flotation tailings. The samples were collected from ten
major tailings ponds. The samples were composited over their respective depth interval (depth-integrated
samples) and were not sieved.
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The concentration of cadmium in the washed fine tailings ranged from 10.0 mg/kg to 320.0 mg/kg with an
average concentration of 79.7 mg/kg; lead concentrations ranged from 220 mg/kg to 26,600 mg/kg with an
average concentration of 3,658 mg/kg; and zinc concentrations ranged from 1,730 mg/kg to 70,000 mg/kg
with an average concentration of 15,964 mg/kg.
The concentration of cadmium in the flotation tailings ranged from 26.3 mg/kg to 450.0 mg/kg with an
average concentration of 133.0 mg/kg; lead concentrations ranged from 1,130 mg/kg to 17,800 mg/kg with
an average concentration of 5,694 mg/kg; and zinc concentrations ranged from 4,690 mg/kg to 103,000
mg/kg with an average concentration of 29,842 mg/kg. With few exceptions, flotation tailings contain
higher cadmium, lead, and zinc concentrations than washed fine tailings.
Ten samples of fine tailings were also collected from the Site at depths that were within one inch of the
surface of these same fine tailings deposits described in the preceding paragraphs. These samples were
sieved using a small mesh size #60 and analyzed as part of EPA's human health risk assessment. Metal
concentrations found in these shallow tailings samples were in the same range as those reported from the
depth-integrated washed fine tailings samples.
12.7.4 Smelter Wastes
One small lead smelter, the former Ottawa smelter located south of Hockerville, was investigated. It is the
only smelter known to have operated on the Site. Though the smelter had a reported processing capacity of
140 tons per day, it did not operate at capacity. The smelter was abandoned and dismantled in the early
1930s.
The primary smelter wastes found on OU4 were slag and clinker. Also present at the smelter area was
rubble from the former smelter including brick and concrete blocks, scrap metal, and retort remnants. No
flux was identified at this location. The total area containing smelter wastes was estimated to be 2.29 acres.
Within these 2.29 acres, smelter wastes occurred as scattered small mounds five to ten feet in diameter and
six to fourteen inches in height. The thickness of the smelter wastes was determined by the excavation of
test pits. More than 20 test pits were dug within the area determined to contain smelter wastes. The
thickness of the waste was found to range from 0 to 14 inches within this mapped area. Field
characterization of the smelter wastes indicated that slag made up a majority of the waste material present
(75%) with minor amounts of clinker (20%) and rubble (5%).
Five grab samples of smelter wastes were collected. Cadmium and zinc concentrations in the smelter
wastes were found to be comparable to those in the source materials at the Site. The concentration of lead
in the smelter waste (2,800 to 80,000 mg/kg) was found to be considerably higher than that in the other
source materials at the Site. This is consistent with the fact that the former smelter was a lead smelter.
12.7.5 Transition Zone Soils
Transition zone soils are located adjacent to (or underneath) source materials. Transition zone soils have
elevated concentrations of chemicals of concern when compared to natural background concentrations. In
transition zone soils, the elevated concentrations of chemicals of concern are due primarily to mechanical
redistribution of source materials and to a lesser extent, water and wind dispersion.
A total of 360 transition zone soil samples were collected in the vicinity of five isolated mill waste
accumulations. Transition zone soil samples at 0 to 1-inch, 6-inch, 12-inch, and 24-inch depths below
ground surface (bgs) were collected. Samples from all of these depths were collected at intervals of 0, 5,
10, 20, 40, 70, 120, 200, and 300 feet measured outward from each of the accumulations along selected
transects. Evaluation of the laboratory analytical results indicated there is no clear trend in the average
concentration of cadmium, lead, or zinc in surface soils relative to distance from mill waste accumulations.
However, in some instances, the concentrations of metals appear to decrease with distance and depth.
Contamination source material was occasionally encountered in instances where a decrease in metals
concentration was not the case.
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The observed variation of metals concentrations in transition zone soils is probably caused primarily by the
extensive processing, transport, and use of chat throughout the Site. In addition to variations in soil
concentrations of contaminants of concern due to the transport and use of chat, anthropogenic activities
such as tilling and grading have covered or replaced contaminated materials in some areas. As a result of
the tilling and grading, soil concentrations of contaminants of concern in these areas are now generally at or
near background concentrations.
For the purpose of the Feasibility Study, EPA estimated the aerial extent and volume of affected soils that
contain concentrations of lead that exceed the human health risk-based remediation goal of 500 mg/kg
established under the OU2 Record of Decision for Tar Creek Residential Areas. The estimate included the
soils within a 50-foot wide transition zone plus soils from historical roads and non-operating railroads. EPA
estimated that there are 1,162 acres on OU4 that contain soil lead concentrations that exceed 500 mg/kg.
The estimated volume of this contaminated soil is 1,360,000 cubic yards (yd3). To make this calculation,
lead-contaminated transition zone soil was assumed to extend 50 feet beyond the known edge of chat piles,
chat bases, and tailings.
12.7.6 Smelter Waste Affected Soils
Smelter waste affected soils are those soils in the immediate vicinity of the former Ottawa smelter located
near Hockerville. These soils have elevated concentrations of contaminants of concern when compared to
background soils. Thirty-five surface soil samples were collected within one inch of the surface at
locations surrounding the former Ottawa lead smelter. Soil lead concentrations were significantly elevated
near the former smelter, with concentrations within 200 feet of the former smelter ranging from 1,560
mg/kg to 16,800 mg/kg. Soil lead concentrations decreased to below 500 mg/kg just south of the area
affected by smelter wastes and rapidly approached background levels further south. Based on the human
health risk-based remediation goal of 500 mg/kg for lead, a 500-foot radius (centered on the former smelter
location) and a 6-inch depth of contamination were selected to estimate the aerial extent and volume of
smelter waste affected soils. Using these estimates, EPA estimated the area of smelter waste affected soils
to be 18.0 acres and EPA estimated the volume of the contaminated soil, with concentrations that exceed
500 mg/kg to be 14,537 yd3.
12.7.7 Rural Residence Yard Soils
As part of the remedial investigation, a total of 77 yards at rural residences were studied. These yards had
not been previously investigated. EPA obtained access to 47 of these residences. EPA collected a total of
366 soil samples. Cadmium concentrations in the samples ranged from less than 0.5 mg/kg to 53.8 mg/kg,
with an overall average concentration of 4.4 mg/kg. Lead concentrations ranged from less than 0.05 mg/kg
to 14,400 mg/kg, with an overall average concentration of 201 mg/kg. Zinc concentrations ranged from less
than 1 mg/kg to 10,700 mg/kg, with an overall average concentration of 692 mg/kg. Within an individual
residential yard, metal concentrations may vary widely, but to ensure that concentration estimates for soil in
a given yard were within statistically significant confidence levels, EPA took composite samples.
Soil lead concentrations exceeded the remediation goal of 500 mg/kg in one or more composite samples at
five of the rural residences investigated. EPA took indoor dust samples at four of these five residences
where we found elevated soil lead concentrations. The concentration of lead in the house dust ranged from
less than the detection limit of the instruments used to 360 mg/kg, with the concentration being below the
detection limit at two of the four residences sampled.
Yard soils at the remaining 42 rural residences investigated showed a similar range of metal concentrations
as the background soils at the Site. Since, indoor dust lead concentrations correlate to outdoor soil lead
concentrations, by remediating the yards, the indoor dust concentrations will be reduced. One of the five
residential properties with elevated lead concentrations in yard soils was remediated by EPA in November
2005. EPA expedited the action on this property in response to significantly elevated lead concentrations
that were detected on the property.
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12.7.8 Ground water
Thirteen rural residences are using ground water from the shallow aquifer for domestic purposes. These
private wells were sampled. Two samples, one first flush (a minimum of 8 hours of no flow time) and one
flushed (sampled after 3 minutes of continuous flow) were collected from each well. Water from all the
wells investigated was neutral to slightly alkaline (pH 7.11 to 7.79) with moderate mineralization (Total
Dissolved Solids 160 to 480 milligrams per liter [mg/L]). Eleven of the thirteen wells met the federal
health-based standard for lead in drinking water (0.015 mg/L), while concentrations of lead in water drawn
from two wells exceeded the standard. No other federal standards were exceeded in any of the wells
sampled.
12.7.9 Surface Water
In order to determine whether chat pile seepage was contaminating surface water, the USGS studied flow,
water quality, and metal loading from seepage. USGS studied seepage from the Western (John Beaver)
chat pile and from the Admiralty chat pile after a rainfall event. Metal loads were calculated from the
Admiralty chat pile; however, they could not be calculated at the Western pile due to low flow from the
pile during the sampling period.
The USGS report calculated loadings of cadmium, iron, lead and zinc in Tar Creek mine outflow and in
leachate from chat piles. The data show that chat leachate accounts for 68% of the cadmium, 1% of the
iron, 77% of the dissolved lead and 19% of the zinc in Tar Creek surface water at the study area. The mine
outflow accounts for 99% of the iron and 29% of the zinc in Tar Creek surface water at the study area. The
majority of the zinc loading (52%) in Tar Creek originates from Lytle Creek. The source of zinc in Lytle
Creek was not identified by the study.
EPA concludes from the data described in the preceding paragraph that the chat piles are a significant
source of the hazardous substances (cadmium, lead, zinc) in Tar Creek. That is, it is clear that chat pile
leachate that follows a rain event is a significant source of cadmium, lead, and zinc in Tar Creek.
12.7.10 Biota
Surface water samples, pond sediment samples, aquatic macrophytes, and benthic macroinvertebrates were
collected from three flooded tailings ponds and analyzed. The flooded tailings ponds displayed very low
densities of aquatic organisms which may indicate that contamination from OU4 mining and milling waste
has caused adverse ecological impacts.
12.7.11 Edible Plants
EPA collected samples of three edible plant species (asparagus, willow, and cattail) in support of the risk
assessments. A total of 57 plants were sampled. Four samples were collected from each plant: washed
roots, unwashed roots, washed leaves, and unwashed leaves for a total of 228 samples. In addition, a co-
located soil sample was collected for each plant. In all three plant types, concentrations of contaminants of
concern in roots exceeded stalk (aboveground) concentrations. The maximum cadmium concentration was
detected in unwashed cattail root (249 mg/kg). The maximum lead concentration in unwashed roots was
highest in cattails (2,759 mg/kg). The maximum zinc concentration was detected in unwashed willow roots
at 13,202 mg/kg. The Human Health Risk Assessment found that these levels of zinc and cadmium in
edible plants exceeded a hazard index of 1, which is predictive of non-carcinogenic health effects.
12.8 Locations of Contamination and Known or Potential Routes of
Migration
As shown in Figure 2, Source Materials are located throughout the Site. The locations of Source Materials
are catalogued in an extensive GIS mapping system that was developed using current high-resolution aerial
photography which was compared to historic aerial photography and mining maps.
The lateral and vertical extent of contamination was evaluated on select areas as part of the RI to verily the
presence of Source Materials and to evaluate the potential for migration of contaminants from these areas.
The RI found that contaminants from Source Materials can migrate to surrounding soils and surface waters.
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13.0 CURRENT AND POTENTIAL FUTURE LAND AND WATER USES
This section discusses the current and reasonably anticipated future land uses and current and potential
beneficial ground and surface water uses at the Site. This information forms the basis for reasonable
exposure assessment assumptions and risk characterization conclusions presented in Section 14.
13.1 Current and Potential Future Land Uses
Much of the land at the Site remains undeveloped. Beside the land surface covered by mine and mill
residues, land use within the rural areas of OU4 consists primarily of:
Residential - homes and churches;
Agricultural- crop farming and pasture grazing;
Industrial - chat processing plants, asphalt plant, sand and gravel plant, barium plant and fertilizer
plant; and
Commercial -small businesses and retail shops.
Figures 7 and 8 show the land use within OU4. The agriculture classification used in these figures includes
areas used to grow row crops and areas used as pastures (grazing land). The agricultural classification is
the dominant land use and comprises approximately 17,730 acres (68.3 percent) of the land area ofOU4.
Mine and mill residues, and smelter wastes cover approximately 3,670 acres (14.2 percent) of OU4.
There are 232 rural residences identified within OU4 and these occur scattered over the unincorporated
portions of the Site. As shown in Figure 8, nearly 75% (170 out of 232) of the rural residences are located
in the eastern half of the Site outside of the major mining areas.
Future land uses are not expected to change, and agricultural uses and rural residential uses will remain
dominant on the Site. A change is expected for residential and commercial settings in Picher, Cardin and
Hockerville which are included in the voluntary relocation. Future land use of the properties that are
purchased as part of the voluntary relocation effort being conducted by the LICRAT is stipulated in
LICRAT's enabling legislation. A restriction is required for these properties which shall run with the land
on the property deed. The restriction will contain a provision that the property may not be occupied by
children six years of age and younger until the State formally determines that the area is safe for children of
such an age.
Under this ROD, EPA will not take an interest in any real estate as part of the relocation elements of this
ROD. Instead, EPA will provide funds to the LICRAT to use for relocation of residents in targeted areas.
The State has also agreed that the ODEQ will file a recordable notice of remediation or related action,
including an easement, on each property acquired by LICRAT. Pursuant to the State's authority under
Oklahoma Statutes 27A § 2-7-123(B) the recordable notice will identify all engineering controls used to
ensure the effectiveness of the remediation and will contain prohibitions against engaging in any activities
that cause or could cause damage to the remediation or the engineering controls, or recontamination of the
soil or groundwater as well as restrictions on land use or other activities that are incompatible_with the
remedy selected in this ROD.
The Quapaw Tribe adopted a zoning ordinance in 2007 that established planned uses of Quapaw lands.
The goal of the zoning ordinance is to preserve all future uses of the land including residential, agricultural,
conservation, forestry, industrial and commercial.
13.2 Current and Potential Future Ground Water Uses
Ground water is used as a source of drinking water at the Site, and was addressed under OU1. The deeper
Roubidoux aquifer is used by the municipalities as a source of drinking water and the shallow aquifer in the
Boone Formation is used as a source of drinking water mainly by rural residents. The wells belonging to
rural residents that use the Boone Formation as a source of drinking water were sampled at the tap during
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the RI. Use of the Boone Formation as a future ground water source is expected to continue in the rural
areas.
14.0 SUMMARY OF SITE RISKS
The BHHRA estimates what human health risks OU4 poses if no action is taken. It provides the basis for
taking action at OU4 and it identifies the chemicals of concern (COCs) and exposure pathways that need to
be addressed by the remedial action. The BHHRA evaluates the baseline potential risk that might be
experienced by human receptors coming into contact with contaminated air, soil, sediment, surface water,
ground water, and fish tissue. This section of the ROD summarizes the results of the BHHRA. This
BHHRA followed a four step process:
14.1 Summary of Baseline Human Health Risk Assessment
The BHHRA estimates what human health risks the Site poses if no action were taken. It provides the basis
for taking action at this Site and identifies the contaminants and exposure pathways that need to be
addressed by the remedial action. The BHHRA evaluates the baseline potential risk that might be
experienced by human receptors coming into contact with contaminated air, soil, sediment, surface water,
ground water, and fish tissue. A summary of the risk is discussed below in Section 14.3. This section of
the ROD summarizes the results of the BHHRA. This BHHRA followed a four step process:
a. Hazard identification (Identification of COCs),
b. Exposure assessment,
c. Toxicity assessment, and
d. Risk characterization.
14.1.1 Identification of Chemicals of Concern
Table 1 presents the COCs and Exposure Point Concentrations (EPCs) for each of the COCs detected in
chat and fine tailings, surface soil, ground water, and plants. The EPC is the average contaminant
concentration over the exposure period used to estimate the exposure and risk or hazard from each COC.
The COCs were identified following a screening of all of the analytical results from the RI and include
lead, cadmium and zinc.
The table also provides the range in concentrations of the COCs detected in each of these media, the
frequency of detection (i.e., the number of times the COC in question was detected in the samples collected
at the Site), and an explanation as to how the EPC was derived.
14.1.2 Exposure Assessment
Exposure refers to the potential contact of an individual (the receptor) with a contaminant. The exposure
assessment evaluates the magnitude, frequency, duration, and route of potential exposure. This section
describes which populations may be exposed, the exposure pathways, and the level of exposure to the
contaminants present. A complete discussion of all the scenarios and exposure pathways is presented in the
BHHRA.
The objective of the exposure assessment is to evaluate potential current and future human exposures to
COCs in all media of concern - air, soil sediment, surface water, ground water, and animal tissue. The
current and potential future human receptors were determined by the Site's configuration, land and water
use, and activity patterns. Receptors were identified for both current and potential future Site conditions.
A complete discussion of all the scenarios and exposure pathways is presented in Section 3 of the BHHRA.
As depicted in the Conceptual Site Model (CSM), the following pathways for current and future receptors
were considered complete:
• General public child resident - Ingestion of surface soil, ingestion of drinking water, and inhalation
of ambient air
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• General public adult resident - Ingestion of surface soil, ingestion of drinking water, and inhalation
of ambient air
• Native American child resident - Ingestion of surface soil, ingestion of drinking water, inhalation of
ambient air, and ingestion of dairy milk
• Native American adult resident - Ingestion of surface soil, ingestion of drinking water, inhalation of
ambient air, and ingestion of fish, beef, edible plants, aquatic life (such as mussels, crawfish), and
small game animals
• Recreator - Ingestion of surface waste materials (such as material found in chat pile and mill pond
material)
Exposure route, receptor, receptor-specific assumptions, and exposure point concentrations are presented in
Tables 1 through 4. These exposure routes were evaluated to determine human health risk related to OU4.
14.1.3 Toxicity Assessment
Toxicity assessment is accomplished in two steps: hazard identification and dose-response assessment.
Hazard identification is the process of determining whether exposure to a chemical is associated with a
particular adverse health effect and involves characterizing the nature and strength of the evidence of
causation. The dose-response assessment is the process of predicting a relationship between the dose
received and the incidence of adverse health effects in the exposed population. From this quantitative dose-
response relationship, toxicity values are derived that can be used to estimate the potential for adverse
effects as a function of potential human exposure to the chemical of concern.
For noncancer outcomes, a chronic reference dose (RfD) is derived from the no-observed adverse-effect
level (NOAEL) or lowest-observed-adverse-effect level (LOAEL) in animals or humans. RfDs are derived
by dividing the NOAEL or LOAEL by an uncertainty factor that represents a combination of various
sources of uncertainty associated with the database for that particular chemical. EPA's IRIS database and
National Center for Environmental Assessment (NCEA) served as the source of RfDs for the COCs at Tar
Creek, except for lead (discussed below), for which there is no IRIS RfD and for which other sources of
toxicity data were used.
Dermal RfDs are not available in IRIS, Provisional Peer Reviewed Toxicity Values (PPRTVs), or HEAST.
Equations presented in EPA guidance (EPA, 1989) were used to calculate dermal RfDs for cadmium and
zinc. An inhalation reference concentration (RfC) was not available for zinc. Note that cadmium also has
potential cancer effects and has its own IRIS slope factor (SF) via the inhalation pathway.
Risk assessments for lead differ from those for other noncarcinogens in that they assess the risk of
elevations in blood lead levels (BLLs), as elevated BLLs have been directly related to adverse outcomes in
adults and children. In studies conducted around the world, elevated BLLs have been found to be
associated with a variety of adverse health effects including neurocognitive and impaired behavioral
development in young children.
For cancer outcomes, the dose-response information is condensed into a SF, in units of (mg/kg-dav)
which expresses excess lifetime cancer risk (ELCR) as a function of (lifetime average) daily dose. EPA
maintains an online database, IRIS (EPA, 2005d), which contains SFs that are based on the current weight
of toxicological evidence. Of the three COCs identified at Tar Creek, only cadmium was evaluated for
carcinogenic risk since it was the only identified potential carcinogen.
Tables 5 and 6 show the cancer and the non-cancer toxicity values, respectively, for the COCs that are the
major risk contributors at the Site. For complete information on the toxicity of the COCs, see the BHHRA.
14.1.4 Risk Characterization
The risk characterization section of the ROD summarizes and combines outputs of the exposure and
toxicity assessments to characterize baseline risk at the Site. Baseline risks are those risks and hazards that
the Site poses if no action were taken.
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Carcinogens
For carcinogens, risks are generally expressed as the incremental probability of an individual's developing
cancer over a lifetime as a result of exposure to the carcinogen. Excess lifetime cancer risk is calculated
using the following equation:
Risk = CDI x SF
where:
Risk = a unitless probability (e.g., 2 x 10-s) of an individual's developing cancer
CDI = chronic daily intake averaged over 70 years (mg/kg-day)
SF = slope factor, expressed as (mg/kg-day)-l.
An excess lifetime cancer risk of lxlO"6 indicates that an individual experiencing the reasonable maximum
exposure estimate has a 1 in 1,000,000 chance of developing cancer as a result of site-related exposure.
This is referred to as an "excess lifetime cancer risk" because it would be in addition to the risks of cancer
individuals face from other causes such as smoking or exposure to too much sun. The chance of an
American individual developing cancer from all other causes has been estimated to be as high as one in
three. EPA's generally acceptable risk range for site-related exposures is lxlO"4 to lxlO"6.
Noncarcinogens
The potential for noncarcinogenic effects is evaluated by comparing an exposure level over a specified time
period (e.g., life-time) with a RfD derived for a similar exposure period. A RfD represents a level that an
individual may be exposed to that is not expected to cause any deleterious effect. The ratio of exposure to
toxicity is called a hazard quotient (HQ). A HQ less than 1 indicates that a receptor's dose of a single
contaminant is less than the RfD, and that toxic noncarcinogenic effects from that chemical are unlikely.
The Hazard Index (HI) is generated by adding the HQs for all contaminants of concern that affect the same
target organ (e.g., liver) or that act through the same mechanism of action within a medium or across all
media to which a given individual may reasonably be exposed. A HI less than 1 indicates that, based on the
sum of all HQ's from different contaminants and exposure routes, toxic noncarcinogenic effects from all
contaminants are unlikely. A HI greater than 1 indicates that site-related exposures may present a risk to
human health.
The HQ is calculated as follows:
Non-cancer HQ = CDI/RfD
where:
CDI = Chronic daily intake
RfD = reference dose.
CDI and RfD are expressed in the same units and represent the same exposure period (i.e., chronic,
subchronic, or short-term).
Lead
Risk assessments for lead rely on predicted BLLs in a community, as BLLs have been directly related to
adverse outcomes in adults and children. Because vast quantities of lead have been distributed throughout
Tar Creek due to historical mining-related activities, the BHHRA devoted substantial effort to
characterizing the risks of lead toxicity. The Integrated Exposure Uptake Biokinetic (IEUBK) model was
used to estimate risks to children from lead exposure from soil and other media. The EPA's Adult Lead
Methodology (ALM) was used to evaluate residential adult and adolescent recreator exposures to lead in
soil.
At sites like Tar Creek, EPA policies seek to protect the health of the most vulnerable populations, namely
children and women of childbearing age. EPA strives to reduce soil lead levels so that no child or fetus of a
woman of childbearing age would have more than a 5 percent chance of exceeding a BLL of 10 (ig/dL.
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14.1.4.1 Risk Estimations
Potential ELCRs, His, and BLLs were calculated using RME assumptions for the general public, Native
American residents, and recreators for the exposure pathways. The summaries of these risk estimates are
presented in Tables 7 through 9.
14.1.5 Uncertainty Analysis
Some level of uncertainty is introduced into the risk characterization process every time an assumption is
made. In regulatory risk assessment, the methodology dictates that assumptions err on the side of
overestimating potential exposure and risk. The effect of using numerous assumptions that each
overestimated potential exposure provides a conservative estimate of potential risk.
14.1.5.1 Data Evaluation Uncertainty
The purpose of data evaluation is to determine which chemicals are present at the site at concentrations
requiring evaluation in the risk assessment. Uncertainty with respect to data evaluation can arise from many
sources, such as the quality of the data used to characterize the site and the process used to select data
included in the risk assessment. Analytical parameters were selected based upon knowledge of historical
site activities (mining). There is some uncertainty associated with the size of the Tar Creek study area and
the limited number of samples that were collected from the various media. However, the data are expected
to represent the range of concentrations that may be contacted in the various media within the Tar Creek
area. Use of this data is not expected to affect the conclusions of the BHHRA significantly, but adds
uncertainty to the locations that may warrant risk management.
14.1.5.2 Exposure Assessment Uncertainty
Significant uncertainty exists in assumptions used to calculate chemical intakes from exposure to various
media (e.g., rate of ingestion, frequency and duration of exposure, absorption efficiency). Conservative
exposure factors (i.e., health-protective) are used when available information is limited. This may result in
an overestimation of risk.
There are uncertainties in the modeling used to estimate lead exposures by adolescent recreators. The more
significant uncertainties include the use of the ALM for an adolescent population, the potential for a lead
higher absorption factor (i.e., up to 30%), the potential for a higher soil ingestion rate (e.g., 200 mg/day),
the potential for a lower exposure frequency (e.g., 78 days/year), and a potential lower baseline BLL than
that assumed in the risk calculations. However, a potentially higher absorption factor and lower baseline
BLL are likely to cancel each other out in the lead exposure calculations.
The bioavailability of lead in soil at the Tar Creek site was not measured. However, the bioavailability of
lead in soil was evaluated at the Jasper County, Missouri Superfund Site, a similar site to Tar Creek OU4 in
terms of waste sources and environmental conditions. Three soil samples from the site (composites from
different areas of the site) were used in a study to measure the gastrointestinal absorption of lead from soil.
Concentrations in the three soil samples ranged from 4,050 to 10,800 ppm lead. The amount of lead
absorbed by each animal was evaluated by measuring the amount of lead in the blood, liver, kidney, and
bone. Results indicate absolute bioavailability in the range of 29 to 40 percent. Therefore, the default
absolute bioavailability factor of 30% used in the IEUBK model seems to fall within the range of the actual
bioavailability for the site soil and, as such, the assumed bioavailability does not over- or under- estimate
site risk.
14.1.5.3 Toxicity Assessment Uncertainty
Dermal toxicity values are not available in the standard toxicity references. Therefore, dermal toxicity
values were calculated using oral toxicity values and available oral absorption efficiencies for the study
animals for which oral RfDs were derived. Depending on the quality of the data available for absorption
efficiencies, and depending on whether or not dermal exposures result in the same type of target effect (as
observed in the oral study), this may result in underestimation or overestimation of risk.
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14.1.5.4 Risk Characterization Uncertainty
Generally, the goal of a baseline HHRA is to estimate an upper-bound, but reasonable, potential risk. Such
an upper-bound estimate can be derived in several ways, depending on how conservative one wants the
final estimate. In the baseline HHRA, several upper-bound assumptions and numerous exposure pathways
were combined to estimate potential risks.
Most of the assumptions about exposure and toxicity used in the BHHRAs are representative of statistical
upper-bounds or even maximums for each parameter. The result of combining several such upper-bound
assumptions is that the final estimate of potential exposure or potential risk is conservative.
14.2 Summary of Ecological Risk Assessment
In order to determine ecological risk at the Site, a conservative assessment was performed using a two
tiered approach: an initial screening level ecological risk assessment and a conservative evaluation using
additional plant and fish tissue in combination with information from the scientific literature and from the
Baseline Ecological Risk Assessment that EPA developed for a Superfund Site in nearby Cherokee County,
Kansas. The overall conclusions regarding the risk drivers for terrestrial soil and plant communities and for
terrestrial/riparian mammal and bird communities show high model-calculated risk from exposure to
cadmium, lead, selenium, and zinc. Food chain models also frequently, but less often, resulted in high
model-calculated risk to these communities from exposure to Site-related copper and nickel. The primary
risk drivers (cadmium, lead, and zinc) which had maximum measured concentrations in chat, fine tailings,
soil and sediment on-site are high enough to present risk to fauna through incidental ingestion of
soil/sediment alone. In addition, there would undoubtedly be some additional fauna exposure via dietary
transfer. Dietary transfer is exposure to contaminants through consumption of other animals or plants that
accumulated contaminants either through direct exposure or through consumption of other animals or
plants that had direct exposure to contaminants. There is also concern regarding the potential risk for
exposure of waterfowl to high concentrations of zinc. In several cases for avian receptors (waterfowl),
calculated risk was greatest for zinc.
In lieu of conducting a Baseline Ecological Risk Assessment for OU4, the Ecological Remediation Goals
developed by EPA for the nearby Cherokee County, Kansas, site (another site with mining and milling
related contamination) were considered. The Cherokee County Superfund Site and Tar Creek OU4
Superfund Site are both part of the same Tri-State Mining District (Kansas, Missouri and Oklahoma). The
two sites are also in the same ecological sub region and province - the Osage Plains section of the Central
Lowland Province. Mining operations at both of these Sites used the ore deposits of the Picher Mining
Field for the production of lead and zinc, and were separated only by the political boundary - the Kansas-
Oklahoma state line which has no effect on ecosystems. Mining operations of the Picher field ore deposits
resulted in cadmium, lead and zinc being the primary risk driver for both sites and the background
concentrations of these metals are comparable between both of the Cherokee County Superfund Site and
the Tar Creek OU4 Superfund Site. There are other similarities between the sites including climate,
topography, flora and fauna which make our use of the Cherokee County site study appropriate.
The remediation goals for soil at the Cherokee County site were developed based on the exposure of
terrestrial wildlife to contaminated soil. The pathway that frequently drives ecological risk assessments at
mining sites is the intake of soil by ground feeding insectivores, also known as vermivores. Vermivores are
sensitive species for two reasons. First, there is a relatively higher percentage of soil (hence metals) in their
diets. Second, the soil invertebrates the vermivores consume have a relatively higher metal concentration in
their tissue compared to food sources uses by other species. Generally, there are two species that represent
vermivores well, and they are the short-tailed shrew (class mammalia) and the American woodcock (class
aves). Remediation goals that are protective for vermivores should also be protective of other less sensitive
guilds of terrestrial wildlife.
The Cherokee County analysis recommended a range of values for cadmium, lead and zinc in soil that
would be protective for exposed terrestrial wildlife. The recommended soil preliminary remediation goals
were given as a range:
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Cadmium
Lead
Zinc
1.0 - 10.0 mg/kg
377- 1175 mg/kg
156 - 1076 mg/kg
EPA used this analysis in its selection of the remediation goal for the Cherokee County, Kansas, site in the
Amended Record of Decision for that site dated September 29, 2006. The specific levels selected for the
Cherokee County site were 10.0 mg/kg cadmium, 400 mg/kg lead and 1100 mg/kg zinc. Based on
similarities between Cherokee County and the Tar Creek Site, EPA has selected 10.0 mg/kg cadmium, 500
mg/kg lead and 1100 mg/kg zinc as the soil Remediation Goals to address ecological risks at the Site. The
remediation goal for lead is higher at the Tar Creek Site than Cherokee County; however, it is still on the
lower end of the range recommended in the Cherokee County analysis. The remediation goal of 500 mg/kg
lead was selected in order to be consistent with the remediation goal established in the OU2 ROD for Tar
Creek Residential Areas for the protection of human health. EPA selected 400 mg/kg at the lower end of
the range for lead developed at the Cherokee County site due to concerns regarding future sediment
recontamination. However, EPA proposes to implement erosion controls to limit future sediment transport
at Tar Creek, and therefore, has selected 500 mg/kg. This 500 mg/kg soil lead remediation goal is also
applicable to Source Material at the Tar Creek Site. Source material, including chat, fine tailings and
smelter wastes, is a source of contamination to the soil at the Site.
14.3 Basis for Remedial Action
The response action selected in this ROD is necessary to protect the public health or welfare and the
environment from actual or threatened releases of hazardous substances into the environment.
Human Health Risk
The primary human exposure at OU4 occurs through incidental ingestion associated with normal hand to
mouth contact after contact with soil and source materials. Contaminated water drawn from certain rural
domestic wells also poses a risk. Exposure through the ambient air inhalation route of intake poses no
health risk. The Baseline Human Health Risk Assessment identified lead as the primary chemical of
concern and determined that addressing exposure from lead will also be protective for cadmium and zinc
exposures.
Risk to Children Living in Residences with Lead Contaminated Yards
EPA has various tools that it can use to evaluate risk posed by lead, but, after considering various other
methods, EPA decided to use, at OU4, the Integrated Exposure Uptake Biokinetic (IEUBK) lead model as a
risk assessment tool to evaluate potential health risk to young children from exposure to lead in the various
media (e.g., indoor dust, tap water, and air) and especially in soil. Based on the IEUBK modeling, 5 out of
47 residences sampled had lead concentrations in yard soil that posed risk to young children that exceeded
acceptable levels. EPA attempts to reduce exposure to lead such that a typical child (or a hypothetical
child) or group of similarly exposed children have a risk of no more than 5 % of exceeding a blood lead
level of 10 micrograms per deciliter (|ig/dL).
Risk to Site Residents Who Live by Eating OU4 Plants and Animals
On OU4, EPA found that lifestyles that involve ingestion of plants grown near source areas or ingestion of
meat or dairy products from animals feeding near source areas, will increase exposure to chemicals of
concern in soils, and will also increase human health risk. These subsistence activities may pose a health
risk even in locations where there are concentrations of contaminants that would generally be seen as
posing minimal risk to the general public.
Risk to Residents Who Consume Water Drawn From Contaminated Ground Water
At OU4, two out of thirteen private wells sampled had lead concentrations that exceed the standards
established in the National Primary Drinking Water Regulations. Since the shallow aquifer is contaminated,
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EPA proposes to protect residents using private wells for drinking water by providing alternative water
supplies if concentrations of lead in well water exceed the National Primary Drinking Water Standard of
0.015 mg/L for lead.
Risk to Residents Who Have Recreational Contact with Source Material
At OU4, areas contaminated with source material are subject to frequent recreational use by adolescents.
To determine the risk to these adolescents, EPA considered using various methods, but decided that using
the Adult Lead Methodology (ALM) was the most appropriate method. Using the ALM, the Baseline
Human Health Risk Assessment predicts that 22.3% of adolescents who play in source areas about 184
days per year (the average number of days without rain and above freezing) will have blood lead levels that
exceed 10 (ig/dL. The female adolescent population may be considered sensitive since exposures during
adolescent years may result in a body burden of lead that is available to transfer to the fetus later in life.
Protecting the sensitive subpopulation will also be protective for adolescent/adult males.
Addressing Human Health Risk
EPA's remediation goal for lead in source materials
EPA attempts to select a remediation goal for adults that will ensure that a fetus of a woman of childbearing
age will have no greater than a 5% chance of having a blood lead level greater than lO^g/dL. To develop
the Remediation Goal for lead in source material that is protective for an adolescent recreator, the adult
lead model (ALM) was adopted as recommended by the Technical Review Workgroup for metals and
asbestos (TRW). During the Feasibility Study, Preliminary Remediation Goals (PRGs) for adolescent
recreators were evaluated based on various possible exposure assumptions (model parameters) presented in
chapter 8 of the Baseline Human Health Risk Assessment (BHHRA). The estimated PRGs ranged between
350 milligrams of lead per kilogram of soil (mg/kg) and 1,095 mg/kg., with more typical PRGs ranging
between 547 mg/kg and 620 mg/kg. However, due to the fact that some chat piles are close to rural
residential areas, there is a potential for younger children to play on them and to become exposed to lead
through incidental ingestion of contaminated source material. In addition, adolescents playing on the chat
will likely come in contact with unvegetated fine tailings at a higher rate than they would on sod-covered
contaminated soil (the model is based on soil), and, therefore, the adolescents playing on the chat piles are
expected to have a lead ingestion rate that ranges toward the higher end of the ingestion rates contemplated
in the adult lead model. Due to these reasons, a more conservative remediation goal of 500 mg/kg (the
same cleanup level used for the residential areas is OU2) was selected as the Remediation Goal for lead in
source material under this ROD. The ALM predicts that this 500-ppm remediation goal for lead in source
materials will protect adolescents who use these areas for recreation, because it provides protection to the
more sensitive future fetuses of female adolescents who use these areas for recreation. Specifically, the
goal is to reduce the central estimate of blood lead concentration in adults that are exposed to source
materials, to a level that ensures that the predicted 95th percentile fetal blood lead concentration of their
offspring does not exceed lO^g/dL. As explained further in the 1997 EPA ROD for OU2 Tar Creek
Residential Areas, the 500 ppm will also be protective for younger children in the event they come in direct
contact with source material.
Increased exposures are also associated with subsistence lifestyles that increase contact with impacted soil
and that increase ingestion of biota (plants or animals) that may have accumulated lead or chemicals of
concern. The Quapaw Tribe has identified subsistence activities that its members undertake on the Site,
and these activities are of the sort that increases ingestion of contaminated biota. The selected remedy
identified in this ROD should provide protection for the subsistence lifestyle at the conclusion of the
remedy. The removal of source materials, transition zone soils, and soils which underlie source material
above the action levels and the implementation of soil rebuilding and grading will result in levels of COCs
well below the action level and may even achieve background concentrations in some settings.
The potential hazards for residents are dependent on their proximity to chat piles, chat bases, tailings ponds,
or smelter waste where elevated concentrations of lead and chemicals of concern have been identified, and
upon their activities in these areas. The more likely it is that a resident will encounter contaminated
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materials; the more likely it is that the resident may face a health risk. Generally, those living closer to the
source materials, especially adolescents, will face a greater risk because they are more likely to use areas
contaminated with source material for recreation or as sources of gravel or sand for construction. At
residential properties that were not remediated thus far, the public may be exposed directly through
contacting contaminated soil. In the proposed plan, EPA addressed the human health risk through removal
of chat over 20 years. In this ROD, EPA addresses human health risk through relocation which allows 30
years for chat removal in a way that is cost effective.
Ecological Risk
The ecological risk assessment identified the potential for unacceptable risk to terrestrial receptors on the
Site. The primary risk drivers (cadmium, lead, and zinc) were found in chat, fine tailings, and soil on-site
in concentrations that are several orders of magnitude above their respective Remediation Goals.
15.0 REMEDIAL ACTION OBJECTIVES
Remedial action objectives (RAOs) consist of medium-specific or location-specific goals for protecting
human health and the environment. This section presents the RAOs and the remediation goals for source
material, soil, and ground water at the Site. It outlines the risks identified in Section 14 and provides the
basis for evaluating the cleanup options presented in Section 16. The RAOs also serve to facilitate the five-
year review determination of protectiveness of human health and the environment.
15.1 Remedial Action Objectives for the Site
Medium
Summary of Remedial Action Objectives
Remediation Goals
Source Material,
transition zone soil,
and soil which
underlies source
material
Prevent adolescents from coming in direct contact, through the
ingestion and inhalation exposure pathways, with lead-
contaminated source material where lead concentrations exceed
500 ppm. The purpose of this objective is to reduce the central
estimate of blood lead concentration in adults (i.e., the mature
adolescents in question) that have been exposed to source
materials to a level that ensures that the 95th percentile fetal
blood lead concentration in their offspring does not exceed 10
Hg/dl. This objective will also be protective for children who
live on-site in the event they come in direct contact with the
source material through the ingestion and inhalation exposure
pathways.
Prevent terrestrial fauna from coming in direct or indirect
contact, through the ingestion exposure pathway, with
cadmium-, lead-, or zinc-contaminated source materials and
soils where cadmium, lead, and zinc concentrations exceed their
respective remediation goals of 10.0 mg/kg, 500 mg/kg, and
1100 mg/kg. By indirect contact EPA means contact with these
contaminants via ingestion of plants grown in contaminated
source materials and soil.
General Tactics:
To meet the above remedial action objectives for source
material, the remedy selected in this ROD calls for excavation of
source materials to native soils with confirmation samples to
ensure the remediation goals are met. The selected remedy
Adolescents:
500 ppm lead in source
material in transition zone
soil, and in the soil which
underlies source material.
Terrestrial Fauna:
10.0 mg/kg cadmium, 500
mg/kg lead and 1100 mg/kg
zinc in source material,
smelter waste, in transition
zone soil, and in the soil
which underlies source
material.
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Medium
Summary of Remedial Action Objectives
Remediation Goals
calls for a minimal footprint of source material and maximum
unrestricted use of Site land.
Source Material,
transition zone soil,
and soil which
underlies source
material
Prevent riparian biota including waterfowl from coming into
contact, through the ingestion exposure pathway, with
unacceptable concentrations of lead, cadmium, and zinc in
surface water and sediment by eliminating all discharge of
cadmium, lead, and zinc from source materials to surface water.
Zero discharge of cadmium,
lead, zinc from source
materials to surface water.
[By zero discharge EPA
means discharge
concentration levels that
would be consistent with the
concentration levels that
would be expected from soil
that has background
concentrations of these
chemicals.]
Soils
Prevent children from direct contact, through the ingestion and
inhalation exposure, with lead-contaminated soil where soil lead
concentrations exceed 500 ppm. [The purpose of this objective
is to limit exposure to soil lead levels such that a typical (a
hypothetical) child or group of similarly exposed children living
on site would have an estimated risk of no more than 5%
exceeding 10 ng/dL blood lead level.]
General Tactics:
To meet the above remedial action objective, the remedy
selected in this ROD calls for excavation of residential yard soil
up to a maximum depth of 12 inches or until soil concentrations
no longer equal or exceed 500 ppm, whichever calls for less soil
to be excavated.
Children:
500 ppm lead in soil
(See OU2 Record of
Decision for Tar Creek
Residential Areas)
Prevent terrestrial fauna from coming in direct or indirect
contact, through the ingestion exposure pathway, with cadmium-
, lead-, or zinc-contaminated soil where cadmium, lead, and zinc
concentrations exceed their respective remediation goals of 10.0
mg/kg, 500 mg/kg, and 1100 mg/kg. By indirect contact EPA
means contact with these contaminants via ingestion of plants
grown in contaminated soil.
Terrestrial fauna:
10.0 mg/kg cadmium, 500
mg/kg lead and 1100 mg/kg
zinc, in transition zone soil,
and in soil underlying
source material.
General Tactics:
To meet the above remedial action objective, the remedy
selected in this ROD calls for excavation of visible source
materials down to native soils with confirmation samples of the
soil taken to ensure that remediation goals are met.
Ground water
Prevent Site residents from the ingestion of water from private
wells that contains lead in concentrations exceeding the National
Primary Drinking Water Standards.
General Tactics:
To meet the above remedial action objective, the remedy will
include an alternative water source for those residences affected.
0.015 mg/L lead at the water
tap
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15.2 Basis and Rationale for Remedial Action Objectives
The basis for the RAOs for the contaminated Site media is the anticipated long-range future land use for the
portions of the Site that includes agricultural and rural residential uses. The implementation of both the
State's voluntary buyout and the buyout included in this Record of Decision will reduce the potential for
exposure to adolescent recreators; however, the exposure will not be completely controlled. The buyout is
voluntary and some residents will likely remain either within the city boundaries or in rural residential
settings.
Native American peoples within the Site may be subjected to unacceptable risks through exposure routes
that are unique to the Tar Creek Site. Some Native Americans, particularly members of the Quapaw Tribe,
still engage in traditional ceremonial, medicinal, subsistence, and artistic practices. Some of these practices
may involve foraging for native herbs, foodstuffs, and fibers that grow on source materials, such as chat
bases, on affected soils or in Site surface waters. There is concern that, by practicing their traditional
lifestyles within the Site, Native Americans may ingest COCs in quantities that result in unacceptable risks.
The selected remedy identified in this ROD should provide protection for the subsistence lifestyle at the
conclusion of the remedy. The removal of source materials, transition zone soils, and soils which underlie
source material above the action levels and the implementation of soil rebuilding and grading will result in
levels of COCs well below the action level and may even achieve background concentrations in some
settings.
Ecological exposures are not expected to decrease. In fact, ecological exposures may possibly increase due
to habitat expansion. Specifically, habitat may expand because of the decreasing human population on the
Site, a result of the voluntary relocation. Aquatic biota may be exposed to COCs above risk-based criteria
in perennial streams, riparian corridors, and ponds. COCs are generally transported to surface water via two
pathways—runoff and seepage from surficial source material deposits and ground water discharge from
mined/mineralized portions of the shallow aquifer. COCs are contributed via these pathways under all flow
conditions, but the largest loads are contributed during seasonal wet periods and rainfall events. EPA's
ROD for OU1 addressed the COC loads to surface water that are contributed by ground water discharges.
Aquatic biota may be exposed to COCs above risk-based criteria due to out-washed source materials that
are mobilized during rainfall events and deposited in Site surface water bodies. These out-washed source
materials can also inundate streambeds and wetland areas, thereby physically affecting otherwise suitable
aquatic habitats.
16.0 DESCRIPTION OF ALTERNATIVES
The final alternatives evaluated in the Feasibility Study relied on a thematic approach to remedial actions to
address the large scale of the task of remediating source materials and affected soils within the Tar Creek
Site. A thematic approach is based on the concept that all of the source material can not be addressed
through one technology or action, but instead different categories or "themes" of source material are
defined (e.g. chat piles, chat bases) that may be addressed with different types of actions or technologies.
In turn, each of these categories or themes may have multiple technologies that can be used to address the
source material.. The themes present at the Site, including the following:
• Chat piles
• Chat bases
• Fine tailings, including both chat-washing fine tailings and floatation tailings
• Smelter wastes
Transition-zone soils
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• Residential yard soils
• Smelter-affected soils
Ten alternatives were evaluated and are described in the Feasibility Study (dated July 2007). After the
Feasibility Study screening process, Alternatives 1, 4, 5, and 8 were retained for further consideration and
detailed analysis.
Voluntary Relocation
In addition to technological approaches, EPA considered permanent relocation as a remedial alternative as
part of the FS. CERCLA Section 101(24), 43 U.S.C. § 9601(24), grants explicit authority to conduct
permanent relocations by defining remedial action to include:
"... the costs ofpermanent relocation of residents and businesses and community facilities where
the President determines that, alone or in combination with other measures, such relocation is
more cost-effective than and environmentally preferable to the transportation, storage, treatment,
destruction, or secure disposition off-site of hazardous substances, or may otherwise be necessary
to protect the public health... "
Because permanent relocation is considered a remedial action, it is selected for use at a Superfund site only
when it has been evaluated through the NCP remedy selection process and determined to be the best overall
remedy for the site.
In June 2004, the State of Oklahoma established a local trust to oversee the relocation of families with
children less than seven years of age, from the area surrounding the towns of Picher and Cardin. Fifty-one
families were relocated under this program. The mission of this trust was expanded under Oklahoma law
(27A O.S. Supp. 2006, sections 2201 et seq.) in 2006 with the commitment by Congress of additional
federal funds ($18.9 million according to ODEQ). The trust is now in the process of conducting a voluntary
relocation of the highest priority residents and businesses in Picher, Cardin, and Hockerville. The 2004
State funds and the 2006 federal funds were not sufficient to provide relocation for all residences and
business in the area that was identified by the trust as eligible for relocation (Figure 9).
In developing the proposed plan for OU4 at the Tar Creek Superfund Site, the EPA considered relocation
of residents living in Picher, Cardin, and Hockerville. EPA considered relocation because, in order to
maintain protectiveness, the remedial alternatives evaluated in the proposed plan would generally require
certain property restrictions that some members of the communities may consider undesirable. These
property restrictions may include the barricading of streets for months at time, disconnecting residential
utilities for extensive periods, and the use of earthmoving equipment and heavy trucks in residential areas.
Additionally, the residents may be impacted by dust from the moving of chat. Permanent relocation might
address the inconvenience associated with these activities; however, under the Uniform Relocation Act
(URA) and its implementing regulations, permanent relocation would have required considerable time and
expense. As part of its OU4 Proposed Plan (July 24, 2007), EPA considered relocation as a possible
alternative. Alternative 5 was EPA's relocation alternative under the Proposed Plan, and it was rejected
because it was not found to be cost-effective.
On November 8, 2007, the Water Resources Development Act of 2007 (WRDA Public Law 110-114)
became law. Section 3135 of WRDA is specific to Ottawa County, Oklahoma and states:
(e) Consideration of Remedial Action- The Administrator of the Environmental Protection Agency
shall consider, without delay, a remedial action under the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (42 U.S.C. 9601 et seq.) for the Tar Creek, Oklahoma,
National Priorities List site that includes permanent relocation of residents consistent with the
program currently being administered by the State of Oklahoma. Such relocation shall not be subject
to the Uniform Relocation Assistance and Real Property Acquisition Policies Act of 1970 (42 U.S.C.
4601 et seq.).
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(f) Estimating Costs- In estimating and comparing the cost of a remedial alternative for the Tar
Creek Oklahoma, National Priorities List site that includes the permanent relocation of residents, the
Administrator shall not include the cost of compliance with the Uniform Relocation Assistance and
Real Property Acquisition Policies Act of 1970 (42 U.S.C. 4601 et seq.).
WRDA eliminates the constraints of the Uniform Relocation Act, enabling EPA to undertake or fund
relocation much more efficiently. As it prepared this ROD, EPA reconsidered relocation in light of this
development, based on the most recent information available from the LICRA Trust. As explained below
in Section 20.3, EPA has now determined that relocation is cost-effective and provides the best balance of
trade offs among the remedial alternatives considered.
16.1 Description of Remedy Components
Remedial Alternatives 1, 4, and 8 are described below to show other alternatives that were considered as
EPA developed the remedy selected in this ROD. The selected remedy is described below as Alternative 5.
16.1.1 Alternative 1 - No Action
Evaluation of "no action" is generally required by the NCP. This alternative prescribed no new remedial
actions; however, it did recognize the engineering actions ongoing for OU1 and OU2, pilot demonstrations
and treatability studies, actions taken under the Oklahoma Plan for Tar Creek, and private chat use.
Capital Cost: $0
Annual O&M Cost: $0
Present Worth: $0
16.1.2 Alternative 4 - Phased Consolidation, Chat Sales and On-site Disposal
If EPA had selected Alternative 4, it would have been identical to Alternative 5—EPA's selected remedial
alternative (described below), except that Alternative 4 would not have included two elements of
Alternative 5. These two elements, that were not included in Alternative 4, are as follows: 1) Under
Alternative 5, EPA will offer to relocate the residents of Picher, Cardin, and Hockerville on a voluntary
basis, and 2) Under Alternative 5, EPA will extend the remedy implementation timeframe from 20 years to
30 years because with relocation there would be less risk of exposure to a new generation of residents.
Alternative 4 Summary
Chat and chat base material excavated, hauled to an on-site chat processor, and
released to that chat processor - Phase 1 + Phase 2
Cover Fine Tailings in Place (with Institutional Controls)
Chat and chat base material excavated and hauled to an on-site repository
Chat and chat base material excavated and injected into mine workings
Excavate and Haul Smelter Wastes to on-site repository
Rural Residential Yard Soils, and
Affected Domestic Well Water
Integrate Near-stream Source Materials and Control Seepage/Runoff
Excavation and Removal of In-Stream Source Material
Volume of Chat Used for Environmentally Acceptable Uses
For a more detailed description of the alternative, please see the Feasibility Study
Quantity
6,159,000 yd3
7.035.000 yd3
13,194,000 yd3
252 acres
938,000 yd3
469,000 yd3
1846 yd3
4 yards
2 households
1,254,000 yd3
18,000 yd3
29,231,000 yd3
Capital Cost: $290,377,000
Annual O&M Cost: $375,000/year decreasing to $125,000/year
Present Worth: $167,735,000
Estimated Implementation time: 20 years
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Volume of source material remaining on-site subject to Institutional Controls: 6,3 14.846iy/j that cover
322 acres
16.1.3 Alternative 5 - Voluntary Relocation, Phased Consolidation, Chat Sales and On-site
Disposal
Alternative 5 is EPA's selected remedy under this ROD.
Relocation
Under Alternative 5—the selected remedy, EPA will provide funding to LICRAT to enable LICRAT to
relocate those residents of Picher, Cardin, and Hockerville that remain after LICRAT has exhausted other
sources of funding. Relocation will be voluntary because EPA understands that some residents may wish
to remain in their homes for a period of time. These residents will be advised of the circumstances EPA
anticipates after the first 3 years of the relocation. EPA expects that municipal services such as water and
sewer service will not be available.
Relocation will mean fewer residents in the Site area, and, consequently, reduced risk of residents being
exposed to chat. Therefore, chat piles can remain in place longer (30 years, compared to 20 under
Alternative 4), allowing commercial chat sales to occur over a longer period with a greatly reduced risk of
exposing residents to any lead contamination from chat. Continued chat sales will contribute to a more cost
effective remedy because it will mean that there will be less chat remaining on-site that must be addressed
with more expensive remedial alternatives (i.e., remedial alternatives that are more costly than chat sales).
Moreover, continued chat sales will mean that less chat will be disposed of on-site. Under Alternative 5—
the selected remedy, the methods described below will be used for chat sales and chat disposal.
Chat Sales
EPA is selecting the chat sales program as outlined below as a part of the CERCLA remedy at this site.
Consequently, activities undertaken in support of chat sales are undertaken pursuant to CERCLA authority
and are part of the CERCLA response action. Chat sales will contribute to a more cost effective CERCLA
remedy because it will mean that there will be less chat remaining on-site that must be addressed with more
expensive remedial alternatives (i.e., remedial alternatives that are more costly than chat sales). Moreover,
continued chat sales will mean that less chat will be disposed of on-site. While EPA does not own any chat
and will not purchase any chat, it will provide guidance to chat sales participants as part of EPA's
CERCLA remedy.
Under Alternative 5—the selected remedy, the methods described below will be used to ensure that
chat/land owners have an opportunity to sell or otherwise plan for the disposal of their chat.
PHASE 1
Source materials will be addressed in a manner that will reduce the overall footprint of contamination and
reduce the need for land use restrictions, institutional controls, and operation and maintenance. Phase 1
includes voluntary relocation and chat sales.
Chat and chat bases from distal areas (generally located outside the high density mining areas and
including rural areas as shown in Figure 3), including associated historic chat covered haul roads
and railroad grades that are not operating, will be excavated to the underlying native soil.
Confirmation samples will be taken following source removal to ensure that the remediation goal
is met. The excavated source material from the distal areas will be transported and released to an
on-site chat processor or future processing location in a previously contaminated area of the Site,
injected into mine workings, or it will be disposed in an on-site repository. Following the removal
of the source materials in the distal areas, the soils will be rebuilt naturally to sustain vegetation
using standard land preparation practices such as ripping, contouring, adding amendments,
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disking, fertilizing, planting and seeding. Excavated areas will not be backfilled with a soil cover.
In recognition of the potential value of chat, chat/land owners in distal areas will be contacted
before any chat is removed from their property. Where these owners agree, chat will be
excavated, transported and released to an on-site chat processor or future processing location in a
previously contaminated area of the Site, injected into mine workings, or it will be disposed in an
on-site repository. Where chat/land owners will not release the chat for excavation and
disposition, they will be required to provide a plan, including a schedule, for the final disposition
of the chat consistent with this ROD. EPA will work with Chat owners to identify alternative
chat disposition options.
o The volume of chat in chat bases and in small chat piles in distal areas is estimated at
3,021,000 yd3.
o For cost estimation purposes, it was assumed that all of the chat that is excavated and
removed from the distal areas will be hauled to an on-site chat processor and released to
that chat processor.
The EPA acknowledges that chat sales are a pre-existing activity at the Site. To ensure that chat
sales continue at the Site and to further promote the environmentally protective use of chat, EPA
will facilitate activities to support chat sales (See Section 19.2.2).
Transition zone soils (soils around and underneath source materials) that exceed the remediation
goals will be excavated to a depth no greater than 12" below the final grade established in the
remedial design. The final grade will consider land uses and site-wide hydrological impacts.
Removed soil may be used for interim cover at the on-site repository. In areas that are excavated,
nearby transition zone soils that do not contain concentrations of chemicals that exceed that
exceed the remediation goals will be used in the natural soil rebuilding process that is
implemented after excavation. The natural soil rebuilding process used to establish the final grade
will include standard land practices such as ripping, contouring, adding amendments, disking,
fertilizing, planting and seeding.
Smelter wastes will be excavated and disposed in an on-site repository. Smelter affected soils will
be managed in the same manner as transition zone soils.
Fine tailings will be injected into mine workings or covered in place. The covered fine tailings
may be consolidated to reduce the footprint of the final cover. Covering in place will be used for
areas that injection is technically impracticable (e.g., adequate mine workings are not in close
proximity or physical characteristics of the tailings are not amenable to injection) or when the
volume of tailings greatly exceeds the surface area (i.e., very deep ponds). Based on existing site
characterization data, and for cost evaluation purposes, EPA has estimated that Central Mill and
Central Mill north tailings ponds will be capped in-place (see Figure 11).
Injection will be implemented in a manner that complies with the underground injection control
regulations for a mine backfill well. As part of the process of ensuring such compliance, a site-
wide hydrogeologic study will be performed prior to implementation of the injection of fines or
chat into the mine workings. The study will address the requirements of the regulations and will
examine whether there is hydraulic connectivity between the Picher Field and the Commerce mine
working, identify strategic subsurface locations for injection in order to maximize the number of
potential injection sites needed to adequately alter the hydrogeology, and evaluate the long-term
effectiveness of this method.
Source material in Tar, Lytle, Elm, or Beaver Creek, or other Site waterways will be addressed on
a priority basis through excavation and/or the installation of a flexible membrane liner, as needed
as determined by EPA. The purpose of these measures is to eliminate the contaminant loading
from in-stream source materials to surface and ground water. As an interim measure, sheet piling,
berms, constructed wetlands, or other engineering controls will be installed to control near-stream
source materials in order to help prevent contamination from migrating to surface water.
Excavated in-stream materials will be returned to their near-stream origin (e.g., chat would be
returned to the near-stream chat pile from which it came). Streambeds addressed by excavation of
in-stream source materials will have erosion control measures installed (e.g., constructed wetlands,
gabion basket wire and rock embankments, or boulders). Where chat/land owners will not release
the chat for excavation and disposition, they will be asked to provide a plan, including a schedule,
for the final disposition of the chat consistent with this ROD.
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To help eliminate exposure, education and community awareness activities will be conducted
throughout the duration of the remedy.
An alternative water supply will be provided where mining-related contaminants in water drawn
from rural residential wells exceed .015 mg/L for lead for rural households. Rural households that
are within the area that has been designated for relocation under the State of Oklahoma's
relocation program, but which do not elect to participate in the relocation program, would be
eligible for an alternative water supply (estimated two residences).
Rural residential yards, not eligible for the LICRAT relocation program, that are found to have
concentrations of soil lead that exceed 500 ppm, will be excavated to a maximum depth of 12
inches, and the area will be backfilled with clean soil, contoured to promote drainage, and
revegetated. If contamination remains at excavation depth, before backfilling, an orange warning
material would be placed at the bottom of the excavation to alert those conducting future
earthmoving activity.
On-site repositories will be constructed to accept Site source materials for final disposal. The
repositories will cover an estimated 28 acres and will be capable of receiving an estimated
1,000,000 yds3 of source materials, affected soils, and other Site-related materials such as wood,
concrete, and miscellaneous debris. The repository design shall incorporate components that
include a clay liner, a filter sand bed, a soil cover, and final site grading. Selection of the
repository location will consider proximity to existing source material locations, thickness of
underlying soil deposits, soil type, depth to ground water, and presence or proximity of floodplains
or other surface water features. On-site repositories will be closed when they reach capacity or at
completion of the remedial action. Closure will be accomplished by covering the repository with
a soil cover, contouring to promote drainage, and revegetating.
Environmental monitoring will be conducted to test for contamination in ambient and near source
air, surface water, ground water, and sediment as needed as determined by EPA during
remediation activities.
Realizing it is a time consuming process to work with distal area chat/land owners, Phase 1 is intended
to be implemented in the following planned timeframes:
Years 1 through 3: Negotiate with distal area land/chat owners for chat release and assist them in
developing their disposition plan, begin remedial design, and complete relocation by LICRAT.
Years 3 through 12: Construct on-site repository, remove smelter waste, remove source material from
streams, integrate near stream source material, provide alternative water supply, and remediate rural
residential yards.
Years 3 through 17: Address fine tailings and consolidate distal area chat.
Years 1 through 25: Chat sales will be maximized through federal, state, tribal, and private activities.
PHASE 2
Phase 2 addresses source materials that remain after Phase 1 cleanup activities. This may include chat
bases, tailings ponds, unmarketable chat piles and bases, and remaining chat from distal area consolidation.
After completion of Phase 1 activities, distal area chat will be consolidated to areas located in the core of
the Site (heavily mined area) that are already contaminated and the surface area of the Site contaminated by
source material will be reduced by approximately 75%. Consolidation of distal area chat to the core area
will also improve the marketability of the chat. Phase 2 activities will be implemented during the last 5
years of the remedy, years 26 through 30, to make the remedy more cost efficient.
The remedy will be reviewed, at a minimum, every five years since hazardous substances remain
on-site with concentrations that exceed concentration levels that allow for unrestricted use and
unrestricted exposure. The remedy would be reviewed to ensure protection of human health and
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the environment. As part of the five-year review, EPA will evaluate the progress of chat sales.
Chat piles and bases remaining after 10 years will be evaluated for commercial viability. This
determination will be made using input from the chat/land owners, appropriate Tribal
representatives, and the commercial operators.
Unmarketable chat piles and bases will be excavated, transported and released to an on-site chat
processor or future processing location in a previously contaminated area of the Site, injected into
mine workings, or disposed in an on-site repository. Where chat/land owners will not release the
unmarketable chat, they will be asked to provide a plan, including a schedule, for its final
disposition consistent with this ROD. If EPA finds that the plan or schedule is unacceptable, EPA
may take legal action. Scheduled disposition under the owners' plans must be completed within
five years. The volume of unmarketable chat piles and bases is estimated at 9,380,000 yd3.
Historic haul roads and non-operating railroad grades that are contaminated will be managed the
same as chat bases.
Institutional controls and operation and maintenance activities will be implemented, as needed as
determined by EPA, at repositories and at covered fine tailings ponds where the fine tailings were
capped in place.
Environmental monitoring will be conducted, as needed as determined by EPA, to test for
contamination in ambient and near source air, surface water, ground water, and sediment during
remediation activities.
The following summary describes the methods that would be used to address OU4 contamination under
Alternative 5. The chart also provides the approximate volume of material to be addressed by each method,
respectively. The remaining volume of source material which appears in italics below the chart is primarily
material capped and left in place that will require Institutional Controls.
Voluntary Relocation
Alternative 5 Summary
Chat and chat base material excavated, hauled and released to a chat
processor - Phase 1 + Phase 2
Cover Fine Tailings in Place
Chat and chat base material excavated and injected into mine workings
Chat and chat base material excavated and hauled to an on-site repository
Excavate and Haul Smelter Wastes to on-site repository,
Rural Residential Yard Soils, and
Affected Domestic Well Water
Integrate Near-stream Source Materials and Control Seepage/Runoff
Excavation and Removal of In-Stream Source Material
Volume of Chat Used for Environmentally Acceptable Uses
Quantity
569 properties
6,159,000 yd3
7.035.000 yd3
13,194,000 yd3
252 acres
469,000 yd3
207,000 yd3
1846 yd3
4 yards
2 households
1,254,000 yd3
18,000 yd3
36, 538,000 yd3
Capital Cost: $332,435,000
O&M Cost: S3 75,000/year decreasing to $125,000/year.
Present Worth: $167,288,000
Estimated Implementation time: 2 years to complete the Voluntary Relocation once it is
fully funded, and 30 years to implement the remaining components.
Volume of source material remaining on-site subject to Institutional Controls: 6,314,846yd3 that covers
322 acres
16.1.4 Alternative 8 - Chat Sales and Total Source Consolidation
Alternative 8 would have included many of the same elements as Alternative 5 (including chat sales but not
relocation); however, urban and near-stream chat piles and bases would be removed and integrated into
existing on-site upland chat deposits as an early response instead of installing engineering controls for near-
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stream source materials as required under Alternative 5. Under this alternative, all the chat and chat bases
would have been excavated down to native soil and the excavated areas would have been reclaimed by
deep tilling, amending the soils if necessary to re-establish vegetation, and re-vegetating with Site-adapted
plant species.
Alternative 8 would have utilized various elements to include the following:
All chat sources (piles, bases, etc.) located in urban and near-stream settings would have been
excavated, transported to existing upland chat deposits, and consolidated for future processing and
removal by commercial processors. Where possible, chat would have been transported and
consolidated in existing upland deposits where active chat processing facilities are already in
place. Chat processors would have been selected during Remedial Design based on
implementability factors and cost factors (e.g., the cost of transportation and the chat processors'
capacity). Alternatively, under Alternative 8, chat processing facilities could have been
established by commercial chat processors (if they so desired and made the necessary
arrangements with chat and property owners) at the new consolidated chat deposits to facilitate
future processing and removal.
After 20 years, all unprocessed chat would have been injected into underground mine workings or
disposed in an on-site repository.
Fine tailings deposits located in urban and near-stream areas would have been excavated and
injected into underground mine workings or covered in place and revegetated. Fine tailings
deposits located in near-stream areas would be excavated and transported to an existing upland
fine tailings deposit that would have been covered in place. For cost estimating purposed,
injection was assumed.
Excavated areas would have been reclaimed similar to actions for chat source materials.
Upland fine tailings impoundments would have been stabilized or repaired and subsequently
covered with a 12-inch soil cover and revegetated to prevent future releases of fine tailings to the
surrounding environments.
Transition zone soils would have been deep tilled to reduce metal concentrations in the upper
layers, amended with biosolids or other organic matter, and revegetated with site appropriate plant
species. Abandoned chat haul road and chat-contaminated non-operating railroad grades would
have been excavated and disposed of in covered upland repositories.
Smelter wastes would have been consolidated on-site and covered with vegetated soil covers. The
covered areas would have been reclaimed with vegetation and protected by institutional controls.
Smelter-affected soils would have been deep tilled to reduce metal concentrations in the upper
layers, amended with biosolids or other organic matter, and revegetated with site appropriate
species.
Rural residential wells with water that exceeds remediation goals and yards where soil lead
concentrations exceed remediation goals would have been addressed in the same manner as they
are addressed under Alternative 5.
Under Alternative 8, the Operable Unit 4 remedy would have been reviewed every five years since
hazardous substances remain on-site that exceed concentration levels that allow for unrestricted use and
unrestricted exposure. The remedy would have been reviewed to ensure protection of human health and the
environment. As part of the review, EPA would have evaluated the progress of chat sales at least every five
years (same as Alternative 5).
The following summary describes the methods that would have been used to address OU4 contamination
under Alternative 8, and the approximate volume of material to be addressed by each method, respectively.
The remaining volume of source material which appears in italics below the chart is primarily material
capped and left in place that will require Institutional Controls.
Alternative 8 Summary
Quantity
12,796,000 yd3
7,300,000 yd3
4,690,000 yd3
Excavate and Consolidate Urban Chat Piles and Urban Chat Bases
Excavate and Consolidate Near-Stream Chat Piles and Chat Bases
Consolidate Upland Chat and Inject into Mine Workings
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Excavate and Consolidate Urban Fine Tailings, Inject into Mine Workings
Excavate and Consolidate Near-Stream Fine Tailings, Inject into Mine Workings
Stabilize and Cover Upland Fine Tailings and Transported Near Stream Tailings
In Place
Consolidate and Cover Smelter Wastes
Deep Till Smelter Affected Soils and Abandoned Haul Roads and RR Grades
Rural Residential Yard Soils, and
Affected Domestic Well Water
Volume of Chat Used for Environmentally Acceptable Uses
344,000 yd3
1,654,000 yd3
8,812,000 yd3
1,846 yd3
14 acres
4 yards
2 households
29,231,000 yd3
Capital Cost: $478,975,000
Annual O&M Cost: $4 75,000/year decreasing to $225,000/year
Present Worth: $255,909,000
Estimated Implementation time: 20 years
Volume of source material that would have remained on-site subject to Institutional Controls:
11,849,846yd3 that cover 846 acres
16.2 Common Elements and Distinguishing Features
This section describes common elements and distinguishing features of the alternatives described above in
Section 16.1 of this ROD.
16.2.1 Chat Use and Sales
All of the remedial alternatives considered by EPA (except the no further action alternative) under the
Proposed Plan, also included provisions for chat sales. These provisions were adopted as part of the
remedy selected in this ROD. For more information regarding these provisions for chat sales, see Section
19.2.2 below.
To ensure that Site chat sales continue and that chat is used in a fashion that is protective of human health
and the environment, under all of the remedial alternatives considered by EPA (except the no further action
alternative) under the Proposed Plan, all Site chat would be managed according to the criteria provided in
the Chat Rule, 40 CFR Part 278, and its preamble. The remedy selected in this ROD includes these Part
278 waste management criteria. This means that EPA is including both the regulations that apply to
transportation construction projects and the preamble guidance that applies to non-transportation, non-
residential projects as requirements under the selected remedy. In addition, only the uses described in the
preamble (including EPA's June 2007 fact sheet; EPA530-F-07-016B) and the transportation construction
project uses described in 40 CFR Part 278 will be allowed for Site chat under this ROD. EPA further
explains how these criteria apply in Section 19.2.2 below.
16.2.2 Certification, Record Keeping and Reporting
The requirements described below in Section 19.2.2 would have applied under all of the remedial
alternatives evaluated.
16.2.3 Watershed-Based Approach
As part of the selected remedy under this ROD, a watershed-based approach will be taken to address the
potential effects remedial actions may have on the local watersheds. A baseline hydrology model will be
developed as part of the remedial design to reflect the existing land uses in the basin and to reflect any
rainfall storage within the source materials. As source materials are removed, the capacity of the soil and
proposed land use to absorb rainfall will be evaluated. The model may also be used as a planning and
design tool to prepare a comprehensive watershed plan to mitigate any potential runoff increases.
Complete details of this approach and possible control and mitigation measures will be formulated during
the remedial design.
EPA will encourage local, state, and federal authorities to enforce Best Management Practices and Storm
Water Pollution Prevention Plans for facilities on the Site to ensure environmentally protective chat sales.
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16.2.4 Five-Year Reviews
Five-Year Reviews will be required under the selected remedy. Reviews will be required because the area
requiring cleanup will not be available for unrestricted reuse. Since no cleanup would be completed under
the "no action "alternative, all waste would be left in place and unrestricted reuse would be prohibited. As
part of the review, EPA will evaluate the progress of chat sales at least every five years. Chat piles and
chat bases that remain and that are unmarketable after 10 years will be identified and evaluated to see if it
can be sold profitably. This determination will be made with input from the chat/landowners, appropriate
Tribal representatives, and the commercial operators.
16.2.5 Institutional Controls
ICs were a component common to all action alternatives discussed by EPA in its Proposed Plan, and ICs
are included in the selected remedy. These controls will be required to aid in the management of the wastes
left on-site and to ensure that only appropriate reuse options are implemented. ICs under the selected
remedy include deed notices placed on land parcels that are contained in the Site. ICs would notify current
and potential future deed holders of the presence of wastes left on-site. In accordance with Oklahoma law
(27A O.S. § 2-7-123), deed notices would identify the reason for the notice, the affected property, the
remedy, engineering controls, and land and ground water use restrictions. A recordable notice including an
easement granting access to the ODEQ for continued remedial response will be filed by the ODEQ. If DOI
is the trustee for the property where wastes are covered and left in place, then ICs will be developed in
coordination with DOI.
16.2.6 Presumptive Remedies
Under the EPA guidance entitled Presumptive Remedy for Metals-in-Soil Sites (EPA, 1999a), the
suggested presumptive remedy, in the appropriate circumstances, for low-level threat metals-in-soil waste
is containment in place [see 9355.0-72FS at pp. 2 and E-4], Based on the circumstances at OU4 (i.e., low-
level threat metals in soil waste) and based on National Contingency Plan (NCP), 40 CFR Part 300, criteria,
however, EPA decided, in the remedy screening phase, that it is not practicable or appropriate to pursue the
presumptive remedy process at this mining site. The primary reasons and circumstances for not pursuing
the suggested presumptive remedy at the Site are the low degree of support for containment in place by the
parties interested in OU4 (i.e., the State of Oklahoma, the Quapaw Tribe, and the local community), the
low effectiveness of containment over such a large area, and the difficulties associated with implementing
such a remedy. These issues are further discussed in the Feasibility Study.
16.3 Expected Outcomes of Each Alternative
The "no action" alternative would not have addressed the risks identified in the BHHRA or in the
Ecological Risk Assessment. It would have allowed source material to remain on approximately 4220
acres, eliminating the potential for this land to achieve beneficial reuse.
As far as addressing source materials including chat is concerned, Alternatives 4 and 5 would achieve
essentially the same outcome; although, it will take Alternative 5 ten years longer to complete source
material remediation. Alternatives 4 and 5 would address source material on approximately 4220 acres in
order to attain remediation goals. It is estimated that, under alternatives 4 and 5, 322 acres would contain
waste in place. Alternative 5 includes institutional controls that will prohibit agricultural and residential
use of these 322 acres. Alternative 4 would have had the same prohibitions. Under Alternative 5, the
remaining 92% of the 4220 acres will meet remediation goals that will allow these acres to be used as
residential areas by the general public. Alternative 4 would have met these same remediation goals in these
areas.
Alternative 8 would also have addressed the 4220 acres of Source Material, achieving the same
performance standards. However, under Alternative 8, institutional controls would have prohibited
agricultural and residential use on 846 acres. This means that under Alternative 8 only 80% of the 4220-
acre source material area would have been acceptable for residential use by the general public once the
remedial action was complete.
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17.0 COMPARATIVE ANALYSIS OF ALTERNATIVES
The EPA uses nine NCP criteria to evaluate remedial alternatives for the cleanup of a release or Site.
These nine criteria are categorized into three groups: threshold, balancing, and modifying. The threshold
criteria must be met in order for an alternative to be eligible for selection. The threshold criteria are overall
protection of human health and the environment and compliance with ARARs. The balancing criteria are
used to weigh major tradeoffs among alternatives. The five balancing criteria are long-term effectiveness
and permanence; reduction of toxicity, mobility or volume through treatment; short-term effectiveness;
implementability; and cost. The modifying criteria are state acceptance and community acceptance.
17.1 Overall Protection of Human Health and the Environment
Under the NCP, remedial alternatives shall be assessed to determine whether they can adequately protect
human health and the environment, in both the short- and long-term, from unacceptable risks posed by
hazardous substances, pollutants, or contaminants present at the site by eliminating, reducing, or controlling
exposures to levels established during development of remediation goals, See 40 CFR § 300.430(e)(2)(i).
Overall protection of human health and the environment draws on the assessments of other evaluation
criteria, especially long-term effectiveness and permanence, short-term effectiveness, and compliance with
ARARs. Overall protection of human health and the environment is a threshold criterion. Each alternative
must meet this threshold criterion in order to be eligible for consideration.
Each of the action alternatives (i.e., Alternative 4, 5 and 8) would meet the first evaluation criterion, overall
protection of human health and the environment, in that they each eliminate, reduce, or control human and
ecological exposures to concentration levels of contaminants which were established as remediation goals.
As stated in the preceding paragraph, however, our assessment of overall protection of human health and
the environment draws on our assessments of the alternatives under other criteria as well. Under two of
these other criteria, Alternative 5 is clearly superior. These other criteria are listed below (enumerated with
romanette) with a brief explanation of our assessments of the action alternatives under each criterion
respectively:
i) long-term effectiveness and permanence: As fully explained below in Section 17.3 of this ROD, there
are uncertainties associated with the use of land disposal for providing long-term protection from residuals.
Also, with land disposal there is the potential that the technical components of the alternative, such as a
cap, will have to be replaced. So the remedial alternatives that call for the least land disposal should have
the greatest long-term effectiveness and permanence (if all other factors are equal). Under Alternatives 4
and 5 there would be the smallest footprint of land disposed source material. Each of the action
alternatives use some land disposal including repositories for some consolidated waste, and they also use
capping of fine tailings deposits. Nonetheless, since they have the smallest footprint of land disposal,
Alternatives 4 and 5 have the greatest long-term effectiveness and permanence over the largest area,
compared to the other remedial alternatives evaluated. Alternatives 4 and 5 call for rapid consolidation of
chat bases and small chat piles from the distal areas. Alternative 8 would have the largest footprint of all
the action alternatives, and, consequently, it would have the least long-term effectiveness and permanence
of all the action alternatives considered.
ii) short-term effectiveness, As fully explained below in Section 17.5 of this ROD, Alternative 5 has the
greatest short-term effectiveness of all the remedial alternatives evaluated. Under Alternative 5, short-term
risks to the community are the least since it is anticipated that the population that is most at risk will be
relocated, probably in less than three years. No other alternative would provide this level of protectiveness
in the short term. .
iii) compliance with ARARs. As explained below in Section 17.2, all of the action alternatives including
Alternative 5, comply with ARARs. Alternative 1, the no action alternative, would not comply with
ARARs.
To summarize, all the action alternatives would meet remediation goals and ARARs, but Alternative 5 has
superior short-term effectiveness since it provides for relocation of those most at risk. Alternatives 4 and 5
have superior long-term effectiveness and permanence because they would leave the smallest footprint of
contained contaminated source materials on-site.
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17.2 Compliance with ARARs
Section 121(d) of CERCLA and the NCP §300.430(f)(l)(ii)(B) require that remedial actions at CERCLA
sites at least attain legally applicable or relevant and appropriate Federal and State requirements, standards,
criteria, and limitations which are collectively referred to as "ARARs," unless such ARARs are waived
under CERCLA § 121(d)(4). ARARs are listed in Table 13. Compliance with ARARs is a threshold
criterion which means that alternatives that do not meet ARARs are not eligible for consideration.
Applicable requirements are those cleanup standards, standards of control, and other substantive
requirements, criteria, or limitations promulgated under Federal environmental or State environmental or
facility siting laws that specifically address a hazardous substance, pollutant, contaminant, remedial action,
location, or other circumstance found at a CERCLA site. Only those State standards that are identified by a
state in a timely manner and that are more stringent than Federal requirements may be applicable. Relevant
and appropriate requirements are those cleanup standards, standards of control, and other substantive
requirements, criteria, or limitations promulgated under Federal environmental or State environmental or
facility siting laws that, while not "applicable" to a hazardous substance, pollutant, contaminant, remedial
action, location, or other circumstance at a CERCLA site address problems or situations sufficiently similar
to those encountered at the CERCLA site that their use is well-suited to the particular site.
All action alternatives evaluated (i.e., Alternatives 4, 5, and 8) would meet ARARs.
Chemical-Specific ARARs.
Chemical-specific ARARs identified for OU4 are consistently met by all the action alternatives. The
chemical-specific ground water ARARs would be met at residents' taps under all the action alternatives,
but are not met in the shallow aquifer in affected areas of the Site. Remediation of the shallow aquifer is not
part of the scope of OU4.
Action-Specific ARARs.
All of the candidate action alternatives are equally capable of meeting the action-specific ARARs identified
for the individual alternatives.
Location-Specific ARARs.
All the candidate action alternatives are equally capable of meeting the location-specific ARARs identified
for the individual alternatives.
To Be Considered (TBC).
Pertinent EPA guidance documents that were considered in establishing remediation goals are identified in
the administrative record file including the bibliographies of documents in the record (e.g., the risk
assessment documents, and the RI and FS reports). All action alternatives meet remediation goals
established with advice from these guidance documents.
17.3 Long-Term Effectiveness and Permanence
Under CERCLA, EPA is required to select remedies that utilize permanent solutions to the maximum
extent practicable. See 42 U.S.C. § 9621(b)(1). In order to compare the remedy alternatives considered for
this ROD, long-term effectiveness and permanence of each alternative was viewed along a continuum (i.e.,
each alternative was viewed as offering a greater or lesser degree of long-term effectiveness and
permanence). Alternatives that are more effective in the long-term are more permanent. See A Guide to
Preparing Superfund Proposed Plans, Records of Decision, and Other Remedy Selection Decision
Documents, OSWER 9200.1-23P (July 1999) at p. 3-9. Under the NCP at 40 CFR 300.439(e), factors that
shall be considered, as appropriate, in determining the long-term effectiveness and permanence of a remedy
include the following romanette-enumerated criteria:
i) Magnitude of residual risk remaining from untreated waste or treatment residuals remaining at
the conclusion of the remedial activities. The characteristics of the residuals should be considered
to the degree that they remain hazardous, taking into account their volume, toxicity, mobility, and
propensity to bioaccumulate.
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The type of mining waste and mill waste that will be addressed under any of the Alternatives at OU4 is a
high volume low-level threat waste and EPA expects to use engineering controls instead of treatment for
this type of waste. See 40 CFR § 300.430(a)(l)(iii)(B). None of the waste will be treated under any of the
remedy alternatives considered. Consequently, this criterion— "Magnitude of residual risk remaining from
untreated waste or treatment residuals remaining at the conclusion of the remedial activities" was not
relevant for remedy selection under this ROD.
ii) Adequacy and reliability of controls such as containment systems and institutional controls that
are necessary to manage treatment residuals and untreated waste. This factor addresses in
particular the uncertainties associated with land disposal for providing long-term protection from
residuals; the assessment of the potential need to replace technical components of the alternative,
such as a cap, a slurry wall, or a treatment system; and the potential exposure pathways and risks
posed should the remedial action need replacement.
Under Alternative 5 and Alternative 4, in Phase I, chat and chat bases from distal areas would be excavated
down to native soils, and confirmation samples will be taken to ensure that the remediation goal is met.
The removed material will be excavated, transported and released to an on-site chat processor or future
processing location in a previously contaminated area of the Site, or it will be disposed in an on-site
repository. Under Alternative 8 chat and chat bases in urban and near-stream areas would be excavated and
moved in an upland deposit for future processing. Under Phase II of both Alternative 5 and Alternative 4,
chat that is disposed of at EPA discretion would be excavated, transported and released to an on-site chat
processor or future processing location in a previously contaminated area of the Site, or it will be disposed
in an on-site repository. The remaining Phase II chat will be addressed in a similar manner as Phase I but
will occur at the later stage of the remedy to maximize active chat sales and to reduce the volume of Source
Material in these areas. In terms of the evaluation criterion above, under Alternative 5 and Alternative 4,
most of OU4 areas would be free of source material deposits (they will be excavated to native soil), and,
consequently, in those areas, there will be no "uncertainties associated with land disposal for providing
long-term protection from residuals." Further, in terms of the above criterion, under Alternatives 4 and 5
there will be no "potential need to replace technical components of the alternative, such as a cap, a slurry
wall, or a treatment system " in most parts of OU4 since these technical components will not be used in
most parts of OU4 (slurry walls and treatment systems will not be used at all), with the major exceptions of
repositories and covered fine tailings. Finally, under each of the alternatives, there will be no "potential
exposure pathways and risks posed" since the remedial action (excavation to native soils) which covers
most OU4 areas will not use technical components that may "need replacement." Alternative 8 has a lower
long term effectiveness and permanence compared to Alternative 5 and Alternative 4 because Alternative 8
calls for more widespread areas and larger volumes of source materials remaining on the land surface
indefinitely, contained by capping. These capped areas, under Alternative 8, face greater "uncertainties
associated with land disposal for providing long-term protection from residuals. " These capped areas
under Alternative 8 also face a greater "potential need to replace technical components of the alternatives,"
specifically, the potential need to replace caps. Finally, there is greater risk that there may be "potential
exposure pathways and risks posed should the remedial action [i.e., the extensive caps] need replacement
under the Alternative 8.
As EPA compared the remedy alternatives considered in developing this ROD, long-term effectiveness and
permanence of each alternative was viewed along a continuum (i.e., each alternative was viewed as
offering a greater or lesser degree of long-term effectiveness and permanence). To illustrate the relative
long-term effectiveness and permanence for some of these alternatives, EPA ranked them below, with the
alternative having the greatest long-term effectiveness and permanence ranked first and the one with the
least long-term effectiveness and permanence ranked last:
RANK
1-Alternative 5 -The Selected Remedy (Voluntary Relocation, Phased Consolidation, and On-
site Disposal) and Alternative 4 (Phased Consolidation, and On-site Disposal) -
Alternatives 4 and 5 call for consolidation of chat bases and small chat piles from the distal
areas. In fact, as explained above, Alternatives 4 and 5 will leave the smallest footprint
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and volume of contained contaminant source material of any alternative. This means that,
of the alternatives evaluated, Alternatives 4 and 5 have the greatest long term effectiveness
and permanence.
2-Alternative 8 (Total Source Consolidation, Stabilization, and Institutional Controls) -This
alternative calls for the most source material to be contained on-site; consequently, fewer
areas are excavated to native soil and a larger footprint of contained contaminated source
material would remain.
3-Alternative 1 - No Action - Under the No Action alternative, source materials remain in
place, and, since EPA has documented ecological and human health risk, the no action
remedy is not an effective or permanent remedy.
17.4 Reduction in Toxicity, Mobility, and Volume
Reduction of toxicity, mobility, or volume through treatment refers to the anticipated performance of the
treatment technologies that may be included as part of a remedy.
Reduction in toxicity, mobility and volume through treatment is not relevant to our cost-effectiveness
analysis for OU4.
The type of mining waste and mill waste that will be addressed at OU4 is a high volume low-level threat
waste and EPA expects to use engineering controls instead of treatment for this type of waste under all the
alternatives evaluated. See 40 CFR § 300.430(a)(l)(iii)(B). Consequently, this criterion- reduction in
toxicity, mobility and volume through treatment, is not relevant to the evaluation of cost effectiveness. No
treatment is involved in any of the evaluated alternatives.
17.5 Short-Term Effectiveness
Under this criterion, the short-term impacts of alternatives shall be assessed considering the following:
(i) Short-term risks that might be posed to the community during implementation of an alternative; (2)
Potential impacts on workers during remedial action and the effectiveness and reliability of protective
measures; (3) Potential environmental impacts of the remedial action and the effectiveness and reliability of
mitigative measures during implementation; and (4) Time until protection is achieved.
Here is our analysis of the short-term effectiveness of Alternative 5:
(a) Short-term risks that might be posed to the community during implementation of an alternative;
Under Alternative 5, short-term risks to the community are the least since it is anticipated that most of the
population that is most at risk will be relocated, probably in less than three years. No other alternative
provides this level of protectiveness in the short term.
(b) Potential impacts on workers during remedial action and the effectiveness and reliability of protective
measures;
All identified short-term risks to workers can be mitigated through legally required worker health and
safety training and protection measures. However, while potential risks to workers during remedial actions
are reasonably similar under all the action alternatives, they are expected to be smaller under Alternative 4,
followed by Alternatives 5 and 8. Alternative 8 potentially poses greater risk to workers since it is
dependent upon more intense and heavy construction methods and approaches. The voluntary relocation
component of Alternative 5 would also pose an additional minor risk to workers engaged in demolition of
purchased structures that is not prescribed in Alternatives 4 and 8.
(c) Potential environmental impacts of the remedial action and the effectiveness and reliability of
mitigative measures during implementation
Potential environmental impacts will be similar for each of the action alternatives and can be controlled
through management approaches and scheduling of activities. One key difference between the remedial
alternatives involves the dependence upon covering of materials in place and the required volume of
borrow soils. The volume and aerial extent of soil removed from borrow source areas to meet the needs of
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the soil cover system is a potential concern in that these soils are often in productive use as agricultural or
pasture lands. Alternatives 4 and 5 have the smallest requirement of cover soils at an estimated 1,189,000
yd3 of cover soil. Alternative 8 has a cover soil requirement estimated at 2,713,000 yd3, a volume and area
requirement that would lead to a greater potential of environmental impacts and an increased management
burden to control the potential impacts.
(d) Time until protection is achieved.
Alternative 8 achieves full implementation of the RAOs within a 20-year timeframe. Alternative 4
achieves control of all source materials within a 20-year timeframe but some of the volume is in a
controlled setting at a commercial chat processing operation (as opposed to being addressed by an
engineering control). This volume, and the area occupied by the volume, is expected to be reduced
significantly within approximately 5 years as commercial processing continues, under Alternative 4.
Alternative 5 is expected to take 30 years to meet the RAOs The additional time associated with
Alternative 5 is associated with the effects of the voluntary relocation and the phased approach of the work.
The voluntary relocation component of Alternative 5 is estimated to require less than three years to
complete when it is fully funded.
Under Alternative 5 virtually all contaminant source material will be removed from vast distal areas of
OU4, as those areas are cleaned up to native soil. This will be accomplished within 15 years. In addition,
under Alternative 5, the population that is most at risk will be relocated. No other remedial alternative can
compare to Alternative 5 in short term effectiveness.
17.6 Implementability
Under this criterion, the ease or difficulty of implementing the alternatives shall be assessed by considering
the enumerated factors in italics that appear below. Following each factor is an analysis of the alternatives
that were considered in developing the ROD. Implementability addresses the technical and administrative
feasibility of a remedy from design through construction and operation. Factors such as availability of
services and materials, administrative feasibility, and coordination with other governmental entities are also
considered.
(1) Technical feasibility, includins technical difficulties and unknowns associated with the construction
and operation of a technolosv. the reliability of the technolosv. ease of undertakins additional remedial
actions, and the ability to monitor the effectiveness of the remedy.
All alternatives rely upon proven, conventional, and readily implementable technologies and construction
techniques for addressing the vast majority of source materials and affected soils. The technical feasibility
of injecting source materials into flooded underground mine workings has been demonstrated through pilot
studies that have been conducted by EPA. The studies have concluded that the injection of both chat and
fine tailings is feasible, with the injection of fines being more efficient. Monitoring of the effectiveness of
the remedy will generally entail confirming that remediation goals have been met in soils and Source
Materials using standard analytical methods. Ambient air will also be monitored during remediation to
ensure that remedial activities do not cause unacceptable releases of particulates.
(2) Administrative feasibility, includins activities needed to coordinate with other offices and asencies
and the ability and time required to obtain any necessary approvals and permits from other asencies (for
off-site actions);.
In the Proposed Plan, EPA said that Alternative 4 would be the most administratively feasible because it
requires excavation in a relatively small area (compared to Alternative 8). In the Proposed Plan, EPA said
that Alternative 5 would be the least administratively feasible to implement due to the administrative
requirements of relocation under the URA; however, with the passage of WRD A coupled with the
arrangements that EPA has made with LICRAT, EPA has reevaluated Alternative 5 and determined that it
is almost equal to Alternative 4 in implementability. Specifically, WRDA provides that the URA does not
apply to EPA's relocation efforts at Tar Creek under Alternative 5, and LICRAT has agreed to undertake
EPA relocation with EPA's role generally limited to conducting some oversight. Consequently, while EPA
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still views Alternative 4 as the most administratively feasible alternative to implement, EPA views
Alternative 5 as almost administratively feasible as Alternative 4. Alternative 8 would have been the most
difficult to implement administratively because under Alternative 8 access to vast areas would have had to
have been acquired very quickly. In addition, under Alternative 8 there would have been mass removal of
material from urban and near-stream settings in a relatively short period. This effort, under Alternative 8
would have required significant cooperation with municipalities, the county, the BIA, land owners, chat
owners, and chat processors.
(3) Availability of services and materials, includins the availability of adequate off-site treatment,
storase capacity, and disposal capacity and services; the availability of necessary equipment and
specialists, and provisions to ensure any necessary additional resources: the availability of services and
materials: and availability of prospective technolosies..
In its Proposed Plan, EPA said that Alternative 5 had an increased labor requirement associated with both
the administration and implementation of the voluntary relocation component of this remedy; accordingly,
EPA said that Alternative 5 was less implementable than Alternative 4 under this criterion. However, with
the passage of WRDA coupled with the fact that LICRAT will generally administer the relocation with
some EPA oversight, EPA believes that Alternative 5 will be almost as implementable under this
subcriterion as Alternative 4. Alternative 5 will certainly be less difficult to implement than Alternative 8
because Alternative 8 would have required extensive resources to undertake the large-scale relocation of
source material that it calls for. EPA now believes that the required labor and materials are readily
available to implement all the alternatives, but Alternatives 4 and 5 are expected to be the least likely of the
alternatives to be affected by availability of materials or labor. With respect to the availability of borrow
soils to construct the cover systems, Alternative 4 and 5 each have identical requirements that are less than
that of Alternative 8. Alternative 5 has an increased labor requirement associated with the demolition and
disposal of the residential and commercial properties purchased through the voluntary relocation. While
this labor force is expected to be available, it is an increased requirement of Alternative 5.
17.7 Cost
The types of costs that shall be assessed under this criterion include the following:
(1) Capital costs, including both direct and indirect costs;
(2) Annual operation and maintenance costs; and
(3) Net present value of capital and O&M costs.
The estimated net present worth costs for the alternatives, not including the No Action Alternative, range
from $167,288,000 for Alternative 5, to $255,909,000 for Alternative 8. Table 10 contains the detailed
breakout of costs for each alternative with respect to the criterion. In the future, if injection of chat and fine
tailings is found to be a viable disposal option, the cost of the remedy may change.
17.8 State And Tribal Acceptance
This criterion considers whether the State agrees with the EPA's analyses and recommendations, as
described in the RI/FS and Proposed Plan. The State of Oklahoma, through ODEQ, provided written
comments on the Proposed Plan in a letter dated September 28, 2007. ODEQ did not concur with the
Preferred Alternative in the Proposed Plan and offered the following major comments:
• Alternative 5 [which includes relocation] is the State's preferred alternative; and
• Implementation of the Off-site Rule could inhibit the sale of chat.
The Quapaw Tribe provided substantial comments in a letter dated October 1, 2007, raising several
concerns with the implementation of chat sales. EPA has provided detailed responses to these comments
and others in the Responsiveness Summary (see ROD Part 3).
17.9 Community Acceptance
The EPA conducted a public meeting on August 28, 2007, to present the Proposed Plan to the public. The
EPA presented Alternative 4 as the Preferred Alternative for the Site. Comments received from the
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affected community overwhelmingly supported the inclusion of voluntary relocation into the remedy for
OU4.
18.0 PRINCIPAL THREAT WASTE
The NCP establishes an expectation that EPA will use treatment to address the principal threats posed by a
site wherever practicable (NCP §300.430(a)(l)(iii)(A)). Identifying principal threat wastes combines
concepts of both hazard and risk. In general, principal threat wastes are those source materials considered
to be highly toxic or highly mobile which generally cannot be contained in a reliable manner or would
present a significant risk to human health or the environment should exposure occur. Conversely, non-
principal threat wastes are those source materials that generally can be reliably contained and that would
present only a low risk in the event of exposure. The manner in which principal threats are addressed
generally will determine whether the statutory preference for treatment as a principal element is satisfied.
High concentrations of lead are addressed under the selected remedy identified in this ROD; however, the
concentrations of lead are not so high as to be several orders of magnitude above levels that allow for
unrestricted use and unlimited exposure. Therefore, the lead is not considered to be a principal threat under
the NCP; consequently, there is no expectation under the NCP that the lead be treated.
19.0 SELECTED REMEDY
The selected remedy for the Tar Creek OU4 Site is Alternative 5 - Voluntary Relocation, Phased
Consolidation, Chat Sales, and On-site Disposal.
19.1 Summary of the Rationale for the Selected Remedy
In consideration of the criteria used to evaluate the alternatives, EPA has selected Alternative 5 as the
Selected Remedy, with some minor modifications. [To emphasize the continuity in our remedy selection
process, and for convenience, EPA will continue to refer to the remedy selected in this ROD as Alternative
5.] Alternative 5 achieves risk reduction in the shortest time frames through a combination of voluntary
relocation and reducing the footprint of contamination in the distal areas.
Based on information currently available, EPA, the lead agency, has determined that the Selected Remedy
meets the threshold criteria (40 CFR § 300.430(f)(l)(i)(A)) and provides the best balance of tradeoffs
among the other alternatives with respect to the balancing criteria (40 CFR § 300.430(f)(l)(i)(B)). The EPA
expects the Selected Remedy to satisfy the statutory requirements of CERCLA section 121 (b), 42 U.S.C §
9621 (b), that is, the Selected Remedy will:
Be protective of human health and the environment;
Comply with ARARs for all media;
Be cost-effective; and
Utilize permanent solutions and alternative treatment technologies or resource recovery
technologies (such as recycling/reuse) to the maximum extent practicable.
Based on public comments received during the public meeting held to present the Proposed Plan and
comments received during the public comment period, the public voiced a strong opinion that voluntary
relocation be included in the selected remedy.
19.2 Description of the Selected Remedy
Following is a description of each component of the Selected Remedy. Although the EPA does not expect
significant changes to this remedy, the remedy may change "somewhat" during the remedial design and
construction processes. Any changes to the remedy described in this ROD would be documented using a
technical memorandum in the Administrative Record, an Explanation of Significant Differences, or a ROD
Amendment, as appropriate and consistent with the applicable regulations.
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19.2.1 Voluntary Relocation
Voluntary relocation will remove a limited populace from areas with concentrated sources of potential
exposure. Ultimately, risk will remain as will the exposure pathway for anyone who visits the source
materials, until such time as the remedial actions are completed. Members of the community who elect not
to participate in the voluntary relocation would remain in the area near sources of potential exposure.
Institutional controls shall be placed on the relocation target properties to enhance the protectiveness sought
through the voluntary relocation. The State has also agreed that the ODEQ will file a recordable notice of
remediation or related action, including an easement on each property acquired by LICRAT. Pursuant to
the State's authority under Oklahoma Statutes 27 A § 2-7-123(B), the recordable notice will identify all
engineering controls used to ensure the effectiveness of the remediation and will contain prohibitions
against engaging in any activities that cause or could cause damage to the remediation or the engineering
controls, or recontamination of the soil or ground water as well as restrictions on land use or other activities
that are incompatible with the remedy selected in this ROD. The State will be the responsible agency for
implementation and enforcement of this institutional control. The controls shall be in effect until the State
formally determines that the property is safe for reuse. Figure 9 presents the buyout boundary as
determined by the LICRA Trust.
The following elements define the voluntary relocation component.
• The remaining properties not addressed under the State buyout program will be addressed under the
selected remedy. Both residential and commercial properties are included. The voluntary relocation
will include properties built on restricted Indian land. As provided in WRDA, the voluntary relocation
will not follow URA regulations.
• The estimated number of properties being considered for the LICRA Trust buyout program is 744,
which consists of 678 residential and 66 commercial properties. On the assumption that the State
program can address the relocation of approximately 256 residential properties and 19 commercial
properties, a total of 422 residential properties and 47 commercial properties remain to be relocated
under the ROD (Oklahoma Office of the Secretary of the Environment, October 3,2007). In
addition, an estimated 100 residential properties that are located within the LICRAT buyout boundary,
but do not meet state buyout criteria, may need to be relocated under Alternative 5.
• Vacant lots will not be part of EPA's remedy for the relocation program. That is, this Selected
Remedy will not provide funding to help compensate owners of vacant lots.
• Structures that remain after residents have been relocated will be removed or demolished and disposed
by the LICRA Trust.
• The estimated timeframe for completion of the voluntary relocation of the remaining properties is less
than three years.
• EPA will not acquire property under this relocation program. The Selected Remedy will fund
LICRAT, through ODEQ, and LICRAT will purchase the properties at issue and carry out the
relocation effort with minimal EPA oversight.
• Final disposition of the properties will be determined by the LICRAT.
19.2.2 Chat Sales and Environmentally Acceptable Chat Use
Chat sales are hereby selected as a part of the CERCLA remedy. Continued chat sales will contribute to a
more cost effective CERCLA remedy because it will mean that there will be less chat remaining on-site
that must be addressed with more expensive remedial alternatives (i.e., remedial alternatives that are more
costly than chat sales). Moreover, continued chat sales will mean that less chat will be disposed of on-site.
The removal of chat through chat sales will reduce exposure risks. In addition, continued chat sales are
important to the Quapaw Tribe, the State, and the community. While EPA does not own any chat and will
not purchase any chat, it will assist chat sales participants as part of EPA's CERCLA remedy.
The continuation of chat sales is an integral part of the remedy for OU4. EPA recognizes that most private
chat/land owners may be able to sell their chat piles; however, due to the complicated ownership pattern,
and due to the restrictions on alienation that exist at the chat piles owned by Quapaw Tribe allottees, EPA
anticipates that Indian-owned chat sales will be managed pursuant to an agreement between the EPA and
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the DOI that will define roles and responsibilities. EPA can address the release of chat in accordance with
CERCLA authorities in a manner that will benefit chat/land owners and the environment.
While chat sales have occurred on and off Site for many years, EPA recognizes that chat sales could be
impeded by owners' fear of incurring CERCLA liability to the United States or others arising from
unanticipated adverse consequences associated with chat sales. To help allay the concerns regarding
potential future liability arising from the sale and transport of chat to off-site locations during the Chat Sale
Pilot Project, EPA entered into CERCLA administrative settlements with sellers of the St. Joe Pile,
providing a covenant not to sue from EPA for sales made in compliance with the terms of the agreement,
and providing contribution protection pursuant to CERCLA § 113(f)(2), 42 U.S.C. § 9613(f)(2). These
agreements were approved by the U.S. Department of Justice. Although the Agency wishes to make clear
that these agreements provide no protection from any liability already incurred on the basis of past acts or
current status, the agreements appear to have successfully facilitated chat sales during the Pilot Project, and
it is EPA's intention to extend that practice as chat is sold pursuant to the ROD, subject to coordination and
approval with the Department of Justice.
To ensure that Site chat sales continue and that chat is used in a manner that is protective of human health
and the environment, under all of the remedial alternatives considered by EPA (except the no further action
alternative) all Site chat that is used, on-site or off-site, must be managed according to the criteria provided
in the Chat Rule, 40 CFR Part 278, and its preamble.2 This means that EPA is including both the
regulations that apply to transportation construction projects and the preamble guidance that applies to non-
transportation, non-residential projects as requirements for the use of Site chat. Under the remedy selected
in this ROD, only the uses described in the preamble (including EPA's June 2007 fact sheet; EPA530-F-07-
016B) and the transportation construction project uses described in 40 CFR Part 278 will be allowed for
Site chat.
Transportation uses of chat
Although the codified sections of the Chat Rule apply only to chat used in federally funded transportation
construction projects, under this ROD, the regulations in the Chat Rule would apply to any transportation
construction projects using Site chat whether or not the chat is to be used in a transportation construction
project that is a federally funded transportation project.
Transportation construction projects, under the Chat Rule, are activities that relate to the construction of
roads and highways and include bases, sub bases, road surfaces, bridges, abutments, shoulders, and
embankments. They are not related to any residential use. In developing the Chat Rule regulations, EPA
evaluated all the transportation construction uses and concluded that chat used in hot, warm, or cold mix
asphalt, slurry seals, microsurfacing and in epoxy seals, or other uses of chat that are evaluated on a case-
by-case basis will be safe and environmentally protective.
Non-transportation uses of chat
Under this ROD, only certain non-transportation uses of Site chat described in the Chat Rule preamble and
the preamble-referenced fact sheet would be allowed. Specifically, under this ROD, Site chat used in non-
transportation projects could only be used in cement and concrete non-residential construction projects as
described in the preamble, and in applications that encapsulate the chat as a material for manufacturing a
safe product or as part of an industrial process (e.g., glass, glass recycling) where all waste byproducts are
properly disposed, as described in the June 2007 fact sheet. In addition, non-transportation cement or
concrete project material in question must, on a case-by-case basis, pass one of the two evaluation methods
described in the Chat Rule preamble guidance. The two evaluation methods concern testing the material
using the Synthetic Precipitation Leaching Procedure, or having a State environmental agency or EPA
conduct a site specific risk assessment with a public comment period (see the preamble to the Chat Rule for
more information).
2 The Chat Rule can be found at 72 Fed. Reg. 39235 (July 18, 2007). It can also be found at
http://www.epa.gov/epaoswer/other/mining/chat/.
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Record keeping requirements in 40 CFR Part 278 would apply to transportation uses and non-
transportation uses
The record keeping requirements of the Chat Rule would apply to both transportation and non-
transportation uses of Site chat under this ROD, with one addition. Under EPA's remedy, a party who
acquires chat for use must submit a copy of the written certification described in the Chat Rule to both the
State and to the EPA Remedial Project Manager (RPM) for OU4.3 While the Chat Rule requires
certification only to the State, EPA's proposed remedy would require certification to the RPM as well.
Chat sellers who fall under the regulatory control of Bureau of Indian Affairs (BIA) may elect to submit a
copy of the certification required by the BIA to the EPA RPM. EPA intends to hold free on-site seminars
explaining the requirements of the Chat Rule as they apply to the Site.
Please note that the use of chat according to the provisions of the remedy would not affect a person's
obligation to comply with existing State or Federal materials specifications or other requirements.
Chat that is taken off-site, must be sent only to a facility that complies with the Off-site Rule (40 CFR
§300.440). The term "facility" as used here includes locations utilized for transportation projects and non-
transportation projects.
Chat washing facilities are covered under the State of Oklahoma's general fugitive air and general non-
point source discharge regulations. The State's general permits require that fugitive dusts and runoff be
controlled in a fashion so that dusts do not leave the property line or the boundary of the construction
activity. These regulations exist and apply independent of this ROD.
NOTE: Although EPA's Proposed Plan described the substantive requirements of the State regulations
described in the preceding paragraph as ARARs, that was an inaccurate description. In fact, since chat
washing facilities will continue to operate independent of EPA's OU4 remedial actions, the State's general
permit provisions and other State, Federal and local regulations apply with the force of law (to the extent
that they did prior to the ROD) with respect to all on-Site chat washing facilities under these jurisdictions,
respectively. EPA will encourage local, state, and federal authorities to enforce Best Management Practices
and Storm Water Pollution Prevention Plans for facilities on the Site to ensure environmentally protective
chat processing operations.
Chat Sales
EPA is selecting the Chat sales program as outlined as part of the remedy for the Tar Creek Superfund Site.
Because chat sales are part of the remedy, EPA will facilitate activities to support chat sales that will
include the following:
a) The EPA will work with the DOI to facilitate sales of Indian-owned chat.
b) EPA will present a workshop to assist chat/land owners and sellers with chat sales.
c) EPA will provide sample chat sale agreements and site operating plans to chat/land owners and
chat processors.
d) EPA will answer questions about the Chat Rule.
e) EPA will provide technical review to any requests for chat use other than chat mixed in asphalt for
federal transportation projects.
f) EPA will conduct a risk assessment on chat materials that exceed the SPLP and proposed for use
in concrete as specified in the Chat Rule to support the ultimate sale of the chat.
g) EPA will coordinate with DOJ, as outlined above, regarding liability protection for chat/land
owners.
As a consequence of EPA's selection of chat sales as a part of the remedy for the Tar Creek Superfund Site,
the BIA, with the assistance of other agencies of the DOI, will manage and administer the following (DOI
letter dated September 28, 2007, from Mr. L. Michael Bogert to Regional Administrator Richard E.
Greene):
3 Certifications should be sent to Tar Creek Remedial Project Manager (6SF-R), U.S. EPA Region 6, 1445
Ross Avenue, Dallas, TX 75202-2733. Faxes may be sent to EPA at 214-665-6660.
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a) Perform engineering ownership determinations, cadastral surveys, and appraisals, if needed;
b) Outreach and communication with the Indian owners of restricted chat and land regarding chat
sales and surface leasing;
c) Appraisals of the fair market value of restricted chat and surface leases and provision of copies
thereof to the Indian chat owners and land owners;
d) Necessary tasks associated with the review and possible approval of chat sales contracts and
business site leases,
e) Quantitative analysis of chat removed from Indian-owned restricted chat piles for production
verification purposes;
f) Tasks associated with the accounting of funds and distribution of proceeds from the sale of
restricted chat to Indian owners;
g) Logistics associated with competitive or negotiated sales of Indian-owned restricted chat;
h) Assistance, as required in negotiations between Indian owners of restricted chat and potential chat
purchasers;
i) Coordination of sales and other issues with the relevant offices of Federal, State, and Tribal
governments; and
j) Review and enforcement of sellers' compliance with chat sales agreements and volumetric
recording of chat sales.
The Proposed Plan estimated cost included activities and costs associated with those activities in the
summary of remedial alternatives. EPA has determined since the Proposed Plan was issued that Hazardous
Waste Operations and Emergency Response Standards training will not be required at chat
processing/handling operations since these activities are already covered under the applicable Mine Safety
and Health Administration (MSHA) standards that are already in effect for these businesses.
Since chat sales is part of each action alternative considered, including the selected remedy, the cost
associated with activities facilitating chat sales was included in the net present value cost estimates for
these alternatives.
Based on current information, the EPA believes commercial chat sales will continue and will address the
largest part of the chat. For purposes of defining the remedy, EPA has assessed information from chat
processors and others in determining that approximately 95% of the chat will be removed from the site over
a 30 year period through commercial sales.
Under the remedy selected in this ROD, all chat in chat piles and chat bases that is not sold will be
excavated to the underlying native soil, transported and released to an on-site chat processor or future
processing location in a previously contaminated area of the Site, injected into mine workings, or it will be
disposed in an on-site repository. In distal areas, source material including chat piles, chat bases, and
historic haul roads and non-operating railroad grades will be excavated down to native soil, removed and
managed. EPA has decided that (along with relocation of residents) collection and management of distal
area source material, and excavation of in-stream source materials will be given top priority under this
ROD. The majority of the removed source material will be released to chat processors. Chat processors
who receive chat will be selected based on implementability factors and cost factors (e.g., processor
capacity or cost of transportation) that will be assessed in the Remedial Design. Once the chat is removed,
the native soils will be rebuilt using standard land practices. Chat located in streams will also be removed
and disposed in the same manner as chat in chat piles and chat bases. That is, it will be excavated to the
underlying native soil, transported and released to an on-site chat processor or future processing location in
a previously contaminated area of the Site, injected into mine workings, or it will be disposed in an on-site
repository. Under Alternative 5, EPA will seek permission for access to private properties and to remove
source materials for disposal. Chat/land owners who do not permit EPA to remove their chat will be
provided an opportunity to sell or otherwise plan for its disposition within the following limits. Chat/land
owners in distal areas (See Figure 3) who do not give EPA permission to remove their chat will be given
the opportunity to develop a plan under which they have up to five years to sell or otherwise dispose of
their chat. Chat/land owners of chat in streams who do not give EPA permission to remove their chat will
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be given the opportunity to develop a plan under which they have up to one year to sell or otherwise
dispose of their chat. EPA will work with chat owners to identify alternative chat disposition options.
19.2.3 Watershed-Based Approach
A watershed-based approach will be taken to address the potential effects remedial actions may have on the
local watersheds. A baseline hydrology model will be developed as part of the remedial design to reflect
the existing land uses in the basin and reflect any rainfall storage within the source materials. As source
materials are removed, the capacity of the soil and proposed land use to absorb rainfall will be evaluated.
The model may also be used as a planning and design tool to prepare a comprehensive watershed plan to
mitigate any potential runoff increases. Complete details of this approach and possible control and
mitigation measures will be formulated during the remedial design.
19.2.4 Phase 1 Elements
The following remedy elements will be undertaken in the first part of the remedial action as early response
actions. EPA plans that these Phase I elements will be completed in the first fifteen years of the OU4
remedial action4.
19.2.4.1 Remedial Actions in Distal Areas
Remedial Actions to Address Chat in Distal Areas
Chat found in chat piles, chat bases, mining era haul roads, and non-operating railroad grades in the distal
areas of the Site will be addressed early (within the first fifteen years after the completion of the Remedial
Design) in the remedial action process. This effort will be undertaken in order to substantially reduce the
overall footprint of contamination and to minimize the need for land use restrictions, institutional controls,
and operation and maintenance.
A subsequent and additional benefit derived from this action is the potential for water quality
improvements. Water quality should improve once the source material is removed from the distal areas
because the source material in these distal areas presently pollutes local watersheds. Distal areas of the Site
are generally rural and are outside of the high-density mining areas. The distal areas and the source
materials present were divided into a Northeast, Southeast, and the Elm Creek Distal Zones. Each of these
zones is associated with a local watershed. Figure 3 depicts these three distal zones and the associated
watersheds.
Within fifteen years, chat found in distal areas depicted in Figure 3 will be excavated down to native soils.
Chat present in chat piles and chat bases in the distal areas is estimated at 6,159,000 yd3. The excavated
chat will be excavated, transported and released to an on-site chat processor or future processing location in
a previously contaminated area of the Site, injected into mine workings, or it will be disposed in an on-site
repository. Components of the on-site repository will be developed during the Remedial Design and will
include measures to address infiltration, grading, and closure consistent with the State of Oklahoma non-
hazardous industrial waste landfill requirements. The source material at the Site is a non-hazardous
industrial waste (NHIW) under the Oklahoma Solid Waste Management Act (see 27A O.S. § 2-10-103),5
therefore, the substantive ODEQ requirements for construction of a NHIW landfill are an applicable
requirement for repositories constructed under this ROD on-site in areas that are not contaminated.
4 Time periods for the Remedial Action are all measured from the completion of Remedial Design.
Remedial Design is expected to take approximately three years. That is, when we say that Phase I should
be completed in fifteen years, we mean that it will be completed within fifteen years of the completion of
the Remedial Design. If the Remedial Design takes three years, as we anticipate it will, then it will be 18
years from the start of Remedial Design to the completion of the Remedial Action.
5 Appendix F to Chapter 515 of Title 252 of the ODEQ regulations say that Wastes exempted by the RCRA
Bevill waste exclusion in 40 CFR 261.4(b)(7) are non-hazardous industrial waste (NHIW).
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Upon excavation of chat, samples of the underlying and adjacent native soils will be collected and analyzed
to confirm that the remediation goals were met in these soils.
Owners of chat and/or the land where chat is present in distal areas will be contacted, and where these
owners agree, chat will be excavated, transported and released to an on-site chat processor or future
processing location in a previously contaminated area of the Site, injected into mine workings, or it will be
disposed in an on-site repository. If the owners will not release the chat for excavation and disposition,
they will be required to provide a plan and schedule for final disposition that is consistent with this ROD.
Disposition under the owner's EPA-approved plans must be completed within five years (unless the chat is
located in streams in which case, owners will have only one year to complete disposition under an EPA-
approved plan). EPA will work with chat owners to identify alternative chat disposition options.
In distal areas, soil cover will not be hauled in to backfill the excavated areas once occupied by chat or
contaminated soil. Rather, soils at the bottom of the excavated area will be rebuilt naturally to sustain
vegetation using standard land preparation practices such as ripping, contouring, adding amendments,
disking, fertilizing, planting, and seeding.
Remedial actions to Address Transition Zone Soils in Distal Areas
Transition zone soils (soils around and underneath source materials) that exceed the remediation goals will
be excavated to a depth no greater than 12" below the final grade established in the remedial design. The
final grade will consider land uses and site-wide hydrological impacts (See 19.2.3 Watershed Based
Approach). Removed soil may be used for interim cover at the on-site repository. In areas that are
excavated, nearby transition zone soils that do not contain concentrations of chemicals that exceed the
remediation goals will be used in the natural soil rebuilding process that is implemented after excavation.
The natural soil rebuilding process used to establish the final grade will include standard land practices
such as ripping, contouring, adding amendments, disking, fertilizing, planting and seeding.
19.2.4.2 Smelter Waste Remedial Actions
Smelter wastes will be excavated and disposed of in on-site repositories. These repositories will be
contoured to promote drainage upon closure, covered with clean soil and revegetated. Smelter-affected
soils will be managed in the same manner as transition zone soils as described above in Section 19.2.4.1.
Soils underlying excavated areas will be rebuilt naturally as described above under the Distal Area
discussion in Section 19.2.4.1.
19.2.4.3 Fine Tailings Remedial Actions
Fine tailings will be injected into mine workings or covered in place. The covered fine tailings may be
consolidated to reduce the footprint of the final cover. Due to the large size of the site, the wide range of
physical settings that fine tailings are located, and the difference in the sizes of the tailings ponds, it was
determined that a single approach would not be sufficient. Injection will be the preference for the fine
tailings, however, covering in place will be used for areas that injection is technically impracticable (e.g.,
adequate mine workings are not in close proximity or physical characteristics of the tailings are not
amenable to injection) or when the volume of tailings greatly exceeds the surface area (i.e., very deep
ponds). Based on existing site characterization data, and for cost evaluation purposes, EPA has estimated
that Central Mill and Central Mill north tailings ponds will be capped in-place (see Figure 11).
Injection will be implemented in a manner that complies with the underground injection control regulations
for a mine backfill well. As part of the process of ensuring such compliance, a site-wide hydrogeologic
study will be performed prior to implementation of the injection of fines or chat into the mine workings.
The study will address the requirements of the regulations and will examine whether there is hydraulic
connectivity between the Picher Field and the Commerce mine working, identify strategic subsurface
locations for injection in order to maximize the number of potential injection sites needed to adequately
alter the hydrogeology, and evaluate the long-term effectiveness of this method. The regulations pertaining
to Class V Injection Wells are applicable to this type of injection; consequently, the substantive
requirements of these regulations are ARARs for this aspect of the remedial action. Therefore, as part of the
remedial action, it must be determined whether the injection will cause the movement of a contaminant to
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underground sources of drinking water that would cause a violation of the primary drinking water
regulations (40 CFR Part 141). The use of injection prompts the study of ground water. Table 13 provides
additional information on compliance with the UIC regulations. Surface water quality will also be
monitored to determine if additional measures, like temporary water treatment, are needed.
The cover, where used, shall meet the substantive requirements of the ODEQ regulations at OAC 252:515-
19-53(a) or an equivalent alternative as determined by EPA consistent with OAC 252:515-19-53(c). The
requirements of OAC 252:515-19-53(a) include a barrier layer that is at least 24 inches of earthen material.
The requirements also include the installation of an erosion layer above the barrier layer. The erosion layer
is to be at least one foot of soil capable of sustaining plant growth.
For cost estimating purposes, it is assumed that the fine tailing ponds with the largest volume to surface
area ratio (i.e., very deep ponds) will be covered in place with a soil cover. Based upon this assumption, an
estimated 4,437,000 yd3 of fine tailings covering an area of 251 acres will be covered in place. Transition
zone soils associated with the fine tailing deposits (i.e., soils adjacent to the fine tailings and soils that
underlie the fine tailings) will be rebuilt as described in ROD Section 19.2.4.1 (Remedial Actions in the
Distal Areas).
19.2.4.4 Remedial Actions Addressing In-stream Source Materials
If Source Materials are found in Site streams such as Tar Creek, Lytle Creek, Elm Creek, or Beaver Creek,
they will be excavated to native soil and returned to their near stream origin. A flexible membrane liner
may be used in addition to, or instead of, excavation as determined by EPA. The remedial design will
consider factors such as bank slope stability problems due to excavating large volumes of material from the
stream bed and other hydrological factors in determining the areas for the flexible membrane liner.
Removed source materials will be returned to the nearby chat piles, chat bases, or tailings ponds from
which it appears that they came, as determined by EPA. Once in-stream fine tailings are returned to their
place of origin, these fine tailings will be addressed as provided in Section 19.2.4.3 (Fine Tailings
Remedial Actions). Once in-stream chat located outside the distal areas is returned to its place of origin,
the owners of this chat may sell it or otherwise dispose of it subject to the limitations described in Section
19.2.5.1 (Remedial Actions Addressing Unmarketable Chat). Once in-stream chat located in the distal
areas is returned to its place of origin, it will be addressed as provided in Section 19.2.4.1 (Remedial
Actions in Distal Areas). Until relocated source materials are sold or otherwise addressed (e.g. addressed
under Phase II section 19.2.5.1 (Remedial Actions Addressing Unmarketable Chat)), these source materials
will be contained using interim engineered controls to prevent them from migrating to surface water. These
engineered controls may include berms, sheet piling, or constructed wetlands. In locations where source
materials have been excavated from streambeds, erosion control measures will be installed, and these may
include gabion basket wire and rock embankments, boulders, or constructed wetlands. Figure 10 identifies
sections along Tar Creek that may require source material removal and engineering controls.
19.2.4.5 Remedial Actions Addressing Rural Residential Wells
Where concentrations of mining-related contaminants in water drawn from rural residential wells exceeds
0.015 milligrams per liter (mg/L) for lead, the remedy will be to provide an alternative water supply. Rural
households that are within the area that has been designated for relocation under the State of Oklahoma's
relocation program, but which do not elect to participate in the relocation program, would be eligible for an
alternative water supply (estimated two residences). Due to the uncertainty of water supply systems that
will remain after the relocation, the method for supplying the water will be determined during the Remedial
Design. If, as part of the remedial action, eligible households are connected to existing municipal or rural
water supplies, the owner/residents of these households would be responsible for payment of continued
water service and for household water system repairs. That is, the remedial action will provide the
connection to the alternative water supply to eligible households, but it will not pay for water service or for
household plumbing repairs or for system repairs.
19.2.4.6 Remedial Actions Addressing Rural Residential Yard Soil
Where rural residential properties that are not participating in the voluntary relocation program are found to
have lead concentrations in yard soils that exceed 500 parts per million (ppm), the yard soil will be
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excavated. The soil will be excavated to a maximum depth of 12-inches, the area backfilled with clean soil,
contoured to promote drainage, and revegetated. If contaminated soils are known to remain beyond the
excavation depth, a warning material (typically high-visibility orange construction fencing) will be placed
at the bottom of the excavation prior to backfilling. The warning material would serve to alter those
conducting future earthmoving activity.
19.2.4.7 Construction of On-site Repositories
On-site repositories will be constructed to accept Site source materials for final disposal. . The repositories
will cover an estimated 28 acres and will be capable of receiving an estimated 1,000,000 yd3 of source
materials, affected soils, and other Site-related materials such as wood, concrete, and miscellaneous debris.
The liners for on-site repositories that are not built in areas of contamination shall meet the substantive
requirements of the ODEQ regulations at OAC 252:515-1 l-2(b) unless an alternative is approved by EPA
consistent with OAC 252:515-1 l-2(c). The cover shall meet the substantive requirements of the ODEQ
regulations at OAC 252:515-19-53(a) or an equivalent alternative as determined by EPA consistent with
OAC 252:515-19-53(c). The requirements of OAC 252:515-19-53(a) include a barrier layer that is at least
24 inches of earthen material. The requirements also include the installation of an erosion layer above the
barrier layer. The erosion layer is to be at least one foot of soil capable of sustaining plant growth. For
cost estimating purposes, a clay liner, filter sand bed, and a soil cover are assumed although the actual
construction will be determined in the Remedial Design. Upon closure, repositories will be contoured to
promote drainage and revegetated.
19.2.4.8 Five-Year Reviews
The on-going remedy would be reviewed, at a minimum, every five years since hazardous substances
remain on-site with concentration levels that do not allow for unrestricted use and unrestricted exposure.
The remedy would be reviewed to assess the ability of the remedy to provide for the protection of human
health and the environment. As part of the review, EPA will also evaluate the progress of chat sales. Chat
piles and chat bases that remain and that are unmarketable will be identified and evaluated for commercial
viability. This determination will be made with input from the chat landowners, appropriate Tribal
representatives, and the commercial operators. Chat determined to be unmarketable will be addressed by
the Phase II remedial actions described below.
19.2.5 Phase 2 Elements
After Phase 1, the following long-term response actions and other measures will occur. The Phase 2
remedial action elements will be conducted in the final five years of the Remedial Action to maximize
active chat sales. Until a chat owner is notified (or effectively notified) that EPA intends to excavate the
owner's chat pile or chat base as provided in this ROD, EPA expects that chat owners will continue to sell
or use their chat subject only to the provisions of Section 19.2.2 (Environmentally Acceptable Chat Use).
19.2.5.1 Remedial Actions Addressing Unmarketable Chat
Within the heavily mined area or core of the Site, a significant volume of chat is unmarketable. This
unmarketable chat is typically found in small chat piles, chat bases, non-operating railroad grades, and
roadbeds. These small deposits often have chat that has the appropriate composition and quality for use in
asphalt mixes or other commercial products. However chat processors cannot profitably use this chat
because excavating the chat and hauling it to a processor would add so much to its cost that it could not be
sold at a price that can compete in the market. Also, there is not enough chat in these deposits to warrant
setting up chat washing equipment at the deposits. Under the selected remedy, owners of unmarketable
chat and/or the land on which the unmarketable chat is found will be contacted, and where these owners
agree, the chat will be excavated, transported and released to an on-site chat processor or future processing
location in a previously contaminated area of the Site, injected into mine workings, or it will be disposed in
an on-site repository.
For alternative comparisons and cost estimating, the volume of unmarketable chat was estimated at
9,380,000 yd3, or 24 percent of all chat for Alternatives 4 and 8, and 2,073,000 yd3, or 5% of all chat for
Alternative 5. For purposes of the cost estimate, "unmarketable chat" includes chat that is taken from a
small deposit to a chat processor, even though the chat processor will wash and sell the chat.
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If the owners will not release the unmarketable chat for disposition, they will be required to provide, for
EPA review and approval, a plan and schedule for final disposition. Disposition under the owner's plans
must be completed within five years. If EPA finds that the plan or schedule is unacceptable, EPA may take
legal action.
Under the selected remedy, soil cover will not be hauled in to backfill areas where unmarketable chat and
contaminated transition zone soil has been excavated. Instead, soils will be rebuilt naturally using standard
land preparation practices such as ripping, contouring, addition of amendments, disking, fertilizing,
planting, and seeding, until the excavated areas can sustain vegetation. In areas that are excavated, nearby
transition zone soils that do not contain concentrations of contaminants that exceed the remediation goal,
will be used in the natural soil rebuilding process that is implemented after excavation.
For cost estimating purposes, it is assumed that the unmarketable chat will be addressed in the following
manner:
• 90 percent, or 1,866,000 yd3, of the unmarketable chat will be excavated, transported and released to
an on-site chat processor or future processing location in a previously contaminated area of the Site
where it will be stockpiled until processed. When EPA said above in this ROD that Phase II is
anticipated to take approximately five years, we mean that was how long it would take for the
unmarketable chat to be managed. Once chat has been released to a commercial chat processor and
stockpiled, it may take well beyond ten years for it to be sold. However, EPA has found that chat
processors maintain chat in a controlled setting that prohibits the public from coming into contact with
the material. State and Federal health, safety and environmental laws apply to these chat processors.
The selected remedy under this ROD adds no additional requirements for chat processors in this regard
(other than the chat use requirements described in Section 19.2.2); however, EPA will review the
protectiveness of this situation as part of our Five-Year Review process. Once commercial chat
processing has ended at a given location, if source materials or contaminated soil remain, they will be
evaluated as part of the selected remedy. These potential future actions were not included in the cost
estimate for the selected remedy but it is anticipated that they will not be significant6
• 10 percent, or 207,000 yd3, will be excavated and sent to an on-site repository.
In addition to the above assumptions, all chat found in mining era haul roads that were built with chat and
all chat found in non-operating railroad grades will be excavated to the underlying native soil, transported
and released to an on-site processor or future processing location in a previously contaminated area of the
Site, injected into mine workings, or it will be disposed in an on-site repository. The estimated volume of
chat from haul roads and railroad grades, 702,000 yd3, is accounted for in the total estimated volume of
unmarketable chat.
19.2.6 Other Planned Actions Common to Both Phases
Under the selected remedy, institutional controls (ICs) and operation and maintenance activities will be
implemented at locations where Source Materials are covered in place. Locations where ICs and operation
and maintenance activities will be implemented include tailing ponds that are covered and the on-site
repositories which would be covered when closure is completed. Other ICs are included in the selected
remedy and are detailed in the following summary:
Location/Area IC
Applied
IC Objective
IC Instrument
Responsible
Organization
Covered Fine Tailings
Restrict future use of the
property to protect the
integrity of the
Deed Notice and
Easement filed pursuant
to Oklahoma Statute
ODEQ
For property where DOI
6 See EPA's Guide to Preparing Superfund Proposed Plans, Records of Decision, and Other Remedy
Selection Decision Documents, OSWER 9200.1-23P (July 1999) at p. 7-1 ("Feasibility Study cost
estimates are expected to provide an accuracy of +50 percent to -30 percent.")
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engineered cover
system.
21A § 2-7-123(B)
is the trustee, then ICs
will be established in
coordination with DOI.
On-site Repositories
Restrict future use of the
property to protect the
integrity of the
engineered containment
system.
Deed Notice and
Easement filed pursuant
to Oklahoma Statute
27A § 2-7-123(B)
ODEQ
For property where DOI
is the trustee, then ICs
will be established in
coordination with DOI.
Property Acquired via
Voluntary Relocation
Restrict future use of the
property to prevent
exposure of residential
or commercial
inhabitants to chemicals
above the Final
Remediation Goals
(Table 12).
Deed Notice and
Easement filed pursuant
to Oklahoma Statute
27A § 2-7-123(B)
ODEQ
The controls shall be in
effect until the State
determines that the area
is safe for reuse.
Shallow Ground Water
Restrict future uses of
ground water from the
portion of the Boone
aquifer (or shallower)
for potable or domestic
supply that is impacted
with site-related
contaminants above the
Final Remediation
Goals (Table 12).
Oklahoma Water
Quality Standards
Title 785, Chapter 45,
Appendix H
ODEQ
In addition to the instruments above, annual public notices will be published in area newspapers explaining
that some areas where source materials were removed may pose a risk if covered contaminated materials
are unearthed. These notices will tell where additional information may be obtained.
Monitoring of ambient and near-source air, surface water, ground water, or sediment will be completed as
appropriate as determined by EPA during remedial action activities. Pilot projects and treatability studies
(e.g., the chat sales pilot project) will continue through completion of the Remedial Design. To help
eliminate the possibility of potential exposure to Site source materials, community education and awareness
activities will be conducted throughout the duration of the remedial actions. These activities will include,
but not be limited to, the following:
- Outdoor billboards located near chat piles that have been used in the past for recreation, warning of the
dangers associated with playing on chat piles.
- Biannual notices in utility bills warning of the dangers of chat use in residential areas, and warning people
to stay off of chat piles.
- In-school programs to warn children to stay off of chat piles.
- Outreach to community churches, and social groups.
19.3 Summary of the Estimated Remedy Costs
The estimated cost for the selected remedy is $167,288,000. A detailed breakdown of the estimated costs is
presented in Table 11. The cost summary tables are based on the best available information regarding the
anticipated scope of the remedial action. Changes in the cost elements are likely to occur as a result of the
new information and data collected during the remedial design phase. Major changes may be documented
in the form of a memorandum to the Administrative Record file, an Explanation of Significant Differences
(ESD), or a ROD amendment. The projected cost is based on an order-of-magnitude engineering cost
estimate that is expected to be within +50 or -30 percent of the actual project cost. In the future, if injection
of chat and fine tailings is found to be a viable disposal option, the cost of the remedy may change.
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19.4 Expected Outcomes of the Selected Remedy
Following are the expected outcomes of the Selected Remedy in terms of resulting land uses, the remedial
action objectives (RAOs), the risk reduction achieved as a result of the response action, and the anticipated
impact on the local community.
19.4.1 Available Uses of Land
Once the Remedial Action Objectives (RAOs) (including the Remediation Goals) are met on a given piece
of Site property, the land in question should be acceptable for use as residential property for the general
public, subject to any institutional controls. Institutional controls (ICs) may include restrictions established
by the LICRA Trust, and any easements established by ODEQ under Oklahoma Statutes 27A § 2-7-123(B).
As explained above, ODEQ will establish such easements in areas under State jurisdiction where source
materials are covered on-site. For property where DOI is the trustee, ICs will be developed by EPA in
coordination with DOI. EPA estimates that RAOs will be met for the entire site in about 30 years (i.e., 30
years after the completion of the Remedial Design phase); however, discrete areas of the Site will meet
RAOS, and be available for residential use (subject to ICs) as the remedy proceeds.
19.4.3 Final Remediation Goals
Table 12 provides the remediation goals for the COCs in soil, Source Material, and in water at the tap.
20.0 STATUTORY DETERMINATIONS
Under CERCLA §121 and the NCP §300.430(f)(5)(ii), the EPA must select remedies that are protective of
human health and the environment, comply with ARARs (unless a statutory waiver is justified), are cost-
effective, and utilize permanent solutions and alternative treatment technologies or resource recovery
technologies to the maximum extent practicable. In addition, CERCLA includes a preference for remedies
that employ treatment that permanently and significantly reduce the volume, toxicity, or mobility of
hazardous wastes as a principal element and a bias against off-site disposal of untreated wastes. The
following sections discuss how the Selected Remedy meets these statutory requirements.
20.1 Protection of Human Health and the Environment
The Selected Remedy will be protective of human health and the environment. The remediation goal for
lead in soils and source material will meet EPA's goal to reduce exposure to lead such that a typical child
(or a hypothetical child) or group of similarly exposed children have a risk of no more than 5 % of
exceeding a blood lead level of 10 micrograms per deciliter (|ig/dL). In addition, meeting the Remediation
Goals for zinc and cadmium will be protective for terrestrial fauna.
There are no short-term threats associated with the Selected Remedy that can not be controlled. In
addition, no adverse cross-media impacts are expected from the Selected Remedy.
20.2 Compliance with Applicable or Relevant and Appropriate
Requirements
Section 121(d) of CERCLA and the NCP §300.430(f)(l)(ii)(B) require that remedial actions at CERCLA
sites at least attain legally applicable or relevant and appropriate Federal and State requirements, standards,
criteria, and limitations which are collectively referred to as "ARARs," unless such ARARs are waived
under CERCLA §121(d)(4).
The selected remedy will comply with all ARARs through the use of standard engineering and waste
management techniques as well as through the implementation of a Site-specific Health and Safety Plan.
The selected remedy will meet ARARs from Federal and State laws.
A summary of ARARs and "to be considereds" criteria for the selected remedy are presented in Table 13.
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20.3 Cost-Effectiveness
The Selected Remedy (Alternative 5) is cost-effective because the remedy's costs are proportional to its
overall effectiveness (see 40 CFR §300.430(f)(l)(ii)(D)). This determination was made by evaluating the
overall effectiveness of those alternatives that satisfied the threshold criteria (i.e., that are protective of
human health and the environment and comply with all Federal and any more stringent State ARARs).
Overall effectiveness was evaluated by assessing three of the five balancing criteria in combination (long-
term effectiveness and permanence; reduction in toxicity, mobility, and volume through treatment; and
short-term effectiveness). The overall effectiveness of each alternative was then compared to each
alternative's costs to determine cost-effectiveness. The relationship of the overall effectiveness of
Alternative 5 was determined to be proportional to its costs and, consequently, Alternative 5 represents a
reasonable value for the money to be spent. As explained below, Alternative 5 is also the least expensive
of the action alternatives, comparing present values.
WRDA has helped make Alternative 5 with relocation a cost-effective remedy. Except for the
relocation element, Alternative 5 is the same as Alternative 4 which was identified as EPA's preferred
alternative in the Proposed Plan. Unlike Alternative 4, Alternative 5 includes voluntary permanent
relocation of the remaining residents of Picher, Cardin and Hockerville. With the passage of WRDA,
certain cost avoidance can be realized, and this makes Alternative 5 more cost effective than the other
alternatives considered. This cost avoidance includes the following:
• WRDA eliminates URA expenses, saving $42,997,900.
WRDA provides that a Tar Creek Superfund Site remedial action that includes permanent
relocation is not subject to the URA. This means that the remaining residents and businesses in
Picher, Cardin, and Hockerville can be relocated, by LICRAT, as part of the remedial action at a
cost of $42,058,100 instead of $85,056,000 as was projected in the Proposed Plan—a difference
of $42,997,900.
• With relocation, certain elements of the remedy can occur later. The time value of these
later expenditures results in a $42,505,100 savings.
Supported by requests from the State, the Tribe and the community, EPA's goal is to prevent
another generation of residents living near the source materials from being exposed; consequently,
EPA initially limited the remedial action to a 20-year period. That is, in the Proposed Plan our
preferred alternative (which did not include relocation) called for remedial action to be complete
in 20 years. Under the selected remedy, however, EPA will be permanently relocating residents
who live near the large concentrations of source material; consequently, EPA can extend the
remedial action, and allow chat sales to continue for an additional ten years. This ten-year
extension means that certain planned activities will take place later in the remedial action, and,
when spending happens later, there are savings associated with the increased value of money over
time. To demonstrate, it is useful to compare the present value of Alternative 5, not including
relocation, to the present value of Alternative 4. (Remember that Alternative 5 without relocation
is essentially the same as Alternative 4.) The present value of Alternative 4 is $167,735,000. The
present value of Alternative 5 (with relocation expenses removed from the total costs) is
$125,230,000. The $42,505,000 difference in present values represents the time value of incurring
costs at a later date. In short, Alternative 5 takes the at risk population out of the immediate area
which greatly reduces the chances of exposure, and, with the threat of exposure greatly reduced,
this means that chat sales, the least expensive acceptable means of source removal, can continue
for a longer period, and more expensive remedy elements can be performed later. With later
performance of expensive remedy elements, the present value of Alternative 5 is greatly reduced.
(For purposes of this analysis, EPA assumes that essentially all residents will accept relocation.)
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STEPS IN THE COST EFFECTIVENESS ANALYSIS
A remedial alternative is cost-effective if its "costs are proportional to its overall effectiveness" (40 CFR
300.430(f)(l)(ii)(D)), and this is determined in two steps. In step one, overall effectiveness of a remedial
alternative is determined by evaluating the following three of the five balancing criteria: long-term
effectiveness and permanence; reduction in toxicity, mobility and volume (TMV) through treatment; and
short-term effectiveness. In step two, overall effectiveness is then compared to cost to determine whether
the remedy is cost-effective (id.). EPA has taken these two steps for OU4 as described below, and EPA has
come to the conclusion that the NCP (40 CFR 300.430(f)(l)(ii)(D)) cost-effectiveness analysis favors
Alternative 5 (Voluntary Relocation, Phased Consolidation, and On-site Disposal). Our two-step cost-
effectiveness analysis appears below:
A. Step one: Evaluate Overall Effectiveness under these criteria: a) lons-term effectiveness and
vermanence: b) reduction in toxicity, mobility and volume (TMV) through treatment: and c)
short-term effectiveness
1) Long-term effectiveness and permanence: Alternative 4 and 5 have greater long-term
effectiveness and permanence over a larger area compared to the other remedial alternatives
evaluated
Under CERCLA, EPA is required to select remedies that utilize permanent solutions to the maximum
extent practicable. See 42 U.S.C. § 9621(b)(1). In ROD Section 17.3, EPA compared the remedy
alternatives considered for this ROD under the long-term effectiveness and permanence criterion. EPA
evaluated each alternative along a continuum (i.e., each alternative was viewed as offering a greater or
lesser degree of long-term effectiveness and permanence). EPA determined that the remedial alternatives
ranked as follows (see infra Section 17.3):
RANK
1-Alternative 5 -The Selected Remedy (Voluntary Relocation, Phased Consolidation, and
On-site Disposal) and Alternative 4 (Phased Consolidation, and On-site Disposal) -
Alternatives 4 and 5 call for rapid consolidation of chat bases and small chat piles from
the distal areas. They also call for covering fines in place. As explained above,
Alternatives 4 and 5 will leave the smallest footprint of contained contaminant source
material of any alternative. Since there are uncertainties associated with the use of land
disposal for providing long-term protection from residuals, this means that of the
alternatives evaluated, Alternatives 4 and 5 have the greatest long term effectiveness
and permanence.
2-Alternative 8 (Total Source Consolidation, Stabilization, and Institutional Controls) -
This alternative calls for the most source material to be contained on-site;
consequently, fewer areas are excavated to native soil and a larger footprint of
contained contaminated source material would remain.
3-Alternative 1 - No Action - Under the No Action alternative, source materials remain
in place, and, since EPA has documented ecological and human health risk, the no
action remedy is not an effective or permanent remedy.
2) Reduction in toxicity, mobility and volume through treatment is not relevant to our cost-
effectiveness analysis for OU4
The type of mining waste and mill waste that will be addressed at OU4 is a high volume low-level threat
waste and EPA expects to use engineering controls instead of treatment for this type of waste under all the
alternatives evaluated. See 40 CFR § 300.430(a)(l)(iii)(B). Consequently, this criterion-- reduction in
toxicity, mobility and volume through treatment, is not relevant to the evaluation of cost effectiveness. No
treatment is involved in any of the evaluated alternatives.
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3) Short-term effectiveness of the remedial alternatives analyzed. Alternative 5 has the greatest
short-term effectiveness.
Under this criterion, the short-term impacts of alternatives shall be assessed considering the following:
(i) Short-term risks that might be posed to the community during implementation of an alternative; (2)
Potential impacts on workers during remedial action and the effectiveness and reliability of protective
measures; (3) Potential environmental impacts of the remedial action and the effectiveness and reliability of
mitigative measures during implementation; and (4) Time until protection is achieved. EPA undertook this
s four-part analysis in ROD Section 17.4, and Alternative 5 clearly had the greatest short term
effectiveness, followed by Alternative 8, and Alternative 4. Alternative 1 is not effective in the short term.
Summary: Alternative 5 has the greatest overall effectiveness
Under Alternative 5, EPA anticipates a greater degree of long-term effectiveness, and, therefore,
permanence than any of the other remedies (except Alternative 4 which is the same except for relocation)
because, under Alternative 5 (and Alternative 4), more areas of OU4 will be excavated to native soil,
requiring no operation and maintenance to maintain protection. In addition, Alternative 5 has the greatest
short-term effectiveness because the population that is most at risk will be relocated. Since reduction in
toxicity, mobility, and volume is equivalent under all the alternatives, it is apparent that Alternative 5 has
the greatest overall effectiveness of any of the alternatives evaluated.
B. Step two: Compare overall effectiveness to cost to determine whether the remedy is cost-effective
Once the overall effectiveness of the various remedial alternatives is determined, as EPA has done above in
Step 1, overall effectiveness is then compared to cost to ensure that the remedy is cost-effective. A remedy
shall be cost-effective if its costs are proportional to its overall effectiveness. See 40 CFR §
300.430(f)(l)(ii)(D). In the preamble to the NCP, EPA says this about the use of the term "proportional" in
determining cost effectiveness:
EPA uses the term "proportional" because it intends that in determining whether a
remedy is cost-effective, the decision-maker should both compare the cost to
effectiveness of each alternative individually and compare the cost and effectiveness of
alternatives in relation to one another (see 53 Fed. Reg.51427-28). In analyzing an
individual alternative, the decision-maker should compare, using best professional
judgment, the relative magnitude of cost to effectiveness of that alternative. In comparing
alternatives to one another, the decision-maker should examine incremental cost
differences in relation to incremental differences in effectiveness. Thus, for example, if
the difference in effectiveness is small but the difference in cost is very large, a
proportional relationship between the alternatives does not exist. The more expensive
remedy may not be cost-effective. EPA does not intend, however, that a strict
mathematical proportionality be applied because generally there is no known or given
cost-effective alternative to be used as a baseline. EPA believes, however, that it is useful
for the decision-maker to analyze among alternatives, looking at incremental differences.
EPA believes that using the term "proportional" describes well this type of
multidimensional analysis. Using such an analysis should enable the decision-maker to
determine whether an alternative represents a reasonable value for the money; more than
one alternative may be considered cost-effective.
Table 14 compares the overall effectiveness of each alternative to its cost7 and to the costs of the
other alternatives to see whether the cost of each alternative is proportional to its effectiveness.
Based on the analysis summarized in the table, only Alternatives 4 and 5 have been determined to
be cost effective.
7 In the future, if injection of chat and fine tailings is found to be a viable disposal option, the cost of the
remedy may change.
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20.4 Utilization of Permanent Solutions to the Maximum Extent Practicable
Under the NCP, each remedial action shall utilize permanent solutions and alternative treatment
technologies or resource recovery technologies to the maximum extent practicable. This requirement shall
be fulfilled by selecting the alternative that is protective of human health and the environment, that meets
ARARS, and that provides the best balance of trade-offs among alternatives in terms of the five primary
balancing criteria. (The balancing criteria are: 1) long term effectiveness; 2) reduction of toxicity mobility
and volume through treatment; 3) short-term effectiveness; 4) implementability; and 5) cost.). The
balancing shall emphasize long-term effectiveness and reduction of toxicity, mobility, or volume through
treatment. The balancing shall also consider the preference for treatment as a principal element and the bias
against off-site land disposal of untreated waste. In making the determination under this paragraph, the
modifying criteria of state and tribal acceptance and community acceptance shall also be considered. See
40 CFR § 300.430(f)(l)(ii)(E) ("Tribal" acceptance is added to State acceptance per 40 CFR § 300
.515(b)). In this case the Tribe with jurisdiction over part of OU4 is the Quapaw Tribe of Oklahoma.).
None of the remedial alternatives include treatment since the mining waste and mill waste at OU4 is a high
volume low-level threat waste and EPA expects to use engineering controls instead of treatment for this
type of waste (see 40 CFR § 300.430(a)(l)(iii)(B)). Consequently, the second balancing criterion listed in
the preceding paragraph is not germane. Moreover, none of the alternatives use off-site land disposal, so
that is not a consideration either. In addition, since all of the remedial alternatives (except the clearly
unacceptable no action alternative) are protective and all meet ARARs, these provisions are not a factor in
the 300.430(f)(l)(ii)(E) analysis either.
In short, as explained in the preceding paragraph, as EPA completes the balancing analysis, the only
pertinent criteria are: 1) long term effectiveness; 2) short term effectiveness; 3) implementability; and 4)
cost. Also, as we complete our analysis, we can disregard Alternative 1, the no-action alternative, since it
does not meet ARARs and is not protective. We can also disregard Alternative 8 since, as explained above
in ROD Section 20.3, it is not cost-effective.
This means that our balancing is limited to Alternatives 4 and 5. Here is how these two alternatives
compare under the pertinent criteria listed in the preceding paragraph:
Criterion
Discussed in ROD Section:
Conclusion
Long-term effectiveness
17.3
Alternative 4 and 5 are equivalent
Short-term effectiveness
17.5
Alternative 5 is clearly superior
Implementability
17.6
Alternative 4 is slightly more
easy to implement
Cost
17.7, and 20.3
Alternative 5 costs the least and is
most cost-effective
Overall
Alternative 5 is best overall
For the reasons described in our above analyses in ROD Sections 20.3 and 20.4 (see 40 CFR §§
300.430(f)(l)(ii)(D) and (E)), of these two alternatives that are protective of human health and the
environment and that are ARAR-compliant, the alternative that affords the best combination of attributes is
Alternative 5 (Voluntary Relocation, Phased Consolidation, and On-site Disposal), which is also the least
expensive of the action alternatives. Moreover, only Alternative 5 includes relocation of the most at-risk
population from the area, and relocation is strongly favored in comments EPA received from the affected
community (as a matter of policy, EPA places the highest priority on comments received from the
community to which the site potentially or actually poses a human health or environmental risk), from the
Quapaw Tribe and from the State.
In addition, under EPA's policy, relocation is generally justified to address an immediate risk to human
health (where an engineering solution is not readily available). See Interim Policy on the Use of Permanent
Relocations as Part of Superfund Remedial Actions, OS WER Directive: 9355.0-71P (June 30, 1999). At
OU4, the engineering solution (i.e., source removal) will take decades under any of the proposed remedies;
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consequently, permanent relocation is warranted. Accordingly, EPA is identifying Alternative 5 (Voluntary
Relocation, Phased Maximum Consolidation and On-site Disposal) as the selected remedy in this ROD.
In selecting Alternative 5 as its selected remedy, EPA recognizes the substantial role that States, Indian
Tribes, and the community play in the remedial process. When EPA is the lead agency, States and Tribes
participate as the support agencies and consult with EPA. In their consultation role, States and Tribes are
involved in developing the remedial alternatives for the site and in developing the option that will be put
forward as the preferred alternative in the Proposed Plan. The NCP (at 40 CFR § 300.430(f) and at 40 CFR
§ 300.515(b)) provides for consideration of State and Tribal concerns throughout the remedial process,
noting that the EPA shall consider State and Tribal and community comments regarding the lead agency's
evaluation of alternatives with respect to the other criteria, and these comments may prompt the EPA to
modify aspects of the preferred alternative identified in the Proposed Plan or decide that another alternative
provides a more appropriate balance. See 40 CFR § 300.430(f)(4)(i). [The NCP, at 40 CFR § 300.515(b)
allows Indian Tribes to be treated the same as States in the remedial process if certain conditions are met,
thus ensuring the Indian Tribes have the opportunity to review and comment on significant documents such
as RI/FSs, and RODs (see 55 Fed. Reg. 8730)].
20.5 Preference for Treatment as a Principal Element
The type of mining waste and mill waste that will be addressed at OU4 is a high volume low-level threat
waste and EPA expects to use engineering controls instead of treatment for this type of waste under all the
alternatives evaluated. See 40 CFR § 300.430(a)(l)(iii)(B). Consequently, the statutory preference for
treatment would not be met under any of the evaluated alternatives including the selected remedy.
20.6 Five-Year Review Requirements
Section 121(c) of CERCLA, 42 U.S.C. § 9621(c), and the NCP at 40 CFR §300.430(f)(5)(iii)(C) provide
the statutory and regulatory bases for conducting five-year reviews. Because this remedy will result in
hazardous substances remaining on-site in the ground water and in the soils above levels that allow for
unlimited use and unrestricted exposure, a statutory review will be conducted within five years after
initiation of the remedial action to ensure that the remedy is, or will continue to be, protective of human
health and the environment.
21.0 DOCUMENTATION OF SIGNIFICANT CHANGES FROM PREFERRED
ALTERNATIVE OF PROPOSED PLAN
If a Selected Remedy involves a significant change to a feature of the Preferred Alternative proffered to the
public in the Proposed Plan for a Superfund Site, EPA's policy is that the ROD is to indicate the significant
changes made, and should provide a rationale for the changes (e.g., new information or arguments provided
in public comments). In this case, EPA generally did not change the Preferred Alternative, but only added
to it (i.e., EPA added relocation and new timeframes for implementation). In addition, the inclusion of
relocation could have been reasonably anticipated based on the extensive discussions of relocation
originally presented in the Proposed Plan, in the Remedial Investigation and Feasibility Study Reports
(RI/FS), and in the Administrative Record file.
As part of its OU4 Proposed Plan (July 24, 2007), EPA considered relocation as a possible alternative.
Alternative 5 was EPA's relocation alternative under the Proposed Plan, and it was rejected because it was
not found to be cost-effective. With the passage of WRDA, however, two important aspects of relocation
have changed. First, WRDA authorized $30 million for relocation, appropriation of this authorized amount
will greatly reduce the number of residents that EPA would have to relocate. Second, under WRDA EPA
will not have to apply the Uniform Relocation Act (URA), and this will enable EPA to more efficiently
undertake or fund relocation. In addition, comments submitted by the State, the Tribe, and the affected
community on EPA's Proposed Plan strongly favored relocation.
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As it prepared this ROD, EPA reconsidered relocation in light of the developments described in the
preceding paragraph and based on the most recent information available from the LICRA Trust. As
explained above in ROD sections 20.3 and 20.4, EPA determined that relocation is cost-effective and
provides the best balance of trade offs among the remedial alternatives considered. Accordingly, EPA made
Alternative 5 (Voluntary Relocation, Phased Consolidation, and On-site Disposal) its selected remedy.
In the Proposed Plan for OU4, EPA proposed using source materials as fill in subsided areas. The use of
placing source material in subsided areas is eliminated from the ROD due to the long-term effectiveness of
this technique in the Picher and Commerce area. The Proposed Plan assumed a small percentage of source
material would be disposed in subsidence areas, therefore, the change in the overall strategy for the remedy
is minimal.
22.0 STATE ROLE
The ODEQ, on behalf of the State of Oklahoma, has reviewed the various alternatives as outlined in the
ROD and has indicated its support for the Selected Remedy. The State reviewed and commented on the
RI/FS, the BHHRA, the Proposed Plan and the ROD, and has determined that the Selected Remedy is in
compliance with ARARs and State environmental laws and regulations.
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PART 3: RESPONSIVENESS SUMMARY
23.0 RESPONSIVENESS SUMMARY
The United States Environmental Protection Agency (EPA) has prepared this Responsiveness Summary
for the Tar Creek Superfund Site, and is making it available to the public with the Record of Decision
(ROD) of Operable Unit 4 (OU4) of the Tar Creek Superfund Site (the "Site") located in Ottawa County,
Oklahoma. This Responsiveness Summary summarizes significant comments, criticisms, and new relevant
information submitted during the public comment period (described below) regarding EPA's July 29, 2007,
Proposed Plan and the supporting analysis and information for the remediation of OU4.
Pursuant to Section 117 of the Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA), 42 U.S.C. § 9617, EPA has provided a written notice and brief analysis of the Proposed Plan
and made the Proposed Plan available to the public. Also pursuant to Section 117, EPA has provided a
reasonable opportunity for submission or written and oral comments and an opportunity for a public
meeting near the Site regarding the Proposed Plan and regarding cleanup standards including without
limitation remedial action goals and remedial action objectives.
Overview of Public Comment Period
EPA issued its Proposed Plan detailing the preferred recommendations for OU4 for public review and
comment on July 29, 2007. EPA published a notice of availability and brief analysis of the proposed plan
in a major local newspaper of general circulation Miami News Record on July 28, 2007. This same
newspaper announcement told of a public meeting that was held at the Picher-Cardin High School
Commons as described below, and announced a 30-day public comment period (July 30, 2007 to date
August 30, 2007) on the proposed plan and the supporting analysis and information. Another newspaper
announcement was published in the Miami News Record on August 26, 2007, and this announcement
extended the public comment period an additional 32 days until October 1, 2007.
Documents containing factual information, data and analysis that may form a basis for the selection of the
remedial action for OU4 were made available to the public on July 30, 2007 in three Administrative Record
File locations, including the Miami Public Library located in Miami, Oklahoma, near the Site. The EPA
conducted a public meeting regarding the proposed plan and regarding supporting analysis and information
to receive comments and answer questions on August 28, 2007, at the Picher-Cardin High School
Commons located in Picher, Oklahoma. The meeting was in accordance with CERCLA Section 117(a)(2),
42 U.S.C. §9617(a)(2), and 40 C.F.R. §300.430(f)(3). Oral comments were accepted at the public meeting,
and a transcript of this meeting is included in the Administrative Record and is available on the internet at:
http://www.epa.gov/region6/6sf/pdffiles/transcript tar creek public meeting 8-28-07.pdf
Administrative Records are maintained at information repositories located at Miami Public Library located
in Miami, Oklahoma, EPA-Region 6 Office, and the Oklahoma Department of Environmental Quality.
Miami Public Library
200 North Main St
Miami, OK 74354
918-542-3064
Oklahoma Department of Environmental Quality
707 North Robinson
Oklahoma City, OK 73102
405-702-1000
U.S. Environmental Protection Agency - Region 6
1445 Ross Ave
Dallas, TX 75202
214-665-6427 (Please call for an appointment if you desire to review the file)
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Highlights of EPA's community outreach efforts are available in Section 23.3.
23.1 Summary and Response to Local Community Concerns8
Comment 1: One commenter said "Your plan premise is good, though I don't think it will solve the
root of the problem as a whole. Removing chat and chat usage will spread contamination."
In a similar comment, the commenter said that the commenter opposes chat sales on the grounds that use of
chat will eventually enter the environment.
Response: The selected remedy for Operable Unit 4, once completed, will effectively remediate over
4,241 acres of source material (see definition in Glossary of Terms in this ROD) to address human health
and ecological risk on OU4. Though certain areas containing source material will require institutional
controls, the implementation of this action will allow unrestricted land use in most remediated areas. To
ensure that chat is used in a manner that is protective of human health and the environment, under the
selected remedy, all Site chat that is used, on-site or off-site, must be managed according to the criteria
provided in the Chat Rule, 40 CFR Part 278, and its preamble.9 This means that we are including both the
regulations that apply to transportation construction projects and the preamble guidance that applies to non-
transportation, non-residential projects as requirements under the proposed plan as requirements for the use
of Site chat. Under the remedy selected in this ROD, only the uses described in the Chat Rule preamble
(including EPA's June 2007 fact sheet; EPA530-F-07-016B) and the transportation construction project
uses described in 40 CFR Part 278 will be allowed for Site chat. As explained in the preamble to the Chat
Rule, these uses will be protective. Chat that is not sold, for example a chat base that remains after most of
a chat pile is sold, will be disposed on-site in repositories. On-site repositories will be constructed to accept
Site source materials for final disposal. The repositories will cover an estimated 28 acres and will be
capable of receiving an estimated 1,000,000 yd3 of source materials, affected soils, and other Site-related
materials such as wood, concrete, and miscellaneous debris. The liners for on-site repositories that are not
built in areas of contamination shall meet the substantive requirements of the ODEQ regulations at OAC
252:515-1 l-2(b) unless an alternative is approved by EPA consistent with OAC 252:515-1 l-2(c). The
cover shall meet the substantive requirements of the ODEQ regulations at OAC 252:515-19-53(a) or an
equivalent alternative as determined by EPA consistent with OAC 252:515-19-53(c). The requirements of
OAC 252:515-19-53(a) include a barrier layer that is at least 24 inches of earthen material. The
requirements also include the installation of an erosion layer above the barrier layer. The erosion layer is to
be at least one foot of soil capable of sustaining plant growth, comply with the Oklahoma Solid Waste
Management Act Title 252 OAC, Chapter 515 for construction of a non-hazardous industrial waste landfill
or the equivalent as determined by EPA. As explained in ROD Section 19.2 (Description of the Selected
Remedy), some chat may also be injected into underground mines which should virtually eliminate the
chance of human exposure. In these ways we will ensure that chat that is removed will not spread
contamination.
Comment 2: The mines that feed into Tar Creek are not examined in your plan. Unless you start with
the mines that feed Tar Creek, while simultaneously cleaning the chat and treating neighboring areas, you
won't solve the problem.
Response: OU4 generally is not intended to address mine water or the surface water and sediment in
Tar Creek. However, the excavation of in-stream source material and the erosion control measures that
will be taken under OU4 to address near-stream source material should eliminate principal sources of
surface water and sediment contamination in Tar Creek and other Site streams.
8 EPA received a letter dated February 13, 2008, from the Quapaw Tribe of Oklahoma. Their concerns are
addressed in this ROD.
9 The Chat Rule can be found at 72 Fed. Reg. 39235 (July 18, 2007). It can also be found at
http://www.epa.gov/epaoswer/other/mining/chat/.
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Comment 3: One commenter said that EPA should consider use of encapsulation technology provided
by the Environmental Toxins Solution, Inc. Company to contain site contaminants. Another commenter
said that EPA should consider use of Laura's Mix, a new innovative solidification technology for
remediation at Tar Creek OU 4.
Response: EPA is always interested in learning more about innovative technologies that offer
permanent and cost effective solutions for contaminants at any Superfund site. Over the years, EPA has
met with multiple vendors and heard and learned more about various proposals and technologies that were
proposed to EPA as solutions for source material at the Site. Unfortunately, a number of the proposals that
were presented did not have documentation to support the claimed findings. Nonetheless, under the ROD,
in addition to the transportation uses of chat that are described, Site chat may also be used in cement and
concrete non-residential construction projects as described in the preamble to the Chat Rule, and in
applications that encapsulate the chat as a material for manufacturing a safe product or as part of an
industrial process (e.g., glass, glass recycling) where all waste byproducts are properly disposed, as
described in the June 2007 fact sheet. Non-transportation cement or concrete project material in question
must, on a case-by-case basis, pass one of the two evaluation methods described in the Chat Rule preamble
guidance. The two evaluation methods concern testing the material using the Synthetic Precipitation
Leaching Procedure, or having a State environmental agency or EPA conduct a site specific risk assessment
with a public comment period (see ROD Section 19.2.2 (Environmentally Acceptable Chat Use); and see
the preamble to the Chat Rule for more information). In short, chat uses that meet these various criteria
may be used to contain contaminants. If the technologies that the commenters describe meet these criteria,
they may also be used.
Comment 4: Your statement says, "clean up Tar Creek and protect the people..." The greatest
"protection" you can provide the current residents of this community is the opportunity to relocate through
the Federal Buyout already in progress here.
Response: The voluntary buyout being implemented by the Lead Impacted Communities Relocation
Assistance Trust (LICRAT) is part of the State of Oklahoma's voluntary buyout. After receiving many
comments like this from the affected community, from the Quapaw Tribe of Oklahoma (the "Tribe") and
from the Oklahoma Department of Environmental Quality (ODEQ), and after the passage of WRD A 2007,
EPA reevaluated relocation. As a result, the selected remedy for OU4 was modified to include relocation.
Thus, any remaining properties in the target area—generally Picher, Cardin and Hockerville, not addressed
under the State buyout program will be addressed under EPA's selected remedy. The relocation will follow
the procedures and priorities established by LICRAT. It will also be administered by the LICRAT.
Comment 5 and Response: Junior and high school students, including the students of Miami High
School, submitted the comments in the following enumerated paragraphs. EPA's responses follow each
comment:
1) Some students voiced opposition to chat sales;
Regarding the safety of chat sales, please see EPA's response to Comment 1 above in this section
of the ROD (Section 23.1(Summary and Response to Local Community Concerns)).
2) Some students were concerned about what is being planned for abandoned mine shafts;
EPA does not address abandoned mine shaft safety hazards other than those associated with
contamination. EPA has entered into a memorandum of understanding with several other Federal agencies,
including some that have the authority and resources to address open mine portals. EPA transmits
information that it has regarding physical safety hazards associated with mine portals to these other Federal
agencies. These agencies include: the U.S. Army Corps of Engineers and the Department of the Interior.
3) Some students said they were concerned that the project would take too long;
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EPA has structured the remediation of OU4 so that the most pressing environmental and human
health hazards are addressed fairly quickly. In particular, once the remedial action begins, remaining target
residents in Picher, Cardin, and Hokcerville should be relocated within three years. Simultaneously, Phase
1 activities, which are intended to address pressing problems, such as in-stream source material and fine
tailings deposits, will also take place in the near term. (For more about Phase 1, please see ROD Section
19.2.4 (Phase 1 Elements).) With residents out of the higher risk areas, it is reasonable to allow the chat, a
valuable commodity, to be sold at the pace that the market can handle.
4) Some students had questions as to whether there will be funding available to complete the project;
As part of its Enforcement First policy, EPA intends to seek funding from potentially responsible
parties (PRPs) who may be liable for EPA's costs under the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA), also called Superfund. Costs that the PRPs do not cover must
come from EPA appropriations. When EPA pays for the cost of remediation at a Superfund site in
Oklahoma, the State provides 10% of the funds.
5) Some students suggested that the mine drainage should be stopped from impacting water quality;
OU4 generally is not intended to address surface water. However, the excavation of in-stream
source material and the erosion control measures that will be taken to address near-stream source material
should eliminate principal sources of surface water and sediment contamination in Tar Creek and other Site
streams. Mine drainage is not part of OU4.
6) One student suggested that the project should be stopped after the buyout of residents is complete.
While relocation of nearby residents will help eliminate the human exposure to source materials, it
will not eliminate the human health risk. In addition, the source material poses a risk to Site biota that must
be addressed.
Comment 6: The Seneca-Cayuga Tribe of Oklahoma requests that the EPA utilize a native seed
mixture to apply to all remediated soils as ground cover, instead of a general vegetative cover as suggested.
Response: EPA will work with all the area Tribes and the Oklahoma Department of Environmental
Quality (ODEQ) during the remedial design phase to develop revegetation plans. Native grasses will be
considered as part of the design. As reflected in the ROD, the soils will be rebuilt naturally to sustain
vegetation using standard land preparation practices such as ripping, contouring, adding amendments,
disking, fertilizing, planting and seeding. Excavated areas will not be backfilled with a soil cover. Where a
cover is used to cap source material, it will meet the substantive requirements of the ODEQ regulations at
OAC 252:515-19-53(a) or an equivalent alternative as determined by EPA consistent with OAC 252:515-
19-53(c). The requirements of OAC 252:515-19-53(a) include a barrier layer that is at least 24 inches of
earthen material.
Comment 7: Don't spend any more money on the remedy or remove chat until all residents are gone.
Response: As part of Phase I of EPA's remedy for OU4, EPA will provide funds to LICRAT,
through ODEQ, to relocate any remaining residents and businesses not addressed under the State buyout
program. Concurrently, EPA will excavate chat and chat bases in remote areas (i.e., distal areas that are not
near populated areas) down to native soil. Excavated chat will be transported to an on-site processor and
released to that processor, or it will be disposed in on-site repositories. These activities will contribute to
the protection of human health and the environment and will produce land that can be used without
restriction.
Comment 8: One commenter pointed out that the EPA issued a new rule on chat that was released
June 6, 2007. The commenter went on to say that, in the commenter's view, moving the chat from the Tar
Creek area is in violation of the EPA rules. The commenter also said that anybody involved in the moving
the chat should be considered generators and help pay for the removal of the hazardous waste. Another
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commenter asked "How does the proposed plan address environmental liability for chat haulers who take
chat beyond the boundaries of the site."
Response: Removing or hauling chat from the Site for off-site use is not a violation of the Chat
Rule, and it is consistent with the ROD. Moreover, a person who removed chat from the Site and who
subsequently used the chat properly as described in the ROD and the Chat Rule would not be liable (as a
generator or otherwise) under CERCLA because, if properly used, the chat would not have been released to
the environment.
To ensure that Site chat sales continue and that chat is used in a fashion that is protective of human health
and the environment, all Site chat will be managed according to the criteria provided in the Chat Rule, 40
CFR Part 278, and its preamble. This means that we are including both the regulations that apply to
transportation construction projects and the preamble guidance that applies to non-transportation, non-
residential projects as requirements under the selected remedy. In addition, only the uses described in the
preamble (including EPA's June 2007 fact sheet; EPA530-F-07-016B) and the transportation construction
project uses described in 40 CFR Part 278 will be allowed for Site chat, as described in the ROD.
In addition, the ROD makes it clear that chat that is taken off-site, must be sent only to a facility that is
acceptable under the Off-site Rule (40 CFR §300.440). EPA is the agency that determines whether a
facility is acceptable for the receipt of CERCLA waste from a Superfund Site. Therefore, EPA will make
acceptability determinations regarding facilities that receive chat from the Site.
EPA is selecting the Chat sales program as outlined as part of the remedy for the Tar Creek Superfund Site.
Because chat sales are part of the remedy, EPA will facilitate activities to support chat sales that will
include the following:
a) The EPA will work with the DOI to facilitate sales of Indian-owned chat.
b) EPA will present a workshop to assist chat/land owners and sellers with chat sales.
c) EPA will provide sample chat sale agreements and site operating plans to chat/land owners and
chat processors.
d) EPA will answer questions about the Chat Rule.
e) EPA will provide technical review to any requests for chat use other than chat mixed in asphalt for
federal transportation projects.
f) EPA will conduct a risk assessment on chat materials that exceed the SPLP and proposed for use
in concrete as specified in the Chat Rule to support the ultimate sale of the chat.
g) EPA will coordinate with DOJ regarding liability protection for chat/land owners.
Please see ROD Section 19.2.2 (Chat Sales and Environmentally Acceptable Chat Use) for more
information.
Comment 9: I do not understand why nearly 8 hours before the meeting it was announced to and by
the media that a thirty (30) day extension was made by EPA Region 6 for the OU4 official public comment
period. What impact will the extension have on EPA plans for OU4.
Response: No. In accordance with and as part of its public participation responsibilities under
CERCLA, a 30 day comment period is provided to allow the public to review and provide comments on
EPA's Proposed Plan and the supporting documents contained in the Administrative Record File. If a
request for an extension is received prior to the conclusion of the comment period, EPA may provide an
additional 30 days to receive any additional comments. The comment period was scheduled to conclude
August 30, 2007. A request was received, and EPA informed the public at the public meeting held on
August 28, 2007 that the comment period would be extended until October 1, 2007. A notice of the
extension was also published in the local newspaper on August 30, 2007. Public comments are one of 9
criteria that assist EPA in its selection of the remedy for a Superfund site or for an operable unit of a
Superfund site.
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Comment 10: Under the proposed plan (4), flotation ponds and fine source material will be capped and
vegetated. Our concern is where these repositories will be fenced and posted, or otherwise made obvious to
the public that these areas are off limits.
Response: As explained in ROD Section 19.2.6 (Other Planned Actions Common to Both Phases),
to help eliminate the possibility of potential exposure to Site source materials, community education and
awareness activities will be conducted throughout the duration of the remedial actions. These activities
will include, but not be limited to, the following:
- Outdoor billboards located near chat piles that have been used in the past for recreation, warning of the
dangers associated with playing on chat piles.
- Biannual notices in utility bills warning of the dangers of chat use in residential areas, and warning people
to stay off of chat piles.
- In-school programs to warn children to stay off of chat piles.
- Outreach to community churches, and social groups.
In addition, the selected remedy requires Institutional Control (ICs) to aid in the management of the wastes
left on-site and to ensure that only appropriate reuse options are implemented. ICs that will be used include
deed notices placed on land parcels that are contained in the Site. ICs would notify current and potential
future deed holders of the presence of wastes left on-site. The deed notices would identify the reason for the
notice, the affected property, the remedy, engineering controls, and land and ground water use restrictions.
ICs will also create an easement granted to ODEQ for continued remedial response. The deed notices
would be filed by the ODEQ should the property owner decline. If DOI is the trustee for the property
where wastes are covered and left in place, then ICs will be developed in coordination with DOI. No
fencing or posting is contemplated under the remedy.
Comment 11: Under the Operation and Maintenance stage, will the repositories be mowed periodically
in order to reduce the growth of woody plants with roots that could compromise the sodded liners and
thereby become an attractive nuisance for wildlife?
Response: Generally EPA's repositories in like circumstances are mowed to prevent the type of root
intrusion that the commenter describes, but this will be decided in Remedial Design. Selection of the
repository location will consider proximity to existing source material locations, thickness of underlying
soil deposits, soil type, depth to ground water, and presence or proximity of floodplains or other surface
water features. Components of the on-site repository and the criteria for maintaining the repository will be
developed during the Remedial Design.
Comment 12: How can you insure that deep tilling of soils contaminated with smelter waste and
transition zone soils will not become an attractive nuisance to wildlife?
Response: The soil remediation goals established for OU4, will address ecological risks at the site.
Soils contaminated above the remediation goals will be excavated and removed. Deep tilling is expected
to further reduce the chemical concentrations in the soil. Deep tilling of soils, particularly compacted soils
that may underlie source material removal areas, will increase infiltration and prevent runoff, and the
aeration that occurs will be beneficial to vegetation establishment. This method is expected to meet the
Remedial Action Objectives and remediation goals for soil; therefore, institutional controls and long-term
operation and maintenance are not expected.
Comment 13: EPA ignored information about subsidence risk (USACE "Picher Mining Field Northeast
Oklahoma Subsidence Risk Evaluation") in developing the Preferred Alternative for OU4.
Response: The referenced USACE study is part of the Administrative Record for the ROD. The
study was carefully reviewed by EPA as it developed the selected remedy to ensure that subsidence would
not interfere with our selected remedy. Generally speaking, however, subsidence considerations will play
more of a role during Remedial Design (RD). For example, when EPA is deciding where to place
repositories as part of RD, subsidence risks will be a factor. EPA and other Federal agencies involved at
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the Site work together within their respective authorities, and share information. In fact, a Memorandum of
Understanding (MOU) was signed in May 2003 between the EPA, the Department of Interior, and the U.S.
Army Corps of Engineers. The purpose of this Memorandum is to facilitate a coordinated response to
environmental contamination, physical safety concerns (open mine shafts, subsidence, and flooding), and
poor economic conditions at the Tar Creek area. To deal with the overlapping authorities and jurisdictions
that exist, the MOU helps coordinate efforts and promotes the exchange and sharing of information among
these agencies. Other participants in this effort include the U.S. Fish & Wildlife Service, the U.S. Geologic
Survey, the U.S. Bureau of Indian Affairs, and the Tribes.
Comment 14: EPA should reconsider it plans for OU 4. With the people removed, the entire project can
be reevaluated. We would suggest that the list of priorities should start with public safety and health, and
subsequent buyout, should be refocused to limit environmental damage to the watershed. In this setting,
there would be no pressure to push chat sales past economic realities, and the process of chat removal and
the permanent storage of fines can be explored at a safe, rational and commercially viable pace.
Response: EPA reexamined the preferred alternative based on public comments and the provisions
provided by WRDA for voluntary relocation. The preferred alternative was modified to include voluntary
relocation and an extended timeframe for chat sales to continue an additional 10 years, for a total of 30
years. With these and other modifications to the plan, the concerns identified above will be addressed.
Comment 15: EPA's proposed plan does not have state support, and will not have state support until it
includes a residential buyout.
Response: Based on State, Tribal and community concerns with the Preferred Alternative and in
view of the passage of WRDA which allows EPA to undertake relocation without applying the Uniform
Relocation Act (URA), EPA has incorporated voluntary relocation as part of the remedy and the State of
Oklahoma, acting through the Oklahoma Department of Environmental Quality (ODEQ), now concurs with
the selected remedy.
Comment 16: Exempt chat that falls under a 400 parts per million lead standard from requirements
described in the proposed plan.
Response: In deciding what uses of Site chat would be acceptable (see ROD Section 19.2.2
(Environmentally Acceptable Uses of Chat)), EPA looked to uses identified in the Chat Rule and its
preamble because those uses were found to be safe, based on the extensive scientific study that is
documented in the preamble to the Proposed Chat Rule (71 Fed. Reg. 16729 (April 4, 2006)) and in the
preamble to the Final Chat Rule (72 Fed. Reg. 16729 (April 4, 2007). While chat that contains lead at
concentrations of less than 400 parts per million does not exceed EPA's remediation goals for the Site, that
does not mean that use of such chat is risk free. Lead is a dangerous hazardous substance, and exposure to
lead should be avoided. See "Preventing Lead Poisoning in Young Children, A Statement by the Centers
for Disease Control" (October, 1991). Under the selected remedy, only those uses of Site chat identified in
the ROD are allowed because those are the uses that EPA has determined to be safe.
Comment 17: Would buyers of chat be required to sign a waiver releasing seller from liability?
Response: No waiver will be required. However, the record keeping requirements found in the Chat
Rule will apply (see ROD Section 19.2.2 (Environmentally Acceptable Uses of Chat)). The Chat Rule can
be found in the July 18, 2007, edition of the Federal Register at pages 39331 to 39353 or at this website:
http://www.epa.gov/fedrgstr/EPA-WASTE/2007/Julv/Dav-18/fl3544.htm
EPA plans to conduct multiple workshops, and provide fact sheets to explain the ROD requirements for the
use of Site chat.
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Comment 18: What alternative water supply will be provided for contaminated rural residential wells?
With the buy out taking place, it has been stated, that once it (buy out) is complete, all public services
(electric, water, etc.) will be shut off to the Tar Creek Area.
Response: Under the ROD, an alternative water supply will be provided to 0U4 residences using
private wells for drinking water where drawn well water concentrations exceed the National Primary
Drinking Water Standard of 0.015 milligrams per liter (mg/L) for lead. Two private wells were identified
as exceeding the standard. Due to the uncertainty as to what sort of water supply systems will remain after
relocation of target residents is complete, the method for supplying the water will be determined during the
Remedial Design stage of the remedy. If, as part of the remedial action, eligible households are connected
to existing municipal or rural water supplies, the owner/residents of these households would be responsible
for payment of continued water service and for household water system repairs. That is, the remedial
action will provide the connection to the alternative water supply to eligible households, but it will not pay
for water service or for household plumbing repairs or for system repairs.
Comment 19: What good will it do to remediate yards after the relocation program is complete? There
will still be source materials and contamination in the area, so any yards left to remediate will eventually
become contaminated again.
Response: Residents in rural areas that elect not to participate in the State of Oklahoma's relocation
program, whose residential yards are found to have concentrations of soil lead that exceed 500 ppm will be
remediated by EPA. As described in the ROD, EPA intends to address the source materials (i.e., the chat,
the fine tailings, and the smelter waste). Once the source material is removed, areas that were once
uninhabitable will provide a healthier environment and the productive use of land. EPA is unaware of any
sources, other than anthropogenic activities (e.g.,use of chat as fill in a previously uncontaminated area,
installation of a chat driveway in an uncontaminated area), that would recontaminate a remediated
residential yard. Present day air deposition of lead-contaminated dust, for example, has been monitored
and found to be insignificant.
Comment 20: The Wyandotte Nation supports the use of institutional controls and operation and
maintenance activities, however, as needed is not an acceptable time frame. How often and for how many
years to come will these institutional controls take place, and who will oversee them?
Response: Though the types of institutional controls that are needed at this site are identified in the
OU4 ROD, establishing these controls in an effective manner will require the collective efforts and
feedback of our Federal, State, Tribal and local county representatives. The specifics involving duration
and the parties that will be responsible for monitoring these controls will be better determined during the
Remedial Design. EPA intends to work with its counterparts to ensure the items that have been identified
in the comment are fully addressed. The five-year review process will also evaluate the effectiveness of
institutional controls.
Comment 21: What about the ground water contamination that will still exist?
Response: Studies to date at the Site have not found any significant contamination of the Roubidoux
Aquifer, the principal drinking water aquifer in the area. The mines were excavated in the shallower Boone
Aquifer. The Boone is contaminated with metals at concentration levels that exceed MCLs; accordingly, it
is not fit to drink. As part of the selected remedy, EPA will provide alternative drinking water supplies to
residents using wells that draw from the Boone or other contaminated ground water as provided in the OU4
ROD. In an EPA action that is separate from the OU4 response action, EPA is conducting a hydrogeologic
study of the ground water. Next steps will be determined once this study is complete. EPA estimates that
the study will be completed in 3 years.
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23.2 Summary and Response to Specific Legal and Technical Questions
Comment 1: The Tribe suggests that the EPA should be consistent at the Tar Creek site with the
Cherokee County, KS site on their clean up levels for lead (use 400 mg/kg, as opposed to 500 mg/kg). The
sites are contiguous and cleanup should have the same remediation goals.
Response: In developing its remediation goals for OU4, EPA Region 6 considered the Ecological
Remediation Goals developed for Cherokee County, Kansas by Region 7. The Region 7 analysis
recommended a range of values for lead in soil that would be protective for exposed terrestrial wildlife. The
Region 7 recommended soil remediation goals for lead ranged between 377 and 1,175 milligrams per
kilogram (mg/kg). EPA Region 7 used these remediation goal ranges when it selected the remediation goals
for the Cherokee County, Kansas, Site in the Amended Record of Decision dated September 29, 2006.
Based on the similarity of the ecologies in the two areas (Region 7 Draft Ecological Preliminary
Remediation Goals, Cherokee county Superfund Site (July 14, 2006) Memorandum from Jon Rauscher,
May 24, 2007), it is appropriate to use the same ranges for OU4 remediation goals. The remediation goal
for lead at Tar Creek is 500 mg/kg because that is within the range recommended in the Region 7 report,
and because EPA Region 6's Baseline Human Health Risk Assessment for Operable Unit 2 (Residential
Areas), based on the Integrated Exposure Uptake Biokinetic Model (IEUBK), found that 500 mg/kg was
protective of human health. In short, based on the Region 7 report, 500 mg/kg is protective of the
environment and based on the Region 6 study, it is also protective of human health.
Comment 2: The Tribe would request the preferred alternative adapt the portion of Alternative 8 that
addresses completely removing in/near stream waste and integrating it into existing upland chat deposits as
an early response. The Tribe feels the complete removal of the in/near stream chat is more beneficial
overall, and in the future, for the recovery of our injured natural resources.
Response: The selected remedy addresses all near-stream source materials and in-stream source
materials; although, there are different timeframes for the completion of the remedial actions associated
with each. Early Phase 1 actions will be implemented for in-stream source materials. As an interim
measure, sheet piling, berms, constructed wetlands, or other engineering controls will be installed to control
near-stream source materials in order to help prevent contamination from migrating to surface water. Final
disposition of the near stream source materials will be addressed under Phase 2 actions that are consistent
with ongoing chat processing at these locations.
Comment 3: The Tribe requests a monitoring plan be developed and implemented for all on-site
repositories or chat injection sites to insure that surface and ground water contamination is not continuing.
Response: EPA agrees. Though EPA will not commence full-scale injection until the hydrogeologic
study is complete, a monitoring plan will be included for any injection and a monitoring plan will be
included in the Operations and Maintenance Plan for the repositories.
Comment 4: The proposed plan (4) relies on commercial means as the primary removal mechanism
for the chat piles. How can you guarantee that chat used in asphalt and as a road base will not be used in
residential areas? Will the EPA regulate chat sales, hauling, and use in the same manner as the Department
of the Interior (DOI)? Further, how will the repair of roads that are chat based and covered with
chat/asphalt mix be managed in order to protect human health and the environment? Of special interest is
whether or not asphalt (chipped crumbled) during reconstruction will be made available to the public for
private use or will it be totally recycled into new road covering? How will road base be contained during
reconstruction in order to protect human health and the environment?
Response: Chat, which makes excellent gravel, is one of those materials. In order to avoid releases
of untreated chat into the environment, EPA will ensure, as part of its responsibilities under the Off-site
Rule, that facilities (e.g., asphalt mixing plants, glass factories) where chat is taken are determined to be
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acceptable under the Off-site Rule, 40 CFR § 300.440. Moreover, as explained in ROD Section 19.2.2
(Chat Sales and Environmentally Acceptable Chat Use), only certain uses of Site chat will be allowed. To
help ensure that only these uses take place, EPA's ROD requires that acquirers of chat complete the
paperwork requirements of the Chat Rule for all Site chat use, and that copies of the required submissions
be sent to EPA's Remedial Project Manager (RPM) for OU4. EPA will conduct on-site seminars to explain
these requirements. As with any hazardous substance, if it is released to the environment, the responsible
parties may face CERCLA liability, and the risk of such liability should help ensure responsible behavior.
Comment 5: Selling chat will serve only to spread contamination and is neither economically feasible,
nor can this portion of the remedy be completed in 20 years.
Response: Please see EPA's response to the first comment in Section 23.1 (Summary and Response
to Local Community Concerns).
Comment 6 (a): The Department of the Interior (DOI) remains concerned that issues such as the exercise
of EPA's CERCLA authority to explicitly authorize chat sales as a fundamental component of the final
remedy has yet to be addressed by the Proposed Plan.
Comment 6(b): Chat sales are appreciated along with the anticipated potential removal of as much as
95% of contaminants from the site, as incorporated into discussion of the remedy. The plan does not
however specify which agency will provide legal oversight over the chat sales, and the Plan could be
interpreted to only encourage chat sales, rather than explicitly authorize them as a CERCLA remedy.
Response: Chat sales are part of the CERCLA remedy. See ROD Section 19.2.2 (Chat Sales and
Environmentally Acceptable Chat Use). As part of the selected remedy for Tar Creek Superfund Site
Operable Unit 4 (OU4), EPA will facilitate activities to support chat sales that will include the following:
a) EPA will work with the DOI to facilitate sales of Indian-owned chat.
b) EPA will present a workshop to assist chat/land owners and sellers with chat sales.
c) EPA will provide sample chat sale agreements and site operating plans to chat/land owners and
chat processors.
d) EPA will answer questions about the Chat Rule.
e) EPA will provide technical review to any requests for chat use other than chat mixed in asphalt for
federal transportation projects.
f) EPA will conduct a risk assessment on chat materials that exceed the SPLP and proposed for use
in concrete as specified in the Chat Rule to support the ultimate sale of the chat.
g) EPA will coordinate with DOJ regarding liability protection for chat/land owners.
In addition, EPA has expanded the provisions of the Chat Rule to cover all Site chat use. See ROD Section
19.2.2 (Environmentally Acceptable Chat Use). By expanding the provisions of the Chat Rule to cover the
use of Site chat, EPA is helping to ensure that chat is used in an environmentally acceptable manner.
Finally, EPA itself will make sure that all off-site facilities receiving Site chat are acceptable within the
meaning of the Off-site Rule, 40 CFR § 300.440.
Comment 7: The Proposed Plan discusses the total present value of the life of any alternative to be
chosen as the final remedy which, as we have provided previous documentation to you, for exceeds DOI
budgeting as a part of our trust responsibility for these chat sales.
Response: Under the NCP, cost can only be considered in selecting a remedy from among protective
alternatives. The remedy selection process requires that alternatives must be demonstrated to be protective
and ARAR-compliant (or justify a waiver) in order to be eligible for consideration in the balancing process
by which the remedy is selected. This sequence of steps ensures that the selected remedy will be protective
of human health and the environment. Cost is a relevant factor for consideration as part of the selection of
the remedy from among protective, ARAR-compliant alternatives. As explained in ROD Section 20.3
(Cost Effectiveness), the selected remedy is cost effective. It is also the least expensive of the protective
remedies, measuring present value.
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Comment 8: It is recommended the following language be substituted for the Paragraph beginning at
the bottom of Page 1: The EPA agrees with the local community, the State, the Tribe, and the DOI that
such sales should continue as an authorized and integral part of any proposed remedy (except the no further
action alternative). To ensure that chat is used in an environmentally acceptable fashion, the EPA proposes
to require that all Site chat that is sold and used must be managed according to the criteria provided in the
Chat Rule, 40 C.F.R. Part 278 and the preamble thereto. The EPA further agrees with the aforementioned
interested parties that in order to achieve the maximum environmental benefit from chat sales, the EPA
proposes to authorize and oversee all chat sales at OU4 as a CERCLA remedy, and require and ensure that
all such sales comply with all applicable environmental requirements (including , but not limited to, the
Chat Rule). The EPA proposes to work with the State of Oklahoma, the Quapaw Tribe, and the
Department of the Interior to identify and incorporate in the Final Plan any applicable environmental
standards that should apply to all chat sales at OU4. Further, the EPA proposes to coordinate with its
governmental partners such tasks as necessary to encourage and enable the adoption of the Chat Sale Pilot
Project into the remedy for the site.
Response: The concepts discussed in the Proposed Plan paragraph that you have referenced are
generally incorporated into ROD Section 19.2.2 (Environmentally Acceptable Chat Use). The ROD does
expand the provisions of the Chat Rule to cover the use of Site chat. See id. Provisions regarding
coordination with the U.S. Department of the Interior, the commenter, are incorporated into the following
parts of the ROD: 16.2.6 (Institutional Controls); Section 19.2.2 (Environmentally Acceptable Uses of
Chat); 19.2.6 (Other Planned Actions Common to Both Phases); and 19.4.1 (Available Uses of Land).
EPA's intention to encourage Best Management Practices is also discussed at ROD Section 19.2.2
(Environmentally Acceptable Uses of Chat).
Comment 9: The map and discussion of "distal areas" is unclear and should be clarified.
Response: The distal areas are remote areas with generally sparse source chat deposits located away
from the central mining areas that have the largest chat piles. Clearing the distal areas of chat as part of
Phase 1 of the selected remedy is intended to rapidly establish a significant reduction in the footprint of
source materials on the Site in order to leave less land with future use restrictions and long-term operation
and maintenance requirements. The figures (i.e., illustrations) included in the ROD represent the areas
defined as distal areas. The distal areas were established based upon local watersheds. The intention is
that, by removing source material in each of those watersheds, there should be a commensurate
improvement in water quality. As part of a more detailed analysis for the Feasibility Study and to develop
refined cost estimates, the distal areas (and the source materials present) were divided into a Northeast,
Southeast, and the Elm Creek Distal Zones. The map that depicts distal areas in the Proposed Plan was
somewhat modified in the OU4 ROD, as was the discussion of the distal areas.
Comment 10: The plan does not specify which agency will be certifying Off-Site Rule compliance.
The Department of Interior continues to maintain that the EPA is the appropriate agency for such
compliance certification.
Response: The ROD makes it clear that chat that is taken off-site, must be sent only to a facility that
is acceptable under the Off-site Rule (40 CFR §300.440). EPA is the agency that determines whether a
facility is acceptable for the receipt of CERCLA waste from a Superfund Site. Therefore, EPA will make
acceptability determinations regarding facilities that receive chat from the Site.
Comment 11: In all the Alternatives, the proposed time frames for chat sales are too compressed and
appear to be internally contradictory.
Response: As reflected in the Record of Decision for OU4, the timeframe for chat sales has been
modified. Since residents facing the greatest risk of exposure will now be relocated, the EPA has extended
the timeframe for chat sales an additional 10 years, from 20 years, to 30 years. Additional information on
this modification is in ROD Section 4.0 (Description of the Selected Remedy).
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Comment 12: It is unclear from the Plan what process will be utilized to determine chat pile
commercial viability.
Response: As part of future five-year reviews, EPA will evaluate the progress of chat sales. Chat piles and
bases remaining after 10 years will be evaluated for commercial viability. This determination will be made
using input from the chat/land owners, appropriate Tribal representatives, and the commercial operators.
See ROD Section 19.2.2 (Environmentally Acceptable Chat Use).
Comment 13: On page 4 of the draft Plan, the proposed Notice provides for the EPA to have
determined that a particular chat pile poses "a significant risk to public health and safety." However, Page
11 of the Plan it states that "exposure through the ambient air inhalation route of intake poses no health
risk." It is unclear how the EPA could make a determination that a pile poses "a significant risk to public
health and safety" in light of the statement on Page 11.
Response: On page 11 in the same paragraph where it states that risk through the inhalation route
presents a minimal risk, it also says that the primary human exposure at OU4 occurs through incidental
ingestion associated with normal hand to mouth contact after contact with source materials. Surface layers
of piles that are left undisturbed become crusted and hinder dust from being emitted through the air.
However, when a chat pile is disturbed by people walking or playing on the pile surface, the contaminants
become available through the dermal, inhalation and ingestion routes of intake. The risk assessment
evaluated the risk from exposure to contaminants in the piles by adolescents or young children who play on
these piles. Such activities by young children or adolescents presented a significant risk through the
incidental ingestion route of intake that could not be ignored. The EPA has documented recreational
activities on chat piles undertaken by adolescents and young children in photographs and digital recordings
that are part of the OU4 Administrative Record.
Comment 14: Air Monitoring: If exposure through the ambient air inhalation route of intake poses no
health risk, it is unclear why and whether air monitoring of chat sales and removal operations is necessary.
If air monitoring is not necessary, it is unclear whether the listed expenditures for environmental
monitoring (which is presumed to be based upon the St. Joe pilot Project Model) are necessary.
Response: Air monitoring is a Best Management Practice (BMP) component of the remedy that will
be performed as needed, as determined by EPA, during chat processing. The intent is to confirm air quality
and the effectiveness of the dust mitigation measures. BMPs are broadly defined by EPA under Section
304 of the Clean Water Act (including its implementing regulations at 40 CFR § 122.44(k)) as schedules of
activities, prohibitions of practices, maintenance procedures, and other management practices to prevent or
reduce the pollution of water of the U.S. BMPs include treatment requirements, operating procedures, and
practices to control industrial site runoff, spillage or leaks, or drainage from raw material storage piles,
erosion controls, dust suppression methods, or air monitoring.
Comment 15: The plan does not specify which agency will be enforcing the State of Oklahoma's
ARARs, and which agency will be spending or receiving $12,500,000 for Off-Site Rule Acceptability
Determinations.
Response: The combined efforts of EPA, ODEQ, and the Oklahoma Water Resources Board will be
used to ensure that certain components of the remedy comply with the identified Federal and State ARARs,
listed in Table 13 of the ROD. With respect to the Off-site Rule Acceptability Determinations, please see
the response to Comment 10 above in this section.
Comment 16: It is unclear what the Quapaw Tribe and the Oklahoma Department of Environmental
Quality will be tasked to perform in exchange for their respective receipt of over $1,000,000.
Response: The cost estimate is for Management Assistance for the Quapaw Tribe and the Oklahoma
Department of Environmental Quality to compliment EPA's effort in overseeing the remedy for 25 years.
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Comment 17: How does EPA feel that deep tilling will solve the problem of contamination levels in
soils? It is our concern that deep tilling will only cover up the contamination for a period of time, but,
eventually, the contamination will work its way to the top, and we will be subject to the age old
contamination problem.
Response: Deep tilling is prescribed in all action alternatives to address transistion zone soils,
smelter-affected soils, and soils underlying source materials once the source materials have been excavated
and removed. Deep tilling of soils following source material excavation is expected to meet the Remedial
Action Objectives (RAOs) and remediation goals for soil and has proven effective in reducing Chemical of
Concern (COC) concentrations below risk-based levels in some chat bases with minimal contamination and
in transition-zone soils at other Tri-State Mining Sites. In addition, deep tilling of soils, particularly
compacted soils that may underlie source material removal areas, is an effective method of increasing
infiltration and preventing runoff, in addition it improves aeration which is beneficial to vegetation
establishment.
Comment 18: High concentrations of lead are addressed under the preferred remedy identified in this
"Proposed Plan; however, the concentrations of lead are not so high as to be several orders of magnitude
above levels that allow for unrestricted use and unlimited exposure. Therefore, the lead is not considered to
be a principal threat under the NCP consequently, there is no expectation under the NCP that the lead be
treated. This comment is very conflicting and makes no sense. If you don't have to address the lead under
the NCP, why are you addressing it?
Response: The operative word in the cited Proposed Plan passage is "treated." Since the lead is not
a principal threat waste, there is no expectation that it be treated. Although lead at this Site is not
considered a principal threat waste under National Contingency Plan (NCP), high concentrations of lead
found in OU4 are a threat to Human Health and the Environment. The EPA conducted a Baseline Human
Health Risk Assessment and an Ecological Risk Assessment for the same ecological zone. Based on these
studies, it was determined that there is sufficient risk to human health and to the environment from releases
of lead, cadmium, and zinc that the selected remedy is necessary to protect public health or welfare and the
environment from actual or threatened releases of hazardous substances into the environment.
Comment 19: It would make sense for the clean up levels at Tar Creek to be consistent with the clean
up levels at Cherokee County, Kansas of Clean up level of 400 mg/kg.
Response: See response to Comment 1 in this section.
Comment 20: How can you attain zero discharge in cadmium, lead and zinc from source materials to
surface waters?
Response: The EPA defines zero discharge as discharge concentration levels that would be
consistent with the concentration levels that would be expected from soil that has background
concentrations of these chemicals. The primary goal is to eliminate discharge of these metals by preventing
direct runoff and seepage from the source materials into surface water bodies found within the site. This
may mean physically moving the material away from the surface water body or deploying other
engineering controls (e.g., sheet pilings, berms and constructed wetlands) to prevent the discharge from
reaching the surface water body.
Comment 21: What alternative water sources? EPA continuously refers to an alternative water source,
how can your refer to it if you don't know where the water source will come from. Also, it has been stated
several times, that once the Buyout is complete, all public services will cut off from the Tar Creek area and
residents who remain. Also, please take into consideration the Ozark Cavefish, it is on the endangered
species list and is an aquatic receptor. Due to the karst topography within Ottawa County, contamination to
ground water could likely affect this endangered species.
Response: Due to the uncertainty as to the type of water supply systems that will remain after
completion of the State's relocation, the method for supplying the water will be determined during the
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Remedial Design. However, the alternative methods may include importing bottled water, providing for
home treatment systems, etc.
EPA acknowledges the potential presence of the Ozark Cavefish. The actions taken as part of the OU4
remedy will result in the removal of source material from the site and would be expected to improve any
potential habitats. Source material will be eliminated from the distal areas of the site in Phase 1 which will
remove sources of contamination from approximately 80% of the site. Based on available information, the
Ozark cavefish is not found within the Site, however, as part of this ROD, EPA will conduct a
hydrogeological study that could be used to evaluate specific locations where habitat may exist outside the
boundaries of the site. EPA will coordinate with the Fish and Wildlife Service to ensure that any concerns
about impacts to critical habitats are addressed.
Comment 22: The Proposed Plan does not clearly address how decisions will be made about what is to
be done, how it will be done or what the cleanup standards will be. What remediation activities will be
used to ensure the proper clean up procedures? The Proposed Plan does not clearly address how the
cleanup process will be conducted.
Response: Cleanup standards (i.e., remedial action objectives and remediation goals) are identified
in Section 15.1 of the ROD (Remedial Action Objectives for the Site) and are the same as those presented
in the Proposed Plan. The approach to the remedy is discussed in this ROD and primarily consists of
implementing different phases of the remedy over time. Each phase has distinct remedial elements and
approaches that are outlined and discussed in detail. As cleanups are completed over time, confirmation
sampling will be completed to verify that the remedy achieved remediation goals and remedial action
objectives.
Comment 23: What is the priority basis that will be used to clean up source material in Tar, Lytle, Elm
or Beaver Creeks?
Response: During Remedial Design, a priority system will be developed for all remedial actions and
is defined to some degree by the phasing of the remedial elements as discussed in this ROD. Actions to
address source materials in Site surface water systems are included in the early actions completed at the
Site. Priorities among streams will probably be driven by those actions that can accomplish the greatest
amount of risk reduction and overall environmental improvement in the least amount of time at a
reasonable cost with the long-term permanent protection for the stream section in question. Of these in-
stream actions, action in Tar Creek may be completed last because, until source materials in the Tar Creek
watershed (but outside of the stream) are addressed, the watershed source materials will contribute to in-
stream contamination. So it makes sense to address in-stream contamination last. In contrast, in other Site
streams where there are no source materials in the watershed that could contribute to the recontamination of
the stream, in-stream source materials may be addressed quickly and those in-stream materials will be
given a higher priority than those in Tar Creek. Nonetheless, the in-stream contamination in Tar Creek will
be addressed as part of Phase 1.
Comment 24: What is the method for stream remediation? Is it based on visual observation of source
materials, sampling concentrations, or stream locations?
Response: Areas requiring source material to be excavated from streams will be based upon visual
observation of source materials within the stream bed. However, following excavation, a sampling and
analysis program will be implemented to verify that the excavated areas meet the remediation goals.
Comment 25: Will chat/source material be pulled out of the stream banks or riparian zones located near
the water bodies? Has a buffer zone for the chat removal from the streams been established? Riparian
zones should be cleaned up as well.
Response: Yes, source material will be excavated from stream beds and banks. Buffer zones have
not been established for the site streams, but areas containing source material near the streams may be
addressed in the interim with engineering controls to prevent recontamination of the streams.
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Comment 26: Will geological studies be conducted to ensure that the repository cells/landfill is not
constructed in a subsidence area? What citing criteria will be used? What type of liner will be used? Will
there be a leachate collection system? Where will leachate and storm water go? Will there be long-term
monitoring of groundwater and surface water?
Response: All necessary precautions will be conducted to ensure that the repositories are not
installed in a subsidence area. On-site repositories will be constructed to accept Site source materials for
final disposal. The repositories will cover an estimated 28 acres and will be capable of receiving an
estimated 1,000,000 yd3 of source materials, affected soils, and other Site-related materials such as wood,
concrete, and miscellaneous debris. The liners for on-site repositories that are not built in areas of
contamination shall meet the substantive requirements of the ODEQ regulations at OAC 252:515-1 l-2(b)
unless an alternative is approved by EPA consistent with OAC 252:515-1 l-2(c). The cover shall meet the
substantive requirements of the ODEQ regulations at OAC 252:515-19-53(a) or an equivalent alternative as
determined by EPA consistent with OAC 252:515-19-53(c). The requirements of OAC 252:515-19-53(a)
include a barrier layer that is at least 24 inches of earthen material. The requirements also include the
installation of an erosion layer above the barrier layer. The erosion layer is to be at least one foot of soil
capable of sustaining plant growth. For cost estimating purposes, a clay liner, filter sand bed, and a soil
cover are assumed although the actual construction will be determined in the Remedial Design. Upon
closure, repositories will be contoured to promote drainage and revegetated.
Comment 27: The Plan needs a provision to allow for the processing of the fine tailings. We believe
zinc and other metals can be extracted economically from this material. This would have a large
economical benefit for this area and be an alternative to injecting this material back into the mines.
Response: Fine tailings will be injected or covered in place. The fine tailings may be consolidated
to reduce the footprint of the final cover. Additional processing could be completed prior to the
implementation of these actions as long as the processing does not compromise the implementation of the
remedy.
Comment 28: The plan says EPA will encourage chat sales. It is impossible to encourage sales by
regulating a product as a "hazardous waste" when in fact it has less than 400 ppm lead (washed chat). If
you truly want to encourage chat sale I would suggest you open up more communication with the
companies that sell chat. Real communication, not just one or two conversations on the subject.
Response: While chat that contains lead at concentrations of less than 400 parts per million does not
exceed EPA's remediation goals for the Site, that does not mean that use of such chat is risk free. Lead is a
dangerous hazardous substance, and exposure to lead should be avoided. See "Preventing Lead Poisoning
in Young Children, A Statement by the Centers for Disease Control" (October, 1991). Under the selected
remedy, only those uses of Site chat identified in the ROD are allowed because those are the uses that EPA
has determined to be safe. Please also see EPA's response to Comment 16 in Section 23.1 (Summary and
Response to Local Community Concerns).
Comment 29: The remedy the Tribe supported was more explicit at aggressively controlling the sources
that contaminate our ground and surface waters, while maximizing future unrestricted use of surficial lands.
Specifically, threats associated with releases from surficial wastes including those associated with
repositories would generally have been eliminated in our proposed remedy. Our experts tell us that a more
aggressive cleanup (to pre-mining conditions) is necessary because our future uses of the land include using
reservation resources as they were used prior to mining - the Quapaw Tribe has never given up its rights to
use our resources as originally intended.
Response: In developing its remediation goals for OU4, EPA Region 6 considered the Ecological
Remediation Goals developed for Cherokee County, Kansas by Region 7. The Region 7 analysis
recommended a range of values for lead in soil that would be protective for exposed terrestrial wildlife.
EPA Region 7 used these remediation goal ranges when it selected the remediation goals for the Cherokee
County, Kansas, Site in the Amended Record of Decision dated September 29, 2006. Based on the
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similarity of the ecologies in the two areas (Region 7 Draft Ecological Preliminary Remediation Goals,
Cherokee county Superfund Site (July 14, 2006) Memorandum from Jon Rauscher, May 24, 2007), it is
appropriate to use the same ranges for OU4 remediation goals. The remediation goal for lead at Tar Creek
is 500 mg/kg because that is within the range recommended in the Region 7 report, and because EPA
Region 6's Baseline Human Health Risk Assessment for Operable Unit 2 (Residential Areas), based on the
Integrated Biokinetic Uptake Model (IEUBK), found that 500 mg/kg was protective of human health.
Moreover, EPA has found that when lead at the site is remediated to 500 mg/kg, the other Site metals are
also remediated to safe levels because the metals are almost invariably found in proportionate
concentrations. In short, based on the Region 7 report, we have selected remediation goals that are
protective of the environment, and, based on the Region 6 study, these goals are also protective of human
health. The selected remedy identified in this ROD should provide protection for the subsistence lifestyle
at the conclusion of the remedy. The removal of source materials, transition zone soils, and soils which
underlie source material above the action levels and the implementation of soil rebuilding and grading will
result in levels of COCs well below the action level and may even achieve background concentrations in
some settings.
Comment 30: The Tribe continues to be concerned about the weight that will be given to various costs
in the ultimate design of the preferred remedy. We are still concerned that a pure cost benefit approach in
evaluating whether or not to cap or remove mill ponds - without considering the other eight criteria of the
NCP - could subvert the intent of the NCP by failing to "take a hard look" at cumulative affects of
addressing mill ponds with a myriad of small subprojects.
Response: EPA does not agree that a pure cost benefit approach was implemented. The EPA
implemented a detailed analysis process with respect to the nine criteria prescribed by the National
Contingency Plan (NCP) (40 CFR Part 300), before a remedy selection decision was made. Under the
NCP, cost can only be considered in selecting a remedy from among protective alternatives. The remedy
selection process requires that alternatives must be demonstrated to be protective and ARAR-compliant (or
justify a waiver) in order to be eligible for consideration in the balancing process by which the remedy is
selected. This sequence of steps ensures that the selected remedy will be protective of human health and the
environment. Cost is a relevant factor for consideration as part of the selection of the remedy from among
protective, ARAR-compliant alternatives.
The detailed analysis of alternatives consists of the analysis and presentation of the relevant information
needed to allow decision-makers to select a site remedy. (It is not the decision-making process itself.)
During the detailed analysis, each alternative is assessed against each of the nine criteria. The analysis lays
out the performance of each alternative in terms of compliance with ARARs, long-term effectiveness and
permanence, reduction of toxicity, mobility or volume through treatment, short-term effectiveness,
implementability, and cost. The assessment of overall protection draws on the assessments conducted under
other evaluation criteria, especially long-term effectiveness and permanence, short-term effectiveness and
compliance with ARARs. State and community acceptance also are assessed, although definitive
assessments of these factors cannot be completed until the public comment period on the draft RI/FS and
proposed plan is completed.
After making the individual criterion assessments for each alternative, the alternatives are compared to each
other. This comparative analysis identifies the key tradeoffs (relative advantages and disadvantages) among
the alternatives with respect to the nine criteria. The purpose of this comparative analysis is to provide
decision-makers with sufficient information to balance the trade-offs associated with the alternatives, select
an appropriate remedy for the site and demonstrate satisfaction of the CERCLA remedy selection
requirements.
Comment 31: It is necessary that the EPA clarify in the Proposed Plan that the CERCLA protections
and incentives currently applied to chat sales will remain in place for the duration of chat sales.
Response: As reflected in the OU4 ROD, EPA will coordinate with the Department of Justice to
provide liability protection for chat/land owners to help allay the concern of some chat owners regarding
potential future liability arising from the sale and transport of chat to off-site locations.
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Comment 32: The EPA should be aware - this is a point the Quapaw Tribe has tried to make to the EPA
on many occasions - that any additional requirements and /or potential liability burden placed on chat
sellers/processors, will severely reduce or eliminate the economic viability of the already marginal market
for chat. The EPA should consider additional aid to restricted Indian chat sellers/processors that would
alleviate these burdens by providing financial incentives to compensate for these burdens, or by transferring
them to others. For example, providing technical assistance for complying with the Chat Rule and the Off-
Site Rule, and providing Human Health Risk Assessment analyses for proposed non-transportation uses for
chat. The EPA should continue to fund the disposal of chat fines that may be produced by chat particle
sizing operations. The EPA should also consider subsidizing the transportation of chat beyond a pre-
defined radius from the Site.
Response: Chat sales are part of the CERCLA remedy. As part of the selected remedy under the
OU4 ROD, EPA will facilitate activities to support chat sales that will include the following:
a) EPA will work with the DOI to facilitate sales of Indian-owned chat.
b) EPA will present a workshop to assist chat/land owners and sellers with chat sales.
c) EPA will provide sample chat sale agreements and site operating plans to chat/land owners and
chat processors.
d) EPA will answer questions about the Chat Rule.
e) EPA will provide technical review to any requests for chat use other than chat mixed in asphalt for
federal transportation projects.
f) EPA will conduct a risk assessment on chat materials that exceed the SPLP and proposed for use
in concrete as specified in the Chat Rule to support the ultimate sale of the chat.
g) EPA will coordinate with DOJ to provide liability protection for chat/land owners.
As a consequence of EPA's selection of chat sales as a part of the remedy for the Tar Creek Superfund Site,
the BIA, with the assistance of other agencies of the DOI, will manage and administer the following (DOI
letter dated September 28, 2007, from Mr. L. Michael Bogert to Regional Administrator Richard E.
Greene):
a) Perform engineering ownership determinations, cadastral surveys, and appraisals, if needed;
b) Outreach and communication with the Indian owners of restricted chat and land regarding chat
sales and surface leasing;
c) Appraisals of the fair market value of restricted chat and surface leases and provision of copies
thereof to the Indian chat owners and land owners;
d) Necessary tasks associated with the review and possible approval of chat sales contracts and
business site leases,
e) Quantitative analysis of chat removed from Indian-owned restricted chat piles for production
verification purposes;
f) Tasks associated with the accounting of funds and distribution of proceeds from the sale of
restricted chat to Indian owners;
g) Logistics associated with competitive or negotiated sales of Indian-owned restricted chat;
h) Assistance, as required in negotiations between Indian owners of restricted chat and potential chat
purchasers;
i) Coordination of sales and other issues with the relevant offices of Federal, State, and Tribal
governments; and
j) Review and enforcement of sellers' compliance with chat sales agreements and volumetric
recording of chat sales.
The requirements for on-site and off-site use of Site chat are explained in ROD Section 19.2.2
(Environmentally Acceptable Chat Use). Lastly, there are no plans by EPA to subsidize the transportation
of chat.
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Comment 33: EPA should incorporate the best management practices established under the Pilot
Project for the Sale of Indian-Owned Chat at ARARs for all chat sales. EPA should incorporate into the
Proposed Plan the requirements developed by the DOI and the EPA in consultation with the State and the
Quapaw Tribe and be made enforceable for the processing and transport of all chat, irrespective of
ownership. Those standards developed as part of the Pilot project for the Sale of Indian Owned Chat are
reasonable and protective of human health and the environment. EPA's enforcement of its own end use
Chat Rule, 40 C.F.R Part 278, and the Off-Site Rule, 40 C.F.R. Part 300.440, is necessary and the
processing and transport of chat prior to end use must also be regulated.
Response: Only cleanup standards, standards of control, or other substantive environmental
protection requirements, criteria, or limitations promulgated under federal or state law can be ARARs, so
the practices established under the Pilot Project do not qualify. Under the ROD, EPA has established
standards for environmentally safe uses of Site chat. These standards can generally be found in ROD
Section 19.2.2 (Environmentally Acceptable Chat Use) and these standards include an expansion of the
provisions of the Chat Rule to cover Site chat use. Section 19.2.2 also explains that EPA will determine the
acceptability of off-site facilities for the receipt of Site chat. As explained in Section 19.2.2, since chat
washing facilities will continue to operate independent of EPA's OU4 remedial actions, the State's general
permit provisions and other State, Federal and local regulations apply with the force of law (to the extent
that they did prior to the ROD) with respect to all on-Site chat washing facilities under these jurisdictions,
respectively. EPA will encourage local, state, and federal authorities to enforce Best Management Practices
and Storm Water Pollution Prevention Plans for facilities on the Site to ensure environmentally protective
chat processing operations. Please see the ROD's Glossary of Terms where EPA has defined and
identified general components of Best Management Practices.
Comment 34: EPA must act as lead agency for oversight of all chat sales.
Response: Chat sales are a pre-existing activity at the Site. To ensure that chat sales continue at the
Site and to further promote the environmentally protective use of chat, EPA will facilitate activities to
support chat sales and will work with its Federal, State and Tribal partners to ensure that all Site chat is
managed according to the criteria provided in the Chat Rule, 40 CFR Part 278, and its preamble. See
response to Comment 32 in this section.
Comment 35(a): Forced Sales or other Disposition of chat during Phase 2: Will the EPA oversee the
Implementation of the 5 year plan and will the EPA pay compensation to the chat owners if it removes the
chat?
Comment35(b) Under the Proposed Plan, upon receiving a Notice from the EPA, it is not clear whether a
chat owner is able to develop a 5 yr plan with EPA under which the owner sells chat during Phase 2, and
whether such sale would be considered an "authorized" or "ordered" sale by EPA.
Response: Owners of chat and/or the land that chat is present on in distal areas will be contacted,
and where these owners agree, chat will be excavated and released to a chat processor or future processing
location located in a previously contaminated area of the Site, injected in mine workings, or disposed in an
on-site repository. If the owners will not release the chat for excavation and disposition, they will be
asked to provide a plan and schedule for final disposition that is consistent with this ROD. Disposition
under the owner's EPA-approved plans must be completed within five years (unless the chat is located in
streams in which case, owners will have only one year to complete disposition under and EPA-approved
plan). If owners do not provide plans that are acceptable to EPA, EPA may take legal action.
The remedial activities identified for Phase 2 will be conducted in the final five years of the Remedial
Action to maximize active chat sales. Until a chat owner is notified (or effectively notified) that EPA
intends to excavate the owner's chat pile or chat base as provided in the OU4 ROD, EPA expects that chat
owners will continue to sell or use their chat subject only to the provisions in Section 19.2.2
(Environmentally Acceptable Chat Use) of the ROD. EPA will evaluate the progress of chat sales at least
every five years. Chat piles and chat bases that remain and that are unmarketable after 10 years will be
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identified and evaluated to see if it can be sold profitably. This determination will be made with input from
the chat/landowners, appropriate Tribal representatives, and the commercial operators.
Comment 36: Would such sales be considered a "remedial activity" under the ROD at that point is not
evident.
Response: Yes. See response to Comment 32 in this section.
Comment 37: If the Chat owner is a restricted Indian, the Proposed Plan does not address whether the
terms set forth in the 5 year plan would be enforced by EPA or DOI.
Response: As part of each five-year review, EPA will evaluate the progress of chat sales. Chat
piles and bases remaining after 10 years will be evaluated for commercial viability. This determination will
be made using input from the chat/land owners, appropriate Tribal representatives, and the commercial
operators. Unmarketable chat piles and bases will be excavated, transported to an on-site chat processor and
released to that processor, or it will be disposed in an on-site repository. Where chat/land owners will not
release the unmarketable chat, they will be asked to provide a plan, including a schedule, for its final
disposition consistent with this ROD. Scheduled disposition under the owners' plans must be completed
within five years. If EPA finds that the plan or schedule is unacceptable, EPA may take legal action.
Where Indians are involved, EPA will coordinate with DOI as explained in ROD Section 19.2.2
(Environmentally Acceptable Chat Use).
Comment 38: In this situation where the owner of the chat does not own the land on which the pile is
located, it is not clear that EPA will facilitate or otherwise order cooperation of the land owner.
Response: This comment concerns remedy implementation and not remedy selection. There are
many chat ownership and land ownership scenarios at OU4. Each situation is fact specific and will be
addressed during remedy implementation. Section 19.2.2 of the ROD provides additional information on
how EPA will work with chat/land owners.
Comment 39: Chat contains hazardous substances under the CERCLA, but it also currently has a
market value and is owned by individuals. DOI does not support EPA's disposal or removal of the chat
during Phase 2 (discussed at pages. 3-4) without payment of just compensation to the chat owners. Any
Notice issued by EPA to Indian chat owners that result in EPA's removal of the chat must include plans for
payment to the Indians. We recommend that all Alternatives in the Proposed Plan be amended to include
such compensatory payments.
Response: EPA plans to remove only unmarketable chat under the Phase 2 procedures that you
reference. No payment will be made since only unmarketable (i.e., chat that cannot be sold) will be
removed. Before EPA makes a determination that the chat cannot be sold, it will evaluate input from the
chat/land owners, appropriate Tribal representatives, and the commercial operators. See ROD Section 4
(Description of the Selected Remedy); and see EPA's responses to comments 36a and 36b above.
Comment 40: DOI supports EPA's funding and activities proposed for "Encouraging Chat Sales."
While EPA must be lead enforcement agency at the Superfund Site, DOI supports EPA's funding of
HAZWOPER training and enforcement of the Off-site rule, as well as the funding of various entities for
additional, concurrent oversight of chat operations consistent with their respective roles as sovereign
entities. The Proposed Plan provides funding to the Quapaw Tribe and the ODEQ for oversight of chat
operations. It does not, however, clarify whether the Tribe and/or State will conduct oversight of
operations on Indian-owned piles, non-Indian owned piles, the commingled piles, or all types of chat piles.
Response: DOI provided clarification on this comment (DOI letter dated September 28, 2007, from
Mr. L. Michael Bogert to Regional Administrator Richard E. Greene). The letter notes that BIA, with the
assistance of other agencies of the DOI, will manage and administer the following:
a) Perform engineering ownership determinations, cadastral surveys, and appraisals, if needed;
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b) Outreach and communication with the Indian owners of restricted chat and land regarding chat
sales and surface leasing;
c) Appraisals of the fair market value of restricted chat and surface leases and provision of copies
thereof to the Indian chat owners and land owners;
d) Necessary tasks associated with the review and possible approval of chat sales contracts and
business site leases,
e) Quantitative analysis of chat removed from Indian-owned restricted chat piles for production
verification purposes;
f) Tasks associated with the accounting of funds and distribution of proceeds from the sale of
restricted chat to Indian owners;
g) Logistics associated with competitive or negotiated sales of Indian-owned restricted chat;
h) Assistance, as required in negotiations between Indian owners of restricted chat and potential chat
purchasers;
i) Coordination of sales and other issues with the relevant offices of Federal, State, and Tribal
governments; and
j) Review and enforcement of sellers' compliance with chat sales agreements and volumetric
recording of chat sales.
EPA will facilitate activities to support chat sales that will include the following:
a) EPA will work with the DOI to facilitate sales of Indian-owned chat.
b) EPA will present a workshop to assist chat/land owners and sellers with chat sales.
c) EPA will provide sample chat sale agreements and site operating plans to chat/land owners and
chat processors.
d) EPA will answer questions about the Chat Rule.
e) EPA will provide technical review to any requests for chat use other than chat mixed in asphalt for
federal transportation projects.
f) EPA will conduct a risk assessment on chat materials that exceed the SPLP and proposed for use
in concrete as specified in the Chat Rule to support the ultimate sale of the chat.
g) EPA will coordinate with DOJ to provide liability protection for chat/land owners.
The Proposed Plan estimated cost included a list of activities related to chat sales and costs associated with
those activities, in the summary of remedial alternatives. EPA has determined since the Proposed Plan was
issued that Hazardous Waste Operations and Emergency Response Standards (HAZWOPER) training will
not be required at chat processing/handling operations since these activities are already covered under the
applicable Mine Safety and Health Administration (MSHA) standards that are already in effect for these
businesses.
Comment 41: EPA must authorize, implement and oversee all aspects of the remedy at the Tar Creek
Superfund Site including chat sales, the key component of the proposed remedy. The EPA's assumption of
such responsibilities is in accordance with the trust responsibility of the United States Government,
(including EPA) to individual Indians owning land, chat or other resources located within the Tar Creek
Superfund Site.
Response: See response to Comment 32.
Comment 42: EPA must bear all costs of such implementation and oversight, including but not limited
to, the establishment of environmental compliance standards, environmental monitoring provided by or
funded by the United States government, any enforcement activities, compliance, and certifications
required by EPA's offsite disposal regulations. Nothing, however, precludes EPA from seeking cost-
recovery for such implementation and oversight against any potentially responsible parties.
Response: Rather than spend Superfund money on remedial action, EPA has a longstanding policy
to pursue "enforcement first" throughout the Superfund cleanup process. See Suarez, J.P., "Enforcement
First for Remedial Action at Superfund Sites" (September 20, 2002). Existing EPA guidance emphasizes
that a major component of the "enforcement first" policy is that potentially responsible parties (PRPs)
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should conduct remedial actions whenever possible. See "Negotiation and Enforcement Strategies to
Achieve Timely Settlement and Implementation of Remedial Design/Remedial Action at Superfund Sites,"
OSRE (June 17, 1999); and see "Guidance on CERCLA Section 106(a) Unilateral Administrative Orders
for Remedial Designs and Remedial Actions," OSWER Dir. #9833.0-la (Mar. 7, 1990). EPA prefers to
achieve PRP-lead cleanups through settlements. Under such settlements, PRPs may undertake certain
remedial action activities at a Superfund site and pay EPA for its work, including the type of work that the
commenter describes. EPA intends to seek such a settlement regarding remedial design and remedial
action for OU4.
Comment 43: Alternative 5, buyout, is the State's preferred alternative. Buyout is the key to the holistic
solution; buyout is not included in EPA's preferred alternative (Alternative 4). Over the past few months,
the State has provided appropriate and compelling justification for buyout. See correspondence to EPA
Region 6 dated April 16, June 11, July 2, and September 21, 2007, attached and made a part of this
administrative record. Although DEQ has had numerous meetings, telephone calls, teleconferences, and
discussions with EPA regarding aspects of the Proposed Plan, EPA did not fully consider buyout as an
alternative.
Response: Based on public comments, the comments of the Quapaw Tribe, the comments of the
State, and facilitated by the passage of the Water Resources Development Act of 2007 (WRDA), EPA
reevaluated the preferred alternative that it released to the public in the Proposed Plan. Instead of the
preferred alternative—Proposed Plan Alternative 4, EPA selected a modified Alternative 5 which includes
relocation and an extended timeframe for chat sales.
Comment 44: The National Contingency Plan (NCP) states that the "purpose of the remedy selection
process is to implement remedies that eliminate, reduce, or control risks to human health and the
environment" Toward that end, the stated "national goal of the remedy selection process is to select
remedies that are protective of human health and the environment, that maintain protection over time, and
that minimize untreated waste.
Response: Comment noted.
Comment 45: It should be noted that "protection of the human health" is at the top of a list of many
more criteria beyond "cost", which appears near the bottom of the list.
Response: Under the NCP, cost can only be considered in selecting a remedy from among protective
alternatives. The remedy selection process requires that alternatives must be demonstrated to be protective
and ARAR-compliant (or justify a waiver) in order to be eligible for consideration in the balancing process
by which the remedy is selected. This sequence of steps ensures that the selected remedy will be protective
of human health and the environment. Cost is a relevant factor for consideration as part of the selection of
the remedy from among protective, ARAR-compliant alternatives. As explained in ROD Section 20.3
(Cost Effectiveness), the selected remedy is cost effective. It is also the least expensive of the protective
remedies, measuring present value.
Comment 46: The DEQ is unclear as to EPA's acceptable uses of chat in non-transportation/non-
construction/non-encapsulation activities. Is there a process to determine if other uses are acceptable? If
so, please clarify.
Response: Under this ROD, only certain non-transportation uses of Site chat described in the Chat
Rule preamble and the preamble-referenced fact sheet would be allowed. Specifically, under this ROD,
Site chat used in non-transportation projects could only be used in cement and concrete non-residential
construction projects as described in the Chat Rule preamble, and in applications that encapsulate the chat
as a material for manufacturing a safe product or as part of an industrial process (e.g., glass, glass
recycling) where all waste byproducts are properly disposed, as described in the June 2007 fact sheet. In
addition, non-transportation cement or concrete project material in question must, on a case-by-case basis,
pass one of the two evaluation methods described in the Chat Rule preamble guidance. The two evaluation
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methods concern testing the material using the Synthetic Precipitation Leaching Procedure, or having a
State environmental agency or EPA conduct a site specific risk assessment with a public comment period.
The following enumerated paragraphs explain how the two Chat Rule preamble evaluation methods will be
used under the ROD:
(1) If Synthetic Precipitation Leaching Procedure (SPLP, EPA SW-846 Method 1312) tests conducted on
the proposed material incorporating chat show that concentrations in the leachate do not exceed the
National Primary Drinking Water Standards for lead of 0.015 mg/1 and cadmium of 0.005 mg/1 and the
fresh water chronic National Recommended Water Quality Criterion for zinc of 120 jxg/1 then the chat use
in question is acceptable under the ROD.
(2) If EPA (or a State environmental Agency, if it chooses to do so) has determined, based on a site-specific
risk assessment and after notice and opportunity for public comment, that leachate from the proposed
material incorporating chat will not cause an exceedance of the National Primary Drinking Water Standards
Maximum Contaminant Level (MCL) for lead of 0.015 mg/1 and cadmium of 0.005 mg/1 in drinking water
sources, and the National Recommended Water Quality Criteria for zinc of 120 jxg/1 in surface waters then
the chat use in question is acceptable under the ROD.
There are certain uses of chat that EPA generally believes will pass one or the other of these evaluation
methods, and these uses include applications that encapsulate chat as a material for manufacturing a safe
product or as part of an industrial process (e.g., glass, glass recycling) where all waste byproducts are
properly disposed, however, the evaluations would still have to be performed on a representative sample of
the chat-containing material in question.
Comment 47(a): The DEQ is concerned that implementation and impact of the off-site rule could make
asphalt mixing plants, trucks and highway sites "facilities" under CERCLA, thereby inhibiting the sale of
chat. The impact of the implementation of the off-site is unclear.
Comment 47(b): The State is concerned that as asphalt mixing facility, the trucks that then haul
the asphalt/chat mixture and/or an entire highway system would become a "facility" under CERCLA for
purposes of the Off-Site rule. This scenario would effectively shut down the sale of Chat in Oklahoma.
EPA should clarify the issues regarding using chat on highways as well as other locations which might be
determined to be facilities under CERCLA.
Response: Section 121(d)(3) of the Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA), 42 U.S.C. § 9621(d)(3), applies to any CERCLA response action involving the
off-site transfer of any hazardous substance, or pollutant or contaminant (CERCLA wastes). That section
requires that CERCLA wastes may only be placed in a facility operating in compliance with the Resource
Conservation and Recovery Act (RCRA) or other applicable Federal or State requirements. That section
further prohibits the transfer of CERCLA wastes to a land disposal facility that is releasing contaminants
into the environment, and requires that any releases from other waste management units must be controlled.
These principles are interpreted in the Off-Site Rule, set forth in the National Contingency Plan (NCP), at
40 CFR 300.440. The purpose of the Off-site Rule is to avoid having CERCLA wastes from response
actions authorized or funded under CERCLA contribute to present or future environmental problems by
directing these wastes to management units determined to be environmentally sound. See 58 FR 49200,
49201 (September 22, 1993).
EPA is presently conducting a pilot project with the U.S. Department of the Interior. Under this pilot
project, DOI is facilitating the commercial sale of chat from certain restricted Indian allotments in order to
determine the efficacy of these sales in ridding OU4 of chat. Since the pilot project is being conducted as
part of a CERCLA response action, it is subject to the Off-site Rule. Accordingly, before any of the chat
sold could be taken to an off-site facility (in this case an asphalt mixing plant), the EPA had to determine
that the facility was acceptable within the meaning of the Off-site Rule. EPA's acceptability determination
did not hinder the sale of chat under the pilot project; consequently, we do not foresee that application of
the Off-site Rule will be a hindrance to chat sales as the commenter suggests. In short, all asphalt mixing
facilities using Site chat would require an acceptability determination under the Off-site Rule, but the
results of our pilot program show that this is not a problem for chat users or sellers.
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Tar Creek OU4 Superfund Site
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February 2007
Highway sites would not be considered "facilities" under the rule because once wastes have been treated
off-site to certain levels, they cease to be considered CERCLA wastes and are no longer governed by the
Off-site Rule. See 58 Fed. Reg. 49200, 49203 (September 22, 1993). For the type of CERCLA waste at
issue (i.e., chat) the CERCLA waste has to be treated to levels that substantially reduce the mobility,
toxicity, or persistence of the wastes. See 58 Fed. Reg. at 49203. Thus an acceptability determination is not
required for the chat once it has been bound in asphalt, so a highway site (e.g., a road using chat mixed with
asphalt) would not be a facility for which an acceptability determination would be needed under the Off-
site rule.
When CERCLA wastes are transferred off-site, intermediate facilities wishing to store CERCLA waste
must be acceptable under the Off-site Rule. See 58 Fed. Reg. 49203. Solely for purposes of interpreting
and implementing the Off-site Rule, "storage" in this context does not include the transport of CERCLA
waste (in a truck for example), and it also does not include the short-term holding of CERCLA waste when
that holding occurs in the normal course of transit. For example, the holding by a chat user of a shipment
of chat for ten days or less at a railroad spur, staging area, or similar place, would be viewed as part of the
transportation process rather than as "storage," so that the chat user's temporary holding place is not subject
to the Off-site Rule.
Comment 48: The inclusion of the chat rule, its preamble and the offsite rule as requirements for the
beneficial reuse of chat at the Oklahoma Tar Creek Superfund Site would create disparity in the sale of chat
in the Tri-State Mining District.
Response: See response to Comment 32.
Comment 49: The EPA Region 6's requirements are a disincentive to the beneficial reuse of chat in
Oklahoma since the impact of the off-site rule would classify various chat sellers and users as owners under
CERCLA and the property on which the chat is mixed would become a facility under CERCLA, thereby
passing Superfund liability on to the very people who are trying to beneficially reuse the chat. These
requirements are diametrically opposed to EPA's stated objective of addressing chat through beneficial
reuse.
Response: There is no disincentive in encouraging the safe and beneficial use of chat from the Tri-
state mining district, located in parts of Oklahoma, Kansas and Missouri. The established criteria presented
in the rule involve chat that is located in the Tri-State mining district. To ensure that Site chat sales
continue and that chat is used in a fashion that is protective of human health and the environment, all Site
chat would be managed according to the criteria provided in the Chat Rule, 40 CFR Part 278, and its
preamble. The remedy selected in this ROD includes these Part 278 waste management criteria. This
means that we are including both the regulations that apply to transportation construction projects and the
preamble guidance that applies to non-transportation, non-residential projects as requirements under the
selected remedy. In addition, only the uses described in the preamble (including EPA's June 2007 fact
sheet; EPA530-F-07-016B) and the transportation construction project uses described in 40 CFR Part 278
will be allowed for Site chat under this ROD.
Comment 50: EPA's Proposed Plan, incorporating the off-site rule, may be violative of the Commerce
Clause of the U.S. Constitution (USCA Const. Art 1, 8, cl.3) and outside the scope of EPA's authority.
Restricting the sale and use of chat in the Oklahoma area of the Tri-State Mining District while not
restricting the sale and use of chat in the Missouri and Kansas areas of the Tri-State Mining District Places
different standards upon the residents and businesses of the area. The economic endeavor of selling chat,
mixing it with asphalt and using it on roadways off of the Superfund site substantially affects interstate
commerce. EPA's Proposed Plan restricts only Oklahoma's activities. The activity in Kansas, Missouri and
Oklahoma should be regulated in the same way.
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Record of Decision
Tar Creek OU4 Superfund Site
Page 85
February 2007
Response: EPA disagrees with this comment. CERCLA is constitutional under the Commerce
Clause, and EPA's selected remedy for OU4 is authorized by CERCLA. The remedy is authorized by
CERCLA because it is consistent with the NCP.
In U.S. v. Lopez, the Supreme Court held that the Commerce Clause empowers Congress to regulate: (1)
channels of interstate commerce; (2) instrumentalities of and persons or things in interstate commerce; and
(3) intrastate activities that substantially affect interstate commerce. United States v. Lopez, 514 U.S. 549,
_, 115 S. Ct. 1624, 1629-30, 131 L. Ed. 2d 626, (1995). CERCLA reflects Congress's recognition
that both on-site and off-site disposal of hazardous waste threaten interstate commerce. United States v.
Olin Corp., 107 F.3d 1506, 1511 (11th Cir. 1997). CERCLA does not violate the Commerce Clause. See
id.
CERCLA Section 104(a)(1), 42 U.S.C. 9607(a)(1), provides in pertinent part that
[w]henever (A) any hazardous substance is released or there is a substantial
threat of such a release into the environment. . ., which may present an imminent
and substantial danger to the public health or welfare, the President is authorized
to act, consistent with the national contingency plan, to remove or arrange for
the removal of, and provide for remedial action relating to such hazardous
substance, pollutant, or contaminant at any time (including its removal from any
contaminated natural resource), or take any other response measure consistent
with the national contingency plan which the President deems necessary to
protect the public health or welfare or the environment.
There is a release at the Site, and, as documented in EPA's Baseline Human Health Risk Assessment and
other Administrative Record documents, there is an imminent and substantial danger to the public health.
So it is appropriate that EPA act, consistent with the NCP. As stated in the preamble to the NCP (55 Fed,
Reg. 8666), the overarching mandate of the Superfund program is to protect human health and the
environment from the current and potential threats posed by uncontrolled hazardous waste sites. This
mandate applies to all remedial actions and cannot be waived. Consistent with the program expectations,
the mandate for remedies that protect human health and the environment can be fulfilled through a variety
or combination of means. These means include the recycling of contaminants. See 40 CFR Section
300.430(c)(9)(iii)(D)(/) (This NCP section was purposely revised to indicate that recycling is an acceptable
means of accomplishing reduction of toxicity, mobility or volume as mandated by CERCLA.) 55 Fed.
Reg. 8666. Under the selected remedy in the OU4 ROD, chat is recycled through the various transportation
and non-transportation uses described in the Chat Rule preamble that EPA has determined are acceptable
under the ROD. In order to ensure that chat use is environmentally acceptable (i.e., to ensure that recycling
is actually occurring), EPA has selected, as part of its remedy for the Site, the chat use requirements
described in ROD Section 19.2.2 (Environmentally Acceptable Chat Use).
In short, CERCLA passes muster under the Commerce Clause, CERCLA Section 104 authorizes actions
that are consistent with the NCP, the NCP authorizes recycling as a means to reduce toxicity, mobility or
volume, and the selected remedy includes chat recycling as part of the remedy. To ensure that recycling is
actually occurring, EPA has selected, using its NCP procedures, the chat use requirements described in
ROD Section 19.2.2.
Comment 51(a): The DEQ is troubled that EPA's preferred alternative does not clearly identify whether all
residents of the Tar Creek area, Indian and non-Indian alike, will receive a release of liability and
contribution protection from EPA for the commerce and beneficial reuse of chat.
Comment 51(b): In discussing Alternative 4 on page 19 of the Proposed Plan, EPA states that "EPA
anticipates that Indian-owned chat sales will be managed pursuant to an agreement between EPA and the
DOI that will define roles and responsibilities. EPA can address the release of chat in accordance with
CERCLA authorities in a manner that will benefit chat/land owners and the environment." Owners' fear of
incurring CERCLA liability from the sale and transport of chat to off-site locations and references the St.
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Record of Decision
Tar Creek OU4 Superfund Site
Page 86
February 2007
Joe Pile (on Indian land) wherein EPA provided a covenant not to sue and contribution protection under
CERCLA in an agreement approved by the United States Department of Justice. EPA states that it plans to
extend that practice upon request.
Comment 51(c): Not until some time later on page 20 are non-Indian chat landowners discussed. See
paragraph 4. There is no mention of a covenant not to sue or contribution protection under CERCLA for
non-Indian chat landowners
Response to 51(a), (b), and (c): While chat sales have occurred on and off Site for many years, EPA
recognizes that chat sales could be impeded by owners' fear of incurring CERCLA liability to the United
States or others arising from unanticipated adverse consequences associated with chat sales. To help allay
the concerns regarding potential future liability arising from the sale and transport of chat to off-site
locations during the Chat Sale Pilot Project, EPA entered into CERCLA administrative settlements with
sellers of the St. Joe Pile, providing a covenant not to sue from EPA for sales made in compliance with the
terms of the agreement, and providing contribution protection pursuant to CERCLA § 113(f)(2), 42 U.S.C.
§ 9613(f)(2). These agreements were approved by the U.S. Department of Justice. Although the Agency
wishes to make clear that these agreements provide no protection from any liability already incurred on the
basis of past acts or current status, the agreements appear to have successfully facilitated chat sales during
the Pilot Project, and it is EPA's intention to extend that practice as chat is sold pursuant to the ROD,
subject to coordination and approval with the Department of Justice.
Comment 52: The DEQ is hopeful that all owners of chat, Indians and non-Indians alike, will be treated
equally under the law and would receive the same release of liability and contribution protection under
CERCLA for the same chat related activities at Tar Creek. At a minimum, EPA must clarify the language
so that all Oklahomans know what protections apply to all parties engaged in the commerce and beneficial
reuse of chat.
Response: Under the remedy selected in the ROD, EPA will present a workshop to assist all
chat/land owners and sellers with chat sales. The purpose of the workshop will be to inform the public
regarding the requirements of ROD Section 19.2.2 (Environmentally Acceptable Chat Use).
Comment 53(a): The DEQ continues to believe that the site-wide hydrogeologic study discussed in the
Proposed Plan needs to include a consideration of the pathway from the Boone to the Roubidoux. DEQ
believes that EPA should cause "no harm", rather than "no further harm" to the groundwater and surface
waters in the area.
Comment 53(b): The EPA hydrogeologic study proposal has not been fully developed. The Department
has concerns with subaqueous disposal without data to evaluate the feasibility and environmental protection
of the Boone and Roubidoux aquifers and the potential for increased acid mine drainage issues. Given the
connectivity between the Roubidoux and Boone aquifer, the Roubidoux aquifer must be protected from
injection of millions of cubic yards of the highest concentration, most leachable waste into the Boone
aquifer. There also needs to be an understanding of any trends which may or may not be occurring over
time with regard to COPCs and pH and how subaqueous disposal may impact or alter those trends and
conditions. An understanding of flow directions, changes in COPC concentrations, and length of time for
equilibration in the mine should be better developed. There also needs to be a concentration established that
is acceptable or not acceptable for continued chat injection, and the possible affects of the increased
(including short term) concentrations of COPC that may appear in springs and seeps should be addressed.
Response to comment 53(a) and (b): To the extent that it can be feasibly assessed, EPA is
investigating the possible connection between the Boone and Roubidoux aquifers as part of an ongoing
hydrogeological study that is being carried out apart from the selected remedy. In addition, the study will
assess the potential for source material injected into the mines to cause harm to ground water and surface
water.
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Record of Decision
Tar Creek OU4 Superfund Site
Page 87
February 2007
Comment 54: The source of water used by chat operations that wash chat prior to use is also a concern
to the Department. It is the Department's understanding that there are no discharges allowed from chat
washing operations and the Department supports that position. Chat operations which wash chat should
also have source water regulated. Stream water should not be used for washing chat but acceptable sources
may include water in subsidence features or ground water in areas where subaqueous disposal will occur.
Response: Chat washing facilities will continue to operate independent of EPA's OU4 remedial
actions, the State's general permit provisions and other State, Federal and local regulations apply with the
force of law (to the extent that they did prior to the ROD) with respect to all on-Site chat washing facilities
under these jurisdictions, respectively. EPA will encourage local, state, and federal authorities to enforce
Best Management Practices and Storm Water Pollution Prevention Plans for facilities on the Site to ensure
environmentally protective chat processing operations.
Comment 55: The EPA should modify the component of the preferred Alternative that addresses waste
material in streams. The Department does not support the use of installation of a flexible membrane liner as
a remediation method. Instead, the Department recommends that EPA adopt the component of Alternative
8 that would completely remove in/near stream waste and integrate it into existing upland chat deposits as
an early response.
Response: The use of flexible membrane liner is only proposed for those sections of a stream where
it may be concluded that significant thicknesses of source materials may exist, and that excavation and
removal of those materials may cause greater harm to the environment compared to the amount of risk
reduction that would be accomplished. For example, if the amount of source material requiring excavation
would result in bank slope stability problems or that the hydrodynamic of the stream would be altered such
that instability problems would be expected to occur in other locations in the watershed, then a flexible
membrane liner would be used. The hydrology model discussed in Section 19.2.3 will be used in the
remedial design to identify areas that the use of a flexible membrane liner will provide the best engineering
approach. Where the remedial design concludes that a liner should be used, a liner is expected to eliminate
the direct contact exposure route and minimize or prevent any further harm to the environment.
Comment 56: Complete removal of waste material from in/near streams would greatly decrease the
injury to the streams and their riparian corridor and would increase the recovery of fish, mussel and other
aquatic biota in the streams. Further, EPA should consider the geomorphology of the streams. Streams in
the area are often chat-choked and have been channelized. Items to consider include, but are not limited to,
restoring meanders, identifying proper gradients and providing clean gravel if necessary to prevent
headcutting conditions.
Response: EPA takes note of the comment and plans to include these stream reclamation concepts
into a design approach (during the Remedial Design phase of the remedy) consistent with approaches that
minimize increased storm water runoff or other damages caused by erosion.
Comment 57: Page 11, paragraph 2: This is very confusing statement - "High concentrations of lead are
addressed under the preferred remedy identified in this Proposed Plan; however, the concentrations of lead
are not so high as to be several orders of magnitude above levels that allow for unrestricted use and
unlimited exposure. Therefore, the lead is not considered to be a principal threat under the NCP;
consequently, there is not expectation under the NCP that the lead be treated." Does this mean that EPA
doesn't have to address lead? What is the reason EPA is addressing lead if it doesn't have to?
Response: Under the NCP, lead at the site is not considered a principal threat waste, which are
characterized as wastes that cannot be reliably controlled in place, such as liquids, highly mobile materials,
and high concentrations of toxic compounds (e.g. concentrations several orders of magnitude above levels
that allow for unrestricted use and unlimited exposure) [(see 55 Fed. Reg. 8666, 8703 (March 8, 1990)].
The source material at the site is generally classified as a low level threat waste rather than a principal
threat waste. If the lead at this Site was classified as a principal threat waste, the NCP has the expectation
that the waste be treated. EPA's statement attempts to convey that because the waste is not a principal
threat waste, the preference for treatment does not have to be met. This does not mean or imply that a
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Record of Decision
Tar Creek OU4 Superfund Site
Page 88
February 2007
remedy to address the risk that lead presents to human health and the environment is not necessary or
required.
Comment 58(a): Page 14, paragraph 1: The clean up levels for lead at the Tar Creek Site should be
consistence with the Cherokee County KS clean up level of 400 mg/kg. The Sites are contiguous and clean
up at the sites should occur at the same time with the same remediation goals.
Comment 58(b): Page 14 "box": Terrestrial Fauna: The clean up levels for lead at the Tar Creek Site
should be consistent with the Cherokee County KS clean up level of 400 mg/kg. The Sites are contiguous
and clean up at the sites should occur at the same time with the same remediation goals.
Response to Comments 58(a) and (b): In developing its remediation goals for OU4, EPA Region 6
considered the Ecological Remediation Goals developed for Cherokee County, Kansas by Region 7. The
Region 7 analysis recommended a range of values for lead in soil that would be protective for exposed
terrestrial wildlife. The Region 7 recommended soil remediation goals for lead ranged between 377 and
1,175 milligrams per kilogram (mg/kg). EPA Region 7 used these remediation goal ranges when it selected
the remediation goals for the Cherokee County, Kansas, Site in the Amended Record of Decision dated
September 29, 2006. Based on the similarity of the ecologies in the two areas (see cite to Toxicologist John
Rauscher's Memorandum), it is appropriate to use the same ranges for OU4 remediation goals. The
remediation goal for lead at Tar Creek is 500 mg/kg because that is within the range recommended in the
Region 7 report, and because EPA Region 6's Baseline Human Health Risk Assessment for Operable Unit
2 (Residential Areas), based on the Integrated Biokinetic Uptake Model (IEUBK), found that 500 mg/kg
was protective of human health. In short, based on the Region 7 report, 500 mg/kg is protective of the
environment and based on the Region 6 study, it is also protective of human health.
Comment 59: Page 20, 3rd paragraph: Include a discussion about transition zone remediation including
discussion about contamination outside the 50 foot transition zone identified in Proposed Plan. The entire
extent of the transition zone should be remediated.
Response: EPA agrees. If concentrations of contaminants in the transitions zone soils exceed
remediation goals, they will be addressed by the remedy. The 50-foot limit was an approximation or
estimate based upon existing data, and it was used to develop a consistent approach and cost estimate for
the remedial alternatives. Actual transition zones may be larger or smaller than fifty feet.
Comment 60: Page 34 paragraph 1: Explain how Alternative 8 will be more difficult to implement than
alternative 4. When dealing with waste in streams EPA will need to get land owner approval to do any
work on their land (removal or membrane placement) and EPA will need to coordinate with chat owners to
move the chat out of the stream or to an existing pile.
Response: With respect to wastes found in streams, Alternatives 8 and 4 are not significantly
different. Alternative 8 proposes to remove all source materials found in site streams through excavation
while Alternative 4 and Alternative 5 (the selected remedy) utilize the same approach with the added
flexibility that allows the selected remedy to address thick deposits of source materials in streams through
the installation of a flexible membrane liner. EPA agrees that access to site streams to address source
materials will have to be coordinated with local land owners and their permission will be sought.
Comment 61: The Federal Government is a fiduciary to the Quapaw Indian chat and land owners who
may be significantly impacted by the Proposed Plan.
Response: The Department of the Interior generally takes the fiduciary role for the Quapaw with
restricted interests at the Site. As explained in the ROD, EPA intends to coordinate with DOI on certain
issues.
Comment 62: Any chat sale program must be credible and lawful under the Comprehensive
Environmental Response, Compensation and Liability Act ("CERCLA"), the applicable law governing this
Superfund Site. Participants in any sales program must know that the program is officially approved and
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Record of Decision
Tar Creek OU4 Superfund Site
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February 2007
adopted by the EPA as an integral part of the remedial plan, and that the lead agency with oversight of this
National Priorities List Site is committed to the sales program for the long term.
Response: See response to Comment 32 in this section.
Comment 63: A successful chat sales program must be allowed to go forward for at least a 25-year
duration, or for the sale of all chat at the Superfund Site, whichever comes sooner. It will take time for the
market to absorb the chat, and the benefits of sales will be maximized if the market is given the chance to
do so. Setting an artificial limit on sales duration will lead to substantial, additional remedial costs. Chat
left unsold is chat which must be disposed of, injected, impounded, or contained at a potentially steep price,
and with uncertain long-term environmental consequences. Chat that is sold for environmentally sound
uses puts money into the Ottawa County economy, and does not have to be disposed of, injected,
impounded, or contained.
Response: Comment noted. Under the ROD, the duration for chat sales was modified to continue
for a period of 30 years.
Comment 64: Consistent with the pilot project for chat sales, the DOI supports the "EPA's intention to
enter into CERCLA administrative settlements with sellers of chat, upon request." (See p.2). However, the
DOI questions under what "appropriate circumstances" the EPA would grant such requests (p. 2, end of 8th
para.). It is unclear from the Proposed Plan whether the EPA would grant such requests to chat sellers if it
is determined that their chat purchaser is in compliance with the State's standard ARARs. It is also unclear
what the chat purchaser will need to show in order to establish that it has obtained all applicable state
permits and is in compliance with the EPA's Chat and Off-Site Rules. Liability protection for chat sellers is
essential.
Response: The determination as to what circumstances are appropriate for EPA to enter into
settlements is a fact specific implementation issue that will be addressed during the Remedial Design or
Remedial Action phase of the remedial process. That is, it is not part of the ROD, but will be decided later,
based on the specific situations involved, as the selected remedy is implemented. EPA will facilitate a
number of activities to help chat owners and landowners better understand the requirements of ROD
Section 19.2.2 (Environmentally Acceptable Chat Use). In particular, as part of the remedy selected in the
ROD, EPA will present a workshop to assist chat/land owners and sellers with chat sales.
Comment 65: The EPA should explicitly authorize the sale of chat as a "remedial activity" under the
CERCLA and establish standard chat processing and transport requirements, applicable to chat operations
for Indian and non-Indian owned chat.
Response: Chat sales are part of the CERCLA remedy. EPA's ROD has various chat use
requirements intended to ensure environmentally acceptable use of Site chat. See ROD Section 19.2.2
(Chat Sales and Environmentally Acceptable Chat Use).
Comment 66: The EPA does not have any current operational, processing or transport requirements
with respect to non-Indian owned chat at the Tar Creek Superfund Site. Although not specifically
mentioned in the Proposed Plan, the EPA apparently would prefer the DOI to establish such standards for
Indian-owned chat and Indian lands. Consistent environmental protection standards must apply to all chat
sales at the Site. Under current law, only the EPA can establish, mandate, and implement such uniform
standards.
Response: Since chat washing facilities will continue to operate independent of EPA's OU4
remedial actions, the State's general permit provisions and other State, Federal and local regulations apply
with the force of law (to the extent that they did prior to the ROD) with respect to all on-Site chat washing
facilities under these jurisdictions, respectively. EPA will encourage local, state, and federal authorities to
enforce Best Management Practices and Storm Water Pollution Prevention Plans for facilities on the Site to
ensure environmentally protective chat processing operations.
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Tar Creek OU4 Superfund Site
Page 90
February 2007
Comment 67(a): The EPA's proposed approach is inadequate because, apart from the federal Clean Water
Act and the State Surface Mining statutes, the State of Oklahoma does not have any "special" permitting or
operational requirements or regulations specifically pertaining to the purchase, processing and transport of
chat within a Superfund Site. The Proposed Plan considers the State's "regulations" to be ARARs for chat
washing facilities and states.
Comment 67(b): It is unlikely that the State regulations would be applicable to the Indian lands and
Indian-owned chat. As a result, the operational requirements necessarily developed by the DOI as part of
the NEPA analysis would likely result in more costly practices for the Indian owned chat and activities
located on Indian land. This will result in unfavorable conditions in the market for the Indian chat and land
owners and may inhibit the sale of all or part of the 40 million tons of Indian-owned chat.
Response: Although EPA's Proposed Plan described the substantive requirements of certain State
regulations as ARARs that was an inaccurate description. In fact, since chat washing facilities will
continue to operate independent of EPA's OU4 remedial actions, the State's general permit provisions and
other State, Federal and local regulations apply with the force of law (to the extent that they did prior to the
ROD) with respect to all on-Site chat washing facilities under these jurisdictions, respectively. EPA will
encourage local, state, and federal authorities to enforce Best Management Practices and Storm Water
Pollution Prevention Plans for facilities on the Site to ensure environmentally protective chat processing
operations. For more about this issue please see ROD Section 19.2.2 (Environmentally Acceptable Chat
Use).
Comment 68: The State is seeking a holistic solution to Tar Creek and our view of this operable unit is
consistent with that vision. We believe that all the actions, particularly buyout, are integral to solving the
human health and environmental problems at the site. Buyout should be the first action completed and
should not be held up during EPA's enforcement actions for RD/RA with PRPs. Buyout could be
accomplished in the first three years and would protect at least two future generations from lead exposure.
Response: EPA has modified the remedy to include relocation as a component. This addition along
with the extended timeframe of 30 years for chat sales, will reduce risk and will also reduce the contained
source material footprints. This effort along with the combined efforts of our Federal and State partners,
will one day achieve a holistic solution for the site.
Comment 69: We believe that the offsite rule and the incorporation of the chat rule, preamble and fact
sheets could adversely impact chat sales and will create a disparity in chat sales in Region 6 and Region 7.
Response: EPA is marginally expanding the requirements of the Chat Rule so that they apply to all
uses of chat from the Site, not just to chat used in federal transportation projects. Our best professional
judgment is 90% of all chat that is taken from the Site and from Region 7 chat piles is currently used in
federal transportation projects. Since chat users that provide chat for federal transportation projects must
already meet the requirements of the chat rule, we estimate that EPA's ROD requirements (see ROD
Section 19.2.2) will barely have an impact.
Section 121(d)(3) of the Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA), 42 U.S.C. § 9621(d)(3), applies to any CERCLA response action involving the off-site transfer
of any hazardous substance, or pollutant or contaminant (CERCLA wastes). That section requires that
CERCLA wastes may only be placed in a facility operating in compliance with the Resource Conservation
and Recovery Act (RCRA) or other applicable Federal or State requirements. That section further prohibits
the transfer of CERCLA wastes to a land disposal facility that is releasing contaminants into the
environment, and requires that any releases from other waste management units must be controlled. These
principles are interpreted in the Off-Site Rule, set forth in the National Contingency Plan (NCP), at 40 CFR
300.440. The purpose of the Off-site Rule is to avoid having CERCLA wastes from response actions
authorized or funded under CERCLA contribute to present or future environmental problems by directing
these wastes to management units determined to be environmentally sound. See 58 FR 49200, 49201
(September 22, 1993).
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Tar Creek OU4 Superfund Site
Page 91
February 2007
Comment 70: Another consequence of Alternative 4 will be that the chat processors would be required
to provide a remedy for the remaining chat bases and fine tailings impoundments at the conclusion of their
operations since the chat processing operations will proceed well past the 20 year time frame of Alt 4. To
include these closure costs into the sales price of chat will undoubtedly result in increase cost of chat,
reduced processing rates and lower purchase prices to the chat owners. We believe that Alternative 4 may
result in large volumes of chat remaining on site, imposing the lead hazards to the current area residents
and their future generations for a long time to come and eventually this chat would have to be dealt with by
a future remedial action. These circumstances would not occur in Alternative 5 since the chat base and fine
tailings ponds of the chat processing operations would be dealt with by the remedy under its longer time
frame the cleanup costs would be borne by the entities that originally created the hazards. Again
Alternative 5 is superior to Alternative 4.
Response: As reflected in the Record of Decision for OU4, the timeframe for chat sales has been
modified. Since residents facing the greatest risk of exposure will now be relocated, the EPA has extended
the timeframe for chat sales an additional 10 years, from 20 years, to 30 years. Additional information on
this modification is in ROD Section 4.0 (Description of the Selected Remedy).
Comment 71: Both alternatives assume early 10% of the newly created fine tailings from chat washing
will be dealt with by the remedy. The bulk of the newly created fine tailings are expected to be injected into
the mine workings by the chat washers in a closed loop system. The closed loop system utilizes mine water
pumped from the mines to wash the chat and dispose of the fines by gravity feed back into the mine
workings. This system is currently not working, reportedly due to failure of the down-hole water supply
pump that is located too close to the fines injection well. If this system is not used by the chat washers as
planned (or if injection is rejected by the hydrogeologic study), the consequence is that the remedy may
underestimate the volume of newly washed fines to be injected, i.e., it does not account for an estimated
3.165 million yd3 of newly washed fines. The estimated cost to inject this volume of material is about
$18.2 million. Under Alternative 4, the chat processors would eventually be responsible for cleanup of the
newly washed fine tailings since the OU4 remedy would have been completed many years prior to closure
of the chat processing sites. This has the potential to shut down chat sales completely which would result in
a future remedy for the huge volume of unprocessed chat at a much greater than current remedial options.
Current remedies depend on chat sales to deal with reduction in volume of chat. Under Alternative 5, this
material would be dealt with by the remedy under its longer time frame.
Response: If injection of fines is found to be infeasible or not comply with the ARARs, then chat
processors will be expected to continue following the Best Management Practices for the handling of fines.
Where new fines are being added on top of existing tailings ponds, the increase in the cost of the remedy is
negligible since the overall footprint of the tailings pond would not be expected to change. In this situation,
EPA would wait until chat washing was concluded prior to implementing a cover system at that location.
Comment 72: Table C-2 Phase 2 Activities Item 14 p 5/8, if you assume that 76% of all the chat is
processed and 9,380,000 yd3 which implies that there will be 39,083,333 yd3 of chat with an addition
7,035,000 yd3 for a sum total of 46,118,333 yd3 which is more volume than the amount of chat for use that
is available. Please clarify.
Response: Modifications are reflected in the ROD.
Comment 73: Primary aspects of the current Plan DEQ are not in agreement on: 1) cost appears to be
the sole factor in the Preferred Alternative Selection 2) Cost evaluation for Alternative 4 and 5 is vague and
appears misrepresented 3) permanent relocation is not in the Preferred Alternative 4) chat sales are not a
component of the remedy 5) potential adverse surface water impacts are not addressed
Response: With respect to items 1 and 2, EPA implemented a detailed analysis process in
accordance with the nine criteria prescribed by the National Contingency Plan (NCP) (40 CFR Part 300),
which includes consideration of cost. Under the NCP, cost can only be considered in selecting a remedy
from among protective alternatives. The remedy selection process requires that alternatives must be
demonstrated to be protective and ARAR-compliant (or justify a waiver) in order to be eligible for
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consideration in the balancing process by which the remedy is selected. This sequence of steps ensures that
the selected remedy will be protective of human health and the environment. Cost is a relevant factor for
consideration as part of the selection of the remedy from among protective, ARAR-compliant alternatives.
In many instances, since certain components of select remedies were reasonably similar, detailed analysis
was limited to those criteria which were significantly different. Cost was one of the few criteria where the
difference between alternatives was significant, and therefore merited substantial comparison between
alternatives. With respect to item 3, EPA has reconsidered the inclusion of a voluntary buyout as part of
the remedy. This decision is reflected in the ROD. Chat sales are part of the remedy for OU4.
Requirements to ensure environmentally acceptable chat use are part of the remedy. Removal of source
materials from in-stream locations and ultimately from the watershed will prevent or limit discharges of
chemicals of concern (COC) from source materials into surface water. However, surface water remediation
is generally not part of OU4.
Comment 74: Cost Evaluation - Several fundamental changes to the assumptions that have an impact on
the cost -- it assumes that the same amount of material remains after the end of Phase I for both
Alternatives 4 and 5 and it decreases the time frame for Alt. 5 from 35 years to 30 years. DEQ believe that
this assumption is flawed. The additional time should result in more chat being sold, leaving less to manage
under Phase II and decreasing the cost. It is not clear why EPA changed this but it appears to be a way to
make Alternative 5 less attractive from a cost perspective. We calculated the net present value of
Alternative 5 using the 35 year timeframe. The result was a cost difference of $20,948,583 between
Alternative 4 and Alternative 5. It is worth noting here that the administrative cost of URA is estimated at
$17,358,447.
Response: EPA included relocation in its selected remedy for OU4 and has extended the timeframe
for chat sales to 30 years. With the passage of WRDA, certain cost savings can be realized, and this makes
the selected remedy, including relocation, more cost effective. For a detailed discussion on the cost savings
please refer to the OU4 ROD at Section 20.3 (Cost-Effectiveness).
Comment 75: If Alternative 4 does not remove chat at the rate assumed in the 20 years, the cost of that
alternative will be much higher. The 1.9 million tons per year estimate is higher than the current rate of 0.9
million tons land is based on an expanding market. Recent trends appear to show a slowdown due to high
fuel costs and an associated slowdown in asphalt road construction. There is no direct way to increase the
chat usage rate since sales are not part of the remedy.
Response: EPA's preferred alternative was modified to extend chat sales an additional 10 years
(from 20 to 30 years). This modification will enable more chat to be removed from the site, thus reducing
the volume of chat that may need to be addressed in the remedial action. The remedial cost estimates were
prepared using current year (2007) pricing data and forecast over a 30-year construction and operation and
maintenance period to determine net present value. A discount rate of 7 percent was used in the net present
value analysis of alternatives, the discount is calculated before taxes and after inflation. The cost criterion
analysis for this evaluation was performed in accordance with EPA guidance and cost estimates are
expected to be accurate within a range of -30 to +50 percent.
Based on State, Tribal and community concerns, and the passage of relocation language contained in the
Water Resources Development Act of 2007 (WRDA), EPA reevaluated relocation and the selected remedy
for OU4 was also modified to include relocation. Thus, any remaining target properties not addressed
under the State buyout program will be addressed under EPA's selected remedy. As provided by WRDA,
the voluntary relocation will not follow the Uniform Relocation Act regulations, but will continue to follow
the procedures and priorities established by LICRAT and will be implemented by LICRAT.
With the passage of WRDA, certain cost savings can be realized, and this makes the selected remedy,
including relocation, more cost effective. For a detailed discussion on the cost savings please refer to the
OU4 ROD at Section 20.3 (Cost-Effectiveness).
Comment 76: The cost evaluation also fails to consider how relocation would enhance production by
the use of larger equipment, fewer restrictions on roads, etc. The cost difference could be significant.
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Response: With the passage of relocation language contained in the Water Resources Development
Act of 2007, EPA reevaluated relocation and the selected remedy for OU4 was modified to include
relocation. Certain cost savings were identified, enabling the selected remedy to be cost effective. For
additional information on the cost savings, please see the OU4 ROD at Section 20.3 (Cost-Effectiveness).
Comment 77: Reiteration of DEQ April 16, 2007 comments that were unsatisfactorily addressed - some
new language is added. Permanent buyout must be included in the Preferred Alternative. The environment
in which the OU4 remedy will be implemented is of a singular character. The chat piles, mill ponds and
other contaminant sources are located in, around, and among the residential areas of Picher, Cardin, and
Hockerville, The movement of contaminant sources and the use of heavy construction equipment in so
populated an area will pose an unacceptable risk to the residents.
Response: Based on comments like this from the State, comments from the Quapaw Tribe,
comments from the affected community, and based on the favorable provisions of the WRDA of 2007,
EPA reevaluated relocation which it had rejected in the Proposed Plan. Based on our findings, the selected
remedy for OU4 was modified to include relocation. Additional information on this modification is in
ROD Section 4.0 (Description of the Selected Remedy).
Comment 78: The construction aspects of the remedial alternatives are likely to require imposition of
certain significant use restrictions that members of the community will consider unacceptable. These
restrictions include street barricades for extended durations, temporary disconnection of utilities, use of
earthmoving equipment in residential areas, and if necessary, prolonged temporary relocations of residents.
Other impacts would be noise, vibrations and traffic congestion. Land use restrictions in the form of
institutional controls on source material repositories will also impose serious restrictions on residents that
many may find unreasonable. Relocation would avoid the impact and inconvenience associated with these
restrictions. Such relocation would, of necessity, be long-term and could well last for more than a decade.
Temporary relocation for so prolonged a period of time would place an unacceptable burden on the
community. Perhaps, most importantly, human exposure to chemicals of concern in fugitive dust and
source materials deposited on streets and roadways during urban remedial operations on source materials
poses risks to site residents.
Response: All of the restrictions noted in the above comment were evaluated by EPA in the
December 2007 Feasibility Study, that is part of the OU4 Administrative Record. Based on public
comments, the comments of the Quapaw Tribe, the comments of the State, and facilitated by the passage of
the Water Resources Development Act of 2007 (WRDA), EPA reevaluated the preferred alternative that it
released to the public in the Proposed Plan. Instead of the preferred alternative—Proposed Plan Alternative
4, EPA selected a modified Alternative 5 which includes relocation and an extended timeframe for chat
sales.
Comment 79: The impacts to the communities both from existing conditions and the implementation
of the remedy warrant the relocation of residents. The discussion in Section 5 should reflect this.
Response: Based on public comments, the comments of the Quapaw Tribe, the comments of the
State, and facilitated by the passage of the Water Resources Development Act of 2007 (WRDA), EPA
reevaluated the preferred alternative that it released to the public in the Proposed Plan. Instead of the
preferred alternative—Proposed Plan Alternative 4, EPA selected a modified Alternative 5 which includes
relocation and an extended timeframe for chat sales.
Comment 80: The revised Preferred Alternative does not discuss flood management in a meaningful
way. It is discussed in the Feasibility Study but is not in the Proposed Plan. EPA had agreed to incorporate
this but failed to do so. We have discussed at length that the design of individual sites will require water
balance calculations and the design of features to mitigate flooding. The State believes that the removal of
chat piles, which have tremendous storage capacity, will significantly alter storm water runoff and removal
of these features from the surface will increase the potential for flooding. A regional flood management
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plan needs to be included in the Preferred Alternative to consider and plan for the regional impact of the
remediation
Response: EPA acknowledges this concern and has plans for addressing this during the Remedial
Design. That is, EPA sees this issue as an implementation issue to be addressed during RD, rather than as a
remedy selection issue. Nonetheless, this concern has been acknowledged and addressed in this ROD. In
addition, the hydrologic study will begin to look at issues such as the storage capacity of chat piles and how
the piles recharge and discharge over seasonal weather variations. This information will be useful in
addressing this concern. In addition, as stated in the FS Report, best management practices for the control
of storm water runoff during construction and engineering controls will be implemented as necessary to
abate the potential for increased runoff.
Comment 81: The preferred Alternative is silent on how the rural residences that participate in the
buyout will be addressed. We recommend that you indicate that these will be managed similar to the
transition zone soils. We also recommend that you add similar direction on managing the soils in the
footprints of homes removed by the buyout. EPA's response was to have the US ACE funding that covers
demolition of properties cover this. However, our understanding is that the US ACE authority is limited to
demolition, NEPA and relocation of road and utilities and does not cover soil cleanup. The US ACE
funding is not adequate to address this. Soil remediation for soils above the action level is consistent with
EPA authority under CERCLA for this site.
Response: EPA does not plan to remediate any residential properties that are involved in the State's
relocation effort, since the land use of these properties will change. A change is expected for residential
and commercial settings in Picher, Cardin and Hockerville which are included in the voluntary relocation.
Future land use of the properties that are purchased as part of the State's voluntary buyout being conducted
by the LICRA Trust is not stipulated in their authorizing legislation (Oklahoma Senate Bill 1463);
however, the Trust will hold the title to the properties acquired through the buyout.
Though EPA will not take an interest in any real estate as part of the relocation elements of the OU4 ROD,
EPA will provide funds to the LICRAT to use for relocation of residents in targeted areas. The State has
agreed that the ODEQ will file a "Notice of Remediation or Related Action Taken Pursuant CERCLA, and
the Creation of an Easement" on each property acquired by LICRAT, pursuant to the State's authority
under Oklahoma Statutes 27A § 2-7-123(B), and that this easement will restrict access to the property to
uses that EPA agrees are compatible with the remedy selected in the OU4 ROD.
The Quapaw Tribe adopted a zoning ordinance in 2007 that established planned uses of Quapaw lands.
The goal of the zoning ordinance is to preserve all future uses of the land including residential, agricultural,
conservation, forestry, industrial and commercial.
Structures that remain after residents have been relocated will be removed or demolished and disposed by
the LICRA Trust.
Comment 82: The cost for cleanup of rural residences appears low based on EPA's past costs. The
estimated average cost should be closer to $50,000 per yard, which is relatively close to the average cost of
buying out residences altogether under the ongoing buyout assistance program.
Response: The remedial cost estimates were prepared using current year (2007) pricing data and
forecast over a 30-year construction and operation and maintenance period to determine net present value.
A discount rate of 7 percent was used in the net present value analysis of alternatives and also used before
taxes and after inflation. The cost criterion for this evaluation was performed in accordance with EPA
guidance and cost estimates are expected to be accurate within a range of -30 to +50 percent.
Based on State, Tribal and community concerns, and the passage of relocation language contained in the
Water Resources Development Act of 2007, EPA reevaluated relocation and the selected remedy for OU4
was modified to include relocation. Thus, any remaining properties not addressed under the State buyout
program will be addressed under EPA's selected remedy. As provided by WRDA, the voluntary relocation
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will not follow the Uniform Relocation Act regulations, but will continue to follow the procedures and
priorities established by LICRAT and will be implemented by the Trust, as part of the State of Oklahoma's
voluntary buyout. As a result of this modification, relocation as provided in the selected remedy will be
cost effective.
Comment 83: The assumptions on the volume of chat sales in EPA's preferred alternative seem
unreasonably optimistic. Chat sales are reportedly going down. There is no contingency for these sales
volumes assumptions not being achieved.
Response: EPA assessed information from chat processors and others in determining that
approximately 95% of the chat will be removed from the site over a 30 year period through commercial
sales. Allowing chat sales to continue for the extended period of time contributes to a more cost effective
remedy since less chat will remain on-site that would need to be addressed. Nonetheless, as part of the
five-year reviews that EPA will perform at the site, EPA will evaluate the progress of chat sales. Chat piles
and bases remaining after 10 years will be evaluated for commercial viability. This determination will be
made using input from the chat/land owners, appropriate Tribal representatives, and the commercial
operators. Also, chat sales are an integral part of the remedy and EPA will facilitate activities to support
the sale of chat. Additional information on the types of activities EPA will facilitate is presented
throughout this OU4 ROD.
Comment 84: The inclusion of chat sales as a component of the proposed remedy is an implicit
recognition that there is significant residual value in the chat remaining at the Site.
Response: EPA agrees with the commenter that much of the Site chat has commercial value. The
marketable chat, however, is all privately owned, so any revenue generated from its sale would accrue to
those owners. Nonetheless, the sale of the chat and its use in an environmentally acceptable manner as
called for in the ROD, will address a large part of the source material on the Site, and keep remedy costs
down. There is also much chat that is unmarketable because it is intermingled with unsuitable material, or
because it is located in such an inaccessible area or in such a small pile that it would cost too much to
retrieve—making it unprofitable to market. This unmarketable chat will be addressed as provided in the
ROD.
23.3 Community Outreach History
Throughout the history of the Tar Creek Superfund Site (the "Site"), the U.S. Environmental Protection
Agency (EPA) in coordination with the Oklahoma Department of Environmental Quality (ODEQ), and the
Quapaw Tribe has kept the community, public, governmental entities, citizen advisory groups and
interested parties informed of Superfund response actions, and involved these groups in planning.
The EPA used various methods for informing communities on site activities at Superfund sites, and for
seeking public participation in the National Contingency Plan (NCP) process. One routine activity EPA
uses for updating a community is the development of site Fact Sheets, and newspaper notices.
Informational Fact Sheets at Superfund sites are routinely mailed to individuals on the site mailing list,
which includes community members located within approximately one mile of the site, elected officials,
and other interested parties who have requested information or who have attended public meetings
At the Site, EPA met with community members and performed various outreach activities in response to
the Site-specific needs of the community. This included responding to citizens, neighborhood associations,
and other community organizations through informal discussions, community open houses, and public
meetings. The site mailing list is included in Index.
Under the statutory requirements of Section 121(c) of CERCLA, 42 U.S.C. § 9621(c), and its implementing
regulation 40 CFR § 300.430(f)(4)(ii), every five years, EPA is required to review sites it has addressed
under Superfund where hazardous substances remain on-site above concentration levels that allow for
unrestricted use and unrestricted exposure. Three five-year reviews have been performed at the Tar Creek
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Site. The first was completed in April 1994, the second five-year review was completed in April 2000 and
the third review was completed in September 2005. The most recent Five-Year Review Report is available
online at http://www.epa.gov/earthlr6/6sf/pdffiles/tc_5yr_2005-09.pdf. EPA interviewed local citizens as
part of each one of these Five-Year Reviews.
Listed below is a detailed summary and chronology of the various public outreach efforts:
A Memorandum of Understanding was signed in May 2003 between the EPA, the DOI, and the
U.S. Army Corps of Engineers. The purpose of this Memorandum is to facilitate a coordinated response to
environmental contamination, physical safety concerns (open mine shafts, subsidence, and flooding), and
poor economic conditions at the Tar Creek area. Other participants include the U.S. Fish & Wildlife
Service, the U.S. Geologic Survey, the U.S. Bureau of Indian Affairs, and the Tribes.
On December 9, 2003, the EPA signed an Administrative Order on Consent (AOC) with three
Potentially Responsible Parties (PRPs), including DOI, Blue Tee Corp., and Gold Fields Mining
Corporation, to conduct the Remedial Investigation/Feasibility Study (Remedial Investigation/Feasibility
Study) for OU4. Under the terms of the AOC, the EPA prepared the risk assessments for OU4 based on
data collected by the PRPs and EPA.
March 29 to April 28, 2005, a three-phased Site Reconnaissance was conducted. During the Site
Reconnaissance, field characterization of the mine and source materials was conducted and sampling sites
for the Remedial Investigation were selected with concurrence of EPA, the ODEQ, the Quapaw Tribe and
other participating organizations. Field sampling and investigations were conducted in May and concluded
in October 2005.
November 2005 - Meeting with stakeholders, conducted to discuss draft documents (draft
Ecological and Human Health Risk Assessments, the modified Remedial Action Objectives-including the
draft Preliminary Remediation Goals) and to provide additional insight to our partners regarding EPA's
planned schedule for preparing a Record of Decision for Operable Unit 4 (OU4). A facilitator and court
reporter were utilized.
December 2005 - The potentially responsible parties (PRPs), Blue Tee Corp, and Gold Fields
Mining, L.L.C. funded in part by the U.S. Department of the Interior submitted a draft Feasibility Study
(FS) to EPA. The draft FS was posted on a secured website for EPA's partners to review. EPA's partners
that reviewed and commented on the FS included: The Oklahoma Department Environmental Quality
(ODEQ), Quapaw Tribe and other local Tribes.
January 2006 - EPA presented its draft Preferred Alternative to the EPA's Remedy Review Board.
Representatives from ODEQ and the Quapaw Tribe, were present and presented their concerns.
The U.S. Army Corps of Engineers (USACE) released a report concerning the threat of subsidence
in Ottawa County. This report caused EPA to reevaluate its plans for remediation of the Site.
February 2006 - EPA notify the PRPs it will revise the FS, due to new information presented in
the USACE subsidence report, and due to impacts that the potential State relocation of Site residents could
have on remedial alternatives that had been evaluated in the FS.
March 2006 - Draft Proposed Plan modified to reflect subsidence considerations (internal review).
May 2006 - MOU Principals Meeting - The meeting was held at EPA Region 6 office, 1445 Ross
Avenue, Dallas, Texas. Discussions included the impacts of the Subsidence Report on Tar Creek
activities, next steps and to confirm schedules for all site projects. The goal was to maintain coordination
and enhance possibilities for a holistic approach at Tar Creek. As provided in the MOU, EPA meets with
stakeholders. Attendees were: Gen Dorko, USACE, Bob Laidlaw/DOI, Miles Tolbert, Office of the
Secretary, and John Berrey/Quapaw Tribe
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December 2006 - Draft Proposed Plan and draft FS are made available to ODEQ, the Quapaw
Tribe and the 10 Downstream Tribes for review/input (40 CFR §300.515(h)(3)).
January - March 2007 - Numerous meetings, consultations and conference calls are conducted
with all affected Tribes, the state, and DOI, to discuss the December 2006 draft Proposed Plan and
concerns (40 CFR §300.515(h)(3)). Both the State and the Quapaw Tribe express concerns regarding the
land use. Specifically, the Tribe and the ODEQ essentially said that the proposed remedial alternatives
capped too much contaminated material in place. They essentially said that this capped area would leave
too great a footprint on the land, impeding future use. Concerns identified by ODEQ and the Tribe
included:
Land use concerns/footprint, tribal lifestyle,
Operations and Maintenance associated with the preferred alternative,
The use of too much soil for capping.
January 22, 2007 - Tribal Consultation - Coordination Meeting. Executive Order 13275 was
signed November 6, 2000, and established several provisions regarding consultation and coordination
between Federal agencies undertaking actions that have tribal implications. Tribal Consultation meeting
were held to seek meaningful and timely communications and to seek, discuss and consider tribal views
and tribal interests. A meeting for tribal consultation was held on January 22, 2007 at the Tribal Complex
facility in Miami, Oklahoma. In attendance were: Nancy John/Cherokee Nation, Roxanne Weldon/Eastern
Shawnee Tribe of Oklahoma, Mike Rutledge/Miami Tribe of Oklahoma, John Ballard/Modoc Tribe of
Oklahoma, Rosanna Sheppard/Ottawa Tribe of Oklahoma, Jim Dixon Peoria Tribe of Indians of Oklahoma,
Tim Kent/Quapaw Tribe of Oklahoma, Paul J. Barton/Seneca-Cayuga Tribe of Oklahoma and Jodi
Hayes/Shawnee Tribe Brandi Ross/United Keetowah Band of Cherokee Indians of Oklahoma and Christen
Creson/Wyandotte Nation. Upon completion of the consultation and before the proposed plan was released
to the public, EPA Region 6 Superfund Division Director meet again with the Tribes to explain the
Agency's final decisions for the proposed plan. The Agency complied with the requirements of the
Executive Order while transmitting the draft proposal.
January 23 thru January 24, 2007 - Meeting with State and Quapaw Tribe in EPA's office -
discussion ODEQ and Quapaw Tribe's modified alternative, provide clarification and answer questions
regarding costs, assumptions made etc.,
January 31, 2007 - Tribal Consultation - Technical Meeting - In attendance were: Nancy
John/Cherokee Nation, Roxanne Weldon/Eastern Shawnee Tribe of Oklahoma, Mike Rutledge/Miami
Tribe of Oklahoma, John Ballard/Modoc Tribe of Oklahoma, Rosanna Sheppard/Ottawa Tribe of
Oklahoma, Jim Dixon Peoria Tribe of Indians of Oklahoma, Time Kent/Quapaw Tribe of Oklahoma, Paul
J. Barton/Seneca-Cayuga Tribe of Oklahoma and Jodi Hayes/Shawnee Tribe Brandi Ross/United Keetowah
Band of Cherokee Indians of Oklahoma and Christen Creson/Wyandotte Nation
February 21, 2007 - Inter Tribal Environmental Counsel (ITEC) meeting - EPA's Region 6
Division Director expressed EPA's desires to receive the Tribes input on the Consultation Process and
provide a status of his efforts.
February 28, 2007 - Regional Tribal Operations Committee (RTOC) meeting
March 1, 2007 - Weekly conference call with ODEQ and Quapaw Tribe to discuss progress of
their development of a modified alternatives and clarification on assumptions
March 2, 2007 - E-mail sent to all Tribal Environmental Directors listed above providing
clarification on the 1/22 consultation meeting requesting their input on the Consultation Process and the
envisioned date to have a public meeting.
March 9, 2007 - EPA met with Quapaw Tribe to discuss cost tables for OU4
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March 14, 2007 EPA met with representatives of the Quapaw Tribe and ODEQ to discuss their
modified suggested alternative for OU4.
March - July 2007 - Proposed Plan modified, where possible, based on input from Quapaw Tribe,
ODEQ and other affected Indian Tribes in the Tar Creek area. Input included concerns of water quality,
health issues, chat in mine works, chat in mine workings, drainage around mine works and chat piles. FS is
also modified.
Fact Sheet/Newsletters
All Fact Sheets and Newsletters were mailed to all listings on the Tar Creek Superfund Site mailing list,
which include EPA state and federal partners, Oklahoma local government and all eleven Indian Tribes in
the Tar Creek area.
June 2007/Tri-State Mining District - Chat Mining Waste
April 2007/Maintenance of Soil
April 2007/Residential Soil Sampling
March 2004/Update - Overview/Update of site activities
January 2004/Chat Piles & Mill Ponds - Fact Sheet informing public of the Administrative Order on
Consent for Operable Unit 4 (chat piles) to conduct the Remedial Investigation /Feasibility Study (RI/FS).
November 2004 - Fact Sheet - Information Yard Remediation
August 2003/Tar Creek Site News - Continued cleanup activities
May 2003/TarCreek News - Information on the removal of contaminated soil from properties in North
Miami
May 2003/Environmental News - EPA announced its signing of a Memorandum of Understanding (MOU)
with the U.S. Dept. of the Interior and the U.S. Dept. of the Army to develop and implement solutions to
the human health and environmental threats posed by the Tar Creek Superfund site locate din northeastern
Oklahoma and other states.
Public Notices
All notices were published in the Miami News Record
November 2005/Five-Year Review of Site Remedy
July 2004/Notice of Five-Year Review of site Remedy
Community/Stakeholders meetings
Meetings were held at various locations including the Miami Civic Center, Tribal Complex and Picher
Cardin High School
January 2007/Tribal Consultation - Coordination Mtg.
February 2007/RTOC Meeting
February 2007/ITEC Meeting
March 2007/Quapaw Tribe & ODEQ
November 2005/Stakeholders Meeting
March 2005/Watershed - Update activities for the site and discussion of Memorandum of Understanding
March 2004/Open House - Overview of site activities, Exhibits, One-on-One discussions
March 2004/Community Meeting
June 2004/Property Owners Meeting
24.0 TECHNICAL AND LEGAL ISSUES
24.1 Technical Issues
In the Proposed Plan for OU4, EPA proposed injecting chat and fine tailings into the underground mines as
a permanent disposal method. The proposed inclusion of this technology into the overall remedial strategy
for OU4 was based on positive results from pilot studies conducted at the Site. EPA received several
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comments from the affected community with concerns about the full-scale application of injection. These
commenters were concerned about the long-term impacts on the ground water and surface water at the Site
and downstream of the Site. In the Proposed Plan, EPA proposed including the implementation of a
hydrogeologic study into the remedial strategy to address these community concerns. Our proposal
essentially said injection would only be undertaken as part of the Remedial Action if the results of the
hydrogeologic study were favorable. This approach is consistent with the Underground Injection Control
(UIC) regulations that are identified as an ARAR for the selected remedy. The UIC regulations define the
type of mine backfill well described in this ROD as a Class V injection well. Therefore, as part of the
remedial action, it must be demonstrated that injection activity does allow the movement of fluid
containing any contaminant into underground sources of drinking water supplies, if the presence of that
contaminant may cause a violation of the primary drinking water standards under 40 CFR Part 141, other
health based standards, or may otherwise adversely affect the health of persons. The hydrogeologic study
will be used to address this criterion. If the study does not demonstrate that the injection can meet the UIC
regulations then EPA will not proceed with full-scale implementation and will use capping as the sole
technology for the fine tailings and disposal in a repository or release to a chat processor for other source
material.
The implementation of the hydrogeologic study is currently underway. EPA has met with the State and
Tribes to discuss the scope of the work. A work plan that will guide the work will be forwarded to the
Tribes and the State for review in the first quarter of 2008. The implementation of the work is expected to
take 3 years.
EPA conducted several pilot studies to evaluate the feasibility of injecting chat and fine tailings fines into
the flooded mine workings at the Site. Pilot studies were conducted at the locations of the Montreal and
Craig mines using pile-run chat (i.e., unwashed chat containing both the gravel-like material and the fine
tailings). Pilot studies were also conducted at the Tulsa mine, using the fine tailings from a chat washing
operation. The details of the pilots are contained in the Interim Data Report for the Chat Placement Pilot
Study (February 2006) and the Chat and Chat Fines Placement Pilot Studies Report (July 2006).
24.2 Legal Issues
Paperwork Reduction Act
The information collection requirements in this ROD are the essentially the same as those required under
EPA's Criteria for the Safe and Environmentally Protective Use of Granular Mine Tailings Known as
Chat" (the "Chat Rule"), 40 CFR Part 278. The difference is that, under this ROD, EPA is marginally
expanding the information collection requirements of the Chat Rule so that they apply to all uses of chat
from the Site, not just to chat used in federal transportation projects. Our best professional judgement is
90% of all chat that is taken from the Site is currently used in federal transportation projects. Since chat
users that provide chat for federal transportation projects must already meet the paperwork requirements of
the Chat Rule, the paperwork requirements established under this ROD will only expand application of the
paperwork requirements by less than 10%. Moreover, this ROD's expansion of the information collection
provisions will probably not affect any more parties than are already affected by the paperwork
requirements of the Chat Rule. The reason that no additional parties will be affected is that there are a very
limited number of operators, and agencies involved. See "Assessment of Costs, Benefits, and Other
Impacts of Chat Use in Transportation Projects" (January 2006) at pp. 18-19.
The Chat Rule information collection requirements have been submitted for approval to OMB under the
Paperwork Reduction Act, 44 U.S.C. 3501 et seq. via the preamble to the Chat Rule (72 Fed. Reg. 39331-
39353) instead of a separate Information Collection Request (ICR) document, since the burden associated
with this rule is insignificant. Since information collection requirements established in this ROD only
marginally expand the Chat Rule requirements, and since they probably do not affect any more parties,
EPA is relying on the Preamble discussion of the information collection requirements made in the Chat
Rule to satisfy the OMB Paperwork Reduction Act approval requirements for this ROD.
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The certification, reporting, and record keeping required under the Chat Rule and this ROD are necessary
to ensure the safe use of the product containing chat. Certification, recordkeeping and reporting
requirements under this ROD are not subject to confidentiality restrictions. Since additional paperwork
burden associated with this ROD is insignificant, a separate ICR is not necessary. The burden is projected
to affect a limited number of entities. These include: three State governments (Oklahoma, Missouri,
Kansas), one Native American Tribe (Quapaw Tribe of Oklahoma), and no more than fifty sand and gravel
companies located in the States of Oklahoma, Missouri, and Kansas (NAICS 4233202). It is estimated
that there will be an insignificant additional burden associated with the paperwork requirements under this
ROD. In fact, due to the conservative nature of the burden projections made in the preamble to the Chat
Rule, it is estimated that the total burden on affected entities (i.e., the combined burden of the paperwork
requirements of this ROD and the Chat Rule) will remain within the total estimated burden projected for
the Chat Rule alone, as described in the preamble to the Chat Rule (72 Fed. Reg. 39331-39353).
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PART 4: BIBLIOGRAPHY
AATA, 2004a. Data Gap Analysis, Tar Creek OU4 RI/FS Program. Tar Creek Superfund Site, Ottawa,
County, Oklahoma.
AATA, 2004b. Work Plan, Tar Creek OU4 RI/FS Program. Tar Creek Superfund Site, Ottawa, County,
Oklahoma.
AATA, 2005a. Preliminary Site Characterization Summary (PSCS) Report, Tar Creek OU4 RI/FS
Program. Tar Creek Superfund Site, Ottawa, County, Oklahoma.
AATA, 2005b. Remedial Investigation Report, Tar Creek OU4 RI/FS Program. Tar Creek Superfund Site,
Ottawa, County, Oklahoma.
AATA, 2005c. Sampling and Analysis Plan, Tar Creek OU4 RI/FS Program. Tar Creek Superfund Site,
Ottawa, County, Oklahoma.
Adams, R., L. Bingham, and M. Williams. 2005. Personal communication about chat processing practices
in the Tar Creek Site. Ottawa County, Oklahoma.
Brichta, L.C. 1960. Catalog of recorded exploration drilling and mine workings, Tri-State Zinc-Lead
District—Missouri, Kansas, and Oklahoma: U.S. Bureau of Mines Information Circular 7993.
Brown and Root Environmental. 1995. Sampling and Analysis Plan for Mining Waste, RI/FS Tar Creek
Superfund Site, Ottawa County, Oklahoma. Prepared for US Army Corps of Engineers, Tulsa District, and
US EPA Region VI. Volumes I & II.
Brown, S., R. Chaney, J. Hallfrisch, J. A. Ryan, and W.R. Berti. 2004. In-situ Soil Treatment to Reduce the
Phyto-and Bioavailability of Lead, Zinc, and Cadmium. Journal of Environmental Quality. 33:522-531.
C.C. Johnson and Malhotra, P.C. 1999. Final Additional Site Evaluation Findings Report. Tar Creek NPL
Site, Oklahoma.
Cates, D 2003. Background concentrations for soils in Ottawa County, ODEQ Technical Memo, pp. 19.
Christenson, S.C., Parkhurst, D.L., and Fairchild, R.W. 1990. Geohydrology and water quality of the
Roubidoux Aquifer, northeastern Oklahoma. U.S. Geological Survey, Open-File Report 90-570, 110 p.
Clevener, T.E. 1992. Preliminary Study of Lead, Cadmium, and Zinc Contamination in the Southwest
Missouri Mining Region. Missouri Water Resources Research Center.
CH2M HILL, 1985. Draft Remedial Investigation, Existing Data Evaluation, Galena subsite, Cherokee
County Site, Kansas. CH2M-Hill and Ecology and Environment.
CH2M HILL and Ecology and Environment, 1986. Final Draft, Phase I Remedial Investigation Report, Air
Quality Supplement, Cherokee County, Galena subsite, Kansas.
CH2M HILL, 2006. Draft Final Human Health Risk Assessment, Tar Creek OU4, Ottawa County,
Oklahoma. Response Action Contract No. 68-W6-0025, Work Assignment No. 233-RKED-06JW, DCN
05-8225. October 2005.
Dames & Moore. 1993a. Final Draft: Remedial Investigation, Baxter Springs (OU3) and Treece (OU4)
Subsites, Cherokee County, Kansas, Superfund Site. For EPA Region VII.
Dames & Moore. 1993b. Final Draft Feasibility Study, Baxter Springs (OU3) and Treece (OU4) Subsites,
Cherokee County, Kansas, Superfund Site. For EPA Region VII.
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Dames & Moore. 1994. Residential Yard Assessment Report for Jasper County, Missouri and Cherokee
County, Kansas. Project No. 24436-003-019, 36 p.
Dames & Moore. 1995. Final Remedial Investigation: Neck/Alba, Snap, Oronoco/Duenweg, Joplin,
Thomas, Carl Junction, and Waco Designated Areas, Jasper County Site, Jasper County, Missouri. For
EPA Region VII.
Dames & Moore. 1997. Final Feasibility Study for the Ground Water Operable Unit (OU4) of the Jasper
County Site, Jasper County, Missouri. For EPA Region VII.
Ecology and Environmental, Inc. 1996. Data Evaluation Summary Report. Tar Creek Site. Site
Assessment/Risk Assessment, Ottawa County, Oklahoma. Prepared for EPA Region 6 (CERCLIS #
OKD908629844), 301 p.
Eisler, R. 1988. Lead hazards to fish, wildlife, and invertebrates: A synoptic review. U.S. Department of
the Interior. U.S. Fish & Wildlife Service, 134 p.
Emmett, W.W., 1980. A field calibration of the sediment-trapping characteristics of the Helley-Smith
bedload sampler, USGS Professional Paper 1139, pp. 44.
EMS. 1995. Joint Response to September 29, 1994 Information Request, Ottawa County, Oklahoma.
Environmental Management Services Company, Gary D. Uphoff Submitted to U.S. EPA Region VI, 113
P-
Frazier, T., 2002. Flood Maps From the National Flood Insurance Program- Ottawa County, OK;
Oklahoma Tax Commission, Oklahoma City, OK.
Harvey, E.J. 1980. Ground water in the Springfield-Salem plateaus of Southern Missouri and northern
Arkansas: U.S. Geological Survey Water-Resources Investigations 80-7, 50 p.
Hinrichs, Dave; Mark Doolan; and Chris Wienecke. 2003. Demonstration of Subaqueous Disposal of Mill
Waste. Electronic Presentation. May 2003.
Irwin, J.C. 1971. Survey of Environmental Contaminants Near Galena, KS. Kansas Department of Health,
Air Quality and Occupational Health Section.
Isern, E., 1943. Central milling. Engineering and mining Journal, Vol. 144, No. 11, pp. 93-101.
Lagerwerff, J.V, D.L. Brower, and G.T. Biersdorf. 1972. Accumulation of Cadmium, Copper, Lead and
Zinc in Soil and Vegetation in the Proximity of a Smelter. In: Trace Substances in Environmental health,
Vol. 6. University of Missouri, pp 71-78.
Lagerwerff, J.V. and D.L. Brower. 1975. Source determination of heavy metal contaminants in the soil of a
mine smelter. In: Trace Substances in Environmental Health, Vol. 9. University of Missouri, pp. 207-215.
Lead-Impacted Communities Relocation Assistance Trust (Trust). 2006. Minutes of meeting setting priority
guidelines. Pilcher, Oklahoma. August 22, 2006.
Luza, K.V. October 13, 2005; telecommunication.
Luza, K.V. 1986. Stability problems associated with abandoned underground mines in the Picher Field,
northeastern Oklahoma. Oklahoma Geological Survey Circular 88, 114 p.
Macfarlane, P.A., and L.R. Hathaway. 1987. The Hydrogeology and Chemical Quality of Ground Waters
from the Lower Paleozoic Aquifers in the Tri-State Region of Kansas, Missouri and Oklahoma. Kansas
Geol. Survey, Ground Water Series 9. Univ. of KS.
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Marcher, M.V., Kenny, J.F., and others. 1984. Hydrology of Area 40, Western Region, Interior Coal
ProvinceQ Kansas, Oklahoma and Missouri: U.S. Geological Survey Water-Resources Investigations
Open-File Report 83-266, 97 p.
McAteer, Mike. 2005. E-mail correspondence regarding OU2 institutional controls during December 2005.
McKnight, E.T., and Fischer, R.P. 1970. Geology and ore deposits of the Picher Field, Oklahoma and
Kansas: U.S. Geological Survey Professional Paper 588, 165 p.
Means, R.S. 2002. Heavy Construction Cost Data. 16th Edition.
Nairn, R. W. 2002. Summary Report: Beaver Creek Passive Treatment System Design. School of Civil
Engineering and Environmental Science, University of Oklahoma at Norman. Submitted to Tulsa District,
U.S. Army Corps of Engineers. November 11, 2002.
NewFields. 2003. Feasibility Study, Mine and Mill Waste Operable Unit, OU1, Jasper County Site, Jasper
County, Missouri. Completed under AOC Docket No. 91-F-0020. April 2003.
OCC. 2003a. Tar Creek Progress Report, Oklahoma Conservation Commission. February 10, 2003.
OCC. 2003b. Unpublished Cost Estimates for Remediation of the McNeely AML Project. Oklahoma
Conservation Commission. Obtained from ODEQ in November 2005.
Office of Senator Jim Inhofe. 2006. "Inhofe-Henry-Boren Announce Tar Creek Buyout." Press Release.
May 4, 2006.
Oklahoma Department of Environmental Quality (ODEQ). 2002. Consent Order. Bingham Sand & Gravel
Co. and Oklahoma Department of Environmental Quality. Case No. 02-352. November 2002.
Oklahoma Department of Environmental Quality (ODEQ), 2003. Oklahoma Plan for Tar Creek, Ottawa
County, OK. Obtained from the Oklahoma Department of Environmental Quality Web site.
Oklahoma Department of Environmental Quality (ODEQ). 2007a. Personal Communication from J.D.
Strong, Chief of Staff, Office of the Secretary of the Environment, Oklahoma City, Oklahoma to Sing Chia,
U.S. Environmental Protection Agency, Region 6. March 2007.
Oklahoma Department of Environmental Quality (ODEQ). 2007b. The State of Oklahoma's Proposed
Remedial Action Alternative for the Tar Creek Superfund Site. March 2007.
Oklahoma State Legislature. 2006. 10 OS Supp. 2005, Section 7602. Amendment to Lead Impacted
Communities Relocation Act (Section 1. Amendatory Section 2, Chapter 371, OSL 2004). May 2006.
OWRB. 1983. Tar Creek Field Investigation Task 1.2: Water Quality Characteristics of Seepage and
Runoff at Two Tailings Piles in the Picher Field, Ottawa County, Oklahoma. Oklahoma Water Resources
Board, Water Quality Division
Playton, S.J., Davis, R.E., and McClafin, R.G. 1980. Chemical quality of water in abandoned zinc mines in
northeastern Oklahoma and southeastern Kansas; Oklahoma Geological Survey Circular 82, 49 p.
Quapaw Tribe of Oklahoma. 2007. Proposed Remedial Action Alternative for the Tar Creek Superfund
Site. 2007.
Rantz et al., 1982. Measurement and computation of streamflow: Volume 1. Measurement of stage and
discharge: U.S. Geological Survey Prof. Paper 2175.
Reed, E.W., Schoff, S.L., and Branson, C.C. 1955. Ground-water resources of Ottawa County, Oklahoma:
Oklahoma Geological Survey, Bulletin 72, 203 p.
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Ruby, M.V., Davis, A., and Nicholson, 1994. 1994. In situ formation of lead phosphates in soils as a
method to immobilize lead. Environmental Science and Technology 28:646-654.
Ruby, M.V., R. Schoof, W. Brattin, M. Goldade, G. Post, M. Harnois, E.E. Mosby, S.W. Casteel, W. Berti,
M. Carpenter, D. Edwards, D. Cragin, and W. Chappell. 1999. Advances in evaluating the oral
bioavailability of inorganics in soil for use in human health risk assessment. Environmental Science and
Technology 33:3697-3705.
Ruhl, O., S.A. Allen, and S.P. Holt. 1949. Zinc-lead Ore Reserves of the Tri-State District, Missouri-
Kansas-Oklahoma. Bureau of Mines, RI # 4490.
SCS. 1964. Soil Survey, Ottawa County, Oklahoma. USDA Soil Conservation Service in Cooperation with
the Oklahoma Agricultural Experiment Station.
United States Bureau of Indian Affairs (BIA). 2001. Removal of Moratorium on Sale of Native American-
Owned Chat. August 22, 2001.
United States Bureau of Indian Affairs (BIA). 2005. Chat Sales Treatability Study Work Plan for the Sale
of Indian-Owned Chat within the Tar Creek Superfund Site, Ottawa, County, Oklahoma. Submitted on
Behalf of EPA Region 6. June 23, 2005.
United States Department of the Interior (DOI) and United States Environmental Protection Agency (EPA).
2005. Model Site Operations Plan Incorporating Chat Handling Guidance.
United States Environmental Protection Agency (EPA). 1988. Guidance for Conducting Remedial
Investigations and Feasibility Studies Under CERCLA. Office of Emergency and Remedial Response, U.S.
Environmental Protection Agency, Washington, D.C. EPA/540/G-89/004.
United States Environmental Protection Agency (EPA). 1989. Advancing the Use of Treatment
Technologies for Superfund Remedies. Office of Emergency and Remedial Response, U.S. Environmental
Protection Agency, Washington, D.C. OSWER Directive No. 9355.0-26.
United States Environmental Protection Agency (EPA). 1990a. National Oil and Hazardous Substances
Pollution Contingency Plan: Final Rule. Volume 55, No. 46, pp. 8666-8865. Promulgated under 40 CFR
Part 300.
United States Environmental Protection Agency (EPA). 1990b. The Feasibility Study: Detailed Analysis of
Remedial Action Alternatives. OSWER Directive 9355-3-01FS4. March 1990.
United States Environmental Protection Agency (EPA). 1992. Storm Water Management for Industrial
Activities, Developing Pollution Prevention Plans and Best Management Practices. Document No. EPA
832-R-92-006.
United States Environmental Protection Agency (EPA). 1995. Residential Sampling for Lead: Protocols for
Dust and Soil Sampling (Final Report). EPA Work Assignment 4-10(02), MRI Project No. 9803, March
29, 1995, pp. 43.
United States Environmental Protection Agency (EPA). 1996. The Role of Cost in the Superfund Remedy
Selection Process. OSWER Directive 9200.3-23FS. EPA 540/F-96/018. PB96-963245. September 1996.
United States Environmental Protection Agency (EPA). 1998. Hydrologic Evaluation of Landfill
Performance (HELP) Model, Version 3.07.
United States Environmental Protection Agency (EPA). 1999a. Presumptive Remedy for Metals-in-Soil
Sites. OSWER Directive 9355.0-72FS. EPA 540-F-98-054. September 1999.
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United States Environmental Protection Agency (EPA). 1999b. Interim Policy on the Use of Permanent
Relocations as Part of Superfund Remedial Actions. OSWER Directive 9355.0-7 IP. EPA 540F-98-033
PB98-963305. June 30, 1999.
United States Environmental Protection Agency (EPA). 1999d. A Guide to Preparing Superfund Proposed
Plans, Records of Decision, and Other Remedy Selection Decision Documents, OSWER 9200.1-23P at p.
3-9. July 1999.
United States Environmental Protection Agency (EPA). 2000a. A Guide to Developing and Documenting
Cost Estimates during the Feasibility Study. OSWER Directive 9355.0-75. EPA 540-R-00-002. July 2000.
United States Environmental Protection Agency (EPA). 2000b. Institutional Controls: A Site Manager's
Guide to Identifying Evaluating, and Selecting Institutional Controls at Superfund and RCRA Corrective
Action Cleanups. OSWER Directive 9355.0-74FS-P. EPA 540-F-00-005. September 2000.
United States Environmental Protection Agency (EPA). 2001. Reuse Assessments: A Tool to Implement
the Superfund Land Use Directive. Memo from Larry Reed, Acting Director of Office of Emergency
Response and Remedial Response to Superfund National Policy Managers. OSWER Directive 9355.7-06P.
June 4, 2001.
United States Environmental Protection Agency (EPA). 2002. Draft. Institutional Controls: A Guide to
Implementing, Monitoring, and Enforcing Institutional Controls at Superfund, Brownfields, Federal
Facility, UST and RCRA Corrective Action Cleanups. OSWER Directive xxxx.x-xxxx. EPA xxx-x-xxx.
December 2002.
United States Environmental Protection Agency (EPA). 2003a. Tar Creek Superfund Site, Ottawa County,
Oklahoma: Administrative Order on Consent and Attachment 1, Statement of Work for RI/FS for OU4
(CERCLA DOCKET No. 6-03-01), 51 p.
United States Environmental Protection Agency (EPA). 2003b. Map of Tar Creek OU #4 ("ou4.jpg"
attached with the Tar Creek OU4 AOC), ACS/EPA Region VI GIS Support Team (20030616JB05).
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Sites Handbook. EPA Publication 9285.7-50, pp. 74.
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Implementation at Superfund Sites. OSWER No. 9355.0-106. September 2004.
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of Work Template and Users' Guide. Office of Superfund Remediation and Technology Innovation.
OSWER 9230.0-108. August 2004
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United States Environmental Protection Agency (EPA). 2005b. Interim Data Report for Chat Placement Pilot
Study, Tar Creek Superfund Site, Ottawa County, Oklahoma Technical Direction Document Nos. 06-04-01-
0010/06-08-0008. Prepared by Weston Solutions, Inc., San Antonio, Texas. February 2005.
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Prepared by Weston Solutions, Inc. San Antonio, Texas, July 2006.
United States Environmental Protection Agency (EPA). 2006b. Risk Management Decision for Operable
Unit No. 4. Signed on April 18, 2006.
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United States Environmental Protection Agency (EPA), Region VII. 2006c. Draft Ecological Preliminary
Remediation Goals, Cherokee County Superfund Site. July 2006.
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Vol. 71, No. 64. July 18, 2007.
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Waste. June 2007.
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Tar Creek, Ottawa County, Oklahoma. Draft report by Caleb Cope and Mark F. Becker.
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6006. Title VI, Section 6018, Safe, Accountable, Flexible, and Efficient Transportation Equity Act of 2005
(Public Law 109-59).
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TWRI Book 9.
Wright, C.A. 1918. Mining and milling of lead and zinc ores in the Missouri-Kansas-Oklahoma Zinc
District. U.S. Bureau of Mines Bulletin 154, pp. 134.
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GLOSSARY OF TERMS
Administrative Record File - Contains those documents that form the basis for the selection of a response
action.
Antimonial Lead - Consists of a lead alloy containing about 5 percent antimony.
Applicable or Relevant and Appropriate Requirements (ARARs) - Cleanup standards, standards of control,
and other substantive requirements, criteria, or limitations promulgated under federal environmental or
state environmental or facility siting laws that specifically address hazardous substance, pollutant,
contaminant, remedial action, location, or other circumstance found at a CERCLA site. Only those state
standards that are identified by a state in a timely manner and that are more stringent than federal
requirements may be applicable.
Aquifer - A layer of permeable rock, sand, or gravel below the ground's surface that can supply usable
quantities of ground water to wells and springs. An aquifer can be a source of drinking water.
Best Management Practices (BMPs) - Best Management Practices are broadly defined by EPA under
Section 304 of the Clean Water Act (including its implementing regulations at 40 CFR § 122.44(k)) as
schedules of activities, prohibitions of practices, maintenance procedures, and other management practices
to prevent or reduce the pollution of water of the U.S. Best Management Practices also include treatment
requirements, operating procedures, and practices to control industrial site runoff, spillage or leaks, or
drainage from raw material storage piles, erosion controls, dust suppression methods, or air monitoring as
needed as determined by EPA for verification purpose. In general, BMPs components include:
• Controlling process water to avoid discharge to surface water during and up to a 25-year storm event.
• Constructing berms around mill ponds or surface impoundments capable of retaining water without
seepage.
• Developing contingency measures and response plans to address releases from source water, process
water, sediment and storm water.
• Controlling storm water runoff within the process areas, controlling soil erosion on-site, and
controlling drainage.
• Containment of stockpiles of chat to prevent spread of contaminated material.
• Dust mitigation to minimize dust generated from the processing of chat and on-site haul roads to
include wetting, mist curtains, and foam blankets.
• Air monitoring during chat processing, as needed as determined by EPA, to confirm air quality and
effectiveness of dust mitigation.
• Controlling releases from trucks hauling raw and/or processed chat off-site to prevent fugitive dust and
off-site tracking of contaminated soil to include covering truck loads of chat with tarps and washing
trucks prior to leaving the site and entering public roads to prevent tracking.
• Decontamination of personnel and equipment
• Access controls like fences and gates
Chat - waste materials that was formed in the course of milling operations employed to recover lead and
zinc from metal bearing ore minerals.
Chat Base - The area that was once occupied by a chat pile.
Chert - A very hard and resistant rock that occurs as nodules within the dolomites and limestones of the
Ozarks.
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Clinker - A waste from coal combustion. It is usually gray to dark gray in color. The size of the clinker
fragments seen at the former Ottawa smelter location varies from about one inch in diameter (pebbles) to
less than one tenth of an inch in diameter (fine sands). Clinker has a honeycomb (pumiceous) texture and
thus is much less dense than slag or native rock material.
Consolidated Deposit - A consolidated deposit is defined as an agglomeration of materials that are
temporarily placed or consolidated prior to being put to some beneficial use or in preparation for transport
or final disposal.
Development rock - the waste rock generated in drilling shafts to the deep mines.
Distal Areas - Areas that are generally located outside the high density mining areas and include rural areas
as shown in Figure 3.
Ecological Risk Assessment - A process that evaluates the likelihood that adverse ecological effects may
occur or are occurring as a result of exposure to one or more chemical, physical, or biological stressors.
Fine Tailings - Sand-like tailings from mining, milling processes including chat washing and flotation
processes. Generally these fine tailings are found in tailings ponds.
Feasibility Study - A study undertaken by the lead agency to develop and evaluate options for remedial
action. The Feasibility Study emphasizes data analysis and is generally performed concurrently and in an
interactive fashion with the remedial investigation, using data gathered during the RI.
Floodplain - Areas inundated by a flood with a return interval of 100 years
Flux - A variety of materials used to purify metals or prevent undue oxidation of molten metal surfaces.
Gangue materials - Impurities including sand and rock that surrounds the mineral of interest in an ore.
Ground Water - Water found beneath the ground surface that fills pores between soil, sand, and gravel
particles to the point of saturation. When it occurs in a sufficient quantity, ground water can be used as a
water supply.
Hazard Quotient or Index - Non-cancer "risks" are described as a number called the hazard quotient (or
hazard index for multiple chemicals), which is a ratio of the actual chemical dose to the Reference Dose.
For ecological risk assessment, this ratio is exposure concentration or dose divided by the ecological
toxicity values. A hazard quotient of one or less is considered protective.
Human Health Risk Assessment - At Superfund sites, human health risk is the chance that chemicals from a
site will cause health problems. A risk assessment answers four basic questions: is there a risk, who is at
risk, how great is the risk, and what is causing the risk.
In-Stream Source Material - Source material accumulations located within the streambed of flowing
streams including intermittently (e.g., seasonal) flowing streams.
Institutional Controls (IC) - Administrative and/or legal mechanisms that: (1) help minimize the potential
for human exposure to contamination, and (2) protect the integrity of the remedy. ICs accomplish these
objectives by directly limiting land or resource use, and/or by providing information that modifies
behavior.
Maximum Contaminant Level (MCL) - Maximum permissible level of a contaminant in water that is
delivered to any user of a public water system.
Microgram per Deciliter (|ig/dL) - Units of measure used to express the concentrations of lead in blood. As
an example, one ng/dL of lead would be equivalent to one drop in 18,800 gallons.
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National Priority List (NPL) - The NPL means the list, compiled by EPA pursuant to CERCLA section
105, of uncontrolled hazardous substance releases in the United States that are priorities for long-term
remedial evaluation and response.
Native Soils - soil that was present prior to the start of mining operations at the Site and is generally free
from Source Materials. The most common native soil series that is present within the Site is the Taloka silt
loam, however, other soil series may exist.
Near-Stream Source Material - Source material accumulations located within the active floodways of
perennial streams and major tributaries. Near-stream source materials consists of deposits that are subject
to stream erosion during flooding events and may also include sources of out-washing chat or chat seepage
that are capable of being transported to and deposited in perennial streams and major tributaries by surface
water. These source materials may act as significant surface water loading sources. This category does not
include bed or bank sediments that have already been deposited in streams.
Operable Unit - A discrete aspect of a Superfund Site defined by EPA. The cleanup of a site can be divided
into a number of operable units, depending on the complexity of the problems associated with the site.
Operable Unit 4 (OU4) - Operable Unit 4 means the portion of the Tar Creek Superfund Site that occupies
approximately 40 square miles in the northern portion of Ottawa County, Oklahoma, and is generally
depicted in Figure 1. OU4 includes the parts of the Site (both urban and rural) that are not currently used
for residential purposes or which are sparsely used for residential purposes, where mine and mill wastes
and smelter waste have been deposited, stored, disposed of, placed, or otherwise come to be located. Areas
where such material has come to be located will include without limitation chat covered haul roads and
non-operating railroad grades. OU4 includes residential yards located in Ottawa County outside of city or
town limits except for those residential yards that have been addressed under OU2. . OU4 includes areas
where mine and mill wastes and smelter wastes have been moved by anthropogenic activities (e.g., where
chat has been used as a driveway or fill in a rural area) or by natural actions including erosion (e.g., where
chat has washed from a chat pile into a stream). OU4 generally does not include sediment, except where
sediment is incidentally addressed when chat is removed from in-stream or near-stream areas. OU4 does
not include ground water or surface water, except indirectly in that the remedial action for OU4 will
eliminate some of the sources of ground water and surface water contamination. OU4 does not include
contamination in streams that is due to mine drainage. OU4 includes all suitable areas in very close
proximity to the contamination necessary for implementation of the response action. OU4 also includes
Site areas selected for repositories for the disposal of source materials and contaminated soils and
sediments. Notwithstanding the preceding provisions of this OU4 definition, OU4 also includes residences
and businesses in areas targeted for relocation including residences in Picher, Cardin and Hockerville. The
areas targeted for relocation are generally described on the Map that is attached as Figure 9.
Opportunistic Sampling - Collecting surface samples of identified smelter wastes that is scattered and in
limited amounts at the site.
Organic Matter - Any type of natural composted or non-composted plant materials, animal manures, or
sewage sludge that are used in applications that amend and stabilize soils, mulching, creating anaerobic
treatment systems, and other remedial actions. Biosolids, poultry litter, spent mushroom compost, cow
manure, hay, yard wastes, wood chips, saw dust, or other similar materials are all examples of organic
matter that fall under this generic term.
Overburden - material overlying a useful mineral deposit that is removed to reach the mineral deposit.
Potentially Responsible Parties (PRP) - Any individual or company, including owners, operators,
transporters or generators, potentially responsible for, or contributing to a spill or other contamination at a
Superfund site.
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Parts Per Million (ppm): mg/kg; mg/L - Units of measure used to express concentrations of contaminants.
The concentration of contaminates in soil is expressed as mg/kg. The concentration of contaminates in
water is expressed as mg/L. One pm is equal to one mg/kg or one
mg/L. As an example, one ounce of benzene in one million ounces of water is 1 ppm of benzene.
Record of Decision (ROD) - A public document that explains which cleanup alternative(s) will be used at a
Superfund site.
Remedial Investigation (RI) - An investigation that determines the nature and extent of contamination at the
Site. The scope of an RI can vary widely from a small specific activity to a complex study. The next step
following an RI is a Feasibility Study.
Rubble - A mass or stratum of fragments or rock, brick and concrete blocks, scrap metal and retort
remnants.
Screening Level - A risk-based concentration used to compare preliminary investigation data for an initial
evaluation of the environmental concern at a site. A chemical concentration larger than the screening value
should be evaluated more carefully for potential risk.
Site - The Oklahoma portion of the Tri-State Mining District that consist of the areas of Ottawa County
impacted by mining waste. The Site includes all of the area (approximately 40 square miles) in northern
Ottawa County where lead and zinc mining operations were conducted and any area where a hazardous
substance from mining or milling in Ottawa County has been stored or disposed. The Site also includes all
suitable areas in very close proximity to the contamination necessary for implementation of the response
action. The Site is bounded by the State of Kansas to the north. The principal Site communities include
Cardin, Commerce, North Miami, Picher, and Quapaw.
Slag - A material composed of the oxides of gangue materials produced by gravity separation from molten
metals during the smelting operations. It is dark gray to black in color. It is very dense compared to
clinker or native rock material and usually has a molten appearance (amorphous).
Smelter-Affected Soils - Soils occuring within about 500 feet of the Site's only known smelter, the Ottawa
Smelter located near Hockerville, Oklahoma.
Smelter Waste - Smelter-related waste materials and materials that were piled near the smelter, including
slag (the oxides of gangue materials produced by gravity separation from molten metals), clinker (boiler
residue), and flux (flux is a Si-Al-CaO composite, an additive used to separate iron from sulfides).
Soil Amendment - A generic term similar to organic matter that refers to a wide variety of organic and non-
organic materials used for fertilizing, stabilizing, or improving the physical or chemical composition of
soils. Soil amendments are typically used to create favorable conditions for plant growth or revegetating
disturbed sites.
Soil Cover - This term defines a soil cap consisting of topsoil and subsoil layers designed to sustain a
permanent vegetative cover under local climatic and physiographic conditions. The soil covers described in
the Feasibility Study Report assume 12 inches of agronomic soils plus 12 inches of clayey soils for cost
estimating purposes with placement to prevent erosion, promote evapotranspiration, and reduce, but not
eliminate infiltration. The actual thickness of the soil cover will be determined in an engineering design,
but would include a minimum of 12 inches total thickness.
Source Material - Smelter waste, and mine and mill waste including chat, fines, overburden, development
rock, and other tailings. Source materials are generally found in chat piles, chat bases, and tailings ponds.
Tailings - Refuse or dross remaining after ore has been processed.
-------
Record of Decision
Tar Creek OU4 Superfund Site
Page 111
February 2007
Tailing ponds - Areas that were once used for the disposal of water containing mine and mill waste,
generally fines from the flotation process or fines from chat washing. Many of these tailings ponds are now
dry or partially dry, and the mine and mill waste is left behind. Tailings ponds are also referred to as wash
ponds, flotation ponds, slime ponds, and mill ponds.
To Be Considered - Consists of advisories, criteria, or guidance that were developed by EPA, other federal
agencies, or states that may be useful in developing CERCLA remedies.
Transition zone soil - the soil found around and under the chat piles, chat bases, or tailings ponds extending
outward from the piles or ponds.
Uniform Relocation Act - The Uniform Relocation Assistance and Real Property Acquisition Policies for
Federal and Federally Assisted Programs. 42 U.S.C Section 61, is the law that governs relocation of
displaced persons when the Federal government is involved.
-------
Appendix A
ODEQ Concurrence Letter
-------
¦ w . ino.c«_i iuii uivi&iuN * oy84104109912146657330 NO.020 D002
STEVEN A. THOMPSON
Executive Director
OKLAHOMA
CftriTHtNT O? CNV)tC?Mft!H?U WAimr
OKLAHOMA DEPARTMENT OF ENVIRONMENTAL QUALITY
BRAO HENRY
Governor
February 19,2008
Sam Coleman (6SF-D), P.E., Director
Superfund Division
U.S. Environmental Protection Agency
1445 Ross Avenue, Suite 1200
Dallas, Texas 75202-2733
Dear Mr. Coleman:
The Oklahoma Department of Environmental Quality (DEQ) concurs with and supports
the Record of Decision for the Tar Creek Superfund Site Operable Unit 4. Our
concurrence is based upon the most recent version of the Draft Record of Decision which
you provided to us on February 15, 2008. The DEQ believes that the proposed remedy
for Operable Unit 4 of the Tar Creek Superfund Site will provide long-term protection for
public health and die environment.
The DEQ looks forward to our continued cooperative effort with the Region VI Office of
the U.S. Environmental Protection Agency and the Quapaw Tribe as we proceed through
Remedial Design and Remedial Action.
Sincerely,
Steven A. Thompson
Executive Director
707 NORTH ROBINSON, P.O. BOX 1677, OKLAHOMA CITY, OKLAHOMA 73101-1677
Cfintad oo recycled p»Por with say ink
o
-------
Appendix B
Administrative Record Index
-------
T reece
Picher
Cardin
Commerce
North Miami
Miami
Baxter Springs
Figure 1
|l "" } OU 4 Boundary
-------
-------
Legend
-------
Source
Materials
Primary
Transport
Mechanisms
Affected
Media
Figure 4 Source Materials, Transport Mechanisms, and Affected Media
-------
Primary
Source
Chat Pile /
Mill Pond
Direct
Contact
T ransport
Bio-
accumulation
Plant Uptake
Leaching
Secondary
Source
Surface
Runoff
Surface Soil
Animal
Tissue
Plant Tissue
Surface
Water/
Sediment
Release
Mechanism
2
Secondary
Source
Groundwater
Direct
Contact
Biotransfer
Bio-
accumulation
Fish/Aquatic
Organisms
Tissue
Source
Materials
Surface Soil
Indoor Dust
Indoor Dust
Particulate
Emission
Ambient Air
Ambient Air
Animal
Tissue
Milk (Dairy)
Milk (Dairy)
Plant
Tissue
Fish/Aquatic
Organisms
Tissue
Groundwater
(shallow well)
Exposure
Route
Potential
Receptor
Ingestion
Recreator
Dermal
Ingestion
Resident
(RGP, SR)
Dermal
Inhalation
Resident
(RGP, SR)
Ingestion
Resident
(RGP, SR)
Ingestion
Resident
(RGP, SR)
Ingestion
Resident
(RGP, SR)
Ingestion
Recreator
Dermal
Ingestion
Resident
(RGP, SR)
Ingestion
Resident
(RGP, SR)
SR - Subsistence Resident
RGP - Rural General Public
Conceptual Site Model for HHRA
Tar Creek OU4, Miami, OK
Figure 5
-------
Figure 6. Conceptual Site Model and Terrestrial Endpoints Evaluated under OU4
Tar Creek Site
Ottawa County, Oklahoma
1 Chemical Source 1 Mech^sm 1 Medium 1 1 Ensure Route 1 Terrestrid Endpoints - Sumvd, Growth, or Reproduction of
Community
pi.,,
Herbivores
Omnivores
Carmv
Invertivores
Rscivor
white-tailed deer
muskrat
song sparrow
white-footed mouse
b o'bcat P
short-tailed shrew
gray b at
American robin
Wilson's snipe
mZ P
green heron
mglston'
O
o
o
O
O
O
o
O
o
O
O
O
| char piles |
dietarv transfer
o
O
O
O
o
O
o
o
O
H - H - b
H Towc^ea" 1 H inMaa°n 1 - 1 - 1 " 1 " 1 " 1 " 1 " 1 " 1 " 1 " 1 " 1 " 1 " 1 " 1 " 1 " 1 " 1
1 mine/mill residues, mill ponds J—
O
o
—~j leaching | -
—>| water
seeps |—
3 1—
ingestion
o
o
o
o
o
o
o
o
o
o
water erosion | ninoff |
H ¦— 1—
mfelhon
o
O
o
o
o
O
O
dietary transfer
o
o
o
o
O
o
1 trans.tionzoneso.ls |J
—m surface water P
Sitet!!
o
o
o
o
o
o
o
o
o
o
O
o
o
O
O
OU Operational unit
| - | Pathway not complete or applicable, no evaluation necessary
| " | Pathway is or may be complete, however, risk is likely low Pathway not evaluated in Ecological Risk Assessment
| Q | Pathway is complete and risk may be significant Pathway evaluated in Ecological Risk Assessment
022-DFR-l 0282005
-------
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i ' * * -• ; =
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5-T28N-R24E
J
Low Intensity Residential
^ High Intensity Residential
(j Commercial/Industrial/Transportation
Bare Rock/Sand/Clay
\ATA INTERNATIONAL, INC.
Fort Collins, Colorado, USA
Tar Creek OU4
USGS Land Use Surface Feature Map
t Grasslands/Herbaceous
1 Pasture/Hay
Quarries/Strip Mines/Gravel Pits
Deciduous Porests
Evergreen Forest
Mixed Forests
Shrubland
Woody Wetlands
Emergent Herbaceous Wetlands
I Row Crops
I Small Grains
Urban/Recreational
Lakes, Ponds, and Rivers
Q Site Boundary
1
2 Miles
_l
-------
-------
Legend
j Site Boundary
! _ J C'ty Boundaries
Relocation Assistance Boundary
Adopted by the Lead-Impacted Communities Relocation
Assistance Trust on August 1, 2006
Feet
0
2,500 5,000
10,000
Figure: 9
Relocation Assistance Zone
Operable Unit 4
-------
LEGEND
——— OU 4 Streams
Edge Needing Possible Control
Near Stream Chat Pile or Chat Base
IN
A
I Feet
500
1,000
2,000
Figure 10
Estimated Source and
Seepage Control Locations
Operable Unit 4
-------
-------
Table 1
Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations (EPCs)
Scenario Timeframe: Current/Future
Medium: Chat and Tailings Material
Exposure Medium: Chat and Tailings
Concentrations
Frequency of
EPC
Exposure Point
COCs
Min
Max
Units
Detection
EPC
Basis
Surface Material (0-6
inches)
Lead
175
39600
mg/kg
97/97
3461
Mean
Scenario Timeframe:
Medium:
Exposure Medium:
Current/Future
Surface Soil (residential,
Animal Tissue
rural areas,
and transition zone)
Concentrations
Frequency of
EPC
Exposure Point
COCs
Min
Max
Units
Detection
EPC
Basis
Surface Soil (residential,
rural areas, and
transition zone)
Cadmium
Lead
0.5
10.5
248
4450
mg/kg
mg/kg
249/261
316/317
27.4
441
97.5%
97.5%
Zinc
38
39200
mg/kg
260/261
5390
97.5%
Scenario Timeframe:
Medium:
Exposure Medium:
Current
Surface Soil (General Public)
Surface Soil
Concentrations
Frequency of
EPC
Exposure Point
COCs
Min
Max
Units
Detection
EPC
Basis
Surface Soil (0-1 inch) in
Yards owned by the
General Public
Cadmium
Lead
0.5
10.9
47.5
822
mg/kg
mg/kg
164/172
171/172
47.5
(1)
Max
Zinc
38
7700
mg/kg
171/172
7700
Max
(1) concentration at the individual yard was used as EPC.
Scenario Timeframe:
Medium:
Exposure Medium:
Current
Chat Pile Material and Tailings
Ambient Air
Concentrations
Frequency of
EPC
Exposure Point
COCs
Min
Max
Units
Detection
EPC
Basis
Ambient Air
Cadmium
0.000002
0.00020
ug/m3
-
0.00008
99%
Zinc
0.00075
0.043
ug/m3
—
0.017
99%
Scenario Timeframe: Current
Medium: Surface Soil (Subsistence)
Exposure Medium: Surface Soil
Concentrations
Frequency of
EPC
Exposure Point
COCs
Min
Max
Units
Detection
EPC
Basis
Surface Soil (0-1 inch) in
Cadmium
0.6
9.6
mg/kg
6/9
9.6
Max
Yards at Native
American-owned
Lead
26.6
135
mg/kg
9/9
(1)
property
Zinc
47
1940
mg/kg
9/9
1940
Max
(1) concentration at the individual yard was used as EPC.
-------
Table 1
Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations (EPCs)
Scenario Timeframe:
Medium:
Exposure Medium:
Current/Future
Groundwater
Groundwater
Concentrations
Frequency of
EPC
Exposure Point
COCs
Min
Max
Units
Detection
EPC
Basis
Private Wells at
properties owned by the
General Public
Cadmium
0.0001
0.003
mg/L
16/25
0.003
Max
Zinc
0.02
1.11
mg/L
22/25
1.11
Max
(2) concentration at the individual well was used as EPC.
Scenario Timeframe:
Medium:
Exposure Medium:
Current/Future
Groundwater
Groundwater
Exposure Point
COCs
Concentrations
Min
Max
Units
Frequency of
Detection
EPC
EPC
Basis
Private Wells at
properties at Native
American-owned
property
Zinc
0.19
0.22
mg/L
2/3
0.22
Max
Scenario Timeframe: Current
Medium: Transition Zone Soil
Exposure Medium: Asparagus (Above Ground)
Concentrations
Frequency of
EPC
Exposure Point
COCs
Min
Max
Units
Detection
EPC
Basis
Asparagus (above-
Cadmium
0.6707
21.333
mg/kg
19/19
5.48
95%
ground portion),
unwashed plant
Lead
0.447
62.01
mg/kg
19/19
18.8
Mean
Zinc
23.3758
409.5
mg/kg
19/19
142
95%
Scenario Timeframe: Current
Medium: Transition Zone Soil
Exposure Medium: Asparagus (Root)
Concentrations
Frequency of
EPC
Exposure Point
COCs
Min
Max
Units
Detection
EPC
Basis
Asparagus (root
Cadmium
4.4243
25.915
mg/kg
19/19
12.5
95%
portion), unwashed plant
Lead
19.5048
1387.44
mg/kg
19/19
558
Mean
Zinc
234.107
3578.58
mg/kg
19/19
1400
95%
Scenario Timeframe: Current
Medium: Transition Zone Soil
Exposure Medium: Willow (Above Ground)
Concentrations
Frequency of
EPC
Exposure Point
COCs
Min
Max
Units
Detection
EPC
Basis
Willow (above-ground
Cadmium
1.1515
32.2588
mg/kg
19/19
17.8
95%
portion), unwashed plant
Lead
0.5226
20.213
mg/kg
17/19
10.9
Mean
Zinc
67.445
705.55
mg/kg
19/19
467
95%
-------
Table 1
Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations (EPCs)
Scenario Timeframe: Current
Medium: Transition Zone Soil
Exposure Medium: Willow (Root)
Concentrations
Frequency of
EPC
Exposure Point
COCs
Min
Max
Units
Detection
EPC
Basis
Willow (root portion),
Cadmium
4.8909
132.818
mg/kg
19/19
49.7
95%
unwashed plant
Lead
15.8912
1922.46
mg/kg
19/19
1024
Mean
Zinc
466.04
13202
mg/kg
19/19
4620
95%
Scenario Timeframe: Current
Medium: Transition Zone Soil
Exposure Medium: Cattail (Above Ground)
Concentrations
Frequency of
EPC
Exposure Point
COCs
Min
Max
Units
Detection
EPC
Basis
Cattail (above-ground
Cadmium
0.02755
34.17
mg/kg
14/19
19.8
99%
portion), unwashed plant
stalk
Lead
0.29
1366.8
mg/kg
17/19
287
Mean
Zinc
13.9518
4411.5
mg/kg
19/19
2560
99%
Scenario Timeframe: Current
Medium: Transition Zone Soil
Exposure Medium: Cattail (Root)
Concentrations
Frequency of
EPC
Exposure Point
COCs
Min
Max
Units
Detection
EPC
Basis
Cattail (root portion),
Cadmium
0.04185
249.426
mg/kg
19/19
61.1
95%
unwashed plant
Lead
0.8601
2759.77
mg/kg
19/19
1076
Mean
Zinc
17.825
18414
mg/kg
19/19
4360
95%
-------
Table 2
Summary of General Public Resident Exposure Parameters based on Reasonable Maximum Exposure.
Exposure Point
Exposure
Route
Parameter
Code
Parameter Definition
Units
Resident (General Public)
Adult
Child
Surface Soil
(0-1 inch)
Ingestion
CS
Chemical Concentration in Soil
mg/kg
Chemical-specific
Chemical-specific
IR-S
Ingestion Rate of Soil
mg/day
100
200 t
EF
Exposure Frequency
days/year
350
350
ED
Exposure Duration
years
24
6t
CF1
Conversion Factor 1
kg/mg
1.0E-06
1.0E-06
BW
Body Weight
kg
70
15 t
AT-N
Averaging Time (Non-Cancer)
days
8,760
2,190
AT-C
Averaging Time (Cancer)
days
25,550
-
IR-S-Adj
Ingestion Rate of Soil, Age-adjusted f
mg-year/kg-day
114.29
-
Dermal
CS
Chemical Concentration in Soil
mg/kg
Chemical-specific
Chemical-specific
SA
Skin Surface Area Available for Contact
cm2
5,700
2,800 t
SSAF
Soil to Skin Adherence Factor
mg/cm2-day
0.07
0.2 t
DABS
Dermal Absorption Factor Solids
-
Chemical-specific
Chemical-specific
CF1
Conversion Factor 1
kg/mg
1.0E-06
1.0E-06
EF
Exposure Frequency
days/year
350
350
ED
Exposure Duration
years
24
6t
BW
Body Weight
kg
70
15 t
AT-N
Averaging Time (Non-Cancer)
days
8,760
2,190
AT-C
Averaging Time (Cancer)
days
25,550
-
DA-Adj
Dermal Absorption, Age-adjusted f
mg-year/kg-day
361
-
Private Wells
Ingestion
CW
Chemical Concentration in Water
Mg/i
Chemical-specific
Chemical-specific
IR-W
Ingestion Rate of Water
liters/day
2
1 t
EF
Exposure Frequency
days/year
350
350
ED
Exposure Duration
years
24
6t
CF2
Conversion Factor 2
mg/pg
1.0E-03
1.0E-03
BW
Body Weight
kg
70
15 t
AT-N
Averaging Time (Non-Cancer)
days
8,760
2,190
AT-C
Averaging Time (Cancer)
days
25,550
-
IR-W-Adj
Ingestion Rate of Water, Age-adjusted f
liter-year/kg-day
1.1
-
Ambient Air
Inhalation
CA
Chemical Concentration in Air
mg/m3
Chemical-specific
Chemical-specific
IN
Inhalation Rate
m3/day
20
10f
EF
Exposure Frequency
days/year
350
350
ED
Exposure Duration
years
24
6t
BW
Body Weight
kg
70
15 t
AT-N
Averaging Time (Non-Cancer)
days
8,760
2,190
AT-C
Averaging Time (Cancer)
days
25,550
-
IN-Adj
Inhalation Rate, Age-adjusted f
m3/hour
10.9
-
Note:
t Child exposure factors were used to calculate age-adjusted exposure values.
-------
Table 3
Summary of Subsistence Resident Exposure Parameters based on Reasonable Maximum Exposure.
Exposure Point
Exposure
Route
Parameter
Code
Parameter Definition
Units
Resident (Subsistence)
Adult
Child
Surface Soil
(0-1 inch)
Ingestion
CS
Chemical Concentration in Soil
mg/kg
Chemical-specific
Chemical-specific
IR-S
Ingestion Rate of Soil
mg/day
400
400 |
EF
Exposure Frequency
days/year
365
365
ED
Exposure Duration
years
70
6t
CF1
Conversion Factor 1
kg/mg
1.0E-06
1.0E-06
BW
Body Weight
kg
70
15|
AT-N
Averaging Time (Non-Cancer)
days
25,550
2,190
AT-C
Averaging Time (Cancer)
days
25,550
-
IR-S-Adj
Ingestion Rate of Soil, Age-adjusted f
mg-year/kg-day
526
-
Dermal
CS
Chemical Concentration in Soil
mg/kg
Chemical-specific
Chemical-specific
SA
Skin Surface Area Available for Contact
cm2
5,700
2,800 |
SSAF
Soil to Skin Adherence Factor
mg/cm2-day
0.07
0.2 |
DABS
Dermal Absorption Factor Solids
-
Chemical-specific
Chemical-specific
CF1
Conversion Factor 1
kg/mg
1.0E-06
1.0E-06
EF
Exposure Frequency
days/year
365
365
ED
Exposure Duration
years
70
6t
BW
Body Weight
kg
70
15|
AT-N
Averaging Time (Non-Cancer)
days
25,550
2,190
AT-C
Averaging Time (Cancer)
days
25,550
-
DA-Adj
Dermal Absorption, Age-adjusted f
mg-year/kg-day
589
-
Small Game
(Bird, Rabbit)
Ingestion
CS
Chemical Concentration in Soil
mg/kg
Chemical-specific
-
BAF-SMG
Bio-accumulation Factor-Small Game
kg/kg
Chemical-specific
-
IR-SMG
Ingestion Rate -Small Game
kg/day
0.05
-
EF
Exposure Frequency
days/year
365
-
ED
Exposure Duration
years
70
-
BW
Body Weight
kg
70
-
AT-N
Averaging Time (Non-Cancer)
days
25,550
-
AT-C
Averaging Time (Cancer)
days
25,550
-
Beef
(Cattle)
Ingestion
^beef
Chemical Concentration in Beef
mg/kg
Chemical-specific
-
BAF-BEEF
Bio-accumulation Factor - Beef
kg/kg
Chemical-specific
-
IR-BEEF
Ingestion Rate - Beef
kg/day
F: 0.1; B: 0.885
-
EF
Exposure Frequency
days/year
365
-
ED
Exposure Duration
years
70
-
BW
Body Weight
kg
70
-
AT-N
Averaging Time (Non-Cancer)
days
25,550
-
AT-C
Averaging Time (Cancer)
days
25,550
-
Milk (Dairy)
Ingestion
C-DM
Chemical Concentration in Milk (Dairy)
Mg/i
-
Chemical-specific
IR-DM
Ingestion Rate of Milk (Dairy)
liters/day
-
0.5
EF
Exposure Frequency
days/year
-
365
ED
Exposure Duration
years
-
6
CF2
Conversion Factor 2
mg/|jg
-
1.0E-03
BW
Body Weight
kg
-
15
AT-N
Averaging Time (Non-Cancer)
days
-
2,190
AT-C
Averaging Time (Cancer)
days
-
25,550
Ambient Air
Inhalation
CA
Chemical Concentration in Air
mg/m3
Chemical-specific
Chemical-specific
IN
Inhalation Rate
m3/day
30
10 |
EF
Exposure Frequency
days/year
365
365
ED
Exposure Duration
years
70
6t
BW
Body Weight
kg
70
15|
AT-N
Averaging Time (Non-Cancer)
days
25,550
2,190
AT-C
Averaging Time (Cancer)
days
25,550
-
IN-Adj
Inhalation Rate, Age-adjusted f
m3/hour
31.4
-
-------
Table 3
Summary of Subsistence Resident Exposure Parameters based on Reasonable Maximum Exposure.
Exposure Point
Exposure
Route
Parameter
Code
Parameter Definition
Units
Resident (Subsistence)
Adult
Child
Private Wells
Ingestion
CW
Chemical Concentration in Water
Mg/i
Chemical-specific
Chemical-specific
IR-W
Ingestion Rate of Water
liters/day
4
1 t
EF
Exposure Frequency
days/year
365
365
ED
Exposure Duration
years
70
6t
CF2
Conversion Factor 2
mg/|jg
1.0E-03
1.0E-03
BW
Body Weight
kg
70
15|
AT-N
Averaging Time (Non-Cancer)
days
25,550
2,190
AT-C
Averaging Time (Cancer)
days
25,550
25,550
IR-W-Ad j
Ingestion Rate of Water, Age-adjusted f
liter-year/kg-day
4.1
-
Fish Tissue
Ingestion
Qish
Chemical Concentration in Fish Tissue
mg/kg-fish
Chemical-specific
-
IR-F
Fish Ingestion Rate
kg-fish/day
F: 0.885; B: 0.075
-
EF
Exposure Frequency
days/year
365
-
ED
Exposure Duration
years
70
-
BW
Body Weight
kg
70
-
AT-N
Averaging Time (Non-Cancer)
days
25,550
-
AT-C
Averaging Time (Cancer)
days
25,550
-
Aquatic Food
Tissue
(Mussels etc.)
Ingestion
Csed
Chemical Concentration in Sediment
mg/kg-sed
Chemical-specific
-
BAF-AI
Bio-accumulation Factor (Aquatic Invertebrates)
kg/kg-tissue
Chemical-specific
-
IR-AF
Aquatic Food (Mussels, Crayfish) Ingestion Rate
kg-food/day
0.175
-
EF
Exposure Frequency
days/year
365
-
ED
Exposure Duration
years
70
-
BW
Body Weight
kg
70
-
AT-N
Averaging Time (Non-Cancer)
days
25,550
-
AT-C
Averaging Time (Cancer)
days
25,550
-
Asparagus
Ingestion
Cplantl
Chemical Concentration in Asparagus (above ground)
mg/kg
Chemical-specific
-
Cplant1-root
Chemical Concentration in Asparagus (root).
mg/kg
Chemical-specific
-
IR-P1
Ingestion Rate -Asparagus (above ground)
kg/day
0.27
-
IR-P1root
Ingestion Rate -Asparagus (root)
kg/day
0.27
-
EF
Exposure Frequency
days/year
365
-
ED
Exposure Duration
years
70
-
BW
Body Weight
kg
70
-
AT-N
Averaging Time (Non-Cancer)
days
25,550
-
AT-C
Averaging Time (Cancer)
days
25,550
-
Willow
Ingestion
Cplant2
Chemical Concentration in Willow (above ground)
mg/kg
Chemical-specific
-
Cpiant2-root
Chemical Concentration in Willow (root).
mg/kg
Chemical-specific
-
IR-P2
Ingestion Rate -Willow (above ground)
kg/day
0.27
-
IR-P2root
Ingestion Rate -Willow (root)
kg/day
0.27
-
EF
Exposure Frequency
days/year
365
-
ED
Exposure Duration
years
70
-
BW
Body Weight
kg
70
-
AT-N
Averaging Time (Non-Cancer)
days
25,550
-
AT-C
Averaging Time (Cancer)
days
25,550
-
Cattail
Ingestion
Cplant3
Chemical Concentration in Cattail (above ground)
mg/kg
Chemical-specific
-
Cpiant3-root
Chemical Concentration in Cattail (root).
mg/kg
Chemical-specific
-
IR-P3
Ingestion Rate -Cattail (above ground)
kg/day
0.27
-
IR-P3root
Ingestion Rate -Cattail (root)
kg/day
0.27
-
EF
Exposure Frequency
days/year
365
-
ED
Exposure Duration
years
70
-
BW
Body Weight
kg
70
-
AT-N
Averaging Time (Non-Cancer)
days
25,550
-
AT-C
Averaging Time (Cancer)
days
25,550
-
Note:
F - high fish diet; B - high beef diet
t Child exposure factors were used to calculate age-adjusted exposure values.
-------
Table 4
Summary of Adolescent Recreator Exposure Parameters based on Reasonable Maximum Exposure.
Exposure Point
Exposure
Parameter
Parameter Definition
Units
Recreator
Route
Code
Adolescent
Chat Pile &
Ingestion
CM
Chemical Concentration in Material
mg/kg
Chemical-specific
Tailings Ponds
IR-S
Ingestion Rate of Material
mg/day
100
Surface (0-6 inch)
EF
Exposure Frequency
days/year
184
ED
Exposure Duration
years
11
CF1
Conversion Factor 1
kg/mg
1.0E-06
BW
Body Weight
kg
47
AT-C
Averaging Time (Cancer)
days
25,550
AT-N
Averaging Time (Non-Cancer)
days
4,015
Dermal
CM
Chemical Concentration in Material
mg/kg
Chemical-specific
SA
Skin Surface Area Available for Contact
cm2
5,300
SSAF
Soil to Skin Adherence Factor
mg/cm2-day
0.07
DABS
Dermal Absorption Factor Solids
-
Chemical-specific
CF1
Conversion Factor 1
kg/mg
1.0E-06
EF
Exposure Frequency
days/year
184
ED
Exposure Duration
years
11
BW
Body Weight
kg
47
AT-C
Averaging Time (Cancer)
days
25,550
AT-N
Averaging Time (Non-Cancer)
days
4,015
-------
Table 5
Cancer Toxicity Data Summary
Pathway: Ingestion, Dermal
Chemical
of
Concern
Oral Cancer
Slope Factor
Dermal Cancer
Slope Factor
Slope Factor
Units
Weight of
Evidence/Cancer
Guidance
Description
Source
Date:
(MM/DD/YYYY)
Cadmium
..
..
..
B1
IRIS
10/10/2005
Zinc
..
..
..
D
IRIS
10/10/2005
Lead
__
__
__
B2
IRIS
10/10/2005
Pathway: Inhalation
Chemical
of
Concern
Unit Risk
Units
Inhalation
Cancer Slope
Factor
Units
Weight of
Evidence/Cancer
Guidance
Description
Source
Date:
(MM/DD/YYYY)
Cadmium
1.8E-03
ftjg/m3)-1
6.3E+00
(mg/kg-day)"1
B1
IRIS
10/10/2005
Zinc
..
..
..
..
D
IRIS
10/10/2005
Lead
-
-
-
-
B2
IRIS
10/10/2005
Key
- : No information available Weight of Evidence definitions:
IRIS: Integrated Risk Information System, U.S. EPA
A - Human carcinogen
B1 - Probable human carcinogen - Indicates that limited
human data are available
B2 - Probable human carcinogen - Indicates sufficient
evidence in animals and inadequate or no evidence in humans
C - Possible human carcinogen
D - Not classifiable as a human carcinogen
E - Evidence of noncarcinogenicity
-------
Table 6
Non-Cancer Toxicity Data Summary
Pathway: Ingestion, Dermal
Chemical
of
Concern
Chronic/
Subchronic
Oral RfD
Value
Oral RfD
Units
Dermal
RfD
Dermal RfD
Units
Primary Target
Organ
Combined
Uncertainty/
Modifying Factors
Sources of
RfD: Target
Organ
Dates of RfD:
Target Organ
(MM/DD/YYYY)
Cadmium (water)
Chronic
5.0E-04
mg/kg-day
2.5E-05
mg/kg-day
Kidney
10/1
IRIS
10/10/2005
Cadmium (food)
Chronic
1.0E-03
mg/kg-day
2.5E-05
mg/kg-day
Kidney
10/1
IRIS
10/10/2005
Zinc
Chronic
3.0E-01
mg/kg-day
3.0E-01
mg/kg-day
Circulatory
3/1
IRIS
10/10/2005
Lead
-
-
-
-
-
-
-
-
-
Pathway: Inhalation
Chemical
of
Concern
Chronic/
Subchronic
Inhalation
RfC
Inhalation
RfC Units
Inhalation
RfD
Inhalation
RfD Units
Primary Target
Organ
Combined
Uncertainty/
Modifying Factors
Sources of
RfC: RfD:
Target Organ
Dates:
(MM/DD/YYYY)
Cadmium
Chronic
2.0E-04
mg/m3
5.7E-05
mg/kg-day
Kidney
10
NCEA
6/14/1998
Zinc
Chronic
NA
NA
NA
NA
NA
NA
IRIS
10/10/2005
Lead
-
-
-
-
-
-
-
-
-
Key
- : No information available
IRIS: Integrated Risk Information System, U.S. EPA
-------
Table 7
Risk Characterization Summary - Non-Carcinogens
Scenario Timeframe: Current
Receptor Population: Residential (General Public)
Receptor Age: Child
Medium
Exposure
Exposure
Chemical
Primary
Non-Carcinogenic Hazard Quotient
Medium
Point
of Potential
Target Organ(s)
Concern
Ingestion
Inhalation
Dermal
Exposure
Routes Total
Surface Soil
Surface Soil (Yards)
Surface Soil
Cadmium
Kidney
6.1E-01
NA
6.8E-02
6.8E-01
(0-1 inch)
Zinc
Circulatory
3.3E-01
NA
9.2E-04
3.3E-01
Surface Soil Hazard Index Total =
1.0E+00
Chat and Tailings Material
Ambient Air
Ambient Air
Cadmium
Kidney
NA
9.1E-04
NA
9.1E-04
Zinc
N/A
NA
NA
NA
NA
Chat and Tailings Hazard Index Total =
9.1E-04
Groundwater
Groundwater
Private Wells
Cadmium
Kidney
3.8E-01
NA
NA
3.8E-01
Zinc
Circulatory
2.4E-01
NA
NA
2.4E-01
Groundwater Hazard Index Total =
6.2E-01
Receptor Hazard Index =
1.6E+00
Circulatory Hazard Index =
5.7E-01
Kidney Hazard Index =
1.1E+00
Scenario Timeframe: Current/Future
Receptor Population: Residential (Subsistence)
Receptor Age: Adult
Medium
Exposure
Exposure
Chemical
Primary
Non-Carcinogenic Hazard Quotient
Medium
Point
of Potential
Target Organ(s)
Concern
Ingestion
Inhalation
Dermal
Exposure
Routes Total
Surface Soil
Surface Soil (Yards)
Surface Soil
Cadmium
Kidney
5.5E-02
NA
2.2E-03
5.7E-02
(0-1 inch)
Zinc
Circulatory
3.7E-02
NA
3.7E-05
3.7E-02
Surface Soil Hazard Index Total =
9.4E-02
Chat and Tailings Material
Ambient Air
Ambient Air
Cadmium
Kidney
NA
6.1E-04
NA
6.1E-04
Zinc
N/A
NA
NA
NA
NA
Chat Pile Material and Tailings Hazard Index Total =
6.1E-04
Surface Soil (residential,
Animal Tissue
Small Game
Cadmium
Kidney
4.4E-04
NA
NA
4.4E-04
smelter, transition zone)
(Bird, Rabbit)
Zinc
Circulatory
6.7E-05
NA
NA
6.7E-05
Beef (Cattle)
Cadmium
Kidney
1.8E-08
NA
NA
1.8E-08
* high fish diet
Zinc
Circulatory
6.5E-09
NA
NA
6.5E-09
Beef (Cattle)
Cadmium
Kidney
1.6E-07
NA
NA
1.6E-07
* high Beef diet
Zinc
Circulatory
5.8E-08
NA
NA
5.8E-08
Surface Soil (residential, smelter, transition zone) Hazard Index Total (High Fish Diet) =
5.0E-04
Surface Soil (residential, smelter, transition zone) Hazard Index Total (High Beef Diet) =
5.0E-04
-------
Table 7
Risk Characterization Summary - Non-Carcinogens
Scenario Timeframe: Current
Receptor Population: Residential (General Public)
Receptor Age: Child
Plant Tissue
Asparagus (above ground)
Cadmium
Kidney
2.1E+01
NA
NA
2.1E+01
Transition Zone
Zinc
Circulatory
1.8E+00
NA
NA
1.8E+00
Asparagus (root)
Cadmium
Kidney
4.8E+01
NA
NA
4.8E+01
Zinc
Circulatory
1.8E+01
NA
NA
1.8E+01
VWIlow (above ground)
Cadmium
Kidney
6.9E+01
NA
NA
6.9E+01
Zinc
Circulatory
6.0E+00
NA
NA
6.0E+00
Willow (root)
Cadmium
Kidney
1.9E+02
NA
NA
1.9E+02
Zinc
Circulatory
5.9E+01
NA
NA
5.9E+01
Cattail (above ground)
Cadmium
Kidney
7.6E+01
NA
NA
7.6E+01
Zinc
Circulatory
3.3E+01
NA
NA
3.3E+01
Cattail (root)
Cadmium
Kidney
2.4E+02
NA
NA
2.4E+02
Zinc
Circulatory
5.6E+01
NA
NA
5.6E+01
Transition Zone Hazard Index Total =
8.2E+02
Aquatic Biota
Fish Tissue/
Aquatic Food Tissue
Cadmium
Kidney
4.0E+00
NA
NA
4.0E+00
Aquatic Food
(Mussels etc.)
Zinc
Circulatory
6.5E-01
NA
NA
6.5E-01
Fish Tissue
Cadmium
Kidney
2.2E+00
NA
NA
2.2E+00
* high fish diet
Zinc
Circulatory
9.0E-01
NA
NA
9.0E-01
Fish Tissue
Cadmium
Kidney
1.8E-01
NA
NA
1.8E-01
* high Beef diet
Zinc
Circulatory
7.6E-02
NA
NA
7.6E-02
Aquatic Biota Total (High Fish Diet) =
7.7E+00
Aquatic Biota Total (High Beef Diet) =
5.0E+00
Groundwater
Groundwater
Groundwater
Zinc
Circulatory
4.2E-05
NA
NA
4.2E-05
Groundwater Ha
zard Index Total =
4.2E-05
Receptor Hazard Index (High Fish Diet) =
8.2E+02
Receptor Hazard Index (High Beef Diet) =
8.2E+02
Circulatory Hazard Index (High Fish Diet) =
2E+02
Kidney Hazard Index (High Fish Diet) =
6E+02
Circulatory Hazard Index (High Beef Diet) =
2E+02
Kidney Hazard Index (High Beef Diet) =
6E+02
-------
Table 8
Summary of Blood Lead Concentrations (PbBs) Risk Estimations (from ALM)
Exposure Point Concentrations
Adult Lead Model Results
Food lead
concentration (Food
Item 1 - Small
Mammals) (ug/g)
Food lead
concentration
(Food Item 2 - Beef)
(ug/g)
Food lead
Food lead
concentration
(Food Item 4 - Fish)
(ug/g)
Food lead
Food lead
Food lead
Food lead
concentration (Food
Item 8 - Willow [root])
(ug/g)
Food lead
Food lead
concentration (Food
Item 10 - Cattail [root])
(ug/g)
Resident
Average Measured
Soil Concentration
(mg/kg)
concentration
(Food Item 3 -
Aquatic Biota)
(ug/g)
concentration (Food
Item 5 - Asparagus
[above ground])
(ug/g)
concentration (Food
Item 6 - Asparagus
[root])
(ug/g)
concentration (Food
Item 7 - Willow [above
ground])
(ug/g)
concentration (Food
Item 9 - Cattail [above
ground])
(ug/g)
Geo Mean
%Above
target BLL
3 **
29.1
3.8E-t02
1.2E-01
1.6E+00
4.3E-01
1.9E+01
5.6E-t02
1.1E+01
1.0E+03
2.9E+02
1.1E+03
58,400
100%
5**
88.4
3.8E-t02
1.2E-01
1.6E+00
4.3E-01
1.9E+01
5.6E-t02
1.1E+01
1.0E+03
2.9E+02
1.1E+03
58,400
100%
41
643.3
3.181
6.7%
Note:
** Resident on BIAIand
Only 3 of 46 residential properties exceeded the blood lead goal as described in the 1994 OSWER Directive of no more than 5% of children exceeding 10 ug/dL blood lead are presented.
-------
Table 9
Summary of Blood Lead Concentrations (PbBs) Risk Estimations (from IEUBK Model)
Exposure Point Concentrations
IEUBK Model Results
Resident
Modeled Air Average Measured
Concentration Soil Concentration
(ug/m3) (mg/kg)
Average Measured
Groundwater
Concentration
(ug/L)
Geo Mean
%Above
target BLL
26
0.000424
404.8
4(1)
5.061
7.365
39
0.002348
491
4(1)
5.749
11.943
41
0.004562
643.3
4(1)
6.910
21.578
Note:
Only 3 of 46 residential properties exceeded the blood lead goal as described in the 1994 OSWER Directive of no more than
5% of children exceeding 10 ug/dL blood lead are presented.
(1) Default concentration of 4 ug/L was used for those residents without groundwater samples.
-------
TABLE 10
Comparative Analysis of Remedial Alternatives with Respect to Cost
Tar Creek Superfund Site
Criterion
Alternative 1
Alternative 4
Alternative 5
Alternative 8
No Further Action
Phased Consolidation, On-
Voluntary Relocation,
Total Source
Site Disposal and
Phased Consolidation, On-
Consolidation, On-Site
Institutional Controls
Site Disposal, and
Institutional Controls
Disposal and Institutional
Controls
Direct Capital Costs
Not Calculated
$182,736,000
$224,794,000
$319,401,000
Indirect Capital Costs
Not Calculated
$107,641,000
$107,641,000
$159,574,000
Total Capital Costs
Not Calculated
$290,377,000
$332,435,000
$478,975,000
Operating and Maintenance
Costs
Not Calculated
$375,000/year decreasing to
$125,000/year
$375,000/year decreasing to
$125,000/year
$475,000/year decreasing to
$225,000/year
Net Present Value
Assuming a 7% Discount
Rate
Not Calculated
$167,735,000
$167,288,000
$255,909,000
USEPA\348273\PR04\TABLE 10 FINAL COSTS
PAGE 1 OF 1
JULY 2007
-------
TABLE 11 - ALTERNATIVE 5
VOLUNTARY RELOCATION
Item # Item Description
Est. Quantity
Units
Est. Unit Cost
Estimated Cost
Cost Basis Assumptions
1. Relocation Expenses
1.1 Residential Houses
678
houses
Estimated guantity of residential home properties based upon update from ODEQ, 2007.
a. Houses to be bought by state program (Phase I)
256
houses
Estimated guantity based upon update from LICRA, 2007,10/2/2007.
b. Remaining houses addressed by Alternative 5
522
houses
$58,290.00
$30,427,380
State Buyout Remaining quantity of properties based upon update from LICRA (10/2/2007) plus 100
2006 additional properties (422+100=522). Average cost of property $58,290 after 207 homes.
c. Moving allowance
634
relocates
$1,000.00
$634,000
State Buyout Moving allowance of $1000 per household. Of the 487 remaining households, 112 are
2006 renters.
d. Renters assistance
112
renters
$4,408.00
$493,696
State Buyout
2006 Current buyout average after 26 renters
e. Demolition and disposal of remediated houses
417
houses
$5,500.00
$2,293,500
Based on State 2005 buyout, $5,500 per structure. State felt that cost differential likely would
be offset by salvage/resale value.
f. Demolition and disposal of non-remediated houses
105
houses
$5,500.00
$577,500
1.2 Commercial Properties
66
businesses
Estimated quantity of commercial properties based upon update from ODEQ, 2007.
a. Commercial properties to be bought by state program
(Phase I)
19
businesses
Estimated quantity based upon update from LICRA, 10/2/2007.
b. Remaining commercial properties addressed by Alternative 5
47
businesses
$107,674.00
$5,060,678
Current buyout average of $107,674/property, after 19 commercial properties.
c. Demolition and disposal of commercial properties
47
businesses
$11,000.00
$517,000
State Est. Assumes double residential demolition cost.
d. Moving allowance
47
businesses
$2,000.00
$94,000
State law provides $2,000 (max.) moving allowance for commercial properties.
|Subtotal Direct Capital Costs
$40,097,754|
2. LICRA Administration (Indirect) Costs
Assumes tasks in EPA's SF Relocation SOW Template Model SOW (percentages are a
EPA 2004 proportion of the direct relocation costs).
a. Task 1 - Planning
$0
b. Task 2 - Coordination and Communication
$0
c. Task 3 - Advisory Services
$0
d. Task 4 - Appraisal and Acguisition
$1,328,340
State contract: $2,645/residence,$295/renter,$3,845/commercial. Est. cost for additional 100
residential properties, $264,500 (100x$2,645). Total est. cost $1,328,340
($1,063,840+$264,500)
e. Task 5 - Relocation
$0
f. Task 6 - Follow Up
$0
g. Task 7 - Appeals
$0
h. Task 8 - Reporting
$0
i. Task 9 - Project Management and Closeout
$132,000
Current buyout is approximately $66,000/year (x 2 years)
j. Contingencies
$500,000
Current state buyout hold back
|Subtotal LICRA Administration (Indirect) Costs
$1,960,340|
3. |Total Capital Costs (2006 dollars)
$42,058,094|
Equal to Direct Capital Costs + URA Administration Costs; costs are already present values
4. Annual Operation and Maintenance Costs
a. Administer institutional controls
1 lump
sum
$0
$0
LICRA does include O&M.
b. Vegetation management
1 lump sum
$0
$0
LICRA does include O&M.
|Subtotal Annual O&M Costs
$0|
Net Present Value of Direct and LICDA Admin. Costs
$42,058,094
|Total Net Present Value $42,058,094|
Assume 100 residential properties (about 50% of the 211), not eligible for state buyout and remain in the area, to be relocated by EPA
Ref: October 3, 2007 e-mail from J. D. strong, Office of the secretary of the Environment
Page 1 of 7
February 2008
-------
Remedial Component
Item #
Item Description
Est. Quantity
Units
Est. Unit Cost
Estimated Cost
Cost Basis Assumptions
1.
Chat Pile and Base Removal from the NE Distal Zone by
Excavation and Hauling
100% of material located in this area is removed by excavation and hauling; material
delivered to chat washing operator located in central portion of the Site.
a. Clear, grub, and remove old structures
559
acres
$533.50
$298,227
Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).
b. Excavate and load chat
2,391,000
cu.yds.
$1.70
$4,064,700
CCI See detail sheets for unit rate development.
c. Haul, dump and place, 12-mile roundtrip
2,391,000
cu.yds.
$3.11
$7,436,010
CCI See detail sheets for unit rate development.
d. Deep till excavated area and buffer zone
559
acres
$911.00
$509,249
Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
CCI average speed used. The appropriate number of moves is included in the unit cost.
e. Amend soils prior to revegetation
559
acres
$320.00
$178,880
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
f. Revegetate excavated areas
559
acres
$1,200.00
$670,800
CCI Land area is disced, seeded and mulched.
|Subtotal Item 1
$13,157,866|
2.
Chat Pile and Base Removal from the SE Distal Zone by
Excavation and Hauling
100% of material located in this area is removed by excavation and hauling; material
delivered to chat washing operator located in central portion of the Site.
a. Clear, grub, and remove old structures
172
acres
$533.50
$91,762
Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).
b. Excavate and load chat
630,000
cu.yds.
$1.70
$1,071,000
CCI See detail sheets for unit rate development.
c. Haul, dump and place, 12-mile roundtrip
630,000
cu.yds.
$3.11
$1,959,300
CCI See detail sheets for unit rate development.
d. Deep till excavated area and buffer zone
172
acres
$911.00
$156,692
Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
CCI average speed used. The appropriate number of moves is included in the unit cost.
e. Amend soils prior to revegetation
172
acres
$320.00
$55,040
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
f. Revegetate excavated/deep tilled area
172
acres
$1,200.00
$206,400
CCI Land area is disced, seeded and mulched.
|Subtotal Item 2
$3,540,194|
3
Chat Pile and Base Removal from the Elm Creek Watershed
Distal Zone by Excavation and Hauling
100% of material located in this area is removed by excavation and hauling; material
delivered to chat washing operator located in central portion of the Site.
a. Clear, grub, and remove old structures
381
acres
$533.50
$203,264
Entire area of piles and bases plus 50-foot buffer zone area. Does not include removal of
OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).
b. Excavate and load chat
3,138,000
cu.yds.
$1.70
$5,334,600
CCI See detail sheets for unit rate development.
c. Haul, dump and place, 12-mile roundtrip
3,138,000
cu.yds.
$3.11
$9,759,180
CCI See detail sheets for unit rate development.
d. Deep till excavated area and buffer zone
381
acres
$911.00
$347,091
Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
CCI average speed used. The appropriate number of moves is included in the unit cost.
e. Amend soils prior to revegetation
381
acres
$320.00
$121,920
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
f. Revegetate excavated/deep tilled area
381
acres
$1,200.00
$457,200
CCI Land area is disced, seeded and mulched.
|Subtotal Item 3
$16,223,255|
4.
Excavate, Haul and Dispose of Smelter Wastes in a Local
Repository
a. Clear, grub, and remove old structures
14
acres
$533.00
$7,462
Includes brush and tree removal around source material area and affected soils area. Does
OCC-1 not include removal of buildings or reinforced structures.
b. Excavate and load smelter waste
1,846
cu.yds.
$1.70
$3,138
CCI Shallow excavation, approximately 1 feet deep. See details sheets for unit rate development.
c. Haul, dump and place, 12-mile roundtrip
1,846
cu.yds.
$3.11
$5,741
CCI See detail sheets for unit rate development.
d. Deep till excavated area and smelter affected soils
14
acres
$911.00
$12,754
Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
CCI average speed used. The appropriate number of moves is included in the unit cost.
e. Add biosolids or organic matter
280
tons
$30.00
$8,400
Jasper 20 tons per acre.
f. Amend soils prior to revegetation
14
acres
$320.00
$4,480
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
g. Revegetate excavated/deep tilled area
14
acres
$1,200.00
$16,800
CCI Land area is disced, seeded and mulched.
iSubtotal Item 4
5.
Inject Fine Tailings into Mine Workings
Assumes 61 ponds containing an estimated 5,041,000 yd of material (includes 10% of
washed fines generated by processing) covering an estimated area of 569 acres is injected.
Page 2 of 7
February 2008
-------
a. Clear and grub fine tailings and buffer zone areas
831
acres
$533.00
$442,923
Entire area of ponds addressed by injection plus 50-foot buffer zone area. Does not include
OCC-1 removal of buildings or reinforced structures (i.e., mill foundations, etc.).
b. Mobilize/move between ponds and injection locations
287
location
$13,012.00
$3,734,444
CCI Assumes one move per injection boring (i.e., location) plus one mobilization.
c. Injection boring installation
286
boring
$16,000.00
$4,582,727
Venture Drilling One 10-inch diameter injection boring per 17,600 yd3 of fine tailings material.
d. Extraction boring installation
61
boring
$16,000.00
$976,000
Venture Drilling One 10-inch diameter extraction boring per pond.
e. Boring abandonment
347
boring
$10,000.00
$3,474,205
Venture Drilling Bladder installation and cement grout to surface.
f. Inject fines at 200 tons/hour
5,041,000
cu.yds.
$5.76
$29,036,160
CCI See detail sheets for unit rate development.
g. Deep till underlying soils and buffer zone
831
acres
$911.00
$757,041
Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the other,
two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH average
CCI speed used. The appropriate number of moves is included in the unit cost.
h. Amend soils prior to revegetation
831
acres
$320.00
$265,920
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
i. Revegetate underlying soils/deep tilled areas
831
acres
$1,200.00
$997,200
CCI Land area is disced, seeded and mulched.
ISubtotal Item 5
$44,266,620|
Complete Hydrogeologic Studies
a. Hydrogeologic investigations and studies
1
lump sum
$3,000,000.00
$3,000,000
Studies are completed to assess hydrogeologic system and potential impacts resulting from
Quapaw Tribe injection of source materials.
iSubtotal Item 6 $3,000,0001
7.
Cover Fine Tailings in Place with Soil Cover
a. Clear and grub fine tailings and buffer zone areas
275
acres
$533.00
$146,575
Entire area of ponds addressed by covering plus 50-foot buffer zone area. Does not include
OCC-1 removal of buildings or reinforced structures (i.e., mill foundations, etc.).
b. Regrade and recontour tailings and berms
251
acres
$2,400.00
$602,400
CCI No change in surface area.
c. Furnish and load cover soil
898,000
cu.yds.
$10.24
$9,195,520
Soil cover eguivalentto 12-inches clay and 12-inches loam. See detail sheets for unit rate
CCI development.
d. Haul and dump cover soil( 14.2 miles round trip)
898,000
cu.yds.
$3.41
$3,062,180
CCI See detail sheets for unit rate development.
e. Compact cover soil
898,000
cu.yds.
$1.26
$1,131,480
CCI See detail sheets for unit rate development.
f. Deep till buffer zone
24
acres
$911.00
$21,864
Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
CCI average speed used. The appropriate number of moves is included in the unit cost.
g. Amend soils prior to revegetation
275
acres
$320.00
$88,000
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
h. Establish cover vegetation/revegetate deep tilled area
275
acres
$1,200.00
$330,000
CCI Land area is disced, seeded and mulched.
i. Institutional control - deed notice
28
parcel
$500.00
$13,750
Eng. Estimate Assumes 1 parcel (i.e. deed notice) per 10 acres.
ISubtotal Item 7
$14,591,769|
8.
Integrate Near Stream Source Materials and Control
Seepage/Runoff
Interim actions that may be reguired to prevent further damages to resources while chat
processing (by others) is ongoing or before full-scale remedial actions can take place.
a. Clear and grub floodway areas
581
acres
$533.50
$309,964
CCI Does not include removal of buildings or reinforced structures (i.e., mill foundations, etc.).
b. Integrate floodway chat with original source
1,252,952
cu.yds.
$2.26
$2,831,672
Assumes near-stream chat within 200 feet of streams reguires integration with primary
CCI source. Assumes dozer work with no loading or hauling.
c. Integrate floodway fine tailings with original source
283,095
cu.yds.
$2.26
$639,795
Assumes near-stream tailings within 200 feet of streams reguire consolidation outside the
CCI floodway. Assumes dozer work with no loading or hauling.
d. Furnish and install rip-rap or revetment
4,228
cu.yds.
$39.11
$165,357
Assumes 48" of rip-rap placed at bends in stream channels where chat or tailings are
located. Quantity based on 0.44tons/L.F. of stream length(3.2 miles). Rip rap from Midwest
CCI Mineral, Quapaw Quarry At $13.50/ton loaded plus 5.85% sales tax
e. Install berms and dikes - small berms
71,770
cu.yds.
$14.91
$1,070,091
CCI Assume 2.67 CY of compacted clay per lineal foot of berm. Estimated using D-4 and CAT
f. Install sheet piling to prevent seepage and direct runoff
90,414
sguare feet
$25.00
$2,260,350
CCI Assumes estimated linear distance of 5,023 feet, 18-foot sheet length.
g. Deep till excavated areas
581
acres
$911.00
$529,291
Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
CCI average speed used. The appropriate number of moves is included in the unit cost.
h. Amend soils prior to vegetation
581
acres
$320.00
$185,920
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
i. Revegetate excavated areas
581
acres
$1,200.00
$697,200
CCI Land area is disced, seeded and mulched.
ISubtotal Item 8
$8,689,639 |
9.
Excavation of In-Stream Source Materials from Tar, Lytle,
and Beaver Creeks
Assumes sections of Tar Creek, Lytle Creek, Elm Creek, and Beavers Creek reguire source
removal from stream beds and immediate banks.
a. Clear and grub stream banks
35
acres
$1,800.00
$63,000
CCI
Page 3 of 7
February 2008
-------
Assumes near-stream chat within 200 feet of streams requires integration with primary
source using a D-8. Assumes a Cat 330 hoe to pull additional material out of the streams
b. Excavate source materials from streams
18,394
cu.yds.
$17.51
$322,079
CCI and D-8 to integrate it with its primary source.
c. Bank work and regrading
49,021
cu.yds.
$2.26
$110,787
CCI Estimated using D-4
Assumes 48" of rip-rap placed at bends in stream channels where chat or tailings are
located. Quantity based on 0.44tons/L.F. of stream length (2.7 miles). Rip rap from Midwest
d. Furnish and install rip-rap or revetment
3,595
cu.yds.
$39.11
$140,600
CCI Mineral, Quapaw Quarry At $13.50/ton loaded plus 5.85% sales tax
e. Amend bank soils prior to revegetation
35
acres
$320.00
$11,200
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
f. Revegetate stream bank
35
acres
$1,200.00
$42,000
CCI Land area is disced, seeded and mulched.
iSubtotal Item 9 $689,667|
Covering of In-Stream Source Materials from Tar, Lytle, and
Assumes sections of Tar Creek, Lytle Creek, Elm Creek, and Beavers Creek require
10.
a. Stream liner (60-mil HDPE)
2,059,200
square feet
$2.21
$4,550,832
60 mil HDPE liner 36 feet wide installed in 10.8 miles of stream. 30' wide under stream with
CCI 3' buried as anchors on each side
b. Filter blanket (fines)
152,533
cu.yds.
$14.33
$2,185,803
The 152,533 cy is 10.8 miles @ 2' thick and 36' wide. The material will be purchased from a
local quarry, hauled, dumped, spread, and compacted. Price at the quarry is $3.95/ton
CCI loaded plus 5.85% sales tax.
c. Bank work and regrading, ground prep
305,067
cu.yds.
$2.26
$689,451
CCI Estimated using D-4
d. Furnish and install rip-rap
152,533
cu.yds.
$39.11
$5,965,579
Assumes 48" of rip-rap placed at bends in stream channels where chat or tailings are
located. Quantity based on 0.44tons/L.F. of stream length. Rip rap from Midwest Mineral,
CCI Quapaw Quarry at $13.50/ton loaded plus 5.85% sales tax.
e. Amend bank soils prior to vegetation
35
acres
$320.00
$11,200
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
f. Revegetate stream bank
35
acres
$1,200.00
$42,000
CCI Land area is disced, seeded and mulched.
|Subtotal Item 10
$13,444,864|
11.
Provide Alternative Water Supply for Impacted Rural
Residential Wells
a. Connect affected households to supplied water system
2
households
$15,000.00
$30,000
Alternative supplied water system is within economically feasible distance to complete
Best estimate connection.
ISubtotal Item 11
$30,000|
12.
Excavate Rural Residential Yard Soils
a. Excavate, backfill, and restore residential yard soils
5
households
$28,000.00
$140,000
EPA-2005 Average cost of OU-2 yards completed in 2005.
$140,000|
Page 4 of 7
February 2008
-------
13.
Construction and Closure of On-Site Repository
Construction of a 28-acre repository capable of receiving an estimated 998,000 yd 3 of source
materials and associated debris.
a. Property acquisition including surrounding buffer area
56
acres
$1,000.00
$56,000
Eng. Estimate 28 acre repository with surrounding 200-foot buffer zone equivalent to 28 additional acres.
b. Clear and grub
28
acres
$533.00
$14,924
Entire area of proposed repository. Does not include removal of buildings or reinforced
OCC-1 structures (i.e., mill foundations, etc.).
c. Grading and site work
28
acres
$2,400.00
$67,200
CCI Upper 6-inches removed and stored.
d. Furnish and load clay liner soil
90,000
cu.yds.
$10.24
$921,600
CCI Liner equivalent to 24-inches clay. See detail sheets for unit rate development.
e. Haul and dump clay liner soil( 14.2 miles round trip)
90,000
cu.yds.
$3.41
$306,900
CCI See detail sheets for unit rate development.
f. Compact clay liner soil
90,000
cu.yds.
$1.26
$113,400
CCI See detail sheets for unit rate development.
g. Furnish, load, and install filter sand
90,000
cu.yds.
$5.00
$450,000
Quapaw Tribe 2-feet thick filter sand layer using drag sands available at no cost.
Soil cover equivalent to 12-inches clay and 12-inches loam. See detail sheets for unit rate
h. Furnish and load cover soils
90,000
cu.yds.
$10.24
$921,600
CCI development.
i. Haul and dump cover soils( 14.2 miles round trip)
90,000
cu.yds.
$3.41
$306,900
CCI See detail sheets for unit rate development.
j. Compact cover soils
90,000
cu.yds.
$1.26
$113,400
CCI See detail sheets for unit rate development.
k. Amend soils prior to vegetation
28
acres
$320.00
$8,960
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
I. Revegetate excavated areas
28
acres
$1,200.00
$33,600
CCI Land area is disced, seeded and mulched.
m. Institutional control - deed notice
1
parcel
$1,000.00
$1,000
Eng. Estimate Assumes 1 parcel (i.e. deed notice) for entire 28-acre repository.
ISubtotal Item 13 $3,315,484|
|Total Phase 1 Direct Capital Costs $121,148,1311
Phase 2 Activities (Years 26 to 30)
Address Non-Processed Chat from Piles, Bases, and Rail
14. Road and Road Beds
14.1 Excavate and Haul to Local Washing Operation
Assumes 76% of all chat has been processed by others (not part of the remedy), with
9,380,000 yd3 remaining to be addressed by the remedy.
Assumes 85% (7,973,000 yd3) of non-processed chat is delivered to an on-site chat washing
85% of all entire acreage covered by piles and bases including 50-foot buffer zone area but
excluding the area already addressed by Distal Area remedy. Does not include removal of
a. Clear, grub, and remove old structures
2,892
acres
$533.50
$1,542,882
OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).
b. Excavate and load chat
7,973,000
cu.yds.
$1.70
$13,554,100
CCI See detail sheets for unit rate development.
c. Haul, dump and place, 12-mile roundtrip
7,973,000
cu.yds.
$3.11
$24,796,030
CCI See detail sheets for unit rate development.
Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
d. Deep till excavated area and buffer zone
2,892
acres
$911.00
$2,634,612
CCI average speed used. The appropriate number of moves is included in the unit cost.
e. Amend soils prior to revegetation
2,892
acres
$320.00
$925,440
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
f. Revegetate excavated areas
2,892
acres
$1,200.00
$3,470,400
CCI Land area is disced, seeded and mulched.
14.2 Excavate and Haul to an On-Site Repository
Assumes 10% (938,000 yd ) of non-processed chat is delivered to an on-site repository.
10% of all entire acreage covered by piles and bases including 50-foot buffer zone area but
excluding the area already addressed by Distal Area remedy. Does not include removal of
a. Clear, grub, and remove old structures
340
acres
$533.50
$181,390
OCC-1 buildings or reinforced structures (i.e., mill foundations, etc.).
b. Excavate and load chat
938,000
cu.yds.
$1.70
$1,594,600
CCI See detail sheets for unit rate development.
c. Haul, dump and place, 12-mile roundtrip
938,000
cu.yds.
$3.11
$2,917,180
CCI See detail sheets for unit rate development.
Two D-8 Dozers, one making one pass with a 16' wide mouldboard gang plow and the
other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
d. Deep till excavated area and buffer zone
340
acres
$911.00
$309,740
CCI average speed used. The appropriate number of moves is included in the unit cost.
e. Amend soils prior to revegetation
340
acres
$320.00
$108,800
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
f. Revegetate excavated areas
340
acres
$1,200.00
$408,000
CCI Land area is disced, seeded and mulched.
Page 5 of 7
February 2008
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14.3. Inject Chat into Mine Workings
Assumes 5% (469,000 yd"
workings.
of non-processed chat is injected into flooded underground mine
a. Clear, grub, and remove old structures
170
acres
$533.00
$90,610
5% of all entire acreage covered by piles and bases including 50-foot buffer zone area but
excluding the area already addressed by Distal Area remedy. Does not include removal of
OCC-1
Moves equivalent to one mobilization and movement between injection sites based upon an
b. Mobilize/move between piles/bases and injection locations
95
location
$16,193.00
$1,535,096
CCI average injection of 5,000 yd3 per boring.
c. Injection boring installation
94
boring
$16,000.00
$1,500,800
Venture Drilling One 10-inch diameter injection boring per 5,000 ydJ of chat material.
d. Extraction boring installation
19
boring
$16,000.00
$300,160
Venture Drilling One 10-inch diameter extraction boring per every 5 injection borings (20-percent).
e. Boring abandonment
113
boring
$10,000.00
$1,125,600
Venture Drilling Bladder installation and cement grout to surface.
f. Inject chat at 100 tons/hour
469,000
cu. yds.
$8.91
$4,178,790
CCI See detail sheets for unit rate development.
I wo D-8 Dozers, one making one pass with a 16'wide mouldboard gang plow and the
other, two passes of a 30" disc harrow and spring tooth harrow pulled in tandem. 3 MPH
g. Deep till underlying soils and buffer zone
170
acres
$911.00
$154,870
CCI average speed used. The appropriate number of moves is included in the unit cost.
h. Amend soils prior to revegetation
170
acres
$320.00
$54,400
CCI 2 tons lime and 100 pounds each of nitrogen and phosphorous fertilizer per acre.
i. Revegetate underlying soils/deep tilled areas
170
acres
$1,200.00
$204,000
CCI Land area is disced, seeded and mulched.
|Total Phase 2 Direct Capital Costs"
$61,587,5001
|Total Direct Capital Costs (Phase 1 + Phase 2)
$182,735,63*21
15. Indirect Capital Costs
a. Develop and implement institutional controls program
1
lump sum
$500,000
$500,000
Best estimate
b Project management
1
lump sum
$9,136,782
$9,136,782
EPA, 2000 Assume 5% of total direct capital cost
c. Remedial design
1
lump sum
$9,136,782
$9,136,782
EPA, 2000 Assume 5% of total direct capital cost
d. Construction oversight and management
1
lump sum
$10,964,138
$10,964,138
EPA, 2000 Assume 6% of total direct capital cost
e. Technical support
1
lump sum
$3,654,713
$3,654,713
Assume 2% of total direct capital cost; assumes performance of monitoring (i.e., air,
groundwater, surface water,) during implementation of the remedy and confirmation
EPA, 2000 sampling.
f. Contingencies
1
lump sum
$36,547,126
$36,547,126
EPA, 2000 Assume 20% of total direct capital cost; 15% scope, 5% bid.
g. Chat sales compliance, environmental monitoring, and
oversight
1
lump sum
$37,701,800
$37,701,800
EPA, 2007 Refer to Appendix E
$107,641,340T
16. |Total Capital Costs"
$290,376,9721
17. Annual Operation and Maintenance Costs
a. Administer landowner agreements 1 lump sum $100,000.00 $100,000 Best estimate Assume 1 FTE plus expenses
b. Administer institutional controls
1
lump sum
$25,000.00
$25,000
Best estimate Assume 1/4 FTE in the Ottawa County clerk's office plus expenses.
c. Vegetation management
1
lump sum
$250,000.00
$250,000
Assumes management of revegetated areas for 3 years after initial seeding. Goes to zero
Best estimate after 20 years.
|Subtotal Annual O&M Costs $375,000{
Page 6 of 7
February 2008
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18.
Net Present Value Cost Analysis
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
Direct Capital Costs
$8,076,542
$8,076,542
$8,076,542
$8,076,542
$8,076,542
$8,076,542
$8,076,542
$8,076,542
Indirect Capital Costs
$1,508,072
$1,508,072
$5,005,049
$5,005,049
$5,005,049
$5,005,049
$5,005,049
$5,005,049
$5,005,049
$5,005,049
Operation and Maintenance Costs
$375,000
$375,000
$375,000
$375,000
$375,000
$375,000
$375,000
$375,000
Total Capital and O&M Costs
$1,508,072
$1,508,072
$13,456,591
$13,456,591
$13,456,591
$13,456,591
$13,456,591
$13,456,591
$13,456,591
$13,456,591
Net Present Value
$1,409,413
$1,317,208
$10,984,587
$10,265,969
$9,594,363
$8,966,695
$8,380,089
$7,831,858
$7,319,494
$6,840,649
Year
1
2
3
4
5
6
7
8
9
10
Net Present Value Cost Analysis
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
Direct Capital Costs
$8,076,542
$8,076,542
$8,076,542
$8,076,542
$8,076,542
$8,076,542
$8,076,542
Indirect Capital Costs
$5,005,049
$5,005,049
$5,005,049
$5,005,049
$5,005,049
$5,005,049
$5,005,049
$1,508,072
$1,508,072
$1,508,072
Operation and Maintenance Costs
$375,000
$375,000
$375,000
$375,000
$375,000
$375,000
$375,000
$375,000
$375,000
$375,000
Total Capital and O&M Costs
$13,456,591
$13,456,591
$13,456,591
$13,456,591
$13,456,591
$13,456,591
$13,456,591
$1,883,072
$1,883,072
$1,883,072
Net Present Value
$6,393,129
$5,974,887
$5,584,007
$5,218,698
$4,877,288
$4,558,213
$4,260,012
$557,133
$520,685
$486,622
Year
11
12
13
14
15
16
17
18
19
20
Net Present Value Cost Analysis
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
Totals
Direct Capital Costs
$12,317,500
$12,317,500
$12,317,500
$12,317,500
$12,317,500
$182,735,630
Indirect Capital Costs
$1,508,072
$1,508,072
$1,508,072
$1,508,072
$1,508,072
$3,496,977
$3,496,977
$3,496,977
$3,496,977
$3,496,977
$107,641,340
Operation and Maintenance Costs
$375,000
$375,000
$125,000
$125,000
$125,000
$125,000
$125,000
$125,000
$125,000
$125,000
$8,500,000
Total Capital and O&M Costs
$1,883,072
$1,883,072
$1,633,072
$1,633,072
$1,633,072
$15,939,477
$15,939,477
$15,939,477
$15,939,477
$15,939,477
$298,876,970
Net Present Value
$454,787
$425,034
$344,491
$321,955
$300,892
$2,744,706
$2,565,146
$2,397,333
$2,240,498
$2,093,923
$125,229,763
Year
21
22
23
24
25
26
27
28
29
30
|Total Net Present Value for Phase 1 and 2
$125,229,763|
|Total Net Present Value for Voluntary Relocation
$42,058,094|
|Total Net Present Value for Alternative 5
$167,287,857|
Notes and Assumptions:
Phase 1 Direct Capital Costs are spread evenly over 15 years in the Net Present Value calculation (years 3-17).
Phase 2 Direct Capital Costs are spread evenly over years 26 through 30 in the Net Present Value calculation.
Assume indirect capital costs are spread evenly over the 20-year construction timeframe in years 3 to 17 and 26 to 30, with the exception of item"g' which is spread evenly over the first 25 years.
Assume O&M costs, $375,000/year, start in year 3 and continue for 20 years, then drop to $125,000 per year.
The Net Present Value analysis assumes 30 years of O&M at a discount rate of 7 percent.
Page 7 of 7
February 2008
-------
Table 12
Final Cleanup Levels for Chemicals of Concern
Media: Source Material/Soil
Site Area: Sitewide
Available Use: Future Residential
Controls to Ensure Restricted Use: Institutional Controls for Containment Area Only
Chemicals of Concern
Cleanup Level
Basis for Cleanup
Level
Risk at Cleanup
Level
Cadmium
10 mg/kg
(see Note 2)
Ecological Risk
Assessment
LOAEL for
Vermivores
(see Note 3)
Lead
500 mg/kg
(see Note 1)
Human Health Risk
Assessment
< 5% of Children and
Adolescents
Exceeding 10 ug/dL
Blood-lead Level
Zinc
1100 mg/kg
(see Note 2)
Ecological Risk
Assessment
LOAEL for
Vermivores
(see Note 3)
Notes
1. Verification of the cleanup level for lead should be conducted by analyzing the portion of
the material that passes through a #60 mesh sieve.
2. Verification of the cleanup level for cadmium and zinc should be conducted by analyzing
the bulk material without sieving.
3. The corresponding human health risk is an HI of .25 for Cadmium, and an HI of .05 for
Zinc.
Media: Groundwater
Site Area: Site Water Tap
Available Use: Future Residential
Controls to Ensure Restricted Use: N/A
Chemicals of
Concern
Cleanup Level
Basis for Cleanup
Level
Risk at Cleanup
Level
Lead
.015 mg/L
National Primary
Drinking Water
Standard for Lead -
Treatment
Technology Based
Cleanup level is
treatment technology
based
Notes
1. See Table 13 (Final ARARs for the Selected Remedy) for discussion of the requirements
for lead in drinking water.
-------
Table 13: Final ARARs for S<
sleeted Remedy
Authority
Medium
Requirement
Status
Synopsis of
Requirement
Action to be Taken to
Attain Requirement
Federal Regulatory
Requirement
Ground
Water
Federal Safe Drinking
Water Act
National Primary Drinking
Water Regulations
Subpart I
40CFR Part 141.8
Relevant and
Appropriate
The requirements of subpart I
constitute the national primary
drinking water regulations for lead.
The provisions of this subpart
apply to community water systems
and non-transient, non-community
water systems.
The selected remedy will
comply with these
regulations by providing an
alternative water supply for
rural residences where
mining-related contaminants
in water drawn from wells
exceed .015 mg/L for lead.
Federal Regulatory
Requirement
Air
Clean Air Act
National Primary and
Secondary Ambient Air
Quality Standards
40 CFR Part 50.6 (PM10)
and Part 50.12 (Lead)
Relevant and
Appropriate
PMin
The level of the national primary
and secondary 24-hour ambient
air quality standards for particulate
matter is 150 micrograms per
cubic meter (|jg/m3), 24-hour
average concentration.
Lead
National primary and secondary
ambient air quality standards for
lead and its compounds,
measured as elemental lead are:
1.5 micrograms per cubic meter,
maximum arithmetic mean
averaged over a calendar quarter.
Best Management Practices
will be implemented for the
response actions to prevent
the emissions of lead and
particulates. Periodic air
monitoring will be conducted
to ensure that the BMPs are
meeting the standands.
Federal Regulatory
Requirement
Surface
Water
Clean Water Act
National Pollutant
Discharge Elimination
System
40 CFR Part 122.26
Stormwater Discharges
Relevant and
Appropriate
These rules were established
specifically for discharges of
waters composed entirely of
storm water from industrial
facilities, including most mining
facilities, that are not already
the subject of an NPDES
permit. The Federal Storm
Implementation of all
response actions will
include PPPs developed
during the remedial design
stage and the
implementation of BMPs will
be required throughout the
implementation of the
Page 1 of 6
-------
Table 13: Final ARARs for S<
sleeted Remedy
Authority
Medium
Requirement
Status
Synopsis of
Requirement
Action to be Taken to
Attain Requirement
Water regulations include
requirements for obtaining
storm water permits,
implementing best
management practices (BMPs)
and developing pollution
prevention plans (PPPs) at
industrial facilities and
construction sites. Industrial
activity includes active and
inactive mining areas.
remedy.
Federal Regulatory
Requirement
NA
National Historic
Preservation Act
16 USC Sec. 470
40CFR Part 6.301(b)
Relevant and
Appropriate
Requires Federal agencies to
take into account the effect of
any Federally assisted
undertaking of licensing on any
district, site, building, structure,
or object that is included in or
eligible for Register of Historic
Places
A review was conducted
during the RI/FS by the
COE to identify locations
that would be eligible for the
Register of Historic Places.
Implementation of the
remedy will be carried out in
such a way to minimize any
impact on the identified
locations.
Federal Regulatory
Requirement
Surface
Water,
Ground
Water, Soil,
Source
Material
Endangered Species Act
16 USC Sees. 1531-1544
40CFR Part 6.302(h)
Relevant and
Appropriate
Requires Federal agencies to
identify effects of any Federal
actions where Threatened or
Endangered Species or Critical
habitat may occur.
The implementation of the
remedy will be designed to
minimize any impact on
critical habitats identified by
USFWS for the Ozark
cavefish. Based on
available information, the
Ozark cavefish is not found
within the Site, however, as
part of this ROD, EPA will
conduct a hydrogeological
study that could be used to
evaluate specific locations
where habitat may exist
outside the boundaries of
the site.
Page 2 of 6
-------
Table 13: Final ARARs for S<
sleeted Remedy
Authority
Medium
Requirement
Status
Synopsis of
Requirement
Action to be Taken to
Attain Requirement
Federal Regulatory
Requirement
Ground
Water
Safe Drinking Water Act
40 CFR Part 144
Underground Injection
Control Program
Applicable
for Indian
lands
Relevant and
Appropriate
for non-
Indian lands
The Underground Injection
Control (UIC) program defines
the performance standards for
injection activities. The UIC
regulations classify the type of
injection in the ROD as a
Class V injection well because
it constitutes a mine backfill
well used to inject mill tailings
into mined out portions of the
subsurface.
Specific requirements include
a prohibition of the movement
of fluid containing any
contaminant into a
underground source of
drinking water, if the presence
of that contaminant causes a
violation of the primary
drinking water standards under
40 CFR part 141, other health
based standards, or may
otherwise adversely affect the
health of persons.
40 CFR part 141 applies to
public water systems.
Wells must be closed in a
manner that complies with the
above prohibition of fluid
movement.
The remedy includes the
implementation of a site-
wide hydrogeologic study to
evaluate the potential
impacts from the injection of
source materials into the
mine workings. The results
of this study will be used to
gauge the impacts to
underground sources of
drinking water.
State Regulatory
Requirement
Groundwater
Oklahoma Solid Waste
Management Act, 27A
O.S. § 2-6-701 et seq.
Applicable
for non-
Indian lands
The State UIC requires
groundwater monitoring,
analysis of injected fluids and
a description of the geologic
The remedy includes the
implementation of a site-
wide hydrogeologic study to
evaluate the potential
Page 3 of 6
-------
Table 13: Final ARARs for S<
sleeted Remedy
Authority
Medium
Requirement
Status
Synopsis of
Requirement
Action to be Taken to
Attain Requirement
Management of Solid
Waste
Title 252 OAC, Chapter
652
Underground Injection
Control
strata and any additional
information required to
demonstrate compliance with
the federal requirements in 40
CFR 144.12.
impacts from the injection of
source materials into the
mine workings. The results
of this study will be used to
gauge the impacts to
underground sources of
drinking water.
Federal Regulatory
Requirement
Surface
Water
Clean Water Act §404
33 CFR parts 320-330 and
40 CFR part 230
Relevant and
Appropriate
Regulates the discharge of
dredged or fill materials into
waters of the U.S. Discharges
of dredged or fill materials are
not permitted unless there is
no practicable alternative that
would have less adverse
impact on the aquatic
ecosystem. Any proposed
discharge must avoid, to the
fullest extent practicable,
adverse effects, especially on
aquatic ecosystems.
Unavoidable impacts must be
minimized, and impacts that
cannot be minimized must be
mitigated.
As part of the selected
remedy under this ROD, a
watershed-based approach
will be taken to address the
potential effects remedial
actions may have on the
local watersheds. A
baseline hydrology model
will be developed as part of
the remedial design to
reflect the existing land uses
in the basin. The model
may also be used as a
planning and design tool to
prepare a comprehensive
watershed plan.
State Regulatory
Requirement
Ground
Water
Oklahoma Water Quality
Standards
OAC 785:45 Appendix H
Beneficial Use Designations
for Certain Limited Areas of
Groundwater
Applicable
The Oklahoma Water
Resources Board (OWRB)
regulations place restrictions
on any new well construction
in the Boone formation.
Monitor wells installed
during the response action
will be designed to comply
with special well
construction standards.
ODEQ will also ensure that
new water wells installed at
the Site meet the special
well construction standards.
State Regulatory
Requirement
Soil
Oklahoma Statutes 27A §
2-7-123(B)
Applicable
The ODEQ shall file a
recordable notice of
remediation or related action
taken pursuant to the federal
ODEQ will file the deed
notice upon completion of
construction at each
individual property requiring
Page 4 of 6
-------
Table 13: Final ARARs for S<
sleeted Remedy
Authority
Medium
Requirement
Status
Synopsis of
Requirement
Action to be Taken to
Attain Requirement
Comprehensive Environmental
Response, Compensation and
Liability Act in the land records
of the county in which the site
is located. The notice shall
contain a legal description of
the affected property and shall
identify all engineering controls
used to ensure the
effectiveness of the
remediation.
The notices shall also contain
a prohibition against engaging
in any activities that cause or
could cause damage to the
remediation or the engineering
controls, or recontamination of
the soil or groundwater. The
notices shall also contain any
appropriate restrictions on land
use or other activities that are
incompatible with the cleanup
level, including, but not limited
to, restrictions against using
groundwater for drinking or
irrigation purposes or
redeveloping the land for
residential use.
engineering controls.
State Regulatory
Requirement
Soil/Source
Material
Oklahoma Solid Waste
Management Act, 27A
O.S. §2-10-101 etseq.
Management of Solid
Waste Title 252 OAC,
Chapter 515
Applicable
The Oklahoma statute and
rules establish requirements
for construction of non-
hazardous waste landfills. The
definition of non-hazardous
industrial waste includes the
types of mining waste found at
the Tar Creek site.
The design and construction
of the repositories in the
remedy will comply with the
requirements established in
Chapter 515. Any
alternative design will
require the approval of EPA.
The cover for the fine
Page 5 of 6
-------
Table 13: Final ARARs for S<
sleeted Remedy
Authority
Medium
Requirement
Status
Synopsis of
Requirement
Action to be Taken to
Attain Requirement
tailings ponds will comply
with Chapter 515-19-53
which establishes the
design standards for a final
cover. Any alternative
design will require the
approval of EPA.
Page 6 of 6
-------
Table 14: Matrix of Cost and Effectiveness Data
Relevant Considerations for Cost-Effectiveness Determination:
• Volume of Source Material is estimated at 50 million cubic yards
• Risk due to exposure of lead in Source Material predicts 22.3% of adolescents would have blood-lead levels exceeding 10ug/dL.
Alternative
(check box if cost effective)
Present Worth
Cost
Incremental Cost
Compared to
Preceding
Alternative
Long-Term
Effectiveness and
Permanence
Reduction of TMV
Through Treatment
Short-term
Effectiveness
1) No Action ~
$0
• No reduction in
long-term risk to
human health and
the environment
• 4220 acres of
land with Source
Material
Not applicable
• No short-term
protection for the
community.
4) Phased Consolidation 0
and On-Site Disposal
$167,735,000
+$167,735,000
t Achieves RAOs for
all Source Material
areas
t 322 acres subject
to ICs for long-term
control
Not applicable
t Majority of
residents not
protected until 20th
yr.
5) Voluntary Relocation, 0
Phased Consolidation and
On-Site Disposal
$167,288,000
-$447,000
«-~ Achieves RAOs
for all Source
Material areas
<-~ 322 acres subject
to ICs for long-term
control
Not applicable
t Majority of
residents protected
following relocation
in 3 years.
8) Total Source ~
Consolidation and On-Site
Disposal
$255,909,000
+$88,621,000
++ Achieves RAOs
for all Source
Material areas
i 846 acres subject
to ICs for long-term
control
Not applicable
i Majority of
residents not
protected until 20th
yr.
COST-EFFECTIVENESS SUMMARY: (Summary of individual cost-effectiveness evaluations and relative cost-effectiveness determinations)
• Alternatives 1 and 8 are not considered to be cost-effective
• While Alternative 4 and 5 are considered to be cost-effective, Alternative 5 provides a potentially greater return on investment.
Key: • = Baseline characteristic i = less "effective" than preceding alternative
t = More "effective" than preceding alternative «-~= No change compared to preceding alternative
------- |