EPA/ROD/R10-94/073
January 1994
EPA Superfund
Record of Decision:
Radioactive Waste Management
Complex, Idaho Falls, ID
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DECLARATION FOR PAD A
AT THE RADIOACTIVE WASTE MANAGEMENT COMPLEX
SUBSURFACE DISPOSAL AREA
AT THE IDAHO NATIONAL ENGINEERING LABORATORY
Idaho Falls, Idaho
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DECLARATION OF THE RECORD OF DECISION
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SITE NAME AND LOCATION
At
Pad A
Radioactive Waste Management Complex
Subsurface Disposal Area
Idaho National Engineering Laboratory
Idaho Falls, Idaho
STATEMENT OF BASIS AND PURPOSE
This document presents the selected remedial action for Pad A, which was chosen in
accordance with the Comprehensive Environmental Response, Compensation, and Liability
Act (CERCLA) as amended by the Superfund Amendments and Reauthorization Act (SARA),
and is consistent, to the extent practicable, with the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP). This decision is based on the Administrative Record for
the Pad A Remedial Action.
The U.S. Environmental Protection Agency (EPA) approves of this remedy and the
State of Idaho concurs with the selected remedial action.
ASSESSMENT OF THE SITE
Threatened releases of hazardous substances from this Site, if not addressed by
implementing the response action selected in this Record of Decision (ROD), may present a
potential threat to public health, welfare, or the environment. Implementation of the remedial
action selected in this ROD will provide recontouring, maintenance, monitoring of the cover,
and institutional controls at Pad A to ensure effectiveness of the existing cover and to .
minimize potential future exposure and migration of contaminants from the pad. If
contaminants from Pad A were to migrate from the pad, they may potentially contaminate the
subsurface area or groundwater. '
DESCRIPTION OF THE SELECTED REMEDY
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This ROD addresses Pad A at the Radioactive Waste Management Complex (RWMC) ,
Subsurface Disposal Area (SDA), at the Idaho National Engineering Laboratory (INEL). The
RWMC has been designated as Waste Area Group (WAG) 7 of the 10 WAGs at the INEL
that are underliivestigation pursuant to the Federal Facility Agreement and Consent Order
(FF AlCO) betWeen the Idaho Department of Health and Welfare (IDHW), the Environmental
Protection Agency (EPA), and the U.S. Department of Energy Idaho Operations Office
(DOE-ID). Pad A, designated Operable Unit (OU) 7-12, is located within WAG 7. The
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selected remedy for Pad A will provide for soil cover contouring and slope cocrection, routine
maintenance, and monitoring. The function of this remedy would be to reduce the risks
associated with potential exposure to and migration of the contaminated wastes.
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The major componentS of the selected remedy include:
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RecontOuring and slope cocrection of the existing Pad A soil cover, followed by
maintenance, including subsidence and erosion control, to ensure effectiveness.
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MonitOring of groundwater, soil, surface water, and air to provide early detection of
a potential release from Pad A to the subsurface, groundwater, or surface pathways.
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Maintaining institutional controls, including maintaining existing signs and postings,
restricting access, and maintaining existing fenceslbaniers. It is presumed that
institutional controls would remain in place indefinitely and this presumption will be
reviewed every 5 years.
STATUTORY DETERMINATION
The selected remedy is protective of human health and the environment, complies with
Federal and State applicable or relevant and appropriate requirements (ARARs), and is cost-
effective. This remedy utilizes permanent solutions and alternative treatment technologies to
the maximum extent practicable for this site; however, because the wastes can be reliably
controlled in place, treatment of the principal sources of contamination was not found to be
necessary. Therefore, this remedy does not satisfy the statutory preference for treatment as a
principal element of the remedy.
Because this remedy will result in hazardous substances remaining onsite above health-
based levels, a review will be conducted within two years after commencement of remedial
action, and every five years thereafter~ to ensure .that the remedy continues to provide
adequate protection of human health and the environment.
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Signature sheet for the foregoing Pad A located in the Subsurface Disposal Area of the
Radioactive Waste Management Complex at the Idaho National Engineering Laboratory
Record of Decision between the U.S. Department of Energy and the Environmental Protection
Agency, with concwrence by the Idaho Department of Health and Welfare.
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GERALD A. EMISON
Acting Regional Administrator, Region 10
U.S. Environmental Protection Agency
Date
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Signature sheet for the foregoing Pad A located in the Subsurface Disposal Area of the
Radioactive Waste Management Complex at the Idaho National Engineering Laboratory.
Record of Decision betWeen the U.S. Department of Energy and the Environmental Protection
Agency, with .concwrence by the Idaho Department of Health and Welfare.
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AUGUSTINE A. PITROLO
Manager
U.S. Department of Energy, Idaho Operations Office
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Signature sheet for tJ1e foregoing Pad A located in the Subsurface Disposal. Area of the
Radioactive Waste Management Complex at the Idaho National Engineering Laboratory.
Record of Decision betWeen the U.S. Department of Energy and the Environmental Protection
Agency, with ~oncurrence by the Idaho Department of Health and Welfare.
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JERRY L. HARRIS
Director
Idaho Department of Health and Welfare
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Date'
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CONTENTS
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DE CLARA T10N OF THE RECORD OF DECISION
. . . . . . . . . . . . . . . . . . . . . . . . . .. 1
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SITE NAME AND LOCATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. i
STATEMENT OF BASIS AND PURPOSE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. i
ASSESSMENT OF THE SITE ........................................... i
DESCRIPTION OF THE SELECTED RE!vfEDY ............................... i
STATUTORY DETERMINATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ii
SIGNATURE PAGES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. iii
DECISION SUMMARY. . . . . . . . . . . . " . . . . . .. . ..... . . . . . . . . . . . . . . . . . . . .. 1
1. SITE NAME, LOCATION AND DESCRIPTION. . . . . . . . . . . . . . . . . . . . . .. 1
2. SITE mSTORY AND ENFORCEMENT ACTIVITIES. . . . . . . . . . . . . . '.' .. 4
3. HIGID..IGHTS OF COMMUNITY PARTICIPATION. . . . . . . . . . . . . . . . . . .. 5
4. SCOPE AND ROLE OF OPERABLE UNIT AND RESPONSE ACTION. . . . .. 8
5. SUMMARY OF SITE CHARACTERISTICS. . . . . . . . . . . . . . . . . . . . . . . . .. 8
5.1
Summary of Environmental Monitoring -Data.. . . . . . . . . . . ... . . . . . . .. 11
5.1.1 Surface Water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11
5.1.2 Soil.............................. ;.. . . . . . . . . . . .. 14
5.1.3 Groundwater...................................... 21
5.1.4 Biotic........................................... 21
5.2
Pad A Soil Overburden Sampling and Drum Retrieval Activities. . . . . . .25
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6. SUMMARY OF SITE RISKS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 29
6.1
Human Health Risks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 29
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6.1.1 Identification of Contaminants of Concern. . . . . . . . . . . . . . . .. 30
6.1.2 Exposure Assessment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 30
6.1.3 Toxicity Assessment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ~ 35
6.1.4 Risk Characterization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 36
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7.
6.1.5
6.2
Uncertainty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., 37
Ecological Concerns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38
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6.2.1
6.2.2
6.3
Exposure Assessment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38
Risk Characterization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38
Basis for Response. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 44
If
DESCRIPTION OF AL TERNA TIVES """""""""""""'" 44
8.
7.1
Remedial Action Objectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 44
7.2
Summary of Alternatives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 46
7.3
Alternative 1 - Containment of Pad A Materials. . . . . . . . . . . . . . . . . .. 46
7.4
Alternative 2 - Limited Action. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 49
7.5
Alternative 3 - No Action. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 49
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES. . . . . .. 50
9.
8.1
Threshold Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 50
8.1.1
8.1.2
8.2
Overall Protection of Human Health and the Environment. . . . .. 50
Compliance with ARARs ............................. 50
Balancing Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 51
8.2.1
8.2.2
8.2.3
8.2.4
8.2.5
8.3
Long-term Effectiveness and Permanence. . . . . . . . . . . . . . . . .. 51
Reduction of Toxicity, Mobility, or Volume through Treatment. .. 52
Short-term Effectiveness. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 52
Implementability ................................,.. 52
Cost. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 53
Modifying Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 53
8.3.1
8.3.2
State Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., 53
Community Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 54
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SELECTEDRE11EDY """""""""""""""""""" 54
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9.1
Limited Action Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 54
9.2
Remediation Goals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 55
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9.3
Estimated Costs for the Selected Remedy. . . . . . . . . . . . . ., "
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10. STATUTORY DETERMINATIONS. . . . . . . . . . . . . . . " . . . . . . , .
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1 0.1 Protection of Human Health and the Environment. . . . . . . . . . , . .
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10.2 Compliance with ARARs ...........................,
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10.2.1 Chemical-specific ARARs . . . . . . . . . . . . . . . . . . . . . . . . , , . .' 5t~
10.2.2 Action-specific ARARs ........................... " :'~:
10.2.3 Location-specific ARARs .......................... .. 5g
10.2.4 To-Be-Considered Guidance. . . . . . . . . . . . . :. . . . . . . . . .:')8
10.3 Cost Effectiveness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .', ,="1
10.4 Use of Permanent Solutions and Alternative Treatment
Technologies to the Maximum Extent Practicable. . . . . . . . . . . . '
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10.5 Preference for Treatment as a Principal Element. . . . . . . . . . . . . . . ' .. .)'1
11. DOCUMENTATION OF SIGNIFICANT CHANGES. . . . . . . . . . . . . . . .
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APPENDIX A - RESPONSIVENESS SUMMARY. . . . . . . . . . . . . . . . . . . . . .. .
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APPENDIX B - PUBLIC COMMENT/RESPONSE LIST INDEX. . . . . . . . . . . . ,
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APPENDIX C - ADMINISTRATIVE RECORD INDEX ....................., . , c-]
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FIGURES
1.
The Rac;iioactive Waste Management Complex at the INEL. . . . . . . . . . . . . . . . . . .. 1
2.
RWMC and associated spreading areas at the INEL. ........................ 3
3.
Schematic representation of Pad A waste placement. ... . . . . . . . . . . . . . . . . . . . .. 9
4.
Pad A plan view. ................................................ 9
5.
TSNSDA surface water sampling locations. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13
6.
Pad A sampling locations and designated RWMC areas for soil. .-. . . . . . . . . . . .. 18
7.
Pad A soil and water nitrate sampling locations. . . . . . . . . . . . . . . . . . . . . . . . .. 22
8.
Well locations. .................................................. 24
9.
1979 Pad A penetration locations (at points A & B) ....................... 26
10.
1988 sampling locations for the Pad A initial penetration. . . . . . . . . . . . . . . . . . .. 27
11.
Cross-sections of composite earthen material cover options. . . . . . . . . . . . . . . . .. 48
TABLES
1.
Estimated chemical masses in Pad A. ................................. 11
2.
Pad A specific nuclide radioactivity by year in curies froni RWMIS~ .. -. . . . . . . . . .. 12
3.
Surface water results at the Pad A from 1980 and 1982 . . . . . . . . . . . . . . . . . . . .. 15
4.
Surface water results at Pad A from 1983 to 1985 . . . . . . . . . . . . . . . . . . . . . . . .. 16
5.
Nitrate concentrations in Pad A runoff water (1980 to 1986) . . . . . . . . . . . . . . . . .. 17
6.
Activity concentrations in Pad A soils (1984 to 1988) ...................... 19
7.
Nitrate c-encentrations in Pad A soils (1979 to 1984) . . . . . . . . . . . . . . . . . . . . . .. 23
8.
Cover soils sample analysis for inorganics .............................. 28
9.
Summary of risks from Pad A ...................................... 33
10.
Exposure parameters used in the exposure assessment of contaminants at Pad A . . .. 34
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11.
Reference doses used to' evaluate noncarcinogenic effects of contaminants
at Pad A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 36
12.
Slope factors (SFs) used to evaluate carcinogenic effects of radionuclides
at Pad A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . .. 37
13.
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Pad A estimates of conservatism in the baseline risk assessment. . . . . . . . . . . . . .. 39
14.
Summary of ARARs and TEC criteria for Pad A alternatives. . . . . . . . . . . . . . . .. 47
15.
Evaluation of alternatives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 51
16.
Pad A alternative cost estimates (in present dollar value) . . . . . . . . . . . . . . . . . . .. 53
17.
Limited action detailed cost estimate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 58
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#
ARARs
BRA
CAM
CERCLA
CFR
COCA
DOE
DOE-ID
EA
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EBR
ACRONYMS
Applicable or Relevant and Appropriate Requirements
. Baseline Risk Assessment
Continuous Air Monitor
Comprehensive Environmental Response, Compensation. and Liability Act
Code of Federal Regulations
Consent Order Compliance Agreement
U.S. Department of Energy
U.S. Department of Energy, Idaho Operations Office
Environmental Assessment
Experimental Breeder Reactor
EG&G Idaho EG&G Idaho, Inc.
EIS Environmental Impact Statement
EP A U.S. Environmental Protection Agency
ER&WM Environmental Restoration and Waste Management
ESRP Eastern Snake River Plain
FF AlCO Federal Facility Agreement and Consent Order
FR Federal Register
IDHW Idaho Department of Health and Welfare
INEL Idaho National Engineering Laboratory
LLW
MCL
NCP
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NEPA
NPL
NPV
NRF
NRC
OU
RCG
RCRA
-,
Low-level Waste
Maximum Contaminant Level
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National Oil and Hazardous Substances Pollution Contingency Plan
National Environmental Policy Act
National Priorities List
Net Present Value
~~~al Reactor Facility
U.S. Nuclear Regulatory Commission
Operable Unit
Radiation Concentration Guide
Resource Conservation and Recovery Act
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RFP Rocky Rats Plant
RI Remedial Investigation
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RIfFS Remedial InvestigationlFeasibiliry Study
ROD Record of Decision
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RWMC Radioactive Waste Management Complex
RWMIS Radioactive Waste Management Infonnation System
SARA Superfund Amendments and Reauthorization Act
SDA Subsurface Disposal Area
SF Slope Factor
SRPA Snake River Plain Aquifer
TBC T 0- Be-Considered
TDA Transuranic Disposal Area
TRA Test Reactor Area
TRU Transuranic
TRA Transuranic Storage Area
USGS United States Geological Survey
VOC V olatile Organic Compound
WAC Waste Acceptance Criteria
WAG Waste Area Group
WIPP Waste Isolation Pilot Plant
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DECISION SUMMARY
1. SITE NAME, LOCATION, AND DESCRIPTION
The Idaho National Engineering Laboratory (INEL) is a government facility managed
by the U.S. Department of Energy (DOE) located 51.5 km (32 mi) west of Idaho Falls, Idaho,
and occupies 2305 km2 (890 mi2) of the northeastern portion of the Eastern Snake River
Plain. The Radioactive Waste Management Complex (RWMC) is located in the southwestern
portion of the INEL (Figure I). Pad A is located in the north-central portion of the
Subsurface Disposal Area (SDA) and is approximately 73.2 x 102.1 m (240 x 335 ft). The
SDA is a 35.6-ha (88-acre) area located within the RWMC.
Current land use at the INEL is primarily nuclear research and development and waste
management. Surrounding areas are managed by the Bureau of Land Management for
multipurpose use. The developed area within the INEL is surrounded by a 1295-km2
(500-mi2) buffer zone used for cattle and sheep grazing.
Of the 11,700 people employed at the INEL, approximately 100 are employed at the
RWMC. The nearest offsite populations are in the cities of Atomic City [19.2 kIn (12 mi)
southeast of RWMC], Arco [25.7 kIn (16 mi) northwest], Howe [30.6 kIn (19 mi) north],
Mud Lake [58 kIn (36 mi) northeast], and Terreton [59.5 km (37 mi) northeast].
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Pad A- -
RWMC
o Jdabo Falls
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Figure 1. The Radioactive Waste Management Complex at the INEL.
The INEL property is located on the northeastern edge of the Eastern Snake River
Plain (ESRP), a volcanic plateau, that is primarily composed of silicic and basaltic rocks and
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relatively minor amounts of sediment. Underlying the RWMC are series of basaltic lava
flows with sedimentary interbeds. The basalts immediately beneath the Site are relatively flat
and covered by 6.1 to 9.1 m (20 to 30 ft) of alluvium.
,.
The depth to the Snake River Plain Aquifer (SRPA) underlying the INEL varies from
61 m (200 ft) in the northern portion to 274.3 m (900 ft) in the southern portion of the INEL.
The depth to the aquifer at the RWMC is 176.8 m (580 ft). Regional groundwater flow is
generally to the southwest.
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The INEL has semidesert characteristics with hot summers and cold winters. Normal
annual precipitation is 23.1 cmlyr (9.1 in./yr), with estimated evapotranspiration of 15.2 to
22.8 cmlyr (6 to 9 in./yr). The only surface water present at the INEL is the Big Lost River,
which is approximately 1.5 mi northwest of the RWMC; however, due to the arid nature of
the INEL, this river is typically dry and contains no running water. Surface water is present
at the RWMC only during periods of heavy rainfall and snowmelt, which generally occur in
January through April.
To minimize the potential for surface water to flow onto the RWMC during periods of
high surface water runoff at the INEL, water is diverted from the RWMC via spreading areas
and associated dikes, located to the west and south of the RWMC (Figure 2). To further
enhance surface water diversion from the pits and trenches, berms have also been constructed
immediately around the SDA.
Twenty distinctive vegetative cover types have been identified at the INEL, with big
sagebrush the dominant species, covering approximately 80% of ground surface. The variety
of habitats on the INEL support numerous species of reptiles, birds, and mammals. Several
bird species at the INEL that warrant special concern because of sensitivity to disturbance or
their threatened status include the ferruginous hawk (Buteo regalis), bald eagle (Haliaeetus
leucocephalus), prairie falcon (Falco mexicanus), peregrine falcon (Falco peregrinus), merlin
(Falco columbarius), long-billed curlew (Numenius americanus) and the' burrowing owl
(Athlene cunicularia). The ringneck snake, whose'occurrence is considered to be INEL.:wide,
is listed by the Idaho Department of Fish and Game as a Category C sensitive species.
The RWMC encompasses 58.3 ha (144 acres) [0.59 km2 (approximately 0.23 mi2)] and
consists of two main disposal and storage areas: (a) Transuranic (TRU) Storage Area and (b)
the SDA. Within these areas are smaller, specialized disposal and storage areas.
Approximately 10,200 m3 (13,341 yds3) of containerized solid wastes were placed on a
73.2 x 102.1 m (240 x 335 ft) asphalt pad, known as Pad A, at the SDA from September
1972 to August 1978. The asphalt pad is approximately 5.6 to 6.1 cm (2 to 3 in.) thick. The
depth from the-bottom of the asphalt pad to the underlying basalt ranges from 0.3 to 3.7 m (1
to 12 ft). Pad A presently has a soil cover that averages about 1.2 m (4 ft) thick.
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Figure 2. RWMC and associated spreading, areas at the INEL.
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2. SITE HISTORY AND ENFORCEMENT ACTIVITIES
The RWlv1C was established in the early 1950s as a disposal site for solid, low-level
waste (LL W)generated by INEL operations. Within the RWMC is the SDA where hazardous
substances (radioactive and hazardous waste) have been disposed in underground pits,
trenches, soil vault rows, and Pad A-an aboveground pad. TRlJ waste was disposed in the
SDA from 1952 to 1970 and was received from the Rocky Flats Plant (RFP) for disposal in
the SDA from 1954 through 1970. The RFP is a DOE-owned facility located west of Denver,
Colorado, and was used primarily for the production of plutonium components for nuclear
weapons. Also located in the RWMC is the Transuranic Storage Area (TSA) where interim
storage of TRU waste occurs in containers on asphalt pads. The TSA accepted TRlJ waste
from offsite generators for storage from 1970 through 1988. TRU waste generated at the
INEL is still received and stored in the TSA. The location of Pad A within the SDA is
shown in Figure 1.
.
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Since 1970, solid TRU waste received at the RWMC has been segregated from non-
TRU solid waste and placed into the interim retrievable storage at the TSA. RWlv1C LL W
that is contaminated with TRU isotopes less than or equal to 100 nanocuries per gram
(~100 nCi/g) but greater than 10 nanocuries per gram (>10 nCi/g) is excluded by DOE's
Waste Acceptance Criteria (WAC) from disposal at the RWMC and is placed in interim
storage at the RW1v1C. LLW contaminated with TRU isotopes :::;10 nCi/g is disposed of in
the SDA. All but tWo shipments of waste disposed of on Pad A are classified as LL W (i.e.,
<100 nCi/g); the other tWo shipments contained waste with TRU radionuclide concentrations
> 100 nCi/g. One shipment consisted of eight drums with a total loading of 583.2 nCi/g, and
the second shipment consisted of tWo drums with a total loading of 108.6 nCi/g. No waste
disposal has occurred on Pad A at the SDA since its closure in 1978.
A Consent Order and Compliance Agreement (COCA) was entered into betWeen DOE
and the U.S. Environmental Protection Agency (EPA) pursuant to Resource Conservation and
Recovery Act (RCRA) Section 3008(h) in August 1987. The COCA required DOE to
conduct an initial assessment and screening of all solid waste and/or hazardous waste disposal
units at the INEL, and set up a process for conducting any necessary corrective actions.
On July 14, 1989, the INEL was proposed for listing on the National Priorities List
(NPL) [54 Federal Register (FR) 29820]. The listing was proposed by the EPA under the
authorities granted EPA by the Comprehensive Environmental Response, Compensation and
Liability Act of 1980 (CERCLA) as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA). The final rule that listed the INEL on the NFL was
published on November 21, 1989, in 54 FR 44184.
.
As a resuft of the INEL's listing on the NPL in November 1989, DOE, EPA, and the
State of Idaho Department of Health and Welfare (IDHW) entered into the Federal Facility
Agreement and Consent Order (FEAJCO) on December 9, 1991.
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..'
Pad A was identified for a Remedial InvestigationlFeasibility Study" (RIlFS) under the
FFA/CO. This Record of Decision (ROD) documents the results of the RIlFS and the remedy
selected. The entire RWMC will be evaluated in the Waste Area Group 0N AG) 7
Comprehensive RIlFS which is scheduled to begin no later than July 1996.
I '.
3. HIGHLIGHTS OF COMMUNITY PARTICIPATION"
In accordance with CERCLA ~ 113(k)(2)(B)(i-v) and 117, a series of opportunities for
public information and participation in the remedial investigation and decision process for Pad
A were provided over the course of 21 months beginning in November of 1991 and
continuing through August 1993. For the public, the activities ranged from receiving a fact
sheet, INEL Reporter articles and updates, and a proposed plan, to having a telephone
briefing, four public scoping meetings, three public meetings, and two open houses to offer
verbal or written comments during two separate 30-day public comment periods:
On Novembc:r 19, 1991, a fact sheet concerning Pad A was conveyed through a "Dear
Citizen" letter to a mailing list of 5,600 individuals of the general public and 11,700 INEL
employees in advance of the public scoping meetings scheduled in early December. On
November 20, the DOE issued a news release to more than 40 news media cont~ctS .
concerning the beginning of a 30-day public scoping comment period, which ended January 3,
1992, on the Pad A remedial investigation. Both the letter and release gave notice to the
public that Pad A documents would be available before the beginning of the comment period
in the Administrative Record section .of the INEL Information Repositories located in the
INEL Technical Library of Idaho Falls, as well as in city libraries in Idaho Falls, Pocatello,
Twin Falls, Boise, and Moscow. Display ads announcing the same information appeared in
eight major Idaho newspapers. Large ads appeared in the following newspapers from
November 22 to the 27: Post Register (Idaho Falls); Idaho State Journal (Pocatello); South
Idaho Press (Burley); Times News (Twin Falls); Idaho Statesman (Boise); Idaho Press
Tribune (Nampa); Lewiston Morning Tribune (Lewiston); and Idahonian .(Moscow).
..
Sirnilar display ads concerning upcoming meetings appeared in each of these
newspapers several days preceding each local meeting to encourage citizens to attend and
provide verbal or written comments. All three media-the Dear Citizen l~tter, news release,
and newspaper ads-gave public notice of four scoping meetings concerning the beginning of
the investigation at Pad A and the beginning of a 30-day public comment period that was to
begin December 4, 1991. Additionally, two radio stations in Idaho Falls and newspapers in
Idaho Falls and other communities repeated announcements from the news release to the
public at large. A total of seven radio advertisements were made by local stations where
meetings were scheduled several days before and the day of the meetings. .
~
PersonaI-phone calls concerning the availability of Pad A documents and public
meetings were made to individuals, environmental groups, and organizations by INEL
Outreach Office staff in Pocatello, Twin Falls, and Boise. The Community Relations Plan
Coordinator made calls in Idaho Falls and Moscow.
Scoping meetings on Pad A were held in conjunction with scoping the remedial .
investigation of the organic contamination in the vadose zone, and an informational discussion
-------
on the Pit 9 proposed plan, all of which were projects from WAG 7 at the RWMC. The
meetings were held December 9, 10, 11, and 12, 1991 in Boise, Moscow, Twin Falls, and
Idaho Falls respectively. An informal open house was held one hour prior to each of the
meetings to allow the public to visit with State and Federal representatives about Pad A.
"
During the meetings that followed, representatives from DOE and INEL discussed the
project, answered both written and verbal questions, and received public comments. Written
comment forms were distributed at the meetings. Comments from the scoping meetings were
evaluated and considered as part of the RIfFS process.
. ~
Regular reports concerning the status of the Pad A project were included in the INEL
Reporter and mailed to those who attended the meetings and who were on the mailing list.
ReportS appeared in the March, May, July, and November 1992; and the January, March, and
July 1993 issues of the INEL Reporter. During this time the number of individuals on the
mailing list increased to 6,600. Individuals on the mailing list, those who attended the
meetings, and all INEL employees received issues of the INEL Reporter.
Opportunities for public involvement in the decision process for Pad A were provided
beginning in July 1993. For the public, the activities ranged from receiving the proposed
plan, conducting one teleconference call, and attending open houses and public meetings to
informally discuss issues and offer verbal and written comments to the agencies during the
30-day public comment period.
On July 19, 1993, DOE-ill issued a news release to more than 40 news media contacts
concerning the beginning of a 30-day public comment period on the Pad A proposed plan.
The release also gave notice to the public that Pad A documents would be available before
the beginning of the comment period in the Administrative Record section of the INEL
Information Repositories located in the INEL Technical Library in Idaho Falls, the Shoshone-
Bannock Library at Fort Hall, the University of Idaho Library in Moscow, the Idaho State
Library in Boise; as well as in city libraries in Idaho Falls, Pocatello, Twin Falls, Boise, and
Moscow.
Copies of the proposed plan for Pad A were mailed to 6,600 individuals on the INEL
Community Relations Plan mailing list on July 28, 1993 urging citizens to comment on the
plan and to attend public meetings. Display ads announcing the same information and the
location of open houses in Pocatello and Twin Falls, and public meetings in Idaho Falls,
Boise, and Moscow appeared in seven major Idaho newspapers. Large ads appeared in the
following newspapers from July 15 to 20: Post Register (Idaho Falls), Idaho State Journal
(Pocatello), SOLlth Idaho Press (Burley), Times News (Twin Falls), Idaho Statesman (Boise),
Lewiston Mo_rning Tribune (Lewiston), and The Daily News (Moscow).
-
Similar display ads concerning upcoming meetings appeared in each of these
newspapers several days preceding each local open house or meeting to encourage citizens to
attend and provide verbal or written comments. Both media, the news release and newspaper
ads, gave public notice of public involvement activities and offerings for briefings, and the
beginning of a 30-day public comment period that was to begin July 28 and run through
August 26, 1993. Additionally, radio stations in Idaho Falls, Blackfoot, Pocatello, Burley,
.
-------
and Twin Falls ran advertisements during the three days prior to the open houses in Pocatello
and Twin Falls.
'.
'"
The open houses were held in Pocatello and Twin Falls on August 11 and 12, and the
public meetings were held in Idaho Falls, Boise, and Moscow on August 17, 18, and 19,
1993. Written comment forms, including a postage-paid business reply form, were made
available to those anending the meetings. The forms were used to turn in wrinen comments
at the meeting, and by some, to mail in comments later. The reverse side of the meeting
agenda contained a form for the public to evaluate the effectiveness of the meetings. A court
reporter was present at each meeting to keep a verbatim transcript of discussions and public
comments. The meeting transcripts were placed in the Administrative R-ecord section for
Pad A, Operable Unit 7-12, in eight INEL Information Repositories.
On August 10, 1993, a teleconference call between the League of ' Woman Voters of
Moscow and the Environmental Defense Institute, DOE-ID, EP A, and the IDHW concerning
the Pad A proposed plan was conducted at the request of Moscow area residents. The call
consisted of an overview of the proposed plan, questions and answers, and general discussion
of Pad A issues.
Personal phone calls concerning the availability of the proposed plan and the public
meetings were made to individuals, environmental groups, and organizations by the INEL
Community Relations Plan Coordinator. Outreach Office staff made calls to citizens in
northern, southwestern, and southeastern Idaho. ' '
Another series of ads were placed in the same local papers several days before the
public meetings to encourage citizens to attend and comment on the plan. Addinonally, a
special feature article in the July issue of the INEL Reporter was mailed to 6,600 individuals
to remind citizens about the meetings and the opportunity to comment on the proposed plan.
A Responsiveness Summary has been prepared as part of the Record of Decision. All
formal verbal comments, as given at the public meetings, and all written comments, as '
submitted, are repeated verbatim in the Administrative Record for the Record of Decision.
Those comments are annotated to indicate which response in the Responsiveness Summary
addresses each comment.'
~
A total of 42 people attended the Pad A public meetings. Overall, 22 provided formal
comments; of these 22 people, 10 people provided oral comments and 12 people provided
written comm~ntS. This resulted in a total number of 109 comments. All comments received
on the proposed plan were considered during the development of this ROD. The decision for
this action is based on the information in the Administrative Record for this operable unit
(OU).
.,
4. SCOPE AND ROLE OF OPERABLE UNIT AND RESPONSE ACTION
Under the FFNCO, the INEL is divided into ten WAGs. The WAGs are further
divided into OUs. The RWMC has been designated WAG 7 and consists of 14 OUs. Data
from shipping records, along with process knowledge, written correspondence, and existing
-------
monitOring data. were available to allow Pad A to be evaluated in an expedited manner.
Therefore. Pad A was designated as an OU to accelerate a RIfFS. Pad A. OU 7-12, consists
of the asphalt pad, the waste pile, and the overlying soil cover.
,
A complete evaluation of all cumulative risks associated with CERCLA actions at
WAG 7 will be conducted as parr of the WAG 7 Comprehensive Rl/FS (OU 7-14) to ensure
all risks have been adequately evaluated. Conducting this remedial action is parr of the
overall WAG srrategy and is expected to be consistenr with any planned furure actions.
.. ~
5. SUlVIMARY OF SITE CHARACTERISTICS
Pad A was constructed in 1972 for disposal of packaged solid mixed waste (hazardous
waste contaminated with radioactive material) primarily from the Rocky Flats Plant in
Colorado. The waste was packaged in 18,232 55-gal drums, and 2,0204 x 4 x 7 ft plywood
boxes which were placed at Pad A from September 1972 until August 1978. Each container
had at least one polyethylene liner, with most containing double liners. Waste was carefully
stacked on the pad with the drums reaching a maximum of 11 high, and boxes stacked a
maximum of 5 high (Figure 3). At the completion of container placement activities,
approximately 40% of the total pad area was occupied by waste materials.
Closure of Pad A was performed by placing plywood and/or polyethylene over the
exposed containers. Both types of covering were placed in some areas, and other areas had
no covering. The waste pile was then covered with a soil layer 0.9 m (3 ft) to 1.8 m (6 ft) in
thickness (Figure 4). After the cover was completed, the area was seeded with crested
wheatgrass to minimize soil erosion.
Environmental monitOring has been conducted to detect contaminant migration from
Pad A since 1978 and has included the monitoring of surface water, groundwater, soil, and
biota. Although these monitoring activities were conducted as parr of routine monitoring
activities at the RWMC, no conclusive rrends for contaminant migration were identified for
Pad A.
In addition to the environmental monitoring program, investigations of Pad A wastes
were conducted prior to the initiation of FF NCO activities. This included an investigation
between September 26 and October 12, 1979, to determine the condition of the buried drums
and plywood boxes. Another investigation in 1989 included determining the extent of
radiological contamination on the external surfaces of the uncovered drums. Results of
laboratory countS did not indicate that radioactive contamination was present on or near the
drums. This investigation also involved surveying for volatile organic compounds (VOCs)
and sampling for' beryllium and nitrates. The intent of these programs was to determine
whether any gross migration of contaminants or large-scale failure of the cover was occurring
at Pad A.
",.
.
The composition of Pad A wastes was identified based on written correspondence and
process knowledge from the RFP, the major source of Pad A wastes, as well as information
from RFP shipping and INEL disposal records contained in the Radioactive Waste
-------
Schematic Representation of Pad A
Waste Placement
(Not Drawn to Scale)
f
24 ft
~~t 1
Gravel
Surficial
Sediment
Basalt
/ ~ Over?urdenl
Figure 3. Schematic representation of Pad A waste placement.
E:J SS GAL DRUMS
- 4X4X7BOXES
o 60 120
I .
Appro,um:ue Sc::IIIe (feet)
Asphalt Pad
N
t
Figure 4. Pad A plan view.
-------
Management Information System (RWMIS). The RWMIS was initiated in 1971 and is
considered to be the official INEL record for solid radioactive wastes.
~
Pad A wastes are primarily composed of nitrate salts, depleted uranium waste, and
sewer sludge. Wastes, totaling approximately 10,200 m3 (13,341 yd3), at Pad A consist of:
.
.
Approximately 7,250 m3 (9,483 yd3) of evaporator salts from the RFP
contaminated with transuranic radionuclides
.
Approximately 2,250 m3 (2,943 yd3) of waste consisting primarily of oxides of
uranium, uranium casting wastes, beryllium foundry wastes, and machining
wastes from RFP (hereinafter referred to as depleted uranium and beryllium
foundry wastes)
.
Dry sewage sludge from the RFP contaminated with low levels of TRU
radionuclides
.
Miscellaneous INEL-generated radioactive wastes such as lab waste, counting
sources, and uranium standards.
The evaporator salts are primarily sodium nitrate and potassium nitrate (60% sodium
nitrate, 30% potassium nitrate, 10% miscellaneous). The nitrates at Pad A have been
reviewed against 40 Code of Federal Regulations (CPR) 261.21(a)(4) and 49 CPR .173.151
and appear to exhibit the properties of an oxidizer. It is recognized that this type of oxidizer
can have the characteristic of ignitability. Radioactive contamination includes plutonium,
americium, thorium, uranium, and potassium40. .
Miscellaneous wastes at Pad A include other inorganic salts, dirt, concrete, and other
materials. Approximately 4,600,000 kg (10,143,000 lbs) of inorganic salt,s from Rocky Flats
are contained in 1,275 plywood boxes and 15,400 drums according to information from the
RWMIS. The total inorganic salt waste consists of approximately 60% sodium nitrate
(NaN03), 30% potassium nitrate (KN03), and 10% chloride, sulfate, and hydroxide salts.
Based on RWMIS information, the volume of salts in the containers noted above comprises
71 % of the total waste volume in Pad A.'
Using RWMIS data, the depleted uranium waste received from RFP comprises
approximately 2,250 m3, which is 22% of the total waste volume stored in Pad A. The
'remaining 7% of the total waste volume is made up of the miscellaneous wastes and sludges.
The chemical form and mass of the chemical contaminants on Pad A are shown in Table 1.
The mass of uranium is based on 72,400 kg (159,642 lb) of total uranium, which is derived
from the speCIfic' radioactivity of the three uranium isotopes listed in Table 2. This number is
then converted to the triuranium octaoxide (U30s) chemical mass. The U30s chemical form is
the stable oxide form from uranium that was incinerated at the RFP before shipment to INEL.
~
.
-------
Table 1. Estimated chemical masses in Pad A.
~
Mass
Chemical (kg) (lb)
. Sodium nitrate (NaN03) 2.7E+06 5.95E+06
Potassium nitrate (KL'\l03) 1.4E+06 3.09E+06
Sodium chloride (NaCI) l.OE+05 2.20E+05
Potassium chloride (KCI) 5.1E+04 1. 12E+05
Sodium sulfate (N~SO~) 1.0E+05 2.20E+05
Potassium sulfate (K2S04) 5.1E+04 1. 12E+05
Sodium hydroxide (NaOH) 1.0E+05 2.20E+05
Potassium hydroxide 5.IE+04 1. 12E+05
(KOH)
Triuranium octaoxide 8.75E+04 1.93E+05
(U30g)
..,
Table 2 displays the specific radioactivity for each radionuclide in curies on an annual
basis from 1972 to 1978. The data used are those supplied by individual shipping records
from the RFP that were entered into the RWMIS. The annual data listed for each,
radionuclide represent total quantities received for each year without decay corrections during
that year. The total radioactivity for each radionuclide from 1972 to 1978 is displayed
without any decay corrections. The total of nuclide radioactivity in curies from the RWMIS
is 3.892E+Ol.
5.1 Summary of Environmental Monitoring Data
Sampling and monitoring activities "of Pad- A were 'conducted'prior to . the initiation of"
any FF AlCO investigations. Based on the evaluation of these 'data, no additional sampling
was required to complete the Pad A remedial investigation. Rather, the Pad A investigation
in effect consisted of the re~onstrUction and documentation of existing records and data.
5.1.1 Surface Water
..
Monitoring of surface water at Pad A began in 1974, when surface water samples
were collected from water standing on Pad A. Also commencing in 1974, samples were
collected from the Pad A drainage ditch (see Figure 5) and analyzed by gamma spectroscopy.
This sampling-4l1d. analytical program continued through 1975. From 1976 through 1981,
surface water samples were collected annually from the Pad A culvert and were analyzed for
gross alpha and gross beta in addition to gamma spectroscopy. Sampling of th~. Pad A
culvert continued until 1986. Because monitoring of surface water at Pad A was conducted
after periods of rainfall or snowmelt, there was no set frequency for surface water sample
collection. Overall the Pad A surface water samples were consistent with or were within the
range of the control values taken, and the data do not confirm or refute the leaching of
nitrates or radionuclides from Pad A waste.
411.
-------
Table 2. Pad A specific nuclide radioactivity by year in curies from RWMIS.
Half-Life
Radionuclide (yr) 1972 1973 1974 1975 1976 1977 1978 Total
\
~
K-40a I .277E+09 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5 .200E-0 I
TH-232 I .405E+ I 0 0.00 0.00 2.779E-05 1.090E-07 0.00 0.00 0.00 2.790E-05
U-234 2.450E+05 0.00 0.00 I. I 23E-05 0.00 0.00 0.00 0.00 I . I 23E-05
U-234'b 2.450E+05 7.281 E-OI 1.342E+00 1.393E+00 1.439E+00 4.853E-OI 9.160E-01 7.775E-01 7.080E+00
U-235 7.038E+08 3.3 17E-02 6.114E-02 6.345E-02 6.554E-02 2.21 lE-02 4.173E-02 3.542E-02 3.226E-OI
U-238 4.468E+09 2.672E+00 4.680E+00 4.873E+00 5.206E+00 1.638E+00 3.11 IE+OO 2.768E+00 2.495E+01
PU-238 8.774E+OI 2.572E-04 I .462E-03 1.9 JOE-02 1.379E-03 6. J09E-03 1.483E-04 2.017E-04 2.866E-02
PU-239 2.4 I 2E+04 7.30JE-03 8.756E-02 5.423E-01 3.933E-02 1.735E-01 4.585E-03 6.562E-03 8.61IE-OI
PU-240 6.570E+03 1.656E-03 6.916E-02 1.230E-0 I 8.938E-03 3.934E-02 1.089E-03 I .603E-03 2.448E-01
PU-241 1.435E+OI 4.389E-02 2.495E-OI 3.259E+00 2.392E-0 I 1.043E+00 2.895E-02 5.281 E-02 4.9 I 6E+00
PU-242 3.763E+05 I .1 82E-07 6.720E-07 8.779E-06 6.358E-07 2.808E-06 6.232E-08 1.0188-07 1.3 I 8E-05
a. The K-40 radioactivity is based on the mass of natural potassium in Pad A.
b. U-234' is U-234 that is calculated from the presence of U-235. It is not automatically listed in the RWMIS database.
-------
~
..
,
\
\
I-"
W
..::;:::"
...::s-
..:;S::"
.S'
..SS"
.;-
.S'
...ss-
...:::,...
LLWPII
.
SDA
200 Meiers
. Surface water sampling locaUons
Figure 5. TSAISDA surface water sampling locations.
-------
Radionuclides
Between 1974 and June 2, 1982,46 surface water samples were collected from the
Pad A drainage ditch (Figure 5) and were analyzed by gamma spectroscopy. Cs-137 was
detected in 19 of the 46 samples; the mean concentration of Cs-137 in these 19 samples was
1.1 x 10-8 J,lCilmL. . . .
Commencing in 1976, the surface water samples were also analyzed for gross alpha
and gross beta. Between 1976 and June 1982, 39 water samples were analyzed for gross
alpha and gross beta. Gross alpha activity was observed in 4 of the 39 water samples;
however, none of the concentrations exceeded the DOE Radiation Concentration Guide (RCG)
for gross alpha activity in surface water (3 x 10-8 J,lCilmL). The RCG was the allowable
activity of a radionuclide in a specific media in an area where public access is allowed.
Gross beta activity was detected in 34 of 39 samples, but again, none of the samples
exceeded the RCG for gross beta activity in place at that time (Le., 3 x 10-7 J,lCilmL).
Analytical results for surface water samples taken from the Pad A culvert in 1980 and
1982 are provided in Table 3. Table 4 presents the analytical results at Pad A from 1983 to
1985. Surface water samples for radionuclides at Pad A were not taken in 1981:
Nonradiolo2ical Contaminants
Analysis of surface water from the Pad A culvert for nitrates commenced in 1980 and
concluded in 1986. The analytical results for these surface water samples are summarized in
Table 5. The nitrate concentrations ranged from 0.08 ppril to 28 ppm.
5.1.2 Soil
Radiological sampling of Pad A soils began in 1984. Analysis included gamma
spectroscopy and radiochemistry for Pu-238, -239, U-235, -238, Am-241, and Sr-90. Nitrate
sampling commenced in 1979 and concluded in 1984. Samples were normally taken in the
spring and fall. Nitrate concentrations collected from Pad A were cons~stent with nitrate
concentrations of control samples outside of the RWMC.'
Radionuclides
Routine sampling of the Pad A soil cover for radionuclides began in 1984. Sample
locations are presented in Figure 6. . Each sample location was 10 x 1O-m2, and samples were
collected from each corner of the square and from the center. The composite samples ranged
from a depth-of 0 to 2 in. The samples were then combined to form one composite sample to
represent the entire sample location. Analysis of the samples included gamma spectroscopy
and radio chemistry for Pu-238, -239, -240 and U-235, -238, Am-241 and Sr-90. Analytical
results of specific radionuclide analyses taken in 1984, 1986, and 1988 are presented in
Table 6.
-------
.
"
Table 3. Surface water results at the Pad A from 1980 and 1982.
~'
AI
Measured concenlralion
(108 IICi/mL)
Year
Localion
(if known)
Samples
. collecled
(if known)
Type
1980
Gross Bela
1982
TOA (Pad A)
Ditch
Big losl River
(conlrol)b.
Pad A dilch
6
3 10lal samples
2 positive
5
Gross Alpha
Gross Del a
Pad A dilch
6
Gamma-
Cs-137
Pad A dilch
6 samples collecled
2 posilive
6 samples collecled
I positive
6 samples collecled
I positive
6 samples collecled
I posilive
Gamma-
Nb-95
Pad A dilch
Gamma-
Ru-106
Pad A dilch
Gamma-
Ag-11O
Pad A ditch.
a. No dala recorded.
Minimum
(if known)
Mean
(if known)
Maximum
(if known)
2.2 :t 0.5
NOR'
3.8 :t 1.1
NOR
NOR
DOL-GnIVllo<
See maximum
NOR
DOL-GA 1911 ~
NOR
A verage value was
3 limes Ihe conlrol
samples'
NOR
NOR
NOR
0.75 :t 0.29
NOR
NOR
0.11 :t 0.111
NOR
NOR
3.2 :t 1.1
NDR
NOR
0.67 :t 0.23
b. Before 1983, conlrol samples were collecled from Ihe B~g Losl River, approximalely 20 mi norlhwesl of the RWMC.
c. BDl-GBI91O = Delow 1980 Gross Deta Deleclion limit 3.0 x JO.8 JlCi/ml.
d. BDl-GAI98Z = Below 1982 Alpha Oeleclion limit 3.0 x 10"9 JlCi/ml.
-------
Table 4. Surface water results at Pad A from 1983 to 1985.
Unfillered'b.< Parliculatc,.b
aClivily aClivily
Date of collection Sampling location Radionuclide (10.1 J!Ci/mL) (lO.M IICilmL)
07/06/83 Pad Ad Cs-137 96.04 :I: 1.48 22.26 :I: 0.53
Controle No water available No waler available No waler available
07/11/83 Pad A Cs-137 0.62 :I: 0.08 NORf
11/17/83 Pad A Only NOR1 NDR NOR
Conlrol Only NOR NDR NDR
3/14/84 Pad A Only NOR NDR NDR
06/19/84 Pad A Cs-137 0.37 :I: 0.085 NOI analyzed
07/25/84 Pad A Only NOR NDR NOR
10/25/84 Pad A Am-241 0.014 :I: 0.0005 Not analyzed
Conlrol Pu-239, -240 0.009 :I: 0.004 NOI analyzed
Am-241 0.06 :I: 0.02 Not analyzed
TOlal U 0.01 :1:0.01 Nol analyzcd
04/01/85 Pad A Only NOR NDR NOR
Conlrol Only NOR NOR NOR
05/15/85 Pad A TOlal U Not detecled 0.08:1: 0.01
Conlrol Only NOR NDR NOR
07/17/85 Pad A Only NOR NOR NDR
Control Cs-137 1.7 :I: 0.2 2.4 :t 0.2
a. Replicale samples were collecled from many local Ions; therefore, multiple concenlrations for a single radionuclide 01 a single location may be nOled.
b. Results include an analytical uncerlainly of:t 1 slandard devialion.
. . I
c. Because Ihe waler samples re-acidified before fillralion, radionuclides originally ion-exchanged or physically sorbed onto suspended solids may have been solubilized
to some degree. Thus, Ihe radionuclide concenlralion in Ihe liquid may be higher Ihan thai which exiSIS in Ihe environment. Likcwise, Ihe radionuclide conccnlralion in
the particulale portion may be lower Ihan in Ihe ,environmcnl. .
d. Values oblained for Ihese samples were Ihe results of a spill wilhin Ihe RWMC and are not represenlative of normal condilions. TIle higher Ihan normal values
obtained for cesium and slrontium on these dates resulled from spread of conlaminalion within the SDA by leakage from a nonstandard waste box. Thc box was
lemporarily slored on Pad A. Conlaminants were washed from Ihe bcd of Ihe transport trailer 0010 Pad A and carricd inlO and down Ihe drainage dilch local cd on the
soulh side of Ihe main SDA road. Al'ler cleanup efforls Ihe Pad A ditch sample showed reduced levels of conlamination (see July II Pad A sample results).
e. Beginning in 1983 conlrol samples were collected al a location approximately 3 mi northeasl of Ihe RWMC where surface waler ilccul1lulaleS after prccipilillion.
f. No data recorded.
-------
Table 5. Nitrate concentrations in Pad A runoff water (1980 to 1986).3
~
Location
yeaz
Concentration
(oom)
Pad A Dirch
Conaol
1980
2.S-A ve. of 4 samples
0.86-Taken from the
Big Lost River
..
Pad A Ditch
Conuel
1981 - April"
- April"
Conaol
- September
0.5 (average of 3)
1.2- Talcen from the
Big Lost River
0.6- Talcen from the
Big Lost River
P:1d A Dirch
Conuel
1982 - March
- Mach
Pad A Dirch
Conuel
- September
- September
0.08
O.07-Taken from the
Big Lost River
4.7
1.8-Taken from the
Big Lost River
P:1d A Ditch
Control
P:1d A Ditch
Control
P:1d A Ditch
Control
P:1d A Ditch
Control
Pad A Ditch
Control
1983 - March
- March
- May
- May
- June
-June
- July
- July.
- December
- December
2.1
1.4.
28
2SC
3.0
33.5"
5.5
No water available
2.0
4.SC
P:1d A Dirch
Control
P:1d A Ditch
Conuel
P:1d A Ditch
Control
Pad A Ditch
Control
1984 - March
- March
- May
- May
- July
- July
- December
- December
3
J<
Id
69"
O.~
J<
4
IJ<
P:1d A Ditch
Control'
1986 (maximum results)"
2.2 ~ 0.1
2.7 : 0.2
a.. No 1985 water sample nitr:ue results was published (annual rcpon).
b. Reponed in the 1981 annual repon as single April values; however. these results appc:ll' to be the averages of three samples. The
actUal sample d:ltes were nor reponed.
c. Conuel samples (i.e.. back!m)und) collected approximately 3 mi nonhcast of the RWMC.
d. Below the detection limit
..
e. The only value pu~~~e~ in the 1986 annual rcpon was the maximum result.
f. Control t:IIcen from a collection system on top of P:1d A.
..,
-------
PAD A
\\ 2tr
2-1
.
.
.
.
.
.
.
.
.
.
Transuranic
Storage Area (TSA)
. .
.'
Location
2-1
2-2
2-3
2-4
2-5
General Reference
South End of Pad A Culvert
West Side of Pad A
Southeast. mid-slope
Northeast. bottom of slope
North. bottom of slope
Coordinates
N.669.417.15 E.266.945.91
N.669.730.66 E.266.905.16
N.669.637.25 E.267,075.43
N.669.756.97 E.267.128.78
N.669.832.36 E.267.005.50
Area 1 CJ Active Areas -
Area 2 D PadA
Area 3 ITIill Inactive Areas
Area 4 S Previously Rooded Areas
Area 5 D Transuranic Storage Area (TSA)
Figure 6. Pad A sampling locations and designated RWMC areas for soil.
-------
~
5'
~.
..
'I able 6. Activity concentrations in Pad A soils (1984 to 1988).
Pu-238 Pu-239,240 Am-241 U-234 U-235,238 Co-60 Cs-131 Sr-90
I.ocal ion activity aClivity activily activily activity activily activity aClivity
Year (if known) 1 0'6(~Ci/g) 106(~Ci/g) 106(IICi/g) 106(IICi/g) 1O-6(~Ci/g) 10 61~Ci/g) lO'IIICi/g) 10 '1IICi/g)
1984 2-1-2-5 NR' <.2" <.6" NR NR Neg. data <.6" <.8"
Conlrol NR <.1 =.6' NR NR ".3 .9 ".11
\
1986 2-1 ' NR .42 :t .06 .71 :t .04 .6:t ,I NR NR .39:t .11 NR
Unknown NR .36 :t .03 .5:t .1 .S:t .1 NR NR NR NR
2.4Sd NR -' .IS :t .01 .6 :t .I NR NR NR NR
2-5 NR -' .14 :t .01 .5 :t .I NR NR .9 :t .02 NR
2-4 NR .I3:t .02 .36 :t .03 NR NR NR Nit NR
Control NR .09 :t .02 .44 :t .05 .6:t .1 NR NR NR NR
Control NR .08 :t .02 .39 :t .04 .6:t .1 NR NR NR NR
Control NR -' -' .4 :t .1 NR NR NR NR
Control NR -' -' -' NR NR NR NR
1988 2-1 -' .62 :t .006 .97 :t .09 NR NR NR NR .24 :t .05
2-IS .018:t .006 .9 :t.1 .1 :t .09 NR NR NR Nit -'
2-2 -' .016:t .006 .14:t .02 NR NR Nit Nit .
2-2 -' .011 :t .004 .03 :t .006 NR NR Nit NIt -'
2-2 -' .022 :t .005 .03 :t .006 NR NR NR Nit -'
2-3 -' .31 :t .03 .63 :t .06 NR NR NR Nit -'
2.3 -' .29 :t .03 .68 :t .07 NR NR Nit Nit -'
1988 2.4 -' .022 :t .005 .I :t.01 NR NR NR NR -'
2-4 -' .018:t .004 . .08 :t .01 NR NR Nit NR -'
Conlrol -' -' .01 :t .006 NR NR NR NR .54 :t .07
Conlrol -' .039 :t.OO6 .OS i .01 NR NR NR NR .49 :t .08
-------
Table 6. (continued).
l'u-238 Pu-239.240 Am-24 I U-234 U-23S,238 Co.60 Cs.137 5r-90
location aClivily activily aClivity activity activily activity activily aClivity
Year (if known) 106(j!Cilg) 106(IICilg) ao-6(j!Cilg) ao-6(IICilg) 106(IICilg) 106(JICilg) 106(IICilg) I06(IICilg)
1988 Pad A-no Gamma spec. Gamma spec. Gamma spec. Gamma spec. Gamma spec. Nn .246 :t .026 Gamma spcc.
specific
locmion \
idcnlified :
Control Gamma spec. Gamma spec. Gamma spec. Gamma spec. Gamma spec. NR .1 SO:t .06 Gamma spec.
Control Gamma spec. Gamma spec. Gamma spec. Gamma spec. Gamma spec. NR .191 :t .06 Gamma spec.
Control Gamma spec. Gamma spec. Gamma spec. Gamma spec. Gamma spec. NR .131 :t .006 Gamma spec.
a. Not reported. No values were given in annual surveillance reports or no evalualion was made (or the radionuclide.
b. This value is the mean of samples collecled from all Pad A local ions. The reported value was taken from Ihe 1984 annual RWMC surveillance report. The informalioll was published ill
bar graph (orm. The values reported in this luble are interpreted (rom the bar graphs.
c. ..6 indicales that the value was inlerpreled as approximately 6.
d. 5 indicates a sample splil.
-------
NonradioIoeicaI Contaminants
"
Nitrate monitoring of the Pad A soil cover commenced in 1979 with the collection of
five samples. . Routine nitrate sampling of the Pad A soil cover commenced in 1980 and
concluded in 1984. This program consisted of collecting five samples twice a year, normally
the spring and fall. The sampling and control locations are shown in Figure 7 and results are
presented in Table 7.
"
5.1.3 Groundwater
Monitoring for nitrates in groundwater has been periodically conducted at the INEL for
many years. Some concentrations were observed in 1952 to 1970 to be as high as 20 mgIL in
'the northeast comer of the INEL south of Terreton, Idaho. The Maximum Contaminant L,evel
(MCL) for nitrate is 45 mgIL. Possible recorded sources of the high nitrate concentrations
were chemical and organic fenilizers and sewage disposal.
In 1988, nitrate concentrations in water from United States Geological Survey (USGS)
Wells 88 (approximately 500 m south of the RWMC) and 89 (approximately 500 m west of
the RWMC) were 7.5 and 8.0 mgIL, respectively (Figure 8). These are very similar to
concentrations found at other facilities at the INEL [e.g., Test Reactor Area (TRA), Naval
Reactor Facility (NRF)]. At TRA, concentrations ranged from 5.3 to 6.6 mgIL. Nitrates at
NRF contained 8.0 'mgIL.
Data obtained in 1992 from RWMC monitoring wells MIS, M3S, M6S, M7S, MIaS,
and M4D (Figure 8) were evaluated. The 1992 nitrate concentrations in groundwater
collected from RWMC perimeter wells ranged from a low of 2.1 mgIL in Well M7S to a high
of 6.0 mgIL in Well MIaS.
5.1.4 Biotic
. . . ... .. '. ".. " . .'
Transport from radioactive waste to biota at the SDA has been quantified through
collection and analysis of vegetation, small mammals, and soil samples from excavation of
mammal burrows. The routine biotic sampling program at the RWMC began in'1984 with
the collection of vegetation and excavated soils. The routine sampling for radioactivity in
small mammals began in 1985, when deer mice were collected for analyses.
~
Results of sampling and analysis for radioactivity in small mammals were obtained from.
various locatio,ns within the RWMC beginning in 1985. Several species including deer mice
and ground squirrels were collected during the reporting periods; however, these species were
collected over the RWMC as a whole and were composited. Therefore no data specifically
pertaining to PaCl A are available.
.
Ve2etation
In 1984, samples of crested wheatgrass and Russian thistle were taken from Pad A.
Cs-137 was detected in the Russian thistle sample at a concentration of 0.20 ~Ci/g which was
equal to control sample concentrations. In 1985, 1986, 1988, and 1989, no gamma-emitting
-------
* Soil nitra!e san"4)ling location
o Water nitrate sampling locations
Pad A north (control) * T
EJevS016 II I
100 meters
USGS Well #87 ....I....
Frt16
SDA
USGS Well t88 .
I.
* Pad A south (control)
I EJev SOZ2 ft
.,
100 meters
Figure 7. Pad A soil and water nitrate sampling locations.
22
\
'\
TSA
200 Meters
-------
Table 7. Nitrate concentrations in Pad A soils (1979 to 1984).
Results in Parts per million'
.,.
Location Year Soring Average Fall
-., Pad A Ditch 1979-1980 (4 samples) NAa 23 NA
Soil Berm 1979-1980 (5 samples) NA 7 NA
Spreading Areas 1979-1980 (2 samples) NA 58 NA
Background Areas 1979-1980 (4 samples) NA 6 NA
Pad A Ditch 1981 25.0 NA 30.0
East-l 12.6 NA 12.0
East-2 14.4 -NA 11.0
North Control 7.3 NA 23.0
South Control 11.7 NA 9.2
Pad A Ditch 1982 35 NA 49
East-l 2.3 NA 11.7
East-2 3.7 NA 3.8
North Control 6.0 NA 17.6
South Control 2.3 NA 6.4
Pad A Ditch 1983 24 NA 28
East-l 5.5 'NA 1
East-2 5.1 NA 1.4
North Control 14 NA 1.7
South Control 6.2 NA 1.6
Pad A Ditch 1984 1_~, ' NA 42
' , .
Berm (Ave. E-l&2) 73 NA 12
North Control 85 NA 4
South Control 35 NA 3
a. Not applicable. After 1981, both the spring and fall sample results were reported for each
year. Thus, NA (not applicable) notations are used to distinguish where no data were
available to complete the column. The average values for combined years are reported,
because, no additional data are available to distinguish sample results between lQ79 and 1980.
~
b. Approximate detection limit is 1 ppm.
..
-------
USGSoI7
.
ocvz:r-?
IaS
~ocvz~
puLM.J
fffl . AWIIC production
PU a
PI~;:;:;;:;;;:;;;:;,,;;;;;;;;,,:;;;;;;;~r.;.~ PI'
fE]Acldpit
.
USGS 117
USGS-II
.
IUO
\. OCVZ~
. Grcundll8:t8rmcnilal"ll-'
@I N8wVrcundlnl.._laf"ll-"
1II_8IIwlh wpcrparta
.. OCVZ..." pat 8IllcaICIn
Figure 8. Well locations.
\
IJSGS.eO
.
TSA
.
USGS "8
"
,
-
..;.
--
24
l
Hartl
-------
,.
radionuclides were detected in vegetation collected at Pad A. No data were available for
alpha or beta emitting analyses because of inconsistencies in Quality Assurance/Quality
Control samples and results. In 1987, Cs-134 and -137 were detected in one sample at
concentrations found in other RWMC samples of the same analysis.
5.2 Pad A Soil Overburden Sampling and Drum Retrieval Activities
~
1979 Inspection
The TSAJTransuranic Disposal Area (IDA) penetration project was initiated on
September 26, 1979, and completed on October 12, 1979, when the excayated area was
refilled with soil. The purpose of the penetration was to assess the condition of the oldest
waste containers and to obtain soil samples from, within the pad to detect migration or leakage
of waste. The TDA was later renamed Pad A. The penetration locations .are shown on
Figure 9. Area B, which contains wooden boxes, and Area A, where 55-gal drums are stored,
were selected for penetration and sample retrieval because they contained the oldest waste
containers stored on the pad. The entire north end of the pad was established as the work
area boundary.
Overburden removal began at the northeast comer of the pad to expose the oldest
containers. Excavation continued south along the east boundary until ten rows of drums were
uncovered and three rows of boxes were visible. The drums, lids, and lockrings showed
varying degrees of corrosion. but appeared to be basically intact. One drum. which was
breached during overburden removal. was resealed. The uncovered boxes appeared to be in
an advanced state of deterioration caused by moisture accumulation and/or damage caused by
excavation. The condition of the boxes and concern over safe handling of the drums
precluded retrieval of waste containers.
The condition of the waste containers examined during penetration activities appeared to
be questionable since the plywood boxes were in an advanced state of decomposition;
however, the inner lining of the boxesappearedto"be-in- good-condition~' "The drums' showed ,- ,
visible signs of. rusting, especially on the tops and lockrings. Many of the drums showed
damage such as dents and scratches, which probably occurred during disposal. Based on a
visual inspection, none of the waste containers or their inner linings were' breached to the
extent that waste had been lost from the drums.
1988 Inspection
i'.
The strategy for the Pad A initial penetration investigation in December 1988 was to
sample the Pad A cover soil, excavate to the waste, sample the interstitial soil between the
drums, and inspect the condition of Pad A drums.
~
The soil sampling was proposed to determine the type. concentration, and location of
metal and volatile organic contamination in the cover soils. The sampling was conducted
near two locations on Pad A shown on Figure 10. The halogenated VOC analyses indicate
that no VOCs were detected in the soils. The results of the analyses run on the eight
. inorganic samples collected during the cover soil sampling investigation are summarized in
Table 8. The metal and salt compound analyses in Table 8 indicate that uranium was not
-------
A
.............. =
320 ft
I
.
I
----
o
"
-------
PAOA188005
12
~
4
PAOA188008
...
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
"
.
,
,
.
.
"
~
.-
6
PAOA 188007
..
PAOA188006
.~
14
16
"
8
LEGEIID
6
...........
...
..........
.......-
North Penetration
Not drawn to scale
1S:9----
. -0....
"""'" ..................... ..........
PAOA188001
. .
2
PADA188002
18
8
10
. - "- ~ .
10
14
PAOA 188004
14 -
PAOA188003
6
~,
South Penetration
..
. Sample location
PADA188001 -
Sample ID number
All distances in feet
from center node
Figure 10. 1988 sampling locations for the Pad A initial penetration.
-------
Table 8. Cover soils sample analysis for inorganics.a
Matrixb ,.
Lab sample # Beryllium Uranium Sodium Potassium Nitrate as NO)
8808s041-00 1 Water 0.005 1. 000 5.000 5.000 0.500 .
8808s041-003 Soil 1.100 200.000 1000.000 2249.000 5.700
8808s041-005 Soil 1.000 200.000 1081.000 2634.000 5.000
8808s041-006 Soil 1.180 200.000 1351. 000 3347.000 5.300
8808s041-007 Soil 1.150 11. 1 00 1001.000 3122.000 5.500
8808s041-008 Water 0.964 200.000 50.500 50.000 1.900
8808s041-009 Soil 1.340 200.000 1520.000 3418.000 0.500
8808s041-0 1 0 Soil 1.060 200.000 1213.000 2544.000 45.700
8808s041-0 11 Soil 1.300 200.000 1709.000 3508.000 0.500
8808s041-0 12 Soil 1.250 200.000 1206.000 3118.000 0.500
a. Source: Phase I sample analysis report.
b. Concentration units for water = IlgJL; concentration units for soil = mg/kg.
detected in any samples; beryllium was detected in seven of the eight samples at low
concentrations of up to 1.34 mglkg; sodium was detected in all samples and ranged from
1000 to 1709 mg/kg; potassium was detected in all samples and ranged from 2249 to 3508
mglkg; and nitrate was detected in five of the seven samples with values that ranged from
0.50 to 45.7 mg/kg. The background concentrations for beryllium, sodium, potassium, and
nitrate are 1.5 mg/kg, 192 mglkg, 5,180 mg/kg, and 36.5 mglkg, respectively. Based on the
results and low concentrations, it was concluded that the disrurbance of P1d A overburden
soils would not present a safety hazard to personnel.
1>
Sampling and screening of the cover soils were conducted on November 1988 to
determine the lateral extent of volatile organic contamination as shown in Figure 10.
Nineteen samples were collected from designated points within the north and south
penetration locations. The results of the screening analyses run on the 19 samples collected
during the cover soil sample/screening investigation indicate that no VOCs were detected in
the soils.
.
-------
J'
Efforts to demonstrate drum retrieval of Pad A containers began in 9ctober 1989. On
December 7, 1989, eight drums were uncovered. All drums showed signs of corrosion; six
were corroded through and contained openings ranging from the size of a pin hole to gaps 3
to 4 in. long. Drum surfaces in contact with plywood were also badly corroded. Because
operational safety requirements prevented removal of breached drums, subsequent operations
centered around two visually intact drums. However, on December 21, 1989, in, situ
ultrasonic testing and visual examination revealed a small hole in one of the drums. No holes
were observed in the other drum which was subsequently removed from the penetration pit on
January 8, 1990.
.
Results of radiological analysis did not indicate that radioactive c~ntamination was
present on or near the drums. Continuous air monitor (CAM) filters did not show detectable
alpha contamination; beta-gamma airborne levels were less than airborne concentration limits.
The VOC concentrations, measured with an organic field detection instrument, ranged from 0
to 10 ppm near the exposed drums. The VOCs in the space between the drums generally
remained lower than 50 ppm but reached a high of 70 ppm.
6. SUMMARY OF SITE RISKS
The risk assessment for Pad A considered both human health and ecological risks.
The human health risk assessment evaluated both present and future potential exposures to
contaminants. The risk assessments were conducted in accordance with the EP A Risk
Assessment Guidance for Superfund, Volume I: Human Health Evaluation Manual and
Volume II: Environmental Assessment Manual and other EP A guidance. The risk assessment
methods and results are summarized in the following sections.
6.1 Human Health Risks
The risk assessment consisted of contaminant identification, exposure assessment,
toxicity assessment, and human health risk characterization. The contaminants identified at
'Pad A were based on existing inventory'records'and"process knowledge:"The 'exposure ..' - ,,-
assessment detailed the exposure pathways that exist at the site for workers, offsite residents,
and potential future onsite residents. The toxicity assessment documented the adverse effects
that may be caused in an individual as a result of exposure to a site contaminant.
~,
The human health risk assessment evaluated current and future potential carcinogenic
and noncarcinogenic risks associated with exposure to contaminants identified in the Pad A
waste inventory. The human health evaluation used both the exposure concentrations and the
toxicity data to determin~ a hazard index for potential noncarcinogenic effects and an excess
cancer risk level for potential carcinogenic contaminants. In general, when a hazard index
exceeds one, there.may be a concern for potential noncarcinogenic health effects. The excess
cancer risk level is the increase in the probability of contracting cancer. The National Oil and
Hazardous Substances Pollution Contingency Plan (NCP) acceptable risk range is 1 in 10,000
to 1 in 1,000,000. An excess lifetime cancer risk of I in 10,000 (10""') indicates that an
individual has up to a one chance in ten thousand of developing cancer over a lifetime of
exposure to a site-related contaminant. .
.
-------
Key steps taken in the risk assessment process are summarized in Sections 6.1.1
through 6.1.5.
6.1.1 Identification of Contaminants of Concern
..
Contaminants evaluated in the baseline risk assessment (BRA.) are the following
radionuclides and inorganic compounds identified in the waste inventory, based on an
evaluation of the R WMIS database:
.
Radionuclides
Inonzanic Compounds
Potassium
Thorium
Uranium
Plutonium
Americium
Sodium Nitrate
POtassium Nitrate
Sodium Chloride
Potassium Chloride
Sodium Sulfate
Potassium Sulfate
Sodium Hydroxide
POtassium Hydroxide
Triuranium Octaoxide
Total estimated chemical masses and radionuclide activities are given in Tables 1
and 2 respectively.
Environmental monitoring of ground water, surface water, air, and soil has not
demonstrated any contaminant releases attributable to Pad A wastes; therefore, fate and
transport modeling of Pad A wastes was used in the BRA. to evaluate potential risks. The
modeling estimates contaminant movement through soil, air, and water. These estimates
provide contaminant concentrations in a given medium at a specific time and allow
evaluations of potential future risks to human and ecological receptors.
6.1.2 Exposure Assessment
Exposed Populations
Only exposure pathways deemed to be complete (i.e., where a plausible route of
exposure can be demonstrated from the site to an individual) were quantitatively evaluated in
the risk assessment. The populations at risk due to exposure from Pad A wasr~s WeIC
identified by considering both current and future use scenarios.
.,.
The ooman health risk assessment evaluated carcinogenic and noncarcinogenic risks
for a period of 1,000 years after the waste was disposed (1972-2971). The 1,000-year period
was further divided into three current and future use scenarios:
.
1.
The current industrial scenario is expected to continue until the year 2015.
Under this scenario, potential exposures to workers at the RWMC and residents
adjacent to the INEL were evaluated.
-------
2.
Through the year 2090, it is assumed that DOE will continue to operate and
maintain the RWMC to prevent unrestricted public access to the facility. ° (DOE
Order 5820.2A, Radioactive Waste Management, requires conU'OI of radioactive
waste disposal sites for a minimum of 100 years following closure.)
Institutional controls would be implemented to control the facility and may
include, but are not limited to, restricting land use; conU'Olling public access;
and the posting of signs, fencing, or other barriers. Under this scenario,
potential exposures to workers at the RWMC and residents adjacent to the
INEL were evaluated.
.
j
3.
To determine the baseline risk in the absence of institutiQ.nal controls, it is
assumed that the INEL will be available for unrestricted use beyond the year
2090. The potential risks from residential development adjacent to the INEL,
RWMC, and Pad A boundaries were evaluated.
Contaminant transport from the source to receptors was modeled using three different
computer codes: (a) GWSCREEN, which models the transport of contaminants from the
source to the subsurface; (b) DOSTOMAN, which models the transport of contaminants from
the source to the surface; and (c) a simple "Box" model, which models transport of
contaminants through the air, once they are brought to the surface.
The GWSCREEN is a combination of three different models. The models address the
mass flux of contaminants released from the source, the transport of the contaminants through
the unsaturated zone, and transport of the contaminants through the aquifer. In the source,
the contaminant is assumed to be uniformly mixed throughout a parallelopiped source region
and the mass flux from the source is assumed to be a fIrst-order leach function.
For contaminant transport in the unsaturated zone, GWSCREEN employs a plug-flow
model which incorporates retardation due to adsorption and decay of radionuclides but
neglects dispersion. In this portion of GWSCREEN, the unsaturated zone is assumed to be
homogeneous and the inflltrationorate°througlr.theo'unsaturated- zone is modeled-as a'steady~ 0'"
state one-dimensional flow.
The GWSCREEN uses a semianalytical solution to the advectioIi-dispersion equation
to model contaminant transport in the aquifer.
~
The DOSTOMAN code was used to model mechanical transport of contaminated soil
through the uptake of waste through flora and burrowing mammals. The DOSTOMAN code
mathematically simulates movement of contaminants from a subsurface "source" compartment
to overlying "sink" compartments by means of solving a system of differential equations at
specifIc time .steps.
..
The movement of contaminants through air from Pad A to a distant receptor was
modeled using a simple "Box" model solution. This method calculates the volume of air
passing over Pad A that is swept out per second in order to determine a volumetric rate of
° contaminants from Pad A. °
-------
Several assumptions were used to model contaminant fate and transport. These
assumptions, along with the associated uncertainties, are discussed in Section 6.1.5.
The fate and transport modeling indicated that radionuclides (with the exception of
potassium-40) would not reach the aquifer within 1,000 years. The modeling showed
potassium-40 reaching the aquifer within the 1,000 year timeframe, but it was not shown to
pose an unacceptable risk.
.
.
The evaluation of current and future use scenarios assumes that industrial workers and
residents would be located at the locations shown in Table 9. For the residential scenarios, it
was assumed that a family would occupy the area and engage in agricultural activities such as
irrigation of crops, livestock watering, and domestic activities that would utilize water
pumped from the Snake River Plain Aquifer (SRP A).
Exposure Pathways
The following exposure pathways were evaluated in the risk assessment for both the
current and future risk scenarios:
.
Ingestion of surface soil
.
Inhalation of contaminated dust
.
Ingestion of drinking water (groundwater) from the SRP A
.
Ingestion of food crops (residential scenario only)
.
External exposure to radionuclides.
The exposure parameters (such as exposure frequency and duration), used in the risk
assessment were obtained from Standard- Default Exposure Factors guidance (EP A Risk' .
Assessment Guidance for Superfund, Volume I: Human Health Evaluation Manual,
Supplemental Guidance. "Standard Default Exposure Factors, OSWER Directive 9285.6-03,
1991). The exposure parameters used are shown in Table 10.
Exposure Point Concentrations
Contaminant concentrations at points where the potential for human exposure is
expected to occur are necessary to evaluate the intake of potentially exposed individuals.
Exposure pathways from the source to individuals were evaluated using a groundwater
transport computer model, GWSCREEN; a mechanical mixing model, DOSTOMAN; and an
air transport model. The results of the computer modeling indicated nitrate concentrations in
groundwater are estimated to peak approximately 250 years in the future at the predicted
concentrations shown in Table 9. These concentrations, used in conjunction with future
receptors being located at Pad A and RWMC boundaries, constitute a reasonable maximum
exposure scenario at Pad A. Exposure point concentrations for the media associated with
other pathways (e.g., ingestion of surface soil) are provided in Section 5 of the Pad A RlIFS
Report.
.
~
-------
Table 9. Summary 'of risks from Pad A. (Estimated risks are for releases. from Pad A only.
.Cumulative risks for all sources at the RWMC will be evaluated in the RWMC
Comprehensive RI/FS).
..
, ~ceDario Carcinogenic Ris~ Nitrates as Noncarcinogenic Riskb
Nitrogen in (Hazard Index)"
Groundwater ..
(mgIL)d
Current Scenario (throueh 2015)
Pad A Boundary (industrial worker) 8 in 100.000.000 0 Less than 0.0001
(8 x I~) (ingestion of soil)
RWMC Boundary (industrial worker) 4 in 1.000.000.000.000 0 Less than 0.0001
(4 x 10,12) (ingestion of soil)
INEL Boundary (resident) 2 in 10.000.000.000.000 0 Less than 0.0001
(2 x 10,13) (ingestion of food crops by
child}
INEL Control Period (throueh vear 2090)
Pad A Boundary (industrial worker) 4 in 10.000.000 0 Less than 0.0001
(4 x 10") (ingestion of soil)
RWMC Boundary (industrial worker) 4 in 10.000.000.000 0 Less than 0.0001
- (4 x H)'I~ (ingestion of soil)
INEL Boundary (resident) 2 in 100.000.000.000 0 Less than 0.0001
(2 x 10.11) (ingestion of food crops by
child)
Post-Control Period (2090-2971).
Pad A Boundary (resident) 2 in 100.000 112( 6
(2 x 10") (ingestion of water by infant)
RWMC Boundary (resident) 2 in 1,000.000 IT 1
(2 x 10" (ingestion of water by infant)
INEL Boundary (resident) 4 in 10.000,000 3 0.2
(4 x H)") (ingestion of water by infant)
,1
a. The National Contingency Plan (NCP) defmes an acceptable level of carcinogenic risk as less than 1 additional
incidence of cancer in 10,000 to 1,000,000 individuals_(Io-' to .la;... .
b. A hazard index (the ratio of the level of exposure to an acceptable level) greater than I indicates that there may be
concern for noncarcinogenic effectS.
c. Unless otherwise specified. hazard index refers to total noncarcinogenic risks for all exposure pathways for an adult
receptor. The text in parentheses indicates the primary contributing pathway.
d. The Federal drinking water standard for total nitrates (as nitrogen) in groundwater is 10 mg/L.
e. The concentrotions and associateCl risks for this period correspond to the year 2246. at which time maximum nitrote
concentrations occur in the groundwater.
~
f. The estim:lted ~~~e!1trotions were based on conservative groundwater modeling; actual concentrotions are expected to
be lower than the drinking water standard for nitrotes.
4
-------
Table 10. Exposure parameters used in the exposure assessment of contaminants at Pad A.
Exposure Exposure Body
Exposure Exposure frequency duration weight .,
pathway scenano Intake ratea (days/yr) (yr) (kg)
Ingestion of Industrial 50 mgld 250 25 70 "-
soil Residential 200 mgJd (child, 0-6) 350 6 15
100 mgJd (adult) 350 24 70
Inhalation of Industrial 20 mJ/d 250 25 70
contaminated
dust Residential 20 m3/d 350 30 70
Ingestion of Industrial 1 LId 250 25 70
water Residential 1.0 LId (infant, 0-3)b 350 3 12
0.83 LId (child, 3-6)b 350 3 17
2 LId (adult) 350 24 70
Ingestion of Industrial NA NA NA NA
food crops Residential 4.18 gld (child, 0- 350 6 15
6)b.c.d 350 24 70
8.62 gJd (adult)b.c
External Industrial NA 250 25 NA
exposure to
radionuclides Residential NA 350 30 NA
NA means that the parameter is not applicable to the exposure pathway or scenario.
a. EP A, 1991, Risk Assessment Guidance for Superfund, unless otherwise noted.
b. EPA, 1990, Statement of Work RIffS Risk Assessment Deliverables.
c. Includes ingestion of fruits, vegetables, and root crops.
d. The child parameter for ingestion of food crops was adjusted from EP A (EP A, 1990,
Statement of Work RIffS Risk Assessment Deliverables) to estimate an average intake for
children between ages 0 and 6.
.
Because of the overall conservative nature of the assumptions used in the fate and
transport modeling, the actual nitrate concentrations in groundwater are expected to be lower
than those predicted. In addition, the hazard indices calculated for infants and children are
based on two additional conservative assumptions: (a) peak sodium nitrate and potassium
..
-------
..
nitrate concentrations occur in groundwater at the same time, and (b) infants and children are
exposed to the sum of these peak concentrations. These latter two assumptions are
conservative in that the groundwater analysis actually predicted different travel times to. the
groundwater for sodium nitrate and potassium nitrate (Le., their predicted peak concentrations
are not additive). Given these conservative elements, the hazard index associated with the
groundwater ingestion exposure pathway is expected to be lower than 1.
~
6.1.3 Toxicity Assessment
The toxicity assessment addresses the potential for a contaminant to cause adverse
effects in exposed populations and estimates the relationship between extent of exposure and
extent of toxic injury (i.e., dose response relationship). -.
Two types of toxicity values were used in the risk assessment: reference doses, which
are used to evaluate noncarcinogenic effects; and slope factors, which are used to evaluate
carcinogenic effects. The Integrated Risk Information System database, an EP A online
computer database, and the EP A Health Effects Assessment Summary Tables provided
toxicity values for chemicals and slope factors for radionuclides for the contaminants at
Pad A. Some of the toxicity values were derived based on available toxicity information.
The reference doses used in the evaluation of noncarcinogenic effects are shown. in
Table 11. The inhalation pathway was not included in the risk calculanons for
noncarcinogenic effects because the inhalation reference doses were not available for the
chemicals identified in the waste inventory of Pad A. . .
Slope factors used to evaluate carcinogenic effects for the radionuclides were obtained
from an advance copy of the 1992 edition of the EPA Health Effects Assessment Summary
Tables: Annual Update, FY 1992, ORR Publication 9200.6-303 (92-1) and are shown in
Table 12. Pathway-specific slope factors were identified for ingestion, inhalation, and
external exposure.
1\.
The primary contaminants of concern,. baSed on-.theriskassessment; are the nitrate. . .
wastes. The primary concern with nitrate in the environment is related to its conversion by
biological systems to nitrite. Nitrite acts in the blood to oxidize hemoglobin to methoglobin,
which cannot transfer oxygen to the tissues. This condition is known as methemoglobinemia
and is caused by high levels of nitrite or, indirectly, excessive levels of nitrate in humans.
Nitrate toxicity can result from ingestion of water and vegetables high in nitrates (EPA
1992a). Infants are more susceptible to nitrate toxicity than adults. This increased
susceptibility is attributed to high intake per unit weight, the presence of nitrate-reducing
bacteria in the upper gastrointestinal tract, the condition of the .mucosa, and the greater ease
of oxidation of fetal hemoglobin. Infants (0-3) and small children (3-6) were evaluated as
separate populAti.O{l subgroups when calculating risks from ingestion of nitrates. Other effects
associated with ingestion of nitrates can include hypotension, tachycardia, respiratory
depression, headache, nausea, vomiting, and diarrhea.
.
-------
Table 11. Reference doses used to evaluate noncarcinogenic effects of contaminants at Pad A.
Ingestion RID
Contaminant (mglkglday)
Nitrates (as nitrogen) 1.60E+DO'
NaCI 8.60E+Dl b
KCI 9.50E+Dl b
Sulfates (NazS04 and ~S04) NA
NaOH NA
KOH NA
UPs 9 .OOE-O 1 c
,
Il
NA not available (An established RID is not available and no suitable toxicity infonnation was available to
derive a RID).
a. The RID for nitrates is based on nitrate-nitrogen; RID obtained from IRIS (EPA, 1992. Integrated Risk
Assessment Information System).
b. Provisional RID estimated from recommended limit for daily intake; see text for explanation (Private
communication with K. A. Poirier, Environmental Criteria and Assessment Office to C. Sweeney, EPA
Region 10, January 24, 1992).
c. Provisional RID estimated from a lowest-observed-adverse-effect-level (LOAEL) for dogs (Private
communication with K. A. Poirier, Environmental Criteria and Assessment Office to C. Sweeney, EPA
Region 10. January 24, 1992).
6.1.4 Risk Characterization
Risk characterization is the process of combining the results of the exposUre and
toxicity assessments. This process provides numerical quantification relative to the existence
and magnitude of potential public health concerns related to the potential release of
contaminants from the site.
Risk calculations are divided into carcinogenic and noncarcinogenic categories. The
calculation of health risks from potential exposure to carcinogenic compounds involves the
multiplication of cancer slope factors for each carcinogen and the estimated intake values for
that contaminant-
"
Noncarcinogenic risk is assessed by comparison of the estimated daily intake of a
contaminant to its applicable reference dose. A reference dose is a provisional estimate of the
daily exposure to the human population that is likely to be without an appreciable risk of
deleterious effects during a portion of the lifetime. The estimated daily intake of each
contaminant by an individual route of exposure is divided by its reference dose and the
resulting quotients are added to provide a hazard index.
..
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Table 12. Slope factors (SFs)a used to evaluate carcinogenic effects of radionuclides at
Pad A.
Inhalation External
. Ingestion SF SF exposure SF
Radionuclide (pCi)" (pCi),t [yr/(pCilg)]"1
...
j K-40 1.1£-11 7.6£-12 5.4£-07
Th-232 1.2E-ll 2.8E-08 2.6£-11
U-234 1.6E-ll 2.6E-08 3.0E-11
U-235 1.6E-ll 2.5E-08 -. 2.4E-07
U-238b 2.8E-ll .5.2£-08 3.6£-08
Pu-238 2.2E-I0 3.9E-08 . 2.8E-ll
Pu-239 2.3£-10 3.8£-08 1. 7E-11
Pu-240 2.3E-I0 3.8E-08 2.7£-11
Pu-241 3.6E-12 2.3E-I0 O.OE+OO
Pu-242 2.2£-10 3.6E-08 2.3E-l1
Am-241 2.4E-1O 3.2£-08 4.9E-09
a, All SFs were obtained from EPA, 1992, Health Effects Assessment Summary Tables
(BEAST): Annual Update, FY 1992.
b. The SFs for U-238 take into account the toxicity of its decay chain products (Th-234
and Pa-234).
Based on the results of the risk assessment, no current risk exists to workers or the
public from Pad A. The only potential risk identified by the risk characte.rization of Pad A
occurs at the Pad A boundary for residents during a 30-year period beginning in 2228,
primarily due to ingestion of nitrate-contaminated groundwater. Noncarcinogenic and
carcinogenic risks are summarized in Table 9.
'"
Although not quantitatively evaluated in the risk assessment, prolonged exposure to
Pad A contaminants through intrusion into the waste pile would likely pose an unacceptable
risk to human health.
6.1.5 Uncertainty
...
Risk assessments are subject to uncertainty from inventory records, fate and transport
estimation, exposure estimation, and toxicological data. Uncertainty was addressed by using
health-protective assumptions that systematically overstate the magnitude of health risks. This
-------
process is intended to bound the plausible upper limits of risk and to facilitate an informed
risk management decision. Table 13 is a summary of risk assessment assumptions and
associated uncertainties.
.
6.2 Ecological Concerns
The ecological risk assessment qualitatively evaluated the potential ecological effects
associated with the presence of Pad A. This ecological evaluation followed the EP A Risk
Assessment Guidance for Superfund Volume II. The'evaluation focused on the same
contaminants and receptor locations as those evaluated in the human health assessment.
Objectives of the ecological risk assessment are to qualitatively evaluate the potential risk to
ecological receptors from the contaminants in Pad A. The assessment identified sensitive
nonhuman species and characterized potential exposure pathways including ingestion of
contaminated soil and vegetation by small mammals and contaminant uptake by plants.
I{
The approach used in the ecological risk assessment is consistent with EP A guidance
for evaluating risk. The steps included identification of contaminants, assessment of potential
exposure pathways, and characterization of threats to exposed biota.
6.2.1 Exposure Assessment
The exposure scenarios assumed that the ecological species would be located at the
same receptor locations identified in the human health evaluation, the Pad A boundary, the
RWMC boundary, and the INEL boundary. The exposure pathways evaluated included
intrusion of the waste after institutional control by plants (sagebrush) and small mammals
(e.g., ground squirrels). Exposure routes included ingestion of contaminated soil and
vegetation and prey by mammals and uptake of contaminants by plants.
6.2.2 Risk Characterization
The risk characterization involved evaluating the potential adverse effects on
populations of organisms at Pad A. Impacts on environmental populations were assessed
based on the exposure routes presented above. The evaluation covered peak concentrations
for post-institutional control exposure periods. The quantitative evaluation that determines a
toxic soil concentration compared to estimated concentration in the surface soil indicated that
the Pad A contaminants will not pose a threat to the small burrowing animals.
Tole~.1I1ce limits for plant species were evaluated and were not determined to be at
levels that could adversely affect the plant species. These results of the ecological risk
assessment indicate that Pad A wastes are not expected to have any significant disruptive
effects on animal or plant populations or the local ecosystem. This information will be
incorporated into a WAG-wide or INEL site-wide ecological risk assessment to determine the
potential cumulative impacts to the environment from all areas.
..
.
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Table 13. Pad A estimates of conservatism in the baseline risk assessment.
Estimate basis:
~
TYPE:
DEGREE:
Conservative OR Not conservative
..
LOW
MODERATE
HIGH
(by factors of integers)
(by factors of integers to one order of magni~q.e)
(by greater than one order of magnitUde)
~
Uocertaioty Estimate of Type & Degree Effect of Conservatism on BRA ResuJts
Use of inventory data to NOT CONSERVATIVE - LOW
identify and quantify pOtential
contaminants - although Pad A disposal records have - None
been verified against RFP records. -.
uncertainties concerning measurement
inaccuracies may exist in the information
transmiued by RFP.
- chemical data was not provided in the - None
original inventory data (retrieved drum
sampling results indicate some hazardous
chemical contaminants may be present)
Biotic transport model CONSERVATIVE - LOW TO MODERATE
(DOSTOMAN)
- nitrate inventory was not depleted - Results in higher estimated
mathematically due to leaching (to concentrations in soils/overburden
account for source depletion) until 99% and thus increased risk
of mass was removed
- deposition of contaminants was - Results in higher estimated
integrated over the maximum time concentrations in soils/overburden
allowed for each risk window and thus increased risk (probably
low bias)
- mammal densities were combined for - Results in higher estimated
two different habitats (Russian thistle and concentrations in soils/overburden
Crested wheatgrass) and thus increased risk (probably
low bias)
- - vegetation and mammal densities were - Increased densities for the future are
increased based on futUre addition of based on data for vegetation and
natUral flora m~ in undistUrbed sites (no
known bias) .
. .
- maximum animal burrowing depths were - Results in significantly higher
extrapolated beyond maximum !NEL estimated concentrations in
depths based on Hanford stUdies soils/overburden and thus increased
ris.1c (probably low bias)
...
- all biomass of decayed plants and - Results in higher estimated
contaminants exhumed by mammals concentrations in soils/overburden
from the waste zone were retained in the and thus increased risk (probably
upper 35 cm compartment of overburden low bias) because wind erosion.
leaching by water. and increased
overburden thickness are not
accounted for (moderate to high
bias)
~
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Uncertainty Estimate of Type & Degree Effect of Conservatism on BRA Results
Surface pathway model
- Particulate matter CONSERVATIVE - LOW
- assumed 82 ug/mJ for particulate - Results in higher estimated soil
resuspension (98% confidence level that concentrations for contaminants and
the value will not be exceeded); assumed higher estimated erosIOn rates
all particulate < 10 urn and smaller
CONSERVATIVE - LOW
- FalloUt calculations
- constant fallout factor integrated over
each risk wmdow - See above
NOT CONSERVATIVE - MODERATE to
- Erosion rates HIGH
- standing water samples were used (does
not take inlO account larger particles that - Results in lower estimated surface
would not be readily suspended in water. erosion rates
i.e.. clay-sized particles); all runoff from
Pad A is assumed to have collected in
the sample location (ditch) which may
not be a true indicator of runoff; no
settling or flocculation was assumed to
have occurred; no chemical weathering
was considered; a recent evaluation of
the overburden erosion was conducted by
the EPA that indicated estimated
sediment loss over the next 100 years
may range 18 - 36 inches (see derajls in
verbal discussion of Section 7.1.4. I)
NOT CONSERVATIVE - MODERATE
- Contaminant release - 2m was used for erosion box model (vs.
rate box model 20m) which results in lower soil removal
assumptions rates (conservative for receptor exposure. - Results in lower estimated surface
but not conservative for surface erosion erosion rates
calculauons)
40
.
.
.
-------
...
Uncertainty Estimate of Type & Degree Effect of Conservatism on BRA Results
Groundwater modeling
- GWSCREEN code CONSERVATIVE. MODERATE to HIGH
. assumes plug-flow (no dispersion) in the - GWSCREEN overestimates calculated
unsatUrated zone peak concentrations and overestimates
transport time- to aquifer
- overestimates transport time to aquifer
. infiltration rate assumed to be 5 em/yr. and overestimates peak concentrations
actUal is 0.8 to 1.1 cm/yr. and no credit
was given for runoff
. Dispersivity Values NOT CONSERVATIVE - LOW . underestimates calculated peak
concentrations
- dispersivity values were assumed to be 45
m and 20 m and are probably high
estimates at the edge of Pad A
- FractUred vs. NOT CONSERVATIVE - LOW to
homogeneous media MODERATE - underestimates calculated peak
concentrations and travel times
- using GWSCREEN for fractUred media
may underestimate travel times due to
greater potential for "short-circuiting" of
fluids in the unsatUrated zone. localized
satUrated zones. etc. Furthermore. poorly
understood phenomena in the unsatUrated
zone. such as Taylor "instabilities" may
further result in underestimation of travel
times.
- Use of estimated K.ts CONSERVATIVE to
NOT CONSERVATIVE
- K.ts in the source region (underlying soils) - Calculated peak concentrations are
are assumed to be equal to K.ts in basalts overestimated
at Hanford. The K.t of the soils is
probably higher.
- unsatUrated zone assumed homogeneous. - Transport time to aquifer is
i.e.. no credit for surficial soils (1.5 to underestimated
10 feet thick below asphalt) or interbeds;
K.ss in the source region are probably
higher.
.'
- K.ss in the. source and unsatUrated zones - Calculated peak concentrations are
are assumed to be equal to K.ts for underestimated
crushed basalt at Hanford. The ~ of the
unsaturated zone is probably lower.
Catastrophic failure of CONSERVATIVE. MODERATE "
-
containers was assumed,
boxes at time zero, - Catastrophic failure assumes all material - Results in overestimated peak
barrels at 100 yrs available for transport. In fact. plastic concentrations
liners could retard migration for hundreds
to thousands of years even when tom and
partially decomposed.
~
..,
~
-------
Uncertainty Estimate of Type & Degree Effect of Conservatism on BRA Results
Groundwater Modeling (Cont.)
- Contaminants assumed
uruformly distnbuted CONSERVATIVE - LOW to MODERATE
over source area
Radionuclides
This assumption allows all water which - Peak contaminant concentrations are
enters source area to come in contact with overestimated
contaminants. In fact. a significant
volume of water entenng contamination
zone will not contact contaminants
Nitrates
This assumption allows all water which - None
enters source area to come in contact with
contaminants
- Equivalent we!! screen - Contaminant is verucally mixed over the
thickness versus GWSCREEN equivalent weil screen
contarrunant thickness. see specific cases below
concentrations (re:
Engineering Design FiJe
SEM-RWMC-91-002. R.
R. Seitz)
Pad A Boundary (average NOT CONSERVATIVE - LOW If the contaminant plume remains in the
residential weil screen upper 12 m of the aquifer. peak
depth is assumed to be 12 concentrations could be under-estimated
m [40 ft] - a 25 m we!! by a factor of 2
screen depth was modeled
in the BRA)
Pad A Boundary (average CONSER V A TIVE - LOW Peak concentrations could have been
agricultural we!! screen overestimated by a factor of 2
depth is 46 m [150 ft] - a
25 m we!! screen depth
was modeled in the BRA)
WAG 7 Boundary (average NOT CONSERVATIVE - LOW If the contaminant plume remains in the
residenual well screen upper 12 m of the aquifer. peak
depth is 12 m - 65 m was concentrations could be under-estimated
modeled) by a factor of 5
WAG 7 Boundary (average NOT CONSERVATIVE - LOW If the contaminant plume remains in the
agricultural we!! screen upper 46 m of the aquifer. peak
depth is 46 m - 65 m was concentrations could be under-estimated
modeled) by a factor of 1.4
INEL Boundary (average NOT CONSERVATIVE - LOW If the contaminant plume remains in the
residential weil screen upper 12 m of the aquifer. peak
deptb is 12 m - 76 m was concentrations could be under-estimated
modeled) by a factor of 6
INEL Boundary (average NOT CONSERVATIVE - LOW If the contaminant plume remains in the
agricultural well screen upper 46 m of the aquifer. peak
depth is 46 m - 76 m was concentrations could be under-estimated
modeled) by a factor of 1.7
- Radionuclide hydroxIde NOT CONSERVATIVE - LOW
formation and effects on
mobility - Am and Pu may exist in the form of - Peak contaminant concentrations for
hvdroxides in the nitrate salts. The effects Am and Pu mayor may not be
- on the mobility of these hydroxide forms underestimated
(specific to Pad A contaminants) are
unknown.
42
.
.
~
-------
'"
Uncertainty Estimate of Type & Degree Effect of Conservatism on BRA Results
Food crops evaluation
- Use of B. values CONSERVATIVE - LOW
- for children. peak concentrations used - Results in higher HQ values for
instead of 25- or 30-year averages (due to infants/children
the exposure duration being so short) --
Exposure parameters
- EP A values CONSERVATIVE - MODERATE
- EPA exposure values are conservative by - Results in higher exposure values for all
default and Pad A exposure values used are receptOrs
EP A recommended values
Land use scenarios
- Occupational scenarios CONSERVATIVE - LOW
- due to conservatism comained in the EP A - Results in higher exposure values for
default parameters institUtional scenario
- FutUre scenarios (i.e.. CONSERVATIVE - LOW
residential well at edge of
OU. WAG. and INEL - all relevant contaminants detennined to - Same as above
boundaries reach the aquifer are presem during the
same time period
- Inuusion scenarios NOT CONSERVATIVE - MODERATE TO
HIGH
- intrUSion scenarios only qualitatively - An intrUSion scenario mayor may not
discussed and it is stipulated that any result in increased risk above that
prolonged exposure to Pad A contaminants calculated for the assumed scenario.
will present a risk to human health depending upon the intrusion scenario
(i.e.. time of exposure to contaminants.
etc.)
Lack of toxicity values for NOT CONSERVATIVE - LOW
some chemicals
- qualitative analysis was performed for . None
substances lacking EPA toxicity values
using occupationallimits/standards--and the -- -.
media concentrations for these contaminants
-. are very low (with no expected health
hazards as a result)
..
Toxicity assessment
- EP A values CONSERVATIVE - MODERATE
- high-dose to low-dose extrapolation of - Results in higher toxicity values for
adverse effects. extrapolation from animal receptors
stUdies. short-term to long-term exposure.
and difference in population sensitivities
Assumption of do~_?d~tivity
- No synergism or NOT CONSERVATIVE - LOW TO
antagonism MODERATE
- may underestimate or overestimate risks; . None
EP A suggests risks are to be treated as
additive since necessary data to assess these
intet':lCtions are r:lrely available
.
:1
~
-------
Uncertainty Estimate of Type & Degree Effect of Conservatism on BRA Results
Acrual probability of receptor For all receptor locations and scenarios. the
locations risks depend on the likelihood of access to the
comanunants and the period of exposure.
- Pad A boundary for CONSERVATIVE - MODERATE
infant/childladult
- the probability of a residence being - Results in higher exposure values for
established in this portion of the INEL is residential receptors since groundwater
extremely low based on currem wells are locared in maximum plume
demographic trends and eXIsting knowledge concentrations
of the sIte
- Assumes that the resident living at the edge - Results in higher exposure values for
of the boundary has an infant or child at the residential receptors since groundwater
same time the peak mtrate concentration wells are located in maximum plume
occurs In the groundwater concentrations
- WAG 7 boundary for CONSERVATIVE - LOW
infanclchildladult
- See previous item - Same as above
- INEL boundary for CONSERVATIVE - LOW
infanclchildladult
- See previous item - Same as above
lnstirutional control issues
- Likelihood of INEL NOT CONSER V A TIVE - LOW
becoming National
Park/Reservation - instirutional control will be maintained - None
under existing regulations and orders and
the length of time of comrol may be
extended
- INEL available for use NOT CONSERVATIVE - LOW
prior to 100 yr instirutional
conrrol period - no public use of INEL is assumed during - None
the instirutional conrrol period based on
existing DOE orders and other regulations. -
6.3 Basis for Response
Threatened releases of, and prolonged direct contact with, hazardous substances from
this Site, if not addressed by implementing the response action selected in this ROD, may
present a potential threat to public health, welfare, or the environment at the boundary of
Pad A.
7. DESCRIPTION OF ALTERNATIVES
7.1 Remedial Action Objectives
The risk assessment indicates that there is no current risk to workers or the public
from Pad A. -However, fate and transport modeling indicated a potential future risk in
approximately 250 years due to exceedances of drinking water standards for nitrate if
residents used the groundwater directly adjacent to the Pad A boundary. This fate and
transport modeling used conservative assumptions in order not to underestimate risks. Actual
nitrate concentrations in groundwater are not expected to exceed drinking water standards at
44
.
11
..
-------
the WAG 7 boundary and, therefore, Pad A is not expected to pose an unaeceptable risk to
human health or the environment now or in the future. .
.
Ji
The results of investigation and risk assessment indicate that the existing Pad A cover
is a protective barrier for the Pad A contents; however, although not quantitatively evaluated,
prolonged direct contact with Pad A waste would likely pose an unacceptable rlsk.
Consequently, the focus of the remedial action objectives and the alternative development was
on maintaining the effectiveness of the existing cover to prevent direct exposure-to the wastes
and to rninirni7.e the potential for contaminant migration from the pad to surface water or
groundwater. The alternatives developed were also designed to address the uncertainty
associated with the fate and transport modeling and with future land use assumptions by
including environmental monitoring and institutional controls to restrict access.
Remedial action objectives also include the identification of preliminary remediation
goals that are established based on both risk and on frequently used standards or ARARs.
The nitrates at Pad A have been reviewed against 40 CPR 261.21(a)(4) and 49 CPR 173.151
and appear to exhibit the properties of an oxidizer. It is recognized that this type of oxidizer
can have the characteristic of ignitability. The RCRA closure requirements are applicable
when (a) the waste is hazardous and (b) the unit received the waste after RCRA requirements
became effective. Pad A does contain RCRA hazardous waste but the waste was placed from
1972 through 1978, before RCRA requirements became effective; therefore, RCRA closure
requirements are not applicable to the wastes in Pad A. However, certain RCRA closure
requirements in 40 CPR Subpart N, specifically ~264.31O, are considered to be relevant and
appropriate. Because the residual contamination in the pad may pose a direct contact threat,
but is not expected to pose a groundwater threat, relevant and appropriate requirements
include: (a) a cover, which may be permeable, to address the direct contact threat; (b) limited
long-term management including site and cover maintenance and groundwater monitoring;
and (c) institutional controls (e.g., land-use restrictions or deed notices) to restrict access.
The remedial action objectives would be. achieved by implementing the general .
response actions described below. Alternatives were subsequently developed based on these
general response actions.
.
Containment with a cover that:
Provides long-term minimization or migration of liquids through the pad
(e.g., with an infiltration rate of less than 5 cm/yr);
"
Functions with minimum maintenance;
Promotes drainage and rninirni7.es erosion or abrasion of the cover;
...
Accommodates settling and s.ubsidence such that the cover integrity is
maintained; and
Has a permeability less than or equal to the permeability oJ any bottom
liner system or natural subsoils present.
-------
.
Maintenance of the cover integrity and effectiveness including making repairs
to the cap as necessary to correct the effects of settling, subsidence, erosion,
and other events and to prevent run-on and run-off from eroding or otherwise
damaging the cover.
.
.
Environmental monitoring of air, groundwater, and surface water/sediments to
provide early detection of a potential release to subsurface, groundwater, or
surface pathways.
11..
.
Institutional controls such as access and land use restrictions to prevent
intrusion into the wastes. The restrictions would prevent activities occurring
that allow direct exposure to contaminants in Pad A wastes.
7.2 Summary of Alternatives
In accordance with Section 121 of CERCLA, the Feasibility Study identified
alternatives that (a) achieve the stated remedial action objectives, (b) provide overall
protection of human health and the environment, (c) meet ARARs, and (d) are cost-effective.
The alternatives evaluated in the FS for Pad A were Alternative 1 - Containment,
Alternative 2 - Limited Action, and Alternative 3 - No Action. Descriptions of each
alternative are provided in the following sections.
Each of the alternatives evaluated considers leaving the wastes in place and involves
utilization of a cover or cap to continue to effectively isolate the wastes. Other alternatives
such as excavation, treatment, and disposal were not evaluated because the results of the
investigation and the risk assessment indicated that the Pad A wastes would not..pose an
unacceptable risk if left in place assuming prolonged direct contact with the waste is
prevented. Consequently, the impacts/effects for each of the alternatives are similar, as are
the regulatory requirements. Therefore, the ARARs for each of the alternatives are the same.
Refer to Table 14 for a summary of ARARs and to-be-considered (TBC) criteria for the
alternatives.
7.3 Alternative 1 - Containment of Pad A Materials
Two subalternatives were developed and evaluated in the detailed analysis. One
sub alternative involves construction of a composite earthen material cover to be placed
directly over the existing Pad A cover. Several combinations of different earthen material
types were evaluated within this alternative using layers of clay, soil, rock and/or sand. A
cross-sectional view of several containment options under this sub alternative is represented in
Figure 11. It is estimated that a composite earthen cover would require 10 to 15 workers
approximately 66 weeks to complete construction. Construction and 30 years of monitoring
costs are estimated to range from $1.8 million to $2.3 million.
It
.
The other sub alternative evaluated would involve construction of an earthen/synthetic
material cover over the existing waste pile using clay, gravel, and a plastic flexible membrane
liner. It is estimated that an earthen/synthetic cover would require 10 to 15 workers 60 weeks
to complete construction. Construction and 30 years of monitoring costs are estimated at $2.4
million.
-------
Table 14.
/If
Statute
HWMA
..
IDAPA
Summary of ARARs and TBC criteria for Pad A alternatives.
Regulation
Alternative I Alternative 2
Containment Limited Action
R R
A A
TBC TBC
TBC TBC
TBC TBC
TBC TBC
Closure and Post-Closure Care - Landfill Closure IDAPA H6.0I.05008
(40 CFR 264.310)
IDAPA ~16.01.01.01251 and ~16.0I.Ol2S2 (Rules for Control of
Fugitive Dust)
RCRA ARARs: Focus on Closure Requirements. OSWER
9234.2-04FS. October 1989.
Evaluating Cover Systems for Solid and Hazardous Waste (Revised),
OSWER 9476.00-1, .September 1982.
DOE 5820.2A. Radioactive Waste Management
DOE 5400.5. Radiation Protection of the Public and the Environment
A
R
TBC
=
Applicable
Relevant and Appropriate
To-Be-Considered
=
=
Both of the subalternatives would be capable of being placed directly over the existing
Pad A wastes and soil cover. This alternative ensures that the entire volume of Pad A wastes
(13,341 yd3) that remains in place is effectively isolated with an impermeable cover of
composite design. These subaltematives provide continuing isolation of the Pad A wastes
from the environment at the surface and protection of human health and the environment.
These subalternatives ensure continued protection by preventing contamin~t migration to
groundwater and reducing the accessibility of Viaste materials at th~ surface of the cover.
Certain RCRA closure requirements in40 CPR 264 Subpart N are considered to be
relevant and appropriate with respect to the waste materials remaining on Pad A. Under this
alternative, Pad A would be closed and managed in accordance with the substantive relevant
and appropriate requirements of 40 CFR ~264.310 - Closure and post-closure care.
~
Institutional controls (i.e., access/land use restrictions) would be continued under this
alternative to maintain protection of human health and the environment. The controls would
restrict activities occuning onsite that allow direct exposure to contaminants in Pad A.
..
Because-this alternative leaves wastes in place, long-term monitoring (for groundwater,
soil, surface water, and air) would be conducted to provide early detection of a potential
release to the subsurface, groundwater, or surface pathways. Additionally, infiltration rates
will be monitored to ensure the effectiveness of the cover.
-------
Opllon 11 Clay/Soli Cover
Opllon 2: Clay/SolVUock Cover
+>-
00
6 loch Rod< Covel (Cot>bl8)
~1I1d. SOW lavol
2~ Wid. Clav I avo,
30 wldl Top~oIVSo~ llvel
E.I~IIIIQ Poll A So~ Covel
O(lllon 3; Clay/nock/Soll Cover
Opllol\ 4; ChlylSlIIlIlISoil Cover
Figure 11. Cross-sections of composite earthen material cover options.
..
'I
'"
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7.4 Alternative 2 - Limited Action
--
Under Alternative 2, actions would focus on recontouring, subsidence correction, and
continued maintenance of the existing soil cover. This alternative is intended to contain the
Pad A waste 'materials, to prevent exposure of these materials through erosion by wind or
water, and to limit the inf1lcration of rainwater through the waste. The overall. cost for
upgrading the existing soil cover, continued maintenance, and 30 years of monitoring is
estimated at $1.7 million.
t
This alternative ensures that the entire volume of Pad A wastes (13,341 yd3) that
remains in place is effectively isolated with a protective soil cover. Thi_~ alternative provides
continuing isolation of the Pad A wastes from the environment at the surface and protection
of human health and the environment. The placement of additional soil material for .
contouring and maintenance of this soil cover will provide continuing isolation of the waste,
thus minimizing the potential for direct exposure of the waste to the environment via erosion
andlor biotic transpon. Alternative 2 ensures continued protection by preventing contaminant
migration to groundwater and reducing the accessibility of waste materials at the surface of
the cover.
Cenain RCRA closure requirements in 40 CFR 264 Subpart N are considered to be
relevant and appropriate with respect to the waste materials remaining on Pad A. Under this
alternative, Pad A would be closed and managed in accordance with the relevant and
appropriate requirements of 40 CFR ~264.310 - Closure and post-closure care. .
Institutional controls (Le., access/land use restrictions) would be continued under this
alternative to aid in protecting human health and the environment. The controls would
restrict activities occurring onsite that allow direct exposure to contaminants in Pad A.
Because this alternative also leaves wastes in place, and long-term monitoring (for
groundwater, soil, surface water, and air) would be required to provide early detection of a
potential release to the subsurface, groundwater;'or'surface pathways;- Additionally;'" .
infiltration rates will be monitored to ensure effectiveness of the existing cover.
7 .s Alternative 3 - No Action
..
Under this alternative, no action other than groundwater, surface water, air, and soil
monitoring would be implemented. All wastes currently in place on Pad A are assumed to
remain on the pad with no correctiv~ action or maintenance implemented for the existing soil
cover. This alternative was a "baseline" case against which the other alternatives were
compared and does not include the use of institutional controls to prevent uncontrolled access
to the site nor....does it address the uncenainties associated with the BRA.
..
Long-term monitoring (for groundwater, soil, surface water, and air) would be also be
conducted for this alternative to provide early detection of a potential release to the
subsurface, groundwater, or surface pathways. Monitoring costs for the next 30 years are
estimated at $692,000.' .
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8. SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
CERCLA guidance requires that each remedial alternative be compared according to
nine criteria. Those criteria are subdivided into three categories: (a) threshold criteria that
relate directly to statutory fmdings and must be satisfied by each chosen alternative;
(b) primary balancing criteria that include long- and short-term effectiveness,
implementability, reduction of toxicity, mobility, and volume, and cost; and (c) modifying
criteria that measure the acceptability of the alternatives to State agencies and the community.
The following sections summarize the evaluation of the candidate remedial alternatives
according to these criteria.
.
.
8.1 Threshold Criteria
The remedial alternatives were evaluated in relation to the threshold criteria: overall
protection of human health and the environment and compliance with ARARs. The threshold
criteria must be met by the remedial alternatives for further consideration as potential
remedies for the ROD. .
8.1.1 Overall Protection of Human Health and the Environment
This criterion addresses whether a remedy provides adequate protection of human
health and the environment and describes how risks posed through each exposure pathway are
eliminated, reduced, or controlled through treatment, engineering controls, or institutional
controls.
Each of the remedial action alternatives satisfies the criterion of overall protection of
human health and the environment. The alternatives provide protection by minimizing the
risk of potential contaminant migration to the groundwater and by maintaining the
inaccessibility of the Pad A waste materials, thereby preventing direct exposure to the wastes.
8.1.2 Compliance with ARARs
CERCLA, as amended by the SARA, requires that remedial actions for Superfund sites
comply with federal and state laws that are applicable to the action being taken. Remedial
actions must also comply with the requirements of laws and regulations that are not directly
applicable but are relevant and appropriate, in other words, requirements that pertain to
situations sufficiently similar to those encountered at a Superfund site so that their use is well
suited to the site. Combined, these are referred to as ARARs. State ARARs are limited to
those requirements that are (a) promulgated, (b) unifonnly applied, and (c) and are more
stringent than federal requirements. Compliance with ARARs requires evaluation of the
remedial alt~rnatives for compliance with chemical, location, and action-specific ARARs or
justification for a waiver.
.
..
ARARs are identified for each alternative considered at the Pad A unit under the
Description of Alternatives (Table 14 in Section 7). All alternatives would be designed to
meet the identified ARARs for this unit, with the exception that the No Action alternative
does not include institutional controls.
-------
8.2 Balancing Criteria
.
Once an alternative satisfies the threshold criteria. five balancing criteria are used to
evaluate other aspects of the potential remedial alternatives. Each alternative is evaluated
using each of the balancing criteria. The balance criteria are used in refining the selection of
the candidate alternatives for the site. The five balancing criteria are: (1) long-:term
effectiveness and pennanence; (2) reduction of toxicity, mobility, or volume through
treatment; (3) short-term effectiveness; (4) implementability; and (5) cost. Each criterion is
further explained in the following sections. Table 15 includes a summary of the comparative
analysis (relative ranking) of the alternatives.
.-
8.2.1 Long-term Effectiveness and Permanence
This criterion evaluates the long-term effectiveness of alternatives.in maintaining'
protection of human health and the environment after remedial action objectives have been
met.
Alternatives 1 and 2 provide long-term effectiveness and pennanence because the
existing cover and composite earthen material and earthen/synthetic material cover options
provide for reliable isolation of the Pad A when combined with institutional controls. A
degree of residual risk would remain, however, as the waste material would not be removed
from Pad A.
The No Action alternative would likely provide a lower level of long-term
effectiveness and permanence because of the lack of cover maintenance and the potential for
future uncontrolled erosion and subsidence.
Table 15. Evaluation of alternatives
Criteria
Alternative 1 Alternative 2
Containment Limited Action
BEST BEST
N/Aa N/Aa
GOOD GOOD
GOOD BEST
GOOD BEST
Long-term effectiveness
Reduction of toxicity, mobility, or volume
through treatment
Short-term effectiveness
1t,
Implementability
Cost
.....
a. No treatment alternatives were evaluated
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8.2.2 Reduction of Toxicity, Mobility, or Volume through Treatment
This critenon addresses the statutory preference for selecting remedial actions that
employ treatment technologies, which permanently reduce toxicity, mobility, or volume of the
hazardous substances as their principal element.
,
The Pad A investigations and risk assessment indicated that maintenance of the
existing cover would reliably control Pad A wastes in place; therefore, no treatment
alternatives were evaluated.
.
8.2.3 Short-term Effectiveness
Short-term effectiveness addresses the period of time needed to achieve protection and
reduce any adverse impacts on human health and the environment that may be posed during
the construction and implementation period until cleanup goals are achieved.
In general, alternatives requiring the least amount of worker interface (i.e.,
construction and/or operations) and Pad A waste handling rank the highest in terms of short-
term effectiveness.
Alternatives 1 and 2 rank equally under this criterion since they do not require
handling of the Pad A wastes. No increase in potential risk to the public would occur
because the Pad A waste will not be disturbed under either of these alternatives. Alternative
1 may require more time to complete than Alternative 2 based on the complexity of the
design of the containment cover.
8.2.4 Implementability
The implementability criterion has the following three factors requiring evaluation:
(a) technical feasibility, (b) administrative feasibility, and (c) the availability of services and
materials. Technical feasibility requires.an-evaluation .of the ability.to construct and operate-,
the technology, the reliability of the technology, the ease of undertaking additional remedial
action (if necessary), and monitoring considerations. The ability to coordinate actions with
other agencies is one factor for evaluating administrative feasibility, and the agencies have
demonstrated this throughout the project to date. Other administrative activities that would be
readily implementable include planning, use of administrative controls, and personnel training.
In terms of services and materials, an evaluation of the following availability factors is
required: necessary equipment and specialists, prospective technologies, and cover materials.
Each of the alternatives retained for detailed analysis is readily implemer;table.
However, Alf.ernative 1 ranks slightly lower than Alternative 2 and the No Action alternative
because of the increased difficulty of installing and maintaining the multi-layered cover
systems.
.
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8.2.5 Cost
.
In evaluating project costs, an estimation of capital costs, operation and maintenance
costs, and pr~sent worth costs is required. In accordance with the RI/FS guidance, the costs
presented are estimates (Le., -30% to +50%). Actual costs could vary based on the fmal
design and detailed cost itemization. The cost estimates for these alternatives are listed in
Table 16.
,
8.3 Modifying Criteria
The modifying criteria are used in the fmal evaluation of remedial alternatives. The
two modifying criteria are state and community acceptance. For both of these criteria, the
factors that are considered include the elements of the alternatives that are supponed, the
elements of the alternatives that are not supponed, and the elements of the alternatives that
have strong opposition.
8.3.1 State Acceptance
The IDHW concurs with the selected remedial alternative, Limited Action. The
IDHW has been involved in the development and review of the RI/FS repon, the Proposed
Plan, this ROD, and other project activities such as public meetings. Comments received
from IDHW were incorporated into these documents, which have been issued with IDHW
concurrence.
Table 16. Pad A alternative cost estimates (in present dollar value)
Alternative 2
Cost Elements Alternative 1 - - Limited Alternative 3
Containment' Action - No Action
Consttuction & Consttuction . $7?3,989 . .$435,105.. 0
. .
Operations
Post-Closure Maintenance & $707,133 $707,133 $691,760
30 years Monitoringb
Indirects $831,678 $547,381 $155,646
Contingency $687,750 $506,886 $254,222
11, TOTAL $2,980,250 $2,196,506 $1,101,628
.+
a. Represents average cost of the five options considered under Alternative 1.
b. Net present value calculated using a 5% discount value.
-------
8.3.2 Community Accept4lnce
This assessment evaluates the general community response to the proposed alternatives
presented in the Proposed Plan. Specific comments are responded to in the Responsiveness
Summary ponion of this document.
,
Eleven individuals provided written comments on the Pad A Proposed Plan during the
public comment period. One written comment was received after the comment period ended.
Nine individuals also provided oral comments at the public meetings held in Idaho Falls.
Boise, and Moscow. Public opinion on the preferred alternative, in no panicular order.
included (a) Alternative #1 should have been selected, (b) Limited Action was the best
alternative presented. (c) cumulative, INEL-wide risks should have been evaluated,
(d) catastrophic future events were not addressed adequately, (e) long-term control of the site
cannot be guaranteed, (f) control of public meetings needs to be improved, and (g) treatment
and removal of the Pad A wastes from the site should have been evaluated and selected.
Additional comments were provided requesting additional technical information, or concerns
about the integrity of containers and the current Pad A site. In general, public opinion was
split between those in favor of the preferred alternative, those in opposition, and individuals
requesting additional, or clarifying information.
.
9. SELECTED REMEDY
Based upon consideration of the requirements of CERCLA, the detailed an<;lysis of
alternatives, and public comments, DOE-ID, EPA, and IDHW have selected Alternative 2 -
Limited Action as the most appropriate remedy for Pad A, OU 7-12 at the RWMC. The
BRA indicates that there is no current risk to workers or the public from Pad A. The fate and
transpon modeling indicated a potential future risk in approximately 250 years due to
exceedances of drinking water standards for nitrate if residents used the groundwater directly
adjacent to the Pad A boundary; however, this fate and transpon modeling used conservative
assumptions in order not to underestimate risks. Actual nitrate concentrations in groundwater
are not expected to exceed drinking water standards at the'WAG7- boundary:-therefore,'- .
Pad A is not expected to pose an unacceptable risk to human health or the environment in the
future. Although not quantitatively evaluated, prolonged direct contact with the Pad A wastes
would likely pose an unacceptable risk. Alternative 2 - Limited Action was therefore selected
to address uncenainties associated with the fate and transpon modeling and future land use
around the RWMC, in order to maintain existing conditions and continue to restrict access to
Pad A in order to prevent direct contact with the wastes.
9.1 Limited Action Description
..
The major components of Alternative 2 - Limited Action include recontouring and
slope correction, institutional controls, and maintenance and monitoring of the existing cover
at Pad A. The selected alternative is believed to provide the best balance of trade-offs among
the alternatives with respect to the nine CERCLA evaluation criteria. DOE-ID, EP A, and
IDHW believe the preferred alternative is protective of human health and the environment,
complies with applicable federal and state regulations, and is cost-effective. .
.
-------
.
Maintenance will include subsidence and erosion control of the Pad A cover.
Monitoring will continue to be conducted at Pad A to ensure the effectiveness of the existing
cover. Groundwater, air, surface water, and soil monitoring will be designed and conducted
to provide early detection of a potential release to the subsurface, groundwater, or surface
pathways and 'ensure continued effectiveness of the soil cover.
"
Institutional controls (i.e., accesslland use restrictions, controlling public' 'access,
posting signs, and erecting/maintaining barriers or fences) would be continued under this
alternative to aid in protecting human health and the environment. The restrictions would
reduce the likelihood of activities occurring onsite that allow direct exposure to contaminants
in Pad A.
Because this remedy will result in wastes ,remaining onsite, maintenance and
monitoring of Pad A will continue. Independent reviews of the mainten~ce and monitoring
data will be conducted by EPA and IDHW. This evaluation will be conducted within two
years of ROD signature, and every five years thereafter, to ensure that the remedy continues
to provide adequate protection of human health and the environment.
9.2 Remediation Goals
The purpose of this response action is to continue to prevent exposure to the wastes
disposed at Pad A. This will be accomplished by maintaining the existing cover and
continuing to restrict access to Pad-.A in order to prevent direct contact with the wastes.
Performance standards will be implemented to ensure that the cover continues to
provide protection against direct exposure to Pad A wastes. The performance standards
identified for Limited Action include (a) maintaining the soil cover to prevent excessive
infiltration thereby providing continued protection of groundwater, and (b) ensuring erosion is
monitored and controlled to limit soil loss such that the inmtration rates are not affected and
the potential for exposing wastes is eliminated. The inspection and maintenance of the soil
cover will be conducted concurrent with- themoni:toringl'rogram:--Implementation 'of the' .~. "
maintenance an,d monitoring programs will ensure that the Pad A site continues to protect
human health and the environment from any unacceptable risks.
'1'1,
For those remedial actions that allow hazardous substances to remain onsite, Section
121(c) of CERCLA requires that a review be conducted of the remedy within five years after
initiation of remedial action and at least once every five years thereafter. The purpose of this
review is to evaluate the remedy's performance - to ensure that the remedy has achieved, or
will achieve, the remedial action objectives set forth in the ROD and that it continues to be
protective of human health and the environment.
~
Monitoring data (groundwater, air, surface water, and soil) will be collected at Pad A
and evaluated by the EP A and IDHW within two years of signing the ROD. This monitoring
will be implemented to provide a baseline against which future site characterization can be
compared, to provide early detection of a potential release to the subsurface, groundwater, or
surface pathways, and to ensure continued effectiveness of the soil cover.
. .
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9.3 Estimated Costs for the Selected Remedy
A summary of the costs for each of the action alternatives was presented in Table 16.
Table 17 provides a detailed breakdown of the estimated costs (i.e., $2.2 million) related to
the Limited Action alternative. Costs for maintenance and monitOring of the Pad A site are
the Net Present Value (NPV) dollars for 1992, using a 5% discount rate. These costs are
calculated using NPV since they extend several years into the future.
.
.
10. STATIJTORY DETE&.\1INATIONS
Remedy selection is based on CERCLA, as amended by SARA, and the regulations
contained in the NCP. All remedies must meet the threshold criteria established in the NCP:
protection of human health and the environment and compliance with ARARs. "'CERCLA also
requires that the remedy use permanent solutions and alternative treatment technologies to the
maximum extent practical and that the implemented action must be cost-effective. Finally,
the statute includes a preference for remedies that employ treatment that permanently and
significantly reduce the volume, toxicity, or mobility of hazardous wastes as their principal
element. The following sections discuss how the selected remedy meets these statutory
requirements.
10.1 Protection of Human Health and the Environment
As described in Section 9, the selected remedy satisfies the criterion of overall
protection of human health and the environment by minimizing the risk of potential
contaminant migration to groundwater and by preventing direct contact with the Pad A waste
materials. The remedy will ensure that cumulative carcinogenic risk levels are maintained
within the NCP risk range (1 additional cancer in 10,000 to 1 additional cancer in 1,000,000),
and the cumulative hazard index is maintained less than 1.
The selected remedy will upgrade the existing cover to improve the cover slope and
contours. The cover will be designed to- incorporate erosion control-measures to reduce the _.
effects from rain and wind. The selected remedy ensures that the Pad A cover receives
maintenance which includes subsidence correction and erosion control. Monitoring of Pad A
will continue and will include sampling of water, air, and soils at Pad A to ensure the
effectiveness of the existing cover and the protection of groundwater. The agencies will
continue to review the action, within two years, and at least every five years thereafter, to
ensure that human health and the environment are being protected. Additionally, institutional
controls (i.e., accesslland use restrictions, controlling public access, post;ng signs, and
erecting/maintaining barriers), will be implemented to prevent direct exposure to wastes. No
short term risks will be incurred as a result of this remedy.
..
10.2 Compliance with ARARs
..
The selected remedy of limited action will be designed to meet all ARARs of federal
and state regulations. The ARARs that will be achieved by the selected alternative follow.
-------
~
"
1(.
~
Table 17. Limited action detailed cost estimate.
Item
REMEDIAL ACTION
CONSTffuCTfOi,f--- ---
-Wiii8-rTankiOust ConI.
.--1!!!'Jted aclio!:!:gr!-~!~9-
Graded fill material
VegetalionlseedllllL
Qt.
Unit
Sub-
contract
Source 2
Mat'l
Bare Costs
----LabOr-'-- -- ---Eur--
Sub-
contract
Total
Cost
---
----
--- --------- ---.------. ------- --. .
. 320 hr
- --
26.04
$15.03 .
0164206900 --
$0' ---$-~~33~' -._- $4,810 --'---"0 '----$f~~Hg
------... --
19000 c'
. 138 msf
. $2.15
. 3
029 308 2300
$0 ------$O------$(j" -~40 850 '---$-4Q~~Q
.. $996 . $9!!. $863 $0 $2J??Q
$7.22 - '. $6.60
6.25
-I!!yerslon ditches -1~gQ. -1L . $2:Q!! {~L_- $Q--=:]Q" :_---~Q' . $31Q1Q =--. '~~B~
-_f.~!!£!!!9- . -- -1J!Q!! _J!.... --. -jg~QQ IN!;h.co~!~.~!:- . ~Q.__.__._.__.~Q ----.._.__._---_..~Q .__.---__!1~IQQQ____~1~!QQ()
2!9~ge . _!~. e!.. $33.00 14.65 .. J04 ~04 !gQQ- $594 --_~?~1___~ . $0 ----~!!~~
-_J~Q~!!!za!~!'L_--~__- ~'r~Q'const!.uc!~~ . ~8!~fuM!ft.. ',~V":&h.~\1'i/Ah'~; $!!Q ------- . $47~ .... _...$g~4_._-__.i4.44~ . _.._-_.$~,?~P
~l!~TQT~l qON~!'l!9TIQt<._- -- -- ,~!i' lIK!i!<\ ~"'it\. IIIJ1:'l ::-$9,.83 r-:- --$5,~~~ ::-:=$~~;~~ =-- $fj~;943
~~~~~f:~I-- ~~ff ::"-$38_5~ --~-:}l~;ggQ i~M"j;mF ==-$~-=iiZ~;~~~-~=~":=~=J?~,9~ "::'-:*m:~~
SUBTOT AL OPER~ T!O~~ ~,yYi ,~/f-m '\I?;~;<,\/:;nll____$Q L____.$I7~:~~g 1.._. .-- . -- --- $9 L -.--. $7Q.QQQIL.__- $?4~;~3?
~ ~~~TQTAL.~QN~TBUCT!Q~t~uQPERAT!QN~ ,. ..u... ._..:'''::i:~:I--- $_M. ?Qf.---. ~i..~~;~!~ -='.'-'$.~~~~ -. -.--.-.-~.1.~-~;.~. .~.~ -~'---.-J.~~~;~!!)
Q~~!h~ad & PronL- g~'r~Qt!~!'1eQlal_action ... ".;w;>j~jr:;'.:;- .:.".... -_~~~.4 ~-'~?,1?~. _.-~-:..,..~h1~!'7:'='C,~~~,~~? -_.__.~!1,~~5
G&A 5Yoolmaterlals ,.... $83 "... :'.. .'. . . :,. .-;,::.""';':';{:;(';:".::'"'i.:. $83
80-nc1"& I!\sura!'lce -.-.-- g%.Q!j~~~!~r~~!lon- -- '~ . :;i ~:":"-==~:$~~ ------._$~712 .... .. $11Q .- ---_.$~,g~7 -~.- .~.~.. $7,1:31
$V~TQt A.';:~~M!;P'!Ak"CTION DIRECT COSTS . '-'»?i".;:C:'';-::. r-----$-2"T21 r,--u'22ff450-" -. . ---$i 266 --- - - -19~f268 r-'-"'-$43!d05
.---..- POST:CLosiiRE .-..
O&M- - - --- --- -_u - - . --- --~- -----
AnJ!uallnspJenv. monlt. - 30 r
Land surface care ~!! _yr
SUBTOTAL POST-CLOSURE DIRECT COSTS
SUBTOTAL DIRECTS---':;;;F;S;T JI.tt\{ ~r;;;~.'ii; n.
---iNDiAECTS" ----
ConsiiuciiOii Mgmt- _17.1 %ofremedlal action' .
EQ~! . 35%.01 r~m~~~l!~!lon
~!Qj~ct ~~nagement 22.5% ot dlrect.costs
M~~~9~!!,ent Bes!rve - J~i.~'Yo ,of r!~e~~',~~.!!~n & CM
~~~:rOT~L INDI!!ECTS ~,;E':'<';,;f;'!i:'¥H~iJj ;;l;lfJiJ1;ihi~
SUBTOTAL DIRECTS & INDIRECTS 1;1iC,,~t,
Q~~g~n~y ----'-I~o/;--
TOTAL ESTIMATED COST
Notes: .
(1)Asterlsk Indicates labor rate Is Increased by a factor of 2 due to hazardous level B work and heat stress.
(2) Numbers Indicate unit prices used from 1991 Means Cost Data; Names Indicate company who provided estimate.
(3)Research report on landlill costs by Creative Ventures, LId.
jit$~r- mij ----lun;;;mlF~Jii1nr;~]IH!
INEL c.ost est. $.319. ------- $~~, 147 ----- .__$.1.Q~4 E. ----- ~g!l,1~!!. ...--- i~~,~~~
Iijm~~ L $1.!!QgC__.. $~Q?;Q7Q C-.~~- $$.;4~Hr~_~$~~[~;mr=$~1?;~Q1
I $4-0131-- $42(f5281---'~--$13'75(fl-$f243-32811'-'-$-(68!f 619
!N!;L cQ~L!~:- ~-_3j:gQ4 -==~-~$.'j?ij:~~~ . .~~h~-~4:1g~ '-'_::._-=-i~ig:~~~-h:.:__~.i~Q~:8~6
-------
10.2.1 Chemical-specific ARARs
No chemical-specific ARARs are identified for the selected remedy.
,
10.2.2 Action-specific ARARs
Certain substantive IDAPA closure and post-closure requirements [IDAPA
916.01.05008 (40 CPR 264.310)] will be met for closure and post-closure care of Pad A. The
relevant and appropriate requirements specify standards for fmal cover requirements, cover
maintenance, and monitoring of Pad A following closure.
III
The relevant and appropriate substantive requirements of the rules for the Control of
Fugitive Dust (IDAPA 916.01.01251 and IDAPA 916.01.01252), which specify that all
reasonable precautions be taken to prevent the generation of fugitive dusts, must be complied
with.
10.2.3 Location-specific ARARs
No location-specific ARARs are identified for the selected remedy.
10.2.4 To-Be-Considered Guidance
In implementing the selected remedy, the agencies have agreed to consider a number
of procedures or guidances that are not legally binding. The following are to be considered
guidance documents:
.
DOE 5820.2A, "Radioactive Waste Management"
.
DOE 5400.5, "Radiation Protection of the Public and the Environment"
.
OSWER 9234.2-04FS, October 1989, "RCRA ARARs: Focus on Closure - .
Requirements "
.
OSWER 9476.00-1, September 1982, "Evaluating Cover Systems for Solid and
Hazardous Waste" (Revised)
DOE Order 5820.2A addresses future control of the site and provides the requirement
that DOE maintains active institutional control of low-level radioactive waste disposal sites
for 100 years following closure (in this case, closure of the SDA). Institutional controls that
would be implemented to continue control of the facility may include, but are not limited to,
deed restrictions .on future land use, controlling public access, posting signs, and erecting
barriers or fences. DOE Order 5400.5 provides radiation protection standards for the general
public from activities conducted at DOE sites. The OSWER directives provide additional
guidance on the design specifications for constructing and maintaining a cover system.
II
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10.3 Cost Effectiveness
,.
»'
Based on expected performance, the selected remedy has been determined to be cost-
effective because it would provide overall effectiveness proportional to its costs when
compared agciinst the other alternatives.
"
10.4 Use of Permanent Solutions and Alternative Treatment
Technologies to the Maximum Extent Practicable
The selected remedy utilizes permanent solutions to the maximum exten~ practicable
for this site. The NCP prefers a permanent solution whenever possible._, Because this site has
a large volume of low concentrations of hazardous substances that can be reliably controlled
in place, the alternative focuses on maintenance of the existing cover, monitoring, and
institutional control of Pad A. The selected remedy provides protection by minimizing the
risk of potential contaminant migration to groundwater and by maintaining the inaccessibility
of the Pad A waste materials. Based on evaluation of the CERCLA remedial alternative'
criteria, and in particular the five balancing criteria, limited action will provide the best
solution in terms of long- and short-term effectiveness, cost, and implementability.
10.5 Preference for Treatment as a Principal Element
Because the Pad A investigation and risk assessment indicated that the cover would
reliably control Pad A wastes in place, this remedy did not consider treatment as a principal
element of the remedy.
11. DOCUMENTATION OF SIGNIFICANT CHANGES
Following the Pad A public meetings, additional soil, and soil moisture monitoring
data associated with Pad A became available to the agencies. This information has been
evaluated by the agencies and has been determined to have no impact on 'the remedial
alternatives discussed in the Pad A Proposed Plan' nor on theremedyselected'in the ROD;' ,
Because the data were not previously available for public review and comment, the results
from the sampling activities are being provided in the interest of completeness of the RI/FS.
"J.
In May 1992, 38 soil samples were taken from various locations on the Pad A soil
cover. Radionuclides detected in several of the samples included Am-241, detected in nine
samples with concentrations ranging from 0.78 to 6.66 pCilg, Cs-137 detected in five samples
with concentrations ranging from 0.06 to 0.1 pCilg, and Co-60 detected in only one sample at
a concentration of 0.14 pCi/g. The measured concentrations are consistent with
concentrations detected in past environmental monitoring/sampling activities conducted at Pad
A and other areas. of the RWMC and were determined to warrant no further consideration.
....
The Pad A overburden soil inorganic results were screened against INEL background
surface soil concentrations established in 1989. Only three inorganic contaminants, beryllium,
mercury and manganese, were present in some of the samples above the INEL background
levels. Beryllium was detected in one sample at a concentration of 84.6 mglkg above the
backgrou~d concentration of 2 mglkg. Mercury was detected in two samples at a '
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concentration of 0.11 mglkg and 0.75 mglkg above the background concentration of
0.06 mglkg. Manganese was detected in five samples at concentrations from 629 to 869
mglkg. The background concentration for manganese is 636 mglkg. All other metals were
not present above INEL background levels at the 95% confidence limit. Based on the limited
number of sample results above the INEL background levels, the measured concentrations
were determined to warrant no further consideration.
,
..
VOCs were detected positively in only two of the 38 samples. These two sample
results indicate a potential single isolated VOC source within Pad A. The amount of VQCs
posed by these isolated sample results is considered to be very small and, as such, would
have no impact on the previous decisions. Additionally, the planned institutional controls to
be implemented by this ROD will adequately prevent any exposure to the VOCs.
In addition to these soil samples, one set of soil moisture samples was obtained in
June 1986 from two wells located at the south end of Pad A at a depth of 4.37 m (14 ft 4 in.)
and 2.64 m (8 ft 8 in.). The soil moisture samples were analyzed for nitrates and showed
concentrations of 13 and 48 mglkg. As with the overburden sampling, the concentrations
suggested by the samples are adequately bounded by the Pad A BRA and deemed to have no
impact on previously reported results.
The cost estimates in the ROD reflect contingency costs associated with each
alternative. These contingency costs were not discussed in the Proposed Plan aI)d did not
measurably affect the evaluation of alternatives.
iO
...
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..
-I
APPENDIX A
RESPONSIVENESS SUMMARY
-I'!.
..
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RESPONSIVENESS SUMMARY
.-
Overview
.J
Operable Unit (OU) 7-12, Pad A, is the third OU to be addressed.within Waste
Area Group (WAG) 7, the Radioactive Waste Management Complex (RWMC) at the
Idaho National Engineering Laboratory (INEL). A Proposed Plan was released July 19,
1993, with a public comment period from July 28 to August 26, 1993. The Proposed Plan
recommended that limited action, focusing on maintenance and upkeep of the existing
soil cover and monitoring to ensure the effectiveness of the existing- cover and the
protection of groundwater, be taken at Pad A This Responsiveness Summary recaps
and responds to the comments received during the comment period. Generally, the
comments reflected a broad range of views, from strong support for. the selected
alternative to strong opposition to leaving the wastes in place.
Background on Community Involvement
To announce the beginning of the Pad A investigation, public informational
meetings were held in December 1992 in Idaho Falls, Twin Falls, Boise, and Moscow.
The meetings were to explain the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) process. These informational meetings
were announced via a fact sheet conveyed through a "Dear Citizen" letter mailed on
November 19, 1991, to a mailing list of 5,600 individuals in the general public and 11,700
INEL employees. On November 20, 1991, the U.S. Department of Energy, Idaho
Operations Office (DOE-ID) issued a news release to more than 40 newspaper, radio,
and television media contacts. Display ads announcing the 30-day public comment
period on Pad A appeared between November 22 and November 27, 1991 in eight major
Idaho newspapers: the Post Register in Idaho Falls, the Idaho State Journal in Pocatello,
the South Idaho Press in Burley, the Times News in Twin Falls, the Idaho Statesman in
Boise, the Idaho Press Tribune in Nampa; .the. Lewiston. Meming Tribune-.in .Lewiston, .and
the Idahonian in Moscow. Personal telephone calls were made to key individuals,
environmental groups, and organizations from INEL field offices in Pocatello, Twin Falls,
and Boise. Calls were also made to community leaders in Idaho Falls and Moscow by
the Community Relations Plan Coordinator.
.",
When the investigation was complete, a Notice of Availability for the Pad A
Proposed Plan was published between July 15 and July 20, 1993, in the Post Register
(Idaho Falls), the Idaho State Journal (Pocatello), the SOUth Idaho Press (Burley), the
Tunes News (Twin Falls), the Idaho Statesman (Boise), the Lewiston Morning Tribune
(Lewiston),.and The Daily News (Moscow). A second advertisement was placed in the
same newspapers several days before each open house or meeting to remind citizens of
the opportunity to attend the meeting and provide oral or written comments. Radio
stations in Idaho Falls, Blackfoot, Pocatello, Burley, and Twin Falls ran advertisements
during the three days before the open houses in Pocatello and Twin Falls.
..
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The Proposed Plan for the remedial action of Pad A was mailed July 19, 1993, to
6,600 individuals on the INEL mailing list. Copies of the Proposed Plan and the entire
Administrative Record are available to the public in eight regional INEL information
repositories: the INEL Technical Library in Idaho Falls; city libraries in Idaho Falls,
Pocatello, Twin Falls, Boise, and Moscow; the Idaho State Library in Boise; and the
Shoshone Bannock Library in Fort Hall. The original documents comprising the
Administrative Record are located at the INEL Technical Library; copies from the
originals are present in the seven other bbraries. These copies were placed in the
information repository sections or at the reference desk in each of these libraries.
"
.
The public comment period on the Proposed Plan for Pad A was held from
July 28 to August 26, 1993. No requests for extensions were made. On August 10, 1993,
representatives from DOE-ID, the Environmental Protection Agency (EPA) Region 10,
and the State of Idaho Department of Health and Welfare (IDHW) conducted a
technical briefing via telt;conference with members of the Environmental Defense
Institute and the League of Women Voters of Moscow. Open houses were held August
11 and 12, 1993, in Pocatello and Twin Falls, respectively; representatives from DOE-ID
and IDHW attended the events to discuss the project and answer questions. Public
meetings were held August 17, 18, and 19, in Idaho Falls, Boise, and Moscow,
respectively at which over 40 people attended. Representatives from DOE-ID, EP A
Region 10, and IDHW were present at the public meetings to discuss the project, answer
questions, and receive public comment. Each public meeting was recorded by a court
reporter.
This Responsiveness Summary has been prepared as part of the Record of
Decision (ROD). All oral comments, as given at the public meetings, and all written
comments, as submitted, are repeated verbatim in the Administrative Record for the
ROD. Twelve people submitted written comments on the Pad A proposal and ten
others gave oral comments at the public meetings. No oral comments were received at
the open houses. In order to respond to each issue raised in the comments, DOE
further divided the comments into 106 individual comments. These comments are
annotated to indicate which response in the Responsiveness Summary addresses each
comment. It should be noted that the Responsiveness Summary groups similar
comments tog~ther, summarizes them, and provides a single response for each comment
group. The ROD presents the limited action a1ternative for the Pad A OU at the INEL,
selected in accordance with CERCLA, as amended by the Superfund Amendments and
Reauthorization Act (SARA) and, to the extent practicable, the Na~ional Oil and
Hazardous Substances Pollution Contingency Plan (NCP). The decision for this OU is
based on information in the Administrative Record.
"
L
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Summary of Comments Received During Public Comment Period
.,
~
Comments and questions raised during the public comment period on the Pad A
Proposed Plan are summarized briefly below. Many of the questions were ~nswered at
the public meetings as reflected in the transcripts in the Administrative Record file. An
informal open house was held one hour prior to each of the scheduled public meetings to
allow the public to discuss the proposed action at Pad A with representatives of IDHW,
EP A, and DOE. The public meetings were further divided into an informal question and
answer session and a formal public comment session. This meeting format was identified
in published announcements and the public was informed at the begIrining of each public
meeting that the meeting would be divided into two parts-an informal question and
answer session, where comments and questions would not be formally recorded by a
court reporter and would be immediately responded to by a panel of agency
representatives, followed by a formal comment session which would be recorded by a
court reporter. The public was requested to provide their formal comments on. the
Proposed Plan either during the formal comment session of the meeting or in writing
prior to the close of the public comment period. This Responsiveness Summary
responds to those public comments that were recorded by the court reporter or that were
submitted in writing prior to the close of the public comment period.
Comments and questions On a variety of subjects not specific to the Pad A
Proposed Plan were recorded including planning and future use, historical issues,
procedures' and policies, health and safety, availability of information, DOE's
responsibilities, arid technology development. Responses to those comments are not
included in this Responsiveness Summary, however, additional information on these
unrelated topics can be obtained from the INEL Public Affairs Office in Idaho Falls; the
local INEL offices in Pocatello, Twin Falls, and Boise; or the Environmental Restoration
Information Office in Moscow. Comments and questions regarding. community
participation in general were referred to- the- INELCommunity.Relations .Coordinator .
and will be addressed during updates to the Community Relations Plan. Comments and
questions on Pad A submitted during the entire comment period are answered below.
History and Design of Pad A
1.
Comment: One comrnenter wanted clarification about when Pad A was first
commissioned. (W7-6)
;'I-
Response: Pad A was constructed in September 1972. Wastes were placed on
Pad .A.b.eginning in September 1972.
2
Comment: Several commenters asked about the life expectancy of the 55-gal
drums, the polyethylene liners, and the asphalt pad. One commenter wanted to
know how long the drums and liners willlast. Another commenter remarked that
AI
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because the drums have a 20-year life expectancy they must be well past their
"safe" expected usefulness. Two commenters wanted to know whether wastes
were leaking through the liners or from the drums. Final1y, a commenter wanted
to know more about the design of the pad itself and whether the pad or
something under the pad would prevent the wastes from leaching or seeping into
the ground. (W7-5, WID-I, WID-2, WID-3)
-
..
Response: The life expectancy of the drums, liners and asphalt pad beneath the
wastes is not known. The wastes disposed on Pad A contained no liquids and
were in solid form when disposed. However, for purposes of evaluating current
and future risk to human health and the environment, the quantity of waste
contained in the boxes was assumed to be free to migrate immediately (i.e., the
boxes and associated liners were not considered a barrier to movement of the
waste) and the quantity of the waste in the drums was assumed to be free to
migrate in 100 years (i.e., the drums and associated liners were assumed to total1y
fail in 100 years). In addition, the asphalt pad was not considered a barrier to
movement of the solid wastes.
The most likely transport mechanism at Pad A would be water in the form of
precipitation (rain or snow) that permeated the overlying soil cover and moved
through the wastes. The amount of water that actually permeates the Pad A
cover is relatively limited due to the arid environment at the INEL (e.g.,
infiltration rates measured in undisturbed areas surrounding the RWMC range
from 0.8 to 1.1 cmlyr) as well as the fact that the sloped sides of the existing cover
promote surface water runoff, thereby further reducing infiltration.
Pad A was constructed by placing 5.1 to 7.5 cm (2 to 3 in.) of asphalt over
approximately 7.5 cm (3 in.) of gravel base. For modeling purposes, this type of
pad is assumed to be permeable or to have cracked and could allow contaminants
to migrate to the subsurface area beneath the pad. The selected remedy must
therefore minimize infiltration through the cover and potential1y through the pad.
Monitoring and institutional controls are also part of the selected remedy and will
serve to ensure the selected remedy will be protective of human health and the
environment.
3.
Comment: Three commenters noted that DOE's documents and iBustrations
demonstrated that Pad A was built for monitored retrievable sto~age. Because the
drums and boxes were obviously not meant for long-term storage, it was difficult
to believe that Pad A was engineered as a long-term solution. The wastes were
probably originally put on an asphaJt pad due to concerns about the contents.
One commenter wanted to know how DOE original1y planned to sort and dean
up the wastes on Pad A. (W7-3, W7-9, T5-1, TID-5)
~
~
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.,
Response: Based on reviews of historical reports and interviews with personnel
involved in the design and construction of Pad A, the pad was designed as a
permanent, rather than a temporary, disposal site. Due to basalt outcroppings
near the surface of the north-central portion of the SDA (the current location of
Pad A) and a desire to maximize radioactive waste disposal within the boundaries
of the SDA, a decision was made not to remove the basalt by blasting (and
thereby creating another disposal pit) but, rather, level the area and pour an
asphalt pad upon which the waste would be placed and then covered with soil.
,;
The maintenance of the existing cover, monitoring of the wasJes, and continued
use of institutional controls in the selected alternative will ensure long-term
protectiveness of human health and the environment.
4.
Comment: Two commenters questioned the accuracy and reliability of the
characterization of the wastes in Pad A, remarking that DOE used unverified
values from the shippers of the waste rather than performing its own
characterization. (W5-4, T10-6)
Response: Characterization of the types and' concentrations of the wastes on Pad
A was based on shipping records from the waste generators (e.g., Rocky Flats
Plant) that shipped waste to Pad A as well as the INEL's disposal records. These
records were supplemented with process information obtained from the operating
facilities that produced the wastes and interviews with personnej from those
. facilities. Although sampling is often useful in characterizing a site, it was not
considered practical or feasible in the case of Pad A because of the heterogeneity
of the waste. In addition, characterizing a heterogenous site such as Pad A could
result in information that is less reliable than the process knowledge available on
the wastes. The characterization of the wastes on Pad A did include the results of
the analyses performed on the contents of the drum of salts retrieved in 1989,
which indicated that the nitrated sa}ts..in.thedrum-closely- matched ,the.... .
contamination types and concentrations listed in DOE's records. Thus, historical
records, process knowledge, and limited characterization information were used to
confirm the information and assumptions used in the Pad A investigation. The
agencies believe that the information they have obtained adequately characterizes
the wastes on Pad A for purposes of this action.
5.
Comment: One commenter wanted to know whether an audit had been done,
then suggested that audits must be done to ensure that the present materials on
Pad A were properly stored and maintained. (Wll-4)
~
~
Response: The agencies share the commentor's concern with proper storage and
maintenance of Pad A wastes. Audits, as the term is believed to be used here,
were performed in 1979 and again in 1989 when the containers were visually
inspected to determine their condition. In addition to these inspections,
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environmental monitoring at Pad A has been conducted since the pad was closed
in order to provide an early indication of a gross release of materials from the
pad. The selected alternative will provide protectiveness of human health and the
environment through maintenance of the cover and monitoring of the wastes to
provide early indication of potential releases.
.
...
Risk Asse~ment
6.
Comment: Several commenters noted that DOE's studies failed to address the
known long-term geologic and hydrogeologic threats at the INEL They indicated
that it was unconscionable and unacceptable for DOE not to analyze the risks to
the groundwater or the air in its environmental assessment. For instance,
catastrophic events could change the course of the Big Lost River so that it flowed
into the complex, potentially releasing wastes to the environment. Flooding from
rapid snowmelt and failure of the Mackay Dam were also of concern. Another
commenter stated that the risks associated with a failure of Mackay Dam were
presented in the Waste Management Operations Environmental Impact
Statement. Wastes disposed of at the RWMC, such as those on Pad A, could be
released to the environment during a catastrophic event. One commenter
disagreed, noting that seismic activity resulting in lava flows at the RWMC was as
likely to permanently bury the wastes providing an effective seal against release to
the environment. (W5-5, Wl1-2, Tl-9, T1-1O, Tl-12, Tl-14, Tl-15, T1-1.6, T2-11,
T4-4)
Response: The possible effects to Pad A from the occurrence of a catastrophic
event were not quantitatively evaluated because of the large uncertainties these
events the impacts of which may be positive or negative. The evaluation period
was set at 1,000 years because uncertainties associated with the modeling
approach become unreasonably large beyond this time period.
Impacts from increased infilitration rates due to flooding were addressed in the
sensitivity analysis (Appendix H) of the Remedial Investigation report. The
analysis indicated that flooding events would have a negligible effect on increasing
the average nitrate concentration levels in the aquifer (i.e., by a factor of 2 or 3).
Becaus-e the wastes on Pad A are above ground level at the RWMC, it is unlikely
that increased infilitration rates wi]] strongly affect the transport of the Pad A
waste near the surface. The analysis indicated that, although waters could mig;ate
into the subsurface and increase the transport velocity of wastes that have leached
into the unsaturated zone, the flooding events would have minimal impact on the
outcome of the fate and transport modeling (i.e., the predicted average
concentration levels of contaminants would not significantly change the results of
the risk assessment).
"
~
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7.
Comment One commenter wanted to know whether snow is removed from the
RWMC. (T1-17)
.,
~
Response: Snow is removed from the roads, parking lots, and other areas which
require access.
8.
Comment One commenter questioned what would happen if an animal burrowed
into Pad A Could the Pad A wastes seep out? (W10-4)
Response: This scenario (i.e., burrowing animals) was evaluated in the baseline
risk assessment, performed as part of the Pad A Remedial IDvestigationlFeasibility
Study (RI/FS) and was not considered to pose an unacceptable health risk from
this exposure mechanism. The wastes at Pad ~ which are solid wastes, not
liquids, consist primarily of nitrate salts, depleted uranium waste, sewer sludge,
inorganic salts, dirt, concrete, and other miscellaneous materials buried in plywood
boxes or 55-gal drums. Monitoring has been conducted to detect any contaminant
migration from Pad A since its closure in 1978. Contaminants attnDutable to
Pad A have not been detected in the air, soil, or water samples taken on or near
Pad A Potential routes of migration for Pad A contaminants are direct exposure
to the wastes due to erosion of the cover and infiltration of precipitation through
the wastes causing contaminants to move to groundwater. As discussed in
Section 5 of the RIIFS, burrowing animals ,may be able to reach the Pad A wastes,
and the potential exists for them to bring wastes to the surface. The ,results of the
ecological risk assessment indicate that burrowing activity, as we]] as other
transport mechanisms, are not expected to have significant effects on the local
ecosystem or on human health. Because institutional controls such as access and
land use restrictions are included in the selected alternative, the likelihood of
direct human exposure to the contaminants through this transport mechanism is
extremely small. Further, because inspections and monitoring of the site, and
repair and maintenance of the cover willhbe. conducted as. part. of the selected" . "
alternative, evidence of burroWing animals at the site will be detected and
corrective measures will be taken to prevent wastes from migrating due to
burrowing activities.
9.
Comment: One commenter wanted to know what data DOE possesses that allows
a quantitative determination of risk to 2 parts in 10-13 (see Table 1 on page 7 of
the Proposed Plan). The comment went on to note that if DOE has this accuracy,
then the number of significant digits in the rest of the carcinogenic risk
information is wrong. If DOE cannot quantify risk below 10~ or 10.', it should
pres~nt .the results to reflect this. (W3-2) ,
,~
..
Response: The Pad A baseline risk assessment, performed as part of the RIIFS,
calculated carcinogenic risk values based on the fate and transport modeling
results. The resulting risk values are derived by multiplying the cancer slope
-------
11.
factors for individual chemicals (provided by EP A) by the estimated daily intake
(derived from the modeling). This approach represents the standard EP A derived
risk assessment methodology. A quantitative risk estimate of 2 x 10-13 does not
imply that this degree of accuracy is implicit in all cancer risk estimates. Rather,
the estimated lifetime excess cancer risk estimate indicates that the expected risk
is considerably less than the EP A's risk range of 10-4 to 10-6.
,
~
10.
Comment: One commenter pointed out that the Proposed Plan states that nitrate
concentrations in groundwater at the Pad A boundary win reach 112 mgIL.
Previous text indicates this will occur in about 2228. The values are qualified by
pointing to conservative estimates in modeling. What is the cumulative
quantitative effect of the modeling? Associated with this, what is the accuracy and
precision of the model? Can it be quantitatively demonstrated that the presented
results are unreasonable? If so, why were they presented? If not, then these
values should drive the risk assessment, resulting in a risk to infants from exposure
to nitrates that is clearly unacceptable. (W3-1)
Response: Based on the assumptions used in the fate and transport modeling for
the baseline risk assessment, MCLs for nitrates in groundwater were calculated to
be exceeded at the WAG 7 boundary; however, groundwater concentrations based
on actual infiltration rates are expected to be lower. For example, the infiltration
rate used in the modeling was 5 cm/yr. Using actual infiltration rates of 0.8 to 1.1
cm/yr, MCLs at the WAG 7 boundary are not expected to be exceeded. The
assumptions used in the model were as realistic as possible but were skewed
towards the conservative to ensure that potential risks were not underestimated.
The uncertainties associated with the assumptions can be found in Section 7.1.4 of
the RIIFS. The impact of the conservative modeling results in a tendency to
overestimate potential concentrations of contaminants that could reach the
aquifer.
Comment: Several comments were directed toward the timeframe used by DOE
for their analysis. One commenter observed that it was farcical for DOE to limit
-'
their analysis to 1,000 years when the contaminants win be dangerous for much
longer !han that. The commenter went on to remark that the only reason DOE
did not analyze risk beyond the 1,000-year window was because their models were
not sufficiently accurate to predict the fate of the wastes beyond that time.
However, another commenter disagreed with this assessment, reasoning that for
wastes such as those on Pad A, 1,000 years was too long a period of time for risk
assessment purposes. (W5-3, T1-8, T2-9)
..
Response: The evaluation period was set at 1,000 years because uncertainties
associated with the modeling approach become unreasonably large beyond this
time period. Due to the large uncertainties associated with episodic events (i.e.,
ice ages, major earthquakes, meteor impacts, and volcanism), these events were
..
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r
not modeled. Because wastes will remain on-site, the Pad A remedy will be.
reevaluated in two years and every five years thereafter to ensure continued
protectiveness. In the event that any fundamental assumptions made in the Pad A
investigation change (e.g., loss of institutional control due to loss of DOE control
or future land use changes) the need for additional action would then be
considered.
'-J,
12.
Comment: A written comment noted that information provided at the Idaho Falls
public meeting addressed the radiotoxicity of a few, but not all, contaminants in
the Pad A wastes and did not address chemical toxicity at all~ Another
commenter questioned what nuclear debris has a 10-year half-life and if it referred
to plutonium. (W5-1, W7-4)
Response: It is true that during the Idaho Falls public meeting, the radiotoxicity
of all the contaminants at Pad A was not addressed. However, the BRA
contained in the RIIFS evaluated all the contaminants, both radiological and
chemical. They were evaluated on exposure mechanisms, concentration levels,
relative toxicity, and the carcinogenic risks posed to human health and the
environment. Specifically, a detailed discussion of contaminant toxicity is
contained in Section 6.1.2 of the RIIFS and Section 6.1.3 of the ROD. The RIIFS
is located in the administrative record under file number AR3.10.
. Mo"eling performed in the BRA indicated that radionuc1ides (with the e~ception .
of potassium-40) would not reach the aquifer within 1,000 years. The modeling
showed potassium-40 reaching the aquifer within the 1,000 year timeframe but not
at sufficient concentrations to pose an unacceptable risk. Inorganic compounds
were also evaluated in the risk assessment and only sodium nitrate and potassium
nitrate were shown to present any potential risk to the human health and the
environment.
The radionuclide isotopes found at Pad A have half-lives ranging from a few
months to several thousand years. A half-life of 10 years does not necessarily
refer to plutonium. This information can be found in the Remedial Investigation
report (Section 4).
13.
Comment: One commenter noted that a post-control period infant is not an
industrial receptor (see Table 1 on page 7 of the Proposed Plan). (W3-3)
,.,.,
Response: The term "post-control period" refers to that timeframe in the future
when..the INEL may be used for residential or industrial development. The
potential for adverse effects to small children or infants is associated with the
assumed future residential development. The Proposed Plan incorrectly identified
infants as industrial receptors for the post-control period.
...
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14.
Comment: Several commenters indicated that it does not do much good to assess
the risk from just Pad A as it represents a very small fraction of the wastes at the
R WMC; the tOtal composite risk from all the WAGs must be studied. If the
INEL is available for unrestricted use (see Item 3 on Page 6 of the Proposed
Plan), it is an unrealistic scenario to only evaluate risk for a single unit. Risk from
all the units may be additive. If risk is only addressed unit by unit through the
INEL, an actual risk may not be recognized. (Wl-2, W3-4, W5-1.1)
~
oJ
Response: The agencies agree with the commenters. The cumulative risks from
all of the pits and trenches located at the RWMC (WAG 7) will be evaluated in
the TRU Pits and Trenches OU 7-13 RIIFS. Cumulative risks from inactive waste
sites throughout the entire RWMC will be evaluated in the Comprehensive WAG
7 RIIFS. All of the risks from all of the WAGs located at the INEL will be
evaluated in the Comprehensive WAG 10 (sitewide) RIIFS. This approach is
consistent with the NCP. One of the stated purposes of the NCP [~ 300.3(b)] is to
provide for efficient, coordinated, and effective response to releases of hazardous
substances. Section 300.430(a) of the NCP states that complex sites should
genera11y be addressed in OUs when early actions are necessary or appropriate to
achieve significant risk reduction quickly, when phased analysis and response is
necessary or appropriate given the size or complexity of the site, or to expedite
completion of the total site cleanup. The agencies recognized that cumulative
assessments should be done and have scheduled comprehensive investigations on
both the individual WAG and the INEL-wide levels. At the same time, the
agencies acknowledged that cumulative risks could not be evaluated until adequate
information concerning each individual site is co11ected. The FF NCO Action Plan
includes the schedules for addressing each of the OUs and WAGs. This approach
was presented to the public for review and comment during the comment period
on the FF NCO before it was signed by the three agencies.
15.
Comment: One commenter wanted to know whether the time of peak nitrate
concentration at the INEL boundary and the RWMC boundary coincide with the
peak under Pad A. In addition, the commenter wanted to know what the ambient
conditions in the Snake River Plain Aquifer wi11 be, considering the number of
potential contaminant contributors. (W3-5)
Response: Peak nitrate concentrations in groundwater beneath Pad A will occur
before peak values are reached at either of the other boundaries. Based on
conservative fate and transport modeling, ambient groundwater conditions beneath
Pad A could potentially be affected by the more soluble inorganic contaminants
(e.g., nitrates). The impacts to groundwater conditions from these contaminants
are dependent upon many variables (e.g., distance from source, infiltration rates).
Ambient conditions are not expected to be affected by Pad A contaminants if the
selected remedy is implemented.
'"
..
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16.
Comment: One commenter stated that actions at Pad A must comply with the
Nuclear Waste Policy Act and Nuclear Regulatory Commission disposal criteria.
(T10-3)
"'
j
Response: The Nuclear Waste Policy Act of 1982, as amended, esta~lishes
requirements for selecting and constructing a geologic repository for disposal of
high-level wastes and spent nuclear fuel and for the interim storage of such wastes
pending development of the repository. Because Pad A does not contain either
high-level waste or spent nuclear fuel, this law does not apply to Pad A wastes,
nor is it relevant and appropriate in the circumstances of the Pad A proposed
action. -
Under the Atomic Energy Act, Congress divided the nuclear ~dustry into tWo
separate entities, each with separate responsibilities. The Nuclear Regulatory
Commission (NRC) regulates the commercial nuclear industry (i.e., power
generation). The DOE is responsible for researching and planning the country's
energy supply and delivery, including nuclear power, developing and
manufacturing nuclear weapons, and managing high-level and low-level radioactive
waste produced from these activities.
Thus, there are only limited situations when DOE operations fall under the
jurisdiction of the NRC. Except for these very limited situations, NRC standards
do not legany apply to DOE activities. This is why NRC regUlations are not listed
as ARARs in Pad A However, NRC standards are reflected in many of the
internal DOE orders, which are mandatory requirements for all DOE facilities and
activities. DOE Order 5820.2A is included in the Pad A ROD as a to-be-
considered (TBC) guidance. This order contains the substantive requirements
included in NRC regulations.
-"I
In the case of Pad A, remedy se1ectiQn.is.based onCERCLA, as.amended.by ..
SARA, and the regulations contained in the NCP. AJI remedies must ineet the'
threshold criteria established in the NCP: protection of human health and the
environment and compliance with ARARs. As identified in the ROD, ARARs at
Pad A include compliance with the relevant and appropriate substantive
requirements of the Idaho Hazardous Waste Management Act. In addition,
various EP A guidance documents and tWo DOE Orders (5820.2A, Radioactive
Waste Management and 5400.5, Radiation Protection of the Public and the
Environment) are cited as TBC guidance for purposes of implementing the Pad A
selected remedy. The agencies agree that these standards will be the criteria at
PadA. .
..
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Proposed Plan and Public Involvement
..
17.
Comment: One commenter asked whether public hearings or comment periods
were held before Pad A was employed in 1972. Another commenter noted that
there was a need for substantive public participation in the planning process;
substantive public participation would result in a reevaluation and readjustment of
the agencies' priorities. (W7-2, T10-2)
'r
Response: Based on reviews of historical documents, there is no evidence that
indicates public hearings were held prior to "employing" Pad A During the Cold
War, DOE conducted high-technology research and produced nuclear weapons.
This needed to be done quickly while also maintaining national security which, in
most instances, precluded public involvement. Growing concern among the public
about problems with the environment resulted in the enactment of several
programs to ensure that communities are informed about and involved in
hazardous waste issues. These include the National Environmental Policy Act of
1969 (NEP A); CERCLA, as amended by the 1986 SARA; and the Resource
Conservation and Recovery Act (RCRA) of 1976; an as subsequently amended.
The agencies consider public participation to be a critical element of
environmental restoration activities as well as other waste management planning
activities at the INEL. Several public participation opportunities are available to
the public; information about these opportunities is included in the lNEL
Community Relations Plan or can be obtained from the INEL Community
Relations Coordinator at (800) 708-2680 or (208) 526-6864.
18.
Comment: One commenter indicated that DOE should provide an explanation of
the white tent-like structure on Pad A pictured on the cover of the Proposed Plan.
(W8-3)
Response: The white tent-like structure on Pad A is called a ''yurt.'' It was placed
on Pad A in 1989 to provide a controlled environment, and prevent releases of
contaminants to the atmosphere, during the drum retrieval effort conducted in
1989. Although the project was safely completed and closed-out, the yurt was
never removed.
19.
CoII:lli1ent: Two commenters commended DOE on the contents and information
provided in the Proposed Plan. One commenter indicated approval of DOE's
approach, noting that DOE indicated when the information supplied represented
deductions rather than facts. (W2-1, W8-4)
~
Response: Comment noted.
..
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20.
Comment Public hearings should involve the decision-makers who set the .
criteria, methodology, values, and made judgments leading to the alternatives that
are being considered. The items on which the study is based have not been
presented. Instead, the public is given a glossy, narrow definition of the problem
- public relations rather than a review of the actual problem. If th~ public was
given the opportunity to review the larger, inherent problems; more reasonable,
efficient, and long-term solutions could be attained. (T7-1)
"
~
Response: The agencies agree that public involvement in the CERCLA process is
critical to ensuring successful remediation of INEL waste sites. The public
meetings conducted in Moscow, Boise, and Idaho Falls were-attended by Mr.
Dean Nygard, Federal Facilities Manager for the Idaho Division of Environmental
Quality; Ms. Mary Jane Nearman, U.S. Environmental Prote~tion Agency Region
10, RWMC Waste Area Group Manager; and Mr. Greg Hula, U.S. Department of
Energy Idaho Operations Office, Pad A Project Manager. These individuals were
present at the meetings to provide detailed information concerning this action,
answer questions, and take formal comments. These same individuals reviewed
and determined the criteria, methodology, and values that needed to be reflected
in the Pad A remedial action, based on legal requirements and agency policies and
guidance.
. A series of opportunities for public information and participation in the remedial
investigation and decision process for Pad A were provided over the course of
21 months beginning November 1991 and continuing through August 1993. For
the public, the activities ranged from receiving a fact sheet, INEL Reponer articles
and updates, and a Proposed Plan, to having a telephone briefing, four public
scoping meetings, three public meetings, and two open houses to offer verbal or
written comments during two separate 3D-day public comment periods. The
proposed plan is intended to be a summary of the detailed RIIFS that was
conducted. It references the entire. administrative..record.Jor.membersof the. . . ..
public who are interested in reviewing more detailed information on the proposed
action.
"
The Pad A RIIFS process followed the process required under CERCLA, as
amended by SARA, and the NCP. All three agencies have been involved in the
scoping, implementation, and decision process for this investigation. Further
questions regarding specific technical issues or the public participation process can
be directed to the INEL Community Relations Coordinator at (800) 708-2680 or
(208) 526-6864.
21.
Comment Several commenters remarked on procedural aspects of the public
meetings. Some commenters felt that a specific time should be allotted to each
individual giving public testimony. However~ another commenter noted that the
purpose of the meeting was to gain public comment and that it was unfair to
~
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arbitrarily limit time allowed for testimony. One commenter questioned the level
of information available at the open houses and indicated his participation in the
public meeting was a result of insufficient information at the open house. (W9-1,
Tl-l, TI-6, TI-18, Tl-19, T2-1, T3-1, T4-1)
,.
..
Response: The public meetings for Pad A provided two opportunities for citizens
to become involved: an informal question and answer period, and formal
comment period. The informal question and answer period was set up to allow
the public to ask questions or to seek clarification on information presented prior
to or at the meeting, or in lieu of making formal comment. Generally no time
restrictions are placed on either activity to ensure that citizens have sufficient
opportunity to have their questions answered and comments and concerns noted;
however, at times it may be necessary to limit the time allowed for each formal
comment to allow all citizens an opportunity to comment. In addition to providing
an opportunity for formal comment at public meetings, the agencies also provided
other means by which the public could enter their comments. Oral comments
could be entered on a tape recorder provided at both the open houses and the
public meetings. The INEL Community Relations telephone was equipped with
recording equipment for oral comments. Finally, written comments could be
submitted either on the individual's own stationery or on the self-addressed,
postage-paid comment forms provided in the Proposed Plan and made available at
all activities.
A series of opportunities for public information and participation in the remedial
investigation and decision process for Pad A were provided over the course of
21 months beginning November 1991 and continuing through August 1993. For
the public, the activities ranged from receiving a fact sheet, INEL Reporter articles
and updates, and a Proposed Plan, to having a telephone briefing, four public
scoping meetings, three public meetings, and two open houses to offer verbal or
written comments during two separate 3D-day public comment periods.
22.
Comment: One commenter asked to see other citizens' comments. (W2-4)
Response: AIl oral comments, as given at the public meetings, and all written
comments, as submitted, are repeated verbatim in the Administrative Record for
OU 7-12. The comments are annotated to indicate which response in the
Responsiveness Su~nmary addressed each comment. It should be noted that the
Responsiveness Summary groups similar comments together, summarizes them,
and provides a single response for each comment group. The Administrative
Record -also indudes transcripts of the public meetings - including the agencies'
presentation, the question and answer period, and formal comment and testimony.
""
The Administrative Record is available to the public in eight regional INEL
information repositories: the INEL Technical Library in Idaho Falls; city libraries
-------
T
in Idaho Falls, Pocatello, Twin Falls, Boise, and Moscow; the Idaho State Library
in Boise; and the Shoshone Bannock Library in Fort Hall. The original
documents comprising the Administrative Record are located at the INEL
Technica1 Library; copies from the originals are present in the seven other
b"braries. These copies were placed in the information repository se~tions or at
the reference desk in each of these libraries.
"
General Comments on the Proposed Alternatives
23.
Comment One commenter mentioned the importance of pr~venting releases to
the air that could occur through mistakes in handling. The commenter remarked
that workers should not be put at risk through contact with the waste. (T8-3)
Response: The selected alternative on Pad A consists of recontouring, slope
correction, and maintenance and monitoring of the existing Pad A cover. Under
the selected remedy, no wastes would be handled, exhumed, repackaged,
transported, or disturbed in any manner. The low-level wastes at Pad A will
remain buried and undisturbed. Thus, the possibility of a release to the ambient
air, soil, or groundwater via worker mishandling is virtually nonexistent. In
addition, monitoring and inspections will continue to ensure early detection of any
potential releases.
24.
CoJ;DIl1ent Several commenters noted that the cost e~timates for implementation
of the alternatives were outrageous and asked DOE to reexamine the estimates.
One commenter thought the estimate of $45,000/year for monitoring seemed a bit
inflated, given the only potential risk is from a single contaminant, nitrate.
Because nitrates are relatively inexpensive to monitor in groundwater and because
monitoring techniques and instruments are continuaUy improved, the commenter
believed that monitoring costs will actually decrease. However, the commenter
acknowledged that much win -depe-nd-on.the,sampling -strategy/decision.. - (W8-2).
Another commenter questioned why a range was given for the estimate for
Alternative lA while relatively precise costs were given for Alternatives IB and 2.
The commenter wanted more information about the precision of the estimates.
Finally, the commenter noted that the information in the Proposed Plan appeared
to be skewed to influence readers to accept Alternative 2, rather than being
objectively presented with a logical conclusion. (W3-6, W4-2, TI0-7)
""
Response: As required by the NCP,cost estimates provided in the Proposed Plan
are Iough estimates (i.e., -30% to +50%) given for comparison purposes only.
Cost estimates for sampling and monitoring activities will be provided in greater
detail in the Remedial Design phase which foHows the ROD. Costs may appear
high because overhead rates with the management and operations contractors and
general and administrative rates are aU factored into the ultimate cost estimate.
.>01
-------
The cost estimates for the technical portion of the alternatives evaluated are
consistent with the costs associated with similar activities conducted at other
landfills across the country, as discussed in Appendix C of the Feasibility Study,
which formed the basis for the cost estimates associated with the alternatives
evaluated in the FS; however, the cost estimates also include administrative costs
associated with the project, which tend to be higher within the government, and
the DOE system specifically, than in the private sector. The cost estimates
contained in the ROD are based on sampling the groundwater, air, soil and
surface water for a range of contaminants known to be present in Pad A, not
exclusively nitrates.
~
,
Several combinations of different earthen material types were evaluated within the
first subalternative ("Alternative lA") resulting in a range of costs. Every effort
was made to objectively present each alternative so that a rational comparison
could be made, iI)cluding cost comparisons. Table 16 in the ROD presents a cost
comparison of the considered alternative for Pad A.
25.
Comment: Several commenters questioned whether DOE considered all possible
alternatives for remediation of Pad A One commenter questioned whether
alternatives proposed for or implemented at other waste areas at the site were
considered for Pad A One commenter remarked that DOE opted for the
proposed alternatives - to maintain and monitor the existing dirt cover - because
it did not know what else to do. The commenter went on to question the wisdom
of dumping more dirt on what is already a mess. (W7-8)
Several comments were received regarding the feasibility of treating Pad A wastes
to eliminate the radioactive constituents or to reprocess or recycle the wastes for
positive uses. One commenter wondered whether DOE considered processing
and elimination of radioactive materials, while another wanted to know whether
DOE was investing in research to determine whether radionuclides could be
recycled or reused. One commenter noted that DOE should find a positive use
for the radionuc1ides currently being thrown away and in the interim find safe,
long-term storage solutions for its radioactively contaminated wastes. Another
comme~ter wanted to know how much of DOE's budget is being used for
research to find positive uses for its wastes, such as the wastes on Pad A. (Wll-l,
T5-2, T6-1, T8-9)
Response: The results of the remedial investigation and BRA indicate that the
existing cover is a protective barrier for the Pad A contents and that leaving the
Pad A wastes in place does not pose an unacceptable risk to human health and
the environment. In accordance with CERCLA and the FFNCO, if an area does
not pose an unacceptable risk, cleanup alternatives that involve excavation,
treatment, and disposal elsewhere are not typically evaluated. Nevertheless, the
preferred alternative (long-term maintenance of the soil cover, groundwater
"
«-
-------
l'
monitoring, and institutional controls such as restricted access) was selected to
prevent direct contact with the wastes. Maintenance of the cover is being done to
address the uncertainties associated with the risk modeling and to ensure that
Pad A will be a protective unit.
t.
.-
Aside from the Pad A context, DOE continues to research ways to minimize,
reuse, or stabilize/treat its wastes. DOE has budgeted just under $1 billion for
technology development within the DOE complex.
26.
Comment: One commenter asked how the pad will be moni!ored for its structural
integrity if it is buried. (Wll-3) .
Response: The risk assessment, which indicated an acceptabl~ long-term risk to
human health and the environment, assumed that the containers and the asphalt
pad failed and would not act as barriers to contaminant migration (i.e., it was
assumed the Pad A wastes are not in containers and that the waste is placed
directly on native soil.). Therefore, there is no need to monitor or audit the
condition of the asphalt to ensure its continued structural integrity; however,
monitoring for contaminant releases will be conducted as part of the selected
remedy.
27.
Comment: One commenter requested a formal WAG-wide Environmental Impact
Statement (ElS) be completed before any wastes are declared to be permanently
disposed of at the INEL (W5-2)
~
Response: The analyses and processes required by CERCLA and the NCP for
remedy selection invo1ve essentially the same scope, level of detail, and subject
matter that are appropriate under NEP A DOE has issued a policy which
requires integration of NEP A values into the CERCLA decis.ion processes where
practicable. Also, through the. CERCLA..public.comment process, DOE carries
out NEP A public involvement goals and responds to all public comments received
in the res.ponsiveness summaries that are prepared. Consistent with DOE's policy,
relevant NEP A values for a particular CERCLA action are iden~ed and may be
discussed in the CERCLA documentation that is prepared; alternatively,
supplemental information may be prepared to ensure these values are considered.
This approach is needed to achieve the CERCLA statutory mandate for
expeditious and prompt cleanups and to allow flexibility in fQrmulating the
response to be taken at different ODs. DOE reviewed the Pad A proposed action
and concluded that the action qualified for a categorical exclusion (ex) consistent
withJ)QE's published NEP A procedures. Therefore, an EA or ElS is not
considered to be necessary for Pad A NEP A's objective of considering the
environmental impacts associated with the selected ahernative for Pad A was met
primarily through the CERCLA BRA process, which includes an ecological risk
assessment component. This risk assessment concluded that the selected
~
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alternative does not pose an unacceptable risk to the environment. The NEP A
objective of assessing cumulative environmental impacts of all WAG 7 remedial
activities will be met through a WAG-wide risk assessment that will be conducted
as part of a WAG-wide RIIFS, as well as through the INEL Environmental
Restoration and Waste Management (ER& WM) EIS, which is currently being
prepared. A draft of that EIS is expected to be issued for public comment in
FY-94.
..
.
28.
Comment: One commenter noted that, while the next 30 years will bring new
technologies, there was no need to implement interim measures such as adopting
Alternative 2. (W 4-1.1 )
Response: Despite the likelihood that new technologies will be discussed and/or
implemented in the next 30 years, CERCLA still mandates that actions be taken
to assure the protection of human health and the environment from releases of
hazardous substances. Further, periodic reviews of monitoring data, site and land
use conditions will be conducted to verify the assumptions of the BRA. In the
event of changing conditions or if fundamental assumptions are no longer
accurate, the need for additional action, including application of treatment
alternatives, would then be reevaluated.
29.
Comment: Two commenters questioned DOE's preference for a soil cover rather
than a synthetic cover.
One commenter indicated that none of the proposed alternatives will prevent
water from entering the Pad A cover. The Pad A wastes must be contained;
water must be prevented from infiltrating the wastes. The commenter indicated
that the proposed covers should be designed with 100- or 125-mil welded plastics
over a 6 in. clay layer over a layer of clean sand (no rocks). (T8-1)
Another commenter indicated that only Alternative 1, with a synthetic cover,
should be considered based on the negligib1e cost difference betWeen the alterna-
tives and the benefits from implementing that alternative. (W4-1)
Response: The agencies' decision to choose Alternative 2, Limited Action, was
not based solely on a comparison of the pad's cover (i.e., soil/clay v. synthetic).
The three alternatives considered in the Pad A ROD were evaluated bas~d on a
comparison of the nine CERCLA decision criteria. Thus, the Pad A feasibility
study evaluated the following criteria to determine the best course of action at this
site: overaH protection of human health and the environment; compliance with
ARARs; long-term effectiveness and permanence; reduction of toxicity, mobility,
or volume through treatment; implementability; cost; and state acceptance. A
summary of this evaluation is included in the Proposed Plan (pp. 9-12) and the
Section 8 of the ROD. Based on this comparative analysis, the agencies chose
,
"-
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~
Alternative 2 because they determined this a1ternative provided the best balance
of trade-offs. Alternative 2 would provide the best overal1 protection and
compliance with ARARs, ensure risks are reduced, provide adequate protection
for both long- and short-term effectiveness, can be easily implemented, and is cost
effective.
...
30.
Comment: One commenter recommended that DOE successfully complete one
remediation activity before beginning the next. Lessons learned at Pit 9 could
then be used to remediate Pad A wastes. (T8-2)
Response: Lessons learned at Pit 9 are not necessarily appliCable to Pad A
because the results of each site's eva1uation demonstrated a need for different
remedia1 actions. In Pad A, the BRA indicated no unaccepta~le risks were
present assuming prolonged direct contact to the Pad A waste is prevented, and
thus Alternative 2, Limited Action, was chosen. Also, Pit 9 was an interim action
due to the large volumes of oils, solvents and relatively large amounts of
radioactive contaminants. In contrast, Pad A.is a permanent disposal action and
does not contain these types of wastes. Thus, lessons learned at Pit 9 would not
necessarily be used to remediate Pad A waste because the results of the RIIFS
and BRA indicated remediation (i.e., removal, treatment, and disposal) was not
necessary to adequately protect human health and the environment.
31.
Comment: Two commenters indicated that potential environmental problems
should be dealt with now, rather than shifting the burden to future generations or
to other communities. One of the commenters expressed concern that if the
Pad A wastes were not dea1t with now, they may never be dealt with. (T1-7,
Tl0-4)
~
Response: The RIIFS and BRA evaluated both current and future potentia1 risks
from Pad A waste to determine potentia1 environmental problems to both current. .
and future generations. This ana1ysis indicates that conditions at Pad A are not
expected to result in environmental problems to current or future generations.
The INEL, including Pad A, is being evaluated under an FF NCO entered into
between DOE-ID, EPA, and the State of Idaho in order to ensure compliance
with-CERCLA, RCRA and the Idaho Hazardous Waste Management Act
(HWMA). These statutes require that cleanup actions be taken if there is a
release or threat of a release of a contaminant to the environment which exceeds
regulatory or risk-based cleanup standards. The remedial investigation for Pad A
indicated that there is currently no unacceptable risk to human health and the
envi!:9.p.~ent. Therefore, the question remained, could contaminants migrate from
Pad A and present an unacceptable risk to human health and the environment at
some time in the future? The Pad A risk assessment was conducted to answer
this question. The risk assessment using available data, including generator
records, indicated the risk to human health and the environment would be within
jfi
-------
the acceptable risk range as defined by CERCLA assuming prolonged direct
contact to the waste is prevented. It is important to note that the computer
model used conservative assumptions to be on the safe side (e.g., the model
assumed that the Pad A waste materials were not containerized and were disposed
of directly onto the soil as opposed to on an asphaJt pad.)
,
-
The results of the remedial investigation and BRA indicate that the existing cover
is a protective barrier for the Pad A contents and that leaving the Pad A wastes in
place does not pose an unacceptable risk to human heaJth and the environment
assuming institutional controls are maintained to prevent prolonged direct contact
with the waste. In accordance with CERCLA and the FF NCO, if an area does
not pose an unacceptable risk, cleanup alternatives that involve excavation,
treatment, and disposal elsewhere are not typically evaluated. Nevertheless, the
selected alternative (long-term maintenance of the soil cover, groundwater
monitoring, and institutional controls such as restricted access) was selected to
prevent direct contact with the wastes. Maintenance of the cover is being done to
address the uncertainties associated with the risk modeling and to ensure that
Pad A will be a protective unit.
32.
Comment: DOE is expending resources to remediate Pad A while it continues to
bury equally environmentally hazardous wastes at the RWMC. (T10-1)
Response: DOE is not continuing to bury mixed wastes (i.e., wastes that are
radioactive as well as defined as hazardous pursuant to RCRA and HWMA) at
the RWMC and has not disposed of these types of wastes since approximately
1984. Rather, these wastes are currently being stored at the Transuranic Storage
Area (TSA) at the RWMC in accordance with RCRA and HWMA. DOE is
currently preparing documentation to obtain a Part B Permit (i.e., final permit)
which win allow storage of these wastes at the TSA. The wastes currently being
stored at the TSA win be retrieved and eventually transferred to the R WMC
waste storage facility for eventual treatment and/or on- or off-site disposa1. The
only wastes that are currently buried at the Subsurface Disposal Area (SDA) are
low level wastes (i.e., radioactive wastes with a transuranic activity ef less than 10
nCi/g) in the SDA at the RWMC and disposal is conducted in accordance with
low level waste acceptance criteria (WAC).
33.
Comment: One commenter mentioned that nonradioactive contaminants are as
much a concern as the radioactive contaminants since they are toxic and pose a
permanent risk to human health and the environment. (Wll-2)
..
Response: The agencies agree. Risks from nonradioactive hazardous
contaminants (e.g., chlorides and nitrate salts) were evaluated in the BRA and it
was determined that they posed no threat to human health or the environment.
As identified in the ROD, the selected remedy at Pad A win be designed to
6.
-------
~
comply with the relevant and appropriate substantive requirements of the Idaho
HWMA; various EP A guidance documents; and DOE Order 5820.2A, Radioactive
Waste Management. The remedy at Pad A will meet all DOE Order
requirements and the relevant and appropriate RCRA/HWMA requirements
governing the closure of landfills that contain low-level radioactive waste and
nonradioactive hazardous waste.
~
34.
Comments: Several commenters had other general comments on the proposed
alternatives.
-
Because the INEL was never meant to be a permanent repository for radioactive
waste, a permanent home for the wastes should be found and the Pad A wastes
removed and disposed of properly. (WI-I)
Another commenter noted that, because the RWMC requires active management,
it was unsuitable for permanent disposal of wastes. (T1-16)
If elimination cannot be accomplished, then containment is necessary. The
materials on Pad A are too dangerous to risk contamination of groundwater or the
air. Deadly wastes must be contained as long as they pose a hazard to human
health and the environment. (Wll-2, Tl-5)
~
Response: . The INEL, including Pad A, is being evaluated under a FF AlCO
entered into between DOE-ID, EPA, and the State of Idaho in order to ensure
compliance With CERCLA, RCRA and the HWMA. CERCLA and
RCRA/HWMA only require that cleanup actions be taken if there is a release or
threat of a release of a contaminant to the environment which exceeds regulatory
or risk-based cleanup standards. The remedial investigation for Pad A indicated
that contaminants from Pad A do not currently pose unacceptable risks assuming
prolonged direct contact to the waste. is prevented. -- Therefore,. the. question. " .
remaine.d, could contaminants migrate from Pad A and present an unacceptable
risk to human health and the environment at some time in the future? The
Pad A risk assessment was conducted to answer this question, The risk
assessment based on available information, including generator records and using
a computer model, indicated the risk to human health and the environment would
be within the acceptable risk range. It is important to note that the computer.
model used conservative assumptions in order to be on the safe side (e.g., the
model assumed that the Pad A waste materials were not containerized and were
disposed of directly onto the soil as opposed to on an asphalt pad, and greater
than_m:n:mal rainwater infiltration rates were assumed).
-
The results of the remedial investigation and BRA indicate that the existing cover
is a protective barrier for the Pad A contents and that leaving the Pad A wastes in
place does not pose an unacceptable risk to human health and the environment 50
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35.
36.
long as institutional controls are maintained. In accordance with CERCLA and
the FF NCO, if an area does not pose an unacceptable risk, cleanup alternatives
that involve excavation, treatment, and disposal elsewhere are not typically
evaluated. Nevertheless, the selected alternative (long-term maintenance of the
soil cover, groundwater monitoring, and institutional controls such as restricted
access) was selected to prevent direct contact with the wastes. Maintenance of the
cover is being done to address the uncertainties associated with the risk modeling
and to ensure that Pad A will be a protective unit.
..
.
Agree
(Commenter Agreed with Selected Alternative)
Comment: Several commenters indicated their agreement with the Preferred
Alternative selected by DOE. The Preferred Alternative was recognized as
presenting the least risk to workers and the public and being the most cost-
efficient alternative for the established objectives. One commenter noted that the
logic, process, and justifications for the Preferred Alternative were presented well
and made good sense. The commenter went on to indicate that he was glad to
see the State of Idaho was willing to leave low-risk wastes at the RWMC.
Another commenter noted that, as long as there is no real threat to the
environment, DOE should not be wasting resources (i.e., tax dollars) on
precipitous cleanup. (W6-I, W8-I, WI2-1, T2-10, T4-6)
Response: DOE, EP A, and IDHW agree that limited action is the best
alternative based upon the risk assessment, which shows that no unacceptable risk
exists assuming prolonged direct contact with the Pad A waste is prevented.
Monitoring, with independent verification of the data by EP A and IDHW, will
ensure that the selected remedy will be protective of human health and the
environment.
Disagree
(Commenters Disagreed with Selected Alternative)
Comme_Dt: Some commenters stated that the Selected Alternative (containment
in place with monitoring) was not protective enough and that something else was
necessary (i.e., excavation and disposal elsewhere). Specific comments are as
follows:
Several commenters indicated that DOE's proposal not to remove the waste on
Pad A was both unacceptable and irresponsible. Another commenter noted that
all of the alternatives were unacceptable. (WI-I, TI-20, T8-I, T8-4, TI0-4)
Ii.
.
Another commenter wanted to see not only Pad A but the rest of the INEL
cleaned up, questioning when and how something will be done with the wastes
-------
~
y
that have been generated and stored at the INEL and noting that any haste on
DOE's part will be lauded and a pleasant contrast to the usual diversion and
delay. (W7-!)
,
Response: The lNEL, including Pad A, is being evaluated under a FF NCO
entered into between DOE-ID, EP A, and the State of Idaho in order to ensure
compliance with CERCLA, RCRA and the HWMA CERCLA and
RCRA/HWMA only require that cleanup actions be taken if there is a release or
threat of a release of a contaminant to the environment which exceeds regulatory
or risk-based cleanup standards. The remedial investigation for Pad A indicated
that contaminants from Pad A do not currently pose unacceptable risks assuming
prolonged direct contact with the waste is prevented. Therefore, the question
remained, could contaminants migrate from Pad A and present an unacceptable
risk to human health and the environment at some time in the future? The
Pad A risk assessment was conducted to answer this question. The risk
assessment used available data, including generator records, indicated the risk to
human health and the environment would be within the acceptable risk range
assuming prolonged direct contact to the waste is prevented. It is important to
note that the computer model used conservative assumptions in order to be on the
safe side (e.g., the model assumed that the Pad A waste materials were not
containerized and were disposed of directly onto the soil as opposed to on an
asphalt pad, and greater than normal rainwater infiltration rates were assumed).
The results of the remedial investigation and BRA indicate that the existing cover
is a protective barrier for the Pad A contents and that leaving the Pad A wastes in
place does not pose an unacceptable risk to human health and the environment
assuming institutional controls are maintained. In accordance with CERCLA and
the FF NCO, if an area does not pose an unacceptable risk, cleanup alternatives
that involve excavation, treatment, and disposal elsewhere are not typically
evaluated. Nevertheless,. the selected alternative.(1ong-term.maintenance of the
soil cover, groundwater monitoring, and institutional controls such as restricted
access) was selected to prevent direct contact with the wastes. Maintenance of the
cover is being done to address the uncertainties associated with the risk modeling
and to ensure that Pad A will be a protective unit. ".
Comments Deemed Beyond the Scope of the Pad A ROD
~
Comments and questions on a variety of subjects not specific to Pad A were
received during the public comment period. Those subjects included alternate storage
sites (i.e., WIPP), energy production costs, prior accidents at EBR-I, buffer zones around
the INEL, Swedish bentonite canisters, etc., and are nOt responded to in this
Responsiveness Summary. Additional information on these unrelated subjects can be
obtained from the INEL Public Affairs Office in Idaho Falls or at the local INEL offices
in Pocatello, Twin Falls, and Boise.
..,
-------
-
REFERENCES
Halford et al., 1993, Remedial Investigation/Feasibility Study for Pad A, Operable Unit 7-12,
Waste Area Group 7, Radioactive Waste Management Complex, Idaho National Engineering
Laboratory, July 1993.
~
Environmental Protection Agency, 1990, National Oil and Hazardous Substances
Contingency Plan (NCP), at 40 CFR, ~ 300 et seq. EPA, Office of Emergency and
Remedial Response, Washington, DC.
.
Environmental Protection Agency, 1991, Federal Facility Agreement and Consent Order
1088-06-29-120 in the mailer of the U.S. Department of Energy Idaho National Engineering
Laboratory, Idaho Falls, Idaho. December 1991.
U.S. Depanment of Energy, 1993, Proposed Plan for Pad A at the Radioactive Waste
Management Complex, Idaho National Engineering Laboratory, July 1993.
..
4L
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"
"
APPENDIX B
~UBUC COMMENT/RESPONSE UST INDEX
~
..
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~
APPENDIX B
l'
PUBUC COMMENTJRESPQNSE UST INDEX
Description of Comment/Response List Index
,
This index was created to enable commenters and other interested persons to
locate the agencies responses to public comments. The CommentlResponse List Index is
sorted two ways; by the commenter's last name and by the comment code assigned to
each comment received during the public comment period. All oral comments, as given
at the public meetings, and all written comments, as submitted, were assigned comment
codes. These codes were assigned to assist the agencies and the public identify and track
specific comments. .
Twelve people submitted written comments (comment codes WI - W12) and ten
others gave oral comments at the public meetings (comment codes TI - TIO). These
comments were further divided into 106 individual comments and assigned comment
codes. Copies of oral and written comments annotated with their respective comment
codes are located in the administrative record.
To locate a response to a specific individual's comments, look up the last name of
the individual, identify the specific comment you are looking for, then, turn to the page
indicated in the Responsiveness Summary. . .
If, after reviewing the annotated comments, a reader wishes to locate a response
to a specific comment, he/she can use the comment code to locate a response as well.
The reader should identify the comment code, and page number of the response then
turn to that page of the Responsiveness Summary.
Some of the comments involved multiple issues and those comments were further
divided and answered in more than one place in the Responsiveness Summary. This
occurred in only seven of the 109 comments.
(
..,
-------
APPENDIX B
-
PUBLIC COMMENTIRESPONSE LIST INDEX'
Description of CommentlResponse List Index
~
This index was created to enable commenters and other interested persons to locate
the agencies responses to public comments. The CommentJResponse List Iridex is sorted
two ways; by the commenter's last name and by the ~omment code assigned to each
comment received during the public comment period. All oral comments, as given at the
public meetings, and all written comments, as submitted, were assigned comment codes.
These codes were assigned to assist the agencies and the public identify and track specific
comments. .
.
Twelve people submitted written comments (comment codes ~l - W12) and ten
others gave oral comments at the public meetings (comment codes Tl - TlO). These
comments were further divided into 106 individual comments and assigned comment
codes. Copies of oral and written comments annotated with their respective comment
codes are located in the administrative record.
To locate a response to a specific individual's comments, look up the last name of
the individual, identify the specific comment you are looking for, then, turn to the page
indicated in the Responsiveness Summary.
If, after reviewing the annotated comments, a reader wishes to locate a response 'to
a specific comment, he/she can use the comment code to locate a response as well. The
reader should identify the comment code, and page number of the response then turn to
that page of the Responsiveness Summary.
Some of the comments involved multiple issues and those comments were further
divided and answered in more than one place in the Responsiveness Summary. This
occurred in only seven of the 109 comments.
}
.....
-------
..
.
f
~
APPENDIX B - PUBLIC COMMENTIRESPONSE LIST INDEX
, (Sorted by Commenter's Last Name)
NAME COMMENT CODE I RESPONSE PAGE
Amsden. Dave I Wl-1 I A-20. A-21 I
I .-
Amsden. Dave WI-2 A-I0
B ink. L. W2-1 I A-12
B ink. L. I W2-2 I A-22
Bink. L. I W2-3 I A-22
Bink. L. W2-4 I A-14
Bjornsen. Fritz T5-1 A-5
Bjornsen. Fritz T5-2 A-15
Brice, Donald W3-1 I A-8
Brice. Donald W3-2 A-8
Brice. Donald W3-3 A-9
Brice. Donald W3-4 A-lO
Brice. Donald W3-5 A-lO
Brice. Donald W3-6 I A-15
Brissenden, Marj T6-1 A-15
Brissenden. Marj T6-2 A-24
Broscious. Chuck nO-l A-19
Broscious. Chuck TI0-2 A-II
Broscious, Chuck TI0-3 I A-I0
Broscious, Chuck TI0-4 A-18. A-21
Broscious. Chuck TIO-5 A-5
Broscious. Chuck n 0-6 I A-5
Broscious. Chuc\( TI0-7 A-15 I
Coan. Jacqueline W4-1 I A-17
Coan. JacqueTi"rie - W4-1.1 A-17
Coan. Jacqueline W4-2 A-15
-------
APPENDIX B - PUBLIC COMMENTIRESPONSE LIST INDEX
(Sorted by Commenter's Last Name)
-.,
NAME I COMMENT CODE RESPONSE PAGE
Donnelly, Dennis TI-I A-13
Donnelly. Dennis , TI-2 A-24
Donnelly, Dennis I TI-3 A-24
Donnelly, Dennis I TI-4 I A-23
Donnelly, Dennis TI-5 I A-20
Donnelly, Dennis TI-6 I A-I3
Donnelly, Dennis TI-7 A-18
Donnelly, Dennis TI-8 A-8
Donnelly, Dennis TI-9 A-6
Donnelly, Dennis Ti-IO A-6
Donnelly, Dennis TI-II A-24
Donnelly. Dennis TI-12 I A-6
Donnelly, Dennis I TI-13 I A-23
Donnelly, Dennis I TI-14 A-6, A-23
Donnelly, Dennis TI-15 A-6
Donnelly, Dennis TI-16 A-6, A-20
Donnelly, Dennis TI-17 A-7
Donnelly, Dennis I TI-18 I A-13
Donnelly. Dennis TI-19 A-13 I
Donnelly, Dennis TI-20 A-21
Donnelly, Dennis W5-1 A': 9
Donnelly, Dennis W5-1.1 A-IO
Donnelly, Dennis I W5-2 A-16
Donnelly, Dennis I W5-3 A-8
Donnelly, Dennis W5-4 A-5
- .
Donnelly, Dennis W5-5 A-6
...
.
t
....
-------
APPENDIX B - PUBLIC COMMEl'ITIRESPONSE LIST INDEX
(Soned by Commenter's Last Name)
.~
N AL\'IE I COMMENT CODE RESPONSE PAGE
Fee. Russell. W6-1 I A-21
Horan. John I T2-1 A-13 ..
Horan. John I T2-2 A-23
Horan. John T2-3 A-23
Horan. John I T2--+ I A-23
Horan. John T2-5 A-23
Horan. John I T2-6 A-22
Horan. John T2-7 A-23
Horan, John T:!-S A-23
Horan, John T2-9 A-S
Horan, John I T2-!0 . A-2I
Horan. John T2-11 I A-6
Lenkner. Charles A. W7-1 A-21
Lenkner. Charles A. W7-2 A-II
Lenkner. Charles A. W7-3 A-5
Lenkner. Charles A. W7-4 A-9
Lenkner. Charles A. W7-5 I A--+
Lenkner. Charles A. I W7-6 A-4
Lenkner. Charles A. W7-7 A-23
Lenkner. Charles A. W7-8 A-I5
Lenkner. Charles A. W7-9 A-5
Lugar. Robert M. W8-1 I A-I7. A-21
Lugar. Robert M. W8-2 A-I4
Lugar. Robert M. W8-3 I A-I:!
Lugar. RobercM, W8-4. A-I:!
Merritt. Alan E. W9-1 A-13
i
.
)/
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APPENDIX B - PUBLIC COMMENTIRESPONSE LIST INDEX
(Sorted by Commenter's Last Name)
-
N AL\1E COMMENT CODE I RESPONSE PAGE
Nelson, Lesli~ WI0-l I A-4 I
Nelson, Leslie I WtO-2 I A-4 I
I WtO-3 I A-4 ...
Nelson. Leslie
Nelson. Leslie WtO-4 I A-7
Smith. Don I T7-1 I A-11 I
Tanner, John E. TI-I I A:; 13 I
Toft, Peter F. I WIt-I A-15 .
Toft, Peter F. WII-2 A-6, A-19, A-20
Toft, Peter F. Wl1-3 I A-16
Toft, Peter F. Wl1-4 A-6
Ushman, Michael J. T8-I A-17, A-2t
Ushman, Michael J. T8-2 A-18
Ushman, Michael J. T8-3 I A-I4
Ushman, Michael J. T8-4 A-21
Ushman, Michael J. T8-5 A-23
Ushman, Michael J. T8-6 A-23
Ushman. Michael J. T8-7 A-23
Ushman. Michael J. T8-8 I A-24
Ushman, Michael J. T8-9 I A-I5
Ushman. Michael J. T8-10 A-24
Ushman, Roberta T9-1 A-24
Wehmann, George T4-l A-13
W ehmann, George I T4-2 A-23
W ehmann. George T4-3 A-23
W ehmann. George T4-4 A-6
-... ...
W ehmann, George T4-5 A-23
'f
"
,.
..
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APPE1'IDIX B - PUBLIC COMMENTIRESPONSE LIST INDEX
(Sorted by Commenter's Last Name)
~
~
NAME I COMMENT CODE RESPONSE PAGE
Wehmann, George "T4-6 A-21
Wehmann, George I W12-1 A-21 ...
,
of
"
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PUBLIC COMMENT/RESPONSE LIST INDEX
(Sorted by Comment Code)
;:;..
COMMENT-CODE I NAME RESPONSE PAGE
TI-l I Donnelly, Dennis I A-13 . . u
TI-2 I Donnelly, Dennis I A-24
TI-3 Donnelly, Dennis A-24
TI-~ . I Donnelly. Dennis A-23
I Donnelly, Dennis -
TI-5 A-20
TI-6 Donnelly, Dennis A-13
TI-7 Donnelly, Dennis A-I8
TI-S Donnelly, Dennis A-S
TI-9 Donnelly, Dennis A-6
TI-IO Donnelly, Dennis A-6
TI-II Donnelly, Dennis A-24
TI-I2 Donnelly. Dennis A-6
TI-l3 I Donnelly, Dennis A-23
TI-14 Donnelly, Dennis I A-6, A-23
TI-15 Donnelly, Dennis A-6
TI-16 Donnelly, Dennis A-6. A-20
TI-17 Donnelly, Denni.s I A-7-
TI-18 Donnelly, Dennis A-I3
TI-19 Donnelly, Dennis A-I3
TI-20 Donnelly, Dennis A-2I
T2-1 .-- Horan. John A-I3
TI-2 I Horan. John A-23.
T2-3 Horan, John A-23
T2-~ Horan. John A-23
.... ..
TI-5 Horan. John A-23
'f
~
~
(..t.
-------
"
J
t
~
PUBLIC COMMENTIRESPONSE LIST INDEX
(Sorted by Comment Code)
~~
COMMENT CODE N AL\1E I RESPONSE PAGE
T2-6 Horan, John A-22
I A-23 ..,
T2-7 Horan, John
T2-8 I Horan. John I A-23
T2-9 I Horan. John I A-8
T2-10 I Horan. John I A-21'
T2-II Horan. John A-6
D-l Tanner. John E. A-13
I
T4-1 Wehmann. George A-13
T4-2 Wehmann. George A-23
T4-3 Wehmann. George A-23
T4-4 I Wehmann. George I A-6
T4-5 Wehmann. George I A-23
T4-6 Wehmann. George A-21
T5-l Bjomsen. Fritz A-5
T5-2 Bjomsen. Fritz A-15
T6-l Brissenden. Marj A-15
T6-2 Brissenden. Marj A-24'
17-1 Smith. Don A-12
T8-1 Ushman. Michael J. A-17. A-21
T8-2 Ushman, Michael J. A-18'
T8-3 - Ushman. Michael J. A-14
T8-.:+ Ushman. Michael J. A-21
T8-5 Ushman. Michael J. A-23
T8-6 Ushman. Michael J. A-23
--.-. ..
T8-7 Ushman, Michael J. A-23
T8-8 Ushman. Michael J. A-24
-------
PUBLIC COMMENT/RESPONSE LIST INDEX
(Sorted by Comment Code)
-.
COMME'IT CODE I NAME RESPONSE PAGE
T8-9 Ushman. Michael J. A-15
T8-1 0 I Ushman. Michael J. I A-24. P.
T9-1 I Ushman. Roberta A-24 I
TlO-I Broscious. Chuck A-19
Tl 0- 2 Broscious. Chuck I A-I L .
Tl 0- 3 I Broscious. Chuck I A-IO
Tl 0-4 Broscious. Chuck A-18.- A-21
Tl 0- 5 Broscious. Chuck A-5
Tl 0-6 Broscious. Chuck A-5
Tl 0-7 Broscious. Chuck A-IS
WI-l I Amsden. Dave A-20. A-21
WI-2 Amsden. Dave A-1O
W2-I Bink. L. A-12
W2-2 Bink. L. A-22
W2-3 B ink. L. A-22
W2-4 Bink. L. A-14
W3-I Brice. Donald A-8
W3-2 I Brice. Donald A-8
W3-3 .. Brice. Donald A-9
W3-4 I Brice. Donald A-IO
W3-5 .- Brice. Donald A-1O
W3-6 Brice. Donald A-IS
W4-1 Coan. Jacqueline A-17
W4-1.1 Coan. Jacqueline A-17
W4-2 ---.. ~ Coan. Jacqueline A-IS
W5-1 Donnelly, Dennis A-9
'f
~
~
'-.t
-------
PUBLIC COMMENTIRESPONSE LIST INDEX
(Sorted by Comment Code)
-
(
COMMENT CODE NAME RESPONSE PAGE
W5-1.l Donnelly. Dennis A-lO
W5-2 Donnelly, Dennis I A-16
W5-3 Donnelly. Dennis A-8
W5-4 I Donnelly, Dennis A-5
W5-5 Donnelly, Dennis A-6-'
W6-1 Fee. Russell A-21
W7-l Lenkner. Charles A. A-21
W7-2 Lenkner. Charles A. A-ll
W7-3 Lenkner. Charles A. A-5
W7-4 Lenkner. Charles A. I A-9
W7-5 Lenkner. Charles A. A-4
W7-6 Lenkner. Charles A. A-4
W7-7 Lenkner. Charles A. A-23
W7-8 Lenkner. Charles A. A-15
W7-9 Lenkner. Charles A. A-5
W8-1 Lugar. Robert M. A-17. A-21
W8-2 Lugar. Robert M. A-14"
W8-3 Lugar. Robert M. A-12
W8-4 Lugar. Robert M. A-12
W9-1 Merritt. Alan E. A-13"
WIO-I - Nelson. Leslie A-4
WIO-2 Nelson, Leslie A-4
WlO-3 Nelson. Leslie A-4
WIO-4 Nelson. Leslie A-7
..-- .
WIl-l Toft. Peter F. A-I5
WII-2 Toft. Peter F. A-6. A-19, A-20
~
-'
",..
-------
PUBLIC COMMENTIRESPONSE LIST INDEX
(Sorted by Comment Code)
COMMENT CODE NAME RESPONSE PAGE
Wll-3 I Toft. Peter F. A-16
Wll-4 Toft. Peter F. A-6 ...
W12-1 Wehmann. George A-21
B-13
:....
...
.t..
)
-------
-'
~
,
.
APPENDIX C
ADMINISTRATIVE RECORD INDEX
~
~
-------
~
.;)
f,
~
IDAHO NATIONAL ENGINEERING LABORATORY
ADMINISTRATIVE RECORD FILE INDEX FOR THE RWMC PAD A RIIFS FOR
OPERABLE UNIT 7-12
03/02/94 .
FILE NUMBER
AR1.1
BACKGROUND
Document #: 5306
Title: Subtitle D: How will it affect Landfills?
Author: Glebs, R.T.
Recipient: N/A
Date: 08/01/88
'"
Document #: 5307
Title: Water-Rock Interaction - Proceedings 01 the 7th International
Symposium on Water-Rock Interaction
Pittman, J.R.
N/A
07/01/92
'"
Author:
Recipient:
Date:
Document #: 5308
Title: Erosion Modeling Results and Erosion Control Design
Recommendations Pad A Operable Unit 7-12
Dorigan, L
EPA
12/01/92
'"
Author:
Recipient:
Date:
Document #: DOElID-10183**
Title: Annual Progress Report: FY-1987
Author: Laney, P. T.
Recipient: N/A
Date: 04/01/88
'"
Document #: DOElID-22073
Title: Hydrogeology and Geochemistry 01 the Unsaturated Zone, RWMC, INEL
Author: Rightmire, C.T.
Recipient: N/ A
Date:. 11/01/87
'"
Document #: EGG-GEO-10068
Title:---- - A Modeling Study 01 Water Flow in the Vadose Zone Beneath the
RWMC
Baca, R.G.
N/A
011/01/92
.",
Author:
Recipient:
Date:
-------
.-
PAD A RIIFS FOR OPERABLE UNIT 7-12
03/02/94
~
FILE NUMBER
AR1.1
t
BACKGROUND (continued)
.
Document #: WM-F1-81-o15
Title: INEL Stored Transuranic Waste Characterization:
Hazards Identification
Clements, T.L
N/A
09/01/81
Nonradiological"
Author:
Recipient:
Date:
.
Document #: EGG-2386
Title: Environmental Surveillance For The INEL RWMC and Other Areas
Author: Reyes, B.D.
Recipient: NI A
Date: 08/01/85
.
Document #: DOElID-12118
" Title: Climatography of the INEL, 2nd Edition
Author: Clawson, KL
Recipient: N/A
Date:- 12/01/89
.
Document #: DOElID-22080
Title: Stratigraphy of the Unsaturated Zone at the RWMC at the INEL
Author: Anderson, S.R.
Recipient: N/A
Date: 05/01/89
AR3.2
SAMPUNG AND ANALYSIS DATA
.
Document #: RLN-04-93 "
Title: Review of Sampling Data Affecting the Pad A Risk Assessment
Author-:- Norland, R.L. .
Recipient: Macdonald, D.W.
Date: 01/12/92
.
Document #:
Title:
Author:--" -
Recipient:
Date:
'¥
ERD-BWP-70
Results of Pad A Overburden Sampling
Rice, R.S.
N/A
07/01/92
),
-------
~
J'
~
-.I
FILE NUMBER
AR3.10
PAD A RIIFS FOR OPERABLE UNIT 7.12
03/02/94
SCOPE OF WORK
Document #: ERD1-oso-91
Title: Transmittal 01 Draft Scope 01 Work for the Waste Area Group 7 Pad A
RIIFS at the INEL
Lyle, J.L
Pierre, W., Nygard, D.
04/30/91
.&
Author:
Recipient:
Date:
Document #: ERD1-QS8-91
Title: Transmittal 01 Draft Final Scope 01 Work for the Waste Area Group 7
Pad A RIIFS at the INEL
Lyle, J.L
Pierre, W., Nygard, D.
06/04/91
.&
Author:
Recipient:
Date:
Document #: 5327
Title: Final Scope of Work (SOW) Remedial InvestigationlFeasibility Study
(RI/FS) at Pad A of the Radioactive Waste Management Complex
(RWMC)
Nygard, D.
Lyle, J.L
08/21/91
.&
Author:
Recipient:
Date:
.&
Document #:
Title:
Author:
Recipient:
Date:
ERD-Q51-92
Revisions to Pad A Scope 01 Work
Lyle, J.L .
Pierre, W., Nygard, D.
04/08/92
Document #: 5320
Title: Revision to Pad A Scope 01 Work
Aufffor: Nygard, D.
Recipient: Lyle, J.L
Date: 04/30/91
.&
Document #: 5326
Title: Revisions to INEL Pad A Scope 01 Work
Author: - Pierre, W.
Recipient: Lyle. J.L
Date: 05/11/92
.&
-------
Document #: EGG-WM-9792 Rev. 4
Title: Draft Final Scope of Work Pad A Remedial Investigation/Feasibility
Study
Halford, V. E. & Matthem, G. E.
N/A
04/01/91
REMEDIAL INVESTIGATION FEASIBIUTY STUDY -
FILE NUMBER.
AR3.10
.
Author:
Recipient:
Date:
AR3.12
PAD A RIIFS FOR OPERABLE UNIT 7-12
03/02/94
y:
SCOPE OF WORK (continued)
-L
Document #: ERD-OSQ-92
Title: Transmittal of the RWMC Pad A Draft RI/FS
Author: Lyle, J.L
Recipient: Pierre, W., Nygard, D.
Date: 06/03/92
.
.
Document #:
Title:
Author:
Recipient:
Date:
EGG-WM-9967, Vol. 01
Remedial Investigation/Feasibility Study (RI/FS) For Pad A
Halford, V. E.
N/A .
07/01/93
Document #: EGG-WM-9967, Vol. 02
Title: Remedial Investigation/Feasibility Study (RI/FS) For Pad A
Author: Halford, V. E.
Recipient: N/A
Date: 07/01/93
.
Document #: AM/ERWM-ERD-QOS-93
Title: Transmittal Letter, Final Remedial Investigation/Feasibility Study (RI/FS)
For Pad A Operable Unit in Waste Area Group 7 (WAG 7)
Lyle, J.L
Pierre, W., Nygard, D.
02/11/93
Document #: 5335
Title: Cost Estimate Breakdown for Pad A Post Closure Operations - Annual
Environmental Monitoring
Dames & Moore
Halford, V.E.
05/03/93
.
Author-;.-
Recipient:
Date:
AR3.13
.
Author:
Recipient:
Date:
COST ANALYSIS
,"
'if
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~
FILE NUMBER
j'
AR4.3
.
.
AR5.1
.
.
.
j.'
I
',I
PAD A RIIFS FOR OPERABLE UNIT 7.12
03/02/94
PROPOSED PLAN
Document #: ERWM-ERD-033-93
Title: Draft Proposed Plan (PP) for the Pad A Operable Unit (OU) 7-12 in
Waste Area Group (WAG) 7
Lyle, J.L
Pierre, W., Nygard, D.
05/21/93
Author:
Recipient:
Date:
Document #: 5342
Title: Proposed Plan for Pad A at the Radioactive Waste Management
Complex (RWMC) Idaho National Engineering Laboratory (INEL)
INEL Community Relations
N/A
07/01/93
RECORD OF DECISION
Author:
Recipient:
Date:
Document #: ER-093-93 ,
Title: Transmittal 01 the Draft Record 01 Decision for the Pad A Remedial
Investigation/Feasibility Study at the RWMC
Lyle, J.L
Pierre, W.; Nygard, D.
10/04/93
Author:
Recipient:
Date:
Document #: OPE-ER-073-93
Title: Transmittal 01 the, Draft Final Record 01 Decision for the Pad A Remedial
Investigation/Feasibility Study at the RWMC '
Lyle, J.L '
Pierre, W.; Nygard, D.
12123/93
Author:
Recipient:
Date:
DO'coment #: 5632
Title: Record 01 Decision 10r the Pad A Remedial Investigation/Feasibility
Study at the RWMC
INEL, EPA, IDHW
N/A
02117/94
Author:
Recipient:
Date:
-------
Document #: DOElID-10340(92)*
Title: _.n. - Track 1 Sites: Guidance for Assessing Low Probability Hazard Sites at
the INEL
INEL, EPA, IDHW
N/A
07/01/92
FILE NUMBER
AR6.1
.
Document #:
Title:
Author:
Recipient:
Date:
.
Document #:
Title:
Author:
Recipient:
Date:
.
Document #:
Title:
Author:
Recipient:
Date:
.
Document #:
Title:
Author:
Recipient:
Date:
.
Document #:
Title:
Author:
Recipient:
Date:
.
Author:
Recipient:
Date:
PAD A RIIFS FOR OPERABLE UNIT 7-12
03/02/94
y.
(.,
COOPERATIVE AGREEMENTS
ERD1-o7Q-91 *
Pre-signature Implementation of the CERCLA Interag_ency Agreement
Action Plan .
EPA, Findley, C. E.
DOE, Solecki, J. E.
05/17/91
32Q5*
U.S. DOE INEL Federal Facility Agreement and Consent Order
N/A
N/A
07/22/91
2919*
INEL Action Plan For Implementation of the Federal Facility Agreement
and Consent Order .
N/A
N/A
. 07/22/91
1 088-06-29-120*
U.S. DOE INEL Federal Facility Agreement and Consent Order
NM .
N/A
12/04/91
3298* .
Response to Comments on the Idaho National Engineering Laboratory
Federal Facility Agreement and Consent Order
N/A
N/A
02/21/92
-l-
~
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)
I
FILE NUMBER
;)
J
AR6.1
AR6.3
.
AR6.4
.
.
.
~
~
PAD A RIIFS FOR OPERABLE UNIT 7.12
03/02194
COOPERATIVE AGREEMENTS (continued)
Document #: DOElID-10389 Rev. 6*
Title: Track 2 Sites: Guidance for Assessing Low Probability Hazard Sites at
the INEL
INEL. EPA, IDHW
N/A
01/01/94
PROJECT MANAGEMENT MEETING MINUTES
Author:
Recipient:
Date:
Document #: 5305
Title: Minutes From Teleconference Held With IDHW and EPA Regarding
Pad A
INEL Community Relations
N/A
11/17/92
REQUEST FOR EXTENSION
Author:
Recipient:
Date:
Document #:
Title:
Author:
Recipient:
Date:
5328
Draft RIIFS For Pad A at the Radioactive Waste Management Complex
(OU 7-12)
Nygard, D.
Lyle, J.L, Pierre, W.
07/17/92
Document #: 5329
Title: INEL Operable Unit 7-12 Pad A Draft RIIFS .
Author: Pierre, W.
Recipient: Lyle, J.L
Date: 07/17/92
Document #: AM/ERWM-ERD-093-92
Title: Extension of Document Finalization Period For the Pad A Remedial
Investigation Feasibility Study (RI/FS) Area Group 7 (WAG 7)
Lyle, J.L
Pierre, W., Nygard, D.
09125/92
Author:
Recipient:
Date:'-- -
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FILE NUMBER
AR6.4
PAD A RIIFS FOR OPERABLE UNIT 7-12
03/02/94
~.
REQUEST FOR EXTENSION (continued)
L
Document #: AM/ERWM-ERD-098-92
Title: Request for Extension for Preparation of a Revised Draft Final RVFS for
the Pad A Operable Unit at WAG 7
Lyle, J.L
Pierre, W., Nygard, D.
11/16/92
.
Author:
Recipient:
Date:
Document #: 5330
Title: Extension Approval for Preparation of the Revised Draft Final RI/FS For
the Pad A Operable Unit at WAG 7
Nygard, D.
Lyle, J.L
11/20/92
Document #: AM/ERWM-ERD-003-93
Title: Notification of Fifteen (15) Day Extension to the Pad A RIIFS for the
Pad A Remedial Investigation Feasibility Study (RI/FS) Working
Schedule
Lyle, J.L
Pierre, W., Nygard, D.
01/20/93
NOTICES ISSUED
.
Author:
Recipient:
Date:
.
Author:
Recipient:
Date:
AR9.1
..
Document #: AM/SES-ESO-92-256.
Title: Natural Resource Trustee Notification
Author: Pitrolo, A.A.
Recipient: Andrus, C,D,
Date: 07/07/92
.
.
Document #: AM/SES-ESD-92-257
Title: Natural Resource Trustee Notification
Author: Pitrolo, A.A.
Recipient: Polityka, C.
Date: 07/07/92
.
~t
.
Document #: AM/SES-ESD-92-258
Title: Natural Resource Trustee Notification
Author: Pitrolo, A.A.
Recipient: Edmo, K.
Date: 07/07/92
.
~
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~
FILE NUMBER
;',
J
AR9.1
..
..
..
..
..
~
..
,~
PAD A RIIFS FOR OPERABLE UNIT 7-12
03/02/94
NOTICES ISSUED (continued)
*
Document #: AM/SE5-ESD-93-007
Title: Invitation to Natural Trustee Representatives to Discuss Natural
Resources and Environmental Restoration at the INEL
Hinman, M.B.
Addressee Ust
01/25/93
Author:
Recipient:
Date:
*
Document #: AMlSE5-ESD-93-097
Title: Agenda for Meeting of Potential Natural Resource Trustees' on
March 17, 1993
Twitchell, R.L
Addressee Ust
03/02/93
Author:
Recipient:
Date:
Document #: AM/SES-ESD-93-159*
Title: INEL Natural Resource Trustee Meeting "Group Memory" March 17,
1993
Hinman, M.B.
Addressee Ust
03/30/93
Author:
Recipient:
Date:
*
Document #: AM/SES-ESD-93-162
Title: Department of Energy Idaho Field Office (DOE-ID) Proposal for
Consultation and Coordination between Natural Resource Trustees
Hinman, M.B. . .
Addressee Ust .
04/02/93
Author:
Recipient:
Date:
*
Document #: AM/SE5-ESD-93-276 .
Title: Department of Energy Idaho Field Office (DOE-ID) Action Item Report to
Potential Natural Resource Trustees
Hinman. M.B.
Addressee Ust
06/16/93
Author:
Recipient:
.Date:
Document #: 5337.
Tltle:"u - Natural Resource Trustee Representation Designation
Author: Andrus, C.D., Governor
Recipient: Pitrolo, A.A.
Date: 08/11/92
-------
FILE NUMBER
AR9.1
.
Document #:
Title:
Author:
Recipient:
Date:
AR10.1
.
Document #:
Title:
Author:
Recipient:
Date:
PAD A RIIFS FOR OPERABLE UNIT 7.12
03/02194
Ie
NOTICES ISSUED (continued)
t,
53388
Response to Natural Resource Notification
Polityka, C.S.
Pitrolo, A.A.
08/28/92
COMMENTS AND RESPONSES
5313
Draft Scope of Work for Pad A Remedial Action at the INEL Radioactive
Waste Management Complex
Pierre, W.
Lyle, J.L
05/08/91
Document #: 5332
Title: Draft Scope of Work for Pad A Remedial Investigation Feasibility Study
at the INEL Radioactive Waste Management Complex
Nygard, D.
Lyle, J.L
05/16/91
.
Author:
Recipient:
Date:
Document #: 2775
Title: Draft Final Scope of Work Remediallnvestigation/Feasibility Stud at Pad
A of the Radioactive Waste Management Complex (RWMCr " .
Nygard, D.
Lyle, J.L
06/17/91
Document #: 5314
Title: Review of Draft Remedial InvestigationlBaseline Risk Assessment Report
for Pad A OU 7-12, Revision 1, August 1991
Nygard, D.
Lyle, J.L
1 0/03/91
.
Author: .
Recipient:
Date:
.
Author:
Recipient:
Date:
.
Document #:
Title:
Author:
Recipient:
Date:
r
c.
3231
Draft RWMC Pad A Remedial Investigation Report
Pierre, W.
Lyle, J.L
1 0/03/91
.~
-------
j
,
FILE NUMBER
J
AR10.1
..
Document II:
Title:
Author:
Recipient:
Date:
PAD A RIIFS FOR OPERABLE UNIT 7-12
03/02194
COMMENTS AND RESPONSES (continued)
ERD1-Q3D-92
Pad A RIIBRA Comment Resolutions
Lyle, J.L
Pierre, W., Nygard, D.
02/27/92
Document #: 6045 -
Title: INEL RWMC - Comments on Draft RVFS for Pad A OU 7-12 WAG 7
RWMC INEL, April 1992
Nearman, M.J.
Macdonald, D.
08/1 0/92
..
Author:
Recipient:
Date:
Document #: 5319
Title: Technical Review Comments for Draft Remedial Investigation/Feasibility
Study for Pad A at the RWMC (OU 7-12)
Nygard, D.
Lyle, J.L
08/1 0/92
..
"Author:
Re~ipient:
Date:
Document #: AMIERWM-RPO-235-92
Title: Draft Final Remedial Investigation Feasibility Study (RI/FS) for the Pad A
Operable Unit in Waste Area Group 7 f'NAG 7)
Lyle, J.L
Pierre, W., Nygard, D.
10/14/92
..
Author:
Recipient:
Date:
Document II: AM/ERWM-ERD1-28D-92
Title: Modified Draft Final Remedial Investigation Feasibility Study (RI/FS) for
the Pad A Operable Unit in Waste Area Group Seven f'NAG 7)
Lyle, J.L
Pierre, W., Nygard, D.
12/16/92
Document II: 5310
Title: INEL WAG 7 RWMC Pad A - Comments on the Modified Final Remedial
Investigation/Feasibility Study
Nearman, M.J.
Macdonald, D.
01/12/93
..
Auttlor:
Recipient:
Date:
~
..
..."
Author:
Recipient:
Date:
-------
FILE NUMBER
AR10.1
. 'f"
PAD A RIIFS FOR OPERABLE UNIT 7.12
03/02194
~
COMMENTS AND RESPONSES (continued)
,
t
Document #: 6114
Title: Technical Review Comments on the Modified Draft Final Remedial
Investigation Feasibility Study
Nygard, D.
Macdonald, D.
01/19/93
.
Author:
Recipient:
Date:
Document #: 5362
Title: INEL WAG 7 - Pad A Draft Proposed Plan, Revision 3, May 1993
(Review Comments)
Nearman, M.J.
Macdonald, D.
06/06/93
.
Author:
Recipient:
Date:
Document #: 5363
Trtle: INEL WAG 7 - Pad A Draft Proposed Plan, Revi~ion 4 (Review
Comments)
Nearman, M.J.
Macdonald, D.
06/28/93
.
Author:
Recipient:
Date:
Document #: 5615
Trtle: Review Comments from EPA on the INEL WAG 7 Pad A - Draft Record
01 Decision Revision 1, dated September 1993
Nearman, M.J. . . . . ...
Macdonald, D.
11/17/93
Document #: 5616
Trtle:-- Review Comments From IDHW For The Preliminary Working Draft
Record of Decision For Pad A at the Radioactive Waste Management
Complex at the Subsurface Disposal Area
Koch, D.
Hula, G.
11/19/93
.
Author:
Recipient:
Date:
.
Author:
Recipient:
Date:
"
>(
-------
~
FILE NUMBER
~
AR10.1
PAD A RalFS FOR OPERABLE UNIT 7-12
03/02194
COMMENTS AND RESPONSES (continued)
Document #: 5608
Title: Resolution to comments on the Draft Record 01 Decision 10r Pad A sent
to EPA
DOE-ID
EPA
11/22/93
Document #: 5607
Title: Resolution to comments on the Draft Record 01 Decision for Pad A sent
to IDHW
DOE-ID
IDHW
11/22./93
OPE-ER-D23-94
Responses to comments on the Draft Final Record 01 Decision 10r Pad
A at Waste Area Group 7 ~AG 7)
Green, L
Pierre, W.; Nygard, D.
11/22./93
.
Author:
Recipient:
Date:
.
Author:
Recipient:
Date:
.
Document #:
Title:
Author:
Recipient:
Date:
AR10.3
.
Document #:
Title:
Author:
Recipient:
Date:
.
Document #:
Title:
i
'I
Author:
Recipient:
Date:
.~
PUBUC NOTICES
5321
Public Noti~e 01 Scoping Meeting
INEL Community Relations
N/A
11/01/91
5502
Public Meeting on the Proposed Plan for Pad A at the Boise Public
Ubrary
INEL Community Relations
N/A
08/16/93
-------
FILE NUMBER
AR10.3
PAD A RIIFS FOR OPERABLE UNIT 7-12
03/02/94
~
PUBUC NOTICES
r
Document #: 5503
Title: Public Meeting on the Proposed Plan for Pad A at the Idaho Falls
Westbank Inn
INEL Community Relations
N/A
08/16/93
.
Author:
Recipient:
Date:
Document #: 5504
Title: Public Meeting on the Proposed Plan for Pad A at the Moscow
University Inn
INEL Community Relations
N/A
08/16/93
.
Author:
Recipient:
Date:
AR10.4
PUBUC MEETING TRANSCRIPTS
Document #: 5568 .
Title: Transcripts - Task 10.04 - Community Relations Meeting Assistance:
Pad A Public Meetings in Idaho Falls, Boise, and Moscow
Hemphill, C.J.
Hula, G.
10/01/93
.
Author:
Recipient:
Date:
Document #: 5631
Title: Cross Reference Document ForOral/Written .comments OR Proposed. - - -
Plan and the Pad A Record of Decision
.. Brown, D.L .
Hula, G.
04/03/94.
Document #: 5333
Title: Summary of Public Scoping Comments Concerning Proposed
Remediation of Pad A
ASI
N/A
12104/91
.
Author:
Recipient:
Date:
AR10.5
.
Author: --- - .
Recipient:
Date:
DOCUMENTATION OF OTHER PUBUC MEETINGS
:r
l'
-------
.t
}
~
j
. AR11.1
NOTE:
)'
*
i
**
PAD A RIIFS FOR OPERABLE UNIT 7-12
03/02/94
FILE NUMBER
AR10.6
FACT SHEET
..
Document #: 3391
Title: Public Scoping Meetings Planned for Pad A
Author: INEL Community Relations
Recipient: N/A
Date: 11/20/91
EPA GUIDANCE
..
Document #: 5163 Revision 3-
Title: Administrative Record Ust of Guidance Documents
Author: EPA
Recipient: N/ A
Date: 08/12192
Documents listed as bibliographic sources in the Pad A Remedial
InvestigationlF~asibility Study Report, might not be listed separately in this
index, but nonetheless may have been used in the decision process tor
Pad A.
Document filed in INEt Federal Facility Agreement and Consent Order (FFA/CO)
Administrative Record Binder
Document filed in INEt Pit 9 Administrative Record Binder
C-16
------- |