United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R10-92/045
September 1992
c/EPA Superfund
Record of Decision:
US DOE Idaho National
Engineering Lab (Operable
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.-j
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.
NOTICE
.
The appendices listed in the index that are not found in this document have been removed at the request of
the issuing agency. They contain material which supptement. but adds no further applicable information to
the content of the document. All supplemental material is. however. contained in the administrative record
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REPORT DOCUMENTATION 11. REPORTNO. - 1 ~ 3. Recillienl'a Acceuion No.
PAGE EPA/ROD/R10-92/045
4. TitleandSubtiIle SUPERFUND RECORD OF DECISION s. Report Date
US DOE Idaho National Engineering Laboratory 09/28/92
(Operable Unit 2), ID 6.
Third Remedial Action - Subseauent to follow
7. Author(a) 8. Pei10rming Organization Rept. No.
9. Performing Orgainlzation Name and Addle.. 10. ProjeclfTukJWork Unit No.
11. Contnct(C) or Granl(G) No.
(C)
(G)
12. Sponaoring Organization Name and Addreaa 13. Type of Repor1 & Period Covered
U.S. Environmental Protection Agency 8001000
401 M Street, S.W.
Washington, D.C. 20460 14.
1 s. Supplementary Noletl
PB93-964615
16. Abe1ract (Umit: 200 words)
The 890-square mile Idaho National Engineering Laboratory (INEL) is located 32 miles
west of Idaho Falls, Idaho. The site, established in 1949, is operated as a nuclear
reactor technology development and waste management facility by the U.S. Department of
Energy. Land use in the area is predominantly industrial and mixed use. The site
overlies a sole source Class I aquifer, the Snake River Plain Aquifer. A
10-mile-square area within the INEL complex, referred to as Test Area North (TAN), was
built in the 1950's to support the Aircraft Nuclear Propulsion Program sponsored by the
U. S. Air Force and Atomic Energy Commission. Within TAN, the Technical Support
Facility (TSF-05) injection well was used to dispose of industrial and sanitary wastes
and wastewaters from 1953 to 1972. Types of wastes disposed of in the well included
low-level_radioactive and process wastes, corrosive wastewater, ignitable wastes,
chromium, lead, and mercury. Contaminants, including TCE, PCE, tritium, and
strontium-90, were first detected above MCLs in the ground water in 1987. Based on
these results, a RCRA Corrective Action Program was subsequently developed to address
ground water contamination at TAN, which included installation of an air sparging
system in the water supply tank at the TSF to ensure that organic contaminant
concentrations remain below regulatory levels. Ground water sampling and monitoring
(See Attached Page)
17. Document Analysis L Descriptors
Record of Decision - US DOE Idaho National Engineering Laboratory (Operable Unit 2), ID
Third Remedial Action - Subsequent to follow
Contaminated Medium: gw
Key Contaminants: VOCs (PCE, TCE), metals (lead), radioactive materials
b. Identifiers/Open-Ended Tenna
c. COSA 11 FieIdIGroup
18. Availability Statement 19. Security Clan (Thia Report) 21. No. of Pages
None 50
20. Security Clan (Thia Page) n Price
None
272 (4-77)
.
50272-101
(See ANSl-Z39.18)
See InslruCtJons on Revel8e
(Fonnerty NTI~)
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gPA/ROD/R10-92/045
US DOE Idaho National
(Operable Unit 2), ID
Third Remedial Action
Engineering Laboratory
- Subsequent to follow
Abstract (Continued)
continued through 1990, and contaminated sludge from the lower 55 feet of the TSF-OS
injection well was removed and analyzed in 1990. Currently, the TSF-05 injection well is
closed securely and locked, and the well head has been sealed against surface water.
intrusion. The INEL site is divided into 10 Waste Area Groups (WAGs). Two RODs in 1991
and 1992 addressed an interim remedy for Warm Waste Pond sediment in WAG 2 and an interim
remedy for unexploded ordnance and soil contamination in WAG 10. This ROD provides an
interim remedy for ground water contamination near the TSF-05 injection well (WAG 1) .
The primary contaminants of concern affecting the ground water are VOCs, including TCE
and PCE; metals, including lead; and radioactive materials.
The selected remedial action for this site includes pumping the contaminated ground water
from the injection well and treating the ground water onsite using filtration to remove
suspended solids, followed by air stripping and carbon adsorption to remove organics, and
ion exchange to remove inorganics and radionuclides; modifying the existing TAN onsite
disposal pond to receive treated ground ~ater and ensure that it does not exceed
discharge limits; transporting any spent carbon offsite to a permitted facility for
regeneration; installing two additional ground water monitoring wells within the
contaminant plume; monitoring air emissions; and implementing administrative and
institutional controls, including ground water use restrictions. The estimated capital
cost for this remedial action is $7,715,000, with a total O&M cost of $3,194,000 for 2
years.
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific ground water clean-up goals, which are based on SDWA MCLs, and
TCE 5 ug/l; PCE 5 ug/l; lead 50 ug/l; and strontium-90 300 pCi/l. Air emissions
will be monitored and will not exceed state air quality standards, which include
TCE.00051 lb/hr; PCE. 0.013 lb/hr; lead 1.5 ug/m3; and strontium-90 10 mrem/yd.
include
also
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September 1992
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DE CLARA TION OF THE RECORD OF DECISION
Site Name and Location
TSF Injection Well (TSF-05) and Surrounding Groundwater Contamination (TSF-23)
Operable Unit (OU) 1-07A
Waste Area Group I
Idaho National Engineering Laboratory
Idaho Falls, Idaho
Statement of Basis and Purpose
This decision document presents the selected interim remedial action for the Technical Support Facility
(TSF) Injection Well (TSF-OS), and the groundwater surrounding the injection well (TSF-23) as described in the
Federal Facility Agreement/Consent Order (FF AlCO). This action was chosen in accordance with the Compre-
hensive Environmental Response, Compensation, and Liability Act (CERCLA) as amended by the Superfund
Amendments and Reauthorization Act (SARA), and to the extent practicable, the National Oil and Hazardous
Substances Pollution Contingency Plan (NCP). 'Ibis decision is based on the Administrative Record for the site.
The State of Idaho Department of Health and Welfare (IDHW) concurs with the selected remedy.
Assessment of the Site
Actual or 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 an imminent and substantial endanger-
ment to public health, welfare',<2Ethe environment
Description of the Selected Remedy
This interim action is intended to prevent further degradation of the groundwater by reducing contami-
nants near the TSF-OS injection w~ll and in the surrounding groundwater. The selected remedy will also not be
inconsistent with nor preclude the.-implementation of the final response action scheduled to be detennined in
1994:
The major components of the selected remedy include:
.
Extract contaminated groundwater from the TSF-OS injection well and perhaps nearby groundwater
monitoring wens that are capable of capturing contaminated groundwater.
.
Install two groundwater monitoring wells within the contaminant plume to monitor the effectiveness of
the interim action. These wells may also be used as extraction wells to expedite the removal of contami-
nated groundwater.
.
Install on-site groundwater treatment facilities to reduce contaminants of concern in the extracted ground-
water to prescribedperfonnance Standards. The selected treatment system is air Stripping. carbon adsorp-
tion, and ion exchange.
Hi
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Monitor the groundwater contaminant plume and the extraction/treatment system during groundwater
extraction activities to track the effectiveness of the system-and to ensure that perfonnance standards are
achieved. .
.
Modify the existing Test Area North (TAN) disposal pond to receive the treated groundwater and ensure
that discharge water quality does not further degrade the underlying Snake River Plain Aquifer above
maximum contaminant levels.
I
Implement administrative and institutional controls that supplement engineering controls and minimize.
exposure to releases of hazardous substances during remediation.
Statutory Determinations
This interim action is protective of human health and the environment, complies with. Federal and State
applicable or relevant and appropriate requirementS for this limited-scope action, and is cost-effective. Although
this interim action is not intended to fully address the statutory mandate for permanence and treatment to the
maximum extent practicable. this interim action utilizes treatment and thus is in furtherance of that statutory
mandate. .
Although this is an interim action. it is intended to prevent further degradation of the groundwater until
the final remedy for au 1-07 is selected. Because this action does not constitute the final remedy for au 1-07.
the statutory preference for remedies that employ treatment that reduces toxicity, mobility, or volume as a princi-
pal element, although partially addressed in this remedy. will be addressed by the final response action. Subse-
quent investigations are planned to address the potential threatS posed by the conditions at au 1-07.
Because this remedy wiU result in hazardous substances remaining on site above health-based levels. a
review will be conducted to ensure that the remedy continues to provide adequate protection of human health and
the environment within two years after commencement of the remedial action. Because this is an interim action
ROD, review of these sites and of this remedy will be continuing while developing final remedial alternatives for
au 1-07. .
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Signature sheet for the foregoing Operable Unit 1-07A TSF-05 injection well and SUITounding groundwater
interim action at the Test Area North at the Idaho National Engineering Laboratory Record of Decision betWeen
the United States Department of Energy and the United States Environmental Protection Agency, with
concurrence by the Idaho Department of Health and Welfare.
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Augustine A. Pitrolo
Manager
Department of Energy, Idaho Field Office
Date
...;
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Signature sheet for the foregoing Operable Unit 1-07 A TSF-05 injection well and surrounding groundwater
interim action at the Test Area North at the Idaho National Engineering Laboratory Record of Decision betWeen
the United States Deparonent of Energy and the United States Environmental Protection Agency. with
concurrence by the Idaho Department of Health and Welfare.
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X/.Q. /Jrt~ Ci::..- .~:::../Yo ~ .v~ --
Dana Rasmussen
Regional Administrator, Region 10
Environmental Protection Agency
SEP 2 8 1992
Date
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. _n_.-
Signature sheet for the foregoing Operable Unit 1-07 A TSF-OS injection well and surrounding groundwater
interim action at the Test Area North at the Idaho National Engineering Laboratory Record of Decision betWeen
the United Stares Department of Energy and the United States Environmental Protection Agency. with
concurrence by the Idaho Department of Health and Welfare.
"
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, '
Richard Donovan
Director
Idaho Department of Health and Welfare
. Date
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vii
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CONTENTS
DECLARA nON OF THE RECORD OF DECISION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ill
Acronyms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
DECISION SUMMARY
Site Name. Location and Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Site History and Enforcement Actions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Highlights of Community Participation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Scope and Role of the Operable Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Summary of Site Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Summary of Site Risks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Description of Alternatives. . . . . . . . . . . . . . . .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . .. . . . . . .20
Summary of Comparative Analysis of Alternatives. .. . . . . .. . . . . . . . . . . . . . . . . . . . . .. . .. . . . . . . . . .22
Selected Remedy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
StaDltory Detennination [[[ 32
Explanation of SignificaIlt Differences. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . .34
Appendix A - Responsiveness Summary.. . .. . .. .. .. .','.. . . . ..... ... .. . . . ... .. . . .. """ .. . .. . . .A-l
Appendix B - Public Comment/Response List [[[ B-1
Appendix C - Administrative Record Index. . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . .. . .. . . . . . . . .. .. .C-l
TABLES
2-1. Facilities suspected of using the TSF-05 well for waste disposal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2-2. Curies released to the TSF-05 injection well (by nuclide) (1959 to August 1972) . . . . . . . . . . . . . . . . . . . . .5
2-3. Concentration of groundwater contaminants of concern. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
5-1. Groundwater monitoring well data [[[ 12
5-2. Maximum detected concentrations of contaminants detected by the USGS
in groundwater samples at TAN 1987-1989. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5-3. Contaminant concentration in TSF-05 injection well sludge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
6-1. Contaminants of concern. thier respective MCLs. and risk-based concentrations. . . . . . . . . . . . . . . . . . . .20
8-1. Comparative evaluation of alternatives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
8-2. Cost breakdown for alternatives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
9-1. Waste treatment. storage. and disposal options for investigation-
derived, laboratory. and treatment process wastes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
9-2. Interim performance standards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
FIGURES
1-1. Test Area North at the Idaho National Engineering Laboratory. . . . . . . . . .. . . . . . . . . .. . . . . .. . . . . . . . . I
1-2. Facilities at the Test Area North. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
5-1. Hydrogeological profile of the Test Area North. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
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ACRONYMS
. ANP Aircraft Nuclear Program
ARARs applicable or relevant and appropriate requirementS
BDAT Best Demonstrated A vailable TechnOlOgy
. CERCLA Comprehensive Enviromnental Response. Compensation. and Liability Act
CFA Central Facilities Area
. CFR Code of Federal Regulations
. Ci Curies
. CLP ContraCt Laboratory Program
. COCA Consent Order and Compliance Agreement
. CRP Community Relations Plan
. DOE Department of Energy . , '.
. EPA Enviromnental Protection AgenCY
. FET Flight Engine Test facility
. FF AlCO Federal Facility Agreement/Consent Order
. FR Federal Register
. gpd gallons per day
. gpm gallons per minute
. III Hazard Index
ICPP Idaho Chemical Processing Plant
. IDAPA Idaho Administrative Procedures ACt
. IDHW State of Idaho DeparttDent of Health and Welfare
. lET Initial Engine Test Facility
. INEL Idaho National Engineering Laboratory
. lb/hr pounds per hour
. LOFT Loss-of-Fluid Test Facility
MCL maximum contaminant level
. mrem/yr millirem per year
. NA not applicable
. NCP National Oil and Hazardous Substances Pollution Contingency Plan
. ND non-detect
. NPL National Priorities List
. OU Operable Unit.
. PCE tetrachloroethylene
. pO/I.. picocuries per liter
. PPE personal proteetive equipment
. PWTU Ponable Water Treannent Unit
. RCRA Resource Conservation and Recovery ACt
. RFI RCRA Facility Investigation
. RI remedial investigation
. RIlFS remedial investigation/feasibility studY
. ROD Record of Decision
RWMC Radioactive Waste Management Complex
. SARA Superfund AmendmentS and Reauthorization Act
. TAN Test Area North
. TCE Trichloroethylene
TCLP Toxicity Characteristic Leachate Procedure
. TSF Technical Support Facility
ix
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USGS
VOC
WAG
WERF
WRRTF
~g/gm
~gfL
~g/m3
United States Geological Suri"ey
Volatile Organic Compound
Waste Area Group
Waste Experimental Reduction Facility
Water ReaCtor Research Test Facility
micrograms per gram
micrograms per liter
micrograms per cubic meter
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DECISION SUMMARY
Introduction
-: The idaho National Engineering Laboratory (INEL) was proposed for listing on the National Priorities List
(NPL) on July 14, 1989 (54 Federal Register [FR] 29820). The listing was proposed by the United States
Environmental Protection Agency (EPA) under the authorities granted EPA by the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA) of 1980 as amended by the Superfund Amendments and
Reauthorization Act (SARA) of 1986. The final rule that listed the INEL on the NFL was published on November
21, 1989. in 54 FR 44184.
1. SITE NAME, LOCATION AND DESCRIPTION
The INEL is an 890-square mile Federal facility operated by the United States Deparnnent of Energy (DOE)
(Figure 1-1). The primary missions of the INEL are nuclear reactor technology development and waste management
Current land use at the INEL is classified as industrial and mixed use by the United States Bureau of Land
Management and the INEL has been designated as a National Environmental Research Park. The developed area
within the lNEL is surrounded by a 500 square mile buffer zone used for cattle and sheep grazing. AIIH vestock: are
kept approximately 12 miles away from the Test Area North (TAN) complex. However, wild species such as antelope.
are allowed to roam freely within and across the INEL boundaries. These wild species are prevented from entering
operational areas at the INEL by security fences.
'lCRRETON
l~
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02468 MILES
I I I 1- I
I I I
o 4 8 12 KILOMETERS
Tol_F-
CFA Central Facilities Area
RWMC Radioactive Waste Management Facility
WERF Waste Experimental Reduction Facility
R92 1195
8ig_8U118~
Figure 1-1. Test Area North at the Idaho National Engineering Laboratory.
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Approximately 7,700 people are employed at the INEL, with an estimated 650 employed at the TAN. The
nearest off-site populations are in the cities of: Terreton and Mud Lake (12 miles east); Arco (22 miles west); Blackfoot
(38 miles southeast); Idaho Falls (49 miles east); and Pocatello (67 miles southeast).
The INEL has semidesen characteristics with hot summers and cold winters. Nonnal annual precipitation is
9.1 inches per year, with estimated evapotranspiration rates of 6 to 9 inches per year. Twenty distinctive vegetation
cover types have been identified at the INEL. Big sagebrush. the dominant species. covers approximately 80 percent
of the area. The variety of habitats on the INEL suppon numerous species of reptiles, birds, and mammals. Underlying
the INEL are a series of silicic and basaltic lava tIows and relatively minor amounts of sedimentary interbeds. The
basalts immediately beneath the site are relatively flat and covered with 20 to 30 ft of alluvium. The Snake River Plain
Aquifer underlies the INEL and has been designated a sole source aquifer pursuant to the Safe Drinking Water Act.
The TAN complex is located in the nonhem portion of the INEL and extends over an area of approximately
10 square miles. Access to this area is controlled with fences andsecurlry patrols. TAL~ was built in the early 1950s
to suppon the Aircraft Nuclear Propulsion Program sponsored by the United States Air Force and the Atomic Energy
Commission. The Technical Suppon Facility (TSF) is centrally located within TAN (Figure 1-2), and consists of
several experimental and suppon facilities for conducting research and development activities on reactorperfonnance.
The TSF covers an area of approximately 2,200 ft by 1,500 ft and is surrounded by a security fence. Located inside
of the TSF fence are 38 buildings and 44 associated structures. The TSF-05 injection well is located in the southwest
comer of TSF. Located outside of the fence are parking areas, a helicopter landing pad, rubble piles, a gravel pit,
groundwater monitoring wells, surface drainage wells, and a number of roads.
,...;....,..
T AN-2 production well
TAN-1 production weD
-.~-'
._. -"..
1000 500 0
"'------"---." ~
I "j
TAN disposal pond 7---'------'
. ~lantNorth
1000 2000 3000
.
Scale in feel -<.. ~(S'
~o
TiJ2 0555
Figure 1-2. Facilities at the Test Area North.
2
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Three other major test facilities are located nearby the TSF and are considered part of the TAl"" (Figure 1-2).
These facilities are the Loss-of-FluidTest(LOfT) Facility. the Initial Engine Test (lET) facility, and the Water ReactOr
Research Test Facility (WRRTF).
Most of the INEL is located in the Pioneer Basin. a poorly defined. closed drainage basin. The land surface
at TAN is relatively flat except for volcanic vents (buttes) and unevenly surfaced and fissured basalt lava flows. TAN
lies in a topographic depression between the base of the Lemhi range to the northwest. the Beaverhead Mountains to
the northeast. and the Snake River drainage to the southeast (Figure 1-1). The elevation ranges from a low in this area
of 4774 ft on the Birch Creek playa floor to a high of 5064 ft on top of Circular Butte.
The TAN site is at the terminus of the Big Lost River. downgradient of Birch Creek. and upgradient of the
terminus of the Little Lost River. These rivers drain mountain watersheds existing to the north and northwest of the
INEL. In general. most of the flows from the Big and Little Lost Rivers and Birch Creek are diverted for irrigation
purposes before reaching the INEL. On one occasion in the last 40 years Birch Creek actually flowed into the Birch
Creek Playa and subsequently infiltrated into the ground. During years of high flow, the Little Lost River also flows
on-site. Local rainfall and snowmelt during spring months contributes to recharge of the -Snake River Plain Aquifer
in the vicinity of TAN.
Two production wells supply water for all operations at the TSF. These wells are located in the northeast
corner of the TSF and are identified as TAN-l andTAN-2inFigure 1-2. Sampling of the production wells during 1987
confirmed the presence of trichloroethylene (TCE) in concentrations that exceeded maximum contaminant levels
(MCL). MCLs are standards established by the EP A and are designed to protect human health from the potential
adverse effects of drinking water cont3min3nt~, To protect the workers at TAN. an air sparging system was installed
in the water supply tank at the TSF to ensure that organic contaminant concentrations remain below regulatory levels
(MCLs). '
2. SITE mSTORY AND ENFORCEMENT ACTIONS
2.1 Site History
2.1.1 Disposal History of TSF -05 Injection Well
The TSF-05 injection well was completed in 1953 to a depth of 305 ft. The well has a 12-inch-diameter casing
with perforations from 180 to 244 ft and from 269 to 305 ft below land surface. The well was used to dispose ofTSF
industrial and sanitary wastewaters into the Snake River Plain Aquifer which is encountered approximately 200 ft
below land surface.
Historical records were reviewed and personnel interviews were conducted as part of previous investigations
to determine former waste generation and disposal practices at TAN. These efforts identified siJt facilities that are
potential sources for the groundwater contamination at TAN. Wastes from at least three of these facilities were
apparently disposed in the TSF-OS injection well (Table 2-1). In addition, the TSF-OS injection well was also used
in the late 1950s and early 19605 to dispose of concentrated evaporator sludges from the processing of low-level
radioactive and process wastes at the TSFlntermediate-Level Waste Disposal System (TSF-09). Other types of wastes
believed to have been disposed in the TSF-05 injection well include corrosive waste water. ignitable wastes,
chromium, lead, and mercury.
The TSF-05 injection well was last used as a disposal site in 1972. after which waste waters were diverted to
the southeastern portion of the TAN disposal pond. This well is now securely closed and locked, and the well head
is sealed against surface water intrusion.
3
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Table 2-1. Facilities suspected of using the TSF-05 well for waste disposal.
Shop
Location Function Waste Streama Tune Frame T re:itrnent/S toragelDisposal
T AN-604 Maintenance shop Organics and other chemicals 1956-1972 TSF-05 injection well via
sewage plant
T AN-607 Chemical cleaning Corrosive liquids (acids and 1955-1972 TSF-05 injection well
room (pipe laundry) caustics, but drained separately)
Photo lab and COtTOsive photo developing . 1955-1972 TSF-05 injection well
cold preparation lab solution
a. Accurate disposal and usage records for these materials are not available.
Previous investigations do not provide definitive information on the volumes of organic wastes disposed to
the TSF-05 injection well or the specific processes by which they were generated. However, radioactivity released
to the TSF-OS injection well can be estimated. The Radioactive Waste Management Information System contains
estimates of curies by nuclide released to the TSF-05 injection well for the period of 1971 through August 1972
(Table 2-2. column 2). Records regarding radioactivity released prior to 1971 are not as accurate. Estimates suggest
the total radiation released to the TSF-OS injection well from 19S9 to 1971 was approximately 45 curies (Ci); however
information on the distribution by nuclide during this time period is not available. A rough approximation of nuclide
distribution from 1959 to 1971 was calculated in Table 2-2 (column 3) assuming the same diStribution as known for
1971 through August 1972. and a total release of 45 Ci. -
Potential sources of groundwater contamination at TAN, other than the TSF-05 injection well are not part of
this interim action. These other potential sources win be investigated as part of the Waste Area Group (W AG)~wide
groundwater Remedial InvestigationlFeasibility Study (RJIFS) [Operable Unit (OU) l-07B] or the comprehensive
WAG 1 RIlFS (OU 1-10).
2.1.2 Previous Groundwater Investigations
Contaminants in the TAN groundwater were first detected in April 1987. During groundwater sampling
activities, TeE was detected in a sample collected for volatile organic compound (VOC) analyses from TSF
production well TAN-I. Subsequent sampling of both production wells (T AN-I and T AN-2 in Figure 1-2) for VOCs
during September and November 1987 confirmed the presence of TeE in both wells and also identified
tetrachIoroethyl~ (PeE) in well T AN-t. In addition. independent groundwater sampling at TAN was performed by
the USGS in 1987 and 1988. Results from these investigations indicate that well TSF-OS and a nearby observation
well (USGS-24, Figure 5-3) were contaminated with TCE and PCE at concentrations in excess ofMCLs. Samples
from well TSF-QS and the two production wells (TAN-} andT AN-2) were also tested forseleetedradionuclides during
these sampling efforts. Tritium and Sttontium-90 were detected at concentrations in excess ofMCLs in samples from
well TSF-QS. Cesium-137. cobaIt-60, americium-241, and plutonium were also detected in well TSF-05; however,
there are no MCLs for these analytes.
On the basis of the results from these early sampling efforts. a Resource Conservation and Recovery Act
(RCRA) Corrective Action Program was developed to addresS groundwater contamination at TAN. One of the first
actions initiated was the installation of an air sparger in the water supply system in 1989 to keep organic contaminant
..
,
I'
1
-------
Table 2-2. Curies released to the TSF-05 injection well (by nuclide) (1959 through AuguSt 1972).
Nuclide Reponed Curies Released Estimated Curies Released Estimated Total Curies Released
(1971 and 1972) (1959-1970) ~ . ,. ." . . 1"f'>';.
Cesium-134 4.6 x 10-3 2.4 x 10-2 2.9 x 10-2
Cesium-137 2.2 x 10-2 1.2 x 10-1 1.4 x 10-1
Strontium-90 8.6 x 10-3 4.6 x 10-2 5.4 x 10-2
Tritium 8.5 44.7 53.2
Unidentified alpha 1.0 x 10-3 5.5 x 10-3 6.6 x 10-3
Unidentified beta
and gamma 8.5 x 10-3 4.5 x 10-2 5.4 x 10-2
Yttrium-90 8.6 x 10-3 4.6 x 10-2 5.4 x 10-2
Total 8.5 44.9 53.5
concentrations below safe drinking water levels.
A well drilling and groundwater sampling program from 1989 to 1990. was also initiated which included
drilling and sampling 17 new wells (see Figure 5-3), plus sampling another 12 existing wells within 4 miles of the
injection well. Additional samJ2.~ng of production wells, new and existing monitoring wells. and the TSF-05 injection
well for organic, inorganic, and radiological constituents occurred during 1989 and 1990 (See Table 5-1 and Figure
5-3). During this sampling period. four contaminants-TCE, PCE. lead, and strontium-90-were consistently
detected in more than one well at concentrations exceeding MCLs. These four contaminants are referred (0 as
contaminants of concern. and are the focus of this interim' action. Ranges of detected concentrations for the
contaminants of concern in the TAN groundwater are presented in Table 2-3.
The USGS also sampled selected new and existing wells for organic and radionuclide constituents in 1989.
Analytical results for TeE an~ from this sampling effort were similar to those presented in Table 5-1, and
discussed above. Concentrations of these compounds exceeded MCLs in all wells sampled. with the highest
concentrations found in well TSF-05. Tritium concentrations exceeded the MCL in well TSF-05. but were less than
the MCL in the other wells sampled. Concentrations of Strontium-90 exceeded the MCL in the TSF-OS injection well
and a nearby well (T AN- D2). Eevated concentrations of Cesium-137 were also found in the TSF-05 injection well.
Another action, initiated in 1990, removed and anaIyzedcontaminated sludge that had accumulated in the lower
S5 ft of the TSF-OS injection well. Moderate to high concentrations of radionuclides and organic compounds were
detected in the sludge. (Table 5-3).
On the basis of the results of the groundwater sampling described above, and from analytical and radiological
sampling results of sludge removed from the, TSF-05 injection well in 1990 (see Section 5-3). the TSF-05 injection
well was determined to be a priiriary source of groundwater contaminants at TAN.
5
. .-...~~...
. . -'-~'... :".,.
-------
Table 2-3. Concentration of Groundwater Contaminants of Concern
Contaminants
Concentrationa
Maximum Contaminant Levels
Trichloroethylene
Tetrachloroethylene
Lead
Strontium-90
2 to 1,300 Jlg/L
2 to 71 ~g/L
3 to 515 ~g/L
2 to 470 pCi/L
5~g/L
5~g/L
50Jlg/L
8 pCi/L
a. Data obtained from sampling a network of 30 wells in the TAN area during late 1989 and 1990. Most of these
wells are within I mile of the TSF-05 injection well (See Table 5-1 for specific sampling results and Figure 5-3
for well locations). Data obtained from OU 1-07B RIlFS Work Plan. EGG-WM-9098, May 1992. .
2.2 Enforcement
A Consent Order/Compliance Agreement (COCA) was entered into between DOE and EP A pursuant to RCRA
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 INEL, and resulted in the RCRA Corrective Action Program mentioned in the
preceding section.
As a result of the INEL' s listing on the NFL in November 1989, DOE, EP A. and the State of Idaho Department
of Health and Welfare (IDHW) entered into a Federal Facility Agreement and Consent Order (FF AlCO) pursuant to
CERCLAinDecember 1991. TheFFAlCO superseded the COCA and established a procedural framework for agency
coordination and a schedule for all CERCLA and RCRA corrective action activities conducted at the INEL. This
interim action is undertaken in accordance with this FFAICO.
3. HIGHLIGHTS OF COMMUNITY PARTICIPATION
3.1 Community Relations Prior to the Interim Action
In accordance with CERCLA sections 113(K)(2)(b )(i-v) and 117, community interviews were conducted with
local officials, community residents, and public interest groups to solicit concerns and information needs, and to learn
how and when citizens would like to be involved in the CERCLA process. The information gathered during
community interviews and other relevant information provided the basis for development of the INEL-wide
Community Relations Plan (CRP). This INEL-wide CRP will continue to be implemented during this interim action
to reflect the decision-making process under CERCLA and the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP), and to ensure that appropriate public participation continues under the FFAICO.
The presence of organic compounds in the groundwater at the TAN was first announced in a news release issued
in November 1987. A second news release issued in September 1988, announced both the provision of an alternate
source of drinking water for workers at TAN, and the scheduled inst.a11ation of an air sparging system to remove volatile
organic contaminants from the drinking water supply at TAN.
6
-------
" 3.2 Community Relations to Suppbrt Selection of a Remedy
In accordance with CERCLA sections 113(K)(2)(b)(i-v) and 117. the public was given the opportunity ro
participate in the remedy.selection process.
The Notice of Availability for the Proposed Plan was published January 5. 1992. in the following newspapers:
The Post Register (Idaho Falls).
The Idaho State Journal (Pocatello),
Twin Falls Times News,
Idaho Statesman (Boise),
The Lewiston Morning Tribune.
Idaho Free Press (Nampa),
South Idaho Press (Burley),
Moscow-Pullman Daily News.
.
.
.
.
.
A similar newspaper advertisement was published January 30, 1992, in
The Post Register (Idaho Falls),
The Idaho State Journal (Pocatello),
Twin Falls Times News,
Idaho Statesman ]oise).
Idaho Free Press (Nampa),
the South Idaho Press (Burley).
.
.
These advertisements repeated the public meeting locations and times. Personal phone calls were made to
inform individuals and groups about the comment opportunity. A "Dear Citizen" letter transmitting a copy of the
Proposed Plan was mailed January 8, 1992 via a mailing list of 5.731 names of groups and individuals.
The public comment period was initially scheduled from January 13, 1992, to February 12,1992. Threepublic
meetings were held on February 4,5, and 6, 1992, in Idaho Falls. Boise, and Burley. Representatives from the DOE,
EPA, IDHW, and EG&G Idaho, Inc., were present at the public meetings to discuss the Proposed Plan, answer
questions, and receive both written and oral public comments. For one hour prior"to each meeting, INEL, EP A, and
IDHW representatives were also available for informal discussions with the interested public. A court reporter was
present at each meeting to record. verbatim, the proceedings of the meetings. Copies of the transcripts from the public
meetings are available for public review in the Information Repositories (which are located at the public libraries in
Boise, Twin Falls. PocateUo, Idaho Falls and the University ofldaho library in Moscow) as part of the Administrative
Record for this interim action.
A request for an extension of the public comment period was received and granted, therefore extending the
comment period to March 13, 1992. A notice of the extension was published February 18 and 19, 1992, in:
. The Post Register,
. The Idaho State Journal,
. Twin Falls Times News,
. Idaho Statesman,
The Lewiston Morning Tribune,
Idaho Free Press,
South Idaho Press, and
Moscow-Pullman Daily News.
.
.
-------
On March 9, 1992, a technical briefing was conducted with the League of Woman Voters of Moscow via a
conference call.
A Responsiveness Summary has been prepared to address public comments as part of this Record of Decision
(ROD). All verbal comments giyen at the public meetings and all submitted written comments are repeated. verbatim.
in the Administrative Record for me ROD. Those comments are annotated to indicate which response in the
Responsiveness Summary addresses each comment.
In accordance with CERCLA section 113 (K)( 1), an Administrative Record was established to provide the basis
for selection of the remedial action. The Administrative Record is available for public review at the INEL technical
library in Idaho Falls. Copies of the Administrative Record are available for public review at the public libraries at
Boise, Idaho Falls, Pocatello, and Twin Falls, and the University of Idaho Library in Moscow.
Persons on the mailing list will receive a notice of availability stating that the signed ROD is available. Copies
of the ROD and the Responsiveness Summary wi1l be placed in the Administrative Record and in the information
repositories, and will be provided to the public upon request.
4. SCOPE AND ROLE OF THE OPERABLE UNIT
The INEL is divided into ten WAGs. The TAN has been designated as WAG 1, which is further divided into
ten OUs. The TSF-05 injection well and surrounding groundwater contamination are one of the TAN OUs. It may
be appropriate to implement an interim action for an OU before completing the RIIFS. Because sufficient data have
been colleCted regarding the TSF-05 injection well, the OU was further subdiviQed into au 1-07 A (interim action)
and OU 1-07B (TAN' groundwater RIlFS).
au 1;.07 A, the subject of this ROD, addresses the groundwater contaminants near the TSF-OS injection well.
Thus, this interim action will help prevent further degradation of groundwater while the au l-07B RIlFS is being
completed. During Remedial Design, the engineering phase that follows this ROD, technical drawings and
specifications wiU be developed for the implementation of this interim remedial action.
To the extent practicable, this interim action will facilitate the au l-07B RllFS by providing information about
aquifer parameters based on data from the groundwater ex.traction and monitoring wells. In addition, this interim
action will provide site-specific performance information that can be used for evaluating alternative technologies,
determining process sizing, and estimating costs. Because this interim action is not the final remedy for the TSF-05
injection well and surrounding groundwater, subsequent investigations are planned to fully address the potential
threats posed by the conditions at the site. This interim action will not be inconsistent with nor preclude the
implementation of the final response action scheduled to be determined in 1994. In the event that continued operation
of this limited scope remedy is determined to be appropriate. operational parameters will be defined in the au 1-07B
ROD.
S. SUMMARY OF SITE CHARACfERISTICS
5.1 Geology
The geology of TAN is characterized by a relatively thin layer (0 to 50 ft) oflacustrine sediments and playa
deposits consisting of silts. clays. and minor sands. Underlying the surficial sediments is a thick sequence of basalt
flows with sedimentary interbeds. The basalts exhibit a wide range oflithologic textures and structures; from dense
to highly vesicular basalt and from massive to highly fractured basalt. Individual flow units consist of a fractured!
-------
8
B'
TSF FoQiIy
w_-
-
T_FICIiiIy
-
4700
'i
i -
i
:i
e
. -
~
.
.
=-
c -
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..
..
-
-
AHPI
TSF~
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Qi.
~OFT' eFE'n 0... ':'JoN 0....3 ~, - ~ 2 TAN'. GinS
~.:-:;-: - .....' --. " ',' '. . :;:~;":<~.~:~:~~::; "" -'"...'::: ~:S:
...- :. :.':'~:r:"~':'~..7 . """-'.. ,..
- .;.
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- I~ -.z.;;.-:. ~ " .
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H W_- &-'",17
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- -. ."'" -: ..:':
"'" 1
-~-:-.~... _Ga Iftt8ID8d "
""-~::.=~~...,.-
--':=:=..:::."'~~~#,;~ 7
~ ::':z:::'~:-:::;. 1
k;..;:..-~! ~ Cloyd m _or~- -===--=~"'":":""l
. ~ s.. - grawI I ~-
C=:J a- 0 CpM- !
- Hift9I8 - at aI_-
V8fticM~"'1" J~ ~10:1
'000 ~ '000 2000
I i -m 0C1
-(tMq
Figure 5-1. Hydrogeological profile of the Test Area North.
J J \ "".' ~,. ." ,0." , !' :- ..".' I.~W " .~ ;.-
f;i~~~7;Tff~~:/~Z~:-~~?~7J
. ,.,l.NP~ '., ". :1 ,!.~. '.,J';~" 'I : LJ :
."'8~~ J~~~i 1.'L/(' ":.i=..,,::;;'--!-":i.-~.>:\t~",...;. l' f \
:.,.. :=~~~'I ?!," ;~~ ..;.. I' I,~.\ -~-..;,. ,.; 'f .
II ~'... ":"~"'..1~9J.~ /\ ". ;;--...;:.......~.:r<"I'~ .,/ -'j. IJ~'
')0.,. r-""\\v:~'~...::~..~~' \. ".~ . -71'1 \ /' q ...",,' . f :0::
i ;ij-;t\!~: "'i-'~~=r..jisC\ .:. "'1':;I'.\r~.-,:.~""'../ 'i
~ijo';~? ~..'-.-,' / i'I;"" I " .J:
!' :",':::--'; ~:'N~iSCi.tj "j 1/. '1 ,-
I \~ i o;.~~{/;. ~ ,~j..I'J
:0 : .. .' ~""",/.\I.-~/... :0 ; ,,' (.
\ : -' .. "-."',4-'1 rs-' ot : / ~
'.... : rs:.os 1r1jec:"'..cn Well""~: ~ .- , . ! 1",'$
>~~~r~..."'\: j'1,j !;' '\.";)1 :)~,
.~ ""~~',-'~ '-J_";' . '.J C;2' '9 ~:. : ~--- '~I
--:::4,~t. ~...~ !-.- ;'.'" VJ'/.i~'.j '--. -1":,;. ~- . ;.._~' -.":-:,..';
~ 7"-' i:.-~... ' " it.- ... . '-~'Q 1{./:I'1.~.;'\~"A
~,.,,!\: . ......,..~\ ~-4:~'i ,-- "";~ \ -'.,' .'" ..\~~~'~
""" ! \1 :-~~..: ,~:; ! I' \ ....~;:--;., I ,"",~-:i
:zo",,': ?.. --~y' !...i5. ~' j .. i \-,'/01- ~,... "', r' t"'~
::.!. .,,,->...--- I ~..: \.; , ; t"S' ',~ ... ~ ,,;"" .""7".3t:t'~~A
- . :~...~~: --'j""', . . X . ... .. :, ,. { '\. :~.~..i:~.~::t~(;:1
.....;.e,...,=--------- .-" .' ~ . '0. .1 -- I~''':.~'. ...~~
- :~. '0"'" r;../ " -I. ) """~\Ji:?'~:'d
'. '::,. ~~j;;\~:'I'~.q~-'::~ "'1, '~"'.,.:::.:-:O ""['~-:--;."J::II;;/:';: ;.:~_~~d;~~
~.~:.:'... I10jO-:"""W~'1 i..-." -'..' I " ~~~/_~':~
. = ..~.~:~-,,-v.!o;:.~~1..~:.:;~~'!.,lta_.c.f.'.,"1. ~ ~".':.j......._-,. ',:-",.~.~~.:4Y '-:;~,~-.~
f . . . '1..., ....f .~-. "-'?-:,' ,~.. -"...., --:: .." I
1'~::~:,tw-~~~!~a0~':t~/-,
Figure 5-2. Plan view of Test Area North showing the location of cross-section B-B'.
-------
rubbly flow top. a midcDe dense basalt, and a fracturedlrubbly flow bottom. These flow units have a thickness of
approximately 15 ft. Sedimentary interbeds occur within the basalt and consist of clay or silt. Interbeds thar have been
encountered to the maximum depth drilled include the P-Q and Q-R interbeds. Figure 5-1 is a cross-section through
TAN. The location of the cross-section is shown in Figure 5-2. The P-Q interbed is discontinuous. The deeper
interbed, Q-R, is interpreted to be continuous and slopes to the southeast. It has a variable thickness with a median
thickness of approximately 4 ft. Interpretation of hydraulic head data indicates thatthisinterbed could be a continuous,
semi-confining layer. Both interbeds and the impact of the TAN geology on remedial alternatives will be evaluated
in more detail in the au 1-07B RIlFS.
5.2 Hydrogeology
The water table underneath the TSF facility averages about 4583 ft above mean sea level [at well United States
Geological Survey (USGS)-24] or about 213 ft below land surface with a seasonal variation of about 4 ft. The water
table also has a relatively flat horizontal hydraulic gradient (l ft/mile). In general, the depth to groundwater
immediately beneath the land surface at TAN is approximately 200 to 220 ft. The aquifer thickness could be greater
than 900 ft. The groundwater flow velocity in the vicinity of TAN is generally south-southeast, and flow velocities
range from 0.003 ft/day to 6.0 ft/day, with a median velocity of approximately 0.3 ftJday. Transmissivity estimates
range from 400 to 800,000 ft2/day, with a median transmissivity of approximately 38,000 ft2/day.
The au 1-07B RIlFS is investigating whether the Q-R interbed is continuous and creates semi-confining
conditions.
Groundwater flow in the vicinity ofT AN is south-southeasterly (Figure 5- 3) and is influenced by groundwater
recharge from the north, northwest, and northeast. Also, the local groundwater flow beneath TAN is affected by
pumping from the TSF production wells northeast of the injection well.
T... ArM North
IIovIM
--
\ ~\.,)\
Figure 5-3. Groundwater monitoring wells at the Test Area North.
TI2OS"
-------
5.3 Nature and Extent of Contamination
Although there may be other sources. past waste disposal in the TSF-05 injection well is considered to be the
principal source of groundwater contamination at TAN. In general, the highest contaminant concentrations were
detected in samples from well TSF-05 (Tables 5-1 and 5-2). TCE concentrations ranging from 24.000 ~g/L to 35,000
~g/L were detected in groundwater samples collected from the TSF-05 well during 1987 through 1989. Then. in
January and February 1990. sludge was removed from the lower 55 linear ft of this well. The sludge was analyzed
for total metals. total organics. radionuclides. and Toxicity Characteristic Leachate Procedure (TCLP) metals.
organics. pesticides. and herbicides. The concentrations of contaminants detected are presented in Table 5- 3. On the
basis of the high concentrations of organic and radiological constituents detected in the sludge. this material was
considered to be a major source of groundwater contamination in the TSF-05 injection well and the surrounding
groundwater. Although there are no additional data at this time. contaminant concentrations in the TSF-05 well are
expected to have declined since the sludge was removed. Groundwater sampling associated with the interim action
and the au l-07B RI/FS will determine current contaminant concentrations in the TSF-05 injection well and other
wells at TAN. Also. potential sources of groundwater contamination at TAN other than the TSF-05 injection well will
be evaluated under the au 1-07B RI/FS.
Preliminary interpretations regarding the extent of contamination at TAN are summarized below. These
interpretations are based on the previous sampling results presented in Tables 5-1 and 5-2. and will be funher evaluated
(with new sampling data) as part of the au 1-07B RI/FS. A groundwater contaminant plume extends generally
southeastward from the TSF-05 injection well. which is consistent with the main direction of groundwater flow
beneath TAN. Some contaminants have also been detected northeast of well TSF-05; contaminant migration in this
direction is probably caused by localized shifts in groundwater flow directions resulting from pumping the TAN
production wells (TAN-l and TAN-2). As stated previously. the contaminants of concern for the interim action
include TCE. PeE. lead. and strontium-9O. These foin" contaminants have been detected at varying distances from the
TSF-05 injection well, apparently reflecting differing rates of migration through the groundwater. TCE is the most
widespread constituent in the contaminant plume, having been found above MCLs as far as 1.5 miles southeast of the
TSF-05 well. PCE has been detected in wells as far as 1 mile southeast of the TSF-05 well. Concentrations of
strontium-9O and lead above their respective MCLs have only been regularly detected within 1/2 mile of the TSF-05
well.
The vertical extent of groundwater contamination at TAN is not yet clearly defined. Most wells at TAN are
screened or open across the water table (which occurs at depths of approximately 200 ft or 4590 ft above mean sea
level). The contaminant plume was detected primarily from groundwater samples collected from these wells. The
deepest detected contamination was found in a sample from well T AN-12, which is screened at a depth of 362 to 382
ft; approximately 165 ft below the water table at an elevation of 4420 ft above mean sea level. However, there are
relatively few wells at TAN which are screened only across deep intervals. Therefore, the vertical extent of
contamination is largely unknown. There is no information. for example, to indicate whether contaminants have
migrated below the Q-R interbed (Figure 5 -1), which is interpreted to be asemi-confming bed beneath TAN. New
wells will be installed as a part of the au I-07B RIIFS to help better define the vertical extent of the contaminant plume.
On the basis of the previous sampling data presented in Table 5-1 and discussed above, the contaminant plume
beneath TAN is estimated to be approximately 1.5 miles in length, 0.5 miles in width. and 200 ft thick. Although there
are numerous uncertainties associated with this estimate (particularly regarding the plume thickness). it is a sufficient
initial characterization for interim action design purposes. As stated above, subsequent groundwater sampling for the
interim action and the au l-07B RIlFS will further refme this initial characterization.
-------
Table 5-1. Groundwater monitoring welJ data.
I Well mime ANP-06a ANP-08 ANP.Q9a FET -02 IET -06 TAN-OI
Screened interval. 230-250 232-304 240-260 215-230 220-240 200-350
it below land surface
Distance from TSF.05. ft 10.630 I 8420 16.210 4340 6460 2320
When sampJe.dD NIYIY NIYIY NIYIY I NIYIY YIYIY NIY/Y
Contaminant. 11g!L I
Acetone I
Benzene 18JNDIND
2-Butanone
Carbon Disulfide 2/NDIND
Carbon Tetrachloride
Chloroform
Chloromethane ..
Dibromochloromethane
1.1 Dichloroethane
1.1 Dichloroethylene
1.2 Dicbloroethane NA/SIND
1.2 Dichloroethy1ene (total)
Methylene Chloride
Tetr.u:bloroethy1ene NA/2/3 NA/2/3
Toluene
1.1.1 Trichloroethane
Trichloroethylene NA/6n NAnI8
Vinyl Chloride
Barium
Chromium NA/11I17
Lead NAlNDn NAIND/15 81ND/lO
Mercury
Gamma, pCiIL NAINDIND
Strontium-90. pCiIL NAIND/2 NAINDIND NA/412
Tritium. pCiIL NAINDIND NA/NDI240
Note: FIrst value given is from March 1989 groundwater monitoring well sampling. Second is from November 1989,
and the third is from November 1990. ND is non-detect. NA means a sample wasn't taken from that well in that
sampling event If no data are given. the contaminant has not been detected in that well during the listed sampling
events.
a. Wells ANP-06 and ANP-09 are not shown on Figure 5-3. ANP-06 is 10,630 feet northwest of TSF-05. AJW-09
is 16,210 ft southeast of TSF-05.
.
b. Indicates when each well was satnpled (Le. Y IY fY means the well was sampled in March 1989, November 1989,
and November 1990).
-------
Table 5-1. (continued).
Well name T AN-02 TAN-03 T AN-04 T AN-05 T AN-06 TAN-07
Screened interval. 235-335 230-235 235-240 280-285 235-255 298-318
ft below land surface
Distance from TSF-05. ft 1930 2340 1410 1380 4990 .5000
When sampledb NIY/Y N/Y/Y NIYIY NIYIY NINIY NIN/Y
Contaminant.j.lglL
Acetone I NAI72/ND
Benzene
2-Butanone NA/6/ND
Carbon Disulfide
Carbon Tetrachloride
Chloroform
Chloromethane
Dibromocblorometbane
1.1 Dichloroetbane
1.1 Dichloroetbylene
1.2 Dichloroethane
1.2 Dichloroethylene (total)
Methyl~ne Chloride
Tetrachloroethylene NAI20/24 NA/16/28
Toluene
1.1,1 Tricbloroethane NAI3f3 NAlNDI2
Trichloroethylene NAI3I2 NAnOm NAI711100
Vinyl Chloride
Barium
Cbromium NA/I01ND
Lead NA/80IS NA/21/ND NAlND/15
Mercury NAISIND NAlNDIO.3
Gamma. pCiIL
Strontium-90, pCiII... NA/4INA NAlNDI6 NAINA/13 NAINA/l
Tritium. pCiIL NAI900I NA/1700/
1000 lloo
Note: FIrst value given is from March 1989 groundwater monitoring well sampling. Second is from November 1989.
and the third is from November 1990. ND is non-detect. NA means a sample wasn't taken from that well in that
sampling event. If no data are given. the contaminant has not been deteCted in that well during the listed sampling
events.
b. Indicates when each well was sampled (Le. YIYIY means the well was sampled in March 1989, November 1989.
and November 1990).
-------
Table 5-1. (continued).
Well name TAN-08 T AN-09 TAN-lO TAN-lOA TAN-ll TAN-12
Screened interval. 232-304 290-295 220-225 215-250 260-265 362-382
ft below land surface
Distance from TSF-OS. ft 2180 90 210 180 250 290
When sampledb NIY IY NIY IY NIYIN NIY IY NIYIY NIYIY
Contaminant. IlglL I
Acetone NA/611ND
Benzene
2-Butanone
Carbon Disulfide
Carbon Tetrachloride NA/6INA
Chloroform
Chloromethane NA/NA/l
Dibromocbloromethane
1,1 Dicbloroethane
1.1 Dicbloroethylene
1,2 Dicbloroethane
1,2 Dich1oroethylene (total) NAlNDI2
Methylene Chloride
Tetrachloroethylene NA/17/20 NA/lllNA NAI7/6 NA/27J21 NAINA/13
Toluene NA/IIND . NA/IJNA
1,1.1 Trichloroethane NA/lINA
Trichloroethylene NA/8619O NA/28/NA NA/261l8 NA/89n5 NAINA/39
Vinyl Chloride
Barium NA/2701303 NA/238JNA NAINA/238
Chromium
Lead NAlND128 NA/4IlO NA/8/NA NAINA/15 NA/SIND
Mercury
Gamma, pCiIL
Strontium-90. pCiIL NAlNDJlO NAllS127 NAn6INA NAINA/470 NA/6f3
Tritium, pCiIL NAI8000J NAI2800J NAINA/ NMSOOI NAINA/
6900 NA 3600 3300 1800
Note: First value given is from March 1989 groundwater monitoring well sampling. Second is from November 1989,
and the third is from November 1990. ND is non-detect. NA means a sample wasn't taken from that well in that
sampling event. If no data are given, the contaminant has not been detected in that well during the listed sampling
events.
b. Indicates when each well was sampled (Le. Y fY fY means the well was sampled in March 1989, November 1989,
and November 1990).
-------
Table 5-1. (continued).
Well name TA.'I/-13A TAN-14 TAN-IS TAN-16 TAN-I7 TAN-DI TAN-D2
Sa-eened interval. 216-236 376-396 232-252 302-322 320-340 230-235 230-235
ft below land surface
Distance from TSF-OS ft 1370 1420 ~no 5750 2200 1940 11~
When sanwledb ~/NIY N/NIY N/NIY ~INIY N/NIY YIYIY YIYIY
Contaminant. J!8/L
Acetone 6/ND1ND
Be nune
2-Butanone
Carbon Disulfide 3/NDIND
Carbon Tettacbloride
01l0r0fonn
Cbloromethane
Dibromocbloromethane NO/SIND
1.1 Dichloroethane
1.1 Dichloroethylene
1,2 Dichloroethane
1,2 Dicbloroethylene (total) ND/2/2 N0185/14
Methylene OIJoride
T etrachloroethylene NAlNA18 NAINA/9 6/23/19 IIYIlI8
Toluene NAINA/l
1.1.1 Trichloroethane
Trichloroethylene NAINA/32 NAINA/41 39/150/140 17016601240
Vinyl Chloride
Barium NAINA/2oo 286f3121280
Cbromium NAINA/20 NAINA/21 NAINA/12 NAINA/45
Lead NAINA/13 NAINA/18 71ND/1l I lYSIS 15
Menmy
Gamma. pCiJL NAINDIND NAINDIND
Strolltium-90. pCiIL NAINA/2 NAINA/5 NAINA/13 NAINA/20 NAINDIND NA/230129
Tritium, pCiIL NAIN A/330 NAINA/320 NA/20001 NA/44OOI
1900 3100
Note: First value given is from March 1989 groundwater monitoring well sampling. Second is from November 1989,
and the third is from November 1990. ND is non-detect. NA means a sample wasn't taken from that well in that
sampling event. If no data are given, the contaminant has not been detected in that well during the listed sampling
events.
b. Indicates when each well was sampled (Le.. YIY/y means the well was sampled in March 1989, November 1989.
and November 1990). .
15
-------
Table 5-1. (continued).
Well n~me TA.N-D3 USGS-24 USGS-26 GIN-2 GIN-4 TSF-OSa
Screened interval. 230-235 240-245 205-260 I 230-240 -.
it below land surface
Distance from TSF-05 ft 3160 1410 14970 7700 7680
When samDledb NIYIY YIYfY NIY IY NINIY NINIY YININ
Contaminant. j.l.glL I
Acetone 18INDIND
Benzene 4/NA/NA
2-Butanone
Carbon Disulfide
Carbon Tettachloride
Chloroform ND/lIND
Chloromethane
Dibromoch1oromethane
1,1 Dichloroethane ND/2/1
1,1 Dichloroethylene NDl9n 23INAINA
1.2 Dichloroethane
1,2 Dichloroethylene (total) 4/44147 78OO1NA/NA
Methylene Chloride
Tettachloroethylene 19n1l51 NA/NA/2 NAlNAll S3INAINA
Toluene NA/6IND
1.1,1 Trichloroethane ND/I211 1
Trichloroethylene 210/1300n20 NA/NA/3 NAINA/2 28000INAINA
Vinyl Chloride 2SINAINA
Barium 2011204/220 148/NAINA
Chromium
Lead NAn/5 9/1418 NAINA/44 14/NAINA
Mercury 03/NAINA
Gamma, pCiIL NAINDIND NA/NAINA
Strontium-90, pCi/L NAIND/l1 NA/NAINA
Tritium, pCiIL NAI980018300 NA/NAINA
. .
Note: rIrst value given is from March 1989 groundwater monitoring well sampling. Second is from November 1989.
and the third is from November 1990. ND is non-detect. NA means a sample wasn't taken from that well in that
sampling event. If no data are given, the contaminant has not been detected in that well during the listed sampling
events.
. a. The data given for the TSF-05 well represent groundwater conditions near the well in March 1989 before the
sludge was removed from the bottom of the well in January and February 1990.
b. Indicates when each well was sampled (i.e. Y IY /Y means the well was sampled in March 1989, November 1989.
and November 1990).
-------
Table 5-2. Maximum detected concentrations of contaminants detected by the USGS in groundwater samples
at TAN 1987-1989.
Well ID Anal yre Maximum Detected Concemration
(~gIL)
TSF-05 TCE 35.000
TSF-05 PeE 170
(pCi/L)
TSF-05 Sttontium-90 1.930 +/- 50
TSF-05 Tritium 43.200 +/- 1,000
TSF-05 Cesium-137 7,500 +/- 200
TSF-05 PIutonium-238 1.22 +/-.09
TSF-05 PIutonium-239, -240 5 +/-.2
TSF-05 Cobalt-60 890 +/- 90
TSF-05 Americium -241 0.21 +/-.04
These data represent conditions before sludge was removed from the well (refer to Section 2.1.2).
5.4 TAN Disposal Pond Data
The TAN disposal pond is an unlined, diked area built in 1972 that encompasses approximately 35 acres.
Access to the entire 35 acre pond is restricted by a fence. Approximately 4 acres in the nortQeast and eastern edges
of the large disposal pond are currently in use. The remaining 31 acres are inactive (dry) and have apparently never
been used for any disposal operations. Review of historical records and aerial photographs, interviews with former
employees, and a site inspection provided no evidence of former discharges or other waste disposal operations in this
31 acres of the pond. Therefore, this part of the disposal pond is considered to be uncontaminated.
The active area of the pond consists of two lagoons-a main lagoon and an overflow lagoon-which recei ve
approximately 40,000 to 70,000 gallons per day (gpd) of process waste water and treated sewage effluent. The main
lagoon and the overflow lagoon are located along the eastern and northeastern edges of the disposal pond, respectively.
Both of the lagoons are bermed to contain the discharge eftluent within these portions of the large disposal pond. Some
soil contamination, resulting from past activities at TAN, has been detected in the lagoons and immediate vicinity.
Detected contaminantS include organic compounds, radionuclides, and heavy metals. Contaminant concentrations are
highest in the upper soil layers and typically decrease with depth. In general, the highest concentrations and frequency
of detection were found in the main discharge lagoon. A perched water zone exists in the vicinity of the active lagoons
and was routinely monitored by sampling two monitoring wells located along the northeastern and eastern edges of
the 35 acre disposal pond. No contaminants have been routinely detected above MCLs in samples from these wells.
In summary, on the basis of the above information, most of the 35 acre disposal pond is considered to be
uncontaminated. Some soil contamination is associated with the active lagoons along the northeastern and eastern
edges of the disposal pond. However, this contamination is localized in the upper soil layers in and adjacent to the
acti ve lagoons and does not appear to be migrating [0 other portions of the large disposal pond The nature and extent
of existing contamination in the TAN disposal pond will be further evaluated under au 1-06 of the FFNCO.
-------
Table 5-3. Maximum contaminant concentration in TSF-05 injection well sludge. a
.. ,,''''
Substance Concentration (with units)
1.1 dichloroethylene 24 ~g/gmC
Methylene chloride 290 ~gJlb
trans-l,2-dichloroethylene 410 ~gIgmC
Trichloroethylene ; ~O,~ ~gIgmC
Tetrachloroethylene 2,800 ~g/gmC
2-butanone (Methyl Ethyl Ketone) 180 ~g/gm
Barium (total) 326 ~g/gm
Lead (total) 180 ~g/gm
Chromium (total) 91 ~g/gm
Mercury (total) 101 J.l.g/gm
Gross betad ',-" 4,900,000 pCi/L e
.-",:
Gross alphad 6,000 pCi/L e
Cobalt-60 812 pCilgm
Cesium-137 2,540 pCilgm
Europium-l54 ~~.. 6.6 pCilgm
Americium-241 23.6 pCi/gm
Tritium 1,000,000 pCi/Le
Plutonium- 239 12.2 pCi/gm
a. Data were taken from the au 1-078 TAN groundwater RI/FS workplan. Appendix B and Appendix G.
b. TCLP extraction results for leachable Yacs.
c. Total YQCs.
d. The percentage of gross beta which is strontium-90 has not been determined.
e. These samples were obtained from water decanted or liquid extracted from the sludge.
18
..-.. '-'---".----...-.....'
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6. SUMMARY OF SITE RISKS
6.1 Human Health
.... ~.... . . .
Although this interim action does not use a completed baseline risk assessment, sufficient infonnation is
available to demonstrate the potential for risk and the need to take action.
Chemical-specific standards that define acceptable risk levels such as MCLs, may be used to determine
whether an exposure is associated with an unacceptable risk to human health or the environment and whether remedial
action is warranted. Four contaminants have been found to exceed their chemical-specific MCLs in more than one
well and on a recurring basis in the vicinity of the TSF-05 injection well and therefore are considered to be contaminants
of concern. Table 6-1 identifies the contaminants of concern. their respective MCLs, and risk-based concentrations.
Both trichloroethylene and tetrachloroethylene have been shown to cause cancer in laboratory animals such
as rats and mice when the animals are exposed at high levels over their lifetimes. Chemicals that cause cancer in
laboratory animals also may increase the risk of cancer in humans who are exposed at lower levels over long periods
of time.
Lead can cause a variety of adverse health effects in humans. At relati vel y low levels of exposure, these effects
may include interference with red blood cell chemistry, delays in normal physical and mental development in babies
and young children. slight deficits in the attentiOn span, hearing, learning abilities of children, and slight increases in
the blood pressure of some adults.
Strontium-90 is a fission product and a beta particle emitter. Strontium-90 accumulates in bone tissue and if
taken internally, can damage the bone marrow and bone tissue which can cause cancer. Children are more suscepti ble
to impacts from the strontium-90 because their bones are developing more rapidly than in an adult. Beta particles can
penetrate the skin, so these particles can also damage the skin and eyes.
The potentially exposed populations include site workers and site visitors. The reasonable exposure pathways
for each group are ingestion of contaminated groundwater and inhalation of volatiles. The immediate threat of
exposure has been mitigated by the installation of an air sparger system in the drinking water supply. Although the
air sparger reduces the risk of exposure, it does not address the source of groundwater contamination or the protection
of future drinking water supplies. For a future residential scenario where people might live on part of the INEL, a
drinking water well could draw contamination from a portion of the contaminant plume.
Actual or threatened releases of hazardous substances from this site, if not addressed by implementing this
interim action selected in this ROD, may present an imminent and substantial endangerment to public health, welfare.
or the environment.
A quantitative human health risk assessment will be included as part of au l-07B RIIFS.
6.2 Ecological Risk Assessment
An ecological risk assessment was not perfonned for this interim action. A quantitative ecological assessment
will be performed as part of the lNEL-wide comprehensive RIfFS scheduled for 1998.
19
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Table 6-1. Contaminants of concern. their respective MCLs. and risk-based concentrations. a
Risk-based concentrations
Chemical MCL (~g/L) Risk at MCL Risk= 10-6 (1J.g/L) Risk= 1 0-4 (~g/L) HI=l (J.!g/L)
Trichloroethylene 5 2.0E-6 3 300 NA
Tetrachloroethylene 5 2.0E-6 1 100 400
Lead 50 NA NA NA NA
Radionuclid~s MCL
(pCiIL) (pCiIL) (pCiIL) (pCiIL)
Strontium-90 8 I.OE-S 0.60 60 NA
a. The data that suppon this list of contaminants are contained in Table 5-1. The contaminants were taken from validated
data from 1989 and 1990 groundwater sampling and include only those contaminants that were found in both years.
Contaminants that were not found above MCLs in more than one well and on a recurring basis were not included in this
list .
7. DESCRIPTION OF AL TERNA TIVES
Four alternatives were considered for this interim action: (1) no action; (2) groundwater extraction and
treatment by air stripping. carbon adsorption. and ion exchange; (3) groundwater extraction and treatment by carbon
adsorption and ion exchange; and (4) groundwater extraction and treatment by chemical destruction and ion exchange.
These four alternatives are discussed in greater deUil below.
7.1 Common Features
Each of the alternatives. except for the no action alternative. have the following common features:
.
Will operate for a maximum of two years.
.
Will pump at an average rate of approximately 50 gallons per minute (gpm) and occasional rates of 10
to 100 gpm.
.
Will achieve performance standards (given in Table 9-2) for contaminants of concern in the treated
groundwater effluent
.
Groundwater monitoring wells within the contaminant plume will monitor the effectiveness of the interim
action in reducing contaminant concentrations in th~ groundwater. These wells may also be used as
extraction wells to expedite the removal of contaminated groundwater.
.
Include installing on-site groundwater treatment facilities to remove contaminants from the groundwater.
The treated effluent will be discharged to the TAN disposal pond.
. . Existing institutional controls such as the air sparger and monthly drinking water monitoring program will
continue. New administrative and institutional controls will be implemented as appropriate to supplemem
engineering controls and minimize exposure to releases of hazardous substances during remediation.
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7.2 Alternati yes
7.2.1
Alternative 1: No Action
The NCP reqUires that the "no-action" alternative be considered for every site to determine a baseline against
which otherremedial alternatives can be measured. Under this alternative. no remedial actions would be taken beyond
those already in place such as the air sparging system. The monthly drinking water program would continue and
groundwater mOniroring would be implemented to evaluate changes in the contaminant plume.
7.2.2
Alternative 2: Groundwater Extraction and Treatment by Air Stripping, Carbon Adsorption, Ion
Exchange
This alternative differs from the no action alternative because active measures wOl,lld be taken to reduce the
contaminants near the TSF-OS injection well and in the surrounding groundwater. which would reduce the threat to
drinking water supplies and help prevent further degradation of groundwater while the au 1-07B RIlFS is being
completed. Alternative 2 employs well-established and widely used technologies. .
Groundwater will be extracted from the TSF-QS injection well and perhaps nearby groundwater monitoring
wells that are capable of capturing contaminated groundwater. The extracted groundwater would be pumped to an
on-site facility comprised of: a filtration system to remove sediment, an air stripper equipped with a carbon scrubber
to remove organic contaminants; and an ion exchange system to remove inorganics and radionuclides. The filtration
system is a physical process that removes suspended solids from the groundwater. 1his system could be a tank where
solids are allowed to settle out of the groundwater or a porous media such as sand or paper that captures the solid
particles as the groundwater passes through the filter. Sediment would be analyzed for hazardous and radioactive
contaminants and will be disposed of as identified in Table 9-1.
,-\
Air stripping is a mass'transfer process in which volatile contaminants in water are transferred to gas. Air
stripping is frequently accomplished in a packed tower equipped with an air blower. In this type of system, water flows
down through a packing materia,l that produces a large surface area for gas transfer, while air flows upward, and is
exhausted tPI'ough the top. Because volatile contaminants such as TCE and PCE have a relatively high vapor pressure,
they readily leave the aqueous stream for the gas phase. Air flowing through the top of the air stripper would pass
through an activated carbon treattnent syStem to capture the organic contaminants released from the groundwater. The
activated carbon would selectively adsorb the contaminants by a surface attraction phenomenon in which the organic
molecules are attracted to unsa$tjed electrostatic charges on and in the pores of the carbon granules. Air from the
air stripper may also be passed tiJ!ough a filter to remove solid particles, radioactive particles, and water mists that
might be generated from the air stripper. Air emissions would be monitored for compliance with regulatory standards
for air pollutants. The carbon treabnent system would be monitored for contaminant breakthrough, and as necessary,
the carbon would be replaced. The spent carbon would be regeneratedaI a facility operating in compliance with EP A's
Revised Procedures for Planning and Implementing Off-Site Response Actions.
In addition to passing through the air stripper, the groundwater would also pass through one or more ion
exchange columns. Ion exchange is a process whereby the dissolved metals and radionuclides are removed from the
groundwater by being exchanged with relatively harmless ions held by the ion exchange material. Ion exchange resins
are primaril y synthetic organic materials containing ionic functional groups to which exchangeable ions are attached.
Although specific ion exchange and sorptive resins syStems must be designed on a site-specific basis, typical
configurations include parallel columns to allow for one or more columns to be taken out for regeneration while the
remaining columns would stay in service. Procedures for recovery or regeneration of the spent resins would be
determined during remedial design. It is anticipated that the spent resins would be disposed of in available storage
areas at the Radioactive Waste Management Complex (RWMC) at the lNEL as low-level radioactive waste.
21
.-..-.--.
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The treated effluent would be monitored for treatment efficiency prior to discharge to the TAN disposal pond.
where the effluent would evaporate and percolate into the ground.
7.2.3
Alternative 3: Groundwater Extraction and Treatment by Carbon Adsorption and Ion Exchange
Although the purpose of this alternative is the same as Alternative 2. a different groundwater treatment system
is proposed which uses activated carbon as the primary treatment technology for the removal of organic contaminants.
The remedial objective. filtration. ion exchange. and effluent disposal systems remain the same. but an activated
carbon system would replace the air stripper and associated offgas treatment system. Activated carbon is a technology
that is adaptable for the removal of organic and inorganic contaminants from both air and aqueous wastes.
Alternative 3 employs weIl-established and widely used technologies.
FoUowing pretreatment by the filtration system. the COntaminated groundwater would be passed through
several carbon adsorption columns where the carbon would selecti vely adsorb the organic contaminants. In addition.
the water would also pass through ion exchange columns to remove inorganic contaminants and radionuclides. Use
of several carbon adsorption columns would provide considerable flexibility. Various columns could be arranged in
series to increase service life between regeneration or in parallel for maximum hydraulic capacity. The piping
arrangement would also allow for one or more beds to be regenerated while the other columns remain in service.
The disposal of the sediment and spent resins would be the same as for Alternative 2. Spent organic carbon
under this alternative couid contain organic and inorganic contaminants as well as radionuclides. In this instance, the
spent carbon could be classified as a combustible mixed waste that would require disposal on-site at the Waste
Experimental Reduction Facility (WERF) or similar facility.
7.2.4
Alternative 4: Groundwater Extraction and Treatment by Chemical Destruction and Ion Exchange
Although the purpose of this alternati ve is the same as Alternatives 2 and 3. a different groundwater treatment
system is proposed. The remedial objective, filtration, ion exchange, and effluent disposal systems remain the same,
but a chemical treatment system would replace the air stripping or activated carbon systems.
Following pretreatment by the filtration system, the contaminated groundwater would be passed through a
chemical treatment system to destroy the organic contaminants, and an ion exchange column to remove inorganic
contaminants and radionuclides. The chemical treatment system would detoxify organic contaminants by actually
changing their chemical forms from complex organic molecules to simple, more benign molecules by using ultraviolet
light and either ozone or hydrogen peroxide. The ultraviolet light provides an energy source to break chemical bonds
while the ozone or hydrogen peroxi~ provides an oxygen atom to form benign compounds.
The disposal of sediments and spent resins would be the same as Alternative 2. Treatment residuals
contaminated with organic compounds would not be generated and would not need to be disposed.
8. SUMMARY OF COMPARATIVE ANALYSIS OF AL TERNA TlVES
The remedial alternatives for the TSF-05 injection well and surrounding groundwater interim action were
compared according to nine criteria developed on the basis of the statutory requirements ofCERCLA Section 121 and
the NCP. These evaluation criteria are shown below and discussed in the following sections. .
.
Threshold criteria
Overall protection of human health and the environment
Compliance with applicable or appropriate and relevant requirements (ARARs)
-------
.
Primary balancing criteria
Long-term effectiveness and permanence
Reduction of toxicity. mobility. or volume through treatment
Short-term effectiveness
Implementability
Cost
Modifying criteria
State acceptance
Community acceptance.
A summary of the comparative analysis of alternatives is shown in Table 8-1.
8.1 Threshold Criteria
8.1.1 Overall Protection of Human Health and the Environment
This criterion measures how the alternative. as a whole. achieves and maintains protection of human health
and the environment within the scope of this action. Alternative 1 is not protective of human health and the
environment. It neither reduces the threat of exposure to drinking water supplies nor preventS further degradation of
the groundwater. Alternatives 2, 3, and 4 are protective of human health and the environment Each alternati ve reduces
the risk to potentially exposed populations and preventS further degradation of the groundwater.
8.1.2
Compliance with Applicable or Relevant and Appropriate Requirements
This evaluation criterion is used to determine whether each alternative will meet all of the Federal and State
ARARs that have been identified for this interim action. Compliance with an ARAR as an evaluation criteria is not
applied to Alternative 1, the baseline alternative. Alternatives 2, 3, and 4 achieve compliance with the ARARs. This
analysis is summarized in the Statutory Determinations section.
8.2 Primary Balancing Criteria
8.2.1 Long- Tenn Effectiveness and Pennanence
The evaluation of alternatives under this criterion, the resultS of a remedial action in terms of the risk remaining
at the site after response objectives have been met and the extent and effectiveness of the controls that may be required
to manage treattnent residuals are addressed. Because the spent carbon produced by Alternative 2 would be
regenerated off-site, Alternative 2 would provide a higher degree of long-term effectiveness and permanence than
Alternatives 3 or 4. Alternative 3 is less reliable because of the necessity of long-term management controls for
providing continued protection from potential mixed-waste residuals. Alternative 4 is less reliable because of the
uncertainties associated with long-term operation and maintenance functions.
8.2.2 Reduction of Toxicity, Mobility, or Volume through Treatment
~
This evaluation criteria addresses the statutory preference for selecting remedial actions that employ treaanent
technologies that permanently and significantly reduce toxicity. mobility. or volume of the hazardous substances as
their principal element Alternatives 2. 3. and 4 reduce the mobility and volume of contaminantS in the groundwater
-------
Table 8-1. Comparative Evaluation of Alternatives.
Inrerim Action
Alternatives Evaluation
Criteria
Alternative #1'
No Actiona
Alternative #2:
Extraction and
Treaanent by Air
Stripping, Carbon
Adsorption. and Ion
Exchange
Alternative #3'
Extraction and
Treaanent by
Carbon
Adsorption and
Ion Exchange
Altematjve #4'
Extraction and
Treatment by
Chemical
Destruction and
Ion Exchange
Protection of Human Health
and the Environment
Does not satisfy
Satisfies
Satisfies
Satisfies
Compliance with ARARs
Does not satisfy
Satisfies
Satisfies
Satisfies
Long-tenn Effectiveness
o
~
+
Reduaion of Toxicity,
Mobility, or Volume
Through Treatment
~ = Poor
+ = Good
o ~
o +
+ 0
~ +
o ~
o +
o = Best
o
Shon-teml Effectiveness
~
Implementability
~
Cost
o
SWe Acceptance
+
Community Acceptance
+
a. Since the no action alternative does not meet the first two threshold criteria, it was DOt considered any fuItI1er in the
evaluation.
due to extraction- Alternative 2, through the regeneration of spent carbon by incineration. and Alternative 4, through
chemical destruction, result In the greatest amount of organic contaminants destroyed. Alternative 3 poses a greater
risk than Alternatives 2 and 4 because the treatment residues would have to be handled as a mixed waste.
8.2.3 Short-Term Effectiveness
This evaluation criterion addresses the effects of the alternative during the construction and implementation
phase until remedial response objectives are met. Alternatives 2, 3, and4couldnotbeginoperation until 1993, to allow
sufficient time for design and construction of the treatment facilities. Alternatives 2 and 3 would require less time to
achieve protection because they are proven technologies with documented performance data, and would use readily
available systems. Alternative 4 would require more time to design and achieve full-scale operation.
AI ternati ves 2, 3. and 4 are not expected to pose significant risks to workers during construction. Shon -tenn
risks to workers. such as exposure to contaminantS during installation of groundwater monitoring wells, could be
mitigated by engineering controls and standard health and safety practices. Alternatives 2. 3. and 4 are not expected
24.
-------
to pose significant risks of exposure to workers during the handling and transportation of wastes. Short-term risks
could be mitigated by engineering controls and standard health and safety practices. Alternative 2 is nOt expected to
pose a significant risk of exposure to the community during transportation of spent carbon to a recycling facility or
during regeneration of the carbon by incineration. Organic contaminants would be bound to the car.bon during
transport and not subject to rapid release in the event of an accident Incineration would occur at an EPA-approved .
facility designed to safely handle the contaminated carbon. Short-term risks could similarly be mitigated by
engineering controls and standard health and safety practices. Alternative 4 has the disadvantage of requiring more
extensive bench- or pilot-scale studies than the other alternatives before a larger scale treatment system could be
designed. In addition, this alternative would require more complex technology, which would increase the risk to the
workers and the environment if a failure occurred.
8.2.4 Implementability
The implementabiUty criterion addresses the technical and administrative feasibility of implementing an
alternative as wel1 as various services and materials required during its implementation. Alternatives 2 and 3 employ
wel1-established technologies that are widely used in the treatment of hazardous waste streams. Air stripping, carbon
adsorption. and ion exchange are easily integrated into complex treatment systems. Alternative 4 includes chemical
oxidation to destroy organic contaminants. Treatability studies are necessary to demonstrate the applicability and
performance of this technology for a specific site; and therefore, the technical uncertainties associated with design and
construction may hinder implementation. The necessary equipment and specialists as wel1 as services and materials
are expected to be readily available for each alternative. From the perspective of waste treatment and disposal,
Alternative 3 would be more difficult to implement than Alternative 2 which would be more difficult than Alternative
4. Alternative 3 would be difficult to implement because it is possible that a mixed waste would be generated and
treatment and disposal options for mixed waste are very limited. Alternative 2 would be more difficult to implement
than Alternative 4 because spent carbon would need to be transported off-site for regeneration. Alternative 4 would
be the most implementable from a waste treatment and disposal perspective because no mixed or hazardous waste
would be generated.
8.2.5 Cost
The evaluation of alternatives under this criteria includes capital costs and annual operation and maintenance
costs. Alternative 3, estimated at $7,440,000, is the least expensive of the treatment alternatives. Alternative 4 is
estimated at $7,360.000, followed by Alternative 2 at $7,715,000. A summary breakdown of these costs for each
alternative is shown in Table 8-2.
8.3 Modifying Criteria
8.3.1 State Acceptance
1his assessment criterion evaluates the technical and administrative issues and concerns the IDHW may have
regarding each of the alternatives. The IDHW concurs with the preferred remedial alternative. The IDHW has been
involved with the development and review of the Proposed Plan, Record of Decision. and other project acti vities such
as public meetings.
8.3.2 Community Acceptance
1his assessment evaluates the issues and concerns the public may have regarding each of the proposed
alternatives. On the basis of verbal comments received during the public meeting held February 4.5. and 6. 1992 and
wrinen comments received during the comment period ending March 13, 1992, the community appears to accept the
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Table 8-2. Cost breakdown for the alternatives.
Activity CostS. $
Alternative 2 Alternative 3 Alternative 4
Treatment by Treatment by Treatment by
Air Stripping. Carbon Chemical
Carbon Adsorption, Adsorption and Destruction and
Ion Exchange Ion Exchange Ion Exchange
Facility Design 1 600.000 600.000 650.000
Well Drilling2
Well Conversion 207.000 207.000 207.000
Monitoring Wens 226.000 226.000 226.000
Waste Disposal 42.000 42.000 42.000
Subtotal 475.000 475.000 475.000
Plant Costs
Building. piping 575.000 575.000 575.000
Process Equipment 975.000 655.000 520.000
Start-up Pump Test 166.000 166.000 166.000
. Field Supervision 132.000 132.000 132,000
Subtotal 1,848,000 1,528,000 1,393,000
2-yr Operating Costs
Operating Labor 1,188,000 1,188,000 1.400.000
Technical Support 176,000 176.000 176,000
SuppliesIMaterial 520,000 460,000 480,000
Analytical Costs 520,000 520,000 520,000
Waste Disposal 320,000 480,000 280,000
Project Supervision 470,000 470,000 470.000
Subtotal 3,194,000 3,294,000 3.326,000
Plant Decontamination 176,000 176,000 176,000
Contingency3 1,422,000 1,367,000 1.340,000
Total 7,715.000 7.440,000 7,360,000
1. Design includes costs ($25.000 for Alternatives 2 and 3, and $50.000 for Alternative 4) for the small-scale design
studies needed to improve actual performance of the treatment plant.
2. Well drilling could include conversion of five existing wells to monitoring wells. drilling of two new monitoring
wells near the TSF-05 injection well, and waste treatment and disposal. These wells would be in addition to tbe
wells drilled under the RIIFS.
3. Contingency (25%) covers uncertainties in construction and operating costs only.
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preferred remedial alternative. Specific responses and comments to the remedial alternatives may be found in the
attached Responsiveness Summary (Appendices A and B).
9. SELECTED REMEDY
On the basis of consideration of the requirements ofCERCLA. the detailed analysis of the alternatives using
the nine criteria. and public comments. DOE. EPA. and IDHW have determined that Alternative 2 (Groundwater
Extraction and Treatment by Air Stripping, Carbon Adsorption. and Ion Exchange) is the most appropriate remedy
for OU 1-07A.
The objectives of the interim action are twofold:
. Reduce the contaminants near the TSF-05 injection well and in the surrounding groundwater.
. Measure aquifer parameters based on data from the groundwater extraction and monitoring wells.
Removing contaminants will help prevent further degradation of groundwater while the OU 1-07B RI/FS is
being completed. Performance information will facilitate the OU 1-07B RI/FS by providing site-specific data to be
used to evaluate the potential performance and engineering requirements of final remedial actions.
On the basis of existing information and aIJ analysis of all remedial alternatives. DOE. EPA. and IDHW
believe that the selected remedy will achieve these objectives. The interim action will end if it is determined that it
is no longer effective or when the ROD for OU 1-018 is signed. The OU 1-07B ROD will address future use of the
components of the interim action remedy.
9.1 Major Components of the Selected Remedy
The major components of the selected remedy include:
.
Extract contaminated groundwater from the TSF-05 irijection well and perhaps nearby groundwater
monitoring wells that are capable of capturing contaminated groundwater.
Install two groundwater monitoring wells within the contaminant plume t6 monitor the effectiveness of .
the interim action. These wells may also be used as extraction wells to expedite the removal of
contaminated groundwater.
.
.
Install on-site groundwater treattnent facilities to reduce contaminants of concern in the extracted
groundwater to prescribed performance standards. The selected treattnent system is air stripping. carbon
adsorption, and ion exchange.
Monitor the groundwater contaminant plume and the extractionltreattnent system during groundwater
extraction activities to track the effectiveness of the system and to ensure that performance standards are
achieved.
.
.
Modify the existing TAN disposal pond to receive the treated groundwater and ensure that discharge water
quality does not further degrade the underlying Snake River Plain Aquifer above maximum contaminant
levels.
Implement administrative and institutional controls that supplement engineering contro~s and minimize
exposure to rele:lSes of hazardous substances during remediation.
27
-".".... .."
.'--'.- "..-".. -. .. ~"."
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During operation of the interim action, the system's perfonnance will be monitored on a regular basis and
modified as warranted by the perfonnance data. Modification may include any or an of the following:
Alternate pumping of wells to eliminate stagnation points.
Pulse pumping to allow aquifer equilibration and to allow adsorbed contaminants to dissolve into the
groundwater.
.
Discontinue pumping at individual wells where remediation objectives have been attained.
It may also become apparent during design, implementation, or operation of the effluent discharge system that
the TAN disposal pond is not an appropriate discharge point. In such a case, the interim action will cease operation
until other alternatives for effluent discharge can be considered. .
The residual spent carbon wiU be transported off-site for regeneration at a facility operating in compliance with
EPA's Revised Procedures for Planning and Implementing Off-Site Response Actions. Other waste residuals from
the treatment process will be addressed on-site at existing facilities as described in Section 9.2.5 and Table 9-1.
9.2 Remedial Action Objectives
The au 1-07B RI/FS report will evaluate theeffecti veness of the interim actioqin meeting the objectives. This
evaluation will be incorporated into the ROD for the au 1-07B RIlFS.
9.2.1 Pumping Rates
An average pumping rate of approximately 50 gpm is expected with occasional pumping rates of 10 to 100
gpm. Act1.1al pumping rates win be determined to ensure efficient contaminant removal based on engineering and
hydrogeologic considerations.
9.2.2 Treated Emuent
Alternative 2 will achieve the interim performance standards listed in Table 9-2 for the contaminants of
concern in the treated effluent These standards are protective to levels appropriate to the use of the Snake River Plain
Aquifer as a drinking water source, and are technically practicable from an engineering perspective.
The effluent discharge standards forTCE. PeE. and lead are based on not creating acoodition that would cause
MG.s to be exceeded in the aquifer as a result of treated water discharge to the disposal pond. These standards are
relevant and appropriate as iJ:l..sinI groundwater performance standards.
. The standards for protection against radiation' (10 Code of Federal Regulations [CFR) 20) specify limits for
radio nuclides in effluents that may be released to unrestricted areas. Environmental fate and transpon modelling
demonstrates that effluent concentrations of strontium-90 will not exceed the MCL when that effluent reaches the
aquifer. The modelling considered 2 years of effluent discharge (the anticipated duration of the interim action),
contaminant transport through the unsaturated zones, and radionuclide half-lives.
:.
9.2.3 Air Emissions
Interim performance standards listed in Table 9- 2 are technically practicable trom an engineering perspective
and are protective to levels appropriate for controlling emissions into the air.
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Table 9-1. Waste treatment, storage, and disposal options for investigation-derived,laboratory, and treatment process
wastes. a
Waste Media Generated from Potential Hazardous Treatment Storagea Disposal
or Radioactive
Contaminantsb
Investlgatlon-derived
Well purge or Water Sampling or well TCE. Sr-90. tritium Interim action facility or Not Applicable T A..'l disposal pond
development water development, or T A..'l PWTU
decontamination
Drill cuaingsd Soil Well drilling TeE. Sr-9O. tritium. Field survey organics at T A..'l storage RWMC - radioactive
cesium-137 and rad. If cad or facility 01' near the TAN - nooradl
hazardous. grouting or TAN well head non-baz
incineration
Sediment or sludge from Solid Process Equipment, TCE. Sr-9O. tritium. Incineration or groUting at T A..'l storage RWMC after
TSF-05 injection well Sampling c:e.sium-137. cobaIt-60 facility treatment
PPE, solid wastes, Solid Facility operation and Sr-9O. ce.sium-137, Decon material, field rad at T A..'l storage RWMC - radioactive
conwniDated sampling maintenance cobalt -60 survey. send to disposal facility Cenlra! landfill or off-
and process equipment facility site faci lity if nonradl
non-baz
Laboratory wastes
.
TCLP/CLP Semi- Uquid, Sampling Sr-9O, tritium. Recycling or incineration at TAN storage Off-site (nOD-cad) or
volatile analysis Soil. me!hylene chloride facility on-site facility (00)
waste,sC,e Solid
TCLP/CLP metal Uquid.; Sampling lead, Sr-9O, tritium. Nelltta1iz:ltion. Then at TAN storage TAN disposa1 pond-
analysis waste.sC Soil. nitric acid interim action facility or facility (liquids)
Solid TAN PWTU (liquids). RWMC - rad solids
Grouting. if needed. !hen TAN - 110oradlnoo-
disposal (solids) baz solids
TCLP/CLP volatile Uquid, Sampling TeE. PCE, Sr-9O. Illterim action facility or at TAN .storage TAN disposal pond -
aoa1ysis wastes Soil. aitium TAN PWTU (liquids). facility (liquids)
Solid Incineration, if needed, RWMC - rad solids
!hen disposal (solids ) TAN - nooradlnOll-
baz solids
Alphalbeta and Liquid, Sampling Sr-9O, tritium, acids NeUtralization. Then . at TAN storage TAN disposal pood -
inorgania aoa1ysis Soil, interim action facility or facility (liquids)
wastes Solid TAN PWTU (liquids). RWMC - rad solids
Grouting, if needed, then TAN - nooradlnOll-
disposal (solids) baz solids
.
29
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Table 9-1. (continued).
Waste
Media
Generated from
Potential Hazardous
or Radioactive
ComaminahlSb
Treatment
Storagea
Treatment residuals
Spent activated carbon Solid
Process Equipment
TCE
Incineration and
recycling
at TAN storage
facility
Off-site facility
Sediments
Solid
Process Equipment
cesiwn-137, cobalt-60 Incineration or grouting
at T A..'I1 storage -..' 'RWMC
facility
Spent ion exchange
resin
Solid
Process Equipment
Sr-90, cesium-137,
coball-60
None
at TAN storage
facility
RWMC
a. Treatment, storage, and disposal options given are the preferred choice. If these facilities or options are not available,
equivalent facilities or options will be used, or the wastes will be stored at the T AN storage facility until treatment or disposal
options are available, or until a fInal remedy under an applicable ROD is implemented. This storage area will meet RCRA
substantive requirements.
b. The contaminants listed are those that could potentially be found in the waste at levels above RCRA characteristic limits for
hazardous contaminants or above detection limits for radioactive contaminants. These contaminants may not be found in the
wastes. If these contaminants are not found, the identified treatment, storage. or disposal option would not be implemented.
c. These laboratory analysis methods use chemicals to improve the effIciency of the analysis process (Le, methylene chloride is
added for semi-volatile analyses; and acids for metals, alphalbeta, and inorganics). If radioactive contaminatiol1 is detected
in the analysis waste. these chemicals would be renuned to the INEL. These laboratory wastes may.be generated to determine
appropriate disposal of the process and investigation-derived wastes. These laboratory wastes would be small in voluine (less
than 100 mL per sample), thus the waste would be stored similar to Note (a) until sufficient volume is available for the identified
treaanent option.
d. These cuttings would be surveyed with fIeld instruments for hazanlous and radiological contamination. If the cuttings do not
exceed screening action levels (less than 25 parts per million organics based on headspace analysis, less than 100 coums per
minute of beta! gamma. or no detectable alpha), they will be disposed of next to the TAN disposal pond. If the cuttings exCeed
action levels, they will be stored at the TAN storage facility or a radioactive storage area. pending ultimate disposal based on
their waste characteristics.
e. Semi-volatiles are not contaminants of concern, but laboratory analyses could be used for screening purposes.
The emission standard for lead will not exceed 1.5 micrograms per cubic meter, as prescribed by 40 CFR 50.12
(National primary and secondary ambient air quality standards for lead). The emission standard for strontium-90 will
not exceed an effective dose equivalent of 10 millirem per year (mremlyr), as prescribed by 40 CFR 61.92 (National
emission standards for emissions of radio nuclides other than radon from Department of Energy facilities).
Emission standards for trichloroethylene and tetrachloroethylene were derived using the Idaho Air Quality
Bureau's New Source Policy for Toxic Air Pollutants in accordance with Idaho Administration Procedures Act
(lDAP A) ~ 16.01.01952,02. Although not legally enforceable, these guidelines will be addressed in implementing the
interim action.
.
..
9.2.4 Obtain Data on Aquifer Performance
To the extent practicable, data collected under the remedial alternative on contaminant removal effecti veness
from the aquifer (sustained contaminant levels), on aquifer characteristics (transmissivity and well response), and on
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.
Table 9-2. Interim perfonnance standards.
Contaminants of Concern
Treated Water Discharge Standardsa
Air Emission S tandanls
Trichloroethylene
Tetrachloroethylene
Lead
Strontium-90
5 flglL
5flgIL
50flgIL
300 pCiIL
0.OOO511bfurb
0.013 lbfurb
1.5 flg/m3 c
10 mrem/yrd
a. See discussion in Section 9.2.2 for basis.
b. Emission standards for trichloroethylene and tetrachloroethylene were derived using the Idaho Air QuaLity Bureau's New Source Policy for
Toxic Air Pollutants in accordance with IDAPA 16.01.01952.02.
c. Ambient air concentrations for the lead were taken from 40 CFR Part 50.12. Primary and Secondary Ambient Air Standards for Lead.
d. Emission standards for scrontium-90 are a National Emission Standard for Hazardous AirPollutants standard for the effective dose equivalent
to the public under 40 CFR Part 61.92. NalionaJ Emission Standards for Emissions of Radionuclides Other Than Radon from Deparrinent
of Energy Facilities.
contaminant levels in the groundwater (types and concentrations of contaminants) will also be used in the OU I-07B
RIlFS. These data will be used in the evaluation of the alternatives considered for the final action under the OU 1-
07B RIlFS.
9.2.5 RCRA Waste Characteristic Detennination
On the basis of an evaluation of existing documentation. DOE has detennined that the groundwater
contaminants are not listed RCRA hazardous wastes. As appropriate, investigation-derived wastes and treatment
residuals will be sampled and analyzed in accordance with fIDAP A 16.01.05005. If these wastes exhibit RCRA
characteristics, the wastes would be hancDedin accordance with RCRArequirements. Treannent. storage, and disposal
options for all identified interim action wastes are given in Table 9-1.
The residual spent carbon. which would not be radioactive, will be transponed off-site for regeneration at a
facility operating in compliance with EP A's Revised Procedures for Planning and Implementing Off-Site Response
Actions. The spent resins are not expected to accumulate high concentrations of metals since the levels of the metals
in the water are relatively low (Table 5-1). Therefore. the waste resin would not be a mixed waste, but would only
be a low-level radioactive waste. Drill cuttings from wells installed near the TSF-05 injection well have not been
hazardous in the past, and the cuttings from the interim action wells are also expected to be nonhazardous. Other waste
residuals from the treatment process will be addressed on-site at existing facilities (Table 9-1).
9.2.6 Estimated Waste Generation and Disposal Options
.
The wastes will be disposed in accordance with Table 9-1. Low-level radioactive wastes (an estimated 160
drums ofion exchange resins and sediments) will be disposed of on the INEL at the R WMC in the Subsurface Disposal
Area. An estimated 45 drums of hazardous carbon will be regenerated. Minimal quantities (which cannot be estimated
at this time) of other hazardous wastes, such as the laboratory wastes identified in Table 9-1. may be disposed of offsite
in accordance with EP A's Revised Procedures for Planning and Implementing Off-Site Response Actions. Solid
waste (an estimated 275 cubic yards of personnel protective gear and facility paper waste) will be disposed at both
offsite and on-site facilities, depending on availability.
.
31
.. ".- ~.' .
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.
If these existing treatment, storage, and disposal facilities are inadequate or unavailable. either:
The wastes would be stored in a TAN storage area until additional disposal facilities are available, or
. -The interim action would be stopped until additional waste storage capacity is available.
The selected remedy is not expected to generate mixed wastes. However. minimal amounts of contaminated
sludge that may exhibit mixed waste characteristics could be extracted from the TSF-05 injection well. 1his material
will be dealt with as described in Table 9-1.
10. STATUTORY DETERMINATION
The selected remedy meets the statutory requirements of Section 121 ofCERCLA. as amended by SARA. and
to the extent practicable, the NCP. The following sections discuss how the selected remedy meets these statutory
requirements.
10.1 Protection of Human Health
The selected remedy protects human health by reducing contaminants near the TSF-05 injection well and in
the SUII'ounding groundwater. Removing contaminants will also help prevent further degradation of groundwater
while the au 1-07B RI/FS is being completed. Contaminants of concern in the waters discharged (0 the TAN disposal
pond wilI be treated to achieve the perfonnance standards given in Table 9-2. Any short-term threatS associated with
the selected remedy could be addressed by engineering controls and standard health and safety practices. In addition,
no cross-media impacts are expected. .
10.2 Protection of the Environment
Although a quantitative ecological assessment was not completed. a qualitative appraisal of the contaminants
of concern suggests that these contaminants will not result in short-term adverse impacts to the aquatic and terrestrial
biota at TAN.
The maximum measured concentration of trichloroethylene (1,300 ~gIL) in groundwater monitoring wells
at the TAN does not exceed the acute (4S ,000 JlgIL) or chronic (21.900 ~gIL) freshwater quality criteria concentrations
for ttichloroethylene. Similarly. the maximum measured concentration of tetrachloroethylene (71 J.LgIL) does not
exceed the acute (5.280 ~gIL) or chronic (840 ~g/L) freshwater quality criteria concentrations for tetrachloroethylene.
Although the maximum measured concentration oilead (515 JlgIL) in groundwater monitoring wells at the
TAN exceeds both the acute (83 ~gIL) and chronic (3.2 ~g/L) freshwater quality criteria concentrations for lead,
treattnent of the groundwater to the prescribed perfonnance standards should minimize potential ecological effects
from the treated effluent. For example, the number oflitersoftreated effluent that a deer or a duck would have to ingest
on a daily basis in order to pose an unacceptable risk was derived from toxicity data. The magnitude of ingestion for..
a deer was calculated to be approximately 2,040 liters/day and for a duck approximately 160 liters/day. These
magnitudes are not possible.
Similar toxicity data for wildlife are not readily available for strontium-90. Because some wildlife might be
affected by chronic exposure to strontium-90, the discharge area will be observed on a regular basis for potential
impacts to the e~vironment.
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.
.
10.3 Compliance with ARARs
The selected remedy will comply with all Federal ARARs. and promulgated State ARARs that are more
stringent than Federal ARARs.
10.3.1 Chemical-Specific ARARs
National Emission Standards for Emissions of Radionuclides Other than Radon from Department of
Energy Facilities (40 CFR 61.92). 1his applicable requirement specifies 10 mrem/yr for radiation
exposures for the general public from ambient air concentrations of radio nuclides.
National Ambient Air Quality Standards (40 CFR 50.12). 1his applicable requirement specifies 1.5 Ilg/
m3 for ambient air concentrations oflead. .
.
Safe Drinking Water Act (40 CFR 141). TIlls relevant and appropriate requirement establishes MCLs for
TCE. PCE. lead. and strontium-90 in groundwater that may be used for drinking water.
10.3.2 Action-Specific ARARs
.
Harzardous Waste Management Act IDAPA 16.01.05005,01.05009,01.05011. Where RCRA40CFR
268 is more strigent than IDAPA 16.01.05011 the federal law will be applicable.
1
..31
Applicable requirements of the Regulation of Standards of Performance for New Stationary Sources
(IDAPA ~16.01.01952, 02) which specifies that new sources of air emissions shall achieve the greatest
degree of emission reduction that has been adequately demonstrated.
.
Applicable requirements of the rules for the Control of Fugitive Dust, IDAPA U6.01.01251 and -01252
which specify that all reasonable precautions be taken to prevent the generation of fugitive dusts.
.
Any applicable substantive requirements of the State ofldaho Wastewater Land Application regulations
(lDAPA 16.01.176(0) and Water Quality and Wastewater Treaanent regulations (IDAPA 16.01.26(0).
These requirements establish standards for discharges of suspended solids.
10.3.3 Location-Specific ARARs
There are no location-specific ARARs identified for this interim action.
10.3.4 Other Criteria, Advisories, or Guidance To-Be-Considered
.
IDHW guidelines on emission standards for TCE and PeE (Idaho Deparanent of Environmental Quality Air
Toxies Program) will be used as to-be-considered guidelines in facility design. These standards were derived as part
of the Idaho Air Quality Bureau's New Source Policy for Toxic Air Pollutants, and are considered consistent with
IDAPA U6.01.01952, 02. .
.
To-be-considered, chemical.specific material is contained in DOE order Radiation Protection of the Public
and Environment (5400.5), Radiation Protection of Occupational Workers (5480.11), and Radioactive Waste
Management (5820.2A) which contain concentration limits on radiation exposures to workers and the public and on
releases of material containing radioactive substances. The to-be-considered. action-specific material is contained in
DOE orders 5400.5, Environment. Safety and Health Program for DOE Operations (5480.IB), Hazardous and
Radioactive Mixed Hazardous Waste Management (5480.3). Environmental Protection. Safety and Health Protection
-------
.
.
Standards (5480.4), 5480.11, and 5820.2A. These orders contain requirements for monitoring waste storage facilities,
packaging and shipping wastes, and on implementing environmental regulations at DOE facilities.
10.4 Cost Effectiveness
The selected remedy is cost-effective and provides overall effectiveness proportional to its costs and duration
for protection of human health and the environment.
10.5 Use of PennanentSolutions and Alternative Treatment or Resource
Recovery Technologies to the Maximum Extent Possible
DOE, EP A. and IDHW have determined that the selected remedy represents the maximum extent to which
permanent solutions and treatment technologies can be utilized in a cost-effective manner for this interim action. Of
those alternatives that are protective of human health and the environmem and comply with ARARs, DOE, EP A, and
IDHW have determined that this selected remedy provides the best balance of trade-offs in terms of long-term
effectiveness and permanence. reduction in toxicity, mobility, or volume achieved through treatment. short-term
effectiveness, implementability, cost. while also considering the statutory preference for treatment as a principal
element and considering state and community acceptance.
The selected remedy for OU 1-07 A is imended to help prevent further degradation of the groundwater by
reducing contaminants near the TSF-05 injection well and in the surrounding groundwater. Although this interim
action is not the final action. it will not be inconsistent with nor preclude the final response action scheduled to be
selected in 1994.
10.6 Preference for Treatment as a Principal Element
~i::..2'~
By treating the comaminated groundwater using a combination of air stripping. carbon adsorption. and ion
exchange. the selected remedy partially satisfies the statutory preference in which treatment, as a principal element,
permanently and significantly reduces the volume. toxicity. or mobility of the hazardous substances. The preference
will be fully addressed by the final response action.
11. EXPLANATION OF SIGNIFICANT CHANGES
The DOE. EP A. and IDftW have reviewed all written and verbal comments submitted during the public
comment period. Upon review of1hese comments. it was determined that no significant changes to the remedy. as
it was originally identified in the Proposed Plan. were necessary.
However. as a result of fwther review of the Proposed Plan incidental to the public review period. the
following clarifications need to be made to the Proposed Plan.
(1)
The 90% reduction in treated effluent contaminant levels proposed for the interim action treatment facility
have been changed to the interim performance standards as described in Section 9.2.2 and given in Table 9-
2. The new performance standards are technically practicable, and are expected to be protective of human
health and the environment
.
.
(2)
The Proposed Plan stated that strontium-90 levels of up to 230 pCiIL were found in the groundwater samples
collected during late 1989 and 1990. After further review of the 1989 and 1990 groundwater data during
preparation of the RIlFS work plan. an analytical result of 680 pCiIL of strontium-90 was found for wen TSF-
05. This increase in strontium-90 levels will not cause a change to the Proposed Plan or the final remedy
34
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.
-
L-
.
.
because strontium-90 was already listed as a contaminant of concern and was already listed as being above
MCLs. This increase will cause a change in the design of the treannent facility by increasing the requirements
for the ion exchange system.
(3)
The Proposed Plan stated that only TCE was found above MCLs further than 1/4 mile from the TSF-05
injection well. Further review of the 1990 groundwater data also showed a well I mile from the TSF-05
injection well that had PCE concentrations of 8 to 9 Jlg/L just above the MCL of 5 Jlg/L. This change in the
size of the PCE plume will not cause a change to the Proposed Plan or the final remedy because PCE was
already listed as a contaminant of concern. This change also fits within the original concept of using other
wells in the contaminant plume farther from the TSF-05 injection well to decrease contaminant levels.
(4)
Interviews conducted with TAN personnel have indicated that concentrated sludges were disposed of in the
TSF-05 injection well in addition to the liquid wastes mentioned in the Proposed Plan. These sludges would
have come from an evaporator that processed the same types ofliquid wastes that were discharged to the well.
Also, the condensate from the evaporator was discharged to the well. This sludge was removed in January
1990 as described in the Proposed Plan. The sludge has been analyzed and the data were placed into the
Administrative Record for the interim action on or about January 3. 1992. The types of contaminants found
in the groundwater are similar to the types found in the sludge. thus information on sludge being disposed of
in the TSF-05 injection well will not affect the final decision under the Proposed Plan.
35
. '-." ,.-.
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