United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R10-93/058
December 1992
&EPA Superfund
Record of Decision:
US DOE Idaho National
Engineering Laboratory
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50272-101
REPORT DOCUMENTAl1ON 11. REPORT NO. 2 3. Recipient'. Ace_Ion No.
-
PAGE EPA/ROD/R10-93/058
4. TIlle IUId Subtitle S Report Date
SUPERFUND RECORD OF DECISION 12/31/92
USDOE Idaho National Engineering Laboratory (Operable IL
Unit 9), ID
Seventh Remedial Action
7. Author(.) 8. . P8rtormlng Organization Rep. No.
f
8. Performing Organization Narne and AckI- 10 Proj8ct T88klWork Unit No.
11. Contract(C) or Grant(G) No.
(C)
(G).
12. ~ng Organization Narne and Add- 13. Typa of Report & Period Covered
U.S. Environmental Protection Agency 800/800
401 M Street, S.W.
Washington, D.C. i0460 14.
15. Supplamentary Not-
PB94-964612
16. Abatract (Umlt: 200 worda)
The USDOE Idaho National Engineering Laboratory (Operable Unit 9), is part of the
890-square mile U.S. Department of Energy (USDOE) facility, located in Idaho Falls,
Idaho. The primary mission of the Idaho National Engineering Laboratory (INEL) is
n~clear reactor technology development and waste management. Land use in the area is
predominantly industrial, with some restricted agricultural and recreational uses~ The
site is contained within the northeastern portion of the Eastern Snake River Plain
(ESRP) and borders a floodplain to the west and north, and overlies the Snake River
Plain Aquifer, which is a sole-source aquifer. The site, also known as the Central
Facilities Area (CFA) Motor Pool Pond, is an administrative and support area that
includes security facilities, environmental chemistry laboratories, a motor pool and
maintenance shop, a general warehouse, and other support facilities. From 1951 until
1985, the site's CFA Motor Pool Pond received wastes from two sumps that collected
wastewater from the washing of fleet vehicles and from roof downspouts. During the
35-year service life of the Motor Pool Pond, an estimated 15,900 liters of wastewater,
containing metals and organic compounds associated with road dust, oil, grease, and
some residual radioactive contamination, per day were discharged into the pond. In
(See Attached Page)
17. Document Analpla L D88crlptOl'8
Record of Decision - USDOE Idaho National Engineering Laboratory (Operable Unit 9), ID
Seventh Remedial Action
Contaminated Medium: None
Key Contaminants: None
b. Idenllllera/Op8n-Ended T.,ma
~ COSA11 ~roup
18. Availability Statamant 19. Security CIa88 (Thla Report) 21. No. of Page.
None 36
31. Security au. (Thia P.age) 22. Price
None
(Sea ANSJ-Z38.18)
s.. IMtruct#oM 011 "..,..
OPTIONAL FORM 272 (4-77)
(fonnarty NTI5-35)
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l
EPA/ROD/R10-93/058
USDOE Idaho National Engineering Laboratory (Operable Unit 9), ID
Seventh Remedial Action
Abstract (Continued)
late 1985, the waste was diverted through an oil/water separator to a sanitary sewer line
connected to the Sewage Treatment Plant, and onsite discharge to the CFA Motor Pool Pond
ceased. Studies conducted in 1982, 1988, and 1989 by USDOE indicated that the CFA Motor
Pool Pond sediment and soil were contaminated with VOCs, other organics, metals, and
radionuclides. Radiological surveys conducted in 1991 indicated only background levels of
radiation. Previous 1992 RODs addressed sediment at the Warm Waste Pond, ordnance and
contaminated soil, contaminated ground water at the Technical Support Facility, and
contaminated sediment and sludge in the evaporation pond, discharge pipe, and waste sump
as OUs 5, 23, 2, and 22, respectively. This ROD addresses the CFA Motor Pool Pond,
including the excavated soil and sediment along the ditch, in the ditch, at the discharge
pipe outlet, and in the pond, as OU9. Other 1993 RODs addresses the Perched Water System,
the CFA Motor Pool Pond and pit 9 of the Subsurface Disposal Area, as OUs 4, 9, and 18
respectively. Future-RODs will address any impacts from past releases to the pond that
may affect the subsurface or ground water. Based upon the results of the RI and risk
management considerations, therefore, there are no contaminants of concern affecting this
site. -
The selected remedial action for this site is n9 further action because risk data obtained
during the RI indicate that the contaminated sediment within the CFA Motor Pool Pond poses
no unacceptable risk to human health and the environment. There are no present worth or
O&M costs associated with this no action remedy.
PERFORMANCE STANDARDS OR GOALS:
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January 1992
. .
~~1.~ ST"1'~
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"'L PRcstf-~
IIIo\HO DEI'IUIIUEHf
OF H<.1W /IHO---
DIVISION OF
ENV~RONMENTAL QUb.LlTY
. .
kMho
fUtiM81
Engineering
Laboratory
Record of Decision
Central Facilities Area Motor Pool Pond
Operable Unit 4-11
Waste Area Group 4
0. lL. 9
I.
Idaho National Engineering Laboratory
Idaho Falls, Idaho
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DECLARATION OF THE RECORD OF DECISION
. .
Site Name and Location
Central Facilities Area Motor Pool Pond
Operable Unit 4-11
Waste Area Group 4
Idaho National Engineering Laboratory
Idaho Falls. Idaho
Statement of Basis and Purpose
'This decision document presents the remedial action selected for the Central Facilities Area Motor Pool Pond at
the Idaho National Engineering Laboratory (INEL). Operable Unit 4-11. 1l1is alternative was selected in
accordance with the Comprehensive Environmental Response. Compensation. and Liability Act as amended by
the Supe~d Amendments and Reauthorization Act. and. to the extent practicable. the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP). The decision is based on the information in the site
Administrative Record. which is located in the INEL Technical Library. Idaho Fall~. Idaho. .
The lead agency in this decision is the U.S. Department of Energy (DOE). The U.S. Environmental Protection
Agency (EP A) and the Idaho Department of Health and Welfare (IDHW) have participated in the scoping of the
site investigations and the evaluation of remedial investigation data. The IDHW concurs with the selected
remedy.
Description of the Selected Remedy
The DOE has determined that no further remedial action is necessary at the CF A Motor Pool Pond to ensure
protection of human health and the environment. 1l1is decision is based on the results of the human health and
ecological risk assessments. which indicate that conditions at the site pose no unacceptable risk to human health
or the environment. The EPA has approved the DOE decision; the IDHW concurs.
Declaration
It has been determined that no remedial action is necessary at this operable unit to ensure protection of human
health and the environment. 'This determination is based on the results of the site-specific risk assessment!
however. a risk assessment using default exposure factors indicates that hazardous substances may remain on the
site above health-based levels. Therefore. five-year reviews will be conducted to confirm the assumptions used to
arrive at the no remedial action decision.
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Signature sheet for the foregoing Record of Decision for Operable Unit 4-11 at the Idaho National Engineering
Laboratory by the United States Depamnent of Energy and approved by the United States Environmental
Protection Agency; with concurrence by the Idaho Department of Health and Welfare. The Operable Unit consists
of the Central Facilities Area Motor Pool Pond at the Idaho National Engineering Laboratory~
. ,"
. .
~
~vu'
Augustine A. Pitrolo
Manager "
Deparonent of Energy, Idaho Field Office
DEC319n
Date
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Signamre sheet for the foregoing Record of Decision for Operable Unit 4-11 at the Idaho National Engineering
Laboratory by the United States Department of Energy and approved by the U niced stateS Environmental
Prorection Agency, with concunence by the Idaho Department of Health and Welfare. The Operable Unit consists
of the Central Facilities Area MotOr Pool Pond at the Idaho National Engineering LaboratOry.
. .
~~
Dana Rasmussen
Regional AdminiStrator, Region 10
Environmental Protection Agency
IG/ 3!ICfL
Date
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Signature sheet for the foregoing Record of Decision for Operable Unit 4-11 at the Idaho National Engineering
Laboratory by the United States Department of Energy and approved by the United States Environmental
ProteCtion Agency, with concurrence by the Idaho Department of Health and Welfare. The Operable Unit
consists of the Central Facilities Area Motor Pool Pond at the Idaho National Engineering Laboratory.
. .
. .
. t-- Jerry L. Harris
Director
Idaho Department of Health and We1fare
'/ZO!1'
J '
. Date
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. TABLE OF CONTENTS
DECLARA TlON OF THE RECORD OF DECISION. . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . .ill
. .
DESCRIPTION OF -mE SELECTED REMEDY. . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ill
.;;' .
DECLARATION. . . . . . . . ~ . . . . . . ; . . . .. . : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iii
DECISION SUMMARY
1. SITE NAME, LOCATION, AND DESCRIPTION..............................................1
2. SIlE HISTORY AND ENFORCEMENT ACTIVmES ..........................................3
3. HIGlll..IGIITS OF COMMUNITY PARTICIPATION. .. .. .... .... . . .. .. .." .." . . . .. . .. . .. .. . . 4
4. SCOPE AND ROLE OF OPERABLE UNIT AND RESPONSE ACTION. . . . . . . . . . . . . . . . . . . . .. . . . . .5
5. SIlE CHARACTERISTICS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
6. SUMMARY OF SIlE RISKS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
7. DECISION........... .'.................... .............................. .. ......,.... .11
8. EXPLANATION OF SIGNIACANT CHANGES. . . . . . . . . . . . : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Appendix A - Respo~iveness Summary. . . . . . . ., . ., . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . .. . . . . . . .. .A-l
Appendix B - Public CommentIResponse List [[[ B-1
Appendix C - Administrative Record Index [[[ .C-l
FIGURES
Figure 1.
Figure 2.
Figure 3.
Location of the Central Facilities Area at the INEL ....................................... 1
Location of the Central Facilities Area Motor Pool Pond.................. ..... .............2
Map of the CF A Motor Pool Pond and sediment sample locations. . . . . . . . . . . . . . . . . . . . . . . . . . . .7
TABLES
Table 3.
Table 4.
Summary of analytical results for samples collected at the CF A Motor Pool Pond. . . . . . . . . . . . . . .6
Contaminant concentrations in the CF A Motor Pool Pond used in the
baseline risk assessments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Exposure frequencies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
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ARAR
CERCLA
CFA
COCA
DOE
EPA
ESRP
FFAICO
FR
IDHW
INEL
mglkg
~g'
NCP
NPL
OU
PCB
pCilg
pCiIL
RCRA
RI
RID
ROD
UCL
VOC
WAG
ACRQNYMS AND ABBREVIATIONS
Applicable or Relevant and Appropriate Requirement
Comprehensive Environmental Response, Compensation, and Uability Act
. .
Central Facilities Area
Consent Order and Compliance Agreement
U.S. Department of Energy
. .
U.S. Environmental Protection Agency
Eastern Snake River Plain
Federal Facility Agreement and Consent Order
Federal Register
Idaho Department of Health and Welfare
Idaho National Engineering Laboratory
Milligrams per kilogram
Micrograms per kilogram
National Oil and Hazardous Substances Pollution Contingency Plan (National Contingency Plan)
National Priorities Ust
Operable Unit
Polychlorinated biphenyl
Picocuries per gram
Picocuries per liter
Resource Conservation and Recovery Act
Remedial Investigation
Reference dose
Record of Decision
Upper confidence limit
Volatile Organic Compound
Waste Area Group
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. DECISION SUMMARY
1. SITE NAME, LOCATION, AND DESCRIPTION
. .
The Idaho National Engineering Laboratory (lNE!..) is a U.S. Department of Energy facility that encompasses
approximately 2,305 square kilometers (890 square miles) in southeastern Idaho (see Figure 1). The population
centers closest to the INEL Central Facilities Area (CFA) include Atomic City (11 mi southeast), Arco (18 mi
west), Howe (15 mi north), Mud Lake (32 mi northeast), and Terreton (34 mi northeast). The nearest large
population center is Idaho Falls (population 46,(00), located approximately 48 kIn (32 mi) to the east. The INEL
is currently classified for industrial and mixed use by the Bureau of Land Management, and has been designated
as a National Environmental Research Park.
The INEL is located in the northeastern portion of the Eastern Snake River Plain (ESRP) in southeastern Idaho.
1be ESRP is a volcanic plateau consisting of a series of basaltic lava flows with sedimentary interbeds. The
topography of the INEL is generally flat to gently rolling, with elevations ranging from 1,585 m (5,200 ft) in the
northeast to 1,450 m (4,750 ft) in the southwest. In th~ vicinity of CF A, the topography is flat, with the Big, Lost
River floodplain lying to the west and north and gently rolling basalt plains to the south and east. Elevations .
range from 1,500 m (4,920 ft) to 1,510 m (4,960 ft). Soils in the vicinity ofCFA are thin and poorly developed,
overlying alluvial deposits of sand. silt, and gravel.
The Snake River Plain Aquifer underlies the INEL and has been designated as a sole source aquifer pursuant to
the Safe Drinking Water Act. The depth to the aquifer varies from 61 m (200 ft) in the northern portion of the .
INEL to 270 m (900 ft) in the southern portion; the depth to the aquifer in the CFA area is approxfmately 146 m
(480 ft). Groundwater in this aquifer generally flows to the southwest.
Idaho National Engineering Laboratory
~~
~I
t
~ ....,~
~-
. -.:.:::: ..
- .-
_.
-
o I .. . .
I::::.. -----"
o 4 . 12
IQLCIIEIBtS
--
Figure t Location of the Central Facilities Area at the INEL.
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The Central Facilities Area is located in the south central portion of the INEL near the intersection of U.S.
Highways 20' and 26. TIle CFA is an administrative and support area that includes security facilities, .
environmental chemistry laboratories, a motor pool and maintenance shop, a general ~ar~o~, and other
support facilities.
. .
The CFA Motor Pool Pond is located in an abandoned gravel pit approximately 366 m (1,200 ft) east of the CFA
Equipment Yard (Figure 2). A small pond, approximately 36 by 18 t:Il (120 by 60 ft), formed in the low spot
when wastes were being discharged. Currently, the pond is typically: dry; however, runoff may temporarily
accumulate in the pond after storm events and during spring thaws. Waste water discharged to the pond
originated at the CFA Service Station (Building CF-664). A 2O-cm (8-in.) diameter concrete pipe extends
southeast from the Service Station approximately 322 m (1,056 ft) and discharges to a ditch. The ditch extends
approximately 68 m (225 ft) to an abandoned gravel pit and then continues for an additional 99 m (325 ft) to a low
spot along the south side of the pit The ditch ranges from 1 m (3 ft) deep at the pipe outlet to approximately 2 m
(6 ft) deep near the pond inlet. The bottom of the ditch is 1 to 2 m (3 to 6 ft) wide. Sediments excavated from the
ditch were placed along the north side of the ditch. 'This material was apparently removed to improve the flow of
wastewater through the ditch. The remedial investigation (RI) focused on the characterization of soils and
surficial sediments within this unlined pond and drainage ditch.
. .
Ogden Ave.
Motor Pool Pond
12. pipe (capped) ,....::6~~~""
--~~pe ::e/ Pond inle/
4
N Scale: 1..300'
I (approximate)
R92 0799
Figure 2. Location of the Central Facilities Area Motor Pool Pond. .
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2. SITE IUSTORY AND ENFORCEMENT ACTIVITIES
2~1 Enforcement Activities
. .
. .
Under the INEL Consent Order and Compliance Agreement (COCA) signed by the DOE, U.S. Environmental
Protection Agency (EPA), and U.S. Geological Survey in July 1987, the Motor Pool Pond was classified as a
Ifnd Disposal Unit and was listed as .cOCA Unit CF A-05. The release of contaminants to the CF A Motor Pool
Pond was fIrst identified and evaluated during investigations conducted in accordance with the COCA.
On July 14, 1989, the INEL was proposed for inclusion on the National Priorities List (NPL) in 54 Federal
Register (FR) 29820. The listing was proposed by the EPA under the authority granted by the Comprehensive
Environmental Response, Compensation. and Liability Act (CERCLA) as amended by the Superfund
Amendments and Reauthorization Act of 1986. The final rule that placed the INEL on the NPL was publIshed in
November 1989 in 54 FR 44184.
In December 1991. the DOE. EPA, and IDHW signed the Federal Facility Agreement and Consent Order (FFNCO).
. The FF AlCO supersedes the COCA and provides enforceable ~hedules and strategies for implementation of the
National Oil and Hazardous Substances Pollution Contingency Plan (NCP) at the 1NEL.
2.2 Site History and Investigations
From 1951 uotil1985, the CFA Motor Pool Pond received wastes from two sumps located at the CFA Service
Station (CFA 664 - See Figure 2). One of the sumps is located in the Bus Wash Bay and collected wastes from
bus washes and floor drains in the adjacent Service Bay. The Service Bay was used to perform routine servicing
of fleet vehicles. The second sump is located outside the station and collected wastes from the Steam Cleaning
Bay and water from roof downspouts. In late 1985, the wastes were diverted through an oil/water separator to a
sanitary sewer line connected to the Sewage Treatment Plant. and discharge to the Motor Pool Pond ceased.
During the 35-year service life of the Motor Pool Pond. the waste stream mainly conSisted of wastewater from
washing vehicles. According to Service Station personnel, the waste volumes were highest between 1978 and
1985, when automatic washing systems were in place at the Service Station. The automatic systems enabled
washing of up to 30 buses and 10 cars and trucks per day. These washes are estimated to have generated up to
15,900 L (4,200 gal) of wastewater per day that were discharged to the pond.
The wasteS from vehicle washes can be assumed to have contained metals and organic compounds associated with
road dust, oil, and grease. Although the Service Station was not used to decontaminate radioactively
contaminated vehicles, some residual radioactive contamination may have been removed during routine washes.
'Ibis may have occurred because this residual contamination was not detected by hand-held instruments that are
used to check vehicles leaving radioactively contaminated areas.
The CF A Motor Pool Pond was sampled as part of an INEL-wide preliminary assessment of waste streams
conducted in 1982 and 1983. One surface water sample and one surface soil/sediment sample were collected .
from the CFA Motor Pool Pond and analyzed for metals and organic compounds. The pond was sampled again in
1988 as part of a DOE Environmental Survey, designed to rank environmental risks at DOE facilities. Nine
sediment samples were collected in the Motor Pool Pond Samples were analyzed for volatile organics using the
methodology given in the Contract Laboratory Program Statement of Work dated July 1987 and Appendix D of
the DOE Environmental Survey Manual. .
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Radiation surveys of the CF A Motor Pool Pond were conducted during periods when the pond contained water'
and when the pond was dry. The most recent survey at the CFA Motor Pool Pond. which was performed on
September 4, 1991, indicated only background levels of radiation.~o water was in the pond during the 1991
survey. 1be survey was conducted using portable Geiger-Muller detectors, capable of detecting gamma and high
energy betA radiation. .
. .
In 198~. samples were collected from.soils and sediments in and around the CFA Motor Pool Pond to support
Resouice Conservation and Recovery Act (RCRA) closure activities under the COCA. These samples were
evaluated for the CERCLA site characterization. These samples were collected at the surface, at intermediate
depths, and from sediments just above bedrock. which varies from 0.6 to 5.5 m (2 to 18 ft) below the surface.
Sample locations included the discharge pipe outlet, the ditch, sediment excavated from the ditch, pond
sediments, and the northern perimeter of the pond. In addition, ten biased soil samples were collected in an area
that was not affected by CF A activities to calculate background metal concentrations. .
. .
3. HIGHLIGHTS OF COMMUNITY PARTICIPATION
On June 26, 1992, a document containing ProP'?sed Plans for three INEL sites, including the CFA Motor Pool
Pond, was released to the public. The plan was mailed to approximately 6,500 individuals on the INEL mailing
list, with a cover letter from the Director of the Environmental Restoration Division, DOE Idaho Field Office.
The public comment period for the Proposed Plan was initially scheduled from July 6 to August 5. ~992. An
extension was requested due to errors identified in a table in the Proposed Plan. The public comment period was
extended to September 8. 1992. A corrected table was p!ovided to those on the mailing list who received the
Proposed Plan. Community participation activities have been conducted as required by Sections 113(k)(2)(B)(i-v)
and 117 ofCERCLA and part XXIV of the FFAICO.
The CF A Motor Pool Pond Proposed Plan summarized the results of the human health risk assessment, which was
based on modeled exposures to contaminants identified in the pond sediments. The modeling indicated that the
contaminants at the site pose no unacceptable risk to human health and the environment. Therefore. the DOE,
EPA, and IDHW recommended No Action for the Motor Pool Pond in the Proposed Plan.
The Notice of Availability for the Proposed Plan was published in the following newspapers:
.
The Post Register (Idaho Falls) - July 1, 1992
The Idllho State Journa1 (pocatello) - July 2, 1992
Times News (Twin Falls) - July 1, 1992
Idaho Statesman (Boise) - July 2, 1992
Daily News (Moscow-Pullman) - July 11 and 12,1992
South Idaho Press (Burley) - July 1, 1992
The Lewiston Morning Tribune (Lewiston) - July 1. 1992.
.
.
.
.
.
.
Copies of the plan are available in the Administrative Record file in the INEL Technical Library. 1776 Science
Center Drive, Idaho Falls. Copies of the file are also available in the INEL Information Repository section of
public librarIes in Idaho Falls. Pocatello, Twin Falls, Boise, Shoshone-Bannock Library at Fort Hall, Idaho State
Library in Boise, and the University of Idaho Library in Moscow.
Technical briefings on the Proposed Plan were held on July 13 in Twin F~lls, on July 14 in Moscow, and on July
15 in Pocatello. The Twin Falls briefing was presented to the Twin Falls City Council and was open to the
public; the Moscow and Pocatello briefings were presented to the public. .
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. .
Articles explaining the Proposed Plan for the CF A Motor Pool were printed in the May and July 1992 issues of
the INEL Reporter newsletter, which is diStributed to meIIibers of the public on the INEL mailing list
Additionally, during the public comment period (from July 6 to September 8), public meetings on (be Proposed
Plan were held in Idaho Falls on July 20. BUrley on July 21, Boise on July 22, and Moscow on July 23. An INEL
press release, informing members of the public of the upcoming meeting in their area, was disttibuted to State-
wide media. Personal telephone calls were made by INEL Outreach Offices in Pocatello, Twin Falls, and Boise
to inform key representatives from community groups of the opportunity for public comment
. ~
w ".
The notices of the. times and dates of public meetings were published in the following newspapers:
.
The Post Register (Idaho Falls) - July 17. 1992
The Idalw State Journal (Pocatello) - July 17, 1992
Tunes News (Twin Falls) - July 20, 1992
Idalw Statesman (Boise) - July 20, 1992
Daily News (Moscow-Pullman) - July 21, 1992
South Idaho Press (Burley) - July 20. 1992
The Lewiston Morning Tribune (Lewiston) - July 21, 1992,
.
.
.
.
.
At the meetings, representatives from the DOE, EPA, and IDHW discussed the Proposed Plan. answered
questions, and received public comment Verbatim transcripts of each public meeting were preparep by a court
reporter and are available. along with the written comments, in the Administrative Record. Comments received
from the public were considered in the final decision and have been summarized and addressed in the
Responsiveness Summary attached to this Record of DeCision (Appendix A).
.'#<1
:~I
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4. SCOPE AND ROLE OF OPERABLE UNIT AND RESPONSE ACTION
Under the FFAlCO, the INEL was divided into 10 Waste Area Groups (WAGs) to better manage the investigation
of potential waste sites. Each WAG contains several operable units.(OUs) which consist of one or more potential
waste sites. This strategy allows the DOE, EPA. and IDHW to focus available cleanup resources on those areas
that potentially pose an unacceptable risk to human health and the environment WAG 4 consists of 13 OUs
located at CF A. The CF A Motor Pool Pond is designated as OU 4-11.
-'
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"
OU 4-11 includes the excavated sediments along the ditch arid the sediments at the discharge pipe outlet. in the
ditch. and in the pond. Data collected for the RI risk assessment indicate that the contaminated sediments within
these areas of the CF A Motor Pool Pond do not pose an unacceptable risk to human health and the environment.
Therefore, based on the results of the RI and risk management considerations, it was determined that the CF A
Motor Pool Pond required no further action to protect human health and the environment. Any impacts from past
releases to the pond that may affect the subsurface (vadose zone) or groundwater will be evaluated in OU 4-13,
the WAG 4 Comprehensive Remedial InvestigationIFeasibility Study (RIlFS).
S. SITE CHARACTERISTICS
The results of the 1982, 1988, and 1989 site investigations indicate that the CFA Motor Pool Pond sediments are
contaminated with metals, volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), and
radionuclides. The contamination appears to be concentrated in sediments in the ditch and the excavated
sediments adjacent to the ditch.
In 1989,41 samples (excluding replicate samples) of the Motor Pool Pond sediments were collected and analyzed
for metals and for VOCs. 1birty-eight of the samples were analyzed for gamma-emitting radionuclides. and three
. .
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. for alpha-emitting radionuclides (See Table. 1). Four samples were also collected and analyzed for a broad range
of metals and organic compOunds (Appendix IX of 40 Code of Federal Regulations 264). In addition. 10 soil
samples were collected ~utJ;1 of ~e pond and analyzed to establish background concentrations of metals (Figure 3~.
. .
Barium. beryllium, cadmium, chromium. lead, mercury, and thallium were found in concentrations exceeding
background levels in the Motor Pool Pond area. Beryllium, cadmium, chromium and lead were most frequently
detected above background levels. Beryllium con~ntrations ranged from 0.22 to 1.4 mglkg (milligrams per
kilogram or parts per million), cadmium from 0.53 to 38.8 mglkg, chromium from 8.2 to 91.3 mglkg, and lead
. from 10.6 to 631 mglkg; The highest metals concentrations were found in the sediments in the ditch from 0 to 2
m (0 to 7 ft) in depth. and in sediments excavated from the ditch.
In addition, four organic compounds (acetone, 2-butanone, 4-methyI2-pentanone, and methylene chloride) were
detected at a depth of 4 m (13 ft) in the pond sedimentS. 1be maximum concentrations in the sediments were 85
J.1.gIkg (micrograms per kilogram or parts per billion), 90 J.1.gIkg, 40 J.1.gIkg, and 40 J.1.glkg, respectively. Methylene
Table 1. Summary of analytical results for samples collected at the CFA Motor Pool Pond.
Frequency of Estimated upper Units
Frequency of detection greater range of Range of detected
Chemical detection- than backgroundb backgroundbc . concentrations
Antimony 41/41 0/41 5.8 1.7 - 5.8 mglkg
Arsenic 41/41 0/41 22.1 1.4 - 18.4 mglkg
Barium 41/41 1/41 334.5 92.8 - 434 mglkg .
Beryllium 41/41 13/41 <0.23 0.22 - 1.4 mglkg
Cadmium 41/41 11/41 1.6 0.53 - 38.8 mglkg
Chromium 41/41 9/41 30.7 8.2 - 91.3 mglkg
Lead 41/41 . 14/41 50.2 10.6 - 631 mglkg
Mercury 214 214 <0.09 0.35 - 1.2 mglkg
Nickel 41/41 0/41 42.8 13.6 - 37.7 mglkg
1ba1lium 11/41 2141 0.6 0.3 - 1.0 mg/kg
Methylene Chloride 6141 6/41 (0) 3.0 - 40.0 J.1.g/kg
Acetone 1/41 1/41 (0) 85.0 J.1.glkg
2-ButaDone 1/41 1/41 (0) 90.0 J.1.glkg
4-Metyl-2-PentaDone 2/41 2141 (0) 5.0 - 40.0 J.1.g/kg
Tettacbloroethene 2/41 2141 . (0) 4.0 - 76.0 J.1.glkg
Aroclor-1260 1/2 1/2 (0) 1,470 J.1.glkg
Cesium-137 21/38 . NA (0) 0.17 - 8.41 pCilg
Americium-241 3/3 NA (0) 0.17 - 2.72 ~iIg
Plutonium-239 3/3 3/3 (0) 0.14 - 4.29 pCilg
a. Replicale samples are not included in the total number of samples.
b. (0) - Background concentrations are assumed to be zero (assumed ~ be man-made and not naturally occurring).
NA - Background concenttations not available for CF A Motor Pool Pond.
c. Values defP.nnined by calculating the 95% upper confidence limit (Uo..) of the arithmetic mean.
-------
. . -[:~ ~ Pond inlet
--- -..--
~.~:~.~---_..-..~..--:--..~..~
./.~.~ --..~..~..~..~
./ ./- --................ .--...--
,/ /' --. -----
// 0 CFAmotorpoolpond -------==:::----
,/ . CFA1S01 ---- -----
. CFA1502 ---- --------------
. CFA1503 --------------- -----
. CFA1S04 ---'-
.CFA1SOS
. CFA1S06
. CFA1S07
. CFA1soe
. CFA1S09
. CFA1510
+
. .
. .
CFAOS01 V
CFA0701
rCFA0103
~ CF~~G
CFAOC01 ~e~
CFA161 0
Pipe outlet
CFA motor pool pond
020.0
80
120 (Ieet)
48.8 (met8lS)
~ Abandoned pie! pit
o e.1 12.2
24.4
Contour lines represent
2.51001 (0.75 meter) Inl8IVais.
Figure 3. Map of the CF A Motor Pool Pond and sediment sample locations.
R93 0085
chloride and tetrachloroethylene were also detected in two samples colleCted from excavated sediments, with
maximum concentrations of 40 ~glkg and 16 ~g/kg, respectively. The PCB Aroclor-1260 waS detected in the
sample and its replicate collected from the ditch near the pipe outlet The maximum concentration was 1,410 ~gI
kg. The radionuclides americium-241, cesium-131, and plutonium-239 were detected in surface sediments in the
ditch and pond area. 'The highest concentrations of each detected radionuclide were 2.12 pCi/g for americium~
241, 8.4 pCilg for cesium-131, and 4.29 pCilg for plutonium-239.
Metals of potential concern in the sediments are:
.
Americium-241, chromium-VI, cesiu~-131, and plutonium-239, which are classified as Group A
human carcinogens
.
Cadmium, a Group B 1 probable human carcinogen
.
Beryllium and lead, Group B2 probable human carcinogens
.
Barium and chromium-ill, noncarcinogens which may have adverse human health effects.
-------
Another contaminant of concern is the PCB.Aroclor':1260, which is classified as a Group B2 probable human .
carcinogen.
The potential for migration of contaminants to groundwater was evaluated by two methods. The first method was
the use of conservative assumptions and conventional flow equations to estimate the travel time to the aquifer.
The second method was the use of a simplified contaminant transport model, GWSCREEN (See Section 5.2 of
the RI Report). This evaluation indicates that regulatory standards for groundwater would not be exceeded due to
migration of contaminants from the CF A Motor Pool Pond sediments. ~
. .
. .
The potential pathways for exposure to humans at the CF A Motor Pool Pond and those selected for risk
assessment include (1) direct annospheric transport (inhalation), (2) dermal contact with contaminants, (3) direct
ingestion by workers or future residents, and 4) exposure to ionizing radiation emitted by radioactive
contaminants in pond sediments.
Potential exposure scenarios for which the pathways were evaluated at the CF A Motor Pool Pond were limited to
present occupational and future residential users. The potential for exposure to the public is currently limited due
to the restricted access policy at the INEL. However, a residential scenario was evaluated because it is possible a
home could be built on the site in the future. For the risk assessment, it was assumed that residential development
will not occur for at least 30 years so a 30-year scenario was evaluated. A l00-year residential scenario was also
evaluated. The timing of the residential scenario is considered in the radiologi~al risk assessment because
. radio nuclides decay over time.
6. SUMMARY OF SITE RISKS
The risk assessment for the CF A Motor Pool Pond considered both human health and ecological risks. The
human health risk assessment was conducted in accordance with the EP A Risk Assessment Guidance for
Superfund as supplemented by the EPA Region 10 risk assessment guidance. A qualitative ecological risk
assessment was also conducted. Risk assessment results are summarized in the following sections.
6.1 Human Health Risk
The contaminants found in the CPA Motor Pool Pond were evaluated to identify those that contribute the greatest
potential risk. A concentration-toxicity screen was used which involved ranking each contaminant by its
highest detected concentration multiplied by a chemical-specific risk factor developed by EPA; Using this
methodology, any contaminant that contributed more than 1 % to the total risk was retained for consideration in
the baseline risk assessment. 1be concentration-toxicity screen identified chromium, barium, and lead as the main
contributors of noncarcinogenic risk. The main contributors to carcinogenic risk are chromium-VI, cadmium,
beryllium, Aroclor-1260, and all detected radionuclides. The contaminant concentr~tions used'in the risk
assessment calculations are listed in Table 2.
A human health risk assessment was performed to evaluate current-use (occupational) and future-use (residential)
scenarios. For each scenario, health risks were estimated using EPA default parameters and ~te-specific
parameters. The EP A default exposure parameters are conservative and are used to establish a baseline for
comparison. A site-specific risk assessment was then developed that reflects site conditions as they exist today
and are likely to exist in the future.
The site-specific assessments used lower exposure frequencies (EF) than the def~t risk assessment (Table 3).
These lower exposure frequencies were based on observations at CF A. The default EF value for the occupational
scenario was 250 days per year for.all exposure routes. Under the site-specific occupational scenario. the EF was
-------
Table 2. Contaminant concentrations in the CFA Motor Pool Pond used in the baseline risk assessments.
Occupational Residential Residential
Contaminant (present day)" (JO-year)' (tOO-year)'
Cesium-137 2.24 1.12 022
.
Americium-241 : 2.72e 2.60 2.34
Plutonium-239 4.29< 4.29 4.28
Aroclor-l260 124()d 1240 1240
Barium 220 220 220
Beryllim 0.97 0.97 0.97
Cadmium 11.22 1122 11.22
Chromium-VI 5.6 5.6 5.6
Chromium-III 34.4 34.4 34.4
Lead 176 176 176
a. Units are pCilg for radionuclides and mglkg for metals.
b. Values determined by calculating the 95% UCL of the arithmetic mean.
c. Highest detected alpha concentration was used.
d. For Aroclor-l260 an average of one sample with a detectable concentration and its replicate was used and the units used
are ~g/kg.
Table 3. Exposure Frequencies.
Occupational Occupational Future Residential Future Residential
Exposure Pathway Default Site-specific Default Site-specific
(dayslyear) (days/year) (days/year) (days/year)
Inba1a1ion ... . 250 12.5 350 350
Ingestion - child 350 50
Ingestion - adult 250 2.5 350 50
Dermal contact 250 2.5 350 50
Direct radi.a1ion 250 2.5 350 50
12.5 days per year for inhalation and 2.5 days per year for the other exposure routes. The 12.5 day figure
represents the 5 percent of the time the buildings at CF A are downwind of the Motor Pool Pond. The 2.5 day
figure is I percent of the default value of 250 days and is based.on the fact that CF A workers do not occupy the
pond to perform necessary work duties and therefore, are not expected to be exposed more than 2.5 days per year.
The default EF for the future residential scenario was 350 days per year for all exposure routes. Under the site-
specific future residential scenario, the EF was 350 days per year for inhalation and 50 days per year for the other
exposure routes. The time future residents would spend outdoors is the limiting factor for direct ingestion, dermal
contact, and direct ionizing Iradia~on exposures. The amount of time spent outdoors has been estimated to be at
-------
50 days per year for men and women (Exposure Factors HandbOOk. Final Report. U.S. EPA. EPAl6OOI8-89/043,
May 1989). Umited data for children suggest the maximum average time spent outdoors during the school year is
14 days per year for boys, ages 12 to 17 years. 1bis average only includes days of the school year, summer
vacation time is not included (EPA. U.S. Environmental Protection Agency, Exposure Factors Handbook. FPAI
60018-89/043, March 1990b). The exposure frequency during the 12-week summer vacation was estimated to be
three days outdoors per week. for a total of 36 days.
.
Contaminant intake rates were calculated for inhalation, ingestion, and dermal contact for metals and
radio nuclides. The parameters used to calculate intakes were based on EP A methods found in the Risk
Assessment Guidance for Superfund. Volume I, "Human Health Evaluation Manual, Part A.n For
noncarcinogens, the calculated contaminant intake rates and absorbed doses for each contaminant and exposure
route were compared to reference doses (RIDs) obtai~ed from the EP A Integrated Risk Information System and
the Health Effects Assessment Summary Tables or RIDs calculated using regulatory and occupational limits. The
hazard quotients, which are the ratio of the calculated intake and the RID for each contaminant. were summed by
exposure route and scenario to obtain hazard indices. The hazard indices were compared to the EP A threshold
value of 1 to determine whether non-carcinogenic effects from exposure to the contaminant may occur. No.
hazard indices greater than I were identified for the occupational scenarios. indicating that the contaminants at the
CF A Motor Pool Pond do not pose unacceptable noncarcinogenic health effects to CF A workers. The hazard
index for the default future residential scenario using EPA default parameters was 1.4; howev~, using site-
specific parameters. the hazard index was 0.7 (Table 4).
Table 4. Summary of risks at the CFA Motor Pool Pond.
Carcinogenic Risk Hazard Index
Scenario Contaminants Default Site-specific Default Site-specific
Occupational Radionuclides 6 in 100,000 7 in 10,000,000 NA' NA
(6E-05) (7£-07)
Chemicals 5 in 100.000 5 in 10.000.000 0.7
(5E-05) (5E-07)
Total 1 in 10,000 1 in 1.000.000 0.7 0.02
(lE-04) (lE-06)
Future 30-year Radionculides 2 in 10.000 2 in 100,000 NA NA
Residential (2E-04) (2E-05)
Chemicals 9 in 100,000 1 in 100.000 1.4 0.7
(9E-05) (lE-05)
Total 3 in 10.000 3 in 100,000 1.4 0.7
(3E-04) (3E-05)
Future 100-year Radionuclides 4 in 100.000 7 in 1.000,000 NA NA
Residential .( 4E-05) (7£-06)
Chemicals 9 iD 100.000 1 in 100.000 1.4 0.7
(9E-05) (lE-05)
Total 1 in 10,000 2 in 100,000 1.4 0.7
(IE-04) (2E-05)
a. Hazard indices are not applicable to radionuclides.
-------
" .
Carcinogenic health effects were evaluated by multiplying the intake rates of each carcinogen by a body
absorption factor and the pertinent EPA slope factor. The result is an estimated excess lifetime cancer risk. The
excess cancer risks for each carcinogen are then summed to determine the total excess cancer risk for the .giyen .
scenario. "For the occupational scenario, the current total carcinogenic risk to workers near the CF A Motor Pool
Pond is 1 in 10,000 (1 x 10-4) using the default parameters, and 1 in 1,000,000 (1 x 10-6) using site-specific
parameters (see Table 4).
. For the default 30-year future residential scenario, the total carcinogenic risk from radio nuclides and inorganic
metals is 3 in 10,000 (3 x 10-4), and 3 in 100,000 (3 x 10-5) for the site-specific scenario. For the default 100-
year future residential scenario, the total carcinogenic risk is 1 in 10,000 (1 x 10-4), and 2 in 100,000 (2 x 10-5)
for the site-specific scenario (see Table 4). -
Several sources of uncertainty, such as those associated with sampling and-analysis and the use ofEPA
established toxicity values, are common to risk assessments and generally have a low potential for adding
uncertainty to the results. Other assumptions specific to the CF A Motor Pool Pond are more important to analysis
of uncertainty. For example, exclusion of lead from the carcinogenic toxicity assessment may have resulte4 in
underestimation of the carcinogenic risk. This effect is difficult to evaluate because toxicity values are not
available for lead. The use of biased samples collected in the ditch and the pond is expected to overestimate total
contaminant concentration in the Motor Pool Pond, making the risk assessment more conservative. Because the
potential effects of the assumptiQns used in the risk assessment are not quantified, it is difficult to measure the
effect on total risk in numerical terms. However, on a qualitative basis, it appears there is a greater potential for
overestimation of exposures and risks. .
6.2 Environmental Risk
A qualitative ecological risk assessment was performed to the extent practicable on a scale as small as the
CFA Motor Pool Pond. The assessment included a review of available literature on contaminant toxicity to
animal species. Based on the limited distribution of the contaminants, discontinued use of the pond, sparse
vegetation, and limited habitat value, it is unlikely that contaminants will be accumulated in the food chain. For
these reasons, the CFA Motor Pool Pond sediments are not expected to have significant disruptive effects on
animal or plant populations or the local ecosystem. Ecological effects will be further evaluated in the WAG 4 RI/
FS and the WAG 10 comprehensive RI/FS. These stUdies are broader in scope and will enable a more
representative evaluation of varied and mobile populations.
7. DECISION
The DOE bas determined that no further remedial action is necessary at the CF A Motor Pool Pond to
ensure protection of human health and the environment This decision is based on the results of the human health
and ecological risk assessments, which indicate that conditions at the site pose no unacceptable risk to human
health or the environment The EPA has approved the DOE decision; the IDHW.concurs.
8~ EXPLANA nON OF SIGNIFICANT CHANGES
The Proposed Plan for the CF A Motor Pool Pond sediments was released for public comment on June 26,
1992. The Proposed Plan identified No Action as the alternative preferred by the DOE, EP A, and IDHW. The
three agencies have reviewed and considered all written and verbal comments submitted during the public
comment period. Upon review of comments concerning the proposed action, it was determined that no significant
changes to the preferred alternative as it was presented in the Proposed Plan were necessary.
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. .
. .
APPENDIX A
Responsiveness Summary
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Overview
On June 26, 1992, a "Dear Citizen" document containing Proposed Plans for three sites at the Idaho National
Engineering Laboratory (INEL) was released to the public. This document included a Proposed Plan for the
Central Facilities Area (CFA) Motor Pool Pond. The document solicited comments from the public on the plan
and announced the public comment period, which was originally July 6 to August 5. 1992. The comment period
was later extended to September 8, 1992 in response to a request made due to errors identified in a table in the, .
Proposed Plan. On August 6. 1992. an errata sheet was sent to the individuals who were on the mailing list for the
Proposed Plan. Comments from the public on the Proposed Plan were sought by the U.S. Department of Energy.
U.S. Environmental Protection Agency. and Idaho Department of Health and Welfare.
. .
The Federal Facility Agreement and Consent Order (FF AlCO) between the three agencies designates the CF A
Motor Pool Pond as Waste Area Group (WAG) 4 Operable Unit (OU) 4-11. The FFAICO identified the site for a
Remedial InvestigationIFeasibility Study (RI/FS).
The Proposed Plan discussed the operable unit background and the risks associated with exposure to contaminants
found in the pond sediments. The Remedial Investigation Report, available in the Administrative Record.
presents the risk assessment calculations and results. Because the Remedial Investigation. Report (and
accompanying risk assessment) indicated that contaminants at the site do not pose unacceptabIe risks to human
health or the environment. the DOE. EPA:. and IDHW recommended "No Action" for the CFA Motor Pool Pond
in the Proposed Plan.
Background on Community Involvement
During the weeks of June 29 and July 13. 1992. a Notice of Availability advertisement for the Proposed Pian was
published in the following Idaho newspapers:
. The Post Register (Idaho Falls)
. The Idaho State Journal (pocatello)
. Times News (Twin Falls)
. Idaho Statesman (Boise)
. Daily News (Moscow-Pullman)
. South Idaho Press (Burley)
. The Lewiston Morning Tribune (Lewiston).
The Proposed Plan was mailed to 6,500 individuals on the INEL mailing list with a cover letter from the Director
of the Environmental Restoration Division of the DOE Idaho Field Office, urging citizens to comment on the plan .
and to attend public meetings. Copies of the plan are available in the Administrative Record file in the INEL
Technical Ubrary, 1776 Science Center Drive. Idaho Falls. Copies of the file are also available in the INEL
Information Repository section of public libraries in Idaho Falls. Pocatello, Twin Falls. Boise. Shoshone-Bannock
Ubrary at Fort Hall, Idaho State Ubrary in Boise. and the University of Idaho Library in Moscow.
Articles about the Proposed Plan for the CFA Motor Pool Pond were printed in the May and July 1992 issues of
the lNEL Reporter newsletter. Public meetings on the Proposed Plan were held July 20 in Idaho Falls, July 21 in
Burley, July 22 in Boise. and July 23 in Moscow. An INEL press release was distributed to state-wide media to
inform the public of upcoming meetings in their areas. Personal telephone calls were made by INEL Outreach
Office personnel in Pocatello, Twin Falls. and Boise to inform community leaders and other interested individuals
. and groups of the opportunity for public comment.
-------
At the meetings, representatives from the DOE, EPA, and IDHW discussed the CFA Motor Pool Pond, answered
questions, and received public comment. Verbatim ttanscripts were prepared by a court reponer at each meeting,
and are available in the Administrative Record.
, .
. .
Technical briefmgs on the Proposed Plan were held July 13 in Twin Falls. July 14 in Moscow, and July 15 in
Pocatello. A newspaper advertisement announcing the Moscow briefing appeared in the Moscow/Pullman Daily
News on July 11. The briefing in Twin Falls was preseqted to the Twin Falls City Council and general public; the
Moscow and Pocatello briefings were presented to the general public. .
Summary of Comments Received During Public Comment Period
All oral comments, transcribed verbatim at the public meetings, and all written comments, as submitted, are in the
Administrative Record for the Record of Decision. The comments are annotated to indicate which response in
this Responsiveness Summary addresses each comment. Responses to the comments received during the public
comment period are included in this Responsiveness Summary, and were considered during development of the
Record of Decision.
Predominant public opinions on the "No Action" recommendation, as described in the Proposed Plan, were: (I)
The "No Action" proposal is unacceptable and contaminants in the pond should be cleaned up, (2) The "No
Action" proposal is acceptable and the risk calculations are adequate. and (3) Fragmentation of the INEL into
several operable units makes it difficult to evaluate the cumulative risks posed by the various operable units.
Comments and questions raised during the comment period are summarized in this Responsiveness Summary.
Oral comments received at the public meetings and submitted written comments have been organized according
to the general subject of the comments.
Comments and questions on a variety of subjects not specific to the CF A Motor Pool Pond were also received.
These subjects included nuclear waste issues at the INEL. EP A drinking water standards, and the government's
recognition of the public's opportumty. to participate in the cleanup process.
Comments on public participation have been referred to the INEL Community Relations Plan Coordinator for
consideration in the update of the INEL Community Relations Plan. General comments on INEL activities have
been referred to the INEL Public Affairs Office. Additional information on these topics may be obtained from the
INEL Public Affairs Office in Idaho Falls or from INEL Outreach Offices in Pocatello, Twin Falls, and Boise.
Summarized Comments on the CF A Motor Pool Pond
A comment tracking system has been utilized to aid the public in finding responses to individual comments on the
Proposed Plan that were provided during the comment portion of the public meetings or submitted in \Yriting.
This system has been initiated by the DOE to respond to public comments concerning responsiveness summaries
and is intended to aid the public in reviewing this Record of DeCision and Responsiveness Summary. This system
is described below.' . .
.
During the comment period held on the Proposed Plan, DOE received oral and written comments
submitted by members of the public and public officials. A number of common topics and questions
emerged.
.
To provide a manageable response to comments. questions and comments with similar themes were
condensed into a single comment or question. Immediately after each summarized comment, are series of
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1.
.
letters and numbers grouped in par~theses. This series of numbers identifies individual comments from
the transaipts or written comments. 1be first two characters of each comment code identifies the
transcript, or written document in which the comment is found (For example, the ''TI" in comme.~t Tl-
01 identifies the comment as being from the first or Idaho Falls tr~cript.) The second set of numbers
(following the hyphen) represents the sequence of the individual comments in the transcript ("T1-1" is the
first comment identified in the Idaho Falls transcript).
~
Each. comment is identified by brackets, the comment code, and the response number to assist individuals
in finding their comments and the corresponding responses. A set of indices is also provided that
identifies comments by commenter name, comment code, response number, and the page number of the
comment.
. .
. ,
.
The bracketed transcripts and wrinen comments are available for review in the Administrative Record
file. Appendix B of the Record of Decision provides the index for cross referencing the Responsiveness
Summary with the transcripts and wrinen comments. Appendix C of the Record of Decision contains the
Administrative Record index. ..
Public Comments on the CF A Motor Pool Pond Proposed Plan
Comment: The "No Action" proposal is unacceptable because the risk to human health is too great. No
action should be considered as an alternative only if the risk to human health is deemed to be one or less
than one increased cancer per one million people. The risk to human health as presented in Table 2 of the
June 26, 1992, "Dear Citizen" letter or its revision. exceeds one in one million increased cancers. It is a
simple cleanup that should be done. (T1-2, T4-1, T4-2, T4-3,T4-4, T4-S, T4-lO, W6-1, W6-2, W6-3,
W6-8)
R~nse: Although removal of the sediments in the pond is possible, the purpose of doing so under the
Comprehensive Environmental Response, Compensation. and Uability Act (CERCLA), program, would
be to reduce contaminant levels sufficiently to bring the risks to within the acceptable range. The risks to
human health and the environment from exposure to CFA Motor Pool Pond sediments were evaluated in
accordance with EP A guidance and are within the 10-4 to 10-6 acceptable risk range established in
National Oil and Hazardous Substances Pollution Contingency Plan (NCP)( 40 Code of Federal
Regulations 3(0). A summary of the risk assessment is in Section 6 of the Record of Decision; a more
comprehensive discussion is included in the RI report.
2.
Comment: The agency decision of "No Action" is noncompliant with applicable or relevant and
appropriate requirements. The PCB Aroclor-1260 in concentrations of 1.470 ~glkg alone dictates
enforceable remedial action of exhuming contaminants to prevent further migration to the aquifer. (T2-1,
T4-22, Wl-8)
Response: Although the PCB standard does not apply as an ARAR where no action is being taken, it may
be instructive to compare contaminant levels to available standards. The cleanup standard for PCBs in
soils, as established by the Toxic Substances and Control Act (TSCA) program, is 10 parts per million or
10,000 parts per billion. The highest concentration of Aroclor-1260 detected was 1.470 parts per million
or 1,470 parts per billion. Therefore, no further action would be required to meet the TSCA standard
However, the "No Action" recommendation was not based on meeting the TSCA standard, but on the
results of the risk assessment which indicate that risks from exposure to Aroclor-1260 are within the NCP
acceptable range for both carcinogenic and noncarcinogenic effects. .
-------
Comment: Based on the risk calculations and facts presented. DOE. EP A. and IDHW have made the
right recommendation. This is especially true in light of the risk calculation that assumes a 25O-day
exposure. wbichinitselfseemsunrealistic [conservative]. (fl-l. TI-3. W2-1. W2-2. W2-3)
3.
. .
. R~nse: On the basis of the data collected and the risk assessment calculations, the DOE, EP A. and
IDHW agree that the estimated risks are within the acceptable range and that no further action is
necessary for the CF A Motor Pool Pond sediments.
"
Comment: Ether of the following alternatives to the "No Action" proposal are suggested: (a)
incineration of contaminated soils under controlled conditions with cement stabilization and disposal of
the residuals. or (1;» exhuming contaminants, containerizing, and storing the containers at monitored
retrievable storage sites, or placing the containers in a permitted repository. (TI-l, T4-6, T4-12. T4-23,
W6-4)
4.
R~nse: The objective of evaluating and implementing cleanup alternatives such as those suggested
would be to reduce risks to within the acceptable range. Because estimated risks for this au were within
the acceptable range, an evaluation of cleanup alternatives is not required by CERCLA o.r the NCP.
5.
Comment: For the following reasons, the model's assumptions for occupational and residential exposures
understate risk:
a)
b)
Risk calculations for worker exposure only allow for inhalation at five percent and direct contact
at one percenL This is grossly understated due to the close proximity of the pond to the CF A.
Exposure frequencies are based on estimates of outdoor activity of 50 days per year; therefore,
exposure beyond 50 days increases the risk. In addition. the risk for houses built on this land was
not considered. (f4-11, T4-17, WI-3. W6-2)
R~nse: The site-specific scenarios evaluated for the CF A Motor Pool Pond sediments represent the
reasonable maximum exposure, given the limited area of the pond and extent of associated contamination.
a)
The inhalation exposure frequency used for CF A workers was five percent of the EP A default
value because data from the meteorology station at CF A indicate that CF A is downwind of the
CF A Motor Pool Pond approximately five percent of the time. The exposure frequency for direct
contact and other exposure routes was set at one percent (2.5 days per year) of the default value
because there are no activities at the CF A Motor Pool Pond that reqUire CF A workers to be
routinely on the site. 'The CF A Motor Pool Pond is permanently deactivated and there are no
plans for additional activities. In addition. risk assessment calculations were performed for CF A
workers using the more conservative default scenarios as recommended in the EP A risk
assessment guidance.
b)
Future residential scenarios assumed a house is construCted adjacent to the pond. The time future
residents would spend outdoors is the limiting factor for direct ingestion. dermal contact, and
direct ionizing radiation exposures. The amount of time spent outdoors has been estimated in
EP A guidance at 50 days per year for men and women (Exposure Factors Handbook. Final
Report, U.S. EPA. EPN600/8-89/043, May 1989). Umited data for children suggest the
maximum average time spent outdoors is 14 days per year for boys. ages 12 to 17 years. This
average only includes days of the school year; summer vacation time is not included. An average
of three days per week outdoors was used as a reasonable estimate at the CF A Motor Pool Pond
-------
during the 12-week summer vacation. for tOtals of 36 days for the summer and 50 days for the
entire year. Values of 50 days per year for adults and children are considered to be reasonable for
estimating exposures by ingestion. dermal contact, and direct ionizing radiation. Risk assessment
calculations using default scenarios were also done on the Motor Pool Pond. Even using the
default scenariOs. carcinogenic risks were within the acceptable 104 to 10-6 range. The Hazard
Index for noncarcinogenic risk for the default future residential scenario was 1.4 which is slightly
above the threshold ofl. The Hazard Indices were added across all pathways \or all
contaminants.
. "
. .
6.
Comment: It was noted that EP A had the following concerns with regard to the risk assessment
methodology in the plan: .
a)
b)
Heavy metals such as silver and selenium are not acknowledged.
Cesium is not included in the exposure assessment nor was testing done for alpha and beta
emitters at the waste pit
c)
The use of average values is inconsistent with EP A guidance which requires the use of a 95
percent upper level confidence limit
d)
The soil to groundwater pathway for contaminant migration was dismissed. (T4-18. T4-19. T4-20,
W14. WI-5. WI-6. WI-7)
Response: Comments from EP A Region 10 and the Idaho Depanment of Health and Welfare on the
Draft Remedial Investigation Report were incorporated into the Fmal Remedial Investigation Report. The
final report was revised to ensure consistency with EP A guidance.
a)
The metals silver and selenium were not included in the risk assessment because they were not
detected above naturally occurring levels (or background).
b)
Historical radiation surveys of the Motor Pool Pond included gamma and high-energy beta
radiation surveys. Results were slightly above background in surveys of the area conducted prior
to 1982. The most recent survey. performed in September 1991. showed only background levels
of radiation. '
During the remedial investigation. samples were analyzed using both gamma- and alpha-
spectroscopy. TIle radionuclides americium-241. cesium-137. andplutonium-239 were detected
in surface sediments in the ditch and pond area. The highest concentrations of each detected
radionuclide were 2.72 pCi/g for americium-241. 8.4 pCi/g for cesium-137. and 4.29 pCi/g for
plutonium-239.
Radionuclide concentrations were evaluated in the risk assessment for both current occupational
and future residential scenarios. Exposure to cesium was included. However. for direct radiation
exposure. cesium-137 is not a significant contributor to risk as compared to its daughter product,
barium-137. which was also included in the assessment (barium-i37 is also commonly reported
as cesium-137). The calculated risks from exposure to all detected radionuclides were withill the
acceptable risk range of 104 to 10-6.
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c)
. . d)
.
The Final Remedial Investigation Report was revised to indicate that the risk assessment was
performed using the upper 95 percent confidence interval values. .
The Final Remedial Investigation Report was revised to include an evaluation of the soil to
groundwater pathway. However. based on the groundwater modeling results. regulatory
standards for groundwater would not be exceeded. The groundwater pathway was not included
funher in this remedial investigation. The potential for groundwater contamination from
wastewater previously disposed of at the CF A Motor Pool Pond will be evaluated funher in the
WAG-4 final RIlFS, which is scheduled to begin in 1996.
7.
Comment: Averaging the concentrations of contaminants found in different areas seems inappropriate.
Using the highest concentrations would change the picture drastically. Revisions to "safe" concentrations
for these contaminants have always been downward instead of upward. and it makes more sense to err on
the conservative side. (W7-3)
Resoonse: For metals and gamma emitting radionuclides. the contaminant concentrations used in the risk
assessment were the 95% Upper Confidence Limit (UCL) of the arithmetic mean. The 95% upper
. confidence limit is "on the conservative side" and in most cases represents the reasonable maximum
exposure over the time used to calculate risk.
Because only one sample and its duplicate were available for the PCB Aroclor-1260, the average of these
two samples was used for the exposure concentration. There were insufficient data to calculate a
representative value for plutonium-123 and americium-241. Therefore, the highest concentration detected
by alpha analysis was used.
8.
Comment: What are "safe" concentrations for all populations. flora. and fauna found on the INEL? The
safe concentration level for the harvester ant, for example. is unknown. Yet the conclusion is made that
no harm will occur to humans or the environment. This seems inappropriate.
(W7-4)
Re81)Onse: It is recognized that risk based contaminations are not established for all flora and fauna found
in the INEL. However. a qualitative ecological risk assessment was Performed to the extent practicable
on a scale as small as the CF A Motor Pool Pond. The assessment included a review of available literature
on contaminant tOxicity to animal species. Based on the limited distribution of the contaminants, and the
lack of water, vegetation. and habitat value, it is unlikely that CODtaminant~ will be accumulated in the
food chain. For these reasons. the COJ1taminants identified in the CF A Motor Pool Pond sediments are not
expected to have significant disrupti3fe effects on animal or plant populations or the local ecosystem.
Ecological effects will be further evaluated in the WAG 4 RIIFS and the WAG 10 Comprehensive RIIFS.
These studies are broader in scope and will enable a more representative evaluation of varied and mobile
populations.
9.
Comment: Agency plai1s to clean up the CFA Motor Pool Pond do not accurately acknowledge the
source of nor the quantities of significant radioactive contamination of the pit The DOE's plan states
only that on several occasions vehicles and equipment with small amounts of radioactive contamination
were decontaminated at the station. Concentrations of cesium-137, americium-241 and plutonium-238,
an4 plutonium-239 as well as cobalt-60, potassium40, lead-212, and radium-226 are not adequately
accounted for. There is already tritium under CF A. so additional contaminant loading from the Motor
Pool Pond must not be allowed. (T4-15, WI-I)
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R~nse: Washing of vehicles and equipmeDt at the Service Statio~is considered to be the only likely'
source for radioactive contamination detected at the CF A Motor Pool Pond because the Service Station is
the only facility that was connected to the CFA Motor Pool Pond .1he CFA. especially the Service
Station. is not an area where large amounts of radioactive materials are routinely handled.' The risk
assessment for the pond was based on the conCentration of contaminants in the sediments. The results of
groundwater modeling show that regulatory standards. would not be exceeded by contaminants migrating
to the aquifer from the pond sediments.' .
. "
,
10.
Comment: ,The Proposed Plan does not accurately state the volatile organic ranges detected in the pond.
The Oak Ridge Survey sampling found 2-butanone at 190 Ilglkg, trichloroethane at 25 Ilglkg, toluene at
23 Ilglkg, methylene chloride at 460 Ilglkg, acetone at 85 Ilglkg, tetrachloroethylene at 76 Ilg/kg, and 4-
methyl- 2-pentanone at greater than 8,300 Ilglkg. Nine of the organic contaminants exceed EP A Contract
Required Quantification Umit criteria. (T4-16, WI-2) .
Response: The Proposed Plan is intended to be a summary of highlights of the Remedial Investigation
Report, which served as the basis for the Agencies' recommendation. The Remedial Investigation Report
is available in the Infonnation Repositories. The 1989 data were used rather than the Oak Ridge data for
risk calculations because the 1989 sampling effort was more comprehensive and data quality was better
documented. The 1989 maximum concentrations for the contaminants referenced above are: 90 Ilg/kg
for 2-butanone, 25 Ilg/kg for trichloroethane, 2 Ilg/kg for toluene. 40 Ilg/kg for methylene chloride. 85 Ilglkg
for acetone, 76 Ilg/kg for tetrachloroethylene, and 40 Ilglkg for 4-methyl-2-pentanone. It is
acknowledged that several of the contaminants listed in the comments were detected during the Oak
Ridge sampling; however, concentrations for tetrachloroethylene and 4-methyl-2-pentanone stated in the
comment could not be found.
The volatile organic compounds detected during the 1989 sampling effort were subjected to a
concentration-toxicity screen to evaluate their contribution to total risk. The concentration-toxicity
screen. which was perfonned according to EP A guidance, indicated that the volatile organic compounds
do not contribute significantly, less than one percent. to total risk. Therefore, these compounds were not
evaluated further in the toxicity assessment.
Contract-required quantification limits (CRQLs) are chemical-specific levels that a laboratory contracte(i
to.EP A must be able to routinely and reliably detect and quantify. This limit is not a risk-related value.
11.
Comment: The preliminary assessments ofW AG 10 should begin immediately. It is not in the best
interest of public health for all toxic, hazardous, and radioactive materials to continue to contaminate the
Snake River Aquifer. for another seven years before the cumulative consequences of these "No Action"
decisions will begin to be evaluated Continuing evaluation of the cumulative consequences of
contamination fro~ each subsequent "No Action" alternative will allow for the earliest detection of an
unacceptable risk. This infonnation should be included in the Proposed Plans for each OU in each WAG.
This procedure will allow the public to comprehend and track the cumulative risk of the cleanup program
as it progresses, rather than wait until the end as it is now scheduled. (T4-7, W6-6, W7-2)
Response: It is recognized that cumulative risks from the various sites are an important issue and that it is
possible for several sites which do not pose an unacceptable risk on an individual basis to do so if
evaluated on a cumulative basis. However, it would depend on several factors such as the percentage of
exposure an individual received from each site, and the toxicological effects of the contaminants and
exposure pathways at each site. For example. it would not be reasonable to assume that one individual
obtains his drinking water from two different wells at the same time. To effectively e~aluate the risks in
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. .
.
12.
the WAG 10 comprehensive RYFS, it is necessary to first collect and evaluate data from the h1dividual
OUs. This approach was developed in the INEL FF AlCO and agreed upon by the DOE, EP A. and IDHW
in. ~rdance with the NCP. The intent was to ensure that all potential contamination sources were
evaluated before the comprehensive RIIFS was completed. Data collection for the comprehensive RYFS
has been initiated; however, it is too early to draw conclusions regarding the contribution of individual
OUs to overall risk.
Comment: OUs are related and are not three separate facilities where "No Action" is proposed. DOE
needs to treat them as systems that work together. not divide them up and expect the public not to make
the connection. The public wants to see how each element fits together. If a source of contamination or
portion of a facility will be considered under a separate plan or a separate OU. these relationships must be
spelled out in detail in the information provided to the public. The appropriate OU and time-frame for
consideration must be identified in the text or as a note. (T4-8. T4-l4, 'W6-7. W7-2)
Re.';ponse: The INEL was divided into several WAGs and aus to provide an efficient, systematic method
for collecting and evaluating information and to focus resources on high priority sites first This approach
was developed by DOE, E~A, and IDHW for the FFAICO in accordance with the NCP. The FFAlCa
was presented to the public for comment during the months of August through October 1991. Section
300.430 of the NCP states that complex sites should generally be addressed in OUs to simplify and
expedite investigations and any necessary remedial action at the sites. In recognition, that risk should be
evaluated from a larger perspective than each individual site or au. a comprehensive RI/FS will be
performed for each WAG and subsequently. for the entire INEL (W AG 10) to evaluate the contribution of
individual elements to cumulative risk. Schedules for. addressing each au and for the comprehensive
evaluations are provided in the FFAlCO, which is included in the Administrative Record file. The WAG
4 Comprehensive RIfFS for CFA is scheduled to begin in 1996. This study. along with other WAG-level
RIlFSs will then feed into the INEL-wide RIfFS. scheduled to begin in 1998.
13.
Comment: More information should be provided to the public so that informed decisions can be made;
not everyone is able to obtain information from the Administrative Record. (T4-9. T4-13)
Re.-,;ponse: The purpose of the Proposed Plan is to provide the public with a summary of the Remedial
Investigation Report More detailed information regarding the investigation is included in the
Administrative Record, as required by the NCP. Prior to beginning the comment period. copies of the
Administrative Record file were placed in Information Repository sections of public libraries. and remain.
available at the six locations listed on page B-7 of the Proposed Plan.
14.
Comment: Are new waste ponds being built to replace the Motor Pool Pond? (1'3-2)
Re.c;vonse: No new pond is planned or needed to replace the CFA Motor Pool Pond Use of the pond was
discontinued in 1985. Wastes that were previously sent to the CFA Motor Pool Pond are now sent to the
CF A Sewage Treatment Plant
15.
Comment: A 30-day extension to the comment period on the Proposed Plan is requested so that the three
agencies may notify the public of an error in the risk assessment summary data in Table 2 of the June 26.
1992, "Dear Citizen" letter. This error came to light at the public meeting held in Moscow on July 23.
1992. To our knowledge, those members of the public; who were not in attendance at that meeting have
no way of knowing the information on which they are making their comments is in error. The public
should be notified of the error and provided with the correct data. (W9-1. W9-2)
-------
R~nse: On August 6, 1992. an-errata sheet was sent to the individuals who -received the Proposed Plan
by mail. These individuals were also notified at that time that the comment period would be extended as
requested . The comment period was extended from August 5 to September 8, 1992. The extension was
required due to errors in a table in the Proposed Plan which overstated risk values:
. ,
.
r-
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, .
. .
APPENDIX B
Public Comment/Response List
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Name Comment# Transcript Page Category
Chuck Broscious T4-2 381 ARA-Q8
Chuck Broscious T4-3 381 ARA:.Q2 . ,
Chuck Broscious T4-3 382 ARA-Q2
Chuck Broscious T4-4 382 ARA-lO
Chuck Broscious T4-5 382 ARA-lO . .
Chuck Broscious; T4:-6 382 ARA-02
Chuck Broscious T4-6 383 ARA-Q2
Chuck Broscious T4-7 383 ARA-Ql
Chuck Broscious T4-8 383 ARA-Ql
Chuck Broscious T4-8. 384 ARA-Q 1
Chuck Broscious Wl-l 400 ARA-QS
Chuck Broscious WI-2 400 ARA-02
Chuck Broscious WI-3 400 ARA-lO
Chuck Broscious WI-4 400 ARA-lO
Chuck Broscious WI-5 400 ARA-02
Chuck &roscious WI-6 400 ARA-Ql
Chuck Broscious WI-7 400 ARA-Ql
Chuck Broscious Wl-S 401 ARA-Q3
Chuck Broscious WI-9 401 . ARA-Q5
Dennis Donnelly TI-2 105 ARA-QS
John Horan Tl-l 77 ARA-Q7
John Horan Tl-l 78 ARA-Q7
"Lynn Mineur T4-1A 373 ARA-Q9
Lynn Mineur T4-1B 373 ARA-Q9
Lynn Mineur T4-1B 374 ARA-Q9
Lynn Mineur W6-1 417 ARA-Q9
Lynn Mineur W6-2 417 ARA-09
Lynn Mineur. W6-2 418 ARA-Q9
Bruce Schmalz W2-1 402 ARA-Q7
Bruce Schmalz W2-2 402 ARA-Q7
Bruce Schmalz W2-3 402 ARA-Q7
Patricia and- Donald Scott. T4-1 322 ARA-Q8
Patricia and Donald Scott W7-1 419 ARA-QS
Patricia and Donald Scott W7-2 419 ARA-Q9
Patricia and Donald Scott W7-3 419 ARA-Q3
Patricia and Donald Scott W7-4 419 ARA-D4
John E. Tanner TI-3 105 ARA-Q7
Michael J. Ushman TI-l 233 ARA-06
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.' .
. .
~
APPENDIX C
Administrative Record Index
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IDAHO NATIONAL ENGINEERING LABORATORY
ADMINISTRATIVE RECORD FILE INDEX
. CENTRAL FACn.ITY AREA MOTOR POOL POND
REMEDIAL INVESTIGATION 1 FEASffiILITY S11JDY OPERABLE UNIT 4-11
FILE NUMBER.
ARI.I
.
Document #:
Title:
Author:
Recipient
. Date:
AR3.3
.
Document #:
Title:
Author:
Recipient
Date:
AR3.4
.
Document #:
Title:
Author:
Recipient
Date:
ARS.I
.
Document #:
Title:
Author:
Recipient
Date:
AR6.1
.
Document #:
Title:
Author:
Recipient
Date:
. ,
. t,
BACKGROUND
5134 '
Technical Memorandum - Future Land Use Scenarios for the Central Facilities Area, lNEL
Pigott, W. R. '
, NIA
07/01/92
RIlFS WORK PLAN
5105 ."
Transmittal- CFA-OS Motor Pool Pond and ARA-Ol Chemical Evaporation Pond Schedule
EP A. Pierre, W.' ,
DOE, Lyle, J. 1.
01124192
RI REPORTS
EGG- WM-9973
Final RI for the CF A Motor Pool Pond'
Spry, M. J.
NIA
06/01/92
RECORD OF DECISION
5232
Record of Decision for the CF A Motor Pool Pond
INEL Community Relations
N/A
12110192
COOPERATIVE AGREEMENTS
ERD 1-070-91 *
Pre-signature Implementation of the CERCLA Interagency Agreement Action Plan
EPA, Findley, C. E.
DOE, Solecki, 1. E.
04119/91 '
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CFA .MOTOR POOL POND RIIFS
OPERABLE UNIT 4-11
.01122193
. .,
FILE NUMBER
.
. '
AR6.l
.
Document #:
Title:
Author:
Recipient:
Date:
.
Document #:
Title:
Author:
Recipient:
Date:
.
Document #:
Title:
Author:
Recipient
Date:
.
Document #:
Title:
Author:
. Recipient
Date:
.
Document #:
Title:
Author:
Recipient
Date:
ARlO.l
.
Document #:
Title:
Author:
Recipient
Date:
COOPERATIVE AGREEMENTS (continued)
2919*
INEL Action Plan For Implementation of the Federal Facility Agreement and Consent Order
N/A
N/A
07/21191
3205*
U.S. DOE INEL Federal Facility Agreement and Consent Order (FFA/CO)
N/A
N/A
07/22/91
1088-06-29-120*
U.S. DOE INEL Federal Facility Agreement and Consent Order (FFA/CO) W/Citizen's Guide
N/A
N/A
12/04191
3298*
Response to comments on the Idaho National Engineering Laboratory Federal Facility
Agreement and Consent Order
N/A
N/A
02/21/92
5163*
Administrative Record Ust of Guidance Documents
EPA.
N/A
08/12/92
COMMENTS AND RESPONSES
5139
Request for an extension of the comment period on the Proposed Plan for the Motor Pool Pond
at the Central Facilities Area
League of Women Voters of Moscow
Nygard, Dean
07/24192
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CFA MOTOR POOL POND RIIFS
OPERABLE UNIT 4-11
01122193 '
FII,E NUMBER
ARIO.3
.
Document #:
TItle:
Author:
Recipient:
Date:
.
DOcument #:
TItle:
Author:
Recipient:
Date:
.
Document #:
TItle:
Author:
Recipient:
Date:
ARIO.4
.
Document #:
TItle:
Author:
Recipient:
Date:
ARIO.6
.
Document #:
Title:
Author:
Recipient:
Date:
. ..
'.
PUBLIC PARTICIPATION
. .
5130
Dear Citizen Pamphlet. Proposed Plan for the Motor Pool Pond
lNEL Community Relations
N/A
06/26/92
5136
Attention: Agencies Seek Public Comment on 1l1ree Proposed Plans
lNEL Community Relations
N/A
07/01/92
5141
Page B-6 Correction of the Dear Citizen Pamphlet, Proposed Plan for the Motor Pool Pond
INEL Community Relations
N/A
08/05/92
PUBLIC MEETING TRANSCRIPTS
5164-CFA
Public Comments on the Proposed Plan .
N/A
N/A, ,-
07120192
PRESS RELEASES
5142
, "
DOE NEWS - Public Comment Period Extended on Proposed Plan for Motor Pool Pond
Sediments at INEL
Cae, M.
N/A
08/05/92
. Docume~t filed in INEL Federal Facility Agreement and Consent Order (FFAlCO) Administr~tive
'. Record Binder
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