EPA/ROD/R10/94/095
February 1995
EPA Superfund
Record of Decision:
Urn at ilia Army Depot (Lagoons),
Operable Unit 4, Hermiston, OR
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DEFENSE ENVIRONMENTAL
RESTORATION PROGRAM
FINAL RECORD OF DECISION
UMATILLA DEPOT ACTIVITY
AMMUNITION DEMOLITION ACTIVITY AREA
OPERABLE UNIT
June 10, 1994
In accordance with Army Regulation 200-2, this document is intended by the Anny to
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Table of Contents
Page
List of Figures and Tables
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. II
Acronyms and Abbreviations. . . . . . . . . . . . . . . . . . . . . . ~ . . . . . . . . . . . . . . . . III
1.0 Declaration of the Record of Decision.. . .. . . . . . . . . . . .. .. .. . . . . . .. 1
2.0 Decision Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7
2.1 Site Name. Location, and Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Site History and Enforcement A~tivities ......................... 10
2.3 Highlights of Community Participation. . . . . . . .. . . . . . . . . . . . . . . . .. 12
2.4 Scope and ~ole of Response Action. . . . . . . . . . . . . . . . . . . . . . . . . . .. 12
2.5 Site Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.5.1 Results of Soil Investigation. . . . . . . . . . . . . . . .". . . . . . . . . . . .. 13
2.5.2 Results of Ground Water Investigation. . . . . . . . . . . . . . . . . . .. 19
2.6 Summary of Site Risks. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
2.6.1 Human Health Risks. . . . ., . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
2.6.2 Environmental Evaluation. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.6.3 Remedial Action Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.7 Description of Alternatives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
2.7.1 Alternative I: No Action. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.7.2 Alternative 2: Containment of Contaminated Soil. . . . . . . . . . . 37
by Soil Cover
2.7.3 Alternative 3: On-Site Treatment of All Contaminated. . . . . . . 37
Soil by Solidification/Stabilization and On-Site Disposal
2.7.4 Alternative 4: On-Site Treatment of All Contaminated. . . . . . . 39
Soil by Both Incineration and Solidification/Stabilization
and On-Site Disposal
2.7.5 Alternative 5: Off-Site Treatment of Hazardous . ...... . . ....40
Contaminated Soil and Off-Site Disposal
2.7.6 Institutional Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2.7.7 UXO Oearance.... ...................................41
2.8 Summary of Comparative Analysis of Alternatives. . . . . . . . . . . . . . . . 43
2.8.1 Threshold Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2.8.2 Primary Balancing Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.8.3 Modifying Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
2.9 Selected Remedy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
2.10 Statutory Determinations. . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . 49
2.10.1 Protection of Human Health and the Environment. . . . . . . . . . . 49
2.10.2 Compliance with ARARs .. . . ., . . . . .. . . . . . . . . . . . . . . . . . . . 50
2.10.3 Cost-Effectiveness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
2.10.4 Utilization of Pennanent Solutions and Alternative. . . . . . . . . . . 51
Treatment Technologies or Resource Recovery Technologies
to the Maximum Extent Practicable
2.10.5 Preference for Treatment as a Principal Element. . . . . . . . . . . . . 51
2.11 Documentation of Significant Changes. . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.0 Responsiveness Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 52
Attachment A - Site Investigation and Assessment Documents. . . . . . . . .. 53
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List of Figures and Tables
Figure
Page. -
1
2
Facility Location Map, Umatilla Depot Activity. . . . . . . . . . . . . . . . . . . . .. 8
Location of Ammunition Demolition Activity Area Sites. . . . . . . . . . . . . .. 9
Table
Page
1
2
. ADA Site Names and General Descriptions. . . . . . . . . . . . . . . . . . . . . . . ., 11
Summary of Contaminants of Concern in Soil at the ADA """""'" 14
3
Summary of Contaminants of Concern in Ground Water at ADA . . . . . . .. 20
Summary of Total Risks and Hazard ,Indices Related to Exposure
to Soil for Current Land Use Scenarios. . . . . . . . . . . . . . . . . . . . . . . . . . .. 24
4
5
Summary of Risks and Hazard Indices Related to Exposure to Soil for
Future Residential Users . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., 26
6
Summary of Risks and Hazard Indices Related to Exposure to Soil for
Future Light Industrial Users. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28
Summary of Risks and Hazard Indices Related to Ground Water
Exposure for Future Residential Users . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 30
7
8
9
Environmental Risk Characterization Summary. . . . . . . . . . . . . . . . . . . . . 32
Risk-Based Remedial Action Criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
10
11
Cleanup Levels for Contaminants at the ADA . . . . . . . . . . . . . . . . . . . . . .. 35
UXO Clearance Levels, Costs, and Access Controls Required. . . . . . . . .. 44
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Acronyms and Abbreviations
ADA
ARARs
Amrnunirion Demolirion Activity Area
BB
BRAC
Applicable or Relevant and Appropriate Requirements
Below Background
Base Realignment and Closure
CFR
Comprehensive Environmental Response, Compensarion, and
Liability Act of 1980
Code of Federal Regulations
CERCLA
c;y
IDD
Cubic Yards
Dichlorodiphenyldichloroethane
DOE
DOT
Dichlorodiphenylethane
Dichlorodiphenyltrichloroethane
2,4-DNT
2,6-DNT
2,4-Di~ttotoluene
2,6-Dinittotoluene
IX>D
FA
Department of Defense
Ecological Assessment
EPA
EPIC
U.S. Environmental Protection Agency
Environmental Photographic Interpretation Center
FFA
HEAST
Federal Facility Agreement
Health Effects Assessment Summary Tables
HI
HMX
Hazard Index
Octahydro-l,3,5,7-tetranitro-l,3,5,7-tetrazOCine (High Melting
Explosive)
HRS
HQ
Hazard Ranking System
Hazard Quotient
IRIS
Ib
Integrated Risk Infonnation System
Pound
!DR
Me..
Land Disposal Restrictions
Maximum Contaminant Level-
III
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Acronyms and Abbreviations (continued)
NCP
Not Analyzed
National Oil and Hazardous Substances Pollution Contingency
Plan
NA
NOB
NEPA
Not Detected Above Background
National Environmental Policy Act
NOAELs
NPL
No Observed Adverse Effect Levels
National Priorities List
NSA
O&M
No Standard Available
OAR
OOEQ
Operations and Maintenance
Oregon Administrative Rules
ppm
Oregon Department of Environmer.:al Quality
Pans Per Million (equivalent tQ Ilg/g and mg/kg)
RA
RAB
Human Health Baseline Risk Assessment
RAC
RCRA
Restoration Advisory Board
Remedial Action Oiteria
Resource Conservation and Recovery Act
RDX
Hexahydro-l.3 .5-trinitro-l.3 .5-triazine (Royal Demolition
Explosive)
Remedial Investigation/Feasibility Study
RIlFS
RME
Reasonable Maximum Exposure
Record of Decision
ROD
SARA
Superfund Amendments and Reauthorization Act of 1986
To Be Considered
TBC
TCLP
TNB
'!NT
Toxicity Characteristic Leaching Procedure
1,3,5- Trinitrobenzene
2,4,6- Trinitrotoluene
mc
Technical Review Committee
Iv
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Acronyms and Abbreviations (continued)
TSDF
UCL
Treatment, Storage, and Disposal Facility
Upper Confidence Limit
UMDA
USAEC
U.S. Anny Depot Activity at Umatilla
U.S. Anny Environmental Center (fonnerly USATIiAMA)
USA'IHAMA
UXO
U.S. Anny Toxic and Hazardous Materials Agency
Unexploded Ordnance
v
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1.0
Declaration of the Record 01 Decision
Site Name and Location
u.s. Anny Depot Activity, Umatilla
Ammunition Detrolition Activity Area Operable Unit
Hermiston, Oregon 97838-9544
Statement of Basis and Purpose
This decision document presentS the selected remedial action for the Ammunition
Demolition Activity Area (ADA) Operable Unit at the U.S. Anny Depot Activity,
Umarilla (UMDA), at HenmstOn, Oregon, which has been selected in accordance with
the Comprehensive Environmental Response. Compensation, and Liability Act of 1980
(CERa..A), as amended by the Superfund AmendmentS and Reauthorization Act of 1986
(SARA), and, to the extent practicable, the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP). The decision is based on the administrative record
for this site. DocumentS supponing the selection of the remedy are identified in
Attachment A to this Record of Decision (ROD).
The remedy was selected by the U.S. Anny and the U.S. Environmental Protection
Agency (EPA). The State of Oregon concurs with the selected remedy.
Assessment of the Site
Actual or threatened releases of hazardous substances from the site, if not addressed by
implementing the response action selected in this ROD, may present an imminent and
substantial endangerment to public health, welfare, or the environment.
Description of the Selected Remedy
The selected remedy for the contamination at the ADA includes the implementation of
actions to (1) clean up chemically contaminated soils; (2) remove unexploded ordnance
(UXO) items from the ground surface; (3) detect and quantify UXO below the ground
surface; and (4) conduct retrieval and treattnCnt of bwied UXO to a depth that will allow
for the selected land use under Base Realignment and Closure. .
The specific steps involved in the cleanup of contaminated soils at the ADA will include:
.
Excavation of approximately 14,000 cubic yards of contaminated soil at five
separate sites at the ADA (Site Numbers 15, 17, 19,31,and32). UXOitems
would be removed from these sites dwing excavation as necessary to pennit safe
excavation and access.
.
Treaanent of contaminated soils by a mobile solidification/stabilization system.
Disposal of the treated soil from the solidification/stabilization system into the on-
site UMDA landfill.
.
.
RestOration of excavated areas with clean backfill and vegetation.
,
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A phased approach will be taken to quantify and reduce risks to the environment and -
human health and safety posed by the presence of UXO. Phase I of this approach will
consist of the following actions:
- .
Conducting a metallic object survey over the entire ADA to obtain a better estimate
of how much metallic debris would have to be removed to clear the ADA of
possible ordnance.
Conducting (concurrent with metallic c;>bject sUIVey) a "visual sweep" over the
ADA to locate and remove objectS identifiable as ordnance.
.
Phase n will consist of the removal of buried meo that is consistent with the future use
selected for the ADA. Prior to the initiation of Phase n. the Anny, EPA, and the Oregon
Depanment of Environmental Quality (ODEQ) will meet to review (1) refmed cost
estimates for clearance of buried UXOs in the ADA and (2) the selected land use decided
under BRAC. The Army. EPA, and ODEQ will make a final decision on the depth of
UXO clearance required to suppon the selected land use. In the event that the Anny.
EP A, and ODEQ cannot reach an agreement. the decision will be subject to the provisions
of the Umatilla Federal Facilities Agreement (FFA), including dispute resolution.
. Providing an agreement is reached. the initiation of Phase n is planned within 15 months
after a final land use deciSion has been made. .
Following the actions described above to clean up contaminated soil and detect and
remove UXO. institUtional cOntrols will be applied to the ADA to permanently control
access to, and use of, the ADA consistent with the final use selected.
Statutory Determinations
The selected remedy is protective of human health and the environment. complies with
federal and state requirements that are legally applicable or relevant and appropriate to the
remedial action, and is cost-effective. This remedy utilizes permanent solutions and
alternative treatment teChnologies to the maximum extent practicable, and satisfies the
statutory preference for remedies that employ treatment that reduces toxicity, mobility. or
volume as a principal elemenL
The cleanup levels, listed herein, for chemically contaminated soil are proteCtive to allow
for possible future industtial use. However. the continued presence of meo will require
that institutional controls be implemented at the ADA to restrict access and future use. In
order to ensure that this cleanup remtdy continues to be protective, a site review will be
conducted every five years. This review will include verifying that institutional controls
remain in place and that land use of the ADA has not changed.
2
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Lead and Support Agency Acceptance of the Record of Decision
U.S. Army Depot Activity UmatUia
Ammunition Demolition Activity Area Operable Unit
Signamre sheet for the foregoing Record of Decision for the Ammunition Demolition
Activity Area Operable Unit final action at the U.S. Army Depot ACtivity at UmaDlla
betWeen the U.S. Army and the United States Environmental ProteCtion Agency, with
concurrence by the Swc of Oregon Deparunem of Environmcntal Quality.
~ ~,W~
Lewis D. Walker
Deputy AssiSt311t Secretary of the Anny
(Environment. Safety. and Occupational Health)
!{] 1)/'1,/
3
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Lead and Support Agency Acceptance of the Record of Decision
U.S. Army Depot Activity Umatliia
Ammunition Demolition Activity Area Operable Unit (Cont'd)
Signature sheet for the foregoing Record of Decision for the Ammunition Demolition
Activity Area Operable Unit fmal action at the U.S. Anny Depot Activity at Umatilla
betWeen the U.S. Anny and the United States Environmental Protection Agency, with
concurrence by the State of Oregon Department of Environmental Quality.
~JJ1JJ1I<~
Lieutenant Colonel Moses Whiteh 1, Jr.
Commander, U.S. Anny Depot Activity, Umatilla
~2tj
4
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Lead and.Support Agency Acceptance of the Record of Decision
U.S. Anny Depot Activity Umatilla
Anununition Demolition Activity Area Operable Unit (Cont'd)
Signature sheet for the foregoing Record of Decision for the Ammunition Demolition Activity
Area Operable Unit final action at the U.S. Army Depot Activity at Umatilla between the U.S.
Army and the United States Environmental Protection Agency, with concurrence by the State
of Oregon Department of Environmental Quality.
~ B "'3"~L, ~&t
Date
4a
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Lead and support Agency Acceptance of tne Record of Decision
U.S. Army Depot Activity UmatUla
Ammunition Demolition Activity Area Operable Unit (Cont'd)
Signature sheet for the foregoing Record ofDccision for the Ammunition Demolition
ACtivity Area Operablc Unit fin:11 action at the U.S. Army Depot Activity a.t Urn:nma
betWeen the U.S. Army and the United States Environmental Protection Agency, with
concum:ncc by the State of Oregon Department of Environmental Quality.
~~
Cluck Oarkc
Regional AdminisUAtor. Region X
U.S. Environmental Protection Agency
;z,1 f(; / t; V
Dale .,
5
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Lead and Support Agency Acceptance of the Record at Decision
U.s. Army Depot ActiVity UmatUia
Ammunition Demolition ActivIty Area Operable Unit (Cont'd)
SigIWUrC sheet fer the foregoing Record of Decision for the Ammunilion Demolition
ACtivity Area. Operable Unit fiDa1 action at tbe U.S. Am%y Depot Acti~ at U,""ri11:t
berween the U.S. Army and tbe United States Environmental Protection Agency, with.
COllCUn'Cnce by the State of Oregon Depanmcnc ofEnvironmenw Quality.
~~~
'JUL 2 6 19~4
Dale
Fred. }lJln~
Director, Oregon Depdua..ur of Envinmmenw Quality
Ncxe: The Swe of Oregan)s I..caer of ConaIm:Dcc is appcDded II) rbia Rcccrd of I>
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2.0
Decision Summary
1bis Decision Summary provides an overview of the problems posed by the conditions at
the UMDA ADA, the remedial alternatives, and the analysis of those options. It explains -
the rationale for the remedy selection and describes how the selected remedy satisfies
statutOry requirements.
2.1
Site Name, Location, and Description
UMDA is located in northeastern Oregon in Monow and Umatilla Counties,
approximately 5 miles west of Hermiston, Oregon, as shown in Figure 1. The installation
covers about 19,700 acres of land. The ADA is located in the nonhwesteID ponion of
UMDA. This approximately 1,750-acre area contains 20 individual sites that have been
identified as areas of histOrical or current Anny activities. The locations of these sites are
presented in Figure 2.
The region surrounding UMDA is primarily used for iIrigated agriculture. The population
centers closest to UMDA are Henniston (population 10,075), approximately 5 miles east;
Umatilla (population 3,032), approximately 3 miles northeast; and Irrigon (population
820),2 miles nr"thwest The total populations of Umatilla and Morrow Counaies are
approximately 59,000 and 7,650, respectively.
Nonheastem Oregon, the setting for UMDA (and the ADA), is characterized by a semi-
arid, cold desen climate, an average annual precipitation of 8 to 9 inches, and a potential
evapo-transpiration rate of 32 inches. The installation is located on a regional plateau of
low relief that consists of relatively permeable glaciofluvial sand and gravel overlying
Columbia River Basalt.
Ground water at UMDA occurs primarily in tWO settings: in an unconfined aquifer within
the overlying deposits and weathered basalts, and in a vertical sequence of semi-confined
and confined aquifers within the basalt Regional flow gradients in the uppennost
unconfined aquifer are influenced by irrigation, pumping, and leakage from irrigation
canals. Ground water flow directions in this aquifer reverse seasonally in response to off-
post pumping and recharge activities. During the summer and early fall, flow is tOward
the east and south as irrigation activities peak. During the winter and early spring, when
irrigation activities are at a minimum, ground water flow is to the nonh and west
Approximately 1,470 wells have been identified within a 4-mile radius of UMDA, the
majority of which are used for domestic and irrigation water. Three municipal water
systems (Hermiston, Umatilla, and Irrigon) draw from ground water within a 4-mile
radius of UMDA.
The Columbia River flows from east to west approximately 3 miles to the nonh of the
UMDA boundary, and the Umatilla River flows from south to nonh approximately I to 2
miles to the east. The Columbia River is a major source of potable and irrigation water,
and is also used for recreation. flShing, and the generation of hydroelectric power. The
principal use of the Umatilla River is irrigation. No natural streamS occur within UMDA;
the facility is characterized by areas of closed drainage.
The topography of the ADA is relatively flat with occasional gently rolling hills or ridges.
Elevations are in the range of approximately 460 to 580 feet above mean sea level. Soils
at the ADA sites typically consist of fine- to medium-grained sand. Vegetation is ~
relatively sparse, consistent with the UMDA installation in general. Depths to ground
water at the ADA sites are in the range of approximately 60 to 100 feet below the ground
smfa~. .
7
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"" I
" '
... I
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~ 'l~~'e~tJ)
Yakima Counly ~.~:SI Rlchlan
I
.'-'-'-'_'-0_0- i
o_0--t
I
Benton ~unty
KJickJlal County
C»
-~ .,~.,~
, -~ \1 UMDA Site
r't
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i \.\ ",..,
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Monow County
Gilliam County
. Source: Arthur D. Little. Inc., 1993. Fig. 1
. )l I
Flanklln County \ ~. "
1,0'" .
Pasco {J .)~"J~~... L.., .'
~. f. "" ( ..........,y
--\\'\ . I
I~~ --. '
Walla Walla County 1
.~ ,: I
rv..., ; ."- . Walla Walla i
...-A../ ". WAS
.._.._.._.._';:-~. . HINGTON
< ._..-OREGOOu"
~~~~!¥.I.U' m.." " I
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,
.
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UmaUlia County
...
N
0 10 20
Scale In Miles
Figure 1
Facility Location Map'
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NCrtft ao."n.oO"'" P":!tr'Ol Foo
I
o
,
800
HCnE: SiI8 - - ...... UIn9
- , "..1 OJ. of - ...... ~ ~
CIIe ... - - for ... - .... -
-'" ---
Location of ADA Sites
Figure 2
JAN. 1994
SrTE...loc.DWG
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2.2 Site History and Enforcement Activities
UMDA was established as an Anny ordnance depot in 1941 for the purpose of storing
and handling munitions. Access is currently restricted to installation personnel and
authorized contraCtors and visitors. UMDA is included in the Department of Defense
(DoD) Base Realignment and Qosure (BRAC) program which requires that the
conventional ordnance storage mission be transferred to another installation. In view of
the DoD's initiatives to promote early reuse of closing installations, property transfer of
UMDA (and the ADA) could occur in the future.
Since 1945, the ADA has been used by the Anny to dispose of ordnance and other solid
wastes by burning, detonation, dumping, or burial. Activities were conducted at a
number of locations throughout the ADA. Twenty sites have been identified as actual or
possible locations of Army activities at the ADA. Specific charaCteristics of these 20 sites
at the ADA are presented in Table 1.
In addition to possible chemical contamination at these 20 sites, ADA activities also
resulted in the presen~e of unknown quantities of UXO at unknown locations across the
entire ADA.
An initial installation-wide assessment was perfonned in 1978 and 1979 to evaluate
environmental quality at UMDA with regard to the past use., storage, treatment, and
disposal of toxic and hazardous materials. Based on aerial imagery analysis provided by
EPA's Environmental Photographic Interpretation Center (EPIC) as part of the
assessment, the UMDA was charaCterized as containing potentially hazardous sites. In
1981, Battelle conducted an Environmental Contamination Survey and Assessment at
UMDA. This survey and assessment included ~he sampling and analysis of soils and
ground water across UMDA (including the ADA). Also in 1981, the U.S. Anny
Environmental Hygiene Agency conducted a Hazardous Waste Management Study at the
ADA in which they sampled and analyzed soils at a limited number of locations at the
ADA. An additional assessment was perfonned in 1988 by Weston in which soil and
ground water sampling and analysis were perfonned at a number of the ADA sites.
In 1984, an evaluation of the Explosives Washout Lagoons (a contaIninated area located
within UMDA but outside of the ADA) was perfonned using EP A's Hazard Ranking
System (HRS). Based on the results of this evaluation, the lagoons were proposed for
inclusion on the National Priorities List (NPL) on October 15, 1984. They were formally
listed on the NPL on July 22, 1987 based on the HRS results as well as the results of the
installation Resource Conservation and Recovery Act (RCRA) Facility AssessmenL
On October 31, 1989, a Federal Facility Agreement (FFA) was executed by UMDA, the
Army, EPA Region X, and the Oregon Department of Environmental QualitY (ODEQ).
The FFA identifies the Army as the lead agency for initiating response actions at UMDA.
One of the purposes of the FF A was to establish a framework for developing and
implementing appropriate response actions at UMDA in accordance with CERCLA, the
NCP, and Superfund guidance and policy. A remedial investigation (RI) and feasibility
study (FS) of the entire UMDA installation, including the ADA, was initiated in 1990 to
detennine the nature and extent of contamination and to identify alternatives availabJe to
clean up the facility.
10
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Table 1: ADA Site Names and General Descriptions
Dp<;C'rintion
Small fenced area reportedly used to dispose of
aniline (a missile fuel componem)
Small pit reportedly used to dispose of red fuming
nitric acid
Long, narrow mound in which tlebris from smoke
canister burning operations was found
Mound of soil containing debris from flare and
fuse burning operations .
15 TNT Sludge Burial and Burn Area Sludges from Explosives Washout Plant and/or
other wastes reponedly dumped at this site
Rows of pits in which conventional munitions have
been. and are currently being detonated
Area used for the detonation of decomaminated
. rockets and land mines
Several historical pits reponedly used to dispose of
and bum dunnage, liquid wastes, and sludges
Row of trenches and a bum field area reponedly
used to bum explosives sludges and other wastes
Sheds used to store missile fuel components
Several pits reportedly used to bum or dispose of
pesticide solutions
Two areas currently in use to conduct permined
open burning operations
Several rows of pits that were reponedly used 10
explode and dispose of old or faulty ordnance
41 Chemical Agent Decomamination Trench and pit suspected to have been used as a
Solution Burial Area burial area for chemical agent decontamination
solutions
Several rows of apparent bum trenches - specific
operations that occurred there are unknown
Circular area reponedly used to bum empty
wooden crates
Three areas containing pits - specific operations
J
that occurred there are unknown
Area showing signs that burning operations may
. have been conducted there
Pits suspected to have been used as a disposal area
for chemical agent decontamination solutions~
18-acre site currently in use by the National Guard
as a rifle. machine gun. and grenade firing range
Site N_!lmher/Name
7 Aniline Pit
8
Acid Pit
13 Smoke Canister Disposal Area
14 Flare and Fuse Disposal Area
16 Open Detonarion Pits
] 7 Aboveground Open Detonalion
Area
] 8 Dunnage Pits
19 Open Burning TrencheslPads
21 Missile Fuel Storage Areas
31 Pesticide Pits
32 Open Burning Trays
38 Pit Field Area
55 Trench!Burn Field
56 Munitions Crate Bum Area
57 Former Pit Area Locations
58 BorrowlBum/Disposal Area
59 Chemical Agent Decontamination
Solution Disposal Areas
60 Active Firing Range
1 1
;m.d"t'UIo .
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An extensive sampling and analysis program was initiated at the ADA as pan of the RI .
cond\lcted by Dames & Moore. This investigation included the assessment of soil
contamination at each of the 20 ADA sites as well as an overall assessment of potential
ground water contamination beneath the ADA. In addition, this investigation included the
evaluation and summary of the prior investigations conducted at the ADA. Soil and
ground water characterization data developed during these investigations were used to
develop a human health baseline risk assessment, completed in 1992. Based on
infonnation developed in the RI (including the Risk Assessment), a feasibility study of
cleanup actions at the ADA was completed in 1993.
A list of documents that outline the results of the site investigations and assessments of
cleanup actions for the ADA is provided as Attachment A to this ROD.
2.3 Highlights 01 Community Participation
In 1988, UMDA assembled a Technical Review Comminee (TRC) composed of elected
and appointed officials and other interested citizens from the surrounding communities.
In December 1993, the TRC was converted to a Restoration Advisory Board (RAB).
Quarterly meetings provide an opponunity for UMDA to brief the RAB on installation
environmental restoration projects and to solicit input from the RAB. Three RAB
meetings were held during preparation of the supplemental investigation and feasibility ,
study for the ADA Operable Unit In those meetings, the RAB was informed as to the
scope and methodology of the investigation and cleanup.
The Feasibility Study and Proposed Plan for the ADA Operable Unit were released to the
public on February 15, 1994. The public comment period started on that date and ended
on March 17, 1994. Documents relative to the RI and the FS were made available to the
public at the following information repository locations: UMDA Building 32, Hermiston,
Oregon; the Hermiston Public Library, Henniston, Oregon; and the EP A offices in
Ponland. Oregon. The notice of availability of the Proposed Plan was published in the
Hermiston Herald, the Tri-City Herald, and the East Oregonian in February 1994.
A public meeting was held at Armand Larive Junior High School, Hermiston, Oregon,
on March 2, 1994, to inform the public of the preferred cleanup alternative and to seek
public comments. At this meeting, representatives from UMDA, the U.S. Anny
Environmental Center (USAEC), EPA, ODEQ, and Anhur D. Little, Inc. (an
environmental consultant to USAEC) answered questions about the site and remedial
alternatives under consideration. A response to comments received during this period is
included in the Responsiveness Summary in Section 3.0 of this ROD.
2.4 Scope and Role 01 Response Action
Response actions are discrete actions that constitute incremental steps toward a final
overall remedy. They can be actions that completely address a geographic portion of a site
or a specific problem. or can be one of many actions that will be taken at the site. At
UMDA, response actions are directed at eight areas identified as operable units based on
the results of the RI. These operable units include:
.
Inactive Landfills
Active Landfill
Explosives Washout Lagoon Soils
Explosives Washout Lagoon Ground Water
.
.
.
12
-------
.
-Explosives Washout Lagoon Plant
Deactivation Furnace (and surrounding soils)
. Ammunition Demolition Activity Area (ADA)
Miscellaneous Sites
The ADA Operable Unit, a 1,7 50-acre area located in the nonhwest comer of UMDA,
contains 20 sites with varying degrees of possible contamination. In addition, UXO are
potentially present across the entire ADA (UXO are not limited to the 20 defined sites).
The threats described in this ROD are those associated with contaminated soil at these
sites and the presence of unknown quantities of UXO at unknown locations throughout
the ADA. The cleanup sttategy presented in this ROD includes an action for soil in
addition to a specified degree of removal of UXO from the ADA.
2.5 Site Characteristics
The sources of contamination at the ADA are activities associated with the disposal of
ordnance and other solid wastes by burning, detonation, dumping, or burial. (Refer to
Table 1 for a general description of each of the 20 ADA sites.) The types of
contamination include:
~.
'"
.
Explosives (contained in ordnance or other wastes disposed of)
Metals (contained in ordnance and munition casings being burned, detonated, or
disposed of)
Pesticides (through application or disposal)
UXO and related metallic debris
..
£]
.
.,
.
.
2.5.1 Results of 5011 Investigations
Several soil investigations have been conduCted at the ADA since 1981. Samples
collected from surface soils and from soil borings have been used to detennine the
vertical and horizontal extent of soil contamination. Investigation results are presented in
Table 2. In identifying these contaminants, it was assumed that soil at depths greater than
10 feet would not be available for exposure; therefore, only soils collected from 10 feet or
shallower were included in the analysis of investigation results. The contaminants
presented in Table 2 are those that were positively deteeted in at least one sample and
were found to be present in concentrations greater than naturally occurring background
concentrations. For reference, Table 2 includes measures of the average contaminant
concentration (to depths of 2 feet and 10 feet) and the frequency at which the contaminant
was detected at those depths. The total volume of soil affected by the contaminants as
presented in Table 2 is roughly estimated at more than 33,000 cy. As can be seen in
Table 2, no contamination was detected in soils at Sites 7, 58, and 59.
i~i
. ... .0;'
. .... --"~
-
. .' ..
. ~.- ....,
.. ~ .
In the course of conducting the soil investigations, clearance of UXO was perfonned to
ensure safe access by people collecting chemical samples. Approximately 80 UXO were
foun~ as well as an extensive amount of inert metal debris. The total area cleared was
small (less than 100 acres) compared to the entire ADA, but involved the areas most
likely to have UXO. Because this clearance included only a small area. the total
quantities, locations, and depths of UXO in the ADA are not well defined.
In general, the chemical contaminants in soil at the ADA can be characterized as haVing
relatively low aqueous solubilities and low volatilities. Potential routes for their migration
include the following: .
13
-------
Table 2: Summary 01 Contaminants o' Concern In Soil at the ADA
Site
7
Contaminant
of Concern
None
8
Lead
Nickel
Zinc
13
Aluminum
Antimonv
Arsenic
Coooer
Iron
Lead
Manoanese
Mercury
Nickel
Silver
Zinc
2,6-0NT
14
Barium
Chromium (b)
Lead
Potassium
Silver
Zinc
NitriteJNitrate
. ..
15
Antimonv
Arsenic
Barium
Bervtlium
Cadmium
Chromium (b)
Cobalt
Coooer
Iron
Lead
Maanesium
Mercurv
N"1CkeI
Potassium
Selenium
Silver
Sodium
Thallium
Zinc
1.3,S-TNB
2.4.6- TNT
HMX
ROX
NilratelNitrite
Background
Concentration
ppm (8)
...
8.37
12.6
94
8604
3.8
5.24
58.6
26233
8.37
874
0.056
12.6
0.038
94
NSA
233
32.7
8.37
2179
0.038
94
9.9
.. .
3.8
5.24
233
1.86
3.05
32.7
15
58.6
26233
8.37
8585
874
0.056
12.6
2179
0.25
0.038
978
31.3
94
NSA
NSA
NSA
NSA
9.1
To a Depth of 2 Feet
95% UCL Frequency
Concenb'8t1on of
ppm Detection
NOB
.....
NOB
16.1
14.4
778
103653
321
774
0.512
85.7
6.05
26S68
0.831
: ~'."'.- ','.',"
..
3n
188
330
2320
0.062
1710
NOB
3396
20
7781
12.9
2935
7160
239
3120
130000
695
16199
1881
0.201
306
3740
5.57
2.17
2094
708
22813
1.42
176
28.6
126
81
14.
NA
NA
NA
10f5
50f5
30f5
50f5
50f5
50f5
4015
20f 5
50f5
50f5
1015
...'
.. ...
1 of 2
1 of 2
20f 2
2012
1 of 2
2012
3014
40f4
20f4
2014
2014
3014
20f4
30f4
4014
40f4
40f4
4of4
1 of 4
30f4
40f4
20f4
30f4
40f4
20f4
40f4
10f4
10f4
1 of 4
20f4
20f2
To a DeDth of 10 Feet
95% UCL Frequency
Concentration of
DDrn Detection
NOB
18.7
15.2
3796
7268
6.08
7.85
297
49282
98.8
659
0.201
40
1.93
9611
0.429
. .
.... .
289
48.7
86.2
1867
0.03
459
11.3
832
10.6
2~18
4.98
1057
1937
80.2
936
63112
220
10369
1070
0.071
103
2112
1.165
0.772
1153
250
7229
0.549
48.6
7.82
34.8
26.9
4014
4014
2014
1501 15
1 0115
150115
40f 15
150115
150115
150115
40115
40115 -
70115
150115
10115
. "','
..
1001 12
10112
120112
120112
30112
100112
10 of 12
....
40114
140114
11 of 14
30114
40114
60114
40114
40114
14 of 14
1401 14
14 of 14
14 of 14
20114
40114
14 of 14
30114
6 of 14
1401 14
3 of 14
14 of 14
2 of 14
2 of 14
3 of 14
8 of 14
5 of 10
-------
Table 2: Summary of Contaminants of Concern in Soil at the ADA (continued)
I To a Depth 01 2 Feet To a Depth of 10 Feet
Background 95% UCL Frequency 95% UCL Frequency
Contaminant Concenntion Concentration of Concentration of
Site of Concern DDIn fa) ppm Detection DDm Detection
! 16 Arsenic 5.24 NOB 8.59 45 01 45
I Barium 233 427 5015 257. 44 01 45
Cadmium 3.05 3.31 1 of 5 1.69 1 of 45
I Cobalt 15 19 1 of 5 8.58 1 of 45
Coooer 58.6 118 2 of 5 102 45 of 45
Silver 0.038 1.49 40f5 0.274 26 of 45
Zinc 94 NOB 542 45 of 45
Cyanide 0.92 1.14 lof5 0.612 4 of 45
1,3.5.TNB NSA NA 0.935 10f45
2.4.6-TNT NSA 1.07 30f5 6.81 6 of 45
2,4-0NT NSA NA 0.232 1 of 45
HMX NSA NA 0.365 1 of 45
: Nitrobenzene NSA NA 1.58 1 of 45
ROX NSA 1.32 2 of 5 0.949 8 of 45
i Nitrite/nitrate 9.9 15.6 5 of 5 4.31 37 01 45
I .. .... ... ,.....' . ",",',",',",
I 17 Antimonv 3.8 85 20f4 NA
I Bervllium 1.86 3 1 of 4 NA
Cadmium 3.05 5.25 1 of 4 NA
Cobalt 15 23.7 lof4 NA
Coooer 58.6 299 10f4 NA
Iron 26233 69158 40f4 NA
Lead 8.37 1460 40f4 NA
Nickel 12.6 27 1 of 4 NA
Sitver 0.038 0.138 30f4 NA
Sodium 978 948 40f4 NA
Zinc 94 118 40f4 NA
2.4.6- TNT NSA 3.01 lof4 NA
HMX NSA 1.69 20f4 NA
ROX NSA 12 30f4 NA
I ... .. . .',':',';
.. '.... .. .
18 Aluminum 8604 2994S 40f4 14059 28 of 28
Alseni: 5.24 6.19 40f4 10.5 28 of 28
Barium 233 462 40f4 1526 28 of 28
IBervllium 1.86 NA 2.34 3 of 28
Cadmium 3.05 NA 3.95 40f28
Chromium lb) 32.7 80.6 lof4 22.7 60128
Cocoer 58.6 100 1 of 4 741 70f28
Iron 26233 NDB 33861 28 of 28
Lead 8.37 273 4014 266 28 of 30
58 874 1620 4014 782 28 of 28
NieMI 12.6 389 lof4 63.5 7 of 28
Silver 0.038 1.68 20f4 0.637 17 of 28
Socium 978 3073 40f4 1544 28 of 28
Dieldrin NSA NA O.oos 1 of 28
DDE NSA NA 0.006 3 of 28
DDT NSA NA 0.01 5 of 28
"
..-., "I
~ 1,1
15
-------
Table 2: Summary of Contaminants of Concern In Soli at the ADA (continued)
Site
19
Contaminant
of Concern
Aluminum
Antlmonv
Arsenic
Barium
Cadmium
Chromium (b\
Coooer
Lead
Mercurv
Nickel
Potassium
Silver
Sodium
Zinc
1,3,5.TNB
2,4,6- TNT
2,4-DNT
2.6-DNT
HMX
Nitrobenzene
RDX
Nitrate/nitrite
21
I Lead
I Nitrate/nitrite
31
Barium
Coooer
Iron
Lead
Mercurv
Nickel
Silver
Sodium
Zinc
1.3.5-TNB
2.4.6- TNT
2.4-DNT
2.6-DNT
RDX
Tetrvl
Nitrate/nitrite
Trichioroethvten4
XVlenes
2-MethvlnaDthah
Phenanthrene
Dieldrin
ODD
DOE
DOT
Endrin
Background
Concentration
DDm (8)
8604
3.8
5.24
233
3.05
32.7
58.6
8.37
0.056
12.6
2179
0.038
978
94
NSA
NSA
NSA
NSA
NSA
NSA
NSA
9.9
..... .
I
. ",..
233
58.6
26233
8.37
0.056
12.6
0.038
978
94
NSA
NSA
NSA
NSA
NSA
NSA
9.9
NSA
NSA
NSA
NSA
NSA
NSA
NSA
NSA
NSA
To a Depth of 2 Feet
95% UCL Frequency
Concentration of
ppm Detection
25557 4 01 4
3128 4 01 4
244 4014
25678 4 01 4
641 3 of 4
43.9 3 of 4
109139 40f4
3908 4 of 4
3.11 2 0' 4
43.2 3 of 4
3610 40'4
3.4 30f4
1160 40'4
211239 40f4
143 20f4
36045 3 of 4
NA
NA
NA
3.23
NA
11.2
. .... ...
. ... ,'"'''' . ..
...........,.............
,......."",,,,,,,,,, ...
...... .................. .
.".',"..".',"..,".'.",".".'.',",."'." " ,'..
8.3n
9.91
. .
1 of 4
40f4
40f4
40f4
20f4
40f4
40f4
10f4
20f4
1 of 4
20f4
1 of 4
40f4
1 of 4
1 of 4
10f4
20f4
10f4
16
To a Depth of 10 Feet
95% UCL Frequency
Concentration of
ppm Detection
8344 44 of 44
231 4 of 44
21.6 44 of 44
2195 44 of 44
48.7 30f44
10.7 4 of 44
7908 40144
325 44 01 44
0.247 2 of 44
11.7 12 01 44
2544 44 01 44
0.356 10 of 44
599 44 of 44
15685 400144
12 60148
2376 8 of 48
1.39 10148
0.87 1 0148
3.75 40f48
7.67 20f48
35 50f48
13 180148
..
.. ..
NDBI
14.91 4 of 6
:':'::'''''i''',,~
315 4014
NA
55390
39
NA
NA
0.461
29731
554
16
2180
2.08
NA
3.08
2.07
46.2
NA
NA
NA
0.45
0.083
0.083
0.518
0.423
NA
.. ..
. "".
160
6695
23117
9.02
0.066
22.2
0.139
5180
138
1.66
197
0.38
0.135
0.548
0519
54
0.014
0.002
0.155
0.153
1.71
0.014
0.051
0.042
0.005
..... P.
..
121
8.71
5015
4 of 10
.:.:;..:.",
35 of 35
100143
35 of 35
41 of 43
1 01 43
10 of 43
80143
35 01 35
40 of 43
10135
20f35
1 of 35
1 of 43
20f35
1 of 35
27 of 43
20f42
20f34
1 of 35
30f43
30f35
2 of 35
4 of 35
2 of 35
1 of 35
-------
. ,
Table 2: Summary 01 Contaminants 01 Concern In 5011 at the ADA (continued)
Site
32 (Area I)
32 (Area II)
41
55
56
38
Contaminant
of Concern
Copper
Lead
Potassium
Silver
Zinc
2.4-ONT
Nitrate/nitrite
Aluminum
Antimonv
Barium
Cooaer
Lead
Maanesium
Potassium
Silver
Zinc
2.4-0NT
Ni1ra18/nitrite
Coooer
Iron
MeraJrv
Nickel
Potassium
Silver
Zinc
Nitrobenzene
2.4.6- TNT
Tetrvl
Antimonv
Lead
Zinc
.. .
.. .....
IHMX
IROX
.. ..
BervUium
Lead
MaQnesium
57 (Area J)
'::::;:';':'.; ;:::~:::::::::;:::::.:'::::
",,',",",",",--,".".".".".."".",".",",".'.".'"."
Lead
Mercurv
Potassium
Zinc
Background
Concentrlltlon
ccm (8)
58.6
8.37
2179
0.038
94
NSA
9.9
8604
3.8
233
58.6
8.37
8585
2179
0.038
94
NSA
9.9
....-
58.6
26233
0.056
12.6
2179
0.038
94
NSA
NSA
NSA
To 8 Depth of 2 Feet
95% UCL Frequency
Concenttation of
CDm Detect/on
304 1014
177 4014
4045 4 01 4
0.104 4014
1030 4014
1.33 3 01 4
28 4 of 4
To 8 DeDth of 10 Feet
95% UCL Frequency
Concentrlltion of
ccm Detection
NA
NA
NA
NA
NA
NA
NA
.."
.. ...." .
...............". ...'"
..........,...,-..... ..
._,"...."".,....,...,''''''''''
h. ..n',",""'''''''''', ..
..........d... -'"''''''''''''
.....................-.. - .. -.'"
9967
30.6
23274
5133
1263
16820
2487
631
741
1.61
26
. .
4014
2014
4014
30f4
4014
4014
4014
30f4
4014
1014
4014
.................... n. ....
.......................... .-
"',"..",',',",','.',',',','.',',',',',',','.'.'.'c,'-',',',',',',',',',',',",c.'...'.',',',',,'.'c
, """"""",'","',.'" ,."",. ,..."." '
",'c'.",',',','.'"",'.',',',','.',','.','...',".',"c" """.',',",",
, .,. ", ..,.
..
."
..
4270 1 of 10 831
28363 10 of 10 24518
0.237 1 of 10 0.065
20.4 2 of 10 9.64
2207 10 of 10 1818
0.056 '5 of 10 0.032
2752 100110 965
NA 1.31
0.381 1 0110 2.71
NA 0.452
.. .
...
'.
:::::':":::::::::::;::':::::J{~::::~:~:t;::::;~::;;:'::::.;:~:':::}::~:~:;:~:~:~:;:;:~:~:~:~:t~;::~~~:~:~;::t;:~:::::(::':~:::::~:::':::}:;~;~:~:~:::~:r~:;:::
. .
.. .
3.8
8.37
94
.'
I
NSAI
NSA
,"""""''''''
..., ., .."
1.86
8.37
8585
, ,.. ........ '
" ..'.',','.".',".'.','.....','.',','.'.'.',',','.'.'-'.','.".'
. . . ""',...'""""""", ,....
, ' . ,.. ,., .', c. .'.' :.:.:.:~...:~;.:,;.:::,:::.::;::::,:.;::::.:~:.;.:,;,.::..; ;'. ':'
8.37
0.056
2179
94
8.41
16.3
99.5
7.31 6 of 10
11.2 1001 10
132 1001 10
1.031 2 of 12
1.42 4 of 12
....., "
1.85 1 016
7.86 6016
8936 6016
20f 2
20f2
20f2
NAI
NAI
, ,." , ,
... ................, .
..,... .........,'.,..".' .,.""
.,..,..."..."..'.,..,....... "
....,'...,...,.......,....,....
"""...,.,"""""""" .
.... ..,',.............,..
..,........."..........'. ,
2.76
10.3
NOB
. , .. ,. , '
"" ,.... " ,..
.....,...,' ....
."..."'.'.', ,..".
.......
lof3
30f3
.....
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
..
3 of 50
50 01 60
1 of 50
3 of 50
50 of 50
25 of 50
50 01 50
1 of 50
6 01 50
2 of 50
....
.......
......
,.......
. . :' ::::;: :;:~:::~~:t~~:~::~~~~~~rt~~:~irf~:~;~:::::~:::~::~:::\~::~:t:{;~;:;::t:f::~:::;;:r::~:::::f::~~;::;~:::;::;;:;?trr~::;;:}:::;:: ::::;';';':" '.' , ,'.'. . . . . .
45.6
0.137
2240
163
17
1 of 1
1 of 1
1 of 1
1011
11.8
0.D43
1543
74.5
170117
1 of 17
170117
140117
-------
Table 2: Summary 01 Contaminants 01 Concern In Soil at the ADA (continued)
i To a DeDth 01 2 Feet To a Deoth 0' 10 Feet
I Background 95% UCL Frequency 95% UCL Frequency
Contaminant Concentration ConcentrBtJon 0' Concentration 0'
Site of Concern ODm (a) Dom Detection ODm Detection
57 (Area II) Copper 58.6 127 10t3 40.8 1 ot23
Lead 8.37 170 30t3 24.8 23 01 23
Mercurv 0.056 5.1 30t3 0.816 30t23
Nickel 12.6 23.5 10t3 8.33 1 ot 23
Potassium 2179 2360 30t3 1673 23 ot 23
Silver 0.038 0.459 30'3 0.069 60t23
Zinc 94 390 30t3 105 21 ot 23
Tetrvl NSA 2.02 1 ot 3 0.561 1 ot23
...... -,_.
57 (ArealU) Cadmium 3.05 5.82 10t8 2.31 1 ot 40
Copper 58.6 181 10t8 57.1 1 ot 40
Lead 8.37 149 80f8 30.9 40 of 40
i Mercurv 0.056 0.058 1 ot 8 0.031 1 of 40
Potassium 2179 2073 80t8 1415 40 ot 40
i Silver 0.038 199 80f8 36.4 150140
Zinc 94 5870 80f8 1137 40 of 40
2.4.6- TNT NSA NA 0.268 1 of 40
......... .. .. ...,.,.......,.."...c.."..,.<.,:. ...:,.;:-. ", ~"'.
58 INane I ." NDBI I .NAI
.....,.' .... ... .. ..... . ... . n., '.. '.."....',0.:':. .. ...
"....
59 I None I NDBI NA
....'...'..;''''..:'.,.;:::."",..... ...c'"..''''' .,.,...,
60 I Lead I 8.37 11.4 30t3 NA
I Silver 0.038 0.0481 30f3 NA
Notes:
ppm - Parts per million
UCL - Upper Confidence Umit
NDB - No samples detected aboY8 background
NA - Not analyzed at this depth
NSA - No standard available
(a) . Background concentration as established in RemediallnYastigation
(b) - Total chromium .
18
-------
Air
Airborpe transpon of soil contaminants is the most likely route of contaminant migration
at the ADA. This might occur via the dispersion of soil particles by wind or soil
disturbances caused by hwnan activity at the contaminated ADA sites. Passive ttanspon
of soil contaminants is unlikely given their low volatility.
Surface Water
There is little potential for surface water transpon of the contaminants at the ADA. The
ADA is not located within a floodplain nor is there run-on or run-off from the ADA. The
low precipitation rate and high soil permeability allow for ready percolation of any rain
falling directly onto the ADA soil.
Subsurface
Infiltration of precipitation provides a potential subsurface pathway for migration of
contaminants in soil at the ADA. However, the rate of tranSpott is expected to be low due
to the low precipitation and high evaporation rates in the region. The depth to ground
water at the ADA (typically in excess of 60 feet), combined with the low rate of
n-anspon of contaminants through the subsurface soils, makes ground water
contamination due to the migration of contaminants at the ADA unlikely.
2.5.2 Results 01 Ground Water Investigation
During the RI, sampling and analysis of ground water was perfonned at selected sites (or
groups of sites) to identify potential ground water contamination beneath the ADA.
Investigation results are presented in Table 3. The contaminants presented in Table 3 are.
those that were positively detected in at least one sample and were found to be present in
concentrations greater than naturally occmring background concentrations. For
reference, this table includes measures of the average concentration and the frequency at
which the contaminants were detected.
Despite the presence of inorganic elements or compounds in the ground water beneath the
ADA, there is no evidence that migration of contaminants in soil was, or in the future
would be, responsible for ground water contamination. This finding is supponed by the
general absence of any specific correlation between the contaminants of concern in soil
and ground water as well as the lack of evidence that contaminants of concern in ground
water have any relation to activities performed at the ADA.
For the most part, contaminants of concern in ground water at the ADA are those that
were identified in background ground water characterizations. These inorganics were
consistently identified across the entire installation and were not resuicted to the ADA.
2.6
Summary of Site Risks
This section sununarizes the human health risks and environmental impacts associated
with exposure to ADA contaminants, and presents potential remedial action criteria.
2.6.1 Human Health RIskS
A human health baseline risk assessment was conducted by the Anny to estimate the risk
posed to human health by the ADA shou:ld it remain in its current state with no
remediation. The risk assessment consisted of an exposure assessment, toxicity
assessment, and human health risk characterization. The exposure assessment detailed the
19
-------
Table 3: Summary of Contaminants of Concern in Ground Water at the ADA
I
I
Site
8 and 31
, 13 and 5711
14 and 38
15 and 55
16
Contaminant
01 Concern
Antimony
Arsenic
Barium
Copper
Vanadium
Zinc
RDX
Benzene
N itritelnitrate
Antimony
Arsenic
Barium
Selenium
Vanadium
Antimonv
Arsenic
Barium
Chromium
Selenium
Vanadium
. .
Antimonv
Arsenic
Barium
ManQanese
Zinc
-",....;',..... ..
Arsenic
Barium
Chromium
Selenium
Vanadium
Background
Concentration
ugll (8)
1
1
59
1
NSA
40
NSA
NSA
54000
. ...
...' ..... ...
.. ... H'...
...." ......-."""
'..,"..,',",',,',',',',",'.','.
. .. .......... .".........'"
...
"'"':';':':',':-:':':.
....
.. .
.. ....
'.'-
...... ~;~:~:::::::~:::~::::::::}:::::::::}::::::::~::::::::{:~:;:: . ... };:}::::;"}}:f::;::";::<... ',',"
18 Arsenic 1
Barium 59
Manaanese 140
Vanadium NSA
95% UCL
Concentration'
uaII
2.75
27
82.8
4.78
96.2
389
0.76
0.417
18996
1
1
59
1
NSA
5.71
30.5
118
3.99
36.6
1
1
59
1
1
NSA
2.72
32.8
104
13.8
11.2
43.8
...
,,'
...... ...
1
1
59
140
40
3.13
17
104
238
71.2
.. ..
1
59
1
1
NSA
26.8
71.5
8.58
4
141
Frequency
01
Detection
30f 9
100f 10
80f 8
20110
80f 8
1019
1 01 10
1 01 10
80110
1 of 4
4014
40f4
1 of 4
40f4
....
..
1014
40f4
4014
4014
4014
4014
".',",'.'.'...'.",','.',",','"
. .
...... .........
1 of 2
2012
20f 2
2012
1 of 2
...... .,"" '"
. ....,:.;.'..'.
60f 6
60f 6
30f 6
60f 6
60f 6
...".......
'::::::::::::::::;::::::;::::.:::;';:::::::::::::::;:::::::::::"::::}:
".."'" .......,........,............. ...
40
147
369
19.1
20f 2
2 of 2
2 of 2
2012
.~
20
-------
Table 3: Summ~ry of Contaminants of Concern in Groundwater at the ADA (continued)
I
I
Site
19
57111
Background 95% UCL Frequency
Contaminant Concentration Concentration 01
of Concern uQII (a) uQII Detection
Antimonv 1 18.4 2017
Arsenic 1 18.2 70t7
Bervtlium NSA 0.5 1017
COODer 1 3.32 1017
lead 5 9.53 10t7
Nickel NSA 17.7 10f7
Selenium 1 29.8 20t7
Vanadium NSA 89.5 60t6
1.3- DNB NSA 0.484 1ot6
... ..,:.
Antimonv 1 2.34 10t7
Arsenic 1 26.5 7017
Barium 59 74.2 6ot6
Bervtlium NSA 0.5 1017
Chromium 1 6.09 1ot7
Cooger 1 6.36 20f7
lead 5 9.88 3ot7
Nickel NSA 17.7 10f7
Vanadium NSA 63 6ot6
Zinc 40 30 2017
41
. .
,:"-;,:,,,.:.:::,.,:.;..:,...;:.:",.,",
... ...d... ..... .....d
. .,..............,-,..
.. .. .. ." .... ..........-...........
.. . . .........'
:'::::.:::::-::::~::::::::::::::::::;::~::::::::::::::::::::;::::;::;:::;:: ;:;:::::;:;;;:;:::;:;}:::;:::::;:;:;:;:;=;;::;:::::;:::::;:::::.:;::::
571
Antimonv
Arsenic
Barium
Chromium
Cooger
Manaanese
Vanadium
Zinc
1
1
59
1
1
140
NSA
40
5.07
30.8
104
13.2
8.78
189
37.1
40.7
20f4
40f4
4ot4
20f4
10f4
4ot4
2ot4
1ot4
30f 6
6ot6
60t6
10f6
6ot6
...::.:.::;~::::::::::::::::::::::::::::::::::::{.:~:~:~::~~:~:::ti:i{:::~:~:~:~:~:~:::~:;:;:~~::t~:~:~::,::~:;:::{::~::::::;~:~;;:~:~:::~:::~:~:~~::;:~:::;:::}~:::~:;:::;:~{{:~:~:~:;:~:~:~:~;~:~:~:t~:~:::::~:::~:~;~g~:~::~:~:~:;:~~::;:::~:::~:~:~:~:~:~:~:;:~{~:~:~:~:~:}f?~:::~:;:~:~:t~:::
...
, ., . . '. ...'
. .... . "... ........ .,....
.:.:.:.;.;.:.;......;...,;;':':':';"".,.-:.:.;.;.:.:.:.;.:,:.:.;.:::" '.'.'.'.'.'.'"
Notes:
UCl - Upper Confidence Umit
NSA . No Standard Available
(a) . Background concentration as established in RI
Ground water was not characterized at Sites 7, 17,21,32. 56, 58. and 60 because of the proximity of these sites to others where
ground water was characterized
Antimonv
Arsenic
Barium
MeraJrv
Vanadium
3.21
27.4
87.6
Q.449
56.8
1
1
59
0.4
NSA
59
None
21
-------
exposure pathways (such as dust inhalation) that exist at the ADA for various receptOrs.. -
The tOxicity assessment documented the adverse effects that can be caused in a receptOr
as a result of exposure to a contaminant.
The health risk evaluation used infonnarion on the amounts of contamination identified in
the remedial investigation, the toxicity of those contaminants. and possible human
exposure to the contaminants. Health risks are defined as those arising from a
contaminant's carcinogenic potential or its potential to cause health risks other than
cancer. The cancer risk level is the additional chance that an exposed individual will
develop cancer over the course of a lifetime. It is expressed as a probability such as
1 x lQ-6 (one in a million). Total noncarcinogenic health risks are expressed as a hazard
index (HI). In general. an HI of less than or equal to one indicates that ev~n the most
sensitive population is not likely to experience adverse health effects. If it is above one,
there might be a concern for adverse health effects. The degree of concern typically
correlates with the magnitude of the index if it is above one.
Risk assessments involve calculations based on a number of factOrs, some of whic}, o:ue
uncertain. First. the health effects criteria of specific chemicals are often bas&. on limited
laboratory studies on animal species that are then exuapolated to humans. Further, the
exposure scenario requires estimation of the duration and frequency of exposure, the
identity of the exposed individual, and the contaminant concentration at the point of
exposure. If the value of the factor required for the risk assessment is uncertain, a
conservative estimate is used so that a health-based exposure level or concentration can be
calculated. For example, in order to calculate a reference dose for humans, tOxicity
assessments divide doses observed to cause health effects in animals by an uncertainty
factor to account for species differences and human population variability. In the case of
uncertainties associated with exposure scenarios, the most conservative plausible scenario
is selected. For example, in the ADA risk assessment. risk values for future use
exposures were initially calculated for a residential use scenario because it represented the
most conservative future use scenario.
Primary databases and models (and their sources) used in the risk assessment to develop
toxicity information and health effects assumptions and criteria include:
.
Integrated Risk Infonnation System (IRIS) - EPA, 1991
Health Effects Assessment Summary Tables (BEAST) - EPA, 1991
Standard Default Exposure FactOrs - EPA, 1991
Uptake/Biokinetic (UBK) Model for Lead - EPA, 1991
.
.
.
The use of these databases and models is described in detail in the Human Health
Baseline Risk Assessment.
Risks of Contaminants of Concern In Soli
Contaminants of concern at the ADA include those contaminants that were found in soil
in concentrations above the background concenuation detennined for that contaminanL
Based on this criterion, the following were identified as contaminants of concern at ADA
sites:
..
22
-------
. Alwninmn . Zinc
. Antimony . Cyanide
. Arsenic . Nittatelnitrite
. Barium . Trichloroethylene
. Beryllium . Xylenes
. Cadmiwn . 1,3,5-TNB
. Chromium . 2,4,6-TNT
. Cobalt . 2,4-DNT
. Copper . 2,6-DNT
. Iron . RDX
. Lead . Tetryl
. Manganese . HMX
. Mercmy . Nitrobenzene
. Nickel . DDD
. Potassium . DDE
. Selenium . DDT
Silver . Dieldrin
. Thallium . Endrin
The populations at risk of exposure to the contaminants of concern at the ADA were .
identified by considering both cwrent and future use scenarios. Public access to the ADA
is cwrently restricted, and there is little incentive or opponunity for trespassers to
approach the contaminated ADA sites, so public exposure is unlikely. Currently, only
installation personnel conducting operations are being exposed to the contaminated ADA
sites. Current contaminant exposure routes are correspondingly limited to the inhalation
of contaminated soil as airborne dust by these installation personnel (incidental ingestion
of contaminated soil is also considered for Site 60 only). .
The probabilitY of future human exposures may be high, since reuse of the ADA may be
possible. The most likely routes of exposure to contaminants in soil are dermal
absorption of chemicals in soil, incidental ingestion of soil, and dust inhalation.
Soil concentrations used in the calculation of risks were Reasonable Maximum Exposure
(RME) concentrations. These concentrations are assumed to be the 95 percent upper
confidence limit (UCL) on the arithmetic mean of sampling data (values presented in
Table 2) unless the VCL is above the maximum detected value in which case the
maximum detected value is used. Using these concentrations and exposure factors
obtained from EPA's Risk Assessment Guidance for Superfund, chronic daily intake
factors for each chemical within each exposure pathway for a given population at risk
were calculated.
Using the toxicity and health effects data available and the calculated chronic daily intake
factors, excess cancer risks and noncancer HIs were calculated for current and future use
scenarios with the assumption that remediation of soils takes place.
Results of the calculations for current land use scenarios are presented in Table 4. As
shown. of the current receptors. the highest risks and hazards apply to the open
detonation pit and open burning tray workers. whose multiple pathway risk is &..X 10-7
with a corresponding hazard index of less than one.
23
-------
Table 4:
Summary 01 Total Risks and Hazard Indices Related to Exposure-
to Soli for Current Land Use Scenarios .
Ex~osure Cancer Hazard
Receptor Pat way(s) Risk Index
Open detonation pit and
open burning tray workers Dust inhalation 8 x 10-7 <1
Target range users Dust inhalation and
Incidental soil ingestion 1 x 10-9 <1
Pesticide workers Dust inhalation 5 x 10-10 <1
24
-------
A summary of risks and hazards posed by exposures to contaminated soil associated with
th~ future use of the ADA is presented in Table 5. These risks and hazards were
calculated for each of the ADA sites where contamination was present in soil and
represent future residential use, the most conservative future use scenario. The exposure
pathways used to calculate the values presented in Table 5 are dermal absorption of
chemicals in soil (Pathway 1), incidental ingestion of soil (pathway 2), and dust
inhalation (Pathway 3).
As shown, if no soil remediation occurs, the excess cancer risks associated with direct
soil contaCt by future residents assuming a reasonable maximum exposure scenario are
greater than 1 x 1
-------
The potential risks associated with exposure to soil contamination by future residentS. -
exceed the acceptable carcinogenic risk range, non-carcinogenic hazard level, or action
level for lead at the following sites:
Table 5:
Summary of Risks and Hazard Indices Related to Exposure to Soli
for Future Residential Users
Site
Exposure
Pathways
Cancer
Risk
Hazard
Index
7
8
13
14
15
16
17
18
19
21
31
32, Area I
32, Area II
38
41
55
56
57, Area I
57, Area II
57, Area III
58
59
60
(a)
(b)
1,2,3
2,3
1,2,3
1,2,3
1,2,3
2,3
1,2,3
2,3
1,2,3
1,2,3
1,2,3
1,2,3
2,3
(b)
2,3
2,3
1,2,3
2,3
(a)
(a)
2,3
5 x 10-5 0.9
8 x 10-7 0.2
4 x 10-4 . 200
9 X 10-7 7
2 x 10-5 10
2 x 10-5 0.6
2 x 10-2 3000
(~) (d)
1 x 10-3 220
2 x 10-5 0.08
2 x 10:5 2
2 X 10-7 0.5
(c) 0.08
2 x 10-5 0.002
(c) 0.005
2 x 10-8 0.09
1 x 10-5 0.3
(c) 0.3
Notes:
(a) No contaminants of concern delecled
(b) Exposure pa1hways 1,2, or 3 were not calculated because no contaminants of concern were detected
in soils to a deplh of two feet. Therefore, no contaminants of concern presenled cancer or
noncancer risks for these pathways.
(c) Not calculaled because conwninant(s) are noncarcinogenic or potency factOrs are not available
(d) Calculated hazard index less than 1 x 1
-------
.
Site 15 (Cancer Risk = 4 x 1(}4, ill = 200. 95% UCL lead = 695 ppm)
Site 16 (HI = 7) .
Site 17 (HI = 10,95% VCL lead = 1.460 ppm)
Site 19 (Cancer Risk = 2 x 10-2, ill = 3000.95% UCL lead = 3.908 ppm)
Site 31 (Cancer Risk = 1 x 10-3. HI = 220)
Site 32 (Area II) (HI = 2. 95% VCL lead = 1.263 ppm)
.
.
The potential risks associated with exposure to soil contamination by future residents are
within or below the acceptable carcinogenic risk range. non-carcinogenic hazard level.
and action level for lead at sites 7. 8. 13. 14, 18.21.32 (Area I). 38.41.55.56.57,58,
69. and 60.
As stated above. the future residential scenario represents the most conservative of the
possible future use scenarios. However. future residential use of the ADA is highly
unlikely due to the presence of UXO in unknown quantities at unknown depths and
locations throughout the ADA. Future industrial use is a far more realistic (and still
conservative) future use scenario for the ADA. For this reason. cancer risk and
noncancer hazard calculations were perfonned assuming a furore use of light indusaial
for the sites that exceeded the acceptable residential cancer risk ranges and/or noncancer
hazard levels (Sites 15, 16. 17,19.31.32 [Area 11). The results ofthese calculations
are presented in Table 6.
The risks and hazard indices presented in Table 6 indicate that. based on these values,
Sites 16, 17. and 32 (Area ll) are within or below the acceptable cancer risk range or
noncancer level for future light industrial users. However. it should be noted that soils at
Sites 17 and 32 (Area II) still exceed the 500 ppm action level for lead.
In summary, in the event of likely future land use changes at the ADA brought about by
UMDA's inclusion in the BRAC program. actual or threatened releases of hazardous
chemical substances in soil from the site, if not addressed by implementing the response
action selected in this ROD. may present a threat to human health associated with future
light industrial use at the following sites:
. Site 15
. Site 17
. Site 19
. Site 31
. Site 32 (Area II)
Based on the discussion provided above, if no response action is implemented at the
following sites. unacceptable human exposures to hazardous chemical substances in soil
will not occur for future light industrial workers:
. Site 7 .. Site 21 . Site 57
. Site 8 . Site 32 (Area I) . Site 58
. Site 13 . Site 38 . Site 59
. Site 14 . Site 41 . Site 60
. Site 16 . Site 55
In addition to the health risks caused by the chemical contaminants in soil. risks are posed
by UXOs. UXOs present a human safety hazard if they are encountered and detonate
27
-------
Table 6:
Summary of Risks and Hazard Indices Related to Exposure -
to 5011 for Future Light Industrial Users .
Exposure Cancer Hazard
Site Pathways Risk Index
15 1,2,3 7 x 104 80
16 1,2,3 6 x 10-7 1
17 1,2,3 3 x 10-6 0.9
19 1,2,3 2 x 10-3 400
31 1,2,3 5 x 104 102
32, Area II 1,2,3 8 x 10-6 1
Exposure Pathways
1 - Dennal absorption of chemicals in soil
2 - Incidental ingestion of soil
3 - Dust inhalation
28
-------
accidentally. Accidental detonation could also result in the spread of explosive
contamination in the environment
Risks 01 Contaminants 01 Concern In Ground Water
As stated in Section 2.5.2, for the most pan, contaminants of concern in ground water
are those that were identified in background ground water characterizations. These
contaminants were consistently identified across the entire installation and were not
resnicted to the ADA. The most ubiquitous contaminant of concern in the ground water
at the ADA is arsenic, which was detected in levels above the value established in the RI
as background (1J..lg/l) at all sites at which ground water was characterized (with the
exception of Site 59).
A summary of risks and hazards posed by exposures to ground water associated with the
future use of the ADA is presented in Table 7. These risks and hazards represent funue
residential use, the most conservative future use scenario. The exposure pathways used
(0 calculate the values presented in Table 7 include one or more of the following:
Ingestion of Ground Water (Pathway 5)
Inhalation of Volatile Contaminants Emitted from Ground Water During
Showering (Pathway 6) .
Dermal Absorption of Ground Water During Showering (Pathway 7)
As shown in Table 7, ground water-related risks and hazards exceed the futlD"e residential
use criteria (risk of 1 x 10-6 and HI of 1) at Sites 8, 13, 14, 15, 16, 18, 19,31,38,41,
55,571,5711, and 57nI. There are two important points to note about this observation:
First, all of the exceedences in risk-based values are due to the presence of arsenic
in the ground water. However, it is likely that the levels of arsenic measured in
ground water at the ADA represent background levels because: the values
consistently fall in a range of 10 to 40 J.Lgll across the ADA (see Table 3); there is
no apparent correlation between arsenic levels in ground water and arsenic levels
in contaminated soil at the ADA; and, the vaiue established in the RI as
background was based on much more limited sampling. Moreover, in no case
does arsenic exceed the regulatory maximum contaminant level (MCL) for arsenic
of 50 J.Lg/l.
.
Second, residential use represents the most conservative of the future use
scenarios and a future use of residential for the ADA is extremely unlikely due to
the presence of UXO. To evaluate the degree of conservatism represented by a
future residential use over the more likely future industrial use for the ADA, the
RA included a calculation of carcinogenic risks and noncarcinogenic hazards for
both future use scenarios at Site 31. 111= results of these calculations showed that
the risks and hazards for residential users are three times greater than those for
industrial users. As with the future residential use scenario, the risks and hazards
of exposure to ground water for future industrial users at Site 31 were due to the
presence of arsenic.
Based on the discussion above as well as the results of the RI with respect to ground
water characterization as presented in Table 3, no remedial action is required for the
cleanup of ground water at the ADA.
29
-------
Table 7:
Summary of Risks and Hazard Indices Related to Ground Water.
Exposure for Future Residential Users.
Exposure Cancer Hazard
Site Pathways Risk Index
7 None
8 5,6,7 6x104 3
13 5 6 x 104 3
14 5 7x104 4
15 5 3 x 104 2
16 5 6x104 3
17 None
18 5 8 x 104 4
19 5 4 x 104 4
21 None
31 5,6,7 6 x 104 3
32, Area I None
32, Area II None
38 5 . 7 x 104 4
41 5 6 x 104 3
55 5 3 x 104 2
56 None
57, Area I 5 6 X 104 3
57, Area II 5 6 x 104 3
57, Area III 5 6 X lQ4 3
58 None
59 None
60 None
Notes: Ground water was not characterized at Sites 7.17.21.32.56.58.59 or 60 because of the
proximity of these sites to others where grouno water was characterized.
Exposure Pa1hways
5 - Ingestion of Ground Water
6 - InhaJation of Volatile ContaminantS Emiaed From Ground Water During Showering
7- Dermal Absorption of Ground Water contaminantS During Showering .
30
-------
2.6.2 Environmental Evaluation
As part of the Remedial Investigation, an Ecological Assessment (EA) was performed for.
UMDA. This EA involved a process to evaluate the current and potential effect to site
biota from contaminants in soil at UMDA. In this process, the toxicity and environmental
fate of contaminants of concern were evaluated on an installation-wide basis for
contaminants found at or near the surface. Thiny contaminants of concern were
identified at locations at which wildlife might be exposed. These 30 conwninants include
metals, explosives and their derivatives, and pesticides. Of these, the most significant in
terms of volume, disttibution, and relative toxicity, are lead. zinc. aluminu~ 2.4.6-
TNT. HMX. RDX, and tetryl. These contaminants are found in soils at the ADA.
The chronic toxicities imposed by the contaminants of concern were developed by
calculating the ratio of estimated daily contaminant uptake rates to No Observed Adverse
Effect Levels (NOAELs) for four indicator species: field mouse. pronghorn antelope.
American badger, and S wainson . s hawk. Daily contaminant uptake rates are a function of
contaminant concentration and exposure pathways. Exposure pathways considered in
this assessment include direct or indirect ingestion of soil by the indicator species. The
ratio of contaminant uptake rates to NOAELs is represented by a hazard quotient (HQ) for
each of the contaminants of concern. .
Currently one indicator species. the pronghorn antelope, is excluded from the ADA by a
fence. In the event that fence removal occurs in the future. the pronghorn would likely
still have no exposure to contaminants in the ADA because it is expected that they will be
confined in a new fenced wildlife area at UMDA, moved to another reservation. or .
harvested.
A summary of the risk characterization performed for the principal contaminants of
concern at the ADA is presented in Table 8. As can be seen. contaminants at Sites 15.
19. and 31 present the greatest concern in terms of magnitude of worst-case HQ. In
order to determine the variability in individual site HQs, median values of HQ were
determined for selected site/contaminant/species combinations as shown. Note that these
median values are significantly less than the worst-case values (in fact, often these values
were 0 or close to 0) indicating that the worst-case values are not representative of the
ADA as a whole.
In surmnary, sites that represent potentially unacceptable levels of risks to indicator
species are also the sites that represent a threat to human health. The implementation of a
response action at those sites to the degree necessary to reduce the threat to human health
will also reduce the threat to the environmenL
2.6.3 Remedial Action Criteria
Neither state nor federal regulations contain chemical-specific soil-cleanup standards for
the contaminants of concern. However. both authorities provide a framework for
developing risk-based remedial action criteria. The State of Oregon requires cleanup to
background or, if that is not feasible, the lowest levels that are protective of human health
and the environment and feasible. The NCP provides guidelines in terms of acceptable
carcinogenic and non-carcinogenic risk.
Potential risk-based remedial action criteria (RAC) were calculated based on direCt contact
with ADA soils. RAC for the contaminants of concern present at the sites to be subjected
to remedial action are presented in Table 9. These RAC represent soil concentrations for
future residential and industrial uses equivalent to excess cancer risks of 1 x 1 Q-6 and
31
-------
Table 8: Environmental Risk Characterization Summary
Co)
N
"'~I:.!!:illlril~::ij~::::::: - 1I1!~1 ,: Worst.Clse . ... ." .. h,>"
. . ."',
., .....,
. ," ,"-',",' "",'
....,",. ...,. '~~di~n'
'i'thror1lc ,', "':,
@iJ/SDteie../II .\:..Q (Site) \"Q""'" :.: : Comments
Field Mouse Home range for mice is typically smaller than the area 0' an individual site.
Lead 0.032 397 (19) 16.2 Lead is the most ubiquitous contaminant of concern at the ADA
Zinc 9.6 98.5 (19)
Barium 1.2 95.8 (19)
Antimony 0.35 43.4(15)
Cobalt 0.057 18.8(15) HO calculated from background soil ccncentrations suggest a slight
health risk from exposure; probable explanation is the inadequacy 0' the database.
Cadmium 1.1 9.09(15) 0 Potential neurotoxic and nephrotoxic effects minimal compared to effects 0' lead
RDX 1.5 497(15) 0 Acute HO supports conclusions for chronic HO
TNT 10 178(31) 0 Acute HQ supports conclusions for chronic HO
TNB 0.11 76.9(31) Absence of database makes toxicltv criteria almost meaninaless
Pronahorn Pronahorns are Drevented from enterlna the ADA due to a hiah restrainina fence.
Ba;Jger Home range for badgers Is approximately twice the size of the ADA.
Rodents were used as surrogate animals to calculate HO 'or Cu, Sb, and Co.
Copper 0.33 209.0(19) 0.3 Surrogate species may have been unusually sensitive to Cu.
Barium 0.19 85.8(19) 0
Antimony 0.056 38.9(15)
Lead 0.067 I 36.9(19)
Zinc 7.4 18.1 (19)
Cobalt 0.0091 16.6(15)
TNT 0.021 195.0(31) 0
Hawk Contaminated sites are only about 2 % of the migratory hawk's home range and
the sites are probably not preferred hunting grounds for the hawk.
Lead 0.043 179(19) 4.45
Cadmium 0.049 131(15) 0
Chromium 0.49 28.6(15) .
Note:
(a) No Adverse Effect Levels - Standardized reference levels that theoretically represent the highest exposure concentration not associated with
-------
Table 9: Risk-Based Remedial Action Criteria
.. Risk-Based Remedial Action Criteria
Contaminant . ~1de~~.. Ught Induatrlal Ught Indust~!)
ot CRLs(a) Background(b}' 'Rlsk~(c)' Risk-based (d) '. Rlsk-bas8d (8);:'\
.. '=m' ppm
Concem ppm ppm ppm'," ..
Antimony 3.8 3.8 110 818 818
Arsenic 0.25 5.24 0.363 0.898 ' 8.98
Barium 29.6 233 13700 861 861
Bervllium 1.86 1.86 0.148 0.809 8.09
Cadmium 3.05 3.05 127 2.75 27.5
Chromium 12.7 32.7 19 0.413 3.71
Cobalt 15 15 2.74 20.~ 20.2
Lead 6.26 8.37 CO (fl (0
Mercury 0.05 0.056 81.9 292 292
Nickel 12.6 12.6 470 10.2 102
Selenium 0.25 0.25 1370 10200 10200
Silver 0.025 0.038 1370 10200 10200
Thallium 31.3 31.3 21.9 164 164
Zinc 30.2 94 54800 409000 409000
Nitrate/nitrite 0.6 9.9 438000 NA NA
Trichloroethvlene 0.003 NSA 58 441 4410
Xylenes 0.002 NSA 354000 382000 382000
135 TNB 0.488 NSA 1.05 2.27 2.27
246 TNT 0.456 NSA 1.64 4.24 22.7
24 DNT 0.424 NSA 0.0723 0.187 1.87
26 DNT 0.085 NSA 0.0723 0.187 1.87
HMX 0.666 NSA 1050 2270 2270
RDX 0.587 NSA 5.81 52 520
Nitrobenzene 2.41 NSA 10.5 22.6 22.6
Tetryl 0.731 NSA 211 454 4S4
DDD 0.008 NSA 2.66 23.8 238
DDE 0.008 NSA 1.88 16.8 168
DDT 0.007 NSA 1.88 12.7 127
Dieldrin 0.006 NSA 0.0399 0.269 2.69
Endrin 0.007 NSA 82.1 613 613
Notes:
NA - Not applicable
NSA - No standard available
(a) Certified Reporting Umit used in RI
(b) Background Concentration established in RI
(c) Based on a Residential cancer risk of 1 E-06 or an HQ of 1
(d) Based on a light Industrial cancer risk of 1 E-06 or an HO of 1
(e) Based on a Light Industrial cancer risk of 1 E-QS or an HO 01 1
(f) Cleanup level for lead established at 500 ppm
33
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1 x 10-5, andlor noncancer risks with IDs of one. For reference and comparison,
~ckground concentrations and cenified reponing limits for each of the conwninantS of
concern are also provided.
From the RAC presented in Table 9, cleanup levels were selected. These levels are based
on the possible future light industrial use of the ADA with the objective of reducing
excess cancer risks to within a range of 1 x 104 to 1 x 10-6 or noncancer risks to one or
less (or meeting the action level of 500 ppm for lead). Where these values were at. or
very close to, background concentrations or analytical deteCtion limits, they were
increased to represent technically feasible criteria while maintaining adequate
protectiveness for possible fuwre users of the ADA. At Sites 15, 17, 19, 31, and 32
(Area ll), the following contaminants are present at concentrations exceeding cleanup
levels:
. Antimony
. Arsenic
. Barium
. Beryllium
. Cadmium
. Chromium
. Cobalt
. Lead
. Thallium
RDX
. 1,3,5-TNB
. 2,4,6-TNT
. 2,4-DNT
The corresponding cleanup levels are presented in Table 10. For reference, this table also
shows background and maximum 95 percent UCL concentrations of the contaminants at
each of the sites.
The RAC for the ADA also include the removal of UXO to permit safe use of the ADA.
Under the current use of the ADA, only a surface clearance of UXO as well as that
necessary to safely conduct a cleanup of contaminated soil will be required. However,
additional clearance of buried UXO may be required consistent with a future use decided
for the ADA (~ee Section 2.7.7).
2..7
Description of Alternatives
A range of general response actions was considered for remediating the ADA soils. The
actions were first screened for general applicability, then several that appeared to be
appropriate for the site were evaluated for effectiveness, implementability, and, to a lesser
extent. cost. The actions initially evaluated included:
.
No action
Institutional controls (access restrictions, land use restrictions)
Containment (engineered cap, soil cover, vegetative cover, surface controls)
On-site disposal
In situ treatment (biological, physical-chemical, thermal)
Ex situ treatment (biological, physical-chemical, thermal, off-site treattnentldisposal)
UXO clearance (from the surface and to 1-,5-, and 20-foot depths)
.
.
.
.
.
.
From this evaluation, five remedial alternatives were assembled that contained one or
more elements from the responses listed above. These include:
34
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Table 10: Cleanup Levels for Contaminants at the ADA
r ". Cleanup Background Concentration in Soil (a)
Level Level (ppm)
Contaminant (DPm) (DDm) Site 15 Site 1 7 Site 19 Site 31 Site 32.11
,",',",',',',',',','''.',',',',',',",'.',',", ::::;~::::;:::;~':::::::31.28
....................,....
Antimonv 820 3.8 ¥r?{lir~ 85 NA 30.6
Arsenic 1 5 5.24 ::"::,i::i:::~~i:i::m:mf20 BB '::;:~i::;:::i.;::::;:~i::::244 BB BS
Barium 860 233 ::::::::iMj~::;f.;;~;;i. BB :;;:jji;:I:j::::I2567.8 31 5 ~~~~~OODl~
Bervllium 8. 1 1 .86 :!:,!1j::::iliMii?Jii 3 NA NA NA
Cadmium 28 3.05 :i.~*jM;f~~i935J 5.25 ~i*1i~~~i~i.i~ NA NA
Chromium 40 32.7 :.@[*~ftfi!&O NA Imji:~Mt~. SS NA
Cobalt 25 1 5 iiM::::i;:iffi[jiiI1r2i9 23.7 NA NA NA
",",',',',','.-.','.',',',','."'.....'.....'.'.',', ~;;::i::i:ijj~j::::~:D60 ;t~~~j*:mi:;;39D8 jil~f~f:~{lfaE
Lead 500 8.37 :t:f@lltIiS SS
Thalliu m 1 60 31 .3 :.,:::::::::~:iit~m:. NA NA NA NA
........ .......
......,.................
RDX 52 NSA :::jl:;f:j@::~:.'26 1 .32 3.5 3.08 ~
1 35-TNB 2.3 NSA 1 .42 NA :;:jjjji:jiil;@i;1. l*t~1r~1~f~ji1j}ji: NA
246- TNT 23 NSA :":m:Mi:~:j~;tfjD 3.01 ::ifillffili8Mi :::m:jj:::1:lt!ii. NA
24- DNT 1 .9 NSA NA NA 1 .39 :i:ffi;~i:i:i:i::t{. 1 .61
Notes:
(a)-95% UCL Concentration (shading indicates that concentration is above the cleanup level)
NA-Not Analyzed
BB-Below Background
NSA-No Standard Available
ppm-Parts per million
35
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Alternative 1:
No action
Alternative 3:
Containment of contaminated soil by soil cover
On-site treatment of all contaminated soil by solidification/stabilization
and on-site disposal .
Alternative 2:
Alternative 5:
On-site treatment of all contaminated soil by both incineration and
solidification/stabilization and on-site disposal
Off-site treatment of hazardous contaminated soil and off-site disposal
Alternative 4:
In addition to these alternatives for the cleanup of contaminated soil at the ADA,
approaches to quantify and reduce the safety risks due to UXO were examined. These
approaches included the detection of UXO and their removal from the ground smface and
to depths of 1 foot, 5 feet, and 20 feet This UXO removal would be perfonned in
conjunction with anyone of the cleanup alternatives with the exception of Alternative 1,
~o Action. A discussion of UXO clearance is provided at the end of this section.
Alternatives 3 and 4 involve the disposal of treated soils and residues in the on-site
UMDA landfill. This landfill is located in the eastern portion ofUMDA. Under an
agreement entered into by the Army and ODEQ, this landfill will cease receipt of
municipal waste in mid-1994, but may receive treated soils until late March 1998. The
Army is currently in the process of preparing a closure plan for the landfill in accordance
with its pennit and ODEQ solid waste regulations and guidance.
An additional common element to the alternatives evaluated (with the exception of the No
Action alternative) is the requirement for institutional.controls at the ADA. Since the
requirements for institutional controls are closely tied to UXO clearance, they are also
discussed at the end of this section.
2. 7.1 Alternative 1: No Action
Evaluation of the No Action alternative is required under CERCLA, serving as a common
reference point against which other alternatives can be evaluated.
In Alternative I, no containment, removal, or treatment of the soil at the ADA would
occur, and no new controls would be implemented to prevent human exposure.
However, existing security provisions that limit public access will continue until such
time as the Army vacates the UMDA facility. Natural recovery of the contaminated soil is
unlikely at the ADA due to the characteristics of the dominant contaminants. The
contaminants are nonvolatile and therefore their volatilization from soil at ambient
temperatures is unlikely. In addition, due to the low organic content of the ADA soils as
well as the relative resistance of the contaminants to biodegradation, degradation of the
contaminants is unlikely. The primary mechanism that may serve to reduce contaminant
concentrations is their dispersion (and resulting dilution) by wind. This mechanism is
applicable to surface soils only.
The primary route of migration of contaminants in soil at the ADA is through wjndblown
dust A course of No Action would do nothing to limit the potential for contaminant
migration.
36
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.-
This alternative does not meet the Oregon requirement for cleanup to background. or the-
lowest levels that are protective and feasible. nor does it achieve proteCtion of human
health and the environment within the guidelines of the NCP. The human health risks
presented in Table 6 are not reduced.
UXO would remain present at the ADA and would continue to present safety and
environmental risks due to the potential for accidental detOnation and exposure.
Alternative I requires no time to implement and involves no capital or O&M costs.
2.7.2 Alternative 2: Containment of Contaminated Soli by Soli Cover
Alternative 2 involves placing a layer of clean soil over areas of contaminated soil to
minimize potential contaCt with and exposures to contaminated soil while preventing the
spread of contamination as dUSL The primary actions involved in implementing this
alternative include:
.
Clear UXO at the contaminated sites to the degree necessary to safely perfonn soil
containment action (assumes a UXO clearance to a maximum of 5 feet in depth).
Place soil cover over the contaminated areas. The soil cover consists of an 18-inch
layer of clean soil obtained from uncontaminated areas at UMDA.
Plant vegetation on clean soil cover to restOre area and prevent erosion.
.
.
Estimates of the cost of implementing this alternative were developed based on an
estimate of contaminated soil surface area to be covered of 125.000 square feeL The
present wonh of the alternative assumes completion of the action within 15 months. The
estimated costs of implementing Alternative 2 are:
.
Capital Costs: $290.000
O&M Costs: $10,000
Present Worth: $300,000
The following major ARAR is cited for Alternative 2:
.
Alternative 2 may not comply with state requirements for cleanup. Contaminant.
concentration levels are not reduced in Alternative 2. The state of Oregon considers
the use of caps or covers as measures to supplement cleanups. They may be used as
substitutes for cleanup only if it is determined that no other cleanup methods are
protective and feasible.
Alternative 3: On-Site Treatment of All Contaminated Soli by
Solidification/Stabilization and On-Site Disposal
In this alternative, excavated contaminated soil would be treated by .
solidification/Stabilization. Treated materials would be placed in the on-site UMDA
landfill Primary actions involved in implementing this alternative include:
2.7.3
.
Qear UXO at the contaminated sites to allow for safe access to, and excavation of,
contaminated soil.
Excavate contaminated soil.
Conduct treatability studies of the use of solidification/stabilization.
Treat contaminated soil by solidification/stabilization.
Coniinn. by testing and analysis. that treannent residuals are nonhazardous.
Dispose of the treatment residuals in the on-site UMDA landfill.
.
.
.
.
.
37
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Solidification/stabilization waste treattnent processes involve the mixing of specialized -
aqditives or reagents with waste materials to reduce (physically or chemically) the -
solubility or mobility of contaminants in the mattix. A common
solidification/stabilization process involves mixing the wastes with a mixture of a
pozzolan such as fly ash and cement to produce a relatively high-strength waste/concrete
mattix in which contaminants are napped.
Solidification/stabilization is a commonly used and effective technology to treat soils and
sludges contaminated with metals so that th,e contaminants no longer present any threat to
human health or the environmenL There is evidence that the technology will also
eliminate the potential threat resulting from organic compounds such as explosives and
pesticides. Treatability studies are perfonned to develop the proper mix of chemical
additives and operating conditions to achieve the desired results. -
The process to be used at the ADA would employ a mobile system brought on site. These
systems typically come complete with chemical storage units. chemical feed equipment,
mixing equipment (usually a pug mill), and waste and product handling equipmenL
Implementation of the process would require sufficient land area around the operation to
maintain a buffer zone, access roads capable of supporting heavy equipment (in this case,
80,OOO-lb trailers), and direct and unencumbered accessibility to the waste feed material. -
As the contaminated soil is treated, it is discharged to a dump truck, roll-off boxes, or
other transportable containers for transpon to the disposal area.
A representative solidification/stabilization system has a nominal throughput of 350
tons/day (including material to be treated and reagents).
Estimates of the cost of implementing this alternative were developed based on an
estimate of contaminated soil volume of 14,000 cy. The present worth of the alternative
assumes completion within 15 months. The estimated costs of implementing Alternative 3
are:
.
Capital Costs: $1,100,000
O&M Costs: $1,300,000
Present Worth: $2,400,000
.
.
The following major ARARs are cited for this alternative:
.
This alternative complies with the state of Oregon cleanup requirements. Although
cleanup to background is not achieved. the feasibility of cleanup to background was
evaluated and considered not cost effective. This alternative provides for the
required level of risk reduction to meet industtial future use standards at the ADA.
This alternative complies with RCRA requirements regarding the identification and
listing of hazardous waste (40 CPR 261.3); standards applicable to generators of
hazardous wastes (40 CFR 262); land disposal resttictions (40 CFR 268); design
and operating standards for treannent units (40 CFR 264); and closure requirements
for interim status units (40 CFR 265 Subpart G).
.
38
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.
This alternative complies with state of Oregon Air Pollution Control Regulations that
. require control of emission involved in the excavation and handling of contaminated.
soil.
2.7.4 Alternative 4: On-Site Treatment of All Contaminated Soli by Both
Incineration and Solidification/Stabilization and On-Site Disposal
This alternative is similar to Alternative 3, except that soils contaminated with organic
compounds are treated in a mobile incinerator brought on site rather than by solidificationl
stabilization. This would result in the desnuction of the organic contaminants. The ash
resulting from the incineration of these soils would contain most of the metals contained
in the incinenued soils. This ash would be combined with the soils containing metals
only and treated by solidification/stabilization as described in Alternative 3. The treated
soils (and ashes) would be disposed of on site in the UMDA landfill.
Primary actions involved in implementing this alternative include:
.
Clear UXO at the contaminated sites to allow for safe access to, and excavation of,
contaminated soil.
Excavate contaminated soil.
Mobilize incinerator on site.
Conduct trial bums.
Incinerate organic-contaminated soil.
Conduct treatability studies of the use of solidification/stabilization.
Treat con~nated soil and incinerator residues by solidification/stabilization.
Confum, by testing and analysis, that treatment residuals are nonhazardous.
Dispose of the treaanent residuals in the on-site UMDA landfIll.
.
.
.
.
.
.
.
.
Rotary kiln incineration has been proven in similar remediations to reduce concentrations
of explosives in soil to below deteCtion limits. As a contaminant destrUction technology
for organics, it is protective of human health. Metal contaminants are not destroyed but
are contained in fly ash or the treated soil (ash). Solidification/stabilization would be used
to treat the metal-containing incineration residues as well as to treat those soils that
contain metals contaminants only.
Mobile, or tranSportable, incineration systems are available in a range of sizes with
varying feed rates. In this analysis, it is assumed that a rotary kiln incinerator designed to
process 4 tons of material per hour will be used. A treatment area would be developed in
close proximity to the ADA, with concrete and asphalt pads for the incinerator and feed
staging operations. A trial bum would be conducted to verify the destrUction and
removal efficiency for the organic compounds and demonstrate perfonnance of the air
emission controls.
Estimates of the cost of implementing this alternative were developed based on an
estimate of contaminated soil volume of 14,000 cy. The present worth of the alternative
assumes completion of the action within 20 months. The estimated costs of
implementing Alternative 4 are:
.
Capital Costs: $3.400,000
O&M Costs: $4,100,000
Present Worth: $6,900,000
.
.
The following major ARARs are cited for this alternative:
39
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.
.- This alternative complies with the state of Oregon cleanup requirements. Although
cleanup to background is not achieved. the feasibility of cleanup to background was
- evaluated and considered not cost effective. This alternative provides for the required
level of risk reduction to meet indusnial future use standards at the ADA.
.
This alternative complies with RCRA requirements regarding the identification and
. listing of hazardous waste (40 CFR 261.3); standards applicable to generators of
hazardous wastes (40 CFR 262); land disposal resnictions (40 CFR 268); design
and operating standards for treaUDent units (40 CPR 264); operating requirements
and performance standards for hazardous waste incinerators (40 CFR 264, Subpan
0); and closure requirements for interim status units (40 CFR 265 Subpart G).
This alternative complies with state of Oregon Air Pollution Conti'ol Regulations that
require conttOl of emission involved in the excavation, handling, and incineration of
contaminated soil.
.
2.75 Alternative 5: Off-Site Treatment of Hazardous Contaminated SoU and
Off-Site Disposal
This alternative involves the excavation and removal of all contaminated soil. As the soil
is excavated. it will be analyzed to detennine whether its contamination levels are high
enough to be considered hazardous according to the RCRA. These soils will be
traDsponed off site to a permitted treatment facility to be treated by solidification!
stabilization. Treated soils will then be disposed of in an off-site landfill. Contaminated
soils thiu do not require tteatment according to RCRA will be disposed of off site.
Primary actions involved in implementing this alternative include:
.
Clear UXO at the contaminated sites to allow for safe access to, and excavation of,
contaminated soil.
Excavate contaminated soil. -
Analyze excavated soil to determine its hazardous characteristics in accordance with
RCRA.
Segregate hazardous and nonhazardous contaminated soil.
Prepare manifests for the transpon of the hazardous contaminated soil.
Transpon hazardous and nonhazardous soil to a RCRA-permitted facility for the
treaanent of hazardous soil.
Dispose of treated soil and nonhazardous soil in an off-site landfill.
.
.
.
.
.
In this alternative, existing data and additional confmnation sampling and analysis will be
used to detennine the hazardous characteristics of the soil (with respect to the presence of
toxic concentrations of metals, explosives, or pesticides) and allow for segregation of the
RCRA hazardous and nonhazardous soil. To the maximum extent possible, segregation
will occur during excavation with necessary confmnation analyses performed after
excavation.
On-site requirements for the implementation of this alternative are minimal. Personnel
will be required to excavate the soil; conduct sampling and analysis of the soil samples;
prepare manifests as necessary; and load the excavated soil for transpon off site.
Estimates of the cost of implementing this alternative were developed based on an
estimate of contaminated soil volume of 14,000 cy. The present worth of the alternatives
40
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... .C?
f ," ',' ..:
. .
~ ".'
.-
assumes completion of the action within 12 months. The estimated costS of implementing
Alternative 5 are: .
.
Capital CostS: $3.200.000
O&M Costs: $0
Present Wonh: $3.200.000
.
.
The following major ARARs are cited for this alternative:
.
This alternative complies with the state of Oregon cleanup requirementS. Although
cleanup to backgJound is not achieved. the feasibility of cleanup to background was
evaluated and considered not cost effective. This alternative provides for the
required level of risk reduction to meet industrial future use standards at the ADA.
This alternative complies with RCRA requirementS for hazardous waste
identification and analysis (40 CFR 261.3); standards applicable to generators of
hazardous wastes (40 CFR 262); closure requirements for interim status unitS (40
CFR 265. Subpart G); requirementS applicable to tteaanent of hazardous ,..astes by
off-site facilities that meet RCRA Standards for Owners and Operators of Hazardous
Waste Treaunent. Storage. and Disposal Facilities (TSDF) (40 CFR 264); and land
disposal resaictions (LDR) (40 CFR 268). The applicability of LDR will be
determined by analyses to determine the hazardous characteristics of the soil with
respect to the presence of toxic or reactive concentrations of metals. explosives.
and/or pesticides. . .
.
.
This alternative complies with state of Oregon Air Pollution Control Regulations that
require control of emission involved in the excavation and handling of contaminated
soil.
2.7.6 Institutional Controls
Implementation of each of the above alternatives for the cleanup of contaminated soil
would require that institutional controls be placed upon the ADA because of the presence
of UXO. The cost and scope of these controls will depend on the amount of site wide.
UXO clearance performed after the soil cleanup. In the absence of any site wide UXO
clearance. maintaining controls equal to current Army security would be required. These .
controls include restricted access, fence maintenance. and security surveillance. The
present worth cost of permanently maintaining these existing controls is estimated at
$1.000.000.
2.7.7 UXO Clearance
For any future use of the ADA that is different from the CUI1"ent use. some degree of
UXO removal. or clearance. will be required. The level of clearance required will be
specifically dependent on the future use decided upon for the ADA. For this reason,
approaches based on different levels of clearance were evaluated. These approaches
include:
.
Removal of UXO from the ground surface (surface clearance)
Detection and clearance of UXO to a depth of 1 foot (subsurface clearance)
Detection and clearance of UXO to a depth of 5 feet (subsurface clearance}
Detection and clearance of UXO to a depth of 20 feet (subsurface clearance)
.
.
.
41
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At any level of UXO clearance operations, clearance of visible UXO from the ground -
surface is required. In typical surface clearance operations, a "sweep team" made up of
several personnel walk abreast along established grids. The team members count and
remove all metallic items. Explosive items encountered may be marked for later removal
by personnel trained in explosive ordnance disposal.
After a surface clearance has been completed, subsurface clearance to depths of up to 5
feet is initiated by a subsurface survey usually conducted with hand-held magnetometers
(metal detectors) passed over the smface to detect subsurface items. Metallic items
detected at depths of 12 inches or less are often identified by probing and may be
removed by hand during the survey. Items at greater depths are typically flagged. Once
the survey is complete, the flagged locations are revisited to remove the item by
excavation with shovels or, if necessary, a backhoe.
Clearance of UXO to a depth of 20 feet (essentially considered a complete clearance)
. would involve a combination of survey and excavation of the entire area to be cleared to
provide for both UX0 1etection and removal. Such an excavation would not be feasible
across the entir.:. ADA and the costs for extensive clearance to that degree would be
prohibitive at over $500,000 per acre or over $900 million for the entire ADA. Although.
a 20-foot clearance is technically feasible, it is impracticable and is not cost-effective. As
a result, this alternative was dropped from funher consideration.
The present worth costs of implementing each of the levels of UXO clearance retained in
the evaluation are estimated at:
.
Surface Oearance:
Subsurface Clearance (to 1 foot):
Subsurface Clearance (to 5 feet):
$1.212,000 (completed within 1 year)
$7.225.000 (completed within 1 year)
$13,700,000 (completed within 2 years)
.
Because of unknowns associated with the future use of the ADA as well as the full extent
of contamination of the ADA by UXO, a phased approach to UXO clearance was
assessed. Phase I of the clearance consists of the following:
.
A metallic object survey will be conducted over the entire ADA to obtain an
approximate idea of how much metallic debris would have to be removed to clear the
ADA of possible ordnance. The present worth cost of this action is estimated at
$1,800,000.
.
Concurrently with the survey, a "visual sweep" will be conducted over the entire
surface of the ADA to locate and remove objects identifiable as ordnance (surface
clearance). The present worth cost of this action is estimated at $1,212,000.
Phase II activities will be dependent on the future reuse selected for the ADA. As pan of
the base closure process, a screening procedure will be used by the Anny to develop
plans for reuse of Anny installations subject to base closure. As outlined in Interim
Guidance "Army Base Closure Screening Process" (dated February 8, 1994), the
screening procedure consists of the following steps:
1. All Army installations will be screened with other military departments, DaD
agencies and instrumentalities. and the Coast Guard. At the same time, installations
will be screened with other Federal deparanents and agencies-to determi~
42
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",.1 "
. ~. - ~ . ;~ ., '
.;....
for the property. All panies must respond within 30 days with requirements for - -
future use. .
2. The department or agency that demonstrates an initial interest in the closing propeny
must submit a finn proposal on the future use of that propeny. The requesting
depamnent or agency must agree to reimburse the Anny for the full fair market value
of the propeny and transfer funds within two years of the initial request for the
propeny .
3. If not claimed under Steps One and Two, the propeny will be offered through the
Deparunent of Housing and Urban Development for homeless assistance purposes.
. .
4. Local redevelopment authorities will be advised with respect to the availability of
remaining unclaimed property. The redevelopment authority will have one year in
which to express interest in writing for use of any buildings or propeny not claimed.
5 . Any remaining surplus propeny will be screened with state and local governments
for public purposes. A public agency will be required to advise of its need fo'; :he
propeny within 20 calendar days. The state will be allowed 60 days to cormnent.
: . .-"-
6. Any remaining propertY will be offered for sale to the general public on a
competitive basis.
.~
Upon completion of this screening process and the establishment of a future use for the
ADA (that is approved by DoD, the state of Oregon, and the local reuse conunittee),
additional clearance of UXO to a depth that is proteCtive for the final land use will be
conducted. This Phase II clearance will ~ initiated within 15 months after the final land
use decision has been reached.
~ ,vi
.,
Because the full extent of UXO present at the ADA is unknown now, UXO removal
costs could easily vary. Table 11 illustrates the relationship between the possible future
land uses and corresponding depths of UXO clearance, estimated costs of clearance, and
the degree of institutional controls needed.
When the Phase D clearance of UXO has been completed, appropriate institutional
controls will be applied to the ADA to permanently limit the use of, and access to, the-
ADA consistent with the final use selected for the area and the degree to which UXO are
cleared. The present wonh cost of permanently maintaining these controls is estimated at
$1,000,000.
.".~
2.8 Summary 01 Comparative Analysis 01 Alternatives
This section provides a summary of the relative petformance of each of the remedial
alternatives with respect to the nine CERCLA evaluation criteria.
2.8.1 Threshold Criteria
Overall protection of human health and the environment. Alternative 1, me No
Action alternative, is not protective of human health and the environment Alternative 2
will not result in the treatment or removal of any of the contaminated soil; however, this
43
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Tat)le 11: UXO Clearance Levels, Costs, and Access Controls Required
Degree of Estimated Present Access Controls
Land Use Clearance Wonh Cost of Clearance Required
Current Army Surface Oearancel $3.012.000 Deed Resttictions.
Use Survey (phase I) Security. Fencing
RecreationaV Surface to 1 foot $1.212.000 to $7.225.000 Deed Resttictions.
Wildlife Security. Fencing
Industrial 1 to 5 feet $7,225.000 to $13.700.000 Deed Resttictions.
Security. and/or
Fencing
Residential 5 .') 20 feet $13.700.000 to )900.000.000 Deed Resttictions.
Security. and/or
Fencing
44
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alternative will reduce the risks associated with potential contacts with the soil and spread
of contamination by dust
Alternatives 3 and 4 provide the best potential for effectively protecting human health and
the environment from soil contamination at the ADA. These alternatives result in the
removal of all contaminated soil followed by treatment to prevent fwther threats imposed
by the contaminants. Following tteaanent, the treated soils will be placed in the on-site
UMDA landfill that will be properly maintained and monitored to ensure that overall
proteetion is maintained. In these alternatives, all actions associated with the cleanup are
conducted on site and therefore preclude any risks associated with off-site traDspon of
contaminated or treated soils.
Alternative 5 involves the treatment of only those soils that are defined as hazardouS -
contaminants in the other soils would be left untreated. However, the disposal of both
treated soil and untreated nonhazardous soil in Alternative 5 would be to a properly
maintained and monitored landfill. This alternative involves the transpon of contaminated
soil off site, which present~ potential risks to human health and the environment outSide
the boundaries of U1IDA.
Removal of UXO consistent with the selected land use will provide for a reduction of
risks and hazards associated with their presence at the ADA. The continued use of
institutional controls will fwther provide long-term protection of human health and safety
with respect to UXO.
Compliance with ARARs. Alternative 1 does not comply with ARARs. Alternatives
3, 4, and 5 comply with all ARARs.
State soil cleanup requirements are met by Alternatives 3, 4, and 5 in that contaminants at
the ADA sites are reduced to the lowest levels that are protective and feasible. The state
of Oregon requirement to determine the feasibility of cleanup to background was
evaluated by estimating COSts to clean up all the ADA to standards based on residential
land use that most closely match background levels. The cleanup to residential land use
. standards at the ADA would cost approximately tWice as much as cleanup to industrial
use standards. Since both cleanups would achieve the required level of risk reduction to
meet industrial future use standards at the ADA, the additional cleanup cost to reach
residential (or background) standards is not cost-effective.
Contaminant concentrations are not reduced in Alternative 2. The state of Oregon
considers the use of caps or covers as measures to supplement cleanups. They may be
used as substitutes for cleanup only if it is dttermined that no other cleanup methods are
protective and feasible. As a result, Alternative 2 may not meet state requirements.
Alternatives 3, 4, and 5 will comply with applicable RCRA regulations and standards
including those establishing requirements for meeting treatment standards for hazardous
wastes, hazardous waste analysis and identification, hazardous waste incineration,
standards for generators of hazardous wastes, hazardous waste transpon and neattnent,
and closure of interim status units. .
Alternatives 3, 4, and 5 will comply with state and federal ARARs that regulate-and
control air emissions resulting from remedial actions including soil excavation and
treatment.
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UXO removed as pan of the cleanup (including those UXO found in the soil covere(i"or
ex~vated as pan of Alternatives 2 through 5) will be deactivated on site by detonation or
open burning in accordance with RCRA requirements and conditions of existing RCRA
interim swus pennit requirements at the ADA. These UXO are considered hazardous
wastes because their presence at the ADA is a result of a disposal action and because they
may have the characteristic of reactivity.
Two of the sites to be cleaned up at the ADA (Sites 16 and 32) are currently operating
under RCRA interim staws to allow for the ongoing destruction of ordnance and
propellant at UMDA. The cleanup described in this ROD will satisfy the requirements for
closure of these sites under RCRA guidelines (40 CFR 265 Subpart G). Typically with
RCRA closures, wastes left in place are capped and ground water wells are installed and
monitored for thirty years under post-closure care in order to ensure protection of ground
water. At Sites 16 and 32, wastes left in place are not considered a threat to ground
water. Therefore. remediation under this ROD is more appropriate because risk-based
levels will be met and post-closure care (including security and access resaictions) will be
provided as pan of thp' remedy.
2.8.2 Primary Balancing Criteria
Long-term effectiveness. Alternative 1 does not provide for any long-term risk
reduction and therefore does not demonstrate long-term effectiveness.
Under normal circumstances, soil covers such as those to be implemented in Alternative 2
may be long-term and permanent solutions to the spread of contamination. However,
they are considered less long-tenn and permanent than alternatives that involve treatment
of the contaminated soil. The imposition of institutional controls to limit access to and
use of the ADA will enhance the long-term effectiveness and permanence of this method
of containmenL
Alternatives 3 and 4 will result in the treatment of all contaminated soil, which offers
long-term effectiveness. This effectiveness is further enhanced by disposing of the
treated soil in a properly maintained and monitored landfill.
Alternative 5 results in the treattnent of only hazardous soils. Untreated soils will
continue to present risks that are only moderately reduced by their disposal in a
maintained and monitored landfill.
The removal of UXO (including those UXO found in the soil covered or excavated as
pan of Alternatives 2 through 5), effectively and permanently reduces the risks associated
with their presence. .
Reduction In toxicity, mobility, or volume 0' contaminants through treatment.
Alternative 1 does not reduce the toxicity, mobility, or volume of contaminants.
Alternative 2 does not involve the treatment of contaminated soils and therefore does not
achieve reductions in toxicity or volume of contaminants through treatment. However,
the mobility of contaminants is reduced in Alternative 2 by the addition of a cl~ soil
cover.
Alternatives 3, 4, and 5 wiil result in varying degrees of reducing the toxicity, mobility,
or volume of contaminants through treatmenL All of these alternatives result in the
46
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imIDobilization of contaminants (by trapping them in a concrete-like material); however,-
o~y Alternatives 3 and 4 will result in the immobilization of all contaminants.
Alternative 4 will result in the destruction of explosive contaminants by incineration,
thereby decreasing their toxicity and volwne.
The removal and deactivation of UXO will reduce the volume of contaminants present at
the ADA. .
Short-Ienn ettectJveness. Alternative 1 is effective in the near tenn, since public
access to UMDA is currently restricted. Operations associated with Alternative 2 are not
expected to increase the risks to the community since no contaminants will be released to
the environmenL Operations associated with Alternatives 3, 4, and 5 provide the
potential for risks to human health and the environment as they involve the removal,
handling, treatment, and ttanspon of contaminated soil and treated soil. Risks to the
environment as well as workers involved in the various activities of these alternatives will
be minimized through the application of proper engineering controls (such as wetting the
soil to minimize dust emissions) and the use of personal protective equipmenL
Alternatives 3 and 4 will present fewer risks to the community than Alternative 5 since no
actions are conducted off site.
Safety risks and hazards associated with the removal and deactivation of UXO will be
minimized by using trained safety personnel and maintaining adequate distances between
clearance operations and other activities.
Alternatives 2 through 5 and UXO clearance could be implemented in one to two years.
Implementability. There are no teChnical or administrative difficulties likely in
implementing Alternative 1 since no actions will be required. Activities involved in
carrying out Alternatives 2 through 5, as well as UXO clearance, have been successfully
used in other cleanups. Services, materials, and equipment are readily available for their
performance. Administrative difficulties are expected to be fewest for Alternative 3.
Solidification/stabilization will require treatability Studies to develop a chemical additive
mixture that will meet treatment requirements. Administrative difficulties are more likely
for Alternative 4, which requires a trial bum for incineration, and Alternative 5, which
involves the off-site transpon of hazardous soils.
Cost The estimated capital, O&M, and present wonh costs for each remedial alternative
are as follows:
Alternative
..1
2
3
4
5
CaDltal Cost
o
$ 290,000
$ 1,100,000
$ 3,400,000
$ 3,200,000
O&M Cost
o
$ 10,000
$ 1,300,000
$ 4,100,000
o
Present Worth Cost
o
$ 300,000
$ 2,400,000
$ 6,900,000
$ 3,200,000
Present wonh costs to conduct the various levels of UXO clearance evaluated are
esnm:ned as: ~
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2.8.3
Level 01 Clearance
Surface Qearance
Subsurface Clearance (to 1 foot)
Subsurface Oearance (to 5 feet)
Modifying Criteria
Present Wonh Cost
$ 1,212,000
$ 7,225,000
$13,700.000
State scceptance. The state of Oregon concurs with the Army and EP A in the
selection of Alternative 3 for the cleanup of contaminated soils at the ADA. In addition, .
the state concurs with the initial conduct of a surface clearance and detection of uxa and
the detection and quantification of subsurface UXO across the ADA (phase I clearance
actions), and with the Army's committnent for additional uxa clearance as necessary
consistent with the final land use designation for the ADA (Phase II clearance). The State
of Oregon Concunence Letter is provided in attachment B of this ROD.
Public acceptance. Based on the absence of any negative comments from the public,
the public supportS J1e selection of Alternative 3 as well as the phased approach to be
taken with respect to the removal and quantification ofUXO.
2.9 Selected Remedy
The selected remedy to clean up the soil contamination associated with the UMDA is
Alternative 3, On-Site Treattnent of All Contaminated Soil by Solidification/Stabilizarion
and On-Site Disposal. This alternative was selected because it is protective, feasible, and .
cost-effective. The specific steps to be employed in this cleanup include:
.
Excavation of approximately 14,000 cy of contaminated soil at ADA Sites 15,
17, 19,31, and 32 (Area II). UXO would be removed from these sites during
excavation as necessary to permit safe excavation and access. .
Treatment by a mobile solidification/stabilization system.
Disposal of treated soil from the solidification/stabilization system into the on-
site UMDA landfill. .
Restoration of excavated areas with clean backfill and vegetation.
.
.
.
In addition to the cleanup of contaminated soils. safety and environmental risks due to the
presence ofUXO will be quantified and reduced in two phases. as described below.
Phase I will consist of the following:
.
A metallic object survey will be conducted over the entire ADA to better
estimate the quantity of metallic debris that would have to be removed to clear
the ADA of possible ordnance (at an estimated cost of $1,800,(00).
Concurrently with the survey, a "visual sweep" will be conducted over the
entire surface of the ADA to locate and remove objects identifiable as ordnance
(at an estimated cost of $1,212,(00).
.
Phase II activities will be dependent upon the future reuse selected for the ADA.~ As pan
of the base closure process, future reuse for the ADA will be decided by DoD, the state of
Oregon. and the local community. When a suitable future reuse has been finalized,
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additional UXO clearance will be conducted to a depth that is protective for the final land
use (as shown in Table 11).
Upon completion of Phase II UXO clearance aCtions. appropriate institutional controls
will be applied to the ADA to pennanently limit the use of. and access to, the ADA
consistent with the fInal use selected for the area and the degree to which UXO are
cleared. Such controls may include deed restriCtions. maintenance of existing fencing,
and/or security. The present worth cost of permanently maintaining these conttols is
estimated at $1.000.000.
In summary. Phase I of the UXO removal will be conducted concurrently with the
cleanup of contaminated soil. Phase II will be initiated within 15 months after the final
land use and disposal decision is made on the ADA. .
In order to ensure that this cleanup remedy continues to be protective, a site review will
be conducted every five years. This review will include verifying that institutional
controls remain in place and that land use of the ADA has not changed. In addition. any
land transfer will be subject to CERCLNSARA Section 120(h) provisions.
. -
2.10
Statutory Determinations
The selected remedy satisfIes the following requirementS under Section 121 of CERa..A:
. Protect human health and the environment
. Comply with ARARs
. Be cost effective
. Utilize permanent solutions and alternative treattnent technologies or resource recovery
technologies to the maximum extent practicable
. Satisfy the preference for treannent as a principal element
o. -
.
~... 4"'~_""
. ... ~;:",
-
....,
2.10.1 Protection 01 Human Health and the Environment
The selected remedy, Alternative 3. will reduce risks posed to future users of the ADA
through treatment of excavated soils by stabilization/solidifIcation, followed by on-site
disposal of the treated soils in the UMDA landfill, and restoration of excavated areas with
clean backfill and vegetation. The clean backfill and vegetation will minimize direct
contact with any residual contamination remaining after excavation. Excavation of
contaminated soil followed by treatment and disposal of treated soil in a maintained and
monitored landfill should achieve the following: . .
. Health risks associated with exposure to caICinogens in the treated soil and in soil that
remains in place will be reduced to within the NCP's acceptable range of 1 x 104 to
I x lQ-6 (for an industrial use scenario). .
. Noncarcinogenic health risks will be reduced to levels at or below a hazard quotient of
one.
. Environmental protection is achieved by reducing contaminant concentrations and
providing a clean soil layer to support a vegetative cover.
. Health. safety. and environmental risks are reduced by removing UXO to a depth
consistent with the selected fina11and use, thereby significantly reducing the potential
for contact and accidental detonation.
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No unacceptable shon-tenn risks or cross-media impacts will be caused by -
implep}entation of Alternative 3 or removal and deteetion of UXO. During remediation,
adequate proteCtion will be provided to the community and the environment by
controlling dust generated during materials handling operations. In addition, workers will
be provided with personal protective equipment and air monitoring during all phases of
remediation. Safety risks and hazards associated with the removal and deactivation of
UXO will be minimized by using trained safety personnel and maintaining adequate
distances betWeen clearance operations and other activities.
2. 10.2 Compliance with ARARs
The discussion below addresses compliance of the selected remedy with chemical-
specific, location-specific, and action-specific ARARs.
Chemical-specific ARARs. The selected remedy complies with the state of Oregon
cleanup requirements as set forth in the Oregon Hazardous Substance Remedial Action
Rules. Although cleanup to background is not achieved., the feasibility of cleanup to
background was evaluated and considered not cost-effective. This alternative provides
the lowest residual contaminant levels feasible and protective for futUre industtial use of
the ADA.
The selected remedy complies with RCRA requirements regarding the identification and
listing of hazardous waste (40 CFR 261.3); and land disposal restrictions (40 CFR 268).
Location-specific ARARs. The selected remedy complies with requirements of the
Endangered Species Act (40 CFR 502) to ensure that no remedial actions will proceed
that will negatively affect endangered or threatened species.
Action-specific ARARs. The selected remedy complies with state of Oregon Air
Pollution Control Regulations that require control of emissions involved in the excavation
and handling of contaminated soil.
The selected remedy complies with RCRA requirements regarding the design and
operating standards for treatment unitS (40 CFR 264); standards applicable to generators
of hazardous wastes (40 CFR 262); and closure requirements for interim statUs units
(40 CFR 265 Subpan G). .
2.10.3 Cost-Effectiveness
The selected remedy provides overall effectiveness proportionate to itS costS. As pan of
the evaluation of cost-effectiveness, the state of Oregon requirement to determine the
feasibility of cleanup to background was considered. The feasibility of cleanup to
background was evaluated by estimating costs to clean up all the ADA to standards based
on residential land u~ that most closely matCh background levels. In this estimate it was
determined that approximately 33,000 cy of soil would require treatment. CostS of
implementing Alternative 3 to clean up this volume of soil total $4,800,000. This cost is
tWice that required to achieve cleanup of chemically contaminated sites to meet industrial
futUre use standards at the ADA. Because it is not reasonably foreseeable that the ADA
will be used for futUre residential use, it has been determined that the additional cleanup
cost to reach residential (or background) standards is not cost-effective.
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2.10.4 Utilization of Permanent Solutions and Alternative Treatment
Technologies or Resource Recovery Technologies to the Maximum
Extent Practicable
The selected remedy is a pennanent solution that provides the best balance of tradeoffs
among the alternatives. Alternative 1 fails to meet the threshold criteria of overall
protection and compliance with ARARs and is thus clearly unacceptable. Although
Alternative 2 provides a degree of overall protection, it does not comply with ARARs.
Alternatives 3. 4, and 5 meet the threshold criteria. These alternatives are comparable in
termS of shan-term effectiveness and implementability. These alternatives differ in terms
of degree of proteCtiveness afforded and cost. Alternatives 3 and 4 provide a greater
degree of proteetiveness than Alternative 5 since they involve the treatment of all
contaminated soil excavated from the ADA siteS. Alternative 3 is the lowest cost of these
three alternatives. Alternative 3 is the least costly of these alternatives, and since it meets
all of the criteria of the protective alternatives, its selection as the selected remedy is
justified.
The selected remedy meets the statutory requirement to utilize permanent solutions and
alternative treatment technologies to the maximum extent practicable.
2.10.5 Preference for Treatment as a Principal Element
The swutory preference for treatment is satisfied by using stabilization/solidification to
treat all contaminated soil excavated from the ADA sites.
2.11 Documentation of Significant Changes
The selected remedy was the preferred alternative presented in the Proposed Plan. No
changes have been made.
! I
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3.0 Responsiveness Summary
The final component of the ROD is the Responsiveness Summary, which selVes two -
purposes. First, it provides the agency decision makers with infonnation about -
community preferences regarding the remedial alternatives and general concerns about the
site. Second, it demonstrates to members of the public how their comments were taken
into account as pan of the decision-making process.
As pan of the installation's community relations program. the UMDA command
assembled in 1988 a TRC composed of elected and appointed officials and other
interested citizens from the surrounding cormnunities. Quarterly meetings provide an
opponunity for UMDA to brief the TRC on insWlation environmental restoration projects
and to solicit input fron1 the me. Two TRC meetings were held that included
presentations and discussions on the remedial alternatives considered and evaluated as
pan of the feasibility study for the ADA Operable UniL
In December 1993, the TRC was expanded to a Restoration Advisory Board (RAB) in
accordance with DoD guidance. Two RAB meetings were held during the selection of
the proposed cleanup alternative for the ADA.
The Feasibility Study and Proposed Plan for the ADA Operable Unit were made available
to the public on February 15, 1994. These documents were made available at the
following locations: UMDA Building 32, Henniston, Oregon; the Henniston Public
Library, Henniston, Oregon; and the EPA office in Portland, Oregon. Notice of the
public comment period, public meeting, and availability of the Proposed Plan was
published in the Hemrislon Herald, the Tri-City Herald, and the East Oregonian in
February 15, 1994. The public comment period ended on March 17, 1994.
A public meeting was held at Annand Larive Junior High School, Hermiston, Oregon,
on March 2, 1994, to inform the public of the preferred alternative and to seek public
comments. At this meeting, representatives from UMDA, USAEC, EPA, ODEQ, and
Arthur D. Linle, Inc. presented the proposed remedy. Approximately 10 persons from
the public and media attended the meeting. There were no questions asked during the
informal question and answer period specific to the Proposed Plan for the ADA.
A formal statement regarding the Proposed Plan for the ADA was made by a member of
the Oregon National Guard (ONG). This statement was made to convey a preliminary
interest in the future use of the ADA for ONG ttaining purposes. A potential future use
of the ADA under consideration by the ONG includes the use of a 2,000 meter by 2,000
meter area for tracked vehicles and maintaining other ADA property as an impact area.
Two written comments were received during the comment period and expressed concern
about the incineration of explosives and weapons on site at UMDA. The comments were
not addressed to a specific operable unit; however, they appear to relate specifically to the
Explosives Washout Plant Operable Unit since the proposed remedy for the cleanup of
that site involves the thermal oxidation of explosive contaminants in an afterburner. No
aspect of the proposed cleanup for the ADA involves incineration.
52
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Aftachment A
S~te Investigation and Assessment Documents
The following documentS contain the resultS of the site investigation and assessments of
cleanup actions for the ADA. These documentS were made available to the public at the
infonnation repositories located at UMDA Building 32, Hermiston, Oregon; the
Henniston Public Library, Henniston, Oregon; and the EP A offices in Ponla.nd. Oregon.
RemediiJil nvesngarion Repon for the UmDlilla Depot Activity, Hermiston, Oregon.
Prepared by Dames & Moore for the U.S. Army Toxic and Hazardous Materials Agency,
1992.
HUI7Uln Health Baseline Risk Assess1nent Umatilla Depot Activity, Hermiston, Oregon.
Prepared by Dames & Moore for the U.S. Army Toxic and Hazardous Materials ~.;.ency,
1992.
Ecological Assessment (EA) Repon, Umatilla Depot Activity, Hermiston, Oregon.
Prepared by Dames & Moore for the U.S. Anny Toxic and Hazardous Materials Agency,
1993.
Feasibility Study for the Ammunition Demolition Activity Area (Operable Unit 4) at the
UmatUla Depot Activity. Prepared by Arthur D. Little, Inc. for the U.S. Anny
Environmental Center, 1993.
53
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Attachment B
State 01 Oregon Letter 01 Concurrence
.
54
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o i .. 26 ." 9 -I
15; us
'8'229 5830
E(1)
III oo:!
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Gregor
f
July 26. 1994
Mr. Chuck Clarke
Regional Administrator. Region 10
U. S. Environmental ProteCTion Agency
'200 Six,1.h Avenue
Seanle. WA 98101 "
DEPAR'rME~T 0:
ENVTROr-.iMENTA;
QUl\LlTY
Re:
Umatilla Depot ACtivity
Ammunition Demolition Activity
Operable Unit
Record of Decision
Dear Mr. Clarke:
The uregon Department of Environmental Quality (DEQ) has reviewed the final RecOrd of
Decision. tor the Ammunition Demolition Activitv (ADA) Area Operable Unit at the U.S. Army's
Umatilla Depot Activity (UMDA). I em pleased to advise you that DEO concur6 with the
remedy recommended by EPA and the Army. The major components of that remedy include:
.
Excavation of contaminated soil from Sites number 15. 17. , 9. 31, and 32
(approximately 14.000 cubic yards of soil). Unexploded ordnance (UXO) would be
removed from these sites as necessary to allow safe access and soil excavation:
.
Treatment of contaminated soil by solidification/stabilization to produce a cement-like
soil mixture;
.
Disposal of the treated soil in the UMOA Active Landfill: and.
.
Replacement of excavated soils with clean soil and revegetation of the area.
10 addjtion~ a phased approach will be taken to locate and remove UXQ from the entire ADA.
area to a level that is consistent with the futUre land use selected for the ADA area. FoUowing
those actions. institutional controls will be apptied to permanentfy control access to and use
of the ADA area. consistent with the final land use selected.
I find that this remedy is protective. and to the maximum extent practicable is cost effective,
uses permanent solutions and alternative technologies. is effeCtive and" implememable.
Accordingly. it satisfies the requirements of ORS 465.315,and OAR 340-122~40and 090.
.
.
811 SW Sixth Avenue:
PonhuId. OR 972t)4.139t
(503) 2.29-5696
roD (503) 229-6993
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u;:26..9~
15;19
"5'229 5S30
E(1)
141 003
- --
ChUCK Clarke
Page 2
It is understood that placement of any treated wastes from this operable unit into the Depot's
Active Landfill is subject to the reQuirements of the permit for the landfill, previously iSSued
by this Department.
!
If you have any Questions concerning this maner, please contact Bill Dana of DEQ's Waste
Management and Cleanup Division at (503) 229-6530.
Sincerely,
~~~,
Fred Hansen.
Director
80:111
SITE\SM5939
cc: Lewis D. Walker, 000
LTC. Moses Whitehurst, Jr..
Harry Craig, EPA..()OO
Jeff Rodin, EPA. Seattle
Bill Dana, DEONJMCD
Stephanie Hallock, DEOIERQ
.UMDA
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