United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R10-93/065
August 1993
SEPA Superfund
Record of Decision:
Umatilla Army Depot (Lagoons)
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REPORT DOCUMENTATION 11. REPORT NO. 2. ' 3. Reclplent'e Acc88810n No.
PAGE EPA/ROD/R10-93/065
4. Thle end Subth" 5. Report Date
SUPERFUND RECORD OF DECISION 08/10/93
Umatilla Army Depot (Lagoons) (Operable Unit 5), OR 6.
Third Remedial Action
7. Author(8) ... 8. Performing Organization Rept. No.
9. Performing Organization Nama and Addr- 10 Project Taak/Work Unh No.
11. Contract(C) or Grant(G) No.
(C)
(0)
12. Sponsortng' Organization Nama and Add,..8 13. Type of Report & Parlod Cova.
U.S. Environmental Protection Agency
401 M Street, S.W. 800/800
Washington, D.C. 20460 14.
15. Supplementary Notee
PB94-964613
16. Abstract (Llmh: 200 words)
The 5-acre Umatilla Army Depot (Operable Unit 5) site is part of a 19,700-acre military
installation located approximately 10 miles west of Hermiston, in both Morrow and
Umatilla Counties, Oregon. This installation was established in 1941 as an Army
Ordn'ance Depot to store and handle munitions. Land use in the area is predominantly
agricultural, with approximately 1,000 residents in each of the bordering farm
communities of Umatilla and Irrigon. Hermiston, with a population of approximately
10,000 residents, is the largest local population center. The local residents use the
estimated 1,470 wells, located within a 4-mile radius of the site, to obtain their
domestic and irrigation water supply, and three municipal water systems to obtain their
drinking water supply. Due to its large size, the number of sites, and the variety of
potential contaminants, the installation was divided into eight OUs. From 1950 to
1968, prior to its use as a landfill, OU5 was operated as a gravel pit. Since 1968,
the Army has operated the landfill and, in 1979, received a landfill permit from the
State. Materials disposed of at the site include garbage, demolition debris, asbestos
from brake linings" dried sludge from the sewage treatment plant, explosives sludge,
and possibly ash from the Deactivation Furnace. Over the past 15 years, several
investigations have been conducted at the installation. In 1988, the initial field
(See Attached Page)
17. Documant Analye.. a. Da8c:rlptors
Record of Decision - Umatilla Army Depot (Lagoons) (Operable Unit 5), OR
Third Remedial Action
Contaminated Medium: None
Key Contaminants: None
b. IdentilieralOpan-Endad Tarms
c. COSATI Field/Group
18. Availability Statement 19. Security Class (This Report) 21. No. of Pages
None 53
20. Security Class (ThIs Page) 22. Prtce
None
50272-101
(See ANSI-Z39.18)
See InstrucUons on RIIVIlfS8
OPTIONAL FORM 272 (4.77)
(Formerty NTI5-35)
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EPA/ROD/RIO-93/065
Umatilla Army Depot (Lagoons)
Third Remedial Action
(Operable Unit 5), OR
Abstract (Continued)
investigation for OU5 was conducted, which indicated contamination of ground water in the
vi~inity of the landfill with slightly elevated levels of organic compounds, .inorganics,
and metals. Subsequent investigations did not confirm the presence of the organic
compounds; however, they did confirm the presence of elevated levels of one inorganic
compound and metals in ground water. Although organic contamination was not detected in
subsequent rounds of sampling, the potential health risks associated with these
contaminants were evaluated, along with the health risks associated with inorganics and
metals. A 1992 ROD addressed the Explosive Washout Lagoons Soils, as OU2.. Two 1993 RODs
addressed the Deactivation Furnace and the Inactive Landfills, as OUs 1 and 8,
respectively. Future RODs will address ground water across the installation and three
additional OUs. This ROD addresses the Active Landfill at the installation, as OU5.
Results of site evaluations indicated that contamination associated with the Active
Landfill does not pose any unacceptable risks to human health and the environment;
therefore, there are no contaminants of concern affecting this site.
The selected remedy for this site is no aqtion because site investigations indicated that
contamination associated with this site poses no threat to human health or the
environment. The site is scheduled for closure within the next two years and will be
subject to State closure requirements that include capping, post-closure ground water
monitoring for five years, and restrictions preventing excavation and construction at the
site. There are no present worth or O&M costs associated with this no action remedy.
PERFORMANCE STANDARDS OR GOALS:
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Defense environmental
Restoration Program
,
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Record 01 DecisIon
FlnaJ
Umatllla Depot Activity
ActIve Landflll
Operable Unit
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Revision 1
March 1993
In accordance with Army Regulation 200-2. this document is intended by the Army to
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Table 01 Contents
Acronyms and Abbreviations
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III
1.0 Declaration 01 the Record 01 Decision. . . . . . .. . . . . . . . . . . . . . . . . . . .
Site Name and Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Statement of Basis and Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Description of the Selected Remedy. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Declaration Statement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
1
1
I
3
2.0 Decision Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8
2.1 Site Name, Location, and Description. . . . . . . . . . . . . . . . . . . . . . .. 8
2.2 Site History and Enforcement Activities. . . . . . . . . . . . . . . . . . . . . " 9
2.3 HighlightS of Community Participation. . . . . . . . . . . . . . . . . . . . . . '. 11
2.4 Scope and Role of the Operable Unit or Response Action. . . . . . . . .. 12
2.5 Summary of Site Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . .. 13
2.6 Summary of Site Risks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 27
2.7 Description of the "No-Action" Alternative. . . . . . . . . . . . . . . . . . .. 38
2.8 Documentation of Significant Changes. . . . . . . . . . . . . . . . . . . . . " 39
3.0 Responsiveness Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 40
Appendix 1: State 01 Oregon's Letter of Concurrence. . . . . . . . . . . . . . . . .. 41
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Table 01 Contents (continued)
Figures
Figure 1: UMDA Facility Location Map. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2
Figure 2: Overview of UMDA Layout: . . . . . . . . . . . . . . . . . . . . . . . . . . . " 10
Figure 3: Active Landfill. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 14
\
Tables
Table 1: Contaminants Detected in Ground Water in the Active Landfill Area
Phase I Investigation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " 16
Table 2: Ground Water Analytical ResultS Phase 2 Investigation Active Landfill. 18
Table 3: Summary of Interpretation of Ground Water Analytical Data. . . . . . .. 26
Table 4: Occurrence and Distribution of Compounds Evaluated in the Active
Landfill Risk Assessment. . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . .. 30
Table 5: Summary of Toxicity Criteria for the ContaminantS of Concern at the
Active Landfill. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 31
Table 6: Multiple Pathway Potential Carcinogenic Risks and Noncarcinogenic
Hazards at the Active Landfill Future Residential Land Use Scenario.. 34
Table 7: Potential Carcinogenic Risks and Noncarcinogenic Hazards Due to
Ingestion of Ground Water at the Active Landfill Future Residential
Land Use Scenario. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 35
Table 8: Potential Carcinogenic Risks and Noncarcinogenic Hazards Due to Denna!
Absorption of Ground Water Contaminants at the Active Landfill Future
Residential Land Use Scenario. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 36
Table 9: Potential Carcinogenic Risks and Noncarcinogenic Hazards Due to the
Consumption of Crops at the Active Landfill Future Residential Land
Use Scenario. . . . . . . . . . . . . . . . . . . . . . . . . . . : . . . . . . . . . . . . .. 37
87OII2I1TEP .AOO.ACTIYE.c::nM3
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Acronyms and Abbreviations
.;
ADA
ALOU
ARARs
BRAC
CERCLA
CFR
CPF
DoD
2A-DNT
2,6-DNT
EPA .
FFA
FS
MSL
NA
NCP
NPL
ODEQ
OU
PCBs
RCRA
RDX
RID
RI
ROD
SARA
TAL
TRC
UMDA
USATHAMA
Amunition Demolition Activity
Active Landfill Operable Unit
Applicable or Relevant and Appropriate Requirements
Base Realignment and Closure
Comprehensive Environmental Response. Compensation, and Liability
Act of 1980
Code of Federal Regulations
Cancer Potency Factor
Dep~ntof~ren~
2,4-Dinitrotoluene
2,6-Dinitrotoluene
Environmental Protection Agency
Federal Facilities Agreement
Feasibility Study
Mean Sea Level
Not Applicable
National Contingency Plan
National Priorities List
Oregon Deparnnent of Environmental Quality
Operable Unit
Polychlorinated-biphenyls
Resource Conservation and Recovery Act
Hexahydro-l,3,5-trinitto-l,3,5-triazine (Royal Demolition Explosive)
Reference Do~
Remedial Investigation
Record of Decision
Superfund Amendments and Reauthorization Act of 1986 .
Target Analyte List
Technical Review Committee
U.S. Army Depot Activity at Umatilla
U.S. Army Toxic and Hazardous Materials Agency
8708281 TEP.AOO.ACTM:.CD2M13
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Section 1
Declaration of the Record of Decision
Site Name and location
.'
V.S Army Depot Activity, Umatilla
Active Landfill Operable Unit
Hermiston, Oregon 97838-9544
Statement 01 Basis and Purpose
This Decision Document presents the selected n~action remedial alternative for the
Active Landfill Operable Unit at the U.S. Anny Depot Activity, Umatilla (UMDA) in
Hermiston, Oregon (Figure 1). This alternative was chosen in accordance with the
Comprehensive En~nmental Response, Compensation and Liability Act (CERG.A)
of 1980, as amended by the Superfund Amendments and Reauthorization Act (SARA)
of 1986, and to the extent practicable, the National Contingency Plan (NCP) (40 CFR
Part 300 et ~., 1992; and 55 Federal Register 8666, March 1990), as amended. This
decision is based on information contained in the administrative record file for this sire.
The remedy was selected by the U.S. Army (Army) and the U.S. Environmental
Protection Agency (EPA). The State of Oregon Department of Environmental Quality
(ODEQ) was given the opponunity to participate in the review and decision process and
concurs with the selection of a n~action remedy for this site.
Description of the Selected Remedy
The Active Landfill Operable Unit (ALOU) is one of eight operable unitS at UMDA.
The other operable unitS are: Explosives Washout Lagoons Soils; Deactivation Furnace
Soils; Inactive Landfills; Explosives Washout Lagoons Ground Water; Ammunition
Demolition Activity (ADA) Area; Miscellaneous UMDA SiteS; and Explosives Washout
Plant (Building 489). Four of these operable units are at the Record of Decision (ROD)
stage, the rest are still in the Remedial Investigation/Feasibility Study (RIlFS) process.
The four operable unitS at the ROD stage are: the Explosives Washout Lagoons Soils
(which has a signed fmal ROD); the Deactivation Furnace Soils; the Inactive Landfills;
and the five acre Active Landftll, which is addressed in this ROD.
The Army, EPA, and ODEQ have selected "No Action" as the remedy for the Active
Landfill Operable Unit at UMDA. in Hermiston, Oregon. This selection was made based
upon information generated during the RI which indicates that the site does not pose an
unacceptable threat to human health and/or the environment. The landfill is scheduled
to: cease receipt of municipal waste in 1993; cease receipt of aU marerials in 1994; and
go through formal closure in accordance with ODEQ regulations in late 1994. A low
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;:>errneabiliry soil cap will be placed on the landfill and ground water at the site will be
;nonitored for a minimum of five years after closure of the landfill to ensure that the
landfill does not have a significant negative effect on local ground water quality.
Dectaratlon Statement
..
Data gathered during the RI of the ALOU. and the results of the evaluation of that data
in the human health risk assessment. indicate that the ALOU in its CWTCnt condition
does nOt pose an unacceptable risk to human health or the environmenL The data also
indicate that future residential land use at the site would not result in an unacceptable
risk to public health or the environmenL It has therefore been detennined that remedial
3.Ctiviries are not necessary to ensure the protection of human health and the environment
at the ALOU. It has also been detcnnined that a five-year review of the selected remedy
will be performed. The ground water quality data collected over a five year monitoring
period. as required by Oregon State Solid Waste Regulation. will be evaluated and
interpreted to assure that the landfill has no negative affect on ground water quality; and
that the selected remedy is sufficiently protective of human health and the environment.
.-
87'01128'TCP.~..IICTM:.~
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..
Lead and Support Agency Acceptance
.01 the Record of DecisIon,
U.S. Army Oe~t Activity UmatlUa,
Active landfill Operable Unit
December 1992
RECEIVED
DEC 2 2 1993
SUPEBtilhu ntMEDlAL BIIANCH
Sign4itUrC sheet for the fo~going Rccord of Decision for the Active:: Landfill Operable
Unit fin.u action at the U.S. Army Depot Activity at Umatilla by the U.S. Ann)' and the
U.s. Environmental Protectio~ Agency. with the concurrence of the Swc of Oregon
Dcpanmcnt of Environmental Quality.
. .~
I.kJiJJJfi£1ii .
Lieutenant Colonel :Moses i.tehurst ;Jr_~.
Commander. U.S. Army Depot Activity. Umatilla
/7~~1m
Dace .
,""
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-------
"
Lead and Support Agency Acceptance
oC the Record of Decision,
U.S. Army Depot Activity Umatilla,
Active Landfill Operable Unit
December 1992
Signature sheet for the foregoing Record of Decision for the Active Landfill Operable Unit
final action at tbe U.S. Army Depot Activity Umarilla by the U.S. Army and the U.S.
Environmental Protection Agency, with the concurrence of the State,of Oregon Depanment
of Environmental Quality.
~{J! ~
Gerald A Emison
Acting Regional Administrator, Region 10
U.S. Environmental Protection Agency
8-(0- r2
Date
-------
.
. Lead and Support Agency Acceptance
of the Record of DecJslon,
U.S. Army Depot Activity UmatJlJa,
AcUve Landfill Operable Unit
December 1992
Signamrc sheet for the foregoing Record of Decision for the Active L1nnfl11 Operable
Unit final acri.on at the U.S. Army Depot ACtivity at Umarma by the U.S. AmJy and the
U.S. Environmental Protection Agency, with the concmrence of the Swc of Oregon
Dcpamncnt of Environmental Quality. .
~ - -----
7~~"'~A...- ~ /~~ ,~
Fmi J ~~ 1 /
cnc J. Han~n
Dircacr
Oregon Department of Envirnnm~tal Quality
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Dare
Note: The. Swc of Oregon's Leuer of Concum:ncc is appended (0 this Record of
Decision.
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Lead and Support Agency Ac~tance
at the Record of Decision,
U.s. Army Depot ActIvity UmatiJJ~
ActIV& ~ndfUi Opef3Dle Unit
..
Sigmmm: sheet far the fOR:going Record of Decision for the Aaivc I ~nrifi1t Operable
Unit final action at the U.s. .AImy Depot Activity at U~1nITn .bcnw~ the U.S. AImy
ami the U.s. Environmt!nr.lt Pro~OD Agem:y, with the CCI1L.~I;i~ of the S~ of
Oregon Dcpamm:m of En,,~~ttal Quality.
~2),tJ~
Lewis D. Walker
DepUtY Assiscm[ Secr::my of the Army
(EnVIrOnment. Safety. and Occupational Health)
/2/29/92-
December 1992
,---
.
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Section 2
Decision Summary
This Decision Summary provides an overview of the characteristics of the Active
Landfill Operable Unit (ALOU) at the U.S. Anny Depot Activity, Umatilla (UMDA),
and the environmental assessment activities that have been perfonned. The rationale used
to choose the selected remedy is then presented.
2.1 Site Name, Location, and Description
UMDA is located in Morrow and Umatilla Counties in rural, northeastern Oregon.
UMDA is approximately 10 miles west of Henniston; one to two miles west of the
Umatilla River; 175 miles east of Ponl~d; and two miles south of the Columbia River.
The town of HennistOn, with approximately 10.000 residents is the largest local
population center. Irrigon and Umatilla which border UMDA to the northwest and
northeast. respectively. are fanning communities of less than 1,000 residentS each
(Figure 1).
Topography across UMDA rises gently to the south with distance from the Columbia
River. Elevations range from 410 feet Mean Sea Level (MSL) near the northwest comer,
to 660 feet (MSL) to the southwest The most significant geologic feature at the site is
Coyote Coulee which trends southwest-northeast across the eastern half of UMDA. It
is a sedimentary structure, a sand wave, deposited during a historic catastrophic flooding
event. The site is located on relatively penneable glaciofluvial sedimentary depositS
consisting of fIne to coarse sand. and gravel with increasing silt with depth. The sand and
gravel deposits are underlain" by the Columbia River Basalt Group. The area can be
characterized as semi-arid, receiving only eight to nine inches of precipitation annually.
The relatively low precipitation in conjunction with the high permeability of the geologic
material present resuJt in very minimal surface drainage. There are no streams or surface
water bodies at UMDA. Man-made canals built to recharge local ground water are the
most prevalent small scale surface water features in the local area.
UMDA was originally established as an Anny ordnance depot in 1941 for the purpose
of stOring and handling munitions. Access is currently restriCted to military personnel
and authorized contractors. However. the conventional ordnance storage mission at
UMDA bas been transferred to another installation as pan of the Depanment of Defense
(DoD) Base Realignment and Closure (BRAC) program." Under this program. it is
possible that the AImy will eventually close the site after the scheduled Chemical
Stockpile Demilitarization mission is completed; ownership could then be relinquished
to another governmental agency or private interest Light industry is considered to be the
most likely future land use scenario; future residential use is also a possibility.
Land use surrounding the UMDA facility is primarily agricultural. Regional crops
include potatoes. alfalfa, com. wheat, onions. asparagus, apples, grapes. and
watennelons. There are also some cattle and hog f~s. The influence. of the agricultural
activities on UMDA is most pronouncCd in the southern portions of UMDA where the
8708281 TEl' .AOO.JICTNE.CXW28IIO
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_. "... .- . ..'. ... ..
direction of ground water flow is obser..red to vary 180 degrees from its natural nonhem
direction when nearby irrigation wells are pumping. In addition. agricultural activities
are pelieved to be responsible for the elevated nitrate concentrations observed in the
ground water at UMDA.
Approximately 1,470 wells have been identified within a four-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 four-mile
radius of UMDA. The Columbia River is a major source of potable and irrigation water
and is also used for recreation, fIshing and the generation of hydroelecnic power. The
principal use of the Umatilla River is irrigation.
The ALOU is comprised of one five acre disposal area located in the nonheastem
portion of UMDA, near the eastern border, in a former gravel pit approximately one-half
mile east of the Coyote Coulee. The disposal area consists of a depression of
approximately fifty feet in depth. The landfIll is located between areas known at UMDA
as storage igloo blocks E and D, respectively (Figure 2).
The Army has operated the landfLlI since 1968. The ODEQ issued a landfill permit to
the Army in 1979. The permit was renewed in 1982. Municipal waste from the UMDA
facility is disposed at the site and covered on a weekly schedule. Debris generated by
"TIaintenance such as clearing and renovation activities are also brought to the site
,,:casion. The number of personnel and extent of activity at UMDA have been
"1~nificantly reduced over the last 20 years, thereby reducing the volume of .material
placed in the landfill. The peak work force present at UMDA was when the active
landfill was first opened. During the Viemam conflict. approximately 1,000 people were
employed at UMDA. However, by 1970 the work force began to decline and by 1987
the work force had fallen to 3 military and 250 civilian employees. Presently there are
about 200 people e,,-ioyed at UMDA.
A more complete description of UMDA and the ALOU can be found in the RI report
which is pan of the Administrative Record for this operable unit The Administrative
Record is available [0 the public through the information repositOries which are located
at the Umatilla Depot ACtivity Public Affairs Off1Ce, the Hermiston Public Library, and
at EPA Oregon Operations OffIce in Ponland, Oregon.
2.2 Site HIstory and Enforcement Activities
2.2.1 Site History .
The Active Landfill at UMDA has been operi"and receiving waste since 1968. Formerly,
during the period from 1950 through 1968, the ALOU was operated as a gravel pit
Materials disposed at the site include garbage, demolition debris, asbestos from brake
linings, dried sludge from the sewage treatment plant. and possibly ash from the
Deactivation Furnace and explosives sludges.
87082111 ta' .ROOXTNE.CX1'2M3
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ADA area 6 4 Admin.
Active LaDdnU '. Area ~
-
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Deactivation furnace ..;;;;; --
-
Sewage trealmenl planl
. Conventional muniLions SLOra e i 100 blocks Approximule sc . "- .
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4
5
6
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K Chemical munitions slOrage igloo blocks
ale. I - 4000
Figure 2: Overview of UMDA Layout
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U~1.DA was included in the Army's Installation Restoration Program in October 1978.
An lnirial Installation Assessment was performed in December 1978. to evaluate the
potential for past and present base operations to affect general environmental quality at
and around the base. This investigation mentioned the ALOU. but did not recommend
any funher action.
In 1985, the Army submitted an application to the EPA for approval of plans to
consttuct and operate an incinerator for chemical munitions desttuction. To receive
approval, EP A required that corrective actions be ta1cen at the site of all previous
releases of hazardous materials that had occurred at UMDA. EPA conducted a Resource
. Conservation and Recovery Act (RCRA) Facility Assessment to identify all areas that
may require corrective action. EPA released a final repon in July 1987, summarizing
their results. This repon listed the active landfill as one of the areas that should be
addressed. In response, the Army and Argonne National Laboratory jointly developed
a work plan to address the EP A's concerns.
Based primarily on contamination discovered at the Explosives Washout Lagoons, (a site
being addressed in another operable unit at the base), UMDA was placed on the National
Priorities List (NPL) in July of 1987. In 1989, a Federal Facilities Agreement (FFA) was
signed formally identifying the Anny as the lead organization responsible for taking
environmental response actions at UMDA. The FF A provided the framework for the
response actions and specified 33 sites. identified by EPA during their RCRA Facility
Assessment. that required action. Since that time, the Army has been working with
various environmental engineering and consulting £inns to ensure that all of the
identified sites are characterized and appropriate corrective actions are taken.
The Active Landfill will cease receipt of municipal waste on OctOber 9, 1993, but may
receive treated soil from the Deactivation Furnace Area unrillate 1994. The Anny is in
the process of designing a closure plan for the landfill in accordance with its permit and
ODEQ Solid Waste regulations and guidance. In general. the landfill will be covered by
a cap of compacted soil that will be a minimum of 18 inches in thickness. The cap must
have a penneability no greater than 10-5 cmIsecond.
2.2.2 Enforcement Activities
There have been no enforcement actions taken regarding this site.
2.3 Highlights of Community PartlclpatJon
A Public Involvement and Response Plan for UMDA was prepared in May of 1990 to
meet the public participation requirements of CERCLA. This plan includes a general
discussion of the site and community background. and outlines the goals and objectives
of the public involvement plan. Activities designed to ensme that the public is
adequately infonned of UMDA environmental conditions include, for example:
.
Public meetings to discuss issues of concern and project activities. Thus far. tWo
public meetings have been held to discuss the progress of the environmental
investigation of the UMDA.
17OI2I1TEP .ROO.ACTIVE.CXW2MCI
-------
. "". .. .
. .-...... ...
""'...." '.
Technical Review Committee (TRC) meetings. to keep local officials and interested
panies informed. The TRC is made up of local officials. as well as local interested
citizens. These meetings have been held. one every quaner. since February of 1989.
There have been 15 such meetings to date.
..
.
Written communication, fact sheets and press releases to inform the public of
milestones achieved in the environmental investigation of UMDA, request their
panicipation in TRC meetings or community interviews or inform them of remedial
activities, public meetings or any otheJ;' items of note.
.
Interviews of local citizens to detennine their level of awareness of site activities.
Public comment periods of not less than 30 days on proposed remedial actions.
.
A local information repository (the administrative record) available for the public
. to review.
A summary of the ALOU Proposed Plan was presented to the TRC on August 1~ 1992.
The Proposed Plan was released for a 30-day public comment period extending from
August 31, 1992 to September 30 1992. A public meeting was held at the Armand
Larive Junior High School in Henniston on September 15, 1992 to solicit input on the
no action alternative proposed for the sire. At the meeting. a summary of the results of
the RI was presented and representatives from the Army, EPA, ODEQ, and Arthur D.
Little, Inc. (an environmental engineering consulting firm) gave the public an
opponuniry to ask questions about the site and the proposed remedial alternative. A
responsiveness summary which should include comments received and the Army's
response(s) is attached at the end of this document. However, no comments or questions
were received during the comment period. The remedy documented in this ROD has not
been modified from the preferred alternative presented in the Proposed Plan.
2.4 Scope and Role of the Operable Unit or Response Action
Due to its large size, the variety of potential contaminants and the number of discrete
sites, UMDA has been divided into the following eight Operable Units (OUs):
.
Inactive Landfills OU;
Active Landfill OU; .
Explosives Washout Lagoons Ground Water au;
Ammunition Demolition Activity (ADA) Area Sites OU;
Miscellaneous UMDA, . Sites OU;
Explosives Washout Plant (Building 489) OU;
Explosives Washout Lagoons Soils OU; and
Deactivation Furnace Soils OU.
.
.
.
.
.
This ROD addresses the Active Landfill OU. A prefemd remedy has also been selected
for three of the other OUs. The soils at the Deactivation Furnace Soils au are
contaminated with metals. primarily lead. The proposed remedy will require that soils
87'0II2II1 TEl' .ROOJICTNE.03I2IIIa
-------
containing 500 mg/kg or more of lead be excavated and treated by stabilization!
solidification. The option currently proposed for the treated soil is disposal in the Active
Landfill.
A no-action remedy has been selected for the Inactive Landfills OU. Data gathered
during the RI indicates that actions to protect human health and the environment are not
necessary .
The Explosives Washout- Lagoons Soils OU was the subject of a final ROD in
September 1992 that selected composting to remediate the explosives-contaminated soils.
The rest of the OUs at UMDA are currently at the remedial alternative evaluation and
feasibility study phase of activity.
This ROD addresses the Active Landf1l1 at UMDA. Based on the resultS of the RI.
which includes the resultS of the risk assessment, the Army, EP A and ODEQ detennined
that the ALOU did not pose an unacceptable risk to human health or the environment;
consequently, a FS of possible remedial alte~atives was not necessary. It was decided
that sufficient information had been collecteri during the RI to justify proceeding directly
[0 the Proposed Plan.
Because the landfill was detennined not to pose a significant threat or to be a significant
source of contaminantS. the Anny, EP A. and ODEQ have selected no-action as the final
remedy for this OU. Although no further action will be taken under CERQA. the site
is scheduled to be closed and capped in accordance with ODEQ requirementS over the
next tWo years. As pan of ODEQ closure requirementS, ground water quality around the
site will be monitOred for a minimum of five years after closure [0 ensure that it is nOt
being negatively affected by the landfill.
2.5 Summary of Site Characteristics
Over the last 15 years. several environmental investigations have been perfonned at
UMDA. There have been tWo significant efforts directed specifically at the Active
Landfill. These investigations consisted of both record and field investigations.
The records investigations included review of aerial phOtOgraphs of the site dating from
1950 through 1980 and existing files and disposal records to gather information on
general site activities. Interviews of former UMDA employees were also conducted to
better define the materials disposed at the site. .
The initial field investigation was performed in 1988 and involved the installation and
sampling of four ground wale!' monitoring wells (Figure 3). These wells were installed
into the alluvial aquifer. The samples were analyzed for the presence of explosives,
volatile organic compounds, semi-volatile organic compounds. pesticides. priority
pollutant metals, cyanide, and several inorganic indicator compounds. Because the
landfill is currently active. and will soon cease receipt of waste and be capped. soil
samples were not collected. The data they would provide would be of limited value
because the landfill constituentS are not distributed homogeneously throughouL
81011281T9' .AOOJICTNE.a:wMD
-------
-------
.. ...~;:_:..\J=c=rr:~'~c~~.~-g~~,~-\~-'~I~I1~-;----~.~.~ I
~ ~p & ~
() ~)no f" "."t Ir
';CIIU.
@
11-4
I. [GLND:
. PUAsr I (:lln"NO WI\1[R MONIlr)RINI~ W[lI.S
(8'> P"A~[ II r.lmUNO WI\1f.R IAONII(JI?INr. Wrt.lS
,GrYJ" TOPOGRArHI(. CONI OUR (ElEVATION IN rEEl MSI.)
--. -"'-"-------- ...
- .--- ---.------.--.---.. .----
.--.---..---...---------
rr __n'--rr- .
'\T----'---I{
- rr-uh-rr--'-,7------ n_-
-.-----.-..----.---..--. -
..------.--. --...-.---.. --...
""'---.-.
---cT- -----IT . ...-. ---V-I- ~-J::{ ----[{- ----'---\J--'----1{---
IGLOO 9LOCK 0
[(
11
..-----
fr - ----[1-- --IJ---Y- --- -- --_nn-!f---,}------1r-h--lf
[f
if
...._-.--_.__.... .
Ir ---. .. U
---_. -- ..--.- h_...,_-- ... --.-. .
h---l-r----mYT------- I( h-
rJ-----'---yr---iJ-'--
,
/'
,I Figure 3: Active landfill
II_--_--_n_..____---------- "--____00__..---_.-. ----...------- ------------.--- --------
r~"'" ~- . .~ ---~:;i;:~::;1 : i '-~_.,:,~,~ - -- -. ---.-- --; ;#..r;.-;;_n- ~;~:~::;~.r~::,~~:;~~n - ---J~;; hn_____- ~f:~-I~~"~AN~~~~~~----~
11 "-, ''''1/ .J A' --""WI! I ("""/ .'In "I .- . ce- '''''-7.=,.._"e,nniw." ()H. 1111811'1.1992_: _. """,---,. -- - --.. 00_-0- --,",...,.- -,...,~..,.- -,,",-=-.~7'7"":-::-_=_~
,
~
-
I
R
~
-------
- '-. '_a ........ '.,-.' -.'." '.- .." .
Therefore. the samples would not be representative of general site conditions. Funher.
the cap will effectively prohibit contact and exposure to the soil eliminating any
potential risk the soil may otherwise have presented to the public or the environment.
Also, because this is a landfill site, and to maintain integrity of the cap that will be
installed. future excavation and building construction would not be allowed.
Ground water was measured at a depths ranging from 152 to 161 feet below the ground
surface (elevations ranging from 487 to 502 feet MSL), and was determined to flow
towards the north. It was also determined that the local irrigation systems do not have
an affect on ground water flow directions at the ALOU. Several contaminant compounds
were deteCted at trace concenaations. but the source of these compounds could not
conclusively be deteimined. Analytical results are presented in Table 1.
The fIrst fIeld investigation repon was completed in 1988. The conclusions of that report
are summarized as follows:
All four ground water monitoring wells contain elevated concentrations of
nitrate/niaite; and three wells contained selenium at concentrations exceeding
drinking water standards.
.
Trace concentrations of RDX and cyanide were deteCted in tWo monitoring wells;
MW-33 (the upgradient well) and MW-35. Teayl was deteCted at traee
concentrations in MW-35. The fact that the contaminants were deteCted both up and
downgradient indicates they may be coming from another source.
.
Cyanide was detected at trace concentrations in MW-33a and MW-35.
Several heavy metals were detected at concentrations slightly elevated above
background. but below drinking water standards.
.
Two ground water monitoring wells. MW-33 and MW-35 were found to contain
unknown semi-volatile compounds.
.
The ground water is believed to be under confined conditions indicating that if the
landfill did release contaminantS to the subsurface. they would be prevented from
reaching the ground water. This conclusion was based on the fact that ground warer
elevations were observed to increase after well installation, indicating that the
aquifer was under pressure.
The active landfill does not appear to present a significant source of contaminantS
to ground water. The traee contaminant concentrations detected at the active landfill
arc believed to be coming from other sources within the UMDA or from off-sire
farming operations.
To further define the source and extent of the nitrate/nitrite and selenium. and to verify
the presence of trace concentrations of explosives. supplemental ground water
investigation activities were recommended.
87C8211 'TE'.ROOJlCTIVE.a:wM13
-------
. . "'"
TABLE 1
Contaminants Detected In Ground Water In the Active landfill Area
Phase Iinvestfgatfon
(concentrations In ugIL)
.. SamDle Location and Date
MW--33a MW-34 MW-35 MW.:J6 TP-ALb F8-ALc
Contaminant 6/18/88 6/19/88 6/19/88 6/18188 6119/88 6/20/88
Explosives None NlA None
RDX 1.34 <0.63 2.06
Tet~1 <0.66 2.22 <0.66
NitratelN itrite 14.300 12.600 12.600 12.600 N/A <5.000
Cyanide 22.1 <16.0 20.5 <16.0 N/A <16.0
VOAs None None None None None
Chlorofonn 16.0
SNAs None None NlA None
UNK595 N/D 2.10
UNK597 N/D 13.0
UNKEi02 N/D 6.0
UNKEi05 N/D 123
UNKEi08 5.00 N/D
UNK611 N/D 202
UNK623 N/D 23.0
TOC 2.800 2.100 4.700 4.900 NlA 2.400
Metals N/A
Ag <0.19 <:0.19 <0.19 <0.19 <0.19
As <5.00 <5.00 <5.00 <5.00 <5.00
Be <0.103 <:0.103 <0.103 <0.103 <0.103
Cd <5.10 <5.10 <5.10 <5.10 <5.10
Cr <37.5 <37.5 <37.5 <37.5 <37.5
Cu 7.72 5.47 10.5 12.8 3.86
Hg <0.17 <:0.17 <0.17 <0.17 <0.17
Ni <9.6 <9.6 38.8 12.1 10.8
Pb 6.77 4.95 6.37 5.46 5.46
Sb <5.00 <5.00 <5.00 <5.00 <5.00
Se <5.00 32.3 24.5 14.3 <5.00
TI <5.00 <5.00 <5.00 <5.00 <5.00
Zn 1.200 2.110 2.100 1.200 1.600
Notes:
None = Group of anaJyt~ not detected above detection limits a = Upgradient well
N/A ;;. Analyte or group of analytes not analyzed b = Trip blank
N/D = Analyte not detected above detection limit c = Field (rinse) blank
Source: Final Remecflallnvestigation Report. August, 1992 UNK = Unknown
---.-
-------
"'''' ..... .-.... ,"
The second phase of investigation included the installation of six additional ground water
monitoring wells. These wells were placed to better define background ground water
quality. and to assist in detennining if the elevated concentrations of compounds were
due to the landfill or regional background conditions (Figure 3). All of the ground water
monitoring wells were installed into the alluvial aquifer.
..
The six new wells and the four existing wells were sampled during two additional
sampling eventS. Depths to ground water ranged from 140 to 152 feet below grade, aDd
elevations ranged from 491 to 520 feet MSL. The additional data pointS revealed thal
ground water was flowing to the west-northwesL The second investigation also
determined that ground water does not exist under confined conditions in the alluvial
aquifer under investigation.
A second and third round of ground water sampling activities was performed at aU 10
. wells. Analyses performed on the ground water samples include: Target Analyte LiSt
(TAL) inorganics (which includes metals, nonmetallic elementS and cyanide), volatile
organic compounds, semi-volatile organic compounds. pesticides. polychlorinated-
biphenyls (PCBs), explosives and nitrate/nitrite. Analytical resultS from the second and
third sampling event are presented in Table 2. Trace concentrations of several
contaminant compounds were detected. However. cyanide, RDX. and tetryl were not
detected during the second and third event, indicating that these compounds may not be
present. In fact, no explosives were deteCted during the second or third sampling evenL
Ten of the wells were found to contain low concentrations of unknown semi-volariJe
compounds/tentatively identified compounds (TICs). It was detennined that some small
portion of the TICs deteCted may be attributed to the landfilL The results confmn thal
nitrate/nitrite, vanadium, and selenium are elevated. The resultS also confirm that the
down gradient concentrations of these compounds are consistent with the upgradient
concentrations indicating that the landfill is not the source of these compounds. An
overall summary and interpretation of the data from all three sampling eventS is
presented in Table 3.
The Army did not anticipate finding significant contamination at this site. The majority
of materials disposed at the site were non-hazardous and/or can be classified as
household refuse. This, in conjunction with the fact that there is very little precipitation
at the site, has apparently resulted in negligible negative impact on the local
environmenL
In general, resultS of the supplemental investigation found that the slightly elevated
concentrations of several compounds were in fact the result of background ground water
quality. The State is cmrently conducting a study of local ground water quality,
specifically with respect to nitrate/nitrite, vanadium, and arsenic which appear to be
elevated throughout the area. However, it wasdetennined during the RI that the landfill
may be contributing a small amount of nitrate/nitrite to the ground water. but that the
off-post contribution of nitrate/nitrite from agricultural activities is thought to be much
more significant than the amount of nitrate/nitrite coming from the landfill. The RI also
determined that the low concentrations of TICs detected in the ground water may be due
to the landfill, and are neither significant nor a matter of concern.
87Q1211'm' .AOO.ACTNE.c:w2IIIID
-------
. .
'.
TABLE 2
Ground Water Analytical Results
Phase 2 Investlgallon
Active undllil Page 1 01 8
GW Data. 10m91
MAPID 11.1 11-1 11.2 11.2 11-2 11-3 11-3
SITE 10 G11AOO1 G118001 G11AOO2 G11AOO2D G118002 G11AOO3 G118003
FIELD ID MWK7"122 MWK7"123, MWK7"124 UMWK7"88 UMWK7"89 UMWK7"90 UMWK7"94
S.DATE 22-Oct.90 2:hIan-91 04-Nov-90 O4-Nov-90 18-Feb-91 21.Oct-90 21-Jan-91
DEPTH 162.0 162.0 137.0 137.0 137.0 116.0 116.0
MATRIX CGW CGW CGW CGW CGW caw CGW COMPARISON
UNITS CRt.. UGL UGL UGL UGL UGL UOL UOL CRfTERIA
TAL Inoraanlcs
ANTIMJNY (GFAA) 3.03 LT 3.03 3.3 L T 3.03 L T 3.03 LT 3.03 LT 3.03 LT 3.03 5
ARSENIC 0.25 LT 2.54 2.99 15.1 15 20.4 5.97 6.18 50
BARIUM 5 91.6 102 58.5 70.8 46.8 168 156 1000
CALCIUM 500 43000 42000 69815 63655 70842 46000 42000 NSA
CHROMIUM 6 13.8 13.3 15.9 18.2 25.5 LT 6.02 LT 6.02 100
COPPER 8.1 LT 8.09 L T 8.09 L T 8.09 L T 8.09 56.1 LT 8.09 LT 8.09 1300
CYANIDE 2.5 IT 2.5 IT 2.5 IT 2.5 IT 2.5 IT 2.5 IT 2.5 l T 2.5 G NSA
IRON 42.7. IT 38.8 L T 38.8 136 L T 38.8 L T 38.8 LT 38.8 LT 38.8 300
LEAD (GFAA) 1.26 LT 1.26 LT 1.26 1.95 1.41 L T 1.26 LT 1.26 LT 1.26 15
MAGNESIUM 500 29000 28000 54656 51619 58704 27000 23000 NSA
MANGANESE 2.75 30.6 3.54 9.19 10.8 LT 2.75 4.13 LT 2.75 50
POTASSIUM 375 2000 2660 5641 5698 4052 3200 3520 NSA
SELENIUM 3.02 30.9 (58.3) (71.1) (72.~) 163.9) LT 3.02 3.41 50
SODIUM 500 41400 34600 47799 45388 43501 20500 17400 100000
VANADIUM (GFAA) 3.82 (40) (49.1) (34.7) (36.4) (44.7) (58) (67.4) 20
ZINC 2U LT 21.1 LT 21.1 LT 21.1 LT 21.1 75 LT 21.1 LT 21.1 .. 5000
EXDloslv..
ROX 2.11 L T 2.11 L T 2.11 LT 2.11 LT 2.11 L T 2.11 12.3U 5.32U 10
TElAY\.. 0.556 L T 0.556 L T 0.556 L T 0.556 L T 0.556 L T 0.556 L T 0.~6 l T 0.556 52.5
TCL VOAe
CHLOROFORM 0.5 LT 0.5 LT 0.5 LT 0.5 2.05 LT 0.5 LT 0.5 LT 0.5 100
TOLUENE 0.5 LT 0.5 LT 0.5 LT 0.5 I.T 0.5 LT 0.5 LT 0.5 LT 0.5 1000
TRICHLOROFlUOAOMETHANE 1.4 IT 1.4 7.21 LT 1.4 U 1.4 U 1.4 LT 1.4 LT 1.4 T 10000
VOA 11C.
TRICHLOAOTRIFLUOROETHANE NA NO 305 NO NO NO NO NO NSA
TCL BNA.
2.4-DNT 4.5 LT 4.5 LT 4.5 LT 4.5 LT 4.5 LT 4.5 LT 45 LT 4.5 0.18
2.6-DNT 0.79 L T 0.79 L T 0.79 II 0.79 U 0:'9 II 0.79 II OJ!! l T 0.79 000"
BIS(2-ElHYlHEXYL) PHlHALA TE 4.8 LT 4.8 LT 4.8 L.T 4.8 LT 4.8 U 4.8 IT 48 LT 4'.8 4
-------
TABLE 2 (cont.)
Ground Water Analytical Results
Phase 21nvestlgallon
Active landfill Page 2 01 8
GW Data. 100/91
MAPID 11-1 11-1 11.2 11-2 11.2 11-3 11-3
SITE 10 G11AOO1 G118001 G11AOO2 G11AOO2D G11BOO2 G11A003 G11 BOO3
FIELD 10 MWKr122 MWK7*123 MWK7"124 UMWK7"88 UMWKr89 UMWK7*90 UMWK7"94
S. DATE 22.Oct.90 23-.18n.91 04-Nov.90 04-Nov.90 18-FeI).91 21.Oct.90 21-.1an.91
DEPTH 162.0 162.0 137.0 137.0 137.0 116.0 116.0
MATRIX CGW caw CGW CGW CGW CGW CGW CCJAFARISON
UNITS CRLs UGL UGL UGL UGL UGL UGL UGL CRITERIA
BNA TiCs
CAPROLACTAM NA NO NO NO NO (300 SJ NO NO 17.5
CYCLOPENTANONE NA NO NO NO NO 8S NO NO NSA
HEXACOSANE NA NO NO NO NO NO NO NO NSA
PENTAcoSANE NA NO NO NO NO NO NO NO NSA
TETRACOSANE NA NO NO NO NO NO NO NO NSA
TOTAL UNKNOWN TICs NA (2) 13 NO NO NO (2) 13 NO NO NSA
Other Inoraanlcs
NITRATElNlffilTE 10 (16000J (15000) (15OooJ (15000) (17000J (16000J (15000J 10000
CirotrJ n P.AI'.,iW.' 1,'.'\1..'
, .
-------
. .
'.
TABLE 2 (conl)
Ground Water Analytical Results
Phase 2 Investigation
Active landllli Page 3 01 8
GW Data -10m91
UAPID 11-4 11-4 11.4 11-5 11-5 1Hi 1Hi
SITE ID Gll AOO4 Gll BOO4 GllB004D G11AOO5 G11BOO5 GllAOO6 G11B006
AELD ID UWK78122 UWKrl23 UWKr124 UUWKr88 UMWKr89 UMWKr90 UUWKr94
S.DATE :JO.Oct-90 14-Feb-91 14-Feb-91 22-Oct.90 18-Feb-91 22.Oct.90 2:h1an-91
DEPTH 132.0. 132.0 132.0 158.0 158.0 159.0 157.0
MAmlX caw eGW eGW eGW eGW eGW eGW COMPARISON
UNITS CRt.. UGL UGL UGL UGl UGL UOL UGL CRITERIA
TAL Inoraanlea
ANTIMONY (GFAA) 3.03 IT 3.03 LT 3.03 4.02 IT 3.03 3.21 LT 3.03 LT 3.03 5
ARSENIC 0.25 LT2.S4 3.2 3.09 5.01 4.69 LT 2.54 5.44 50
BARIUM 5 135 135 135 71.9 74.6 70.1 72.3 1000
CAlCIUM 500 26694 24641 24641 29000 28747 40000 32000 NSA
CHROMIUM 6 IT 6.02 LT 6.02 LT 6.02 6.34 6.76 LT 6.02 LT 6.02 100
COPPER 8. I LT 9.09 LT 9.09 I.T 9.09 IT 8.09 22.8 LT 8.09 IT 9.09 1300
CYANIDE 2.5 IT 2.5 IT 2.5 LT 2.5 LT 2.5 LT 2.5 LT 2.5 IT 2.5 NSA
IRON 42.7 LT 38.9 IT 39.8 LT 38.6 LT 38.8 IT 36.8 LT 39.8 LT 38.8 300
LEAD (GFAA) 1.26 LT 1.26 IT 1.26 5.21 IT 1.26 IT 1.26 LT 1.26 LT 1.26 15
MAGNESIUM 500 12753 12348 11943 19000 22267 29000 25000 NSA
MANGANESE 2.75 11.2 IT 2.75 L1 2.75 13.8 4.29 40.6 16.1 50
POTASSIUM 375 4030 3699 3337 3360 3610 4630 4180 NSA
SELENIUM 3.02 IT 3.02 IT 3.02 LT 3.02 3.41 4.15 4.26 4.9 50
SODIUM 500 16038 14361 13836 41300 44549 26500 21400 100000
VANADIUM (GFAA) 3.82 (68.9) (74.3) (74.8) (58.6) (69.5) 17.3 (49) 20
ZINC 21. I IT 21.1 IT 21.1 LT 21.1 IT 21.1 28.7 IT 21.1 LT 21.1 5000
EXDloslves
RDX 2.11 IT 2.11 IT 2.11 LT 2.11 IT 2.11 LT 2.11 3.84U 4.72U 10
T'E'THYl 0.556 l T 0.556 l T 0.556 L T 0.556 l T 0.556 L T 0.556 L T 0.556 LT 0.556 52.5
TeL VOA.
CHLOROFORM 0.5 IT 0.5 IT 0.5 LT 0.5 LT 0.5 IT 0.5 LT 0.5 IT 0.5 100
TOlUENE .0.5 IT 0.5 IT 0.5 IT 0.5 LT 0.5 2.35 LT 0.5 0.892 1000
TRICHLOOOFlUOROMETHANE 1.4 LT 1.4 IT 1.4 IT 1.4 IT 1.4 LT 1.4 IT 1.4 6.71 10000
VOA 11Ca
TRICHLOAOTRIFLUOROETHANE NA NO NO NO NO NO NO 30S NSA
TCL BNA.
2.4-DNT 4.5 LT 4.5 IT 4.5 LT 4.5 IT 4.5 LT 4.5 LT 4.5 LT 4.5 0.18
2.6-DNT 0.79 l1' 0.79 IT 0.79' IT 0.79 LT 0.79 1.1 0.79 1.1 0.7!> I.T 0.79 o.on]
BIS(2.ETHVLHEXVl) PHTHALATE 4.8 LT 4.8 LT 4.8 LT 4.U tT 4.8 LT 4.8 1101 LT 4.8 4
-------
TABLE 2 (cont.)
Ground Water Analytical Resuhs
Phase 21nvestlgallon
Acllve landfill Page 4 of 8
GW Data - 1017/91
MAPID 11-4 11-4 11.4 11.5 11.5 11-6 11-6
SITEID G 11 AOO4 G11B004 G11B004D G11AOO5 G11B005 G11 AOO6 G11B006
FIELD ID MWK1"122 MWK1"123 MWK1"124 UMWK1"88 UMWK1"89 UMWK1"90 UMWK1"94
S. DATE 3O-Oct.90 14.Feb-91 14-Feb-91 22.Oct.90 18-Feb-91 22.Oct.90 23-.1an.91
DEPTH 132.0 132.0 132.0 158.0 158.0 159.0 157.0
MATRIX CGW CGW CGW CGW CGW CGW CGW CXJAFARISON
UNITS alL. UGL UGL UGl UGl UGl UGL UGL CRfTERLA
BNA TiCs
CAPROlACTAM NA NO NO NO (2081 108 NO NO 17.5
CYCLOPENTANONE NA NO NO NO NO NO NO NO NSA
HEXACOSANE NA NO 305 NO NO NO NO NO NSA
PENTACOSANE NA NO 305 NO NO NO NO ND NSA
TETRACOSANE NA ND 305 ND NO NO NO NO NSA
TOTAl UNKNOWN TICs NA ND (7) 123 ND (3) 25 (6) 43 (3)238 (5)32 NSA
Other InoraanlcS
NITRATEINITRITE 10 5000 4900 4700 10000 (11000) 10000 6800 10000
tilUk' Il t'.N'~'\IW" I~"!
. .
-------
" .
".
TABLE 2 (oonl)
Ground Waler Analytical Resuhs
Pha88 2 Invesllgalion
Active landfill Page 5 01 8
GW Dala . 10n/91
MAPID MW-33 MW-33 MW-34 MW-34 . MW-35 MW-35 MW-36
SITE ID G11A033 011 B033 G11A034 G11B034 G11A035 G11B035 G11A036
AELD ID MWK7"122 MWK7"123 MWK7"124 UMWK7'88 UMWK7"89 UMWKr90 UMWKr94
S. DATE 30-0ct-90 17.Feb-91 22-0cI-90 22.Jan-91 22-Oct-90 22.Jan-81 3O-Oct-90
DEPTH 161.0 161.0 165.0 165.0 161.0 161.0 161.0
MATRIX COW CGW CGW caw CGW CGW CGW COMPARISON
UNITS CRt. UGL UGL UGl UGL UGL UGL UGL CRfTERIA
TAL Inorganlca
ANTIMONY (GFAA) 3.03 (6.16) LT 3.03 4.91 (5.62) (7.23) I..T 3.03 LT 3.03 5
ARSENIC 0.25 5.97 4.05 5.01 5.65 8 8.32 6.72 50
BARIUM 5 54.6 52 56.9 57.4 28.8 35 28.2 1000
CAlCIUM 500 33881 29774 52000 54000 49000 48000 35934 NSA
CHROMIUM 6 8.53 8.45 16.9 18.6 15.2 26.6 10.2 100
COPPER 8.1 15.8 I..T 8.09 LT 8.09 LT 8.09 I..T 8.09 I..T 8.09 I..T 8.09 1300
CYANIDE 2.5 LT 2.5 I..T 2.5 LT 2.5 I..T 2.5 I..T 2.5 I..T 2.5 IT 2.5 NSA
IRON 42.7 IT 38.8 LT 38.8 IT 38.8 LT 38.8 I..T 38.8 I..T 38.8 IT 38.8 300
lEAD (GFAA) 1.26 I..T 1.26 4.12 LT 1.26 3.58 LT 1.26 I..T 1.26 IT 1.26 15
MAGNESIUM 500 17308 15688 43000 40000 33000 34000 28340 NSA
MANGANESE 2.75 5.36 8.24 IT 2.75 IT 2.75 LT 2.75 LT 2.75 IT 2.75 50
POTASSIUM 375 4347 4745 815 1710 2260 1130 3235 NSA
SELENIUM 3.02 3.62 3.51 33.1 (69.1) 14.1 24.1 22.2 50
SOOIJM 500 49a>7 41195 31600 27800 36400 34800 33333 100000
VANADIUM (GFAA) 3.82 (51. 7) (46.4) (53.2) (56.2) (49) (61.7) (58.5) 20
ZINC 21.1 IT 21.1 l T 21.1 IT 21.1 LT 21.1 IT 21.1 LT 21.1 IT 21.1 5000
Explosive.
RDX 2." 21 U l T 2.11 IT 2.11 IT 2.11 9.98U 16.8U 14U 10
TElRYL 0.556 l T 0.556 l T 0.556 l T 0.556 l T 0.556 l T 0.556 l T 0.556 l T 0.556 52.5
TCL VOA.
CHLOROFORM 0.5 IT 0.5 LT 0.5 LT 0.5 LT 0.5 I..T 0.5 I..T 0.5 IT 0.5 100
TOlUENE 0.5 IT 0.5 2.35 LT 0.5 1.08 IT 0.5 1.37 I..T 0.5 1000
TRlCHlOROFllJOAOMElHANE 1.4 IT 1.4 IT 1.4 IT 1.4. 8.02 I..T 1.4 LT 1.4 LT 1.4 T 10000
YOA TICs
TRICHLOROTRIFLUOROETHANE NA NO NO NO 30ST NO NO NO NSA
TCL BNAa
2.4-DNT 4.5 IT 4.5 LT 4.5 (7.861 LT .4.5 I..T 4.5 IT 4.5 I..T 4.5 0.18
2.6-DNT 0.79 I.T 0.79 l T 0.79 (0.917] l T 0.79 l T 0.79 I.T 0.79 I.T 0.79 0.007
BIS(2.ETUVUIEXYl) PInHALATE 4.8 IT 4.8 19.091 110.21 IT 4.0 LT 4.8 "I 4.0 l 1 4.8 4
-------
TABLE 2 (cont.)
Ground Water Analytical Resuhs
Phase 2 Investigation
Active landllll Page 6 01 8
GW Data -10"'91
MAPID MW-33 MW-33 MW-34 MW-34 MW-35 MW-35 MW-36
SITEID G11A033 G118033 G11A034 G 11 poo.4 G11A035 G118035 G11 A036
FIELD ID MWK7"122 MWK7"123 MWK7"124 UMWK7"88 UMWK7"89 UMWK7"90 UMWK7"94
S. DATE 3O-Oct-90 17-Feb-91 22-Oct-90 22-Jan-91 22-Qct-90 22-Jan-91 3O-Oct-90
DEPTH 161.0 161.0 165.0 165.0 161.0 161.0 161.0
MATRIX CGW CGW CGW CGW CGW CGW CGW COMPARISON
UNITS alL.s UGL UGL UGL UGL UGL UGL UGL CRfTERIA
BNA TICS
CAPROLACTAM NA NO NO NO (305) NO NO NO 17.5
CYCLOPENTANONE NA NO NO NO NO NO NO NO NSA
HEXACOSANE NA NO NO NO NO NO NO NO NSA
PENTACOSANE NA NO NO NO NO NO NO NO NSA
TETRACOSANE NA NO NO NO NO NO NO NO NSA
TOTAL UNKNOWN TICs NA NO (1) 4 (5) 153 (1) 93 (2) 30 NO NO NSA
Other Inoraanlcs
NITRATEJNITRITE 10 (16000) (16000) (13000) (12000) (16000) (15000) (13000) 10000
tilUW IU'iN'.,\i'h1, '~'~f.."
. .
-------
. .
'.
TABLE 2 (conI.)
Ground Wal8r Analytical Results
Pha88 2 Investigation
Active landfill Page 7 of 8
GW Data .10",91
MAPID MW.36 MW.36
SITE ID G11B036 G11 B036D
FIELD ID MWK7"122 MWK7"123
S. DATE 17-~b-91 17.~b-91
DEPTH 161.0 161.0
MATRIX CGW CGW COMPARJSON
UNITS CRt.. UGL UGL CRITERIA
TAL Inora.nlea
ANTIWNY (GFAA) 3.03 LT 3.03 LT 3.03 5
ARSENIC 0.25 4.48 5.22 50
BARIUM 5 20.1 21.4 1000
CALCIUM 500 37988 34908 NSA
CHROMIUM 6 LT 6.02 LT 6.02 100
COPPER 8.1 LT 8.09 LT 8.09 1300
CYANIDE 2.5 LT 2.5 LT 2.5 NSA
IRON 42.7 LT 38.8 LT 38.8 300
LEAD (GFAA) 1.26 LT 1.26 9.54 IS
MAGNESIUM 500 29352 26316 . NSA
MANGANESE 2.75 5.08 5.85 50
POTASSIUM 375 3519 3451 NSA
SELENIUM 3.02 20.8 21.3 50
SOOUM 500 29979 30503 100000
VANADIUM (GFAA) 3.82 (51.4) (50.7) 20
ZINC 21. I 52.3 56.5 5000
EXDloalv..
ROX 2.11 l T 2.11 l T 2.11 10
TETRYl 0.556 l T 0.556 L T 0.556 52.5
TCl VOAa
CHLOROFORM 0.5 IT 0.5 IT 0.5 100
TOlUENE 0.5 4.61 6.18 1000
TRICHlOROflUOAOMElliANE 1.4 LT 1.4 IT 1.4 10000
VOA l1Cs
TRICHlOAOffilFlUOROElliANE NA NO NO NSA
TCL DNA.
2,4-DNT 4.fi IT 4.!) IT 4.fj 0.10
2.6-DNT 0.79 LT 0.79 LT 0.79 0.007
-------
TABLE 2 (cont.)
Ground Water Analytical Results
Phase 2 Investigation
Active landfill Page 8 018
GW Data - 10n/91
MAPID MW-36 MW-36
SITEID G11B036 G11 B036D
FIELD ID MWKr122 MWKr123
S. DATE 17-Feb-91 17-Feb-91
DEPTH 161.0 161.0
MAmlX CGW CGW COMPARISON
UNITS CRLs UGl UGL mrrERIA
BNA TiCs
CAPROlACTAM NA NO NO 17.5
CYClOPENTANONE NA 20S 20S NSA
HEXACOSANE NA NO 20S NSA
PENTACOSANE NA NO NO NSA
TETRACOSANE NA NO 20S NSA
TOTAL UNKNOWN TICs NA (4) 21 (6)68 NSA
Other InorGanlcs
NITRATEINITRITE 10 (13000J (13000J 10000
GT .. Greater Than
LT. Less Than
NA .. Not Available
NO .. Not Detected
NSA.. No Standard Available
NT .. Not Tested
S .. Resuhs Based on Internal Standards
TICs", Corf1)OUnds for Which No Standard for IdentHicalion Exists
U .. Unconfirmed
( J .. Detected concentration exceeds oorrparison criterion
Source: Final Remedial Investigation Report, August, 1992
61a>1I1:1'IAI'~v.\s .'"
. .
-------
... ......
...' . ..-. .. ...
TABLE 3
Summary and Interpretation of Ground Water Analytical Data
.'
ACT1VE LANDFILL
Compounds detected only once and/or at trace concentrations:
Cyanide
Explosives:
RDX
Tetryl
Compounds tentatively Identified, but not confirmed present at trace concentrations:
2.4-DNT
2.6-DNT
Compounds detected that are sampling or laboratory artifacts:
Bis(2-EthylhexJy)Phthalate
BNA TICs:
Caprolactam
Cydopentanone
Hexacosane
Pentacosane
Tetracosane
Volatile Organics:
Chloroform
T oulene
Trichlorofloromethane
T richlorofluoroethane
Compounds detected that are thought to be attributed to the landfill:
Nitrate/Nitrite
Several unidentified semi-volatile organic compounds.
Compounds detected at elevated concentrations that were found to be elevated regionally:
Arsenic
Nitrate/Nitrite
Selenium
Vanadium
. The unidentified semi-votable compounds are not listed as EP A Priority Pollutants
Source: Final Remedial Investigation Report. August, 1992
ClaRT'EJlrASuOUlll.'-
87082111 TEP.AOOJlCTNE.a:nMD
-------
Since there are no water supply wells at the ALOU. there are no current pathways that
would result in human e~posure to the low concentrations of contaminants in the ground
water. In addition, the landfill is located within an area that is fenced with limited
. access, eliminating any potential exposure to the disposed material.
'.
2.6 Summary of Site Risks
This section summarizes the human health risks and environmental impacts associated
with exposure to site contaminants and provides potential remedial action criteria.
2.6.1 Human Health Risks
A baseline risk assessment was conducted during the 1992 RI to determine the potential
risk the site would pose to human health and the environment if no clean-up activities
were performed.. A risk assessme.nt consists of several steps. The fIrst step is an exposure
analysis where potential pathways by which someone might be exposed to a compound
are identifIed. If there are no exposure pathways. there is no risk. Second, a list of
compounds {"contaminants of concern") is developed. These are the compounds that will
be considered in the risk calculations. They are chosen based on their concentration and
potential toxiciry. For this risk assessment. the contaminants were selected to be
"contaminants of concern" if they were found to be above background or present at
elevated concentrations. Compounds found to be elevated. due to naturally occurring
conditions. with the exception of nitrate/nitrite, were also included to produce a more
conservative risk estimate. Once the contaminants of concern are identified. a toxicity
assessment is performed. Assumptions and data from toxicological studies on humans
and animals are used to quantify the potential toxicity or potency of a particular
compound. In addition, the calculations are perfonned to proteCt the most sensitive
population and contain conservative assumptions on, for example. duration and
magnitude of exposure. As such, there is uncenainry associated with risk assessmentS.
They should not be considered a predictive tool. but an instrument for detennining
relative priorities for clean-up of contaminated sites.
All of this infonnation is combined to j)erfonn the human health risk evaluation, where
the potential risk to human health posed by the site is quantified. A hazard index is
generated for potential noncarcinogenic effects, and a cancer risk level is generated for
potential carcinogenic contaminants. In general. a hazard index of1ess than one indicates
that even the most sensitive population is not likely to experience adverse health effects.
The cancer risk level is expressed as a probabiliry and indicates the additional chance
that an individual will develop cancer over a lifetime of exposure. EPA's acceptable risk
range for cancer is 1 x 10-4 to I x 10-6; or one additional chance in ten thousand to one
additional chance in one million that a person will contract cancer if they arc exposed
to a site for 30 years.
2.6.1.1 Exposure Analysis. The populations at risk of exposure to this site we~
identifIed by considering both current and future use scenarios. A detailed risk analysis
of the current land use scenario was not evaluated for several reasons:
1J?Q12111 YEP .AOOACTIIIE.a:r2M3
-------
Access to the landfill is limited to UMDA personnel. Because the landfill is active,
only those individuals who operate the landfill are expected to have the most
significant exposure to the ALOU;
.'
The landfill receives garbage only once a week and that material is covered. funher
limiting the potential for exposure;
The landf1l1 will cease receipt of municipal waste in approximately one year
(October 1993). and receipt of all waste in 1994, and then proceed to closure,
effectively removing any potential for exposure to the materials at the landfill; and
.
No water supply wells presently exist at the landfill, therefore there is no current
potential for exposure to ground water.
In summary, risks associated with cwrent land use were not evaluated because the
potential for, and duration of exposure was expected to be small. In addition. an
evaluation of risk associated with residential land use of this site will generate the most
conservative risk estimate. If the risk assessment showed residential use of the site to be
acceptable, that indicates all other potential scenarios. including the current land use, is
also acceptable. Therefore, the population hypothetically exposed to the contaminantS
was site residentS.
Exposure to contaminated soil was detennined not to be of concern and was not
addressed in the human health risk assessment. Currently, the site is secured and only
accessible to UMDA personnel. UMDA personnel are present at the landfill only once
weekly during refuse disposal. The personnel present are in vehicles/equipment
associated v.ith landfill operations and remain in those vehicles while they are at the
landfill. The active disposal area is covered with clean fill weekly after disposal
activities are complete. Therefore, there are no significant current exposures to soil at
the ALOU. The landfill is scheduled to close and be capped in accordance with state and
federal regulations. eliminating any potential future exposure pathways. In addition.
because the site has been operated as a landfill, any post-closure activities that would
degrade the integrity of the cap will not be penni~ ensuring that there will be low or
limited potential for future exposure.
The potential risks associated with a future residential land use were analyzed in detail.
The exposure routes that were evaluated include:
.
Drinking ground water from beneath the landfill;
.
Showering with ground water from beneath the landfill; and
.
Eating crops that were irrigated with ground water from beneath the landfill.
2.6.1.2 Contaminant ldentmcstlon. Although tentatively identified semi-volatile
organic compounds and niaate/nitrite compounds were the only contaminants dercrmined
to be associated with the landfill in the RI re~ they were not included in the
compounds identified for the Risk Assessment. This is because the semi-volatile
compounds were only tentatively identified, and their detection is generally consi~red
~1TB' ..AOO.ACTI\IE.a:v.!111113
-------
,_. ,..". "."- ., ~_.- .'-
.. .' ..' ~,... - ... ,...n .' ... ". ".. . . .' ..
questionable. Nitrate/nitrite was discounted because the conttibution from off-post
sources related to agricultural activities are much more significant so the concentrations
detected at the landfill were detennined to be background. The compounds that were
evaluated in the risk assessment, and the concentrations of those chemicals are listed in
Table 4. These compounds, although detennined not to be associated with the landfill,
and not to be of concern, were carried through the risk assessment to generate a ~
conservative risk estimate.
'.
Health effects criteria for the compounds of concern are listed in Table 5. Included are
the Cancer Potency Factor and Reference Dose for the appropriate compounds. Cancer
Potency FactOrs (CPFs) have been developed by EPA's Carcinogenic Assessment Group
for estimating excess lifetime cancer risks associated with exposure to potentially
carcinogenic chemicals. CPFs. which are expressed in unitS of (mg/kg-day), are
multiplied by the estimated intake of a potential carcinogen. in mg/kg-day, to provide
an upper-bound estimate of the excess lifetime cancer risk associated with exposure at
that intake level. The term "upper bound" reflects the conservative estimate of the risks
calculated from the CPF. Use of this approach makes underestimation of the actual
cancer risk highly unlik~ly. Cancer Potency Factors are derived from the resultS of
human epidemiological studies or chronic animal bioassays to which animal-te-human
extrapolation and uncertainty factOrS have been applied.
Reference Doses (RIDs) have been developed by EPA for indicating the potential for
adverse health effectS from exposure to chemicals exhibiting :1oncarcinogenic effectS.
RIDs, which are expressed in unitS of mg/kg-day. are estimarcs of lifetime daily
exposure levels for humans. including sensitive individuals. Estimated intakes of
chemicals from environmental media (e.g.. the amount of a chemical ingested from
contaminated drinking water) can be compared to the RID. RIDs are derived from
human epidemiological studies or animal stUdies to which uncertainty factors have been
applied (e.g., to account for"the use of animal data to predict effectS on humans). These
uncertainty factors help ensure that the RIDs will not underestimate the potential for
adverse noncarcinogenic effectS to occur.
As indicated above. there is a significant level of uncertainty associated with risk
assessmentS. However. the infonnation that is used in a risk assessment is generally
biased to ensure that a conservative. overestimation of risk will be generated. rather than
an underestimation.
2.6.1.3 Risk Evaluation. Table 6 presentS the risk factOr and hazard index values
associated with each exposure pathway. broken down by compound. Tables 7 through 9
present the risk factOr and hazard index estimates by compound for each pathway.
ResultS of the risk evaluation show that ground water ingestion poses the largest
potential risk at this site. Arsenic. a naturally occurring element, is primarily responsible
for the risk. However. even with the inclusion of arsenic in the evaluation. the cancer
risk is within the acceptable risk range established by the NCP (1 x 10-4 - 1 x 1O~. The
non-
-------
" .
".
TABLE 4
Occurrence and Dlstrtbution 01 Compounds Evaluated In the Active landfIll RiSk Assessment
Frequency Percent Range of Upper 95 Percent
of Positive Range of Sample Detected Confidence location of Compartson Crtterta Number 01
COMPOUND UNIT Detection Detections Detection limits Concentrations limit (a) Max. Cone. Conc. Type Exceedance
TAL Inorganlcs
ANTIMONY UGL 6/20 30 3 -3.03 3.21 - 7.23 3.05 MW-35 1 Bkgj 6
ARSENIC UGL 14/20 70 2.54 -5 2.99 - 20.4 7.51 11-2 1 Bkgj 14
BARIUM UGL 16/16 100 DLNA 20.1 .102 67.5 11.1 59 Bk~ 6
CHROMIUM UGL 13/20 65 6.02.37.5 6.34 - 26.6 16.3 MW.35 1 Uk~ 1:.1
COPPER UGl 7/2,0 35 8.09 . 8.09 5.47 - 56.1 13.9 11-2 1 Bkgj 7
CYANIDE UGL 2/20 10 2.5.16 20.5 - 22.1 6.36 MW-33 NSA NA
LEAD UGL 7/20 35 1.26 . 1.26 1.95.6.77 2.93 MW-33 5 Bkgj 3
SelENIUM UGL 19/20 95 5.5 3.41 -71.1 34.2 11-2 1 Bkgj 19
VANADIUM UGl 16/16 100 DLNA 17.3 - 69.5 54.7 11-5 NSA NA
ZINC UGL 3/16 19 21.1-21.1 28.7 - 75 26.5 11-2 40 Bkgj 2
EXDloslves
RDX UGL 2/20 10 0.63.2.11 1.34 - 2.06 1.16 MW-36 NSA NA
TETRYl UGl 1/20 5 0.556 - 0.66 2.22 - 2.22 0.55 MW-35 NSA NA
TCl SemlvOlallles
2,4.DNT UGl 1/20 5 4.5.10 7.86 - 7.86 3.69 MW-34 NSA NA
2.6-DNT UGl 1/20 5 0.79 - 10 0.917 - 0.917 2.07 MW-34 NSA NA
(a) .. Upper 95 percent confidence Unit on the arithmetic mean. CalaJlated assuming one-half the detection level
. as the concentration lor those safT1)les in wtVch a given analyte was not detected
Bkgd ;;. The maxi/T1Jm detected concentration in bad(ground ground water
DlNA = Detecton level Not Available. The detecton levels could not be ascertained because constnuents were detected in all relevant sarrples
NA .. Not Applicable
NSA = No Standard Available tor CofT1)Ound
TAL = Target Analyte list
TCl = Target CofT1)Ound list
TIC "'. Tentitlvely Idercilied Compound
UGl .. ugi\.
Source: Final Human Heahh Basetine Risk Assessmont. August. 1992
-------
Table 5
Summary of Toxicity Criteria for the
Contaminants of Concern at the Active landfill Page 1 of 3
AlDo RIDI
~ Cmg/loalderl !!t Conlldonce CrMleal EIIKI ImglllQlderKu, UF ContNl8nce Crill..1 EtiKI
--
T Allnolgenicl
Anllmony 4.~.()4 1000 low lOI"9w." blood gluOOIe levell; NO
Mlum cOO_lttrol
Allenic 3.~.()4 3 Medium Hype,plg"*,,.lion. k'"alOO. un
...culet <:or'1'lICa'ionl
Barium 7.~.Q2 3 Medium Hypel\enllon 1.4E.04 1000 F..ocoaiol1
Ch,omum VI(e) 5.~.()3 500 low NOAH; hlghu" 1IMIIIII&1ed 6.~.Ol 1000 NuaJ ffitJW6.. ~lfoph1
Coppef 3.7E-02 low MCl 11£,02 l....
lead IUBK Model <- ..." Nftu'080aldly In ch~d'.n '0
Selenium 5E.03 3 l1'11h SelenOlI&: Mouled ""'lh. blood 10
end CNS dllordOll
Vehedlum 7.~.Q3 100 low NOAH; hlgl18ll ..... ...1oICJ NO
ZInc 2.~-O1(9 100 AnorrIe Nt>
C,enldo (II.., 2.~-Q2 100(j) Medium WelQhl 10... U",oId ,,"eell; NO
deny"nellon
e..hI..
00)( 3.~.()3 100 High NOAH; hlghu, 1"""'1 ..lOCleted NO
...h ",OII..e ir/18llVllllIon.
"e/TlOf'l. hlp8llC end ,enal
elleell
Te..,. I.OC -02 10.000 low Ulood wagullllion dellK2'. Nil
h"""ue ...10111 et" '''''''00.
61062 IlPIAIOXUAI I~"'U'
" .
-------
Table 5 (cont.)
Summary of Toxicity Criteria for the
Contaminants of Concern 8t the Active landfill
Sfo
~ II(mg/kg"'a.)
TAL '"",ganlca
AnI/many NO
Ataenlc I.75E.oo
Batlum NO
Cluonilm VIIC) NO
Coppa, NO
lNd 10
Selanlum 10
Vanadllm ND
lJnc NO
C,anlda("") NO
E.pIoelw..
2.tDNT e.8E.OI
2.&OOT e.8E-01
T8CryI NO
TV". o' Canoe,
Sf. W.lgh...,,-
IIlmg/kg"h,) 'YI'" 01 Cance, Evid.nce ClIO' ~
NO 1.1.'.1
I.4E.01 l uDJ C800t1f1 A 1.1.1.\
NO \.2.1.1
4.2£.01 Lung IUfl1OI1 II 1.2.1.1
NO II 3.3.1.1
10 DIQ8II~tt uaa; IMpuatory 02 ....1.1
'Yllttm. pe,ltoneum
10 II 1.1.1.\
ND 2.1.1.1
NO II 2.1.1.1
NO 0 1.1.1.1
NO 02 b.I.I.'
NO U2 6.1.1.1
NO e.....,
Skin canoe..
Ran" luman
H~oce.ulal
C81clnomu; III8I1Vn8IJ
Ibro8d8nomu
H~ocelul8t
CIIctnomu; IIIIImII'IIIJ
fbro8d8nomu
.
".
Page 2 of 3
-------
... .. .. .-..
Table 5 (cont.)
Summary 01 Toxicity Criteria for the
Contaminants 01 Concern at the Active landfills
.
.
Page 3 01 3
(i) -
0)-
'p) .
F"oocn0te5:
(aa) - [Malation reference doses were: calc:ulated fran reference air conccntncions (RFCs) assuming that a swndard ;Okg human Il\haIcs ~
cubic melC~ oi .ur/day (t:SEPA. 1989b). Limitations of tIIcsc assumplions arc discussed in the unccruinty seaion of the tUL
(a) . Source codes are listed below. "The 4 values shown in this colwnn arc the soun:.es for the oral RId, I.hc inhalation RID. the oral slope
faclOr. and I.hc inhalation slope factor. rcspecrively.
(I) l.:SEPA..I99Id.
(2) l.:SEPA. 1991e.
IJ) CSEPA.l99lg
(4) l.:SEPA.I99lk.
(5) 8rower. 1992
(6) l.:SEPA. 1990.
(1) Ris. 1992.
(3) R.is. 1991.
(9) Poirier. 1992.
(c). Values for heuvalenl chromium 1:'C used in this risk assessmenL
(f) . Listed value i.s for the soluble u.!u of nickel.
'1.) - Listed values arc for IUckel refinery dust and n.ickel subsulfide. respectively. Most conservative value (e.g.. nickel subsuLfidc) used in
this 8aseline RA.
Under RID/RfC Woril Group review.
A modifying faaor of 5 was used 10 rdIect tolerance 10 cyanide when adminiSICred In food.
The t:F confidence level. 3JId basis for the RfDo for aluminum an: unknoWl\. However. exposure 10 aluminum has been ass~ted
with neurological effecu.
:"ot applicable.
Acronvms:
RfDo Oral reference dose
t.:F t:nceruinty factor
RfDi [Malation reference dose
SFo Oral slope faCtOI'
S Fi [Malarion slope facor
:'01> :-00 dau
ID Insufficient data available
t.:R t:ndel'review
:-;OEl :"0 observable effect level
:-;OAEL :-00 observable adverse effect level (see Appendix B)
MCL Muimum contaminanc level
CSS Centn.l nervous sySlCm
RIC Refen:nce concencncioa (see Appendix B)
CRA VE Carcinogen Risk Assessment Verificalion Enwvor (see Appendix B)
Source: Final Human Health 8ueline Risk Assessment, August 1992
-------
"
TABLE 6
,
Multiple Pathway Potential Carcinogenic Risks
and Noncarcinogenic Hazards at the Active Landfill
Future Residential Land Use Scenario
Pathway Pathway Hazard
Number DescriDtion Risk Index
5 Ingestion 01 Ground Water 2E-04 2E+OO
7 Dermal Absorption 01 Ground Water 3E-07 6E-04
Contaminants During Showering
12 Consumption 01 Crops 6E-C6 2E-02
Total 2E-04 2E+OO
Source: Final Human Health Baseline Risk Assessment, August, 1992
671112. '!EPIARASUolT.
17'a1211TE1' JQ).ACT1\/E.2nMD
-------
TABLE 7
Potential Carcinogenic Risks and Noncarcinogenic Hazards
Due to Ingestion of Ground Water at the Active W3ndflll
Future Residential W3nd Use Scenario "
CarcInogenic
Intake Slope Factor
Analyte (mQlka/day) 1/(maIkQlday) RIsk
Antimony
Arsenic 8.82E.Q5 1.75E+OO 2E-04
Barium
Chromium
Copper
lead
Selenium
Vanadium
Zinc
Cyanide
2,4-0 NT 4.33E..Q5 6.8E..Q1 3E~
2.6-oNT 2.43E..Q5 6.8E..Q1 2E~
RDX 1.39E..Q5 1.1 E..Q1 2E..()6
T etryl
Total 2E-04
Noncarcinogenic
Intake Reference Dose Hazard
Analvte (maika/day) (maika/day) Quotient
Antimony 8.36E..Q5 4.0E~ 2E-01
Arsenic 2.06E..Q4 3.0E..Q4 7E-01
Barium 1.85E.03 7.0E..Q2 3E-02
Chromium 4.47E..Q4 5.0E.03 9E-02
Copper 3.81 E..Q4 3.7E-02 1 E-02
Lead 8.03E..Q5 .. -
Selenium 9.37E..Q4 5.0E..Q3 2E-01
Vanadium 1.50E.03 7.0E.03 2E-01
Zinc 726E..Q4 2.0E..Q1 4E-03
Cyanide 1.74E..Q4 2.0E-02 9E-03
2,4-oNT 1.01 E..Q4 2.0E.03 5E-02
2.6-DNT 5.67E-OS 1.0E.03 6E-02
RDX 323E-05 3.0E.03 1 E-02
T etryl 1.51 E..Q5 1.0E..Q2 2E-03
Total 2E+OO
. -. Not cak:ulated because CXII'Itaminant is not CU1Sidered a can:inogen or potency fadDr is not available
-- Reference dose not available
Source: Final Human Health Baseline Risk Assessmenr. August, 1992
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Table 8: Potential Carcinogenic Risks and Noncarcinogenic Hazards Due to Dermal
Absorption of Ground Water Contaminants at the Active Landfill Future
Residential Land Use Scenario
. ' Carcinogenic
Intake Slope Factor
Analyte (mg/kg/day) 1/(mg/kg/day) Risk
2AD~1 2.80E-07 6.8E-0 1 2E-07
2,6DNT 1. 32E-07 6.8£1-01 9£-08
RDX 8.24E-09 1.1£-01 9E-1.0
T etry 1 --
-
Total 3E-07
Analyte
2,4-DNT
2.6-DNT
RDX
Tetryl
Total
Noncarcinogenic
Intake
(mgJkg/day)
6.53E-07
3.09E-07
1.92E-08
1.28E-08
Reference Dose
(mglkg/day)
2.0E-03
1.0£-03
3.0E-03
1.0£-02
Hazard
Ouotlent
3E-04
3E-04
6E-06
1E-06
6E-04
.. --" Not calculated because conraminant is not considered a carcinogen or potency factOr is not available.
Source: Fmal Human Health Baseline Risk Assessment, August. 1992.
~119'.AOO~
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TABLE 9
Potential Carcinogenic Risks and Noncarcinogenic Hazards
Due to the Consumption of Crops at the Active landfill
Future Residential LBnd Use Scenario '
.
Carcinogenic
Intake Slope Factor
Analvte (maika/day) 1/(ma/ka/day) Risk
Antimony
Arsenic 1.41E-oB 1.75E-+OO 2E~
Barium
Chromium
Copper
Leaj
Selenium
Vanadium
Zinc
Cyanide
2.4-ONT 5.52E-06 6.8E.01 4E.{)6
2.6-0 NT 3. 13E-06 6.8E-Q1 2E-06
ROX 1.99E-06 1.1 E-Q1 2E-07
Tetry!
Total 6E-06
Noncarcinogenic
Intake Reference Dose Hazard
Analyte (mg/kg/day) (mg/kg/day) Ouotlent
Antimony xx 4.0E-04 xx
Arsenic 3.29E-oB 3.0E-04 1 E-04
Barium xx 7.0E-02 xx
Chromium 1.79E-oB 5.0E-a3 4E-<>6
Copper xx 3.7E-02 xx
Lea:i 1.61 E-oB .. "
Selenium xx 5.0E-a3 xx
Vanadium xx 7.0E-a3 xx
Zinc xx 2.0E-Q1 xx
Cyanide xx 2.0E-02 xx
2.4-ONT 1.29E-05 2.0E-a3 6E~
2,6-0 NT 7.29E-06 1.0E-a3 7E-OO
RDX 4.65E-06 3.0E-a3 2E-OO
T etryf 1.99E-06 1.0E-02 2E-04
Total 2E-Q2
. -. Not calculated because contaminat'lt is net ccnsidered a carcinogen or potency fader is not available
- Referenca dose not available
"xx. Ouantitative information on u~ake faders not available
Source: Frnal Human Health Baseline Risk Assessment, August, 1992
17'111a1 'IEJO .AOOACTN£.CD28ID
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. . ...'.. .
. .. .~ ..... . .
,
,
,
2.6.1.4 Human Health Risk Characterization Summary. In general. compounds
determined to be present at background concentrations as well as compounds atnibuted
[0 the landfill were included in the risk assessment. Future residential land use was the
scenario evaluated. This evaluation estimated the potential risk associated with drinking
and showering with water from a well installed beneath the landfill and eating crops
grown at the site over a long period of time. for both adults and children. These
assumptions were made to generate a very conservative, worst case, risk estimate. Based
upon the results of the risk assessment, it was decided that the landfill does not pose an
unacceptable risk to human health.
".'
While. sampling was nOl performed 10 verify the contentS of the active landfill,
documentation of materials disposed in the landf1l1 eJUsts. Soil sampling was not
performed since it could nOt effectively characterize the landfill which was continually
being changed by ongoing installation landfilling operations. However, this is nOl
believed to be a significant exposure pathway because the site will be closed and capped
in accordance with State solid waste landfill requirements, thus precluding any exposure
to the landfill contents. State requirements also prohibit any activities detrimental to cap
integrity, ensuring that future exposure to potential contamination in the landfill will not
occur. In addition, this usage restriction, and notification of the site's past use as a
landfill, must be added to the deed for this propeny.
2.6.2 environmental Risks
Preliminary results of the assessment indicate that the most contaminated sites at UMDA
are causing only limited negative impact on the local ecological environment. The
ecological risk assessment was performed for UMDA to detennine the potential for the
site to negatively affect site animal or vegetative populations. This assessmenl did not
specifically address the ALOU, but focused on the potential effects associated with the
most seriously contaminated sites at UMDA. It was assumed that this would provide a
most conservative estimate of potential negative ecological effects.
The potential for negative ecological impact associated with the ALOU is considered
minor. The most significant potential risk associated with the site resultS from ground
water ingestion, and there is no potential ecological exposure route 10 ground water. If
there were any potential risk associated with the refuse disposed at the site, it wiJl be
eliminated once the site is capped
2.7 Description of the "No-Action" AltemaUve
The Anny, EPA and ODEQ have agreed that results of the environmental investigations
and the human health risk assessment performed at the ALOU demonstrate that it does
not pose a significant risk to human health and the environmenL In addition, the landfill
is scheduled to stop receipt of municipal waste on October 9, 1993, but may receive
treated soil from the Deactivation Furnace Area until late 1994. The landfill will be
capped and. closed in accordance with Oregon Stare Solid Waste Regulations which
require a low penneability cap consisting of 18 inches of compacted soil with a
PJ:rmeability no greater than lO-5 cm/second. Ground water monitoring. which is also
required by Oregon State Solid Waste Regulations, will be performed for five years after
closure to ensure that the landfill does not constitute a source of contamination. Based
on this info.rmation, it was decided that a "No-Action" remedial remedy is sufficiently
- protective of human health and the environmenL
870828119' .AOOXTNE.03/2MI3
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In. choosing the no further action alternative. EPA reserves its authority to perfonn
additional response actions should new information necessitate such a decision.
2.8 Documentation of Significant Changes
\
The remedy documented in this ROD is the same as the preferred alternative presented
in the Proposed Plan for the ALOU. The final remedy has nOt undergone any significant
changes, however the schedule for closing the Active Landf1l1 has been extended from
late. 1993 to late 1994.
170828\ TEP .ROO.ACTJYE.cnM13
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Section 3
Responsiveness Summary
(
,
,
The final component of the ROD is the Responsiveness Summary, ~hich serves two
purposes. First. it provides the agency decision makers with information 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 a pan of the decision-malcing process.
Historically, community interest in the UMDA installation has centered on the impacts
of installation operations on the local economy. Interest in the environmental impacts of
UMDA activities has typically been low. Only the proposed chemical demilitarization
pro~ which is separate from CERCLA remediation programs, has drawn substantial
comment and concern.
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 sUIT'Ounding communities. Quanerly meetings provide an
opportunity for UMDA to brief the TRC on installation environmental restoration
projects and to solicit input from the TRC. The TRC was briefed on August 12, 1992
on the scope and results of the supplemental investigation and the methodology of the
preferred alternative presented in the proposed plan. The response received from the
TRC was positive.
Notice of the public comment period. public meeting, and availability of the Proposed
Plan was published in the Hermiston Herald, the Tri-Ciry Herald. and the East
Oregonian in September 1992.
The Proposed Plan for the Active Landfill Operable Unit was released to the public on
August 31, 1992. The public comment period started on that date and ended on
September 30, 1992. The documents constituting the administrative record were made
available 10 the public at the following locations: UMDA Building 1, Hermiston,
Oregon; the Hermiston Public Library, Hermiston, Oregon; and the EPA Office in
Ponland, Oregon.
A public meeting was held at Armand Larive Junior High School, Henniston, Oregon,
on September 15, 1992. to inform the public of the preferred alternative and to seek
public comments. At this meeting, representatives from UMDA, USATHAMA, EPA,
ODEQ, and Anhur D. Little, Inc. presented the proposed remedy. Approximately ten
persons from the public and media attended the meeting.
No comments or questions regarding the proposed alternative, either verbal or written,
were received by UMDA, EPA, or ODEQ during the public meeting or during the
comment period. .
87'08281TE?AOC.ACTI\/E.~
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Appendix 1
State 01 Oregon's Letter 01 Concurrence
87a1121!11 TEP JIOO.ACT1VE.O:r2MI3
...,
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Oregor
.-'
.
.
OCTOBER 20, 1992
DEPARTME\iT C
ENVI RON~.tENT.-\
Ms. Dana Rassmussen
Regional Administrator
U. S. Environmental Protection Agency
1200 Sixth Avenue '
Seattle, WA 98101
QUALITY
Re:
Umatilla Depot Activity
Active Landfill Operable Unit
Record of Decision
Dear Ms. Rassmussen:
The Oregon Department of Environmental Quality tDEQ) has reviewed the draft Record
of Decision, for the Active Landfill Operable Unit at the U.S. Army's Umatilla Depot
Activity. I am pleased to advise you that DEQ concurs with the no-action remedy
recommended by EP A and the Army. I find that this alternative is protective, and to
the maximum extent practicable is cost effective, uses permanent solutions and
alternative technologies, is effective and implementable. Accordingly, it satisfies the
requirements of ORS 465.315, and OAR 340-122-040 and 090.
It is understood that the active landfill will be properly closed under the Solid Waste
Disposal Permit issued by this Department, and in accordance with the Department's
solid waste management regulations. DEQ's closure requirements for this site have
not yet been finalized, but will likely include a low permeability soil cap, and
groundwater monitoring for a minimum of five years after closure.
If you have any questions concerning this maner, please contact Mr. William Dana of .
the Department's Environmental Cleanup Division, at (503) 229-6530.
Sincerely,
~~~
Fred Hansen
Director
WD:m
SITE\SM35\SM4681
cc:. Lewis D. Walker, DOD
LTC. William McCune, UMDA
Harry Craig, EPA-OOO
Bill Dana, SRS, DEQ
~
.
811 s\.\' Sixth Aven U~
Portland. OR 9~~ 1.'
\5031 "')9-5696
TDD (5031 :!.."'9-6993
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