United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R05-92/200
March 1992
Superfund
Record of Decision:
Savanna Army Depot, IL
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NOTICE.
The appendices listed in the index that are not found in this document have been removed at the request of
the issuing agency. They contain material which supplement. but adds no further applicable information to
the content of the document. All supplemental material is, however, contained in the administrative record
for this site.
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c.
50272.101
REPORT DOCUMENTATION 11. REPORT NO.
PAGE EPA/ROD/R05-92/200
I ~
3. Reclplenr. A_elon No.
4. TIlle end Sublllle
SUPERFUND RECORD OF DECISION
Savanna Army Depot, IL
First Remedial Action - Final
7. Author(.)
5. Report Date
03/31/92
6.
8. Performing Orglln\z.ellon Repl No.
9. Performing Orglliniullon N.me end Addr-
10. Projecl1T88klWorII Unit No.
11. Contrect(C) or Grent(G) No.
(C)
(G)
12. Sponeorlng Orgllnlullon Neme end Addr-
U.S. Environmental Protection
401 M Street, S.W.
Washington, D.C. 20460
13. Type 01 Report. Period Covered
Agency
800/000
14"
15. Supplementary NoI88
PB93-964116
16. Abelr8ct (Umlt: 200 word8)
The Savanna" Army Depot Activity (SVADA) site, an active military installation, is
located 70 miles west of Rockford, Illinois, in a remote and sparsely populated area.
Land use in the area is predominantly agricultural and recreational, with a wetlands
area located onsite. Part of the site lies within the 50-year floodplain of the
Mississippi River. From 1943 to 1969, ammunition washout operations were conducted in
the northwestern portion of the facility. As a result, wastewater containing explosive
compounds was produced, discharged to a drain trough, and piped to four unlined
lagoons, referred to as the "lower lagoons," which drained into a ditch and onto the
Mississippi River. In 1961, two new unlined lagoons, or .upper lagoons," began
receiving the wastewater, thus replacing the lower lagoons. Wastes that flowed into
the upper lagoons drained into the soil below them. The TNT washout facility has not
been operational since 1969, and the lagoon areas are currently not in use. Since
1979, the SVADA lagoon areas have been the subject of several U.S. Army investigations,
which revealed significant contamination of the soil with high concentrations of the
explosive trinitrotoluene (TNT) and other organic compounds. The soil is also a
continued source of ground water contamination. This ROD addresses a final remedy for
(See Attached Page)
17. Document Analysis e. o...crlptore
Record of Decision - Savanna Army Depot, IL
First Remedial Action - Final
Contaminated Medium: soil
Key Contaminants: Organic explosives (TNT, 2,4-DNT, 2-A-4,6-DNT, TNB, RDX, NB)
b. Idenllller8lOpen-Ended Term.
c. COSA TI FIeld/Group
18. Availability Statement
19. Security Cle.. (Thl. Report)
None
20. Security Cle.. (This Page)
None
21. No. 01 Pegee
74
I
2~ PrIce
(See ANSI-Z39.1B)
See In.tTuctJon. on RfN8f8.
272 (4-77)
(Formerty NTIS-35)
Department 01 Commerce
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EPA/ROD/R05-92/200
Savanna Army Depot, IL
First Remedial Action
Final
Abstract (Continued)
the Washout Lagoon Area Soil at SVADA as OU1. A future ROD will address the ground water
in the vicinity of the lagoons. The primary contaminants of concern affecting the soil
are organics, including TNT; nitrobenzene (NB); 2,4,6-TNT; 2,4-dinitrotoluene (DNT);
2-amino-4,6-DNT; 1,3,5-trinitrobenzene (TNB);and hexahydro-1,3,5-trinitro-1,3,5-triazine
(RDX) .
The selected remedial action for this site includes excavating an estimated 18,230 cubic
yards of contaminated soil in the upper and lower lagoons, drain troughs, and piping, and
onsite thermal treatment by rotary kiln incineration, followed by onsite disposal of the
treated soil and fly ash in the upper lagoon area. Treated soil that fails the hazardous
waste characteristic tests will be reprocessed. Treated soil not meeting TCLP clean-up
standards will be stabilized prior to disposal. Standing water in the lagoons will be
decanted and treated, if necessary, and any affected wetlands will be restored.
Perimeter air monitoring will also be conducted during site operations. The estimated
present worth cost for this remedial action is $10,251,000, which includes an annual O&M
cost of $11,400 for 2 years.
PERFORMANCE STANDARDS OR GOALS: Chemical-specific soil clean-up goals are based on
health-based criteria and include TNT 21.1 mg/kg; 2,4-DNT 9.3 mg/kg; 2-A-4,6-DNT
1191 mg/kg; 1,3,5-TNB 3.7 mg/kg; RDX 5.75 mg/kg; and NB 37.2 mg/kg. Treated soil will be
subjected to TCLP and testing for other hazardous waste characteristics. Residual soil
left in the ground will have no concentrations of explosive compounds that are greater
than health-based criteria.
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u.s. ARMY INSTALLATION
RESTORATION PROGRAM
DEFENSE ENVIRONMENTAL RESTORATION PROGRAM
RECORD OF DECISION
SAVANNA ARMY DEPOT ACfM1Y (SVADA), ILLINOIS
WASHOUT LAGOON AREA SOILS OPERABLE UNIT
MARCH 1992
In accordance with Army Regulation 200-2 this document is intended by the Army to
comply with the National Environmental Policy Act (NEPA) of 1969.
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TABLE OF CONTENTS
Section Title ~
1 DECLARATION OF THE RECORD OF DECISION 1-1
2 DECISION SUMMARY 2-1
2.1 Site Name, Location, and Description 2-1
2.2 Site History and Enforcement Activities 2-8
2.3 Highlights of Community Participation 2-9
2.4 Scope and Role of the Washout Lagoon Area
Soils Operable Unit 2-10
2.5 Summary of Site Characteristics 2-11
2.6 Summary of Site Risks 2-14
2.7 Development of Remedial Action Levels 2-19
2.8 Description of Alternatives 2-24
2.8.1 Alternative 1: No Action 2-24
2.8.2 Alternative 2: Umited Action Consisting of Institutional
Controls 2-25
2.8.3 Alternative 3: Excavation of Lower Lagoon Area
Soils and Capping of Both Upper Lagoon and Lower
Soils in the Upper Lagoon Area 2-26
2.8.4 Alternative 4: On-Site Composting and On-Site
Disposal of Upper and Lower Lagoon Area Soils 2-28
2.8.5 Alternative 5: On-Site Solvent Extraction and
On-Site Disposal of Upper and Lower Lagoon Area Soils 2-31
2.8.6 Alternative 6: On-Site Thermal Treatment and On-Site
Disposal of Upper and Lower Lagoon Area Soils 2-34
2.8.7 Alternative 7: Off-Site Thermal Treatment and Off-Site
Disposal of Upper and Lower Lagoon Area Soils 2-38
2.9 Summary of Comparative Analysis of Alternatives 2-40
2.9.1 Threshold Criteria 2-41
2.9.1.1 Overall Pro~ection of Human Health and
the Environment 2-41
2.9.1.2 Compliance with Applicable or Relevant
and Appropriate Requirements (ARARs) 2-42
2.9.2 Primary Balancing Criteria 2-43
2.9.2.1 Long-Term Effectiveness and Permanence 2-43
2.9.2.2 Reduction of Toxicity, Mobility, and Volume
of Contaminants 2-44
2.9.2.3 Short-Term Effectiveness 2-45
2.9.2.4 Implementability 2-46
2.9.2.5 Cost 2-47
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Section
3
1242.rdr
TABLE OF CONTENTS
( continued)
Title
Pa2e
2-48
2-48
2-49
2-49
2-51
2-52.
2-53
2-53
2-54
2-54
2-55
2-58
2.9.3 Modifying Criteria
2.9.3.1 EPA/IEPA Acceptance
2.9.3.2 Community Acceptance
2.10 Selected Remedy
2.10.1 Remediation Goals
2.11 Statutory Determinations
2.11.1 Protection of Human Health and the Environment
2.11.2 Compliance with ARARs
2.11.2.1 Chemical-Specific ARARs
2.11.2.2 Location-Specific ARARs
2.11.2.3 Action-Specific ARARs
2.11.3 Cost-Effectiveness
2.11.4 Utilization of Permanent Solutions and Alternative
Treatment Technologies or Resource Recovery Technologies
to the Maximum Extent Practicable ("MEP") 2-59
2.11.5 Preference for Treatment as a Principal Element 2-60
2.12 Documentation of Significant Changes 2-61
RESPONSIVENESS SUMMARY
3-1
3.1
3.2
3.3
Overview
Background on Community Involvement
Summary of Public Comments and Army /EP A/IEP A Response.
3-1
3-1
3-2
11
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DECLARATION OF THE RECORD OF DECISION
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RESPONSIVENESS SUMMARY
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SEcnON 1
DECLARATION OF THE RECORD OF DECISION
Site Name and Location
Savanna Army Depot Activity
Highway 84 North
Savanna, Illinois 61074
Statement of Basis and Purpose
This decision document presents the selected remedial action for the Savanna Army Depot
Activity (SV ADA) Washout Lagoon Area, in Savanna, Illinois, which was chosen in
accordance with the Comprehensive Environmental Response, Compensation, and Liability
Act o~ 1980 (CERCLA), 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). This decision is based on the administrative
record for this site and has been made by the United States Environmental Protection
Agency (U.S. EPA) in consultation with the Illinois Environmental Protection Agency
(IEPA) and the U.S. Army. .
Assessment of the Site
Actual or threatened releases of hazardous substances from this site, if not addressed by
implementing the response action selected in this Record of Decision (ROD), may present
an imminent and substantial endangerment to public health, welfare, or the environment.
D
The scope of this ROD is limited to remediation of only the Washout Lagoon Areas Soils
Operable Unit at SV ADA The U.S. EPA, the IEPA, and the U.S. Army have agreed to
consider the affected lagoon soils at the SV ADA Washout Lagoon Area as an operable unit
for which remedial alternatives can be considered. Groundwater in the vicinity of the
lagoons is currently being addressed in a facility-wide remedial investigation and will be
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remediated under a separate ROD. Remedial objectives were developed for the soils to
prevent further degradation of the groundwater above health-based levels and to reduce
risks of endangerment to public health, welfare, or the environment to acceptable levels.
The cleanup levels that were determined to be protective of human health and the
environment are presented in Table 1.
The selected remedy is On-Site Thermal Treatment (rotary kiln incineration) and On-Site
Disposal of Upper and Lower Lagoon Area Soils. The major components of the selected
remedy for the Washout Lagoon Area Soils Operable Unit include the following:
. Pipe removal.
. Excavation of contaminated soils in the following areas:
Drain trough.
Lower lagoons.
Upper lagoons.
Around the removed underground pipe.
. Verification sampling to document cleanup levels.
. On-site thermal treatment by rotary kiln incineration of the contaminated soils.
. On-site disposal of treated soils.
. Decanting and treatment of standing water in the lagoons (if needed).
. Any affected wetlands will be restored. One option to restore wetlands may be
establishing original contours.
. Perimeter air monitoring to ensure that site activities do not impact areas beyond
the area of contamination.
All activities required by this ROD will be carried out in accordance with procedures
approved by the U.S. EPA, the IEPA, and the U.S. Army. Such activities will meet all
applicable regulating requirements and will be consistent with all applicable or relevant and
appropriate requirements (ARMs).
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Table 1
Remedial Action Cleanup Levels
for the SVADA Washout Lagoon Area SoUsa
Compound Concentration (mgjkg)
TNT 21.1
2,4-DNT 9.3
2-A-4,6-DNT 1191
TNB 3.7
RDX 5.75
NB 37.2
1,3-DNBb 7.4
2,6-DNTb . 4.2
HMXb 3722
Tetrylb 112
a
These cleanup levels are levels to which the contaminated soils must be excavated
to be protective of human health at a target carcinogenic risk level of 10-6 and a
hazard quotient of 1. The only exception to this is the cleanup level of 9.3 mg/kg
for 2,4-DNT which is protective of human health at a target carcinogenic risk level
of 10-5.
b
Contaminants found in groundwater only, not in soil.
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lO2S.cad
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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
satisfies the statutory preference for remedies that employ treatment that reduce toxicity,
mobility, or volume as a principal element.
Because this remedy will not result in hazardous substances remaining in on-site soils above
health-based levels, a five-year review will not apply to this action for the contaminated
soils.
U.S. Army Installation Restoration Program
Record Of Decision
Savanna Army Depot Activity, Illinois
Washout Lagoon Area Soils Operable Unit
-pp2
Adamkus
Regio al Administrator
Region V
U.S. Environmental Protection Agency
Date
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Concurrence With:
u.s. Army Installation Rtstor~iluil Program
ReeoJ"d Of Decision
Savar.:na Army Depot A~Uvity. Illinol£
Washout Lagoon Arei Soils Operable Unit
AL~ ~~
~."'..., I' Vi.
",./ Jdhn K. Phmis~ jr.
( tTC. OD .
L/Comrna.'1ding
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ConCi:.rrencc With:
U.s. Army In~tallation Rc&tVl&tion Progt'ilm
Record Of Decision
Savanna AJmy Depot Activity, Illinois
Wasbl>i.lt I...agcon Arei SoHs Operabl~ Unit
c£~b IW~-
Lewis D. Wilk~t
J ,/"3 tJ /9 7--
Date
DaP"1\1 A ""'stAnt S..1cr-t-N or ,.,.... . H""'''
'" Y '/ "'I" G v C .C." J He /'\J ...,
EnvlI'1)M1ent. Safety. And OcciJpationa1 l1eahh .
Offi~c Of The ~slsiilm Sterciery
0, 1". 6 ~v '9 -nd 9 '\
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DECISION SUMMARY
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SECTION 2
DECISION SUMMARY
This Decision Summary provides an overview of the problems posed by the conditions at
the site, the remedial alternatives, and the analysis of those options. This Decision
Summary explains the rationale for the selection and how the selected remedy satisfies
statutory requirements.
The background documents for the information contained in Subsections 2.1 through 2.11
are listed below:
. Final Remedial Investi~ation for the TNT Washout Facility Lagoons. Site No. 21
and 22. Savanna Army Depot Activity (SV ADA), October 1991, prepared by
Dames & Moore for USAlHAMA Contract No. DAA15-88-D-0008.
. Feasibility Study for the Savanna Army Depot Activity (SV ADA) Washout
La~oon Arei!, December 1991, prepared by Weston Services, Inc. for the U.S.
Army Corps of Engineers Kansas City District.
. Proposed Plan for the Savanna Army Depot Activity (SV ADA) Washout Lagoon
~ December 1991, prepared by Weston Services, Inc; for the U.S. Army
Corps of Engineers Kansas City District.
2.1
SITE NAME. LOCATION. AND DESCRIPTION
SV ADA is located in the northwest comer of Illinois approximately 70 miles west of
. Rockford, Illinois, as shown in Figure 1. The Washout Lagoon Area is located in the
northwest comer of the facility, near the Mississippi River Lock and Dam No. 12 as shown
in Figure 2 and a schematic diagram of the Washout Lagoon Area is presented in Figure
3.
AS shown in Figure 3, the Washout Lagoon Area primarily consists .of a series of four
unlined "lower" lagoons that lie within the 50-year flood plain of the Mississippi River and
two "upper" unlined lagoons that lie above this flood plain. These lower and upper lagoons
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N
I
N
WISCONSIN
o
IOWA
ILLINOIS
~
o
I
SCALE
Chlcaqo
79IKm
ChIcago
287Km
, 6M,le$
.
WISCONSIN ~
8. ,~
Rockford
\
INDIANA
ILLINOIS
FIGURE 1 SVADA GENERAL SITE LOCATION
Source: Dames & Moore ('99')
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-:'.17
IV
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General Vicinity 01
VVashoutlagoonArea
Crooked Slough
Administration
Area
'0"'&
Source: Dames & Moore (1991)
FIGURE 2 SVADA INSTAllATION MAP
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TNT Washout Facility
Main Process Building
Drain Trough
Lower Lagoons
599-6227i
~
"
Upper Lagoons
~ Unde~ground Pipe
I
I
I
I
I
I
I
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I
I
,
,
~
-N.
a
Not to Scale
FIGURE 3 SVADA WASHOUT LAGOON AREA
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are connected to the main TNT Washout Facility building by a drain trough and
underground piping, respectively.
The area of the site south of West Road (shown on Figure 3) gently slopes down to the
Mississippi River with a maximum elevation of approximately 600 feet (ft) above mean sea
level (msl) at the road and an elevation of approximately 586 ft above msl at the river. The
lower lagoons lie within this area and also within the 50-year flood plain of the Mississippi
River.
The area of the site north of West Road consists of gently sloping hills with a maximum
elevation of approximately 660 ft above msl at the upper lagoons and a minimum elevation
of approximately 600 ft above msl at the road. The upper lagoons are not located in the
flood plain of the Mississippi River. .
During high water levels of the Mississippi River and/or heavy rains, the lagoons may
contain standing water; however, under average weather conditions, they do not contain
standing water and do not support aquatic life. The area adjacent to the lagoons is highly
vegetated. Hab~tats in the vicinity of the lower lagoons consist of forested wetlands,
emergent wetlands, shallow open water wetlands, sloughs, side channels, and backwater
lakes. Wildlife access to the site is unrestricted and deer tracks have been observed in the
vicinity of the lower lagoons.
The site is located in a fairly remote, sparsely populated area on the boundary of Carroll
and Jo Daviess Counties. Jackson County, Iowa, is located across the Mississippi River from
SV ADA The population density ranges from 35 to 40 persons per square mile in all three
. counties. Carroll and J 0 Daviess Counties are developed predominantly as farmland, while
Jackson County has slightly less farming.
SV ADA lies close to the southern edge of the Upper Mississippi Valley mining district that
comprises an area of approximately 4,000 square miles. The primary mineral deposits are
zinc and lead. Most of the production is limited to an area of 650 square miles in a belt
extending north and south of the central part of the district.
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The surface water hydrology of SV ADA can be divided into three distinct features as
follows:
. Rivers and streams - SV ADA is bordered on the west by the Mississippi River.
In 1982, the pool elevation upstream of the dam was 591 ft above msl and the tail
water elevation was 586 ft above msl. SV ADA is also bordered on the east by
the Apple River, which flows into the Mississippi at the southeast corner of the
depot (see Figure 4).
At least three intermittent streams are located to the northeast of SV ADA
However, only one of these streams is illustrated in Figure 4; the other two
terminate in the vicinity of the northeastern facility boundary.
Pronounced drainage patterns on most of the installation are lacking. Generally,
the western half of the installation which includes the Washout Lagoon Area,
drains either directly or indirectly by sloughs into the Mississippi River.
. Mississippi backwater area - The Mississippi River backwater area is located
southeast of Lock and Dam No. 12 (Figure 4) and is composed of recent ~luvial
. deposits from the Mississippi River. These sediments are unconsolidated and are
continually reworked by a maze of sloughs that drains the area into the
Mississippi River. Backwater generally flows in the direction of the river. This
land is only slightly elevated above the water level of the Mississippi River and
is subject to seasonal flooding.
. Swampy woundwater rechar~e area - The swampy groundwater recharge area
is located centrally along the northern boundary of SV ADA, as seen in Figure 4.
Pronounced drainage patterns are lacking throughout most of the installation,
because of the highly permeable, sandy soils that allow percolation of
precipitation directly into.the soil. Several intermittent streams, not depicted in
Figure 4, provide surface water runoff to the swampy groundwater recharge area.
This area generally receives more surface runoff than can percolate through the
soil, thus resulting in a high water table and swampy surface conditions.
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General Vicinity 01
Washout lagoon Area
INrfRM,TTfNT
srREAM
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~,
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, ~x,~ww;-
IOWA
Facility BOUful"y
Surlue W,ter
Gene"liled 1 opo9"phic low,
Swampy Grounrfw,le, Rrr.ha'ge Area
Backw,Ir, Area Bounda'y
Gr.ne,,1i led T npoglal'hir. 11'9'"
MISSISSIPPI RIVER
BACKWATER A"EA
o Yo I Mile
. . .
qJ
FIGURE
4 DOMINANT SURFACE WATER DRAINAGE FEATURES AT SVADA
Source: Dames & Moore (19911
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Tbe water table beneath the lower lagoons is approximately 9 to 13 feet below land surface,
and the water table at the upper lagoon lies approximately 43 to 45 feet below land surface.
Groundwater flow in the vicinity of the upper and lower lagoons appears to be to the
southwest, toward the backwater of Crooked Slough and the Mississippi River, with some
variation to the south and southeast. Groundwater movement appears to be slow because
of the very low gradient in the area.
2.2
SITE HISTORY AND ENFORCEMENT ACTMTIES
Between 1943 and 1969, ammunition washout operations were conducted in the north-
western portion of the SV ADA facility. Tbese operations consisted of washing out bombs,
projectiles, and/or ammunition using high pressure (90 to 125 pounds per square inch (psi)
and high temperature (180° F or 5° F below the local boiling point) water. As a result,
wastewater containing explosives compounds, principally 2,4,6-trinitrotoluene (TNT), was
produced. The wastewater flowed from settling tanks via an aboveground drain trough
to th~ four unlined lagoons located in the 50-year flood plain of the Mississippi River.
These "lower" lagoons (Le., lagoons 1, 2, 3 and 4) were connected by overflow drains and
operated in series; explosive particles that were present in the wastewater settled to the
bottom of these lagoons. The final discharge from these lagoons was directed to an
overflow ditch that leads to Crooked Slough, which flows to the Mississippi River. At the
present time, the lower lagoons typically contain standing water from rainfall.
Starting in 1961, wastewater flow to the lower lagoons ceased. Wastewater was pumped via
an underground pipeline into two new unlined . lagoons (Le., lagoons 5 and 6) on a hill
overlooking the washout plant. These "upper" lagoons have no discharge outlets, and there
are no signs that overflow occurred during their use. Water that flowed into the upper
lagoons was allowed to filter through to the soils below these lagoons.
Currently, land at the upper and lower lagoons is not used for any particular purpose. The
TNT Washout Facility haS not been operational since 1969. Access by off-site personnel is
restricted, but access by SV ADA personnel is not restricted. However, because the TNT
Washout Facility is not operational, and other military activities are not conducted in the
area, it is not expected that SV ADA personnel would visit the lagoons during normal work
activities, except for facility security purposes, which includes a "drive-by" observation from
a security vehicle.
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Recreational activities in the vicinity of the TNT Washout Facility are generally restricted.
Current access to the site by wildlife, such as deer, is unrestricted, and deer tracks have been
observed in the vicinity of the lagoons. Deer harvesting is allowed in the area by permitted
hunters (employees of SV ADA). Commercial fishing is permitted in the Mississippi River,
and recreational fishing is permitted in the downgradient surface water of Crooked Slough
and in the Mississippi River. The lagoons and the land immediately surrounding the
lagoons are not used for cattle grazing or farming.
The SV ADA Washout Lagoon Area has been the subject of numerous field investigations
since 1979. The investigations are summarized as follows:
. USATHAMA. 1979 . In January 1979, the United States Army Toxic and
Hazardous Materials Agency (USATHAMA) published an Installation
Assessment which identified potential sites at SV ADA that might contain
hazardous materials. The Washout Lagoon Area was identified in this report as
a potential site.
. Environmental Science and Enaineerine. Inc. (ESE). 1982 . In 1982, ESE
published the results of an environmental survey for SV ADA to determine which
sites identified by USA THAMA in the Installation Assessment warranted further
field investigation. This survey included collection of surface soil, surface water,
and sediment samples from the lagoons, the overflow ditch, Crooked Slough, and
a background sample location.
. WESTON. 1984 . In 1984, Roy F. Weston, Inc. (WESTON) published
"Engineering Analysis of Alternative Remedial Measures." This report included
a summary of a sampling program conducted by WESTON from 15 January to
8 February 1983, which was designed to characterize the soils in the lagoons and
associated appurtenances.
. Dames & Moore. 1991 . As part of the Remedial Investigation (RI), Dames &
Moore conducted an investigation referred to as the "lagoon special effort." This
investigation was conducted at the request of the EP A to better define the lateral
extent of contamination around the lower lagoons.
2.3
HIGHLIGHTS OF COMMUNITY PARTICIPATION
Compliance with the public participation requirements of CERCLA/SARA (Section 113
(k)(2)(B)(i-v) has been achieved for the SV ADA Washout Lagoon Area. The Feasibility
Study and the Proposed Plan for the SV ADA Washout Lagoon Area were released to the
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public on January 6, 1992. The public comment period started on January 6, 1992 and
ended on February 6, 1992. These and other documents concerning SV ADA were made
available to the public at the Savanna Public Library and the Savanna Army Depot Activity,
both in Savanna, Illinois. The notice of availability of the Proposed Plan was published in
the Savanna Times Journal on December 18, 1991, and in the Clinton Herald, Bellevue
Herald Leader, Galena Gazette, and Dubuque Telegraph Herald, all prior to December 22,
. 1991. A public meeting was held on January 22, 1992 to inform the public of the preferred
alternative and to seek public comments. At this meeting, representatives from SV ADA,
U.S. EPA, IEPA, U.S. Army, and Weston Services, Inc. (a remediation contractor, a/k/a
Roy F. Weston, Inc.) answered questions about the site and the remedial alternatives under
consideration. A response to the comments received during this period is included in the
Responsiveness Summary, which is a part of this Record of Decision.
2.4 SCOPE AND ROLE OF THE WASHOUT LAGOON AREAS SOILS OPERABLE UNIT
Operable units are defined as discrete actions that comprise incremental steps toward the
final overall remedy. Operable units may be actions that completely address a geographic
portion of a site or a specific problem, or may be one of many actions that will be taken at
the site.
The Washout Lagoon Area Soils Operable Unit cleanup strategy is considered a final action
for only the contaminated soils within the Washout Lagoon Area. A final remedy for the
remaining portions of the SV ADA facility, including the Washout Lagoon Area
groundwater, will be proposed following the. completion of the facility-wide investigation
currently in progress. No further action will be planned for the Washout Lagoon Area soils
after the selected remedy is implemented.
The threats addressed in this ROD are the contaminated soils in the Washout Lagoon Area.
Actual or threatened release of hazardous substances from the contaminated lagoon soils,
if not addressed by implementing the selected remedy, may present a current or potential
threat to public health, welfare and the environment.
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2.5
SUMMARY OF SITE CHARACfERISTICS
The principal threat wastes at the SV ADA Washout Lagoon Area are the contaminated
soils which act as a source of continued groundwater contamination. These source materials
would also present a significant risk to human health and the environment should direct
exposure occur.
The known and suspected sources of contamination at the SV ADA Washout Lagoon Area
are the lagoons, drain trough, overflow ditch, and associated underground piping at the
upper lagoons. As noted, the type of contamination is explosive compounds with the most
prevalent compound being TNT. This compound can be toxic to human health and may be
both carcinogenic and mutagenic. The volume of affected soils is estimated to be
approximately 18,230 cubic yards (yd3).
The following results of the ESE survey (1982) are discussed as they apply to the Washout
Lagoon Area as a whole. More detail is provided in the Remedial Investigation Report.
The soil samples from the lagoons showed TNT concentrations ranging from 2,870
. milligrams per kilogram (mgjkg) to approxim4tcly 50 percent (by weight) which can also be
expressed as 500,000 mg/kg. One soil sample from the lagoons showed a 2,4-dinitrotoluene
(2,4-DNT) concentration of 94.2 mg/kg. The overflow ditch soil sample showed a TNT
concentration of 1,890 mg/kg and a 2-amino-4,6-dinitrotoluene (2-A-4,6-DNT) concentration
of 300 mg/kg. The sediment sample from Crooked Slough, where the overflow ditch from
the lagoons meets the slough, did not contain detectable levels of explosives compounds.
The background soil sample did not contain any analytes above the detection limit. These
results indicated that a more thorough investigation of the lagoons and associated
appurtenances was warranted.
A total of 215 soil samples were collected during the WESTON investigation (1984) and
analyzed for the following explosives compounds: octahydro-l,3,5,7-tetranitro-l,3,5,7-
tetraocine (HMX); hexahydro-l,3,5-trinitro-l~3,5-tri~~ (RDX); 1,3,5-trinitrobenzene
(TNB); 1,3-dinitrobenzene (1,3-DNB); Ditrobenzene (NB); TNT; 2-A-4,6-DNT; 2,6-
dinitrotoluene (2,6-DNT); and 2,4-DNT. These samples consisted of surface soil grab
samples, and samples from 5-ft, 2-ft, and 1.5-ft cores. Soil samples were also collected from
the Washout Lagoon Area for reactivity and extraction procedure (EP) leachate testing.
The results of the WESTON investigation are summarized as follows:
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. Lower Lai:oons - The compounds detected in the lower lagoons in order of
prevalence include: TNT, TNB, 2-A-4,6-DNT, RDX, and NB. The most
prevalent explosive compound detected in soil samples collected from these
lagoons was TNT, which was found in 91 of 97 samples. The maximum
concentration of TNT detected in each of the lagoons ranged from 8.5 percent
to 20 percent (by weight) which can also be expressed as 85,000 mg/kg to 200,000
mg/kg respectively. These maximum concentrations occurred at the 0 to I-ft
depth interval. The concentrations of TNT appeared to significantly decrease
with depth. Typically, TNT was detected at all the intervals where other
nitroaromatic compounds were detected, and at higher concentrations. Not all
samples were submitted for reactivity testing; however, soil samples from the
lower lagoons that were tested for reactivity were found to be nonreactive.. Soil
sample leachates were not EP toxic, that is, the leachate did not contain
concentrations of organic and inorganic compounds equal to or greater than
levels specified for classification as a toxic hazardous waste. .
. Upper Lai:oons - The compounds detected in the upper lagoons in order of
prevalence include: TNT, TNB, and RDX. The most prevalerit explosive
compound detected in soil samples collected from the upper lagoons was TNT,
which was found in 51 of 80 samples. The maximum concentrations of TNT
detected in lagoons 5 and 6 were 2.56 percent and 6.69 percent, respectively
which can also be expressed as 25,600 mg/kg and 66,900 mg/kg. Both
concentrations were found at the 0 to 0.5-ft depth interval. . The concentrations
of TNT appeared to significantly decrease with depth. . Typically, TNT was
detected at all the intervals where other nitroaromatic compounds were detected,
and at higher concentrations. Not all soil samples were submitted for reactivity
testing; however, soil samples from the upper lagoons that were tested for
reactivity were found to be nonreactive. Soil sample leachates were not EP toxic.
. Drain Trou~h - The compounds detected in soils below the drain trough in order
of prevalence include: TNT, 2,4-DNT, and TNB. (Note: Recent site visits
indicate that the trough is composed of metal, wooden sides have decayed or have
been removed). The most prevalent explosive compound detected in soil samples
from below the drain trough was TNT and was found in all four samples
collected. The maximum concentration of TNT detected was 567 mg/kg at a
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depth of 0.5 to 1.0 ft, the lowest depth sampled. TNT was detected at all the
intervals where other nitroaromatic compounds were detected and at higher
concentrations.
. Overflow Ditch - The compounds detected in the overflow ditch in order of
prevalence include: TNT, TNB, 2,A-4,6-DNT, NB, and RDX. The most
prevalent explosive compound detected in soil samples collected from the
overflow ditch was TNT and was found in all 32 samples. The maximum
concentration of TNT detected was 1.28 percent, which can also be expressed as
12,800 mg/kg. This concentration was detected at the 0 to 0.5-ft depth interval.
A range of 56 to 5,296 mg/kg was detected at the 1.0 to 2.0-ft depth interval, the
lowest depth sampled. TNT was detected at all the intervals where other
nitroaromatic compounds were detected, and at higher concentrations.
A total of 22 surface soil samples were collected during the Dames & Moore investigation
(1991) at locations downgradient from and around the four lagoons. Only one sample
showed any explosives contamination. This sample was collected from below the drain
trough and showed a concentration of 3.10 mg/kg TNT. The results of this effort indicated
that no further soils investigation of the Washout Lagoon Area was necessary and that the
lateral extent of contamination was contained in the lagoons.
The groundwater and surface water have also been studied in previous investigations.
Generally, in monitor wells located near the lagoons, TNT was found in groundwater at
concentrations up to 4,598 ug/L. The concentrations decrease with distance from the
lagoons. A surface water sample collected from lagoon 1 (lower lagoon) contained 16,600
ug/L TNT. The surface water and sediment ,sample from Crooked Slough contained no
explosives compounds.
According to the results of the remedial investigations, the lateral extent of contamination
does not appear to extend beyond the boundaries of the lagoons, drain trough, and overflow
ditch. The vertical extent of1he contamination at the upper lagoons is approximately 4 feet
below ground surface. The vertical extent at the lower lagoons is at least 5 feet below
ground surface, which is the lowest depth sampled.
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At the upper lagoons there is virtually no potential surface pathway of migration because
the lagoons are located on a topographic high for the vicinity and there is little run-on. In
addition, the high permeability of the upper lagoon soils allows for ready percolation of any
precipitation and as a result, there is no overflow or run-off from the lagoons. However,
due to this infiltration of rainwater, there is a potential subsurface pathway of migration for
the contaminants.
At the lower lagoons, there are both potential surface and subsurface pathways of migration.
The lagoons are located in the flood plain of the Mississippi River and 9 to 13 feet above
the water table. During flooding conditions, the potential for surface migration increases.
At the same time, the water table may rise and contact contaminated soils to increase the
subsurface potential for migration.
2.6
SUMMARY OF SITE RISKS
A b~eline risk assessment was conducted by Dames & Moore to estimate the risk posed
to human health and the environment by the contaminants at the Washout Lagoon Area
should it remain in its current state with no remediation. The baseline risk assessment is
comprised of a toxicity assessment, an exposure assessment, a human health risk evaluation,
and an ecological assessment for th~ explosive contaminants at the site. The purpose of the
risk assessment is to estimate human exposure concentrations for current and future land
use scenarios and to determine the potential human health and ecological risks.
Contaminants of concern are identified for each of the affected media (such as soil and
groundwater) at the site. Generally contaminants of concern are identified because of their
intrinsic toxicological properties, because they are present at elevated levels, or because they
are presently in or potentially may move into critical exposure pathways. The contaminants
of concern for the lagoon soils are listed in Table 2.
Risk assessments generally involve calculations for exposure risks to the contaminants of
concern based on a number of factors, some of which may be uncertain. When the value
of a factor is uncertain, then a conservative estimate or Reasonable Maximum Exposure
basis is used so that a conservative health-based exposure level or concentration can be
calculated. For example, in the Washout Lagoon Area risk assessment, if residential land
use is considered an operative exposure pathway, then values have been developed for the
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Table 2
Contaminants of Concern
for the Lagoon Soils
.
Compound
Acronym
2,4,6-trinitrotoluene
2,4-dinitrotoluene
2-amino-4,6-dinitrotoluene
1,3,5-trinitrobenzene
hexahydro-1,3,5-trinitro-1,3,5-triazine
nitrobenzene
TNT
2,4-DNT
2-A-4,6-DNT
TNB
RDX
NB
. Contaminants of concern based only on soil
sample results, groundwater contaminants of
concern are not included.
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most sensitive population, which is assumed to be children, even though in reality, children
may never occupy the subject area. It is also assumed that these children ingest a maximum
plausible amount of contaminated soil and the health-based exposure concentration of
contaminant is then calculated to be protective in this scenario.
The toxicity assessment documents the adverse effects that can be caused in a receptor as
a result of exposure to a site contaminant. The toxicity assessment considers the
relationship between dose and adverse responses, and a chemical's potential to c3:use other
adverse effects such as cancer. The exposure assessment details the exposure pathways
(such as drinking contaminated water) that exist at a site for various receptors such as
humans, wildlife, and the environment. In addition, it describes those pathways that may
exist in the future. In this assessment, one human exposure pathway was identified for the
current land use scenario. Eleven pathways were identified for the future land use scenario.
These pathways are listed in Table 3. Human exposure concentrations for each contaIninant
of concern were estimated for each pathway. .
The health risk evaluation uses both the exposure concentrations and toxicity data to
determine a hazard quotient for potential non-carcinogenic effects and a cancer risk level
for potentially carcinogenic contaminants. If the hazard quotient is below 1, then even the
most sensitive population is not likely to experience adverse health effects. If this hazard
quotient is above 1, there may be a concern for adverse health effects. The degree of
concern typically correlates with the size of the quotient if it is above 1. The cancer risk
level is the additional chance of cancer that may occur for a specific exposure population.
For example, if the cancer risk level is 10-6, there is one chance of cancer for 1,000,000
people exposed in addition to the normal occurrence of cancer in this population. The
estimated total hazard quotient and potential carcinogenic risks for each exposure pathway
are presented in Table 4. Values are shown for child and adult receptors.
The results of the ecological assessment indicate that the presence of soil contamination at
the site does have the potential to cause adverse ecological effects to terrestrial receptors.
The soil ingestion pathway is the predominant pathway. Adverse effects are not expected
to occur for the aquatic species if the groundwater plume should reach Crooked Slough in
the future.
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Table 3
Human Exposure Pathways Selected by
Quantitative Evaluation
CURRENT LAND USE
Recreational:
Pathway I--Consumption of deer that ingest contaminated vegetation and ponded water in
areas of contaminated soil.
FUTURE LAND USE
Recreational:
Pathway I--Consumption of deer that ingest contaminated vegetation and ponded water in
areas of contaminated soil.
Pathway 2--Consumption of fish that live in contaminated surface water of Crooked Slough.
Residential:
Pathway 3--Ingestion of contaminated soil by adult and child residents.
Pathway 4--Inhalation of contaminated soil as dust by adult and child residents.
Pathway 5--Ingestion of contaminated groundwater by adult and child residents.
Pathway 6--lnhalation of volatiles during indoor domestic uses (e.g., showering) by adult and
child residents. .
Pathw~ 7--Dermal absorption of contaminants in groundwater during indoor domestic uses
(e.g., showering) by adult and child residents.
Commen::ial/Industrial:
Pathway 8-- Inadvertent ingestion of contaminated soils by adult receptors during
occupational exposure.
PathwaY 9--Incidental inhalation of contaminated soils as dust by adult receptors during
occupational exposure.
Pathway lo--Ingestion of contaminated groundwater by adult receptors during occupational
exposure.
Military:
Pathway H--Incidental ingestion of contaminated soils by military receptors.
Source: Dames & Moore, 1991.
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Table 4
Total Cumulative Hazard Quotient and
Total Cumulative Potential Carcinogenic Risk for Each Exposure Pathway
Child Receptor Adult Receptor
Pathway HQ PCR HQ PCR
18 0.354 1.18x10-6 0.152 9.34xlO-7
2b 0.113 5.39x10-7 0.049 4.26x10-7
3c 1,550 2.72x10-3 166 1.02x10-3
4d 11.6 2.65x10-S 2.49 1.53x10-S
se 650 1.19x1O-3 279 9.43x104
6{ 27.4 1.25x104 5.88 7.23xlO-s
.", 1.16 8.85x10-6 0.59 7.42x10-6
8h NA NA 83.1 3.03x104
9i NA NA 2.49 9.1Ox10-6
10i NA NA 139 2.8W04
11" NA NA 10.4 1. 7Ox10-6
HQ=Total cumulative hazard quotient.
PCR=Total cumulative potential carcinogenic risk.
NA - Not applicable
8Consumption of deer that ingest contaminated vegetation and ponded water in areas of
contaminated soil by hunters and their families (current and future).
bConsumption offISh that live in contaminated surface water of Crooked Slough by adult and
child residents (future).
CIngestion of contaminated soil by adult and child residents (future).
dInhalation of contaminated soil as dust by adult and child residential receptors (future).
eIngestion of contaminated groundwater by adult and child residential receptors (future).
flnhalation of volatiles from groundwater during indoor domestic uses by adult and child
residents (future). .
gDermal absorption of contaminants in groundwater during indoor domestic uses by adult and
child residents (future).
~Ingestion of contaminated soil by adult occupational receptors (future).
'Inhalation of contaminated soil as dust by adult occupational receptors (future).
jIngestion of contaminated groundwater by adult occupational receptors (future).
"Ingestion of soil by military receptors (future).
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2.7
DEVELOPMENT OF REMEDIAL ACI10N LEVELS
Current information indicates that the contaminated groundwater has not migrated
significantly away from the TNT Washout Lagoon Area of the Savanna Army Depot.
Additionally, no evidence was found of contaminated groundwater discharging to the
Mississippi River or its backwaters. Therefore, there does not appear to be any current risk
to human health due to the contaminated groundwater. As a result, remedial action levels
are only developed at this time for the contaminated soils. The decision of whether or not
to remediate the contaminated groundwater will be made after additional ongoing
investigations are completed.
According to the National Contingency Plan (NCP) "...[R]emediation goals ... shall be
developed by considering the following factors: ... (1) For systemic toxicants, acceptable
exposure levels shall represent concentration levels to which the human population,
including sensitive subgroups, may be exposed without adverse effect during a lifetime or
part 'Of a lifetime, incorporating an adequate margin of safety..." In other words, for
noncarcinogens a hazard quotient of 1 or less is desired.
The NC~ continues by stating "...(2) For known or suspected carcinogens, acceptable
exposure levels are generally concentration levels that represent an excess upper bound
lifetime cancer risk to an individual of between 10-4 and 10-6 using information on the
relationship between dose and response. The 10-6 risk level shall be used as the point of
departure for determining remediation goals for alternatives when ARARs [applicable or
relevant and appropriate requirements] are not available.or are not sufficiently protective.."
Therefore, in most instances, for carcinogens, a potential carcinogenic risk of 10-6 is desired.
In the baseline risk assessment, remedial action levels were developed for various expected
and potential uses of the SV ADA Washout Lagoon Area. The exposure pathways were
combined to form various scenarios that represent the full range of potential uses for the
site. From these scenarios, combined remedial action levels (CRALs) that corresponded
to a total cumulative 10-6 excess cancer risk and a total cumulative hazard quotient (HQ)
of 1 were developed for the site contaminants.
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The CRALs were developed for both the contaminants of concern in .the soils that have
been listed in Table 2 and the contaminants of concern in the site groundwater. Certain
compounds were found in the groundwater and not the soils during the remedial
investigations (e.g. 1,3-DNB, 2,6-DNT, HMX, and tetryl). The possibility exists that these
compounds may potentially be encountered in soils during remedial activities, especially at
the bottom of excavations where groundwater may be present. As a result, although they
are not considered contaminants of concern for soils, they have been designated remedial
action levels so that they can be appropriately addressed if encountered during excavation
activities. The following summarizes the six potential combinations of multiple exposure
pathways for which CRALs have been developed.
. CRAL l--Combination of military and recreational land use pathways 1, 2, and
11.
. CRAL 2--Combination of occupational and recreational land use pathways,
assuming that groundwater is nQ1 used for drinking water - pathways 1, 2, 8, and
9.
. CRAL 3--Combination of occupational and recreational land use pathways,
assuming that groundwater is used for drinking water - pathways 1, 2, 8, 9, and
10.
. CRAL 4-Combination of residential land use pathways, assuming that
groundwater is used for domestic purposes - pathways 3, 4, 5, 6, and 7.
. CRAL 5--Combination of residential and recreational land use. pathways,
assuming that groundwater is used for domestic purposes - pathways 1, 2, 3, 4,
5, 6, and 7.
. CRAL 6--Combination of residential land use pathways, assuming that
groundwater is not used for domestic purposes - pathways 3 and 4.
The Army has chosen CRAL 1 and CRAL 6 to develop remedial action cleanup levels for
the Washout Lagoon Area. CRAL 1, which is a combination of Pathways 1, 2, and 11,
assumes that the receptors are military personnel who also hunt and fish at the facility.
CRAL 1 presents levels that are protective of human health for the current and expected
future use of the site. CRAL 1 is presented in Table 5.
CRAL 6, which is a combination of Pathways 3 and 4, assumes that there will be residential
land use in the future and the receptors, both child and adult, do not use site groundwater
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Table 5
Summary of Combined Remedial Action Levels (CRALs)
1 and 6 for Concentration of Contaminants in Sona
CRAL 1 (mgjkg) CRAL 6 (mgjkg)
Contaminant Carcinogenic Noncarcinogenic Carcinogenic Noncarcinogenic
TNT 680.7 1,642.7 21.1 37.2
2,4-DNT 12.5 9.3e
2-A-4,6-DNT 9,887.5 1,191.1
TNB 28.4 3.7
RDX 206.9 10,622.5 5.75 223.3
NB 299.2 37.2
1,3-DNBb,f 58.6 7.4
2,6-DN"fCof 4.21 9.3e
HMXd,f 25,697.3 3,722.1
Tetrylf 888.1 112.2
:...-
v
v
v'
./
v
v
/,
a The CRALs were developed to be protective of human health at a target carcinogenic risk level of 10-6
and a hazard quotient of 1.
b 1,3-dinitrobenzene
c 2,6-dinitrotoluene
d Octahydro-1,3,5,7-tetranitro- 1,3,5,7-tetraocine
e Protective of human health at a target carcinogenic risk level of 10-5
f Contaminants found in groundwater only, not in soil.
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for drinking or other purposes. Future groundwater usage is not assumed at this time since
the remedy is intended to address only exposure to the contaminated soil at the TNT
Washout Facility. However, even if future residential groundwater usage is assumed, the
remedial investigation shows that the proposed remedial action levels would fall within the
acceptable risk range of 10-4 to 10-6. Although it is unlikely that residential development
of the site will ever occur, the Army has chosen CRAL 6 as a conservative potential future
land use scenario. CRAL 6 is presented in Table 5.
The remedial action cleanup levels developed from CRAL 1 and CRAL 6 are presented in
Table 6. For the carcinogens, TNT and RDX, the most protective levels were selected from
CRAL 6. The dinitrotoluenes, the remaining two carcinogens, are not prevalent compounds
at the lagoons and were only detected in two of 49 sample locations. Since the
dinitrotoluenes do not appear to significantly contribute to the overall risks from the site,
the CRAL 6 risk level of 1 x 10-5 was considered acceptable only for these two compounds.
As a ,result, for these two compounds, CRAL 6 levels at the 1 x 10-5 total cumulative
potential carcinogenic risk (PCR) were compared to CRAL 1 levels at the 1 x 10-6 potential
carcinogenic risk. The lower of the two levels was then chosen as the remedial action
cleanup level. For 2,4-DNT, this is 9.3 mg/kg (Le., CRAL 6 at the 10-5 PCR) and for 2,6-
DNT, this is 4.2 mg/kg (Le., CRAL 1 at the 10-6 PCR). For the remainder of the
noncarcinogens, the most protective levels were selected from both CRAL 1 and CRAL 6.
Therefore, the chosen remedial action cleanup levels should be protective of human health
for the site's cutrent and future intended use in addition to potential future residential use,
which is considered by the Army to be unlikely. The residential use scenario is extremely
unlikely, based on the continued, and recently increased, mission responsibilities of SV ADA
However, it was considered prudent in this case to remediate to the more conservative
CRAL 6 levels to achieve a greater abatement of the source of groundwater contamination.
It is noted that the remedial action cleanup levels are the criteria to which soils are
excavated. These are not the same as treatment levels which are typically lower and apply
to treated soils. The treatment criteria are discussed in Subsection 2.10.1.
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Table 6
Remedial Action Cleanup Levels
for the SV ADA Washout Lagoon Area SoUsa
Compound Concentration (mgjkg)
TNT 21.1
2,4-DNT 9.3
2-A-4,6-DNT 1191
TNB 3.7
RDX 5.75
NB 37.2
1,3-I?NBb 7.4
2,6-DNTb 4.2
HMXb 3722
Tetrylb 112
a
These cleanup levels are levels to which the contaminated soils mu~t be excavated
to be protective of human health at a target carcinogenic risk level of 10-6 and a
hazard quotient of 1. The only exception to this is the cleanup level of 9.3 mgjkg
for 2,4-DNT which is protective of human health at a target carcinogenic risk level
of 10-5.
b
Contaminants founds in groundwater only, not in soil.
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,
Dames & Moore also conducted an ecological risk assessment. It contains the same basic
elements as the human health baseline risk assessment, such as a toxicity assessment,
exposure assessment, and risk characterization, except that these items apply to terrestrial
and aquatic wildlife. In general, the results of the ecological assessment indicated that the
presence of contamination at the lagoons does have the potential to adversely affect the
surrounding wildlife. The greatest existing risk to wildlife appears to be from the high
concentrations of TNT detected in the soil. Actual or threatened releases of hazardous
substances from this 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.
The risks to wildlife, while real and suggestive of the need for future detailed ecologic
assessment of the SV ADA environs. were not judged to be the dominant driving force for
the requirement for evaluation of remedial alternatives. At this time, it does not appear
that ~y critical habitats and endangered species or habitats have been significantly affected
by site contamination. Remedial alternatives identified on the basis of protection of human
health were judged to also likely be protective of the lc:al site ecology. Finally, a detailed
ecological risk assessment will be conducted In the facility-wide remedial
investigation/feasibility study (RI/FS).
2.8
DESCRIPTION OF ALTERNATIVES
Six remedial alternatives have been developed for the Washout Lagoon Area soils. A brief
description of the alternatives is provided in the following subsections.
2.8.1 Alternative 1: No Action
This alternative is evaluated as required by CERCI.A/SARA to provide a basis for
comparing existing site conditions with those resulting from implementation of the. other
evaluated alternatives.
In Alternative 1, no corrective measures are used to remediate contaminant sources or their
potential migration pathways. This alternative allows for the continued degradation of
groundwater and surrounding potential wetlands area. The risks presented in Table 4 for
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Q
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the current and future land use scenarios are not reduced. Alt:rnative 1 involves no capital
or operation and maintenance (O&M) costs.
The following major applicable or relevant and appropriate requirements (ARARs) and "to-
be-considered" (TBC) materials are cited for Alternative 1:
ARARS
Since the lagoons have a documented release, Resource Conservation and
Recovery Act (RCRA) Corrective Action requirements are considered
relevant and appropriate. Alternative 1 does not comply with this ARAR.
Since the lagoons may be considered waste management impoundments,
RCRA specifications for surface impoundments are relevant and appropriate.
Alternative 1 does not comply with these ARARs.
TBCs
In the absence of chemical-specific ARARs, cleanup criteria were developed
from "to-be-considered" (TBC) materials such as potency factors and reference
doses and have been presented in Table 6. Alternative 1 does not meet these
cleanup criteria.
2.8.2 Alternative 2: Limited Action Consistine of Institutional Controls
As in Alternative 1, no corrective measures are used to remediate contaminant sources or
their potential migration pathways. However, measures are taken to reduce potential risk
to public health, including establishing usage restrictions, deed restrictions,. and increased
security around the site. The usage restriction would prohibit any recreational, residential,
commercial/industrial, or military activities inside the restricted area. Signs posted on the
fences would alen civilian and military personnel to keep out of the area.
A deed restriction would alert prospective buyers of the imminent hazards posed by the site
contaminants and specify actions not allowed at the site. The. deed restriction would
prohibit the same actions as the usage restriction. In addition. it would specify that the
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fences remain intact and that the signs remain posted. A deed restriction would require
minimal legal administration to change the wording in the deed.
This alternative offers a slight risk reduction for human health over Alternative 1, however,
it is not protective of the environment and does not reduce environmental risks. As with
Alternative 1 this alternative allows for the continued degradation of groundwater and
surrounding potential wetlands area. It is expected that Alternative 2 would take 1 month
to implement.
The costs for Alternative 2 are as follows:
.
Capital - $233,000
O&M - . $3,OOOjyr for first 2 years
$2,SOOjyr for remaining 28 years
Total Present Worth ~ $271,000
The ARARs and TBCs previously cited for Alternative 1 also apply to Alternative 2.
Alternative 2 does not comply with any of these ARARs or TBCs.
2.8.3 Alternative 3: Excavation of Lower Laeoon Area Soils and CaQoinv of Both Upoer
Laeoon and Lower Las!Oon Soils in the Uoper Laeoon Area
Alternative 3 does not involve any treatment components, rather, it involves removal of the
sources of contamination in the lower lagoon area and along the underground pipe in the
vicinity of the upper lagoons, and placement of the excavated soils in the upper lagoon area.
The excavated lower lagoon and underground pipe soils are consolidated with the in-place
upper lagoon soils and covered with a RCRA Subtitle C compliant cap. The volume of soils
excavated is approximately 13,130 cubic yards (yd3). The total volume to be capped
including the in-place upper lagoon soils is 18,230 yd3.
It is expected that implementation of Alternative 3 would result in a reduction of the current
and potential future health risks presented in Table 4. A well constructed and maintained
cap can provide the protection specified under RCRA. However, with caps, the uncertainty
with long-term operation and maintenance is that the cap may eventually fail due to an
unnoticed fault in the cover. The residual levels for soils remaining in the lower lagoon
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0'" I
area are less than the health-based criteria. The soils consolidated in the upper lagoon area
will exhibit concentrations of explosives greater than the health-based criteria, however, they
will be contained under a cap. This alternative can be readily implemented as excavation
and cap construction utilizes proven technologies for conventional applications. It is
expected that this alternative ~ould take 8 to 14 months to implement.
The costs for Alternative 3 are as follows:
.
Capital - $1,737,000
O&M - $9,OOOjyr for 30 years
Total Present Worth - $1,875,000
.
.
The following major ARARs and TBCs are cited for Alternative 3:
ARARs
1242.rdr
.
This alternative complies with relevant and appropriate RCRA Corrective
Action requirements for the lower lagoon soils. Since the upper lagoons also
have a release, this alternative does not comply with Corrective Action
requirements for the upper lagoon soils. The groundwater requirements will
be addressed in the second operable unit.
.
This alternative complies with land disposal restrictions.
.
RCRA and equivalent state regulations for disposal of a hazardous waste in
a landfill are relevant and appropriate but not applicable since disposal by
definition has not occurred (i.e., taking the contaminated soils out of the area
of contamination). This alternative will not comply with the minimum
technical requirements calling for installation of two or more liners and a
leachate collection system since the upper lagoon soils remain in place. This
alternative will comply with RCRA capping requirements.
.
Alternative 3 will comply with the State and National Ambient Air Quality
Standards (NAAQS) that apply for any remedial activities, such as excavation,
that result in airborne discharges from the site. .
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TBCs
.
In the absence of chemical-specific ARARs, cleanup criteria were developed
from the TBCs. In the lower lagoon area, these criteria are met.. In the
upper lagoon area, the criteria are not met, however, in this area the
infiltration of rainfall to soils with explosives concentrations greater than the
health-based cleanup criteria is greatly reduced.
2.8.4 Alternative 4: On-Site Comoostine and On-Site Disposal of Upper and [.()wer
Laeoon Area Soils
Alternative 4 involves removal of the sources of contamination in the upper and lower
lagoon areas at the SV ADA Washout Lagoon site, on-site composting of these affected soils,
and placement of the treated soils/compost in a unifilliocated in an area designated by
SV ADA personnel. For the purposes of this ROD; the word "unifill" is being used to
describe the area set aside for land disposal of only the treated SV ADA Washout Lagoon
soils. The criteria that will be considered in designating the area of the unifill are:
hydrogeology of the site, characteristics of the on-site soil, environmental factors,
climatological conditions, and socioeconomic factors. The volume of soils treated is
approximately 18,230 yd3. The size of the composting facility is designed to handle
approximately 18,000 yd3 in 5 years with 12 compost pads operating at one time.
In this Alternative, it is uncertain whether the treated soils can meet all health-based
remediation criteria. In past studies, composting has shown significant degradation (79%
to 99.6%) of explosives compounds. However, these percentages may not be high enough
to achieve the health-based remediation criteria or lower treatment standards that would
be set for the excavated soils. When treatment is complete, the final compost is disposed
in an on-site unifill that complies with state regulations for a putrescible waste landfill. This
includes a single liner, a leachate drainage and collection system, gas monitoring devices,
and a final low permeability cover. The total quantity of compost materials (treated soils
and amendments such as wood chips, manure, alfalfa, etc.) is expected to be approximately
91,150 yd3, which is five times the amount of soils treated.
It is expected that implementation of Alternative 4 would result in a reduction of the current
and potential future health risks presented in Table 4. The compost materials are expected
] 02S.cad
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-"
to be nontoxic and not hazardous. In addition, these materials will be placed in a lined and
covered unifill that complies with state landfill requirements.
The risks to workers aerating the compost primarily involve dust and volatile emissions (e.g.,
methane). Dust suppression measures such as wetting the piles will be taken to control
airborne particulate matter and an on-site air monitoring program will be conducted for
organic vapor emissions.
This alternative can be readily implemented as excavation, composting, and unifill
construction utilizes proven technologies for conventional applications. It is estimated that
composting of all of the affected soils will take 5 to 7 years. This estimate is based on
reaction kinetics from previous studies. When composting is implemented on the SV ADA
soils, reaction kinetics may differ due to variability in soil type and test conditions from one
study to the next. As a result, a treatability study must be conducted prior to
implementation to determine the remediation levels of explosive compounds that can be
achieved and the length of time required to achieve these levels. In addition, the winters
in Illinois can be harsh. Although composting operations can continue in the winter, it is
expected that degradation rates may decrease due to the loss of heat from the piles. If the
degradation rate slows significantly, then the treatment period will likewise increase.
The costs for Alternative 4 are as follows:
.
Capital - $6,904,000
.
O&M - $907,OOO/yr for first 6 years
$11,400jyr for remaining 24 years
$6,200/yr for 5 years after remediation
.
Total Present Worth $11,645,000
The following major ARARs and TBCs are cited for Alternative 4:
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ARARs
TBCs
1242.rdr
.
This alternative complies with RCRA Corrective Action requirements for soils
only. The groundwater requirements will be addressed in the second operable
unit.
.
This alternative complies with land disposal restrictions.
.
This alternative complies with relevant and appropriate RCRA and state
requirements for treatment, storage, and disposal (TSD) facilities. These
requirements include but are not limited to waste piles. The treatment of
explosives-contaminated sediments by aerated static pile composting involves
piling up the compost mixtures and aerating the compost pile. Therefore,.
from a regulatory standpoint, a composting operation may be considered as
a form of waste pile as defined by RCRA and requires a double liner and
leachate collection system.
.
The compost may potentially be considered putrescible waste as it is defined
by the state as "a solid waste that contains organic matter capable of being
decomposed by microorganisms so as to cause a malodor, gases, or other
offensive conditions, or which is capable of providing food for birds and
vectors." As a result, this alternative complies with applicable state
putrescible waste landfill requirements in addition to RCRA Subtitle D
requirements.
.
Alternative 4 will comply with the state and NMQS that apply for any
remedial activities, such as excavation and aeration of piles, that result in any
airborne discharges from the site.
.
In the absence of chemical-specific ARARs, the TBCs have been used to set
protective remedial action criteria. It is uncertain whether the treated soils
can meet all the health-based remediation criteria.
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2.8.5 Alternative 5: On-Site Solvent Extraction and On-Site Disposal of Upper and Lower
La~oon Area Soils
Alternative 5 involves removal of the sources of contamination in the upper and lower
lagoon areas at the SV ADA Washout Lagoon site, on-site solvent extraction of these
affected soils, and placement of the treated soils in a unifilliocated in an area designated
by SV ADA personnel. The volume of explosives-contaminated soils to be treated is
approximately 18,230 yd3 (24,620 tons).
For this alternative, a batch countercurrent process utilizing a 90% solvent ratio is
evaluated. The solvent extraction unit has been sized for a processing rate of 64 tons per
day.
In this alternative, it is uncertain whether the treated soils can meet all health-based
remediation criteria or any lower treatment standard. Previous testing has shown that
solvent extraction can significantly reduce the explosive compound concentrations in soil.
With a 90% solvent (acetone) ratio, concentrations of TNT in soil have been reduced from
20,000; 730; and 870,000 mgjkg to 7; 6; and 17 mgjkg, respectively. If TNT is an
appropriate indicator compound, solvent extraction shows potential in reducing all of the
explosives compounds to the health-based remediation criteria. However, it is noted that
the health-based remediation criteria are excavation cleanup levels. Treatment standards
set by federal and state agencies will likely be lower than the remediation criteria. The
ability of solvent extraction to achieve these lower levels in the treated soils must be
demonstrated by additional testing. When treatment is complete, the soils will be disposed
in an on-site unifill that complies with state inert landfill regulations. This includes post
closure care and a minimum 3 feet of soil cover. The spent solvent or concentrated
wastestream containing explosives compounds will be transported off-site for incineration.
For solvent extraction the main short-term risk occurs during solvent handling operations
as the solvent is usually relatively volatile. Workers will be adequately protected and the
work space sufficiently ventilated so that exposure limits for the specified solvent are not
exceeded.
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'"
It is expected that implementation of Alternative 5 would result in a reduction of the current
and potential future health risks presented in Table 4. If the treated soils are adequately
dried such that residual acetone is removed and will no longer cause explosives compounds
to leach from the soils, then it is expected in the long term, that this alternative. will be
protective. However, there is a limited risk in the leaching of residual concentrations of
explosive compounds if the acetone is not adequately removed, and acts as a co-solvent with
water. In any case, treated soils will be disposed of in a unifill that complies with state
requirements.
If leachate testing indicates that a contaminated leachate is formed from the treated soils,
then the soils will be disposed of in a chemical waste landfill in compliance with state
requirements. The chemical waste landfill would include a liner and a low permeability
cover as discussed in Alternative 4 for putrescible waste landfills. Chemical and putrescible
waste landfills have the same design and operation requirements.
This alternative can be readily implemented as excavation, solvent extraction, and unifill
construction utilize proven technologies for conventional applications. It is estimated that
solvent extraction of all of the affected soils will take 1 to 3 years. This estimate is based
on the WESTON design for a batch process that treats 64,000 lb of soil per 8-hour cycle at
tWo cycles per day.
Due to variability in soil type and test conditions from one study to the next, a treatability
study must be conducted on the SV ADA Washout Lagoon soils to determine whether the
proposed conceptual design is appropriate and to determine whether solvent extraction will
demonstrate adequate removal efficiencies. In addition, a number of solvent ratios may be
tested to select the lowest ratio or amount of solvent that is required for a given removal
efficiency.
Finally, prior to transport and disposal of the concentrated wastestream. preacceptance
approval from the designated RCRA facility will be required. Due to limited capacity
nationwide, receiving approval may be difficult. In addition, transport of this explosives
concentrated wastestream must proceed extremely cautiously.
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" .
The costs for Alternative 5 are as follows:
.
.
.
Capital - $4,817,000 .
O&M - $2,120,OOOjyr for first 2 years
11,400 for remai,ning 2 years
Total Present Worth - $8,778,000
The following major ARARs and TBCs are cited for Alternative 5:
ARARs
1242.rdr
.
This alternative complies with RCRA Corrective Action requirements only for
the lagoon soils. Since all soils with concentrations of explosives above the
health-based remediation criteria will be removed and treated and because
a separate groundwater investigation and remediation program will occur at
the SV ADA installation, a groundwater monitoring program is not included
in this alternative. In addition, groundwater requirements will be addressed
in a second operable unit.
This alternative complies with land disposal restrictions.
.
This alternative complies with relevant and appropriate RCRA and state
requirements for TSD facilities. These requirements include, but are not
limited to, miscellaneous units. Since there are no regulations that directly
address solvent extraction units, the requirements for miscellaneous units are
relevant and appropriate.
.
The treated soil may be considered an inert waste as it is defined as "...any
solid waste that will not decompose biologically, burn, serve as food for
vectors, form a gas, cauSe an odor, or form a contaminated leachate."
However, if residual solvent remains in the soils at significant levels, then the
treated soils may be considered a chemical waste. Chemical waste is defined
as "ma non-putrescible solid whose characteristics are such that any
contaminated leachate is expected to be formed through chemical or physical
processes, rather than biological processes, and no gas is expected to be
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TBCs
. .
.
"
formed as a result." If acetone, which is totally soluble in water, remains in
the soils so as to facilitate the continued leaching of explosives compounds,
then it is expected that the treated soils would be considered a chemical
waste. In this alternative, it is assumed that acetone will be sufficiently
removed from the treated soils such that a contaminated leachate. is not
formed during leachate testing. This alternative complies with state
requirements for inert waste landfills in addition to RCRA Subtitle D
requirements.
.
Alternative 5 will comply with the state and NAAQS that apply for any
remedial activities, such as excavation, that result in any airborne discharges
from the site.
In the absence of chemical-specific ARARs, the TBCs have been used to set
protective remedial action criteria. It is uncertain whether the treated soils
can meet all the health-based remediation criteria.
.
For the off-site disposal of the concentrate wastestream, the U.S. EP A Interim
Policy for Planning and Implementing CERCLA Off-Site Response Actions
may be a TBC for this alternative. This federal policy requires consideration
of treatment, recycling, or reuse for on-site and off-site actions and established
procedures that U.S. EP A Regions must use in selecting an off-site RCRA
facility for management of hazardous substances. Where off-site disposal is
used, the policy states that the disposal facility must be in compliance with the
applicable technical requirements of RCRA.
2.8.6 Alternative 6: On-Site Thermal Treatment and On-Site DisDosal of UDtJer and
--
Lower Laeoon Area Soils
Alternative 6 involves removal of the sources of contamination in the upper and lower
lagoon areas at the SV ADA Washout Lagoon site, on-site thermal treatment of these
affected soils, and placement of the treated soils in a unifilliocated in an area designated
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I),' ,
by SV ADA personnel. The volume of soils to be treated is approximately 18,230 yd3
(24,620 tons). The size of the thermal treatment unit is designed to handle 20 tons per
hour.
In this alternative, it is expected that all of the treated soils can meet all the health-based
remediation criteria. It is also anticipated that the treated soils and fly ash from thermal
treatment will meet Toxicity Characteristic Leaching Procedure (TCLP) extract criteria for
land disposal. If the treated material does not meet the criteria, it can be stabilized prior
to disposal. The treated soils and fly ash will be placed in an on-site unifill. This unifill will
include a compacted clean soil cover.
It is expected that implementation of Alternative 6 would result in a significant reduction
of the current and potential future health risks presented in Table 4. In the long term, this
alternative is protective since, based on previous successful demonstrations, TNT and
exp~osives contamination above the health-based remediation criteria will be destroyed and
there will be no process by-products or residual solvent in the soils. By incineration of the
e"1'losives compounds in these soils, the threat of exposure to these contaminants, both
directly and indirectly, is reduced. Since the contaminants are destroyed/deactivated,
toxicity and mobility are virtually eliminated.
The options available for on-site thermal treatment include mobile or transportable units
that are currently marketed by a number of vendors. Rotary kilns are offered by vendors
such as ENSCO Environmental Services, EPA-ORD, IT Corporation, and Weston Services
Inc., (WESTON). The infrared incinerator is offered by ECOV A, and the circulating bed
combustor is offered by Ogden Environmental Systems. It is anticipated that soils to be
treated as part of this alternative may require some materials handling prior to being fed
into the incinerator system so that large objects are removed or reduced in size. For the
rotary kiln, top size of feed material can be as large as 6 inches, though 2 inches is optimal.
Both the infrared and circulating bed combustor have a lower top size of approximately 1
to 2 inches, and therefore, would likely require more extensive material pretreatment.
Rotary kiln incineration is the only thermal technology that has been submitted for review
and has been approved by the Depanment of Defense Explosives Safety Board (DDESB).
The trial bum for the explosives compounds will determine the destruction and removal
efficiency for explosive constituents and demonstrate the performance of the air emissions
102S.cad
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.
'..>
controls. Effluent streams from the incinerator include gaseous emissions and a treated soil
and fly ash product. Use of a scrubbing system to control hydrochloric acid (HCI) emissions
is not anticipated since the waste feed material does not contain significant chlorine content.
However, if a scrubber should be needed, it can be readily added to the incinerator so that
the off-gases can be treated. Baghouses will likely be required to control particulates
resulting from incineration. Treated soils or fly ash generated during the trial burn will be
tested to verify that the hazardous component of the soils has been removed.
The costs for Alternative 6 are as follows:
.
Capital
Rotary Kiln: $10,230,000
Infrared: $15,586,000
Fluidized Bed: $11,475,000
. .
O&M - $11,4oojyr for 2 years
.
Total Present Worth
Rotary Kiln: $10,251,000
Infrared: $15,607,000
Fluidized Bed: $11,496,000
The following major ARARs and TBCs are cited for Alternative 6:
ARARs
.
With the exception of groundwater monitoring, this alternative complies with
RCRA Corrective Action for contaminated soils. Since all soils with
concentrations of explosives above the health-based remediation criteria will
be removed and treated and because a separate groundwater invqtigation and
remediation program will occur at the SV ADA installation, a groundwater
monitoring program is not included in this alternative. In addition, the RCRA
Corrective Action groundwater requirements will be addressed in a
subsequent operable unit.
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.
"
TBCs
1242.rdr
.
This alternative complies with land disposal restrictions (40 CFR Part 268).
.
This alternative complies with relevant and appropriate (RCRA) and state
requirements for hazardous waste incinerators (40 CFR Part 264, Subpart 0).
.
As in Alternative 5, the treated soils would likely be classified by the state as
an inert waste. One of the state requirements for solid inert waste landfills
includes 3 feet of soil cover that can support vegetation (35 lAC 811.204). In
this alternative, an exemption from the 3 feet of soil cover may be in order
such that the thickness of the cover may be less than 3 feet (6 inches will be
sufficient to support vegetation). The 3 feet of soil cover would be
appropriate for inert and irregularly-shaped wastes such as bricks, concrete,
etc. so that a uniform surface can be maintained. However, in this
alternative, the topsoil is covering treated soil that meets all the treatment
criteria and the TCLP criteria. This cover would only need to serve as a
means to establish vegetation so that erosion would not occur or is minimized.
If any treated soils fail the TCLP criteria, they will be stabilized. In this
instance, the stabilized materials will be segregated and disposed in
compliance with RCRA Subtitle D requirements. This alternative will comply
with state cover requirements for solid inert waste landfills. During the
remedial design/remedial action (RD/RA) phase of work at the SV ADA
Washout Lagoon Area, the State will make a decision on any exemption from
the state regulations that is requested.
.
Alternative 6 will comply with the state and NAAQS that apply for any
remedial activities, such as excavation and incineration, that result in any
airborne discharges from the site.
.
In the absence of chemical-specific ARARs, the TBCs have been used to set
protective remedial action criteria. It is expected that in this alternative the
treated soils can meet all health-based remediation criteria.
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.
'0
2.8.7 Alternative 7: OfT-Site ThennaJ Treatment. and OfT-Site Disposal of Upper and
Lower Laloon Area Soils
Alternative 7 involves removal of the sources of contamination in the upper and lower
lagoon areas at the SV ADA Washout Lagoon site and off-site thermal treatment and
disposal of these affected soils at a RCRA-approved facility. The volume of soils to be
treated is approximately 18,230 yd3. Due to limited capacity, it may be difficult to gain
acceptance of this volume of soils at an off-site RCRA facility.
In this alternative, it is expected that all of the treated soils can meet the health-based
remediation criteria. By incineration of the explosives compounds in these soils, the threat
of exposure to these contaminants, both directly and indirectly, is reduced. Since the
contaminants are deactivated, toxicity and mobility are virtually eliminated.
There is a short-term risk associated with the transportation of contaminated soils to the
treatment facility. This risk would be caused primarily by inadequate covering of the soils
or a vehicular accident that could result in exposure of the surrounding community and
environment to the contaminants. To address these concerns, soils will be adequately
secured with tarps or other covers/liners during staging and transportation to the disposal
site. In addition, accepted defensive driving practices will be used and there will be strict
compliance with the Illinois Commercial Vehicle Code and all state and federal hazardous
materials and waste transportation regulations so that the risk of contaminant release is
minimized.
A limited number of stationary RCRA-permitted treatment and disposal facilities are
located in the United States. The closest facility is the Chemical Waste Management rotary
kiln incinerator in Chicago, Illinois. However, this facility is currently out of compliance
with the CERCLA Off-Site Disposal Policy. Pre acceptance approvals will be required.
before transport to any off-site facility. As noted, due to the limited capacity, it may be
difficult to gain acceptance at a facility. For transportation of the soils. it will be necessary
to obtain federal and state hazardous waste manifests.
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The costs for Alternative 7 are as follows:
.
Capital - $24,281,000
O&M - $11,4oojyr for 2 years
Total Present Worth - $24,302,000
.
.
The following major ARARs and TBCs are cited for Alternative 7:
ARARs
~
1242.rdr
.
With the exception of groundwater monitoring, this alternative complies with
RCRA Corrective Action for contaminated soils. Since all soils with
concentrations of explosives above the health-based remediation criteria will
be removed and treated and because a separate groundwater investigation and
remediation program will occur at the SV ADA installation, a groundwater
monitoring program is not included in this alternative. In addition, the RCRA
Corrective Action groundwater requirements will be addressed in a
subsequent operable unit.
.
This alternative complies with land disposal restrictions (40 CFR Part 268).
.
Alternative 7 will comply with the state and NAAQS that apply for any
remedial activities, such as excavation, that result in any airborne discharges
from the site~
.
In the absence of chemical-specific ARARS, the TBCs have been used to set
protective remedial action criteria. It is expected in this alternative the
treated soils can meet all health-based criteria.
.
The U.S. EPA Interim Policy for Planning and Implementing CERCLA Off-
Site Response Actions may be a TBC for this alternative. This federal policy
requires consideration of treatment, recycling, or reuse for on-site and off-site
actions and established procedures that U.S. EPA Regions must use in
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selecting an off-site RCRA facility for management of hazardous substances.
Where off-site disposal is used, the policy states that the disposal facility must
be in compliance with the applicable technical requirements of RCRA.
2.9
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
This section summarizes the relative performance of the alternatives by highlighting the key
differences among the alternatives in relation to the nine evaluation criteria which are
categorized as: (1) Threshold Criteria; (2) Primary Balancing Criteria; and (3) Modifying
Criteria. Each of these terms is described as follows:
.
Threshold Criteria
Overall protection of human health and the environment addresses
whether a remedy provides adequate protection of human health and
the environment and describes how risks posed through each exposure
pathway are eliminated, reduced or controlled through treatment and
engineering controls. The selected remedy must meet this criteria.
Compliance with applicable or relevant and appropriate requirements
(ARARs) addresses whether a remedy will meet federal and state
environmental laws and/or justifies a waiver from such requirements.
The selected remedy must meet this criteria.
.
Primary Balancin~ Criteria
Long-term etTectiveness and permanence refers to expected residual
risk and the ability of a remedy to maintain reliable protection of
human health and the environment over time, once cleanup goals have
been met. .
Reduction of toxicity, mobility, and volume through treatment is the
anticipated performance of the treatment technologies a remedy may
employ.
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. .
Short.tenn effectiveness addresses the period of time needed to
achieve protection and any adverse impacts on human health and the
environment that may be posed, until cleanup goals are achieved.
Implementability is the technical and administrative feasibility of a
remedy, including the availability of materials and services needed to
implement a particular option.
Cost includes estimated capital and operation and maintenance
(O&M) costs, also expressed as net present-worth cost.
Modifyini: Criteria
Support Agency (EPA/IEPA) acceptance reflects aspects of the
preferred alternative and other alternatives the EP A/IEP A favor or
object to, and any specific comments regarding federal and state
ARARs or the proposed use of waivers.
Community acceptance summarizes the public's general response to
the alternatives described in the proposed plan and in the RI/FS,
based on public comments received. The assessment of support agency
and community acceptance will not be complete until after the public
comment period is over.
2.9.1 Threshold Criteria
2.9.1.1 Overall Protectiveness of Human Health and the Environment
Alternative 1 is not protective of human health and the environment. Alternative 2 is
slightly more protective of human health than Alternative 1 because of tbe usage restriction
and fence installation, however it is not protective of the environment and does not reduce
environmental risks. Alternatives' 3 through 7 are protective of human health and the
environment but at varying degrees. Alternative 3 is protective because virtually all of the
subject soils are contained under a c~p. In any case, Alternatives 1 through 3 leave a source
for potential future groundwater contamination. Alternative 4 involves transporting the
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,,"
contaminated soil out of the area of contamination to a large treatment area away from the
lagoons. There is the potential to contaminate "clean areas" by on-site transport.
Alternatives 4 and 5 are both more protective than Alternative 3 because virtually all of
the explosives contamination above the remediation criteria is removed, treated, and then
disposed of in a unifill. The selected remedy, Alternative 6, is the most protective
alternative because virtually all of explosives contamination above the remediation criteria
will be removed and thermally treated, and no process by-products or residual solvent will
remain in the soils. Alternative 7 is slightly less protective as Alternative 6 due to
transportation risks.
2.9.1.2 Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
Alternatives 1 and 2 do not comply with ARARs. Alternative 3 does not comply with
RCRA requirements for landfills, however, it does comply with RCRA specifications for
landfill caps. Alternatives 4 through 7, including selected Alternative 6, will comply with all
applicable, relevant and appropriate requirements. In particular, Alternative 6 will comply
with all state and federal hazardous waste incinerator regulations regarding operations, air
emissions, and closure. Alternatives 3 through 7 comply with land disposal restrictions.
In the absence of ARARs that specifically address explosives compounds in soils, the
remediation criteria which have been developed from published health-based data are
considered in each alternative. In Alternatives 1, 2, and 3, none of the remediation criteria
will be achieved, although Alternative 3 is more protective of human health than
Alternatives 1 and 2 due to the presence of a cap over untreated soils. Alternatives 4 and
5 are expected to show significant reductions in explosives compounds concentrations, but
whether they can achieve the required cleanup or lower treatment levels remains to be
determined. In Alternatives 6 and 7, all soils with concentrations greater than the
remediation criteria will be thermally treated and it is expected that all of the required
cleanup and lower treatment levels can be achieved. In particular, in Alternative 6, the
treatment level for TNT is 1 microgram per gram (ugjg) which is significantly less than the
remediation criteria of 21.1 mgjkg (equivalent to 21.1 ugjg). For all treated soils, in order
to eliminate the requirement of a RCRA cap, the treated soils would have to be below
health-based concentrations. Otherwise, a RCRA cap would be required~ Any soils that
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. .
require stabilization to comply with TCLP levels will be disposed in compliance with RCRA
Subtitle D requirements.
2.9.2 Primary Balancine Criteria
2.9.2.1 Long-Term EfTectiveness and Permanence
In Alternative 1 and 2, long-term risk reductions may prove to be minimal. In Alternative
3, soils that exceed the remedial action criteria serve as a remaining source of risk to
potential receptors. However, capping will reduce this remaining source of risk to less than
estimated current and future values. Long-term management of the cap will be required.
In any event, Alternatives 1 through 3 leave a source for potential future groundwater
contamination. .
Alternatives 4 through 7 involve treatment of the explosives-contaminated soils. Each of
these-alternatives is expected to result in significant reductions of the contaminants, thereby
reducing the estimated current and potential future risks due to exposure. The final risks
of current and future exposure depend on the effectiveness of each technology and the
percent degradation, removal, or des~ruction that can be achieved.
The compost materials in Alternative 4 serve as a remaining source of risk, however, they
are expected to be nontoxic or exhibit low toxicity and are not thought to be hazardous. In
Alternative 5, there is a limited risk in the leaching of residual concentrations of explosives
compounds if the solvent is not adequately removed from treated soils and acts as a co-
solvent with water.
Selected Alternative 6 is more protective than 1 through 5 because virtually all TNT and
explosives contamination above the health-based remediation criteria will be destroyed and
there will be no process by-products or residual solvent in the soils. There is a limited risk
in the leaching of naturally-occurring metals from treated soils; however, this is not expected
for the SV ADA soils. If the treated soils do not meet the TCLP criteria for metals, they
will be stabilized prior to disposal. For this alternative, stabilization is a fixative treatment
process designed to limit the solubility or toxicity of metals that may be contained in the
incinerated materials. Minimal or no long-term management is required once the thermal
treatment unit is removed from the site. Revegetation of the site would be required.
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In Alternative 7, the only management for long-term cOIl5ideration is revegetation of the
site.
2.9.2.2 Reduction of Toxicity, Mobility, and Volume of Contaminants
For Alternatives 1 and 2, it appears that toxicity, mobility, and volume of contaminants will
remain at their current values for an extended period of time. These alternatives do not
satisfy the statutory preference for treatment as a principal element of an alternative.
In Alternative 3, capping the upper lagoon soils reduces contaminant mobility, but it does
not reduce toxicity or volume. In addition, it does not meet the statutory preference for
treatment. The volume of soils capped is expected to be approximately 18,230 yd3. .
In Alternative 4, contaminant volume, mobility, and toxicity are reduced by degradation.
The volume of residuals to be disposed of is approximately 91,150 yd3, which is significantly
larger than the original volume of soils to be treated (18,230 yd3). This alternative satisfies
the statutory preference for treatment as a principal element.
In Alternative 5, contaminant volume, mobility, and toxicity are reduced by their removal
and off-site treatment. (The solvent extraction process is wholly conducted on-site. It
involves extracting contaminants from the soils and transferring them into a concentrated
liquid wastestream. This liquid wastestream containing the explosives compounds must be
sent off-site for incineration.) However, if any residual solvent is present in the treated
soils, it may increase the mobility of the residual contaminants. The volume of treated soils
to be disposed of is approximately 18,230 yd3. In addition, the wastestream to be treated
off-site is estimated at 46,000 gallons. This alternative satisfies the statutory preference for
treatment as a principal part of an alternative. .
Alternatives 6 and 7 both virtually eliminate contaminant toxicity, mobility, and volume by
incinerating all of the subject soils. If the treated soils do not meet the TCLP criteria for
naturally-occurring metals, they will be stabilized prior to disposal. The volume to be
disposed is approximately 18,230 yd3. These alternatives satisfy the statutory preference for
treatment as a principal part of an alternative.
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2.9.2.3 Short-Term Effectiveness
In Alternatives 1 and 2, the current risks to the community associated with Pathway 1
remain the same and are not mitigated. One of the short-term risks to on-site workers
during remediation in Alternatives 3 through 7 involves working around potential
unexploded ordnance (UXOs) and explosives. This risk is mitigated by sweeping for UXOs
prior to excavation. Any identified UXO will be removed by UXO personnel. Areas that
are expected to contain high explosives concentrations (Le., greater than 10 percent total
explosives) are typically characterized by a pink discoloration. These areas will be manually
excavated using sparkproof shovels and buckets and dispersed over the entire area to be
excavated. The soils will be wetted prior to handling to minimize the hazard of working
with explosives compounds. All personnel will be evacuated from the work area so that all
of the contaminated soils can be remotely blended using an extended arm backhoe. The
blending will stop when all discolored material has been mixed in, based on visual
observation, and samples indicate that blended soil concentrations are less than 10%
explosives by weight. In Alternatives 3 through 7, dust suppression measures to minimize
any potential dust generation and air monitoring will be conducted for any excavation and
construction activities.
For Alternative 6, the main shon-term risk is from the thermal unit (incinerator) air.
emissions. The emissions from the unit will be controlled by an off-gas treatment system.
Explosives are readily destroyed during incineration and, therefore, any potential emissions
of explosives would be minimal.
The expected time frame for implementation of each alternative is as follows:
. Alternative 1: 0 month
. Alternative 2: 1 month
. Alternative 3: 8 to 14 months
. Alternative 4: 5 to 7 years
. Alternative 5: 1 to 3 years
. Alternative 6: 10 to 14 months
. Alternative 7:. 10 to 14 months
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Implementation time for Alternative 7 depends on immediate approval and acceptance of
the excavated soils at an off-site facility. This situation is undefined because of limited
capacity at commercial facilities. It could be months or years before the materials would
be transported off-site.
2.9.2.4 Implementability
All of the alternatives can be readily implemented. No construction activities are required
under the no action alternative. Alternative 2 involves minimal activities and may take 1
to 2 months to implement. Excavation of the upper and lower lagoon areas is not expected
to present any technical difficulties. Installation of a cap in Alternative 3 involves the use
of common construction techniques. Implementation of Alternative 3 may take to 8 to 14
months. A treatability study would be required for implementation of Alternatives 4 or 5
to determine effectiveness and optimum process parameters. Alternative 4 may take 5 to
7 years to implement and Alternative 5, 1 to 3 years. However, in Alternative 5, it may be
difficult to obtain pre acceptance approvals for treatment of the concentrated wastestream
at an off-site treatment facility due to limited capacity. In addition, the facility accepting
the concentrated waste stream must be in compliance with the CERCLA Off-Site Disposal
Policy. All of this may increase implementation time. Altogether, for anyon-site treatment
alternative, such as Alternatives 4 through 6, the technology to be implemented would be
subject to numerous technical reviews by the appropriate federal and state agencies to
ensure compliance with the substantive requirements of any relevant operating permits.
A number of vendors are available for implementation Of on-site thermal treatment
technologies associated with Alternative 6. These technologies include rotary kiln
incineration, infrared incineration, and circulating bed combustion. The infrared and
circulating bed processes are certainly viable but exhibit some drawbacks when compared
to rotary kiln .incineration. Rotary kilns have a thoroughly tested and well documented
history of successful performance on hazardous waste treatment, including the treatment of
explosives compounds in soils. Although the other two thermal treatment technologies have
demonstrated successful performance for hazardous waste treatment, their use is not as
widespread and as accepted, especially in the treatment of explosives contaminants. Rotary
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kilns can accept a variety of wastes with little pretreatment since the maximum soil particle
size is 6 inches. The infrared and circulating bed processes are more restrictive and would
require more pretreatment of waste materials since the maximum size for these processes
is approximately 1 to 2 inches. In addition, only rotary kiln incineration has been submitted
for review and has been approved by the DDESB for treatment of explosives-contaminated
soils. Alternative 6 is expected to take 10 to 14 months to implement.
For Alternative 7 actual remediation activities are expected to take 10 to 14 months to
implement, however, implementability would depend on acceptance of contaminated soils
at a R(:RA treatment and disposal facility. Due to potential limited capacity, this
acceptance may be difficult to obtain and there may be a significant waiting period if the
soils are accepted. The closest incineration facility is in Chicago, Illinois, and this facility
is currently out of compliance with the CERCLA Off-Site Disposal Po~icy. State and federal
hazardous waste manifest regulations would be applicable to transportation of contaminated
soils to the facility.
2.9.2.5
Cost
The estimated capital, operation and maintenance (O&M), O&M present worth, and total
present worth costs for each remedial alternative are as follows:
.
Alternative 1:
No costs associated
.
Alternative 2:
Capital - $233,000
O&M - $3,000 for first 2 years
$2,500 for remaining 28 years
O&M Present Worth - $38,000
Total Present worth - $271,000
.
Alternative 3:
Capital - $1,737,000
O&M - $9,000 for 30 years
O&M Present Worth - $138,350
Total Present Worth - $1,875,000
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Alternative 4:
.
Alternative 5:
.
Alternative 6:
.
Alternative 7:
2.9.3 ~
2.9.3.1 EPA/IEPA Acceptance
';t ,-)-
Capital - $6,904,000
O&M - $907,000 for first 6 years
$11,400 for remaining 24 years
$6,200 for 5 years after remediation
O&M Present Worth - $4,741,000
Total Present Worth - $11,645,000
Capital - $4,817,000
O&M - $2,120,000 for first 2 years
$11,400 for remaining 2 years
O&M Present Worth - $3,961,100
Total Present Worth - $8,778,000
Capital - Rotary Kiln: $10,230,000
Infrared: $15,586,000
Fluidized Bed - $11,475,000
O&M - $11,400 for 2 years
O&M Present Worth - $21,200
Total Present Worth - Rotary Kiln: $10,251,000
Infrared: $15,607,000
Fluidized Bed: $11,496,000
Capital - $24,281,000
O&M - $11,400 for 2 years
O&M Present Worth - $21,200
Total Present Worth - $24,302,000
EPA and IEPA along with the U.S. Army have concurred with the choice of Alternative 6.
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2.9.3.2 Community Acceptance
Public comments on the selected remedial action were presented at the public meeting on
22 January 1992. No other comments were received during the public comment period
which extended from 6 January to 6 February 1992.
In general, the public has responded favorably to the selection of Alternative 6. The
primary concerns raised at the public meeting involved incinerator operations and emissions,
dust generated, level of noise produced, test bum procedures and parameters, and
protection of human health and the environment. These concerns were addressed at the
public meeting. A summary of significant public comments and Army jEP A responses is
presented in Section 3 of this ROD, the Responsiveness Summary.
2.10
SELECfED REMEDY
The selected remedy to clean up the soil contamination associated with the Washout Lagoon
Area is Alternative 6: On-Site Thermal Treatment (Rotary Kiln Incineration) and On-Site
Disposal of Upper and Lower Lagoon Area Soils with placement of treated soils in a unifill
(Le., the upper lagoon area). Treated soils that fail any of the hazardous waste
characteristic test criteria such as ignitability, corrosivity, reactivity, or toxicity (40 CFR 261
and 35 lAC 721) will be treated until they no longer possess any of the characteristics of
hazardous waste. In addressing toxicity, treated soils that fail the 1 ugj g TNT treatment
standard will be reprocessed through the incinerator. Treated soils that fail the TCLP
testing for metals will be stabilized prior to disposal in compliance with RCRA Subtitle D
requirements. Previous testing of incinerated soils conducted under a past investigation at
the facility indicates that these soils are not expected to be considered ignitable, corrosive,
or reactive. This alternative was chosen because it is the most protective of human health
and the environment, complies with ARARs,and is economically feasible.
Based upon the CERCLA requirements, the detailed analysis of the alternatives, and public
comments; the U.S. EPA, in consultation with IEPA and the U.S. Army has determined that
Alternative 6 is the most appropriate remedy for the Washout Lagoon Area Soils Operable
Unit.
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The recommended thermal treatment technology for utilization is rotary kiln incineration.
It is the most widely used and proven method for thermal treatment. Rotary kiln
incineration has been successfully used at other sites for treatment of explosives -
contaminated soils. It is the only technology that has been submitted to and approved by
the DDESB for treatment of explosives contaminated soils. This alternative could be
implemented in 10 to 14 months with an actual bum time of 5 months.
As noted previously, the estimated capital cost for rotary kiln incineration is $10,230,000.
The estimated annual O&M cost is $11,400 and is extended to 2 years. The estimated total
present worth cost of rotary kiln incineration is $10,251,000.
The estimated amount of soil to be removed and treated is 12,230 yd3 (16,500 tons) to an
approximate depth of 7 feet from the lower lagoon area and 6,000 yd3 (8,095 tons) to an
approximate depth of 4 feet from the upper lagoon area for a total of 18,230 yd3 (24,600
tons). The final depths and volumes will be based on verification sampling to determine
that cleanup levels have been achieved. The lower lagoons will be backfilled with clean soil.
The treated soils will be backfilled in the upper lagoon area and covered with clean native
soils. The backfill of the treated soils and native soils will form a gently sloping hill.
The major components of the selected remedy for the Washout Lagoon Area Soils Operable
Unit include the following: .
.
Pipe removal.
.
Excavation of contaminated soils in the following areas:
Drain trough.
Lower lagoons.
Overflow ditch.
Upper lagoons.
Around the removed underground pipe.
.
Verification sampling to document cleanup levels.
.
On-site thermal treatment by rotary kiln incineration of the contaminated soils.
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.
.
On-site disposal of treated soils.
.
Decanting and treatment of standing water in the lagoons (if needed).
. Any affected wetlands will be restored. One option to restore wetlands may be
establishing original contours.
.
Perimeter air monitoring to ensure that site activities do not impact areas beyond the
area of contamination.
2.10.1 Remediation Goals
The selected remedy will meet the following remediation goals:
. The Washout Lagoon Area Soils Operable Unit will be excavated to the cleanup
criteria presented in Table 5. For the residual soils that remain in place, this
corresponds to attainment of a 1 x 10-5 potential carcinogenic risk level for the
dinitrotoluenes and a 1 x 10-6 potential carcinogenic risk level for the remainder of
the compounds listed in Table 5.
. Treatment of tbe excavated soils will be conducted such that they are deactivated,
as required by RCRA A treatment standard of 1 ugj g TNT will be used to
demonstrate deactivation. This treatment criteria is set as a practical, achievable
limit that is well below the 21.1 mgjkg (equivalent to 21.1 ug/g) TNT cleanup level
and is approximately equal to the practical analytical quantitation limit. This will
ensure that the explosives compounds have been sufficiently destroyed and pose no
further risk to human health or the environment.
. The treated soils and fly ash will not possess any of the characteristics of hazardous
waste (40 CFR 261 and 35 lAC 721).
.
Metals - The extract from treated soils and fly ash (from the thermal treatment unit)
will meet TCLP criteria for metals, as required by RCRA (40 CFR 261.24 and 35
lAC 721.124).
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.
Decanted water from the lagoons, groundwater encountered during excavation, and
wastewaters generated during process operations such as decontamination and
rainwater runoff will be treated by sand filtration and/or carbon adsorption to 2
mg/L TNT. The basis for this treatment level is a back-calculation of the water
concentration that would result from the leaching of soils with the cleanup level
concentration of 21.1 ug/g TNT using the soil/water partition coefficient, Kd for
TNT. The following equations were used:
Water Concentration = Soil Concentration
Kd
(1)
Where:
Kd = KocF oc
(2)
Kot' Organic carbon/water partition coefficient
F oc' Fraction organic carbon in soil
In the Dames & Moore RI (1991) log Koc for TNT was given as 2.72 (Koc = 524.8). In the
WESTON 1984 investigation, organic carbon content at the upper lagoons was stated as 2
percent (F oc = 0.02). Calculating for Kd (equation 2) and substituting 21.1 ug/g TNT into
equation 1, a value of 2,000 ug/L (or the equivalent, 2 mg/L) is estimated for the water
concentration. Therefore, since this is the concentration that would be allowed to leach
from the soils, it is also a sufficient treatment level for decanted water from the lagoons,
groundwater encountered during excavation, and wastewaters generated from process
operations. The treated water will be used for on-site dust control, discharged to the lower
lagoon area during backfill with borrow soil to aid soil compaction, discharged to the
backwaters of Crooked Slough, or discharged directly to Crooked Slough.
2.11
STATUTORY DETERMINATIONS
The selected remedy satisfies the requirements under Section 121 of CERCLA to:
.
Protect human health and the environment.
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Comply with ARARs.
.
Be cost-effective.
.
Utilize permanent solutions and alternative treatment technologies or resource
recovery technologies to the maximum extent practicable.
.
Satisfy the preference for treatment as a principal element.
2.11.1 Protection of Human Health and the Environment
The selected remedy, Alternative 6, will reduce risks posed through each current and
potential future pathway through treatment of excavated soils by rotary kiln incineration,
followed by on-site disposal of the treated soils. By deactivation and destruction of the
explosives compounds, adequate protection of human health and the environment is
provided such that the risks will be reduced to within the acceptable 1 x 10-4 to 1 x 10-6
range for carcinogens and a hazard quotient less than 1 for noncarcinogens.
No unacceptable short-term risks or cross-media impacts will be caused by implementation
of the chosen remedy. During the remediation activities, adequate protection will be
provided to the community and the environment by controlling air emissions from the
thermal treatment unit and dust generated during material handling activities. In addition,
workers will be provided with personal protective equipment and air monitoring during all
phases of remediation activities.
2.11.2 Comnliance with ARARs
The State of Illinois hazardous waste regulations are equivalent to federal hazardous waste
regulations (RCRA). For the purpose of discussion, only the federal regulations are cited.
The State of Illinois also has special and solid waste regulations which are discussed in
Subsection 2.11.2.3
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2.11.2.1 Chemical-Specific ARARs
o
t
Under RCRA (40 CFR 261), wastewater treatment sludge from the manufacturing and
processing of explosives is considered a listed waste due to reactivity with an EP A
Hazardous Waste Number of K044. The associated pink/red water from TNT operations
is also considered a listed waste due to reactivity and has an EPA Hazardous Waste
Number of K047. Disposal of materials at the SVADA Washout Lagoon Area occurred
prior to the effective date of RCRA, therefore, the RCRA listed waste and other pertinent
regulations may be considered relevant and appropriate but not directly applicable. In this
ROD, SV ADA Washout Lagoon soils are considered sufficiently similar to K044 or K047 -
listed wastes.
Currently, there are no chemical-specific federal or state regulations that specify action
levels for explosives contaminants in soils. Although TBCs are not considered potential
ARARs, they can be used in the absence of ARARs. TBCs such as reference doses and
potency factors have been used to set protective remedial action criteria for the explosives
compounds at the SV ADA Washout Lagoon Area. In this alternative, it is expected that
the treated soils will meet all health-based remediation criteria if the treatment criteria of
1 ug/g TNT is satisfied. Verification sampling will be conducted to ensure compliance with
these health-based remediation criteria. Residual soils left in the ground in the upper and
lower lagoon areas would have. no concentrations of explosives compounds that are greater
than the health-based criteria.
2.11.2.2 Location-Specific ARARs
A number of location-specific ARARs pertain to implementation of Alternative 6 and are
listed as follows: .
.
In compliance with Federal Executive Order 11990, activities performed in a
wetlands area are required to take actions to minimi7.e the destruction, loss, or
degradation of the wetland. The lower lagoons may lie within or adjacent to wetland
areas; therefore, this ARAR is applicable. In addition, any affected wetlands must
be restored as appropriate. Alternative 6 will be implemented in compliance with
this applicable requirement.
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.
Protection of Floodplains (40 CFR 6, Appendix A) and RCRA (40 CFR 264.18)
require that facilities within a 100-year flood plain be designed to avoid washout.
Alternative 6 will be implemented in compliance with this applicable requirement.
.
Under the Endangered Species Act (16 USC 1531) and State of Illinois Department
of Conservation Administrative Order of 1978, actions must be performed to
conserve the endangered or threatened species located in and around the SV ADA
facility. Activities must not destroy or adversely modify the critical habitat upon
which endangered species depend. Alternative 6 will be implemented in compliance
with this applicable regulation. Prior to conducting remedial activities, a survey of
the subject areas will be conducted to determine whether or not endangered or
threatened species will be affected.
.
Under the Fish and Wildlife Coordination Act (16 USC 661), actions must be taken
to protect fish and wildlife resources affected by site activities. Alternative 6 will be
. implemented in compliance with this applicable regulation.
2.11.2.3 Action-specific ARARs
A number of action-specific ARARs pertain to implementation of Alternative 6 and are
listed as follows:
.
RCRA Corrective Action requirements (40 CFR 264.100 and 40 CFR 264.101) would
not be directly applicable to the lagoons, however they would be relevant and
appropriate. RCRA corrective action requirements are primarily designed to address
operating facilities with a RCRA permit in which a groundwater protection standard
has been set by the Regional Administrator.
The owner or operator must implement a corrective action program if hazardous
constituents exceed concentration limits at the compliance points specified in the
permit or if the groundwater protection standards have been exceeded. This program
must allow for removing or treating in place any hazardous constituents that exceed
concentration limits and groundwater monitoring to demonstrate effectiveness of the
corrective action.
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The lagoons never operated under a RCRA permit and are no longer active.
However, since analytical data indicate that groundwater in the vicinity of the lagoons
has been degraded due to their operation, the RCRA corrective action requirements
are relevant and appropriate. B~cause all soils with concentrations of explosives
above the health-based remediation criteria will be removed and treated, and
because a separate groundwater investigation and remediation program will occur at
the SV ADA installation, a groundwater monitoring program is not included in this
alternative. Alternative 6 complies only with RCRA corrective action requirements
for soils. The groundwater requirements will be addressed in a subsequent operable
unit.
. As of 8 August 1988, K044 and K047 wastes that are regulated under RCRAmust
meet the land disposal restriction requirements as set forth in 40 CFR 268. These
land disposal restrictions are relevant and appropriate since the lagoon soils may be
considered sufficiently similar to K044 or K04 7 listed wastes. Under the land
disposal regulations, K044 and K04 7 wastes must be deactivated prior to disposal to
, remove the hazardous characteristic of the waste due to reactivity. The regulations
set forth in the Illinois Administrative Code (lAC) also specify that land disposal of
K044 and K047 wastes is prohibited based on reactivity. Testing must be performed
to demonstrate the deactivation prior to land disposal.
. Testing will confirm that the treated soils are below health-based standards and do
not possess any of the characteristics of a hazardous waste. Therefore the treated
soils would no longer be considered a RCRA hazardous waste. However, if the
treated soils are considered hazardous based only on TCLP metals concentrations (40
CFR 261.24), the treated soils will be stabilized so that they will pass the TCLP
criteria. In this instance, the treated soils would no longer be considered hazardous
based on reactivity or TCLP leachate testing and may potentially be considered as
inert wastes under the state regulations. These stabilized materials would be
disposed in compliance with RCRA Subtitle D requirements.
.
Incineration of RCRA hazardous waste is regulated under 40 CFR 264 Subpart °
and 35 lAC 724 Subpart 0, which applies to owners and operators who incinerate
hazardous wastes. The regulations call for an analysis of the waste feed (40 CFR
264.341 and 35 lAC 724.441) collected during the trial bum of the incinerator
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(required under 40 CFR 270.19 and 270.62). In addition, the incinerator must meet
performance standards stated in 40 CFR 264.343 and 35 lAC 724.443, operating
requirements as stated in 40 CFR 264.347 and 35 lAC 724.445, and closure
requirements as stated in 40 CFR 264.351 and 35 lAC 724.451. Alternative 6 will
be implemented in compliance with these relevant and appropriate regulations. The
requirements for a permit to incinerate hazardous wastes from the IEP A are set forth
in 35 lAC 703. Alternative 6 will be implemented in compliance with the substantive
requirements of this permit although obtaining the actual permit will not be required.
.
In addition to the waste feed analysis during the trial burn, the owner or operator
must conduct waste feed analyses throughout the routine operation of the incinerator
based on operating permit requirements. In addition, the owner or operator, upon
closure of the incinerator, must remove all hazardous waste and hazardous waste
residues (including, but not limited to, ash, scrubber wastes, scrubber sludges, and
spent carbon) from the incinerator site. The owner or operator will become a
. generator of hazardous waste (and be subject to regulations under 40 CFR 264 and
35 lAC 724) if the residue removed from the incinerator is a hazardous waste.
Alternative 6 will be implemented in compliance with this relevant and appropriate
regulation.
. The State of Illinois requires under 35 lAC 808 that all waste be considered as either
special waste or declassified waste. The waste currently must be classified by toxic
score. The purpose of classifying the wastes is to ensure that special wastes receive
appropriate handling as specified by the manifesting requirements of 35 lAC 809. It
is not expected that the treated soils will be considered a special waste since the
organic compounds will be destroyed and, if necessary, stabilized for disposal. In any
case, in this alternative, the treated soils remain on-site and are not subject to the
special waste manifesting requirements. If the treated soils should be sent off-site,
their status with regard to special or declassified waste will be reevaluated. Based
on this determination, they will be handled as such.
. The requirements for solid inert waste landfills contained in 35 lAC 811 include:
leachate testing under field conditions, a minimum post closure care, erosion control
and monitoring for settlement, leachate collection and testing, and a minimum of 3
feet of soil cover. In this alternative, it is not planned to conduct leachate testing
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under field conditions, monitoring for settlement, or collect leachate samples for any
other testing since only treated soil and not debris is backfilled on-site. An
exemption from the 3 feet of soil cover may be in order such that the thickness of
the cover may be less than 3 feet (6 inches will be sufficient to support vegetation).
The 3 feet of soil cover would be appropriate for inert and irregularly-shaped wastes
such as bricks, concrete, etc. so that a uniform surface can be maintained. However,
in this alternative, the topsoil is covering treated soil that meets all the treatment
criteria and the TCLP criteria. This cover would only need to serve as a means to
establish vegetation so that erosion would not occur or is minimized. This alternative
will comply with state cover requirements for solid inert waste landfills. During the
RD/RA phase of work at the SV ADA Washout Lagoon Area, the state will make
a decision on any exemption from the state regulations that is requested.
.
State and National Ambient Air Quality Standards (NAAQS) will be applicable for
remedial activities that result in airborne discharges from the site (40 CFR 50).
Alternative 6 will be implemented in compliance with these requirements during
. excavation and incineration activities.
.
Lagoon surface water groundwater encountered during excavation and wastewater
generated during process operations will be treated to the health-based level of 2
mg/L TNT. Therefore the disposal of the water would not be regulated under
RCRA. Any storage or treatment of the water will comply with RCRA regulations
for tanks (40 CFR 264 Subpart J) and NPDES discharge requirements, if necessary.
2.11.3 Cost-EfTectiveness
The selected remedy provides overall effectiveness proportionate to its costs. This
alternative is less expensive and more protective than Alternatives 4 and 7. Although
Alternative 6 is more costly than Alternative 5, Alternative 6 offers a reliable increase in
human protectiveness that is proportionate to the added expense. Incineration is a well-
proven technology that can achieve all the cleanup and lower treatment criteria. The degree
of success that solvent extraction can achieve for the SV ADA Washout Lagoon Soils
remains to be determined and it is not expected to achieve results equal to incineration.
In addition, a waste spent solvent stream must be treated off-site, whereas, for incineration,
all activities remain on-site.
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" If D. "
Finally, Alternatives 1, 2, and 3 leave a potential source for groundwater contamination in
place. The added protection of human health and the environment that Alternative 6
provides justifies the incremental cost incurred.
2.11.4 Utilization of Permanent Solutions and Alternative Treatment Technolo&ies or
Resource Recovery Technolo&ies to the Maximum Extent Practicable ("MEP")
The selected remedy is a permanent solution that provides the best balance of tradeoffs
among the alternatives evaluated with respect to the primary balancing criteria. The criteria
that were most critical in the selection decision were long-term effectiveness and
. .
permanence and implementability. In Alternative 6, the selected remedy, all of the TNT
and explosives contamination above health-based levels will be destroyed and there will be
no process by-products or residual solvent in the soils. Although not expected, if the treated
soils fail the TCLP criteria for metals, they will be stabilized prior to disposal. Therefore,
Alternative 6 utilizes a permanent solution to address the explosives contamination in the
Washout Lagoon Area so that in the short- and long-term, there is no longer a potential
source of groundwater contamination.
The selected remedy can be readily implemented in a short time frame. Rotary kiln
incineration is the only method that has been approved by DDESB for treatment of
explosives-contaminated soils. The tradeoffs among the alternatives wjth respect to the five
balancing criteria are highlighted as follows:
.
Long-term etTectiveness and permanence - In the selected remedy, Alternative 6, the
explosives contamination is destroyed and there are no process by-products or
residual solvent in the soils. The remaining alternatives either leave a source for
potential groundwater contamination or involve a limited risk from treatment
residuals or transportation of treatment residuals.
.
Reduction of toxicity, mobility, and volume of contaminants - In Alternatives 6 and
7, contaminant toxicity, mobility, and volume are virtually eliminated. In the
remaining alternatives either the toxicity, mobility, and volume of cOlitaminants are
not reduced or they are reduced, but not to the degree that Alternative 6 provides.
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.
Short-term etTectiveness - For Alternative 6, the main short-term risk is from thermal
unit (incinerator) air emissions. These will be controlled by an off-gas treatment
system. In Alternatives 1 and 2, current risks are not mitigated. For Alternatives 3
through 7, dust suppression measures will be implemented to minimize dust
generation.
,
.
.
Implementability - All of the alternatives can be readily implemented. However, the
selected remedy is an approved method for treatment of explosives-contaminated
soils for which a number of vendors are available and which can be implemented in
the least amount of time. Permits are not needed for this action since it is to be
conducted entirely on-site. Alternatives 4 and 5 would likely require treatability
studies to determine optimum process parameters. In Alternative 7, it may be
difficult to gain acceptance of the soils at an off-site RCRA facility.
.
Cost - The selected remedy involves costs that are proportionate to overall
. protectiveness:
Capital Cost - $10,230,000
Annual O&M cost - $11,400 for 2 years
Total Present Worth Cost - $10,251,000
The IEPA, the U.S. Army, and the community have responded favorably to the selection of
Alternative 6, and therefore, no modifications to the proposed remedy are required.
Alternative 6: On-Site Thermal Treatment and On-Site Disposal of Upper and Lower
Lagoon Area Soils, meets the statutory requirement to utilize permanent solutions and
treatment technologies to the maximum extent practicable.
2.11.5 Preference for Treatment as a PrinciDal Element
The statutory preference for treatment is satisfied as thermal treatment or incineration is
the primary means by which explosives contaminants will be addressed and destroyed. The
selected alternative satisfies this preference by treatment of the principal threat, the
contaminated soils. The selected alternative would treat all of the contaminated soils to
below health-based levels.
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,
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DOCUMENTATION OF SIGNIFICANT CHANGES
. The U,S, EPA, IEPA, and the U,S. Army reviewed all written and verbal comments
submitted during the public comment period. Upon review of these comments and
comments received during the public meeting, it was determined that no significant changes
to the preferred remedy outlined in the Proposed Plan were necessary,
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