PB94-964055
EPA/ROD/R04-94/184
September 1994
EPA Superfund
Record of Decision:
Alabama Army Ammunition Plant,
Operable Unit 2, Childersburg, AL,
8/30/1994
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BH
U.S. ARMY INSTALLATION
RESTORATION PROGRAM
FINAL
INTERIM
RECORD OF DECISION
ALABAMA ARMY AMMUNITION PLANT
STUDY AREAS 12 AND D OF THE
AREA A SOIL OPERABLE UNIT
AUGUST 1994
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.
AEC Form 45, 1 Feb 93 replaces THAMA Form 45 which is obsolete.
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%<€O sr.,,
W*
' UNITED.STATES ENVIRONMENTAL PROTECTION AGENCY
'
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This action 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.
Sincerely,
\ "Jfai**,
John H. Hankinson, Jr. •
Regional Administrator
cc: Richard Isaac, U.S. Army Environmental Center
Kenneth Gray, U.S. Army Corps of Engineers
C.H. Cox, Alabama Department of Environmental Management
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\Sf "14 10:54flM BflSE CLOSURE DIV. P.2/3
INTEBIM
RECORD OF DECISION
ALABAMA ARMY AMMUNITION PLANT
STUDY AREAS 12 AND D OF THE
AREA A SOIL OPERABLE UNIT
AUGUST 1994
Lieutenant Colonel B,L. Martin Date
Commander, Holsion Army Ammunition Plant
Commander, Alabama Army Ammunition Plant
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U.S. ARMY INSTALLATION
RESTORATION PROGRAM
FINAL
INTERIM
RECORD OF DECISION
ALABAMA ARMY AMMUNITION PLANT
STUDY AREAS 12 AND D OF THE
AREA A SOIL OPERABLE UNIT
AUGUST 1994
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 Page
DECLARATION OF THE INTERIM RECORD OF DECISION 1
DECISION SUMMARY 3
1.0 Site Name, Location, and Description 3
1.1 Physiography 3
1.2 Climate 3
1.3 Surface Hydrology 3
1.4 Geologic Setting 5
1.5 Land Use 5
1.6 Soils 5
1.7 Groundwater 7
1.8 Ecological System 7
2.0 Site History and Enforcement Activities 7
3.0 Highlights of Community Participation 12
4.0 Scope and Role of the Area A Soil OU 12
5.0 Summary of Site Characteristics 13
5.1 Magazine Area (Study Area 11) 13
5.2 Old Burning Ground (Study Area 12) 18
5.3 Small Arms Ballistics Range 18
5.4 Cannon Range - 19
5.5 Old Well (Study Area 15) 19
5.6 Propellant Shipping Area (Study Area 17) 19
5.7 New Trench Area (Study Area D) 20
5.8 Disposal Area (Study Area E) 20
5.9 Number 2 Rubble Pile 21
5.10 229 Area 21
6.0 Summary of Site Risks 21
6.1 Introduction 21
6.2 COPCs 22
6.3 Exposure Assessment 22
6.4 Toxicity Assessment 27
6.5 Risk Characterization 28
6.6 Uncertainty Analysis 29
6.7 Summary 32
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TABLE OF CONTENTS (continued)
Section Page
7.0 Description of Alternatives 34
7.1 Alternative lA~Excavation and On-site Solidification/Stabilization 36
of Contaminated Soil, On-site Disposal
7.2 Alternative IC-Excavation and Off-site Disposal of Contaminated Soil 36
7.3 Alternative ID—Excavation and Stockpiling of Contaminated Soil 37
in Area B RMCSs
7.4 Alternative IE-No Action 38
8.0 Summary of the Comparative Analysis of Alternatives 38
8.1 Threshold Criteria 38
8.2 Primary Balancing Criteria 41
8.3 Modifying Criteria 43
9.0 Selected Remedy and Remediation Levels , 43
10.0 Statutory Determinations 44
10.1 Protection of Human Health and the Environment 45
10.2 Compliance with ARARs 45
10.3 Cost Effectiveness 47
10.4 Utilization of Permanent Solutions and Alternative Treatment 47
Technologies or Resource Recovery Technologies to the
Maximum Extent Practicable
10.5 Preference for Treatment as a Principal Element 48
11.0 Documentation of Significant Changes - 48
RESPONSIVENESS SUMMARY 49
1.0 Overview 49
2.0 Background on Community Involvement 49
3.0 Summary of Public Comment and Agency Response 49
4.0 Remaining Concerns 53
COMMUNITY RELATIONS ACTIVITIES AT AAAP 54
REFERENCES 55
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LIST OF TABLES
Table Page
1 AAAP Area A Study Areas 10
2 Concentrations of Contaminants of Potential Concern at AAAP Area A 14
3 Summary of Toxicity and Carcinogenicity of COCs at Area A of AAAP 15
4 Study Areas 11, 12, D, E, and H Exposure Concentrations-Post-Cleanup 23
5 Summary of the Exposure Pathways Analyzed for the Quantitative RA 25
6 Exposure Factors Used to Calculate Residential, Worker, and Hunter
Exposure to Soil Contaminants 26
7 Potential Ecological Exposure Pathways for all Study Areas in Area A 28
8 Summary of Potential Risks and His Exceeding Target Values for Soil
Exposure at AAAP Area A~Post Cleanup 29
9 Ecological Risk Values for Terrestrial Animals, AAAP Area A Post-Cleanup 30
10 Summary of Chemical Parameters Detected in Area A Soils at
Concentrations Exceeding Cleanup Criteria 33
11 Assumptions Used in Calculating Remediation Levels for COCs 35
LIST OF FIGURES
Figure Page
1 Location Map of AAAP 4
2 Installation Divisions at AAAP 6
3 Study Areas Within Area A at AAAP 9
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LIST OF ACRONYMS AND ABBREVIATIONS
AAAP
AAC
ADEM
ARAR
B2EHP
CAA
CERCLA
CFR
COC
COPC
CPF
CSF
CRP
13DNB
DNT
DOD
DOT
EPA
ESA
EQ
OF
FS
gal
GOCO
H2SO4
HI
HQ
mp
m
mg/L
mg/kg
MTV
NC
NCP
NEPA
NNDPA
NPL
O&M
OU
OSHA
ppm
RA
RCRA
RfD
RI
Alabama Army Ammunition Plant
Alabama Administrative Code
Alabama Department of Environmental Management
applicable or relevant and appropriate requirement
bis(2-ethylhexyl)phthalate
Clean Air Act
Comprehensive Environmental Response, Compensation,
and Liability Act
Code of Federal Regulations
chemical of concern
chemical of potential concern
cancer potency factor
carcinogenic slope factor
Community Relations Plan
1,3-dinitrobenzene
dinitrotoluene
Department of Defense
Department of Transportation
U.S. Environmental Protection Agency
Endangered Species Act
ecotoxicity quotient
degrees Fahrenheit
feasibility study
gallon
government-owned/contractor-operated
sulfuric acid
hazard index
hazard quotient
Installation Restoration Program
meter
milligrams per liter
milligrams per kilogram
mobility, toxicity, or volume
nitrocellulose
National Oil and Hazardous Substances Pollution
Contingency Plan
National Environmental Policy Act
n-nitrosodiphenylamine
National Priorities List
operation and maintenance
Operable Unit
Occupational Safety and Health Act
parts per million
risk assessment
Resource Conservation and Recovery Act
reference dose
remedial investigation
411/1081594
IV
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LIST OF ACRONYMS AND ABBREVIATIONS (continued)
RI/FS
RMCS
ROD
SARA
TCLP
tetryl
246TNT
TNT
TSCA
USAGE
use
UCL95%
USAEC
USATHAMA
Western
WWII
yd3
remedial investigation/feasibility study
retrievable monitored containment structure
Record of Decision
Superfund Amendments and Reauthorization Act of 1986
toxicity characteristic leaching procedure
2,4,6-trinitrophenylmethylnitramine
2,4,6-trinitrotoluene
trinitrotoluene
Toxic Substance Control Act
U.S. Army Corps of Engineers
United States Code
95 percent upper confidence level
micrograms per gram
U.S. Army Environmental Center
U.S. Army Toxic and Hazardous Materials Agency
Roy F. Weston, Inc.
World War II
cubic yard
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DECLARATION OF THE INTERIM RECORD OF DECISION
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DECLARATION OF THE INTERIM RECORD OF DECISION
SITE NAME AND LOCATION
Alabama Army Ammunition Plant
Area A Soil Operable Unit
P.O. Box 368
Childersburg, AL 35044-0368
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected interim remedial action for the soils of Study Areas
12 and D within the Area A Soil Operable Unit (OU) at Alabama Army Ammunition Plant
(AAAP), Childersburg, AL, which was chosen in accordance with the Comprehensive
Environmental Response, Compensation, and Liability Act (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 the site.
This interim remedial action is being taken to protect human health and the environment from
unacceptable risks. This action is an interim final action for the soils of Study Areas 12 and D of
the Area A soils operable unit.
The U.S. Environmental Protection Agency (EPA) and the State of Alabama concur with the
selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this site, if not addressed by
implementing the response action selected in this Interim Record of Decision (ROD), may present
an imminent and substantial endangerment to public health, welfare, or the environment.
DESCRIPTION OF THE SELECTED REMEDY
The Stockpile Soils Area OU, the first OU to address contaminated soils at AAAP Area A,
involved treatment of contaminated soils that were excavated from Area A and stored in
retrievable monitored containment structures (RMCSs) in Area B. The initial remedial actions
that led to the soils stockpiling were performed based on findings of the remedial
investigation/feasibility study (RI/FS) of AAAP completed in 1986. Cleanup activities at Area A
included building decontamination and demolition and contaminated soil excavation and
stockpiling. A ROD for treatment [i.e., incineration followed by solidification/stabilization (if
required)] of the Stockpile Soils Area OU soils was signed on December 31, 1991. In 1990,
EPA indicated that additional investigations needed to be conducted at Area A to ensure that no
residual contamination remained on site; therefore, a supplemental remedial investigation (RI)
was conducted in 1991. The Area A Soil OU is the second OU at AAAP Area A and it
addresses the contaminated soils that were identified during the 1991 supplemental investigation.
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The Area A Soil OU addresses the principal threats from lead and explosives contamination by
excavating the newly identified contaminated soils from Study Areas 12 and D of Area A and
storing the contaminated soils in RMCSs in Area B. Treatment of these contaminated soils will
be consistent with that method specified in the Stockpile Soils Area OU [incineration followed by
solidification/stabilization (if required) or stabilization only (if applicable)]. The scope of this
Interim ROD is limited to the soils of Study Area 12 and D within the Area A Soil OU. A
supplemental Risk Assessment (RA) and Feasibility Study (FS), and a final ROD will be
developed upon completion of the additional soils sampling at AAAP Area A. The soil sampling
effort was initiated to screen soils not previously sampled for full scan analysis and to establish
the background levels at Area A.
The major components of the selected remedy for the soils of Study Area 12 and D within the
Area A Soil OU include:
Excavation of approximately 3,800 cubic yards (yd3) of lead-contaminated soils from
Study Area 12 and 5 yd3 of explosives-contaminated soils from Study Area D of
Area A,
Transportation of contaminated soils to Area B and storage along with the Stockpile
Soils Area OU soils in RMCSs,
On-site treatment (in Area B) by incineration followed by solidification/stabilization (if
required) or stabilization only (if applicable) of contaminated soils along with the
Stockpile Soils Area OU soils [the remediation of the Stockpile Soils Area OU soils
was presented in the Stockpile Soils Area OU ROD], and
On-site disposal of treated soil at a designated area in Area B.
STATUTORY DETERMINATIONS
This interim action is protective of human health and the environment, complies with Federal and
State requirements that are legally applicable or relevant and appropriate for this limited scope
remedial action, and is cost-effective. Although this interim action is not intended to fully
address the statutory mandate for permanence and treatment to the maximum extent practicable,
this interim action utilizes treatment and thus is in furtherance of that statutory mandate. Because
this action does not constitute the final remedy for the operable unit, the statutory preference for
remedies that employ treatment that reduces toxicity, mobility or volume as a principal element
although partially addressed in this remedy, will be addressed by the final response action.
Subsequent actions are planned to address fully the threats posed by the conditions at this
operable unit. Because this remedy will not result in hazardous substances remaining on-site in
Area A above health based levels, the five year review will not apply to this action.
Lewis D. Walker Date
Deputy Assistant Secretary of the Army
(Environment, Safety, and Occupational Health)
411/1081594
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INTERIM
RECORD OF DECISION
ALABAMA ARMY AMMUNITION PLANT
STUDY AREAS 12 AND D OF THE
AREA A SOIL OPERABLE UNIT
AUGUST 1994
Lieutenant Colonel B.L. Martin Date
Drnmander, Holston Army Ammunition Plant
immander, Alabama Army Ammunition Plant
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DECISION SUMMARY
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DECISION SUMMARY
1.0 SITE NAME. LOCATION. AND DESCRIPTION
Alabama Army Ammunition Plant (AAAP) is located in Talladega County in east-central
Alabama, 30 miles east-southeast of Birmingham and 70 miles north of Montgomery, the State
capital (Figure 1). The nearest town is Childersburg, AL, which is 4 miles south of AAAP.
This interim remedial action is limited to contaminated soil in Study Areas 12 and D of AAAP
Area A, hereinafter referred to as the Area A Soil OU. This action is an interim action for
Study Areas 12 and D within Area A. A Risk Assessment (RA), a Feasibility Study (FS), and a
final Record of Decision (ROD) for the Area A Soils Operable Unit (OU) will be developed upon
completion of the soils sampling at AAAP Area A. The soil sampling effort was initiated to
establish the background contaminant concentrations within Area A.
1.1 Physiography
AAAP is located within the Coosa Valley district of the Valley and Ridge physiographic
province. The border between the Valley and Ridge province and the Piedmont province is south
of AAAP between Talladega and Tallaseehatchee Creeks.
1.2 Climate
Talladega County's climate is temperate. The weather during fall, winter, and spring is
controlled by frontal systems and contrasting air masses. Summer weather, which lasts from
May or June until September or October, is almost subtropical because maritime tropical air
prevails along the Bermuda high-pressure system.
Average daily temperatures in Talladega are 75 degrees Fahrenheit (°F) for the high and 50°F
for the low. Summer high temperatures are commonly 90°F or above; occasionally, maximum
temperatures exceed 100°F. Temperatures below 32°F occur approximately 60 days per year,
primarily in December and January.
Mean annual rainfall is 52 inches. The lowest average monthly rainfall (2.2 inches) occurs in
October, and the highest average monthly rainfall (6.4) occurs in March. Talladega County has
two rainy seasons per year. The winter rainy season is from December to April, with the
majority of the rain associated with the passage of frontal systems. The summer rainy season is
from May through September, with the highest rainfall occurring in June and July. Summer .
rains are normally convective thunderstorms.
1.3 Surface Hydrology
The majority of the surface runoff from AAAP drains either west or southwest into the Coosa
River. A small portion of the southern and eastern side of AAAP drains toward Talladega
Creek, a tributary of the Coosa River. Prior to the construction of AAAP, the area consisted of
farms, woodlands, and wetlands. Much of the western half of AAAP was poorly drained. Small
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F: \..\AAAP\F1G1.DWG
PLOTTED: Mor 30. 1994 - 07:25:34
SCALE
0.5
0.5 1 MILE
I
BIRMINGHAM • A?
AAAP<»_/
FIGURE 1
LOCATION MAP OF AAAP
SOURCE : ESE.
Prepared for :
U.S. Army Environmental Center i
Aberdeen Proving Ground, Maryland
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natural drainways were enlarged and rerouted to provide drainage from the various manufacturing
operations.
As shown in Figure 2, two natural drainage systems conveyed surface runoff from AAAP, west
to the Coosa River. Liquid industrial wastes from the explosives manufacturing operations were
conveyed west to the Coosa River by a man-made channel. No natural ponds existed on AAAP
during its operation; however, two large storage lagoons were constructed to retain industrial
wastes. Extensive wooded swamp and open pond areas have developed in the drainage systems
at AAAP since the beginning of demolition activities in 1973, primarily as a result of damming
of drainways by beavers.
Study Areas 12 and D of the Area A Soil OU are located in a clear, well-drained area near the
northeast boundary of Area A.
1.4 Geologic Setting
The bedrock underlying AAAP has been mapped on a regional scale and has been identified as
die undifferentiated Knox group of Upper Cambrian to Lower Ordovician age dolomite. The
dolomite underlying AAAP is thick- to medium-bedded; cherty; and penetrated by numerous
cavities, joints, and fractures. The dolomite is overlain by residual soil derived from weatiiering
processes. This soil matrix consists primarily of clay, with some silt, sand, and occasional chert
boulders, and varies in thickness from less than 3 feet to more than 80 feet.
1.5 Land Use
AAAP is currently in an inactive caretaker status with controlled access. The only activity
occurring on AAAP is occasional Army-supervised logging. The land surrounding AAAP is a
mixture of recreational and industrial. AAAP is bordered on the west side by a country club; on
the south by a paper products company; on the east by wooded, private property; and on the
north by a water treatment plant. Future land use of the AAAP property is expected to consist of
wildlife habitat, hunting grounds, and occasional logging of wooded areas. Area A, which
includes Study Areas 12 and D of the Area A Soil OU, was auctioned and conveyed to private
buyers in 1990 and is currently used for hunting grounds and occasional logging.
1.6 Soils
The soils at AAAP (Areas A and B) are generally divided into three associations. Soils of the
Bodine-Minvale Association are found on the high ground of the eastern portion of AAAP. This
association is composed of deep, well-drained, steep, cherty, medium-textured soils derived from
limestone and dolomite. Most of AAAP is covered by soils of the Decatur-Dewey-Fullerton
Association, which are also deep, well-drained, loam soils derived from limestone and dolomite.
The soils of the floodplains of Talladega Creek and the Coosa River have been classified as the
Chewacla-Chenneby-McQueen Association. These are deep, nearly level, alluvial loam soils that
grade from somewhat poorly drained to well-drained and are subject to flooding. .
These broad-based associations represent agricultural classifications rather than engineering
descriptions. Soil constitution at AAAP, and thus the Area A Soil OU, within the three
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AAAP Site Boundary
Drainage Feature
Sludy Ar eas
Area A arid B Boundar- i os
Water
Uet I and
1.500 0 1,500 3.000 FEET
FIGURE 2
INSTALLATION DIVISIONS AT AAAP
SOURCE : ESE.
Prepared for :
U.S. Army Environmental Center
Aberdeen Proving Ground, Maryland
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associations may range from soils consisting primarily of sand and silt with little clay to soils
comprised almost entirely of clay.
1.7 Groundwater
Potable groundwater from the dolomite aquifer of the Coosa Valley supplies the needs of the
communities, homes, farms, and industries around AAAP. The majority of the successful wells
draw water from the solution cracks and cavities in the dolomite. A few wells are completed in
the residual soil, but these wells are less productive than those drilled into the dolomite.
1.8 Ecological System
The environment at AAAP has been disturbed 3 times in the past 40 years. Prior to construction
of the facility, the area consisted primarily of cropland and woodland. The first major change
occurred during the operational years when much of AAAP consisted of maintained industrial
areas. In the second major change, the Army instituted a woodland management plan, following
closure operations, that extensively modified AAAP by allowing 3,411 acres of controlled pine
forest to be planted. The third major change occurred as a result of demolition of various areas
following closure operations.
Currently, many of the formerly maintained drainages, pine plantations, and cleared areas have
undergone considerable vegetative overgrowth. Much of the planted pine has been harvested,
and reforestation has occurred through natural revegetation. Damming of surface drainages by
beavers has modified the drainage systems; drainage has become much slower, and extensive
wooded swamp and shallow pond areas have developed. As a result of these changes, the major
ecological systems currently consist of the following types: grassland/old field associations,
upland pine forest/pine'plantations, oak forests, low moist pine woods, hardwood swamps,
intermittent streams, shallow ponds, and drainage ditches.
These systems support abundant populations of aquatic and terrestrial organisms. White-tailed
deer, introduced in the 1960s, have become particularly abundant, as have certain predators (the
red-tailed hawk, the marsh hawk, and the bobcat).
The extensive development of shallow beaver ponds has resulted in large populations of
amphibians and aquatic reptiles, and the East Beaver Pond provides roosting for waterfowl.
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
AAAP was established on 13,233 acres of land near the junction of Talladega Creek and the
Coosa River. The plant was built in 1941 and operated during World War II (WWII) as a
government-owned/contractor-operated (GOCO) facility. AAAP produced nitrocellulose (NC),
single-based smokeless powder, and nitroaromatic explosives [i.e., trinitrotoluene (TNT),
dinitrotoluene (DNT); and 2,4,6-trinitrophenylmethylnitramine (tetryl)]. Activities at AAAP
included the manufacture of explosives; DNT; and the chemicals sulfuric acid (H2SO4), aniline,
N,N-dimethylaniline, and diphenylamine. Spent acids were recycled and wastes resulting from
these operations were disposed of. In August 1945, operations were terminated at AAAP, and
the plant was converted to standby status.
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The plant was maintained in various stages of standby status until the early 1970s. In 1973, the
Army declared AAAP excess to its needs. Since that time, several parcels of the original
property, including Area A, were sold or returned to their previous owners. In 1977, a 1,354-
acre parcel was sold to Kimberly Clark, Inc. for construction of a paper products plant. Area A,
encompassing 2,714 acres, was auctioned in May 1990. Future land uses for these properties is
expected to consist of wildlife habitat, hunting grounds, and occasional logging of wooded areas.
In 1978, the U.S. Army Toxic and Hazardous Materials Agency (USATHAMA), managing the
Army's Installation Restoration Program (IRP), conducted a record search that concluded that
specific areas of the facility were potentially contaminated by explosives and lead compounds.
Further studies at AAAP confirmed soils contamination with explosives compounds, asbestos,
and lead. Several investigations were conducted between 1981 and 1983 to define contamination
further. In 1984, AAAP was proposed for inclusion on the CERCLA (Superfund) National
Priorities List (NPL).
An RI/FS under the Department of Defense (DOD) IRP was initiated in 1985 to determine the
nature and extent of contamination at AAAP and the alternatives available to clean up the site.
For the purposes of the RI/FS, the facility was divided into two general areas. Area A consisted
of the eastern portion of the facility, and Area B consisted of the western portion (Figure 2).
The initial RI under the IRP confirmed the existence of explosives, asbestos, and lead
contamination in the soil in Area A, and in the soil, sediment, and groundwater in Area B. The
RI for Areas A and B was completed in 1986. As a result of the findings of the RI, cleanup
activities at Area A were conducted in 1986 and 1987, which included building decontamination
and demolition, soil excavation, and stockpiling. Initially, 36,400 yd3 of contaminated soils were
excavated from Area A and stockpiled in Area B in two covered buildings and on a concrete slab
that was subsequently covered with a membrane liner. In July 1987, AAAP was placed on the
NPL.
Area A includes the Magazine Area (Study Area 11), Old Burning Ground (Study Area 12),
Small Arms Ballistic Range (Study Area 13), Cannon Range (Study Area 14), Old Well (Study
Area 15), the eastern portion of the Propellant Shipping Area (Study Area 17), and a parcel of
woodland outside the security fenceline. Additional areas identified during subsequent
investigations conducted at the site following preparation of the original feasibility study (FS)
report include the Rubble Pile (Study Area C), the New Trench Area (Study Area D), the
Disposal Area (Study Area E), the Number 2 Rubble Pile (Study Area F), the Henningsburg
Area (Study Area G), and the 229 Area (Study Area H). An overall layout of Area A showing
the locations of all study areas is presented in Figure 3. The study areas within Area A and their
descriptions are presented in Table 1.
In 1990, EPA indicated that additional investigations needed to be conducted at Area A to ensure
that no residual contamination remained. Area A was conveyed to private buyers in August
1990, with the provision that additional investigations would be performed.
In 1991, a supplemental RI was conducted to verify the effectiveness of the completed remedial
actions in Area A. The supplemental RI determined that soils at two study areas within Area A
(Study Areas 12 and D) continue to contain lead and explosives at unacceptable concentrations.
The supplemental RI/FS concluded that approximately 3,800 yd3 of lead-contaminated soil from
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Mor 31. 1994 - 12:47:34
F: \..\MIKEAAAAP\F1G3.DWG
SCALE
1.125 0
1.125 2.250 FEET
LEGEND
AAAP Site Boundary
Study Area
MMii11 Area A & B boundaries
Water
Wetland
FIGURE 3
STUDY AREAS WITHIN AREA A AT AAAP
SOURCE : ESE.
Prepared for :
U.S. Army Environmental Center
Aberdeen Proving Ground, Maryland
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Table 1. AAAP AREA A STUDY AREAS
Study Area Description
11 Magazine Area
12 Old Burning Ground
13 Small Arms Ballistics Range
14 Cannon Range
15 Old Well
17 Propellant Shipping Area
(Eastern Portion)
C Rubble Pile
D New Trench Area
E Disposal Area
F Number 2 Rubble Pile
G Henningburg Area
H 229 Area
Source: ESE, Inc.
411/1081594
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Study Area 12 and approximately 5 yd3 of explosives-contaminated soil from Study Area D
required further remediation as a part of this interim action. Subsequent evaluation of the
background levels for chromium and arsenic at the site indicate that the levels of these metals
observed at the various study areas (including Areas 12 and D) may present a health risk. These
metals concentrations are observed across the entire site at these elevated concentrations. As
these metals were not a part of the manufacturing process of explosives, their existence a the site
requires additional interpretation. This interpretation and the presentation of any identified health
risk will be presented in the final ROD being prepared for the site. This continued data analysis
should not interfere with the removal action being planned which deals only with the explosives
and lead contamination.
The following documents outline the results of the initial assessment of AAAP, cleanup actions
conducted in Area A, and the investigations of the Area A Soil OU including Study Areas 12 and
D. More detailed information is available in documents for public review at the following
locations: the Library Service, Alabama Public Information, Montgomery, AL; the B.B. Comer
Memorial Library and Information Center, Sylacauga, AL; and the Earle A. Rainwater Memorial
Library, Childersburg, AL.
1. Installation Assessment of Alabama Army Ammunition Plant, Report 130, May
1978.
2. Alabama Army Ammunition Plant, Area A Remedial Actions, Final Report,
February 1988.
3. Stockpile Characterization Report for Alabama Army Ammunition Plant,
Childersburg, Alabama, July 1991.
4. Feasibility Study for the Alabama Army Ammunition Plant Stockpile Area, October
1991.
5. Proposed Plan for Early Remedial Action of Stockpile Soils at Alabama Army
Ammunition Plant Stockpile Soils Area Operable Unit, November 1991.
6. Record of Decision for Early Remedial Action of Stockpile Soils at Alabama Army
Ammunition Plant Stockpile Soils Area Operable Unit, December 1991.
7. Supplemental Remedial Investigation/Feasibility Study for Area A, Alabama Army
Ammunition Plant, Final Baseline Risk Assessment, 1992.
8. Supplemental Remedial Investigation/Feasibility Study for Area A, Alabama Army
Ammunition Plant, Final Feasibility Study, December 1992.
9. Supplemental Remedial Investigation/Feasibility Study for Area A Soil Operable
Unit, Alabama Army Ammunition Plant, Proposed Plan for Early Remedial Action
of Contaminated Soils, January 1993.
.1/1081594 11
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3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
In accordance with the Army's Community Relations Plan (CRP) for AAAP, October 1990, the
FS and the Proposed Plan for this ROD were released to the public on March 31, 1993. The
public comment period started on April 1, 1993, and ended on April 30, 1993. Documents were
made available to the public at the following locations: the Library Service, Alabama Public
Information, Montgomery, AL; the B.B. Comer Memorial Library and Information Center,
Sylacauga, AL; and the Earle A. Rainwater Memorial Library, Childersburg, AL. The notice of
availability of the Proposed Plan was published in Daily Home, Birmingham News, Anniston
Star, and Montgomery Advertiser on March 30, 1993.
In accordance with the CRP, a public meeting was held at Central Alabama Community College
on April 20, 1993 to inform the public of the preferred alternative and to seek public comments.
At this meeting, representatives from AAAP, EPA, the Alabama Department of Environmental
Management (ADEM), the U.S. Army Corps of Engineers (USAGE), and Army Environmental
Center (AEC) were present and answered questions about the site and the remedial alternatives
under consideration. A response summary to the public comments received during the public
comment period and hearing is included in the Responsiveness Summary section of this report.
The Proposed Plan identified Alternative ID as the preferred remedy. Alternative ID, which is
described in the FS, consists of excavation of Area A contaminated soils, transportation to
Area B, storage with stockpiled soils, on-site treatment (in Area B) along with the stockpiled
soils, and on-site disposal of treated soils at a designated area in Area B. This action is an
interim action for soils of Study Areas 12 and D within Area A.
AAAP, EPA, ADEM, USAGE, and the AEC reviewed all written and verbal comments
submitted during the public comment period. Review of these comments caused no significant
changes to the preferred remedy outlined in the Proposed Plan. Subsequent discussion between
AAAP, EPA, ADEM, USAGE, and AEC led to a decision to limit the scope of actions to Study
Areas 12 and D only. Additional investigations will determine if additional actions are required
in any other areas of the Area A soils operable unit.
4.0 SCOPE AND ROLE OF STUDY AREAS 12 AND D
WITHIN THE AREA A SOIL OU
OUs are defined as discrete actions that comprise incremental steps toward the final overall
remedy. These actions may completely address a geographic portion of a site or a specific
problem. OUs may also be early actions; however, they must be followed by subsequent actions
to address the scope of the problem definitely.
The Stockpile Soils Area OU, the first OU to address contaminated soils at AAAP Area A,
involved treatment of contaminated soils that were excavated from Area A and stored in RMCSs
in Area B. The initial remedial actions that led to the soils stockpiling were performed based on
findings of the RI/FS of AAAP completed in 1986. Cleanup activities at Area A included
building decontamination and demolition and contaminated soil excavation and stockpiling. A
ROD for treatment [i.e., incineration followed by solidification/stabilization (if required)] of the
Stockpile Soils Area OU soils was signed on December 31, 1991. In 1990, EPA indicated that
411/1081594 12
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additional investigations needed to be conducted at Area A to ensure that no residual
contamination remained on site; therefore, a supplemental RI was conducted in 1991. During
this investigation it was decided to split Area A into separate operable units; the Area A Soils
Operable Unit and the Area A Groundwater Operable Unit to facilitate cleanup of the soils while
the groundwater investigation continued. This interim action covers soils of Study Areas 12 and
D within the Area A Soil OU at AAAP and addresses the contaminated soils that were identified
during the supplemental investigation. Additionally, a separate OU is planned to address
groundwater and soil at Area B.
Currently, the contaminated soils of the Stockpile Soils Area OU within Area B are awaiting
remediation. On-site incineration was the selected remedy in the ROD for the Stockpile Soils
Area OU. The ash from the incinerator will be tested for lead contamination and treated by
solidification/stabilization (if required) prior to final disposal.
This action is an interim action and is intended to address only the contaminated soils of Study
Areas 12 and D within the Area A Soil OU. The threats addressed in this interim remedial
action are the contaminated soils located at Study Areas 12 and D. Actual or threatened release
of hazardous substances from these contaminated soils, if not addressed by implementing the
selected early action, may present a current or potential threat to public health, welfare, and the
environment. The Army will propose remedies in a final ROD for the remaining portions of
AAAP following the completion of other RI/FS efforts currently in progress.
5.0 SUMMARY OF SITE CHARACTERISTICS
Areas identified during supplemental investigations conducted at the site following preparation of
the original feasibility study (FS) report include the Rubble Pile (Study Area C), the New Trench
Area (Study Area D), the Disposal Area (Study Area E), the Number 2 Rubble Pile (Study
Area F), the Henningsburg Area (Study Area G), and the 229 Area (Study Area H). Study Area
C was initially presumed to be contaminated; however, because site-related contamination was
not detected at this area, it was not evaluated further.
Significant findings associated with each area investigated during the supplemental RI are
presented in the following paragraphs. A summary of chemicals of potential concern (COPCs)
detected at each area is presented in Table 2. Based on these findings, a supplemental RA was
prepared to assess the impact(s) of the contaminants at each site on human and environmental
concerns and to determine appropriate remediation levels. In May of 1994, background soil
samples were collected as part of the ongoing supplemental RI. Table 2 presents a summary of
the average detected background concentrations of inorganics compared to the average detected
concentrations detected at Areas 12 and D.
A summary of the toxicity and carcinogenicity of the contaminants at Area A is presented in
Table 3. The following discussion summarizes the site characteristics for each study area and
includes a description of the fate and transport of site contaminants.
411/1081594 13
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Table 2. CONCENTRATIONS OF CONTAMINANTS OF POTENTIAL CONCERN (COPCS) AT
AAAP AREA A (MG/KG)
Study
Area
12
D
Note:
Parameter
246TNT
AG
AS
CR
HG
NI
PB
SE
ZN
135TNB
246TNT
AG
AS
CR
CU
NI
PB
ZN
* =
** =
NA
Onsite
Detected Concentration
Average* Maximum
12.9
0.18
32.6
58.4
0.082
38.5
470
0.48
110
3.95
5.10E + 03
0.57
24.2
47.1
3.37E + 03
5.51
16.8
93.3
12.9
0.57
92.5
134
0.14
56.4
1.04E + 04
0.54
202
7.13
1.39E + 04
0.57
68.3
110
3.37E + 03
5.51
89.8
227
Onsite
Frequency
Detected
1/58
4/36
36/36
31/36
8/36
5/36
47/60
2/36
11/36
2/34
3/34
1/34
34/34
26/34
1/34
1/34
34/34
9/34
average of the detected concentrations.
background samples collected in May 1994 as part
not applicable.
Background
Concent."
Avg. Max.
NA NA
<0.59 <0.59
7.65 11.7
23.9 67.6
0.066 0.071
5.22 12.1
23.2 156
0.50 0.72
25.8 71.7
NA NA
NA NA
<0.59 <0.59
7.65 11.7
23.9 67.6
6.81 26.7
5.22 12.1
23.2 156
25.8 71.7
of supplemental
Background
Frequency
Detected
NA
0/27
27/27
27/27
2/27
24/27
27/27
15/27
19/27
NA
NA
0/27
21121
27/27
27/27
24/27
27/27
19/27
RI.
Source: ESE, Inc.
411/1081594
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Table 3. SUMMARY OF TOXICITY AND CARCINOGENICITY OF COCS AT AREA A OF AAAP
(Page 1 of 3)
Chemical
Carcinogens
Inorganic Chemicals (IOC)
Arsenic
Chromium, total12
Lead
Nickel
Nitro Compounds
Dinitrotoluene, 2,4-
Dinitrotoluene, 2,6-
Trinitrotoluene, 2,4,6-
Noncarcinogens
Inorganic Chemicals (IOC)
Copper
Mercury
Selenium
Silver
Zinc
Oral RfD *
(TO) [UF]
0.0003 [3]
(skin)
0.005 [500]
(liver, spleen)
..13
(heme, neural)
0.02'7 [300]
(weight loss)
0.002** [100]
0.001N2 [3,000]
0.0005 [1,000]
(liver)
0.037M [2]
(organoleptic)
0.0003* [1,000] .
(CNS)
0.005 [1]
(blood)
0.006" [3]
(organoleptic)
0.2* [10]
(blood)
Inhal RfD *
[UF] OralCSF* Oral WoE" Inhal CSF* Inhal WoE*
1.8" A 50* A
(skin) (lung)
0.00000057" [300] - 41* A
(lung)
nd16 B2 nd16 B2
(heme, neural) (kidney)
0.84'-17 A
(lung, nasal)
0.68 B2 ndN1 B2
(liver, mammary)
0.68 B2 ndm B2
(liver, mammary)
0.03 C ndN3 C
(liver, kidney)
..
0.000086* [30]
(CNS)
-
..
—
411/1081594
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Table 3. SUMMARY OF TOXICITY AND CARCEMOGEN1CITY OF COCS AT AREA A OF AAAP
(Continued, Page 2 of 3)
Chemical
Oral RfD *
(TO) [UF]
Inhal RfD
[UF]
Oral CSF*
Oral WoE*
Inhal CSF*
Inhal WoE"
Nitro Compounds
Dinitrobenzene, 1,3-
Nitrobenzene
Tetryl
Trinitrobenzene, 1,3,5-
0.0001 [3,000]
(liver)
0.0005 [10,000]
(blood, kidney, liver)
0.01* [10,000]
(skin)
0.00005 [10,000]
(blood, kidney, liver)
0.00057 [3,000]
Note: RfD = reference dose [mg/kg/day].
CSF = cancer slope factor [(nig/kg/day)'1].
WoE = weight of evidence for ranking as a human carcinogen.
inhal = inhalation.
nd = not determined.
MCL = EPA maximum contaminant level.
mg/kg/day = milligrams per kilogram per day.
mg/L = milligrams per liter.
fig/L = micrograms per liter.
L/day = liters per day.
(TO) = target-organ for toxicity.
[UF] = uncertainty and modification factors associated with toxicity value derivation.
— = value not available at this time.
WOE Codes
A =
B =
C =
Human Carcinogen
Probable Human Carcinogen
Possible Human Carcinogen
411/1081594
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Table 3. SUMMARY OF TOXICITY AND CARCBVOGENICITY OF COCS AT AREA A OF AAAP
(Continued, Page 3 of 3)
(II) CSF for arsenic based on unit cancer risk of 5 x l(fs (/ig/L)'1 proposed by Risk Assessment Forum (EPA, 1991a).
(12) All values are for hexavalent chromium; a less conservative oral RfD of 1E+00 mg/kg/day for trivalent chromium is also available.
(13) The inhalation RfD has been removed from IRIS pending further evaluation; this value is from EPA/HEAST, 1991.
(14) RfD for copper based on the MCL of 1.3 mg/L (56 FR 26460) and assumes that a healthy 70 kilogram child consumes 2 L/day water.
(15) EPA prefers to use a biokinetic uptake model to evaluate lead exposure rather than the reference dose method.
(16) Although EPA has classified lead as a Group B2 suspect human' carcinogen via ingestion and inhalation, no CSF has been developed for either of
these exposure pathways.
(17) Value for nickel refinery dust.
(18) RfD for silver based on aesthetic endpoint (argyria).
(Nl) Although EPA has classified this chemical as a Group B2 suspect human carcinogen via inhalation, no CSF has been developed for this exposure
pathway.
(N2) RfD for 2,6-dinitrotoluene based on a subchronic oral NOAEL for dogs of 4 mg/kg/day (ATSDR, 1988), an uncertainty factor of 1,000 (10X for
sensitive human subpopulations, 10X for animal-to-human extrapolation, and 10X for subchronic-to-chronic extrapolation), and a modifying factor
of 3 (incomplete data set).
(N3) Although EPA has classified this chemical as a Group C possible human carcinogen via inhalation, no CSF has been developed for this exposure
pathway.
"All RfDs, CSFs, and WoEs are available in IRIS, 1992, unless otherwise noted.
This value is available in EPA/HEAST, 1992.
*This value is available in EPA/HEAST Supplement A, 1992.
Source: ESE.
411/1081594
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5.1 Magazine Area (Study Area 11)
The Magazine Area, located in the north central portion of Area A and consisting of a series of
storage buildings, is the largest study area in AAAP Area A. The Series 260 Buildings are
designated for storing DNT, the Series 1010 Buildings for storing tetryl, and the Series 811
Buildings for storing TNT.
Soils were sampled at two different times as part of the RI effort and analyzed for munition and
inorganic chemicals. One of the 40 samples collected during post-cleanup as part of the second
sampling effort and tested for munitions indicated the presence of 1,3-dinitrobenzene (13DNB) at
0.53 milligrams per kilogram (mg/kg) concentration.
Only organic chemicals were detected at this study area. The primary migration pathways of
munitions detected in soil are fugitive dust or particulate emission. In addition, due to the
proximity of a hardwood swamp near Study Area 11, the potential exists for chemicals in soil to
migrate to the swamp via surface runoff during periods of heavy rainfall. These compounds may
subsequently undergo photolytic and biological degradation in the swamp. The amount of
munitions reaching groundwater from this area is expected to be low as discussed in Sec. 3.3.2
of the RA because of the low concentrations detected in the soils. Parts of this area are being
logged and cleared for hunting; this exposure pathway was addressed as a current exposure
pathway in the RA.
5.2 Old Burning Ground (Study Area 12) - Addressed by this Interim Action
This study area is located in the northern section of Area A and was the primary disposal site for
unacceptable batches of explosives, propellants, and other reactive wastes. Periodic burning of
the study area's vegetation was practiced during plant operation to minimize the danger of
wildfires. This study area also included a former Lead Remelt Facility. Surface water flow in
this area is intermittent and occurs only during heavy rain events.
Most of the inorganics were uniformly distributed across the sites; however, several inorganics
were detected at levels above site background. As shown in Table 2, arsenic-, chromium, and
lead were detected at levels above the maximum and average detected concentrations observed in
site background samples. In addition, 246TNT was detected in 1 of 58 samples collected at
Study Area 12.
Organic and metallic chemicals were detected at this study area. The primary migration
pathways of munitions and metals detected in soil are fugitive dust or particulate emission. In
addition, the potential exists for chemicals in soil to migrate via surface runoff during periods of
heavy rainfall. The amount of munitions reaching groundwater from this area is expected to be
low because of the low concentrations detected in the soils.
5.3 Small Arms Ballistics Range (Study Area 13)
This study area is approximately 3.7 acres, located centrally at the northern boundary of Area A.
This area was covered by gravel during the operational period and was used as a training range
for small arms ballistics. A ballistics laboratory was adjacent to this area during the operational
period. Currently, no buildings exist on this site.
411/1081594 18
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The results of the soil and sediment sampling indicated the presence of bis (2-ethylhexyl)
phthalate (B2EHP), iron, lead, and n-nitrosodiphenyiamine (NNDPA). Organic and metallic
chemicals were detected at this study area. The primary migration pathways of NNDPA,
B2EHP, and metals detected in soil are fugitive dust or paniculate emission. In addition, the
potential exists for chemicals in soil to migrate via surface runoff during periods of heavy
rainfall. The amount of NNDPA and B2EHP reaching groundwater from this area is expected to
be low because of the low concentrations detected in the soils.
5.4 Cannon Range (Study Area 14)
This study area, used for cannon test firing, is approximately 13 acres located at the northeast
corner of the northern boundary of Area A. Access to this area is restricted by a fence and
locked gate. Since operations ceased at AAAP all buildings have been removed and the
remaining area has not been maintained.
Only lead was detected at this study area, and the lead levels appear to be similar to the
concentrations across Area A. The primary release mechanism for lead at this site would be via
release to the atmosphere as paniculate or dust emissions. However, due to the degree of
vegetative cover and relatively few areas of bare soils, this migration pathway is not considered
significant.
5.5 Old Well (Study Area 15)
t
The Old Well was a relict hand-dug well, located in the northeast portion of Area A, which
served a farm or residence prior to construction of AAAP and was reported to be approximately
30 ft deep and 5 ft in diameter. During the razing of the laboratory building which supported the
explosives manufacturing operations, laboratory reagents, non-sparking paints, 55-gallon (gal)
drums of a tar-like material, fire retardant paint, containers of other unidentifiable materials, and
old tires were reportedly disposed of in this well.
Soil samples contained only lead at a maximum concentration of 12.8 ppm. Surface water
samples contained bis(2-ethylhexyl)-o-phthalate and methylene chloride.
Organic and metallic chemicals were detected at this study area. The primary migration
pathways of the organics and metals detected in soil are fugitive dust or paniculate emission. In
addition, the potential exists for chemicals in soil to migrate via surface runoff during periods of
heavy rainfall. The well and surrounding soils were removed during a remedial action in 1986.
5.6 Propellant Shipping Area (Study Area 17)
The propellant shipping houses are located in the south-central portion of AAAP. The shipping
house area (Series 229 Buildings) used to store propellant prior to shipment and consisted of 48
buildings, 13 of which are located on the land previously sold to Kimberly Glark. The remaining
35 buildings, located within the current AAAP boundary, comprise Study Area 17. Although
Study Area 17 overlaps into Area B, its contamination status was included in the Area A RI/FS
process.
411/1081594 19
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Soil samples from this study area were collected during initial RI efforts as well as after the
cleanup was complete. No organic contaminants were detected in the first sampling effort. The
second sampling effort (supplemental RI) determined the lead levels in the site-related soils
following the burning of lead (bullets) containing timbers. All of the soil samples collected as
part of the supplemental RI contained detectable levels of lead. The average lead concentration
in the soils was approximately 20 ppm and ranged from 8.83 to 130 ppm. Only four of the
samples exhibited a lead concentration greater than 30 ppm.
Only lead was detected at this study area. The levels of lead appear to be similar to the
concentrations across Area A, indicating that lead is not associated with a source. The primary
release mechanism for lead at this site would be via release to the atmosphere as particulate or
dust emissions. However, due to the degree of vegetative cover and relatively few areas of bare
soils, this migration pathway is not considered significant. The shipping houses were removed
during a remedial action completed in 1986.
5.7 New Trench Area (Study Area D) - Addressed by this Interim Action
During remedial activities conducted by Roy F. Weston, Inc. (Weston) in 1988, Study Area D
was identified. This area is approximately 2.9 acres located north of Study Area 11. Area D
was used for disposing of equipment and other general wastes.
Nitroaromatic compounds were detected in 3 of the 34 soil samples collected during the
Supplemental investigation. All three samples, which were collected from the 0- to 3-ft depth,
contained 246-TNT, with one sample containing a high concentration (13,900 ppm) of this
compound. Although the concentration of 246-TNT in the second sample was an order of
magnitude lower (1,400 ppm), the results suggest the presence of an area of high nitroaromatic
contamination. Of the three samples that contained 246-TNT, two also contained 135-TNB. The
presence of these contaminants is due to past disposal practices in the area.
Munitions and metallic chemicals were detected at this study area. The primary migration
pathways of the organics and metals detected in soil are fugitive dust or particulate emission. In
addition, the potential exists for chemicals in soil to migrate via surface runoff during periods of
heavy rainfall. The important fate and transport processes of the metals in the terrestrial
environment are adsorption/desorption, precipitation/dissolution, and speciation. The rate and
extent of these processes are influenced by pH, ionic strength, inorganic and organic ligands, and
redox conditions. The metals are expected to be in the adsorbed phase or in solution form and
be transported via surface runoff or leaching.
5.8 Disposal Area (Study Area E)
During remedial activities conducted by Weston in 1988, Study Area E was identified. This area
is less than 1 acre and is located north of Study Area 11 and east of Study Areas D and 12.
Study Area E was used for disposing of equipment and other general wastes.
No nitroaromatic contamination was detected in any of the soil samples collected as part of the
supplemental investigation. Lead and arsenic were detected in all 32 samples, and chromium was
also detected in 19 of the samples.
411/1081594 20
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Only metals were detected at this study area. The important fate and transport processes of the
metals in the terrestrial environment are adsorption/desorption, precipitation/dissolution, and
speciation. The rate and extent of these processes are influenced by pH, ionic strength, inorganic
and organic ligands, and redox conditions. The metals are expected to be in the adsorbed phase
or in solution form and be transported via surface runoff or leaching.
5.9 Number 2 Rubble Pile (Study Area F) and Henningsburg Area (Area G)
During remedial activities conducted by Weston in 1988, Study Areas F and G were identified.
These tracts were suspected to have been localized areas used for the disposal of equipment and
other general wastes. Study Area F is located near the Area A northwest boundary, and Study
Area G is located centrally near the Area A east boundary. The Weston investigation indicated
that the analytical results for these two areas were below detection limits.
5.10 229 Area (Study Area HP
During remedial activities conducted by Weston in 1988, Study Area H was identified. This area
was used for disposing of equipment and other general wastes and is located directly south of
Study Area 17.
Only lead was detected at this study area. The levels of lead appear to be similar to the
concentrations across Area A, indicating that lead is not associated with a source. The primary
release mechanism for lead at this site would be via the atmosphere as paniculate or dust
emissions. However, due to the degree of vegetative cover and relatively few areas of bare soils,
this migration pathway is not considered significant.
6.0 SUMMARY OF SITE RISKS
6.1 Introduction
In 1991, a supplemental RI was conducted at the request of EPA Region IV to verify the
effectiveness of the completed remedial actions in Area A. The supplemental RI and baseline RA
determined that soils at two study areas within Area A (Study Areas 12 and D) continue to
contain lead and explosives at unacceptable concentrations and, therefore, require further
remediation.
Risks due to site contamination were estimated for both the historical and post remediation data
and reported as pre- and post-remediation risks. Feasibility efforts were focused on the
remaining site contamination that was not addressed by the earlier remediation efforts. Identified
areas with excessive contamination were Study Areas 12 and D. The methods implemented to
estimate the risks are in accordance with the risk assessment guidance for CERCLA sites (EPA,
1989) and are presented in the following sections.
411/1081594 21
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6.2 COPCs
COPCs at the Superfund site are hazardous chemicals found to be present on site due to past site-
related activities. The COPCs identified during the supplemental RI efforts at the Area A of the
AAAP are:
Organic Chemicals Inorganic Chemicals
1,3-dinitrobenzene (13DNB) Arsenic
1,3,5-trinitrobenzene (135TNB) Chromium
2,4,6-trinitrotoluene (246TNT) Copper
2,4-dinitrotoluene (24DNT) Lead
2,6-dinitrotoluene (26DNT) Mercury
Nitrobenzene (NB) Nickel
Selenium
Silver
Zinc
Table 4 includes the statistical estimates of the exposure concentrations used for human and
ecological risk estimates.
6.3 Exposure Assessment
The human baseline RA evaluated three primary exposure scenarios for quantitative assessment of
the risks associated with potential exposure to site-related COPCs. While the current caretaker
scenario was not considered a significant exposure pathway, as the caretaker does not come into
contact with the study areas on a routine basis as would a future worker, to be most conservative
(to protect human health) it was assumed that a caretaker would have the same, and most likely
less exposure as a future worker. Thus, the future worker scenario also represents the current
caretaker scenario. The human exposure analysis evaluates the following three exposure
scenarios.
1. Future Residential
Exposure of residential adults and children to contaminated soil may occur via
direct contact, incidental ingestion and inhalation of fugitive dust.
The ROD is based on this exposure scenario because it provides the most
conservative potential exposure evaluation.
2. Property and/or wildlife maintenance worker
Exposure of maintenance workers to contaminated soil may occur via direct
contact, incidental ingestion, and inhalation of fugitive dust.
The potential may exist for the current caretaker to contact contaminated soils.
However, since the future worker scenario, which is a more conservative
exposure evaluation assuming standard default worker exposure (250
411/1081594 22
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AT AAAP AREA A
OF CONTAMINANTS OF POTENTIAL CONCERN (COPCS) AT STUDY AREAS 12 AND D
Study
Area Parameter
12 246TNT
AG
AS
CR
HG
NI
PB
SE
ZN
D 135TNB
246TNT
AG
AS
CR
CU
NI
PB
ZN
Detected Concentration
Average* Maximum
12.9
0.18
32.6
58.4
0.082
38.5
470
0.48
110
3.95
5.10E+03
0.57
24.2
47.1
3.37E+03
5.51
16.8
93.3
12.9
0.57
92.5
134
0.14
56.4
1.04E+04
0.54
202
7.13
1.39E+04
0.57
68.3
110
3.37E+03
5.51
89.8
227
Frequency
of
Detection
1/58
4/36
36/36
31/36
8/36
5/36
47/60
2/36
11/36
2/34
3/34
1/34
34/34
26/34
1/34
1/34
34/34
9/34
Best Est.
of the
Mean
0.60
0.020
32.6
51.2
0.037
10.8
97.2
0.14
44.0
0.33
7.04
0.029
24.2
37.5
128
7.74
16.8
32.8
Upper 95%
Confidence
Limit
0.76
0.03
38.5
60.1
0.04
14.3
195
0.17
58.4
0.41
40.4
0.057
28.8
44.3
294
10.2
20.9
44.1
Exposure
Concentration
0.76
0.03
38.5
60.1
0.04
14.3
195
0.17
58.4
0.41
40.4
0.057
28.8
44.3
294
10.2
20.9
44.1
Note: * = average of the detected concentrations.
Source: ESE, Inc.
411/1081594
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days/year for 25 years), did not result in any unacceptable risks or His, a
quantitative evaluation of the current caretaker exposure was not necessary.
3. Hunters
Exposure of hunters to contaminated soil may occur via direct contact,
incidental ingestion, and inhalation of fugitive dust. In addition, indirect
exposure to site chemicals may occur through consumption of contaminated
game.
This scenario was evaluated in the pre-cleanup RA. Since hunter exposure to
relatively higher levels of pre-cleanup chemical concentrations did not result
in any unacceptable risks or His and the current contaminant levels are lower
than those during the pre-remediated site conditions, this scenario was not
evaluated in the post-remediation RA.
Although occasional logging type activities may contribute to the worker exposure, the exposure
is random and insignificant compared to the property maintenance worker exposure. Therefore,
this scenario is not quantitated here; it is, however, discussed in detail in the RA.
Due to the nonvolatile nature of the site chemicals, inhalation of airborne vapors is not evaluated.
Table 5 presents the exposure pathways analyzed and the rationale for their selection at the site.
For the residential and worker exposure evaluation, EPA-recommended standard default values
were used for the majority of exposure factors. Site-specific information was used to develop
exposure parameters for the hunter scenario and some of the worker and residential exposure
factors. The exposure parameters used to estimate residential, worker, and hunter exposure are
listed in Table 6. The complete exposure factor development is included in the baseline RA
(ESE, 1992a).
The important ecological exposure routes are those pathways associated with soils or prey,
including the following:
1. Ingestion of contaminants retained on skin, fur, or feathers via preening,
burrowing, feeding, and other activities;
2. Ingestion of contaminated prey organisms;
3. Dermal contact; and,
4. Inhalation of windborne dusts.
Potential ecological exposure pathways are included in Table 7. Exposure concentrations used
for human and ecological intake estimates are included in Table 2.
411/1081594 24
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Table 5. SUMMARY OF THE EXPOSURE PATHWAYS ANALYZED FOR THE
QUANTITATIVE RA
Potentially Exposed
Population
Exposure Rate,
Medium and
Exposure Point
Pathway Selected
for Evaluation
Reason for Selection
or Exclusion
Future Land Use
Residential
Onsite Worker
Hunter
Hunter
Direct dermal, Yes
inhalation and
ingestion of COCs
in soil and sediment
Direct contact with Yes
COCs in soil and
sediments by
ingestion, inhalation,
and dermal contact
Contact with COCs in Yes
soil and sediment by
incidental ingestion,
dermal contact and
dust inhalation
Ingestion of COCs in Yes
the game meat
Area could be developed
into future residential area
If the area is used for
hunting purposes, the
wildlife maintenance worker
would be onsite regularly
Hunters may come in contact
with soils during the
sporting activities
Hunters could be exposed to
the chemicals present in
the meat of game animals
Source: ESE, Inc.
411/1081594
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Table 6. Exposure Factors Used to Calculate Residential, Worko; and Hunter Exposure to Soil Contaminants
Exposure
Factor
ABS (inorganics)
(organics)
AF
AT
BW
ED
EF
FC
Fl
IR (air)
(soil)
RPC
SA
Units
unitless
unitless
mg/cm2
days
kg
years
days
kg/mg
unitless
m3/day
mg/day
mg/m3
cm2
Non
Receptor-
Specific
0.001
0.01
1
-
-
-
-
1E-06
1
-
0.027
-
Receptor-Specific
Residential
Adult
-
-
10,950
70
30
350
-
-
20
100
-
5,314
Child
-
-
2,190
15
6
350
-
-
25
200
-
2,484
Lifetime
-
-
25,550
#
#
350
-
-
21
#
-
4,748
Worker
Care.*
-
-
25,550
70
25
250
-
20
50
2,679
Noncarc.*
-
-
9,125
70
25
250
-
-
20
50
-
2,679
Hunter
Care.*
-
-
25,550
70
30
24
-
-
20
50
-
1,506
Noncarc.*
-
-
10,950
70
30
24
-
-
20
50
-
1,506
Note: ABS = chemical-specific absorption factor.
AF = soil to skin adherence factor.
AT = period of time over which exposure is averaged.
BW = body weight.
ED = exposure duration.
EF = exposure frequency.
FC = conversion factor.
Fl = fraction of soil from contaminated source.
IR = ingestion/inhalatibn rate.
RPC = respirable particulate concentration in air.
SA = skin surface area available for soil contact.
'Carcinogenic (care) and noncarcinogenic (noncarc) intakes are calculated using different averaging times (AT).
# Lifetime soil ingestion is a time-weighted value because soil ingestion rate is highly dependent on age and body weight.
Source: ESE.
-------
6.4 Toxicitv Assessment
The carcinogenic slope factors (CSFs) and the reference doses (RfDs) for the COPCs at AAAP
Area A are included in Table 3. These values, in association with the exposure scenarios
described in Sec. 6.3, were used to quantify the risks and His.
CSFs have been developed by EPA's Carcinogenic Assessment Group for estimating excess
lifetime cancer risks associated with exposure to potentially carcinogenic chemicals of concern.
CSFs, which are expressed in units of (mg/kg-day)'1, are multiplied by the estimated intake of a
potential carcinogen, in mg/kg-day, to provide an upperbound estimate of the excess lifetime
cancer risk associated with exposure at that intake level. The term "upperbound" reflects the
conservative estimate of the risks calculated from the CSF. Use of this approach makes
underestimation of the actual cancer risk highly unlikely. CSFs are derived from the results of
human epidemiological studies or chronic animal bioassays to which animal-to-human
extrapolation and uncertainty factors have been applied (e.g., to account for the use of animal
data to predict effects on humans).
EPA has developed RfDs for indicating the potential for adverse health effects from exposure to
chemicals exhibiting noncarcinogenic effects. RfDs, which are expressed in units of mg/kg-day,
are estimates of lifetime daily exposure levels for humans, including sensitive individuals.
Estimated intakes of chemicals from environmental media (e.g., the amount of a chemical
ingested from contaminated drinking water) can be compared to the RfD. RfDs are derived from
human epidemiological studies or animal studies to which uncertainty factors have been applied
(e.g., to account for the use of animal data to predict effects on humans). These uncertainty
factors help ensure that the RfDs will not underestimate the potential for adverse noncarcinogenic
effects to occur.
6.5 Risk Characterization
The risk characterization step of the RA estimates the carcinogenic and noncarcinogenic hazards
from chemicals by combining the information from the exposure estimates and the toxicity
information for each chemical. Excess lifetime cancer risks are determined by multiplying the
intake level with the CSF (Table 3). These risks are probabilities that are generally expressed in
scientific notation (e.g., 1 x 10"4 or 1E-04). A cancer risk of 1 x 10"4 means that one additional
person out of 10,000 is at risk of developing cancer as a result of site-related exposure to a
carcinogen over a lifetime under the specific exposure conditions at a site, if site is not cleaned
up.
Potential concern for noncarcinogenic effects of a single contaminant in a single medium is
expressed as the hazard quotient (HQ) for human exposure or environmental quotient (EQ) for
environmental exposure (or the ratio of the estimated intake derived from the contaminant
concentration in a given medium to the contaminant's RfD). By adding the HQs for all
contaminants within a medium or across all media to which a given population may reasonably be
exposed, the HI can be generated. The HI provides a useful reference point for gauging the
potential significance of multiple contaminant exposures within a single medium or across media.
411/1081594 27
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Table 7.
POTENTIAL ECOLOGICAL EXPOSURE PATHWAYS FOR ALL STUDY AREAS IN AREA A
Medium and
Exposure Pathway
Study Area
11
12
13
14
15
17
D
H
Surface Water
Dermal
Ingestion
Sediments
Dermal
Ingestion
Soils
Dermal
Ingestion
Inhalation
Food Web Predalion
Terrestrial
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Source: ESE, Inc.
411/1081594
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The risk/Hi or EQ is calculated for each exposure pathway at each study area. Any study area
exceeding these levels was further considered for remedial action in the FS. A resultant risk
greater than 1 in 10,000 or an HI or EQ greater than 1 is interpreted to mean that an adverse
impact to human health and the environment may occur. A summary of the human health risks
exceeding these values is included in Table 8. A summary of the ecological health risks is in
Table 9.
For Study Area 12 in the Area A Soil OU, carcinogenic COPCs present a risk of 1.3 in 10,000,
which is above the upperbound acceptable risk level of 1 in 10,000. Most of the risk is from
arsenic under residential exposure conditions. The total HI for a child resident is 6.4, primarily
from arsenic and chromium.
EQs at Study Area 12 exceeded 1 for lead and chromium. The soils contain lead at a maximum
concentration of 10,400 ppm. Only the risk from lead may suggest an adverse impact to the
environment. EQs for 246TNT also are greater than 1.0, but the data distribution and the lack of
significant evidence of exposure suggests that adverse impacts would not be anticipated.
Therefore, lead, but not 246TNT, may pose an unacceptable hazard to nonhuman receptors at
Study Area 12. Lead should be remediated to EPA's health-based guidance level of 500 mg/kg;
this level was recommended in August 1991 by EPA's Office of Solid Waste and Emergency
Response which is an update of the Technical Directive #9355.4-02 entitled "Interim Guidance on
Establishing Soil Lead Cleanup Levels at Superfund Sites" (September 1989).
For Study Area D in the Area A Soil OU, the cumulative excess cancer risk to adults was below
the upperbound acceptable risk level of 1 in 10,000. The organic contaminant 246-TNT
contributes to overall risk. The noncarcinogenic HI for a future child resident at Study Area D is
6, primarily due to the presence of 246TNT, arsenic, and chromium. The HI for a future child
resident is 5 due to the presence of arsenic and chromium. EQs for 246TNT exceed 1, and
adverse effects to the environment could potentially occur. However, a study of 246TNT and its
metabolites concludes that exposure from human consumption of deer, quail, and rabbit is
minimal because contaminants were not present above analytical detection limits. The cleanup
values calculated for 246TNT and lead are presented in the summary section (Sec 6.7).
6.6 Uncertainty Analysis
Uncertainty is inherent in the risk estimation process due to the assumptions required to estimate
the risks. The following are some of the uncertainties observed in the RA at Area A:
1. Available soil sampling information is limited.
2. Background sampling information for the inorganic chemicals is not available.
3. The assumptions EPA used to develop the toxicity factors (e.g., CSFs) are subject
to high uncertainty due to the assumptions used.
4. The toxicity factors for chromium do not represent environmental exposure
conditions, and the conservative assumptions used for risk estimates consider that
all chromium is in the more toxic hexavalent form.
411/1081594 29
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Table 8. SUMMARY OF POTENTIAL RISKS AND HIS EXCEEDING TARGET VALUES FOR SOIL
EXPOSURE AT AAAP AREA A - POST-CLEANUP
Contamination Lifetime Resident
Area Analyte Risk
Child Resident
HI
12
D
246TNT
AS
CR
PB
TOTAL
CR
AS
246TNT
135TNB
CU
PB
TOTAL
4E-08
1E-04
8E-06
6E-06
9E-05
2E-06
NA
NA
*
1E-04
3E-03
5
2
4
1
1
0.1
0.1
Note: * Lead was detected at levels above EPA's guidance health-based level of 500 mg/kg.
Source: ESE, Inc.
411/1081594
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Table 9.
ECOLOGICAL RISK VALUES FOR TERRESTRIAL ANIMALS. AAAP AREA A POST-CLEANUP AAAP AREA A POST CLEANUP
Conpouru
246TNT
246TNT
246TNT
246TNT
246TNT
246TNT
246TNT
240NT
240NT
24DNT
240NT
24DNT
260NT
135TNB
13DNB
130NB
AS
AS
CRVI
CRVI
CRVI
FE
FE
FE
PB
PB
PB
PB
HG
HG
HG
AG
AG
AG
B2EHP
B2EHP
BZEHP
B2EHP
B2EHP
OPA
Species Kane
Cams famillaris
Canis fani Marls
Hus spp.
MLB spp.
Mus spp.
Sylvilagus spp.
Sylvilagus spp.
Canis familiaris
Canis familiaris
Mus spp.
Mus spp.
Rattus rattus
Mus spp..
Rattus rattus
Rattus rattus
Rattus rattus
Mus spp.
Mus spp.
Canis familiaris
Rattus rattus
Sylvilagus spp.
Cavia procellus
Mus spp.
Rattus rattus
Mus spp.
Zenaida macroura
Canis familiaris
Colinus spp.
Lurbricus terrestris
Cavia procellus
Mus spp.
Rattus rattus
Amus platyrhynchos
Callithrix spp.
Canis familiaris
Mesocricetus auratus
Rattus rattus
Rattus rattus
Cciinin Mane
Dog
Dog
Mouse
Mouse
Mouse
Rabbit
Rabbit
Dog
Dog
Mouse
Mouse
Rat
Mouse
Rat
Rats
Rats
Mouse
Mouse
Dogs
Rats
Rabbits
Guinea pigs
Mice
Rats
Plants
Plants
Mouse
Mourning Dove
Dog
Bobuhite
Earthworm
Guinea pigs
Mouse
Rats
Mallard Duck
Marmoset monkey
Dogs
Hamsters
Rats
Rats
Status
LQEL
NOEL
Acute
Chronic
NOEL
Acute
Chronic
Chronic
NOEL
Acute
NOEL
NOEL
Acute
Acute
Acute
Chronic
FETOXIC
NOEL
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
NOEL
NOEL
NOEL
NOEL
NOEL
NOEL
ID
NOEL
Area 11 Area
Maxima Mean Maximo
0.32250
1.29000
0.00019
0.88966
0.86000
0.00137
25.80
-\
0.00006 0.00006
0.04818 0.04818
0.23125
1.85000
0.06700
0.013(0
7.85463
83.20
26.00
126.06
2.88889
0.00507
0.00026
0.17975
0.00021
0.00313
0.00026
>
12
Meen
0.32250
1.29000
0.00019
0.88966
0.86000
0.00137
25.80
0.08144
0.65150
0.02921
0.00584
3.42416
3.75945
1.17483
5.69614
0.13054
0.00294
0.00015
0.10428
0.00006
0.00097
0.00008
Area 17 Area D Area
Maxima Mean Maxiui Mean Maxiui
.06675 .06675 0.18200
.53400 .53400 1.45600
.02075 .02075 0.04725
.00415 .00415 0.00945
2.43259 2.43259 5.53927
1.04000 0.15662 6.66400 6.66400 2.28000
0.32500 0.04894 2.08250 2.08250 0.71250
1.57576 0.23730 10.10 10.10 3.45455
0.03611 0.00544 .23139 .23139 0.07917
0.00371
0.00019
0.13165
0.00010
0.00149
0.00012
E
Mean
0.05696
0.45568
0.02328
0.00466
2.72872
0.21584
0.06745
0.32703
0.00749
0.00258
0.00013
0.09128
0.00005
0.00071
0.00006
Area H
Maxim* Mean
0.11520 0.09436
0.03600 0.02949
0.17455 0.14297
0.00400 0.00328
NOTE:
The ruiber of decimal places presented in the values above was determined to ensure that at least one non-zero nuneral was displayed, and are not intended to represent
significant digits.
Source: ESE, Inc.
411/1081594
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5. Ecotoxicity data are not available for nonhuman receptors. Therefore, laboratory
data were extrapolated to represent the ecological receptors contributing to a large
uncertainty.
Perhaps the most uncertainty in the risk evaluations stems from the exposure assumptions. While
the current exposure pathway is considered insignificant compared to the future exposure
pathways, the current exposure pathway was assumed to be equivalent to the future worker
exposure. In addition, intake assumptions, chemical-specific absorption coefficients, individual
variation in the intake, absorption, and the expression of the toxicity contribute significantly to
the uncertainty in the risk estimates. Therefore, actual exposure to human and ecological
receptors is unknown. The most significant uncertainty at Area A is related to the risk estimates
and the underlying assumptions regarding exposure to chromium. Arsenic and chromium in
Study Areas 12, D, and E are widely distributed. Arsenic was detected in 100 percent of the
samples tested. Arsenic was detected in 36/36 samples at Study Area 12, 34/34 samples at Study
Area D, and 36/36 samples at Study Area E. Chromium is present in greater than 70 percent of
the samples. Chromium was detected at Study Area 12 in 31/36 (86 percent) samples, at
Study Area D in 26/34 (76 percent) samples, and at Study Area E in 25/36 (70 percent) samples
(App. I of RA report, ESE, 1992a). Details of the uncertainty associated with exposure to
chromium can be found in the baseline RA report (ESE, 1992a).
6.7 Summary
The soils of concern in the Area A Soil OU are located in Study Areas 12 and D. These soils
contain elevated levels of inorganics (i.e., arsenic, chromium, and lead) and explosives. The
chemical-specific remediation level (RL) for arsenic is background, while for chromium and
246TNT, the RL was developed based on standard default exposure assumptions. The RL for
lead was adopted from available EPA region-wide guidance, which indicates that lead in soil at
Superfund sites be remediated to 500 to 1,000 mg/kg for residential sites. Table 10 lists the
final COCs present at Study Areas 12 and D. The summary of the results is as follows:
Study Area 12—Lead was detected in four samples at Study Area 12; the concentrations varied
between 232 and 10,400 ppm. A toxicity criterion was not available for lead to obtain a risk or
an HI value. However, based on the EPA guidance, a health-based remediation level of 500 ppm
in soil is recommended for residential land use of Superfund sites. As Area A has been sold to
private ownership, the future unlimited use may include residential use of the land.
Arsenic exceeds background concentrations and the purely health-based cleanup level (0.37
mg/kg for a lifetime exposure) is below background (11.7 mg/kg, maximum concentration of AS
in background). This is a sitewide occurrence which will be addressed in the final ROD for Area
A. The exceedance of the HI for chromium is due to assumption that chromium is in the most
toxic hexavalent form and that inhalation to dust is considered a significant pathway. Using
standard default exposure assumptions for a residential child, taking into account that ingestion of
soils is the primary exposure route to a child, a health-based RL of 390 mg/kg has been
calculated. Because the maximum on-site concentrations as well as the exposure concentrations
of chromium are well below this concentration, and the site is vegetated and thus, not amendable
to producing dust 350 days per year, the current site concentrations do not suggest that chromium
requires remediation. The estimated volume of lead-contaminated soil is approximately
3,800yd3.
411/1081594 32
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Table 10. SUMMARY OF CHEMICAL PARAMETERS DETECTED IN AREA A SOILS AT
CONCENTRATIONS EXCEEDING CLEANUP CRITERIA
Study Sample Depth
Area Number (ft)
12 12-11 0.5
12-9 0.5
12-16 0.5
12-9 2.5
All samples
D D-8 0.5
Pj 2.5
All samples
Chemical
Lead
Lead
Lead
Lead
Lead
246TNT
246TNT
246TNT
Chemical Chemical-Specific
Concentration Remediation Level
(mg/kg) (mg/kg)
1,320 200
10,400 200
232 200
8.710 200
5,165.5 (Average)
13,900 33.67
1.400 33.67
7,650.0 (Average)
Note: All samples taken on Aug. 1, 1991.
mg/kg = milligrams per kilogram.
Source: ESE.
411/1081594
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Study Area D~The explosive 246TNT was detected in two samples at Study Area D; the
concentrations varied between 1,400 and 13,900 ppm. The resultant risk for adult residents,
based on the 95-percent upper confidence level (UCL95%) concentration of 40.4 ppm, is 2.2 in a
million and the contributing HI based on exposure concentration for child residents is 1.2. The
estimated volume of explosives-contaminated soil is approximately 5 yd3. Arsenic exceeds
background concentrations and the purely health-based clean-up level (0.37 mg/kg for a lifetime
exposure) is below background (11.7 mg/kg, maximum concentration of AS in background).
This is a sitewide occurrence which will be addressed in the final ROD for Area A. The
exceedance of the HI for chromium is due to assumption that chromium is in the most toxic
hexavalent form and that inhalation to dust is considered a significant pathway. Using standard
default exposure assumptions for a residential child, taking into account that ingestion of soils is
the primary exposure route to a child, a health-based RL of 390 mg/kg has been calculated.
Because the maximum on-site concentrations as well as the exposure concentrations of chromium
are well below this concentration, and the site is vegetated and thus, not amendable to producing
dust 350 days per year, the current site concentrations do not suggest that chromium requires
remediation.
Concentrations of 246TNT at Study Area D should be reduced to levels that are protective of
human health and the environment. Using standard default lifetime residential exposure
assumptions, a RL of 21 mg/kg for 246TNT has been calculated based on a target cancer risk
level of 1 in a million lower bound of EPA's acceptable cumulative risk range of 1 x 10"6 to 1 x
104.
Based on the results of the supplemental RI/RA/FS, the significant COCs at Study Areas 12 and
D within the Area A Soil OU are lead and explosives (246TNT). The remediation levels for
Study Areas 12 and D are as follows:
1. Lead-contaminated soils at Study Area 12 will be remediated to achieve a risk-based
soil remediation level of 500 mg/kg.
2. 246-TNT contaminated soils at Study Area D will be remediated to achieve the risk-
based soil 246-TNT concentration of 21 mg/kg.
Achieving the remediation levels at these areas would result in protection of human health and the
environment, as the total risk from Study Area 12 and D COCs will be at or below one in a
million cancer risk level, a noncarcinogenic HI would be at or below a value of 1, and an EQ
would be at or below a value of 1. Table 11 presents the assumptions and calculations of the
remediation levels for COC.
7.0 DESCRIPTION OF ALTERNATIVES
Four interim remedial action alternatives have been developed for the contaminated soils in the
Area A at AAAP. Alternatives 1A, 1C, and ID involve excavation of approximately 3,800 yd3
of lead-contaminated soil from Study Area 12 and 5 yd3 of explosives-contaminated soil from
Study Area D. Alternative IE presents the no-action alternative. A fifth alternative, Alternative
IB, was assembled in the supplemental RI/FS but was not retained beyond the preliminary
411/1081594 34
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Table 11. ASSUMPTIONS USED IN CALCULATING REMEDIATION LEVELS FOR COCS
For carcinogenic effects (i.e. arsenic, and 246 TNT) used the following equation:
77? x AT
Where:.
TR = target risk (10^ unitless).
AT,^ = averaging time for carcinogenic exposures (25,550 days).
EFra = exposure frequency (350 days/year).
CFW = soil conversion factor (10s mg/kg).
= chemical-specific oral cancer slope factor [(mg/kg/day)'1].
= soil ingestion factor, age adjusted (114.3 mg-yr/kg-day).
For noncarcinogenic effects (i.e. chromium) used the following equation:
Where:
THQ = target hazard quotient (1, unitless).
R®o«i = chemical-specific oral reference dose (mg/kg/day).
BWC = body weight, age 1-6, (15 kg).
AT^. = averaging time for noncarcinogenic exposures (EDc x 365 days/yr).
EF^. = residential exposure frequency (350 days/year).
EDC = exposure duration, age 1-6 (6 yr).
IRSC = soil ingestion factor, age 1-6 (200 rag/day).
C£K — soil conversion factor (10* mg/kg).
411/1081594
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screening of alternatives. A brief description of the retained early remedial action alternatives is
presented in the following sections.
7.1 Alternative 1A—Excavation and On-site Solidification/Stabilization of Contaminated
Soil. On-site Disposal
Alternative 1A includes study area preparation followed by the excavation of all contaminated
soils. No federal or state chemical-specific ARARs regulate cleanup; however, remediation
levels have been established to meet health-based cleanup levels determined to be protective of
human health. Approximately 5 yd3 of 246TNT-contaminated soil in Study Area D will be
excavated to meet the remediation level of 21 mg/kg and 3,800 yd3 of lead-contaminated soil in
Study Area 12 will be excavated to meet the remediation level of 500 mg/kg. Verification
sampling will be performed to ensure that all soils exceeding the contaminant remediation levels
have been removed.
Contaminated soils will be classified according to the Resource Conservation and Recovery Act
(RCRA) [40 Code of Federal Regulations (CFR) Part 261] to determine if soils are a hazardous
waste. Excavated soils would then be transported to a staging area for treatment by
solidification/stabilization (if required) to comply with the land disposal restrictions in accordance
with RCRA (40 CFR 262 and 264) and the State of Alabama regulations (Code of Alabama, Title
22, Chapters 27, 28, and 30). Stabilized material will be analyzed for lead and explosives to
verify compliance with the following treatment standards:
Lead-contaminated materials that result in a toxicity characteristic leaching
procedure (TCLP) extract in excess of 5 milligrams per liter (mg/L) are considered
hazardous. Explosives-contaminated materials that are ignitable or reactive are also
considered hazardous. Solidified/stabilized material must not be ignitable or
reactive, and must not exhibit a lead concentration greater than 5 mg/L in the
TCLP to be disposed of.
Stabilized material meeting these criteria will be placed at an on site designated area in Area B.
Clean soil will be used to backfill the excavations in Area A. The costs for excavating the
contaminated soils and treating (by solidification/stabilization) are presented in the following cost
estimate.
Estimated Construction Cost $ 82,355
Estimated Operation and Maintenance (O&M) Cost $ 303,600
Estimated Total Present-Worth Cost, including
Engineering and Contingency $ 414,779
Approximate Duration 1-2 weeks
7.2 Alternative IC—Excavation and OFf-site Disposal of Contaminated Soil
Alternative 1C includes study area preparation followed by excavation of all contaminated soils.
No federal or state chemical-specific ARARs regulate cleanup; however, remediation levels have
been established to meet health-based cleanup levels determined to be protective of human health.
Approximately 5 yd3 of 246TNT-contaminated soil in Study Area D will be excavated to meet the
remediation level of 21 mg/kg and 3,800 yd3 of lead-contaminated soil in Study Area 12 will be
411/1081594 36
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excavated to meet the remediation level of 200 mg/kg. Verification sampling will be performed
to ensure that all soils exceeding the contaminant remediation levels have been removed.
Contaminated soils will be classified according to RCRA (40 CFR Part 261) to determine if soils
are a hazardous waste. Excavated soils would then be transported to an approved hazardous
waste landfill facility in Emelle, AL, for disposal in accordance with RCRA (40 CFR 262 and
264) and the State of Alabama regulations (Code of Alabama, Title 22, Chapters 27, 28, and 30).
Excavated soils will be analyzed for lead and explosives to verify compliance with the following
standards:
Lead-contaminated materials which result in a TCLP extract in excess of 5 mg/L
are considered hazardous. Explosives-contaminated materials that are ignitable or
reactive are also considered hazardous. Excavated soils must not be ignitable or
reactive, and must not exhibit a lead concentration greater than 5 mg/L in the
TCLP extract to be disposed of without further treatment.
Stabilized material meeting these criteria will be placed in the approved hazardous waste landfill
without further treatment. The excavations in Area A will be backfilled with clean soil.
The costs for excavating, transporting, and disposing of the contaminated soils in a hazardous
waste landfill are presented in the following cost estimate. Implementation of this alternative
assumes that the contaminated soils will pass TCLP requirements for lead and not exhibit the
characteristics of ignitability and reactivity for explosives. The costs for this alternative do not
include treatment by solidification/stabilization if the soils do not meet these requirements.
Estimated Construction Cost $ 1,007,453
Estimated O&M Cost None
Estimated Total Present-Worth Cost, including
Engineering and Contingency $ 1,360,061
Approximate Duration 1-2 weeks
7.3 Alternative ID—Excavation and Stockpiling of Contaminated Soil in Area B RMCSs
Alternative ID includes study area preparation followed by excavation of all contaminated soils.
No federal or state chemical-specific ARARs regulate cleanup; however, remediation levels have
been established to meet health-based cleanup levels determined to be protective of human health.
Approximately 5 yd3 of 246TNT-contaminated soil in Study Area D will be excavated to meet the
remediation level of 21 mg/kg and 3,800 yd3 of lead-contaminated soil in Study Area 12 will be
excavated to meet the remediation level of 200 mg/kg. Verification sampling will be performed
to ensure that all soils exceeding the contaminant remediation levels have been removed.
Contaminated soils will be classified according to RCRA (40 CFR Part 261) to determine if soils
are a hazardous waste. Excavated soils will then be transported to a temporary containment
structure in Area B. The soil will not be transported off-site at any time during hauling. The
excavated soil will remain in storage until the implementation of remedial actions for the
Stockpile Soils Area OU. At that time, the contaminated soils of Study Areas 12 and D within
the Area A Soil OU will be removed from the temporary storage structures and treated by
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incineration, followed by solidification/stabilization (if required), or stabilization only (if
applicable) along with the stockpiled soils.
Contaminated soils will be transported to an on-site thermal treatment unit in Area B for
incineration. Treated material will be analyzed for explosives and lead to verify compliance with
the treatment criteria described in Sec. 10.0. Particulate emissions from the incinerator will be
managed through the use of a standard air emissions control system. Routine analysis of stack
gases will be conducted to ensure the processes are operating efficiently and within acceptable
criteria. The explosives will be destroyed during the incineration process. If lead concentrations
in the soil, the treated soil or fly ash exceed the allowable regulatory standards, that material will
be solidified/stabilized in compliance with the Land Disposal Restrictions in accordance with
RCRA (40 CFR 262 and 264) and the State of Alabama regulations (Code of Alabama, Title 22,
Chapters 27, 28, and 30).
Treated material will be placed at an on site designated area in Area B. The excavations in
Area A will be backfilled with clean soil. The on-site incinerator will be removed from Area B
upon completion of the project.
The cost for excavating, transporting, and treating the Area A soils is presented in the following
cost estimate as estimated construction costs. No costs are included for
mobilization/demobilization of the incinerator since remediation will take place at the same time
as the Stockpile Soils Area OU and these costs have already been accounted for in the Stockpile
Soils Area OU ROD. Also, since the selected alternative can be completed in a short time
period, no periodic O&M costs associated with the incinerator were included.
Estimated Construction Cost $ 1,215,024
Estimated O&M Cost None
Estimated Total Present-Worth Cost, including
Engineering and Contingency $ 1,640,282
Approximate Duration 1-2 weeks
7.4 Alternative IE—No Action
The no-action alternative is required to be included as stipulated by CERCLA/SARA. No
remedial action will be performed in this alternative. The no-action alternative is a baseline
against which other alternatives can be evaluated. Under this alternative, contaminated soil
would remain in place in the identified study areas. The risks from the COCs would remain.
No cost is associated with this alternative.
8.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
8.1 Threshold Criteria
Overall Protection of Human Health and the Environment
Upon completion of Alternatives 1A, 1C, and ID, the contaminant concentrations in the soils in
Study Areas 12 and D within the Area A Soil OU would be reduced to levels that are protective
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of human health and the environment through excavation, treatment, and disposal outside of
Area A of contaminated soils from the Study Areas. Alternative IE would not be protective of
human health or the environment since contaminants would be left in the soils, and risks to the
community, workers, and the environment would remain.
Compliance with ARARs
No federal or state chemical-specific ARARs regulate implementation of any of the alternatives.
Soils will be remediated according to health-based cleanup levels determined to be protective to
human health and the environment. Completion of Alternatives 1A, 1C, and ID would achieve
the health- and risk-based cleanup levels. With Alternative 1A, the contaminated soils would be
treated and disposed of on site in a designated backfill area in Area B. Although implementation
of this alternative does not reduce soil contaminants, remediation levels are met by disposing of
treated soils outside of Area A. With Alternative 1C, the contaminated soils would be removed
and transported to an off site location and disposed of. With Alternative ID, the contaminants
would be removed from Area A and transported to Area B for temporary storage and subsequent
treatment. Alternative IE would not achieve the remediation levels since the contamination
would not be removed or destroyed.
The following location-specific ARARs may be applicable within AAAP:
1. Within 100-year floodplain
RCRA: 40 CFR 264.18(b)~Facility must be designed, constructed, operated,
and maintained to avoid washout by a 100-year flood.
2 Within floodplain
Executive Order 11988; 40 CFR 6, App. A: Floodplain Management--
Requires actions to avoid adverse effects, minimize floodplain destruction,
restore and preserve natural and beneficial values, and minimize impact of
floods on human safety, health and welfare.
3. Wetland
Executive Order 11990; 40 CFR 6, App. A: Protection of Wetlands-Requires
action to avoid adverse impact, minimize potential harm, and to preserve and
enhance wetlands to the extent possible.
4. Within an area affecting stream or river
Fish and Wildlife Coordination Act [16 United States Code (USC) 661 et
seg.]--Must take action to protect affected fish or wildlife resources, and
prohibits diversion, channeling, or other activity that modifies a stream or
river and affects fish or wildlife.
5. Critical habitat upon which endangered or threatened species depends
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Endangered Species Act of 1973 (16 USC 1531 et sea.); 50 CFR 402-
Requires action to conserve endangered or threatened species. Must not
destroy or adversely modify critical habitat.
However, none of the location-specific ARARs are expected to apply to implementation of any of
the alternatives being evaluated since all activities associated with the Area A Soil OU
remediation would be conducted in areas located away from sensitive environment (i.e., the
river, 100-year floodplain, or critical habitat).
The following action-specific ARARS may apply to implementation of these alternatives,
excluding Alternative IE (No Action):
1. Clean Air Act (CAA)
40 CFR Part 50: National Primary and Secondary Ambient Air Quality
Standards—Establishes standards for ambient air quality to protect public
health and welfare.
40 CFR Part 61: National Emission Standards for Hazardous Air Pollutants-
Sets emission standards for designated hazardous pollutants.
2. RCRA
40 CFR Part 261: Identification and Listing of Hazardous Waste—Provides
guidelines for classifying wastes as hazardous waste.
40 CFR Part 262: Standards Applicable to Generators of Hazardous Waste-
Establishes standards for generators of hazardous waste.
40 CFR Part 264: Standards for Owners and Operators of Hazardous Waste
Treatment, Storage, and Disposal Facilities-Establishes minimum national
standards which define the acceptable management of hazardous waste for
owners and operators of facilities which treat, store, or dispose of hazardous
waste.
3. Alabama Administrative Code (AAC)
Chapters 13-1 through 13-7: Alabama Solid Waste Management Regulations-
Establishes minimum criteria for the processing, recycling and disposal of
solid wastes and the design, location, and operation of solid waste disposal
facilities.
Chapters 335-3-1 through 335-3-14: Alabama Air Pollution Control Rules and
Regulations—Sets emission standards and establishes permitting requirements
for air pollutants.
Chapter 335-14-5.15(4)(a)l: Performance Standards for Incinerators—Provides
standards for the performance of incinerators. Incinerators treating hazardous
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wastes must provide at least 99.99 percent destruction efficiency for each
principal organic hazardous constituent.
4. Code of Alabama
Title 22, Chapter 27: Alabama Solid Waste Act-Establishes a statewide
program to provide for the safe management of non-hazardous wastes.
Title 22, Chapter 28: Alabama Air Pollution Control Act of 1971--Provides
for a coordinated statewide program of air pollution prevention, abatement,
and control.
Title 22, Chapter 30: Alabama Hazardous Waste Management and
Minimization Act-Establishes a statewide program to provide for the safe
management of hazardous wastes, including hazardous waste generation,
transportation, and land disposal.
5. ADEM
Chapter 14-1: Alabama Hazardous Waste Management Regulations--
Establishes standards which define the acceptable management of hazardous
waste for owners and operators of facilities which treat, store, or dispose of
hazardous waste.
8.2 Primary Balancing Criteria
Short-Term Effectiveness,
Upon completion of remedial activities, Alternatives 1A, 1C, and ID would satisfy the remedial
action objectives. Residual soil concentrations in Study Areas 12 and D within the Area A Soil
OU would be below the remediation levels. No significant risks to the community, the workers
implementing remedial actions, or the environment are expected during implementation of these
three alternatives, provided that proper safety precautions are taken. During the excavation phase
of these alternatives, appropriate precautions, such as the construction of surface runoff controls
and the proper containment and covering of excavated soils, would reduce impacts to the
environment. During the transportation phase, appropriate RCRA and DOT guidelines for
transporting hazardous wastes would be followed to reduce impacts to the environment and the
community. Primary risks to workers would be reduced by wearing protective clothing,
designating exclusion zones for excavation areas, and adhering to proper decontamination
procedures.
It is expected that each of these alternatives could be completed in less than 2 weeks. Based on a
comparison of these three alternatives, no difference exists in their short-term effectiveness.
Alternative IE would present unacceptable risks to human health and the environment since no
remediation of the contaminated soils would occur; therefore, this alternative would not be
effective in the short term.
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Long-Term Effectiveness and Permanence
Alternatives 1A, 1C, and ID would be effective in reducing the long-term risk of exposure at
Study Areas 12 and D within Area A. With these alternatives, the magnitude of residual risks
will be removed as all of the contaminants are excavated and removed from Study Areas 12 and
D within Area A. No treatment residuals or untreated wastes would remain in Study Areas 12
and D within Area A following completion of this interim action. Alternative 1A would be
effective due to the removal of the contamination sources from Study Areas 12 and D within
Area A and subsequent treatment of the contaminated soils in Area B. Alternative 1C would
facilitate the removal of contaminated soils from Study Areas 12 and D within Area A for off-site
disposal with no further treatment. Although Alternative ID would not result in immediate
treatment of the soil contaminants, the direct exposure pathways would be eliminated until the
soils could be treated along with the Stockpile Soils Area OU soils. No long-term management
of treatment residuals would be required. The effectiveness of the treatment methods has been
demonstrated for similar wastes. Alternative IE would not be effective in the long term since the
contamination sources would remain intact, yielding no reduction in the unacceptable pathways or
associated risks.
Reduction of Contaminant MTV
Alternative 1A would reduce the mobility of the contaminants of concern in Study Areas 12 and
D within the Area A Soil OU; however, soil toxicity will not be reduced and the total volume of
contaminated material is expected to increase by approximately 30 percent. Alternatives 1C and
ID would reduce on-site MTV within Study Areas 12 and D within Area A. However, overall
toxicity or volume of contaminated material would not be reduced since the soil would only be
transferred from one location to another. Under Alternative ID, treatment of die contaminated
soils along with the Stockpile Soils Area OU would result in a significant decrease in toxicity and
a slight decrease in volume of material. Because the contaminants in the soils would not be
destroyed, removed, or treated under Alternative IE, the MTV of the contaminants would remain
unchanged.
Implementability
Alternatives 1A, 1C, ID, and IE are technically and administratively feasible. Alternatives 1A,
1C, and ID are all implementable, with required labor, equipment, and materials available from
various suppliers near AAAP. Alternative 1A would be more difficult to implement than
Alternatives 1C or ID since this alternative requires special equipment and operators as well as
additional site preparation and system mobilization prior to remediation. Alternative ID would
be the most easily implementable since this alternative does not require off-site transportation,
and treatment of the contaminated soils could be performed when the treatment system for the
Stockpile Soils Area OU has already been mobilized. No remedial actions would be implemented
for Alternative IE.
Cost
The total present-worth costs of remediation, based on 1992 unit costs, are $415,000 for
Alternative 1A; 51,360,000 for Alternative 1C; and $1,640,000 for Alternative ID. These costs
include construction costs, O&M costs, engineering, and contingency fees. Additionally, the cost
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for Alternative ID includes treatment of the contaminated soils at the appropriate time when
stockpiled soils are being treated. No cost is associated with Alternative IE.
8.3 Modifying Criteria
ADEM/EPA Acceptance
EPA and ADEM have concurred with the choice of Alternative ID.
Community Acceptance
Public comments on the selected remedial action were minimal. The majority of the comments
requested additional information on the types, volumes, and locations of contaminants; the safety
of workers and residents; and the timely implementation of the remedial action. All of these
comments have been addressed. The public appears to have no concerns about the
implementation of the selected remedy.
9.0 SELECTED REMEDY AND REMEDIATION LEVELS
The selected alternative (Alternative ID) calls for implementing an interim remedial action to
protect human health and the environment from the contaminated soil in Study Areas 12 and D
within the Area A Soil OU at AAAP. This action is an interim action for only the contaminated
soils in Study Areas 12 and D within the Area A Soil OU. Treatment of the Area A Soil OU
soils will commence with the Stockpile Soils Area OU soils treatment. A final remedy for the
remaining portions of AAAP will be proposed following the completion of other RI/FS efforts
currently in progress. <•
Based on the CERCLA requirements and the detailed analysis of the alternatives, AAAP, in
consultation with EPA and ADEM, has determined that Alternative ID is the most appropriate
remedy for soils in Study Areas 12 and D within the Area A Soil OU.
The interim remedy for soils in Study Areas 12 and D within the Area A Soil OU for source
control includes:
Excavation of approximately 3,800 yd3 of lead-contaminated soils from Study
Area 12 and 5 yd3 of explosives-contaminated soils from Study Area D
Transportation of contaminated soils to Area B and storage along with the Stockpile
Soils Area OU soils in RMCSs
On-site treatment (in Area B) by incineration followed by solidification/stabilization
(if required) or solidification only (if applicable) of contaminated soils along with
the Stockpile Soils Area OU soils.
On-site disposal of treated soil at a designated area in Area B
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The cost of the selected remedy is presented next. The cost for excavating and incinerating the
Area A soils is presented in the following cost estimate. No costs are included for
mobilization/demobilization of the incinerator since remediation will take place at the same time
as the Stockpile Soils Area OU and these costs have already been accounted for in the Stockpile
Soils Area OU ROD. Also, since the selected alternative can be completed in a short time
period, no periodic O&M costs associated with the incinerator are expected to be realized.
Estimated Construction Cost $ 1,215,024
Estimated O&M Cost None
Estimated Total Present-Worth Cost, including
Engineering and Contingency $ 1,640,282
The remediation level for excavation of 246TNT-contaminated soil at Study Area D in Area A is
21 mg/kg. The remediation level for excavation of lead-contaminated soil at Study Area 12 in
Area A is 200 mg/kg.
Lead-contaminated materials which result in a TCLP extract in excess of 5 mg/L are considered
hazardous under RCRA. Explosives-contaminated material that is ignitable or reactive is
considered hazardous waste under RCRA.
Implementation of the selected interim action will result in the removal from Study Areas 12 and
D within Area A of all contaminated soils at concentrations above the remediation levels of
21 mg/kg for 246TNT and 200 mg/kg for lead, resulting from DOD operations. Implementation
of the selected remedy will also meet the following standards for treating the COCs in the
excavated soils from soils in Study Areas 12 and D within the Area A Soil OU:
Explosives-The ash generated from the incineration of explosives-contaminated soil
will be tested for destruction of explosives, as required by RCRA. A treatment
standard for 246TNT of 1 microgram per gram (jtg/g) will be used to demonstrate
destruction.
Lead—Concentration of less than 5 mg/L in the TCLP extract, as required by
RCRA.
Particulate Emissions-Routine analysis of stack gases will be performed to ensure
processes are operating efficiently and within acceptable air emissions standards for
the state of Alabama.
Confirmatory sampling along with remediation will be conducted to include broad
scan analyses, following the remediation to ensure that all contaminants of concern
resulting from DOD operations that would pose a risk to public health or the
environment have been addressed.
10.0 STATUTORY DETERMINATIONS
The selected alternative satisfies the requirements under Sec. 121 of CERCLA to:
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Protect human health and the environment
Comply with ARARs
Be cost effective
Use permanent solutions and alternative treatment technologies or resource recovery
technologies to the maximum extent practicable
Satisfy the preference for treatment as a principal element.
10.1 Protection of Human Health and the Environment
The selected alternative protects human health and the environment through excavation,
treatment, and disposal of contaminated soils from Study Areas 12 and D within the Area A Soil
OU.
During remediation activities, adequate protection will be provided to the community by reducing
the short-term risks posed by air emissions from the thermal treatment unit and reducing dust
potentially generated during material excavation and handling activities. In addition, workers will
be provided with personal protection equipment during all phases of remediation activities.
Long-term protection to human health and the environment will be provided by leaving no
residual risk from the DOD-related contaminants and reducing or eliminating the impact on the
environment.
Controls employed in the. alternative are adequate and reliable. This alternative has no
unacceptable short-term or long-term impacts on human health or the environment.
10.2 Compliance with ARARs
The selected alternative complies with all ARARs. All the COCs in soils of Study Areas 12 and
D within the Area A Soil OU (i.e., explosives and lead) are expected to meet required regulatory
treatment/disposal standards prior to disposal.
No federal or state chemical-specific ARARS prevent implementation of the selected alternative.
Soils will be remediated based on health-based cleanup levels determined to be protective to
human health and the environment. Lead-contaminated soils will be remediated to achieve the
health-based soil lead concentration of 200 mg/kg (based on blood-lead uptake levels in children).
Soils contaminated with 246TNT will be remediated to achieve the health-based soil 246TNT
concentration of 21 mg/kg (based on the resultant risk for adult residents and the contributing HI
due to exposure concentration for child residents).
No location-specific ARARS prevent the use of the selected alternative. All activities associated
with implementation of this alternative will be conducted away from sensitive environment (i.e.,
river or 100-year floodplain):
The following action-specific ARARS will be met with implementation of this alternative:
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Incinerator ash will be routinely tested for destruction of explosives, as required by
RCRA (40 CFR Part 264: Standards for Owners and Operators of Hazardous Waste
Treatment, Storage, and Disposal Facilities) and the state of Alabama (Alabama
Administrative Code Chapter 335-14-5.15(4)(a)l: Performance Standards for
Incinerators)
TCLP extract analysis on incinerator ash will be performed to ensure lead
concentrations in the treated soil are less than 5 mg/L prior to disposal, as required
by RCRA (40 CFR Part 264: Standards for Owners and Operators of Hazardous
Waste Treatment, Storage, and Disposal Facilities). Incinerator ash that does not
pass TCLP will be solidified/stabilized prior to disposal.
Incinerator ash and solidified/stabilized material (if required) will be disposed of on
site in Area B in accordance with RCRA (40 CFR Part 264: Standards for Owners
and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities) and
the State of Alabama (Code of Alabama, Title 22, Chapter 27: Alabama Solid
Waste Act and Alabama Administrative Code Chapters 13-1 through 13-7: Alabama
Solid Waste Management Regulations).
Routine analysis of stack gases will be performed to ensure incinerator processes
are operating efficiently and within acceptable air emissions standards, as required
by the CAA (40 CFR Part 50: National Primary and Secondary Ambient Air
Quality Standards and 40 CFR Part 61: National Emission Standards for Hazardous
Air Pollutants) and the State of Alabama (Code of Alabama, Title 22, Chapter 28:
Alabama Air Pollution Control Act of 1971 and Alabama Administrative Code
Chapters 335-3-1 through 335-3-14: Alabama Air Pollution Control Rules and
Regulations).
Workers will be provided with personal protection equipment during all phases of
the selected remedy, in compliance with the Occupational Safety and Health Act
(OSHA) (29 USC ss. 651-678). Adequate protection will be provided to the
community by reducing risks posed by air emissions from the thermal treatment
unit and reducing dust potentially generated during material excavation and handling
activities.
If the excavated soils are determined to be a hazardous waste, the following action-specific
ARARS would be applicable:
Wastes will be properly classified under guidelines for RCRA (40 CFR Part 261:
Identification and Listing of Hazardous Waste and 40 CFR Part 262: Standards
Applicable to Generators of Hazardous Waste) and the State of Alabama (Code of
Alabama, Title 22, Chapter 30: Alabama Hazardous Waste Management and
Minimization Act and ADEM Chapter 14-1: Alabama Hazardous Waste
Management Regulations).
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10.3 Cost Effectiveness
The selected remedy for soils in Study Areas 12 and D within the Area A Soil OU has been
determined to provide overall effectiveness proportionate to its costs. Although this alternative is
more expensive than Alternatives 1A and 1C, it takes advantage of the special equipment,
operators, site preparation, and treatment system mobilization already in place for treatment of
the Stockpile Soils Area OU. The estimated total present-worth cost for the selected alternative
is $1,640,000.
10.4 Use of Permanent Solutions and Alternative Treatment Technologies or Resource
Recovery Technologies to the Maximum Extent Practicable
The selected interim action is not designed or intended to be a final action for all soils within the
Area A operable unit but rather is intended to address only the soils within Study Areas 12 and D
of the operable unit. As such, the alternative meets the statutory requirements to use permanent
solutions and treatment technologies to the maximum extent practicable to achieve remediation
goals at only these two study areas. The criteria used in selecting the alternative include:
Short-term Effectiveness: The selected alternative does not involve off-facility
transportation of contaminated soils, thereby eliminating the risks to the community
due to spillage and dust emissions. The community, workers, and environment will
be protected during remedial actions by implementing appropriate protective
measures.
Long-Term Effectiveness and Permanence: The selected alternative provides for
remediation of contaminated soils from Study Areas 12 and D within the Area A
Soil OU. Direct exposure pathways would be eliminated until the soils can be
remediated with the Stockpile Soils Area OU. Upon treatment, the magnitude of
residual risks will be removed as all of the contaminants are treated and disposed of
in accordance with applicable regulations.
Reduction of Contaminant MTV: Contaminant mobility would be significantly
decreased due to the placement of the contaminants in lined storage buildings.
Contaminant toxicity and soil volume would be reduced upon treatment along with
the Stockpile Soils Area OU.
Implementability: All elements of the selected alternative are performed on site.
Required labor, equipment, and materials are available from various suppliers near
AAAP. Treatment of contaminated soil will not require any additional special
equipment or system mobilization since these components will already be in place
for the Stockpile Soils Area OU.
Cost: While the selected remedy is more expensive, it takes advantage of special
equipment and thermal treatment system mobilization costs which will be incurred
during treatment of the Stockpile Soils Area OU.
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10.5 Preference for Treatment as a Principal Element
The selected interim action utilizes treatment for the soils of Study Areas 12 and D within the
Area A Soils Operable Unit. Any additional required actions for these two Study Areas as well
as for all the soils of the operable unit will be addressed in the final Decision Document for the
Soils of the Area A Operable unit.
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES
The selected alternative (Alternative ID) is the preferred alternative presented in the Proposed
Plan. Subsequent discussion between AAAP, EPA, ADEM, USAGE, and AEC led to a decision
to limit the scope of actions to Study Areas 12 and D only. Additional investigations will
determine if additional actions are required in any other areas of the Area A soils operable unit.
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RESPONSIVENESS SUMMARY
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RESPONSIVENESS SUMMARY
1.0 OVERVIEW
The public reaction to the selected remedy is mainly acceptance. The majority of the comments
requested additional information on the types, volumes, and locations of contaminants; the safety
of workers and residents; and the timely implementation of the remedial action. All of the public
comments have been addressed, and the public appears to have no concern about implementation
of the selected remedy. Continued community relations activities will be held to maintain public
awareness of the status of remedial activities at AAAP.
2.0 BACKGROUND ON COMMUNITY INVOLVEMENT
General community interest in the AAAP site has historically not been great. Since the site was
declared excess to Army needs in 1973, more interest has come from private groups or industry
hoping to develop portions of the site. The southern part of the site (i.e., the former
nitrocellulose manufacturing area) was sold to the Kimberly Clark Corporation in the late 1970s,
and a paper products plant was constructed. In the mid-1980s, in response to interest in
purchasing the eastern part of AAAP (Area A), this section was remediated by the Army and the
contaminated soil was stockpiled in the western part of AAAP (Area B), creating the Stockpile
Soils Area OU. A ROD for treatment [i.e., incineration followed by solidification/stabilization
(if required)] of the Stockpile Soils Area OU soils has been signed.
Post-excavation sampling was performed to verify the remediation efforts within Area A, and two
sites (Study Areas 12 and D) were subsequently identified as containing contamination above
acceptable levels. A supplemental RI/FS was performed to determine the extent of the additional
contamination and to select a remedial action. Studies to find the existence and extents of
contamination in Area A have been published in the local libraries.
Notice of the public comment period and meeting for the Area A Soil OU was placed in four
local newspapers on March 30, 1993, and the public comment period extended from April 1
through April 30, 1993. No written public comments were received. The public meeting was
held on April 20, 1993, at the Central Alabama Community College, located about 5 miles from
the AAAP site. The questions asked were mainly to obtain more detailed information on the
identified contamination and the proposed remedy.
3.0 SUMMARY OF PUBLIC COMMENT AND AGENCY RESPONSE
At the public meeting held on April 20, 1993, the public was given the opportunity to comment
and ask questions about the Proposed Plan. The following is a summary of the
questions/comments raised by the public and Army/regulators' responses given at the meeting,
and supplemental answers, where applicable:
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Ql. How big of an area is Area 12?
Answer at the meeting: (USAEC) Probably no more than about several acres. It is not
a very big area. It is big in comparison to some of the others, but about several acres.
Answer at the meeting; (AAAP) If you note this area right here is Area A in its entirety
and consists of about 2,700 acres. This area right here is Area 12. This looks like
maybe 30 or 40 acres.
Q2. What are the contaminants?
Answer at the meeting: (USAEC) At Area 12, the contaminant is lead and we did find
some small amounts of explosive in that soil, but, again, the lead is causing us to
remediate.
Q3. This is the old burning ground?
Answer at the meeting: (USAEC) Yes.
Q4. What about the chromium content?
Answer at the meeting: (USAEC) We did not find any chromium there that was
basically in excess of natural conditions.
Q5. I am under the impression that you found lead, B2EHP, chromium, 13DNB, 24DNT,
26DNT, iron, lead, in trace amounts or what?
Answer at the meeting: (USAEC) Very low amounts, yes. The only one of those that
was at a level of concern was the lead. All of the others were found in very trace levels.
Q6. Does the cost of Alternative D include the remediation of the soil after it is removed?
Answer at the meeting: (USAEC) Yes, it does, that is included in the estimate, and we
consider that a conservative estimate also. It conceivably could be less than that.
Answer at the meeting: (AAAP) The whole estimate there is based on a conservative
figure. In other words, the feeling is it would probably be a lesser amount of material
and a lesser cost.
Q7. Under 29 CFR 1910.120 would this be a 40 hour HAZMAT trained employee?
Answer at the meeting: (USAEC) Yes.
Q8. Will Weston Services be doing this remediation or would a local contractor be doing it?
/•
Answer at the meeting: (USAEC) Certainly, the incineration will be done under the
contract with Weston Services. It is envisioned that probably the removal of the soil
would be a modification to the contract, but certainly, it would be open to suggestions.
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Our intent is to modify the contract, but that has not occurred yet, obviously because
there has been no decision on this remediation.
Q9. Under 1910.120, would this be a Level D, C, B, A, whatever?
Answer at the meeting: (ESE) I think that would have to be determined when they
develop the safety plan.
Answer at the meeting: (USAEC) Yes, I think that has got to be determined at that
time.
Q10. A site safety plan has not been developed, you are just talking about the feasibility study
now?
Answer at the meeting: (USAEC) Right, we are proposing this. Once it is approved,
once the Record of Decision is signed that is basically saying, 'Yes, we have decided and
everybody has concurred that we will do this remediation, the action that we have
described.' At that point then we would make site safety plans and all and look at and
determine the appropriate level of protection.
Qll. What is the basis for the 200 part per million cleanup standard for lead in the soil?
Answer at the meeting: (ESE) That is a risk-based number based on risk assessment. I
can verify that, but I believe that was based on risk assessment.
Answer at the meeting: (USAEC) That is considered a risk base level, that at 200 parts
per million of lead, there is a risk that would be involved in being exposed to that
amount.
Q12. It is not based on an RCRA corrective action level for lead?
Answer at the meeting: (ESE) No, it would be risk-based.
Answer at the meeting: (USAEC) Yes, risk.
Answer at the meeting: (ADEM) For an individual complex, EPA guidance usually has
a cleanup level of 500 to 1,000 parts. This is definitely a risk.
Q13. Do you know what the RCRA corrective action level in soils for lead is?
Answer at the meeting: (USAEC) I do not remember.
Supplemental Answer: (ESE) There is no RCRA corrective action level in soils for
lead.
Q14. To what depth is this 3,800 cubic yards? Is it six to eight inches over the entire surface?
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Answer at the meeting: (USAEC) It is about 3 ft. We are estimating basically 3 ft
deep. That is why I am saying we are conservative, because it may not go down 3 ft in
all places, but we think it is no deeper than that.
Q15. I was wondering, you were talking about there were explosives and things in Area 12?
Answer at the meeting: (USAEC) Yes, very small amounts. The gentleman, when he
listed those compounds, some of those are explosives and they were found in very small
amounts, though.
Q16. I was wondering in transporting that to the storage area, it would have to be first
excavated, dug up and loaded. What are the dangers involved that something might
happen that they might explode or anything like that?
Answer at the meeting: (USAEC) Really, none. This soil is not reactive, reactive
meaning that it could be detonated or burned. And this soil will not detonate and it will
not burn, so there is no risk in that regard.
Q17. You said five cubic yards, right?
Answer at the meeting: (USAEC) Of the explosive soil, yes. That is the soil from Area
D. We are talking about two pieces of soil. The soil from Area 12 is about 3,800 cubic
yards. The soil from Area D, which is just south of Area 12, is only about 5 cubic yards
and that is the soil that we found explosives in the soil above criteria.
Again, even though they are above criteria, they are still not considered reactive. They
will not detonate and will not burn.
Q18. I live on the property and I represent the owner of the site they are talking about. I ran a
disk harrow over it Wednesday and I am still here. I am not dead. We did not know
exactly where the site was until now. And so, it is not --1 did not blow up or anything.
It cannot be too bad.
But our position is when we bought the property, we were under the impression that, and
by contract, that the site was clean, and we just want to enforce that it gets cleaned up,
because especially from a personal standpoint, me living on the property, I do not want
any risk. I am probably the only person who lives on the property of the whole ammo
plant. And being there all the time, I have not been sick or anything else. But on the
company standpoint, we bought something clean and we want it clean and the
government is very good about working out and we have had no problems so far.
I want to assure you we have worked with the government and they have worked with us
and there is no problems with everything being expedient. You know, we have the most
concern of everybody because we are on the property every day and we have had no
problem from the government. Like I say, they have helped us.
Answer at the meeting: An answer to this statement was not necessary.
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Q19. When did you find this additional soil in Area 12 and D?
Answer at the meeting: (USAEC) It was found from studies done during the summer of
1991.
Q20. Up until that time you had assumed that all of the land that they had bought had been
remediated?
Answer at the meeting: (USAEC) Right, we had remediated and we felt that based on
what we had done that we had cleaned the property. And then we were asked to do
some additional investigation and we found these two pieces. As we agreed and said we
would do-if we found anything additional, we are removing it. I would like to say that
this removal action and incineration will be a final action regarding the soil at Area A.
Supplemental answer: If additional actions are required following the proposed interim
action, these actions will be presented in the final ROD.
Q21. You said you did representative sampling? But you said you did not know whether it
went below three feet or not. Did you not drill below three feet in the boring? .
Answer at the meeting: (USAEC) Yes, we did representative sampling, but you do not
go down three feet on every inch of the property. So what we are saying is we found it
no deeper than three feet, but it could be three feet here and it could be a lot less over
here. When we are estimating volume, we are taking basically a cylinder or a volumetric
shape out and saying that all of that is contaminated soil. All I am saying is when we do
verification sampling, which will be basically sampling the soil as it is removed, we will
remove all that has to be removed until it is below criteria.
Q22. Have you done any groundwater sampling? Did you find anything in that?
Answer at the meeting: (USAEC) Yes, we have done groundwater sampling. We have
found nothing in Area A above criteria or at any levels requiring any response action,
and we are going to be doing some additional sampling and investigation of the
groundwater at Area A to confirm that, to ensure the owners that this property is indeed
clean.
4.0 REMAINING CONCERNS
All of the public comments have been adequately addressed. The public appears to have no
concerns about the implementation of the selected remedy.
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COMMUNITY RELATIONS ACTIVITIES
AT AAAP
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COMMUNITY RELATIONS ACTIVITIES
AT AAAP
This section is incomplete until the Public Comment Period and Public Hearing have been
completed and all questions addressed. Once the Public Comment Period is concluded, this
section will be incorporated into the document.
To date, communication with community members regarding past and ongoing environmental
studies at AAAP has consisted of the following:
1. A public meeting was held in April 1985 to announce plans to conduct an RI/FS
study at AAAP.
2. A public meeting was held in September 1986 in Childersburg, AL to brief the
public on a (a) the findings of the completed RI, (b) the initiation of the Area A
decontamination and/or cleanup effort, and (c) the status of the ongoing FS.
3. Mr. Ronnie Wynn, AAAP caretaker, spoke to the Sylacauga Rotary Club in July
1990 on the status of AAAP. Mr Wynn has also offered site tours to interested
citizens in the AAAP community.
4. Community interviews were conducted with community leaders and residents
adjacent to AAAP (July 23 through 26, 1990).
5. A public meeting was held at Central Alabama Community College in August 1991
to discuss the results of the site-wide RI.
6. A public comment period on the Proposed Plan for the Stockpile.Soils Area
Operable Unit was held from November 21, 1991 to December 23, 1991.
7. A public meeting was held at Central Alabama Community College on December 5,
1991 to discuss the Proposed Plan for the Stockpile Soils Area Operable Unit.
8. A public comment period on the Proposed Plan for the Area A Soil Operable Unit
was held from April 1, 1993, to April 30, 1993.
9. A public meeting was held at Central Alabama Community College on April 20,
1993, to discuss the Proposed Plan for the Area A Soil Operable Unit.
Other communication techniques the Army has used to provide the public and media with updated
information on AAAP include producing fact sheets, mailing out news releases and letters of
invitation, providing site tours, and storing AAAP documents in repositories for public review.
411/1081594 54
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REFERENCES
Dragun, J. and Chiasson, A. 1991. Elements in North American Soils. Hazardous
Materials Control Institute. Greenbelt, MD.
Environmental Science & Engineering, Inc. (ESE). 1992a. Risk Assessment of
Area A, AAAP. Prepared for U.S. Army Toxic and Hazardous Materials
Agency. Gainesville, FL.
Environmental Science & Engineering, Inc. (ESE). 1992b. Remedial Investigation
of Area A, AAAP. Prepared for U.S. Army Toxic and Hazardous Materials
Agency. Gainesville, FL.
Shacklette, H.T. and Boerngen, J.G. 1984. Element Concentrations in Soils and
Other Surficial Materials of the Conterminous United States. U.S. Geological
Survey Professional Paper 1270. Washington DC, U.S. Government Printing
Office.
411/1033094
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