PB94- 964073
EPA/ROD/R04-94/206
February 1995
EPA Superfund
Record of Decision:
Robins Air Force Base
(O.U. 2), Houston County, GA
3/29/1994
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FINM
U.S. AIR FORCE INSTALLATION
RESTORATION PROGRAM
SUPERFUND
INTERIM RECORD OF DECISION
ROBINS AFB ZONE 1, GEORGIA
OPERABLE UNIT 2
IMPACT ON WETLANDS
FEBRUARY 22, 1994
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CONTENTS
SECTION
DECLARA TION FOR THE INTERIM ACTION RECORD OF DECISION
DECISION SUMMARY
1.0 Site Name and Location
2.0 Site History and Enforcement Activities
3.0 Highlights of Community Participation
4.0 Scope and Role of Operable Unit
5.0 Site Characteristics
6.0 Summary of Site Risks
7.0 Description of Alternatives
8.0 Summary of Comparative Analysis of Alternatives
9.0 Selected Remedy
10.0 Statutory Determinations
.
RESPONSIVENESS SUMMARY
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DECLARATION FOR THE
INTERIM ACTION
RECORD OF DECISION
11
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DECLARA nON FOR THE INTERIM ACTION
RECORD OF DECISION
SITE NAME AND ADDRESS
Zone I Robins Air Force Base
Operable Unit 2, Impact on Wetlands
Warner Robins, Houston County, Georgia
ST A TEMENT OF PURPOSE
This Decision Document presents the interim selected remedial action for Operable Unit 2 of
the Zone I Robins Air Force Base (AFB) Site, Houston County, Georgia chosen in
accordance with the Comprehensive Environmental Response, Compensation, and Liability
Act (CERCLA) as amended by the Superfund Amendments and Reauthorization Act (SARA),
and to the extent practicable, the National Oil and Hazardous Substances Pollution
,Contingency Plan (NCP). This decision is based on the Administrative Record for this site,
which is on the file in the Directorate of Environmental Management office, Robins AFB,
Georgia 31q98.
This interim remedial action is taken to protect human health and the environment from the
threat, while final remedial solutions are being developed. The State of Georgia and Region
IV, USEPA concur with the selected interim remedy.
ASSESSl\1ENT OF THE SITE
The wetlands associated with Zone I, OU2 provide an important habitat for a variety of
wetlands plant and animal species, and protection of the wetlands should be given a relatively
11l
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-
high priority. Actual or threatened r~leases of hazardous substances from this site, if not
addressed by implementing the response action selected in this Interim Action Record of
Decision (ROD), may present an immi~ent and substantial endangerment to public health,
welfare or the environment.
. DESCRIPTION OF THE SELECTED REMEDY
The Zone I Robins AFB site is divided into three operable units. Operable Unit I (OUI)
addresses Landfill No.4 and the Sludge Lagoon and comprises source control. Operable
Unit 2 (OU2) is a phase to determine the degree of impact that has occurred in the
downgradient wetlands area (east and southeast of Landfill No.4). Operable Unit 3 (OU3)
addresses the groundwater beneath and adjacent to Landfill No.4 and the Sludge Lagoon.
The scope of this ROD is limited to OU2.
The selected interim remedy for OU2, limited action, includes the following:
.
Institutional controls (Le., fence construction to restrict access, posting signs)
for future site access and water use restrictions
.
Comprehensive monitoring for a minimum of one year not to exceed three
years in support of physical/chemical and ecological/biological monitoring
plans to be developed to monitor stabilization of the site following redirection
of runoff discharge around the landfill and diversion of industrial wastewater
. discharge from upgradient of the landf1l1 and wetlands, so that a final remedial
action can be developed from the current and expected future conditions.
.
Development of a contingency plan that describes containment measures to be
implemented in the event that predetermined "trigger values" are exceeded.
Both the physical and chemical characteristics of the wetlands may have been altered since
the collection of data used to determine the need for remediation. The possible changes were
caused by two events. One event was the redirection of runoff from a 400-acre watershed
from through the landfill to around the landfill.
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The second event was the completion of a p'ipeline that now routes approximately 2 million
gallons a day of domestic and industrial wastewater directly to the Ocmulgee River. This
discharge used to be into and through the wetlands to the Ocmulgee River. One purpose of'
the monitoring program is to evaluate the expected changes so that the final action can be
developed to address the current/future conditions.
STATUTORY DETERI\flNATION
,"'."
This interim action is protective of human health and the environment, waives Federal and
State Applicable or Relevant and Appropriate Requirements for this limited scope action, and
is cost-effective. This action is interim and is not intended to provide permanent solutions
and alternative treatment or recovery technologies, to the maximum extent practicable for
OU2. Because the action will not constitute the final remedy for OU2, the statutory
preference for remedies that employ treatment that reduces toxicity, mobility, or volume as a
principal element will be addressed by the final response action. Subsequent actions are
planned to address fully the threats posed by the conditions at OU2. Because this remedy
will result in hazardous substances remaining on site above health-based levels, a review will
be conducted to ensure that the remedy continues to provide adequate protection of human
, health and the environment within five years after commencement of the remedial action.
Because this is an interim action ROD, review of this site and this remedy will be ongoing as
the Air Force continues to develop remedial alternatives for OU2.
:t L
/" . ;
r-; ,- I A.),/rz
~ ALAN P. BABBITI'
Acting Deputy Assistant Secretary of the Air Force
(Environmental, Safety and Occupational Health)
~/;(lfV'
Date
Assistant Administrator/Regional Administrator
U.S. Environmental Protection Agency, Region 4
Date
v
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DECISION SUMMARY
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1.0 SITE NAME, LOCA nON AND DESCRIYfION
Robins AFB is an active facility occupying 8,855 acres about 18 miles south of Macon,
Georgia (Figure 1). Robins AFB is bounded on the immediate west by the City of Warner
Robins, on the north by a housing subdivision in Houston County, on the south by
unincorporated Bonaire, and on the east by the Ocmulgee River and its floodplain.
The Zone I, Robins AFB, National Priority List (NPL) site is located in the central portion
of the base. Zone 1 consists of Landfill No.4, which covers 45 acres, and an adjacent 1.5
acre sludge lagoon (Figure 2). The study area associated with OU2 is located east and
southeast of Landfill NO.4 (Figure 2).
Zone 1 is located adjacent to a bluff that forms the western boundary of the Ocmulgee River
floodplain. The floodplain extends about I to 2 miles eastward to the river. Landfill No.4
was originally constructed by disposing of fill material into the floodplain and wetland area
from the bluff and advancing to the east. The sludge lagoon was constructed on the northern
boundary of Landfill No.4 by excavating and building earthen dikes. Surface water at
'Robins AFB generally drains from west to east into the Ocmulgee River floodplain.
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VICINITY MAP
RI/FS ZONE 1, OPERABLE UNIT 2
CDM FEDERAL PROGRAMS CORPORATION ROBINS AFB, GEORGIA
FIGURE No, 1
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OPERABLE UNIT 2
STUDY AREA
Figure 2- ZONE 1, OPERABLE UNIT 2 STUDY AREA
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2.0 SITE HISTORY AND .ENFORCEMENT ACTIVITIES
Robins AFB currently serves as a worldwide logistics management center for aircraft,
missiles and suppon systems. and is a major repair center for aircraft and airborne electronic
systems.
Robins AFB has generated various types of solid wastes over the years, including refuse and
hazardous wastes. The hazardous wastes include electroplating wastes containing heavy
metals and cyanide, organic solvents from cleaning operations and fire training exercises, and
off-specification chemicals such as pesticides.
In 1982, Robins AFB conducted a base-wide survey to identify and assess past hazardous
waste disposal practices. Disposal areas were groupeo into eight zones based primarily on
location and type of disposal activity. Zone 1 (Landfill No.4 and the Sludge Lagoon) was ,
considered to have the highest potential for migration of hazardous substances and as a result
was placed on the CERCLA NPL by the U.S. Environmental Protection Agency (EPA) in
1987. Landfill No.4 reportedly operated from 1965 until 1978 for disposal of general refuse
and industrial wastes. The Sludge Lagoon was used for disposal of industrial wastewater
treatment plant sludges and other liquid wastes from 1962 to 1978. The Landfill and the
Sludge Lagoon were both closed and covered with clean fill in 1978.
In June of 1989, Robins AFB entered into a Federal Facilities Agreement with the Georgia
Department of Environmental Protection (GEPD) and the EP A to establish a procedural
framework and schedule for developing, implementing, and monitoring appropriate response
. .
actions at the site in accordance with CERCLA, the NCP, Superfund guidance and policy,
and the Georgia Hazardous Waste Management Act (GHWMA).
The initial remedial investigation/feasibility study (RI/FS) for Zone 1 was completed in 1990.
The initial RI focused primarily on the sludge lagoon and Landfill No.4, and identified both
organic and inorganic contamination in groundwater, surface water, sediment,. and soil. The
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initial FS focused primarily on Zone 1 under au 1. The remedial action goals developed for
protection of human health and described in the FS study and ROD under OU 1 focusl", on
source control.
A supplemental RI was performed and completed in 1992 to further assess the eco:' ..:al
risks associated with the site as it relates to the study area associated with OU2.
The following reports describe the results of investigations at Zone 1, OU2 to date:
. HAZWRAP, U.S. Air Force Installation Restoration Program, Supplemental
Remedial Investigation, Zone 1, Operable Unit 2. Robins AFB, November 1992.
. HAZWRAP, U.S. Air Force Installation Restoration Program, Feasibility Study,
Zone 1, Operable Unit 2. Robins AFB, July 1993.
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3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
The RI for the Robins AFB Zone 1 OU2 impact on wetlands was released to the public in
November 1992, and the FS in July 1993. The Proposed Plan was released on August 16,
1993 for public comment. These documents were made available to the public in the
Administrative Record located at the Directorate of Environmental Management, Robins AFB
and at the Environmental Information Repository at the Nola Brantley Memorial Library in
Warner Robins. The notice of availability of these documents was published in the Macon
Telegraph and the Daily Sun. A public comment period was held from August 16, 1993.
through September 29, 1993. A public meeting for OU2 was held on September 16, 1993.
At this meeting, representatives of Robins AFB, EPA, and the GEPD answered questions
about the site and the remedial alternatives under consideration. A transcript of the public
meeting can be reviewed at the information repository.
The Proposed Plan identified the preferred interim remedy for the area associated with aU2
Alternative 2, from the FS (see Section 4); use of institutional controls for future site access
and water use restrictions, and a Comprehensive Monitoring Program that will be used to
determine the stability of the site. Robins AFB, EPA, and GEPD reviewed all written and
verbal comments submitted during the public comment period. Upon review of these
comments, it was determined that significant changes to the Proposed Plan preferred interim
remedy were not necessary.
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4.0 SCOPE A)\I.l) ROLE. OF OPERABLE UNIT 2
The overall strategy of Zone I is divided into three operable units. The interim remedial
action selected in this ROD is appiicable to OU2.
OU2 is directed at determining the degree of impact that may have occurred in the wetlands
area and surface waters from the known source of contamination in au 1 and remediation of
the impacts identified. OUI addresses Landfill No.4 and the Sludge Lagoon, and comprises
source control. OU3 is directed at determining the degree of impact that may have occurred
in the groundwater beneath and adjacent to Landfill No.4 and the Sludge Lagoon, and
remediation of impacts identified.
The overall goals of the selected interim remedy for the area associated with OU2 are:
. Protect existing habitat
. Minimize the potential direct exposure of the public and base personnel to hazardous
substances
. Monitor water balance stabilization of the site following redirection of runoff
discharge and diversion of industrial wastewater discharge.
These goals would be achieved by the use of institutional controls for future site access and
water use restrictions. In addition, the comprehensive monitoring program will be used to
evaluate changes to the site caused by the completion of a runoff diversion system which
redirects runoff from a 400-acre watershed from through the landfill to around the landfill
and. the completion of a pipeline that routes 2 million gallons a day of industrial waste into
the Ocmulgee River that had formerly been discharged through the wetlands. This
information can be used to develop a final action for the site which addresses current and
future conditions.
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5.0 SUMMARY OF SITE CHARACTERISTICS
5.1 SUMMARY OF ZONE 1 HYDROLOGY
The local topography, soils, and climate determine how water moves through the site. Zone
I of the Robins AFB is located on the western edge of the floodplain of the Ocmulgee River
(Figure 2). The floodplain in Zone I is a low flat region covered by wetlands and standing
water. The surface and groundwater flow across Zone 1 is generally to the east toward
Horse Creek, a south-flowing tributary of the Ocmulgee River, and to the Ocmulgee River.
The Zone 1 wetland soils consist of approximately 6 ft of saturated organic matter and peat,
underlain by a layer of clay ranging in thickness up to approximately 10 ft. The clay layer is
underlain by an interbedded sand and gravel deposit that constitute the alluvial aqu.ifer unit
under most of Zone 1. The clay layer is thought to restrict water flow between the wetlands
and the alluvial aquifer, and to cause the alluvial aquifer to exist under semi-ronfined
conditions. Landfill No. 4 and sludge lagoon were placed on the western edge of the
floodplain wetland deposits. Fill materials associated with the landfill are partially saturated
and comprise the surficial fill aquifer unit.
The western edge of the Ocmulgee River floodplain is defined by a reiatively steep 30 to 40
ft increase in elevation along the southern, western, and northern boundaries of Zone 1. The
upland areas adjacent to the Ocmulgee River floodplain consist of sand, gravel, and clay
layers of the Providence Formation. Portions of these upland areas adjacent to Zone 1 are
within the topographic basin that drains into the Zone 1 wetlands. The Zone 1 wetlands are,
therefore, the hydrologic sink or receptor area for the topographically higher portions of its
drainage basin.
The Robins AFB is located in a humid, temperate region characterized by high rainfall.
Average annual precipitation at the base is 44.9 in., with an estimated evapotranspiration rate
of approximately 38.4 in. per year. The difference between precipitation and evapotran-
8
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spiration, apPfoximately 6.5 in. per year, results in" a large quantity of water available for
recharge to the groundwater and surface water systems. Urbanization and development
associated with base activities in the uplands portion of the Zone 1 drainage basin have
resulted in a predominance of paved areas. The decrease in vegetation in the developed
areas reduces evapotranspiration losses while the impervious surfaces prevent infiltration and
redarge of the groundwater system. The result is that in the developed portions of the Zone
I drainage basin, most of the precipitation that falls will flow via surface water runoff into
and through the Zone I wetlands.
Most of the surface water runoff that leaves the upland areas of the Zone 1 drainage basin is
concentrated into several storm sewers, which discharge at numerous locations near the
eastern edge. The remainder of the surface water entering Zone 1 flows directly into Horse
Creek from north of Zone 1, east of the Base runways.
Hannah Road and Lights Service Road traverse portions of Zone 1 (Figure 2) and influence
surface water flow in the area. The roads are built on embankments of imported soil that
restrict the flow of surface water across Zone 1. Surface water located in the floodplain
portion of Zone I west of Hannah Road leaves the area primarily through two pipe structures
,
under Hannah Road. Surface water present in the wetlands west of the overflow control
structures tend to flow toward the structures. Rates of flow near the entrance of these
structures would therefore be expected to be higher than would surface water flow rates
further away from these control structures.
Groundwater is present in Zone 1 in several aquifer units. Although flow rates through these
aquifers is low compared to surface water flow, the aquifer units exhibit relatively high
contaminant concentrations and may therefore contain a majority of the contaminant mass
that is present in Zone 1. The important aquifers include the surficial fill, alluvial gravel,
and the Providence Formation. Beneath the Providence Formation aquifer is the Cusseta
Clay Formation and Bluff town Aquifer.
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The surficial fill aquifer exists in Landfill No.4, the sludge lagoon, and in isolated areas
associated with the Hannah and Lights Service road embankments, where artificial fill has
been placed into the wetlands peat and clay deposits. A schematic cross-sectional view of
Zone I showing assumed groundwater flow directions and interactions is shown on Figure 3.
The alluvial gravel aquifer is present under the peat and clay deposits throughout the
floodplain area in Zone 1 except for the west portion of the landfill. Groundwater flow is
consistently to the east. Water levels in wells penetrating this aquifer rise above the top of
the aquifer surface, indicating that the aquifer is under semi-confined conditions. The
alluvial gravel deposits, like the clay and peat layers above it, decrease in thickness toward
the west and disappear along the western edge of the Ocmulgee River floodplain in Zone 1.
Cross sections compiled from existing borehole data suggest that the peat, clay, and alluvial
gravel deposits all disappear somewhere beneath the western portion of Landfill No.4.
Beneath the alluvial gravel aquifer is the Providence Formation. This geologic unit extends
across the entire site and comprises the upland surface immediately west of Zone 1. Lateral
groundwater flow in this aquifer is also toward the east. Based on limited data, the vertical
component of flow between the alluvial gravel and Providence FormatioD aquifers within
Zone I appears to be generally upward toward the alluvial gravel aq~ifer throughout Zone 1.
The.landfill solids and surficial fill aquifer may be in direct hydraulic communication with
the Providence aquifer in the western portion of the landf1ll, where the intervening peat,
clay, and alluvial gravel deposits are. thin or absent. The alluvial aquifer is not present 'west
of the landfill where vertical gradients in the providence are downward.
5.2 AQUATIC BIOWGY
Macroinvertebrate sampling conducted during the Zone 1, OU2 RI field investigation
demonstrated that stations located downgradient generally exhibit greater species diversity
and larger populations than upgradient stations. The results of a Rapid Bioassessment
10
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Protocol III analysis conducted for the OU2 RI showed some locations in both upgradient and
downgradient areas demonstrate nonimpairment while others are severely impaired.
5.3 WETLAND ECOLOGY
Vegetation surveys conducted during the Zone I, OU2 RI field investigation indicated
numerous vegetative zones and habitats and a diverse flora associated with open water,
emergent wetlands, and mature bottomland hardwood forest. Potentially occurring
threatened and endangered species in the OU2 study area include dwarf witch-alder, fly-
catchers, hooded pitcher-plant, sweet pitcher-plant, and Florida willow.
5.4
Wll..DLIFE BIOLOGY
A breeding bird survey conducted during the Zone 1, OU2 RI field investigation showed no I
significant differences or trends in the types of species observed in the study and reference
areas. The survey showed that there are numerous species present that are indicative of
healthy bottomland forest ecosystems. Results are summarized on Table 1. Potentially
occurring threatened and endangered species in the OU2 study area include American
alligator, Bald eagle, Florida panther, and Wood stork.
5.5
EV ALUA TION OF CONTAMINANT SOURCES
The OU2 field investigations were designed to collect information necessary to assess the
relationship between compounds detected in the wetlands and compounds present in the
Landfill No.4 and sludge lagoon. The site conceptual flow model indicates that most of the
flow through Zone 1 is surface water, and that a majority of the surface water inflow to
Zone 1 originates from sources hydrologically upgradient of the Zone 1 study area
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TABLE 1
SUMMARY OF BREEDING BIRD SPECIES OBSERVED
RI/FS ZONE 1, OU2
Robins AFB, Georgia
Cattle Egret Bubulcus ibis
Great Egret Casmerodius albus
Great Blue Heron Ardea herodias
Mallard Anas plaryrhynchos
Killdeer Charadrius vociferus
Lesser Yellowlegs Tringa jlavipes
Solitary Sandpiper Tringa soLiraria
Sanderling CaLidris alba
Turkey Vulture Carhanes aura
Northern Bobwhite Circus virginianus
Rock Dove Columba Livia
Mourning Dove Zenaida macroura
Yellow-billed Cuckoo Coccyzus american us
Barred Owl Srrix varia
Common Nighthawk Chordei/es minor
Chimney Swift Cohaelura pelagica
Ruby Throated Hummingbird Archilochus alexandri
Belted Kingfisher Ceryle alcyon
Red-bellied Woodpecker Melanerpes caroLinus
Common Flicker CoJaples aura/US
Downy Woodpecker Picoides pubescens
Hairy Woodpecker Picoides villosus
Pileated Woodpecker Dryocopus pi/ealus
Eastern Kingbird Tyrannus ryrannus
Great-crested Flycatcher Myiarchus crinirus
13
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TABLE 1 (Cont.)
SUMMARY OF BR,EEDING BIRD SPECIES OBSERVED
RI/FS ZONE 1, OU2
Robins AFB, Georgia
Eastern Wood Peewee Conrous virens
Eastern Phoebe Sayomis phoebe
Acadian Flycatcher Empidonax vireseens
Tree Swallow Taehycineta bieolor
Nonhern Rough-winged Swallow. Steigidopteryx serripennis
Barn Swallow Hirundo rustiea
Blue Jay Cyanocitta eristata
American (Common) Crow Corvus braehyrhynehos .
Fish Crow Corvus ossifragus
Tufted Titmouse Parus bieolor I
Carolina Chickadee Parus earolinensis
White-breasted Nuthatch Sitta carolinensis
Carolina Wren Thryothorus ludovicianus
Blue-gray Gnatcatcher Polioptila eaerulea
Eastern Bluebird Sialia sialis
Wood Thrush Hylociehia mustelina
American Robin Turdus migralorius
Loggerhead Shrike Lanius ludovicianus
Gray Catbird Dumetella carolinensis
Nonhern Mockingbird Mimus polyglonos
Brown Thrasher Toxostoma rufum
European Starling Stumus vulgaris
White-eyed Vireo Vireo griseus
Yellow-throated Vireo Vi reo flavifrons
Red-eyed Vireo Vireo olivaceus
14
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TABLE i (Cant.)
SUMMARY OF BREEDING BIRD SPECIES OBSERVED
RIfFS ZONE 1, OU2
Robins AFB, Georgia
Prothonotary Warbler PrOlhontaria cirrea
Northern Parula Parula americana
Black and White Warbler Mniotilta varia
Cerulean Warbler Dendroica cerulea
Magnolia Warbler Dendroica magnolia
Yellow-rumped Warbler Dendroica coronara
Yellow-throated Warbler Dendroica dominica
Prairie Warbler Dendroica discolor
Pine Warbler Dendroica palmarum
Yellow Warbler Pendroica petechia
Kentucky Warbler Oporomis formosus
Hooded Warbler Wilsonia cirrina
Worm-eating Warbler Helmirheros vermivorus
Swainson's Warbler Limnothlypis swainsonii
Ovenbird Seiurus aurocapillus
Louisiana Waterthrush Seiurus mOlacilla
Common Yellowthroat GeOlhlypis trichas
Yellow-breasted Chat Octeroa virens
Nonhern Cardinal Cardinalis cardinalis
Indigo Bunting Passerina cyanea
Rufous-sided Towhee Pipilo erythrophthalmus
Eastern Meadowlark Stumella magna
Red-winged Blackbird Age/aius phoeniceus
Brown-headed Cowbird MolOlhrus arer
Common Grackle Quiscalus quiscula
15
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TABLE I (Cant.)
SUMMARY OF BREEDING BIRD SPECIES OBSERVED
RIfFS ZONE. I, OU2
Robins AFB, Georgia
Scarlet Tanager Piranga olivacea
Summer Tanager Piranga rubra
Double-crested Cormorant Phalacrocorax aurirus
Anhinga Anhinga anhinga
Wood duck Aix sponsa
Red-tailed Hawk Bureo jamaicensis
Green Heron Burorides stria/us
Yellow-bellied Sapsucker Sphyrapicus varius .
Song Sparrow Melospiza melodia
White Ibis Eudocimus albus &
Little Blue Heron Egretta Caerulea
American Red start Selophaga ruticilla
Rose-breasted Grosbeak Pheuclicus ludovicianus
Nonhern Harrier Circus cyaneus
Red-shouldered Hawk Bureo linea/us
Broad-winged Hawk Bureo plaryplerus
- -
.
16
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boundaries. The following surface water, aquatic sediment, or wetland soil samples sites
were determined to be located hydraulically upgradient of the landfill and sludge lagoon or
not effected by Zone I contaminants.
CDM Sample Sites:
CH2M HILL Sites:
SI, S2, S3, S9, SIO, S14, SR
BCG-SED-Ol, -02, -03 .
BCG-SW-Ol, -02, -03, LF27
At most :;ample sites, more than one type of sample (e.g., surface water, sediment, wetland
soil, biota samples) were collected. Refer to Figures 4 and 5 for sample site locations.
Figure 6 illustrates the CH2M Hill background samples. The site conceptual model also
suggests that the surficial fill aquifer, located beneath the landfill and sludge lagoon,
disch~ges water laterally into the wetlands surface water or peat deposits east and northeast
of the landfill, and also vertically into the underlying alluvial gravel and Providence
Formation aquifers along the western margins of the floodplain. Groundwater in the alluvial
gravel and Providence Formation aquifers is likely to be isolated from the overlying wetlands
east of the landfill due to the presence of an extensive clay layer.
~ummaries of detected compounds for all samples were used to evaluate potential source
areas. Listings of both the number of detections and the maximum detected concentrations
were compiled separately for upgradient and downgradient sample populations for the
groundwater, surface water, and sediment results. Wetland soil sample results were included
with sediment results for this evaluation. The individual lists were then combined into two
tables based on media type. Table 2 lists the summary results for all liquid media samples,
including landfill and sludge lagoon leachate, groundwater, and surface water. Table 3 lists
the summary results for all solids media samples, including sludge lagoon and landfill sludge
samples, landfill surface soil (listed as Landfill soils), and sediment/soil. Compounds
detected in any of the listed sample media were included on both Tables 2 and 3, to aid in
the evaluation of potential source areas.
17
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19
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SAMPLING LOCATIONS
ROBINS AFB, GEORGIA
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Figure
6
-------
TABLE 2
DETECTIONS OF ANAL YTES IN LIQUID MEDIA
COMPOUNDS DETECTED IN SOURCE AREA LEACHA TE* GROUNDWATER. SURFACE WATER
A T LEAST ONE MEDIUM
ORGANIC SLUDGE LAGOO tANDFILL UPGRADIENT DOWNGRADIENl UPGRADIENT J DOWNGRADIENl
COMPOUND (in uqfl) FREO.I MAX CONC FREO.IMAX CONe FREO. MAX CONq FREO.I MAX CONC FREO. MAX CONd FREO. MAX CONC
1,1-DICHLOROETHANE 6/9 300 2115 11 6/114 100
" 1-DICHLOROETHENE 2/9 100 1/15 1.2 3/114 49 1/38 5.00
1,1,1- TRICHLOROETHANE 1/9 130 5/15 33 1/7 2 1/38 2.00
1,1,2- TRICHLOROETHANE 1/9 59
1,1,2,2- TETRACHLOROETHANE
1,2-DICHLOROBENZENE 215 28000 7/43 5200 1/11 2.00
1,2-DICHLOROETHANE 1/9 620 4/114 470
1,2-DICHLOROETHENE (1,2-DCE) 6/9 36000 3/15 31 1 0/38 13.00
1,2-DICHLOROETHENE (TOTAL) 27/1 14 19000 4/11 12.00 4/38 21.00
1,2-DICHLOROPROPANE 1/114 2
1,2,4- TRICHLOROBENZENE
1,3-DICHLOROBENZENE 2/5 950 4/43 2100 1/38 9.00
1,3-DICHLOROPROPENE (CIS) 1/119 0.500
1,4-DICHLOROBENZENE 215 13000 3/5 120 7/43 2600 1/11 3.00
1,4-PENTADIENS, 2,3,4-TRIMET
11 H-CYCLOPENTAIAIPHENANTHREN
1 H-INDENE, OCT AHYDRO-2,3A,4-
2-BUTANONE 4/9 890 3/15 120 10/11 15000 2138 9.00
2-FURANMETHANOL, 5-ETHENYL TE
2-HEXANONE 1/15 8.2 2/114 40
2-METHYLNAPHTHALENE 2/43 64
2,4-DIMETHYLPHENOL 3/8 11000 6/69 2200
3,4-BENZOFLUORANTHENE 1/38 3.00
3-HEXENE-2,5-DIONE
4,4'-DDD 4/5 12 3/3 7 1/38 0.07
4,4'-DDE 2/5 0.26 3/3 5 1/11 0.03 2/38 0.08
4,4'-DDT 4/5 8 213 0.1 1/38 0.05
-
4-CHLOR0-3-METHYLPHENOL
4-METHYL-2-PENTANONE 2/9 650 1/15 6.6 1/7 56 5/112 420
ACENAPHTHENE 1/5 15
ACENAPHTHYLENE
-------
TABLE 2 (Cant.)
DETECTIONS OF ANAL YTES IN LIQUID MEDIA
OMPOUNDS DETECTED IN SOURCE AREA LEACHATE* GROUNDWATER* SURFACE WATER
T LEAST: ONE MEDIUM
'RGANIC SLUDGE LAGOO LANDFILL UPGRADIENT DOWNGRADIENl UPGRADIENT DOWNGRADIEN
'OMPOUND fin uQ/l) FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC
CETONE 7/9 4300 9/14 61 49/1 14 13000 3/11 30 11/38 50
LDRIN
NTHRACENE
ZULENE, 1,4-DIMETHYL-7-(1-M
ENZENE 7/9 660 11/15 85 2/7 13 81114 91 1/11 3.00
ENZO A)ANTHRACENE 1/38 3.00
ENZO A)PYRENE 1/38 3.00
ENZO G,H,I)PERYLENE
ENZO B)FLUORANTHENE 1/38 3
ENZO :K)FLUORANTHENE 1/38 3.00
=NZOIC ACID 1/16 8 3/38 10.00
=NZVL ALCOHOL 2138 3.00
CYCLO(2.2.1)HEPTAN-2-0L. 1
CYCLO(2.2.1)HEPTAN-2-0NE
S 2-CHLOROISOPROPYL)ETHER 1/43 2.50
S 1,1-DIMETHYLETHYL)PHENOL
S 2-ETHYLHEXYL)PHTHALA TE 1/5 14 215 660 16/43 26 8111 30.00 13/38 120.00
JRNEOI (8CI)
=tOMODICHLOROMETHANE 1/9 1 9/38 5.00
JTYLBENZVLPHTHALA TE 3/43 2
~MPHENE (DOT) (8CI)
~RBON DISULFIDE 4/114 29 4/38 5.00
<\RBON TETRACHLORIDE 3/7 110 22/114 83 1138 4.00
~RYOPHYLLENENAN)
-iLORDANE. TECHNICAL 215 0.100 1/3 37.0
-iLORDANE, ALPHA . NA 2138 0.04
-iLORDANE, GAMMA
-iLOROBENZENE 6/9 4000 9/15 150 13/1 14 810 3/11 59.00 4/38 4.00
-iLOROETHANE 1/15 81
-iLOROFORM 219 28 3/15 3 2/7 3 231114 600 20/38 26.00
-iLOROMETHANE .. 1/114 3 1/38 29.00
-iRYSENE 1/38 3.00
-------
TABLE 2 (ConI.)
DETECT"IONS OF ANAL YTES IN LIQUID MEDIA
IPOUNDS DETECTED IN SOURCE AREA LEACHA TE* GROUNDWA TER* SURFACE WATER
::AST ONE MEDIUM
ANIC SLUDGE LAGOO LANDFILL UPGRADIENT DOWNGRADIENl UPGRADIENT DOWNGRADIEN
IPOUND (in ug/l) FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC
OLE (VAN)
30L-O 3/7 2200 4/64 290 1/11 0.70
30L-M,P 3/7 7900 4/14 170 4/64 1900 2/38 220.00
_OHEXANE ISOMER NA 2/38 48.00
_OHEXANOL,2-BROMO- TRANS-( NA 1138 18.00
NZO(a,h) ANTHRACENE
TYL PHTHALATE 1/5 550 3/43 3
BUTYLPHTHALA TE 1/38 2.00
OCTYLPHTHALA TE 9/43 16
NZOFURAN
OMOCHLOROMETHANE -.
4/38 3.00
LORO-CYCLOHEXANE ISOMER '
NA 2138 120.00
JRIN 215 0.02 1/7 0.18 2/11 0.02 6/38 0.08'
-iYL PHTHALATE
.IMETHYL-4-NAPHTHALENE
THYL PHTHALALTE
'lBENZENE 5/9 410 7/15 6.3 2/11 6 5/114 70
)RANTHENE 1/5 21 1/38 5.00
IRENE 1/5 17
'ACHLOR
NO(1.2,3-CD)PYRENE 1138 2.00
'METHANE NA 1/38 14.00
ORNEOL(8CI)
~NE. TOTAL (g-BHC) 1/38 0.02
WLENE CHLORIDE 6/9 6000 9/15 110 73/114 19000 3/11 12 12/38 12.00
-ROSODIPHEf.lYLAMINE 1/43 7
iTHAlENE 2/5 560 4/5 30 3/43 50 1/30 0.7
iTHAlENE, 1,2,3,4,4A,5,6
iTHALENE, 1,2,3,4-TETRAHY
iTHALENE, 1,2,4A,5.6.8A-H ,
\DECANAL ISOMER
1254 215 0.7 1/3 100
-------
TABLE 2 (Cont.)
DETECTIONS OF ANAL YTES IN LlaUID MEDIA
;OMPOUNDS DETECTED IN SOURCE AREA LEACHA TE* GROUNDWATER* SURFACE WATER
~ T LEAST ONE MEDIUM
)RGANIC SLUDGE LAGOO LANDFILL UPGAADIENT DOWNGAADIENl UPGRADIENT DOWNGAADIENT
:;OMPOUND (in ugfl) FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC
)CB-1260 -
'ENTACHLOROPHENOL 218 2.6 2115 36 4/69 27 1/38 3.00
'HENANTHRENE 1/5 37 1/38 3.00
'HENOL 4/8 3600 8/15 49 1/1 1 6/68 1700 2138 23.00
'HENOL,2,6-DIMETHOXY -4-(2-
'YRENE 1/5 14 1/43 1.2 1/38 4.00
;TIGMAST -4-EN-3-0NE
HYRENE
"ETRACHLOROETHYLENE 4/9 1100 1115 3.2 117 29 19/114 290 3111 15.00
"OLUENE 6/9 2200 9/15 33 2111 34 18/114 540 1/11 3.00 8/38 ~o.oo
"RICHLOROETHYLENE 6/9 130000 4/15 8.1 717 880 411114 21000 6/11 72.00 23/38 52.00
-RICHLOROFLUOROMETHANE 1/8 5100 9/58 170
'INYL CHLORIDE 5/9 12000 3/15 12 8/114 6700 1/38 2.00
:YlENES (TOTAL) 6/9 2200 9/15 26 317 49 8/112 220 1/38 2.00
-------
TABLE 2 (Cont.)
~
DETECTIONS OF ANAL YTES IN LIQUID MEDIA
SOURCE AREA LEACHATE" GROUNDWATER- SURFACE WATER
SLUDGE LAGOON LANDFill UPGAADIENT DOWNGAADIENT UPGAADIENT DOWNGAADlENT
:TAlS (in ug/l) FREQ. MAX CONC FREQ. I MAX CONC FRED. MAX CONC FRED. MAX CONC FREQ. MAX CONC I FRED. MAX CONC
Uri.1INUM 9/11 7100 46/46 447000 10/11 927.00 22/38 18153.00
ITIMONY 1/46 136
ISENIC 6/6 21000 14/14 13000 1/11 8 18/101 109 5/38 14.41
.RIUM 6/6 1600 14/14 4200 718 98 104/104 3490 10111 362 25/38 678.09
RYLLIUM 4/6 80 8/14 22 9/104 29.1 2/11 0.38 12/38 1.2
..",
)RON 4/11 91.20 13/38 176.00
,DMIUM 6/6 34800 14/14 9300 1/11 7.3 8/101 600 1/11 1.96 9/36 26.67
,LCIUM 9/9 18800 48/48 218000 10/11 36100.00 34/38 67613.00
IROMIUM 6/6 13163000 14/14 66000 2/11 63 39/101 2720 1/11 1.42 12/36 272.94
)BALT 4/46 109 NA 3138 14.11
)PPER 6/6 10600 13/14 3600 45/101 1800 4/11 84.09 18136 135.53
ANIDE 4/6 320 7/14 574 9/101 403 1/38 11.03
IN 8/9 5400 46/46 317000 11/11 1660.00 33/38 37018.00
AD 5/6 60000 14/14 10400 6/11 28 67/101 5240 2/11 7.30 23138 318.00
IGNESIUM 7/9 1310 46/46 23600 10/11 4890.00 34/38 5644.30
INGANESE 10/11 40.7 36/46 5040 6/11 97.42 19138 477.10
:RCUqy 6/6 85 14/14 880 5/11 0.9 20/101 73 2/11 0.33 4138 0.50
~KEL 6/6 15000 14/14 1300 2111 17.8 28/101 17.8 2/11 21.17 8/38 23.63
7/11 7.90 11138 6.70
ITASSIUM 7/9 1970 43/46 32700 6/11 6870.00 33/38 7038.40
LENIUM 216 40 9/14 23 1/11 30 5/101 11.1 4138 1.04
VER 4/6 80 12114 40 3/101 986 8/38 52.45
IDIUM 4/9 5950 40/46 70100 10/11 5140.00 34138 89452.00
LFrDE 10/11 7000 11/46 1.4
LFUR, MOL. (581
ALLIUM 1/6 5 3/14 6 3/101 3.3 NA 1/38 0.70
NADIUM 3/9 2320 13/46 1160 1/11 1.55 13/38 63.32
IC 6/6 64400 14/14 60000 8/11 55.2- 96/101 4600 6/11 492 30138 1242.40
nES:
\ = Not Analyzed.
,nk spaces Indicate compound was analyzed for but not detected.
)at8 from CH2M HIll, 1990.
-------
TABLE 3
DETECTIONS OF ANAL YTES IN SOLIDS MEDIA
COMPOUNDS DETECTED IN SOURCE AREA* SOIL & SEDIMENT
AT LEAST ONE MEDIUM
ORGANIC SLUDGE LAGOON LANDFill LANDFill SOilS UPGRADIENT DOWNGRADIENT
COMPOUND (ug/kg) FREO. MAX CONC FREO. MAX CONC I FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC
1.1-DICHLOROETHANE 3/23 260
1, 1-DICHLOROETHENE 1/23 3
1,1,1- TRICHLOROETHANE 4/11 14.00 5/64 31.00
1.1.2- TRICHLOROETHANE 2/23 400
1.1,2,2- TETRACHLOROETHANE 1/14 1.40
1,2-DICHlOROBENZENE 3/11 1700000 1/5 110 3/64 210.00
1.2-DICHLOROETHANE 1/23 70
1.2-DICHlOROETHENE (1 ,2-DCE) 9/23 100000 3/64 170.00
1,2.DICHlOROETHENE (TOTAL) 5/64 220.00
1.2-DICHlOROPROPANE
1,2,4- TRICHLOROBENZENE 1/11 ~2000
1 ,3-DICHlOROBENZENE 3/11 58000 1/64 9.00
1.3-DICHLOROPROPENE (CIS)
1.4-DICHLOROBENZENE 4/11 690000 2/5 600 1/13 970 4/64 540.00
1.4-PENTADIENS, 2,3,4-TRIMET NA 1/64 12000.00
11 H-CYCLOPENTA(A)PHENANTHREN NA 1/64 9100.00
11 H.INDENE, OCTAHYDRO-2,3A,4- NA 1/64 9500.00
f 2-BUTANONE 6/23 3100 3/14 1100 20/64 920.00
f 2.FURANMETHANOL. 5-ETHENYL TE NA 1/64 4400.00
! 2-HEXANONE 2/14 1400
: 2-METHYlNAPHTHAlENE 6/64 95.00
,
i 2,4-DIMETHYLPHENOL 2/23 120000
: 3,4-BENZOFlUORANTHENE 7/64 1800.00
3-HEXENE-2,S-DIONE NA 3/64 9700.00
4,4' -DDD 3/4 930 1/2 2 . 2/11 20.00 37/64 9000.00
4,4'-DDE 3/4 200 1/2 2 3/11 19.00 47/64 1300.00
4,4'-DDT 3/4 240 1/2 1 1/13 44 2111 27.00 19/64 51000.00
4-CHlORO-3-METHYlPHENOl 1/23 460
4-METHYL-2-PENT AN ONE 1/14 21 1/64 24.00
ACENAPHTHENE 1/11 200 2/5 3800 1/11 25.00 8/64 400.00
ACENAPHTHYLENE 1/11 .20.00 7/64 180.00
-------
TABLE 3 (Cont.)
DETECTIONS OF ANAL YTES IN SOLIDS MEDIA
COMPOUNDS DETECTED IN SOURCE AREA * SOIL & SEDIMENT
A T LEAST ONE MEDIUM
ORGANIC SLUDGE LAGOON' LANDFILL LANDFILL SOILS UPGRADIENT DOWNGRADIENT
COMPOUND (ug/kg) FREQ. MAX CONC I FREO. I MAX CONC FREO. MAX CONC FREO. MAX CONC FREO. I MAX CONC
ACETONE 4/8 630 5/7 2100 2/13 320 6/11 630 38/64 22000
ALDRIN 1/4 2.6 17/64 840.00
ANTHRACENE 2/11 600 1/5 6400 2/11 39.00 15/64 830.00
AZULENE.1.4-DIMETHYL-7-(1-M NA 2/64 1 JOOO.OO
BENZENE 5/23 2800 2/14 1.7 1/11 1700.00 6/64 54.00
BENZO A)ANTHRACENE 2/11 2700 2/5 300 3/11 520.00 20/64 2000.00
BENZO A)PYRENE 2/11 2200 3/5 400 3/11 530.00 28/64 2300.00
BENZO G,H.I)PERYLENE 2/11 1300 1/5 200 1/11 74.00 10/64 1200.00
BENZO(B)FLUORANTHENE 2/11 2700 3/5 400 1/13 110 3/11 720.00 14/64 790.00
~ENZO(K)FLUORANTHENE 2/11 1600 1/5 300 3/11 600.00 21/64 2000.00
BENZOIC ACID 1/13 210 6/64 10000.00
BENZYL ALCOHOL 1/64 77.00'
BICYCLO(2.2.1)HEPT AN-2.0L, 1 NA 2/64 900.00
BICYCLOI2.2.1IHEPTAN-2-0NE NA 2/64 3300.00
I BIS(2-CHLOROISOPROPYL)ETHER
,BIS(1.1-DIMETHYLETHYL)PHENOL NA 5/64 1700.00
'BIS(2-ETHYLHEXYL)P~THALA TE 3/11 76000 3/5 4300 5/13 590 3/11 48000.00 17/64 16000.00
..
BORNEOL (8CI) NA 4/64 5900.00
--
BROMODICHLOROMETHANE
BUTYLBENZYLPHTHALATE 2/11 7100 1/5 600 12/13 200 1/11 27.00 1/64 72.00
CAMPHENE (DOn (8CI) NA 2/64 8500.00
CARBON DISULFIDE 1/23 3 1/14 2 2/64 530.00
CARBON TETRACHLORIDE
CARYOPHYLLENENAN) NA 7/64 5300.00
CHLORDANE (TECHNICAL) 3/4 8500 2/2 940
CHLORDANE, ALPHA 1/13 49 NA 8/64 30.00
CHLORDANE, GAMMA 1/13 53 5/64 16.00
.. 4/11 25000.00 10/64 220.00
CHLOROBENZENE 8/23 20000 2/14 11 2/13 52
,CHLOROETHANE
I CHLOROFORM 6/23 17000 1/14 2 1/64 3.00
! CHLOROMETHANE 1/11 22.00
-------
TABLE 3 (Cont.)
DETECTIONS OF ANAL YTES IN SOLIDS MEDIA
COMPOUNDS DETECTED IN SOURCE AREA* SOIL & SEDIMENT
AT LEAST ONE MEDIUM
ORGANIC SLUDGE LAGOON LANDFILL LANDFILL SOILS UPGRADIENT DOWNGRADIENT
COMPOUND (uq/kg) FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC FREO. MAX CONC FREO. I MAX CONC
CHRYSENE 2/11 3100 3/5 300 3/11 890.00 22/64 2100.00
CINEOLE (VAN) NA 26/64 110000.00
CRESOL-O 2/21 13000
CRESOL-M.P 2/21 50000 4/13 1800 1/13 70
CYCLOHEXANE ISOMER
CYClOHEXANOL,2-BROMO- TRANS-(
DIBENZ6fa,h) ANTHRACENE 2/11 400
DIBUTYl PHTHALATE 2/11 35000 2/5 3100 13/13 650
DI-N-BUTYlPHTHALA TE 1/11 23.00 2/64 550.00
DI-N-OCTYLPHTHALA TE 5/64 490.00
DIBENZOFURAN 6/64 160.00
DIBROMOCHlOROMETHANE
DICHlORO-CYClOHEXANE ISOMER
DIELDRIN 2/4 200 1/2 1 1 5.5 32/64 2900.00
DIETHYl PHTHALATE 1/11 600 1/5 170 13/13 150 1/64 19.00
1.6-DIMETHYl-4-NAPHTHAlENE NA 16/64 33000.00
DIMETHYL PHTHALAl TE 1/64 150.00
ETHYLBENZENE 8/23 5600 4/14 14 2/13 9 1/11 71.00 1/64 3.00
FLUORANTHENE 5/11 4800 3/5 1500 5/11 1500.00 41/64 4100.00
FLUORENE 1/11 200 1/5 3100 2111 20.00 11/64 360.00
HEPTACHLOR 1/4 2
INDENOl1 ,2,3-CD)PYRENE 2/11 1400 1/5 200 1/11 72.00 14/64 1100.00
IODOMETHANE
ISOBORNEOL (8CI) NA 1/64 2900.00
LINDANE, TOTAL (g-BHC) .
METHYLENE CHLORIDE 6/7 950 2/2 130 13/13 120 4/11 11.00 20/64 250.00
N-NITROSODIPHENYLAMINE 1/11 85 1/64 95.00
NAPHTHALENE 6/11 80000 3/5 2100 4/64 87.00
NAPHTHALENE, 1.2.3,4.4A.5.6 NA 10164 , 5700.00
NAPHTHALENE. 1,2.3.4- TETRAHY NA 13/64 17000.00
NAPHTHALENE, 1,2.4A,5.6.8A-H NA 7/64 13000.00
-------
TABLE 3 (ConI.)
DETECTIONS OF ANAL YTES IN SOLIDS MEDIA
COMPOUNDS DETECTED IN SOURCE AREA * SOIL & SEDIMENT -
A T LEAST ONE MEDIUM
ORGANIC SLUDGE LAGOON LANDFILL LANDFILL SOILS UPGRADIENT DOWNGRADIENT
COMPOUND (ug/kg) FREO. MAX CONC FREO. MAX CONC FREO. I MAX CONC FREO. I MAX CONC FREO. MAX CONC
OCTADECANALISOMER NA 1/64 310.00
PCB-1254 2/4 2500 1/2 500
PCB-1260 1/4 36.0
PENTACHLOROPHENOL
PHENANTHRENE 3/11 2900 4/5 5800 3/11 740.00 24/64 3200.00
PHENOL 2/23 18000 3/14 200
PHENOL,2,6-DIMETHOXY -4 -(2- NA 2/64 6100.00
PYRENE 3/11 3GOO 3/5 1000 5/11 1800.00 44/64 3200.00
..
STIGMAST -4-EN-3-0NE NA 2/64 2000.00
STYRENE 1/64 11.00
TETRACHLOROETHYLENE 5/23 59000 1/11 11.00 7/64 75.no
~-
TOLUENE 13/23 20000 5/14 43 13/13 250 1/11 6 10/64 120.00
-
TRICHLOROETHYLENE 3/23 2500000 2/11 13.00 8/64 220.00
TRICHLOROFLUOROMETHANE 1/21 68000
VINYL CHLORIDE 1/23 110
XYLENES (TOTAL) 8/23 38000 7/14 110 1/13 4 1/11 310.00 5/64 42.00
-------
TABLE 3 (Cont.)
SOURCE AREA * SOIL & SEDIMENT
SLUDGE LAGOON LANDFILL I LANDFILL SOILS UPGRADIENT DOWNGRADIENT
METALS (mg/kg) FREO. MAX CONC FREO. MAX CONC I FREO. MAX CONC FREO. MAX CONC FREO. I MAX CONC
ALUMINUM 13/13 7870 11/11 25900.00 64/64 44600.00
ANTIMONY 2/13 5.8
ARSENIC 22/23 45 14/14 12 5113 1.9 2/11 3300 14/64 69.00
BARIUM 23/23 387 14/14 202 13/13 57.3 10/11 228 63164 281.00
BERYLLIUM 6/23 1.00 1/14 0.29 2/11 1500 14/64 1.46
BORON 1/64 35.10
CADMIUM 20/23 599 13/14 15 1113 18.7 2/11 208.00 23/64 20.50
CALCIUM 13/13 3470 8/11 1030.00 63/64 20400.00
CHROMIUM 23/23 6419 14/14 52 12/13 153 11/11 1080.00 59/64 219.00
COBALT 8/13 3.5 NA 13/64 0.01
COPPER 23/23 722 12/14 55 12/13 33.4 8/11 178.00 21/64 156.00
CYANIDE
IRON 13/13 7230 11/11 29900.00 64/64 69700.00
LEAD 22123 972 14/14 155 13/13 122 11/11 451.00 64/64 440.00
MAGNESIUM 13/13 2000 8/11 2020.00 64/64 1700.00
MANGANESE 13/13 121 4/11 186 19/64 0.16
MERCURY 14/23 1.1 10/14 0.1 6/11 0.86 57/64 1.30
NICKEL 20/23 203 11/14 8 2113 6.1 2111 68.00 12164 117.00
PH 5/11 6.80 37/64 7.80
POTASSIUM 3/11 1230.00 16/64 1190.00
SELENIUM 4/23 0.6 5/14 0.7 22/64 42.40
SilVER 14/23 45 7114 6 1/13 4.3 1/11 60.70 19/64 49.70
SODIUM 13/13 57.2 1/11 130.00 24/64 2150.00
SULFIDE 7/11 12.10 38/64 591.00
. SULFUR, MOL (S8) NA 6/64 14.00
I THAlUUM 1/23 0.76 NA 3/64 0.00
. VANADIUM . 13/13 18.7 4/11 69.7 19/64 0.07
ZINC 23/23 1091 14/14 457 12/13 . 124 10/11 297.00 60/64 954.00
NOTES:
NA = Not Analyzed.
Blank spaces indicate compound was analyzed for but not detected.
* Data from CH2M Hill, 1990.
-------
The general trends in compound concentrations downgradient of the landfill and sludge
lagoon are consistent with the conceptual model of flow presented previously. Groundwater
present in the shallow fill aquifer within the landfill and sludge lagoon appears to migrate
laterally, discharging directly into the wetlands peat and surface water, and vertically into
the underlying alluvial gravel and Providence Formation aquifers. Due to the high organic
content of the wetlands peat deposits, it is expected that organic compounds present in the
shallow fill groundwater would be adsorbed within a short distance from the landfill or
sludge lagoon. DDE and dieldrin are present in wetland soil samples (Figure 7 and 8) at
relatively high concentrations in a band parallel to the downgradient edge of the landfill. In
contrast, metals compounds are present in a more widespread distribution within the Zone I
wetlands. This may be due to slightly acidic conditions present within the wetlands, which
enhances metals mobility, and because adsorption onto organic matter is not as significant an
attenuating mechanism for metals as it is for organic compounds. Figures 9 and 10 show
approximate areal extent of contamination above remediation levels in wetlands soil and
aquatic sediment in the study area for dieldrin, mercury, and metals. Tables 4 and 5 present
1a summary of criteria used to select chemicals of concern for the ecological risk assessment.
A total of ],36 chemicals, 109 organics and 27 inorganics, were detected in all media. Thirty
compounds had the highest detected values within a sample media in upgradient locations. A
total of 121 chemicals detected at downgradient locations were determined to be potentially
attributable to Landfill No.4 and the sludge lagoon. Further analysis revealed, however,
that 25 of the chemicals detected in downgradient surface water and 32 of the chemicals
detected in downgradient soil/sediment were not present in landfill or sludge lagoon source
area samples. Further, many of these chemicals were detected only once or twice. The
compounds detected only in downgradient sampling locations are considered to be either
naturally occurring or are degradation products from some of the compounds detected in the
Zone I landfill and sludge lagoon.
31
-------
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PERABLE UNIT 2
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-------
ROBINS AIR FORCE BASf RUNWAYS
1000 0 100
SCALE IN TEE!
LEGLND
) UERCUHY (.ONIAMlNAIlUH
DlllllKIN CONIAHINAIION
DM FT'.DKKAI. I'R( H;K AMS CORlftRATION
APPROXIMATE AREAL EXTENT OF WETLANDS SOIL CONTAMINATION
VE REMEDIATION LEVELS
ONE 1, OPERABLE UNIT 2
ROBINS AFB, GEORGIA
FIGURE No.
-------
Ml IAIS CONIAMINAIION
APPROXIMATE AREAL EXTENT OF AQUATIC SEDIMENT CONTAMINATION
ABOVE REMEDIATION LEVELS
RI/FS ZONE 1, OPERABLE UNIT 2
ROBINS AFB, GEORGIA
>M FEDERAL PROGRAMS CORPORATION
•4* My ol C«m> On UK * MelU* Inc.
FIGURE No. 10
-------
TABLE 4
SUMMARY OF CRITERIA USED TO SELECT CHEMICALS OF CONCERN FOR ECOLOGICAL RISK ASSESSMENT
SURFACE WATER
RifFS Zone I, OU 2
Robins AFB, Georgia
Mulmum
DoWDgr.dieot A WQC8
CODCelltr.tioa Acute/Chronic GWQC. Biocoaceotntioa
Chemic. I (Pg/L) (Pg/L) "gtL Potential Pt'nislmct'/Mobilit1~ Decision
ORGANICS
Bis(2 -elhy Ihex yl)phthalale 120.0 940/3 5.92' Low High/Low Retain-Maximum concentration is
significantly above the chronic AWQC.
Chlorofonn 26.0 28,900/1,240 470.8' Low Low/High Omit-Maximum concentration is well
below the A WQC and biocom:entratinn is .
not known to occur.
1,2-Dichloroethene 21.0 1I,600/NN NA Medium Low/High Omit-Maximum concentration is three
orden of magnitude below the acule
AWQC.
Dieldrin 0.08 2.5/0.0019 0.0019' High High/Low Retain-Maximum concentration is above
the chronic A WQC and bioconcentratiun
potential is high.
Phenol 23.0 10,200/2,560 NA Low Low/High Omit-Maximum concenlration is well
below the chronic A WQC.
Toluene 30.0 I1.Soo/NA 301,941' Low Low/High Omit-Maximum concentration is well
below the A WQC and OWQC and
.. bioconcentralion is nol known 10 Occur.
INORGANICS
Arsenic 14.41 360/190 SOl Low. High/Low Omit-Maximum concentration an order of
magnitude below the chronic A WQC. and
less than half of the OWQC.
626\ROBINS AFB\6-J.T8L
11111192 IIpIt
-------
~ TABLE 4
SUMMARY OF CRITERIA USEI> TO SELECT CHEMICALS 01' CONCERN FOR ECOLOGICAL RISK ASSESSMENT
SURFACE WATER
RifFS Zone I, OU 2
Robins AFB, Georgia
Maximum
nowngradient A WQC'
Concentration Acute/Chronic GWQC' Bioconceotration
Cheminl (PR/I.) (pg/I.) pg/L Potential Persi..trnce/Mobility. Decision
INORC;ANICS (Cont.}
Barium 678.f19 NA/NA NA NA High/low Omit-Barium would likely be present in
the nontoxic insoluble form in most
surface waters, and wlluld have 10 he
present at SO mg/l to hc toxic 10 aqualic
life (USEPA 1986a).
Bcryllium I.:!O 13015.3 0.117' NA High/Low Omil-Maximum concenlralion is below Ihe
chronic AWQC and hioconcenlralion is
not known to occur.
Cadmium 26.87 39111 0.71 High High/low Retain-Maximum concentration is above
the chronic A WQC, close to Ihe acule
AWQC. and consid..,.lbly higher than
GWQC and hioconccnlration is known 10
occur.
Chromium (10101) 72.94 16/11 1201 low High/low Retain-Maximum concentration is ahove
(for CrVI) (1IIIal) Ihe AWQC for CrVl, and close 10 the
GWQC.
Lead 318.0 34/1.3' 1.31 Medium High/Low Retain-Max.imum concentralion is well
above the A WQC and GWQC and
bioconcenlration is known to occur.
Mercury (Iotal) I~ ,() 2.4/0.012 0.0121 High Highllow Retain-Maximum concenlralion is above
Ihe chronic A WQC and bioconcenlration
is significant in aquatic life.
. .
d911ROBINS AFBITACl.ESI6-J.TBL
07l2dJ92 od'.
-------
TABLE 4
SUMMARV OF CRITERIA USED TO SELECT CIIEMICALS OF CONCERN FOR ECOLOGICAL RISK ASSESSMENT
SURFACE WATER
RifFS Zone I, OU 2
Robins AFB, Georgia
Maximum
Downgradient A WQC"
Coocentration AcutrlChroaic: GWQC" Bioconceatratioa
Chemic:al (Pg/L) (pg/l.) "g/l. Potential' Penistence/Mobility. Decision
INORGANICS (Cont.)
Nickel 23.63 I ,100/564 88' Medium High/Low Omit-Maximum concentration is less than
half the chronic AWQC.
Selenium \.04 260/35 5' NA High/Low Omit-Maximum concentration is below the
A WQC and bioconcentration is not knuwn
to occur.
Silver 52.45 4.1/0.12 0.12' NA High/Low Retain-Maximum concentration is above
the A WQC and GWQC. .
linc 1,242.40 65/S94 6()1 High High/Low Retain-Maximum concentration is well
above the A WQC and GWQC.
. Source: USEPA 19800.
. PersistenceIMobility:
Quality Cr;l~r;a for Waur /986, EPA/440/S-86-OO1 Office of Water Regulations and Standards. Washington, D.C.
Persistence is described by a qualitative estimate of how long the chemical will remain in the environment.
Mobility is described by a qualitative estimate of how readily the chemical wiu move away from its fant .ite of dcpo.ition.
compounds, no appruiablc deposition may takc place.
For volatile
. NA = Not Available
4 Toxicity of this chemical is dependent on hardness. A mean hardness of 55 mg/L was determined from surface water sample. used in bioas..y tests, therefore, the
AWQC reported is adjusted for a hardness of SO mgIL (USEPA 19868).
. Georgia 'water Quality Criteria (GDNR 1991)
f Annual Average Flow Criterion
. Low Row Criterion
4~I\kIlIlINS A~II\TAIIIJ:.s\().].T8L
0111AN1. cd
-------
~ TABLE 5
SUMMARY OF CRITERIA USED TO SELECT CHEMICALS OF CONCERN FOR ECOWGICAL RISK ASSESSMENT
SOIL AND SEDIMENT
RIIFS Zone I, OU 2
Rohins AFB, Georgia
Maximum
OownanHlient
COlII(eatntioa Poteatial SeJec:ted Toxicily Values
Cbemical (ms"'g) Bioac:clDDuiatioo PenisteucelMobility" Delcriptioa: Value, species Decisioa Refen!DCe
ORGANICS
2-8utanone 0.920 Low Low/High Oral LD...: 3,980 mg/kg/day; rat Omit USEPA 1976
Carbon disulfide O.SJO Low Low/High NAc Omit -
4.4'-DDD 9.0 High Jligh/Low NOEL': 50 mg/kg body weight; rat Relain IARC 1973
4,4'-DDE U()O lIigh lIighlL,w LOAEL": 0.20 mg/kg.bw/day in diet; Retain l.Amgcorc &. Sam...n 1973
black duck (Avt's. Ans..,tj"m,t's)
4,4'-DDT 51.0 High High/Low NOAEL': 0.34 mg/kg-bw/day; pheasant Retain Hunt et al. 1969
1.2-Dichl..mbenzenc 0.21 Medium McdiumIMedium NOEL: 188 mglkg/day; ra' Omit Clayton &. Clayton 1981-1982
1,4-Dichlorobenzene 0.540 Medium MediumIMedium NOEL: 150 mglkg/day; rabbit Omit Gainca 1986
1.2-Dichloroc:thenc 0.170 Medium Low/High NOEL: 1,000 mg/kg/day inhalation; Omit ACGIH 1986
rat, rabbit, dog
Dieldrin 2.90 High High/L,w NOAEL: 0.05 mg/kg/dlY; barn owl Retain Mendenhall et II. 1983
(Avt's. SIrigifonnt'S)
8en1.U(a)ryrene 2.30 lIiKh lIigh/Luw LOAEL: 40 mg/kg; rlt Retain IARC 1973
Phthalatcs O.SSO Low High/Low NOEL: 1,300 mg/kg/dlY in diet; dog Omit KnuakO(lf 1973
Tetrachlorocthenc (PCE) 0.075 L,w Low/High NOEL: 2,000 mg/kg/day inhalation; rat Omit Clayton and Clayton
19111-19112
Toluene 0.120 L,w Low/High NA Omit
-.. .....-
I.I,I-Trichloroethane 0.031 Low Low/High LOAEL: 500 mg/kg/day inhalation; Omit U~I) . i'/Mt
mice
Trichlorocthenc 0.220 Low Low/High NOEL: 70 mg/ltg/day inhalation; rat Omit Verachuercn 19113
627\R081NS AF8\f>.'.TI!1.
11111/92 Iq>b
-------
TABLE 5
SUMMARV OF CRITERIA USED TO SELECT CHEMICALS OF CONCERN FOR ECOLOGICAL RISK ASSESSMENT
SOIL AND SEDIMENT
RifFS Zone I, OU 2
Robins AFB, Georgia
Maximum
Dowuaradieat
COlICstr.tioa Poteatial Setected Toxicity VMI-
CbemiCilI (mllkl) Bio8CC1llllul8tiou PersisteoceIMobility0 Descripcioa: Vahae,.pedes Dec:isioa Ref'ereace
INORGANICS
Arsenic 69.0 Medium High/Low to Moderate NOAEl.: 1.2 mg/kg-bw"Jay; lIog Retain Byrun et al. 1'./67
Barium 281.0 NA High/Low NA Omit
Mercury 1.30 nigh High/low NOAEL: O.OH mg'"gMay; mallard Relain ndOL J './74
Ni"lel 0.117 NA High/low NOAEl.: 2.5 mg'lg; Rat Omi, Amhruse d a!.. 1'./76
Selenium 42.4 NA High/Low NOAEl.: 10 mg/kg; swine Relain Herigslad et al. 197 J
Zin" '154.0 nigh nigh'lA.w NOAEl.: 1110 mg'kg; ral Relai" Schlicker a"d C". 196K
PenistencelMobilily:
Penistence is described by . qualitalive eslimale of how long tile chemical will remain in tile environment.
Mobility is descrihed by a qualitative uti mate 01' how readily tile chemical will move away fmm ils lirst Silc of dc"",ili"".
a""reciahle de""sili,," may take "lace.
ulha' do.e for 50% of tile e.posed organisms al a -re"ili" lime "f "hscrvati"/I.
Data Not Available
No observed elTecllevel
Low,,"1 "hserved adverBe en."1 level
No "hserved allvo:rsc elTccl level
Fur volalilc ,,,m,,"..nll.. ""
LD..
NA
NOEL
LOAEL =
NOAEL =
()2"IUI"IN~ A~"II" T"I.
11111/\/2 kpb
-------
5.6 CONTAMINANTS OF CO~CEIU~
The Baseline Risk Assessment (RA) conducted for the Zone 1 RI completed in 1990
identified the following contaminants of concern (COCs):
. Carbon Tetrachloride
. 1,2-Dichloroethene.
. Tetrachloroethene
. Vinyl chloride
. Arsenic
. Cadmium
. Chromium
. Lead
The Ecological Risk Assessment (ERA) conducted for the Zone I, OU2 RI completed in
1992 identified the following contaminants of concern related to OU2 ecological receptors.
Surface Water
. Bis(2-ethylhexyl)phthalate
. Dieldrin
. Cadmium
. Chromium
. Lead
. Mercury
. Silver
. Zinc
Soil! Aquatic Sediment
. Benzo(a)pyrene
. 4,4' DDD, DDE, DDT
. Dieldrin
. Arsenic
. Mercury
. Selenium
. Zinc
.1t1
-------
6.0 SUMMARY OF SITE RISKS
6.1 HUMAN HEAL TII RISK ASSESSMENT
A human health risk assessment was completed as part of the Zone 1 RI in 1990. The
human health risk assessment identified two potential current human exposure pathways and
estimated the risk associated with each. These two exposure pathways are the potential for
inhalation of contaminated dust particles and volatile organic compounds for onsite
trespassers and offsite residents and ingestion of contaminated soil, sediment, and surface
water for on site trespassers. The first pathway was residential inhalation; risk estimates
suggested an excess lifetime cancer risk of 3 x l~ fQr inhalation of contaminated dust
particles and 2 x l~ for inhalation of VOCs or a cumulative estimated risk level of 5 x l~.
The second exposure pathway is incidental ingestion of contaminated soil, sediment, and
surface water. The maximum estimated risk for this exposure route was 9 x 1~ for the
incidental ingestion of sediment by child trespassers. The risk associated with these
pathways is an acceptable risk under the NCP (10-7 to lQ-4).
Human health risks associated with aquatic sediment, wetland soil, and surface water
ingestion were reassessed based on data collected from locations downgradient of Landfill
No.4 and the sludge lagoon during the Zone 1, OU2 RI field investigation. Hazard Indices
did not increase significantly as a result of the reassessment. Carcinogenic risks for arsenic
in wetland soil and for arsenic and dieldrin in aquatic sediment were higher than risks
presented in the initial human health risk assessment, but still within EPA's acceptable range
(1 x I ~ to 1 x 1 Q-4). .
Tables 6 through 11 illustrate comparisons of initial (CH2M Hill) and reassessed (CDM)
hazard index and carcinogenic risk values.
42
-------
~ TAULE 6
COMPARISON OF CU2M IIILL AND CUM ESTIMATES OFIIAZARD INDICES
FOR INGFSTION OF WETI..AND SOIL.
RifFS Zone I, OU 2
,Robins AFB, Georgia
lIighest Deteaed .. ;
Highest Detected Downgndient
Reference Concentnition" Concentration
Dose (RID) (CH2Prt IRLL) (COM) ; .. .. . Hsmrcllndex Hazard Index
Chemical (mg/kg/day) Sourceb . (pglkg) (pglkg) . (CIUM mLL) :.~' (CDM)"
Antimony 0.0004 IRIS 5,800 - 0.041429 -
Barium 0.05 IRIS 57,300 281,000 0.003274 0.016
Benzoic acid 4 IRIS 210 10,000 0.00000o 0.00000
D is(2 -ethy Ih ex yl )phthal ate 0.02 IRIS 590 16,000 0.000084 0.0023
Butyl henzyl phthalate 0.2 HEAST 200 - 0.000003 -
Cadmium 0.001 IRIS 18,700 20,500 0.053 0.058
f:hlordane 0.00006 IRIS 102 30 0.004858 0.0014
Chlorobenzene 0.021 SPHEM 52 220 0.000008 0.000034
Chromium VI 0.005 IRIS 153,000 219,000 0.087429 0.13
Copper 0.037 SPHEM 33,400 156,000 0.
-------
TABLE 6 (Cont.)
COMPARISON 01<' CU2M IIiLi. ANI) CUM ESTIMATI'.S OFIIAZARD INDICES
FOR INGESTION OF WETLAND SOIL.
RifFS Zone I, OU 2
Robins AFB, Georgia
llighest Detected
. Concentration:
(ClllM HILL)
.. . (pglkg). .. ~
122,000
121,000
70
Highest Detected"
. Downgradlent .
Concentration
(CDM) .
(pg/kg)
360,000
160
0.00346
0.00000o
0.002457
0.000003
. Chemical
Reference
Dose CltID)
(inglkgiday)
0.0014'
IRIS
IRIS
IRIS
IRIS
Sourceb
Lead
Manganese
4-Methylphenol
0.1
0.5"
Silver
0.005
0.2
0.009
IRIS
IRIS
Toluene
Vanadium
X ylenes
Zinc
2
0.2
IRIS
HEAST
. Exposure Assumptions
Exposure Setting
Exposure Individual
Soil Intake (grams/day)
Body Weight (kilograms)
b Soun:~ of RIDs:
IRIS - Integrated Risk Information Sysh:m USEPA (1992a).
SPHEM - Superfund Public Health Evaluation Manual USEPA (1986b).
HEAST - Health Effc:cts Assessment Summary Tables - USEPA (1992b).
" ND = Not Detectc:d
. RFD currently withdrawn p~nding review (USEPA 1992).
Tr~spass
Child
0.1
35
"JIlIU IIIINS'T"III..ESU-I. Till.
01/21/'12 mlh
Hazard Index
(CIUM mLL)
0.248980
4,300
250
18,700
ND"
49,700
120
70
42
0.00594.
0.000000
0.001711
4
124,000
954,000
lIazard Index
(COM): .
0.74
0.0000046
-
0.0028
0.0000014
0.000022
0.00000
0.014
-------
~TA8LE
7
COMPARISON OF CH2M lULL AND CDM ESTIMATES OF CARCINOGENIC RISKS
)4,,()R INGESTION OF WETLAND SOIL"
RI/FS Zone I, OU 2
Robins AFB, Georgia
m hat}:)
.' I
.' Highest Downandient .
USEPA Carcinogenic COriCeitntiOD ConcentrBlion
CarcinOgen Potenc)' rador (CtUM IfIL~) : (CDM)..;;
Chemical Classification j: (Ice-day/mg) ; Soura' : (pg/kg) : :: . (jaglki)
Arsenic A 1.15 HEAST 1,900.0 69,000
Benzo(b)nuoranthene B2 11.5 . 110.0 1,800
Bis(2 -ethylhex yl)phlhalate B2 0.014 IRIS 590.0 16,000
Chlordane 82 1.3 IRIS 102.0 30
DDT 82 0.34 IRIS 44.0 110
1,4-Dichlorobenzene 82 0.024 HEAST 910.0 540
, .
Exposure Assmnptions
Exposure Setting
Exposure Individual
Daily Soil Inl,.ke (grams/day)
Body Weight (k.ilograms)
Number of d;.ys/week. exposed
Number weeks/year expose
Number of years exposed
Lifetime Average Soil Intake
(gramsltcg body wt./day)
Trespass
Otild
0.1
3S
2
16
10
0.000036
II Sources of Cancer P"lt'ncv , .
IRIS - Inlr.rr,II...!: .: ;,.llmatJOO System USEPA (19918).
SPHEM - Superftmd l'tlMic Health Evaluation Manual USEPA (1986b).
HEAST - Health Eff~cls Assc:ssment Summary Tables - USEPA (l992b).
. Based on benzo(a)pyrene.
.9I\ROBINS\T"IILES~.2,TBL
07mm ....
....
. .....
. Ex~
CL~k
(CIl1~L)
1.19 I( 10.1
4.64 X 10"
2.96 I( 10,10
4.161( 10.\1
5.31 I( 10,,0
8.35 X 10,10
..
ExCess
lJfetinie
cancer Risk
:. ;:(CPM):)
4.3 I( 10-4
1.6 X 10,7
8 I( 10'\1
1.6 I( 10'
2.1 X 10.10
I )( 10.\1
-------
Chemical
Aldrin
Antimony
Arsenic
Barium
Benzo(g,b,i)perylene
Beryllium
Bis(2 -ethylhex yl)phthalale
Bromodichloromethane
2-Butanone
Butyl benzyl phthalale
Cadmium
Carbon disulfide
Chlordane
Chlorobeozeoe
Chlorofonn
Chromium VI
491 IROBINSI T" BLESI.). 3. TBL
01127/'12 mIh
TABI.E 8
COMI)ARISON OF CII2M 1111.1. ANU CUM ESTIMATES 01' ((AZARI) INDICES
FOR AQUATIC SEDIMENT INGKSTION"
lUfFS Zone I, OU 2
Robins AFB, Georgia
:'\,,', ,..
, Reference
nose' (RID)
(mglkg/day)
o .()()()()]
0.0004
3.0003
0.05
o '()O4"
0.005
0.02
0.02
0.05
0.2
0.001
0.1
0.00006
0.02
0.01
0.005
Source.
Highest Detect~
. Concentration'
(CIUp.f fIII+)
, (pglleg) , ,
IRIS
IRIS
6.50
19,300
IRIS
27,200
IRIS
190,000
1,060
HEAST
IRIS
IRIS
1,800
2,790
IRIS
IRIS
20.0
290
640
HEAST
IRIS
21,000
IRIS
IRIS
4.90
180
IRIS
IRIS
380
64.0
IRIS
2]0,000
,
Ilighest ~te4' ,
DowngradieOtCo~centraJion
:, (CD~:..' "
("g/kC)
840
-
69,000
281,000
1,200
1,460
16,000
-
-
-
20,500
5]0
30
220
3
219,000
':,
Jfazant Index
(CIUM HItL)
0.0006
0.1
0.27
0.01
0.0000095
0.001
0.0004
0.000003
0.00002
0.000009
0.05
0.0000001
0.008
0.000054
0.00002
0.1
QQmrct Index
,: : (COM):"
0.08
-
0.68
. .
0.01
0.0000108
0.001
0.002
-
-
-
0.05
0.00001
0.001
0.0000]
0.0000009
0.1
-------
.. .
.,
Chemical
Copper
DDT
Dibutyl phthalate
I,I-Dichloroethene
Dieldrin
Diethyl phthalate
Ethylbenzene
Liad
Manganese
Mercury (alleyl and inorganic)
4-Methyl-2-pentanone
4-Metbylphenol
Naphthalene'
Nickel
Pyrene
Silver
491\ROBINS\T ABLES\s-). TBl
07f21/91 .....
TABLE 8 (ConI.)
COMPARISON OF CII2M HILL AND COM ESTIMATES O.F IIAZARD INDICES
FOR AQUATIC SEDIMENT INGFSfION
RifFS Zone 1, OU 2
Robins AFB, Georgia
Reference
DoSe (RID)
(mg/ki"day)
0.031
0.0005
0.1
0.009
0.00005
0.1
0.1
O.ool:. ..H...: . iluani Index
(pinel) . (CIUM. HILL)
156,000
110
0.001
0.001
-
0.00003
0.00009
-
2,900
0.05
0.000024
-
3
360,000
0.000004
0.5
160
1,300
0.02
0.02
-
0.0000004
0.0000003
-
1,100
0.0005
0.003
20
3,200
0.0005
0.018
49,100
:':.':.
Jfamnlloclex:
. U. (CDM) ;L..
0.01
0.0006
-
-
0.2
-
0.00000OO9
0.8
-
0.0000046
0.01
-
-
0.0013
0.000003
0.0003
0.024
-------
TARLE 8 (Coni.)
COMPARISON OF CH2M lULL AND CDM ESTIMATES OF HAZARD INDICES
FOR AQUATIC SEDIMENT INGESTION
RJ'I<1» Zone I, OU 2
Robins AFB, Georgia
.\>. . flighest DeUmd
Referenee :Concentrallon'
oos.!I(RfQ) (CIU" '1IU.L)
Chemical . (mglki/day) Source" (pglkg) : ,
T etl'8Chloroetheoe 0.01 IRIS 33.0
Toluene 0.2 IRIS 1,200
Vanadium 0.009 IRIS 79,500
Xylenes 2 IRIS 820
Zinc 0.2 HEAST 449,000
. ffig~ J)etecte4:ih:':.,:.;:i,::::.
DowngradiaitColicenir8tion
.. .: (CDM).. :..::.. ~Jnda
(pg/kg) (CfUM.IDLL)
75 o. ()()()()()9
120 0.000015
70 0.023
42 0.000001
954,000 0.006
Exposure Assumptions
Exposure Sening
Exposure Individual
Soil Intake (goms/day)
Body Weight (kilograms)
Trespass
Child
0.1
35
~
Sources of RIDs:
(RIS - Integrated Risk Information System USEPA (1992a).
SPHEM - Superfund Public Healtb Evaluation Manual USEPA (1986b).
HEAST.:... Health Effccts Assessment Summary Tables - USEPA (1992b).
Nickc:l value base on nickc:l-solubh: sa!ls.
d
RID currenlly withdrawn pending review (USEPA 19928).
Villuc is a proxy toxicity value based UPOII naphthah:ne.
4~1\IIUUlN~\ I AIII.J--SU ).1111.
07n7/'12 m1b
. .
~ ",del:
>,. (CDM) '.:
0.00002
0.0000015
0.000023
0.00000oo5
0.01
-------
"TABLE 9
COMPARISON OF CARCINOGENIC RISKS FOR AQUATIC SEDIMENT INGESTION
CALCULATED BY CIUM HILL AND CDM"
RIlIfS Zone " OV 2
Robins AFB, Georgia
'. .;';';.;" ..,:::,:,' ,,:.,:."':-"'.. :.y,\)<.
USEPA Carcinogenic
C_lcal CillrcfnOgen PotenCy Fador
Classification '. (kg-day/mg) ,
Aldrin B2 17.0
Arsenic A 1.15
Benzene A 0.029
Benm(l)anthracene B2 11.5
Oenm(b )nuoranthene 02 11.5
Oenzo(t)nuoranthene B2 11.5
Benm(l)pyrene B2 11.5
Oi$(2-ethylhe1lyl)phthlllllte 02 0.014
Orornodichloromethulll.: B2 0.130
Chlordane 02 1.30
Chlorofonn B2 0.0061
Chloromethane C 0.01]4
Chrysene C 11.5
DDD R7. 0.240
DDH "- 0.340
DDT 02 0.340
Dibenz(a,h)anthracene 02 11.5
1,4-Dichlorobenz.ene B2 0.024
4121ROBI NSIT ABLESI5.4. TilL
07/171
Source. .
llighest J)c)Wnrtalfielit'
: 'ContmJ1:ion .'
, (CIUM'mLL)
'Cpgncg), ' .'
~~~ i\l!.t!
(",lkg):: n: \;' "
. ..
. .. . .
EX_tit"~be
:: C~:RJSk ,
')'.."(COM) H
IRIS 6.50 840 3.911 10"' 5.1 11 10.7
HEAST 27,200 69,000 1.71 ]( 1()4 4.3 ]( 10-4
IRIS 150 54 1.56 ]( 10"10 5.6]( 10.11
. 3,180 2,000 1.31 ]( 1~ 8.2 ]( 10"7
c 4,450 1,800 1.84 ]( 1(}41 8.2 ]( 10'~ .
. 800 2,000 3.301 10"7 8.25 ]( 10"7
SPHEM 2,540 2,300 1.05 ]( I~ 9.5 ]( 10.7
IRIS 2,790 16,000 1.40]( 10"' 8 ]( 10"'
HEAST 20.0 - 9.33 ]( 10"" -
IRIS 95.0 30 4.43 1 10"' 1 x 10"'
IRIS 64.0 3 1.40 1 10"" 6.5 x 10"1)
HEAST 50.0 - 2.33 ]( 10"11 -
. 3,070 2,100 1.27 ]( 1~ 8.7 X 10.7
IRIS 490 540 4.22 x 10"' 4.6 x 10.9
-
IRIS 940 1,300 ", ! f, l' 10"
, I
~ -.... ""--
IRIS 180 110 2.20]( '0"' 1.3 x 10"'
. 650 2.68 ]( 10"1
- -
HEAST 315 540 2.71 x 10"10 4.6 X 10.10
-------
TABLE 9 (Coni.)
COMPARISON OF CARCINOGENIC RISKS FOR AQUATIC SEDIMENT INGESTION
CALCULATED BV CH2M HILL AND CDM
RI/FS Zone I, OV 2
Robins AFB, Georgia
,.:'.
. ",'::.:.".'. ,,"':,.
..'.
C
82
,:",,:,:,'" ':.,.
:':,'. '..'," .:."'.,
Cardnogenic
Poterit1"i~r
:j (kg..tfay/nig) .
O.09ld
..
,.::':".,.,::.: ." .,..", .
.." .. .. n....
,':';'::','::"'.:':':';';':,:,:..".::..:.::;.
"', .'...".Y..':"""",.""'':''''.'''''''''''.<'''''','.
,",,', ',',',' ,,",'", . ",'..",.
.."", ... ..
. 'pS~p,,"
C8iCloogen
Classificalion
".., ,'"
.. .
Chemical
1,1 -Dichloroelbane
Dieldrin
Indeno( 1,2,3-cd)pyrene
Tetrachloroethene
Trichloroethene
. Exposure Assumplions
Exposure Individual
Exposure Sening
Daily Soil Intake (grams/day)
80dy Weight (kilograms)
Number of days/week exposed
Number weeks/year expose
Number of years exposed
Lifelime Average Soil Intake
(gramsllcg body wt.lday
16.0
11.5
82
82
0.051d
O.Olld
,;:-
. . . . .
'E.:i_:'ur~"
tCaU'RJsk: .
:~f'fr1 fflH-)
'Jfajbest. ~cIi~
i ::\Con~tnat.io..:::
, " ," CCJnM:fflLL) :..
" 'CPg/kg): :: ::
.", .
~~~~=~ITf
,:.: (Cn")"': .: . '
(pg!ki) ,
as.ur"""e
:::'~::~k':
: ...: (cpM> ::( .
82
Child
Trespass
0.1
35
2
16
10
0.000036
Soun:c'
HEAST
IRIS
270 - 8.82 J( 10,10 -
880 2,900 5.05 I( JO'1 1.6 It 10-6
1,520 1,100 6.21 x 10-' 4.5 It 10"
33.0 75 6.04 x 10,11 1.4 X IO'I~
32.0 220 1.26 x 10.11 8.1 X 10'11
.
SPHEM
IRIS
b Sourct:s of Canct:r POIt:ncy Faclors:
IRJS - Integnte«t Risk Information System USEPA (19918).
SPHEM - Superfund Public Health Evaluation Manual USEPA (1986d).
HEAST - Health Effc:cts Assessment Summary Tables - USEPA (1mb).
. Basc:d un benzo(a)pyrc:ne.
. Rm (urrcnlly wilhLlr..wn pending review (USEPA 1992).
4121R08INS\T A8LES~4. T81.
07121/92 mlb
-------
-'.'._-._.......... -~ ..~._~....
~ TABLE 10
COMPARISON OF CU2M lULL AND CDM Ij'SfIMATES OF HAZARD INDICES
. FOR INGESTION OF SURFACE WATER"
RIfFS Zone I, OU 2
Robins AFB, Georgia
... ., ..
" . '? MiX,mufii',:\,,):::
" MaximUITI ,.,"..., DoWn 'radhint'..
, .g , p,
Reference Concent1ittlo~ ,...' ConcmtriltJoij
DoSe (Rm) (CfI2M 'fOLL) ','," (CDM) :,), ,.
Chernlal (mglkg/day) 'Source" ' '(pglk T " . (pglkg)
" " '.g '. '. ",,"
Antimony 0.0004 IRIS 72.8 NOC
Arsenic 0.0003 IRIS 12 14.41
Barium 0.05 IRIS 1,360 678.09
Beryllium 0.005 IRIS 3.8 1.2
Bromodichloromethane 0.02 IRIS 3 5.0
2-Butanone 0.05 IRIS II 9.0
Cadmium 0.001 IRIS 128 26.87
Chlorobenzene 0.02 SPHEM 5 4
Chloroform 0.01 IRIS II 26.0
Chromium VI 0.005 IRIS 1,390 72.94
Copper 0.037 SPHEM 856 56.69
Cyanide 0.02 ' 67.1 NO
Lead 0.0014- SPUEM 1,400 318
Manganese 0.1 IRIS 2,700 477.10
Mercury (alkyl and inorganic) 0.0003 IRIS 14 0.5
4911R081NSIT ABJ.I!S\S-'. TBL
I17mm mil
. . .... ..'" .
::~t!~~(..~~~::~tWrrt~~:i:::/~(t~:ft~(..;::~.~~~j:r
.... . ...... ..
. . . . . .
.. ..
. . . . ..
... ..
:I!(~;4' mt~r,
0.3
0.067
0.04
0.001
0.0002
0.0003
0.2
0.0004
0.002
0.4
0.03
0.005
1.4
0.044
0.07
'.."""';,,,... .""'. ","""'/."""
',' '.:'<,,':' ',"':, "'"
. .. .
, HazarJl'lndeX .
, 1L:: (CDM)h/:,
-
e 08
002
(j 0003
C 0003
0.0003
0.04
0.0003
(' J05
0.02
0.002
-
0.3
0.0078
0.003
-------
TABLE 10 (ConI.)
COMPARISON OF CII2M lULL AND CDM ESTIMATES OF IIAZARD INDICES
FOR INGFSfION OF SURFACE WATER4
RifFS Zone I, OU 2
Robins AFB, Georgia
,.". ..
"':,':',:',:'::" .'. ".':'.:::'::"..:
':''':'.:...'
::, . ..,.....:.,,::.
Maximum
:. 'CclnCefttration '...
.:' (ClUMJIIt~)..
!: :: :(pgncg)' ::: .'
4
..
. ...
...\MlixlmiJln:=,::,:i, .
POWngradlent .
CoritentratioD
':.(CDM)':: ..,
(pglkg)
ND
23.63
4.0
'."
. Chemical.
4-Methyl-2-pentanone
Nickel
Pyrene
':. ',:::..U .,".: . R~r.eren. ce
::" .:'.;.:. '. 'J>Ose 'OtJP)
. . (iiiglkft/ciay)
0.05-
0.02
0.03
HEAST
IRIS
5.1
239
1.04
52.45
Source'-
IRIS
..
97.6
12
Selenium
Silver
0.005
0.005
IRIS
IRIS
5
203
5,070
Toluene
0.3
0.009
0.2
1,242.4
30
63.32
Vanadium
Zinc
IRIS
HEAST
. Exposure ASStDnptions
E.poswe Setting
E.posure Individual
Water Intake (liters/day)
Body Weight (kilograms)
~ Sources of'RIDs:
IRIS - Integrated Risk Information System USEPA (1992a).
SPHEM - Superfund Public Health Evaluation Manual USEPA (1986b).
HEAST - Healtb Efft:Cts Assessment Summary Tables - USEPA (l992b).
C Cyanide value basOO on free cyanide.
d Nickel value based OD nickel-soluble salts.
. RID currently withdrawn pending review, (USEPA 1992a).
Trespass
Child
0.05
35
'~I IIIIIIIINSITAIII.£SI).). T/ll.
01f21m cnIh
,.).,:-:. .'.':'.
'."'" "':,:,:,,,'C
: :,' Hazar" Indez
::. (ClaM rou)
0.0001
0.001
0.006
0.0018
0.06
0.00002
0.03
0.04
'.
. .
..
pazard Index
::.:" "(CO' M):.'
~ '{ ::. . ':. ';
-
0.002
0.002
0.0003
0.012
0.0001
0.008
0.01
-------
~TABLE 11
COMPARISON OF CIUM lULL AND CDM ESTIMATES OF CARCINOGENIC RISKS
FOR INGESTION OF SURFACE WATER"
RifFS Zone I, OU 2
Robins AFB, Georgia
:/)}.,' ",'."" .,:,',::".'.::. "";"';";"""'"
{;:'''''';;::-'.;,.;'''''',''; ;":"';"", :':,::,}';i
,;, ;." .,;..,,' ";',:,;;;,.'
:-'::\"".,.,.;" ..' >'
:': ".:':,";' '.
CJianlcal .' ,;
, , . ......... . .
:':}::::::;::.:'::::::::::':::r~::~:::::::::;:::::::
. ,'" . ....',....".........
""""..'................. .
.. . . . .. ... . . . . . . . .
.... .. ......,.,..
. .... ..... ".' .
.. .. . .....0. .
,',.,',".'.','
....... ........
'".,,'.,',"
. """
... .. .. .. ..
.. . .....
USEpA,c~"'fJaic.
" Cai'dftOien: ro_"ador
Classificadon f (kg~.yfmg)' SoiJrce'
Arsenic A
Benzene A
Bromodicbloromethaoo B2
Chloroform B2
T richloroetbene B2
. Exposure Assmnptions
Exposure Setting
Daily Water Intake (lilers/day)
Body Weighl (kilograms)
Number of days/week exposed
Number weeks/year exposed
Number of yean exposed
Lifetime Average Water Intake
I 75
0.029
HEAST
IRIS
.... ","' .. "', ~.,'
. .. "' .. '" ... . ..
. ............ ... . . . . . . . . .
.','..",',',".',.',",',",',.',','.',',."',','.,",",',',
...,."".......,."""""".,.
,,"""""',"'..,"'"''''''''
, ......, ..........,'......' ,.
""".'.,"','"',.".',,','.",'.',,,',',',',',',',',,'.'"
,.... ,..,........,..,......,...
" .,. ., ,.,..."..,..."...,
. ........., ...... . ..,
: MaiidiUril':: '
:tOri&intt8t1on .
'...' ~fWc:mH"
~:...~
0.13
0.0061
HEAST
IRIS
12 14.41 4B-01 5 x 10'1
5 - 3E-09 -
3 5 7B-09 1 x 10"
II 26 1 E-09 2 x 10"
7 52 I B-09 7 x I~
~ Sources of Cancer Potency Factors:
IRIS - Integrated Risk Information System USEPA (1992a).
SPHEM - Superfund Public Health Evaluation Manual USEPA (1986b).
HBAST - Health Effects Assessment Summary Tables - USEPA (l992b).
. Carcinogenic Potency Factor currently withdrawn pending review (USEPA 19928).
49t\aOBINS\TABLI!S\U.TBL
mml92 ..
0.011°
IRIS
Trespass
0.05
35
2
16
10
0.00002
(litenlkg body wt.fday)
-------
6.2 ECOLOGICAL RISK ASSESSMENT
This Ecological Risk Assessment (ERA) used several different approaches for evaluating
potential risk to ecological receptors from contaminants attributable to Landfill No.4 and the
adjacent sludge lagoon. Media-specific concentrations of chemicals were measured from
samples collected at appropriate reference, upgradient, and down gradient locations. In
addition, ecological and toxicological approaches were used to assess site-specific differences
in potential impacts from chemical contamination. These ecological and toxicological
approaches included macroinvertebrate sampling, a USEPA Rapid Bioassay Protocol (RBP)
III evaluation, surface water and sediment toxicity tests, fish and macrophyte tissue analyses,
a Wetland Evaluation Technique (WET) assessment, and a breeding bird survey.
6.2.1 AQUA TIC ECOSYSTEM
Table 12 summarizes estimated surface water and sediment exposure point concentrations for
aquatic receptors along with Ambient Water Quality Criteria (A WQc), sediment t~xicity
values, and no observed adverse effect level (NOAEL) or lowest observed adverse effect
level (LOAEL) dietary concentrations for higher trophic level species that may consume fish.
For chemicals not considered to be aquatic sediment COCs, mean and maximum aquatic
sediment values are presented.
A review of Table 12 indicates that the greatest potential risk for aquatic organisms is from
direct contact with metals via sediment and surface water. In particular, cadmium, lead,
mercury, silver, and zinc exceed both surface water criteria and sediment toxicity values. In
addition, mercury and zinc are ubiquitous. occurring in nearly every aquatic sediment
sample, while cadmium, lead, and silver occur primarily in pond sediments. For surface
water, higher concentrations, including all exceedances of A WQC, consistently occur in the
wetland area approximately 800 ft. northeast of the landfill and southwest of the ponds in the
study area. No exceedances of A WQC were detected in any permanent water body in the
study area. For aquatic sediment and wetland soil, the distribution of metals- follows a
pattern similar to surface water. Higher concentrations, including most exceedances of
54
-------
1- ---------------- -
TABLE U
AQUATIC .:COSVSTEM RISK CIIARACTERIZATION SUMMAR V
RifFS ZONE I, OU)
Robim AFB, Georgi.
Potead8lly rot""'" RetertDC~
Surface A WQC" . Aquatic Sedillleat Cootambuted CilatamJuted DIetary
Water- Acut.x:brooic Sedilllear NOAEL Aquatic nUts' .....,. COIEftItntioo'
C-.nicat (milL) (mllLl (.qlq) (mll'kl) (maJ1c)' (m~1 (m8llll1
ORGANICS
Benzo(a)pyrene Ne' NA'/NA 1.16 0.4' NO' NO -
Bis(2~lhylhcxYIJ phthalale 0.089 0.94010.003' 16(6.2); 33' I 0.91 IS (WEL, 8I8r1ing)
4,4'DDD NC NAiNA 0.048 NA ND 0.197 2 (LOAEL, black duck)
4,4'ODE NC 1.051NA 0.049 NA NO 0.270 2 (LOAEL, black duck)
Dieldrin 0.00008 0.002510.0000019 ND NA ND 0.113 0.1610.5 (NOAEL, nil
barn uwl
INORGANICS
Cadmium 0.023 0.039/0.011 20(14); 5.1' I.J 1.1 7.1 (NOAEL, sheep)
Chromium 0.067 1.70/0.210(110 220(50)' 260 ND ND -
0.01610.011 (IV) (Iolal CrY
Lead 0.18 82/0.0032 360(85); 3SJ 2.0 1.09 50 (LOAEL, American
ltellrel)
Mercury 0.0005 0.0024/0.000012 1.19 0.41' 0.010 0.460 0.55 (NOAEL, mallard
duck)
Silver 0.044 0.0041/0.000/2 61(36)' I.Oi ND NO
-
Zinc 0.54 0.047/NA 156 12() 99.4 21.8 100 (NOAEL, nl)
. EIIimated media concenlRlion. are laken from Table 6~ (IUrface walcr) and Table 6-7 (aqualic eedimenl) of OU2 Rt.
" Ambient Water Qualily Crileria for proseclion of aqualic life. Sourc~: USEPA 1986. Qualily Crileria for Waler, Offiee of Regulalionsand Slandarda, EPAl44015-16-00I.
. Source: ~aahin&ton Slale Adminillnlive Code 1991. D.epartment of Ecology, Chapler 173-204 Sedimenl Management Slandard.; Adopled March 21, 1991, effective April 27, 1992. Till~ 173.
, Eatimaled aqualic plant and prey concentnlionsare based on data collecled althe followin.localion.: PI, P2, PJ, 57,51, and 513. See Sect. 6.3.3 of 002 RI for diacullion ret.rding
aclected value..
. Valuutaken fmm T,,,,,, . II..! ',IU 11.1.
, NC-Not Cal~lda"LI. :. I. l uC for indicated media.
I NA-NOI Available.
. ND-Not Detected.
I Not a acdiment COCo For reference, maximum dowlllndient value provided with mean value in parentheac..
J Source: Nalional Oceanic and Atn»lpheric Adminiltntion 1990. The Potential for BioI.al Elfccta of Sodimcnl-Sorbcd Conlamina... Telled in the National SlaNa and Trend. Progf8ff1,
NOAA Technical Memol'llndum NOS OMA 52.
-------
sediment toxicity values. consistently occur .in the wetland area nonheast of the landfill and
southwest of the ponds. In addition, the pOnds appear to be accumulating metals.
The organics appear to present a minimal risk in surface water and sediment.
Benzo(a)pyrene is not a cac for surface water and the estimated aquatic sediment exposure
point concentration is close to the sediment toxicity value. The estimated surface water
concentration for bis(2-ethylhexyl)phthalate exceeds the chronic A WQC by an order of
magnitude, but the maximum sediment concentration is half the toxicity value. Surface
water and s~iment concentrations for the pesticides are quite low and are not expected to
present a significant risk via direct ingestion or contact.
A comparison of the contaminated prey (fish) data and the NOAEL and LOAEL dietary
concentrations for sensitive piscivorous predators indicates that, with the exceptiOn of
mercury, none of the cacs appear to be accumulating enough to cause a direct risk.
However, mercury bioaccumulates rapidly in aquatic environments.
6.2.2 TERRESTRIAL ECOSYSTEM
Table 13 presents estimated exposure point concentrations for wetland soil and potentially
contaminated vegetation and prey along with LOAEL or NOAEL dietary concentrations for
species at high trophic levels. A review of the estimated exposure point concentrations for
wetland soil indicates that direct ingestion of wetland soil may pose a risk due to the
concentration of DDT and dieldrin. Although wetland soil would not be ingested at the same
rate as food, soil ingestion may be significant for burrowing animals or animals such as the
wild boar, which spends a considerable amount of time digging in the soil. Both DDT and
dieldrin appear to be ubiquitous in wetland soil, occurring in most wetland soil samples.
Consumption of contaminated prey may pose a risk due to potential levels of cadmium and
mercury in prey species. However, the risks associated with cadmium are expected to be
much less significant than those associated with mercury. Mercury has a high potential to
bioaccumulate and to biomagnify, and the biomagnification of mercury can result in risks to
upper trophic level predators.
-------
TABLE 13
TERRESTRIAL ECOSVSTEM RISK CHARACTERIZATION SUMMARV
RIIFS ZONE 1, OUl
Robins AFB, Georgia
Potentially Contaminated Potentially. Reference Dietary
Chemicill Wetland Soilo Vegetalion" Contaminated Preyr Concenlration4
(mg/kg) (mg/kg) (mg/kg) (mg/kg)
ORGANICS
B~nw(a)pYft:ne 0.90 NO NC 30 (NOAH., mouse)
Bis(2-elhylheJl yl)phlhalale' NO' 9.5 9.5 25 (LOEL. starling)
4,4'000 0.87 NO NC NA
4,4'DDE 0.28 NO NC 2 (LOAEL, hlack duck)
4,4'OOT 7.36 NO NC 0.3 (NOAEL, 'phea!;8nl)
Dieldrin 0.53 ND NC 0.16/0.5 (NOAEL.
ratlbam owl)
INORGANICS
Arsenic 24.77 NO NC 31 (LOAEL, ral)
Cadmiumd NDe 1.5 6.0 7. I (NOAEL, sheep)
Mercury 0.34 0.04 0.44 0.5:. (NOAEL, mallard)
Sdenium 9.69 ND NC 5 I LOAEL, chicken)
Zinc 84.79 27.7 8.3 100 (NOAEL, ral)
ND = Not Detected
NC = Not Calculated
. These values are potential exposure point concentrations shown on Table 6-8 of the OU2 RI.
" Represents the maximum concentration detected in vegetation from co-located sample stations (Table 6- 10 or OU2 RI).
. Calculation of these values is discussed in Section 6.3.4 of OU2 RI.
d Values taken from Table 6-10 of OU2 RI.
o Although this chemical was not selected as a soil and sediment COC, it is included bere because it was detected in terrestrial vegetation.
r Chenucal was not detected in the soil samples tbat were co-located witb vegetation samples.
-------
. .. '.' .. ....'. .',. .
. .... ..... -. . .
6.2.3 ERA CONCLUSIONS
The ERA concluded that for ecological receptors, the risks are 10w,fJr contained to relatively
---
small areas (Le., the ponds and drainage ditches), and indicated that several external factors
may be affecting the wetlands down gradient of Zone 1. These factors include other potential
sources of contamination and various AFB management activities that influence the water
regime in the wetlands. The ERA also concluded that the wetlands associated with OU2
provide an important habitat for a variety of wetlands plants and animal species and because
the ecological risks are low or are confined to relatively small areas, protection of the
wetlands should be given a high priority when evaluating remedial alternatives.
The selected interim remedy (Alternative 2, Limited Action) includes the following:
. Institutional controls (Le., fence construction to restrict access, posting signs) for
future site access and water-use restrictions.
. Comprehensive monitoring for a minimum of one year not to exceed three years in
suppon of physicalfchemical and ecologica1Jbiological monitoring plans to be
developed to monitor stabilization of the site following redirection of runoff discharge
around the landfill and diversion of industrial wastewater discharge from upgradient
of the landfill and wetlands, 50 that a flnal remedial action can be developed from the
current and expected future conditions.
. Development of a contingency plan that describes containment measures to be
implemented in the event that predetermined "trigger values" are exceeded.
-------
7.0 DESCRIPTIONS OF ALTERNATIVES
7he foHowing is a summaiy of the alternatives evaluated for the wetlands associ:::GJ ~ '~h
Zone I, OU2. Specific details were developed to allow order-or-magnitude cost esu~:' . '()ns.
7.1
ALTERNATIVE 1 - NO ACTION
No monitoring, institutional controls, remedial or treatment actions will be implemented.
7.2
ALTERNATIVE 2 - LIMITED ACTION
The Limited Action alternative consists of institutional controls (Le., fence construction to
restrict access, posting signs) for future site access and water use restrictions, monitoring for
a defined time frame in suppon of physical/chemical and ecological/biological monitoring
plans to be developed and implemented as the remedial design for the Action, and
development of a contingency plan that describes containment measures to be implemented in
the event that predetermined "trigger values" set in the monitoring plans are exceeded. The
monitoring plans will define analy~is (contaminants of concern, physical parameters, etc.)
'media to be sampled (soil, sediment, water, fish, vegetation, etc.), sampling locations and
schedule, and hydrological input and output points in the wetlands to be monitored for flow
elevation arid chemistry.
7.3
ALTERNATIVE 3 - SURFACE WATER COLLECTION, TREATMENT, AND
RECIRCULA TION
Alternative 3 includes collection of surface water, treatment of the water for organic and
inorganic contaminants of concern, recirculation of the treated water back in to the wetlands,
and monitoring as described under the limited action alternative.
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7.4
ALTERNATIVE 4 - DREDGING/DEWATERING Al"'D SOLIDIFICATION OF
AQUATIC SEDIMENTS, WIm ONSITE DISPOSAL
Alternative 4 would require dredging/dewatering and solidification of approximately 171,295
cubic yards of aquatic sediment, onsite disposal, and monitoring as described under the
limited action alternative. Dewatered solids would be stockpiled and treatment through
solidification/fixation. Final disposal would be in a Resource Conservation and Recovery
Act (RCRA) cell constructed on base in a designated area for this purpose.
7.5
ALTERNATIVE 5 - DREDGINGIDEW A TERING AND OFFSlTE DISPOSAL
OF AQUATIC SEDIl\1ENTS.
Alternative 5 would require dredging/dewatering of approximately 171,295 cubic yards of
aquatic sediments and loading and transporting it to an offsite RCRA-permitted (S~btit1e C)
landfill.
A remedial design for any of the monitoring or treatment alternatives may require additional
field investigation to further delineate the area to be addressed by remediation, and/or define
and characterize source areas not included under au 1.
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8.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVFS
The wetlands associated with OU2 are currently providing important habitat for numerous
species. Results for the ecological risk assessment show that vIable and diverse populations
of aquatic and terrestrial wildlife are currently using the habitats in Zone 1.
It should be noted that designing and implementing an action while the wetlands are changing
(due to redirection of runoff and diver:sion of industrial waste discharge) may not be effective
or efficient. . Any design or implementation can be better performed when the wetlands reach
a steady state hydrology or water balance.
8.1
OVERALL PROTECTION OF HUMAN HEALTII AND THE ENVIRONMENT
Alternative I would not rapidly eliminate exposure pathways. However, over time, natural
attenuation may reduce the concentrations of contaminants to below remediation levels,
especially once the sources of contamination are controlled. Alternative 2 is similar to
Alternative 1 except that institutional controls associated with Alternative 2 would help
minimize potential direct exposure to hazardous substances. In addition, the monitoring
program associated with Alternative 2 would monitor stabilization of the site following
t
redirection of runoff discharge and diversion of industrial wastewater discharge from
upgradient of the landf1l1 and wetlands so that a final Remedial Action can be developed from
. .
the current and expected future conditions. Alternative 3 would remove COCs from the
drainage ditch, ponds, and surface water at the collection points, but other surface water
discharges to Horse Creek would not be controlled. Alternative 4 would remove
contaminated sediment affecting aquatic organisms, but would also eliminate all existing
benthic organisms and the habitat which are not easily replaced. In addition, dredging would
resuspend contaminated sediments which may cause contaminants to enter the ecological food
chain. Alternative 5 provides an overall protectiveness similar to that provided by
fil
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Alternative 4, but would also ehminate risks associated with the fixation process and release
of metals from fixed solids (Alternative 4).- Finally, an effective implementation of
Alternatives 3, 4 or 5 may not be possible until after the wetlands reach a steady state
hydrology or water balance.
8.2
COMPLIANCE WITH ARARs
Chemica1-, location-, and action-specific ARARs which potentially apply to OU2 are
presented in the OU2 FS. The Wetlands Management Executive Order, Executive Order
11990, Protection of Wetlands (40 CFR 6.302) is also applicable. However, pursuant to
CERCLA 121(d)(4) and NCP 300.430(f)(1)(ii)(C)(1), compliance with ARARs is waived
because the selected action is an interim remedy; that is, the selected remedial action is only
part of a total remedial action that will attain ARARs.
8.3
LONG- TERM EFFECTIVENESS AND PERMANENCE
Because the interim action is not designed or expected to be final, and is in place until a final
remedial action can be developed from the current and expected future conditions, a
comparison of alternatives in terms of long-term effectiveness and permanence is not
relevant.
8.4
REDUCTION OF MOBILITY TOXICITY OR VOLUME (MIT/V) THROUGH
TREA ThfENT
Alternative 1 and 2 would not decrease M/T/V, however, toxicity and volume may be
reduced through natural attenuation if contaminant concentrations decrease over time.
Alternative 3 would provide a net decrease in offsite migration of contaminants.
Alternative 4 eliminates mobility and toxicity of contamin~ts through treatment, however,
since solidification/stabilization is required, volume may increase. Alternative 5 eliminates
mobility and toxicity of contaminants through offsite disposal.
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8.S
SHORT-TERM EFFECTIVENESS
Alternatives I and 2 pose minimal shon-term risks to onsite workers. Alternative 3
construction activities may disturb sediments and results in the release of additional
contaminants to Horse Creek.
The limiting factor in processing time for dredging activities and operations associated with
Alternative 4 and 5 will be dewatering. Alternatives 3, 4, and 5 would require
approximately two years for implementation. Technical considerations for Alternative 4
include control of sediment spreading during dredging, treatability testing and location and
design of a RCRA cell. Technical considerations for Alternative 5 include control of
sediment spreading during dredging, obtaining permits and manifests for offsite disposal and
facility accepting waste.
8.6
IMPLEMENT ABILITY
Alternatives I and 2 could be implemented immediately. Development and implementation
of a comprehensive monitoring plan and the use of institutional controls, would be required
for Alternative 2. Alternative 2 will allow for monitoring the stabilization of the site
following redirection of runoff discharge and diversion of industrial wastewater discharge so
that a final remedial action can be developed from the current and expected future conditions.
Alternative 3 could be implemented in approximately two years and would involve treatment
system design, pilot-scale studies, disposal of biological sludge and used carbon. For
Alternatives 4 and 5, the limiting factor in processing time would be dewatering.
Alternatives 3, 4, and 5 would require approximately two years for implementation.
Technical considerations for Alternative 4 include control of sediment spreading during
dredging, treatability testing and location and design of a RCRA cell. Technical
considerations for Alternative 5 include control of sediment spreading during dredging,
obtaining permits and manifests for offsite disposal and facility accepting waste. As an
interim remedy, Alternatives 3, 4 or 5 are less feasible than Alternative 2 because of the time
required to implement them and because implementation may not be effective or efficient
while the water balance in the wetlands is changing.
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8.7
COST
The cost for Alternative 2 is estimated to be significantly less than Alternative 3, 4, and 5
(See Table 14). It should be noted that estimated costs for Alternatives 4 and 5 are based on
remediation of an areas exceeding National Oceanic and Atmospheric Administration
(NOAA) screening values. Costs could potentially be reduced pending further delineation of
the area to be addressed by remediation during the remedial design.
8.8
AGENCY ACCEPTANCE
The U.S. EPA and GEPD have accepted Alternative 2 as an interim remedy (contingent
upon public acceptance).
8.9
COMMUNITY ACCEPTANCE
Based on comments made by citizens at the public meeting held on September 16, 1993, it is
believed that the community is supportive of the selected interim remedy for OU2
(institutional controls and monitoring). One citizen did recommend that Alternative 3
(surface water collection, treatment, and recirculation) be selected for OU2 on the basis that
even through sediment contamination would not be changed significantly, treating the water
and returning it will not do more damage to the wetlands.
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Table 14: Wetlands Alternatives
Robins AFB, Georgia
Estimated
Capital
Cost
Estimated
Annual
O&M Cost
Estimated Total
Present Worth
Cost
1. No Action $ 0 $ 0 $ °
2. Limited Action:
Institutional Controls
and Monitoring 225,000 67,550 889,011
3. Surface water collection
treatment, and recirculation 1,818,375 672,933 7,350,448
4. Dredging/dewatering
and solidification of aquatic
sediments with on site
disposal 23,382,316 184,081 24,862,852
5. Dredging/dewatering and
offsite disposal of aquatic
sediments 54,223,219 43,900 54,413)283
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9.0 SELECTED REMEDY
Based upon consideration of the requirements of CERCLA, the detailed analysis of the
alternatives, and public comments, Robins AFB in consultation with U.S. EPA and GEPD
has determined that the most appropriate interim remedy for the wetlands associated with
OU2 is Alternative 2.
The interim remedy for OU2 Impact on Wetlands includes:
. Institutional controls (i.e., fence construction to restrict access, posting signs) for
future site access and water use restrictions.
,
. Comprehensive monitoring for a minimum of one year not to exceed three years in
support of physical/chemical and ecological/biological monitoring plans to ~e
developed to monitor stabilization of the site following redirection of runoff discharge
around the landfill and diversion of industrial wastewater discharge from upgradient
of the landfill and wetlands so that a final remedial action can be developed from the
current and expected future conditions. I
. Development of a contingency plan that describes containment measures to be
implemented in the event that predetermined "trigger values" set in the monitoring
plan are exceeded.
A remedial design for the monitoring alternative may require additional field investiga~on!O' ...
further delineate the area to be addressed by remediation, and/or define and characterize,,':t;:ft~:
,:,',',~;\r,i",'"
source areas not included under OU 1..,
The estimated cost of the selected interim remedy is presented in Table 15.
Table 15: Selected Interim Remedy Cost Estimate
Estimated Capital Cost:
Estimated Annual O&M Cost:
Estimated Total Present Worth Cost:
$225,000
$ 67,550
$889,011
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9.1
REMEDIA TION GOALS
The specific objectives of the selected interim remedy are to:
1.
Protect existing habitat.
2.
Minimize the potential direct and indirect exposure of the public
to hazardous substances.
3.
Monitor the stabilization of the site following redirection of runoff discharge
around the landfill and diversion of industrial wastewater discharge from
uJ'gradient of the landfill and wetlands, so that a final remedial action can be
developed from the current and expected future conditions.
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10.0 STATUTORY DETERMINATIONS
~
Under its legal authorities, the EPA's primary responsibility at Superfund sites is to
undertake remedial actions that achieve adequate protection of human health and the
environment. In addition, Section 121 of CERCLA establishes several other statutory
requirements and preferences. These specify that when complete, the selected remedial
action for this site must comply with applicable or relevant and appropriate environmental
standards established under Federal and State environmental laws unless a statutory waiver is
justified. The selected remedy also must be cost-effective and utilize permanent solutions
and alternative treatment technologies or resource recovery technologies to the maximum
extent practicable. Finally, the statute includes a preference for remedies that e"mploy
treatments that permanently and significantly reduce the volume, toxicity, or mobility of
hazardous wastes as their principal element. The following sections discuss how the selected
I
remedy meets these statutory requirements.
As the lead Agency, the Air Force is required to comply with CERCLA 120, (Executive
Order 12580 of January 23, 1987), and EPA is to determine that they are complying with
CERCLA 120.
10.1
PROTECTION OF HUMAN HEALm ~'D mE ENVIRONMENT
The selected interim remedy protects human health and the environment through; 1) the use
of institutional controls (Le., fence construction, posting signs) for future site access and
water use restrictions and 2) the development and implementation of a comprehensive
monitoring program to monitor stabilization of the site following redirection of runoff
discharge and diversion of industrial wastewater discharge, so that a final remedial action can
be developed from the current and expected future conditions. Further protection of human
health and the environment is provided through the development of a contingency plan that
68
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describes containment measures to be implemented in the event that predetermined "trigger
values" set in the monitoring plan are exceeded.
This interim action does not employ a remedy that pennanently and significantly redu.~'es the
toxicity, mobility, or volume of the contaminants because the interim action is not d{:signed
or expected to be final. More specifically, designing and implementing a permanent action
while the wetlands are changing may not be effective or efficient. Any pennanent design or
implementation can be better perfonned when the wetlands reach a steady state hydrology or
water balance.
10.2
COMPLIANCE WITH APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS
ARARs for this limited scope action (described in the OU2 FS), and including the Wetlands
Management Executive Order, Executive Order 11990, Protection of Wetlands
(40 CFR 6.302) have been waived pursuant to CERCLA 121(d)4 and NCP .
300.430(f)(l)(ii)(C)(l), because the selected interim action is only part of a total remedial
action that will attain ARARs.
t
10~3
COST EFFECTIVENESS
.
The selected interim remedy for the wetlands associated with OU2 has been detennined to
provide overall effectiveness proportional to its cost, and provides a reasonable value for the
money. The total present worth cost is $889,011. The cost/effectiveness relationships for
Alternatives 3, 4 and 5 do not compare to Alternative 2, because as indicated prevIously,
designing and implementing an action while the wetlands are changing may not be effective
or efficient.
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10.4 UTll..IZATION OF PE~\tAA'ENT.SOLUTIONS AND ALTER'\'ATIVE
TREA TMENT TECHNOWGIES (OR RESOURCE RECOVERY
TECHNOWGIES) TO THE l\-tAXThIUM EXTE~T PRACTICABLE
. The selected action is interim and is not designed or expected to be final. The selected
interim remedy represents the best balance of tradeoffs among alternatives with respect to
pertinent criteria, given the limited scope of action.
10.5
PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
The statutory preference for remedies that employ treatment as a principal element will be
addressed in the final decision document for OU2.
10.6
DOCUMENTATION OF SIGNIFICANT CHANGES
No significant changes from the proposed plan were made.
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COMMUNITY RELATIONS
RESPONSIVENESS SUMMARY
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COMl\1UNITY RELATIONS RESPONSIVENESS Sm-~IARY
1.0 OVERVIEW
Robins AFB along with the U.S. EPA and GEPD held a public meeting on September 16,
1993 at the Warner Robins City Hall to discuss the results of the RIfFS for OU2, present the
proposed interim plan for OU2, and solicit comments and questions from the public. All of
the comments received during the public comment period (August 10, 1993 to September 29,
1993) were received during the public meeting, however, several were not directly related to
OU2.
2.0 BACKGROUND ON COMMUNITY INVOLVEMENT
An active community relations program providing information and soliciting input has been
conducted by Robins AFB for Zone 1. Interviews of citizens on base and in Warner Robin~
were conducted in the summer of 1990 to identify community concerns. No significant
concerns that required focused response were identified. Regular informational project
updates have been provided to the public through television programs, the Robins AFB
newspaper, The Rev-Up, the Warner Robins Daily Sun, and the Macon Telegraph. Robins
Report, a weekly 15-minute television program produced by the Office" of Public Affairs has
provided routine progress updates. This program is aired Sunday mornings on WMAZ- TV
in Macon, Georgia. It also is telecast on Cox Cable and Watson Communications Cable,
which are available to Robins AFB and Warner Robins residents. Weekly informational
anicles have appeared in The Rev-Up newspaper. In addition, NPL site and IRP fact sheets
have been prepared and made available in the Environmental Information Repository, located
in the Nola Brantley Memorial Library in Warner Robins.
3.0 SUMMARY OF PUBLIC COMMENT AND AGENCY RESPONSE
Comments and questions raised during the public meeting held on September 16, 1993 are
summarized below. No other comments or questions were received during tl)e public
comment period.
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I . A concerned citizen asked why a cost associated with an alternative (Alternative 2 -
Limited Action) was listed as 0 dollars on one slide and 520,000 dollars on a second
slide. She did not understand the difference between the two.
Robins AFB Response: When the proposed plan was originally submitted, the 520,000
dollar cost was omitted. The second slide was included to clarify that there is a cost
associated with the alternative. It should be noted that cost figures are not presented to
present an exact cost estimate of each alternative, but rather to serve as a comparison
between one alternative to another. Because the omission was made in each of the
alternatives, a consistent comparison was made.
2. A concerned citizen asked if Alternative 2 (Limited Action) has been selected for this
Operable Unit (OU2).
Robins AFB Response: The proposed plan (Alternative 2) is the bench program. The
reason Alternative 2 was selected was to allow further characterization of the site because
significant changes in water flow had occurred. Rather than making measurements without
knowing what the water balance is going to be, Alternative 2 allows us to study the effect of
potentially significant changes to the water balance.
3. The same concerned citizen asked for an update on the status of Operable Unit 1 because
she understood that the alternative selected for the stabilization of contamination was not
working and wanted to know what would happen if the solidification process did not
work.
Robins AFB Response: Solidification is the alternative for stabilization. A technology
,
evaluation for solidification of the sludges was solely a demonstration. That particular
demonstration was to demonstrate a panicular technology. It was not meant to be the final
remedy. That panicular technology did not work, but it is not the only avaiiable technology.
Since then, we have contracted five contractors to evaluate their technologies and narrowed
the list to three contractors. We have evaluated their proposals, studied bench- and pilot-
scale studies for the past year and will soon announce which of the contractors will perform
the work. All of the studies from the three remaining contractors indicate that their
technologies worked in their bench- and pilot- scale studies.
~... ~ ~
4. The same concerned citizen commented that her group's research indicated that almost
all of the solidification processes were experimental to an extent in that they did not
represent long-term solutions, and requested that another alternative be chosen for OUI.
The commentor also requested that alterative number 3 (surface water collection,
treatment, and recirculation) be chosen for OU2, because public hearings at the base
indicate there are significant amounts of pollution coming from all sorts of different
areas, and it would not cause any damage to start treating the water now and return it to
the swamp.' Finally, the commentor expressed concern that the interim plan does not
address bioaccumulation. She indicated that DDT is one of the contaminants coming
out of the waste dump and stated that a link exists between bald eagles and"DDT, as well
as breast cancer in women and DDT, and that arsenic and lead never disappear in terms
];,
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of biological contamination. She expressed concern over people eating fish when
pollutants bioaccumulate in the Ocmulgee River and that pollution from the base as well
as the pipeline 13 putting aJl CYC:u t;lc:aLCl ,)lieUn on the river dI1d its ecosystems.
Robins AFB Response: Your concern is appreciated. All appropriate alternatives are being
studied.
EPA Response: The wetland area is a very diverse bio-environment. The plumes from the
landftll into the wetlands are fairly well-defined, and because they are fairly well-defined and
the migration rate known, we would be looking at some other. kind of action if nothing else
were occurring. However, approximately 70% of the inflow is not going into the wetlands
anymore, so the environment is changing. The concern with conducting a remedial action at
this point, is that more damage than good will be done because we don't know enough in
terms of the changing water level and its effect on the wetlands.
5. A concerned citizen commented on the previous commentor's statements. He indicated
that the speaker made some rather sweeping assertions that she should be able to
docu",~nt because the press was present and they would pick up on her assertions as
being true and certain, which would be a disservice to the effort being conducted. The
commentor stated that the previous commentor's assertions should be recorded as her
belief as to what is happening and not as a matter of fact. The previous commentor
responded that she did not believe she had made any assertions and would stand behind
her convictions.
Robins AFB Response: No response was made.
6. A concerned citizen asked for a review of the status of au 1 including cost and time
frame for completion. The commentor stated his understanding of the situation which
was that the Air Force would be proceeding with the remediation of the sludge and
correcting the problem from the landfill. The concern then is what the correction
process does to water flow in the wetlands, so the plan is to select an alternative which
provi~es for intensive monitoring. The commentor also stated his understanding that the
process has been in progress for about ten years and an agreement between EPA,
Georgia Department of Resources and the Air Force has been made to try and speed up
the process.
Robins AFB Response: The alternative selected for OU2 is an Interim Plan. It is not the
final action. The final action will be determined after additional monitoring results are
obtained and evaluated. The ultimate completion of the cycle (OUI source control) is
projected for 1998. Solidification studies will be completed and evaluated and contractual
proceedings will then be initiated. A construction contract could be let within the first
quarter of 1997. The lagoon will be. solidified first and the material placed on the landfill.
A new cap will then be placed on the landfill. The cost will probably be in excess of over
100 million dollars for the whole cycle (source control)
3
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7. The same concerned citizen asked if the Air Force was in a position to adjust or change
the remedial action if something was not working.
Robins AFB Response: The Air Force in conjunction with the regulatory authority is
required to review the remediation effort every five years and make sure that any remedial
actions taken are effective. This process is required by the regulatory authority.
8. A concerned citizen expressed concern about trichloroethylene and methylene chloride
levels in the lagoon, a chemical to treat fire ants in the swamp area, and potential toxic
materials buried in the swamps and wetlands and their effect on the aquifer. He spoke
of lead levels where a pipeline was constructed on a Mr. Robinson's property, and stated
that he would like to bring three individuals who could point out areas on-site where the
hazards he discussed exist.
Robins AFB Response: The comment period is open through September 29. Written
comments may be submitted to the address provided on the handout received at the door.
For more information, contact the public affairs office at Robins AFB.
4
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