EPA Superfund
Record of Decision:
PB95-964029
EPA/ROD/R04-95/244
February 1996
Ciba-Geigy Corporation
Superfund Site, Mclntosh, AL
7/25/1995
-------
RECORD OF DECISION
SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
CIBA-GEIGY CORPORATION SUPERFUND SITE
OPERABLE UNIT #3 McINTOSH FACILITY
MdNTOSH, WASHINGTON COUNTY, ALABAMA
PREPARED BY
U. S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GEORGIA
-------
TABLE OF CONTENTS
1.0 Site Location and Description 1
2 .0 Site History and Enforcement Activities 4
3.0 Highlights of Community Participation 10
4 .0 Scope and Role of Operable Units 10
5.0 Summary of Site Characteristics 11
5.1 Physiography, Climate 11
5.3 Soils 13
5.3 Surface Water Hydrology 13
5.4 Biota Observations 14
6 . 0 Summary of Site Risk 15
6 .1 Contaminants of Concern 16
6 .2 Human Health Risk 27
6 .3 Environmental Risk 28
6.3.1 Sampling Methodology 32
6.3.2 Results of Analysis 33
6.3.3 Summary/Discussion 48
6 .4 Cleanup Goals 52
7 .0 Description of Alternatives 53
7 .1 Alternative No. 1 - 53
7 .2 Alternative No. 2 - 53
7 .3 Alternative No. 3 - 54
8.0 Summary of the Comparative Analysis of Alternatives 56
8.1 Overall Protection of Human Health and the Environment....57
8.2 Compliance With ARARs 57
8 .3 Long-Term Effectiveness 58
8.4 Reduction of Toxicity, Mobility or Volume By Treatment....58
8.5 Short-Term Effectiveness 58
8.6 Implementability 59
8 . 7 Cost 59
8.8 State Acceptance 59
8 .9 Community Acceptance 59
9 .0 Summary of Selected Remedy 59
10. 0 Statutory Determination 62
10.1 Protective of Human Health and the Environment 62
10.2 Attainment of ARARs , 62
10.3 Cost Effectiveness 64
10.4 Utilization of Permanent Solutions 64
10.5 Preference for Treatment as a Principal Element 64
11.0 Documentation of Significant Changes 65
-------
Appendix A - Responsiveness Summary 67
Appendix B - Concurrence Letters 74
LIST OF TABLES
Table 6-1 Summary of Chemicals in Surficial Soil and Sediment ... 19
Table 6-2 Summary of Chemicals in Sediment of Olin Basin 22
Table 6-3 Summary of Chemical Detected in the Floodplain
Surface Water 25
Table 6-4 Summary of Chemicals of Potential Concern 27
Table 6-5 Summary of RME Cancer Risk for All Chemicals
(Current Land-Use) 29
Table 6-6 Summary of RME Non-Cancer Risk for All Chemicals
(Current Land-Use) . 30
Table 6-7 Summary of RME Risk for All Chemicals
(Future Land-Use) 31
Table 6-8 Tissue Analyses Plants 35
Table 6-9 Tissue Analyses Crayfish 36
Table 6-10 Tissue Analyses Bass 39
Table 6-11 Tissue Analyses Catfish 40
Table 6-12 Tissue Analyses Toad 41
Table 6-13 Tissue Analyses Reptile 43
Table 6-14 Tissue Analyses Raccoon Fat 45
Table 6-15 Tissue Analyses Raccoon Muscle 46
Table 6-16 Tissue Analyses Raccoon Liver 47
Table 6-17 Summary of Chemicals Detected in Terrestrial Biota .... 49
-11-
-------
LIST OF FIGURES
Figure 1-1 Site Location Map 1
Figure 2-1 Ecological Assessment Study Area 3
Figure 2-2 Former Waste Management Areas
Addressed in Operable Units #2 and #4 6
Figure 2-3 Site Map Including Facility 9
Figure 6-1 Map of Sample Locations 18
-iii-
-------
DECLARATION
Of the
RECORD OF DECISION
OPERABLE UNIT #3 McINTOSH FACILITY
SITE NAME AND LOCATION
Ciba-Geigy Corporation Superfund Site
Mclntosh, Washington County, Alabama
STATEMENT OF BASIS AND PURPOSE
This decision document (Record of Decision), presents the
selected remedial action for OU #3 at the Mclntosh Facility for
the Ciba-Geigy Corporation Chemical Superfund Site, Mclntosh,
Alabama, developed in accordance with the Comprehensive
Environmental Response, Compensation and Liability Act of 1980
(CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA) 42 U.S.C. Section 9601 et
sea., and to the extent practicable, the National Contingency
Plan (NCP) 40 CFR Part 300.
This decision is based on the administrative record for the Ciba-
Geigy Corporation Chemical Superfund Site ("the Site").
The State of Alabama, as represented by the Alabama Department of
Environmental Management (ADEM), has been the support agency
during the Remedial Investigation and Feasibility Study process
for the Ciba-Geigy Superfund Site. In accordance with 40 CFR
300.430, as the support agency, ADEM has provided input during
this process. The State of Alabama concurs with the selected
remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances (pollutants
or contaminants) from the Site, if not addressed by implementing
the response action selected in this ROD, may present an imminent
and substantial endangerment to public health, welfare and/or the
environment.
DESCRIPTION OF SELECTED REMEDY
This operable unit is the final of four operable units at the
Ciba-Geigy Site.
The major components of the selected remedy for operable unit
three include:
-------
* Excavation of approximately 2500 cubic yards of soil and
sediment above the cleanup level, 15 ppm DDTR. 15 ppm DDTR has
been determined to be the best balance of protection for the
environment based upon our present knowledge at the site.
Excavated soil and sediment would be treated with the OU #2 and
OU #4 soil if the concentrations is above 500 ppm DDTR.
* Soil excavated from the floodplain (OU #3) that is below 500
ppm DDTR may be used as subsurface backfill for excavated areas
of OU #2. Prohibiting the placement of soil or sediment with
concentrations greater than 500 ppm DDTR will ensure that
subsurface treatment levels established in the OU #2 ROD for
the protection of groundwater will not be exceeded. Based on
the current information, the majority of the soil and sediment
would be available to be used as subsurface backfill.
* Backfilling the excavated areas of the floodplain with clean
fill.
* In-situ bioremediation of approximately 10 acres of the more
ecologically sensitive areas (cypress swamp(s) and bottom land
hardwood forest) that exceed the cleanup level if Ciba-Geigy
demonstrates to EPA's satisfaction that in-situ bioremediation
will provide sufficient and timely degradation of all DDTR
without increasing the rate of methylation of mercury in areas
where the wastes are commingled. If Ciba-Geigy is unable to
demonstrate to EPA's satisfaction that 'in-situ bioremediation
will achieve all of the remedial goals for the area(s), the
ares(s) will be addressed by objective #2 of the Remedial
Design Study (below).
* Conducting Remedial Design studies to accomplish the following
objectives:
1. To provide the baseline levels which will be used to
monitor the long-term effectiveness of the remediation;
2. To determine if.it is necessary to modify cleanup goals in
different areas of the floodplain based on ecological
sensitivity (i.e., To avoid the unnecessary destruction of
habitats that may be irreplaceable by balancing the
effects of the contaminants with the effects of the
cleanup); and,
3. To select appropriate species to be used for measuring the
effectiveness of the remedy. To establish performance
standards or maximum contaminant levels in those species
to determine when site remediation is successful.
Based on the results of the Remedial Design studies, the cleanup
level mav be adjusted.
j.
If adjustments to the cleanup level are made, such adjustments
will be published in a fact sheet, BSD, or ROD Ammendment.
-------
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with federal and state requirements that
are legally applicable or relevant and appropriate to the
remedial action, and is cost-effective. This remedy utilizes
permanent solutions and alternative treatment or resource
recovery technologies, to the maximum extent practictable.
However, because treatment of the principal ecological threats of
the site was not found to be practicable, this remedy does not
satisfy the ststutory preference for treatment as the principal
element. Finally, it is determined that this remedy maximizes
long-term effectiveness.
Because this remedy would result in hazardous substances
remaining on-site, a review would be conducted within five years
after commencement of the remedial action to ensure that the
remedy continues to provide adequate protection of human health
and the environment.
Richard D. Green, Associate Director of DATE
Superfund and Emergency Response
-------
>..'%'.
1.0 SITE LOCATION AND DESCRIPTION
The Ciba-Geigy Mclntosh facility is located two miles northeast of
Mclntosh, Alabama and approximately 50 miles north of Mobile,
Alabama. The property is bounded by a pine forest to the north
(Boykin property) , Olin Corporation Property to the south, and the
Tombigbee River to the southeast. The nearest residents are
approximately 1.5 miles to the west and the south. Approximately 300
residents live within a 3 mile radius.
The entire Ciba-Geigy property encompasses approximately 1,500 acres,
of which 1,130 acres (2.4 sq miles) consists of developed plant site.
The remaining 370 acres consists of undeveloped swamp and bottomlands
that comprise a portion of the Tombigbee River floodplain. The
floodplain is separated from the developed portions of the plant
property by a steep escarpment known as the "bluffline."
COUNTY.
i
1
CIBA-GEIGY
CORPORATION
FIGURE 1-1 LOCATION OF SITE
-------
The portion of the floodplain owned by Ciba-Geigy Corporation has
been modified from its pre-development condition beginning in 1952.
In 1955, discharge from an effluent impoundment flowed along the
southern edge of the manufacturing facility eastward toward the
bluffline then discharged to the Tombigbee river via an effluent
ditch which was constructed to convey the wastewater to the Tombigbee
River. The river water pump station was constructed in 1962 to
supply process water to the production facilities on the upland
terrace.
In 1965, waste waters were routed through new impoundments for
treatment. Effluent from the impoundments was discharged to the
effluent ditch which was rerouted to its present-day location along
the southern edge of the property to the Tombigbee River. The
transporting of effluent from empoundments to the Tombigbee River
and migration of contamination from nearby upland former waste
management areas during periods of heavy rainfall or flooding were
the primary sources of contamination in the floodplain. The nearby
upland former waste management areas are a part of the OU#2 and OU#4
cleanup.
The effluent diffuser line was constructed in late 1968 to convey
wastewater effluent and to provide a mixing mechanism for the
effluent as it was discharged to the Tombigbee River. The pipeline
diffuser section was anchored to the river bottom. The effluent
diffuser line was taken out of service in late 1973 when the
biological treatment system was constructed
In 1973, a biological treatment system was constructed east of the
manufacturing area. From 1973 until 1988 all treated wastewater from
the biological treatment system and all neutralized dilute wastewater
and impounded stormwater from the dilute impoundment was discharged
to the effluent ditch via gravity pipelines. These effluents were
combined with once-through, non-contact cooling water in the effluent
ditch to make up the plant's NPDES discharge. The effluent ditch
remains in use for stormwater overflow. Treated effluent now
traverses the floodplain in an enclosed elevated pipeline.
Two areas were identified in the floodplain which manifest evidence
of vegetative stress. The largest area was located immediately below
the bluff line and a second area was located adjacent to the first,
southwest of the former effluent ditch. The vegetative stress was
believed to have been caused principally by former soil erosion and
deposition from the adjacent bluffline.. Erosion from the bluffline
area was halted in 1985 by stabilization of the escarpment with
extensive rip-rap and improvement of the vegetative cover of the
bluffline surface. At the time of the RI Field Investigations
(1988), natural revegetation of the stressed areas had begun. The
intervening years since that study have seen a marked increase in the
areal extent and density of vegetation in these areas.
-------
BOYKIN PROPERTY
CIBA-GDGY
STORMWATER BITCH
(FORMER EFFLUENT-;DITCH)
LEGEND
SEDIMENT AND SURFACE
WATER SAMPLE
STUDY AREA E) SOIL SAMPLE
WETLANDS
PROPERTY LINE
TRANSECT LINE
SURFACE WATER
CIBA-GE1GY CORPORATION
UclNTOSH, ALABAMA
ECOLOGICAL ASSESSMENT
FIGURE 2-1
STUDY AREA
1892
0. BURFORD
-------
In 1986, portions of the floodplain property along the south road
near the river were seasonally used to collect newly deposited river
sediment which was used as top soil. The floodplain is well drained
during periods of low water due to an active maintenance program in
which drainage conduits and ditches are regularly cleaned of beaver
dams and trapped debris which otherwise tend to retard the drainage
in the floodplain. Aside from the effluent ditch and newer effluent
conveyances, the floodplain has not been utilized for waste
management.
In December 1988 the use of the effluent ditch as a conduit for
treated wastewater was discontinued. An above-ground pipeline now
conveys treated effluent from the new waste waster treatment system
which was brought on line at that time. The effluent pipeline
follows the course of the effluent ditch to the Tombigbee River.
Approximately 500 feet before reaching the river, the diffuser line
descends below ground and emerges on the river bottom where waste
water is diffused along the width of the river.
The dominant surface water bodies in the region surrounding the Site
are the Tombigbee and Alabama Rivers. The Tombigbee River is
characterized as a large, meandering river surrounded by numerous
oxbow lakes and wetlands. The Tombigbee River originates in
northeastern Mississippi and flows 442 river miles south to its
confluence with the Alabama River. The Tombigbee and Alabama Rivers
form the Mobile River, which then flows south another 45 river miles
until it empties into Mobile Bay in the Gulf of Mexico. The gentle
regional slope has resulted in very broad floodplains along each of
the rivers; large portions of the Tombigbee River Valley (including
the floodplains in the vicinity of Mclntosh) are flooded annually.
There are relatively few areas of ponded water within the study area
that are wet enough to support aquatic life throughout the year.
Within the Ciba-Geigy floodplain, these are limited to the stormwater
drainage ditch (formerly the effluent ditch), which parallels the
south floodplain road for most of its course in the floodplain, and
the northern drainage ditch that parallels the north floodplain road.
A drainage area below the bluffline contains water for most of the
year. In addition to the Tombigbee River, the principal off-site
aquatic habitats are the Olin drainage which includes a small cypress
swamp, a connecting drainage way and associated depression, and Olin
Basin, which is a lake occupying approximately 65 acres. Additional
aquatic habitat is provided by Johnson Creek which flows seasonally
through the northern portion of the Ciba-Geigy property onto the
adjacent Boykin property where it has been dammed, creating a
permanent water body. The only aquatic habitat of sufficient depth
throughout the year to sustain populations of large fish is the Olin
Basin and ponded portions of Johnson Creek.
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
-------
The Ciba-Geigy Mclntosh facility, formerly owned by Geigy Chemical
Corporation, began operations in October 1952, with the manufacture
of one product, dichlorodiphenyl-trichloroethane (DDT).Though 1970,
Geigy expanded its Mclntosh faciities by adding the production of
fluorescent brighteners used in laundry products; herbicided;
insecticides; agricultural chelating agents; and sequestering agents
for industry. In 1970, Geigy merged with Ciba (Chemical Industry in
Basel, Switzerland), forming Ciba-Geigy Corporation.
The EPA Region IV Environmental Services Division of Athens, Georgia
(BSD) conducted an investigation in August 1982 of the Olin Chemical
Company located adjacent to the Ciba-Geigy Site. As a part of the
investigation, BSD sampled a drinking water well on Ciba-Geigy
property. This sampling indicated the presence of hazardous
substances which warranted further evaluation of the contamination
problem at Ciba-Geigy. In June 1983, the Hazardous Ranking System
(HRS) survey was completed and the Site was assigned a ranking of
53.42. The Ciba-Geigy Mclntosh Plant was included on the National
Priorities List (NPL) in September 1983.
In October 1985, EPA issued Ciba-Geigy a RCRA permit, which included
a corrective action plan requiring Ciba-Geigy to remove and treat
contaminated groundwater and surface water at the site. The
corrective action plan stipulated that Ciba-Geigy would prepare a
Remedial Investigation/Feasibility Study (RI/FS) for the disposal
areas being studied by the Superfund program. Figure 2 depicts the
location of CERCLA areas within the Ciba-Geigy Site.
The ten units closed under the RCRA permit include:
Diazinon Wastewater Sewer: Utilized to pipe Diazinon waste
to the Diazinon Destruct Impoundment. Closure under post
closure care in 1976.
Triangular Impoundment: Constructed in the 1970s to
decompose Diazinon residues. Closure during interim status
completed in 1986.
Rectangular Impoundment: Constructed in 1972-1973 to hold
sludge from the dilute impoundment. Closure during interim
status completed in 1987.
Class C Landfill: Permitted by Alabama in 1973 and permitted
under RCRA Interim Status regulations. Closure during
interim status completed in 1987.
Biological Sludge Landfill: Permitted by Alabama in 1978 and
later operated under RCRA Interim Status for disposal of
dewatered sludge. Closure during interim status completed
in 1987!
Diazinon Degtruct Impoundment: Constructed in 1965.
Closure under post closure care completed in 1989.
-------
Alabama
Figure 2-2
CI8A-GEIGV Sit* Boundary
WASTE
___M DISPOSAL
OPEN P|TS
•URN 4
AREA
DISPOSAL
SITE
SOUTH or
THE CLASS
C LANDFILL
•HC
AREA
WAREHOUSE \ /
NO. an x*
10
ORIGINAL
EFFLUENT
IMPOUND
MENT
AREA OF CONTAMINATION /
J
CIBA - GEIGY CORPORATION
PLANT SITE
MclNTOSH. ALABAMA
TRASH
STAGING
AREA
If
TEMPORARY •
TRASN %
STAGING
AREAS
-------
GM-44 Impoundment: Put into service in early 1970s.
Constructed for the GM-44 wastes high in nitrogen compounds.
Its use was discontinued in the late 1970s. Closure under
post closure care completed in 1989.
Effluent Diffuser Line: Constructed in late 1968 to convey
effluent for discharge into the Tombigbee River. Taken out
of service in 1973 due to a change in the wastewater
treatment system, closure of RCRA impoundments, and a change
in the NPDES permit.
Effluent Disposal Well: Installed in 1971. Used for the
injection of biotreated effluent to reduce the quantity of
NaCl discharged into the river. The use of the well was
unsuccessful and it was plugged in 1983. ADEN required no
post-closure monitoring.
Dilute Ditch: This ditch collected dilute wastewater and
surface water runoff to be conveyed to the Dilute
Impoundment. Use ceased in 1971. Continued monitoring of
this ditch under a RCRA Corrective Action permit.
/
N
Pursuant to the Corrective Action portion of the permit, in 1987,
Ciba-Geigy installed a groundwater pumping system to intercept and
remove contaminated groundwater from the shallow alluvial aquifer.
The water removed from these wells was treated in the plant's
existing on-site wastewater treatment system until fall 1988, when
the plant's new biological wastewater treatment system was completed
and used to treat the groundwater. The treated water is discharged
into the Tombigbee River in compliance with appropriate National
Pollutant Discharge Elimination System (NPDES) Regulations.
Ciba-Geigy has installed four (4) corrective action monitoring wells
along the southern boundary of the property to monitor the
effectiveness of the pumping well system. The effectiveness of the
pump and treat system in preventing the migration of contaminated
groundwater off-site and reducing the concentrations of contaminants
in the groundwater is well established.
EPA completed the Superfund decision document (the Record of Decision
or ROD) for operable unit one in September 1989 after public comments
were carefully considered. The ROD identified the EPA selected
remedy, "No Further Action". This selection was based on the
established effectiveness of the groundwater pump and treat system
already installed under the RCRA.permit to address groundwater
contamination in the shallow aquifer at the Site.
In accordance with the corrective action plan, Ciba-Geigy retained
BCM, a technical consultant, to perform the RI/FS. Field work, which
began in October 1985, was conducted by BCM on Ciba's behalf, with
EPA's oversight. The principal finding of the RI study was the
-------
definition of the extent of contamination from eleven additional
waste management areas within the study area that would be addressed
under CERCLA.
The CERCLA Site has been grouped and divided into two Areas of
Contamination (AOCs) based on their relative proximity to each other.
The AOCs are roughly separated by the reservoir (See Figure 2).
In January 1990, Ciba-Geigy submitted the FS report. This report
identified and screened alternatives for cleanup at the eleven former
waste management areas. In September 1991, EPA issued a ROD
addressing soil contamination at 10 of eleven 11 former waste
management areas, (OU2), at the Site. In July 1992, EPA issued a ROD
addressing soil contamination at the eleventh former waste management
area (the bluffline Area 8).
The major components of the selected remedies for OU #2 and OU #4 as
presented in November 1993 Explanation of Significant Differences and
the Notice of Final Remedy Selection section of the December 1994
Fact Sheet include:
Excavation of contaminated soils and sludges until
established cleanup levels are reached or until site specific
excavation limits are reached;
On-site thermal treatment of approximately 240,000 cubic
yards of highly contaminated soils and sludge;
Treated soil and residual ash from the thermal treatment
process which meet Land Disposal Restriction treatment
standards are considered decontaminated and may be used as
backfill for the excavated areas;
In-situ soil flushing combined with isolation walls and
extraction wells to remediate areas where the risk based cleanup
levels are not achieved before, excavation depth of 2O feet is
reached;
Issuing a public notice in a local newspaper and sending a fact
. sheet to persons on the mailing list at the completion of the 30%
design report. The purpose of the fact sheet and the public
notice would be to inform the public of the technologies selected
that were proven effective during the treatability studies
conducted during the remedial design - addressed in the December
1994 Fact Sheet;
Vegetating the area and establishing a suitable vegetative cover;
and,
Institutional controls for land use and groundwater use.
Ciba-Geigy signed an Administrative Order by Consent (AOC), effective
March 31, 1992 with EPA to determine the potential ecological impact
8
-------
of contaminants in the floodplain, characterize any threat to public
health, welfare or the environment. Based on the data results from
the Ecological Assessment/RI Report Addendum, DDE, DDT, DDD,
atrazine, diazinon, simazine, butylbenzylphthalate and all
herbicides were selected as Contaminants Of Potential Concern (COPCs)
for evaluation of the floodplain risk assessment. In addition, Ciba-
Geigy was required to develop and evaluate alternatives for remedial
action.
EPA will continue its CERCLA enforcement activities and will notify
Ciba-Geigy prior to the initiation of the remedial design for
participation in the selected remedial action. Should Ciba-Geigy
decline to conduct future remedial activities, EPA will either take
additional CERCLA enforcement actions or provide funding for these
activities while seeking cost recovery for all EPA-funded response
actions at this Site.
BLUFFUNE
figure 2-3 Site Map
-------
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
The RI for the Ciba-Geigy Site was released to the public in
August 1988. The FS and the Proposed Plan for the Ciba-Geigy
Site addressing Operable Unit 2, were released to the public on
July 30, 1990. An addendum to the FS addressing the
contamination in Area 8 (OU #4), and the Proposed Plan addressing
OU #4 was released to the public in April 1992. The Remedial
Investigation Report Addendum / Ecological Assessment Report was
released to the public in April 1994. The FS addendum and the
Proposed Plan addressing contamination in the floodplain area (OU
#3) was released to the public in December 1994. These documents
were made available by placement in both the administrative
record docket and the information repository maintained at the
EPA docket room at Region IV Headquarters in Atlanta, Georgia and
at the Mclntosh Town Hall, in Mclntosh, Alabama. Pursuant to
regulations, a public comment period was held from December 15,
1994 through January 14, 1995.
A notice was placed in the Mobile Press Register on December 15,
1994 announcing the comment period. In addition to the public
comment period and the administrative record files, a public
meeting was held on December 20, 1994 in Mclntosh Alabama. At
this meeting representatives from EPA answered questions and
addressed community concerns.
A response to all significant comments received during the public
comment period is included in the Responsiveness Summary
(Appendix A), which is a part of this Record of Decision.
This decision document presents the selected remedial action for
operable unit three of the Ciba-Geigy Site, chosen in accordance
with CERCLA, as amended by SARA and to the maximum extent
practicable, the NCP. The decision for this Site is based on the
administrative record. The requirements under Section 117 of
CERCLA/SARA for public and state participation have been met for
this operable unit.
4.0 SCOPE AND ROLE OF OPERABLE UNITS
Due to the size of the facility, the number of areas and the variety
of contaminants, the problems at the Ciba-Geigy Site are complex. As
a result EPA has organized the work into four (4) operable units
(OUs). The operable units at this Site as identified in the ROD
issued for Operable Unit Two in September 1991 are:
OU #1 Contamination of the shallow (Alluvial) groundwater aquifer.
The groundwater pump and treatment system is currently
operating.
OD #2 Contamination of soils at ten of eleven former waste
management areas. The remedial design to implement this
10
-------
source control action is currently being prepared by Ciba-
Geigy.
OD f3 Contamination within the floodplain, the effluent ditch
(previously called the lower portion of the dilute ditch) and
areas in the Tombigbee River within close proximity to the
Site.
OU #4 Contamination of soils in former waste management Area 8 and
the dilute ditch (previously called the upland portion of the
dilute ditch). The remedial design to implement this source
control action is currently being prepared by Ciba-Geigy.
This Operable Unit (OU #3), addresses the contamination within the
floodplain area and the lower portion of the effluent ditch at the
Site. The upper portion of the effluent ditch was closed in
accordance with an approved RCRA Closure Plan. The ditch, as well as
other closed units, was excavated, capped, and is being maintained
through RCRA Post-Closure care. Upon further evaluation, EPA has
decided to continue addressing the effluent ditch under RCRA
authority, as administered through the HSWA Permit. In addition, the
Tombigbee River close to the site will not be discussed in this
operable unit because they are currently being addressed in the Mobile
River Study.
The January 1990 Feasibility Study Report and the February 1992
addendum to the Feasibility Study Report submitted by Ciba-Geigy
document the development, screening and detailed evaluation of
potential alternatives for remediation of the former waste management
areas identified and characterized during the Remedial Investigation.
The July 1994 Feasibility Study Report Addendum documents the
screening and evaluation of potential alternatives for remediation of
the floodplain area. EPA has evaluated the alternatives considered
for remediation of the floodplain area and the risk posed by the
contaminants as they relate to the "CERCLA" Site. Based on this
evaluation, EPA has determined which alternative or combination of
alternatives would achieve the CERCLA cleanup objective, to remediate
the source of the contamination, minimize the migration of the
contamination from the soil/sediment to the groundwater/surf ace water,
and prevent current or future exposure to contaminated groundwater or
other environmental receptors. The approach to this operable unit is
consistent with past work conducted at the Site.
5.0 SUMMARY OF SITE CHARACTERISTICS
The following sections describe the general characteristics at the
site.
5.1 PHYSIOGRAPHY/GEOLOGY/CLIMATE
The Study Area is located in the Southern Pine Hills District of the
East Gulf Coastal Pl^iin Physiographic Province and is situated in the
bottomland floodplain adjacent to the Tombigbee River. The Southern
11
-------
Pine Hills is a moderately dissected plain that slopes gently to the
south. In vicinity of the Site, the Tombigbee River is characterized
by broad meanders and numerous oxbow lakes in a well developed
floodplain. Elevations range to about 10 feet (MSL) and slopes range
from zero to one percent in the Ciba-Geigy Corporation floodplain.
This floodplain is separated from the adjacent upland terrace by a
distinct escarpment having as much as 35 to 40 feet in relief and
locally known as "the bluffline". The natural site topography has
been locally modified with the development of floodplain roads and
barrow, the construction of the effluent ditch, and the riverward
extension of the bluffline.
The three prominent geologic structures in the region are the Mclntosh
Salt Dome, the Jackson Fault System, and the Mobile Graben. The
Mobile Graben has been identified as a downthrown block fault
paralleling the Tombigbee River. The Jackson Fault represents the
easternmost upthrown fault boundary of the Mobile Graben. The
westernmost upthrown fault boundary is not manifested as a surface
displacement. The Mclntosh Salt Dome is located approximately two
miles southwest of the Study Area. The dome pierces the Miocene
sediments within 440 feet of the ground surface and is approximately
one mile in diameter. Southwestern Washington County is underlain by
recent alluvium, Pleistocene age low terrace deposits, and sediments
comprising the Miocene Series Undifferentiated. These strata consist
of alternating deposits of sand, clay, silt, and gravelly sand.
Ciba-Geigy is situated upon a low terrace immediately adjacent to the
Tombigbee River floodplain. A continuous surficial clay layer is
underlain by deposits of silt, sand, gravel, and clay. The surficial
clay layer ranges in thickness from only a few feet to over 50 feet.
The contact with the underlying sand is characterized by sandy clay,
sand and gravel. These Pleistocene deposits range in thickness from 60
to 100 feet. The Pleistocene deposits unconformably overlie more, than
700 feet of alternating layers of Miocene age sand, gravels, and
clays.
This region is characterized by the absence of exceptionally cold
winters and the presence of high humidity. The relatively mild
temperatures in south Alabama allow for a long growing season, ranging
from approximately 230 days in southern Washington County to 300 days
along the coast. Killing frost may not occur until early November in
southern Washington County, and the last winter frost may be expected
in mid-March.
Annual rainfall in south Alabama is among the highest in the
contiguous United States, averaging about 64 inches. The
precipitation is relatively evenly distributed over the year although
there is a small peak in July during the thunderstorm season. July
rainfall averages 7.6 inches. The driest season runs from October
through November when the monthly average is 3.5 inches.
Thunderstorms, the predominant mode of precipitation, occur on average
80 days a year, although more frequently in the summer than other
seasons.
12
-------
The Mclntosh floodplain is a seasonally dynamic system influenced to a
large extent by frequency and duration of inundation. Due to the
seasonal variations in water depth and rainfall in the region, the
entire floodplain is flooded for 3 to 5 months of the year (typically
from December to April). In the vicinity of the Site, areas 25 feet
in elevation and below are typically inundated with water during this
period; these areas may be under 10 feet of water or more during part
or all of the period of inundation.
Much of the floodplain is contiguous with the Tombigbee River during
periods of complete inundation, and movements of fish and other
aquatic organisms are largely unrestricted. From mid-to late spring,
water begins to recede due to decreased flow rate in the Tombigbee
River, decreased precipitation, and increased evaporation. The amount
of available aquatic habitat shrinks as water collects in pools and
depressions on the floodplain. Gradually throughout the summer months
aquatic habitat becomes restricted to the areas of permanent water
described above.
5.2 SOILS
The Ciba-Geigy Corporation floodplain is comprised of soils which
include Urbo series in the upper half nearest the bluff line and the
Ochlockonee series in the riverward half. The Urbo series consists of
fine, mixed acid soils. The A horizons are predominantly silty clay
loams with B horizons consisting of silty clay. These soils are
formed in floodplain sediments throughout the Coastal Plain. Urbo
series soils are somewhat poorly drained and are very slowly
permeable. The Ochlockonee series consists of deep, well drained,
loamy soils. These are formed in the alluvium of floodplains
throughout the Coastal Plain. Within the study area these soils are
restricted to those floodplain areas immediately adjacent to the
Tombigbee River. Soil and sediment samples collected during this
Ecological Assessment were subjected to sedimentary petrological
analyses.
5.3 SURFACE WATER HYDROLOGY
The Tombigbee River flows in a southeasterly direction from its
headwaters in northeastern Mississippi where it is linked to the
Tennessee River, to its confluence with the Black Warrior River near
Demopolis, Alabama, 267 miles downstream. From Demopolis, the
Tombigbee flows south 175 miles where it converges with the Alabama
River to form the Mobile River. The Mobile River flows south 45 miles
to Mobile, entering into the Mobile Bay estuary. Significant portions
of the Tombigbee River are flooded annually including the study area
floodplain.
During low river stages, surface water features in the study area
include Olin Basin and associated wetlands and depressions, and a
portion of Johnson Creek which enters the floodplain on adjacent
Boykin property north of the Ciba-Geigy Corporation property. Johnson
Creek has been impounded and during low river stages forms a narrow
13
-------
pond (Boykin Pond) having a width of approximately 100 to 250 feet and
a length of approximately 4500 feet.
5.4 BIOTA OBSERVATIONS
The flora and fauna in the vicinity of the Ciba-Geigy Corporation,
Mclntosh facility are typical of those found in the southern portions
of the Alabama Coastal Plain. The Ciba-Geigy Corporation property
exhibits floral species characteristic of bottomland floodplain
forests as well as upland mixed hardwood-pine forests.
There are three vegetative communities within the floodplain:
cypress-tupelo swamp, bottomland hardwood forest, and clearings.
Cypress-tupelo forests occur in semi-permanently flooded areas that
are flooded all of the dormant season (November through March) in most
years. Trees in these areas are limited to those that can withstand
extended periods of flooding. Tree species in these areas are
dominated by bald cypress and water tupelo.
Bottomland hardwood forests occur in temporarily flooded areas which
are generally flooded from December through March. The southern
floodplain forests are dominated by various species of oak. The
groundcover in mature bottomland hardwood stands is sparse because of
the limited amount of light that penetrates the dense forest canopy.
Also, in clearings and open areas on the floodplain herbaceous species
are abundant.
The faunal assemblage found in the vicinity of the Site includes
mammals such as opossums, moles, shrews, armadillos, rabbits, fox,
raccoons, and white-tailed deer. Over 300 species of birds are found
in the Lower Coastal Plain. Many species may be found in the vicinity
of the Study Area. Representative amphibians and reptiles include
frogs, toads, and salamanders, as well as the American alligator and
numerous species of snakes.
Wetlands are typically highly productive and diverse systems that
constitute habitat of high value to wildlife. They are important
breeding grounds for migratory waterfowl and numerous other birds and
also provide cover, forage, and resting and rearing habitat for birds,
mammals, reptiles, and amphibians. In general, wetlands that contain
a diversity of flora and provide several vegetative strata (e.g.,
shrub layer, herbaceous layer) have a greater habitat value because
they provide more food, cover, and reproductive resources to a greater
number of animals. Also, in general, larger wetlands that are
continuous with other wetlands or habitat areas provide better habitat
than smaller, isolated wetlands.
The wetlands in and around the Ciba-Geigy Mclntosh floodplain are
ranked as highly effective for promoting wildlife diversity and
abundance by providing breeding, migration, and wintering habitat.
The wetlands are used by migrating and resident waterfowl, wading
birds, songbirds, raccoons, deer, and other species. It is important
to keep in mind that the wetlands contained within the area represent
14
-------
only a fraction of the wetlands that occur in the local area and in
the region.
The floodplain characteristics change seasonally, and with that, the
amount of terrestrial habitat that is available also changes. In the
winter and spring when the seasonal flooding occurs, the Site is used
by a variety of wintering and migrating waterfowl, consisting mainly
of the dabbling ducks such as mallard, pintail, blue-winged teal, and
wood duck (Aix sponsa). The Site is used as breeding habitat by some
birds although the highest concentrations of breeding birds are found
further south in the river delta. More terrestrial-based wildlife
(e.g., many mammals) likely are concentrated in the upland portions of
adjacent lands. During summer and fall when waters recede, waterfowl
usage decreases and wading bird species use increases. Great blue
heron, green-backed heron, little blue heron, great egret, and snowy
egret have been observed feeding in pools and swamp on-site. More
terrestrial wildlife species also likely increase the use of the
floodplain at this time.
Mammals known to occur at the site include raccoon, opossum,
cottontail, muskrat, armadillo, and white-tailed deer. Other species
likely to occur are swamp rabbit, river otter, and mink. Based on
the results-of field surveys both on the Ciba-Geigy property and at
the nearby Fred T. Stimpson Wildlife Sanctuary, small mammals (e.g.,
rodents, shrews) do not appear to be abundant on the floodplain of the
Tombigbee River. This is likely, related to the limited herbaceous
layer that is characteristic of swamps and bottomland hardwood
forests, since small mammals rely on the herbaceous layer to provide
forage and cover from predators. An additional factor which may
influence the abundance of small mammals on floodplains is that, due
to their smaller home range, much of the floodplain is too distant
from the habitat they use when the floodplain is inundated.
The only rare, threatened, or endangered species known to occur on the
Mclntosh site is the American alligator (Alligator mississippiensis),
which is classified as "threatened due to similarity of appearance
(T/SA)". This classification is assigned to the alligator because of
its similarity to the American crocodile (Crocodylus acutus), which is
a Federal endangered species. Populations of the American alligator
are not considered ecologically threatened at this time. Because of
the T/SA status, State authorities closely regulate the harvesting of
alligators by issuing a limited number of hunting permits and by
tracking the skins of the harvested animals to ensure that the skins
are not those of the endangered crocodile.
6.0 SUMMARY OF SITE RISK
CERCLA directs the Agency to conduct a baseline risk assessment to
determine whether a Superfund Site poses a current or potential threat
to human health and the environment in the absence of any remedial
action. The baseline risk assessment provides the basis for
15
-------
determining whether or not remedial action is necessary and the
justification for performing remedial action.
6.1 CONTAMINANTS OF CONCERN
Soil/Sediment
Soil and sediment samples were collected in May and June 1992 along
Transects A through E and a background area. Six samples were
collected from Transects A, B and C for a total of 18 samples. Three
samples were collected from Transects D and E for a total of six
samples (see Figure 6-1). Fourteen additional samples (Fl through
F14) were collected throughout the floodplain in areas between the
transects. The F-series samples were analyzed only for DDD, DDE and
DDT. Six soil/sediment samples were collected from the background
area. Eighteen additional samples containing DDTR were collected by
Woodward Clyde in the Olin Basin under another CERCLA investigation.
Tables 6-1 and 6-2 present a summary of chemicals detected in
surficial soil and sediment in the Ciba-Geigy floodplain and a summary
of chemicals detected in the sediment of the Olin Basin respectively.
The summary tables present the frequency of detection, the mean, the
number of samples used to calculate the mean, the range of detection
limits, and the range of detection limits.
Floodplain
DDE, DDT and DDD were the most frequently detected organic chemicals
and were present in greater than 60% of all soil/sediment samples
collected- from the floodplain. Concentrations were greatest in
samples collected from or near drainage ways and from areas closest to
the bluffline. Concentrations throughout the remainder of the
floodplain were lower and generally less than 100 ug/kg. The highest
concentration of DDT (152 mg/kg), was detected at sample location Cl.
Although fewer data are available, the distribution of other
frequently detected organic chemicals within the floodplain appear to
follow somewhat a similar pattern. For example, ,the highest
concentrations of 5 of the remaining 10 insecticides (alpha-, beta-,
and delta-BHC, chlorobenzilate, and hexachlorobenzene) were found near
the drainage ways or close to the bluffline. Most of the other
highest concentrations of contaminants (including herbicides) were
detected in other portions of the D-transect drainage way or near the
bluffline.
Olin Basin
DDE, DDD, and DDT were the most frequently detected organic chemicals
in the Olin Basin (19 out of 19 samples). The concentrations of these
chemicals, however, were substantially below those detected in the
floodplain.
Chlorobenzene, which was not detected in the floodplain, also was
detected in all Olin Basin samples. Hexachlorobenzene (8/19) was the
most frequently detected of the remaining organic chemicals at a
16
-------
concentration significantly greater than the single floodplain sample
in which it was detected.
In contrast to the floodplain, several inorganic chemicals were
detected in the Olin Basin at concentrations significantly
(statistically) above background. Antimony, copper, cyanide, mercury
sodium and zinc were the inorganic chemicals detected above
background.
Surface Water
A total of 18 surface samples were collected in May and June 1992.
Three samples each were collected from Transects A, B, C, D, E and
from the background Area. Table 6-3 contains the summarized surface
water data. Table 6-4 identifies chemicals of potential concern for
surface soil/sediment, surface water and biota.
17
-------
BOTKIN PROPERTY
CJBA-GOGY
STORMWATER DITCH
(FORMER EFFLUENT:DITCH)
LEGEND
STUDY AREA
WETLANDS
PROPERTY UNE
TRANSECT LINE
SURFACE WATER
E SOIL SAMPLE
A SEDIMENT AND SURFACE
WATER SAMPLE
CIBA-GCIGY CORPORATION
MelHTOSH. ALABAMA
ECOLOGICAL ASSESSMENT
FIGURE 6-1
STUDY AREA
-------
19-Apr-94 newfpSS.WBl
Table 6-1
SUMMARY OF CHEMICALS DETECTED IN SURRCIAL SOIL AND SEDIMENT: FLOODPLAIN
ECOLOGICAL ASSESSMENT
(Concentrations reported in ug/kg for organics, mg/kg (or Inorganics)
Frequency ol
Chemical (a) Detection (b)
ORGANICS: •>
Herbicides:
+ Ametryn (g)
*+ Atrazine
+ Prometon (g)
+ Prometryn (g)
+ Propazina (g)
*+ Sima/ine
+ Simetryn (g)
+ Terbuthylazine (g)
+ Teibutiyn (g)
+ Tolban (g)
Insecticides:
alpha-BHC (g)
bela-BHC (g)
delta-BHC (h)
Chlorobenzilate (g)
• ODD
• DDE
• DDT
• Diazinon
Heptachlor. Epoxide (h)
Hexachlorobenzene (h)
Other Organic Chemicals:
Benzo(b)fluoranthene (h)
' Butyibenzylphthalate
Chlorobenzene (g)
Chloroform (g)
Chrysene (h)
Dibenzofuran (h)
Di-n-butytphthalate (g)
Fluoranthene (g)
2-Nitrpaniline (h)
12 / 23
7 / 23
3 / 23
8 / 23
5 / 23
5 / 23
8 / 23
3 / 23
6 1 23
3 / 23
3 / 23
2 / 23
1 / 23
6/23
22 / 37
25 / 37
24 / 37
2 / 23
1 / 21
1 / 23
1 / 23
11 / 23
2 / 23
6/23
1/23
1/23
14 / 23
4 / 23
1 / 23
Mean
Sample
Size (c)
23
23
23
23
23
23
23
23
23
16
23
23
23
23
37
37
37
23
21
2
1
23
2
23
1
1
23
4
23
Range of Detected Concentrations (d)
Mean
Concentration (d)
152
1,880
18.3
.43.7
563
1.500
22.2
72.2
38.2
17.7
42.6
40.4
35
463
3,730
3,820
3,000
16.2
11.5
197
NC
398
3.5
15.3
NC
NC
1.690
67.5
770
Range of
Detection Limits (d.e)
7.4 - 28
5.3 - 21
12.8 - 55
6.2 - 24.5
4.6- 18.
11.6-46
17.1-65
4.9-19.5
11.8-46.5
12.7-44.1
2.21 • 240
2.21 - 240
2.21 • 240
21 - 2220
4.20 - 29.8
4.39 - 53.2
4.39 - 29.8
16-70
2.21 • 108
389
NA
419-1,600
NA
12-56
NA
NA
420-1.600
NA
944-3,880
On-slte
9.25 - 2,200
.6 - 35,000
46 • 110
11.5 - 510
5.75 - 8.300
14 - 32,000
21 - 90
33 - 1,500
. 26 - 360
10-100
2.75 - 530
6 • 610
490
19 - 6,500
18.2 - 67,000
25.3 - 51.000
15.5 • 57.000
28 - 76
89
200
83
13 • 1.400
3 • 4
0.5 - 160
42
110
920 - 5.200
22 - 170
2.200
Background (e,f)
ND(7.6-15)
ND(5.6-11)
ND(15-30)
ND(6.6-13)
• ND (4.8 - 9.7)
ND(12-25)
ND(17-35)
ND(5.2-11)
ND(12-25)
NO (13 -30)
ND (2.3 -5.1)
ND (2.3 -5.1)
ND (2.3 -5.1)
ND (21 - 49)
ND (40.4 • 93.9)
ND (25.4 - 56.9)
ND (25.4 • 56.9)
ND(19-38)
ND (2.3 -5.1)
ND (409- 1,200)
ND (409 -1.200)
ND (409 -1,200)
ND(13- 1,500)
0.8 - 0.2
ND (409-1, 200)
ND (409 -1,200)
ND (410 -1,500)
140
ND (992 - 2.910)
See footnotes at end of table.
-------
19-Apr-94 newfpSS.WBI
Table 6-1 (Cont.)
SUMMARY OF CHEMICALS DETECTED IN SURFICIAL SOIL AND SEDIMENT: FLOODPLAIN
ECOLOGICAL ASSESSMENT
(Concentrations reported In ug/kg for organics, mg/kg for Inorganics)
Chemical (a)
ORGANICS (cont.):
Other Organic Chemicals:
Nitrobenzene (h)
Phenanthrene (g)
Pyrene (g)
Toluene (g)
INORGANICS:
. Aluminum (!)
Arsenic (i)
Barium (i)
Beryllium (i)
Calcium (!)
Chromium (!)
Cobalt (i)
Copper (!)
Cyanide (!)
Iron (!)
Lead (!)
Magnesium (!)
Manganese (i)
Mercury (i)
Nickel (i)
Potassium (i)
Selenium (!)
Silver (i)
Sodium (i)
Vanadium (i)
Zinc (i)
Frequency of
Detection (b)
1 i
2 :
3 ,
5 .
23 ,
20 ,
23 ,
22 ,
23 ,
23 ,
23 ,
23 .
5 ,
23 i
23 /
23 /
23 i
23 i
22 ,
21 I
2 i
8 i
18 i
23 i
23 i
! 23
1 23
t 23
1 23
1 23
t 23
1 23
t 23
1 23
1 23
1 23
1 23
' 23
i 23
' 23
r 23
1 23
f 23
' 23
' 23
f 23
1 23
' 23
' 23
1 23
Mean
Sample
Size (c)
1
2
3
22
23
23
23
23
23
23
23
23
23
23
23
23
23
23
23
23
22
22
23
23
23
Range of Detected Concentrations (d)
Mean
Concentration (d)
NC .
88
59.3
8.48
22,700
5.18
125
1.24
10,900
39.2
13.7
21.2
0.079
33,330
22.3
1840
448
4.48
16.7
1370
0.357
1.42
289
54.3
90.8
Range of
Detection Limits (d,e)
NA
NA
NA
12-50
NA
0.24-0.41
NA
0.21
NA
NA
NA
NA
0.06 - 0.25
NA
NA
NA
NA
NA
3.52
153-209
0.45-1.21
1.28-3.62
136-213
NA
NA
26
22
2
3,130
0.6
31.1
0.25
319
9.6
2.1
2.4
0.12
4,700
2.1
233
17.9
0.01
3.4
295
0.58
1.72
56.1
15.1
17.5
On-site
130
• 150
- 130
- 25.5
- 50.300
- 41.8
- 235
- 3.2
- 148,000
- 70.5
- 68.2
- 75.8
- 0.37
- 85,800
• 48.6
- 3.990
- 1,770
- 95.8
- 35.4
- 3,250
- 0.64
- 2.8
- 1,560
- 107
- 358
Background (e,f)
ND (409
ND (409
-1.200)
- 1,200)
110
ND(13
3,060 -
0.4 -
19.3 •
1.2 -
263-
3.5 •
1.9 -
2.1 -
0.1 -
1.230 -
4 -
279 •
18.1 -
0.02 -
4 -
830 -
• 1,500)
28.600
6.1
156
1.9
4.120
48.5
14.3
13.3
0.3
32,900
39.1
3,050
1,110
0.11
23.6
2,040
ND (0.49 - 0.97)
ND (1.5 -3.0)
84.9 -
4.4 •
13.3 •
247
59.7
93.6
See footnoted at end of table.
-------
19-Apr-94 newfpSS.WBI
Table 6-1 (Cont.)
SUMMARY OF CHEMICALS DETECTED IN SURFICIAL SOIL AND SEDIMENT: FLOODPLAIN
ECOLOGICAL ASSESSMENT
(Concentrations reported in ug/kg for organics. mg/kg (or inorganics)
' = Chemical of potential concern. See text for a description of procedures used to select chemicals of potential concern.
+ B Chemical of potential concern for plants. See text.
NA = Not applicable; chemical detected in every sample or non-detected samples had high detection limits
such that one-half of the detection limit exceeded the maximum detected value. (These values were excluded
from the data and summary. See text.)
ND = Not detected. (Detection limits In parentheses.) .
NC = Not calculated; only one sample available for mean calculation.
(a) Values presented for DDT and metabolites are the sum of values for the o,p'- and p.p'- Isomers.
(b) The number of samples In which the chemical was detected divided by the total number of samples analyzed.
(c) The number of samples used to calculate the mean. This number may differ from the denominator of the frequency
of detection because non-detect samples with high detection limits were not included in the calculation of the mean.
(d) Values rounded to no more than three significant figures.
(e) Detection limits are only those for which one-half of the detection limit was less than the maximum detected value. See text.
(I) Background concentrations reported are for soil and sediment collected from the Stimpson Wildlife Sanctuary,
located up-river from the CIBA-GEIGY Mclntosh plant.
(g) Eliminated as a chemical of potential concern based on concentration-toxicity screening. See text and Appendix B.
(h) Eliminated as a chemical of potential concern because chemical was detected In 5% or less of samples.
(I) Eliminated as a chemical of potential concern because concentrations were not statistically higher than
background.
-------
19-Apr-94 hewobss.WBI
Table 6-2
SUMMARY OF CHEMICALS DETECTED IN SEDIMENT: OLIN BASIN
ECOLOGICAL ASSESSMENT
(Concentrations reported In ug/kg lor organlcs, mg/kg lor Inorganics)
Chemical (a)
ORGANICS:
Insecticides:
Aldrin (g)
alpha-BHC (h)
beta-BHC (h)
delta-BHC (h)
gamma-BHC (g)
ODD (h)
DDE (h)
DDT (h)
Endosullan 1 (g)
Endosultan II (g)
Heptachlor Epoxlde (g)
Hexachlorobenzene (h)
Other Organic Chemicals:
Chlorobenzene (h)
1,3-Dlchlorobenzene (h)
1 ,4-Dlchlorobenzene (h)
INORGANICS:
Aluminum (i)
Antimony
Arsenic (I)
Barium (I)
Beryllium (I)
Calcium (I)
Chromium (I)
Cobalt (I)
Copper
Cyanide
Iron (I)
Lead (I)
Magnesium (I)
Manganese (1)
Frequency of
Detection (b)
1 / 19
2 / 19
3 / 19
2 / 19
1 / 18
19 / 19
19 / 19
19 / 19
1 / 18
1 / 18
1/19
8 / 19
19/19
4 / 19
4/18
1 / 1
4 / 6
19 / 19
1 / 1
2 / 19
.1/1
19 / 19
1 / 1
IB / 19
5/ 19
1 / 1
. 19 / 19
1/1
1 / 1
Mean
Sample
Slze(c)
18
17
18
19
18
19
19
19
18
18
17
19
19
9
9
1
6
19
1
19
1
19
1
19
19 '
1
19
1
1
Range of Detected Concentrations (d)
Mean
Concentration (d)
5.32
4.75
6.06
27.2
5.36
573
608
476
36.2
10.3
3.87
5.370
161
345
394
NC
14.9
7.1
NC
1.05
NC
32.8
NC
2S.5
0.575
NC
22.9
NC
NC
Range ol
Detection Umlls (d.e)
3.5 - 35 .
2.3 • 24
2.3 - 35
2.3-130
3.5 - 35
NA
NA '
NA
3.5 • 220
6.9 - 67
3-9.2
670-1.700
NA
670 - 980
670 - 980
NA
6.20-11.9
NA
NA
0.23-2.70
NA
NA
NA
3.30
0.09-1.20
NA
NA
NA
NA
On-slte
30
10
10 - 20
50 - 170
30
73 - 1800
70 - 1400
34 - 4000
110 .
50 .
20
500 - 40000
10 - 1000
40 - 590
190 - 510
12100
10.1 - 24.6
2.1 - 16.1
55.7
0.9 - 3.7
1660
6.1 - 52.1
10.4
12.5 • 57.5
0.78 - 1.5
20500
5.9 - 44.2
1090
290
Background (e.l)
'NO (2.3 -5.1)
ND (2.3 -5.1).
ND (2.3 -5.1)
ND (2.3 -5.1)
ND (2.3 -5.1)
NO (40.4 - 93.9)
ND (25.4 - 56.9)
ND (25.4 - 56.9)
ND (2.3-5.1)
ND (4.4 -9.4)
ND (2.3 -5.1)
ND (409 - 1 ,200)
ND (21 - 49)
ND (409 -1.200)
ND (4.09 -1201)
3,060 - 28,600
ND (4.21 -8.51)
0.4 - 6.1
19.3 - 156
1.2. - 1.9
263 - 4.120
3.5 • 48.5
1.9 - 14.3
2.1 - 13.3 ' '
0.1 - 0.3
1,230 - 32,900
4 - 39.1
279 • 3,050
18.1 - 1,110
See footnotes at end ol table.
-------
19-Apr-94 newobss.WBI
N>
U)
Table 6-2 (Cont.)
SUMMARY OF CHEMICALS DETECTED IN SEDIMENT: OLIN BASIN
ECOLOGICAL ASSESSMENT
(Concentrations reported In ug/kg lor organlcs, mg/kg (or Inorganics).
Frequency of
.Chemical (a)
* Mercury
Nickel (1)
Potassium (1)
* Sodium
Vanadium (1)
• Zinc
Detection (b)
19 /
1 /
1 /
1 /
1 /
19 /
19
19
19
1 -
1
19
Mean
Sample
Size (c)
19
14
1
1
1
19
Ranqe ol Detected Concentrations (d)
Mean
Concentration (d)
43.8
8.43
NC
NC
NC
132
Range ol
Detection Limits (d.e)
NA
2.50 - 27.90
NA
NA
NA
NA
On-site
3 - 290
10.9
1170
1030
32.9
8 - 227
Background (e,l)
0.02
4
830
84.9
4.4
13.3
- 0.11 -
- 23.6
• 2.040
- 247
- 59.7
- 93.6
* - Chemical ot potential concern. See text lor a description ol procedures used to select chemicals ol potential concern.
NA = Not applicable; chemical detected In every sample or non-detected samples had high detection limits such that one-hall
of the detection limit exceeded the maximum detected value. (These values were excluded from the data and summary. See text.)
NO » Not detected. (Detection limits In parentheses.)
NC « Not calculated; only one sample available (or mean calculation.
(a) Values presented lor DDT and metabolites are the sum ol values lor the o.p'- and p.p'- Isomers.
(b) The number ol samples In which the chemical was detected divided by (he total number ol samples analyzed.
(c) The number ol samples used to calculate the mean. This number may differ Irom the denominator ol the frequency
ol detection because non-detect samples with high detection limits were not Included In the calculation ol the mean.
(d) Values rounded to no more than three significant figures.
(e) Detection limits are only those lor which one-half of the detection limit was less than the maximum delected value. See text.
(I) Background concentrations reported are lor soil and sediment collected from the Stlmpson Wildlife Sanctuary,
located up-river from the CIBA-QEIQY Mclntosh plant.
(g) Eliminated as a chemical of potential concern because chemical was detected In approximately 5% or less of samples.
(h) Eliminated as a chemical ol potential concern based on concentratlon-toxlclty screening. See text and Appendix B.
(I) Eliminated as a chemical of potential concern because concentrations were not statistically higher than
background; or, II a statistical evaluation was not possible, the detected concentration was below the mean
concentration reported lor the CIBA-GEIGY lloodplaln.
-------
Herbicides were the most frequently detected organic chemicals, and
were present in over 70% of the floodplain samples at concentrations
between 0.02 and 390 ug/L. Ametryn, atrazine, prometryn, and simazine
were detected in 50% to 71% of all samples, whereas the remaining
herbicides were detected in 35% or less of all samples. Highest
surface concentrations of many of these -chemicals were detected at
location A3, which is a shallow groundwater sample that was collected
because no surface water was available at this location.
DDTR was detected in 42% or less of the samples. Highest surface
water concentrations of DDD and DDE were detected at Dl, located in
the cypress swamp adjacent to the Ciba-Geigy property at the same
location as the highest detected sediment concentration for these two
chemicals. DDT, however, was not detected in the surface water at
this location although it was present in the sediment. A3 was the
only sample location in which DDT was present in the surface water
(shallow groundwater sample).
Chromium, cobalt, copper, cyanide, and nickel were present in
floodplain surface water samples above background concentrations. The
maximum detected concentration for each of these chemicals occurred in
the shallow ground water sample collected at A3.
Table 6-4 presents a summary of the chemicals selected for evaluation
in the ecological assessment. The primary chemicals of potential
concern are DDT and its metabolites DDE and DDD collectively referred
to as DDTR. These chemicals were detected at relatively high
frequencies in soil/sediment and biota. In addition, DDTR is a
foodchain accumulating ecologically toxic contaminant. Concentrations
of DDT-related compounds and other chemicals were generally highest in
the former effluent ditch, in the drainage way that flows west from
the floodplain, or near the bluffline. Additional chemicals of
concern are ametryn, atrazine, butylbenzylphthalate, prometon,
prometryn, propazine, simetryn, terbuthylazine, terbutryn, tolban,
chromium, copper, cyanide, nickel, and mercury.
All of the herbicides detected in surface water and soil/sediment were
included as chemicals of potential concern for plants in these media
because of their known toxicity to at least some plant species. With
the exception of atrazine and simazine in soil/sediment, the
herbicides were not selected as chemicals of potential concern for
other potential ecological receptors based on a comparison of toxicity
concentrations found in background ecological receptors. Although
there were fewer soil samples analyzed for these chemicals than for
DDTR, there is still a general trend of higher concentrations in the
drainage ways or areas of lower elevation and near the bluffline.
Butylbenzylphthalate was included as a COPC for soil/sediment although
it was detected in concentrations bordering on the detection limit and
could potentially be a laboratory artifact.
24
-------
1B-Apr-94 SUMFLOD2.wb1
Table 6-3
SUMMARY OF CHEMICALS DETECTED IN FLOODPLAIN STUDY AREA SURFACE WATER (a)
HUMAN HEALTH ASSESSMENT
(Concentrations reported In ug/L)
Chemical
ORGANICS:
* Ametryn
* Atrazine
• alpha-BHC
• beta-BHC
delta-BHC (j)
Chlorobenzilate (h)
Chloroform (h)
Chloropropylate (h)
• ODD (b)
• DDE (b)
• DDT(b)
Endosullan 1 (h)
Metolachlor (h)
Prometon (h)
• Prometryn
* Propazine
* Simazine
Simetryn 0)
* Terbuthylazine
* Terbutryn
tolban (h)
Trichloroethene (h)
INORGANICS:
Aluminum (g)
Barium (g)
Beryllium (g)
Calcium (g)
Chromium (h)
Cobalt G)
Copper (h)
Frequency of
Detection (c)
10 / 14
8 / 14
5 / 14
5 / 14
1 / 14
2 / 14
2 / 14
1 / 14
6 1 14
2 / 14
1 / 14
1 / 14
1 / 14
3 / 14
9 / 14
5/14 .
7/14
3 / 14
3/14
5 / 14
1 / 14
1 / 14
9/14
14 / 14
1 / 14
14 / 14
4 / 14
4 / 14
6 / 14
Mean
Sample
Size (d)
14
14
14
14
12
11
14
11
14
14
14
11
13
14
14
14
14
14
14
14
11
1
14
14
14
14
14
14
14
Range of Detected Concentrations (e)
Mean
Concentration (e)
3.42
34.3
0.538
0.150
0.040
0.077
6.14
0.0677
0.644
0.333
0.225
0.0338
0.291
0.46
2.64
30.7
10.1
0.35
1.6
1.0
0.0118
NC
1.940
92.1
0.564
27,000
4.68
7.61
7.76
Range of
Detection Limits (e,i)
0.6-1.2
0.1
0.1
0.1
0.05 - 0.2
0.1 • 0.22
10
0.1-0.2
0.05 - 0.8
0.04 - 0.8
0.1 - 0.8
0.05 - 0.1
0.5
0.1
0.1
0.1
0.1
0.1 - 2.8
0.1
0.1
0.02 - 0.04
NA
273 - 345
NA
1
NA
5
5
4
Study Area
0.1 - 39
0.1 - 260
0.1 - 2.9
0.1 - 0.62
0.1
0.1 - 0.18
12 - 14
0.14
0.1 • 3.13
1.0 - 1.59
1.7
0.1
0.9
0.32 - 3.2
0.2 - 16
0.2 - 390
0.2 - 81
0.2 - 2.2
0.5 • 19
0.1 - 13
0.02
0.5
517 • 8,080
23 - 410
1.4
1,850 • 103,000
5.1 - 13.6
8.1 • 31
4.2 - 58.6
Background (f)
NO (0.06)
ND (0.08)
NO (0.05)
ND (0.05)
ND (0.05)
ND(0.11)
ND(10)
ND(0.11)
ND(0.14)
ND (0.15)
ND(0.16)
ND (0.05)
ND (0.48)
ND(0.13)
ND (0.08)
ND (0.07)
ND (0.14)
ND(0.14)
ND (0.06)
ND (0.12)
ND (0.02)
ND(10)
504 - 1,560
19.4 - 56.5
ND(1.0)
3,620 - 27,900
ND (5.0)
ND (5.0)
ND (4.0)
See footnotes on following page.
-------
18-Apr-94 SUMFLOD2.wb1
K)
Table 6-3 (Cont.)
SUMMARY OF CHEMICALS DETECTED IN FLOODPLAIN STUDY AREA SURFACE WATER (a)
HUMAN HEALTH ASSESSMENT
(Concentrations reported In ug/L)
Chemical
ORGANICS:
* Ametryn
• Atrazine
• alpha-BHC
• beta-BHC
delta-BHC (J)
Chlorobenzilate (h)
Chloroform (h)
Chloropropylate (h)
• ODD (b)
• DDE (b)
• DDT(b)
Endosullan 1 (h)
Metolachlor (h)
Prometon (h)
• Prometryn
* Propazine
• Simazine
Simetryn (j)
* Terbuthylazine
• Terbutryn
Tolban (h)
Trichloroethene (h)
INORGANICS:
Aluminum (g)
Barium (g)
Beryllium (g)
Calcium (g)
Chromium (h)
Cobalt G)
Copper (h)
Frequency of
Detection (c)
10 / 14
B / 14
5 / 14
5 1 14
1 / 14
2 / 14
2 / 14
1 / 14
6 / 14
2 / 14
1 / 14
1 / 14
1 / 14
3/14
9 / 14
5 / 14
7 / 14
3 / 14
3 / 14
S 1 14
1 / 14
1 / 14
9 / 14.
14 / 14
1 / 14
14 / 14
4 / 14
4 / 14
6 / 14
Mean
Sample
Size (d)
14
14
14
14
12
11
14
11
14
14
14
11
13
14
14
14
14
14
14
14
11
1
14
14
14
14
14
14
14
Range of Detected Concentrations (el .
Mean
Concentration (e)
3.42
34.3
0.538
0.150
0.040
0.077
6.14
0.0677
0.644
0.333
0.225
0.0338
0.291
0.46
2.64
30.7
10.1
0.35
1.6
1.0
0.0118
NC
1,940
92.1
0.564
27.000
4.68
7.61
7.76
Range of
Detection Limits (e,i)
0.6-1.2
0.1
0.1
0.1
0.05 - 0.2
0.1 - 0.22
10
0.1 - 0.2
0.05 - 0.8
0.04 - 0.8
0.1 - 0.8
0.05 - 0.1
0.5
0.1
0.1
0.1
0.1
0.1 - 2.8
0.1
0.1
0.02 • 0.04
NA
273 - 345
NA
1
NA
5
5
4
Study Area
0.1 • 39
0.1 - 260
0.1 - 2.9
0.1 - 0.62
0.1
0.1 - 0.18
12 • 14
0.14
0.1 • 3.13
1.0 - 1.59
1.7
0.1
0.9
0.32 - 3.2
0.2 • 16
0.2 • 390
0.2 - 81
0.2 • 2.2
0.5 • 19
0.1 • 13
0.02
0.5
517 - 8,080
23 • 410
1.4
1.850 - 103,000
5.1 - 13.6
8.1 - 31
4.2 - 5S.6
Background (0
ND (0.06)
NO (0.08)
ND (0.05)
ND (0.05)
ND (0.05)
ND(0.11)
ND(10)
ND(0.11)
ND(0.14)
ND(0.15)
ND(0.16)
ND (0.05)
ND (0.48)
ND(0.13)
ND (0.08)
ND (0.07)
ND (0.14)
ND (0.14)
ND (0.06)
ND (0.12)
ND (0.02)
ND (10)
504 - 1,560
19.4 • 56.5
ND(1.0)
3.620 - 27,900
ND (5.0)
ND (5.0)
ND (4.0)
See footnotes on following page.
-------
TABLE 6-4 SUMMARY OP CHEMICALS OF POTENTIAL CONCERN
CHEMICAL
Ametryn
Atrazine
Butylbenzylphthalate
DDD
DDE
DDT
Prometon
Prometryn
Propazine
Simazine
Simetryn
Terbuthylazine
Terbutryn
Tolban
SURFACE
SOIL/SEDIMENT
(P)
X(P)
X
X
X
X
(P)
(P)
(P)
X(P)
(P)
(P)
(P)
(P)
SURFACE WATER
(P)
X(P)
X
X
X
(P)
(P)
(P)
(P)
(P)
(P)
(P)
BIOTA
X
X
X
INORGANICS :
Chromium
Copper
Cyanide
Mercury
Nickel
X
X
X
X
X
X( raccoon only)
X
X = selected as a chemical of potential concern.
(P) = selected as a chemical of potential concern for plants.
6.2 HUMAN HEALTH RISK
Potential exposure pathways were reviewed and selected for
quantitative evaluation in the risk assessment. Because of the
drastic annual flooding conditions which limit development and
exposure, current and future land-use conditions were considered to be
similar. Exposure pathways selected for detailed evaluation are:
27
-------
• direct contact with contaminated sediments or dust particles,
• ingestion of venison,
• ingestion of animals or fish contaminated by animals
(including venison) feeding in the impacted area,
• dermal (skin) absorption of chemicals in surface
soil/sediment or surface water by a worker or trespasser.
The chemicals present most frequently and at the highest
concentrations in soil/sediment were DDT and its metabolites ODD and
DDE. In floodplain surface water, the more soluble triazine
herbicides were most frequently detected and were measured at the
highest concentrations. DDTR and hexachlorobenzene in fish tissue and
DDTR in crayfish were of most concern for the risk assessment.
EPA's target risk range for Superfund cleanups is 1 x 10"4 to 1 x 10"6.
A 1 x 10~4 range is equivalent to an increased chance of one additional
case of cancer in 10,000 individuals as a result of this level of
exposure to the contaminants at the site. A 1 x 10~6 range is
equivalent to an increased chance of one additional case of cancer in
1,000,000 individuals as a result of this level of exposure to the
contaminants at the site. Also, the concentrations of non-
carcinogenic chemicals must have hazard indices less than 1.0. All of
the upperbound excess lifetime cancer risks were already either lower
than USEPAs benchmark of 1x1O"6, or were within the acceptable risk
range of IxlO"4 to IxlO"6 as long as groundwater is not used for
drinking or bathing. All hazard indices were less than 1.0 which
indicates that adverse noncarcinogenic effects are unlikely to occur.
Table 6-5 provides a summary of RME risk estimates cancer risk due to
all chemicals for human health assessments using current land-use,
conditions. Table 6-6 provides a summary of RME risk estimates
noncancer risk due to all chemicals for human health assessments using
current land-use conditions.
6.3 ECOLOGICAL RISK
Potential risk to ecological receptors was characterized using both
quantitative and qualitative methods. Quantitative risk estimates,
derived by comparing estimates of exposure in selected receptors to
no-effect levels, were used to evaluate drinking water and dietary
exposure in birds and mammals. Qualitative evaluations were made for
all receptors based on bioassay results, tissue residues, and
published toxicity data.
28
-------
April 20, 1994/CUMRISK.TBL
Table 6-5
SUMMARY OF RME RISK ESTIMATES
CANCER RISK DUE TO ALL CHEMICALS
HUMAN HEALTH ASSESSMENTS
CURRENT LAND-USE CONDITIIONS
Incidental Ingestion of
Surface Soil/Sediment (a)
Incidental Ingestion of
Olin Basin Sediment
Dermal Contact with
Surface Soil/Sediment (a)
Dermal Contact with Olin
Basin Sediment
Dermal Contact with
Surface Water (b)
Ingestion of Venison
Ingestion of Olin Basin
Fish
Ingestion of Crayfish
Floodplain
Trespassers
1E-7
5E-8
7E-8
Olin Basin
Trespassers
1E-7
5E-8
Adult
Workers
4E-7
2E-7
8E-7
Hunters
2E-8
Anglers
4E-5 (c)
Floodplain
Crayfish
Consumers
9E-«
See footnotes on following page.
29
-------
April 20, 1994/CUMRISK.TBL
Table 6-6
SUMMARY OF RME RISK ESTIMATES
NONCANCER RISK DUE TO ALL CHEMICALS
HUMAN HEALTH ASSESSMENTS
CURRENT LAND-USE CONDITIONS
Incidental Ingestion of
Surface Soil/Sediment (a)
Incidental Ingestion or
Olin Basin Sediment
Dermal Contact with
Surface Soil/Sediment (a)
Dermal Contact with
Olin Basin Sediment
Dermal Contact with
Surface Water (b)
Dermal Contact with Olin
Basin Surface Water
Ingestion of Venison
Ingestion of Olin Basin
Fish
Ingestion of Crayfish
Floodplain
Trespassers
<1 (7E-4)
-------
April 20, 1994/CUMRJSK.TBL
Table 6-7
SUMMARY OF RME RISK ESTIMATES
HUMAN HEALTH ASSESSMENT
FUTURE LAND-USE CONDITIONS
Incidental Digestion of
Olin Basin Sediment
Dermal Contact with
Olin Basin Sediment
Dermal Contact with
Olin Basin Surface Water
Ingcstion of
Olin Basin Fish
Cancer Risk Due to All
Chemicals
Adult
Trespassers
2E-7
7E-8
Angclers
6E-5
Noncancer Risk Due to All
Chemicals
Adult
Trespassers
-------
6.3.1 Sampling Methodology
Plants (Saururus cernuus)
Representative samples of the nodding lizard's tail (S. cernuus), a
perennial floodplain plant, were obtained along Transects A, B, and C
and comparable floodplain areas of the background site. The soil was
loosened around the base of the plant so that a portion of the rhizome
could be easily pulled from the ground. Composite, whole specimen
samples (subsurface and aerial plant sections) were obtained for
chemical analysis.
Crayfish (Procambarus acutus)
A variety of techniques were used to obtain sufficient crayfish for
composite sample analysis. Seines, crayfish drags, crayfish traps,
and burrow excavation were employed during sample collection. In
general, crayfish were easier to obtain in standing water areas near
Transects B and C. Crayfish were obtained from these areas using a
crayfish drag or seines. Crayfish drags or seines were ineffective
for sample collection at the background site. Background crayfish
samples were collected using baited traps and by burrow excavation.
Crayfish samples were matched for species and to the extent possible,
specimen size.
Fish
Largemouth bass (Micropterus salmoides) and channel catfish (Ictalurus
punctattus) were obtained using traditional fishing techniques
(angling and baited trot lines). Artificial lures were used to catch
bass while catfish were caught using catalpa worms as bait. Fish were
placed on dry ice in a decontaminated ice chest following sample
collection. In most cases, fish were submitted to the analytical
laboratory as single, whole organism samples; however, two channel
catfish samples from the background area required a composite of two
fish to achieve adequate sample weight.
Amphibians (Bufo terrestris)
Southern toads (B. terrestris) were caught by hand from Transects A,
B, and C and comparable floodplain areas of the background site.
Composite samples were required to provide adequate sample weight for
chemical analysis.
Reptiles (Acrkistrodon yiscivorus)
Cottonmouth snakes (A. piscivorus) were collected using reptile snares
at Transects A, B, and C and comparable floodplain areas of the
background site. Snakes were killed by a blow behind the head with
the blunt edge of a machete. Snakes were submitted to the analytical
laboratory as single, whole animal samples.
32
-------
Small Mammals
The small mammal collection was abandoned due to the inability to
capture rats or mice in the floodplain areas of either the Ciba-Geigy
Corporation property or the background site during approximately 12
days of collection effort (40-60 snap traps set per night, 660 total
trap-nights). The inability to capture small mammals will not have a
major impact on the overall ecological study results.
Large Mammals (Procvon Jotor)
Live traps were ineffective for raccoon collection. All specimens
were shot in the head using a scoped .22 caliber rifle using short rim
fire ammunition. Raccoons were collected in wooded areas near
sampling Transects A, B, and C, and in similar habitat areas of the
background site.
S..3.2 Results Of Analyses
Plant (Saururus cernuus)
Table 6-8 presents the reported values for target analytes in plant
tissues. Five of the seven heavy metal analytes were detected in the
plant tissues. In general the levels of arsenic, cadmium, chromium,
and mercury are similar in the study area plants and in background.
The highest concentration of nickel (438 mg/kg) was reported from
sample PL-BG2.
Among the target pesticides only the DDT group compounds were found
and these were at levels below 0.01 mg/kg. All isomers of the DDT
group were found in specimens collected at Transect A, and two isomers
(4,4'-DDD and 2,4'-DDE ) were found in all samples including those
collected in the background locations. 2,4'-DDE was found in plants
at all transects in the study area at comparable levels (0.003 to
0.004 mg/kg), but not in background. The 4,4'- and 2,4' isomers of
DDT were found only in plants collected at Transect A (PL-A). Total
residues of all DDT group isomers, or DDTR, ranges from 0.0117 to
0.0293 mg/kg in study area plants and 0.0040 to 0.0094 mg/kg in the
background samples. No correlation was apparent between DDTR
concentrations in plants and soils collected from the same general
area in the floodplain. Plants collected from Transects B and G had
similar DDTR concentrations. However Transect B soils from this
location (B4) contained approximately 0.5 mg/kg DDTR. While DDT group
compounds were not detected in any Transect C soil samples.
Crayfish (Procambarus acutus)
The results of tissue analyses are presented in Table 6-9. All heavy
metals were detected in crayfish tissue. Selenium was detected only
in the three background samples at levels which range from 0.00017 to
0.00021 mg/kg. There is no apparent elevation of heavy metals in
crayfish collected in the study area although there appears to be a
marginal elevation of arsenic, nickel and zinc in some samples
33
-------
collected in the background area. Similar concentrations of inorganic
analytes were measured in crayfish collected near Transects B and C.
All of the DDT group compounds were found in crayfish tissues with
4,4'-DDD, 4,4'-DDE and 2,4'-DDE occurring in all samples including
background; 2,4'-DDD was found only in samples taken from the central
drainage (CY-A and CY-B) while 2,4'-DDT was detected only in sample
CY-C and in background sample CY-BG1. 4,4'-DDT was detected in the
three study areas samples but not in background. The average DDTR is
2.2 mg/kg in the study area crayfish and 0.047 mg/kg in background
samples. No correlation was observed between concentrations of DDTR
in crayfish and concentrations in sediment collected from the central
floodplain drainage (B3, C3).
Fish
Larqemouth Bass (Micropterus salmoides)
The results from analyses of whole body samples of largemouth bass are
presented in Table 6-10. All heavy metals except cadmium were
detected in fish tissues. Selenium was detected in four of the six
samples taken from Olin Basin which yielded values from 0.1 to 0.3
mg/kg. Chromium, mercury and zinc were detected in all samples.
Chromium levels were highest in fish from Boykin Pond with an average
concentration of 0.44 mg/kg compared to 0.39 and 0.23 mg/kg in the
background area and Olin Basin respectively. The highest average
mercury concentration was obtained in fish from Boykin Pond (0.68
mg/kg) but the highest concentration (0.93. mg/kg) was reported for
sample LB-D3 from Olin Basin (average 0.58 mg/kg). The average
concentration of mercury obtained from background samples was 0.23
mg/kg. No correlation was apparent between tissue concentrations of
inorganic analytes in largemouth bass and concentrations present in
surface water or sediment.
34
-------
TABLE 6-8
TISSUE ANALYSES
PLANTS
Analytes
INORGANICS
(nig/ kg)
Arsenic
Cadmium
Chromium
Mercury
Nickel
Selenium
Zinc
ORGANICS
(mg/kg)
4,4' -DDT
4,4' -DDD
4,4' -DDE
2,4' -DDT
2,4' -DDD
2,4' -DDE
Tolban®
PL -A
ND
ND
0.23
0.010
0.34 J
ND
ND
0.0070
J
0.0045
J
0.0079
0.0036
J
0.0036
0.0027
J
ND
PL-B
ND
ND
0.18
0.010
0.46 J
ND
ND
ND
ND
0.0058
ND
0.0023
0.0036
J
ND
PL-C
0.20 J
2.7
0.13
0.010
25.4 J
ND
ND
ND
ND
0.0044
ND
0.0066
0.0040
J
ND
PL-
BG1
0.70
J
ND
0.12
0.010
0.77
J
ND
ND
ND
ND
0.007
5
ND
0.001
9
ND
ND
PL-BG2
0.22 J
19.5
0.32
0.010
438 J
ND
ND
ND
ND
0.0025
ND
0.0015
ND
ND
PL-BG3
0.36 J
ND
0.18
0.010
i.. a
J
n
ND
ND
ND
0.0056
ND
0.0019
ND
NflJ
35
-------
Chlorobenzil
ate
Diazinon
% lipids
'ND
ND
0.55
ND
ND
0.47
ND
ND
0.82
ND
ND
0.77
ND
ND
0.86
ND
ND
0.69
J = approximate concentration
ND = not detected (below detection limit)
TABLE 6-9
TISSUE ANALYSES
CRAYFISH
Analytes
INORGANICS
(mg/kg)
Arsenic
Cadmium
Chromium
Mercury
Nickel
Selenium
Zinc
ORGANICS
(mg/kg)
4,4' -DDT
4,4' -ODD
4,4' -DDE
CY-A
0.19 J
0.080
J
0.35
0.030
0.53
ND
12.4 J
0.2639
0.4074
0.8467
CY-B
0.19 J
0.50 J
0.32
0.030
1.3
ND
12.0 J
0.0816
0.4971
0.7255
CY-C
0.17 J
0.18 J
0.37
0.020
1.1
ND
13.2 J
0.3230 J
0.3271 J
2.2625
CY-BG1
0.47 J
0.80
0.30
0.030
4.9 J
0.21 J
22.1 J
ND
0.0089
J
0.0609
CY-BG2
0.47 J
ND
0.38
0.050
0.33 J
0.19 J
19.7 J
ND
0.0032
J
0.0270
CY-BG3
0.28 J
ND
0.29
0 . 040
0.23 J
0.17 J
18.2 J
ND
0.0022
J
0.0163
36
-------
2,4' -DDT
2,4' -ODD
2,4' -DDE
To 1 ban®
Chlorobenzil
ate
Diazinon
% lipids
ND
0.0474
0.1287
ND
ND
ND
1.25
ND
0.0512
0.1271
ND
ND
ND
1.72
0.1230
ND
0.4976 J
ND
ND
ND
1.43
0.0073
J
ND
0.0080
J
ND
ND
ND
2.22
ND
ND
0.0053
J
ND
ND
ND
1.73
Hi
ND
0.0034
J
ND
ND
ND
1.71
J = approximate concentration
ND = not detected (below detection limit)
All DDT group compounds were detected in largemouth bass tissues
although 2,4'-DDT was found in only one (LD-D5) of the 12 samples
analyzed. 4,4' and 2,4-DDE were found in all samples including
background samples. The dominant isomer in all samples is 4,4'-DDE
which-accounts for 41 to 51% of the DDTR in Olin Basin 68 to 78% in
samples from Boykin Pond and 71 to 88.7% of the DDTR in the
background area.
The total for all isomers (DDTR) in the background area ranged from
0.074 to 0.455 mg/kg; Boykin pond samples ranged from 0.602 to
0.769 mg/kg while in Olin Basin samples range from 11.192 to 44.780
mg/kg. DDT group compounds, were not detected in surface water
collected from the background area, Boykin Pond, or Olin Basin.
DDTR concentrations in Boykin Pond and Olin Basin sediment were 0.6
and 4.2 mg/kg, respectively. DDT group compounds were not detected
in background area sediments.
Catfish
(Ictalurus punctatus)
Results from analysis of twelve, whole body catfish samples are
presented in Table 6-11. Chromium, mercury, nickel and zinc were
detected in all'samples. The data suggest an elevation in mercury
levels (less than 1 order of magnitude) in fish collected from Olin
Basin and Boykin Pond. Olin Basin has the highest overall average
concentration (0:33 mg/kg in Olin Basin, 0.16 mg/kg in Boykin Pond,
and 0.053 mg/kg in background) . Sediment concentrations of mercury
were also higher in Qlin Basin (D3, 28 mg/kg) as compared to Boykin
Pond (E3, 0.18 mg/kg^ and the background area (BG-2, - 0.07 mg/kg)
4,4'-DDD and 4,4'-DDE were the predominant isomers in fish tissues.
37
-------
These isomers were found in all fish samples, except Boykin Pond
sample CF-E1 which contained only 4,4'-DDD. In Olin Basin
specimens, 2,4'-DDD and 2,4'-DDE were seen in all samples. DDT
(4,4'- and 2,4'- isomers) was found only at low levels and only in
Olin Basin samples. The average DDTR in Olin Basin samples is
11.940 mg/kg, while in Boykin Pond and in background average DDTR
is 0.179 mg/kg and 0.108 mg/kg respectively. DDT group compound,
were not detected in surface water collected from the background
area, Boykin Pond, or Olin Basin. DDTR concentrations in Boykin
Pond and Olin Basin sediment were 0.6 and 4.2 mg/kg, respectively.
DDT group compounds were not detected in background area sediments.
Amphibians (Bufo terrestris) • .
The results from analyses of whole body samples of southern toads
are represented in Table 6-12. Six heavy metal analytes were
detected in all toad samples. Cadmium was detected in only one
sample (TD-BG1) in the background area. The levels measured for
these six metals are similar in study area toads and background
samples. No correlation was observed between concentrations of
inorganics in toad sample and soils or sediments collected from
similar areas of floodplain.
38
-------
Table 6-10
TISSUE ANALYSES
BASS
Analytes
INORGANICS
(mg/kg)
Arsenic
Cadmium
Chromium
Mercury
Nickel
Selenium
Zinc
ORGANICS
(mg/kg)
4,4'-DDT
4,4'-DDD
4,4'-DDE
2,4'-DDT
2,4'-DDD
2.4'-DDE
Tolban®
Chlorobenzilate
Diazinon
% lipids
LB-D1
ND
ND
0.21
0.43
0.21
ND
8.7 J
0.3696
3.1588
4.5878
ND
1 .2470
1.8285
ND
ND
ND
2.72
LB-D2
ND
.ND
0.17
0.47
0.24
ND
8.3 J
-
0.8011
5.8902
9.1089
ND
1.7574
4.0629
0.0426
ND
ND
11.20
LB-D3
0.60 J
ND
0.24
0.93
. 0.22
0.1 7 J
8.9 J
1.0257
7.1781
15.4026
ND
1.8912
5.1987
ND
ND
ND
5.58
LB-D4
0.1 3 J
ND
0.31
0.66
0.20
0.1 9 J
10.6 J
1.2155J
5.9861 J
12.5063
ND
2.2388 J
2.3804
ND
ND
ND
5.93
LB-D5
0.50 UJ
ND
0.20
0.76
0.12
ND
7.5 J
1.2694
13.1521
21.0915
0.9431
2.6016
5.7226
0.054.46
ND
ND
7.17
LB-D6
0.20 J
ND
0.25
0.24
ND
0.32 J
9.9 J
2.8260
12.7833
18.7371
ND
3.6588 J
6.2533
ND
ND
ND
9.23
LB-E1
0.050 J
ND
0.49
0.83
0.14
ND
10.7J
0.01 46 J
0.0944 J
0.4099
ND
0.01 63 J
0.0675
ND
ND
ND
4.97
LB-E2
0.050 J
ND
0.38
0.72
ND
ND
9.5 J
0.0257 J
0.1 589 J
0.4730
ND
ND
0.0312
ND
ND
ND
3.34
LB-E3
ND
ND
0.45
0.51
ND
ND
11.2J
0.0739 J
0.0786 J
0.5928
ND
ND
0.0234
ND
ND
ND
0.82
LB-
BG1
ND
ND
0.42
0.22
0.13
ND
10.6J
ND
ND
0.0663
ND
ND
0.0085
ND
ND
ND
4.40
LB-
BG2
ND
ND
0.41
0.27
ND
ND
12.4J
ND
ND
0.1686
ND
ND
0.0286
ND
ND
ND
4.91
LB-
BG3
OND
ND
0.36
0.20
ND
ND
9.1 J
ND
0.1159
0.3273
ND
ND
0.0115
ND
ND
ND
6.70
J - approximate concentration
ND - not detected (below detection limit)
Tolban® was detected in only two of the 12 fish analyzed. Measured values were 0.043 and 0.055 mg/kg in samples LB-D2 and LB-D5 respectively.
-------
TISSUE ANALYSES
CATFISH
Analytes
INORGANICS
(mg/kq)
vrsenic
Cadmium
Chromium
Mercury
Jickel
>elenium
line
ORGANICS
(mg/kq)
i,4'-DDT
•,4'-DDD
•,4'-DDE
:,4'-DDT
!,4'-DDD
!,4'-DDE
'olban®
)hlorobenzilate
)iazinon
'o lipids
CF-D1
••
ND
ND
0.13
0.070
0.27
ND
9.1 J
ND
0.3695
0.2691
0.0489
0.1742
0.3033
ND
ND
ND
8.09
CF-D2
ND
"ND
0.19
0.33
0.25
ND
9.0 J
0.1043
0.2066
0.3855
ND
0.1053
0.1953
ND
ND
ND
5.56
CF-D3
ND
ND
0.21
0.33
0.29
ND
10.9J
0.1547
1.8355
4.2839
ND
0.4084
1.3972
ND
ND
ND
3.88
CF-D4
0.1 OJ
ND
0.39
0.51
0.43
ND
11.5J
0.0658
1.3403
2.8072
ND
0.2686
0.9882
ND
ND
ND
3.49
PF-D5
ND
ND
0.17
0.26
0.28
ND
10.9J
ND
13.0471
16.9618
ND
4.0325
7.6505
0.0391
ND
ND
6.87
CF-D6
ND
ND
0.36
0.49
0.50
ND
10.7J
0.5291
3.7930
6.0392
ND
0.9002
2.9768
ND
ND
ND
1.78
CF-E1
ND
ND
0.24
0.13
0.24
0.18J
11.9J
ND
0.0525
ND
ND
ND
ND
ND
ND
ND
6.36
CF-E2
ND
ND
0.31
0.15
0.15
0.1 8 J
11.6J
ND
0.0476 J
0.1982
ND
0.020 J
0.0426
ND
ND
ND
3.54
CF-E3
ND
ND
0.22
0.20
0.23
0.20 J
10.7J
ND
0.0204 J
0.1250
ND
0.01 13 J
0.0211
ND
ND
ND
2.76
CF-BG1
ND
ND
0.39
0.060
4.9
0.1 9 J
25.8 J
ND
0.0195
0.0580
ND
ND
ND
ND
ND
ND
2.54
CF-BG2
0.050 J
ND
0.39
0.060
0.13
0.1 7 J
16.9J
ND
0.0387
0.1054
ND
ND
ND
ND
ND
ND
3.54
CF-
BG3
ND
ND
0.49
0.040
0.21
ND
19.0J
ND
0.0175
0.0754
ND
ND
11.20
ND
ND
ND
2.76
J • approximate concentration
ND - not detected (below detection limit)
-------
TABLE 6-12
TISSUE ANALYSES
TOAD
Analytes
INORGANICS
(mg/kg)
Arsenic
Cadmium
Chromium
Mercury
Nickel
Selenium
Zinc
ORGANICS
(mg/kg)
4,4'-DDT
4,4'-DDD
4,4'-DDE
2,4'-DDT
2,4'-DDD
2,4'-DDE
Tolban®
Chlorobenzilate
Diazinon
% lipids
TD-A
0.070 J
ND
0.47
0.070
0.12
0.19
30.6 J
1.5374
0.1414
3.6203
ND
ND
0.0651
0.0179
ND
ND
2.88
TD-B
0.10 J
ND
0.46
0.060
0.48
0.18
15.8 J
0.0828
0.0342
2.7089
ND
ND
0.0758
ND
ND
ND
1.98
TD-C
0.090 J
ND
0.37
0.060
0.12
0.19
18.9 J
0.0531 J
ND
0.4817 J
ND
ND
ND
ND
ND
ND
2.64
TD-BG1
0.060 J
0.040 J
0.39
0.060
0.57
0.24 J
18.2 J
ND
0.0064
ND
ND
ND
ND
ND
0.0345
ND
1.38
TD-BG2
0.050 J
ND
0.36
0.060
0.13
0.24 J
18.3 J
ND
ND
0.0031
ND
ND
ND
ND
ND
ND
1.51
TD-BG3
0.070 J
ND
0.39
0.070
1.6
0.26
19.5 J
ND
ND
0.0032
ND
ND
ND
ND
ND
ND
1.34
J = approximate concentration
ND = not detected (below detection limit)
41
-------
The predominant DDT group compounds detected in study area toads
are 4,4'-DDT and 4,4'-DDE which together account for 96 to 100%
of the total body burdens. The concentrations of these isomers
range from approximately 0.482 mg/kg to 3.62 mg/kg for 4,4'-DDE
and 0.053 mg/kg to 1.537 mg/kg for 4,4'-DDT. 4,4'-ODD and 4,4'-
DDE were detected in toad samples from the background site.
Tolban® was detected in one study area sample (TD-A) and
chlorobenzilate was detected in one of three background samples.
DDTR concentrations in toads were compared to concentrations in
soil or sediment collected from similar locations. Toad samples
collected near Transects A, B, and C contained DDTR
concentrations of 5.4, 2.9 and 0.5 mg/kg, respectively. Soil or
sediment sampled near these toad collection locations contained
1.3 (A4), 9.3 (B3), and 0.02 mg/kg (F7) of DDTR.
Reptiles (Agkistrodon piscivorus)
Table 6-13 presents the results from whole body analysis of snake
samples. There is no apparent elevation of heavy metals in the
reptile tissues in the study area. Cadmium was not detected in
any of the samples; the remaining heavy metals were detected in
all samples at comparable levels.
Two isomers of the DDT group, 4,4'-DDE and 2,4'- DDT were
detected in all samples from the study area and from the
background area. The dominant residue is 4,4'-DDE which
constitutes 97.6 to 98.5% of the total body burden in the study
area and 78.5 to 89.6% of the total body burden in the background
samples.
DDTR ranges from 2.990 mg/kg to 27.817 mg/kg in the study area
samples and 0.057 mg/kg to 0.370 mg/kg in background samples. ..
Raccoon (Procvon lotor)
Fat
The results from analysis of fatty tissues taken from raccoons
are presented in Table 6-14. Three samples were analyzed from
the study area and three from background. Four inorganic
analytes, chromium, mercury, nickel, and zinc were found in study
area and background area fat specimens. The reported levels for
heavy metals are similar in the study area and background
animals.
42
-------
Table 6-13
TISSUE ANALYSES
REPTILE
Analytes
INORGANICS
(ma/kg)
Arsenic
Cadmium
Chromium^-
Mercury
Nickel
Selenium
Zinc
ORGANICS
(mg/kg)
4,4'-DDT
4.4'-DDD
4,4'-DDE
2.4'-DDT
2.4--DDD
2.4--DDE
Tolban®
Chlorobenzilate
Diazinon
% lipids
SN-A
0.1 5 J
ND
0.94
0.50
0.56 J
0.35 J
19.4J
ND
0.075 J
9.7000
0.1 300 J
0.01 22 J
0.0240 J
ND
ND
ND
1.26
SN-B
0.080 J
ND
0.53
0.41
0.20 J
0.33 J
16.8J
ND
ND
2.9398
0.0506 J
ND
ND
ND
ND
ND
2.07
SN-C
0.090 J
ND
0.62
0.74
0.28 J
0.42 J
20.7 J
ND
ND
27.3999
0.41 75 J
ND
0.0331 J
ND
ND
ND
2.62
SN-BG1
0.1 8 J
ND
0.63
0.46
0.34 J
0.25 J
21 .5 J
ND
ND
0.0449
0.01 23 J
ND
ND
ND
ND
ND
0.99
SN-BG2
0.090 J
ND
0.76
0.55
0.1 9 J
0.32 J
20.3 J
ND
0.0276 J
0.3161
0.0228 J
ND
0.0042 J
ND
ND
ND
2.00
SN-BG3
0.090 J
ND
0.57
0.50
0.21 J
0.44 J
16.3J
ND
ND
0.1238
0.01 43 J
ND
ND
ND
ND
ND
3.77
J = approximate^vicentration
ND - not detected (b^Bdetection limit)
-------
All DDT group compounds except 2,4'-DDT were found in study area
samples. 4,4'-ODD, 4,4'-DDE and 2,4'-DDE were found in
background fat samples. Average DDTR in the study area is 17.1
mg/kg, compared to 0.022 mg/kg in background. The predominant
isomer in raccoon fat is 4,4'-DDE which accounts for 73.5 to 99%
of the DDTR body burden in study area raccoons. No correlation
was observed between concentrations of DDTR in raccoon fat and
concentrations of DDTR in surface water and sediment collected
from similar transect locations. Also, no correlation was found
between DDTR concentrations in crayfish and DDTR concentrations
in raccoon fat from specimens collected from similar locations.
This lack of geographic correlation is probably due to the size
of the feeding range of the raccoon.
Muscle
Table 6-15 presents the data from analyses of muscle tissue of
raccoons. As with raccoon fat chromium, mercury and zinc were
found in all specimens. The data suggest a slight elevation of
mercury above background levels in study area samples.
Four of the DDT group compounds were found in study area samples.
Only 4,4'-DDE was found in all' three study area samples while 4,4'-
DDT, 4,4'-DDD, and 2,4'-DDE were each found in two study area samples
DDT group isomers were not detected in background samples of muscle
tissue. DDTR ranges from 0.059 mg/kg to 0.763 mg/kg.
Liver
Table 6-16 presents the data from analyses of liver tissue of
raccoons. Cadmium, chromium, mercury and zinc were measured in all
samples. The levels of metals in the study area samples are
comparable to those in the background samples with the possible
exception of mercury in one sample (RC-A) . The 4,4'-isomers of DDT,
DDD, and DDE were detected in study area raccoon liver samples. 4,4'-
DDE was also detected in one background sample. Chlorobenzilate was
detected in a single background raccoon liver sample (RC-BG3).
44
-------
Table 6-rl4
TISSUE ANALYSES
RACCOON FAT
Analytes
INORGANICS
(mg/kg)
Arsenic
Cadmium
Chromium
Mercury
Nickel
Selenium
Zinc
ORGANICS
(mg/kg)
4,4'-DDT
4,4'-DDD
4,4'-DDE
2,4'-DDT
2,4'-DDD
2,4'-DDE
Tolban®
Chlorobenzilate
Diazinon
% lipids
RC-A
NO
ND
0.64
0.1 9 J
0.30
ND
9.6 J
ND
0.0194
2.0175
ND
ND
ND
ND
ND
ND
66.97
RC-B
ND
ND
0.38
0.12 J
0.14
ND
5.1 J
1.1695J
1 .3602
22.4448
ND
ND
0.0846
ND
ND
ND
42.29
RC-C
ND
ND
0.27
0.01 OJ
0.15
ND
1.9J
2.0982
3.8260
17.8826
ND
0.1175
0.4058 J
ND
ND
ND
84.40
RC-BG1
ND
ND
0.11
0.19 J
ND
ND
36.8 J
ND
ND
0.0098
ND
ND
0.0135
ND
ND
ND
39.78
RC-BG2
ND
ND
0.17
0.28
0.17
ND
44.7 J
ND
0.0088
0.0354
ND
ND
ND
ND
ND
ND
97.08
RC-BG3
ND
ND
0.19
0.11
ND
ND
43.5 J
ND
ND
ND
ND
ND
ND
ND
ND
ND
38.82
J = approximate concentration
ND = not detected (below detection limit)
-------
Table 6-15
TISSUE ANALYSES
RACCOON MUSCLE
Analytes
INORGANICS
(mg/kg)
Arsenic
Cadmium
Chromium
Mercury
Nickel
Selenium
Zinc
ORGANICS
(mg/kg)
4,4'-DDT
4,4'-DDD
4,4'-DDE
2,4'-DDT
2,4'-DDD
2,4'-DDE
Tolban®
Chlorobenzilate
Diazinon
% lipids
RC-A
ND
NO
0.24
1.2
0.30
ND
40.7 J
0.0025 J
ND
0.0562
ND
ND
ND
ND
ND
ND
2.65
RC-B
ND
ND
0.11
0.35
ND
ND
28.9 J
0.031 5 J
0.0429
0.6826
ND
ND
0.0056
ND
ND
ND
2.13
RC-C
ND
ND
0.14
0.37
ND
ND
38.1 J
ND
0.0669
0.4286
ND
ND
0.0054
0.0026
ND
ND
3.06
RC-BG1
ND
ND
0.35
0.020
0.20
ND
2.7 J
ND
ND
ND
ND
ND
ND
ND
ND
ND
3.00
RC-BG2
ND
ND
0.11
0.020 J
0.39
ND
3.4 J
ND
ND
ND
ND
ND
ND
ND
ND
ND
2.39
RC-BG3
ND
0.11 J
0.14
0.21 J
ND
ND
28.1 J
ND
ND
ND
ND
ND
ND
ND
ND
ND
2.06
J " approximate concentration
ND = not detected (below detection limit)
-------
Table 6-16
TISSUE ANALYSES
RACCOON LIVER
Analytes
INORGANICS
(mg/kg)
Arsenic
Cadmium
Chromium
Mercury
Nickel
Selenium
Zinc
ORGANICS
(mg/kg)
4,4'-DDT
4,4'-DDD
4,4'-DDE
2,4'-DDT
2,4'-DDD
2,4'-DDE
Tolban®
Chlorobenzilate
Diazinon
% lipids
RC-A
ND
0.13 J
0.14
4.8
ND
ND
19.6J
ND
ND
0.1012
ND
ND
ND
ND
ND
ND
2.35
RC-B
ND
0.1 OJ
0.21
1.8
ND
ND
53.9 J
ND
0.1948
1 .8063
ND
ND
ND
ND
ND
ND
4.13
RC-C
ND
0.41 J
0.19
2.6
ND
ND
40.4 J
0.1532J
0.1677
0.5153
ND
ND
ND
ND
ND
ND
4.44
RC-BG1
ND
0.11 J
0.13
0.87
ND
ND
26.9 J
ND
ND
• ND
ND
ND
ND
ND
ND
ND
3.17
RC-BG2
ND
0.1 8 J
0.11
1.6
0.48
ND
25.6 J
ND
ND
ND
ND
ND
ND
ND
ND
ND
3.54
RC-BG3
ND
ND
0.11
0.010
0.13
ND
2.5 J
ND
ND
0.0154
ND
ND
ND
ND
0.01 30 J*
ND
3.59
J = approximate concentration
ND = not detected (below detection limit)
47
-------
6.3.3 Summary/Discussion
Correlation of tissue levels with concentrations in abiotic media
(water, sediments, soils) cannot be made, except perhaps in a
most general fashion with the existing data. Animal species
which have been exposed to sufficient concentrations of
bioaccumulative substances for a sufficient period may develop
higher tissue concentrations of these substances than the same
species exposed to lower concentrations for the same period or to
the same concentration for a shorter period.
Tissue concentrations of inorganic analytes in the target species
are comparable in specimens collected in the study area and in
the background area. The difference between the average
concentration of individual analytes in the study area specimens
and background area specimens is less than one order of magnitude
in all species with one exception. There is a discernable
elevation in mercury levels in catfish taken from Olin Basin
which average 0.33 mg/kg mercury (six samples) compared to
background where the average is 0.05 mg/kg (three samples) and
Boykin Pond with 0.16 mg/kg (three samples). In addition,
results from the data collected during the 1994 additional field
activities conducted in the Olin Basin indicate that maximum DDTR
concentrations are as high as 81 ppm.
In general, tissue samples collected in the study area contain
higher levels of DDT group compounds than did those collected in
background. Each of the six DDT group compounds was found in at
least one biotic sample in both the study area and in the
background area. 4,4'-isomers account for 86.6% (average % in
each sample) of the DDTR in the 60 samples which contained DDT
group compounds. 4,4'-DDE was found to be present at a higher
concentration than all other isomers in 57 of the 59 samples in
which 4,4-DDE was identified.
Table 6-17 presents a summary of chemicals detected in
terresterial biota. The summary tables present the frequency of
detection, the mean, the number of samples used to calculate the
mean, the range of detection limits, and the range of detection
concentrations.
Based on data in the RI Report, EPA's assessment indicates that
levels of DDTR measured in surface water at the Site may pose a
hazard to aquatic life. In addition, fish eating birds and
mammals, as well as insect eating birds appear to be at risk from
exposure to DDTR or related pesticides via food, water and
sediment ingestion.
48
-------
19-Apr-94 newlsssm.WB!
Table 6-17
SUMMARY OF CHEMICALS DETECTED IN TERRESTRIAL BIOTA
• ECOLOGICAL ASSESSMENT
(Concentrations reported In mg/kg tissue; organlcs as wet weight, Inorganics as dry weight, as reported by laboratory)
Frequency of
Chemical (a) Detection (b)
CRAYFISH
Organlcs:
• DDD
• DDE
• DDT
Inorganics:
Arsenic (h)
Cadmium (h)
Chromium (h)
Nickel (h)
Zinc (h)
Mercury (h)
PLANT
Organlcs:
• DDD
• DDE
• DDT
Inorganics:
Arsenic (h)
Cadmium (h)
Chromium (h)
Mercury (h)
Nickel (h)
RACCOON (FAT)
Organlcs:
• ODD
• DDE
• DDT
Inorganics:
* Chromium
Mercury (h)
Nickel (h)
Zinc (h)
3 /
3 /
3 /
3 /
3 /
31
3 I
31
31
31
3 1
1 /
1 /
1 /
31
31
3 I
31
31
3 1
31
31
31
3 /
3
3
3
3
3
3
3
3
3 '
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Mean
Sample
Size (c)
3
3
"3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
.3
3
3
3
Range of Detected Concentrations (d)
Mean
Concentration (d.e)
0.444
1.53
0.267
0.183
0.103
0.347
0.977
12.5
0.0267
0.00621
0.00945
0.00409
0.0833
0.913
0.18
0.01
8.73
1.78
14.3
1.13
0.43
0.107
0.197
5.53
Range of
Detection Umlts (d.f)
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
0.00071 - 0.00096 •
.05
0.04
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
On-sRe
0.328 -
0.853 •
0.082 -
0.17 -
0.05 -
. 0.32 -
0.53 •
12 -
0.02 -
0.00271 -
.0.00839 -
0.548
2.76
0.453 .
0.19
0.18
0.37
1.3
13.2
0.03
0.00814
0.0106
0.0106
0.2
2.7
0.13 •
0.01
0.34 -
0.02 -
2.02 -
0.0668 -
0.27 -
0.01 •
0.14 -
1.9 -
Background (f.g)
0.0025 -
0.0197 •
0.0092
0.0689
0.0076
0.3 -
0.1
0.3 -
0.2 -
18.2 -
0.03 -
0.0023 •
0.003 -
0.5
0.4
4.9 '
22.1
0.05
0.0027
0.008
0.018
0.1 -
0.4
19.5
0.23
25.4
3.94
23.5
2.11
0.64
0.19
0.3
9.6
0.1 -
0.01
0.8 -
0.01
0.0232 -
ND (0.0063 •
0.1 -
0.1 -
0.2
38.8 •
0.3
438
0.0374
0.020)
0.2
0.3
44.7
See lootnotes at end of table.
-------
19-Apr.94newtsssm.WB1
L/1
O
Table 6-17 (Cont.)
SUMMARY OF CHEMICALS DETECTED IN TERRESTRIAL BIOTA
ECOLOGICAL ASSESSMENT
(Concentrations reported In mg/kg tissue; organlcs In wet weight, Inorganics In dry weight, as reported by laboratory)
Frequency ol
Chemical (a) Detection (b)
RACCOON (LIVER!
Organlcs:
• DDD
• DDE
• DDT
Inorganics:
Cadmium (h)
* Chromium
• Mercury
Zlnc(h)
RACCOON (MUSCLE)
Organlcs:
• DDD
• DDE
• DDT
Tolban (1)
Inorganics:
Chromium (h)
* Mercury
Nickel (h)
• Zinc
SNAKE
Organlcs:
• DDD
• DDE
• DDT
Inorganics:
Arsenic (h)
Chromium (h)
Mercury (h)
Nickel (h)
Selenium (h)
Zlnc(h)
21
31
1 /
3 /
3/
37
3 /.
2 /
3 /
2 /
1 /
3 /
3 /
1 /
31
1 /
37
3 /
3/
3 /
3 /
31
31
3 /
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Mean
Sample
Size (c)
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Range of Detected Concentrations (d)
Mean
Concentration (d.e)
0.123
0.809
0.0543
0.213
0.18
3.07
38
0.0373
0.393
0.0120
0.00217
0.163
0.64
0.14
35.9
0.0418
13.4
0.206
0.107
0.697
0.55
0.347
0.367
19
Range of
Detection Limits (d,f)
0.0018 - 0.0078
NA
0.00287 - 0.0048
NA
NA
NA
NA
0.00061 • 0.00159
NA
0.00096
0.00259 - 0.0052
NA
NA
0.12 • 0.12
NA
0.00061 • 0.048
NA
NA
NA
NA
NA
NA
NA
NA
On-slte
0.168 - 0.196 •
0.103 - 1.81
0.154
0.1 • 0.41
0.14 • 0.21
1.8 • 4.8
19.6 • 53.9
0.0432 • .0671
0.0564 • 0.688
0.00275 • .0319
0.00262
0.11 • 0.24
0.35 - 1.2
0.3
28.9 • 40.7
0.0781
2.94 - 27.4
0.0524 - 0.423
0.08 • 0.15
0.53 • 0.94
0.41 - 0.74
0.2 - 0.56
0.33 - 0.42
16.8 - 20.7
Background (f,g)
ND (0.00221 -0.01 10)
0.0159
ND (0.00167 • 0:00835)
0.1 - 0.2
0.11 - 0.13
0.01 • 1.6
2.5 • 26.9
ND (0.00221)
ND (0.00151)
ND (0.00167)
ND (0.0026 -0.01 3)
0.1 - 0.4
0.01 • 0.2
0.2 • 0.4
2.7 • 28.1
0.0279
0.0464 • 0.320
0.0134 - 0.0231
0.1 - 0.2
0.6 - 0.8
0.5 - 0.6
0.2 - 0.3
0.3 - 0.4
16.3 - 21.5
See lootnotes at end ol table.
-------
19-Apt-94 newtsssm.WBI
Table 6-17 (Cont.)
SUMMARY OF CHEMICALS DETECTED IN TERRESTRIAL BIOTA
ECOLOGICAL ASSESSMENT
(Concentrations reported In mg/kg tissue; organlcs In wet weight, Inorganics In dry weight, as reported by laboratory)
Chemical (a)
Frequency of
Detection (b)
Mean
Sample
Size(c)
Mean
Concentration (d.e)
Range of
Detection Limits (d.f)
Ranoe of Detected Concentrations (d)
On-stte Background (l.g)
IQAD
Organlcs:
• ODD
• DDE
• DDT
Tolban (1)
Inorganics:
Arsenic (h)
Chromium (h)
Mercury (h)
Nickel (h)
Selenium (h)
Zlnc(h)
21
31
3 /
1 /
31
31
31
3 1
31
3 1
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
. 3
3
3
0.0644
2.32
0.562
0.014
0.0867
0.433
0.0633
0.24
0.187
21.8
0.00365 • 0.02
NA
NA
0.0156 - 0.0325
NA
NA
NA
NA
NA
NA
0.035 -
0.465 -
0.0561 -
.142
3.69
1.54
0.002
0.07 -
0.37 -
0.06 -
0.12 -
0.16 -
15.6 •
0.1
0.47
0.07
0.48
0.19
30.6
0.0067
0.0036 - 0.0037
ND (0.00167)
ND (0.0026)
0.05 • 0.07
'0.38 - 0:89
0.06 • 0.07
0.1 - 1.6
0.2 - 0.3
16.2 • 19.5
• Chemical ol potential concern. See text lor a description ol procedures used to select chemicals ol potential concern.
NA - Not applicable: chemical detected In every sample or non-detected samples had high detection limits such that
one-hall ol the detection limit exceeded the maximum detectedvalue. (These values were excluded from the data and summary. See text.)
ND - Not detected. (Detection limits In parentheses.)
NC • Not calculated; only one sample available for mean calculation.
(a) Values presented for DDT and metabolites are the sum of values for the o,p'- and p.p'- Isomers.
(b) The number of samples In which the chemical was detected divided by the total number ol samples analyzed.
(c) the number ol samples used to calculate the mean.
(d) Values rounded to no more than three significant figures.
(e) Mean calculated lor normal distribution.
(I) Detection limits are only those lor which one-halt ol the detection limit was less than the maximum detected value. See text.
(g) Background samples collected from the Stlmpson Wildlile Sanctuary, located up-river Irom the CIBA-GEIG Y plant.
(h) Eliminated as a chemical of potential concern because concentrations were not statistically higher than background.
(I) Eliminated as a chemical ol potential concern based on concentratlon-toxlclty screening. See text and Appendix B.
-------
6.4 CLEANUP GOALS
The calculation of Remedial Goal Options (RGOs) has been provided
using the scenarios and assumptions utilized in EPA's conservative
assessment of the site. The result of these calculations provides
RGOs between 0.04 and 3.76 ppm total DDT. It should be noted that
because of the high level of uncertainties, conservative assumptions
were utilized in these scenarios.
For the majority of the scenarios considered, in order to achieve a HQ
of 1 or less, the concentration of DDTR in the floodplain must be no
greater than 1 ppm. However, remediating to 1 ppm is not practical
because this would require extensive excavation and destruction of the
bottom land hardwood forrest and the cypress tuepelo swamp that the
number was generated to protect. Given the current water management
in the area, restoration of the vegetative communities would be
unlikely. This level of remediation would result in unacceptable
short-term and long-term impacts to ecological receptors. Also, if
the swamps or wetlands are destroyed, additional land must be acquired
for mitigation. In addition, remediating to 1 ppm may not be
justified given the conservatism of the scenarios used in
Environmental Response Team's assessment.
With the exception of the cypress swamp, results from the suite of
toxicity test performed did not clearly show a trend that related
concentrations of DDTR at 20 ppm in soil or sediment to adverse
effects in plants or the adverse effects predicted by the levels of
contaminants bioaccumulated in animal tissue.
Based on the current information, EPA has determined that 15 ppm total
DDTR would provide the best balance of overall protection among
cleanup goals considered for remediation of the floodplain
soiI/sediment. Adjustments and modifications to the cleanup goals
based on area-specific factors and additional sampling results shall
be considered by EPA during the Remedial Design Study. If adjustments
to the cleanup level are made, such adjustments will be published in a
fact sheet, BSD, or ROD Ammendment.
Based on the available data, remediation to 15 ppm would reduce site-
wide contamination significantly. The applicability of remediating
areas to different levels based on ecological sensitivity and
contaminant risk would be evaluated further during the RD studies.
At a minimum, additional sampling would be conducted near the
northeast portion of the floodplain (near stations A5 and B5; see
figure 2-1 page 3) to determine if the elevated levels (at least 5
times background) of DDT present in several animal tissues are a
result of additional source areas. In addition, general
sampling/monitoring would be required to determine the effectiveness
of the remedy. A baseline sampling event(s) along with periodic RD
sampling event(s) would include the following:
52
-------
Crayfish or other.resident organisms, including fish would be analyzed
for DDTR residues and compared with DDTR levels in soil/sediment at
the same locations. In addition, the RD sampling would establish
threshold concentration in sediments or performance standards in
species above which an unacceptable level of accumulation is
occurring.
Due to the co-location of the contaminants, EPA has determined that
remediating the DDTR to acceptable levels would also reduce other
contaminants of concern to acceptable levels.
The contamination in areas of the floodplain could present an imminent
and substantial endangerment to public health, welfare or the
environment by actual or threatened release of contaminants to
ecological endpoints such as reproductive failure or reduced growth if
not addressed by the selected alternative in this document.
7.0 DESCRIPTION OF ALTERNATIVES
The floodplain area contains approximately 2500 cubic yards of
contaminated soil or sediment above 15 ppm DDTR. The following
section describes the alternatives considered for the remediation of
the contamination in the floodplain area (Operable Unit #3) at the
site. More detailed information can be found in the OU #3 Remedial
Investigation / Ecological Assessment Report and the Feasibility Study
Report Addendum found in the Administrative Record. ($750,000 has
been added to both Alternatives two and three to allow for the
additional studies and the performance monitoring that will be
conducted during the Remedial Design)
7.1 ALTERNATIVE 1; No Action
Superfund re'quires that the "No Action" Alternative be evaluated to
establish a baseline for comparison. For this operable unit, no
remedial action constitutes total dependence on natural biodegradation
and/or attenuation throughout the entire floodplain land surface.
7.2 ALTERNATIVE 2: In-situ Bioremediation
This alternative focuses on application of one remedial technology in
three designated areas within the Operable Unit. The three areas will
be discussed below. An in-situ treatment process of the soil/sediment
through a Ciba-developed, bioremediation process which establishes a
two-stage anaerobic/aerobic system requiring only the addition of
conditioned microbial seed, a substrate material, and a water layer
over the contaminated soil (anaerobic stage). Anaerobic conditions
achieve reductive dechlorination of pesticides (in this Operable Unit
the compounds of concern are DDT, DDD, and DDE, commonly referred to
as DDTR), and aerobic conditions further treat the dechlorinated
molecules. The process is best described as an accelerated, natural,
enzymatic reaction.
Based on the current data, the areas within the Operable Unit which
are designated for treatment are:
53
-------
1. The zone in the vicinity of Sample Point Bl at the upper end of.
the open Storm water Ditch (former Effluent Ditch).
2 . The zone in the vicinity of Sample Point Cl at the approximate
center of the open ditch.
3 . The zone in the vicinity of Sample Point Dl referred to as the
Cypress Swamp. Treatment would be conducted in this area based
on contaminant level with no consideration of property
boundary.
The remaining area within the Operable Unit (exclude 1, 2, and 3
above) is considered to be viable for No Action. Natural
biodegradation and/or attenuation of organic contaminant levels is
occurring in the general floodplain soil and sediment, and is adequate
for protection of human health and the environment as demonstrated by
site-specific risk assessment.
Following conclusion of in-situ treatment all affected areas would be
restored as closely as possible to natural elevations and wildlife
habitat conditions.
Soils, sediment and surface water monitoring shall be conducted at
this site. After demonstration of compliance with cleanup goals, the
Site including soil, sediment groundwater and resident organisms
and/or fish shall be monitored. Substantial initial progress in
achieving performance standards must be shown with five (5) years of
attaining soil cleanup goals. If substantial progress is
demonstrated, an additional five (5) years will be allowed to reach
performance standards. If the results of the five year study
indicates that substantial progress toward the Performance Standards
set forth in the RD Additional Studies Report is not being made,
additional remediation may be required.
The total present worth cost for this alternative is approximately
$2,250,000.
7 .3 ALTERNATIVE 3 ; OU #2 Treatment of Excavated soils Combined with
In-situ Bioremediation
This alternative combines two remedial technologies into a synergistic
strategy which addresses both the topographic and contaminant
concentration profiles within the Operable Unit. Based on the current
data, the specific elements of the strategy are:
1. Within the zone of the Operable Unit in the vicinity of Sample
Point Bl at the upper end of the Storm water Ditch (former
Effluent Ditch); and
2 . The zone in the vacinity of Sample Point Cl at the approximate
center of the open ditch, soils/sediments would be excavated to
the 15 ppm clean-up level for DDTR.
54
-------
Removed soils/sediments that exceed 500 ppm DDTR would be transported
into the area of the Mclntosh Site designated as OU #2 and OU #4
treatment area and processed according to the procedures for DDTR
contaminated soil specified in the Records of Decision and Consent
Decrees for OUs #2 and #4. Excavated soils from the floodplain that
does not exceed 500 ppm DDTR would be available to be used as
subsurface backfill for OU #2 areas. Soils exceeding 500 ppm DDTR
would be thermally treated to meet all appropriate standard with the
soils from OUs #2 and #4. The Remedial Action schedule for for OU #3
would be integrated with the OU #2 and OU #4 schedules to ensure no
delay of the OU #2 and OU #4 remediations.2 Removed soil/sediment
from the floodplain would be replaced with clean material of a similar
soil type and vegetated to restore .this area to its original elevation
and wildlife habitat characteristics.
3. Within the zone of the Operable Unit in the vicinity of Sample
Point Dl at the location referred to as the Cypress Swamp,
sediment with concentrations of DDTR in excess of the cleanup
level would be treated by application of a Ciba-developed, in-
situ, anaerobic/aerobic bioremediation process as previously
described in Alternative No. 2.
This treatment method would be focused on the actual DDTR contaminant
profile in this area regardless of property ownership, and would be
continued until DDTR concentrations in sediment are reduced to less
than the cleanup goal for that area. Following conclusion of in-situ
treatment, the Cypress Swamp would be restored as closely as possible
to natural elevations and wildlife habitat conditions.
Based on the current information, the remaining area within the
Operable Unit (exclude 1, 2 and 3 above) is considered to be viable
for No Action. Natural biodegradation and/or attenuation of organic
contaminant levels is occurring in the general floodplain soil and
sediment, and is adequate for protection of human health and the
environment as demonstrated by site-specific risk assessment.
Soils, sediment and surface water monitoring shall be conducted at
this site. After demonstration of compliance with cleanup goals, the
Site including soil, sediment groundwater and resident organisms
and/or fish shall be monitored. Substantial initial progress in
achieving performance standards must be shown with five (5) years of
attaining soil cleanup goals. If substantial progress is
demonstrated, an additional five (5) years will be allowed to reach
performance standards. If the results of the five year study
indicates that substantial progress toward the Performance Standards
set forth in the RD Additional Studies Report is not being made,
additional remediation may be required.
The total present worth cost to execute this alternative is
approximately $1,500,000.
55
-------
8.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
This section of the ROD provides the basis for determining which
alternative provides the best balance,with respect to the statutory-
balancing criteria in Section 121 of CERCLA and in Section 300.430 of
the NCP. The major objective of the FS was to develop, screen, and
evaluate alternatives for the remediation of the contaminated soils at
the Ciba-Geigy Site. A wide variety of technologies were identified
as candidates for remediating the contaminated soils/sediments at the
Site. These technologies were screened based on their feasibility
with respect to the contaminants present and the Site characteristics.
The technologies that remained after the initial screening were
combined into potential remedial alternatives and evaluated in detail.
The remedial alternatives selected from the screening process were
evaluated using the following nine evaluation criteria:
Overall protection of human health and the environment.
Compliance with applicable and/or relevant Federal or State
public health or environmental standards.
Long-term effectiveness and permanence.
Reduction of toxicity, mobility, or volume of hazardous
substances or contaminants.
Short-term effectiveness, or the impacts a remedy might have o
the community, workers, or the environment during the course
implementing it.
Implementability, that is, the administrative or technical
capacity to carry out the alternative.
Cost-effectiveness considering costs for construction,
operation, and maintenance of the alternative over the life of
the project, including additional costs should it fail.
Acceptance by the State.
Acceptance by the Community.
The NCP categorizes the nine criteria into three groups:
(1) Threshold Criteria - overall protection of human health and the
environment and compliance with ARARs (or invoking a waiver) are
threshold criteria that must be satisfied in order for an
alternative to be eligible for selection;
(2) Primary Balancing Criteria - long-term effectiveness and
permanence; reduction of toxicity, mobility, or volume; short-term
effectiveness; implementability; and cost-effectiveness are primary
balancing factors used to weigh major trade-offs among alternative
hazardous waste management strategies; and
56
-------
(3) Modifying Criteria - state and community acceptance are
modifying criteria that are formally taken into account after public
comment is received on the proposed plan and incorporated into the
ROD.
The selected alternative must meet the threshold criteria and comply
with all ARARs or be granted a waiver for compliance with ARARS. Any
alternative that does not satisfy both of these requirements is not
eligible for selection. The Primary Balancing Criteria are the
technical criteria upon which the detailed analysis is primarily
based. The final two criteria, known as Modifying Criteria, assess
the public's and the state agency's acceptance of the alternative.
Based on these final two criteria, EPA may modify aspects of a
specific alternative.
The following analysis is a summary of the evaluation of alternatives
for remediating Operable Unit #3 of the Ciba-Geigy Superfund Site
under each of the criteria. A comparison is made between each of the
alternatives for achievement of a specific criterion.
THRESHOLD CRITERIA
8.1 OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
All of the alternatives except the "No Action" alternative would
provide protection to the environment. In Alternative 1,
concentrations of the contaminants in the surface water, soil and
sediment would continue to potentially have an adverse impact on the
ecosystem. Both Alternatives 2 and 3 would provide protection to the
environment by the reduction of ecological risks to acceptable levels
in the areas and to the species of concern. Alternative 3 would have
the potential for higher short-term ecological risk during the period
when contaminated soils are being excavated from the open ditch area,
but a much lower overall long-term ecological risk because the
contaminated soil is permanently removed from the area on an
accelerated schedule and replaced with clean soil. In both
Alternatives 2 and 3 the more ecologically areas would be treated by
in-situ bioremediation. Since the "No Action" Alternative does not
meet one of the threshold criteria, it would not be considered further
in this discussion.
8.2 COMPLIANCE WITH ARARs
Alternatives 2 and 3 would comply with ARARs or justify a waiver.
Chemical Specific ARARs would be met through compliance with the
groundwater protection standards (i.e., MCLs) at the Point of
Compliance as defined in Ciba-Geigy's RCRA permit and through
compliance with NPDES permit conditions for water removed and treated
in the contaminated areas. Soils excavated in Alternative 3 would be
analyzed to determine if they are RCRA hazardous waste. If required,
RCRA hazardous waste would be treated to legislative treatment
standards, as adjusted pursuant to a treatability variance prior to
land disposal.
57
-------
8.3 LONG-TERM EFFECTIVENESS
Both Alternatives 2 and 3 would provide long-term effectiveness by
permanently reducing target contaminants in soil and sediment, in
specific zones of the floodplain, to values below acceptable risk
levels. In Alternative 3, the combination of the two remedial
technologies, removal and biotreatment, in specific zones of the
floodplain area depending on both topography and contaminant
concentration is the most effective method to ensure long-term
ecological health in this portion of the Mclntosh Site.
8.4 REDUCTION OF TOXICITY. MOBILITY OR VOLUME BY TREATMENT
Alternative 2 would reduce the toxicity and the volume of the
contaminants of concern in soil and sediment by utilizing a moderately
aggressive in-situ biotreatment technology. The in-situ process would
not reduce the mobility of target contaminants. This is not an issue
of significance, however, since the DDTR compounds are relatively
immobile due to a low solubility in water. Alternative 3 would reduce
toxicity, mobility and volume of contaminants threatning the ecosystem
by excavating the contaminated soils and sediment which exceed the 15
ppm DDTR cleanup goal and relocating or treating them with the
contaminated soils and sediment from Operable Units 2 and 4 at the
Site. Excavated soils/sediments that exceed 500 ppm DDTR would be
transported into the area of the Mclntosh Site designated as OU #2 and
OU #4 treatment area and processed according to the procedures for
DDTR contaminated soil specified in the Record of Decision and Consent^
Decree for OUs #2 and #4. Excavated soil from the floodplain that
does not exceed 500 ppm DDTR would be available to be used as
subsurface backfill for the OU #2 areas. The Remedial Action schedule
for for OU #3 would be integrated with the OU #2 and OU #4 schedules
to ensure no delay of the OU #2 and OU #4 remediations. Excavated
soils/sediments from the floodplain would be replaced with clean
material of a similar soil type and vegetated to restore this area to
its original elevation and wildlife habitat characteristics.
Alternative 3 would virtually eliminate a major portion of the toxic
effects along with a substantial reduction in volume through
excavation and/or treatment.
8.5 SHORT-TERM EFFECTIVENESS
Accomplishment of the remedial objectives for this Operable Unit is
achieved in the shortest timeframe by the implementation of
Alternative 3. Depending on weather conditions, the soil removal in
the open ditch could be accomplished in approximately 8 months as
compared to approximately 8 years to reach the remedial option goals
with Alternative 2. In Alternative 3, the risks to remedial workers
would be moderately higher during the soil removal phase, but are very
controllable through conventional field health and safety practices
with heavy emphasis on appropriate personal protective equipment. Thej
removal of contaminated soil does increase short-term exposure of
58
-------
certain wildlife species to higher contaminant concentrations but this
is offset by the permanent long-term reduction of the contaminants.
8.6 IMPLEMENTABILITY
The construction techniques and equipment required to prepare the
treatment sites utilizing Alternatives 2 and 3 can be categorized as
standard civil engineering specifications. The necessity to construct
an alternative storm water drainage way in a floodplain area does
limit initial field activity to relatively dry periods. The
procedures and equipment for operation of the treatment process are
typical to those used in conventional land farming. Alternative 2 may
require periodic drainage or flooding of the soil treatment areas to
create aerobic or anaerobic biological conditions, and repair or
restoration of treatment sites following erosion damage due to
occasional flood events. The Ciba-Geigy developed, in-situ
bioremediation process has been tested on the target contaminants in
the laboratory and in field pilots using actual soil from the Operable
Unit. Test indicate good contamination reduction rates.
8.7 COST
The estimated total cost of Alternative 2 in 1994 dollars is
$2,250,000. This estimate includes site preparation, operation of the
in-situ bioremediation process for up to eight years and annual
maintenance of the treatment sites throughout the treatment period.
The estimated cost of Alternative 3 in 1994 dollars in $1,500,000.
This estimate includes site preparation (in-situ bioremediation
phase), a soil removal/processing and clean soil placement phase, an
in-situ bioremediation phase for up to five years, and annual
maintenance of the bioremediation treatment site .throughout the
treatment period.
8.8 STATE ACCEPTANCE
The State of Alabama concurs with Alternative #3 to remediate the
contaminated soil/sediment in the floodplain at the Ciba-Geigy Site.
8.9 COMMUNITY ACCEPTANCE
Based on the favorable comments expressed at the December 20, 1994
public meeting and the lack of negative written comments received
during the comment periods, it appears that the Mclntosh community
generally agrees with the selected remedy.
9.0 SELECTED REMEDY
A. SOURCE CONTROL
Based upon consideration of the requirements of CERCLA, the NCP, the
detailed analysis of alternatives and public and state comments, EPA
has selected a source control remedy for this operable unit. At the
completion of this remedy, the risk associated with this site is
59
-------
expected to be protective of human health and the environment. The
total present worth cost to execute the selected remedy, Alternative
#3, is estimated at $1,500,000.
Source control remediation will address the contaminated
soils/sediments at the Site. Source control shall include excavation
of soils, sediments and related material, transportation, staging,
dewatering, treatment (if necessary), placement of treated material,
back filling and bioremediation.
A.I. The manor components of source control to be
implemented include;
Excavation of materials contaminated with greater than 15 ppm of
DDTR in the floodplain area and transportation of these materials to
the upland areas near the OU #2 and OU #4 remediation areas.
Transported soils/sediments that do not exceed 500 ppm DDTR may be
used for subsurface backfill for OU #2 areas. Transported
soils/sediments that exceed 500 ppm DDTR shall be thermally treated
with the OU #2 and OU #4 soils/sediments;
In-situ bioremediation for the ecologically sensitive areas (cypress
swamp(s) and bottom-land hardwood forest) if Ciba-Geigy demonstrates
to EPA's satisfaction that the technology will provide sufficient
and timely degradation of all DDTR. In addition, Ciba-Geigy must
demonstrate the timely degradation of DDTR without causing a
significant adverse impact to those areas or increasing the rate of
methylation of mercury in areas where the wastes are commingled. If
Ciba-Geigy is unable to demonstrate to EPA's satisfaction that in-
situ bioremediation will achieve all of the remedial goals for the
area(s), objective #2 of the Remedial Design study below will be
used to address the area(s).
A.2. Performance Standards
The Performance Standards for this component of the selected remedy
include the following excavation and treatment standards:
a. Excavation Standards
Excavation shall continue until the remaining soil and material
achieve a maximum concentration of 15 ppm DDTR. All excavation
shall comply with ARARs, including, but not limited to OSHA and
state standards. Testing methods approved by EPA shall be used
to determine if the maximum DDTR concentration levels have been
achieved.
During the initial phase of the Remedial Design, additional
sampling activities will be conducted to accomplish the
following objective:
1. To provide the baseline levels which will be used to monitor
the long-term effectiveness of the remediation;
60
-------
2. To determine if it is necessary to modify cleanup goals in
different areas of the floodplain based on ecological
sensitivity (i.e., To avoid the unnecessary destruction of
habitats that may be irreplaceable by balancing the effects of
the contaminants with the effects of the cleanup); and,
3. To select appropriate species to be used for measuring the
effectiveness of the remedy. To establish performance
standards or maximum contaminant levels in those species to
determine when site remediation is successful.
If EPA modifies the cleanup goals based on the results of the
Additional Studies Report, the public will be notified by a Fact
Sheet, BSD or a ROD Amendment.
b. Treatment Standards
All excavated soils, sediments and related materials containing
concentrations of DDTR greater than 500 ppm will be thermally
treated with the OU #2 and OU #4 soils. All treatment and
disposal shall comply with applicable or relevant.and
appropriate requirements (ARARs), including RCRA and TSCA.
Soil excavated from the floodplain (OU #3) that is below 500 ppm
DDTR may be used as subsurface backfill for excavated areas of OU
#2. Prohibiting the placement of soil or sediment with
concentrations greater than 500 ppm DDTR will ensure that subsurface
treatment levels established in the OU #2 ROD for the protection of
groundwater will not be exceeded. Based on the current information,
the majority of the soil and sediment would be available to be used
as subsurface backfill.
B. COMPLIANCE TESTING
Soils, sediments and surface water monitoring shall be
conducted at this site. After demonstration of compliance with
cleanup goals, the Site including soils, sediments,
groundwater, resident organisms and/or fish shall be monitored.
Substantial initial progress in achieving performance standards
must be shown with five (5) years of attaining soil cleanup
goals. If substantial progress is demonstrated, an additional
five (5) years will be allowed to reach performance standards.
If the results of the five year study indicates that
substantial progress toward the Performance Standards set forth
in the RD Additional Studies Report is not being made,
additional remediation may be required. "Substantial Progress"
shall be defined during the initial phase of the Remedial
Design (i.e., RD/RA negotiations or RD Workplan and Additional
Studies Workplan).
In summary, Alternative 3 would achieve substantial risk reduction
through excavation and/or treatment of the principal threat to the
floodplain ecosystem at the Ciba-Geigy Superfund Site. Legislated
treatment standards would be achieved, as adjusted pursuant to a
61
-------
CERCLA treatability variance for soil/sediment that exceed 500 ppm
DDTR. The treatment technology which has been demonstrated to achieve!
these standards for the RCRA wastes present at the Site is thermal
destruction. Excavated soils that do not exceed 500 ppm DDTR would be
used as subsurface backfill for those areas. This action would be
both protectective of the environment and cost-effective. Alternative
3 reduces not only the mobility of the contaminants but also the
toxicity and volume of the contaminants. Alternative 3 achieves a
higher level of permanent remediation by removal of contaminants from
the highest concentration zones within the Operable Unit. Alternative
3 produces acceptable results in a significantly shorter time than
other alternatives. In addition, Alternative 3 was the most cost
effective of the alternatives evaluated. Based on the information
available, the preferred alternative represents the best balance among
the criteria used to evaluate remedies. Alternative 3 is protective
of human health and the environment, would attain ARARs, would be cost
effective, and would utilize permanent solutions and alternative
treatment technologies or resource recovery technologies to the
maximum extent practicable.
10.0 STATUTORY DETERMINATION
The selected remedy is protective of human health and the environment,
complies with federal and state requirements that are legally
applicable or relevant and appropriate to the remedial action, and is
cost-effective. Finally, it is determined that this remedy maximizes
long-term effectiveness. ',
Because this remedy would result in hazardous substances remaining on-
site, a review would be conducted within five years after commencement
of the remedial action to ensure that the remedy continues to provide
adequate protection of human health and the environment.
10.1 PROTECTIVE OF HUMAN HEALTH AND THE ENVIRONMENT
The selected remedy protects human health and the environment through
excavating and/or treating a principal threat remaining at the Site.
The selected remedy provides protection of human health and the
environment by eliminating, reducing, or controlling risk through
treatment, relocation, engineering controls and/or institutional
controls.
10.2 ATTAINMENT OF THE APPLICABLE OR RELEVANT'AND APPROPRIATE
REQUIREMENTS (ARARs)
Remedial actions performed under CERCLA must comply with all
applicable or relevant and appropriate requirements (ARARs). All
alternatives considered for the Ciba-Geigy Site were evaluated on the
basis of the degree to which they complied with these requirements.
The selected remedy was found to meet or exceed the following ARARs,
as discussed below.
62
-------
Clean Water Act
Section 404(b) of the Clean Water Act and implementing regulations
will be applicable to wetlands. If excavation of the wetlands occurs
during the remedial action, on-site restoration of the excavated
wetlands shall satisify mitigation requirements of this section.
Resource Conservation and Recovery Act
Many RCRA requirements are considered relevant and appropriate for
remedial activities proposed at the Mclntosh plant. The excavated
soils and sludges will be representatively analyzed to determine if
they are RCRA hazardous wastes. If RCRA hazardous waste is found it
will be used as backfill in the excavated areas of Operable Units Two
and Four with the soils from Operable Unit Two and Four after RCRA
legislated treatment standards pursuant to a treatability variance,
granted upon ROD signature, are met. EP Toxicity and TCLP analyses
will be performed to ensure that treatment standards, through a
treatability variance, are met. A pilot study and a trial burn will
be required to ensure that the incinerator will meet the Destruction
Removal Efficiencies for the contaminants at the Site. The primary
activities include excavation of the majority (discression will be
utilized in the ecologically sensitive areas) of soil/sediment that
exceed 15 ppm: soils that exceed 500 ppm DDTR (1/10 of the most
conservative of the subsurface cleanup level which was generated based
on the protection of groundwater in the ROD addressing OU#2), will be
incinerated, soil/sediment that are below SOOppm DDTR will be
available to used as subsurface backfill in OU #2 areas, in-situ
bioremediation of the ecologically sensitive areas, backfilling of the
excavated areas of the floodplain with cleanfill and continuing pump
and treatment of the contaminated groundwater. RCRA design standards
will be incorporated into the remedial design of all construction
activities so that the substantive requirements of all applicable RCRA
regulations are met.
Other Guidance To Be Considered
Other Guidance To Be Considered (TBCs) include health based advisories
and guidance. TBCs have been utilized in estimating incremental
cancer risk numbers for remedial activities at the sites. The risk
numbers are evaluated relative to the normally accepted point of
departure risk range of lxlO~4 to IxlO"6.
Clean Air Act
Air emissions from the remedial activities at the Site, including
thermal treatment, would be monitored to ensure compliance with the
substantive requirements of the Clean Air Act. Fenceline air
monitoring will be conducted to ensure that contaminant concentrations
do not exceed levels considered to be safe for human health. If
levels are exceeded, mitigative procedures such as dust suppression or
vapor capture will be employed to prevent harmful levels of air
emissions from leaving the Site.
63
-------
Alabama State Water Quality Standards
Perched water at certain areas and stormwater which contacts Site
materials during remediation activities will be routed through the
existing on-site wastewater treatment plant. In addition,
contaminated groundwater extracted by the current pump and treat
system and incinerator scrubber water will be treated before discharge
into the Tombigbee River through the current NPDES permit to ensure
protection of aquatic life.
Waivers
No ARAR waivers are being granted however, the selected alternative
will comply with the LDRs through a treatability variance for any
contaminated soils and debris that would have to be treated with the
OU #2 soils and sediments.
10.3 COST EFFECTIVENESS
The estimated cost of EPA's selected remedy is approximately
$1,500,000. This cost does not include the RD sampling activities
because the specific details of the study have not been determined.
The RD study would be required regardless of the alternative selected;
therefore, it would not affect the selection process. Cost
effectiveness is determined by comparing the cost of all alternatives
being considered with their overall effectiveness to determine whether^
the costs are proportional to the effectiveness achieved. EPA
evaluates the incremental cost of each alternative as compared to the
increased effectiveness of the remedy. The selected remedy,
Alternative 3, was chosen for its high degree of effectiveness at
reducing the mobility, toxicity, and volume of the contaminants and
its long-term protectiveness for the ecosystem. In addition,
alternative 3 is the least expensive of the alternatives that meet the
threshold criteria.
10.4 UTILIZATION OF PERMANENT SOLUTIONS TO THE MAXIMUM
EXTENT PRACTICABLE
EPA believes the selected remedy is the most appropriate cleanup
solution for Operable Unit# 3 of the Ciba-Geigy Site and provides the
best balance among the evaluation criteria of the remedial
alternatives evaluated. This remedy provides effective protection in
both the short-term and long-term to potential human and environmental
receptors, is implementable, and is cost-effective.
Thermal treatment of the highly contaminated soils that exceed 500 ppm
DDTR, with pre-treatment options proven effective during the design,
and in-situ bioremediation of the more ecologically sensitive areas
contaminated soil, if proven effective during the design, will
effectively reduce and/or eliminate the mobility of hazardous waste
and hazardous substances to the environment.
10.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
64
-------
The statutory preference for treatment will not be met because the
selected remedy only treats the contaminated soils/sediments that
exceed 500 ppm DDTR and the contamination that exist in the
ecologically sensitive areas. In addition, the selected remedy allows
for the relocation ofs the contaminated soils that are below 500 ppm
DDTR to subsurface areas of OU #2. The relocation of the soils and
sediments below 500 ppm DDTR removes a principal threat posed to the
ecosystem without exceeding OU #2 subsurface treatment levels which
were generated to ensure the protection of groundwater.
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES
Following the issuance of the Proposed Plan, changes have been made to
the preferred alternative in response to comments submitted to EPA
during the public comment period. The Proposed Plan identified in-
situ bioremediation as an alternative for addressing contamination in
the more ecologically sensitive areas (swamp and bottomland hardwood
forrest). One commenter, raised the concern that in-situ
bioremediation that is being considered for the remediation of DDTR,
could have an adverse effect on Mercury in areas where the DDTR and
Mercury are co-mingled (the swamp areas). The commenter expressed
concern that bioremediation of the DDTR in the swamp areas could cause
mercury to become more bioavailable to organisms in the area.
Additional concern was raised regarding the ability of the in-situ
bioremediation to reduce DDD and DDE to acceptable levels in a timely
manner. The difficulty in keeping conditions favorable for effective
bioremediation during seasonal changes (dry season to flood season)
was questioned. Based on these concerns, the scope of RD studies has
been expanded.
The additional Remedial Design Studies shall accomplish the following
objectives:
1. The remedial design studies will provide the baseline levels
which will be used to monitor the long-term effectiveness of
the remediation.
2. To determine if it is necessary to modify cleanup goals in
different areas of the floodplain based on ecological
sensitivity (i.e., To avoid the unnecessary destruction of
habitats that may be irreplaceable by balancing the effects of
the contaminants with the effects of the cleanup).
3. To select appropriate species to be used for measuring the
effectiveness of the remedy. To establish performance
standards or maximum contaminant levels in those species to
determine when site remediation is successful. Substantial
progress in achieving performance standards must be shown
within five (5) years of attaining soils/sediments cleanup
goals. If substantial progress is demonstrated, an additional
five (5) years will be allowed to reach performance standards.
"Substantial Progress" shall be defined during the initial
phase of the Remedial Design (i.e., RD/RA negotiations or RD
Workplan and Additional Studies Workplan).
65
-------
4. No later than the submission of the RD Additional Sampling
Report, Ciba-Geigy must be able to demonstrate to EPA's
satisfaction that in-situ bioremediation will provide '
sufficient and timely degradation of all DDTR. In addition,
Ciba-Geigy must demonstrate the timely degradation of DDTR
without causing significant impact to the shallow tree roots of
the bottomland hardwood forest or without increasing the rate
of methylation of mercury in areas where the wastes are
commingled. If Ciba-Geigy is unable to demonstrate to EPA's
satisfaction that in-situ bioremediation will achieve all of
the remedial goals for the area(s), objective #2 of the
Remedial Design study below will be used to address the
area(s).
5. The results of the RD sampling activities report and any
significant decisions (including but not limited to
modification of cleanup level or implementation of performance
standards) made by EPA in consultation with ADEM, will be
released to the public in a fact sheet, BSD or ROD Amendnent .
In addition, the proposed plan the listed the treatment levels for
DDT and its metabolites (DDT - 503 ppm, ODD - 675 ppm and DDE - 1653
ppm) and indicated that excavated soils and sediments from the
floodplain that did not exceed these numbers could be used as
subsurface backfill in the OU #2 areas.
In an effort to simplify the field analyses the language in the ROD
has been revised as follows: Soil excavated from the floodplain (OU
#3) that is below 500 ppm DDTR may be used as subsurface backfill for
excavated areas of OU #2. Prohibiting the placement of soil or
sediment with concentrations greater than 500 ppm DDTR will ensure
that subsurface treatment levels established in the OU #2 ROD for the
protection of groundwater will not be exceeded.
66
-------
APPENDIX A
Responsiveness Summary
Ciba-Geigy Superfund Site
Mclntosh, Washington County, Alabama
67
-------
RESPONSIVENESS SUMMARY
The U.S. Environmental Protection Agency (EPA) held a public comment
period from December 15, 1994 to January 14, 1995 for interested
parties to comment on EPA's Proposed Plan (PP) for the Ciba-Geigy
Site. The comment period included a public meeting on January 20,
1995, conducted by EPA and the Alabama Department of Environmental
Management (ADEM), held at the Mclntosh Town Hall. The meeting
presented the results of the studies undertaken and the preferred
remedial alternative for remediation of the contaminated media at the
Site.
A responsiveness summary is required by CERCLA (Superfund) Section
117, and it is policy to provide a summary of significant public
comments and concerns about the Site, as raised during the public
comment period and the public meeting, and the Agency's responses to
those concerns. All comments summarized in this document have been
factored into the remedy selection process for cleanup of Operable
Unit Three at the Site.
This responsiveness summary for the Ciba-Geigy Site is divided into
the following sections:
I. Overview; This section discusses the recommended alternative
for remedial action and the public's reaction to this
alternative.
II. Background on Community Involvement and Concerns: This section
provides a brief history of community interest and concerns
regarding the Ciba-Geigy Site.
III. Summary of Major Questions and Comments Received During the
Public Comment Period and EPA's and ADEM's Responses; This
section presents the written comments submitted during the
comment period and provides EPA's responses to these comments.
IV. Remaining Concerns; This section discusses community concerns
that EPA should be aware of in design and implementation of the
remedial alternative for the Site.
I. Overview
The preferred remedial alternative was presented to the public in a
proposed plan / fact sheet on December 15, 1994. The recommended
alternative addresses the source of contamination in the floodplain
by removing/treating the contaminated waste that exceed the cleanup
levels.
This operable unit is the final of four operable units at the Ciba-
Geigy Sites.
68
-------
The major components of the selected remedy for operable unit three
include:
* Excavation of approximately 2500 cubic yards of soil and sediment
above the cleanup level, 15 ppm DDTR. 15 ppm DDTR has been
determined to be the best balance of protection for the environment.
Excavated soil and sediment would be thermally treated with the OU
#2 and OU #4 soil if the concentrations is above 500 ppm DDTR.
Previous RODs for OU #2 and OU #4 were signed that required
excavation and thermal treatment of soil that exceeded cleanup
levels which were generated to ensure the protection of groundwater.
Soil excavated from the floodplain (OU #3) that is below 500 ppm
DDTR may be used as subsurface backfill for the excavated areas of
OU #2.
* Backfilling the excavated areas with clean fill.
* In-situ bioremediation of approximately 10 acres of the more
ecologically sensitive areas (cypress swamp(s) and bottom land
hardwood forrest) that exceed the cleanup level. if Ciba-Geigy
demonstrates to EPA's satisfaction that in-situ bioremediation will
provide sufficient and timely degradation of all DDTR without
increasing the rate of methylation of mercury in areas where the
wastes are commingled. If Ciba-Geigy is unable to demonstrate to
EPA's satisfaction that in-situ bioremediation will achieve all of
the remedial goals for the area(s), the ares(s) will be addressed by
objective #2 of the Remedial Design Study (below).
* Conducting Remedial Design studies to accomplish the following
objectives:
1. To provide the baseline levels which will be used to monitor
the long-term effectiveness of the remediation;
2. To determine if it is necessary to modify cleanup goals in
different areas of the floodplain based on ecological
sensitivity (i.e., To avoid the unnecessary destruction of
habitats that may be irreplaceable by balancing the effects of
the contaminants with the effects of the cleanup); and,
3. To select appropriate species to be used for measuring the
effectiveness of the remedy. To establish performance
standards or maximum contaminant levels in those species to
determine when site remediation is successful.
Based on the results of the Remedial Design studies, the cleanup level
may be adjusted.
If adjustments to the cleanup level are made, such adjustments will be
published in a fact sheet, BSD, or ROD Ammendment.
II. Background on Community Involvement and Concern
69
-------
The Mclntosh community has been aware of the contamination problem
at the Ciba-Geigy Site for several years. EPA distributed the firslj
fact sheet to the public in August of 1989.
A public meeting was held on December 20, 1994 in Mclntosh Alabama.
At this meeting representatives from EPA discussed the results of
the Ecological Assessment Report, presented the recommendation of
EPA and ADEM for cleanup of the floodplain, answered questions and
addressed community concerns.
Based on the comments received during the comment period, the public
supports the approach for remediation of the floodplain at the Ciba-
Geigy Site.
Ill. Summary of Manor Questions and Comments Received During the
Public Comment Period and EPA's or ADEM's Responses
The following comments were made by concerned citizens in reference
to the Proposed Plan addressing the contamination in OU #3 at the
Site. The Proposed Plan was released to the public in December
1994.
Comment:
1. A commenter was concerned that excavating soil/sediment that
exceeded the floodplain cleanup goals and using it as backfill
in excavated areas from OU #2 and OU #4 would not be protective
for the other areas.
Response:
The soil from the ditch or any other area that exceeds the cleanup
goal in the floodplain would be excavated to ensure the protection
of the environment/ecosystem. The soils/sediments cleanup levels
for OU #2 and OU #4 are based on the protection of groundwater.
Since the numbers to protect the environment are more conservative
than the numbers to protect the groundwater, it is likely for soils
sediments to exceed the floodplain cleanup goals and be acceptable
for backfill in the upland areas.
Comment:
2. A commenter was concerned that the remedy we are selecting to
address the contamination may not be safe 20 years from now
since 20 years ago, when Ciba-Geigy buried this material, it
was legal.
Response:
70
-------
Based on the current information and environmental regulations, we
believe this remedy provides the best balance of the nine criteria
as it reduces the principal threat in the floodplain. In addition,
periodic monitoring will be conducted to monitor the effectiveness
of the remediation. If the current environmental regulations change
and the remedy is no longer protective, modifications will be made
to the remedy to ensure protection to human health and the
environment.
Comment:
3 . A citizen expressed concern about eating fish near the Ciba-
Geigy and Olin Chemicals since the Health Department issued a
fish advisory recommended that the amount of fish consumption
be reduced and EPA has not made a statement.
Response:
EPA released the final report on a study on the Mobile River. The
report indicated that the stretch of the Tombigbee River near the
Ciba-Geigy and Olin chemical plants might present an excessive risk
only to a subsistence fisherman eating fish caught in this area.
The Alabama Department of Public Health (ADPH) will determine the
need for any statements on fish consumption.
Comment:
4. A commenter expressed a concern about EPA selecting a cleanup
number of 15 ppm for DDTR in the floodplain although our models
indicate that 1 ppm DDTR would be a safe cleanup number.
Response:
Although excavating to 1 ppm DDTR would allow EPA to say with
confidence that the concentrations of DDTR left would not cause any
harm to the plants and animals in the floodplain, the volume of
soils and sediments, that would have to be removed to reach 1 ppm
DDTR would kill many of the plants and animals we are trying to
protect. In addition, based on the current information, EPA has
determined that excavating to 15 ppm DDTR would provide the best
balance of removing soils and sediments that may cause harm to
plants and animals while allowing areas with low levels of
contamination and healthy ecosystems to remain undisturbed.
Additional samples will be collected and analyzed to ensure that 15
ppm DDTR is protective. The final cleanup number may be adjusted
based on the results of the studies. If the cleanup level is
adjusted the public will be notified by a fact sheet, BSD or a ROD
ammendment.
Comment:
5. A concerned citizen asked how much the cost of the remedy would
change if the cleanup numbers changed.
Response:
71
-------
At this time EPA has not estimated how much the cost would change if
the cleanup number changed. However, if the results from the
additional studies indicated that the cleanup level needed to be
changed, the new cleanup level and associated cost would be
presented in a fact sheet and released to the public.
Comment:
6. A concerned citizen wanted to know when actual work in the
field would begin at the Ciba-Geigy Site.
Response:
The current schedule projects construction field activities to begin
early 1997. However, EPA, ADEM and Ciba-Geigy are currently looking
for ways to begin the construction activities around mid-year of
1996.
Comment:
7. A commenter was concerned that another federal or state agency
would require that additional work be conducted after the ROD
is implemented.
Response:
EPA makes every effort to incorporate or address all concerns of
federal and state agencies to select final cleanup remedies. EPA
will monitor the site to insure that the remedy remains protective.
However, EPA does not regulate other agencies' actions
Comment:
8. A commenter expressed a concern for the decrease in property
value of the homes in Mclntosh. He indicated that he believed
the two Superfund Sites in the town were the cause for the
property value decrease and he wanted to know when would the
site could be deleted from the NPL.
Response:
EPA is continuing to look for ways to make cleanups more efficient
and cost effective. It is our goal to conduct quality cleanups in
the shortest time possible. EPA will consider deleting the site as
soon as protection of people and the environment have been achieved.
Comment:
9. A commenter indicated that the Health Department and EPA were
giving conflicting information since the fish advisory issued
by the health department discouraged eating large amounts of
fish caught near the Olin Basin (adjacent to the Ciba-Geigy
floodplain) and EPA has not indicated that the fish are
significantly impacted.
72
-------
Response: .
The two agencies have different responsibilities. EPA's
responsibility is to inform you of the impact the contamination from
the site may have on the fish and to reduce risks related to the
contaminants. The Health Department is responsible for determining
if it is safe for you to eat the fish. Therefore, the two agencies
provide information on different aspects of the contamination.
IV. Remaining Concerns
The community's concerns surrounding the Ciba-Geigy Site will be
addressed in the following areas: continued community relations
support of the ongoing Operable Unit #2 and #4 Remedial
Design/Remedial Action (RD/RA) activities and community relations
support for the upcoming Operable Unit #3 RD/RA activities.
Community relations will consists of making available final
documents (i.e., Remedial Design Workplan, Remedial Design Reports,
etc.) in a timely manner to the local repository. Also, issuance of
fact sheets to those on the mailing lists will further provide the
community with project progress and a schedule of events. The
community will be made aware of any principal design changes made
during the project design. If at any time during the RD/RA new
information is revealed that could affect the implementation of the
remedy or if the remedy fails to achieve the necessary design
criteria, the Record of Decision may be revised through amendment or
an explanation of significant difference to incorporate new
technologies that will attain the necessary performance criteria.
Community relations activities will remain an active aspect
throughout the remainder of the remedial activity at this Site.
73
-------
APPENDIX B
CONCURRENCE LETTER
74
-------
John M. Smith. Director
Mailing Address:
PO BOX 301463
MONTGOMERY AL
36130-1463
Physical Address:
1751 Cong. W.L.
Dickinson Drive
Montgomery, AL
36109-2608
(334)271-7700
FAX 270-5612
Field Offices:
110 Vulcan Road
Kingham, AL
9-4702
) 942-6168
FAX 941-1603
400 Well Street. NE
P.O. Box 953
Decatur, AL
35602-0953
(205)353-1713
FAX 340-9359
2204 Perimeter Road
Mobile, AL
36615-1131
(334)450-3400
FAX 479-2593
M.
^>-M:/£
I*!:
-------
SOUTH
SUPERFUND
STATE OF ALABAMA All |? | 58 Pjj '95
DEPARTMENT OF PUBLIC HEALTH-, .,...„. r
DONALD E. WILLIAMSON, M.D. • STATK HKAI.TH OI-IICKR pp YVTJ fj
April 14, 1995
Charles King, RPM
U.S. Environmental Protection Agency
Region IV, SSRB
345 Courtland Street, NE
Atlanta, Georgia, 30365
Dear Mr. King,
I appreciate the opportunity to review the Draft Record of Decision for Operable Unit
#3 for the Ciba-Geigy Corporation Chemical Superfund Site, CERCLIS No. ALDOO1221902.
The Alabama Department of Public Health (ADPH) concurs with the selected remedy
(Alternative No. 3-Treatment of Excavated Soils Combined with In-Situ Bioremediation) for
Operable Unit #3. ADPH feels that this method is both protective of human health and the
environment.
If you have questions regarding our views of any of the selected remedies, please call
me or Brian J. Hughes, Ph.D., at (334)613-5347.
Sincerely,
Neil Daniell
Geologist
Risk Assessment Branch
/nd
cc: Richard Kauffman
Administrative Offices: Normandalc Mall, 572 K. Patron Avenue, Montgomery, Alabama 36111
Mailing Address: 434 Monroe Street, Montgomery, Alabama 36130-3017
------- |