United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R04-93/152
September 1993
x°/EPA Superfund
Record of Decision:
Stauffer Chemical, AL
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R04-93/152
3. Recipient's Accession No.
Title and Subtitle
SUPERFUND RECORD OF DECISION
Stauffer Chemical, AL
Third Remedial Action
5. Report Data
09/17/93
6.
7. Authors)
8. Performing Organization Rept. No.
9. Performing Organization Nam* and Address
10 Project Taskwork Unit No.
11. Contract(C)orGrant(G)No.
(C)
12. Sponsoring Organization Nam* and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/800
14.
15. Supplementary Notes
PB94-964024
16. Abstract (Limit: 200 words)
The 650-acre Stauffer Chemical site is an active agricultural chemicals manufacturing
plant in Mobile County, Alabama. Land use in the area is predominantly industrial,
with a wetlands area located onsite. The 650-acre wetland area, known as Cold Creek
Swamp, is located in the northeastern section of the Stauffer Chemical Superfund site.
In addition, the site lies adjacent to and drains into the Mobile River. From 1953 to
present, the Stauffer Chemical Company has operated two adjacent manufacturing plant
areas, the multi-product LeMoyne Plant and the Cold Creek Plant. In 1953, the LeMoyne
Plant began operations of a retort carbon disulfide plant, then subsequently by a
reactor carbon disulfide plant in 1956. Several other facilities were added, including
a sulfuric acid plant in 1957; a carbon tetrachloride plant in 1963; a caustic chlorine
plant in 1964; and a Crystex (a proprietary sulfur compound) plant in 1974. In 1987,
Akzo Chemicals acquired the LeMoyne property and continues to operate all of these
chemical processes except the caustic/chlorine process, which was discontinued and
dismantled. The Cold Creek Plant has been in operation since 1966 by Zeneca Inc., and
over the past 20 years a variety of agricultural chemicals has been manufactured at the
plant. From 1965 until 1979, a portion of the LeMoyne site also was operated by Halby
Chemicals, then by Witco, Inc., to manufacture dye chemicals. In the 1970s, Stauffer
(See Attached Page)
17. Document Analysis a. Descriptors
Record of Decision - Stauffer Chemical,
Third Remedial Action
Contaminated Media: sediment, sw
Key Contaminants: metals (mercury)
b. Identlfiers/Open-Ended Terms
c. COSATI Reid/Group
AL
18. Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Page)
None .
21. No. of Pages
74
22. Price
(See ANSI-Z39.18)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/RO4-93/152
Stauffer Chemical, AL
Third Remedial Action
Abstract (Continued)
and the State identified ground water contamination in both onsite and offsite wells.
Throughout the 1970s, observation wells were installed to monitor contamination in ground
water. From the early to mid 1970s, improvements and waste-handling modifications were
made at the site, including closure of unlined wastewater ponds; construction of lined
wastewater ponds; and RCRA-compliant closure with capping of two onsite landfills, which
contained herbicides and pesticides. Past waste disposal practices from these two chemical
manufacturing areas have led to contamination of the Cold Creek Swamp wetlands area. In
the 1980s, three interceptor wells accompanied by an air stripper were installed on the
LeMoyne property, and in 1982, the State required Stauffer Chemical to install monitoring
wells around the LeMoyne landfill. Data obtained from these wells led to EPA's
identification of eighteen source waste areas to be handled under CERCLA. The wetland has
been divided into two areas for remediation: the Upper Arm Swamp Zone and the Transition
Zone. A 1989 ROD addressed surficial ground water contamination at the site, as OU1.
Another 1993 ROD addresses the 18 source areas, as OU2. A future ROD will address part of
the contamination of the Mobile River, as OU4. This ROD addresses contamination of Cold
Creek Swamp, as OU3. The primary contaminant of concern affecting the sediment and
surface water is mercury, a metal.
The selected remedial action for this site includes excavating approximately 80,000 yd^ of
mercury-contaminated sediment to a depth of 2 feet; capping the Upper Arm Swamp Zone using
a RCRA-compliant multi-layer cap; creating a new stream channel to divert the surface
water flow and by-pass the Upper Arm Swamp Zone; consolidating the contaminated sediment
from the Transition Zone in the Upper Arm Swamp Zone, prior to capping; clearing and
removing 5 acres of selected wooded areas; backfilling and revegetating the excavated
areas of the Transition Zone; restoring affected wetlands; conducting long-term monitoring
of the entire wetland; and implementing institutional and engineering controls, including
building up the existing levees using clean fill sediment between Cold Creek Swamp and the
Mobile River. The estimated present worth cost for this remedial action is $17,740,000.
PERFORMANCE STANDARDS OR GOALS:
Cleanup levels for Cold Creek Swamp are focused on the uptake of mercury into the biota.
A target level of 0.5 mg/kg mercury in whole bodies of fish and a standard of 1.1 mg/kg
mercury in tissue of upper tropic mammals have been established.
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RECORD OF DECISION
SUIIUARY OF REMEDIAL ALTERNATIVE SELECTION
STAUFFER CHEMICAL (LEMOYNE PLANT) SUPERFUND SITE
STAUFFER CHEMICAL (COLD CREEK) SUPERFUND SITE
OPERABLE UNIT IB-COLD CREEK SWAMP
MOBILE COUNTY, ALABAMA
PREPARED BY
U. 5. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GEORGIA
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DECLARATION
Of th*
RECORD OF DKCISIOH
OPERABLE DirXT NO. 3-COLD CKSEK SWAMP
SITE NAME AND LOCATION
Stauffer Chemical (LeMoyne Plant) Superfund Site
Stauffer Chemical (Cold Creek Plant) Superfund Site
Mobile County, Alabama
STATEMENT OF BASIS AND PURPOSE
This decision document (Record of Decision), presents the selected
remedial action for Cold Creek Swamp (OU3) for the Stauffer Chemical
(LeMoyne Plant) Superfund Site and the Stauffer Chemical (Cold Creek
Plant) Superfund Site/ Mobile County, 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 Stauffer
Chemical (LeMoyne Plant) Superfund Site and the Stauffer Chemical
(Cold Creek Plant) Superfund Site ('the Site' or -the Sites').
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
Stauffer Chemical Superfund Site. In accordance with 40 Part CFR
300.430, as the support agency, ADEM has provided input during this
process. The State of Alabama has concurred with the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances (pollutants or
contaminants) from the Stauffer 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 third of four at the Stauffer Sites.
Operable unit one was enumerated by a Record of Decision that was
signed by EPA on September 27, 1989. Operable unit two addressed the
migration of contaminants present in the surficial aquifer at the
Site. Operable unit three, which is enumerated by this Record of
Decision, addresses contamination at the Site in Cold Creek Swamp.
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The major components of the selected remedy for Cold Creek Swamp,
operable unit three, include:
• Implementation of multimedia capping on the Upper Arm Swamp Zone
with surface water diversion. The cap will consist of clean soil,
a compacted clay layer, a high density polyethylene gas-venting
layer, a drainage layer, and a soil revegetation layer.
• Sheet piling constructed in two cross-sectional cells as an in-
stream barrier to isolate the Upper and Middle Swamp Zones.
• Creation of wetlands using native species in the new surface water
diversion channel as mitigation of the wetland area destroyed by
the capping of the Upper Arm Swamp Zone.
• Excavation of contaminated soil from the Transition Zone and
disposing of it in the Upper Arm Swamp Zone before capping. The
actual extent of excavation will be determined during the Remedial
Design phase.
• Revegetation of the Transition Zone and restoration to a wetland
status.
• Annual monitoring of the entirety of Cold Creek Swamp for 10 years
after remedial action is completed.
• Long-term monitoring to assess the long term effectiveness of
capping as a containment action.
• Institutional controls including building up of the levees between
Cold Creek Swamp and the Mobile River to limit the exchange of
contaminants to the river. Posting of 'No Fishing" and "No
Hunting" signs are also required.
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. Finally, it is determined that this remedy maximizes
long-term effectiveness.
However, because treatment of the principle threats of the Sites was
not found to be practicable, this remedy does not satisfy the
statutory preference for treatment as a principle element.
Because this remedy will result in hazardous substances remaining
onsite, a review will 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 .
PATRICK M. TOBIN, ACTING REGIONAL ADMINISTRATOR . .DATE
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TABLE OF CONTENTS
1.0 Site Location and Description 1
2 .0 Site History and Enforcement Activities 2
3 .0 Highlights of Community Participation 6
4.0 Scope and Role of Operable Units 7
5.0 Summary of Site Characteristics 8
5.1 Geology, Physiography, Soils, Sediments 8
5.2 Site Hydrology 10
5.3 Natural Resources 12
5.4 Biota Observations 13
6 . 0 Summary of Site Risk 15
6.1 Chemicals of Concern 15
6.2 Human Health Risk 16
6.3 Ecological Risk 17
6.4 Cleanup Levels 19
7.0 Description of Alternatives for the Upper Arm Swamp Zone 20
7 .1 Alternative No. 1 - No-Action 20
7.2 Alternative No. 2 - Capping/Surf ace Water Diversion..... .20
7.3 Alternative No. 3 - Excav./Onsite Treat/Offsite Disp 22
7.4 Alternative No. 4 - Excav./Onsite Treat/Onsite Disp 24
7.5 Alternative No. 5 - In-Situ Solidification/Stabilization.24
8.0 Description of the Alternatives for the Transition Zone 25
8.1 Alternative No. 1 - No-Action 25
8.2 Alternative No. 2 - Excav. Var./Haul to Upper
Arm 25
8.3 Alternative No. 3 - Excav. Var./Onsite Disposal 25
8.4 Alternative No. 4 - Excav. Var./Offsite Disposal 27
8.5 Alternative No. 5 - Capping With Soil 27
8.6 Alternative No. 6 - Capping with Asphalt 27
8.7 Alternative No. 7 - Capping with Multi-layer 27
9.0 Summary of the Comparative Analysis of Alternatives for the
Upper Arm Swamp Zone 29
9.1 Overall Protection of Human Health and the Environment.. .30
9.2 Compliance With ARARs 30
9.3 Long-Term Effectiveness 40
9.4 Reduction of Toxicity, Mobility or Volume 40
9.5 Short-Term Effectiveness 41
9.6 Implementability 41
9.7 Cost 42
10.0 Summary of Comparative Analysis of Alternatives for the
Transition Zone 42
10.1 Overall Protection of Human Health and the Environment..42
10.2 Compliance With ARARS 48
. 10.3 Long-Term Effectiveness 48
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10'.4 Reduction of Toxicity, Mobility, or Volume By Treatment .49
10.5 Short-Term Effectiveness '. 49
10.6 Implementability 49
10.7 Cost 50
11.0 State Acceptance 51
12.0 Community Acceptance 51
13.0 Summary of Selected Remedy 51
14.0 Statutory Determination 52
14.1 Protective of Human Health and the Environment 53
14.2 Attainment of ARARs 53
14.3 Cost Effectiveness 59
14.4 Utilization of Permanent Solutions 59
14.5 Preference for Treatment as a Principal Element 59
15.0 Documentation of Significant Changes 60
Appendix A - Responsiveness Summary 61
Appendix B - Concurrence Letters 62
Appendix C - Statement of Findings 63
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LIST OF TABLES
Table 5-1 Concentrations of Mercury in Collected Biota 14
Table 6-1 Exposure Pathway Assumptions 17
Table 7-1 Comparison of Alternatives in the Upper Arm Swamp Zone. .23
Table 8-1 Comparison of Alternatives in the Transition Zone 26
Table 8-2 Remedial Action Alternatives in the Transition Zone 28
Table 9-0 Breakdown of Evaluation Criteria 29
Table 9-1 Summary Comparison of Alternatives for the Upper Arm
Swamp Zone 32
Table 10-1 Summary Comparison of Alternatives for the Transition
Zone 43
Table 11-1 Federal ARARs for Cold Creek Swamp 54
Table 11-2 State ARARs for Cold Creek Swamp 57
Table 11-3 To-Be-Considered Documents for Cold Creek Swamp 58
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LIST OF FIGURES
Figure 1-1 Area Map for Mobile, Alabama 1
Figure 2-1 Map of Plant Site 3
Figure 3-1 Site Map for the Stauffer Chemical Cold Creek Site 7
Figure 5-1 Mercury Concentrations (0-1 ft) throughout the Site.... 11
Figure 5-2 Vegetative Communities 13
Figure 7-1 Criteria for Evaluating Remedial Alternatives 21
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Stanffer Chemical (LeMoyne Plant) SuperftatdSit*
1.0 SITE LOCATION AND DESCRIPTION
The Stauffer Chemical (LeMoyne Plant) and Stauffer Chemical (Cold
Creek Plant) Superfund Sites are located in Mobile County, on Highway
43, in Axis and Bucks, Alabama, approximately 25 miles north of the
city of Mobile. Since the LeMoyne and Cold Creek Sites are adjacent
to one another, their remedial activities are being completed
.together; therefore, the LeMoyne and Cold Creek Sites are often
referred to as the Stauffer Superfund Sites.
Cold Creek
SwempSHe
Figure 1-1
Location of Area Map
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Cold Creek Swamp is located in the northeast section of the Stauf fer
Superfund Sites. Cold Creek Swamp encompasses approximately 650
acres situated between U.S. Highway 43 to the west and the Mobile
River to the east. The wetland is bounded by the Alabama Power
Company Barry Steam Generating Plant discharge canal to the
northeast, the Mobile River to the east, and the manufacturing
facilities to the south and west. While this area is an industrial
corridor, a large portion of the land is undeveloped, particularly in
the bottomland areas. The surrounding area is sparsely populated and
consists primarily of bottomland hardwoods and other wetlands. It is
situated along the Mobile River, approximately 10 miles south of the
confluence of the Tombigbee and Alabama rivers and 20 miles north of
Mobile Bay. The Mobile River in Mobile County is an important water
source for river barge transportation, as well as other industrial,
agricultural, and recreational uses. Other water supply sources in
the Site vicinity include wells, springs, and ponds. Surrounding
land use in the immediate vicinity of Cold Creek Swamp is
predominately industrial, related to chemical processing and
electrical power generation. However, some small, residential
communities are located within a three mile radius.
Cold Creek drains the wetland, flowing generally east through the
wetland and ultimately discharging to the Mobile River. The
uppermost portion of the wetland is located on the LeMoyne and Cold
Creek plant property and is drained by an unnamed tributary to Cold
Creek. See Figure 2-1 for a map of the study area addressed in this
ROD.
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
Stauffer Chemical Company previously owned and operated a multi-
product chemical manufacturing plant at LeMoyne, Alabama, and an
agricultural chemical facility at the adjacent Cold Creek Site. The
LeMoyne Site was acquired by Akzo Chemie America (now Akzo Chemicals,
Inc.) in 1987. The Stauffer (LeMoyne Plant) began operating in 1953
with a retort carbon disulfide plant followed by a reactor carbon
disulfide plant in 1956. Several other facilities were subsequently
added and include a sulfuric acid plant (on line in 1957), a carbon
tetrachloride plant (1963), a caustic/chlorine plant (1964), and a
Crystex* (a proprietary sulfur compound) plant (1974). The
caustic/chlorine process has since been discontinued and dismantled.
Akzo continues to operate all other processes mentioned above.
The Cold Creek Plant has been in operation since 1966 at which time
it was purchased by ICI Americas, Inc., from Stauffer. ICI Americas
Inc., has since been renamed Zeneca, Inc. This facility has also
expanded its operations over the past 20 years and has manufactured,
and continues to manufacture, a variety of agricultural chemicals,
including thiocarbamates. Halby Chemical Company (later part of
Witco, Inc.) also operated a facility from approximately 1965 to 1979
on a leased section of the LeMoyne property. Witco, Inc., purchased
the Halby Chemical Company facility in 1974 and continued to
manufacture dye chemicals, including sodium hydrosulfide, until 1979.
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Figure 2-1 Map of Cold Creek Swamp
The major contaminant believed to have come from these operations is
thiocyanate.
Stauffer and ADEM discovered groundwater contamination in both on-
site and off site wells in the early 1970's. To monitor contamination
in groundwater, Stauffer installed twenty-one monitoring wells in
1973. By 1977, water quality had deteriorated substantially and
seven observation wells were placed at the southern property line of
the LeMoyne plant. The Alabama Water Improvement Commission (AWIC),
predecessor to today's Alabama Department of Environmental Management
(ADEM) , approved the installation of three interceptor wells
accompanied by an air stripper on the LeMoyne property in late 1980.
Over the years, several improvements and waste-handling modifications
were made including the construction of lined wastewater ponds and
the closure of some old unlined ponds. In 1975, the unlined landfill
located one mile east of the LeMoyne plant containing 11,000 to
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12,000' tons of brine muds, plant refuse, used samples, and absorption
oil was closed using an impermeable membrane cap and side-wall liner
under the direction of AWIC. Improvements made at the Cold Creek
plant in 1974 included closure of the Cold Creek North and South
Landfills with geomembrane caps and side-wall liners. These
landfills contained a variety of herbicides and pesticides.
Several wastewater ponds were closed under the direction of AWIC, and
the use of clay-lined ponds has ceased. Several membrane-lined ponds
which are currently active were installed during the 1970's to
replace the clay-lined ponds.
At present, the Sites contain ten (10) closed or inactive wastewater
ponds and four active ponds near the wetland. The four (4) active
ponds are membrane-lined and monitored regularly. Of the ten (10)
inactive ponds, six (6) are closed and covered. A wastewater
treatment pond associated with the old carbon tetrachloride plant is
lined and contains approximately 1900 yd3 of sulfur sludge. A brine
mud pond associated with the chlorine plant was originally a RCRA
facility, but the contents have since been delisted from status as a
hazardous waste and the pond has been closed. A newer brine mud pond
which was permitted in conformance with RCRA standards was recently
closed and closure documentation has been submitted to ADEM for
approval.
The Alabama Department of Public Health conducted an assessment of
the Site in 1982 in response to submissions made by Stauffer to the
House Committee on Interstate Commerce (the Eckhardt Study).
Additional monitoring wells were installed around the LeMoyne
Landfill based on the advice of ADPH. Data obtained from these wells
formed the basis for the NPL listing of both Sites in September of
1983. The Hazard Ranking Score (HRS) for the Stauffer Chemical Cold
Creek Site was 46.77. Application of EPA's HRS to the Stauffer
Chemical LeMoyne Site yielded a score of 32.34.
On November 21, 1984, EPA issued a Notice Letter and Information
Request to Stauffer for the execution of a Remedial
Investigation/Feasibility Study (RI/FS) at the Stauffer Chemical Cold
Creek Site. On November 23, 1984, EPA issued to Stauffer a Notice
Letter and Information Request for the preparation of a RI/FS at the
Stauffer Chemical LeMoyne Site. Stauffer expressed its interest in
conducting the RI/FS in a letter dated December 21, 1984. Under a
contract with EPA, Camp, Dresser, and McKee, Inc., performed
preliminary sampling in May 1985 to assist in preparing a work plan
for the RI/FS. Stauffer and EPA entered into an Administrative Order
on Consent (AOC), Docket No. 86-04-C, on January 21, 1986. Pursuant
to the AOC, Stauffer agreed to conduct the RI/FS at both Sites and to
reimburse EPA for all costs of response and oversight incurred by the
United States. Subsequent to the effective date of the AOC, ICI
Americas, Inc. (presently, Zeneca), purchased the LeMoyne and Cold
Creek plants. Shortly thereafter, Akzo purchased the LeMoyne plant
from ICI Americas, Inc. Akzo and ICI Americas, Inc., continued the
RI/FS to completion. These potentially responsible parties (PRPs)
completed the RI in July 1988 and the FS in January 1989.
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On July 11, 1989, EPA issued a Proposed Plan for remedial activities
which addresses groundwater contamination at the Sites. EPA then
issued Special Notice Letters to Akzo and ICI Americas, Inc., on July
20, 1989, relating to the Remedial Design/Remedial Action (RD/RA) for
groundwater remediation. EPA executed a Record of Decision (ROD) on
September 27, 1989. Under the provisions of the ROD, EPA established
three Operable Units. Operable Unit 1 (OU1) addresses groundwater
and contaminant sources, Operable Unit 2 (OU2) addresses source
units, and Operable Unit 3 (OU3) refers to the Cold Creek Swamp. The
Consent Decree (CD) for the conduct of the RD/RA for OU1 was lodged
on April 25, 1990. At present, the PRPs are operating a groundwater
recovery and treatment system which includes interceptor wells with
flow rates from 325 to 420 gallons per minute (gpm) .
The on-site sources of contamination at both Sites are designated as
OU2. The September 27, 1989, ROD for OU1 identified nine (9) Solid
Waste Management Unit (SWMU) Areas. These SWMU Areas include twelve
(12) separate SWMUs. Subsequently, in March 1991, Region IV's RCRA
Branch conducted a RCRA Facility Assessment at the Akzo facility (the
LeMoyne plant) and identified a total of 139 SWMUs and fourteen (14)
Areas of Concern (AOCs) . Of the 139 SWMUs, EPA only identified eight
(8) as requiring a full investigation. During a meeting on March 13,
1992, and in a letter dated May 1, 1992, EPA informed the PRPs that a
RI/FS must be conducted for OU2 (on-site sources) . EPA's authority
to require this RI/FS was based on Section VI, Paragraph 1 of the
AOC. Akzo and ICI Americas, Inc. (Zeneca), requested that EPA
include less than the entire 139 SWMUs in OU2 and that EPA handle the
remaining SWMUs under the Corrective Action portion of Akzo's RCRA
permit. Based on an agreement between the CERCLA and RCRA branches,
Region IV included six (6) additional SWMUs in OU2. The addition of
these six (6) SWMUs to the twelve (12) SWMUs identified in the ROD
for OU1 brings the total number of SWMUs in OU2 to be handled under
CERCLA to eighteen (18).
An August 6, 1992, EPA letter documents a consensus reached between
EPA and the PRPs for a three-phased approach which has been
implemented for the RI/FS Work Plan for OU2. On December 29, 1992,
EPA approved a Decision Document which was prepared to assess
available information on eighteen (18) SWMUs in OU2, to determine the
appropriate course of action at these SWMUs, and to make
recommendations for addressing source contamination.
In a letter dated May 4, 1990, EPA notified the PRPs that a
determination had been made that pursuant to Section VT, Paragraph I
of the AOC, supplemental investigatory work and/or engineering
evaluation was necessary for OU3. Akzo and Zeneca responded in a May
22, 1990, letter stating that the PRPs were willing to conduct the
supplementary work. The additional study (RI/FS) was conducted to
better define the nature and extent of contamination and potential
human health and ecological risk existing in the wetland. In
addition to identification of the hazardous substances present in
sediments and surface water and the characterization of risk posed by
the presence of these contaminants, the additional study also
included extensive biological sampling, including finfish, herptiles,
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and invertebrates from the wetland and other locations determined to
represent background, and an analysis of these organisms for whole-
body mercury tissue concentration.
On May 25, 1993, EPA issued a 'Notice of Decision Not To Use Special
Notice Procedures" to the potentially responsible parties (PRPs) for
the Stauffer Sites, Akzo and Zeneca, to the PRP for the Ciba-Geigy
Site, Ciba-Geigy Corporation, and to the PRP for the Olin Corporation
Site, Olin Corporation. The notice letter informed the PRPs,
including those for the Stauffer Sites, of the designation of a
length of the Mobile/Tombigbee river system from just north of the
Ciba-Geigy Site to just south of the Stauffer Chemical LeMoyne Site
as Operable Unit 4 for the Stauffer Sites, Operable Unit 5 for the
Ciba-Geigy Site, and Operable Unit 3 for the Olin Corporation Site.
EPA intends to conduct an initial, yet comprehensive, RI to determine
the areal extent of contamination in the river system due to the
release of hazardous substances and pollutants or contaminants from
the four NPL Sites. EPA Region IVs Environmental Services Division
has prepared a draft Work Plan.
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION FOR COLD CREEK SWAMP (OU3)
An availability session was held on February 6, 1991, in the
Toulminville Public Library at the start of field work for the RI for
Cold Creek Swamp. Two subsequent availability sessions were held on
April 21 and 22, 1992, at the Dead Lake Marina and Little Rock
Baptist Church, respectively. Both are located in Axis, Alabama.
These subsequent availability sessions were to update the community
on activities through the RI/FS.
The main branch of the Saraland Public Library at 111 Saraland Loop,
Saraland, Alabama, was chosen as the local information repository for
the Site. Saraland Public Library will be the information repository
for six months at which time it will be moved to the new Satsuma
Library. The public comment period on the proposed plan preceding
this ROD (OU3) was held June 15, 1993, through July 14, 1993. A
public meeting was held on June 29, 1993, where representatives from
EPA answered questions from approximately 50 people regarding the
Site and the proposed plan under consideration.
The administrative record, including the RI/FS Report and the
Proposed Plan, was available to the public at both the information
repository and at the EPA Region IV Library at 345 Courtland Street
in Atlanta, Georgia. The notice of availability of these documents
was published in the Mobile Register Press on June 15, 1993, and June
24, 1993. EPA received numerous oral and written comments during the
comment period. Responses to the significant comments received are
included in the Responsiveness Summary, which is part of this ROD,
and is designated Appendix A.
This decision document presents the selected remedial action for
operable unit three of the Stauffer Sites, chosen in accordance with
CERCLA, as amended by SARA and to the extent practicable, the NCP.
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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.
Figure 3-1 Map of the Source Areas of OU2
4.0 SCOPE AND ROLE OF OPERABLE UNITS
EPA has organized the work at this Super fund Site into four operable
units (OUs). These units are as follows:
OUl Contamination of the aquifer emanating from the Site. A
Record of Decision was issued on OUl in September, 1989.
A groundwater pump and treat system is currently in place.
Three groundwater extraction wells are in operation and
three more will be on line in 1993.
OU2 Contamination of the source areas at the Site. This
addresses 18 waste disposal areas including the landfills,
the active ponds, and the Old Carbon Disulfide Wastewater
Treatment Pond. An RI/FS is currently underway to
determine the extent of contamination and evaluate
possible cleanup alternatives.
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OU3 Contamination of Cold Creek Swamp. Addressed by this
Record of Decision.
OU4 Contamination of the Mobile River. An EPA lead
investigation is underway to determine the extent of
contamination in the Mobile River from releases from the
Stauffer Superfund Sites.
This Record of Decision addresses Cold Creek Swamp (OU3). The
wetland received contaminated wastewaters from the former operations
at the manufacturing facilities. A June 1992 Supplemental Remedial
Investigation Report documents the details of the study of
contamination in the wetland. A November 1992 Supplemental
Feasibility Study Report and the March 1993 Supplemental Feasibility
Study Report Addendum submitted by Akzo Chemicals Inc./Zeneca Inc.,
documents the development, screening, and detailed evaluation of
potential alternatives and risk posed by the contaminants as they
relate to the Site. Furthermore, EPA has issued a December 10, 1992,
caveat to the RI Report and a June 3, 1993, caveat to the FS Report.
Based upon this evaluation, EPA will determine which alternative or
combination of alternatives which will achieve the CERCLA remediation
objectives.
5.0 SUMMARY OF SITE CHARACTERISTICS
This is a summary of the major Site characteristics presented in the
RI/FS Study, the BCM Biota Study, and the Supplementary RI/FS Study.
In 1990, EPA, based upon comments from the U.S. Fish and Wildlife
Service and the National Oceanic and Atmospheric Administration on
the original 1988 RI Report, EPA required that additional studies be
conducted within Cold Creek Swamp to better define the nature and
extent of contamination and potential human health and ecological
risk. In response to EPA, Akzo Chemicals Inc./ Zeneca Inc. initiated
a Supplementary RI/FS. It included: the sampling of surface water
within the wetland; collection of sediment samples at various depths
at over one hundred locations within the wetland; and extensive
biological sampling. Results of receptors of concern screening and
the preliminary ecological exposure model were used to scope field
activities focusing on biota collection/analysis. Biota samples
included finfish, herptiles, and invertebrates from the wetland and
reference locations which were analyzed for whole-body mercury tissue
concentration. The final step in the RI process was development of
baseline human health and environmental risk assessments and
examination of migration of contaminants.
5.1 GEOLOGY/PHYSIOGRAPHY/SOILS/SEDIMENTS
The results of the RI led to the following findings and conclusions:
The Site lies in the Southern Pine Hills Section (Piney Meadows
Subsection) of the East Gulf Coastal Plain Physiographic
Province. Within the Southern Pine Hills Section of the Coastal
Plain, the underlying sedimentary units are overlain by Miocene
8
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es'tuarine deposits consisting of interbedded sands and clays, and
in some areas the younger Pliocene Citronelle Formation which
generally consists of sand and gravel. These deposits are in
many areas overlain and incised by younger Pleistocene- and
Holocene-age alluvial deposits, with deposition occurring from
long-term sedimentation from several north/south-tending streams
and rivers.
The Site is underlain by low river terrace and alluvial deposits
that are approximately 110 to 130 feet thick. The deposits
consist of generally clean, unconsolidated, fine to very coarse-
grained sands that contain some interbedded, discontinuous clayey
seams and some gravelly zones. The upper sands have moderate to
low permeability.
Cold Creek Swamp is a flat, low lying area on the west bank of
the Mobile River. The Cold Creek drains the wetland, flowing
generally west to east through the wetland and ultimately
discharging to the Mobile River. The uppermost portion of the
wetland (Upper Swamp, Zone I) is located on the LeMoyne and Cold
Creek Plant property and is drained by an unnamed tributary to
Cold Creek. It is characterized by level to undulating
topography with several pools and minimal stream flow through
most of the year. The wetland is relatively narrow and heavily
wooded in the Middle Swamp (Zone II) until it reaches two. power
line cuts. At the power line cuts, the wetland broadens and
supports dense woody vegetation (Lower Swamp, Zone III). Cold
Creek flows along the south and southeastern edge of the wetland
and discharges into the Mobile River approximately 1/2 mile
downstream of the Alabama Power Company Barry Steam Generating
Plant cooling water discharge canal. An unnamed tributary to
Cold Creek discharges to the wetland in the vicinity of the power
line cuts. (Figure 2-1)
Surface elevations in the wetland range from highs of about 30
feet above mean sea level (MSL) in the Upper Swamp (Zone I) at
the two plant Sites, to lows of approximately 6 feet MSL in the
Lower Swamp (Zone III) along the Mobile River. Much of the
Middle and Lower Swamp, with elevations of less than 10 feet MSL,
become flooded by overflow from the Mobile River during Spring
storm events.
The two main soil associations within Cold Creek Swamp are the
Izagora-Bethera and the Dorovan-Levy. The Izagora-Bethera
Association is most prominent in the narrow western portion of
the Site (Zones I & II) and characterized by loamy marine
sediments and poorly drained clayey soils. The Dorovan-Levy
Association is the dominant soil association found in the broad
eastern portion (Zone III) of Cold Creek Swamp. This association
consists of very poorly drained soils located in depressional
wetlands and bottoms along the Mobile River, and is dissected by
meandering streams.
-------
• Examination of the Supplementary RI soil/sediment sampling data
indicates mercury is the Chemical of Concern. Other potential
Chemicals of Concern that were identified include thiocarbamates,
aluminum, cadmium, copper, and zinc. The extent of contamination
is restricted primarily to the upper 1-3 ft of the soil/sediment.
Examination of the sample analyses indicated that the mercury
seems to be bound to the soil/sediment particles in the upper 3
feet. Methyl mercury is extremely bioaccumulative resulting in
uptake in biota and effects in the upper trophic levels through
biomagnification.
• The two locations of major mercury concentrations are in the
Upper Arm Swamp Zone located near Zeneca, Inc., and at the
transition from the Middle to Lower Swamp (Transition Zone) where
Cold Creek bends and intersects the power lines.(Figure 3-1)
• Surficial soil/sediment samples collected in the Supplementary RI
reinforce previous data collected for soil/sediment and soil
boring samples with regard to mercury location. The highest
mercury concentrations ranged from 7560 mg/kg in the Upper Arm
Swamp Zone to 632 mg/kg in the Transition Zone at the power
lines.
5.2 SITE HYDROLOGY
• Surface water runoff from approximately 1,100 acres, including
the western part of the LeMoyne Plant property, a portion of the
north-central part of the adjacent Courtaulds Fibers property,
and a part of the adjacent Route 43 right-of-way, flows through
the drainage channels within the LeMoyne Plant, ultimately
discharging to an unnamed tributary to Cold Creek at the head of
the Upper Arm Swamp Zone. This stream flows generally north-
northwest through a series of ponds and pools within the Upper
Arm Swamp Zone. Flow from another unnamed tributary joins Cold
Creek from the east in the Middle Swamp west of the v;estern power
line right-of-way. At this point, Cold Creek then flows
southeasterly to a series of ponds in the Lower Swamp. Discharge
channels emanating from the lowest pond in the Lower Swamp cut
through the shoreline levee at no less than two points where the
wetland meets the Mobile River. Water flow through the wetland
is a function of the stormwater runoff and the fluctuating Mobile
River stages. Under static conditions there is generally no flow
and the wetland is a series of ponds and pools. Much of the
Lower and Middle Swamp become flooded by overflow from the Mobile
River during spring storm events.
• Surface water samples were collected from two locations in the
unnamed tributaries to Cold Creek. The locations were not within
the limits of the wetland and were intended as reference
conditions. The only compounds detected in these samples were
mercury at 0.0002 mg/L and zinc at 0.31 mg/L. No priority
pollutants, organics, or polychlorinated biphenyls (PCBs) were
detected in these samples. Methyl mercury was detected in the
10
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wetland sediments. While part of the mercury is in the form of
the relatively insoluble sulfide, a portion is in a bioavailable
form.
Figure 5-1 Mercury Concentrations (0-1 ft)
Surface water samples collected during the supplemental RI did
not contain any volatile or semi-volatile organic compounds,
pesticides, PCBs, thiocarbamates, or thiocyanate above detection
levels. The observed compounds found to exceed water quality
criteria for toxicity to aquatic organisms in the surface water
samples were metal concentrations of mercury, silver, and zinc.
Of these only mercury was considered to represent a potential
risk to ecological receptors but not to human health based on the
established exposure scenarios.
The Site is located on the Mobile River Valley water-table
aquifer which is recharged through infiltration from the Mobile
River, Cold Creek Swamp and associated wetlands, and rainfall.
11
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This aquifer is the principal source of water for users within
the Valley. Existing municipal and industrial water supply wells
in this aquifer typically yield 470 to 846 gallons per minute
(gpm) , with specific capacities of 6 to 73 gpm per foot of
drawdown. The background water quality is potable, with low
total dissolved solids and iron.
• Prior to industrialization the direction of groundwater flow was
eastward toward the Mobile River. The water table varied from
0-20 ft below ground level depending on the topography.
Presently, the direction of flow is toward the south-southeast
due to local influence of pumping at Courtaulds Fibers and from
interceptor wells at the southern limits of the LeMoyne Plant.
Groundwater usage within the Site area is believed to be limited
to the upper aquifer above a clay layer.
• Groundwater is used for industrial processes at several of the
surrounding plants. There are two groundwater production wells
at the Cold Creek Plant and four groundwater production wells at
the LeMoyne Plant. There are two wells used for in-plant
drinking water supply at the Cold Creek Plant and no wells used
for drinking water at the LeMoyne Plant. These wells are located
on the northwest corner of the Cold Creek Plant, up-gradient of
the wetland site.
• Groundwater samples were collected from five monitoring wells
within and around the wetland at depths varying between 207 and
1,160 feet below ground surface. The ground-water table varied
from 0 to 20 feet below ground level depending on the topography.
Samples were analyzed for priority pollutants, PCBs, metals, and
thiocarbamates. Mercury was detected in several shallow and deep
wells at concentrations at or near the detection limit of
0.00020 mg/1. However, mercury was detected above the target
concentration of 0.0020 mg/1 in one sample.
5.3 NATURAL RESOURCES
• The primary natural resource in the Site vicinity is the Mobile
River. In the vicinity of the Site it is approximately 500 ft
wide with an average depth of 28 ft. Minimum flow is 4800
ftVsec at a flow velocity of over 0.33 ft/sec. The river flows
south, discharging into the Mobile Bay and ultimately the Gulf of
Mexico. The river is heavily used for industrial barge
transportation with a minor component of recreational use. The
Mobile River and the wetland support numerous species of aquatic
and terrestrial wildlife.
• In the Mobile River Basin, soil is a key natural resource. In
the immediate vicinity of the wetland, timber production (cypress
trees and pulp wood) is the only form of agriculture due to the
lowland nature of the area and the development of the surrounding
uplands for industrial use.
12
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The Cold Creek drainage system supports diverse wildlife
habitats, including forest in the Lower Swamp and scrub-shrub
areas, which provide nesting and refuge areas, in the middle of
the upland areas.
Figure 5-2 Vegetative Communities Map
5.4 BIOTA OBSERVATIONS
Initial RI study of biological tissue samples, reported in 1988,
were collected at four locations within the wetland and at one
reference location, and were analyzed for mercury. Levels ranged
from below quantification limits to 3.1 mg/kg based on whole-body
analysis. A subsequent study by BCM, in 1989, collected finfish,
crayfish, and earthworms considered to be representative of the
aquatic community in the wetland. These were analyzed for
arsenic, chromium, copper, lead, mercury, nickel, and zinc. The
study concluded that levels of chromium, copper, mercury, nickel,
and zinc in fish exceeded those of reference levels. Upon
examination of crayfish samples, levels of chromium, copper,
lead, mercury, nickel, and zinc were found to be in excess of
their reference levels. Earthworms also were found to contain
13
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Table 5-1 Concentrations of total mercury detected in tissues of
fish, herptiles, and invertebrates collected from Cold Creek Swamp.
Species
Fish
American Eel
Bluegffl
Bowfin
Brown Bullhead
Chain Pickerel
Common Cup
Golden Shiner
Lake Chubsucker
Largemouth Bass
Longear Sunfish
Redear Sunfish
Redfin Pickerel
Spotted Sunfish
Spotted Gar
Warmouth
Yellow Bullhead
Herpdles/InTertebrates
Amphiuma
Banded Water Snake
Bronze Bogs
Clams
Cottonmouth Snake
Crayfish
Frogs
Leopard nogs
Southern Toad
Trophic Level
Carnivore
Carnivore
Carnivore
Carnivore
Predator
Primary Consumer
Primary Consumer
Primary Consumer
Predator
Carnivore
Carnivore
Predator
Carnivore
Predator
Carnivore
Carnivore
Carnivore
Predator
Carnivore
Primary Consumer
Predator
Primary Consumer
Carnivore
Carnivore
Carnivore
Total Tissue Mercury (mg/kg wet wt)
Background
NS
0.12-0.73
NS
0.04
0.56
0.12
NS
0.17
038-1.5
NS
NS
OM
0.42&0.44
0.42
NS
0.29
NS
NS
0.03&0.06
NS
0.66
NS
NS
0.02&OXM
NS
Upper
Swamp
NS
0.14
0.64
NS
NS
NS
0.29&1.0
NS
030-0.93
NS
0.62
NS
NS
0.69&0.71
NS
NS
0.41
NS
0.73
NS
NS
NS
1.6
NS
0.19
Middle
Swamp
NS
NS
091
NS
0.81&2J
0.82
0.81
NS
1.4
NS
NS
0.65*15
NS
NS
NS
0.71
NS
0.7
054-0.58
0.68
NS
0.95
NS
NS
NS
Lower
Swamp
043
NS
NS
NS
15-35
NS
NS
NS
1.1
1.1&14
NS
0.69&23
NS
NS
058
NS
NS
NS
0.24
NS
05041.6
0.74
0.16
NS
NS
' NS = not sampled
14
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high levels of arsenic, chromium, copper, mercury, and zinc.
Many of the metal concentration levels in the samples were found
to be in excess of their reference levels by more than 200%.
Biota samples of finfish, herptiles, and invertebrates from all
three zones of the wetland, as well as reference locations, were
analyzed for whole-body mercury tissue concentration during the
Supplementary RI, 1990. Based on the analysis, predators
(snakes,spotted gar, large-mouth bass, pickerel) contained
significantly higher concentrations of mercury than consumers
(amphiuma, frogs, toads, bowfin, sunfish, golden shiner,
bluegill, carp, eel); however, primary consumers (clams,
crayfish) could not be distinguished from upper level consumers.
When all tissue samples from all zones of the wetland are
combined and compared with reference mercury tissue
concentrations, it is apparent that wetland biota tissue mercury
concentrations are statistically significantly elevated above
reference. Table 5-1 shows the concentrations of mercury found
in the tissue of fish, herptiles, and invertebrates found in
samples collected in Cold Creek Swamp.
• Threatened and endangered species were determined not to be
utilizing the site, via literature search and site
reconnaissance.
6.0 SUMMARY OF SITE RISK
CERCLA directs EPA 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 determining
whether or not remedial action is necessary and the justification for
performing remedial action.
Based upon the levels of mercury found in the biota of Cold Creek
Swamp, it is found that bioaccumulation of mercury is occurring and
that mercury is available to the Cold Creek Swamp ecosystem. Mercury
concentration values in Cold Creek Swamp far exceed those sediment
concentrations of mercury which would be expected to cause ecological
effects. Furthermore, the mercury levels in fish exceeded
recommended screening levels determined to be protective of avian
(0.1 parts per million, ppm) and mammalian (1.1 ppm) species which
consume them. Actual or threatened releases of hazardous substances
from this site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial
endangerment to public health, welfare, or the environment.
6.1 CHEMICALS OF CONCERN
The pollutants associated with Cold Creek Swamp are believed to be
the result of past disposal practices at the Stauffer Chemical
Company processing facility. Mercury contaminated wastewaters from
15
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the chlorine processing facility at the LeMoyne Plant were previously
discharged into the drainage channel that feeds the Upper Arm Swamp
Zone of Cold Creek Swamp.
Assessment of the data indicated that mercury was the primary
Chemical of Concern (COC) . Other potential COCs that were identified
included thiocarbamates, aluminum, cadmium, copper, and zinc.
Detailed examination of these compounds based upon risk assessment
and mineralogical analyses revealed that mercury was the only
critical COC. The mercury will remain in sediments of the wetland
until it either converts to methyl mercury and accumulates in biota,
releases to overlying surface water, or is physically transported out
of the wetland.
6.2 HUMAN HEALTH RISK
Site-specific exposure risks for human health is determined by the
possibility of incidental oral ingestion, inhalation, or direct
contact. The total excess risk of cancer for potential site exposure
should be maintained within the range of 1 x 10"4 to 1 x 10~6. This
range is equivalent to an increased chance of one additional case of
cancer in 10,000 to 1,000,000. Also, the concentrations of non-
carcinogenic chemicals must be lower than those which can lead to
chronic health effects. For the Cold Creek Swamp Site, the baseline
human health risk assessment indicated that potential human health
exposure did not present unacceptable health risks based on the
anticipated exposure pathways (see Table 6-1).
The anticipated exposure pathway was based upon the scenario that the
conditions at the wetland are not conducive to swimming or wading
activities. Therefore, incidental ingestion of water while swimming
and contact with sediment while wading were considered non-viable
routes of exposure. However, two routes of potential exposure that
were examined were oral ingestion of fish and/or shellfish caught
recreationally within wetland waters and dermal contact with
potentially contaminated water within the wetland during recreational
fishing.
The wetland was characterized as being too dry for much of the year
to support year-round fishing. Land access to the wetland was
limited by posted restrictions for trespassers and the position of
the manufacturing facilities. The only access route entailed
entrance from the Mobile River, a process considered difficult.
Typical fish in the wetland waters were small in size which limited
the ingestible amounts of tissue and thus, the potential for
contamination. With respect to dermal contact with potentially
contaminated water during the course of recreational fishing,
exposure was limited to incidental splashing of water on exposed body
surfaces. Based upon the isolated nature of the wetland and the
limited exposure pathway, the Human Health Risk Assessment did not
indicate that the wetland presents an unacceptable risk.
16
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TABLE 6-1 EXPOSURE PATHWAY ASSUMPTIONS
BOX TO
on TO
Exposure Frequency
6 meals/yr (based on in
estimate of 1 recreational
fish meal per »onth from
Cold Creek Swamp for the
months the wetland ha*
water)
Exposure Frequency
6 tlmes/yr (MB
frequency •• assumed for
recreational fishing)
Exposure Duration
30 years [baaed on the
national upper-bound (90th
percentlie) estimate of
time that people live at
one residence, an EPA
aasumption per the
guidance manual)
Skin Surface Area
- 0.23 •'
Hand* - 0.082 •'
Leg* - 0.55 •'
(1.883 •' (EPA
assumption per guidance
•anual)
Body Height of Fisherman
70 kg (atandard adult
weight, and EPA assumption
per the guidance •anual)
Exposure Time
4 hra/day (expected
duration of flailing
event)
Ingestion Rate
113 grama/men1 [the
average (SOth percentlie)
alze of a fin flah Baal.
baaed on BPA aeauaptiona
In the guidance manual.
Exposure Duration
30 yeara (aame duratic
aa assumed for
recreational fishing)
Averaging Tine
30 yr for noncarcinogenic
effectei 70 yr for
carcinogenic effects (EPA
assumptions per the
guidance manual)
Body Height
70 kg (standard BPA
assumption per the
guidance manual)
Fraction Ingested
1, i.e., entire
fish/shellfish Mil c<
from wetland.
Averaging Time
30 yr for noncarcinogenic
effectai 70 yr for
carcinogenic effects (EPA
assumptions per guidance
H)
Permeability Constants
These are compound-
specific and measure the
amount of the compound
which is absorbed through
each cm* of skin per hour
of exposure. Values will
be obtained from BPA
guidance or the
permeability constant for
water (0.0015 cm/hr) will
be used if no compound-
specific value Is
available (per BPA
guidance manual).
It is important to note that on May 7, 1992, the Mobile County
Department of Health issued a "Fish Consumption Advisory' on Cold
Creek Swamp. The decision to issue this advisory was based on the
findings of the RI, specifically that mercury was detected in fish
samples in concentrations greater than the 1 part per million
standard set by the Food and Drug Administration for fish
consumption. 'No fishing' signs were posted along the wetland.
Again, the assumption in the Risk Assessment was that land access to
the wetland area is limited. Trespassers into the wetland would be
at minimal risk if they were exposed, via occasional fishing, to the
extent estimated in the risk assessment.
6.3 ECOLOGICAL RISK
The finding of the Baseline Ecological Risk Evaluation is that levels
of mercury in Cold Creek Swamp sediments pose a potential risk to
receptors. These levels are above the recommended level protective
17
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of piscivorous bird species, 0.1 ppm (Eisler, 1987), which has been
adopted as a screening value by Region IV.
Mercury concentrations at the Stauffer Cold Creek site are many times
higher than those reported at other mercury contaminated sites. The
highest mercury concentrations ranged from 1600 mg/kg (0-1 ft
sediment interval) and 7560 mg/kg (1-2 ft sediment interval) in the
Upper Arm Swamp Zone to 632 mg/kg (0-1 ft sediment interval) in the
Transition Zone at the power lines. As a comparison, background
mercury concentrations in sediment found in other areas are between
0.01 to 0.2 ppm.
The mercury concentrations in ecological receptors in the wetland
also displayed elevated levels. Carnivorous fish and predatory
herptiles showed the highest mercury levels. These levels are above
the recommended safe limit of 0.1 ppm for ingestion by sensitive
species of birds. Although there are no data indicating mercury
levels in birds, concentrations of this magnitude in food items
utilized by many bird species which forage in the wetland are likely
to result in reproductive impairment. However, 0.1 ppm represents a
screening level for mercury contamination in fish tissue that would
be considered protective of piscivorous (fish-eating) birds. The
findings of the Baseline Ecological Risk Evaluation were that levels
of mercury in the wetland sediment poses an unacceptable risk to
turtles, snakes, and carnivorous fish since their Hazard Indices was
greater than 1. Mercury in the wetland is bioavailable and is
accumulating in the tissues of a variety of organisms in the wetland.
Based upon these findings, an unacceptable ecological risk is present
in Cold Creek Swamp.
The Feasibility Study Report showed that two areas of the wetland are
of particular concern. These areas not only have high levels of
mercury in sediment but the risk assessment shows a potential risk to
biota in the wetland. These areas are the Upper Arm (Upper Arm Swamp
Zone) and the Middle/Lower Swamp Zone (Transition Zone) . The Upper
Arm Swamp Zone is the original point of discharge and remains the
most highly concentrated source area for contamination driven risks
to receptors. The Transition Zone is a sediment depositional area
that receives mercury contaminated sediment from the Upper Arm Swamp
Zone (Figure 2-1). The Baseline Ecological Risk Evaluation predicted
mercury concentrations in organisms throughout the wetland after the
sediments in the Upper Arm Swamp Zone and Transition Zone were
isolated or removed. The concentrations of mercury in fish, turtles,
snakes, alligators, and birds were predicted to fall below levels of
concern if contaminated sediment in these two areas were isolated or
removed. Therefore, remediation of these two areas is predicted to
reduce the exposure of biota to mercury contaminated sediment, and
result in reductions in mercury levels in the tissues of resident
biota.
In addition, there is evidence that an interconnection exists between
Cold Creek Swamp and the Mobile River. Discharge from Cold Creek
Swamp occurs as the river stages recede and the water ponding behind
the levee seeps out through the levee and flows through the outfall
18
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channels from the wetland to the Mobile River. In addition, Cold
Creek flows from the upland area west of the Site through Cold Creek
Swamp and into the Mobile River. The nature of the riverine system
is that sediment and surface water from the river is transported
downstream.
6.4 CLEANUP LEVELS
The cleanup levels for Cold Creek Swamp are focused on the uptake of
mercury into the biota of Cold Creek Swamp. Because of the nature of
mercury in the wetland system and the fact that methylation of
mercury is a constant process and very difficult to measure in
sediment, the measurement of mercury body burdens is the most
accurate method for determining if contaminates in Cold Creek Swamp
are at levels which may adversely affect the ecosystem. Therefore, a
target level of 0.5 ppm mercury in whole bodies of bottom feeders,
carnivorous, and omnivorous fish has been established. These values
are based upon the proposed levels set by EPA's Office of Science and
Technology1. Although this value is based on human health
consumption it can be interpolated for consumption of upper trophic
-level consumers. This value is also consistent with the World Health
Organizations2 level for safety for human health consumption. In
addition, it falls within the range of safety as interpolated from
the literature review of Suzuki, 19793 as cited in Eisler, 1987*
Also, a standard of 1.1 ppm mercury in muscle, kidney, and brain
tissue of upper trophic level mammals has been established. This
standard is based upon a value of safety as interpolated from the
literature review of Eisler (1987).*
It is prudent to note that up to this date no standards have been set
by EPA for safety of sensitive environments. Although there is no
widely accepted level for mercury concentrations in biota tissue,
proposed bench mark numbers range from 0.1 to 1.1 ppm. The values
established above are based upon scientific studies regarding mercury
concentrations and their effects on biota. If standards are
aFish Sampling and Analysis: A Guidance for Issuing Fish
Consumption Advisories. Prepared by the Contaminated Fish Section
of the Office of Science And Technology, February 1993 Draft.
Environmental Health Criteria: Methylmercury. World Health
Organization, Geneva, 1990. pp 10-17, 100-105.
3Suzuki, T. 1979. Dose-effect and dose-response relationships
of mercury and its derivatives. Pages 339-431 in J.O. Nriagu
(ed.) . The biogeochemistry of mercury in the environment.
Elsevier/North-Holland Biomedical Press, New York
4Eisler, R. 1987. Mercury Hazards to Fish, Wildlife, and
Invertebrates: A synoptic review. U.S. Fish and Wildlife Service
Biological Report 85 (1.10). 90 pp.
19
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established by EPA subsequent to this ROD or new information
concerning mercury tissue residues are provided regarding ecological
effects or impacts on the food webs, an amendment or explanation of
significant differences (BSD) may be necessary to incorporate the
established standards.
7.0 DESCRIPTION OF ALTERNATIVES FOR THE UPPER ARM SWAMP ZONE
The following is a description of remedial alternatives evaluated to
provide a range of cleanup options for the Upper Arm Swamp Zone. All
actions presented below will be conducted in a manner that minimizes
impact on wetlands in accordance with federal and state regulations.
Table 7-1 is a comparison of feasible alternatives for the Upper Arm
Swamp Zone.
7.1 ALTERNATIVE No. 1 - No-Action
The NCP requires that "no action* be evaluated to establish a
baseline for comparison. This alternative will involve assessment of
the potential for natural recovery through a long-term monitoring
program with specified performance milestones, including a five year
review. The Upper Arm Swamp Zone sediment contamination will not be
further treated, removed, immobilized, nor reduced.
The monitoring program will require the sampling of the biota and
frequent measurement of the natural sedimentation process. It will
also include evaluation of the impact of storms. Monitoring will
continue for five years at which time a projection as to the length
of time required for the total encapsulation could be made
(approximately 10 to 30 years).
The 30-year total cost of this alternative is estimated to be
$300,000.
7.2 ALTERNATIVE No. 2 - Capping/Surface Water Diversion
Alternative No. 2a: Capping with Surface Water Diversion
This alternative will involve a closure of the contaminated area
(approximately 25 acres) through capping with clean soil taken from
elsewhere onsite. The cap, a 2-ft-thick soil layer with a geotextile
fabric layer underneath, will be constructed over the area of
proposed remediation within the Upper Arm Swamp Zone and will cover
the mercury contaminated sediments in the area. The purpose of the
cap is to minimize exposure of the wetland biota to mercury-
contaminated sediment and to minimize transport to the Lower Swamp by
containing the primary mercury source area in the wetland. A new
stream channel will be created to divert the surface water flow and
by-pass the Upper Arm Swamp Zone.
20
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Sheet piling will be used as in-stream barriers to isolate the Upper
and Middle Swamp. The sheet piling will be used in two cross-sect ions
of the Upper Arm Swamp Zone to create "cells' that will be filled and
to prevent post-remedial action erosion. Capping soil will then be
placed to fill the cells to limit erosion. Finally, reestablishment
of native wetland will be needed in the Upper Arm Swamp Zone. In
addition, a new channel will be cut to divert the creek around the
soil capped Upper Arm Swamp Zone. New wetlands of equivalent
functional values will be created to compensate for those lost in the
Upper Arm Swamp Zone. The extent of the areal limits will be
determined by topography of the Site.
•Overall AtoUetioa of *fc»-»r«-
CRITERIA FOR
EVALUATING
REMEDIAL
ALTERNATIVES
The ROD provide* the
ban* for determining
which alternative
provide* tit? be*f balance
with retpect to the
statutory balancing
criteria in Section 121 of
CERCLA and in Section
300.430 of the NCP. The
major objective of the F8
wa* to develop, tcreen,
and evaluate alternative*
far the remediation of
Operable Unit One at
three at theStavffer Site.
The remedial aUernafivef
9elected from the
screening proce** were
evaluated vting the
following tone evaluation,
criteria: .
ta wtach tJ
or control* beftKfc end
threat* ttuKragii. treatment, '•mgin»mfl-nf
method*. or institutional control*. ,.• ..
A««**»e*
- Woi^unr *f benefit* of « xmB«fy
'
*» Bofln* to
fMnfliflUy -and -nil mlnf f f; * • =•
""<«
State', opinion of tb> Frefa«»d
' '•,. t
Figure 7-1 Evaluation Criteria
21
-------
Post-cleanup biota monitoring will be required to assess the long-
term effectiveness of capping as a containment action. Annual
monitoring will be conducted for the first ten years after remedial
action completion.
The Total Cost for the alternative will be approximately $1.45
million.
Alternative No. 2b: Cement Capping with Surface Water Diversion
This alternative will be the same as 2a except with the added
protection of a cement cap. Restoration will not be possible on the
cement cap, but a new drainage channel to divert the creek will be
required combined with creation of a new wetland onsite.
The Total Cost for this alternative will be approximately $11.87
million.
Alternative No. 2c: Asphalt Capping with Surface Water Diversion
This alternative will be the same as 2b except with an asphalt cap.
The protection from infiltration will reduce the potential for any
virtual migration of mercury into the groundwater.
The Total Cost for this alternative will be approximately $11.17
million.
Alternative No. 2d: Multi-layer Capping with Surface Water Diversion
This alternative will be the same as 2b except with a multi-layer cap
appropriate for the disposal of solid waste under the Resource
Conservation and Recovery Act (RCRA). This type of cap will consist
of a compacted clay layer, a high density polyethylene layer, a
drainage layer, a gas vent layer, and a soil revegetation layer. A
multi-layer cap will provide additional protection from infiltration
and erosion of rainwater. The protection from infiltration will
reduce the potential for any virtual migration of mercury into the
groundwater, including any downward migration into groundwater.
The Total Cost for this alternative will be approximately $11.17
million.
7 .3 ALTERNATIVE No. 3 - Excavation/Onsite Treatment/Of f site Disposal
This alternative is a source removal action which will involve the
installation of erosion and sediment control and stormwater
management provisions. It will also include the excavation of
mercury-contaminated sediment in the Upper Arm Swamp Zone, onsite
treatment of the soil by stabilization, loading of the treated
material onto trucks, and transportation to an approved disposal
facility. After contaminated materials have been removed, the Site
will be backfilled with clean fill material from an offsite source
and, then, revegetated. The Site layout will require specific areas
for material handling and preparation, storage, treatment, and
loading.
22
-------
TABLE 7-1 Comparison of feasible remedial alternatives in the UPPER ARM SWAMP ZONE '
Aliernmivc
1
2
3
10
U>
4
5
No Action/Natural
Recovery with
Monitoring
Capping
Excavalion/Oniite
Treatment/OrTiite
Diipoul
Excavaiion/Onaile
Treaiment/Oniite
Oitpoitt
In Situ
Stabiliution/
Solidification
1[vn* of Action
Natural
Recovery
Containment
Removal
Oniile
Treatment
|n Situ
Treatment
Implementation"1
Period
NAW
6-9 monihi
9-12 monihi
14 year*
6-9 month*
Performance**
Period
5-30 yeari
4-6 yean
6-10 yeari
6- 10 yean
6- 10 year*
Innovative
Teehnolorv
No
No
No
No
Ye*
Subject to
LDRi
No
No
Ye*
Ye*
No
Requirei Offiile 'Capital Con
Trinioon/Dispoitl (5 x 10*)
No .025
No 0.9-11.7
Ye* 64
No 30.4
No 36.3
Pjeicnl
Wonh
O&M CuJi Toul Con
(S x 10") (S x |0"j
.30
.20
.20
.325
.20 1.45-11.87
.20 64.20
30.60
36.SO
(«) Excluding liim required for design.
(b) Time required to meet RAOi after Implemenutlon of remeditlion.
(c) Th* natural ledimenution procen will be carefully monitored for 5 yetra.
-------
Excavation of contaminated soil will encompass approximately 25 acres
(100,000 yd3). After excavation, soils analyzed and determined to be
at risk will be required to be chemically stabilized onsite prior to
transport to an approved land disposal facility. This offsite
facility will be approved in accordance with applicable EPA, DOT, and
other federal and state regulations.
Post cleanup monitoring will be required to assess the long term
performance of this remedial action. Annual monitoring will be
conducted for 10 years after implementation of remedial actions.
The total cost for this alternative will be between $21.2 million and
$78.2 million.
7 .4 ALTERNATIVE No. 4 - Excavation/Onsite Treatment /Onsite Disposal
This alternative is a source area removal and treatment action and
will necessitate installing erosion and sediment control and
stormwater provisions. The primary components of No. 4 are
excavation of mercury-contaminated sediments in the Upper Arm Swamp
Zone, onsite treatment of the soil by stabilization, onsite disposal
in newly constructed onsite landfill, backfilling with clean soil,
revegetation, and monitoring. The type of landfill will be determined
by the results of a TCLP test. The new landfill construction will
require extensive siting, design, and regulatory review.
After the excavation of approximately 25 acres, the soils will be
analyzed. The chemicals which were determined to be at risk will
require chemical stabilization onsite prior to being placed in the
onsite land disposal facility. This facility will be constructed in
accordance with applicable federal and state regulations.
Post cleanup monitoring will be required to assess long-term
effectiveness of the action. Annual monitoring will be conducted for
10 years after implementation of remedial actions.
The total cost for Alternative 4 will be approximately $30.6 million.
7.5 ALTERNATIVE No. 5 - In-Situ Solidification/Stabilization
Alternative 5 is a source area treatment action. It will entail the
installation of erosion and sediment control and stormwater
management provisions. It will consist of adding mercury complexing
agents directly to contaminated sediment in the Upper Arm Swamp Zone
areas of concern to bind the mercury and decrease its availability to
the biota. Cement and lime will also be added to solidify the
sediments. A total of 25 acres will be treated. This alternative
will effectively destroy the 25 acre wetlands of the Upper Arm Swamp
Zone, but will allow this zone to continue to function as a channel
for stream flow. As a component of this option, mitigation of the
destroyed wetlands through the creation of new wetlands at another
location on the Site will be necessary.
24
-------
This alternative will also provide for an extensive study and
verification effort to demonstrate ecosystem viability under existing
conditions. Annual monitoring will be conducted for ten years after
the execution of remedial actions.
The total cost of this alternative is estimated at $36.5 million.
8.0 DESCRIPTION OF ALTERNATIVES FOR THE TRANSITION ZONE
The alternatives that were developed for the Middle/Lower Swamp
Transition Zone are summarized in Table 8-2 on page 28. These
alternatives are variations of excavation and capping of the
contaminated areas. Alternatives will meet or exceed ARARs and
eliminate exposure of receptors to site-related contamination, thus
effectively reducing the toxicity. All the alternatives for the
Transition Zone can be implemented with any of the alternatives for
the Upper Arm Swamp Zone. Table 8-1 is a comparison of feasible
alternatives for the Transition Zone.
8.1 ALTERNATIVE No. 1 - No Action Alternative
No action will allow for natural sedimentation of the Middle/Lower
Swamp Zone. Sedimentation rates throughout the Middle/Lower Swamp
will be observed for 10 years.
The total cost for this alternative will be estimated at $625,000.
8.2 ALTERNATIVE No. 2 - Excavation with Hauling to Upper Arm
This alternative will involve excavating and hauling contaminated
sediment, clearing and removing selected wooded areas as applicable,
and backfilling and revegetating excavated areas. Of the 25 acre
area, approximately five acres between the power line cuts from Cold
Creek to the edge of the floodplain will require clearing, in
addition to the wooded acres east and west of the power lines.
Excavation of 25 acres to a depth of two feet will result in the
removal of approximately 80,000 yd3 of contaminated sediment.
The contaminated sediment will be moved to the Upper Arm Swamp Zone
and placed for capping. The excavated area will be backfilled with
clean soil and revegetated. To compensate for the loss of wetlands
this areas would be restored to wetland status. Mitigation elsewhere
on site will be required to compensate for temporal loss of wetland
functions and values. The total extent of excavation will be
determined during the Remedial Design phase.
Alternative 2 will cost between $1.47 million and $6.57 million.
8.3 ALTERNATIVE No. 3 - Excavation with Onsite Landfill Disposal
Alternative No. 3 will be similar to No. 2, but it will require the
excavated material be hauled to an onsite landfill.
The cost for alternative 3 will be between $2.37 million and $28.67
million.
25
-------
TABLE 8-1 Comparison of feasible remedial alternatives in the TRANSITION ZONE
f«ifomun<«M
TVB« mf Action
TtAat
Wunh
Stibjwiio Ri^glm Offilli CipiulCoii 0AM Cnit Trail Con
1 No Acllon/Nilural
Recovery/Verifier
lion of ccoiyilem
vllhllilf
2.1 Eiclvilion with
l.h USX Ciepinf 1 A
•utviilon)
l.c Eteivition with
1.4 USZ Cipplni (1 A
ticivition)
3.« Entvitlon with
J.b Omllo Diipoul
(1 A oxcmdoa)
l.c Exuwtloo wto>
(1 A txciviilofl)
4.1 Brandon wMi
4.b OffUu Dbpoul
(1 ft oit»T«llon)
4.« SxuvilloawMi
4.4 OflUlo Niooul
0 A txuvition)
5.b
o.b ia?hitl
o.c Cipplni with
6.4 «oncr«t«
•i 7.t C) Tim* NqtrfnJ to iM*t RAOi iftir Impkmtnutlon of nmtdiitlon.
(t) Tli* Mtanl Mdtmtnuiton ^raeui wfll bo cinAilly nmtUond for S yun.
(d) SubillutkKi itMtmtm If nqulrad by TCLT lwdn|.
-------
8.4 ALTERNATIVE No. 4 - Excavation with Off site Landfill Disposal
This alternative is the same as No. 3 with the difference of the
excavated material being hauled to an offsite landfill. Alternative
4 will cost between $7.67 million and $69.97 million.
8.5 ALTERNATIVE No. 5 - Capping with soil
Alternative No. 5 will emphasize containment of the contaminated
sediment. Sheet piling will be installed in order to isolate the
contaminated sediment. If necessary, any wooded areas will be
cleared and removed. A geotextile filter fabric will then be placed
over the contaminated area followed by a 2-ft cap of soil which will
be revegetated.
The cap will minimize exposure of wetland biota to mercury-
contaminated sediment by containing the mercury. It will be designed
to minimize erosion and control stormwater flow by construction of a
1 percent maximum closure grade. Multiple cells will be constructed
to prevent failure.
This Alternative will cost between $1 million and $11.2 million.
8.6 ALTERNATIVE No. 6 - Asphalt Capping
This alternative emphasizes containment of contaminated sediment by
covering with a clean soil and with an asphalt cap. Asphalt capping
materials which will be placed after regrading and compacting the
area and establishing a proper base. Revegetation will not be
possible on an asphalt cap. A channel cut will be necessary to
maintain surface water flow through the Transition Zone.
This Alternative will cost between $1 million and $11.2 million.
8.7 ALTERNATIVE No. 7 - Multi-laver Capping
Alternative No. 7 will utilize a multi-layer capping approach with
highly impermeable clay as part of a system of layers comprising the
cap. Revegetation will occur on this type of cap, but it will not be
comparable to the destroyed wetland that currently exists. A multi-
layer cap will also necessitate cutting a new channel to maintain
surface water flow through the Transition Zone.
This Alternative will cost between $1 million and $11.2 million.
27
-------
TABLE 8-2
REMEDIAL ACTION ALTERNATIVES
COLD CREEK SWAMP, ALABAMA
MIDDLE/LOWER SWAMP TRANSITION ZONE
Alt
Description
No Action/Natural Recovery/Verification of Ecosystem Viability.
2a
2b
Clear/remove 14 acres of woods, excavate 25 acres (1 ft), haul contaminated sediment to the Upper Arm
for containment and capping, backfill excavation (2 ft), and revegetate.
excavation
. . f
Mto^
" '
2d
Clear and remove 14 acres of woods, excavate 25 acres (2 ft), haul contaminated sediment to the Upper
Arm for containment and capping, backfill excavation (2 ft), and revegetate.
Excavate 7 aer«s (1JS),
disposal.
3b
Clear/remove 14 acres of woods, excavate 25 acres (1 ft), stabilize contaminated sediment if required, haul
contaminated sediment to onsite landfill for disposal, backfill excavation (2 ft), and revegetate.
3c
Excavate 7 aere«/f2 f$, etatdze cofigaj
3d
Clear/remove 14 acres of woods, excavate 25 acres (2 ft), stabilize contaminated sediment if required, haul
contaminated sediment to onsite landfill for disposal, backfill excavation (2 ft), and revegetate.
4*
sa^iforcSsposaCb^fii^^l^^n}/^
4b
Clear/remove 14 acres of woods, excavate 25 acres (1 ft), stabilize contaminated sediment if required, haul
contaminated sediment to offsite landfill for disposal, backfill excavation (2 ft), and revegetate.
4d
Clear/remove 14 acres of woods, excavate 25 acres (2 ft), stabilize contaminated sediment if required, haul
contaminated sediment to offsite landfill for disposal, backfill excavation (2 ft), and revegetate.
5b
Clear and remove 14 acres of woods, contain 25 acres with sheet piling, isolate with geotextile filter fabric,
cap with 2 ft of soil, and revegetate.
6b
Clear/remove 14 acres of woods, contain 25 acres with sheet piling, dewater containment area, isolate with
geotextile filter fabric, cap with 5 ft of soil, 6 in. crushed stone and 4 in. concrete or asphalt
7b
Clear and remove 14 acres of woods, contain 25 acres with sheet piling, dewater containment area, isolate
with geotextile filter fabric, cap with 5 ft of day soil, geomembrane, drainage layer, 2 ft cover soil, and
revegetate.
28
-------
* * * *
The NCP categorizes the nine criteria in Figure 7-1 into three
groups:
Table 9-0 Breakdown of Evaluation Criteria
THRESHOLD CRITERIA
PRIMARY BALANCING
CRITERIA
MODIFYING CRITERIA
-overall protection
of human health and
the environment
-long-term
effectiveness
-state acceptance
-compliance with
ARARs (or invoking a
waiver)
-reduction of
toxicity, mobility,
or volume
-community acceptance
-short-term
effectiveness
-implementability
-cost
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.
9.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES FOR THE UPPER
ARM SWAMP ZONE
EPA evaluated each alternative by the standard criteria shown at the
top of page 21 to determine which will best reduce risks posed by
Cold Creek Swamp. To be considered as a remedy, the alternative must
protect human health and the environment and comply with ARARs.
Table 9-1 is a summary of comparative analysis of alternatives for
the Upper Arm Swamp Zone. Section 121 (d) of CERCLA, as amended by
SARA, states that any remedial action selected for a site must
attain, at a minimum, a degree of cleanup that ensures protection of
human health and the environment. In addition, a level or standard
of control under any federal or state environmental law that meets
legally enforceable ARARs must be attained for any hazardous
substance, contaminant, or pollutant remaining on-site at the
completion of remedial actions.
Potential ARARs for the Site are listed in section 9.2 COMPLIANCE
WITH ARARs.
29
-------
9.1 OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
All of the alternatives will provide adequate protection of human
health since the RI indicated that the Site does not represent a
human health risk based upon the exposure assumption. All of the
alternatives except Alternative No. 1 (No Action/Natural Recovery
With Monitoring) will provide protection to the environment.
Alternative No. 2 (Capping With Surface Water Diversion) will provide
source area containment, but it is questionable whether Alternative
2a (Soil Capping) will protect the groundwater pathway. Alternative
No. 3 (Excavation/Onsite Treatment/Offsite Disposal) and Alternative
No. 4 (Excavation/Onsite Treatment/Onsite Disposal) provide a
short-term reduction in ecological risk. Alternative No. 5 (In Situ
Stabilization /Solidification) will also provide source area
containment.
Results of the RI indicate that the Upper Arm Swamp Zone is a source
area that is contributing to continued uptake of mercury by the
biota. Therefore, alternatives that immobilize, treat, or remove the
source area contamination will provide a more effective remedial
action. Alternative No. 1 is also expected to immobilize the
-contaminant source area in the long-term through natural
sedimentation, but will not do so in the short term. Alternative
Nos. 3 and 4 are source area removal actions. Alternative No. 5 is
an in situ treatment action.
The primary advantages to removal actions over treatment actions are
that the source of contamination is permanently removed and there are
permitted disposal facilities within the state of Alabama.
Significant disadvantages of removal actions are that there is an
initial increase in bioavailable mercury due to the mixing of the
system. This increase will asymptotically decrease after the first
few years. In addition, offsite disposal will probably require
treatment due to mercury concentration in the sediment and may
require RCRA-permitted disposal (subject to results of Toxicity
Characteristic Leaching Procedure, TCLP, testing). Pursuant to SARA,
remedial alternatives should prefer permanent treatment of
contaminants at the Site.
9.2 COMPLIANCE WITH ARARs
The evaluation of the ability of the alternatives to comply with
ARARs includes a review of chemical-specific, action-specific and
location-specific ARARs, some of which, in the case of Cold Creek
Swamp, pertain to wetlands and floodplains. The requirements of
federal and state laws are identified and applied to remedial actions
as ARARs using the approach outlined in the EPA's CERCLA Compliance
with Other Laws Manual (EPA/540/G-89/006, August 1988). Applicable
requirements are those cleanup standards, standards of control, and
other substantive environmental protection requirements, criteria, or
limitations promulgated under federal or state law that specifically
address a hazardous substance, pollutant or contaminant, location, or
other circumstances at a CERCLA site. Relevant and appropriate
requirements are those cleanup standards, standards of control, and
30
-------
other substantive environmental protection requirements, criteria, or
limitations promulgated under federal or state law that are not
directly applicable to a hazardous substance, pollutant or
contaminant, location, or other circumstances at a CERCLA site, but
address problems or situations sufficiently similar to those
encountered at the CERCLA site and whose use is well suited to the
particular site. The judgment of the relevance and appropriateness
of a required action depends on the substances in question or the
physical nature of the site.
Section 121 (d) (4) of CERCLA identifies six situations under which
compliance with ARARs may be waived:
• The remedial action(s) selected is an interim action and is part
of an overall, total remedial action which will attain the ARAR
upon implementation
• Compliance with the ARAR will result in a greater risk to human
health and the environment than alternative options
Compliance with the ARAR is technically impracticable from an
engineering perspective
• An alternative remedial action will attain an equivalent standard
of performance through the use of another method or approach
• The ARAR is a state requirement that the state has not
consistently applied (or demonstrated the intent to apply
consistently) in similar circumstances
• For Section 104 Superfund-financed remedial actions, compliance
with the ARAR will not provide a balance between protecting human
health and the environment and the availability of Superfund
money for response at other facilities.
In order to comply with CERCLA requirements, selected remedial actions
must attain ARARs unless they can claim a waiver under any of the
situations described above. Cleanup levels during the RI/FS process
will generally be based on chemical-specific and location-specific
ARARs or health-based levels.
In the event that an ARAR does not exist, other pertinent guidelines
and standards should be considered. These are commonly referred to as
To-Be-Considered (TBC). Risk-specific doses (RSDs), reference doses
(RFDs), health advisories (HAs), and state and federal guidelines and
criteria, etc., are examples of TBCs.
All alternatives will meet their respective standards except for
Alternatives No. 1 (No Action), No. 2a (Soil Capping), 2b (Cement
Capping) and 2d (Asphalt Capping) . Alternatives 2a, 2b, and 2c do not
meet the RCRA regulations for Solid Waste Management, specifically the
closure regulations under 40 C.F.R. Part 258, Subpart F. These
regulations are relevant and appropriate requirements for the waste
31
-------
TABLE 9-1 Summary of Comparative Analysie of Remedial Alternatives in the UPPER ARM SWAM*
ZONE
Criteria
OVERALL PROTECTIVEHESS
Human Health Protection
- Oral Ingestlon of fish
and/or shellfish caught
recreatlonally within
swamp wattci
- Dermal contact with
potential contaminated
water within the ewamp
during recreational
flihlng
Alternative Ho. 1
Ho Action/Natural
Rtcovary with
Monitoring
Existing condition* Indi-
csted risk
-------
TABLE 9-1 CONT.
Criteria
LONG-TERM EFFECTIVENESS
AND PERMAHEHCE
Magnitude of Reslduel Risk
to Human Health
- Oral Ingestlon of tl*h
and/or shellfish1 caught
reereatlonally within
swamp water*
• Dermal contact with
potential contaminated
water within tha awanp
during racraatlonal
flihlng
Environmental Ftotactlon
Adequacy and Reliability of
Control!
Naad tor Annual Review
AU«rn*llva No. 1 No
Action/Natural
Recovery with
Monitoring
Treatment Procan Used
Exitting condltloni
Indicated risk <1 x 104 for
both carcinogenic and
noncarclnoganlo effects.
No action required.
Existing condition*
indicated riak <1 x 10« for
both carcinogenic and
noncarclnogenlo effect*.
No tctlon required.
Lack;oC short-torn source
• rea' traetatent provide*
continuing source w«i
contribution of mercury.
Natural recovery requires
Long tlae frame.
No control* over regaining
contaalnatlon. Reliability
of remedy unknown until
5-year monitoring prograa
conpleted.
Review and long tern
monitoring would be
required to ensue*
adequate protection to t
human health and tb*
environment 1* provided
through natural recovery.
None
Alternative No. 2
Capping with
Surface Water
Diversion
Alternative No. 3
Excavation, Onilte
Treatment, Offdte
Disposal
Alternative No, <>
Excavation, Ons1 to
Treatment, Onslt*
Disposal
See Alternative No. 1 See Alternative No. i.
See Alternative No. 3.
See Alternative No. 1 See Alternative No. 1.
Source area oapplng
provide* quickest
depuration of oercury
from biota (4*6 yr)
Capping control*
againat generation of
•ethyl mercury and
aubaequent uptake by
biota, thereby
removing oour.ce area.
Monitoring required to
enaure integrity of
remedy. Monitoring of
awamp biota neceaaary
to verify reduction of
mercury body burden*.
Capping.
Excavation of contami-
nated aedlment* provide*
raiuipenilon and
subsequent bloavall*
ability of mercury, and
require* longeit tin*
frame for depuration of
mercury (>* yrs).
Excavation, treatment, and
dliposai removes source
area contamination.
Monitoring of swamp biota
.necessary to verify
reduction of mercury body
burden*,
Stabilisation and offa It*
land disposal,
See Alternative No. 1.
See Alternative No. 3.
See Alternative No. 3
See Altemetlve No. 3.
.ALiornalivu No.
IS Situ
SloblIllation/
Solidification
Soe AlternaUvo No. 1.
S«« ALttrnallve Ho. 1.
Stibllltotlon of
sediments Intermediate
Cor depuration of
mercury (X yrs).
StiblLUotlon controls
against jonocotlon o(
oothyi mercury and
iub§equ«nt uptake by
biota.
S.o AUematlva No. Z.
Stabilisation and on»lto
land disposal.
In Situ ttabllltatlon.
-------
TABLE 9-1 CONT.
Criteria
Alternative Mo. 1
No Action/Natural
Recovery with
Monitoring
Amount Destroyed or Treated None
Reduction of Toxlcity,
Mobility, or Volume
None
A)
tk
Irreversible Treatment
Type and Quantity of
Realduels Remaining After
Treatment
Statutory Preference for
Treatment
SHORT-TERM EFFECTIVENESS
Community Protection
None
None
Does not satisfy.
No risk.
Hork»r Protection
Mo tick to workers.
Alternative No. 2
Capplni with
Surface Hater
Diversion
>?9X of mercury
immobilized in upper
swamp rone.
Reduced tox1city of
oeroury. Mobility of
•cure* ares conttnl-
natlon it Halted 1>y
oapplnt. Voluoe of
source area not
addressed.
Treatment is
reversible as mercury
cannot be destroyed.
ALL o£ mercury remslns
onsite, bound to the
solL.
Does not satisfy.
Temporary Increase in
dust production
through cap Instal-
lation. Contaminated
materials undisturbed.
Denial protection
required durlni cap
installation.
Alternative Mo. 3
Excavation, Onsite
Treatment, Offtlte
Disposal
>99X of oercury con-
tamlnants immobilized and
removed froa the Upper
Swamp lone source ares.
Reduced voluae, toxlclty,
and nobility of source
area contamination since
100,000 yd' material
removed froa site,
treated, and disposed.
Impact to site is
Irreversible since mercury
removed.
»JX of oeroury removed
from upper swamp cone.
Dost not satisfy due to
offilte disposal.
Excavation would release
dust and vapors could
potentially release
hazardous contaminants.
Storafe of excavated
contaminated sediment nay
present hasards.
fotentlal hazards
associated with hertdlint
wastes. Dermel and
respiratory ttl retired
durint excavation and
construction activities.
Alternative No. 4
Excavation, Onsite
Treatment, Onsite
Disposal
See Alternative No. 3.
See Alternative No. 3.
See Alternative No. Z.
See Alternative Ho. 3.
Setlsfles.
See Alternative No. 3.
See Alternative No. 3.
AUernaUvo Ho. S
i2 Situ
Stabilization/
Solidification
>99I of morcury
Immobilized In Upper
Swamp lone.
Reduced toxlclty of
mercury. Mobility Is
limited by chemical
stabilization and
solidification. Volume
la not roducod, •
See Alternative No. 2,
Soo Altornottve Ho. 2.
Satisfies.
Temporary Increase In
dust production during
process could
potentially release
hazardous contaminants.
See Alternative No. 3.
-------
TABLE 9-1 CONT.
Criteria
Environmental Impact*
Tim* Unit Action i*
Complete
U)
Ul
IMPLEHEHTABIim
Ability to Conitruet tnd
Operate
Alternative No. 1
No Action/Natural
Recovery with
Monitoring
Continued Impact from
existing condition* with
txpactad long-term
reduction.
Not yat predictable.
No eonitruction or
oparatlon.
Alternative No. 2
Capping with
Surface Hater
Qlv«r»lon
Destruction of weUanda.
Possible destruction of wooded
swamp bottom-land which la
likely not to reestablish.
Ajsphalt concrete, snd
multimedia caps completely
•change ecological
characteristic* ofUASZ.
Depuration of aeroury
fro* blot* it * lent
tarm prooees
(*-« yrs).
Cap construction would
require 'about 100,000
yd' or eov«t toll.
Capping and creation
of drainage channel la
relatively standard
construction aotivlty,
Aiphili tnJ conerele etpi are
•11 ritk to fall If underlying
lediment cannot ba properly
compacted.
Alternative No. 3
Excavation, Onalta
Traataant, Offalte
Diapoaal
Daatruotlon of watlaAda.
Jxoavation aetlvltlaa
could advataaly affect •
aurroundlni anvlronmant,
will produce vapori and
duat, will raauapand
nercury and maka avail*
abl« to biota. Fill
natarlal muat be
obtainad-»may Inpaet
anvlronjnant alaawhara.
Disturbance to
narevuy-contanlnated
acdimant raaulta in
raauapanaion/incraaaad
bioavallablllty of mercury
and therefore longer
deputation of nercury from
biota («-10 yrs).
Excavation Would require
relatively standard
oonatruotlon aotlvltlea to
excavate soil.
Alternative No. 4
Excavation, On»K«
Treatment, Ontite
Dt«po«*l
See Alternative No. 3.
See Alternative No. 3.
See Alternative Ho. 3,
Conitruotion of Land-
fill alto a atandard
activity.
AUtcntllvu Mo. i
.In SI to
St-ubllUttlon/ .
Solid!ttcatlon
Set AUocnaliv« Ho. 3.
See Alternative Ho. ),
Stabilization if o
relatively itandard
construction activity.
Ease of Doing Mora Action
if Needed
Ability to Monitor
Effectlveneaa
Ability to Obtain Approvala
and Coordinate with Other
Agencies
If monitoring indlcatee
edditlonal action required,
may need to go through the
FS/ROD process sgaln.
Sedimentation activity muat
be carefully monitored.
Mercury tlaaue analyala la
eaally achieved.
No approval required.
See Alternative No. 1. See Alternative Ho. 2,
Viauai inspection and
mercury tissue
analysia are eaally
achieved.
Need to comply with CWA.
Mercury tissue anaiyaia
easily achieved.
Need to comply with CWA
during excavation.
See Alternative Ho. 2.
See Alternative Ho. 3,
See Alternative Ho. 3.
See Alternative No, 2.
See Altematlvo No. 2.
Set Alternative No. 2.
-------
TABLE 9-1 CONT.
Availability of Services
•nd Capacity
Alternative Ho. 1
Ho Action/Natural
Recovery with
Monitoring
No services required.
AvmUbility of Equipment, No equipment or materials
Specialists, and Materials required.
Availability of
Technologies
None required.
COSTS
Capital Colt
Present. Worth OSH Cost
Total Present Worth Cost
0.025
.30
.325
Alternative Ho. I
Capping with
Surface Hater
Diversion
See Alternative Ho. I.
Ho ipteUl acjutpuent
et aitirUli needed
for o«p?lnc. Ctp
aatetitli available
ODlltt.
Cappint taohnolojy
readily available.
0.9-11.7
.20
1.45-11.87
Alternative Ho. 3
Excavation, Onalte
Iseatoent, OtCatte
Dlapoae.1
Heed effiltt disposal
taolllty. Closest
taotllty Is located In
Alabaaa, Capacity U not
an iiiue.
Heed dred(tn(
and opetatoca. Heed
itaillliatlon mateelali.
Uttttbtllty testlnj
Xto/ilced tot itablilta-
tion, Landfill sources
well developed and
available In state of
Alabama,
,20
(4.20
Alternative Ho. <•
Excavation, Onslte
Treatment, Onslte
Disposal
See Alternative Ho. 1.
See Alternative Ho. 3.
Tr»atabiUty ttitins
ee(julred. landfill
construction sources
well developed.
•30.4
.20
30.(0
Alternative No. 5
In Situ
Stabilisation/
Solldltlcetlon
See Alternative No. 1.
Heed specialty equip*
ment for nixing soils In
swamp. Heed
stabilisation materials.
StabllUatlon/Solldlfl-
cation technology
innovative tot mercury.
Treatablllty testing
required to determine If
complexlng agent offers
benefits over existing
ilt-uatlon,
36.3
.20
56,50
-------
sludge in the Upper Arm Swamp Zone. Alternative No. 2 will provide for
the creation of a new wetland in the area where the new drainage
channel will be excavated. This will meet the requirement of the CWA
Section 404 and the Alabama Water Quality Standards. Alternative Nos.
3 and 4 assume restoration of wetlands in the Upper Arm Swamp Zone
subsequent to source area excavation activities. Excavation
alternatives will have to satisfy Clean Water Act requirements during
the excavation operations. Alternative No. 5 will require the creation
of a wetland at some other location. Any mitigation of wetlands will
comply with the requirements of section 404 of the Clean Water Act, the
CWA § 404 (b) (1) guidelines at 40 CFR Part 230, 40 CFR Part 6, Appendix
A, and be consistent with the Memorandum of Agreement between the U.S.
Army Corps of Engineers and the EPA Concerning the Determination of
Mitigation under the 404 (b) (1) Guidelines" (MOA).
The remedial activities may require the discharge of dredged and fill
material. Activities which include the discharge of fill material into
waters of the United States, including most wetlands, are typically
regulated by Clean Water Act Section 404. 33 U.S.C. §§ 1344. In this
case CWA Section 404 is applicable and is therefore designated as an
applicable or relevant and appropriate requirement (ARAR). Although a
CWA § 404 permit is not required under CERCLA, EPA is obligated to
fulfill the substantive requirements of CWA § 404 and the § 404(b)(l)
guidelines which are included in 40 C.F.R. § 230. Although no
discharge in a wetland shall be allowed when there is a practicable
alternative, the necessity to address contamination in the Cold Creek
Swamp leaves no practicable alternative. 40 C.F.R. § 230.10(a).
All appropriate and practicable steps must be taken to minimize
potential adverse impacts of the discharge on the aquatic ecosystem.
40 C.F.R. § 230.10 (d). Subpart H of 40 C.F.R. Part 230 sets forth the
steps which can be taken to minimize the effects of fill activities.
Section 230.75(d) states that habitat development and restoration
techniques may be used to minimize adverse impacts and to compensate
for destroyed habitat. These techniques include wetland restoration,
enhancement, and/or creation.
If fill activities are unavoidable in order to conduct the remedial
actions in Cold Creek Swamp, mitigation shall be required. The
"Memorandum of Agreement between the U.S. Army Corps of Engineers and
the EPA Concerning the Determination of Mitigation Under the 404(b)(I)
Guidelines" (MOA) states that mitigation includes wetland restoration
(the favored alternative), enhancement, and/or creation. The
evaluation of the appropriate level of mitigation is based solely on
the values and functions of the aquatic resource that will be impacted.
According to the MOA, mitigation should provide at a minimum one for
one functional replacement with an adequate margin of Safety to reflect
the expected degree of success associated with the mitigation plan.
The MOA considers as a reasonable surrogate a minimum of one to one
acreage replacement for no net loss of functions and values. However,
the ratio may be greater when the functional values of the area
impacted are demonstrably high and the replacement wetlands are of
lower functional values or the likelihood of success is low.
Conversely, the ratio may be less than one to one when functional
37
-------
values' associated with the impacted area are demonstrably low and the
likelihood of success of the mitigation project is high. Also, the
level of mitigation must also compensate for temporal losses incurred
due to the length of time associated with recovery of injured wetlands
in restoration and the length of time associated with developing
functional values in newly created wetlands.
EPA is also required to mitigate the loss of wetlands under 40 C.F.R.
Part 6, Appendix A, implementing Executive Orders-11988 ("Floodplain
Management') and 11990 ("Protection of Wetlands'). Executive Order
11988 requires federal agencies to reduce the risk of flood loss, to
minimize the impact of floods on human safety, health and welfare, and
to restore and preserve the natural and beneficial values served by
floodplains. Executive Order 11990 mandates that federal agencies
minimize the destruction, loss, or degradation of wetlands, and
preserve and enhance the natural and beneficial values of wetlands.
Appendix A to 40 C.F.R. Part 6 sets forth Agency policy and guidance
for carrying out the provisions of the Executive Orders. The Executive
Orders apply to activities of federal agencies 'providing Federally .
. . assisted construction and improvements . . . and federal activities
and programs affecting land use, including but not limited to water and
related land resources planning, regulating, and licensing activities.'
40 C.F.R. Part 6, Appx. A, Section 5a.
Another potential ARAR is the Corrective Action Management Unit (CAMU)
Rule, 58 Fed. Reg. 8657 (Feb. 16, 1993), which is an ARAR at these
Sites. Designation of a CAMU at these Sites achieves the policy
objectives of EPA in promulgating the CAMU Rule, most notably,
•providing remedial decisionmakers with an added measure of flexibility
in order to expedite and improve remedial decisions" which result in
effective, protective, and cost-effective remedies and to "override any
regulatory disincentive against a given remedy" as the result of
Resource Conservation and Recovery Act (RCRA) Subtitle C requirements.
58 Fed. Reg. 8659-60 (Feb. 16, 1993).
Pursuant to the CAMU Rule, placement of remediation wastes within a
CAMU is not land disposal under Section 3004(k) of RCRA. 42 U.S.C.
§§ 6924(k); 40 C.F.R. § 264.552(a) (1) . Therefore, placement of
remediation wastes within a CAMU does not trigger either the Land
Disposal Requirements (LDRs) or the Minimum Technology Requirements
(MTRs). 40 C.F.R. § 264.552 (a) (1) and (2).
•Remediation wastes, are defined as "all solid and hazardous wastes,
and all media (including ground water, surface water, soils and
sediments) and debris that contain listed hazardous wastes, or which
themselves exhibit a hazardous waste characteristic, that are managed
at a facility ..." 40 C.F.R. § 260.10. The term refers to wastes which
originate from remedial activities at the facility or wastes originally
located at the facility, but which were associated with a release that
migrated beyond the facility boundary. 58 Fed. Reg. 8664 (Feb. 16,
1993) . Any sediments that are excavated which exhibit a hazardous
waste characteristic or contains a listed hazardous waste constitute
"remediation wastes.•
38
-------
Any placement of excavated contaminated sediments within Cold Creek
Swamp does not trigger the LDRs or MTRs because placement of
remediation wastes into a CAMU is not land disposal tinder RCRA Section
3004 (k). 42 U.S.C. § 6924(k). Pursuant to the Regional Administrator's
authority under 40 CFR §264.552 (a), the entirety of Cold Creek Swamp
is designated as a CAMU.
The following is a list of potential ARARs:
• 40 CFR Parts 260-270 Hazardous Waste Management Regulations,
including regulations pertaining to Corrective Action Management
Units effective April 19, 1993.
40 CFR Part 257-258 Solid Waste Management Regulations
• Alabama Hazardous Wastes Management and Regulations Act pertaining
to treatment, storage, and disposal of mercury-contaminated
sediment (subject to results of TCLP testing) .
• Clean Water Act and Alabama Water Quality Standards as they pertain
to ambient water quality for protection of aquatic life.
• National Pollution Discharge Elimination System pertaining to
discharge from any dewatering system to waters of the United
States.
• Clean Air Act, National Ambient Air Quality Standards pertaining to
control of particulate matter emissions.
• Federal Endangered Species Act, Alabama Non-Game Species
Regulation, and Alabama Invertebrate Species Regulation pertaining
to impacts on sensitive species.
• Clean Water Act Section 404, and applicable regulations pertaining
to wetlands destruction and mitigation, including Clean Water Act
404(b)(l) guidelines at 40 CFR Part 230 and 40 CFR Part 6.302 and
Appendix A.
The Fish and Wildlife Coordination Act of 1989.
The Fish And Wildlife Conservation Act of 1980.
Migratory Bird Treaty Act of 1972.
• Rivers and Harbors Act of 1899
The following is a list To Be Considered (TBC) :
• Threshold Limit Values, American Conference of Governmental
Industrial Hygienists, pertaining to emissions of mercury and
mercury compound vapors.
Federal Executive Order 11988 (Floodplain Management), and Federal
Executive Order 11990 (Wetland Protection)
39
-------
State of Alabama proposed Regulations on Municipal Solid Waste
Landfills
• EPA Guidance on Final Covers on Hazardous Waste Landfills and
Surface Impoundments. July 1989
• Memorandum of Agreement between the U.S. Army Corps of Engineers
and the EPA Concerning the Determination of Mitigation Under the
404 (b) (1) Guidelines.
• Long, Edwards R. and Lee, G. Morgan. 1990. The Potential for
Biological Effects of Sediment-Sorbed Contaminants Tested in the
National Status and Trends Program. NOAA Technical Memorandum NOS
OMA No. 52.
9.3 LONG-TERM EFFECTIVENESS
The capping alternative (No. 2), the excavation/disposal alternatives
(Nos. 3 and 4), and the in situ treatment alternative (No. 5) will
provide long-term effectiveness, because these alternatives will use
processes to reduce hazards posed by all known contaminants at the
Site.
Alternative No. 2 (Capping) provides an impermeable barrier to prevent
contact of the contaminated sediments by biota. This barrier should
effectively minimize bioaccumulation of mercury from the source area.
Capping is an effective long-term action provided that regular
inspection and maintenance is conducted. Alternative 2a (Soil Capping)
may not provide a reduction in the mobility of contaminants through the
groundwater pathway.
Alternative Nos. 3 and 4 are excavation/disposal alternatives. These
options require that contaminated material be excavated and removed
from the designated source area. Alternative No. 3 provides for
permanent removal of the contamination from the Site. Alternative No.
4 does not.
Alternative No. 5 uses in situ solidification/stabilization to treat
the contaminated sediments in the source area. This technology,
although effective in remediation of Sites with contaminated soil, is
not proven for long-term effectiveness for mercury-contaminated soil.
Treatability testing will be required.
9.4 REDUCTION OF TOXICITY. MOBILITY. OR VOLUME
Alternative No. 1 (No Action) and 2 (Capping) do not involve treatment
and therefore, cannot be addressed here as reducing the toxicity,
mobility, or volume.
Alternative Nos. 3 and 4 will provide for good long-term reduction of
toxicity and mobility, in addition to providing a reduction of volume,
because these alternatives will provide for removal, treatment, and
offsite disposal of contaminated soils. These alternatives, however,
40
-------
will allow for short-term increase in contaminant mobility and toxicity
for the first year after implementation of the action due to
resuspension/increased bioavailability of mercury.
Alternative No. 5 will provide for good reduction of toxicity and
mobility of contaminants through treatment, but will not provide volume
reduction since materials will be added for
solidification/stabilization.
9 .5 SHORT-TERM EFFECTIVENESS
All alternatives except for No. 2 will not provide short-term
effectiveness. Alternative No. 2 (Capping) is anticipated to have the
greatest short-term effectiveness.
The excavation/disposal alternatives (Nos. 3 and 4) will present the
greatest risk from sediment suspension and transport. Excavation will
release increased amounts of mercury into the system for the short
term; in addition, there are hazards associated with offsite transport
of contaminated sediment. Another short-term risk associated with
Alternative No. 4 will be storage of excavated wastes prior to
treatment.
The in-situ treatment action (Alternative No. 5) will result in the
least short-term environmental impact as sediments are made
bioavailable during the in-situ mixing process. Alternative No. 5
requires significant Site disturbance to implement.
Alternative Nos. 2 and 5 could be implemented within 6-9 months.
Alternative No. 3 could be completed within 9-12 months. Alternative
No. 4 will require at least 1-3 years.
9.6 IMPLEMENTABILITY
Alternative No. 1 (No Action/Natural Recovery) will be the simplest to
implement. This alternative will include long-term monitoring of
sediment, biota, and surface water to assess performance of natural
recovery.
Alternative No. 2 (capping) will be relatively simple to construct and
operate. Alternative No. 2 will include construction of a cap to
eliminate the mercury sediment-water interface where methylation occurs
and to contain source area contamination in-place. This is a common
construction practice. Long-term monitoring and maintenance will be an
essential component of this alternative.
Alternative No. 3 (Excavation/Offsite Disposal) will present
significant difficulties during excavation and handling of contaminated
sediment. Excavation/dredging will present construction-related and
health-related concerns. Transport and of fsite disposal will require
permitting and coordination with the State of Alabama and the
EPA-approved facility and might require consideration of RCRA transport
41
-------
and disposal requirements. Availability and capacity for offsite
disposal is adequate, since the Emelle, Alabama, facility is located
less that 200 miles from the Site.
Alternative No. 4 (Onsite Disposal) will present the most difficulties
in implementation. Excavation and material handling concerns will also
apply to this alternative. Onsite treatment will require construction
of a facility for treating the contaminated sediments. Onsite disposal
will require construction of a landfill on plant property. Storage
provisions for excavated wastes will be required.
In situ Solidification/Stabilization (Alternative No. 5) will be even
more complex than the capping and excavation with offsite disposal
alternatives previously discussed, particularly due to the wetland
environment. Vast amount of material would have to be introduced into
the wetland in order to solidify/stabilize the sediment. Treatability
testing and specialized equipment for mixing wetland sediments will be
required.
9.7 COST
Alternative No. 2 (Capping) is the most cost-efficient of the
alternatives, excluding alternative No. 1 (No action). Examination of
costs indicates that the capital costs for Alternative No. 3
(Excavation/Disposal) are approximately 6 to 71 times more than the
capital costs for Alternative No. 2. Capital costs for Alternative Nos.
4 and 5 (assuming mercury-contaminated sediment to be classified as
non-hazardous under RCRA) are approximately 3 to 40 times more than
those for Alternative No. 2. Operation and maintenance costs for all
alternatives are fairly comparable. A summary of costs for each of the
remedial alternatives is provided in Table 9-1.
10.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES FOR THE
TRANSITION ZONE
EPA evaluated each alternative by the standard criteria shown at the
top of page 21, and further explained in section 9.0 relating to the
Upper Arm Swamp Zone, to determine which will best reduce risks posed
by Cold Creek Swamp. To be considered as a remedy, the alternative
must protect human health and the environment and comply with ARARs.
Table 10-1 is a summary of comparative analysis of alternatives for the
Transition Zone.
10.1 OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
Based on the assumption in the Remedial Investigation that the Site
does not represent a human health risk, all of the alternatives will
provide adequate protection of human health. However, the Feasibility
Study Report indicated that the Middle/Lower Swamp Transition Zone is
a source area that may be contributing to continued uptake of mercury
42
-------
TABLE 10-1 Summary of Comparative Analysis of Remedial Alternatives in the TRANSITION ZONE
Cfiierii
Altcmitive No. I
No Action/Natural
Recov«ry/Verific«tion
of Ecotvttem Vlibilltv
Alternative No. 2
Excavation with
USZ Ceoolnt
Alternative No. 3
Excivttlon ind Onilte
Ditpoul
(with Trettmenfl
Alternative No. 4
Excmtlon ind Offiite
Dlipoiil
(with TreaimenO
Allcrnttiv* Not. 5, 6, inJ 7
Cipping of ihe MLSTZ
Ul
OVERALL PROTECT1VENESS.
Human Health Proleelion
- Ont ingeition of fuh
and/or ahellfuh ought
recreitionilly within
iwimp witen
- Dernul conUcl with
potential contaminated
water within the iwtmp
during recreational
(iihlng
Environmental Protection
COMPLIANCE wn-HAPAp,
Chemicil-Speeific ARARi
Lociiion-SpMiflc ARARi
Exiiting condition* Indl- SM Alunutlve No. I.
cn«driik
logictl recepton. The
iwimp recovers nttunl-
ly over lime. Projected
ecologictl riiki tre
ilretdy lufficlently
reduced with
remedittlon of USZ.
No known chemlctl-
tpecific AAARi.
Would not Imptct
weiltndt or floodpltla
it the lite.
See AltenuUveNo. I.
Would Imptct wetlindi^
it lite.
See AliemtUve No. 1.
See Alwmitlve No. I.
See Aliemttlve No. 2.
See AltiroiUve No. I.
SM AltenuUve No. 2.
See Alterhttive No. I.
See Aliertmlve No. I.
See Alteroitlve No. 2.
See AJtemttive No. 1.
See AltemtUve No. 2.
See Alternative No. I.
See Alternative No. I.
Source area remedixed by immobilizing
mercury In toil.
See Alternative No. 1.
Se« Alternative No. 2.
-------
TABLE 10-1 CONT.
Criteria
Action-Specific ARARs
Other Criterii «nd Guidance
LONO-TERM EFFECTIVENESS
AND PERMANENCE
Magnitude of Reiidual Riik to
Human Health
- Oral injeilion of fnh
and/or ihellfuh caught
recreationally within
awamp wattri
• Dermal contact with
potential contaminated
water within the awamp
during recreational
Cubing
Environmental Protection
Alternative No. I
No Aeilon/Niluril
Recovery/Verification
of Ecoivtum Viability
Exiiling condition*
indicated riik < I x 104
for both carcinogenic;
and noncarcinof enlo
effect*. No action
required.
Exitting condition!
indicated riik 6yre).
AlianuUveNo.'J
Excavation and Oiuito
Ditpo'ul
(with Treatment)
Alternative No. 4
Excavation and Offtite
DitpOMl
(with Treatment
Alternative Not. 5, 6, and 7
Capping of the MLSTZ
Would meet requirement* Would meet requirement*
for oo*ite placement of for offalte placement of
aoil. loil.
See Alternative No. 1.
See Alternative No. 2.
See Alternative No. 2.
See Alternative No. 2.
Sc« Alternative No. I.
See Alternative No. 1
See Alternative No. I.
See Alternative No. 1.
Se« Alternative No. 2.
See Altenutlv* No. 2.
Source are* capping
provide* quicken
depuration of mercury
from biot* (4-6 yr).
-------
TABLE 10-1 CONT.
Crilerii
Adequacy and Reliability of
Comrolt
Alternative No. I
No Action/Niiunl
Recovery/Verification
of Ecosystem Viability
No coniroli ov«r re-
miining contamination.
Reliibiliiy of remedy
unknown until 5-yur
(tudy it complied.
Alternative Ho. 2
Excavation with
USZ Cipolni
Remove* tource uri
conumliuilon.
Alternative No. 3
Excmtlon *nd Ooilte
Olipoul
(with Treatment!
S«« Alternative No. 2.
Alternative No. 4
Excavation *nd Offiito
Dlapoial
(with Treatment)
Sef Aliemilivo No. 2.
Altemitive Nos. 5, 6, ind 7
Capping of the ML5TZ
Capping controli 'gainst generation of methyl
mercury ind lubiequent upuke by bioli,
thereby removing tource tret.
Need for Annuil Review
Treatment Procoit Died.
Amount Deitroyed or Treated
Reduction of Toxicily, Mobility,
or Volume
Irreveriibla Treatment
Type and Quantity of (eiiduali
Redlining After Treatment
Suiuiory Preference for Treatment
Review and long term
monitoring would be
required to ensure
•dequate protection to
the environment It
provided through
natural recovery.
None
None
Reduced over long
lerm.
None
None
Doei not satisfy.
Monllorinj of iwamp biota See AJiematlve No. 2. See Alternative No. 2.
ntcemry to verify reduction
of mercury body burdeni.
Removal tad capping In the
USZ.
Mercury removed from the
ML5TZ tod Immobilized In
the USZ.
Reduced volume, toxlo-lry,
tnd mobility of source tret
conttmiiu-doailnce up to
100,000 yd'material
removed from MLSTZ.
Impact to lite U Irrevenlble
tlnce mercury removed.
Mercury removed from
MLSTZ.
See Alternative No. I.
Orulte landfill dlipottl
(with Stabilization).
Monitoring required 10 ensure integrity of
remedy. Monitoring of iwimp biota neceuiry
to verify reduction of mercury body burdeni.
Offalte landfill dltpoul Capping of the MLSTZ.
(with Stabilization).
Mercury removed from Mercury removed from Mercury immobilized in th« MLSTZ.
the MLSTZ tnd dltpoied the MLSTZ tnd dlipoied
of In tn onilte landfill. of In ao offahe landfill.
Sv Alternative No. 2. See Alternative No. 2.
See AllemtUve No. 2.
See Alternative No. 2.
See Alternative No. 2.
See Alternative No. 2.
Reduced toxiciry of mercury. Mobility of
lource area contamini-tion ii limited by
capping. Volume of tourcc area not addressed.
Treatment ii reversible is mercury is left in
place.
All of mercury remains onsile.
Satlified If Modification See Alternative No. I. See Alternative No. I.
la neceiiary.
-------
TABLE 10-1 CONT.
Criterii
Alternative No. I
No Action/Natural
Rtcovery/Verlfication
of Ecomtem Viability
Alternative No. 2
Excavation with
USZ Cipolnt
Alternative No. 3
Excavation and Omit*
Diipoial
(with Treatment^
Alternative No. 4
. Excavation and OfTiiie
CHipoiil
(with Treatment!
Alternative Not. 5, 6, mil 7
doping of ihe MLSTZ
SHORT-TERM EFFECTIVENESS
Community Protection No risk.
Worker Protection
No risk to worker*.
a\
Environmental Impicii
Continued Imptcl from
existing condition* with
expected long-term
reduction.
Time Unit Action ii Complete
Not yet predlcubU.
Excevetloo would releaie
dutt end vepor* could
potentially reletie hazardous
eontimlunu. Temporery
ilong«of«xeivttcd
conumlniUd ledlment mty
preKnt butrdi.
Poteoild buacdi iitocltted
with hindllnf wtttei.
Dennil end mplretory.PPE
requited during «xc«vtUon
end comtnicilon ectivlilw.
Dwuuctloo of w«tliadi.
PouibU de*irucUon of
wooded iwtmp bottomlind
which Ii likely not to re-
emerje, Exwvttlon
tctlvltlw could tdvenoly
tfltet lurtoundlng «nvlron-
meat, will produce vtpori
end duit, will reiuipend
mercury and puke evelUble
to blou. Fill miterUI muit
be obulaed — nuy Impict
environment elMwhere.
Dliturbenctto
merouy-oonumltuud
ledlmenl retulu In
rMuipenilon/lncretied
blo*viUiblllry of ro««urv
end therefor* longer
depuration of mercury from
btou(6-lOyr»).
See Alleautlve No. 2.
See Altemtlive No. 2.
SM AllcnuUve No. 2.
SM Altemtllve No. 2.
SM Alttmitlve No. 2. Sec Altenutiv* No. 2.
Se« Alternative No. 2.
(S-12yMn)
SM Alternative No. 2.
(6-10 yMn)
Temporary increise in dust production through
cap intlallalion. Coniimintted mtleriils ire
left undisturbed.
Dermal protection required during cap
liutalUtioa.
Destruction of wetlandi. Possible destruction
of wooded iwamp bottom-land which ii likely
not to re-emerge. Asphalt, concrete, and
multimedia capi completely change ecological
characterlttici of MLSTZ.
Depuration of mercury from bion it • long
term proceii (4-6 yrt).
-------
TABLE 10-1 CONT.
Criierii
CMPLEMENTABILITY
Ability to Conitruct ind Operate
Ability to Monitor Effectiveness
Ability to Obuin Approvals ind
Coordinite with Other Agencies
Availability of Services and
Capacity
Availability of Equipment,
Specialists, ind Material)
Availability of Technologic*
COSTS
Capital Coil (\tf)
Preient Worth O&M Coil IOC)
ToUl Preient Worth Coil I0(*)
Alurnstive No. I
No Aeiion/Naluril
Ketovery/Verificslion
uf Ecnivmm Viability
No conitruciion or
operation.
Sedimentation activity
muit be carefully mon-
itored. Mercury tissue
anilyiil li Milly
achieved.
No approval required.
Alternative No. 2
Excavation with
USZ Capping
Excavation would require
relatively standard
conilructton actlvltlai lo
excavate toil.
Mercury tluue irulyili
easily tcbleved,
M«y need to Include special
E&S provliloni during
excavation.
No tervlcei required. SM Alternative No. I.
No equipment or
maicriali required.
None required.
Need dredging equlp-rient
end operator*.
Bxcmiloh and capping
technology readily tvillible.
Alternative No. 3
Excavation and Ontil*
Dlipoial
(with Treatment)
See Alternative No. 2.
Conitructlon of landfill
alio e standard activity.
See Alternative No. 2.
See Alternative No. 2.
See Alternative No, I.
See Alternative No. 2.
(Need stabilization
materiali).
Treatablllry testing
required. Ltodfill
eonslnicdon sources well
developed.
Allemslive No. 4
Excavation and Off«ii«
Oliposal
(with Treatment)
See Alternative No. 2.
See Alternative No. 2.
See Alternative No. 2.
Need ofltto ditpoial
facility. Closest facility
Is located In Alabama.
Capacity Is not an Issue.
See Allemslive No. 2.
(Need stabilization
msterlals).
Tresubtliry testing re-
quired for tlablllzatlon.
Landfill sources well
developed end available
in flat* of Alabama.
Alicmilivo Not. 5, 6, tuj 7
Capping of the MUSTZ
Csp conilruction would require up 10 121,000
yd' of cover toil. Capping ind creiiion of
drainage channel iv relatively vnnJird
construction acliviiy. Alphdl ind concrete
caps are at riik to fail if underlying ledimem
cannot be properly compacted.
Visual Inspection and mercury tissue anslysit
are easily achieved.
See Alternative No. 2.
See Alternative No. I.
Clean fill for capping ulxaimble ol'IVile.
Capping technology readily available.
0.025
0.6
0.625
1J-4.4
0.17
1.47-6.57
2^-21,5
0.17
2.37-28.67
7.549.1
0.17
7.67-<9.97
,0.9-11.0
0.17
1.07-11.17
-------
by the biota. Therefore, all alternatives except for Alternative No.
1 will provide for protection of the environment.
Alternative Nos. 2, 5, 6, and 7 will be actions taken totally within
the confines of Cold Creek Swamp. Alternative Nos. 3 and 4 will be
designed to remove sources of contamination from Cold Creek Swamp.
Alternative No. 1 is also expected to immobilize the contaminant
sourcearea in the long-term through natural sedimentation, but will not
do so in the short term.
Alternative No. 2 (Excavation/Haul to Upper Arm for Capping),
Alternative No. 3 (Excavation/Treatment/Onsite Disposal) and
Alternatives 5, 6, and 7 are all capping alternatives. They will
change the topography of the Middle/Lower Swamp Transition Zone which
will result in a change in hydrology. Each of these alternatives will
have and a definite ecological impact, but to an uncertain degree.
Alternatives 3 and 4 will permanently remove the contamination from
Cold Creek Swamp. Alternative No. 4 (Excavation/Treatment/Offsite
Disposal) will result in an immediate short-term ecological risk.
10.2 COMPLIANCE WITH ARARs
All alternatives will meet their respective ARARs except for
Alternative No. 1 (No action) . Wetland and sediment erosion control
requirements must be considered for Alternatives 2 through 7.
Excavation alternatives (2, 3, 4) will have to satisfy Clean Water Act
requirements during the excavation operations. Mitigation
(restoration) of wetlands will comply with the requirements of Section
404 of the Clean Water Act, the CWA § 404 (b) (1) guidelines at 40 CFR
Part 230, and 40 CFR Part 6, Appendix A, and be consistent with the
•Memorandum of Agreement between the U.S. Army Corps of Engineers and
EPA Concerning the Determination of Mitigation Under the 404 (b) (1)
Guidelines. Any movement of contaminated sediment within the wetland
will comply by the RCRA regulations relating to Corrective Action
Management Units (CAMUs) under Subtitle C.
A list of applicable ARARs may be found in section 9.2 Compliance with
ARARs for the Upper Arm Swamp Zone.
10.3 LONG-TERM EFFECTIVENESS
All alternatives except for No. 1 will provide long-term effectiveness.
Alternative Nos. 2, 3, and 4 are excavation/disposal alternatives.
These options will require that contaminated material be excavated and
removed from the designated source area. They will remove mercury
contaminated sediments and backfill 2 feet of soil to render any
residual contamination non-bioavailable.
Alternative No. 2 will involve disposal in the Upper Arm Swamp Zone and
is conditional upon the selection of capping or the remedial
alternative for the Upper Arm Swamp Zone being a selected remedy. In
48
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Alternative No. 3, waste will be treated and disposed of in a newly
constructed landfill on the Cold Creek/LeMoyne Plant Site. Alternative
No. 3 will provide for source area removal, but not for removal of
contaminants from the Plant Site. In Alternative No. 4, waste is
treated and taken to an EPA-approved offsite disposal facility. This
approach moves contaminated sediment to another location. Alternative
No. 4 will provide for permanent removal of the source of mercury
contamination from the Site provided capacity is available.
Alternative Nos. 5, 6, and 7 will cover contaminated sediment and
provide a barrier to prevent contact of the contaminated sediments by
biota. This barrier should effectively preclude bioaccumulation of
mercury as a result of contact with the source area. Capping will be
an effective long-term action provided that regular inspection and
maintenance are conducted.
10.4 REDUCTION OF TOXICITY. MOBILITY. OR VOLUME BY CONTAINMENT
Alternative No. 1, 2, 5, 6, and 7 do not involve treatment, and
therefore, cannot be addressed here as reducing toxicity, mobility, or
"volume.
Alternative Nos. 3 and 4 will provide for long-term reduction of
toxicity and mobility. These alternatives, however, will allow for
short-term increase in contaminant mobility and toxicity after
implementation of the action due to resuspension/increased
bioavailability of mercury.
10.5 SHORT-TERM EFFECTIVENESS
Alternative No. 1 (No Action) will have little or no effect on the
surrounding environment in the short-term.
The excavation alternatives (Nos. 2, 3, and 4) will present significant
environmental risk from sediment suspension and transport. There are
also hazards associated with offsite transport of contaminated
sediment. Another short-term risk associated with Alternative Nos. 3
and 4 will be storage of excavated wastes prior to treatment.
Alternative Nos. 5, 6, and 7 will be anticipated to have the greatest
short-term effectiveness. These alternatives will present the least
amount of risk to workers, the community, and the environment.
Alternative No. 5 could be implemented within 6-9 months. Alternative
No. 2 could be completed in 9-12 months and will be implemented
simultaneously with capping of the Upper Arm Swamp Zone if this remedy
were selected. Alternative No. 4 could also be implemented in 9-12
months. Alternative No. 3 could take several years to implement
because of the technical issues associated with the siting and
specification process. Alternatives 6 and 7 will also take several
years to implement because of the need to allow for sediment
49
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dewate'ring. This could be a problem due to the high rainfall in the
local area.
10.6 IMPLEMENTABILITY
Alternative No. 1 will be the simplest to implement. This alternative
will include a 5 year monitoring of sediment and mercury body burdens
in fish. It will also include an analysis of the Cold Creek Swamp
system viability by way of comparison to a similar non-contaminated
wetland system(s) .
Alternative No. 2 will be relatively simple to implement. However, it
is linked with the capping of the Upper Arm Swamp Zone if this approach
is selected. Excavation/dredging will present construction-related and
health-related concerns. If contaminated sediment is hauled from the
Transition Zone to the Upper Arm Swamp Zone, it will not trigger the
RCRA Land Disposal or Minimum Technology Regulation because it will be
movement of remediation wastes within a Corrective Action Management
Unit (CAMU) . The CAMU is the entirety of Cold Creek Swamp (Figure 2-
1) .
Alternative No. 3 will present difficulties in implementation.
Transport and offsite disposal will require coordination with the State
of Alabama and the EPA-approved facility and might require
consideration of RCRA transport and disposal requirements, and subject
to results of TCLP testing. Onsite treatment, if necessary, will
require construction of a facility for treating the contaminated
sediments. Onsite disposal will require construction of a landfill on
Cold Creek/LeMoyne plant property. Provisions for storage of excavated
wastes will be required.
Alternative No. 4 will present some concern with transporting
contaminated sediment across the Plant Site and to the disposal
facility. Excavation and dredging concerns will be the same as
Alternative No. 2 above.
Alternative No. 5 will also be relatively simple to construct and
operate. Alternative No. 5 will include construction of a cap to
eliminate the mercury sediment-water interface where methylation occurs
and to contain source area contamination in-place. This activity is
not a difficult construction practice and will not require specialized
expertise. Long-term monitoring and maintenance will be essential.
Alternatives 6 and 7 will present significant construction difficulties
due to the need to establish a base for cap construction. Dewatering
effectiveness might be a problem. This could ultimately lead to a cap
which quickly fails due to cracking. These alternatives will also
require evaluation of impact to the powerline support structures.
50
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10.7 COST
Alternative No. 1 will be the least expensive. For cleaning up the 7
acres under the powerline cuts, the costs of Alternative Nos. 2 and 5
will be comparable. Costs associated with remediating 25 acres are all
comparable.
Alternative Nos. 6 and 7 will be far more complicated capping
approaches than just using a natural soil cap (Alternative No. 5) and
will be three times more expensive than Alternative 5. The most
expensive will be Alternative Nos. 3 and 4 if treatment were required
prior to disposal.
11.0 STATE ACCEPTANCE
EPA has consulted with the Alabama Department of Environmental
Management and received a letter dated September 1, 1993 indicating
State concurrence on the Record of Decision (ROD) , which will document
EPA's remedy selection. See Appendix B.
12.0 COMMUNITY ACCEPTANCE
EPA will determine community acceptance of the preferred alternative
after considering comments received during the public comment process
associated with the Proposed Plan. EPA will include a Responsiveness
Summary as an attachment to the ROD in Appendix A explaining how it
addressed those comments.
13.0 SUMMARY OF SELECTED REMEDY
The objectives of the selected remedy are to reduce concentration of
hazardous substances, pollutants, and contaminants in sediment in Cold
Creek Swamp; prevent or mitigate the continued release of hazardous
substances, pollutants, and contaminants to all exposure pathways,
including groundwater, surface water bodies, and sediments of Cold
Creek Swamp and the Mobile River; eliminate or reduce the risk to
ecological receptors due to exposure to hazardous substances,
pollutants, and contaminants in Cold Creek Swamp.
EPA's selected cleanup alternative for the contamination and associated
risks in Cold Creek Swamp is based upon a number of factors including
mercury levels in sediment, mercury levels in biota, recommended levels
of safety as found in the literature, the information contained in the
ecological risk assessment, and the risk to the ecosystem presented by
the selected remedy. For the Upper Arm Swamp Zone (Figure 2-1} of Cold
Creek at the Stauffer Chemical Superfund Sites, the selected remedy is
No. 2d, Multi-layer Capping and Containment of the Upper Arm with a
Surface Water Diversion including Long-Term Monitoring of the entire
51
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wetland. This alternative will include burial of the mercury-
contaminated soils in place. The multi-layer cap will add additional
protection from infiltration and prevention of migration to
groundwater. The selected alternative will include creation of a new
channel to divert surface water flow and by-pass the capped Upper Arm
Swamp Zone along with creation of a new wetland in the new channel.
The determination of the appropriate level of mitigation will be based
upon functional equivalency of wetland values lost taking into
consideration the likelihood of success in creating new wetlands and
consistency with the MOA. The remedy also includes long-term
monitoring of the wetland to determine if making contaminants immobile
will provide necessary protection of people and the environment. The
criteria for this determination will be 0.5 ppm of mercury in whole
body fish (bottom feeders, carnivores, omnivores) and 1.1 ppm of
mercury in muscle, kidney, and brain tissue of upper trophic levels of
mammals. Also an evaluation of the toxicity to biota in Cold Creek
Swamp will be required. This will provide the best balance of the
evaluation criteria. The total estimated cost is $11,170,000. EPA
believes this remedy will be fully protective, will meet standards, and
will use permanent solutions.
EPA's selected alternative for the Middle/Lower Swamp Transition Zone
of Cold Creek is Alternative 2d which is the excavation of the
Transition Zone and hauling it to the Upper Arm Swamp Zone for capping;
the total extent of excavation will be determined during the Remedial
Design. This will also include restoration of the Transition Zone and
continued monitoring of the entire wetland. Mitigation onsite will be
required to compensate for temporal loss of wetlands. The
determination of the appropriate level of mitigation will be based upon
functional equivalency of wetland values lost taking into consideration
the likelihood of success in creating new wetlands and consistency with
the MOA. The total estimated cost will be $ 6,570,000. The total cost
of remediation of the Upper Arm Swamp Zone and the Transition Zone is
$17,740,000.
The monitoring for the remedy implementation shall include, but not be
limited to, pre-activity sampling, sampling during remedial
implementation, and post remedial sampling including ultra-detection
limits for mercury in water and methyl mercury determination in
sediments. It should also include, but not be limited to sediment
chemistry, toxicity testing, and bioaccumulation measurements. If any
of this monitoring shows unacceptable levels as set out in this ROD,
additional remediation may be required. Monitoring will also include
periodic analysis of the success of any mitigation efforts. If
mitigation efforts are unsuccessful as set forth in this ROD,
additional mitigation shall be required.
In addition, EPA will require institutional controls which include a
building up of the levees between Cold Creek Swamp and the Mobile River
so as to limit exchange of contaminants from Cold Creek Swamp to the
Mobile River. These levees will also be vegetated. This is the
addition of clean fill sediment to the current levees. These levees
will be designed to minimize any alteration of hydrology, to maintain
historic seasonal water levels, and to maintain present hydroperiod in
52
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Cold Creek Swamp. Mitigation will be required to compensate for any
direct or indirect wetland losses due to the impacts of the levees.
Again, the determination of the level of mitigation will be based upon
functional equivalency considering the likelihood of success and
consistent with the MOA. Posting of "No Fishing' and "No Hunting" signs
and strict security to prevent trespassing into Cold Creek Swamp will
also be included.
EPA feels this proposed remedy will reduce high levels of mercury
concentration in sediment and reduce risk of mercury contamination in
all exposure pathways for ecological receptors in Cold Creek Swamp.
Mitigation requirements set out in this ROD do not comprise mitigation
requirements as compensation for damages to natural resource trusts.
14.0 STATUTORY DETERMINATION
Under its legal authority, EPA's primary responsibility at Superfund
Sites is to undertake remedial actions that achieve adequate protection
of human health and the environment. In addition, Section 121 of
CERCLA establishes several other statutory requirements and
preferences. These specify that, when complete, the selected remedy
also must be cost effective and utilize permanent solutions and
alternative treatment technologies or resource recovery technologies to
the maximum extent practicable. Finally, the statute includes a
preference for remedies that employ treatment that permanently and
significantly reduce the volume, toxicity, or mobility of hazardous
substances as their principal element. The following sections discuss
how the selected remedy meets these statutory requirements.
14.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
The selected remedy protects human health and the environment,
particularly the ecological environment of Cold Creek Swamp, through
isolating and removing the principal contaminated sediments of the
wetland and long-term monitoring. The protection of human health and
the environment is provided by consolidation and containment of
contaminated sediment in the Upper Arm Swamp Zone and removal of
contaminated sediment in the Transition Zone and containment of any
residual contamination within Cold Creek Swamp. In so doing the risk
is reduced for uptake of contaminants into biota which in turn reduces
any risk to humans ingesting contaminated biota. It also reduces risk
to groundwater by containment with a multi-layer cap. In addition, the
risk is also controlled through institutional controls and long-term
monitoring.
14.2 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 Cold Creek Swamp were evaluated on the basis of the
53
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degree to which they complied with these requirements. The selected
remedy was found to meet or exceed all ARARs listed below:
TABLE 11-1
FEDERAL ARARs FOR COLD CREEK SWAMP
CLEAN WATER ACT • 33 U. S. C. §§ 1251-1376
Section 404 including
the CWA § 404 (b) (1) guidelines
at 40 C.F.R Part 230,
40 C.F.R Part 6 and Appendix A
Prohbtts discharge of fill material to wetlands without a
permit. Requires that action be taken to avoid and
minimize adverse effects in wetlands and prohforts
discharge to wetlands.
40 C.F.R. Part 6.302 and Appendix A
Requirement to avoid, to the extent possfcte, the
adverse impacts associated with the destruction or loss
of wetlands and to avoid the support of new
construction in wetlands if a practical alternative exists.
R& A
40 C.F.R Part 122, 125
National Pollutant Discharge Elimination
System
Requires permits for the discharge of pollutants for any
point source into waters of the United States. Requires
avoiding adverse impacts or minimize them if no
practicable alternative exists.
R&A
40 C.F.R Part 131
Ambient Water Quality Criteria Requirements
Provides for the establishment of water quality based on
toxicrty to aquatic organisms and human health.
RESOURCE CONSERVATION AND RECOVERY ACT - 42 U.S.C. §§ 6901-6987
R&A
40 C.F.R. Part 258
Criteria for Municipal Solid Waste Landfills
Establishes minimum national criteria for municipal solid
waste landfills under RCRA and municipal solid waste
landfills used to dispose of sewage sludge under the
CWA.
40 C.F.R Part 261
Identification and Listing of Hazardous
Wastes
Identifies those sold wastes which are subject to
regulation as hazardous wastes. Defines the term 'solid
waste* and "hazardous waste."
R&A
40 C.F.R Part 262
Standards Applicable to Generators of
Hazardous Waste
EstabGshes standards for generators of hazardous
wastes.
R&A
40 C.F.R Part 264
Standards for Owners and Operators of
Hazardous Waste Treatment, Storage and
Disposal (TSD) Facilities
Establishes minimum national standards which define
the acceptable management of hazardous wastes for
owners and operators of fadGties which treat store or
dispose of hazardous wastes.
54
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TABLE 11-1
FEDERAL ARARs FOR COLD CREEK SWAMP
Federal Register/VoL 58, No. 29
February 16,1993
40 CFR Part 260 et al.
Corrective Action Managment Units and
Temporary Units; Corrective Action
Provisions; Final Rule
Finalizes provisions for corrective action management
units (CAM Us) and temporary units under Subpart S of
40 C.F.R. Part 264. Defines the term -remediation
waste."
R&A
40 C.F.R. Part 268
Land Disposal Restrictions
Identifies hazardous wastes that are restricted from land
disposal and describes those circumstances under
which an otherwise prohbtted waste may be land
disposed.
CLEAN AIR ACT - 42 U.S.C. §§ 7401-7642
40 C.F.R. Part 50
National Primary and Secondary Ambient Air
Quality Standards
Establishes standards for ambient air quality to protect
public health and welfare.
OTHER FEDERAL ARARs
Federal Endangered Species Act
16 U.S.C. §§ 1531 - 1543
50 C.F.R. Parts 17 and 402
40 C.F.R. § 6302(h)
Requires that Federal agencies insure that any action
authorized, funded, or carried out by the agency is not
likely to jeopardize the continued existence of any
threatened/endangered species, or destroy or adversely
modify critical habitats.
Critical habitats are the specific areas within the
geographic area occupied by the threatened
/endangered species on which are found the features
essential to the conservation of the species.
H a listed species is present, a Biological Assessment is
required to examine any possible Impacts upon the
species or habitat
55
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JC
TABLE 11-1
FEDERAL ARARs FOR COLD CREEK SWAMP
Fish and Wildlife Coordination Act
16 U.S.C. §§ 661-666
40 C.F.R. Parts 6302(g) and § 2903
Requires consultation when a Federal department or
agency proposes or authorizes any modification to
streams or other water bodies (including wetlands) to
provide adequate protection of fish and wildlife
resources and to take action to prevent toss or damage
to these resources.
Actions include discharge of pollutants or dredge and fin
material into a water body or wetland.
Requires states to identify significant, sensitive, or
unique habitats and develop conservative plans for
these areas.
Migratory Bird Treaty Act of 1972
Protects almost all native birds in the U.S. from
unregulated and unintentional "take," which includes
poisoning from hazardous waste.
Rivers and Harbors Act of 1899
33 U.S.C. § 403 and
Section 10 Permits
33 C.F.R. Parts 320-330
Requires permit for structures or work in or affecting
navigable water. Requires consultation with the U.S.
Army Corps of Engineers regarding dredging in
navigable waters below the mean high water line.
A APPUCABLE REQUIREMENTS WHICH WERE PROMULGATED UNDER FEDERAL LAW TO SPECIFICALLY ADDRESS
A HAZARDOUS SUBSTANCE, POLLUTANT. CONTAMINANT, REMEDIAL ACTION LOCATION OR OTHER
CIRCUMSTANCE AT THE COLD CREEK SWAMP SITE.
R&A — RELEVANT AND APPROPRIATE REQUIREMENTS WHICH WHILE THEY ARE NOT •APPLICABLE* TO A HAZARDOUS
SUBSTANCE, POLLUTANT, CONTAMINANT, REMEDIAL ACTION. LOCATION, OR OTHER CIRCUMSTANCE AT THE
COLD CREEK SWAMP SITE, ADDRESS PROBLEMS OR SITUATIONS SUFFICIENTLY SIMILAR TO THOSE
ENCOUNTERED AT THE COLD CREEK SWAMP SITE THAT THEIR USE IS WELL SUITED TO THE SITE.
56
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TABLE 11-2
STATE ARARs FOR COLD CREEK SWAMP
ALABAMA HAZARDOUS WASTE MANAGEMENT AND MINIMIZATION ACT
CODE OF ALABAMA §§ 22-30-1 et sea.
Alabama Administrative Code
Chapter 334-14-2
Identification and Listing of Hazardous
Waste.
Identifies those solid wastes which are subject to
regulation as hazardous wastes. Defines the term "solid
waste' and 'hazardous waste."
R&A
Alabama Administrative Code
Chapter 334-14-3
Standards Applicable to Generators of
Hazardous Waste and/or other Wastes
Establishes standards for generators of hazardous
wastes.
R&A
Alabama Administrative Code
Chapter 335-14-5
Standards for Owners and Operators of
Hazardous Waste Treatment, Storage, and
Disposal Facilities
Establishes minimum national standards which define
the acceptable management of hazardous wastes for
owners and operators of facilities which treat, store or
dispose of hazardous wastes.
R&A
Alabama Administrative Code
Chapter 335-14-9
Land Disposal Restrictions
Identifies hazardous wastes that are restricted from land
disposal and descrfees those circumstances under which
an otherwise prohbited waste may be land disposed.
OTHER STATE ARARS
R&A
Alabama Water Pollution Control Act
Code of Alabama Title 22, Chapter 22
Alabama Water Quality Standards
Alabama Administrative Code,
Chapter 335-6-10; 335-6-.07 (2) (g) and
Table l, p. 10-15
State surface water quality standards for the protection
of human health and aquatic He.
Alabama Non-Game Species Regulations
Alabama Administrative Code § 220-2-.92
Protects non-game species in the state of Alabama.
Alabama Invertebrate Species Regulations
Alabama Administrative Code § 220-2-.98
Protects invertibrate species in the state of Alabama
A APPLICABLE REQUIREMENTS WHICH WERE PROMULGATED UNDER FEDERAL LAW TO SPECIFICALLY ADDRESS A
HAZARDOUS SUBSTANCE, POLLUTANT, CONTAMINANT, REMEDIAL ACTION LOCATION OR OTHER CIRCUMSTANCE AT
THE COLD CREEK SWAMP SITE.
R&A— RELEVANT AND APPROPRIATE REQUIREMENTS WHICH WHILE THEY ARE NOT •APPLICABLE* TO A HAZARDOUS
SUBSTANCE, POLLUTANT, CONTAMINANT, REMEDIAL ACTION, LOCATION, OR OTHER CIRCUMSTANCE AT THE COLD
CREEK SWAMP SITE, ADDRESS PROBLEMS OR SITUATIONS SUFFICIENTLY SIMILAR TO THOSE ENCOUNTERED AT THE
COLD CREEK SWAMP SHE THAT THEIR USE IS WELL SUITED TO THE SITE
57
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TABLE 11-3
TO-BE-CONSIDERED (TBCs) DOCUMENTS FOR COLD CREEK SWAMP
DOCUMENT TYPE
DESCRIPTION
"Memorandum Between the U.S. Army Corps of
Engineers and EPA Concerning the
Determination of Mitigation Under the C.W.A
§ 404 (b) (1) Guidelines
Articulates EPA and U.S. Army Corps of Engineers
policy and procedures to be used in the
determination of the type and level of mitigation
necessary to demonstrate compliance with the CWA
Section 404 (b) (1) Guidelines.
Federal Executive Order 11990 on Protection of
Wetlands
Requires Federal agencies to avoid the adverse
impacts associated with the destruction or toss of
wetlands; to avoid new construction in wetlands if
alternatives exist; and to develop mitigation measures
if adverse impacts are unavoidable.
Federal Executive Order 11988 on Protection of
Floodplains
Requires Federal agencies to evaluate the potential
effects of actions they may take in a floodplain to
avoid the adverse impacts associated with direct and
indirect development of a ftoodplain.
EPA Guidance on Final Covers on Hazardous
Waste Landfills and Surface Impoundments.
_ July 1989
Provides design guidance on final cover systems for
hazardous waste landfills and surface impoundments
Alabama Solid Waste Disposal Act of 1969, as
amended. Code of Alabama 1975,
§ 22-27-1, § 22-22A-5, § 22-22A-8 el sea
Alabama Proposed Regulations on Municipal
Solid Waste Landfills
Chapter 335-13-4
Permit Requirements
Proposes standards for Solid Waste Disposal
FacBfties.
TBCs
TO-BE-CONSIDERED CRITERIA ARE NON-PROMULGATED ADVISORIES AND GUIDANCE THAT ARE
NOT LEGALLY BINDING, BUT SHOULD BE CONSIDERED IN DETERMINING THE NECESSARY LEVEL
OF CLEANUP FOR PROTECTION OF HEALTH OR THE ENVIRONMENT.
58
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14.3 COST EFFECTIVENESS
EPA believes that the selected remedy will reduce the risk to human
health and the environment from the contaminated sediment at a cost
of $17,740,000. The selected remedy 2d for the Upper Arm Swamp
Zone, though slightly more expensive than the similar 2a, provides
a higher level of long term protectiveness by capping the
contaminated sediment with a compacted clay layer, a high density
polyethylene layer, a drainage layer, a gas venting layer, and a
soil revegetatipn layer. This cap provides additional protection
from infiltration and erosion of rainwater and migration to
groundwater. The remedy is much less expensive than the other
alternatives for the Upper Arm Swamp Zone.
The selected remedy for the Transition Zone of 2d, though slightly
more expensive than the capping alternatives, allows for permanent
removal of the contaminated sediment and restoration back to a
wetland status. This will decrease migration of contaminants to
the Mobile River during flooding and increase the functional value
of the Transition Zone. The cost of excavation in this area will
vary depending on the amount of material that will ultimately be
removed, since only a portion of the 25 acre area will be removed,
the total cost is expected to be less than proposed. The cost of
this alternative is within the medium range for cost alternatives
in the Transition Zone.
14.4 UTILIZATION OF PERMANENT SOLUTIONS TO THE MAXIMUM EXTENT
PRACTICABLE
EPA believes the selected remedy is the most appropriate cleanup
solution for Cold Creek Swamp and provides the best balance among
the evaluation criteria for the remedial alternatives evaluated.
This remedy provides effective protection over the long-term life
of the wetland for potential human and environmental receptors, is
implementable, and is cost effective.
14.5 PREFERENCE FOR TREATMENT AS A PRINCIPLE ELEMT?NT
The statutory preference for treatment will not be met because
treatment of the contaminated sediment will assist in not
accomplishing the goals of reducing bioavailable mercury in Cold
Creek Swamp. The mercury in the sediments is in the fairly stable
form of mercury sulfide and is not expected to fail the toxicity
characteristic leaching test. Any further treatment before burial
will not significantly alter the stability of the mercury in the
sediment. The act of capping the sediment will in itself limit the
bioavailability of mercury. Because treatment of the principal
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threats of the site was not found to be practicable, it was not
required in this decision.
15.0 DOCUMENTATION OF SIGNIFICANT CHANGES
The Proposed Plan was released for public comment in July 1993. It
identified alternative 2d for the Transition Zone which included
excavation of 25 acres to a depth of 2 feet. During the public
comment period, commentors expressed concerns regarding excavation
of all 25 acres of the Transition Zone since some areas did not
show extensive sediment contamination. To address these concerns,
the remedy was refined to include sampling during Remedial Design
to better define the areas containing sediment contamination. Only
specific areas containing contaminated sediment will be excavated
so as to reduce the disturbance to the environment.
Also the requirement to analyze liver tissue of upper trophic level
mammals was removed since investigation pursuant to a comment on
the proposed plan determined that liver tissue was not appropriate.
The 1.1 ppm mercury standard in kidney, brain, and muscle remains.
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OU3 Alternatives No. 2d
APPENDIX A;
RESPONSIVENESS SUMMARY
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Leigh Pegues. Director
1751 Cong. W.L
Dickinson Drive
Montgomery. AL
36130-1463
(205)271-7700
FAX 271-7950
270-5612
FieM Offices:
110 VukanRoad
Birmingham. AL
35209-4702
(205)942-6168
FAX 941-1603
P.O. Box 953
Decatur, AL
35602-0953
(205)353-1713
FAX 340-9359
22
rimeter Road
36615-1131
(205)450-3400
FAX 479-2593
«T
'•T.-
Jim Folsom
Governor
bt£/'-:
ALABAMA
DEPARTMENT OF ENVIRONMENTAL MANAGEMENT
September 1, 1993
Ms. Joanne Benante
Remedial Project Manager
South Superfund Branch
U.S. Environmental Protection Agency
345 Courtland Street, NE
Atlanta, Georgia 30365
RE: Stauffer Cold Creek Swamp
Draft Record of Decision
Reference No. 306
Dear Ms. Benante:
ADEM has reviewed the referenced Draft Record of Decision. Based on our
review, we concur with the Draft Record of Decision without further
comments.
If there are questions regarding this matter, please contact Mr. C.H. Cox
of Special Projects at (205) 260-2785.
Sincere/ly,
d ^ 1-2 ]^~^
\ Pegues /[
tor //
IS
LP/CHC/SPS
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OU3 Alternative No. 2d
APPENDIX C;
STATEMENT OF FINDINGS
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STATEMENT OF FINDINGS
STAUFFER CHEMICAL COMPANY-LEMOYNE PLANT
STAUFFER CHEMICAL-COLD CREEK PLANT
COLD CREEK SWAMP (OU3)
MOBILE COUNTY, ALABAMA
This document has been prepared to fulfill the substantive
requirements of the Floodplain Management Executive Order
(E.O. 11988), and the Protection of Wetlands Executive Order
(E.O. 11990), and Appendix A of 40 C.F.R. Part 6, -entitled
Statement of Procedures on Floodplain Management and Wetland
Protection.
(i) The reason why the proposed action must be located in or
affect the floodplain or wetland is as follows.
This Record of Decision addresses Cold Creek Swamp (OU3). The
wetland received contaminated wastewaters from the former
operations at the manufacturing facilities. A June 1992
Supplemental Remedial Investigation Report documents the details of
the study of contamination in the wetland. A November 1992
Supplemental Feasibility Study Report and the March 1993
Supplemental Feasibility Study Report Addendum submitted by Akzo
Chemicals Inc./Zeneca Inc., documents the development, screening,
and detailed evaluation of potential alternatives and risk posed by
the contaminants as they relate to the Site. Furthermore, EPA has
issued a December 10, 1992, caveat to the RI Report and a June 3,
1993, caveat to the FS Report.
Based upon the levels of mercury found in the biota of Cold Creek
Swamp, it is found that bioaccumulation of mercury is occurring and
that mercury is available to the Cold Creek Swamp ecosystem.
Mercury concentration values in Cold Creek Swamp far exceed those
sediment concentrations of mercury which would be expected to cause
ecological effects. Furthermore, the mercury levels in fish
exceeded recommended screening levels to be protective of avian
(0.1 parts per million, ppm) and mammalian (1.1 ppm) species-which
consume them. Actual or threatened releases of hazardous
substances from this site, if not addressed by implementing the
response action selected in this ROD, may present an imminent and
substantial endangerment to public health, welfare, or, the
environment.
(ii) A description of significant facts considered in making the
decision to locate in or affect the floodplain or wetland
including alternative sites and actions is as follows.
The Feasibility Study Report showed that two areas of the wetland
are of particular concern. These areas not only have high levels
of. mercury in sediment but the risk assessment shows a potential
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risk to biota in the wetland. These areas are the Upper Arm (Upper
Arm Swamp Zone) and the Middle/Lower Swamp Zone (Transition Zone) .
The Upper Arm Swamp Zone is the original point of discharge .and
remains the most highly concentrated source area for contamination
driven risks to receptors. The Transition Zone is a sediment
depositional area that receives mercury contaminated sediment from
the Upper Arm Swamp Zone (Figure 2-1) . The mercury will remain in
sediments of the wetland until it either converts to methyl mercury
and accumulates in biota, releases to overlying surface water, or
is physically transported out of the wetland.
The Baseline Ecological Risk Evaluation predicted mercury
concentrations in organisms throughout the wetland after the
sediments in the Upper Arm Swamp Zone and Transition Zone were
isolated or removed. The concentrations of mercury in fish,
turtles, snakes, alligators, and birds were predicted to fall below
levels of concern if contaminated sediment in these two areas were
isolated or removed. Therefore, remediation of these two areas is
predicted to reduce the exposure of biota to mercury contaminated
sediment, and result in reductions in mercury levels in the tissues
of resident biota.
In addition there is evidence that an interconnection exists
between Cold Creek Swamp and the Mobile River. Discharge from Cold
Creek Swamp occurs as the river stages recede and the water ponding
behind the levee seeps out through the levee and flows through the
outfall channels from the wetland to the Mobile River. In addition
Cold Creek flows from the upland area west of the site through Cold
Creek Swamp and into the Mobile River. The nature of the riverine
system is that sediment and surface water from the river is
transported downstream.
(ill)A statement indicating whether the proposed action conforms to
applicable State or local floodplain/wetland protection
standards is as follows.
Remedial actions performed under CERCLA must comply with all
applicable or relevant and appropriate requirements (ARARs) . All
alternatives considered for Cold Creek Swamp were evaluated on the
basis of the degree to which they complied with these requirements.
The selected remedy was found to meet or exceed all
floodplain/wetland protection ARARs and TBCs listed below:
Clean Water Act: Section 404 including the CWA 404 (b)(1)
guideline at 40 CFR 230, 40 CFR 6 and Appendix A,
National Pollution Discharge Elimination System.
• Federal Endangered Species Act (50 CFR Part 402) .
• Fish and Wildlife Coordination Act of 1989.
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Fish and Wildlife Conservation Act of 1980.
Migratory Bird Treaty Act of 1972.
River and Harbors Act.
State of Alabama: Alabama Water Quality Standards,
Alabama Non-Game Species Regulations, Alabama
Invertebrate Species Regulations.
Threshold Limit Values, American Conference. of
Governmental Industrial Hygienists.
Federal Executive Order 11988 (Floodplain Management),
and Federal Executive Order 11990 (Wetland Protection).
(iv) A statement indicating how the proposed action affects the
natural or beneficial values of the floodplain or wetland is
as follows.
The selected remedy protects human health and the environment,
particularly the ecological environment of Cold Creek Swamp,
through isolating and removing the principal contaminated sediments
of the wetland and long-term monitoring. The protection of human
health and the environment is provided by consolidation and
containment of contaminated sediment in the Upper Arm Swamp Zone
and removal of contaminated sediment in the Transition Zone and
containment of any residual contamination within Cold Creek Swamp.
In so doing the risk is reduced for uptake of contaminants into
biota which in turn reduces any risk to humans ingesting
contaminated biota. It also reduces risk to groundwater by
containment with a multi-layer cap. In addition, the risk is also
controlled through institutional controls and long-term monitoring.
Only the most heavily contaminated portions of the wetland will be
compromised. To replace the compromised areas, EPA's remedy
requires mitigation. The new diversion channel will be revegetated
in order to create a new wetland. for the capped area Upper Arm
Swamp Zone. The remedy also requires reestablishment of wetlands
in the excavated areas of the Transition Zone. These
reestablished, uncontaminated wetlands will have a higher
functional value than the current contaminated wetlands. The
remedy requires no net loss of wetlands.
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