EPA/ROD/R04-95/237
September 1995
EPA Superfund
Record of Decision:
Stauffer Chemical Company,
(Cold Creek Plant), OU2,
Bucks, AL
8/16/95
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RECORD OF DECISION
SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
STAUFFER CHEM (COLD CREEK PLANT) SUPERFUND SITE
SOURCE OPERABLE UNIT 2 (OU2)
MOBILE COUNTY, ALABAMA
PREPARED BY
U. S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GEORGIA
^
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DECLARATION
of the
RECORD OF DECISION
SOURCE OPERABLE UNIT 2 (OU2)
SITE NAME AND LOCATION
Stauffer Chem (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 the
Source Operable Unit 2 (OU2) for the Stauffer Chem (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. Sectidn 9601 et
seq.. 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 Chem (Cold Creek Plant)
Superfund Site ("the Site").
The State of Alabama, as represented by the Alabama Department of Environmental
Management (ADEM), has been the support agency during the Remedial Investigation and
Feasibility Study process for the Stauffer Chem (Cold Creek Plant) 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
Site, if not addressed by implementing the response action selected in this Record of
Decision (ROD), may present an imminent and substantial endangerment to public health,
welfare and/or the environment.
DESCRIPTION OF SELECTED REMEDY
This operable unit is the second of three at the Stauffer Site. Operable unit one addressed
groundwater contamination and was enumerated by a ROD that was signed by EPA on
September 27,1989. Operable unit three (OU3) addressed the contamination of Cold Creek
Swamp; a ROD was signed September 17,1993. Operable unit two (OU2), which is
enumerated by this Record of Decision, addresses contamination of the source areas at the
Site.
For the Cold Creek LeCreek Wastewater Treatment Pond, the selected remedy is no further
action. For the Cold Creek North Landfill and Cold Creek South Landfill, the selected
remedy is cap maintenance with continued groundwater monitoring. The estimated cost is
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$174,500.
For the contaminated soil of the Old Neutralization Pond the selected remedy consists of
bioremediation of contaminated soil, backfilling, and capping the pond. Major components
are as follows:
• Performance of a treatability study to determine the design and operational
parameters for the ex-situ land treatment of contaminated soil.
• Setup of the treatment pad.
• Excavation of contaminated soil and place it in the treatment cell.
• Periodic fertilization, irrigation, and tilling of the soil until it has reached the
performance standards set out in the ROD and verified by sampling.
• Backfilling excavated areas with clean and treated soil. 4*
• Construction of a cap equivalent to a RCRA Subtitle C cap.
• Conducting groundwater monitoring for 30 years.
• Maintenance of the integrity of the cap.
The estimated cost of this remedy is $927,900. The total estimated cost is $1,102,400.
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. Because the remedy would result in hazardous substances
remaining on-site, a review will be conducted within 5 years after commencement of the
remedial action to ensure that the remedy continues to provide adequate protection of
human health and the environment.
A
RICHARD D. GREEN, ASSOCIATE DIRECTOR OF
SUPERFUND AND EMERGENCY RESPONSE 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 FOR OU2 4
4.0 SCOPE AND ROLE OF OPERABLE UNITS 4
5.0 SUMMARY OF SITE CHARACTERISTICS . 5
5.1 Geology /Physiography/Soil/Sediments 5
5.2 Site Hydrology 6
5.3 Results of Site Remedial Investigation 6
5.3.1 Cold Creek North and South Landfill 6
5.3.2 Cold Creek LeCreek Wastewater Treatment Ponds ' 7
5.3.3 Old Neutralization Pond : 8
4.
6.0 SUMMARY OF SITE RISK 14
6.1 Chemicals of Concern 14
6.2 Human Health Risk '. 14
6.3 Summary of Exposure Assumptions 14
6.3.1 Cold Creek North Landfill 14
6.3.2 Cold Creek South Landfill • 15
6.3.3 Cold Creek LeCreek Wastewater Treatment Pond 15
6.3.4 Old Neutralization Pond / 15
r
6.4 Summary of Toxicity Values 16
6.5 Risk Characterization/Management 16
6.6 Environmental Risk 17
6.7 Cleanup Levels 17
7.0 DESCRIPTION OF ALTERNATIVES 19
7.1 Cold Creek North Landfill and Cold Creek South Landfill 19
7.2 Cold Creek LeCreek Wastewater Treatment Px>nd , 19
7.3 Old Neutralization Pond 19
7.3.1 Alternative No. 1, No Action 19
7.3.2 Alternative No. 2, Composite Cap : 20
7.3.3 Alternative No. 3, Excavation and Off-site Disposal with Cap 20
7.3.4 Alternative No. 4, Excavation and On-site Ex-Situ Land Treatment
with Cap 20
8.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES 22
8.1 Overall Protection of Human Health and the Environment 22
8.2 Compliance with Applicable or Relevant and Appropriate Requirements
(ARARs) , 23
8.3 Long-Term Effectiveness and Permanence 23
i
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8.4 Reduction of Toxicity, Mobility and Volume Through Treatment 23
8.5 Short-Term Effectiveness 23
8.6 Implementability 23
8.7 Cost Effectiveness 24
8.8 Community Acceptance 24
8.9 State Acceptance 24
9.0 SUMMARY OF SELECTED REMEDY -. 25
9.1 Performance Standards for the Old Neutralization Pond 27
9.2 Design Criteria for Soil at the Old Neutralization Pond 27
9.3 Soil Testing at the Old Neutralization Pond 28
9.4 Cost 28
10.0 STATUTORY DETERMINATION 29
10.1 Protection of Human Health and the Environment 29
10.2 Attainment of the Applicable or Relevant and Appropriate Requirements
(ARARs) 29
10.3 Cost Effectiveness 34
10.4 Utilization of Permanent Solutions to the Maximum Extent Practicable 34
10.5 Preference for Treatment as a Principle Element 34
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES 34
APPENDIX A 35
RESPONSIVENESS SUMMARY / 35
APPENDIX B 36
CONCURRENCE LETTER 36
11
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LIST OF TABLES
TABLE 1: SOIL SAMPLING RESULTS, OLD NEUTRALIZATION POND LFI
THIOCARBAMATE CONCENTRATIONS (mg/kg) 13
TABLE 2: CLEANUP LEVELS FOR CHEMICALS OF CONCERN OLD NEUTRALIZATION
POND 18
TABLE 3: SUMMARY OF REMEDIAL ACTION ALTERNATIVES '- 19
TABLE 4: COST ANALYSIS OF ALTERNATIVES 21
TABLE 5: PERFORMANCE STANDARDS FOR SUBSURFACE SOIL OLD
NEUTRALIZATION POND 27
TABLE 6: FEDERAL ARARs FOR OU2 ". 30
111
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LIST OF FIGURES
FIGURE 1: Location of Area Map 1
FIGURE 2: Site Map of Cold Creek Plant Source Areas 3
FIGURE 3: Generalized Geologic Cross Section B-B' 10
FIGURE 4: Slant Soil Boring Locations for South Landfill Cold Creek LeCreek Wastewater
Treatment Pond and Old Neutralization Pond 11
FIGURE 5: Old Neutralization Pond Soil Boring Locations from LFI 12
IV
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RECORD OF DECISION
STAUFFER CHEM (COLD CREEK PLANT) SUPERFUND SITE
SOURCE OPERABLE UNIT 2
MOBILE, ALABAMA
1.0 SITE LOCATION AND DESCRIPTION
The Stauffer Chem (Cold Creek Plant) Superfund Site is located in Mobile County, on
Highway 43, in Bucks, Alabama, approximately 25 miles north of the city of Mobile (Figure
1). The Cold Creek Plant encompasses approximately 220 acres situated between Highway
43 toward the west and the Mobile River toward the east.
SOLE: O
FIGURE 1: Location of Area Map
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Surrounding land use in the vicinity of the Site is predominantly industrial, related to
chemical processing and electrical power generation. The Alabama Power Company Barry
Steam Generating Plant is located immediately north of the Site. Other major chemical
processing facilities surround the Site to the north, west, and south. The Stauffer Chem
(LeMoyne Plant) Superfund Site borders the Site to the south. Timber production (southern
pine) is the other major land use in the immediate vicinity. Most land east of the project
site (across the Mobile River) is undeveloped riverbottom swamp with some timber
harvesting use. However, some small residential communities are located within a three
mile radius.
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
Both the Site and the adjacent LeMoyne Plant Superfund Site were previously owned by the
Stauffer Chemical Company. Stauffer operated an agricultural chemical facility at the Site,
and a multi-product chemical manufacturing facility at the adjacent LeMoyne Plant. Both
properties were acquired by ICI Americas Inc. in 1986, and shortly thereafter the LeMoyne
Plant was sold to a company now named Akzo Nobel. The Cold Creek Plant, which is the
subject of this proposed plan, is currently owned by Zeneca, Inc. the successor to ICI
Americas. The Stauffer Chem (Cold Creek Plant) and (LeMoyne Plant) Superfund Sites are
two separately listed NPL Sites.
The Cold Creek Plant has been in operation since 1966 and has expanded its operations
over the past 30 years. The Plant manufactured, and continues to manufacture a variety of
agricultural chemicals, including thiocarbamates.
In 1986, a Remedial Investigation (RI)/Feasibility Study (FS)' was developed that covers both
this Site and the LeMoyne Plant The 1986 RI/FS divided the Sites into five areas: 1) the
inactive ponds, 2) the Old Carbon Disulfide Plant Wastewater Treatment Pond drainage
line; 3) the landfills; 4) the Cold Creek Swamp, and 5) the groundwater.
The Superfund cleanup remedy for contaminated groundwater (item 5) has been in
operation since 1990. The design for the cleanup of Cold Creek Swamp (item 4) is currently
underway. This proposed cleanup addressed the on-site sources of contamination at the
Cold Creek Plant Site, which includes inactive ponds (item 1) and landfills (item 3). The
cleanup of the Old Carbon Disulfide Plant Wastewater Treatment Pond Drainage Line (item
2) and the inactive ponds and landfills for the LeMoyne Plant will be addressed in a future
cleanup decision.
On August 6,1992, EPA and the PRPs reached a consensus for a three-phased approach to
study the inactive ponds and landfills at the Site. On December 29,1992, EPA approved a
Decision Document which was prepared to assess available information on these areas, to
determine the appropriate course of action at these areas, and to make recommendations for
addressing contamination concerning these areas.
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Four specific areas were identified at the Stauffer (Cold Creek Plant) Site and targeted as
Operable Unit 2 (OU2). They are:
1. Cold Creek North Landfill
2. Cold Creek South Landfill
3. Cold Creek LeCreek Wastewater Treatment Pond
4. Cold Creek Old Neutralization Pond
SOUTH
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TXATWOT PONO
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COLD CREEK LcCREIX WWTP
OLD NEUTRWJZAieN POND
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FIGURE 2: Site Map of Cold Creek Plant Source Areas
3
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3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION FOR OU2
The Satsuma Public Library on Old Highway 43, Satsuma, Alabama, was chosen as the local
information repository for the Site. The public comment period on the proposed plan
preceding this ROD (OU2) was held April 10 - May 9, 1995. A public meeting was held on
April 18, 1995, where representatives from EPA answered questions from approximately 25
people regarding the Site and the proposed plan under consideration. Approximately 25
people attended the meeting.
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 April 10, and April 15,1995.
This decision document presents the selected remedial action for OU2 of the Stauffer Chem
(Cold Creek Plant) Superfund Site, chosen in accordance with CERCLA, as amended by
SARA and to the extent practicable, the NCP. The decision for this Site is based on the
administrative record. The requirements under Section 117 of CERCLA/SARA for public
and state participation have been met for this operable unit.
4.0 SCOPE AND ROLE OF OPERABLE UNITS
As noted in Section 2.0, and as a consequence of the 1986 RI/FS, EPA has organized the
work at this Site and the LeMoyne Plant Superfund Site into three operable units (OUs)
addressing five contaminated area, as follows:
/
OU1: OU1 was designed to address the contamination of the groundwater beneath both the
Cold Creek Plant Site and the LeMoyne Plant Site. The remedy for OU1 was issued
by EPA in September 1989, and the remedy selected was a groundwater pump and
treat system. Three groundwater extraction wells were installed in 1980, and three
more wells were put on line in 1993.
OU:2 OU2 was designed to systematically address a combination of source-area
contamination discovered at the Cold Creek Plant Site including the inactive ponds
and landfills. It specifically addresses the Cold Creek North Landfill, Cold Creek
South Landfill, Cold Creek LeCreek Wastewater Treatment Pond, and the Cold Creek
Old Neutralization Pond. These four sources are addressed in this ROD.
OUS: OUS was designed to address contamination at Cold Creek Swamp which is adjacent
to both the Cold Creek Plant and the LeMoyne Plant. A remedy was issued for OUS
in September 1993, and EPA is currently conducting a fund-lead Remedial Design at
Cold Creek Swamp.
This ROD addresses the actions that EPA proposes for cleanup of the OU2 source-area
contamination at the Cold Creek Plant Site as explained above. The inactive ponds and the
landfills at the adjacent LeMoyne Plant Site, including the Old Carbon Disulfide Plant
Wastewater Treatment Pond and drainage line, will be addressed by EPA in another
remedy selection document that will be specific to the LeMoyne Plant Site.
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5.0 SUMMARY OF SITE CHARACTERISTICS
This is a summary of the major Site characteristics presented in the March 30, 1994 Limited
Field Investigation (LFI) and Remedial Investigation (RI) and the November 4, 1994
Supplemental Focused Feasibility Study for OU2 of the Stauffer Chem (Cold Creek Plant)
Superfund Site.
5.1 Geology/Physiography/Soil/Sediments
The results of the LFI/RI and Focused Feasibility Study 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 estuarine 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.
• Geology beneath the site can be characterized as river/alluvial sediments. Soil boring
and well logs from the initial RI site work showed a silty-day and clayey sand
formation above a dean fine-coarse grained sand sequence changing into a blue-green
day layer. This blue-green clay (aquiclude) occurs at depths about 120 to 135 ft below
ground surface (bgs) along Highway 43 west of the plant decreasing in depth
eastward toward the Mobile River to about 60 ft bis. The top of the aquidude has a
slight dip toward the southwest.
• Shallow unconsolidated sediments are comprised of fine to medium grained, dean
quartz sands, interbedded with day strata, and quartz-gravel beds forming the
shallow sand aquifer. This shallow zone exhibits low to moderate permeabilities
caused by interbedding and discontinuous dayey strata across the site and extends to
depths of 50 to 60 ft along the western area of the site, thinning to depths of 30 to 50
ft along the eastern shoreline area. Lower sands of the shallow aquifer are cleaner,
coarser and more angular with depth, even occurring as V4 to ll/2 inch grain sand
size quartz gravel layers within this lower zone. These coarse, clean sands comprise
the primary water source as they exhibit moderate to relatively high permeabilities
and transmissivities. A 20 ft thick day layer, located beneath the western portion of
the site separates the shallow aquifer into two water-bearing zones and produces
semi-confined conditions in certain areas. Figure 3 shows the location of geologic
cross-section B-B' transacting the plant property. This cross-section passes directly
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through the North and South Landfills, and the Old Neutralization Pondr It begins
north of the North Landfill, extending south to Well CCM-3 just south of the Old
Neutralization Pond. It then turns southeast, incorporating Well 0-68, and turns
south toward the LeMoyne site and terminates at Well 0-30.
5.2 Site Hydrology
• Surface runoff from the eastern portion of the Cold Creek Plant drains to the Cold
Creek Swamp, which borders the Site to the east Surface runoff on the active
portions of the Cold Creek facility is either captured by the plant drainage system, or
drains to the Cold Creek Swamp. At the Old Neutralization Pond, rainwater tends to
pond due to the locally depressed soil conditions and benning of adjacent structures
and roadways. Surface water runoff at this potential source area is primarily to the
South Rainwater Pond, which supplies dilution water to Zeneca's on-site wastewater
bio treatment plant.
• 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. 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 bejow ground level depending on
the topography. Presently, the direction of flow is tojvard 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.
5.3 Results of Site Remedial Investigation
In 1986, a Remedial Investigation (RI)/ Feasibility Study (FS) was developed that covered
both this Site and the adjacent LeMoyne Plant Sites. In May 1992, EPA required additional
work to complete the RI/FS for the source areas at both Sites. Hence, a Limited Field
Investigation (LFI)/ Remedial Investigation (RI), dated March 1994, was designed to build
upon the initial 1986 study and to determine the nature and extent of contamination in
order to select a cleanup remedy for the on-site sources of contamination. Components of
the LFI/RI sampling program related to this investigation included soil sampling and
groundwater sampling around existing ponds and landfills at the Cold Creek Plant Site.
These include the Cold Creek North Landfill, Cold Creek South Landfill, Cold Creek
LeCreek Wastewater Treatment Pond and Cold Creek Old Neutralization Pond.
5.3.1 Cold Creek North and South Landfill
The North Landfill occupies 1.8 acres at the eastern edge of the active plant area. This
landfill was used from 1970 to 1974 for disposal of process and non-process waste materials.
The process materials were primarily waste products of thiocarbamate production and by-
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product brine filtration. The total waste volume in the North Landfill is estimated to be
30,000 yd3. Currently, the site is smoothly graded, with a cover of thick grass. A chain-link
fence surrounds the landfill. Closure of this landfill, which occurred in 1974, consisted of
the installation of a combination clay and geomembrane cap.
The South Landfill is relatively small, occupying approximately 0.2 acres on the southeast
corner of the Cold Creek Plant. This landfill was used for disposal of process and non-
process waste materials in a similar fashion to the North Landfill. The total waste volume
in the South Landfill is estimated to be 2,100 yd3. The South Landfill was closed in 1974
with a combination clay and geomembrane cap similar to that installed for the North
Landfill. This closure included an impermeable cap extended into a surrounding cut-off
trench and a gas ventilation system; both landfills are currently covered with grassy
vegetation and surrounded by a chain link fence.
Soil borings were taken from around the two landfills at the Cold Creek Plant Site. The
borings were angled at 45 degrees and samples were taken every 5 feet along the axis.
Every other sample was composited to form a composite sample which was analyzed for
priority pollutants. The remaining samples from each boring were analyzed for site specific
compounds (corresponding to 10 ft intervals). No priority pollutants were found in the
composite samples other than low levels of a few metals within the range of the
background. Slant boring samples taken from the area around and under the landfills
showed no detectable levels of site-specific compounds with minor exceptions, the highest
being 1.5 mg/kg molinate, a thiocarbamate pesticide. The synthetic membrane covering
each of the landfills was exposed, sampled and tested. These were found to be intact with
no apparent deterioration.
A statistical evaluation of groundwater chemical data was performed using the Analysis of
Variance (ANOVA) technique. Based on these analyses, it was concluded that no statistically
significant evidence exists to suggest that contaminants are leaching from either landfill.
5.3.2 Cold Creek LeCreek Wastewater Treatment Ponds
The Cold Creek LeCreek WWTP is an active facility used to collect stormwater runoff from
the plant site, treated sanitary wastewater, and utility blowdowns from non-contact cooling
waters of the steam boilers. The water is collected by gravity drains that convey the water
to the pond. Treatment for the pond consists of pH adjustment, oil and grease separation,
and aeration. The pond was constructed and put into operation in 1975 to serve as a check
point for runoff; it has a recompacted clay base, a membrane liner and a leachate collection
system. From approximately December 1975 to June 1993, discharge from the Cold Creek
LeCreek WWTP was to the Mobile River under the old discharge permit. Under the new
discharge permit (effective April 1993), collected wastewater and stormwater are used as
process water for the new onsite wastewater biotreatment plant. The pond perimeter is
encircled by a 4.5 ft high wood post and rail fence, and the adjacent ground is
predominantly gravel covered.
During the initial 1986 RI study, two soil borings were performed at a 45° angle projected
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beneath the Cold Creek LeCreek Wastewater Treatment Pond and advanced to a slant depth
of 50 ft. Samples were taken at every 5 ft interval along the axis of the boring. Samples
from 10, 20, 30, 40 and 50 ft depths were analyzed for six thiocarbamates. No
thiocarbamates were detected in eight of the ten samples collected. One composite soil
sample was also collected from each soil boring during the RI study. These samples were
analyzed for all priority pollutants. Levels detected for inorganics were considered
background. No organic priority pollutants were detected except methylene chloride at 1.28
ppm. Methylene chloride was never manufactured or used at the Cold Creek Site and at
low levels is frequently a laboratory contaminant. Groundwater samples were analyzed for
thiocarbamates. Thiocarbamates detected in the groundwater were present in
concentrations below their target concentration with the exception of one. sample from the
shallow upgradient well (MW-12). Molinate from the fourth round sample from this well
was detected at 15 jig/L, which exceeds the target concentration of 14 ug/L for molinate.
This constituent was found to be below the target concentration in the previous three
sample rounds. Based on these analyses, it was concluded that no statistically, significant
evidence exists to suggest that contaminants have leached from this unit.
5.3.3 Old Neutralization Pond
The Old Neutralization Pond was constructed during 1966-1967 on the southern portion of
the Cold Creek Plant property, and covers approximately one-third of an acre. Closure of
the pond occurred in 1976 by filling with native soil materials. This pond was utilized for
equalization of neutralized wastewater from the Cold Creek Plant, which has manufactured
agricultural herbicides and pesticides since 1966. There is no membrane cap in place on this
pond. Soil within the Old Neutralization Pond consists of 4 ft of sandy-clay fill material,
underlain by a 6 ft thick layer of silty-clay sediments ranging in color from white, tan and
dark brown to gray, which extends to depths of 10 to 11 ft below grade across the pond. A
gray-black clay sediment occurred below this strata and is several feet thick above the
bottom of the pond. This gray-black clay layer appears to contain residual sediments of the
original pond.
Soil samples were collected from the Old Neutralization Pond area during the initial 1986 RI
study. Discrete and composite samples were taken using a similar procedure as described
for the landfill samples. Two soil borings were performed at a 45° angle projected beneath
the pond and advanced to a slant depth of 50 ft (Figure 4). Samples were taken at every 5
ft interval along the axis of the boring. Samples from 10, 20, 30, 40 and 50 ft depths were
analyzed for the six thiocarbamates. The concentrations of the thiocarbamates ranged from
nondetected (ND) to 25 mg/kg. The highest concentrations were detected at a vertical
depth of 14 ft, including EPTC (25 mg/kg), vernolate (8.6 mg/kg), and molinate (6.4
mg/kg). Thiocarbamates detected at a vertical depth of 7 ft ranged from non-detect to 0.3
mg/kg. Molinate was detected to a vertical depth of approximately 28 ft (3.7 mg/kg).
Below 14 vertical ft, all but 3 of the 36 analyses performed were below 1 mg/kg; these were
EPTC at 21 vertical ft-(1.2 mg/kg), molinate at 21 vertical ft (5 mg/kg), and molinate at 28
vertical ft (3.7 mg/kg). One composite sample (composited from the samples at 5,15, 25, 35
and 45 ft depths) was also collected from each boring and analyzed for all priority
pollutants. The concentrations of the inorganics are considered background.
8
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Groundwater samples were analyzed for carbon tetrachloride, carbon disulfide, mercury,
cyanide, thiocyanate, and six thiocarbamates. Molinate was detected in MW-16 at
concentrations ranging from 26 to 400 ug/L. It exceeded the 14 ug/L target concentration
in four consecutive sampling events. Other thiocarbamates were detected below target
concentration levels.
During the 1993 LFI, four vertical borings were completed within the Old Neutralization
Pond, located as shown in Figure 5. Six samples were taken in each of these borings; one at
the surface, then at 3 ft intervals to a depth of 16 ft. Samples were collected using two foot
split spoons. This translates to approximate sample depths of 2, 5, 8,11,14, and 16 ft.
These samples were analyzed for thiocarbamates. Analytical results of both surface and
subsurface sampling is summarized in Table 1. Thiocarbamate contamination was found in
all soil borings at varying concentrations for the individual thiocarbamates. Significant
thiocarbamate levels were generally found at depths ranging from 6 to 16 ft bgs. Soil
boring ONP-SB-1, located in the southwestern portion of the pond, appears to have the
highest overall thiocarbamate concentrations. Maximum thiocarbamate concentrations seem
to be located in the western portion of the Old Neutralization Pond. In the western portion
of the pond, thiocarbamates appear concentrated from 6-8 ft and 14-16 ft. In the South
central portion of the pond, thiocarbamates are predominantly found at the 14-16 ft depth
interval. The eastern portion of the pond displayed elevated concentrations only at the 14-
16 ft depth interval, which were significantly lower than any other sampled portion of the
pond.
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TABLE 1: SOIL SAMPLING RESULTS, OLD NEUTRALIZATION POND LFI
THIOCARBAMATE CONCENTRATIONS (mg/kg)
M^KW^f^M^MfM^S
ONP-SB-1
0-2
3-5
6-8
9-11
12-14
14-16
ONP-SB-2
0-2
3-5
6-8
9-11
12-14
12-14D
14-16
ONP-SB-3
0-2
3-5
6-8
9-11
12-14
12-14D
14-16
ONP-SB-4
0-2
3-5
6-8
9-11
9-1 1D
12-14
14-16
ONP-STEAM
ONP-BL-1
ONP-BL-2
ONP-FBL
yf:-K':'fy-^yff--
-------
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.
From the results of the LFI/RI, it was determined that under current conditions the Cold
Creek North Landfill, the Cold Creek South Landfill, and the Cold Creek LeCreek
Wastewater Treatment Pond, do not pose a risk from exposure to soil, surface water, and
groundwater. The LFI/RI showed that the Old Neutralization Pond does pose a risk from
exposure to soil and groundwater. Mainly, the risk is from the sub-surface soil
contamination leaching into the underlying aquifer. EPA knows that the groundwater
underlying the Old Neutralization Pond is contaminated with thiocarbamates.. Cleanup of
this groundwater contamination is underway in the OU1 remedy; cleanup is also .necessary
for the Old Neutralization Pond. •
6.1 Chemicals of Concern
The contaminants of potential concern (COPCs) for the Stauffer Chem (Cold Creek Plant)
Superfund Site are six thiocarbamate herbicides: EPTC, vernolate, pebulate, molinate,
butylate, and cycloate.
6.2 Human Health Risk
The Baseline Risk Assessment (BRA) characterized potential,current and future risks to
human health and the environment from exposure to chemjcals found at the Site. The BRA
reviewed several potential exposure scenarios for the site.
6.3 Summary of Exposure Assumptions
6.3.1 Cold Creek North Landfill
Exposure pathways for the Cold Creek North Landfill consist of soil, surface water, and
groundwater. Pathways considered for soil exposures include direct dermal contact with
surficial soil, inhalation of airborne fugitive dust, incidental ingestion of surficial soil, and
inhalation of any volatilized subsurface compounds. Exposure routes are incomplete
because of the existing cap at the North Landfill. Exposure pathways considered for surface
water would only be those from contact with storm-water runoff. Since this is a graded,
filled site with no signs of soil erosion, and is capped with an impermeable membrane liner,
it was concluded that there is no potential for contamination of surface water run-off.
Therefore, no complete exposure pathways via surface water are anticipated. Ingestion is
the exposure pathway of concern for groundwater. Molinate was the only COPC detected
above the EPA target concentration of 14 ug/L in the shallow upgradient well (MW-13) at
concentrations ranging from <1.0 to 26 ug/L. It is believed that this contamination is
associated with an upgradient source; most likely the Old Neutralization Pond. Therefore,
it is concluded that no COPC are leaching from this unit.
14
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6.3.2 Cold Creek South Landfill
Exposure pathways for the Cold Creek South Landfill consist of soil, surface water, and
ground water. Pathways considered for soil exposures include direct dermal contact with
surficial soil, inhalation of airborne fugitive dust, incidental ingestion of surficial soil, and
inhalation of any volatilized subsurface compounds. Exposure pathways are not anticipated
to be complete via the soil media for all routes of exposure at the Cold Creek South
Landfill. Exposure pathways considered for surface water would only be those from
contact with storm-water runoff. Since this is a graded, filled site with no signs of soil
erosion, and is capped with an impermeable membrane liner, it was concluded that there is
no potential for contamination of surface water run-off. Therefore, no risks attributable to
any exposures via surface water are anticipated. Ingestion is the exposure pathway of
concern for groundwater. Upgradient and down gradient monitoring wells were sampled
for thiocarbamates and none were detected above the EPA target levels. It was concluded
that no statistically significant evidence exists to suggest that contaminants are leaching
from this unit.
6.3.3 Cold Creek LeCreek Wastewater Treatment Pond :
Exposure pathways considered for surface water include direct dermal contact ancl
incidental ingestion of pond treatment water and inhalation of volatilizing compounds. The
potential for dermal or ingestion exposure to occur is very low, as this is a lined, active
facility, although these exposure pathways could occur during some maintenance or routine
operations at the pond. The frequency of these events is expected to be very low. Given
the infrequent opportunity for exposure, surface water and sediments are not a concern.
Ingestion is the exposure pathway of concern for groundwater. Upgradient and
downgradient monitoring wells were sampled, and thiocarbamates detected in the
groundwater were below their target concentrations except for one quarterly event, in which
molinate was detected at 15 ug/L in an upgradient well (MW-12), just above the 14 ug/L
target concentration. However, it was concluded that no statistically significant evidence
exists to suggest that contaminants are leaching from this unit.
6.3.4 Old Neutralization Pond
Exposure pathways for the Old Neutralization Pond consist of soil, surface water, and
groundwater exposure. Pathways considered for soil exposures include direct dermal
contact with surficial soil, inhalation of airborne fugitive dust, and incidental ingestion of
surficial soil. Use of the pond ended when it was filled with native soil, and the pond is
now covered with grass. Exposures via soil at this Site are not likely to occur due to the
highly vegetated nature of the Site, which eliminates the potential for generation of fugitive
dust. The grassy cover reduces the potential for dermal contact and incidental ingestion, as
does the depth of the contaminants detected at elevated concentrations (6 to 16 ft). There is
no current functional use of this area, either for storage or for maintenance. Exposure
pathways do not exist via the soil media for all routes. Exposure pathways considered for
surface water would only be those from contact with stormwater runoff. The Old
Neutralization Pond was believed to have been covered with clean topsoil prior to seeding
with grass. Composite soil samples were taken from 0 to 2 feet yielding results never
exceeding 0.55 ppm of the individual thiocarbamate compounds, and therefore, appear to
substantiate this. Because the surface is grass-covered, it is not expected that soil would be
15
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carried by surface water runoff. Therefore, it is concluded that no exposure to any
contaminants exist from surface water runoff. Ingestion is the exposure pathway of concern
for groundwater. Upgradient and downgradient monitoring wells were sampled, and
thiocarbamates detected in the groundwater were below their target concentrations except
for molinate which was detected in the shallow downgradient well (MW-16) at
concentrations ranging from 26 to 400 ug/L. Molinate concentrations exceeded the 14 ug/L
target concentration in four consecutive sampling events. It was concluded that molinate
and cycloate are leaching from this unit. The molinate detected in upgradient wells for the
other SWMUs is likely to have come from the leaching of the Old Neutralization Pond.
6.4 Summary of Toxicity Values
Toxicity values are used in conjunction with the results of the exposure assessment to
characterize site risk. EPA has developed critical values for carcinogens and
noncartinogens. The Old Neutralization Pond exhibits a potential risk through leaching of
thiocarbamate constituents to the groundwater and potential future use of contaminated
groundwater. Cleanup values for subsurface soil are based upon this leaching to
groundwater scenario. Groundwater cleanup values were calculated as part of OJJ1 for the
Site. The pertinent toxicity values for the thiocarbamate constituents are set out in the OU1
ROD and reiterated below.
Noncarcinogens
Butylate
Cycloate
EPTC
Molinate
Pebulate
Vernolate
RfD
mg/kg/day
5 x 10"2
NE
3xia2
zxicr3
NE
1 x 10"3
Maximum
concentration
mg/L
0.014
0.007
1.200
0.231
0.002
0.009
Mean
Concentration
mg/1
0.004
0.003
0.006
0.010
0.001
0.008
Hazard
Quotient
Max. /Mean
7.84xlO"3/2.2xlO"3
1.1 75.6x1 O"3
3.2/1.4X10"1
2.5X1Q-V2.2X10"1
NE - None Established
6.5 Risk Characterization/Management
EPA considers individual excess cancer risks in the range of IxlO"4 to IxlO"6 as protective;
however the IxlO"6 risk level is generally used as the point of departure for setting cleanup
levels at Superfund sites. The point of departure risk level of IxlO"6 expresses EPA's
preference for remedial actions that result in risks at the more protective end of the risk
range. There is no carcinogenic risk from the chemicals of concern in OU2.
16
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Potential concern for noncarcinogenic effects of a single contaminant in a single medium is
expressed as the Hazard Quotient (HQ) (or the ratio of the estimated intake derived from
the contaminant concentration in a given medium to the contaminant's reference dose). A
HQ which exceeds unity, i.e., one (1), indicates that the daily intake from a scenario exceeds
the chemical's reference dose. By adding the HQs for all contaminants within a medium or
across all media to which a given population may reasonably be exposed, the Hazard Index
(HI) can be generated. The HI provides a useful reference point for gauging the potential
significance of multiple contaminant exposures within a single medium or across media. A
HI which exceeds unity indicates that there may be a concern for potential health effects
resulting from the cumulative exposure to multiple contaminants within a single medium or
across media. Molinate and EPTC exhibit HQs above 1, and therefore, a noncarcinogenic
risk.
6.6 Environmental Risk
OU2 is located in a highly industrialized area with numerous large chemical facilities. It is
located within the operating portion of the Cold Creek Plant. Adjacent to the OU2 is the
upper portion of Cold Creek Swamp. The portion of the swamp closest to the Site supports
an ecosystem dominated by submerged aquatic and emergent species and includes
peripheral and island areas of scrub-shrub and scattered tree species. Ponds are dominated
by sort rush, red-top panic grass or dotted smartweed. Shrub margins are dominated by
red maple. The environmental risks associated with Cold Creek Swamp and associated
remedial actions are enumerated in the ROD for Cold Creek Swamp (OU3) dated September
17,1993.
6.7 Cleanup Levels
Cleanup levels were established to ensure no exposure to urtsafe levels of site-related
chemicals. Cleanup levels are either the Federal Maximum Contaminant Limit (MCL), the
state standards, or the risk-based concentration. EPA determines the amount of cleanup
necessary at a site by establishing health-based cleanup levels when Federal or state
standards have not been set for contaminants in soil or for some groundwater contaminants.
To determine these levels, EPA quantifies risks posed by cancer-causing contaminants and
those known to cause other health effects. This risk range of IxlO"4 to IxlO'6 means that
exposure to site-specific contaminants as defined in the risk assessment would result in an
estimated increase individual chance of developing cancer by one in 10,000 to one in
1,000,000. For non-cancer causing risks, EPA compares the highest dose known to be safe
(or not to cause harmful effects) to the estimated dose from exposure to levels found at the
Site to determine the cleanup level.
Soil cleanup levels have been calculated using the SUMMERS Model to relate existing
groundwater target concentrations to corresponding soil contaminant levels. In order to
calculate cleanup target levels, downgradient groundwater concentrations for each of the six
thiocarbamates were set at the groundwater target concentrations. Upgradient groundwater
concentrations were set at zero. The calculated soil cleanup goals are reported in Table 2.
These soil cleanup levels were determined to be protective of groundwater.
17
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TABLE 2:
CLEANUP LEVELS FOR CHEMICALS OF CONCERN
OLD NEUTRALIZATION POND
CONSTITUENT
EPTC
Vernolate
Pebulate
Molinate
Butvlate
Cycloate
SUB-SURFACE
SOIL3
(mg/Kg)
25.74
2.298
1.971
1.464
b
2.187
Subsurface soil cleanup levels were calculated using the Summers model to relate existing ground water cleanup
levels (OU1) to corresponding soil contaminant levels, allowing movement to groundwater.
The modeling results yielded a sub-surface soil level of 195.63 mg/Kg (milligrams per kilogram) which indicates no
remedial action is necessary for this constituent. 4
18
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7.0 DESCRIPTION OF ALTERNATIVES
7.1 Cold Creek North Landfill and Cold Creek South Landfill
The North and South Landfills were closed in 1974 with a multi-layer cap, gas vent system,
and stormwater runoff controls. A risk analysis concluded that surface soil does not pose a
risk and that currently the landfills are not leaching contaminants to groundwater. Based
upon these results, a presumptive remedy is being proposed for the Cold Creek North and
South Landfills. The proposed cleanup is for continued monitoring of the groundwater and
continued maintenance of the cap of each landfill. The estimated cost for this remedy is
$174,500.
7.2 Cold Creek LeCreek Wastewater Treatment Pond
Cold Creek LeCreek Wastewater Treatment Pond is an active treatment unit and the
discharge is monitored as part of another environmental authority (NPDES). No leachate
was found in the leachate collection system and based on the groundwater monitoring EPA
has concluded that currently the pond is not leaking. Therefore, no further action is
required for the Cold Creek LeCreek Wastewater Treatment Pond. No cost is associated
with this remedy. *
7.3 Old Neutralization Pond
Four alternatives are presented in this ROD for the remediation of contaminated soil in the
source operable units (OU2) at the Stauffer Chem (Cold Creek Plant) Superfund Site (Table
3). These alternatives are discussed in detail in the final Focused Feasibility Study dated
November 4,1994.
TABLE 3: SUMMARY OF REMEDIAL ACTION ALTERNATIVES
FOR THE OLD NEUTRALIZATION POND
COLD CREEK PLANT SWMUs
ALTERNATIVES
1
, 2
3
"4* <
DESCRIPTIONS
No Action
,'„',,*
;,,' 'Csite Cap ' / '"•••, ,. , ', ' •
Excavation and Off-site Disposal with Cap
-,?: ;'ExcavMokaj^'C^rsite;Bx-Sltu;L'aBdTreatmeni with Cap' 'I
Old Neutralization Pond
7.3.1 Alternative No. 1, No Action
The no action alternative provides a baseline for comparing other alternatives. Under this
alternative, no further action would be taken at the Site. However, minimum activity
would be undertaken to limit threat to human health and the environment. A fence would
be installed and signs posted to warn and restrict on-site plant employees and visitors.
19
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However, groundwater monitoring would nevertheless continue in association with OU1
activities. Additionally, semi-annual monitoring of upgradient and downgradient shallow
and deep wells would be performed. The estimated cost of this alternative is $64,300. (See
Table 4.)
7.3.2 Alternative No. 2, Composite Cap
This alternative would involve the placement of a multi-layer (composite) cap above the Old
Neutralization Pond to prevent rainwater infiltration into the underlying contaminated soil.
Prior to installation of the cap, a dewatering well would be installed to dewater the perched
water that was found in the filled pond. Following capping, the site would be graded and
seeded to establish a good vegetative cover to prevent erosion. Final grading would be
completed to promote runoff flow to the plant drainage collection system, which is
subsequently discharged to Zeneca's wastewater biotreatment plant.
Following completion of the multi-layer cap installation, the dewatering well would be
gauged monthly to determine infiltration rates from the surrounding saturated clays. An
extraction program would then be established to regularly remove the contaminated waters
which accumulate in the well, until such a time when water no longer collects in sufficient
quantity to justify extraction. The estimated cost of this alternative is $284,800. (See Table
4.)
7.3.3 Alternative No. 3, Excavation and Off-site Disposal with Cap
This alternative would involve the excavation of the source area contaminants
(approximately 6,500 sq yds) removing 5,700 pounds of contaminated soil from the Old
Neutralization Pond, and placement directly into trucks for subsequent transport to an off-
site regulated landfill. After contaminated soil within the p'ond have been removed, the
pond would be backfilled with clean soil. A small percentage (less than 10%) of
contaminated soil above the cleanup level would be left below the 16 foot level due to the
extreme engineering difficulty of removing that soil. It is not expected that this small
percentage would significantly contribute to groundwater contamination, although the
groundwater cleanup standards set out in OU1 must be attained for overall cleanup. A
composite cap would then be installed above the Old Neutralization Pond to prevent
rainwater infiltration into the underlying soil. Following capping, the site would be graded
and seeded to establish a good vegetative cover to prevent erosion. Final grading would be
completed to promote runoff flow to the plant drainage system, which is subsequently
discharged to Zeneca's wastewater biotreatment plant. The estimated cost of this alternative
is $1,744,500. (See Table 4.)
7.3.4 Alternative No. 4, Excavation and On-site Ex-Situ Land Treatment with Cap
This alternative would involve a source area removal (approximately 6,500 sq yds) in
conjunction with on-site biotreatment of thiocarbamate contaminants, followed by capping.
It would include: (a) excavation, (b) ex-situ bioremediation (land treatment), and (c) capping.
The excavation and capping procedures for Alternative No. 3 would be adopted for this
remedial alternative. However, instead of contaminated soil being disposed off-site, the
contaminated soil would bi treated on-site using bioremediation technology. The treatment
is expected to be completed in approximately one year after excavation. Prior to excavating
20
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the contaminated soil, a treatability study would be conducted to determine the optimal
conditions under which biodegradation occurs.
A plastic covering would be placed over the treatment area to prevent the escape of
volatilized contaminants, if a need arises for gas emission controls during land farming
operations. Approximately once per month, the plastic covering would be removed, and
the soil would be watered and tilled (aerated). Fertilization and pH adjustment would
occur as needed. Samples would be collected periodically to determine whether the soil
have achieved the desired soil target level. The exact sampling schedule would be
determined during the design phase of the project. Confirmatory sampling would be
performed at the end of treatment to insure that the thiocarbamate levels in the soil are
below target concentrations. The excavated pond then would be backfilled with the
treated/clean soil from the biotreatment process. Once the pond is backfilled, a cap would
be installed over the area. As in Alternative No. 3, a small percentage of contaminated soil
above the cleanup level would be left below the 16 foot interval. The estimated cost for this
remedy would be $927,900. (See Table 4.)
TABLE 4:
COST ANALYSIS OF ALTERNATIVES
Alternative
No. 1
No. 2
No. 3
No. 4
Description
No action
Composite Cap
Excavation and Off-site
Disposal with Cap
Excavation and On-site
Ex-Situ Land Treatment
with Cap
Capital Cost
$
33,600
175,500
1,651,300
834,700
Annual O&M
$
/ 2,000
7,110
6,060
6,060
Present Worth
$
64,300
284,800
1,744,500
927,900
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8.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
This section of the ROD provides the basis for determining which alternative provides the
best balance with respect to the statutory balancing criteria in Section 121 of CERCLA and
in Section 300.430 of the NCR The NCP categorizes the nine evaluation criteria into three
groups:
1. THRESHOLD CRITERIA - overall protection of human health and the
environment and compliance with ARARs (or invoking a waiver) are threshold
criteria to be eligible for selection;
2. PRIMARY BALANCING CRITERIA - long-term effectiveness and permanence;
reduction of toxitity, mobility, or volume; short-term effectiveness;
implementability, and cost are primary balancing factors used to weigh major
trade-offs among alternative hazardous waste management strategies; and
3. MODIFYING CRITERIA - state and community acceptance are modifying
criteria that are formally taken into account after public comment is received on
the proposed plan and incorporated in the ROD.
The selected alternative must meet the threshold criteria and comply with all ARARs or be
granted a waiver for compliance with potential Applicable or Relevant and Appropriate
Requirements (ARARs) and To-Be-Considered criteria (TBCs). 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, assesses the public's and the state agency's
acceptance of the criteria. EPA may modify aspects of a specific alternative based upon this
criteria.
The following analysis is a summary of the evaluation of alternatives for remediating OU2
of the Stauffer Chem (Cold Creek Plant) Superfund Site under each of the criteria. A
comparison is made between each of the alternatives for achievement of a specific criterion.'
THRESHOLD CRITERIA
8.1 Overall Protection of Human Health and the Environment
Alternative 1 (no action) would not be protective of human health and the environment,
since thiocarbamates would continue to leach to groundwater from the Old Neutralization
Pond. Alternative 2 (capping) would provide better protection than Alternative 1.
Alternative 2 would encapsulate the waste but would not remove it permanently.
Alternative 3 (excavation/off-site disposal) and Alternative 4 (excavation/ bioremediation)
would provide the best protection, since contaminants would be reduced to safe levels.
Biotreatment of the top 16 feet of contaminated soil would permanently remediate that soil.
22
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8.2 Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
Key ARARs:
40 CFR Part 264: Standards for Owners and Operators of Hazardous Waste Treatment,
Storage, and Disposal (TSD) Facilities
40 CFR Part 270: Land Disposal Restrictions
Alternative 1 (no action) and Alternative 2 (capping) would not meet the cleanup levels.
Alternative 3 (excavation/off-site disposal) and Alternative 4 (excavation/bioremediation)
would meet cleanup levels and pertinent ARARs.
PRIMARY BALANCING CRITERIA
8.3 Long-Term Effectiveness and Permanence
Alternative 1 would not provide long-term effectiveness since no action would be taken and
elevated levels of thiocarbamate contamination would continue to migrate to the
groundwater. Alternative 2 (capping) would provide some long-term effectiveness but the
potential would still exist for contamination to slowly leach to groundwater and this would
not be a permanent remedy. Alternative 3 (excavation/off-site disposal) would have good
long-term effectiveness but would not be a permanent remedy since contaminant^ would be
transported to another landfill. Alternative 4 (excavation/bioremediation) would be
effective in the long-term and is expected to reduce the overall risk to its lowest level.
Bioremediation of the top 16 feet of contaminated soil would permanently remediate that
soil.
8.4 Reduction of Toxicity, Mobility and Volume Through Treatment
Alternative 1 (no action), Alternative 2 (capping), and .Alternative 3 (excavation/off-site
disposal) would not be treatment options and therefore would not reduce toxicity, mobility
and volume through treatment. Only Alternative 4 (excavation/ bioremediation) would be
a treatment option and would reduce toxicity, mobility, and volume.
8.5 Short-Term Effectiveness
Alternative 1 has no short-term effectiveness since no action would be taken and
contaminants would continue to leach to groundwater. This would also be true for
Alternative 2 (capping). Alternative 3 (excavation/off-site disposal) would provide short-
term effectiveness but would entail exposure to the community and workers during
excavation and shipment. Alternative 4 (excavation/bioremediation) would provide some
short term effectiveness since contaminated soil would be excavated, but there would be a
potential for exposure during the bioremediation process.
8.6 Implementability
Alternative 1 (no action) would require no remedial construction or operation, therefore it
would be easily implemented. Alternative 2 (capping) is a proven technology and also
easily implemented. Alternative 3 (excavation/off-site disposal) would be more difficult
since it would involve excavation of material and shipment off-site. Distance to an approved
landfill is about 150 miles. Alternative 4 (excavation/ bioremediation) would be the most
difficult of the four alternatives since the bioremediation treatment would require a
treatability study and continued operation and maintenance. But this alternative would still
23
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be relatively easy to implement.
8.7 Cost Effectiveness
Table 4 summarized the estimated capital and annual operation and maintenance costs for
the source area alternatives evaluated. The cost variations for Alternatives 1 and 2 from
actual costs will be minimal. However, the cost variations for Alternatives 3 and 4 from
actual costs will likely be higher compared to Alternatives 1 and 2. (See Table 4).
MODIFYING CRITERIA
8.8 Community Acceptance
EPA has determined community acceptance of the preferred alternative after considering
comments received during the public comment process associated with the Proposed Plan.
A Responsiveness Summary has been included as an attachment to this ROD in Appendix
A explaining how the comments were addressed.
8.9 State Acceptance t
EPA has consulted with the Alabama Department of Environmental Management and
received a letter dated June 15,1995 indicating State concurrence on the ROD, which will
document EPA's remedy selection. See Appendix B.
24
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9.0 SUMMARY OF SELECTED REMEDY
Based upon CERCLA, The NCP, EPA Policy, and the comparison of cleanup alternatives in
the Focused Feasibility Study, EPA has chosen Alternative #4 as the preferred remedy for
the source areas (OU2) of the Stauffer Chem (Cold Creek Plant) Site.
Cold Creek North Landfill and Cold Creek South Landfill
For the Cold Creek North and South Landfills, EPA's proposed remedy entails limited
action. Since these source areas do not pose a risk under their current conditions, the
proposed action would be for development and implementation of landfill operation and
maintenance to ensure current cap integrity and access control. A groundwater monitoring
program would also be developed and implemented for the six thiocarbamate constituents.
The estimated cost of this remedy is $174,500.
Cold Creek LeCreek Wastewater Treatment Pond
For the Cold Creek LeCreek Wastewater Treatment Pond, EPA's preferred remedy is for no
further action. This is an active facility and is currently in compliance with applicable
permits as part of the NPDES program. Since it is under the jurisdiction of an existing
environmental program and the area is not a contributing source to the groundwater
contamination, no further action is justified for this unit and there would be no cost..
Old Neutralization Pond
EPA's preferred remedy for the Old Neutralization Pond is Alternative #4, Excavation and
On-site Ex-situ Land Treatment with Cap. This remedy includes excavation of the source
area in conjunction with on-site land treatment (bioremediation) of thiocarbamate
contaminants to levels protective of groundwater, backfilling, followed by capping. The
major components of the remedy include:
• Performance of a treatability study to determine the appropriate design and '
operational parameters for the ex-situ land treatment of contaminated soil.
• Setup of the treatment pad.
• Excavation of contaminated soil and placement into the treatment cell.
• Periodic fertilization, irrigation, and tilling of soil until reaching the performance
standards set out in this ROD and verified by sampling.
• Backfilling excavated areas with clean and/or treated soil.
• Construction of a cap equivalent to a RCRA Subtitle C cap.
• Conducting groundwater monitoring for 30 years.
• Maintenance of the integrity of the cap.
25
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The contaminated soil will be treated on-site using bioremediation technology, which is
expected to be completed in approximately one year after excavation. This technology
includes construction of a bioremediation pad and mixing of sand to the clayey soil of the
Old Neutralization Pond to increase permeability. The treatment pad will be bermed and
lined to control drainage. Fertilizer, enzymes, and lime will be added to the contaminated
soil on the treatment pad, which will be aerated and mixed. An irrigation system will be
installed on top of the soil to maintain proper moisture and a drainage system will be
installed below the treatment pad to collect any drainage. Wastewater will be sent to the
plants wastewater treatment system. Following the initial tilling of the soil, a plastic cover
will be placed over the treatment area to prevent the escape of volatilized contaminants. If
necessary, a gas collection system will be installed. Periodic tilling will continue and ..
verification sampling will occur until the soil has been treated to the performance standard.
Prior to excavating die contaminated soil, a treatability study will be conducted to
determine the optimal conditions under which biodegradation occurs. A small percentage
(less than 10%) of contaminated soil above the cleanup level will be left below the 16 foot
level. This amount will be left due to the extreme engineering difficulty and low .cost-
benefit of removing that soil. It is not expected that this small percentage will significantly
contribute to groundwater contamination.
A plastic covering will be placed over the treatment area to prevent the escape of volatilized
contaminants. Approximately once per month, the plastic covering will be removed, and
the soil will be watered and tilled (aerated). Fertilization and pH adjustment will occur as
needed. Samples will be collected periodically to determine whether the soil have achieved
the performance standard set out in this ROD. The schedule of events will be determined
during the design phase of the project. Confirmatory sampling will be performed at the
end of treatment to insure that the thiocarbamate levels in th" e soil are below target
concentrations. The excavated pond then will be backfilled with treated/clean soil from the
biotreatment process. Once the pond is backfilled, a cap will be installed over the area.
EPA is designating the areas outlined in Figure 2 as corrective action management units
(CAMUs) for purposes of cleaning up the contaminated soil with an ex-situ bioremediation
process. CAMU #1 is designated for the Old Neutralization Pond. CAMU #2 is designated
for the biotreatment pad(s). The biotreatment pad(s) will be lined for protection. After
bioremediation is complete, the biotreatment pad(s) will be cleaned and decontaminated.
Since the biotreatment pad(s) will be clean-closed, no post closure requirements are
necessary. Following capping of the Old Neutralization Pond, the site will be graded and
seeded to establish a good vegetative cover to prevent erosion. Final grading will be
completed to promote runoff flow to the plant drainage system, which is subsequently
discharged to the Site's wastewater biotreatment plant. Groundwater monitoring is also
required. The estimates cost for this cleanup is $927,900.
The total cost for OU2 including Cold Creek North and South Landfills, Cold Creek
LeCreek Wastewater Treatment Pond, and the Old Neutralization Pond is approximately
$1,102,400.
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9.1 Performance Standards for the Old Neutralization Pond
The top 16 feet of soil from the Old Neutralization Pond shall be excavated. The excavation
shall comply with ARARs, including, but not limited to, OSHA and state standards.
Excavated contaminated soil, sludge, and related material, shall be treated using a
bioremediation treatment remedy to the performance standards set out in Table 5. All
treatment and disposal shall comply with applicable or relevant and appropriate
requirements (ARARs), including RCRA and NPDES. Treated soil will be used to backfill
the Old Neutralization Pond.
•
9.2 Design Criteria for Soil at the Old Neutralization Pond
The design, construction, and operation of the bioremediation treatment remedy shall be
conducted in accordance with all ARARs, including but not limited to the RCRA
requirements set forth in 40 C.F.R. Part 264 (Subpart F). The bioremediation treatment area
shall be lined and bermed to prevent infiltration and runoff. All design specifications will
be developed through the remedial design process to meet the performance standards set
out in Table 5. The cap design for the Old Neutralization Pond shall be consistent with a
RCRA hazardous waste cap standard protocol and guidance.
TABLE 5:
PERFORMANCE STANDARDS
FOR SUBSURFACE SOIL
OLD NEUTRALIZATION POND
CONSTITUENT
EPTC
Vernolate
Pebulate
Molina te
Butylate
Cycloate
SUB-SURFACE
SOIL' :
(mg/Kg)
25.74
2.298
1.971
1.464
b
2.187
Subsurface soil cleanup levels were calculated using the Summers model to relate existing groundwater cleanup
levels (OU1) to corresponding soil contaminant levels, allowing movement to groundwater. .
The modeling results yielded a sub-surface soil level of 195.63 mg/Kg (milligrams per kilogram) which indicates no
remedial action is necessary for this constituent.
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9.3 Soil Testine at the Old Neutralization Pond
Soil testing shall be conducted at the Old Neutralization Pond to determine the effectiveness
of meeting the soil performance standards set out in Table 5. Performance will be met
when the confirmatory sampling shows all samples have been remediated to a level at or
below the performance standard for each constituent set out in Table 5. Confirmatory
sampling will include testing of decontaminated soil after exiting the bioremediation
treatment unit. All such soil shall meet the performance standards.
9.4 Cost
The present worth cost of the excavation with on-site land treatment and cap remedy is
estimated to be $927,900. This cost includes planning and design fees, as well as operation
and maintenance. The capital cost is $834,700 with an O&M of $6,060. The total cost for
the treatment remedy on the Old Neutralization Pond and O&M on the landfills is
$1,102,400.
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10.0 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.
Because the remedy would result in hazardous substances remaining on-site, a review will
be conducted within 5 years after commencement of the remedial action to ensure that the
remedy continues to provide adequate protection of human health and the environment.
10.1 Protection of Human Health and the Environment •
The selected remedy protects human health and the environment through isolation and
treatment of substances posing a threat at OU2 of the Site. The selected remedy provides
protection of human health and the environment by eliminating, reducing and controlling
risk through treatment, engineering and/or institutional controls. The contaminated soil of
the Old Neutralization Pond will be treated and covered with a cap equivalent with those
used for hazardous waste. The Cold Creek North Landfill and Cold Creek South Landfill
will be maintained to insure their integrity and the groundwater monitoring system will
detect any potential for future groundwater contamination.
t
10.2 Attainment of the Applicable or Relevant and Appropriate Requirements (ARARs)
Remedial Actions performed under CERCLA must comply with all ARARs. All alternatives
considered for OU2 of the Stauffer Chem (Cold Creek Plant) Superfund Site were evaluated
on the basis of the degree to which they complied with these requirements. The selected
remedy was found to meet or exceed the following ARARs. See Table 6 for a list of
potential ARARs and TBCs.
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TABLE 6: FEDERAL ARARs FOR OU2
CLEAN WATER ACT (CWA) - 33 U. S. C. §§ 1251-1376
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.
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 solid 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
Establishes 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 facilities which treat, store or
dispose of hazardous wastes.
Federal Register/Vol. 58, No. 29
February 16,1993
40 CFR Part 260 et al.
Corrective Action Management Units
and Temporary Units; Corrective Action
Provisions; Final Rule
Finalizes provisions for corrective action management
units (CAM Us) and temporary unfts 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 prohibited waste may be
land disposed.
Federal Register/Vol. 60, No. 27
February 9, 1995
40 C.F.R. Parts 261,271, and 302
Hazardous Waste: Identification and
Listing; Carbamate Production; Final
Rule
Lists carbamate wastes as hazardous wastes under
RCRA. This includes carbamate chemicals which are
formulated for use as pesticides and in the production
of synthetic rubber. It includes thiocarbamate wastes.
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TABLE 6: FEDERAL ARARs FOR OU2
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.
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TABLE 6: STATE ARARs FOR OU2
ALABAMA HAZARDOUS WASTE MANAGEMENT AND MINIMIZATION ACT
CODE OF ALABAMA §§ 22-30-1 et seq.
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 describes those circumstances under which
an otherwise prohibited 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 1, p. 10-15
State surface water quality standards for the protection
of human health and aquatic life.
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 PLANT SOURCE AREAS.
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 PLANT SOURCE AREAS, ADDRESS PROBLEMS OR SITUATIONS SUFFICIENTLY SIMILAR TO THOSE
ENCOUNTERED AT THE COLD CREEK PLANT SOURCE AREAS THAT THEIR USE IS WELL SUITED TO THE SITE.
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TABLE 6: TO-BE-CONSIDERED (TBCs) DOCUMENTS FOR OU2
DOCUMENT TYPE
DESCRIPTION
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 et seq.
Alabama Proposed Regulations on Municipal
Solid Waste Landfills
Chapter 335-13-4
Permit Requirements
Proposes standards for Solid Waste Disposal
Facilities.
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.
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10.3 Cost Effectiveness
Cost effectiveness is determined by comparing the cost of all alternatives being considered
with their overall effectiveness to determine whether the costs are proportional to the
effectiveness achieved. EPA evaluates the incremental cost of each alternative as compared
to the increased effectiveness of the remedy. The selected remedy for contaminated soil in
the Old Neutralization Pond is excavation and bioremediation with capping. This remedy
is more costly than the no action or capping alternatives but less costly than the -
excavation/off-site disposal alternative. The no action and capping alternatives do not meet
ARARs so the higher cost is justifiable. The bioremediation remedy is a permanent remedy
while all the others including excavation/off-site disposal are not. Since the
excavation/bioremediation is less costly than the excavation/off-site disposal, it is a good
value.
10.4 Utilization of Permanent Solutions to the Maximum Extent Practicable
EPA and ADEM believe that the remedy selected is the most appropriate cleanup solution
for OU2 of the Stauffer Chem (Cold Creek Plant) Superfund Site and provides the best
balance among the evaluation criteria for the remedial alternatives considered. The selected
remedy for the Old Neutralization Pond is a permanent remedy for the top 16 feet of
contaminated soil and treated soil can be returned to the Site. As mention previously a
small percentage of contaminated soil above the cleanup level will be left due to the
extreme engineering difficulty and low cost-benefit of removing that soil. It is not expected
that this small percentage will significantly contribute to groundwater contamination. The
selected remedy for the Old Neutralization Pond meets the statutory requirement to utilize
permanent solutions to the maximum extent practicable.
10.5 Preference for Treatment as a Principle Element ;
The statutory preference for treatment will be met through the ex-situ bioremediation (land
treatment) of contaminated soil in the Old Neutralization Pond.
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES
No significant changes have been made from the proposed plan.
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RECORD OF DECISION
APPENDIX A
RESPONSIVENESS SUMMARY
STAUFFER CHEM (COLD CREEK PLANT) SUPERFUND SITE
SOURCE OPERABLE UNIT 2 (OU2)
MOBILE COUNTY, ALABAMA
35
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Responsiveness Summary
Stauffer Chem (Cold Creek Plant) Superfund Site
Source Operable Unit 2 (OU2)
Mobile County, Alabama
The U.S. Environmental Protection Agency (EPA) held a public comment period from
April 10, 1995 through May 9,1995 for interested parties to give input on EPA's
Proposed Plan for Remedial Action at Operable Unit 2 (OU2) of the Stauffer Chem
(Cold Creek Plant) Superfund Site in, Mobile County, Alabama. EPA conducted a
public meeting on April 18,1995, at the Elf Atochem Conference Center in Axis,
Alabama. The meeting presented the results of the Remedial Investigation and
Feasibility Study (RI/FS) for OU2 of the Stauffer Chem (Cold Creek Plant) Site and
the Proposed Plan of action for remediation.
A responsiveness summary is required to document how EPA addressed citizen
comments and concerns about the Site, as raised during the public comment period.
All comments summarized in this document have been factored into the final
decision of the remedial action for OU2 of the Stauffer Chem (Cold Creek Plant) Site.
This responsiveness summary for the Stauffer Chem (Cold Creek Plant) Site is
divided into the following sections.
I. Overview - This section discusses the recommended alternative for
remedial action and the public reaction to this alternative.
r'
II. Background on Community Involvement and Concerns: This section
provides a brief history of community interest and concerns regarding
the Stauffer Chem (Cold Creek Plant) Site.
III. Summary of Major Questions and Comments Received During the
Public Comment Period and EPA's Responses: This section presents
comments submitted during the public comment period and provides
the responses to these comments.
IV. Concerns to be Addressed in the Future: This section discusses
community concerns of which EPA should be aware during remedial
design.
I. Overview
The remedial alternatives were presented to the public in a Proposed Plan released
on April 10, 1995, and in a public notice in the Mobile Press Register on April 10,
A-l
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and April 15, 1995. A public meeting was held on April 18,1995, where
representatives from EPA answered questions regarding the Site and the proposed
plan under consideration.
EPA has organized the work at this Site into three phases or operable units (OUs).
This operable unit is the second of three at the Stauffer Site. Operable unit one
addressed groundwater contamination and was enumerated by a ROD that was
signed by EPA on September 27,1989. Operable unit three (OU3) addressed the
contamination of Cold Creek Swamp; a ROD was signed September 17,1993.
Operable unit two (OU2), which is enumerated by this Record of Decision, addresses
contamination of the source areas at the Site.
For the Cold Creek LeCreek Wastewater Treatment Pond, the selected remedy is no
further action. For the Cold Creek North Landfill and Cold Creek South Landfill, the
selected remedy is cap maintenance with continued groundwater monitoring. The
estimated cost is $174,500.
4.
For the contaminated soil of the Old Neutralization Pond the selected remedy
consists of bioremediation of contaminated soil, backfilling, and capping the pond.
Major components are as follows:
• Perform a treatability study to determine the design and operational
parameters for the ex-situ land treatment of contaminated soils.
• Setup of the treatment pad.
/
• Excavate contaminated soil and place it in the treatment cell.
• Periodically fertilize, irrigate, and till the soils until they have reached
the target concentration, based on sampling data.
• Backfill excavated areas with clean and treated soil.
• Construct a cap equivalent to a RCRA Subtitle C cap.
• Conduct groundwater monitoring for 30 years.
• Maintain the integrity of the cap.
The cost of this remedy would be $927,900. The total estimated cost would be
$1,102,400.
The community had very few concerns related to the proposed remedy. Most agreed
with the proposed plan and thought it was the best solution.
A-2
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II. Background on Community Involvement and Concerns
EPA has taken the following actions to insure that interested parties have been kept
informed and given an opportunity to provide input on activities at the Stauffer
Chem (Cold Creek Plant) Superfund Site. The Satsuma Public Library on Old
Highway 43, Satsuma, Alabama, was chosen as the local information repository for
the Site. The public comment period on the proposed plan preceding this ROD
(OU2) was held April 10 - May 9, 1995. A public meeting was held on April 18,
1995, where representatives from EPA answered questions regarding the Site and the
proposed plan under consideration. Approximately 25 people attended the meeting.
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 April 10, and April 15,
1995. -
4
This decision document presents the selected remedial action for OU2 of the Stauffer
Chem (Cold Creek Plant) Superfund Site, chosen in accordance with CERCLA, as
amended by SARA and to the extent practicable, the NCP. The decision for this Site
is based on the administrative record. The requirements under Section 117 of
CERCLA/SARA for public and state participation have been met for this operable
unit.
III. Summary of Major Questions and Comments Received During the Public
Comment Period and EPA's responses
Comment 1: Two commentors supported EPA proposed remedy. One went on to
state that the bioremediation treatment selected for the Old Neutralization Pond is
both effective and reasonably cost effective. This commenter preferred the treatment
alternative over simply capping the Old Neutralization Pond.
Response 1: EPA agrees that the treatment alternative meets the nine criteria of the
NCP along with being effective treatment and cost effective.
Comment 2: One commentor felt it was not a good practice to propose or select a
remedy that caps waste in place.
Response 2: Although a small amount of contaminated soil above the cleanup
standard will be left below 16 feet in the Old Neutralization Pond, it is expected that
this will be less than 10% of the total amount delineated. This is due to the extreme
engineering difficulty and low cost-benefit of removing that soil. Excavation below
16 feet would require sheet piling to shore the sides since this pond is adjacent to the
A-3
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Cold Creek LeCreek Wastewater Treatment Pond and the South Landfill. Since a
groundwater pump and treat system has been in place since the 1980's, any residual
contamination will be captured by the in-place groundwater remediation system. It
is not expected that this small percentage will significantly contribute to groundwater
contamination. EPA believes that the selected remedy is protective of human health
and the environment and satisfies the nine criteria in the NCP. Hence, the
biotreatment and capping options is the best alternative.
Comment 3: The PRP was concerned that the proposed plan only delineated one
location for the biotreatment pad when the FS suggested two treatment pad locations.
Response 3: The final ROD delineates both treatment pads that were suggested in
the ROD. This error was also clarified in the April 18, 1995 public meeting. Both
locations were identified in the public meeting as acceptable treatment pad locations.
Comment 4: The PRP commented that Alternative #4 does not clearly state that the
portion of the soil excavated from the Old Neutralization Pond that is shown to be
clean will be set aside for backfill. The LH indicates that the soil is clean to a depth
of 5 to 8 feet within the original pond perimeter.
Response 4: The ROD clearly states that the backfill material will be either treated or
dean soil. As long as the material set aside is clean or below performance standards
it can be used as backfill for the pond.
IV. Concerns to be Addressed in the Future
;
The community had very few concerns related to proposed remedy. Most agreed
with the proposed plan and thought it was the best solution.
A-4
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RECORD OF DECISION
APPENDIX B
CONCURRENCE LETTER
STAUFFER CHEM (COLD CREEK PLANT) SUPERFUND SITE
SOURCE OPERABLE UNIT 2 (OU2)
MOBILE COUNTY, ALABAMA
36
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SOUTH
W C I *./ 1^ $>f to I C r<
ALABAMA b! nr<
DEPARTMENT OF ENVIRONMENj]^
'-•^C
Y^
W'
n M. Smith, Director June 15, 1995
iling Address:
BOX 301463
3NTGOMERYAL
130-1463
AL
Fob James. Jr.
Governor
lysical Address:
'S1Cong.W.L
! idkinson Drive
lontgomery. At
6109-2608
334)271-7700
AX 270-5612
Field Offices:
110 Vulcan Road
Birmingham, AL
35209-4702
(205)942-6168
FAX 941-1603
400 Well Street, NE
P.O. Box 953
Oecatur.AL
35602-0953
(205)353-1713
FAX 340-9359
2204 Perimeter Road
Mobile. AL
36615-1131
(334)450-3400
"FAX 479-2593
Ms. Joanne Benante
Remedial Project Manager
South Superfund Remedial Branch
US Environmental Protection Agency
345 Courtland Street, NE
Atlanta, GA 30365
Re: Draft Record of Decision
Operable Unit 2
StaufFer Chemical Company
Cold Creek Superfund Site
Dear Ms. Benante:
The Department has reviewed the referenced document. Based on our review, we concur
with the Draft Record of Decision without further comment.
Please contact Mr. C.H. Cox at 334-260-2785 if you have questions or comments regarding
this matter.
Sincerely,
-j-Jphn M. Smi
""^ yr>iror-t
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