Explanation of Significant Differences
united states Woolfolk Chemical Works
Environmental Protection
Superfund Site
Site Name: Woolfolk Chemical Works Superfund Site
CERCLA ID #: GAD003269578
Site Location: 311 Martin Luther King Jr. Drive,
Fort Valley, GA 31030
Lead Agency: EPA, Region 4
Support Agency: Georgia Environmental Protection Division
Fort Valley, Georgia
I. Introduction
This Explanation of Significant Differences (ESD)
documents significant changes to the remedy
selected for Operable Unit (OU) #3 at the Woolfolk
Chemical Works Superfund Site ("Woolfolk Site"
or "Site"). The cleanup remedy is being modified
to address the unanticipated increase in volume of
contaminated soil and the increase in arsenic
concentrations found at the Site, while continuing to
protect human health and the environment.
Unanticipated volumes and concentrations of
contaminants at the Site require additional
excavation, treatment, and disposal of soil, debris,
and other materials to ensure the remedy is
protective and to remove the source of continued
ground water contamination.
Section 117(c) of the Comprehensive
Environmental Response, Compensation, and
Liability Act (CERCLA), as amended by the
Superfund Amendments and Reauthorization Act
(SARA), and Section 300.435(c)(2)(i) of the
National Oil and Hazardous Substances Pollution
Contingency Plan (NCP) require that the United
States Environmental Protection Agency (EPA)
publish an ESD when significant changes in a
Superfund remedy occur after the Record of
Decision (ROD) has been signed.
The Administrative Record contains the information
upon which the remedy selection was based,
including the ROD, the Amended ROD (AROD) for
OU #3, and the Responsiveness Summary. This
ESD and copies of all documents that formed the
basis for modifying the remedy will become part of
the Administrative Record, in accordance with 40
Code of Federal Regulations (CFR) Section
300.825(a)(2) and 40 CFR Section
300.435(c)(2)(i)(A) of the NCP and CERCLA
Section 117(d).
The Administrative Record is available for review
at the Thomas Public Library, 315 MLK Jr. Drive,
Fort Valley, GA 31030. The Thomas Public
Library is open at the following times:
Monday: 10:00 a.m. - 8:00 p.m.
Tuesday - Thursday: 10:00 a.m. - 6:00 p.m.
Saturday: 10:00 a.m. - 4:00 p.m.
The Administrative Record is also available for
review at U.S. EPA Region 4, 11th Floor Records
Center, 61 Forsyth Street SW, Atlanta, Georgia
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30303. The U.S. EPA Region 4 Records Center is
open at the following times:
Monday - Friday: 7:30 a.m. to 4:30 p.m.
Specific questions about the Woolfolk Site can be
directed to: Charles King, Remedial Project
Manager. Tel. (404) 562-8931.
II. Statement of Purpose
The purpose of this ESD is to document that the
U.S. EPA, as the lead agency, with the involvement
of the Georgia Environmental Protection Division
(GAEPD), is enacting significant changes to the
remedy for OU #3. In addition, this ESD also
provides the rationale and explains the basis for
these changes. The significant changes include:
increasing the volume of contaminated soil
to be excavated and treated;
modifying soil treatment levels; and
modifying methods of disposal for
contaminated soil.
This ESD modifies the remedy selected in the ROD
for OU #3, signed August 6, 1998, and the AROD
for OU #3, signed August 30, 2004.
This ESD for the Woolfolk Site was prepared by
EPA's Region 4 office in Atlanta, Georgia, in
coordination with GAEPD. The components of the
remedy for OU #3 of the Woolfolk Site, as revised
through this ESD, are in compliance with the
requirements of CERCLA, as amended by SARA,
and with the NCP. The remedy, as revised through
this ESD, is protective of human health and the .
environment, complies with federal and state
requirements that are legally applicable or relevant
and appropriate, and is cost-effective. This revised
remedy decision is based on the Administrative
Record for the Site. A detailed explanation of the
basis for these modifications is presented further in
this document.
III. Site History and Contamination
The 31-acre Woolfolk Site is located in Fort Valley,
Peach County, Georgia. Eighteen of the 31 acres,
designated as OU #3, include a former pesticide
production, formulation, and packaging facility and
an unlined disposal pit. The facility operated from
1910 until the 1980s. The primary contaminants
associated with this site are:
arsenic;
lead;
dichlorodiphenyl trichloroethane (DDT);
dichlorodiphenyldichloroethene (DDE);
dichlorodiphenyldichloroethane (DDD);
lindane; and
other pesticides and herbicides.
Concerns regarding environmental degradation at
the Site began in the early 1980s, when GAEPD
responded to complaints from local citizens and
discovered facility discharges into a drainage
corridor heading away from the Site. Several years
later, the facility owner, Canadyne-Georgia
Corporation (CGC), capped a disposal pit at the Site
and sold portions of the facility. As part of that
sale, a removal action was conducted by CGC to
remediate the production facility and the
surrounding soils. Data from the removal action
indicated extensive contamination at the Site. The
Site was placed onto the National Priorities List in
August 1990, and CGC entered into an agreement
to study the Site through performance of a Remedial
Investigation and Feasibility Study (RI/FS). The
RI/FS indicated that the greatest risk at the Site
resulted from arsenic contamination.
Upon determination that the drainage corridor, the
initial source of concern at the Site, was
significantly contaminated with arsenic and
pesticides, CGC was issued a federal order to
complete a removal action within approximately
one-half mile of the most affected areas of the
corridor. That action resulted in the removal and
disposal of 26,000 tons of arsenic-contaminated
soils and debris. Under the order, CGC also
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completed the demolition of a dioxin-contaminated
pesticide packaging building that yielded
approximately 45 cubic yards of demolition debris,
which were shipped off site for incineration. In
addition, house dust in eight homes was found to
have excessive arsenic levels. The cleanup and
monitoring of those homes was completed in June
1998.
In March 1994, EPA issued an OU #1 ROD,
selecting a remedy for the Site's ground water
contamination. Installation of the ground water
pump and treat system was completed in 1998. The
pump and treat system is currently operational and
functional. Based on results from ground water
sampling activities, it has been demonstrated that
contamination from the soils at the former
manufacturing facility has leached into the ground
water aquifers. Based on the most recent data,
small concentrations of the contaminated plume
have extended beyond the most downgradient well.
EPA is in the process of conducting a pump test to
determine the appropriate locations for additional
extraction wells, which will help to optimize the
efficiency of the current system.
EPA issued a ROD for OU #2 at the Site in
September 1995. The remedy provided for removal
of contamination and CGC's purchase and
conversion of approximately 17 residential
properties into commercial use. The ROD
documented the proposed reuse of these properties
as a public library, an adult education center, a
Welcome Center for the City, and administrative
offices for the local agencies.
On August 6, 1998, EPA signed the OU #3 ROD
for the Site. The remedy outlined in the OU #3
ROD addressed contaminated soils and buildings on
the former Woolfolk facility property, the capped
area containing materials consolidated by the
former site operators, and the stormwater drainage
system both on- and off-site.
The principal threat waste addressed under the ROD
for OU #3 was the large volume of contaminated
surface and subsurface soil at the former
manufacturing facility, which presented a
significant threat to human health and the
environment. The contaminated surface soil at the
former facility posed a potential significant threat,
via the dermal contact and inhalation routes. The
contaminated subsurface soils were a principal
threat to the ground water aquifers beneath and
hydraulically downgradient from the Site.
The 1998 OU #3 ROD estimated that approximately
8,000 cubic yards of contaminated soil and
materials would be excavated from the capped area
for off-site disposal. Subsequent data from the
capped area collected during the Remedial Design
indicated that approximately 40,000 cubic yards of
material exceeded the cleanup levels identified in
the ROD. In addition, in January 2001, the federal
ground water Maximum Contaminant Level (MCL)
for arsenic was changed. Based on the increased
amount of contaminated soil identified and the
change to the arsenic MCL, EPA signed an AROD
for OU #3 on August 30, 2004. In addition to
addressing the greater risk resulting from the
increase in volume of contaminated material found
at the Site, the AROD also established a more
protective cleanup standard for arsenic-
contaminated subsurface soils at the Site consistent
with the January 2001 arsenic MCL reduction. The
AROD also reduced the subsurface soil remediation
level for arsenic from 113 parts per million (ppm) to
20 ppm in unpaved areas of the Site that would be
available for unrestricted future use. The AROD
estimated that excavation to an average depth of 15
feet (ranging from 4 to 24 feet) would be sufficient
to achieve the soil cleanup level of 317 ppm arsenic
for the areas that would be paved and subject to
land use restrictions. It stated that any additional
excavation necessary to achieve 317 ppm would be
conducted to the extent practicable.
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IV. Selected Remedy
The major components of the Woolfolk OU #3
ROD signed in 1998 included:
excavation of estimated 8,000 cubic yards of
contaminated soils and materials from capped
area;
on-site solidification/stabilization (S/S) of
contaminated soils and materials;
off-site disposal of contaminated soil and
material with arsenic concentrations greater than
317 ppm for paved areas;
consolidation of and paving with
asphalt/concrete over soils with greater than 113
ppm arsenic;
institutional controls to prevent residential use,
restrict land and ground water use, and require
pavement maintenance;
demolition of contaminated buildings of limited
use and disposal in off-site landfill;
decontamination, where possible, of
contaminated buildings suitable for future uses;
and
identification and repair of deteriorated sections
of the stormwater sewer system, removal of
sediment (through jetting and vacuum
equipment), and disposal of sediment with on-
site soils.
The remedial action objectives for the 1998 OU #3
ROD included:
prevent ingestion, inhalation, or direct contact
with surface soil that contains concentrations in
excess of remediation levels;
control migration and leaching of contaminants
in surface soil to ground water that could result
in ground water contamination in excess of
MCLs or health-based levels;
prevent ingestion or inhalation of soil
particulates in air that contain concentrations in
excess of remediation levels;
permanently and/or significantly reduce
toxicity/mobility/volume (T/M/V) of
characteristic hazardous waste by treatment; and
control future releases of contaminants to ensure
protection of human health and the
environment.
The estimated cost was $9.5 million.
The AROD signed in 2004 only included changes to
the remedies for the soils and cap. Changes
included the following:
consolidation and paving with asphalt/concrete
over soil with concentrations greater than 20
ppm arsenic; and
increased excavation estimate to approximately
120,000 cubic yards of contaminated soil.
The remedial action objectives identified in the
2004 AROD were unchanged.
The estimated cost was approximately $16 million.
V. Basis for the ESD
As the Remedial Action activities at OU #3
progressed, it became clear that the volume of soils
contaminated at levels exceeding 317 ppm in OU #3
was significantly greater than estimated. Although
the historical site information and documents
generated by EPA during the Remedial Design
process indicated that the Capped Area would be
the primary focus for subsurface excavation and
that the maximum concentration of arsenic in the
Capped Area would not exceed 10,000 ppm, data
from the Remedial Action field activities indicated
the presence of arsenic in the range of 20,000 to
250,000 ppm in the Capped Area (Figure 1).
Additional arsenic contamination was also
identified in the adjacent Area C-l, with
concentrations as high as 710,000 ppm, the highest
arsenic concentration encountered at the Woolfolk
Site to date.
The 2004 AROD estimated an excavation depth
range of 4 to 24 feet, with an average of 15 feet, to
either achieve the cleanup goals or encounter
ground water at the Site. However, the excavations
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continued, without encountering ground water, to
approximately 40 feet in several areas before
cleanup goals were met. Terminating the
excavation activities at an average depth of just 15
feet would have left more than 20 feet of soil with
significant arsenic concentrations above 317 ppm in
place at the Site.
Although the AROD estimated that a volume of
120,000 cubic yards of contaminated soil would be
excavated from OU #3, approximately 500,000
cubic yards of contaminated soil have been
excavated from OU #3 to date. The discovery of
additional contaminated soil within the Capped
Area and in the adjacent Area C-l required the
construction of an additional containment cell,
located in Area C-l (Figure 1), as well as a
significant increase in disposal expenditures.
The table below shows the approximate dimensions,
contained soil volume, and arsenic concentrations
for the three containment areas within OU #3.
Table 1. OU #3 Containment Area Summary
Containment Area
Approximate Dimensions
Arsenic Concentration
Capped Area
240 feet x 130 feet / 0.36 acres
317 - 3,000 ppm / TCLP results less
than 2.5 mg/L
C-l
Approximately 300 feet x 300
feet/ 1.97 acres
317 - 3,000 ppm / TCLP results less
than 2.5 mg/L
C-2
180 feet x 305 feet / 1.26 acres
317 ppm (arsenic soils excavated from
OU #4 residential areas)
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During the remediation activities, it was discovered
that some of the contaminated soils with arsenic
concentrations above 317 ppm could be cost-
effectively treated to meet leachate testing
requirements established in the Toxicity
Characteristic Leaching Procedure (TCLP) for
Subtitle D Landfill disposal. Since TCLP arsenic
limits for Subtitle D Landfill disposal are defined as
5 milligrams per liter (mg/L), EPA concluded that
batches of treated soil with initial arsenic
concentrations of less than 3,000 ppm and arsenic
TCLP results of less than 2.5 mg/L, (1/2 the TCLP
limit for arsenic), could be placed in on-site
containment cells with high-density polyethylene
(HDPE) liners. Section 7.1.7 of the 1998 ROD
designated a Corrective Action Management Unit
(CAMU) to facilitate the handling and processing of
the contaminated soil on-site. The transport,
treatment, and storage of the contaminated soil in
the CAMU during a remedial action does not
require compliance with land disposal restrictions or
other requirements of the Resource Conservation
and Recovery Act (RCRA) (See 40 CFR Part
264.552). Disposal in an on-site HDPE-lined cell
was determined to be more cost-effective than
transporting, treating, and storing contaminated soil
off site. Pavement and institutional controls would
still be implemented in all of the consolidation
areas, as required in the OU #3 AROD.
As a result, batches of arsenic-contaminated soils
were solidified and stabilized using a combination
of portland cement, lime kiln dust, and ferric or
ferrous granules or powder. A representative
sample was collected from each batch of treated
material and a full scan TCLP analysis was
performed by the Contract Laboratory Program
(CLP) lab. The results from the TCLP analysis
were used to determine when on-site disposal was
possible and when off-site disposal in a Subtitle C
Landfill was required.
The capacity for containment of OU #3 arsenic-
contaminated soils in HDPE-lined cells was limited
to the size of excavations in C-l and the Capped
Area (Area C-2 was used to contain the untreated
residential soil from OU #4 remediation activities
that contained concentrations less than 317 ppm
arsenic, in accordance with the ROD for OU #4 and
the AROD for OU #3). Since a large volume of
material that met TCLP standards would still have
to be transported off site to an approved Subtitle D
Landfill because of the limited capacity of the
HDPE liners within Area C-l and the Capped Area,
a decision was made to place batches of the treated
material with the lowest initial arsenic
concentrations and lowest TCLP results in the on-
site liners. As a result, batches of treated soil with
initial arsenic concentrations of less than 3,000 ppm
and arsenic TCLP results of less than 2.5 mg/L were
placed in the on-site HDPE liners until capacity was
reached. Once on-site capacity limits were reached,
the additional treated soils with arsenic
concentrations of less than 3,000 ppm and arsenic
TCLP results of less than 2.5 mg/L were transported
off site to an appropriate Subtitle D Landfill for
disposal. When the TCLP standards could not be
met, the material was disposed of as hazardous
waste in an approved Subtitle C Landfill off site.
This disposal scheme continues to be followed.
Excavation, HDPE liner installation, and backfilling
are complete in the three consolidation areas, Area
C-l, Area C-2, and the Capped Area. It is
anticipated that shallow excavation (approximately
2 to 4 feet) will be required to achieve cleanup goals
in the remaining four to five acres at OU #3.
The unanticipated increase in volume of highly-
contaminated soil that required disposal in Subtitle
D and Subtitle C Landfills has increased remedial
costs at the Site when compared to the estimate
provided in the 2004 AROD.
The Applicable or Relevant and Appropriate
Requirements (ARARs) previously identified for
OU #3 remain the same.
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WHKSVVs. V
Ms
Key
Q OU #3 Boundary
HDPE-Lined
¦ m J Disposal Areas
i8o' Disposal Area
Dimensions
| Existing Buildings
OU #3 Subareas
H °~1
Capped Area
mm c-2
Remaining
Excavation Area
Jacob's Alley
| Not* AU»jnd
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VI. Description of Significant
Differences
Differences between the 2004 AROD and the
current ESD are outlined below.
In the 2004 AROD, soil contaminated with
arsenic above 317 ppm required off-site
disposal. As indicated in this ESD, the TCLP
results were used to determine when off-site
disposal was required. Treated soil with initial
arsenic concentrations of less than 3,000 ppm
and arsenic TCLP results of less than 2.5 mg/1
was placed in the on-site HDPE liners until
capacity was reached. After capacity was
reached, the treated soil meeting those
requirements was disposed of off site in a
Subtitle D Landfill. If TCLP standards could
not be met, the material was disposed as
hazardous waste in an approved Subtitle C
Landfill.
This ESD documents the increase in the amount
of contaminated soil that was excavated,
evaluated, and, if necessary, treated and
properly disposed of, from 120,000 cubic yards
to more than 500,000 cubic yards.
This ESD documents the increase in the
estimated cost of the remedy, from
approximately $16 million to approximately $26
million.
The AROD estimated an excavation range of 4
to 24 feet to either achieve cleanup goals or
encounter ground water at the Site. This ESD
documents that excavation continued to
approximately 40 feet in several areas, without
encountering ground water, before a cleanup
goal of 317 ppm was achieved.
The 2004 AROD anticipated that HDPE-lined
containment cells would be constructed in the
Capped Area and in Area C-2. This ESD
documents that HDPE-lined containment cells
were constructed in Area C-l, Area C-2, and the
Capped Area. As a result, the acreage requiring
pavement and institutional controls has
increased from approximately four acres to six
acres.
The excavation and treatment of approximately 20
additional feet of contaminated soil in two of the
consolidation areas (the Capped Area and Area C-l)
will result in an even greater reduction in the threat
to human health and the environment than would
have been achieved by implementing the AROD.
The remedy continues to require pavement over any
area with an arsenic concentration greater than 20
ppm, including the Restricted Future Use Area
illustrated in Figure 2, where institutional controls
are required to limit residential land uses,
excavation, and ground water use. EPA will require
all owners of properties that constitute OU #3 to
implement land use and ground water use
restrictions through restrictive covenants which may
be enforced by GAEPD, EPA, or another third party
beneficiary. In addition, owners will be required to
put notice of such use restrictions in their recorded
deeds.
The overall scope of the remedy conducted under
this ESD remains the same as in the AROD. The
significant change in the remedy is the "trigger" that
is being used to determine when off-site disposal is
required. In the 2004 AROD, soil contaminated
with arsenic above 317 ppm required off-site
disposal. Soil contaminated with arsenic at
concentrations between 20 ppm and 316 ppm could
be placed in the consolidation areas under
pavement. In this ESD, the results from the TCLP
analysis were used to determine when off-site
disposal was required.
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Table 2. Summary of Significant Changes
Remedy Components
2004 Amended Remedy
Revisions in this ESD
Difference
Volume of contaminated
soil for excavation
120,000 cubic yards
500,000 cubic yards
380,000 cubic yards
Depth of excavation
4 to 24 feet
Approximately 40 feet or
until cleanup levels are
met
15 feet
Estimated area to be
paved/capped
Approximately 4 acres
Approximately 6 acres
+ 2 acres
Estimated area subject to
institutional controls
Approximately 4 acres
Approximately 6 acres
+ 2 acres
Estimated area without any
restrictions
Approximately 14 acres
Approximately 12 acres
- 2 acres
Soil with arsenic
concentrations >20 ppm
but <317 ppm
On-site
solidification/stabilization
with on-site disposal in
HDPE-lined cells or in a
Subtitle D Landfill
On-site
solidification/stabilization
with on-site disposal in
HDPE-lined cells or in a
Subtitle D Landfill
No change
Soils with arsenic
concentrations above 317
ppm
On-site
solidification/stabilization
with off-site disposal;
Subtitle D Landfill
disposal if TCLP results
<5 mg/L arsenic; Subtitle
C Landfill disposal if
TCLP results >5 mg/L
arsenic
On-site
solidification/stabilization
with on-site disposal and
off-site disposal; Subtitle
C Landfill disposal if
TCLP results >5 mg/L;
Subtitle D Landfill
disposal if TCLP results
>2.5 mg/L but <5 mg/L;
on-site disposal in
HDPE-lined cells if
TCLP results <2.5 mg/L
and arsenic soils <3,000
ppm, until lined cell
capacity is reached
Change in soil
treatment and disposal
plan
Arsenic remediation level
for unrestricted use
<20 ppm
<20 ppm
No change
Estimated Cost
$16 million
$26 million
$10 million
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ile Unit #3
Existing Buildings
>ns are approbate, into
Troutman House
(Welcome Center
& Offices)
¦SEIll
L «j
Marlon
Allen In;
IS
Peach County
Library
weMM
Tire ' . > I
r; 4
dmintstr?"^
Building
Figure 2. OU #3 Restricted Future Use Areas
Woolfolk Chemical Works Superfund Site
Fort Valley, Georgia
September 2009
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VII. Support Agency Comments
EPA consulted with the GAEPD and provided it the
opportunity to comment on this ESD in accordance
with NCP Section 300.435 (c)(2) and Section
300.435 (c)(2)(i) and CERCLA Section 121(f). The
GAEPD has been involved with the development
and review of this ESD.
VIII. Statutory Determinations
EPA has determined that these significant changes
to the remedy selected for OU #3 of the Woolfolk
Site comply with the statutory requirements of
CERCLA Section 121, 42 U.S.C. Section 9621, are
protective of human health and the environment,
comply with federal and state requirements that are
applicable or relevant and appropriate to the
remedial action, are cost-effective, and utilize
permanent solutions and alternative treatment
technologies to the maximum extent practicable.
EPA is meeting the statutory preference for
treatment by excavating and treating approximately
380,000 additional cubic yards of contaminated soil
within OU #3.
This remedy will result in hazardous substances,
pollutants, or contaminants remaining on-site above
levels that allow for unlimited use and unrestricted
exposure. Pursuant to CERCLA Section 121(c), 42
U.S.C. Section 9621(c), a statutory review must be
conducted no less often than each five years after
the initiation of a remedial action to ensure that a
remedy is, or will be, protective of human health
and the environment. Based on the date of the firsf
five-year review conducted at the Site, the second
five-year review is scheduled for completion in the
fall of 2009.
IX. Public Participation
This ESD is being made available to the public in
accordance with the requirements of CERCLA
Section 117 the National Contingency Plan Section
- 300.435(c)(2)(i), and the Community Relations Plan
for the Woolfolk Site. A notice of availability will
be placed in the Macon Telegraph newspaper and
copies of this ESD are available at the Information
Repositories at the Thomas Public Library and the
Region 4 Superfund Records Center. Copies of this
fact sheet also will be distributed to the community
mailing list for the Woolfolk Site.
As required by CERCLA Section 117(d) and
Sections 300.435(c)(2)(i)(A) and 300.825(a)(2) of
the NCP, a copy of this ESD will be added to the
Administrative Record for the Woolfolk Site, along
with copies of the documents that provide a basis
for the ESD. Copies of the Administrative Record
are kept at the Thomas Public Library and the
Region 4 Superfund Records Center, as listed in the
"Administrative Record" section of this fact sheet.
X. Authorizing Signature
1 have determined that the remedy for the Site, as
modified by this ESD, is protective of human health
and the environment, and will remain so provided
the actions presented in this ESD are implemented
as described above.
This ESD documents the significant changes related
to the remedy at the Site. U.S. EPA selected these
changes with the concurrence of GAEPD.
U.S. Environmental Pi
"ion Agency
By:
"Franklin E. Hill
Director
Superfund Division
Date:
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