r\ pn/V Explanation of Significant Differences
Vytin South Carolina Recycling and Disposal, Inc. Dixiana
EiwifofwuftuiPrwurtwn Superfund Site
A$oiH
West Columbia, SC
I. Introduction
This decision document presents an Explanation of
Significant Differences (ESD) for the South
Carolina Recycling and Disposal, inc. (SCRD1)
Dixiana Superfund Site (Site), located in West
Columbia, South Carolina. The Record of Decision
(ROD) dated September 26, 1986 and the ESD
dated July I. 1993 are addressed by this ESD.
The ESD is issued in accordance with § 117(c) of
the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980
(CERCLA), 42 LLS.C. § 9601 et scq., as amended
by the Superfund Amendments and Reauthorization
Act of 1986 (SARA), and the National Oil and
Hazardous Substances Pollution Contingency Plan
(NCP). § 300.435(cX2K>)- The Director of the
Superfund Division has been delegated the authority
to sign this document.
This ESD wilt become part of the Administrative
Record for the SCRD3 Dixiana Superfund Site
(NCP 3Q0.825(aX2)). which has been developed in
accordance with § 113 (k) of CERCLA. 42 U.S.C. §
9613 (k).
Ihe Administrative Record is available for review
at the Lexington County Public Library. Caycc-
West Columbia Branch, located at 1500 Augusta
Road in West Columbia. South Carolina, and at the
U.S, EPA Region 4 Office, 61 Forsyth Street SW,
Atlanta, Georgia 30303.
II. Statement of Purpose
Since the ROD and ESD finalization dates, issues
concerning institutional controls (land use
restrictions) have been identified at the Site. The
purpose of Ihis ESD is to modify the final remedy
decision to include institutional controls.
EPA prepares an ESD when it is determined by the
Agency that changes Co the original selected remedy
are significant, but do not fundamentally alter the
remedy selected in the ROD with respect to scope,
performance, or cosL
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Ill Site History and Contamination
Site Htstory
The Site is located in West Columbia, Lexington
County, South Carolina and occupies two acres
(Figure t). The Site includes the SCRDI Dixiana
Properly, where the groundwater extraction and
treatment system and a privately owned warehouse
are located (Figure 2). Two residential properties
Eire located to the east of the Site, Primary access to
the Site is from Ballard Court, which borders the
northern portion of the Site, while the remainder of
the area surrounding the Site is being developed for
commercial land uses.
In summer 1978, SCRD1 began storing drummed
industrial wastes at the Site. By late 1978,
approximately 1,100 drums; of waste material,
including paints, solvents, phenols, acids, oils and
dves were stored on the SCRDI Dixiana Property.
Frequent discharges from the drums into the
environment occurred because of poor drum
handling practices, leaky drums and the exposure of
drums to weather. In 197S. SCRDI filed for a waste
management permit from the South Carolina
Department of Health and Environmental Control
(SCDHEC), which denied the permit request
because of SCR 1) I s poor waste management
practices. Later in 1978, SCDHEC filed suit against
SCRDI. banning further shipments of waste to the
Site and implementing a waste inventory and
cleanup program. To address contamination at the
Site, SCRDI removed surficial waste drums and
visibly contaminated soils between September 1978
and June 1980.
Results of investigations conducted by SCDHEC,
showed volatile organic compounds (VOCs) were
found in the groundwater and visibly contaminated
soil containing high levels of metals and VOCs
were located throughout the Site. Subsequently.
SCRDI removed all drummed wastes and visibly
contaminated surface soil was stockpiled for later
disposal. SCDHEC also informed the owners of the
residential wells located adjacent to the Site of the
contamination and advised them to seek an alter-
native drinking water supply. The nearby residents
now utilize municipal water from the City of Cayce.
Due to the presence of groundwater contamination,
the EPA listed the Site on its National Priorities List
(NPL) in September 1983. To determine the extent
of contamination. EPA conducted a remedial
investigation feasibility study
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(December 2009) indicate two (1.1 -Dichloroethcne
and Tetrachlorocthene) of the twenty COCs are
above clean-up criteria and the groundwater cleanup
goals have been achieved at most areas of the Site.
The highest concentration of 1,1-Dichloroethenc
was detected on-site at a concentration of 23 ug 1.,
exceeding the cleanup goal of 7 ugL. The highest
concentration of Tetrachloroethene was detected
on-site at a concentration of 360 ug'L. exceeding
the cleanup goal of 5 ug'L,
IV. Selected Remedy
The results of the R1 FS and the BRA indicated
ingestion of contaminated groundwater posed an
unacceptable risk to human health. Soil, surface
water, and'or sediment did not pose a risk to human
health or the environment, Therefore, EPA issued a
ROD on September 26. 1986, which selected a
groundwater extraction and treatment system as the
remedy for groundwater contamination.
Specifically, the selected remedy in the ROD
included:
» Extraction of groundwater using deep well
technology,
• Treatment of groundwater using an on-site
water treatment system.
• Discharge of treated groundwater to surface
watts'.
Construction of the selected remedy began in
October 1990; how ever. EPA issued an ESD in July
1991 to change the remedial components of the
selected remedy. The ESD selected more cost-
effective components for the groundwater
extraction and treatment system, including the use
of a pyrolox metal media filter system instead of a
clarificr and greensand filters, and changed
the discharge point for treated groundwater into the
City of Cayce's Publicly Owned Treatment Works
{POTW) instead of into surface water. The Remedy
did not include institutional controls restriction on
access and use of groundwater beneath the Site.
The construction of the remedy was completed in
September 1992. Since 1992. EPA conducted three
Five-Year Reviews (FYRs} of the remedy to
determine if the remedy remained protective of
human health and the environment. The results of
each of the FYRs indicated the remedy was
protective and was. functioning as designed. While
the groundwater extraction and treatment system
was performing as designed, additional
modifications were made to improve the overall
effectiveness of the treatment system and better
control off-site migration of the groundwater plume.
All work conducted to enhance the groundwater
extraction and treatment system was performed by
the potentially responsible parties fPRPs). The
PRPs, under EPA oversight, are also performing
long-term monitoring and operation and
maintenance of the groundwater extraction and
treatment system. Over 135 million gallons of
groundwater have been extracted, treated, and
discharged to the POTW.
As noted, a significant portion of the Site property
is undergoing commercial development. The si/.e
of the groundwater plume has been reduced as a
result of continual groundwater treatment, and
several groundwater monitoring wells have been
abandoned in the area being developed. As the
groundwater plume continues to decrease in size,
EPA is likely to abandon additional monitoring
wells. To avoid influencing the groundwater plume
that remains at the Site, restrictions on access and
use of the groundwater have been placed on these
properties.
V. Description of Significant
Differences and Basis for the ESD
Institutional controls are being implemented at the
Site because, while the remedial action is being
implemented, hazardous substances, pollutants, or
contaminants remain at the Site above levels that
allow for unlimited use and unrestricted exposure to
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groundwater. The remedial action provided in the
ROD does not include restrictions oil access and use
of groundwats at the Site, while the remedy is
being implemented As a result, this ESD is needed
to document the implementation of institutional!
controls as part of the groundwater remedy.
VI. Support Agency Comments
In accordance with the NCP §300 435(c)(2). EPA
consulted with the SCDHEC prior to the issuance of
this ESD EPA also provided SCDHEC with the
oppommity I© comment on the draft ESD
SCDHEC supports the issuance of this ESD and
provided comments on an earlier draft Their
comments have been incorporated into this version.
VIII. Public Participation
The public participation requirements set out in the
NCP § 30Q.435(cX2} will hs met by publishing this
ESD, making it available to the public in the
Administrative Record, and publishing a notice
summarizing the ESD in a major local newspaper.
IX. Authorizing Signature
I have determined the remedy for the Sue, as
modified by this ESD, is protective of human health
and the environment, and will remain so provided
the actions presented in this report are implemented
as described above.
VII. Statutory Determinations
EPA has determined that these significant changes
comply with the statutory requirements of CERCLA
§ 121, 42 U.S.C. § 9621, are protective of human
health and the environment, comply with Federal
and State requirements that arc 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
Because this remedy upon completion, will not
leave hazardous substances, pollutants, or
contaminants on site above levels thai allow for
unlimited use and unrestricted exposure, but
requires five years or more to complete, a policy
review will be conducted no less often than each
five years after the initiation of the remedial action
to ensure that the remedy is, or will be, protective of
human health and the environment. The first FYR
was completed on Septsnber 29, 1995, The second
FYR was completed on September 28, 2000, The
third FYR was completed on September 27, 2005.
FYRs will continue until cleanup goals have been
attained.
Protection Agency
Director
Superfund Division
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LIST OF ABBREVIATIONS
BRA
Baseline Risk Assessment
CERCLA
Comprehensive Environmental Response, Compensation, and Liability Act of 1980
CFR
Code of Federal Regulations
COCs
Contaminants of Coneern
EPA
United Stales Environmental Protection Agency
ESD
Explanation of Significant Differences
FYR
Five-Year Review
GWETS
Groundwater Extraction and Treatment System
NCP
National Oil and Hazardous Substances Pollution Contingency Plan
NPL
National Priorities List
POTW
Publieally Owned Treatment Works
PRPs
Potentially Responsible Parties
RITS
Remedial Investigation Feasibility Study
ROD
Record of Decision
SARA
Superfund Amendments and Reauthorization Act of 1986
SCDHEC
South Carolina Department of Health and Environmental Control
SCRD1
South Carolina Recycling and Disposal. Inc.
Sile
South Carolina Recycling and Disposal, Inc. Dixiana Superfund Site
U.S.C
United States Code
VOC
Volatile Organic Compounds
H&'L
micrograms per liter
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