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Addendum to the Wamcheiii, Inc. Superfund Site
Fifth Five-Year Review Report
September 2020
Prepared by:
U.S. Environmental Protection Agency - Region 4
Atlanta, Georgia
Digitally signed by CAROL
MONELL
Carol J. Moil ell, Director
Superfund & Emergency Management Division
Date
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Region 4
61 Forsyth Street
Atlanta, Georgia 30303-3 104
Addendum to the Fifth Five-Year Review Report for Wamchem, Inc. Superfund Site,
dated September 17, 2019
A Five-Year Review (FYR) addendum is generally completed for remedies where the protectiveness
determination is deferred until further information is obtained. When deferring protectiveness in the
FYR Report, the EPA typically provides a timeframe for when the information will be obtained, and a
protectiveness statement can be made. This document provides progress since the September 2019 FYR
and protectiveness determination for the remedy where the statement was deferred in the
September 2019 FYR.
The Five-Year Review Report ("Report") for the Wamchem, Inc. Superfund Site in Burton,
Beaufort County, South Carolina was signed by Randall Chaffins, Deputy Director of the Superfund &
Emergency Management Division on behalf of Franklin Hill, Director of the Superfund & Emergency
Management Division, EPA Region 4 on September 17, 2019. The protectiveness statement outlined in
the Report was as follows:
Sitewide Protectiveness
A protectiveness determination of the remedy cannot be made at this time until further information
is obtained. Additional information will be obtained by sampling the private well of the residential
property and nearby monitoring wells R/-7A andRI-7B. It is expected that this action will take
approximately one year to complete, at which time a protectiveness determination will be made.
Progress Since the Five-Year Review Completion Date
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The 2019 FYR included: nine issues and recommendations that potentially affect the long-term
protectiveness of the remedy, and one issue and recommendation that affected the overall protectiveness
of the remedy. Specifically, data was not available to evaluate the water quality conditions of the private
well located on the residential property adjacent to the Site property, which resulted in the deferral of
overall protectiveness.
The adjacent property private drinking water well has been identified as drinking water well RI-1 1 in the
1987 Remedial Investigation (RI) Final Report. The well RI-1 1 is located northwest of monitoring wells
RI-7A and RI-7B (Figure 1). The screened intervals for wells RI-7A and RI-7B were constructed within
the lower and upper aquifer zones, respectively. The latest groundwater analytical data collected from
wells RI-1 1, RI-7A and RI-7B was conducted during the 1987 remedial investigation phase. Based on
the available data, well RI-7B had an elevated detection for methylene chloride at a concentration of
3.9 |ig/L. The remainder of the data collected for RI-11, RI-7A and RI-7B were non-detect for Site
contaminant of concerns (COC).
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Monitoring well RI-6 was installed during the RI and is located southeast of R.I-11. The screened
interval for well RI-6 is found in the upper zone, and well RI-6 has been routinely monitored as part of
the existing groundwater monitoring program (most recently sampled in April 2020). Based on recent
groundwater analytical data, the COC concentrations at well RI-6 have been below the established
Record of Decision (ROD) cleanup goals.
Since monitoring well RI-6 is screened within the upper zone of the aquifer, the most recent data does
not confirm groundwater conditions within the lower aquifer zone. Additionally, samples have not been
collected from wells RI-1 1, RI-7A and RI-7B since the 1987 site remedial investigation. As a result,
groundwater samples will be collected from monitoring wells RI-7A and RI-7B to confirm current
groundwater conditions within this area and evaluate whether additional groundwater samples are
necessary. Updated groundwater analytical data for these two wells will be compared to the historical
1987 remedial investigation groundwater data. Data analysis is necessary for the EPA and the
South Carolina Department of Health and Environmental Control (SCDHEC) to make a protectiveness
determination at the Wamchem Site.
Table 1 summarizes each issue and the status of each recommendation.
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Table 1 - Issues and Recommendations from the September 2019 Five-Year Review Report
Issue
Recommendations
Current
Status
Current Implementation Status Description
Completion Date
(if applicable)
The Consent Decree requires implementation of
deed restrictions to prohibit land uses that could
disturb any part of the selected remedy. The remedy
in the decision document does not include
institutional controls as a component.
Modify the decision document to include
institutional controls and implement
institutional controls.
Ongoing
The implementation status of deed restrictions on
impacted parcels and the modification of the
decision document to update the remedy
components is still ongoing. The specified
milestone date for the recommendation is
9/30/22.
Not Applicable
There are no institutional controls in place on the
adjacent parcels to prevent access to contaminated
groundwater.
Assess the adjacent parcels to determine if
institutional controls are needed to prevent
potential future exposure to contaminated
groundwater.
Ongoing
The oversight party is evaluating the current site
conditions to determine if institutional controls
are necessary on the adjacent parcels to prevent
potential future exposure to contaminated
groundwater. The specified milestone date for the
recommendation is 9/30/22.
Not Applicable
The results and locations of the soil samples
reviewed during the FYR are insufficient to
characterize soil conditions on the Site property.
Review the existing data and sampling
locations to determine whether there are
data gaps.
Ongoing
The oversight party is evaluating the existing soil
data and sampling locations on the Site property
to determine whether there are data gaps. The
specified milestone date for the recommendation
is 9/30/22.
Not Applicable
A residential property is located near the Site
Property.
Review the existing data and sampling
locations to determine whether there are
data gaps.
Ongoing
The oversight party is evaluating the existing
data and sampling locations on the residential
property near the Site property to determine
whether there are data gaps. The specified
milestone date for the recommendation is
9/30/22.
Not Applicable
A temporary approval allowing the PRP to
reconfigure the groundwater treatment system has
expired. The decision document does not include the
modifications to the remedy.
Re-evaluate the current groundwater
remedy to determine whether it is the most
effective to reach the RAOs and modify the
decision document, if appropriate.
Ongoing
The oversight party is evaluating the current
configuration of the groundwater remedy to
determine its effectiveness. The specified
milestone date for the recommendation is
9/30/22.
Not Applicable
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Issue
Recommendations
Current
Status
Current Implementation Status Description
Completion Date
(if applicable)
All South Carolina groundwater was classified for
drinking water purposes (Class GB) effective on
June 28, 1985. The groundwater cleanup levels in
the ROD are based on the Federal AWQC.
Modify the decision document to change
the groundwater cleanup levels to Safe
Drinking Water standards.
Ongoing
The oversight party is evaluating the conditions
of the aquifer to determine the appropriate
groundwater cleanup levels. The specified
milestone date for the recommendation is
September 30, 2022.
Not Applicable
Based on available data, groundwater COC
concentrations exceed the ROD cleanup goals on
Site (Parcel R100 015 000 061A 0000). A private
well on a property nearby the Site has been installed
for household use.
Sample the private well and nearby
monitoring wells RI-7A and RI-7B to
evaluate the water quality conditions on the
nearby property.
Ongoing
Samples are recommended from the private well
and nearby monitoring wells, RI-7A and RI-7B,
to make a protectiveness determination of the
remedy. The specified milestone date for the
recommendation is September 30, 2022.
Not Applicable
The presence of 1,4-dioxane is unknown.
Sample groundwater for 1,4-dioxane and
add to the list of COC through a site
decision document, if appropriate.
Ongoing
Groundwater Samples are recommended to be
analyzed for 1,4-dioxane to determine whether
the list of COC should be updated. The specified
milestone date for the recommendation is
September 30, 2022.
Not Applicable
The groundwater pump-and-treat system discharges
into McCalley's Creek. The only COC monitored in
the effluent is 1,2,4-trichlorobenzene.
Analyze the effluent for all the groundwater
COCs
Ongoing
The effluent of the groundwater pump-and-treat
system should be analyzed for all the
groundwater COCs. The specified milestone date
for the recommendation is September 30, 2022.
Not Applicable
The groundwater pump-and-treat system discharges
into McCalley's Creek.
Evaluate the effluent to ensure there are no
unacceptable risks to aquatic organisms.
Ongoing
The oversight party will evaluate the effluent to
ensure there are no unacceptable risks to aquatic
organisms. The specified milestone date for the
recommendation is September 30, 2022.
Not Applicable
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Figure 1 - Detailed Site Map
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Site Property
Residential Well
Monitoring Well
Former Recovery Well
0.0 3 0.07
United States Environmental Protection Agency
Wamchem, Inc. Superfund Site
City of Burton. Beaufort Count, South Carolina
Replacement Recovery Well
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Protectiveness Statements
Since the 2019 Five-Year Review completion date, the deferred protectiveness determination is still ongoing
for the Warnchem Inc Superfund Site. The protectiveness statement is the following:
A protectiveness determination of the remedy cannot be made at this time until further information is
obtained to evaluate the Site conditions in relation to the nearby residential property. Further
information will be obtained by sampling nearby monitoring wells R/-7A andRI-7B to confirm current
groundwater conditions and evaluate whether additional groundwater samples are necessary. It is
expected that this action will take approximately two years to complete, at which time a protectiveness
determination will be made.
Next Five-Year Review
The next FYR Addendum will be completed by September 30, 2022. The sixth FYR will be completed by
September 17, 2024.
References
Fifth Five-Year Review Report for the Wamchem, Inc. Superfund Site, Burton, Beaufort County,
South Carolina. United States Environmental Protection Agency, Region 4. September 17, 2019.
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