PB98-963130
EPA 541-R98-121
March 1999
EPA Superfund
Explanation of Significant Difference
for the Record of Decision:
Davisville Naval Construction
Battalion Center
North Kingston, RI
9/30/1998
-------
Introduction
This fact sheet presents the Navy's Explanation of
Significant Difference (ESD) on the Record of
Decision (ROD) completed for Site 12 and Site 14 at
NCBC Davisville, Rhode Island. Site 12 is the
Defense Property Disposal Office (DPDO)
Transformer Oil Spill Area at Building 316 in the
West Davisville portion of NCBC Davisville. Site
14 is the Transformer Oil Leak at Building 38 in the
Warehouse Area of the main center at NCBC
Davisville.
Sites 12 and 14 were investigated under the Navy's
Installation Restoration (IR) Program. The IR
Program identifies and investigates environmental
sites of concern that resulted from past military use
and operations. The ROD phase of the IR Program
outlines the selected remedy to address
environmental concerns at a site. The ROD for Sites
12 and 14 was signed on 23 September 1993 and
specified a deed restriction as well as the removal of
fcoil and asphalt/concrete that contained
Concentrations of polychlorinated biphenyls (PCBs)
greater than 10 parts per million (ppm).
Historically, PCBs were a common component in
transformer oil. Remedial actions at both sites have
been completed.
Description of the ESD
The ROD outlined the selected remedy for
environmental impacts at Sites 12 and 14. This ESD
documents a modification to the ROD for Sites 12
and 14 that significantly changes, but does not
fundamentally alter, the selected remedy. The
change to the remedy for Sites 12 and 14 does not
alter the decision to remove asphalt/concrete and soil
containing elevated PCB concentrations. Rather, the
change pertains to the "institutional controls"
component of the remedy that would have prevented
residential reuse of the property. Due to the amount
of PCB removal that has been completed at Sites 12
and 14, soil and concrete at the sites do not pose
unacceptable risks for residential reuse. Therefore,
a deed restriction (institutional controls) on the
property at Sites 12 and 14 is no longer required.
Due to the amount of cleanup at the sites, the 5-year
review called for in the ROD is also not required.
Statutory Basis for Issuance of the ESD
Under the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) Section
117(a), the National Contingency Plan (NCP)
300.435(c), and Environmental Protection Agency
(EPA) guidance (OSWER Directive 9355.3-02), the
lead agency may determine that a significant change
to the selected remedy, as described in a ROD, is
necessary after the ROD is issued. EPA guidance
categorizes changes to a ROD as either non-
significant or minor change; a significant change to
-------
a component of the remedy; or a fundamental change
to the overall remedy. The Navy, as lead agency for
NCBC Davisville, has determined that a significant
change to a component of the remedy (institutional
controls and 5-year review) will be made. However,
the fundamental remedy at Sites 12 and 14 (removal
of asphalt/concrete and soil with PCB concentrations
greater than 10 ppm) has already been completed.
The Navy is required to publish an explanation of a
significant change and the reason the change is being
made.
In accordance with Section 300.435(c) of the NCP,
this ESD and supporting information will be placed
with the Administrative Record for Sites 12 and 14.
The Administrative Record is available for public
review at the Caretaker Site Office, 1330 Davisville
Road, North Kingstown, RI, and the information
repository at the North Kingstown Public Library.
NCBC Description
NCBC Davisville was placed on the National
Priorities List (NPL) in 1989. Pursuant to CERCLA
120(e), the Navy, EPA, and the Rhode Island
Department of Environmental Management
(RIDEM) entered into a Federal Facilities
Agreement (FFA) dated 23 March 1992 regarding
the cleanup of environmental sites at NCBC
Davisville. The FFA sets forth the roles and
responsibilities of each of the parties to the
agreement. Under the IR Program, the Navy is the
" lead agency" for all environmental investigations at
NCBC Davisville in coordination with the EPA
Region I and RIDEM as the federal and state
"supporting agencies". In October 1991, NCBC
Davisville was approved for closure under the Base
Realignment and Closure (BRAC) program. NCBC
Davisville was decommissioned on 25 March 1994
and closed on 1 April 1994.
The main center of NCBC Davisville is located in
the Town of North Kingstown, Rhode Island,
approximately 18 miles south of Providence. The
base is adjacent to the western shore of Narragansett
Bay. A portion of the base, Camp Fogarty, is
located approximately 4 miles west of the main
center in East Greenwich, Rhode Island. Camp
Fogarty was transferred to the U.S. Army in 1993
and is assigned to the Rhode Island National Guard.
Site Description
Site 12 is located in Bay B of Building 316 in V/est
Davisville, approximately 1 mile west of the main
center. West Davisville is bordered to the north and
west by railroad tracks, the east by Mike Road and
to the south by a gravel road adjacent to a section of
Sandhill Brook known as Black Swamp.
Site 14 is located in the South Bay of Building 38 in
the northeastern portion of the Warehouse Area of
NCBC's main center. The area is bounded by
Davisville Road to the north, Davol Pond on the east
and property that was the former Naval Air Station,
Quonset Point and now is the property of the Rhode
Island Development Corporation (RIEDC), on the
west and south.
History of Site 12, Bay B, Building 316, West
Davisville
Building 316 was constructed in 1953 on a fill areal
that was created in 1941 and used as a facility to
manufacture and assemble Quonset hut kits during
World War H Until 1993, Building 316 was used as
a warehouse for storage of various materials. From
1972 to 1984 in Bay B of Building 316, the Navy
DPDO stored transformers (containing PCBs)
pending disposal. In 1977, a forklift punctured a
transformer causing an unknown quantity of oil to
leak within the building. At that time, the oil was
cleaned from the concrete floor.
History of Site 14, South Bay, Building 38,
Warehouse Area
Building 38 was constructed in 1942 in the northeast
corner of the Warehouse Area of the main center.
Building 38 was used as a bulk storage warehouse
for advanced base construction materials. After the
closure of NAS Quonset Point in 1973, Building 38
became part of the facilities used by the Public^
Works Department. Electrical transformers weref
stored in a section of the South Bay and, in 1981, an
-------
oil spillage of an unknown quantity on the asphaltic
concrete floor was noticed.
ft
Enforcement and Remedial Action History for
Site 12
The transformer oil spill was identified in the 1984
Initial Assessment Study (IAS) and, subsequently,
the area was designated as IR Program Site 12. The
LAS recommended confirmatory sampling at Site 12.
Site 12 was included in the March 1992 FFA.
In October 1984, the Navy detected PCBs in a
composite sample of the concrete floor (specifically,
Aroclor-1260 at a concentration of 91 ppm). In
March 1986, PCBs were detected in 15 wipe samples
from the concrete floor at concentrations ranging
from 0.4 to 3.0 micrograms per square inch (fig/in2).
In 1991, the Navy conducted an Interim Remedial
Action (a pre-ROD action) to remove and dispose of
PCB-contaminated concrete and soil from the site. In
post-removal samples, the Navy detected the
presence of PCBs in the subgrade and concrete
KruTTOunding the removal location. In September
™991, EPA collected concrete chip samples from the
surrounding floor to determine the extent of
contamination, with results as high as 1,200 ppm.
The September 1993 ROD for Site 12 called for the
removal of all concrete and soil with PCB
concentrations greater than 10 ppm. Because the
cleanup level of 10 ppm was based on industrial use
of the site, the ROD also required that institutional
controls be implemented to prevent future residential
use of the site and a 5-year review to reassess the
protectiveness of the remedy. Remedial action under
the ROD began in January 1995 with removal of
concrete and soil from areas containing greater than
10 ppm PCB as identified by the EPA survey and
previous sampling events. Several stages of removal
were required before all confirmatory samples were
below 10 ppm PCB as documented in the
Contractor's Close-out Report for the Remediation of
Installation Restoration Program Site 12 (Foster
;ler Environmental Corporation, September
). The remainder of Bay B was then sampled in
a grid pattern. Elevated concentrations of PCBs
were identified in three grid locations adjacent to the
removal area. These additional areas were
subsequently scabbled (scraped) to remove PCBs
greater than 10 ppm. The Navy completed the
removal action and issued a Close-Out report.
Utilizing the recent post-removal data, the Navy
conducted a Human Health Risk Assessment
(HHRA) for the site. The results indicated that
residual PCB concentrations at the site are within
acceptable risk values for unrestricted future use of
the property.
Enforcement and Remedial Action History for
Site 14
The transformer oil spill was identified in the 1984
IAS and, subsequently, the area was designated as IR
Program Site 14. The LAS recommended
confirmatory sampling for Site 14. Site 14 was
included in the March 1992 FFA.
In 1991, the Navy conducted an Interim Remedial
Action to remove PCB-contaminated asphaltic
concrete and soil from the spill site. Post-removal
samples indicated the presence of PCBs in the
subgrade and asphaltic concrete surrounding the
removal location. In September 1991, EPA
collected asphaltic concrete chip samples from the
surrounding floor to determine the extent of
contamination with results as high.as 150 ppm.
In September 1993, the ROD for Site 14 called for
removal of all asphaltic concrete and soil with
concentrations greater than 10 ppm. Because the
cleanup level of 10 ppm was based on industrial use
of the site, the ROD also required that institutional
controls be implemented to prevent future residential
use of the site and a 5-year review to reassess the
protectiveness of the remedy. Remedial action under
the ROD began in January 1995 with removal of
asphaltic concrete and soil from areas containing
greater than 10 ppm PCB as identified by the EPA
survey and previous sampling events. Several stages
of removal were required before all confirmatory
samples were below 10 ppm PCB as documented in
the report Final Closure Summary Report PCB
Contamination Removal Site 14, Building 38, at the
Naval Construction Battalion Center Davisville,
-------
Rhode Island (HRP Associates, November 1996).
Utilizing the post-removal data, the Navy conducted
a HHRA for the site. Results indicated that residual
PCB concentrations are within acceptable risk values
for unrestricted future use of the property.
Summary of the Navy's Record of Decision and
Remedial Action
The ROD for Sites 12 and 14 requires that "All
removal areas and adjacent non-removal areas will
be sampled subsequent to the removal activities to
ensure that cleanup levels have been met. Because
cleanup goals are based on industrial use of the sites,
institutional controls will be implemented to ensure
the sites are not used in the future for residential
use." Furthermore, the ROD required a 5-year
review to reassess the protectiveness of the remedy.
Between 1991 and 1997, the Navy removed
asphalt/concrete and soil at Sites 12 and 14 with
greater than 10 ppm of PCB.
Justification for this ESD
The original clean-up level set in the 1993 ROD for
Sites 12 and 14 was 10 ppm for total PCBs, which
was the level that would be protective of industrial
workers, not residential inhabitants. Therefore, the
ROD required the Navy to implement institutional
controls that included land-use deed restrictions to
prevent residential reuse of the sites and a 5-year
review to reassess the protectiveness of the remedy.
However, the 95% Upper Confidence Limit (UCL)
of the actual confirmatory sample results
demonstrated that the Navy had achieved a much
lower clean-up level across Site 12 (less than 2 ppm)
and Site 14 (less than 4 ppm) than required by the
ROD. These actual clean-up levels are protective of
unrestricted use. Furthermore, RIDEM's
Remediation Regulations, as amended in August
1996, establish a PCB concentration of 10 ppm as
the criterion for residential use. Therefore, the
achieved clean-up levels across the sites are
protective of future residents and, therefore, no
institutional controls are required and no 5-year
review is required for Sites 12 and 14.
Utilizing the information from the post-removal
sampling events at Sites 12 and 14, the Navy.
performed Human Health Risk Assessments (HHR/w
to characterize the potential cancer and non-cancer
risks at the sites as they now exist. The Navy
determined that risks to human health are within
acceptable values such that it is not necessary to
restrict the sites from future residential use.
The HHRA for Site 12 indicated that risk values for
residual PCBs in concrete and are within the EPA's
acceptable cancer risk range of 10"* to 10"6 (one-in-
ten thousand to one-in-one million) and the non-
cancer risks are low (slightly above 1). Furthermore,
in the event that Site 12 is used for future residential
use, the buildings and foundation would likely be
demolished/removed.
The HHRA for Site 14 indicated that risk values for
residual PCBs in soil and asphaltic concrete are
within EPA's acceptable risk range of 104 to 10* and
the non-cancer risks are low (slightly above 1).
Furthermore, in the event that Site 14 is used for
future residential use, the building and foundation
would likely be demolished/removed. ^
Based on the 95% UCL of the post-removal
confirmatory samples and the new HHRA
calculations, the Navy will transfer the property for
unrestricted use. Therefore, the institutional control
component specified in the ROD (deed restriction) is
no longer required nor is a 5-year review required.
Support Agency Comments
EPA and RIDEM reviewed the draft ESD and
provided comments that the Navy has incorporated
into this final document. RIDEM's letter of
concurrence on the ESD was signed on 17 September
1998 and sent out on 21 September 1998. EPA
concurred with the ESD on 30 September 1998.
-------
Affirmation of the Statutory Determinations
The proposed change to the selected remedy
Described in the September 1993 ROD for Site 12
and Site 14 to transfer the property for unrestricted
use will continue to satisfy all statutory requirements
of CERCLA and the NCP. The altered remedy
remains protective of human health and the
environment, complies with federal and state
applicable or relevant and appropriate requirements
(ARARs), and remains cost-effective.
Public Participation
No formal public comment period is required for an
ESD to a previously issued ROD. However, in the
interest of community awareness, the Navy provided
this fact sheet to everyone on the NCBC Davisville
community mailing list and has included the ESD
and supporting information in the Administrative
Record for the sites. In accordance with CERCLA
Section 117(c), the Navy will publish a notice of
availability for review and a brief explanation of the
ESD in the Providence Journal-Bulletin and the
eekty Standard Times.
For More Information
If you have questions about the ESD for Sites 12 and
14 at NCBC Davisville, or if you would like further
information, please contact:
Mr. Philip S. Otis, P.E., Code 1823/PO
Northern Division,
Naval Facilities Engineering Command
10 Industrial Highway, MS # 82
Lester, PA 19113-2090
Tel: (610) 595-0567 ext 155
FAX: (610) 595-0555
Email: psotis@efdnorth . na vf ac . na w . mil
Ms. Christine Williams
Remedial Project Manager
Environmental Protection Agency, Region I
Office of Site Remediation and Restoration
JFK Federal Building (HBT)
Boston, MA 02203-2211
Phone: (617) 573-5736 Fax: (617) 223-5580
Mr. Richard Gottlieb, P.E.
Principal Sanitary Engineer
R.I. Dept. of Environmental Management
Office of Waste Management
235 Promenade Street
Providence, RI02908-5767
Phone: (401) 222-2797, ext. 7138
Fax: (401) 222-3813
Declaration
The issuance of this ESD for Sites 12 and 14 at
NCBC Davisville, Rhode Island is approved.
Philip
BRAC Environmental Coordinator
NCBC Davisville, RI
Date
------- |