[Federal Register Volume 64, Number 30 (Tuesday, February 16, 1999)]
[Notices]
[Pages 7636-7637]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-3653]
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DEPARTMENT OF ENERGY
Floodplain and Wetlands Involvement Notification for the Pond B
Dam Repair Project at the Savannah River Site (SSR)
AGENCY: Department of Energy (DOE).
ACTION: Notification of floodplain and wetlands involvement.
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SUMMARY: DOE proposes to repair the earthen dam impounding Pond B, one
of the former reactor cooling reservoirs located on SSR. The results of
recent inspections have indicated that seepage conditions and erosion
threaten the structural stability of the dam. Due to former reactor
operation, Pond B contains low levels of radionuclide contamination.
The proposed action is needed to increase the stability of the
structure and reduce the risk of failure. The proposed action entails
the placement of a soil blanket over the downstream slope and toe of
the Pond B dam. Some areas encompassed by this repair are located in
both 100-year floodplain and jurisdictional wetlands. In accordance
with 10 CFR 1022, DOE will prepare a floodplain and wetlands assessment
and will perform this proposed action in a manner so as to avoid or
minimize potential harm to or within the affected floodplain or
wetlands.
DATES: Comments on the proposed action are due on or before March 3,
1999.
ADDRESSES: Comments regarding this assessment should be addressed to
Andrew R. Grainer, National Environmental Policy Act (NEPA) Compliance
Officer, Savannah River Operations Office, Building 742-A, Room 183,
Aiken, South Carolina 29808. The fax/phone number is (800) 881-7292.
The e-mail address is nepa@srs.gov.
FOR FURTHER INFORMATION ON GENERAL FLOODPLAIN/WETLANDS ENVIRONMENTAL
REVIEW REQUIREMENTS, CONTACT: Ms. Carol M. Borgstrom, Director, Office
of NEPA Policy and Assistance (EH-42), U.S. Department of Energy, 1000
Independence Avenue, SW., Washington, DC 20585. Telephone (202) 586-
4600 or (800) 472-2756.
A location map showing SRS and further information can be obtained
from the Savannah River Operations Office (see ADDRESSES above).
SUPPLEMENTARY INFORMATION: Pond B is one of the former production
reactor cooling ponds on SRS, located near Aiken, South Carolina. Due
to releases during the period of reactor operation, Pond B contains low
levels of radionuclide contamination within the lakebed sediments and
waters of the impoundment. The dam is an earthen embankment constructed
in 1959-1960. Recent inspections of this structure by SRS engineers and
the Federal Energy Regulatory Commission have found seepage conditions
and erosion which threaten the stability of the dam.
The DOE Savannah River Operations Office (SR) proposes to make
repairs to the downstream slope and toe of the Pond B dam. These
repairs would entail the following: (1) stripping of topsoil and
vegetation on the face of the dam and at least a 50 to 100 foot area
along the toe of the dam; (2) construction of a rock core underdrain
system on the face of the dam and along the entire toe of the dam; (3)
installation of weir boxes, piezometers, and lateral movement monitors;
(4) and placement of an additional 30,000-50,000 cubic yards of
previous material in the form of a soil blanket on the downstream face
of the dam. The purpose of the proposed action is to increase the
stability of the dam and reduce the risk of failure.
The area of the floodplain and wetlands is dominated by an
overstory of tulip tree (Lireodendron tulipifera) and red maple (Acer
rubrum). A number of species are present in the understory, including
tulip tree, red maple, red bay (Persea borbonia), and sweetgum
(Liquidambar styraciflua). The herbaceous layer is dominated by
maidencane (Panicum Hemitomon), sensitive fern (Onoclea sensibilis),
and rush (Juncus spp.). Soils in this area are mapped as Fluvaquents
and are listed for SRS as hydric soils.
The wetland area below the dam is believed to have been natural
wetlands prior to the construction of Pond B dam, although soil
saturation is likely to have increased as a result of the man-made
impoundment. Approximately 3 to 4 acres of wetlands would be impacted
by the extension of the toe of the dam with the proposed placement of a
soil blanket.
During implementation of the proposed action, project activities
that could take place in floodplain and wetland areas would include
grading,
[[Page 7637]]
clearing of vegetation, and placement of fill materials. Some of these
activities would require temporary construction access. A number of
mitigation activities would be implemented to minimize potential
impacts to the floodplain and wetland areas. Operation of construction
equipment in the floodplain and wetland areas would be minimized.
Depending upon the type of mechanized construction equipment to be
employed, the use of platform support mats may be required to minimize
the impacts to the wetland soils in the project area. Silt fences and
other erosion control structures as needed would be installed to ensure
there is no deposition in the downslope wetland areas. Best management
practices would be employed during construction and maintenance
activities associated with this proposed action.
In accordance with DOE regulations for compliance with floodplain
and wetland environmental review requirements (10 CFR 1022), DOE-SR
will prepare a floodplain and wetlands assessment for this proposed DOE
action. The assessment will be included in the environmental assessment
(EA) being prepared for the proposed action in accordance with the
requirements (EA) being prepared for the proposed action in accordance
with the requirements of NEPA. A floodplain statement of findings will
be included in any finding of no significant impact that is issued
following the completion of the EA or may be issued separately.
Issued in Aiken, SC, on February 3, 1999.
Lowell E. Tripp,
Director, Engineering and Analysis Division, Savannah River Operations
Office.
[FR Doc. 99-3653 Filed 2-12-99; 8:45 am]
BILLING CODE 6450-01-M
