[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 [email protected].

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