Office of Los Alamos Site Operations, National Nuclear Security Administration; Notice of Floodplain Involvement for the Proposed Future Disposition of Certain Cerro Grande Fire Flood and Sediment Retention Structures at Los Alamos National Laboratory, Los Alamos, NM

AGENCY:

National Nuclear Security Administration, Office of Los Alamos Site Operations, DOE.

ACTION:

Notice of floodplain involvement.

SUMMARY:

The Department of Energy (DOE), National Nuclear Security Administration (NNSA), Office of Los Alamos Site Operations proposes to demolish the above ground portions of two structures built to retain or divert flood waters at Los Alamos National Laboratory (LANL) and retain five others intact with continuing maintenance, which could include periodic sediment removal actions; these structures were constructed in the wake of the Cerro Grande Fire in 2000 as emergency actions to address post fire danger to LANL facilities from floods and sediment movement. All of these structures are located in floodplains; one structure that is being proposed for remaining intact, the Los Alamos Canyon gabion weir, is associated with an area that might develop into a wetland. In accordance with 10 CFR part 1022, DOE has prepared a floodplain/wetland assessment and will perform this proposed action in a manner so as to avoid or minimize potential harm to or within the affected floodplain.

DATES:

Comments are due to the address below no later than July 12, 2002.

ADDRESSES:

Written comments should be addressed to: Elizabeth Withers, Department of Energy, National Nuclear Security Administration, Los Alamos Area Office, 528 35th Street, Los Alamos, NM 87544, or submit them to the Mail Room at the above address between the hours of 8 a.m. and 4:30 p.m., Monday through Friday. Written comments may also be sent electronically to: ewithers@doeal.gov or by facsimile to (505) 667-9998.

FOR FURTHER INFORMATION CONTACT:

Karen Agogino, Department of Energy, National Nuclear Security Administration, Albuquerque Field Office, Pennsylvania and H Street, Kirtland Air Force Base, Albuquerque, NM 87116. Telephone (505) 845-6100, facsimile (505) 284-7107.

For Further Information on General DOE Floodplain Environmental Review Requirements, contact: Carol M. Borgstrom, Director, Office of NEPA Policy and Compliance, EH-42, Department of Energy, 100 Independence Avenue, SW., Washington DC 20585-0119. Telephone (202) 586-4600 or (800) 472-2756, facsimile (202) 586-7031.

SUPPLEMENTARY INFORMATION:

NNSA constructed several permanent flood and sediment retention structures within various canyons across LANL during the four months immediately following the devastating Cerro Grande Fire that occurred in mid-2000. These structures and their locations are as follows:

• A substantial concrete flood retention structure and a steel flood diversion wall were built within Pajarito Canyon;
• A low-head rock gabion weir together with a sediment detention basin were built in Los Alamos Canyon;
• Four concrete road reinforcement areas were built along State Road 501 and Anchor Ranch Road at their crossings of Two-Mile, Pajarito and Water Canyons; and
• Reinforcements were made to the Los Alamos Canyon Reservoir near the head of Los Alamos Canyon [note: the Reservoir is located on property administered by the U.S. Department of Agriculture, Forest Service, Santa Fe National Forest and is not subject to DOE's current proposal].

These structures, along with other various actions and activities taken to extinguish the fire and as recovery actions in the wake of the fire were subject to the emergency provisions of the National Environmental Policy Act (NEPA); a Special Environmental Analysis (DOE/SEA-03) was prepared to analyze the impacts of the actions taken by NNSA rather than normal NEPA documents. However, the ultimate disposition of these permanent structures was not identified and analyzed in the Special Environmental Analysis issued in September 2000. The disposition of the seven permanent structures located within the boundaries of LANL is the subject of a separate NEPA Environmental Assessment (EA). NNSA's proposed disposition action for these seven structures is to partially breach the above ground portions of the flood retention structure in Pajarito Canyon, remove the above ground portions of the steel flood diversion wall in Pajarito Canyon, and retain the remaining five structures intact and continue to routinely maintain these structures into the foreseeable future (which is defined for the purposes of this proposal as being the next ten years). Routine maintenance of these structures may include accumulated sediment removal. Other alternatives considered are the No Action Alternative (consisting of the retention of all the structures intact with on-going continuation of routine maintenance) and the Disassembly of All Structures Alternative (consisting of the demolition of all above ground portions of all the subject structures).

In accordance with DOE regulations for compliance with floodplain and wetlands environmental review requirements (10 CFR part 1022), NNSA has also prepared a floodplain/wetland assessment for this action, which is part of the NEPA draft EA. The draft EA (containing the floodplain/wetland assessment) is available by contacting Elizabeth Withers at the previously identified addresses, phone and facsimile numbers. The draft EA (containing the floodplain/wetland assessment) is also available for review at the DOE Reading Room at the Los Alamos Outreach Center, 1619 Central Avenue, Los Alamos, NM 878544; and the DOE Reading Room at the Zimmerman Library, University of New Mexico, Albuquerque, NM 87131. The NNSA will publish a floodplain statement of findings for this project in the Federal Register no sooner than July 12, 2002.