NNSA: Wetland Assessment For LANL Water Line Replacement Available For Public Comment


The Department of Energy National Nuclear Security Administration’s (DOE/NNSA) Los Alamos Field Office has issued a Wetland Assessment for the Replacement Water Lines from Technical Area 48 to Technical Area 55 Project (Wetland Assessment) for a 15-day public review and comment period commencing with publication of this notice.

DOE/NNSA is proposing to install two 12-inch water lines along an alignment from TA-48 to Pecos Road on the east side of TA-55 at Los Alamos National Laboratory. The proposed water lines will replace aging cast iron pipes that provide water for fire suppression to buildings within TA-55, and potable water to other areas in the Pajarito Corridor. The proposed project will be located on the mesa top to the south of a Mortandad Canyon tributary. Two 12-inch high-density polyethylene (HDPE) water lines (one high pressure and one low pressure) would be installed in parallel starting at Gamma Ray Road along the south of TA-48, continue along the north fenced boundary of TA-55, and tie into existing high- and low- pressure waterlines on Pecos Drive.

Two small wetlands exist along the area of the proposed project: one in TA-48, and one in TA-55. The proposed project route would pass to the south of the TA-48 wetland, and under the TA-55 wetland. To avoid trenching in the TA-55 wetland, horizontal directional drilling is proposed at approximately 1-2 feet below, and for a length of approximately 66 feet under, the TA-55 wetland.

After the close of the public comment period and prior to issuing a Wetland Statement of Findings DOE/NNSA will reevaluate the alternatives to the proposed action in a wetland, identify mitigation measures that would avoid or minimize impacts to the wetland and take into account all substantive comments received during the public comment period. The Wetland Assessment can be accessed online at https://energy.gov/nepa/articles/los-alamos-national-laboratory-wetland-assessment-replacement-water-lines-technical