DOE-EM Issues Notice Of Proposed Floodplain Action For Sampling And Remediation Within North Ancho Canyon Floodplain


The Department of Energy (DOE) Office of Environmental Management Los Alamos Field  Office (EM-LA) is issuing this notice of proposed floodplain action for sampling and  remediation of Solid Waste Management Units (SWMUs) 39-001(a), 39-001(b), 39-006(a), and  39-010 in North Ancho Canyon. 

EM-LA has determined that the proposed action within North Ancho Canyon at Technical Area  (TA) 39 at Los Alamos National Laboratory would occur within a 100-year floodplain. EM-LA  is proposing the collection of soil investigation samples and removal of contaminated soil at four 

locations within TA-39. The activities involve characterization, confirmation sampling, and  remediation activities at North Ancho Canyon Aggregate Area SWMUs 39-001(a), 39-001(b),  39-006(a), and 39-010. In addition, wells and boreholes associated with SWMUs 39-001(a) and  39-001(b) would be plugged and abandoned near and within the floodplain. This project is part  of the cleanup under the 2016 Compliance Order on Consent (Consent Order) between the State  of New Mexico Environment Department and DOE.  

Pursuant to 10 Code of Federal Regulations Part 1022 the 15-day public comment period for this  proposed floodplain action commences with publication of this notice and will conclude on  May 20, 2022. Following the conclusion of the public comment period, DOE will reevaluate the  alternatives to the proposed floodplain action and the mitigating measures, taking into account all  substantive comments received, and prepare a floodplain statement of findings. 

The floodplain assessment, including maps of proposed activity locations within North Ancho  Canyon, may be viewed on the Los Alamos Legacy Cleanup Electronic Public Reading Room at 

To submit comments, please contact the EM-LA National Environmental Policy Act Compliance  Officer at To learn more about the Consent Order, please visit: center/2016-consent-order