Site Characterization Work Plan for the Gnome-Coach Site, New Mexico (Rev. 1, January 2002)

Project Gnome was the first nuclear experiment conducted under the U.S. Atomic Energy Commission (AEC), predecessor to the U.S. Department of Energy (DOE), Plowshare Program. The Plowshare Program focused on developing nuclear devices exclusively for peaceful purposes. The intent of the Gnome experiment was to evaluate the effects of a nuclear detonation in a salt medium. Historically, Project Gnome consisted of a single detonation of a nuclear device on December 10, 1961 with the Salado Formation. Since the Gnome detonation, the AEC/DOE has conducted surface restoration, site reconnaissance, and decontamination and decommissioning activities at the site. In addition, annual groundwater sampling is performed under a long-term hydrological monitoring program begun in 1972. Coach, an experiment to be located near the Gnome project, was initially scheduled for 1963. Although construction and rehabilitation were completed for Coach, the experiment was canceled and never executed. Known collectively as Project Gnome-Coach, the site is located approximately 25 miles east of Carlsbad, New Mexico, in Eddy County, and is comprised of nearly 680 acres, of which approximately 60 acres are disturbed from the combined AEC/DOE operations. The scope of this work plan is to document the environmental objectives and the proposed technical site investigation strategies that will be utilized for the site characterization of the project. The subsurface at the Gnome-Coach site has two contaminant sources that are fundamentally different in terms of both their stratigraphic location and release mechanism. The goal of this characterization is to collect data of sufficient quantity and quality to establish current site conditions and to use the data to identify and evaluate if further action is required to protect human health and the environment and achieve permanent closure of the site. The results of these activities will be presented in a subsequent corrective action decision document