Categorical Exclusion Determination
Office of NEPA Policy and Compliance
January 12, 2017
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Legacy Management is proposing to drill 24 new groundwater sampling wells in the immediate vicinity of the Tuba City, Arizona, Disposal Site. The drilling method and equipment need to penetrate loose dune sand and consolidated sand and gravel up to 20 feet thick and into the underlying fine-grained Navajo Sandstone, which is generally poorly consolidated, to the desired depth. The diameter of the borehole would be sufficient to allow uniform placement of an artificial sand pack and annular sealants within a 2-inch annulus surrounding the 4-inch well screen and casing (nominal 8-inch diameter borehole).