Proposed plan for remedial action at the quarry residuals operable unit of the Weldon Spring Site

This proposed plan addresses the management of contamination present in various components of the quarry residuals operable unit (QROU) of the Weldon Spring site, which is located in St. Charles County, Missouri. The QROU consists of (1) residual waste at the quarry proper; (2) the Femme Osage Slough, Little Femme Osage Creek, and Femme Osage Creek; and (3) quarry groundwater located primarily north of the slough. Potential impacts to the St. Charles County well field downgradient of the quarry area are also being addressed as part of the evaluations for this operable unit. Remedial activities for the QROU will be conducted by the US Department of Energy (DOE) in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. As part of the remedial investigation/feasibility study (RI/FS) process required for the QROU under CERCLA, three major evaluation documents have been prepared to support cleanup decisions for this operable unit. decisions for this operable unit