Engineering evaluation/cost analysis for the proposed removal action at the Southeast Drainage near the Weldon Spring Site, Weldon Spring, Missouri

The engineering evaluation/cost analysis (EE/CA) has been prepared to support the proposed removal of contaminated sediment from selected portions of the Southeast Drainage as part of cleanup activities being conducted at the Weldon Spring site in St. Charles County, Missouri, by the U.S. Department of Energy (DOE). The cleanup activities are conducted in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended, incorporating the values of the National Environmental Policy Act (NEPA). The Weldon Spring site is located near the town of Weldon Spring, about 48 km (30 mi) west of St. Louis. It consists of two noncontiguous areas: the chemical plant area and a limestone quarry about 6.4 km (4 mi) south-southwest of the chemical plant area. The Southeast Drainage is a natural 2.4-km (1.5-mi) channel that carries surface runoff to the Missouri River from the southern portion of the chemical plant area and a small portion of the ordnance works area (part of the Weldon Spring Training Area) south of the groundwater divide. The drainage became contaminated as a result of past activities of the U.S. Army and the DOE (and its predecessors)