[en] The US Department of Energy (DOE), under its Surplus Facilities Management Program (SFMP), is responsible for cleanup activities at the Weldon Spring site, Weldon Spring, Missouri. The site consists of a raffinate pits and chemical plant area and a quarry. This baseline risk evaluation has been prepared to support a proposed response action for management of contaminated bulk wastes in the quarry. The quarry became chemically and radioactively contaminated as a result of various wastes that were disposed of there between 1942 and 1969. This risk evaluation assesses potential impacts on human health and the environment that may result from exposure to releases of contaminants from the quarry under current site conditions. Risk assessment is a key component of the remedial investigation/feasibility study (RI/FS) process, as identified in guidance from the US Environmental Protection Agency (EPA); this process addresses sites subject to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, as amended by the Superfund Amendments and Reauthorization Act of 1986. Response actions at the Weldon Spring quarry are subject to CERCLA requirements because the quarry is listed on the EPA's National Priorities List. The DOE is also responsible for complying with the requirements of the National Environmental Policy Act (NEPA) of 1969, which requires federal agencies to consider the environmental consequences of a proposed action as part of the decision-making process for that action. Although this document has not been prepared to fulfill specific NEPA requirements, the analyses contained herein --- along with the analyses provided in the remedial investigation, feasibility study, and other supporting documents --- are intended to meet the environmental assessment requirements of NEPA