Contaminants of Potential Concern in the 300-FF-5 Operable Unit: Expanded Annual Groundwater Report for Fiscal Year 2004

This report satisfies requirements in the Operations and Maintenance Plan for the 300-FF-5 Operable Unit (DOE/RL-95-73/Rev.1) to provide detailed information, beyond that provided in the regular annual groundwater report (e.g., PNNL-15070), on groundwater conditions. The purpose is to characterize current conditions; provide a basis for changes to the monitoring schedules; and provide technical information to support the second 5-year review of the record-of-decision for the operable unit. Key topics include historical trends in the levels of various contaminants; updating the list of contaminants of potential concern; conceptual site models for uranium (300 Area) and tritium (618-11 waste site sub-region); performance of the interim actions under the current record-of-decision; and analysis of the applicability of Monitored Natural Attenuation as a remedial action alternative