Groundwater Protection Program Calendar Year 1998 Evaluation of Groundwater Quality Data for the Upper East Fork Poplar Creek Hydrogeologic Regime at the U.S. Department of Energy Y-12 Plant, Oak Ridge, Tennessee

This report presents an evaluation of the water quality monitoring data obtained by the Y-12 Plant Groundwater Protection Program (GWPP) in the Upper East Fork Poplar Creek Hydrogeologic Regime (East Fork Regime) during calendar year (CY) 1998. The East Fork Regime contains many confirmed and potential sources of groundwater and surface water contamination associated with the U.S. Department of Energy (DOE) Oak Ridge Y-12 Plant. Applicable provisions of DOE Order 5400.1A - General Environmental Protection Program - require evaluation of groundwater and surface water quality near the Y-12 Plant to: (1) gauge groundwater quality in areas that are, or could be, affected by plant operations, (2) determine the quality of surface water and groundwater where contaminants are most likely to migrate beyond the DOE Oak Ridge Reservation (ORR) property line, and (3) identify and characterize long-term trends in groundwater quality at the Y-12 Plant. The following sections of this report contain relevant background information (Section 2.0); describe the results of the respective data evaluations required under DOE Order 5400.1A (Section 3.0); summarize significant findings of each evaluation (Section 4.0); and list the technical reports and regulatory documents cited for more detailed information (Section 5.0). All of the illustrations (maps and trend graphs) and data summary tables referenced in each section are presented in Appendix A and Appendix B, respectively