Solid Waste Storage Area (SWSA) 6, located at the US Department of Energy (DOE) Oak Ridge National Laboratory (ORNL) facility, is a shallow land burial site for low-level radioactive waste (LLW) and other waste types. Wastes were disposed of in unlined trenches and auger holes from 1969 until May 1986, when it was determined that Resource Conservation and Recovery Act (RCRA) regulated wastes were being disposed of there. DOE closed SWSA 6 until changes in operating procedures prevented the disposal of RCRA wastes at SWSA 6. The site, which reopened for waste disposal activities in July 1986, is the only currently operated disposal area for low-level radioactive waste at ORNL. This report provides the results of the 1998 RCRA groundwater assessment monitoring. The monitoring was performed in accordance with the proposed routine monitoring plan recommended in the 1996 EMP. Section 2 provides pertinent background on SWSA 6. Section 3 presents the 1998 monitoring results and discusses the results in terms of any significant changes from previous monitoring efforts. Section 4 provides recommendations for changes in monitoring based on the 1998 results. References are provided in Section 5. Appendix A provides the 1998 RCRA Sampling Data and Appendix B provides a summary of 1998 Quality Assurance results.