Limited field investigation for the 100-FR-1 Operable Unit

This limited field investigation (LFI) report summarizes the data collection and analysis activities conducted during the 100-FR-1 Source Operable Unit LFI and the associated qualitative risk assessment (QRA), and makes recommendations on the continued candidacy of high-priority sites for interim remedial measures (IRM). The results and recommendations presented in this report are generally independent of future land use scenarios. This report is unique in that it is based on Hanford-specific agreements discussed in the Hanford Federal Facility Agreement ' and Consent Order (Ecology et al. 1990), the Hanford Site Risk Assessment Methodology (DOE-RL 1994a), the RCRA Remedial InvestigationIFeasibility Study Work Planfor the 100-FR-1 Operable Unit (DOE-RL 1992a), and the Hanford Past-Practice Strategy (HPPS) (DOE-RL 1991), and must be viewed in this context. The HPPS, described and justified in The Hanford Federal Facility Agreement and Consent Order Change Package (Ecology et al. 1991), emphasizes initiating and completing waste site cleanup through interim actions. An LFI is required when existing data are insufficient to formulate a conceptual model and perform a QRA. The purpose of the report is to identify those sites that are recommended to remain as candidates for IRM, provide a preliminary summary of site characterization studies, refine the conceptual model as needed, identify contaminant- and location-specific applicable or relevant and appropriate requirements (ARAR), and provide a qualitative assessment of the risks associated with the sites. This assessment includes consideration of whether contaminant concentrations pose an unacceptable risk that warrants action through IRM