Limited field investigation report for the 100-NR-2 Operable Unit, Hanford Site, Richland, Washington

摘要

This limited field investigation (LFI) was conducted to determine the nature and extent of hazardous and radioactive materials present in the groundwater. This information is used to assess the applicability of interim remedial measures (IRM) for reducing human health and environmental risks within the 100-NR-2 Groundwater Operable Unit. Sampling of existing wells and the installation of one new monitoring well were the methods of investigation used during this LFI. Analytical data were subjected to validation under the Resource Conservation and Recovery Act (RCRA) program. The groundwater analyses were screened to identify contaminants of potential concern (COPC). This screening method eliminated from further consideration constituents that were below background. Constituents considered nontoxic to humans were eliminated from the human health evaluation. Data inconsistency and blank contamination were also evaluated in the screening process. These COPC were evaluated further in the qualitative risk assessment (QRA). A QRA was performed using conservative analyses. The human health risk assessment evaluated frequent-use and occasional-use scenarios. The QRA analysis indicates that there is a medium human health risk for the frequent-use scenario and a low human health risk for the occasional-use scenario. Neither of these land use scenarios currently occur at the site.