Annual Groundwater Detection Monitoring Report for the Idaho CERCLA Disposal Facility (2008)

This report presents the data collected for groundwater detection monitoring at the Idaho Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) Disposal Facility (ICDF) during calendar year 2008. The detection-monitoring program developed for the ICDF groundwater-monitoring wells is applicable to six wells completed in the uppermost portion of the Snake River Plain Aquifer − five wells downgradient of the ICDF and one well upgradient. The ICDF detection-monitoring program was established to meet the substantive requirements of Title 40 Code of Federal Regulations (CFR) Parts 264.97 and 264.98, which are applicable or relevant and appropriate requirements under CERCLA. Semiannual groundwater samples were collected and analyzed for indicator parameters in March and September. The indicator parameters focus on constituents that are found in higher concentrations in ICDF leachate than in groundwater (bicarbonate alkalinity, sulfate, U-233, U-234, and U-238). The only detection monitoring limits that were exceeded were for bicarbonate alkalinity. Bicarbonate alkalinity is naturally occurring in groundwater. Bicarbonate alkalinity found in ICDF detection monitoring wells is not a result of waste migration from the ICDF landfill or the evaporation pond. The U.S. Department of Energy will continue with detection monitoring for the ICDF, which is semiannual sampling for indicator parameters