To support remediation and the site cleanup design, DOE assessed all Moab site soils for radiological contamination. Boreholes for logging gamma radiation measurements as an indicator of contamination were drilled at 90-foot intervals across the site. This assessment provides a general sense of where the highest concentrations of radiological contaminants in soil exist. The data were documented in the Radiological Assessment for Non-Pile Areas of the Moab Project Site, which details the measurement techniques, instruments, procedures, and results. All site soils will be cleaned up to applicable U.S. Environmental Protection Agency (EPA) standards.
In 2003, DOE began cleaning up radiologically contaminated soil in non-pile (off-pile) areas of the Moab site. This non-pile soils remediation has resulted in a reduction of the contaminated footprint by 133 acres. The linked figure shows the areas that have been remediated and the date range of when the cleanup took place. The figure also shows the extent and estimated depth of contamination in the remaining areas that were assessed. Some areas on the figure are identfied as supplemental standards. EPA allows the application of supplemental standards that establish alternate cleanup levels for soil contaminated with uranium mill tailings based on an assessment of risk to human health and the environment for specific exposure scenarios.
To support these non-pile soil cleanups, or interim actions, prior to the start of tailings pile removal, and in compliance with federal floodplain and wetlands regulations, DOE prepared a Floodplain and Wetlands Assessment of the potential effects planned non-pile cleanup actions might have on the floodplain or wetlands at the site. In addition, DOE issued a Floodplain Statement of Findings in accordance with 10 Code of Federal Regulations 1022.