EPA Superfund Site

ROCKY FLATS PLANT (USDOE)

CO | EPA ID CO7890010526

About this site’s exposure pathways: As of September 2025, the Rocky Flats Plant (USDOE) Superfund site is considered Insufficient Data to make a Human Exposure evaluation (HEID) because of a newly identified contaminant release. The detection of perfluorooctanoic acid and perfluorooctane sulfonate (collectively, PFAS) in water samples collected in the Central Operable Unit beginning in 2019 prompted a protectiveness deferred statement in the most recent five-year review (FYR). A FYR Addendum, initially planned to evaluate the potential risk from PFAS to human and ecological receptors at the site and determine the protectiveness of the remedy, was determined to no longer be feasible in the timeframe prior to the next FYR. Therefore, the next protectiveness determination will be made during the next FYR. Department of Energy (DOE) is initiating a Remedial Investigation (RI) for further PFAS sampling to determine the extent of potential PFAS contamination. The site was previously categorized as Human Exposure Under Control. There are no known unacceptable exposure pathways and institutional controls are in place to prevent or limit exposure to previously identified surface water, groundwater and soil contaminants.
EPA uses this Human Exposure status when there is a lack of evidence to suggest that actual or reasonably anticipated human exposures are occurring, and that those exposures are above acceptable risk-based levels. The planned activities to collect sufficient information to evaluate this new exposure pathway and/or contaminants(s) are the following: 1) Completion of a RI to evaluate the nature and extent of the potential PFAS contamination in water, sediment, and soils, 2) Evaluation of risk to human health and the environment. EPA and US Department of Energy Legacy Management (DOE LM) currently anticipates that there will be sufficient data to make a Human Exposure evaluation by August 2027, because the issues and recommendations identified in the FYR will have been completed.