National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List

The United States Environmental Protection Agency (EPA) Region 8 announces the deletion of the Peripheral Operable Unit (OU) of the Department of Energy (DOE) Rocky Flats Plant and Operable Unit 3 (OU 3), also referred to as the Offsite Areas, encompassing approximately 25,413 acres, from the National Priorities List (NPL). The NPL constitutes Appendix B of 40 CFR part 300, which is the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), which EPA promulgated pursuant to Section 105 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Rocky Flats Plant means the property owned by the United States Government, also known as Rocky Flats, Rocky Flats Site, or Rocky Flats Environmental Technology Site (RFETS) as shown in figure 1. The Rocky Flats Plant is divided into the Central and Peripheral Operable Units (Figure 2) which contain 1,308 and 4,933 acres, respectively, and OU 3 (Figure 3) which contains approximately 20,480 acres. The 3 referenced figures are available in the http://www.regulations.gov index identified by Docket ID no. EPA- HQ-SFUND-1989-0011. EPA and the State of Colorado, through the Colorado Department of Public Health and Environment (CDPHE), have determined that the Peripheral OU of the Rocky Flats Plant and OU 3 (Offsite Areas) poses no significant threat to public health or the environment and, therefore, no further remedial measures pursuant to CERCLA are appropriate. This partial deletion pertains to the surface media (soil, surface water, sediment) and subsurface media, including groundwater, within the Peripheral OU and OU 3 of the Rocky Flats Plant. The Central OU will remain on the NPL.