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

The Environmental Protection Agency (EPA) Region 8 announces the deletion of the Surface Deletion Area of the Rocky Mountain Arsenal National Priorities List (RMA/NPL) Site 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), as amended. EPA and the State of Colorado, through the Colorado Department of Public Health and Environment (CDPHE), have determined that the Surface Deletion Area of the RMA/NPL Site 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 (soil, surface water, sediment) and structures media only and excludes the groundwater media of the Surface Deletion Area of the On-Post OU of the RMA/NPL Site. The Selected Perimeter Area of the On-Post OU RMA/NPL Site, composed of the surface, structures, and groundwater media within an additional 4,930 acres, also is being deleted at this time. The rest of the On-Post and Off-Post OUs will remain on the NPL. This partial deletion of the Surface Deletion Area will not change Appendix B of 40 CFR part 300, which was previously amended in January 2003 (68 FR 2699) to reflect that a partial deletion of 1.5 square miles from the RMA/NPL Site had occurred.