SUPPLEMENTARY INFORMATION:

The portion of the site to be deleted from the NPL is: Callahan property, OU3 of the Ellisville Superfund Site, Wildwood, Missouri. A Notice of Intent for Partial Deletion for this Site was published in the Federal Register (81 FR 14813) on March 18, 2016.

The original closing date for comments on the Notice of Intent for Partial Deletion was April 18, 2016. However, the EPA continued to accept public comments at the request of the City of Wildwood until May 18, 2016. Twenty-five public comments were received and the public concerns expressed in the comments were: Public health risks that may still remain at the subsite, additional time to observe the subsite for possible long-term effects, future construction at the subsite will disturb contaminants left at the site, dioxin and polychlorinated biphenyls (PCBs) contaminants were not evaluated or were being left in place, groundwater was not evaluated, vapor intrusion issues were not evaluated, and that five year reviews should be conducted at the subsite. The EPA removed all contaminated soil down to bedrock at the Callahan subsite then collected confirmation samples on the sidewalls to confirm that clean-up was achieved both vertically and laterally. EPA considers that all contaminants of concern in the site soils above clean-up criteria were removed from the Callahan subsite. Therefore, there is not contamination to disturb through future construction. PCBs and dioxin were not detected above clean-up criteria and are not considered contaminants of concern at the Callahan subsite. The EPA conducted a groundwater investigation at the property where three wells were installed then sampled. All groundwater samples at the Callahan subsite were non-detect for contaminants of concern. Indoor air sampling was not conducted at residential homes near the Callahan subsite since all impacted soil was removed from the site and the groundwater is not impacted with contamination. The EPA considers there is no pathway for vapor intrusion. The EPA determined all threats to public health and the environment requiring action have been addressed and that the Callahan subsite meets the criteria for unlimited use/unrestricted exposure (UU/UE). Since the Callahan subsite meets UU/UE requirements a five-year review is not required for the Callahan subsite. Based on an evaluation of all requirements under 40 CFR 300.425(e) and 60 FR 55466-55467, the EPA concluded that the Callahan subsite could and should be deleted from the NPL. A responsiveness summary was prepared and placed in both the docket, EPA-HQ-SFUND-1983-0002, on www.regulations.gov, and in the local repositories listed above.

The EPA maintains the NPL as the list of sites that appear to present a significant risk to public health, welfare, or the environment. Deletion of a site from the NPL does not preclude further remedial action. Whenever there is a significant release from a site deleted from the NPL, the deleted site may be restored to the NPL without application of the hazard ranking system. Deletion of portions of a site from the NPL does not affect responsible party liability, in the unlikely event that future conditions warrant further actions.

For reasons set out in the preamble, 40 CFR part 300 is amended as follows:

1. The authority citation for part 300 continues to read as follows:

Authority: 33 U.S.C. 1321(c)(2); 42 U.S.C. 9601-9657; E.O. 12777, 56 FR 54757, 3 CFR, 1991 Comp., p. 351; E.O. 12580, 52 FR 2923; 3 CFR, 1987 Comp., p. 193.

2. Table 1 of Appendix B to part 300 is amended by revising the entry “MO”, “Ellisville Site”, “Ellisville” to read as follows:

82 FR 32646