03-958. National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List

AGENCY:

Environmental Protection Agency.

ACTION:

Notice of partial deletion of the Rocky Mountain Arsenal National Priorities List Site from the National Priorities List.

SUMMARY:

The Environmental Protection Agency (EPA) Region 8 announces the deletion of the Western Tier Parcel 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 Western Tier Parcel 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 only to the Western Tier Parcel of the RMA/NPL Site and does not include the other portions of the Site, which will remain on the NPL.

EFFECTIVE DATE:

January 21, 2003.

FOR FURTHER INFORMATION CONTACT:

Ms. Laura Williams, Remedial Project Manager (8EPR-F), U.S. EPA, Region 8, 999 18th Street, Suite 300, Denver, Colorado 80202-2466, [phone]. Information on the RMA/NPL Site as well as the Deletion Docket and the Responsiveness Summary for this partial deletion are available at EPA's Region 8 Superfund Records Center in Denver, Colorado. Documents are available for viewing by appointment from 8 a.m. to 4 p.m., Monday through Friday excluding holidays by calling [phone]. The Administrative Record for the RMA/NPL Site, which includes the Deletion Docket and Responsiveness Summary for the partial deletion of the Western Tier Parcel, is maintained at the Joint Administrative Records Document Facility, Rocky Mountain Arsenal, Building 129, Room 2024, Commerce City, Colorado 80022-1748, [phone]. Documents are available for viewing from 12 p.m. to 4 p.m., Monday through Friday or by appointment.

SUPPLEMENTARY INFORMATION:

The RMA/NPL Site is located approximately ten miles northeast of downtown Denver, Colorado and is comprised of two operable units (OU), the On-Post and Off-Post. The On-Post OU is encompassed by the boundaries of the Rocky Mountain Arsenal proper and occupies 27 square miles. The Off-Post OU addresses contamination north and northwest of the RMA proper boundaries. The Western Tier Parcel consists of 940 acres on the western perimeter of the On-Post OU of the RMA/NPL Site along Quebec Street in Commerce City, Colorado. The NPL partial deletion pertains only to the Western Tier Parcel which is a small portion of the On-Post OU. The Off-Post OU and the rest of the On-Post OU will remain on the NPL.

On October 2, 1998, EPA published a Notice of Intent for Partial Deletion (NOIDp) in the Federal Register (63 FR 53005) and local newspapers which proposed to delete the Western Tier Parcel from the RMA/NPL Site. Comments received during the public comment period primarily focused on the potential future placement of a child daycare facility at the Parcel and reiterated previous concerns that RMA, and hence the Western Tier Parcel, might be contaminated with dioxins. Based upon consideration of these concerns, EPA postponed action on the partial deletion until additional soil sampling and analysis of the Western Tier Parcel could be conducted.

The additional soil studies have been completed and, taken together with previous site-wide risk studies, address the community concerns regarding any future child daycare facility and potential dioxin contamination. These studies include the (1) Confirmation Soil Sampling Risk Report (EPA 2002a), (2) Denver Front Range Soil Dioxin Study, which consists of four separate studies including one specific to the Parcel (EPA 2001), (3) Section 9 Borrow Area Report (PMRMA 2000), and (4) Site Reconnaissance Report (EPA 2002b). Additional studies and reports developed include (1) Surface Flux Chamber Testing (CDPHE 1998), (2) Geophysical Survey on Section 9 (PMRMA 2000), (3) Vapor Pathway Analysis (EPA 1998), (4) Assessment of Residual Ecological Risk Report (PMRMA 2002), and (5) Potential Ordnance/Explosives and Recovered Chemical Warfare Materiel (OE/RCWM) Hazards Report (PMRMA 2002).

EPA proposed the partial deletion of the Western Tier Parcel on September 23, 2002, by publishing a second NOIDp in the Federal Register (67 FR 59487). Comments received during the public comment period, which ended November 22, 2002, were primarily focused on how potential contamination or munitions would be addressed if found during development of the Parcel. EPA also received nine letters of support for proceeding with the partial deletion.

In our Responsiveness Summary, EPA explained that the Tri-County Health Department (TCHD) is coordinating with Commerce City, the most likely purchaser of the Parcel, to provide personnel who will be available to brief contractors about the RMA/NPL Site history before any activity begins on the Parcel. As the local regulatory agency overseeing remediation of the RMA/NPL Site, TCHD has direct knowledge of the possible construction hazards associated with RMA lands. If any unusual material, stained soil, unusual objects, or odors are discovered, TCHD may call upon local Emergency Response resources (including Fire, Law Enforcement, and the bomb squad) or Army technicians to assist in identifying the nature of the anomaly.

The nine entities who support the partial deletion cite the thoroughness of investigations conducted by EPA, the U.S. Army, and CDPHE to ensure the Parcel is fully protective of public health and the environment. EPA agrees that the numerous studies conducted for the Parcel demonstrate that the Parcel does not present a threat to the environment or human health and it is appropriate to delete the Western Tier Parcel from the RMA/NPL Site.

EPA identifies sites that appear to present a significant risk to public health, welfare, or the environment and maintains the NPL as the list of those sites. Any site deleted from the NPL remains eligible for Fund-financed actions in the unlikely event that conditions at the site warrant such action. Section 300.425(e)(3) of the NCP states that Fund-financed actions may be taken at sites deleted from the NPL. Deletion of a site from the NPL does not affect responsible party liability or impede Agency efforts to recover costs associated with response efforts.

List of Subjects in 40 CFR Part 300 Lists of Subjects

• Environmental protection
• Air pollution control
• Chemicals
• Hazardous substances
• Hazardous waste
• Intergovernmental relations
• Penalties
• Reporting and recordkeeping requirements
• Superfund
• Water pollution control
• Water supply

Dated: January 8, 2003.

Robert E. Roberts,

Regional Administrator, Region 8.

PART 300—[AMENDED]

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, 3CFR 1991 Comp., p. 351; E.O. 12580, 52 FR 2923, 3CFR1987 Comp., p. 193.

Appendix B—[Amended]

2. Table 2 of appendix B to part 300 is amended by revising the entry for “Rocky Mountain Arsenal (USARMY)” by adding a note “P” so that it reads as follows:

Appendix B to Part 300—National Priorities List

Table 2.—Federal Facilities Section

State	Site name	City/County	Notes (a)
*         *         *         *          *         *          *
CO	Rocky Mountain Arsenal (USARMY)	Adams County	P
*         *         *         *          *         *         *
(a) * * *
* * * * * * *
P=Sites with partial deletion(s).