Arizona Army National Guard Camp Navajo

Arizona Army National Guard Camp Navajo: Page 2 of 2

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The installation operated as a reserve supply depot for the receipt, shipping, storage, surveillance, minor maintenance and demilitarization of ammunition/explosives and assigned commodities. The OB/OD Area was formerly used for demilitarization and land disposal of obsolete and unserviceable conventional ammunition, explosives, and limited chemical warfare agents.

Operational control of the base was transferred in 1982 under an intra-State support agreement from the Secretary of the ARNG. After the transfer, the missions for the ARNG were training, continuing depot activities and facilities maintenance. In 1993, operational control was again transferred under the Base Realignment and Closure Act of 1988 (BRAC) to the ARNG, and the name was changed to Camp Navajo. The installation continued as a major training site, and also performing depot-level storage service for the Department of Defense (DoD), other government, and civilian entities. As a condition of the transfer, the Army maintained responsibility for cleanup activities at the facility. Demilitarization activities ceased in 1994 in connection with the closure of Camp Navajo under BRAC.

In 2002, a Stakeholder’s Advisory Group (SAG) was formed to assist the ARNG with stakeholder concerns. The SAG consisted of members from agencies such as the U.S. Fish and Wildlife Service, ADEQ, the Arizona Game and Fish Department, the U.S. Forest Service, the ARNG, as well as three community members. The SAG completed its task by 2011 and no longer meets.

Camp Navajo did not qualify for inclusion on the U.S. Environmental Protection Agency's (EPA) National Priorities List, but regulatory oversight is provided by ADEQ under the DoD’s Installation Restoration Program (IRP) and Resource Conservation and Recovery Act (RCRA). 

Over the years several studies, investigations and removal actions have occurred at Camp Navajo, including numerous munitions-related sites, resulting in either no further response action, long-term management (LTM), land use controls (LUCs) or post-closure care (PCC). Currently there are five sites that were placed into LTM under the IRP since at least 2005, and subsequently 2015 and one PCC site under RCRA. The IRP sites consists of Navajo Army Depot (NAAD)-01, NAAD-11B, NAAD-20, NAAD-40, and NAAD-43. The PCC site includes the former OB/OD Area designated as the Munitions Response Work Area (MRWA)-02, formerly identified as NAAD-02.

As part of the IRP, five-year reports are conducted to ensure the selected remedies remain protective to human health and the environment. The third Five-Year Review (FYR) was completed in 2020 and concluded that the site remedy is protective of public health and the environment.

The former construction debris landfill (NAAD-43) is in evaluation for closure after buried materials and contaminated soil were excavated from the site and confirmation soil samples were analyzed for a site-specific risk assessment.

A Preliminary Assessment/Site Inspection (PA/SI) Work Plan was approved in April 2020 for three sites identified as NAAD-25, NAAD-26, and NAAD-39 under the hazardous waste post-closure permit. It was determined to investigate these sites under CERCLA and the PA/SI report was finalized April 2021.

The National Guard initiated a focused investigation for per- and polyfluoroalkyl substances (PFAS) at Camp Navajo. The focused investigation’s goal is to identify if PFAS contamination is present on the installation by sampling and analyzing soil and groundwater in areas of known PFAS use or highly probable areas of concern. The SI work plan was finalized in April 2021.

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Five IRP sites continue to be monitored and reported annually for groundwater and LUCs. One of the five IRP sites, NAAD-43, is in evaluation for closure. Groundwater monitoring results from NAAD-11B will be used to support characterization and closure of this site. Results from groundwater monitoring at NAAD-40 will be used for ongoing compliance monitoring. No groundwater samples are collected at NAAD-01, NAAD-20, or NAAD-43. The LTM activities required at these sites consist of inspections and maintenance with respect to specific criteria used to determine compliance of the implemented remedies (i.e. LUCs). The third FYR Report was completed in September 2020. Excavation and sampling activities concluded at NAAD-43 in October 2020. ADEQ concurred with the technical memorandum proposing site closure at NAAD-43 in May 2021. An After Action Report submittal is forthcoming from the installation following backfill and surface grade activities. The PA/SI was finalized in April 2021 for NAAD-25, -26, and -39. The installation informed ADEQ that a supplemental SI will be performed during Spring 2022 for the three NAAD sites, in order to verify the SI results and appropriate funding for any further recommended work.

The focused PFAS SI Work Plan was finalized April 2021. Upcoming events include field work, project planning meetings, and review of the draft SI Report in Winter 2021.

A PA/SI Work Plan was approved in April 2020 for three sites identified as NAAD-25, NAAD-26, and NAAD-39 under the hazardous waste post-closure permit. It was determined to investigate these sites under CERCLA and sampling activities began in May 2020.

NGB has plans to investigate the installation for per- and polyfluoroalkyl substances (PFAS).

Munitions and munitions constituents remain in place at MRWA-02. A hazardous waste post-closure permit was issued for MRWA-02 on January 27, 2017. The permit requires long-term maintenance activities including inspections and groundwater monitoring.

This Federal Department of Defense (DOD) Site is also listed as hazardous waste site on My Community | View Hazardous Waste Sites Page >