Location

The Arizona Army National Guard (ARNG) Fort Tuthill Small Arms Range Munitions Response Site (MRS) is located approximately 5 miles south of Flagstaff, Coconino County, Arizona. The Range is located on County property encompassing 100 acres.

Fort Tuthill was utilized for artillery training of .30 and .50 caliber water-cooled machine guns, Browning Automatic Rifles, hand grenades, and bazooka rounds from 1928 to 1955.

Contaminants of Concern

The contaminants of concern (COCs) includes munitions and explosives of concern (MEC) and associated munitions constituents (MC). COCs at the site may change as new data become available.

Public Health Impact

Military munition and unexploded ordinance (UXO) debris may pose an explosive hazard. Discovery of these materials should be reported to the local law enforcement authorities and left untouched.

Action Taken

The ARNG completed a site investigation of Fort Tuthill Small Arms Range in 2012. No evidence of MEC or MC were discovered during the investigation and ARNG requested closure of the site with No Further Action (NFA) required. The NFA determination was concurred with and the site was closed in 2014.

In 2017, MEC was discovered during construction activities within the Fort Tuthill County Park. The live round was detonated in place by Explosive Ordinance Disposal technicians from Luke Air Force Base. This discovery initiated the reopening of the site for further investigation.

Status

ARNG and ADEQ finalize the Remedial Investigation (RI) Quality Assurance Project Plan (QAPP) in September 2020. The RI field work was completed in November 2020. Currently the RI report is expected for ADEQ’s review in summer 2021.