Tooele Army Depot (North Area)

Overview

Tooele Army Depot (North Area) sits in Tooele, Utah, and has been contaminated since the 1940s from ammunition storage, equipment repair, and other military operations. It was added to the National Priorities List in 1990 and is divided into 16 operable units, each targeting a specific area or contamination type. The site is still working through active cleanup and has not yet reached construction completion.

Contamination affects both soil and groundwater. Metals found at the site include lead, mercury, cadmium, chromium, arsenic, and several others. Organic compounds include polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons, the pesticide chlordane, and explosive-related chemicals such as RDX and 2,4-dinitrotoluene. Unexploded ordnance is also a concern in solid waste areas. The greatest health risk comes from ingesting or making direct contact with contaminated soil or groundwater. Groundwater contamination is not yet stabilized, and human exposure data are listed as insufficient to confirm whether exposures are fully controlled.

The U.S. Army leads cleanup with EPA regulatory oversight and state approval from Utah. Completed actions include excavating and disposing of contaminated soil, stabilizing lead-contaminated soil on site, removing explosives from a trench, and closing sumps and waste-disposal systems. A groundwater treatment facility was found ineffective and decommissioned in 2016 and 2017. Researchers are now running a lab-scale study to see if natural processes can break down groundwater contaminants over time, which could support a monitored natural attenuation remedy. The Army is also preparing a Record of Decision for Operable Unit 15, covering five munitions areas. Several individual operable units have finished remedial action, with the most recent, the MMRP Sites area, completing its initial phase in June 2024. The most recent five-year review, completed May 2, 2023, found that current remedies protect human health and the environment in the short term.

Final remedial action across the full site is estimated to begin between April and June 2027. The site has been redeveloped in parts, with transferred land now hosting an industrial park and renewable energy projects including wind turbines and a solar array.

Community members can attend Tooele Restoration Advisory Board meetings, held twice yearly in spring and fall. Meetings are announced in the local newspaper and are open to the public. Site records are available at Tooele City Public Library, Grantsville Public Library, the depot's Environmental Management Division office, and the University of Utah's Special Collections Department. The EPA Remedial Project Manager and Community Involvement Coordinator can direct residents to additional documents.