Ogden Defense Depot sits in Weber County, Utah, and operated as a military storage and distribution facility starting in 1941. The Army stored medical, industrial, electronics, food, clothing, and petroleum products there. Past waste disposal practices, including dumping liquid wastes, burning solvents in pits, and burying waste in trenches, left soil and groundwater contaminated with hazardous chemicals. EPA added the site to the National Priorities List in 1987, making it a federal Superfund site.
The site has 53 confirmed contaminants of concern spread across four burial sites and a French drain area. Soil contains metals such as arsenic, lead, cadmium, nickel, zinc, and mercury, along with organic compounds including benzene, trichloroethene, vinyl chloride, PCBs (polychlorinated biphenyls), pesticides like chlordane and DDT, and petroleum hydrocarbons. Groundwater holds volatile organic compounds including trichloroethene, tetrachloroethene, benzene, and chloroform. Dioxin appears in both soil and groundwater at burial sites 1 and 4. Lewisite and phosgene are found only in burial site 3 soil, and chlordane and tetrachloroethene are found only in the French drain area.
The Army serves as the lead cleanup agency under a Federal Facility Agreement signed in 1989. Cleanup was organized into four operable units. Work began in 1993 and included excavating contaminated soil, incinerating contaminated liquids, injecting soybean oil to encourage biological breakdown of contaminants, and extracting and treating groundwater. One groundwater treatment system was shut down in 2023 while the other remains operational. In 2025, the Army added an institutional control requiring a vapor barrier or a protective study before any new building goes up over contaminated groundwater plumes, addressing vapor intrusion identified as a concern back in 2018.
EPA assessments confirm that human exposure is currently under control across the entire site, with no unacceptable exposure pathways. Groundwater contamination is stabilized with no unacceptable discharge to surface water, and monitoring continues. Physical cleanup construction is complete sitewide, and the site achieved ready-for-anticipated-reuse status in June 2006. Most of the former depot has been redeveloped into Business Depot Ogden, a business park leasing space to about 60 companies. The only areas still awaiting redevelopment are where groundwater plumes remain in two operable units. The most recent five-year review was completed in September 2022, with the next expected between September and November 2027.
Community members with questions can contact the EPA Remedial Project Manager. For state-related questions, contact the Utah Department of Environmental Quality.
