From 1963 to 1999, a vanadium production plant operated on a 158-acre site in Soda Springs, Idaho. Unlined ponds stored industrial wastewater and tailings, and those ponds leaked hazardous chemicals into groundwater and surface water. EPA added the site to the National Priorities List in October 1989. The Greenfield Environmental Multistate Trust, LLC has managed cleanup actions since 2011 under EPA oversight and now owns and maintains the property on behalf of the United States and the State of Idaho.
Nine contaminants require cleanup at this site. Arsenic, tributyl phosphate, manganese, molybdenum, and vanadium were found in groundwater, liquid waste, and solid waste. Lithium and total petroleum hydrocarbons (TPH) were detected in groundwater and liquid waste. EPA identified these contaminants because they pose an unacceptable risk to human health or the environment based on the amounts present and potential exposure pathways.
Significant cleanup work has already taken place. About 350,000 cubic yards of waste were removed from a pond in 2018. The site has also been demolished and regraded. EPA completed a Five-Year Review in September 2022 and found that the remedy is currently short-term protective because there is no exposure to contaminated groundwater or soil. Human exposure and groundwater migration are both under control, with no unacceptable discharge to surface water. In November 2023, EPA issued a Record of Decision Amendment selecting a revised remedy. That remedy includes land use restrictions for soil, in-situ anaerobic bioremediation, groundwater extraction via vertical wells, in-situ flushing, onsite treatment, hydraulic containment, and monitored natural attenuation for off-site areas. Remedial design work began in November 2023 and is estimated to conclude between September and November 2026, when final construction is expected to begin. The next Five-Year Review is estimated for September through November 2027.
Community members can get involved in several ways. EPA held a public meeting and comment period after issuing a Proposed Plan in March 2023. Residents with questions or concerns about cleanup can contact the EPA Remedial Project Manager or the Community Involvement Coordinator. A Community Involvement Plan has additional details on ways to stay informed. Site records are also available for public review at the Soda Springs Public Library, 149 South Main Street, open Monday through Thursday from 10:00 am to 8:00 pm and Friday from 10:00 am to 5:00 pm.
