EPA Superfund Site

KERR-MCGEE CHEMICAL CORP. (SODA SPRINGS PLANT)

ID | EPA ID IDD041310707

About this site’s exposure pathways: As of October 2024, the Kerr-McGee Chemical Corp. (Soda Springs Plant) Superfund site is considered “Current Human Exposure Not Under Control” (HENC). Offsite groundwater is a direct contact (ingestion) risk to current and future residents because vanadium and molybdenum are higher than their EPA risk-based criteria, regional screening levels of 86 ug/L and 100 ug/L, respectively. Historically residents have randomly installed groundwater wells. There are currently no institutional controls in place to prevent future well drilling.
A Record of Decision Amendment was finalized in November 2023 to establish institutional controls that will be employed in conjunction with active groundwater treatment to reduce contaminant concentrations in groundwater and return the aquifer to beneficial reuse within a reasonable timeframe. If you are impacted by risk inherent at this site, contact the Remedial Project Manager for information. Based on information obtained from the 2019 Supplemental Remedial Investigation (SRI) Report, the Baseline Human Health Risk Assessment (BHHRA) and the Screening-Level Ecological Risk Assessment (SCLERA), there is no current human health or environmental exposure to contamination on or off-site. The Multistate Trust has conducted a domestic well survey and no private wells have been identified within the area of groundwater contamination and has confirmed through communications with the city that clean water provided by the city to its residents, and to select locations outside of city limits, is available to all properties that are located geographically within the area of site-related groundwater contamination.
EPA currently anticipates that human exposure will be under control by September 2025 because the 2024 long-term monitoring data will be available to confirm the area of site-related groundwater contamination remains within its current footprint. On-site institutional controls are planned and will be implemented. The Multistate Trust owns the property and any land use change must be approved by EPA and Idaho Department of Environmental Quality (IDEQ). Off-site groundwater institutional controls are also planned in the form of an Area of Drilling Concern through Idaho Department of Water Resources (IDWR).