EPA Superfund Site

VASQUEZ BOULEVARD AND I-70

CO | EPA ID CO0002259588

About this site’s exposure pathways: As of September 2025, Vasquez Boulevard and I-70 Superfund site is considered Current Human Exposure Not Under Control (HENC). Although residential soil investigations and cleanups at Operable Unit (OU) 1 (Residential Soils) were completed in 2018 for properties exceeding 400 mg⁄kg lead or 70 mg⁄kg of arsenic, and institutional controls are in place, the EPA has provided an Updated Soil Lead Guidance for CERCLA sites and RCRA Corrective Action Facilities (Updated Lead Guidance) on January 17, 2024. This has lowered the recommended regional screening level for lead-contaminated soil to 200 mg⁄kg for residential soil-lead sites and the EPA is evaluating how this change may impact the cleanups that were completed and determine if additional investigation and⁄or cleanup is needed. The EPA site team will communicate with residents affected by this guidance about the specific next steps the Agency will take in their community.
The remedial investigations at OU2 (the former Omaha & Grant Smelter) and OU3 (the former Argo Smelter) are ongoing, but there are known elevated levels of contaminants in groundwater and sub-surface soils in these areas. The main contaminants of concern at OU2 and OU3 are heavy metals including lead and arsenic. In OU2, land use determinations, and therefore potential human health exposures, are in flux due to unknown future development activities. In OU3, the groundwater concentrations of arsenic, lead and cadmium are above the drinking water standards. This exposure pathway is considered unacceptable based on EPA risk-based criteria because. Although the groundwater is not currently used for drinking, there are no institutional controls to prevent contact or use with contaminated groundwater.
To date, the planned activities to address these pathways are to begin evaluating existing site data and data gaps to determine the extent of OU1 soils that may present current and future-potential exposure risk to sensitive populations. EPA plans to review and finalize the Remedial Investigation at OU2. At OU3, the next step is to continue Remedial investigation activities, and then develop a Feasibility Study that will evaluate possible alternatives to clean up OU3.
If you are potentially impacted by risks inherent at this site, you can contact the Community Involvement Coordinator for details. EPA currently anticipates that human exposure will be under control by June 2030, because it anticipates receiving funding and completing associated studies and cleanups by then.