EPA Superfund Site

UTAH POWER & LIGHT/AMERICAN BARREL CO.

UT | EPA ID UTD980667240

About this site’s exposure pathways: As of September 2025, the Utah Power and Light⁄American Barrel Superfund site is considered Insufficient Data to make a Human Exposure evaluation (HEID). The Utah Power and Light⁄American Barrel Superfund site was evaluated in 2021 for its fifth Five-Year Review (FYR), and recommendations from that review indicate that there is insufficient data to make a Human Exposure determination.
EPA uses this Human Exposure status when there is a lack of evidence to suggest that actual or reasonably anticipated human exposures are occurring, and that those exposures are above acceptable risk-based levels. A vapor intrusion investigation for the North Sixth Apartments was recommended during the 2016 fourth FYR, based on information identified during 2011 vapor intrusion sampling. In August 2018, PacifiCorp submitted a Response to Recommendation⁄Follow-up Action for Indoor Air Sampling and a Vapor Intrusion Investigation from the Fourth Five-Year Review. The Johnson and Ettinger model was used in this evaluation to determine if the soil vapor posed a potential risk to persons inside the North Sixth Apartments. Although residential units are not located on the first floor, to be conservative the Johnson and Ettinger model was run for a potential residential exposure. The model results indicated that the concentrations detected in the soil-gas would not translate into a residential exposure above target levels. The report also identified difficulties in conducting vapor intrusion sampling due to elevated background benzene concentrations that would be present given the buildings urban location and the thickness of the building foundation (3 feet thick) that would prohibit sub-slab sampling. After reviewing the document and conclusions of PacifiCorp’s August 2018 response, the EPA and Utah Department of Environmental Quality (UDEQ) determined that the Johnson and Ettinger modeling conducted would not be sufficient to determine risk posed by the vapor intrusion pathway. The EPA and UDEQ required a comprehensive vapor intrusion investigation, including indoor air sampling, to evaluate the vapor intrusion pathway for the North Sixth Apartments. In April of 2022, PacifiCorp performed a vapor intrusion investigation, but that test was inconclusive. A second round of testing was completed in 2023, which EPA is currently in the process of evaluating.
EPA and UDEQ currently anticipate that there will be sufficient data to make a Human Exposure determination by December 2025. This date is anticipated because it will provide the time analyze the results from a comprehensive vapor intrusion investigation. Note that this does not necessarily mean that unacceptable exposures are occurring. If you live near this site and have questions, please contact EPA or UDEQ at one of the contacts on the site web page.