Two historic smelters built around 1870 near the mouth of Little Cottonwood Canyon, about 15 miles southeast of Salt Lake City, left soils laced with lead and arsenic. The site was added to the National Priorities List in 2003 and deleted on July 27, 2018, after cleanup construction was finished. Operation and maintenance continue today.
Lead and arsenic are the contaminants of concern. Both metals were found in soil across three cleanup areas: residential properties, commercial and undeveloped land near Little Cotton Creek, and agricultural land near the Flagstaff Smelter. EPA determined the amounts present, combined with how people could come into contact with them, posed an unacceptable risk to human health. People can be exposed by eating, breathing, or touching contaminated soil or household dust. Lead is a particular concern for children under 7 and pregnant or nursing women, and EPA recommends annual blood lead testing for young children at properties where soil has not been replaced.
Cleanup was split into three operable units. Residential soils cleanup ran from 2004 to 2008 and removed about 33,000 cubic yards of contaminated material. Non-residential land near Little Cotton Creek was cleaned up in 2011, with about 7,100 tons of soil excavated and disposed of off-site, and that unit has been in operation and maintenance since 2013. Agricultural land near the Flagstaff Smelter was addressed in 2006, with roughly 77,000 tons of contaminated soil removed. The most recent five-year review was completed in August 2022, and the next is estimated between August and October 2027.
As of October 2025, EPA is reviewing how a new Lead Directive affects this site. The directive updates the blood lead level of concern and the soil screening level used to guide cleanups. Groundwater migration is under control, but human exposure status currently shows insufficient data to confirm whether all unacceptable exposure pathways have been eliminated. The site has not yet achieved sitewide readiness for anticipated reuse. The area is actively used as a residential and commercial zone that includes a restaurant and a watershed protection zone.
Community members can contact the EPA Community Involvement Coordinator, Ashlin Brooks, or the EPA Remedial Project Manager, David Connolly, with questions. Utah Department of Environmental Quality staff, including state Project Manager Maureen Petit and Community Involvement Specialist Dave Allison, are also available. Site records can be reviewed at the Sandy Library, the Utah Department of Environmental Quality office in Salt Lake City, or the EPA Superfund Records Center in Denver.
