The Uintah Mining District Site is located in the Silver Creek and Mcloed Creek watersheds in and around Park City in Summit County, Utah. Mining began in the area around 1869 and the mining district produced substantial quantities of ore between 1875 and 1982. Mining operations involved tunnels to extract the ore, tramways and railroads to transport ore, and milling facilities to process the ore. As a result of these operations, tailings and other mine waste containing lead and other heavy metals were deposited throughout the area.
EPA’s removal evaluation found contaminated soil eroding off of several remnant waste piles at the Site and being deposited further downstream. These waste piles are considered source areas of contamination. In addition, EPA found contaminated soil near the surface at the Treasure Mountain Junior High School which includes the adjacent recreation fields.
EPA completed a time-critical removal action at the Treasure Mountain Junior High School and adjacent recreation fields in 2016. This removal action removed contaminated soil from the surface and restored the property to its full use.
In 2017, United Park City Mines (UPCM), the owner of the source area properties, completed construction of erosion control features in Ontario Canyon, Empire Canyon, Upper Woodside Gulch and Thaynes Canyon in accordance with an Administrative Order on Consent. UPCM has failed to completely address erosion issues that occur during snowmelt runoff at Treasure Hollow and has not implemented an effective long-term plan to maintain erosion control in the source areas.
On August 30, 2019, EPA took over Post-Removal Site Control work from UPCM in accordance with the Administrative Order on Consent. EPA addressed continuing erosion at Treasure Hollow before adverse winter weather conditions prevented construction access to the location. EPA is currently monitoring Site conditions and performing minor repairs as needed.
