Contamination caused by mine tailings from as far back as 1953 at the Richardson Flat Superfund site has impacted surface water, groundwater and soil in the Silver Creek watershed. Now, through a recent agreement between the U.S. Environmental Protection Agency and United Park City Mines (UPCM), over 2,700 acres affected by old mining operations will be cleaned up.
The well-known Richardson Flat tailings site encompasses 160 acres near US 40 northeast of Park City. The most recent tailings disposal at the site occurred between 1975 and 1981 when UPCM leased mining operations to Noranda Mining and Park City Ventures. UPCM is now owned by Talisker Land Holdings.
According to the EPA, the site contains many hazardous materials such as arsenic, cadmium, copper, lead, mercury, silver and zinc. In 1989, the EPA and the State of Utah detected mine tailings sinking into a diversion ditch and the nearby Silver Creek.
Under the auspices of the EPA, UPCM will be addressing mine waste at the lower sections of Silver Creek north and east of US 40 as well as along Silver Creek and its floodplain just east of Park City.
As per an Administrative Settlement Agreement and Order on Consent issued by the EPA to Summit County on March 6, remediation plans for the 2,700 acres are set forth, naming UPCM as the responsible party for cleanup. Many state and federal agencies will be involved in the process.
Summit County Manager Bob Jasper is pleased that the cleanup process is moving along and applauded the remediation plan.
"Eventually, they will clean up Richardson Flat. [In the meantime], those mountains will increase and grow. Contaminated soils will be taken there," Jasper said. "Whether that's the best place or there is a more efficient place is for public comment."
Jasper said the EPA's vision is to make Silver Creek (known as Poison Creek within Park City) a Blue Ribbon trout stream, conducting revegetation efforts along with remediation. As part of this process, he said cranes would be in the Silver Creek streambed near Prospector every day doing work, which the EPA says could take eight years.
"They'll use heavy equipment, hauling dirt for a number of years. Eight years is optimistic. At least 10 years [I think] it will take them," Jasper said.
Jasper added that Park City Municipal Corporation has agreed to remediate Prospector Drain, which the EPA maintains is polluting Silver Creek. Cleanup and restoration efforts will take place along six miles of the Silver Creek drainage, the EPA says.
The county will not know how the nearby Rail Trail will be impacted by remediation efforts, but county spokesperson Julie Booth said it is the county's understanding that the trail will remain open with intermittent closings for some areas. More details will emerge when the county receives the EPA's Engineering Evaluation/Cost Analysis.
Summit County Attorney David Brickey said the county has been concerned about the contamination of the Lower Silver Creek area since 2008, when the Lower Silver Creek Soils Temporary Overlay Zone was formed to inform property owners of contaminated soils and water and to mandate soils studies.
Jasper said any developer looking to build in the future along the US 40 corridor near Richardson Flat will need to work with Talisker. He also encourages the public to provide comments on the process.
"[The problem] starts back in the mining era when we didn't regulate. The goal [of the project] is a good goal. It will require a lot of money and lot of disruption," Jasper said. "People should participate in the federal process."
For more information on the Richardson Flat Superfund site, visit www2.epa.gov/region8/Richardson-flat-tailings/