Homes and businesses safe according to final report of the Salt lake County Kennecott Tailings Impoundment Committee

In the event of Utah’s “Big One” Magna residents and businesses would be safe from a run off of silt from Kennecott.

By Kimberly Thomas
News Editor

The Salt Lake County Kennecott Tailings Impoundment Committee released their final report on the seismic stability and run out analysis of the South East corner of the Utah Kennecott Copper Tailings Impoundment. The final report brings good news to residents and property owners north of 2700 South and west of 8000 West. The report states that there will be no runoff onto businesses or residential property. However, run out from the impoundment would extend onto Highway 201 and slightly onto the golf course adjacent to Highway 201 (slightly being 300 feet).
The impoundment consists of silt and mining waste. What would happen to the impoundment’s stability in the event of major seismic activity raised concerns that lead to the formation of the Salt Lake County Kennecott Tailings Impoundment Committee and the release of this report.
The report reflects that the embankment could fail in the event of a 6.5 earthquake; however, the embankment would not start to run off for several minutes or hours. Seismic sensors have been placed in the impoundment. In the event that the seismic sensors go off signs off of Highway 201 will begin flashing, warning drivers not to enter Highway 201. The Impoundment Committee says these signs will “allow sufficient time for traffic to divert to alternate routes.”
The report also states that there will be no danger of a run off by the year 2018 because of dewatering efforts within the impoundment. These dewatering efforts will gradually improve stability in the impoundment.
Co-Chair for the Impoundment Committee Michael Jensen stated, “The study shows that no residential structures including those close to the embankment, are in danger of run out from the embankment. Previous analysis performed to predict the post-earthquake stability of the southeast corner of the facility was also found to be appropriate methodology.” The study was done by the independent geotechnical engineering firm: Tetra Tech, Inc.
Businesses and residential properties that were believed to be in danger will be receiving a letter outlining the committee’s findings. The Impoundment Committee would like to extend special thanks to their volunteer Geotechnical experts: John Wallace from GeoEnvironmental Services, Inc., and Jack Hamilton from the University of Utah. A copy of the final report can be found at www.magnatailingsstudy.slco.org.