Steven Way, Flood Response Operations Chief, inspects, with
ERRS personnel, repairs to the Streamside Tailings at Bueno
Mill & Mine. The 2005 remedy held, but floodwaters heavily eroded
embankments and damaged the concrete armoring.
2013 Flooding Event
As a result of a 500-year flash flood in Boulder County that occurred September 2013, a time-critical response was initiiated to prevent a potential catastrophic release of mine tailings laden with heavy metals into James Creek and below into the town of Jamestown, Colorado.
An original 2005 EPA Removal Action at the Bueno Mill & Mine capped the mine tailings along James Creek and required riprap and the armoring of a section of the creek with a concrete fabric structure to stabilize the embankment from potential erosion. The 2005 remedy held, preventing the release of an estimated 50,000 cubic yards of tailings, but the 2013 floodwaters scoured James Creek, causing some slippage to the structure and erosion above and behind the riprap and filled the stream with root wads and debris.
2005 Removal Action
The U.S. EPA Region 8 – Ecosystems Program and the USDA Forest Service initiated a watershed survey in the Lefthand Creek basin, which identified several sources of heavy metals loadings to James Creek and Little James Creek surface water. In addition, the Jamestown water treatment plant has reported impacts to the water supply during run-off events. USDA-FS identified this property as priority within the Lefthand Watershed for a possible removal action.
Subsequently, in May 2005 a Removal Assessment was initiated with a sampling program to characterize two mill tailings deposits. Concentrations of lead in the Bueno Tailings range as high as 3,600 mg/kg (XRF data) and average approximately 2,500 mg/kg. The Streamside Tailings deposit lead levels are as high as 31,500 mg/kg, which was found in one sample. Other lead values are near 6,500 mg/kg and average approximately 4,000 mg/kg. Other hazardous substances present include arsenic, copper and zinc. The Bueno and Streamside Tailings deposits combined are estimated to contain 50,000 cubic yards. A removal action was started in 2005.
See Site Youtube video at: EPA Emergency Response: Colorado Floods 2013 - Bueno Mill and Mine
