U.S. DEPARTMENT OF THE INTERIORBUREAU OF LAND MANAGEMENT
|Salmon Field Office|
The Champagne Creek Restoration Project is located about 17 miles west of Arco, Idaho.
Mining activity began in this area in 1883 with the discovery of silver ores in the Champagne Creek region. These early operations only mined the easily accessible, shallow, oxidized silver ores. Typically these ores were mined from depths not exceeding 75 feet below the surface. Although the area was a very important silver producer in Idaho from 1884 to 1886, by 1887 most of the early operations had ceased.
This area remained relatively inactive until the late 1920s when the possibility of using the deeper base-metal sulfides as ores of lead and zinc regained interest in this area. At this time, Hornsilver Consolidated Mines Company undertook a major underground exploration program. A key aspect of the exploration involved driving a crosscut tunnel, hoping to intersect the Last Chance vein 450 feet below the surface. This crosscut was known as the Moran Tunnel. Because it penetrated the vein at a barren point, the operations were soon terminated.
The Hornsilver Mine was reopened from 1937 to 1941 with a total production of 1,095 tons of ore. In 1941 the Era Mining and Development Company acquired control of many claims in the Champagne Creek region and mined sulfide ore from the Last Chance vein via the Moran Tunnel from 1941 to 1946. As with all of the other mines that operated in this district, the ore was shipped to Salt Lake City to be processed. Therefore, tailings at these mine sites were not an issue.
Because of the negative impacts to Champagne Creek’s water quality, this restoration project was a deemed a priority. Each year, the Moran Tunnel flowed low-pH, high metal-laden, waters into Champagne Creek, impacting aquatic life and vegetation. Our goal was to remove highly metal-contaminated soils from the Champagne Creek drainage and enhance the natural wetland’s ability to continue to treat the metals in the environment.
Metals-contaminated soil was removed where disturbance to the existing riparian vegetation was minimal. Where possible, contaminated soils were replaced on the floodplain with clean fill. The wetland was enhanced by rebuilding a large beaver dam and outlet and adding more road base on the county road. An exclosure fence was installed to allow for more rapid riparian recovery.
Analysis of the water quality data indicated that high concentrations of iron was interfering with the effectiveness of the bioreactor berms in removing zinc and copper and buffering the pH level. An anaerobic tank was added below Moran Tunnel to remediate the problem.
Over time we suspect that the treatment system will stabilize. The reductions in metal concentrations and an increase in pH levels will allow for gradual recovery and restoration from past mining impacts at Champagne Creek.
For additional information regarding this project, contact the area specialist or call the BLM Upper Snake Field Office at (208) 524-7500.
Upper Snake Field Office | 1405 Hollipark Drive | Idaho Falls, ID 83401