The Upper Clark Fork Basin in Montana, which stretches 120 miles from Butte to Missoula, was heavily impacted by mine wastes from copper mining and smelting practices that took place from about 1884 through 1980, when the smelter closed. Over time and through flooding, this waste washed down surrounding creeks and the Clark Fork River and settled throughout the floodplain. It is now the site of the largest Superfund complex in the country. TREC, a Woodard & Curran company, has been actively involved with successful remediation activities at this Superfund site for more than 20 years.
PROTECTING ESSENTIAL COMMUNITY INFRASTRUCTURE
In one such project, TREC led the effort for a confidential client to develop effective strategies that address both land and water quality issues at Warm Springs Creek, which feeds into the headwaters of the Clark Fork River. The first phase of the project focuses on a section of Warm Springs Creek that threatened the Anaconda Deer-Lodge Airport during high-flow events. To protect this infrastructure, the restoration design includes enhanced floodplain storage, improving conveyance through a half-mile channel reach, and stabilization of stream banks using bioengineered bank treatments, all of which combine to mitigate overland flooding while maintaining natural stream processes.
INGENUITY AND EXPERTISE EARNS RESPECT
The second phase of the remediation project is substantial, consisting of removing contaminated floodplain and stream bank soils from three miles of stream that contained entrenched mine tailings. Approximately, 70,000 cubic yards of contaminated soil is projected to be removed and 15,000 linear feet of bioengineered streambanks is projected to be constructed. TREC developed channel restoration and stabilization methods using a stable reference reach, which emulates natural conditions and materials found within the system. Hydrologic and hydraulic calculations were used to verify stream material gradations and localized scour/shear stress. The firm’s ingenuity and general expertise has earned the respect of the client, the Environmental Protection Agency, and the Montana Department of Environmental Quality agents involved.