Awards: Grand Award for Engineering Excellence from the American Council of Engineering Companies (ACEC), Pacific Northwest District Nominee for ASCE’s Outstanding Civil Engineering Achievement Award 

The Warm Springs Ponds near Anaconda, Montana, were built between 1911 and 1959 on Silver Bow Creek to trap and store residual ore processing wastes (tailings) generated at the adjacent mills. The ponds also intercepted contaminated sediments and water of Silver Bow Creek draining from the Butte mining/milling facilities 20 miles upstream. The 4.6-square-mile site contained an estimated 19 million cubic yards of metals-impacted materials within the flood plain. The project remediated the Ponds System to treat incoming water high in copper and zinc resulting from historic mine tailings deposited in upstream reaches of Silver Bow Creek. 

Project Accomplishments

• To eliminate the migration of heavy metals from the site, lime is metered into Silver Bow Creek at the intake of the Ponds (Lime Treatment Plant) in what is believed to be the largest capacity facility  of its kind in the world
• The innovative design solution consolidates, contains and treats on-site all metal-bearing tailings, precipitates (sludge) and impacted soils
• Improved water quality within the Ponds System and Clarks Fork River below the Ponds has prevented the frequent fish kills that occurred prior to the project
• The project transformed the country’s largest Superfund site into a premier habitat for waterfowl, fish and other wildlife