Silver Bow Creek, a 26-mile stream originating near Butte, Montana, has a legacy of historic mining activity. Since the late 1800s, mining operations in and around Butte have deposited waste materials near the creek and surrounding areas. Additionally, smelters and mills releasing airborne emissions containing arsenic and heavy metals further contributed to environmental contamination. These practices resulted in the presence of heavy metals in the soil, groundwater, and surface water.
In 1982, the Environmental Protection Agency (EPA) proposed adding Silver Bow Creek to the National Priorities List (NPL) due to the identified contamination. The designation was finalized in 1983. The Butte Area was subsequently added to the Silver Bow Creek Superfund site in 1987.
Warm Springs Ponds is at the lower end of Silver Bow Creek. This 2,600-acre area consists of three settling ponds and multiple wildlife ponds. The ponds currently exist as an active treatment facility and a rich habitat for a large number of waterfowl and mammals.
Trihydro’s predecessor, Alloy Group’s Engineering and Consulting Division (acquired in 2024), was contracted by the client to provide technical support for the Warm Springs Pond Operable Unit 4 (OU4). OU4 includes a lime addition/precipitation water treatment system and a dam facility that actively treats the flow of Silver Bow Creek prior to its confluence with Warm Springs Creek, which forms the start of the Clark Fork River. Under CERCLA, an interim Remedial Action plan was created in the 1990s. The client's goal is to work with the EPA to arrive at a final plan for the site's future management.
Trihydro’s responsibilities on the project include assisting with agency communications and developing strategies on numerous issues, including water treatment optimization, compliance requirements, and site operations. Additionally, Trihydro reviews all data from surface water and groundwater and interprets trends. They use laboratory results, microscopy and microanalysis, and modeling software to assess the current conditions and potential impacts of changes on the site and upstream of the site. This information guides the identification of data gaps, the development of a Conceptual Site Model, and the future management of the ponds.
Past responsibilities also included managing dam safety monitoring activities, developing a water treatment operational approach and system troubleshooting, monitoring real-time data to identify treatment system upsets, and managing the construction of a dam breach monitoring and alarm system.