Work continues around Silver Valley superfund site

This was a busy year for area agencies working within and around the Bunker Hill Superfund Site.  

Progress was made on projects in both Shoshone and Kootenai counties, as crews continued to undo the damage of years of mining.

A significant amount of work was completed north of Wallace, including the East Fork of Ninemile Creek and Canyon Creek.  

In Ninemile Creek, crews removed over 200,000 cubic yards of mine waste from the Dayrock and Tamarack complexes. This waste material was used to fill the East Fork Ninemile Waste Consolidation Area, with the remaining waste being taken to the Canton Creek Repository. 

Once the waste materials were removed, 2,300 linear feet of stream channel and riparian areas were rebuilt at the Dayrock Complex. 1,700 linear feet of tributary drainage was reconstructed at the Tamarack Complex. 

According to Sharon Bosley, executive director of the Basin Environmental Improvement Project Commission, both projects were priorities for the Coeur d’Alene Work Trust to complete this year.  

The second of four years of planned work near Canyon Creek was completed this year, as work crews removed 23,000 cubic yards of contaminated materials from the Hecla Star Complex near Burke.  

Once the waste materials were removed, crews installed 1,100 feet of concrete box culvert, which allows Canyon Creek to flow through and under a portion of the site.  

Additional work was completed along the South Fork of the Coeur d’Alene River, where 18 historic mine and mill sites were reviewed and monitored. The sites span much of the river’s upper reach areas, including several locations between Mullan and Wallace.  

In Kootenai County, extensive work has been completed within the Cataldo Reach, where riverbank and riverbed sampling has shown differing levels of erosion within the Lower Coeur D’Alene Basin River Channel. Over the next two years, the EPA will develop the design for pilot projects in the Cataldo Reach and will also continue investigation at other locations in the Cataldo Reach.  

The Gray’s Meadow Remedial Action and Restoration Project entered its fourth year with the expectation of being near competition. However, the project experienced delays due to wet weather keeping soil soft where heavy equipment was needed. Work resumed in mid-May once conditions were suitable for heavy equipment to operate. Crews excavated and hauled 430,000 cubic yards of soil that were consolidated on site and used to build other features. The removed soil was used to build about 5 miles of embankments to manage the water within the new wetlands and provide access roads for operation and maintenance.  

The soil was also used to build over 25 habitat features throughout the wetlands that provide waterfowl with clean resting areas after feeding. Contaminated soil was used as the base for building these features on site and were capped with 12 inches of clean soil. Ten water control structures were constructed in the wetlands to convey and control water surface elevations within the wetlands. Construction is expected to resume in the summer of 2025, and the overall project is expected to be completed by fall.  

As of 2024, a total of 3,935 properties have been remediated as part of the Basin Property Remediation Program. Three residential properties were sampled for potential remediation in 2024. Properties remaining to be sampled and/or remediated are those whose owners have refused access or have been unresponsive to repeated contact attempts by the CDA Trust and IDEQ. 

Work is being completed in the East Smelterville flats. The 16-acre site is contaminated with historical mine tailings and wastes, with soil sampling indicating contaminated material is present at the surface to depths ranging from 5 to 9 feet. Remediation will reportedly take place in two phases once work resumes in 2025.  

“It has been incredible to witness the progress made over the past construction year," Bosley said. "The completion of the major remediation projects in the East Fork Nine Mile area, after more than a decade of effort, is particularly exciting. Looking ahead to next year, I’m eager to see continued progress in Canyon Creek. These efforts will have a significant impact on improving water quality, not only in Canyon Creek but also in the South Fork of the Coeur d’Alene River.”

    The East Fork of Ninemile Creek near the Tamarack Mine Complex. The creek bed used to run beneath a pile of mine waste that was recently cleaned up.