WHAT'S HAPPENING NOW WITH THE CLEANUP?

START DATE:   Mid-January 2025 

ESTIMATED TOTAL COST:   $5 million+ (incl. monitoring & maintenance)

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LOCATION & DESCRIPTION: 

   ==> See all Phase 7 cleanup design and related documents HERE.

A 40-acre site ~10 miles south of Deer Lodge to the east of Racetrack Pond, running 2.2 river miles SW to NE beginning just north of Gemback Road. 

CHARACTERISTICS:

Relative to other phases, the Strategic Plan characterizes Ph. 7 as "Moderate Priority" for erosion and risk of contaminated sediments reaching the river; and "High Priority" for contaminated soil levels, as this area includes a public fishing access (see Strategic Plan, pp.11-12). DEQ estimates it will remove 135,800 cubic yards of mine waste-contaminated material from the site.

STATUS (as of September 2025)

Construction began in January (carried out by Intermountain Construction Services of Butte, who also worked on Phases 5/6, Silver Bow Creek, and the Trestle Area in Deer Lodge) and is expected to conclude in mid-December 2025.  The public is advised that the river, but not the floodplain, is open to public use during construction. CFRTAC raised numerous issues in its comments on the Phase 7 design, including the extent and location of contamination removal (reduced from previous phases); the preference for more woody debris on banks and instream; the need to monitor the river's response to lower bank designs; and more.  CFRTAC was generally satisfied with the State's  response to comments, though some issues, such as how the 100-year Channel Migration Zone is applied to determine removal boundaries, will not be considered until future phases. (Learn more in our February and May 2025 newsletters.) The State estimates that the project will finish slightly over budget due to finding areas of deeper tailings in need of removal than was originally anticipated. Final Phase 7 costs will inform the State's upcoming updates to its 2023 CFROU Strategic Plan.

ESTIMATED START DATE:   No start date currently estimated

ESTIMATED TOTAL COST:   $20.62M (may change) 

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LOCATION & DESCRIPTION: 

Includes Arrowstone Park. Extends through Deer Lodge from the I-90 bridge at Exit 187 (eastbound) north to the city's boundary with Grant Kohrs Ranch (near the Cottonwood Creek confluence).  

CHARACTERISTICS:

This phase is of high concern because temporary soil caps installed ~30 years ago at Arrowstone Park are failing in some areas, exposing arsenic and other contaminants that have created public health risks. As noted in DEQ's 2024 Clark Fork River News, community concern led DEQ to prioritize cleanup here. In the interim, DEQ installed safety signage and added temporary soil caps on bare spots to cover exposed toxic contaminants. 

STATUS  (as of September 2025):

DEQ is conducting additional sampling at the site to fill data gaps, which entails examining soils at greater depth in some areas, and to doing additional surface-level sampling in other areas. These findings will help determine contamination removal boundaries and depths, which is necessary before a cleanup design can be drafted. DEQ continues to coordinate with EPA to determine cleanup levels for arsenic, which are expected to be more protective of human health than originally considered in the ROD, given the level of public use of the park. (See our May 2025 newsletter for more details.) Cleanup here has been delayed as the State and EPA reexamine the arsenic cleanup standard to be used at the site. A stricter standard will be more protective of human health, but will likely also increase costs and cause delays. While the site is being monitored to determine if additional soil caps are needed to cover exposed soil, the public is advised to obey caution signs, avoid areas with exposed soil, and wash hands, boots, pets, boats, etc. after any potential exposure to contaminated soils, especially on the river banks. 

COMPLETED PHASES (maintenance & monitoring underway):

• Phases 1 & 2: Completed in 2014 and 2016
• Phases 3 & 4A: Completed in 2023
• Phases 5 & 6: Completed in 2016 (Ph 5 pictured above)
• Phases 15 & 16: Completed in 2021
• Deer Lodge Residential Yards; Trestle Area; Eastside Rd. Residential Area; and Eastside Rd Pastures: Completed in 2011, 2012, & 2016
• See Phase Status Map below for locations of these & other phases
• For a detailed technical update, read the 2023 Status Report (Qualitative Rapid Assessment) for Phases 1, 2, 5, & 6 - released by DEQ and NRDP in April 2024

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NEXT UP AFTER PHASE 7 & PHASE 13/14 (described above):

• Phases 10-12: These phases are combined as they share haul roads, which are all accessed from Sager Lane. Sampling plans for these phases is underway (as of September 2025), with spring 2026 sampling plans pending, as they require State and EPA approval. Cleanup work is estimated to begin in 2027.

Phases 7 and 10-14 (described above) were prioritized for cleanup based on the ranking criteria described on p. 12 of the 2023 Strategic Plan. Other phases will be addressed in an upstream-to-downstream sequence after these higher-priority phases are completed. These include:

• Phase 4B:  Estimated to start in 2029. Phase 4A was completed in 2023. 

• Phases 8 and 9:  Estimated to start in 2030 and 2031. This area of the river is considered to be suitable to provide refuge for fish and wildlife displaced by work in earlier phases. 

• Phases 17 - 22: To be completed in order after Phases 8 & 9, with some possibly being combined. At roughly one phase per year, (with Phase 17 A & B taking a year apiece), annual start dates will be from 2032 to 2038.

• Maintenance and monitoring for completed phases is ongoing. The Strategic Plan estimates this work will continue beyond construction of the final phase from 2040 through 2044.