Summer Accomplishments at the Bonita Peak Mining District Superfund Site

EPA - Region 8 sent this bulletin at 10/01/2025 01:51 PM MDT

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US Environmental Protection Agency Region 8

Bonita Peak Mining District

Superfund Site

October 1, 2025

Summer Accomplishments

October 2025

Drilling for OU2 at the Bointa Peak Superfund Site

Monitoring well instillation at the BPMD Site – Photo taken on September 25, 2025

This summer, the Environmental Protection Agency (EPA), Bureau of Land Management (BLM), Forest Service (USFS), and State agencies worked on several important cleanup and monitoring projects across the Bonita Peak Mining District Superfund Site (BPMD). In addition, agencies took part in a variety of community involvement activities. Together, we achieved the following:

Mine Cleanup Projects

Anglo Saxon Mine – Stabilized the hillside and waste rock pile where the old crib wall collapsed and was removed.  The disturbed area was seeded with a brown colored hydroseed to revegetate the area for future erosion control.

Anglo Saxon Mine stabilized hillside where old crib wall was located

Stabilized hillside where old crib wall was located – Photo taken on September 24, 2025

Bandora Mine – Installed monitoring well into the mine adit, reestablished drainage channels, and removed settling ponds that were used during the drilling.

Bandora Mine Drill rig used for creating monitoring well

Drill rig at the Bandora Mine – Photo taken on July 27, 2025

Brooklyn Mine – The USFS removed two nuisance ponds and replaced them with a more natural channel. Consolidated mine waste into existing mine waste pile and amended with lime. Pile was seeded for revegetation.

Consolidated and seeded waste pile at Brooklyn Mine – Photo taken on September 2025

Columbus Mine – Redirected mine impacted water flow to protect native plants.

Tom Moore Mine – Replaced a degraded portal shed to prevent debris from backing up mine impacted water in the portal area.

Forest Queen Mine – BLM drained the mine adit and reconstructed the piping system at the portal area to mitigate the risk of an unplanned release. Allowing BLM to access pipes for long-term site maintenance.

BLM cleanup work at Forest Queen portal area- Photo taken on June 11, 2025

Koehler Mine – Inspected the concrete bulkhead to determine if additional reinforcements were needed to increase the longevity of the structure.

Additional Summer Activities

EPA scientists in the Office of Research and Development began a field test at the Bandora Mine for an innovative protective coating on mine waste piles that could help prevent metals from entering surface water due to waste rock pile erosion.  
Installed monitoring wells to investigate groundwater contamination near the Mayflower Mill tailings impoundments (OU2).

Drilling groundwater wells – Photos taken on September 24, 2025

Bonita Peak Repository (BPR) Update 

EPA expects to begin transporting treatment generated solids from the Gladstone interim water treatment plant to the repository this year. Clean fill and other supplies are expected to be trucked in quantities similar to previous years to finish covering and grading future Cells 2 and 3. Activities on the repository will continue until the snow flies, likely in early-mid November. Construction work as well as operation of the repository will resume in 2026. Stay tuned, more updates will be shared as the project progresses.

View of repository at Tailings Impoundment 4 – Photo taken on September 25, 2025

Community Engagement

Silverton Open House - On June 26, 2025, more than 40 community members, federal agency staffers, state partners, and stakeholders gathered in Silverton, CO for a public open house to discuss ongoing Superfund work at the site. The event provided an important opportunity for the local community to connect directly with agency representatives, ask questions, and learn more about our cleanup work.

Crowd at open house in silverton, co for BPMD

Silverton and EPA representative speaking at the Open House – Photo taken on June 26, 2025

Superfund Redevelopment Discussions - On June 26, 2025, San Juan County and the EPA Superfund Redevelopment Program held a reuse focused site visit and working session with key stakeholders. The purpose of the meeting was to discuss reuse options and considerations for San Juan County owned parcels near Mayflower Mill, which are part of Operable Unit 2 (OU2) of the BPMD site.

Community Advisory Group Tour - On Sept 16 and 18, 2025, the Bonita Peak CAG organized site tours. EPA project managers led the tour highlighting key site features and future cleanup priorities.

CAG tour around the BPMD Site - September 2025

BPMD CAG tour – Photo taken on September 16, 2025

Congressional Outreach - On August 21, 2025, Senator Bennet met with representatives of Silverton, San Juan County, La Plata County, State of Colorado, EPA, the BPMD CAG and members of the former Animas River Stakeholders Group to reflect on the history of the BPMD site and path forward.

Upcoming Cleanup Work

Red and Bonita Mine- EPA is preparing to do a long-term bulkhead valve closure to determine if it will reduce the amount of metals entering Cement Creek from this mine.

Terry Tunnel – BLM, EPA, and the State of Colorado will plant grass and other native plants to revegetate the covered waste pile – preventing erosion.

More Information

For more information about the Bonita Peak Mining District Superfund Site, please contact the site's Community Involvement Coordinator, Ashlin Brooks, at brooks.ashlin@epa.gov.

Bonita Peak Site Profile Page

EPA Region 8
Mountains and Plains

Serving Colorado, Montana, North Dakota,
South Dakota, Utah, Wyoming and 28 Tribal Nations

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