HB Mines Tailings Facility

The works outlined in the RCP were started on June 3, 2021 and were halted on November 23, 2021 due to severe weather and rapidly deteriorating site conditions. Works were resumed on July 4, 2022, and the project was completed on September 14, 2022.

The RDCK took steps to move the Facility to passive-closure by eliminating ponded water behind the dam, by increasing dam stability, and containing the tailings to prevent transport. Steps included:

• Expansion of the HB Dam toe berm to improve seismic stability and mitigate the risk of liquefaction of the original dam fill.
• Construction of an expanded spillway at the western abutment that is able to convey the probable maximum flood.
• De-watering of the tailings pond and backfilling of the pond to eliminate the ability for water to pond upstream of the dam and mitigate the risk of internal erosion.
• Construction of a tailings cover to prevent the erosion, escape, and migration of the tailings from the facility, remove the direct contact exposure pathway for human and wildlife receptors, and to provide a final surface to aid in revegetation.
• Import and placement of tailings affected soils from a downstream property in an engineered landform in the northwest corner of the Facility.
• Construction of lined channels over the tailings cover to convey surface drainage to the spillway.
• Decommissioning of the site borrow areas, including spreading of soils that were temporarily stockpiled.
• Revegetation of all disturbed areas.

After construction was completed in 2022, the Facility entered the active-care phase of closure, anticipated to last 5-7 years, where increased monitoring and oversight is completed to assess the Facility’s performance compared to projections in the design.

The post-closure monitoring program of the active-care phase, as defined in the Facility’s Mines Act permit and supporting documents, includes the following:

• Quarterly surface water and groundwater monitoring
• Flow measurements of surface water
• Porewater monitoring in the tailings area
• Annual drone surveys of the site
• Survey hub monitoring
• Event-driven monitoring of surface water after extreme rain events
• Invasive plant monitoring and treatment
• Metal leaching acid rock drainage monitoring
• Annual Revegetation monitoring*
• Annual Reclamation Research Program monitoring*
• Wildlife monitoring
• Weekly dam inspections during freshet, then monthly inspections for the remainder of the year, including instrumentation readings
• Annual Facility Performance Inspections, completed by the Engineer of Record
• Metals uptake studies in vegetation growing on the tailings in 2024 and 2027
• Annual downstream channel inspections

* 2025 reclamation research and revegetation monitoring results indicated that the Facility has achieved the revegetation objectives outlined in the permit, which specified that revegetation monitoring would continue annually until adequate vegetation has been established, and the vegetative cover is considered self-sufficient (80% survival and a minimum average of 80% cover across all plots). The Facility is now considered adequately vegetated, the vegetative cover is functioning as intended for erosion control and habitat development, and annual vegetation monitoring is no longer required.  The RDCK will proceed with two smaller scale programs in Year 5 and Year 10 post-closure (2027 and 2032), consistent with the recommendation of the Facility’s Qualified Environmental Professional.

As outlined in the Facility’s Mines Act permit, the RDCK is required to submit an updated 5-year Reclamation and Closure Plan (Plan) to the Ministry of Mining and Critical Minerals by March 31, 2027.

In April 2026, the RDCK initiated this Plan development process. As submission of this Plan will result in the Facility’s permit being amended, the intent is to use the Plan to outline a pathway to a reduction in post-closure monitoring, permit required reporting, and Health, Safety, and Reclamation Code required reporting. If successful, the reduction in monitoring and reporting will reduce long-term costs.  

The Facility is operated as part of Service 187 Central Subregion Resource Recovery and funded by taxpayers in the service area. Completing passive closure was the lowest cost option for long-term Facility management.

Based on the approved borrowing for the full project amount of $3,933,000 over a 20-year term, the annual cost for interest and principal on the loan is $243,184. The maximum possible taxation for the construction and remediation works is shown as a residential rate of $0.0467 per $1,000 of assessment.

• 2025 Annual Reclamation Report
• 2025 Dam Safety Review
• 2025 Annual Facility Performance Report
• 2026 Operations Maintenance and Surveillance Manual
• Glossary of Terms – Canadian Dam Association (CDA)
• Glossary of Terms – British Columbia Dam Safety Guidelines: Inspection & Maintenance of Dams (Section 1 – Definitions)
• HB Mine Tailings Facility Remediation and Closure Plan