Lundin Mining operates five mines with five active tailings facilities and uses two widely accepted methods of tailings disposal:
- underground disposal involves mixing tailings with products, such as sand or cement, followed by disposal as a paste backfill or hydraulic backfill in previously mined areas of underground mines; and
- surface disposal involves placement in engineered surface impoundments or, in the case of Eagle, in a previously mined open pit.
Of the five Lundin Mining operations, Eagle Mine is the only operation that does not have a constructed tailings impoundment with dams. Across the other operations, the active tailings facilities use various construction techniques for the main and secondary or perimeter dams, but none use upstream construction. Lundin Mining also maintains and monitors six inactive/closed tailings facilities, one of which is a rockfill combination centreline and downstream design followed by rockfill upstream raises and buttresses (Enemossen tailings facility at Zinkgruvan).
All tailings facilities are operated or closed as per the currently approved design. Full and complete engineering records including design, construction, operation, maintenance and/or closure exist for all tailings facilities except for the inactive Enemossen facility at Zinkgruvan, and closed San Esteban and Ojos del Salado facilities at Candelaria. San Esteban has an updated detailed design closure plan and the three Ojos del Salado tailings facilities are legacy sites that ceased operations in the 1960s. The Ojos del Salado tailings facilities were fully closed in 2012 as per an approved engineered closure plan.
A full list of tailings facilities that Lundin Mining manages, including information on construction method, maximum dam height and volume, can be found in the Tailings Management Information Sheet.