Project Title

Galmoy Mine TMF Cell 3 Capping and Wetlands | Golder

Location

Kilkenny, Ireland

Client

Galmoy Mines Limited (Lundin Mining)

Date

10/2013 – 04/2015

Business Sectors

Mineral Resources

Services (Technical Disciplines)

• Design and CQA of capping for TMF Cell 3, circa 6 ha, partially filled with lead/zinc tailings.
• Design CQA of a Surface Water Treatment and Discharge System for the entire TMF comprising a wetlands constructed over the capped tailings within Cell 3, spillways and outfall structures.

Project Objectives/ Outcomes

The Galmoy Mine was an underground lead and zinc mine which ceased processing ore in June 2009 but continued with extraction of ore until October 2012.

The Galmoy TMF was divided into three cells, each having a separate life cycle of construction, tailings disposal operation and rehabilitation. Cells 1 and 2 were rehabilitated with a soil cap following the levelling of the tailings when their capacities were attained. Cell 3 was only partially filled with tailings and Closure Plan was modified to include the treatment wetlands within Cell 3, above the capped tailings, rather than adjacent to the TMF.

Our Role

The design for the rehabilitation of Cell 3 comprised the modification of the original Closure Plan to cap the reduced volume of tailings within, with material sourced from surrounding dam walls, which were no longer required to be at their constructed height.

The wetlands was designed to be constructed above the capping and the surface water runoff system from the rehabilitated Cells 1 and 2 was modified to allow passage of runoff through the wetlands. The wetlands comprise five raised ponds, with flows from Cells 1 and 2 merging and flowing in series through the ponds to the Cell 3 spillway discharge, and subsequently to discharge at the Glasha River via an Attenuation Pond.

The design services provided for the capping of Cell 3 comprised 3D modelling, preparation of drawings, specification and construction methodology and sequencing. Golder provided the civil and structural design for the wetland ponds, the discharge structures between ponds, the spillways and the outfall.

Subsequently, Golder provided part-time CQA services, in conjunction with the Galmoy Mine Closure Team, for the duration of the Works (October 2013 to April 2015) and managed the production of the CQA Validation Report.

Geoscience Ireland Contact

Balding, Barry – Barry_Balding@golder.com