Objectives:

This mine site is situated within the Mafefe village in the Limpopo Province.

The goal of this project was to provide a sustainable solution to the hazard of asbestos exposure and other consequential mining related hazards. The prevention of asbestos fibres becoming airborne and/or waterborne is of highest concern. The solution adopted was to provide capping and erosion protection to the dump which lies within a 1:100 year floodline. It was also to seal the entrance of the shaft as its stability is unknown and hazardous to the local community.

 Overview:

The contract comprised the capping and erosion protection of the facility by the use of a reno mattress cover, sealing off the entrance to shaft, re-vegetation, fencing and ancillary works.

Earthworks

The main purpose of the earthworks was to encapsulate any exposed asbestos fibres and to prepare the area for gabion basket installation and re-vegetation. The earthworks consisted of:

• Creating access roads within the site.
• Demolition of existing structures containing asbestos materials
• Drill, supply and install rock anchors to the surface area of the mine shaft entrance.
• Clear and grub area demarcated for capping.
• Surface excavation, shaping and compacting conducted on demarcated area, to establish maximum slope and provide a smooth and even surface for reno mattress placement.
• Excavation, shaping, surface preparation and compaction of trench conducted on perimeter of the demarcated area for the placement of the gabion basket wall.
• Importation of G5 material and topsoil to be used for backfill and compaction.
• Continuous dust suppression measures at all relevant area’s during all phases of construction, so as to prevent asbestos fibres from becoming airborne.

Gabions and Pitching

• Installed, filled and grouted gabion basket wall at the mine shaft entrance.
• Installed geofabric (A4 bidim) in gabion wall trench, and on the remaining footprint of the demarcated areas.
• Installed 160 gabion baskets (1000mm x 1000mm x 1000mm) in trench.
• Installed 297m³ of reno mattresses (6000mm x 2000mm x 170mm) over demarcated asbestos dump area.

Re-vegetation and Fencing

• Place, shape and compact topsoil layer to the entire footprint of reno mattress area.
• Re-vegetation of the topsoil area to the vegetation specification standards.
• Supply and install Bio-degradable soil blanket (Biojute) over top-soiled footprint.
• Water vegetated area to promote growth.
• Supply and erect permanent fencing and access gates around the perimeter of the rehabilitated area