The Arnot Colliery in Mpumalanga sustained severe flood damage after heavy rainfall in early 2006. The flood damage sustained by the mine included underground flooding of coal mining operations severely restricting production, surface subsidence above the Shaft No.8 and Shaft No.10 goaf areas, complete failure of the U3 pollution control dam including various degrees of damage to the remaining surface pollution control dams (10 No.) in terms of safety and structural integrity.
Envitech was appointed by Eyesizwe (Pty) Ltd to carry out the required investigations, design of all remedial works and supervision of the construction works. Key features of the project included:
- Assessment of underground flooding of coal mining operations and pumping operations to bring the mine back into operation.
- Assessment and inspection of Shaft No.8 and Shaft No.10 goaf areas in terms of surface subsidence sustained as a result of flood damage.
- Assessment and inspection of all surface pollution control dams (11 No.) in terms of safety and structural integrity.
- Evaluation and design of all remedial works required as a result of flood damage.
- The remedial design included for HDPE geomembrane and geosynthetic clay liner (GCL) liner systems for four contaminated water lagoons and pollution control dams, and the preparation of CQA plans.
- The remedial design for the subsidence areas around Shaft No.8 and Shaft No.10 included extensive crack sealing, surface landscaping and stormwater drainage works.
- Compiling of tender documents, call for tenders and adjudication of tenders.
- Supervision of construction of all remedial works.
PROJECT HIGHLIGHTS
Pumping operations to decant flooded mine
Surface rehabilitation
Geosynthetic lining systems
Layout Plan – Plant Dams