The installation of the overliner (drainage protective layer of gravel) took place after whole area of geomembrane was tested using Sensor DDS® technology. The total damage found during our testing was 102. The most common damage (more then 50%) was so called puncture from above caused by gravel penetrating through the liner from above. This happens when heavy machinery places the protective overlier onto the geomembrane and is pressing on it by its weight. When it turns sharply it also usually and creates a large tears or cracks in geomembrane.
We have helped the client to save a lot of problems and money by identifying these future leaks now. It’d be very expensive and technically difficult to repair these leaks when Tailing Dam would be in full operation.