TenCate Geotube® technology in Honduras
The El Mochito mine in Honduras has a tailings lagoon that contains large volumes of contaminated mine tailings slurry. Above the tailings lagoon is a large unstable area, known as the Guard Shack Slide, which has the potential to develop into an active landslide during heavy rainfall and to release large quantities of soil, rock and debris into the lagoon (as much as 400,000 m³).
This large volume could displace the contaminated tailings over the dam into the environmentally sensitive area below it or cause a catastrophic failure. This must be prevented and the solution is to construct two dams based on TenCate Geotube® technology.
Before installation of the TenCate Geotube® dam structure, the bottom was lined. After this, drainage pipes were installed parallel to each other, so that no water was retained behind the dams. The tubes themselves were stacked up two or three layers high and filled multiple times with mine tailings. The circumference of the tubes in the higher dam measure 14, 12 and 10 metres, from the bottom up. Thanks to the dewatering of the TenCate Geotube® units the dams gain their final form and solidity.
The use of TenCate Geotube® technology allows the liners to remain in place, the installation costs to be lower and the installation time to be shorter. To date there has been no major movement of the landslide. However, the Geotube® dam structure has controlled large volumes of rainwater and debris that has been dislodged.
Dewatering with TenCate Geotube® technology is a three-step process: filling, dewatering and consolidating. In the storage phases TenCate Geotube® is filled with dredged waste materials. In the dewatering phase excess water simply drains from the container. Often this water is of a quality that can be reused or returned for processing. In the final phase, consolidation, the solids densify as residual water vapour escapes.