Since Bomboré's second stage expansion was built upon the site data accumulated in the first stage, it started with a planning advantage, yet became a process at least as challenging as the first stage on the execution side. With the increase in plant capacity, the surface area of the tailings storage facility expanded significantly, and the hydraulic integration of the new cell into the existing facility required special connection details at transition zones.

Although the long dry season in Burkina Faso's Sahel climate zone is favorable in terms of geomembrane welding performance, surface temperatures reaching the 60-70°C band during midday made it mandatory to recalibrate welding parameters multiple times during the day. Panel layout planning was prepared by taking wind direction and dust movement into consideration; the membrane was kept stable under all conditions prior to welding using ballast sandbags and temporary anchor trenches.

All weld seams applied within the scope of Stage 2 were fully verified through air pressure test and vacuum box test procedures; at the end of the process, handover was achieved with zero major non-conformity during the inspection conducted by the employer's independent CQA consultant.