Alcoa’s Pinjarra Aluminium Refinery is approximately 80 km south of Perth. One of the projects in the Refinery was the conversion of an approximately 17 ha of the existing wet mud lake into approximately 11 ha of new RSA1E dry stacking area in accordance with the residue long term planning strategy. To achieve the project objectives, it was necessary to remove or dewater the highly caustic tailings in the residue area.