Used Astrasand Sand Filter Type AS-500-30, manufactured by Paques Astraco, 2001. Astrasand is a continuous sand filter in which the filter bed is continuously cleaned during the filtration operation. It has been developed for use on different types of water such as process, waste, surface, cooling and ground water. Physical dimensions 2500mm diameter, 5500mm on the straight, 2200mm cone. Filter comes complete with galvanized steel staircase and access platform.