The quality of alum sludge is highly dependent on the source of water quality, quality and purity of the alum and other treatment chemicals used, such as powdered activated carbon for taste and odour control, and polymers used to aid flocculation (Maiden et al., 2015, Zhao et al., 2011 and Babatunde and Zhao, 2007). Therefore, physico-chemical properties of alum sludge could vary widely depending the above factors. Physico-chemical properties of alum sludge based on available literature data and its comparison with American Society of Civil Engineers (1996) values are described in Table 1.