Pakistan Tanners Association imitated comprehensive environmental management program in 1994 and construction of combined effluent treatment plant (CETP) was one of the major component of the program. The scope of the plant is to treat the wastewater generated from 170 tanneries located in cluster of sector 7A, 15 and 17 of Korangi Industrial Area. The major components of project included construction of treatment plant, wastewater collection system for tanneries and conveyance of domestic wastewater to the plant from nearby pumping station of Karachi Water and Sewerage Board (KW&SB). The total design capacity of plant is 42,000 m3/day [42 MLD] with 16,500 m3/day of tannery and approx. 27,000 m3/day of domestic wastewater. The treatment scheme is combination of anaerobic treatment (UASB) with aerobic treatment system for effluent polishing.