Al Mafraq WWTP is one of the three major WWTP situated in Abu Dhabi Mainland. It receives and treats wastewater from Abu Dhabi City and all its surrounding mainland catchments. Phase-1 was commissioned in 1982 with a DWF capacity of 104,250 m3/day and is capable of handling peak flow of 271,000m3/day. Phase-2 was commissioned in 1997 and is of a similar process design to Phase-1, but with some improvements and variations. Phase 2 developed from experience in the operation of Phase-1, for better control and treatment. Its DWF capacity is 156,375m3/day and is capable of handling peak flow of 312,750m3/day.