Raising efficiency of the sewage treatment plant at Al-Kharj Road to tertiary. The total area of the plant is estimated at 200,000 m2 with its facilities, it includes 24 sand filters for the triple treatment stage, with a capacity of 200,000 m3/day (medium flow), 320,000 m3/day (peak flow), architectural, structural, mechanical, electrical and electronic works at the plant, Environmental development of plant facilities through treatment and disposal of sludge and installation of a treatment and odor control system to preserve the environment and Development of the plant facilities (roads, corridors, sidewalks, landscaping and green spaces) and revision of all the relevant designs.