Safe water production is the world's primary concern; however, organic pollution is a continuous threat to it. Egypt depends primarily on the Nile River to supply potable water. Organic pollution threatens freshwater, and it is reduced through effective conventional treatment, but using disinfectants generates harmful byproducts. This study aims to the evaluation of conventional treatment in eight WTPs in Cairo. Water Treatment Plants (WTPs) were chosen in greater Cairo to perform this study throughout the year 2018. Raw, tap water and sludge TOC was measured. Raw and tap waters SUVA254 is calculated to determine the WTP's efficiencies to reduce DBPs formation probability. The maximum and minimum TOC obtained in winter and summer, respectively. SUVA254 increased in Mostorod WTP and reduced in other WTPs. In conclusion, the Nile river organic matter is natural with a minimum amount of industrial origin, but the Ismailia canal suffers from industrial spills.