Evaluating Study of Tigris River Water Quality and Three Water Treatment Plants within Nineveh Governorate

Tigris River considers the main resource of water for Mosul city, therefore it is of great importance to evaluate its quality continuously. In this study, chemical and physical properties of Tigris River had been studied within Nineveh governorate during the year (2012) by using the average values for ten selected sites. Computing of Water Quality Index (WQI) was done by using Weight Average (WAV) method. In spite of the large amount of the wastewater disposed into the river, the results indicated that Water Quality (WQ) in all the studied sites was suitable for irrigation purposes. For drinking purposes, only the first northern four sites were in need to simple treatment, while the following remaining sites need conventional treatment. The efficiency of the three main Water Treatment Plants (WTPs) on Tigris River were computed according to a new (WQI) that include new additional parameters and different relative weights. These three plants are; Mosul new left side (WTP), Mosul right side monotheist (WTP), and Mosul old left side (WTP). The efficiency results were (70, 62, 55)% respectively. The Low efficiency of the old plant was due to the high effluent concentrations of turbidity, SO4, total hardness, and TDS