Evaluation of efficiency of water treatment plants in Baghdad city using comprehensive pollution and water quality indices.

To ensure that people have access to safe drinking water, it is necessary to evaluate quality of the water produced in water treatment plants (WTPs) and to maintain high performance efficiency. This work aims at using a combined Comprehensive Pollution Index (CPI) and water quality index (WQI) to evaluate and characterize the water quality produced by eleven WTPs in Baghdad City and their efficiency during autumn 2019 to summer 2020. Nine water quality parameters (WQPs) including pH, turbidity (TUR.), total dissolved solids (TDS), total hardness (TH), chloride (Cl-), nitrate (NO3-), iron (Fe), Aluminum (Al) and total coliform (TC) were measured. A comparison of the WQPs levels of the treated water with the World Health Organization (WHO) and Iraqi Criteria and Standards of water's chemical limits (ICS) showed that all WQPs exceeded these guidelines except pH and NO3-. Due to the comparison, the water produced by the eleven WTPs was unsuitable for drinking. Based on result of the CPI classification, the Al-Sader, Al-Baldiat, and Al-Kadhimiya WTPs were slightly polluted, CPI(0.41-1.00) while the other WTPs were medium polluted, CPI (1.01-2.00). The water produced by the eleven WTPs was classified in terms of WQI values as poor (51-75) to very poor (76-100) for all WTPs during the study period except Al-Wathba, Al-Qadisya, Al-Dora and Al-Rasheed which are classified as Unsuitable for Drinking(WQI>100). In the current study, a new tool was introduced to evaluate the performance efficiency in terms of CPI and/or WQI values. Based on this tool, the efficiency of the eleven WTPs during the study period ranged from low to very low for the older WTPs to medium for the newer WTPs. This assures the necessity to undertake serious actions in monitoring the water treatment plants and in managing it properly. [ABSTRACT FROM AUTHOR]