STUDY OF THE WATER QUALITY INDEX (WQI) IN NAJAF GOVERNORATE, AL-KUFA AND AL-ABASSIYA RIVERS AS A CASE STUDY

Water Quality Index (WQI) is a practical and distinctive way to gauge the quality of water. It is frequently used to analyse water quality and determine its suitability for various uses by stating the status of the water in plain terms (good or terrible, usable or unusable, etc.). The purpose of the study is to evaluate the water quality index (WQI) in the Euphrates River (Al-kufa and Al-Abassia rivers). The site was monitored and evaluated, then data collection over a two-year from 2022 to 2023 on two station sampling sites, S1 and S2 within the river. Twelve physio-chemical parameters were examined in accordance with the Canadian Council of Ministers of the Environment Water Quality Index methodology (CCME WQI) in order to determine the WQI. These parameters (pH, turbidity (TUR) dissolved oxygen (DO), total dissolved salts (TDS), sulfate ion (SO4-2), Chloride ion (Cl-), nitrate ion (NO3-), Phosphate ion (PO4-3), total hardness (TH), alkalinity (Alk), calcium (Ca2+), and magnesium (Mg+2). All data were within the World Health Organization's allowed limits, with the exception of SO4-2, TUR, and TDS, which all exceeded the WHO's allowable limits at the two stations (S1 and S2) over the study period, as well as chloride (Cl-) concentrations during specific months. At the S1 station, the highest values for the parameters (SO4-2, TDS, and TUR) were (466, 1100, 19.8) and (414, 1218, 20.15) in 2022 and 2023, respectively. At the S2 station, the highest values for the parameters (SO4-2, TDS, and TUR) were (427, 1043, 16.45) and (397, 1151.5, 22.55) in 2022 and 2023, respectively. during the study period the WQI displayed clear fluctuation, with good, fair, and marginal quality, The highest values were (79.12 and 65.81) at the S1 station in 2022 and 2023 and (86.1 and 79.33) at the S2 station in 2022 and 2023, respectively. According to the current study, human activity, agricultural runoff, and the discharge of improperly treated wastewater have all contributed to the pollution of the Euphrates River, rendering it unfit for human consumption unless properly treated