Evaluation of Drinking Water Using the Water Quality Index in Hillah City (River Water, Tap Water, Reverse Osmosis Water)

Abstract The aim of the study was to assess the quality of drinking water in Hillah city by analyzing water (river water, tap water, and reverse osmosis water) using the Water Quality Index (WQI) according to Iraqi and international standards. Over the course of six months, from September 2024 to February 2025, 72 water samples were taken, 24 from rivers, 24 from taps, and 24 from RO plants. Using instruments like atomic absorption spectrometry, pH, conductivity, turbidity, hardness, and other tests, the physical and chemical characteristics and heavy metals were assessed. Statistical analysis to identify statistical differences, ANOVA and LSD were employed. The river water’s WQI = 230 designation as “Very poor water” (unfit for human consumption) was one of the most noteworthy findings and values. EC = 1226 μS/cm (maximum allowable limit: 750) is the cause of this. Turbidity = 10.4 NTU (limit: 5), TDS = 715 mg/L (limit: 200). TH = 439 mg/L (200 as the limit). Cd = 0.106 mg/L (0.01) is the limit. Limit: 0.02, Ni = 0.092 mg/L. Pb = 0.081 mg/L (0.01 as a limit).). WQI = 153 indicates that the tap water is “poor water” and needs further treatment. This is because of: EC is 1223 μS/cm. 714 mg/L is the TDS. NTU = 10.175 for turbidity. We come to the conclusion that tap and river water are currently unsafe to drink. RO water is preferable, but it needs improvements regarding heavy metals. The need to develop treatment plants and modernize infrastructure. Strictly implement WHO standards and improve screening and treatment procedures.