The effect of some refinery and industrial wastewater discharges located northwest of Erbil city on the water quality of the great zab river

Utilizing the Water Quality Index (WQI), this research evaluates the water quality across the Great Zab River in different sampling areas and the overall water quality. The investigation helps shed light on the possible sources of pollution. The whole picture, including both underlying natural conditions as well as human activities, is depicted by the combined effects represented by the WQI values. Results showed different water qualities from moderate to poor, on and off rising values of which are blamed on pollution arising from industrial plants and mixing with river water. The medium gradation of WQI in the upper part of the River Great Zab, 57.48, is consistent with the moderately good water quality and the lower value of WQI or rather the equal good water quality at the downstream part of the river where it is 56.00. In contrast, the Cola North Iraq plant and its confluence with the river have combined WQI values of 43.32 and 44.97, and therefore they represent unacceptable water quality. Nevertheless, the statistician shows that the locations of the refinery, the factory, and the power plant noticeably affect the water quality of the river at their blending points. The thesis results sharply remind us of the necessity to close our eyes strictly in an ecological way, establish environmental regulations, and make use of sustainable technologies to protect the nature of the river. Measures that are concise to eliminating pollutant sources and giving a boost to the environmental consciousness of communities must be integral in the conservation of the Great Zab River and the preservation of the surrounding ecosystems.