Determining Ankara River water quality using the NSF-WQI index and evaluation of the solution proposals

While Ankara Stream is an important tributary of Sakarya River, one of the largest rivers in Turkey, it is an important water source that should be monitored and scrutinized since it carries the pollution load of the region that is under high pollution pressure to the entire basin. As a result of the uncontrolled increase in water consumption resulting from increasing population, urbanization and industrialization in recent years, and the careless uses of fertilizers and pesticides in agricultural activities that mix up with water resources, it has become very vital to monitor the water quality of water resources. The water quality index method has become very practical to understand and evaluate water quality. Specifically, the National Sanitation Foundation Water Quality Index, the basis of other water quality index methods, is the most widely used water quality index in the world. In this study, the water quality index method, quite new in Turkey, is used for the first time in Ankara Stream, with the aim of determining the water quality classification. For this purpose, in each season of 2019 and 2020, water samples were taken from ten sampling stations selected along the stream, starting from the source of the Ankara Stream to the point where it joins the Sakarya River. To be used in water quality index calculations, a total of 20 parameters, including taken sample's temperature (the difference between surface and bottom temperatures), pH levels, turbidity values, fecal coliform (Most Probable Number Method), dissolved oxygen, biochemical oxygen demand, total phosphate and total nitrate analyzes, have been analyzed, and, consequently, Water quality classes are determined according to National Sanitation Foundation Water Quality Index.