Determination of water quality and heavy metal content in bottom sediments of Eşen Stream between Ören and Uğurlu (Seydikemer-Muğla)

The study aims to determine the water quality and heavy metal contents in the sediments of Eşen Stream in the Seydikemer District of Muğla Province. According to the Water Pollution Control Regulation, the water analysis results were determined to be in water quality Class I for Cu and Zn, Class II for Pb, Class IV for Cr, and Class I, II, and III for Ni. According to the limit values of the World Health Organization (WHO) and the United States Environmental Protection Agency (USEPA), the heavy metal contents of the waters were determined to be of better quality due to the lower Cu, Zn and Pb metal concentrations, and of medium quality due to the Cr concentration being above the limit values. According to the Enrichment Factor (EF) based on heavy metal (Cu, Cr, Zn, Pb and Ni) concentrations in the analysis of sediments, low, moderate, moderately severe, moderately severe, severe enrichment and very severe enrichment were determined, and according to the Contamination Factor (CF) determined within the scope of the study, low, moderate, significant and high contamination was determined. When evaluated according to the Pollution Load Index (PLI), it is seen that all points are contaminated except points S6 and S20. According to the Geoaccumulation Index (Igeo), all sampling points were classified as unpolluted-moderately polluted in both periods. In the evaluation of the sediments according to the Ecological Risk Factor (ER), Cu, Cr, Zn and Pb heavy metals were determined as low ecological risk at each sampling point in the wet and dry periods; for Ni, it was determined as moderate ecological risk at point S1 (reference point) in the wet period and significant ecological risk at point S17. Ni heavy metal increased to high ecological risk at point S17 and medium ecological risk at point S18 in the dry period. According to the Potential Ecological Risk Index (PERI) calculated for Cu, Cr, Zn, Pb and Ni heavy metals, low ecological risk was determined at all points except point S17.