Identification of Water Contamination Sources Using Hydrochemical and Isotopic Studies—The Kozłowa Góra Reservoir Catchment Area (Southern Poland)

The application of combined research methods, such as hydrochemical and isotopic analyses, facilitates understanding the origin water constituents migration contaminants in aquatic environment. presented study attempts to identify contamination sources affecting quality within Kozłowa Góra reservoir catchment area (southern Poland). A total 100 samples were collected from surface (the Brynica river, streams, reservoir) groundwater (a Quarternary aquifer) four time periods. During fieldwork, physicochemical parameters measured (temperature, pH, electrical conductivity, redox potential, dissolved oxygen). chemical analysis included determination major ions (HCO3−, SO42−, Cl−, Ca2+, Mg2+, Na+, K+), nutrients (NO3−, NO2−, NH4+, PO43−), organic carbon. was complemented by sulphur oxygen sulphate, which enabled a more precise identification stressors different parts area. Chemical results (δ34S = 4.38–13.99‰; δ18O 3.59–13.30‰) revealed that wastewater discharges agricultural activities have significant influence on chemistry River other streams. At some sampling points, lower manifested elevated concentrations NO3− (up 22.6 mg/L) several (e.g., up 114 mg/L for 51.52 12.5 PO43−). deteriorated mainly infiltration sewage leaky septic tanks. level varied depending location, higher values conductivity observed residential areas. recharge drinking reservoir, thus its depends these sources. dilution presence biochemical processes led reduction contaminant (down 3.5 NO3−, 32 0.21 <0.05 PO43−) compared river streams supplying reservoir. role discharge evolution chemistry. will be used further substances water, including microcontaminants.