EVALUATION OF SELECTED CHARACTERISTICS OF SMALL STREAMS: THE SÚČANKA STREAM AND ITS TRIBUTARIES (TRENČÍN REGION, SLOVAKIA).

Surface water pollution occurs due to urbanization of the environment and the growth of industries. Monitoring of the pollution´ sources, regular control as well as analyzing of surface water status in small streams is a basic prerequisite for good condition and water quality in the rivers into which they flow. The functioning of the water system includes processes that affect the surface water cycle itself, the reduction of selected characteristics, the removal of toxic substances, the protection of the ecosystem and the aquatic fauna. This paper aim is to monitor the surface running the stream Súčanka (Trenčín region, Slovakia) and its three tributaries the Krasín stream, the Černatina stream and the Poľníky stream. The paper summarizes the data quality of the running water surface based on selected physical-chemical and chemical characteristics. The values of the analyzed data are related to the pollution of the water stream and affect the purity of the surface water of the stream. These monitored characteristics were analysed in the samples of the surface running water, which has been removed from the twelve sampling places in 2015-2017. The following selected characteristics were analyzed: temperature, the reaction of water (pH), conductivity, fluoride, chloride, sulfate, ammonia, nitrite and nitrate nitrogen and heavy metals (arsenic, copper, nickel, and lead). From the analyses of selected characteristics the stream Súčanka and its tributaries streams implies the following: the values of the temperature of this watercourse, pH, the concentration of chlorides, sulfates, ammonia nitrogen, and heavy metal (As, Ni, Pb) are within the limit values of the current legislation and standards. Increased values of nitrate and nitrite nitrogen concentrations, which exceeded limit value were analyzed at two sampling places, in the mainstream Súčanka in the range of 7.95 mg.dm^-3 even 11.60 mg.dm^-3 and the stream Černatina, in the range of 30.50 mg.dm^-3 even 32.10 mg.dm^-3. From the results of analyses of heavy metal concentrations, the greatest variability was found in the value of Cu concentration at the beginning of the village Dolná Súča (39.30 μg.dm^-3). Súčanka stream is not only an important regional hydric biocorridor but it is a trout fishing ground (district number 2- 2730-4-1). [ABSTRACT FROM AUTHOR]