The Evaluation Of The Concentration Of Chlorides And Sulphates In Surface Water Of The National Nature Reserve Čičov Oxbow

Abstract In the years 2013–2014 we evaluated changes in concentrations of chlorides and sulphates in waters of the National Nature Reserve Čičov oxbow depending on the time and place of sampling. Collections of samples were realized regularly at monthly intervals, always in the half of a month. Sampling sites were determined in order to assess the impact of natural and anthropogenic source of surface water quality. In order to evaluate the quality of surface water in the sampling sites by individual indicators, we used the values of the 90th percentile (P90), which was calculated from the measured values and then compared with their matching set of limit values referred to the Regulation of the Government of the Slovak Republic No. 269/2010 Coll. According to that Regulation, the recommended value for chlorides is 200 mg dm;; and for sulphates 250 mg dm−3. Based on the calculated values of 90th percentile (P90) of these indicators, we found out that the calculated characteristic values are lower.