Quality of the Surface Water in the Ratka Small Water Reservoir

Abstract

The aim of the contribution is to evaluate the state of the quality of the surface water in the Ratka small water reservoir and its surroundings. The Ratka small water reservoir is included in fishing grounds; it is therefore necessary to know the quality of the surface water. The work is focused on an evaluation of the surface water quality indicators, i.e., the water temperature, pH reaction, content of the nitrate nitrogen, nitrite nitrogen, and the ammonia nitrogen, the chemical oxygen demands, and the total organic carbon. The analysis was divided into field measurements and laboratory measurements. Three sampling points were identified, from which samples were regularly taken. For water temperature and pH reaction, the field measurements were performed every month during 2019 and for other selected indicators of water quality, the field measurements were performed during April – September 2019. The laboratory analyses were realized in 2019 (summer, winter) and were focused only on samples from the Ratka small water reservoir. To evaluate the results, they were compared with the recommended values found in the valid Regulation of the Government of the Slovak Republic No. 269/2010 Coll. After evaluating the results of the study, increased values indicators of quality of the surface water were found water temperature, pH reaction, N — NO2 , chemical oxygen demands and total organic carbon. Phosphate contents are also present in the water. The results showed that the Ratka small water reservoir, due to the increased values of the mentioned indicators of the quality of the surface water, does not meet the set conditions of the Government of the Slovak Republic. The significance of this study can be seen not only in the importance of water quality assessment from the practical point of view, but also in the need to perform these analyses, especially in areas where no water quality assessments have been performed so far, an example of which is the Ratka small water reservoir assessed in this study.