| Summary: | From the results of monitoring of the quality of surface water in the Hnilec and Hornád rivers and their tributaries followed that in addition to industrial toxic substances, it were the heavy metals from localities of former and still continuing mining, treatment or metallurgic activities that significantly influence a long-term polution. The subsequent project showed a need to monitor the impact of anthropogenic activity, namely on the Waterwork (VD) Ruín I. It was a task of our institution to judge the quality of sediment loads in the waterwork area.The first samples of sediment loads of the waterwork were taken in 1994. The sampling process then continued on the same places in following years. The special methods of sampling of sediment loads (sediments) from the waterwork bed were worked out depending on the locality of sampling. The total analysis of obtained air-dried samples was caried out using the AAS method. The heavy metals were also analysed. In the consent with standards and requiremnts of the co-ordinator of task, the sediment deposits were assessed in consent with Decree of the Ministry of Land Managment of the Slovak Republik 531/1994-540 on the highest admissible values of harmful subsatances in land.Comparing the results of sampling we have observed that the critical values have been achieved in case of Cu. Its high values were found in the branches of Hnilec and Hornád rivers, as well sa in the branch of Opátka. The increased contents of Co are in Beliansky and Opatsky branches, at the inflow of Hnilec and Folkmarsky brook into the waterwork. The position of Hg is interesting, as it was the main contaminating element of The Hornad river and its sediments in the past. Hg is not currently present at significant quantities.The vertical sampling was also carried out in the course of research. It was proved that the content of contaminating elements in sediments of waterwork originates in the industrial activity perfomed 15-25 ago. At present these sources of contamination are non-active.Special dumps-sludge basins represent an exeption, as they are sources of pollution of surface water, as well as of uderground water. In consent with the valid legislation, the supervision over the sludge-basins is performed by the sludge-basin keepers, who prepare assessment reports, available only to a limited number of experts.The results characterising waste waters from the sludge-basins in Smolník and Rudòany show that the water draining through a drainage system from the sludge-basins may significantly influence the quality of surface streams.From the mentioned facts follows that it is necessary to remove the contaminated sediment loads from VD Ruín I. The alternatives have been suggested.The contamination of sediment loads in VD Ruín I. continues, so that the requirement for continuing far in monitoring its surface layer and water at least in 3 year intervals is substantiated.The evaluation of results of monitoring of waters leaving the sludge-basin will show, which of them decisively contribute to the contamination of sediment loads in the reservoir of VD Ruín I. This should enable to prepare technical measures to capture the substantial quantity of contaminanting elements, so that in the future it would not be necessary, for the exploaitation of further sediment loads, to use expensive treatment procedures, this would result in the improvement of environment in the waterwork and its surrounding area.
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