The Water Research Institute Bratislava (Slovak Republic) had been dealing with sediment quality of the Zemplinska Sirava Reservoir within the national science and technological project for three years (1997-1999). This issue was handled again in 2003 in connection with verifying the methodical procedures for sediment disposal from water reservoirs and with additional surface water and sediment quality monitoring of selected specific organic pollutants as well. In 2004 the attention was focused on bottom sediment quality in vicinity of Strazske (Laborec-Krivostany, Laborec-Petrovce and the Strazsky Canal).
In this paper the results of sediment quality monitoring in the Zemplinska Sirava Reservoir in 2003 are presented, which are compared with those ones obtained in years 1997-1999. Furthermore the results of sediment quality in vicinity of Strazske from 2004 are evaluated.
The presented results show that bottom sediments in the Zemplinska Sirava Reservoir are substantially contaminated by PCBs, namely by Delors (Delor - 103 and Delor-106) and by PCB congeners. The values have been measured in the order of thousands μg/kg. In comparison to sediments from the Zemplinska Sirava Reservoir especial attention is paid to PCBs content in sediments from the Strazsky Canal. The values from the Strazsky Canal are one order of magnitude larger (in the order of ten thousands μg/kg) than the values in sediments of the reservoir. The results are fully confirmed by other authors, where PCBs content in this canal has been measured on comparable or even higher concentration level.