Surface water bacterial plankton in the vicinity of two nuclear power stations in Slovakia

Environmental impact on microbial population of surface waters during const ruction and operation of two Slovak nuclear power plants (NPPs) was studied . The study covers the period of construction and trial operation start-up of the Unit 1 of NPP Mochovce (PMO) and the period of NPP Jaslovske Bohunic e (PBO) operation, from July 1996 to June 1999. Our attention was focused o n the incidence of groups of microorganisms indicating general pollution in waters (psychrophilic, mesophilic and spore-forming bacteria) as well as h ygienically important bacterial factors of faecal pollution (enterococci, c oliform, thermotolerant coliform bacteria and presumptive Escherichia coli, estimated by the most probable number method). Water samples were taken fr om selected localities in the vicinity of both stations monthly or bi-month ly. Since 1997 114 strains of Enterobacteriaceae family in both places were identified. The analysis of bacterial spectra showed that during the three year period, the industrial wastewater outflows neither contributed to the bacterial contamination, nor affected negatively the bacterial biotopes of recipients and waters of Vah and Hron rivers.