Microbiological pollution as an indicator of well water quality in five counties of north-west Croatia

Rad pod naslovom "Mikrobiološko onečišćenje kao indikator zdravstvene kakvoće bunarske vode u pet županija sjeverozapadne Hrvatske" ima za cilj mikrobiološkom analitikom i prikazom količina oborina utvrditi jesu li mikrobiološka onečišćenja indikator zdravstvene kakvoće bunarske vode u praćena u razdoblju od 2012.–2020. godine. Mikrobiološka analitika odrađena je na Veterinarskom zavodu u Križevcima, a podaci o oborinskim prilikama u promatranom razdoblju dobiveni su od strane DHMZ-a. Utvrđeno je kako postoji razlika u zdravstvenoj kakvoći bunarskih voda između praćenih županija u promatranom razdoblju te kako oborinske prilike nisu imale značajan utjecaj na mikrobiološku ispravnost vode u bunarima. Napravljena je mikrobiološka analitika sljedećih parametara: Escherichia coli, Enterococcus spp., ukupni koliformi, broj kolonija na 22°C i 36°C i Pseudomonas aeruginosa. U 9 praćenih godina analizirano je 2 156 uzoraka u svim županijama, od čega je 545 (25.3%) pozitivno te 1 611 (74.7%) negativno na mikrobiološke parametre. U promatranom razdoblju izmjenjivale su se sušne, kišne, ekstremno kišne i normalne godine s obzirom na prosječne količine oborina promatrane kroz višegodišnje prosjeke. Godine 2012., 2015., 2016., 2017., 2018., 2020., klasificirane su kao sušne godine, a 2013., 2014., 2019., kao kišne s obzirom na višegodišnji prosjek DHMZ-a.The aim of the study "Microbiological pollution as an indicator of well water quality in five counties of north-west Croatia" was to use microbiological analytics and precipitation data to determine whether microbiological pollution is an indicator of well water health in five counties of north-west Croatia in the period from 2012 to 2020. Microbiological analysis was carried out at the Veterinary Institute in Križevci, and the data on precipitation conditions in the observed period were given by the Croatian Meteorological and Hydrological Service (DHMZ). It was found out that there is a difference in the health quality of well waters between the monitored counties in the observed period and that precipitation conditions did not have a significant impact on the microbiological safety of water in wells. Microbiological analysis of the following parameters was performed: Escherichia coli, Enterococcus spp., Total coliforms, number of colonies at 22 ° C and 36 ° C and Pseudomonas aeruginosa. A total of 2,156 samples were analysed in all counties in 9 monitored years of which 545 (25.3%) were positive and 1,611 (74.7%) negative ones for microbiological parameters. In the observed period, dry, rainy, extremely rainy, and normal years alternated with respect to the average amounts of precipitation observed over multi-year averages. 2012, 2015, 2016, 2017, 2018, 2020 were classified as dry years, and 2013, 2014, 2019 as rainy years considering the multi-year average of the DHMZ