DRINKING WATER SAFETY FROM PRIVATE WELLS IN ZAGREB
Autori:
Ankica Senta, Marija Marijanović Rajčić
Sažetak
Sažetak. U tri gradske četvrti Zagreba – Pešćenici, Trnju i Trešnjevci ispitana je bakteriološka kvaliteta vode iz privatnih zabijenih zdenaca u četiri navrata 2003. godine. Cilj je bio utvrditi kakvu vodu pije 5% stanovnika Zagreba koji nisu priključeni na vodovod. Ukupne koliformne bakterije, fekalne koliformne bakterije i enterokoki određeni su metodom višestrukih epruveta, a broj aerobnih bakterija brojenjem uzgojenih mikroorganizama na agaru. Najbolju kvalitetu imali su uzorci na Trnju, a najlošiju na Trešnjevci. Od 34 uzorka uzeta iz privatnih zdenaca 21 je bio zdravstveno neispravan (61,8%). Samo jedan zdenac s Trnja imao je zdravstveno ispravne uzorke u sva četiri godišnja doba. U 24 uzorka je dokazana prisutnost ukupnih koliformnih bakterija (od 2 do >240/100 ml), a u 16 iznad maksimalno dopuštene koncentracije (MDK). Fekalne koliformne bakterije dokazane su u 17 uzoraka u rasponu od 2 do >240/100 ml. Enterokoki su dokazani samo u dva uzorka na Trešnjevci (jesen) i u Trnju (proljeće). Aerobne bakterije na agaru nađene su u svim uzorcima u rasponu od 1 do 1920, a u 8 uzoraka iznad MDK.
Summary
Summary. Bacterial quality of water from private wells was examined seasonally during the year 2003 in 3 districts of Zagreb – Pešenica, Trnje and Trešnjevka. The aim of the study was to estimate the quality of water consumed by 5% of citizens who are not connected to the public water supply system. Total coliforms, fecal coliforms and Enterococcer were determined by the multiple tube (most probable number) method, and the heterotrophic plate count by enumerating culturable microoorganisms. Samples taken from Trnje had the best water quality, and the worst were from Tre{njevka. 21 out of 34 examined samples were sanitarily unsatisfactory (61.8%). Only one private well had no bacterial contamination and was satisfactory in all four seasons. Total coliforms were detected in 24 samples and values were from 2 to >240/100 ml, and 16 samples had values above maximal allowed concentration (MAC). Fecal coliforms were detected in 17 samples and values
were from 2 to >240/100 ml. Two samples contaminated by Enterococcus were taken from Tre{njevka (autumn) and Trnje (spring). Heterotrophic plate count (colony count) was present in all samples, values being from 1 to 1920/ml, but were above MAC in 8 samples.
