Microbial analysis of ground water, as a solely supplying water sources must be evaluated in many areas. Because of the treatment of water always cannot remove all pathogenic bacteria which are leaked from domestic wastewater, bacterial survey of Bojnourd groundwater sources were carried out in this study. For this reason, membrane filter (MF) technique and Most Probably Number (MPN) methods were used to evaluate the quality of the water. Escherichia coli (E. coli) and Enteroccocus faecalis (E. faecalis) were traced as excremental indices. E. coli was detected from three out of six stations and E. faecalis was only isolated from one of stations. Although molecular techniques are very rapid and exact technique for detection of microbial community and are able to identify Viable But Not Cultivable bacteria (VBNC) but are unable to distinct live and dead microorganisms. By using standard technique it is possible to study live microorganisms. It can be concluded that both E.coli and E.feacalis was detected in some stations. The sanitization of groundwater must be revised to less the microbial population in this groundwater.

Keywords: Bacterial indices, microbial cultivation methods, MPN, membrane filter