en Environmental Health, Sciences, and Engineering Environmental Health, Sciences, and Engineering پژوهشي Original Article <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family: times new roman;"><strong>Background:</strong> Providing safe drinking water has critical importance to human societies. The aim of this study was to investigate microbiological quality of drinking water in distribution system of urban and rural regions of Ijroud, in Zanjan province<span dir="RTL">.</span><br> <strong>Methods:</strong> In present descriptive study, the microbiological examination of drinking water was conducted in 15 facilities with 401 samples. Transportation and test procedures were according to standard methods for the examination of water and wastewater<span dir="RTL">.</span><br> <strong>Results:</strong> Total number of microbial samples were 401 and 66.66% of them were positive for total and fecal coliforms. Also, water of 10 villages were not suitable for drinking with respecting to national standards. In addition, samples of only 5 villages were suitable for human consumption. The range of fecal coliforms in distribution networks&#39; samples were from 4 to 75 MPN/100 ml. This study showed that as microbiological aspect, drinking water is not potable in some rural communities. The consumption of drinking water in this distribution networks can threaten the health of consumers, thus, the water supply organizations have to improve operation and maintenance measurements due to prevent the spread of water-borne diseases<span dir="RTL">.</span></span></span><br> <span style="font-size:14px;"><span style="font-family: times new roman;"><strong>Conclusion:</strong>This study showed that as microbiological aspect, drinking water is not potable in some rural communities. The consumption of drinking water in this distribution networks can threaten the health of consumers, thus, the water supply organizations have to improve operation and maintenance measurements due to prevent the spread of water-borne diseases<span dir="RTL">.</span></span></span></div> Drinking water, Microbiological quality, Ijroud, Zanjan 47 53 http://jhehp.zums.ac.ir/browse.php?a_code=A-10-41-2&slc_lang=en&sid=1 Mehran Mohammadian Fazli mhrnmoh@zums.ac.ir 10031947532846009525 10031947532846009525 No Department of Environmental Health Engineering, School of Public Health, Zanjan University of Medical Sciences, Zanjan, Iran. Zahra Tohidloo adeltohid@gmail.com 10031947532846009526 10031947532846009526 Yes Environmental Health Sector, Health Center of Ijroud Town, Ijroud, Iran. Masoud Hosseinloo 10031947532846009527 10031947532846009527 No Department of Emergency Medicine, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.