Water bacteriological quality of cistern water in rural areas of Agh-ghala and Bandar Torkman, northeast Iran, 2008

Storage rainwater in cisterns for drinking has been common in many areas including Iran. According to World Health Organization, water is one of the most important ways for transferring of microbial contamination in human communities, so survey of water bacteriological quality in these cisterns is necessary in order to identify the possible sources of contamination and to suggest some procedures for improvement of the cisterns status. This descriptive study was conducted on cistern waters of rural areas in Agh-ghala and Bandar Torkman counties. A total of 40 cisterns of 8 villages were selected using cluster sampling method. For each sample, the number of coliforms and fecal coliforms, Ph and amount of the residual chlorine were measured according to the standard methods. In order to analyze the data, Excell and SPSS 15.0 soft wares were used and Mann-Whitney and Kruskal-Wallis tests were applied. Totally, 73 samples60.9%) were contaminated with coliform and 38 of samples31.6%) contained fecal coliform. There was no significant difference between coliform and fecal coliform p-value=0.086 and 0.212, respectively) in the terms of contamination among the cistern waters fed with tin coverage or iranite coverage roofs. A significant difference was observed between samples of before and after raining and after chlorination the water. The performed tests showd the high degrees of contamination with both coliform and fecal coliform.Therefore, in order to protect the public health, giving the essential information to the people regarding the improvement of the cistern waters and disinfection of water and carrying out the suitable apporaches by regional health authorities are necessary.