biological study of cistern water based on coliform and streptococcus fecalis in golestan province, iran, 2003

background : collection and storage of roof rain water have been practiced for long time ago in iran and many other countries. water of cisterns is usually used as potable water. in golestan province many of rural torkman residents reservoir the most part of their potable water from roof rain in cisterns. in this province there are over 2600 cisterns. methods : to study the water quality, microbiological analysis based on coliform and streptococcus fecalis index in cisterns water reservoir was necessary to recognize the reason of contamination and suitable collection, reservoir and sanitation methods. for this study 69 water samples from the cisterns of the villages were collected and transferred to the laboratory for microbiological analysis during an eight-month period. results : the results of this study showed that coliform in 56%, e.coli in 32%, and streptococcus fecalis in 26% of the collected samples exceeded the drinking water quality standards. conclusions : high pollution of the cisterns could be because of wastewater percolation from agricultural and municipal sources. using water of rivers in dry seasons could be another main reason of the pollution.