Chemical and Biological Study of Cistern Water Systems in Rular Areas of Golestan Province

Collection and storage of roof rain water has been practiced for long time ago in Iran. Minoodasht located in the north of Iran-with the population over 260000, has 1366 cisterns in rural area. Water from cisterns is used as the tap water. To study the water quality chemical, physical, and microbiological parameters were determined. In this study, 114 water samples from the cisterns of the villages of minoodasht was collected. 69 cisterns were collected for microbilogical analysis. In 8 months, the samples were studied chemically and microbioloically. Alkalinity and hardness were determined using titrometric method, F, Cl, NO3 and PO43- were determinded using spectrophotometric method, DR-2000 and SQ-300 atomic absorption has been used to determine heavy metals. The results of this study showed that, PO43- in 16%, Fe in 6%, Pb in 69%, Cr in 6% of the water samples were exceeded the drinking water quality standard level.Also the microbial analysis revealed that coliform in 56%, E.Coli in 32% and Streptococcus fecalis in 26% of the collected samples exceed the drinking water quality standards. Highly pollution of the cisterns could be became of wastewater percolation from agricultural and municipal sources. Also water from the river in dry seasons could be another main reason for the pollution.