Background: Kashan rural water and wastewater company (KRWWC) in Iran is facing a multitude of problems including some potential health risks associated with pipe corrosion byproducts, their early deterioration, the occasional interruption of the water supplies and also huge operation costs. Therefore, this study aimed to evaluate the corrosive and scale-forming properties of water in Kashan villages.

Materials and Methods: This descriptive study was carried out on 151 water samples taken from 39 rural water supplies in 4 stages during 2007-9. All samples were analyzed for total hardness, calcium, alkalinity, total dissolved solids (TDS), bicarbonate, temperature and pH according to the last edition of the Standard Methods Book and then Ryznar, Langelier and Puckorius indices were calculated. Data were analyzed using Fisher's exact test and Paired t-test followed by Bonferroni correction.

Results: According to Ryznar, Puckorius and Langelier indices, 95%, 97% and 74% of the water supplies in all seasons were corrosive, respectively. Moreover, according to the three above-mentioned indices, 18 villages (46.15%) under the coverage of Kashan rural water and wastewater company have always had corrosive water and there was also no significant difference in water quality between the seasons.

Conclusion: Results showed that most water supplies are corrosive and a few of them are scale-forming. Hence, application of suitable plumbing utensils, turn on/off bypass pumps and valves and if necessary, appropriate water treatment are recommended.