Effect of Water Stagnation in Households Pipes and Tanks on Drinking Water Quality (Case Study: Some Areas in Tehran)

Document Type : Technical Note

Authors

1 MSc Student of Hydraulic Structures, Payame Noor University, North Tehran Center, Tehran

2 Ass. Prof., Faculty of Civil, Water and Environmetnal Engineering, Shahid Beheshti University, Tehran

3 Lecturer, Faculty of Civil, Water and Environmental Engineering, Shahid Behesthi University, Tehran

Abstract

The water quality in distribution networks is regularly monitored on a routine basis. However, the quality of water in pipes and tanks inside buildings is rarely ever inspected. This study investigated the overnight stagnation of drinking water in household taps and building tanks. For the purposes of this study, the Heterotrophic Plate Counts test was conducted for which water samples were taken from 25 different buildings located in different parts of Tehran, among which 11 buildings had water storage tanks. The results showed a considerable increase in bacterial concentrations in all the water samples after stagnation. The results of bacterial enumeration in water tanks indicated that although building tanks reduced the quality of the stored water, bacterial concentrations in water tanks were still below the standard limit.

Keywords

Main Subjects


1. Lautenschlagera, K., Boon, N., Wang, Y., Egli, T., and Hammes, F. (2010). “Overnight stagnation of drinking water in household taps induces microbial growth and changes in community composition.” J. Water Research, 44(17), 4868-4877.
2. Haider, T., Haider, M., Wruss, W., Sommer, R., and Kundi, M. (2002). “Lead in drinking water of vienna in comparison to other european countries and accordance with recent Guidelines.” Int. J. Hygiene and Environmental Health, 205(5), 399-403.
3. Zietz, B. P., de Vergara, J. D. and Dunkelberg, H. (2003). “Copper Concentrations in tap water and possible effects on infant’s health-results of a study in lower saxony, Germany.” J. Environmental Research, 92(2), 129-138.
4. Zietz, B. P., Lass, J. and Suchenwirth, R. (2007). “Assessment and management of tap water lead contamination in lower saxony, Germany.” Int. J. Environmental Health Research, 17(6), 407-418.
5. Servais, P., Billen, G., Laurent, P., Levi, Y., and Randon, G. (1992). “Studies of BDOC and bacterial dynamics in the drinking water distribution system of the Northern Parisian suburbs.” J. of Water Sceinces, 5, 69-89.
6. Kerneys, A., Nakache, F., Deguin, A., and Feinberg, M. (1995). “The effects of water residence time on the biological quality in a distribution network.” J. Water Research, 29(7), 1719-1727.
7. Niquette, P., Servais, P., and Savoir, R. (2000). “Impacts of pipe materials on densities of fixed bacterial biomass in a drinking water distribution system.” J. Water Research, 34(6), 1952-1956.
8. Mallevialle, J., and Suffet, I. (1987). “Identification and treatment of tastes and odors in drinking water.” AWWA Research Foundation, Denver, CO, USA.
9. LeChevallier, M. W., Welch, N. J. and Smith, D. B. (1996). “Full-scale studies of factors related to coliform regrowth in drinking water.” J. Applied and Environmental Microbiology, 62(7), 2201-2211.
10. World Health Organization (WHO). (2006). Guidelines for drinking - water quality, 3rd Ed. WHOC, Geneva, Switzerland.
11. Jalili Ghazizadeh, M. R., Moloudzadeh, N., and Salehi, S. (1999). “Methods of peak consumption reduction in water distribution networks.” National Congress of Civil Engineering, Tehran University, Tehran.(In Persian )
12. Pepper, I. L., Rusin, P., Quintanar, D. R., Haney, C., Josephson, K. L., and Gerba, C. P. (2004). “Tracking the concentration of heterotrophic plate count bacteria from the source to the consumer’s tap.” Int. J. Food Microbiology, 92(3), 289-295.
13. Wanga, W., Edwardsa, M., Falkinham, J. O., and Prudena, A. (2012). “Molecular survey of the occurrence of Legionella spp., Mycobacterium spp., Pseudomonas aeruginosa, and Amoeba Hosts in Two chloraminated drinking water distribution Systems.” J. Applied and Environmental Microbiology, 78(17), 6285-6294.
14. Iran Industrial Investigation Standard Organization. (1999). Water-culturable micro-organisms count, Standard No. 8-5271, Tehran, Iran. (In Persian)
15. Country Water and Wastewater Co. (2005). Instruction for heterotrophic plate count bacteria in water, 1st Ed., Utilization Department, Iran, (In Persian).
16. Bartram, J., Cotruvo, J., Exner, M., Fricker, C., and Glasmacher, A. (2003). Heterotrophic plate counts and drinking-water safety, IWA Publishing on Behalf of World Health Organization (WHO), London, UK.
17. Chen, L., Jia, R. B., and Li, L. (2013). “Bacterial community of iron tubercles from a drinking water distribution system and its occurrence in stagnant tap Water.” J. Environmental Sciences: Processes and Impacts, 7, 1332-1340.