Investigating the Effect of Pump and On-Site Reservoir Inside Buildings and Major Utilities on Water Quality, Case Study: Water Distribution Network in Tehran Azari District

Requirements of the Issue Sixteen of the Iranian National Building Code demand the protection of the drinking water network inside residential buildings over 4 stories or with more than 10 units. These buildings should aslo be supplied by a storage tank with sufficient amout of water supplying for 12 hours of consumption. Without proper regulations, the implementation of this newly building code may create problems including degradation of on-site water quality. To address this problem partially, this research has been undertaken to evaluate the effect of: incorrect operation on water meter failures, extra repairs may be needed in the distribution network, and the quality of drinking water in storage tanks installed in high-rise buildings. To carryout the objective of this study, regular field inspection of pump and reservoir system was performed, during each in each field observation water samples were collected, and all water samples were analyzed according to the methods specified in the 2005 edition of the “Standard Methods for the Examination of Water and Wastewater”. In addition to the analytical data collected from this study, the existing water quality data from Tehran water and wastewater company were also utilized. All together, routine qualitative tests were performed on 50 on-site reservoir tanks in residential high rise buldings. The results of sampls’ water quality showed that: (i) about 10% of the samples had higher level of heterotrophic bacteria with standard deviation of 56%, (ii) 8% of the samples had concerned level of total Coliforms contamination. In addition, the turbidities of higher than1 NTU in some tanks were observed that may be an indicative of an additional water water quality problems. Aside from water quality problem, direct pumping was made by 4.82% of the users in which this activity significantly contributed to an increased energy costs, water meter failures, and water pressure drops. From the preliminary findings of this study, it has been concluded that there is a potential risk for microbial contamination in drinking water storage tanks and there is also potentials for pump and meter failures and as a results additional requirements for regular maintenance. Because the accurance of these problems are inevidable, it is recommended to development a proper regulatory guidance and enforcement by Tehran’s water and wastewater company in order to protect Public Health safety.