نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Water meters are among the most important measurement devices and revenue-generating assets of water and wastewater utilities, playing a significant role in recovering part of the costs associated with water production, transmission, and distribution, and consequently contributing to the financial sustainability of these utilities. Determining the optimal timing for meter replacement is of particular importance because premature replacement imposes unnecessary costs, whereas delayed replacement increases economic losses resulting from declining measurement accuracy. Therefore, the primary objective of this study is to determine the economically optimal replacement interval for WMs by balancing replacement costs against the losses associated with measurement errors. Based on the Net Present Value Replacement Chain concept, an economic model was developed to determine the optimal replacement point of WMs. To operationalize the model, a computational tool was designed and implemented in the Python programming environment. To evaluate the model’s performance under real operating conditions, data from all customers of Tehran Water and Wastewater Company, District 4, were analyzed as a case study, and the economically optimal replacement point was determined individually for each customer. This process enabled the assessment of the developed model using data from more than 172,000 customers. The findings revealed that service connection diameter, water consumption level, and the corresponding water tariff paid by customers are the most influential factors in determining the economically optimal meter replacement point. Accordingly, high-consumption customers across all customer categories were identified as the highest-priority group for meter replacement, whereas low-consumption residential customers were assigned the lowest priority, since the economic benefits obtained from correcting measurement errors in this group are insufficient to offset replacement costs. In addition, apparent water losses attributable to meter inaccuracies were estimated at approximately 6.4%. The results further indicated that 70,076 customers require meter replacement, and implementing this replacement program would require an investment of approximately IRR 1,773,610,000,000 (equivalent to approximately 177.4 billion Tomans), expressed in 2024 values. The developed NPVRC-based model is capable of determining the economically optimal timing for water meter replacement while simultaneously considering both technical and economic factors. The Python-based computational tool enables the simultaneous analysis and prioritization of a very large number of customers, transforming the underlying theoretical framework into a practical, real-scale decision-support tool. The proposed model can contribute to improved meter replacement planning, reduction of apparent losses caused by measurement errors, and enhancement of the financial sustainability of water and wastewater utilities. Owing to its flexible structure, the model can also be readily applied to other utilities through simple updates of input data and parameters without modifying the computational framework or decision-making logic.
کلیدواژهها English
