اولویت‌بندی راه‌بردهای بهره‌برداری پایدار تصفیه‌خانه آب با استفاده از روش‌های SWARA و WASPAS

Abstract
The objective of this study is to identify and prioritize strategies for mitigating adverse environmental, socio-cultural, economic, and technical impacts during the operational phase of the Pardis drinking water treatment plant. To achieve this, key criteria and sub-criteria were first extracted through expert consultation, and their relative importance was determined using the SWARA weighting method. The results of this phase revealed that the environmental criterion holds the highest weight among all evaluated dimensions. Subsequently, to rank the managerial and operational alternatives, the WASPAS multi-criteria decision-making method—an integrated model combining WSM and WPM—was employed. Based on the findings, the establishment of a centralized wastewater treatment system emerged as the most effective strategy for reducing negative operational impacts. This was followed by options such as systematic waste management, implementation of source-based waste segregation programs, and the development of green spaces around the facilities. In contrast, strategies such as installing solar panels and monitoring potential chlorine gas leaks were deemed less significant. The study's findings underscore the pivotal role of infrastructural and macro-level managerial interventions in ensuring the sustainability and efficiency of the treatment plant's operational phase. Technological solutions, while valuable, primarily serve as complementary and supportive measures. Accordingly, integrating both strategic and technological approaches can provide a robust framework for enhancing sustainable operations and minimizing environmental repercussions. 

Extended Abstract
Background and Objective
Water is a vital natural resource that underpins sustainable development. In recent decades, population growth, urbanization, and climate change have intensified water scarcity—particularly in arid and semi-arid regions like Iran. In this context, the sustainable supply of drinking water is not only essential for public health and social welfare but also serves as a foundation for economic growth and improved quality of life.
Urban water treatment plants play a crucial role in ensuring access to safe water. However, their operation often involves environmental, economic, socio-cultural, and technical challenges. Issues such as high energy consumption, pollutant emissions, waste generation, noise pollution, and chemical risks (e.g., chlorine leakage) require targeted strategies during the operational phase.
To address these complexities, scientific and structured decision-making is essential. Multi-Criteria Decision-Making (MCDM) methods have proven effective in evaluating diverse and conflicting criteria. Among them, the SWARA method enables expert-based weighting of criteria, while the WASPAS method—combining Weighted Sum Model (WSM) and Weighted Product Model (WPM)—offers robust ranking of alternatives with improved accuracy and reduced uncertainty.
This study focuses on the Pardis Water Treatment Plant in Tehran Province, aiming to identify and prioritize sustainable operational strategies. Criteria across four dimensions—environmental, economic, socio-cultural, and technical—were defined and weighted using the SWARA method. Subsequently, WASPAS was applied to rank the proposed strategies. The findings provide a scientific framework for enhancing operational efficiency, minimizing adverse impacts, and supporting sustainable water management in Iran.
 
Methodology
The SWARA method is a structured approach for weighting decision criteria based on their relative importance. It begins by identifying independent criteria and ranking them according to expert judgment. The method calculates the relative significance of each criterion, derives coefficients, and determines both initial and final weights using specific mathematical formulas. WASPAS, a multi-criteria decision-making method, combines the WSM and the WPM. It involves constructing and normalizing a decision matrix, calculating the relative importance of alternatives using both WSM and WPM, and then integrating the results to obtain final scores.
The case study focuses on the Pardis and Boumehen water treatment plant near Tehran, chosen for its proximity to Lar and Latian dams and suitable elevation. The plant is designed with a total capacity of 2,500 liters per second, divided into three independent modules. During the operational phase, four main evaluation criteria are considered: environmental, economic, socio-cultural, and technical. A panel of six experts from relevant fields contributed to the analysis. To mitigate negative impacts, several measures are proposed, including creating green spaces, using solar panels, monitoring chlorine leaks, reducing noise pollution, managing waste effectively, and implementing a centralized wastewater treatment system.
 
Findings
The SWARA (Step-wise Weight Assessment Ratio Analysis) method is a structured approach used to prioritize decision-making criteria based on expert judgment. It begins by identifying independent criteria and eliminating those that are dependent. Experts then rank the remaining criteria by importance, calculate their relative significance, and determine coefficients and initial weights through mathematical formulas. The final weights are derived to reflect the true priority of each criterion. SWARA is valued for its simplicity, reduced need for pairwise comparisons, and effectiveness in complex decision environments.
The WASPAS (Weighted Aggregated Sum Product Assessment) method is a hybrid multi-criteria decision-making technique that combines the Weighted Sum Model (WSM) and the Weighted Product Model (WPM). It starts with constructing a decision matrix and normalizing its values. The relative importance of each alternative is calculated using both WSM and WPM approaches, and the final score is obtained by integrating the results. This dual-method strategy enhances the accuracy and reliability of decision outcomes, making WASPAS suitable for evaluating complex options.
The case study focuses on the Pardis and Boumehen water treatment plant near Tehran, strategically located close to Lar and Latian dams. The plant is designed with a total capacity of 2,500 liters per second, divided into three modules. During the operational phase, four main criteria—environmental, economic, socio-cultural, and technical—are used for evaluation. A panel of six experts contributed to the analysis. To minimize negative impacts, several measures are proposed, including green landscaping, solar energy use, chlorine leak monitoring, noise reduction through vegetation and insulation, waste management, and centralized wastewater treatment.
 
Conclusion
This study aimed to identify and evaluate optimal strategies for minimizing environmental, socio-cultural, economic, and technical impacts during the operational phase of the Pardis water treatment plant. Using the SWARA method, key criteria and sub-criteria were weighted, revealing that environmental considerations held the highest relative importance—highlighting the need to prioritize ecological outcomes in management strategies.
Subsequently, the WASPAS method, integrating WSM and WPM approaches, was applied to rank mitigation options. The centralized wastewater treatment system emerged as the top-ranked solution, followed by waste management and green space development. In contrast, options such as solar panel installation and chlorine leak monitoring were deemed less critical.
Overall, the findings underscore the dominant role of infrastructural and managerial interventions in promoting sustainable operations, while technological enhancements serve as complementary measures. A combined approach—emphasizing strategic infrastructure alongside targeted innovations—offers a scalable framework for safe, efficient, and resilient water treatment operations, with potential applicability across similar facilities nationwide.