This study aims to identify the most suitable water treatment plant among various alternativesu,including,surface Wates, groundwater, RO seawater desalination, thermal desalination (MSF/MED) secondary and tertiary wastewater treatment, industrial, stormwater, and sludge or advanced reuse treatment plants. The evaluation considers key technical, economic, and environmental criteria such as water quality, CapitaLand maintenance costs, energy consumption, environment impact. waste generation, implementation time, operational efficiency, operational risk, and space requirements. The M-polar fuzzy soft set method is applied to systematically handle uncertainty and select the optimal water treatment plant

Keywords: Surface Water Treatment Plants, Operational Efficiency, Optimization, Desalination

AMS Classification: 03E72, 47S40