Natural systems are a cost-effective way to clean wastewater from small communities. This paper aims to use an optimization technique to minimize the volume of concrete needed to construct a facultative pond provided within a series of three ponds. A nonlinear constrained optimization model was written and then solved using one of the Add-Ins of MS office. The add-in used was Excel Solver, and the algorithm was generalized reduced gradient (GRG). Before applying the optimization model, wastewater stabilization ponds (WSPs) were de-signed using various configurations and arrangements. The best possible configuration that gave minimum area and hydraulic detention time was selected for the study area. Afterward, the optimization model was applied that further reduced the area by 11.46 %, hydraulic detention time by 11.47%, and concrete volume by 6.94% compared to the traditional approach. In both methods, effluents satisfy the Turkish class-B stand-ards for irrigation. It is recommended that a small-scale application of the model be made to compare the results before applying it on a large scale.