In the last few years, rapid industrial development coupled with globalization have brought about significant environmental impacts from both the industrial and urban settlements. Inadequate treatment and improper disposal of wastewater is a growing problem, causing health hazards and endangering nearby marine life. As such, it is more important to implement a sustainable strategy to reduce the harmful environmental impact of untreated wastewater. Optimizing wastewater treatment operations while tapping into the reuse potential of wastewater can improve the economic viability of a treatment plant. This study presents a mathematical model formulated to optimize the treatment process of wastewater. The model takes into account different input types in terms of quantity and quality, and various output or disposal options. Also, this study introduces the use of different input treatment options – mixed, parallel, and series – to better optimize according to the stakeholder’s objectives. This integrated view of the system from input to output strengthens the model’s capability to meet stakeholder requirements and optimize operations.