Providing sufficient water for industrial usage and managing the produced wastewater are major chemical issues for many companies. Water pinch analysis will design and rectify the system which distributes mass within process equipments that will lead to minimization of fresh water demand and optimization of the regenerated water. Furthermore, whilst combining Oxygen pinch with Water pinch, the oxygen demand will be considered, and the wastewater quality will be dealt with. As a result not only the volume of the used water and resulting wastewater will be diminished, but also the treated wastewater will have a better quality. In this paper, we seek to develop a mathematical model based on water pinch analysis in order to optimize wastewater refining networks so that by considering the impact of multiple restricting pollutants in the network, the wastewater can be minimized and the quality of which can be watched simultaneously. In this study, while considering Arak refinery wastewater network as the case study, attempts have been made to solve and improve the wastewater refining network using GAMS software. The result indicates the prospect of optimal structuring the network in order to reduce the operating costs by 15% in the wastewater treatment plant. In order to credit the proposed case, the level of COD in the process of treatment in Arak refinery has been studied. This will confirm the findings based on the proposed case and contain an innovative method to refine wastewater in Arak refinery. These also prove the potential benefit from minimizing the cost.