After going through the water treatment system, effluents from FEIS-Polyester Business meet the quality standards as replenishment for the cooling tower. The demand for water is high in summer but low in winter, therefore, while the treated effluent is fully utilized in summer, the utilization rate drops in winter. In October 2023, the plant launched a project to purify the effluent through ceramic membranes, RO and ultraviolet disinfection, and use it to supply on-site production. FEIS-Polyester Business invested approximately NT$2 million, and the project conserves 24,000 KL of water annually, equating to approximately NT$510,000 in financial benefits.