Water recycling program implementation

Waste water recycling and treatment system 

Recovered rainwater is used for plant irrigation, campus road cleaning, and replenishing ecological ponds

The system uses Rain/Reclaimed water for Toilet Flushing 

Reclaimed water for livestock house washing; digestate applied for farmland fertilization  

Description: 

National Chiayi University (NCYU) has established a comprehensive campus-wide Water Recycling Program as an integral component of its sustainable water resource management policy. The program integrates reclaimed wastewater, livestock reclaimed water, and harvested rainwater into a unified water recycling system for non-potable applications, including landscape irrigation, road cleaning, toilet flushing, ecological pond replenishment, livestock house washing, and agricultural reuse. The program is jointly managed by the Environmental Protection and Safety Management Center and the Office of General Affairs through standardized operation, routine maintenance, water quality monitoring, and continuous performance evaluation, ensuring the long-term effectiveness and sustainability of recycled water utilization. 

The Water Recycling Program consists of three integrated recycling systems. First, general campus wastewater is treated through mixing, coagulation, flocculation, sedimentation, and aeration processes before being stored in Retention Pond P2 (6,900-ton capacity). The reclaimed water is subsequently reused for landscape irrigation, campus road cleaning, and other non-potable purposes, with approximately 2,500 metric tons reused in 2025. Second, wastewater generated from the Animal Research Farm undergoes solid–liquid separation, anaerobic treatment, oxidation, and final treatment before being reused for daily livestock house cleaning, while approximately 3,000 metric tons of nutrient-rich digestate are recycled annually as organic fertilizer for farmland, demonstrating an integrated circular agriculture model. Third, harvested rainwater is collected through multiple rainwater harvesting facilities across the campus. A 148-ton underground storage system beneath Parking Lot No. 6 supplies water for aquaculture and horticultural irrigation, while additional storage systems beneath the College of Science and Engineering garden and the Library raft foundation (974.61 tons) provide recycled rainwater for ecological pond replenishment, landscape irrigation, and toilet flushing. 

Through the integration of reclaimed wastewater, livestock reclaimed water, and harvested rainwater, NCYU has established a resilient campus-wide Water Recycling Program that significantly improves water-use efficiency, reduces dependence on municipal water supplies, strengthens water security, and promotes circular resource utilization. Supported by systematic operation, regular maintenance, and continuous performance evaluation, the program ensures the long-term effectiveness of recycled water utilization while enhancing campus sustainability and climate resilience. These initiatives demonstrate NCYU's long-term commitment to sustainable water resource management and contribute directly to the achievement of SDG 6 (Clean Water and Sanitation), SDG 11 (Sustainable Cities and Communities), SDG 12 (Responsible Consumption and Production), SDG 13 (Climate Action), and SDG 15 (Life on Land).