| 英文摘要 |
Efforts to Improve River Water Quality in Tainan: Total Volume Control Plan for San-yei River and Yanshuei River (2023)
The Ministry of Environment (MOE) introduced the "Guidelines for Promoting Water Pollution Total Volume Control" in 2013 to enhance the water quality of impaired rivers through Total Volume Control measures. San-yei River and Yanshuei River are key rivers in Tainan City, with critical monitoring stations at Wangliao Bridge, Wukong Bridge, and Yongning Bridge for San-yei River, and Fenghua Bridge for Yanshuei River. Both rivers have suffered severe ammonia nitrogen pollution, with San-yei River also experiencing past copper contamination, prompting stricter discharge regulations in 2018.
To tackle ammonia nitrogen pollution, the Tainan Environmental Protection Bureau initiated the "2023 Total Volume Control Promotion and Assessment Plan for San-yei River and Yanshuei River." The Plan evaluates the current pollution levels, assesses the feasibility of implementing Total Volume Control, and considers potential impacts on businesses, striving to balance environmental protection and economic development.
1. San-yei River
Pollution Sources:
Ammonia nitrogen pollution mainly stems from domestic sources, followed by industrial and livestock contributions. Current discharge levels reach 897.2 kg/day, with annual average concentrations between 10 and 16.2 mg/L. From January to May 2024, concentrations averaged 16.2 mg/L, reflecting severe pollution. Copper pollution, primarily from industrial sources, has improved significantly, with discharge at 1.05 kg/day and average concentrations below health standards in 2023–2024.
Carrying Capacity Analysis:
Using water quality models, the river's ammonia nitrogen carrying capacity is 593.5 kg/day, while copper carrying capacity is 14.9 kg/day. Current ammonia nitrogen discharge exceeds this capacity, necessitating Total Volume Control measures. Copper discharge remains within acceptable limits.
Recommended Measures (Phase 1):
1.Stricter Discharge Standards: Tighten the ammonia nitrogen standard to 75 mg/L. Existing stricter standards will prevail. The new standard will be enforced two years after announcement, with a three-year extension for businesses requiring facility upgrades.
2.Ban on Ammonium Chloride: Prohibit its use by new businesses and restrict increases by existing ones. A complete ban must be implemented within three years.
Stakeholder Engagement:
Two public workshops in May and June 2024 facilitated dialogue with businesses. Following these discussions, the Plan drafted "San-yei River Basin Ammonia Nitrogen Discharge Total Volume Control Guidelines (Draft)" for the Agency’s review.
2. Yanshuei River
Pollution Sources:
Domestic pollution is the primary source, followed by livestock and industrial activities. Ammonia nitrogen discharge at Fenghua Bridge upstream is 864.2 kg/day, with annual concentrations ranging from 4.7 to 11.7 mg/L. From January to May 2024, the average concentration was 11.7 mg/L, signaling severe pollution.
Carrying Capacity Analysis:
Based on Q75 flow data, the ammonia nitrogen carrying capacity of Fenghua Bridge is 302.6 kg/day, far below current discharge levels.
Recommended Measures:
Livestock Waste Management: Achieve a 90% resource recovery rate for livestock waste.
Discharge Standards for Non-regulated Businesses: Establish standards to prevent unregulated high concentrations.
To minimize economic impact, the Plan suggests phased implementation of these measures, similar to San-yei River’s approach.
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