Guizhou Wastewater Treatment Plant, Guiyang | Serving 220,000 in Guizhou Province

The Guizhou wastewater treatment plant is located in the Huaxi District of Guiyang, the capital of Guizhou Province in southwestern China. Serving a population of 220,000, it is classified as a large urban agglomeration under Chinese wastewater regulations, which mandate advanced treatment for cities of this scale to protect water quality in the region. As a facility in China, the plant is subject to the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002), which sets effluent limits for conventional pollutants and nutrients. For agglomerations serving over 200,000 people, Chinese standards typically require biological nutrient removal to meet Class 1A or 1B discharge limits, depending on the sensitivity of the receiving water body. The plant discharges into the local watershed, which ultimately drains into the Wu River, a tributary of the Yangtze River. The Yangtze River basin supports diverse aquatic ecosystems and provides water for millions of people downstream. Effective treatment at this plant helps reduce nutrient and pollutant loads entering the Yangtze system, contributing to the ecological health of the river and its associated lakes and wetlands.

The plant's treated effluent flows into the Wu River system, a tributary of the Yangtze River, which is China's largest river and a critical freshwater resource. The Yangtze basin supports a wide range of aquatic life, including endemic fish species, and is an important migratory corridor for birds. Downstream, the river passes through densely populated areas before reaching the East China Sea, making nutrient and pollutant control essential for preventing eutrophication and protecting coastal ecosystems.