Nei Mongol Wastewater Treatment Plant, Horqin Right Middle Banner, Inner Mongolia

The Nei Mongol wastewater treatment plant is located in Horqin Right Middle Banner (科尔沁右翼中旗), a county-level division within the Xing'an League of Inner Mongolia, China. The plant serves a population of approximately 28,000 residents in the urban area of Bayan Huxu Town. As part of China's expanding wastewater infrastructure, the facility contributes to local sanitation and environmental protection. China's wastewater treatment regulations, including the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002), set effluent limits for plants of this scale. For agglomerations serving between 10,000 and 100,000 people, secondary treatment with nutrient removal is typically required to meet Class 1-A or 1-B standards, depending on the receiving water body's sensitivity. It is expected to comply with national standards. The plant discharges treated effluent into local waterways that ultimately drain into the Nen River system, a tributary of the Songhua River, which flows northeast into the Amur River and eventually the Sea of Okhotsk. The surrounding region features a semi-arid continental climate with cold winters and warm summers, and the plant plays a role in protecting downstream aquatic ecosystems from untreated sewage.

The treated effluent from the Nei Mongol plant enters local streams that feed into the Nen River, a major tributary of the Songhua River. The Songhua River flows through northeastern China before joining the Amur River, which empties into the Sea of Okhotsk. This watershed supports diverse aquatic life and provides water for agriculture and industry. The plant's operation helps reduce nutrient and pathogen loads in these downstream waters, which are ecologically sensitive due to seasonal flow variations and ice cover in winter.