The largest-capacity plant in northern Vietnam
The Yen Xa Wastewater Treatment Plant, located in Thanh Liet Ward, Thanh Tri District, was launched in 2013 and officially completed in 2017. The project covers a catchment area of about 4,983 hectares.
It includes a wastewater treatment plant with a capacity of 270,000 cubic meters per day and night, and a sewer system of collection pipes, interceptor sewers, and connecting drains along the To Lich River, Lu River, Ha Dong District, and the new urban areas.
The system has a total length of about 41.362 kilometers, with diameters ranging from 315 millimeters to 2,200 millimeters.
Overview of the event.
The project aims to improve the living environment, natural ecosystems and sanitation conditions in the central urban areas of the To Lich River Basin, the left bank of the Nhue River, and the Lu River Basin.
By developing a drainage and treatment system, it collects and processes wastewater from human activities, thereby supporting sustainable development of the capital.
The plant was constructed directly by the Japanese consortium JFE-TSK, with a cost of nearly VND 3,000 billion (US$118 million). It uses the traditional AO activated sludge method with modern, easy-to-operate, and environmentally friendly equipment.
Its processing capacity is 270,000 cubic meters per day and night, with a maximum of 576,000 cubic meters per day and night during the rainy season, covering 20 inner-city wards.
This is the largest-capacity wastewater treatment plant in northern Vietnam. The project was completed and granted environmental permits for trial operation in December 2024. At present, the plant is officially operating with a capacity of 180,000 cubic meters per day and night, and this is being gradually increased to reach 270,000 cubic meters per day and night.
The sewer system along the To Lich River was constructed by the Japanese contractor TEKKEN at a cost of nearly VND 2,000 billion (US$79 million). It has a scale of over 21 kilometers of pipelines with diameters from 315 millimeters to 2,200 millimeters. Nearly 13 kilometers of the pipeline applied pipe-jacking tunneling technology, used for the first time in Hanoi.
The project was completed in March 2025 and is now channeling wastewater along the To Lich River to the plant for treatment. This is also the first project in Hanoi not to use intermediate pumping stations, allowing wastewater to flow naturally into the plant, which significantly reduces operational, maintenance, and repair costs. In addition, the pipes have advanced Japanese anti-corrosion coatings, which greatly increase the project's lifespan.
Delegates at the event.
A foundation for expanding wastewater treatment projects in Hanoi
Speaking at the ceremony, Vice Chairman Nguyen Trong Dong noted that in recent years, Hanoi has focused on implementing many solutions, mobilizing maximum resources to invest in and complete urban technical infrastructure, particularly in environmental protection.
The Yen Xa Wastewater Treatment Plant is the result of the friendship and close cooperation between Vietnam and Japan, supported by ODA funding and advanced, safe, and modern technology. Notably, it is the first project in Hanoi to apply pipe-jacking tunneling technology.
The project, which began construction in January 2019, is a key component of the Yen Xa Wastewater Treatment System Project. It was designed, constructed, and supervised by Japanese contractors and consultants, and underwent strict quality control and testing on its modern production lines.
Now operational, the plant will help increase the proportion of urban wastewater treated in Hanoi to more than 50%, in line with Program No. 03-CTr/TU of the Hanoi Party Committee, dated March 17, 2021.
This is a large-scale project with systematic investment, from collection systems to treatment and reuse processes, creating a foundation for scaling up wastewater treatment projects across the city.
On behalf of Hanoi's leadership, Vice Chairman Dong expressed his gratitude to the Government of Japan and the Japan International Cooperation Agency (JICA) for their continuous support throughout the implementation of the project.
He also acknowledged and commended the efforts of central ministries and agencies, the determination of the project investor, the dedication of municipal departments and local authorities, as well as the commitment of contractors, consultants, engineers, and workers on site.
"The completion of this project is a testament to more than 50 years of friendship between Vietnam and Japan, and it is also a meaningful gift to the people of Hanoi on this historic anniversary of the nation," Vice Chairman Nguyen Trong Dong emphasized.