What are regulations on wastewater collection and drainage structures of urban areas and residential areas in Vietnam?

Pursuant to Article 5 of the Circular 15/2021/TT-BXD (takes effect from 10/02/2022) stipulating regulations on wastewater collection and drainage structures of urban areas and residential areas in Vietnam as follows:

- Combined sewer overflows on common water drainage system:

+ Rely on water drainage situations, geology, terrain, and hydrography characteristics to determine construction location of combined sewer overflows. Construction location of combined sewer overflows must ensure accessibility during management, operation, and supervision of the structures and convenience in discharging rainwater into receiving waters and not affect other technical infrastructures;

+ Management and operation of combined sewer overflows must comply with designed management and operational procedures approved by competent authority;

+ Combined sewer overflows must be dredged, preserved, and maintained regularly in order to guarantee normal operation.

- Collection sewers for transporting wastewater to treatment plants:

+ Location and depth of installation of collection sewers must guarantee convenience in managing operation and compliance with national technical regulations on technical infrastructures serving water drainage;

+ Diameter, velocity, and slopes of wastewater collection sewers must be calculated and examined in order to guarantee rate of wastewater collection and transport to concentrated treatment plants and prevent from leaking;

+ Collection sewers must be durable, sealed, and stable under weight, natural conditions, and corrosive effects of the environment during use period.

- Post-treatment wastewater discharge gates leading to receiving waters must be installed in appropriate areas so that wastewater can mix with receiving waters and not cause bank erosion or affect surrounding scenery, other structures and traffic activities.

- Manholes of wastewater discharge gates must be installed in appropriate locations to allow access, inspection, control of discharge sources, and water sampling when discharging into receiving waters.

- For common water drainage systems that are regulated by detention basins, rainwater must first pass combined sewer overflows prior to entering detention basins. Water storage and regulation performed by detention basins must guarantee regulation of rainwater.

Best regards!