What are the advantages and disadvantages of a split-flow system?

Benefits

• Sewage is separated from rainwater and removed and treated at a water reclamation center, so there is no runoff of sewage into rivers and seas.
• Where existing waterways are available, only sewage pipes can be laid, so construction costs will be reduced.
• The capacity of the sewage treatment facility can be small because it covers only sewage.

Demerits

• When laying two sewage pipes and rainwater pipes, construction costs are higher than that of the combined type, construction costs are narrow and where they compete with underground buried objects in other businesses such as gas pipes and water pipes. Construction is also difficult.
• In the early stages of rainfall, dirt and air pollutants attached to the road surface are washed away and washed away with rainwater into rivers and seas.
• If rainwater or groundwater enters from the joints or manhole of the sewage pipe pipe, or if residential land drainage or road surface drainage is accidentally connected to the sewage pipe, there is a risk that the drainage and sewage treatment capacity of the pipe may be exceeded.