Structure of Sewerage

Facilities such as drainage pipes for draining sewage from kitchens and toilets and rainwater that has fallen on the premises to drain pipes. Maintenance will be carried out by everyone. Drainage facilities have the following differences depending on whether the sewer at which the connection destination is a combined or diverted type.

This is a method of combining sewage and rainwater into the sewer with a single drain pipe.

This is a method of separating sewage and rainwater and flowing them into sewage pipes and rainwater pipes, respectively. Don't drain the sewage into the rainwater pipe. In addition, rainwater may flow into a U-shaped ditch.

The area where the sewer has been maintained and the sewage can be treated at a sewage treatment plant is called a "treatment area." Water washing is required for those who own buildings in the treatment area. Washing work refers to the following work.

Installation of drainage facilities for draining water from toilets and kitchens into the sewer must be made without delay after the treatment area. （Article 10 of the Sewerage Law）
If the sewer system is diverted, the drainage system must have a structure that separates the sewage into sewage and rainwater and flows into the sewer. （Sewerage Enforcement Ordinance Article 8）

The toilet must be converted to a flush toilet within three years after it becomes a treatment area. （Article 11-3 of the Sewerage Law）

If a septic tank is used even in a flush toilet, the septic tank must be abolished within three years after it becomes a treatment area. （City Sewerage Ordinance Article 15）
In addition, when we abolished septic tank, we must submit septic tank abolition notice within 30 days. （Article 11-2 of the Septic Tanks Act）

After abolishing the function of the septic tank and cleaning and disinfecting, we will do it in the following two ways.

1. Method of excavating all septic tanks (complete removal)
2. A method of leaving a septic tank as it is and using it as rainwater storage.