I am working on a healthcare project in Middle East and MEP Consultant suggests to use domestic water for flushing the floor drain out.

The idea of this system - which is not common in Middle East - is to have a mixer at the wash basin domestic water source, one will go to the wash basin tab and the other one will go to floor drain for flushing out and cleaning. Also, the drain of wash basin will go directly to the main drainage system without passing through floor drain pipe.

The common system in Middle East is to connect the drain of wash basin to the floor drain to clean it and then go to the main drainage system.

My questions are the following:

 - What is the baseline of this portion of water that is used to flush the floor drain out?

- Based on your experience, which system is the common system in Healthcare applications?