Separate soil pipe and waste pipe system is known as

Two-pipe system:

This is the best and the most improved method of system of plumbing.

In this system, two sets of separate vertical pipes are laid, i.e.

• One for draining night soil also called as soil pipe
• The other for draining sullage also called as waste pipe or sullage pipe

One-pipe system:

In this system instead of using two separate pipes, only one main vertical pipe is provided which collect night soil and sullage water.

Single Stack system:

The system is a single pipe system without providing any separate ventilation pipe.