Assertion:  People should provide a separate outlet for the scum which is formed in the septic tank.

Reason: The septic tank is a low-cost sewage disposal system where anaerobic bacteria decompose the wastes.

The septic tank is an alternative low-cost method for sewage disposal used in many households. Here, the sewage is allowed to flow into the tank where the anaerobic bacteria decompose the sewage. After decomposition, the lighter material which floats on the surface is known as scum which can be separated through a separate outlet.