How do septic tanks help separate sewage?

Answer:
If it is a closed system the septic tank holds the waste water until it is collected.
In an infiltration system, the waste water goes into the tank where the solids settle to the bottom and the liquid portion flows through a gravel bed and into the surrounding earth.

it does not block the drains
Contributor: Mahtaab
First answer by Mahtaab Bhuiyan. Last edit by GregorS. Contributor trust: 293 [recommend contributor recommended]. Question popularity: 1 [recommend question].