The Septic Tank

Taken From Webster's New World Dictionary

Septic Tank
an underground tank for receiving waste matter to be putrefied and decomposed through bacterial action.

The septic tank is the first step of the wastewater treatment process.

The septic tank is the first stop for all wastewater coming from the drains and toilets in your home. bacteria, which are naturally present in all septic systems, begin to digest the solids that settle to the bottom of the tank, transforming up to 50 percent of these solids into liquids and gases. When liquids within the tank rise to the level of the outflow pipe, they enter the drainage system. The effluent then travels through a series of pipes into the drain field where it is further clarified.