Secrets of the Septic System

If your home has a septic system you should know how it works — and how it might fail. Our correspondent provides an explanation.

septic system - full system diagram
The tank is an essential part of the septic system. The two-chamber design shown here is popular because it’s uncomplicated and reasonably effective. However, flooding or overloading the tank can still send undigested material into the drain lines, clogging the absorption field. The latest tank designs have deep holding chambers and internal convolutions to encourage solids to settle out from the flow.