What Does a Septic Tank Do?

A septic system has two main parts - a septic tank and a drain field. The septic tank is a water tank box (usually made of concrete or fiberglass) with an inlet and outlet pipe. Wastewater flows from the home to the septic tank through the sewer pipe. The septic tank treats the wastewater naturally by holding it in the tank long enough for the solids and liquids to separate. The solids lighter than water (oil) float to the top forming a layer called scum. Solids heavier than water settle at the bottom of the tank forming a layer called sludge. The middle layer consists of partially clarified wastewater. Bacteria found naturally in the wastewater work to break down the solids in the scum and sludge layers. What can't be broken down by the bacteria remains in the tank until the septic tank is pumped. The clarified liquid flows from the septic tank to the drain field which helps to uniformly distribute the wastewater. A standard drain field (also known as a leach field, disposal field, or soil absorption system) is a series of trenches (or a bed lined with gravel or course sand) buried 1-3 feet below the ground surface. Perforated pipes run through the trenches to distribute the wastewater. The drain field treats the wastewater by allowing it to slowly trickle from the pipes out into the gravel and down through the soil (the gravel and soil act as biological filters).

*To view a diagram or to find your specific septic system you can go to our home page