A septic system is a series of pipes, structures, and components used to dispose of household waste-water within the underground soils of the house's lot. Septic systems are used where connection to municipal sewers is not available. When installed according to Connecticut's code they are environmentally-friendly and prevent the health hazards associated with sewage runoff.
Follow a flush for a moment: The waste-water flows through the interior plumbing to the foundation wall where it enters a 4" (interior diameter) pipe called the soil line or building sewer. From there it travels by gravity to a water-tight structure called the septic tank. The soil line and tank are provided with air through the building's vent pipe, which extends though the roof and keeps your draining sink from saying "glub - glub".