A septic system is a catch basin for all the solid and liquid waste that is collected from a home’s drains and toilets. Each time you wash your hands at the bathroom sink, wash dishes in your kitchen sink, take a shower, or flush the toilet, wastewater drains from your house into a tank that makes up a septic system. For houses that are not serviced by public sewers, homeowners must install a septic system to trap, treat, and dispose of wastewater.
Septic systems must be well-maintained in order to function properly and to provide reliable service for years to come. Poorly functioning systems can cause property damage, pollution, and even disease. Though a significant financial investment, a well-constructed system is a necessity for any homeowner or property owner, especially if he plans to sell his home in the future.
Main Parts of a Septic System
A typical septic system consists of three parts.
- The tank or septic tankIn a typical home, a septic tank may be constructed of concrete or steel and can hold about 1,000 gallons of water. It is buried near the home, and wastewater drains into and collects within it. There are three layers in a typical septic tank. The first is the scum layer, composed of anything that floats. The bottom layer is called the sludge layer, where waste that is heavier than water sinks. The middle layer may look fairly clear, but this is where bacteria and toxic chemicals reside.
- The drainfieldThe liquid or middle layer of the septic tank contents flow to the drainfield. As new wastewater enters the septic tank from the house, old water is released through a series of perforated pipes that are typically 4 inches in diameter. These pipes are buried in a trench 4 to 6 feet deep and filled with gravel.
- The soilThe drainfield drains into soil below. Wastewater that drains into the soil is treated by microorganisms then seeps through the ground and into surface water. The soil must be made of an even mixture of clay and gravel in order to treat wastewater effectively.
Putting it all Together
As wastewater leaves the sink, toilet, or shower stall, it passes through a series of pipes that drain to the septic tank. This wastewater flows into the tank and forces the water that has been collected there out into the drainfield. Feces flushed from the toilet will sink in the tank, while the liquid part will drain into the drainfield. Gravity pretty much does all the work in a typical sewage system. Toxic gases are released, as organic material is broken down. These gases pass from the tank through a vent pipe that reaches up to the roof of a house.
Septic-tank maintenance includes collecting the sludge that has accumulated in the bottom of the tank and checking on the function of the drain field pipes and pipes that run from the home’s drains to the septic tank. A professional contractor should do this periodically.
