Septic 101: How A Septic System Works

Today, one in five households in America still rely on a septic system for their wastewater treatment. Every year more than 400,000 septic systems are installed in America. Even with such a large presence, many septic system owners know little about how their system works for them. Since we at Speedy Septic are passionate about education, we created our Septic 101 pages with these owners in mind. In the following 9 articles you’ll learn what a septic system is, how it works, the installation process, and how to maintain a septic system.

A septic system is an onsite wastewater treatment alternative to hooking up to city sewer. Most septic systems are found in rural or suburban areas, though there are still some septic systems within city limits. In the most common, gravity fed septic system, water and sewage from household fixtures and appliances, like a kitchen sink, are carried from the house to the septic tank all by gravity and through a series of pipes. The sewage and wastewater flow into the septic tank where they settle and separate into three layers; the scum layer, the effluent layer, and the sludge layer. These layers are important as a traditional gravity fed septic system is built to only extract the middle watery effluent layer and carry the effluent to the drainfield to be treated by the soil. The scum and sludge layers, at the top and bottom, are naturally treated by the good bacteria in the septic tank and should be pumped out regularly by a septic system maintenance provider when necessary.

In most traditional gravity fed septic systems, the effluent goes from the septic tank into the drainfield by first going through an outlet line from the septic tank to a distribution box or drop box. The distribution box distributes effluent to the drainfield pipes. The drainfield is made up of trenches with perforated pipes, where effluent seeps from the holes in the pipes into the ground to be purified by the soil. Effluent is then taken up by the plants above or enters the ground water below.