How Does a Septic System Work?
Home sewage treatment systems are simple devices for processing domestic wastewater or sewage. They are often taken for granted and misunderstood by homeowners. There are two basic types: those with a simple tank and dispersal field and those that add additional treatment.
How Does a Septic Tank and Leach Field Work?
Sewage flows from your home, by gravity, into the first chamber of a two-chamber septic tank. Solids sink to the bottom, and fats, oils, and grease float to the top. Very slowly, naturally occurring microbes that do not need oxygen start to break down the waste. The waste flows into the second chamber of the tank, where further separation takes place.
- EFFLUENT: Liquid waste that is discharged from a sewage treatment system. Effluent can be untreated, partially treated, or fully treated and can be discharged into the ground, into a ditch or waterway, or sprayed on the ground.
In a septic system, effluent liquid from that settled and separated sewage is discharged through perforated pipes into a designated portion of your property, either into a leach field or a mound. Here, the biological breakdown continues in the soil by bacteria that needs air or oxygen. As the effluent moves and seeps down through the soil, it eventually joins the underground water table or surfaces elsewhere.
- Did you know? About 30% of U.S. homes have a septic or sewage treatment system.
What is Pre-Treatment or Additional Treatment?
Since the Clean Water Act of the 1970s, additional treatment has been added to home sewage treatment systems to help them prevent pollution and reduce discharging pathogens. Most pre-treatment systems use the collection tank and leach field described above but add air to help beneficial bacteria break down contaminants. Some also add filtration and disinfection. There are several options for you to consider in deciding which system will give you the most value while keeping your family safe and your yard beautiful.