How a septic system works

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What is a septic system?

Septic systems are individual wastewater treatment systems that use the soil to treat small wastewater flows from individual homes. They are typically used in a rural or large lot setting where centralized wastewater treatment is impractical.

There are many types of septic systems in use today. While all septic systems are individually designed for each site, most septic systems are based on the same principles.

How conventional septic system works:

A septic system consists of a septic tank, a distribution box and a drainfield, all connect by pipes called conveyance lines.

Your septic system treats your household wastewater by temporarily holding it in the septic tank where the heavy solids and the lighter scum are allowed to separate from the wastewater. This separation process is known as primary treatment. The solids stored in the tank are decomposed by bacteria and later removed, along with lighter scum, by a professional septic tank pumper.

After the partially treated wastewater leaves the tank, it flows into the distribution box, which separates the flow evenly into a network of drainfield trenches. Drainage holes at the bottom of each line allow the wastewater to drain into the gravel trenches for temporary storage. This wastewater then slowly seeps into the subsurface soil where it is further treated and purified. A properly functioning septic system does not pollute the groundwater.

For more information on the maintenance of your septic system ask your builder or your local health department.