News & Info

February 28, 2015
28 Feb 2015

How Septic Tanks Work

Tricel wastewater treatment systemA septic tank is an underground container that holds sewage and allows for the decomposition of that sewage by separating solids from wastewater. When a house or business does not have access to a city’s main sewage lines and system, they may rely on a personal septic tank as a result. The following takes a look at main components of a septic tank, as well as how a septic tank works:

Septic tank basics

A septic tank is usually constructed of polyethylene, concrete, or glass. Resembling a large box, the septic tank has two primary responsibilities: to hold solid and liquid waste, and to separate the solids from the liquids, allowing for solid decomposition. As the septic tank holds the waste, the waste solids will sink to the bottom of the tank, forming the sludge layer of the tank. Simultaneously, oil, grease, and other liquid waste will float to the top of the tank, forming the scum layer.

Leaving the tank

Waste and wastewater flow into the tank from one end, and after the sludge layer has settled, the wastewater will leave the tank from the opposing end. The liquid wastewater is known as the effluent. To prevent sludge and scum layers from leaving as well, and draining into the area referred to as the drainfield, a T-shaped outlet, screens, and other compartments are used as a filter.

The vast majority of traditional septic tanks are powered by nothing other than the natural motion of waste and gravity. Newer tanks, on the other hand, have risers within the tanks. The risers have lids that allow the tanks to be easily pumped, cleaned, or otherwise inspected. This can be especially helpful in the event that a defect in the tank occurs.

Understanding the drainfield

As stated above, liquid waste exists the septic tank and makes its way to a drainfield, where it is then deposited. By percolating through the soil, dangerous bacteria and viruses are naturally removed from the wastewater. If the drainfield is too quickly permeated, though, it may overflow, which can lead to pipeline backups and sewage overflow – a messy and dangerous occurrence.

Septic tanks are extremely important components of the septic system, which are key for waste removal and decomposition. Usually, maintaining a septic tank and system is the responsibility of the property owner where the system is located. If you have questions about your septic tank, speak with a professional today.

Contact Us