How Does a Septic Tank Work?

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Are you looking to build in Western North Carolina? If so, during the building process, depending on where you are building,  you will have to decide on whether you will need a septic tank installed or not. If you are building a home farther away from a municipal district, you will be required to have a septic tank. However, you may be wondering, “How does a septic tank work?” Today NC Grading & Excavating is here to help you understand precisely how these systems work.

How Does a Septic Tank Work?

A properly designed septic system can provide effective treatment of household wastewater for a long time. Of course, a septic system needs maintenance, and if it has not been maintained with care, it can instead turn into a costly nightmare, but first, let us learn how these systems work.

Components of a Septic System

There are four main components of a septic system, and they are a pipe from the home or building, the septic tank, a drain field, and the soil.


Whether you are building a home or commercial property wastewater from inside, the structure has to leave somewhere, and this is done through plumbing that connects to a single pipe. This main pipe will then drain into a septic tank.

Septic Tank

A septic tank is a watertight container that is buried in the ground. Septic tanks can be made of materials such as concrete, fiberglass, or polyethylene, but the most important thing is that they do not leak and are watertight.

These tanks hold all the wastewater along with any solids that may be flushed into the container. The pipe that brings the water from the home into the tank comes in via an inlet tee. After the wastewater has arrived, it will then begin to separate with any oils floating to the top, which will collect into scum. Any solids settle into the bottom where they partially decompose into sludge. Any leftover wastewater then exits through an outlet tee, which has a screen into a drain field.

Drain Field

As the separated wastewater leaves the septic tank, it collects into a drain field where the soil can further treat it. The partially treated wastewater is discharged every time new wastewater enters the septic tank.

If your drain field becomes overloaded with too much liquid, it will flood. This flooding will then cause sewage to rise to the surface of the ground, or it can create backups in plumbing fixtures inside your home. Due to this possibility, many states require that you have a reserve drain field system in case your main one fails.

Your Soil Matters

The final component of your septic tank system is the surrounding soil where you build. Nature has created her own filtration system, and septic tanks tie into this. The drain field will percolate the wastewater into the ground, and as it travels deeper, the soil will provide the final treatment needed. As wastewater and even rainwater filter through the natural components of the land, it will remove harmful bacteria, viruses, and nutrients. This purification process cleans the wastewater before it reaches the groundwater sources below the surface.

However, the soil has to be able to handle this step, and the best way to ensure that your septic system is placed in the appropriate area is to hire a professional contractor such as NC Grading & Excavating who can help you determine the type of soil on your property.

When a septic system is designed correctly, it will handle all wastewater from your home or business for a very long time, but they do require maintenance. We recommend that you have them pumped to remove the scum and sludge every three to five years.

If you are looking to install a septic system, soon consider NC Grading & Excavating for your installation. Especially if you are building because we also offer solutions for excavating your land and grading your driveway. We always provide free estimates, so don’t wait; contact us today!

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