How Does A Septic Tank Work?

If you wish to know how a septic tank works, this article should satisfy your curiosity.

Like other parts of a septic system, a septic tank performs a crucial role in the treatment of waste. This component is usually designed to be water-tight and buried below the ground surface.

How A Septic Tank Works

Here, we’ve touched on every area relating to the smooth functioning of a septic tank.

By its design, it’s built to hold organic waste long enough to be treated or digested by bacteria. Although these tanks are meant to perform specific waste treatment roles, they don’t always do so.

Any issue with your septic tank is likely to affect the entire septic system. This needs to be addressed before it worsens. The more the delay, the higher the likelihood of other components developing faults.

Enough of the introduction already! Let’s discuss how a septic tank works.

Types of Septic Tanks

Before we get into details about the workings of a septic tank, it will be necessary to list the types available. This gives you the foundational knowledge to better understand the whole concept.

There are basically five types of septic tanks. They include fiberglass, steel, plastic, concrete, and aerobic septic tanks.

From the names these tanks go by, you’d notice that each type is made of a different kind of material. For instance, steel septic tanks are made of steel.

  • Fiberglass Septic Tanks

This tank septic tank category is made of fiberglass.

With fiberglass septic tanks, you get to benefit from their rust-proof nature. Fiberglass septic tanks won’t crack like their concrete counterparts. Plus, it’s much lighter in weight than most types of tanks and can be easily installed.

Despite its many benefits, a fiberglass septic tank is susceptible to shifting when the soil becomes saturated. Such shifts can cause significant problems.

However, part of the several remedies includes testing the soil type before installation.

  • Steel Septic Tanks

Whenever you buy a steel septic tank, you’re given a 25-year guarantee of rust-free functionality. However, beyond this period, such tanks begin to deteriorate via rust. One thing steel tanks are known for is their durability.

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If you’ve incorporated this tank type as part of your septic system, consider closely monitoring for rusts especially around the cover as well as entry and exit baffles. This allows you to take urgent action to fix any issues arising.

  • Plastic Septic Tanks

Septic tanks made of plastics are also durable, plus, they won’t easily crack. The price point of this tank type is less costly compared to others.

However, extra care needs to be taken when installing plastic septic tanks. It should only be installed by a professional as any unprofessional job will result in the tank floating.

  • Concrete Septic Tanks

If your septic tank is made of concrete, it’s likely to last for as long as 3 to 5 decades. You’re likely to extend its lifespan with proper use. In the event of a crack, a two-way flow of water and waste could flow in and out respectively.

This situation poses a health risk and will need to be addressed as quickly as possible. These are among the heaviest septic tanks you’d find.

This is another type of septic tank that is electric-powered. Such tanks require air supply through compressors to encourage the action of digestive bacteria. Without oxygen, such bacteria would hardly survive or thrive.

Septic Tank Functioning Components

Having listed the different tank types as well as the materials they’re made of, it’s necessary to consider the workings of such tanks.

There are basically two main pipes connecting to the septic tank. One enters from the house into the tank and transports all waste matter.

Such waste matter includes wastewater and fecal matter. The other pipe leading out of the septic tank leads to the drain field. This conveys effluent for filtration in the leach ground or drains field.

The job of the septic tank is to serve as a holding container for all waste collected from the home. The collected waste begins to gradually separate into three phases; the scum (consisting of grease and oils), partially clear water, and the sludge.

  • Scum

The scum layer is always found at the top and consists of grease and oils.

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Oils and grease are usually lighter than water, hence their position at the top layer. Sometimes thick scum layers are a sign of an impending problem. These may even result in clogs.

You’ll need to inspect your scum layer to ensure it doesn’t get too thick. When it does, your septic tank will need to be pumped out. Apart from grease and oils, other scum constituents include soap scum, paper products, and hair.

  • Partially Clear Water

This layer of partially clear water starts just below the scum layer and floats above the sludge layer. This layer is mostly free of solids and is rich in phosphorus and nitrogen which can serve as fertilizers.

This partially clear water is also known as effluent.

When there’s a leakage of your tank, such leakage is likely evident from the lush green grass that’s fertilized by the partially clear water. The partially clear water also holds digestive bacteria that act on the waste matter.

  • Sludge

The sludge layer is usually found at the bottom of the septic tank. This third phase is largely made of solids and is quite thick. Such thickness increases with time as more and more solid deposits accumulate.

Such solids include bones, soil, as well as food particles. This is where digestive bacteria have a field day breaking down such solids into liquid and gases.

What Next After Phase Separation?

We’ve seen that a septic tank plays a vital role in the separation of waste products into three phases; the scum, effluent, and sludge layers. These need to be held or retained for as long as 24-hour for a tank to function properly.

This process ensures that only the effluent leaves the septic tank into the drain field. That way, zero clogging results.

By now, you should have an idea of how your septic tank works. This helps you better appreciate the work done by your tank.

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