Septic Tank Facts

Septic Tank

Septic Tank Definition

A septic tank is basically an underground bioactive chamber. It is made of concrete, fibreglass or plastic. It intends to control, manage and most importantly treat waste material. The decomposition is based on anaerobic bacterial reaction. As a result, solids and organics materials reduce to liquid. The water leaves it through the outlet or percolates into the soil. Because of this, septic tanks are more common in areas that do not have a sewerage system connection, such as rural areas. It’s basically a type of biodigester, only that it lacks the functionality of gas collection.

  • Septic tank Design

It has one end connected to an inlet from the toilets and an outlet connected to the drain field. Some septic tank design has 2 chambers while others have 3. A wall with openings between the floor and roof of the tank separates the chambers. As a result, the drainage pipes fill more evenly and preventing premature clogging of the drains, therefore, extending their life. Some septic tank designs include water pumps so as to increase the volume and velocity of water drainage.

A well-maintained septic system is odour-free and requires less emptying. In addition, it should last for decades with no problems.

How a septic Tank Works

A septic tank works in four basic steps. This is:

  • receives the wastewater from the house- all the house wastewater goes to the septic tank in through one inlet.
  • separates the solids from the liquids- The solid waste settles at the bottom of the tank. The wall separating the chambers allows for liquid only to move to the second chamber. The solids materials remain for degrading.
  • decomposes the solids- Bacteria is used to decompose the solid waste to liquid. The bacteria feed on solid waste and free it from pathogens. They further reduce them to water.
  • send the wastewater out to the drain field- the treated waste is released to the ground or left to percolate into the soil. Some tanks may include a pump to assist in pushing water out of the septic system.

Types of Septic Tanks

There are different types of septic tanks. This depends on how they function and how wastewater is treated.

  • Gravity– This type of septic tanks applies the gravity principle to function. The trenches bottom should be 1-1.2m above the water table. In addition, the drainage field should also be below the level of the septic tank. The above water table is used to treat wastewater.
  • Peat Moss System– It uses peat moss in between the pump tank and the field. Wastewater treating happens just before entering the field by the peat. The septic tanks are common in places with shallow soil or high water table.
  • Sand Filter– This is one of the most common types of septic tanks. The tank uses sand to treat the water before it enters the drains. They are best to use where the soil is very shallow.
  • Mound- It is preferable for places where the soil isn’t deep enough. The septic systems have mound filled with sand raised over the natural soil above a drainage field. The water is treatment happens as it percolates through the sand and into the natural soil.
  • Septic Tank Size

The septic tank size varies depending on the type of house and the number of the user. They could be two or more depending on the number of users and the relative amount of water waste. A septic tank is a basic concrete or plastic tank with a capacity of 1000 and 7500 litres.

Septic Tank Construction

A septic tank construction should be perfect to prevent cracking and groundwater pollution. In addition, it should be strong enough to withstand the Earths movements and hold the weight of the waste. Most importantly, it is best to use plastic or reinforced concrete tanks.

A trench is dug and steel is placed where concrete is moulded on both sides to form a 4 inches thick wall. This provides the strength for the tank to hold pressure and also prevent the steel from rusting. The inlet and outlet pipe are put in place before pouring the concrete. It is very important you mix the concrete is well. Add little water to harden the concrete. Use a vibrator to ascertain that it has compacted properly with no air holes or cracks. After that, connect the pipe to the inlet and outlet and also install the manhole slab.

Septic Tank Maintenance

Similar to any other system, a septic tank may become faulty and requires maintenance. The main causes for a septic tank failure include:

  • Too much disposal of grease and cooking oils may cause the drains to block. This is because they are difficult to decompose. It can also result in an odour.
  • None biodegradable waste like condoms, swabs or menstrual products will cause the septic tank to fill up and clog. As a result, do not flush these materials down the toilet.
  • Some chemicals can damage the septic tank components or even kill the bacteria in the septic. This includes inorganic material like paint and solvents, water softener, pesticides among others.
  • Tree roots protruding may plunge and clog the pipes or even worse rupture septic tank. The trees tend to grow rapidly as a result of continuous nutrients supply from the septic system.

Other things that can make a septic tank to fail include high water table, biofilms which develop over time and covering the system with an impermeable surface.

Septic Tank Price

The septic tank price depends on the following:

  • Size of the tank- the size depends on the amount of waste estimate. It ranges from around 6,000 Kshs and above.
  • Human Labor- installing an average tank is about 12,000 Kshs but may be higher depending on the contractor and the labour
  • Materials in use- high-quality materials are more expensive.
  • Location- underground tanks are more expensive unlike above-ground septic tanks
  • Drainage- they are only found in underground septic tanks. Large tanks can include a soakaway and as a result, reduces the cost of emptying.

On average, a septic tank price is about 100,000 Kshs and above. The price rises or lowers depending on the above factors.

Septic Tanks For Sale

Septic tanks for sale are available on e-commerce sites like Amazon and Alibaba or OLX. They sell both brand new and used tanks that are still in good condition. The company or contractor you hire may also provide the tanks to makes it easier for you.

In addition to that, the tanks and all appliances are available locally. As a result, you can easily access septic tanks on sale by checking on Google to see vendors near you.

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  1. It was really helpful when you mentioned that the price of a septic tank is affected by its size. I am wanting to construct a cabin on some property I purchased recently, and I am thinking that a septic system would be good for the plumbing. It’s going to be a small cabin, so I should probably only need a small tank.

    1. Greetings! Hope this finds you you well thank you for contacting Biozone.
      We do modern septic tanks whereby the size is determined by population. For effective communication feel free to call/text/WhatsApp 0796069145

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