What is a septic tank?
Essentially it is a compact sewage treatment works where there is no connection to the public sewer network. The purpose of the tank is to retain the solids present in the sewage and to release the treated liquid. The difference between a cesspit and a septic tank is that the liquid is treated by naturally occurring bacteria and discharged through a soakaway whereas a cesspit merely stores the sewage.
How does a septic tank work?
Septic tanks work by letting the liquid form into layers and start to decompose. 50% of the solid waste becomes liquid and then when it rises to the level of the outflow pipe enters the drainage system or soakaway area where the soil absorbs the water and microbes in the soil further break down the waste. All the solids which cannot be broken down remain in the bottom of the holding tank and build up over time.
What is a soakaway?
Soakaways are where the liquid is able to seep slowly into the ground after it has left the holding tank and a group of perforated discharge pipes stretching out under the ground in a drainage field. Commonly occurring problems with soakaways include clogging and soil saturation.
What maintenance is needed?
It is essential that the solid material in the holding tank is emptied regularly, dependent on usage and size of the tank. It is recommended that the tank is emptied on an annual basis. The most common reason for system failure is this build up which blocks the pipes in and out of the tank, can cause sewage backup in the house & overflow of the tank. These problems are often costly to fix, can pose a danger to public health, and are a significant source of water pollution. For this reason it is recommended that a licensed waste carrier is used for regular disposal.
What are some common myths?
You can leave a septic tank for years without emptying
If a tank is left for a period of years, it is likely that you will need expensive specialist equipment to remove the hardened sludge. You may even need to dig out the tank. This can be avoided by having an annual empty and having the tank cleaned every now and then to keep it in good working order.
You are not liable if it overflows
The condition of your septic tank is down to you the property owner. Overflow, blockage costs and environmental impact are all your responsibility.
Your tank completely treats the sewage
Some of the treatment actually takes place when the liquid waste gets into the soil through the soakaway, bacteria in the tank reduces the strength of the effluent and separates the solid particles which build up within the tank until it is emptied.
You can put anything in a septic tank
Harsh detergents and chemicals, fats and oils and solid objects decrease the performance of your tank, unless you want regular visits for us to jet out your system then these few simple guidelines should keep your system in good condition.