If you are looking to buy a new septic tank or replace your current septic tank, it’s important to be as informed as possible about the different types available and which are the best options for your needs.
A septic tank is the main component of a septic system. This is a self contained sewage system which holds the waste water which leaves your residential property. The waste is held in the septic tank and undergoes a separation process where solids are removed and liquid is filtered into a drainage field.
The waste from a septic tank is generally collected by a professional management company who will take it directly to a sewage treatment plant. The best septic tank for a house depends on a number of factors and there is no ‘one size fits all’ septic tank solution.
Some of the factors that people need to consider when choosing the best septic tank for a house include:
Size of your property
The first thing you should consider is the size available on your property. If you are space-restricted, you will need to find a septic tank that can be installed comfortably and safely on your property. Whereas, if you have plenty of space, you have the option to choose a larger tank. Considering the size of your house and the number of bedrooms, is usually a good indicator of what size tank you will need. Generally, the larger your property, the larger septic tank you will need.
Population of your property
The amount of people living at your property will usually determine how much wastewater you produce. The general rule is that the higher the occupancy of your property, the bigger your septic tank should be. For example, a household of only two people will nearly always require a smaller septic tank than a household of four or five. When establishing how much waste your property produces, you should also take other factors into account like - whether your property has two kitchens, and if you have any efficient low-flow appliances.
Size of the tank
Septic tanks come in all shapes and sizes. Once you have established what size tank your property can accommodate, and how much wastewater your household produces, you can then determine the right tank size for your needs. To get a rough idea, you can use the calculation that septic tanks require a capacity below the inlet level of 2,800 litres (2.8 cubic metres) for up to 5 users. For each additional user, you should increase the size by 150 litres. Getting a septic tank that is too small for your property means that it will be unlikely to cope with the amount of waste water generated. This can lead to serious issues such as blockages and overflowing.
It is important to remember that if you choose a tank that is too small for your requirements, then your system will not be able to effectively manage the volume of wastewater you produce. This can lead to a number of unpleasant problems such as blockages, leaks, and foul odours. However, a septic tank that is too big can also lead to problems, as the system will not be able to work effectively without the right volume of wastewater running through it. It is therefore important to choose the right tank size for your requirements.
Positioning of the tank
Where you plan on positioning your tank, will also affect the size of tank you need. It is important to make sure that your septic tank is positioned somewhere that is clean and safe. It is always best to get advice from septic tank professionals when deciding on the best place to install your tank. Make sure that you consider the following:
- Tree root damage - Tree roots have been known to grow through the walls of septic tanks, leading to leaks and costly repairs. Make sure that you position your septic tank as far away from trees and other plants as possible.
- Vehicle damage - Heavy vehicles driving over the area where your septic tank is installed can lead to high levels of pressure and cause damage to the tank. You should therefore position your tank away from any traffic routes such as driveways.
- Soil quality - Make sure you test the soil quality in the area you are planning on installing your tank. Ideally, you want the soil to be highly absorbent, so it can effectively filter the effluent that emerges from the septic tank. The best type of soil is sandy, undisturbed soil. Make sure you avoid areas of dense clay, as this can stop water flow. Also avoid coarse, gravelly soils that may drain too quickly.
Types Of Septic Tanks
There are several different types of septic tanks to suit different needs and different budgets. Always try to take the time to consider the best tank for you and try to invest wisely as buying a cheaper model may in fact result in issues further down the line.
● Concrete Septic Tanks: traditional septic tanks have generally been made of concrete, brick or stone. These can be durable and affordable, yet they are extremely heavy and can be difficult to install.
● Polyethene/Plastic: these septic tanks are much cheaper and easier to install as they require less space than traditional concrete septic tanks.
● Fibreglass: a fiberglass septic tank will be much more resistant to corrosion than those made from other materials. They are also extremely watertight and light weight.
Design
Just as there have been advancements in the materials used to build septic tanks, the designs have also been improved and expanded over recent years to help optimise function. It is possible to have above ground septic tanks but for now, let’s take a look at the most common options which are usually dug in.
Traditional Design
The traditional septic tank has 2-3 chambers. Waste will flow laterally through the system in 2 main stages:
1. Waste enters the first tank and heavier waste sinks to the bottom
2. Liquids enter the second tank and then are discharged into a drainage field.
Onion shaped septic tank
As you’d expect, these tanks are shaped like an onion and became popular in the 1980s. Generally made from glass reinforced plastic, they are often much cheaper to buy.The onion shaped septic tank’s flow is upwards rather than lateral - this does mean that they need a large area (a big hole) to be installed in. In addition, they need to be concreted in after installation which can add to the overall price.
Shallow dig septic tank
Shallow dig septic tanks operate laterally, just like the traditional brick septic tanks. A shallow dig septic tank is much quicker and easier to install than an onion shaped tank - they require shallower holes and depending on ground conditions they don’t always need to be concreted in.
Pump
A septic tank needs to be pumped out once every 1-2 years (depending on the usage of your home and the water waste generated). The reason for this is that any solids that are not decomposed remain in the tank and must be removed eventually. If the tank is not pumped out, the solids will accumulate leading to blockages or overflow issues
To find the ideal solution for your property, please browse our selection of septic tanks from trusted providers such as Marsh Industries, Clearwater, and Klargester.
