If your home is not connected to the main plumbing system, the only way to effectively remove and treat wastewater is to install a waste management system on your property. The two most common systems are: septic tanks and sewage treatment systems. Many people get these two confused and use the terms interchangeably. However, while the two systems are similar, there are a few crucial differences you should be aware of. To help you decide whether a septic tank or sewage treatment system is best for your requirements, we have put together a guide to explain the main differences between the two options.
Uses of a septic tank
A septic tank is an underground settlement chamber that provides a simple treatment process. Heavier solids settle at the bottom of the tank and form a sludge, while other materials float to the top and form a scum layer. Once the process is complete, the sludge and scum can easily be removed from the liquid. The separated wastewater then leaves the tank and passes through a drainage field. This acts as a filtration system which allows the liquid to be absorbed by the ground and receive further treatment by soil bacteria, before rejoining water courses such as canals and streams.
Uses of a sewage treatment system
Rather than just separating the sludge and scum from the wastewater, a sewage treatment system uses a pump to aerate the chamber. The extra oxygen accelerates the natural biological process and encourages the growth of bacteria, that will help break down the harmful materials found in wastewater. The treated liquid can then be safely released directly into local water supplies without the risk of pollution.
Main differences between the two
Although septic tanks and sewage treatment systems are similar, there a few key differences between the two. Below, we are going to look at some of the main differences that you should be aware of.
Purity
A sewage treatment system provides treatment of the wastewater, whereas a septic tank simply separates it. For that reason, a septic tank produces a highly polluting effluent which must be discharged into a drainage field to receive further treatment by the natural aerobic soil bacteria. On the other hand, a sewage treatment system produces a far cleaner, non-polluting effluent which can be safely discharged directly into a local watercourse. A sewage treatment plant is therefore considered the more environmentally-friendly option.
Mechanisms
Septic tanks do not require a power supply for the treatment process. Whereas sewage treatment plants have mechanical components, which means they require a continuous electricity supply to operate. The amount of electricity required varies between systems, so it is worth doing some research before you buy.
Maintenance
Under current regulations, septic tanks do not require servicing, whereas sewage treatment plants require a regular service. It is also worth noting that septic tanks need emptying at least once a year, while sewage treatment systems only need emptying every 3 to 60 months, depending on the type of plant you have.
Capacity
Sewage treatment systems are generally able to handle larger volumes of waste more efficiently. This makes them the most appropriate choice for bigger properties with higher waste needs. Whereas, smaller properties looking for a low-maintenance option may find a septic tank to be a more convenient option.
The new septic tank regulations
Knowing the difference between a septic tank and sewage treatment system, is even more important given the changes in legislation regarding septic tanks, which will take effect at the beginning of 2020. Under the new regulations, septic tanks will be required to meet higher standards and certain types of drainage systems will no longer be legal. Owners of septic tanks will be required to either replace their septic tank with a full sewage treatment system, or upgrade their existing septic tank with a drainage field that has been constructed to meet British Standards. If you are buying a property with its own wastewater system, it is therefore important to know whether the property has a septic tank or sewage treatment system - as you could find yourself with a huge bill to upgrade your system in 2020!
In summary, after considering what each waste system has to offer, it is clear that a septic tank provides a simple way to treat and dispose of wastewater. Whereas a sewage treatment system does a lot more, and offers a more efficient waste treatment, producing a far cleaner effluent that requires no further treatment.
