Septic tanks and treatment plants provide essential services to properties that aren’t connected to the main sewer line.
However, if you don’t know what you’re doing the words ‘septic tank’ are sometimes enough to strike fear. But don’t worry, here at TWC Draincare, we have many years of experience in the maintenance of septic tanks and treatment plants, and we have worked with a huge variety of customers (both residential and commercial).
If you want to learn more about the science behind a septic tank, and what you should be doing, look no further, the TWC Draincare team are here to answer some of your questions.
Septic Tank vs Treatment plant vs Cesspit
This is a question we get asked a lot here at TWC Draincare. If there’s an off-mains system installed, no matter what type it is, it will most often be referred to as a ‘septic tank’. However, this may not be completely accurate, so what are the differences:
Cesspit
This is the simplest one to explain. A cesspit is a large, sealed underground tank that collects all wastewater and sewage. Waste collects in the tank but doesn’t discharge anywhere. Instead, the tank needs to be emptied regularly, possibly every few weeks depending on size and use.
Septic Tank
This type of system typically has between 1 and 3 separate chambers for waste. The principle of a septic tank is that the solid waste is separated from the liquid waste using the different chambers. The solid waste remains in the tank and must be emptied, whereas the liquid waste is discharged to the environment (typically via a drainage field).
Treatment Plant
This is a more modern version of a septic tank. The principle is like that of a septic tank, where the solid waste is separated from the liquid waste. Again, solids remain within the tank whilst the liquid waste is discharged, however, a treatment plant is designed to breakdown and treat the wastewater before it is discharged to the environment.
What are the layers in my septic tank?
Most properties will have either a treatment plant or a septic tank installed. Now we understand the base principle, in that these separate the solid waste from the liquid waste we can look at how this works.
If you were to look inside a septic tank (or treatment plant) you would see that the waste breaks down into separate layers.
- Scum layer. This is the top layer of a septic tank. It is made up of lighter floating material, like fats, oils, grease and soap scum. The natural bacteria within the tank will dissolve some of this layer but the rest will remain floating at the top. This layer typically lies above the outlet pipe level meaning it doesn’t get discharged to the environment.
- Effluent layer. This is the middle layer, containing liquid waste. This is primarily made up of water and dissolved solid waste which has been broken down by the natural bacteria within the tank. In septic tanks and treatment plants this layer is discharged from the tank.
- Sludge layer. This is made up of the heavier material that sinks to the bottom of the tank. It is a mixture of solid human waste, food particles and other debris. The natural bacteria within the tank will break some of this down, dissolving it into the effluent layer, but the rest will remain at the bottom of the tank and will need to be emptied out periodically.
FAQ’s
So now we know how they work, here are some of the key questions we get asked about tanks:
“Why do I have a septic tank/treatment plant/cesspit?”
You will most likely have a septic tank because your property cannot be connected to the mains sewer network. This could be because you live in a particularly rural or remote area, or there are limitations in the infrastructure.
“Is my septic tank compliant?”
There are general binding rules that the government has laid out concerning septic tanks, which vary depending on the age and type of your system.
The rules are complex and govern:
- What runs into your system,
- The condition of the system,
- Where the system discharges to and how much can be discharged.
- Where the system is located.
If you are concerned about the compliance of your system, find out more here or contact our team and they can chat you through the requirements.
“If my property has a compliant septic tank/treatment plant/cesspit what are my responsibilities?”
If you have an off-mains system, the overarching responsibility you have is to ensure it is not causing pollution to the environment.
The general binding rules around discharges came into effect on 1st January 2015. These are very detailed and set out the responsibilities of homeowners with off-mains systems.
- Ensuring the system is maintained regularly.
- Ensuring any defects or damage to the system or the surrounding pipework is remediated quickly and effectively.
- Empty the tank regularly (approx. once a year) using a registered waste contractor.
“How do I maintain my septic tank?”
Your septic tank will require regular emptying by a professional — you can contact the TWC Draincare team to book a maintenance visit. Emptying the tank helps to keep the layers in the tank functioning properly by removing excess scum and sludge, which can lead to blockages or contamination of the surrounding groundwater.
If you have a treatment plant, you should also ensure to get this serviced annually. Just like with a car, regular servicing will prolong the life of the system and will ensure that the system is not polluting the environment.
“Is there anything else I should know?”
Yes! Whether you have a cesspit, septic tank or treatment plant, you need to be very careful what you put into it. The systems work best when the natural bacteria within them are kept in balance, enabling waste to be dissolved and broken down effectively. Certain products can prevent the system from working effectively, causing bad smells and pollution.
Here’s a list of some of the things we recommend avoiding:
- Putting food waste, fat, oil or grease down the sink after cooking.
- Pouring paints, solvents, garden chemicals or motor oils down the drain.
- Emptying chemical toilets down the drain.
- Flushing sanitary items such as nappies and feminine hygiene products.
- Harsh cleaning products like bleach when cleaning. Instead, use the eco-friendly brands which do not kill off the natural bacteria.
There is more information available about whose responsibility it is to maintain sewerage on the Citizens Advice website, including both public and private drains.
“Can TWC Draincare help with septic tank maintenance?”
Of course! Our team are fully trained in the maintenance of septic tanks. We are proud to provide a friendly, efficient, and fully guaranteed service. Our engineers will make sure that you are fully informed and confident at every step of the process. We strive to provide helpful, accessible draincare information to our clients — you can check out previous guides we have created on how to tell if your septic tank is full, common septic tank FAQs, and even the types of septic tank that we can provide.
To talk to the TWC Draincare team about your septic tank needs, you can contact us at 0333 305 2243, or fill out our online enquiry form for a free quote.
