Septic tanks are an ideal solution for rural households or properties that are suitable for connection to main sewer networks. They provide a variety of benefits for the home and local environment and here we go into more detail about how a septic tank works and much more.

How long does a septic tank last?

There are several factors that will determine how long a septic tank will last. When a septic tank is installed correctly and well maintained, you can usually expect it last anywhere between 20 and 30 years, although it could last for much longer.

Aside from installation and maintenance, how the system is used will also play big role in deciding the tank’s lifespan. Therefore, you need to be aware of the materials that are being put down the drain, as certain substances can damage the tank and connected piping. Avoid flushing things like nappies, baby wipes, sanitary products and chemicals down the toilet, focusing instead on biodegradable items and water wherever possible.

The type of material the tank is made from influences its longevity. For example, steel tanks tend to have the shortest lifespan as they can be susceptible to corrosion. Polyethylene or fibreglass tanks can last up to 30 years, which offers great value for money.

Are septic tanks good for the environment?

A septic tank system is a natural water treatment system, cleaning dirty water that is then released back into the aquifer and resupplying water groundwater resources. In terms of their impact on the environment, septic tanks are good option and, in some areas, offer more benefits than other waste management solutions.

The process recycles water, eliminates waste and naturally replenishes water tables, which is particularly important to note due to the domestic demand placed onto groundwater. Local wildlife and vegetation also benefit from the process.

To remain eco-friendly, a septic tank must be designed and installed correctly. When it is not, it could lead to overflowing sewage or a foul smell, or even to the contamination of surface and groundwater resources, putting the wider public at risk. Hiring professionals for the installation will help to avoid this and routine maintenance is a must to avoid long-term issues arising.

How does a septic tank work?

You can purchase a septic tank as a single or multi-chamber design. The system uses gravity toseparate liquid waste from solid waste that is sent from drains the toilets in your property, before filtering it safely back into the soil.

Once the tank receives the waste it eventually settles into three distinct layers. The ‘scum’ layer at the top contains the lighter solids, including grease and oil. Heavier solids naturally gravitate to the bottom of the tank with is referred to as ‘sludge’. The middle layer contains any remaining liquids that have settled in-between the top and bottom layers and can then flow out of the tank into a drainage field, before finally being discharged into the ground. Naturally occurring aerobic bacteria is then able to break down any remaining waste that is left behind.

For the majority of the time the tank can be left to perform these tasks without any assistance. It’s a good idea to carry out small checks very few months to ensure there are no small problems that could snowball, and you should book in a professional maintenance service every 3-5 years to help maintain optimal performance.

What are the septic tank regulations?

Changes to septic tank installations were last made in 2020. The Environment Agency Septic Tank General Binding Rules altered the regulations to move tank owners away from using soakaways that empty waste into a waterway. Instead, only a drainage field is now permitted.

You should also get in touch with your local authority before installation a septic tank to confirm you are able to install a septic tank. If you are given the go ahead, you will have to apply for a permit – you can find more information about these requirements on the Government website.

Planning permission may also be needed, although In most cases you won’t have to apply, but this should always be checked with local council. Whether or not you will need planning permission, building regulations must be followed during the installation, and this is something that a professional company should already be aware of.  

How much does a septic tank cost?

The two main things to consider when it comes to the cost of a septic tank is the material it is made from and the design type that best suits your garden.

For example, gravity systems that use the existing water flow from pipes tend to be best suited in gardens or land that have rich dirt and soil present. If the ground has a higher level of gravel or coarse soil, it may be better to opt for a pressure system.

In terms of materials, polyethylene and fibreglass septic tanks tend to be the most popular and more affordable. Concrete septic tanks are also available but require more extensive installation work, while polyethylene, for example, is very long-lasting and resilient to changing conditions.

What to do if you are selling a house with septic tank

If you own the property that uses the system, you are classed as the ‘operator’ and are fully responsible for its upkeep. When you are in the process of selling the property, you are legally obliged to inform the buyer about the septic tank, detailing where it is located, how it used, maintenance requirements and up to 7 years of maintenance history.

As you would with any other part of the property, you should be upfront about the septic tank system’s condition and how long it has been installed. For example, if it has been in place for 15-20 years, it could be nearing the end of its lifespan and the selling price may need to be renegotiated to account for the cost of replacing the system. The buyer needs to be made fully aware of the scale of the system they are taken on and the potential cost implications.

Callum Vallance-Poole

Marketing Coordinator - Based at our UK HQ in Banbury, Oxfordshire, Callum is responsible for promoting Water Management Systems, Attenuation Tanks, Treatment Plants, Rainwater Harvesting Systems and more!

Marketing Coordinator - Based at our UK HQ in Banbury, Oxfordshire, Callum is responsible for promoting Water Management Systems, Attenuation Tanks, Treatment Plants, Rainwater Harvesting Systems and more!