Skip to content
Homeseptic septic tank & sewage treatment experts

What is the cost of installing a replacement Septic Tank 2023? 

For a FREE quotation for any Septic Tank, Sewage Treatment Plant or Soakaway, replacement or installation, get in contact with us on 0800 3101092 or via our contact form.

What is the cost of installing a replacement Septic Tank 2023? 

Septic Tank Survey Reviews
Call the expert installers on 0800 3101092 to arrange a FREE quote or contact us here.  

Estimating the cost of your Septic installation project?

Okay, first of all, you should consider the possibility of installing a Sewage treatment Plant. Please read the article Should I install a septic tank or a sewage treatment plant? If you are installing a Septic Tank then the system has to be discharging to the ground as a discharge to surface water is illegal via a Septic Tank. 

The Septic Tank itself will likely cost around £1,200, we would recommend using a quality tank as the main cost of a replacement is the installation. If you install a cheap tank then it will likely mean a shorter lifespan. Essentially it is a false economy to save a few hundred pounds on the tank but have to replace it 10 years earlier. An essential consideration at this stage of the project is identifying how big a tank you need.  If you do not know then please read our article What Septic tank size for my house?

The installation element will drive the majority of the cost. If you are just installing a tank and are able to connect to an existing discharge then the cost is going to be around £7,000-£10,000 depending on the size of the tank, ground and access conditions. In reality when a Septic tank replacement is undertaken a new discharge is also added, which will drive additional cost. You should expect to get a full costed quote from your contractor before undertaking any work, thereby removing any risk from overruns or additional issues. If you would like a free quote plese get in touch. 

How Does a Septic Tank Work?

A Septic tank is normally a two-chambered tank (see diagram below) with a gap in the separating wall which allows flow between the two. The First chamber is normally called the settling chamber, waste falls to the bottom and scum to the top. The liquid in the middle flows into the second chamber. The liquid in the second chamber then flows out of the tank to be treated.

It is important to note that the discharge from a Septic Tank is not clean and requires further treatment. This is why from the 1st of January any Septic Tank that discharges directly to a drainage ditch or watercourse will become illegal. All discharges from a Septic Tank post that point will require further treatment either from a drainage field/mound or constructed wetland. If either of these options is not viable then you will be required to install a suitably certified Sewage Treatment Plant.

Septic Tank How it works
What type of Septic Tank Should I buy?

There are several different types of Septic Tank. We generally only look to install modern high-quality plastic or MDPE tanks. We quite like the Graf tank as opposed to the onion designs. However, the choice of the tank can also be influenced by many other factors. These include, soil type and most importantly the depth of the existing inlet pipework. 

How Much Does a Septic Tank Cost?

The cost of a modern Septic Tank is generally between £800 to £1,200. The size of the tank is the key variable in the cost as you would expect.

What Type of Discharge do I need?

A Septic Tank must discharge to ground. They can no longer be used to discharge to a drainage ditch, river or stream. A Septic Tank must discharge to a Drainage field. For a Septic Tank discharge to ground, the Drainage Field must be constructed in a certain way. Please see our article Drainage Field, size calculation and design

If the required design and size of Drainage Field is not an option at your property. A Sewage Treatment Plant should be considered. 

What is the cost of Installing?

The total cost of Installation is highly dependent on the following factors,

1.  Access to the construction area.

2. Size of the Tank

3. Size of Drainage Field needed.

For this estimate, we are assuming that there is a point of access over 2m wide. This point of access can sustain the weight of a 5 to 9-T machine. The tank is designed to cater for a 4-bedroom house. Drainage Field size required is based on a Vp of around 20. Please see our Percolation test guide if you do not know what a Vp is, here. All pipework from the property is complete and connected to a final chamber not more than 700mm deep. This chamber is not more than 10m from the required tank siting.

Based on these parameters you are realistically looking at a total installation of cost around £10k plus VAT. The Drainage fields for these systems are extremely time-consuming to install.

Can I install a Septic Tank on my property, do I need Planning?

If you have never had a Septic Tank serving your property or it is a new build you will need planning permission before installing a Septic Tank. You may also need an Environment Agency permit depending on the site specifics. If you are replacing an existing Septic Tank then this can normally be down without Planning Permission under a repair or replace order, we advise checking with your Local Authority as we have encountered exceptions to this notably in National Parks or with Grade 2 and above-listed properties.

As well as the necessary permissions you will of course need to have adequate space and access for the installation.

Is it still legal to install a Septic Tank?

If your proposed Septic Tank discharges to ground and can do so via a British Standard Drainage Field that complies with BBS 6297:2007 then yes. If your proposed installation discharges to surface water then no you cannot legally install a Septic Tank.

Can I get a grant for a Septic Tank in the UK?

In short unfortunately no. There is no provision currently available from the government for the installation of a new Septic Tank or Sewage Treatment Plant. 

Want to learn more?

We have a large collection of articles containing the answers to all of your questions. Check out our Blog Page 

Homeseptic Ltd. is rated 4.8 out of 5 based on 28

Our reviews on Google
Google Reviews

Our Core Services: The Sewage Treatment expert Installers

On the 1st January 2020, all Septic Tanks that discharge to a Stream, Watercourse or Drainage Ditch will become illegal and will require replacing with a Sewage Treatment Plant. Please see here for more details.

Expert wastewater treatment engineers who specialise in Septic Tank and Soakaway replacements as well as Sewage Treatment Installations. We are based in the New Forest, Hampshire but operate across the South Coast as well as Wiltshire, Somerset, Devon, Sussex, Surrey, Oxfordshire, and Berkshire.

The Home of Septic tank and private drainage system solutions. 

Based in the New Forest, Hampshire on the border with Dorset and Wiltshire we operate an expert team of off-mains drainage specialists. This encompasses Septic Tank, Soakaway and drainage system problems, installations, blockages, and servicing. In addition, any issues relating to cesspits and sewage treatment plants.

Homeseptic offers high quality, professional advice, repairs and installation for all aspects of effluent cleansing and disposal across the south of England. Whether you’re looking for septic tank installation, sewerage treatment plants or systems, piping or soakaway solutions, Homeseptic employs only the most competent engineers in the drainage and treatment industry and knows exactly which solutions suit each property.

We only install and offer quality systems we believe in, from suppliers we know and trust.

New Forest Philosophy

As we have said Homeseptic is based in the New Forest. A great location in between the cities of Southampton, Salisbury and Bournemouth. We are a group of good friends who grew up together in the area.  Individually we all have grown tired of the way other Drainage firms are run. As a result, this is why we set up Homeseptic. If you want to know more please check out our About Page

We want to actually put the customer first and turn up to do a great job that we can be proud of. Unfortunately, this is not the case in the market, with most companies pressuring their workers to sell unnecessary works on a visit. Due to this, we offer upfront quotations with any variations discussed before we start work.

We are honest hard working professionals, which we hope you will agree with. As a result, it will certainly not turn up in flash sales vehicles and give you a load of chat and then do a terrible job. Our team will come with the job in mind and the aim of giving you the best value we can in order to facilitate a quality installation. 

We cover all of Hampshire, West Sussex, Dorset, Somerset, and Wiltshire. Please get in touch and see what you think.

Summary
What is the cost of installing a Septic Tank
Article Name
What is the cost of installing a Septic Tank
Description
We are often asked for rough figures for the installation of a Septic Tank.
Author
Publisher Name
Homeseptic
Publisher Logo
Call Homeseptic