Septic Tank Upgrade / Replacement

Upgrade Your Septic Tank before the 2020 Deadline

Under the Environmental Agency General Binding Rules released in January 2015, you will need to take action if you have a septic tank that discharges into a body of surface water such as a ditch, stream or river.

If you own a septic tank, you must replace or upgrade it to a full sewage treatment plant by 1st January 2020. If you’re planning on selling your property, you’ll need to ensure this work is carried out before to ensure the sale can go through.

Additionally, if the Environment Agency finds your septic tank is causing pollution, you’ll be required to upgrade or replace your septic tank sooner. 

If you’re concerned about how these changes will impact you, Mawdsleys Pumps can help. We can talk you through your options and guide you through the process towards compliance. For more information, call us today on Bristol: 0117 955 2481.

Why Are The New Regulations Coming Into Place?

One of the most common ways of discharging waste from a septic tank is into a watercourse; this is generally a local stream or river. The Environmental Agency has now determined that the quality of this wastewater from these septic tanks is not fit to be discharged without causing pollution.

A sewage treatment plant produces water that is clean enough to discharge straight into a watercourse without the risk of pollution.

How to Ensure Compliance

There are a number of ways in which you can ensure compliance with the new requirements before the 2020 deadline:

  • Replace your current septic tank with a sewage treatment plant (also known as a package treatment plant) that meets the required British Standard.
  • Install a drainage field system that meets the required British Standard.
  • Upgrade your old septic tank to one that can treat water to the same standard as a sewage treatment plant.
  • Connect to a mains sewer system instead.

Sewage treatment installation maintenance and repair

Rules for New Treatment Systems

Under the General Binding Rules, you must ensure that your new drainage field or sewage treatment system meet the relevant British Standards that were in place at the time of installation. The standards currently in place are:

  • Septic tanks and small sewage treatment plants – BS EN 12566.
  • Drainage fields – BS 6297:2007.

Additional Rules for Treatment Systems Installed After 1st January 2015

In addition to the rules above, the following applies if:

  • Your discharge from a septic tank or small sewage treatment plant started on or after 1st January 2015.
  • You had a discharge to the ground before 1st January 2015 which you now want to change to a discharge to surface water or vice versa.
  • You had a discharge to the ground before 1st January 2015 and you want to install a new drainage field more than 10 metres away from the existing one or which goes to different surface water.

Under the additional rules, you will need to ensure:

  • You have Planning Permission and Building Regulation approval before the installation of a new sewage treatment plant.
  • There is no public sewer within 30 metres of the building your treatment plant serves.
  • The discharge point is not in or near designated sensitive areas such as areas of conservation.
  • The surface water has a flow.
  • If using a partial drainage field, you’ll need to ensure it meets requirements.

Find out more about the additional rules for treatment systems installed on or after January 1st 2015 here.


What does a drainage field system do?

A drainage field system (also known as an infiltration system), allows the septic tank to discharge water into the ground as opposed to into a body of water.

What if I plan to sell my house?

If you’re planning on selling your home and your septic tank discharges into an open body of water, you’ll need to upgrade or replace the system before the sale can go ahead; this should be addressed as a condition of sale between the buyer and seller.

How do I know if my treatment plant met British Standards?

If your treatment plant has a CE mark, has a certificate of compliance with a British Standard or is on British Water’s list of approved equipment then it met the British Standard in place at the time of installation.

If you have a septic tank that was installed before 1983 (before any British Standards were in place), your tank does not have to meet the above standards.

How often should I de-sludge my treatment plant?

As a rule of thumb, you should have your plant de-sludged at least once a year or before it exceeds its max capacity.

Do I need Planning Permission for a new treatment plant?

Yes, in order to install a new sewage treatment plant after 1st January 2015 you will need both Planning Permission and Building Regulations approval. Generally speaking, your installer will source these on your behalf.

What should I do with my old septic tank?

To prevent any pollution, an old septic tank should be de-sludged and properly disposed of. In any case, a professional should do this on your behalf.

How do I upgrade my old septic tank?

In some cases, it’s possible that a septic tank can be upgraded instead of being replaced entirely. In these instances, you will be asked to provide evidence that is will treat water to the same standard as a sewage treatment plant. You should contact a professional pump engineer to find out if your septic tank can be upgraded.

Talk To the Experts

If you’re unsure whether or not you’re compliant with the General Binding Rules or need advice on upgrading or replacing your septic tank, we can help. For more information give one of our expert team a call today on Bristol: 0117 955 2481 or fill out a contact form and we’ll get back to you.