Selling a House with a Septic Tank? Homeowners could be in for a Nasty Surprise with New Legislation

5 November 2020 Kingspan Water & Energy
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Homeowners in England need to take immediate action, if they own a septic tank which discharges directly into a water course. 

A recent legislative change is being applied under the General Binding Rules governing private drainage for properties, that cannot connect to the mains sewer for reasons of distance or topography. 

The Rules state that septic tanks in England can no longer discharge effluent directly into a watercourse, and property owners are required to act, either by replacing or upgrading their existing system.  Homeowners will no longer be able to sell their house if their septic tank is not compliant.

The options are either to replace the septic with a sewage treatment plant that carries full BS EN 12566-3 Certification, or to stop the discharge into surface water and divert to a drainage field, designed and constructed to BS EN 6297 2007 (assuming a mains sewer connection was impossible).

There is one caveat.  If the septic tank and its drainage field meet the relevant British Standard that was in force at the time of installation, then the owners may be able to upgrade their system simply by adding a reed bed or a converter although this depends on the ground conditions.

The changes were not widely publicised and it appears that, for many households, the full ramifications are still being digested.

“There’s a lot of confusion out there around the recent changes to the General Binding Rules,” says Dave Vincent, Commercial Director GB, Ireland, MEA & US for Kingspan Klargester.

“Thousands of people have gone to our website to try and understand whether they are affected. We are also offering free advice through a hotline and if there is still any doubt, we would encourage people to have their system checked by a British Water accredited installer, either through our own Service team or one of our Kingspan Klargester Accredited Installers.

“If you are looking to install a new private drainage system, then we always recommend a sewage treatment plant rather than a septic, for complete peace of mind.”

Anyone with a query about their septic tank can go to, email our team on or call the Kingspan hotline on 01296 633033.