Imminent changes to EA discharge regulations could leave you in the stink.

The Environment Agency (EA) introduced new rules regarding the discharge of treated sewage by systems installed and in use on or after 1 January 2015. If you have a septic tank you need to identify whether it discharges to a river or stream (surface water discharge) or whether it discharges to a drainage field, as after 1st January 2020 discharges to surface water from both old and new septic tanks will no longer be permitted by the EA.

If you have a septic tank that discharges directly to surface water you will need to replace or upgrade your treatment system by 1 January 2020.

Where properties (domestic or commercial) with septic tanks that discharge directly to surface water are sold before 1 January 2020, responsibility for the replacement or upgrade of the existing treatment system should be addressed between the buyer and seller as a condition of sale.

It is not uncommon for a septic tank or soakaway to be located on neighbouring land. In these instances, the responsibility to upgrade still lies with the owner of the septic tank whether the soakaway is on their land or not, so it is important to act quickly. The process could be slowed and deadline potentially missed if issues occur during the upgrading process.

If your system requires replacing or upgrading due to its discharge location, you have three possible options:

  • connect to mains sewer
  • install a drainage field so the septic tank can discharge to ground instead
  • replace your septic tank with a small sewage treatment plant

Only small sewage treatment plants can be permitted to discharge to a surface water such as a river or stream.  A small sewage treatment plant (also known as a package treatment plant) treats the liquid so it’s clean enough to go into a river or stream.

It is possible to apply for a permit for discharge to surface water from a septic tank, however these are only granted in exceptional circumstances. It is advisable to contact the EA before applying.

Discharging to ground:

Discharge from septic tanks and sewage treatment system can be made to ground via drainage fields.

Discharge to a soakaway borehole can only be made from a sewage treatment system and must be permitted by the EA. Permits must be applied for in the following circumstances:

if you discharge:

  • to a well, borehole or other deep structure
  • more than 2 cubic meters (2,000 liters) per day

If any part of the building your system serves is within 30 metres of a public sewer, the EA will not allow you to start a new discharge. If there is a good reason why you cannot connect to the sewer (e.g. a river or a hill in the way) then you must apply for a permit from the EA.

More information can be found on the Environment Agency website, or by contacting the EA on:

03708 506 506 or at

H.D. Services Ltd can help!

Treatment plants

Operating for over 35 years, our bespoke HD-SM plant is designed to meet the needs of the individual clients and comply with strict legislation. We provide support and advice in dealing with the EA and can help in securing any necessary permits and/or licences required. We are also approved installers of the Klargester Bioficient range and offer maintenance services to ensure continued compliance with any permits.


Our soakaway boreholes are constructed using the cable-tool percussion method – preferred by the Environment Agency (EA) when drilling the chalk aquifer, and are designed specifically to meet the requirements of the treatment system they are to serve. Our underpinning ethic is that we want to protect the aquifers from which we make our living.

We also construct drainage fields to manage the discharge from septic tanks.

Our portfolio includes the National Trust, RSPB, various county and borough councils, Highways Agency as well as hundreds of domestic clients and estates.

HD soakaway borehole construction design in chalk

For more information on our bespoke systems and services we offer, please either contact us directly by telephone on 01494 792000, by email at or visit our website at