It’s all change on or before 2020!

10th January 2019

General Overview

Below is an overview and points on the general binding rules that have been issued by the government in relation to waste water being discharged to surface water. This only applies if you have a septic tank that currently discharges to a water course such as a stream, river or ditch. 

The following points have been taken from the Government website.

Use the Correct Treatment System

You must use a small sewage treatment plant to treat the sewage if you’re discharging to surface water such as a river or stream. A small sewage treatment plant (also known as a package treatment plant) uses mechanical parts to treat the liquid so it’s clean enough to go into a river or stream.
Discharges from septic tanks directly to surface water are not allowed under the general binding rules.

New rules came into force on 1 January 2015. If your system was installed and discharging before 31 December 2014 you have an ‘existing discharge’. If your system was installed and discharging on or after 1 January 2015 you have a ‘new discharge
Once upon a time, you could discharge the separated waste water from within the septic tank through one of two ways: -

a) To a drainage field or soakaway system – here, the waste water percolates through holes or slots into the pipework, into the surrounding sub-soils.  This provides a form of treatment of the water, and it allows the waste water to disperse safely without causing pollution

b) To a watercourse – the waste water would flow through a sealed pipe straight to a local watercourse such as a stream or a river

So, What’s Changed?

In a nutshell, you can no longer do option b above.  The reason for this is because the `quality’ of the waste water is no longer considered clean enough to flow straight into local watercourses without causing pollution.

If you have a septic tank that discharges directly to a surface water, you will need to replace or upgrade your treatment system by 1 January 2020, or, when you sell your property if before this date.

The discharge must not cause pollution of surface water or groundwater.

This is the Environment Agency’s catch-all clause – if you pollute any water, anywhere, you’re breaking not only the General Binding Rules, but a whole host of laws and regulations, the result of which is that you, as either the property owner and/or the plant operator, can be prosecuted

Your treatment system must meet the right standards

Your treatment system must meet the relevant British Standard which was in force at the time of installation. The standards currently in force for new systems are:

• BS EN 12566 for small sewage treatment plants
• BS 6297:2007 for drainage fields

Have your treatment system regularly emptied and maintained

You must get the sludge which builds up in your sewage treatment plant removed (de-sludged) before it exceeds the maximum capacity. This must be done by a registered waste carrier. As a minimum, you should have your treatment system de-sludged once a year.

If you sell your property - tell the new owner about the sewage treatment system
If you sell your property, you must tell the new owner in writing that a sewage discharge is in place and include the following points

• A description of the treatment plant and drainage system
• The location of the main parts of the treatment plant, drainage system and discharge point
• Details of any changes made to the treatment plant and drainage system
• Details of how the treatment plant should be maintained
• When was the system last de-sludged and serviced

What are the options?

There are two main ways in which you can comply with the new regulations:
1. Swap your septic tank for a sewage treatment plant – sewage treatment plants produce a cleaner form of water, and it’s considered clean enough to discharge straight to a watercourse

2. Install a drainage field or soakaway system – this will take the waste water from your septic tank, and disperse it safely into the ground without causing pollution.


For more information or advice, contact the team on 01283 562382 or email

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