Regulation of Private Drainage Systems

On the 6 April 2010 with apparently little fanfare the government introduced new regulations relating, amongst other things, to the discharge of sewage effluent and associated liquids (or presumably solids) from septic tanks, cess pits or other domestic sewage systems which are not connected to the public drainage system and which are not a closed system with no discharge points.

Whilst properties in urban areas will inevitably be connected to the public drainage system there are many areas of the country where connection to the mains, even for new build properties, is not an option (as they are too remote) or was not an option when the property was constructed and which remain on private systems even though the public drainage system has now reached them.

These new regulations apply to and affect any property which is currently served by such a private system and, as one would expect, any new build property which will have a private drainage system when completed.

The regulations in question are the Environmental Permitting (England and Wales) Regulations 2010 (SI 2010/675) made in exercise of powers conferred by sections 2 and 7(9) of, and Schedule 1 to, the Pollution Prevention and Control Act 1999.

The initial obligation is set out in section 12(1)(b) and requires that no-one can cause or knowingly permit a water discharge activity (see below) or a groundwater activity unless they have been authorised to do so by an environmental permit.

Certain types of activity are designated as exempt activities meaning that a permit will not be required, however, registration with the environment agency seems to still be necessary, even if the activity itself is exempt.

Water Discharge Activity

A water discharge activity is, for the purposes of this article, the discharge of sewage effluent into inland freshwaters, coastal waters or territorial waters. (It also includes poisonous, noxious, polluting or waste matter or trade effluent discharge).

So, if your private drainage system discharges into a river, stream or even, perhaps a pond or other body of water you will probably be carrying on a water discharge activity.

Groundwater Activity

A groundwater activity includes the discharge of a pollutant (which is helpfully defined as something that might cause pollution!) that results or might lead to the direct input of that pollutant to groundwater or any other discharge which might lead to the direct or indirect input of a pollutant to groundwater.
Groundwater is any water which is below the surface of the land so would include the water table, underground streams, aquifers etc.

So, if your private drainage system has `weeper` or `finger` drains which discharge into the ground from the septic tank, cess pit or sewage system (whether before or after an internal filtration or settling process) you will almost certainly be carrying out a groundwater activity for the purpose of these regulations.

Permit Requirements

If you are carrying out either a groundwater activity or a water discharge activity the basic position is that you need to have a permit from the regulator (which is currently the Environment Agency) to carry out that activity.

This is the case even if your activity began before 6th April 2010 when the regulations came into force (even if, before that date, no permit would have been required)

However certain types of activity are designated as "exempt" meaning that no permit is required but registration of the activity with the Environment Agency is still necessary.

Exempt Activities

In relation to water discharge activities a small sewage effluent discharge of 5 cubic metres per day or less (according to the EA guidance a domestic property with 8 bedrooms will discharge about 1.8 cubic metres per day) from a sewage treatment plant is exempt. This seems to be because a sewage treatment plant is more sophisticated than a septic tank or cess pit as it is more in the way of a mini sewage works (requiring power and regular maintenance)whereas a septic tank or cess pit is more of a natural process whose discharge is less clean.

In relation to groundwater activity a small sewage effluent discharge of 2 cubic metres per day or less is exempt. This can be from septic tanks, cess pits or sewage treatment plants.

Registration as exempt

There is a positive obligation in the regulations to apply for registration as exempt or, if you are not exempt, for a formal permit to carry out the discharge.

For water discharge activities the obligation to register arose on the 6th April 2010 and, if you are currently carrying out such an activity without a permit or having registered an exemption, you are committing an offence (see below)

For groundwater activities the obligations are slightly less onerous. If your discharge is exempt then you have until 1st January 2012 to register as exempt but if you need a permit the obligation arose on 6th April 2010 and, if you are carrying out a non-exempt activity without a permit you are committing an offence.

You can make an application either online or through the post with the environment agency to register an exemption. For more details please see:


A breach of the various obligations in the regulations can lead to fines of various levels depending on the breach and / or imprisonment so they are certainly not to be taken lightly.

Ongoing requirements

As one would expect in order to maintain an exemption you must ensure that you undertake proper inspection, operation and maintenance of your system, regularly remove excess sludge from the system by a properly authorised contractor and make and keep records of maintenance and repair, which must be kept for at least five years. In addition, the treatment system must not cause pollution.

If you sell or leave the property there is currently no obligation to tell the EA. However, you must pass written details of the exempt discharge onto the new owner. In reality this means passing any and all relevant information to the solicitor dealing with your sale.
You need to tell them that there is an exempt discharge at the property, what it is (e.g a discharge from a septic tank to an infiltration system) and the conditions they must keep to stay exempt. You must also pass on to the new occupier your maintenance records.

Steps to take 

If you are the owner of a property which carries out a water discharge activity then you must take steps to register with the EA now as exempt or obtain a permit if your activity is not exempt as you are already in breach of the regulations.

If you are the owner of a property which carries out a groundwater activity then you have a window of less than a year to take steps to register your system as exempt (assuming that it is exempt). If it is not exempt then you must obtain a permit now as you may already be in breach of the regulations.

Registration as exempt is currently free but if the EA determines that you are not exempt they will suggest that you apply for a permit which does carry a fee.

Posted on: 08/02/2011

This article is for general guidance only. It provides useful information in a concise form. Action should not be taken without obtaining specific legal advice.

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