Call 0345 0568777

Legislation & Law

2015 wastewater Treatment and Septic Tank Legislation and Regulations in the UK

Manufacturers wishing to market off-mains sewage treatment plants in the UK must be able to provide the BS EN 12566-3 certificate as it was the case before. (The new Standard for packaged sewage treatment units is the EN12566-3 2005 all around Europe, UK included). The CE marking is thus mandatory in the UK. This means that only sewage treatment plants which have the EN 12566-3 Certificate are allowed by the Environment Agency without a permit to discharge. The EN-12566-3 tested sewage treatment plants normally meet the UK Standards.

The ""Permit to Discharge" is not required anymore if the treatment plant serving a property has the EN12566 Certificate. Otherwise you still need a Permit. Note that septic tanks with filter beds are not a sewage treatment plant suitable for discharging effluent to a watercourse: They will indeed never achieve sufficient standards.

The general binding rules are the conditions together with technical requirements  specified by the Environment Agency and apply to anyone who has a septic tank or sewage treatment plant discharging “small” sewage discharges from January 2015.

These rules set out the conditions that septic tanks and sewage treatment plants need to meet in order to be used without an environmental permit.

The new rules are particularly important in the case of a property sold equipped with a septic tank. If you sell a property and the septic tank is operated and maintained properly then it is not necessary to notify the Environment Agency of the ownerships change. However, you must give the new owner the septic system maintenance records.

Reform of the regulatory system to control small sewage discharges from septic tanks and small sewage treatment plants.

Following our discussions with the Environmental Agency, below are the general binding rules for small sewage discharges (SSD's) with effect from January 2015. The following general binding rules apply to all small sewage discharges:

This information about general binding rules is from Department for Environment, Food and Rural Affairs, https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/397173/ssd-general-binding-rules.pdf

General binding rules specific to discharges to surface water:

The discharge must be 5 cubic metres or less per day in volume.
The sewage must receive treatment from a sewage treatment plant.
For discharges in tidal waters, the discharge outlet must be below the mean spring low water mark.

General binding rules specific to discharges to ground:

The discharge must be 2 cubic meters or less per day in volume.
The sewage must receive treatment from a septic tank and infiltration system (drainage field) or a sewage treatment plant and infiltration system.
The discharge must not be within a groundwater Source  Protection Zone 1 or within 50 metres from any well,  spring or borehole that is used to supply water for  domestic or food production purposes.

General binding rules for both discharges to ground AND discharges to surface water:

The sewage must only be domestic.
The discharge must not cause pollution of surface water or groundwater.
All works and equipment used for the treatment of sewage effluent and its discharge must comply with the relevant design and manufacturing standards ie the British Standard that was in force at the time of the installation, and guidance issued by the appropriate authority on the capacity and installation of the equipment.
The system must be installed and operated in accordance with the manufacturer’s specification.

Maintenance must be undertaken by a Competent, Water Insudtry, Contractor.
Waste sludge from the system must be safely disposed of by an authorised person.
If a property is sold, the operator must give the new operator a written notice stating that a small sewage discharge is being carried out, and giving a description of the wastewater system and its maintenance requirements.


The operator must ensure the system is appropriately decommissioned where it ceases to be in operation so that there is no risk of pollutants or polluting matter entering groundwater, inland fresh waters or coastal waters.

For a new discharge, which is one that was started on or after 1 January 2015, the following general binding rules also apply:

General binding rule for both discharges to both surface water AND discharges to ground:

New discharges must not be within 30 meters of a public foul sewer.
For new discharges, the operator must ensure that the necessary planning and building control approvals for the treatment system are in place.
For new discharges, any partial drainage field must be installed within 10 metres of the bank side of the watercourse. New discharges must not be made to an enclosed lake or pond.

General binding rule specific for discharges to surface water:

New discharges must not be in or within: 500 metres of  a Special Area of Conservation (SAC), Special Protection Area (SPA), Ramsar site, biological Site of Special Scientific Interest (SSSI), freshwater pearl mussel population, designated bathing water, or protected shellfish water; 200 metres of an aquatic local nature reserve; 50 metres of a chalk river or aquatic local wildlife site.
New discharges must be made to a watercourse that normally has flow throughout the year.

General binding rule specific for discharges to ground:

New discharges must not bein, or within 50 metres of, a Special Area of Conservation (SAC), Special Protection Area (SPA), Ramsar site,or biological Site of Special Scientific Interest (SSSI), and must not be in an Ancient Woodland.