The General Binding Rules Regulations for small sewage discharges from Septic Tanks and Sewage Treatment Plants

New Septic Tank and Sewage Treatment Plant Regulations - GENERAL BINDING RULES

New septic tank rules for small sewage discharges came into force on 1 January 2015. If your septic tank system was installed and in use before 31 December 2014, it is classed as an ‘existing discharge’. If it was installed and in use after that date, it is classed as a ‘new discharge’.

Rules for both existing and new septic tank and small sewage discharges in England

A 'Small Sewage Discharge' is classified as no more than:

  • 2 cubic metres/day (13 people) to ground via a soakaway drainfield
  • 5 cubic metres/day (33 people) to a watercourse. This includes a ditch, but only if it has a flow of water, even a trickle, throughout the year. If it is dry during the summer, you will need a Permit, which we can help to to get.

Septic tanks cannot discharge into ditches, streams, canals, rivers, surface water drains or any other type of watercourse. Under the new Environment Agency General Binding Rules, If you have a septic tank that discharges directly to a surface water (ditch, stream, river, etc.) you must replace or upgrade your septic tank treatment system to a full sewage treatment plant as soon as possible, or when you sell your property.

ALL septic tanks that currently ultimately discharge into watercourses will have to be either:

  • Replaced, using a sewage treatment plant with a full BS EN 12566-3 Certificate, or
  • The discharge to the watercourse must be stopped and diverted to a soakaway drainage field, designed and constructed to the current British Standard BS6297 2007

Your septic tank or sewage treatment plant must meet the British Standard in place at the time of installation

Your septic tank must meet the relevant British Standard in force at the time of installation. The new standards for septic tank systems are:

  • It must have the BS EN 12566-1 certificate for septic tanks installed after 2014. You cannot install a new septic tank that does not have this certification.
  • It must conform with the BS 6297:2007 for drainage fields installed after 2006. No other method of effluent disposal is allowed.

Your septic tank meets the British Standard in place at the time of installation, after 2014 if:

If your septic tank was installed between 1983 and 2014, then it must comply with the 'BS6297 1983 Design and Installation of small scale sewage systems' If before 1983, then this was before any British Standards were in place. Your tank does not have to meet the above standards.

Your septic tank or sewage treatment plant must be the correct size and be installed correctly

Your septic tank or sewage treatment plant must be large enough for the purpose. If you install a new septic tank or drainage field you must insist that the installer makes sure that it is the right size. Please contact us to confirm this.For the Drainage Field, all the necessary 3 stage soakaway drainage field tests must be done to enable the drainage field to be sized and assessed and the results sent to Building Control. Soakaway Crates are not allowed for sewage effluent of any kind.

If you increase the volume of sewage the septic tank receives (an extension or connection to another sewage source) then the septic tank system is unlikely to be big enough. The new volumes must be recalculated to establish the maximum daily volume of discharge. You must then either replace the septic tank and drainfield with a larger system, or install a sewage treatment plant instead.

You also must apply for a permit from the Environment Agency if the new system discharges more than 2 cubic metres (2,000 litres, or 13 persons) a day into the ground. Septic tanks will not normally be allowed for more than 15 persons under the EPP2 regulations.

Your septic tank must be installed in accordance with the manufacturer’s Installation Specifications and the drainage field must be designed in accordance with BS6297:2007

Your septic tank or sewage treatment plant must be regularly emptied and maintained

You must remove the settled sludge in the septic tank before it exceeds the maximum capacity and interferes with the tank's ability to settle solids. This will mean that you should have your septic tank emptied once a year or in line with the manufacturer’s instructions if it is a very large tank.

The tanker company that you use for the emptying must be a registered waste carrier. Ask them, or the tanker driver for a copy of the company’s waste carrier certificate as it is your responsibility.

You must have your septic tank repaired or replaced if it has any of the faults below::

  • Cracked pipes, walls, faulty mortar joints, missing dip pipes, etc.
  • Leaks through pipes or walls
  • Blocked pipes, either going to, in or after the tank
  • Drainage field problems - the septic tank and manholes 'backing-up', soggy areas of ground near the drainage field, pooling water around the tank or soakaway.
  • Smells from the tank or drainage area

Remedial work on your system must be done by a competent person, such as those on British Water’s list of accredited service engineers.

When you sell your property

You must tell the new owner, in writing that they are responsible for a septic tank or sewage treatment plant discharge

This must include:

  • A full description, make and model, of the sewage system and drainage field
  • The location of the tank and drainage field
  • Details of any changes made to the tank or drainage field from the original design
  • Details of the maintenance required for the septic tank or sewage treatment plant
  • Records of maintenance that you have had done to the system. You must keep these for 7 years.

If you stop using the septic tank or sewage treatment plant system

When you stop using a septic tank or sewage treatment plant, all sludge must be removed to prevent any pollution possibilities. This only applies if the septic tank is permanently abandoned, not for holiday absences, empty between tenents, etc.

It should also be filled in with rubble, stone, sand or any other undegradeable material.

Special rules for septic tank and sewage treatment plant discharges in a groundwater source protection zone 1 (SPZ1)

A groundwater SPZ1 is:

  • The area around a commercial water supply (used for drinking water or food production) shown on the Groundwater Source Protection Zones Map. We can check for you. Tel 01759 369915.
  • An area within 50 metres of a private water supply - well, borehole or spring - used for human consumption or bathing. This may be on a nearby property, so ask all neighbours.

You must apply for a PERMIT from the Environment Agency, if you have an existing discharge or are proposing a new discharge to ground in an SPZ1. The permit application fee is £125, but may well be refused. If granted, more conditions to the general binding rules will be added.

The Environment Agency will not grant the permit if there is:

  • Any evidence of pollution
  • The pollution risk is too great

If either of the above are in evidence, the Environment Agency issue an improvement notice and may issue a permit with these conditions met.

The Environment Agency regularly checks:

  • Surface and groundwater quality for signs of pollution from septic tank effluent
  • That your septic system complies with the permit conditions.

Any pollution to surface or groundwater is a serious offence. The E.A. will contact you and may review or revoke your permit. See complying with your permit.

See how to apply for an E.A. permit. Contact the Environment Agency if you need help with your application.

New discharges from septic tanks and sewage treatment plants installed and in use on or after 1 January 2015 - Additional Rules

These additional rules apply if your:

  • New discharge from a septic tank started on or after 1 January 2015
  • Discharge to ground started before 1 January 2015 and you want to install a new drainage field more than 10 metres away from the existing one

Check if there is a local public sewer

You cannot install a new drainage field if any part of the building your sewage system serves is within 30 metres of a public sewer. Instead, you must connect to the public sewer, as the Environment Agency will not allow you to start a new discharge from a septic tank or sewage treatment plant under the general binding rules, if it is possible to connect to mains sewerage..

If the site contains more than one house, then this distance is increased in a linear manner, eg if there are 5 properties then the distance to the sewer will be 5 x 30 metres = 150 metres.

Your local water authority will be able to tell you where the nearest sewer access point is.

Sometimes, it is impossible to connect to the sewer, even if it is close-by. This may be because there is a railway line in the way, or the sewer is already full to capacity, etc In these instances, you must apply for a permit so that the Environment Agency can decide on the best way forward.

Planning permission and Building regulations

You must have planning permission and Building regulations approval for all septic tank installations.

Discharge points in or near designated sensitive areas

There are several special areas that make the installation of a septic tank or sewage treatment plant more complicated.

You will need a permit if the new discharge will be in or within 50 metres of any:

Also, if the development is within Ancient Woodland, you will ned a Permit.

Contact the Environment Agency to check for the above areas..

Click here for the general binding rules

Explanation of terms

septic tank is an underground settlement tank where the solids sink to the bottom, forming a sludge, floating solids and dead bacteria float to the top, forming a crust and the septic liquid flows out to a drainage field.

A sewage treatment plant is, usually, an underground tank that digests the pollutants, producing a discharge that is clean enough to go directly to a stream or other watercourse.

drainage field, also known as an infiltration system, is a series of rigid pipes with holes or slots, placed in trenches, over drainage stone and arranged  in a closed loop design so that the effluent can trickle through the ground for further treatment by soil bacteria.

You cannot use a soakaway (designed for draining rainwater), well or borehole for discharging effluent to ground. If your system includes a soakaway, you must either change it to a drainage field or apply for a permit from the Environment Agency, so that they can assess the risk to groundwater at your site and the risk to groundwater in general.

Rules for Scotland

In Scotland, you must REGISTER a sewage discharge, both new and existing, with SEPA. If it is an existing discharge that has been in use since 1st. April 2006, then you can register it if it is for 15 persons or less. If was in use BEFORE this date, then you can register it if it is for 50 persons or less. For populations higher than these, on the dates above, the you need to apply for a LICENCE from SEPA.

For the full list of sewage and septic tank rules, see

Rules For Wales

You must REGISTER your septic tank or package sewage treatment plant with Natural Resources Wales. It is a legal requirement.

For small scale discharges, it is normally free, subject to circumstance.:

  • If your septic tank or sewage treatment plant discharges into a drainfield in the ground and the domestic property or properties have up to 13 people.
  • If your package sewage treatment plant discharges to a watercourse, and the domestic property or proprieties house less than 33 people.
  • If the sewage system is not near a protected environment, or the groundwater under your land, flows to a water abstraction point that is used for human consumption.
  • For examples of the above, a Site of Special Scientific Interest (SSSI) or a Source Protection Zone for drinking water. Natural Resources Wales will check this when they receive your application.

Rules for Northern Ireland

All sewage treatment plants MUST be capable of achieving a 95% reduction of BOD and usually, 97.5% reduction if they discharge to small streams where the flow rate is lower. Only our Vortex sewage treatment plant is capable of this level of purity.