Homeowners with septic tanks that discharge directly into ditches, streams, canals, rivers, surface water, drains or any other type of water course will need to replace or upgrade their drainage either when they sell their property or as soon as possible.

Homeowners are responsible for their choice, installation and maintenance of their wastewater system under a new code of practice introduced by the Environment Agency. They have a legal responsibility to minimise the impact of their sewage waste if they manage it within the bounds of their property e.g. with a septic tank or sewage treatment plant (Binding Rules - England, DEFRA, January 2015).

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

The discharge to the watercourse stopped and diverted to a drainfield, designed and constructed to the current British Standard BS6297 2007

Important Update: 

Under very specific ground or site conditions, reed beds and converters can occasionally be used to comply with the  General Binding RulesKingspan Klargester's reed beds are low maintenance, easy to install, and Building Regulations-compliant. 

Kingspan Klargester are here to help when it comes to the Septic Tank Regulations

Additional Information you need to know as a Septic Tank owner

Sewage treatment plant (also known as a package treatment plant) uses mechanical parts to treat the liquid so it’s clean enough to flow into a river or stream.

Septic tank a septic tank provides a traditional solution to sewage disposal needs for domestic dwellings without access to mains drainage. Installed underground, a septic tank makes use of natural processes to treat the sewage it stores.

Drainage field (also known as a seasonal soakaway) is a system for discharging to water which allows effluent to drain into the ground when levels in the watercourse are low, and into the watercourse when groundwater levels are high

Desludging is the process of removing sediments by draining and cleaning a septic tank or sewage treatment plant. As a minimum, you should have your wastewater treatment system desludged once a year by a registered waste carrier. Kingspan have a team of Accredited Service Engineers, visit Kingspan Service or call 0333 240 6868 for more information.
Your septic tank 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

Your septic tank met the British Standard in place at the time of installation if:

Your septic tank must be large enough to handle the maximum amount of sewage it will need to treat. If you install a new small sewage treatment plant you must check with the installer that it meets the sizing requirements in British Water’s Flows and Loads 4 guidance.

If the amount of sewage the system needs to treat increases (for example, because you’ve extended your property or connected an additional property) you must make sure the septic tank is still big enough. You must also recalculate the maximum daily volume of your discharge and apply for a permit if it is more than 5 cubic metres (5,000 litres) a day.

Your septic tank must be installed in line with the manufacturer’s specification (the instruction manual or technical set of requirements that comes with the equipment).

If you’re in a tidal area (an area where the water level changes according to tides), you must make sure the top end of the pipe that releases sewage is below the ‘mean low water spring mark’.

This is the average low water mark at the time of spring tides. Find out the low water mark where you live on the Admiralty tide tables.

Contact the Environment Agency if your exact location is not shown.

You must get the sludge which builds up in your septic tank removed (desludged) before it exceeds the maximum capacity. We recommend as a minimum, you should have your wastewater treatment system desludged once a year.

The company you use to dispose of your waste sludge must be a registered waste carrier. 

You should have your sewage treatment system regularly maintained in accordance with the manufacturer’s instructions. If these are not available, ask your local maintenance company for advice.

You must have your sewage treatment plant repaired or replaced if it is not in good working order, for example if it has:

  • leaks
  • cracks in tank walls or pipes
  • blocked pipes
  • signs that the effluent is not draining properly (pools of water around the drainage point)
  • sewage smells
  • a failed motor
  • a failed pump
  • a failed electrical supply

Anyone who carries out maintenance on your sewage treatment system must be competent, Kingspan have a team of Accredited Service Engineers, visit Kingspan Service or call 0333 240 6868 for more information.

If you sell your property, you must tell the new operator (the owner or person responsible for the sewage treatment plant) in writing that a sewage discharge is in place.


  • 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, and the maintenance manual if you have one
  • maintenance records if you have them

You must follow these additional rules if you:

  • started a new discharge from a small sewage treatment plant on or after 1 January 2015
  • had a discharge to ground before 1 January 2015 which you now want to change to discharge to a surface water (or the other way round)
  • had a discharge to a surface water before 1 January 2015 and you want to install a new drainage pipe which discharges more than 10 metres away from the existing one or which goes to a different surface water

Check if there’s a public sewer nearby

If any part of the building your treatment plant serves is within 30 metres of a public sewer, the Environment Agency will not allow you to start a new discharge from a sewage treatment plant under the general binding rules.

If you are building a development of more than one property, this distance must be multiplied by the number of properties. For example, if there are 3 properties then the distance will be 3 x 30 metres = 90 metres.

To find out if there is a public sewer near your property, contact your local water company.

If there is a good reason why you cannot connect to the sewer (for example, there is a river or a hill in the way) then you must apply for a permit so that the Environment Agency can decide whether to allow you to use a sewage treatment plant instead. Contact the Environment Agency to find out what information you will need to put in your application.

Building regulations and planning approval

You must have planning permission and Building Regulations approval if you have or are planning to install a new sewage treatment plant.

Check if the discharge point is in or near a designated sensitive area

If you have or are planning to start a new discharge to a surface water in or near to a designated sensitive area, you must apply for a permit.

You will need a permit if the new discharge will be in or within 500 metres of any:

You will also need a permit if the new discharge will be in or within:

  • 200 metres of an aquatic local nature reserve
  • 50 metres of a chalk river or aquatic local wildlife site
Contact the Environment Agency to check if you’re in or near a designated sensitive area and to find out if you need a permit.

Make sure the surface water has flow

New discharges are not allowed to a ditch or a surface water that does not contain flowing water throughout the whole year. That is unless there is a drought or an unusually long period of dry weather.

New discharges to watercourses that seasonally dry up are not allowed under the general binding rules, nor are discharges to enclosed lakes or ponds.

Contact the Environment Agency if you are unsure whether the surface water you want to discharge to is suitable.

Using a partial drainage field - check it meets the requirements

A partial drainage field (also known as a seasonal soakaway) is a system for discharging to water which allows effluent to drain into the ground when levels in the watercourse are low, and into the watercourse when groundwater levels are high.

If you’re using a partial drainage field for a new discharge, you must install it within 10 metres of the edge of the watercourse and you must only use it with a small sewage treatment plant, not a septic tank.

See the full list of general binding rules published by the government.

If there are any rules you cannot comply with contact the Environment Agency to discuss what you need to do.

Rules for Scotland & Wales

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 the 1st April 2006, then you can register it if it is for 15 people or less. If it was in use BEFORE this date, then you can register it if it is for 50 people or less. For populations higher than these, on the dates above, then you need to apply for a LICENCE from SEPA.

For more information on the regulations, see www.sepa.org.uk/regulations/water/small-scale-sewage-discharges/
Rules for Wales
You must REGISTER your septic tank or package sewage treatment plant with Natural Resources Wales. It is a legal obligation.

For small scale discharges, it's normally free, subject to the the following:
  • If your septic tank or sewage treatment plant discharges into a drainfield in the ground and the domestic property(s) have up to 13 people
  • If your package sewage treatment plant discharges to a watercourse, and the domestic property(s) houses 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 more information, see https://naturalresources.wales

Be inspired by some of our case studies:

Talk to us

Our expert, local team is here with professional advice on your sewage treatment project

Click here to submit an enquiry