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Septic Tank Laws

Under current Environment Agency septic tank regulations, by 2020 many septic tanks had to be upgraded to meet these new requirements. If you have a septic tank that discharges directly into a body of water (e.g. a river, ditch or stream), you are required by law to replace or upgrade your sewage treatment system as soon as possible, or when you sell the property.

What's a Septic Tank?

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. It is an underground wastewater chamber, that’s been designed to settle and retain solids from a property, which sinks to the bottom of the septic tank and the liquid flows out and soaks through to the ground.


How does a septic tank work?

  • Wastewater from your toilets, sinks, showers and household appliances drain into your septic tank.
  • Sewage solids are retained in the septic tank where beneficial bacteria digests the sewage.
  • The resulting sludge needs to be removed regularly by a registered contractor.
  • Liquid effluent containing bacteria, phosphates and nitrates flows out of the tank into your either your percolation tank or percolation are and on into the ground soak away area.


Who is responsible for a septic tank?

If you are an owner or occupier of a property that has a septic tank, then it is your responsibility to ensure that it complies with the most-up-to-date government guideline, and it is repaired when needed.


What do you need to know if you have a septic tank?

You as a homeowner are responsible for your choice, installation and maintenance of your wastewater system under a new code of practice introduced by the Environment Agency. You have a legal responsibility to minimise the impact of your sewage waste if you manage it within the bounds of your property e.g. with a septic tank or sewage treatment.

If you need some advice whether you need to upgrade your septic tank system and the next steps to take, we are happy to help.


Septic Tank Regulations in England

Previously to the General Binding Rules, wastewater from septic tanks was typically discharged into a drainage field or directly to surface water or a watercourse. Under General Binding Rules, septic tanks are no longer allowed to discharge to surface water. Your treatment system must meet the relevant British Standard that 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

You can only use a septic tank conversion unit or a reed bed for discharging effluent to a watercourse under the general binding rules if it meets these requirements. Otherwise, you must either upgrade to a package treatment plant or apply for a permit so that the Environment Agency can assess the risk of using this sort of system in your location. If you apply for a permit you will need to include supporting information to show that the treatment system will treat your sewage to an appropriate standard.

For more information on the General Binding rules click -

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

Septic Tank Regulations in 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

Septic Tank Regulations in 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 following:

  • If your septic tank or sewage treatment plant discharges into a drain field 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

How waste should be discharged from Septic Tanks

There are 3 options for septic tank discharge:

(1) Connect to a main sewer if possible
(2) install a drainage field or
(3) install a sewage treatment plant which treats the wastewater, producing a clear overflow that is environmentally friendly and suitable for discharging.

View our full range of our sewage treatment systems


Whack checks should you do on a septic tank?

If your septic tank system is in good working order you should have the following:

  • Your household drainage should be quick to clear, and toilets should not be backing up
  • There should be no smell from your tank and the cover should be accessible and well fitting
  • The soak away should be dry not swampy, smelly or have prolific grass growth
  • A pale liquid with little or no smell should come from the discharge pipe. It should not be dark, smelly or contain solids
  • Makes sure to keep deep-rooted trees and plants at least 30 m away from your system. Keep the grass nearby short.

If any of the above is showing signs that your septic tank system is not in proper working order, you must get it repaired or replaced by a credited installer.


How often should you empty a septic tank?

Your tank should be emptied once a year so that you do not risk a build up of sludge which can lead to problems with your system. The company you use to empty your septic tank must be registered to do so.

Emptying should be arranged by a registered waste carrier or can be arranged by a reliable company such as RA Dalton


When would I need to register my septic tank?

  • England – No 
  • Northern Ireland – Yes
  • Scotland – Yes
  • Wales – Yes


Is it a landlords responsibility to empty a septic tank?

If you own a property which you rent, or you are a tenant yourself, it can become a little less clear who has the responsibility to empty the septic tank. Maintenance and responsibility can be written into the tenancy agreement. If you are a landlord renting out a property with a septic tank you may need to put measures in place if you want the tenant to take responsibility for the septic tank. You may need an inspection or service after the end of any tenancy period. As a tenant, if it is written into the tenancy agreement that you have responsibility for the septic tank, you might also want to insist upon an inspection to ensure you aren’t inheriting any issues you would then be liable to pay for is one way to do this. Checking the schedule of maintenance and the obligations is another before any serious issues can occur. Following the guidelines of the septic tank is important too.


Do septic tanks need servicing?

You should have your septic tank system regularly maintained in accordance with the manufacturer’s instructions. If these are not available, ask your local maintenance company for advice. This will save costly repairs or replacement of the sewage system in the long term.


Do septic tanks require an environment agency permit to discharge?

If your tank does not comply with the “General Binding Rules” you must apply for a permit. To see the General Binding Rules go to


How far should a septic be away from your house?

Septic tanks should be at least 7 metres away from any dwelling. They should also be located within 30 metres of an access point so that the tank can be emptied.



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