Water course

Septic Tanks and Small Sewage Discharges

Septic tanks in England can no longer discharge untreated sewage into a watercourse. If your discharge causes pollution it may be considered an offence and can result in the Environment Agency taking enforcement action against you.

The Regulations

In 2015, the General binding rules for small sewage discharges were announced, aimed at those who discharge their sewage either into the ground or to surface water.

For those that have such sewage discharges, they must do the following before 1 January 2020:

  • Work out your discharge amount with the discharge calculator
  • Read and follow the General Binding Rules
  • Check whether you have an existing discharge (a system installed and discharging before 31 December 2014) or a new discharge (system installed and discharging on or after 1 January 2015). New discharges have extra rules they must follow.
  • Find out if you’re in a Source Protection Zone (SPZ)
    • Click the link above to the DEFRA magic map and search for your location in the top left
    • Click the tick box for ‘Designation’”, then the + on ‘Land-Based Designations’
    • Click the + on ‘Non-statutory’ and click the tick box for ‘Source Protection Zones’
    • If your area highlights in red, it is in an SPZ and won’t meet the General Binding Rules
  • Update or change your sewage management system to follow the rules
  • If you are unable to follow any of the rules, apply for an Environmental Permit

The ‘General binding rules: small sewage discharge to a surface water’ regulations were also announced, giving owners of septic tanks that release liquid into surface water until 1 January 2020 to make the necessary changes to comply.

The reason for the regulations is to prevent pollution and ensure that sewage is properly disposed of.

Who is affected?

If you own a septic tank to get rid of your sewage, then the regulations apply to you. Rural properties are more likely to have septic tanks as they are sometimes unable to connect to a public sewer.

If your septic tank discharges into a watercourse, then it must also follow the new regulations.

What are the changes?

If your septic tank currently releases untreated sewage into a watercourse, then you must change your sewage management to prevent this. You can do so in three ways:

  • Connect to a public/mains sewer (if possible).
  • Install a drainage field/soakaway to discharge the wastewater into the ground instead.
  • Install a sewage treatment plant instead of a septic tank to allow the water to be treated before being discharged into a watercourse.

Watercourses and surface water

You can discharge into a watercourse, but only if you are using a sewage treatment plant to do so. The following are all considered to be watercourses:

  • River
  • Brook
  • Beck
  • Ditch
  • Stream
  • Leat
  • Goyle
  • Rhyne
  • Culvert

New discharges (systems that are installed after 1 January 2015) cannot be installed on surface water that doesn’t contain flowing water throughout the year, or watercourses that seasonally/regularly dry up, unless there happens to be a drought or an unusually long period of dry weather.

Discharges are also not allowed into enclosed lakes or ponds; there must be flowing water throughout the year.

Connecting to a sewer

If you wish to connect to a public sewer, you must first check with your local water company to see if there is one nearby. You must then apply and pay for your property to be connected to the sewer system through your local water company.

If a public sewer is within 30 metres of the part of your property that is served by your current treatment system, then you will not able to start a new discharge and may have to opt to connect to the public sewer instead.

Installing a drainage system

If you are planning on keeping or installing a septic tank, then you will have to install a drainage system. This allows the wastewater to be safely dispersed into the ground and prevent pollution.

You must ensure you install a system that meets the British standard of BS 6297:2007 and be sure to use professionals who will install the correct system.

If you plan on using a partial drainage field or seasonal soakaway (which discharges water into the ground when the watercourse levels are low) then this must be used in conjunction with a sewage treatment plant, not a septic tank.

Installing a sewage treatment plant

If you intend to discharge your wastewater into a watercourse, then you must install a sewage treatment plant. They treat sewage and wastewater to a higher standard than a septic tank and will allow less pollution to occur in the watercourse.

It is recommended that you use an accredited service engineer to advise you on what treatment plant to install and ensure that you are following the general binding rules outlined in the regulations.

You will also need building regulations approval and/or planning permission to install a new sewage treatment plant.

Buying a property with a sewage treatment system

If a property you wish to buy still has a sewage treatment system that is non-compliant, then discuss with the seller whether they intend to replace or upgrade their waste management system before the sale is complete, so that the property follows the General Binding Rules.

You will need to agree with the seller who will be responsible for the replacement or upgrade of the existing treatment system as a condition of sale.

The seller must supply all the necessary information of the sewage treatment system to the buyer (see below). Be sure to ask the seller to supply this if they haven’t already.

If the seller is unwilling to improve or upgrade their system and would prefer you, the buyer, to be responsible instead, then consider lowering your offer to make up for the future costs of improving it yourself.

Selling a property with a sewage treatment system

First, you must ensure you have installed a sewage treatment system that is compliant with the new rules before you sell the property. Being non-compliant will not only detract potential buyers, but you may be subject to enforcement and sanctions by the Environment Agency.

You must also provide the following information to the buyer:

  • 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

Get a permit

If, for any reason, you believe you are unable to follow any of the General Binding Rules, then you will have to apply for a permit. You can get help from the Environment Agency for your application or alternatively, contact them directly to discuss your circumstances. It is recommended you contact the Environment Agency before you start any changes to your discharge system, to ensure you are installing the most appropriate system and correctly following the General Binding Rules.

Talk to your estate agent

An estate agent that specialises in rural properties will be able to advise you further on what to be aware of when buying or selling a property with a sewage management system. We recommend using an NAEA Propertymark Protected agent, who are qualified, trained professionals who are up to date with the latest regulations.



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