Article / 5 Mar 2021

General binding rules for small domestic sewage discharges

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Gateley Legal

Making a discharge to groundwater or surface waters usually requires an environmental permit. However, there is an exemption for small sewage discharges from domestic septic tanks and small domestic package sewage treatment plants under the Environmental Permitting regime.

Exempt small sewage discharges previously had to be registered however, the registration scheme has been replaced by the general binding rules. This article covers the rules in England, but not Wales where the rules differ slightly. 

The rules governing small domestic sewage discharges

In England, the requirements to qualify for an exemption were simplified on 1 January 2015 when the requirement to register an exempt discharge was dispensed with. The general binding rules now set out the conditions that must be met in order for a discharge to qualify for the exemption from the requirement to have an environmental permit. The general binding rules repeat and expand on the Environmental Permitting Regulations 2016 (the “EP Regulations 2016”), which came into force on 1 January 2017, which regulate discharges to groundwater and surface waters. 

The exemption

  1. The discharge must not cause pollution of groundwater or surface water.
  2. For surface water, the discharge must not exceed five cubic metres per day. For groundwater, the discharge must not exceed two cubic metres per day. 
  3. The discharge could not reasonably be made to the public sewer. 
  4. The rules must be met in respect of source protection zones and sensitive areas, the details of which are set out in the EP Regulations 2016.
  5. The discharge must not be from a septic tank into surface waters. The exemption only applies to discharges from septic tanks into groundwater or from sewage treatment plants into surface waters or groundwater. 
  6. The equipment from which the small domestic sewage discharge is made must comply with the relevant requirements and standards on design, construction, siting, installation and capacity, must be maintained in accordance with the manufacturer’s specification and by a competent person, and must be decommissioned when the facility stops operating. The waste sludge must be safely disposed of by a registered waste carrier and properly managed at a permitted waste facility. 
  7. For new discharges (those that started on or after 1 January 2015), all necessary planning and building control approvals must be in place: there are ‘minimum distance from sensitive area’ requirements that must be met; there are limitations on the type of surface water that can be discharged into; and they must not be within 30 metres of a public sewer. 
  8. The discharge must not contain any trade effluent. 

Septic tanks outside of the exemption

As mentioned above, septic tanks that discharge to surface waters are not exempt. The Environment Agency guidance indicates that these must be replaced or upgraded as soon as possible, meaning plans to carry out the replacement or upgrade must be in place within a reasonable timescale (typically 12 months). 

Although such discharges are no longer exempt, a discharge from a septic tank to surface waters may already hold an existing valid environmental permit from before the change in regulation. Where this is the case, the discharge can continue within the conditions of that permit unless and until the permit is reviewed and then either revoked or varied. 

Things to consider with residential property

If you are selling a property that has a small domestic sewage discharge on the land, you must provide written information to the buyer stating this, describing the sewage treatment plant or septic tank and setting out maintenance requirements. If you are buying such a property, you should be aware that you should expect such information to be provided.

If a property has a septic tank that discharges directly to surface water, as mentioned above, replacement or upgrade will be required within a reasonable timescale. Responsibility for this should be discussed between the buyer and seller as a condition of sale. 

Other things that should be considered if you are thinking about buying a property with a small domestic sewage discharge on the land include:

  • Whether it qualifies for the exemption;
  • Whether it complies with planning legislation or building regulations;
  • Where the drainage field for it is on adjoining land, whether there is an easement;
  • Where it is on adjoining land and managed jointly with another landowner or by a third party, whether there is a written maintenance agreement;
  • Where it is located on someone else’s property, whether there are appropriate rights to access it and obligations in respect of repair and maintenance; and  
  • Whether it is defective (a defective small domestic sewage discharge could cause contamination problems that require remediation).

Do you own a property that has a small domestic sewage discharge?

If you own a property that has a small domestic sewage discharge on the land or are considering buying such a property, please contact an expert listed below or find out more about our residential property & conveyancing services here.