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Service level statement for small-scale private sewage systems (Sep 2023)

This statement describes the level of service you can expect from SEPA in response to complaints about small scale private sewage systems.

By “small scale” we mean discharges arising from private sewage systems (i.e., not connected to a Scottish Water sewer) which serve individual properties or from shared private systems serving a small number of properties. These are typically registration-level activities and considered by SEPA as low environmental risk.


Every year SEPA receives hundreds of enquiries and complaints about small scale private sewage systems. Most complaints relate to the ‘ponding’ of sewage on the surface of the ground, or the presence of sewage related solids in rivers or coastal foreshores. Many of the problems associated with private sewage are because systems are poorly maintained and repaired. Commonly complaints about private sewage are to do with disputes between neighbours.

The amount of time SEPA spends dealing with enquiries and investigating complaints outweighs the very low risk of harm they present to the water environment and negatively affects our ability to focus work on the most significant environmental harms.


Owners and operators of septic tanks or small private sewage treatment systems are wholly responsible for ensuring that their treatment systems are maintained in good working order and do not cause pollution or nuisance to their neighbours, and every effort should be taken to make sure they do not cause problems.

SEPA will limit its response to complaints about private sewage to only providing standard advice and guidance how systems should be operated, maintained, and repaired. SEPA will maintain a deterrent by carrying out compliance campaigns to focus its regulatory effort to known problem locations or subject areas (e.g., unauthorised discharges, authorisations with upgrade conditions). These campaigns will be able to use enforcement tools, such as Fixed Monetary Penalties, to change behaviours for those who persistently fail to comply, and where improvements are necessary to limit localised environmental harm or nuisance.

Service level

What we will do

  • Provide standard advice and guidance how to resolve problems
  • Remind householders of their legal responsibilities and risks of not fixing problems
  • Use intelligence gathered about complaints to inform future compliance campaigns

What we will not do

  • Get involved in any discussions about rights of access, wayleave, or deeds of servitude, as these are civil matters
  • Respond to complaints about ponding of sewage on land, where no sewage is entering surface waters
  • Respond to repeat complaints about the same problem

Advice and guidance

Further guidance and advice on maintenance of septic tanks is available in SEPA's Septic Tank Guide. British Water provide guidance on Wastewater Treatment Plants.

For information on accessing this document in an alternative format or language, please contact SEPA by emailing

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