Septic tank rules in Scotland

Start with SEPA’s authorisation guidance

SEPA says that, where connection to the public sewer is not possible, an authorisation to discharge is required. The current guide explains the registration and permit routes.

Do not assume registration always fits

SEPA describes a registration route for up to ten domestic properties, with separate criteria for mixed use and sensitive discharge locations. Check the actual circumstances with SEPA; the property count alone does not decide every case.

Check the date of an existing authorisation

The current guide distinguishes registrations before 1 November 2025 from authorisations on or after that date. Check which conditions apply to the actual record. Earlier CAR terminology should not be treated as the whole current process.

Prepare your next enquiry

• Ask whether an existing authorisation can be found in SEPA’s records.
• Have the system type, connected properties, discharge route and location ready.
• Ask how any proposed change affects the authorisation and required design information.
• For maintenance, use the manufacturer’s instructions and conditions on the actual authorisation.
• For waste collection, check the firm’s applicable registration separately from the property’s discharge authorisation.