Understanding problems associated with small-scale Private Sewage Systems (PSS) from regulators' perspectives

https://www.crew.ac.uk/publication/private_sewage_systems

Private sewage systems (PSS) refer to systems that are not connected to the mains sewer. According to estimates by the Scottish Environment Protection Agency (SEPA) the majority of PSS in Scotland serve domestic properties. This work focuses on PSS serving up to nine properties, i.e., up to 50 population equivalent.

Modelled evidence (as of 2017) on PSS locations and property addresses was reviewed and total PSS numbers, PSS density per hectare and distance of modelled PSS locations from coastline and watercourses was estimated. SEPA is aware that problems in PSS design, siting, management, and maintenance may lead to problems such as nuisance and diffuse pollution. Qualitative evidence on PSS problems, regulatory weaknesses, and barriers to improvements from regulators’ perspectives was collected through three workshops. Attendees from SEPA and local authorities shared their experiences and perspectives, which are summarised in this report. A detailed account of the different types of PSS-related problems from the perspective of the householder, neighbours, local communities, and regulatory authorities, i.e., SEPA and the local authorities, will help to inform bespoke actions.