Assessing pro-environmental behaviour in relation to the management of pollution from private sewage systems

Recent studies suggest that 80 % of the estimated 1.5 million private sewage systems (PSS) in the UK are working inefficiently, potentially threatening drinking water quality and human health, as well as providing a significant source of phosphorus (P) to freshwater bodies, increasing vulnerability to eutrophication. In this report we explore pro-environmental behaviours of PSS users that potentially offer significant reduction in both PSS system failure and P discharge by 1) reducing P input to the PSS by modifying domestic behaviour, and 2) reducing the risk of PSS failure by improving maintenance of the PSS. A detailed questionnaire of 156 PSS users in the catchment of Loch Leven, Scotland, UK, revealed 70 % of users feel responsible for maintaining their PSS, 46 % are potentially maintaining them ineffectively, nearly 30 % have poorly installed systems and 45 % report their PSS had, at some point, blocked or overflowed. Our results indicate that the most effective action to improve PSS operation would be to provide better guidance on low P lifestyles and correct PSS maintenance with an improvement in the provision of facilities to support these pro-environmental behaviours.