The real issues with in-ground SUDS in Scotland

The aim of this research was to produce enhanced detailing and improved operation of in-ground SUDS. Data from on-site monitoring at three filter drain and three infiltration trench systems were analysed and the results were combined with information gathered from 40 assessments of in-situ systems in Eastern Scotland. Current findings showed that almost 50% of all systems were found to be unsatisfactory and more than half of these were rated as having failed. 36% provided fair and 16%, good performance. Only one system was considered to be performing excellently. Several reasons were identified for the poor performance. The principal cause of problems was runoff from unstabilised areas or construction runoff, which was found to be affecting the systems’ longevity. Almost 30% of all sites were affected by construction runoff. Another major problem was related to system maintenance since maintenance programs were generally not in place. This study has shown that regular maintenance is vital for the longevity of in-ground SUDS.