Analysis of a large maintenance journal of the sewer networks of three Apulian provinces in southern Italy

Sewage systems play a crucial role in the framework of the water resources cycle. The detection of the causes and typologies of their malfunction is essential not only for guaranteeing correct hydraulic management of the network but also because it can prevent environmental contamination. In this study, a reconnaissance on the typologies and causes of intervention in sewer networks located in three Apulian provinces (Southern Italy) was carried out. The results showed that pipe occlusions with exfiltration are the main cause of intervention, followed by manhole occlusions. Data about pipe material highlighted that stoneware is absolutely the most used material and also the main object of maintenance for obstructions and breakages. Its correlation with the density of inhabitants was also investigated. The absence of detailed information about the age of any single pipe does not permit us to exclude the aging of pipes as a cause of major intervention. However, the frequency of some interventions in the same towns and often on the same trunks of pipes leads to the belief that criticalities occurring in the network could be addressed to incorrect use or bad hydraulic functioning.