Webinar: Techniques for monitoring underground infrastructure
Current developments for sewers
Summary by Thomas Brüggemann, IKT
University of Sheffield, IKT – Institute for Underground Infrastructure and Deltares organized a webinar on 30th of January 2025 about monitoring techniques for sewer networks. The presentation ranged from new approaches that are entering the market to techniques and results that are emerging from recent completed research.
The more than 50 participants from water companies, industry, Municipalities, local authorities and science were welcomed by the moderators Alma Schellart from The University of Sheffield and Iain Naismith from IKT with an introductory presentation on Co-UDlabs, upcoming events and the new Urban Drainage Working Group UDRAIN.
After that Joshua Myrans from Southwest Water, a British water company, presented a project on the use of AI to improve the quality and efficiency of sewer surveying. South West Water, responsible for a sewer network of more than 22,000 km, collaborates within this research project with industry and science to ensure user relevance. The use of AI, is a promising approach for South West Water to improve sewer operation and maintaining processes.
Manuel Regueiro-Picallo from University of Coruña presented the idea of the use of temperature to estimate depths in sewer pipes and gully pots, addressed in the research topic MONTSE: MONitoring Temperatures in Sediments, as a part of Co-UDlabs. An essential conclusion: the temperature-based systems can be low-cost and easy scale and implement in urban drainage systems, leading to optimal inspection and cleaning strategies.
Leak tests are often required for wastewater connection pipes of property drainage systems in Germany, especially for new constructions and rehabilitated pipes. But what about the quality of these test procedures carried out by specialist contractors? In an IKT research project, presented by Martin Liebscher, the quality of more than 1,000 leak tests carried out at lab and in-situ by various contractors using leak testing methods with air, water and visual inspection was evaluated and compared. The low error rate leads to the conclusion that testing with air and water is a relatively reliable test method.
How to inspect Rising Mains (Wastewater pressure pipes)? Ton Beenen from Stichting Rioned and Irene Scheperboer reported on the research project AIR – Assessment of Inspection technology for Rising Mains. Within Co-UDlabs the Dutch foundation Stichting Rioned got access to IKT´s large test facility to compare the performance of inspection methods. The observations at lab clearly show, that techniques with ultrasonic sensors perform very well in locating and quantifying damage in steel and pvc pipes. Technique based on hydrophone was too much disturbed by entrained air to get good results. Johann Post from Parnters4UrbanWater presented first observations of ongoing tests of these inspection techniques in situ at the city of Arnhem. Conditions in the field can be more challenging than at lab. More results will follow when this in situ project is completed.
Mark Klameth from IKT introduced the MAC-System (Mechanical Assessment of Conduits), a non-destructive testing method for determination of both the condition and structural integrity of accessible sewers. This system was developed by Eau de Paris in 1989 and improved in a cooperation project between IKT and Eau de Paris. IKT is currently developing a semi-automatic system for non-accessible sewers.
The last presentation was about “Acoustic assessment of in-pipe defects in unpressurized pipes”. Kiril Horoshenkov from University of Sheffield reported on this topic taking into account the key research challenges for acoustic inspection, e.g. wall roughness, multi-modal propagation, wave desertion, variable water level. The topic of acoustic assessment is part of the UK Pipebots project developing different kind of inspection robots for sewers.
The subsequent discussion was mainly characterized by detailed questions from the participants to the speakers about the content of the presentations. In general, however, it is clear that there is still a lot of room for development, particularly with regard to the major challenge of ageing infrastructure.