Operation and maintenance of the public sewer system represent key tasks for an operator. Condition assessment is usually conducted by conventional closed circuit television (CCTV) inspection. However, alternative tools such as manhole-zoom cameras (MZCs) and the acoustic technology SewerBatt® are available today. The INNOKANIS project investigates structural and operational condition assessment in the sewer system by means of 3 MZC models and SewerBatt® to develop a combined optical and acoustic device as cost-effective alternative to conventional CCTV inspection. The first field trials of the ongoing project were conducted in Austria in 2011. 640 conditions according to EN 13508-2/A1 were investigated and compared against conventional CCTV reports. Individual and combined detection rates for both devices were calculated. Based on the current findings, both MZC and SewerBatt® are effective alternatives to conventional CCTV inspection. In addition, performance is significantly enhanced when both devices are used in combination.

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This paper reports on the development of a low-cost, rapidly deployable sensor for surveying live sewers for blockages and structural failures. The anticipated cost is an order of magnitude lower than current techniques. The technology is based on acoustic normal model decomposition, The instrument emits short coded acoustic signals which are reflected from any sewer wall defect. The acoustic signals can be short Gaussian pulses or longer sinusoidal sweeps and pseudo-random noise. The processing algorithms used on the reflected signal can predict the extent and geometry of the pipe deformation, and the locations and approximate size of common blockages. The effect of the water level on the frequency of the fundamental mode has also been investigated. It is shown that the technique can be adapted to work reliably in relatively large 600 mm diameter sewer pipes.

Article:Bin Ali, M.T., Horoshenkov, K.V. orcid.org/0000-0002-6188-0369 and Tait, S.J. (2011) Rapid detection of sewer defects and blockages using acoustic-based instrumentation. Water Science and Technology, 64 (8). pp. 1700 -1707 . ISSN 0273-1223 https://doi.org/10. 2166/wst.2011.183 eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. RÉSUMÉEn Grande-Bretagne, les inondations par débordement de réseaux sont de plus en plus fréquemment associées aux problèmes de colmatage. Il est difficile de traiter les colmatages car, bien qu'il y ait des endroits où ils sont plus susceptibles de se produire, ces incidents interviennent par intermittence. Pour assurer une gestion proactive des colmatages de réseaux, les responsables doivent pouvoir localiser rapidement les sites de colmatage. Les technologies traditionnelles d'inspection par caméras sont lentes et relativement onéreuses et donc inadaptées à l'inspection nécessairement rapide d'un réseau, pour la gestion proactive des colmatages. Ce document traite du développement d'une sonde acoustique. Ce dispositif a été testé en laboratoire sur une conduite en taille réelle, et a démontré qu'il était en mesure de faire la distinction entre des colmatages et des éléments structurels d'une conduite tels qu'un regard de visite ou un raccordement latéral. L'analyse du signal acoustique permet de localiser le colmatage et fournit des informations sur ses caractéristiques. La mesure est très rapide et objective et permet d'effectuer des inspections plus rapidement qu'au moyen des technologies existantes de systèmes caméra. ABSTRACTSewer flooding incidents in the UK are being increasingly associated with the presence of blockages. Blockages are difficult to deal with as although there are locations where they are more likely to occur, they do occur intermittently. In order to manage sewer blockage pro-actively sewer manager need to be able to identify the location of blockages promptly. Traditional CCTV inspection technologies are slow and relatively expensive so are not well suited to the rapid inspection of a network. This is needed if managers are to be able to address sewer blockages pro-actively. This paper reports on the development of an acoustic b...

Combined sewer overflow structures (CSO) play an important role in sewer networks. When the local capacity of a sewer system is exceeded during intense rainfall events, they act as a “safety valve” and discharge excess rainfall run-off and wastewater directly to a natural receiving water body, thus preventing widespread urban flooding. There is a regulatory requirement that solids in CSO spills must be small and their amount strictly controlled. Therefore, a vast majority of CSOs in the UK contain screens. This paper presents the results of a feasibility study of using low-cost, low-energy acoustic sensors to remotely assess the condition of CSO screens to move to cost-effective reactive maintenance visits. In situ trials were carried out in several CSOs to evaluate the performance of the acoustic sensor under realistic screen and flow conditions. The results demonstrate that the system is robust within ±2.5% to work successfully in a live CSO environment. The observed changes in the screen condition resulted in 8–39% changes in the values of the coefficient in the proposed acoustic model. These changes are detectable and consistent with observed screen and hydraulic data. This study suggested that acoustic-based sensing can effectively monitor the CSO screen blockage conditions and hence reduce the risk of non-compliant CSO spills.