Water & Wastewater Treatment

www.wwtonline.co.uk | WWT | NOVEMBER 2015 | 43 In the know Technically speaking: pipes and pipelines Finding the weak link Condition assessments are vital for safeguarding pipeline assets, and there are a number of new technologies that can help stops, or the sewage backs up, there's a problem. Beyond that, though, much of the time utilities aren't even 100% sure where they are, let alone what condition they are in. Fire-fighting is no way to manage valuable assets. Would you allow your car, or your phone, or even a ball- point pen to completely fall to pieces before you did something about it? If not, why would you allow a £10M water main to fail before you took some action? The answer, usually, is because nobody knew the asset was going to fail. Nobody knew it would fail because nobody could see what condition it was in. Pipeline asset condition is a product of many factors, a complex mix of ground conditions, manufacture, installation, previous replacement, weight loadings and so on, which although extensively modelled, the industry doesn't fully understand as each below ground environment is subtly unique. Hence the need for physical condition inspection. The key to sustainable asset management is having the right information. In this article we will look at some of the inspection technologies that are currently available, when they should be used, and how they can help water utilities to manage their pipelines and sewers. Right tool for the job As an asset manager, you want to deploy your resources as efficiently as possible. Therefore the first question to ask is what sort of survey needs to be accomplished. Do you know there is a problem? Do you suspect there is a problem? Asset inspection is all about investing the right budget in the right place at the right time. Before considering inspection techniques, understanding the risks associated with the asset sets the priority of the pipeline for inspection. Then there is a need to select the most appropriate technique, as no one solution fits all needs. Techniques can be selected using a decision matrix based on resolution, reliability and cost. Resolution is the level of condition detail the technique is capable of identifying, and it increases with increasing technology capability. Reliability is the level of certainty in identifying the condition. Generally, uncertainty decreases with increasing technology capability. Cost, in £ per metre or km, increases with technology capability. Other considerations are the pipe material and the purpose of the inspection. There is a solution for every diameter and material of pipe, and different equipment for leak detection and condition assessment. The water industry in the UK has for several decades looked enviously over the fence at the oil and gas industry and the techniques they have developed for inspection of critical pipeline assets in extremely challenging environments. Although Simple inspection technique selection matrix – based on resolution, coverage and cost. I t might be stating the obvious, but one of the biggest problems of managing water and wastewater pipes is that they are almost always underground. So they don't draw attention to themselves, and there tends to be a lot of soil in the way to stop you from seeing them. We do know some things about them. For instance, we can usually tell whether they are doing their job – if the water Leo CaRsweLL HEad Of TECHNOlOgy WRC ZaChaRy aLexandeR CONSulTaNT WRC

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