From the magazine

Everything you need to know about utility location

A crucial component of Trenchless Technology is the correct identification and location of existing utilities, leaks, voids and anomalies before any work is carried out. For professionals working in and around critical infrastructure, a solid understanding of “÷what lies beneath’ is a vital aspect of their daily life.

Underground utilities can often deviate from existing plans, and increasing concerns over safety and third-party damages have led to a variety of techniques being available for the detection of underground utilities.

The main techniques employed for condition investigation and assessment and structural investigation include ground penetrating radar (GPR), electromagnetic frequency (EMF) devices, sonar and potholing. The Ultimate Guide to Utility Location outlines, in detail, the differences between each approach and what techniques should be considered complimentary to one another.

Below is an extract from The Ultimate Guide to Utility Location, which is available as a FREE download in the Trenchless Australasia Online Shop – head to to download your free copy today.

Equipment options: type, application, flexibility

Utility locating has come a long way
in a relatively short time. There have been some major changes over the past 30 years where utility locating has moved from being an “÷art form’ to a true science; a science than anyone can master with relative ease.

The industry has progressed from the dowsing rod, known unofficially as the “÷bent twig’ approach, an approach that is deemed little more than superstition today, to a wide array of scientific and proven locating methods. Improved technology has made it easier to locate underground infrastructure, with more intuitive displays and more functions to complete locating tasks efficiently. Professionals are offered a range of products that utilise current generation digital signal processing (DSP) locating instruments. Most manufacturers have now graduated to modern technology and are using DSP, a computer-based background for their electromagnetic location.

However, all this technology is worthless, and sometimes dangerous, unless an operator understands the theory and technology behind their instruments.

Purchasing considerations

When considering an appropriate locating device, there are a lot of factors to weigh-up when making your decision. Will you be doing locating work as your main business or will you
be doing locating as a part of your overall work situation? This is the first question to answer, as this will determine what level of locating you will need to address.

The second consideration should be: what do I want to achieve with the equipment? Answering this question will help decide the next level of options; what is the simplest and most cost-effective option for my needs? Do I want ease of use so that all employees can use it, or do I want a more complicated machine with additional features?

Once you have determined your requirements, you can proceed to look at the options open to you and then make an informed decision on which is best for you, be it a GPR which can potentially cover all materials, an EMF style locator for any conductive materials, or you may choose a sonar system, which uses the injection of sounds or ultra-sonic waves for locating plastic pipes. Once you have located your service, you also need to know its depth and to confirm its exact location – this is where potholing can be used to complete your task.

In most cases, the products mentioned can easily be used by a sole operator and each piece of equipment has its own specific benefits. It is also worth considering the limitations of each piece of equipment and if your company would be better off utilising a “÷bundled’ approach, using two or more pieces of equipment to minimise error in locating.

Again, your choice comes back to what your ultimate job description is. Naturally, the level of training needed and the cost of the equipment varies according to the level of sophistication that you require.

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