It is a fact of life that many contractors need to dig down into the ground for a variety of different purposes. It may be to install the foundations for a building, it could be to repair a faulty pipeline or service, or it could be for any one of a number of different reasons.

The very big problem that arises here is the fact that there may be a utility service lying underground at exactly the spot that the contractor needs to dig. Even if you are, say, the telephone provider or working on its’ behalf, and you know exactly where the cable lies, how do you know that there is not a gas pipe, water pipe, sewer pipe, electricity cable, or anything else in the spot that you need to dig? The short answer is that you don’t.

Certainly, you will need to contact other utility suppliers in the area, but how do you know whom to contact, and even if you do, whether the information that they provide will be accurate? Not all utility STATS are accurate, and even if they are, they may come in different formats. This can make them extremely difficult to cross-reference, even if you know what you are doing.

To illustrate this, it is a fact that there are about 60,000 utility strikes in the UK every year by contractors carrying out excavation work, or about 230 every working day. If it were that easy, that number would be far less.

Of course, striking and disrupting a utility can have serious consequences. As an absolute minimum, the contract will be delayed, since the utility concerned has to send out workers to make good. This results in the contractor’s workforce standing idle until the damage has been repaired.

Of course, it can be worse than that, because the utility may demand recompense for the damage. There could also be claims for compensation from businesses in the area that have been affected.

And it gets worse – much worse. A cable strike can result in serious injury to workers and on occasion is fatal. There are around a dozen deaths every year in the UK as a result of striking utilities. These, of course, can – and will – result in huge claims for compensation from workers injured whose injuries may only be minor, or could prevent them from ever working again. In the case of a fatality, the claims from family members may be phenomenal.

Striking a gas main may cause a huge explosion, and on occasion is big enough to demolish a building. Striking an electricity cable can also cause explosion and fire, and of course arcing electric current is sufficient to kill.

Perhaps you might think that striking a water main would not be nearly so serious, but water under pressure hitting a worker can cause serious injury, especially when it contains stones from the surrounding soil. It can also cause flooding, leading to drowning, and possibly the collapse of the sides of an excavation which still has workers in it.

None of the foregoing is meant to be a doomsday scenario. The simple facts of the matter are that this happens every day of the week and the results can range from not too bad to almost impossible to visualise.

This is why it is essential for every contractor to undertake a site survey before ever commencing any work. The two tools that are used for underground surveys are the CAT and the Genny. In almost all instances they should be used in combination, as the CAT alone will only detect live power cables.

Anyone who is going to be responsible for undertaking such a survey needs to attend a recognised course on CAT and Genny training in order to fully understand how to use them in all different modes. Several UK companies run a CAT and Genny course, and some of these are recognised by certain bodies such as the CSCS, The Survey Association, and the EUSR.

So, for example, taking a recognised EUSR CAT and Genny course and passing the exam would result in the award of an EUSR card which has advantages for the holder who will then be permitted to work on certain sites such as HS2 where workers who do not have such accreditation would not be allowed.