Everybody in the UK uses utilities such as water, telephones, broadband, gas, sewage pipes, and more. OK, not everybody uses gas, and some people don’t have broadband, but most of us use most of them and the one thing they all have in common is that almost all of these run underground where they cannot be seen – out of sight, out of mind. And that is fine. Just so long as they keep running and provide all the services that we need there isn’t a problem. It is when they stop providing the services that we need that there is suddenly an almighty problem.

A similar example is coronavirus, or Covid-19 as our medical friends now choose to call it. We don’t know how far this is going to spread, but in China and Italy it has led to a major clamp down. As of March 10th, in Italy only three people are allowed into a food store at any one time. Everybody in the queue has to stand at least one metre away from the next person. Right. So you need to go to Tesco, the greengrocer, the fish shop, the paper shop, the hairdresser – the list goes on. If things suddenly become as they are in Italy, it will take you all day. You might be able to do without the paper shop and the hairdresser, but the others are where you get your food from. And in the case of Tesco, your toilet rolls – if there are any left.

All the while everything runs as normal there is no problem. But when that supply is cut off or reduced to a trickle, there are huge problems. If your water supply is cut off, or your electricity, what are you going to do? You can’t wash, shower, bath, make a cup of tea, watch TV, and you will be sitting in the dark!

Obviously, we don’t know where coronavirus is going to take us, but the comparison with our utilities makes sense. If a contractor digs a hole in the street and cuts off our electricity, there is nothing that we can do until the supplier manages to connect it again. If that contractor also happens to hit a gas main at the same time, there will very likely be explosion and fire. Workers can get seriously injured and even killed (there are approximately a dozen fatalities every year as a result of workers causing a cable strike).

You might think that striking a water pipe wouldn’t cause too much damage, but it can cause flooding. Water under pressure can also hurl stones and other debris out of the ground and that can cause injury if it hits a worker or passer-by. Striking telephone and broadband cables can put all the local businesses affected out of business – literally – until the connection can be restored.

This is why undertaking a thorough survey of any site where an excavation is needed is absolutely essential before any work whatsoever is undertaken. Fortunately, today we have some really clever tools which can help to locate and identify underground services, but they are not infallible. They are designed to locate and track the path of underground services in the area which is to be excavated so that the surface of the ground can be marked accordingly and, therefore, the utilities avoided.

Unfortunately, this doesn’t work as well as it might, or as it should do. There are approximately 60,000 strikes of underground utilities in the UK every year. That doesn’t mean that there is anything wrong with the equipment that is used, but rather that the surveyor using it has insufficient training and is unaware of all its’ limitations.

This is why anyone who is tasked with locating and identifying underground services must go on an underground surveyor course in order to understand all the tricks of the trade. Not only will such a course teach a surveyor, or potential surveyor, how to use the tools such as the CAT and Genny, but it should also teach him or her the fact that these tools do have limitations, and more to the point, exactly what those limitations are.

Only when you understand all that can you undertake a survey with complete confidence.