Increasing population and changing environment bring the need to renovate existing buildings and build new ones. Infrastructure, especially buried utilities need to be repaired and maintained continuously. The main challenge that workers face when it comes to buried utilities is not knowing their precise location. It is not possible to repair or maintain them without knowing the exact position of the utilities. If the underground utility location is detected incorrectly or has not been detected at all, it can lead to expensive damages and hazardous accidents. To protect assets and people, the quality of mapping and detection has to be ensured.

As per the TSA or The Survey Association in the UK, there are 6 levels of quality when it comes to detecting underground utility services. Each of these levels has been briefly described below.

Level 1

Level 1 refers to a desktop search of the records of utility companies with the results consolidated into base mapping. This is the most basic or general type of survey and it is often provided with a low cost and sometimes for free. However, this level of utility detection only shows the utilities that are known and does not provide their coordinates or location. Moreover, it is impossible to see old utilities, as well as, utilities crossing each other. But, this is a good place to start as it provides information about the size, type and direction of the utilities.

Level 2

Level 2 refers to utility detection using an EML or electromagnetic locator search in both passive and active modes with the located buried utilities marked out on the surface of the ground. EML devices are capable of detecting metal services like, power cables of metal pipes. This level of surveying is perfect for avoidance applications where the services are not going to be mapped. However, it is not possible to detect non-conductive lines by using EML devices like, plastic pipes, concrete pipes or fibre optics.

Level 3

This is like a level 2 survey, but the results are plotted in CAD onto digital base mapping. For level 3 surveying, surveyors mark the utilities that have been detected on the surface of the ground and collect the points with a positioning device. In order to become a level 3 surveyor, the contractor would need a CSCS card by getting a certification in utility mapping and surveying. A CSCS utility surveyor is someone who completes a 5-day utility mapping training programme that covers the processes of PAS128 utility mapping, which includes GPR and EM locators.

Level 4

This is a level 3 survey with the additional processes of inspection pit covers and lifting manholes, recording the contents and making a note of the lines of ducts and pipes. The results are produced digitally in CAD. By opening the covers of a manhole, the surveyor gets information of the dimension, type and materials of the utilities.

Level 5

This is a level 4 survey with the addition of the use of GPR or ground penetrating radar technology. The GPR technology helps in detecting buried utilities. The main benefit of using this technology is detecting non-conducting materials as well. The device can help in locating plastic and concrete pipes or fibre optic cables, along with conductive materials.

Level 6

This is a combined survey of level 1 and level 5, along with 100% coverage of the area that is being surveyed. This survey is the highest level of utility detection and gives the workers a clear idea about the areas where underground utilities are located.

So, these are the levels of utility detection. If you are aspiring to become a utility surveyor, you need to find a training company providing utility mapping and detection courses. Without proper certification, you will only end up jeopardising the entire project.

Once you complete the course, you will know the right use of the detection tools and equipment.