PAS 128 Survey Type B (Detection)

What is a PAS128 Survey Type B (Detection)?

As defined in PAS128 it is “The remote detection of underground utilities uses geophysical techniques. As the survey area is scanned, signals are received and analysed for anomalous responses. If the positions of these anomalies form linear strings they can be interpreted as features, such as utilities.”

This means that, unlike Survey Types D & C, Survey Type B can identify the location of utilities both horizontally and vertically within clearly defined accuracies based on methods of the location used.

Why would I consider requesting a PAS128 Survey Type B?

Some of the main reasons for undertaking Survey Type B are:

• Survey Type D (Desktop) has been carried out and there is a high density of utilities within the site area.
• Survey Type C (Site Reconnaissance) has been carried out and has identified clear discrepancies between owner-provided utility information and onsite surface feature locations within the site area or unable to locate surface features.
• Ground excavation work is required, so a more accurate location of utilities is needed in compliance with HSG47 (Avoiding Danger from Underground Services).