Geovision provide utility surveys compliant to PAS 128 specifications

What are the different survey types?

When specifying a PAS 128 compliant underground utility survey, there are different levels of detail that may be required. The selection criteria ensure the data collected meets the on-site requirements of the specific project.

The PAS 128 survey types are:

•  Type D: Underground utilities are plotted based only on record data, otherwise known as desktop survey.
• Type C: Underground utilities are plotted based only on utility record data, but with on-site investigation to match physical indicators above ground with the records as a best fit.
• Type B: Utilities are detected by geophysical methods, such as Ground Penetrative Radar (GPR) to get an exact horizontal position and vertical position i.e. depth. Category B Surveys are carried out to one of four levels of accuracy with each requiring a different survey type.
• Type A: Utilities are verified and positioned by eye, using physical identification, which may include visual inspection, vacuum excavation, or hand dug trial pitting.