Potholing also known as (Vacuum Excavation, Utility Potholing, Vacuum Potholing, Hydro-Vac Services and Potholing Services) is the practice of digging a test hole to expose underground utilities to ascertain the horizontal and vertical location of the facility.
The horizontal and vertical position of the exposed facility must be tied to a survey benchmark or permanent above grade feature. The position may be identified by GPS or traditional survey coordinates or by measuring the distance, with a tape measure, to permanent features in three horizontal directions. In addition, the vertical distance below grade should be obtained.
Nearly all municipalities and utility companies consider potholing mandatory.
The four stages of utility potholing are:
1. Utility Location and Surface Opening
2. Exposing (Daylighting Utilities)
3. Soil Extraction (Water+Air Vacuum)
4. Utility Depth Measurement & Mapping