Potholing is the practice of safely digging a test hole to expose underground utilities to ascertain the horizontal and vertical location of utilities.

Purpose

The purpose of this practice is to locate underground utilities with enough precision for detailed design or to allow the safe use of powered equipment adjacent to these utilities.

Potholing may be used for planning the excavation and during the course of the excavation provided the frequency of the potholing is adequate to detect and confirm the direction of the utility line(s).

Potholing must be used to expose utilities for any excavation/drilling within the three-foot tolerance zone of marked utilities and whenever the location of utilities has a high degree of variance or uncertainty, such as plastic natural gas lines.

If known utilities are not located, potholing of the entire excavation is required until the utility is found.