Utility Locating

Detecting and marking buried utilities using electromagnetic locators, ground penetrating radar, sondes, and records. The output is normally surface marks in the APWA color code, a field sketch, and — where the work calls for it — coordinates.

Locating is a search, not a lookup. Instruments respond to physics rather than to labels, so a large part of the work is interpretation: deciding whether a response is the target or a neighbouring line, whether a depth reading is trustworthy, and whether the absence of a response means the ground is clear or means the method could not see. Every competent locate therefore states not only what was found but where the data is weak.