Why We Don't Give Depth on a Utility Locate

Every quote we send says the same thing: we mark the horizontal position of the line on the surface, and we do not give depth. People ask why, and the honest answer is that the number would be a guess dressed up as a measurement.

What the locator actually does. An electromagnetic locator estimates depth from the strength and shape of the signal it picks up, and that reading moves with soil moisture, soil type, nearby lines carrying their own signal, how strong the signal on the target pipe is, and how the instrument is held. On a good day the estimate is close. On a wet day, next to a second line, on a pipe with a weak signal, it can be off by a foot or more, and the crew reading the paint has no way to know which day it was. Ground-penetrating radar is no better here: its depth depends on a soil velocity that is assumed, not measured.

Why a wrong number is worse than none. A crew that has no depth digs carefully. A crew that has a number digs confidently to it. When the number is wrong, the bucket finds the line at eighteen inches while everybody was expecting thirty, and the paint on the ground gets blamed for something paint was never able to say.

What to do instead. Treat every mark as a no-dig line. Hand-dig or pothole to expose the line before you cross it with a machine, and keep mechanical excavation clear of the paint until you can see the pipe. The mark on the ground governs over any sketch, photo or map we hand you. If a project needs depth for design, vacuum excavation exposes the line without damaging it; we do not pothole, but once a test hole is open and the line is visible, we will verify what it is and record the depth you can measure with a tape.

If you want to talk through a site before the machine arrives, send the address through the request form, or call or text (719) 800-4937.