Pothole Test Hole

The term "pothole test hole" or simply "test hole" is used interchangeably with "pothole" in the hydrovac and subsurface utility engineering industries. Both terms describe the same process: creating a small, controlled excavation directly over a suspected utility line to physically expose it for visual verification and measurement.

Test holes are typically 12 to 24 inches in diameter at the surface, though the exact size depends on the depth of the utility and the soil conditions. The excavation is carried to a depth sufficient to fully expose the top and sides of the utility, allowing measurement of its depth below grade, horizontal position, diameter, material type, and general condition. This information is documented with photographs, field notes, and GPS coordinates.

The term "test hole" is more commonly used in engineering specifications, SUE reports, and project documents, while "pothole" is the more common term in everyday field use. Regardless of terminology, the purpose is identical: to provide Quality Level A utility data through physical verification. Hydrovac is the preferred method for creating test holes because it eliminates the risk of utility damage that exists with mechanical excavation or hand digging.