Utilities discovered through potholing are located about the surface area by putting two reference points (usually 36" aside) on both side of your pothole together the centerline (or edge) on the utility, applying paving nails or sixty penny nails as acceptable. Depth measurements (to the nearest ½ inch) are taken https://www.evernote.com/shard/s706/sh/9dc9ef1d-6117-a495-3328-bd5037fcdaf0/29dbff6460b1477c915b5d89e2fc3671