LINE LOCATING is hydro excavating to locate known or unknown subsurface utilities. Similar to pot holing, line locating is most often used when the exact position of the utility is unknown. The process starts with a pot hole, ranging from 8 to 12 inches in diameter. With the mechanical or manual vacuum system hovering the designated area, the operator excavates down to a reasonable depth (usually determined by specifications on existing As-builts).
If the utility is not located at the anticipated depth, an experienced operator will generally excavate an additional vertical foot then begin cutting a narrow slot trench horizontal to the utility. This is done in 1 to 2 foot increments on either side of the pot hole until the existing utility is located.
If after using these techniques the utility is still not located, careful consideration should be given to referenced As-Builts and above-ground markings. It is not uncommon for these useful preliminary guides to be inaccurate and grossly off the mark. The utility may be located more than a dozen feet away from the previously evidenced or “designated” area.
One advantage that clients get with Hydro Spy LLC is a clear plan of action for the necessary discovery of specific utilities. Our experience allows us to apply a hybrid of techniques to locate underground utilities.