Non-Destructive Excavation

Non-destructive excavation is a broad term that encompasses all excavation techniques designed to safely expose buried utilities without risk of mechanical damage. The three primary NDE methods are hydro excavation (using pressurized water), air excavation (using compressed air), and hand digging with non-conductive hand tools. Of these, hydro excavation is the most common and efficient.

NDE is required by regulation in most jurisdictions when excavating within the tolerance zone of a marked utility. The tolerance zone varies by state but is typically 18 to 24 inches from the outer edge of the utility on each side. NDE is also required by many utility owners, pipeline operators, and project specifications regardless of tolerance zone regulations.

The adoption of NDE has dramatically reduced the number of utility strikes nationwide. According to the Common Ground Alliance, excavation damage to underground utilities costs billions of dollars annually in the United States. NDE methods, particularly hydrovac excavation, have proven to be the most effective way to eliminate this damage while maintaining productive excavation rates.