Potholing or daylighting is the practice of digging a test hole to expose underground utilities to determine their horizontal and vertical location. Traditionally, this was done either with a backhoe, which is a cumbersome and high risk practice, or hand digging, which is labor intensive and time consuming. Hydro excavation is now the preferred method for potholing or daylighting.
Hydro excavation enables underground utilities to be exposed without the risks inherent in traditional manual or mechanical excavation methods because hydro excavation is a non-mechanical, non-destructive process. Potholing is also a time and cost saving digging method for the installation of signs, telephone poles, and fences.
For potholing or daylighting, McRae's Environmental Services hydro excavator, uses a unique combination of water pressure and vacuum, combined in one self-contained mobile unit. Water is pressurized and injected into the ground through a handheld wand to safely wash soil from the underground area. The resulting slurry is vacuumed from the excavation through a large debris hose connected to a debris tank.
Since it is a non-destructive process, hydro excavation eliminates the risk of damage to buried cables and pipes. Using hydro excavation enables the location, type, and depth of the utility to be accurately established.
Not only is hydro excavation faster and more accurate, but it also does less damage leaving minimal environmental footprint to the surrounding soil than mechanical excavation and thus minimizes site restoration time and expense.