Potholing or Keyholing
Potholing or Keyholing is accomplished by digging a test hole to expose underground utilities to ascertain the horizontal and vertical location of the facility. Some contractors, municipalities and utility companies do not consider potholing to be an option. Rather it’s viewed as an essential phase of underground construction for all types of excavation. Digging potholes with a backhoe is a risky endeavor compared to other methods of potholing due to its potentially destructive nature. The backhoe method is inexact and cumbersome for even skilled backhoe operators that run the risk of hitting and damaging the very utility they were trying to locate and protect.
Air vacuum excavators utilize the kinetic energy in a high velocity air stream to penetrate, expand and break-up soil. The loosened chunks of soil and rock are then removed from the hole through the use of a powerful vacuum. In this way a test hole is created that reveals the buried utility. A typical test hole is 6 inches to 12 inches in diameter and 4 feet to 6 feet deep. However, a test hole one-foot square is also common and holes can be considerably deep if required.
Dry or air excavation has several advantages over water vacuum excavation. For example the air method is faster in most soils and eliminates the need for mud disposal. Since the spoil remains dry, it can immediately be used for backfill. Air methods are safer for the operator and the utilities. One shortcoming of air units is that they are not effective in all soil types, especially wet, heavy clay and large lava rock.
Vacuum excavation is the preferred method for non-destructive exposure of buried utilities. Of the two methods, air vacuum excavation is generally preferred, though specific site and environmental characteristics may lead to a decision to use water vacuum excavation. Hawaii Private Locators LLC utilizes the Pacific-Tek 150g Air Vacuum System with AirSpade Excavation Technology that is considered the leading equipment on the market to date. Contact us for a potholing quote by phone or email.
Honolulu Office: +1-808-260-3558
Call Before You Dig as with all excavations, call for utility locates through the state One Call system and refer to the state of Hawaii prior to potholing and other construction activities.
