As the underground distribution network becomes increasingly complex the potential for fatalities, cost to repair damaged utilities and possible fines to recover loss of service can be a potential hazard with drilling and excavating services. Vacuum excavation utilizes a high pressure air stream to penetrate, expand and break-up soil. Loose soil and rocks are simultaneously removed by a vacuum. This technique is typically used to create a hole as deep as required to expose the buried utility. When utilized properly, the method is a safe, non destructive means of excavation.
In general, vacuum excavations either expose a utility or remove earth in close proximity to a utility. An example of exposing the utility would be day lighting or potholing a gas main to determine its exact vertical and horizontal position, also known as Quality Level A in the field of Subsurface Utility Engineering. An example of the second general use would be an excavation in preparation for a boring or monitoring well.
When excavating in the proximity of buried utilities, vacuum excavation is a safe alternative to hydraulic methods and an efficient alternative to hand digging.