Air vacuum excavation is the process of excavating a test hole using compressed air to loosen the dirt and soil and a vacuum system to suck up the material into a tank. The process is the safest method of excavating to expose existing utilities. CPF has performed over a thousand test pit excavations since 1990 without any damage to existing utilities.
The equipment includes power source, sign boards, air and vacuum systems, soils tanks, air driven demolition and drill tools and control systems. All components are truck mounted.
The advantages of vacuum excavation (test pitting) to expose a utility are:
1) No damage to the utility.
2) No mechanical moving parts touch the utility.
3) Can be used on all utilities (gas, water, thermal distributions systems, power and communications including fiber optics).
4) Small hole: 12" x 12" typical.
5) Less disruption to and cleaner work sites.
6) No unnecessary traffic congestion.
7) Easy Patch - both permanent and temporary.
8) Cost effective.
The application of vacuum test pitting for utility verification can be extremely useful at the design or planning stage of a project in that critical information can be obtained that can be used in the design and planning. Some advantages are:
1) Reduces the surprises and associated costs and delays at the construction stage when latent subsurface conditions are encountered.
2) Utilities in conflict with the proposed new installation can be moved and placed in service before construction begins. Inversely the proposed design can be changed to suit field verified conditions.
If the determination of the depth of a utility by vacuum test pitting is not done at the design stage, than using the service at the construction stage can prevent costly damage to the existing utilities. Some of the advantages for using vacuum test pitting at the construction stage are:
1) A safe method of exposing the utility.
2) No damage to the utility.
3) Utility can be exposed prior to excavation by trencher or backhoe.
4) The utilities can be verified in site and profile prior to blind boring operations.