The Differences Between Air & Hydro Excavation

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When is Air Versus Hydro Excavation Needed on a Worksite?


Vacuum excavation is one of the best methods for digging as it eliminates the danger of striking underground utilities, subsurface features, and anomalies. Traditional heavy machinery like backhoes are invasive and cause damage to underground infrastructure if not operated with care. All too often, Trinity Subsurface receives calls from contractors about broken utility lines in need of emergency repair. Stop damage at the source with vacuum excavation. 



The service, vacuum excavation, can be leveraged for several site needs including:

  • Utility installation with trenching
  • Utility data collection with test holing
  • Exploratory digging with remote excavation


Vac work is conducted at a lower cost with a greater precision than heavy construction machinery. In comparison to hand digging, vacuum excavation is a safer option. Reduce the risk of trenching cave-ins through the process of remote excavation. On-site workers can navigate the construction zone without fear of ground collapse due to this less invasive methodology. In addition, it allows for less congestion and traffic in the excavation area because the equipment can be positioned at a distance.


There are two types of vacuum excavation; hydro and air. 

  • Hydro excavation: The breaking up of soil, utilizing high-pressure water in tandem with a high-speed vacuum.
  • Air excavation: The breaking up of soil, utilizing compressed air in tandem with a high-speed vacuum.


Both systems employ vacuum pumps that remove excavated material. The debris  is deposited into a tank, holding several hundred gallons of dirt or slurry. Each tank features a back door for dumping. The major difference between hydro and vacuum excavation is hydro excavation creates an unusable slurry of debris that cannot be deposited into the hole or trench created. 


Hydro excavation is faster than air excavation and is considered the most efficient type of vacuum excavation. However, this is dependent on the vac truck’s proximity to a dump site. If the scope is significant and the dump site is far away, air excavation may be a better alternative for your project. 


Compressed air excavation is a cleaner alternative to hydro. Accurately identify the depth of a utility, remove material from around plumbing pipelines and sewers, and conduct dry potholing with little mess. This method is great for high density areas of underground utilities. This method reduces risks for any damages or punctures in the pipes. This eliminates the additional time and cost that repairs require.



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