Vacuum Excavation

Outfitted with a compressed air lance, waste storage chamber, vacuum suction, and twin or triple air vehicle fans, Vacuum trucks have a unique set of tools onboard.

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There are many methods of excavating land, but few are as non-destructive as vacuum excavation. Done through vacuum trucks or “hydrovac” trucks, hydro excavation is a popular choice for sensitive digging operations. What is vacuum excavation used for, and what even is a vacuum truck? We have the answers to those questions and more below.


You’ll likely have seen a vacuum truck before driving around the city as they commonly deal with cleaning clogged drains. However, they do so much more than that.

Five Reasons for Vacuum Excavation

  1. It offers an eco-friendly, precise, and clean method of moving soil. Hydrovac units allow for a non-destructive and accurate process to excavate soil and locate underground utilities. Because there is neither mechanical extraction involved nor trenches lined with contaminated soil, there is little to no chance of runoff to sewers and waterway systems. It also reduces excavation site mess and congestion.
  2. It gets the job completed much faster. Compared to the old-fashioned and laborious way of soil removal, using the hydrovac process requires less effort. In addition, it complements the digging process ten times quicker than a shovel.
  3. It’s safer than traditional machinery. Hydrovac excavations are non-mechanic, making them effective in reducing construction mishaps brought about by machinery. Did you know that, according to the Occupational Safety and Health Administration, the number of trench-related hazards and fatalities due to cave-ins and collapses in 2016 “nearly doubled the average of the previous five years”? Hydrovac units are deemed a viable solution to the dangers of a construction project.
  4. It serves a variety of applications in many sectors. For example, a hydrovac machine is used in directional drilling, slot trenching, utility locating, coring, and potholing. They are as valuable for utility or plumbing and electrical installations as in construction. Today, telecommunication and oil or gas plant industries use hydrovac units for subsurface engineering.
  5. Because it is proven faster, more efficient, and more productive than conventional equipment with minimal risk of subsurface damage or work hazard, hydrovac excavations make for a cost-effective option.

There are three main types of Vacuum excavation services used today.

They are jet rodders, vacuum trucks, and sucker trailers.

Vacuum trucks are convenient for various tasks, and their configuration makes them an exceptional “mobile” solution for dealing with waste and construction.

The reason for using a vacuum is to give added protection for utilities, which is often termed “soft digging.” Vacuum excavation utilizes a large trailer or truck-mounted vacuum to remove the earth to expose utilities and structures. There are many equipment manufacturers, and the units come in varying sizes and capabilities. There are two different types of vacuum units, those that use Fans and those with PDs, positive displacement pumps. This comprises the suction side of the truck, which functions between ½ to 1 Atmosphere, 15 to 28 inches of mercury, and suction volumes between 1000 and 3000 cfm.

The other side of the truck is the pressure side of the equipment, which is used to dislodge the soil for removal by the vacuum. The pressure side can be either wet or dry. That is, the removal agent is either water or air. Water usage is often termed hydro excavation, and it utilizes the application of pressurized water, 1500 to 2500 psi, while air usage is termed dry and operates at around 200 to 225 psi. Water volumes typically run around 8 GPM while air is about 200 CFM.

As the material is removed by applying water or air, the vacuum sucks it up, and the material is stored on the truck in a tank. Tanks typically run between 3 and 10 cubic yards depending on the size of the truck chassis and the equipment on the car. The purpose of using water or air is to remove the material around the utilities in the excavation so that they can be measured and sometimes inspected. In addition, water generally leaves a much cleaner site, and, in some cases, the print on pipes can be read, which serves as a superior method of identification.

Care must be used around excavation using vacuums as the suction creates a powerful force. In addition, it is advisable to place temporary barriers to warn and impede pedestrians from wandering into the work area.

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Published 6 months ago