Hydrovac excavation is a relatively new method of digging that uses pressurized water and a power vacuum system to break down soil. It’s an alternative to mechanical excavation, which relies on heavy machinery such as excavators and tractors. Hydro excavation is non-destructive in comparison and therefore able to safely expose subsurface infrastructure. It’s also less hazardous to personnel due to the reduced risk of cave-ins and other catastrophic events that can occur with mechanical digging.

The things to look for in a hydrovac excavation service include the ability to decrease delays and keep the project going throughout the year. A hydrovac company also needs experience to ensure accurate work while remaining cost-effective. Finally, it must use care to minimize destruction of the property and use the correct safety procedures.

Applications for Hydovac Excavation Services

Hydrovac excavation, also known as hydro excavation, uses a specialized vehicle called a hydrovac truck or trailer. This vehicle has a hose, or wand, that technicians insert into the ground at the excavation site. The wand injects water into the soil under pressure that’s strong enough break up compacted soil, but not strong enough to damage utility lines. The water liquefies the soil into slurry, which the vacuum transports to a tank attached to the hydrovac truck. This soil may then be removed from the worksite, thus keeping the workplace looking tidy.

The best uses of hydrovac excavation are in applications where accuracy and a low impact on the job site are important. This technique is also commonly used for excavating frozen soil by using hot water. The most powerful hydrovac systems can excavate up to 60 feet deep and 600 feet from the equipment.

How to Hire Reliable Hydrovac Excavation Services

Here’s what to look for when you’re ready to hire a company to carry out hydro-excavation work.


Trenching projects often need to be performed efficiently, especially when the site is within a city. Hydrovac excavation is faster than mechanical excavation, resulting in a shorter disruption to residents in the area. Get an estimated completion time and look at a company’s previous jobs to ensure it can work efficiently. The type of equipment it uses can also tell you about a company’s operating speed and efficiency. Finally, customer reviews on social media sites can provide first-hand accounts about the pace of a company’s projects.


Hiring third parties for specialty work like excavation is often the best strategy, since it avoids the need for your own employees to perform work they haven’t been specifically trained for. In addition to the equipment, you should also look at the technicians who will be doing the work to ensure they have the experience needed to handle the entire excavation project. For example, the hydrovac excavation company you select should be able to perform both daylighting and trenching.


The superior accuracy of hydrovac evacuation makes it particularly preferable for small trenching projects with less margin for error. This technique provides greater directional control compared to mechanical excavation, allowing technicians to perform the task more precisely. Accuracy is particularly important for excavation projects such as slot trenching, which involves cutting straight, narrow trenches in the ground. Technicians who perform potholing must also skilled at this task, since they work closely to underground utilities.

Hydrovac evacuation also results in a cleaner site than mechanical excavation because operators can easily deposit debris where they want. Hydrovac trucks typically have tanks that allow them to store the slurry they product and remove it from the excavation site entirely. Once it dries out, this slurry can also be used to backfill trenches to give the property a neater appearance.


A hydrovac company isn’t necessarily cost-effective just because it charges low rates. You should always be wary of an unusually low quote, which often means compromised quality of service. You probably shouldn’t get the most expensive company either, so it’s usually best to look at services that charge somewhere between these two extremes.

Hydrovac excavation is generally more expensive than mechanical excavation based strictly on a per-dollar basis. However, you must also consider other factors to determine hydrovac excavation’s true cost-effectiveness. For example, mechanical excavation is typically five to seven times slower than hydrovac excavation, which increases the overall cost of the project due to delays and additional manual labor.

Care on the Job

Contractors should demonstrate respect for their client’s property in all aspects of construction, especially excavation. Hydrovac excavation is generally much less destructive to the site than mechanical excavation, but improper use of the equipment can still result in unnecessary damage.

Technicians should never use more than 3,000 pounds per square inch (PSI) of pressure during hydrovac excavation, as higher pressure can damage underground utilities. This figure assumes the technician is using a rotating nozzle, which disperses the force of the water. In the case of a straight nozzle that forces water directly into the soil, the pressure shouldn’t exceed 2,500 PSI. The maximum pressure that hydrovac technicians should use is even less when they reach 18 inches below the surface, at which point the pressure shouldn’t exceed 1,500 PSI. Furthermore, the water used in hydrovac evacuation should never be heated to more than 115° F.

Learn more about Potholing Methods with Hydro Vacuum Excavation.

Excavating Services that You Can Trust

Underground Services, also known as SoftDig®, provides a full range of Subsurface Utility Engineering (SUE) services throughout the United States. We maintain a fleet of vacuum excavation trucks in the Mid-Atlantic region and Texas that provide minimally invasive excavation services. Contact SoftDig today to find out more about our hydrovac excavation services.

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