Excavation is a necessary part of underground construction. It is a difficult aspect of civil engineering and can be quite disruptive and costly. That’s why there have been several innovations over the years to improve the efficiency and safety of the excavation process whilst reducing cost across the board.

Hydro vacuum excavation is one such innovation. Not only does this relatively new technique improve excavation speed, but it also reduces various safety and health risks.

What is Hydro Vacuum Excavation?

Hydro excavation is a non-mechanical, non-destructive digging technique that utilizes pressurized water with a specialized industry-grade vacuum to excavate soil from the selected area. The pressurized water is used to break up the soil and transform it into a slurry which is then removed with the vacuum and deposited into a debris tank.

How Does it Work?

Following are the steps of the hydro vacuum excavation process:

Bringing the Hydro Evacuation Truck/Unit to the Site

A Hydro excavation truck is the primary ingredient of a hydro excavation project. The excavation unit is mounted on a trailer or a truck. It features a high-pressure water hose, a storage tank for water, a suction hose, and a tank to store the loosened soil.

Injecting the Soil With Water

Whether hydro-excavating or daylighting a hole or a slot trench, the soil is injected with water from the holding tank. Then, the operator uses a specialized wand to direct the water to a precise location. If the excavation is performed during winter when the ground is frozen, a boiler sends hot water via the hose and wand to unfreeze the soil.

Liquefying the Soil

Depending on the soil type, e.g. silty loam, clay, sand, etc., the water starts to break up the soil. Once a certain amount of time is passed, the broken-up soil starts to liquefy into a watered-down, muddy soil known as slurry.

Vacuuming the Slurry

Once the soil becomes loose and consistent, the vacuum unit mounted on the truck sucks it up. Then, the slurry gets transferred into a holding tank for later release.

Hydro-excavating crew have two options when it comes to vacuum, and they make a selection depending on the scope and size of the project. For lighter-duty digging, e.g. hole digging, slot trenching, etc., the crew typically uses a fan system. For heavy-duty excavation, a positive displacement blower is commonly used.

Dumping the Slurry

Once the excavation is completed, the crew takes the slurry to an off-site location to pump it out. Some of these designated sites dewater the slurry to collect and reuse the organic materials found in the soil.

Hydro excavation is an excellent way to dig precision holes without removing excess amounts of soil and disturbing native plants. It features the above-listed process and can be performed virtually any time of the year, making it an attractive option for most underground construction projects.

Contact Sure Search and ask about our Hydro Vacuum Excavation service before you cause unnecessary damage. No job is too big, small or complicated, and we’re happy to tailor our quotes to the project.