Hydro Excavation vs Air Excavation

Hydro excavation and air excavation are two types of nonmechanical, minimally invasive vacuum excavation techniques used to loosen soil and dig a hole for a wide range of applications. Both techniques are commonly used when hand digging would take too long but using heavy machinery could cause costly damage, which makes them popular for utility location. While both options can be used for similar jobs, the ideal choice often hinges on the job size, job site location, type of soil involved, time factors and various other issues.

How Vacuum Excavation Works

Experienced excavation contractors use specialized equipment that digs with high-pressure water or air to break apart the soil. Then the excavated material, called spoil, is sucked out through a hose using a high-speed vacuum and placed in a debris tank. This debris may be disposed of or used to backfill the hole later, depending on the method used and job requirements. The preciseness of vacuum excavation offers many perks over traditional excavation methods.

Perks of Hydro and Air Excavation

Hydro excavation and air excavation offer some of the same perks and can be used in similar situations. Both require less manpower and are less invasive and more accurate than conventional excavating. Both also provide a cleaner work area and minimal disruption to traffic flow while offering a much safer work environment by eliminating accidental utility line damage and trench cave-ins. Locating underground lines, cables or pipes using either technique has made hydro and air excavation popular options because there’s almost no risk of damaging existing utilities from cracks or breaks that commonly occur using metal tools during mechanical digging.

Excavating with Water Versus Air

While there are many similarities, there are also distinct differences when comparing the benefits of hydro versus air excavation. Hydro excavation is considered the most efficient type of vacuum excavation because water will always cut through soil and dig faster than air. Speed can be vital when a large job needs completed as quickly as possible. There are also certain applications a hydro excavation contractor can complete that simply can’t be done using pneumatic excavation. Here are some other key differences that further confirm that hydro excavation is often the best choice.

  • One of the biggest differences is how the spoil material can be used. In air excavation, contractors can reuse the spoil for backfilling holes. The spoil can’t be reused in hydro excavation and must be hauled away if there isn’t anywhere to dump it on-site. However, if you need minimal to no backfilling, this generally becomes a nonissue.
  • Soil conditions are the primary concern when choosing the right equipment. Depending on the type of soil being excavated, air might not be able to get the job done. High-pressure water is much more aggressive than air, allowing it to cut through nearly any type of soil with the right nozzle. While air works great for loose soil, water is the clear choice for dense, rocky, compacted or frozen soil and clay.
  • Deep excavations can also hamper pneumatic digging. Air excavation works better in dry soils, which could limit you to shallow digs. If excavation contractors must dig to deeper levels, the area may include wet loamy clay and underground moisture that hamper how well air excavation works. Wet conditions won’t slow down hydro equipment.
  • Certain aspects of hydro excavation could slow you down, such as the need for a nearby water source to refill water tanks and time spent hauling vacuumed debris off-site when you’re unable to dump on-site. However, the speed of hydro excavation is so significantly faster that you generally make up for any extra time spent doing these tasks and still get jobs completed more quickly than you would with air.
  • Water is a natural lubricant, so hydro excavation equipment tends to last longer with less wear on the vacuum hose and other components when compared to air excavation equipment. Hydro excavation also doesn’t blow sand around as air excavation does, which creates a sandblasting effect in the immediate area. Blowing sand can inadvertently damage something near the excavation site and cause equipment components to fail prematurely.

Overall job requirements ultimately guide your choice between hydro excavation and air excavation. If the excavation is relatively small, the soil is loose, water isn’t readily available and the area must be backfilled immediately, then air may be the more desirable option. If you’re dealing with a large and/or deep excavation over hard or frozen ground, hydro excavation is still the way to go, even when faced with spoil and water limitations.

Trust Expert Hydro Excavation Contractors

Earthworkz Construction is a full-service hydro excavation contractor offering precise, professional vacuum excavation in Kansas City. We can help you decide whether hydro excavation is the right choice for you. Our principal owners have over 20 years of combined experience in vacuum excavation, and our reputation as one of the most respected contractors in the region is why our customers choose us over our competitors. Contact us at 816-355-0280 to discuss the merits of hydro vacuum excavation today.