What is Vacuum Excavation?

Vacuum Excavation Truck

Vacuum excavation, also referred to as hydro excavation or non-destructive digging, is the process of combining high-pressure water with an air vacuum. Vacuum excavators are used to remove unwanted material from an area, mainly mud, dirt and slurry from around underground utilities.

What is a vacuum truck? 

Vacuum excavation trucks (which are also known as sucker trucks, suction excavators or vac trucks) are primarily used to safely excavate around cable networks and buried pipelines. Vac trucks can also be used for emergency repair of utility and pipeline networks, rail track maintenance, deep excavation, confined spaces, sewer clearance, clearing around tree roots, basement work and more. They’re also commonly used for environmental maintenance, including clearing away any environmental damage and cleaning blocked gullies and gutters on the street.

Vacuum trucks are unique trucks fitted with a compressed air lance, waste storage chamber, vacuum suction, and twin or triple air vehicle fans. These trucks are used for general excavation work where the soil is broken up and dispersed with a high-pressure, compressed air lance and then sucked back up into the truck to be held for later disposal.

Vacuum excavation trucks are also known as sucker trucks, suction excavators or vac trucks. These vehicles come in a range of different tank sizes with the most common being 3000L and 6000L. There’s really no comparison between conventional excavators and vacuum excavators in terms of efficiency, as vacuum excavators can achieve up to sixteen times the output, depending on the type of materials the machines are working with.

Other uses for vacuum trucks include safely excavating around cable networks and buried pipelines, emergency repair for utility and pipeline networks, rail track maintenance deep excavation, confined space excavation, sewer clearance, clearing around tree roots, basement work and more. Vacuum trucks are also commonly used for environmental maintenance, including clearing away any environmental damage and cleaning blocked gullies and gutters on the street.

Vacuum excavation serves many purposes with the most common centred on digging and collecting dirt around an underground utility or cable, without using traditional digging tools or machines. This process has become popular in recent decades as it alleviates the risks commonly associated with conventional digging via excavator and shovel. Using non-destructive digging techniques like vacuum excavation and hydro excavation has proven to significantly mitigate the risk of line strikes and utility damage, while also decreasing project time, across the world.

Vacuum excavation is an excavation technique that uses a combination of air suction, compressed air lances, and high-pressure water jets to safely expose underground utility cable networks, buried pipelines, and even dated railways tracks for emergency repair, removal, and inspection.

What is vacuum excavation?

Vacuum excavation is a process with a much longer history than many might imagine. It’s believed that during 1850, miners in California worked to remove land masses and gold by using steam pumps to target pressurised water. Move forward a century and miners in cold climates, such as North America, looked for an alternative to standard digging. Standard digging was impossible for many working locations that were often tundra. In this case, hydro excavation was an effective solution with the use of heated water. As the hydro excavation process became more refined, it increasingly became a go-to solution for many excavation projects across Australia and everywhere else.

How does a vacuum excavator work?

The water jetter cuts into and breaks up the soil and the air vacuum then removes the slurry that’s produced from the location into a debris tank. The vacuum source is provided in one of two ways: either through a positive displacement blower or a fan system. The fan system is easier to use. It effectively moves huge amounts of air; this means it delivers faster excavations and is usually both lighter and less expensive than the alternative displacement blower systems.

Vacuum excavators use twin or triple air vehicle fans to create airflow, ensuring the vacuum can pull material inside the intake hose, where it’s transported into the catchment chamber. Sometimes the end of the tube will be toothed which helps to cut into the earth when it’s being used for excavating. From there, the material is sent to the holding tank, while a micromesh filter system captures the dust particles.

In action, you’ll typically find a vacuum truck parked close to the project at hand, typically a location that needs to be dug up to access damaged or redundant utility cables, with the operator utilising a powerful water jet to break up the ground while the suction tube sucks up the dispersed waste, leaving the utility exposed.

What is hydro excavation?

Hydro excavation uses a powerful water jet lance instead of a compressed air lance to help disperse and break apart the ground, generally in efforts to expose subsurface utilities. In layman's terms, think a high-pressure water spray combined with an industrial size vacuum for earthworks. The liquid waste is then sucked up into the truck and typically processed at a soil transfer or disposal plant. Hydro excavation has become an increasingly popular option for non-destructive digging in Australia, where water jetting and suction has proven to be an extremely effective technique when it comes to digging around and exposing utilities efficiently and safely. It is important to note that all hydro excavators should Dial Before You Dig (1100) to ensure there are no services in the location.

What are the benefits of vacuum excavation?

The main benefit of using a vacuum excavator is the minimum damage to existing and underground fixtures of pipework, cabling, and power or other lines. As the work carried out from a vacuum excavator is also more precise and accurate and there is less need for backfilling. Vacuum excavation is more advanced than the traditional digging methods and is a lot safer, as the process is much more controlled. This creates a cleaner workspace as the suction devices excavate the materials but retain them within the storage unit. The speed at which vacuum excavation can extract materials makes it a more cost-efficient solution and using this method is also quicker and does not involve any chemicals making the process of using a vacuum excavator environmentally friendly.

Types of vacuum excavation:

Jet Rodders

Jet Rodding utilises a precision water nozzle on a high-pressure hose, where water is jetted to efficiently clean and remove mud, slush, debris, and soil. Some jet rodders have the power to cut through wood and tree roots, making them extremely handy for clearing stormwater pipes and undertaking non-destructive digging in tree-heavy areas.

Vacuum Truck/Vacuum Tankers

A vacuum truck or vacuum tanker is a truck that has a pump and a tank. The pump is designed to pneumatically suck liquids, sludges, slurries from a location (often underground) into the tank of the truck through suction lines typically 2-4" in diameter.

Sucker Trailers

Sucker trailers are customised trailers with a powerful vacuum to remove heavy debris and materials from a hole or on land. A sucker trailer works the same as a vacuum truck, by pneumatically loading solids, liquids, sludge or slurry. Suck trailers can be mounted either directly onto a truck with the vacuum drive powered by the truck motor, or with an independent motor. 

Purchasing a vacuum excavator for sale can be difficult, check out these manufacturers who provide sucker trucks for sale in Australia.

What are the average rates for vacuum excavation?

Vacuum excavation service rates vary significantly depending on the project type, scale and duration, with additional fees for water consumption and waste disposal (required across Australia). Additionally, suppliers require a 4 hour minimum per hire, where your project may require two operators depending on the scale and scope. iSeekplant have put together this easy to read pricing guide to give you an estimation of vacuum excavation hire costs. These are generalised rates and may vary considerably, so be sure to get a few rates through our directory so you get the best value for your project. 

Typical vacuum excavation hire rates:

  • 3000L - $150 to $175/hour for 1 operator, or $200/hour for 2.
  • 6000L - $200/hour for 1 operator, or $270/hour for 2.
  • 9000L and above - around $220 to $250/hour. 
  • Water usage - fees dependant on the local council. 
  • Waste disposal - typically $6 per cubic metre of waste.


At iSeekplant, our directory offers vacuum excavation hire from suppliers throughout all major cities including Brisbane, Sydney, Melbourne, Adelaide, Perth, Canberra, Hobart, Darwin and hundreds of regional centres throughout Australia, with both wet and dry hire options available. Suppliers at iSeekplant offer a variety of services on top of just the standard vacuum excavation task, including radar utility location and soil transfer to suit your projects needs and operations across the nation. 

If you are thinking you will need vacuum excavation for your next job then get in touch with the iSeekplant team on 1300 691 912 or use our get a quote tool, and we will send your request out to local suppliers in your area.

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