How Does Hydro Excavation Work? Why Many Choose This Method?

Hydro excavation is a safe and non-destructive way to remove storm water, sludge, sewer blockages, building site waste, slurry and other wet and dry wastes. High-pressure water penetrates and loosens the soil. Then, the air vacuum lifts the waste (and gets transferred into a tank for later disposal).

As a result, hydro vacuum excavation is the preferred method of many engineers for safe digging. Aside from safety, this method also prevents damages to subsurface infrastructure (including underground pipes and cables). The resulting excavation will also be faster. In addition, there will be lower costs for repairs and restorations after the job.

Where can we apply vacuum excavation?

It’s actually a versatile non-destructive method of digging. It has already found useful applications in:

  • Potholing (digging a test hole to expose underground pipes and cables, including their horizontal and vertical locations)
  • Faster commencement of utility repairs and replacements (due to early exposure)
  • Slot trenching (preparing narrow trenches where pipes and cables are to be installed)
  • Removal of debris (the vacuum excavator’s precision prevents damage to surrounding areas)
  • Cold weather digging (some trucks might be equipped with heaters to break up ice and frozen soil)
  • Remote digging (the truck can be placed a bit far from the site if the work area is tight or congested)


Hydro excavation is especially valuable in finding and exposing utilities. After all, this type of task requires speed and accuracy. Underground utilities must be located fast if there’s a need for immediate repair or replacement. The accuracy is also important so as to minimise damages and prevent injuries and hazards to workers.

With accurate and timely utility mapping, the workplace will be safer for the crew. They will successfully avoid hazard points and proceed with the work much faster. They’ll also prevent causing inconveniences to the nearby homes and businesses. This is crucial in speeding up the progress of the project.

Aside from minimising inconveniences, hydro excavation also allows for minimal environmental impact. We’ll further discuss this later as we explore more about how vacuum excavation works. This is to better understand its mechanism and how it contributes to better safety.

More information on how hydro excavation works

This method takes advantage of high pressure water to loosen up soil. As a result, it could be more confined and more controlled compared to traditional methods of digging. Aside from the high pressure water, a vacuum should be created to allow for suction and removal of waste and soil from the subsurface.

Vacuum creation can be accomplished through the use of a fan system. It can successfully remove the air and create the vacuum. As a result, there will be a viable mechanism for wastes and debris to go up.

The wastes will then go straight to the tank for later disposal. It’s a straightforward method of removing the waste and debris. There will be minimal exposure to the workers. In addition, the community will be spared from the potential hazards brought by excavation. In contrast, the use of a backhoe (or other traditional digging methods) may expose workers and the neighbourhood to hazardous wastes.

Upfront and long-term benefits

Due to its straightforward mechanism, many engineers have already realised its better damage and safety control. Any type of excavation carries a lot of risks. There’s the risk of accidentally damaging underground water pipes and electricity cables. There’s also the risk of releasing hazardous wastes to the air.

Hydro vacuum excavation can significantly reduce those risks, thereby promoting better safety to both the workers and the community. Moreover, there will be minimal or zero damages to surrounding utilities. Faster progress will then be accomplished for the excavation or construction project.

There are long-term benefits as well. For instance, insurance and liability costs may be greatly reduced because of better safety and minimal damages. There will also be lower costs and a shorter time period required for site repairs after the excavation. These could ultimately lead to the company’s better profitability and established reputation.

How much does hydro excavation services cost?

It widely varies and the total cost may depend on the following factors:

  • Site accessibility
  • Extent of the task and assignment (e.g. extensive digging, large-scale waste removal)
  • Hours required to complete the job (it could be based on a per-hour rate)
  • Conditions of the site (e.g. different geological features and soil compositions, weather)


Hydro excavation could be more expensive than traditional digging methods. However, the better safety and damage control provided by vacuum excavation methods greatly offset the additional costs. As discussed earlier, there are both upfront and long-term cost savings related to hydro excavation (lower site repair costs, faster excavation, zero injuries and damages, minimal environmental hazards).

Possible hazardous wastes underground

Digging carries a lot of risks because the dormant hazards might be disturbed and brought up accidentally. Some of those hazards might be in the form of:

  • Heavy metals
  • Dangerous pathogens
  • Radiation
  • Chemicals


For instance, improperly disposed batteries and leftover paints might have accumulated underground. Disturbance and agitation might release some of the fumes above the surface. This could then harm the workers and disturb the community.

The wastes underground may come from the following facilities and other sources:

  • Hospitals
  • Laboratories
  • Agricultural activities (pesticide and fertiliser runoffs)
  • Natural occurrences (e.g. flooding and soil erosion)
  • Construction
  • Manufacturing
  • Modern lifestyle (usage and dumping of pharmaceutical and cosmetic products)


It’s also the case when storage tanks are accidentally damaged during excavation. There might be remaining amounts of fuel which may cause leaks and explosions. Either way, the workers will be exposed to risks. Those risks may then in turn lead to injuries and fatalities.

As mentioned earlier, hydro excavation is a straightforward method wherein wastes are contained from start to finish. There will be minimal exposure and the wastes are directly stored into the tank. This method minimises the risks being faced by site workers and engineers.

Minimal area disruption

The excavation costs often blow up because of the repairs needed after the job (and not the actual excavation itself). That’s because traditional excavation methods often require working on a wider area for the job to be completed. The resulting sloped sides occupy a much larger area than the actual area of concern.

Aside from lengthening the time of excavation, the wider area also results to longer time of site repairs and restorations. Moving large volumes of earth could be a costly and time-consuming process. This could further extend the work scope and job timeline. Additional labour costs are also to be expected in this case.

In contrast, hydro excavation provides a more direct path to the areas of concern (e.g. buried utilities underground). There will be lower requirements (and possibly fewer permits and hassles to deal with) when scoping an area. After the job, there will be less time and lower costs needed to bring back the landscape to its original condition.

Due to the accuracy and precision of the method, damages to surrounding pipes and cables are also significantly reduced. Both its straightforward and narrow approach makes hydro excavation a clear choice among engineers and project managers.

Summary: How does hydro excavation work & its benefits

High pressure water and vacuum creation are used to successfully remove waste (both wet and dry waste). Its accuracy and precision allow for better safety and damage control. This results to significant savings in time and costs. The company will then realise better profitability and improved reputation.

Many companies contact us here at One Search Locators for their hydro excavation needs. Whether it’s for trenching, removing waste or exposing underground utilities, we prioritise accuracy and safety to reduce damages and injuries.

Contact us today and our experienced professionals will apply non-destructive and non-invasive practices in completing the job.

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