Vacuum Excavation

What Vacuum Excavation Is Used For

The most common job is proving underground services before anything else goes in the ground. A pothole exposes the service so its depth, alignment, size and condition can be measured and recorded, rather than estimated from a plan that may be decades old. Potholing follows the service plans and electronic location and confirms what they say, and that record is what lets the designer, the drill crew or the excavator operator work with confidence.

Every geotechnical, environmental or water bore hole we drill on a live site starts the same way. Our NDD crews concrete core through slabs and pavements from 60 to 500 mm and vacuum the hole down past the service depth before the drill rig is set up over it. That is standard practice for us in car parks, road reserves and rail corridors, and against existing buildings.

Where a new service has to cross or run beside existing ones, a vacuum excavated slot trench exposes the existing assets and keeps them intact while the new one goes in. The same units clean out pits, catch basins and valve boxes, and reach spoil in places an excavator bucket cannot, such as under pipework, inside plant rooms or at the bottom of a deep pit. On contaminated sites the spoil goes straight into a sealed tank rather than into a pile on the ground.

Air or Water

We run both. Air vacuum excavation uses compressed air to loosen the ground and lifts dry spoil into the tank. Because the spoil stays dry it can go straight back into the hole as backfill once the work is done, which suits potholing where the ground is to be reinstated the same day, and it is the method we use most.

Water, or hydro, excavation cuts faster in hard, compacted or clay ground and is the choice for deeper holes and tougher conditions. The trade-off is wet spoil that has to be carted away rather than returned. Our crews pick the method for the ground and the reinstatement, not for the truck that happens to be free.

Trucks and Trailers, 1,000 to 5,000 Litres

Our fleet runs from 1,000 litre trailer units through 3,000 litre and 5,000 litre trucks. The trailer units fit sites a truck cannot reach: rear yards, basements, tight laneways and inside buildings, where they work alongside our tight access drill rigs. The 3,000 and 5,000 litre trucks carry the spoil volume for trenching, a run of potholes in a day and deeper excavation, without repeated trips to tip.

Why It Matters on a Live Site

A strike on a power cable, a gas main, a water main or a fibre trunk stops the site, puts people at risk, and brings repair costs and penalties that dwarf the cost of proving the service first. Mechanical excavation and hand digging both carry that risk wherever the plans are incomplete, and on older sites in Sydney they usually are. Vacuum excavation removes the guesswork about what sits in the first few metres, which is why it is written into the safe work method for drilling and excavation on most commercial, infrastructure and utility projects.

Part of a Drilling Package or On Its Own

On our own drilling jobs the NDD crew is part of the package. They clear the holes ahead of the rig, and the geotechnical, environmental or water bore crew follows without waiting on a separate contractor. On many sites that combined approach is the more efficient way to complete an incident free program on time and on budget.

We also provide vacuum excavation as a stand-alone service to civil contractors, utilities and consultants, and our plant hire fleet includes vacuum loaders and non destructive excavation trucks and trailers for wet and dry hire.

Talk to BG Drilling about vacuum excavation on your site. Tell us what has to be exposed or cleared, the ground, the access, and whether it sits ahead of a drilling program, and we will tell you which unit and method suit. Get in touch.