Vacuum Excavation: Five Best Practices for Exposing Utilities and Avoiding Damage Underground

Contributed by Chapman Hancock, Ditch Witch product manager, vacuum excavation

Featured in: Dig Different

With new utility projects on the rise, damage prevention continues to be a growing concern for the underground construction industry. Especially in developed urban areas, new utilities share the ground with other existing fiber, gas, electric, water and sewer lines. The congested underground space leaves little to no room for error.

To mitigate underground utility damage, some cities require operators to expose parallel utilities near the projected bore path using soft excavation. Regardless of regulations, revealing nearby utilities using soft excavation is an industry-wide best practice. Today’s versatile vacuum excavators are an increasingly popular method for exposing underground utilities on congested, urban projects.

Here are five best practices for safely and efficiently exposing utilities with vacuum excavation.

1. Use a rotating nozzle

Water can be a powerful source – and the conduit or polyurethane on a utility isn’t invincible. A rotating nozzle, also known as an oscillating nozzle, is the only nozzle that should be used for exposing utilities. This type of nozzle does not have a direct spray which can damage utilities. Also, it delivers a constant stream of circulating water that pulls away more dirt and can use up to 50 percent less water than a fan nozzle. Essentially, the oscillating water stream maintains safety without sacrificing productivity.

2. Don’t exceed 3,000 psi

The recommended pressure for soft excavation is between 2,500 to 3,000 psi. Although many vacuum excavators and nozzles offer higher psi capabilities, too much pressure can damage utilities. If using heated water, pressure should be reduced.

3. Stay at least eight inches from the utility

Holding the nozzle too close to the utility also increases the risk of damage. The recommended distance is six to eight inches from the utility.

4. Keep the nozzle moving

Although the rotating nozzle keeps the intense stream of water from remaining in constant, direct contact with the utility – it’s important to physically move the lance/nozzle around, as well. Keeping a rotating stream of water during excavation avoids applying excessive pressure to a single area and, in turn, reduces damage.

5. Never dig with the nozzle

As tempting as it may be to push the nozzle into the dirt, this can clog the nozzle and decrease efficiency. If you’re struggling to expose utilities in hard soil or heavy clay, hot water heater packages are an option with most vacuum excavators. Using hot water can help break down clay without applying additional water pressure. However, keep the temperature below 150 degrees Fahrenheit and reduce pressure to avoid damaging utilities.

In addition to putting crews at risk, failing to properly expose utilities can have a costly consequence. After damaging a utility, underground construction companies can face devastating fines and reparation costs.

Operators can apply these best practices to limit unanticipated costs and delays on underground projects while maintaining jobsite safety and productivity.

For more information, visit

Used for construction and demolition, our breakers can be used to break up asphalt, concrete or even clay. The hydraulic hammer is perfect for any small or medium job you might have. More up-time in the field is always the goal, and with only two moving parts and a few seals, there’s no reason for down-time.
Compatible Models

SK600, SK800, SK900, SK1050, SK1550, SK1750


Best suited for irrigation and fiber installation, the Rock Saw attachment can effortlessly cut through rock, concrete, and other tough materials with unmatched precision. 

Compatible Models

SK1050, SK1550, SK1750

Easily move materials for rebuilds, new construction, footings, utility repairs and more with this compact and versatile attachment.
Compatible Models

SK800, SK900, SK1050, SK1550, SK1750

Featuring a heavy-duty boom design, powerful stump grinding attachments quickly shred stumps down to nothing. Easy maneuvering from stump to stump and increased visibility turns more ground stumps into more profit.
Compatible Models

SK600, SK800, SK900, SK1050, SK1550, SK1750, SK3000

Your multipurpose tool for the ultimate multi-tasker is here. Engineered to grab tight to heavy materials and move them with ease and precision, the multi-task tool is your go-to for heavy applications. Easy to operate with convenient, functional levers.
Compatible Models

SK600, SK800, SK900, SK1050, SK1550, SK1750

With the MC-450 coring attachment, utility maintenance is simple and less disruptive. Featuring intuitive controls and an integrated water tank, the MC-450 is the perfect choice for quick cuts and a more productive coring process. A fully adjustable 0 to 280 rpm speed allows for enhanced control and greater productivity.