Hydro Excavation

Hydro excavation, also called hydrovac excavation, is performed using a specialized truck equipped with a water system and a vacuum system. The operator directs a pressurized water jet at the ground to loosen and liquefy the soil, while a large-diameter vacuum hose simultaneously suctions the mud slurry into a debris tank mounted on the truck.

The technique originated in the Canadian oil sands region in the 1990s, where pipeline density made mechanical excavation extremely dangerous. It has since become the industry standard for excavation near buried utilities across North America. Hydro excavation is faster than air excavation in most soil types, particularly clay and compacted soils, and produces a cleaner, more precise excavation.

Water pressure is typically adjustable from 1,000 to 3,000 PSI, with operators reducing pressure as they approach known utility lines. The vacuum system typically produces airflow of 3,000 to 6,000 CFM, sufficient to lift heavy soil and water slurry through the dig tube and into the debris tank. Heated water systems allow hydro excavation to be performed in frozen ground conditions.