For many decades, it was traditional forms of excavation using hydraulic excavators and backhoes, as well as hand tools to dig around or expose utilities. Operator accidents and underground utility damage were commonplace — especially in crowded, urban development areas. In 2017, over 400,000 excavation accidents were reported in North America, and the pressing need for safer, less invasive equipment could no longer be ignored.
Hydrovac uses high-pressure water to loosen the soil and dig a hole. The wet, muddy excavated material is then suctioned into a tank, mounted on a hydro excavator truck, and carried offsite to a designated dump location. The technology allows for quick and precise excavations which require less backfill, less labor and causes significantly less environmental impact than conventional drilling methods. And most importantly, hydro excavation poses very little threat, if any, to buried utilities.
The growing popularity of hydro excavation started largely in Canada, where cold weather and frozen soil often rendered traditional tools and methods to be ineffective. By utilizing hot water to aid the melting process, hydro excavation came as a godsend for oil & gas, construction and other Canadian industries, and it was a matter of time before United States embraced the safe and highly efficient technology as well.
75% of damages caused in the utility industry are from shovel strikes. The Common Ground Alliance (an association dedicated to ensuring public safety, environmental protection, and integrity of services by promoting effective practices for preventing damage to underground utilities in North America) recognizes both vacuum excavation and hand digging as safe ways to expose utilities. I believe the tone of the CGA will soon change to identify vacuum excavation as the preferred method, grouping hand digging in with mechanical excavation. I also believe we are close to seeing legislation that carries the same message.
The second advantage is higher precision and less restoration. Compared to manual digging, you need much less manpower, so it is cost-effective. Finally, it is less intrusive from an environmental point of view. The excavated dirt is stored in debris tanks, keeping the worksite clean with minimal disruption to traffic.