Vacuum Excavation & Hydro Excavation 101
Every day, contractors, municipalities and utilities excavate for installation of underground facilities, or must locate existing pipes, cables and lines for maintenance and repairs. In the past, this usually involved digging by hand (often a slow and tedious process) or with a mechanical excavator, backhoe or similar machine. Every year, there are numerous reports of injuries, deaths, explosions and fires from unsafe or poorly planned excavations that strike underground facilities or result from collapsed trenches. Many of these incidents can be avoided and the risks minimized by utilizing techniques such as hydro excavation services.
Two Types of Excavation Processes
Vacuum Excavation:
Vacuum excavation is a general term that may include processes using either water (hydro-excavation) or high-pressure air to loosen soil. In either case, an air vacuum is used to move the loose soil and rocks, often into a debris tank for later disposal or back-filling the hole that’s been made.
Hydro Excavation:
Hydro-excavation is a process that utilizes pressurized water to break up and remove the soil via air conveyance (vacuum) into a debris tank, providing a non-destructive means to safely locate utilities and precisely excavate an area.
Hdyro Excavation Services History
Hydro-excavation as we know it today can trace its growing popularity to the Canadian oil and gas industry, which realized years ago the efficiency of using a hydro-excavation machine to “daylight” buried gas pipes and other utility lines. With cold weather and permafrost, petrochemical plants and facilities in Canada found that using heated water made hydro-excavation the only viable option to excavate year-round. In the early 1960s, catch basin cleaners were adapted for hydro-excavation use, but the technology was crude. Vactor® built its first hydro excavation services machine, the “ExcaVactor,” in 1969. However, the market then was immature and it was the only unit built. In the 1970s and ’80s, customers modified vacuum trucks and sewer cleaners for hydro-excavation use. Some took vacuum components off the trucks and mounted them on all-terrain vehicles to get into remote locations. In the 1990s, a number of companies saw a growing demand for hydro excavation machines and began manufacturing truck- and trailer-mounted units in varying configurations.
By 2000, hydro excavation services were widely used across Canada and were moving into the United States. In recent years, the practice has rapidly gained acceptance in the U.S.
Government Regulation
The U.S. presently has more than 14 million miles of buried utilities and pipes. Current laws prohibit the use of mechanical means to dig within 18 inches of buried cable and pipe in the U.S., and 45 cm in Canada. Buried utilities are often mis-marked or maps are inaccurate, requiring underground facilities to be located by sight, either by hand-digging or another means, to maximize safety. This is often called “daylighting.” Unfortunately, digging by hand is often time-consuming, and mechanical excavation is inherently risky.
*information obtained from Hydro-Excavation: A safe, cost-effective alternative for underground construction and municipal use
Alternate names for Hydro Excavation
- Vacuum excavation
- Hydro excavation
- Air knifing
- Soft dig
- Daylighting