Meet pipeline industry’s new best friend, the hydro-vac excavator. There’s no fanfare surrounding this humble machine, but when it comes to excavating near pipelines and minimizing environmental disruption – this piece of equipment leaves the others all wet.
Hydro-excavation is the science of digging with water, eliminating the very real danger of puncturing a pipeline containing natural gas or other petroleum products. The cutting-edge technology minimizes disruption to the environment, keeping excavation to a minimum, and allows for easier reclamation.
The hydro-vac, or suction excavator, as it is sometimes known, is a self-contained unit on wheels that digs using pressurized water , up to 3000 PSI, to be specific. The powerful water blast is delivered through a steel lance with small stationary or rotating nozzles at the end to surgically convert solid ground into mud, which is quickly sucked up by a powerful truck-mounted vacuum and delivered into a storage tank.
The system uses clean water for excavation projects and confines debris to localized areas, eliminating runoff. Hydro-vac operators say the system makes excavation work safer and reduces the possibility of environmental spills, accidents, and injury.
It is a safe, non-destructive and extremely cost-efficient method of excavating around underground utilities or just excavating in critical areas that are otherwise inaccessible, according to its manufacturers.
It takes at least two specialists to operate a hydro-vac and safety is a major consideration. Kirk Johnson, who works for the pipeline industry, said the hydro blast doesn’t damage pipes, but it can cut right through flesh and muscle tissue. “It’s always prudent to have a third guy standing by the kill switch,” said Johnson. “The vacuum itself is extremely powerful too,” he added.
The pipeline industry usually contracts hydro-excavation projects out to specialized companies with experienced operators, although it is possible to rent the units if needed.
As one might imagine, hydro-vac equipment is in high demand in The Pipeline Crossroads of the World, also known as Cushing, Oklahoma. “It’s really handy,” said Ashley Casey, whose family has owned and operated hydro-vac equipment for over a decade. Their small family operation recently merged with a much larger national company. “We do lots of pipeline maintenance which calls for hydro excavation. And we do special projects,” said Casey.
Casey works as a field supervisor and sometimes fills in as a “swamper,” someone who works in the trenches that are being excavated.
The process of exposing, identifying or gaining access to buried pipelines or utilities is referred to as “pot holing.” These holes can be just a few inches or as large and as deep as is necessary to get the job done, said Casey.
Sloping, benching and grading can also be accomplished using hydro-excavation, but when it comes to excavating in hard-to-reach places or under existing pipeline configurations, the hydro-vac is second to none, according to Johnson.
“The great thing is that the cuts are clean, precise and ready for inspection or whatever further work is required,” said Johnson. “The debris tank is usually dumped between one to three times a day.”
Hydro excavation is also used to expose buried phone lines, fiber optics and anything else located underground. The machines can go to a depth of 100 feet and can access work areas up to 250 feet away from the unit, said Johnson.
Today, hydro excavation is increasingly used in Canada, the United States, Europe and Australia. Proponents say it is the safest, quickest and most cost-effective means of excavating around known and unknown pipelines and other underground utilities.
The pipeline industry isn’t the only place where the units are in use. Municipalities have been utilizing them for manhole and culvert clean outs. They are also used in construction and building remediation.