Slot Trenching

Slot Trenching: common questions

What is Slot Trenching?+

Slot trenching is digging a narrow, precise trench with hydro excavation, commonly used to install conduit, expose long runs of utility, or create clean utility corridors with minimal surface disruption.

When is slot trenching with a hydrovac a better choice than a mechanical trencher?+

Hydrovac slot trenching makes sense when the trench runs through a congested utility corridor, crosses marked lines inside a tolerance zone, or passes near tree roots, foundations, or finished hardscape. A mechanical trencher is usually faster in open ground with no nearby utilities. Many crews combine both, using the hydrovac only on the sections where striking a line is a real risk.

How is a slot trench different from a pothole?+

A pothole is a single vertical hole that exposes one point on a buried utility so its depth and position can be checked. A slot trench is a linear cut that runs along or across a route, used to place conduit or cable or to expose a line along its length. Both are dug with vacuum excavation, but a pothole checks one point on a line, while a slot trench follows or crosses a route, either to find and expose a line along its length or to open a path for new conduit or cable.

What happens to the soil removed during slot trenching?+

The spoils are pulled into the hydrovac's debris body as slurry and hauled to an approved disposal or decanting site. Wet slurry usually cannot be reused as backfill right away, so trenches are often backfilled with imported material that meets the project spec. Rules for hydrovac slurry disposal vary by state and municipality, so confirm an approved site before the job starts.