Confined Space

OSHA defines a confined space under 29 CFR 1910.146 as a space that is large enough for an employee to enter and perform work, has limited or restricted means of entry or exit, and is not designed for continuous employee occupancy. When a confined space contains or has the potential to contain a hazardous atmosphere, engulfment hazard, or other serious safety hazard, it is classified as a permit-required confined space.

Deep hydrovac excavations can become confined spaces if they are deep enough for a worker to enter and have walls that restrict movement. Utility manholes, vaults, and pits that are accessed during hydrovac operations are frequently classified as confined spaces. Before any worker enters a potential confined space, atmospheric testing for oxygen levels, flammable gases, and toxic gases must be performed.

Confined space entry requires a written permit, a trained entry team including an attendant stationed outside the space, rescue provisions, continuous atmospheric monitoring, and communication systems. Many hydrovac companies train their employees in confined space entry procedures and maintain rescue equipment on their trucks, though some opt to avoid confined space entry entirely by performing all work from outside the excavation.