Why this matters
Use this leader guide before vacuum excavation & utility potholing work to review the real setup, the controls that need to be in place, and the conditions that should stop the task. Excavation conditions can change between one trip into the trench and the next. Soil, water, vibration, nearby loads and utilities all affect whether the protective system and access are still suitable. A competent-person inspection is a control, not a formality.
A scenario to discuss
The excavation was acceptable at the morning inspection, then Vacuum Excavation & Utility Potholing continues after rain, vibration, new spoil placement, water seepage, or nearby equipment changes the condition. What must the competent person re-evaluate before workers enter or remain in the excavation?
Before work starts
- Confirm the competent-person inspection is current and review soil, water, adjacent loads and protective system.
- Verify utilities are located/marked and conflicts are resolved before digging or entering.
- Confirm safe access/egress and keep spoil, equipment and materials controlled near the edge.
- Verify utility marks, tolerance zones and the approved exposure method before potholing begins.
- Control high-pressure air/water and vacuum hoses so they do not injure workers or damage the utility being exposed.
Common failure points
- Entering after conditions changed without a new competent-person evaluation.
- Allowing spoil, equipment, water or vibration to load or destabilize the excavation.
- Treating utility marks or old drawings as a substitute for field verification.
Safe work sequence / controls
- Verify utility marks, tolerance zones and the approved exposure method before potholing begins.
- Control high-pressure air/water and vacuum hoses so they do not injure workers or damage the utility being exposed.
- Treat every exposed line as active until its identity and status are confirmed.
- Manage spoil/slurry and the opening so workers, pedestrians and equipment cannot fall or drive into it.
Stop and reset the plan if...
- The competent-person inspection has not been completed or conditions have changed since the inspection.
- Water, cracking, sloughing, vibration, adjacent loads or utility conflicts appear.
- Required protective systems, safe access/egress or edge controls are not in place.
Questions worth asking the crew
- What did the competent person find in the latest inspection, and has anything changed since that inspection?
- What protective system is being used, and does the actual depth, soil, water, and adjacent loading still match the plan?
- Where is safe access/egress, and can every worker reach it without crossing an uncontrolled hazard?
- What sign of cracking, sloughing, water, vibration, utility conflict, or equipment surcharge means everyone gets out?
- Has anyone seen a trench/excavation condition change after the morning inspection? What was the first sign that required another competent-person look?
Make it real on the job
Walk the edge with the competent person and point out protective system, access and changing conditions.
Close the talk
Before the crew starts, everyone should be able to explain the hazard, point to the control being used today, and name the condition that would make the work stop.
Related authoritative reference
OSHA 29 CFR 1926.651 - Specific Excavation Requirements · Open reference ↗
This is a practical discussion guide, not a substitute for required training, a competent person, permits, manufacturer instructions, employer procedures, or applicable federal/state/local requirements. Adapt it to the actual task and conditions.
