3.1 Sitework and Safety
Key Takeaways
- Excavation questions focus on cave-in risk, competent-person decisions, access, and protective systems.
- Compaction depends on lift thickness, moisture, soil type, and equipment.
- Drainage and erosion controls protect both the site and downstream systems.
- Unknown underground hazards should be stopped and escalated, not worked around casually.
Sitework Logic
Site construction questions often test risk recognition. Excavations can collapse. Wet soil may not compact. Poor drainage can undermine foundations. Unknown utilities or tanks require stopping work and notifying the proper parties.
Sitework Review Table
| Topic | Exam focus |
|---|---|
| Soil classification | Stability and excavation method |
| Protective systems | Sloping, benching, shoring, shielding |
| Compaction | Density, moisture, lift thickness |
| Benchmarks | Known elevation references |
| Erosion control | Keep sediment on site |
| Drainage | Move water away from structures |
| Utilities | Locate before excavation |
Safety Habit
When a hazard appears, choose the answer that controls the hazard before production continues. The contractor may need a competent person, updated plan, utility locator, environmental response, or owner/design-team notice depending on the scenario.
Field Judgment
Good answers usually stop unsafe production before they optimize production speed. If soil is unstable, water enters a trench, a utility is unmarked, or a hazardous material appears, the contractor should control the hazard and notify the right party. NASCLA scenarios often reward risk control over improvisation.
Exam Cue
When the question mentions changing field conditions, check notice, documentation, and hazard-control responsibilities first.
What should a contractor do first after discovering a previously unknown underground storage tank during excavation?