The risks of falling, asphyxiation, drowning, and cave-ins are realties when performing excavation and trench work. Be sure to follow these safety guidelines from the California Division of Occupational Safety and Health:

1. Provide daily inspection of excavations, protective systems, and adjacent areas to prevent potential hazards such as soil instability, air toxicity, and equipment failure.
2. Under California Code of Regulations Article 6, Section 1541, a "competent person" must be present on site while work is being performed at all times.
3. If a trench is more than 4 feet deep, a ladder, ramp, or other means of access must be within 25 lateral feet of workers.
4. Shoring or other means of protection must be present on excavations 5 feet or deeper and must be installed from the top down and removed from the bottom up.
5. Materials, equipment, and excavated material (spoils) should be at least 2 feet away from the edge of the excavation site.
6. Use retaining devices, such as a trench box that will extend above the top of the trench, to prevent equipment and spoils from falling back into the excavation site.
7. Idling vehicles are not allowed near excavation sites; exhaust fumes can settle inside the trench, putting workers at risk of asphyxiation.
8. Heavy machinery cannot be operated above slopes, cuts, banks and cliffs when employees are working below.
9. Excavation sites should be barricaded around the perimeter.
10. Emergency rescue equipment, such as breathing masks, safety harnesses, or basket stretchers, should be readily available when hazardous conditions exist or are expected to develop during excavation.
11. When evidence of a potential cave-in is present, all work near and around the work site must be stopped until a registered professional engineer determines it is safe to resume work.
12. No work should ever start unless permits are obtained and appropriate safety precautions are taken to keep employees safe.