To determine if Dave has enough experience to be a competent person for excavation work, you need to assess whether he meets the definition of a "competent person" as defined by OSHA [1]. A competent person is someone who:

1. Is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees [1].
2. Has the authorization to take prompt corrective measures to eliminate these hazards [1].

To determine if Dave is a competent person you must evaluate his knowledge and ability to recognize hazards related to the specific excavation site, and his authority to correct those hazards. Some factors to consider include:

• Soil Type and Stability: Can Dave assess soil conditions and identify potential cave-in hazards? [1]
• Protective Systems: Does Dave understand the requirements for protective systems like sloping, shoring, and shielding? [2]
• Underground Utilities: Can Dave identify and locate underground utilities before excavation? [3]
• Hazardous Atmospheres: Is Dave able to test for and recognize hazardous atmospheres, such as low oxygen levels or flammable gases? [4]
• Water Hazards: Can Dave recognize and address hazards associated with water accumulation in the excavation? [5]
• Inspection Procedures: Is Dave capable of performing daily inspections of the excavation, adjacent areas, and protective systems for any evidence of potential hazards? [6]

If Dave can demonstrate these abilities and has the authority to take corrective actions, he can be considered a competent person. If there are any doubts about Dave's competence, it may be necessary to provide him with additional training or supervision.