During a final plumbing inspection for a new restaurant, the inspector identifies a trap in the kitchen that is not provided with an individual vent. Instead, it relies on a connection to a vent that also serves another fixture located upstream on the same branch. What type of venting method is most likely being incorrectly applied or missing required components?

Question: During a final plumbing inspection for a new restaurant, the inspector identifies a trap in the kitchen that is not provided with an individual vent. Instead, it relies on a connection to a vent that also serves another fixture located upstream on the same branch. What type of venting method is most likely being incorrectly applied or missing required components?

Answer options:

• Circuit venting
• Stack venting
• Wet venting ✅ Common venting

Correct answer: Common venting

Explanation: If a trap relies on a vent that also serves another fixture upstream, and it's not designed as a proper circuit or wet vent, it's likely an attempt at common venting. Common venting typically serves two fixture traps by means of a single vent pipe. If components like vent size or fixture configurations are incorrect for common venting, or if it was intended to be an individual vent, it would be a code violation. The scenario describes a situation where a vent serves 'another fixture located upstream on the same branch', which is characteristic of the setup for common venting, but if not implemented strictly to code, it would be flagged.