If a source of contaminant is located within 10 feet of an intake opening, such openings shall be located a minimum of how many feet below the containment source?

• A. 2
• B. 5
• C. 10
• D. 15

Answer: (A)

When a contaminant source is close to an intake, you create a small vertical offset to protect the outdoor air being pulled into the system. Placing the intake a short distance below the source helps prevent the immediate plume from being drawn straight into the system, taking advantage of how air moves and mixes near the source. This tiny separation acts as a safety buffer, reducing the chance that vapors will enter the ventilation before they disperse. In this scenario, the minimum vertical offset specified is two feet. This keeps the intake out of the most concentrated portion of the release while avoiding the need for larger relocations.