What is a permissible minimum distance for a tank over 1000 USWG from the property line, adjacent concrete or masonry building wall with no openings within the specified clearances, or a source of ignition?

• A. 10 ft, 15 ft, or 25 ft from property line, adjacent concrete or masonry building wall with no building openings within the specified clearances, or source of ignition.
• B. 2 ft from property line
• C. 5 ft from property line
• D. 50 ft from property line

Answer: (A)

For LPG storage, safety setbacks are specific to what you’re measuring to: ignition sources, an adjacent building wall, or the property line. A tank over 1000 USWG must be kept at least 10 feet away from any ignition source, 15 feet away from a concrete or masonry building wall with no openings within the required clearances, and 25 feet away from the property line. These distinct distances reflect the different risks at each reference point—heat and flame exposure, vapor intrusion into openings, and boundary protection. Since the question asks for the minimum distances for each reference, the correct answer lists all three values: 10 ft from ignition, 15 ft from a solid wall, and 25 ft from the property line. The smaller options (2 ft, 5 ft, 50 ft) don’t match the mandated clearances for this tank size.