Automatic line leak detectors must detect a release equivalent to how much at 10 lbs per square inch?

The correct answer is 3 gallons per hour (gph) at a pressure of 10 pounds per square inch (psi) because this value is aligned with regulatory requirements for automatic line leak detectors used in underground storage tank systems. These detectors are designed to provide early warning of leaks in the piping connected to the tanks.

At a pressure of 10 psi, the standard for leak detection is typically set to identify a potential leak rate of 3 gph to ensure that any releases are promptly detected before they can pose a significant risk to the environment or public safety. The chosen threshold balances the need for sensitivity to leaks with practical limitations of detection technology and maintenance concerns.

The other choices reflect levels of detection that are either below or above the accepted standard for this specific pressure setting. Hence, they do not align with the required performance criteria for ensuring the integrity of the storage system.