Which of the following is NOT part of the requirements for monitoring underground piping?

Using manual monitoring methods is the correct choice as it is not specifically part of the regulatory requirements for monitoring underground piping. Regulations related to underground storage tanks place significant emphasis on using automated or electronic monitoring systems, such as line leak detectors, which are designed to provide more immediate and accurate detection of leaks. These systems are often considered essential for ensuring compliance with safety standards and environmental protection.

In contrast, having a line leak detector is a crucial requirement that facilitates the early detection of leaks in the piping system, thus preventing potential environmental contamination. The annual line tightness test is also a mandated practice to ensure that the piping integrity is maintained over time, further supporting safety protocols. Maintaining operational records is critical for regulatory compliance and tracking the maintenance and performance of the UST systems, enabling operators to demonstrate adherence to required standards.

Overall, while manual monitoring methods can provide some level of oversight, they do not meet the comprehensive criteria established for effective leak detection in current regulatory frameworks.