California Designated Operator Practice Exam

Under what circumstance can manual tank gauging be used for existing underground tanks?

1. If the total system capacity exceeds 1,000 gallons

2. If the total system capacity is less than 2,000 gallons

3. If the tank is regularly tested every month

4. If the tank is maintained by a certified professional

The correct answer is: If the total system capacity is less than 2,000 gallons

Manual tank gauging can be utilized for existing underground tanks specifically when the total system capacity is less than 2,000 gallons. This method is permitted under certain conditions as part of leak detection requirements mandated by environmental regulations. For smaller tanks, manual gauging serves as a practical and economical option, allowing operators to monitor fuel levels without the need for more advanced and costly equipment. The reason that the threshold is set at less than 2,000 gallons relates to the perceived lower risk of leaks and spills associated with smaller tanks, as they are typically easier to manage and monitor. On the other hand, tanks with a capacity exceeding 2,000 gallons usually require more sophisticated leak detection methods to ensure compliance with regulations due to their potential environmental impact. Regular testing or maintenance by a certified professional, while important for overall tank safety and compliance, does not specifically dictate the appropriateness of manual gauging for tanks of certain sizes.