After a repair, within what period should a cathodically protected UST system be tested for proper operation?

The appropriate timeframe for testing a cathodically protected underground storage tank (UST) system after a repair is 6 months. This period is established to ensure that the cathodic protection is functioning effectively after any modifications or repairs have been made. Testing within this timeframe allows for the identification of any issues that may have arisen during the repair process and ensures that the system is adequately protecting against corrosion.

Conducting the test too soon (such as immediately) may not provide a complete and accurate assessment, as the system may need time to stabilize after the repairs. A longer period, such as one year, may delay necessary actions to address any potential problems with the cathodic protection, which is crucial for preventing corrosion and ensuring the longevity and safety of the UST system. Therefore, the 6-month testing requirement strikes an essential balance between prompt assessment and allowing sufficient time for the system to settle after repairs.