Retrofitting is necessary when testing determines that installed anodes do not provide sufficient voltage to cathodically protect the system.

• A. Retrofitting is not needed unless there is a leak
• B. Retrofitting is necessary when testing determines that installed anodes do not provide sufficient voltage to cathodically protect the system
• C. Retrofitting is only for new installs
• D. Retrofitting is required if the soil is dry

Answer: (B)

Cathodic protection relies on a measurable voltage from the anodes to protect the metal, and testing that voltage shows whether protection is adequate. If the test shows the installed anodes aren’t delivering enough voltage to reach the required protection level, retrofitting is needed to restore protection. Retrofitting means enhancing the system by adding, relocating, or upgrading anodes, adjusting wiring, or changing to a more effective anode material so the structure achieves the proper potential and remains protected from corrosion. Leaks are not the trigger for retrofitting, and retrofitting isn’t limited to new installations; dry soil can make protection more challenging but doesn’t by itself dictate retrofitting—it's the test result showing insufficient voltage that drives the action.