What is the main function of cathodic protection systems on USTs?

The primary function of cathodic protection systems on underground storage tanks (USTs) is to prevent corrosion of metallic structures. Corrosion is a significant concern for USTs because they are often made of steel or other metals that can degrade when exposed to moisture, soil, and various environmental conditions. The cathodic protection system works by making the metallic structure of the tank the cathode of an electrochemical cell, which significantly reduces the rate of corrosion.

This is achieved using methods that can either involve sacrificial anodes that corrode instead of the UST itself or impressed current systems that use an external power source to provide a constant flow of electrons to the tank. By effectively mitigating corrosion, cathodic protection systems help ensure the integrity and longevity of the tank, which is crucial for preventing leaks and environmental contamination.

The other options might address aspects related to USTs, but they do not pertain directly to the protective purpose of cathodic systems. Enhancing storage capacity pertains to tank design and construction rather than protective measures. Monitoring fuel levels is a function of other systems used in conjunction with USTs to ensure operational efficiency and safety. Providing backup power is unrelated to the protective needs of the tank against corrosion.