Cathodic Protection Systems Thermo-Scan provides a full range of cathodic protection services on underground metallic structures such as natural gas piping and storage tanks using experienced personnel certified by the National Association of Corrosion Engineers.  Services are provided on-call for natural gas, steam, and water systems and include flame ionization leak detection, the interval barhole survey and mapping of intensity levels of underground leakage. Emergency services are available—call 1-800-481-5748. How Thermo-Scan provides Cathodic Protection Cathodic protection is an electrical method of preventing corrosion on steel structures. Galvanic anodes, which have a higher energy level than steel, can be connected to a coated steel structure to protect it against corrosion. The electrical current flows from the anode through the soil to the steel structure to be protected. As current flows onto the structure from the soil, the energy level of any exposed metal is raised to a point at which no more corrosion will occur on the structure. As the anode releases current, it corrodes to protect the steel. Zinc, magnesium and steel all have unique levels of inherent electrical potential. Because zinc and magnesium have higher electrical potentials, they can be connected to the steel structures to protect against corrosion of a tank or pipe. EPA Regulations EPA Regulations require that all UST systems equipped with cathodic protection systems must be inspected for proper operation by a qualified cathodic protection tester within six months of installation and at least every three years thereafter.  All municipal systems must meet State and Federal D.O.T. regulations. Contact the appropriate regulatory agencies for compliance information.