Corrosion impact of cathodic protection on surrounding structures

Corrosion has been around for all of recorded history. Cathodic protection is the electrical solution to the corrosion problem. The history of cathodic protection is traced. The design fundamentals are developed. This includes the three components of a corrosion system, the three elements of an electric circuit, and the three configurations causing potential difference. Cathodic protection is the process of forcing a metal to be more negative (cathodic) than the natural state. Three case studies investigate unintended side effects from cathodic protection problems. One is from a pipeline crossing a lake. Another is a pipeline in very rocky soil. The third is a well casing in dry clay. Technical ramifications are involved when bonding of electrical grounding systems to metal protected by cathodic protection. Installation and maintenance requirements are identified. A compendium of applicable standards and recommended practices is presented.