This chapter contains sections titled: Sacrificial Anode Cathodic Protection Systems Impressed Current Cathodic Protection Systems Cathodic Protection Current Need Effect of Coatings on Cathodic Protection Effect of Passivation on Cathodic Protection Automated Cathodic Protection Systems Cathodic Protection Criteria Reliability of Cathodic Protection Criteria Interference Effects of Cathodic Protection Systems Criteria for Cathodic Protection Projects Cost of Cathodic Protection Comparison of Cathodic Protection Systems