External corrosion control: Cathodic protection.

(a) Each cathodic protection system required by this subpart must provide a level of cathodic protection that complies with one or more of the applicable criteria contained in appendix D of this part. If none of these criteria is applicable, the cathodic protection system must provide a level of cathodic protection at least equal to that provided by compliance with one or more of these criteria. (b) If amphoteric metals are included in a buried or submerged pipeline containing a metal of different anodic potential— (1) The amphoteric metals must be electrically isolated from the remainder of the pipeline and cathodically protected; or (2) The entire buried or submerged pipeline must be cathodically protected at a cathodic potential that meets the requirements of appendix D of this part for amphoteric metals. (c) The amount of cathodic protection must be controlled so as not to damage the protective coating or the pipe.