Quantifying Effectiveness of Cathodic Protection in Water Mains: Theory

Abstract

Cathodic protection is a viable measure to extend the residual life of water mains and thus defer capital investments in their rehabilitation and renewal. The effectiveness of cathodic protection varies with the unique set of conditions under which it is applied, and it is difficult to confirm or validate whether its application can be considered successful. Therefore, the reported success histories have been largely anecdotal and most often based on the reduction of water main breaks using cathodic protection. This paper describes methodologies and associated models to quantify and assess the performance of cathodic protection programs implemented by water utilities. The effectiveness of cathodic protection programs applied under various conditions can be determined and weighed against their costs in order to maximize the benefit from their implementation. These proposed methodologies and models should assist water utilities to optimize the implementation and scheduling of future cathodic protection programs. A companion paper, “Quantifying Effectiveness of Cathodic Protection in Water Mains: Case Studies,” describes the application of proposed models to assess the impact of cathodic protection programs.