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Introduction

As early as 1943, an AWWA technical committee concluded it was necessary to control corrosion of submerged surfaces inside water tanks. At that time, cathodic protection was identified as an effective way to prevent leaks. It wasn't until the 1970s, however, when practical designs for water storage tanks were widely introduced, that cathodic protection began to gain widespread use to prevent corrosion.

Even the best protective coating systems cannot prevent corrosion indefinitely. When cathodic protection is added to a coated tank, however, the advantage achieved by combining the benefits of a protective coating with cathodic protection is significant for owners, doubling or even tripling the life of the coating. Consequently, tank owners view cathodic protection as a low-cost way to safeguard investments in their storage tanks and protective coating systems.

By pairing protective coatings and cathodic protection, it is possible to extend the life of a typical steel water storage tank's coating system for immersion service by as much as 20 years. Without cathodic protection, system failure is likely to occur within 10 years.