Evolution and Impact of the sti-P3® System

Abstract Failure of underground steel storage tanks is due to one primary phenomena - corrosion. Most steel tanks installed during the fifties, sixties, and seventies were installed without adequate corrosion protection and today, threaten our groundwater resources with contamination. However, the sti-P3® system was developed in the late sixties to overcome some of the corrosion protection design inadequacies of those other tanks. The system uses three simple, yet essential corrosion design elements; high quality dielectric coating, electrical isolation, and cathodic protection. A brief history of the system's development is provided with ensuing technological improvements. Quality assurance of key product elements combined with independent random inspections of steel tank fabricators assures a continous high quality product. On site cathodic protection monitoring readings will reinforce a proper tank installation and adequate system design and performance. A recent field study indicated that continuity with other structures, mainly piping, was the primary cause for inadequate cathodic protection readings.