Interior Lining Combined With Cathodic Protection
Another option for upgrading existing tanks is to add both cathodic protection and interior lining. If these upgrade options are added at the same time, the advantages of this combined method are: USTs receive greater corrosion protection and the condition of the interior lining does not require periodic inspection.
These advantages can amount to significant cost savings over interior lining alone. However, the cathodic protection system must periodically be tested and inspected to ensure that it is working properly. You must keep records of these tests and inspections.
If internal lining and cathodic protection are placed on an UST at different times, please see EPA's guidance in the UST Technical Compendium in the New and Upgraded Systems section, Question #14, for whether periodic inspections of the lining are needed.