When the SPCC regulations were up-dated in 2002, my employer jumped on the bandwagon and I learned I was responsible for over 450 tanks ranging from 3-80 years of age, of all materials, shapes, sizes and condition of fitness. Some facilities were built by me, from the ground up and in full compliance with all applicable codes. Some were inherited from people who did everything wrong that could be done wrong. Some were well maintained. Some had been repaired so poorly the repairs themselves had ruined the tank. But mostly I was faced with an average cross section of tanks with ordinary maintenance.
13 years later, I have performed nearly 2000 inspections, seen many tanks as solid as the day they were installed, some that required only a few simple repairs to insure another 20 years of service, and a very few that were condemned, the result of corrosive chemicals, poor installation, and very high sludge levels. The condemned tanks were nearly always facility surplus; repairable for much less than the cost of a new installation, but simply not needed. Your problem tank is probably saveable.
Tank inspection should be cost effective, efficient, and fit into your schedule. I understand those priorities, can work with your resources, and we can get this done. We can help maintain the value and reliability of your facility. We just need to start.