Chemical Tank & Secondary Containment Action Checklist

Four Responses, Not Two

Most plants treat a below-minimum-thickness finding as binary — fix it now, or ignore it and hope. There's a real third option: reduce the tank's allowable fill level while a repair is scheduled, lowering hydrostatic stress on the thinned shell course. It's a documented interim measure, not a workaround — but it has to be decided and written down, with a name and a date attached, not left implied.

External Readings Confirm. They Don't Explain.

A second, third, or fourth external ultrasonic reading below minimum thickness tells you the problem is still there — it doesn't tell you how fast it's progressing, or exactly where the worst pitting sits. That's what an internal inspection is for. A tank with no documented corrosion rate can't have a real inspection interval calculated for it; the interval becomes a guess.

"Secondary Containment" Isn't One Number

Petroleum storage, hazardous waste tanks, and general chemical storage each have their own governing code — EPA's SPCC rule, RCRA's tank standard, or state/local fire code, depending on what's stored and where. The number that matters is whichever one actually governs your tank, not a percentage copied from a different facility.

This guide reflects LibertyCES's own specification experience as of September 2026. Every facility's actual requirements are set by its own governing code, permit, and engineer of record — confirm directly before acting.