In recent years, potable water holding tanks require inspections after several incidents of tank explosions due to over-pressurization and/ or tank defects.   Steel tanks are very common in Florida. What many owners do not know is that unless the tank is stainless or galvanized in design, a liner covers the interior exposed steel.   Just like primer and paint protect the outside of the tank from the elements, a lined tank protects the steel from heat, water, chlorine and more.   However, a liner may not last as long as its outside counterpart.   Part of an inspection is to verify the integrity of the tank wall (thickness, weld seams, etc), but to also verify that the liner has not deteriorated to the point replacement being required to protect the tank.   Most tank failures are not explosive, but pinpoint… where the interior of the tank deteriorates until the tank has a pinhole leak.   Once pinholes appear, the end of life for a tank is near, and often becomes unsafe to continue its use.   Therefore, a tank inspection and relining can be very cost effective, especially in light of regulations requiring ASME- rated tank replacements.  

As a part of each inspection, the inspector should be certified, measure steel thickness, clean the tank and disinfect the tank before refilling.   Bacteriological testing is required before putting the tank back in service, or a Boil Water Notice is required.   Proper notification of DEP personnel before and after the event is also required.