5.2.2 Sacrificial Anode System
Sacrificial anodes must be able to maintain a standard protection threshold reading of at least negative 850 millivolts.
Any sacrificial anode system that is determined to be failing, the cause of failure shall be investigated and the necessary repairs made to the system within 90-days of the failed reading.
If this time-frame cannot be met, then the entire tank system must be emptied of all product such that there is no more than 1 inch of residue, or 0.3 percent by weight of the total capacity of the tank system remaining within the tank. The tank shall remain empty of product until all repairs are completed.
The tank must also be protected against floatation caused by flooding or soil saturation. Any piping, pumps, man-ways, etc. attached to the tank system must be secured to prevent tampering or unwanted access. Any attached vent lines must be left open and functioning.