Since most tanks used on farmsteads are bare steel, tank corrosion or piping problems will cause leaks sooner or later. If your tank is more than 20 years old, make a special effort to determine whether leaks exist. Even when a tank has been tested and proven tight, existing regulations and good practice require that you have a method for regularly detecting leaks. You should install such internal or external monitoring methods as groundwater monitoring wells, vapor monitoring, automatic tank gauging, or other approved methods. Measuring tank inventories is an inexpensive and easy way to help detect leaks.
Leakage is apparent when there is any unexplained decrease in the fuel level.
Inventory measurement will not detect very small leaks, but it will at least provide a warning that further checking may be necessary. The closer the tank is to the farmstead's drinking water well, the more important it is to ensure that an adequate leak-detection system is in place. You should take whatever actions are safe and necessary to correct the problem and prevent fire and explosion hazards and follow any further instructions obtained when you report the spill. The ADEQ administers the Petroleum Storage Tank Trust Fund, which can reimburse tank owners for a substantial percentage of costs incurred in cleaning up a problem for federally regulated tanks. Residential and farm underground fuel tanks with less than 110 gallons capacity and aboveground fuel tanks with less than 1320 gallons capacity are not federally regulated and are, therefore, not eligible for this assistance.