3406.4.5.8 Underground Tank Location

Underground tanks shall be located such that the top plate thereof shall be at least 2 feet (610 mm) below the established grade. No such tank shall be buried within 10 feet (3048 mm) of any building or adjoining property line. Individual underground tanks shall be covered with 2 feet (610 mm) of earth or 4 inches (102 mm) of reinforced concrete extending 10 feet (3048 mm) beyond all the vertical walls of the tank, and the excavation made to receive the tank shall be backfilled with well-compacted clean sand or earth, free of any ash or other corrosive substance, and free from stones larger than will pass through a 1-inch (25-mm) mesh. Underground tanks may be erected in groups of 2 or more, when such tanks are separated by a space of 1 foot (305 mm), and provided the reinforced concrete top cover extends unbroken over the open space between the tanks.