Where liquid delivery to a motor fuel storage tank is accomplished by positive-pressure operation, cargo tanks making delivery shall be positioned a minimum of 25 feet (7620 mm) from tanks receiving flammable liquids and 15 feet (4572 mm) from tanks receiving combustible liquids. During delivery, a cargo tank shall not obstruct a public street, private road, block motorists' view of roadways or impede the movement of vehicles or pedestrians.
The driver, operator or attendant of a cargo tank shall, before making delivery to a tank, determine the unfilled, available capacity of such tank by an approved tank level-indicating device or method. A measuring stick shall not be used to measure the contents of the tank through the fill connection line, except where there is a direct fill connection.
Delivery of liquid motor fuel shall be made by means of approved liquid- and vapor-tight connections between the delivery hose and tank fill pipe. Where tanks are equipped with any type of vapor recovery system, all connections required for the safe and proper functioning of the particular vapor recovery process shall be made. Such connections shall be made liquid- and vapor-tight and remain connected throughout the delivery process. Vapors shall not be discharged at grade level during delivery.