(1) Every storage container shall be equipped with a liquid level gauging device by which the level of liquid in the storage container can be readily and safely determined.

(2) A liquid level gauging device is not required if the level of liquid in a storage container can be reliably measured by other means.

(3) Liquid level gauging devices shall be secured, in a safe manner, to protect against breakage or vandalism which may result in a discharge.

(4) External sight gauges are prohibited unless they are equipped with an automatic shut-off valve.