Cal. Health and Safety Code § 41950

(a) Except as provided in subdivisions (b) and (e), no person shall install or maintain any stationary gasoline tank with a capacity of 250 gallons or more which is not equipped for loading through a permanent submerged fill pipe, unless such tank is a pressure tank as described in Section 41951, or is equipped with a vapor recovery system as described in Section 41952 or with a floating roof as described in Section 41953, or unless such tank is equipped with other apparatus of equal efficiency which has been approved by the air pollution control officer in whose district the tank is located. (b) Subdivision (a) shall not apply to any stationary tanks installed prior to December 31, 1970. (c) For the purpose of this section, “gasoline” means any petroleum distillate having a Reid vapor pressure of four pounds or greater. (d) For the purpose of this section, “submerged fill pipe” means any fill pipe which has its discharge opening entirely submerged when the liquid level is six inches above the bottom of the tank. “Submerged fill pipe,” when applied to a tank which is loaded from the side, means any fill pipe which has its discharge opening entirely submerged when the liquid level is 18 inches above the bottom of the tank. (e) Subdivision (a) shall not apply to any stationary tank which is used primarily for the fueling of implements of husbandry.