At any public garage or gasoline service station, storage facilities for gasoline, oil or other flammable materials in bulk over 75 gallons shall be located wholly underground and no nearer than thirty (35') feet from any lot line other than any street side line. No gasoline or oil pumps, oil or greasing mechanism or other service appliance installed for use at such premises shall be within fifteen (15') feet of any street side line and no gasoline pump shall be located or permitted within any enclosed or semi-enclosed building.