No person owning or having possession or control of any oil well within the City shall maintain or allow to exist thereon any moving parts or machinery-in-use or intended to be used at such oil well, unless such machinery or moving parts are securely enclosed by an adequate noncombustible ventilated type security fence, screen, or housing sufficient to prevent the entry of unauthorized persons. Such security fence or screen shall be not less than 5 feet high, and if equipped with gates, such gates must not be less than 5 feet high and equipped with adequate hardware to prevent the entry of unauthorized persons. A single adequate security fence, screen, or housing may be used to enclose more than one oil well. Security fences, screens, or housings required by this subsection shall be approved by the Chief.
EXCEPTION: This subsection shall not apply if a competent person is in constant attendance, 24 hours a day, at each oil well.