When determined by the chief of environmental health that any building or structure constitutes a rodent harborage, they may serve a notice in writing upon the person occupying and the person owning, in charge of or in control of same to rodentproof such building or structure, or any portion thereof, within a reasonable time. (Ord. 4883-NS § 1 Exhibit A, Ch. 5 Art. 3 § 3, 1976)