It shall be unlawful for any person to cause or permit junk, scrap metal, scrap lumber, wastepaper products, discarded building materials, or any unused, abandoned vehicle, vehicles or abandoned parts, machinery or machinery parts, or other waste materials to be in or upon any yard, garden, lawn, outbuilding or premises in the city, unless in connection with a business enterprise lawfully situated and licensed for the same. (Prior code § 18-25-53)