(a) Whenever the city furnishes and operates a lawn waste dumping site, such site shall be used only to provide a location for the dumping of grass clippings and leaves.
(b) Whenever the city furnishes and operates a burn site, such site shall be used only to provide a location for the dumping of tree limbs, shrubs, lumber (without nails or other fasteners) and other burnable materials which do not produce heavy smoke.
(c) Any such city operated lawn waste dumping site or burn site shall be open between 7:00 a.m. and 8:00 p.m. each day of the week.
(d) It shall be unlawful to dispose of any materials other than those specified above for each type of site.