No person shall knowingly rent a dwelling or dwelling unit to be occupied by children under six years of age which has been posted and ordered cleared of harmful lead base substances in accordance with Section 44-53-1430. If the presence of lead base paint or other surface-coating materials is unsuspected and becomes known when the dwelling or dwelling unit is already rented to a family with children under six years of age, the family of the children shall not be evicted for that reason unless a court order is issued pursuant to Section 44-53-1470(2). The owner and occupant of the dwelling or dwelling unit shall be given written notice by the director or his representative advising of the existence of such substances in the dwelling or dwelling unit and ordering that within thirty days such lead base substances be removed, replaced or securely and permanently covered.