(1) An entity providing funding for the private cleaning of sidewalks under a written agreement covering one or more City blocks may erect and maintain, during the term of the agreement, signs on each block covered by the agreement indicating that the entity has adopted the block for sidewalk cleaning, provided:
(a) A copy of the agreement is filed with the Streets Department, and the Streets Department finds, after any necessary consultation with the Law Department, that the agreement provides for adequate cleaning services on the blocks covered by such agreement;
(b) The size, number, location, design and construction of the signs are approved by the Streets Department, which may reserve the right to direct the entity to remove any signs in the future if necessary to accommodate public safety; and
(c) The signs are erected and maintained by such entity at no cost to the City.
(2) The Streets Department shall promulgate any regulations necessary to carry out the provisions of this Section.