It shall be unlawful to excavate or construct any sewer treatment works or to construct or maintain any sewer pipes or conduits used for the treatment of sewage or for the discharge or conveyance of sewage, or related substance, so that such sewage or other similar substance would be conveyed into any ditch, stream, creek or channel or into any subterranean waters of the City, unless a permit has been obtained therefor from the City Council upon a showing by the Director of Public Works that such construction and operations will not be materially detrimental to the public welfare.
('65 Code, § 29-4) (Ord. No. 516)