No person shall discharge or cause to be discharged any storm water, surface water, groundwater, roof run-off, sub-surface drainage, uncontaminated cooling water, or unpolluted industrial process waters to any sanitary sewer. Storm water and all other unpolluted drainage shall be discharged to such sewers as are specifically designated as storm sewers or to a natural outlet approved by the Superintendent. Industrial cooling water or unpolluted process waters may be discharged on approval of the Superintendent, to a storm sewer or natural outlet.