921.02 DISCHARGE OF STORM WATER; APPROVAL REQUIRED TO DISCHARGE UNPOLLUTED INDUSTRIAL WATERS.
   Storm water and all other unpolluted drainage shall be discharged to such sewers as are specifically designated as combined sewers or storm sewers, or to a natural outlet approved by the Superintendent. Industrial cooling waters or unpolluted process waters may be discharged upon approval of the Superintendent to a storm sewer, or a natural outlet.