(a) A rotating biological contactor (RBC) may be used in conjunction with other treatment as a dual treatment system.     
      (b) An RBC may be used as aroughing unit, as described in §217.182(b)(1) of this title (relating to Trickling Filters--General Requirements, regarding trickling filter classifications), in series with an activated sludge system.     
      (c) The engineering report must include supporting data, calculations, process descriptions, and vendor information to describe how a proposed RBC system will meet the permitted effluent limitations.     
      (d) Combined systems may be subject to the requirements of §217.7(b)(2) of this title (relating to Types of Plans and Specifications Approvals).     
     Source Note:        The provisions of this §217.187 adopted to be effective August 28, 2008, 33 TexReg 6843; amended to be effective December 4, 2015, 40 TexReg 8254