The document provides the background for EPA's technical support for selecting and developing proposed treatment standards for the constituents to be regulated for the electroplating and metal heat treating wastes. Sections 2 through 7 present information for the F-code wastes. Section 2 describes the industries affected by regulation of these wastes, explains the processes generating these wastes, and presents available waste characterization data. Section 3 specifies the applicable and demonstrated treatment technologies for these wastes and presents descriptions of those technologies. Section 4 contains performance data for the demonstrated technologies, and Section 5 analyzes these performance data to determine BDAT for each waste. In Section 6 the rationale for selection of regulated constituents is presented, and in Section 7 the proposed BDAT treatment standards are calculated for the regulated constituents selected. Section 8 discusses associated inorganic cyanide P-code wastes and details the development of the proposed treatment standards for these wastes.