The provisions of this subpart are applicable to discharges resulting from the process by which raw materials are melted in a furnace and processed by hand into pressed or blown glassware. This includes those plants which:
(a) Produce leaded glass and employ hydrofluoric acid finishing techniques,
(b) Produce non-leaded glass and employ hydrofluoric acid finishing techniques, or
(c) Produce leaded or non-leaded glass and do not employ hydrofluoric acid finishing techniques.