Section 60.193 - Standard for visible emissions(a) On and after the date on which the performance test required to be conducted by § 60.8 is completed, no owner or operator subject to the provisions of this subpart shall cause to be discharged into the atmosphere: (1) From any potroom group any gases which exhibit 10 percent opacity or greater, or(2) From any anode bake plant any gases which exhibit 20 percent opacity or greater.