(1) Aluminum equivalent. The amount of aluminum which can be produced from the amount of anodes produced by an anode bake plant. This is assumed to equal two tons of aluminum per ton of anodes unless the owner or operator can establish a different number by submitting production records of the amount of aluminum produced and the concurrent amount of anode consumed by potrooms.

(2) Anode bake plant. A facility which produces carbon anodes for use in a primary aluminum reduction plant.

(3) Potroom. A building unit at a primary aluminum reduction plant which houses a group of electrolytic cells in which aluminum is produced. A potroom group consists of an uncontrolled potroom, a potroom which is controlled individually or a group of potrooms or potroom segments ducted to a common control system.

(4) Prebake plant. A primary aluminum reduction plant where anode baking is performed by heating unbaked anode material in a furnace or kiln which is separate from the electrolytic reduction cell.

(5) Primary aluminum reduction plant. A facility where aluminum is produced by electrolytic reduction.

(6) Soderberg plant. A primary aluminum reduction plant where anode baking is performed by heating unbaked anode material within the same casing which contains the working anode while it is immersed in the electrolytic cell.

(7) Total fluorides. Elemental fluorine and all fluoride compounds as measured by methods specified in Appendix A of 40 CFR 60 (see table 1, section 200.9 of this Title), or, if the application for the permit to construct for the source was received by the commissioner before October 24, 1974, as measured by alternative methods approved by the commissioner.