Active gypsum dewatering stack
Active gypsum dewatering stack means a gypsum dewatering stack that is currently receiving gypsum, received gypsum within the last year, or is part of the facility's water management system. A gypsum dewatering stack that is considered closed by a state authority is not considered an active gypsum dewatering stack.
Source
40 CFR § 63.601
Scoping language
Terms used in this subpart are defined in 63.2 of the Clean Air Act and in this section as follows: