For wallboard dryers, calcining mills, calciners, and gypsum rock dryers firing natural gas, the NOx RACT requirements shall be as follows:

1. (a) An emission limit of 0.10 lb. per million Btu, based on an hourly average; or
2. (b) Implement NOx RACT control technology as specified in Env-A 1310.02(b).

Source. (See Revision Note at chapter heading for Env-A 1300) #9803, eff 10-31-10; ss by #12584, eff 8-15-18