1. a) On and after January 1, 2015, no person shall cause or allow emissions of NO_x into the atmosphere from any glass melting furnace to exceed the following limitations. Until July 1, 2025, compliance must be demonstrated with the emissions limitation on an ozone season and annual basis. On and after July 1, 2025, compliance must be demonstrated with the applicable emissions limitation on a 30-day rolling average basis.

   Product	Emission Unit Type	NOx Emissions Limitation (lb/ton glass produced) Before July 1, 2025
   Container Glass	Glass melting furnace	5.0
   Flat Glass	Glass melting furnace	7.9
   Other Glass	Glass melting furnace	11.0

   Product	Emission Unit Type	NOx Emissions Limitation (lb/ton glass produced) On and after July 1, 2025
   Container Glass	Glass melting furnace	4.0
   Flat Glass	Glass melting furnace	7.0
   Other Glass	Glass melting furnace	4.0

2. b) Before July 1, 2025, the emissions during glass melting furnace startup (not to exceed 70 days) or furnace idling (operation at less than 35% of furnace capacity) will be excluded from calculations for the purpose of demonstrating compliance with the seasonal and annual emissions limitations under this Section, provided that the owner or operator, at all times, including periods of startup and idling, to the extent practicable, maintain and operate any affected emission unit, including associated air pollution control equipment, in a manner consistent with good air pollution control practice for minimizing emissions. The owner or operator of a glass melting furnace must maintain records that include the date, time, and duration of any startup or idling in the operation of the glass melting furnace.

(Source: Amended at 49 Ill. Reg. 6355, effective April 23, 2025)