Ill. Admin. Code tit. 35, § 217.244
a) On and after January 1, 2015, no person shall cause or allow emissions of NOx into the atmosphere from any reheat furnace, annealing furnace, or galvanizing furnace used in iron and steel making to exceed the following limitations. Until July 1, 2025, compliance must be demonstrated with the applicable 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.
| Emission Unit Type | NOx Emissions Limitation (lb/mmBtu) Before July 1, 2025 |
| Reheat furnace, regenerative | 0.18 |
| Reheat furnace, recuperative, combusting natural gas | 0.09 |
| Reheat furnace, recuperative, combusting a combination of natural gas and coke oven gas | 0.142 |
| Reheat furnace, cold-air | 0.03 |
| Annealing furnace, regenerative | 0.38 |
| Annealing furnace, recuperative | 0.16 |
| Annealing furnace, cold-air | 0.07 |
| Galvanizing furnace, regenerative | 0.46 |
| Galvanizing furnace, recuperative | 0.16 |
| Galvanizing furnace, cold air | 0.06 |
| Emission Unit Type | NOx Emissions Limitation (lb/mmBtu) On and after July 1, 2025 |
| Reheat furnace, cold air | 0.03 |
| Reheat furnace, regenerative and recuperative | 0.09 |
| Annealing furnace, cold air | 0.07 |
| Annealing furnace, regenerative and recuperative | 0.08 |
| Galvanizing furnace, cold air | 0.06 |
| Galvanizing furnace, regenerative and recuperative | 0.08 |
b) On and after January 1, 2015, no person shall cause or allow emissions of NOx into the atmosphere from any reverberatory furnace or crucible furnace used in aluminum melting to exceed the following limitations. Until July 1, 2025, compliance must be demonstrated with the applicable 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.
| Emission Unit Type | NOx Emissions Limitation (lb/mmBtu) |
| Reverberatory furnace | 0.08 |
| Crucible furnace | 0.16 |
(Source: Amended at 49 Ill. Reg. 6355, effective April 23, 2025)