Ind. Admin. Code tit. 326, r. 10-7-8 – Source-specific emission limitations

Authority: IC 13-14-8-1; IC 13-14-9; IC 13-17-3-4

Sec. 8. (a) Carmeuse Lime, Inc., whose source identification number (source ID) is 089-00112, in Lake County shall operate and maintain rotary kilns EU-1 through EU-5 in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(b) United States Steel Corporation Gary Works, whose source ID is 089-00121, in Lake County shall comply with the following emissions limits:

(1) No. 3 Recycling plant shall comply with the following:

(A) The units shall operate using only Fives North American Combustion, model HiRAM 4575-14 low-NOx burners, or the equivalent, for reheat of the windbox exhaust.

(B) No. 3 Recycling Plant shall be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(2) Blast Furnaces No. 4, No. 6, No. 8, and No. 14 shall comply with the following:

(A) Each group of blast furnace stoves shall:

(i) receive ninety percent (90%) or more of its total gas volume from blast furnace gas as fuel on a rolling thirty (30) operating-day basis; and

(ii) be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(B) Each casthouse and flare shall operate in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(3) No. 1 Basic Oxygen Process (BOP) Shop, including Vessels M, E, and D, shall operate in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(4) No. 2 Q-BOP Shop, including Vessels W, Y, and T, shall operate in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(5) The reheat furnaces and waste heat boilers shall operate in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(6) No. 4 Boiler House boilers No. 1, No. 2, and No. 3, and Turboblower Boiler House boilers No. 1 through No. 3 and No. 5 shall comply with the following:

(A) For Boiler House No. 4, boilers No. 1 and No. 2, NOx emissions from each boiler shall not exceed 0.08 lbs/MMBtu when firing natural gas or blast furnace gas and 0.10 lb/MMBtu when firing fuel oil with compliance demonstrated on a rolling thirty (30) operating-day basis.

(B) For Boiler House No. 4 boiler No. 3 and the Turboblower Boiler House boilers, NOx emissions shall not exceed 0.17 lbs/MMBtu from each boiler on a rolling thirty (30) operating-day basis.

(C) The Boiler House units shall operate in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(7) Turboblower Boiler House boiler No. 6 shall comply with the following:

(A) NOx emissions shall not exceed 0.20 lbs/MMBtu on a rolling thirty (30) operating-day basis when firing natural gas only.

(B) NOx emissions from combusting blast furnace gas and natural gas shall not exceed 432.21 tons per twelve (12) consecutive month period with compliance determined at the end of each month.

(1) install low-NOx burners in sodium silicate furnace EU-01;

(2) not allow NOx emissions to exceed 8 lb/per ton of product following the installation of the low-NOx burners in sodium silicate furnace EU-01; and

(3) following installation of the low-NOx burners, the owner or operator shall conduct a NOx emissions test utilizing methods approved by the Commissioner to confirm compliance with the limit.

(d) Cleveland-Cliffs Burns Harbor, LLC, Gary Plate, whose source ID is 089-00118, in Lake County shall comply with the following emissions limits:

(1) North and South Hardening Furnaces and North and South Tempering Furnaces shall:

(A) operate using only natural gas as fuel; and

(B) be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(e) Cleveland-Cliffs Steel, LLC, Indiana Harbor East, whose source ID is 089-00316, in Lake County shall comply with the following emissions limits:

(1) Boilerhouse No. 5, including Boilers 501 through 504, shall comply with the following:

(A) NOx emissions shall not exceed 0.17 lb/MMBtu from each boiler on a rolling thirty (30) operating-day basis.

(B) Each boiler shall receive ninety percent (90%) or more of its total gas volume from blast furnace gas in any twelve (12) consecutive month period with compliance determined at the end of each month.

(C) Boilers shall be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(2) Blast Furnace No. 7, also known as Blast Furnace IH7, shall comply with the following:

(A) The blast furnace stoves shall:

(i) receive ninety percent (90%) or more of its total gas volume from blast furnace gas as fuel on a rolling thirty (30) operating-day basis; and

(ii) be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(B) Each casthouse and flare shall operate in accordance with manufacturer's specifications and good operating practices for the control of NOx emissions.

(3) No. 4, Basic Oxygen Furnace (BOF), No. 50, and No. 60 shall operate in accordance with good operating practices for the control of NOx emissions.

(4) The Recycling Plant shall be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(5) Lime Plant No. 1, including Kiln 1 and Kiln 2, shall be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(6) 80" Hot Strip Mill Walking Beam Furnaces No. 4, No. 5, and No. 6 shall comply with the following:

(A) Each furnace shall be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions and use only natural gas as fuel.

(B) NOx emissions from the Walking Beam Furnaces shall not exceed 357 pounds per million cubic feet of natural gas.

(i) No. 4 Walking Beam Furnace shall operate using low-NOx burners.

(ii) NOx emissions from No. 5 Walking Beam Furnace shall not exceed 286 tons per twelve (12) consecutive month period with compliance determined at the end of each month.

(iii) NOx emissions from No. 6 Walking Beam Furnace shall not exceed 283.9 tons per twelve (12) consecutive month period with compliance determined at the end of each month.

(7) No. 3 Continuous Anneal Line shall conduct tune-ups of burners as required by 40 CFR 63.7540(a)(10)*.

(f) Cleveland-Cliffs Steel, LLC, Indiana Harbor West, whose source ID is 089-00318, in Lake County shall comply with the following emissions limits:

(1) Boiler No. 6 through 8 shall comply with the following:

(A) Each boiler shall operate using only blast furnace gas, natural gas, or a blend of blast furnace gas and natural gas as fuel.

(B) NOx emissions from No. 6 Boiler and No. 7 Boiler shall not exceed 0.17 lbs/MMBtu from each boiler on a rolling thirty (30) operating-day basis.

(C) The owner or operator shall conduct tune-ups in accordance with 40 CFR 63, subpart DDDDD* and paragraph 10-7-3(c) of this rule.

(D) Natural gas heat input to No. 6 Boiler and No. 7 Boiler shall not exceed 2.62 x 10⁶ MMBtu per twelve (12) consecutive month period, each, with compliance determined at the end of each month.

(E) The following requirements apply to No. 8 Boiler:

(i) Cleveland-Cliffs Steel, LLC shall install low NOx burners with overfire air in No. 8 Boiler.

(ii) NOx emissions from No. 8 Boiler shall not exceed 0.08 lb/MMBtu.

(iii) Following installation of the low-NOx burners and overfire air, the owner or operator shall conduct a NOx emissions test utilizing methods approved by the commissioner to confirm compliance.

(2) Blast Furnace No. 3, also known as Blast Furnace IH3, and Blast Furnace No. 4, also known as Blast Furnace IH4, shall comply with the following:

(A) Each group of blast furnace stoves shall:

(i) receive ninety percent (90%) or more of its total gas volume from blast furnace gas as fuel on a rolling thirty (30) operating-day basis; and

(ii) be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(B) Each casthouse and flare shall operate in accordance with manufacturer's specifications and good operating practices for the control of NOx emissions.

(3) Basic Oxygen Furnace No. 1 and No. 2 shall operate in accordance with good operating practices for the control of NOx emissions.

(4) No. 2 Galvanizing Line including the Galvanizing Furnace and Flame Furnace shall comply with the following:

(A) operate using only natural gas as fuel;

(B) conduct tune-ups of burners as required by 40 CFR 63.7540(a)(10)*; and

(C) operate in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(g) Indiana Harbor Coke Company, LP, whose source ID is 089-00382, in Lake County shall comply with the following emissions limits:

(1) Each coke oven battery, including coke oven battery A through D, shall:

(A) operate only as heat-recovery coke oven battery using staged combustion inherent to its design;

(B) operate using only natural gas as fuel when supplemental heating is necessary; and

(C) be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(h) BP Products North America, Inc., Whiting Business Unit, whose source ID is 089-00453, in Lake County shall comply with the following emissions limits:

(1) NOx emissions from:

(A) No. 11A Pipe Still Heater H-1X, Heater H-2A and Heater H-3, combined, shall not exceed 80.7 tons in a twelve (12) consecutive month period with compliance determined at the end of each month.

(B) Isomerization unit Heater H-1, shall not exceed:

(i) 0.275 lbs/MMBtu; and

(ii) 1,342.03 x 10³ MMBtu in a twelve (12) consecutive month period with compliance determined at the end of each month.

(i) 0.275 lbs/MMBtu; and

(ii) 1,861.5 x 10³ MMBtu in a twelve (12) consecutive month period with compliance determined at the end of each month.

(D) No. 4 Ultraformer Heaters F-1 through F-7 and F-8A and F-8B, shall not exceed 566.1 tons in a twelve (12) consecutive month period with compliance determined at the end of each month.

(E) Cat Feed Hydrotreating Units, Heaters F-801A, and F-801B, shall not exceed 33.03 tons in a twelve (12) consecutive month period with compliance determined at the end of each month.

(i) Cleveland-Cliffs Burns Harbor, LLC, whose source ID is 127-00001, in Porter County shall comply with the following emissions limits:

(1) Coke Oven Battery No. 1 shall:

(A) operate using only blast furnace gas, coke oven gas, or a blend of blast furnace gas and coke oven gas as fuel excluding periods of hot idling; and

(B) be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(2) Coke Oven Battery No. 2 shall:

(A) operate using only coke oven gas as fuel excluding periods of hot idling;

(B) operate using staged combustion to reduce peak flame temperature; and

(C) be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(3) The Recycling Plant shall be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(4) Blast Furnace C and D shall comply with the following:

(A) Each group of blast furnace stoves shall:

(i) receive ninety percent (90%) or more of its total gas volume from blast furnace gas as fuel on a rolling thirty (30) operating-day basis; and

(ii) be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(B) Each casthouse and flare shall operate in accordance with manufacturer's specifications and good operating practices for the control of NOx emissions.

(5) Basic Oxygen Furnace vessels 1, 2, and 3 shall operate in accordance with good operating practices for the control of NOx emissions.

(6) A carbon monoxide flare shall be operated and maintained on BOF vessel 3 in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(7) The 160-inch Plate Mill Slab Reheat Furnaces (SRF) No. 1 and No. 2 - Continuous Pusher, shall:

(A) operate using low-NOx burners; and

(B) be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(8) The 110-inch Plate Mill shall comply with the following:

(A) Slab Reheat Furnaces - Continuous Walking Beam No. 1 and No. 2 shall operate using low-NOx burners; and

(B) be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(C) Not later than thirty (30) days after the effective date of this rule, the owner or operator of the source shall apply to remove the Normalizing Furnace from the source.

(9) The Cold Sheet Mill and the Continuous Heat Treat Line shall:

(A) operate using only natural gas as fuel;

(B) have tune ups of burners conducted as required by 40 CFR 63.7540(a)(10)*; and

(C) be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(10) The Power Station, including boilers 7 through 12, shall comply with the following:

(A) NOx emissions from each boiler shall not exceed 0.17 lbs/MMBtu on a rolling thirty (30) operating-day basis.

(B) Tune ups shall be conducted in accordance with 40 CFR 63, subpart DDDDD* and paragraph 10-7-3(c) of this rule.

(C) The unit shall be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(j) United States Steel Corporation Midwest, whose source ID is 127-00009, in Porter County shall comply with the following emissions limits:

(1) The Continuous Annealing Line annealing furnace and the No. 2 Galvanizing Line annealing furnace section shall be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions.

(2) Total NOx emissions from the No. 2 galvanizing line furnace stack S-20 shall not exceed 0.512 lbs/MMBtu.

(3) Total NOx emissions from the No. 2 galvanizing line furnace stack S-20a shall not exceed 0.388 lbs/MMBtu.

(k) NLMK Indiana, whose source ID is 127-00036, in Porter County shall comply with the following emissions limits:

(1) The Melt Shop twin shell electric arc furnace with a direct shell evacuation control system shall:

(A) be operated and maintained in accordance with the manufacturer's specifications and good combustion practices for the control of NOx emissions;

(B) operate using oxy-fuel burners to provide supplemental energy during the electric arc furnace process; and

(i) the electric arc furnace;

(ii) ladle metallurgical furnace;

(iii) continuous caster; and

(iv) natural gas combustion units

shall not exceed forty-five hundredths (0.45) pound per ton of steel produced and 67.95 pounds per hour through the melt shop stack (S-2).

(2) The Hot Strip Mill Operations Reheat Furnace Unit 10 shall comply with the following:

(A) Only natural gas shall be burned in the slab reheat furnace and the heat input shall not exceed 264.6 MMBtu per hour.

(B) The NOx emissions from Slab Reheat Furnace shall be controlled by NOx control technology consisting of:

(i) low-NOx burners; and

(ii) a Selective Catalytic Reduction Unit.

(i) 0.077 lb/MMBtu of natural gas burned; and

(ii) 18.88 pounds per hour on a three (3) operating hour average basis.

(D) The Reheat Furnace shall operate in a manner consistent with good air pollution control and work practices to minimize emissions during startup and shutdown.

*These documents are incorporated by reference. Copies may be obtained from the Government Publishing Office, www.gpo.gov, or are available for review at the Indiana Department of Environmental Management, Office of Legal Counsel, Indiana Government Center North, 100 North Senate Avenue, Thirteenth Floor, Indianapolis, IN 46204.

(Air Pollution Control Division; 326 IAC 10-7-8; filed Oct 27, 2025, 10:54 a.m.: 20251126-IR-326250204FRA)