Chapter NR 428

NR 428.21(2) (2) Low operating unit. An emissions unit described in s. NR 428.20 is exempt from the emission limitations of s. NR 428.22 if, during each ozone season, the emissions unit’s utilization based on actual measured heat input or output is less than the utilization threshold for the source category according to the following equation:

UUi < (Category capacity ) x (3,672 hours / Ozone Season ) x Capacity Factor     Equation 1

where:

UUi is the unit’s actual fuel consumption or output in measurement units consistent with the calculated utilization threshold for the source category in s. NR 428.22

Category capacity is the lower value in the range of unit capacity or design output used to describe the unit’s source category i in s. NR 428.22

Capacity factor is 0.20 for all source categories in s. NR 428.22

NR 428.21(2m) (2m) Reciprocating engines. Any reciprocating engine that is certified to meet the applicable federal non-road engine emission standards specified in this subsection is exempt from the emission limitations of s. NR 428.22 (1) (i):

NR 428.21(2m)(a) (a) A reciprocating compression ignition engine that is certified as meeting Tier 1 requirements as specified in 40 CFR part 89, if one of the following applies:

NR 428.21(2m)(a)1. 1. The engine has a maximum design power output of less than 2,000 horsepower.

NR 428.21(2m)(a)2. 2. The engine has a maximum design power output equal to or greater than 2,000 horsepower and has a total utilization during each ozone season of less than 1.5 million horsepower-hours, based on actual measured output.

NR 428.21(2m)(b) (b) A reciprocating compression ignition engine that is certified as meeting the Tier 2 standard, as specified in 40 CFR part 89, or a reciprocating compression ignition engine that is certified as meeting the requirements of a more stringent Tier standard, as specified in 40 CFR part 89 or 1039.

NR 428.21(2m)(c) (c) A reciprocating spark ignition engine that is certified as meeting the Tier 1 standard or a reciprocating spark ignition engine that is certified as meeting a more stringent Tier standard, as specified in 40 CFR part 1048.

NR 428.21(3) (3) Other regulated unit. An emissions unit is exempt from the emission limitations under s. NR 428.22 if it meets all of the following conditions:

NR 428.21(3)(a) (a) The emissions unit does not emit more than 75 tons of NOx per year due to a physical operating constraint or a federally enforceable condition in an air permit.

NR 428.21(3)(b) (b) The emissions unit is located in a facility subject to the applicability thresholds specified under s. NR 428.20 (1) (a) 1., 2. a., or 3. a.

NR 428.21(3)(c) (c) The emissions unit is subject to and meeting an emission limitation under s. NR 428.04 (2) or 428.05 (3).

NR 428.21(3)(d) (d) The emissions unit was constructed prior to August 1, 2007.

NR 428.21 History History: CR 07-016: cr. Register July 2007 No. 619, eff. 8-1-07; CR 21-022: am. (3) (intro.), (a), (b), cr. (3) (c) Register February 2022 No. 794, eff. 3-1-22; correction in (3) (intro.) made under s. 35.17, Stats., Register February 2022 No. 794; CR 23-017: cr. (3) (d) Register March 2024 No. 819, eff. 4-1-24.

NR 428.22 NR 428.22 Emission limitation requirements.

NR 428.22(1) (1) Emission limits. Except as provided under subs. (2) and (3), on or after May 1, 2009, no person may cause, allow, or permit NOX to be emitted in excess of the following emission limitations on a 30-day rolling average basis:

NR 428.22(1)(a) (a) Boilers.

NR 428.22(1)(a)1. 1. For a solid fuel-fired boiler with a maximum heat input capacity equal to or greater than 1,000 mmBtu per hour, one of the following, as applicable:

NR 428.22(1)(a)1.a. a. If tangential, wall, cyclone or fluidized bed-fired, 0.10 pound per mmBtu of heat input.

NR 428.22(1)(a)1.b. b. If arch-fired, 0.18 pound per mmBtu of heat input.

NR 428.22(1)(a)2. 2. For a solid fuel-fired boiler with a maximum heat input capacity equal to or greater than 500 mmBtu per hour and less than 1,000 mmBtu per hour, one of the following, as applicable:

NR 428.22(1)(a)2.a. a. If tangential-fired, 0.15 pound per mmBtu of heat input.

NR 428.22(1)(a)2.b. b. If wall-fired with a heat release rate equal to or greater than 17,000 Btu per cubic feet per hour, 0.17 pound per mmBtu of heat input.

NR 428.22(1)(a)2.c. c. If wall-fired with a heat release rate less than 17,000 Btu per cubic feet per hour, 0.15 pound per mmBtu of heat input.

NR 428.22(1)(a)2.d. d. If cyclone-fired, 0.15 pound per mmBtu of heat input.

NR 428.22(1)(a)2.e. e. If arch-fired, 0.18 pound per mmBtu of heat input.

NR 428.22(1)(a)2.f. f. If fluidized bed-fired, 0.10 pound per mmBtu of heat input.

NR 428.22(1)(a)3. 3. For a solid fuel-fired boiler with a maximum heat input capacity equal to or greater than 250 mmBtu per hour and less than 500 mmBtu per hour, one of the following, as applicable:

NR 428.22(1)(a)3.a. a. If tangential-fired, 0.15 pound per mmBtu of heat input.

NR 428.22(1)(a)3.b. b. If wall-fired with a heat release rate equal to or greater than 17,000 Btu per cubic feet per hour, 0.17 pound per mmBtu of heat input.

NR 428.22(1)(a)3.c. c. If wall-fired with a heat release rate less than 17,000 Btu per cubic feet per hour, 0.15 pound per mmBtu of heat input.

NR 428.22(1)(a)3.d. d. If cyclone-fired, 0.15 pound per mmBtu of heat input.

NR 428.22(1)(a)3.f. f. If arch-fired, 0.18 pound per mmBtu of heat input.

NR 428.22(1)(a)3.g. g. If fluidized bed-fired, 0.10 pound per mmBtu of heat input.

NR 428.22(1)(a)3.h. h. If stoker-fired, 0.20 pound per mmBtu of heat input.

NR 428.22(1)(a)4. 4. For a solid fuel-fired boiler with a maximum heat input capacity equal to or greater than 50 mmBtu per hour and less than 250 mmBtu per hour, one of the following, as applicable:

NR 428.22(1)(a)4.a. a. If tangential-fired, 0.15 pound per mmBtu of heat input.

NR 428.22(1)(a)4.b. b. If wall-fired with a heat release rate equal to or greater than 17,000 Btu per cubic feet per hour, 0.17 pound per mmBtu of heat input.

NR 428.22(1)(a)4.c. c. If wall-fired with a heat release rate less than 17,000 Btu per cubic feet per hour, 0.15 pound per mmBtu of heat input.

NR 428.22(1)(a)4.d. d. If cyclone-fired, 0.15 pound per mmBtu of heat input.

NR 428.22(1)(a)4.e. e. If fluidized bed-fired, 0.10 pound per mmBtu of heat input.

NR 428.22(1)(a)4.f. f. If stoker-fired, 0.25 pound per mmBtu of heat input.

NR 428.22(1)(a)5. 5. For a gaseous fuel-fired boiler with a maximum heat input capacity equal to or greater than 100 mmBtu per hour, 0.08 pound per mmBtu of heat input.

NR 428.22(1)(a)6. 6. For a distillate fuel oil-fired boiler with a maximum heat input capacity equal to or greater than 100 mmBtu per hour, 0.10 pound per mmBtu of heat input.

NR 428.22(1)(a)7. 7. For a residual fuel oil-fired boiler with a maximum heat input capacity equal to or greater than 65 mmBtu per hour, 0.15 pound per mmBtu of heat input.

NR 428.22(1)(b) (b) Lime kilns. For a lime kiln with a maximum heat input capacity equal to or greater than 50 mmBtu per hour, one of the following as applicable:

NR 428.22(1)(b)1. 1. For a gaseous fuel-fired unit, 0.10 pound per mmBtu of heat input.

NR 428.22(1)(b)2. 2. For a distillate oil-fired unit, 0.12 pound per mmBtu of heat input.

NR 428.22(1)(b)3. 3. For a residual oil-fired unit, 0.15 pound per mmBtu of heat input.

NR 428.22(1)(b)4. 4. For a coal-fired unit, 0.60 pound per mmBtu of heat input.

NR 428.22(1)(b)5. 5. For a coke-fired unit, 0.70 pound per mmBtu of heat input.

NR 428.22(1)(c) (c) Reheat, annealing or galvanizing furnaces. For a reheat, annealing or galvanizing furnace with a maximum heat input capacity equal to or greater than 75 mmBtu per hour, 0.08 pounds per million Btu of heat input.

NR 428.22(1)(d) (d) Glass furnaces.

NR 428.22(1)(d)1. 1. For a glass manufacturing furnace with a maximum heat input capacity equal to or greater than 50 mmBtu per hour, 2.0 pounds per ton of produced glass, except as provided in subd. 2.

NR 428.22(1)(d)2. 2. When, on a daily basis, a glass furnace is operated at less than 25% of glass production capacity, the owner or operator shall operate the furnace according to the combustion optimization requirements of s. NR 439.096 and shall meet the monitoring requirements of s. NR 428.05 (2) (e).

NR 428.22(1)(e) (e) Asphalt plants. For an asphalt plant with a maximum heat input capacity equal to or greater than 65 mmBtu per hour, one of the following as applicable:

NR 428.22(1)(e)1. 1. For a gaseous fuel-fired unit, 0.15 pound per million Btu of heat input.

NR 428.22(1)(e)2. 2. For a distillate fuel oil-fired unit, 0.20 pound per million Btu of heat input.

NR 428.22(1)(e)3. 3. For a residual fuel oil-fired or waste oil-fired unit, 0.27 pound per million Btu of heat input.

NR 428.22(1)(f) (f) Process heating. For a process heater, dryer, oven or other process heating device, one of the following as applicable:

NR 428.22(1)(f)1. 1. For a gaseous fuel-fired unit with a maximum heat input capacity equal to or greater than 100 mmBtu per hour, 0.10 pound per mmBtu of heat input.

NR 428.22(1)(f)2. 2. For a distillate oil-fired unit with a maximum heat input capacity equal to or greater than 100 mmBtu per hour, 0.12 pound per mmBtu of heat input.

NR 428.22(1)(f)3. 3. For a residual oil-fired unit with a maximum heat input capacity equal to or greater than 65 mmBtu per hour, 0.18 pound per mmBtu of heat input.

NR 428.22(1)(g) (g) Simple cycle combustion turbines. For a simple cycle combustion turbine, one of the following exhaust outlet concentrations, corrected to 15% O2 and at ambient temperatures greater than 0oF, as applicable:

NR 428.22(1)(g)1. 1. For a unit with a maximum design power output equal to or greater than 50 megawatts, one of the following, as applicable:

NR 428.22(1)(g)1.a. a. If natural gas-fired, 25 parts per million dry volume.

NR 428.22(1)(g)1.b. b. If distillate oil fuel-fired, 65 parts per million dry volume.

NR 428.22(1)(g)1.c. c. If biologically derived gaseous fuel-fired, 35 parts per million dry volume.

NR 428.22(1)(g)2. 2. For a unit with a maximum design power output equal to or greater than 25 megawatts and less than 50 megawatts, one of the following as applicable:

NR 428.22(1)(g)2.a. a. If natural gas-fired, 42 parts per million dry volume.

NR 428.22(1)(g)2.b. b. If distillate oil fuel-fired, 96 parts per million dry volume.

NR 428.22(1)(g)2.c. c. If biologically derived gaseous fuel-fired, 35 parts per million dry volume.

NR 428.22(1)(h) (h) Combined cycle combustion turbines. For a combined cycle combustion turbine, one of the following exhaust outlet concentrations, corrected to 15% O2 and at ambient temperatures greater than 0oF, as applicable:

NR 428.22(1)(h)1. 1. For a natural gas-fired unit with a maximum design power output equal to or greater than 25 megawatts, 9 parts per million dry volume.

NR 428.22(1)(h)2. 2. For a natural gas-fired unit with a maximum design power output equal to or greater than 10 megawatts and less than 25 megawatts, 42 parts per million dry volume.

NR 428.22(1)(h)3. 3. For a distillate oil fuel-fired unit with a maximum design power output equal to or greater than 10 megawatts, 42 parts per million dry volume.

NR 428.22(1)(h)4. 4. For a biologically derived gaseous fuel-fired unit with a maximum design power output equal to or greater than 10 megawatts, 35 parts per million dry volume.

NR 428.22(1)(i) (i) Reciprocating engines. For a reciprocating engine with a maximum design power output equal to or greater than 500 horsepower, one of the following as applicable:

NR 428.22(1)(i)1. 1. For a rich-burn spark ignition unit, 3.0 grams per brake horsepower-hour.

NR 428.22(1)(i)2. 2. For a lean-burn spark ignition unit, 3.0 grams per brake horsepower-hour.

NR 428.22(1)(i)3. 3. For a diesel fuel-fired compression unit, 3.0 grams per brake horsepower-hour.

NR 428.22(1)(i)4. 4. For a dual fuel-fired compression unit, 3.0 grams per brake horsepower-hour.

NR 428.22(2) (2) Electric utility boiler compliance schedule. The owner or operator of an electric utility boiler shall demonstrate compliance with the following interim NOx emission limitations, as applicable, on a 30-day rolling average by May 1, 2009 and with the emission limitations in sub. (1) (a) on and after May 1, 2013:

NR 428.22(2)(a) (a) For a solid fuel-fired boiler with a maximum heat input capacity equal to or greater than 1,000 mmBtu per hour, one of the following, as applicable:

NR 428.22(2)(a)1. 1. If tangential, wall, cyclone or fluidized bed-fired, 0.15 pound per mmBtu of heat input.