NR 440.50(2)(L)(L) “Natural gas” means a naturally occurring fluid mixture of hydrocarbons, such as methane, ethane, or propane, produced in geological formations beneath the earth’s surface that maintains a gaseous state at standard atmospheric temperature and pressure under ordinary conditions. Natural gas contains 20.0 grains or less of total sulfur per 100 standard cubic feet. Equivalents of this in other units are as follows: 0.068 weight percent total sulfur, 680 parts per million by weight (ppmw) total sulfur, and 338 parts per million by volume (ppmv) at 20 degrees Celsius total sulfur. Additionally, natural gas shall either be composed of at least 70% methane by volume or have a gross calorific value between 950 and 1100 Btu per standard cubic foot. Natural gas does not include the following gaseous fuels: landfill gas, digester gas, refinery gas, sour gas, blast furnace gas, coal-derived gas, producer gas, coke oven gas, or any gaseous fuel produced in a process which might result in highly variable sulfur content or heating value. NR 440.50(2)(m)(m) “Offshore platform gas turbines” means any stationary gas turbine located on a platform in an ocean. NR 440.50(2)(n)(n) “Peak load” means 100% of the manufacturer’s design capacity of the gas turbine at ISO standard day conditions. NR 440.50(2)(p)(p) “Regenerative cycle gas turbine” means any stationary gas turbine that recovers heat from the gas turbine exhaust gases to preheat the inlet combustion air to the gas turbine. NR 440.50(2)(q)(q) “Simple cycle gas turbine” means any stationary gas turbine which does not recover heat from the gas turbine exhaust gases to preheat the inlet combustion air to the gas turbine, or which does not recover heat from the gas turbine exhaust gases to heat water or generate steam. NR 440.50(2)(r)(r) “Stationary gas turbine” means any simple cycle gas turbine, regenerative cycle gas turbine or any gas turbine portion of a combined cycle steam/electric generating system that is not self-propelled. It may, however, be mounted on a vehicle for portability. NR 440.50(2)(s)(s) “Turbines employed in oil or gas production or oil or gas transportation” means any stationary gas turbine used to provide power to extract crude oil or natural gas, or both, from the earth or to move crude oil or natural gas, or both, or products refined from these substances through pipelines. NR 440.50(2)(t)(t) “Unit operating day” means a 24-hour period between 12:00 midnight and the following midnight during which any fuel is combusted at any time in the unit. It is not necessary for fuel to be combusted continuously for the entire 24-hour period. NR 440.50(2)(u)(u) “Unit operating hour” means a clock hour during which any fuel is combusted in the affected unit. If the unit combusts fuel for the entire clock hour, it is considered to be a full unit operating hour. If the unit combusts fuel for only part of the clock hour, it is considered to be a partial unit operating hour. NR 440.50(3)(a)(a) On and after the date on which the performance test required by s. NR 440.08 is completed, every owner or operator subject to the provisions of this section, as specified in pars. (b), (c) and (d), shall comply with one of the following, except as provided in pars. (e) through (L). NR 440.50(3)(a)1.1. No owner or operator subject to the provisions of this section may cause to be discharged into the atmosphere from any stationary gas turbine, any gases which contain nitrogen oxides in excess of: where:
STD is the allowable ISO corrected, if required as given in sub. (6) (c), NOx emissions (percent by volume at 15% oxygen and on a dry basis)
Y is the manufacturer’s rated heat rate at manufacturer’s rated load (kilojoules per watt hour), or actual measured heat rate based on lower heating value of fuel as measured at actual peak load for the facility (the value of Y may not exceed 14.4 kilojoules per watt hour)
F is the NOx emission allowance for fuel-bound nitrogen as defined in subd. 4.
NR 440.50(3)(a)2.2. No owner or operator subject to the provisions of this section may cause to be discharged into the atmosphere from any stationary gas turbine, any gases which contain nitrogen oxides in excess of: where:
STD is the allowable ISO corrected, if required as given in sub. (6) (c), NOx emissions (percent by volume at 15% oxygen and on a dry basis)
Y is the manufacturer’s rated heat rate at manufacturer’s rated peak load (kilojoules per watt hour), or actual measured heat rate based on lower heating value of fuel as measured at actual peak load for the facility (the value of Y may not exceed 14.4 kilojoules per watt hour)
F is the NOx emission allowance for fuel-bound nitrogen as defined in subd. 4.
NR 440.50(3)(a)3.3. The use of F in subds. 1. and 2. is optional. That is, the owner or operator may choose to apply an NOx allowance for fuel-bound nitrogen and determine the appropriate F-value in accordance with subd. 4. or may accept an F-value of zero. NR 440.50(3)(a)4.4. If the owner or operator elects to apply an NOx emission allowance for fuel-bound nitrogen, F shall be defined according to the nitrogen content of the fuel during the most recent performance test required under s. NR 440.08 as follows: where N is the nitrogen content of the fuel (percent by weight), or manufacturers may develop and submit to the department custom fuel-bound nitrogen allowances for each gas turbine model they manufacture. These fuel-bound nitrogen allowances shall be substantiated with data and must be approved for use by the administrator before the initial performance test required by s. NR 440.08. NR 440.50 NoteNote: The administrator will publish notices of approval of custom fuel-bound nitrogen allowances in the federal register.
NR 440.50(3)(b)(b) Electric utility stationary gas turbines with a heat input at peak load greater than 107.2 gigajoules per hour (100 million Btu/hour) based on the lower heating value of the fuel fired except as provided in par. (d) shall comply with the provisions of par. (a) 1. NR 440.50(3)(c)(c) Stationary gas turbines with a heat input at peak load equal to or greater than 10.7 gigajoules per hour (10 million Btu/hour) but less than or equal to 107.2 gigajoules per hour (100 million Btu/hour) based on the lower heating value of the fuel fired shall comply with the provisions of par. (a) 2. NR 440.50(3)(d)(d) Electric utility stationary gas turbines with a manufacturer’s rated base load at ISO conditions of 30 megawatts or less except as provided in par. (b) shall comply with the provisions of par. (a) 2. NR 440.50(3)(e)(e) Stationary gas turbines with a heat input at peak load equal to or greater than 10.7 gigajoules per hour (10 million Btu/hour) but less than or equal to 107.2 gigajoules per hour (100 million Btu/hour) based on the lower heating value of the fuel fired and that have commenced construction prior to October 3, 1982 are exempt from par. (a). NR 440.50(3)(f)(f) Stationary gas turbines using water or steam injection for control of NOx emissions are exempt from par. (a) when ice fog is deemed a traffic hazard by the owner or operator of the gas turbine. NR 440.50(3)(g)(g) Emergency gas turbines, military gas turbines for use in other than a garrison facility, military gas turbines installed for use as military training facilities and fire fighting gas turbines are exempt from par. (a). NR 440.50(3)(h)(h) Stationary gas turbines engaged by manufacturers in research and development of equipment for both gas turbine emission control techniques and gas turbine efficiency improvements may be exempted from par. (a) on a case-by-case basis by the department. NR 440.50(3)(i)(i) Exemptions from the requirements of par. (a) may be granted on a case-by-case basis as determined by the department in specific geographical areas where mandatory water restrictions are required by governmental agencies because of drought conditions. These exemptions may be allowed only while the mandatory water restrictions are in effect. NR 440.50(3)(j)(j) Stationary gas turbines with a heat input at peak load greater than 107.2 gigajoules per hour that commenced construction, modification or reconstruction between the dates of October 3, 1977, and January 27, 1982, and were required in the September 10, 1979 federal register (44 FR 52792) to comply with 40 CFR 60.332 (a) (1), except electric utility stationary gas turbines, are exempt from par. (a). NR 440.50(3)(k)(k) Stationary gas turbines with a heat input greater than or equal to 10.7 gigajoules per hour (10 million Btu/hour) when fired with natural gas are exempt from par. (a) 2. when being fired with an emergency fuel. NR 440.50(3)(L)(L) Regenerative cycle gas turbines with a heat input less than or equal to 107.2 gigajoules per hour (100 million Btu/hour) are exempt from par. (a). NR 440.50(4)(4) Standard for sulfur dioxide. On and after the date on which the performance test required to be conducted by s. NR 440.08 is completed, every owner or operator subject to the provisions of this section shall comply with one or the other of the following conditions: NR 440.50(4)(a)(a) No owner or operator subject to the provisions of this section may cause to be discharged into the atmosphere from any stationary gas turbine any gases which contain sulfur dioxide in excess of 0.015% by volume at 15% oxygen and on a dry basis. NR 440.50(4)(b)(b) No owner or operator subject to the provisions of this section may burn in any stationary gas turbine any fuel which contains sulfur in excess of 0.8% by weight (8000 ppmw). NR 440.50(5)(a)(a) Except as provided in par. (b), the owner or operator of any stationary gas turbine subject to the provisions of this section and using water or steam injection to control NOx emissions shall install, calibrate, maintain and operate a continuous monitoring system to monitor and record the fuel consumption and ratio of water or steam to fuel being fired in the turbine. NR 440.50(5)(b)(b) The owner or operator of any stationary gas turbine that commenced construction, reconstruction or modification after October 3, 1977, but before July 8, 2004, and which uses water or steam injection to control NOx emissions may, as an alternative to operating the continuous monitoring system described in par. (a), install, certify, maintain, operate and quality-assure a continuous emission monitoring system (CEMS) consisting of NOx and O2 monitors. As an alternative, a CO2 monitor may be used to adjust the measured NOx concentrations to 15% O2 by either converting the CO2 hourly averages to equivalent O2 concentrations using Equation F-14a or F-14b in Appendix F of 40 CFR part 75, incorporated by reference in s. NR 440.17 (1), and making the adjustments to 15% O2, or by using the CO2 readings directly to make the adjustments, as described in Method 20. If the option to use a CEMS is chosen, the CEMS shall be installed, certified, maintained and operated as follows: NR 440.50(5)(b)1.1. Each CEMS shall be installed and certified according to PS 2 and 3 (for diluent) of 40 CFR part 60, Appendix B, incorporated by reference in s. NR 440.17 (1), except the 7-day calibration drift is based on unit operating days, not calendar days. Appendix F, Procedure 1 is not required. The relative accuracy test audit (RATA) of the NOx and diluent monitors may be performed individually or on a combined basis, that is, the relative accuracy tests of the CEMS may be performed in one of the following ways: NR 440.50(5)(b)1.c.c. On a ppm basis (for NOx) and a percent CO2 basis, for a CO2 monitor that uses the procedures in Method 20 to correct the NOx data to 15% O2. NR 440.50(5)(b)2.2. As specified in s. NR 440.13 (5) (b), during each full unit operating hour, each monitor shall complete a minimum of one cycle of operation (sampling, analyzing and data recording) for each 15-minute quadrant of the hour, to validate the hour. For partial unit operating hours, at least one valid data point shall be obtained for each quadrant of the hour in which the unit operates. For unit operating hours in which required quality assurance and maintenance activities are performed on the CEMS, a minimum of 2 valid data points, one in each of 2 quadrants, are required to validate the hour. NR 440.50(5)(b)3.a.a. For each unit operating hour in which a valid hourly average, as described in subd. 2., is obtained for both NOx and diluent, the data acquisition and handling system shall calculate and record the hourly NOx emissions in the units of the applicable NOx emission standard under sub. (3) (a), that is, percent NOx by volume, dry basis, corrected to 15% O2 and International Organization for Standardization (ISO) standard conditions, if required as given in sub. (6) (c) 1. For any hour in which the hourly average O2 concentration exceeds 19.0% O2, a diluent cap value of 19.0% O2 may be used in the emission calculations. NR 440.50(5)(b)3.b.b. A worst case ISO correction factor may be calculated and applied using historical ambient data. For the purpose of this calculation, substitute the maximum humidity of ambient air (Ho), minimum ambient temperature (Ta), and minimum combustor inlet absolute pressure (Po) into the ISO correction equation. NR 440.50(5)(b)3.c.c. If the owner or operator has installed a NOx CEMS to meet the requirements of 40 CFR part 75, and is continuing to meet the ongoing requirements of 40 CFR part 75, the CEMS may be used to meet the requirements of this section, except that the missing data substitution methodology provided for at 40 CFR part 75, subpart D, is not required for purposes of identifying excess emissions. Instead, periods of missing CEMS data are to be reported as monitor downtime in the excess emissions and monitoring performance report required in s. NR 440.07 (3). NR 440.50(5)(c)(c) For any turbine that commenced construction, reconstruction or modification after October 3, 1977, but before July 8, 2004, and which does not use steam or water injection to control NOx emissions, the owner or operator may, for purposes of determining excess emissions, use a CEMS that meets the requirements of par. (b). Also, if the owner or operator has previously submitted and received EPA, department or local permitting authority approval of a petition for an alternative procedure of continuously monitoring compliance with the applicable NOx emission limit under sub. (3), that approved procedure may continue to be used. NR 440.50(5)(d)(d) The owner or operator of any new turbine constructed after July 8, 2004, and which uses water or steam injection to control NOx emissions may elect to use either the requirements in par. (a) for continuous water or steam to fuel ratio monitoring or may use a NOx CEMS installed, certified, operated, maintained and quality-assured as described in par. (b). NR 440.50(5)(e)(e) The owner or operator of any new turbine that commences construction after July 8, 2004, and which does not use water or steam injection to control NOx emissions may elect to use a NOx CEMS installed, certified, operated, maintained and quality-assured as described in par. (b). Other acceptable monitoring approaches include periodic testing approved by EPA, the department or local permitting authority or continuous parameter monitoring as described in par. (f). NR 440.50(5)(f)(f) The owner or operator of a new turbine that commences construction after July 8, 2004, which does not use water or steam injection to control NOx emissions may perform continuous parameter monitoring as follows: NR 440.50(5)(f)1.1. For a diffusion flame turbine without add-on selective catalytic reduction controls (SCR), the owner or operator shall define at least 4 parameters indicative of the unit’s NOx formation characteristics and shall monitor these parameters continuously. NR 440.50(5)(f)2.2. For any lean premix stationary combustion turbine, the owner or operator shall continuously monitor the appropriate parameters to determine whether the unit is operating in low-NOx mode. NR 440.50(5)(f)3.3. For any turbine that uses SCR to reduce NOx emissions, the owner or operator shall continuously monitor appropriate parameters to verify the proper operation of the emission controls. NR 440.50(5)(g)(g) The steam or water to fuel ratio or other parameters that are continuously monitored as described in par. (a), (d) or (f) shall be monitored during the performance test required under s. NR 440.08, to establish acceptable values and ranges. The owner or operator may supplement the performance test data with engineering analyses, design specifications, manufacturer’s recommendations and other relevant information to define the acceptable parametric ranges more precisely. The owner or operator shall develop and keep on-site a parameter monitoring plan which explains the procedures used to document proper operation of the NOx emission controls. The plan shall include the parameters monitored and the acceptable ranges of the parameters as well as the basis for designating the parameters and acceptable ranges. Any supplemental data such as engineering analyses, design specifications, manufacturer’s recommendations and other relevant information shall be included in the monitoring plan. For affected units that are also subject to 40 CFR part 75 and that use the low mass emissions methodology in 40 CFR 75.19 or the NOx emission measurement methodology in Appendix E of 40 CFR part 75, the owner or operator may meet the requirements of this paragraph by developing and keeping on-site (or at a central location for unmanned facilities) a quality-assurance plan, as described in 40 CFR 75.19 (e) (5) or in section 2.3 of Appendix E and section 1.3.6 of Appendix B of 40 CFR part 75, both incorporated by reference in s. NR 440.17 (1). NR 440.50(5)(h)(h) The owner or operator of any stationary gas turbine subject to the provisions of this section: NR 440.50(5)(h)1.1. Shall monitor the total sulfur content of the fuel being fired in the turbine, except as provided in subd. 3. The sulfur content of the fuel shall be determined using total sulfur methods described in sub. (6) (d). Alternatively, if the total sulfur content of the gaseous fuel during the most recent performance test was less than 0.4 weight percent (4000 ppmw), ASTM D4084-94, D5504-01, D6228-98, or Gas Processors Association Standard 2377-86, incorporated by reference in s. NR 440.17 (2) (a) 52., 64. and 68. and (m). respectively, which measure the major sulfur compounds may be used. NR 440.50(5)(h)2.2. Shall monitor the nitrogen content of the fuel combusted in the turbine, if the owner or operator claims an allowance for fuel bound nitrogen, that is, if an F-value greater than zero is being or will be used by the owner or operator to calculate STD in sub. (3). The nitrogen content of the fuel shall be determined using methods described in sub. (6) (c) 9. or an approved alternative. NR 440.50(5)(h)3.3. Notwithstanding the provisions of subd. 1., the owner or operator may elect not to monitor the total sulfur content of the gaseous fuel combusted in the turbine, if the gaseous fuel is demonstrated to meet the definition of natural gas in sub. (2) (L), regardless of whether an existing custom schedule approved by the department for this section requires the monitoring. The owner or operator shall use one of the following sources of information to make the required demonstration: NR 440.50(5)(h)3.a.a. The gas quality characteristics in a current, valid purchase contract, tariff sheet or transportation contract for the gaseous fuel, specifying that the maximum total sulfur content of the fuel is 20.0 grains/100 scf or less. NR 440.50(5)(h)3.b.b. Representative fuel sampling data which show that the sulfur content of the gaseous fuel does not exceed 20 grains/100 scf. At a minimum, the amount of fuel sampling data specified in section 2.3.1.4 or 2.3.2.4 of Appendix D to 40 CFR part 75, incorporated by reference in s. NR 440.17 (1), is required. NR 440.50(5)(h)4.4. For any turbine that commenced construction, reconstruction or modification after October 3, 1977, but before July 8, 2004, and for which a custom fuel monitoring schedule has previously been approved, the owner or operator may, without submitting a special petition to the department, continue monitoring on this schedule. NR 440.50(5)(i)(i) The frequency of determining the sulfur and nitrogen content of the fuel shall be as follows: NR 440.50(5)(i)1.1. ’Fuel oil.’ For fuel oil, use one of the total sulfur sampling options and the associated sampling frequency described in sections 2.2.3, 2.2.4.1, 2.2.4.2, and 2.2.4.3 of Appendix D to 40 CFR part 75, incorporated by reference in s. NR 440.17 (1), that is, flow proportional sampling, daily sampling, sampling from the unit’s storage tank after each addition of fuel to the tank, or sampling each delivery prior to combining it with fuel oil already in the intended storage tank. If an emission allowance is being claimed for fuel-bound nitrogen, the nitrogen content of the oil shall be determined and recorded once per unit operating day. NR 440.50(5)(i)2.2. ’Gaseous fuel.’ Any applicable nitrogen content value of the gaseous fuel shall be determined and recorded once per unit operating day. For owners and operators that elect not to demonstrate sulfur content using options in par. (h) 3., and for which the fuel is supplied without intermediate bulk storage, the sulfur content value of the gaseous fuel shall be determined and recorded once per unit operating day. NR 440.50(5)(i)3.3. ’Custom schedules.’ Notwithstanding the requirements of subd. 2., operators or fuel vendors may develop custom schedules for determination of the total sulfur content of gaseous fuels, based on the design and operation of the affected facility and the characteristics of the fuel supply. Except as provided in subd. 3. a. and b., custom schedules shall be substantiated with data and shall be approved by the department before they can be used to comply with the standard in sub. (4). NR 440.50(5)(i)3.a.a. The 2 custom sulfur monitoring schedules set forth in subd. 3 .a. 1) to 4) and in subd. 3. b. are acceptable, without prior department approval: 1) The owner or operator shall obtain daily total sulfur content measurements for 30 consecutive unit operating days, using the applicable methods specified in this section. Based on the results of the 30 daily samples, the required frequency for subsequent monitoring of the fuel’s total sulfur content shall be as specified in subd. 3. a. 2), 3) or 4), as applicable.
2) If none of the 30 daily measurements of the fuel’s total sulfur content exceeds 0.4 weight percent (4000 ppmw), subsequent sulfur content monitoring may be performed at 12-month intervals. If any of the samples taken at 12-month intervals has a total sulfur content between 0.4 and 0.8 weight percent (4000 and 8000 ppmw), follow the procedures in subd. 3. a. 3). If any measurement exceeds 0.8 weight percent (8000 ppmw), follow the procedures in subd. 3. a. 4).
3) If at least one of the 30 daily measurements of the fuel’s total sulfur content is between 0.4 and 0.8 weight percent (4000 and 8000 ppmw), but none exceeds 0.8 weight percent (8000 ppmw), then:
a) Collect and analyze a sample every 30 days for 3 months. If any sulfur content measurement exceeds 0.8 weight percent (8000 ppmw), follow the procedures in subd. 3. a. 4). Otherwise, follow the procedures in subd. 3. a. 3) b).
b) Begin monitoring at 6-month intervals for 12 months. If any sulfur content measurement exceeds 0.8 weight percent (8000 ppmw), follow the procedures in subd. 3. a. 4). Otherwise, follow the procedures in subd. 3. a. 3) c).
c) Begin monitoring at 12-month intervals. If any sulfur content measurement exceeds 0.8 weight percent (8000 ppmw), follow the procedures in subd. 3. a. 4). Otherwise, continue to monitor at this frequency.
4) If a sulfur content measurement exceeds 0.8 weight percent (8000 ppmw), immediately begin daily monitoring according to subd. 3. a. 1). Daily monitoring shall continue until 30 consecutive daily samples, each having a sulfur content no greater than 0.8 weight percent (8000 ppmw), are obtained. At that point, the applicable procedures of subd. 3. a. 2) or 3) shall be followed.
NR 440.50(5)(i)3.b.b. The owner or operator may use the data collected from the 720-hour sulfur sampling demonstration described in section 2.3.6 of Appendix D to 40 CFR part 75, incorporated by reference in s. NR 440.17 (1), to determine a custom sulfur sampling schedule, as follows: 1) If the maximum fuel sulfur content obtained from the 720 hourly samples does not exceed 20 grains/100 scf, that is, the maximum total sulfur content of natural gas as defined in sub. (2) (L), no additional monitoring of the sulfur content of the gas is required for the purposes of this section.
2) If the maximum fuel sulfur content obtained from any of the 720 hourly samples exceeds 20 grains/100 scf, but none of the sulfur content values, when converted to weight percent sulfur, exceeds 0.4 weight percent (4000 ppmw), then the minimum required sampling frequency shall be one sample at 12-month intervals.
3) If any sample result exceeds 0.4 weight percent sulfur (4000 ppmw), but none exceeds 0.8 weight percent sulfur (8000 ppmw), follow the provisions of subd. 3. a. 3).
4) If the sulfur content of any of the 720 hourly samples exceeds 0.8 weight percent (8000 ppmw), follow the provisions of subd. 3. a. 4).
NR 440.50(5)(j)(j) For each affected unit that elects to continuously monitor parameters or emissions, or to periodically determine the fuel sulfur content or fuel nitrogen content under this section, the owner or operator shall submit reports of excess emissions and monitor downtime, in accordance with s. NR 440.07 (3). Excess emissions shall be reported for all periods of unit operation, including startup, shutdown and malfunction. For the purpose of reports required under s. NR 440.07 (3), periods of excess emissions and monitor downtime that shall be reported are defined as follows: 1) An excess emission shall be any unit operating hour for which the average steam or water to fuel ratio, as measured by the continuous monitoring system, falls below the acceptable steam or water to fuel ratio needed to demonstrate compliance with sub. (3), as established during the performance test required in s. NR 440.08. Any unit operating hour in which no water or steam is injected into the turbine shall also be considered an excess emission. 2) A period of monitor downtime shall be any unit operating hour in which water or steam is injected into the turbine, but the essential parametric data needed to determine the steam or water to fuel ratio are unavailable or invalid.
