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: -
See PDF for diagram 
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: -
See PDF for diagram
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 NO
x 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 NO
x 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:
-
See PDF for table
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 Note
Note:
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 NO
x 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 NO
x 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 NO
x 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 NO
x and O
2 monitors. As an alternative, a CO
2 monitor may be used to adjust the measured NO
x concentrations to 15% O
2 by either converting the CO
2 hourly averages to equivalent O
2 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% O
2, or by using the CO
2 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 NO
x 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 NO
x) and a percent CO
2 basis, for a CO
2 monitor that uses the procedures in Method 20 to correct the NO
x data to 15% O
2.
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 NO
x and diluent, the data acquisition and handling system shall calculate and record the hourly NO
x emissions in the units of the applicable NO
x emission standard under
sub. (3) (a), that is, percent NO
x by volume, dry basis, corrected to 15% O
2 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 O
2 concentration exceeds 19.0% O
2, a diluent cap value of 19.0% O
2 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 (H
o), minimum ambient temperature (T
a), and minimum combustor inlet absolute pressure (P
o) into the ISO correction equation.
NR 440.50(5)(b)3.c.
c. If the owner or operator has installed a NO
x 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 NO
x 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 NO
x 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 NO
x emissions may elect to use either the requirements in
par. (a) for continuous water or steam to fuel ratio monitoring or may use a NO
x 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 NO
x emissions may elect to use a NO
x 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 NO
x 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 NO
x 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-NO
x mode.
NR 440.50(5)(f)3.
3. For any turbine that uses SCR to reduce NO
x emissions, the owner or operator shall continuously monitor appropriate parameters to verify the proper operation of the emission controls.
NR 440.50(5)(f)4.
4. For affected units that are also regulated under
40 CFR part 75, if the owner or operator elects to monitor the NO
x emission rate using the methodology in Appendix
E of
40 CFR part 75, incorporated by reference in
s. NR 440.17 (1), or the low mass emissions methodology in
40 CFR 75.19, the requirements of this paragraph may be met by performing the parametric monitoring described in section 2.3 of Appendix
E of
40 CFR part 75 or in
40 CFR 75.19 (c) (1) (iv) (H).
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 NO
x 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 NO
x 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.
3) Each report shall include the average steam or water to fuel ratio, average fuel consumption, ambient conditions (temperature, pressure and humidity), gas turbine load, and, if applicable, the nitrogen content of the fuel during each excess emission. You do not have to report ambient conditions if you opt to use the worst case ISO correction factor as specified in par. (b) 3. b., or if you are not using the ISO correction equation under the provisions of sub. (6) (c) 1.
NR 440.50(5)(j)1.b.
b. If the owner or operator elects to take an emission allowance for fuel bound nitrogen, then excess emissions and periods of monitor downtime are as described in
subd. 1. b. 1) and 2).
1) An excess emission shall be the period of time during which the fuel-bound nitrogen (N) is greater than the value measured during the performance test required in
s. NR 440.08 and used to determine the allowance. The excess emission begins on the date and hour of the sample which shows that N is greater than the performance test value, and ends with the date and hour of a subsequent sample which shows a fuel nitrogen content less than or equal to the performance test value.
2) A period of monitor downtime begins when a required sample is not taken by its due date. A period of monitor downtime also begins on the date and hour that a required sample is taken, if invalid results are obtained. The period of monitor downtime ends on the date and hour of the next valid sample.
1) An hour of excess emissions shall be any unit operating hour in which the 4-hour rolling average NOx concentration exceeds the applicable emission limit in sub. (3) (a) 1. or 2. For the purposes of this section, a “4-hour rolling average NO
x concentration" is the arithmetic average of the average NOx concentration measured by the CEMS for a given hour (corrected to 15% O2 and, if required under sub. (6) (c) 1., to ISO standard conditions) and the 3 unit operating hour average NOx concentrations immediately preceding that unit operating hour.
2) A period of monitor downtime shall be any unit operating hour in which sufficient data are not obtained to validate the hour, for either NOx concentration or diluent, or both.
