NR 428.22(3)(3) Emissions units using secondary fuel. An emissions unit that is capable of firing secondary fuel is not subject to the requirements under sub. (1) or (2) when utilizing only a secondary fuel if any of the following apply: NR 428.22(3)(a)(a) The emissions unit heat input capacity or maximum design power output while utilizing the secondary fuel is less than the applicability thresholds under sub. (1) or (2). NR 428.22(3)(b)(b) The emissions unit burns the secondary fuel only during any of the following periods: NR 428.22(3)(b)1.1. Supply interruption or curtailment of primary fuel. The secondary fuel usage under this subsection may not exceed 500 hours within a 12 consecutive month time period unless the owner or operator obtains a fuel variance under s. NR 436.06. NR 428.22(3)(b)2.2. Periodic testing, maintenance, or operator training of the secondary fuel when the periodic testing, maintenance, or operator training does not exceed a combined total of 48 hours during any calendar year. NR 428.22(3)(c)(c) The secondary fuel constitutes less than 1 percent on an energy equivalent basis of the emissions unit’s fuel consumption within the most recent 12 consecutive month time period. NR 428.22 HistoryHistory: CR 07-016: cr. Register July 2007 No. 619, eff. 8-1-07; CR 08-103: renum. (1) (d) to be (1) (d) 1. and am., cr. (1) (d) 2., am. (2) (intro.) Register August 2009 No. 644, eff. 9-1-09; CR 23-017: am. (1) (intro.), cr. (3) Register March 2024 No. 819, eff. 4-1-24. NR 428.23NR 428.23 Demonstrating compliance with emission limitations. The owner or operator of an emissions unit shall determine the emissions unit’s NOx emissions and shall determine compliance with the emission limitations in s. NR 428.22 according to the applicable methods in this section. NR 428.23(1)(a)(a) Installation and operation. No later than April 1, 2009 or April 1 of the year an emissions unit first becomes subject to an emission limitation in s. NR 428.22, the owner or operator of the emissions unit shall do the following: NR 428.23(1)(a)1.1. Submit to the department in writing, a certification of the installation and operation of all monitoring systems or a certification of the completion of initial emission performance tests required under par. (b). NR 428.23(1)(a)2.2. Begin and continue to monitor, measure and record all data necessary to determine emissions in the measurement units of the applicable emission limitation according to the methods of this section. NR 428.23(1)(b)1.1. ‘Part 75 continuous emissions monitoring.’ The owner or operator of an electric utility boiler or combustion turbine that is subject to or becomes subject to the requirements of 40 CFR part 75 and 40 CFR part 75, Appendices A to I, incorporated by reference in s. NR 484.04 (27), shall use those monitoring methods and specifications for monitoring NOx emissions for purposes of this subsection. NR 428.23(1)(b)2.2. ‘Continuous emissions monitoring.’ Except as provided in subd. 1., the owner or operator of an emissions unit subject to an emissions limitation in s. NR 428.22 (1) (a) to (d) shall monitor NOx emissions for requirements of this subsection according to the following specifications, as applicable: NR 428.23(1)(b)2.a.a. The owner or operator shall install and operate a continuous emissions monitoring system that measures the hourly average NOx emission rate. NR 428.23(1)(b)2.b.b. The emissions monitoring system shall consist of an NOx diluent continuous emissions analyzer and, as applicable, an O2 or CO2 diluent continuous emissions analyzer to correct all emissions data and heat rate values for the emissions unit to the same moisture and diluent gas basis, as required in subd. 6. b. NR 428.23(1)(b)2.d.d. For an emissions unit subject to an NOx emission limit on a pound per million Btu basis, the emissions shall be determined using the F-factor method according to methods in Method 19 of 40 CFR part 60, Appendix A, incorporated by reference in s. NR 484.04 (16m). NR 428.23(1)(b)2.e.e. Except for an emissions unit subject to subd. 1. or an emissions unit subject to an emission limitation in s. NR 428.22 (1) (a) 1. to 4., an owner or operator of an emissions unit may measure NOx emissions for compliance determination purposes using continuous parametric monitoring methods meeting emissions monitoring specifications in 40 CFR part 75, Appendix E, incorporated by reference in s. NR 484.04 (26m) (cm). NR 428.23(1)(b)3.3. ‘Periodic emissions performance test.’ Except as provided in subd. 1., the owner or operator of an emissions unit subject to s. NR 428.22 (1) (e) to (i) shall conduct an initial performance test and a subsequent performance test every 2 years thereafter, according to the following requirements, as applicable, to determine the emissions unit’s NOx emission rate for each fuel fired in the emissions unit. A performance test is not required for a fuel used only for startup or for a fuel constituting less than 1% of the unit’s annual fuel consumption. NR 428.23(1)(b)3.a.a. The emissions performance test shall be conducted according to one of the following methods as applicable: Method 7, 7A, 7B, 7C, 7D or 7E in 40 CFR part 60, Appendix A, incorporated by reference in s. NR 484.04 (15m). NR 428.23(1)(b)3.b.b. Except for units specified in subd. 3. c., the initial emissions performance test shall include a determination of the capacity load point of the unit’s maximum NOx emissions rate based on one 30 minute test run at each capacity load point for which the unit is operated, other than for startup and shutdown, in the load ranges of 20 to 30%, 45 to 55%, 70 to 80% and 90 to 100%. NR 428.23(1)(b)3.d.d. The emissions performance test shall determine compliance based on the average of 3 60-minute test runs performed at the capacity load specified in subd. 3. b. or c. NR 428.23(1)(b)3.e.e. An additional performance test shall be conducted according to subd. 3. b. or c. within 90 days of completing an equipment modification or change in fuel which has the potential to increase the NOx emissions concentration or rate. NR 428.23(1)(b)4.4. ‘Continuous monitoring for an output based standard.’ In addition to applicable monitoring and measuring requirements under subd. 2., the owner or operator of an emissions unit subject to an output emission limitation in s. NR 428.22 (1) (d) shall do the following: NR 428.23(1)(b)4.a.a. Install, maintain and operate monitoring equipment for measuring and recording the output on an hourly basis with plus or minus 5% accuracy, in units consistent with the applicable emission limitation. NR 428.23(1)(b)4.b.b. Calculate on an hourly basis, the output based emission rate as the hourly mass of NOx emissions determined according to subd. 5. divided by the emissions unit’s total output for that hour. NR 428.23(1)(b)5.5. ‘Continuous monitoring of total heat input and mass emissions.’ The owner or operator of an emissions unit required to measure total heat input or mass NOx emissions for requirements of subd. 4., sub. (2) (c) and s. NR 428.25 (1) (b) or (c) shall perform the applicable measurements according to following: NR 428.23(1)(b)5.a.a. Except as allowed in subd. 5. d., install, calibrate, maintain and operate a volumetric flue gas flow monitoring system meeting specifications in subd. 2. c. The hourly heat input shall be determined using the F-factor and the as fired fuel heat content according to Method 19 of 40 CFR part 60, Appendix A, incorporated by reference in s. NR 484.04 (16m). NR 428.23(1)(b)5.b.b. Unless specified in Method 19 of 40 CFR part 60, Appendix A, incorporated by reference in s. NR 484.04 (16m), the heat content value for each fuel shall be based on a heat content analysis. NR 428.23(1)(b)5.c.c. The mass of NOx emissions shall be determined on an hourly basis by either multiplying the NOx concentration by the flue gas flow rate corrected for diluent gas and moisture or, by multiplying the monitored hourly average emission rate in mass per mmBtu by the total heat input as determined under subd. 5. a. or b. The calculations of mass emissions are to be performed according to conversion procedures in 40 CFR part 75, Appendix F, incorporated by reference in s. NR 484.04 (26m) (d). NR 428.23(1)(b)5.d.d. For a liquid or gaseous fuel fired system, the total heat input and mass of NOx emissions may be determined using a fuel flow monitoring system capable of determining the hourly flow with plus or minus 5% accuracy and using continuous parametric monitoring as specified under subd. 2. e. The total heat input shall be calculated as the total fuel flow multiplied by the fuel heat content. NR 428.23(1)(b)6.6. ‘General monitoring requirements.’ Unless otherwise specified in this subsection, an owner or operator shall meet the following requirements: NR 428.23(1)(b)6.b.b. The determination of emission rates, mass emissions and total heat input shall be calculated and corrected to the same basis for flue gas moisture and diluent gases according to Method 19 of 40 CFR part 60, Appendix A, incorporated by reference in s. NR 484.04 (16m), or 40 CFR part 75, Appendix F, incorporated by reference in s. NR 484.04 (26m) (d). NR 428.23(1)(b)6.c.c. For emissions units with a common flue gas stack system, all sampling locations and apportionment of emissions to an individual emissions unit shall conform to applicable procedures and methods in 40 CFR part 75, Appendix F, incorporated by reference in s. NR 484.04 (26m) (d). NR 428.23(1)(b)7.7. ‘Malfunction and abatement.’ An owner or operator of an emissions unit subject to the malfunction and abatement plan requirement of s. NR 439.11 shall include a malfunction plan for the emissions monitoring system and a monitoring and operating plan for continuing operation of the emissions unit in a manner consistent with meeting all applicable emission limitations during any period when the monitoring system malfunctions or is inoperable other than for scheduled maintenance. NR 428.23(1)(b)8.8. ‘Alternate emissions monitoring.’ An owner or operator of an emissions unit may request and monitor NOx emissions for compliance determination purposes using an equivalent alternative method to any requirement of this subsection with written approval of the department and the administrator. NR 428.23(1)(b)9.a.a. The owner or operator of an emissions unit that installs and operates a continuous NOx emissions monitoring system according to the requirements of 40 CFR part 75 shall satisfy the applicable monitoring requirements of this section. NR 428.23(1)(b)9.b.b. The owner or operator of an emissions unit that installs and operates a continuous NOx emissions monitoring system according to the requirements of 40 CFR part 60 shall satisfy the applicable monitoring requirements of subd. 3. NR 428.23(2)(2) Compilation of emissions. An owner or operator shall compile the measured emissions data in measurement units consistent with the units of the applicable emission limitation according to the following applicable calculation and tabulation methods for purposes of demonstrating compliance: NR 428.23(2)(a)1.1. The average emission rate shall be the average of the hourly average emissions obtained from the continuous emissions monitoring system for the hours the emissions unit operated during the averaging period. The calculation is as follows: where:
EA is the average emission rate for the compliance period in units consistent with units of the applicable emission limit
EH, j is the hourly average emission rate for each hour, j, for which the emissions unit is operating during the compliance period in units consistent with units of the applicable emission limit
n is the total number of hours the emissions unit operated during the compliance period
NR 428.23(2)(a)2.2. The 30-day rolling period shall consist of the day of monitoring and the previous 29 consecutive calendar days. A new 30-day rolling average emission rate (EA) shall be calculated and recorded at the end of each day. NR 428.23(2)(b)(b) Emissions performance testing. When measuring emissions according to performance testing requirements of sub. (1) (b) 3., the 30-day rolling average emission rate or concentration shall be the emissions determined in sub. (1) (b) 3. d. for the most recent performance test. NR 428.23(2)(c)(c) Multiple fuel-fired emissions units. When measuring emissions for an emissions unit firing multiple fuels, compliance shall be determined according to one of the following methods: NR 428.23(2)(c)1.1. The unit’s emissions shall be monitored and compiled according to applicable methods in par. (a) or (b) for each individual fuel and compliance demonstrated with the emission limitation for each fuel. NR 428.23(2)(c)2.2. The unit’s emissions and a multiple fuel emission limit shall be determined on a total heat input fuel weighted basis according to equation 3. A fuel representing less than 1% of the unit’s annual fuel consumption on a heat input basis may be excluded in determining the multiple fuel emission limit. where:
EHIWeighted is the heat input weighted multiple fuel emission rate or emission limitation for the compliance period in units consistent with the units of the emission limitation
Ef is the emission rate or emission limit for fuel f during the compliance period in units consistent with the units of the emission limitation
HIf is the total heat input for fuel f during the compliance period
n is the number of different fuels used during the compliance period
NR 428.23(2)(d)(d) Total heat input and mass emissions. When measuring hourly heat input or mass of NOx emissions according to sub. (1) (b) 5., the totals over a period of time shall be compiled according to the following procedures: NR 428.23(2)(d)1.1. The total hourly heat input shall be summed for the hours the emissions unit operated during the applicable period of time according to equation 4. where:
HItotal is the total heat input by fuel over the period of time
HIh is the heat input by fuel for hour h
n is the number of hours over which the specific fuel was burned
NR 428.23(2)(d)2.2. The total hourly mass of NOx emissions shall be summed for the hours the emissions unit operated during the applicable period of time according to equation 5. where:
NOx Masstotal is the total mass of NOx emissions over the period of time
Massh is the mass of NOx emissions for hour h
n is the number of hours the emissions unit is operating during the specified period of time
NR 428.23 HistoryHistory: CR 07-016: cr. Register July 2007 No. 619, eff. 8-1-07; CR 08-103: am. (1) (b) 1., cr. (1) (b) 9. Register August 2009 No. 644, eff. 9-1-09. NR 428.24NR 428.24 Recordkeeping and reporting. NR 428.24(1)(1) Emission limitations. The owner or operator of an emissions unit subject to an emission limitation in s. NR 428.22 shall meet the recordkeeping and reporting requirements of this subsection. NR 428.24(1)(a)(a) Recordkeeping. In addition to the recordkeeping requirements of ss. NR 439.04 (1) and (2) and 439.05, the owner or operator shall maintain records of all of the following: NR 428.24(1)(a)1.1. The applicable emission limit and calculated heat input weighted emission limit for an emissions unit demonstrating compliance for multiple fuels. NR 428.24(1)(a)3.3. The total monthly heat input for each fuel or the emissions unit output, as applicable, in measurement units consistent with the units of the applicable emission limitation. NR 428.24(1)(a)4.4. The emissions unit’s annual and ozone season capacity utilization in measurement units consistent with the units of the applicable emission limitation. NR 428.24(1)(a)5.5. For the emissions monitoring system required in s. NR 428.23 (1) (b) on an annual and on an ozone season basis, records of performed maintenance, hours of malfunction and necessary repairs, and the percent of hours the monitoring system operated during the emissions unit’s operating hours. NR 428.24(1)(b)1.1. A certification of compliance with the applicable emission limitation in s. NR 428.22 or identification of the periods of non-compliance, with a quantification of the excess emission rate and the excess mass emissions. NR 428.24(1)(b)2.2. For each calendar month, the highest 30-day rolling average emission rate. The emissions data shall be reported in the measurement units of the applicable emission limitation. NR 428.24(1)(b)3.3. The emissions unit’s annual and ozone season total operating hours, capacity utilization, and the percent operation of any required continuous emissions or combustion monitoring systems during the hours the emissions unit was operating. NR 428.24(1)(c)(c) Secondary fuel usage recordkeeping. The owner or operator claiming exemption from the requirements under s. NR 428.22 pursuant to s. NR 428.22 (3) shall keep a record of all of the following:
