Chapter NR 439

NR 439.085(2)(d)4. 4. Weighted average heat content expressed in Btu per pound of the coal burned.

NR 439.085(2)(d)5. 5. Weighted average sulfur dioxide emission rate in terms of pounds of sulfur dioxide per million Btu heat input from the coal burned.

NR 439.085(2)(e) (e) The owner or operator of a coal burning installation which has a coal burning rate less than 1,000 tons per year shall retain copies of the supplier’s analyses at the installation for each shipment of coal received. The owner or operator shall obtain certification from the supplier that the applicable methods and procedures in s. NR 439.08 (1) were followed. The supplier’s analyses shall include, at a minimum, each shipment’s coal quantity, sulfur content, ash content and heat content.

NR 439.085(3) (3) Requirements for residual fuel oil burning installations. The residual fuel burning rate for an installation shall be based on the maximum permitted capacity. If the permit does not limit the capacity, the total heat input capacity shall be used:

NR 439.085(3)(a) (a) The owner or operator of a residual fuel oil burning installation which has a residual fuel oil burning rate equal to or greater than 1.5 million gallons per year shall sample residual fuel oil and submit reports on residual fuel oil quality in the following manner:

NR 439.085(3)(a)1. 1. Perform liquid fossil fuel sampling for each storage tank of residual fuel oil and analyze these samples for sulfur content and heat content according to the applicable methods and procedures for sampling and analysis in s. NR 439.08 (2). Sampling shall be performed for each tank volume turnover or on a monthly basis, whichever is more frequent.

NR 439.085(3)(a)2. 2. Submit quarterly reports within 30 calendar days following the end of each calendar quarter that include all of the following information for each month during the calendar quarter:

NR 439.085(3)(a)2.a. a. Total quantity of residual fuel oil burned expressed in thousands of gallons.

NR 439.085(3)(a)2.b. b. Weighted average percent of the sulfur content of the residual fuel oil burned.

NR 439.085(3)(a)2.c. c. Weighted average heat content expressed in Btu per gallon of residual fuel oil burned.

NR 439.085(3)(a)2.d. d. Weighted average sulfur dioxide emission rate in terms of pounds of sulfur dioxide per million Btu heat input from the residual fuel oil burned.

NR 439.085(3)(b) (b) The owner or operator of a residual fuel oil burning installation that has a residual fuel oil burning rate equal to or greater than 150,000 gallons per year but less than 1.5 million gallons per year shall submit, on a quarterly basis, information on residual fuel oil quality which is calculated from the supplier's analyses for each shipment of residual fuel oil received at the installation. Each quarterly report is due within 30 calendar days following the end of the calendar quarter. The owner or operator of the installation shall obtain certification from the supplier that the applicable methods and procedures under s. NR 439.08 (2) were followed by the supplier. The report shall include all of the following information for each calendar quarter:

NR 439.085(3)(b)1. 1. Total quantity of residual fuel oil burned expressed in thousands of gallons.

NR 439.085(3)(b)2. 2. Weighted average percent of the sulfur content of the residual fuel oil burned.

NR 439.085(3)(b)3. 3. Weighted average heat content expressed in Btu per gallon of residual fuel oil burned.

NR 439.085(3)(b)4. 4. Weighted average sulfur dioxide emission rate in terms of pounds of sulfur dioxide per million Btu heat input from the residual fuel oil burned.

NR 439.085(3)(c) (c) The owner or operator of a residual fuel oil burning installation which has a residual fuel oil burning rate less than 150,000 gallons per year shall retain copies of the supplier’s analyses at the installation for each shipment of residual fuel oil received. The owner or operator shall obtain certification from the supplier that the applicable methods and procedures in s. NR 439.08 (2) were followed. The supplier’s analyses shall include, at a minimum, each shipment’s residual fuel oil quantity, sulfur content and heat content.

NR 439.085(4) (4) Requirements for installations burning fuels other than coal or residual fuel oil. The owner or operator of an installation subject to reporting requirements under s. NR 439.03 which burns fuel other than coal or residual fuel oil may be required to sample and analyze the fuel used in a manner specified by the department.

NR 439.085 History History: Renum. from NR 439.075 (2) and am., cr. (4), Register, May, 1992, No. 437, eff. 6-1-92; am. (2) (a) 1., Register, February, 1995, No. 470, eff. 3-1-95; am. (2) (a) 1., (b) 1. and (c) 1., Register, November, 1999, No. 527, eff. 12-1-99; CR 00-175: am. (2) (a) 1., (b) 1. and (c) 1. Register March 2002 No. 555, eff. 4-1-02; CR 02-146: am. (2) (a) 1., (b) 1., (c) 1. and (3) (a) 1., cr. (3) (intro.) Register October 2003 No. 574, eff. 11-1-03; CR 05-116: am. (2) (a) 1., (b) 1. and (c) 1. Register November 2006 No. 611, eff. 12-1-06; CR 24-030: am. (2) (a) 1., 2. (intro.), (b) 1., 2. (intro.), (c) 1., 2. (intro.), (d) (intro.), (3) (a) 2. (intro.), (b) (intro.) Register June 2025 No. 834, eff. 7-1-25.

NR 439.09 NR 439.09 Methods and procedures for continuous emission monitoring. The owner or operator of a source conducting continuous emission monitoring under s. NR 439.095 shall use the methods and procedures listed in this section to install, calibrate, maintain and operate a continuous emissions monitoring system, or other methods and procedures approved, in writing, by the department:

NR 439.09(1) (1) Continuous emissions monitoring systems for measuring opacity shall comply with all of the provisions and requirements in Performance Specification 1 in 40 CFR part 60, Appendices B and F, incorporated by reference under s. NR 484.04 (21) and (21m).

NR 439.09(2) (2) Continuous emissions monitoring systems for measuring sulfur dioxide or nitrogen oxides shall comply with all the provisions and requirements in Performance Specification 2 in 40 CFR part 60, Appendices B and F or, for affected units, the performance specifications in 40 CFR part 75, Appendices A to I, incorporated by reference under s. NR 484.04 (21), (21m), and (27).

NR 439.09(3) (3) Continuous emissions monitoring systems for measuring oxygen or carbon dioxide shall comply with all the provisions and requirements in Performance Specification 3 in 40 CFR part 60, Appendices B and F or, for affected units, the performance specifications in 40 CFR part 75, Appendices A to I, incorporated by reference under s. NR 484.04 (21), (21m), and (27).

NR 439.09(4) (4) Continuous emissions monitoring systems for measuring carbon monoxide shall comply with all the provisions and requirements in Performance Specification 4, 4A, or 4B in 40 CFR part 60, Appendices B and F, incorporated by reference under s. NR 484.04 (21) and (21m).

NR 439.09(5) (5) Continuous emissions monitoring systems for measuring total reduced sulfur shall comply with all the provisions and requirements in Performance Specification 5 in 40 CFR part 60, Appendix B, incorporated by reference in s. NR 484.04 (21).

NR 439.09(6) (6) Continuous emission rate monitoring systems shall comply with all the provisions and requirements in Performance Specification 6 in 40 CFR part 60, Appendix B, incorporated by reference in s. NR 484.04 (21).

NR 439.09(7) (7) Continuous emissions monitoring systems for measuring hydrogen sulfide shall comply with all the provisions and requirements in Performance Specification 7 in 40 CFR part 60, Appendices B and F, incorporated by reference under s. NR 484.04 (21) and (21m).

NR 439.09(7m) (7m) Continuous emissions monitoring systems for measuring VOCs or total hydrocarbons shall comply with all the provisions and requirements in Performance Specification 8 or 8A in 40 CFR part 60, Appendices B and F, incorporated by reference under s. NR 484.04 (21) and (21m).

NR 439.09(7p) (7p) Continuous emissions monitoring systems for measuring filterable particulate matter shall comply with all the provisions and requirements in Performance Specification 11 in 40 CFR part 60, Appendices B and F, incorporated by reference under s. NR 484.04 (21) and (21m).

NR 439.09(7r) (7r) Continuous emissions monitoring systems for measuring mercury shall comply with all the provisions and requirements in Performance Specifications 12 and 12A in 40 CFR part 60, Appendices B and F, incorporated by reference under s. NR 484.04 (21) and (21m).

NR 439.09(7t) (7t) Continuous monitoring systems for predictive emissions monitoring shall comply with all the provisions and requirements in Performance Specification 16 in 40 CFR part 60, Appendix B, incorporated by reference under s. NR 484.04 (21).

NR 439.09(7v) (7v) Continuous emissions monitoring systems for measuring hydrogen chloride shall comply with all the provisions and requirements in Performance Specification 18 in 40 CFR part 60, Appendices B and F, incorporated by reference under s. NR 484.04 (21) and (21m).

NR 439.09(8) (8) The owner or operator of a continuous emissions monitoring system shall comply with the quality control and quality assurance plan submitted by the owner or operator of the source and approved by the department.

NR 439.09(9) (9) Continuous emissions monitoring systems shall meet the following minimum frequency of operation requirements:

NR 439.09(9)(a) (a) Opacity monitors shall complete at least one cycle of sampling and analyzing for each successive 10-second period and one cycle of data recording for each successive 6-minute period.

NR 439.09(9)(b) (b) Monitors for sulfur dioxide, nitrogen oxides, oxygen, carbon dioxide, carbon monoxide, hydrogen sulfide, total reduced sulfur, filterable particulate matter, mercury as measured by an analyzer, hydrogen chloride, predictive emission monitoring system, and VOCs shall complete at least one cycle of sampling, analyzing, and data recording for each successive 15-minute period. The values recorded shall be averaged hourly. Hourly averages shall be computed from at least 4 data points equally spaced over each one-hour period, except during periods when calibration, quality assurance, or maintenance activities are being performed. During these periods, a valid hour shall consist of at least 2 data points separated by a minimum of 15 minutes, with one valid data point in each of the 15-minute quadrants of the hour.

NR 439.09(10) (10) 

NR 439.09(10)(ag) (ag) The owner, operator, or designee of a continuous emissions monitoring system shall submit quarterly summary excess emission reports to the department within 30 calendar days following the end of each calendar quarter. The summary excess emission report shall include all of the following:

NR 439.09(10)(ag)1. 1. Pollutant monitored.

NR 439.09(10)(ag)2. 2. Stack and process.

NR 439.09(10)(ag)3. 3. Pollutant emission limitation.

NR 439.09(10)(ag)4. 4. Reporting period date range.

NR 439.09(10)(ag)5. 5. Total source operating time in reporting period.

NR 439.09(10)(ag)6. 6. Facility name and address.

NR 439.09(10)(ag)7. 7. Monitor manufacturer and model number.

NR 439.09(10)(ag)8. 8. Dates of latest monitor audit and certification.

NR 439.09(10)(ag)9. 9. Type of monitor audit and applicable results.

NR 439.09(10)(ag)10. 10. Duration of excess emissions by category: startup/shutdown, sootblowing, fuel problems, process malfunction, control equipment malfunction, other known causes, unknown causes, and sum of excess emissions.

NR 439.09(10)(ag)11. 11. Duration of monitor downtime by category including monitor equipment malfunction, non-monitor equipment malfunction, quality assurance/quality control calibration, other known causes, unknown causes, and sum of monitor downtime.

NR 439.09(10)(ag)12. 12. The percent of operating time with excess emissions or monitor downtime calculated as the sum of excess emissions or monitor downtime divided by the total source operating time in the reporting period, multiplied by 100.

NR 439.09(10)(ag)13. 13. A statement indicating that the information in the report is true, accurate, and complete.

NR 439.09(10)(ag)14. 14. The owner or operator’s name, title, and signature, and the date.

NR 439.09(10)(ar) (ar) If the total duration of excess emissions is 1 percent or greater or the total continuous emission monitoring system downtime is 5 percent or greater for the reporting period specified under par. (ag), then the owner, operator, or designee of a continuous emissions monitoring system shall submit both the summary excess emission report required under par. (ag) and a full excess emission report to the department within 30 calendar days following the end of each calendar quarter. The full excess emission report required under this paragraph shall contain all of the following information:

NR 439.09(10)(ar)1. 1. The date and starting and ending times or duration of each period of excess emissions and the magnitude of the emissions.

NR 439.09(10)(ar)2. 2. The periods of excess emissions that occur during startups, shutdowns, sootblowing, control equipment malfunction, process malfunction, fuel problems, other known causes or for unknown causes. The report shall identify the cause of any malfunction and the measures taken to reduce excess emissions.

NR 439.09(10)(ar)3. 3. The date and starting and ending time of any period during which the monitoring system was inoperative for any reason or causes, including monitor malfunction or calibration, except for zero and span checks. The report shall identify the repairs or adjustments made to the system.

NR 439.09(10)(ar)4. 4. The date and starting and ending time of any period during which the process being monitored was inoperative.

NR 439.09(10)(ar)5. 5. When no period of excess emissions occurred during the quarter and the monitoring system had no period of downtime, an excess emissions report shall be filed stating such information.

NR 439.09(10)(b) (b) Unless otherwise specified by the department or an applicable standard, in the reports required under this subsection, periods of excess emissions shall be reported as follows:

NR 439.09(10)(b)1. 1. For opacity, any 6-minute period during which the average opacity exceeds the applicable emission limit.

NR 439.09(10)(b)6. 6. For all other air pollutants, any one-hour period during which the average emissions exceed the applicable emission limitation.

NR 439.09(10)(c) (c) For purposes of reporting exceedances on the basis of a 24-hour rolling average under this subsection, any hourly average may be included in only one 24-hour period. An exceedance shall be based on at least 18 and not more than 24 valid recordings of hourly average emission rates in any 24 hour period.

NR 439.09 History History: Renum. from NR 439.07 (3) and am., cr. (8) (intro.), Register, May, 1992, No. 437, eff. 6-1-92; r. and recr. (6) to (8), cr. (9) and (10), Register, December, 1993, No. 456, eff. 1-1-94; cr. (7m), am. (9) (b), Register, June, 1994, No. 462, eff. 7-1-94; am. (1) to (7), Register, February, 1995, No. 470, eff. 3-1-95; am. (2), (3), Register, April, 1995, No. 472, eff. 5-1-95; CR 02-146: am. (intro.) Register October 2003 No. 574, eff. 11-1-03; CR 24-030: am. (1) to (4), (7), (7m), cr. (7p) to (7v), am. (9) (a), (b), renum. (10) (intro.) to (10) (ag) (intro.) and am., cr. (10) (ag) 1. to 14., renum. (10) (a) to (10) (ar) and, as renumbered, am. (10) (ar) (intro.), am. (10) (b) (intro.), r. (10) (b) 2. to 5., cr. (10) (b) 6., r. (10) (d). Register June 2025 No. 834, eff. 7-1-25.

NR 439.095 NR 439.095 Continuous emission monitoring requirements.

NR 439.095(1) (1) Applicability and general requirements. Except as provided under sub. (2), the owner or operator of a stationary source listed in this subsection shall install, calibrate, operate, and maintain all monitoring equipment necessary for continuously monitoring the pollutants specified in this subsection for the applicable source. The type of monitoring equipment used and the manner and location of its installation are subject to prior department approval. The sources and their respective monitoring requirements are as follows:

NR 439.095(1)(a) (a) Fossil fuel fired steam generating units identified in sub. (5) shall be monitored for opacity, nitrogen oxide emissions, sulfur dioxide emissions, and oxygen or carbon dioxide.

NR 439.095(1)(b) (b) Fluid bed catalytic cracking unit catalyst regenerators identified in sub. (5) shall be monitored for opacity.

NR 439.095(1)(c) (c) Sulfuric acid plants identified in sub. (5) shall be monitored for sulfur dioxide emissions.

NR 439.095(1)(d) (d) Nitric acid plants identified in sub. (5) shall be monitored for nitrogen oxide emissions.

NR 439.095(1)(e) (e) Yeast manufacturing fermenters identified in sub. (5) shall be monitored for VOCs.

NR 439.095(1)(f) (f) Phase I and phase II acid rain units identified in sub. (5) shall be monitored for sulfur dioxide, nitrogen oxides, carbon dioxide, stack flow rate and opacity.

NR 439.095(1)(g) (g) Stationary sources, required under an enforcement agreement or which have elected to use continuous emission monitoring to determine compliance with applicable rules, shall monitor for the parameters and pollutants for which they have installed the monitoring device. Those parameters may include stack flow rate, opacity, or emissions of nitrogen oxides, sulfur dioxide, total reduced sulfur, carbon dioxide, VOCs, and hazardous air contaminants.

NR 439.095(2) (2) Exemptions. The department may grant an exemption from any monitoring requirement under this section for any source that is subject to a continuous emission monitoring requirement under another applicable standard or requirement.

NR 439.095(3) (3) Installation deadlines. The owner or operator of a source which is required under sub. (1) to install continuous monitoring equipment shall complete the installation and performance tests of the equipment and begin monitoring and recording not later than April 1, 1989, except as provided in pars. (a) and (b). The department may grant requests for extensions of the time provided for installation of monitors for facilities unable to meet the prescribed time frame if the owner or operator of the facility demonstrates that good faith efforts have been made to obtain and install the devices within the prescribed time frame.

NR 439.095(3)(a) (a) For new sources, monitoring and recording shall begin upon startup.

NR 439.095(3)(b) (b) For boilers connected to a single stack which have individual coal burning rates of less than 25,000 tons per year but which have a combined coal burning rate of 25,000 tons or more per year, monitoring and recording shall begin not later than January 1, 1993.

NR 439.095(4) (4) Monitoring system malfunction. The department may grant a temporary exemption from the monitoring and reporting requirements of this section during any period of monitoring system malfunction if the source owner or operator shows, to the satisfaction of the department, that the malfunction was unavoidable and is being repaired as expeditiously as practicable.

NR 439.095(5) (5) Minimum monitoring requirement. The owner or operator of a source listed in this subsection shall, as a minimum, meet the monitoring requirements of this subsection and sub. (1).

NR 439.095(5)(a) (a) Fossil fuel fired steam generating units. Except as provided for under par. (f) or (g), the owner or operator of a fossil fuel fired steam generating unit subject to sub. (1) shall comply with the monitoring requirements of this paragraph:

NR 439.095(5)(a)1. 1. Opacity. The owner or operator of any steam generating unit which has a total heat input capacity equal to or greater than 250 million Btu per hour shall install, calibrate, maintain and operate a continuous monitoring system which meets the performance specifications of sub. (6) for the measurement of opacity from each stack serving a coal fired boiler or boilers with a maximum combined coal burning rate equal to or greater than 25,000 tons per year, unless the source utilizes an alternative method of compliance determination approved, in writing, by the department.

NR 439.095(5)(a)2. 2. Sulfur dioxide. The owner or operator of any steam generating unit shall install, calibrate, maintain and operate a continuous monitoring system which meets the performance specifications of sub. (6) for the measurement of sulfur dioxide if one of the following applies:

NR 439.095(5)(a)2.a. a. The facility total heat input capacity is equal to or greater than 250 million Btu per hour and the facility has a control system which reduces sulfur dioxide emissions by more than 5% of the uncontrolled sulfur dioxide emission rate.

NR 439.095(5)(a)2.b. b. The maximum coal burning rate of all boilers at the facility which emit to a stack without a sulfur dioxide control system is equal to or greater than 100,000 tons of coal per year, unless the source utilizes an alternative method of compliance determination approved, in writing, by the department which meets the requirements of s. NR 439.085.

NR 439.095(5)(a)3. 3. Nitrogen oxides. The owner or operator of a fossil fuel fired steam generating unit with a capacity greater than 1000 million Btu per hour heat input which is located in a nonattainment area for nitrogen oxides shall install, calibrate, maintain and operate a continuous monitoring system for the measurement of the source’s nitrogen oxides emissions which meets the performance specifications of sub. (6), unless the source’s owner or operator demonstrates by a compliance emission test that the source emits nitrogen oxides at levels 30% or more below the applicable emission limit.

NR 439.095(5)(a)4. 4. Oxygen or carbon dioxide. The owner or operator of a fossil fuel fired steam generating unit where measurement of oxygen or carbon dioxide in the flue gas is required to convert either sulfur dioxide or nitrogen oxides continuous emission monitoring data, or both, to units of the applicable emission limitation shall install, calibrate, operate and maintain a continuous monitoring system for the measurement of percent oxygen or carbon dioxide which meets the performance specifications of sub. (6).

NR 439.095(5)(b) (b) Nitric acid plants. The owner or operator of a nitric acid plant of greater than 300 tons per day production capacity, expressed as 100% acid, which is located in a nonattainment area for nitrogen oxides shall install, calibrate, maintain and operate a continuous monitoring system for the measurement of nitrogen oxides which meets the performance specifications of sub. (6) for each nitric acid producing unit within the plant.

NR 439.095(5)(c) (c) Sulfuric acid plants. The owner or operator of a sulfuric acid plant of greater than 300 tons per day production capacity, expressed as 100% acid, shall install, calibrate, maintain and operate a continuous monitoring system for the measurement of sulfur dioxide which meets the performance specifications of sub. (6) for each sulfuric acid producing unit within the plant.

NR 439.095(5)(d) (d) Fluid bed catalytic cracking unit catalyst regenerators at petroleum refineries. The owner or operator of a catalyst regenerator for fluid bed catalytic cracking units of greater than 20,000 barrels per day fresh feed capacity shall install, calibrate, maintain and operate a continuous monitoring system for the measurement of opacity which meets the performance specifications of sub. (6).

NR 439.095(5)(e) (e) Yeast manufacturing plants. The owner or operator of any yeast manufacturing facility subject to s. NR 424.05 shall install, calibrate, maintain and operate a continuous monitoring system for the measurement of VOCs which meets the performance specifications of the department’s approval issued under sub. (1) for each fermenter which does not use add-on control equipment to meet the emission limitations of s. NR 424.05 (2) (a).