R 336.1842 RACT emission limitations for boilers.

Rule 842. (1) As used in this rule: (a) “Boiler” means an enclosed device using controlled flame combustion and having the primary purpose of recovering thermal energy in the form of steam or hot water. (b) “Limited use boiler” means a boiler that burns an amount of solid, liquid, or gaseous fuels and has a federally enforceable annual capacity factor of no more than 10%. (2) A person shall not cause or allow the emission of NOx from the combustion of fuels in boilers in excess of the requirements of this rule at facilities meeting either of the following criteria: (a) Located in the 2015 ozone nonattainment areas and either of the following: (i) A stationary source with a potential to emit 100 tons per year or greater of NOx from all combined NOx sources upon the effective date of this rule. (ii) A emission unit installed after the effective date of this rule. (b) Has at any time been subject to the requirements of this rule. The requirements in this rule, at a minimum, must permanently apply regardless of any change in the attainment or maintenance status of the stationary source location or the potential to emit of the stationary source. (3) If an exemption is utilized, all applicable requirements of R 336.1846 must be met. If the boiler is not utilizing an exemption listed below, all provisions of this rule apply. Boilers may utilize the following exemptions from all provisions of this rule except subrule (8)(d): (a) Boilers with a heat input capacity rating of less than 20 MMBtu/hr. (b) Boilers subject to federal regulations under 40 CFR part 60, part 61, or part 63 if the applicable regulations are included in the state implementation plan and have equivalent standards established to be equal to or more stringent than the requirements and limits of subrule (4) of this rule. (c) Limited use boilers. (4) Except as allowed under R 336.1845, or as required by subrule (10) of this rule, a person that generates NOx emissions from the use of a subject boiler shall meet the following provisions on and after the effective date of this rule, as applicable: (a) The following NOx limits within table 842: TABLE 842 NOx emission limits for boilers Fuel Type Lbs of NOx per million Btu of heat input on hourly basis a All boilers: > 20 MMBTU/hr =< 50 MMBtu/hr N/A Gaseous fuels: > 50 MMBtu/hr 0.10 Distillate Oil: > 50 MMBtu/hr 0.12 Residual Oil: > 50 MMBtu/hr 0.25 Solid fuels: > 50 MMBtu/hr, < 100 MMBtu 0.35 Solid fuels: => 100 MMBtu 0.25 a Except for alternative averaging periods as allowed in subrule (7)(b)of this rule. (b) A boiler installed after the effective date of this rule must utilize a low NOx burner, equivalent technology, or better technology. (c) For emission units operating with a combination of gas, oil, or other fuels, a variable emission limit calculated as the heat input weighted average of the applicable emission limits must be used. The emission limit must be determined as follows: Emission limit = ∑ (𝑃𝑖)(𝐿𝑖) 𝑛 𝑖=1 Where: Pi = Percentage of total heat input from fuel listed in table 842 on a 24-hr basis Li = Applicable limit for fuel listed in table 842 n = Number of different fuel types (5) The person subject to this rule shall conduct a tune-up of each boiler at the following frequency: (a) For a boiler subject to the tune-up requirements of 40 CFR part 63, subpart DDDDD, JJJJJJ, and UUUUU adopted by reference in R 336.1902, tune-ups must be conducted in the manner and frequency as prescribed in that rule. (b) All boilers not described in subrule (5)(a) must undergo a tune-up following the requirements in subrule (6) at the frequency indicated in table 842a. TABLE 842a Boiler tune-up frequency by emission unit type. Boiler Type Frequency of tune-up Natural gas-fired or equipped with an oxygen analyzer system Every 5 years but no more than 61 months after the last tune-up All other fuels Once every year but no longer than 13 months after the last tune-up (6) For boilers that are subject to subrule (5)(b) of this rule, the person subject to this rule shall meet the following tune-up related requirements on and after the effective date of this rule, as applicable: (a) Create and implement a plan for the boiler that is approvable by the department. At a minimum, this plan must address the following details regarding tune-ups and denote the frequency these activities shall occur: (i) Inspection of the burner, and cleaning or replacement of any components of the burner as necessary. (ii) Inspection of the flame pattern and adjustments of the burner as necessary to optimize the flame pattern. The adjustment must be consistent with the manufacturer's specifications, if available. (iii) Inspection of the system controlling the air-to-fuel ratio, as applicable, and confirmation that it is correctly calibrated and functioning properly. (iv) Optimization of total emissions of NOx and carbon monoxide, CO. This should be consistent with the manufacturer's specifications, if available, and with any NOx requirement to which the emission unit is subject. (v) Measurement of the concentrations in the effluent stream of CO in parts per million by volume, and oxygen in volume percent, before and after the adjustments are made. Measurements may be on either a dry or wet basis, as long as it is the same basis before and after the adjustments are made. Measurements may also be taken using a properly operated and maintained portable CO analyzer. (vi) If the emission unit is shutdown on the required date for tune-up activities, the tune- up must be conducted as soon as practicable, but no longer than 30 days after startup. (b) To the extent practicable, maintain and operate the boiler in a manner consistent with good air pollution control practice for minimizing emissions at all times including during startup, shutdown, and malfunction. Determination of whether such operation and maintenance procedures are being used is based on information available to the department that may include, but is not limited to, monitoring results and review of operation and maintenance procedures and records. (7) For boilers subject to an emission rate limit specified in subrule (4) of this rule, compliance must be determined by using 1 of the following: (a) If a performance test has not been done within the last 18 months before the effective date of this rule, the person subject to this rule shall conduct an initial performance test, acceptable to the department, within 180 days after the effective date of this rule to demonstrate compliance with the required emission rate limit, or within 30 days after startup if the unit is not operating. An acceptable performance test must then be completed every 24 months, after the date of the last test, consistent with the requirements of R 336.2004. A performance test that determines that the emission unit complies with the limit in table 842 must be presumed to comply with this limit as long as the emission unit maintains regularly scheduled tune-ups required in subrule (5) of this rule until the next performance test is conducted. The 24-month frequency may be increased to once every 5 years when the most recent test results are 75% of the limit and the source certifies no other tests or information indicates a value over 75% of the limit. (b) An approvable plan must be submitted to the department describing how the NOx emissions are monitored. The monitoring plan must include the performance of periodic monitoring that is sufficient to yield reliable data from relevant time periods representative of the source’s compliance with the emission rates specified in subrule (4) of this rule. Periodic monitoring may include the following: (i) A parametric monitoring program that specifies operating parameters, and their ranges, that will provide reasonable assurance that each boiler’s emissions are consistent with the requirements of this rule. (ii) A predictive emissions measurement system that relies on automated data collection from instruments. If a boiler is equipped with a predictive emission monitoring system, then compliance with the applicable emissions limit must be determined based on the 30- day rolling average of the hourly arithmetic average emissions rates. (iii) A continuous emission monitoring system that complies with 40 CFR part 60 or part 75, both adopted by reference in R 336.1902. If a boiler is equipped with a continuous emission monitoring system, compliance with the applicable emissions limit must be determined based on the 30-day rolling average of the hourly arithmetic average emissions rates. (8) A person operating a boiler subject to this rule shall obtain current information and maintain records for all requirements or exemptions in sufficient detail to determine compliance. The information and records must be made available to the department upon request. Examples of acceptable information and records include, but are not limited to the following: (a) Installation dates of the boiler. (b) Records of tune-ups and related inspections conducted in accordance with subrule (5) of this rule and all associated records for a minimum of 5 years. (c) Either the results of the most recent stack test, or a minimum of 5 years of all monitoring data necessary to demonstrate compliance with limits and requirements in subrule (4) of this rule, or both, as applicable. (d) If the provisions of this rule are not applicable as allowed by subrule (3) of this rule, all information necessary to demonstrate that the equipment meets the exemption being utilized. (9) If records are not requested by the department for any 3-year rolling period, the facility will submit a report to the department with information and records in sufficient detail to determine compliance with the limits in this rule. (10) A person that generates NOx emissions from the use of a boiler located in the 2015 ozone nonattainment area shall meet the following limits within table 842b 12 months after the effective date of a final determination by the USEPA, pursuant to section 182(c)(9) of the clean air act 42 USC 7511a, for either of the following elements of the 2015 ozone National Ambient Air Quality Standard: (a) The USEPA issues a determination that reasonable further progress as described in Michigan’s approved state implementation plan was not achieved. (b) The USEPA makes a determination that the area failed to attain the standard by the applicable attainment date. TABLE 842b NOx emission limits for boilers Fuel Type Lbs of NOx per million Btu of heat input on hourly basis a All boilers > 20 MMBTU/hr =< 50 MMBtu/hr N/A Gaseous fuels; > 50 MMBtu/hr 0.08 Distillate Oil; > 50 MMBtu/hr 0.10 Residual Oil ; > 50 MMBtu/hr 0.20 Solid fuels; > 50 MMBtu/hr , < 100 MMBtu 0.30 Solid fuels; => 100 MMBtu 0.20 a Except for alternative averaging periods as allowed in subrule (7)(b) of this rule. Editor's Note: An obvious error in R 336.1842 was corrected at the request of the promulgating agency, pursuant to Section 56 of 1969 PA 306, as amended by 2000 PA 262, MCL 24.256. The rule containing the error was published in Annual Administrative Code Supplement 2025. The memorandum requesting the correction was published in Michigan Register, 2026 MR 16.