May 25, 2007 62.5. St. 5.2 - Page 1

SOUTH CAROLINA 

DEPARTMENT OF HEALTH AND ENVIRONMENTAL CONTROL 

AIR POLLUTION CONTROL REGULATIONS AND STANDARDS 

REGULATION 61-62. 5 

AIR POLLUTION CONTROL STANDARDS 

STANDARD NO. 5.2 

CONTROL OF OXIDES OF NITROGEN (NOx) 

SECTION I - APPLICABILITY 

(a) Except as provided in paragraph (b) of this part, the provisions of this regulation shall apply to any 

stationary source that emits or has the potential to emit oxides of nitrogen (NOx) generated from fuel 

combustion that has not undergone a Best Available Control Technology (BACT) analysis for NOx in 

accordance with SC Regulation 61-62.5, Standard No. 7 and that meets one or more of the criteria 

specified in paragraphs (a)(1), (a)(2), and (a)(3) of this part: 

 (1) Any new source that is constructed after June 25, 2004; 

 (2) Any existing source where a burner assembly is replaced with another burner assembly after the 

effective date of this regulation, regardless of size or age of the burner assembly to be replaced. The 

replacement of individual components such as burner heads, nozzles, or windboxes does not trigger the 

applicability of this regulation; or 

 (3) Any existing source that is removed from its presently permitted facility and moved to another 

permitted facility after the effective date of this regulation except process equipment and commercial or 

industrial boilers that are transferred between facilities within the state under common ownership. Such 

transfers will be considered as existing sources under (a)(2) above. 

(b) Exemptions: 

The following sources are exempt from all requirements of this regulation unless otherwise specified: 

 (1) Any source less than 10 x 106

 BTU/HR rated input capacity that burns a fuel. 

 (2) Emergency power generators as described below: 

 a. Generators of less than or equal to 150 KW rated capacity. 

 b. Generators of greater than 150 KW rated capacity designated for emergency use only and 

are operated a total of 500 hours per year or less for testing and maintenance and have a method to record 

the actual hours of use such as an hour meter. 

 (3) Any internal combustion engine with a mechanical power output of less than 200 bHP. 

 (4) Any device functioning solely as a combustion control device. Waste heat recovery from these 

combustion control devices shall not be considered primary grounds for exclusion from this exemption. 
May 25, 2007 62.5. St. 5.2 - Page 2

 (5) Any equipment that has NOx controls pursuant to the requirements 40 CFR Parts 60, 61, or 63 

where such controls are equivalent to, or more stringent than, the requirements of this regulation. 

 (6) Any source that has NOx controls pursuant to the requirements of SC Regulation 61-62.96, 

where such controls are equivalent to, or more stringent than, the requirements of this regulation. 

(7) Any source that has NOx controls pursuant to the requirements of SC Regulation 61-62.99. 

 (8) Flares 

 (9) Air Curtain Incinerators 

 (10) Fuel Cell Sources 

 (11) Engines test cells/stands

(12) Portable and temporary IC engines such as those associated with generators, air compressors, or 

other applications provided that they fall in the categories listed in 40 CFR 89, Control of Emissions from 

New and In-Use Nonroad Compression-Ignition Engines. 

 (13) Combustion sources that operate at a capacity of less than 10% per year. 

 (14) Special use burners, such as start-up/shut-down burners, that are operated less than 500 hours a 

year. 

 (15) Liquor guns on a recovery boiler are only exempt from the standard requirements in Section IV. 

 (16) Portable sources such as asphalt plants or concrete batch plants are only exempt from the 

standard requirements in Section III. 

 (17) The Department reserves the right to consider any other exemptions from this regulation on a 

case-by-case basis as appropriate. 

SECTION II - DEFINITIONS 

For the purposes of this regulation, the following definitions shall apply: 

Burner Assembly: Means any complete, pre-engineered device that combines air (or oxygen) and fuel in a 

controlled manner and admits this mixture into a combustion chamber in such a way as to ensure safe and 

efficient combustion. A self-contained chamber such as is found on a combustion turbine is not a burner 

assembly for the purposes of this regulation. 

Case-by-Case NOx Control: Means an emissions limitation based on the maximum degree of reduction 

for NOx which would be emitted from any new source which the Department, on a case-by-case basis, 

taking into account energy, environmental, and economic impacts and other costs, determines is 

achievable for such source through application of production processes or available methods, systems, 

and techniques. In no event shall application of NOx control result in emissions of any pollutant which 

would exceed the emissions allowed by any applicable standard. If the Department determines that 

technological or economic limitations on the application of measurement methodology to a particular 
May 25, 2007 62.5. St. 5.2 - Page 3

source would make the impositions of an emission standard infeasible, a design, equipment, work 

practice, operational standard, or combination thereof, may be prescribed instead to satisfy the 

requirement for the application of NOx control. Such standard shall, to the degree possible, set forth the 

emissions reduction achievable by implementation of such design, equipment, work practice or operation, 

and shall provide for compliance by means, which achieve equivalent results. 

Combustion Control Device: Means, but is not limited to, any equipment that is used to destroy or remove 

air pollutant(s) prior to discharge to the atmosphere, excluding boilers, process heaters, dryers, furnaces, 

digesters, ovens, combustors, and similar combustion devices. Such equipment includes, but is not limited 

to, thermal oxidizers, catalytic oxidizers, and flares. 

Constructed: Means the on-site fabrication, erection, or installation of the NOx emitting source. 

Fuel: Means the following or any combination of the following: virgin fuel, fossil fuel, waste, waste fuel, 

biomass fuel, biofuel, methanol, ethanol, biodiesel, landfill gas, digester gas, process liquid or gas, or any 

combustible material the Department determines to be a fuel. 

 

Source: Means an individual NOx emission unit. 

Tune-up: Means adjustments made to the combustion process to optimize combustion efficiency of the 

source in accordance with procedures provided by the manufacturer or in accordance with good 

engineering practices. 

SECTION III – STANDARD REQUIREMENTS FOR NEW SOURCES 

(a) Those sources as defined in Section I (a)(1) and (a)(3) shall apply NOx controls capable of achieving 

the limitations provided in Table 1 of this section. Unless otherwise noted, all emission limits identified 

in Table 1 are based on monthly averages. 

(b) A source may request an alternate control limitation by submitting a demonstration that the alternate 

limitation is a Case-by-Case NOx Control as defined in Section II. 

(c) The Department reserves the right to request that the owner or operator submit additional information 

for those sources that request alternate control limitation in accordance with Section III (b) above. 

(d) Sources required to install post combustion technology for the control of NOx, shall be required to 

use post combustion for the control of NOx during the ozone season (April 1 through October 31). 
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Table 1 - NOx Control Standards 

Source Type Control Technology and/or Emission Limit 

Boilers and Water Heaters 

Natural Gas Fired Boilers

>10mmBTU/hr and 

< 100mmBTU/hr 

Low NOx Burners or equivalent technology capable of achieving 

30ppmv @ 3% O2 Dry (0.036 lb/mmBTU) 

>100mmBTU/hr Low NOx Burners + Flue Gas Recirculation or equivalent technology 

capable of achieving 30 ppmv @ 3% O2 Dry (0.036 lb/mmBTU) 

Distillate Oil Fired Boilers 

>10mmBTU/hr and 

< 100mmBTU/hr 

Low NOx Burners or equivalent technology capable of achieving 

0.15 lb/mmBTU 

>100mmBTU/hr Low NOx Burners + Flue Gas Recirculation or equivalent technology 

capable of achieving 0.14 lb/mmBTU 

Residual Oil Fired Boilers

>10mmBTU/hr and 

< 100mmBTU/hr 

Low NOx Burners or equivalent technology capable of achieving 0.3 

lb/mmBTU 

>100mmBTU/hr Low NOx Burners + Flue Gas Recirculation or equivalent technology 

capable of achieving 0.3 lb/mmBTU 

Multiple Fuel Boilers

 The emission limits for boilers burning multiple fuels are calculated in accordance with the formulas 

below. Additional fuels shall be addressed on a case-by-case basis. 

>10mmBTU/hr and 

< 100mmBTU/hr 

En = [(0.036 lb/mmBTU Hng) + (0.15 lb/mmBTU Hdo) + (0.3 

lb/mmBTU Hro) + (0.35 lb/mmBTU Hc) + (0.2 lb/mmBTU Hw)]/(Hng

+ Hdo+ Hro + Hc + Hw) 

where: 

En is the nitrogen oxides emission limit (expressed as NO2), ng/J 

(lb/million Btu) 

Hng is the heat input from combustion of natural gas, 

Hdo is the heat input from combustion of distillate oil 

Hro is the heat input from combustion of residual oil, 

Hc is the heat input from combustion of coal, 

Hw is the heat input from combustion of wood residue. 
May 25, 2007 62.5. St. 5.2 - Page 5

Source Type Control Technology and/or Emission Limit 

>100mmBTU/hr En = [(0.036 lb/mmBTU Hng) + (0.14 lb/mmBTU Hdo) + (0.3 

lb/mmBTU Hro) + (0.25 lb/mmBTU Hc) + (0.2 lb/mmBTU Hw)]/(Hng

+ Hdo+ Hro + Hc + Hw) 

where: 

En is the nitrogen oxides emission limit (expressed as NO2), ng/J 

(lb/million Btu) 

Hng is the heat input from combustion of natural gas, 

Hdo is the heat input from combustion of distillate oil 

Hro is the heat input from combustion of residual oil, 

Hc is the heat input from combustion of coal. 

Hw is the heat input from combustion of wood residue. 

Wood Residue Boilers 

All types Combustion controls to minimize NOx emissions or equivalent 

technology capable of achieving 0.20 lb/mmBTU 

Coal Fired Stoker Fed Boilers

< 250 mmBTU/hr Combustion controls to minimize NOx emissions or equivalent 

technology capable of achieving 0.35 lb/mmBTU 

≥ 250 mmBTU/hr Combustion controls to minimize NOx emissions or equivalent 

technology capable of achieving 0.25 lb/mmBTU 

Pulverized Coal Fired Boilers

< 250 mmBTU/hr Low NOx Burners + Combustion controls to minimize NOx 

emissions or equivalent technology capable of achieving 

0.35 lb/mmBTU 

> 250 mmBTU/hr Low NOx Burners + Combustion controls to minimize NOx 

emissions + SCR or equivalent technology capable of 

achieving 0.14 lb/mmBTU 

Municipal refuse fired boilers

< 250 mmBTU/hr Combustion modifications to minimize NOx emissions + Flue 

Gas Recirculation or equivalent technology capable of 

achieving 200 ppmv @12% CO2 (0.35 lb/mmBTU) 

> 250 mmBTU/hr Staged Combustion and Automatic Combustion Air Control + 

SCR or equivalent technology capable of achieving 

0.18 lb/mmBTU 

Internal Combustion Engines

Compression Ignition Timing Retard < 4o + Turbocharger w/ Intercooler or equivalent 

technology capable of achieving 490 ppmv @ 15% O2 (7.64 gm/bhphr) 

Spark Ignition Lean Burn Technology or equivalent technology capable of 

Achieving 1.0 gm/bhp-hr 

Landfill or Digester Gas Fired Lean Burn Technology or equivalent technology capable of 

Achieving 1.25 gm/bhp-hr 

Gas Turbines
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Source Type Control Technology and/or Emission Limit 

Simple Cycle – Natural Gas 

< 50 Megawatts Combustion Modifications (e.g. dry low-NOx combustors) 

to minimize NOx emissions or equivalent technology capable of 

achieving 25 ppmv @ 15% O2 Dry (0.054 lb/mmBTU) 

> 50 Megawatts Combustion Modifications (e.g. dry low-NOx combustors) 

to minimize NOx emissions or equivalent technology capable 

of achieving 9.0 ppmv @ 15% O2 Dry (0.033 lb/mmBTU) 

Combined Cycle – Natural Gas 

< 50 Megawatts Dry Low-NOx Combustors or equivalent technology capable of 

achieving 9.0 ppmv @ 15% O2 Dry (0.033 lb/mmBTU) 

> 50 Megawatts Dry Low-NOx Combustors + SCR or equivalent technology 

Capable of achieving 3.0 ppmv @ 15% O2 Dry 

(0.011lb/mmBTU) 

Simple Cycle – Distillate Oil Combustion 

< 50 Megawatts Combustion Modifications and water injection to minimize 

NOx emissions or equivalent technology capable of achieving 

42 ppmv @ 15% O2 Dry Basis (0.16 lb/mmBTU) 

> 50 Megawatts Combustion Modifications and water injection to minimize 

NOx emissions or equivalent technology capable of achieving 

42 ppmv @ 15% O2 Dry Basis (0.16 lb/mmBTU) 

Combined Cycle - Distillate oil combustion 

< 50 Megawatts Dry Low-NOx Combustors with water injection, or equivalent 

technology capable of achieving 42 ppmv @ 15% O2 Dry Basis 

(0.16 lb/mmBTU) 

> 50 Megawatts Dry Low-NOx Combustors, water injection, and SCR or 

Equivalent technology capable of achieving 10 ppmv @ 15% 

O2 Dry Basis (0.038 lb/mmBTU) 

Landfill Gas Fired Water or steam injection or low NOx turbine design or equivalent 

technology capable of achieving 25 ppmv @ 15% O2 

(0.097 lb/mmBTU) 

Cement Kilns Low NOx burners or equivalent technology capable of achieving 30% 

reduction from uncontrolled levels. 

Fluidized Bed Combustion (FBC) Boiler:

Coal Fired SNCR- Urea (Selective Noncatalytic Reduction - Urea) capable 

of achieving 51.8 ppm @ 3% oxygen (0.07 lbs/mmBTU) 

Wood Fired SNCR- Urea (Selective Noncatalytic Reduction - Urea) capable 

of achieving 51.8 ppm @ 3% oxygen (0.07 lbs/mmBTU) 

Recovery Furnaces 4th level or air to recovery furnace/good combustion practices or 

equivalent technology capable of achieving 100 ppm @8% oxygen 

Lime Kilns Combustion controls or equivalent technology capable of achieving 

175 ppm @ 10% oxygen 
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Source Type Control Technology and/or Emission Limit 

Fuel Combustion Sources Not 

Otherwise Specified: (Examples 

include but are not limited to 

process heaters not meeting the 

definition of "boiler" in 

Regulation 61-62.1 Section I, 

dryers, furnaces, ovens, duct 

burners, incinerators, and 

smelters)

Low NOx burners or equivalent technology capable of achieving 30% 

reduction from uncontrolled levels. 

SECTION IV - STANDARD REQUIREMENTS FOR EXISTING SOURCES 

(a) For those sources subject to the requirements of this regulation as defined in Section I (a)(2) above 

where an existing burner assembly is replaced after the effective date of this regulation, the burner 

assembly shall be replaced with a low NOx burner assembly or equivalent technology capable of 

achieving a 30 percent reduction from uncontrolled NOx emission levels based upon manufacturer’s 

specifications. An exemption from this requirement shall be granted when a single burner assembly is 

being replaced in a source with multiple burners due to non-routine maintenance. 

(b) For those sources defined in Section I (a)(2) above where an existing burner assembly is replaced 

after the effective date of this regulation, the owner or operator shall notify and register the replacement 

with the Department in accordance with Section V below. 

(c) A facility may request an alternative control methodology to the one specified in paragraph (a) of 

this section provided that they can demonstrate to the Department why the NOx control limits specified 

are not economically or technically feasible for this specific circumstance. The Department reserves the 

right to request that the owner or operator submit additional information as necessary for the alternative 

control methodology determination. Alternative control methodologies granted under this part are not 

effective until notification is submitted to and approved by the Department. 

SECTION V – NOTIFICATION REQUIREMENTS 

(a) Except for those sources that wish to request an alternative control methodology as specified in 

Section IV(c), the notification requirements specified in this section shall apply only to existing sources 

as defined in Section I(a)(2) above where an existing burner assembly is replaced after the effective date 

of this regulation. 

(b) Within 7 days of replacing an existing burner assembly, the owner or operator shall submit written 

notification to register the replacement unit with the Department. 

(c) Notification shall satisfy the permitting requirements consistent with SC Regulation 61-62.1, Section 

II (a). 

(d) Notification shall contain replacement unit information as requested in the format provided by the 

Department. Replacement unit information shall include, at a minimum, all affected units at the source 

and the date the replacement unit(s) will commence operation. 
May 25, 2007 62.5. St. 5.2 - Page 8

(e) Those sources that wish to receive an emission reduction credit for the control device will be 

required to submit a permit application. 

SECTION VI – TUNE-UP REQUIREMENTS 

(a) Owners or operators of a combustion source shall perform tune-ups every two years in accordance 

with manufacturer’s specifications or with good engineering practices. 

(b) All tune-up records are required to be maintained on site and available for inspection by the 

Department for a period of five years from the date generated. 

(c) The facility shall develop and retain a tune-up plan on file. 

R. 61-62.5, Standard No. 5.2 History - State Register: 

Vol. 28, Issue No. 6, (Doc. No. 2872), June 25, 2004. 

 Vol. 31, Issue No. 5, (Doc. No. 3069), May 25, 2007.