SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

Staff Report 

Proposed Rule 1147 – NOx Reductions from Miscellaneous Sources 

December 2008 

Deputy Executive Officer 

Planning, Rule Development, and Area Sources 

Elaine Chang, Dr. PH 

Assistant Deputy Executive Officer 

Planning, Rule Development, and Area Sources 

Laki Tisopulos, Ph.D., P.E. 

Planning and Rules Manager 

Planning, Rule Development, and Area Sources 

Joe Cassmassi 

Author: Wayne Barcikowski – Air Quality Specialist 

 

Reviewed by: Gary Quinn, P.E. – Program Supervisor 

 Linda Vogel – Senior Deputy District Counsel 

 Barbara Baird – District Counsel 
SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

GOVERNING BOARD 

Chairman: WILLIAM A. BURKE, Ed.D. 

Speaker of the Assembly Appointee 

Vice Chairman: S. ROY WILSON, Ed.D. 

Supervisor, Fourth District 

Riverside County Representative 

MEMBERS:

 MICHAEL D. ANTONOVICH 

 Supervisor, Fifth District 

 Los Angeles County Representative 

MICHAEL CACCIOTI

 Council Member, City of South Pasadena 

Cities Representative, Los Angeles County/Eastern Region 

 BILL CAMPBELL 

 Supervisor, Third District 

 Orange County Representative 

 JANE W. CARNEY 

 Senate Rules Committee Appointee 

RONALD O. LOVERIDGE 

 Mayor, City of Riverside 

 Cities Representative, Riverside County 

JOSEPH K. LYOU, PH.D.

Governor’s Appointee 

 GARY C. OVITT 

 Supervisor, Fourth District 

San Bernardino County Representative 

JAN PERRY

 Council Member, City of Los Angeles 

City of Los Angeles 

MIGUEL PULIDO 

 Mayor, City of Santa Ana 

 Cities Representative, County of Orange 

 TONIA REYES URANGA 

 Council Member, City of Long Beach 

 Cities Representative, Los Angeles County/Western Region 

 DENNIS YATES 

 Mayor, City of Chino 

 Cities Representative, San Bernardino County 

EXECUTIVE OFFICER:

BARRY R. WALLERSTEIN, D.Env. 
 i 

 TABLE OF CONTENTS 

TABLE OF CONTENTS i 

EXECUTIVE SUMMARY ES-1 

CHAPTER 1: BACKGROUND 

INTRODUCTION 1-1 

REGULATORY HISTORY 1-1 

EQUIPMENT & PROCESSES 1-2 

TECHNOLOGY ASSESSMENT 1-3 

AFFECTED INDUSTRIES 1-6 

PUBLIC PROCESS 1-6 

CHAPTER 2: SUMMARY OF PROPOSED RULE 1147 

AQMP CONTROL MEASURE 2-1 

PROPOSED RULE REQUIREMENTS 2-1 

CHAPTER 3: IMPACT ASSESSMENT 

IMPACT ANALYSIS 3-1 

COST EFFECTIVENESS 3-2 

CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA) ANALYSIS 3-3 

SOCIOECONOMIC ASSESSMENT 3-3 

DRAFT FINDINGS UNDER CALIFORNIA HEALTH AND SAFETY

 CODE SECTION 40727 3-3

INCREMENTAL COST EFFECTIVENESS 3-4 

COMPARATIVE ANALYSIS 3-4 

REFERENCES R-1 

APPENDIX A: DRAFT PUBLIC COMMENTS AND RESPONSES A-1 
EXECUTIVE SUMMARY 
PR 1147 Staff Report

 ES -1 December 2008 

EXECUTIVE SUMMARY 

Proposed Rule 1147 (PR1147) is designed to reduce NOx emissions from a variety of 

combustion sources. PR1147 is based on two control measures of the 2007 Air Quality 

Management Plan (AQMP): Control Measure CMB-01 and Control Measure MCS-01. 

Control measure CMB-01 (NOx Reductions from Non-RECLAIM Ovens, Dryers, and Furnaces) 

proposes reductions of nitrogen oxides (NOx) from ovens, dryers, kilns, furnaces and other 

equipment and process that are not currently regulated by AQMD Regulation XI – Source 

Specific Standards. Control measure MCS-01 (Facility Modernization) is a new control measure 

developed for the 2007 AQMP that proposes companies upgrade their current technology to the 

cleanest technology available. Facility modernization proposes that equipment operators meet 

best available control technology (BACT) emission limits at the end of the equipment’s useful 

life. For equipment subject to PR1147, modernization would require either burner system 

upgrades or replacement of burner systems. 

PR1147 incorporates the concepts of both control measures. It reduces NOx emissions from the 

combustions sources addressed by CMB-01 and incorporates the concept of facility 

modernization under MCS-01. PR1147 requires equipment meet the NOx emission limit in 

phases based upon equipment age and type. Units older than 25 years must meet the emission 

limit first, followed by units older than 15 years over the next 10 years. 

PR1147 applies to gaseous and liquid fueled combustion equipment including, but not limited to, 

ovens, dryers, dehydrators, heaters, kilns, calciners, furnaces, crematories, incinerators, heated 

pots, cookers, roasters, fryers, closed and open heated tanks and evaporators, distillation units, 

afterburners, degassing units, vapor incinerators, catalytic or thermal oxidizers, and remediation 

units. This proposed rule does not apply to solid fuel fired combustion equipment, internal 

combustion engines regulated under District Rule 1110.2, turbines, charbroilers, or boilers, water 

heaters, thermal fluid heaters or enclosed process heaters subject to District Rules 1109, 1146, 

1146.1, or 1146.2. In addition, PR1147 does not apply to equipment subject to AQMD Rules 

1111, 1112, 1117, 1118, 1121, or 1135. The rule also exempts specific processes used in some 

flares, vapor incinerators and catalytic and thermal oxidizers. 

PR1147 requires equipment to meet NOx emission limits in the range of 30 ppm to 60 ppm 

(referenced to 3% oxygen) depending upon the process and process temperature. The emission 

limits in PR1147 can be achieved with low NOx burners. The emission limits are based on 

AQMD and other air district’s determinations for BACT, availability of burners that can achieve 

these emission levels and recent emission limits decisions for AQMD permits. Currently, the 

typical emission for low NOx burners applicable to equipment subject to PR1147 varies from 

less than 20 ppm to 60 ppm depending upon the burner, process temperature and nature of the 

process. There are a large variety of burners that emit less than 30 ppm NOx for the majority of 

units whose process temperatures are less than 1200° F. A number of manufacturers provide 

burners meeting the proposed NOx limits for equipment regulated by the proposed rule. 
PR 1147 Staff Report

 ES -2 December 2008 

PR1147 also requires operators to keep equipment maintenance records and to install meters for 

monitoring fuel use starting January 1, 2011. Maintenance records must be kept on site by 

facilities for at least three years. Newer units are currently required to have fuel or time meters 

by their permit conditions. PR1147 will place the same requirement on older equipment but 

allow time for installation. PR1147 also provides owners of facilities with five or more units 

with emissions greater than one pound per day an alternative compliance option to retrofit 

equipment over a longer period of time. 

PR1147 provides two options for owners and operators, burner manufacturers and installers to 

provide evidence the replacement burners comply with the emission limit. One option is to 

source test the unit using an AQMD approved protocol and test method. The second option is 

for the manufacturer to certify burners and equipment using an AQMD approved protocol and 

test method. The AQMD would provide certification of specific combinations of burners and 

equipment to the manufacturer and a copy of that certification, provided by the manufacturer, 

would be required to be kept on-site by the owner/operator. The AQMD will monitor 

manufacturers, sellers and installers in addition to owner and operators to assure that certified 

installations comply with PR1147 emission limits. 

The approximately 6,600 units subject to the emission limits of PR1147 are located at 

approximately 3,000 facilities. However, only about 2,200 facilities are expected to require 

retrofit of burners in their equipment. Staff estimates that as many as 2,500 permitted units with 

NOx emission limits greater than one pound per day must retrofit to meet the emission limits of 

PR1147 between 2010 and 2014. An additional 2,500 permitted units with NOx emission limits 

of less than one pound per day will become subject to the emission limits of the proposed rule 

between 2015 and 2019. About 1,600 additional units at about 800 facilities affected by PR1147 

currently meet the NOx emission limits of PR1147. Of the approximately 5,000 units that 

currently do not meet the emission limits, at least 100 relocated or replacement soil and water 

remediation units per year will become subject to the NOx emission limit starting in 2011, and 

all units will meet the NOx emission limit by 2023. 

The proposed rule is estimated to reduce annual average emissions of NOx by 3.5 tons per day in 

2014 from an annual average inventory of 6.2 tons per day. Phasing-in equipment with emission 

limits less than one pound per day starting in 2015 will reduce emissions an additional 0.3 tons 

per day by 2023. 

Rule cost effectiveness is based on replacement of burners. Replacement cost includes burner 

price, tax and installation. The cost effectiveness for burners meeting 30 ppm is about $5,000 

per ton of NOx reduced. The average cost effectiveness for burners meeting 40 or 60 ppm is 

about $7,000 per ton. The cost effectiveness for commonly used 1 to 2 mmBtu/hour burners 

meeting 30 ppm varies widely from $4,000 to $13,000 per ton. 

. 
 

CHAPTER 1: BACKGROUND 

INTRODUCTION 

REGULATORY HISTORY 

EQUIPMENT AND PROCESSES 

TECHNOLOGY ASSESSMENT 

AFFECTED INDUSTRIES 

PUBLIC PROCESS 
PR 1147 Staff Report

 1 - 1 December 2008 

INTRODUCTION 

The purpose of Proposed Rule 1147 (PR1147) is to reduce emissions of nitrogen oxides (NOx) 

from gaseous and liquid fuel fired combustion equipment. The proposed rule will regulate 

equipment that is not specifically addressed in AQMD Regulation XI – Source Specific 

Standards. The equipment addressed by PR1147 is used in a variety of industrial applications. 

REGULATORY HISTORY 

PR1147 is based on two control measures from the South Coast Air Quality Management 

District (AQMD) 2007 Air Quality Management Plan (AQMP): Control measure CMB-01 

(NOx Reductions from Non-RECLAIM Ovens, Dryers, and Furnaces) and control measure 

MCS-01 (Facility Modernization). Emission reductions from the equipment addressed by 

PR1147 and control measure CMB-01 of the 2007 AQMP were proposed in prior AQMPs (e.g., 

control measure 97CMB-092 from the 1997 AQMP). 

Control measure MCS-01 is a new control measure developed for the 2007 AQMP that proposes 

companies upgrade their current technology to the cleanest technology available. Facility 

modernization proposes that equipment operators meet best available control technology 

(BACT) emission limits at the end of the equipment’s useful life. For equipment regulated by 

PR1147, modernization would require either burner upgrades or replacement of burner systems. 

Equipment that will be regulated by PR1147 must currently meet the requirements of AQMD 

Regulation XIII – New Source Review (NSR) and AQMD Regulation IV – Prohibitions. 

Equipment subject to NSR must meet BACT requirements and offset emission increases. The 

AQMD’s NSR program includes pre-construction permit review requirements for equipment and 

processes subject to permit requirements. Permit applications subject to NSR are required to 

utilize BACT for installation of new equipment, relocation of existing permitted equipment, or 

modification of existing permitted equipment when the modification results in an emissions 

increase. BACT is defined as the most stringent emission limitation or control technique that: 

has been achieved in practice, is contained in any state implementation plan (SIP) approved by 

EPA, or is any other emission limitation or control technique found by the Executive Officer to 

be technologically feasible and is cost-effective as compared to adopted rules or measured listed 

in the AQMP. 

Regulation IV limits emissions of particulate matter and NOx from combustion sources. 

However, NOx emission limits required by BACT are significantly more stringent than the 

emission limits in Regulation IV. For example, Rule 474 – Fuel Burning equipment – Oxides of 

Nitrogen has emission limits that vary from 125 ppm to 400 ppm (referenced to 3% oxygen) 

depending upon the fuel and heat input rating of the equipment. BACT NOx emission limits for 

combustion equipment subject to PR1147 vary from 60 ppm to 30 ppm (referenced to 3% 

oxygen). 

Other AQMD regulations affecting equipment addressed by PR1147 are Regulation IX – 

Standards of Performance for New Stationary Sources (NSPS) and Regulation XXX – Title V 
PR 1147 Staff Report

 1 - 2 December 2008 

Permits. Regulation IX is a compilation of federal regulations specifying standards of 

performance and emission guidelines for new and modified sources. Regulation XXX specifies 

permit application and issuance procedures and compliance requirements mandated by the 

federal Operating Permit Program in Title V of the federal Clean Air Act. 

Some of the equipment that will be regulated under PR1147 may also be subject to AQMD 

Regulation X – National Emission Standards for Hazardous Air Pollutants and Regulation XIV – 

Toxics. Regulation X is a compilation of federal performance standards for handling hazardous 

materials. Regulation XIV includes 15 AQMD Rules that address emissions of toxic air 

contaminants. 

Equipment subject to NOx emission limits by rules in AQMD Regulation XI – Source Specific 

Standards are not proposed to be regulated under PR1147. Changes to NOx emission limits for 

equipment subject to Regulation XI will be addressed through amendment of those source 

specific rules. 

EQUIPMENT AND PROCESSES 

Proposed Rule 1147 applies to combustion equipment including, but not limited to, ovens, 

dryers, dehydrators, heaters, kilns, calciners, furnaces, crematories, incinerators, heated pots, 

cookers, roasters, fryers, closed and open heated tanks and evaporators, distillation units, 

afterburners, degassing units, vapor incinerators, catalytic or thermal oxidizers, and remediation 

units. This proposed rule does not apply to solid fuel fired combustion equipment, internal 

combustion engines regulated under District Rule 1110.2, turbines, charbroilers, or boilers, water 

heaters, thermal fluid heaters or enclosed process heaters subject to District Rules 1109, 1146, 

1146.1, or 1146.2. In addition, PR1147 does not apply to equipment subject to AQMD Rules 

1111, 1112, 1117, 1118, 1121, or 1135. 

A wide variety of processes use equipment that will be regulated under PR1147. These 

processes include, but are not limited to, food products preparation, printing, textile processing, 

product coating; and material processing. A large fraction of the equipment subject to PR1147 

heats air that is then directed to a process chamber and transfers heat to process materials. This 

is a form of convective heat transfer. 

Convective heat transfer involves transfer of energy from a moving fluid (i.e., heated air and 

combustion gasses) to solid or liquid process materials. Dryers, dehydrators and many ovens 

heat air to dry or raise the temperature of process materials. Furnaces, kilns and other types of 

ovens use a more direct form of convective heat transfer as the primary means of raising process 

materials’ temperature. In these processes, heat is transferred directly from exhaust gasses to 

process materials. 

Some ovens, furnaces and kilns also use radiant heat transfer to raise the temperature of process 

materials. Radiant heat transfer, or thermal radiation, is the transfer of energy by 

electromagnetic radiation in the infrared and visible light wavelengths. The amount of thermal 

radiation emitted by an object depends upon its temperature. Equipment generating radiant heat 

use specialized burners that transfer a larger amount of the energy from combustion to process 
PR 1147 Staff Report

 1 - 3 December 2008 

materials through thermal radiation. These types of equipment can also generate radiant heat 

using electric elements instead of combustion. 

It is important to note that all burners produce radiant heat from the temperature of the flame and 

the high temperature of exhaust gasses. Ovens, furnaces and kilns are designed to capture 

convective heat from exhaust gasses through the use of heat tolerant metal and refractory 

material in the process chamber and then transfer heat to process materials by thermal radiation. 

This also helps make the temperature in the unit uniform. 

TECHNOLOGY ASSESSMENT 

There are several options for reducing NOx emissions from combustion equipment subject to 

PR1147. Some processes may be able change their process so heat is generated by electricity. 

Many processes use equipment that generates heat from electricity. Other processes may be able 

to use heat generated by a boiler or thermal fluid heater. Heat transfer from steam or thermal 

fluids can be an efficient and cost effective way to heat a process. However, both of these other 

options require the use of an exchange system to heat the process chamber or air that heats the 

product. For the majority of processes however, the preferred option to reduce NOx emissions 

will be upgrading or replacing the burner system. 

Low NOx Burner Technology 

Low NOx burners in some applications can achieve less than 10 ppm NOx (referenced to 3% 

oxygen). There are many types of burners that emit less than 30 ppm NOx. The manufacturers 

of these products use a variety of techniques to achieve lower emissions. The principle 

technique involves premixing of fuel and air before combustion takes place. This results in a 

lower and more uniform flame temperature. A lower flame temperature with fewer hot spots 

reduces formation of NOx. 

Most premix burners require the aid of a blower to mix the fuel with air before combustion takes 

place (primary air). However, tank type water heaters and some small boilers are now made 

with atmospheric premix burners that achieve NOx emissions less than 15 ppm. Atmospheric 

burners do not use a blower to mix fuel and air. Premixing of fuel and air is accomplished using 

a jet of fuel gas exiting specially designed nozzle. The velocity of the fuel leaving the nozzle 

draws in air and mixing is completed in the body of the burner before the fuel and air mixture 

leaves the burner. Premixing of combustion air with fuel can also help keep the temperature 

uniform in an oven, furnace, etc. 

To further reduce NOx emissions, some premix burners also use staged combustion. This 

technique produces two combustion zones with differing air-fuel mixtures. The burner produces 

a fuel rich zone to start combustion and stabilize the flame and a fuel lean zone to complete 

combustion and reduce the peak flame temperature. In combination, these two zones reduce the 

formation of NOx. This technique incorporated premixing and can be used in combination with 

other techniques 

Some burners incorporate flue gas recirculation (FGR) to further reduce NOx emissions. FGR 

involves mixing a small amount of exhaust gasses with the combustion air that is mixed with 
PR 1147 Staff Report

 1 - 4 December 2008 

fuel. Newer burners are designed to induce an internal FGR within the burner and the 

combustion chamber. This eliminates the need for external piping and an additional blower to 

bring the flue gasses to the burner. 

Burners can also be designed to spread flames over a larger surface area to reduce hot spots and 

lower NOx emissions. Radiant premix burners with ceramic, sintered metal, metal screen or 

metal fiber heads spread the flame and produce more radiant heat. When a burner produces 

more radiant heat, it results in less heat escaping the equipment through exhaust gasses. 

Another common technique used to lower NOx emissions is increasing the amount of extra 

primary combustion air mixed with the fuel prior to combustion (increasing the excess air). 

Increasing the excess air reduces flame temperature and NOx emissions, but it also reduces the 

temperature of combustion gasses through dilution. This reduction in flue gas temperature can 

reduce process efficiency if no other adjustments are made. However, a large percentage of the 

equipment regulated by PR1147 is used to heat process air or simply heats a chamber (ovens, 

dryers, heaters and furnaces). Many processes can be adjusted to compensate for higher levels 

of excess air in the burner with no loss in efficiency or increase in fuel consumption. Excess air 

through burners can also help maintain a more uniform temperature and reduce temperature 

stratification in a unit. 

Low NOx burners typically incorporate several of the previously discussed technologies. The 

NOx reduction technologies incorporated into the burner and the extent utilized depend upon the 

applications for which the burner is designed. 

Emissions and Availability of Low NOx Burners 

PR1147 requires equipment to meet NOx emission limits in the range of 30 ppm to 60 ppm 

(referenced to 3% oxygen) depending upon the process and process temperature. The emission 

limits are based on AQMD and other air district’s determinations for BACT, availability of 

burners that can achieve these emission levels and recent emission limits decisions for AQMD 

permits. Currently, the typical emission for low NOx burners applicable to equipment subject to 

PR1147 varies from less than 20 ppm to 60 ppm depending upon the burner, process temperature 

and nature of the process. 

BACT determinations by the AQMD and other air districts since 1998 have resulted in emission 

limits of 30 to 60 ppm for equipment ranging from low temperature ovens to very high 

temperature metal melting and heat treating furnaces. A review of the BACT decisions made by 

California air districts identifies two decisions on asphalt manufacturing between 40 and 30 ppm, 

eight of nine decisions on ovens, dryers, printing heat set and drying and low temperature 

furnaces at 30 ppm or lower, and five decisions on metal melting and heat treating between 39 

and 60 ppm. The higher limit of 60 ppm was for a furnace operating with preheated air which 

increases NOx emission concentrations but significantly increases efficiency, which reduces fuel 

use and results in less NOx. 

Currently a variety of manufacturers provide burners meeting the proposed NOx limits for the 

equipment regulated by the proposed rule. There are at least seven models of burner from the 

two major suppliers (i.e., Eclipse and Maxon) of burners for low temperature processes meeting 
PR 1147 Staff Report

 1 - 5 December 2008 

30 ppm for air heating, ovens and low temperature furnace applications. There are at least six 

models of burners from the same two manufacturers that can achieve 30 to 60 ppm in kiln, 

afterburner or higher temperature furnace applications. Other manufacturers (e.g., Astec, Hauck 

and North American) produce burners for asphalt and furnace applications. Burners from all of 

these manufacturers have been used as the basis for AQMD and other air district BACT 

determinations. 

Fuel Efficiency 

Most units requiring a burner replacement to meet the emission limit of PR1147 currently have 

burners with emissions of 110 to 170 ppm or more. Replacement of many of these older high 

emitting burner with new low NOx 30 ppm burner’s will improve process efficiency because 

new burners are more fuel efficient. Improved combustion and process efficiency will also result 

in lower emissions of carbon dioxide. Replacement of 60 to 90 ppm burners with low NOx 

burners with 30 ppm burners may result in small efficiency gains. 

Burner Turndown 

Technical consultants working with businesses that use equipment subject to PR1147 have raised 

a concern about reduced turndown for low NO burners. Turndown is the ratio of the maximum 

firing rate to the minimum firing rate and is a way to represent a burner’s heat output range. 

Some operations require process temperature to be maintained within a small range and a burner 

with a high turndown is typically used to maintain the temperature within that small range. 

Many standard burners can achieve a turndown ratio of greater than 30:1. However, the NOx 

emission rate for these burners is typically greater than 90 ppm (referenced to 3% oxygen) 

according to burner manufacturers. 

The available turndown for any burner depends upon a variety of factors including process 

operations, emission limit to be achieved, and burner control system. Available low NOx 

burners for processes affected by PR1147 have significantly higher turndown than equivalent 

burners for boilers. A typical low NOx burner for a boiler has a turndown of 4:1. For PR1147 

equipment, current low NOx burners with NOx emissions between 20 to 40 ppm (3% oxygen) 

have a turndown in the range of 15:1 to 10:1. However, there are low NOx burners with 

turndown of 25:1 or greater. 

In many cases a large burner with a high turndown is used to start up a process quickly. After 

the equipment is brought up to the process operating temperature, the burner then fires up to 50 

to 60% capacity. A large burner with high turndown is important in cold climates when the 

burner needs to be oversized in order to quickly heat up equipment. However, in Southern 

California an oversized burner is not essential because the climate is moderate. The equipment 

can be quickly brought up to operating temperature with a smaller burner. 

When equipment with an oversized burner is in production mode and the burner operates at 60% 

capacity or less, the effective turndown for the process is about 15 percent. This is the reason 

why equipment that traditionally use burners with a turndown of 30:1 can meet today’s BACT 

limits (20 to 40 ppm) using low NOx burners with turndowns of 15:1 or less. There may even be 

an efficiency benefit in switching to a smaller burner. Burners are typically more efficient when 

they operate closer to their maximum rated capacity. 
PR 1147 Staff Report

 1 - 6 December 2008 

AFFECTED INDUSTRIES 

Proposed Rule 1147 affects manufacturers (NAICS 33), distributors and wholesalers (NAICS 

42) of combustion equipment, as well as owners and operators of ovens, dryers, furnaces, and 

other equipment in the district (NAICS 21, 23, 31-33, 42, 44, 45, 48, 49, 51-56, 61, 62, 71, 72, 

81, and 92). The units affected by the proposed rule are used in industrial, commercial and 

institutional settings for a wide variety of processes. 

The approximately 6,600 units subject to the emission limits of PR1147 are located at 

approximately 3,000 facilities. However, only about 2,200 facilities are expected to require 

retrofit of burners in their equipment. Staff estimates that as many as 2,500 permitted units with 

NOx emission limits greater than one pound per day must retrofit to meet the emission limits of 

PR1147 between 2010 and 2014. An additional 2,500 permitted units with NOx emission limits 

of less than one pound per day will become subject to the emission limits of the proposed rule 

between 2015 and 2019. About 1,600 additional units at about 800 facilities affected by PR1147 

currently meet the NOx emission limits of PR1147. Of the approximately 5,000 units that 

currently do not meet the emission limits, at least 100 relocated or replacement soil and water 

remediation units per year will become subject to the NOx emission limit starting in 2011, and 

all units will meet the NOx emission limit by 2023. 

PUBLIC PROCESS 

The rule development effort for Rule 1147 is part of an ongoing process to assess low NOx

technologies for combustion equipment. For this rule development, staff held three four Task 

Force meetings on process and burner technologies with representatives from affected 

businesses, manufacturers, trade organizations and other interested parties. At these meetings 

low NOx technology, emission limits, emission testing and compliance dates were discussed. 

Staff also held individual meetings with manufacturers and distributors of burner systems and 

visited local businesses to observe processes and equipment affected by PR1147. In addition, 

staff held a Public Workshop on September 30, 2008 and a Public Consultation Meeting on 

October 28, 2008. 
CHAPTER 2: SUMMARY OF PROPOSED RULE 1147 

AQMP CONTROL MEASURE 

PROPOSED RULE REQUIREMENTS 
PR 1147 Staff Report

 2 - 1 December 2008 

AQMP CONTROL MEASURE 

Control measure CMB-01 – NOx Reductions from Non-RECLAIM Ovens, Dryers, and Furnaces 

and control measure MCS-01 – Facility Modernization provide a framework for PR1147. 

Control measure MCS-01 proposes that equipment operators meet best available control 

technology (BACT) emission limits at the end of the equipment’s useful life. Control measure 

CMB-01 proposes emission NOx limits in the range of 20 ppm to 60 ppm (referenced to 3% 

oxygen) for ovens, dryers, kilns, furnaces and other miscellaneous combustion equipment. 

BACT limits for equipment regulated by PR1147 are in the range of emission limits proposed in 

control measure CMB-01. To meet these emission limits, equipment will require burner 

replacement or upgrades to burner control systems. 

PROPOSED RULE REQUIREMENTS 

Purpose and Applicability 

Rule 1147 will reduce NOx emissions from a large variety of equipment and processes. 

Proposed Rule 1147 applies to equipment and processes that are required to have an AQMD 

permit to operate but whose NOx emissions are not regulated by AQMD regulation XI. The 

equipment regulated by PR1147 include, but are not limited to, ovens, dryers, dehydrators, 

heaters, kilns, calciners, furnaces, crematories, incinerators, heated pots, cookers, roasters, 

fryers, closed and open heated process tanks and evaporators, distillation units, afterburners, 

degassing units, vapor incinerators, catalytic or thermal oxidizers, and remediation units. This 

proposed rule does not apply to solid fuel fired combustion equipment, internal combustion 

engines regulated under District Rule 1110.2, turbines, charbroilers, or boilers, water heaters, 

thermal fluid heaters or process heaters subject to District Rules 1109, 1146, 1146.1, or 1146.2. 

In addition, PR1147 does not apply to equipment subject to AQMD Rules 1111, 1112, 1117, 

1118, 1121, or 1135. 

Requirements 

PR1147 requires new, modified, relocated and in-use combustion equipment subject to the rule 

to comply with the equipment specific NOx emission limits listed in Table 1. In addition to 

limits for specific equipment, PR1147 also includes limits based on process temperature. The 

proposed emission limits are based on AQMD BACT determinations, recent AQMD permit 

applications and associated sources tests, and discussions with burner manufacturers and 

vendors. Other criteria considered by AQMD staff in selection of the proposed NOx limits 

include cost effectiveness and availability of burners from multiple manufacturers. 

Table 1 combines equipment based on process characteristics and lists the proposed NOx 

emission limits. Table 1 also includes NOx emission limits for unspecified equipment based on 

process temperature. Higher process temperatures result in higher NOx emissions and this is 

reflected in the limits in Table 1. 
PR 1147 Staff Report

 2 - 2 December 2008 

Table 1 – NOx Emission Limit 

NOx Emission Limit 

Equipment Category(ies) PPM @ 3% O2, dry or Pound/mmBtu heat input

Process Temperature 

Gaseous Fuel-Fired Equipment ≤ 800° F

> 800 ° F and 

< 1200° F ≥ 1200 ° F

Asphalt Manufacturing Operation 40 ppm 40 ppm 

Afterburner, Degassing Unit, Remediation Unit, 

Thermal Oxidizer, Catalytic Oxidizer or Vapor 

Incinerator 1

30 ppm or 0.036 

lb/mmBtu 

60 ppm or 

0.073 lb/mmBtu 

60 ppm or 0.073 

lb/mmBtu 

Evaporator, Fryer, Heated Process Tank, or Parts 

Washer 

60 ppm or 0.073 

lb/mmBtu 

60 ppm or 

0.073 lb/mmBtu 

Metal Heat Treating, Metal Melting Furnace, 

Metal Pot, or Tar Pot 

60 ppm or 0.073 

lb/mmBtu

60 ppm or 

0.073 lb/mmBtu

60 ppm or 0.073 

lb/mmBtu

Oven, Dehydrator, Dryer, Heater, Kiln, 

Crematory, Incinerator, Calciner, Cooker, 

Roaster, Furnace, or Heated Storage Tank 

30 ppm or 0.036 

lb/mmBtu 

30 ppm or 

0.036 lb/mmBtu 

60 ppm or 0.073 

lb/mmBtu 

Make-Up Air Heater or other Air Heater located 

outside of building with temperature controlled 

zone inside building 

30 ppm or 0.036 

lb/mmBtu 

Tenter Frame or Fabric or Carpet Dryer 30 ppm or 0.036 

lb/mmBtu 

Other Unit or Process Temperature 30 ppm or 0.036 

lb/mmBtu 

30 ppm or 

0.036 lb/mmBtu 

60 ppm or 0.073 

lb/mmBtu 

Liquid Fuel-Fired Equipment ≤ 800° F

> 800 ° F and 

< 1200° F ≥ 1200 ° F

All liquid fuel-fired Units 40 ppm or 0.053 

lb/mmBtu 

40 ppm or 

0.053 lb/mmBtu 

60 ppm or 0.080 

lb/mmBtu 

1 Emission limit applies to burners in units fueled by 100% natural gas that are used to incinerate air toxics, 

VOCs, or other vapors; or to heat a unit. The emission limit applies solely when burning 100% fuel and not 

when the burner is incinerating air toxics, VOCs, or other vapors. The unit shall be tested or certified to 

meet the emission limit while fueled with natural gas. 

Compliance dates for in-use equipment to meet NOx emission limits are listed in Table 2. 

Compliance is phased in for equipment based on age starting July 1, 2010. Initially, equipment 

that is at least 25 years old must meet the emission limit, followed a year later by equipment that 

is 20 to 25 years old and then equipment that is 15 years old. The exception is remediation 

equipment which must comply on or after January 1, 2011 when a combustion modification or 

change of location occurs or when a new unit begins operating. The compliance schedule for 

degassing equipment, evaporators, incinerators, heated tanks and spray booth make-up air 

heaters differs in order to allow manufacturers additional time to certify equipment and develop 

a greater number of compliant products. Tar pots must comply after January 1, 2012 when 

submitting a permit application for a new unit or change of ownership. Other In-use equipment 

must comply with the PR1147 emission limit starting January 1, 2013 and when the equipment is 

15 years old. 
PR 1147 Staff Report

 2 - 3 December 2008 

Table 2 – Compliance Schedule for In-Use Units 

Equipment Category(ies) Compliance Date 

Remediation UNIT 

Upon combustion modification or change of 

location for units manufactured prior to 1998 

Beginning January 1, 2011 

Tar Pot 

Permit Application for Change of Ownership or 

New Equipment 

Beginning January 1, 2012 

Afterburner, degassing unit, catalytic oxidizer, 

thermal oxidizer, vapor incinerator, evaporator, 

food oven, fryer, heated process tank, parts 

washer or spray booth make-up air heater 

manufactured prior to 1998 

July 1, 2013 

Other UNIT manufactured prior to 1986 July 1, 2010 

Other UNIT manufactured prior to 1992 July 1, 2011 

Other UNIT manufactured prior to 1998 July 1, 2012 

Any UNIT manufactured after 1997 July 1 of the year the unit is 15 years old 

PR1147 provides owners of facilities with five or more units with emissions greater than one 

pound per day an alternative compliance option to modify equipment over a longer period of 

time. Owners or operators of facilities with five or more in-use units with permit emission limits 

greater than one pound per day NOx that will require burner modifications may submit an 

alternate compliance plan by July 1, 2009 to phase-in compliance of all units starting January 1, 

2010 and ending before January 1, 2015. At least one unit shall be modified to comply with the 

applicable emission limit of this rule by January 1, 2010. Each year thereafter, up to a maximum 

of four years, a minimum of 20 percent of additional units shall comply with the applicable 

emission limit. All units must comply with the applicable emission limit of this rule by January 

1, 2015. PR1147 also provides additional time for specific categories of equipment that has 

recently replaced burners or has a permit limit of less than one pound per day NOx at the time of 

rule adoption. 

• Units with 75% or more of the burner capacity replaced before adoption of the 

rule have an additional ten years from the date of the burner modification to meet 

the emission limit. 

• Units with emissions of one pound per day or less have five additional years to 

comply with the emission limit. 

Additional requirements include keeping records of maintenance and combustion modifications 

and installation of meters to monitor fuel and equipment use. The recordkeeping requirements 

start January 1, 2010 and a requirement for gas and time meters starts January 1, 2011. 

PR1147 also requires units whose process operates at oxygen levels of more than 18% to use a 

pre-approved source testing protocol. For processes operating at high oxygen and low carbon 

dioxide concentrations, the standard techniques for converting NOx concentration levels to a 3% 

oxygen reference level are not appropriate. One alternative is to comply with the pound per 
PR 1147 Staff Report

 2 - 4 December 2008 

million Btu emission limit. AQMD staff will consider alternatives submitted for review in test 

protocols. 

Compliance Determination, Certification and Enforcement 

PR1147 also identifies test methods for determining compliance with rule requirements and 

establishes a framework for manufacturers wanting to certify the emission level of their 

products. Among the list of approved test methods, two rely on portable analyzers and one 

method allows compliance determination with the lb/mmBtu emission limit option. Emissions 

testing using the lb/mmBtu option is one alternative for evaluating emissions from processes that 

operate at high oxygen concentrations (more than 18%). Copies of source test results and 

certifications must be kept on site by the operators of affected units and made available to the 

AQMD upon request. The AQMD will inspect distributors, retailers and installers as well as 

operators and conduct tests as necessary to ensure compliance of affected units.

Instead of requiring owners and operators of affected units to re-test each unit after a number of 

years, staff is proposing to implement a testing program where the District randomly tests a 

statistically significant sample of units annually to determine the state of compliance with the 

emission limits. This testing program could be implemented starting in 2012 after half of the 

equipment have replaced burners and completed their initial source tests and manufacturers have 

certified equipment.

The testing program would be funded by assessing a fee to all facility operators with equipment 

affected by PR1147. These funds would offset the costs incurred by the AQMD in conducting 

the testing program. Sample sizes and unit selection will be based upon standard sampling and 

statistical techniques. The cost to fund the testing program would be up to $100 per unit 

per year. A typical cost for a source test is about $1,200 per test. Staff will evaluate 

billing options and develop a proposal for consideration by the Board when amending 

Regulation III. 

Exemptions 

Exemptions are provided for equipment and processes at RECLAIM facilities and that are 

regulated by other AQMD source specific rules in Regulation XI. An exemption is also 

provided for flare, afterburner, degassing unit, remediation unit, thermal oxidizer, catalytic 

oxidizer and vapor incinerator processes in which a fuel, including but not limited to natural gas, 

propane, butane or liquefied petroleum gases, is mixed with air toxics, VOCs or other 

combustible vapors prior to incineration in the unit in order to start-up or maintain combustion or 

temperature in the unit. This exemption does not apply to a burner with a separate fuel line used 

to heat up or maintain temperature of a unit or incinerate air toxics, VOCs or other combustible 

vapors in a gas stream moving past the burner flame. 

An exemption is also provided for flares, afterburners, degassing units, thermal oxidizers or 

vapor incinerators in which a fuel; including but not limited to natural gas, propane, butane or 

liquefied petroleum gases; is only used to maintain a pilot for vapor ignition. PR1147 also 

exempts solid fuel-fired units and provides an exemption for existing afterburners incorporating 

a heat exchanger that captures heat from an oven or furnace. 
PR 1147 Staff Report

 2 - 5 December 2008 

PR1147 in addition provides a temporary exemption from the NOx emission limit for new 

afterburners, degassing units, thermal oxidizers, catalytic oxidizers, vapor incinerators, and spray 

booth make-up air heaters installed after adoption of PR1147 and before January 1, 2011. New 

food ovens, fryers, heated process tanks, parts washers, and evaporators installed after date of 

adoption and before January 1, 2013 are also exempt from the emission limit in Table 1 at the 

time of installation. These two categories of units must comply with the NOx emission limit on 

or before July 1 of the year the unit becomes 15 years old. New and relocated remediation units 

installed before January 1, 2011 are exempt until the unit is moved or a combustion modification 

is made. 
 

CHAPTER 3: IMPACT ASSESSMENT 

IMPACT ANALYSIS 

COST EFFECTIVENESS 

CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA) ANALYSIS 

SOCIOECONOMIC ASSESSMENT 

DRAFT FINDINGS UNDER CALIFORNIA HEALTH & SAFETY CODE

SECTION 40727

INCREMENTAL COST-EFFECTIVENESS 

COMPARATIVE ANALYSIS 
PR 1147 Staff Report

 3 - 1 December 2008 

IMPACT ANALYSIS 

The proposed rule is estimated to reduce annual average emissions of NOx by 3.5 ton per day by 

2014 (56%) and 3.8 tons per day by 2023. Emission reductions are estimated based on a survey 

of equipment permits for units subject to PR1147. Overall, about 25% of the equipment subject 

to the rule is estimated to meet the proposed emission limits in PR1147. Many current BACT 

limits were put in place between 1998 and 2003. For some equipment categories the percentage 

meeting BACT emission limits is higher than 25% (e.g., ovens, dryers and furnaces less than 

1200 ° F which account for about half of the units subject to PR1147). For other categories (e.g., 

high temperature furnaces, heated tanks, afterburners and remediation units) the fraction meeting 

PR1147 limits is lower. The average emission reduction per unit is about 75%. An average 

reduction of 75% from three fourths of the emission inventory results in a reduction of 56%. 

Emission reductions are spread over a variety of industrial, commercial and institutional 

operations and are anticipated to be proportional for each process category in the current 

inventory. Figure 1 provides an estimate of the percentage of NOx emissions in the current 

inventory associated with various process categories. 

Figure 1 – NOx Emission Contribution from Processes Subject to PR1147 

Food Oven, 3%

Fryer, 2%

Heat Treat, 6%

Kiln, 2%

Incinerator, 1%

Metal Furnace, 

7%

Misc, 1%

Printing Dryer, 

5%

Afterburner, Vapor 

Incinerator, 

Remediation, etc.

12%

Tank/Pot, 2% Asphalt, 7%

Burn-Off 

Oven/Furnace, 

3%

Cook/Cure/React 

Oven/Furnace, 

25%

Crematory, 3%

Drying, 22%
PR 1147 Staff Report

 3 - 2 December 2008 

COST EFFECTIVENESS 

A cost effectiveness for installing new low NOx burners in equipment affected by PR1147 was 

estimated by 2007 AQMP Control Measures CMB-01 and MCS-01. The range of cost 

effectiveness was $4,000 to $17,000 per ton. This estimate was based on a number of previous 

analyses including the 2005 amendment to the AQMD RECLAIM program which includes large 

operations with ovens, dryers, furnaces and kilns. 

Other examples of low NOx burner cost effectiveness for equipment with smaller burners are 

also available. For example, in the analysis for the May 2006 amendment to AQMD Rule 

1146.2 – Emissions of Oxides of Nitrogen from Large Water Heaters and Small Boilers and 

Process Heaters, the cost effectiveness for meeting a 20 ppm NOx limit was $2,400 to $16,000 

per ton. In the analysis for the amendment to Rule 1121, the cost effectiveness for smaller tank 

type water heaters to meet a 30 ppm and 15 ppm limit respectively was estimated to be $4,000 

and $16,000 per ton. 

A new cost effectiveness analysis has been prepared for equipment affected by PR1147. 

Technical information and costs were provided by burner manufacturers. The cost effectiveness 

estimates include burner cost, tax and installation. Installation cost is assumed to be 50% of the 

equipment cost based on EPA guidelines. Emission reductions are calculated assuming an 

average capacity factor of 20%. The capacity factor is used to represent the annual heat output 

and emissions of a burner relative to the theoretical annual maximum. A 20% capacity is 

conservative and much equipment subject to PR1147 would have significantly higher usage. For 

burners less than 500,000 Btu/hr the baseline emission is assumed to be 0.134 lb/mmBtu (110 

ppm). For larger burners the baseline emission is assumed to be 0.109 lb/mmBtu (90 ppm). In 

many cases, emissions are higher than the baseline assumed. However, these baseline emission 

estimates are conservative and appropriate because some units have lower emissions. 

Cost effectiveness was estimated for achieving 60 ppm, 40 ppm, and 30 ppm in PR1147 

equipment. The average cost effectiveness for 30 ppm, 40 ppm and 60 ppm was $5,000, $7,000 

and $7,000 per ton respectively. The cost effectiveness for frequently used 1 to 2 mmBtu/hour 

burners meeting 30 ppm varies from $4,000 to $13,000 per ton. The average cost effectiveness 

for specific size categories of 30 and 60 ppm burners is presented in Table 3. Table 4 provides a 

summary of average cost for burners meeting 30 and 60 ppm. 

Table 3 – Burner Cost Effectiveness 

Burner Size 

(mmBtu/hr) 30 ppm 60 ppm 

Less than 0.5 $19,700 $17,000 

1 $6,000 $6,000 

2.5 $4,000 $5,000 

5 $3,000 $4,500 

10 $2,800 $4,000 

20 $2,700 $3,000 
PR 1147 Staff Report

 3 - 3 December 2008 

Table 4 – Average Burner Cost 

Burner Size 

(mmBtu/hr) 30 ppm 60 ppm 

Less than 0.5 $6,800 $2,500 

1 $3,500 $2,000 

2.5 $5,500 $3.500 

5 $5,000 $5,000 

10 $10,000 $8,000 

20 $23,000 $22,000 

CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA) ANALYSIS 

Pursuant to the California Environmental Quality Act (CEQA) and AQMD Rule 110, an 

Environmental Assessment (EA) was prepared for Proposed Rule 1147 and was circulated for a 

30 day public review from October 16, 2008 to November 14, 2008. Responses to any 

comments on the Draft EA received during the public review and comment period will be 

prepared and incorporated into the Final EA.

Pursuant to the California Environmental Quality Act (CEQA) and AQMD Rule 110, the 

SCAQMD has prepared a Draft Environmental Assessment (EA) to analyze environmental 

impacts from the project identified above pursuant to its certified regulatory program. The Draft 

EA was released for public review and comment on Thursday, October 16, 2008. The 30-day 

public review and comment period ends at 5 p.m. on Friday, November 14, 2008. Any 

comments received during this period will be responded to and included in the Final EA. The 

environmental analysis in the Draft EA concluded that PR1147 would not generate any 

significant adverse environmental impacts. The EA is available at AQMD Headquarters, by 

calling the AQMD Public Information Center at (909) 396-2039, or by accessing AQMD’s 

CEQA website at: www.aqmd.gov/ceqa.

SOCIOECONOMIC ASSESSMENT 

An analysis of Rule 1147 assessing the socioeconomic impacts was conducted and the 

socioeconomic report was released 30 days prior to the Board hearing. 

DRAFT FINDINGS UNDER CALIFORNIA HEALTH & SAFETY CODE

SECTION 40727

California Health and Safety Code Section 40727 requires that prior to adopting, amending or 

repealing a rule or regulation, the AQMD Governing Board shall make findings of necessity, 

authority, clarity, consistency, non-duplication, and reference based on relevant information 

presented at the public hearing and in the staff report. In order to determine compliance with 

Sections 40727, 40727.2 requires a written analysis comparing the proposed rule with existing 

regulations.

The draft findings are as follows:
PR 1147 Staff Report

 3 - 4 December 2008 

Necessity: A need exists to adopt Rule 1147 to reduce emission limits from combustion 

equipment in order to meet federal and state ambient air quality standards. 

Authority: The AQMD obtains its authority to adopt, amend, or repeal rules and regulations 

from California Health and Safety Code Sections 39002, 40000, 40001, 40440, 40702, 40725 

through 40728, and 41508.

Clarity: PR1147 has been written or displayed so that its meaning can be easily understood by 

the persons affected by the rule.

Consistency: PR1147 is in harmony with, and not in conflict with or contradictory to, existing 

federal or state statutes, court decisions or federal regulations.

Non-Duplication: PR1147 does not impose the same requirement as any existing state or 

federal regulation, and is necessary and proper to execute the powers and duties granted to, and 

imposed upon the AQMD. 

Reference: In amending this rule, the following statues which the AQMD hereby implements, 

interprets or makes specific are referenced: Health and Safety Code sections 39002, 40001, 

40702, 40440(a), and 40725 through 40728.5.

INCREMENTAL COST-EFFECTIVENESS 

Health and Safety Code Section 40920.6 requires an incremental cost-effectiveness analysis for 

Best Available Retrofit Control Technology (BARCT) rules or emission reduction strategies 

when there is more than one control option that would achieve the emission reduction objective 

of the proposed ruleamendments, relative to ozone, CO, SOx, NOx, and their precursors. 

The only option for reducing NOx emission from equipment affected by PR1147 is replacement 

or upgrade of burner systems. Some ovens, furnaces or heated tanks use electricity to heat the 

unit. However, these equipment are either small (oven, furnace or heated tank) and do not 

require a District permit or are unique applications that require electric heat (electric induction 

furnace). Discussions with users and equipment manufacturers indicate that equipment subject 

to PR1147 cannot retrofit to electric heat or require fuel fired burners to produce the heat and 

temperature control required by their processes. Because there is not more than one control 

option that would achieve the emission reduction objective for the combustion equipment 

regulated by PR1147, an incremental cost-effectiveness analysis has not been prepared. 

COMPARATIVE ANALYSIS 

Under Health and Safety Code Section 40727.2, the AQMD is required to perform a comparative 

written analysis when adopting, amending, or repealing a rule or regulation. The comparative 

analysis is relative to existing federal requirements, existing or proposed AQMD rules and air 

pollution control requirements and guidelines that are applicable to industrial, institutional, and 

commercial combustion equipment. 
PR 1147 Staff Report

 3 - 5 December 2008 

The AQMD is not aware of any state or federal requirements regulating air pollution that are 

applicable to in-use PR1147 units. Because there are no state or federal requirements for in-use 

PR1147 units, the proposed rule isamendments are not in conflict with and do not duplicate 

current AQMD, state or federal requirements. 
REFERENCES 
PR 1147 Staff Report

 R - 1 December 2008 

REFERENCES 

ASTEC Incorporated, 2008. http://www.astecinc.com, last accessed October 29, 2008. 

Eclipse, Incorporated, 2008. Burner product information provided by Dennis Downey of Eclipse 

and Allan Roughton of Wirth Gas Equipment, June 20, 2008. 

EPA, 2002. EPA Air Pollution Control Cost Manual, Sixth Edition (EPA-452-02-001), United 

Stated Environmental Protection Agency, January 2002 

Maxon Corporation, 2008. Burner product information provided by Stacy T. Mulrooney of 

Maxon, April 29, 2008. 

North American Manufacturing Company, 2008. http://www.namfg.com, last accessed October 

29, 2008. 

SCAQMD, 2008. Staff Repot: Proposed Rule 1146 - Emissions of Oxides of Nitrogen from 

Industrial, Institutional, and Commercial Boilers, Steam Generators, and Process Heaters. 

South Coast Air Quality Management District, September 2008.

SCAQMD, 2007. Air Quality Management Plan, Final 2007 AQMP Appendix IV-A, District’s 

Stationary and Mobile Source Control Measures, South Coast Air Quality Management District, 

June 2007. 

SCAQMD, 2006. Staff Repot: Proposed Rule 1146.2 - Emissions of Oxides of Nitrogen from 

Large Water Heaters and Small Boilers. South Coast Air Quality Management District, May 

2006. 

SCAQMD, 2005. Staff Report: Proposed Rule 1146.2 - Emissions of Oxides of Nitrogen from 

Large Water Heaters and Small Boilers. South Coast Air Quality Management District, January 

2005. 

SCAQMD, 1999. Staff Report: Proposed Rule 1121 - Control of Nitrogen Oxides From 

Residential Type Natural Gas-Fired Water Heaters. South Coast Air Quality Management 

District, November 1999. 

SCAQMD, 1997. Final Staff Repot for: Proposed Rule 1146.2 - Emissions of Oxides of 

Nitrogen from Large Water Heaters and Small Boilers. South Coast Air Quality Management 

District, December 1997. 

SCAQMD, 1996. 1997 Air Quality Management Plan, Appendix IV-A, Stationary and Mobile 

Source Control Measures, South Coast Air Quality Management District, November 1996. 
APPENDIX A: DRAFT PUBLIC COMMENTS AND RESPONSES 
PR 1147 Staff Report

 A - 1 December 2008 

DRAFT PUBLIC COMMENTS AND RESPONSES 

The following comments include those received at the PR1147 Public Workshop on September 

30, 2008 and sent to AQMD staff by October 24, 2008. Comments from an AQMD Public 

Consultation meeting on October 28 are also included. 

Comment: Which equipment is subject to the rule? Are units rated less than two million Btu 

per hour exempt? 

Response: Any combustion process/equipment with NOx emissions that requires an AQMD 

permit is subject to PR1147. A unit would be subject to the rule if it requires a permit because of 

VOC or particulate emissions and it uses a burner to heat the process. A unit with burners rated 

less than two million Btu per hour that requires a permit for VOC or particulate emissions is 

subject to the rule. 

Comment: What requirements do other air districts have for these types of equipment? 

Response: Other districts (e.g., San Joaquin Valley Unified APCD) have requirements for 

larger heaters, dryers, ovens, etc. that are similar to the limits in PR1147. 

Comment: Do owners have the choice of the ppm or pound per million Btu emission limits? 

Response: Yes, equipment owners and operators will have a choice of emission limits with the 

exception of units that heat air with exhaust oxygen concentrations near ambient levels (greater 

than 18% oxygen) which will have to comply with the pound per million Btu limit. This would 

require measurement of fuel use and exhaust flow rate while testing for NOx concentration in the 

exhaust. Staff will also review and consider alternative protocols submitted to the District at 

least 90 days in advance of the test date. 

Comment: How will the proposed certification program for burners and equipment work? 

Response: While details of the certification program will be developed after rule adoption, Staff 

envisions that certification will be similar to other AQMD certification programs such as the one 

for Rule 1146.2, which addresses small boilers and large water heaters rated less than two 

million Btu per hour. 

Comment: Do we need to apply for a permit when modifying equipment? 

Response: A permit modification may be required. Staff is evaluating options for streamlining 

the process and reducing cost where possible. 

Comment: The AQMD should consider a low fuel usage exemption. Replacement of a small 

burner of the size 150,000 Btu/hour will have higher cost effectiveness (e.g., $13,000 per ton) 

and emission reductions could be as low as 21 pounds per year. This reduction is not significant. 

Response: The rule provides a later compliance date for equipment with lower emissions (2015 

or later). However, NOx emission reductions are needed from this equipment group in order to 
PR 1147 Staff Report

 A - 2 December 2008 

meet emission reduction commitments in the 2007 Air Quality Management Plan and comply 

with ambient air quality standards. While some individual pieces of equipment have small 

emissions, the cumulative emissions from these small units are significant. Our region needs 

NOx emissions in the District to be reduced significantly in order to meet the federal PM2.5 

ambient standard by 2014 and make significant progress toward meeting the 8-hour federal 

ozone standard. 

Please note that there are many other combustion equipment categories covered by other recent 

AQMD rule amendments with emission limits comparable to those from equipment subject to 

PR1147. For instance, the emission reductions from small units affected by this proposed rule 

are comparable to the reductions from small boilers from the last amendment of AQMD Rule 

1146.2. Rule 1146.2 does not have a low use or low Btu exemption. Under Rule 1146.2 boilers 

and water heaters less than 400,000 Btu/hour will be required by 2012 to reduce emissions from 

55 ppm to 20 ppm. Emissions for small burners subject to PR1147 can vary from 80 ppm to 170 

ppm or more. Current residential tank type water heaters less than 75,000 Btu/hour that are sold 

in the District meet an even lower emission limit of 15 ppm (10 nanograms/Joule) with 

emissions of about one pound per year. A new car has annual NOx emissions similar to a 

residential water heater. The equipment affected by PR1147 is the last category of permitted inuse combustion sources that is not currently regulated by the AQMD. 

The cost effectiveness provided in the staff report is an average across the range of equipment. 

The cost effectiveness calculated by the commenter is in the same range as estimated by AQMD 

staff. 

Comment: Specify that solid fuel-fired equipment is exempt. 

Response: Solid fuel-fired equipment is excluded by the applicability section of the proposed 

rule. However, to clarify this issue, staff has added a specific exemption for municipal solid 

waste incinerators. 

Comment: Are flares at RECLAIM facilities exempt? 

Response: Yes. In addition, the proposed rule has been revised in the applicability, definitions 

and exemption sections to clarify that this equipment is exempt. 

Comment: Most use of propane and LPG is for remediation units in remote locations. Most 

burners have higher NOx emissions when burning these fuels. This equipment should be 

exempt. 

Response: The proposed rule has been revised to state that remediation units fueled with 

propane, butane or LPG are exempt from the emission limit. However, these units must be 

tested or certified to meet the applicable emission limit while fueled with natural gas and must 

meet the limit when natural gas is available. 

Comment: The AQMD should have emission limits on a pound per hour basis. 
PR 1147 Staff Report

 A - 3 December 2008 

Response: Pound per hour or pound per day permit emissions limits are determined for units 

after applying for a permit. The permit processing engineer determines the allowable emissions 

in pounds per hour or pounds per day based on the pounds per mmBtu allowed by a rule 

emission limit. 

NOx emission limits in new AQMD source specific rules are expressed in parts per million 

referenced to a specific oxygen concentration and an equivalent pounds per million Btu of heat 

input. The pounds per million Btu of heat input option allows more efficient equipment to emit 

at a higher concentration (ppm) but still produce the same or less mass emissions (pounds per 

hour) as a unit complying with the parts per million limit. The pounds per million Btu limit is 

also used by permit processing engineers to derive permit limits in pounds per hour, pounds per 

day or pounds per million cubic feet of natural gas. 

A pound per hour limit would not be equitable. A unit with a burner operating at a lower heat 

output could emit more pounds per million Btu at a much higher concentration (ppm) than a unit 

with a larger burner firing at a higher rate. In order to achieve equivalent NOx reductions to 

those from the emission limits in PR1147 and AQMP Control Measure CMB-01, a pound per 

hour limit would have to be more stringent than current BACT and would be unfair to owners of 

both large and small units. 

Comment: Now is not a good time for the AQMD to pass new rules, add to the cost of new 

equipment, and add the expense of modifying existing equipment. The AQMD should postpone 

this rule. 

Response: AQMD staff recognizes that there is currently a slowdown in the economy. 

However, emission reductions from the equipment regulated by this rule will be required in 

order to meet ambient air quality standards. The proposed rule has been revised to provide 

additional time for new projects and for specific categories of equipment to meet the proposed 

emission limits. In addition, the rule has been designed to delay compliance for most equipment 

by several years, and provides additional time for units with new burners or lower emissions. 

The proposed rule will phase-in compliance for smaller and lower emitting equipment starting 

2015. Compliance for equipment with higher emissions is phased-in, based on equipment age, 

starting January 1, 2010, and continuing until 2014. In 2010, equipment at least 25 years old and 

a NOx permit limit greater than one pound/day NOx emissions will be required to meet the 

proposed emission limits, followed by equipment 20 years old and then 15 years old. 

Approximately half of the equipment has emissions less than or equal to one pound per day and 

must meet limits starting in 2015. 

Comment: The cost can be significant for smaller businesses to upgrade their equipment. It 

will cost $10,000 to $16,000 to change burners in a typical oven of the size used to cure 

coatings. The rule will also increase cost for new equipment for equipment manufacturers and 

users. This is too expensive for smaller businesses and will cause businesses to leave the 

District. In addition, the AQMD should provide additional time before new projects must 

comply with the rule. Installers will now have to change their bids for new projects proposed for 

next year. 
PR 1147 Staff Report

 A - 4 December 2008 

Response: The cost estimate of $10,000 to $16,000 provided by the commenter is consistent 

with costs estimated by AQMD staff from information provided by equipment vendors. The cost 

for large metal melting or heat treating furnaces will be much higher because multiple burners 

with higher heat output must be replaced. However, the cost to comply for most existing smaller 

or lower emitting equipment is delayed until 2015 or later. Staff has also revised the proposed 

rule to delay the compliance date for new equipment until 2010. The cost effectiveness for this 

rule is $5,000 to $7,000 per ton of NOx reduced and is much lower than for other AQMD NOx 

rules and AQMD BACT guidelines. 

Comment: Burner manufacturers and vendors will not guarantee the emission limits proposed 

for ovens and other equipment. Some burners cannot meet the emission limits at low fire. The 

available burners will not work in all applications. 

Response: Staff has evaluated current burner technology and discussed the achievable emission 

limits with manufacturers. Several vendors have products that can achieve the proposed 

emission limits. Staff has changed the proposed rule limit for ovens, dryers, heaters, furnaces 

and other equipment with process temperatures less than 800 °F from 20 ppm to the current 

BACT limit of 30 ppm. The proposed rule also provides a much later compliance date for 

equipment for which manufacturers have only a limited number of models or sizes of burners 

that meet the proposed emission limit. AQMD staff’s experience suggests that manufactures 

will not guarantee burners to a lower limit than is required by BACT or rule. 

Each burner manufacturer has a different focus and its products have advantages over others in 

certain applications. However, each manufacturer has competing products that meet the 

emission limits proposed in the rule. 

Comment: The rule should specify exactly which types of equipment are subject to the rule. 

The emission limit table in the rule is confusing. 

Response: The rule and emission limit table has been revised to provide additional specificity 

regarding emission limits for equipment, and the rules list of common equipment names has been 

expanded. However, since the purpose of the rule is to reduce emissions from equipment for 

which there are no current NOx limits in AQMD Regulation XI, and each piece of equipment 

can be assigned many different names by manufacturers, vendors and operators, it is not possible 

to identify every conceivable name that could be used for any specific unit. The proposed rule 

clearly states the most common names used by equipment subject to the rule, and that the list of 

names is not exclusive. The rule also clearly states that the rule regulates equipment that is not 

subject to NOx emission limits in other AQMD Regulation XI rules, and identifies those rules. 

Comment: Do BACT limits supersede the proposed rule limits? 

Response: If BACT for new, relocated or modified equipment is more stringent than the rule 

NOx limit, then BACT would be required by the permit for the new, relocated or modified 

equipment. If the BACT limit for the equipment at the time the equipment was installed or last 

modified is less stringent than the rule NOx limit, than the equipment must comply with the new 

rule limit. 
PR 1147 Staff Report

 A - 5 December 2008 

Comment: Explain how afterburners, vapor incinerators, oxidizers, degassing units and 

remediation units (soil and water treatment units) must meet the proposed emission limit. Is this 

equipment subject to the rule? 

Response: Yes, afterburners, vapor incinerators, oxidizers, degassing units and remediation 

units are subject to the rule. The purpose of the rule is to require new and existing equipment to 

switch to newer technology burners with lower emissions. Burners that only use 100% natural 

gas, LPG, propane or butane in the burner and that incinerate air toxics, VOCs, or vapors by 

moving the gaseous stream to be treated past the burner are subject to the rule limits. Burners 

used to heat thermal or catalytic units are also subject to the emission limits. 

However, the proposed rule requires that burners used by afterburners, vapor incinerators, 

degassing units, oxidizers and remediation equipment for incineration of air toxics, VOCs and 

other vapors meet NOx emission limits while burning 100% natural gas or other fuel and a 

gaseous waste stream is not being incinerated by the burner itself. 

Flare based systems that mix fuel and digestor gas, landfill gas, VOCs or vapors prior to 

combustion in the burner are proposed to be exempt (see following comment and response). 

Burners used to heat thermal or catalytic units must comply with the emission limits at all times. 

Existing remediation units will be subject to the rule limits when they are moved or require a 

burner replacement on or after January 1, 2011. 

Comment: Specific types of equipment (called by a variety of names including afterburners, 

vapor incinerators, and oxidizers) are based on flare technology and do not use 100% natural 

gas, propane, or LPG except for pilots or to start up the flare. Fuel is mixed with the vapors that 

are to be incinerated prior to the burner in the flare. The fuel is used to maintain the BTU going 

to the burner. Tuning this type of equipment for lower NOx emissions on natural gas could 

result in higher NOx emissions when incinerating VOCs or vapors. This type of equipment 

should be exempt from the rule. 

Response: AQMD staff has modified the proposed rule to provide an exemption for flare 

technologies and other processes where fuel and digestor gas, landfill gas, vapors, VOCs or air 

toxics are mixed prior to the combustion zone and/or only use fuel for a pilot. Other processes 

that mix fuel and air toxics, VOCs or vapors prior to combustion include thermal and catalytic 

oxidizers. However, thermal and catalytic oxidizers also include a burner that uses 100% natural 

gas, LPG or propane to heat the thermal or catalytic component. The burners used by oxidizers 

to heat thermal or catalytic elements will not be exempt. Staff recognizes that each specific type 

of burner has a range of NOx emissions. The goal of this rule is facility modernization by 

replacement of older style burners with newer technology that has lower emissions of NOx and 

other pollutants. However, staff feels that the best way to address NOx emissions from flare 

based systems is through a BACT analysis and has modified the proposed rule to provide an 

exemption at this time. 

Comment: How does this rule impact carbon dioxide emission reductions programs developed 

by the state of California? Some burners increase the amount of excess air going through the 

burner to reduce NOx and this could decrease efficiency. 
PR 1147 Staff Report

 A - 6 December 2008 

Response: The emission limits proposed in the rule would not increase emissions of carbon 

dioxide. Staff expects that owners of equipment will often see lower fuel use and hence gains in 

efficiency when replacing their old burners with newer ones. Burner manufacturers have 

indicated to staff at PR1147 Task Force meetings that most applications should see a small 

increase or no change in efficiency (a decrease or no change in fuel consumption). However, 

staff has not quantified the benefits of improved efficiency. 

Most of the equipment subject to PR1147 heats air. In many applications, the effect of an 

increase in the amount of air going through the burner can be offset by reducing in the amount of 

other air pulled into the system by a blower or exhaust fan. The same amount of air, regardless 

of the source, at the same temperature would result in the same fuel use and efficiency. 

Increased excess air will also help distribute heat in an oven or furnace and prevent stratification. 

More even heating in a unit can reduce fuel use. 

Comment: How will the rule be enforced? 

Response: Inspectors will check equipment age using ratings plates, records and other 

information and notify companies if their equipment is not in compliance. AQMD staff or 

contractors will also test equipment emissions on a random basis. Owners and operators of the 

equipment will be responsible for updating equipment before the compliance date, testing the 

equipment and maintaining records on-site. 

Comment: Staff held the Public Workshop on a religious holiday and some individuals were 

unable to attend. 

Response: Staff regrets the oversight in scheduling the Public Workshop on a religious holiday. 

However, staff held an additional public consultation meeting on October 28, 2008. In addition, 

staff has held separate meetings or teleconferences with individuals who requested meetings. 

Staff also extended the submittal date for written comments on the preliminary draft rule. 

Comment: Name the manufacturers with burners that produce burners meeting the emission 

limits in the proposed rule and products that meet the emission limits. 

Response: The two manufacturers that provide the majority of burners for equipment subject to 

PR1147 are Maxon and Eclipse. However, other companies also provide burners, but for a 

narrow range of applications (e.g., ASTEC and North American). Each manufacturer has a 

different focus and has advantages over the others in certain applications. However, they have 

competing products that meet the emission limits proposed in the rule. 

Comment: The categories of equipment in the rule are two general. The emission limit table is 

a one size fits all approach. Individual processes are two variable and some may not be able to 

meet these emission limits. In particular, heat treating and forging furnaces are often unique 

designs and some furnaces may not be able to achieve the proposed emission limit for 

metallurgical processes. The most important issue for heat treating and forging is maintaining 

temperature uniformity throughout the furnace in order to meet customer specifications. New 

burners may not be able to maintain uniformity and meet the proposed emission limit.
PR 1147 Staff Report

 A - 7 December 2008 

Response: Staff has proposed the emission limits based on AQMD and other air district’s 

BACT determinations, recent permit limits for equipment in the AQMD, burner manufacturer 

information, and emission levels achieved by burners in equipment subject to PR1147 and other 

AQMD rules. The emission limit table in the rule groups equipment with similar emission limits 

for the convenience of permit applicants. 

For equipment categories for which there are a limited number of burners meeting the proposed 

limits, PR1147 provides additional time for new and existing in-use equipment to meet the 

proposed rule limit. Such categories include food ovens, immersion tube heating (e.g., fryers, 

heated process tanks and parts washers), tar pots and remediation units. Note that one half of the 

units will not be subject to the emission limits until 2015. In addition, PR1147 allows facilities 

with 5 or more units additional time for all units to comply with emission limits.

Staff recognizes that heating and forging furnaces are often unique designs and that operators of 

furnaces must meet detailed specifications regarding temperature control in order to meet 

customer requirements. Staff will monitor implementation of PR1147 and report back to the 

Stationary Source Committee of the AQMD Governing Board regarding this and other 

implementation issues and proposes future rule adjustments if necessary.

Comment: The District should provide owners and operators of equipment with guidance 

documents and forms to assist them in complying with the source testing component of the 

proposed rule.

Response: Staff will develop guidance documents specific to PR 1147 to assist owners and 

operators in complying with testing requirements.
PR 1147 Staff Report

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