MEMORANDUM 

TO: Docket ID No. EPA-HQ-OAR-2002-0058 

FROM: Jim Eddinger, U.S. Environmental Protection Agency, OAQPS 

DATE: November 2011 

SUBJECT: Revision of Alternate Equivalent Output-Based Emission Limits for Boilers and 

Process Heaters located at Major Source Facilities 

The purpose of this memorandum is to present the revised methodology used during 

reconsideration of the Boiler MACT (40 CFR subpart DDDDDD) and the revised results for the 

proposed alternate output-based emission limits that are equivalent to the maximum achievable 

control technology (MACT) floor determinations for boilers and process heaters at major sources 

of hazardous air pollutants (HAP) reported in the memorandum “Revised MACT Floor Analysis 

(November 2011) for the Industrial, Commercial, and Institutional Boilers and Process Heaters 

National Emission Standards for Hazardous Air Pollutants – Major Source.” 

The methodology was modified based on the petition for reconsideration submitted by 

the Alliance for Industrial Efficiency and US Clean Heat Power Association. The petitioner 

found that EPA’s calculations often resulted in efficiencies that were unrealistically high, often 

above 100%, which is a physical impossibility. The petitioners attributed this to the fact that 

EPA had disregarded feedwater temperature (industry average being 280 degrees F) and if 

included would cause the average efficiency calculation to drop to more realistic levels. 

In addition, Wisconsin Electric Power commented that the output based standards, in 

units of pounds per million Btu steam (lb/MMBtu steam), punish electric generating units (those 

not covered by the utility MACT), by not taking into account turbine efficiencies. 
Thus, the alternate equivalent output-based emission limits in the final rule were revised 

based on recalculated boiler efficiencies that included the heat (energy) associated with the 

feedwater. Also, as described later in this memorandum, equivalent output-based emission 

limits in units of pounds per megawatt-hour (lb/Mwh) were determined for units generating 

electricity only. 

Revision of Output-Based Emission Limits in Units of lb/MMBtu steam

 In the January 2011 memorandum, the conversion from the final MACT limits, in pound 

per million Btu heat input (lb/MMBtu), to an equivalent output basis, lb/MMBtu steam, was 

based on the calculated average boiler efficiency of the best performing units. Boiler efficiency, 

in that earlier memorandum, was defined as steam (Btu output) divided by the heat or fuel (Btu 

input). As the petitioners point out this is not the appropriate approach to calculating boiler 

efficiencies because it does not account for the energy to heat the feedwater. 

The boiler efficiencies of the best performing units for each subcategory were revised 

using Equation 1: 

Equation 1

The feedwater Btu in was calculated assuming the industry average temperature of 280o

F, 

resulting in a heat content value of 249.3 Btu/lb feedwater. The steam energy output and the 

heat (fuel) input for each best performing unit were the same as previously determined. Even 

with this new approach to include the feedwater heat, the calculated boiler efficiency for some 

best performing units were unrealistically high, as high as 110 percent. This, we assumed, was 
due to one of the reported values being inaccurately reported. Thus, we made the assumption 

that a calculated boiler efficiency of greater than 85 percent was an outlier. We then, for each 

subcategory, determined the subcategory-specific average boiler efficiency using all the best 

performing units within that particular subcategory having appropriate boiler efficiencies. 

Average boiler efficiencies are specific to a certain subcategory. Sixteen different subcategories 

of existing units were targeted in this analysis, all of which are listed in Table 1. The average 

boiler efficiencies in Table 1 were developed based only on those units that were also identified 

as best performing units for the reconsideration proposal. 

However, the revised average boiler efficiencies in Table 1 are not the appropriate 

conversion factors to convert from fuel (MMBtu/h) in to steam (MMBtu/h) generated. They are 

the more appropriate average boiler efficiencies, but as defined, they are not the appropriate 

conversion factors to go from heat (fuel) input to total steam generated. The boiler efficiencies 

are total steam generated minus steam used for heating the feedwater divided by the heat (fuel) 

input. So, the output-based limits (lb/MMBtu steam) in the proposed rule were developed by 

applying the average conversion factor (steam Btu out/fuel Btu in) to the proposed MACT limits 

to develop the revised alternate output-based limits in lb/MMBtu steam. The conversion factor 

for each subcategory was calculated by averaging the conversion factor for each best performing 

unit having an appropriate boiler efficiency. 

 
Table 1 – Conversion Factors for Existing Sources 

Subcategory 

Boiler Efficiency (%) Conversion 

Factor 

(Steam Btu Out/ 

Fuel Btu In) 

Comment 

Range Average 

Solid 45.5 – 84.9 72.3 0.89 

Biomass – Dutch 

Oven (DO) 53.4 – 60.5 58.2 0.72 

Biomass – Fluidized 

Bed (FB) 62.9 – 67.0 65.0 0.81 

Biomass – Fuel Cell 

(FC) 45.5 – 67.2 56.4 0.37 

Biomass – 

Suspension Burner 

(Susp.B) 

78.4 – 78.4 78.4 0.99 Based on design 

steam values 

Biomass – 

Suspension Grate 

(Susp.G) 

53.6 – 64.9 57.8 0.80 

Biomass – 

Wet/stoker 60.0 – 81.2 69.5 0.87 

Biomass – 

Dry/stoker 

No output 

data on 

dry/stoker 

69.5 0.87 Same as 

Wet/stoker 

Coal - FB 68.1 – 83.6 78.6 0.96 

Coal – Pulverized 

Coal (PC) 60.9 – 84.7 77.9 0.99 

Coal - Stoker 58.7 – 84.9 75.9 0.95 

Liquid 60.9 – 73.3 67.1 0.80 

Liquid - Heavy 73.3 73.3 0.83 

Liquid - Light 60.9 60.9 0.77 Based on 1 unit 

Non-Continental 

Liquid 

No output 

data on NonContinental 73.3 0.83 Assumed same as 

heavy liquid 

Process Gas 50.4 50.4 0.60 Based on 1 unit 

Assumption – any unit with a boiler efficiency of greater than 85% was an outlier. 

 

For each new subcategory, Table 2 lists the boiler efficiency of the best performing unit 

used as the basis of the new source MACT floor calculations, having an appropriate boiler 

efficiency, for each particular HAP/subcategory. If the best performing unit did not have data 

available, data from the next lowest emitting unit in the subcategory were used to fill data gaps. 

The conversion factor listed in Table 2 is the unit’s corresponding conversion factor. 
Table 2 – Conversion Factors for New Sources 

Subcategory 

Best Performing Unit 

Comment Facility ID Unit ID 

Boiler 

Efficiency 

(%) 

Conversion 

Factor 

(Steam Btu 

Out/Fuel 

Btu In) 

Hg Solid INPurdueUniverisity Boiler 5 76.0 0.92

HCl Solid ARPotlatchForestWa

rren 

Wellons 

Boiler 60.5 0.74

Hg Liquid MNGPDuluth EU33 Boiler 

#3 73.3 0.92

HCl Liquid MNGPDuluth EU33 Boiler 

#3 73.3 0.92

PM Biomass - 

DO

ARPotlatchForestWa

rren 

Wellons 

Boiler 56.1 0.66

PM Biomass - 

FB

ORGeorgiaPacificW

aunaMill EU35 67.0 0.82

PM Biomass - 

FC IDPotlatch PE-1 CE 56.4 0.37

PM Biomass – 

Susp.B

MNAndersonCorpBa

yport 

Boiler 11 

EU620 78.4 0.99

PM Biomass – 

Susp.G FLUSSugarCorp Boiler No.8 57.8 0.80

PM Biomass – 

Wet/stoker MSGPNewAugusta AA-015 PB 70.3 0.87

PM Biomass – 

Dry/stoker

No output data on PM Biomass – 

Dry/stoker 70.3 0.87

Same as PM 

Biomass – 

Wet/stoker 

PM Coal - FB IAArchersDanielsMi

dlandDesMoines 

Asea Boiler 

#1 80.2 0.98

PM Coal - PC IAUofNorthernIowa Boiler #3 81.0 1.01

PM Coal - 

Stoker TNCargillMemphis Stoker 

Boiler 8001 80.9 1.00

PM Liquid 

Heavy MNGPDuluth EU33 Boiler 

#3 73.3 0.92

PM Liquid 

Light

SCGPChemRussellvi

lle FO Boiler 60.9 0.77

CO Biomass - 

DO

ARWeyerhaeuserDie

rksMill SN-45 53.4 0.67

CO Biomass - 

FB No output data on CO Biomass - FB 67.0 0.82 Same as PM 

Biomass - FB

CO Biomass - 

FC IDPotlatch PB-1 CE 45.5 0.57
CO Biomass – 

Susp.B

No output data on CO Biomass – 

Susp.B 78.4 0.99

Same as PM 

Biomass – 

Susp.B 

CO Biomass – 

Susp.G FLUSSugarCorp Boiler No.7 53.6 0.66

CO Biomass – 

Wet/stoker

INConsolidatedGrain

andBarge P17B 66.1 0.84

CO Biomass – 

Dry/stoker

No output data on CO Biomass – 

Dry/stoker 66.1 0.84

Same as CO 

Biomass – 

Wet/stoker 

CO Coal - FB No output data on CO Coal - FB 80.2 0.98 Same as PM 

Coal - FB 

CO Coal - PC AZCatalystPaperSno

wflake PB #2 84.2 1.02

CO Coal - 

Stoker

WVDuPontWashingt

onWorks P05 76.2 0.96

CO Liquid 

Heavy

ORGeorgiaPacificW

aunaMill EU33 0.73

No boiler 

efficiency 

available for 

this unit 

CO Liquid 

Light

SCGPChemRussellvi

lle FO Boiler 60.9 0.77

TSM Biomass 

- DO

WAWeyerhaeuser 

Raymond 

Hog Fuel 

Boiler EU1 59.9 0.75

TSM Biomass 

- FB NDCargillWestFargo FW Boiler 

(EU43) 62.9 0.79

TSM Biomass 

- FC IDPotlatch PB-1 CE 45.5 0.57

TSM Biomass 

– Susp.B

TXDibollTempleInland PB-44 78.4 0.99

TSM Biomass 

– Susp.G

No output data on TSM Biomass – 

Susp.G 57.8 0.80

Same as PM 

Biomass – 

Susp.G 

TSM Biomass 

– Wet/stoker MSGPNewAugusta 

AA-015 

Power 

Boiler 

80.2 0.97

TSM Biomass 

– Dry/stoker

No output data on TSM Biomass – 

Dry/stoker 80.2 0.97

Same as 

TSM 

Biomass – 

Wet/stoker 

TSM Coal - FB ILPolyOne B1 68.1 0.86

TSM Coal - PC IDTASCONampa 

Babcock 

and Wilcox 

(B&W) #1 

79.6 1.00

TSM Coal - 

Stoker

VAUniversityofVirgi

nia 7103-1-01R 58.7 0.74
Assumption – any unit with a boiler efficiency of greater than 85% was an outlier. 

Conversion factor for Non-continental is the same as for Liquid – Heavy 

Conversion factor for process gas same as for existing units 

We determined the alternate output-based emission limits (lb/MMBtu steam) for each 

MACT emission limit by applying the conversion factor for the subcategory to the values 

reported in the MACT Floor Memo using Equation 2:

Equation 2 

For CO, the input-based emission limits are in units of parts per million at three percent 

oxygen (ppm @ 3% O2). These emission limits were first converted to lb/MMBtu before 

calculating an output-based emission limit. Equation 3 was used to convert ppm @ 3% into units 

of lb/MMBtu:

Equation 3

The following Fd factors were selected from EPA Method 19 for the various fuel types: 

 For coal, 9780 dscf/MMBtu (from “Bituminous Coal” in Method 19) 

 For biomass, 9240 dscf/MMBtu (from “Wood” in Method 19) 

 For all liquids, 9190 dscf/MMBtu (from “Oil” in Method 19) 

 For process gas, 8760 dscf/MMBtu (from “Natural Gas” in Method 19) 

Finally, if the calculated output-based limit for new sources was less-stringent than the 

calculated output-based limit for existing sources for the same subcategory, the existing source 

limit was used as the new source limit. This is identical to the methods used to establish inputbased limits for new sources, as described in the memorandum, “Revised MACT Floor Analysis 
(November 2011) for the Industrial, Commercial, and Institutional Boilers and Process Heaters 

National Emission Standards for Hazardous Air Pollutants – Major Source” in the docket. 

The alternate output-based emission limits (lb/MMBtu steam) are summarized for each 

subcategory in Appendix A (existing sources) and Appendix B (new sources). Appendix C 

presents the list of the best performing units for each of the five HAP categories. Appendix D 

presents the boiler efficiency (with feedwater) and conversion factor for each of the best 

performing units for which we obtained steam output information. 

Calculation of Output-Based Emission Limits in Units of lb/Mwh

 In response to the comment raised that the output emission limit format of lb/MMBtu 

steam is not appropriate for electric generating boilers that are subject to the Boiler MACT, 

output-based emission limits in the format of lb/Mwh were also developed that are equivalent to 

the MACT floor determinations for boilers and process heaters at major sources of HAP reported 

in the memorandum “Revised MACT Floor Analysis (November 2011) for the Industrial, 

Commercial, and Institutional Boilers and Process Heaters National Emission Standards for 

Hazardous Air Pollutants – Major Source.” 

The best performing units that are electric generating only were identified by ICF 

International. Appendix C contains a column at the end that identifies the unit as CHP, Power 

Only, or Possibly Thermal Only. ICF also filled in heat rate info for most of the power only 

boilers using information from the Department of Energy, Energy Information Administration 

(EIA) Form 923 or eGRID 2010. Table 3 presents the best performing units that are electric 

generating only and for which we were able to obtain their heat rate. 
Table 3 – Heat Rates for Power-Only Best Performing Units 

Facility ID Combustor ID Fuel 

Category 

Heat Rate 

(Btu/kWh) Source 

CACovantaDelano Unit 1 Biomass 13,696 EIA Form 923 

MEBoralexStratton Boiler #1 Biomass 12,262 EIA Form 923 

MIGenessePowerStation Boiler 01 Biomass 15,808 EIA Form 923 

NJVinelandMuniElectricHowardDown Unit 9 Oil 15,322 eGRID 2010 

NYBlackRiverGen E00001 Coal 14,148 EIA Form 923 

NYBlackRiverGen E00002 Coal 13,934 EIA Form 923 

NYBlackRiverGen E00003 Coal 13,726 EIA Form 923 

MICityofEscanaba EUBOILER#1 Coal 12,957 eGRID 2010 

MIConsumerEnergyCo EUKEWANEEBOILER Oil 13,332 EIA Form 923 

MIConsumerEnergyCo EUAUXBLR12 Oil 13,332 EIA Form 923 

NCEPCORRoxboro 1-A Coal 10,246 EIA Form 923 

NCEPCORRoxboro 1-B Coal 10,246 EIA Form 923 

NCEPCORRoxboro 1-C Coal 10,246 EIA Form 923 

NYConEd59thStStationN

ewYork Boiler 118 Oil 13,154 EIA Form 923 

 

The average heat rate for the various fuel types were: 

 For coal, 12,215 Btu/kWh (or 12.2 MMBtu/Mwh), based on 7 units, 

 For biomass, 13,922 Btu/kWh (or 13.9 MMBtu/Mwh), based on 3 units, 

 For oil, 13,785 Btu/kWh (or 13.8 MMBtu/Mwh), based on 4 units, and 

 For solid fuel (coal + biomass), 12,727 Btu/kWh (or 12.7 MMBtu/Mwh), based on 10 

units. 

None of the best performing units that are gas-fired were identified as power only. 

Therefore, for gas-fired units, we used a heat rate of 10,399 Btu/kWh (or 10.4 MMBtu/Mwh) 

which is reported as the average heat rate of gas-fired steam turbine units for 2009.1

We determined the alternate output-based emission limits (lb/Mwh) to each MACT 

emission limit by applying the average heat rate (MMBtu/Mwh) for each fuel subcategory to the 

values reported in the MACT Floor Memo using Equation 4: 

Equation 4 

 

1 Source: U.S. Energy Information Administration, Form EIA‐860, “Annual Electric Generator Report.”
If the calculated output-based limit for new sources was less-stringent than the calculated 

output-based limit for existing sources for the same subcategory, the existing source limit was 

used as the new source limit. This is identical to the methods used to establish input-based limits 

for new sources, as described in the memorandum, “Revised MACT Floor Analysis (November 

2011) for the Industrial, Commercial, and Institutional Boilers and Process Heaters National 

Emission Standards for Hazardous Air Pollutants – Major Source” in the docket. The alternate 

output-based emission limits (lb/Mwh) are summarized for each subcategory in Appendix A 

(existing sources) and Appendix B (new sources). 
Appendix A 

Output-Based Emission Limits for Existing Boilers and Process Heaters 
Summary of Calculated Output-Based (MACT Floor) Emission Limits for Existing Boilers 

and Process Heaters at Major Sources (Units with heat input capacity of 10 million Btu per 

hour or greater) 

Subcategory Pollutant 

MACT (heat inputbased) proposed 

emission limits 

Outputbased 

emission 

limits 

(lb per 

MMBtu of 

steam 

output)

Outputbased 

emission 

limits 

(lb per 

Mwh)

1. Solid fuel HCl 0.022 lb per MMBtu of 

heat input. 

0.025 0.28 

 Mercury 3.1E-06 lb per MMBtu 

of heat input. 

3.5E-06 4.0E-05 

2. Pulverized coal boilers CO 41 ppm corrected to 3 

percent oxygen, 3-run 

average. 

0.035 0.42 

 PM (or 

TSM) 

0.044 lb per MMBtu of 

heat input; or (5.9E-05 

lb per MMBtu of heat 

input). 

0.045 or 

(6.0E-05) 

0.54 or 

(7.3E-04) 

3. Stokers designed to 

burn coal/solid fossil fuel 

 CO 220 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average 

0.20 2.3 

 PM (or 

TSM) 

0.028 lb per MMBtu of 

heat input; or (8.3E-05 

lb per MMBtu of heat 

input). 

0.030 or 

(8.8E-05) 

0.35 or 

(0.0011) 

4. Fluidized bed units 

designed to burn coal/ 

solid fossil fuel 

 CO 56 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.049 0.57 

 PM (or 

TSM) 

0.088 lb per MMBtu of 

heat input; or (1.7E-05 

lb per MMBtu of heat 

input). 

0.092 or 

(1.8E-05) 

1.1 or (2.1E04) 

5. Stokers/sloped 

grate/others designed to 

burn wet biomass fuel 

 CO 790 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.72 8.7 
Subcategory Pollutant 

MACT (heat inputbased) proposed 

emission limits 

Outputbased 

emission 

limits 

(lb per 

MMBtu of 

steam 

output)

Outputbased 

emission 

limits 

(lb per 

Mwh)

 PM (or 

TSM) 

0.029 lb per MMBtu of 

heat input; or (5.7E-05 

lb per MMBtu of heat 

input). 

0.034 or 

(6.6E-05) 

0.41 or 

(8.0E-04) 

6. Stokers/sloped 

grate/others designed to 

burn kiln-dried biomass 

fuel 

CO 250 ppm by volume on a 

dry basis corrected to 3 

percent oxygen. 

0.23 2.8 

 PM (or 

TSM) 

0.32 lb per MMBtu of 

heat input; or (4.0E-03 

lb per MMBtu of heat 

input). 

0.37; or 

(0.0046) 

4.5 or 

(0.056) 

7. Fluidized bed units 

designed to burn 

biomass/bio-based solid 

 CO 370 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.36 4.1 

 PM (or 

TSM) 

0.11 lb per MMBtu of 

heat input; or (0.0012 lb 

per MMBtu of heat 

input). 

0.14 or 

(0.0015) 

1.6 or 

(0.017) 

8. Suspension burners 

designed to burn 

biomass/bio-based solid 

CO 58 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.046 0.64 

 PM (or 

TSM) 

0.051 lb per MMBtu of 

heat input; or (0.0011 lb 

per MMBtu of heat 

input). 

0.052; or 

(0.0012) 

0.71 or 

(0.016) 

9. Dutch Ovens/Pile 

burners designed to burn 

biomass/bio-based solid 

CO 810 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.89 8.9 

 PM (or 

TSM) 

0.036 lb per MMBtu of 

heat input; or (2.4E-04 

lb per MMBtu of heat 

input). 

0.050 or 

(3.4E-04) 

0.51 or 

(0.0034) 
Subcategory Pollutant 

MACT (heat inputbased) proposed 

emission limits 

Outputbased 

emission 

limits 

(lb per 

MMBtu of 

steam 

output)

Outputbased 

emission 

limits 

(lb per 

Mwh)

10. Fuel cell units 

designed to burn biomass/ 

bio-based solid 

CO 1,500 ppm by volume 

on a dry basis corrected 

to 3 percent oxygen. 

3.2 17 

 PM (or 

TSM) 

0.033 lb per MMBtu of 

heat input; or (4.9E-05 

lb per MMBtu of heat 

input). 

0.090; or 

(1.4E-04) 

0.46 or 

(6.9E-04) 

11. Hybrid suspension 

grate units designed to 

burn biomass/ bio-based 

solid 

CO 3,900 ppm by volume 

on a dry basis corrected 

to 3 percent oxygen, 3-

run average. 

3.9 43 

 PM (or 

TSM) 

0.44 lb per MMBtu of 

heat input; or (4.9E-04 

lb per MMBtu of heat 

input). 

0.55; or 

(6.2E-04) 

6.2 or 

(0.0069) 

12. Units designed to burn 

liquid fuel 

HCl 0.0012 lb per MMBtu of 

heat input. 

0.0015 0.017 

 Mercury 2.6E-05 lb per MMBtu 

of heat input. 

3.3E-05 3.6E-04 

13. Units designed to burn 

heavy liquid fuel 

CO 10 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.0091 0.11 

 PM 0.062 lb per MMBtu of 

heat input. 

0.075 0.86 

14. Units designed to burn 

light liquid fuel 

CO 7 ppm by volume on a 

dry basis corrected to 3 

percent oxygen. 

0.0071 0.076 

 PM 0.0034 lb per MMBtu of 

heat input. 

0.0045 0.047 

15. Units designed to burn 

liquid fuel located in noncontinental States and 

territories 

CO 18 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average based on stack 

test. 

0.017 0.20 

 PM 0.0080 lb per MMBtu of 

heat input. 

0.0097 0.11 
Subcategory Pollutant 

MACT (heat inputbased) proposed 

emission limits 

Outputbased 

emission 

limits 

(lb per 

MMBtu of 

steam 

output)

Outputbased 

emission 

limits 

(lb per 

Mwh)

16. Units designed to burn 

gas 2 (other) gases 

CO 4 ppm corrected to 3 

percent oxygen. 

0.005 0.031 

 HCl 0.0017 lb per MMBtu of 

heat input. 

0.0029 0.018 

 Mercury 7.9E-06 lb per MMBtu 

of heat input. 

1.4E-05 8.3E-05 

 PM (or 

TSM) 

0.0067 lb per MMBtu of 

heat input or (2.4E-04 lb 

per MMBtu of heat 

input). 

0.012; or 

(4.0E-04) 

0.070 or 

(0.0025) 
Appendix B 

Output-Based Emission Limits for New Boilers and Process Heaters 
Summary of Calculated Output-Based (MACT Floor) Limits for New Boilers and Process 

Heaters at Major Sources (Units with heat input capacity of 10 million Btu per hour or 

greater) 

Subcategory Pollutant 

MACT (heat inputbased) proposed 

emission limits 

Outputbased 

emission 

limits 

(lb per 

MMBtu of 

steam 

output)

Outputbased 

emission 

limits 

(lb per 

Mwh)

1. Solid fuel HCl 0.022 lb per MMBtu of 

heat input.

0.025A 0.28 

 Mercury 8.60E-07 lb per MMBtu 

of heat input. 

9.4E-07 1.1 E-05 

2. Pulverized coal boilers 

designed to burn 

coal/solid fossil fuel 

CO 9 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.0074 0.092 

 PM (or 

TSM) 

0.0013 lb per MMBtu of 

heat input; or (2.8E-05 

lb per MMBtu of heat 

input). 

0.0013 or 

(2.8E-05) 

0.016 or 

(3.5E-04) 

3. Stokers designed to 

burn coal/solid fossil fuel 

CO 19 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.017 0.20 

 PM (or 

TSM) 

0.028 lb per MMBtu of 

heat input; or (2.2E-05 

lb per MMBtu of heat 

input). 

0.028; or 

(3.0E-05) 

0.35 or 

(2.7E-04) 

4. Fluidized bed units 

designed to burn 

coal/solid fossil fuel 

CO 17 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.015 0.18 

 PM (or 

TSM) 

0.0011 lb per MMBtu of 

heat input; or (1.7E-05 

lb per MMBtu of heat 

input). 

0.0012; or 

(1.8E-05A) 

0.014 or 

(2.1E-04) 

5. Stokers/sloped 

grate/others designed to 

burn wet biomass fuel 

CO 590 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.56 6.5 
Subcategory Pollutant 

MACT (heat inputbased) proposed 

emission limits 

Outputbased 

emission 

limits 

(lb per 

MMBtu of 

steam 

output)

Outputbased 

emission 

limits 

(lb per 

Mwh)

 PM (or 

TSM) 

0.029 lb per MMBtu of 

heat input; or (2.6E-05 

lb per MMBtu of heat 

input). 

0.034; or 

(2.7E-05) 

0.41 or 

(3.7E-04) 

6. Stokers/sloped 

grate/others designed to 

burn kiln-dried biomass 

fuel 

CO 250 ppm by volume on a 

dry basis corrected to 3 

percent oxygen. 

0.23A 2.8 

 PM (or 

TSM) 

0.32 lb per MMBtu of 

heat input; or (4.0E-03 

lb per MMBtu of heat 

input). 

0.37; or 

(0.0042) 

4.5 or 

(0.056) 

7. Fluidized bed units 

designed to burn 

biomass/bio-based solids 

CO 230 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.22 2.6 

 PM (or 

TSM) 

0.0098 lb per MMBtu of 

heat input; or (4.2E-05 

lb per MMBtu of heat 

input). 

0.012; or 

(5.4E-05) 

0.14 or 

(5.9E-04) 

8. Suspension burners 

designed to burn 

biomass/bio-based solids 

CO 58 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.046 0.64 

 PM (or 

TSM) 

0.051 lb per MMBtu of 

heat input; or (0.0011 lb 

per MMBtu of heat 

input). 

0.052; or 

(0.0012) 

0.71 or 

(0.016) 

9. Dutch Ovens/Pile 

burners designed to burn 

biomass/bio-based solids 

 CO 810 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average. 

0.89A 8.9 

 PM (or 

TSM) 

0.036 lb per MMBtu of 

heat input; or (4.1E-05 

lb per MMBtu of heat 

input). 

0.050A; or 

(5.5E-05) 

0.51 or 

(5.8E-04) 
Subcategory Pollutant 

MACT (heat inputbased) proposed 

emission limits 

Outputbased 

emission 

limits 

(lb per 

MMBtu of 

steam 

output)

Outputbased 

emission 

limits 

(lb per 

Mwh)

10. Fuel cell units 

designed to burn 

biomass/bio-based solids 

 CO 210 ppm by volume on a 

dry basis corrected to 3 

percent oxygen. 

0.29 2.3 

 PM (or 

TSM) 

0.011 lb per MMBtu of 

heat input; or (4.9E-05 

lb per MMBtu of heat 

input). 

0.03; or 

(8.6E-05) 

0.16 or 

(6.9E-04) 

11. Hybrid suspension 

grate boiler designed to 

burn biomass/bio-based 

solids 

 CO 1,500 ppm by volume 

on a dry basis corrected 

to 3 percent oxygen, 3-

run average. 

1.8 17 

 PM (or 

TSM) 

0.026 lb per MMBtu of 

heat input; or (4.9E-04 

lb per MMBtu of heat 

input). 

0.033; or 

(6.2E-04) 

0.37 or 

(0.0069) 

12. Units designed to burn 

liquid fuel 

HCl 0.0012 lb per MMBtu of 

heat input. 

0.0013 0.017 

 Mercury 4.9E-07 lb per MMBtu 

of heat input. 

5.4E-07 6.8E-06 

13. Units designed to burn 

heavy liquid fuel 

CO 10 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average; average). 

0.0091A 0.11 

 PM 0.013 lb per MMBtu of 

heat input. 

0.015 0.18 

14. Units designed to burn 

light liquid fuel 

CO 3 ppm by volume on a 

dry basis corrected to 3 

percent oxygen. 

0.0031 0.033 

 PM 0.0011 lb per MMBtu of 

heat input for light 

liquid. 

0.0015 0.016 

15. Units designed to burn 

liquid fuel located in noncontinental States and 

territories 

CO 18 ppm by volume on a 

dry basis corrected to 3 

percent oxygen, 3-run 

average based on stack 

test. 

0.017A 0.20 

 PM 0.0080 lb per MMBtu of 

heat input. 

0.0087 0.11 
Subcategory Pollutant 

MACT (heat inputbased) proposed 

emission limits 

Outputbased 

emission 

limits 

(lb per 

MMBtu of 

steam 

output)

Outputbased 

emission 

limits 

(lb per 

Mwh)

16. Units designed to burn 

gas 2 (other) gases 

CO 4 ppm by volume on a 

dry basis corrected to 3 

percent oxygen. 

0.0050 0.031 

 HCl 0.0017 lb per MMBtu of 

heat input. 

0.0029 0.018 

 Mercury 7.9E-06 lb per MMBtu 

of heat input. 

1.4E-05 8.3E-05 

 PM (or 

TSM) 

0.0067 lb per MMBtu of 

heat input; or (2.4E-04 

lb per MMBtu of heat 

input). 

0.012 or 

(4.0E-04) 

0.070 or 

(0.0025) 

A Calculated output-based limit for new sources was less-stringent than output-based limit for 

existing sources for the same subcategory. Output-based limit was defaulted to the existing 

source limit. 
APPENDIX C 

BEST PERFORMING UNITS AND HEAT RATE DATA 

(See Excel Spreadsheet) 
APPENDIX D 

OUTPUT INFO FOR BEST PERFORMING UNITS 

(See Excel Spreadsheet)