Technical Support Document 

Additional Threshold Analysis 

Greenhouse Gas Tailoring Rule 

Air Quality Policy Division 

Office of Air Quality Policy and Standards 

U.S. Environmental Protection Agency 

October 12, 2011 
i 

Table of Contents

Page

1. Purpose...................................................................................................................................... 1

2. Overview ................................................................................................................................... 1

3. Step 3 Emissions-based Thresholds Analysis Methodology ................................................. 2

3.1 Threshold Levels .................................................................................................................. 2

3.2 Greenhouse Gases ................................................................................................................ 2

3.3 Source Sectors ...................................................................................................................... 3

3.4 Potential to Emit Methodology ............................................................................................ 4

3.5 New and Modified Sources .................................................................................................. 4

3.6 Sectors and Subsectors Unaffected by Thresholds Between 50,000 and 100,000 .............. 5

3.7 Thresholds Analysis-Thresholds Between 50,000 and 100,000 tons CO2e ......................... 6

4. Electricity Generating Sector .................................................................................................. 8

5. Industrial Sector..................................................................................................................... 10

5.1 Industrial Sector Overview ................................................................................................ 10

5.1.1 Data Sources ............................................................................................................... 12

5.1.2 Potential to Emit Methodology ................................................................................... 12

5.1.3 Methodology for New Units ....................................................................................... 13

5.2 Ammonia Production ......................................................................................................... 13

5.3 Cement Production............................................................................................................. 14

5.4 Electronic Production ......................................................................................................... 15

5.5 Food Processing ................................................................................................................. 17

5.6 Glass Manufacturing .......................................................................................................... 18

5.7 Hydrogen Production ......................................................................................................... 19

5.8 Iron and Steel Production................................................................................................... 20

5.9 Lead Production ................................................................................................................. 22

5.10 Lime ................................................................................................................................. 23

5.11 Nitric Acid Production ..................................................................................................... 24

5.12 Petrochemical Production ................................................................................................ 25

5.13 Petroleum Refineries ........................................................................................................ 26

5.14 Pulp and Paper Manufacturing......................................................................................... 27

5.15 Unspecified Industrial Stationary Combustion Sources .................................................. 29
ii 

Table of Contents (cont.)

Page

6. Energy Sector ......................................................................................................................... 30

6.1 Oil and Gas Systems .......................................................................................................... 30

6.2 Underground Coal Mining ................................................................................................. 31

7. Waste Sector ........................................................................................................................... 33

7.1 Landfills ............................................................................................................................. 33

7.2 Municipal Solid Waste Combustors .................................................................................. 35

8. Commercial Stationary Fuel Combustion ........................................................................... 37

9. Residential Stationary Combustion...................................................................................... 40

9.1 Multi-Family Residential Buildings .................................................................................. 40

References .................................................................................................................................... 46

Appendix A .................................................................................................................................. 49

Appendix B .................................................................................................................................. 50
1 

Technical Support Document for Additional Threshold Analysis 

Greenhouse Gas Tailoring Rule 

1. Purpose 

In the final Tailoring Rule, EPA established an enforceable commitment to propose or 

solicit comment on a third step of the phase-in approach. This Technical Support Document 

(TSD) provides the background information used to support EPA's Step 3 decision process for 

evaluating potential greenhouse gas (GHG) emission thresholds between 50,000 and 100,000 

tons per year for New Source Review (NSR) and Title V permitting. The analysis conducted 

provides estimates of the number of existing and new facilities (e.g., industrial plant, commercial 

building) that would exceed differing GHG emission threshold levels, summarizing the results 

for each sector. The results of this analysis served as one of the fundamental bases for evaluating 

administrative burdens at different permitting thresholds to address administrative necessity 

concerns. 

2. Overview 

The Step 3 threshold analysis relies on the analysis conducted to support the threshold 

decisions in the final Tailoring Rule, which is documented in the Technical Support Document 

for Greenhouse Gas Emissions Thresholds Evaluation, EPA-HQ-OAR-2009-0517-19158 

(March 29, 2010). 

 The analysis developed information on the number of affected facilities at both the 

current permitting major source thresholds (generally, 100 tons per year for Title V and 100 or 

250 tons per year for PSD depending on the source category classification) and at alternative 

higher thresholds. An affected facility would be one whose annual GHG emissions equal or 

exceed the emissions threshold being evaluated. 

 Also in the original analysis, eight threshold levels of GHG emissions ranging from 100 

to 100,000 tons per year carbon dioxide equivalents (CO2e) were evaluated. Some of these 

thresholds (e.g., 25,000 tons per year CO2e) were the same as those considered in previous 

studies and in support of EPA's GHG Reporting Program (GHGRP) (74 FR 16447-731). One 

key difference between the emissions data developed for the permit threshold analysis and that 

developed to support the GHGRP is that the permit threshold analysis is based on a facility's 

"potential to emit" (PTE), while the GHGRP is based on "actual" emissions (i.e., a facility’s 

actual emissions in a given year). PTE is defined as the maximum capacity of a stationary 

source to emit a pollutant under its physical and operational design, including certain legal 

limitations on such things as emissions or hours of operation. The NSR and Title V programs 

both use PTE for defining major sources, where the end result is generally that more facilities 

will exceed a given threshold on a PTE basis than on an actual basis. This is an important 

differentiation for both evaluating the thresholds under this proposed rule and comparing the 

results to other threshold analyses, such as the supporting data for EPA's GHGRP. 
2 

In performing the permitting threshold analysis, EPA made use of earlier analyses from 

the development of emission thresholds for the GHGRP, or used the same data sources when 

additional analyses were required. EPA did not conduct primary research, instead relying on 

published research and publicly available government data, including the Agency’s own eGRID 

database of electric generating source emissions, U.S. Census Bureau Economic and Housing 

data, and Energy Information Agency (EIA) data on energy consumption. 

 Although the primary focus of the analysis was on the potential administrative burden 

associated with different GHG permitting emission levels as represented in terms of number of 

facilities potentially subject to permitting, information on GHG emissions from affected facilities 

was also developed to assess the relative coverage of national stationary source GHG emissions 

at the different threshold levels. Although EPA did not use the environmental impact associated 

with the different GHG permitting levels as the basis for the GHG thresholds in the rule, the 

information on national emissions coverage provides a useful measure of the potential scope of 

the proposed alternative thresholds, their coverage of key GHG emission source categories, and 

their promotion, if any, of the environmental purposes of the PSD and Title V programs. This is 

true as well for the additional Step 3 analysis of annual GHG thresholds between 50,000 

and100,000 tons CO2e. 

3. Step 3 Emissions-based Thresholds Analysis Methodology

3.1 Threshold Levels 

 As noted above, in the analysis for the final Tailoring Rule EPA evaluated eight different 

PTE thresholds between 100 tons per year CO2e and 100,000 tons per year CO2e, including 

50,000 tons per year CO2e. For the Step 3 analysis, EPA refined its previous analysis by 

evaluating eight additional thresholds between 50,000 and 100,000 tons per year CO2e in 5,000 

ton increments (55,000 through 95,000 tons per year CO2e). 

3.2 Greenhouse Gases 

EPA evaluated emissions of GHGs that are directly emitted by human activities at the 

eight threshold levels. Table 3-1 indicates which GHGs were evaluated. For purposes of this 

analysis, emissions were evaluated on a CO2e basis. CO2e normalizes the different heat trapping 

capacities of the various GHGs to that of CO2. A quantity of a GHG is converted to a CO2e 

basis by multiplying the mass of the compound emitted by its Global Warming Potential (GWP). 

The GWP is a metric that incorporates both the heat-trapping ability and atmospheric lifetime of 

each GHG relative to CO2. 
3 

Table 3-1 

Major GHGs Directly Emitted by Human Activities 

Greenhouse Gas 

Chemical Formula 

or Acronym 

Global Warming 

Potential (GWP)* 

Carbon dioxide CO2 1 

Methane CH4 21 

Nitrous oxide N2O 310 

Perfluorocarbons PFCs Varies by compound 

Hydrofluorocarbons HFCs Varies by compound 

Sulfur hexafluoride SF6 23,900 

* EPA has chosen to use GWPs from the Intergovernmental Panel on Climate 

Change (IPCC) Second Assessment Report (SAR) published in 1996. For 

fluorinated compounds that are not listed in the SAR, EPA is using the most 

recent available GWPs from either the IPCC Third Assessment Report 

(2001) or Fourth Assessment Report (2007). Table A-1 in the GHGRP rule 

contains more specific information about the GWP of specific GHGs. 

 Each sector covered in this document includes a description of the GHGs evaluated. 

Because CO2 constitutes over 99% of GHG emissions from fossil fuel combustion, the threshold 

analyses for stationary fossil fuel combustion were often simplified by excluding CH4 and N2O 

emissions. 

3.3 Source Sectors 

EPA evaluated the same stationary source types with direct GHG emissions as are found 

in the GHGRP. The GHGRP source categories were based on a comprehensive review of all 

U.S. source categories with GHG emissions, and include those with the most significant GHG 

emissions. The stationary sources can be grouped in these sectors: 

● Electricity Generation (facilities with fossil fuel-fired electric generating units); 

● Industry (range of industries with process and combustion GHG emissions); 

● Energy (oil and gas extraction, transport, and processing; underground coal mining); 

● Waste Treatment (landfills and municipal solid waste incinerators); 

● Agriculture (stationary fuel combustion); 

● Commercial (stationary fuel combustion); and 

● Residential (stationary fuel combustion). 

 
4 

 Some direct emission source types included in the GHGRP were not included in the PTE 

analysis because their GHG emissions were primarily “fugitive”. Fugitive emissions are 

emissions that are not released, or could not be reasonably released, through a stack or vent. 

Excluded fugitive emissions sources include: 

● Electrical equipment SF6 emissions; 

● Wastewater treatment plants not associated with one of the 28 listed PSD source 

categories (combustion is captured in the commercial sector analysis); and 

● Agricultural manure management. 

3.4 Potential to Emit Methodology 

As noted above, PTE is the amount of emissions that can be emitted from a source 

operating at full capacity. The annual PTE is based on operation at full equipment capacity -- 24 

hours per day, 365 days per year (8,760 hours per year). For example, if a boiler has a maximum 

rated heat input capacity of ten million Btu (mmBtu) per hour, the annual PTE for that boiler is 

the amount of emissions from burning 87,600 million Btu of fuel: 

10 mmBtu/hr x 8,760 hrs/yr = 87,600 mmBtu/yr 

Capacity information and annual GHG emissions were available for some of the source 

categories from analyses performed to support the GHGRP. In instances where the supporting 

analyses had already calculated GHG emissions on a full capacity basis, EPA directly used those 

estimates as PTE estimates. Alternatively, some data from the supporting analysis estimated 

actual annual emissions using a baseline year. If capacity and baseline year production 

information was provided in the supporting data, EPA adjusted the source category’s actual 

emissions estimate by the ratio of annual capacity to baseline production to estimate PTE. If 

capacity information was not available, EPA used capacity factors from other data sources to 

adjust actual emission estimates to PTE estimates. These capacity factors add varying 

uncertainty to the PTE estimate. Detailed descriptions of the different PTE calculation 

methodologies are included in the source descriptions in the following sections. 

 Although PTE estimates account for removal by pollution control equipment, such 

removal is relevant in only a few cases (e.g., thermal oxidation of HPCs and CH4). Also, 

fugitive emissions were included in the PTE estimates only if the source was one of the 28 listed 

PSD source categories. For example, fugitive CH4 emissions were not included in CH4 or CO2e 

emissions from oil and gas processing plants but were included for iron and steel plants. 

3.5 New and Modified Sources 

The source population data from the analyses supporting the GHGRP as well as other 

data sources provide information on existing sources and their emissions. The PSD and NSR 

program construction permit requirements, however, apply to new or modified sources. 
5 

The general approach for new sources was to apply growth rates in the number of units or 

facilities in a source category to the number of existing facilities at the different thresholds. 

Growth rates were available from a variety of sources including U.S. Census Bureau Economic 

data, EIA energy survey data, and various EPA regulatory impact analyses (RIA) and 

information collection requests (ICR) requiring source population estimates. In some cases, 

there was sufficient information to distribute new sources to different thresholds based on 

emission information specific to the new sources (e.g., electric generating, municipal solid waste 

combustors, and commercial stationary fuel combustion). Where sufficient information was not 

available, EPA assumed the same size and threshold distribution for new units as for existing 

units. For example, if the annual growth rate in a category was 1%, the number of existing 

facilities above a threshold was multiplied by the fractional growth rate to estimate the number 

of new facilities at that threshold per year. 

EPA did not develop estimates for modifications as part of this threshold study, but did 

do so under another technical support document (TSD) for the original threshold burden analysis 

(EPA-HQ-OAR-2009-0517-19157). 

3.6 Sectors and Subsectors Unaffected by Thresholds Between 50,000 and 100,000 

Certain sectors and subsectors are not affected by threshold changes between 50,000 and 

100,000 tons because all of the facilities in the sector or subsector are either below 50,000 tons 

per year or above 100,000 tons per year. Tables 3-2 and 3-3 provide counts of stationary source 

facilities in these unaffected sectors and subsectors along with the actual GHG emissions from 

these facilities. These GHG emissions are expressed in teragrams (Tg), which is equivalent to a 

million metric tons. SI units were used for the covered emissions to be consistent with the U.S. 

GHG Inventory and the GHGRP. The analysis discussion and complete data for the sectors and 

subsectors are provided in the Technical Support Document for Greenhouse Gas Emissions 

Thresholds Evaluation, EPA-HQ-OAR-2009-0517-19158 (March 29, 2010). 

Table 3-2 

Categories with No Sources Captured by the 50,000 and 100,000 Tons CO2e Thresholds 

Sector/Source Category 

Highest 

Threshold 

Exceeded by a 

Source 

Number of 

Existing 

Sources 

Number of 

New Facilities 

Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

Agriculture/Stationary 

Combustion 

250 37,351 299 0.5 

Residential/ Single Family 

Stationary Combustion 

250 45,350 515 1.7 
6 

Table 3-3 

Categories with All Sources Captured by the 50,000 and 100,000 Tons CO2e Thresholds 

Sector/Source Category 

Number of 

Existing Sources 

Number of 

New Facilities 

Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

Industrial /Adipic Acid Production 4 0 9.3 

Industrial/Aluminum Production 15 0 4.0 

Industrial/Ferroalloy Production 9 0 1.7 

Industrial/ HCFC-22 Production 3 0 13.8 

Industrial/Magnesium Production 9 0 2.8 

Industrial/Phosphoric Acid Production 14 0 3.8 

Industrial /Silicon Carbide Manufacturing 1 0 0.1 

Industrial/Soda Ash Production 5 0 3.1 

Industrial/Titanium Dioxide 8 0 3.7 

Industrial/Zinc Production 5 0 0.8 

Total 73 0 43.2 

3.7 Thresholds Analysis-Thresholds Between 50,000 and 100,000 tons CO2e 

Table 3-4 indicates those sectors and subsectors affected by changes in thresholds 

between 50,000 and 100,000. These sectors were the focus of the Step 3 threshold analysis. The 

sections following the table describe the sector specific analysis performed for each sector, and 

resulting counts of affected stationary source facilities, new facilities, and the amount of actual 

GHG emissions covered at each of the additional PTE thresholds. Results for all of these sectors 

are identified in Appendix A, and supporting data are listed in Appendix B. 
7 

Table 3-4 

Source Categories Affected by Additional Thresholds Between 50,000 and 100,000 

Sector/Source Category 

50,000 Tons/Year 

PTE Threshold 

100,000 Tons/Year 

PTE Threshold 

Number of 

Existing 

Sources 

CO2e 

Emissions 

Covered 

(Tg per year) 

Number of 

Existing 

Sources 

CO2e 

Emissions 

Covered 

(Tg per year)

Electricity Generation/Electricity 

Generating Units 

1,911 2373.1 1,721 2371.9 

Industrial/Ammonia Manufacturing 24 14.5 22 14.5 

Industrial/Cement Production 107 86.8 106 86.7 

Industrial/Electronics Manufacturing 54 5.1 22 3.4 

Industrial/Food Processing 10 0.6 0 0 

Industrial/Glass Production 21 1.2 3 0.4 

Industrial/Hydrogen Production 38 14.9 32 14.4 

Industrial/Iron and Steel Production 116 84.8 113 84.7 

Industrial/Lead Production 12 0.8 1 0.1 

Industrial/Lime Manufacturing 66 26.5 60 26.2 

Industrial/Nitric Acid Production 43 17.7 42 17.7 

Industrial/Petrochemical Production 94 54.7 91 54.5 

Industrial/Petroleum Refineries 137 204.5 129 204.0 

Industrial/Pulp and Paper Manufacturing 422 57.7 410 57.5 

Industrial/Unspecified Industrial 

Stationary Combustion (Other 

Manufacturing and Industrial Facilities) 

3,272 206.9 958 145.1 

Energy/Oil and Natural Gas Systems 1,045 56.9 387 32.8 

Energy/Underground Coal Mines 78 32.8 55 31.2 

Waste/Landfills 1,684 92.3 967 72.7 

Waste/Municipal Waste Combustors 67 6.1 40 5.0 

Commercial/Stationary Fuel Combustion 600 6.0 51 1.0 

Residential/Multi-family Fuel Combustion 20 0.1 0 0.0 
8 

4. Electricity Generating Sector 

 The electricity generating sector consists of facilities with fossil fuel fired electric 

generating units that rely on fuel combustion for their energy source and that have a North 

American Industry Classification System (NAICS) code prefix of 22 (Utilities). 

Data Sources 

EPA's eGRID database (2006) was used to estimate the PTE of electricity generating 

facilities and counts of units above the different emission thresholds. eGRID includes year 2004 

characteristics, operating information, and annual emissions (including CO2) for U.S. facilities 

that have a generation capacity greater than one MW and sell electric power to the grid. 

Potential to Emit 

 A facility's PTE was estimated based on the eGRID generator table, which draws from 

the 2004 EIA Form 860 database, and provides prime mover, generator nameplate capacity, and 

primary energy source (fuel type) for each generator down to 0.1 MW. To calculate PTE, EPA 

combined the nameplate capacity and primary fuel for each of the fossil-fired units with average 

fuel-based prime mover heat rates (Btu/kWh) published by EIA (EIA, 2007). 

Table 4-1 

EGU Prime Mover Heat Rates 

(EIA Electric Power Annual, Table A7, 2007) 

Prime Mover Fuel Average Heat Rate (Btu/kWh) 

Steam turbine 

Coal 10,114 

Gas 10,466 

Oil 10,400 

Simple 

combustion turbine 

Gas 11,459 

Oil 13,216 

Combined cycle 

combustion turbine 

Gas 7,445 

Oil 11,015 

Internal 

combustion engine 

Gas 9,923 

Oil 10,149 

 The eGRID database includes cogeneration plants and generating units at industrial 

plants that primarily supply electric power and steam to a host facility. EPA eliminated these 

units from the electric generation facility population based on their NAICS code; thus, the only 

facilities included were those with a NAICS code prefix of 22 (Utilities). 
9 

 The generator-nameplate-heat-rate approach potentially underestimates PTE for 

cogeneration plants, where a portion of the burner heat input provides useful thermal energy in 

addition to electric output. This potential to underestimate PTE affects 321 of the 2,237 facilities 

evaluated, or 14% of those facilities. 

 Fuel combustion was the only source of GHG emissions considered for the electricity 

generating sector. Using eGRID and EIA data EPA calculated a maximum annual fuel heat 

input based on 8,760 hours of operation for the combustors associated with the generator. This 

calculated maximum annual heat input was used with fuel combustion CO2 emission factors 

from the GHGRP for the primary fuel to calculate the facility PTE. EPA did not estimate the 

much less significant CH4 and N2O contribution from fuel combustion. The calculations covered 

10,487 fossil fuel-fired generators with nameplate capacities down to 0.1 MW or 100,000 kW. 

 Fossil fuel-fired steam electric plants with heat input greater than 250 mmBtu/hr are one 

of the 28 listed PSD source categories that include fugitive emissions when calculating PTE. 

However, EPA did not evaluate fugitive CH4 emissions from coal piles at these facilities. The 

CO2 PTE from combustion alone for this size facility is about 225,000 tons per year, which far 

exceeds the emission thresholds in this analysis without accounting for the contribution of 

fugitive CH4. 

New Units 

 The eGRID generator table includes an online year field. To determine the number of 

new units per year at different thresholds, EPA counted generators online each year and totaled 

the emissions associated with those generators at the facility level over the 15-year period from 

1990 – 2004. EPA determined the number of facilities over the different PTE thresholds and 

averaged over the 15 years to arrive at the number of new or modified facilities per year. 

Threshold Summary 

 The table below shows the facilities and emissions covered at the different emission 

thresholds based on the described methodology. There were a total of 2,237 facilities in the 

electric generation population. Almost all emissions (99.9%), and about 75% of facilities, are 

covered at the highest 100,000 ton PTE threshold. 
10 

Table 4-2 

CO2e Threshold Summary Results -- Electricity Generating Sector 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 1,911 64 2,373.1 

55,000 1,890 64 2,372.9 

60,000 1,865 63 2,372.8 

65,000 1,838 63 2,372.6 

70,000 1,822 62 2,372.6 

75,000 1,806 62 2,372.5 

80,000 1,789 61 2,372.4 

85,000 1,778 61 2,372.4 

90,000 1,763 61 2,372.4 

95,000 1,746 60 2,372.2 

100,000 1,721 60 2,371.9 

5. Industrial Sector 

The industrial sector consists of establishments engaged in the mechanical, physical, or 

chemical transformation of materials, substances, or components into new products, and 

specifically includes businesses classified by NAICS in Sectors 31 – 33. Industrial source GHGs 

result from manufacturing processes as well as combustion processes. Because there is a great 

deal of variability within the sector, this technical support document includes industry-specific 

discussions after a general sector overview. 

5.1 Industrial Sector Overview 

EPA identified the 23 industrial sectors with significant GHG emissions in the GHGRP. 

These sectors are listed in Table 5-1. 
11 

Table 5-1 

Industrial Source Categories and GHG Emissions 

NAICS Code Industrial Source Category CO2 CH4 N2O SF6 HFC PFC 

325199 Adipic Acid Production X X 

331312 Aluminum Production X X 

325311 Ammonia Production X 

327310 Cement Production X 

334 Electronics Manufacturing X X X X 

331112 Ferroalloy Production X X 

3116 Food Processing X 

327 Glass Production X 

325120 HCFC-22 Production X X 

 Hydrogen Production X 

331111 Iron and Steel Production X X 

3314 Lead Production X 

327410 Lime Manufacturing X 

3314 Magnesium Production X X 

325311 Nitric Acid Production X X 

3251 Petrochemical Production X X 

324110 Petroleum Refineries X X 

325312 Phosphoric Acid Production X 

3221 Pulp and Paper Manufacturing X 

327910 Silicon Carbide Production X X 

325181 Soda Ash Manufacturing X 

325188 Titanium Dioxide Production X 

3314 Zinc Production X 

In addition, there are a large number of industrial establishments across all industrial 

sectors that emit less significant amounts of GHGs (primarily CO2) from stationary source fuel 

combustion. Combustion emissions from these establishments were analyzed under the 

Unspecified Industrial Stationary Combustion source category. 

 
12 

5.1.1 Data Sources 

EPA relied upon several primary data sources to prepare the permit threshold analysis, 

and consulted GHGRP analyses of the 23 industrial sectors for which combustion, process and 

fugitive emissions were significant. These documents can be found in Supporting Data for 

Threshold Analysis Subpart E-W, Greenhouse Gas Mandatory Reporting Rulemaking, March 10, 

2009, EPA-HQ-OAR-2008-0508 (Supporting Data for Threshold Analysis Subpart E-W). The 

TSDs contain industry-specific analyses of process, fugitive, and combustion emissions for 

industries. Supporting analyses used to prepare the TSDs are found in entries 0046.7 and 0046.8 

of the GHGRP docket (EPA-HQ-OAR-2008-0508-0046.7 and EPA-HQ-OAR-2008-0508-

0046.1). These emissions estimate details were helpful in breaking down TSD emission 

estimates to compare facility-specific emissions against the additional threshold levels 

considered in the original permit threshold analysis, including 100, 250, 5,000, and 50,000 tons 

per year. 

Combustion emissions analyses for the Unspecified Industrial Stationary Combustion 

sectors drew data from the 2002 Manufacturing Energy Consumption Survey (MECS) and the 

U.S. Census Bureau's 2002 Economic Census. MECS is an EIA survey of manufacturing and 

industrial energy uses and costs (EIA, 2007). Data is collected by the manufacturing 

establishment through mailed questionnaires. The 2002 MECS data reflect responses accounting 

for approximately 98% of the manufacturing payroll and reports separate energy use estimates 

for 48 NAICS industrial sector groups. The MECS data provide the amount of fuel burned in 

2002 by sector on an employment basis. The 2002 Economic Census data provide the number of 

establishments sorted by three-digit NAICS code and disaggregated into specific size categories 

based on employment (U.S. Census, 2004). 

 

5.1.2 Potential to Emit Methodology 

The GHGRP TSDs for the specific industrial source categories listed in Table 6 generally 

included facility GHG emission estimates at facility capacity or at actual production levels. If 

the estimates were made at capacity, no adjustments were needed for PTE beyond conversion 

from metric to short tons. If estimates were of actual emissions at less than full capacity, the 

actual emissions were adjusted to reflect capacity based on facility specific capacity, if available. 

Where capacity information was not available to estimate PTE, the analyses applied 

utilization rates from the Industrial Production and Capacity Utilization, Federal Reserve 

Statistical Release G-17, to adjust actual emissions to determine PTE emissions. These 

utilization rates are prepared quarterly with annual revisions and are published on the web 

(http://www.federalreserve.gov/releases/g17). The main data source for the industrial production 

and capacity utilization rates is the U.S. Census Bureau's Census of Manufactures. Data 

introduced from other Census Bureau publications include the Census of Services and the 

Services Annual Survey (for publishing) and selected Current Industrial Reports. Additional 

government source data include new annual data on minerals from the U.S. Geological Survey 

(USGS) and updated deflators from the Bureau of Economic Analysis (BEA). In addition, the 

annual revisions include monthly production estimates that reflect updated seasonal factors and 
13 

the inclusion of monthly source data that became available (or were revised) after the closing of 

the regular four-month reporting window. 

For the general unspecified stationary combustion category, EPA assumed a capacity 

factor of 50% to adjust actual emissions to PTE. 

5.1.3 Methodology for New Units 

 To determine the number of new units per year, EPA compared the number of 

establishments by three-digit NAICS code in 1998 to the number of establishments by three-digit 

NAICS code in 2002 and determined an average annual growth rate for each three-digit NAICS 

code. The growth rates were applied to each threshold count to determine the number of annual 

new establishments per industry per threshold. If the growth rate was determined to be negative, 

EPA assumed that no new establishments would be added; however, establishments were not 

reduced to reflect negative growth rates. EPA also supplemented these growth rates with agency 

estimates of expected new sources from various ICRs and RIAs. 

5.2 Ammonia Production 

 EPA reviewed the Supporting Data for Threshold Analysis Subpart E-W (EPA-HQOAR-2008-0508-0046.7) to determine actual emissions and calculate the PTE for 24 ammonia 

plants in operation. The analysis spreadsheet details CO2 actual emission calculations for each 

plant based on ammonia production and urea production, and CO2, CH4, and N2O emission 

calculations for stationary fuel combustion based on 2006 data. For purposes of permit threshold 

analysis, the CH4 and N2O emissions from combustion were not significant. 

Potential to Emit 

Capacity information in the spreadsheet is based on the engineering design capacity 

adjusted for 340 days per year of effective production capability, using information provided by 

the USGS. The PTE estimates were made by multiplying the actual emission estimates by the 

ratio of annual ammonia capacity to annual ammonia production adjusted to 365 days a year of 

operation instead of 340. EPA assumed that ratio also held for stationary combustion units at the 

plant. 

New Units 

EPA assumed that no new plants would be constructed for this sector. 
14 

Threshold Summary 

Table 5-2 

CO2e Threshold Summary -- Ammonia Production 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 24 0 14.5 

55,000 24 0 14.5 

60,000 24 0 14.5 

65,000 24 0 14.5 

70,000 24 0 14.5 

75,000 23 0 14.5 

80,000 22 0 14.5 

85,000 22 0 14.5 

90,000 22 0 14.5 

95,000 22 0 14.5 

100,000 22 0 14.5 

5.3 Cement Production 

The second largest source of industrial CO2 emissions in the United States is processrelated CO2 emissions from cement production. Cement production is done in two stages. The 

first stage is clinker production, in which raw materials (primarily limestone) are heated to 

induce calcination and produce lime. Lime reacts with silica-containing materials and iron ore 

and aluminum to form clinker. During the process, CO2 is generated as a byproduct and released 

to the atmosphere. In addition, some of the clinker raw materials form partially or fully 

calcinated cement kiln dust instead of forming clinker, resulting in additional process-related 

CO2 emissions. In the second stage of the production process, the clinker is ground and mixed 

with gypsum and other materials to make cement. 

Potential to Emit 

The Technical Support Document for Process Emissions from Cement: Proposed Rule 

for Mandatory Reporting of Greenhouse Gases (EPA-HQ-OAR-2008-0508-0008) identifies 107 

cement facilities in the United States, 106 of which exceed all permit thresholds for CO2. Based 

Table 4.1 of the TSD indicates that the one facility that did not exceed the 100,000 tons per year 

threshold has a clinker capacity of about 102,000 metric tons per year, and emissions of about 

90,000 metric tons per year. On a short ton basis this facility would be very close to the 100,000 
15 

tons/year threshold, at least 99,000 tons per year. For this analysis, EPA kept this facility below 

100,000 tons per year but over 95,000 tons per year CO2e PTE. 

New Units 

As growth for the industrial sector was estimated at 0.4%, no additional facilities were 

included in this analysis. 

Threshold Summary 

Table 5-3 

CO2e Threshold Summary -- Cement Production 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 107 0 86.8 

55,000 107 0 86.8 

60,000 107 0 86.8 

65,000 107 0 86.8 

70,000 107 0 86.8 

75,000 107 0 86.8 

80,000 107 0 86.8 

85,000 107 0 86.8 

90,000 107 0 86.8 

95,000 107 0 86.8 

100,000 106 0 86.7 

5.4 Electronic Production 

The Technical Support Document for Process Emissions from Electronics Manufacture 

(Semiconductors, MEMs, Liquid Crystal Displays, and Photovoltaics) (EPA-HQ-OAR-2008-

0508-0009) examined emissions of high GWP gases for semiconductor and related industry 

plants. Emissions from stationary fuel combustion were not included in the source category 

analysis, but were instead captured by the unspecified industrial stationary combustion analysis. 

EPA has followed this approach here as well. 

Approximately one million metric tons of SF6 as CO2e were emitted from the 

semiconductor industry in 2006 (Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 – 

2007). This is equivalent to 46 short tons of SF6. The semiconductor industry uses multiple 
16 

long-lived fluorinated gases in plasma etching and plasma enhanced chemical vapor deposition 

(PECVD) processes to produce semiconductor products. These include PFCs, which are also 

used as heat transfer fluids. Approximately 3.5 million metric tons of PFCs as CO2e were 

emitted from the semiconductor industry in 2006 (Inventory of U.S. Greenhouse Gas Emissions 

and Sinks: 1990 – 2007). 

Table 5-4 

Electronic Production PFC Emissions 

Semiconductor PFC 

2006 CO2e Emissions

(million mtons) PFC GWP 

2006 PFC Emissions 

(tons) 

CF4 1.2 6,500 204 

C2F6 2.2 9,200 264 

C4F8 0.1 8,700 13 

Total 3.5 -- 481 

Potential to Emit 

The Federal Reserve capacity utilization factor for the electronics industry in 2006 was 

79.8%. Based on this capacity utilization factor, the PTE of all semiconductor plants combined 

is an estimated 56 tons of SF6 and 600 tons of PFC. 

 EPA identified 216 facilities in the semiconductor-electronics sector. Of these, the 

largest facility emitted 6% of total semiconductor emissions on a CO2e basis (includes nonPFCs), which is a maximum of 30 tons of PFC. On a PTE basis, the largest facility would emit 

36 tons, based on an assumption that the industry capacity is distributed similarly to emissions. 

Therefore, no facility exceeds 100 tons per year on an actual or PTE basis for PFC. 

Facility stationary fuel combustion emissions are not included in the threshold 

comparisons for the industry. 

New Units 

As growth for the industrial sector was estimated at -1.8%, no additional facilities were 

included in this analysis. 
17 

Threshold Summary 

 

Table 5-5 

 CO2e Threshold Summary -- Electronics Production 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 54 0 5.1 

55,000 50 0 5.0 

60,000 47 0 4.8 

65,000 41 0 4.6 

70,000 39 0 4.5 

75,000 35 0 4.3 

80,000 35 0 4.3 

85,000 31 0 4.0 

90,000 26 0 3.7 

95,000 24 0 3.6 

100,000 22 0 3.4 

5.5 Food Processing 

Food processing includes meat, poultry and fruit and vegetable processing. Emissions 

derive from combustion and fugitive methane related to wastewater treatment. For purposes of 

this permit threshold analysis, EPA did not consider the fugitive methane from wastewater 

treatment because these are the only GHG emissions from the source category other than 

combustion, and food processing is not a listed PSD source category. Consequently, emissions 

from this subsector considered in this analysis were limited to combustion emissions and were 

calculated using the MECS approach described in Section 5.15. 

Potential to Emit 

EPA used the Federal Reserve's 2004 capacity utilization factor of 79.3% for the food 

industry to calculate PTE emissions. 

New Units 

In addition, new establishments were calculated assuming a continuation of the growth 

rate of 1.2%, as calculated using the methodology described earlier in this document. 
18 

Threshold Summary 

Table 5-6 

CO2 Threshold Summary -- Food Processing 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 10 0 0.6 

55,000 10 0 0.6 

60,000 10 0 0.6 

65,000 10 0 0.6 

70,000 10 0 0.6 

75,000 10 0 0.6 

80,000 10 0 0.6 

85,000 0 0 0 

90,000 0 0 0 

95,000 0 0 0 

100,000 0 0 0 

5.6 Glass Manufacturing 

EPA used the Supporting Data for Threshold Analysis Subpart E-W (EPA-HQ-OAR2008-0508-0046.7) to analyze emissions for permit thresholds from glass manufacturing. 

Annual fuel combustion and glass production are estimated for each plant based on 2004 

estimated plant sales and 2002 MECS energy intensity (energy per sales dollars). The 

spreadsheet shows CO2 emission estimates from industrial processes and stationary fuel 

combustion, as well as CH4 and N2O emission estimates from stationary fuel combustion. 

Potential to Emit 

Plant capacities are not available in the spreadsheet. To estimate PTE, EPA divided the 

actual annual emissions by a capacity utilization factor of 0.50 or 50%. 

New Units 

EPA used an estimated annual growth rate of 0.4% for the nonmetallic mineral product 

manufacturing sector to determine the number of new units for this analysis. 
19 

Threshold Summary 

Table 5-7 

CO2e Threshold Summary -- Glass Manufacturing 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 21 0 1.2 

55,000 18 0 1.1 

60,000 14 0 0.9 

65,000 12 0 0.8 

70,000 11 0 0.8 

75,000 5 0 0.5 

80,000 4 0 0.4 

85,000 4 0 0.4 

90,000 4 0 0.4 

95,000 3 0 0.4 

100,000 3 0 0.4 

5.7 Hydrogen Production 

EPA estimated CO2 emissions from merchant hydrogen production using the process and 

combustion ratio of 8.62 tons of CO2 emissions per ton of hydrogen production. About 95% of 

all hydrogen (not just merchant hydrogen) produced in the United States today is made from 

natural gas via steam methane reforming. In steam methane reforming fueled by natural gas 

combustion, the process and combustion emissions go up the same stack from the 

boiler/reformer unit. EPA has treated all these emissions as process emissions, because the 

emissions are predominately process emissions and the natural gas combustion products are 

emitted from the same stack. 

Potential to Emit 

EPA developed estimates assuming hydrogen production at capacity level. Therefore, no 

adjustment to the emissions estimates is needed to account for PTE emissions. 
20 

New Units 

Based on the industry growth factor of -0.1% for chemical manufacturing, EPA assumed 

that no new plants would be constructed. 

Threshold Summary 

Table 5-8 

CO2 Threshold Summary -- Hydrogen Production 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 38 0 14.9 

55,000 37 0 14.8 

60,000 37 0 14.8 

65,000 37 0 14.8 

70,000 37 0 14.8 

75,000 36 0 14.8 

80,000 36 0 14.8 

85,000 35 0 14.7 

90,000 35 0 14.7 

95,000 35 0 14.7 

100,000 32 0 14.4 

5.8 Iron and Steel Production 

 EPA used the Supporting Data for Threshold Analysis Subpart E-W (EPA-HQ-OAR2008-0508-0046.7) for the GHGRP threshold analysis to determine process and combustion CO2

and process CH4. The iron and steel production source category includes taconite iron ore 

processing facilities, integrated iron and steel making facilities, electric arc furnace (EAF) 

steelmaking facilities that are not located at integrated iron and steel facilities, and coke oven 

facilities that are not located at integrated iron and steel facilities. Table 5-9 indicates facility 

processes and facilities covered in the spreadsheet. 
21 

Table 5-9 

Iron and Steel Processes, Facilities, and Capacity Information 

Iron and Steel Process Number of Facilities Capacity Information 

Basic oxygen furnace (BOF) 18 Yes 

Blast Furnace (BF) 17 Yes 

Sintering 5 Yes 

Coke ovens 18 Yes 

Electric arc furnace (EAF) 92 No 

Taconite furnace 8 Yes 

Integrated steel plant fuel combustion* 19 No 

Coke oven gas combustion* 9 No 

EAF steel plant fuel combustion 92 No 

* Six plants had emissions from coke oven gas combustion was included in integrated steel plant fuel 

combustion. 

Potential to Emit 

The analysis covered 130 plants, and in all cases, except for EAF plants, GHG emissions 

were estimated based on operations at plant capacity. For EAF plants, EPA used the 2007 

Federal Reserve industrial capacity utilization percentage of 86.6% for primary metal -- iron and 

steel production to adjust estimated actual emissions to PTE. 

 The spreadsheet contained emission CO2e estimates, including CO2, CH4, and N2O 

emissions. Process CH4 emissions were backed out of the CO2e totals using the process CH4

emissions reported in the U.S. GHG Inventory, and apportioning these emissions to the different 

plants based on their capacity in those processes. N2O emissions are primarily related to fuel 

combustion and were not backed out for separate treatment. 

New Units 

No new iron and steel facilities are expected to be built. The growth rate in primary 

metals from the U.S Census Bureau’s Economic data is only about 0.4%. 
22 

Threshold Summary 

Table 5-10 

CO2e Threshold Summary -- Iron and Steel Production 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 116 0 84.8 

55,000 114 0 84.7 

60,000 114 0 84.7 

65,000 114 0 84.7 

70,000 114 0 84.7 

75,000 114 0 84.7 

80,000 114 0 84.7 

85,000 114 0 84.7 

90,000 114 0 84.7 

95,000 114 0 84.7 

100,000 113 0 84.7 

5.9 Lead Production 

According to the 2006 USGS, lead production in the United States includes both primary, 

direct smelting (one facility), and secondary lead production (16 facilities). Process emissions of 

CO2 are a byproduct of the coke consumed during the smelting or reforming processes. EPA 

calculated total process emissions based on lead production as reported in the USGS. 

In the Supporting Data for Threshold Analysis Subpart E-W (EPA-HQ-OAR-2008-0508-

0046.7), combustion emissions are combined with process emissions to determine total actual 

emissions. 

Potential to Emit 

In order to determine PTE emissions, EPA considered the Federal Reserve's 2006 

monthly industrial capacity utilization estimates for primary metals industry classification which 

shows utilization at 85.9% for 2006, and adjusted to achieve 100% utilization. 
23 

New Units 

EPA assumed no new facilities would be added for the industry, given an expected 

growth rate of 0.4% per year for primary metal manufacturing industry. 

Threshold Summary 

Table 5-11 

CO2e Threshold Summary -- Lead Production 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 12 0 0.8 

55,000 11 0 0.7 

60,000 9 0 0.6 

65,000 8 0 0.6 

70,000 5 0 0.4 

75,000 5 0 0.4 

80,000 5 0 0.4 

85,000 2 0 0.2 

90,000 2 0 0.2 

95,000 2 0 0.2 

100,000 1 0 0.1 

5.10 Lime 

 The Supporting Data for Threshold Analysis Subpart E-W (EPA-HQ-OAR-2008-0508-

0046.7) was used to estimate GHG PTE for lime plants. 

Potential to Emit 

To estimate PTE, EPA divided annual actual CO2 emissions from the calcining process 

and fuel combustion emissions of CO2, CH4, and N2O by regional capacity factors available in 

the spreadsheet for each plant. The capacity factors ranged from 43 – 136%. 

 

New Units 

 

EPA assumed no new facilities would be added for the industry. 
24 

Threshold Summary 

Table 5-12 

CO2 Threshold Summary -- Lime Production 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 66 0 26.5 

55,000 65 0 26.5 

60,000 65 0 26.5 

65,000 63 0 26.4 

70,000 62 0 26.4 

75,000 62 0 26.4 

80,000 61 0 26.3 

85,000 61 0 26.3 

90,000 61 0 26.3 

95,000 61 0 26.3 

100,000 60 0 26.2 

5.11 Nitric Acid Production 

EPA used the 2006 nameplate capacity (metric tons of HNO3 100% acid basis) for 45 

nitric acid plants and 2006 acid production from the GHGRP TSD supporting spreadsheet (EPAHQ-OAR-2008-0508-0046.7) to determine N2O emissions. 

Potential to Emit 

The GHG PTE was calculated by multiplying actual N2O emissions as CO2e by the ratio 

of nameplate capacity to 2006 production. The permit threshold analysis, based on the GHGRP 

TSD, does not include GHG emissions from co-located stationary combustion units. Also the 

permit threshold analysis does not account for overlap between facilities in the Nitric Acid and 

Ammonia categories, which have both ammonia and nitric acid production processes. 

New Units 

EPA assumed no new units would be constructed for this sector. 
25 

Threshold Summary 

Table 5-13 

CO2e Threshold Summary -- Nitric Acid Production 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 43 0 17.7 

55,000 43 0 17.7 

60,000 43 0 17.7 

65,000 42 0 17.7 

70,000 42 0 17.7 

75,000 42 0 17.7 

80,000 42 0 17.7 

85,000 42 0 17.7 

90,000 42 0 17.7 

95,000 42 0 17.7 

100,000 42 0 17.7 

5.12 Petrochemical Production 

The Intergovernmental Panel on Climate Change (IPCC) considers production of GHGs 

from the petrochemical production sector’s manufacture and production of acrylonitrile, carbon 

black, ethylene, ethylene dichloride, ethylene oxide, and methanol to be significant compared to 

other petrochemical processes. Thus, EPA determined that this portion of the sector is most 

relevant for permit threshold analysis. 

Emissions from the manufacturing processes vary significantly, and process emissions 

take many forms. Process emissions include direct oxidation of CO2, off-gassing of CH4 and 

CO2, and the direct release of CO2 and CH4 from equipment leaks. Process emissions are the 

primary consideration for acrylonitrile, ethylene, and ethylene oxide processes. In addition, 

some processes require combustion of supplemental fuel. Both process and combustion 

emissions are significant for carbon black and methanol processes. 

Potential to Emit 

EPA's analysis assumed petrochemical production at the capacity level. Therefore, no 

adjustment to the emissions estimates is needed to account for PTE. 
26 

New Units 

EPA assumed that no new plants would be constructed, given an industry growth factor 

of -0.1% for chemical manufacturing. 

Threshold Summary 

Table 5-14 

CO2e Threshold Summary -- Petrochemical Production 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 94 0 54.7 

55,000 94 0 54.7 

60,000 93 0 54.7 

65,000 93 0 54.7 

70,000 93 0 54.7 

75,000 93 0 54.7 

80,000 93 0 54.7 

85,000 92 0 54.6 

90,000 91 0 54.5 

95,000 91 0 54.5 

100,000 91 0 54.5 

5.13 Petroleum Refineries 

In developing the permit threshold analysis for petroleum refineries, EPA quantified CH4

process emissions from wastewater, fugitive, flares, and storage tanks. Process CO2 emissions 

derived from flares, hydrogen plant emissions, and sulfur plant emissions. In addition, on-site 

combustion emissions were calculated considering fuel consumed by type. 

Potential to Emit 

EPA assumed that petroleum refineries were operating at capacity level. Therefore, no 

adjustment to the emissions estimates was needed to account for PTE. 
27 

New Units 

According to the ICR prepared for the New Source Performance Standard (NSPS), EPA 

expects that no new refineries will be built during the next several years.

Threshold Summary 

Table 5-15 

CO2e Threshold Summary -- Petroleum Refineries 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 137 0 204.5 

55,000 136 0 204.5 

60,000 135 0 204.4 

65,000 135 0 204.4 

70,000 134 0 204.3 

75,000 132 0 204.2 

80,000 131 0 204.1 

85,000 131 0 204.1 

90,000 129 0 204.0 

95,000 129 0 204.0 

100,000 129 0 204.0 

5.14 Pulp and Paper Manufacturing 

Permit threshold analysis for this sector is focused on the energy intensive, fugitive 

emitting, pulp, paper, and paperboard manufacturing subsectors. Process emissions include CO2, 

which is emitted in the recovery cycle at kraft and soda facilities associated with the chemical 

pulp process. The CO2 emitted from kraft mill lime kilns originates from two sources: (1) fossil 

fuels burned in the kiln and (2) conversion of calcium carbonate (or "lime mud") generated in the 

recovery process to calcium oxide. 

The bulk of the emissions considered derive from combustion. Many boilers use biomass 

fuel, and the burning of spent pulping liquors to produce steam for facility processes is 

considered biomass combustion for the GHGRP. The emissions numbers considered for the 

permit threshold analysis are non-biogenic (net of any biogenic emissions). Considering only 
28 

non-biogenic emissions, 96.5% of the facilities and 99.7% of the emissions are captured by all of 

the thresholds proposed for consideration of the permit threshold rule. 

Potential to Emit 

Because 99.7% of emissions were captured at even the highest threshold, no additional 

PTE estimate was calculated in this analysis. 

New Units 

Based on an industry growth factor of -2.5% for paper manufacturing, and previous EPA 

analysis for the pulp and paper NSPS ICR, EPA assumed that no new plants would be 

constructed. 

Threshold Summary 

Table 5-16 

CO2e Threshold Summary -- Pulp and Paper Manufacturing 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 422 0 57.7 

55,000 422 0 57.7 

60,000 422 0 57.7 

65,000 420 0 57.7 

70,000 420 0 57.7 

75,000 415 0 57.6 

80,000 415 0 57.6 

85,000 415 0 57.6 

90,000 412 0 57.6 

95,000 412 0 57.6 

100,000 410 0 57.5 
29 

5.15 Unspecified Industrial Stationary Combustion Sources 

In order to determine establishment counts and emissions totals for the unspecified 

industrial stationary combustion sources, EPA used 2002 Economic Census data showing 

manufacturing employment by NAICS code and EIA MECS data. Calculating GHG emissions 

required determining energy consumption per employee by industry and applying emission 

factors specific to the consumption profile derived from the MECS data. 

The 2002 Economic Census data provide a count of establishments by employment 

category, where employment category is defined by number of employees (e.g., 1 – 4, 

5 – 9, . . . , 500 – 999, . . . , more than 2,500). The MECS data show energy consumption by 

industry. Both the employment data and the energy consumption data are organized according to 

the NAICS codes. 

Potential to Emit 

As part of this analysis, EPA calculated industry-specific GHG emission factors. The 

factors were calculated by considering actual fuel consumption in 2002, as determined by EIA. 

Actual fuel consumed was multiplied by fuel-specific GHG emission factors to determine GHG 

emissions by fuel type by industry. To simplify the analysis, EPA included only CO2 emissions 

and ignored CH4 and N2O in the CO2e calculations. CO2 makes up between 99.3 and 99.7% of 

estimated CO2e emissions. Emissions for each fuel type were combined to determine total 

emissions for a sector. Total emissions per sector were divided by total energy consumption per 

sector to determine a factor to calculate GHG emissions per mmBtu of energy consumption 

specific to the industrial sector. 

The GHG emission factors were then multiplied by the energy consumption per 

employee in order to determine emissions per employee. EPA determined total GHG emissions 

per establishment by multiplying the result by the average number of employees per 

establishment. EPA assumed a capacity factor of 50% to adjust actual emissions to PTE. 

As noted above, a separate threshold analysis was conducted for the 23 industrial source 

categories that were determined to have significant GHG emissions in the GHGRP analysis. In 

order to quantify the unspecified industrial stationary combustion source emissions, EPA 

subtracted the combustion emissions and establishment counts from 19 of these categories from 

the total industrial MECS analysis. EPA could not readily isolate combustion emissions from 

the remaining four industries: HCFC-22 production, hydrogen production, magnesium 

production, and nitric acid production. For these industries, EPA subtracted their establishment 

counts from the unspecified industrial source threshold counts based on process emission 

threshold evaluations. EPA assumed that any facility exceeding a threshold for process-based 

emissions would exceed the threshold regardless of its combustion CO2 emissions. 
30 

Table 5-17 

CO2e Threshold Summary -- Unspecified Industrial Stationary Combustion 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 3,272 12 206.9 

55,000 1,470 4 163.6 

60,000 1,399 4 161.8 

65,000 1,399 4 161.8 

70,000 1,399 4 161.8 

75,000 1,392 4 161.5 

80,000 1,392 4 161.5 

85,000 1,166 3 153.8 

90,000 1,166 3 153.8 

95,000 1,024 2 147.9 

100,000 958 2 145.1 

6. Energy Sector 

This sector consists of Oil and Gas Systems (oil and gas extraction, transport, and 

processing) and Underground Coal Mines. 

6.1 Oil and Gas Systems 

 In consideration of the permit thresholds, EPA considered the Fugitive Emissions 

Reporting from the Petroleum and Natural Gas Industry: Background Technical Support 

Document (EPA-HQ-OAR-2008-0508-0023). This document details combustion emissions and 

fugitive emissions from offshore petroleum and natural gas facilities, onshore natural gas 

processors, onshore natural gas transmission, underground natural gas storage, and liquid natural 

gas storage. EPA determined that oil and gas exploration, development, transmission, and 

distribution are not listed PSD source categories. Thus, EPA did not consider fugitive emissions 

from these activities for PSD applicability as it relates to major source thresholds. Rather, EPA's 

analysis focused on combustion emissions from these sources. 
31 

Potential to Emit 

Although the emission information from the GHGRP was limited, it provided process 

emissions and combustion emission totals and facility counts for four CO2e actual emissions 

thresholds: 1,000, 10,000, 25,000, and 100,000 (See EPA-HQ-OAR-2008-0508-0023, Table 4). 

For this analysis, EPA assumed process emissions were fugitive emissions and used only the 

average facility combustion emissions by the four thresholds for the PTE analysis. EPA used a 

capacity utilization figure of 50% applied to the average stationary combustion emissions to 

determine PTE emission estimates and counts. 

New Units 

EPA determined new units based on a growth factor of 1.0% for the sector. 

Threshold Summary 

Table 6-1 

CO2e Threshold Summary -- Oil and Gas Systems 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 1,045 10 56.9 

55,000 1,045 10 56.9 

60,000 1,045 10 56.9 

65,000 1,045 10 56.9 

70,000 1,045 10 56.9 

75,000 387 4 32.8 

80,000 387 4 32.8 

85,000 387 4 32.8 

90,000 387 4 32.8 

95,000 387 4 32.8 

100,000 387 4 32.8 

6.2 Underground Coal Mining 

 GHG emissions from underground coal mining include CH4 fugitive emissions released 

from the coal seam and surrounding rock during mining and post-mining activities (coal bed 

CH4), and fuel combustion emissions of CO2, CH4, and N2O. Fugitive CH4, emissions are 

captured and vented by ventilation systems and degassing systems. Captured and vented CH4
32 

emissions from active mines were considered in the PTE analysis. Because underground coal 

mining is not one of the 28 PSD source categories for which fugitive emissions were required to 

be included in the emissions determination, fugitive emissions from post mining operations, 

surface mines, and inactive mines were not included in the permit thresholds analysis. 

 The Technical Support Document for Underground Coal Mines: Proposed Rule for 

Mandatory Reporting of Greenhouse Gases (EPA-HQ-OAR-2008-0508-0032) identified 612 

active underground coal mining facilities; however, analysis of CH4 emissions was limited to 

128 "gassy" mines where CH4 monitoring was already in place (due to existing CH4 emissions 

above Mine Safety and Health Administration (MSHA) threshold levels). The U.S. GHG 

Inventory (EPA, 2008) indicates that 233 underground coal mines (including 133 gassy mines) 

ventilated CH4 in 2007. Fuel combustion emission estimates for the GHGRP TSD from all 

underground coal mines, based on U.S. Census Bureau Energy Use data, were found to 

constitute 1 – 3% of total CO2e emissions, with coal bed CH4 accounting for the bulk of GHG 

emissions. 

 In addition to the emissions data on the 128 gassy mines contained in the GHGRP TSD, 

EPA considered combustion emissions from 289 bituminous underground coal mines, using 

2002 U.S. Census data. 

Potential to Emit

CH4

CH4 emission estimates that were developed for the GHGRP TSD were used for both 

actual emissions and PTE emissions permit threshold analysis. EPA assumed that venting and 

degassing were continuous throughout the year; therefore, actual emission estimates equal PTE 

emission estimates. The estimates considered 128 gassy mines, which were assumed to be the 

largest emitters of vented CH4. The smallest mine of this group had annual CH4 emissions of 26 

tons. Thus, EPA assumed that annual CH4 emissions from the 105 vented mines that were not 

included in the TSD analysis were less than 26 tons. 

CO2 

CO2 emissions were estimated in the same manner as for other Unspecified Industrial 

Stationary Combustion categories, based on the ICF analysis (ICF, 2007) using the MECS 

approach. Emissions were estimated based on U.S Census Bureau data on fuel consumption per 

employee and the distribution of establishments by the number of employees. PTE was 

estimated by using a capacity utilization factor of 86.3% as published by the Federal Reserve. 

New Units

The number of underground bituminous coal mines in the United States is on the decline. 

EIA data indicate that the number of underground coal mines decreased by 8% between 2006 

and 2007, with only Colorado showing an increase during that period (EIA, 2008). 
33 

Consequently, EPA assumed that no new underground mines would be built. 

http://www.eia.doe.gov/cneaf/coal/page/acr/table1.html. 

Threshold Summary 

Table 6-2 

CO2e Threshold Summary -- Underground Coal Mining 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 78 0 32.8 

55,000 77 0 32.8 

60,000 74 0 32.6 

65,000 70 0 32.4 

70,000 67 0 32.2 

75,000 67 0 32.2 

80,000 64 0 32.0 

85,000 63 0 31.9 

90,000 60 0 31.7 

95,000 57 0 31.4 

100,000 55 0 31.2 

7. Waste Sector 

 For the waste sector, EPA evaluated Landfills and Municipal Waste Combustors. 

7.1 Landfills 

 The landfill PTE analysis includes both municipal solid waste (MSW) landfills and onsite 

industrial landfills associated with pulp and paper and food processing. The analysis used a 

modification of the landfill emission modeling approach used for the GHGRP threshold analysis. 

As with the GHGRP analysis, the permit threshold PTE analysis did not include onsite industrial 

landfills for ethanol processing facilities or industrial land application systems. 

GHG Emissions 

 Decomposition of waste in landfills generates CH4 and CO2. The amount of CH4

generated from a given landfill is a function of several factors: the total amount of waste 
34 

disposed in the landfill; the characteristics of the waste; and the climatic conditions. The amount 

of CH4 emitted is the amount of CH4 generated minus the amount of CH4 oxidized by aerobic 

microorganisms in the landfill cover material. Also subtracted from the total is the amount of 

CH4 that is destroyed by combustion of the vented gas. The CO2 produced by decaying waste is 

not considered an anthropogenic emission, and is not counted in GHG emission totals. Likewise, 

CO2 resulting from the combustion of landfill CH4 is not accounted for as an anthropogenic 

emission under international accounting guidance. 

 According to the 2008 U.S. Inventory, MSW landfills emitted 111.2 million metric tons 

CH4 (CO2e basis) in 2006. The majority of CH4 emissions from on-site industrial landfills occur 

at pulp and paper facilities and food processing facilities. In 2006, these landfills emitted 14.6 

million metric tons CO2e 

Potential to Emit 

 The methodology used for the GHGRP threshold analysis was also used to estimate CH4

generation rates and emissions in 2006 for the PTE analysis. A landfill-specific model 

developed by EPA to support its GHGRP was used to estimate CH4 generation and potential 

generation from municipal landfills. The generation estimate was adjusted with assumptions on 

oxidation in landfill cover, and destruction by combustion for energy recovery or flaring. The 

industrial landfill generation and emission estimates are based on the U.S. GHG Inventory. 

Industrial landfills were assumed not to have energy recovery or flaring, so there was no 

difference between generation and emissions. 

New Units 

EPA did not estimate the number of new facilities added each year with CH4 emissions 

above the different thresholds due to the time delay between landfill construction and emission 

generation. 
35 

Threshold Summary 

Table 7-1 

CO2e Threshold Summary -- Landfills 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

CO2e Emissions 

Covered 

(Tg per year)

50,000 1,684 92.3 

55,000 1,603 90.1 

60,000 1,523 88.0 

65,000 1,447 86.0 

70,000 1,372 84.0 

75,000 1,299 82.1 

80,000 1,229 80.2 

85,000 1,169 78.5 

90,000 1,105 76.5 

95,000 1,029 74.5 

100,000 967 72.7 

7.2 Municipal Solid Waste Combustors 

The threshold analysis for the GHGRP included municipal solid waste combustors 

(MWC) in the general stationary fuel combustion category. The analysis used the eGRID 

database, which is discussed in the PTE methodology description for electric generating units. 

Data and Methodology 

EPA used the latest version of the eGRID database (2006) to estimate the PTE of MWC 

facilities and counts of facilities above the different emission thresholds. eGRID includes year 

2004 characteristics, operating information, and annual CO2 emissions for U.S. facilities that 

have a generation capacity greater than one MW and sell electric power to the grid. In using 

eGRID, EPA assumed that all MWC facilities sell power to the grid. 
36 

Potential to Emit 

 EPA identified 75 MWC facilities based on the generator primary fuel in the generator 

table (primary fuel equals MSW) in the eGRID database. The eGRID database contains CO2

annual emissions estimates for the facilities. For CO2 emissions, eGRID uses a standard 

assumption that 70% of the heat value of the waste stream comes from renewable materials and 

30% comes from nonrenewable materials. The renewable fraction has a CO2 emission rate of 

zero. Thus, the PTE threshold analysis is based on the nonrenewable or fossil fraction 

assumption. EPA estimated PTE by dividing the annual emissions from eGRID by the eGRID 

plant capacity factor. 

New Units 

 To determine the number of new per year at different thresholds, EPA counted the 

number of generators online each year and totaled the nameplate capacity for each online year. 

EPA compared this information to the total facility nameplate capacity and calculated the PTE 

for the increased capacity by multiplying the facility PTE by the fraction of nameplate capacity 

associated with the new generators. EPA counted the facilities that exceeded the PTE thresholds 

during each period and computed a 15-year average to determine the number of new or modified 

facilities per year. 

Threshold Summary 

Table 7-2 

CO2 Threshold Summary -- Municipal Solid Waste Combustors 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 67 1 6.1 

55,000 65 1 6.0 

60,000 55 1 5.7 

65,000 53 1 5.6 

70,000 51 1 5.5 

75,000 48 1 5.4 

80,000 47 1 5.3 

85,000 45 1 5.2 

90,000 44 1 5.2 

95,000 42 1 5.1 

100,000 40 1 5.0 
37 

8. Commercial Stationary Fuel Combustion 

Commercial buildings include all buildings in which at least half of the floor space is 

used for a purpose that is not residential, industrial, or agricultural. The source category includes 

building types that might not traditionally be considered "commercial," such as schools, 

correctional institutions, and buildings used for religious worship. 

Data Source 

EPA used EIA's Commercial Building Energy Consumption Survey (CBECS) to estimate 

commercial sector stationary fuel combustion GHG emissions and PTE. CBECS is a national 

sample survey that collects information on the stock of U.S. commercial buildings, their energyrelated building characteristics, and their energy consumption and expenditures. The CBECS 

survey is conducted every four years, with the most recent survey completed in 2003. 

The CBECS survey sample was designed so that survey responses could be used to 

estimate characteristics of the entire nationwide commercial building stock. The 2003 survey 

selected 6,955 potential case buildings for sampling. The sampling procedures resulted in 5,215 

completed building interviews for a response rate of 82%. To make national estimates from the 

sample data, EIA calculated base sampling weights for each building (the reciprocal of the 

probability of that building being selected into the sample). In other words, the base sampling 

weight is the number of national buildings represented by the sampled building. The base weight 

was further adjusted to account for nonresponsive bias. 

 EIA publishes summary tables from the survey, and posts "microdata" files on the EIA 

website. The CBECS microdata consist of the 5,215 sampled building records, which each 

correspond to a single sampled building. For each building, these files contain information such 

as the building size, climatic region, U.S. Census region, year constructed, types of energy used, 

and energy consumption and expenditures. These individual building microdata records are also 

the basis for the summary tables published by EIA. 

Emissions Methodology 

EPA used the CBECS microdata to estimate commercial building emissions and 

populations above emission thresholds. Each of the 5,215 microdata records corresponds to a 

single sampled building. EIA has made available 20 different data files of the microdata records 

which contain a wide range of information on characteristics and energy use for each building. 

 EPA's analysis relied on guidance provided by EIA on how to use the data. As noted 

above, the CBECS sample was designed so that survey responses could be used to estimate 

characteristics of the entire commercial building stock nationwide. The table below provides 

examples from EIA on how to calculate national commercial building characteristics from the 

sample building data. 
38 

Table 8-1 

EIA Website Examples 

To Find the National 

Estimate for: Do This... 

And You 

Should Get... 

Total number of buildings Sum ADJWT8 (weight factor) 4,858,749.82 

(or 4,859 thousand) 

Total number of office 

buildings 

Sum ADJWT8 for cases where PBA8 (building code) = "02" 823,805.47 

(or 824 thousand) 

Total floor space Create a new variable (weighted square footage) by 

multiplying ADJWT8 by SQFT8 (floor space) for each case, 

then sum this new variable 

71,657,900,522 

(or 71,658 million ft2

) 

Total floor space in 

buildings with air 

conditioning 

Sum the new weighted square footage variable (see above) 

for cases where COOL8 (air conditioning) = "1" 

63,559,999,624 

(or 63,560 million ft2

) 

Total electricity 

consumption in KWh 

Create a new variable (weighted electricity consumption) by 

multiplying ADJWT8 by ELCNS8 (electricity consumption) 

for each case, then sum this new variable 

1,043,175,710,751 

(or 1,043 billion kWh) 

Source: http://www.eia.doe.gov/emeu/cbecs/cbecs2003/public_use_2003/cbecs_pudata2003.html. 

 For each surveyed building EIA calculated base sampling weights, which are the 

reciprocal of the probability of that building being selected into the sample. Thus, a building 

with a base weight of 1,000 represents itself and 999 similar but unsampled buildings in the total 

building stock. The base weight is further adjusted to account for non-response bias. The 

variable "ADJWT8" in the data file is the final weight. The ADJWT8 weight factor is used as 

described in Table 8-1 to extrapolate the survey sample to a national scale for any value. In 

order to obtain a national value each sample building's value must be multiplied by the building's 

weight (ADJWT8). All of the weighted values are then summed. 

2003 CO2 Emissions 

 EPA calculated the CO2 emissions for each of the 5,215 buildings based on the annual 

natural gas and oil consumption reported for the building. For national emission estimates and 

counts of buildings with annual CO2 emissions over any threshold, EPA multiplied the base 

weights by the sample emission totals to determine the national estimate of buildings with 

emissions over the threshold. 
39 

Potential to Emit 

 EPA estimates that commercial buildings operate at 15% of capacity. EPA considered 

several sources in making the PTE factor determination: 

● A report prepared by Energy and Environmental Analysis, Inc., for Oak Ridge National 

Laboratory describing the industrial and commercial boiler population in the United 

States (EEA, 2005). The report estimated an average commercial boiler capacity factor 

of 16%. 

● Reports on cooking equipment energy use by the Food Service Technology Center in 

California suggesting that the cooking equipment in food service establishments operate 

at about 10% of a theoretical maximum capacity based on 8,760 hours per year (Pechan 

et.al, 2008). 

● A study of Los Angeles dry cleaners performed by the Pollution Prevention Education 

and Research Center (PPERC) in 2004 which demonstrates that dry cleaners operate 

boilers at about 10 – 15% of maximum capacity over a normal year (Pechan et al., 2008). 

New Buildings 

 The CBECS data identifies the year the sampled buildings were constructed. EPA used 

the construction year information to identify the number of new buildings built each year in the 

1990 to 2003 period. Counts of the average number of these buildings built per year were then 

made at the different emissions and PTE thresholds. 

Threshold Summary 

 The count of buildings and emissions at the threshold levels for the entire sector are 

shown in Table 8-2. Threshold results by commercial building categories (e.g., offices, public 

assembly, schools) are provided in Appendix B. 
40 

Table 8-2 

CO2e Threshold Summary -- Commercial Sector Stationary Fuel Combustion 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 600 3 6.0 

55,000 534 3 5.5 

60,000 346 3 4.1 

65,000 268 3 3.4 

70,000 262 3 3.4 

75,000 225 3 3.0 

80,000 201 3 2.7 

85,000 106 2 1.7 

90,000 74 2 1.3 

95,000 63 2 1.2 

100,000 51 2 1.0 

9. Residential Stationary Combustion 

EPA’s original threshold analysis for the Tailoring Rule evaluated both stationary 

combustion emissions from both single family and multi-family buildings. Single family 

buildings are not affected at the 50,000 to 100,000 tons CO2e thresholds and are not included 

here. 

9.1 Multi-Family Residential Buildings 

Data Sources 

EPA used residential fuel consumption data from EIA's Residential Energy Consumption 

Survey (RECS) and multi-family building and unit data from U.S. Census Bureau surveys to 

estimate CO2 emissions and PTE for fuel combustion at single and multi-family residential 

properties. The RECS is a national area-probability sample survey that collects energy-related 

data for occupied primary housing units. The most recent 2005 survey collected data from 4,382 

households in housing units statistically selected to represent the 111.1 million housing units in 

the United States. RECS data are tabulated for the four Census regions, the nine Census 

divisions, and for the four most populous States -- California, Florida, New York, and Texas. 

 The RECS sample was designed so that survey responses could be used to estimate 

characteristics of the national stock of occupied housing units. In order to arrive at national 
41 

estimates from the RECS sample, EPA calculated base sampling weights for each housing unit 

as the reciprocal of the probability of that building being selected into the sample. Therefore, a 

housing unit with a base weight of 10,000 represents itself and 9,999 similar, but not sampled, 

housing units in the total stock of occupied residential housing units. The base weight is further 

adjusted to account for non-response bias. Ratio adjustments were also used to ensure that the 

RECS weights add up to the U.S Census Bureau’s Current Population Survey estimates of the 

number of households. 

 The RECS data are provided at the housing unit level, and not at the building level. EPA 

used additional U.S Census Bureau data on multi-family building population characteristics to 

estimate total property emissions and PTE for multi-unit properties. Census data were drawn 

from the Property Owner and Manager Survey (POMS, 1996) and the American Housing Survey 

(AHS, 2005). 

Emission Rates 

As indicated above, the RECS data are on an individual unit basis, not a building or 

property basis. Thus, EPA was required to use a different approach for multi-family units, 

assuming common ownership of the property fuel combustion equipment. In order to estimate 

property emissions and the number of properties above different emission and PTE thresholds, 

EPA combined the RECS data with data from the POMS and AHS. 

 From the RECS data, EPA first calculated average residential unit CO2 emissions for the 

two most common fuels (natural gas and oil) by multi-family category. These are shown in the 

table below. 

Table 9-1 

Multi-Family Residential Unit -- Average Annual CO2 Emissions 

(RECS, 2005) 

Multi-Family Category 

(number of units) 

Natural Gas Space Heating 

(tons CO2/residential unit-year) 

Fuel Oil Space Heating 

(tons CO2/residential unit-year) 

2 to 4 units 4.8 8.3 

5 or more units 3.0 8.9 

 EPA also obtained annual CO2 emission rates from an EPA analysis that was based on 

Lawrence Berkeley National Lab (LBNL) modeling studies. Those rates were estimated for old 

and new building units (see Table 9-2). The pre-1980 building estimate compares with the 

overall average from the RECS data. The post-1980 building estimates are much lower, 

particularly for units burning fuel oil. 
42 

Table 9-2 

Multi-Family Residential Unit -- Average Annual CO2 Emissions 

(2008 EPA Analysis based on LBNL, 1997) 

Multi-Family Category 

(building age) 

Gas Serviced Units 

(tons CO2/residential unit-year) 

Fuel Oil Serviced Units 

(tons CO2/residential unit-year) 

Pre-1980 building 4.75 7.17 

Post-1980 building 2.65 3.87 

Existing Property Characteristics 

Information on the distribution of multi-family properties by number of units per property 

was taken from the 1995 – 1996 POMS. The data are aggregated by different housing unit 

ranges. The table below shows the property size distribution from unpublished POMS data 

(NMHC Quick Facts -- Apartment Stocks (http://www.nmhc.org)). The POMS data were for 

privately owned housing only and excluded public housing projects (about 13,500 buildings and 

1,326,000 units). For its estimates, EPA adjusted the building numbers to current (2005) levels 

based on the RECS unit data (unit ratio of RECS to POMS) and assumed the same unit 

distribution in the adjustment. 

Table 9-3 

Multi-Family Residential Property Size Distribution 

(National Multi-Housing Council tabulation of unpublished POMS data, 1995-1996) 

Number of Rental 

Units on Property 

Number of Properties 

(1995-1996) 

Number of Units 

(1995-1996) 

Average Number 

of Units per 

Property 

2 1,558,700 3,093,200 2 

3 336,030 1,025,900 3 

4 341,350 1,436,800 4 

5 – 9 281,500 1,897,700 7 

10 – 14 70,390 862,280 12 

15 – 19 36,780 602,260 16 

20 – 29 38,000 916,750 24 

30 – 39 18,166 604,240 33 

40 – 49 14,431 702,790 49 

50 – 99 26,694 2,009,400 75 

(cont.)
43 

Table 9-3 

Multi-Family Residential Property Size Distribution (National Multi-Housing 

Council tabulation of unpublished POMS data, 1995-1996) (cont.) 

Number of Rental 

Units on Property

Number of Properties 

(1995 – 1996)

Number of Units 

(1995 – 1996)

Average Number 

of Units per 

Property

100 – 199 19,804 2,952,300 149 

200 – 299 7,775 1,948,400 251 

300 – 399 2,966 1,058,800 357 

400 – 499 1,307 605,130 463 

500 – 749 723 431,360 597 

Over 750 307 437,670 1,426 

Total 2,754,923 20,584,980 

 The adjusted POMS size distribution and average number of units in each category were 

combined with information from RECS on the percentage of units that use gas or oil for space 

heating. The gas and oil emission factors from the previous tables were applied to the average 

number of units in each property size category by fuel to estimate property annual CO2

emissions. 

 For its final estimates, EPA used the LBNL based emission factors for post-1980 

buildings, over the RECS based factor. EPA found that these lower emission factors resulted in 

total emissions more in line with the total based on all RECS units and residential sector 

estimates in the U.S. GHG Inventory. The RECS-based factors combined with the POMS 

property distribution data resulted in a larger overestimate in overall category annual emissions. 

The lack of information on the building population over 50 units and on the correlation between 

unit emissions and building/property size is a significant cause of uncertainty in the estimates at 

thresholds above 1,000 tons. 

Potential to Emit 

 PTE was estimated using the same 10% capacity factor as used for the single family 

residential units. This factor was estimated by comparing the average annual CO2 emissions per 

heated floor space area per hour by climate zone to required heat input capacity. The required 

heat input capacity was based on rule of thumb heating system requirements for the different 

climate zones. The table below shows the average Btu/ft2

-hour from the RECS data and Heating 

Requirement (Btu/ft2

) by climate zone. A heating system efficiency of 80% was used to estimate 

the required space heating capacity. 
44 

Table 9-4 

Single-Family Detached and Attached 

Households with Fossil Fuel-Fired Space Heating 

(RECS, 2005) 

Households 

(millions) 

Climate 

Zone(s) 

Heating Degree 

Day Range 

Average Annual Fuel 

Consumption 

(Btu/ft2-hour) 

Space Heating 

Requirement* 

(Btu/ft2) 

6.8 5 > 7,000 4.8 50 – 60 

16.7 4 5,500 – 7,000 5.4 45 – 50 

17.0 3 4,000 – 5,499 4.6 40 – 45 

18.9 1 and 2 < 4,000 3.8 Zone 2: 35 – 40 

Zone 1: 30 – 35 

*Heating requirement ranges are from www.acdirect.com/systemsize.php. 

New Properties 

The AHS data provided information on new construction used to estimate the number of 

new buildings and new units with natural gas space heating that were constructed in the 1999 – 

2005 period. To simplify the analysis, EPA ignored the limited use of fuel oil for space heating 

in new units. 

 The AHS data provided separately the number of new buildings with gas space heating 

per year, and a size distribution for all new buildings per year. The AHS size distribution 

stopped at 50 and larger, and was slightly different in other categories from the POMS data. 

EPA adjusted the distribution based on the POMS distribution and used the same emission and 

capacity factor approach as was used for existing units. 
45 

Table 9-5 

American Housing Survey New Building Data 

Building Size: 

Number of Units 

per Building 

Number of New 

Buildings per Year 

(1999 – 2005) 

(thousands) 

Fraction of All 

New Buildings 

per Year 

(1999 – 2005) 

New Gas Buildings 

per Year 

(1999 – 2005) 

(thousands) 

Number of New 

Gas Buildings 

per Year 

2 6.3 0.22 

16.0 

3,468 

3 – 4 5.4 0.19 2,995 

5 – 9 6.1 0.21 3,389 

10 – 19 6.0 0.21 3,310 

20 – 29 3.1 0.11 1,734 

30 – 49 1.0 0.03 552 

50 or more 1.0 0.03 552 

Total 29.0 1.00 16.0 16,000 

Threshold Summary 

Table 9-6 

CO2e Threshold Summary – Multi-Family Residential 

GHG Threshold 

(tons per year) 

Number of 

Existing Sources 

Number of New 

Facilities Added 

per Year 

CO2e Emissions 

Covered 

(Tg per year)

50,000 20 0 0.1 

55,000 20 0 0.1 

60,000 0 0 0 

65,000 0 0 0 

70,000 0 0 0 

75,000 0 0 0 

80,000 0 0 0 

85,000 0 0 0 

90,000 0 0 0 

95,000 0 0 0 

100,000 0 0 0 
46 

References 

E.H. Pechan & Associates, Inc., Perrin Quarles Associates, Inc., and Alpine Geophysics, LLC, 

Greenhouse Gas (GHG) Emissions and New Source Review, Work Assignment No. 1-06, EPA 

Contract No. EP-D-07-097, April 10, 2008 (EPA-HQ-OAR-2008-0318-0080). 

Environmental Energy and Analysis, Inc. (EEA), Characterization of the U.S. Industrial 

Commercial Boiler Population, submitted to Oak Ridge National Laboratory, May 2005 

(EPA-HQ-OAR-2008-0318-0005). 

http://www1.eere.energy.gov/industry/distributedenergy/pdfs/characterization_industrial_comme

rical_boiler_population.pdf

Energy and Environmental Analysis, Inc. (EEA), World of Distributed Generation in Delaware, 

February 2004. 

http://www.eeainc.com/rrdb/DGRegProject/Documents/DEDGWorld.pdf

Federal Register, 74 FR 16447, Mandatory Greenhouse Gas Reporting Regulations; Proposed 

Rule, Washington, D.C., April 10, 2009. 

Federal Reserve, Statistical Release G17. Industrial Production and Capacity Utilization. 

http://www.federalreserve.gov/releases/g17/About.htm

ICF, International, Memorandum from Chris Steuer, Marian Van Pelt and Robert Lanza 

regarding Methodology Description for Industrial Sector GHG Threshold Analysis, November 2, 

2007 (EPA-HQ-OAR-2008-0318-0079). 

Lawrence Berkeley National Laboratory (LBNL). Energy Data Sourcebook for the U.S. 

Residential Sector. Prepared by Energy Analysis Program, Environmental Energy Technologies 

Division, LBNL, University of California, Berkeley, CA, September 1997. 

http://enduse.lbl.gov/info/Pubs95_99.html

National Multi-Housing Council (NMHC), Quick Facts Apartment Stock: Distribution of 

Apartments by Size of Property, NMHC tabulation of unpublished data from the U.S. Census 

Bureau's 1995-1996 Property Owners and Managers Survey. http://www.nmhc.org/

U.S. Census Bureau (2006), American Housing Survey for the United States: 2005. 

http://www.census.gov/hhes/www/housing.html. 

U.S. Census Bureau (2004), 2002 Economic Census, August 2004. 

http://www.census.gov/econ/census02/

U.S. Census Bureau (1998), 1995 Property Owners and Managers Survey, 1998. 

http://www.census.gov/hhes/www/housing/poms/poms.html

U.S. Energy Information Administration (EIA), Electric Power Annual, 2007, January 21, 2009. 

http://www.eia.doe.gov/cneaf/electricity/epa/epa_sum.html
47 

U.S. Energy Information Administration (EIA), Annual Energy Review 2005, DOE/EIA-0384, 

July 1, 2006. 

U.S. Energy Information Administration (EIA), 2005 Residential Energy Consumption Survey, 

February 2009. 

http://www.eia.doe.gov/emeu/recs/recspubuse05/pubuse05.html

U.S. Energy Information Administration (EIA), 2003 Commercial Building Energy Consumption 

Survey, December 2006. 

http://www.eia.doe.gov/emeu/cbecs/cbecs2003/public_use_2003/cbecs_pudata2003.html

U.S. Energy Information Administration (EIA), 2002 Manufacturing Energy Consumption 

Survey, January 2007. 

http://www.eia.doe.gov/emeu/mecs/contents.html

US. Environmental Protection Agency (EPA), Technical Support Document for Greenhouse Gas 

Emissions Thresholds Evaluation, March 29, 2010 (EPA-HQ-OAR-2009-0517-19158). 

U.S. Environmental Protection Agency (EPA), Inventory of U.S. Greenhouse Gas Emissions and 

Sinks: 1990-2007, April 2009, US EPA 430-R-09-004. 

http://www.epa.gov/climatechange/emissions/usinventoryreport.html

U.S. Environmental Protection Agency (EPA), Supporting Data for Threshold Analysis Subpart 

E-W, Greenhouse Gas Mandatory Reporting Rulemaking, March 10, 2009 (EPA-HQ-OAR2008-0508-0046.7). 

U.S. Environmental Protection Agency (EPA), Supporting Data for Threshold Analysis Subpart 

X-PP, Greenhouse Gas Mandatory Reporting Rulemaking, March 10, 2009 (EPA-HQ-OAR2008-0508-0046.8). 

U.S. Environmental Protection Agency (EPA), Emissions & Generation Resource Integrated 

Database (eGRID) 2006, May 2007. 

http://www.epa.gov/cleanenergy/energy-resources/egrid/index.html#download

U.S. Environmental Protection Agency (EPA), Draft U.S. Adipic Acid and Nitric Acid N2O 

Emissions 1990-2020: Inventories, Projections and Opportunities for Reductions, November 

2001. 

http://www.epa.gov/nitrousoxide/pdfs/adipic_nitric_n2o.pdf

U.S. Environmental Protection Agency (EPA), Climate Change Division, Fugitive Emissions 

Reporting from the Petroleum and Natural Gas Industry: Background Technical Support 

Document, undated, FR publish date: March 26, 2009 (EPA-HQ-OAR-2008-0508-0023). 

U.S. Environmental Protection Agency (EPA), Office of Air and Radiation, Technical Support 

Document for the Ammonia Production Sector: Proposed Rule for Mandatory Reporting of 

Greenhouse Gases, January 22, 2009 (EPA-HQ-OAR-2008-0508-0007). 
48 

U.S. Environmental Protection Agency (EPA), Office of Air and Radiation, Technical Support 

Document for Process Emissions from Cement: Proposed Rule for Mandatory Reporting of 

Greenhouse Gases, January 28, 2009 (EPA-HQ-OAR-2008-0508-0008). 

U.S. Environmental Protection Agency (EPA), Office of Air and Radiation, Technical Support 

Document for Process Emissions From Electronics Manufacture (Semiconductors, MEMs, 

Liquid Crystal Displays, and Photovoltaics), January 29, 2009 (EPA-HQ-OAR-2008-0508-

0009). 

U.S. Environmental Protection Agency (EPA), Office of Air and Radiation, Technical Support 

Document for the Glass Manufacturing Sector: Proposed Rule for Mandatory Reporting of 

Greenhouse Gases, January 22, 2009 (EPA-HQ-OAR-2008-0508-0014). 

U.S. Environmental Protection Agency (EPA), Office of Air and Radiation, Technical Support 

Document for the Hydrogen Production: Proposed Rule for Mandatory Reporting of Greenhouse 

Gases, August 5, 2008 (EPA-HQ-OAR-2008-0508-0016). 

U.S. Environmental Protection Agency (EPA), Office of Air and Radiation, Technical Support 

Document for the Iron and Steel Sector: Proposed Rule for Mandatory Reporting of Greenhouse 

Gases, September 9, 2008 (EPA-HQ-OAR-2008-0508-0017). 

U.S. Environmental Protection Agency (EPA), Office of Air and Radiation, Technical Support 

Document for the Lead Production Sector: Proposed Rule for Mandatory Reporting of 

Greenhouse Gases, January 22, 2009 (EPA-HQ-OAR-2008-0508-0018). 

U.S. Environmental Protection Agency (EPA), Office of Air and Radiation, Technical Support 

Document for the Lime Manufacturing Sector: Proposed Rule for Mandatory Reporting of 

Greenhouse Gases, January 22, 2009 (EPA-HQ-OAR-2008-0508-0019). 

U.S. Environmental Protection Agency (EPA), Office of Air and Radiation, Technical Support 

Document for the Petrochemical Production Sector: Proposed Rule for Mandatory Reporting of 

Greenhouse Gases, September 9, 2008 (EPA-HQ-OAR-2008-0508-0024). 

U.S. Environmental Protection Agency (EPA), Office of Air and Radiation, Technical Support 

Document for the Petroleum Refining Sector: Proposed Rule for Mandatory Reporting of 

Greenhouse Gases, September 9, 2008 (EPA-HQ-OAR-2008-0508-0025). 

U.S. Environmental Protection Agency (EPA), Office of Air and Radiation, Technical Support 

Document for the Pulp and Paper Sector: Proposed Rule for Mandatory Reporting of 

Greenhouse Gases, February 11, 2009 (EPA-HQ-OAR-2008-0508-0027). 

U.S. Environmental Protection Agency (EPA), Office of Air and Radiation, Technical Support 

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49 

Appendix A 

Sector CO2e Permit Threshold Counts and Emissions 

 Please refer to the electronic file " CO2e Threshold Analysis 50000 to 100000.xls" in the 

docket for EPA-HQ-OAR-20009-0517. 

 
50 

Appendix B 

Additional Supporting Data for Permit Threshold Analyses 

 Additional supporting data used to conduct the threshold analysis are included in separate 

electronic files in this docket entry (EPA-HQ-OAR-2009-0517). Please refer to the following 

file names for the additional information on specific sector categories: 

● Commercial Buildings.xlsx 

● Electricity Generation.xlsx 

● Energy Production.xlsx (includes worksheets for oil and gas and underground coal 

mining) 

● Industrial – Ammonia_Electronics_FoodProcessing_Glass.xlsx (includes worksheets for, 

ammonia production, electronics manufacturing, , food processing, and glass production) 

● Industrial – Hydrogen_Iron&Steel_Lead_Lime_Nitric Acid.xlsx (includes worksheets for 

hydrogen production, iron and steel production, lead production, lime manufacturing and 

nitric acid production) 

● Industrial Sector Petrochemical_PetroleumRefinery_Pulp&Paper.xlx (includes 

worksheets for, petrochemical production, petroleum refineries, and pulp and paper 

manufacturing) 

● Industrial – Unspecified Stationary Combustion.xlsx 

● Residential – Multi-family.xlsx 

● Waste Sector.xlsx (includes worksheets for landfills and municipal waste combustors)