March 8, 2009
TECHNICAL SUPPORT
DOCUMENT FOR REPORTING
THRESHOLDS: PROPOSED RULE
FOR MANDATORY REPORTING
OF GREENHOUSE GASES
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Table of Contents
1. Purpose 3
2. Overview of U.S. GHG Emissions 3
2.1 U.S. total by major sector (residential, commercial, agricultural, industrial,
transportation and electric power) 3
3. Overview of Applicability 5
4. Options for Determining Level at which Thresholds Apply 6
4.1 Unit-level Applicability 6
4.2 Facility-Level Applicability 7
4.3 Corporate-Level Applicability 8
5. Reporting Threshold Options 8
5.1 Capacity-Based Thresholds 9
5.2 Emissions-Based Thresholds 10
5.3 Analysis Approach 10
5.4 Capacity-based Thresholds in Electricity Generation 12
5.5 Capacity-based Thresholds in the Industrial and Agricultural Sectors 13
5.6 Capacity-based Thresholds in Unspecified Industrial Stationary Combustion 15
5.7 Emissions-based Thresholds in Electricity Generation 16
5.8 Emissions-based Thresholds in the Industrial and Agricultural Sectors 17
5.9 Emissions-based Thresholds in Unspecified Stationary Combustion 23
6. Appendix A- Supporting Data for Threshold Analyses 29
7. References 31
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1. Purpose
The purpose of this document is to provide background information in support of EPA's
decision process concerning thresholds for mandatory greenhouse gas (GHG) reporting. It
presents a summary of the research considered and a basis for the reasoning behind EPA's
threshold decisions. This document is also intended to provide the reader with an understanding
of how thresholds would apply to various reporters.
The FY08 Appropriations Act required EPA to create a reporting system covering
greenhouse gas emissions "above appropriate thresholds in all sectors of the economy." EPA has
conducted a thorough consideration of other domestic and international GHG reporting
programs, and analyses of reporters and emissions coverage at different thresholds. When
considering the thresholds, EPA has attempted to optimize the rule coverage; to capture as much
of the U.S. emissions as possible, while, at the same time, keeping the reporting burden to a
minimum and excluding small emitters.
2. Overview of U.S. GHG Emissions1
2.1 U.S. total by major sector (residential, commercial, agricultural,
industrial, transportation and electric power)
For purposes of this rulemaking, GHGs include carbon dioxide (CO2), methane (CH4),
nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride
(SF6) and other fluorinated gases (e.g., nitrogen trifluoride and hydrofluorinated ethers [HFEs]).
According to the Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2006, nearly 85
percent of the GHG emissions for 2006 were CO2 emissions, mostly from fossil fuel combustion.
GHGs derive from a cross section of the U.S. economy, including industrial, agricultural,
transportation, commercial and residential sources. The emissions originate from stationary
combustion, combustion associated with transportation, industrial processes, and fugitive
emissions. Table 2-1 presents U.S. total GHG emissions by major sector for 2006.
Combustion of fossil fuels in the United States is the largest source of GHG emissions in
the nation, producing three principal GHGs: CO2, CH4, and N2O. The nationwide GHG
emissions from stationary fossil fuel combustion are approximately 3,750 million metric tons of
CO2 equivalent (mtCC^e) per year. This estimate includes both large and small stationary
sources in the electricity generation, industrial, commercial and residential sectors, and
represents more than 50 percent of total GHG emissions in the United States. Table 2-2 presents
U.S. CO2 emissions and the individual sector contributions to the total CO2 emissions from fossil
fuel combustion. Table 2-3 presents U.S. CO2 emissions by fossil fuel type.
1 Data taken from Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2006 (EPA, 2008). All calculations
in this paper are based on gross emissions and do not include sequestration from sinks.
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Table 2-1
U.S. Greenhouse Gas Emissions Allocated to Economic Sectors
(Million Metric Tons COie)
Kconomic Sectors
200ft (J l(; Emissions
(million metric tons CO2C)
Percent oN'oUil CMC
Emissions
Electric Power Industry
2,377.8
33.7
Transportation
1,969.5
27.9
Industry
1,371.5
19.4
Agriculture
533.6
7.6
Commercial
394.6
5.6
Residential
344.8
4.9
U.S. Territories
62.4
0.8
Total
7,054.2
100
Source: U.S. EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2006 (EPA 2008).
Table 2-2
U.S. Carbon Dioxide Emissions From Fossil Fuel Combustion by Sector
(Million Metric Tons CO2)
Consuming Sectors
200ft C ()2 Emissions
(111 i 1 lion metric tons)
Percent of I'ossil I'nel
C ombustion C'(): Totsil
Electricity Generation
2,328.2
41.2
Transportation
1,856.0
32.9
Industrial
818.6
14.5
Agriculture
43.6
0.8
Commercial
210.1
3.7
Residential
326.5
5.8
U.S. Territories
62.4
1.1
Total
5,645.4
100
Source: U.S. EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2006 (EPA 2008).
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Table 2-3
U.S. Carbon Dioxide Emissions From Fossil Fuel Combustion by Fuel Type
(Million Metric Tons COie)
1'iicl Type
200ft (J l(; Emissions
(million metric tons)
Percent of lossil I'nel
C ombustion C'(): Totsil
Coal
2,065.3
37
Natural Gas
1,155.1
20
Petroleum
2,417.1
43
Total
5,637.9
-
Source: U.S. EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2006 (EPA 2008).
3. Overview of Applicability
There are several State, regional and voluntary programs in the U.S. that are proposed or
in place for the reporting of GHG emissions. EPA reviewed these programs as part of the
process of determining thresholds and reporting methodologies for the proposed rule. For
additional information about the existing U.S. programs, please see Section II of the preamble
and the review of existing programs found in the docket at EPA-HQ-OAR-2008-0508-054 and
056.
EPA also reviewed thresholds for international GHG reporting programs including those
in the EU, Australia and Canada. The EU establishes a multi-country, multi-sector CO2
emissions trading scheme. Applicability thresholds are at the facility level and are based on
production capacity; Table 3-1 summarizes categories of activities and respective thresholds
The Australian National GHG and Energy Reporting System would establish a mandatory
reporting system for corporations that exceed emissions and energy use thresholds at the
corporate level. The Canadian GHG National Reporting Program specifically targets facilities in
Canada that emit 100,000 metric tons or more of C02e annually. Additional information on
international programs can also be found in the preamble and docket materials mentioned above.
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Table 3-1
EU Emissions Trading Scheme Categories of Activities and Respective Thresholds
Acli\ ilv
Threshold
Stationary combustion (except hazardous or municipal
waste installations)
Thermal input > 20 MW (heat input capacity > 68
mmBtu/hr)
Mineral Oil Refinery
All plants
Coke ovens
All plants
Metal Ore roasting or sintering installations
All plants
Pig Iron or steel production, including continuous
casting
Capacity >2.5 metric tons/hour
Cement clinker in rotary kilns
Capacity > 500 metric tons/day
Lime in rotary kilns, or other furnaces in the mineral
industry
Capacity > 50 metric tons/day
Manufacture of glass, including glass fibre
Melting capacity > 20 metric tons/day
Manufacture of ceramic products by firing
Capacity >75 metric tons/day, and/or a kiln capacity > 4
m3 and with a setting density per kiln >300 kg/m3
Production of pulp from timber or other fibrous
materials
All plants
Production of paper and board
Capacity of > 20 metric tons/day
Source: "Categories of Activities Referred to in Articles 2(1), 3, 4, 14(1), 28 and 30," Annex 1, Official Journal of
the European Union, 25.10.2003, L 275/42.
4. Options for Determining Level at which Thresholds Apply
One of the first questions EPA reviewed was whether the thresholds should apply at the unit-
level, the facility-level or the corporate-level. The determination of the most appropriate entity
level for applying the threshold determination for the GHG emissions reporting rule should
account for the objectives of the rule, the compatibility with existing EPA programs, and the
administrative requirements of each option. EPA could use a combination of entity levels based
on the advantages of each for different source categories. The advantages and/or disadvantages
of each option, as well as uses in similar programs, are discussed below.
4.1 Unit-level Applicability
Unit-level applicability is used in several current EPA programs for criteria pollutants,
and is generally considered most appropriate if unit emissions are going to be measured against a
performance standard. For example, the New Source Performance Standard (NSPS) programs in
40 CFR Part 60 sets applicability at the unit level by source category. If a program's regulations
are built on regulating a wide range of equipment capacities, then it makes sense to target certain
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units. Another example is the Acid Rain Program and its unit-level threshold determination
based on units serving a generator with a nameplate capacity greater than or equal to 25
megawatts.
As most large electricity generating stations have small backup or auxiliary boilers or
engines on site, this threshold would exclude such units from the program. Unit-level threshold
determinations are traditionally applied when the universe of affected sources by the program are
very well known in advance of the program's development. Using the Acid Rain Program as an
example again, the electricity generation sector contains a well known universe of sources,
because of the oversight needs for the efficient operations of the U.S. electricity grid. Therefore,
a unit-level threshold determination was possible. However, if sufficient data are not known in
advance of a program's development, a unit-level threshold determination could prove difficult
to define. As described in subsequent sections limited unit-level capacity data was available for
the universe of sources expected to be affected by this rule.
One drawback of a unit level applicability is that sometimes smaller units are not
included in a threshold determination where if the applicability was set at a facility level the
emissions from all units would be included.
4.2 Facility-Level Applicability
Facility-level applicability is based on operations within a contiguous boundary. If, for
example, an emissions threshold is used to determine applicability then it may include the sum of
onsite direct emissions. Facility-level applicability provides a number of advantages over both
unit-level and corporate-level. It is consistent with other existing mandatory GHG reporting
programs, such as the California Air Resources Board (CARB) GHG reporting rule, Canada's
National GHG Reporting Program and the EU's Emissions Trading System. The reporting of
criteria and hazardous air pollutant emissions to the National Emissions Inventory (NEI) captures
data down to the process level for the entire facility. As such, a large amount of information
already exists on the types of facilities in the U.S.
If the determination of applicability requires a calculation, such as the sum of annual
emissions, then it is often easier to aggregate to the facility level. Sources can capture fuel
consumption data and other reporting inputs data at logical collection points like fuel flow
meters, CEMS, or refinery gas systems without having to handle issues such as unit
apportionment. This is particularly true for complex industrial processes, e.g., ammonia
manufacture, where separation of 'unit' level emissions is difficult.
One drawback to facility-level greenhouse gas emissions applicability is that sources may
define facility differently. For example, one refinery may consider a related power plant as 'off-
site' while another refinery with a similar configuration may treat the power plant as part of the
facility. Further, for some source categories it may be difficult to define a facility, or facility
level reporting would not be consistent with current business practices (e.g., importers and
exporters of fuels).
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4.3 Corporate-Level Applicability
Applying the threshold at the corporate level would encompass facilities, subsidiaries and
other business units in accordance with organizational boundaries, i.e., either operational or
financial control. The WRI/WBCSD GHG Protocol is a commonly referenced approach to
corporate accounting that would be useful in defining the level at which a threshold should
apply, although the protocol itself does not apply thresholds. This approach has a key
disadvantage; it would rely on the EPA tracking changes in complex ownership structures over
time.
Despite these complexities, corporate level applicability has advantages for some
upstream source categories, e.g., fuel importers and manufacturers of vehicles and engines. Fuel
importers, for example, could be required to report based on the complete combustion or
oxidation of their corporate sales, as opposed to their many small consumers.
The level at which the threshold would be applied (unit, facility or corporate) must be
distinguished from reporting and recordkeeping requirements. Even if applicability is
determined at the facility level, sources still may be required to keep records of the data used to
calculate the GHG emissions for each unit or activity, categorized by fuel or material type.
5. Reporting Threshold Options
Given the advantages described above for facility level reporting, we considered three
types of facility reporting thresholds for the various source categories:
1. An equipment capacity-based threshold such as nameplate megawatt capacity or
maximum heat input rating;
2. An emissions-based threshold of 1,000, 10,000, 25,000, or 100,000 metric tons C02e
annually;
3. A source category based threshold, where every source in the category is subject to
reporting ('all in').
To evaluate different threshold levels, we collected available data and analyzed the
implication of various thresholds in terms of number of facilities and level of emissions covered
at the national level while considering the following objectives:
• Comprehensive economy wide coverage of both combustion and process emissions with
sufficient detail to support a wide range of future policy options;
• Minimal impact on commercial and residential sectors, small businesses and public
facilities such as schools;
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• Alignment with state, regional, and international mandatory GHG reporting program
thresholds, where feasible; and
• Equivalence between capacity and emission thresholds if both are employed.
5.1 Capacity-Based Thresholds
Capacity-based thresholds are used in a number of EPA regulatory programs including
the previously noted Acid Rain Program and Title V. One of their chief advantages is the
simplification of applicability determination. Facility or unit capacity, unlike emissions, does
not change year to year. A source should know whether they are in or out of a program simply
by reviewing their equipment inventory.
Capacity-based thresholds can refer to either input capacity or rating, for example, in
mmBtu/hr or output capacity. They may use either the potential to emit (operating at full
capacity every hour of the year) or a capacity factor (actual operating level divided by full
capacity). Table 5-1 summarizes potential to emit CO2 at four heat input capacity thresholds for
various fuels. To capture facilities with the potential to emit 25,000 metric tons CO2 annual
emissions, for example, would require a heat input capacity threshold of 50 mmBtu/hr for natural
gas fired equipment.
Table 5-1
Equipment Heat Input Capacity and Emission Thresholds (Estimates Based on CO2 Only)
I'uel Type
CO:
1^ mission
Tiiclor (k«i
C ()2/ni 11115l 11)
Cosil
Kqiiipme
1.000
mcl ni-
tons CO;
Threshold
iihI C oke
ill lle.il Inpi
10.000
mot ni-
tons CO;
Threshold
t Ciip:ii'ity (1
25.000
metric tons
CO;
Threshold
1111 lit n/li r)
100.000
metric tons
CO;
Threshold
Anthracite
103.62
1.1
11.02
27.54
110.17
Bituminous
93.46
1.22
12.21
30.54
122.14
Sub-bituminous
97.09
1.18
11.76
29.39
117.58
Lignite
96.43
1.18
11.84
29.6
118.38
Unspecified
(Residential/Commercial)
95.33
1.2
11.97
29.94
119.75
Unspecified (Industrial Coking)
93.72
1.22
12.18
30.45
121.8
Unspecified (Other Industrial)
93.98
1.21
12.15
30.37
121.47
Unspecified (Electric Power)
94.45
1.21
12.09
30.22
120.86
Coke
102.12
1.12
11.18
27.95
111.79
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Niilui'iil (ijis (IK llcitl ConU'iit)
Unspecified (Weighted U.S.
Average)
53.06
2.15
21.51
53.79
215.14
IVlrok'iim Products
Diesel Fuel/Distillate Fuel Oil (#1,2
& 4)
73.15
1.56
15.61
39.01
156.06
Jet Fuel
70.88
1.61
16.11
40.26
161.05
Kerosene
72.31
1.58
15.79
39.47
157.87
LPG (energy use)
63.03
1.81
18.11
45.28
181.11
Gasoline (Motor Gasoline)
70.88
1.61
16.11
40.26
161.05
Residual Fuel Oil (#5 & 6)
78.80
1.45
14.49
36.22
144.87
Heat input capacity calculation assumes 100% oxidation of C to C02.
Source: U.S. EPA, Inventory of Greenhouse Gas Emissions and Sinks: 1990-2005 (2007), Annex 2.1, Tables A-31,
A-32, A-35, and A-36.
5.2 Emissions-Based Thresholds
An emissions-based threshold approach requires a calculation to determine applicability.
Because emissions can change from year to year so may applicability, depending on the
program's design. This issue may necessitate provisions to handle 'drop ins' and 'drop outs'.
The former are sources with emissions under a threshold in the first year but over in a future
year. The latter could be sources whose emissions fall in the future by curtailing operations or
by instituting efficiency measures. Alternatively, a program might include a "once-in-always-in"
provision, whereby once a facility is subject to the reporting rule, they must always report,
regardless of future emissions levels. Such a provision ensures greater comparability in the
number of reporters from year to year.
EPA evaluated GHG emission based facility thresholds of 1,000, 10,000, 25,000, and
100,000 metric tons C02e per year. EPA applied these thresholds to existing publicly available
datasets that cover general stationary combustion, as well as to facility-level emissions estimates
generated for specific emissions- intensive source categories. Unlike emissions-intensive source
categories typified by a relatively small number of large industrial facilities, general stationary
combustion is distributed throughout the economy in electricity generation, industrial,
commercial and residential sectors (see Table 2-2). These represent a very large number of
potential sources which together emit significant combustion GHG emissions.
5.3 Analysis Approach
Emissions and facility data sufficient to support a complete threshold analysis is currently
unavailable. The data needed to fully conduct such as an analysis are precisely the data that
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would be reported through a mandatory GHG reporting program. We compared the threshold
options to existing criteria pollutant reporting thresholds in the NEI. We also made estimates of
commercial building and industrial facility populations and emissions coverage where possible,
while noting that this methodology also yields uncertain results. Because of the paucity of
national facility-level GHG emissions data we reviewed the draft CARB dataset used during the
development of their reporting rule.
Given current data availability, slightly different approaches to the threshold analysis were
undertaken for three classes of source categories: electricity generation, source-specific
categories in the industrial and agricultural sectors, and unspecified stationary combustion. EPA
research and proprietary databases provided information on some industries. (Ventyx, Velocity
Suite®, 2008)
Electricity generation bears consideration both due to its magnitude and to the availability of
capacity and CO2 emissions data from EPA's Acid Rain Program (ARP). Facilities in the ARP
are responsible for over 90% of electricity generation CO2 emissions. They are required to
monitor and report emissions under 40 CFR Part 75; over 80% of electricity sector CO2
emissions are measured by continuous emissions monitoring systems. For non-ARP electricity
generation facilities, CO2 emissions can be estimated from Energy Information Administration
(EIA) facility fuel usage.
Other industrial and agricultural sources do not report fuel usage and/or GHG emissions to
EPA in a comprehensive manner, if at all. Therefore to determine the appropriate thresholds for
this rulemaking, EPA carried out separate threshold analyses for emissions-intensive source
categories (e.g., cement, iron and steel, coal mines, landfills, etc). These source categories are
generally characterized by a limited number of facilities (less than a dozen to a couple of
hundred), and relatively high emissions per facility. Absent facility emissions or production
data, emissions estimates can be generated using known operating parameters (e.g., production
capacity, sales) and applying assumptions to generate emissions (e.g., emission factor, capacity
utilization, operating hours, etc).
Unspecified stationary combustion refers to sources that are only covered under the General
Stationary Fuel Combustion subpart of the rule. These unspecified sources are found in
industrial activities ranging from chemicals to mining to manufacturing. EPA knowledge of
these facilities is far from complete. The U.S. Census estimates the total population of
commercial and industrial establishments at approximately 360,000. Nearly all of these sources
emit some GHGs, but a large majority are likely to be subject only to the lowest emissions
threshold under consideration here (1,000 mtC02e per year). The number of process emission
intensive facilities (see Table 5-8) is approximately 10,000 combined - a number that is
relatively insensitive to threshold options due to the large size of such facilities. The number of
unspecified industrial combustion facilities, on the other hand, is quite sensitive to threshold
options. The emphasis on industrial rather than commercial establishments is explained further
below.
CO2 emissions from the combustion of biogenic fuels were excluded from the threshold
analysis, and the threshold analysis for the unspecified stationary combustion sources only
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include CO2 emissions from fossil fuel combustion and CH4 and N2O emissions from all fuels
combusted. The exclusion of biomass emissions is consistent with the IPCC and other GHG
reporting programs. Biogenic CO2 emissions from biomass combustion are considered
separately because it is assumed that the carbon released during stationary source combustion of
biomass is recycled as U.S. forests and crops regenerate.
5.4 Capacity-based Thresholds in Electricity Generation
The EPA's EGrid database of electricity generation in the United States, summarized in
Table 5-1, lists a total of 3,243 facilities with 2,438 mtCC^e emissions in 2004. Note that the
EGrid CO2 emissions total exceeds the EPA GHG Inventory electric power sector emissions of
2,377.8 mtC02e in Table 2-1 due to the categorization of industrial cogeneration units (which are
included in the industrial sector in the U.S. GHG inventory report). The EGrid data
demonstrates that the distribution of emissions in electricity generation is weighted towards the
largest facilities - those with a nameplate capacity exceeding 25 megawatts. Over 99% of C02e
emissions are from the 59.3 percent of the facilities in that group. If one of the objectives of a
mandatory GHG reporting program is to focus on large emitters, a capacity-based threshold for
electricity generation facilities of 25 megawatts or higher would appear to meet that criteria.
However, such a threshold could have the effect of exempting significant sources of GHGs. For
example, a coal-fired 24 megawatt electricity generation plant operating at near capacity could
emit over 200,000 mtCC^e annually - double the highest emissions threshold under
consideration here. Therefore, a facility capacity threshold of 25 megawatts for electricity
generators would have the effect of excluding sources well above the 100,000 mtCC^e emissions
threshold
Table 5-2
EGrid Facilities and Emissions by Megawatt Capacity 2004
Facility Nameplate
Megawatt Capacity
Number of Facilities
(total 3,243)
Total Emissions
Million mtC02e
(total 2438)
Coverage
Emissions
Facilities
0-5MW
532
1
0.0%
16.3%
5-10MW
350
2
0.1%
10.8%
10-25MW
437
7
0.3%
13.5%
>25MW
1,924
2,427
99.6%
59.3%
Conversely, a large number of electricity generation units have a capacity over 25 MW,
but are operated infrequently. This is due, in part, to the presence of peak generation units with
low operating hours. If one of the objectives of a mandatory GHG reporting program is to focus
on large emitters, a capacity-based threshold for electricity generation facilities of 25 megawatts
could include facilities that are emitting GHGs at a lower annual total than would otherwise be
indicated by the maximum capacity rating. A principal disadvantage of capacity thresholds in
this source category is the inclusion of such facilities.
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The CARB reporting rule addresses this issue by using a combined one MW capacity and
2,500 mtC02e annual threshold for electricity generating facilities. The 2,500 mtCC^e is roughly
the amount of GHG emissions from a one megawatt gas-fired unit running 50 percent of the
year. Applied nationally the CARB approach would improve coverage to 99% of the EGrid
dataset while increasing the number of reporters to 2,052. Other emissions-based options are
discussed below.
5.5 Capacity-based Thresholds in the Industrial and Agricultural
Sectors
Unlike electricity generation, capacity and emissions data for most other industrial
facilities is unavailable. EPA analyzed capacity-based thresholds for several source categories
where voluntary programs in the industrial and agricultural sectors provided the necessary data.
For some source categories EPA applied simplified emissions calculation procedures using
default emission factors to back-calculate the corresponding capacity-based threshold from a
given emissions-threshold. Tables 5-3 and 5-4 summarize the source categories for which
capacity-based threshold were assessed. Note that the "Units" used to calculate capacities are
unique to each industry. The capacity-thresholds presented in Table 5-2 correspond to
emissions-based thresholds of 1,000, 10,000, 25,000 and 100,000 mtCC^e. Establishing such
capacities requires in depth knowledge of each category's processes and manufacturing methods.
One of the shortcomings to using such thresholds is the difficulty in achieving equivalence
across the broad range of industries. Additional information for specific source categories may
be found in the Appendices to this TSD and the corresponding Technical Support Documents
(TSDs) for the industries.
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Table 5-3. Summary of Impacts of Selected Capacity-based Thresholds on Industrial and Agricultural Source Categories
Source Category
Capacity
Based
Threshold
Units
Total National
Emissions
(mtC02e)
Total
Number
of
Facilities
Emissions Covered
Facilities Covered
mtC02e/yr
Percent
Number
Percent
Aluminum
64
mt Al/year
6,402,000
14
6,402,000
100%
14
100%
640
14
6,402,000
100%
14
100%
1,594
14
6,402,000
100%
14
100%
6,378
14
6,402,000
100%
14
100%
Electronics: Semi-
conductors
1,080
silicon m2
5,741,676
175
5,492,066
96%
91
52%
Electronics:
MEMs
1,020
silicon m2
146,115
12
96,164
66%
2
17%
Electronics: LCD
235,700
LCD m2
23,632
9
0
0%
0
0%
Fluorinated Gas
Production
(Fugitives)
50,000
mtC02e
5,300,000
12
5,300,000
100%
12
100%
500,000
12
5,300,000
100%
12
100%
1,250,000
12
5,300,000
100%
12
100%
5,000,000
12
5,200,000
98%
10
83%
HCFC-22
Production
2
HCFC-22
capacity
(tons)
13,848,483
3
13,848,483
100%
3
100%
21
3
13,848,483
100%
3
100%
53
3
13,848,483
100%
3
100%
214
3
13,848,483
100%
3
100%
Hydrogen
116
h2
Capacity
(tons)
15,226,620
77
15,225,220
100%
73
95%
1,160
77
15,130,255
99%
51
66%
2,900
77
14,984,365
98%
41
53%
11,600
77
14,251,265
94%
30
39%
Magnesium
26
mt
Mg/year
3,200,000
13
2,954,559
92%
13
100%
262
13
2,949,732
92%
12
92%
656
13
2,949,732
92%
12
92%
2,622
13
2,780,717
87%
9
69%
SF6 from Electrical
Equipment
713
lbs SF6
12,400,000
1,364
12,190,000
98%
578
42%
7,128
1,364
10,960,000
88%
183
13%
17,820
1,364
10,320,000
83%
141
10%
71,280
1,364
5,950,000
48%
35
3%
Underground
Coal Mines
100,000
cubic feet
CH4 per
day
39,520,000
612
33,945,956
86%
128
21%
Landfills
1,000
Generation
111,100,000
7,800
110,800,000
99.7%
6,830
88%
10,000
7,800
104,400,000
94%
3,484
45%
25,000
7,800
91,100,000
82%
2,551
33%
100,000
7,800
65,600,000
59%
1,038
13%
14
-------
Table 5-4. Animal Head Estimates for Manure Management*
Threshold Levels (mtC02e)
1,000
10,000
25,000
100,000
Total number of head to meet threshold
Beef
3,500
35,500
89,000
356,000
Dairy
200
2,000
5,000
20,000
Swine
3,000
29,000
73,000
291,500
Poultry
39,500
358,000
895,000
3,580,000
^Estimates exclude stationary combustion
5.6 Capacity-based Thresholds in Unspecified Industrial Stationary
Combustion
The EPA's National Emissions Inventory contains a comprehensive list of over 60,000
facilities but information on capacity or fuel usage may be fragmentary and GHG emissions are
not included.
In 2005, EPA conducted a characterization of the U.S. boiler population. In the absence
of corresponding emissions data it is impossible to conclude from this study how input capacity
thresholds would affect national coverage. However, the results provide some sense of the boiler
population scale and makeup. The study, summarized below in Table 5-5, estimated that there
are over 162,000 manufacturing and commercial boilers in the United States. The majority of
small boilers are commercial; large boilers (> 250 mmBtu/hr) are primarily found in
manufacturing installations.
Table 5-5
U.S. Indusl
trial/Commercial Boiler Population, 2005
Unit Capacity
mmBtu/hr
Manufacturing
Boilers
Commercial
Boilers
Total
> 10
23,495
93,650
117,145
10 to 50
12,380
21,850
34,230
50 to 100
3,570
3,040
6,610
100 to 250
2,210
1,120
3,330
> 250
1,360
130
1,490
Total
43,015
119,790
162,805
By comparison the EU ETS specifies an input capacity threshold of 68 mmBtu/hr for
general stationary combustion facilities. The U.S. boiler study would indicate that
approximately 11,400 boilers > 50 mmBtu/hr could be subject to such a threshold. Note that this
estimate contains considerable uncertainty because of the possible incompleteness of the boiler
study. The study also included only boilers - it did not address other stationary combustion
units such as turbines and process heaters.
15
-------
Due to the lack of data on unspecified industrial stationary combustion, EPA made no
other evaluation of the effect of capacity-based thresholds on either the number of affected
facilities or national emissions coverage.
5.7 Emissions-based Thresholds in Electricity Generation
Emissions-based thresholds target facilities with actual emissions as opposed to the
potential to emit. Table 5-6 summarizes EGrid facilities and CO2 emissions by four threshold
options: 1,000, 10,000, 25,000 and 100,000 mtCC^e per year. All four options exceed 98.9% in
emissions coverage. The highest option, 100,000 mtCC^e, would affect 1,097 facilities; the
lowest, 1,000 mtC02e, more than doubles that to 2,242 facilities while gaining 1% in national
coverage.
Table 5-6
Emissions-based Options: EGrid Emissions in 2004
Threshold Level
mtC02e/yr
Number of Facilities
(total 3,243)
Total Emissions
Million mtC02e
(total 2,438)
Coverage Percent
Emissions
Facilities
1,000 MT C02e
2,242
2,438
100.0%
69.1%
10,000 MT C02e
1,750
2,436
99.9%
54.0%
25,000 MT C02e
1507
2,432
99.8%
46.5%
100,000 MT C02e
1,097
2,410
98.9%
33.8%
Since ARP includes only larger facilities the difference between options is less
pronounced. The results are summarized in Table 5-7. Moving from the 100,000 to the 1,000
mtC02e threshold increases the number of affected ARP facilities from 807 to 1,155 (out of
1,213 total) but has only a negligible effect on emissions coverage since it exceeds 99% in all
cases.
Electricity generation is the only stationary combustion source category where excess
capacity is required by regulation. An advantage of an emissions-based threshold is that it will
effectively target those facilities with actual emissions in the subject year. On the other hand, it
will not account for the potential variance in electricity demand in subsequent years. CARB's
approach, noted above, is to apply both a capacity and an emissions-based threshold to electricity
generators.
Table 5-7
Emissions-baset
Options: Acid Rain Program Facility Emissions in 2006
Threshold Level
mtC02e/yr
Number of Facilities
(total 1,213)
Total Million
mtC02e
(total 2,267.6)
Coverage Percent
Emissions
Facilities
1,000 mtC02e
1,155
2,267.6
100%
95%
10,000 mtC02e
1,071
2,267.1
100%
88%
25,000 mtCC^e
983
2,265.7
100%
81%
100,000 mtC02e
807
2,256.2
99%
67%
Source: EPA's Data and Maps Website, June 2008
16
-------
5.8 Emissions-based Thresholds in the industrial and Agricultural
Sectors
EPA conducted an emissions-based threshold analysis for several source categories in the
industrial and agricultural sectors. The threshold analysis for most sources included stationary
combustion, process and fugitive-related emissions. Landfills and wastewater treatment
operations that are co-located with industrial facilities were considered in separate threshold
analyses of the respective industrial sources due to lack of data.
As noted above, facility-specific GHG emissions data were not available. The method to
generate the emissions estimates for the threshold varied slightly by source category. In general
a four step process was conducted for each industry:
1. Define facility population and characteristics (in particular, production based on
capacity);
2. Estimate combustion emissions per facility;
3. Estimate process or fugitive emissions per facility; and
4. Compare the sum of the combustion and process emissions to the threshold levels.
The general approach for each of these steps is described below. Table 5-8 presents
specifics for each sector.
Define facility population and characteristics (in particular, production based on capacity)
For each industry, EPA generally identified individual facilities using publicly available
data. For most sources, facility-level production data was not available; hence, reported capacity
data was obtained for each facility. Facility level production was estimated by scaling the
capacity using the ratio of national production to national capacity. For example, key data
sources associated with minerals were the USGS Minerals Yearbook and personal conversations
with the USGS Minerals Commodity Specialists. For other industrial sources reports prepared
by industry groups provided valuable information. For coal, oil and gas operations, primary
data sources for facility population and characteristics were the U.S. Energy Information
Administration (EIA), Mine Safety and Health Administration, Mineral Management Service,
the Gas Processing Survey (OGJ 2006), and the Federal Energy Regulatory Commission.
Estimate combustion emissions per facility
For most sources, EPA estimated emissions from on-site combustion of fossil fuels at
stationary sources based on the estimated energy requirements of the constituent facilities and
fuel-specific emission factors. The approach to estimate energy requirements for constituent
facilities consisted of either:
1. Building an energy-requirements profile for facilities that had publicly accessible Title V
permits. Title V permits list the reporting facility's stationary devices along with the
energy requirements of the device and the fuel type consumed. This information was
used to build an energy-requirements profile for the reporting facility assuming that the
devices operated at 90 percent of capacity throughout the year. For facilities that did not
17
-------
have publicly accessible Title V permits, energy-requirements profiles for facilities with
similar production capacities were applied.
2. Approximating the energy requirements of a facility based on the facilities commodity
production and the energy intensity per unit of production (e.g., MMBtu/ton).
3. Approximating energy requirements using national data from the EIA Manufacturing
Energy Consumption Survey (MECS). MECS data provided total national energy
consumption by fuel type, which was divided by the number of facilities within the
source to obtain facility-level energy requirements (U.S. DOE 2005).
Fuel-specific CO2 emission factors for on-site fossil fuel combustion were derived using heat
content and carbon content data contained in the Inventory of U.S. Greenhouse Gas Emissions
and Sinks 1990-2006 (U.S. EPA 2008). CH4 and N2O emission factors were derived from Table
2.3 of the 2006IPCC Guidelines for National Greenhouse Gas Inventories (IPCC 2006).
Estimates of fuel combustion emissions from the coal mining sector were based on fuel
consumption in the sector by fuel type, as reported by the Bureau of the Census for 2002.
Emissions were allocated to each mine in proportion to coal production.
Estimate process or fugitive emissions per facility. For most industries, process and
fugitive emissions were estimated based on estimated facility level production and application of
a default emission factor.
Compare the sum of the combustion, process and fugitive emissions to the threshold
levels. The total emissions for each facility were compared to the threshold and the number of
facilities that exceeded the designated threshold was summed.
For several industrial sources (e.g. adipic acid, ammonia, cement, nitric acid) nearly all
facilities exceed all reviewed thresholds. For the large remainder of source categories, most
facilities in a given industry would exceed all but a 100,000 mtCC^e threshold. Only in limited
circumstances (e.g., electronics, glass, hydrogen) is a relatively significant difference in coverage
seen in moving from a 10,000 mtC02e threshold to a 25,000 mtC02e threshold.
Landfills provide a useful example of achieving a balance between emissions coverage
and the number of facilities affected. Landfills have the largest number of facilities of all
industries included in Table 5-8, are a significant source of emissions, and are the most sensitive
to threshold options. For additional information, please see the Landfills TSD found at EPA-
HQ-OAR-2008-0508-034.
18
-------
Table 5-8
Summary of Impacts of Selected Emissions-based Thresholds on Source Categories
Source Category
Threshold
Total National
Emissions
Total
Number
of
Facilities
Emissions Covered
Facilities Covered
Level
mtC02e/yr
(mtC02e)
Million
mtC02e/yr
Percent
Number
Percent
Adipic Acid
1,000
9,300,000
4
9,300,000
100%
4
100%
10,000
9,300,000
100%
4
100%
25,000
9,300,000
100%
4
100%
100,000
9,300,000
100%
4
100%
Aluminum
1,000
6,402,000*
14
6,402,000
100%
14
100%
10,000
6,397,000
99.9%
13
93%
25,000
6,397,000
99.9%
13
93%
100,000
6,397,000
99.9%
13
93%
Ammonia
1,000
14,543,007
24
14,543,007
100%
24
100%
10,000
14,543,007
100%
24
100%
25,000
14,543,007
100%
24
100%
100,000
14,449,519
99%
22
92%
Cement
1,000
86,830,000
107
86,830,000
100%
107
100%
10,000
86,830,000
100%
107
100%
25,000
86,830,000
100%
107
100%
100,000
86,740,000
99.9%
106
99.9%
Electronics
1,000
5,984,462*
216
5,972,909
99.8%
173
80%
10,000
5,840,411
98%
118
55%
25,000
5,708,283
95%
96
44%
100,000
4,708,283
79%
54
25%
Ethanol
1,000
NE
140
NE
NE
>101
>72%
10,000
NE
NE
>94
>67%
25,000
NE
NE
>86
>61%
100,000
NE
NE
>43
>31%
Ferroalloys
1,000
2,343,990
9
2,343,990
100%
9
100%
10,000
2,343,990
100%
9
100%
25,000
2,343,990
100%
9
100%
100,000
2,276,639
97%
8
89%
Fluorinated Gas
Production (Fugitives)
1,000
5,300,000*
12
5,300,000
100%
12
100%
10,000
5,300,000
100%
12
100%
25,000
5,300,000
100%
12
100%
100,000
5,100,000
97%
9
75%
Food Processing
1,000
NE
5,719
NE
NE
802
14%
10,000
NE
NE
170
3%
25,000
NE
NE
100
1.7%
100,000
NE
NE
10
0.2%
19
-------
Glass
1,000
4,425,269
374
4,336,892
98%
217
58%
10,000
4,012,319
91%
158
42%
25,000
2,243,583
51%
55
15%
100,000
207,535
5%
1
0.30%
Hydrogen
1,000
15,226,620
77
15,225,220
100.00%
73
95%
10,000
15,130,255
99%
51
66%
25,000
14,984,365
98%
41
53%
100,000
14,251,265
94%
30
39%
Iron and Steel
1,000
85,150,877
130
85,150,877
100%
130
100%
10,000
85,141,500
-100%
128
98%
25,000
85,013,059
-100%
121
93%
100,000
84,468,696
99
111
85%
Lead
1,000
866,000
27
859,000
99%
17
63%
10,000
853,000
98%
16
59%
25,000
798,000
92%
13
48%
100,000
0
0
0
0%
Lime
1,000
25,421,043
89
25,421,043
100%
89
100%
10,000
25,396,036
99.9%
86
97%
25,000
25,371,254
99.8%
85
96%
100,000
23,833,273
94%
52
58%
Magnesium
1,000
3,200,000*
13
2,954,559
92%
13
100%
10,000
2,939,741
92%
11
85%
25,000
2,939,741
92%
11
85%
100,000
2,872,982
90%
9
69%
Nitric Acid
1,000
17,731,650
45
17,731,650
100%
45
100%
10,000
17,723,576
99.9%
44
98%
25,000
17,706,259
99.9%
43
96%
100,000
17,511,444
99%
40
89%
Petroleum and Natural Gas
Industry: Offshore Petroleum
& Gas Production Facilities
1,000
10,000
10,162,179
2,525
9,783,496
96%
1,021
40%
6,773,885
67%
156
6%
25,000
5,138,076
51%
50
2%
100,000
3,136,185
31%
4
0.5%
Petroleum and Natural Gas
Industry: Natural Gas
Processing Facilities
1,000
50,211,548
566
50,211,548
100%
566
100%
10,000
49,207,852
98%
394
70%
25,000
47,499,976
95%
287
51%
100,000
39,041,555
78%
125
22%
Petroleum and Natural Gas
Industry: Natural Gas
Transmission Compression
Facilities
1,000
73,198,355
1,944
73,177,039
100%
1,659
85%
10,000
71,359,167
97%
1311
67%
25,000
63,835,288
87%
874
45%
100,000
30,200,243
41%
216
11%
Petroleum and Natural Gas
Industry: Underground
Natural Gas Storage Facilities
1,000
11,719,044
398
11,702,256
100%
346
87%
10,000
10,975,728
94%
197
49%
25,000
9,879,247
84%
131
33%
100,000
5,265,948
45%
35
9%
Petroleum and Natural Gas
Industry: LNG Storage
1,000
1,956,435
157
1,940,203
99%
54
34%
10,000
1,860,314
95%
39
25%
20
-------
Facilities
25,000
1,670,427
85%
29
18%
100,000
637,477
33%
3
2%
Petroleum and Natural Gas
Industry: LNG Import and
Export Facilities
1,000
1,896,626
5
1,896,626
100%
5
100%
10,000
1,895,153
99.9%
4
80%
25,000
1,895,153
99.9%
4
80%
100,000
1,895,153
99.9%
4
80%
Petrochemicals
1,000
54,830,000
88
53,830,000
100%
88
100%
10,000
53,820,000
99.98%
87
98.90%
25,000
53,820,000
99.98%
87
98.90%
100,000
53,440,000
99.70%
84
95.50%
Petroleum Refineries
1,000
204,750,000
150
204,750,000
100%
150
100
10,000
204,740,000
100%
149
99%
25,000
204,690,000
100.0%
146
97%
100,000
203,750,000
99.5%
128
85%
Phosphoric Acid
1,000
3,838,036
14
3,838,036
100%
14
100%
10,000
3,838,036
100%
14
100%
25,000
3,838,036
100%
14
100%
100,000
3,838,036
100%
14
100%
Pulp and Paper
1,000
57,700,000
425
57,700,000
100%
425
100%
10,000
57,700,000
100%
425
100%
25,000
57,700,000
100%
425
100%
100,000
57,527,000
99.7%
410
96%
Silicon Carbide
1,000
109,271
1
109,271
100%
1
100%
10,000
109,271
100%
1
100%
25,000
109,271
100%
1
100%
100,000
109,271
100%
1
100%
Soda Ash
1,000
3,121,438
5
3,121,438
100%
5
100%
10,000
3,121,438
100%
5
100%
25,000
3,121,438
100%
5
100%
100,000
3,121,438
100%
5
100%
SF6 from Electrical
Equipment
1,000
12,400,000*
1,364
12,200,000
98%
564
41%
10,000
10,870,000
88%
158
12%
25,000
10,110,000
82%
111
8%
100,000
5,840,000
47%
27
2%
Titanium Dioxide
1,000
3,685,777
8
3,685,777
100%
8
100%
10,000
3,685,777
100%
8
100%
25,000
3,685,777
100%
8
100%
100,000
3,628,054
98%
7
88%
Underground Coal
Mines
1,000
39,520,000
612
33,945,446
86%
125
20%
10,000
33,926,526
86%
122
20%
25,000
33,536,385
85%
100
16%
100,000
31,054,856
79%
53
9%
Zinc
1,000
851,708
9
851,708
100%
9
100%
10,000
843,154
99%
8
89%
25,000
801,893
94%
5
56%
100,000
712,181
84%
4
44%
21
-------
Landfills
1,000
111,100,000
7,800
110,800,000
99.70%
6,827
88%
10,000
102,800,000
93%
3,060
39%
25,000
82,400,000
74%
1,926
25%
100,000
39,300,000
35%
441
6%
Upstream: Coal
Suppliers
1,000
2,153,000,000
1,365
2,146,000,000
99.7%
1,346
99%
10,000
2,146,000,000
99.7%
1,237
91%
25,000
2,144,000,000
99.6%
1,117
82%
100,000
2,130,000,000
99%
867
64%
Upstream: Petroleum
Product Suppliers
(Refineries)
1,000
2,447,738,368
140
2,447,738,368
100%
140
100%
10,000
2,447,738,368
100%
140
100%
25,000
2,447,738,368
100%
140
100%
100,000
2,447,738,368
100%
140
100%
Upstream: Petroleum
Product Suppliers
(Importers)
1,000
393,294,390
224
393,291,916
>99.9%
219
98%
10,000
393,171,144
>99.9%
193
86%
25,000
392,895,841
99.9%
175
78%
100,000
389,628,252
99%
120
54%
Upstream: LDC's
1,000
632,100,851
1,207
632,004,022
99.98%
1,022
85%
10,000
630,106,725
99.7%
521
43%
25,000
627,543,971
99%
365
30%
100,000
619,456,607
98%
206
17%
Upstream: NGL from
Processing Plants
1,000
164,712,077
566
164,704,346
100%
466
82%
10,000
164,404,207
100%
400
71%
25,000
163,516,733
99%
347
61%
100,000
157,341,629
96%
244
43%
Upstream: HFC,PFC,
SF6, and NF3 Producers
1,000
350,000,000
12
350,000,000
100%
12
100%
10,000
350,000,000
100%
12
100%
25,000
350,000,000
100%
12
100%
100,000
350,000,000
100%
12
100%
Upstream: N20
Producers
1,000
4,500,000
5
4,500,000
100%
5
100%
10,000
4,500,000
100%
5
100%
25,000
4,500,000
100%
5
100%
100,000
4,500,000
100%
5
100%
Upstream: N20 and
Fluorinated GHG
Importers (bulk)
1,000
110,024,979
116
110,024,987
100%
111
96%
10,000
109,921,970
99.9%
81
70%
25,000
109,580,067
99.6%
61
53%
100,000
108,703,112
99%
44
38%
C02 Supply from
Industrial Facilities or
Process Units
1,000
8,186,881
9
8,186,881
100%
9
100%
10,000
8,186,881
100%
9
100%
25,000
8,186,881
100%
9
100%
100,000
8,038,478
98%
5
56%
C02 Supply from C02
Production Wells
1,000
31,358,853
4
31,358,853
100%
4
100%
10,000
31,358,853
100%
4
100%
25,000
31,358,853
100%
4
100%
100,000
31,358,853
100%
4
100%
^Threshold analysis did not include combustion-related emissions.
22
-------
5.9 Emissions-based Thresholds in Unspecified Stationary
Combustion
5.9.1 Comparison to NEI Reporting Thresholds
EPA compared options to existing criteria pollutant reporting thresholds in the NEI. States
report criteria and hazardous air pollutant emissions data for over 60,000 stationary source
facilities to EPA for the NEI. Under the Consolidated Emissions Reporting Rule (CERR), the
minimum facility criteria pollutant reporting threshold for state reporting of facility emissions to
the NEI is 100 short tons of a criteria air pollutant.2 . Table 5-9 shows the equivalent amount of
criteria pollutant emissions that would be released when a fossil fuel combustion source emits
CO2 at the levels considered at the various GHG thresholds. To simplify the analysis we did not
estimate the small amounts of CH4 and N2O emissions. The criteria pollutant with the highest
quantity of expected emissions per unit of fuel consumed was selected for three common fuels:
natural gas, distillate oil, and bituminous coal.
Table 5-9
Comparison of CO2 Emission at GHG Thresholds to NEI Criteria Pollutant Emissions
1.000
mot l ie tons
CO:
10.000
metric tons
CO:
25.000 metric
tons CO:
100.000
metric tons
CO:
llicl
Criteri:i
I'olllllillll
Criteriii I'olliitiiiK Emissions Produced ;il CI MCI Threshold
Lex els (short tons)
Natural Gas
NOx
1
9
24
94
Distillate Oil
S02
3
34
85
342
Bituminous Coal
S02
9
86
214
856
*Notes: Criteria pollutant estimates are based on the following emission factors:
Natural gas - 0.1 lb NOx/mmBtu
Distillate oil - 0.5 lb S02/mmBtu
Bituminous Coal -1.6 lbs S02/mmBtu (1% coal sulfur by weight)
For distillate oil-fired sources the 25,000 metric ton GHG threshold approaches 100 short
tons of SO2. Coal-fired sources approach 100 short tons of SO2 at the 10,000 metric ton GHG
threshold. For natural gas-fired combustion sources the GHG thresholds are very low compared
to the NEI threshold, except for the 100,000 metric ton threshold which is comparable to the 100
short ton required NEI threshold for NOx-
5.9.2 Commercial Buildings
2 Some states provide data for smaller facilities, and there are lower emissions thresholds for volatile organic
compound emissions in ozone nonattainment areas that capture facilities with smaller combustion source emissions.
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In commercial facilities, GHG emissions are primarily from fuel combustion for climate
control and water heating. To evaluate threshold impacts on commercial buildings, we used
EIA's 2003 Commercial Building Energy Consumption Survey (CBECS) to estimate emissions.
CBECS is a national sample survey conducted by EI A that collects information on the stock of
U.S. commercial buildings, their energy-related building characteristics, and their energy
consumption and expenditures. 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. Thus, it
includes building types that might not traditionally be considered "commercial," such as schools,
correctional institutions, and buildings used for religious worship. The survey is currently
conducted every four years and the most recent survey available was completed for 2003.
EPA combined survey natural gas and oil usage for climate control and hot water with
CO2 emission factors to estimate building populations at different CO2 emissions thresholds.
Emissions from energy supplied to the building by district heating were not included in the
estimate.
Based on our estimates approximately 9,000 commercial building would emit CO2 above
the 1,000 metric ton annual threshold. Commercial building sectors affected include hospitals,
lodging, schools, laboratories, and office buildings. These buildings emitted about 22 million
metric tons of CO2 in 2003 from gas and oil combustion. Total 2003 commercial building CO2
emissions from gas and oil combustion are estimated at 128 million metric tons.3
The CBECS survey data show an insignificant number of commercial buildings reporting
with CO2 emissions above the 10,000 and 25,000 metric ton threshold, and no commercial
buildings over the 100,000 ton threshold. Of the 5,215 surveys submitted, only 15 had gas and
oil fuel usage that would produce emissions over 10,000 metric tons, and only one had emissions
over 25,000 metric tons.
5.9.3 Unspecified Industrial Stationary Combustion
EPA believes that the population of facilities over a 100,000 mtCC^e threshold is known
either through source category studies or reporting programs such as the NOx Budget or Title V.
On the other hand, estimates of the population of facilities at the 25,000 10,000 and 1,000
mtC02e options vary widely. Previous studies of thresholds, such as The Nicholas Institute and
Pew, relied on 2002 MECS and Census Bureau facility size information. The Nicholas Institute
study concluded that 8,162 stationary combustion manufacturing facilities would be affected by
a 10,000 mtC02e threshold. Yet the number of potential reporters is considerably larger. A 25
mmBtu/hr gas-fired boiler can exceed 10,000 mtC02e annual emissions if it runs above 80%
capacity. The above noted EPA U.S. boiler study (Table 5-5) found that there are 11,430 units in
3 The 128 million metric ton emission estimate is different from the commercial sector emissions reported in the
U.S. GHG Inventory. The inventory estimates are based on sales or delivery data provided by energy suppliers.
The energy supply data is divided into broad sector categories, but the suppliers' definition of commercial is likely to
differ from the CBECS definition. Suppliers tend to assign categories to their customers based on their rate class or
the amount of energy supplied, and not necessarily the actual activity in the building. For example, a small non-
energy-intensive assembly plant might be designated as a commercial customer while a large energy-intensive office
is considered industrial.
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the 50-100 mmBtu/hr range and an additional 34,000 units in the 10-50 mmBtu/hr category.
And this makes no allowance for other types of combustion equipment such as turbines.
Table 5-10 summarizes emissions-based threshold options for unspecified industrial
stationary consumption. The rounded total number of facilities (350,000) is from U.S. Census
data adjusted for the approximately 10,000 facilities in covered source categories described in
other technical support documents. EPA derived total emissions by subtracting source category
stationary combustion emissions from U.S. GHG Inventory 2006 number for industrial
combustion. Unspecified industrial combustion includes cogeneration, chemical processing and
a wide range of manufacturers and other activities. Due to the methodology employed, EPA
considers the results in Table 5-10 to be a coarse estimate of the relative effect of threshold
options.
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Table 5-10
Threshold
Level
mtC02e/yr
Total
National
Emissions
Million
mtC02e
Total Number
of Facilities
Emissions Covered
Facilities Covered
Million
mtC02e/yr
Percent
Number
Percent
1,000
410
350,000
250
61%
32,000
9.1%
10,000
410
350,000
230
56%
8,000
2.3%
25,000
410
350,000
220
54%
3,000
0.9%
100,000
410
350,000
170
41%
1,000
0.3%
EPA estimates total national emissions for unspecified industrial stationary combustion at
410 mtC02e per year, approximately 6 percent of total U.S. GHG emissions in 2006. At the
1,000 mtC02e threshold EPA estimates that approximately 32,000 facilities would be applicable
under General Stationary Fuel Combustion. The emissions from these facilities are
approximately 250 mtCC^e per year, which provides 61 percent national coverage of unspecified
industrial stationary combustion.
At the 10,000 mtC02e threshold the number of reporters is estimated at 8,000 facilities.
At this level, less than 3 percent of all commercial and industrial establishments would be
required to report. Note that although the number of reporters fell drastically from the first
option the national coverage declined only slightly from 61 to 56 percent. This trend indicates
that the distribution of emissions is weighted towards the larger facilities.
At the 25,000 mtCC^e option some 3,000 facilities would report, less than one percent of
the national total. Still, EPA estimates that national coverage of unspecified industrial stationary
combustion would be approximately 54 percent.
At the highest emissions threshold option (100,000 mtCC^e) approximately 1,000
facilities would report 170 mtCC^e emissions. A comparison to the first option is again
instructive. The additional 31,000 reporters at the 1,000 mtCC^e level would be reporting only
80 mtC02e additional emissions. Figure F-l below illustrates that as you move from lower to
higher emissions thresholds the number of reporters falls far faster than the emissions coverage.
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Figure F-l
Unspecified Industrial Stationary Combustion Emissions Coverage and Affected Facilities
at 4 Emissions-based Options
240 -
210 -
180 -
§150-
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'Notes -
1. The CARB dataset listed 7,085 facilities in 580 sectors with a total of 109 million mtC02e (combustion) emissions. This
summary covers 5,985 facilities in the 305 sectors that triggered at 1,000 metric tons of C02. Facilities include process emission
source categories such as cement and refineries.
2. Counts reflect only the effect of C02 emissions thresholds.
3. The results in Table 5-9 do not conform to the applicability provisions of the California rule. In particular, it makes no allowance
for the lower thresholds applied to electricity generators or other output capacity thresholds.
In a telephone meeting, CARB staff explained their rationale in selecting a 25,000 metric
ton threshold for stationary combustion. CARB sought to focus efforts on industrial sources.
Moving from the 100,000 to 25,000 level improves statewide emissions coverage from 88% to
93% and the number of reporters is still less than 300. Going the next step, from 25,000 to
10,000 increases emissions coverage to 96%, however, CARB found that hospitals, commercial
establishments and even elementary schools would be required to report at that level. Their
proposed threshold of 25,000 mtCC^e for stationary combustion emissions is intended to target
large industrial emitters. CARB staff reported that the proposal met with approval in public
meetings as striking a reasonable balance between emissions coverage and affected facilities.
Our analysis of the CARB data examined the number and makeup of SIC codes at the
four emission threshold options. A total of 508 SIC codes were represented in the dataset. We
found that at the 1,000 metric ton threshold level 305 industrial classifications would have been
affected including nursing homes and sports clubs. At the 10,000 threshold the number of
affected SIC codes falls to 119 but still includes elementary schools and dairy farms. At the
25,000 threshold level we found 62 classifications would be affected. They are primarily
industrial in nature and include oil and gas facilities, food processors and paper board mills. As
you move into higher emission thresholds the percent of emissions coverage in California
remains comparatively steady even as the number of reporters falls dramatically.
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6. Appendix A- Supporting Data for Threshold Analyses
Additional supporting data used to conduct the threshold analysis are included in
separate files in this docket entry (EPA-HQ-OAR-2008-0508-046). Please refer to the
following file names for additional information on specific source categories:
1. "Supporting Data for Threshold Analysis for Subpart E-W" contains
information for the following source categories:
¦ Ammonia Production
¦ Ethanol Production
¦ Ferroalloy Production
¦ Food Processing
¦ Glass Production
¦ Hydrogen Production
¦ Iron and Steel Production
¦ Lead Production
¦ Lime Production
¦ Nitric Acid Production
¦ Oil and Gas Production
2. "Supporting Data for Threshold Analysis for Subpart X-PP" contains
information for the following source categories:
¦ Petrochemical Production
¦ Petroleum Refineries
¦ Phosphoric Acid
¦ Silicon Carbide
¦ Soda Ash
¦ Titanium Dioxide
¦ Underground Mines
¦ Zinc
¦ Landfills
¦ Manure
¦ Coal Suppliers
¦ Petroleum Suppliers
¦ Natural Gas and Natural Gas Liquids Suppliers
¦ Industrial Gas Suppliers- Anesthetics
¦ CO2 Supply
3. "Additional Methodological Information Supporting Threshold Analysis for
Specific Source Categories" contains information for the following source
categories:
¦ Aluminum Production
¦ Adipic Acid Production
¦ Cement Production
¦ Fluorinated GHG Production
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¦ Glass Manufacturing
¦ Lime Production
¦ Magnesium Production
¦ Oil and Gas- Gas Processing
¦ Oil and Gas- LNG Storage
¦ Pulp and Paper
¦ Industrial Gas Suppliers
4. Separate workbooks contain background thresholds data for the following source
categories:
¦ Aluminum Production
¦ Electronics
¦ SF6 from Electric Power Systems
¦ HCFC-22 Production
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7. References
California Air Resources Board (CARB), Conference call with EPA and CARB staff, (March 26,
2008).
Environmental Energy and Analysis, Inc., Characterization of the U.S. Industrial Commercial
Boiler Population, submitted to Oak Ridge National Laboratory (May 2005).
http ://www. eea-inc. com/ showbriefspubs.html
European Union, Emission Trading Scheme (ETS) - Guidelines for Monitoring and Reporting
Greenhouse Gas Emissions (Pursuant to Directive 2003/87/EC of the European Parliament and
of the Council, July 18, 2007). http://ec. europa. eu/environment/climat/emission/mrg en.htm
Intergovernmental Panel on Climate Change, 2006 IPCC Guidelines for National Greenhouse
Gas Inventories, 2006. http://www.ipcc-nggip.iges.or.ip/public/2006gl/index.html
U.S. Census Bureau, 2002 Economic Census, Industry Series Report, Manufacturing, 2005.
http://www.census.gov/econ/census02/
U.S. Energy Information Administration (EIA), Monthly Energy Review, Appendix - Estimating
Power Sector Fuel Use, April 2003. http://www.eia.doe, gov/emeu/mer/pdf/pages/sec 12_d.pdf
U.S. Energy Information Administration (EIA), 2002 Manufacturing Energy Consumption
Survey, January 2007. http://www.eia.doe.gov/emeu/mecs/mecs2002/data02/shelltables.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_pudata20Q3.html
U.S. Energy Information Administration (EIA), Power Plant Survey Forms 906 and 920
Database, December 11, 2007. http://www.eia.doe.gov/cneaf/electricitv/page/eia906_920.html
U.S. Environmental Protection Agency (EPA), Inventory of U.S. Greenhouse Gas Emissions and
Sinks: 1990 - 2006, April 2008, US EPA 430-R-08-005.
http://www.epa.gov/climatechange/emissions/usinventorvreport.html
U.S. Environmental Protection Agency (EPA), Clean Air Markets Division, Data and Maps
Database, June 4, 2008. http://camddataandmaps.epa.gov/gdm/
World Resources Institute/World Business Council for Sustainable Development
(WRI/WBCSD), Measuring to Manage, A Guide to Designing GHG Accounting and Reporting
Programs, Copyright World Resources Institute, November 2007. http://www.ghgprotocol.org/
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